Showing papers by "National Nuclear Energy Commission published in 1997"
TL;DR: In this article, the authors address the mercury exposure scenarios through fish consumption in the urban area of Alta Floresta, by comparing the different patterns of mercury exposure from fish ingestion for different population groups.
43 citations
TL;DR: The isocratic reversed-phase high-performance liquid chromatography method provides a complete picture, within 24 h from the beginning of the fermentation process, of the recombinant protein being produced with respect to its activity, identity, yield, and hGH-related contaminants.
37 citations
TL;DR: Instrumental neutron activation analysis has been applied to analyze epiphytic specimens of the lichen Canoparmelia texana as discussed by the authors, and the accuracy of the method was evaluated by analyzing NIST 1572a Citrus I_eaves, IAEA 336 Lichen and USGS W-1 Rock reference materials.
Abstract: Instrumental neutron activation analysis has been applied to analyze epiphytic specimens of the lichen Canoparmelia texana. Samples collected from the barks of the trees were previously cleaned, lyophilized and ground to be irradiated under a thermal neutron flux in the IEA-RI nuclear reactor. Elements A1, As, Br, Ca, Cd, C1, Co, Cr, Cs, Fe, Hf, K, La, Ce, Nd, Sin, Eu, rib, Yb, Lu, Mg, Mn, Na, Rb, Sb, Sc, Se, Th, Ti, U, V and Zn were determined quantitatively by using short arid long irradiations. Comparisons were made between the results for washed and unwashed samples as well as those collected in two different years, from individual palm trees and also from differelat sites of Sgo Paulo State. The precision and the accuracy of the method were evaluated by analyzing NIST 1572a Citrus I_eaves, IAEA 336 Lichen and USGS W-1 Rock reference materials.
29 citations
TL;DR: In this paper, the authors used the digital neutron radiography (NR) technique to visualize cracks in concrete, which were obtained by the direct method with a gadolinium converter screen and the facility is installed at the radial beam tube of the IEA-R1 Nuclear Research Reactor, which provides a neutron flux of around 3 × 106n s−1 cm−2 at the sample irradiation position.
26 citations
TL;DR: In this paper, a method for determining 210Po in marine samples by wet dissolution, deposition onto silver disc and counting by α-spectrometry was described, and 210Po levels in fish from the Brazilian coast and sediments from Antarctic region were determined.
Abstract: A method for determining210Po in marine samples by wet dissolution, deposition onto silver disc and counting by α-spectrometry is described. Recovery of polonium was obtained with208Po tracer.210Po levels in fish from the Brazilian coast and sediments from Antarctic region were determined. Levels in fish ranged from 0.5 to 5.3 Bq·kg−1 wet and for sediments, mean values of 10 mBq·kg−1 were obtained.
23 citations
TL;DR: In this article, a trabalho sao apresentados valores de concentracao for os elementos minerais Ca, Fe, Κ, Mn, Na, Se e Zn em alimentos convencionais e nao convencions da regiao Amazonica, obtidos por analise por ativacao neutronica instrumental.
Abstract: No presente trabalho sao apresentados valores de concentracao para os elementos minerais Ca, Fe, Κ, Mn, Na, Se e Zn em alimentos convencionais e nao convencionais da regiao Amazonica, obtidos por analise por ativacao neutronica instrumental. As concentracoes dos elementos minerais nos alimentos analisados, variaram, sendo que o potassio se sobressaiu com teores expressivos na jaca (caroco e polpa) e graviola. Dentre os minerais, o selenio foi o que apresentou menor concentracao nos alimentos analisados. Entretanto, notadamente importantes foram as concentracoes verificadas na graviola, pupunha fruto e palmito. De acordo com os resultados obtidos sugere-se a indicacao dos mesmos na alimentacao diaria dos amazonenses e espera-se contribuir na elaboracao de tabelas de composicao de alimentos regional e nacional.
13 citations
TL;DR: In this paper, the electrical resistivity during sintering decreases from 4 to 6 orders of magnitude in the 400-1500 K temperature range depending on the amount of CoO added to the SnO2 lattice.
11 citations
TL;DR: In this paper, the thermal neutron capture cross sections of 48 Ti, 51 V, 50,52,53 Cr and 58,60,62,64 NI were re-estimated using recent data on the thermal neutrase capture cross-section of the 14 N.
