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Sample records for active mutator-like elements

  1. The protist Trichomonas vaginalis harbors multiple lineages of transcriptionally active Mutator-like elements

    Pereira Gonçalo AG

    2009-07-01

    Full Text Available Abstract Background For three decades the Mutator system was thought to be exclusive of plants, until the first homolog representatives were characterized in fungi and in early-diverging amoebas earlier in this decade. Results Here, we describe and characterize four families of Mutator-like elements in a new eukaryotic group, the Parabasalids. These Trichomonas vaginalis Mutator- like elements, or TvMULEs, are active in T. vaginalis and patchily distributed among 12 trichomonad species and isolates. Despite their relatively distinctive amino acid composition, the inclusion of the repeats TvMULE1, TvMULE2, TvMULE3 and TvMULE4 into the Mutator superfamily is justified by sequence, structural and phylogenetic analyses. In addition, we identified three new TvMULE-related sequences in the genome sequence of Candida albicans. While TvMULE1 is a member of the MuDR clade, predominantly from plants, the other three TvMULEs, together with the C. albicans elements, represent a new and quite distinct Mutator lineage, which we named TvCaMULEs. The finding of TvMULE1 sequence inserted into other putative repeat suggests the occurrence a novel TE family not yet described. Conclusion These findings expand the taxonomic distribution and the range of functional motif of MULEs among eukaryotes. The characterization of the dynamics of TvMULEs and other transposons in this organism is of particular interest because it is atypical for an asexual species to have such an extreme level of TE activity; this genetic landscape makes an interesting case study for causes and consequences of such activity. Finally, the extreme repetitiveness of the T. vaginalis genome and the remarkable degree of sequence identity within its repeat families highlights this species as an ideal system to characterize new transposable elements.

  2. Molecular characterization and diversity of a novel non-autonomous mutator-like transposon family in brassica

    Transposable elements (TEs) are capable of mobilizing from one genomic location to other, with changes in their copy numbers. Mutator-like elements (MULEs) are DNA transposons characterized by 9 bp target site duplications (TSDs), with high variability in sequence and length, and include non-conserved terminal inverted repeats (TIRs). We identified and characterized a family of Mutator-like elements designated as Shahroz. The structural and molecular analyses revealed that family had a small number of mostly defective non-autonomous MULEs and has shown limited activity in the evolutionary history of the Brassica A-genome. The Shahroz elements range in size from 2734 to 3160 bp including 76 bp imperfect TIRs and 9 bp variable TSDs. The individual copies have shown high homology (52-99%) in their entire lengths. The study revealed that the elements are less in numbers but active in Brassica rapa genomes and PCR amplification revealed their specificity and amplification in A-genome containing diploid and polyploids Brassica. The phylogenetic analysis of Brassica MULEs with other plant Mutator elements revealed that no correlation exists between Brassica MULEs and other elements suggesting a separate line of evolution. Analyzing the regions flanking the insertions revealed that the insertions have showed a preference for AT rich regions. The detailed study of these insertions revealed that although less in number and small sizes, they have played a role in Brassica genome evolution by their mobilization. (author)

  3. Microarray of programmable electrochemically active elements

    S. McCaskill, John; Maeke, Thomas; Straczek, Lukas; Oehm, Jürgen; Funke, Dominic; Mayr, Pierre; Sharma, Abhishek; Müller, Asbjørn; Tangen, Uwe; H. Packard, Norman; Rasmussen, Steen

    This paper describes possible applications of a two dimensional array of programmable electrochemically active elements to Alife. The array has been developed as part of the MICREA-gents project, and after several design phases, is now a mature enough device for general use beyond the project. He...

  4. Cooperation between core promoter elements influences transcriptional activity in vivo.

    Colgan, J.; Manley, J L

    1995-01-01

    Core promoters for RNA polymerase II frequently contain either (or both) of two consensus sequence elements, a TATA box and/or an initiator (Inr). Using test promoters consisting of prototypical TATA and/or Inr elements, together with binding sites for sequence-specific activators, we have analyzed the function of TATA and Inr elements in vivo. In the absence of activators, the TATA element was significantly more active than the Inr, and the combination of elements was only slightly more effe...

  5. Transpositionally active episomal hAT elements

    Hice Robert H

    2009-12-01

    Full Text Available Abstract Background hAT elements and V(DJ recombination may have evolved from a common ancestral transposable element system. Extrachromosomal, circular forms of transposable elements (referred to here as episomal forms have been reported yet their biological significance remains unknown. V(DJ signal joints, which resemble episomal transposable elements, have been considered non-recombinogenic products of V(DJ recombination and a safe way to dispose of excised chromosomal sequences. V(DJ signal joints can, however, participate in recombination reactions and the purpose of this study was to determine if hobo and Hermes episomal elements are also recombinogenic. Results Up to 50% of hobo/Hermes episomes contained two intact, inverted-terminal repeats and 86% of these contained from 1-1000 bp of intercalary DNA. Episomal hobo/Hermes elements were recovered from Musca domestica (a natural host of Hermes, Drosophila melanogaster (a natural host of hobo and transgenic Drosophila melanogaster and Aedes aegypti (with autonomous Hermes elements. Episomal Hermes elements were recovered from unfertilized eggs of M. domestica and D. melanogaster demonstrating their potential for extrachromosomal, maternal transmission. Reintegration of episomal Hermes elements was observed in vitro and in vivo and the presence of Hermes episomes resulted in lower rates of canonical Hermes transposition in vivo. Conclusion Episomal hobo/Hermes elements are common products of element excision and can be maternally transmitted. Episomal forms of Hermes are capable of integration and also of influencing the transposition of canonical elements suggesting biological roles for these extrachromosomal elements in element transmission and regulation.

  6. Encoding Active Device Elements at Nanowire Tips.

    No, You-Shin; Gao, Ruixuan; Mankin, Max N; Day, Robert W; Park, Hong-Gyu; Lieber, Charles M

    2016-07-13

    Semiconductor nanowires and other one-dimensional materials are attractive for highly sensitive and spatially confined electrical and optical signal detection in biological and physical systems, although it has been difficult to localize active electronic or optoelectronic device function at one end of such one-dimensional structures. Here we report a new nanowire structure in which the material and dopant are modulated specifically at only one end of nanowires to encode an active two-terminal device element. We present a general bottom-up synthetic scheme for these tip-modulated nanowires and illustrate this with the synthesis of nanoscale p-n junctions. Electron microscopy imaging verifies the designed p-Si nanowire core with SiO2 insulating inner shell and n-Si outer shell with clean p-Si/n-Si tip junction. Electrical transport measurements with independent contacts to the p-Si core and n-Si shell exhibited a current rectification behavior through the tip and no detectable current through the SiO2 shell. Electrical measurements also exhibited an n-type response in conductance versus water-gate voltage with pulsed gate experiments yielding a temporal resolution of at least 0.1 ms and ∼90% device sensitivity localized to within 0.5 μm from the nanowire p-n tip. In addition, photocurrent experiments showed an open-circuit voltage of 0.75 V at illumination power of ∼28.1 μW, exhibited linear dependence of photocurrent with respect to incident illumination power with an estimated responsivity up to ∼0.22 A/W, and revealed localized photocurrent generation at the nanowire tip. The tip-modulated concept was further extended to a top-down/bottom-up hybrid approach that enabled large-scale production of vertical tip-modulated nanowires with a final synthetic yield of >75% with >4300 nanowires. Vertical tip-modulated nanowires were fabricated into >50 individually addressable nanowire device arrays showing diode-like current-voltage characteristics. These tip

  7. Multi-element study in aluminium by activation analysis technique

    The instrumental activation analysis is a technique relatively quickly that help to know the elemental composition of materials. It is used mainly in the trace elements determination but in the case of major elements it is necessary to make some considerations as the different nuclear reactions carried out due to the neutron flux is a mixture of thermal and fast neutrons. This could be interpreted for the presence and or erroneous quantification about some elements. In this work, is described the way in which was analyzed a container piece with approximately a 85% of aluminium. The elements Zn, Mn, Sb, Ga, Cu, Cl and Sm were determined. (Author)

  8. Neutron induced activity in fuel element components

    A thorough investigation of the importance of various nuclides in neutron-induced radioactivity from fuel element construction materials has been carried out for both BWR and PWR fuel assemblies. The calculations were performed with the ORIGEN computer code. The investigation was directed towards the final storage of the assembly components and special emphasis was put to the examination of the sources of carbon-14, cobalt-60, nickel-59, nickel-63 and zirconium-93/niobium-93m. It is demonstrated that the nuclides nickel-59, in Inconel and stainless steel, and zirconium-93/niobium-93m, in Zircaloy, are the ones which constitute the very long term radiotoxic hazard of the irradiated materials. (author)

  9. Finite element models applied in active structural acoustic control

    Oude Nijhuis, Marco H.H.; Boer, de André; Rao, Vittal S.

    2002-01-01

    This paper discusses the modeling of systems for active structural acoustic control. The finite element method is applied to model structures including the dynamics of piezoelectric sensors and actuators. A model reduction technique is presented to make the finite element model suitable for controll

  10. Active pixel sensors with substantially planarized color filtering elements

    Fossum, Eric R. (Inventor); Kemeny, Sabrina E. (Inventor)

    1999-01-01

    A semiconductor imaging system preferably having an active pixel sensor array compatible with a CMOS fabrication process. Color-filtering elements such as polymer filters and wavelength-converting phosphors can be integrated with the image sensor.

  11. The characteristics of photo-activation of light elements

    The paper discusses the photo-activation of light elements and presents a study of nuclear physical constants for photo-activation analysis. The light elements were chosen because their nuclei have a distinct fine structure in the photonuclear reaction cross-sections and because they are difficult to determine by neutron activation analysis. The nuclear physical data was compiled from earlier published papers and is presented in table form. The following data is included in the table: 1) isotope studied; 2) properties of photoactivation products, including type of photonuclear reaction, element symbol, mass number and half-life of the isotope, radiation energy and radiation yield (β-, γ and β+; yield is expressed as % of total decay); 3) photo-activation cross-section parameters

  12. Determination of mutually interfering elements in activation analysis

    The determination of the elements present in the groups scandium-zinc, mercury-selenium and arsenic-antimony-bromine represents a classical problem in thermal neutron activation analysis because the gamma-ray peaks of the radioisotopes produced from these elements by activation appear very close in the spectrum. A study is made of the possibility of simultaneous instrumental determination of these elements by means of the spectrum stripping technique, using a 400-channel analyser coupled to a Nal(Tl) detector and a 4096-channel analyser coupled to a Ge(Li) detector. Artificial mixtures of the interfering elements in varying proportions are prepared, so as to reproduce possible real samples, where the elements may be present at several concentrations. Radiochemical separation techniques for the cited elements are studied with the use of tracers. For the separation of scadium and zinc, the technique of extraction chromatography is applied. The separation of mercury and selenium is accomplished by means of ion exchange. The technique of coprecipitation is used to separate bromine from arsenic and antimony followed by ion exchange to isolate these two elements from each other. The precision and the accuracy of the results are discussed. (Author)

  13. Finite element models applied in active structural acoustic control

    Oude Nijhuis, Marco H.H.; de Boer; Rao, Vittal S.

    2002-01-01

    This paper discusses the modeling of systems for active structural acoustic control. The finite element method is applied to model structures including the dynamics of piezoelectric sensors and actuators. A model reduction technique is presented to make the finite element model suitable for controller design. The reduced structural model is combined with an acoustic model which uses the radiation mode concept. For a test case consisting of a rectangular plate with one piezo patch the model re...

  14. Superluminescence in slablike Nd-glass active elements

    Borovskii, A.V.; Galkin, A.L.; Korobkin, V.V.; Mokrov, V.B.; Morozov, A.V. (Institut Obshchei Fiziki, Moscow (USSR))

    1990-11-01

    The effect of superluminescent emission (SE) on the energy stored in a slablike Nd-glass active element (AE) during the optical pumping process is examined. A mathematical model and numerical methods are developed for calculating the spatial-temporal distribution of the inversion in the AE, taking the SE into account. Optical pumping efficiency is investigated numerically at various powers for a slablike AE with dimensions Lx x Ly x Lz = 72 x 24 x 4 cm. The SE is shown to be the main mechanism that limits inversion and energy storage in such active elements. 21 refs.

  15. Trace elements in coloured opals using neutron activation analysis

    McOrist, G.D.; Smallwood, A. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    1996-12-31

    Neutron activation analysis (NAA) is a technique particularly suited to analysing opals since it is non-destructive and the silica matrix of opals is not prone to significant activation. It was used to determine the concentration of trace elements in 50 samples of orange, yellow, green, blue and pink opals as well as 18 samples of colourless opals taken from a number of recognised fields in Australia, Peru, Mexico and USA. The results were then evaluated to determine if a relationship existed between trace element content and opal colour. The mean concentration of most of the elements found in orange, yellow and colourless opals were similar with few exceptions. This indicated that, for these samples, colour is not related to the trace elements present. However, the trace element profile of the green, pink and blue opals was found to be significantly different with each colour having a much higher concentration of certain trace elements when compared with all other opals analysed. 7 refs.

  16. Finite-element model of the active organ of Corti.

    Ni, Guangjian; Elliott, Stephen J; Baumgart, Johannes

    2016-02-01

    The cochlear amplifier that provides our hearing with its extraordinary sensitivity and selectivity is thought to be the result of an active biomechanical process within the sensory auditory organ, the organ of Corti. Although imaging techniques are developing rapidly, it is not currently possible, in a fully active cochlea, to obtain detailed measurements of the motion of individual elements within a cross section of the organ of Corti. This motion is predicted using a two-dimensional finite-element model. The various solid components are modelled using elastic elements, the outer hair cells (OHCs) as piezoelectric elements and the perilymph and endolymph as viscous and nearly incompressible fluid elements. The model is validated by comparison with existing measurements of the motions within the passive organ of Corti, calculated when it is driven either acoustically, by the fluid pressure or electrically, by excitation of the OHCs. The transverse basilar membrane (BM) motion and the shearing motion between the tectorial membrane and the reticular lamina are calculated for these two excitation modes. The fully active response of the BM to acoustic excitation is predicted using a linear superposition of the calculated responses and an assumed frequency response for the OHC feedback. PMID:26888950

  17. 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

  18. Random isolation of gene activator elements from the human genome.

    Hamada, H

    1986-01-01

    Long-range-acting gene activator elements were randomly isolated from the human genome by functional selection. HeLa cells were transfected with an enhancer trap, a plasmid containing an enhancerless xanthine-guanosine phosphoribosyltransferase (gpt) gene transcribed from the simian virus 40 early promoter, and stably transformed GPT+ cells were selected. From several transformants, human DNA sequences flanking the enhancer trap were cloned. Two gene activators (GA1 and GA2) were found in the...

  19. Finite element model of the active organ of Corti

    Ni, Guangjian; Elliott, Stephen; Baumgart, Johannes

    2016-01-01

    The cochlear amplifier that provides our hearing with its extraordinary sensitivity and selectivity is thought to be the result of an active biomechanical process within the sensory auditory organ, the organ of Corti. Although imaging techniques are developing rapidly, it is not currently possible, in a fully active cochlea, to obtain detailed measurements of the motion of individual elements within a cross section of the organ of Corti. This motion is predicted using a two-dimensi...

  20. Studies on tender wheatgrass: estimation of elemental content, bioaccessibility of essential elements and antioxidant activity

    Tender wheatgrass is being consumed by human beings in juice form or as it is due to its antioxidant potential and medicinal value. Systematic studies were carried out to (i) estimate elemental profiles as a function of growth period and conditions, bioaccessibility of different elements and the antioxidant potential of the tender wheatgrass, (ii) determine the optimum growth period for obtaining maximum benefit and (iii) examine the possible correlation between antioxidant potential and mineral content. Wheatgrass was grown in four different conditions namely (i) tap water, (ii) tap water with nutrients, (iii) soil and tap water and (iv) soil with nutrient solution. The studies were carried out on the wheatgrass of 5-20 days old. For comparison with laboratory grown wheatgrass, a set of commercially available wheatgrass tablets and wheat seeds were also studied. Instrumental neutron activation analysis (INAA) was used for concentration determination of elements in the wheatgrass, wheat seeds and wheatgrass tablets. A total of 15 elements like Na, K, Ca, Mg, Mn, Br, Fe and Zn were determined in the samples of shoots and roots of tender wheatgrass. A comparison with the recommended dietary allowance (RDA) of different essential elements with that in tender wheatgrass revealed that wheatgrass is a good source of minerals for health benefits rather than a food supplement. Bioaccessible fractions of various elements were estimated by a chemical NAA method by subjecting the samples to in vitro gastric and gastro-intestinal digestion followed by NAA. The bioaccessibility concentrations by both the measurements were in the range of 9-60%. It was found that bioaccessibility of the elements studied was the highest from fresh wheatgrass and the lowest from wheat seeds. Accuracy of the NAA method was evaluated by analyzing two biological reference materials, SRM 1573a (Tomato leaves) from NIST, USA and ICHTJ CTA-vtl-2 (Tobacco leaves) from INCT, Poland. The antioxidant

  1. Elemental characterization of Brazilian beans using neutron activation analysis

    Beans are important for many developing countries as a source of protein and mineral nutrients. Here, ten commercial types of Brazilian beans, from the species Phaseolus vulgaris (common beans) and Vigna unguiculata (cowpeas), were analyzed by neutron activation analysis for the determination of Br, Ca, Co, Cs, Fe, K, Mo, Na, Rb, Sc and Zn. There were statistical differences (p/0.05) amongst the commercial types, except for Br, Rb and Sc. In general, non-essential elements showed high variability, indicating that the origin of beans had a strong influence on the mass fraction of such elements. (author)

  2. 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

  3. Neutron activation analysis of traces of metallic elements in water

    The application of neutron activation analysis is examined for the elements iron, nickel, chromium and cobalt which are constituents of the aqueous corrosion products of stainless steels and which are present in very low concentrations in the water used in the heat transfer systems of nuclear reactors. The best results were obtained by slow evaporation of the water sample in a quartz ampoule in an oven followed by irradiation of the dry sample in the same ampoule. The problems of blanks, of losses during concentration, and of conservation of solutions at very low concentrations were studied. Good agreement was found between the theoretical quantities and experimental results with standard samples containing 50ppb of each of the studied elements. There was also excellent agreement between neutron activation and spectrophotometric methods in the case of determinations of iron in solution

  4. Gaussian-state interferometry with passive and active elements

    C. Sparaciari; Olivares, S.; Paris, M. G. A.

    2016-01-01

    We address precision of optical interferometers fed by Gaussian states and involving passive and/or active elements, such as beam splitters, photodetectors and optical parametric amplifiers. We first address the ultimate bounds to precision by discussing the behaviour of the quantum Fisher information. We then consider photodetection at the output and calculate the sensitivity of the interferometers taking into account the non unit quantum efficiency of the detectors. Our results show that in...

  5. Gaussian state interferometry with passive and active elements

    Sparaciari, Carlo; Olivares, Stefano; Paris, Matteo G. A.

    2015-01-01

    We address precision of optical interferometers fed by Gaussian states and involving passive and/or active elements, such as beam splitters, photodetectors and optical parametric amplifiers. We first address the ultimate bounds to precision by discussing the behaviour of the quantum Fisher information. We then consider photodetection at the output and calculate the sensitivity of the interferometers taking into account the non unit quantum efficiency of the detectors. Our results show that in...

  6. 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)

  7. Matching Element Symbols with State Abbreviations: A Fun Activity for Browsing the Periodic Table of Chemical Elements

    Woelk, Klaus

    2009-01-01

    A classroom activity is presented in which students are challenged to find matches between the United States two-letter postal abbreviations for states and chemical element symbols. The activity aims to lessen negative apprehensions students might have when the periodic table of the elements with its more than 100 combinations of letters is first…

  8. Nuclear Thermal Rocket Element Environmental Simulator (NTREES) Upgrade Activities

    Emrich, William J., Jr.

    2014-01-01

    Over the past year the Nuclear Thermal Rocket Element Environmental Simulator (NTREES) has been undergoing a significant upgrade beyond its initial configuration. The NTREES facility is designed to perform realistic non-nuclear testing of nuclear thermal rocket (NTR) fuel elements and fuel materials. Although the NTREES facility cannot mimic the neutron and gamma environment of an operating NTR, it can simulate the thermal hydraulic environment within an NTR fuel element to provide critical information on material performance and compatibility. The first phase of the upgrade activities which was completed in 2012 in part consisted of an extensive modification to the hydrogen system to permit computer controlled operations outside the building through the use of pneumatically operated variable position valves. This setup also allows the hydrogen flow rate to be increased to over 200 g/sec and reduced the operation complexity of the system. The second stage of modifications to NTREES which has just been completed expands the capabilities of the facility significantly. In particular, the previous 50 kW induction power supply has been replaced with a 1.2 MW unit which should allow more prototypical fuel element temperatures to be reached. The water cooling system was also upgraded to so as to be capable of removing 100% of the heat generated during. This new setup required that the NTREES vessel be raised onto a platform along with most of its associated gas and vent lines. In this arrangement, the induction heater and water systems are now located underneath the platform. In this new configuration, the 1.2 MW NTREES induction heater will be capable of testing fuel elements and fuel materials in flowing hydrogen at pressures up to 1000 psi at temperatures up to and beyond 3000 K and at near-prototypic reactor channel power densities. NTREES is also capable of testing potential fuel elements with a variety of propellants, including hydrogen with additives to inhibit

  9. Real-time transposable element activity in individual live cells.

    Kim, Neil H; Lee, Gloria; Sherer, Nicholas A; Martini, K Michael; Goldenfeld, Nigel; Kuhlman, Thomas E

    2016-06-28

    The excision and reintegration of transposable elements (TEs) restructure their host genomes, generating cellular diversity involved in evolution, development, and the etiology of human diseases. Our current knowledge of TE behavior primarily results from bulk techniques that generate time and cell ensemble averages, but cannot capture cell-to-cell variation or local environmental and temporal variability. We have developed an experimental system based on the bacterial TE IS608 that uses fluorescent reporters to directly observe single TE excision events in individual cells in real time. We find that TE activity depends upon the TE's orientation in the genome and the amount of transposase protein in the cell. We also find that TE activity is highly variable throughout the lifetime of the cell. Upon entering stationary phase, TE activity increases in cells hereditarily predisposed to TE activity. These direct observations demonstrate that real-time live-cell imaging of evolution at the molecular and individual event level is a powerful tool for the exploration of genome plasticity in stressed cells. PMID:27298350

  10. Real-time transposable element activity in individual live cells

    Lee, Gloria; Martini, K. Michael

    2016-01-01

    The excision and reintegration of transposable elements (TEs) restructure their host genomes, generating cellular diversity involved in evolution, development, and the etiology of human diseases. Our current knowledge of TE behavior primarily results from bulk techniques that generate time and cell ensemble averages, but cannot capture cell-to-cell variation or local environmental and temporal variability. We have developed an experimental system based on the bacterial TE IS608 that uses fluorescent reporters to directly observe single TE excision events in individual cells in real time. We find that TE activity depends upon the TE’s orientation in the genome and the amount of transposase protein in the cell. We also find that TE activity is highly variable throughout the lifetime of the cell. Upon entering stationary phase, TE activity increases in cells hereditarily predisposed to TE activity. These direct observations demonstrate that real-time live-cell imaging of evolution at the molecular and individual event level is a powerful tool for the exploration of genome plasticity in stressed cells. PMID:27298350

  11. Essential trace elements in edible mushrooms by Neutron Activation Analysis

    Mushrooms are excellent nutritional sources since they provide proteins, fibers and mineral, such as K, P, Fe. They have also been the focus of medical research. In Brazil mushrooms are not consumed in large quantities by the general population since people know little about the nutritional and medicinal benefits that mushrooms offer. Hence, this study intends to contribute to a better understanding of the essential element content in edible mushrooms, which are currently commercialized in Sao Paulo state. Br Fe, K, Na and Zn concentrations were determined by Instrumental Neutron Activation Analysis in the following mushroom species: Shitake (Lentinus edodes), Shimeji (Pleurotus ssp), Paris Champignon (Agaricus bisporus), Hiratake ( Pleurotus ssp) and Eringue (Pleurotus Eryngu. The mushroom samples were acquired from commercial establishments in the city of Sao Paulo and directly from the producers. Essential element contents in mushrooms varied between Br 0.03 to 4.1 mg/kg; Fe 20 to 267 mg/kg; K 1.2 to 5.3 g/kg, Na 10 to 582 mg/kg and Zn 60 to 120 mg/kg. The results confirm that mushrooms can be considered a good source of K, Fe and Zn. The low Na level is a good nutritional benefit for the consumer. (author)

  12. Essential trace elements in edible mushrooms by Neutron Activation Analysis

    Moura, Patricia L.C.; Maihara, Vera A.; Castro, Lilian P. de [Instituto de Pesquisa e Energetica e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: patricialandim@ig.com.br; vmaihara@ipen.br; lilian.Pavanelli@terra.com.br; Figueira, Rubens C.L. [Universidade Cruzeiro do Sul, Sao Paulo, SP (Brazil)]. E-mail: figueiraru@yahoo.com.br

    2007-07-01

    Mushrooms are excellent nutritional sources since they provide proteins, fibers and mineral, such as K, P, Fe. They have also been the focus of medical research. In Brazil mushrooms are not consumed in large quantities by the general population since people know little about the nutritional and medicinal benefits that mushrooms offer. Hence, this study intends to contribute to a better understanding of the essential element content in edible mushrooms, which are currently commercialized in Sao Paulo state. Br Fe, K, Na and Zn concentrations were determined by Instrumental Neutron Activation Analysis in the following mushroom species: Shitake (Lentinus edodes), Shimeji (Pleurotus ssp), Paris Champignon (Agaricus bisporus), Hiratake ( Pleurotus ssp) and Eringue (Pleurotus Eryngu. The mushroom samples were acquired from commercial establishments in the city of Sao Paulo and directly from the producers. Essential element contents in mushrooms varied between Br 0.03 to 4.1 mg/kg; Fe 20 to 267 mg/kg; K 1.2 to 5.3 g/kg, Na 10 to 582 mg/kg and Zn 60 to 120 mg/kg. The results confirm that mushrooms can be considered a good source of K, Fe and Zn. The low Na level is a good nutritional benefit for the consumer. (author)

