Submissões recentes

  • IPEN-DOC 24852

    SOUSA, THAINA S.; JACOVONE, RAYNARA M.S. ; SOARES, JAQUELINE J.S. ; RODRIGUES, DEBORA F.; SILVA, FLAVIA R. de O. ; GARCIA, RAFAEL H.L. ; ZAIM, MARCIO H.; SAKATA, SOLANGE K. . Antimicrobial activity of Graphene Oxide/Silver nanocomposite obtained by Electron Beam. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: Graphene oxide is a carbon-based nano material that has a high specific surface area, high chemical stability, excellent electrical and thermal conductivities, high mechanical resistance, the oxygen groups facilitate dispersion in polar solvents and its functionalization. In the literature, is described several methods of metal incorporation on graphene oxide surface using toxic reagents or with long periods of reaction. The objective of this work is to develop an innovative and sustainable method of incorporating silver into graphene oxide that does not involve toxic reagents or generated residues. in a short reaction time at room temperature beyond the use of the as an alternative process to the chemical processes traditional.A silver solution in the complex form was added to a dispersed graphene oxide in water/isopropanol solution. The mixture wassubmitted to a dose of radiation ranged from 150 to 400 KGy using a electron beam acelerator. The nanocomposite GO/Ag characterization was performed by thermogravimetry analysis (TGA), X-ray diffraction (XDR), scanning transmission electron microscope coupled to the energy dispersive X-ray spectrometry (TEM/EDS). The antimicrobial activity of GO/Ag was observed by Escherichia coli, a Gram negative bacterium and Bacillus subtilis a Gram positive bacterium in solid culture medium. The minimum inhibitory concentration of GO/Ag was 50 mg/L. .It is noteworthy that the incorporation of silver occurred at the same time the reduction of graphene oxide without the generation of toxic chemical residues.


  • IPEN-DOC 24851

    SOBRINHO, LUIZA F. ; GOTO, PAULA T. ; GARCIA, RAFAEL H.L. ; FRANCISCO, DANIEL; ANGNES, LUCIO; SAKATA, SOLANGE K. . The study of chemical and physical properties of Polyaniline-Graphene Oxide and Palladium Polyaniline-Graphene Oxide composites. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: A Polyaniline (PANI)-Graphene Oxide (GO) composite was studied for the electrical activities. The GO was obtained by modified Hummers method. For the palladium nanoparticles (Pd-NPs) incorporation, it was established an environmentally friendly approach based on electron beam reduction. The chemical characterization was performed by Fourier Transform Infrared (FTIR) spectroscopy, Thermogravimetry (TG), X-ray Diffraction (XRD) and for the electrical properties Cyclic Voltammetry (CV) in alkaline medium and conductivity measurements. The FTIR spectroscopy and TG were used to obtain the composition of the synthesized materials, while XRD pattern indicated polymerization quality and the crystallization degree of the samples. The CV and conductivity measurements indicated the electrical activity of the composite. The results showed the GO amount was directly proportional to the resistivity of PANI, and when the Pd (Pd-Pani-GO) was present, the CV showed a larger current than the Pd-GO. The high electrochemical performance of the Pani-GO electrode could be due the increasing active sites for the deposition of polyaniline provided by large surface areas of graphene oxide sheets and the synergistic effect between polyaniline and GO. These results demonstrated the importance and great potential of graphene oxide in the development of high-performance conductivity system based on polyaniline.


  • IPEN-DOC 24850

    SOARES, JAQUELINE J.S. ; JACOVONE, RAYNARA M.S. ; MATHOR, MONICA B. ; ZAIM, MARCIO H.; MAIZATO, MARINA J.S.; CESTARI, IDAGENE A.; JATENE, FABIO B.; SAKATA, SOLANGE K. . The effect of GO-PEG-NH2 on the mechanical resistance of bovine pericardium used in cardiovascular device. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: Valvular heart disease (VHD) is a clinical condition where one of the four-heart valves is damage or has a defect. It was estimated that approximately 300,000 to 400,000 heart valve replacement surgeries were performed in 2014. There are two types of prostheses, the bioprothesis and the mechanical prosthesis. Even though the first one presents a smaller rejection, its durability is reduced due to calcification followed by deterioration. The objective of this work was to increase the durability of prostheses made from bovine pericardium (BP) by incorporating GO functionalized with amino-PEG (GO-PEG-NH2). Briefly, GO functionalized was firstly sterilized with gamma radiation and then incorporated to BP in two different ways: chemical and physical. Mechanical characterization assays of BP treated with GO-PEG-NH2 and untreated (control) were performed in an INSTRON model 3365 universal test equipment using the BioPlus accessory, which allows the assays to be carried out immersed in a physiological solution of 0,9% NaCl at 36 °C, simulating the environment of material’s application. The static deformation in the uniaxial direction of the test specimens was verified using the ASTM D638-10 standard test method for tensile properties of plastics, 2010 from the American Society for Testing and Materials (ASTM Standards). The results indicated that GO-PEG-NH2 improved the mechanical strength of the biomaterial, increasing the resistance to permanent plastic deformation, maximum supported load, flow limit, maximum traction tension, rupture tenacity and rupture traction tension no matter of GO-PEG-NH2 incorporation methods and it is possible to improve the performance of bioprothesis by coating them with GO-PEG-NH2 and consequently increasing their durability.


  • IPEN-DOC 24849

    SOARES, JAQUELINE J.S. ; COSTA, CARLOS A.R.; JACOVONE, RAYNARA M.S. ; ZAIM, MARCIO H.; SAKATA, SOLANGE K. . Characterization by atomic force microscope (AFM) of graphene oxide and graphene oxide-PEG-NH2 incorporated in bovine pericardium. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: Atomic force microscopy (AFM) is a technique that allows images from the surface topography with high spatial resolution at Nano metric scales. AFM has being used in several fields in science such as Biology, Medicine, Chemistry and Pharmaceuticals. In this study, the tecnhique was used to characterize graphene oxide and graphene oxide functionalized with amino-PEG (GO-PEG-NH2) in the bovine pericardium (BP) surface. The treatment of BP with GO and (GO-PEG-NH2) improved the mechanical properties of the biomaterial that will be used in the manufacture of cardiovascular device that is used to replace heart valves. For the BP coating, two different pathways were tested: 1) chemical pathway using solution containing 1-Ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and GO; and 2) in physical adsorption the incorporation were performed by ultrassom. The same procedure was performed to incorporate GO-PEG-NH2. The images of the BP with its modified surface were obtained by AFM and proof the efficiency in the two incorporation processes. The study also demonstrated the applicability of AFM to characterize incorporated nanomaterial in the biological samples.


  • IPEN-DOC 24848

    SEIXAS, MARCUS V. de S.; RANGARI, VIJAYA K.; MOURA, ESPERIDIANA A.B. ; WIEBECK, HELIO. Preparation and characterization of nanocellulose from sugarcane bagasse. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: Nanocellulose is steadily gaining attention since this material is a renewable alternative to reinforce polymers. Research and development of materials obtained from renewable natural sources have been the focus of attention in various engineering applications. The residues from different kinds of lignocellulosic materials has great potential for production of biocomposites, which are applied in optoelectronic devices, packaging, and building. The main object of this work was study of nanocellulose preparation from sugarcane bagasse and its characterization. The sugarcane bagasse was submitted to chemical treatment for separating of the cellulose from the lignocellulosic material, bleaching with hydrogen peroxide followed by sonication treatment for obtaining nanocellulose. Sonication treatment solution was prepared with a cellulosic material in water/DMF(dimethylformamide)/ethanol. Sonication treatment was done in a DES500 ultrasonic cell tip/horn sonicator with a 20 kHz ultrasonic frequency. The nanocellulose samples were characterized by FTIR, XRD, FE-SEM and TEM analysis. According to the results, the methodology used in this work presented a great potential to the obtaining of nanocellulose for applications in the development of new nanocomposite materials.


  • IPEN-DOC 24847

    SANTOS, JONNATAN J. ; LEAL, JESSICA ; DIAS, LUIS A.P. ; TOMA, SERGIO H.; CORIO, PAOLA; ARAKI, KOITI; GENEZINI, FREDERICO A. ; KATTI, KATTESH V.; LUGAO, ADEMAR B. . Synthesis of high stable gold (198) nanoparticles for radiotherapy. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: Cancer has become a problem in the last years, is expect be diagnosed more than 500 000 new cases in 2017, only in Brazil, according to Brazilian Cancer Nacional Institute. Among women breast cancer is the most common and among men the most representative is prostate cancer, and although treatments for both cancers have been already developed, new methods more efficient and that causes less damage to the patient are always being searched. Gold nanoparticles (AuNps) have many different applications on chemistry, biology, medicine, etc; their low reactivity and toxicity and high stability become it very interesting for bioapplications, such as drugs delivery and biosensing. In this work, we had developed a new method to prepare 198AuNps, from a leaf of gold bombed by neutrons, adapting Turkevich method, these nanoparticles were modified with bovine serum albumin (BSA) and characterized by multiple techniques, after 30 days (eleven half-life decays). This methodology was capable of generate AuNps with almost 14 nm and Zeta potential higher than -37 mV, very stable. BSA can be used for different applications, like a simple stabilizer or to increase cellular uptaking, but in our case its chromophore groups were utilized to follow damages caused by radiation, as a sensor for radiation damage, a dosimeter. Bellow are presented TEM image, Zeta potential measures and fluorescence spectroscopy of the 198AuNps-BSA samples.


  • IPEN-DOC 24846

    SANTOS, MONIQUE C.L. ; OLIVEIRA NETO, ALMIR . Oxidation of methanol on PtRuIn/C in alkaline medium: effect of metals on the electrocatalytic activity. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: In this work the different electrocatalytic systems PtRu(50:50)/C, PtIn(50:50)/C, PtRuIn(50:10:40)/C and PtRuIn(50:40:10)/C were synthesized by the sodium borohydride reduction method, in order to be used as an anode in the alkaline fuel cell in the presence of methanol. The obtained materials were characterized by EDX, DRX and MET techniques. The reduction method applied in the synthesis was effective, since the particles showed good dispersion in the carbon support Vulcan XC72, according to the EDX and MET analyzes. The results obtained by XRD showed in all the diffractograms presented the FCC structure of platinum and a relative displacement of the equivalent peak to the plane (220) for values greater than and less than 2Ɵ. The mean crystallite size and the calculated net parameters indicated the insertion of Indium and Ruthenium atoms to the Platinum structure, assuming the formation of alloys. The electrochemical oxidation of methanol was studied by cyclic voltammetry, chronoamperometry and polarization curves. The PtRu(50:50)/C electrocatalyst in alkaline media showed the higher electrocatalytic activity fot the methanol electro-oxidation at room temperature compared to the others electrocatalysts prepared. The experiments in alkaline single direct methanol fuel cell (DMFC) also showed that PtRuIn(50:10:40)/C electrocatalyst exhibited higher performance for methanol oxidation at 80ºC, in comparison with the others electrocatalysts synthesized. These results indicated that the addition of Ru and In promote the methanol electrochemical oxidation, which could be attributed to the bifunctional mechanism (the presence of Ru and In oxides species) associated to the electronic effect (Pt-Ru-In alloys).


  • IPEN-DOC 24845

    SANTANA, JULYANA G. ; SEIXAS, M.V. de S.; ARANTES, MARIANA ; GUVEN, OLGUN; MOURA, ESPERIDIANA A.B. . Effects on Clay addition on properties of LDPE flexible films. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: Studies have indicated that the addition of nanoparticles in flexible films improves performance flexible packaging, leading to better mechanical, thermal and barrier properties. Clay is an abundant mineral, inexpensive, easy to process, and provide considerable enhancements on the properties of polymers. Titanium dioxide (TiO 2 ) is widely used for its efficiency in scattering visible light, and imparting whiteness, brightness, and high opacity when incorporated into a plastic formulation. Low density polyethylene (LDPE) is generally used as a packaging material due to its good resistance, easy processing, low cost and high hardness. The objective of this study was to evaluate the effects of clay and TiO 2 nanoparticles addition on the properties of LDPE flexible films. LDPE with 1 wt % of TiO 2 addition and 1-3 wt. % of green Brazilian Clay, from Cubati, Pb, Brazil were prepared by melt extrusion process, using a twin-screw extruder Haake Rheomex P332 with 16 mm and L/D = 25, from Thermo Scientific. Then the LDPE/Clay nanocomposite was transformed into thin films using an extrusion blown film, single screw machine with 25 mm diameter and specimen test samples were obtained. The specimen samples were characterized by mechanical tests, UV-VIS, DSC, TG and FE-SEM analysis.


  • IPEN-DOC 24844

    SAKATA, S.K. ; SOBRINHO, L.F.; JACOVONE, R.M.S.; SOARES, J.J.S.; TOMINAGA, F.K.; ANGNES, L.; GARCIA, R.H.L. . Sustainable synthesis of transition metals/graphene oxide nanocomposites by electron beam irradiation. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: Graphene is nanomaterial with unique physical and chemical properties that makes it a precursor for the synthesis of new materials, such as conductive nanocomposites. Graphene can be obtained by the reduction of graphene oxide, but when it is incomplete, reduced graphene oxide (rGO) is produced with both graphene and graphene oxide properties: it is electrical and thermal conductor, it can be exfoliated in several polar solvents and moreover, the oxygen groups can later be functionalized, affording nanocomposites for electrochemical applications and also in biomaterials. A method of increasing the electrical conductivity of graphene-based compounds is by the incorporation of metallic nanoparticles. When these nanomaterials are joined together the surface area increases for the passage of electric current and the electrical conductivity. The chemical reduction method for the incorporation of metallic nanoparticle on GO involves toxic reagents or it is a time-consuming and it also requires high costs for the removal of excess reagents and by-products. The general synthesis of transition Metal/graphene-based nanocomposites by the electron beam in a sustainable process will be presented. The experiments were performed in a 1.5 MeV electron accelerator at room temperature and no hazardous wastes were generated. The nanocomposites were characterized by FT-IR, DRX and TEM/EDS as metallic nanoparticle at the average size of 5-20 nm incorporated into reduced graphene oxide layers. The electrochemical behavior of these nanocomposites was evaluated by cyclic voltammetry.


  • IPEN-DOC 24843

    RODRIGUES, THENNER S. ; MOURA, ARTHUR B. ; SILVA, FELIPE A. e ; CANDIDO, EDUARDO G. ; BERGAMASCHI, VANDERLEI S. ; FERREIRA, JOAO C. ; LINARDI, MARCELO ; FONSECA, FABIO C. . Hardwired for success: Ni supported CeO2-Sm2O3 nanowires as a super stable catalyst for ethanol steam reforming. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: CeO2-based nanomaterials have been extensively employed in catalysis and industry, showing excellent performances towards a variety of applications. In the past few decades, great developments have been reported associating the properties of nanostructured CeO2 with its catalytic performances. Thus, an intense research in this field have been performed in order to increasingly improve the performances of these nanomaterials such as the precise control over their structures, morphologies, compositions, among others. We propose herein, the synthesis of a novel well-defined Sm2O3-doped CeO2 nanowires decorated with nickel nanoparticles as a novel catalyst with outstanding performance towards ethanol steam reforming (ESR). In order to address these challenges, we were inspired by a well-established hydrothermal method for the synthesis of CeO2 nanowires. Herein, through simple modifications in the original protocol allowed us the obtaining in high yield (97%) extremely well-defined CeO2-Sm2O3 nanowires exhibiting uniform distributions in lengths and diameters. XRD results (Figure 1A) suggested the introduction of Sm species into the CeO2 crystal lattices, in which the quantitative Sm3+(aq) conversion achieved 10 mol%, as corroborated by ICP-OES analysis. The resulting CeO2-Sm2O3 nanowires were then employed as support for the Ni incorporation (1 wt%) by a wet impregnation approach, and the obtained catalyst (Figure 1B) was evaluated towards the ESR displaying an exceptional stability even after 100 hours of process at 550 °C. More specifically, 100 % of ethanol conversion was observed with the formation of only H2 and CO2 (ESR products) and CO and CH4 as byproducts (both in low concentrations), indicating a good selectivity for ESR compared to the most recent literature. The characterization data for the Ni/CeO2-Sm2O3 nanowires after catalytic experiment (Figure 1C) indicated that, even after 100 hours at 550 °C, no loss of shape was observed as well as no carbon structures formation justifying the exceptional observed stability.


  • IPEN-DOC 24842

    REIS, PEDRO R.S.; SANTANA, JULYANA G. ; OLIVEIRA, RENE R. ; RANGARI, VIJAYA K.; MOURA, ESPERIDIANA A.B. . Biodegradable polymer blends reinforced with bio-hydroxyapatite nanoparticle - preparation and characterization. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: Nowadays significant advances have been made in the development of biodegradable polymeric materials for biomedical applications. The purpose of this study was to preparation and characterization of biodegradable polymer blend reinforced with bio-hydroxyapatite nanoparticle from eggshell by sonochemical method. Biodegradable polymer blends based on PLA (Poly(lactic acid)) and the PBAT (butylene adipate-co-terepthalate)) reinforced with 1-5 wt. % of bio-hydroxyapatite were prepared by melt extrusion, using a twin screw extruder and injection molding machine to obtain specimen test. The effects of the bio-hydroxyapatite addition on properties of PLA/PBAT biodegradable blend were investigated by tensile tests, XRD, DSC, TG and SEM-FEG analysis and the correlation between the results was discussed.


  • IPEN-DOC 24841

    PINHO, PRISCILA G.M. ; OLIVEIRA, FABIO B.V. ; ANDRADE, DELVONEI A. ; ROCHA, MARCELO S. . Experimental study of radiation influence on thermophysical properties of Al2O3 and ZrO2 nanofluids. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: Nanofluids are a promising technology for application in nuclear reactor systems for high heat flux transport. As demonstrated by the recent researches, nanofluids have very interesting physical properties with respect to its ability to remove and transport of heat. There is, currently, research groups in the world conducting investigations on the influence of ionizing radiation on nanofluids and the possibility of its use as working fluid or cooling of the core of nuclear reactors core in cases of accidents. Among the countless applications presently proposed for the nanofluids, the applications in energy have special attention by academic and industrial interest. Studies demonstrate that nanofluids based on metal oxide nanoparticles have physical properties that characterize them as promising working fluids, mainly, in industrial systems in which high heat flux want to be removed. The nuclear reactors for power production are examples of industry where such an application has been proposed. However, there are no concrete results about the ionizing radiation effects on nanofluids properties. This work aims to present the initial results of the current study carried out with the objective to check the effects caused by that ionizing radiation on nanofluids based on Al2O3 and ZrO2 nanoparticles. Results from thermophysical analyses demonstrate that particular behavior on thermal conductivity, and density of such nanofluids can be observed as a function of temperature under no ionizing radiation effect. New investigations will analyze the application potentiality of some nanofluids in nuclear systems for heat transfer enhancement under ionizing radiation influence.


  • IPEN-DOC 24840

    PERINI, ALINE A. ; FREITAS, ANDERSON Z. . Innovation trajectories: an IPEN´s nanotechnology competence roadmapping to match´s market mechanisms. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: The main objective of this work is to present general framework of the impact of technological innovation in the IPEN´s nanotechnology competence. The innovation are vital to improvement offer through chains front-to-end in health, environment, food and agriculture, energy, chemistry, education, entertainment and arts: treat supranational levels, offers accessible global technology. The pool innovation perspective in IPEN´s nanotechnology competence is a natural consequence of investments in Research and Development (R&D), between and among Universities and Public Research Institutions and multiple benefits arising from results, towards Awards in Science and policy disclosure. Geographically IPEN is held at São Paulo, Capital, one of the 10 biggest cities of the globe with high density on population and market demand. The innovation impact measures depend of (1) quality of diversified technology knowledge and (2) quality of diversified country industry knowledge that can be more specified. From this big view picture, the IPEN Technology Transference Office took account both dimensional innovation impact measures and listed detail in four (4) dimensional approach performance indicators over 5 years casting potential benefits outcomes in areas: a) human resource, b) services and products, c) research, teach and educational, d) intellectuals property, patents, projects, creativity and inventiveness. Regarding on Key Innovation Indicators and Policy of Impact Measures, the methodology applied to the present study consists oh the three main stages. First stage is a review with bibliometric analysis of market dynamics and technological management approach. The second stage was characterized by the data collection on management system from IPEN in labeled activities on nanotechnology. The third stage was marked to the understanding of the structure and the dynamics of nanotechnology markets, especially their sometimes acute response in innovation. The case study in IPEN´s in nanotechnology market built a preliminary assessment from a suitable a roadmapping system. Roodmapping is one of the most widely used tools as predictive exercise, supporting systematic planning and standardized strategy development. Many countries have developed standardization of roadmaps in various areas reported in intelligent systems, identifying significant opportunities and challenges associated with standardization in complex areas. IPEN´s nanotechnology competence in numbers is an inspirational approach engine and large influence in cultural and Institutional policymaking in Science, Technology and Innovation (S&T&I). The unique strengthen link can be matched from the S&T&I policy in term "technology transfer” in capacity building from push or/and pull innovation models. The central competence framework aimed at advancing knowledge necessary that would eventually lead to innovation trajectories and with strong security cultural insertion gauge to country succeed in international competition through innovation and growth, high-quality products and services, and research and education. Strategic differentiation could lead disruption in technology and development of new markets. The solutions by market-driven provide improvement at total quality managing front-to-end of technology transfer.