10 citations
TL;DR: In this paper, a reversed-phase partition system is used to separate and detect all rare earth elements with good reproducibility and sensitivity, which can be used in routine quality control procedure.
10 citations
TL;DR: A preparation method of immobilized urease discs by an electron beam irradiation technique was developed, and the relationship between enzyme activity and preparation conditions was investigated.
8 citations
TL;DR: In this article, the authors used finite element method and mathematical programming to obtain not only the limit load but also an estimate of the elastoplastic displacements, which is very useful because construction codes usually impose limits on the electroplastic displacement.
TL;DR: In this paper, the structure and frequency domain methods for soil-structure interaction are addressed, and an example of soilstructure analysis with frequency-dependent soil properties is given and examples of identification of foundation impedance functions and soil properties are presented.
TL;DR: An immunoradiometric assay (IRMA) of human thyrotropin (hTSH), based on magnetic solid phase separation, was studied especially in terms of its nonspecific bindings which were identified as a product of the interaction between an altered form of radioiodinated anti-h TSH monoclonal antibody and the uncoupled magnetizable cellulose particle (matrix).
Abstract: An immunoradiometric assay (IRMA) of human thyrotropin (hTSH), based on magnetic solid phase separation, was studied especially in terms of its nonspecific bindings (B0) which were identified as a product of the interaction between an altered form of radioiodinated anti-hTSH monoclonal antibody (125I-mAB) and the uncoupled magnetizable cellulose particle (matrix). Preincubation with the same matrix, solid phase saturation with milk proteins, tracer storage at 4 degrees C and serum addition during incubation were found to be particularly effective in preventing their formation. These findings were used to reproducibly decrease nonspecific bindings to values < 0.1% (or < 70 cpm), thus increasing the signal-to-noise ratio (B60/B0) up to values of 300-500. This way hTSH radioassays were obtained with functional sensitivities of about 0.05 mIU/L and analytical sensitivities of the order of 0.02 mIU/L. Such sensitivities, and, more importantly, a general improvement in assay performance, were obtained in a highly reproducible manner and all over the useful tracer life.
20 Mar 1997
TL;DR: In this paper, the apparent stain versus temperature curves for two kind of strain gages are determined and a comparison of the behavior of the two types of gages is presented, as well as the results of measurements of these gages.
Abstract: The scope of this work is to determine the apparent stain versus temperature curves for two kind of strain gages. Measurement results of these strain gages as well as a comparison of the behavior of both are presented.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
TL;DR: In this article, the Ductile Fracture Method (DFM) is examined in conjunction with the Common Format Equation (CFE) proposed by Donoso and Landes. But, it will be shown here that using the CFE approach with an adequate normalizing parameter for the deformation function, H.
Abstract: — The Ductile Fracture Method (DFM) proposed by Ernst and Landes and further developed by Landes and coworkers is examined in conjunction with the Common Format Equation (CFE) proposed by Donoso and Landes. The DFM can be used to predict the load versus displacement behavior for a structure from the load versus displacement record for a fracture toughness test specimen. This involves a calibration function transformation procedure which is often laborious. But, it will be shown here that using the CFE approach with an adequate normalizing parameter for the deformation function, H, the transformation procedure can be virtually eliminated. As a consequence, the predictions done by the DFM can be completed in a shorter time. The equations which originated the CFE approach are reviewed to show that the modification proposed in this paper is necessary for H to get closer to a unique representation, independent of the geometry. Some examples are presented to demonstrate the applicability of the approach.
TL;DR: In this paper, the authors used the OCEANet to simulate the surface water contamination caused by routine or accidental radionuclide releases in the North Sea near to Sellafield and adjacent areas.
Abstract: The137Cs radionuclide dispersion in the marine environment through the compartmental model is reported. The model simulates the surface water contamination caused by routine or accidental radionuclide releases. For the simulation the OCEAN program was applied in the North Sea, near to Sellafield and adjacent areas, based on published transfer coefficient data. The results are in good agreement with the literature and the model developed can be applied to the brazilian coastal regions.