  13. Neutron activation analysis of stable elements in marine algae

    The nuclear industry has grown during the last decades and continuing growth is predicted. Although considerable efforts are being made to minimize the release of the increasing amounts of radioactive wastes into marine environment, it is evident that the potential for radioactive contamination will continue to grow. The purposes of marine environment monitoring around nuclear facilities are to verify that they are functioning as it was designed and to detect the unplanned releases of radioactive contaminants. To provide a sufficient assessment with biological indicators of 60Co and 137Cs, most significant radionuclides in waste effluents released with nuclear power station, the concentration of stable elements in the Sargassum and other algae were surveyed with thermal neutron activation method. The results were followed: 1) The concentration of Mn, As, Zn, and Co were seem to be higher in the sargassum than in other algae. 2) The concentration of Co and Cs were higher in S. thunbergit than in other Sargassum. (author)

  14. Instrumental Neutron Activation Analysis in archaeology interpretation beyond elemental abundance

    Application of instrumental neutron activation analysis to the study of archaeological ceramics involves the determination of the source or sources used to produce pottery. Groups of relatively homogeneous elemental abundances are shown to be statically distinct from one another often leading to the assesment of what was locally produced and what was imported to a site. These assesment, however are among the most preliminary interpretations. Archaeology is concerned with the reasons for artificial distributions and how and why the distribution varied through time 3 reasons that include the social and political basis of ancient economics and how these responded to other factors, such as ideology. These objectives are addressed through the increasing refinement of compositional groups leading toward greater specificity of attribution. In so doing the role of analytical precision among other considerations groves in importance. This paper illustration some of these considerations with examples from the U.S. southwest, the Maya region of southern mexico, and lower central America

  15. Fast-neutron activation analysis of light elements

    Full text: The determination of lithium, carbon, oxygen, nitrogen and other light chemical elements in various modern materials in microgram level is of importance for analytical science. As it is well-known, a thermal neutron activation of C, H, N, and O produces negligible γ-ray activity. 13C (n, γ) 14C and 2H (n, γ) 3H reactions produce very small activities of the non- γ- emitters 3H and 14C, and the 19O (n, γ)19O and 15N(n, γ)16N reactions give very short lived 19O (27 sec) and 16N (7.1 sec). All of these reactions have extremely low thermal neutron cross sections. Therefore a major advantage of the instrumental neutron activation analysis (INAA) is the determination of trace elements in biological, medical and environmental materials. For this reason the above mentioned problems are solved with use of some variants of nuclear analytical techniques based on application of charged particle accelerators. However, there are several non-traditional reactor activation analysis techniques to solve such problems which have been developed and applied in various fields of semiconductor industry, biology, geology. In recent years these techniques were named as the nuclear reactor based charged particles activation analysis (NRCPAA). We distinguished two possible applications of a nuclear reactor as charged particles source. During last years the capabilities of the NRCPAA were investigated intensively and some our results were applied to determine light elements contents [1,2]. The recoil protons are produced as the result of (n, p) elastic and inelastic scattering interaction of fast neutrons with nucleus of light elements, for example, hydrogen. These protons are applied for the development of proton activation analysis for the determination of large concentrations of Li, B and O. The non-destructive activation analysis with use of 14-MeV fast neutrons (FNAA) is the most suitable method for analysis of N, P and Si. FNAA was applied for determination of nitrogen

  16. Elemental analysis of brazing alloy samples by neutron activation technique

    Two brazing alloy samples (C P2 and C P3) have been investigated by Neutron activation analysis (NAA) technique in order to identify and estimate their constituent elements. The pneumatic irradiation rabbit system (PIRS), installed at the first egyptian research reactor (ETRR-1) was used for short-time irradiation (30 s) with a thermal neutron flux of 1.6 x 1011 n/cm2/s in the reactor reflector, where the thermal to epithermal neutron flux ratio is 106. Long-time irradiation (48 hours) was performed at reactor core periphery with thermal neutron flux of 3.34 x 1012 n/cm2/s, and thermal to epithermal neutron flux ratio of 79. Activation by epithermal neutrons was taken into account for the (1/v) and resonance neutron absorption in both methods. A hyper pure germanium detection system was used for gamma-ray acquisitions. The concentration values of Al, Cr, Fe, Co, Cu, Zn, Se, Ag and Sb were estimated as percentages of the sample weight and compared with reported values. 1 tab

  17. Epithermal neutron activation analysis of trace elements in biological materials

    The detection limits of 24 important minor and trace elements were studied in NBS SRM-1571 Orchard Leaves, NBS SRM-1577 Bovine Liver, Bowen's kale and IAEA H-4 Animal Muscle using ENAA method with cadmium and cadmium-boron filter. The lower detection limits have been found for elements As, Au, Ba, Br, Cd, Mo, Ni, Sb, Se, Sm and U by ENAA with cadmium filter and for elements As, Cd, Mo and Ni by ENAA with cadmium-boron filter, respectively, in comparison with INAA method. The results of the determination of elements studied in the above mentioned biological materials are also presented. (author)

  18. Neutron activation analysis of trace elements in Japanese hormesis cosmetics

    In Japan, cosmetics claiming hormesis effect are available through Internet. Although these cosmetics show the contents, they never mention the minor elements and radioactive sources. The existence of radioisotopes, however, was observed by measurements of the gamma-rays with a HPGe detector. In this study, in order to clarify the contents of trace elements, the hormesis cosmetics including radioactive sources were analyzed using INAA, PGAA and NAA with multiple gamma-ray detection (NAAMG). Nineteen elements were analyzed quantitatively in hormesis cosmetics by INAA, PGAA and NAAMG and 16 elements were detected qualitatively by SEM-EPMA. (author)

  19. Elemental profiles of soil in and around Tirupati by reactor neutron activation using KO method

    Soil samples, representatives of various places in and around Tirupati, Andhra Pradesh, that are affected by industrial effluents and sewages, were analysed for the elemental profiles by neutron activation analysis (NAA) using Ko method. Concentrations of 23 elements were measured. Variation in concentration of important elements with respect to influence on vegetation is discussed. (author). 2 refs., 1 tab

  20. Optimization of mass multi-element activation analysis

    Existing and newly proposed criteria of γ-spectrometric experiment optimization are investigated, on the basis of which optimal analytical methods for mass multi-element analysis of soils and plants using 14 MeV energy fast neutrons are developed and introduced. The task of multi-element analysis optimization is limited to a consistent application of criteria, corresponding to single-element analysis. Dependences of optimization criteria on the holding time are studied. Optimal time regimes for soil and plant analysis are calculated. Under the optimal time regime the obtained statistical errors for Si, Al, Fe determination do not exceed 1%, and Mg - 5-10% for the most types of soils

  1. Finite Element Learning Modules as Active Learning Tools

    Brown, Ashland O.; Jensen, Daniel; Rencis, Joseph; Wood, Kristin; Wood, John; White, Christina; Raaberg, Kristen Kaufman; Coffman, Josh

    2012-01-01

    The purpose of active learning is to solicit participation by students beyond the passive mode of traditional classroom lectures. Reading, writing, participating in discussions, hands-on activities, engaging in active problem solving, and collaborative learning can all be involved. The skills acquired during active learning tend to go above and…

  2. ELEMENTAL MERCURY ADSORPTION BY ACTIVATED CARBON TREATED WITH SULFURIC ACID

    The paper gives results of a study of the adsorption of elemental mercury at 125 C by a sulfuric-acid (H2S04, 50% w/w/ solution)-treated carbon for the removal of mercury from flue gas. The pore structure of the sample was characterized by nitrogen (N2) at -196 C and the t-plot m...

  3. Trace element evaluation of different varieties of chewing gum by radiochemical neutron activation analysis

    Extensive use of chewing gums, by children in particular, entails the evaluation of trace element contents in them. Radiochemical neutron activation analysis (RNAA) was successfully employed to determine the concentration of 35 trace elements (essential, toxic and nonessential) in eight different brands of chewing gum generally consumed in Rawalpindi/Islamabad area. Comparison of trace element data of our work with literature has been presented. None of the elements detected in the brands of chewing gum examined was found to be present at a level representing a substantial contribution to the total dietary intake of the element. (author)

  4. Study on the chemical species of platinum group elements in geological samples by molecular activation analysis

    The chemical species of platinum group elements in some upper mantle-derived xenoliths from Eastern China are studied by molecular activation analysis, in which the chemical stepwise dissolution, nickel fire assay preconcentration and neutron activation analysis are jointly applied. The weighted sums of platinum group elements in 6 phases are in agreement with their total contents. The distribution patterns of platinum group elements in sulphides show that sulphide segregation is one of the important mechanisms for the fractionation of platinum group elements in upper mantle-derived material during partial melting

  5. Optical activity of catalytic elements of hetero-metallic nanostructures

    Antosiewicz, Tomasz J.; Apell, S. Peter; Wadell, Carl; Langhammer, Christoph

    2015-05-01

    Interaction of light with metals in the form of surface plasmons is used in a wide range of applications in which the scattering decay channel is important. The absorption channel is usually thought of as unwanted and detrimental to the efficiency of the device. This is true in many applications, however, recent studies have shown that maximization of the decay channel of surface plasmons has potentially significant uses. One of these is the creation of electron-hole pairs or hot electrons which can be used for e.g. catalysis. Here, we study the optical properties of hetero-metallic nanostructures that enhance light interaction with the catalytic elements of the nanostructures. A hybridized LSPR that matches the spectral characteristic of the light source is excited. This LSPR through coupling between the plasmonic elements maximizes light absorption in the catalytic part of the nanostructure. Numerically calculated visible light absorption in the catalytic nanoparticles is enhanced 12-fold for large catalytic disks and by more 30 for small nanoparticles on the order of 5 nm. In experiments we measure a sizable increase in the absorption cross section when small palladium nanoparticles are coupled to a large silver resonator. These observations suggest that heterometallic nanostructures can enhance catalytic reaction rates.

  6. Elemental analysis of human serum and serum protein fractions by thermal neutron activation

    Some applications of thermal neutron activation for the determination of elemental contents in human serum and human serum protein fractions are presented. Firstly total serum is dealt with, secondly serum protein fractions obtained by gel filtration are described. A brief review on the role of (trace) elements in human health and disease and a compilation of literature data for elemental contents in human serum, as obtained by neutron activation techniques, are given. The most important sources of statistical and systematic errors are evaluated. Results for the contents of sodium, potassium, magnesium, bromine, iron, copper, zinc, selenium, rubidium, cesium and antimony in serum are given, with emphasis on control of accuracy and precision. The possible relation between selenium in blood and cancer occurrence in humans is discussed. The results of elemental analyses from cancer patients and from a patient receiving a cytostatic treatment are presented. A survey of literature results for the determination of protein-bound elemental contents in serum is presented. Subsequently, results from a study on the behaviour of elements during gel filtration are discussed. Gel-element and protein-element interactions are studied. Finally the protein-bound occurrence of trace elements in human serum is determined by gel filtration and neutron activation analysis. Results for both desalting and fractionation are given, for the elements bromine, copper, manganese, vanadium, selenium, zinc, rubidium, iron and iodine. (Auth.)

  7. Exercise and Activity: Key Elements in the Management of OI

    ... problems can include bowing of the long bones, scoliosis (curvature of the spine), a barrel chest, and ... Activity programs may include specific exercises recommended by rehabilitation professionals (physiatrists, physical therapists, occupational therapists, and recreation ...

  8. Anodic Activation of Aluminum by Trace Element Tin

    Tan, Juan

    2011-01-01

    Anodic activation of commercial and model aluminum alloys in chloride solution became of practical importance in connection with filiform corrosion of painted aluminum sheet in architectural application and aluminum components of brazed heat exchangers. Activation in chloride solution manifests itself in the form of a significant negative shift in the pitting potential relative to pure aluminum and a significant increase in the anodic current output at potentials where aluminum is normally ex...

  9. Trace element analysis of human head hair by neutron activation technique

    28 elements in reference hair sample (HH-1) and 44 hair samples of Seoul, Korea have been analyzed by instrumental neutron activation analysis. The analytical results of reference sample agreed well with those of the IAEA report within 10% deviation except those of some elements. For the 44 hair samples of Seoul, the range of content of each element is fallen in +-3σ from his mean value if rejecting one or two of the highest data. (author)

  10. Possible use of neutron activation analysis in studying trace elements in senile cataracts

    The effect of certain life parameters (age, sex, place of residence) on the occurrence of trace elements in turpid human lens (senile cataract) was studied using instrumental neutron activation analysis. The results obtained suggest the dependence of some trace elements deposition in cataracts on age, sex and residence. The work was motivated by the aim to search for possible correlation between the environment and trace elements deposition in eye cataracts. (author)

  11. Monitoring Australian foodstuffs for toxic and essential trace elements using neutron activation analysis

    A total of nine toxic elements are listed in current Australian legislation for maximum permitted levels in foodstuffs. In addition, the National Health and Medical Research Council (NH and MRC) have published date for the recommended dietary intake of seven essential elements. The use of neutron activation analysis to monitor the levels of these toxic and essential elements in 350 food samples gathered around Australia as a part of the NH and MRC's Market Basket Survey is reviewed. 4 refs

  12. Determination of trace elements in chewing gum by neutron activation analysis

    Six trace elements of nutritional or toxicological interest (Al, Ca, Cl, Mn, Na and Sr) were determined in three different brands of chewing gum by instrumental neutron activation analysis. For the particular brands of gum examined, none of the detected elements was found to be present at a level representing a substantial contribution to the total dietary intake of the element for an American adult. (author) 11 refs.; 3 tabs

  13. Speciation analysis of trace elements, radionuclides, macromolecules and nanoparticles using neutron activation and synchrotron radiation

    Speciation analysis is defined by IUPAC as the analytical activities of identifying and/or measuring the quantities of one or more individual chemical species in a sample. It includes isotopic composition of an element, electronic and oxidation states of an element, distribution of an element among different inorganic complexes, and compounds, organometallic compounds, macromolecular compounds and complexes. In this lecture we will describe the methods developed in our laboratory to separate

  14. Impact of detector-element active-area shape and fill factor on super-resolution

    Russell C. Hardie; Douglas R. Droege; Alexander J Dapore; Mark E Greiner

    2015-01-01

    In many undersampled imaging systems, spatial integration from the individual detector elements is the dominant component of the system point spread function (PSF). Conventional focal plane arrays (FPAs) utilize square detector elements with a nearly 100% fill factor, where fill factor is defined as the fraction of the detector element area that is active in light detection. A large fill factor is generally considered to be desirable because more photons are collected for a given pitch, and t...

  15. Neutron activation analysis of toxic elements in meat and farinaceous food of Argentina

    Quantitative information about the concentration of toxic elements in foodstuffs for human consumption is important for the study of human health and diseases. Our project is to analyze, by neutron activation, toxic elements im meat and farinaceous food of Argentina by means of: a) Radiochemical neutron activation analysis with development of an adequate technique for the determination of As, Se, Sb and Hg in farinaceous food and manufactured meat (sausages and hamburgers); b) Instrumental neutron activation analysis of Rb, Se, Br, Fe, Co and Zn in farinaceous food and manufactured meat; c) Preliminary studies of the daily intake of the determined elements. 5 refs, 3 figs, 17 tabs

  16. Retention of elemental 131I by activated carbons under accident conditions

    Under simulated accident conditions (maximum temperature: 1300C) no significant difference was found in the retention of I-131 loaded as elemental iodine, by various fresh and aged commercial activated carbons. In all the cases, the I-131 passing through deep beds of activated carbon was in a non-elemental form. It is concluded that a minimum retention of 99.99% for elemental radioiodine, as required by the RSK guidelines for PWR accident filters, can be equally well achieved with various commercial activated carbons. (orig.)

  17. 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 AV ČR KSK4055109 Keywords : neutron-activation * edible mushrooms * heavy metals Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 0.457, year: 2004

  18. Activation analysis and isotope dilution applied to the determination of rare earth elements in ytrium oxides

    A method for determining rare earth elements from matrix constituted by sample of ytrium oxide is shown. Ion exchange technique and electron with chelating agent have been chosen for chemical separations. The method consists of using isotope dilution followed by activation analysis in order to determine the amounts of the elements

  19. The characterization of activities associated with irradiated fuel element claddings

    The object of the present work was to characterise the natures and amounts of the various α and βγ activities associated with cladding hulls. The claddings studied were stainless steel from a Fast Reactor and from an Advanced Gas Reactor and Zircaloy from a Boiling Water Reactor, from a Pressurized Water Reactor and from a Steam Generating Heavy Water Reactor. The hulls were examined by the following methods: alpha spectrometry to identify and quantify the α emitters and to estimate their depths of penetration, partial and complete dissolution of hulls followed by gross α counting, α spectrometry and γ spectrometry, fission track autoradiography to determine the distribution of fissile material associated with hulls, neutron activation to determine the total fissile content of the hulls, chemical separations followed by β counting and chemical treatment with various reagents to examine the ease of decontamination

  20. Environmental Contaminants Monitoring in Selected Wetlands of Wyoming: Biologically Active Elements Study

    US Fish and Wildlife Service, Department of the Interior — Sediment, water and biota were collected from selected wetlands in Wyoming for the Biologically Active Elements (BAE) Study in 1988, 1989 and 1990 to identify...

  1. Determination of trace elements in bottled water in Greece by instrumental and radiochemical neutron activation analyses

    Four different bottled water brands sold in Greece in the winter of 2001-2002 were analyzed for a wide range of chemical elements, using neutron activation analysis (NAA). The elements Na and Br were determined instrumentally (INAA), whereas the other metals and trace elements radiochemically (RNAA). The results indicated that the mean level of all the elements determined in the samples were well within the European Union (EU) directive on drinking water and accomplish the drinking water standards of the World Health Organisation (WHO) as well as of the Food and Drug Administration (FDA). (author)

  2. Optimal placement of active elements in control augmented structural synthesis

    Sepulveda, A. E.; Jin, I. M.; Schmit, L. A., Jr.

    1992-01-01

    A methodology for structural/control synthesis is presented in which the optimal location of active members is treated in terms of (0,1) variables. Structural member sizes, control gains and (0,1) placement variables are treated simultaneously as design variables. Optimization is carried out by generating and solving a sequence of explicit approximate problems using a branch and bound strategy. Intermediate design variable and intermediate response quantity concepts are used to enhance the quality of the approximate design problems. Numerical results for example problems are presented to illustrate the efficacy of the design procedure set forth.

  3. The Element Effect Revisited: Factors Determining Leaving Group Ability in Activated Nucleophilic Aromatic Substitution Reactions

    Senger, Nicholas A.; Bo, Bo; Cheng, Qian; Keeffe, James R.; Gronert, Scott; Wu, Weiming

    2012-01-01

    The “element effect” in nucleophilic aromatic substitution reactions (SNAr) is characterized by the leaving group order, F > NO2 > Cl ≈ Br > I, in activated aryl halides. Multiple causes for this result have been proposed. Experimental evidence shows that the element effect order in the reaction of piperidine with 2,4-dinitrophenyl halides in methanol is governed by the differences in enthalpies of activation. Computational studies of the reaction of piperidine and dimethylamine with the same...

  4. Finite element modeling of stiffened piezolaminated plates and shells with piezoelectric layers for active vibration control

    In this paper, a piezolaminated stiffened shell element is formulated. This piezoelectric shell element is a 9-noded, isoparametric, shear flexible and field-consistent element with five elastic degrees of freedom at each node and one electric degree of freedom per element per piezoelectric layer. The stiffener element is a three-noded isoparametric beam element with three degrees of freedom at each node. The effect of the stiffener is incorporated by internally constraining the stiffener displacement fields to the relevant shell displacement fields and hence this formulation allows the positioning of the stiffener element anywhere within the shell element along lines of natural coordinates, which gives a great flexibility in the choice of the mesh size. This stiffened shell element is validated for static deflection and dynamic response with the results available in literature. The active control performance of the stiffened composite plate and shell structures with distributed piezoelectric sensors and actuators are studied using a number of examples. The active vibration control is carried out using the LQR optimal control

  5. Transposon display supports transpositional activity of elements in species of the saltans group of Drosophila

    Nathalia De Setta; Ana Paula Pimentel Costa; Fabrício Ramon Lopes; Marie-Anne Van Sluys; Cláudia Márcia Aparecida Carareto

    2007-01-01

    Mobilization of two element subfamilies (canonical and O-type) from Drosophila sturtevanti and D. saltans was evaluated for copy number and transposition activity using the transposon display (TD) technique. Pairwise distances between strains regarding the insertion polymorphism profile were estimated. Amplification of the element based on copy number estimates was highly variable among the strains (D. sturtevanti, canonical 20.11, O-type 9.00; D. saltans, canonical 16.4, O-type 12.60 insertions, on average). The larger values obtained by TD compared to our previous data by Southern blotting support the higher sensitivity of TD over Southern analysis for estimating transposable element copy numbers. The higher numbers of the canonical element and the greater divergence in its distribution within the genome of D. sturtevanti (24.8%) compared to the O-type (16.7%), as well as the greater divergence in the distribution of the canonical P element, between the D. sturtevanti (24.8%) and the D. saltans (18.3%) strains, suggest that the canonical element occupies more sites within the D. sturtevanti genome, most probably due to recent transposition activity. These data corroborate the hypothesis that the O-type is the oldest subfamily of elements in the saltans group and suggest that the canonical element is or has been transpositionally active until more recently in D. sturtevanti.

  6. Concentration of 24 Trace Elements in Human Heart Tissue Determined by Neutron Activation Analysis

    Wester, P.O.

    1964-06-15

    By means of neutron-activation analysis, human heart tissue from autopsy of 20 victims of traumatic accidents has been investigated with respect to the concentration of 24 different trace elements. A recently developed ion-exchange technique combined with gamma spectrometry has been used, which permits simultaneous determination of a large number of trace elements. The following trace elements have been determined quantitatively: Ag, As, Au, Ba, Br; Ca, Cd, Ce, Co, Cr, Cs, Cu, Fe, Hg, La, Mo, Pt, Rb, Sb, Se, Se, Sm, Zn, W. In some heart samples, Hf and Os were determined qualitatively. The mean and standard deviation are given for the elements Cu, Fe, Se and Zn, Since none of the other quantitatively determined trace elements were normally distributed, the median is given as the central value. When possible, comparisons with values from other investigations have been made. No marked differences in the trace-element concentrations with age or sex could be detected.

  7. Concentration of 24 Trace Elements in Human Heart Tissue Determined by Neutron Activation Analysis

    By means of neutron-activation analysis, human heart tissue from autopsy of 20 victims of traumatic accidents has been investigated with respect to the concentration of 24 different trace elements. A recently developed ion-exchange technique combined with gamma spectrometry has been used, which permits simultaneous determination of a large number of trace elements. The following trace elements have been determined quantitatively: Ag, As, Au, Ba, Br; Ca, Cd, Ce, Co, Cr, Cs, Cu, Fe, Hg, La, Mo, Pt, Rb, Sb, Se, Se, Sm, Zn, W. In some heart samples, Hf and Os were determined qualitatively. The mean and standard deviation are given for the elements Cu, Fe, Se and Zn, Since none of the other quantitatively determined trace elements were normally distributed, the median is given as the central value. When possible, comparisons with values from other investigations have been made. No marked differences in the trace-element concentrations with age or sex could be detected

  8. Determination of elemental concentrations in environmental plant samples by instrumental neutron activation analysis

    The intake of leafy vegetables in daily diet is very important to meet our nutritional needs. Vegetables provide the essential elements which are necessary and recommended for human growth. However, due to rapid industrialization and urbanization our environment becomes polluted and this affects the normal growth of agricultural products and composition of environmental species. The elemental concentrations present in the environmental samples are good indicators to assess the toxicological levels due to pollution affects. In the present work we have analysed several vegetable plant samples by instrumental neutron activation analysis to determine the elemental concentrations at major, minor and trace levels. The leafy vegetables like spinach, red leafy vegetable, pui, gourd leaf, lettuce and katoua were chosen as these are extensively consumed by local people in eastern part of India. We have determined 15 elements in the above mentioned vegetable samples and some of these are essential elements and some are toxic elements. It was found that Na and K were present as major elements, Fe and Zn as minor elements and As, Ce, Cr, Co, La, Mo, Rb, Sc, Sm, Sr as trace elements. The concentration level of Cr was found to be higher than that of recommended value certified by WHO and National environment quality control for human consumption. The validation of our analytical results have been performed by the Z-score tests through the determination of concentrations of the elements of interest in certified reference materials. (author)

  9. Active Elements for Analog Signal Processing: Classification, Review, and New Proposals

    Z. Kolka

    2008-12-01

    Full Text Available In the paper, an analysis of the state-of-the-art of active elements for analog signal processing is presented which support – in contrast to the conventional operational amplifiers – not only the voltage-mode but also the current- and mixed-mode operations. Several problems are addressed which are associated with the utilization of these elements in linear applications, particularly in frequency filters. A methodology is proposed which generates a number of fundamentally new active elements with their potential utilization in various areas of signal processing.

  10. Efficient LEC2 activation of OLEOSIN expression requires two neighboring RY elements on its promoter

    CHE NanYing; YANG Yang; LI YanDong; WANG LiLi; HUANG Ping; GAO Yin; An ChengCai

    2009-01-01

    As the main structural protein of oil body, OLEOSIN is highly expressed only during seed development. OLEOSIN promoter is a very useful tool for seed-specific gene engineering and seed bioreactor designing. The B3 domain transcription factor leafy cotyledon2 (LEC2) plays an important role in regulating seed development and seed-specific gene expression. Here, we first report how seed-specific B3 domain transcription factor leafy cotyledon2 (LEC2) efficiently activates OLEOSIN expression. The central promoter region of OLEOSIN, responsible for seed specificity and LEC2 activation, was determined by 5'-deletion analysis. Binding experiments in yeast cells and electrophoretic mobility shift assays showed that LEC2 specifically bound to two conserved RY elements in this region, in transient expression assays, mutation in either RY element dramatically reduced LEC2 activation of OLEOSIN promoter activity, while double mutation abolished it. Analysis of the distribution of RY elements in seed-specific genes activated by LEC2 also supported the idea that genes containing neighboring RY elements responded strongly to LEC2 activation. Therefore, we conclude that two neighboring RY elements are essential for efficient LEC2 activation of OLEOSIN expression. These findings will help us better utilize seed-specific promoter activity.