  • IPEN-DOC 24839

    OSHIRO, MAURICIO T. ; SAKATA, SOLANGE K. ; POTIENS JUNIOR, ADEMAR J. . Adsorption isotherms for the removal of Am-241 in radioactive liquid wastes using magnetite nanoparticles. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: Americium-241 (Am-241) is a radionuclide with half-life of 432 years, emitting alpha particles and low gamma energy and it is also considered radiotoxic. Am-241 is produced, in a low level, from nuclear fuel and laboratory wastes. Magnetite nanoparticles (Fe3O4) are iron oxides that possess highly magnetic properties, and its application for removal of water contaminants refers due to its high surface area which allows the adsorption capability and the facility to be prepared and removed from the aqueous medium. In This study, magnetite was synthesized by coprecipitation method largely described. Batch experiments were accomplished at room temperature, at pH 6 and the contacts varying from 2.5, 5, 10, 20, 30, 40, 50, 60 minutes and at 30 minutes for the isotherms experiments. The solid containing magnetite and Am-241 were removed with a magnet and the solution analyzed in a gamma-ray spectrometer (Canberra Model GX2518) which could be quantified. Results show that magnetite possess a capability of removal up to 80% of Am-241 at room temperature, indicating that magnetite nanoparticles are a good sorbent for the removal of radionuclides. Langmuir and Freundlich Isotherms models were investigated and the parameters obtained. Langmuir’s isotherm showed constants of KL (75.7575 L/mg), Q (0.1617 mg/g) and R2 (0.9892) and Freundlich’s isotherm exhibited values of KF (2.6416 [(mg/g).(L/mg)1/n]), 1/n (0.7853 mg/g) and R2 (0.8395), which indicates that the Am- 241 removal from magnetite fits more suitable the Langmuir isotherm model. The thermodynamics parameters, such as the enthalpy and entropy of adsorption, the activation energy, as well as, the kinetics studies are under development.


  • IPEN-DOC 24838

    OLIVEIRA, FERNANDO M. ; POTIENS JUNIOR, ADEMAR J. ; FEJFAR, JOSE L.; RODRIGUES, DEBORA F.; DI VITTA, PATRICIA B.; SAKATA, SOLANGE K. . Immobilization of graphene oxide in a poly(divinylbenzene) matrix for the treatment of liquid radioactive waste containing 137Cs. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: Cesium is one of the fission products of major radiological concern, it is often found in nuclear radioactive waste generated at nuclear power plants. Several methods are used to treat radioactive aqueous waste, especially adsorption, which is a technique that combines cost and efficiency and is widely used in preconcentration of radionuclides. Graphene Oxide (GO) has attracted great attention due to its functionalized surface, which includes hydroxyl, epoxy, carbonyl and carboxyl groups, with great capacity of complexation of metal ions and it can be used as adsorbent to remove cesium from radioactive liquid wastes.This work, GO was immobilized in poly(divinylbenzene) to increase the specific mass and grain size of the adsorbent, that can be easily remove from solution by vaccum filtration or being used in a fixed bed column. The incorporation of the GO on the polymer surface was confirmed by electron scanning electron microscopy (SEM) Figure 1.


  • IPEN-DOC 24837

    OLIVEIRA, MARIA J.A. ; SANTOS, JONNATAN J. ; TOMA, SERGIO H.; ALCANTARA, MARA T.S. ; VASQUEZ, PABLO A.V.; ARAKI, KOITI; LUGAO, ADEMAR B. . Hydrogels with silver nanoparticles for wound treatment. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: In recent years, the study and preparation of nanoparticles have attracted considerable interest for both fundamental and applied research. In biomedical area, silver nanoparticles have been a vast field of study, although antimicrobial properties have originated from their medical application since 19th century. Since silver has had several uses and its enormous potential for the treatment of injuries. Silver-containing topcoats are an excellent option for topical microbial combat on wounds that present infection, as well as being an essential tool for controlling bacterial load. Among these coatings are the hydrogel dressings with silver nanoparticles that have broad spectrum of antimicrobial action. In vitro studies have demonstrated bactericidal activity in strains of antibiotic resistant microorganisms. The objective of this work is characterize hydrogels with silver nanoparticles, prepared using polyvinylpyrrolidone (PVP), carboxymethylcellulose (CMC), used to treat wounds. A gamma radiation source cobalt-60 was used to crosslink the hydrogels, sterilize and form the silver nanoparticles simultaneously. Irradiation is recognized as a very viable tool because there is no need to add possibly harmful primers or crosslink that are difficult to remove. The results showed uniform distribution of the nanoparticles on the surface of the hydrogels, making it feasible for topical application.


  • IPEN-DOC 24836

    MOURA, TIAGO S.; GOTO, PAULA T. ; GARCIA, RAFAEL H.L. ; SALVADOR, PABLO A.V. ; SANTOS, PAULO S. ; SOARES, JAQUELINE J.S. ; NODA, LUCIA; SAKATA, SOLANGE K. . Gamma radiation assisted reduction of graphene oxide in unoxidized environment. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: Graphene is a honeycomb like structure of carbon atoms of sp2 hybridization, with remarkable physical and chemical properties. Perhaps, the most desirable properties of a such material is the quasi-ballistic electronic transport and its excellent thermal conductivity that make graphene an excellent alternative to build electronic devices related to silicon, for instance. However, the lack of organic functions and the strong bonds between carbons in graphene nano-sheets make them unable to undergo functionalization reactions, that is important for many applications such as gas and biochemical sensors or nanoparticles decoration. So, in order to allow the functionalization of graphene nano-sheets and make possible a variety of new applications it was developed a nanomaterial based on the oxidation and exfoliation of graphite: the graphene oxide. This new material has epoxide and hydroxyl groups in the basal planes, with carboxyl groups in the borders, improving the hydrophilic properties and potential for chemical functionalization. Graphene oxide also serves as a starting material to graphene production by reduction routes. Partial reduction of graphene oxide leads to reduced graphene, a nanomaterial that combines both proprieties of graphene and graphene oxide: an excellent electrical and thermal conductivity, high superficial area and remaining oxygen groups that allow its functionalization. In the literature is described different ways to produce reduced oxide graphene from graphene oxide, such as chemical reduction using hydrazine hydrate or NaBH4, thermal reduction using high temperatures and plasma hydrogenation. Here in it is described a sustainable process to reduce graphene oxide in sodium bisulfite solution using gamma radiation. Exfoliated Graphene oxide (1-100mg/L) with NaHSO3 under inert medium was submitted to gamma radiation. The radiation dose ranged from 50 to 500 kGy and the product was centrifuged and analyzed by X-ray diffraction (XRD), Raman and infra-red (FT-IR) spectroscopies. It was observed that depending on the dose total or partial reduction was achieved. This methodology does not produce any toxic residue.


  • IPEN-DOC 24835

    LUGAO, ADEMAR B. ; FAZOLIN, GABRIELA N. ; VARCA, GUSTAVO H.C. ; SANTOS, JORGE G.; BARROS, JANAINA ; FUCASE, TAMARA ; SANTOS, JONNATAN J. ; LEAL, JESSICA ; GRASSELLI, MARIANO; KATTI, KATTESH V.. Radiation-induced "one pot" synthesis for cell therapies. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: The dream of Marie Curie lab’s expressed by Regaud and Lacassagne in 1927 was to administer radiations with penetration range of molecular dimensions to the organism and selectively fixed in the protoplasm of cells one seeks to destroy. Gold nanoparticles can be employed as a radiation sensitizer by utilizing mainly Auger effect and photoelectrons. Auger electrons are released in large numbers with low kinetic energy therefore these electrons damage cells over a very short range: less than the size of a single cell, on the order of nanometers. Gold-198 is a beta and gamma emitter can be employed for therapy as well as diagnostic. The radioactive properties of gold include: Au (βmax=0.96 MeV; t1/2 = 2.7 days) and Au (βmax =0.46 MeV; t1/2 = 3.14 days), making it a strong candidate for theranostics. However, Gold or Gold-198 need to internalize selectively in tumor cells. Conjugation with proteins and peptides can make them very selective. While radioactive nanoparticles can offer a much higher dose payload than ions for therapy and diagnostic, in addition to the huge surface to bind targeting species presented by the nanoparticles, functionalization with proteins may potentially increases the particle uptake by tumors or tissues. Albumin and Papain features a set of characteristics that assure applications as natural drug carriers with particular attractive properties in oncology. Albumin may be easily crosslinked and engineered towards loading of large number of hydrophobic molecules as well as hydrophilic ones. They can be bound in a reversible way and the delivery controlled by endogenous mechanism. Alternatively to conventional systems, albumin can be crosslinked by radiation in such way that dialdehydes or toxic chemicals are totally avoided . Conjugation of such materials with sugars, peptides, antibodies, proteins among others is routinely used nowadays for targeting. The main purpose of this work was the development of one pot in situ synthesis of radioactive gold 198 nanoparticle encapsulated by albumin for application in cancer Theranostics. While crosslinked albumin may provide a nontoxic coating on AuNPs with a controllable hydrodynamic diameter, conventional AuNP can be activated by nuclear reactor to produce AuNP. The gamma or beta radiation originated from the gold nanoparticle was used to crosslink the Albumin layer. The use of a radioactive particle able to emit radiation for crosslinking of the Albumin layer and simultaneous theranostic application was tried for the first time. The elegant procedure and simplicity of the production process combined with the properties of Au and the safety of AuNP/BSA make this new particle an exciting advancement in cancer therapy and diagnosis. Gold conjugated protein nanoparticles and protein nanoparticles itself were also produced in an radiation induced one pot process. Crosslinking and protein damage werea cessed by different techniques.


  • IPEN-DOC 24834

    LODIS, ALINE M. ; SEIXAS, M.V. de S.; VALENZUELA-DIAZ, FRANCISCO; GUVEN, OLGUN; MOURA, ESPERIDIANA A.B. . Structure and thermal/mechanical properties of poly (ϵ‐caprolactone)‐clay blend: synthesis and characterization of eva/clay flexible films treated by electron beam radiation. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: In the area of nanotechnology, polymer matrix based on nanocomposites have generated a significant amount of attention in the recent literature. The achieved results were at least initially viewed as unexpected (‘‘nano-effect’’) offering improved properties over that expected from thermal and mechanics predictions. This work presents the synthesis and characterization of EVA/Clay flexible films treated by electron beam radiation. EVA with 0.5 -3 wt.% of green Brazilian Clay addition were prepared by melt extrusion process, using a twin-screw extruder Haake Rheomex P332 with 16 mm and L/D = 25, from Thermo Scientific. Then, EVA/Clay nanocomposite was transformed into flexible films using a single-screw extruder with 25 mm diameter equipped with a flat die (laboratory line) and specimen test samples were obtained. Part of flexible film samples was submitted at electron beam radiation dose range 25-100 kGy using a 1.5 MeV electron beam accelerator, at room temperature in presence of air. The irradiated and non-irradiated samples were submitted to mechanical tests, XRD, UV-VIS, DSC, TG and FE-SEM analysis. The results showed significant changes in mechanical and thermal properties of EVA/CLAY flexible film due to clay addition and electron-beam irradiation. These results showed that it is possible to get interesting property in EVA flexible films by clay addition and electron-beam radiation treatment


  • IPEN-DOC 24833

    KOMATSU, LUIZ G.H. ; OLIANI, WASHINGTON L. ; RANGARI, VIJAYA K.; PARRA, DUCLERC F. ; LUGAO, ADEMAR B. . Synthesis of ZnO for biocide activity on SEBS/PP applications. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: Antimicrobial activity represents a challenge for scientific community. Polymer processing conditions impose temperature limitation for stability of biocide nanoparticles. In the present work, we evaluate ZnO synthesized in laboratory, utilizing Zn(NO3)26H2O as precursor. The main proposal is to improve the incorporation of this nanoparticle on SEBS/PP resulting on biocide material films. Before application on SEBS/PP, the nanoparticles was tested by reduction of forming colony units (CFU)(%), Dynamical Light Scattering (DLS) and Zeta potential. On CFU tests, all samples showed biocide properties. The samples with concentration of 1% showed the higher biocide effect on E.coli bacteria, in comparison of lower concentrations. The obtained material biocide was processed on SEBS/PP for obtaining of polymeric films with biocide activity and the new material was characterized by: forming colony units (CFU)(%), Differential Scanning Calorimetry (DSC), and Fourier Transformed Infrared (FTIR).


  • IPEN-DOC 24832

    JARA, FERNANDO G.B. ; CRUZ, PEDRO V.D.; GALDINO, GABRIEL S.; CASINI, JULIO C.S.; SAKATA, SOLANGE K. ; FARIA JUNIOR, RUBENS N. . Thermal reduction of graphene oxide nanocomposite using a low temperature HDDR process for supercapacitors. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: Recently, it has shown that the hydrogenation disproportionation desorption and recombination (HDDR) process can be an efficient method for the production of reduced graphene oxide for supercapacitors electrodes. The HDDR reduced graphene oxide was processed using a standard temperature (850 o C) for other materials applications. Some improvement in the specific capacitance and in the equivalent serial resistance has been obtained with this particular hydrogen thermal reduction process. The HDDR process has been considered a promising alternative method of reducing graphene oxide with efficiency and possibly in large scale production. A low temperature HDDR process was unreported for this purpose. In the present work, attempts of reducing a graphene oxide powder using a low temperature hydrogenation disproportionation desorption and recombination process (L-HDDR) has been carried out. A lower processing temperature in large scale production is significant as far as costs are concerned. Graphite oxide was prepared using a modified Hummers’ method and dispersed in ethanol, exfoliated using ultrasonication to produce Graphene Oxide (GO). Investigations have been carried out by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The experimental results of L-HDDR processing graphene oxide powder using unmixed hydrogen at 400°C and relatively low pressures (<2 bars) have been reported.


  • IPEN-DOC 24831

    GALDINO, GABRIEL S. ; SOBRINHO, LUIZA F. ; CRUZ, PEDRO V.D. ; CASINI, JULIO C.S.; SAKATA, SOLANGE K. ; FARIA JUNIOR, RUBENS N. . Electron beam irradiation of reduced graphene oxide-palladium nanocomposite for electrochemical supercapacitor. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: Recent work has shown that palladium nanoparticle–graphene composite can be an efficient electrode material in energy storage applications in supercapacitors. These Pd-based supercapacitors showed remarkable properties with a maximum specific capacitance of 637 F g -1 and also exhibited excellent cycle life with 91.4% of the initial specific capacitance retained after 10000 cycles. Palladium nanoparticle decorated graphene composite was synthesized via a chemical approach in a single step by the simultaneous reduction of graphene oxide and palladium chloride from the aqueous phase using ascorbic acid as reducing agent. In the present work, electron beam irradiation has been investigated as an attempt to produce graphene-palladium nanocomposites. Graphite oxide was prepared using a modified Hummers’ method and dispersed in ethanol, exfoliated using ultrasonication to produce Graphene Oxide (GO) and dried for further analysis and processing. This material was thermic reduced in high vacuum (10 -6 mbar) at various temperatures (200-600 o C) and mixed in a solution with palladium. The samples were placed in a 50 ml beaker with Pd(NO 2 ) 2 2H 2 O and were irradiated with 300kGy , dose rate 1,6 kGy s -1 . Irradiation was carried out in an electron accelerator Dynamitron de 37,5 kW (E = 1,5 MeV, 25 mA) (Radiation Dynamics Inc.), The resulting irradiated material was characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). These investigations showed that a palladium graphene mixture for supercapacitors applications is formed by electron beam irradiation.


  • IPEN-DOC 24830

    FELINTO, M.C.F.C. ; SALVADOR, F.F.S.; FRANCISCO, L.H.C.; BONTURIM, EVERTON ; BRITO, H.F.; MALTA, O.M.L.; TEOTONIO, E.E.S.. Rare earth compounds as smart materials to biological application. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: Materials containing rare earth metals are receiving increasing attention due to its wide range of potential applications, including bioanalytical, images, dye-sensitized solar cells, nanobiotechnology, catalyses among others. The distinguished spectroscopic properties of lanthanides (intense emission bands, high color purity, long lifetime and high quantum efficiency) make them strong candidates for use as markers or bio- selective detectors. Besides the interest in developing nanoparticles ( NP ) associated with biological materials continues growing rapidly . This interest is mainly motivated by the desire to simultaneously exploit the properties of both the NP and biological components in new hybrid operating devices or materials that can be applied in strategic areas. In this work, we design various materials, synthesized and characterized in several laboratories that are part of the group fluoroimunoensaios inct - INAMI and NanoBio network and that have potential to use as biological markers .An attention to materials that emit in the regions of Vis and IR as the compound of Eu and Nd compounds, RE3 + compounds covered with silica and functionalized, RE3 + complexes dispersed in polymeric matrix and have sharp, etc. luminescence will be discussed. Also it will show these nanoparticles in - action , signaling biological materials at very low concentrations , on the order of nanomolar . The principal studies are connected to the diagnostic field and has been studied mainly Leishmania , PSA , LDL, sickle cell disease, estradiol and Chagas disease.


  • IPEN-DOC 24829

    FELINTO, M.C.F.C. ; DIAS, C.L.; FRANCISCO, L.H.C.; BONTURIM, EVERTON ; BARBOSA, H.P.; BRITO, H.F.; MALTA, O.M.L.; TEOTONIO, E.E.S.. Preparation of luminescent Nd2(MoO4)3 amino-functionalized silica nanoparticles for bioconjugation. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: Nanomaterials are used in many areas of biological research. Nanoparticles can be used as active components in various functional materials and devices of interest for bio-applications. Nanoparticles have long been signaled as a potential revolution in the way we probe and interact with biological materials and organisms. This is because they are small enough to interact with their environment at a molecular level, but strong enough to maintain useful properties such as luminescence over extended periods. However, the physical properties of the host materials with nanometer dimensions may differ markedly from those of their bulk counterparts due to the particle size-dependent influences such as structure disordering and surface defects. The development of materials incorporated in the silica has been studied since these materials exhibit intrinsic luminescent properties of the inorganic part and characteristics of the silica matrix. In the present work Nd2(MoO4)3 compounds incorporated into silica particles were prepared using a microwave synthesis procedure. Then, the material was dispersed in ethyl alcohol and functionalized with APTES: 3-aminopropyltriethoxisilane. The emission spectra show broad bands when compared with the emission spectra of the own rare earth compound. The narrow lines are assigned to 4f–4f transitions from the emitting 4 F3/2 level to the 4 I9/2 and, 4 I11/2 levels, centered around 915 and 1060 respectively.. Emission spectrum of the Nd2(MoO4)3 @ Si dispersion showed an enlargement of the bands. It is also observed the broadened peak of the 4 F3/2 4 I9/2, 4 I11/2 transitions in the luminescent amino-functionalized silica particles as compared with the core compound spectrum. These materials were conjugated to anti-IgG antibody and presented high efficient performance in detect human antigen. They can concluded that particles are potential candidates for development of the bioassays acting as a biomarker.


