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Sample records for activation analysis determinacao

  1. Application of activation analysis for determination of some elements in cassiterite samples; Aplicacao da analise por ativacao para a determinacao de alguns elementos em amostras de cassiterita

    Armelin, Maria Jose Aguirre

    1978-07-01

    This work consists in the development of an analytical method using activation by thermal neutrons for the determination of some minor elements and traces present in cassiterite (tin ore). This method was then applied to determine these elements in samples of cassiterite from different regions of Brazil. An analysis was made of the mineralogy characteristic of cassiterite as well as of the minerals most commonly associated with it. Four main types of interference were found to occur in the analysis by activation of trace elements in samples of cassiterite. The method involves the analysis without chemical separation for the determination of some elements and the analysis with chemical separation for the determination of other elements. The steps involved in both types of analysis are described. In the analysis with chemical separation the matrix element (tin) is separated by distillation in an H{sub 2}SO{sub 4}-HBr medium, after fusion of the ore with Na{sub 2}O{sub 2}. Arsine and antimony are determined in the distilled, whereas some lanthanide elements and uranium are determined in the distillation residue by separating them as a group by precipitation with lanthanum fluoride. A discussion on the precision, accuracy and sensibility of the method is also included. (author)

  2. Determination of Rare Earth Elements in plants by neutron activation analysis; Determinacao de elementos terras raras em plantas por analise por ativacao com neutrons

    Figueiredo, Ana M.G.; Maria, Sheila P. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil); Ceccantini, Gregorio C.T. [Sao Paulo Univ., SP (Brazil). Inst. de Biociencias

    1996-07-01

    In the present work, instrumental neutron activation analysis was employed to the determination of rare earth elements (La, Ce, Nd, Eu, Tb, Yb e Lu) in plants, aiming biogeochemical studies. The precision and accuracy of the method were verified by the analysis of the reference materials Citrus Leaves (NIST 1572) and Pine Needles (NIST 1575). With exception of terbium, the results obtained agreed with reference values, giving relative errors less than 25%. The method was applied to different species of plants growing in the alkaline-ultramafic complex of Salitre, MG and the obtained data were compared to the average content in plants. (author)

  3. Trace element determination study in human hair by neutron activation analysis; Estudo da determinacao de elementos traco em cabelos humanos pelo metodo de analise por ativacao com neutrons

    Frazao, Selma Violato

    2008-07-01

    Human hair analysis studies have been subject of continuous interest due to the fact that they can be used as an important tool to evaluate trace element levels in the human body. These determinations have been carried out to use hair for environmental and occupational monitoring, to identify intoxication or poisoning by toxic metals, to assess nutritional status, to diagnose and to prevent diseases and in forensic sciences. Although hair analysis presents several advantages over other human tissue or fluid analyses, such as organ tissue, blood, urine and saliva, there are some controversies regarding the use of hair analysis data. These controversies arise from the fact that it is difficult to establish reliable reference values for trace elements in hair. The purpose of this study was to evaluate the factors that affect element concentrations in hair samples from a population considered healthy and residing in the Sao Paulo metropolitan area. The collected human head hair was cut in small pieces, washed, dried and analyzed by neutron activation analysis (NAA). Aliquots of hair samples and synthetic elemental standards were irradiated at the IEA-R1 nuclear research reactor for 16 h under a thermal neutron flux of about 5x10{sup 12} n cm{sup -2} s{sup -1} for As, Br, Ca, Co, Cr, Cs, Cu, Fe, K, La, Na, Sb, Sc, Se and Zn determinations. The induced gamma activities of the standards and samples were measured using a gamma ray spectrometer coupled to an hiperpure Ge detector. For quality control of the results, IAEA- 85 Human Hair and INCT-TL-1 Tea Leaves certified reference materials (CRMs) were analyzed. Results obtained in these CRMs presented for most of elements, good agreement with the values of the certificates (relative errors less than 10%) and good precision (variation coefficients less than 13.6%). Results of replicate hair sample analysis showed good reproducibility indicating homogeneity of the prepared sample. Results obtained in the analyses of dyed and

  4. Determination of uranium fission products interference factors in neutron activation analysis; Determinacao de fatores de interferencia de produtos de fissao de uranio na analise por ativacao neutronica

    Ribeiro Junior, Ibere Souza

    2014-09-01

    Neutron activation analysis is a method used in the determination of several elements in different kinds of matrices. However, when the sample contains high U levels the problem of {sup 235}U fission interference occurs. A way to solve this problem is to perform the correction using the interference factor due to U fission for the radionuclides used on elemental analysis. In this study was determined the interference factor due to U fission for the radioisotopes {sup 141}Ce, {sup 143}Ce, {sup 140}La, {sup 99}Mo, {sup 147}Nd, {sup 153}Sm and {sup 95}Zr in the research nuclear reactor IEA-R1 on IPEN-CNEN/SP. These interference factors were determined experimentally, by irradiation of synthetic standards for 8 hours in a selected position in the reactor, and theoretically, determining the epithermal to neutron fluxes ratio in the same position where synthetic standards were irradiated and using reported nuclear parameters on the literature. The obtained interference factors were compared with values reported by other works. To evaluate the reliability of these factors they were applied in the analysis of studied elements in the certified reference materials NIST 8704 Buffalo River Sediment, IRMM BCR- 667 Estuarine Sediment e IAEA-SL-1 Lake Sediment. (author)

  5. Determination of essential elements in dietetic sample by neutron activation analysis; Determinacao de elementos essenciais em alimentos dieteticos pela tecnica de analise por ativacao com neutrons

    Siquelli, Murilo V.; Maihara, Vera A. Maihara [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Lab. de Analise por Ativacao Neutronica]. E-mail: murilo_siquelli@hotmail.com; vmaihara@ipen.br

    2005-07-01

    In the last years there has been an increase of the dietetic product consumption by people who suffer from diabetes, heart disease and by people concerned about having a healthy life as well. Despite the increase of dietetic product presents in the diet of the Brazilian population, the use of these products is still controversial. The analysis of the nutritional composition of these products is becoming important because a great number of people is changing their traditional food by dietetic products. In the literature, there is no information about the inorganic composition, mainly related to the essential elements, in the dietetic products: diet and light . In this study are presented preliminary results of the concentrations of Br, Ca, Cr, Fe, Na and Zn determined by Instrumental Neutron Activation Analysis in aspartame, saccharin and cyclamate sodium , and stevia based sweetener samples. Gelatin samples, diet and light, were also analyzed. Methodology validation was done analyzing NIST reference materials Tea Leaves (INCT-TL-1) and Mixed Polish Herbs (INCT-MPH-2). (author)

  6. Trace elements determination in human bone tissue by neutron activation analysis; Determinacao de elementos de traco em tecido osseo humano pelo metodo de ativacao com neutrons

    Takata, Marcelo K.; Saiki, Mitiko [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Div. de Radioquimica; Sumita, Nairo M.; Saldiva, Paulo H.N.; Pasqualucci, Carlos A. [Sao Paulo Univ., SP (Brazil). Faculdade de Medicina. Lab. Experimental de Poluicao Atmosferica

    2002-07-01

    Determination of trace elements in human bones is of the great interest for evaluating nutritional state and for prevention, control and study of several diseases caused by mineral or trace element imbalance. In this study, neutron activation analysis (NAA) was applied for trace elements in human rib bone tissue. Elements Ba, Br, Ca, Cl, Fe, K, Mg, Mn, Na, P, Rb, Sr and Zn were determined in total bone tissue and in its subcompartments (cortical and trabecular tissue) separately. Irradiations were performed at IEA-R1 nuclear research reactor of IPEN-CNEN/SP. Short irradiations of 4 minutes were carried out under thermal neutron flux of 4.5x10{sup 11} n cm{sup -2} s{sup -1} and long irradiations of 16 hours under neutron flux of 10{sup 12} n cm{sup -2} s{sup -1}. Results obtained showed a variability between elemental concentrations found for bones from different individuals. A comparative study made between the data obtained for cortical and trabecular bones indicated that these two tissues present different elemental concentrations. Concentrations of Ca, Mg, Na and P obtained for cortical tissue were the same magnitude of those published data. (author)

  7. Essential and toxic element determination in edible mushrooms by neutron activation analysis; Determinacao de elementos essenciais e toxicos em cogumelos comestiveis por analise por ativacao com neutrons

    Moura, Patricia Landim da Costa

    2008-07-01

    In this study concentrations of As, Br, Co, Cr, Cs, Fe, K, Na, Rb, Se and Zn were determined in edible mushrooms acquired from commercial establishments in the city of Sao Paulo and directly from Mogi das Cruzes, Suzano, Juquitiba and Mirandopolis producers. The analytical technique used for determining these elements in edible mushrooms was Instrumental Neutron Activation Analysis (INAA). Species of the Agaricus, Lentinus and Pleurotus genera were acquired during the period from November, 2006 to March, 2007. About 150 to 200 mg of freeze-dried mushrooms were irradiated in a neutron flux of 1012 cm{sup -2} s{sup -1} for 8 hours in the IEA-R1 nuclear research reactor at IPEN-CNEN-SP. In order to evaluate the precision and accuracy of the methodology, four reference materials: INCT-MPH-2 Mixed Polish Herbs and INCT-TL-1 Tea Leaves, NIST SRM 1577b Bovine Liver, and the material Mushroom from IAEA were analyzed. Results showed some variation in the element concentrations among the different genera. In some samples, arsenic was found but in low concentrations. Arsenic is probably derived from the contamination from pesticides used in the cultivation, in their the substrates where mushrooms uptake their nutrients. Although there are element concentration variations, mushrooms can still be considered a very rich nutritional source, mainly because of their low concentrations of Na, and due to the good source of K, Fe and Zn. (author)

  8. Determination of essential elements in edible seaweed by neutron activation analysis; Determinacao de elementos essenciais em algas marinhas comestiveis por analise por ativacao neutronica

    Alves, Cassio Bessa Lima; Maihara, Vera Akiko, E-mail: cassio_man@hotmail.com, E-mail: vmaihara@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Comestible marine algae are gaining wider global trade, not only because of the taste but also the nutritional quality they present. They are rich in protein, fiber, vitamins and are excellent sources of essential elements due to their ability to absorb substances storing them in their bodies. its chemical composition varies according to the species, habitat, maturity and environmental conditions which are submitted. The method of Neutron Activation Analysis was used to determine the essential elements Cl, K, Mg, Mn and Na present in marine algae from different countries, which are sold in the city of Sao Paulo. A total of 6 samples of marine algae were analyzed, 4 species of Nori (Porphyra umbilicates) from China, Korea, Japan and USA; 1 of Hijiki (Hijikia fusiforme) species from Japan; and 1 species of Kombu (Laminaria sp.) of South Korea. To validate the methodology used was the reference material NIST SRM 1577b Bovine Liver. The concentrations range from 5265-1175 μg/g to CL; from 14413-90261 μg/g to K; from 3007-7091 μg/g to Mg; from 2,3-33,8 μg/g to Mn and from 5161-24973 μg/g to Na.

  9. Rare-earth and thorium in soil and manioc: determination using neutron activation analysis; Terras-raras e torio em solo e mandioca: determinacao por ativacao neutronica

    Silva, Lucilene Guerra e [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Faculdade de Farmacia; Menezes, Maria Angela de B.C.; Palmieri, Helena E.L. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil). Servico de Reator e Irradiacoes]. E-mail: menezes@cdtn.br; Nalini Junior, Herminio A. [Ouro Preto Univ., MG (Brazil). Dept. de Geologia; Jacimivic, Radojko [Instituto Josef Stefan, Liubliana (Slovenia). Dept. de Ciencias Ambientais

    2005-07-01

    This paper reports the elements rare-earth and Thorium determined in soil and manioc during an assessment carried out to evaluate the elemental concentration in several matrixes connected with the chain food. One site studied is in the Iron Quadrangle, Minas Gerais, Brazil, that presented mineral exploration activity in the past. Another site is without any mining activity and it is outside the Quadrangle. The objective was to evaluate the influence of a mining activity on the elemental concentration in the soil and manioc is grown around the mining area. The elemental determination was achieved by applying the k{sub 0}-instrumental Neutron Activation. (author)

  10. Manganese determination om minerals by activation analysis, using the californium-252 as a neutron source; Determinacao de manganes em minerios, por analise por ativacao, usando californio-252 como fonte de neutrons

    Cardoso, Antonio

    1976-07-01

    Neutron Activation Analysis, using a Californium-252 neutron source, has been applied for the determination of manganese in ores such as pyrolusite, rodonite (manganese silicate)' and blending used in dry-batteries The favorable nuclear properties of manganese, such as high thermal neutron cross-section for the reaction {sup 55}Mn (n.gamma){sup 56} Mn, high concentration of manganese in the matrix and short half - life of {sup 56}Mn, are an ideal combination for non-destructive analysis of manganese in ores. Samples and standards of manganese dioxide were irradiated for about 20 minutes, followed by a 4 to 15 minutes decay and counted in a single channel pulse-height discrimination using a NaI(Tl) scintillation detector. Counting time was equal to 10 minutes. The interference of nuclear reactions {sup 56}Fe(n,p){sup 56}Mn and {sup 59} Co (n, {alpha}){sup 56} were studied, as well as problems in connection with neutron shadowing during irradiation, gamma-rays attenuation during counting and influence of granulometry of samples. One sample,was also analysed by wet-chemical method (sodium bismuthate) in order to compare results. As a whole, i t was shown that the analytical method of neutron activation for manganese in ores and blending, is a method simple, rapid and with good precision and accuracy. (author)

  11. Drawing up of a procedure for vanadium determination in mussels using the neutron activation analysis method; Estabelecimento de procedimento para determinacao de vanadio em mexilhoes pelo metodo de analise por ativacao com neutrons

    Seo, Daniele, E-mail: danyseo@uol.com.b [Universidade Presbiteriana Mackenzie, Sao Paulo, SP (Brazil). Centro de Ciencias Biologicas e da Saude; Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Vasconcellos, Marina B.A.; Saiki, Mitiko; Catharino, Marilia G.M.; Moreira, Edson G., E-mail: mbvascon@ipen.b, E-mail: mitiko@ipen.b, E-mail: mgcatharino@uol.com.b, E-mail: emoreira@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Sousa, Eduinetty C.P.M. de; Pereira, Camilo D.S., E-mail: edvinett@usp.b, E-mail: camilo.pereira@usp.b [Universidade de Sao Paulo (IO/USP), SP (Brazil). Inst. Oceanografico. Lab. de Ecotoxicologia Marinha

    2009-07-01

    This work establishes an adequate procedure for obtaining reliable results for determination of vanadium in mussels, leg by leg by the neutron activation analysis (NAA), viewing the posterior application on the bio monitoring the coastal pollution, particularly near the petroleum terminals.For the evaluation of result quality concerning to the quality of those results, the work analysed the reference material certification NIST SRM 1566b Oyster Tissue. The precision of the results were also analysed using repetitions of mussel samples collected at the coastal of northern Sao Paulo state, Brazil. The NAA procedure consisted of 200 mg of sample and a synthetic standard of vanadium during a period of 8 s and under a thermal neutron flux of 6.6 x 10{sup 12} n cm{sup -2} s{sup -1} at the pneumatic station 4 of the IEA-R1 nuclear reactor of IPEN-CNEN/SP. After a 3 min decay, the measurements of the gamma activities of the sample and the standard were done using a Ge hyper pure semi-conductor detector, connected to gamma ray multichannel analyser. The vanadium were determined by the measurement of the gamma activity of the {sup 52}V through the 1434.08 keV peak, and half-life time of 3.75 min. The concentration of V were calculated by the comparative method. The obtained results indicated the viability of the NAA procedure established for the determination of vanadium in mussels

  12. Application of neutron activation analysis for the determination of essential elements in egg samples; Aplicacao da analise por ativacao com neutrons para a determinacao de elementos essenciais em amostras de ovos

    Gomes, Bruna G.; Maihara, Vera A.; Avegliano, Roseane P., E-mail: brunagabrielegomes@gmail.com, E-mail: vmaihara@ipen.br, E-mail: pagliaro@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    The eggs are among the twenty foods consumed by the population of the five major regions of Brazil. Among the types of eggs, there are differences in nutritional value, which can vary according to the food of the bird. This study evaluating the elements Cl, K, Mg, Mn and Na considered essential micronutrients in food, because they are fundamental in several metabolic processes necessary for the maintenance and training of the human body. We analyzed three types of eggs: egg whites, of the quail, and the colonial in cooked and raw form, using the Instrumental Neutron Activation Analysis method (INAA). The egg samples were lyophilized and pulverized before analysis. To validate the methodology, reference materials NIST RM 8415 Whole Egg Powder and NIST SRM 1567 Wheat Flour were analyzed. The samples, reference materials and standards of the elements were irradiated for 20 seconds under a thermal neutron flux of 6,6x10{sup 12} cm -2 s -1 in the nuclear research reactor IEA-R1 of IPEN-CNEN / SP. The results were consistent with the values of the Brazilian Table of Food Composition (TACO)

  13. Determination of essential and toxic elements in commercial baby foods by instrumental neutron activation analysis and atomic absorption spectrometry; Determinacao dos elementos essenciais e toxicos em alimentos comerciais infantis por analise por ativacao com neutrons e espectrometria de absorcao atomica

    Vallinoto, Priscila

    2013-08-01

    The World Health Organization recommends that infants should be breast fed exclusively for at least six months after birth. After this period, it is recommended to start introducing complementary foods, in order to meet the child's nutritional, mineral and energy needs. Commercial food products for infants form an important part of the diet for many babies. Thus, it is very important that such food contains sufficient amounts of minerals. Inadequate complementary feeding is a major cause of high rates of infant malnutrition in developing countries. In this study, essential elements: Ca, Cl, Co, Cr, Fe, K, Mg, Mn, Na, Se and Zn and toxic elements: As, Cd, Hg levels were determined in twenty seven different commercial infant food product samples by Instrumental Neutron Activation Analysis (INAA) and Atomic Absorption Spectrometry (AAS). In order to validate both methodologies the reference material: INCT MPH-2 Mixed Polish Herbs and NIST - SRM 1577b Bovine Liver by INAA and NIST - SRM 1548th Typical Diet and NIST - SRM 1547 Peach Leaves by AAS were analyzed. The twenty seven baby food samples were acquired from Sao Paulo city supermarkets and stores. Essential and toxic elements were determined. Most of the essential element concentrations obtained were lower than the World Health Organization requirements, while concentrations of toxic elements were below the tolerable upper limit. These low essential element concentrations in these samples indicate that infants should not be fed only with commercial complementary foods. (author)

  14. Neutron activation analysis for determining of inorganic trace elements in by-products of soybean, cotton, corn, wheat, sorghum and rice; Aplicacao da analise por ativacao com neutrons para determinacao de elementos inorganicos em subprodutos da soja, algodao, milho, trigo, sorgo e arroz

    Teruya, Carla M.; Armelin, Maria Jose [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil); Silva Filho, Jose Cleto [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Ciencias Animais; Silva, Aliomar G. [Empresa Brasileira de Pesquisa Agropecuaria (EMBRAPA), Sao Carlos, SP (Brazil). Centro de Pesquisa de Pecuaria do Sudeste

    1999-11-01

    In the present paper the instrumental neutron activation analysis was applied to determine some essential and toxic elements in six agroindustrial by-products utilized to feed animal. The accuracy of the method was evaluated by means of reference material analysis. In general, the precision of the method was lower than 10% and the accuracy near to 5%. (author) 7 refs., 1 tab.

  15. Determination of Hg and other elements in fish and plant samples from Amazonic region, by neutron activation analysis; Determinacao de Hg e outros elementos de interesse em amostras de peixes e plantas da regiao amazonica, por analise por ativacao com neutrons

    Favaro, Debora I.T.; Vasconcellos, Marina B.A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Supervisao de Radioquimica; Fostier, Anne Helene [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Quimica Analitica

    1996-07-01

    In the present work the region of Serra do Navio, Amapa State, was chosen to asses the Hg contamination due to gold mining activities. As part of monitoring of this region, fishes and plants were collected and analysed by instrumental neutron activation (INAA). Through this method it was possible to determine the concentration of the elements: As, Ca, Cr, Co, Fe, Hg, Rb, Sb, Se and Zn in fishes and Ca, Co, Cr, Fe, Hg, La, Na, Rb, Sb, Sc, Se and Zn in plants. Mercury concentrations found in fishes ranged from 0.64 to 1.11 {mu}/g and from 0.83 to 0.15 {mu}g/g in plants. These results were compared with those obtained by the atomic absorption technique and they agreed well. The accuracy and precision of the INAA method were checked by means of analyses of reference materials. (author)

  16. Multielementar determination by neutron activation in sediment samples from Tartarugalzinho region, Amapa State, Brazil; Determinacao multielementar em amostras de sedimentos da regiao do Tartarugalzinho, Amapa, por ativacao neutronica

    Neri, Maria C.; Favaro, Debora I.T.; Vasconcellos, Marina B.A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil); Oliveira, Sonia M.B. de; Melfi, Adolfo J. [Sao Paulo Univ., SP (Brazil). Inst. de Geociencias; Fostier, Anne H. [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Quimica Analitica; Guimaraes, Jean R.D. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Biofisica; Forti, Maria C. [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil)

    1999-11-01

    In the present work, sediment samples collected in the Tartarugalzinho region, State of Amapa, were analyzed by instrumental neutron activation analysis. The concentration of the elements As, Ba, Br, Co, Cr, Cs, Fe, Na, Rb, Sc, Se, Ta, Th, U, Zn and Zr and the rare earth elements Ce, Eu, La, Lu, Nd, Sm, Tb and Yb could be determined. Analysis of the reference materials Buffalo River Sediment (NIST SRM 2704) and Soil 7 (IAEA) showed the accuracy and precision of the method. (author) 4 refs., 1 fig., 7 tabs.

  17. Determination of micro minerals in phosphorus source fed to animals by activation with neutrons; Determinacao de microminerais em fontes de fosforo fornecidas a animais por ativacao com neutrons

    Armelin, Maria Jose A.; Mori, Clara S. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil); Silva, Jose Cleto da [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil)

    1995-12-31

    Instrumental neutron activation analysis was applied to determine the elements Ca, Co, Cr, Cu, Eu, Fe, K, La, Mg, Mn, Na, P, Sb, Sc and Zn in four phosphatic supplementation samples. analysis of variance, Turkey`s and Sheffe`s test were applied to certify the homogeneity of the sub-samples (200 mg). In general, the precision of the method was lower than 15%. The phosphatic supplementation samples analyzed can be considered adequate to feed into animals in relation to mineral composition. (author). 5 refs., 2 tabs.

  18. Application of neutron activation analysis to the determination of total mercury and other elements of interest in soil and sediment samples from Serra do Navio and Vila Nova River Basin, Amapa, Brazil; Aplicacao do metodo de ativacao neutronica a determinacao do mercurio total e outros elementos de interesse em amostras de solo e sedimento da Serra do Navio e Bacia do Rio Vila Nova, Amapa

    Goncalves, Cristina

    1997-07-01

    In this work it is presented a survey on total mercury determination by a radiochemical method in sediment and soil samples from two regions, in the state of Amapa: Serra do Navio (background area) and Vila Nova river basin (gold mining area). The method consisted in leaching of the irradiated samples with acqua regia in a Parr bomb, and heating in microwave oven, for one minute. Then the solvent extraction technique was applied, using bismuth diethyldithiocarbamate (Bi(DDC){sub 3}) as extractant agent. The organic phase, containing {sup 197}Hg and {sup 203}Hg radioisotopes, was measured in a gamma spectrometer with hyper pure Ge detector. This method eliminated the interference of the 279.54 keV photopeak of {sup 75}Se on 279.2 keV photopeak of {sup 203}Hg, besides improving counting statistics of both Hg radioisotopes. The elements As, Ba, Br, Ce, Co, Cr, Cs, Eu, Fe, Hf, Ho, K, La, Lu, Mg, Mn, Na, Nd, Rb, Sb, Sc, Se, Sm, Ta, Tb, Th, Ti, U, V, W, Yb, Zn and Zr were also determined by the instrumental neutron activation analysis. Two irradiation series were carried out to quantify these elements in soil and sediment samples; a short term irradiation allowed to evaluate Mg, Mn, Na, Ti and V levels, and by long term irradiation, the other elements were determined. Precision and accuracy of radiochemical procedure were verified by means of analysis of the reference materials Buffalo River Sediment and Lake Sediment, for sediments and GXR-5, for soils. For the instrumental analysis, the reference materials Buffalo River Sediment, Soil 7, JB-1 and Oyster Tissue were used. The samples were also submitted to X ray diffraction, in Instituto de Geoscience-USP, to observe mercury behaviour with mineralogy. Aluminium concentration was determined by X ray fluorescence method, in the Department of Materials, IPEN/CNEN-SP, making possible enrichment factor calculation so that mercurial contamination in the gold mining area (Vila Nova river basin) could be evaluated. The mercury

  19. Mineral water {sup 222} Rn activity decrease due to consumption habits; Determinacao do decrescimo da atividade de radonio-222 em aguas minerais simulando habitos de consumo

    Cipriani, Moacir; Taddei, Maria Helena Tirollo; Silva, Nivaldo Carlos da [Comissao Nacional de Energia Nuclear (CNEN), Pocos de Caldas, MG (Brazil). Laboratorio

    2001-07-01

    Mineral waters from the Pocos de Caldas Plateau springs, an elevated region with high natural radioactivity, in the State of Minas Gerais, Brazil, have significant {sup 222} Rn concentration on site. The highest concentration in the waters are from: Fonte Villela - Aguas da Prata ({approx} 1000 Bql{sup -1}); Fonte Grande Hotel - Pocinhos do Rio Verde ({approx} 400 Brq{sup -1}) and Fonte CNEN Lab - Pocos de Caldas ({approx} 290 Bql{sup -1}). These waters are used by the population as drinking water and due to consumption habits, can lead to internal doses above accepted limits for the public. This work deals with the decrease of {sup 222} Rn activity in mineral waters fro two different popular consumption habits, and with the adult effective dose equivalent reduction due to water consumption habits. It has been found that the estimated dose based on the biokinetic Crawford-Brown model, can be one fourth of dose based on {sup 222} Rn activity on site. (author)

  20. Activation analysis

    The neutron activation analysis, which appears to be in limits for further advance, is the most suitable for providing information on the principal as well as the microcomponents in any sample of solid form. Then, instrumental activation analysis is capable of determination of far many elements in various samples. Principally on the neutron activation analysis, the following are described in literature survey from 1982 to middle 1984: bibliography, review, data collection, etc.; problems in spectral analysis and measurement; activation analysis with neutrons; charged particle and photo-nucleus reactions; chemical separation, isotopic dilution activation analysis; molecular activation analysis; standard materials; life and its relation samples; environmental, food, court trial and archaeological samples; space and earth sciences. (Mori, K.)