TL;DR: An inventory of 137Cs in the sediments of Rochedo Reservoir showed that 94 GBq reached the Meia Ponte River system, as a consequence of the Goiânia radiological accident in 1987 as mentioned in this paper.
Abstract: An inventory of 137Cs in the sediments of Rochedo Reservoir showed that 94 GBq reached the Meia Ponte River system, as a consequence of the Goiânia radiological accident in 1987.137Cs profile shapes were dictated by their location relative to the main river inflow. When NH4 concentrations in the sediment were high there was a clear correlation between Kd and NH4. Laboratory experiments showed that the efficiency of 137Cs desorption from the sediment, was a function of the illite content.
TL;DR: In this paper, the authors applied neutron activation analysis to analyze the geological standard materials: GSP-1 and W1 from USGS, GB-1 from the University of Bahia, Brazil and a sample of uraniferous rock.
Abstract: In this work, neutron activation analysis was applied to analyze the geological standard materials: GSP-1 and W-1 from USGS, GB-1 and BB-1 from the University of Bahia, Brazil and a sample of uraniferous rock. Hf was determined by instrumental method and the obtained results was shown with relative standard deviations varying from 1.1 to 14%. In the case of Zr analyses, both instrumental and radiochemical neutron activation analyses were used. The interference of154Eu radioisotope that emits γ-rays too close to those emitted by95Zr was eliminated by retention of Zr in an anionic exchange resin column. The contribution of uranium fission product was considered in the Zr determination by using an interference factor. Results of Zr were presented with relative standard deviations varying from 2.0 to 25.7%. More precise results were obtained by using radiochemical separation. The concentration obtained for Hf and Zr in reference materials agreed well with respective certified values or information values.
TL;DR: A simple procedure for the labeling of N-acetylcysteine with 99mTc and the results of optimization of the labeling procedure are described, finding the radiochemical yield to be greater than 98%, with good reproducibility.
20 Mar 1997
TL;DR: In this article, a software SIMFOT has been used to generate isochromatics for some birefringent models and it was improved in order to simulate isochromeatics in an infinite plate with a single elliptical hole.
Abstract: A software SIMFOT has been used to generate isochromatics for some birefringent models. It was improved in order to simulate isochromatics in an infinite plate with a single elliptical hole. Stresses are applied at far boundaries of this plate in the direction of the ellipse minor axis. This minor dimension can be changed as necessary to approximate a line crack by a thin elliptical hole. Images from this plate are compared with images from an infinite plate with a singular circular hole and presents good agreement when the relation minor axis/major axis approaches one. Formulas for the whole stress field in a direct way to be implemented in computer are presented in this paper.
27 Jan 1997
TL;DR: In this paper, the growth and laser performances of LiYF4 and LiGdF4, pumped by a diode-laser (4W), are described, and the laser emission cross-section of the Nd:LiGd F4 is determined to be in the order of 8×10−20 cm2.
Abstract: The growth and laser performances of Nd:LiYF4 and Nd:LiGdF4, pumped by diode-laser (4W), are described. The laser emission cross-section of the Nd:LiGdF4 was determined to be in the order of 8×10−20 cm2.
TL;DR: In this article, a trabalho utiliza tecnica de processamento digital de imagens for a obtencao das distribuicoes de orientacao de particulas em aglomerados bidimensionais simulados.
Abstract: Na formacao de aglomerados, particulas pequenas tendem a se agregar, reduzindo a energia livre total do sistema. Mesmo quando as particulas primarias tem forma esferica e tamanhos uniformes, dependendo do tipo do processamento e das forcas envolvidas, os aglomerados podem apresentar orientacoes preferenciais de particulas. Este trabalho utiliza tecnica de processamento digital de imagens para a obtencao das distribuicoes de orientacao de particulas em aglomerados bidimensionais simulados. As simulacoes foram realizadas em um ambiente de computacao grafica com recursos de modelagem de solidos. A escolha de modelos bidimensionais para representar casos tridimensionais e um artificio muito empregado para reduzir os altos tempos de processamento computacional envolvidos no estudo de processos complexos.Apesar de simples, em principio, muitas conclusoes importante podem ser extraidas dos modelos bidimensionais e muitos de seus resultados aplicados diretamente aos casos reais.