  • IPEN-DOC 24828

    FAZOLIN, GABRIELA N. ; VARCA, GUSTAVO H.C. ; LUGAO, ADEMAR B. . The impact of physical-chemical parameters over the formation of papain nanoparticles crosslinked by radiation. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: With the advancement of research and use of nanotechnology in biomedical areas and application in different treatments the need for stable systems with low toxicity and null adverse effects becomes important. Within this context papain appears as an alternative biomolecule which is a proteolytic enzyme extract by the fruit of Carica papaya Linnaeus. Its already successfully applied in the pharmaceutical and biomedical area as a drug carrier and debriding agent for wounds. Recently, papain was developed in nanoscale using 50 Mm phosphate buffer (pH 7,2 ± 0,2), ethanol (20%, v/v) as cosolvent and 60Co as radiation source for gamma radiation (10 kGy) to promote protein crosslinking. This technique promotes papain nanoparticle sterilization and crosslinking in a single step showing that radiation is a promising technique for the development of nanoparticles for biomedical use. However, important parameters such as the influence of physical-chemical parameters over nanoparticle formation remains unexplored and unclear. Therefore, this work aimed to evaluate the influence of pH and temperature over papain nanoparticle formation including buffer molarity and different temperatures throughout the synthesis and irradiation process. Nanopapain was synthetized as above-mentioned however phosphate buffer was used in a range of 1 to 50 mM and ultrapure water in presence of ethanol and irradiated at 10 kGy. The influence of temperature was evaluated by performing the synthesis at -20, 0 and 20 °C. Additionally, it was verified the sterility of the material and its stability over time. The hydrodynamic radius and crosslinking were evaluated by dynamic light scattering and fluorescence measurements respectively. The pH range was influenced by buffer molarity, thus, lower molarities led to a final pH of 5 and the higher molarities around 7. Bityrosine formation was influenced by the pH range and increased when synthesis was performed near optimal pH (7 for papain), although particle size didn’t undergo any changes as a result of the pH changes. On the other hand, enzymatic activity was less affected by the process maintain about 80% of the native enzymatic activity only when synthesis was carried out in 50 mM phosphate buffer. With regard to temperature as the temperature increased the levels of crosslinking also increased in the order of 20>0ºC>-20ºC. In conclusion nanoparticle size was not influenced by the temperature shift. Concerning enzymatic activity samples irradiated under ice-cold conditions presented decreased bioactivity loss if compared to the samples irradiated at room temperature. After an evaluation of the results, the study revealed that samples synthetized with buffer molarity of 50 Mm (pH 7,2 ± 0,2) and 0ºC would promote higher crosslinking levels and less enzymatic activity decrease.


  • IPEN-DOC 24827

    CORDEIRO, GUILHERME L. ; CAMARGO, ELAINE F. de ; USSUI, VALTER ; LIMA, NELSON B. de ; NETO, ALMIR O. ; LAZAR, DOLORES R.R. . Engineering graphene surface toward design of aggregation-resistant catalyst supports for advanced energy conversion. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: Graphene has been considered an emerging fuel cell catalyst support due to its excellent chemical and electrical properties. The evaluation of the unit activity on each catalytic site (intrinsic) of low-loading supported metal nanoparticles (NPs), however, is often hampered by face-to-face aggregation of graphene sheets. Herein, we demonstrate the critical role of the expansion between sheets in a pivotal electrocatalytic process for green energy conversion through ethanol oxidation in acid medium. In order to reduce mass-transport resistances and incomplete utilization of the supported NPs, a one-step design strategy is proposed for tuning a desired physicochemical property of graphene: surface area. This step is based on the principle that the apparent activity is governed by the extrinsic activity, i . e ., the number of exposed active sites for a particular mass loading. Our design principle is achieved by a two-stage method involving a chemical delamination process of graphite (1) with an in situ surfactant functionalization/intercalation–reduction approach (2). As a result, not only an interlayer expansion was attained but also a short-ranged layered structure was assembled. This structural reorganization substantially affected the ethanol oxidation reaction (EOR) over platinum NPs. The unique nanoarchitecture provided a high density of EOR active sites, which incurred in a specific current value increased by about 2.5 and 5.4 times compared to platinum supported on state-of-the-art carbon black and restacked graphene, respectively.


  • IPEN-DOC 24826

    CAMARGO, ELAINE F. de ; CORDEIRO, GUILHERME L. ; SANTOS, MONIQUE C.L. ; PEREIRA, CONRADO de V. ; USSUI, VALTER ; LIMA, NELSON B. de ; NETO, ALMIR O. ; LAZAR, DOLORES R.R. . Synthesis of cerium oxide nanopowders for improving catalysts electroactivity in direct ethanol fuel cells. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: The search for alternative direct ethanol fuel cell catalyst supports to improve platinum electrocatalysis requires the development of novel nanostructured conducting materials. In order to boost energy conversion efficiencies, high surface-area supports with enhanced oxophilicity have been addressed. This procedure might aid breaking the C–C bond and the poisoning of platinum by strongly adsorbed species coming from the dissociative adsorption of ethanol. In the present work, synthetic cerium oxide nanopowders were compared to state-of-the-art carbon black supports for the ethanol oxidation reaction (EOR). Cerium oxides were prepared via a simple chemical precipitation method using ammonium hydroxide as a precipitant agent and the effect of thermal treatment of the synthesized nanopowders was investigated. Microstructural analyses revealed an increase in crystallite size from 8.1 to 25.7 nm after heating from 400 to 800 °C, respectively. Supported catalysts containing 20 wt.% Pt were prepared by a sodium borohydride impregnation–reduction method, in aqueous solution, at room temperature. Electrochemical measurements of the EOR showed highest electrocatalytic activity over samples calcined at 400 °C as a result of a combinantion between an appropriate nano-scaled structure and oxygen transport in cerium oxide.


  • IPEN-DOC 24825

    BATISTA, JORGE G.S.; BARROS, JANAINA A.G. ; VARCA, GUSTAVO H.C. ; ROGERO, SIZUE O. ; CAVALCANTE, ADRIANA K. ; MAZIERO, JOANA S.; ROGERO, JOSE R. ; LUGAO, ADEMAR B. . Evaluation of the in vitro and in vivo toxicity of gold nanoparticles synthesized by green nanotechnology. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: Researchers and laboratories around the world have studied gold nanoparticles. In medicine, several studies demonstrate the applicability of gold nanoparticles (AuNPs) in the treatment and diagnosis of cancer. Green nanotechnology uses phytochemical agents to synthesize and stabilize nanoparticles. The phytochemical epigallocatechin-gallate (EGCG) reduces and stabilize gold nanoparticles by functionalizing the surface of the molecule. Such chemical groups allow binding to overexpressed receptors on some types of tumors as demonstrated in studies performed with PC3 prostate cancer cells. With the advancement of nanotechnology, a large number of nanoparticles are produced on a daily basis. However apart from their possible applications it is necessary to evaluate the environmental impact of these molecules as well as find ways for proper disposal. The embryonic zebrafish (Danio rerio) trial has recently emerged as an interesting method for evaluating in vivo nanotoxicity providing a more complex system analysis than in typical cell cultures and less expensive if compared to large-scale biocompatibility studies performed in rats and mice. The objective of this study was to evaluate the in vitro and in vivo toxicity of EGCG-AuNPs by means of the cytotoxicity by neutral red uptake methodology according to the International Standard Organization [ISO 10993-5, 2009] and in vivo test based on the OECD guideline on Fish Embryo Toxicity Test (FET) (OECD, 2013). The spectrophotometric band at 535 nm observed is characteristic of the formation of AuNPs. Nanoparticles synthesized with EGCG presented a size of 32 ± 4 nm as determined by transmission electron microscopy and the hydrodynamic diameter of these particles was about 60 ± 18 nm obtained by dynamic light scattering. The EGCG-AuNPs showed no cytotoxicity up to 4.2 μg.L-1. In the FET test regarding the acute ecotoxicity assay the LC50/96 hours revealed no toxicity at concentrations up to 1.8 mM.


  • IPEN-DOC 24824

    BARTOLOMEI, SUELLEN S.; MACHADO, MESSIAS S.; SANTANA, JULYANA G. ; MOURA, ESPERIDIANA ; WIEBECK, HELIO. Recycling of plastic cups and packaging of EPS to obtain nanocomposite with nanoclay and plaster. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: Polystyrene is a polymer defined as brittle due to its mechanical properties, but still widely used industrially for its cost and processability. However, the fragility restricts its use in engineering applications. To improve the material, the addition of a plasticizer is recommended, because it acts between the polymer chains increasing its mobility and delaying the growth of cracks. Another method for improving the mechanical properties of a polymer is the use of a reinforcing phase thereby generating a nanocomposite. In this work the polystyrene of disposable plastic cups and expanded polystyrene packages were recycled using ethyl acetate. Together with the solvent, glycerin was added to plasticize the recycled polymer. Therefore, a solution was made containing recycled polystyrene and glycerin, this solution was allowed to stand until all solvent evaporated and a rigid film was obtained. Then, to improve the mechanical properties, three types of composite were prepared by melt extrusion, using a twin screw extruder machine. First, the recycled polystyrene of the cups was mixed with nanoclay (5% wt), afterwards the recycled polystyrene of the cups was mixed with nanoclay (5% wt) and gypsum (5% wt) and, in the third composite, it were mixed the recycled expanded polystyrene with gypsum particles (10% wt). Specimens were injected and tensile tests were performed to compare the mechanical properties of the composites obtained.


  • IPEN-DOC 24823

    ALCANTARA, MARA T.S. ; COUTINHO, CAMILA M. ; OLIVEIRA, MARIA J.A. ; MUNHOZ, MARA M.L. ; LUGAO, ADEMAR B. . Obtaining of a hydrogel gel dressing of PVP with nanosilver for deep and complex wounds. In: PAN AMERICAN CONGRESS OF NANOTECHNOLOGY, 1st, 27-30 de novembro, 2017, Guarujá, SP. Abstract... 2017.

    Abstract: Introduction Chronic and some acute wounds of difficult treatment that challenge medical and nursing teams are classificadas como Complex wound (Ferreira et al., 2006). Due to the long cicatrization time and successive relapses, cause a problem social on patients' lives and economic a major impact on the health system (Azoubel et al., 2017). Throughout the world there has been a growing interest in the use of hydrogels for application as dressings in view that they are able to maintain the humidity of the wound, favoring the epithelialization of lesions and favoring the relief of pain. On the other hand, silver is an agent that has been used since ancient times, but it has been replaced after the discovery of antibiotics. However, with the advent of bacterial resistance to antibiotics and the development of nanotechnology, it has regained notoriety, since the clinical incidence of silver resistance remains low (Chopra, 2007).In addition to its bactericidal properties, silver nanoparticles (AgNPs) also have anti-inflammatory properties, which, allied to hydrogels’ advantages of maintaining moisture in the wound, represent a great advantage for use as a dressing. However, conventional dressings do not address the need for direct contact with the wound when this is a deep wound. The objective of this work was to obtain a hydrogel gel with silver nanoparticles for wound dressing, synthesized in situ by using ionizing radiation for gelation (crosslinking of PVP-Ag+ aqueous solution), synthesis of the AgNPs and simultaneous sterilization of the final product, able to fill the cavity of deep wounds, thus allowing the direct contact of the dressing with the lesioned walls. Methodology The gel was prepared from the mixture of PVP with plasticizers, water, and silver ions; next, the mixture was irradiated / sterilized by gamma-irradiation from a 60-Co source at a dose of 20 kGy. . Results The result of this work is a viscous and transparent gel (Fig. 1), easy to be applied, able to control pain since it reduces the local temperature due to evaporation of water. Fig. 1 - Hydrogel gel of PVP with silver nanoparticles for wound dressing. The studies are being continued with the aim of evaluating its stability and bactericidal activity.


  • IPEN-DOC 24693

    OLIVEIRA, L.N. de; NASCIMENTO, E.O. do; SCHIMIDT, F.; ANTONIO, P.L. ; CALDAS, L.V.E. . Assessment of Ethylene Vinyl-Acetato Copolymer (EVA) samples bombarded by gamma radiation via linearity analyses. Journal of Physics: Conference Series, v. 975, p. 1-4, 2018. DOI: 10.1088/1742-6596/975/1/012041

    Abstract: Materials with the potential to become dosimeters are of interest in radiation physics. In this research, the materials were analyzed and compared in relation to their linearity ranges. Samples of ethylene vinyl-acetate copolymer (EVA) were irradiated with doses from 10 Gy to 10 kGy using a 60Co Gamma-Cell system 220 and evaluated with the FTIR technique. The linearity analyses were applied through two methodologies, searching for linear regions in their response. The results show that both applied analyses indicate linear regions in defined dose interval. The radiation detectors EVA can be useful for radiation dosimetry in intermediate and high doses.


  • IPEN-DOC 24822

    WEBLER, G.D.; RODRIGUES, W.C.; SILVA, A.E.S.; SILVA, A.O.S.; FONSECA, E.J.S.; DEGENHARDT, M.F.S.; OLIVEIRA, C.L.P.; OTUBO, L. ; BARROS FILHO, D.A.. Use of micrometric latex beads to improve the porosity of hydroxyapatite obtained by chemical coprecipitation method. Applied Surface Science, v. 436, p. 141-151, 2018. DOI: 10.1016/j.apsusc.2017.11.218

    Abstract: Hydroxyapatite is one of the most important biomaterials whose application mainly extends to implants and drug delivery. This work will discuss the changes in the pore size distribution of hydroxyapatite when there are latex beads present during the synthesis. These changes were monitored using different techniques: small angle X-ray scattering, X-ray diffraction, thermal gravimetrical analysis, N2 adsorption, scanning and transmission electron microscopy. Latex beads and hydroxyapatite form a single nanocomposite with well-distinguished inorganic and organic phases. Latex bead removal in the temperature range of 300–600 ◦C did not modify the original crystalline structure of hydroxyapatite. However, the latex beads favored an increase in the adsorption capacity of mesopores at temperatures higher than their glassy transition (Tg). The main result of this research work consists on the increase of surface area and pore size distribution obtained after the removal of latex beads template. Latex beads have been used in a different approach changing the porosity of hydroxyapatite scaffolds not only introducing new routes for cell integration but also broadening the pore size distribution which can result in a more high efficiency for drug release in living cells.


  • IPEN-DOC 24821

    JIMENEZ-VILLAR, E. ; XAVIER, M.C.S.; RAMOS, J.G.G.S.; WETTER, N.U. ; MESTRE, VALDECI; MARTINS, WELITON S.; BASSO, GABRIEL F.; ERMAKOV, VICTOR A.; MARQUES, FRANCISCO C.; SA, GILBERTO F. de. Localization of light: beginning of a new optics. In: GALVEZ, ENRIQUE J. (Ed.); ANDREWS, DAVID L. (Ed.); GLUCKSTAD, JESPER (Ed.) Complex Light and Optical Forces, 12th, January 27 - February 01, 2018, San Francisco, California, USA. Proceedings... Bellingham, WA, USA: Society of Photo-optical Instrumentation Engineers, 2018. p. 1054905-1 - 1054905-11. (SPIE Proceedings Series, 10549). DOI: 10.1117/12.2288993

    Abstract: In recent years, there has been a dramatic progress in the photonics field of disordered media, ranging from applications in solar collectors, photocatalyzers, random lasing, and other novel photonic devices, to investigations into fundamental topics, such as localization of light and other phenomena involving photon interactions. Anderson localization of light is an open researcher frontier, which has greatly attracted the attention of researchers in the past few decades. In this work, we study the transport of light in a strongly disordered optical medium composed by core-shell nanoparticles (TiO2@Silica) suspended in ethanol solution. We demonstrate the crossover from a diffusive transport to a localization transition regime as TiO2@Silica nanoparticle concentration is increased. A striking phenomenon of enhanced absorption, mainly near the input border, arises at the localization transition, from which an increase of refractive index was inferred. An increase of the density of localized states and absorption near the input border is reported when the incidence angle is increased. The specular reflection, measured for the photons that enter the sample, is considerably lower than the effective internal reflection undergone by the coherently backscattered photons in the exact opposite direction, indicating a nonreciprocal propagation of light (parity-symmetry breaking). A theoretical simulation, performed through random-matrix theory, agrees satisfactorily with the experimental results, showing the generality of this approach to address transport phenomena.


  • IPEN-DOC 24820

    RAHMAN, S.U.; MOSCA, R.C. ; REDDY, S.G.; NUNEZ, S.C.; ANDREANA, S.; MANG, T.S.; ARANY, P.R.. Learning from clinical phenotypes: low-dose biophotonics therapies in oral diseases. Oral Diseases, v. 24, n. 1-2, p. 261-276, 2018. DOI: 10.1111/odi.12796

    Abstract: This narrative review on the use of biophotonics therapies for management of oral diseases is written as a tribute to Prof. Crispian Scully. His seminal contributions to the field are highlighted by the detailed, comprehensive description of clinical presentations of oral diseases. This has enabled a more thorough, fundamental understanding of many of these pathologies by research from his group as well as inspired mechanistic investigations in many groups globally. In the same vein, a major emphasis of this narrative review is to focus on the evidence from human case reports rather than in vitro or in vivo animal studies that showcases the growing and broad impact of biophotonics therapies. The similarities and differences between two distinct forms of low-dose biophotonics treatments namely photodynamic therapy and photobiomodulation therapy are discussed. As evident in this review, a majority of these reports provide promising evidence for their clinical efficacy. However, a lack of adequate technical details, precise biological rationale, and limited outcome measures limits the current utility of these treatments. Future investigations should attempt to address these shortcomings and develop better designed, rigorous, controlled studies to fully harness the tremendous potential of low-dose biophotonics therapies.


  • IPEN-DOC 24819

    OLIVEIRA, MARA C.L. de; CORREA, OLANDIR V. ; ETT, BARDIA; SAYEG, ISAAC J.; LIMA, NELSON B. de ; ANTUNES, RENATO A.. Influence of the tungsten content on surface properties of electroless Ni-W-P coatings. Materials Research - Ibero-American Journal of Materials, v. 21, n. 1, p. 1-13, 2018. DOI: 10.1590/1980-5373-MR-2017-0567

    Abstract: Ternary Ni-W-P films were produced by electroless deposition using baths with different tungsten concentrations. After deposition, the coated surfaces were annealed at 400°C for 1h. Surface morphology and film composition in the as-plated condition were assessed by SEM and EDS analyses, respectively. The crystalline phases after annealing were investigated by X-ray diffraction (XRD). Nanoindentation tests were performed to assess the mechanical properties of the deposited films. Surface roughness was determined by confocal laser scanning microscopy (CLSM). Friction coefficient was evaluated by reciprocating were tests in a nanotribometer. The corrosion behavior was evaluated by potentiodynamic polarization curves. The results showed that the surface morphology, crystallization behavior and corrosion resistance were affected by the tungsten content in the film. The best corrosion performance was obtained for the ternary films after annealing. Hardness, surface roughness and friction coefficient were dependent of the tungsten concentration in the film.


  • IPEN-DOC 24818

    IZIDORO, JULIANA de C. ; MIRANDA, CAIO da S. ; GUILHEN, SABINE N. ; FUNGARO, DENISE A. ; WANG, SHAOBIN. Treatment of coal ash landfill leachate using zeolitic materials from coal combustion by-products. Advanced Materials and Technologies for Environmental Applications, v. 2, n. 1, p. 177-186, 2018.

    Abstract: Three different zeolitic materials derived from coal combustion by-products (CCBs) were used to treat local coal ash landfill leachate at the same power plant. The zeolitic materials properties were characterized in terms of mineralogical composition (XRD), chemical composition (XRF), total carbon content, morphological analysis (SEM), specific surface area (BET method), cation exchange capacity (CEC), loss of ignition, pH, conductivity and bulk density. XRD indicated that sodalite zeolite was formed in all the samples after hydrothermal activation of CCBs. One zeolitic product from baghouse fly ash (ZFB) presented the lowest SiO2/Al2O3 ratio, highest CEC and specific surface area, thus having a high capacity in removal of heavy metal pollutants. The zeolitic products were efficient to reduce arsenic concentration to a value below the legislation. All zeolitic materials also showed a significant removal of Ni, Cd, Zn and Co except of Cr at a dose of 10 g L-1. Thus, this work provides a sustainable strategy to resolution of solid waste from power plants.