  1. In vivo determination of the {sup 99m}Tc-MDP incorporated activity in bone tissue; Determinacao in vivo da atividade incorporada de {sup 99m} Tc-MDP no tecido osseo

    Souza, Joseane Fonseca; Braga, Francisco J.H.N. [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras. Dept. de Fisica e Matematica; Dantas, Bernardo M.; Bertelli, Luiz [Instituto de Radioprotecao e Dosimetria (IRD), Rio de Janeiro, RJ (Brazil); Ghilardi Netto, Thomaz [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Centro de Ciencias da Imagem e Fisica Medica

    1998-07-01

    For determining in vivo {sup 99m}Tc-MDP incorporated activity in bone tissue using a scintillation chamber as a image detection and acquisition system it is necessary the system calibration using an anthropomorphic physical simulator. The development of a tibia and fibula simulator in order to estimate bone tissue activity is presented. This procedure can be used either for workers monitoring or for the metabolic behavior of this radiopharmaceutical.

  2. Impregnation of 12-tungstophosphoric acid on silica - part I: determination of impregnation parameters, characterization and evaluation of catalytic activity; Impregnacao do acido 12-fosfotungstico em silica - parte I: determinacao de parametros de impregnacao, caracterizacao e avaliacao da atividade catalitica

    Scroccaro, Karine Isabel; Tanobe, Valcineide Oliveira de Andrade; Cocco, Lilian Cristina; Yamamoto, Carlos Itsuo, E-mail: karineisabel@yahoo.com.br [Universidade Federal do Parana, Curitiba, PR (Brazil). Centro Politecnico. Dept. de Engenharia Quimica; Wypych, Fernando [Universidade Federal do Parana, Curitiba, PR (Brazil). Centro Politecnico. Dept. de Quimica

    2012-07-01

    Catalyst based on Kegging-type heteropolyacids (H{sub 3}PW{sub 12}O{sub 40} - HPA), supported on SiO{sub 2} (H{sub 3}PW), were prepared by the impregnation method under different thermal treatment conditions. The materials were characterized by different instrumental techniques and used as catalysts in the methyl esterification reactions of stearic acid. Using the catalyst with 15% of HPA, conversions higher than 60% were obtained after 2 h of reaction at 65 deg C. Recovery studies using hot-filtration with ethanol at 75 deg C showed satisfactory activity for two additional reaction cycles. (author)

  3. Determining internal movement costs at a warehouse using activity-based costing: offshore petroleum production application; Determinacao dos custos de movimentacao interna de um deposito utilizando a metodologia de custeio baseado em atividades: aplicacao a producao de petroleo offshore

    Azevedo, Italo Ricardo Moreira de [Brasil Supply S.A., Vitoria, ES (Brazil); Leal, Jose Eugenio [Pontificia Univ. Catolica do Rio de Janeiro (PUC-Rio), RJ (Brazil)

    2004-07-01

    As from the flexibilization of the petroleum monopoly, which took place in the second half of the 1990's, the petroleum and gas sector in Brazil has undergone a series of changes that have directly impacted the commercial relations among the companies in the sector. The increases in operational efficiency and reduction of costs have become basic factors for the companies wishing to compete in this market. This paper presents a study whose objective is to map, model, and determine the costs involved in the process for internal movement in a warehouse used as logistics support to offshore petroleum production. Based on the description of the internal movement process for product storage, the main resources are identified. Then, a mathematical model based on Activity-Based Costing is draw up, in which the results generated comprise the values for internal movement costs for each type of product moved in the warehouse. (author)

  4. Absolute activity measurement and gamma-ray emission probability for decay of I-126; Medida absoluta da atividade e determinacao da taxa de emissao gama por decaimento do {sup 126} I

    Fonseca, Katia Aparecida

    1997-07-01

    The accurate knowledge of the gamma-ray emission probability per decay of radionuclides is important in several applications. In the case of {sup 126} I, its importance lies mainly in fast neutron dosimetry as well as in the production of {sup 125} I where {sup 126} I appears as an impurity. In the present work the gamma-ray emission probabilities per decay for the 388 and 666-KeV transitions of {sup 126} I have been measured. This radionuclide was obtained by means of the {sup 127} I(n, 2n){sup 126} I reaction in a fast neutron flux at the IPEN 2 MW research reactor. The methodology for the primary standardization of {sup 126} I is described. For this purpose, two different coincidence systems were used due to the complex decay scheme of this radionuclide. The {beta}branch measurement was carried out in a 4 {pi}(PC){beta}-{gamma} coincidence system consisting of a proportional counter, coupled to a pair of 3'x3' Na I (Tl) crystal. The electron capture branch was measured in a X-{gamma} coincidence system using two NaI(Tl) crystals. The gamma-ray measurements were performed in a HPGe system, previously calibrated by means of standard sources supplied by the International Atomic Energy Agency. All the uncertainties evolved were treated rigorously, by means of covariance analysis. (author)

  5. Determination of total alpha and beta activity in water for human consumption by LSC(Liquid Scintillation Counter); Determinacao de atividades alfa e beta total em agua para consumo humano por LSC (Contador de Cintilacao Liquida))

    NONE

    2013-07-01

    The Ordinance Brazilian of Ministry of Health (MS 2914/2011) establishes the standards for quality of water intended for human consumption, being limits values of 5.0 Bq/L for gross alpha, and 1.0 Bq/L for gross beta radioactivity. The liquid scintillation spectrometry (LSC) technique has been presented as an alternative to conventional procedure using gas flow proportional counter. The present work shows a review of the methods for determination of gross alpha and gross beta in water by using LSC. Between the factors that influence the accuracy and repeatability of the analytical results we can highlight: thermal preconcentration, type of the acid and calibration standard. A procedure was established and carried out to samples of the National Program of Intercomparison of Radionuclides in Environmental Samples for evaluation of its performance. The gross alpha and gross beta analysis in samples of the public water supplies in the Metropolitan Region of Goiania, state of Goias was carried out. The results are consistent with the guideline values form the Ministry of Health concerning radioactivity. (author)

  6. Forensic activation analysis

    Basic principles of neutron activation analysis are outlined. Examples of its use in police science include analysis for gunshot residues, toxic element determinations and multielement comparisons. Advantages of neutron activation analysis over other techniques are described. (R.L.)

  7. Neutron Activation Analysis

    Corliss, William R.

    1968-01-01

    In activation analysis, a sample of an unknown material is first irradiated (activated) with nuclear particles. In practice these nuclear particles are almost always neutrons. The success of activation analysis depends upon nuclear reactions which are completely independent of an atom's chemical associations. The value of activation analysis as a research tool was recognized almost immediately upon the discovery of artificial radioactivity. This book discusses activation analysis experiments, applications and technical considerations.

  8. 13. seminar 'Activation analysis'

    Collection of the abstracts of contributions to the seminar covering broad ranges of application of activation analysis and improvements of systems and process steps. Most of them have been prepared separately for the energy data bases. (RB)

  9. Activation analysis in Greece

    A review of research and development on NAA as well as examples of applications of this method are presented, taken from work carried out over the last 21 years at the Radioanalytical Laboratory of the Department of Chemistry in the Greek Nuclear Research Center ''Demokritos''. Improved and faster radiochemical NAA methods have been developed for the determination of Au, Ni, Cl, As, Cu, U, Cr, Eu, Hg and Mo in several materials, for the simultaneous determination of Br and I; Mg, Sr and Ni; As and Cu; As, Sb and Hg; Mn, Sr and Ba; Cd and Zn; Se and As; Mo and Cr in biological materials. Instrumental NAA methods have also been developed for the determination of Ag, Cl and Na in lake waters, Al, Ca, Mg and V in wines, 7 trace elements in biological materials, 17 trace elements in sediments and 20 minor and trace elements in ceramics. A comprehensive computer program for routine activation analysis using Ge(Li) detectors have been worked out. A rather extended charged-particle activation analysis program is carried out for the last 10 years, including particle induced X-ray emission (PIXE) analysis, particle induced prompt gamma-ray emission analysis (PIGE), other nuclear reactions and proton activation analysis. A special neutron activation method, the delayed fission neutron counting method is used for the analysis of fissionable elements, as U, Th, Pu, in samples of the whole nuclear fuel cycle including geological, enriched and nuclear safeguards samples

  10. SLOWPOKE: neutron activation analysis

    Neutron activation analysis permits the non-destructive determination of trace elements in crude oil and its derivatives at high sensitivity (up to 10-9 g/g) and good precision. This article consists of a quick survey of the method followed by an illustration based on the results of recent work at the SLOWPOKE reactor laboratory at the Ecole Polytechnique

  11. Forensic Activation Analysis

    The high sensitivity of high-flux (reactor) thermal-neutron activation analysis (NAA) for the detection and quantitative measurement of a large number of elements has led, in recent years, to a considerable degree of application of the method in the area of scientific crime investigation (criminalistics). Thus, in a Forensic Activation Analysis Bibliography recently compiled by the author, some 135 publications in this field are listed - and more are appearing quite rapidly. The nondestructive character of the purely-instrumental form of the method is an added advantage in forensic work, since evidence samples involved in actual criminal cases are not destroyed during analysis, but are preserved intact for possible presentation in court. Quite aside from, or in addition to, use in court, NAA results can be very helpful in the investigative stage of particular criminal cases. The ultra sensitivity of the method often enables one to analyze evidence specimens that are too tiny for meaningful analysis by more conventional elemental analysis methods. Also, this high sensitivity often enables one to characterize, or individualize, evidence specimens as to the possibility of common origin - via the principle of multi-element trace-constituent characterization

  12. Study on activation analysis

    High purity aluminum has been analyzed by neutron activation analysis. The determination of copper contents is aluminum has been used to evaluate its purity level. A new sensitive method has been developed by using graphite thermal column to reduce or eliminate the interference of 24Na which is generated from 27Al (n,α) 24Na reaction by fast neutron. Influence for activity of 24Na due to above reaction is found to be between 2.3 - 2.8 %. Copper contents in the high purity aluminum come out 0.542±0.084 ppm. In addition, contents of 23 other impurity elements (<0.1 - 0.01 ppm) are measured using general method after detection limit and optimum conditions are established. (author)

  13. Activation analysis in forensic studies

    Application of neutron activation analysis in forensics are grouped into 3 categories: firearms-discharge applications, elemental analysis of other nonbiological evidence materials (paint, other), and elemental analysis of biological evidence materials (multielemental analysis of hair, analysis of hair for As and Hg). 18 refs

  14. Determination of metals and rare earths in leach solution of phosphogypsum by instrumental neutron activation analysis (INAA); Determinacao de metais e terras raras em solucao lixiviada de fosfogesso por AANI

    Costa, Gabriela J.L., E-mail: glcosta@ipen.br [Universidade Nove de Julho, Sao Paulo, SP (Brazil); Saueia, Catia H.R.; Mazzilli, Barbara P., E-mail: chsaueia@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The phosphogypsum is a sub-product of the fertilizer industries and is composed of the gypsum matrix (CaSO{sub 4}.2H{sub 2}O) which naturally contains high tenors of impurities such as 2P{sub O}5 and metals coming from the original phosphat rock. The Brazilian phosphogypsum and the various uses has been researched through his elementary and radiochemistry characterization. This work determine the metals (As, Ba, Co and Se) and rare earths (La, Ce, Sm, Eu, Tb and Lu) presents in samples of phosphogypsum leach solutions

  15. Use of cyclic voltammetry and electrochemical impedance spectroscopy for determination of active surface area of modified carbon-based electrodes; Uso da voltametria ciclica e da espectroscopia de impedancia eletroquimica na determinacao da area superficial ativa de eletrodos modificados a base de carbono

    Souza, Leticia Lopes de

    2011-07-01

    Carbon-based electrodes as well the ion exchange electrodes among others have been applied mainly in the treatment of industrial effluents and radioactive wastes. Carbon is also used in fuel cells as substrate for the electrocatalysts, having high surface area which surpasses its geometric area. The knowledge of the total active area is important for the determination of operating conditions of an electrochemical cell with respect to the currents to be applied (current density). In this study it was used two techniques to determine the electrochemical active surface area of glassy carbon, electrodes and ion exchange electrodes: cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The experiments were carried out with KNO{sub 3} 0.1 mol.L{sup -1} solutions in a three-electrode electrochemical cell: carbon-based working electrode, platinum auxiliary electrode and Ag/AgCl reference electrode. The glassy carbon and porous carbon electrodes with geometric areas of 3.14 x 10{sup -2} and 2.83 X 10{sup -1} cm{sup 2}, respectively, were used. The ion exchange electrode was prepared by mixing graphite, carbon, ion exchange resin and a binder, and this mixture was applied in three layers on carbon felt, using a geometric area of 1.0 cm{sup 2} during the experiments. The capacitance (Cd) of the materials was determined by EIS using Bode diagrams. The value of 172 {mu}F.cm{sup -2} found for the glassy carbon is consistent with the literature data ({approx} 200 {mu}F.cm'-{sup 2}). By VC, varying the scan rate from 0.2 to 2.0 mV.s-1, the capacitance CdS (S = active surface area) in the region of the electric double layer (EDL) of each material was determined. By EIS, the values of C{sub d}, 3.0 x 10{sup -5} {mu}F.cm'-{sup 2} and 11 x 10{sup 3} {mu}F.cm-2, were found for the porous carbon and ion exchange electrodes, respectively, which allowed the determination of active surface areas as 3.73 x 106 cm{sup 2} and 4.72 cm{sup 2}. To sum up, the

  16. Application of neutron activation analysis

    The physical basis and analytical possibilities of neutron activation analysis have been performed. The number of applications in material engineering, geology, cosmology, oncology, criminology, biology, agriculture, environment protection, archaeology, history of art and especially in chemical analysis have been presented. The place of the method among other methods of inorganic quantitative chemical analysis for trace elements determination has been discussed

  17. Analysis of Precision of Activation Analysis Method

    Heydorn, Kaj; Nørgaard, K.

    1973-01-01

    The precision of an activation-analysis method prescribes the estimation of the precision of a single analytical result. The adequacy of these estimates to account for the observed variation between duplicate results from the analysis of different samples and materials, is tested by the statistic T...

  18. TIBER activation analysis

    TIBER-II is an engineering test reactor designed to establish the technical feasibility for fusion, and is a U.S. option for the prospective International Thermonuclear Test Reactor (ITER). The TIBER-II baseline design has a 3 m major radius, 3.6 aspect ratio, and 1.1 MW/m2 average neutron wall loading. The inboard shield is about .5 m thick and structurally consists of tungsten alloy and PCA alloy. The outboard is 1.52 m thick and utilizes PCA as structure and beryllium as a neutron multiplier. An aqueous solution of 160 g LiNO3/liter is used throughout as a coolant and breeder. A one-dimensional cylindrical model for TIBER is used to calculate the neutron flux and the radioactivities. Activities are calculated during and after 2.5 full power years (FPY) of operation

  19. Activation analysis using Cornell TRIGA

    A major use of the Cornell TRIGA is for activation analysis. Over the years many varieties of samples have been analyzed from a number of fields of interest ranging from geology, archaeology and textiles. More recently the analysis has been extended to high technology materials for applications in optical and semiconductor devices. Trace analysis in high purity materials like Si wafers has been the focus in many instances, while in others analysis of major/minor components were the goals. These analysis has been done using the delayed mode. Results from recent measurements in semiconductors and other materials will be presented. In addition the near future capability of using prompt gamma activation analysis using the Cornell cold neutron beam will be discussed. (author)

  20. Standardizing Activation Analysis: New Software for Photon Activation Analysis

    Photon Activation Analysis (PAA) of environmental, archaeological and industrial samples requires extensive data analysis that is susceptible to error. For the purpose of saving time, manpower and minimizing error, a computer program was designed, built and implemented using SQL, Access 2007 and asp.net technology to automate this process. Based on the peak information of the spectrum and assisted by its PAA library, the program automatically identifies elements in the samples and calculates their concentrations and respective uncertainties. The software also could be operated in browser/server mode, which gives the possibility to use it anywhere the internet is accessible. By switching the nuclide library and the related formula behind, the new software can be easily expanded to neutron activation analysis (NAA), charged particle activation analysis (CPAA) or proton-induced X-ray emission (PIXE). Implementation of this would standardize the analysis of nuclear activation data. Results from this software were compared to standard PAA analysis with excellent agreement. With minimum input from the user, the software has proven to be fast, user-friendly and reliable.

  1. Economical aspects and analysis for the determination of the economic viability of a gas microturbine operating as a electric power generation system; Analise e aspectos economicos para determinacao da viabilidade economica de uma microturbina a gas operando como sistema de geracao de energia eletrica

    Venson, Giuliano Gardolinski [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)]. E-mails: venson@ufmg.br; Barros, Jose Eduardo Mautone [Centro Federal de Educacao Tecnologica de Minas Gerais, Belo Horizonte, MG (Brazil)]. E-mail: mautone@des.cefetmg.br; Ayres, Naiara Pacheco [Grupo Irmaos Ayres S.A., Contagem, MG (Brazil)]. E-mail: pacheco@iasa.ind.br

    2006-07-01

    This paper presents the methodology used for the criteria determination of the economic viability of a gas microturbine in development the operating parallel to the central distribution network. The study intends to verify the influence of the acquisition cost, the specific cost of the operation and the financing rate applied to the microturbine related to the economic viability criteria. The criteria used are based on investment analysis analytical methods such as the return internal rate. For the development of the methodology the energy demand and consumption data of a medium size have been used.

  2. Using of the serial graph connection for the determination of the relative permeability of reservoir rocks; Utilizacao do grafo de conexao serial para a determinacao da permeabilidade relativa de rochas reservatorio

    Bueno, A.D. [Universidade Estadual do Norte Fluminense, Macae, RJ (Brazil). Lab. de Engenharia e Exploracao e Producao de Petroleo (LENEP); Philippi, P.C. [Santa Catarina Univ., Florianopolis, SC (Brazil). Lab. de Meios Porosos e Propriedades Termofisicas dos Materiais (LMPT)]. E-mail: philippi@lmpt.ufsc.br

    2003-07-01

    In recent work Bueno and others (Bueno A.D., Magnani F. S., Philippi P.C, 'Metodo para Determinacao da Permeabilidade Relativa de Rochas Reservatorio de Petroleo Atraves da Analise de Imagens Reconstruidas, 'IX Congresso Brasileiro de Engenharia e Ciencias Termicas - ENCIT, Caxambu - MG - Brasil, 2002), presented a methodology for the determination of relative permeability of reservoir rocks, using an opening algorithm to determine the equilibrium configuration of fluid phases, water and oil in reconstructed 3D media and the serial graph connection method to determine the permeabilities of the phase, at each pressure step. In this paper, the first results of application of this methodology, and comparison with experimental results are presented. (author)

  3. Charged-particle activation analysis

    The paper discusses the methodology and application of nuclear activation with ion beams (19 via 16O(3He,p)18F, 12C(3He,α)11C and 14N(p,α)11C respectively. Recently, triton activation has been shown to be inherently still superior to 3He activation for the determination of oxygen [16O(3H,n)18F]. Lithium, boron, carbon and sulphur can be detected rapidly, nondestructively and with high sensitivity (approximately 0.25ppm for Li and B) via ''quasi-prompt'' activation based on the detection of short-lived, high-energy beta emitters (10ms1H(7Li,n)7Be for example. Nondestructive multielement analysis: Proton activation has the inherent potential for meeting requirements of broad elemental coverage, sensitivity (ppm and sub-ppm range) and selectivity. Up to 30 elements have been determined in Al, Co, Ag, Nb, Rh, Ta and biological samples, using 12-MeV proton activation followed by gamma-ray spectrometry. These capabilities are further enhanced with the counting of X-ray emitters, 28 elements (269) and accuracy using proton activation. 204Pb/206Pb ratios can also be determined with a relative precision of a few per cent. Although charged-particle activation analysis is a well-established trace analysis technique, broad potential capabilities remain to be explored, e.g. those arising from ultrashort-lived nuclides, heavy ion interactions and the combination of delayed and prompt methods. (author)

  4. Neutron activation analysis of coins

    Activation analysis was applied to the study of coins using 14MeV neutrons produced by an accelerator for the determination of oxygen and neutrons emitted from a 252Cf source for the determination of the other elements (Au, Ag, Cu, As etc...). The advantages of this technique are presented

  5. Automated activation-analysis system

    An automated delayed neutron counting and instrumental neutron activation analysis system has been developed at Los Alamos National Laboratory's Omega West Reactor (OWR) to analyze samples for uranium and 31 additional elements with a maximum throughput of 400 samples per day. The system and its mode of operation for a large reconnaissance survey are described

  6. Sensitivity analysis for activation problems

    A study has been made about how to develop further the techniques for sensitivity analysis used by FISPACT-II. FISPACT-II is a software suite for the analysis of nuclear activation and transmutation problems, developed for all nuclear applications. The software already permits sensitivity analysis to be performed by Monte Carlo sampling, and a faster uncertainty analysis is made possible by a powerful graph-based approach which generates a reduced set of nuclides on pathways leading to significant contributions to radiological quantities. The peculiar aspects of the sensitivity analysis problem for activation are the large number, typically thousands, of rate equation parameters (decay rates and reaction cross-sections) which all have some degree of associated error, and the fact that activity as a function of time varies as a sum of exponentials, so appears discontinuous as rate parameters are varied unless the sampling frequency is impracticably fast. Nevertheless, Monte Carlo sampling is a generic approach and it is therefore conceivable that techniques more targeted to the activation problem might be beneficial. Moreover, recent theoretical developments have highlighted the importance of a two-stage approach to mathematically similar problems, where in the first stage, information is collected about the global behaviour of the problem, such as the identification of the rate parameters which cause the greatest variation in dose or nuclear activity, before a second stage examines a problem with its scope restricted by the information from the first. In the second stage, for example, Quasi-Monte Carlo sampling may be used in a restricted parameter space. The current work concentrates on the first stage and consists of a review of possible techniques with a detailed examination of the most promising pathways reduction approach, examined directly using FISPACT-II. All the evidence obtained demonstrates the strong potential of this approach. (authors)

  7. Activation analysis using γ photons

    This report summarizes all the data required for using photonuclear reactions in the field of analysis. After a brief review of the elementary properties of nuclear reactions induced by photon irradiation, the main characteristics are given of high energy (E > 20 MeV) Bremsstrahlung sources. The principle of activation analysis based on the use of photons is given. Actual examples of the analytic possibilities are described in detail, in particular in the case of the determination of very small quantities (-6) of C, N, O and F. The influence of interfering nuclear reactions is discussed. (author)

  8. Optimization of instrumental activation analysis

    Activation analysis is one of the most well-understood methods available to the analyst. It should, therefore, be possible to infer, from prior information about the sample, what procedure should be followed in its analysis. The accuracy of this process is naturally limited by the extent and accuracy of the prior information available. Better results should be obtained in this way, however, than by ignoring prior information. It is the task of optimization to discover the analytical procedure that best suits the sample being analyzed. Optimization can be conveniently conceptualized if each experimental parameter is considered as a dimension of a geometric space. In activation analysis, if only irradiation and decay times are to be adjusted, the parameter space will be two dimensional. Each point in the parameter space corresponds to a possible procedure for carrying out a determination and each such procedure will perform more or less satisfactorily than others. Optimization, then, consists of a search for a point or a region in parameter space where performance meets the analyst's requirements. Practicality is an important consideration in designing a procedure for activation analysis. There are limits to the amount of radioactive material that can be handled safely and to the count rate that be accurately measured. Circumstances often impose further limits. It is, therefore, necessary to constrain the search of parameter space to those regions that correspond to practical procedures. In attempting an optimization, one must consider a number of aspects. A set of experimental parameters must be chosen for adjustment and others set at fixed values, often due to practical constraints. The way in which quality of analytical performance (the response function) is to be evaluated must be decided. A means of locating the optimum must be chosen and, finally, this optimization scheme must be implemented in a practical, convenient manner. These aspects are discussed

  9. Instrumentation in neutron activation analysis

    The rise of neutron activation analysis (NAA) as a tool in geochemical research has parallelled advances in detector, multi-channel analyzer, and computer technology. Micro-computers are now being integrated into NAA systems, and gamma-ray spectrometer instrumentation is evolving towards direct-reading systems. The investigator is faced with a wide range of possibilities and choices when equipping or re-equipping a laboratory. The geoscientist is provided with an overview of the available instrumentation and what soon may be feasible. (L.L.)