  11. Which Neuronal Elements are Activated Directly by Spinal Cord Stimulation.

    Holsheimer, Jan

    2002-01-01

    The purpose of this paper is to discuss which nerve fibers in the various quadrants of the spinal cord are immediately activated under normal conditions of spinal cord stimulation, ie, at voltages within the therapeutic range. The conclusions are based on both empirical and computer modeling data. The recruitment of dorsal column (DC) fibers is most likely restricted to Aβ fibers with a diameter ≥ 10.7 μm in a 0.20-0.25 mm layer under the pia mater and fibers of 9.4-10.7 μm in an even smaller outer layer when a conventional SCS lead is used. In a 0.25-mm outer layer of the T11 segment the number of Aβ fibers ≥ 10.7 μm, as estimated in a recent morphometric study, is about 56 in each DC. Because a DC at T11 innervates 12 dermatomes, a maximum of 4-5 fibers (≥ 10.7 μm) may be recruited in each dermatome near the discomfort threshold. The dermatome activated just below the discomfort threshold is likely to be stimulated by just a single fiber, suggesting that paresthesia and pain relief may be effected in a dermatome by the stimulation of a single large Aβ fiber. The depth of stimulation in the DCs, and thereby the number of recruited Aβ fibers, may be increased 2-3 fold when stimulation is applied by an optimized electrode configuration (a narrow bi/tripole or a transverse tripole). Assuming that the largest Aβ fibers in a dorsal root have a diameter of 15 μm, the smallest ones recruited at discomfort threshold would be 12 μm. The latter are presumably of proprioceptive origin and responsible for segmental reflexes and uncomfortable sensations. Furthermore, it is shown to be unlikely that, apart from dorsal roots and a thin outer layer of the DCs, any other spinal structures are recruited when stimulation is applied in the dorsal epidural space. Finally, anodal excitation and anodal propagation block are unlikely to occur with SCS. PMID:22151778

  12. Activation analysis of toxic elements in meat and farinaceous foodstuffs of the Republic of Argentina

    As a result of the industrial and agrochemical developments, there has been an increase of the environmental pollution. Foodstuffs are one of the ways of incorporating some heavy metals or other contaminants into the human body. So, it is important to know the amount of these elements in the food consumed by the population. Our project on determination of toxic elements in meat and farinaceous food largely consumed in our country, was carried out by neutron activation analysis. Different kinds of flours and noodles were analyzed as farinaceous, and hamburgers and sausages as manufactured meat products. Specific separation methods were developed by radiochemical neutron activation analysis for As, Sb, Se, Hg and Cd. All these separations were based on precipitation or coprecipitation of the elements as sulphides. Other elements such as Fe, Br, Co, Zn, Rb, and also Se, were analyzed using instrumental neutron activation analysis. Using daily intake of analyzed foodstuffs from consumption tables and their average elemental composition, an intake of the studied elements was calculated. The values obtained for toxic elements were lower than the maximum permissible levels in Argentina. The results of this project could serve as a basis of a wider study including more foodstuffs as raw meat and will be used by other research groups. (author). 8 refs, 3 figs, 4 tabs

  13. A single heterochromatin boundary element imposes position-independent antisilencing activity in Saccharomyces cerevisiae minichromosomes.

    Sangita A Chakraborty

    Full Text Available Chromatin boundary elements serve as cis-acting regulatory DNA signals required to protect genes from the effects of the neighboring heterochromatin. In the yeast genome, boundary elements act by establishing barriers for heterochromatin spreading and are sufficient to protect a reporter gene from transcriptional silencing when inserted between the silencer and the reporter gene. Here we dissected functional topography of silencers and boundary elements within circular minichromosomes in Saccharomyces cerevisiae. We found that both HML-E and HML-I silencers can efficiently repress the URA3 reporter on a multi-copy yeast minichromosome and we further showed that two distinct heterochromatin boundary elements STAR and TEF2-UASrpg are able to limit the heterochromatin spreading in circular minichromosomes. In surprising contrast to what had been observed in the yeast genome, we found that in minichromosomes the heterochromatin boundary elements inhibit silencing of the reporter gene even when just one boundary element is positioned at the distal end of the URA3 reporter or upstream of the silencer elements. Thus the STAR and TEF2-UASrpg boundary elements inhibit chromatin silencing through an antisilencing activity independently of their position or orientation in S. cerevisiae minichromosomes rather than by creating a position-specific barrier as seen in the genome. We propose that the circular DNA topology facilitates interactions between the boundary and silencing elements in the minichromosomes.

  14. Determination of rare earth elements in zircons by neutron activation analysis and their geochemical significance

    The concentrations of rare earth elements (REE) have been determined in zircon samples from different geological environments by radiochemical neutron activation analysis (RNAA) procedure, which is described. Prior to the REE determination, the uranium content of the zircon is obtained by the delayed neutron activation analysis technique (DNAA). In the determination of light rare earth elements from the activity of (n,γ) products, corrections were applied for the contributions from fission products nuclide (which are identical with the (n,γ) products). The REE patterns thus obtained seem to be characteristic of the evolution of their parent magma and could be used to trace their petrogenetic history. (author)

  15. Multi-element study of Rutile sands using the Non Destructive Technique of Neutron Activation Analysis

    The objective of the method is to analyze qualitative and quantitative elements Ti, Al, Cr, Fe, and Zr in Rutile sands. By this analytical technique, the sample does not require a previous preparation and is then irradiated with a thermal neutron flux in the TRIGA-1 Salazar Reactor. The sample is then counted in a gamma spectrometer fitted with a High-purity detector which make possible the simultaneous determination of the elements in the qualitative and quantitative forms. The elements analyzed in Rutile sands were Ti, Mn, Al, Hf, Dy, Au, W, La, Eu, Ca, Cr, Sc, No and Fe. Nuclear Activation Analysis is a wide used technique for the analysis of trace elements in pure materials or with several major elements. (Author)

  16. Trace elements determination in Algerian wheat by instrumental neutron activation analysis (INAA)

    In Algeria, bread is the staple food, produced in different kinds from local and imported wheat. Most of it is not subjected to micro-elemental analysis. The objective of this study is to determine quantitatively the traces elements in samples wheat grains produced locally from different cultivated provinces in Algeria. Trace elements (Co, Cr, Cs, Fe, Rb, Sc, Se and Zr) were determined using neutron activation analysis. The results show that the contents of the traces elements in the studied samples were within the safety baseline of all the assayed elements recommended by WHO/FAO except for cobalt in El Harrach province. The analytical results showed that chromium was undetectable in all samples except for Constantine, Ain Mlila and Setif provinces. However zirconium content in a few samples exceeded the permissible level. (author)

  17. Data intercomparison and determination of toxic and trace elements in algae using instrumental neutron activation analysis

    For the non-destructive multi-elemental analysis of environmental and biological materials, instrumental neutron activation analysis (INAA) was applied for the determination of toxic and trace elements in a set of three Algae samples provided by the international Atomic Energy (IAEA). The analytical quality control was evaluated by comparing the analytical results of two standard reference materials of the National Institute of Standards and Technology (NIST); Oyster Tissue (SRM 1566a) and Citrus Leaves (SRM 1572). According to given analytical procedure, the concentration of 15-25 elements including spiked elements such As, Cd, Cr and Hg in Algae samples were determined. To identify and validate these results, a data intercomparison program using more than 35 analytical methods in 150 laboratories was carried out and the estimated statistical data are summarized. Result of INAA is favorable, therefore, it is illustrated that can be applied for routine analysis of essential and toxic elements in algae samples as well as analytical quality assurance

  18. Multi-elemental profile of some Brazilian make-up products by instrumental neutron activation analysis

    Dalmazio, Ilza; Menezes, Maria Angela de B.C., E-mail: id@cdtn.b, E-mail: menezes@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Servico de Reator e Tecnicas Analiticas. Lab. de Ativacao Neutronica

    2011-07-01

    Recent works have shown that analysis in cosmetics and beauty products from the European and Asian markets indicate the presence of U, Th and rare earths besides other trace elements. Considering these previous findings and health issues, it would be valuable to obtain information on elements in cosmetics available in the Brazilian market. The purpose of this study was to acquire a multi-elemental profile of some Brazilian make-up products of diverse brands. Samples of eye shadow, liquid base, facial concealer, lipstick, and compact face powder were analyzed applying neutron activation analysis, k{sub 0}-standardization method at CDTN/CNEN, using the TRIGA Mark I IPR-R1 research reactor. Concentrations of more than 30 elements in samples are presented and it was found elements included in Brazilian National Health Surveillance Agency prohibitive list, rare earths, Th and U in a minimum of two cosmetic samples. (author)

  19. Multi-elemental profile of some Brazilian make-up products by instrumental neutron activation analysis

    Recent works have shown that analysis in cosmetics and beauty products from the European and Asian markets indicate the presence of U, Th and rare earths besides other trace elements. Considering these previous findings and health issues, it would be valuable to obtain information on elements in cosmetics available in the Brazilian market. The purpose of this study was to acquire a multi-elemental profile of some Brazilian make-up products of diverse brands. Samples of eye shadow, liquid base, facial concealer, lipstick, and compact face powder were analyzed applying neutron activation analysis, k0-standardization method at CDTN/CNEN, using the TRIGA Mark I IPR-R1 research reactor. Concentrations of more than 30 elements in samples are presented and it was found elements included in Brazilian National Health Surveillance Agency prohibitive list, rare earths, Th and U in a minimum of two cosmetic samples. (author)

  20. Trace element determination in beauty products by k0-instrumental neutron activation analysis

    A recent study on trace elements in beauty products and cosmetics sold on the Asian market has shown the presence of high levels of U, Th and rare earth elements in so called 'Hormesis cosmetics'. For the purpose of comparison, some more information about trace elements in European cosmetics would be useful. In this paper the results obtained using k0-standardised Instrumental Neutron Activation Analysis (k0-INAA) for more than 20 trace elements in 20 different beauty products collected from the European market are presented. We found traces of Ba, As and Sb which is in breach with European legislation. For some of the other elements like Cr and Co further speciation is needed in order to evaluate their presence in beauty products. (author)

  1. Radiochemical neutron activation analysis for trace elements evaluation of human milk

    The principal objective pursued in this study is to establish the base-line data on the status of elemental composition in human milk from Pakistani subjects of Rawalpindi/Islamabad area. Radiochemical neutron activation analysis (RNAA) methodology was developed and successfully employed to determine the concentration of 18 minor and trace elements (essential, toxic and nonessential) in human milk. This methodology has significantly improved the detection limits of most of these elements due to suppression of Compton background. The data provide the base-line values of these elements in human milk of low- and medium-income group subjects of the region. The results obtained show good compatibility with the data reported by the WHO on elemental composition of human milk from different geological regions. (orig.)

  2. Determination of trace elements in BCR single cell protein via destructive neutron activation analyses

    The amount of some trace elements in single cell protein (SCP), a product of BP Research Centre at Sunbury-at-Thames, England, was determined by neutron activation analysis. The SCP-samples were irradiated in the reactor of the Interuniversity Reactor Institute at Delft in a neutron flux of 1.0x1013 n/cm2s for 12 hours. Samples of Bowen's Kale were used as reference material. After a decay of two or three days the samples were chemically destroyed, and the trace elements were separated. The quantity of the following elements was determined by measuring the γ-activity by means of a scintillation counter: antimony, cadmium, mercury, arsenic and selenium. The amounts of these elements in the SCP and in the reference material were tabled

  3. Elemental Composition, Anticariogenic, Pancreatic Lipase Inhibitory and Cytotoxic Activity of Artocarpus Lakoocha Roxb Pericarp

    Prashith Kekuda TR

    2012-03-01

    Full Text Available Artocarpus lakoocha Roxb is belongs to the family Moraceae and is called Monkey jack and Lakoocha. In the present study, we investigated elemental composition of fruit pericarp and anticariogenic, pancreatic lipase inhibitory and cytotoxic activity of methanol extract of pericarp. The elemental analysis was determined using atomic absorption spectrophotometer. Anticariogenic activity was determined against 12 isolates of mutans streptococci by Agar well diffusion method. Pancreatic lipase activity of different concentrations of pericarp extract was tested against chicken pancreatic lipase. Cytotoxic activity was tested by Brine shrimp lethality bioassay. Among the principal elements, potassium was present in high concentration followed by magnesium, phosphorus and calcium. Among trace elements, high concentration of iron was detected followed by zinc, manganese and copper. The extract caused inhibition of cariogenic bacteria and the inhibition caused by the extract was lesser when compared to standard antibiotic. The extract caused inhibition of pancreatic lipase in a dose dependent manner and highest inhibition (82.49% was observed at concentration 1000mg/ml. The lethal nature of extract towards brine shrimp was directly proportional to the concentration of the extract. The LC50 was found to be 452.49μg/ml. Preliminary phytochemical analysis showed the presence of tannins and alkaloids. The fruit may be consumed as a source of important elements. The bioactivities of the extract could be attributed to the presence of secondary metabolites. Further study is required to isolate and characterize the active constituents and to determine their bioactivities.

  4. Application of activation analysis for determination of some elements in cassiterite samples

    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 H2SO4-HBr medium, after fusion of the ore with Na2O2. 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)

  5. Application of neutron activation analysis to the monitoring of trace elements in Brazilian foodstuffs

    Due to lack of data on trace element levels in Brazilian foodstuffs, nuclear analytical techniques were used to determine about twenty elements in foods samples collected from local markets of the city of Sao Paulo. Drinking water was also analyzed. The methods employed were mainly instrumental and radiochemical neutron activation analysis. In the case of the analysis of toxic elements, such as mercury, selenium, arsenic and antimony, the purely instrumental approach failed in yielding results for very low concentrations of these elements. For INAA, samples and multielemental synthetic standards were irradiated in the IEA R1 research reactor for periods of time ranging from minutes to several hours, under thermal neutron fluxes from 1011 to 1013 n·cm-2·s-1; after suitable cooling times, γ-ray spectra were measured using a Ge(Li) or Ge solid state detector. The RNAA approach involved the distillation of mercury and selenium in HBr medium; selenium was then reduced to the metal form with sodium metabisulphide and mercury was precipitated as sulphide with thioacetamide. For water analysis, a preconcentration procedure based on retention of several elements in a Chelex-100 resin was employed. The elements retained were Hg, Cr, Zn, Fe, Co while Se was measured in the effluent after absorption on active charcoal. The levels of the trace inorganic elements determined in the Brazilian foodstuffs analyzed were always below the levels established by the existing regulations in our country. (author). 16 refs, 18 tabs

  6. Identification and Determination of Trace Elements in Rice Seeds by Neutron Activation Analysis

    In rice seeds, the high activities of 42K, 38Cl and other radioisotopes induced by neutron irradiation make it impossible to identify most of the trace elements directly by gamma-ray spectrometry. To overcome this difficulty, fast and selective radiochemical group-separation methods have been developed which allow the identification of various trace elements such as Ba, Sr, As, Sb, Fe, Cu, Zn and Cd. Neutron activation analysis has also been used to determine six elements existing in quantities of the order of milligrams or traces. In these cases, after the addition of appropriate carrier elements, the radioisotopes were separated individually by standard radiochemical procedures, and chemical yields were determined. The experimental procedures are described. Amongst the seeds analysed, four varieties, Spanish and Korean, were included that were selected by the Institutes of Agricultural Research of Spain and Korea, and were of known origin. Wide differences in trace-element concentrations were observed. Measurements on whole seeds and seeds without cortex showed that the trace element contents of the former are two or three times those of the latter. This suggests an enrichment of trace elements in the seed cortex. The concentration ranges observed were: 6 to 50 ppm for Mn, 1 to 4 ppm for Cu, 7 to 45 ppm for Na, 0.2 to 1 ppm for Br, 1000 to 4800 ppm for K and 200 to 2500 ppm for CI. (author)

  7. Determination of trace elements in tobacco using different techniques of neutron activation analysis

    Quantitative data on trace elements in two tobacco leaf (candidate) reference materials OTL-1 and VTL-2 prepared by the Polish Academy of Sciences and the Institute of Nuclear Chemistry and Technology, Warsaw, Poland, are presented and compared to recommended values, where available. By instrumental neutron activation analysis (INAA), as well as by radiochemical technique (RNAA) 30 elements were quantitatively determined and fair agreement was found between the results and recommended values for the first material. (author) 18 refs.; 5 tabs

  8. Studies of nutritionally and toxicologically important elements in foods and diets by neutron activation

    Several neutron activation analysis (NAA) methods in conjunction with conventional and anticoincidence counting have been developed in our laboratory over the years for the quantitative determination of up to 24 elements in foods and diets. Additionally, these methods have been applied to measure bioaccessible, ionic, proteomic, lipidic, and organometallic species of many elements. The overall expanded uncertainties of the methods have also been evaluated. (author)

  9. Trace Elements Affect Methanogenic Activity and Diversity in Enrichments from Subsurface Coal Bed Produced Water

    Ünal, Burcu; Perry, Verlin Ryan; Sheth, Mili; Gomez-Alvarez, Vicente; Chin, Kuk-Jeong; Nüsslein, Klaus

    2012-01-01

    Microbial methane from coal beds accounts for a significant and growing percentage of natural gas worldwide. Our knowledge of physical and geochemical factors regulating methanogenesis is still in its infancy. We hypothesized that in these closed systems, trace elements (as micronutrients) are a limiting factor for methanogenic growth and activity. Trace elements are essential components of enzymes or cofactors of metabolic pathways associated with methanogenesis. This study examined the effe...

  10. Trace elements affect methanogenic activity and diversity in enrichments from subsurface coal bed produced water

    KlausNüsslein; BurcuÜnal

    2012-01-01

    Microbial methane from coal beds accounts for a significant and growing percentage of natural gas worldwide. Our knowledge of physical and geochemical factors regulating methanogenesis is still in its infancy. We hypothesized that in these closed systems, trace elements (as micronutrients) are a limiting factor for methanogenic growth and activity. Trace elements are essential components of enzymes or cofactors of metabolic pathways associated with methanogenesis. This study examined the effe...

  11. Neutron activation analysis as applied to instrumental analysis of trace elements from seawater

    Particulate matter collected from the coastal area delimited by the mouth of the river Volturno and the Sabaudia lake has been analyzed by instrumental neutron activation analysis for its content of twenty-two trace elements. The results for surface water and bottom water are reported separately, thus evidencing the effect of sampling depth on the concentration of many elements. The necessity of accurately 'cleaning' the filters before use is stressed

  12. Application of neutron activation analysis to the determination of toxic elements in Malaysia foodstuffs

    The main activities for last year were on the analysis of toxic elements in vegetables, milk and poultry samples. At the same time works on the radiochemical separation were conducted as most of these samples contain less amount of toxic elements of interest. The separation technique for As was established i.e. precipitation method. This method apparently gives a good recovery. As for Sb, Se and Hg we are still studying the best separation techniques. 5 tabs

  13. Determination of Inorganic Elements in White Rice by Neutron Activation Analysis

    Moon, J. H.; Kim, S. H.; Lim, J. M.; Lee, Y. N.; Chung, Y. S. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2011-05-15

    Rice is a staple food and provides an important information of mineral supplement as well as a large portion of calorie for Korean. As scientists have focused their researches on health impacts caused by mineral nutrient deficiency and hazardous elements, public concerns about mineral intake by dietary food is rising. The objectives of this study were to determine inorganic elemental contents in white rice by neutron activation analysis(NAA) and to assist the evaluation of nutritional and harmful status for Korean people

  14. Elemental concentration determination in certain medicinal leaves by K0 instrumental neutron activation analysis

    Elemental concentrations of two types of medicinal leaves (neem and eucalyptus) are determined by neutron activation analysis using single comparator (K0 NAA) method. Data obtained on one of the varieties studied (neem), collected from two different places, have also been used to see the effect of soil condition. The method was validated by analysing the SRM-1571 and it was found that the measured elemental concentrations in SRM-1571 are within ±9% of the reported values. (author)

  15. Multi-element analysis of emeralds and associated rocks by k(o) neutron activation analysis

    Acharya; Mondal; Burte; Nair; Reddy; Reddy; Reddy; Manohar

    2000-12-01

    Multi-element analysis was carried out in natural emeralds, their associated rocks and one sample of beryl obtained from Rajasthan, India. The concentrations of 21 elements were assayed by Instrumental Neutron Activation Analysis using the k0 method (k0 INAA method) and high-resolution gamma ray spectrometry. The data reveal the segregation of some elements from associated (trapped and host) rocks to the mineral beryl forming the gemstones. A reference rock standard of the US Geological Survey (USGS BCR-1) was also analysed as a control of the method. PMID:11077961

  16. Concentration of 17 Elements in Subcellular Fractions of Beef Heart Tissue Determined by Neutron Activation Analysis

    Subcellular fractions of beef heart tissue are investigated, by means of neutron activation analysis, with respect to their concentration of 17 different elements. A recently developed ion-exchange technique combined with gamma spectrometry is used. The homogeneity of the subcellular fractions is examined electron microscopically. The following elements are determined: As, Ba, Br, Cas Co, Cs, Cu, Fe, Hg, La, Mo, P, Rb, Se, Sm, W and Zn. The determination of Ag, Au, Cd, Ce, Cr, Sb and Sc is omitted, in view of contamination. Reproducible and characteristic patterns of distribution are obtained for all elements studied

  17. Finite element crash simulations of the human body: Passive and active muscle modelling

    S Mukherjee; A Chawla; B Karthikeyan; A Soni

    2007-08-01

    Conventional dummy based testing procedures suffer from known limitations. This report addresses issues in finite element human body models in evaluating pedestrian and occupant crash safety measures. A review of material properties of soft tissues and characterization methods show a scarcity of material properties for characterizing soft tissues in dynamic loading. Experiments imparting impacts to tissues and subsequent inverse finite element mapping to extract material properties are described. The effect of muscle activation due to voluntary and non-voluntary reflexes on injuries has been investigated through finite element modelling.

  18. Toenail elemental analysis of Korean young adults by instrumental neutron activation analysis

    The element contents in toenail clippings of healthy Korean young adults were measured using an instrumental neutron activation analysis. The average contents of elements such as Na, K, Cl, Ca, Fe, Se, and Zn are 449, 474, 1024, 1677, 66, 0.7 and 94 mg/kg in men, whereas those contents in women respectively 332, 476, 836, 1097, 66, 0.8 and 104 mg/kg. The correlation analysis of toenail elements with chronic disease risks showed positive associations between Na and serum HDL-cholesterol, blood pressure, and negative associations between Se and Hs-CRP, between Zn and hemoglobin level. (author)

  19. Elemental analysis of soil and hair sample by instrumental neutron activation analysis

    Chung, Yong Sam; Quraishi, Shamshad Begum; Moon, Jong Hwa; Kim, Sun Ha; Baek, Sung Yeoil; Kang, Sang Hoon; Lim, Jong Myoung; Cho, Hyun Je; Kim, Young Jin

    2004-03-01

    Myanmar soil sample was analyzed by using the instrumental neutron activation analysis. The elemental concentrations in the sample, altogether 34 elements, Al As, Ba, Ce, Co, Cr, Cs, Eu, Fe, Ga, Gd, Hf, Ir, K, La, Lu, Mn, Na, Nd, Rb, Sb, Sc, Se, Sm, Th, Ti, V, Yb, Zn and Zr were determined. The concentration of 17 elements (Al, Au, Br, Ca, Cl, Cr, Cu, Co, Fe, Hg, K, Na, Mn, Mg, Sb, Se, Zn) in human hair samples were determined by INAA For quality control of analytical method, certified reference material was used.

  20. Elemental analysis of soil and hair sample by instrumental neutron activation analysis

    Myanmar soil sample was analyzed by using the instrumental neutron activation analysis. The elemental concentrations in the sample, altogether 34 elements, Al As, Ba, Ce, Co, Cr, Cs, Eu, Fe, Ga, Gd, Hf, Ir, K, La, Lu, Mn, Na, Nd, Rb, Sb, Sc, Se, Sm, Th, Ti, V, Yb, Zn and Zr were determined. The concentration of 17 elements (Al, Au, Br, Ca, Cl, Cr, Cu, Co, Fe, Hg, K, Na, Mn, Mg, Sb, Se, Zn) in human hair samples were determined by INAA For quality control of analytical method, certified reference material was used

  1. Study on trace element determination in human head hair using neutron activation analysis

    Trace element determination in human hair has become increasingly popular for monitoring environmental exposure, assessing nutritional status, evaluating intoxication and diagnosing diseases. However, there are controversies of this use due to the difficulty in the removal of only exogenous origin elements from the hair, the small correlation data between elements contents in the hair and other tissues and the poor quality of analytical results for certain elements. In this study, adequate experimental conditions have been established for human scalp hair analysis in order to obtain further reliable reference value ranges. Neutron activation analysis (NAA) was used for the determination of fourteen trace elements. Irradiations were performed at the IEA-R1 nuclear research reactor. Aliquots of samples from three individuals were analyzed and the results presented good reproducibility, indicating the sample homogeneity. The quality control of the results was assessed analyzing certified materials. The relative errors lower than 8% and relative standard deviations varying from 1.2 to 15% were obtained for most of elements in the reference materials analysis. Hair samples from voluntary donors from Sao Paulo State, aged from 15 to 60 years were studied and the results obtained indicate that As, Co, Cr, Cs, La, Sb, Sc and Se are present in the hair at a low level of 7g kg-1 and the elements Br, Ca, Fe, K, Na and Zn, at μg kg-1 level. There is a necessity of obtaining reliable reference values or intervals for hair trace elements for a defined healthy population. (author)

  2. Identification of three kinds of mutually related composite elements conferring S phase-specific transcriptional activation.