  • IPEN-DOC 24817

    ICHIKAWA, RODRIGO U. ; ROCA, ALEJANDRO G.; LOPEZ-ORTEGA, ALBERTO; ESTRADER, MARTA; PERAL, INMA; TURRILLAS, XABIER; NOGUES, JOSEP. Combining X-Ray whole powder pattern modeling, rietveld and pair distribution function analyses as a novel bulk approach to study interfaces in heteronanostructures: oxidation front in FeO/Fe3O4 core/shell nanoparticles as a case study. Small, v. 14, n. 30, p. 1800804-1 - 1800804-11, 2018. DOI: 10.1002/smll.201800804

    Abstract: Understanding the microstructure in heterostructured nanoparticles is crucial to harnessing their properties. Although microscopy is ideal for this purpose, it allows for the analysis of only a few nanoparticles. Thus, there is a need for structural methods that take the whole sample into account. Here, a novel bulk‐approach based on the combined analysis of synchrotron X‐ray powder diffraction with whole powder pattern modeling, Rietveld and pair distribution function is presented. The microstructural temporal evolution of FeO/Fe3O4 core/shell nanocubes is studied at different time intervals. The results indicate that a two‐phase approach (FeO and Fe3O4) is not sufficient to successfully fit the data and two additional interface phases (FeO and Fe3O4) are needed to obtain satisfactory fits, i.e., an onion‐type structure. The analysis shows that the Fe3O4 phases grow to some extent (≈1 nm) at the expense of the FeO core. Moreover, the FeO core progressively changes its stoichiometry to accommodate more oxygen. The temporal evolution of the parameters indicates that the structure of the FeO/Fe3O4 nanocubes is rather stable, although the exact interface structure slightly evolves with time. This approach paves the way for average studies of interfaces in different kinds of heterostructured nanoparticles, particularly in cases where spectroscopic methods have some limitations.


  • IPEN-DOC 24816

    FERREIRA, MERILYN S. ; PASK, HELEN M.; WETTER, NIKLAUS U. . Intracavity diode-side-pumped Raman laser at 1147 nm and 1163 nm. In: KUDRYASHOV, ALEXIS V. (Ed.); PAXTON, ALAN H. (Ed.); ILCHENKO, VLADIMIR S. (Ed.) LASER RESONATORS, MICRORESONATORS, AND BEAM CONTROL, 20th, January 27 - February 01, 2018, San Francisco, California, USA. Proceedings... Bellingham, WA, USA: Society of Photo-optical Instrumentation Engineers, 2018. p. 1051816-1 - 1051816-9. (SPIE Proceedings Series, 10518). DOI: 10.1117/12.2290596

    Abstract: Wavelengths in the yellow-orange range are of significant interest due to their application potential in the medical and biomedical areas, as well as for applications in laser displays and in remote sensing. These wavelengths can be obtained by frequency-doubling or sum-frequency generation of lasers with near-IR emission like VCSELS, fiber lasers, and OPOs. However, all these alternatives have several limitations that justify the development of alternative methods. As a possible solution for these limitations, a configuration of an intracavity converted Raman laser may be developed to obtain two wavelengths, 1163 nm, and 1147 nm, with high efficiency and good beam quality. This paper presents a configuration of a side-pumped intracavity converted Raman laser to achieve these objectives. A Nd:YLiF4 crystal was used as fundamental wavelength gain crystal. The side-pumped configuration guarantees practicability and cost reduction while allowing good efficiency and fundamental mode laser beam. The intracavity conversion configuration allows high fundamental wavelength power at the Stokes crystal in order to facilitate the obtention of the Stokes wavelengths and enables optimization of its efficiency. As a result an output power at 1163 nm of 3.8 W in the multimode regime was obtained, corresponding to a pump to Stokes efficiency of 9.6%. The TEM00 diode to Stokes efficiency was 7%. For the emission at 1147 nm, 1.5W of output power with a diode to Stokes efficiency of 3.7% was achieved. The side-pumped Nd:YLF/KGW intracavity Raman laser configuration is reported for the first time, to our knowledge.


  • IPEN-DOC 24815

    FERREIRA, EDUARDO G.A. ; YOKAICHIYA, FABIANO; MARUMO, JULIO T. ; VICENTE, ROBERTO ; GARCIA-MORENO, FRANCISCO; KAMM, PAUL H.; KLAUS, MANUELA; RUSSINA, MARGARITA; GUNTHER, GERRIT; JIMENEZ, CATALINA E.; FRANCO, MARGARETH K.K.D. . Influence of the irradiation in cement for the Brazilian radioactive waste repositories: characterization via X-ray diffraction, X-ray tomography and quasielastic neutron scattering. Physica B: Condensed Matter, p. 1-6, 2018. DOI: 10.1016/j.physb.2018.01.018

    Abstract: Powerful characterization techniques have allowed detailing the investigation of cementitious materials that must endure for millennia as an engineered barrier in radioactive waste repositories. Cement is used in the repository, as waste immobilization matrix, structural material and an additional barrier against the contact of the waste with the biosphere. The material properties have to comply with requirements in respect to a number of parameters including homogeneity, permeability, and leachability, as well as withstand mechanical stress, heat, chemical and microbial attack, and the effects of ionizing radiation. The present study aims to investigate the behavior of cementitious materials contributing to the understanding of the processes that occur in hydrated cement under the environmental conditions of a repository and to estimate the durability of these materials. In this study was observed the changes caused by radiation, to which the material was exposed. A reference Portland cement paste and grout samples were compared with irradiated ones by X-ray diffraction and Tomography. Original and valuable results concerning the investigation of the influence of radiation on cement samples were also obtained by quasielastic scattering. These results are not accessible by others techniques.


  • IPEN-DOC 24814

    COSTA, PRISCILA ; RAELE, MARCUS P. ; SAMAD, RICARDO E. ; MACHADO, NOE G.P. ; VIEIRA JUNIOR, NILSON D. ; GENEZINI, FREDERICO A. . Femtosecond pulsed laser deposition of a boron thin film aiming at the development of a low-cost neutron detector. In: KAIERLE, STEFAN (Ed.); HEINEMANN, STEFAN W. (Ed.) HIGH-POWER LASER MATERIALS PROCESSING: APPLICATIONS, DIAGNOSTICS, AND SYSTEMS, 7th, January 27 - February 01, 2018, San Francisco, California, USA. Proceedings... Bellingham, WA, USA: Society of Photo-optical Instrumentation Engineers, 2018. p. 105250J-1 - 105250J-7. (SPIE Proceedings Series, 10525). DOI: 10.1117/12.2285896

    Abstract: Boron thin films were produced using femtosecond pulsed laser deposition aiming at the development of a neutron detector. As neutrons have no charge, in order to detect this particle converter materials are applied, promoting nuclear reactions that result in the emission of charged particles, allowing the neutrons presence to be indirectly inferred. Among the possible conversion materials, 10B has a considerable cross section for thermal neutrons and accessible cost. Furthermore, the nuclear reaction produces easily detectable alpha particles, making it a rational option to develop a low cost and portable neutron detector. The boron ablation threshold fluence has been measured by the Diagonal Scan (Dscan) technique that resulted in the minimum laser energy value of 17.7 (6) μJ and fluence of 5.63(19) J/cm2. Boron deposition was performed varying the pulse energy and deposition duration. The growth rate, morphological and physical aspects of the boron pulsed laser deposition were characterized by a Scanning Electron Microscope and an optical profilometer. The films surfaces have a flaky aspect with eventual droplets which had decayed overtime to a more smooth surface. The studied parameters allowed producing a boron coating with the optimal thickness in order to minimize self-absorption effect in the film, thus increasing efficiency.


  • IPEN-DOC 24812

    ZARPELON, L.M.C. ; BANCZEK, E.P. ; MARTINEZ, L.G. ; LIMA, N.B. ; COSTA, I. ; FARIA, R.N. . Effects of magnesium content on structure and electrochemical properties of La-Mg-Pr-Al-Mn-Co-Ni hydrogen storage alloys. Advances in Materials Science and Engineering, n. 9284943, p. 2-11, 2018. DOI: 10.1155/2018/9284943

    Abstract: The discharge capacity, microstructures, and corrosion resistance of some as-cast alloys represented by the formula La0.7−xMgxPr0.3Al0.3Mn0.4Co0.5Ni3.8, where x = 0.0, 0.1, 0.3, 0.5, and 0.7, were investigated by SEM/EDX, XRD, and electrochemical measurements. The partial substitution of La by Mg refined the grain structure while the total substitution changed it from equiaxed to columnar. Three phases were detected: a major phase (M), a grey phase (G), and a dark phase (D). The compositions analyzed by EDX suggested that the M phase was close to a LaNi5 phase. With the increase of the Mg content, the analyses revealed a G phase with composition close to a RMg2Ni9 (R = La,Pr) and a D phase close to a MgNi2 phase. The XRD analysis and Rietveld refinement corroborated the EDX results. The corrosion resistance of the alloys was evaluated in 6.0 mol·L−1 KOH solution, and the results showed that the substitution of La by Mg was beneficial for this alloy property. Nevertheless, Mg addition was deleterious to the discharge capacity of the electrodes.


  • IPEN-DOC 24811

    ZAMPIVA, RUBIA Y.S.; ACAUAN, LUIZ H.; VENTURINI, JANIO; GARCIA, JOSE A.M.; SILVA, DIEGO S. da ; HAN, ZHAOHONG; KASSAB, LUCIANA R.P.; WETTER, NIKLAUS U. ; AGARWAL, ANURADHA; ALVES, ANNELISE K.; BERGMANN, CARLOS P.. Tunable green/red luminescence by infrared upconversion in biocompatible forsterite nanoparticles with high erbium doping uptake. Optical Materials, v. 76, p. 407-415, 2018. DOI: 10.1016/j.optmat.2018.01.004

    Abstract: Nanoparticles represent a promising platform for diagnostics and therapy of human diseases. For biomedical applications, these nanoparticles are usually coated with photosensitizers regularly activated in a spectral window of 530–700 nm. The emissions at 530 nm (green) and 660 nm (red) are of particular interest for imaging and photodynamic therapy, respectively. This work presents the Mg2SiO4:Er3+ system, produced by reverse strike co-precipitation, with up to 10% dopant and no secondary phase formation. These nanoparticles when excited at 985 nm show upconversion emission with peaks around 530 and 660 nm, although excitation at 808 nm leads to only a single emission peak at around 530 nm. The direct upconversion of this biomaterial without a co-dopant, and its tunability by the excitation source, renders Mg2SiO4:Er3+ nanoparticles a promising system for biomedical applications.


  • IPEN-DOC 24808

    YAMAMURA, HIROCHI; SILVA, VICTOR H.P. da; RUIZ, PEDRO L.M.; USSUI, VALTER ; LAZAR, DOLORES R.R. ; RENNO, ANA C.M.; RIBEIRO, DANIEL A.. Physico-chemical characterization and biocompatibility of hydroxyapatite derived from fish waste. Journal of the Mechanical Behavior of Biomedical Materials, v. 80, p. 137-142, 2018. DOI: 10.1016/j.jmbbm.2018.01.035

    Abstract: The aim of this study was to synthesize hydroxyapatite (HAP) powder from fish waste. The powder was characterized through X-ray diffraction, Fourier transform infrared spectroscopy, ion exchange chromatography, scanning electron microscopy and plasma emission spectrometry. The cyto- and genotoxicity was carried out to demonstrate biocompatibility in vivo by means of rat subcutaneous tissue test. The results showed that the visible crystalline nature of typical apatite crystal structure when they were calcined at 800 °C. Infrared spectroscopy analysis showed similar composition to HAP standard with the presence of carbonate ion demonstrated by wave number values of 871 cm−1 and 1420 cm−1 for calcinations at 800 °C. The scanning electronmicrographies depicted the crystal morphology and porous nature with average pore size of ~10 µm. Plasma emission spectrometry and ion exchange chromatography confirmed the presence of Ca and P in the samples. The mean of calcium content was 36.8; Mg was 0.8, Na was 0.7 and K was 0.5. Rat subcutaneous tissue test revealed that HAP presented biocompatibility. Furthermore, the lack of cyto- and genotoxicity in blood, liver, kidney and lung were noticed after 30 days of HAP implantation. Taken together, our results demonstrated that HAP from fish waste exhibits a great potential for using as biomaterial since is represents a simple, effective, low-cost process and satisfactory degree of biocompatibility.


  • IPEN-DOC 24807

    WETTER, NIKLAUS U. ; BERECZKI, ALLAN ; PAES, JOAO P.F. . Quasi-three level Nd:YLF fundamental and Raman laser operating under 872-nm and 880-nm direct diode pumping. In: CLARKSON, W.A. (Ed.); SHORI, RAMESH K. (Ed.) SOLID STATE LASERS XXVII: TECHNOLOGY AND DEVICES, January 27 - February 01, 2018, San Francisco, California, USA. Proceedings... Bellingham, WA, USA: Society of Photo-optical Instrumentation Engineers, 2018. p. 105111S-1 - 105111S7. (SPIE Proceedings Series, 10511). DOI: 10.1117/12.2290444

    Abstract: Nd:YLiF4 is the gain material of choice whenever outstanding beam quality or a birefringent gain material is necessary such as in certain applications for terahertz radiation or dual-frequency mode-locking. However, for high power CW applications the material is hampered by a low thermal fracture threshold. This problem can be mitigated by special 2D pump set-ups or by keeping the quantum defect to a minimum. Direct pumping into the upper laser level of Nd:YLiF4 is usually performed at 880 nm. For quasi-three level laser emission at 908 nm, direct pumping at this wavelength provides a high quantum defect of 0.97, which allows for very high CW pump powers. Although the direct pumping transition to the upper laser state at 872 nm has a slightly smaller quantum defect of 0.96, its pump absorption cross section along the c-axis is 50% higher than at 880 nm, leading to a higher absorption efficiency. In this work we explore, for the first time to our knowledge, 908 nm lasing under 872 nm diode pumping and compare the results with 880 nm pumping for quasicw and cw operation. By inserting a KGW crystal in the cavity, Raman lines at 990 nm and 972 nm were obtained for the first time from a directly pumped 908 nm Nd:YLF fundamental laser for both quasi-cw and cw conditions.


  • IPEN-DOC 24806

    WETTER, NIKLAUS U. ; BERECZKI, ALLAN ; FERREIRA, AMAURI A. . Dynamically stable operation of a 100-watt level CW single frequency ring laser at 1064 nm. In: KUDRYASHOV, ALEXIS V. (Ed.); PAXTON, ALAN H. (Ed.); ILCHENKO, VLADIMIR S. (Ed.) LASER RESONATORS, MICRORESONATORS, AND BEAM CONTROL, 20th, January 27 - February 01, 2018, San Francisco, California, USA. Proceedings... Bellingham, WA, USA: Society of Photo-optical Instrumentation Engineers, 2018. p. 1051811-1 - 1051811-7. (SPIE Proceedings Series, 10518). DOI: 10.1117/12.2290480

    Abstract: For high-resolution spectroscopy, a stable, narrow linewidth and high power output laser is desirable in order to pump different types of resonant optical parametric oscillators, which is the goal of the present work. Typical single frequency pump lasers are in the range of 10 watt output power whereas, depending on application and OPO type, higher power (>20 W) is desirable. Here we demonstrate a high-power single frequency laser based on off the shelf standard Nd:YAG pump modules. Two closely spaced, diode-side-pumped Nd:YAG rods were used in a mode-filling configuration to form a CW polarized ring resonator with TEM00 beam quality and output power of 105 W. The output power achieved is, to our knowledge, the highest reported for continuous polarized, fundamental-mode ring lasers using standard side-pumped Nd:YAG modules. The resonator allowed for power tuning over a large dynamic range and achieved excellent beam quality, using a half wave plate between both rods for birefringence compensation. Single frequency operation was achieved using a TGG crystal and an etalon, with a preliminary output power of 40 W.


  • IPEN-DOC 24805

    VALENCA, JOAO V.B.; SILVA, ANIELLE C.A.; DANTAS, NOELIO O.; CALDAS, LINDA V.E. ; DERRICO, FRANCESCO; SOUZA, SUSANA O.. Optically stimulated luminescence of the [20% Li2CO3 + x% K2CO3 + (80 - x)% B2O3] glass system. Journal of Luminescence, v. 200, p. 248-253, 2018. DOI: 10.1016/j.jlumin.2018.03.060

    Abstract: This study analyzed the optically simulated luminescence (OSL) of borate glasses containing lithium carbonate and potassium carbonate. Borate glasses present desirable characteristics for dosimetry and have been extensively analyzed in relation to thermoluminescence (TL). Five formulations containing 20% of Li2CO3 and different amounts of B2O3 and K2CO3 were produced. Their OSL signal was analyzed following exposure to beta particles. The decay pattern typical of continuous wave stimulation (CW-OSL) was observed for all compositions. Depending on the parameter chosen to normalize the dose-response curve, the sensitivity range changed. If the initial OSL intensity was chosen as reference, the composition containing 65% B2O3 and 15% K2CO3 (named L15KB) presented the most intense signal. However, if the total area below the curve was considered, the composition containing 70% B2O3 and 10% K2CO3 (named L10KB) was the most sensitive. A comparison of the OSL decay for the two quoted compositions, after pre-heating to 200 °C for 10 s prior to the OSL readout, showed a slight change in the decay pattern compared to the absence of pre-heating. The pre-heating treatments also showed the correlation between the shallow traps and the fast component of the OSL decay for L15KB. For all compositions, an increase in dose implied an increase in emitted signal, and no saturation was observed between 0.1 Gy and 7 Gy.


  • IPEN-DOC 24804

    UMBEHAUN, PEDRO E. ; TORRES, WALMIR M. ; SOUZA, JOSE A.B. ; YAMAGUCHI, MITSUO ; SILVA, ANTONIO T. e ; MESQUITA, ROBERTO N. de ; SCURO, NIKOLAS L. ; ANDRADE, DELVONEI A. de . Thermal hydraulic analysis improvement for the IEA-R1 research reactor and fuel assembly design modification. World Journal of Nuclear Science and Technology, v. 8, n. 2, p. 54-69, 2018. DOI: 10.4236/wjnst.2018.82006

    Abstract: This paper presents the sequence of activities to improve the thermal hydraulic analysis of the IEA-R1 research reactor to operate in safe conditions after power upgrade from 2 to 5 MW and core size reduction from 30 to 24 fuel assemblies. A realistic analysis needs the knowledge of the actual operation conditions (heat flow, flow rates) beyond the geometric data and the uncertainties associated with manufacturing and measures. A dummy fuel assembly was designed and constructed to measure the actual flow rate through the core fuel assemblies and its pressure drop. First results showed that the flow distribution over the core is nearly uniform. Nevertheless, the values are below than the calculated ones and the core bypass flow rate is greater than those estimated previously. Based on this, several activities were performed to identify and reduce the bypass flow, such as reduction of the flow rate through the sample irradiators, closing some unnecessary secondary holes on the matrix plate, improvement in the primary flow rate system and better fit of the core components on the matrix plate. A sub-aquatic visual system was used as an important tool to detect some bypass flow path. After these modifications, the fuel assemblies flow rate increased about 13%. Additional tests using the dummy fuel assembly were carried out to measure the internal flow distribution among the rectangular channels. The results showed that the flow rate through the outer channels is 10% - 15% lower than the internal ones. The flow rate in the channel formed between two adjacent fuel assemblies is an estimated parameter and it is difficult to measure because this is an open channel. A new thermal hydraulic analysis of the outermost plates of the fuel assemblies takes into account all this information. Then, a fuel design modification was proposed with the reduction of 50% in the uranium quantity in the outermost fuel plates. In order to avoid the oxidation of the outermost plates by high temperature, low flow rate, a reduction of 50% in the uranium density in the same ones was shown to be adequate to solve the problem.


  • IPEN-DOC 24803

    ULRICH, J.C. ; GUILHEN, S.N.; COTRIM, M.E.B. ; PIRES, M.A.F. . Method development and validation for simultaneous determination of IEA-R1 reactor’s pool water uranium and silicon content by ICP OES. Journal of Physics: Conference Series, v. 975, n. 012012, p. 1-5, 2018. DOI: 10.1088/1742-6596/975/1/012012

    Abstract: IPEN’s research reactor, IEA-R1, an open pool type research reactor moderated and cooled by light water. High quality water is a key factor in preventing the corrosion of the spent fuel stored in the pool. Leaching of radionuclides from the corroded fuel cladding may be prevented by an efficient water treatment and purification system. However, as a safety management policy, IPEN has adopted a water chemistry control which periodically monitors the levels of uranium (U) and silicon (Si) in the pool’s reactor, since IEA-R1 employs U3Si2-Al dispersion fuel. An analytical method was developed and validated for the determination of uranium and silicon by ICP OES. This work describes the validation process, in a context of quality assurance, including the parameters selectivity, linearity, quantification limit, precision and recovery.