  10. Analysis of Sunspot Activity Cycles

    Greenkorn, Robert A.

    2009-04-01

    A nonlinear analysis of the daily sunspot number for each of cycles 10 to 23 is used to indicate whether the convective turbulence is stochastic or chaotic. There is a short review of recent papers considering sunspot statistics and solar activity cycles. The differences in the three possible regimes - deterministic laminar flow, chaotic flow, and stochastic flow - are discussed. The length of data sets necessary to analyze the regimes is investigated. Chaos is described and a chronology of recent results that utilize chaos and fractals to analyze sunspot numbers follows. The parameters necessary to describe chaos - time lag, phase space, embedding dimension, local dimension, correlation dimension, and the Lyapunov exponents - are determined for the attractor for each cycle. Assuming the laminar regime is unlikely if chaos is not indicated in a cycle by the calculations, the regime must be stochastic. The sunspot numbers in each of cycles 10 to 19 indicate stochastic behavior. There is a transition from stochastic to chaotic behavior of the sunspot numbers in cycles 20, 21, 22, and 23. These changes in cycles 20 - 23 may indicate a change in the scale of turbulence in the convection zone that could result in a change in the convective heat transfer and a change in the size of the convection region for these four cycles.

  11. Neutron activation analysis in Bulgaria

    The development of instrumental neutron activation analysis (INAA) as a routine method started in 1960 with bringing into use of the experimental nuclear reactor 2 MW -IRT-2000. For the purposes of INAA the vertical channels were used. The neutron flux vary from 1 to 6x1012n/cm2s, with Cd ratio for gold of about 4,4. In one of the channels the neutron flux is additionally thermalised with grafite, in others - a pneumatic double-tube rabbit system is installed. One of the irradiation positions is equiped with 1 mm Cd shield constantly. With the pressure of the working gas (air) of 2 bar the transport time in one direction is 2,5 sec. Because of lack of special system for uniform irradiation an accuracy of 3% can be reached by use of iron monitors for long irradiations and copper monitors for use in the rabbit system. Two neutron generators are also working but the application of 14 MeV neutrons for INAA is still quite limited. The most developed are the applications of INAA in the fields of geology and paedology, medicine and biology, environment and pollution, archaeology, metallurgy, metrology and hydrology, criminology

  12. Conference on instrumental activation analysis IAA 92

    The publication contains 26 abstracts primarily concerned with neutron activation analysis, although other analytical techniques based on X-ray fluorescence analysis, PIXE, PIGE, RBS are also included. Some contributions deal with aspects of quality practice and assurance in radioanalytical laboratories, with marketing of instrumental neutron activation analysis services, with hard- and software aspects of radiation detection, etc. (Z.S.)

  13. Instrumental neutron activation analysis - a routine method

    This thesis describes the way in which at IRI instrumental neutron activation analysis (INAA) has been developed into an automated system for routine analysis. The basis of this work are 20 publications describing the development of INAA since 1968. (Auth.)

  14. Activation analysis with reactor neutrons

    The potentialities of neutron as an analytical probe are indicated, pointing out the need for development of other approaches, besides the conventional activation method. Development of instrumental approach to activation and applications, carried out at Analytical Chemistry Division are outlined. The role of, and the need for, the development and application of mathematical methods in enhancing the information content, and in turn the interpretation of the analytical results, is demonstrated. (author)

  15. Transportation activity analysis using smartphones

    Xiao, Yu; Low, David; Bandara, Thusitha; Pathak, Parth; Lim, Hock Beng; Goyal, Devendra; Santos, Jorge Oliveira; Cottrill, Caitlin; Pereira, Francisco C.; Zegras, P. Christopher; Ben-Akiva, Moshe E.

    2012-01-01

    Transportation activity surveys investigate when, where and how people travel in urban areas to provide information necessary for urban transportation planning. In Singapore, the Land Transport Authority (LTA) carries out such a survey amongst households every four years. The survey is conducted through conventional questionnaires and travel diaries. However, the conventional surveys are problematic and error-prone. We are developing a smartphone-based transportation activity survey system to...

  16. Neutron activation analysis of biological substances

    A Bowen cabbage sample was used as a reference material for the neutron activation studies, and the method was checked by the analysis of other biological substances (blood or serum etc.). For nondestructive measurements also some non-trace elements were determined in order to decide whether the activation analysis is a useful means for such measurements. The new activation analysis procedure was used for biomedical studies as, e.g., for trace element determination in body fluids, and for the analysis of inorganic components in air samples. (R.P.)

  17. Analysis of HR activities in selected company

    Jandová, Šárka

    2012-01-01

    The aim of this thesis is based on theoretical knowledge and analysis of the basic HR activities in the selected company to identify the strengths and weaknesses of the policies implemented personnel work. Then propose an effective ways of improving HR activities and employee satisfaction. Basic personal activities analyzed in this thesis are the adaptation, acquisition and selection of employees, performance management and staff appraisal, remuneration and training of staff. Analysis of pers...

  18. Conference on instrumental activation analysis - IAA 89

    The proceedings contain 40 abstracts of papers all of which have been incorporated in INIS. The papers were centred on the applications of radioanalytical methods, especialy on neutron activation analysis, X-ray fluorescence analysis, PIXE analysis and tracer techniques in biology, medicine and metallurgy, measuring instruments including microcomputers, and data processing methods. (J.P.)

  19. Conference on Instrumental Activation Analysis: IAA 89

    Vobecky, M.; Obrusnik, I.

    1989-05-01

    The proceedings contain 40 abstracts of papers all of which have been incorporated in INIS. The papers were centred on the applications of radioanalytical methods, especially on neutron activation analysis, x ray fluorescence analysis, PIXE analysis and tracer techniques in biology, medicine and metallurgy, measuring instruments including microcomputers, and data processing methods.

  20. Neutron activation analysis of reference materials

    The importance is pointed out of neutron activation analysis in the preparation of reference materials, and studies are reported conducted recently by UJV. Instrumental neutron activation analysis has been used in testing homogeneity and in determining 28 elements in newly prepared reference standards of coal fly ash designated ENO, EOP and ECH. For accuracy testing, the same method was used in the analysis of NBS SRM-1633a Trace Elements in Coal Fly Ash and IAEA CRM Soil-5 and RM Soil-7. Radiochemical neutron activation analysis was used in determining Cd, Cu, Mn, Mo, and Zn in biological materials NBS SRM-1577 Bovine Liver, Bowen's Kale and in IAEA RM Milk Powder A-11 and Animal Muscle H-4. In all instances very good precision and accuracy of neutron activation analysis results were shown. (author)

  1. Activation analysis in virus research

    Nucleic acids contain various amounts of trace elements. With divalent cations tobacco mosaic virus ribonucleic acid (TMV-RNA) undergoes changes in optical density at 258 mμ in both optical rotation and in sedimentation behaviour. These changes suggested the transformation from a random coil to a more orderly configuration. The connection between trace elements and the biological activity of TMV-RNA has been investigated. However, the relationship between metal ions and the virus infection process has not received much attention. This subject is discussed briefly in this paper. 8 refs

  2. Neutron activation analysis of geochemical samples

    The present paper will describe the work done at the Technical Research Centre of Finland in developing methods for the large-scale activation analysis of samples for the geochemical prospecting of metals. The geochemical prospecting for uranium started in Finland in 1974 and consequently a manually operated device for the delayed neutron activation analysis of uranium was taken into use. During 1974 9000 samples were analyzed. The small capacity of the analyzer made it necessary to develop a completely automated analyzer which was taken into use in August 1975. Since then 20000-30000 samples have been analyzed annually the annual capacity being about 60000 samples when running seven hours per day. Multielemental instrumental neutron activation analysis is used for the analysis of more than 40 elements. Using instrumental epithermal neutron activation analysis 25-27 elements can be analyzed using one irradiation and 20 min measurement. During 1982 12000 samples were analyzed for mining companies and Geological Survey of Finland. The capacity is 600 samples per week. Besides these two analytical methods the analysis of lanthanoids is an important part of the work. 11 lanthanoids have been analyzed using instrumental neutron activation analysis. Radiochemical separation methods have been developed for several elements to improve the sensitivity of the analysis

  3. Determination of methodology of automatic history matching; Determinacao de metodologia de ajuste automatizado de historico

    Santos, Jose Pedro Moura dos

    2000-01-01

    In management of hydrocarbon reservoirs the numeric simulation is a fundamental tool. The validation of a field model with production report is made through history matching which, many times, is done by trial and errors procedures consuming excessive computational time and human efforts. The objective of this work is to present a methodology for automation of the history matching using the program UNIPAR with the modules of parallel computing, sensibility analysis and optimization. Based on an example of an offshore field, analyses of the objective function (water production, oil production and average pressure of the reservoir) behavior were accomplished as function of the variations of reservoir parameters. It was verified that this behavior is very regular. After that, several adjustment situations were tested to define a procedure to be used for a history matching. (author) Ate aqui estao scanned.

  4. Applications of neutron activation analysis in industry

    Neutron activation analysis technique is discussed in brief. This technique is used for quality control of raw materials, process materials and finished products, as well as activities in research and development for the improvement of the products and new products. The uses of this technique in several experienced industries are mentioned (author)

  5. Algorithm for numerical determination of form factor; Algoritmo para determinacao numerica de fator de forma

    Augusto, Lilian Dobrowolski de Carvalho; Giacomet, Bruno; Jonsson, Marluz; Mendes, Nathan [Pontificia Universidade Catolica do Parana (PUC-PR), Curitiba, PR (Brazil). Lab. de Sistemas Termicos], e-mail: liliandoca@gmail.com, e-mail: handriel@gmail.com, e-mail: nathan.mendes@pucpr.br, e-mail: marluzjonsson@bol.com.br; Cumin, Liliana Madalena Gramani [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Matematica], e-mail: gramani@mat.ufpr.br

    2006-07-01

    The view factor is determined via the resolution of a double integral. These solutions, for some surfaces, are presented for many different configurations, in form of equations, graphs and tables in the literature. The idea of creating a numerical method to calculate the view factor appears when it is needed to calculate it for surfaces with complex geometries. For instance, in building simulation programs, the view factor is normally calculated in a simplified way for these geometries, disregarding openings and obstructions. This implicates errors in the accuracy of thermal comfort calculation and energy consumption. The objective of this work is to present a computational structure to determine view factors between two surfaces, with simple or complex geometries, using resources of graphical computation to 2D meshes with triangular elements of Delaunay. The results gotten for simple geometries are compared with available data in the literature and an excellent agreement is observed. The sensitivity analysis to the mesh refinement and the distance between the surfaces is also presented. (author)

  6. New studies in forensic neutron activation analysis

    Three recently completed studies in forensic neutron activation analysis are reported: a study of 0.22-caliber rimfire cartridge primers, a large-scale study of shotgun pellets, and a new 5-element procedure for the analysis of bullet-lead and shotgun-pellet samples. (author) 12 refs

  7. New studies in forensic neutron activation analysis

    Earlier studies in forensic neutron activation analysis are being extended in This Laboratory. Three of these new studies are reported here: 1) a study of 0.22-caliber rimfire cartridge primers, 2) a large-scale study of shotgun pellets, and 3) a new 5-element procedure for the analysis of bullet-lead and shotgun-pellet samples. (author)

  8. A program for activation analysis data processing

    An ALGOL program for activation analysis data handling is presented. The program may be used either for single channel spectrometry data or for multichannel spectrometry. The calculation of instrumental error and of analysis standard deviation is carried out. The outliers are tested, and the regression line diagram with the related observations are plotted by the program. (author)

  9. Evaluation of business activity using financial analysis

    Kučerová, Martina

    2012-01-01

    Czech University of Life Sciences Prague Faculty of Economics and Management Department of Trade and Accounting Abstract of Diploma Thesis Evaluation of business activity using financial analysis Martina Kučerová © 2012 CULS in Prague Summary: The aim of this thesis is to apply methods of financial analysis on chosen business for its first three accounting periods 2009, 2010 and 2011. The thesis is further analysis of my bachelor thesis on to...

  10. Activation analysis in science and technics

    Physical bases of the method of neutron activation analysis are described. Reactions of element nuclei with neutrons, gamma quanta and charged particles, ways of radioactivity measurement, gamma spectrometry in particular, have been described. The method errors, as well as element determination sensitivity in samples of different composition are considered, perspectives of activation analysis development being reflected. The practical use of the method in the studies on solid-state physics, during the analysis of semiconductors and pure materials, in criminalistics, agriculture, the environmnental control in geology and biology, is shown

  11. Human hair neutron activation analysis: analysis on population level, mapping

    Neutron activation analysis is an outstanding analytical method having very wide applications in various fields. Analysis of human hair within last decades mostly based on neutron activation analysis is a very attractive illustration of the application of nuclear analytical techniques. Very interesting question is how the elemental composition differs in different areas or cities. In this connection the present paper gives average data and maps of various localities in the vicinity of drying-out Aral Sea and of various industrial cities in Central Asia. (author)

  12. Activation analysis as applied to environmental substances

    The historical background of activation analysis as applied to environmental problems is first briefly described. Then, the present state of its utilization for environmental samples, mainly atmospheric floating particles and human hairs, is reviewed. The problem with irradiation reactors is also mentioned. In the activation analysis of environmental substances, the instrumental neutron activation analysis (INAA) with the thermal neutrons in reactors is the main; besides, there are the methods with bremsstrahlung, etc. The INAA is most effectively used for atmospheric airborne particles and the micro-elements in human hairs. In Japan, the INAA is currently employed by the Environmental Agency in its national air pollution surveillance network for metallic pollutants. The problem with reactors is the limited capacity for thermal neutron irradiation. (Mori, K.)

  13. Neutron activation spectrometry and neutron activation analysis in analytical geochemistry

    The present report is to show the geochemists who are interested in neutron activation spectrometry (NAS) and neutron activation analysis (NAA) which analytical possibilities these methods offer him. As a review of these analytical possibilities, a lieterature compolation is given which is subdivided into two groups: 1) rock (basic, intermediary, acid, sediments, soils and nuds, diverse minerals, tectites, meteorites and lunar material). 2) ore (Al, Au, Be, Cr, Cu, Mn, Mo, Fe, Pb, Pt, Sn, Ti, W, Zn, Zr, U and phosphate ore, polymetallic ores, fluorite, monazite and diverse ores). The applied methods as well as the determinable elements in the given materials can be got from the tables. On the whole, the literature evaluation carried out makes it clear that neutron activation spectrometry is a very useful multi-element method for the analysis of rocks. The analysis of ores, however, is subjected to great limitations. As rock analysis is very frequently of importance in prospecting for ore deposits, the NAS proves to be extremely useful for this very field of application. (orig./LH)

  14. High-capacity neutron activation analysis facility

    A high-capacity neutron activation analysis facility, the Reactor Activation Facility, was designed and built and has been in operation for about a year at one of the Savannah River Plant's production reactors. The facility determines uranium and about 19 other elements in hydrogeochemical samples collected in the National Uranium Resource Evaluation program, which is sponsored and funded by the United States Department of Energy, Grand Junction Office. The facility has a demonstrated average analysis rate of over 10,000 samples per month, and a peak rate of over 16,000 samples per month. Uranium is determined by cyclic activation and delayed neutron counting of the U-235 fission products; other elements are determined from gamma-ray spectra recorded in subsequent irradiation, decay, and counting steps. The method relies on the absolute activation technique and is highly automated for round-the-clock unattended operation

  15. Design of Neutron Activation Analysis Laboratorium Room

    Base on the planning to increase of the research and service quality in the ''Neutron activation analysis'' (APN),the design of mentioned ''Neutron activation analysis laboratories room'' has been done in the multi purpose reactor G.A. Siwabessy. By the using the designed installation, the irradiation preparation and counting sample can be done. The design doing by determination of installation lay out and maximum particle contain in the air. The design installation required a unit of 1 HP blower, a unit of 1 HP split air condition and 2 units 1200 x 800 mm HEPA filter. This paper concluded that this design is feasible to fabricated

  16. Activation analysis of air particulate matter

    This review on activation analysis of air particulate matter is an extended and updated version of a review given by the same authors in 1985. The main part is aimed at the analytical scheme and refers to rules and techniques for sampling, sample and standard preparation, irradiation and counting procedures, as well as data processing, - evaluation, and - presentation. Additional chapters deal with relative and monostandard methods, the use of activation analysis for atmosphere samples in various localities, and level of toxic and other elements in the atmosphere. The review contains 190 references. (RB)

  17. Prospects for absolute neutron activation analysis

    The desirability for absolute neutron activation analysis(ANAA) is two-fold. Results by the comparitor method are only as good as the standards used, and also the method offers a chance of having the final results available within minutes of completing the analysis. In the past ANAA was not seriously considered because of the scarcity and poor qaulity of the nuclear data that were available. This situation is however steadily improving and the possible applications are being investigated. This report reviews the present status by considering the basic activation equation, calculation of parameters, the factors of importance and the size error one might expect

  18. Sensitivity enhancement of short time activation analysis by pulse activation

    TRIGA-reactors have the unique possibility of increasing the power by a factor of up to 1200, to produce a corresponding up to 1200 fold increase in flux by pulsing the reactor. This feature is, however, seldom applied for activation analysis owing to the fact that the sensitivity enhancement is optimal only for short lived nuclides or isometric states in the sub-second range of half lives. As the maximal information density is confined to a short time interval, a fast transfer system and a measuring system allowing to handle the extremely high countrates are imperative. Both systems now being commercially available, it is possible to overcome the major draw back of conventional activation analysis, namely the long time delay between arrival of the sample and obtaining the results, for those elements having short lived nuclides or isomeric states

  19. Quality assurance in biomedical neutron activation analysis

    The summary report represents an attempt to identify some of the possible sources of error in in vitro neutron activation analysis of trace elements applied to specimens of biomedical origin and to advise on practical means to avoid them. The report is intended as guidance for all involved in analysis, including sample collection and preparation for analysis. All these recommendations constitute part of quality assurance which is here taken to encompass the two concepts - quality control and quality assessment. Quality control is the mechanism established to control errors, while quality assessment is the mechanism used to verify that the analytical procedure is operating within acceptable limits

  20. Prompt gamma-ray activation analysis (PGAA)

    Kern, J. [Fribourg Univ. (Switzerland). Inst. de Physique

    1996-11-01

    The paper deals with a brief description of the principles of prompt gamma-ray activation analysis (PGAA), with the detection of gamma-rays, the PGAA project at SINQ and with the expected performances. 8 figs., 3 tabs., 10 refs.

  1. Transforming Teacher Education, An Activity Theory Analysis

    McNicholl, Jane; Blake, Allan

    2013-01-01

    This paper explores the work of teacher education in England and Scotland. It seeks to locate this work within conflicting sociocultural views of professional practice and academic work. Drawing on an activity theory framework that integrates the analysis of these seemingly contradictory discourses with a study of teacher educators' practical…

  2. The Atomic Fingerprint: Neutron Activation Analysis

    Keisch, Bernard [Carnegie-Mellon University

    1972-01-01

    The nuclei of atoms are stable only when they contain certain numbers of neutrons and protons. Since nuclei can absorb additional neutrons, which in many cases results in the conversion of a stable nucleus to a radioactive one, neutron activation analysis is possible.

  3. Isotopic neutron sources for neutron activation analysis

    This User's Manual is an attempt to provide for teaching and training purposes, a series of well thought out demonstrative experiments in neutron activation analysis based on the utilization of an isotopic neutron source. In some cases, these ideas can be applied to solve practical analytical problems. 19 refs, figs and tabs

  4. Neutron activation analysis helps in picture attribution

    The neutron activation analysis application for obtaining the data useful for proper attribution of paintings has been presented on the base of several examples. The identification on this way of dye elements, pigments and other painting materials is an important element among the physico-chemical methods helping the attribution procedure of old painting objects

  5. Neutron Activation Analysis with k0 Standardization

    SCK-CEN's programme on Neutron Activation Analysis with k0-standardisation aims to: (1) develop and implement k0-standardisation method for NAA; (2) to exploit the inherent qualities of NAA such as accuracy, traceability, and multi-element capability; (3) to acquire technical spin-off for nuclear measurements services. Main achievements in 1997 are reported

  6. Analysis of an iodide radioimmunoassay for 11-deoxicortisol measurement; Analise de um radioimunoensaio iodado para determinacao de 11-deoxicortisol

    Madeira, Joao Luiz de Oliveira; Bussmann, Luciane Zgoda; Lima-Valassi, Helena Panteliou; Mendonca, Berenice Bilharinho de, E-mail: joao.madeira@usp.br [Universidade de Sao Paulo (HCFM/USP), SP (Brazil). Hospital das Clinicas. Departamento de Clinica Medica

    2014-04-15

    Objective: our aim was to correlate 11-deoxycortisol levels obtained by two currently available techniques for 11-deoxycortisol measurement: radioimmunoassay, and high performance liquid chromatography followed by tandem mass spectrometry (MS/MS). The latter is the gold standard method for steroid hormone measurement. Materials and methods: we selected 88 samples and the results of these two methods were compared by Deming regression. Results: the analytical sensitivity of the RIA was 0.30 ng/mL, with inadequate linearity and inadequate precision profile (34% of the samples had a CV ≥ 20%). From the selected samples, 54 had measurable levels of 11-deoxycortisol in both methods and were used in the comparison. The comparison of RIA with LC-MS/MS showed an overestimation of the results by RIA. The correlation coefficient was 0.610; linear regression slope was 3.751; and the intercept was 0.145, indicating a poor correlation between the two methods. Conclusion: we concluded that 11-deoxycortisol measured by radioimmunoassay, despite a good analytical sensitivity, showed very low specificity, precluding its use as a reliable method for 11-deoxycortisol measurement. (author)

  7. Trace elements determination in ginseng and ginkgo biloba medicinal plants; Determinacao de elementos traco nos fitofarmacos ginseng e ginkgo biloba

    Avino, Simone; Saiki, Mitiko; Fulfaro, Roberto [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Lab. de Analise por Ativacao Neutronica

    2002-07-01

    Determinations of trace elements in medicinal plants or in their extracts are of great interest since some elements are components of active constituents or they can affect the plant metabolism and consequently the formation of active constituents. In this work, inorganic components in medicinal drugs, Ginseng e Ginkgo Biloba provided from different laboratories, were analyzed by neutron activation analysis. Elements As, Br, Ca, Cl, Co Cr, Cs, Fe, K, La, Mg, Mn, Na, Rb, Sb, Sc, and Zn, were determined in these samples. Comparisons carried out between the results obtained for samples from different laboratories indicated distinct concentrations for several elements. These results may be attributed to the effect of soil composition and environmental conditions where these plants were cultivated. The precision and accuracy of the results were evaluated by analyzing reference materials Bowen's Kale from IUAPC and Cabbage from IAEA. (author)

  8. Computational Models for Analysis of Illicit Activities

    Nizamani, Sarwat

    devise policies to minimize them. These activities include cybercrimes, terrorist attacks or violent actions in response to certain world issues. Beside such activities, there are several other related activities worth analyzing, for which computational models have been presented in this thesis....... These models include a model for analyzing evolution of terrorist networks; a text classification model for detecting suspicious text and identification of suspected authors of anonymous emails; and a semantic analysis model for news reports, which may help analyze the illicit activities in certain area...... with location and temporal information. For the network evolution, the hierarchical agglomerative clustering approach has been applied to terrorist networks as case studies. The networks' evolutions show that how individual actors who are initially isolated from each other are converted in small groups, which...

  9. Analysis by neutron activation analysis a some ancient Dacian ceramics

    Olariu, A

    1999-01-01

    Ancient Dacian ceramics, from three different establishments from Romanian territory have been analyzed by neutron activation analysis. A series of elements has been determined: Ba, Eu, K, La, Mn, Na, Sc, Sm. Ba is the element that could be considered to differentiate relatively the three groups of ceramics.

