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BibliotecaTerezine Arantes Ferraz

Navegação Periódicos - Artigos por Agências de fomento "Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)"

Navegação Periódicos - Artigos por Agências de fomento "Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)"

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  • IPEN-DOC 26393

    FERREIRA, EDUARDO G.A. ; MARUMO, JULIO T. ; FRANCO, MARGARETH K.K.D. ; YOKAICHIYA, FABIANO; VICENTE, ROBERTO . 10000 years cement: Can hydrated cement last as much as long-lived radionuclides?. Cement and Concrete Composites, v. 103, p. 339-352, 2019. DOI: 10.1016/j.cemconcomp.2019.05.016

    Abstract: This review is focused on the long-term performance of cementitious materials in a repository for radioactive waste. During the last few years, the disposal of disused sealed radioactive sources (DSRS) in a borehole type repository has been studied by many countries. The borehole concept is particularly useful to dispose of spent nuclear fuel and DSRS. In boreholes for DSRS, cementitious materials are intended to be used as structural material, immobilization matrix and as backfill. The understanding of the performance of these materials is essential to ensure the safety of the facilities during their required lifetime, from centuries to many thousands of years, depending on the initial activity and half-life of the waste. This review approaches the behavior of the cement from the hydration and hardening to the long-term processes that can affect its durability. Three main causes of failure of repository-engineered barriers are recognized: a) the formation of a preferential pathway for the migration of the contained radionuclides to the biosphere; b) loss of resistance and cohesion of the structural cementitious material; and c) the increase in the corrosion processes of the metallic components of the structures that affect the overall containment of the facility.

    Palavras-Chave: cements; cement industry; portland cement; radioactive wastes; geologic formations; underground disposal; performance; chemical composition; mineralogy; radiations; magnetic fields; hydration


  • IPEN-DOC 23152

    BERECZKI, ALLAN ; WETTER, NIKLAUS U. . 100W continuous linearly polarized, high beam quality output from standard side-pumped Nd:YAG laser modules. Optics and Laser Technology, v. 96, p. 271-275, 2017. DOI: 10.1016/j.optlastec.2017.05.020

    Abstract: Dynamically stable operation with joined stability zones of a linearly polarized resonator is shown for a laser containing two diode side-pumped Nd:YAG rods. The unpolarized resonator generated 115W of output. When polarized by a Brewster plate, it reached 100.5W of output power at a beam quality M2 < 2. Best measured beam quality was of 1.1 and 1.3 in the x and y directions respectively, with 76W of 95% polarized output. The output power achieved is, to our knowledge, the highest reported for continuous polarized, fundamental-mode lasers using standard side-pumped Nd:YAG modules.

    Palavras-Chave: neodymium lasers; lasers; resonators; solid state lasers; temperature dependence; diode-pumped solid state lasers; beams; quality factor


  • IPEN-DOC 26398

    PAPAI, RODRIGO; FREITAS, MILLENA A.S. de; FONSECA, KARINA T. da; ALMEIDA, GILMAR A. de ; SILVEIRA, JOÃO R.F. da; SILVA, ANDRE L.N. da; FERREIRA NETO, JOÃO B.; SANTOS, CELIA A.L. dos; LANDGRAF, FERNANDO J.G.; LUZ, MACIEL S.. Additivity of optical emissions applied to neodymium and praseodymium quantification in metallic didymium and (Nd,Pr)-Fe-B alloy samples by low-resolution atomic emission spectrometry: an evaluation of the mathematical approach used to solve spectral interferences. Analytica Chimica Acta, v. 1085, p. 21-28, 2019. DOI: 10.1016/j.aca.2019.07.049

    Abstract: In this work, the effectiveness of a mathematical approach to solve the spectral interferences involved in the optical emission of two chemical species (neodymium and praseodymium) when using monochromators with low-resolution in atomic spectrometry is evaluated. Although recent technological advances have promoted spectrometers equipped with high-resolution monochromators, which have a great instrumental capability in the separation of nearby lines and consequently avoid spectral interferences, many laboratories still have old spectrometers installed with insufficient resolution to overcome such interferences. In order to evaluate a mathematical approach based on Lambert-Beer's Law, the optical emissions of neodymium and praseodymium were monitored on a low-resolution (200 pm) flame atomic emission spectrometry (F-AES). These two elements were strategically chosen as an application model because they exhibit similar physicochemical properties, joint occurrence in nature and because they are increasingly used in the manufacture of super-magnets, a material increasingly required by the high technology industry. The effectiveness of the mathematical approach was evaluated in three different ways: (i) by recovery of the analytes in synthetic mixtures containing known quantities of the species; (ii) by spike and recovery trials on a representative blend of dissolved samples and (iii) by comparing the results obtained with another analytical method: Inductively coupled plasma optical emission spectrometry (ICP-OES) with a higher spectral resolution. The results indicate the effectiveness of this simple mathematical approach, allow the “survival” of instruments equipped with low-resolution monochromators and demonstrate the applicability of this approach to spectral correction. In addition, this work contributes an analytical method for the quantification of neodymium and praseodymium in metallic alloy samples involved in the production of super-magnets, aiding in the strict quality control of these materials.