  • IPEN-DOC 24802

    TANGO, RUBENS N.; ARATA, ANELYSE ; BORGES, ALEXANDRE L.S.; COSTA, ANNA K.F.; PEREIRA, LUCIANO J.; KAMINAGAKURA, ESTELA. The role of new removable complete dentures in stimulated salivary flow and taste perception. Journal of Prosthodontics - Implant Esthetic and Reconstructive Dentistry, v. 27, n. 4, p. 335-339, 2018. DOI: 10.1111/jopr.12507

    Abstract: Purpose: To evaluate the effect of replacement of inadequate complete dentures on salivary flow and taste perception in geriatric patients. Materials and Methods: Thirty-three patients, 13 males and 20 females, with amean age of 64.4 years were submitted to stimulated and unstimulated salivary flow rate and salivary pH measurements, and sense of taste evaluation. Tests were performed 3 months before complete denture substitution and 3 weeks after denture insertion. Results: The mean for unstimulated saliva (USS) was 2.1 ml before and 2.7 ml after replacement (p = 0.003). The mean volume of stimulated saliva was 6.3 ml before and 8.2 ml after replacement (p = 0.004). The pH mean of USS was 7.8 ± 0.44 before and 8.02 ± 0.41 after replacement (p = 0.005). No statistically significant difference was determined in the sense of taste before and 3 weeks after complete denture replacement. Conclusions: The replacement of inadequate complete dentures increases saliva flow; however, it does not improve taste perception.


  • IPEN-DOC 24800

    SOUZA, F.M.; NANDENHA, J.; BATISTA, B.L.; OLIVEIRA, V.H.A.; PINHEIRO, V.S.; PARREIRA, L.S.; NETO, A.O. ; SANTOS, M.C.. PdxNby electrocatalysts for DEFC in alkaline medium: stability, selectivity and mechanism for EOR. International Journal of Hydrogen Energy, v. 43, n. 9, p. 4505-4516, 2018. DOI: 10.1016/j.ijhydene.2018.01.058

    Abstract: PdxNby/C binary electrocatalysts supported on Vulcan carbon XC72 were prepared by the sol-gel method. The materials are characterized by transmission electron microscopy, X-ray diffraction analysis, inductively coupled plasma–mass spectrometry and contact angle measurements. The electrocatalytic activity for ethanol electrooxidation reaction was studied by cyclic voltammetry, chronoamperometry, Tafel slope and accelerated durability testing. The direct ethanol performance and the products after the experiments were studied by Fourier transform infrared spectroscopy. Pd1Nb1/C (50:50 wt%) shows superior activity for ethanol oxidation compared to the other electrocatalysts prepared in this work. All electrocatalysts containing Nb show the highest current exchange density. The Tafel slope results suggest that the Nb modified the Pd-electrocatalyst to obtain a reaction path with high selectivity with only a single determining step with low production of the intermediates for the ethanol oxidation reaction. The best performance is obtained using Pd1Nb1/C 18.11 mW cm−2. The Pd1Nb1/C electrocatalyst displays the highest production of CO2 and the lowest production of acetaldehyde. Pd1Nb1/C shows the highest peak current density during 1000 cycles of the experiment and the lowest mass loss of Pd after the cycling test. We find that the Nb modifies the Pd electrocatalysts from the bifunctional mechanism and reduces the loss of Pd during the accelerated durability test.


  • IPEN-DOC 24799

    RIBEIRO, MARTHA S. ; GARGANO, RONALDO G.; SABINO, CAETANO P.; ANJOS, CAROLINA dos; POGLIANI, FABIO C.; SELLERA, FABIO P.. Clinical challenges of antimicrobial photodynamic therapy for bovine mastitis. Photodiagnosis and Photodynamic Therapy, v. 21, p. 327-327, 2018. DOI: 10.1016/j.pdpdt.2018.01.007

    Abstract: Sir, Antimicrobial photodynamic therapy (aPDT) is emerging as a new promising tool to treat local infections in Veterinary Medicine [1]. In 2016, our group was the pioneer to investigate its use to inactivate pathogens related to bovine mastitis [2]. In this regard, in a recent report published in this journal, Moreira et al. [3] explored the use of toluidine blue (TBO)-mediated aPDT to treat subclinical bovine mastitis. Remarkably, bovine mastitis still remains as the most economically relevant disease for dairy industry worldwide, resulting in substantial economic losses for milk producers due to extensive antibiotic use and product losses. In this sense, antibiotic misuse or overuse to treat bovine mastitis is worrisome because it can simultaneously lead to antibiotic residues in dairy products and increase multidrug-resistant foodborne pathogens. Unfavorably, there is still no consensus on the ideal approach for bovine mastitis treatment; therefore, aPDT represents a viable option to reduce the use of antibiotics in dairy farms. The preliminary results of Moreira et al. [3] are exciting and deserve discussion on some points. In this letter, we intend to highlight other relevant aspects to be addressed in order to consolidate the use of aPDT for management of bovine mastitis. The concentration of the photosensitizer (PS) diluted in the milk plays a pivotal role. In the study by Moreira et al. [3], the authors designed a clinical assay using a 2.5% TBO solution, which promoted a significant reduction of bacterial load. It is noteworthy that clinical mastitis represents a more complex challenge for aPDT than subclinical mastitis since the alterations in the milk composition could influence the PS absorption properties. Additionally, we believe that intermolecular interactions between PS and milk components should be considered to optimize clinical protocols because it could induce aggregation of phenothiazine dyes and leads to lower photodynamic inactivation efficiency [[4], [5]]. Another important point is in respect to the light diffusion within mammary parenchyma. Appropriated light delivery systems need to reach deeper mammary tissue since pathogens normally colonize the entire mammary gland [6]. Therefore, the use of diffuser fibers should be considered to deliver homogeneous light intensities inside the gland parenchyma. Hence, investigations regarding different light delivery systems could optimize clinical protocols and facilitate the establishment of aPDT into the dairy industry. Finally, we encourage the development of innovative strategies to improve selective PS delivery to pathogens using targeted molecular and nanoparticle systems. In summary, we hope that this letter motivates further studies to develop safe and effective protocols for bovine mastitis and promote aPDT applications in Veterinary Medicine.


  • IPEN-DOC 24798

    SILVEIRA, LUCAS M. da; PEREIRA, MARCO A.M.; NEVES, LUCIO P. ; PERINI, ANA P. ; BELINATO, WALMIR; CALDAS, LINDA V.E. ; SANTOS, WILLIAM S.. Exposure to 137Cs deposited in soil – A Monte Carlo study. Journal of Physics: Conference Series, v. 975, n. 012050, p. 1-5, 2018. DOI: 10.1088/1742-6596/975/1/012050

    Abstract: In the event of an environmental contamination with radioactive materials, one of the most dangerous materials is 137Cs. In order to evaluate the radiation doses involved in an environmental contamination of soil, with 137Cs, we carried out a computational dosimetric study. We determined the radiation conversion coefficients (CC) for effective (E) and equivalent (H T) doses, using a male and a female anthropomorphic phantoms. These phantoms were coupled with the MCNPX (2.7.0) Monte Carlo simulation software, for three different types of soil. The highest CC[H T] values were for the gonads and skin (male) and bone marrow and skin (female). We found no difference for the different types of soil.


  • IPEN-DOC 24797

    SILVA, P.S.M.; ESPOSITO, V.; MARANI, D.; FLORIO, D.Z. de; MACHADO, I.F.; FONSECA, F.C. . Thermochemical stability of zirconia-titanium nitride as mixed ionic-electronic composites. Ceramics International, v. 44, n. 7, p. 8440-8446, 2018. DOI: 10.1016/j.ceramint.2018.02.039

    Abstract: Dense zirconia (8% molar yttria-stabilized ZrO2)-titanium nitride (TiN) composites are fabricated to obtain mixed ionic-electronic conducting ceramic systems with high degree of electronic and thermal conductivity. The composites are consolidated by spark plasma sintering (SPS), starting from pure powders of the pristine phases mixed in different ratios (TiN = 25, 50, 75 wt%). A careful optimization of the SPS conditions allows producing highly dense samples with no reaction between the phases or degradation by oxidation, thus maintaining the chemical integrity of the two phases. For all the composites, high electrical conductivity is attained. Samples exhibit metallic behavior, showing an unexpected percolation of TiN in the YSZ matrix for volume fraction ≤ 25 wt% (27 vol%). Chemical degradation and electrical properties of the compounds were monitored under oxidative (air) and inert (Ar) atmosphere at high temperatures. The oxidation kinetics of the nitride phase was inhibited by the microstructure of the composite. The electrical properties of such composites were explored at high temperature to evaluate its application in electrochemical devices. As results, it is shown that electrical transport properties of the composite can be tuned by both the relative volume fraction of phases and controlled oxidative treatments. Adjusting such parameters different electric behaviors were observed ranging from predominant electronic conductors, to temperature-independent resistivity, and semiconducting.


  • IPEN-DOC 24796

    SILVA, R.A.; LEAL NETO, R.M. ; LEIVA, D.R.; ISHIKAWA, T.T.; KIMINAMI, C.S.; JORGE JUNIOR, A.M.; BOTTA, W.J.. Room temperature hydrogen absorption by Mg and Mg-TiFe nanocomposites processed by high-energy ball milling. International Journal of Hydrogen Energy, v. 43, n. 27, p. 12251-12259, 2018. DOI: 10.1016/j.ijhydene.2018.04.174

    Abstract: Mg - 40 wt % TiFe nanocomposite was prepared by high-energy ball milling, HEBM, aiming improved hydrogen absorption at room temperature (RT). Four processing routes were chosen to separately investigate the effects of TiFe addition, HEBM processing and dispersion of TiFe particles, being: Route 1 – mechanical mixture of Mg and TiFe powders; Route 2 – HEBM of Mg + TiFe at 400 rpm for 12 h; Route 3 – HEBM of pure Mg at 400 rpm for 12 h to be used as reference; and Route 4 – HEBM of Mg + TiFe at 600 rpm for 36 h. In this case, TiFe was previously milled with ethanol to improve its refinement level. It is shown that the synergetic effects of TiFe addition, HEBM processing and thermal activation – involving the creation of MgTiFe interfaces, the refinement and distribution of TiFe and also the presence of free Fe – lead to good hydrogenation kinetics at RT in MgTiFe nanocomposite. It is also shown for the first time that the milled pure Mg can absorb hydrogen at RT.


  • IPEN-DOC 24795

    SILVA, DIEGO S. da ; WETTER, NIKLAUS U. ; ROSSI, WAGNER de ; SAMAD, RICARDO E. ; KASSAB, LUCIANA R.P.. Femtosecond laser-written double line waveguides in germanate and tellurite glasses. In: NEUENSCHWANDER, BEAT (Ed.); GRIGOROPOULOS, COSTAS P. (Ed.); MAKIMURA, TETSUYA (Ed.); RACIUKAITIS, GEDIMINAS (Ed.) LASER APPLICATIONS IN MICROELECTRONIC AND OPTOELECTRONIC MANUFACTURING (LAMOM), 23th, January 27 - February 01, 2018, San Francisco, California, USA. Proceedings... Bellingham, WA, USA: Society of Photo-optical Instrumentation Engineers, 2018. p. 105191B-1 - 105191B-9. (SPIE Proceedings Series, 10519). DOI: 10.1117/12.2291223

    Abstract: The authors report the fabrication and characterization of passive waveguides in GeO2–PbO and TeO2–ZnO glasses written with a femtosecond laser delivering pulses with 3μJ, 30μJ and 80fs at 4kHz repetition rate. Permanent refractive index change at the focus of the laser beam was obtained and waveguides were formed by two closely spaced laser written lines, where the light guiding occurs between them. The refractive index change at 632 nm is around 10-4 . The value of the propagation losses was around 2.0 dB/cm. The output mode profiles indicate multimodal guiding behavior. Raman measurements show structural modification of the glassy network. The results show that these materials are potential candidates for passive waveguides applications as low-loss optical components.


  • IPEN-DOC 24794

    SILVA, N.F. ; SILVA, T.F.; CASTRO, M.C. ; LUZ, H.N. da; CALDAS, L.V.E. . Construction of the TH-GEM detector components for metrology of low energy ionizing radiation. Journal of Physics: Conference Series, v. 975, p. 1-4, 2018. DOI: 10.1088/1742-6596/975/1/012043

    Abstract: The Gas Electron Multiplier (GEM) detector was originally proposed as a position sensitive detector to determine trajectories of particles prevenient from high-energy collisions. In order to study the potential of TH-GEM type detectors in dosimetric applications for low energy X-rays, specifically for the mammography standard qualities, it was proposed to construct a prototype with characteristics suitable for such use. In this work the general, structural and material parameters applicable to the necessary conditions were defined, establishing the process of construction of the components of a prototype.


  • IPEN-DOC 24792

    SENNA, ANDRE M. de; VIEIRA, MARTHA M.F. ; MACHADO-DE-SENA, ROSA M.; BERTOLIN, APARECIDO O.; NUNEZ, SILVIA C.; RIBEIRO, MARTHA S. . Photodynamic inactivation of Candida ssp. on denture stomatitis. A clinical trial involving palatal mucosa and prosthesis disinfection. Photodiagnosis and Photodynamic Therapy, v. 22, p. 212-216, 2018. DOI: 10.1016/j.pdpdt.2018.04.008

    Abstract: Denture stomatitis (DS) is the most common oral fungal infection in denture wearers. Photodynamic inactivation (PDI) has been showing to be an effective technique in vivo against fungi, including fungal infections in the oral cavity. The disinfection of both oral mucosa and denture may represent a real advantage in terms of fungus control. This clinical study was designed to explore methylene blue (MB)-mediated PDI on oral mucosa and prosthesis of patients with DS. Subjects with DS were divided into two groups. One group received treatment based on the use of oral miconazole gel 2% (MIC). The other group received treatment by PDI using MB at 450 μg/mL and a diode laser (λ = 660 nm) with 100 mW and fluence of 28 J/cm2. Clinical outcome was evaluated regarding the degree of oral mucosa erythema and microbiological reduction of Candida spp. located in both palatal mucosa and prosthesis. Our results showed that PDI was significantly more effective than MIC in ameliorating inflammation after 15 days. Following 30 days, no statistically significant differences were observed between groups. Regarding the fungal burden, although the MIC group has presented more pronounced inactivation than PDI for both mucosa and prosthesis, no statistically significant differences were detected between them. This clinical study suggests that PDI can reduce fungal load and decrease the inflammation degree in patients with Candida-associated denture stomatitis.


  • IPEN-DOC 24791

    SCURO, N.L.; SANTOS, P.G.; UMBEHAUN, P.E. ; ANDRADE, D.A. ; ANGELO, E.; ANGELO, G.. Transient cfd analysis of the flow inversion of the nuclear research reactor IEA-R1. In: EUROPEAN RESEARCH REACTOR CONFERENCE, March 11-15, 2018, Munich, Germany. Proceedings... Brussels, Belgium: European Nuclear Society, 2018.

    Abstract: The IEA-R1 research reactor works with a downflow direction, but after pumps shutdown during a LOFA test, the reactor shutdown. The heat decay will be removed by natural convection, which is an upward flow, originating flow inversion. Using the Instrumented Fuel Element designed at the Institute for Energy and Nuclear Research (IPEN), the loss of flow accident (LOFA) was analyzed along instrumented fuel plates. The preliminary results showed temperature peaks during inversion, which is as much representative as in nominal operation at 3.5MW. Therefore, these experimental data lead a construction and validation of a transient three-dimensional numerical analysis for a single fuel channel using the ANSYS-CFX® commercial code. The numerical results show improvement in obtaining more properties, e.g., wall heat transfer coefficient, which is usually obtained through empirical correlations.


  • IPEN-DOC 24790

    SCURO, N.L.; ANGELO, E.; ANGELO, G. ; ANDRADE, D.A. . A CFD analysis of the flow dynamics of a directly-operated safety relief valve. Nuclear Engineering and Design, v. 328, p. 321-332, 2018. DOI: 10.1016/j.nucengdes.2018.01.024

    Abstract: A three-dimensional numerical study on steady state was designed for a safety relief valve using several openings and inlet pressures. The ANSYS-CFX (R) commercial code was used as a CFD tool to obtain several properties using dry saturated steam revised by IAPWS-IF97. Mass flow and discharge coefficient calculated from simulations are compared to the ASME 2011a Section 1 standard. The model presented constant behavior for opening lifts smaller than 12mm and is very reasonable when compared to the standard (ASME). In addition, the conventional procedure to design normal disc force assumes that all the fluid mechanical energy was converted into work; however, the CFD simulations showed that average normal disc force is about 19% lower than theoretical ASME force, which could prevent the valve oversizing. A numerical validation was conducted for a transonic air flow through a converging-diverging diffuser geometry to verify the solver's ability to capture the position and intensity of a shockwave: the results showed good agreement with the benchmark experiments.


  • IPEN-DOC 24789

    SAVOINE, MARCIA M. ; MENEZES, MARIO O. de ; ANDRADE, DELVONEI A. de . Proposal of a methodology for the assessment of security levels of IoT wireless sensor networks in nuclear environments. World Journal of Nuclear Science and Technology, v. 8, n. 2, p. 78-85, 2018. DOI: 10.4236/wjnst.2018.82008

    Abstract: The use of Wireless Sensor Networks (WSN) associated with the reality of an Internet of Things (IoT) scenario in nuclear environments is a growing security concern. In this context, standards are intensified to preserve the physical integrity of these facilities considered to be highly critical due to the size of the impacts of safety accidents. This paper presents a proposal to build a methodology to evaluate the security levels of WSNs with IoT devices when used in nuclear areas. The proposal is initially based on related work to establish a more concrete initial framework and is structured in consistent steps from previous scientific studies.


  • IPEN-DOC 24787

    SANTOS, S.C. ; RODRIGUES JUNIOR, O. ; CAMPOS, L.L. . EPR dosimetry of yttria micro rods. Journal of Alloys and Compounds, v. 742, p. 263-270, 2018. DOI: 10.1016/j.jallcom.2018.01.315

    Abstract: The use of rare earths (RE) as dopant of materials has led the development of advanced materials for many applications such as optical tracers, special alloys, semiconductors, as well as radiation dosimeters. The development of new dosimetric materials based on REs is a great challenge in innovation of materials. Yttria (Y2O3) presents luminescent proprieties and is a promising material for radiation dosimetry. The present paper aims to evaluate paramagnetic defects of Y2O3 rods obtained via bio-prototyping by using Electron Paramagnetic Resonance (EPR) technique at room temperature. Ceramic rods were irradiated with gamma doses from 0.001 to 150 kGy and evaluated by EPR at room temperature with X-band EPR. According to EPR results, as sintered samples exhibited an EPR signal with principal g tensor of 2.020 and maximum line width around 2.3 mT, which is ascribed to interstitial oxygen ion. Dose response behaviour exhibited two distinct dose ranges, one is from 1 to 100Gy and the second is from 0.1 to 70 kGy. Thermal annealing approaches reveal that defect centres of yttria decay significantly at high temperature. These innovative results make Y2O3 a promising material for radiation dosimetry.


  • IPEN-DOC 24786

    SANTOS, ROSA C.L.; LIMA, ALVARO S.; CAVALCANTI, ELIANE B.; MELO, CLAUDIA M. de; MARQUES, MARIA N. . Aplicação de índices para avaliação da qualidade da água da Bacia Costeira do Sapucaia em Sergipe / Application of indexes to assess the water quality of coastal basin of the Sapucaia in Sergipe. Engenharia Sanitaria e Ambiental, v. 23, n. 1, p. 33-46, 2018. DOI: 10.1590/S1413-41522017159832

    Abstract: A redução da disponibilidade qualiquantitativa da água no mundo está diretamente relacionada às formas de uso e ocupação do solo, aos processos produtivos da agricultura e da pecuária, ao processo de urbanização e à geração de efluentes domésticos e industriais. Por isso, é importante a realização de diagnósticos de bacias hidrográficas, sobre o uso e a ocupação de seu solo e sobre a qualidade da água como ferramenta para a gestão hídrica. Este estudo teve como objetivo caracterizar e monitorar a qualidade da água da Bacia Costeira do Sapucaia, Sergipe. As coletas foram realizadas em oito pontos, com periodicidade trimestral, de agosto de 2014 a setembro de 2015. Na avaliação da qualidade da água foram utilizados: o Índice de Qualidade da Água (IQA) e o Índice de Estado Trófico (IET). As análises das amostras foram realizadas de acordo com os procedimentos estabelecidos no Standard Methods, sendo analisados os seguintes parâmetros: coliformes totais e termotolerantes, turbidez, pH, oxigênio dissolvido, sólidos totais, fósforo total, nitrogênio total, temperatura, condutividade, demanda bioquímica de oxigênio e clorofila. Os resultados do IQA classificam os corpos d’água em aceitável (2,5%), bom (92,5%) e ótimo (5,0%). Os resultados do IET classificaram as amostras como: ultraoligotrófico (67,5%), oligotrófico (20,0%), mesotrófico (2,5%), eutrófico (7,5%) e supereutrófico (2,5%). Os resultados obtidos permitem afirmar que os rios Aningas, Sapucaia e a Lagoa Redonda apresentam baixo grau de degradação, com menor conservação do ponto amostral localizado no Rio Sapucaia, dentro da Reserva Santa Isabel, por ser uma área bastante visitada nos finais de semana e feriados.