  10. Neutron activation analysis of Etruscan pottery

    Neutron activation analysis (NAA) has been widely used in archaeology for compositional analysis of pottery samples taken from sites of archaeological importance. Elemental profiles can determine the place of manufacture. At Cornell, samples from an Etruscan site near Siena, Italy, are being studied. The goal of this study is to compile a trace element concentration profile for a large number of samples. These profiles will be matched with an existing data bank in an attempt to understand the place of origin for these samples. The 500 kW TRIGA reactor at the Ward Laboratory is used to collect NAA data for these samples. Experiments were done to set a procedure for the neutron activation analysis with respect to sample preparation, selection of irradiation container, definition of activation and counting parameters and data reduction. Currently, we are able to analyze some 27 elements in samples of mass 500 mg with a single irradiation of 4 hours and two sequences of counting. Our sensitivity for many of the trace elements is better than 1 ppm by weight under the conditions chosen. In this talk, details of our procedure, including quality assurance as measured by NIST standard reference materials, will be discussed. In addition, preliminary results from data treatment using cluster analysis will be presented. (author)

  11. Computer modeling for neutron activation analysis methods

    Full text: The INP AS RU develops databases for the neutron-activation analysis - ND INAA [1] and ELEMENT [2]. Based on these databases, the automated complex is under construction aimed at modeling of methods for natural and technogenic materials analysis. It is well known, that there is a variety of analysis objects with wide spectra, different composition and concentration of elements, which makes it impossible to develop universal methods applicable for every analytical research. The modelling is based on algorithm, that counts the period of time in which the sample was irradiated in nuclear reactor, providing the sample's total absorption and activity analytical peaks areas with given errors. The analytical complex was tested for low-elemental analysis (determination of Fe and Zn in vegetation samples, and Cu, Ag and Au - in technological objects). At present, the complex is applied for multielemental analysis of sediment samples. In this work, modern achievements in the analytical chemistry (measurement facilities, high-resolution detectors, IAEA and IUPAC databases) and information technology applications (Java software, database management systems (DBMS), internet technologies) are applied. Reference: 1. Tillaev T., Umaraliev A., Gurvich L.G., Yuldasheva K., Kadirova J. Specialized database for instrumental neutron activation analysis - ND INAA 1.0, The 3-rd Eurasian Conference Nuclear Science and its applications, 2004, pp.270-271.; 2. Gurvich L.G., Tillaev T., Umaraliev A. The Information-analytical database on the element contents of natural objects. The 4-th International Conference Modern problems of Nuclear Physics, Samarkand, 2003, p.337. (authors)

  12. Multiscale statistical analysis of coronal solar activity

    Gamborino, Diana; Martinell, Julio J

    2016-01-01

    Multi-filter images from the solar corona are used to obtain temperature maps which are analyzed using techniques based on proper orthogonal decomposition (POD) in order to extract dynamical and structural information at various scales. Exploring active regions before and after a solar flare and comparing them with quiet regions we show that the multiscale behavior presents distinct statistical properties for each case that can be used to characterize the level of activity in a region. Information about the nature of heat transport is also be extracted from the analysis.

  13. Service activities of chemical analysis division

    Progress of the Division during the year of 1988 was described on the service activities for various R and D projects carrying out in the Institute, for the fuel fabrication and conversion plant, and for the post-irradiation examination facility. Relevant analytical methodologies developed for the chemical analysis of an irradiated fuel, safeguards chemical analysis, and pool water monitoring were included such as chromatographic separation of lanthanides, polarographic determination of dissolved oxygen in water, and automation on potentiometric titration of uranium. Some of the laboratory manuals revised were also included in this progress report. (Author)

  14. Conference on instrumental activation analysis IAA 86

    Thirty five papers were presented at the conference held in Klucenice, Czechoslovakia from May 4 to 8, 1986. The abstracts of all papers are printed in the proceedings. The conference discussed the following problem areas: the application of activation analysis in determining elements in ores, tectites, fungi, the thyroid, the primary circuit coolant, semiconductor materials; the application of nuclear reaction analysis in determining elements in rubber and coal; the application of tracer techniques in metallurgy; the description of alpha and gamma spectrometric systems and their testing; the use of microcomputers for data processing, and the description of programs. (J.P.)

  15. Nondestructive gamma activation analysis of mineral materials

    The basic problems are described related to the use of gamma activation analysis. The applicability was studied of instrumental gamma activation analysis (IGAA) in geology. A number of minerals, rocks, marine sediments and reference materials were studied. For irradiation a betatron and a microtron were used. The results show that IGAA allows the simultaneous determination of a number of trace elements at concentrations of tenths of ppm. The results are given of comparisons made of the analytical possibilities of microtron IGAA and reactor INAA in geology. Tables show the results of the application of IGAA, the main products and parameters of photoexcitation reactions and graphically represented are the gamma spectra of measured materials. (J.B.)

  16. KFUPM fast neutron activation analysis facility

    A newly established Fast Neutron Activation Analysis facility at the Energy Research Laboratory is described. The facility mainly consists of a fast neutron irradiation station and a gamma ray counting station. Both stations are connected by a fast pneumatic sample transfer system which transports the sample from the irradiation station to the counting station in a short time of 3 s. The fast neutron activation analysis facility has been tested by measuring the 27A(n, α)24Na and 115In(n, n')115mIn cross sections at 14.8 and 2.5 MeV neutron energies, respectively. Within the experimental uncertainties, the measured cross sections for these elements agree with the published values. (orig.)

  17. Reactor neutron activation analysis of industrial materials

    The specific application of neutron activation analysis (n.a.a.) for industrial materials is demonstrated by the determination of impurities in BeO, Al, Si, Cu, Ge, GaP, GaAs, steel, and irradiated uranium. A group scheme gives an orientation about the possibilities of n.a.a. The use of different standards, methods for the measurement of low radioactivities and errors caused by recoil reaction and radiation stimulated diffusion are discussed. (author)

  18. Development of prompt gamma activation analysis

    Application of prompt gamma-activation analysis to some environmental samples and NBS's standard reference materials were examined, using NBS reactor and the technique developed by the nuclear chemistry group of the University of Maryland. Concentration of several elements, Cd, B, S, Se, Sb, Zn, Ba, Cr, Cs, Co, Si, Hf, Ce, Yb, Lu, Th, Sc, Eu, Fe, Ta and Rb, were determined by both PGAA and INAA. (author)

  19. Activation Analysis and Public Health. Survey Paper

    The technique of activation analysis has useful and distinctive applications, not yet fully recognized or exploited, in public health. Three areas of usefulness may be recognized. 1. Industrial hygiene. Activation analysis offers a simple and efficient method for assessing and controlling occupational hazards associated with the handling of toxic materials, such as compounds of arsenic and of mercury. Examination of hair and nail samples, taken at six-monthly intervals, will yield a surprising amount of information regarding the influence on occupational exposure of individual variation in working habits, and inadequacy or non-observance of hygienic rules and other prescribed safety measures. 2. Epidemiology. The advantage conferred by activation analysis lies in the possibility of rapid and accurate estimation of trace element concentrations in small samples of tissue or other materials, such as can readily be obtained from population groups large enough to be statistically significant. Surveys of this kind have interesting potentialities in relation to dental caries, cancer, cirrhosis of the liver and heart disease. 3. Recognition of essential trace elements. Surveys of trace element concentrations suggest that the variability of tissue levels among members of a population is smaller for essential trace elements than for non-essential elements. It is possible also that tissue levels show a normal distribution for essential elements and a log-normal distribution for non-essential elements. (author)

  20. Neutron Activation analysis of waste water

    An instrumental neutron activation analysis for the simultaneous determination of chlorine, bromine, sodium, manganese, cobalt, copper, chromium, zinc, nickel, antimony and iron in waste water is described. They were determined in waste water samples under normal conditions by non-destructive neutron activation simultaneously using a suitable monostandard method. Standardized water samples were used and irradiated in polyethylene ampoules at a neutron flux of 1013 cm-2 s-1 for periods of 1 minute, 1 and 10 hours. A Ge hyperpure detector was used for your activity determination, with count times of 60, 180, 300 and 600 seconds. The obtained results show than the method can be utilized for the determination of this elements without realize anything previous treatment of the samples. (Author)

  1. Nuclear data for proton activation analysis

    The activation analysis with charged particles (ChPAA), as well as proton activation analysis (PAA), mainly requires separately irradiation of thick (thicker than the range of particles) samples and standard. Therefore for simplicity of determination of traces of chemical elements by instrumental PAA the absolute activity of the radionuclides must be known. Consequently we compilated data for nuclear decays (half life, radiation energy and intensity, type of decay, saturation factor), for nuclear reactions (excitation function, threshold energy, Q-value, yields of radionuclides), for the element under study (natural isotopic abundance of the nuclide, which yields the nuclear reaction considered, molar mass), stopping power of the irradiated material and the range of the particle that are used in the calculation of the absolute activity of the radionuclides and for the resolution of a nuclear interference problems of PAA. These data are tabulated. The tables of the radionuclides are presented in dependence on increasing atomic number and radiation energy as well as on methods of the radionuclide formation. The thick target yields of analytical radionuclides are presented versus particle energy

  2. Neutron activation analysis of geological materials

    Neutron activation analysis (NAA) is an extremely sensitive, selective and precise method, which yields a wealth of elemental information from even a small-sized sample. With the recent advances in nuclear reactors and high-efficiency and high-resolution semiconductor detectors, NAA has become a powerful method for multielemental analysis. The concentration of major, minor, and trace elements vary from 1 to 4 orders of magnitude in geological materials. By varying neutron fluxes, irradiation times, decay and counting intervals and using both instrumental and radiochemical techniques in NAA, it is possible to accurately determine about 50 elements in a sample aliquant. The practical aspects of the NAA method as applied to geological materials are discussed in detail, and are demonstrated by the analysis of the United States Geological Survey (USGS) and the International Atomic Energy Agency (IAEA) standard reference geological materials. General aspects of the elemental interpretations in terrestrial samples are also discussed. (author)

  3. Instrumental neutron activation analysis of soil sample

    This paper describes the analysis of soil samples collected from 5 different location around Sungai Lui, Kajang, Selangor, Malaysia. These sample were taken at 22-24 cm from the top of the ground and were analysed using the techniques of Instrumental Neutron Activation Analysis (INAA). The analysis on soil sample taken above 22-24 cm level were done in order to determine if there is any variation in elemental contents at different sampling levels. The results indicate a wide variation in the contents of the samples. About 30 elements have been analysed. The major ones are Na, I, Cl, Mg, Al, K, Ti, Ca and Fe. Trace elements analysed were Ba, Sc, V, Cr, Mn, Ga, As, Zn, Br, Rb, Co, Hf, Zr, Th, U, Sb, Cs, Ce, Sm, Eu, Tb, Dy, Yb, Lu and La. (author)

  4. Analysis of ayurvedic medicinal leaves by instrumental neutron activation analysis

    Concentrations of 15 elements were determined in medicinally important ayurvedic medicinal leaves. Instrumental neutron activation analysis was employed for the determination of the elements viz. Na, K, Br, Sm, Cr, Zn, Th, Rb, Sr, Fe, La, Co, Ce, Cs and Eu. The samples were neutron irradiated at 100 kW TRIGA -Mainz nuclear reactor and the induced activities were measured by gamma ray spectrometry using an efficiency calibrated high resolution high purity germanium (HPGe) detector. The concentrations of these elements in the medicinal leaves and their medicinal importance are discussed. (author)

  5. Multielemental analysis of soils by instrumental neutron activation analysis

    The results of an instrumental neutron activation analysis of some elemental concentrations in different soil samples near the industrial areas at Tirupati, India, are reported. Altogether 14 elements, Sm, La, Cr, Co, Zn, Cs, Ce, Th, Rb, Na, K, Sr, Fe and Eu were determined. The samples were irradiated with neutrons at the 100 kW Triga - Mainz research reactor and the induced activities were measured by gamma-ray spectrometry using an efficiency calibrated high resolution high purity germanium (HPGe) detector in connection with a multichannel analyzer. The results are discussed. (author)

  6. Neutron activation analysis of zirconium niobium alloys

    Full text: One of the important problems in nuclear reactor projecting is the choice of constructional materials, which meet to the requirements concerned with function, technical characteristics and expected performance of the reactor construction. Also it is necessary to take into account change of their properties under the influence of intensive neutron radiation. Zirconium and zirconium-niobium alloys are used in nuclear engineering as a fuel cladding and both matrix and impurity composition have an influence on their performance capabilities.Under intensive neutron radiation high content of undesirable trace elements in constructional materials can cause forming long-lived radionuclides with high induced activity and hence severe problems may occur at service, control of the equipment and carrying out experiments. Therefore analytical control of component and impurity composition of these materials is an important problem.Neutron activation analysis (NAA) is one of multielemental and high sensitivity methods, which widely applied for the analysis of high purity materials. Prior experiments have shown that instrumental NAA is not suitable for analysis of Zr-Nb alloys due to strong induced matrix activity. Therefore we have developed radiochemical procedure for separation of impurities from matrix elements. Study of the literature data has shown that zirconium and niobium are good extracted from hydrochloric medium by 0 75 M solution of di-2-ethylhexylphosphoric acid (DEHPA) in ortho-xylene. Also this system good extracts hafnium which being accompanying element has high content and interferes with determining impurity elements. To improve separation efficiency we have used 'DEHPA - ZM HCl' chromatography system. On the basis of the carried out researches the radiochemical NAA technique for analysis of high purity zirconium and zirconium-niobium alloys has been developed. The technique is based on extraction-chromatographic separation of matrix radionuclides

  7. Determination of the Antarctic region active margin basement by using integration of the information coming from the multichannel seismic analysis and the magnetometry; Determinacao do embasamento da margen ativa da regiao Antartica pela integracao de informacoes provenientes da sismica multicanal e da magnetometria

    Torres, Luiz Carlos [Diretoria de Hidrografia e Navegacao, XX (Brazil); Gomes, Benedito Souza [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Gamboa, Luiz Antonio P. [Universidade Federal Fluminense, Niteroi, RJ (Brazil)

    1999-07-01

    Geophysical measurements were carried out in the Western Margin of the Antarctic Peninsula and Bransfield Strait by the Brazilian Antarctic Program during the summers of 1987 and 1988. The present work, using a continued seismic multi channel and magnetometry data profile crossing the area, intends to present a two-dimensional model of the interface sediment/basement and contribute to the understanding of the complex geology verified in the studying area. By this model, the main provinces of the are (Deep Ocean, South Shetland Trench, Accretionary Prism, Volcanic Arc South Shetland Islands and Bransfield Basin) could be determined. The seismic and magnetic measurements information when superposed can attribute more consistencies to the interpreted basement; although each method has its particular resolution. This way, when the seismic interpretation was not possible due to complex structures disposition, magnetic measurements could offer good estimation about basement depth. The fit between both methods (seismic and magnetic measurements) was reasonable both on the oceanic basin and in the region of Bransfield Strait. The magnetometry, as as well seismic, was sensible to the dip of Drake Plate at South Shetland Trench and the Intrusive occurrence at Bransfield Basin axis. (author)

  8. Industrial applications of neutron activation analysis

    Neutron activation analysis has been widely used in the industry and over the years played a key role in the development of manufacturing process as well as monitoring of the process flow. In this context NAA has been utilized both in R and D, and in the factory as a flexible analytical tool. It has been used successfully in numerous industries including broad categories such as Chemical, Pharmaceutical, Mining, Photographic, Oil and Gas, Automobile, Defense, Semiconductor and Electronic industries. Dow Chemical owns and operates a research reactor for analytical measurements of samples generated in both R and D, and manufacturing area in its plant in Midland, Michigan. Although most industries do not have reactors on their campus but use an off site reactor regularly, and often have in-house neutron sources such as a 252Cf used primarily for NAA. In most industrial materials analysis laboratory NAA is part of a number of analytical techniques such as ICP-MS, AA, SIMS, FTIR, XRF, TXRF etc. Analysis of complex industrial samples may require data from each of these methods to provide a clear picture of the materials issues involved. With the improvement of classical analytical techniques, and the introduction of new techniques, e.g. TXRF, the role of NAA continues to be a key bench mark technique that provides accurate and reliable data. The strength of the NAA in bulk analysis is balanced by its weakness in providing surface sensitive or spatially resolved analysis as is required by many applications. (author)

  9. Optimization of time characteristics in activation analysis

    Full text: The activation analysis temporal characteristics optimization methods developed at present are aimed at determination of optimal values of the three important parameters - irradiation time, cooling time and measurement time. In the performed works, especially in [1-5] the activation analysis processes are described, the optimal values of optimization parameters are obtained from equations solved, and the computational results are given for these parameters for a number of elements. However, the equations presented in [2] were inaccurate, did not allow one to have optimization parameters results for one element content calculations, and it did not take into account background dependence of time. Therefore, we proposed modified equations to determine the optimal temporal parameters and iteration processes for the solution of these equations. It is well-known that the activity of studied sample during measurements does not change significantly, i.e. measurement time is much shorter than the half-life, thus the processes taking place can be described by the Poisson probability distribution, and in general case one can apply binomial distribution. The equation and iteration processes use in this research describe both probability distributions. Expectedly, the cooling time iteration expressions obtained for one element analysis case are similar for the both distribution types, as the optimised time values occurred to be of the same order as half-life values, whereas the cooling time, as we observed, depends on the ratio of the studied sample's peak value to the background peak, and can be significantly larger than the half-life value. This pattern is general, and can be derived from the optimized time expressions, which is supported by the experimental data on short-living isotopes [3,4]. For the isotopes with large half-lives, up to years, like cobalt-60, the cooling time values given in the above mentioned works are equal to months which, apparently

  10. Scalable histopathological image analysis via active learning.

    Zhu, Yan; Zhang, Shaoting; Liu, Wei; Metaxas, Dimitris N

    2014-01-01

    Training an effective and scalable system for medical image analysis usually requires a large amount of labeled data, which incurs a tremendous annotation burden for pathologists. Recent progress in active learning can alleviate this issue, leading to a great reduction on the labeling cost without sacrificing the predicting accuracy too much. However, most existing active learning methods disregard the "structured information" that may exist in medical images (e.g., data from individual patients), and make a simplifying assumption that unlabeled data is independently and identically distributed. Both may not be suitable for real-world medical images. In this paper, we propose a novel batch-mode active learning method which explores and leverages such structured information in annotations of medical images to enforce diversity among the selected data, therefore maximizing the information gain. We formulate the active learning problem as an adaptive submodular function maximization problem subject to a partition matroid constraint, and further present an efficient greedy algorithm to achieve a good solution with a theoretically proven bound. We demonstrate the efficacy of our algorithm on thousands of histopathological images of breast microscopic tissues. PMID:25320821

  11. Support system for Neutron Activation Analysis

    In the research reactor of JAERI, the Neutron Activation Analysis (NAA) has been utilized as a major part of an irradiation usage. To utilize NAA, research participants are always required to learn necessary technique. Therefore, we started to examine a support system that will enable to carry out INAA easily even by beginners. The system is composed of irradiation device, gamma-ray spectrometer and data analyzing instruments. The element concentration is calculated by using KAYZERO/SOLCOI software with the K0 standardization method. In this paper, we review on a construction of this INAA support system in JRR-3M of JAERI. (author)

  12. Toxicological applications of neutron-activation analysis

    Thermal neutron-activation analysis is recognised as a useful tool for trace element studies in toxicology. This paper describes some recent applications of the technique to three elements when ingested by people in excess of normal intake Two of the elements (copper and chromium) are essential to life and one (bromine) is as yet unclassified. Three deaths were investiagted and trace element levels compared with normal levels from healthy subjects in the same geographical area who had died as a result of violence. (author)

  13. Neutron activation analysis of medicinal plant extracts

    Instrumental neutron activation analysis was applied to the determination of the elements Br, Ca, Cl, Cs, Fe, K, La, Mg, Mn, Na, Rb and Zn in medicinal extracts obtained from Centella asiatica, Citrus aurantium L., Achyrolcline satureoides DC, Casearia sylvestris, Solano lycocarpum, Zingiber officinale Roscoe, Solidago microglossa and Stryphnondedron barbatiman plants. The elements Hg and Se were determined using radiochemical separation by means of retention of Se in HMD inorganic exchanger and solvent extraction of Hg by bismuth diethyldithiocarbamate solution. Precision and accuracy of the results were evaluated by analyzing biological reference materials. The therapeutic action of some elements found in plant extracts analyzed is briefly discussed. (author). 15 refs., 5 tabs

  14. Active Shape Analysis of Mandibular Growth

    Hilger, Klaus Baggesen; Larsen, Rasmus; Kreiborg, Sven;

    2003-01-01

    This work contains a clinical validation using biological landmarks of a Geometry Constrained Diffusion registration of mandibular surfaces. Canonical Correlations Analysis is extended to analyse 3D landmarks and the correlations are used as similarity measures for landmark clustering. A novel...... Active Shape Model is proposed targeting growth modelling by applying Partial Least Squares regression in decomposing the Procrustes tangent space. Shape centroid size is applied as dependent variable but the method generalizes to handle other, both uni- and multivariate, effects probing for high...

  15. Activation Analysis and Nuclear Research in Burma

    Research endeavours in the field of Nuclear Sciences in Burma appear to be concentrated in three main Institutions. These are the Chemistry and Physics Departments of the Rangoon Arts & Science University and the Union of Burma Applied Research Institute (UBARI). In view of possible forthcoming developments an expanded research programme, which is to be implemented on the basis of a five year plan, has been drawn up. Research topics included in this programme are predominantly of practical interest and aimed at a contribution by nuclear methods, in particular activation analysis, to the technological and industrial needs of the country

  16. Activation analysis for food chemistry Pt. 3

    The nondestructive determination of K, Na, Ca, Mg, Cl and P content of animal tissues was reported. The IBR-30 (Dubna) reactor was used as the thermal neutron source for all the (n,ν) reactions needed for the analyses (tabulated), and as the source of fast neutrons for the (n,α) reaction of the P determination, too. Results and errors of the analyses (5-15%) were discussed comparing the reproducibility of the methods in case of different animal tissues, liver, bones, blood, etc. The nondestructive neutron activation multielemental analysis for food chemistry can be recommended in the case of a large scale monitoring program of food samples. (Sz.J.)

  17. Monostandard activation analysis of prehistoric copper objects

    In order to compare the detection limits of neutron activation analysis and spectral analisys, a number of eneolitic and other copper cultural objects have been investigated. A number of 12 elements could be determined by NAA in a long irradiation run, the same number as in spectral analysis. Six elements have a detection limit an order of magnitude higher than that in spectral analysis and only three have a lower detection limit (Fe, Ni, Sn). If the irradiation time is increased 4 times, only tin remains with a lower detection limit. Other three elements (Hg, Cs, Se), which were not reported in spectral analysis, can be seen with high sensitivity. An average counting time of 1 hour seems to be enough for a satisfactory statistics. No chemical processing of the sample is needed, except a slight etching and washing before or after irradiation. It is concluded that monostandard NAA is a rather simple and reliable method with a higher sensitivity compared to the spectral method

  18. Neutron activation analysis of human hair

    As a part of IAEA research project, ''Activation analysis of hair as an indicator of contamination of man by environmental trace element pollutants'', a survey was carried out to elucidate the levels of various trace element concentration in hair of local population in the Tokyo Metropolitan areas, by applying instrumental neutron activation analysis. A total of 202 scalp hair samples were collected from the inhabitants classified by sex and five age classes. Irradiation was made in the Rikkyo University 100 kW TRIGA MARK-II reactor. Using several combinations of irradiation time, cooling time and counting time, forty elements were determined. The relationship between several trace element contents in hair and such factors as sex, age class, hair treatment, smoking habit and dental treatment, was analyzed by using the method of multiple regression. It was shown that (1) Hair treatment had a predominant effect on the contents of bromine, magnesium and calcium in hair, (2) Aging and amoking contributed increasing mercury content in hair, and hair treatment acted reversely. (author)

  19. 14 MeV proton activation analysis

    A fast nuclear nondestructive method for protein analysis using the 14 MeV proton activation has been developed. The total nitrogen content was measured through the reaction: 14N (p,n) 14O, (Tsub(1/2)=71 s). The 14O activity was detected by means of its characteristic 2.312 MeV gamma-ray line with a NaI(Tl) detector. For a fast determination of a large number of samples a mechanized sistem reacting a rate of one sample per minute has been developed. The laboratory electronics comprises a multichannel analyser, a PDP computer and an electronic module comtroller. Comparison of the results obtained by the method described and the classical Kjeldal technique for samples of various cereal grains (soya bean seads, wheat, barley and corn) showed good correlation. A problem of the analysis of the whole protein region on corn and soya-bean seads, where this region is thicker (0,2 - 2 mm), is mentioned. In this case flour was proposed to be used to obtain a protein homogeneous sample and the irradiaton dose for a sample was about 33,000 Gy, mainly (99%) from protons (27 s x 100 nA x 14 MeV)

  20. Activation Analysis in Forensic Science. Survey Paper

    Recently the unique features of the activation analysis method have been utilized to advantage to meet some specialized needs in the scientific investigation of crime. A review of the principal forensic activation analysis applications to biological materials to date indicates that they may be roughly classified as: (i) the detection and determination of residues of toxic materials in foodstuffs, human tissues, sera and excreta; (ii) the 'individualization' of hair, fibres, narcotics and drugs; and (iii) investigation of the transference of ballistic material to bone, cloth or paper. Analyses of these materials in some actual forensic investigations have been perfected to the point of acceptance in the law courts of several countries. Additional and broader areas of application are under development in a number of nuclear and forensic laboratories. (i) The determination of sub microgram quantities of phosphorus compounds, arsenic, mercury, selenium and thallium in specimens from post-mortem examinations and from living persons showing symptoms of toxicity has revealed certain ingestion of abnormal amount of toxic substances by comparison with similar specimens from healthy persons. In some cases, with tissues such as hair and nails, the time scale of the ingestion of arsenic or mercury has been revealed through the distribution of the deposited element with distance from the growing end or edge. (ii) A series of feasibility studies on the possibility of distinguishing similar materials through their characteristic trace-element patterns have resulted from observations of the wide range or variation in trace impurity content in specimens which come from different individuals or different natural sources. For example, extensive activation analyses for more than twenty elements in human head hair from many people have been carried out and a statistical analysis of the results indicate that activation hair comparisons in forensic investigations may be quite definitive