    Taoka, K; Kaya, H; Nakayama, T; Araki, T; Meshi, T; Iwabuchi, M

    1999-06-01

    Conservation of the Oct motif (CGCGGATC) is a remarkable feature of plant histone gene promoters. Many of the Oct motifs are paired with a distinct motif, Hex, TCA or CCAAT-box, constituting the type I element (CCACGTCANCGATCCGCG), type II element (TCACGCGGATC) and type III element (GATCCGCG-N14-ACCAATCA). To clarify the roles of these Oct-containing composite elements (OCEs) in cell cycle-dependent and tissue-specific expression, we performed gain-of-function experiments with transgenic tobacco cell lines and plants harboring a derivative of the 35S core promoter/beta-glucuronidase fusion gene in which three or four copies of an OCE had been placed upstream. Although their activities were slightly different, results showed that each of the three types of OCEs could confer the ability to direct S phase-specific expression on a heterologous promoter. In transgenic plants, the type I and III elements exhibited a similar activity, directing expression in meristematic tissues, whereas the activity of the type II element appeared to be restricted to young cotyledons and maturating guard cells. Mutational analyses demonstrated that the co-operation of Oct with another module (Hex, TCA or CCAAT-box) was absolutely required for both temporal and spatial regulation. Thus, OCEs play a pivotal role in regulation of the expression of plant histone genes. PMID:10417712

  3. Determination of Interesting Toxicological Elements in PM2.5 by Neutron and Photon Activation Analysis

    Pasquale Avino

    2013-01-01

    Full Text Available Human activities introduce compounds increasing levels of many dangerous species for environment and population. In this way, trace elements in airborne particulate have a preeminent position due to toxic element presence affecting the biological systems. The main problem is the analytical determination of such species at ultratrace levels: a very specific methodology is necessary with regard to the accuracy and precision and contamination problems. Instrumental Neutron Activation Analysis and Instrumental Photon Activation Analysis assure these requirements. A retrospective element analysis in airborne particulate collected in the last 4 decades has been carried out for studying their trend. The samples were collected in urban location in order to determine only effects due to global aerosol circulation; semiannual samples have been used to characterize the summer/winter behavior of natural and artificial origin. The levels of natural origin element are higher than those in other countries owing to geological and meteorological factors peculiar to Central Italy. The levels of artificial elements are sometimes less than those in other countries, suggesting a less polluted general situation for Central Italy. However, for a few elements (e.g., Pb the levels measured are only slight lower than those proposed as air ambient standard.

  4. Trace Element Analysis of Human Lung Tissue by Neutron Activation and Instrumental Analysis

    The measurement of trace elements in tissues in the ppm to pp109 range requires very careful and specialized techniques both in the sample acquisition and in subsequent analysis. Many of the trace elements which are present in human tissues are at lower concentrations than those in super-pure chemical reagents; also, an acid rinse of typical laboratory glassware may contain as much of some trace elements as the tissue sample being studied. An analytical technique based on neutron activation for the measurement of trace elements in tissues has been developed which requires a minimum of pre-irradiation handling followed by the direct measurement of the activation products on a multidimensional or a solid-state gammaray spectrometer. This technique has been applied to a study of trace elements in human lung tissue. Lung tissue contains not only the tissue-bound elements but also those which have been deposited in the cells of the pulmonary alveoli through inhalation. The method permits the direct measurement of 15 trace elements. The analysis of lung tissues thus provides information on the integrated trace element deposition resulting during the life of an individual. The concentrations of several of these including Fe, Br, P, Se, Ag, Zn, Cs, Co, Sc, U and Sb have been measured in several autopsy and biopsy samples of both normal and diseased tissues from several subjects with known case histories. The variations in the observed trace element compositions are presented and considered in terms of the occupational and medical history of the subject. (author)

  5. Multi-element characterization of silicon nitride powders by instrumental and radiochemical neutron activation analysis

    Franek, M.; Krivan, V. (Ulm Univ. (Germany). Sektion Analytik und Hoechstreinigung)

    1992-07-15

    An optimized instrumental neutron activation analysis method was applied to the comprehensive trace characterization of good- and high- purity silicon nitride powders of different origins. Experimental modes are given for 55 elements leading to limits of detection below 1 ng g[sup -] [sup 1] for 28 elements, between 1 and 100 ng g[sup -1] for 19 elements and higher than 100 ng g[sup -1] for 8 elements. For the removal of the radionuclides [sup 140]La, [sup 182]Ta and [sup 187]W, which cause the major activity in certain types of materials, radiochemical procedures based in cation exchange from 2 M HCl and anion exchange from 2 M HF were developed. [sup 64]Cu was selectively extracted with dithizone from 10 M HF for counting the 511-keV line. By radiochemical neutron activation analysis, the limits of detection were improved by up to three orders of magnitude. Comparison with results obtained by inductively coupled plasma (ICP) atomic emission spectrometry and ICP mass spectrometry shows satisfactory agreement and demonstrates the advantages of neutron activation analysis especially when low elements contents are to be determined. (author). 30 refs.; 2 figs.; 6 tabs.

  6. Study on the activated laser welding of ferritic stainless steel with rare earth elements yttrium

    Wang, Yonghui; Hu, Shengsun; Shen, Junqi

    2015-10-01

    The ferritic stainless steel SUS430 was used in this work. Based on a multi-component activating flux, composed of 50% ZrO2, 12.09 % CaCO3, 10.43 % CaO, and 27.49 % MgO, a series of modified activating fluxes with 0.5%, 1%, 2%, 5%, 10%, 15%, and 20% of rare earth (RE) element yttrium (Y) respectively were produced, and their effects on the weld penetration (WP) and corrosion resistant (CR) property were studied. Results showed that RE element Y hardly had any effects on increasing the WP. In the FeCl3 spot corrosion experiment, the corrosion rates of almost all the samples cut from welded joints turned out to be greater than the parent metal (23.51 g/m2 h). However, there was an exception that the corrosion rate of the sample with 5% Y was only 21.96 g/m2 h, which was even better than parent metal. The further Energy Dispersive Spectrometer (EDS) test showed the existence of elements Zr, Ca, O, and Y in the molten slag near the weld seam while none of them were found in the weld metal, indicating the direct transition of element from activating fluxes to the welding seam did not exist. It was known that certain composition of activating fluxes effectively restrain the loss of Cr element in the process of laser welding, and as a result, the CR of welded joints was improved.

  7. Trace elements affect methanogenic activity and diversity in enrichments from subsurface coal bed produced water

    KlausNüsslein

    2012-05-01

    Full Text Available Microbial methane from coal beds accounts for a significant and growing percentage of natural gas worldwide. Our knowledge of physical and geochemical factors regulating methanogenesis is still in its infancy. We hypothesized that in these closed systems, trace elements (as micronutrients are a limiting factor for methanogenic growth and activity. Trace elements are essential components of enzymes or cofactors of metabolic pathways associated with methanogenesis. This study examined the effects of eight trace elements (iron, nickel, cobalt, molybdenum, zinc, manganese, boron, and copper on methane production, on mcrA transcript levels, and on methanogenic community structure in enrichment cultures obtained from coal bed methane well produced water samples from the Powder River Basin, Wyoming. Methane production was shown to be limited both by a lack of additional trace elements as well as by the addition of an overly concentrated trace element mixture. Addition of trace elements at concentrations optimized for standard media enhanced methane production by 37%. After seven days of incubation, the levels of mcrA transcripts in enrichment cultures with trace element amendment were much higher than in cultures without amendment. Transcript levels of mcrA correlated positively with elevated rates of methane production in supplemented enrichments (R2=0.95. Metabolically-active methanogens, identified by clone sequences of mcrA mRNA retrieved from enrichment cultures, were closely related to Methanobacterium subterraneum and Methanobacterium formicicum. Enrichment cultures were dominated by M. subterraneum and had slightly higher predicted methanogenic richness, but less diversity than enrichment cultures without amendments. These results suggest that varying concentrations of trace elements in produced water from different subsurface coal wells may cause changing levels of coal bed methane production and alter the composition of the active

  8. Determination of trace elements in lichen samples by instrumental neutron activation analysis

    Samples of Canoparmelia texana lichen collected in different sites of Sao Paulo and Parana States, Brazil, were analysed by neutron activation analysis in order to obtain preliminary information on the air quality in these regions and also to select a region of interest for biomonitoring studies. Also Tadescantia pallida plant has been analysed in order to study the viability of using this specimen in environmental pollution monitoring. Lichens samples were collected from tree barks which were also collected to investigate the contribution of substrate derived elements to elements present in lichens. Young and old leaves of T. pallida were collected separately in order to study the leaf age effects on their elemental levels. The samples were cleaned, washed with distilled water, dried and ground for the analyses. Samples and standards were irradiated at the IEA-Rlm nuclear reactor for short and long periods and concentrations of the elements Al, As, Ca, Cd, Cl, Co, Cr, Cs, Fe, Hf, Mg, Mn, Rb, Sb, Sc, D, Th, U, V Zn and lanthanides were determined. Preliminary results obtained for T. texana lichen indicated that three sites (Ibiuna, Botanical Garden and Parque de Vila Velha) present low concentrations of the most elements analysed. Therefore lichens from these regions could be analysed to establish baseline levels of elements for monitoring purposes. Samples collected in open areas presented high concentrations of some elements probably due to the accumulation of elements originating from soil and from heavy vehicular traffic. Elemental concentrations obtained in outer barks were similar or smaller than those results obtained for lichens. Results obtained for T. pallida indicated that concentrations of elements in old leaves of this plant are of the same magnitude or slightly higher than those presented in young ones. (author)

  9. A method of neutron activation analysis to determine the concentration of alloy elements in steels

    The determination of the concentration of V, Mn and W in several types of steels was carried out through neutron activation analysis with an isotopic neutron source. Induced activities were detected with a NaI(Tl) gamma spectrometer coupled to a single channel pulse height analyser. Highly significant correlations have been found between specific count rates for each radionuclide and the concentration of the corresponding element (r > = .999 for each element); concentration ranges comprised a number of steel types. The comparison between the results of the application of the method and the ones obtained through conventional chemical analyses showed discrepancies no higher than 10%. (Author)

  10. Neutron activation analysis of rare earths and some other elements in material of geochemical interest

    ngle-element methods for the determination by neutron activation analysis of antimony, chromium, phosphorus, selenium and silver in international geochemical standard rocks, and the determination of rare earth elements i in standard rocks and apatites are described and discussed in twelve previously published papers, and in an eighteen page summary. Chemical separationtechniques are also discussed and the results are compared with previously obtained results with the same standard rocks. The accuracy of neutron activation analysis is discussed in comparison with isotope dilution mass spectroscopy, atomic absorption, gas chromatography and spark source mass spectrometry. (JIW)

  11. The Determination Of Trace Element Levels In Diet By Neutron Activation Analysis

    Trace element levels in foodstuff are normally low. Although the levels are low, certain trace elements which are called essential trace elements have an important role in metabolism process. Deficiency or intoxication of essential trace elements may lead to abnormal health. In this study the levels of Zn, Fe, AI, Mn, and Co in diet samples were determined by neutron activation analysis, and then the daily intakes of these elements were estimated. The samples were prepared by duplicate diet method, representing those that were consumed by population from West, Central and East Java. Following the collection the respective samples were blended, then were freeze dried at-54oc. The elemental quantification were performed by neutron activation analysis. The traceability of the determination was ensured using standard reference material NIST-SRM-1548a. The results show that the daily intake for Zn were 2.8-22.8 mg/day (reference value were 5- 40 mg/day), Fe were 3.1-26.5 mg/day (reference value were 6-40 mg/day), AI were 4,2-32.9 mg/day (reference value were 2-45 mg/day), Mn were 1.0-5,6 mg/day (reference value were 0.4-10,0 mg/day), and Co were 0,005-0,074 mg/day (reference value were 0.005 -1.8 mg/day

  12. Utilisation of a low power reactor for instrumental neutron activation analysis of 40 elements in coal

    Coal is mostly used as an energy source for power generation and in local brick kilns in Pakistan, which causes environmental pollution problems due to the release of toxic constituents. Elemental characterisation provides useful information regarding the nature of environmental pollutants to which coal workers and adjacent terrain are exposed and circumscribes different elements as they exist in the coal. Instrumental neutron activation analysis employing a low power miniature neutron source reactor has been used for the determination of 40 major, minor, and trace elements in coal. Bituminous, sub-bituminous and lignite coal varieties of Pakistan were analysed which show that bituminous coal from Salt Range contains lower amount of toxic elements. The quality of the analysed data has been assured by a simultaneous analysis of the IAEA and NBS/NIST certified reference materials. The data will be useful for extrapolating the extent of elemental emission through the combustion of these coals. Enrichment factors calculated for these elements in coal show high values for As, Br, Cl, Dy, Hg, Mo, Sb, and Se, indicating difference in geochemistry and growth environment of the coal deposits. Elemental concentrations of our coal varieties have been compared with those of other countries. (orig.)

  13. Determination of elements in different parts of goat brain using k0 instrumental neutron activation analysis

    Researcher's interest is increasing worldwide to study the role of trace elements in brain tissues. This paper discusses the application of k0-instrumental neutron activation analysis to study the distribution of trace elements in seven different anatomical regions of goat brain. These regions include cerebellum, cerebrum, medulla oblongata, meninges, midbrain, pons and thalamus. The analysis protocol followed 1 h irradiation at 10 MW material testing type nuclear research reactor with nominal thermal neutron flux of 2 × 1013 cm-2 s-1. A total of 14 elements, namely Br, Co, Cr, Eu, Fe, Hg, K, Na, Rb, Sb, Sc, Se, Tb and Zn were determined in all parts. Reliability of the method was assessed by analyzing biological reference material IAEA-336 (lichen). On comparing the analytical results with the healthy human brain data, it showed that eight elements (Eu, K, Na, Rb, Sb, Sc, Se, Tb) were found with relatively higher elemental concentrations in human brain. Principal component analysis revealed distribution of seven parts in different three groups having similar elemental concentrations of elements. (author)

  14. Rare Earth Elements In Egyptian Granite By Instrumental Neutron Activation Analysis

    The mobilization of rare earth elements (REEs) in the environment requires monitoring of these elements in environmental matrices, in which they are mainly present at trace levels. The similarity in (REEs) chemical behavior makes the separate determination of each element by chemical methods difficult; instrumental neutron activation analysis (INAA), based on nuclear properties of the elements to be determined, is a method of choice in trace analysis of (REEs) and related elements. Therefore, (INAA) was applied as a sensitive nondestructive analytical tool for the determination of rare earth elements to find out what information could be obtained about the (REEs) of some Egyptian granite collected from four locations in Aswan area in south Egypt as follows wadi EI-Allaqi, EI-Shelal, Gabel Ibrahim Pacha and from Sehyel Island and to estimate the accuracy, reproducibility and detection limit of NAA method in case of the given samples. The samples were properly prepared together with standards and simultaneously irradiated in a neutron flux of 7 x 1011n/cm2.s in the TRIGA Mainz research reactor facilities. The following elements have been determined: La, Ce, Nd, Sm, Eu, Yb and Lu. The gamma spectra was collected by HPGe detector and the analysis was done by means of computerized multichannel analyzer. The X-ray fluorescence XRF was also used

  15. Studies of generalized elemental imbalances in neurological disease patients using INAA [instrumental neutron activation analysis

    Evidence has been presented in the literature to implicate trace elements in the etiology of several age-related neurological diseases. Most of these studies are based on brain analyses. Using instrumental neutron activation analysis (INAA), we have observed trace element imbalances in brains of patients with Alzheimer's disease, amyotrophic lateral sclerosis (ALS), and Picks's disease. The most prevalent elemental imbalances found in the brain were for bromine, mercury, and the alkali metals. In this study the authors report INAA studies of trace elements in nonneural tissues from Alzheimer's disease and ALS patients. Samples from household relatives were collected for use as controls wherever possible. Hair samples were washed according to the International Atomic Energy Agency recommended procedure. Fingernail samples were scraped with a quartz knife prior to washing by the same procedure. For ALS patients, blood samples were also collected. These data indicate that elemental imbalances in Alzheimer's disease and ALS are not restricted to the brain. Many elements perturbed in the brain are also altered in the several nonneural tissues examined to date. The imbalances in different tissues, however, are not always in the same direction. The changes observed may represent causes, effects, or simply epiphenomena. Longitudinal studies of nonneural tissues and blood, as well as tissue microprobe analyses at the cellular and subcellular level, will be required in order to better assess the role of trace elements in the etiology of these diseases

  16. Effects of Rare Earth Element Lan on the Activities of Earthworm Enzyme

    Xu Dongmei; Liu Wenli; Liu Weiping

    2007-01-01

    The effects of Rare Earth Element Lan on the activities of cellulose, catalase, peroxidase and superoxide dismutasein in earthworm were carried out by natural soil test. The results indicated that Lan can significantly suppress the activity of cellulose. The responses of three enzymes in earthworm to Lan were different, Lan mostly affects catalase activity and inhibited catalase activity throughout the experiment. Peroxidase activity tend to "promote weakly and inhibited strongly" when short term of exposure to Lan, while "inhibited weakly and promote strongly" as a function of time. In comparison, Lan had little influence on the activity of superoxide dismutase. The variance analysis results showed that the concentration of Lan significantly affected the activities of cellulose and CAT but had no obvious influence on the activities of SOD and POD. The treatment time and the interactive effect between treatment concentrations and time had very significant effect on the activities of cellulose, SOD, CAT and POD.

  17. Determination of elements in cisadane river sediments by neutron activation analysis

    Determination of elements in Cisadane river sediments by neutron activation analysis has been conducted. Samples of sediments were obtained from some location along Cisadane river, i.e. Leuranji, Karanggan, Cibigo, Cisauk, Warung Mangga Pintu Air and Estuary Teluk Naga. the elements analysed were Al, Mn, Mg, V, K, Na, Fe, Cr, Co, U and Zn, and the results were compared to the SRM of sediment sample from IAEA. Generally, the results showed that the mean concentration of elements were found in Cibogo, Cisauk, Pintu Air and Muara Teluk Naga which were higher than others. Concentration factor of elements in sediments were in between of 0,02 - 3,45, this factor indicated that Cisadane river sediments have not been contaminated. CRM sediments 2704 from IAEA used as NAA Quality Control (author)

  18. Neutron activation analysis of essential elements in Multani mitti clay using miniature neutron source reactor

    Multani mitti clay was studied for 19 essential and other elements. Four different radio-assay schemes were adopted for instrumental neutron activation analysis (INAA) using miniature neutron source reactor. The estimated weekly intakes of Cr and Fe are high for men, women, pregnant and lactating women and children while intake of Co is higher in adult categories and Mn by pregnant women. Comparison of MM clay with other type of clays shows that it is a good source of essential elements. - Highlights: ► Multani mitti clay has been studied for 19 essential elements for human adequacy and safety using INAA and AAS. ► Weekly intakes for different consumer categories have been calculated and compared with DRIs. ► Comparison of MM with other type of clays depict that MM clay is a good source of essential elements.

  19. Analysis of elements present in beers and brewing waters by neutron activation analysis

    Neutron activation analysis (NAA) was used for determination of Si, Na, K, Ca, Sc, V, Cr, Mn, Fe, Co, Zn, Rb, Cs, and La in Czech beers and brewing waters. The Si concentration in beer determined by the reaction 29Si(n,p)29Al with fast neutrons confirmed that beer is an important Si source in human diet. Determination of other trace elements by NAA with the whole spectrum of reactor neutrons aimed at the feasibility of identification of Gambrinus beers brewed in various breweries. The elements Ca and V appeared to be the best candidates for this purpose. The concentrations of elements determined by NAA were also compared with the recommended daily element intake for humans. The accuracy of the method was proved by analysis of reference materials, specifically NIST SRM 2704 Buffalo River Sediment, NIST SRM 1633b Coal Fly Ash, and NIST SRM 1515 Apple Leaves. (author)

  20. Determination of trace elements in Turkish tea leaves by instrumental neutron activation analysis

    The human body continuously assimilates a variety of inorganic elements from food and the environment. Some of these elements are closely related to human health and disorder. Tea is one of the most popular stimulating beverages which is consumed by low and high income family groups in many countries. Instrumental neutron activation analysis is one of the preferred methods because information on a large number of elements can be obtained simultaneously. Five packets each of the seven commonly used brands of tea were obtained from the market. In order to determine the transfer of trace elements into the drinkable portion about 2-3g. of the tea leaves were boiled in hot water for 2 min. After filtration the used tea leaves were dried at 65 deg. C in an oven and a portion, about 200mg was used for analysis. Samples and standards were irradiated 10 min. and 2 hrs. at pneumatic system and central thimble in the TRIGA MARK-II research reactor. After irradiation, the activities of samples and standards were measured with a aoaxial Ge detector coupled to a spectroscopic amplifier. A Canbera 90 model multi- channel analyzer with an 8K memory was used for pulse height analysis. The system has a resolution of 2.0 KeV. for the 1332.5 KeV gamma ray of 60Co. The activity of the sample and standard was compared and the element contst of the sample was calculated. (author)

  1. Elemental characterization of Hazm El-Jalamid phosphorite by instrumental neutron activation analysis.

    El-Taher, A; Khater, Ashraf E M

    2016-08-01

    Instrumental neutron activation analyses (INAA) have been used to achieve accurate knowledge about the elemental analysis of phosphate ore deposits collected from Hazm El-Jalamid Northeast of Saudi Arabia. The samples were prepared for irradiation by thermal neutrons using a thermal neutron flux of 7×10(12)ncm(-2)s(-1) at ACT Lab Canada. The concentrations of 19 elements were determined. These included 12 major, minor and trace elements (Au, As, Ba, Br, Cr, Mo, Sb, Sc, Sr, Th, U and Zn) and 7 rare earth elements (REEs) (La, Ce, Nd, Sm, Eu, Yb and Lu). Major elements (Si, Al, Fe, Ca, Mg, Na, K, Cr, Ti, Mn, P, Sr and Ba) were determined using an inductively coupled plasma-mass spectrometer (ICP-MS). The comparison of the concentration of U and the REEs in the Hazm El-Jalamid phosphate samples with those of the Umm Wu'al phosphate from Saudi Arabia and El-Sibayia and El Hamrawein phosphate from Egypt shows that the contents of U and REEs are clearly higher in the Umm Wu'al, El-Sibayia and El Hamrawein phosphates than in the Hazm El-Jalamid phosphate samples. The results of major, trace elements, uranium and rare earth elements (REE) from El Jalamid phosphate have been compared with the global values of these elements. The concentrations for most of the elements studied are lower than the concentrations reported in the literature. The acquired data will serve as a reference for the follow-up studies to assess the agronomic effectiveness of the Hazm El-Jalamid phosphate rocks. PMID:27235886

  2. Determination of concentrations of trace elements in nuclear grade graphite by charged particle activation analysis

    A programme has been undertaken to develop an in-house standard reference material of graphite using various analytical techniques including nuclear techniques like charged particle activation analysis (CPAA) and neutron activation analysis (NAA). The concentrations of 13 elemental impurities viz Ca, Ti, V, Cr, Fe, Ni, Cu, Zn, Ga, Ge, Sr, Zr, Mo have been determined at mg kg-1 to μg kg-1 levels in graphite by CPAA through instrumental approach using 13 and 18 MeV proton beam from cyclotron at Variable Energy Cyclotron Centre, Kolkata. The analytical results of CPAA have been validated by analyzing the same graphite samples by instrumental NAA. The validation of our analytical results has also been performed by the Z-score tests through the determination of concentrations of the elements of interest in a certified reference material (CRM) taking another CRM as standard. The experimental detection limits of all elements determined in graphite material by CPAA are also reported. (author)

  3. Overabundance of s-process elements in the atmosphere of the active red giant

    Pakhomov, Yu V

    2015-01-01

    Based on high-resolution (R=60000) spectra taken with the NES spectrograph (the 6-m BTA telescope, the Special Astrophysical Observatory of the Russian Academy of Science), we have determined the abundances of 26 elements, from lithium to europium, in the atmosphere of the active red giant PZ Mon, which belongs to the class of RS CVn variable stars, by the method of model stellar atmospheres. We have taken into account the hyperfine splitting, the isotopic shift, and the departure from local thermodynamic equilibrium. Analysis of our data has revealed an overabundance of lithium and neutron-capture elements compared to normal red giants. For lithium, this is explained by the activity of the star, while the overabundance of s-elements is presumably similar in nature to that in moderate barium stars.

  4. Elemental analysis of rain- and fresh water by neutron activation analysis

    Analysis of rain-and fresh water for trace constituents is a mandatory part of environmental monitoring. This text gives a survey of neutron activation analysis (NAA) within the framework of current environmental water research programmes, based on the practice developed in co-operation with the Dutch Energy Research Centre at Petten (ECN). While the procedures reported in literature cover about thirty five elements, The routine procedures of instrumental neutron activation analysis (INAA) is limited to ten to fifteen elements. The use of some dedicated radiochemical separations (RNAA) adds another six, some of which are speciated as well. Current contributions of NAA to water analysis center on determination and speciation of anionic trace elements, notably Br, I, As and Se on the assay of some ultra traces like Ag, Au and Hg and on validation

  5. Control of metallic trace elements in the concentrated copper by neutron activation method

    In order to value the activation analysis technique in the copper concentrates analysis, six copper concentrates were quantitatively analysed, whereas others were impossible to determine in consequence of the great radioactivities of the copper or their presence below the detection limit of the method. Among the detected elements Co, U and In are at concentrations which allow their economical recovery. (AF)

  6. Multi-element neutron activation analysis of sediment using a californium-252 source

    The application of a 252Cf source to the neutron activation analysis of several elements in small (approximately 1.5 in. in dia) cores was studied using high-resolution gamma ray spectroscopy and manual data reduction. (U.S.)

  7. Neutron activation studies of toxic elements in Czechoslovakian solid waste products

    This paper reports three uses of neutron activation analysis: to study the composition of aerosols in a low- and a high-pollution area of Bohemia; to determine the composition of fly ash samples collected from several coal-fired power plants and local heating plants; and to study element leaching from fly ash. 4 refs, 11 figs, 15 tabs

  8. Formation of MOS-transistors with isolation of active elements by oxiden porous silicon

    Novosyadlyi S. P.

    2009-06-01

    Full Text Available The superthin functional layers of MOS-transistors require qualitative isolation of active elements. The new method of formation of epitaksial structures for technology «silicon - on-isolator» is offered on the basis of porous silicon. It will allow to form three kinds of transistors — bipolar, SМОS, DМОS.

  9. Finite element based design of software for integrated passive and active vibration control

    2001-01-01

    Presents the design scheme developed for design of software forIntegrated Passive and Active Vibration Control(IPAVC) and the coding of a prototyne system, and the selection of the famous finite element program MSC/NASTRAN as an important module of software to deal with large and complicated structures and systems with an example to demonstrate the prototype system.

  10. Transient finite element simulations and experiments on active control of sound transmission loss through plates

    Brink, Maarten Cornelis

    2008-01-01

    In this thesis the sound transmission loss of a plate has been investigated. It serves as an abstract model for the noise barrier between engine and passengers in a bus. A finite element simulation model has been developed to be able to predict the plate's noise reduction effect. To increase this reduction without adding too much mass, the integration of active noise control (ANC) has been investigated. The active system contained a controller, microphones and piezoelectric actuators. The inf...