  • IPEN-DOC 24785

    SALLES, FERNANDA J.; SATO, ANA P.S.; LUZ, MACIEL S.; FAVARO, DEBORAH I.T. ; FERREIRA, FRANCISCO J.; PAGANINI, WANDERLEY da S.; OLYMPIO, KELLY P.K.. The environmental impact of informal and home productive arrangement in the jewelry and fashion jewelry chain on sanitary sewer system. Environmental Science and Pollution Research, v. 25, n. 11, p. 10701-10713, 2018. DOI: 10.1007/s11356-018-1357-z

    Abstract: The outsourcing informal home practices adopted in jewelry and fashion jewelry chain can cause toxic substance elimination in the effluents and raise a concern for its environmental impact. This study evaluates if this informal work alters the concentration of potentially toxic elements (PTEs: As, Cd, Cr total and Cr-VI, Cu, Hg, Ni, Pb, Sn, and Zn) in the sewage network. The sanitary sewage samples (n = 540) were collected in 15 manholes during two campaigns in three different areas of Limeira-SP, Brazil (industrial area, with informal work and without known industrial/informal activity). The sewage sludge (n = 12), raw (n = 12), and treated sewage (n = 12) were collected in two wastewater treatment plants (WWT: AS and TATU) operating with different treatment process. The PTE determination was performed by ICP-OES, direct mercury analysis, and UV-Vis spectroscopy. Cr-VI, Cu, Ni, and Zn were the only elements above the quantification limit. Four samples exceeded Cu or Zn values permitted to be discharged into sewage system; however, the concentration average was lower than that established by Brazilian legislation. A difference was found between values above and below the 75th percentile for campaign and total organic carbon values (p < 0.015). The AS-treated sewage presented low concentrations of Cu (p < 0.05), Zn (p = 0.02), and Ni (p = 0.01) compared to treated sewage from TATU. In the sludge samples, the Cu means exceeded the limits of the Brazilian legislation (1500 mg kg(-1)) and the Zn results were very close to the limits (2800 mg kg(-1)). The heterogeneity of the results can indicate the sporadic nature of the PTE's sanitary disposal. PTEs used in jewelry and fashion jewelry chain may precipitate on the sludge, where presented high concentrations of Cu and Zn which require controlled destination.


  • IPEN-DOC 24784

    SABUNDJIAN, GAIANE ; CONTI, THADEU das N. ; CABRAL, EDUARDO L.L. . Hierarchical expansion method in the solution of the Navier-Stokes Equations for incompressible fluids in laminar two-dimensional flow. Energy and Power Engineering, v. 10, n. 1, p. 1-9, 2018. DOI: 10.4236/epe.2018.101001

    Abstract: Among the several methods used to solve the Navier-Stokes equations Hierarchical Expansion Method has demonstrated satisfactory results. This work aimed to apply the expansion of the variables in hierarchical functions for the solution of the Navier-Stokes equations for incompressible fluids in two dimensions in laminar flow. This method is based on the finite element method. The expansion functions in this study were based on Legendre polynomials, adjusted in the rectangular elements in such a way that corner, side and area functions were defined. The order of the expansion functions associated with the sides and with the area of the elements is adjusted to the necessary or desired degree. This method is denominated by Hierarchical Expansion Method. In order to validate the proposed numeric method three well-known problems of the literature in two dimensions were analyzed; however, for this paper only one problem was presented. The results demonstrated that method was able to provide precise results. From the results obtained in this paper it is possible to conclude that the hierarchical expansion method can be effective for the solution of fluid dynamic problems that involve incompressible fluids.


  • IPEN-DOC 24783

    ROVANI, SUZIMARA ; SANTOS, JONNATAN J.; CORIO, PAOLA; FUNGARO, DENISE A. . Highly pure silica nanoparticles with high adsorption capacity obtained from sugarcane waste ash. ACS Omega, v. 3, n. 3, p. 2618-2627, 2018. DOI: 10.1021/acsomega.8b00092

    Abstract: Silica nanoparticles (SiO2NPs) from renewable sources can be used in very different materials, such as paints, membranes for fuel cells, Li-ion batteries, adsorbents, catalysts, and so on. Brazil is the world’s largest producer of sugarcane and generates huge amounts of sugarcane waste ash (SWA), which is a Si-rich source. This study investigates a method to produce highly pure SiO2NPs from SWA. The SiO2NPs were characterized by inductively coupled plasma optical emission spectroscopy, scanning and transmission electron microscopy (TEM), X-ray diffraction analyses, specific surface area and pore distribution, UV and Fourier transform infrared spectroscopy, and thermogravimetric analyses and applied as an adsorbent material in the removal of acid orange 8 (AO8) dye from aqueous solution. The SiO2 content was 88.68 and 99.08 wt % for SWA and SiO2NPs, respectively. TEM images of SWA and SiO2NPs exhibit drastic alterations of the material size ranging from several micrometers to less than 20 nm. The SiO2NPs showed a specific surface area of 131 m2 g–1 and adsorption capacity of around 230 mg g–1 for acid orange 8 dye. Furthermore, the recycling of the SiO2NPs adsorbent after AO8 adsorption was very satisfactory, with reuse for up to five cycles being possible. The results indicate that it was possible to obtain highly pure silica in a nanosize from the waste material and produce an adsorbent with high adsorption capacity and the possibility of reuse.


  • IPEN-DOC 24782

    RONQUIM, FLAVIA M.; COTRIM, MARYCEL E.B. ; GUILHEN, SABINE N. ; BERNARDO, ANDRE; SECKLER, MARCELO M.. Improved barium removal and supersaturation depletion in wastewater by precipitation with excess sulfate. Journal of Water Process Engineering, v. 23, p. 265-276, 2018. DOI: 10.1016/j.jwpe.2018.04.007

    Abstract: Barium ions found in wastewaters cause incrustation on membrane separation equipment used in desalination systems. In this study barium removal by precipitation is addressed, considering excess sulfate addition as a means of reducing barium concentration in solution and depleting BaSO4 supersaturation. Precipitation is conducted with synthetic wastewater in semicontinuous mode. For low excess sulfate, an induction time of a few hours is observed. As the excess sulfate is increased and/or as barium sulfate seeds are added, precipitation proceeds within a few minutes. Besides, the excess sulfate improves barium ion removal due to the common-ion effect. Residual supersaturation ratios were found to lie within the range of 1.1–3. These values were associated with a fourth order dependency of the molecular growth rate with the supersaturation ratio. Calcium carbonate and calcium sulfate dihydrate were found to be ineffective heterogeneous seeds to barium sulfate precipitation. Calcium ions were found to inhibit BaSO4 precipitation, blocking the process at a high residual supersaturation ratio of 4–5. For a sufficiently large initial supersaturation, the solution approaches equilibrium after 180 min.


  • IPEN-DOC 24781

    RIBEIRO, MARTHA S. ; MELO, LUCIANA S.A. de; FAROOQ, SAJID; BAPTISTA, ALESSANDRA ; KATO, ILKA T.; NUNEZ, SILVIA C.; ARAUJO, RENATO E. de. Photodynamic inactivation assisted by localized surface plasmon resonance of silver nanoparticles: in vitro evaluation on Escherichia coli and Streptococcus mutans. Photodiagnosis and Photodynamic Therapy, v. 22, p. 191-196, 2018. DOI: 10.1016/j.pdpdt.2018.04.007

    Abstract: Localized surface plasmon resonance (LSPR) of gold nanoparticles has been reported to increase the antimicrobial effect of the photodynamic therapy. Although silver nanoparticles (AgNPs) are an efficient growth inhibitor of microorganisms, no studies exploring LSPR of AgNPs to enhance the photodynamic inactivation (PDI) have been related. In this work, we described the LSPR phenomenon of AgNP sand investigated its interaction with riboflavin, a natural photosensitizer. We evaluated the use of AgNPs coated with pectin (p-AgNP) in riboflavin (Rb)-mediated PDI of Escherichia colt (Gram- bacteria) and Streptococcus mutans (Gram + bacteria) using a blue light-emitting diode (lambda = 455 +/- 20 nm) of optical power 200 mW. Irradiance was 90 mW/cm(2) and radiant exposure varied according to the time exposure. Uptake of Rb and p-AgNP by the cells was evaluated by measuring the supernatant absorption spectra of the samples. We observed that LSPR of p-AgNPs was able to enhance the riboflavin photodynamic action on S. mutans but not on E. colt, probably due to the lower uptake of Rb by E. colt. Taken together, our results provide insights to explore the use of the LPRS promoted by silver nanostructures to optimize antimicrobial PDI protocols.


  • IPEN-DOC 24779

    PRETTO, LUCAS R. de ; SAMAD, RICARDO E. ; ROSSI, WAGNER de ; FREITAS, ANDERSON Z. de . Optical coherence tomography characterization of femtosecond laser manufactured microfluidic circuits. In: GRAY, BONNIE L. (Ed.); BECKER, HOLGER (Ed.) MICROFLUIDICS, BIOMEMS, AND MEDICAL MICROSYSTEMS, 16th, January 27 - February 01, 2018, San Francisco, California, USA. Proceedings... Bellingham, WA, USA: Society of Photo-optical Instrumentation Engineers, 2018. p. 104911A-1 - 104911A-12. (SPIE Proceedings Series, 10491). DOI: 10.1117/12.2289937

    Abstract: Dimensional characterization of microfluidic circuits were performed using three-dimensional models constructed from OCT images of such circuits. Were fabricated microchannels on the same BK7 glass plate, under different laser ablation conditions and substrate displacement velocity in relation to laser beam. Were used the following combination of energy, from 30 μJ to 60 μJ and velocity from 588 mm/min to 1176 mm/min, at 1 kHz laser repetition rate and 40 fs of pulse duration (FWHM). For OCT imaging we used an OCP930SR (Thorlabs System Inc) with 930 nm central wavelength, 6 μm of lateral and axial resolution, and image of 500 x 512 pixel corresponding to 2.0 mm x 1.6 mm of lateral and axial scans respectively at 8 frames per second. We also characterized devices like, micropumps, microvalves and microreactors. It was possible register the micropumps and valves in action in real time. Using the OCT images analyses was possible to select the best combination of laser pulse energy and substrate velocity. All the devices were made in raster protocol, where laser beam pass through the same path in a controlled number of times, and with each iteration more material is removed and deeper the channels remain. We found a deformation at the edge of fabricated structures, due to velocity reduction of substrate in relation to laser beam, which causes more laser pulses superposition in these regions, and more material is ablated. The technique was thus evaluated as a potential tool to aid in the inspection of microchannels.


  • IPEN-DOC 24813

    JAROSZEWSKI, CASSIANE da R. . Os governos estaduais e a política pública de inovação tecnológica : análise a partir do modelo teórico de Hélice Tríplice / State level government and innovation policy in Brazil . 2018. Tese (Doutorado) - Fundação Getúlio Vargas - Escola de Administração de Empresas de São Paulo, São Paulo. 213 p. Orientador: Regina Silvia Viotto Monteiro Pacheco.

    Abstract: Esta tese de doutoramento se propõe a discutir qual o papel do governo na formulação e implementação da política pública de inovação tecnológica e os novos formatos organizacionais criados pela interação entre universidades, empresas e governo. A partir do referencial teórico da Hélice Tríplice é possível conceber a inovação tecnológica enquanto resultado da interação entre as hélices universidade, empresa e governo. Dessa interação resultam alterações no funcionamento de cada hélice e a criação de organizações híbridas no ponto de interseção trilateral. Foram estabelecidas três categorias empíricas para compreender o papel do governo na política de inovação: 1. Capacidade do governo de constituir-se como um Espaço de Consenso, 2. Análise dos programas estaduais para interação universidade-empresa e 3. Atuação de três tipos de organizações híbridas: Núcleos de Inovação Tecnológica, incubadoras e parques tecnológicos. A pesquisa classifica-se como qualitativa, descritiva, exploratória e de estudo de caso, com as técnicas de pesquisa bibliográfica, documental, observações e entrevistas. As políticas de inovação de três estados foram analisadas em profundidade: Amazonas, Pernambuco e Santa Catarina. O resultado indica que os governos avançaram na inclusão da temática da inovação nas agendas estaduais enquanto tema central para o desenvolvimento econômico e social, mas que esse avanço não se reverteu em maior envolvimento dos órgãos públicos sendo uma agenda quase totalmente conduzida pelas Secretarias Estaduais de Ciência e Tecnologia e Fundações de Amparo à Pesquisa. O governo age como Espaço de Consenso, tendo sua legitimidade para coordenar e implementar ações reconhecida pelos outros stakeholders afetos à temática da inovação, contudo falta clareza quanto a quais são os objetivos e setores prioritários da política. Em relação aos programas de fomento à inovação, os governos adotam estratégias de estímulo ao empreendedorismo como forma de contornar a dificuldade de interação com as empresas existentes. Já os programas para promoção de interação entre universidades e empresas esbarram em barreiras culturais e institucionais que o governo não consegue romper sem mudança de mentalidade dos representantes das outras hélices acerca da relevância dessas parcerias.


  • IPEN-DOC 24778

    PORFIRIO, T.C. ; MUCCILLO, E.N.S. . Thermal and electrical properties of CaCu3Ti4O12 synthesized by soft chemistry route. Journal of Thermal Analysis and Calorimetry, v. 133, n. 2, p. 851–857, 2018. DOI: 10.1007/s10973-018-7184-0

    Abstract: Calcium copper titanate powders were synthesized by a soft chemistry route, aiming to establish a cost-effective solution method to obtain sintered ceramics with giant electric permittivity (ε′) and low dissipation factor (tanδ). Powders and sintered pellets were characterized by several techniques. The thermal decomposition behavior of the porous foam evidences that a hydroxycitrate was formed below 200 °C. Single cubic perovskite-type phase was obtained after calcination of the precursor powder at 700 °C for 5 h. Negligible mass loss occurs above 400 °C. During heating the precursor material, CuO is the first crystallized phase. A giant ε′ and low tanδ are obtained after sintering. The extension of the thermal window of ε′ is wider than those of powders prepared by other methods.


  • IPEN-DOC 24777

    PEREIRA, DAISA L. ; FREITAS, ANDERSON Z. ; BACHMANN, LUCIANO; BENETTI, CAROLINA; ZEZELL, DENISE M. ; ANA, PATRICIA A.. Variation on molecular structure, crystallinity, and optical properties of dentin due to Nd:YAG laser and fluoride aimed at tooth erosion prevention. International Journal of Molecular Sciences, v. 19, n. 2, 2018. DOI: 10.3390/ijms19020433

    Abstract: This in vitro study evaluated the compositional, crystalline, and morphological effects promoted by Nd:YAG laser on root dentin, and verified the effects of laser and topical acidulated phosphate fluoride application (APF-gel) on dentin erosion. 180 bovine dentin slabs were randomized into 4 groups (n = 45): G1–untreated, G2–APF-gel (1.23% F−, 4 min), G3–Nd:YAG (1064 nm, 84.9 J/cm2, 10 Hz), and G4–APF-gel application followed by Nd:YAG laser irradiation. The compositional, crystalline, and morphological effects promoted by treatments were investigated on five samples of each experimental group. The other samples were submitted to a 5-day, 10-day, or 15-day erosive and abrasive demineralization and remineralization cycling in order to create erosion lesions. The area and depth of lesions, as well as the optical attenuation coefficient, were assessed, and all data were statistically analysed (p < 0.05). Nd:YAG laser promoted the reduction of carbonate, the formation of tetracalcium phosphate, as well as the melting and recrystallization of the dentin surface. Laser significantly decreased the area and depth of erosion lesions and altered the optical attenuation coefficient when compared to untreated and APF-gel groups, but the association of APF-gel and laser did not promote an additional effect. Nd:YAG laser irradiation can be a promissory treatment to prevent dentin erosion and the abrasion process.


  • IPEN-DOC 24776

    PEREIRA, LUIZ A.T. ; ROSSI, JESUALDO L. . The recycling through melting Zircaloy machining chips, preliminary results. Brazilian Journal of Radiation Sciences, v. 6, n. 2, p. 01-11, 2018. DOI: 10.15392/bjrs.v6i2.425

    Abstract: PWR (Pressurized Water Reactor) reactors employ as nuclear fuel UO2 pellets packed in zirconium alloy tubes, called cladding. In the manufacture of the tubes, machining chips are generated which can not be discarded, since the recycling of this material is strategic in terms of nuclear technology, legislation, economics and the environment. These nuclear alloys are very expensive and are not produced in Brazil and are imported for the manufacture of nuclear fuel. In this work, we will discuss methods not yet studied to recycle Zircaloy chips using electron beam furnaces in order to obtain ingots. In addition, it is intended to carry out the melting of new Zircaloy alloys, from the fusion of zirconium sponge produced in IPEN and imported and Zircaloy bars. The mechanical properties and the present phases of the material should be determined, as well as, the characterization of the microstructures by optical microscopy. This work, therefore, aims at the creation of a new line of research where methods will be approached to recycle the chips and to reduce in 30 times by means of fusion the enormous volume of material stored in the form of machining chips, being able to do others components for nuclear or chemical industry use, as well as conducting basic development research.


  • IPEN-DOC 24775

    PEREIRA, JULIAN M. de S. ; CIOTTI, LIGIA; VAZ, JORGE M. ; SPINACE, ESTEVAM V. . Preparation of Au/TiO2 catalyst by a liquid-phase reduction method for preferential oxidation of carbon monoxide in a hydrogen rich-stream (CO-PROX reaction). Materials Research - Ibero-American Journal of Materials, v. 21, n. 2, 2018. DOI: 10.1590/1980-5373-MR-2017-0756

    Abstract: Au nanoparticles supported on TiO2 were prepared by a liquid-phase reduction method using HAuC1(4) 3H(2)O as the Au precursor, TiO2 as the support, a solution of ethylene glycol/water as solvent and reducing agent and sodium citrate as reducing agent and stabilizer. The Au/TiO2 catalysts were prepared usmg different routes and characterized by Energy-dispersive X-ray spectroscopy, X-ray diffraction and Transmission Electron Microscopy and tested for preferential oxidation of carbon monoxide in hydrogen-rich stream (CO-PROX reaction). The way that the Au precursor, the TiO2 support and the sodium citrate is added to the ethylene glycol/water solution strongly influences the Au nanoparticle sizes and the catalytic activity of the obtained materials.


  • IPEN-DOC 24774

    PEREIRA, MARCO A.S. ; PUGLIESI, REYNALDO . Penetration of the consolidant Paraloid (R) B-72 in Macuxi indigenous ceramic vessels investigated by neutron tomography. Nuclear Instruments & Methods in Physics Research, A - Accelerators Spectrometers Detectors and Associated Equipment, v. 889, p. 118-121, 2018. DOI: 10.1016/j.nima.2018.02.034

    Abstract: The neutron tomography technique was applied in studying the penetration of the consolidant Paraloid (R) B-72 in contemporary indigenous ceramic vessels. The study was carried out for two distinct and controlled air humidity conditions, 40% and 90%, in which the vessels were exposed, before the consolidant application. The obtained images have proved that the penetration of Paraloid (R) B-72 in the ceramic does not depend on the humidity condition in which it was applied, moreover allowed a macro-visualization of the consolidant penetration in the ceramic vessel. As the vessels used in the present work were manufactured by an indigenous artisan, Macuxi, according to the same procedures and raw materials used by the ancient artisans, the results obtained can be used as a guide to assist experts, both in the study of archeological objects of Macuxi origin, as well as other objects that had been made by other tribes that lived in the same Amazon region, in Brazil.