  1. Elemental analysis of ancient potteries using instrumental neutron activation analysis

    The provenance studies of archaeological artifacts like potteries, bricks, and coins demands elemental analysis. Instrumental Neutron Activation Analysis (INAA) with high resolution gamma ray spectrometry was used due to its high sensitivity and simultaneous multielement capability. The ancient pottery samples belong to Melchittamur, collected from Department of Ancient History, Tamilnadu, were irradiated in KAMINI reactor, IGCAR, Kalpakkam and counted using PC based Aptec MCA card. The peak areas were obtained using peak-fit PHAST software. The elemental concentrations were calculated using relative method with IAEA RM SL-1 as comparator. The concentrations of elements K, Sc, Cr, Mn, Fe, Co, In, Cs, La, Ce, Sm, Eu, Hf and Th were determined. The % uncertainties are within 1-12% except for Cr, In, Cs and Th

  2. Research Activities involving Radioactivation Analysis in Korea

    When the Triga Mark-II Research Reactor was installed at this institute in 1960, it was furnished with a pneumatic tube, a fume hood, and a laboratory bench for the purpose of developing the utilization of the research reactor in this country. This marked the commencement of research activity in radioactivation analysis in Korea. Since the output of the reactor was not sufficient enough to perform any sophisticated fundamental research work in nuclear science, radioactivation analysis was considered as one of the most promising means of utilising the reactor. Various requests for routine analysis of the trace elements contained in Korean mineral ores, archaeological materials, domestic industrial samples, native medicinal plants, and criminological samples had been filed at this institute. Fortunately, a well trained scientist and technician for the radioactivation work had been working at this division and hence these requests from the public had been well worked out to receive much recognition of scientists and engineers both in this country and overseas. A brief summary of the research work accomplished is presented in this paper and a brief outline of the routine analytical work is also described on the basis of local situations

  3. Inorganic constituents determination in medicinal plants and their extracts; Determinacao dos constituintes inorganicos em plantas medicinais e seus extratos

    Francisconi, Lucilaine Silva

    2014-07-01

    Different types of therapies have been introduced as an alternative treatment to combat different types of human disorders. Among them, the use of herbal teas has been highlighted by the cost/benefit, easiness of acquisition and administration. The aim of this study was to determine the inorganic constituents, and evaluate the element concentrations of As, Ba, Br, Ca, Co, Cr, Cs, Fe, Hf, K, Mg. Mn, Na, Rb, Sb, Sc, Se, Ta, Th, Ti, U, V, Zn and Zr by neutron activation analysis; and Cd, Cu, Ni and Pb, by atomic emission spectrometry, with inductively coupled plasma source and Hg, by atomic absorption spectrometry, with cold vapor generation in medicinal plants and their extracts, whose marketing was recently regulated by National Health Surveillance Agency (ANVISA). The relevance of these analyses is justified by the need of contributing to the recommendation of such plants as sources of minerals in the diet and, also, to verify if their concentrations cam pose some harm to the organism. The techniques showed adequate sensitivity in determining the concentration for most of the elements. Toxic elements were found in concentration not harmful to the human body. The results, also, allowed possible to correlate the elemental concentration in the analyzed species, by the determination the correlation coefficients and applications of cluster analysis. From these results it was confirmers in the groups of elements, regarding the variation of the concentrations observed in some plants and their extracts. The elements that play important roles in the human metabolism were determined in concentrations that can help both, to avoid the lack of these elements in the organisms, from the diet, and in treatment of disease. (author)

  4. Instrumental neutron activation analysis of kidney stones

    Kidney stone samples of the types calcium oxalate, uric acid, and xanthine were analyzed for their elemental contents by neutron activation analysis to study both the elemental correlation and influence of element on stone precipitation processes. Elements, such as Al, Au, Br, Ca, Cl, Co, Cr, Fe,H, I, K, Mg, Na, Sb, Se, Sr, and Zn, were determined quantitatively. Calcium oxalate stones contained higher concentration of all the elements analyzed compared to uric acid or xanthine stones. The concentrations of Cl, Fe, K, Na, Sr, and Zn were relatively higher than Au, Co, Cr, and Sb. A positive correlation exists between Ca and Zn, whereas a negative correlation exists between Sr and Ca. Zinc may play an important role in the formation of calcium oxalate stone

  5. Neutron activation analysis of human hair

    In an attempt to study the availability and limitation of analytical data of human hair as an indicator of environmental pollution and/or of human health effect, concentrations of elements in 202 scalp hair samples collected from local population in the Tokyo Metropolitan area were determined by instrumental neutron activation analysis. The correlation coefficients between concentrations of 13 elements in each sex and in each age group were calculated and discussed. There were significant correlations between some pairs of elements, i.e. Na-K, Br-Cl, Ca-Zn and Ca-Mg, in all five age classes in both of male and female, indicating that the correlations were consistent. Ca was observed to be reversely correlated with Cl. No significant correlation was apparent between Hg and Se, when the correlation coefficient was calculated using logarithmic converted concentration data. (author)

  6. Neutron activation analysis of urinary calculi

    Urinary calculi resulting from disorders in the urinary system are mostly composed of uric acid, urates, calcium oxalate, alkaline earth phosphates (Ca and Mg), triple phosphate (magnesium ammonium phosphate), calcium carbonate, cystine, xanthine, and traces of proteins. The determination of these macro-constituents has been carried out by different analytical procedures. No attempts however, have been reported regarding the determination of trace elements in urinary stones, apart from that of Herring et al., who investigated the consumption of strontium by urolithiasis patients. The present work is a non-destructive neutron activation analysis of urinary calculi, to search the variation in concentration of certain trace elements with the chemical composition of the calculus

  7. Reactor neutron activation for multielemental analysis

    Neutron Activation Analysis using single comparator (K0 NAA method) has been used for obtaining multielemental profiles in a variety of matrices related to environment. Gold was used as the comparator. Neutron flux was characterised by determining f, the epithermal to thermal neutron flux ratio and cc, the deviation from ideal shape of the neutron spectrum. The f and a were determined in different irradiation positions in APSARA reactor, PCF position in CIRUS reactor and tray rod position in Dhruva reactor using both cadmium cut off and multi isotope detector methods. High resolution gamma ray spectrometry was used for radioactive assay of the activation products. This technique is being used for multielement analysis in a variety of matrices like lake sediments, sea nodules and crusts, minerals, leaves, cereals, pulses, leaves, water and soil. Elemental profiles of the sediments corresponding to different depths from Nainital lake were determined and used to understand the history of natural absorption/desorption pattern of the previous 160 years. Ferromanganese crusts from different locations of Indian Ocean were analysed with a view to studying the distribution of some trace elements along with Fe and Mn. Variation of Mn/Fe ratio was used to identify the nature of the crusts as hydrogenous or hydrothermal. Fe-rich and Fe-depleted nodules from Indian Ocean were analysed to understand the REE patterns and it is proposed that REE-Th associated minerals could be the potential Th contributors to the sea water and thus reached ferromanganese nodules. Dolomites (unaltered and altered), two types of serpentines and intrusive rock dolerite from the asbestos mines of Cuddapah basin were analysed for major, minor and trace elements. The elemental concentrations are used for distinguishing and characterising these minerals. From our investigations, it was concluded that both dolomite and dolerite contribute elements in the serpentinisation process. Chemical neutron

  8. Determination of elements in blood of golden hamster by NAA; Determinacao de elementos em sangue de hamster dourado usando AAN

    Aguiar, Rodrigo Oliveira de

    2009-07-01

    In the present study Neutron Activation Analysis technique has been used to determine, simultaneously, some element concentrations of clinical relevance in whole blood samples of golden hamster. The normal range for Br, Ca, Cl K, Mg, Na and S considering 2 {sigma} (Two Standard deviations) was 0.011 0.047 gL{sup -1} (Br); 0.11 0.35 gL{sup -1} (Ca); 2.11 3.75 gL{sup -1} (Cl); 1.35 2.79 gL{sup -1} (K), 0.026 0.090 gL{sup -1} (Mg), 1.03 2.51 gL{sup -1} (Na) e 0.97 2.01 gL{sup -1} (S). The knowledge of these limits became possible to perform clinical investigation in this animal model using whole blood. The comparison with the results from human being whole blood estimation (Hamster and human) became possible to check the similarities or physiologic differences, an important data for animal experimentation. (author)

  9. Neutron activation analysis of arsenic in Greece

    Arsenic is considered a toxic trace element for plant, animal, and human organisms. Arsenic and certain arsenic compounds have been listed as carcinogens by the U.S. Environmental Protection Agency. Arsenic is emitted in appreciable quantities into the atmosphere by coal combustion and the production of cement. Arsenic enters the aquatic environment through industrial activities such as smelting of metallic ores, metallurgical glassware, and ceramics as well as insecticide production and use. Neutron activation analysis (NAA) is a very sensitive, precise, and accurate method for determining arsenic. This paper is a review of research studies of arsenic in the Greek environment by NAA performed at our radioanalytical laboratory. The objectives of these studies were (a) to determine levels of arsenic concentrations in environmental materials, (b) to pinpoint arsenic pollution sources and estimate the extent of arsenic pollution, and (c) to find out whether edible marine organisms from the gulfs of Greece receiving domestic, industrial, and agricultural wastes have elevated concentrations of arsenic in their tissues that could render them dangerous for human consumption

  10. Epithermal neutron activation analysis of food

    Food samples were irradiated with thermal and epithermal neutrons. The average ratios of thermal to epithermal activity were determined for 80Br, 49Ca, 38Cl, 60mCo, 42K, 27Mg, 56Mn, 24Na, and 86mRb. They were equal to 2.1, 26, 24, 6.6, 19, 16, 11, 23 and 1.9, respectively. Then, 57 food samples were analyzed by epithermal neutron activation analysis for Br and Rb. The concentrations (in ppm) of Br and Rb were in asparagus (2) 2.3, 11.5; beets (3) 0.5, 0.8; beef (3) 1.7, 3.6; cabbage (5) 0.5, 10.8; carrot (3) 0.2, 3.7; chicken (3) 0.6, 4.4; chocolate (7) 11.1, 18.7; egg (3) 0.9, 1.9; french bean (3) 0.3, 1.0; goose (2) 1.3, 9.3; lettuce (2) 0.9, 1.7; pork (1) 1.5, 4.4; potato (7) 1.0, 1.2; sausage (3) 4.8, 3.5; spinach (3) 3.6, 4.0; strawberry jam (3) 0.4, 1.4; tomato (1) 13.5, 14.6; turkey (3) 1.2, 4.9. respectively. The number of samples and analyzed is indicated in parentheses. (author)

  11. Applications of neutron activation analysis in chemistry and pollution fields

    Some examples of applications of activation analysis are given such as: chemical analysis of precious metals, nuclear graphite and hydrocarbons; control of pollution of water and seawater, analysis of food and seafood, atmospheric, dust and hair for determination of impurities

  12. Quality assurance in neutron activation analysis

    As a potential reference method, neutron activation analysis does not have to rely on other reference materials to ascertain the quality of analytical results. The fundamental characteristics of the method with the clear separation between irradiation, processing, and counting makes possible the estimation of uncertainties of individual results from a priori assumptions. Such estimates of the standard deviation from a series of independent sources of variation are compared with the a posteriori variability of replicate determinations in order to ascertain that the analytical method is in a state of statistical control. This Analysis of Precision tests the absence of unknown errors by means of a statistic T, which is closely approximated by a chi-square distribution. In this manner an evaluation is made of a commercially available computer program for peak evaluation in γ-spectrometry, as well as of other factors affecting the precision and accuracy of the counting process. An attempt is also made to determine sampling constants of one gram or less in a candidate biological reference material

  13. Epithermal neutron activation analysis in applied microbiology

    Some results from applying epithermal neutron activation analysis at FLNP JINR, Dubna, Russia, in medical biotechnology, environmental biotechnology and industrial biotechnology are reviewed. In the biomedical experiments biomass from the blue-green alga Spirulina platensis (S. platensis) has been used as a matrix for the development of pharmaceutical substances containing such essential trace elements as selenium, chromium and iodine. The feasibility of target-oriented introduction of these elements into S. platensis biocomplexes retaining its protein composition and natural beneficial properties was shown. The absorption of mercury on growth dynamics of S. platensis and other bacterial strains was observed. Detoxification of Cr and Hg by Arthrobacter globiformis 151B was demonstrated. Microbial synthesis of technologically important silver nanoparticles by the novel actinomycete strain Streptomyces glaucus 71 MD and blue-green alga S. platensis were characterized by a combined use of transmission electron microscopy, scanning electron microscopy and energy-dispersive analysis of X-rays. It was established that the tested actinomycete S. glaucus 71 MD produces silver nanoparticles extracellularly when acted upon by the silver nitrate solution, which offers a great advantage over an intracellular process of synthesis from the point of view of applications. The synthesis of silver nanoparticles by S. platensis proceeded differently under the short-term and long-term silver action. (author)

  14. Solar active regions: a nonparametric statistical analysis

    Pelt, J; Tuominen, I

    2009-01-01

    The sunspots and other solar activity indicators tend to cluster on the surface of the Sun.These clusters very often occur at certain longitudes that persist in time.It is of general interest to find new and simple ways to characterize the observed distributions of different indicators and their behaviour in time. In the present work we use Greenwich sunspot data to evaluate statistical but not totally coherent stability of sunspot distribution along latitudes as well as longitudes. The aim was to obtain information on the longitudinal distribution of the underlying spot-generating mechanism rather than on the distribution and migration of sunspots or sunspot groups on the solar surface. Therefore only sunspot groups were included in the analysis, and only the time of their first appearance was used. We use simple nonparametric approach to reveal sunspot migration patterns and their persistency. Our analysis shows that regions where spots are generated tend to rotate differentially as the spots and spot group...

  15. Applications of neutron activation analysis technique

    The technique was developed as far back as 1936 by G. Hevesy and H. Levy for the analysis of Dy using an isotopic source. Approximately 40 elements can be analyzed by instrumental neutron activation analysis (INNA) technique with neutrons from a nuclear reactor. By applying radiochemical separation, the number of elements that can be analysed may be increased to almost 70. Compared with other analytical methods used in environmental and industrial research, NAA has some unique features. These are multi-element capability, rapidity, reproducibility of results, complementarity to other methods, freedom from analytical blank and independency of chemical state of elements. There are several types of neutron sources namely: nuclear reactors, accelerator-based and radioisotope-based sources, but nuclear reactors with high fluxes of neutrons from the fission of 235U give the most intense irradiation, and hence the highest available sensitivities for NAA. In this paper, the applications of NAA of socio-economic importance are discussed. The benefits of using NAA and related nuclear techniques for on-line applications in industrial process control are highlighted. A brief description of the NAA set-ups at CERT is enumerated. Finally, NAA is compared with other leading analytical techniques

  16. 7th international conference ''Modern trends in activation analysis''

    The conference was held on 23-27 June, 1986 in Copenhagen (DK) with the participation of specialists from 42 countries. 175 papers were submitted covering the wide field of applications of neutron activation analysis, from novel techniques to sample preparation, information processes and control, activation techniques, light element and rare earth element determination, ultratracer analysis, quality assurance, comparator methods, and reference materials. The poster session was mainly oriented to industrial applications of activation analysis, biological applications, in vivo use of neutron activation analysis, the applications of neutron activation analysis in environmental control, criminology, etc. (E.S.)

  17. Activation analysis in Europe: present and future perspectives

    A survey is given of the present-day European contribution to activation analysis, covering neutron activation analysis (NAA), charged particle activation analysis (CPAA) and photon activation analysis (PAA). Attention is paid to the available irradiation facilities, in particular nuclear reactors, cyclotrons and Van de Graaff accelerators, and linear electron accelerators. Mention is made of progress in fundamental fields, but the attention is especially focussed on practical applications: environmental, geochemical/cosmochemical, biological/medical, and high-purity materials. Eventually, the role of activation analysis in research projects of the Commission of the European Communities (CEC) and in the Reference Materials program of the Community Bureau of Reference (BCR) is emphasized

  18. Operating cost analysis of anaesthesia: Activity based costing (ABC analysis

    Majstorović Branislava M.

    2011-01-01

    Full Text Available Introduction. Cost of anaesthesiology represent defined measures to determine a precise profile of expenditure estimation of surgical treatment, which is important regarding planning of healthcare activities, prices and budget. Objective. In order to determine the actual value of anaestesiological services, we started with the analysis of activity based costing (ABC analysis. Methods. Retrospectively, in 2005 and 2006, we estimated the direct costs of anestesiological services (salaries, drugs, supplying materials and other: analyses and equipment. of the Institute of Anaesthesia and Resuscitation of the Clinical Centre of Serbia. The group included all anesthetized patients of both sexes and all ages. We compared direct costs with direct expenditure, “each cost object (service or unit” of the Republican Health-care Insurance. The Summary data of the Departments of Anaesthesia documented in the database of the Clinical Centre of Serbia. Numerical data were utilized and the numerical data were estimated and analyzed by computer programs Microsoft Office Excel 2003 and SPSS for Windows. We compared using the linear model of direct costs and unit costs of anaesthesiological services from the Costs List of the Republican Health-care Insurance. Results. Direct costs showed 40% of costs were spent on salaries, (32% on drugs and supplies, and 28% on other costs, such as analyses and equipment. The correlation of the direct costs of anaestesiological services showed a linear correlation with the unit costs of the Republican Healthcare Insurance. Conclusion. During surgery, costs of anaesthesia would increase by 10% the surgical treatment cost of patients. Regarding the actual costs of drugs and supplies, we do not see any possibility of costs reduction. Fixed elements of direct costs provide the possibility of rationalization of resources in anaesthesia.

  19. Analysis of human enamel and dentine by neutron activation analysis

    Determination of trace elements in dental tissues has been of great interest to study the correlation between element composition and caries as well as food habits of individuals. In the present study dentine and enamel samples from healthy individuals were analysed by neutron activation analysis. The teeth were provided form dental clinics, and they were previously washed using purified water and acetone. Then they were dried at 40 deg C and ground in a agate mortar. The samples and element standards were irradiated with thermal neutrons at the IEA-R1 nuclear reactor. Long irradiations of 8 h under thermal neutron flux of 5x1012 n cm-2 s-1 were used for Ca, Na, Sr and Zn determinations. In short irradiations of 15 s and under neutron flux of 1012 n cm-2 s-1 the elements Mg, Mn, Na e Sr were determined. The induced gamma activities of the samples and standards were measured using a hyperpure Ge detector coupled to a gamma ray spectrometer. Elemental concentrations were calculated by comparative method. Results obtained showed that Ca, Mg and Na are present in both tissues at the level of percentages and the elements Mn, Sr and Zn at the μg g-1 levels. For quality control of the results the certified reference materials NIST 1400 Bone Ash and NIST 1486 Bone Meal were analysed. (author)

  20. Simultaneous speciation analysis using neutron activation

    Full text: Neutron activation analysis (NAA) is a well-established analytical technique for the simultaneous determination of multielement concentrations. Although various forms of NAA have been traditionally applied to measuring the total concentrations of elements, the scope of NAA can be further extended in conjunction with pre-irradiation chemical separations to determine the species of an element. The technique can then be called speciation NAA (SNAA). Since much of the toxicity of an element depends on its physico-chemical forms, there is an increasing interest in studying its speciation. A number of characteristic features of NAA, which other techniques normally do not possess, can be advantageously exploited in SNAA. For example, SNAA has simultaneous multielement specificity unlike AAS and AFS. The SNAA technique can be applied to the simultaneous speciation of elements which are not chemically similar such as Cd, Se and I, as well as to the elements such as Cl, Br and I which are rather difficult to determine by most other techniques. Qualitative as well as quantitative analysis of small samples can be done by SNAA with excellent precision, accuracy, sensitivity, and rapidity. Unlike many other techniques, SNAA has some enhanced quality assurance capabilities. We have developed SNAA methods for separating various inorganic and organic arsenic species in water and in sea foods. We are presently extending these methods to include simultaneous speciation of As, Sb and Se. We have also developed SNAA methods employing biochemical techniques for the characterization of metalloproteins and protein-bound trace element species of Se along with Cd, Cu, Mn, Mo and Zn in bovine kidneys. Lately, we have concentrated our efforts to develop SNAA methods in conjunction with HPLC, RPC, SEC, NMR and MS for the simultaneous separation and characterization of extractable organo chlorine, organo bromine and organo iodine species in fisheries samples. An overview of the

  1. Activation analysis for the Ignitor tokamak

    The purpose of the Ignitor experiment is to produce DT plasma regimes where ignition can take place. From the neutronics point of view, after a first period of machine set up and tuning in aneutronic operation, a second phase of 2.5 MeV neutron production with pure deuterium plasmas at increasing density is anticipated. After that, a transition phase to increasing percentage of tritium will be followed by several years of operations with 50% of tritium leading to short but intense 14-MeV neutron emission. To deal with the concerns due to the strong neutron emission, a detailed description of the actual Ignitor machine is implemented in the MCNP-4B Monte Carlo code to calculate the neutron fluxes in all machine components, taking in account the streaming through the ports. These fluxes are then used as input for the FISPACT-97 code for the analysis of the activation at the end of life and at intermediate times for safety assessment purposes. The resulting dose rate outside the device is also studied. The results point out that remote handling is needed for repair/maintenance of inner components following the DD operations, and that the access in the hall near the device could be restricted from the beginning of DT operations. The requirements on additional shield are discussed

  2. Neutron activation analysis applied to archaeological problems

    Among the various techniques, the main analytical methods used to characterize ceramics are undoubtedly XRF and INAA. The principles of NAA differ from those of XRF in that samples are irradiated by thermal neutrons from a nuclear reactor. During irradiation, a few neutrons are captured by the nuclei of atoms in the specimen. This process, called activation, causes some of the nuclei to become unstable. During and after neutron irradiation, these unstable nuclei emit γ rays with unique energies at rates defined by the characteristic half-lives of the radioactive nuclei. Identification of the radioactive nucleus is possible by measuring the γ ray energies. Determination of their intensities permits quantitative analysis of the elements in the sample. The use of NAA in ceramics by a combination of two or three irradiation, decay and measurement strategies allows the determination of the elements Ba, Ce, Cl, Co, Cs, Dy, Eu, Fe, Hf, K, La, Lu, Mn, Na, Nd, Rb, Sb, Sc, Sm, Sr, Ta, Tb, Th, U, Yb, Zn and Zr, if necessary by changing the irradiation, decay and measurement schemes. In general, XRF is more available, more rapid and less expensive than NAA. However, NAA offers a far greater number of elements, more sensitivity, superior precision and greater accuracy than XRF. On the other hand, NAA can be performed on extremely small samples (5-10 mg), meaning that only minor damage to valuable artefacts may be required

  3. Neutron-activation analysis of plant materials

    The possibilities offered by non-destructive neutron activation analysis (NAA) for simultaneously determining a large number of micro- and macro-components in plant samples of Bulgarian origin have been studied. Three groups of elements are determined: short half-life isotopes: Al, Mg, Ca, Na, Mn, Cl, Cu; medium half-life isotopes: Br, Na, K; and long half-life isotopes: Fe, Cr, Co, Sc, Pb, Zn. The samples are kept for 1 minute in a fluxes of 6x1012 n.cm2.sec-1 (first group), and of 3x1011 n.cm2.sec-1 for 18 hours (second and third groups). Use is made of a Ge/Li detector and 4000-channel analyser. To test the accuracy of the method, the results of NAA for some standard specimens have been compared with the indicators of other conventional methods tested in 18 laboratories in various countries. The data from NAA for the content of K, Mo, Ca, Mn, Fe, Zn and Cu demonstrate a high degree of coincidence with those from the other methods. Chemical composition of 23 samples of experimental and field crops is determined

  4. Probabilistic Models of Analysis of Loan Activity of Internet Banking

    Kondrateva Irina G.; Ostapenko Irina N.

    2012-01-01

    In article the main advantages of electronic banking in comparison with traditional, methods of the analysis of credit activity are considered. The special role is taken to the probabilistic method of analysis of credit activity in the Internet-bank. Modeling of activity of bank on the basis of probabilistic models of credit operations.