  11. Aggregation activity of blood formed elements in patients with type 1 and type 2 diabetes mellitus

    Boris Il'ich Kuznik; Yuriy Antonovich Vitkovskiy; Marina Yur'evna Zakharova; Natal'ya Nikolaevna Klyuchereva; Ol'ga Sergeevna Rodnina; Aleksey Vladimirovich Solpov

    2012-01-01

    Aims. To assess differences in blood formed elements aggregation activity in patients with type 1 (T1) and type 2 (T2) diabetes mellitus (DM). Materials and methods. We studied blood samples from 88 patients with T1 and T2 DM. Platelet aggregation activity was assessed by means of «Biola» aggregometer; we also determined platelet-lymphocyte and leucocyte-erythrocyte adhesion intensity. Results. We show that spontaneous platelet aggregation is markedly increased in patients with T1...

  12. Farnesoid X Receptor Inhibits the Transcriptional Activity of Carbohydrate Response Element Binding Protein in Human Hepatocytes

    Caron, Sandrine; Huaman Samanez, Carolina; Dehondt, Hélène; Ploton, Maheul; Briand, Olivier; Lien, Fleur; Dorchies, Emilie; Dumont, Julie; Postic, Catherine; Cariou, Bertrand; Lefebvre, Philippe; Staels, Bart

    2013-01-01

    The glucose-activated transcription factor carbohydrate response element binding protein (ChREBP) induces the expression of hepatic glycolytic and lipogenic genes. The farnesoid X receptor (FXR) is a nuclear bile acid receptor controlling bile acid, lipid, and glucose homeostasis. FXR negatively regulates hepatic glycolysis and lipogenesis in mouse liver. The aim of this study was to determine whether FXR regulates the transcriptional activity of ChREBP in human hepatocytes and to unravel the...

  13. Elemental analysis of airborne particulate by using thermal and epithermal neutron activation

    Thermal neutron activation analysis was used to determine Al, Br, Ca, Cl, Mn, Na, V, and Ti concentrations, whereas epithermal neutron activation analysis was used to determine Cu, I and Si concentrations. Counting by Compton suppression both in thermal neutron activation and epithermal neutron activation analysis showed the significantly different on detection limit of element compare with normal counting system. It revealed counting by Compton suppression gave better result. The enrichment factor of elements indicated that V and Mn were enriched in several fine particulate samples. Ca, Si and Na were not enriched, whereas Br, I and Cl were enriched in fine airborne particulate or in coarse one. It was found that Cl and Na did not have correlation, while Br and I showed the same enrichment the same enrichment trend and high correlation (0,9). It means that Br and I were from the same pollutant source. It could concluded that the thermal neutron and epithermal neutron activations analysis combined with counting by Compton suppression could enhance sensitivity of analysis of elemental air bone particulate that was very useful in air pollution study. Key words : activation analysis, thermal neutron, epithermal neutron, Compton

  14. DMPD: Activation of lymphokine genes in T cells: role of cis-acting DNA elements thatrespond to T cell activation signals. [Dynamic Macrophage Pathway CSML Database

    Full Text Available 1492121 Activation of lymphokine genes in T cells: role of cis-acting DNA elements ...html) (.csml) Show Activation of lymphokine genes in T cells: role of cis-acting ...DNA elements thatrespond to T cell activation signals. PubmedID 1492121 Title Activation of lymphokine genes in T cells: role

  15. Trace elements determination in human bone tissue by neutron activation analysis

    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 4.5x1011 n cm-2 s-1 and long irradiations of 16 hours under neutron flux of 1012 n cm-2 s-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)

  16. Insight into GATA1 transcriptional activity through interrogation of cis elements disrupted in human erythroid disorders.

    Wakabayashi, Aoi; Ulirsch, Jacob C; Ludwig, Leif S; Fiorini, Claudia; Yasuda, Makiko; Choudhuri, Avik; McDonel, Patrick; Zon, Leonard I; Sankaran, Vijay G

    2016-04-19

    Whole-exome sequencing has been incredibly successful in identifying causal genetic variants and has revealed a number of novel genes associated with blood and other diseases. One limitation of this approach is that it overlooks mutations in noncoding regulatory elements. Furthermore, the mechanisms by which mutations in transcriptionalcis-regulatory elements result in disease remain poorly understood. Here we used CRISPR/Cas9 genome editing to interrogate three such elements harboring mutations in human erythroid disorders, which in all cases are predicted to disrupt a canonical binding motif for the hematopoietic transcription factor GATA1. Deletions of as few as two to four nucleotides resulted in a substantial decrease (>80%) in target gene expression. Isolated deletions of the canonical GATA1 binding motif completely abrogated binding of the cofactor TAL1, which binds to a separate motif. Having verified the functionality of these three GATA1 motifs, we demonstrate strong evolutionary conservation of GATA1 motifs in regulatory elements proximal to other genes implicated in erythroid disorders, and show that targeted disruption of such elements results in altered gene expression. By modeling transcription factor binding patterns, we show that multiple transcription factors are associated with erythroid gene expression, and have created predictive maps modeling putative disruptions of their binding sites at key regulatory elements. Our study provides insight into GATA1 transcriptional activity and may prove a useful resource for investigating the pathogenicity of noncoding variants in human erythroid disorders. PMID:27044088

  17. Studies on cellular distribution of elements in human hepatocellular carcinoma samples by molecular activation analysis

    The distribution patterns of 17 elements in the subcellular fractions of nuclei, mitochondria, lysosome, microsome and cytosol of human hepatocellular carcinoma (HCC) and normal liver samples were investigated by using molecular activation analysis (MAA) and differential centrifugation. Their significant difference was checked by the Studient's t-test. These elements exhibit inhomogeneous distributions in each subcellular fraction. Some elements have no significant difference between hepatocellular carcinoma and normal liver samples. However, the concentrations of Br, Ca, Cd and Cs are significantly higher in each component of hepatocarcinoma than in normal liver. The content of Fe in microsome of HCC is significantly lower, almost half of normal liver samples, but higher in other subcellular fractions than in those of normal tissues. The rare earth elements of La and Ce have the patterns similar to Fe. The concentrations of Sb and Zn in nuclei of HCC are obviously lower (P<0.05, P<0.05). The contents of K and Na are higher in cytosol of HCC (P<0.05). The distributions of Ba and Rb show no significant difference between two groups. The relationships of Fe, Cd and K with HCC were also discussed. The levels of some elements in subcellular fractions of tumor were quite different from those of normal liver, which suggested that trace elements might play important roles in the occurrence and development of hepatocellular carcinoma. (authors)

  18. Trace Elements in Human Myocardial Infarction Determined by Neutron Activation Analysis

    Wester, P.O.

    1965-05-15

    By means of neutron activation analysis, injured and adjacent uninjured human heart tissue from 12 autopsy cases with myocardial infarction are investigated with respect to the concentration of 23 trace elements. The bulk elements K, Na and P are also determined. A recently developed ion-exchange technique, combined with subsequent y-spectrometry, is used. The following trace elements are determined: Ag, As, Au, Ba, Br, Ca, Cd, Ce, Co, Cr, Cs, Cu, Fe, Hg, La, Mo, Rb, Sb, Sc, Se, Sm, Zn and W. In the injured tissue compared to the uninjured, calculation on a wet weight basis showed a decrease in Co, Cs, K, Mo, P, Rb and Zn, and an increase in Br, Ca, Ce, La, Na, Sb and Sm. The differences in Ca, La, Mo, P and Zn are dependent on the age of the myocardial infarction, and the regression lines for these elements are given. The concentration of the trace elements in uninjured tissue from infarcted hearts is compared to the concentration of these elements in normal heart tissue, determined in a previous study. In the uninjured tissue from infarcted hearts a decrease is found in Cu and Mo, and an increase in As and Ce.

  19. ICE Afe 1, an actively excising genetic element from the biomining bacterium Acidithiobacillus ferrooxidans.

    Bustamante, Paula; Covarrubias, Paulo C; Levicán, Gloria; Katz, Assaf; Tapia, Pablo; Holmes, David; Quatrini, Raquel; Orellana, Omar

    2012-01-01

    Integrative conjugative elements (ICEs) are self-transferred mobile genetic elements that contribute to horizontal gene transfer. An ICE (ICEAfe1) was identified in the genome of Acidithiobacillus ferrooxidans ATCC 23270. Excision of the element and expression of relevant genes under normal and DNA-damaging growth conditions was analyzed. Bioinformatic tools and DNA amplification methods were used to identify and to assess the excision and expression of genes related to the mobility of the element. Both basal and mitomycin C-inducible excision as well as expression and induction of the genes for integration/excision are demonstrated, suggesting that ICEAfe1 is an actively excising SOS-regulated mobile genetic element. The presence of a complete set of genes encoding self-transfer functions that are induced in response to DNA damage caused by mitomycin C additionally suggests that this element is capable of conjugative transfer to suitable recipient strains. Transfer of ICEAfe1 may provide selective advantages to other acidophiles in this ecological niche through dissemination of gene clusters expressing transfer RNAs, CRISPRs, and exopolysaccharide biosynthesis enzymes, probably by modification of translation efficiency, resistance to bacteriophage infection and biofilm formation, respectively. These data open novel avenues of research on conjugative transformation of biotechnologically relevant microorganisms recalcitrant to genetic manipulation. PMID:23486178

  20. Investigation of trace elements in Elbe water by means of instrumental neutron activation analysis

    Investigations of trace elements in Elbe water were carried out as a contribution to environmental research, hydrology, and geochemistry. The method applied - instrumental neutron activation analysis - is described, and problems connected with the course of analysis - sample taking, handling and preparation as well as optimization of in-pile irradiation and measurement by means of γ spectrometry - are discussed and presented one by one. The computer programme set up for automatic evaluation is described in more detail. This programme AKAN has a very general concept which makes it applicable for general use. The reliability of the evaluation procedure - monostandard method - and the reproducibility of the results are discussed. For the studies, samples were taken at different times, every time from 8 positions along a long section of the Elbe. The content of solids was analyzed; in a number of samples, this was done by separating suspended and dissolved materials. Up to 38 elements were analyzed, whose local and time-dependent concentration curves are given. The contents of some elements are compared with the few available data from literature. Correlation calculations indicate a similar behaviour of single element groups and yield information on the natural origin of the trace elements and on anthropogenic influence to be noticed in the trace element contents. (orig.)

  1. Trace Elements in Human Myocardial Infarction Determined by Neutron Activation Analysis

    By means of neutron activation analysis, injured and adjacent uninjured human heart tissue from 12 autopsy cases with myocardial infarction are investigated with respect to the concentration of 23 trace elements. The bulk elements K, Na and P are also determined. A recently developed ion-exchange technique, combined with subsequent y-spectrometry, is used. The following trace elements are determined: Ag, As, Au, Ba, Br, Ca, Cd, Ce, Co, Cr, Cs, Cu, Fe, Hg, La, Mo, Rb, Sb, Sc, Se, Sm, Zn and W. In the injured tissue compared to the uninjured, calculation on a wet weight basis showed a decrease in Co, Cs, K, Mo, P, Rb and Zn, and an increase in Br, Ca, Ce, La, Na, Sb and Sm. The differences in Ca, La, Mo, P and Zn are dependent on the age of the myocardial infarction, and the regression lines for these elements are given. The concentration of the trace elements in uninjured tissue from infarcted hearts is compared to the concentration of these elements in normal heart tissue, determined in a previous study. In the uninjured tissue from infarcted hearts a decrease is found in Cu and Mo, and an increase in As and Ce

  2. Comparison of Elemental Composition in Korean Irradiated Foods using Instrumental Neutron Activation Analysis

    The information and role of trace mineral elements from an intake of created and processed foodstuff are important as a indicator of human health and nutritional parameter, as well as a quality control of food and diet. Particularly, special food created for consumption by astronauts in outer space may differ with common food on the earth in order to compensate a decrease of taste and nutrition by strong cosmic rays, a state of nongravitation, low pressure, and enclosed space environment. In April 2008, Korea's first astronaut became a crew member of the international space station and she was brought special space versions of Korea's national dishes such as Kimchi, boiled rice, hot red paste, green tea, ramyun, and so on. Accurate quantitative analysis of trace elements in various kinds of biological samples is also important for data quality. Neutron activation analysis is a sensitive, non-destructive, multi-elemental analytical method, and is proper for tracing elements in a biological sample in order to avoid loss and contamination by chemical pretreatment. This study analyses the distribution of concentrations for both essential and toxic elements in six kinds of Korean space foods developed by KAERI. The quantitative analytical results from instrumental neutron activation analysis are presented

  3. Comparison of Elemental Composition in Korean Irradiated Foods using Instrumental Neutron Activation Analysis

    Chung, Yong Sam; Kim, Sun Ha; Sun, Gwang Min; Lim, Jong Myung; Moon, Jong Hwa; Lee, Kye Hong; Kim, Young Jin [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Choi, Jong Il; Lee, Joo Eun [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2010-10-15

    The information and role of trace mineral elements from an intake of created and processed foodstuff are important as a indicator of human health and nutritional parameter, as well as a quality control of food and diet. Particularly, special food created for consumption by astronauts in outer space may differ with common food on the earth in order to compensate a decrease of taste and nutrition by strong cosmic rays, a state of nongravitation, low pressure, and enclosed space environment. In April 2008, Korea's first astronaut became a crew member of the international space station and she was brought special space versions of Korea's national dishes such as Kimchi, boiled rice, hot red paste, green tea, ramyun, and so on. Accurate quantitative analysis of trace elements in various kinds of biological samples is also important for data quality. Neutron activation analysis is a sensitive, non-destructive, multi-elemental analytical method, and is proper for tracing elements in a biological sample in order to avoid loss and contamination by chemical pretreatment. This study analyses the distribution of concentrations for both essential and toxic elements in six kinds of Korean space foods developed by KAERI. The quantitative analytical results from instrumental neutron activation analysis are presented

  4. Multi-element analysis of wheat flour and white bread by neutron activation

    One of the best source of feeding even for the human being as for animals are the Cereals. Although they are mainly energetic aliment, due to its composition in starch, they are a very important source of proteins and amino acids. They contribute mineral elements to the diet. Even those elements constitute a very small part of the total diet, they take a very important place in many human metabolic processes. To make a multielemental analysis of an aliment is very important that we are based on a very sensible analytic technique so we are able to find them, just as the Neutronic Activation. This Nuclear technique allows you to make a qualitative and quantitative analysis of the elements that are in a sample, but it does n't show the way in which the elements are presented. It is based in turning those elements into radioactive ones through its exposition to an uniform and constant fluid of neutrons, so then its radioactivity can be determined. The present work has as a main purpose to make a multielemental analysis of the wheat flour and white bread through the Neutronic Activation Technique, using the comparator method and establishing previously the most appropriate work conditions as much irradiation as digestion and measuring of the radioactivity of the sample. In this way, it was able to know that the wheat flour has potassium, chlorine, magnesium, sodium, iron, zinc, manganese, rubidium and selenium elements in a concentration of 2000, 700, 500, 25, 18, 13, 5.5, 0.9 and 0.01 - 0.3 mg/g respectively. In an other hand it was found that the white bread has the same elements than the wheat flour but its concentration was: 1700, 9000, 400, 7000, 52, 13, 6, 1 and 0.05 - 0.3 mg/g respectively. (Author)

  5. The determination of trace elements in new and used lubricating oils by neutron activation analysis

    The trace elements on unused and used motor oils of different brands utilized in different light, medium and heavy weight vehicles by neutron activation analysis(N A A) has been measured. To find out the exact amount of trace elements in used motor oil only due to erosion was investigated both qualitatively and quantitatively through neutron activation analysis by thermal neutrons and X ray fluorescence analysis. Forty sample of motor oil with natural basis and ten samples with synthetic basis, plus thirteen samples as filters, gas and oil rings, fix and moving bearing has been provided. For determining the quality of elements in the given samples the time of radiation for short lived elements was from one minute to ten minutes in 1 MW reactor power, using pneumatic rabbit system. The elements Al, V, Ca, and specially S have been recognized. For long lived elements the irradiation time was one hour, one and a half hour and 2 hours. As a whole, for all samples 250 time radiations have been determined. Counting of samples have been done by multichannel analyzers connected to computer P D P/11 and IBM/P C at different times from 200 seconds to 4000 seconds. The time interval between the end of irradiation till start of counting, was from three minutes to a year. Analysis of samples have been provided by software O R A C L in computer P D P/11 and software M A S T E R O in computer IBM/P C. As a whole, nine hundred spectra and analysis have been provide. Thirty one elements have been identified. They are as follows. Al, V, S, Cu, Ca, Mg, Cl, In, Mn, K, Na, As, Br, Cd, Cr, Fe, Sb, Sc, Zn, Ag, Co, Ni, Au, Cs, Eu, Sm, Lu, La, W, Xe, Ba, Hf. These elements were found in all samples. But elements La, Lu, Au, Cs, Ni, Eu, Xe, W, Ba, and Hf were found in some samples. By comparing methods with standards and using thermal neutron flux, the quantitative amounts of elements were found. By using X-ray fluorescence Zn was found in some samples and in some others (used oil) Zn, Br

  6. Atmospheric Deposition of Trace Elements in Ombrotrophic Peat as a Result of Anthropic Activities

    Fabio Lourençato, Lucio; Cabral Teixeira, Daniel; Vieira Silva-Filho, Emmanoel

    2014-05-01

    Ombrotrophic peat can be defined as a soil rich in organic matter, formed from the partial decomposition of vegetable organic material in a humid and anoxic environment, where the accumulation of material is necessarily faster than the decomposition. From the physical-chemical point of view, it is a porous and highly polar material with high adsorption capacity and cation exchange. The high ability of trace elements to undergo complexation by humic substances happens due to the presence of large amounts of oxygenated functional groups in these substances. Since the beginning of industrialization human activities have scattered a large amount of trace elements in the environment. Soil contamination by atmospheric deposition can be expressed as a sum of site contamination by past/present human activities and atmospheric long-range transport of trace elements. Ombrotrophic peat records can provide valuable information about the entries of trace metals into the atmosphere and that are subsequently deposited on the soil. These trace elements are toxic, non-biodegradable and accumulate in the food chain, even in relatively low quantities. Thus studies on the increase of trace elements in the environment due to human activities are necessary, particularly in the southern hemisphere, where these data are scarce. The aims of this study is to evaluate the concentrations of mercury in ombrotrophic peat altomontanas coming from atmospheric deposition. The study is conducted in the Itatiaia National Park, Brazilian conservation unit, situated between the southeastern state of Rio de Janeiro, São Paulo and Minas Gerais. An ombrotrophic peat core is being sampled in altitude (1980m), to measure the trace elements concentrations of this material. As it is conservation area, the trace elements found in the samples is mainly from atmospheric deposition, since in Brazil don't exist significant lithology of trace elements. The samples are characterized by organic matter content which

  7. Studies on antifungal activity and elemental composition of the medicinal plant trianthema pentendra linn

    Antifungal activity of crude solvent and aqueous extracts of the medicinal plant, Trianthema pentendra Linn., against the dermatophytic fungi, Aspergillus niger, Aspergillus flavus, Paecilomyces varioti, Microsporum gypseum and Trichophyton rubrum revealed that ethanol and aqueous extracts were the most effective antifungal agents as compared to methanol, chloroform and ethyl acetate extracts. Some basic elements, Al, Ca, Cu, Fe, Mg, Mn, P, S and Zn were also determined in the medicinal plant, T. pentendra, using atomic absorption spectrophotometry and U.V spectrophotometry. T. pentendra contained considerable amount of elements which have therapeutic effects in skin diseases. (author)

  8. Study on the sensitivity of neutron activation analysis of some elements, using a subcritical nuclear assembly

    This work describes the sensitivity levels obtained for standards prepared with some elements which, besides having a large cross section, are considered strategic materials, using a 5 Ci Pu-Be neutron source and a subcritical assembly (metallic natural uranium in light water).The irradiation conditions and the activity measurement techniques used are also reported. Finally, the possibilities of using this technique to determine the presence of the chosen elements in the concentrates and wastes from the minerals traditionally mined in the region will be discussed. (Author)

  9. Trace element exposure in man by instrumental neutron activation analysis of hair

    A nondestructive instrumental neutron activation technique was used to analyze human hair samples collected from people living in metropolitan and rural areas in Korea. Samples were also collected from factory workers and cancer patients. Hair from metropolitan area residents contain higher concentrations of Ca, Mg, Zn, Cu, Na, Br,Mn, I and S than rural area residents. Concentrations of I and S from cancer patients, Mg, Zn, Al, Na, Mn and As from glassware workers were relatively higher. The results show that the trace element concentrations of the hair are possibly related to the trace element concentrations in the body. (author)

  10. Determination of trace elements in Egyptian molasses by instrumental neutron activation analysis

    Multielement neutron activation analysis was applied to determine macro, micro and trace amounts of Al, Br, Ca, Cl, Co, Cr, Cs, Fe, K, La, Mg, Mn, Na, Rb, Sc and V in molasses of Egyptian cane sugar factories. The threshold element concentrations are acceptable and below the safety. Differences in element concentrations may be related to different botanic textures and structures, different compositions of sugar cane plants, corrosion of containers or changes in soil as a result of geochemical differentiation. The method is sensitive down to 0.038 ppm of V. The relative errors due to counting statistics are in the range of 0.2-11%. (author) 17 refs

  11. Determination of Toxic Elements in Cigarettes Smoke, Using Neutron Activation Method

    The purpose of the experiments was to get information of the toxic elements content in cigarettes smoke which could be used to estimate the cigarettes smoke contribution in air pollution. The sample were cigarette smoke from the mixture of 7 popular brand cigarettes collected by The Centre Cigarettes Research, University of kentucky, USA. Neutron activation was done in the Hoger Onderwijs Reactor, IRI Delft Netherlands, using thermal neutron flux 4.8 x 10 16n cm-2 second-1 for 4 hours. Result of the analysis showed that the cigarettes smoke contained Cd, As, Sb, and Br which are toxic elements

  12. Determination of certain elements in camel's milk by neutron activation analysis

    Natural milk samples were analysed by instrumental neutron activation analysis (INAA) for (Mn, Fe, Zn, Co, Cr, Rb, Br, I). These samples were collected from different regions of libya co-operation with camel,s research center in tripoli. In our laboratories trace elements in human and milk powder samples have been, also determined using the (INAA) technique. The concentration level of the elements of interest of interest are in agreement to within 10% with obtained values for human and powder milk, except for the concentration of Br, I, and Rb which were found to be higher in camel's milk results of this investigation will be presented. 6 figs

  13. Activation analysis in a multitechnique study of trace element imbalances in age-related neurological diseases

    It has been suggested that several age-related neurological diseases such as Alzheimer's disease and amyotrophic lateral sclerosis may be related to environmental toxins. Bulk sample multielemental analyses by INAA alone are not adequate to define the role of trace elements in these diseases. A multitechnique approach has been developed that incorporates 14 MeV, instrumental reactor, radiochemical, and pre-irradiation chemical neutron activation analysis, together with laser microprobe mass spectrometry. The analytical scheme is able to provide bulk or protein normalized elemental concentrations, as well as microstructural, cellular, and subcellular localization information. (author) 21 refs.; 3 figs.; 3 tabs

  14. Trace element determination in human bones using the neutron activation analysis method

    This work presents the results obtained in the analysis of rib bone samples from normal human individuals by applying instrumental neutron activation analysis. In these analyses, the elements Br, Cl, Fe, K, Mg, Na, Rb, Sr and Zn were found at the ppm level and the elements Ca and P at the level of percentage. The precision and the of the results were evaluated by using biological reference materials NIST SRM 1577a Bovine Liver, IAEA A-11 Milk powder, NIES CRM 9 Sargasso e NIES CRM 10A Rice Flour Unpolished. (author). 5 refs., 3 tabs

  15. Trace element analysis of human blood serum by neutron activation analysis

    An attempt was made to determine if there is any correlation between trace element concentrations in human blood serum and some specific diseases. The serum samples of the patients suffering from cancer, Down syndrome, and Banti syndrome were analyzed by the neutron activation method and compared with the trace element concentrations observed among clinically healthy men. The cancer patients had concentrations in Rb, Mn, Fe, Co, Cu, Zn, Al and Se below normal. The Down syndrome patients were found to have similar deficiencies in Cr, Mn, Fe, Co, Zn, Cu and Sb. (author)

  16. Determination of minor-and trace elements in magnesite samples, by activation analysis

    A method employing activation analysis with thermal neutron was developed for the determination of minor and trace elements in magnesite samples from the states of Ceara and Bahia (Brazil). Ten samples were analyzed. A qualitative analysis of the samples indicated the presence of Mn, Fe, Sc, Ca, Cu, Co and some of the lanthanides. The experimental part includes a non-destructive analysis of manganese and analysis with chemical separation of the other elements, individually or in groups, after sample dissolution, The dissolutions were made with concentrated HCl and the further separations were carried out in 8 N HCl medium. Iron was separated by means of an extraction of HFeCl4 with isopropyl ether. Scandium and calcium were determined by retention of scandium with di-(2-ehylhexyl) phosphoric acid (HDEHP). The activities of 46Sc and 47Sc (a 47Ca descendant) were employed for the analysis of scandium and calcium in the sample. In the effluent of the kieselguhr column copper and cobalt were determined, after retention in an anionic resin of the CuCl-3 and CoCl-3 complexes. Finally, in the effluent of the resin, the lanthanide group was separated by oxalate precipitation. In the gamma-ray spectrum of this precipitate the elements europium, cerium, samarium and lanthanum were determined. A detailed study of the possible interferences in the neutron activation analysis of the elements analysed was also made. The precision and accuracy of the results obtained and the sensitivity of the method are discussed. (Author)

  17. Controlled trial of polymeric versus elemental diet in treatment of active Crohn's disease.

    Giaffer, M H; North, G; Holdsworth, C D

    1990-04-01

    30 patients with active Crohn's disease, mean Crohn's Disease Activity Index 301 (SE 32), who would otherwise have been treated with steroids, were randomised to receive for 4 weeks either an elemental diet ('Vivonex') (n = 16) or a polymeric diet ('Fortison') (n = 14). Assessment on days 10 and 28 showed that clinical remission occurred in 5 (36%) of the 14 patients on fortison compared with 12 (75%) of the 16 patients assigned to vivonex. The difference in remission rate was significant (p less than 0.03). Dietary treatment resulted in little change in the nutritional state and various laboratory indices of activity over a 4 week period despite clinical improvement. Polymeric diets do not seem to offer an effective therapeutic alternative to elemental diets in patients with acute exacerbations of Crohn's disease. PMID:1969560

  18. Finite element analysis and validation of dielectric elastomer actuators used for active origami

    The field of active origami explores the incorporation of active materials into origami-inspired structures in order to serve as a means of actuation. Active origami-inspired structures capable of folding into complex three-dimensional (3D) shapes have the potential to be lightweight and versatile compared to traditional methods of actuation. This paper details the finite element analysis and experimental validation of unimorph actuators. Actuators are fabricated by adhering layers of electroded dielectric elastomer (3M VHB F9473PC) onto a passive substrate layer (3M Magic Scotch Tape). Finite element analysis of the actuators simulates the electromechanical coupling of the dielectric elastomer under an applied voltage by applying pressures to the surfaces of the dielectric elastomer where the compliant electrode (conductive carbon grease) is present. 3D finite element analysis of the bending actuators shows that applying contact boundary conditions to the electroded region of the active and passive layers provides better agreement to experimental data compared to modeling the entire actuator as continuous. To improve the applicability of dielectric elastomer-based actuators for active origami-inspired structures, folding actuators are developed by taking advantage of localized deformation caused by a passive layer with non-uniform thickness. Two-dimensional analysis of the folding actuators shows that agreement to experimental data diminishes as localized deformation increases. Limitations of using pressures to approximate the electromechanical coupling of the dielectric elastomer under an applied electric field and additional modeling considerations are also discussed. (paper)

  19. Determination of trace elements in human head hair by neutron activation analysis

    Instrumental neutron activation analysis was used to measure concentrations of elements in hair samples from a group of patients of a medical clinic and from a control group. Elements Al, As, Br, Ca, Cd, Cl, Co, Cu, Fe, Hg, K, Mg, Mn, Na, Sb, Sc, Se, V and Zn were analyzed and comparisons were made between the results obtained for these two groups of individuals. Normal ranges for elemental hair by commercial laboratories are also presented, for comparison, with those results obtained for the control group of individuals living in Sao Paulo, Brazil. Precision and accuracy of the results were evaluated by analyzing NIES No. 5 Human Hair and SHINR GBW09101 Human Hair reference materials. (author)

  20. Determination of trace element pathways in a petroleum distillation unit by instrumental neutron activation analysis

    The concentrations of 11 trace and minor elements (Na, Al, S, Cl, Ca, V, Mn, Ni, As, Br, I) have been measured by instrumental neutron activation analysis in a sample of crude oil from Venezuela, and in 7 of its distillates and in the final residue produced in a primary distillation unit. Concentrations range from 0.5 ppb to 2.0%. The elements have been classified in 4 categories on the basis of their distributions among the fractions analyzed. The results on concentrations have also been used to establish elemental balances in the distillation unit studied operating under steady-state conditions. Only S and V have been found to give rise to losses by emission. (author)

  1. Distribution of 35 Elements in Peat Cores from Ombrotrophic Bogs Studied by Epithermal Neutron Activation Analysis

    Frontasyeva, M V

    2004-01-01

    In ombrotrophic bogs the surface peat layer is supplied with chemical substances only from the atmosphere. Peat cores from these bogs therefore can be used to study temporal trends in atmospheric deposition of pollutants. In this work epithermal neutron activation analysis was applied for the first time to study the distribution of 35 elements in peat profiles from ombrotrophic bogs. The selected examples were from Finnmark county in northern Norway: one pristine site far from any local pollution source, and another strongly affected by long-term operation of Russian copper-nickel smelters located close to the border. The elements are classified with respect to their behavior in the uppermost 40 cm of the peat, and similarities and differences between the two profiles are discussed. As compared with other more commonly used analytical techniques based on acid decomposition of the sample ENAA has the advantage of providing the total concentrations of the elements.