  • IPEN-DOC 24773

    PEREIRA, MARIA da C.C. ; MADI FILHO, TUFIC ; BERRETTA, JOSE R. ; MESQUITA, CARLOS H. de . Characteristics of the CsI:Tl scintillator crystal for X-Ray imaging applications. Materials Sciences and Applications, v. 9, n. 2, p. 268-280, 2018. DOI: 10.4236/msa.2018.92018

    Abstract: Scintillators are high-density luminescent materials that convert X-rays to visible light. Thallium doped cesium iodide (CsI:Tl) scintillation materials are widely used as converters for X-rays into visible light, with very high conversion efficiency of 64.000 optical photons/MeV. CsI:Tl crystals are commercially available, but, the possibility of developing these crystals into different geometric shapes, meeting the need for coupling the photosensor and reducing cost, makes this material very attractive for scientific research. The objective of this work was to study the feasibility of using radiation sensors, scintillators type, developed for use in imaging systems for X-rays. In this paper, the CsI:Tl scintillator crystal with nominal concentration of the 10−3 M was grown by the vertical Bridgman technique. The imaging performance of CsI:Tl scintillator was studied as a function of the design type and thickness, since it interferes with the light scattering and, hence, the detection efficiency plus final image resolution. The result of the diffraction X-ray analysis in the grown crystals was consistent with the pattern of a face-centered cubic (fcc) crystal structure. Slices 25 × 2 × 3 mm3 (length, thickness, height) of the crystal and mini crystals of 1 × 2 × 3 mm3 (length, thickness, height) were used for comparison in the imaging systems for X-rays. With these crystals scintillators, images of undesirable elements, such as metals in food packaging, were obtained. One-dimensional array of photodiodes and the photosensor CCD (Coupled Charge Device) component were used. In order to determine the ideal thickness of the slices of the scintillator crystal CsI:Tl, Monte Carlo method was used.


  • IPEN-DOC 24772

    PACHECO, RAFAEL R. ; ANDRADE, DELVONEI A. de . Technological perspectives for propulsion on nuclear attack submarines. World Journal of Nuclear Science and Technology, v. 8, n. 1, p. 1-10, 2018. DOI: 10.4236/wjnst.2018.81001

    Abstract: This work aims to present the historical context in which the current understanding of the phenomenon of the direct contact condensation started to call the scientific society attention. The development of nuclear power plants Light Water Reactors demanded a safe way to collect and treat the water used to cool the reactor. Some characteristics of this water in a high energetic thermodynamic state made it unsuitable to be directly discharged in the atmosphere. Small room relieves tanks were developed to contain this discharge. These tanks were partially fulfilled with water, and the vapor injection created a vapor plume. In the interface of liquid and vapor, the thermal exchange would be increased by the characteristic turbulence of this region.


  • IPEN-DOC 24771

    OTTONI, C.A.; RAMOS, C.E.D.; SOUZA, R.F.B. de; SILVA, S.G. da ; SPINACE, E.V. ; NETO, A.O. . Glycerol and ethanol oxidation in alkaline medium using PtCu/C electrocatalysts. International Journal of Electrochemical Science, v. 13, n. 2, p. 1893-1904, 2018. DOI: 10.20964/2018.02.58

    Abstract: The performance of platinum-copper electrocatalysts synthesized in different ratios (100:0, 90:10, 70:30, 50:50, and 0:100), using a borohydride reduction method for electrochemical oxidation of different fuels, was evaluated in an alkaline direct alcohol fuel cell. X-ray diffraction of Pt/C and PtCu/C showed a face-centered cubic structure (fcc) of the platinum and its alloys. Transmission electron microscopy analysis allowed us to see a good dispersion of metallic particles with some regions with clusters of nanoparticles, for all the synthesised materials in the presence of copper. Cyclic voltammetry and chronoamperometry tests demonstrated that the PtCu/C (50:50) and PtCu/C (70:30) electrocatalysts exhibited the highest activity and stability for the glycerol and ethanol oxidation, respectively. The tests made in fuel cells, directly fed with glycerol and ethanol, presented the PtCu/C (90:10) electrocatalyst as the most effective on the oxidation reaction of the fuels when compared with Pt/C and Cu/C.


  • IPEN-DOC 24770

    ORTIZ, NILCE ; SILVA, ANDRE; LIMA, GISELLE N.S. ; HYPPOLITO, FERNANDA P. . Using solar-TiO2 and biocarbon to decompose and adsorb amoxicillin from polluted waters. International Journal of Chemistry, v. 10, n. 1, p. 131-136, 2018. DOI: 10.5539/ijc.v10n1p131

    Abstract: Surface water discharge of domestic sewage poses a treat mostly due to antibiotics content as amoxicillin. Its environmental presence provides the bacterial resistance enhancement and disturbance in aquatic life. The biocarbon is an organic carbon compound obtained by biomass pyrolisis at 300oC to 750oC under low oxygen environment. It is an effective adsorbent derived from agricultural and industrial solid biomass also frequently used to remove various pollutants, including dyes, pesticides, organic compounds and heavy metals from aqueous solutions. The importance of this natural material rises as low cost abundant and renewable alternative to activated carbon used on wastewater treatment application. Several technologies are employed to modify crude precursors on biocarbon preparation including chemical, physical and biological treatments with the addition of functional groups. The raw biomass material also provides some radicals and humic acids with promising water adsorbent results. The integrated process of the efficient Solar-TiO2photodecomposition followed by biocarbon adsorption resulted on 94% of amoxicillin removal percentage and avoids the toxic treatment sludge production.


  • IPEN-DOC 24769

    ORTEGA, ANDRESSA dos S.B.; MARANHO, LUCIANE A.; NOBRE, CAIO R.; MORENO, BEATRIZ B.; GUIMARAES, RAFAEL S.; LEBRE, DANIEL T. ; ABESSA, DENIS M. de S.; RIBEIRO, DANIEL A.; PEREIRA, CAMILO D.S.. Detoxification, oxidative stress, and cytogenotoxicity of crack cocaine in the brown mussel Perna perna. Environmental Science and Pollution Research, p. 1-10, 2018. DOI: 10.1007/s11356-018-1600-7

    Abstract: The presence of cocaine and its metabolites and by-products has been identified in different aquatic matrices, making crack cocaine the target of recent studies. The aim of this study was to evaluate the sublethal effects of crack on the brown mussel Perna perna. Mussels were exposed to three concentrations of crack cocaine (0.5, 5.0, and 50.0 μg L−1) for 168 h. Gills, digestive glands, and hemolymph were extracted and analyzed after three different exposure times using a suite of biomarkers (EROD, DBF, GST, GPX, LPO, DNA damage, ChE, and lysosomal membrane stability [LMS]). After 48 and 96 h of exposure, EROD, DBF, GST, GPX activities and DNA strand breaks in the gills increased significantly after 48 and 96 h of exposure. Alterations in LMS were also observed in the mussels exposed to all crack concentrations after 96 and 168 h. Our results demonstrated that crack cocaine is metabolized by CYP-like and GST activities in the gills. GPX was not able to prevent primary genetic damage, and cytotoxic effects in the hemocytes were also observed in a dose- and time-dependent response. Our study shows that the introduction of illicit drugs into coastal ecosystems must be considered a threat to marine organisms.


  • IPEN-DOC 24768

    OLIVEIRA, ERICA A. de ; FAINTUCH, BLUMA L. ; SEO, DANIELE ; BARBEZAN, ANGELICA B. ; FUNARI, ANA ; TARGINO, ROSELAINE C.; MORO, ANA M.. Radiolabeled GX1 peptide for tumor angiogenesis imaging. Applied Biochemistry and Biotechnology, p. 1-12, 2018. DOI: 10.1007/s12010-018-2700-z

    Abstract: Early and accurate detection of primary or metastatic tumors is of great value in staging, treatment management, and prognosis. Tumor angiogenesis plays an essential role in the growth, invasion, and metastatic spread of solid cancers, and so, is a promising approach for tumor imaging. The GX1 (CGNSNPKSC) peptide was identified by phage display library and has been investigated as a marker for human cancers. This study aims to evaluate the 99mTc-HYNIC-PEG4-c (GX1) as a biomarker for tumor imaging. Our results showed that GX1 specifically binds to tumor cells in vitro. SKMEL28 and MDA-MB231 cells achieved total binding peak at 60 min of incubation. For B16F10 and MKN45 cells, the total and specific binding were similar during all time points, while A549 cell line showed rapid cellular total uptake of the tracer at 30 min of incubation. Biodistribution showed low non-specific uptakes and rapid renal excretion. Melanoma tumors showed enhanced GX1 uptake in animal model at 60 min, and it was significantly blocked by cold peptide. The radiotracer showed tumor specificity, especially in melanomas that are highly vascularized tumors. In this sense, it should be considered in future studies, aiming to evaluate degree of angiogenesis, progression, and invasion of tumors.


  • IPEN-DOC 24767

    OLIVEIRA, FELIPE L. de; SANTOS, SOFIA N. dos ; RICON, LAUREMILIA; COSTA, THAYSE P. da; PEREIRA, JONATHAS X.; BRAND, CAMILA; FERMINO, MARISE L.; CHAMMAS, ROGER; BERNARDES, EMERSON S. ; EL-CHEIKH, MARCIA C.. Lack of galectin-3 modifies differentially Notch ligands in bone marrow and spleen stromal cells interfering with B cell differentiation. Scientific Reports, v. 8, n. 3495, p. 1-14, 2018. DOI: 10.1038/s41598-018-21409-7

    Abstract: Galectin-3 (Gal-3) is a beta-galactoside binding protein that controls cell-cell and cell-extracellular matrix interactions. In lymphoid organs, gal-3 inhibits B cell differentiation by mechanisms poorly understood. The B cell development is dependent on tissue organization and stromal cell signaling, including IL-7 and Notch pathways. Here, we investigate possible mechanisms that gal-3 interferes during B lymphocyte differentiation in the bone marrow (BM) and spleen. The BM of gal-3-deficient mice (Lgals3(-/-)mice) was evidenced by elevated numbers of B220(+)CD19(+)c-Kit(+)IL-7R(+) progenitor B cells. In parallel, CD45-bone marrow stromal cells expressed high levels of mRNA IL-7, Notch ligands (Jagged-1 and Delta-like 4), and transcription factors (Hes-1, Hey-1, Hey-2 and Hey-L). The spleen of Lgals3(-/-)mice was hallmarked by marginal zone disorganization, high number of IgM(+) IgD(+) B cells and CD138(+)plasma cells, overexpression of Notch ligands (Jagged-1, Delta-like 1 and Delta-like 4) by stromal cells and Hey-1. Morever, IgM(+) IgD(+) B cells and B220(+)CD138(+)CXCR4(+) plasmablasts were significantly increased in the BM and blood of Lgals3(-/-)mice. For the first time, we demonstrated that gal-3 inhibits Notch signaling activation in lymphoid organs regulating earlier and terminal events of B cell differentiation.


  • IPEN-DOC 24766

    OLIVEIRA, LEANDRO A. de; CORREA, OLANDIR V. ; SANTOS, DEMETRIO J. dos; PAEZ, ALEJANDRO A.Z.; OLIVEIRA, MARA C.L. de; ANTUNES, RENATO A.. Effect of silicate-based films on the corrosion behavior of the API 5L X80 pipeline steel. Corrosion Science, v. 139, p. 21-34, 2018. DOI: 10.1016/j.corsci.2018.04.035

    Abstract: The aim of this work was to investigate the effect of silicate-based films on the corrosion resistance of the API 5L X80 steel in carbonate-bicarbonate solution at room temperature. The films were electrochemically obtained by anodic and cathodic treatments and by immersion in 1.0 M sodium metasilicate solution. The corrosion behavior was evaluated using electrochemical impedance spectroscopy and potentiodynamic polarization. Film morphology was examined by scanning electron microscopy. Adhesion strength was measured by pull-off tests. The chemical composition was evaluated by X-ray photoelectron spectroscopy. The anodic film yielded the best corrosion resistance (protection efficiency 83%). The protection mechanism is discussed.


  • IPEN-DOC 24765

    FRANQUETTO, PAULO R. ; MATTAR NETO, MIGUEL . Experimental residual stress and geometric imperfections on pressure hull instability analysis. Journal of Offshore Mechanics and Arctic Engineering, v. 140, n. 3, 2018. DOI: 10.1115/1.4038582

    Abstract: Residual stress produced by cold bending and welding processes contributes to the collapse pressure reduction of submarine hulls. Usually, the residual stress profiles used to quantify this reduction are obtained from analytical or numerical models. However, such models have limitations to take into account cold bending and welding in the same time. Hence, experimental analyses are necessary to better quantify the residual stress. Based on that, this paper presents residual stress experimental results obtained at six points on a pressure hull prototype using X-ray portable system. Based on these results, the residual stress profiles through the material thickness were estimated for each region on the frame by using a polynomial approximation. These profiles were introduced in a nonlinear finite element numerical model to study the collapse pressure reduction. Experimental results available on the literature were also used. Material and geometric nonlinearities were considered in the analysis. The results show that the residual stress reduces the collapse pressure as part of the frame web has stress level higher than the material yield. The preload introduced by the residual stress plays a less important role for the collapse pressure reduction at higher out-of-roundness and out-of-straightness defect amplitudes.


  • IPEN-DOC 24764

    NEGRO, MIGUEL L.M. ; DURAZZO, MICHELANGELO ; MESQUITA, MARCO A. de; CARVALHO, ELITA F.U. de ; MESQUITA, ROBERTO N. de ; ANDRADE, DELVONEI A. de . Studies on capacity expansion of fuel plants for nuclear research reactors. World Journal of Nuclear Science and Technology, v. 8, n. 2, p. 38-53, 2018. DOI: 10.4236/wjnst.2018.82005

    Abstract: The demand for nuclear fuel for research reactors is rising worldwide. Thus, the production facilities of this kind of fuel need reliable guidance on how to augment their production in order to meet the increasing demand efficiently and safely. We proposed a specific procedure for increasing production ca-pacity. That procedure was tested with data from a real plant, which produces plate-type fuel elements loaded with LEU U3Si2-Al fuel. The test was made by means of discrete event simulation, and the results indicated the proposed procedure is efficient in raising production capacity.


  • IPEN-DOC 24763

    NASCIMENTO, M.H.M.; FRANCO, M.K.K.D. ; YOKAICHYIA, F.; PAULA, E. de; LOMBELLO, C.B.; ARAUJO, D.R. de. Hyaluronic acid in Pluronic F-127/F-108 hydrogels for postoperative pain in arthroplasties: Influence on physico-chemical properties and structural requirements for sustained drug-release. International Journal of Biological Macromolecules, v. 111, p. 1245-1254, 2018. DOI: 10.1016/j.ijbiomac.2018.01.064

    Abstract: In this study,we reported the hyaluronic acid (HA) on supramolecular structure of Pluronic F-127 (PLF-127) and/ or Pluronic F-108 (PLF-127) hydrogels, as well as their effects on release mechanisms, looking forward their application as lidocaine (LDC) drug-delivery systems in arthroplastic surgeries.We have studied the HA-micelle interaction using Dynamic Light Scattering (DLS), themicellization and sol-gel transition processes by Differential Scanning Calorimetry (DSC) and Rheology., of PL-based hydrogels and. The presence of HA provided the formation of larger micellar dimensions from ~26.0 to 42.4 nm. The incorporation of HA did not change the micellization temperatures and stabilized hydrogels rheological properties (G′ N G″), showing no interference on PLthermoreversible properties. Small-Angle-X-ray Scattering (SAXS) patterns revealed that HA incorporation effects were pronounced for PLF-127 and PLF-108 systems, showing transitions from lamellar to hexagonal phase organization (HA-PLF-127) and structural changes from cubic to gyroid and/or cubic to lamellar. The HA insertion effects were also observed on drug release profiles, since lower LDC release constants (Krel = 0.24–0.41 mM·h−1) were observed for HA-PLF-127, that presented a hexagonal phase organization. Furthermore, the HA-PL systems presented reduced in vitro cytotoxic effects, pointed out their tendency to selfassembly and possible application as drug delivery systems.


  • IPEN-DOC 24762

    MOSCA, RODRIGO C. ; YOUNG, NICHOLAS; ZEITUNI, CARLOS A. ; ARANY, PRAVEEN R.. [Ru(bipy)3]2+ nanoparticle-incorporate dental light cure resin to promote photobiomodulation therapy for enhanced vital pulp tissue repair. In: HAMBLIN, MICHAEL R. (Ed.); CARROLL, JAMES D. (Ed.); ARANY, PRAVEEN (Ed.) MECHANISMS OF PHOTOBIOMODULATION THERAPY, 13th, January 27 - February 01, 2018, San Francisco, California, USA. Proceedings... Bellingham, WA, USA: Society of Photo-optical Instrumentation Engineers, 2018. p. 104770T-1 - 104770T-6. (SPIE Proceedings Series, 10477). DOI: 10.1117/12.2290719

    Abstract: The use of nanoparticle on dental light cure resin is not new, currently several compounds (nanoadditives) are used to promote better communication between the restorative material and biological tissues. The interest for this application is growing up to enhance mechanical proprieties to dental tissue cells regeneration. Bioactive nanoparticles and complex compounds with multiple functions are the major target for optimizing the restorative materials. In this work, we incorporate [Ru(bipy)3]2+ nanoparticles, that absorbs energy at 450 nm (blue-light) and emits strongly at ~620 nm (red-light), in PLGA Microspheres and insert it in Dental Light Cure Resin to promote the Photobiomodulation Therapy (PBM) effects to accelerate dental pulp repair by in vitro using cytotoxicity and proliferation assay.


  • IPEN-DOC 24761

    MOREIRA, GREGORI de A. ; GUERRERO-RASCADO, JUAN L.; BENAVENT-OLTRA, JOSE; ORTIZ-AMEZCUA, PABLO; ROMAN, ROBERTO; LANDULFO, EDUARDO ; ALADOS-ARBOLEDAS, LUCAS. Studying turbulence by remote sensing systems during slope-2016 campaign. EPJ Web of Conferences, v. 176, n. 06010, p. 1-4, 2018. DOI: 10.1051/epjconf/201817606010

    Abstract: The Planetary Boundary Layer (PBL) is the lowermost part of the troposphere. In this work, we analysed some high order moments and PBL height detected continuously by three remote sensing systems: an elastic lidar, a Doppler lidar and a passive Microwave Radiometer, during the SLOPE-2016 campaign, which was held in Granada from May to August 2016. This study confirms the feasibility of these systems for the characterization of the PBL, helping us to justify and understand its behaviour along the day.


  • IPEN-DOC 24760

    MIRANDA, G.S.; OLIVEIRA, C.C.; SILVA, T.B.S.C.; STELLATO, T.B. ; MONTEIRO, L.R. ; MARQUES, J.R. ; FAUSTINO, M.G. ; SOARES, S.M.V.; ULRICH, J.C. ; PIRES, M.A.F. ; COTRIM, M.E.B. . Control chart on semi analytical weighting. Journal of Physics: Conference Series, v. 975, n. 012005, p. 1-4, 2018. DOI: 10.1088/1742-6596/975/1/012005

    Abstract: Semi-analytical balance verification intends to assess the balance performance using graphs that illustrate measurement dispersion, trough time, and to demonstrate measurements were performed in a reliable manner. This study presents internal quality control of a semianalytical balance (GEHAKA BG400) using control charts. From 2013 to 2016, 2 weight standards were monitored before any balance operation. This work intended to evaluate if any significant difference or bias were presented on weighting procedure over time, to check the generated data reliability. This work also exemplifies how control intervals are established.


  • IPEN-DOC 24759

    MILAGRE, MARIANA X. ; MOGILI, NAGA V.; DONATUS, UYIME ; GIORJAO, RAFAEL A.R.; TERADA, MAYSA; ARAUJO, JOAO V.S. ; MACHADO, CARULINE S.C. ; COSTA, ISOLDA . On the microstructure characterization of the AA2098-T351 alloy welded by FSW. Materials Characterization, v. 140, p. 233-246, 2018. DOI: 10.1016/j.matchar.2018.04.015

    Abstract: The complex structure of the AA2098-T351 alloy welded by friction stir welding (FSW) was investigated by transmission electron microscopy (TEM), differential scanning calorimetry (DSC) and microhardness measurements. Thermal modelling process of the FSW process was carried out by soldering thermocouples at distances of 6, 9 and 12 mm from the weld centerline, and thermocouple measurements were used as input data into the model. Finite element software COMSOL v5.2 was used for data analysis. The prevailing phases in the base metal (BM) are T1 (Al2CuLi) theta' (Al2Cu), delta'/beta'(Al-3(Li,Zr)) and Omega (Al2Cu). In the heat affected zone (HAZ), either in the retreating or advancing sides, theta' phase was not identified. In the thermomechanical affected zone (TMAZ), T1, delta'/beta', GP zones phase were detected in the retreating side, whereas T1 and Guinier-Preston (GP) zones were not observed in the advancing side. This result supports the asymmetric behavior observed in the microhardness profile of the weld. In the stir zone (SZ), GP zones, T1, delta'/beta' (Al-3(Li,Zr)) and Omega were identified.