  5. Selected industrial and environmental applications of neutron activation analysis

    A review of the applications of Instrumental Neutron Activation Analysis (INAA) in the industrial and environmental fields is given. Detection limits for different applications are also given. (author)

  6. The status of activation analysis in archaeology and geochemistry

    Many of the initial applications for activation analysis occurred in the fields of archaeology, geochemistry and cosmochemistry. In addition to the desire to investigate noteworthy problems of interest to these disciplines, the reasons for employing activation analysis were based on the advantages of sample preparation, sensitivity, multi-element capability, and non-destructiveness. Nearly fifty years later and despite the development of several new analytical methods, many of these same advantages continue to attract interest in activation analysis from these same disciplines. Past, present and future role of activation analysis with regard to research questions in archaeology, geochemistry, and cosmochemistry are overviewed. (author)

  7. High-Throughput Analysis of Enzyme Activities

    Guoxin Lu

    2007-12-01

    High-throughput screening (HTS) techniques have been applied to many research fields nowadays. Robot microarray printing technique and automation microtiter handling technique allows HTS performing in both heterogeneous and homogeneous formats, with minimal sample required for each assay element. In this dissertation, new HTS techniques for enzyme activity analysis were developed. First, patterns of immobilized enzyme on nylon screen were detected by multiplexed capillary system. The imaging resolution is limited by the outer diameter of the capillaries. In order to get finer images, capillaries with smaller outer diameters can be used to form the imaging probe. Application of capillary electrophoresis allows separation of the product from the substrate in the reaction mixture, so that the product doesn't have to have different optical properties with the substrate. UV absorption detection allows almost universal detection for organic molecules. Thus, no modifications of either the substrate or the product molecules are necessary. This technique has the potential to be used in screening of local distribution variations of specific bio-molecules in a tissue or in screening of multiple immobilized catalysts. Another high-throughput screening technique is developed by directly monitoring the light intensity of the immobilized-catalyst surface using a scientific charge-coupled device (CCD). Briefly, the surface of enzyme microarray is focused onto a scientific CCD using an objective lens. By carefully choosing the detection wavelength, generation of product on an enzyme spot can be seen by the CCD. Analyzing the light intensity change over time on an enzyme spot can give information of reaction rate. The same microarray can be used for many times. Thus, high-throughput kinetic studies of hundreds of catalytic reactions are made possible. At last, we studied the fluorescence emission spectra of ADP and obtained the detection limits for ADP under three different

  8. Neutron activation analysis of wheat samples

    Galinha, C. [CERENA-IST, Technical University of Lisbon, Av. Rovisco Pais 1, 1049-001 Lisboa (Portugal); Instituto Tecnoclogico e Nuclear, URSN, E.N. 10, 2686-953 Sacavem (Portugal); Anawar, H.M. [Instituto Tecnoclogico e Nuclear, URSN, E.N. 10, 2686-953 Sacavem (Portugal); Freitas, M.C., E-mail: cfreitas@itn.pt [Instituto Tecnoclogico e Nuclear, URSN, E.N. 10, 2686-953 Sacavem (Portugal); Pacheco, A.M.G. [CERENA-IST, Technical University of Lisbon, Av. Rovisco Pais 1, 1049-001 Lisboa (Portugal); Almeida-Silva, M. [Instituto Tecnoclogico e Nuclear, URSN, E.N. 10, 2686-953 Sacavem (Portugal); Coutinho, J.; Macas, B.; Almeida, A.S. [INRB/INIA-Elvas, National Institute of Biological Resources, Est. Gil Vaz, 7350-228 Elvas (Portugal)

    2011-11-15

    The deficiency of essential micronutrients and excess of toxic metals in cereals, an important food items for human nutrition, can cause public health risk. Therefore, before their consumption and adoption of soil supplementation, concentrations of essential micronutrients and metals in cereals should be monitored. This study collected soil and two varieties of wheat samples-Triticum aestivum L. (Jordao/bread wheat), and Triticum durum L. (Marialva/durum wheat) from Elvas area, Portugal and analyzed concentrations of As, Cr, Co, Fe, K, Na, Rb and Zn using Instrumental Neutron Activation Analysis (INAA) to focus on the risk of adverse public health issues. The low variability and moderate concentrations of metals in soils indicated a lower significant effect of environmental input on metal concentrations in agricultural soils. The Cr and Fe concentrations in soils that ranged from 93-117 and 26,400-31,300 mg/kg, respectively, were relatively high, but Zn concentration was very low (below detection limit <22 mg/kg) indicating that soils should be supplemented with Zn during cultivation. The concentrations of metals in roots and straw of both varieties of wheat decreased in the order of K>Fe>Na>Zn>Cr>Rb>As>Co. Concentrations of As, Co and Cr in root, straw and spike of both varieties were higher than the permissible limits with exception of a few samples. The concentrations of Zn in root, straw and spike were relatively low (4-30 mg/kg) indicating the deficiency of an essential micronutrient Zn in wheat cultivated in Portugal. The elemental transfer from soil to plant decreases with increasing growth of the plant. The concentrations of various metals in different parts of wheat followed the order: Root>Straw>Spike. A few root, straw and spike samples showed enrichment of metals, but the majority of the samples showed no enrichment. Potassium is enriched in all samples of root, straw and spike for both varieties of wheat. Relatively to the seed used for cultivation

  9. Neutron activation analysis of wheat samples

    The deficiency of essential micronutrients and excess of toxic metals in cereals, an important food items for human nutrition, can cause public health risk. Therefore, before their consumption and adoption of soil supplementation, concentrations of essential micronutrients and metals in cereals should be monitored. This study collected soil and two varieties of wheat samples-Triticum aestivum L. (Jordao/bread wheat), and Triticum durum L. (Marialva/durum wheat) from Elvas area, Portugal and analyzed concentrations of As, Cr, Co, Fe, K, Na, Rb and Zn using Instrumental Neutron Activation Analysis (INAA) to focus on the risk of adverse public health issues. The low variability and moderate concentrations of metals in soils indicated a lower significant effect of environmental input on metal concentrations in agricultural soils. The Cr and Fe concentrations in soils that ranged from 93-117 and 26,400-31,300 mg/kg, respectively, were relatively high, but Zn concentration was very low (below detection limit Fe>Na>Zn>Cr>Rb>As>Co. Concentrations of As, Co and Cr in root, straw and spike of both varieties were higher than the permissible limits with exception of a few samples. The concentrations of Zn in root, straw and spike were relatively low (4-30 mg/kg) indicating the deficiency of an essential micronutrient Zn in wheat cultivated in Portugal. The elemental transfer from soil to plant decreases with increasing growth of the plant. The concentrations of various metals in different parts of wheat followed the order: Root>Straw>Spike. A few root, straw and spike samples showed enrichment of metals, but the majority of the samples showed no enrichment. Potassium is enriched in all samples of root, straw and spike for both varieties of wheat. Relatively to the seed used for cultivation, Jordao presented higher transfer coefficients than Marialva, in particular for Co, Fe, and Na. The Jordao and Marialva cultivars accumulated not statistically significant different

  10. Karyotype Analysis Activity: A Constructivist Learning Design

    Ahmed, Noveera T.

    2015-01-01

    This classroom activity is based on a constructivist learning design and engages students in physically constructing a karyotype of three mock patients. Students then diagnose the chromosomal aneuploidy based on the karyotype, list the symptoms associated with the disorder, and discuss the implications of the diagnosis. This activity is targeted…

  11. Detailed Analysis of Motor Unit Activity

    Nikolic, Mile; Sørensen, John Aasted; Dahl, Kristian; Krarup, Christian

    System for decomposition of EMG signals intotheir constituent motor unit potentials and their firing patterns.The aim of the system is detailed analysis ofmotor unit variability.......System for decomposition of EMG signals intotheir constituent motor unit potentials and their firing patterns.The aim of the system is detailed analysis ofmotor unit variability....

  12. Development of educational program for neutron activation analysis

    This technical report is developed to apply an educational and training program for graduate student and analyst utilizing neutron activation analysis. The contents of guide book consists of five parts as follows; introduction, gamma-ray spectrometry and measurement statistics, its applications, to understand of comprehensive methodology and to utilize a relevant knowledge and information on neutron activation analysis

  13. International conference activation analysis and its applications (ICAAA): abstracts

    International conference on the Activation Analysis and its Applications was hold in Beijing of China on October 15-19, 1990. It was organized and co-sponsored by Division of Activation Analysis and Radioanalysis, National Natural Science Foundation of China and China Nuclear Society, etc.. 159 pieces of Articles in the field were received in the conference, from many countries

  14. Trace Analysis of Ancient Gold Objects Using Radiochemical Neutron Activation

    Olariu, A; Constantinescu, O; Badica, T; Popescu, I V; Besliu, C; Leahu, D; Olariu, Agata; Constantinescu, Mioara; Leahu, Doina

    1999-01-01

    Radiochemical neutron activation analysis has been applied to investigate the microelements in gold samples with archaeological importance. Chemical separation has allowed the determination of traces of Ir, Os, Sb, Zn, Co, Fe, Ni. Instrumental neutron activation analysis has been used for the determination of Cu.

  15. Development of educational program for neutron activation analysis

    Chung, Yong Sam; Moon, Jong Hwa; Kim, Sun Ha; Ryel, Sung; Kang, Young Hwan; Lee, Kil Yong; Yeon, Yeon Yel; Cho, Seung Yeon

    2000-08-01

    This technical report is developed to apply an educational and training program for graduate student and analyst utilizing neutron activation analysis. The contents of guide book consists of five parts as follows; introduction, gamma-ray spectrometry and measurement statistics, its applications, to understand of comprehensive methodology and to utilize a relevant knowledge and information on neutron activation analysis.

  16. Large sample neutron activation analysis of a ceramic vase

    Stamatelatos, I.E.; Tzika, F.; Vasilopoulou, T.; Koster-Ammerlaan, M.J.J.

    2010-01-01

    Large Sample Neutron Activation Analysis (LSNAA) was applied to perform non-destructive elemental analysis of a ceramic vase. Appropriate neutron self-shielding and gamma ray detection efficiency calibration factors were derived using Monte Carlo code MCNP5. The results of LSNAA were compared against Instrumental Neutron Activation Analysis (INAA) results and a satisfactory agreement between the two methods was observed. The ratio of derived concentrations between the two methods was within 0...

  17. Teaching-Learning Activity Modeling Based on Data Analysis

    Kyungrog Kim

    2015-03-01

    Full Text Available Numerous studies are currently being carried out on personalized services based on data analysis to find and provide valuable information about information overload. Furthermore, the number of studies on data analysis of teaching-learning activities for personalized services in the field of teaching-learning is increasing, too. This paper proposes a learning style recency-frequency-durability (LS-RFD model for quantified analysis on the level of activities of learners, to provide the elements of teaching-learning activities according to the learning style of the learner among various parameters for personalized service. This is to measure preferences as to teaching-learning activity according to recency, frequency and durability of such activities. Based on the results, user characteristics can be classified into groups for teaching-learning activity by categorizing the level of preference and activity of the learner.

  18. HPTLC Analysis, Antioxidant and Antigout Activity of Indian Plants

    Nile, Shivraj Hariram; Park, Se Won

    2014-01-01

    The HPTLC analysis, antioxidant, and antigout activity of Asparagus racemosus, Withania somnifera, Vitex negundo, Plumbago zeylanica, Butea monosperma and Tephrosia purpurea extracts were investigated. The chemical fingerprinting were carried out by high performance thin layer chromatography (HPTLC), antioxidant activity by ABTS, DPPH, FRAP radical scavenging assays, and antiogout activity by cow milk xanthine oxidase. The HPTLC fingerprint qualitatively revealed predominant amount of flavono...

  19. Faculty Activity Analysis in the Universidad Tecnica Del Estado Campuses.

    Karadima, Oscar

    An analysis of academic activities of college faculty at the eight campuses of Chile's Universidad Tecnica del Estado was conducted. Activities were grouped into seven categories: direct teaching, indirect teaching, research, community services, faculty development, academic administration, and other activities. Following the narrative…

  20. Insurer’s activity as object of economic analysis

    O.O. Poplavskiy

    2015-12-01

    Full Text Available The article is devoted to the substantiation of theoretical fundamentals of insurer’s analysis and peculiarities of its implementation. The attention has been focused on the important role of economic analysis in economic science which is confirmed by its active use in research and practical orientation. The author summarizes the classification and principles of insurer’s activity analysis, supplements it with specific principles for insurer’s environment, publicity and risk-orientation which enable increasingly to take into account the peculiarities of insurance relations. The paper pays attention to the specification of elements of analysis and its key directions including the analysis of insurer’s financing, the analysis of insurance operations and the analysis of investment activity which will allow the effective functioning of risk management system.

  1. Design professional activity analysis in design management

    Claudia de Souza Libanio

    2013-08-01

    Full Text Available Design use perception, as an essential element for achieving competitive advantage, also suggests the need to manage the design activities in companies. However, a few is discussed about the activity of these design professionals who participate in this process, their roles, functions and competencies, including  their connections to a company and other involved sectors. This article aims to analyze, during the design management processes, the work relations of design professionals connected to organizations both internal and externally, in order to comprehend the structure and intervenient factors on the activity of these professionals, as well as the interactions with their main coworkers. The methodology was exploratory and qualitative, using in-depth interviews with three design professionals. Subsequently, the responses were analyzed allowing the comparison of these obtained data to the theoretical bases researched. Through this case study, it was possible to realize the aspects and the structure of the design professional activity, connected intern and externally to organizations, as well as its relations with the main coworkers.

  2. ESAA environment for seismic activity analysis

    ESAA is an X-window based, graphical and interactive, software system for analyzing seismic activity, using the earthquake catalogues of a given region as input. Basic design idea and structure of this system, as well as the progress in its implementation are reported. (author). 12 refs

  3. Microscopic Analysis of Activated Sludge. Training Manual.

    Office of Water Program Operations (EPA), Cincinnati, OH. National Training and Operational Technology Center.

    This training manual presents material on the use of a compound microscope to analyze microscope communities, present in wastewater treatment processes, for operational control. Course topics include: sampling techniques, sample handling, laboratory analysis, identification of organisms, data interpretation, and use of the compound microscope.…

  4. Determination of radioactive materials in granite used as ornamental rocks; Determinacao de materiais radioativos em granitos utilizados como rochas ornamentais

    Salas, Humberto Terrazas; Barbosa, Joao Batista Santos; Murta, Clecio Campi; Rocha, Francisco de Assis [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil)). E-mail: salasht@urano.cdtn.br; Nalini Junior, Herminio Arias; Mendes, Julio Cesar [Ouro Preto Univ., MG (Brazil). Escola de Minas. Dept. de Geologia

    2000-07-01

    For environment quality control, either in a global or regional perspective, the determination of the radioactivity present in the minerals of rocks must be included. This control is carried out through specific analysis, applied to all geological materials used in civil architecture design and other applications (e.g. artistic). To date, the radioactivity of rocks has not been specifically studied, from which an adequate and comprehensive systematics is applied, in order to determine the radioactive minerals and their corresponding alterations. In Brazil, the industry of ornamental rocks is continually increasing at high rates, with a growing variety of rocks being commercialized locally as well as abroad. To a certain extent, the technical characterization of these rocks, through standard procedures defined by standardization institutions, is already available worldwide. However, among the petrographic properties specified for these rocks, minor or accessory minerals (less than 1%) are not adequately determined and detected. Among these components are radioactive minerals and, occasionally, carriers of precious metals, rare earths and other economically important minerals. (author)

  5. Evaluation of methods for wax determination in crude oil; Avaliacao de metodos de determinacao de parafinas em petroleo

    Dias, Julio Cesar M.; Silva, Maria do Socorro A.J. da; Vasconcellos, Rosa C.U. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas; Tamanqueira, Juliana B. [Fundacao Gorceix, Ouro Preto, MG (Brazil)

    2008-07-01

    Determining the wax content of crude oil is of great importance for petroleum industry, especially for production, storage and transportation of crude oils. Many different methodologies of wax determining are available in the technical literature. However, the selection of the most suitable method must be in accordance with the aim of the analysis and observing the specificities of each technique. The purpose of this work was to determine the performance of different techniques of wax determining applied to characterization of precipitation properties of waxy compounds in crude oils. Twelve samples of crude oils proceeding from the main Brazilian oil producing sedimentary basins were selected for this study. These samples were analyzed by three important analytical techniques of wax determining: precipitation by cooled solvent; liquid chromatography with precipitation by cooled solvent; and liquid chromatography followed by gas chromatography. Differential scanning calorimetry data related to the wax crystallization in these oils were used as parameters of validation. The results obtained in this study indicate that the liquid chromatography followed by gas chromatography method has the best performance for wax determining in crude oils. (author)

  6. Neutron activation analysis of geothermal water

    Instrumental technique of determination of 16 microimpurities in geothermal water samples is worked out. Probes and standard samples with cadmium filter have been irradiated by the thermal neutron flux of 5x1013 neutr.xcm-2xc-1. Cadmium filter permitted to considerably decrease 24Na radio activity caused by its high content in geothermal water, and to measure radioactivity in several hours after irradiation. Radioactivity measurement has been carried out without probe unpacking

  7. ANALYSIS OF ECOLOGICAL ACTIVITY OF PODLASIE PROVINCE

    Agnieszka Kisło; Iwona Skoczko

    2014-01-01

    The beginning of the period where the impact of human activity took dangerous size is considered to be 40 years of the nineteenth century. Then the large-scale production of electricity increased production of metallurgical industry and transport development. Significant changes contributed to rapid population growth and urbanization and industrialization processes. Man by intensive exploitation reduces or completely exhausted most natural resources. This has resulted in the availability crit...

  8. TIBER activation analysis: Appendix A-3

    TIBER-II is an engineering test reactor designed to establish the technical feasibility for fusion, and is a US option for the prospective International Thermonuclear Test Reactor (ITER). The TIBER-II baseline design has 3 m major radius, 3.6 aspect ratio, and 1.1 MW/m2 average neutron wall loading. The inboard shield is about .5 m thick and structurally consists of tungsten alloy and PCA alloy. The outboard is 1.52 m thick and utilizes PCA as structure and beryllium as a neutron multiplier. An aqueous solution of 160 g LiNO3/liter is used throughout as a coolant and breeder. A one-dimensional cylindrical model for TIBER is used to calculate the neutron flux and the radioactivities. Activities are calculated during and after 2.5 full power years (FPY) of operation. TIBER total activity is ∼2 MCi/cm at the end of operation and is dominated by the inboard activity. The high volumetric fraction of the PCA/W alloys in the inboard shield, used to provide magnet protection at the limited inboard space, makes the inboard specific activity two orders of magnitude higher than that of the outboard and dominant all the time. The decay heat due to β and γ decay produces about .05 W/cc in the inboard at shutdown and for a few weeks. Under adiabatic conditions, this heat would raise the inboard shield temperature up to 11500C. A considerable part of this heat is generated by the γ decay which might help, through the γ transport, to smooth the heat concentration. Waste disposal ratings of the TIBER structures have been calculated, and it is found that both the inboard and the outboard shield are classified as Class C radwaste. 4 refs., 4 figs., 3 tabs

  9. Regulatory activities of government: analysis of determinants

    Primož Pevcin

    2006-12-01

    Full Text Available International comparisons show that large cross-country differences exist in the overall macro extent of regulation of the economy. In this context, the main purpose of the article is to investigate, why such differences exist by identifying and empirically verifying the effect of various factors that could potentially shape those differences. Empirical analysis based on the sample of 32 developed and democratic countries revealed that almost 70 % of variation in the macro extent of regulation could be explained with 7 statistically significant explanatory variables. The econometric analysis revealed that the macro extent of regulation decreases with income inequality in society, with the level of economic development, with the sizeof economy, with the share of transfer spending in GDP and with the share of government employment in labour force. On the other hand, the extent of regulation is positively related to government ownership of enterprises and to presidential political regime

  10. Acquisition Path Analysis as a Collaborative Activity

    In the International Atomic Energy Agency, acquisition path analysis (APA) is indispensable to safeguards implementation. It is an integral part of both State evaluation process and the development of State level safeguards approaches, all performed through ongoing collaborative analysis of all available safeguards relevant information by State evaluation groups (SEG) with participation of other contributors, as required. To perform comprehensive State evaluation, to develop and revise State-level safeguards approaches, and to prepare annual implementation plans, the SEG in its collaborative analysis follows accepted safeguards methodology and guidance. In particular, the guide ''Performing Acquisition Path Analysis for the Development of a State-level Safeguards Approach for a State with a CSA'' is used. This guide identifies four major steps of the APA process: 1. Consolidating information about the State's past, present and planned nuclear fuel cycle-related capabilities and infrastructure; 2. Identifying and visually presenting technically plausible acquisition paths for the State; 3. Assessing acquisition path steps (State's technical capabilities and possible actions) along the identified acquisition paths; and 4. Assessing the time needed to accomplish each identified technically plausible acquisition path for the State. The paper reports on SEG members' and other contributors' experience with APA when following the above steps, including the identification of plausible acquisition pathways, estimation of time frames for all identified steps and determination of the time needed to accomplish each acquisition path. The difficulties that the SEG encountered during the process of performing the APA are also addressed. Feedback in the form of practical suggestions for improving the clarity of the acquisition path step assessment forms and a proposal for software support are also included. (author)

  11. Rapid radiochemical separations in neutron activation analysis

    Rapid radiochemical separation procedures based on the removal of metal ions by columns of C18-bonded silica gel after selective complexation are examined and the simplicity of the method demonstrated by its application to the determination of Mn, Cu and Zn in neutron-activated biological material. The method is rapid and reliable and readily adaptable in all radiochemical laboratories. An alternative separation procedure for selenium in blood plasma involving desalination and concentration of the selenium protein complex by gel filtration or ultrafiltration is briefly discussed. (author)

  12. Active vision in satellite scene analysis

    Naillon, Martine

    1994-01-01

    In earth observation or planetary exploration it is necessary to have more and, more autonomous systems, able to adapt to unpredictable situations. This imposes the use, in artificial systems, of new concepts in cognition, based on the fact that perception should not be separated from recognition and decision making levels. This means that low level signal processing (perception level) should interact with symbolic and high level processing (decision level). This paper is going to describe the new concept of active vision, implemented in Distributed Artificial Intelligence by Dassault Aviation following a 'structuralist' principle. An application to spatial image interpretation is given, oriented toward flexible robotics.

  13. Nondestructive neutron activation analysis of mineral materials. III

    A description is presented of sampling, calibration standards, the method of activation and measurement, activation product identification, the respective nuclear reactions, interfering admixtures, and pre-activation operations. The analysis is described of sulphides, halogenides, oxides, sulphates, carbonates, phosphates, silicates, aluminosilicates, composite minerals containing lanthanides, rocks, tektites, meteors, and plant materials. The method allows determining mainly F, Mg, Al, Ti, V, Nb, Rh, and I which cannot be determined by long-term activation (LTA). It is more sensitive than LTA in determining Ca, Cu, In, and Dy. The analysis takes less time, irradiation and measurement are less costly. The main mineral components are quickly found. (M.K.)

  14. Neutron activation analysis of ancient silver coins

    The amounts of gold and copper present as impurities in 500 Creek silver coins of the fifth century B.C. have been determined with a gamma-ray spectrometer, following neutron activation. The coinage from eight cities and kingdoms was studied; the average gold-content for different groups of coins varies between 0.02% and 0.3%, and the copper content between 0.1% and 10%. Evidence about trading connexions and of deliberate debasements of the coinage has been obtained, and several unsuspected plated coins were detected. The gold content was determined by measuring the intensity of the 0.411 MeV gamma-ray from Au198 (2.69 d); for the copper content the 0.511 MeV positron annihilation radiation from Cu64 (12.8 h) was used, and for silver the 0.884 MeV gamma-ray from Ag110m (253 d). Decay measurements were used as a check of identity. The technique of using total gamma-activity decay curves by themselves is insufficiently sensitive. For accurate work, the importance of approximate facsimile standards is stressed. (author)

  15. Nuclear power company activity based costing management analysis

    With Nuclear Energy Industry development, Nuclear Power Company has the continual promoting stress of inner management to the sustainable marketing operation development. In view of this, it is very imminence that Nuclear Power Company should promote the cost management levels and built the nuclear safety based lower cost competitive advantage. Activity based costing management (ABCM) transfer the cost management emphases from the 'product' to the 'activity' using the value chain analysis methods, cost driver analysis methods and so on. According to the analysis of the detail activities and the value chains, cancel the unnecessary activity, low down the resource consuming of the necessary activity, and manage the cost from the source, achieve the purpose of reducing cost, boosting efficiency and realizing the management value. It gets the conclusion from the detail analysis with the nuclear power company procedure and activity, and also with the selection to 'pieces analysis' of the important cost related project in the nuclear power company. The conclusion is that the activities of the nuclear power company has the obviously performance. It can use the management of ABC method. And with the management of the procedure and activity, it is helpful to realize the nuclear safety based low cost competitive advantage in the nuclear power company. (author)

  16. Activation analysis of the compact ignition tokamak

    Selcow, E.C.

    1986-01-01

    The US fusion program has completed the conceptual design of a compact tokamak device that achieves ignition. The high neutron wall loadings associated with this compact deuterium-tritium-burning device indicate that radiation-related issues may be significant considerations in the overall system design. Sufficient shielding will be requied for the radiation protection of both reactor components and occupational personnel. A close-in igloo shield has been designed around the periphery of the tokamak structure to permit personnel access into the test cell after shutdown and limit the total activation of the test cell components. This paper describes the conceptual design of the igloo shield system and discusses the major neutronic concerns related to the design of the Compact Ignition Tokamak.