    Palavras-Chave: additives; emission; absorption spectroscopy; neodymium; praseodymium; spectra; interference; atoms


  • IPEN-DOC 27164

    BENALCAZAR JALKH, E.B.; BERGAMO, E.T.P.; MONTEIRO, K.N.; CESAR, P.F.; GENOVA, L.A. ; LOPES, A.C.O.; LISBOA FILHO, P.N.; COELHO, P.G.; SANTOS, C.F.; BORTOLIN, F.; PIZA, M.M.T.; BONFANTE, E.A.. Aging resistance of an experimental zirconia-toughened alumina composite for large span dental prostheses: optical and mechanical characterization. Journal of the Mechanical Behavior of Biomedical Materials, v. 104, p. 1-9, 2020. DOI: 10.1016/j.jmbbm.2020.103659

    Abstract: Purpose: To synthesize a zirconia-toughened alumina (ZTA) composite with 85% alumina matrix reinforced by 15% zirconia and to characterize its optical and mechanical properties before and after artificial aging, to be compared with a conventional dental zirconia (3Y-TZP). Material and methods: After syntheses, ZTA and 3Y-TZP powders were uniaxially and isostatically pressed. Greenbody samples were sintered and polished to obtain 80 disc-shaped specimens per group (12 x 1 mm, ISO 6872:2015). The crystalline content and microstructure were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). Optical properties were determined by the calculation of contrast ratio (CR) and translucency parameter (TP) using reflectance data. Mechanical properties were assessed by Vickers hardness, fracture toughness and biaxial flexural strength test (BFS). All analyses were conducted before and after artificial aging (20h, 134 °C, 0.22 MPa). Optical parameters and microhardness differences were evaluated through repeated-measures analysis of variance (p < 0.05). BFS data were analyzed using Weibull statistics (95% CI). Results: The synthesis of the experimental ZTA composite was successful, with 98% of theoretical density, as shown in the SEM images. XRD patterns revealed typical zirconia and alumina crystalline phases. ZTA optical properties parameters showed no effect of aging, with a high CR and low TP values denoting a high maskingability. 3Y-TZP presented lower masking-ability and aging significantly affected its optical properties. ZTA Vickers hardness, fracture toughness and Weibull parameters, including characteristic stress and Weibull modulus were not influenced by aging, while 3Y-TZP presented a significant decrease in characteristic stress and increase in fracture toughness after aging. The ZTA probability of survival for missions of 300 and 500 MPa was estimated at ~99% validating its use for 3-unit posterior fixed dental prostheses (FDP), and no different from conventional 3Y-TZP. At high-stress mission (800 MPa) a significant decrease in probability of survival was observed for aged 3Y-TZP (84%) and for immediate and aged ZTA (73 and 82% respectively). Conclusion: The ZTA composite presented a dense microstructure, with preservation of the crystalline content, optical and mechanical properties after artificial aging, which encourages future research to validate its potential use for large span FDP.

    Palavras-Chave: aluminium oxides; zirconium oxides; aging; ceramics; microstructure; optical properties; optical microscopes


  • IPEN-DOC 27560

    JALKH, ERNESTO B.B.; MONTEIRO, KELLI N.; CESAR, PAULO F.; GENOVA, LUIS A. ; BERGAMO, EDMARA T.P.; LOPES, ADOLFO C. de O.; LIMA, ERICK; LISBOA-FILHO, PAULO N.; CAMPOS, TIAGO M.B.; WITEK, LUKASZ; COELHO, PAULO G.; BORGES, ANA F.S.; BONFANTE, ESTEVAM A.. Aging resistant ZTA composite for dental applications: microstructural, optical and mechanical characterization. Dental Materials, v. 36, n. 9, p. 1190-1200, 2020. DOI: 10.1016/

