REPOSITÓRIO DIGITAL DA PRODUÇÃO TÉCNICO CIENTÍFICA

 

 

 

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O Repositório Digital do IPEN é um equipamento institucional de acesso aberto, criado com o objetivo de reunir, preservar, disponibilizar e conferir maior visibilidade à Produção Científica publicada pelo Instituto, desde sua criação em 1956.

Operando, inicialmente como uma base de dados referencial o Repositório foi disponibilizado na atual plataforma, em junho de 2015. No Repositório está disponível o acesso ao conteúdo digital de artigos de periódicos, eventos, nacionais e internacionais, livros, capítulos, dissertações, teses e relatórios técnicos. [Saiba mais]

 

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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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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).

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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

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  • 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).

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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  • 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.

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ATENÇÃO!

ESTE TEXTO "AJUDA" ESTÁ SUJEITO A ATUALIZAÇÕES CONSTANTES, A MEDIDA QUE NOVAS FUNCIONALIDADES E RECURSOS DE BUSCA FOREM SENDO DESENVOLVIDOS PELAS EQUIPES DA BIBLIOTECA E DA INFORMÁTICA.

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.