  17. Activation analysis of the compact ignition tokamak

    The US fusion program has completed the conceptual design of a compact tokamak device that achieves ignition. The high neutron wall loadings associated with this compact deuterium-tritium-burning device indicate that radiation-related issues may be significant considerations in the overall system design. Sufficient shielding will be requied for the radiation protection of both reactor components and occupational personnel. A close-in igloo shield has been designed around the periphery of the tokamak structure to permit personnel access into the test cell after shutdown and limit the total activation of the test cell components. This paper describes the conceptual design of the igloo shield system and discusses the major neutronic concerns related to the design of the Compact Ignition Tokamak

  18. A statistical analysis of electrical cerebral activity

    The aim of this work was to study the statistical properties of the amplitude of the electroencephalographic signal. The experimental method is described (implantation of electrodes, acquisition and treatment of data). The program of the mathematical analysis is given (calculation of probability density functions, study of stationarity) and the validity of the tests discussed. The results concerned ten rabbits. Trips of EEG were sampled during 40 s. with very short intervals (500 μs). The probability density functions established for different brain structures (especially the dorsal hippocampus) and areas, were compared during sleep, arousal and visual stimulus. Using a Χ2 test, it was found that the Gaussian distribution assumption was rejected in 96.7 per cent of the cases. For a given physiological state, there was no mathematical reason to reject the assumption of stationarity (in 96 per cent of the cases). (author)

  19. Mathematical analysis of complex cellular activity

    Bertram, Richard; Teka, Wondimu; Vo, Theodore; Wechselberger, Martin; Kirk, Vivien; Sneyd, James

    2015-01-01

    This book contains two review articles on mathematical physiology that deal with closely related topics but were written and can be read independently. The first article reviews the basic theory of calcium oscillations (common to almost all cell types), including spatio-temporal behaviors such as waves. The second article uses, and expands on, much of this basic theory to show how the interaction of cytosolic calcium oscillators with membrane ion channels can result in highly complex patterns of electrical spiking. Through these examples one can see clearly how multiple oscillatory processes interact within a cell, and how mathematical methods can be used to understand such interactions better. The two reviews provide excellent examples of how mathematics and physiology can learn from each other, and work jointly towards a better understanding of complex cellular processes. Review 1: Richard Bertram, Joel Tabak, Wondimu Teka, Theodore Vo, Martin Wechselberger: Geometric Singular Perturbation Analysis of Burst...

  20. ANALYSIS OF OPERATIONAL AND INVESTMENT ACTIVITIES OF LOCAL ADMINISTRATION

    BATRANCEA, Ioan; STOIA Ioan; CSEGEDI Sandor

    2013-01-01

    In this paper the authors describe how the analysis of operational and investment activities in conjunction with the financial policies of firms subordinated to county councils in the North-West of Romania.

  1. Application of reactor activation analysis to hydrogeology and geology

    Instrumental reactor activation analysis applied to hydrogeological and geological investigations conducted at the Department of Radiometry of the Geological Techniques Research and Development Centre is discussed. Used instrumentation and analytical techniques are described. (author)

  2. The verification of neutron activation analysis support system (cooperative research)

    Neutron activation analysis support system is the system in which even the user who has not much experience in the neutron activation analysis can conveniently and accurately carry out the multi-element analysis of the sample. In this verification test, subjects such functions, usability, precision and accuracy of the analysis and etc. of the neutron activation analysis support system were confirmed. As a method of the verification test, it was carried out using irradiation device, measuring device, automatic sample changer and analyzer equipped in the JRR-3M PN-3 facility, and analysis software KAYZERO/SOLCOI based on the k0 method. With these equipments, calibration of the germanium detector, measurement of the parameter of the irradiation field and analysis of three kinds of environmental standard sample were carried out. The k0 method adopted in this system is primarily utilized in Europe recently, and it is the analysis method, which can conveniently and accurately carried out the multi-element analysis of the sample without requiring individual comparison standard sample. By this system, total 28 elements were determined quantitatively, and 16 elements with the value guaranteed as analytical data of the NIST (National Institute of Standards and Technology) environment standard sample were analyzed in the accuracy within 15%. This report describes content and verification result of neutron activation support system. (author)

  3. Diagnosis of mucoviscidosis by neutron activation analysis. Part 1

    Symptoms pathology, incidence, and gravity of the inherent syndrome called mucoviscidosis, or cystic fibrosis are described in this Part I. The analytical methods used for its diagnosis, both the conventional chemical ones and by neutron activation analysis are also summarised. Finally, an analytical method to study the incidence of mucoviscidosis in Brazil is presented. This , essentially, consists in bromine determination, in fingernails, by resonance neutron activation analysis. (author)

  4. Neutron activation analysis of cadmium in Jamaican soils

    A procedure for the instrumental neutron activation analysis of Cd in soils with relatively high Cd content and possible interferences is reported. Cadmium concentrations in Jamaican soils above 4 mg x kg-1 can now be reliably determined by multielemental instrumental activation analysis with an accuracy ±10% and the reasonably high throughput of 30 samples per day. Over 600 geochemical survey samples were analysed for Cd along with some 20 other long-lived elements. (author)

  5. Prompt Gamma-Ray Neutron Activation Analysis (PGNAA) for Elemental Analysis

    Robin P. Gardner

    2006-04-11

    This research project was to improve the prompt gamma-ray neutron activation analysis (PGNAA) measurement approach for bulk analysis, oil well logging, and small sample thermal enutron bean applications.

  6. Gaia Payload Module Testing and Analysis Activities

    Soula, Laurent

    2012-07-01

    The Gaia objective is to produce a very accurate catalogue of 1 billion of sky objects in our galaxy and beyond. ASTRIUM’s extensive experience on silicon carbide (SiC) instruments has helped developing the latest-generation payload module. It integrates the most sensitive and stable telescopes ever made, mounted on a SiC torus structure supported by three bipods. This payload module has been tested in June 2011 by ASTRIUM at INTESPACE facilities in Toulouse. To conduct the sine qualification tests and support the data analyses in real-time, advanced tools have been used. Most of them have been developed in a previous ESA R&D project [1] “DYNamics: AssessMent and Improvement of TEst Data (DYNAMITED)” and implemented in a DynaWorks® environment. Mass Operator calculation, to evaluate the payload module interface loads from measured accelerations, or automatic correlation through a criterion based on FRF from tests or predictions, are part of these tools. Testing such a structure also revealed some piloting difficulties due to a quite low and varying damping of the structure and a strong coupling with the shaker. To take into account such phenomena in the correlation work, enhanced simulations have also been performed considering multi-points phased excitations. These analyses demonstrate the payload module qualification status and allow derivate a more representative model to be used in further coupled system activities.

  7. ANALYSIS OF ECOLOGICAL ACTIVITY OF PODLASIE PROVINCE

    Agnieszka Kisło

    2014-01-01

    Full Text Available The beginning of the period where the impact of human activity took dangerous size is considered to be 40 years of the nineteenth century. Then the large-scale production of electricity increased production of metallurgical industry and transport development. Significant changes contributed to rapid population growth and urbanization and industrialization processes. Man by intensive exploitation reduces or completely exhausted most natural resources. This has resulted in the availability criterion, which is distinguished by inexhaustible and exhaustible resources. Exhaustible resources may include solar, wind, energy, ocean currents and the energy of the Earth. Exhaustible resources, however, are the elements of nature that as a result of the operation can be completely depleted or destroyed. These resources include: water, soil, plant world, animal world natural resources. The greater the intensity of acquiring human resources, the faster will be the depleted. There is also a very important division of exhaustible resources: non-renewable resources, renewable and very difficult reproducible (living areas. Non-renewable resources are mainly minerals, such as iron ore, crude oil, coal, sulfur, natural gas, useful stones, limestone, salt, and many other minerals. After extraction resources are processed, and the bed from which they were extracted can no longer be used. It is different from renewable resources; they are characterized by the fact that over time they are reconstituted, although, for this to happen balance of the environment through the rational use must be maintained. These resources include, among others, soil, water, flora and fauna, as well as atmospheric air.

  8. Spatiotemporal Data Mining, Analysis, and Visualization of Human Activity Data

    Li, Xun

    2012-01-01

    This dissertation addresses the research challenge of developing efficient new methods for discovering useful patterns and knowledge in large volumes of electronically collected spatiotemporal activity data. I propose to analyze three types of such spatiotemporal activity data in a methodological framework that integrates spatial analysis, data…

  9. Applying an Activity System to Online Collaborative Group Work Analysis

    Choi, Hyungshin; Kang, Myunghee

    2010-01-01

    This study determines whether an activity system provides a systematic framework to analyse collaborative group work. Using an activity system as a unit of analysis, the research examined learner behaviours, conflicting factors and facilitating factors while students engaged in collaborative work via asynchronous computer-mediated communication.…

  10. Performance analysis of active schedules in identical parallel machine

    Changjun WANG; Yugeng XI

    2007-01-01

    Active schedule is one of the most basic and popular concepts in production scheduling research. For identical parallel machine scheduling with jobs' dynamic arrivals, the tight performance bounds of active schedules under the measurement of four popular objectives are respectively given in this paper. Similar analysis method and conclusions can be generalized to static identical parallel machine and single machine scheduling problem.

  11. Project-Based Language Learning: An Activity Theory Analysis

    Gibbes, Marina; Carson, Lorna

    2014-01-01

    This paper reports on an investigation of project-based language learning (PBLL) in a university language programme. Learner reflections of project work were analysed through Activity Theory, where tool-mediated activity is understood as the central unit of analysis for human interaction. Data were categorised according to the components of human…

  12. Applied research of environmental monitoring using instrumental neutron activation analysis

    Chung, Young Sam; Moon, Jong Hwa; Chung, Young Ju

    1997-08-01

    This technical report is written as a guide book for applied research of environmental monitoring using Instrumental Neutron Activation Analysis. The contents are as followings; sampling and sample preparation as a airborne particulate matter, analytical methodologies, data evaluation and interpretation, basic statistical methods of data analysis applied in environmental pollution studies. (author). 23 refs., 7 tabs., 9 figs.

  13. Significance of neutron activation analysis in landscape geochemistry problem solution

    Employment of neutron activation analysis is of interest for solution of many theoretical and applied problems of landscape geochemistry. The role of the analysis in the study of rare and scattered element migration is quite significant. It is shown using gold, bromine, yttrium and rare earths as examples. 1 tab

  14. Neutron activation analysis of chert artifacts from a Hopewell mound

    Six artifacts from a Hopewell mound located near Mt. Vernon, Indiana, and 21 geologic specimens from three different chert sources in the Ohio River Valley were analyzed by instrumental neutron activation analysis. Principal components analysis and posterior classification of the artifacts on the basis of Mahalanobis distance calculated probabilities were used to determine the most probable source for each of the artifacts. (author)

  15. Supply and demand analysis of leisure activities in selected region

    Helcl, Petr

    2014-01-01

    The Thesis on the topic "Supply and demand analysis of leisure activities in the region," focuses on the forms of spending free time in the selected region. The theoretical part deals with the study of scientific publications focusing on leisure and leisure education. The economic concepts are examined to define the work, factors affecting leisure adults and content of leisure activities and leisure educational activities. The legal system of the Czech Republic defining the possibilities of a...

  16. Spatial heterogeneity analysis of brain activation in fMRI

    Lalit Gupta

    2014-01-01

    Full Text Available In many brain diseases it can be qualitatively observed that spatial patterns in blood oxygenation level dependent (BOLD activation maps appear more (diffusively distributed than in healthy controls. However, measures that can quantitatively characterize this spatial distributiveness in individual subjects are lacking. In this study, we propose a number of spatial heterogeneity measures to characterize brain activation maps. The proposed methods focus on different aspects of heterogeneity, including the shape (compactness, complexity in the distribution of activated regions (fractal dimension and co-occurrence matrix, and gappiness between activated regions (lacunarity. To this end, functional MRI derived activation maps of a language and a motor task were obtained in language impaired children with (Rolandic epilepsy and compared to age-matched healthy controls. Group analysis of the activation maps revealed no significant differences between patients and controls for both tasks. However, for the language task the activation maps in patients appeared more heterogeneous than in controls. Lacunarity was the best measure to discriminate activation patterns of patients from controls (sensitivity 74%, specificity 70% and illustrates the increased irregularity of gaps between activated regions in patients. The combination of heterogeneity measures and a support vector machine approach yielded further increase in sensitivity and specificity to 78% and 80%, respectively. This illustrates that activation distributions in impaired brains can be complex and more heterogeneous than in normal brains and cannot be captured fully by a single quantity. In conclusion, heterogeneity analysis has potential to robustly characterize the increased distributiveness of brain activation in individual patients.

  17. Neutron activation analysis for environmental sample in Thailand

    Busamongkol, Arporn; Nouchpramool, Sunun; Bunprapob, Supamatthree [Office of Atomic Energy for Peace, Bangkok (Thailand); Sumitra, Tatchai [Chulalongkorn Univ., Dept. of Nuclear Technology, Bangkok (Thailand)

    2003-03-01

    Neutron Activation Analysis has been applied for the trace elements analysis in environmental samples. Thirty three samples of airborne particulate were collected every week at Ongkharak Nuclear Research Center (ONRC) during the period of June 1998 to March 1999. The Ti, I, Mg, Na, V, K, Cl, Al, Mn, Ca, As, Sm, Sb, Br, La, Ce, Th, Cr, Cs, Sc, Rb, Fe, Zn and Co were analyzed by Neutron Activation Analysis utilizing 2 MW TRIGA MARK III research reactor. The certified reference materials 1632a and 1633a from National Bureau of Standard were select as standard. (author)

  18. Silicate rock and rock forming mineral neutron activation analysis

    A neutron-activation scheme for the determination of nine rare earths and other trace elements in various rock forming minerals (feldspars, ilmenite, magnetite, pyroxenes) and silicate rocks is presented. The procedure is based on three different irradiations involving three separate samples: - epithermal neutron irradiation (2 days) followed by nondestructive analysis; - thermal neutron irradiation (1 day) followed by instrumental analysis; - thermal neutron irradiation (1 week) followed by radiochemical analysis (precipitation, anion exchange separation, liquid-liquid extraction). Two USGS reference samples - granite G-2 and andesite AGV-1 - have been analysed in order to assess the accuracy of the proposed procedure. Our results agree with previous neutron-activation data. (orig.)

  19. Neutron activation analysis for environmental sample in Thailand

    Neutron Activation Analysis has been applied for the trace elements analysis in environmental samples. Thirty three samples of airborne particulate were collected every week at Ongkharak Nuclear Research Center (ONRC) during the period of June 1998 to March 1999. The Ti, I, Mg, Na, V, K, Cl, Al, Mn, Ca, As, Sm, Sb, Br, La, Ce, Th, Cr, Cs, Sc, Rb, Fe, Zn and Co were analyzed by Neutron Activation Analysis utilizing 2 MW TRIGA MARK III research reactor. The certified reference materials 1632a and 1633a from National Bureau of Standard were select as standard. (author)

  20. Neutron activation analysis of multielement in human organs

    To obtain the reference values or ranges of the elemental abundances in organs of Japanese male, neutron activation analysis was applied to nine kinds of autopsied organs, brain, heart, kidney, liver, lung, muscle, pancreas, spleen and thyroid. An applicability of multielement analysis of organs was studied prior to ordinary work. Accuracy and precision were investigated by analyzing the IAEA Certified Reference Materials, Horse Kidney, Whey Powder and Marine Sediment. The changes of count rate on various weights and the variations of the elemental abundances of five portions in organ were examined. It was found that organs were homogeneous for neutron activation analysis, except for kidney and lung. (author)

  1. Activation analysis in the environment: Science and technology

    Science is disciplined curiosity. Activation analysis was created more than 50 yr ago by Hevesy's curiosity and Levi's experimental skill. Technology is the exploitation of machines and materials for the fulfillment of human needs or wants. The early history of neutron activation analysis (NAA) was greatly influenced by military requirements. Since then the technique has found applications in many disciplines, including materials science, medicine, archaeology, geochemistry, agriculture, and forensic science. More recently, neutron activation analysts, responding to increasing public interest and concern, have made distinctive contributions to the study of environmental problems. Activation analysis, though it uses some procedures derived from physics, is essentially a chemical technique. The chemical study of the environment may be reviewed under many headings; three are discussed here: 1. occupational medicine 2. health of the general public 3. environmental pollution

  2. Methodology for determination of activity of radionuclides by gamma spectrometry; Metodologia para determinacao da atividade de radionuclideos por sistema de espectrometria gama

    Fragoso, Maria da Conceicao de Farias; Oliveira, Victor Rogerio S. de; Oliveira, Mercia L.; Lima, Fernando Roberto de Andrade, E-mail: mariacc05@gmail.com [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-NE), Recife, PE (Brazil)

    2014-07-01

    Due to the growth in the number of procedures that make use of the positron emission tomography (PET), there is a need for standard solutions for the calibration of the systems used for the measurement of the PET radiopharmaceutical (activimeter) in radiopharmacies and in nuclear medicine services. Among the existing alternatives for the standardization of radioactive sources, the method known as gamma spectrometry is widely used for short-lived radionuclides. The purpose of this study was to implement the methodology for standardization of the {sup 18}F solutions by gamma spectrometry at the Regional Center for Nuclear Sciences of the Northeast (CRCN-NE/CNEN-NE), Brazil. (author)

  3. Determination of the crust thickness in the active margin of the Antarctic region; Determinacao da estrutura crustal na margem ativa da regiao antartica

    Torres, Luiz Carlos; Gamboa, Luiz Antonio Pierantoni [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Lagemar; Gomes, Benedito Souza [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    1997-07-01

    Seismic multichannel, gravity and magnetometry measurements were carried out in the region of West coast of the Antarctic Peninsula, Bransfield Strait, South Shetland Islands and South Shetland Trench, by Brazilian Antarctic Program during the summers of 1987 and 1988. The present work, using a continue seismic and gravity and gravity data profile crossing the area, intends to present a two-dimensional model of the crust thickness in this region. By this model, the Moho discontinuity would lie at a depth of 14.5 km below the axis of the Bransfield trough. This anomalous behaviour in addition to compressional processes identified in the accretionary prism and trench, was interpreted as an evidence of the continued opening of the Bransfield basin. (author)

  4. Cytotoxic activity and phytochemical analysis of Arum palaestinum Boiss.

    Mai; Mohammed; Farid; Sameh; Reda; Hussein; Lamiaa; Fawzy; Ibrahim; Mohammed; Ali; El; Desouky; Amr; Mohammed; Elsayed; Ahmad; Ali; El; Oqlah; Mahmoud; Mohammed; Saker

    2015-01-01

    Objective: To evaluate the in vitro cytotoxic activity of the fractionated extract as well as isolated compounds of Arum palaestinum Boiss.(A. palaestinum)(black calla lily), and to identify the volatile components which may be responsible for the potential antitumor activity.Methods: A. palaestinum was collected from its natural habitats and subjected to phytochemical analysis for separation of pure compounds. In vitro cytotoxic activity was investigated against four human carcinoma cell lines Hep2, He La, Hep G2 and MCF7 for the fractionated extract and isolated compounds. While, the diethyl ether fraction was subjected to GC–MS analysis as it exhibited the most potent cytotoxic effect to evaluate the active constituents responsible for the cytotoxic activities.Results: Four flavonoid compounds were isolated(luteolin, chrysoeriol, isoorientin,isovitexin) from the diethyl ether and ethyl acetate. The extracts and the pure isolated compounds showed a significant high antiproliferative activity against all investigated cell lines. The GC–MS analysis revealed the separation and identification of 15 compounds representing 95.01% of the extract and belonging to different groups of chemical compounds.Conclusions: The present study is considered to be the first report on the cytotoxic activities carried out on different selected fractions and pure compounds of A. palaestinum to provide evidences for its strong antitumor activities. In addition,chrysoeriol and isovitexin compounds were isolated for the first time from the studied taxa.

  5. Cytotoxic activity and phytochemical analysis of Arum palaestinum Boiss

    Mai Mohammed Farid; Sameh Reda Hussein; Lamiaa Fawzy Ibrahim; Mohammed Ali El Desouky; Amr Mohammed Elsayed; Ahmad Ali El Oqlah; Mahmoud Mohammed Saker

    2015-01-01

    Objective:To evaluate the in vitro cytotoxic activity of the fractionated extract as well as isolated compounds of Arum palaestinum Boiss. (A. palaestinum) (black calla lily), and to identify the volatile components which may be responsible for the potential antitumor activity. Methods: A. palaestinum was collected from its natural habitats and subjected to phytochemical analysis for separation of pure compounds. In vitro cytotoxic activity was investigated against four human carcinoma cell lines Hep2, HeLa, HepG2 and MCF7 for the fractionated extract and isolated compounds. While, the diethyl ether fraction was subjected to GC–MS analysis as it exhibited the most potent cytotoxic effect to evaluate the active constituents responsible for the cytotoxic activities. Results:Four flavonoid compounds were isolated (luteolin, chrysoeriol, isoorientin, isovitexin) from the diethyl ether and ethyl acetate. The extracts and the pure isolated compounds showed a significant high antiproliferative activity against all investigated cell lines. The GC–MS analysis revealed the separation and identification of 15 compounds representing 95.01%of the extract and belonging to different groups of chemical compounds. Conclusions:The present study is considered to be the first report on the cytotoxic activities carried out on different selected fractions and pure compounds of A. palaestinum to provide evidences for its strong antitumor activities. In addition, chrysoeriol and isovitexin compounds were isolated for the first time from the studied taxa.

  6. Determination of essential trace elements in diets from pre-school children; Determinacao de elementos traco essenciais em dietas de criancas de idade pre-escolar

    Maihara, Vera Akiko; San Miguel, Americo T.; Vasconcellos, Marina Beatriz A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    1995-12-31

    The contents of Br, Ca, Cl, Co, Cr, Cs, Fe, K, Mn, Na, Rb, Se and Zn in the 19 diet samples taken from pre-school children were determined by neutron activation analysis. The diet samples were collected by duplicate portion method. The daily intake values obtained were compared with the RDA (Recommended Dietary Allowance) values. The precision and accuracy were evaluated by analyzing two biological reference materials. (author). 7 refs., 4 tabs.

  7. A new microcomputer-controlled neutron activation and analysis system

    A microcomputer-controlled irradiation and measurement system and a microprocessor-controlled sample changer have been installed at the SLOWPOKE-2 Facility at the Royal Military College of Canada (RMC). These systems can provide the gamut of instrumental neutron activation analysis (INAA) techniques for the analyst. Custom software has been created for system control, data acquisition, and off-line spectral analysis using programs that incorporate Gaussian peak-fitting methods of analysis. The design and use of the equipment is discussed, and the performance is illustrated with results obtained from the analysis of marine sediment and biological reference materials

  8. Simulation for sodium-24 production using cyclic neutron activation analysis

    The cyclic neutron activation analysis is a method for elemental analysis which is preferred to use short-lived radio-nuclides. In recent years this method became a new application for radioisotope production especially in low power research reactors. In this study instrumental cyclic neutron activation analysis was used for 24Na production using 23Na (n, γ) 24Na reaction. The simplified westcott convention method is used neutron activation analysis in a research reactor. The method takes into account all corrections that can affect that yield created. In this work a model was devolving for calculations through this simplified Westcott convention method by using C++ program and selecting good parameters that can produce the expected activity. The simulation is used for the theoretical yield calculated has been validated by data from the 177Lu production used for theoretical yield which it gives the approached result had been obtained by FORTRAN 90 from literature (8). The results were achieved for expected activity at full power (1 x 10 12n cm-2 s-1) and half power (5 x 1011 cm-2 s-1) for research reactor MNSR. The activity at full power was equal to about twice the activity at half power ( 49±7, 24.9 ± MBq/g), respectively. The irradiation parameters selected were irradiation time 4 min and decay time 12 min. Sample weight was 50 mg at 12 numbers of cycles, when the K-factor was equal to 1.74. This work is considered as first step for production of 24Na which can use such parameters experimentally. It is then possible to compare the expected activity with measured activity. (Author)

  9. A package for gamma-ray spectrum analysis and routine neutron activation analysis

    M E Medhat; A Abdel-Hafiez; Z Awaad; M A Ali

    2005-08-01

    A package for gamma spectrum analysis (PGSA) was developed using object oriented Borland C++ design for MS-windows. This package consists of five programs which can be used for gamma-ray spectrum analysis and routine neutron activation analysis. The advantages of PGSA are its simple algorithms and its need for only minimum amount of input information.

  10. MODEL OF ACTIVITY OF THE ENTERPRISE AS MODEL OF ACTIVITY OF THE HUMAN: SEARCH ANALYSIS

    Ruslan Flerovich Vildanov; Aidar Sultangalievich Puryaev

    2014-01-01

    Actualized demand of manufactury company's efficiency from the point of quality charachteristics. Reveal unbreakable connection of man and organisation, on example of the comparative analysis of man's and manufacture company's activities. Studing models of company's and men's activities in order to reveal similarity. In order of their implementation to the economics assumes opportunity of using scientific methods, which use for studying functions, vital activities and behavior of the men.

  11. Analysis of nuclear activity of ten polar ring galaxies

    Freitas-Lemes, P; Dors, O L; Faúndez-Abans, M

    2013-01-01

    The accumulation of mass from the interaction process that forms the polar ring galaxies is a factor that favors the conditions necessary to trigger nonthermal nuclear activities.. This fact encouraged the chemical analysis of ten polar ring galaxies. In order to verify the presence of an active nucleus in these galaxias, we built diagnostic diagrams using lines H{\\beta}, [OIII], [HI], H{\\alpha}, [NII], and [SII] and classified the type of nuclear activity. For galaxies that do not show shock, the parameters N2 and O3N2 were also determined. From this sample, we identified seven galaxies with an active nucleus and three that behave as HII regions. One galaxy with an active nucleus was classified as Seyfert. Although our data do not provide a statistically significant sample, we can speculate that polar ring galaxies are a setting conducive to trigger non-thermal nuclear activities.