  • IPEN-DOC 24758

    MESQUITA, ROBERTO N. de ; CASTRO, LEONARDO F. ; TORRES, WALMIR M. ; ROCHA, MARCELO da S. ; UMBEHAUN, PEDRO E. ; ANDRADE, DELVONEI A. ; SABUNDJIAN, GAIANE ; MASOTTI, PAULO H.F. . Classification of natural circulation two-phase flow image patterns based on self-organizing maps of full frame DCT coefficients. Nuclear Engineering and Design, v. 335, p. 161-171, 2018. DOI: 10.1016/j.nucengdes.2018.05.019

    Abstract: Many of the recent nuclear power plant projects use natural circulation as heat removal mechanism. The accuracy of heat transfer parameters estimation has been improved through models that require precise prediction of two-phase flow pattern transitions. Image patterns of natural circulation instabilities were used to construct an automated classification system based on Self-Organizing Maps (SOMs). The system is used to investigate the more appropriate image features to obtain classification success. An efficient automated classification system based on image features can enable better and faster experimental procedures on two-phase flow phenomena studies. A comparison with a previous fuzzy inference study was foreseen to obtain classification power improvements. In the present work, frequency domain image features were used to characterize three different natural circulation two-phase flow instability stages to serve as input to a SOM clustering algorithm. Full-Frame Discrete Cosine Transform (FFDCT) coefficients were obtained for 32 image samples for each instability stage and were organized as input database for SOM training. A systematic training/test methodology was used to verify the classification method. Image database was obtained from two-phase flow experiments performed on the Natural Circulation Facility (NCF) at Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN), Brazil. A mean right classification rate of 88.75% was obtained for SOMs trained with 50% of database. A mean right classificationrate of 93.98% was obtained for SOMs trained with 75% of data. These mean rates were obtained through 1000 different randomly sampled training data. FFDCT proved to be a very efficient and compact image feature to improve image-based classification systems. Fuzzy inference showed to be more flexible and able to adapt to simpler statistical features from only one image profile. FFDCT features resulted in more precise results when applied to a SOM neural network, though had to be applied to the full original grayscale matrix for all flow images to be classified.


  • IPEN-DOC 24757

    MARQUES, J.R. ; FAUSTINO, M.G. ; MONTEIRO, L.R. ; ULRICH, J.C. ; PIRES, M.A.F. ; COTRIM, M.E.B. . Is my bottom-up uncertainty estimation on metal measurement adequate?. Journal of Physics: Conference Series, v. 975, n. 012009, p. 1-4, 2018. DOI: 10.1088/1742-6596/975/1/012009

    Abstract: Is the estimated uncertainty under GUM recommendation associated with metal measurement adequately estimated? How to evaluate if the measurement uncertainty really covers all uncertainty that is associated with the analytical procedure? Considering that, many laboratories frequently underestimate or less frequently overestimate uncertainties on its results; this paper presents the evaluation of estimated uncertainties on two ICP-OES procedures of seven metal measurements according to GUM approach. Horwitz function and proficiency tests scaled standard uncertainties were used in this evaluation. Our data shows that most elements expanded uncertainties were from two to four times underestimated. Possible causes and corrections are discussed herein.


  • IPEN-DOC 24756

    MARQUES, MARCIA T.A. ; MOREIRA, GREGORI de A. ; PINERO, MACIEL; OLIVEIRA, AMAURI P.; LANDULFO, EDUARDO . Estimating the planetary boundary layer height from radiosonde and doppler lidar measurements in the city of São Paulo - Brazil. EPJ Web of Conferences, v. 176, n. 06015, p. 1-4, 2018. DOI: 10.1051/epjconf/201817606015

    Abstract: This study aims to compare the planetary boundary layer height (PBLH) values estimated by radiosonde data through the bulk Richardson number (BRN) method and by Doppler lidar measurements through the Carrier to Noise Ratio (CNR) method, which corresponds to the maximum of the variance of CNR profile. The measurement campaign was carried during the summer of 2015/2016 in the city of São Paulo. Despite the conceptual difference between these methods, the results show great agreement between them.


  • IPEN-DOC 24755

    MARQUES, L.S.; DE MIN, A.; ROCHA-JUNIOR, E.R.V.; BABINSKI, M.; BELLIENI, G.; FIGUEIREDO, A.M.G. . Elemental and Sr-Nd-Pb isotope geochemistry of the Florianópolis Dyke Swarm (Paraná Magmatic Province): crustal contamination and mantle source constraints. Journal of Volcanology and Geothermal Research, v. 355, n. SI, p. 149-164, 2018. DOI: 10.1016/j.jvolgeores.2017.07.005

    Abstract: The Florianópolis Dyke Swarm is located in Santa Catarina Island, comprising also the adjacent continental area, and belongs to the Paraná Magmatic Province (PMP). The dyke outcrops in the island are 0.1–70 m thick and most of them are coast-parallel (NE-SWtrending), with subordinate NW-SE trending. The vast majority of the dykes has SiO2 varying from 50 to 55 wt% and relatively high-Ti (TiO2 N 3 wt%) contents and these rocks were divided using the criteria commonly used to distinguish the different magma-types identified in the volcanic rocks fromthe PMP. The Urubici dykes (Sr N 550 μg/g) are themost abundant and some of them experienced crustal contamination reaching to 10%, as evidenced by low P2O5/K2O (0.30–0.21), high (Rb/Ba)PM (1.0–2.2), and radiogenic Sr and Pb isotope compositions (87Sr/86Sri up to 0.70716 (back to 125 Ma) and 206Pb/204Pbm up to 19.093). The Pitanga (Sr b 550 μg/g) and the basaltic trachyandesite dykes are less abundant and almost all of them were also substantially affected by at least 15% of crustal assimilation, evidenced by high (Rb/Ba)PM (up to 2.6) and Sr (87Sr/86Sri = 0.70737–0.71758) and Pb (206Pb/204Pbm = 18.446–19.441) isotope ratios, as well as low P2O5/K2O values (0.30–0.18). The low-Ti (TiO2 b 2 wt%) dykes are scarce and show a large compositional variability (SiO2: 50.4–64.5 wt%), with similar geochemical characteristics of the low-Ti volcanic rocks (Gramado-Palmas) from southern PMP, although the most primitive dykes show hybrid characteristics of Ribeira and Esmeralda magmas. The presence of granitic xenoliths with border reactions and dykeswith diffuse contacts indicate that crustal contamination probably occurred by assimilation from re-melted the host rocks. Considering only the high-Ti Urubici dykes that were not affected by crustal contamination, the Sr, Nd and Pb isotope mixing modelling indicates the participation of a heterogeneous metasomatized (refertilized) subcontinental lithospheric mantle (SCLM). This mantle source was originated by partial melting of a depleted sublithospheric mantle (DMM – Depleted Mantle MORB), which was hybridized by addition of pyroxenite (b5%) and carbonatite (up to 2%) melts. The isotope mixing modelling also points to a significant participation (up to 50%) of Archean SCLM, not evidenced in the mantle sources of the northern PMP high-Ti Pitanga flows (dominated by Neoproterozoic SCLM).


  • IPEN-DOC 24754

    MARANI, DEBORA; MORAES, LETICIA P.R. ; GUALANDRIS, FABRIZIO; SANNA, SIMONE; FLORIO, DANIEL Z. de; ESPOSITO, VINCENZO; FONSECA, FABIO C. . Nucleation front instability in two-dimensional (2D) nanosheet gadolinium-doped cerium oxide (CGO) formation. CrystEngComm, v. 20, n. 10, p. 1405-1410, 2018. DOI: 10.1039/c7ce01737e

    Abstract: Herein we report for the first time the synthesis of ceramic-organic three-dimensional (3D) layered gadolinium-doped cerium oxide (Ce1-XGdXO2-delta,CGO) and its exfoliation into two-dimensional (2D) nano-sheets. We adopt a water-based synthetic route via a homogenous precipitation approach at low temperatures (10-80 degrees C). The reaction conditions are tuned to investigate the effects of thermal energy on the final morphology. A low temperature (40 degrees C) morphological transition from nanoparticles (1D) to two-dimensional (2D) nanosheets is observed and associated with a low thermal energy transition of ca. 2.6 kJ mol(-1). For the 3D-layered material, exfoliation experiments are conducted in water/ethanol solutions. Systems at volume fractions ranging from 0.15 to 0.35 are demonstrated to promote under ultrasonic treatment the delamination into 2D nanosheets.


  • IPEN-DOC 24753

    MANTECON, JAVIER G. ; MATTAR NETO, MIGUEL . Numerical methodology for fluid-structure interaction analysis of nuclear fuel plates under axial flow conditions. Nuclear Engineering and Design, v. 333, p. 76-86, 2018. DOI: 10.1016/j.nucengdes.2018.04.009

    Abstract: Shell-type fuel elements are widely used in nuclear research reactors. The nuclear fuel is contained in parallel shells, flat or curved, that are separated by narrow channels through which the fluid flows to remove the heat generated by fission reactions. A major problem of this fuel assembly design is the hydraulic instability of the shells caused by the high flow velocities. The objective of the study presented here is the development of a fluid-structure interaction methodology to investigate numerically the onset of hydroelastic instability of flat-shell-type fuel elements, also known as plate-type fuel assemblies, under axial flow conditions. The system analyzed consists of two nuclear fuel plates bounded by three-equal coolant channels. It is developed using the commercial codes ANSYS CFX for modeling the fluid flow and ANSYS Mechanical to model the plates. The fluid-structure interaction methodology predicts a behavior consistent with other theoretical and experimental works. Particularly, the maximum deflection of the plates is detected at the leading edge and it is a linear function of the square of the fluid velocity up to the Miller’s theoretical value. For velocities above this value, a nonlinear relationship is observed. This relationship indicates that structural changes are taking place in the plates. Furthermore, for fluid velocities greater than the Miller’s velocity, an extra deflection peak is observed near the trailing edge of the plates. Thus, structural alterations also happen along the length of the flat-shells.


  • IPEN-DOC 24751

    GONZALES-LORENZO, CARLOS D.; WATANABE, SHIGUEO; CANO, NILO F.; AYALA-ARENAS, JORGE S.; BUENO, CARMEN C. . Synthetic polycrystals of CaSiO3 un-doped and Cd, B, Dy, Eu-doped for gamma and neutron detection. Journal of Luminescence, v. 201, p. 5-10, 2018. DOI: 10.1016/j.jlumin.2018.04.037

    Abstract: The undoped and B, Cd, Dy, Eu doped synthetic CaSiO3 polycrystals were produced in the laboratory. They are very sensitive γ-ray detectors with main prominent TL peak occurring at about 270 °C, this peak was obtained using 4 °C/s heating rate. The TL behavior changes very little by doping with B, Cd and Dy while Eu doping brings changes. These minerals can be used also for neutron dosimetry. Thermal neutrons react with Ca, Si and O through (n, γ) process and γ emitted in this reaction added to γ-rays of the reactor that produces thermal neutrons and are responsible for induction of thermoluminiscence. The TL response of CaSiO3 is linear for dose < 10 Gy and then has a supralinear behavior up to about 7 kGy and saturating beyond.


  • IPEN-DOC 24750

    LOPES, FABIO J.S. ; GUERRERO-RASCADO, JUAN L.; BENAVENT-OLTRA, JOSE A.; ROMAN, ROBERTO; MOREIRA, GREGORI A. ; MARQUES, MARCIA T.A. ; SILVA, JONATAN J. da ; ALADOS-ARBOLEDAS, LUCAS; ARTAXO, PAULO; LANDULFO, EDUARDO . Rehearsal for assessment of atmospheric optical properties during biomass burning events and long-range transportation episodes at metropolitan area of São Paulo-Brazil (RAPEL). EPJ Web of Conferences, v. 176, n. 08011, p. 1-4, 2018. DOI: 10.1051/epjconf/201817608011

    Abstract: During the period of August-September 2016 an intensive campaign was carried out to assess aerosol properties in São Paulo-Brazil aiming to detect long-range aerosol transport events and to characterize the instrument regarding data quality. Aerosol optical properties retrieved by the GALION - LALINET SPU lidar station and collocated AERONET sunphotometer system are presented as extinction/ backscatter vertical profiles with microphysical products retrieved with GRASP inversion algorithm.


  • IPEN-DOC 24749

    LEVY, D.S. ; SORDI, G.M.A.A. ; VILLAVICENCIO, A.L.C.H. . Construindo pontes entre ciência e sociedade: divulgação científica sobre irradiação de alimentos. Brazilian Journal of Radiation Sciences, v. 6, n. 1, p. 01-13, 2018. DOI: 10.15392/bjrs.v6i1.343

    Abstract: A irradiação de alimentos é uma técnica de preservação segura e eficaz para eliminar insetos e reduzir microrganismos prejudiciais à saúde humana. O processo contribui para inibir o brotamento e retardar o amadurecimento dos alimentos, prolongando a vida útil de frutas e legumes frescos. Entretanto, dentre uma grande parcela da população brasileira, ainda há grande desinformação sobre as aplicações pacíficas das ciências nucleares. Não raramente a mídia e as redes sociais tendem a associar a radiação ionizante a armas nucleares e acidentes de grandes proporções. A desinformação compromete a percepção do público: consumidores acabam por associar alimentos irradiados a alimentos radioativos ou contaminados. O público demonstra grandes preocupações quanto aos efeitos negativos das radiações para a saúde e riscos de contaminação ambiental. Os julgamentos e tomadas de decisões por parte da sociedade estão diretamente ligados à sua percepção dos riscos e benefícios advindos da Tecnologa Nuclear. Este artigo apresenta algumas considerações sobre as percepções do público a respeito dos alimentos irradiados, bem como algumas ações de divulgação científica, para aproximar ciência e sociedade. Cabe à comunidade científica construir novas pontes entre as ciências nucleares e o público leigo, oferecendo uma perspectiva mais ampla sobre as aplicações pacíficas das radiações ionizantes e suas contribuições na vida cotidiana.


  • IPEN-DOC 24748

    LAPENA, MAURO H.; MARINUCCI, GERSON . Mechanical characterization of basalt and glass fiber epoxy composite tube. Materials Research - Ibero-American Journal of Materials, v. 21, n. 1, p. 1-7, 2018. DOI: 10.1590/1980-5373-MR-2017-0324

    Abstract: The application of basalt fibers are possible in many areas thanks to its multiple and good properties. It exhibits excellent resistance to alkalis, similar to glass fiber, at a much lower cost than carbon and aramid fibers In the present paper, a comparative study on mechanical properties of basalt and E-glass fiber composites was performed. Results of apparent hoop tensile strength test of ring specimens cut from tubes and the interlaminar shear stress (ILSS) test are presented Tensile tests using split disk method provide reasonably accurate properties with regard to the apparent hoop tensile strength of polymer reinforced composites Comparison between the two tubes showed higher basalt fiber composite performance on apparent hoop tensile strength (45% higher) and on the interfacial property interlaminar shear stress (ILSS) (11% higher) New data obtained in this work on basalt fiber composite tubes confirm the literature for basalt fiber composite with other geometries, where it overcomes mechanical properties of the widely used glass fiber composites.


  • IPEN-DOC 24747

    LANGE, CAMILA N. ; FIGUEIREDO, ANA M.G. ; ENZWEILER, JACINTA; MONTEIRO, LUCILENA R. . Potentially toxic elements downward mobility in an impounded vehicle scrapyard. Journal of Radioanalytical and Nuclear Chemistry, v. 316, n. 2, p. 819-830, 2018. DOI: 10.1007/s10967-018-5729-0

    Abstract: In Brazil impounded vehicle scrapyards (IVS) are often overcrowded and may pose a source of potentially toxic elements (PTEs). In this study, PTEs content in soil cores and groundwater of an IVS located at a municipality of the So Paulo metropolitan region was assessed. INAA, XRF and ICP-MS were the analytical techniques employed. PTEs results and statistical approaches indicated that As, Pb, Ni, Cu and Nb are mostly anthropic. Pb, Cu, Ni and Nb mass fraction increased with depth indicating some downward mobility. Arsenic may represent a moderate to very high potential ecological risk. PTEs groundwater levels were bellow drinking water recommendation limits.


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A pesquisa apresentará melhor resultado selecionando um dos filtros disponíveis em Navegar

Os filtros disponíveis em Navegar tais como: Coleções, Ano de publicação, Títulos, Assuntos, Autores, Revista, Tipo de publicação são autoexplicativos. O filtro, Autores IPEN apresenta uma relação com os autores vinculados ao IPEN; o ID Autor IPEN diz respeito ao número único de identificação de cada autor constante no RD e sob o qual estão agrupados todos os seus trabalhos independente das variáveis do seu nome; Tipo de acesso diz respeito à acessibilidade do documento, isto é , sujeito as leis de direitos autorais, ID RT apresenta a relação dos relatórios técnicos, restritos para consulta das comunidades indicadas.

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Buscar os artigos apresentados em um evento internacional de 2015, sobre loss of coolant, do autor Maprelian.

Autor: Maprelian

Título: loss of coolant

Tipo de publicação: Texto completo de evento

Ano de publicação: 2015

Para indexação dos documentos é utilizado o Thesaurus do INIS, especializado na área nuclear e utilizado em todos os países membros da International Atomic Energy Agency – IAEA , por esse motivo, utilize os termos de busca de assunto em inglês; isto não exclui a busca livre por palavras, apenas o resultado pode não ser tão relevante ou pertinente.

95% do RD apresenta o texto completo do documento com livre acesso, para aqueles que apresentam o significa que e o documento está sujeito as leis de direitos autorais, solicita-se nesses casos contatar a Biblioteca do IPEN, bibl@ipen.br .

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O gerenciamento do Repositório está a cargo da Biblioteca do IPEN. Constam neste RI, até o presente momento 20.950 itens que tanto podem ser artigos de periódicos ou de eventos nacionais e internacionais, dissertações e teses, livros, capítulo de livros e relatórios técnicos. Para participar do RI-IPEN é necessário que pelo menos um dos autores tenha vínculo acadêmico ou funcional com o Instituto. Nesta primeira etapa de funcionamento do RI, a coleta das publicações é realizada periodicamente pela equipe da Biblioteca do IPEN, extraindo os dados das bases internacionais tais como a Web of Science, Scopus, INIS, SciElo além de verificar o Currículo Lattes. O RI-IPEN apresenta também um aspecto inovador no seu funcionamento. Por meio de metadados específicos ele está vinculado ao sistema de gerenciamento das atividades do Plano Diretor anual do IPEN (SIGEPI). Com o objetivo de fornecer dados numéricos para a elaboração dos indicadores da Produção Cientifica Institucional, disponibiliza uma tabela estatística registrando em tempo real a inserção de novos itens. Foi criado um metadado que contém um número único para cada integrante da comunidade científica do IPEN. Esse metadado se transformou em um filtro que ao ser acionado apresenta todos os trabalhos de um determinado autor independente das variáveis na forma de citação do seu nome.

A elaboração do projeto do RI do IPEN foi iniciado em novembro de 2013, colocado em operação interna em julho de 2014 e disponibilizado na Internet em junho de 2015. Utiliza o software livre Dspace, desenvolvido pelo Massachusetts Institute of Technology (MIT). Para descrição dos metadados adota o padrão Dublin Core. É compatível com o Protocolo de Arquivos Abertos (OAI) permitindo interoperabilidade com repositórios de âmbito nacional e internacional.

1. Portaria IPEN-CNEN/SP nº 387, que estabeleceu os princípios que nortearam a criação do RDI, clique aqui.

2. A experiência do Instituto de Pesquisas Energéticas e Nucleares (IPEN-CNEN/SP) na criação de um Repositório Digital Institucional – RDI, clique aqui.