  2. Finite Element Modeling of a Fluid Filled Cylindrical Shell with Active Constrained Layer Damping

    ZHANG Yi; ZHANG Zhi-yi; TONG Zong-peng; HUA Hong-xing

    2005-01-01

    On the basis of the piezoelectric theory, Mindlin plate theory, viscoelastic theory and ideal fluid equa tion, the finite element modeling of a fluid-filled cylindrical shell with active constrained layer damping (ACLD) was discussed. Energy methods and Lagrange's equation were used to obtain dynamic equations of the cylindrical shell with ACLD treatments, which was modeled as well with the finite element method. The GHM (Golla-Hughes-McTavish) method was applied to model the frequency dependent damping of viscoelastic material. Ideal and incompressible fluid was considered to establish the dynamic equations of the fluid-filled cylindrical shell with ACLD treatments, Numerical results obtained from the finite element analysis were compared with those from an experiment. The comparison shows that the proposed modeling method is accurate and reliable.

  3. Comparison of elemental contents of Korean space foods using instrumental neutron activation analysis

    The analysis of mineral contents in space foods is needed to obtain an information on a comprehensive elemental composition as well as the investigation on the effects of human nutrition and health based on the dietary intake of mineral elements. Recently, six items of new Korean space foods (KSFs) such as kimchi, bibimbap, bulgogi, a ramen, a mulberry beverage and a fruit punch which was developed by the KAERI, and the contents of more than 15 elements in the samples were examined by using instrumental neutron activation analysis (INAA). Five biological certified reference materials, NIST SRM were used for analytical quality control. The results were compared with those of common Korean foods reported, and these results will be applied toward the identification of irradiated foods. (author)

  4. Heavy metals and rare earth elements in phosphate fertilizer components using instrumental neutron activation analysis

    The technique of instrumental neutron activation analysis was applied as a sensitive nondestructive analytical tool for the determination of heavy metals and rare earth elements in phosphate fertilizer ingredients. The contents of heavy metals Fe, Zn, Co, Cr and Sc as well as rare earth elements La, Ce, Hf, Eu, Yb and Sm were determined in four samples representing the phosphate fertilizer components (e.g. rock phosphate, limestone and sulfur). These samples were collected from the Abu-Zabal phosphate factory in El-Qalubia governarate, Egypt. The aim of this study was to determine the elemental pattern in phosphate ingredients as well as in the produced phosphate fertilizer. Fair agreement was found between the results obtained for the standard reference material Soil-7 and the certified values reported by the International Atomic Energy Agency. The results for the input raw materials (rock phosphate, limestone and sulfur) and the output product as final fertilizer are presented and discussed

  5. High Resolution Ultrasound Imaging Using Adaptive Beamforming with Reduced Number of Active Elements

    Holfort, Iben Kraglund; Gran, Fredrik; Jensen, Jørgen Arendt

    In this paper, the adaptive, minimum variance ( MV) beamformer is applied to ultrasound data. Due to near-field properties, the energy of the ultrasound data reduces towards the edges of the transducer. The influence of this near-field effect is demonstrated, and a method to reduce this influence...... is proposed. By reducing the number of active sensor elements, an increased resolution can be obtained with the MV beamformer. This observation is directly opposite the well-known relation between the spatial extent of the aperture and the achievable resolution. The investigations are based on Field...... II simulated data using a 128-element transducer with a large spatial extent. The results show that an increased resolution can be obtained, when using only the central part of the transducer compared to using the entire spatial extent. Using the central 32 or 48 elements provides an increased...

  6. Neutron activation analysis for assessing the concentrations of trace elements in laboratory detergents

    Nondestructive instrumental neutron activation analysis was used to assess the concentration of 20 elements in the following laboratory detergents: Micro, Cavi-Clean liquid, RBS-35, Liqui-Nox, Treg-A-Zyme, Alcojet, Alconox, Alcotabs and Radiacwash: and a detergent additive: CaviClean additive. The upper detected limits or the concentration ranges for the detergents are (element concentration in μg/g): Ba, <20; Ce, <0.8; Cl, 27-10000; Co, <0.1; Cr, <1; Cs, <0.6; Eu, <0.009; Fe, <3-45; Hf, <0.07; Mn, <10; Ni, <5; Rb, <0.08-0.89; Sb, <0.006-1.8; Sc, <0.0003-0.008; Se, <0.05; Sr <30; Th, <0.6; U, <0.1; V, <10; Zn, <0.2-2.0. The concentrations of trace elements in the examined laboratory detergents are below those reported in the literature for household detergents. (author)

  7. Determination of rare earths and traces of other elements by neutron activation analysis

    A complete methodology for a multielemental analysis in geological material using the neutron activation technique was developed. 21 trace elements (9 of which are rare earths) were determined using thermal and epithermal neutron irradiations. Instrumetnal and radiochemical processing, applied to BCR-1 and G-2 geological standards, are described. Statistical tests carried out on G-2 data show an error smaller than 15% referring to all elements except Cr, Sb and Yb. The observed differences between are discussed. The good precision attained in this method is confirmed by its application to BCR-1 standard, which presents errors smaller than 4% for all elements except Nd, due to its intrinsic properties. The results from the present work are compared with those from other laboratories. (C.L.B.)

  8. Determination of trace elements in acid rain by reversed phase extraction chromatography and neutron activation

    A preconcentration neutron activation analysis (PNAA) method has been developed for the simultaneous determination of selected trace elements in acid rain and other water samples. The method consists of preconcentration of the elements by reversed phase extraction chromatography using oxine-loaded Amberlite XAD-2 resin. Nearly 100% recoveries were obtained for Co, Cu, Hg, V and Zn at pH 6.0 and for Cd at pH 7.0. Manganese gave incomplete recoveries at the pH range of 4.0-8.0 studies. Various factors that can influence preconcentration of the elements have been investigated in detail. The precision and accuracy of measurements have been evaluated by analyzing certified reference materials. The detection limits have been found to be of the order of ppb. The PNAA method has been applied to a number of acid rain and other water samples

  9. Trace elements in Turkish tobacco determined by instrumental neutron activation analysis

    This study was undertaken to determine the concentration of trace elements in nine different brands of Turkish cigarette tobacco, pipe tobacco and tobacco ash. Instrumental neutron activation analysis was employed, and a gamma-ray spectrometer consisting of 40 cm3 Ge(Li) detector coupled to 1024 and 4096-channel analyzers were used. Samples were irradiated at a thermal neutron flux of about 1013 cm-2 sec-1. Concentrations of Na, K, Sc, Cr, Fe, Co, Zn, As, Se, Br, Rb, Sb, Cs, Ba, La, Ce, Eu, Hf, Hg and Th were determined in tobacco and ash; percent transference of these elements into ash were calculated. It was found out that trace elements in cigarette tobacco are left in the ash but only a small percentage is transferred into the smoke

  10. Instrumental neutron activation analysis for essential and toxic elements in Kenitra city (Morocco) foods

    The aim of this study is to evaluate the sensitivity of Ko-method of Instrumental Neutron Activation Analysis for minor, trace and toxic elements in the most consumed foodstuff purchased from large commercial markets in Kenitra's city (Morocco) which has been chosen for a pilot project on food monitoring in the west of Morocco. Samples have been analyzed by Ko-INAA method using TRIGA Mark II reactor at Josef Stefan Institute in Slovenia. The quality control of results was assessed using the Standard Reference Material SRM 1547 (Peach leaves). Results show an adequate sensitivity for the most studied elements in foodstuffs except for beef, onion and whole wheat which show a high sensitivity factor for Cd and As. INAA seems to be an adequate choice for element analysis in foodstuffs. (author)

  11. Neutron activation analysis study of distribution of certain elements between plant and soil

    Some elements are recognized as essential for the optimal growth of plants but their number and their role is not clearly determined up to now. Instrumental neutron activation analysis has been employed to determine the elements arsenic, barium, bromine, cerium, europium, gold, hafnium, lanthanum, lutecium, samarium, scandium, tantalum, thorium and ytterbium in different parts of Helleborus cyclophyllus BOISS and in the soil in which the plant had grown. It has been found that bromine is selectively accumulated in plant from soil, where the value in petioles is four times higher than the value in soil while the value in leaves is about twice as high. The other elements determined show a certain distribution in plant organs but no selective accumulation. (author)

  12. Determination of rare earths and other trace elements in samples of Antarctica by neutron activation analysis

    The concentrations of REE and other trace elements have been determined in samples of Antarctica by Instrumental Neutron Activation Analysis (INAA). The samples were collected from the West Lake area near Great Wall Station. The samples include sediment, residual plants, rock and soil taken from the bottom of the lake to 3.4 m deep. The amounts of samples were very rare. In order to get more information, reactor NAA using both short and long irradiations with 'K0 standardization' has been adopted. Nine rare-earth elements (REE) namely La, Ce, Nd, Sm, Eu, Tb, Dy, Yb and Lu as well as other trace elements (As, Au, Ba, Br, Co, Cr, Hf, Sc, Se, Th, V, Zn) have been determined. The concentrations and distribution patterns of REE in the samples have been given. (author) 9 refs.; 5 figs.; 5 tabs

  13. Determination of elemental concentration in standards stainless steel by k0-standardization neutron activation analysis

    Neutron activation analysis (NAA) is used to determine the concentration of trace and major elements in a variety of matrices. k0-standardization has been implemented at TRIGA 14MW reactor. The aim of this work is to demonstrate that with k0-standardization the highest accuracy and precision can be ensured for certifying stainless steels as CRMs. Results of content of major and trace elements in two standard stainless steels samples denominated as HAAS-1 and ECRM379-1 supplied by KIMAB are presented. The experimental results are compared with the values from certificate of analysis. Thin foils with low concentration alloys were used to minimize self-shielding effects (Al-1%Mn and Al-1%Au). The values of f and a obtained in this way were used to calculate element concentration in stainless steel samples. (authors)

  14. Multi-element determination of sandstone rock by instrumental neutron activation analysis

    The instrumental neutron activation analysis technique (INAA) was used in the qualitative and quantitative analysis of sandstone samples from Aswan area in South Egypt. The samples were properly prepared together with their standards and simultaneously irradiated in a neutron flux of 7 x 1011 n/cm2.s in the TRIGA Mainz research reactor facilities. Gamma spectra from hyper pure germanium HPGe detector were analysed. The present study provides the basic data of elemental concentrations of sandstone rock. The following elements constituents have been determined: Na, K, Fe, Sc, Cr, Co, Zr, Ce, La, Nd, Sm, Eu, Yb, Lu, Hf, Ta, Th and U. The x-ray fluorescence (XRF) was used for comparison and to detect elements which can be detected only by XRF. (author)

  15. The role of neutron activation analysis for trace elements characterization, analysis and certification in atmospheric particulates

    The Neutron Activation Analysis (NAA) owns these requirements and is universally accepted as one of the most reliable analytical tools for trace and ultratrace elements determination. Its use in trace elements atmospheric pollution related studies has been and is still extensive as can be demonstrate by several specific works and detailed reviews. In this work, the application of this nuclear technique, in solving a series of different analytical problems related to trace elements in air pollution processes is reported. Examples and results are given on the following topics: characterization of urban and rural airborne particulate samples; particles size distribution in the different inhalable and respirable fractions (PM10 and PM 2.5); certification of related Standard Reference Materials for data quality assurance. (author)

  16. Peak-valley-peak pattern of histone modifications delineates active regulatory elements and their directionality.

    Pundhir, Sachin; Bagger, Frederik O; Lauridsen, Felicia B; Rapin, Nicolas; Porse, Bo T

    2016-05-19

    Formation of nucleosome free region (NFR) accompanied by specific histone modifications at flanking nucleosomes is an important prerequisite for enhancer and promoter activity. Due to this process, active regulatory elements often exhibit a distinct shape of histone signal in the form of a peak-valley-peak (PVP) pattern. However, different features of PVP patterns and their robustness in predicting active regulatory elements have never been systematically analyzed. Here, we present PARE, a novel computational method that systematically analyzes the H3K4me1 or H3K4me3 PVP patterns to predict NFRs. We show that NFRs predicted by H3K4me1 and me3 patterns are associated with active enhancers and promoters, respectively. Furthermore, asymmetry in the height of peaks flanking the central valley can predict the directionality of stable transcription at promoters. Using PARE on ChIP-seq histone modifications from four ENCODE cell lines and four hematopoietic differentiation stages, we identified several enhancers whose regulatory activity is stage specific and correlates positively with the expression of proximal genes in a particular stage. In conclusion, our results demonstrate that PVP patterns delineate both the histone modification landscape and the transcriptional activities governed by active enhancers and promoters, and therefore can be used for their prediction. PARE is freely available at http://servers.binf.ku.dk/pare. PMID:27095194

  17. Elemental characterization of some Nigerian gemstones. Tourmaline, fluorite and topaz by instrumental neutron activation analysis

    Instrumental neutron activation analysis (INAA) was employed in the determination of the major and trace element constituents in tourmaline, fluorite and topaz collected from the gemstone mineralization within a SW-NE trending pegmatite zone, central Nigeria. Cost, turnaround time, high sensitivity for certain elements, the non-destructive nature of analysis and its precision and accuracy have combined to make INAA an indispensable method for multi-element determination in virtually all geological matrices. The major element constituents in tourmaline were Al (119,800 ppm), Mn (4,348 ppm), Na (15,540 ppm) and Fe (34,290 ppm). For fluorite, Ca was the major element with a concentration of 552,000 ppm. In topaz, Al was the major constituent with a concentration of 322,800 ppm. The data suites reveal the presence of As, Br, La, Sc, Co, Hf, Ta and Sb in tourmaline, Na, As, Br, La, Yb, Co, Zn, Eu, Hf, Th in fluorite and Mg, Mn, Na, Br, La, Sc, Co and Ta as trace contaminants. No attempt was made to identify the molecular structure of the gemstones as oxygen, fluorine and silicon contents in any of them were not determined. (author)

  18. Determination of essential elements in herbal extracts by neutron activation analysis

    Different types of therapies have been introduced as an alternative treatment to various types of human disorders, among them,the use of herbal teas have been highlighted due to its low cost, easiness of acquisition and administration. The aim of this study was to evaluate the concentrations of the elements As, Ba, Br, Ca, Co, Cr, Cs, Fe, Hf, K, Na, Rb, Sb, Sc, Se, Ta, Th, U, Zn and Zr by neutron activation analysis in extracts of medicinal plants whose use is regulated by ANVISA. The relevance of this analysis is justified by the need of contributing to the recommendation of these plants as secure sources of mineral elements both for therapeutic and dietary purpose. The technique showed good sensitivity in determining the appropriate concentration of all the determined elements. Elements potentially toxic were found at concentration that do not present threats to the organism and the elements that present important roles in metabolism were determined at concentrations that can assist both therapeutic and nutritional purposes. (author)

  19. Determination of essential elements in herbal extracts by neutron activation analysis

    Francisconi, Lucilaine S.; Goncalves, Rodolfo D.M.R.; Silva, Paulo S.C. da, E-mail: lfrancisconi@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Different types of therapies have been introduced as an alternative treatment to various types of human disorders, among them,the use of herbal teas have been highlighted due to its low cost, easiness of acquisition and administration. The aim of this study was to evaluate the concentrations of the elements As, Ba, Br, Ca, Co, Cr, Cs, Fe, Hf, K, Na, Rb, Sb, Sc, Se, Ta, Th, U, Zn and Zr by neutron activation analysis in extracts of medicinal plants whose use is regulated by ANVISA. The relevance of this analysis is justified by the need of contributing to the recommendation of these plants as secure sources of mineral elements both for therapeutic and dietary purpose. The technique showed good sensitivity in determining the appropriate concentration of all the determined elements. Elements potentially toxic were found at concentration that do not present threats to the organism and the elements that present important roles in metabolism were determined at concentrations that can assist both therapeutic and nutritional purposes. (author)

  20. Simultaneous multi-element determination in some cosmetic samples of different origins using neutron activation analysis

    Instrumental neutron activation analysis (INAA) has been used to determine some trace, minor and major elements in some cosmetic samples. These samples have been randomly selected from the Egyptian market. Some of these cosmetics are imported from the world market and the others are manufactured in Egypt. Up to 25 elements have been quantitatively determined in selected cosmetic samples. These elements are: As, Br, Ba, Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Na, Sb, Sc, Sm, Rb, Ta, Tb, Th, U, W, Yb and Zn. Two certified standard reference materials have been used to assure the accuracy and precision of the technique, which are IAEA-405 and SL-1. Two different γ-radioactivity counting systems have been used and compared. Some of the analyzed samples contain some elements, which according to the list of the European Union must not be present in cosmetics. Moreover, some of these elements are present in a very high concentration. Thus, some of the analyzed samples contain arsenic, antimony, chromium and cobalt with the following respectively concentration ranges, in ppm, 0.37-3.67, 0.14-5.36, 2.94-29 768 (∝ 3%) and 0.52-4.12. (orig.)

  1. Determination of trace elements in waters and sediments by neutron activation analysis

    Methods are described of instrumental neutron activation analysis and neutron activation analysis with radiochemical separation. Trace elements in water samples are concentrated by evaporation, lyophilization, extraction, ion exchange and electrochemical concentration. Tables are used to compare the results of the direct method, i.e., without previous concentration of water samples, with the method usina lyphilization for concentration. Using NAA it is usually possible to determine Au, Br, Ca, Co, Cr, Eu, K, La, Na, Sc, U, Zn in waters, in higher concentrations also As, Se, Ag, Sb and W. The nuclear characteristics and determinability limits are given of the said elements in water. INAA may also be used to analyse bottom sediments after they have been dried and homogenized. In this type of sample it is usually possible to determine the following elements: Al, Ba, Cl, Cu, Dy, In, Mn, Sr, Ti, U and V by short-time activation (1 to 10 min), and As, Au, Br, (Cd), Ce, Co, Cr, Cs, (Cu), Eu, Fe, Ga, Hf, Hg, La, K, (Mo), Na, Rb, Sc, Se, Sm, Ta, (Zn) by several hours lasting activation. (E.F.)

  2. DEVICE FOR MEASURING OF THERMAL LENS PARAMETERS IN LASER ACTIVE ELEMENTS WITH A PROBE BEAM METHOD

    A. N. Zakharova

    2015-01-01

    Full Text Available We have developed a device for measuring of parameters of thermal lens (TL in laser active elements under longitudinal diode pumping. The measurements are based on the probe beam method. This device allows one to determine sign and optical power of the lens in the principal meridional planes, its sensitivity factor with respect to the absorbed pump power and astigmatism degree, fractional heat loading which make it possible to estimate integral impact of the photoelastic effect to the formation of TL in the laser element. The measurements are performed in a linearly polarized light at the wavelength of 532 nm. Pumping of the laser element is performed at 960 nm that makes it possible to study laser materials doped with Yb3+ and (Er3+, Yb3+ ions. The precision of measurements: for sensitivity factor of TL – 0,1 m-1/W, for astigmatism degree – 0,2 m-1/W, for fractional heat loading – 5 %, for the impact of the photoelastic effect – 0,5 × 10-6 K-1. This device is used for characterization of thermal lens in the laser active element from an yttrium vanadate crystal, Er3+,Yb3+:YVO .

  3. Development of an elemental tracer using neutron activation analysis for application in an estuarine environment

    Selection of an activable tracer that could be used to study dispersion patterns in an English estuary is described and was carried out in connection with the development and testing of a particle-tracking computer model. Understanding estuarine dynamics will assist in the decision-making process for estuarine management and in contingency planning. Neutron activation analysis (NAA) has been used to characterize the concentration and natural variation of 40 trace elements in suspended particulate matter and inter-tidal bed sediment in order to identify a suitable tracer. Results have shown that europium, terbium and ytterbium would be suitable to use in a tracer study as they have low background concentrations in sediments and little variability, (Eu: 1.31 mg x kg-1±13%, Tb: 0.90 mg x kg-1±16% and Yb: 2.91 mg x kg-1±18%). The ratios of these elements are constant throughout the estuary and experiments have shown that increases in concentration of any of these elements due to the addition of artificial elemental tracer could be quantitatively determined by changes in the ratio constant. (author)

  4. Study on the dynamics of halogen elements in the agro-environment and these element`s deficiency, toxicity and environmental hazards by the application of the neutron activation analysis method

    Yuita, Kouichi [National Inst. of Agro-Environmental Sciences, Tsukuba, Ibaraki (Japan)

    1998-03-01

    A neutron activation analysis method is an accurate and highly sensitive method for analyzing halogen elements (iodine, bromine and chlorine) except fluorine. It is unsubstitutable and valuable method especially for iodine (including radioactive {sup 129}I) and bromine which are present at lower levels. Halogen elements have high chemical and physiological activities and move widely in the environment. As a result, deficiency and an excess of halogen elements in plants and animals have occurred and artificial halogen compounds have caused environmental pollution in wide areas. We efficiently utilized the neutron activation analysis method and an activable tracer method to obtain valuable findings which contribute to the clarification of and measures against these actual problems and which are also concerned with the occurrence, distribution and migration of halogen elements in the environment, especially agricultural and forestry ecosystems in space and in time. (author)

  5. Active magnetic bearing control loop modeling for a finite element rotordynamics code

    Genta, Giancarlo; Delprete, Cristiana; Carabelli, Stefano

    1994-05-01

    A mathematical model of an active electromagnetic bearing which includes the actuator, the sensor and the control system is developed and implemented in a specialized finite element code for rotordynamic analysis. The element formulation and its incorporation in the model of the machine are described in detail. A solution procedure, based on a modal approach in which the number of retained modes is controlled by the user, is then shown together with other procedures for computing the steady-state response to both static and unbalance forces. An example of application shows the numerical results obtained on a model of an electric motor suspended on a five active-axis magnetic suspension. The comparison of some of these results with the experimental characteristics of the actual system shows the ability of the present model to predict its performance.