  12. Activation analysis in the Americas: recent and future perspectives

    A total of 243 publications in the field of nuclear activation analysis and its applications during the period of 1977 through mid-1983, from laboratories in North, Central, and South America were reviewed. Various aspects of these populations are treated statistically, for indication of trends, and 146 of these are cited as publications that illustrate the extent of usage of various special forms of the nuclear activation analysis method (e.g., cyclic INAA, prompt-gamma INAA, epithermal NAA, the delayed-neutron method, the use of pre-irradiation chemical separations, etc.) - or that illustrate applications in such fields as archaeology, geochemistry, environmental chemistry, medicine, industry, and forensic chemistry. The overall conclusion is that the method of nuclear activation analysis continues to flourish in this region

  13. INDUSTRIAL/MILITARY ACTIVITY-INITIATED ACCIDENT SCREENING ANALYSIS

    D.A. Kalinich

    1999-09-27

    Impacts due to nearby installations and operations were determined in the Preliminary MGDS Hazards Analysis (CRWMS M&O 1996) to be potentially applicable to the proposed repository at Yucca Mountain. This determination was conservatively based on limited knowledge of the potential activities ongoing on or off the Nevada Test Site (NTS). It is intended that the Industrial/Military Activity-Initiated Accident Screening Analysis provided herein will meet the requirements of the ''Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants'' (NRC 1987) in establishing whether this external event can be screened from further consideration or must be included as a design basis event (DBE) in the development of accident scenarios for the Monitored Geologic Repository (MGR). This analysis only considers issues related to preclosure radiological safety. Issues important to waste isolation as related to impact from nearby installations will be covered in the MGR performance assessment.

  14. Development of activation analysis on the IBR-2 reactor

    Different examples of activation analysis (AA) application and probabilities of its further development using IBR-2 reactor (Dubna) with two facilities: REGATA pneumotransport facility desigued for instrumental AA and biophysical channel designed for element analysis using capture prompt quanta and radiography-are considered. Characteristics of irradiation channels, values of flux densities for thermal, resonance and fast neutrons are given. Application advantages concerning instrumental AA of resonance neutrons are considered. New application trend of AA for composition optimization of concretes used in shielding structures of nuclear reactors, for reduction of long-lived directed activity is pointed out. 20 refs.; 6 figs.; 7 tabs

  15. Neutron Activation Analysis for investigation of elemental composition of Amarantus

    In this work instrumental neutron activation analysis is applied for the characterization of the elemental composition of Amaranthus seeds, known in the prehistorical period, a tropical plant with promising nutritional and economic value. The characterization is enriched by the results of radiochemical neutron activation analysis for cobalt, molybdenum and uranium content. The comparison of the results, for three sorts of edible flour, commercially available: Soya Flour, Corn Bean Flour and Amaranthus Flour, is presented. The validation of the analytical methods used was carried out on the basis of participation in the interlaboratory comparison organized by the INCT (INCT-TL-1, INCT-MPH-2) and by NIST (SRM 1575a). (author)

  16. Establishment of rabbit radiation facility for neutron activation analysis

    The transfer principle and the composition of a rabbit radiation facility for neutron activation analysis in a reactor were introduced. The functions and security designs of the pneumatic transfer system and automatic control system in the irradiation device were studied. By the testing,the transfer speed of the facility is 7.0 m/s. The facility has advantages of steady transmission, simple operation, easy maintenance, etc. The facility satisfies the demand of the neutron activation analysis for short half-life nuclides. (authors)

  17. Status Report on the Neutron Activation Analysis Activities in the Philippines

    The Philippines has a one megawatt open-pool type nuclear research reactor which is presently utilized in the conduct of nuclear research and development activities. The reactor is operated by the Philippine Atomic Research Center, the research arm of the Philippine Atomic Energy Commission. The reactor is presently utilized in the production of some radioisotopes, nuclear physics experiments and neutron activation analysis. For activation analysis the facilities available include the two 2 inch pneumatic tubes and a 2-inch central core dry-pipe. Although the reactor has been operative since 1963 it was only in the latter part of 1966 that a neutron activation analysis group was organized and almost immediately the training of personnel and setting up of a radiochemical laboratory and nucleonic counting assembly were initiated. Today, the counting system include a 100 channel analyzer with a 3 x 3 inch Nal(Tl) crystal

  18. Survey on Neutron Activation Analysis Activities at the Dalat Nuclear Research Centre

    The Dalat Nuclear Research Centre (D.N.R.C.) during the past few years has been involved in conducting an activation analysis service. Work has been carried out in collaboration with other organizations. However, no rigid research programme of our own has been established and thus the Radiochemistry Division of the D.N.R.C. has no personnel and special facilities permanently engaged in this field. The equipment and facilities used are shared with other activities within the Division and the whole Centre. The activities in neutron activation analysis at the D.N.R.C. are sporadically revived by requests for analysis. Up to now, such analyses have been performed free of charge. Most of the work was carried out on biological materials such as vegetables, raw natural rubber (RES smoked sheets of different qualities, crepes and dried rubber films obtained from concentrated natural latex) from hevea tree leaves from various clones

  19. Xenon diffusion studies with prompt gamma activation analysis

    Developing a better understanding of xenon transport through porous systems is critical to predicting how this gas will enter the atmosphere after a below ground nuclear weapons test. Radioxenon monitoring is a vital part of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) International Monitoring System. This work details the development of prompt gamma activation analysis for measuring the diffusion rates of xenon and argon gases through a porous medium. The University of Texas at Austin maintains a prompt gamma activation analysis facility with a peak neutron flux of ∼ 1.5 x 107 cm-2 s-1 and a beam diameter of 1 cm. Due to the relatively large prompt gamma cross sections of many stable xenon isotopes at thermal and sub-thermal neutron energies, prompt gamma activation analysis is a suitable technique for in situ non-destructive analysis of natural xenon. A test chamber has been designed and constructed to utilize prompt gamma activation analysis to measure xenon and argon diffusion through geological materials (e.g., sand, soil, etc.). Initial experiments have been conducted to determine the detection limits for stable gas measurements. The results from these experiments will be utilized to benchmark parts of a xenon transport model that is being used to determine diffusion coefficients for xenon and argon. (author)

  20. Prompt gamma neutron activation analysis as an active interrogation technique for nuclear materials

    Prompt gamma neutron activation analysis (PGAA) is proposed as an instant, non-destructive method for the analysis of fissile materials and fission products. Measurements by PGAA were made on technetium and uranium compounds, the latter with various enrichments. Measurements were carried out in thermal and cold neutron beams at the Budapest Research Reactor. A beam chopper was used to collect the delayed decay gamma radiation from short lived nuclides separately. Accurate partial gamma ray production cross-sections were determined with internal standardization for a set of prompt and decay gamma rays following neutron capture in 235U, 238U and 99Tc and compared to those from the literature. In the case of 235U fission, prompt gamma lines were also applied.These cross-sections can be used for non-destructive analyses of uranium and technetium and also for the determination of the enrichment of uranium by prompt gamma activation analysis and neutron activation analysis. (author)

  1. DNQAA program to be used in activation analysis

    The concentrations of the analysed elements were calculated by the program, based on the instrumental technique of analysis by activation. The DNQAA corrects due to the radioactive decay and to the neutron flow variation or carried particles and too the error propagation involved in the analysis. It is written in ORACL to be used in the ORTEC 6240-42 system. (L.M.J.)

  2. Protein determination in soya bean by fast neutron activation analysis

    For a non-destructive determination of the protein content in soya bean samples, 14-MeV neutron activation analysis was applied. To check the method, the results obtained by X-ray fluorescence analysis and the Kjeldahl procedure were compared. For pressed pellet samples of about 1 g with 15 min irradiation and 10 min measuring times the accuracy of the protein determination was found to be 15%. (author) 7 refs.; 4 figs.; 3 tabs

  3. Behaviour analysis for web-mediated active learning

    Pahl, Claus

    2007-01-01

    Software-mediated learning requires adjustments in the teaching and learning process. In particular active learning facilitated through interactive learning software differs from traditional instructor-oriented, classroom-based teaching. We present behaviour analysis techniques for Web-mediated learning. Motivation, acceptance of the learning approach and technology, learning organisation and actual tool usage are aspects of behaviour that require different analysis techniques to be used. ...

  4. Instrumental Neuron Activation Analysis for certification of stainless steel materials

    The use of Instrumental Neuron Activation Analysis (INAA) may contribute to improve the certification of the materials, especially in the case of minor and trace elements. In presented paper the INAA method of analysis of stainless steel materials has been elaborated. The obtained results were compared with those of common analytical techniques. The presented results show the usefulness of the INAA method for the certification of CRMs for the iron and steel industry

  5. Nondestructive multielemental analysis of ancient roman pottery using photon activation analysis techniques

    Several analytical methods were tested for the multiparameter-analysis of ancient roman pottery in order to elaborate a procedure for their identification. Main constituents, minor and trace-elements have been analyzed by high-energy photon activation analysis, followed by high resolution gamma spectroscopy. The environmental influence on the concentrations of the minor constituents and trace elements during deposition of the sherds in the soil has been examined. A comparison has been made between analysis data of ancient pottery obtained by photon activation analysis, X-ray fluorescence analysis and 14 MeV neutron activation analysis. Tables are given on the time dependence of the trace elements. The numerical data are summarized in several diagrams. (T.G.)

  6. History of activation analysis technique with charged particles in Uzbekistan

    Full text: The researches on activation analysis with charged particles (CPAA) were started immediately after beginning of constructing of 150-cm cyclotron U-150 in 60-th years of last century. CPAA laboratory organized on bases of the cyclotron and neutron generator NG-200 (in following I-150) in 1971 existed up to the end of 1985. We have used Ion beams of these devices to elaborate two types of nuclear analysis techniques: 1. Delayed Nuclear Analysis (DNA) involving Charged Particle Activation Analysis (CPAA) and Fast Neutron Activation Analysis (FNAA); 2. Prompt Nuclear Analysis (PNA) involving the spectrometry of particles induced X-Ray emission (PIXE). DNA with using accelerators has the following subdivisions: 1. Proton Activation Analysis (PAA); 2. Deuteron Activation Analysis (DAA); 3. 3He Activation Analysis (3HeAA); 4. 4He Activation Analysis (4HeAA or α-AA); 5. Fast Neutron Activation Analysis (FNAA). PAA and DAA found wide application were used to derive a good sensitivity in determination of contents of more than 20 chemical elements in some materials of high purity. For example, we have applied these techniques for the determination of Li, B, C, N, O, F at level of 10-8 - 10-10 g/g in different high purity semiconductors (Si, SiC, Ge, AsGa, InP et al.), nonferrous metals (Li, Be, Zr, Nb, Mo, Ta, W, Re, Al, Ti etc.), nonconductive materials (different glasses, optical materials, diamonds et al.) and environmental objects (soil, plants, water). The techniques provided good results on the determination of B, C and N contents and others. 3HeAA and 4HeAA were generally used to determine of O and C contents in semiconductors ands metals of high purity. We have elaborated rapid radiochemical techniques for separation of short-lived positron emitters. For example, the separation of 15O, formatting by nuclear reaction 16O(3He,α)15O, the reducing fusion technique was used. Radionuclide 11C was separated chemically by the oxidisation of samples in the

  7. Structural Analysis Extended with Active Fault Isolation - Methods and Algorithms

    Gelso, Esteban R.; Blanke, Mogens

    2009-01-01

    Isolability of faults is a key issue in fault diagnosis whether the aim is maintenance or active fault-tolerant control. It is often encountered that while faults are detectable, they are only group-wise isolable from a usual diagnostic point of view. However, active injection of test signals on...... system inputs can considerably enhance fault isolability. This paper investigates this possibility of active fault isolation from a structural point of view. While such extension of the structural analysis approach was suggested earlier, algorithms and case studies were needed to explore this theory. The...

  8. Cluster analysis of activity-time series in motor learning

    Balslev, Daniela; Nielsen, Finn Å; Futiger, Sally A; Sidtis, John J; Christiansen, Torben B; Svarer, Claus; Strother, Stephen C.; Rottenberg, David A; Hansen, Lars K; Paulson, Olaf B.; Law, I

    2002-01-01

    Neuroimaging studies of learning focus on brain areas where the activity changes as a function of time. To circumvent the difficult problem of model selection, we used a data-driven analytic tool, cluster analysis, which extracts representative temporal and spatial patterns from the voxel...... practice-related activity in a fronto-parieto-cerebellar network, in agreement with previous studies of motor learning. These voxels were separated from a group of voxels showing an unspecific time-effect and another group of voxels, whose activation was an artifact from smoothing...

  9. Cluster analysis of activity-time series in motor learning

    Balslev, Daniela; Nielsen, Finn Årup; Frutiger, Sally A.; Sidtis, John J.; Christiansen, Torben; Svarer, Claus; Strother, Stephen C.; Rottenberg, David A.; Hansen, Lars Kai; Paulson, Olaf B.; Law, Ian

    2002-01-01

    Neuroimaging studies of learning focus on brain areas where the activity changes as a function of time. To circumvent the difficult problem of model selection, we used a data-driven analytic tool, cluster analysis, which extracts representative temporal and spatial patterns from the voxel...... practice-related activity in a fronto-parieto-cerebellar network, in agreement with previous studies of motor learning. These voxels were separated from a group of voxels showing an unspecific time-effect and another group of voxels, whose activation was an artifact from smoothing. Hum. Brain Mapping 15...

  10. IN VITRO ANALYSIS OF MIGRATION ACTIVITY OF ENCEPHALYTOGENIC T CEL

    M. A. Nosov

    2010-01-01

    Full Text Available Experimental autoimmune encephalomyelitis in an adoptive transfer model is caused by injecting animal with activated T cells specific for a CNS antigen, e.g., basic myelin protein. Development of autimmune inflammation in such a model is connected with changed functional stateof encephalytogenic (EG T cells in the coure of disease progression, as reflected by changes in their activation, proliferation and motility levels. Present work describes an original technique allowing for in vitro analysis of encephalytogenic T cell motility, and studying effects of certain compomemts of extracellular matrix upon migration and functional activities of EG T cells.

  11. Aerosol and air pollution study by neutron activation analysis

    Thermal neutron activation analysis technique was used in air pollution and aerosol elemental content and size distribution investigations. Air pollution samples were collected on Whatman 41 paper filters which were activated along with known quantities of standards in a flux of approximately 1013 nxcm-2xs-1. The activity of the samples was measured with a 40 cm3 Ge(Li) detector and analyzed with the computer program JANE, which identified the isotopes and found their quantities by normalization with the standard measurement results. Correlation between the various elements, in particular those belonging to dust from the desert and those considered typical urban air pollution, is investigated. (author)

  12. Neutron activation analysis of ivory of African elephants

    Instrumental neutron activation analysis was applied to 61 ivory samples of which origin countries are known. 12 elements such as Br, Ca, Cl, Co, Cs, Fe, Mg, Mn, Na, Sc, Sr and Zn, were determined in all samples. The factor score of each sample was calculated for each factor by making use of principal component analysis in order to determine their origins. The results were compared with those by stable isotope analysis (13C and 15N). (author). 4 refs., 5 figs. 4 tabs

  13. Analysis by Neutron activation of the Calakmul jadeite mask

    It is very important to know the elemental composition of archaeological materials with the purpose to find relations that allow to establish their origin standards. the origin and present localization of pre hispanic archaeological pieces can lead to the determination of commercial routes and of technology transfer among different ancient cultures. In the present work it has been realized a systematic analysis using the Instrumental neutron activation analysis technique of three samples obtained from Calakmul jadeite mask, tomb I, that in addition to give a composition of constituent and trace elements detected by this technique it has leaded to establish an applicable methodology to the routine analysis of ceramics of historical interest. (Author)

  14. Statistical analysis of acoustic wave parameters near active regions

    Soares, M Cristina Rabello; Scherrer, Philip H

    2016-01-01

    In order to quantify the influence of magnetic fields on acoustic mode parameters and flows in and around active regions, we analyse the differences in the parameters in magnetically quiet regions nearby an active region (which we call `nearby regions'), compared with those of quiet regions at the same disc locations for which there are no neighboring active regions. We also compare the mode parameters in active regions with those in comparably located quiet regions. Our analysis is based on ring diagram analysis of all active regions observed by HMI during almost five years. We find that the frequency at which the mode amplitude changes from attenuation to amplification in the quiet nearby regions is around 4.2 mHz, in contrast to the active regions, for which it is about 5.1 mHz. This amplitude enhancement (the `acoustic halo effect') is as large as that observed in the active regions, and has a very weak dependence on the wave propagation direction. The mode energy difference in nearby regions also changes...

  15. Study of the determination of copper by substoichiometric isotopic dilution analysis; Estudo da determinacao de cobre por analise por diluicao isotopica subestequiometrica

    Souza Faquim, Elaine de

    1994-12-31

    The tracer {sup 64} Cu having a half-life of 12,8 h produced by the irradiation of {sup 63} Cu with thermal neutron was separated by substoichiometric extraction of Cu(II) with dithizone in carbon tetrachloride. An aliquot of the organic layer was measured on a {gamma}-ray spectrometer consisting of a Na I(Tl) well-type detector and associated electronics. The influence of hydrochloric, sulfuric and nitric acids and the equilibrium time were studied. The reproducibility of the substoichiometric extraction was checked using increasing amounts of tracer {sup 64} Cu. The precision and accuracy of the method were tested using reference materials. After establishing the best analytical conditions, the method was applied to the determination of copper at trace levels in solid samples of diet, wheat flour and in liquid samples, like wine and beer. (author). 57 refs., 3 figs., 7 tabs.

  16. Statistical Analysis of Acoustic Wave Parameters Near Solar Active Regions

    Rabello-Soares, M. Cristina; Bogart, Richard S.; Scherrer, Philip H.

    2016-08-01

    In order to quantify the influence of magnetic fields on acoustic mode parameters and flows in and around active regions, we analyze the differences in the parameters in magnetically quiet regions nearby an active region (which we call “nearby regions”), compared with those of quiet regions at the same disk locations for which there are no neighboring active regions. We also compare the mode parameters in active regions with those in comparably located quiet regions. Our analysis is based on ring-diagram analysis of all active regions observed by the Helioseismic and Magnetic Imager (HMI) during almost five years. We find that the frequency at which the mode amplitude changes from attenuation to amplification in the quiet nearby regions is around 4.2 mHz, in contrast to the active regions, for which it is about 5.1 mHz. This amplitude enhacement (the “acoustic halo effect”) is as large as that observed in the active regions, and has a very weak dependence on the wave propagation direction. The mode energy difference in nearby regions also changes from a deficit to an excess at around 4.2 mHz, but averages to zero over all modes. The frequency difference in nearby regions increases with increasing frequency until a point at which the frequency shifts turn over sharply, as in active regions. However, this turnover occurs around 4.9 mHz, which is significantly below the acoustic cutoff frequency. Inverting the horizontal flow parameters in the direction of the neigboring active regions, we find flows that are consistent with a model of the thermal energy flow being blocked directly below the active region.

  17. The Analysis and Reconciliation of Students' Rebuttals in Argumentation Activities

    Lin, Yu-Ren; Hung, Jeng-Fung

    2016-01-01

    The present study investigated the guidance provided by science teachers to resolve conflicts during socioscientific issue-based argumentation activities. A graphical representation (GR) was developed as a tool to code and analyze the dialogue interaction process. Through the GR and qualitative analysis, we identified three types of dialogue…

  18. Neutron activation analysis of final molasses from the sugar industry

    Molasses samples from 74 factories were analyzed by neutron activation analysis. The concentration values of the 35 elements was determined. The toxicity and the influence of the presence of theses elements in sugar loss in the molasses and fermentative process is discussed

  19. Neutron activation analysis of different types of cuban sugar

    The Concentration of minor and trace elements in sugars (refined, crude and white-direct) from different Cuban mills were determined using instrumental neutron activation analysis with reactor, fourteen elements were fixed: Br, Ce, Co, Cr, Cs, Eu, Fe, La, Rb, Sc, Tb, Sr and Zn. The comparison of teh average concentration in sugar with another food samples is present

  20. Isotope identification of Langkawi black sand using neutron activation analysis

    The Langkawi black sand has been analyzed using the method of neutron activation analysis (INAA). A total of 22 elements have been detected. Elements such as Mn, Cu, Cr, U and Th occur in high concentration. Prospect for future mineralization of these elements may be of economic interest. (author) 9 refs.; 1 tab

  1. Instrumental Neutron Activation Analysis Technique using Subsecond Radionuclides

    Nielsen, H.K.; Schmidt, J.O.

    1987-01-01

    The fast irradiation facility Mach-1 installed at the Danish DR 3 reactor has been used in boron determinations by means of Instrumental Neutron Activation Analysis using12B with 20-ms half-life. The performance characteristics of the system are presented and boron determinations of NBS standard...

  2. Methodological developments and applications of neutron activation analysis

    Kučera, Jan

    2007-01-01

    Roč. 273, č. 2 (2007), s. 273-280. ISSN 0236-5731 Institutional research plan: CEZ:AV0Z10480505 Keywords : neutron activation analysis * radiochemical separation Subject RIV: BE - Theoretical Physics Impact factor: 0.499, year: 2007

  3. Mercury mass measurement in fluorescent lamps via neutron activation analysis

    Viererbl, L.; Vinš, M.; Lahodová, Z.; Fuksa, A.; Kučera, Jan; Koleska, M.; Voljanskij, A.

    2015-01-01

    Roč. 116, NOV (2015), s. 56-59. ISSN 0969-806X R&D Projects: GA TA ČR TA01010237; GA MŠk LM2011019 Institutional support: RVO:61389005 Keywords : fluorescent lamp * mercury measurement * neutron activation analysis * research reactor Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.380, year: 2014

  4. Application of prompt gamma-ray activation analysis

    Chung, Yong Sam; Park, Kwang Won; Moon, Jong Hwa; Kim, Sun Ha; Baek, Sung Ryel [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2002-03-01

    This technical report is written for the promotion to utilization of prompt gamma-ray activation analysis facility to be installed in HANARO reactor. It is described for a practical aspects including experiment and equipments, methodology, current status of the research and development and its applications. 102 refs., 32 figs., 25 tabs. (Author)

  5. Neutron activation analysis - an aid to forensic science

    Forensic Science is oriented towards the examination of evidence specimens, collected from a scene of crime in order to establish the link between the criminal and the crime. This science therefore has a profound role to play in criminal justice delivery system. The importance of neutron activation analysis (NAA) as a specialised technique to aid crime investigation has emerged and has been recognised

  6. Trace elements in higher fungi (mushrooms) determined by activation analysis

    Řanda, Zdeněk; Kučera, Jan

    2004-01-01

    Roč. 259, č. 1 (2004), s. 99-107. ISSN 0236-5731 R&D Projects: GA ČR GV202/97/K038 Institutional research plan: CEZ:AV0Z1048901 Keywords : trace elements * activation analysis * mushrooms Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 0.457, year: 2004

  7. Use of cyclotron-produced fast neutrons in activation analysis

    The determination of 15 elements: Pb, Sr, Ba, Ti, Ca, Sc, Cs, Zr, Rb, Cr, Se, Ni, Y, Co and Zn was investigated by fast neutron activation analysis using 80 MeV deuterons on various environmental samples. Detection limits of these elements from interference-free spectra were calculated. (author)

  8. Making Sense of Total VET Activity: An Initial Market Analysis

    National Centre for Vocational Education Research (NCVER), 2016

    2016-01-01

    Following the successful first national publication of total vocational education and training (VET) activity and presentation of various informative data products, NCVER has continued to undertake further analysis of the submitted data. This paper is the first in a suite of the National Centre for Vocational Education Research (NCVER) authored…

  9. Initial trials for in-house neutron activation analysis

    A range of elements in previously analysed rock samples have been assayed by neutron activation analysis and the practicality of performing such analyses at the Institute of Geological and Nuclear Sciences has been established. Further work is needed to fully refine the technique. A cost estimate has been made for a routine procedure. (author) 1 tab., 6 figs

  10. Limits of detection in instrumental neutron activation analysis

    Lower limits of detection (LLODs), frequently referred to simply as limits of detection and abbreviated as LODs, often appear in the literature of analytical chemistry - for numerous different methods of elemental and/or molecular analysis. In this chapter, one particular method of quantitative elemental analysis, that of instrumental neutron activation analysis (INAA), is the subject discussed, with reference to LODs. Particularly in the literature of neutron activation analysis (NAA), many tables of 'interference-free' NAA LODs are available. Not all of these are of much use, because (1) for many the definition used for LOD is not clear, or reasonable, (2) for many, the analysis conditions used are not clearly specified, and (3) for many, the analysis conditions used are specified, but not very practicable for most laboratories. For NAA work, such tables of interference-free LODs are, in any case, only applicable to samples in which, at the time of counting, only one radionuclide is present to any significant extent in the activated sample. It is important to note that tables of INAA LODs, per se, do not exist - since the LOD for a given element, under stated analysis conditions, can vary by orders of magnitude, depending on the elemental composition of the matrix in which it is present. For any given element, its INAA LOD will always be as large as, and usually much larger than, its tabulated 'interference-free' NAA LOD - how much larger depending upon the elemental composition of the matrix in which it is present. As discussed in this chapter, however, an INAA computer program exists that can calculate realistic INAA LODs for any elements of interest, in any kind of specified sample matrix, under any given set of analysis conditions