    Abstract: Objective. To synthesize a zirconia toughened alumina (ZTA) composite with 70% aluminareinforced by 30% zirconia for dental applications and to characterize its microstructureand optical properties for comparison with the isolated counterpart materials and a first-generation 3Y-TZP.Methods. Disc-shaped specimens were divided in four groups (n = 70/material): (1) 3YSB-E(first generation 3Y-TZP), (2) Zpex (second generation 3Y-TZP), (3) alumina, and (4) ZTA-Zpex70/30. After synthesis, ceramic powders were pressed, and green-body samples sinteredfollowing a predetermined protocol. Specimens were polished to obtain a mirror surfacefinish. Apparent density was measured by Archimedes principle. X-ray diffraction (XRD)and scanning electron microscope (SEM) were used to characterize the crystalline contentand microstructure. Reflectance tests were performed to determine the contrast-ratio (CR)and translucency-parameter (TP). Mechanical properties were assessed by biaxial flexuralstrength (BFS) test. All analyses were conducted before and after artificial aging (20 h, 134◦C, 2.2 bar). Optical parameters were evaluated through repeated-measures analysis of variance and Tukey tests (p < 0.05). BFS data were analyzed using Weibull statistics (95% CI). Results. High density values (95–99%) were found for all ceramic materials and SEM images exhibited a dense microstructure. While XRD patterns revealed the preservation of crys- talline content in the ZTA composite, an increase in the monoclinic peak was observed for pure zirconias after aging. Significantly higher CR and lower TP values were observed for the ZTA composite, followed by alumina, 3YSB-E, and Zpex. The highest characteristic stress was recorded for 3YSB-E, followed by intermediate values between ZTA and Zpex, and the lowest for alumina. Aging affected the optical and mechanical properties of both zirconias, while remained stable for ZTA composite and alumina. Significance. The synthesis of experimental 70−30% ZTA composite was successful and its relevance for dental applications relies on its higher masking ability, aging resistance, and strength similar to zirconia.


  • IPEN-DOC 26399

    ROVANI, SUZIMARA ; SANTOS, JONNATAN J.; CORIO, PAOLA; FUNGARO, DENISE A. . An alternative and simple method for the preparation of bare silica nanoparticles using sugarcane waste ash, an abundant and despised residue in the Brazilian industry. Journal of the Brazilian Chemical Society, v. 30, n. 7, p. 1524-1533, 2019. DOI: 10.21577/0103-5053.20190049

    Abstract: Sugarcane waste ash, a Si-rich waste product, is generated in large quantities and creates a serious disposal problem in the Brazilian ethanol-sugar industry, affecting the environment and public health. Here, a simple method capable of generating bare silica nanoparticles utilizing this residue is demonstrated. Firstly, the crystalline silica present in sugarcane waste ash (SWA) was converted into amorphous by melting a mixture of sodium hydroxide and SWA at 550 °C for 1 h. The silica nanoparticles (SiO2NPs) were formed by lowing pH. This production process of SiO2NPs from SWA was optimized varying the ash:NaOH mass ratio, increasing the silica extraction up to 96%. The sample’s composition was characterized by total X-ray fluorescence spectroscopy, morphology and physical-chemical properties were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction, specific surface area measurements, Fourier-transform infrared spectroscopy (FTIR) and thermogravimetric analyses (TGA), followed by use as adsorbent for the removal of methylene blue dye. With this process of extraction, nanoparticles smaller than 100 nm were generated, with a surface area of 63 m2 g-1 and a maximum adsorption capacity of 37 mg g-1 for methylene blue. The results indicate a successful process for obtaining an adsorbent from an industrial waste product using a cost effective and rapid synthesis procedure rendering renewable product.

    Palavras-Chave: sugar cane; wastes; adsorbents; silica; nanoparticles; ethanol fuels; ashes; sodium hydroxides; agriculture; agricultural wastes


  • IPEN-DOC 26862

    GARCIA, PAULO R.A.F.; PRYMAK, OLEG; GRASMIK, VIKTORIA; PAPPERT, KEVIN; WLYSSES, WAGNER; OTUBO, LARISSA ; EPPLE, MATTHIAS; OLIVEIRA, CRISTIANO L.P.. An in situ SAXS investigation of the formation of silver nanoparticles and bimetallic silver–gold nanoparticles in controlled wet-chemical reduction synthesis. Nanoscale Advances, v. 2, n. 1, p. 225-238, 2020. DOI: 10.1039/c9na00569b

    Abstract: We present a study on the formation of silver (Ag) and bimetallic silver–gold (AgAu) nanoparticlesmonitored by in situ SAXS as well as by ex situ TEM, XRD and UV-vis analysis in a flow reactor at controlled reaction temperature. The formation mechanism of the nanoparticles is derived from the structural parameters obtained from the experimental data. The evolution of the average particle size of pure and alloyed nanoparticles shows that the particle growth occurs initially by a coalescence mechanism. The later growth of pure silver nanoparticles is well described by Ostwald ripening and for the alloyed nanoparticles by a process with a significantly slower growth rate. Additionally, the SAXS data of pure silver nanoparticles revealed two major populations of nanoparticles, the first one with a continuous crystal growth to a saturation plateau, and the second one probably with a continuous emergence of small new crystals. The particle sizes obtained by SAXS agree well with the results from transmission electron microscopy and X-ray diffraction. The present study demonstrates the capability of an in situ investigation of synthesis processes using a laboratory based SAXS instrument. Online monitoring of the synthesis permitted a detailed investigation of the structural evolution of the system.