  6. Determination of trace elements in NIES environmental reference materials by instrumental neutron activation analysis

    Concentrations of trace elements in environmental reference materials prepared by the National Institute for Environmental Studies of Japan (NIES) were determined by instrumental neutron activation analysis (INAA). Mussel, Human Hair, Tea Leaves and Sargasso reference material samples (ca. 150∼1200 mg) were irradiated by thermal neutron without cadmium filter and epithermal neutron with cadmium filter at Musashi Institute of Technology Research Reactor (MITRR). The activated samples were measured by three methods; conventional γ-ray spectrometry using a coaxial Ge detector, anticoincidence counting spectrometry and coincidence counting spectrometry. The γ-ray spectrometric system (GAMA system) was developed by the authors. As a result, they could determined about 30 - 50 elements by the combination of these irradiation and counting methods. The analyzed values were in good agreement with NIES certified values

  7. Active magnetic bearing control loop modeling for a finite element rotordynamics code

    Genta, Giancarlo; Delprete, Cristiana; Carabelli, Stefano

    1994-01-01

    A mathematical model of an active electromagnetic bearing which includes the actuator, the sensor and the control system is developed and implemented in a specialized finite element code for rotordynamic analysis. The element formulation and its incorporation in the model of the machine are described in detail. A solution procedure, based on a modal approach in which the number of retained modes is controlled by the user, is then shown together with other procedures for computing the steady-state response to both static and unbalance forces. An example of application shows the numerical results obtained on a model of an electric motor suspended on a five active-axis magnetic suspension. The comparison of some of these results with the experimental characteristics of the actual system shows the ability of the present model to predict its performance.

  8. Trace element determination study in human hair by neutron activation analysis

    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 5x1012 n cm-2 s-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 non-dyed hair

  9. Determination of trace elements of Egyptian crops by neutron activation analysis Pt. 2

    Neutron activation analysis, NAA, a high resolution Ge(Li) gamma ray spectrometer was used to determine the concentration of Al, As, Au, Br, Ca, Cd, Co, Cr, Cu, Fe, La, Mn, Mo, Sb, Se, W, and Zn in Cumin, coriander, carrots, and Daucus carota (Umbelliferae Family), alfalfa, Kidney bean, Phaseolus sativus, Phaseolus vulgaris, bean, lentil, and fenugreek (Legumirosae Family). Multielement determination technique on destructive and nondestructive samples was followed. This method is simple, precise and sensitive to 17 trace elements. (author)

  10. Determination of trace elements in a cigarette paper by neutron activation analysis

    The concentration of 19 trace elements in a cigarette paper (Zig-Zag Paper Company, France) which is used in making different brands of Iranian cigarettes, has been measured by neutron activation analysis, employing a high-resolution Ge(Li) detector. They include Na, K, Ca, Sc, Cr, Mn, Fe, Co, Zn, Br, Sr, Sb, Ba, Ce, Eu, Gd, Au, Hg, and Th. (author)

  11. Thin-disk laser based on an Yb:YAG / YAG composite active element

    Kuznetsov, I. I.; Mukhin, I. B.; Vadimova, O. L.; Palashov, O. V.

    2015-03-01

    A thin-disk laser module based on an Yb:YAG / YAG composite active element is developed with a small-signal gain of 1.25 and a stored energy of 400 mJ under cw pumping. The gain and thermally induced phase distortions in the module are studied experimentally. Based on this module, a thin-disk laser with an average power of 300 W and a slope efficiency of 42% is designed.

  12. A study on chemical element determinations in human nails by neutron activation analysis

    Sanches, Thalita Pinheiro; Saiki, Mitiko, E-mail: thalitapsanches@usp.br, E-mail: mitiko@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Nail analyses have been the object of study in order to assess the levels of elements accumulated in the human organism and to use this tissue to monitor environmental and occupational exposure, to evaluate the nutritional status, to verify intoxication by toxic metals and to diagnose or to prevent diseases. Nail analyses present advantages due to easy sample collection, storage, transportation and this tissue provides element level accumulation over time. However, there is controversy regarding the application of nail analysis data due to difficulties to establish reliable reference values or element concentration ranges as control values. The objective of this study was to evaluate the factors that can affect nail element concentrations for further sample analyses of a group of individuals by applying neutron activation analysis (NAA). Fingernails and toenails collected from adult individuals of both genders, aged 18 to 71 years, living in the Sao Paulo Metropolitan Region were cut in small fragments, cleaned and dried for analyses. Samples and element standards were irradiated for 16 h under a thermal neutron flux of about 4.5 x 10{sup 12} n cm{sup -2} s{sup -1} at the IEA-R1 nuclear research reactor followed by gamma ray spectrometry. Element concentrations for As, Br, Ca, Co, Cr, Cs, Fe, K, La, Na, Rb, Sb, Sc, Se and Zn were determined. For quality control of the analytical results, certified reference materials were analysed and the results showed good accuracy and precision with relative errors and relative standard deviations lower than 5.1 % and 11.6 %, respectively. Preliminary assays indicated that the contribution due to impurities from plastic involucres used in the irradiation as well as those from nail polishes is very low and could be considered negligible. Results from the nail sample cleaning process using distinct procedures indicated that HNO{sub 3} solution may cause sample dissolution. Sample homogeneity was verified by analysis of a sample in

  13. A study on chemical element determinations in human nails by neutron activation analysis

    Nail analyses have been the object of study in order to assess the levels of elements accumulated in the human organism and to use this tissue to monitor environmental and occupational exposure, to evaluate the nutritional status, to verify intoxication by toxic metals and to diagnose or to prevent diseases. Nail analyses present advantages due to easy sample collection, storage, transportation and this tissue provides element level accumulation over time. However, there is controversy regarding the application of nail analysis data due to difficulties to establish reliable reference values or element concentration ranges as control values. The objective of this study was to evaluate the factors that can affect nail element concentrations for further sample analyses of a group of individuals by applying neutron activation analysis (NAA). Fingernails and toenails collected from adult individuals of both genders, aged 18 to 71 years, living in the Sao Paulo Metropolitan Region were cut in small fragments, cleaned and dried for analyses. Samples and element standards were irradiated for 16 h under a thermal neutron flux of about 4.5 x 1012 n cm-2 s-1 at the IEA-R1 nuclear research reactor followed by gamma ray spectrometry. Element concentrations for As, Br, Ca, Co, Cr, Cs, Fe, K, La, Na, Rb, Sb, Sc, Se and Zn were determined. For quality control of the analytical results, certified reference materials were analysed and the results showed good accuracy and precision with relative errors and relative standard deviations lower than 5.1 % and 11.6 %, respectively. Preliminary assays indicated that the contribution due to impurities from plastic involucres used in the irradiation as well as those from nail polishes is very low and could be considered negligible. Results from the nail sample cleaning process using distinct procedures indicated that HNO3 solution may cause sample dissolution. Sample homogeneity was verified by analysis of a sample in replicate. A comparison

  14. Neutron Activation Analysis and High Resolution Gamma-Ray Spectrometry Applied to Areal Elemental Distribution Studies

    Schuiling (1967) applied both 'metallogenetic province' and continental drift principles to a study of the world-wide distribution of tin. A plot of tin deposit occurrences on the continents reconstituted as 'Pangeae' yielded 'tin belts' joining intercontinentally between the Americas, Africa and Europe. Discussions with Sir John Cockcroft and Sir Edward Bullard, in April 1967, led to this study of the applicability of automated, instrumental thermal neutron activation analysis techniques to large-scale areal elemental distribution determinations related to continental drift and to metallogenesis. The Enchanted Rock batholith, Llano, Texas, was selected as an initial area in which to apply this method on the basis of the availability of independent geochemical information concerning the pluton from Hutchinson (1956), Billings (1963) and Ragland (1968). Rock samples, including points from areas outside the batholith, were obtained at each of 16 sampling sites. One-gram rock samples were irradiated in a thermal neutron flux of ≈2 x 1012 n/cm2 s for 2 hours. Six trace elements (Hf, Ta, Co, Eu, Sc and La), and one minor element (Fe), were determined by gamma-ray spectrometry utilizing a 19 cm3 Ge(Li) detector and a 3200-channel analyser, and were areally mapped. The results indicate continuous trends in each trace element, through various rock types, over a distance of greater than 50 miles. The trace elements of pyrite, chalcopynte and sphalerite obtained from the Philippine Islands were measured in order to apply this procedure to minerals in a location where their areal extent has not previously been extensively studied. The methodology described above was repeated. A set of average element abundances in chalcopynte, pyrite and sphalerite is suggested on which to base the presence or absence of an element province or combined elements provinces. Preliminary results indicate the presence of a gold province in the northwestern part of Luzon Island. This technique

  15. Activation analysis of hair as an indicator of contamination of man by environmental trace element pollutants

    The burning of fossil fuel, discharges from metallurgical and chemical plants, the wide use of chemicals, and other human activities, result in releasing into the biosphere large quantities of elements which are found in relatively low concentrations in the human organism. The pollution of the biosphere by such trace elements, and in particular heavy metals, has reached such proportions that on the scale of significance of the factors causing the 'stressed' state of the environment of heavy metals occupy the second place and, according to forecasts, may in the future move on to the first. In the problem of pollution of the biosphere, man himself undoubtedly occupies the central position as a target. The pollution of air, soil and water, the contamination of micro-organisms, plants and animals are certainly growing into a serious threat and leading to heavy losses. However, it would be a real disaster if man himself became contaminated to levels giving rise to large scale harmful somatic or genetic effects. It is therefore an urgent problem today to determine the initial levels of trace elements in man and the extent of his contamination in areas where these elements are expected to show anomalous concentrations. Attention should be paid in the first place to those trace elements which probably play no physiological role, are particularly abundant in the environment, and have high toxicity (arsenic, mercury, lead, cadmium, etc.). Moreover, it should be born in mind that in anomalously high concentrations even the physiologically necessary trace elements (copper, zinc, manganese, fluorine, etc.) cause harmful effects. This paper justifies the use of hair samples as a biological indicator of environmental pollutants from physiological and morphological aspect and recommends on sample preparation and analysis methods

  16. Trace element characteristics of indian cigarette tobacco by instrumental neutron activation analysis

    In order to determine hazardous effects of smoking five different brands of Indian cigarette tobacco including its ash and smoke, three brands of bi di (a typical of Indian subcontinent) and two of chewing tobacco have been analysed for 24 elements (As, Ba, Br, Ca, Ce, Co, Cr, Cs, Cu, Eu, Fe, Hg, K, Hf, La, Na, P, Rb, Sb, Sc, Se, Sr, Th and Zn) by instrumental neutron activation analysis (INAA). A simple and indigenous smoking device has been developed. A mean ash content of 16.5 ± 1.1% was obtained for different brands of cigarettes whereas smoke content was found to be 4.8±0.8%. It is observed that most elements are retained in ash and a few are transferred to smoke. Percent amount of elements retained in ash and transferred to smoke condensate have been calculated. Significant amounts of Sb, Hg, Co, Se and Zn are transferred to smoke but >90% of Ca, Fe, Sr and Cr are retained in ash. a comparison of elemental contents with the cigarette tobacco from other countries shows comparable amounts for most elements except few minor variations attributable to local soil characteristics. Most elemental contents in bi di and chewing tobacco are comparable except Br, Cr, Na, Se and Sr which are higher in chewing tobacco but its Ca content is lower. Standard Reference Materials Bowen's Kale, Kentucky Reference Cigarette and Citrus Leaves (SRM 1572) along with a newly developed tobacco CRM OTL-1 from Poland were also analysed. (author). 31 refs., 1 fig., 4 tabs

  17. Background levels of some trace elements in egyptian soils determined by neutron activation analysis

    As part of a research program on the influence of agricultural practices and activities on soil content of heavy metals. The present work was carried out to investigate the feasibility of instrumental neutron activation analysis for this purpose. Elements studied were, Fe, Zn, Co, Sc, Sb, As, Cd, Hg and Cr. The soil samples analyzed were from different locations to represent different land uses and types. Results revealed that As, Cd and Hg show a pronounced accumulation in soils especially those exposed to industrial and organic wastes disposal. 2 tabs

  18. Characterization of active miniature inverted-repeat transposable elements in the peanut genome

    Shirasawa, Kenta; Hirakawa, Hideki; Tabata, Satoshi; Hasegawa, Makoto; Kiyoshima, Hiroyuki; Suzuki, Sigeru; Sasamoto, Sigemi; Watanabe, Akiko; Fujishiro, Tsunakazu; Isobe, Sachiko

    2012-01-01

    Miniature inverted-repeat transposable elements (MITEs), some of which are known as active non-autonomous DNA transposons, are found in the genomes of plants and animals. In peanut (Arachis hypogaea), AhMITE1 has been identified in a gene for fatty-acid desaturase, and possessed excision activity. However, the AhMITE1 distribution and frequency of excision have not been determined for the peanut genome. In order to characterize AhMITE1s, their genomic diversity and transposition ability was i...

  19. The effects of trace elements, cations, and environmental conditions on protocatechuate 3,4-dioxygenase activity

    Andréa Scaramal da Silva

    2013-04-01

    Full Text Available Phenanthracene is a highly toxic organic compound capable of contaminating water and soils, and biodegradation is an important tool for remediating polluted environments. This study aimed to evaluate the effects of trace elements, cations, and environmental conditions on the activity of the protocatechol 3,4-dioxygenase (P3,4O enzyme produced by the isolate Leifsonia sp. in cell-free and immobilized extracts. The isolate was grown in Luria Bertani broth medium (LB amended with 250 mg L-1 of phenanthrene. Various levels of pH (4.0-9.0, temperature (5-80 °C, time (0-90 min, trace elements (Cu2+, Hg2+ and Fe3+, and cations (Mg2+, Mn2+, K+ and NH4+ were tested to determine which conditions optimized enzyme activity. In general, the immobilized extract exhibited higher enzyme activity than the cell-free extract in the presence of trace elements and cations. Adding iron yielded the highest relative activity for both cell-free and immobilized extracts, with values of 16 and 99 %, respectively. Copper also increased enzyme activity for both cell-free and immobilized extracts, with values of 8 and 44 %, respectively. Enzyme activity in the phosphate buffer was high across a wide range of pH, reaching 80 % in the pH range between 6.5 and 8.0. The optimum temperatures for enzyme activity differed for cell-free and immobilized extracts, with maximum enzyme activity observed at 35 ºC for the cell-free extract and at 55 ºC for the immobilized extract. The cell-free extract of the P3,4O enzyme exhibited high activity only during the first 3 min of incubation, when it showed 50 % relative activity, and dropped to 0 % after 60 min of incubation. By contrast, activity in the immobilized extract was maintained during 90 min of incubation. This isolate has important characteristics for phenanthrene biodegradation, producing high quantities of the P3,4O enzyme that forms part of the most important pathway for PAH biodegradation.

  20. Analysis of the impact of financial system elements of Ukraine at objects of innovation activity

    Iryna Fedyshyn

    2015-11-01

    Full Text Available The article considers the influence of the elements of the financial system at objects of innovation activity in Ukraine. The definition of the financing system of innovative activity and characteristics of its basic elements: financing facilities, government institutions and funds at national, regional and local significance and non-state agents are given. The forms of public funding of innovation activities (direct and indirect methods of financial incentives are analyzed. In the article the features of functioning of joint investment institutions and the effectiveness of investments of venture capital funds into innovative activities in Ukraine are viewed. It was found that venture capital is not a basic or sufficient to stimulate high-tech development in Ukraine, since venture capital funds tend to invest in construction, recycling of agricultural production, food processing, retail trade. The analysis of the proportion of funding sources of innovation for 2013-2014 years is made. Proposals for improvement of methods application and means of financing of innovative activity in Ukraine are given.

  1. Peak-valley-peak pattern of histone modifications delineates active regulatory elements and their directionality

    Pundir, Sachin; Bagger, Frederik O; Lauridsen, Felicia K B; Rapin, Nicolas; Porse, Bo T

    2016-01-01

    from four ENCODE cell lines and four hematopoietic differentiation stages, we identified several enhancers whose regulatory activity is stage specific and correlates positively with the expression of proximal genes in a particular stage. In conclusion, our results demonstrate that PVP patterns......Formation of nucleosome free region (NFR) accompanied by specific histone modifications at flanking nucleosomes is an important prerequisite for enhancer and promoter activity. Due to this process, active regulatory elements often exhibit a distinct shape of histone signal in the form of a peak...... that NFRs predicted by H3K4me1 and me3 patterns are associated with active enhancers and promoters, respectively. Furthermore, asymmetry in the height of peaks flanking the central valley can predict the directionality of stable transcription at promoters. Using PARE on ChIP-seq histone modifications...

  2. Creative elements: network-based predictions of active centres in proteins, cellular and social networks

    Csermely, Peter

    2008-01-01

    Active centres and hot spots of proteins have a paramount importance in enzyme action, protein complex formation and drug design. Recently a number of publications successfully applied the analysis of residue networks to predict active centres in proteins. Most real-world networks show a number of properties, such as small-worldness or scale-free degree distribution, which are rather general features of networks from molecules to the society. Based on extensive analogies I propose that the existing findings and methodology enable us to detect active centres in cells, social networks and ecosystems. Members of these active centres are creative elements of the respective networks, which may help them to survive unprecedented, novel challenges, and play a key role in the development, survival and evolvability of complex systems.

  3. Comparative measurement of inorganic elements in Korean space foods using instrumental neutron activation analysis

    In April 2008, Korea's first astronaut became a crew member of the international space station and she brought special space versions of traditional Korean dishes such as kimchi, boiled rice, hot red pepper paste, soybean paste soup, ginseng tea, green tea, and ramyun. To date, seventy kinds of Korean space foods (KSFs) have been developed by KAERI. The information and role of trace mineral elements from an intake of created and processed foodstuff are important as a indicator of human health and nutrition, as well as a quality control of food and diet. In particular, special food created for consumption by astronauts in outer space may differ with common food on the earth to compensate a decrease in taste and nutrition by hygienic sterilization processing as well as strong cosmic rays, a state of non gravitation, low pressure, and an enclosed space environment. An accurate quantitative analysis of trace elements in various kinds of biological samples is serious work for analytical data quality. An neutron activation analysis is a sensitive, non destructive, multi elemental analytical method without loss and contamination of a sample by chemical pre treatment. The aim of this study is to identify and to compare the distribution of concentrations for essential and functional inorganic elements in six kinds of Korean space foods developed by KAERI in 2011 using INAA

  4. Characteristic of elements in coal bottom ash and fly ash by instrumental neutron activation analysis (INAA)

    Coal-fired power plant and industrial stacks that using coal produce solid waste such as bottom ash and fly ash. Determination of elements in these wastes qualitatively and quantitatively is usually the first step taken for subsequent evaluation of the associated environmental and biological risks. In this study, the determination of trace elements in bottom ash and fly ash by instrumental neutron activation analysis was carried out. The samples were irradiated at rabbit facility in G.A. Siwabessy reactor with neutron flux ~ 1013 n.cm-2.s-1, and then counted by HPGe spectrometer gamma detector. The validation of method was performed by characterization of standard reference material (SRM) 1633b coal fly ash from National Institute of Standards and Technology (NIST). Some elements such as Al, As, Ce, Co, Cr, Cs, Fe, K, La, Mn, Na, Sc, Sm, Ti and V were detected in both samples. The concentration of environmentally toxic elements, As and Cr in bottom ash were 6.24 and 137.4 mg/kg, whereas in fly ash were 6.37 and 39.0 mg/kg respectively. Arsenic concentrations had been over the standard value based on PP no.85/1999. (author)

  5. Comparative measurement of inorganic elements in Korean space foods using instrumental neutron activation analysis

    Chung, Yong Sam; Kim, Sun Ha; Baek, Sung Ryel; Sun, Gwang Min; Moon, Jong Hwa; Choi, Jong Il; Lee, Joo Eun [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    In April 2008, Korea's first astronaut became a crew member of the international space station and she brought special space versions of traditional Korean dishes such as kimchi, boiled rice, hot red pepper paste, soybean paste soup, ginseng tea, green tea, and ramyun. To date, seventy kinds of Korean space foods (KSFs) have been developed by KAERI. The information and role of trace mineral elements from an intake of created and processed foodstuff are important as a indicator of human health and nutrition, as well as a quality control of food and diet. In particular, special food created for consumption by astronauts in outer space may differ with common food on the earth to compensate a decrease in taste and nutrition by hygienic sterilization processing as well as strong cosmic rays, a state of non gravitation, low pressure, and an enclosed space environment. An accurate quantitative analysis of trace elements in various kinds of biological samples is serious work for analytical data quality. An neutron activation analysis is a sensitive, non destructive, multi elemental analytical method without loss and contamination of a sample by chemical pre treatment. The aim of this study is to identify and to compare the distribution of concentrations for essential and functional inorganic elements in six kinds of Korean space foods developed by KAERI in 2011 using INAA.

  6. High Z elements in human sarcomata: assessment by multienergy CT and neutron activation analysis

    Tumor equivalent phantoms containing inorganic salts (KH2PO4, CH3COOK, NaCl and KI) were scanned on an EMI 5005 body scanner at 140 kVp, 28 mA; 120 kVp, 33 mA; and 81 kVp, 42 mA. Significant signal gain for the detection of higher atomic number elements by multiple energy scanning was noted. Certain sarcomas are known to accumulate high Z elements. Accordingly, excised specimens of various histologies of human sarcomata (chondrosarcoma, liposarcoma, and malignant fibrous histiocytoma) were scanned at 140 kVp and 81 kVp. Using selected areas of interest in the computed tomographic (CT) image to direct the in vitro biopsy of various regions of excised tumors, intersting correlations between the CT number variation and the respective, high Z elemental composition variation, as determined by thermal neutron activation analysis were observed. Further investigation with phantoms and excised sarcomata at 62 kVp and 42 mA suggested that dual energy CT scanning (at 140 kVp and 62 kVp) may be a method of monitoring effective Z and heavy element compositional changes. The authors are also attempting to develop these same low kilovoltage techniques as a method for the noninvasive clinical monitoring of an antisarcoma chemotherapeutic agent, cis-diamminedichloroplatinum

  7. Application of neutron activation analysis to the detrmination of toxic elements in Australian foodstuffs

    Recent measurements in our laboratory have indicated that the average selenium content in the plasma of Australians is 0.09 mg L-1 which is significantly lower than that found in the inhabitants of most other Western countries with the exception of New Zealand. Research aimed at explaining these low levels had begun when an invitation was received from the IAEA to join a Coordinated Research Programme on Nuclear Techniques for Toxic Elements in Foodstuffs. The investigation was widened, therefore, to include other toxic elements, arsenic, mercury, zinc and antimony and the suite of trace elements determined by neutron activation analysis (NAA) techniques. To complete the survey of toxic elements, the lead and cadmium of the chosen foodstuffs are being analysed by anodic stripping voltammetry (ASV) and soon will be examined by inductively coupled plasma mass spectrometry (ICPMS). Drinking water from a number of locations were sampled in cleaned, screw-top polystyrene containers, frozen and stored in a freezer until ready for analysis. 7 refs, 4 figs, 4 tabs

  8. Dynamics of elements in soil treated with increasing doses sewage sludge for instrumental neutron activation analysis

    In this work the dynamics of the elements was analyzed The, Br, Ce, Co, Cr, Cs, Fe, Hf, La, In the, Sb, Sc, Sm, Ta, Th, U, Yb and Zn in a profile of a red-yellow latossolo, in the depths of 0-5, 5-10, 10-30 and 30-50 cm, and dose of the biosolid of 0, 25, 124 and 375 t ha-1, of the station of treatment of sewer of Barueri, Sao Paulo. The experiment was carried out in areas of 3,05 m2 in the times of 2,2; 4,0; 6,6; 14,3 and 21 months. For analysis of the elementary composition, it was used of the analysis technique by instrumental neutron activation analysis (INAA). The experiment was submitted under normal tropical conditions in a forest station in Itatinga, Sao Paulo, of the University of Sao Paulo. For better details, the factors depth, doses and times statistical analyses of the results of the elementary composition of the soil samples were made. For all the biossolid doses conditioned with polymeric and applied in the soil, the composition of 17 of the 18 elements in the soil were not altered, with exception for Cr in the studied times. The elements As, Br, Ce, Co, Fe, Hf, La, Sm, Ta, Th, U and Yb presented higher levels in the deepest layers of soil; already the elements Cr, In the, Sb and Zn presented higher concentrations in the superficial layers. (author)

  9. Experimental analysis of biasing elements for dielectric electro-active polymers

    Hodgins, Micah; Seelecke, Stefan

    2011-04-01

    This paper presents an experimental investigation of three different, small profile and scalable DEAP actuators. These actuators are designed for use in small scale pumping and valve applications. The actuators used in this paper consist of a biasing element (either a mass, linear spring, or a non-linear spring) coupled with a circular dielectric electro-active polymer (DEAP). These mechanisms bias the DEAP allowing out-of-plane actuation when the voltage is cycled. A constant force input, a linear spring, and a non-linear spring are separately tested as the biasing element of a circular/diaphragm DEAP. Tests are systematically performed at various DEAP pre-deflections, biasing stiffness and electrical loading rates. The displacement stroke performance of each test is examined and analyzed. It was found that the non-linear spring provided the largest displacement stroke over two other biasing elements. It also showed better performance at higher electrical loading rates. Thus, of the three types of biasing tested the non-linear spring shows most promise for use in fluid pump/valve applications. Future work will include optimizing this biasing element for the current DEAP design.