    Palavras-Chave: nanoparticles; small angle scattering; x-ray diffraction; silver; bimetals; gold; monte carlo method; nanostructures; alloys


  • IPEN-DOC 25206

    FREITAS, LUCAS F. de ; VARCA, GUSTAVO H.C. ; BATISTA, JORGE G. dos S. ; LUGAO, ADEMAR B. . An overview of the synthesis of gold nanoparticles using radiation technologies. Nanomaterials, v. 8, n. 11, 2018. DOI: 10.3390/nano8110939

    Abstract: At a nano-level, optical properties of gold are unique and gave birth to an emerging platform of nanogold-based systems for diverse applications, because gold nanoparticle properties are tunable as a function of size and shape. Within the available techniques for the synthesis of gold nanoparticles, the radiolytic synthesis allows proper control of the nucleation process without the need for reducing agents, in a single step, combined or not with simultaneous sterilization. This review details and summarizes the use of radiation technologies for the synthesis and preparation of gold nanoparticles concerning fundamental aspects, mechanism, current pathways for synthesis and radiation sources, as well as briefly outlines final applications and some toxicity aspects related to nanogold-based systems.

    Palavras-Chave: gold; nanoparticles; gamma radiation; electron beams; x-ray sources; radiolysis; nanotechnology; medicine; diagnostic uses; ionizing radiations


  • IPEN-DOC 25738

    ROVANI, S. ; MEDEIROS, L.F.; LIMA, E.C.; FERNANDES, A.N.. Application of biochar from agro‑industrial waste in solid‑phase extraction for the determination of 17β‑estradiol from aqueous solution. International Journal of Environmental Science and Technology, v. 16, n. 12, p. 7623-7630, 2019. DOI: 10.1007/s13762-019-02295-6

    Observação: Correction anexado. International Journal of Environmental Science and Technology, v. 16, p. 7631, 2019. DOI: 10.1007/s13762-019-02433-0

    Abstract: In this study, the biochar produced from coffee wastes and eucalyptus sawdust was employed as an adsorbent in solid-phase extraction devices for the determination of 17β-estradiol from aqueous solution. Parameters such as adsorbent mass, solvent type, eluent volume, ionic strength, breakthrough volume, and the cartridge reuse were evaluated. The best experimental conditions for solid-phase extraction concerning adsorbent mass, elution solvent, eluent volume, ionic strength, breakthrough volume, and cartridge reuse were established. The most suitable conditions for 1.0-mL cartridge were: mass of 50 mg, elution solvent 5.0 mL of acetonitrile/water 90:10 (v:v), 0.003 mol L−1 NaCl concentration, and 17β-estradiol solution volume 50.0 mL. The solid-phase extraction results showed that, although 17β-estradiol recovery was about 60%, the removal efficiency was 100% and the cartridges of 200 and 500 mg can be reused eight and four times, respectively, without any decrease in adsorption capacity. The results demonstrate the potential use of biochar as new adsorbent in solid-phase extraction devices for the removal of estrogens in aqueous solution.

    Palavras-Chave: charcoal; wood fuels; solid wastes; adsorbents; hormones; estradiol; agriculture; agricultural wastes


  • IPEN-DOC 23215

    VILLANI, DANIEL; MANCINI, ANSELMO; HADDAD, CECILIA M.K.; CAMPOS, LETICIA L. . Application of optically stimulated luminescence ‘nanoDot’ dosimeters for dose verification of VMAT treatment planning using an anthropomorphic stereotactic end-to-end verification phantom. Radiation Measurements, p. 1-5, 2017. DOI: 10.1016/j.radmeas.2017.03.027

    Abstract: This paper aims to evaluate the performance of the commercial OSL Landauer InLight System to be applied in dosimetric measurements in a Volumetric Modulated Arc (VMAT) brain tumor planning treatment using a Stereotactic End-To-End Verification Phantom Patient (STEEV™ – CIRS), comparing its results with CaSO4:Dy TLD pellets manufactured and marketed by the Laboratory of Dosimetric Materials/IPEN, PTW PinPoint™ ion chamber and Eclipse 10.0 planning system. The results of commercial InLight™ System using the nanoDot dosimeters showed good reproducibility and stability in both laboratory and clinical measurements. The experimental dose values obtained by all dosimetric techniques varied less than ±1.0% from prescribed by Eclipse 10.0. The intrinsic precision and uncertainty of the OSL reading device were found fair enough, providing good experimental results for VMAT dosimetry.


  • IPEN-DOC 24306

    ANTONIO, PATRICIA L. ; CALDAS, LINDA V.E. . Applying the TSEE technique to Spectrolite and Opal pellets irradiated with high doses of gamma radiation. Radiation Measurements, v. 106, n. SI, p. 538-542, 2017. DOI: 10.1016/j.radmeas.2017.04.014

    Abstract: Spectrolite + Teflon and Opal + Teflon pellets were studied in this work in relation to their dosimetric properties, using the thermally stimulated exoelectron emission (TSEE) phenomenon. The purpose of this work was to study these materials to be used in high-dose dosimetry of Co-60 irradiators, which are employed for several industrial applications. The basic physical principle of this technique is the emission of low energy electrons from the surface of different crystalS. For this reason, it is very employed in work with specially radiation sources of low penetrating power, as alpha and beta radiation, but also with gamma sources. Both materials had already their dosimettic chatacteristics verified in previous works after exposure to high doses of a Co-60 source and measurements by means of thermoluminescence (TL) and optically stimulated luminescence (OSL) techniques. The TSEE response was investigated in terms of the following tests: TSEE emission curves, reproducibility, minimum detectable doses and dose-response curves.

    Palavras-Chave: cobalt 60; crystals; dosimetry; exoelectrons; gamma radiation; gamma sources; irradiation; opals; pellets; radiation doses; silicates; teflon; thermoluminescence


  • IPEN-DOC 27171

    FONTES, E.H. ; NANDENHA, J. ; SOUZA, R.F.B. de ; ANTONIO, F.C.T.; HOMEM-DE-MELLO, P.; NETO, A.O. . Au core stabilizes CO adsorption onto Pd leading to CO2 production. Materials Today Advances, v. 6, p. 1-9, 2020. DOI: 10.1016/j.mtadv.2020.100070

    Abstract: Au core and Pd shell supported on carbon structure Au@Pd/C can cleave the CeC bond of ethanol molecules leading to the production of a relatively high amount of CO2 when compared with Pd/C electrocatalyst as the attenuated total reflectance - Fourier transform infrared (ATR-FTIR) experiment shows. Density functional theory (DFT) calculations showed that this could be explained by the oxidation of CO species adsorbed into Pd sites that has a modified electronic structure compared with Pd/C. In terms of DFT analysis, the highest thermodynamical stability of CO in Pd shell with Au core atoms, when compared with Pd/C is because of the increase of virtual orbital states near Fermi level that can be occupied by valence electrons of CO molecule. The d-band center shift is experimentally verified using the valence band X-ray photoelectron spectroscopy and theoretically predicted by the Generalized Koopmans’ Theorem. Besides that, Au@Pd/C electrocatalyst has a better electrochemical activity when compared with Pd/C.

    Palavras-Chave: ethanol; oxidation; calculation methods; density; nanoparticles; adsorption; carbon dioxide; density functional method


  • IPEN-DOC 23195

    SANTOS, W.S. ; NEVES, L.P.; PERINI, A.P.; BELINATO, W.; MAIA, A.F.; CALDAS, L.V.E. . Avaliação das exposições dos envolvidos em procedimentos intervencionistas usando método Monte Carlo. Brazilian Journal of Radiation Sciences, v. 5, n. 1, p. 01-06, 2017.

    Abstract: Neste estudo apresenta-se um modelo computacional de exposição de um paciente, médico cardiologista e de uma enfermeira em um cenário típico de procedimentos intervencionistas cardíacos. Neste caso, foi calculado um conjunto de coeficientes de conversão (CC) para dose efetiva (E) em termos do produto kerma-área (PKA) para os indivíduos envolvidos, utilizando sete espectros energéticos diferentes e oito projeções de feixe. Também foi calculado o CC para dose de entrada na pele (DEP) do paciente normalizado pelo PKA. Todos os indivíduos foram representados por simuladores antropomórficos computacionais incorporados em um código de transporte de radiação baseado em simulação de Monte Carlo.

    Palavras-Chave: air; conversion; dosimetry; kerma; monte carlo method; occupational exposure; patients; phantoms; radiation doses; radiation protection; radiology; radiological personnel


  • IPEN-DOC 23196

    SANTOS, S.C. ; RODRIGUES JUNIOR, O. ; CAMPOS, L.L. . Bio-prototyping of europium-yttria based rods for radiation dosimetry. Materials Chemistry and Physics, v. 199, p. 557-566, 2017. DOI: 10.1016/j.matchemphys.2017.07.063

    Abstract: The application of solid state dosimeters in radiation protection has grown significantly as consequence of advances in the development of dosimetric materials using rare earths. The conception of new dosimetric materials concerns synthesis methods, which control the evolution of material structure, including further processing steps as, shaping, drying, and sintering. The present study reports a full bio-prototyping approach to produce europium doped yttria rods with potential application in radiation dosimetry. Ceramic particles synthesized by hydrothermal route were characterized by Photon Correlation Spectroscopy (PCS), X-ray diffraction (XRD), and Scanning Electron Microscopy (SEM). The effect of europium on promoting electronic defects in yttria host was evaluated by Electron Paramagnetic Resonance (EPR). Low pressure hydrothermal synthesis led to formation of rounded particles with mean diameter of 410 nm. Aqueous suspensions with 20 vol% of particles prepared at pH 10, and 0.2 wt% binder exhibited apparent viscosity of 213 mPa s, being suitable for bio-prototyping of rods. Sintering of shaped samples at 1600 degrees C for 4 h provided formation of dense ceramic rods. Europium-yttria rods containing 5 at.% Eu exhibited the most intense EPR response.


  • IPEN-DOC 25112

    MARIANO, DOUGLAS O.C.; MESSIAS, MARCELA Di G. ; PREZOTTO-NETO, JOSE P. ; SPENCER, PATRICK J. ; PIMENTA, DANIEL C.. Biochemical analyses of proteins from duttaphrynus melanostictus (Bufo melanostictus) skin secretion: soluble protein retrieval from a viscous matrix by ion-exchange batch sample preparation. Protein Journal, v. 37, n. 4, p. 380-389, 2018. DOI: 10.1007/s10930-018-9780-z

    Abstract: A crucial step in scientific analysis can be sample preparation, and its importance increases in the same rate as the sensitivity of the following employed/desired analytical technique does. The need to analyze complex, viscous matrices is not new, and diverse approaches have been employed, with different success rates depending on the intended molecules. Solid-phase extraction, for example, has been successfully used in sample preparation for organic molecules and peptides. However, due to the usual methodological conditions, biologically active proteins are not successfully retrieved by this technique, resulting in a low rate of protein identification reported for the viscous amphibian skin secretion. Here we describe an ion-exchange batch processing sample preparation technique that allows viscous or adhesive materials (as some amphibian skin secretions) to be further processed by classical liquid chromatography approaches. According to our protocol, samples were allowed to equilibrate with a specific resin that was washed with appropriated buffers in order to yield the soluble protein fraction. In order to show the efficiency of our methodology, we have compared our results to classically prepared skin secretion, i.e., by means of filtration and centrifugation. After batch sample preparation, we were able to obtain reproductive resolved protein chromatographic profiles, as revealed by SDS-PAGE, and retrieve some biological activities, namely, hydrolases belonging to serine peptidase family. Not only that, but also the unbound fraction was rich in low molecular mass molecules, such as alkaloids and steroids, making this sample preparation technique also suitable for the enrichment of such molecules.

    Palavras-Chave: chromatography; ion exchange chromatography; animal tissues; secretion; skin; sample preparation; viscosity; amphibians; hydrolases


  • IPEN-DOC 27156

    AZEVEDO, LUCIANA C. de ; ROVANI, SUZIMARA ; SANTOS, JONNATAN J.; DIAS, DJALMA B. ; NASCIMENTO, SANDI S.; OLIVEIRA, FABIO F.; SILVA, LEONARDO G.A. ; FUNGARO, DENISE A. . Biodegradable films derived from corn and potato starch and study of the effect of silicate extracted from sugarcane waste ash. ACS Applied Polymer Materials, v. 2, n. 6, p. 2160-2169, 2020. DOI: 10.1021/acsapm.0c00124

    Abstract: The growing concern with the amount of plastic materials found in the oceans makes it necessary to develop biodegradable materials that have low toxicity to marine animals and humans, but at the same time are resistant to the actions of microorganisms such as fungi or bacteria. On the other hand, agricultural waste rich in inorganic materials (such as silica) is often discarded, while it could be reused as a source of raw material. Considering these points, sodium silicate solution extracted from sugarcane waste ash was utilized to prepare biodegradable bioplastics based on corn starch and potato starch. The starch-based bioplastics were produced by casting and characterized by several physical-chemical techniques evaluating tensile strength, elongation at break, color analyses, transparency, opacity, moisture, and biodegradation assay. Bioplastics prepared with corn starch presented better physical, mechanical, and thermal properties and optical quality than bioplastics based on potato starch. The samples called CS3 and PS3, with 5.0% glycerol, were the most resistant to tensile strengths of 0.73 and 0.36 MPa, respectively. On the other hand, the highest elongation at break values were found for the samples with 7.5% glycerol (CS9, 52.90% and PS9, 49.33%). Corn starch-based bioplastics were more thermally resistant (CS3, 152.86 °C and CS9, 135.20 °C) when compared to potato starch-based bioplastics (PS3, 140.39 °C and PS9, 127.57 °C). In general, the addition of sodium silicate solution improved the mechanical and thermal properties of both types of bioplastics. The potato starch-based bioplastics were biodegraded in 5 days, while those made from corn starch took almost 40 days. The inclusion of sodium silicate inhibited fungal growth for both corn starch and potato starch bioplastics. The results suggest that sodium silicate solution obtained from renewable sources can be incorporated into starch-based bioplastics for production of biodegradable packaging with antifungal activity.

    Palavras-Chave: biodegradation; agriculture; sugar cane; agricultural wastes; bagasse; chemical composition; ashes; maize; potatoes; starch; plastics; sustainability; sodium silicates; environment; polymers


  • IPEN-DOC 23165

    FEITOSA, SABRINA A.; LIMA, NELSON B. ; YOSHITO, WALTER K. ; CAMPOS, FERNANDA; BOTTINO, MARCO A.; VALANDRO, LUIZ F.; BOTTINO, MARCO C.. Bonding strategies to full-contour zirconia: Zirconia pretreatment with piranha solution, glaze and airborne-particle abrasion. International Journal of Adhesion and Adhesives, v. 77, p. 151-156, 2017. DOI: 10.1016/j.ijadhadh.2017.05.007

    Abstract: This study aimed to evaluate the effect of various zirconia surface pretreatments on the adhesion between full contour 3Y-TZP zirconia and glaze, and the shear bond strength (SBS) between glazed/3Y-TZP and resin cement. Specimens were allocated into groups: GL-glaze; AL+GL-sandblasting with Al2O3+GL; CJ+GL-tribochemical silica coating (Cojet (R)/CJ) + GL; PS+GL-piranha solution+GL; and CJ. Adhesion between 3Y-TZP and GL was evaluated using the scratch test. Surface topography and glaze thickness were evaluated by using a scanning electron microscope (SEM). For SBS, glazed/3Y-TZP surface was etched with hydrofluoric acid and a silane was applied. For CJ only the silane was applied. Samples were tested after 24 h (24 h wet) or after 15,000 thermal cycles and 90 days storage (thermocycled). After SBS, the type of failure was classified as: adhesive, mixed or cohesive. The data were analyzed using two-way ANOVA and Tukey's test. SEM analysis after scratch test revealed circular cracks in the GL group and conformal cracks in the others groups. SEM micrographs suggested that zirconia specimens submitted to airborne-particle abrasion presents rougher and porous surface when compared to surfaces treated with GL and PS. The glaze layer was approximately 1.86 mu m thick in all groups. After 24 h, SBS test showed highest values for AL + GL and CJ + GL and were significantly higher when compared to the GL group. Differences were not significant between PS + GL and the other groups. After aging (thermo-cycling + storage), groups GL and CJ presented no statistically significant difference compared to 24 h and aged AL+GL, CJ+GL and PS + GL groups. The predominant type of failure was mixed. 3Y-TZP surface treatment with glaze application could be considered as an alternative treatment, since it yielded a similar resin bond strength without the need for airborne-particle abrasion.


  • IPEN-DOC 27384

    COUTO, VERONICA M.; OLIVEIRA-NASCIMENTO, LAURA de; CABEÇA, LUIZ F.; GERALDES, DANILO C.; COSTA, JULIANA S.R.; RISKE, KARIN A.; FRANZ-MONTAN, MICHELLE; YOKAYCHIYA, FABIANO ; FRANCO, MARGARETH K.K.D. ; PAULA, ENEIDA de. Capsaicin-cyclodextrin complex enhances mepivacaine targeting and improves local anesthesia in inflamed tissues. International Journal of Molecular Sciences, v. 21, n. 16, p. 1-18, 2020. DOI: 10.3390/ijms21165741

    Abstract: Acidic environments, such as in inflamed tissues, favor the charged form of local anesthetics (LA). Hence, these drugs show less cell permeation and diminished potency. Since the analgesic capsaicin (CAP) triggers opening of the TRPV1 receptor pore, its combination with LAs could result in better uptake and improved anesthesia. We tested the above hypothesis and report here for the first time the analgesia effect of a two-drug combination (LA and CAP) on an inflamed tissue. First, CAP solubility increased up to 20 times with hydroxypropyl-beta-cyclodextrin (HP-β-CD), as shown by the phase solubility study. The resulting complex (HP-β-CD-CAP) showed 1:1 stoichiometry and high association constant, according to phase-solubility diagrams and isothermal titration calorimetry data. The inclusion complex formation was also confirmed and characterized by differential scanning calorimetry (DSC), X-ray diffraction, and 1H-NMR. The freeze-dried complex showed physicochemical stability for at least 12 months. To test in vivo performance, we used a pain model based on mouse paw edema. Results showed that 2% mepivacaine injection failed to anesthetize mice inflamed paw, but its combination with complexed CAP resulted in pain control up to 45 min. These promising results encourages deeper research of CAP as an adjuvant for anesthesia in inflamed tissues and cyclodextrin as a solubilizing agent for targeting molecules in drug delivery.

    Palavras-Chave: anesthesia; inflammation; anesthetics; dextrin; scanning electron microscopy; differential thermal analysis; calorimetry


  • IPEN-DOC 27367

    LITVAC, D. ; CALDAS, L.V.E. . Caracterização dosimétrica do LiF-NRPB para calibração de aplicadores clínicos de betaterapia. Brazilian Journal of Radiation Sciences, v. 8, n. 1, p. 1-15, 2020. DOI: 10.15392/bjrs.v8i1A.1087

    Abstract: A National Radiological Protection Board era uma instituição que trabalhava com radioproteção pessoal e utilizava materiais dosimétricos de LiF. Um destes materiais, empregado antigamente na rotina de trabalho da instituição, consiste de uma placa de liga de alumínio, onde dois discos de politetrafluoroetileno carregados com fluoreto de lítio são retidos por anéis de alumínio. São oficializados, no Sistema Único de Saúde, procedimentos radioterápicos em betaterapia dérmica, betaterapia oftalmológica e betaterapia para profilaxia de pterígio. Na norma NN 3.01, “Diretrizes Básicas de Proteção Radiológica”, exige-se a calibração regular destes aplicadores. O objetivo deste trabalho foi caracterizar dosimetricamente as amostras de LiF-NRPB, verificar se são adequadas para utilização em um sistema para calibrações de aplicadores clínicos de betaterapia e identificar se há a possibilidade de novas aplicações dosimétricas.

    Palavras-Chave: angular correlation; beta particles; calibration; dose rates; dose-response relationships; dosimetry; lithium fluorides; microwave ovens; strontium 90; thermoluminescence; yttrium 90


  • IPEN-DOC 26864

    PARDO DIAZ, C.A.; SHIMOKAWA, C.A.K.; SAMPAIO, C.S.; FREITAS, A.Z. ; TURBINO, M.L.. Characterization and comparative analysis of voids in class II composite resin restorations by optical coherence tomography. Operative Dentistry, v. 45, n. 1, p. 71-79, 2020. DOI: 10.2341/18-290-L

    Abstract: Purpose: This study aimed to characterize and analyze the number of voids and the percentage of void volume within and between the layers of class II composite restorations made using the bulk fill technique or the incremental technique by optical coherence tomography (OCT). Methods and Materials: Class II cavities (43432 mm) were prepared in 48 human third molars (n=24 restorations per group, two class II cavities per tooth). Teeth were divided into four groups and restored as follows: group 1 (FOB), bulk filled in a single increment using Filtek One Bulk Fill (3M Oral Care); group 2 (FXT), incrementally filled using four oblique layers of Filtek Z350 XT (3M Oral Care); group 3 (FBF+FXT), bulk filled in a single increment using Filtek Bulk Fill Flowable Restorative (3M Oral Care) covered with two oblique layers of Filtek Z350 XT (3M Oral Care), and group 4 (FF+FXT), incrementally filled using Filtek Z350 XT Flow (3M Oral Care) covered with two oblique layers of Filtek Z350 XT (3M Oral Care). After the restorative procedure, specimens were immersed into distilled water and stored in a hot-air oven at 378C. Forty-eight hours later, thermal cycling was conducted (5000 cycles, 58C to 558C). Afterward, OCT was used to detect the existence of voids and to calculate the number of voids and percentage of voids volume within each restoration. Data were submitted to chi-square and Kruskal- Wallis tests (a=0.05). Comparisons were made using the Dunn method. Results: Voids were detected in all groups, ranging from 0.000002 (FBF+FXT and FF+FXT) to 0.32 mm3 (FBF+FXT). FF + FXT presented voids in all of the restorations and had a significantly higher number of voids per restoration when compared to the other groups (p,0.05), but restorations with the presence of voids were significantly higher only when compared to FXT (p,0.05). FBF + FXT presented a significantly higher percentage of voids volume than that of FXT (p,0.05). When comparing restorations made using high-viscosity resin-based composites (FOB and FXT), no significant differences regarding number of voids or percentage of voids volume were detected (p 0.05). Conclusions: The use of flowable resin-based composites can result in an increased number of voids and percentage of voids volume in restorations, and this appears to be more related to voids present inside the syringe of the material than to the use of incremental or bulk fill restorative techniques.

    Palavras-Chave: dentistry; resins; biological recovery; tomography; optical equipment; images; composite materials; voids; layers


A pesquisa no RD utiliza os recursos de busca da maioria das bases de dados. No entanto algumas dicas podem auxiliar para obter um resultado mais pertinente.

É possível efetuar a busca de um autor ou um termo em todo o RD, por meio do Buscar no Repositório , isto é, o termo solicitado será localizado em qualquer campo do RD. No entanto esse tipo de pesquisa não é recomendada a não ser que se deseje um resultado amplo e generalizado.

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

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

A opção Busca avançada utiliza os conectores da lógica boleana, é o melhor recurso para combinar chaves de busca e obter documentos relevantes à sua pesquisa, utilize os filtros apresentados na caixa de seleção para refinar o resultado de busca. Pode-se adicionar vários filtros a uma mesma busca.


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

Autor: Maprelian

Título: loss of coolant

Tipo de publicação: Texto completo de evento

Ano de publicação: 2015

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

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

Ao efetuar a busca por um autor o RD apresentará uma relação de todos os trabalhos depositados no RD. No lado direito da tela são apresentados os coautores com o número de trabalhos produzidos em conjunto bem como os assuntos abordados e os respectivos anos de publicação agrupados.

O RD disponibiliza um quadro estatístico de produtividade, onde é possível visualizar o número dos trabalhos agrupados por tipo de coleção, a medida que estão sendo depositados no RD.

Na página inicial nas referências são sinalizados todos os autores IPEN, ao clicar nesse símbolo será aberta uma nova página correspondente à aquele autor – trata-se da página do pesquisador.

Na página do pesquisador, é possível verificar, as variações do nome, a relação de todos os trabalhos com texto completo bem como um quadro resumo numérico; há links para o Currículo Lattes e o Google Acadêmico ( quando esse for informado).



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.