  10. Determination os essential elements in diet and light foods using neutron activation analysis

    The object of this study was to determine essential elements on the diet and light foods and their normal similar through the neutron activation analysis (NAA) and to compare their results. Samples of sweetning, cappuccino, gelatine and chocolate collected at the Sao Paulo commerce were irradiated by a period of 8 hours, under a 1012 n cm-2 s-1 thermal neutron flux at the IEA-R1 research reactor - IPEN/CNEN-SP, Brazil, together with reference materials and elementary standards, for the determination the concentrations of Br, Ca, Cr, Co, K, Na, Fe, Se and Zn. The obtained results shown that the diet gelatine samples presented concentrations higher for determined elements related to the light and normal gelatines samples. Compared with cappucino samples there was not differences among the concentrations of the determined elements, excepted the element Cr for the cappuccino light. For the chocolate light they presents higher values related to the normal type. The sweetening did not present differences among the samples. (author)

  11. Rare earth element (REE) in surface mangrove sediment by instrumental neutron activation analysis

    A study is carried out on the concentrations of rare earth element (REE) elements present in surface mangrove sediments from 10 locations throughout west coast Malaysia. In carrying out the analysis, the best and most convenient method being the instrumental neutron activation analysis (INAA). Samples were obtained, dried, crushed to powdery form and samples prepared for INAA. All the samples for analysis were weighted approximately 150 mg for short irradiation and 200 mg for long irradiation time. As calibration and quality control procedures, blank samples, standard reference material SL-1 were then irradiated with thermal neutron flux of 4 × 1012 cm-2 s-1 at the MINT TRIGA Mark II research reactor which operated at 750 kW by using a pneumatic transport facility. The REE elements of surface sediment samples in this study are Dy, Sm, Eu,Yb, Lu, Tb, La and Ce. It was found that the level of concentrations of all the REE elements varies in the range (0.35-117.4 mg/kg). The geochemical behavior of REEs in surface sediments and normalized pattern (chondrite and shale) has been studied. The degree of sediments contaminations were computed using an enrichment factor. The results showed that the enrichment factor varied in the range (0.75-6.75). (author)

  12. Determination of Trace Elements in Ghanaian Shea Butter and Shea Nut by Neutron Activation Analysis (NAA

    Erwin Alhassan

    2011-01-01

    Full Text Available The aim of the study is to determine the concentrations of trace elements in Ghanaian shea nut and shea butter. As part of the study, measurements of the elemental composition of shea butter and shea nut samples were carried out by Neutron Activation Analysis (NAA using the Ghana Research Reactor-1 (GHARR-1. Samples collected from local markets in the Northern region of Ghana and the National Institute of Standards and Technology (NIST Standard Reference Material (SRM 1547 Peach leaves were irradiated at the GHARR-1 facility. Validation of the method was done using NIST SRM Orchard Leaves (1571 under the same experimental conditions. Six trace elements (Na, Mn, Al, Cl, Ca and K were detected with maximum concentration of Na found to be 15±1 mg/kg in SN5, Mn; 7.4±0.8 mg/kg in SN6, Al; 259±3 mg/kg in SN1, Cl; 666±27 mg/kg in SN1, Ca; 0.21±0.04 wt.% in SN4, K; 2.0±0.04 wt.% in SN1, Ce; 3.2±0.06 mg/kg in SN2, Se; 0.12±0.004 mg/kg in SN4, and Sc; 0.40±0.02 mg/kg in SN2 . The concentrations of the trace elements were within the limit laid down for safe human consumption.

  13. Trace Elements in the Conductive Tissue of Beef Heart Determined by Neutron Activation Analysis

    By means of neutron activation analysis, samples of four beef hearts taken from the bundle of His and adjacent ventricular muscle, the AV node and adjacent atrial muscle are investigated with respect to the concentration of 23 trace elements. The bulk elements K, Na and P are also determined. A recently developed ion-exchange technique, combined with subsequent γ-spectrometry, is used. The following trace elements are determined: Ag, As, Au, Ba, Br, .Ca, Cd, Ce, Co, Cr, Cs, Cu, Fe, Hg, La, Mo, Rb, Sb, Sc, Se, Sm, W and Zn. In the conductive tissue compared to adjacent muscle tissue, calculations on a wet weight basis show a lower concentration of Cs, Cu, Fe, K, P, Rb and Zn in the former, and a higher concentration of Ag, Au, Br, Ca and Na. The mean differences (μg/g wet tissue), as well as their degree of significance, between the bundle of His and adjacent tissue from the ventricular septum, between the AV node and adjacent atrial muscle, between the ventricular septum and the right atrium, and between the bundle of His and the AV node are given for the elements Cu, Fe, K, Na, P and Zn

  14. Application of neutron activation analysis to trace element determinations in lung samples

    The purpose of this work was to apply the instrumental neutron activation analysis method to determine trace elements in lung samples from smokers and non smokers. Samples of lung tissues and lymph nodes from pulmonary hilum analyzed were collected from autopsies by researchers from the Medicine College of the University of Sao Paulo, SP, Brazil. Adequate conditions for preparation and analysis of samples were previously established. The preparation of samples consisted of homogenization, lyophilization and sterilization in 60Co source. The samples and standards were irradiated in the IEA-R1 reactor under thermal neutron flux of 3.7 x 1011 n.cm-2.s-1 for 30 min to determine Cl, K, Mn and Na and for 16 h under flux of 1019 n.cm-2.s-1 for the determination of Au, Br, Ce, Co, Cr, Cs, Eu, Fe, Hf, La, Rb, Sb, Sc, Se, Th and Zn. The counting were carried out with a hiperpure (ge) detector connected to a 4096 channels analyzer and a microcomputer. the results obtained for lung sample analyses indicated a good reproducibility of the method for most of the elements determined with relative standard deviations lower than 10.5%. The accuracy of the method was evaluated by analyzing reference materials such as IAEA Animal Muscle H-4, NIST Bovine Liver 1577a, IUPAC Bowen's Kale and NIES Vehicle Exhaust Particulates. The results obtained from these analyzes agreed with the values of the literature for several elements with relative errors less than 20%. Less precise and accurate results were obtained for elements with concentrations at the Mup/Kg levels. Elemental concentrations obtained in the lung tissue analyses were within the range of reference values for normal subjects presented in the literature, except for the Cl concentrations for non smokers, Hf in both groups and Sb for the smokers. By comparing results obtained for lung samples from smokers and non smokers, the concentrations of Ce, Cr and Sb were higher in lungs from smokers and the others elements were found in

  15. The Importance of Landscape Elements for Bat Activity and Species Richness in Agricultural Areas.

    Olga Heim

    Full Text Available Landscape heterogeneity is regarded as a key factor for maintaining biodiversity and ecosystem function in production landscapes. We investigated whether grassland sites at close vicinity to forested areas are more frequently used by bats. Considering that bats are important consumers of herbivorous insects, including agricultural pest, this is important for sustainable land management. Bat activity and species richness were assessed using repeated monitoring from May to September in 2010 with acoustic monitoring surveys on 50 grassland sites in the Biosphere Reserve Schorfheide-Chorin (North-East Germany. Using spatial analysis (GIS, we measured the closest distance of each grassland site to potentially connecting landscape elements (e.g., trees, linear vegetation, groves, running and standing water. In addition, we assessed the distance to and the percent land cover of forest remnants and urban areas in a 200 m buffer around the recording sites to address differences in the local landscape setting. Species richness and bat activity increased significantly with higher forest land cover in the 200 m buffer and at smaller distance to forested areas. Moreover, species richness increased in proximity to tree groves. Larger amount of forest land cover and smaller distance to forest also resulted in a higher activity of bats on grassland sites in the beginning of the year during May, June and July. Landscape elements near grassland sites also influenced species composition of bats and species richness of functional groups (open, edge and narrow space foragers. Our results highlight the importance of forested areas, and suggest that agricultural grasslands that are closer to forest remnants might be better buffered against outbreaks of agricultural pest insects due to higher species richness and higher bat activity. Furthermore, our data reveals that even for highly mobile species such as bats, a very dense network of connecting elements within the

  16. The Importance of Landscape Elements for Bat Activity and Species Richness in Agricultural Areas.

    Heim, Olga; Treitler, Julia T; Tschapka, Marco; Knörnschild, Mirjam; Jung, Kirsten

    2015-01-01

    Landscape heterogeneity is regarded as a key factor for maintaining biodiversity and ecosystem function in production landscapes. We investigated whether grassland sites at close vicinity to forested areas are more frequently used by bats. Considering that bats are important consumers of herbivorous insects, including agricultural pest, this is important for sustainable land management. Bat activity and species richness were assessed using repeated monitoring from May to September in 2010 with acoustic monitoring surveys on 50 grassland sites in the Biosphere Reserve Schorfheide-Chorin (North-East Germany). Using spatial analysis (GIS), we measured the closest distance of each grassland site to potentially connecting landscape elements (e.g., trees, linear vegetation, groves, running and standing water). In addition, we assessed the distance to and the percent land cover of forest remnants and urban areas in a 200 m buffer around the recording sites to address differences in the local landscape setting. Species richness and bat activity increased significantly with higher forest land cover in the 200 m buffer and at smaller distance to forested areas. Moreover, species richness increased in proximity to tree groves. Larger amount of forest land cover and smaller distance to forest also resulted in a higher activity of bats on grassland sites in the beginning of the year during May, June and July. Landscape elements near grassland sites also influenced species composition of bats and species richness of functional groups (open, edge and narrow space foragers). Our results highlight the importance of forested areas, and suggest that agricultural grasslands that are closer to forest remnants might be better buffered against outbreaks of agricultural pest insects due to higher species richness and higher bat activity. Furthermore, our data reveals that even for highly mobile species such as bats, a very dense network of connecting elements within the landscape is

  17. Observation of new spontaneous fission activities from elements 100 to 105

    Somerville, L.P.

    1982-03-01

    Several new Spontaneous Fission (SF) activities have been found. No definite identification could be made for any of the new SF activities; however, half-lives and possible assignments to element-104 isotopes consistent with several cross bombardments include /sup 257/Rf(3.8 s, 14% SF), /sup 258/Rf(13 ms), /sup 259/Rf(approx. 3 s, 8% SF), /sup 260/Rf(approx. 20 ms), and /sup 262/Rf(approx. 50 ms). The 80-ms SF activity claimed by the Dubna group for the discovery of element 104 (/sup 260/104) was not observed. A difficulty exists in the interpretation that /sup 260/Rf is a approx. 20-ms SF activity: in order to be correct, for example, the SF activities with half-lives between 14 and 24 ms produced in the reactions 109- to 119-MeV /sup 18/O + /sup 248/Cm, 88- to 100-MeV /sup 15/N + /sup 249/Bk, and 96-MeV /sup 18/O + /sup 249/Cf must be other nuclides due to their large production cross sections, or the cross sections for production of /sup 260/Rf must be enhanced by unknown mechanisms. Based on calculated total production cross sections a possible approx. 1% electron-capture branch in /sup 258/Lr(4.5 s) to the SF emitter /sup 258/No(1.2 ms) and an upper limit of 0.05% for SF branching in /sup 254/No(55 s) were determined. Other measured half-lives from unknown nuclides produced in respective reactions include approx. 1.6 s (/sup 18/O + /sup 248/CM), indications of a approx. 47-s SF activity (75-MeV /sup 12/C + /sup 249/Cf), and two or more SF activities with 3 s less than or equal to T/sub 1/2/ less than or equal to 60 s (/sup 18/O + /sup 249/Bk). The most exciting conclusion of this work is that if the tentative assignments to even-even element 104 isotopes are correct, there would be a sudden change in the SF half-life systematics at element 104 which has been predicted theoretically and attributed to the disappearance of the second hump of the double-humped fission barrier.

  18. Effect of heat treatment on anodic activation of aluminium by trace element indium

    Graver, Brit [Department of Materials Science and Engineering, Norwegian University of Science and Technology, N-7491 Trondheim (Norway); Helvoort, Antonius T.J. van [Department of Physics, Norwegian University of Science and Technology, N-7491 Trondheim (Norway); Nisancioglu, Kemal, E-mail: kemal.nisancioglu@material.ntnu.n [Department of Materials Science and Engineering, Norwegian University of Science and Technology, N-7491 Trondheim (Norway)

    2010-11-15

    Research highlights: {yields} Indium segregation activates AlIn alloy surface anodically in chloride solution. {yields} Enrichment of In on Al surface can occur thermally by heat treatment at 300 {sup o}C. {yields} Increasing temperature homogenises indium in aluminium reducing anodic activation. {yields} Indium can activate AlIn surface by segregating through dealloying of aluminium. {yields} Anodic activation is caused by AlIn amalgam formation at aluminium surface. - Abstract: The presence of trace elements in Group IIIA-VA is known to activate aluminium anodically in chloride environment. The purpose of this paper is to investigate the surface segregation of trace element In by heat treatment and resulting surface activation. Model binary AlIn alloys, containing 20 and 1000 ppm by weight of In, were characterized after heat treatment at various temperatures by use of glow discharge optical emission spectroscopy, electron microscopy and electrochemical polarization. Heat treatment for 1 h at 300 {sup o}C gave significant segregation of discrete In particles (thermal segregation), which activated the surface. Indium in solid solution with aluminium, obtained by 1 h heat treatment at 600 {sup o}C, also activated by surface segregation of In on alloy containing 1000 ppm In, resulting from the selective dissolution of the aluminium component during anodic oxidation (anodic segregation). The effect of anodic segregation was reduced by decreasing indium concentration in solid solution; it had negligible effect at the 20 ppm level. The segregated particles were thought to form a liquid phase alloy with aluminium during anodic polarization, which in turn, together with the chloride in the solution destabilized the oxide.

  19. Prompt gamma neutron activation analysis of toxic elements in radioactive waste packages.

    Ma, J-L; Carasco, C; Perot, B; Mauerhofer, E; Kettler, J; Havenith, A

    2012-07-01

    The French Alternative Energies and Atomic Energy Commission (CEA) and National Radioactive Waste Management Agency (ANDRA) are conducting an R&D program to improve the characterization of long-lived and medium activity (LL-MA) radioactive waste packages. In particular, the amount of toxic elements present in radioactive waste packages must be assessed before they can be accepted in repository facilities in order to avoid pollution of underground water reserves. To this aim, the Nuclear Measurement Laboratory of CEA-Cadarache has started to study the performances of Prompt Gamma Neutron Activation Analysis (PGNAA) for elements showing large capture cross sections such as mercury, cadmium, boron, and chromium. This paper reports a comparison between Monte Carlo calculations performed with the MCNPX computer code using the ENDF/B-VII.0 library and experimental gamma rays measured in the REGAIN PGNAA cell with small samples of nickel, lead, cadmium, arsenic, antimony, chromium, magnesium, zinc, boron, and lithium to verify the validity of a numerical model and gamma-ray production data. The measurement of a ∼20kg test sample of concrete containing toxic elements has also been performed, in collaboration with Forschungszentrum Jülich, to validate the model in view of future performance studies for dense and large LL-MA waste packages. PMID:22406218

  20. Soil pollution with trace elements at selected sites in Romania studied by instrumental neutron activation analysis

    Pantelica, A. [Horia Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH), Magurele, Ilfov County (Romania); Carmo Freitas, M. do [Technological and Nuclear Institute (ITN), Sacavem (Portugal); Ene, A. [Dunarea de Jos Univ. of Galati (Romania). Dept. of Chemistry, Physics and Environment; Steinnes, E. [Norwegian Univ. of Science and Technology, Trondheim (Norway). Dept. of Chemistry

    2013-03-01

    Instrumental neutron activation analysis (INAA) was used to determine concentrations of 42 elements in samples of surface soil collected at seven sites polluted from various anthropogenic activities and a control site in a relatively clean area. Elements studied were Ag, Al, As, Au, Ba, Br, Ca, Cd, Ce, Co, Cr, Cs, Eu, Fe, Gd, Hf, Hg, K, La, Lu, Mg, Mn, Mo, Na, Nd, Ni, Rb, Sb, Sc, Se, Sm, Sr, Ta, Tb, Th, Ti, U, V, W, Yb, Zn, and Zr. The results are compared with data for trace elements atmospheric deposition in lichen transplants from the same sites. The most severe soil contamination was observed at Copsa Mica from non-ferrous metallurgy. Appreciable soil contamination was also indicated at Baia Mare (non-ferrous mining and metallurgy), Deva (coal-fired power plant, cement and building materials industry), Galati (ferrous metallurgy), Magurele and Afumati (general urban pollution), and Oradea (chemical and light industries). In most cases excessive levels of toxic metals in soils matched correspondingly high values in lichen transplants. Compared to Romanian norms, legal upper limits were exceeded for Zn and Cd at Copsa Mica. Also, As and Sb occurred in excessive levels at given sites. (orig.)

  1. Soil pollution with trace elements at selected sites in Romania studied by instrumental neutron activation analysis

    Instrumental neutron activation analysis (INAA) was used to determine concentrations of 42 elements in samples of surface soil collected at seven sites polluted from various anthropogenic activities and a control site in a relatively clean area. Elements studied were Ag, Al, As, Au, Ba, Br, Ca, Cd, Ce, Co, Cr, Cs, Eu, Fe, Gd, Hf, Hg, K, La, Lu, Mg, Mn, Mo, Na, Nd, Ni, Rb, Sb, Sc, Se, Sm, Sr, Ta, Tb, Th, Ti, U, V, W, Yb, Zn, and Zr. The results are compared with data for trace elements atmospheric deposition in lichen transplants from the same sites. The most severe soil contamination was observed at Copsa Mica from non-ferrous metallurgy. Appreciable soil contamination was also indicated at Baia Mare (non-ferrous mining and metallurgy), Deva (coal-fired power plant, cement and building materials industry), Galati (ferrous metallurgy), Magurele and Afumati (general urban pollution), and Oradea (chemical and light industries). In most cases excessive levels of toxic metals in soils matched correspondingly high values in lichen transplants. Compared to Romanian norms, legal upper limits were exceeded for Zn and Cd at Copsa Mica. Also, As and Sb occurred in excessive levels at given sites. (orig.)

  2. Speed of sound estimation with active PZT element for thermal monitoring during ablation therapy: feasibility study

    Kim, Younsu; Guo, Xiaoyu; Cheng, Alexis; Boctor, Emad M.

    2016-04-01

    Controlling the thermal dose during ablation therapy is instrumental to successfully removing the tumor while preserving the surrounding healthy tissue. In the practical scenario, surgeons must be able to determine the ablation completeness in the tumor region. Various methods have been proposed to monitor it, one of which uses ultrasound since it is a common intraoperative imaging modality due to its non-invasive, cost-effective, and convenient natures. In our approach, we propose to use time of flight (ToF) information to estimate speed of sound changes. Accurate speed of sound estimation is crucial because it is directly correlated with temperature change and subsequent determination of ablation completeness. We divide the region of interest in a circular fashion with a variable radius from the ablator tip. We introduce the concept of effective speed of sound in each of the sub-regions. Our active PZT element control system facilitates this unique approach by allowing us to acquire one-way ToF information between the PZT element and each of the ultrasound elements. We performed a simulation and an experiment to verify feasibility of this method. The simulation result showed that we could compute the effective speed of sound within 0.02m/s error in our discrete model. We also perform a sensitivity analysis for this model. Most of the experimental results had less than 1% error. Simulation using a Gaussian continuous model with multiple PZT elements is also demonstrated. We simulate the effect of the element location one the optimization result.

  3. Measurements of 27 elements in garden and lawn fertilizers using instrumental neutron activation analysis

    Five locally available garden and lawn fertilizers were analyzed for elemental content using instrumental neutron activation analysis. The fertilizers were labeled as High Yield; Slow Release, 13-13-13; 16-8-4 and 28-4-4. The concentration ranges of the elements measured, in μg/g, were: Ba < 10-105; Br 0.55-272; Co 0.33-3.74; Cr 10.0-42.5; Cs 0.09-1.02; Eu 0.05-0.42; Fe 1840-9830; Ga < 1-4.6; Ge < 0.1-1.23; Hf 0.07-2.32; La 1.66-10.4; Na 57.6-3990; Nd < 9; Ni < 3-12.3; Rb 2.42-48.5; Sb 0.03-0.24; Sc 0.3-3.11; Se 2.68-10.2; Sm < 0.4-2.13; Sr 21.7-214; Ta < 0.01-0.052; Tb 0.05-0.28; Th 0.52-2.16; U 0.18-0.38; Zn 10.8-233 and Zr < 1-8.95. Some of these elements are recognized as micronutritiens (e.g., Fe and (Zn), and are necessary for plant growth. However, other elements may lead to undesirable environmental effects. The undiscriminating use of fertilizers, especially in home gardening, may result in the increase of toxic elements (Co, Cr, Se, Sb, Tb, U etc.) in the underground water supply. (author) 6 refs.; 1 tab

  4. Elemental characterization of bread and durum wheat by instrumental neutron activation analysis

    Cereals are by far the most significant agricultural crops, not only due to the sheer amount of their gross-tonnage production and prevalence in human diets worldwide, but also as food vehicles of important items for human nutrition and wellness at large-proteins, dietary fibers and oligoelements, such as selenium, calcium, zinc and iron, to name just a few. Still, some micronutrients feature an uneven distribution in the upper continental crust, and thus in cultivation soils deriving therefrom. Whether soils have always been poor in an essential element, or have just become deprived of it by intensive farming, the result is the same: insufficient soil-plant transfer, feeble-to-nonexistent plant uptake, and, therefore, unsatisfactory dietary distribution of that element through the food chain. Countries that implemented corrective measures or programs of crop biofortification and consumer education have been successful in dealing with some micronutrients' deficiencies. Given their relative weight in Portuguese diets, cereals are obvious candidates for crop-supplementation strategies that may contribute to an upgrade in the health status of the whole population. A good knowledge of element-baseline data for major cereal varieties (plants) and main production areas (soils) is a pre-requisite though. The present work was aimed at an elemental characterization of cereals and soils from relevant wheat-producing areas of mainland Portugal. This paper is focused on wheat samples-bread and durum wheats; Triticum aestivum L. (Farak and Jordao cultivars) and Triticum durum Desf. (Don Duro and Simeto cultivars), respectively-from the 2009 campaign, collected at Tras-os-Montes, Alto Alentejo and Baixo Alentejo (inland regions). Elemental concentrations were determined by instrumental neutron activation analysis (INAA; k0-variant), and assessed with the k0-IAEA software. Quality control was asserted through the analysis of NIST-SRMR 1567a (Wheat Flour), NIST-SRMR 1568a (Rice

  5. Analytic determination of the activation of essential and toxic trace elements in biological material

    A neutron activation-analysis technique for the multielement determination in biological material was developed. The individual steps of this procedure comprise radiochemical and also instrumental analytic techniques. After radiochemical separation 34 elements can be determined, after only instrumental procedures 26 elements can be detected in biological material. The radiochemical analysis of 34 elements lasts 4 days. Tracer investigations on the radionuclide retention of the anorganic separators HAP, TiP and ZP in 9N aqueous HNO3 solution indicated that apart from Na-24, K-42 and P-32 the radionuclides Cs-134, Rb-86 and Se-75 are almost quantitatively adsorbed at the separators. For the remaining investigated radionuclides different but well-reproducible retention values resulted. The pH-value only slightly influences the extent of the radionuclide retention. Kinetic investigations on the radiochemical precipitation of some radionuclides on Cu and Cu(Hg)sub(x) were carried out. The depositing of the radionuclides Ag-110m, Hg-203 and Se-75 at 00C and room temperature on Cu(Hg)sub(x) and Cu foil is a first order reaction. The half-life periods and the velocity constants of the depositing on Cu and Cu(Hg)sub(x) were determined for the investigated radionuclides in dependency of the temperature. The technique was examined by means of international biological multielement standards of known element combinations. The realisation of ring tests for the multielement determination in potatoe and milk powder showed that this method provides precise results. The applicability of the radiochemical method was confirmed by the simultaneous determination of 25 elements in overall nutrition samples. The instrumental technique was applied for the multielement determination in human hair (of the head) and in river water. (orig./MG)

  6. Determination of rare earth elements in Taiwan monazite by chemical neutron activation analysis

    Taiwan monazite is a unique mineral obtained from the heavy sand found in the river floor of Tzuo-suei river and En-suei river. Both rivers are flowing parallel with separated narrow area into the sea at southwestern coast of Taiwan. The characteristic of monazite is that it contains considerable rare earth elements (REEs). REEs are considered very useful elements in the local industries and scientific researches such as ceramic, semiconductors, and glass optics. In this study, chemical neutron activation analysis (CNAA) was used to determine the contents of REEs in Taiwan monazite. A few milligram of monazite was digested in the microwave oven for 25 minutes with mixed acid (conc. HNO3 and HClO4). REEs were preconcentrated by hydrated magnesium oxide and CNAA was performed. (author)

  7. Trace element determinations in lungs of rats by neutron activation analysis

    Saiki, Mitiko [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil); Saldiva, Paulo H.N. [Sao Paulo Univ., SP (Brazil). Faculdade de Medicina

    1995-12-31

    In this paper neutron activation analysis was applied to the trace element determinations in lungs of rats housed in regions with different levels of pollution. Lung samples were previously submitted to cryogenic homogenization, freeze drying and sterilization and they were irradiated with together the standards of elements under a thermal neutron flux of 10{sup 11} -10{sup 13} n.cm{sup -2}.s{sup -1} in the IEA-R1 nuclear reactor. Concentrations for Br, Ca, Cl, Cs, Fe, K, Mg, Mn, Na, Rb, Sb, Sc, Se and Zn were determined, in general, with a good precision. In order to evaluate the accuracy of the method, the NIST 1577 a Bovine Liver and IUPAC Bowens`s Kale reference materials were analyzed. Comparison among the results obtained for samples of rats originated from different regions was also performed. (author). 3 refs., 2 tabs.

  8. Trace element determinations in lungs of rats by neutron activation analysis

    In this paper neutron activation analysis was applied to the trace element determinations in lungs of rats housed in regions with different levels of pollution. Lung samples were previously submitted to cryogenic homogenization, freeze drying and sterilization and they were irradiated with together the standards of elements under a thermal neutron flux of 1011 -1013 n.cm-2.s-1 in the IEA-R1 nuclear reactor. Concentrations for Br, Ca, Cl, Cs, Fe, K, Mg, Mn, Na, Rb, Sb, Sc, Se and Zn were determined, in general, with a good precision. In order to evaluate the accuracy of the method, the NIST 1577 a Bovine Liver and IUPAC Bowens's Kale reference materials were analyzed. Comparison among the results obtained for samples of rats originated from different regions was also performed. (author). 3 refs., 2 tabs

  9. Determination of short-lived trace elements in environmental samples by neutron activation analysis

    Concentration of a short-lived trace elements in environmental samples were determined by neutron activation analysis, a counting loss often occur due to the high counting rate. A Pile-Up Rejecter (PUR) electric circuit was installed in counting a short-lived trace elements by a γ-ray spectrometer in order to correct a counting loss. The samples were irradiated for 30∼60 seconds at neutron flux of 3.5 x 1012n.cm-2.s-1, then the samples cooled for 120 second and counted for 180 second using this system. The nuclides concentration in the varieties environmental samples have a difference analysis result, was more accurate and precise, which the measured result would be 30 % more higher by PUR system than the result would be counted using a conventional γ-ray spectrometry method

  10. Determination of trace elements in acid rain by reversed-phase extraction chromatography and neutron activation

    A preconcentration neutron activation analysis (PNAA) method involving reversed-phase extraction chromatography on 8-hydroxyquinoline-loaded Amberlite XAD-2 resin has been developed for the simultaneous determination of selected trace elements in acid rain and natural water samples. Quantitative retention has been achieved for Co, Cu, Hg, V and Zn at pH 6.0 and for Cd at pH 7.0. Various factors that can influence the preconcentration procedure have been studied in detail. Concentrations of the elements have been determined by the direct irradiation of the resin without eluting them from the column. Both precision and accuracy of the PNAA method are very good. The detection limits vary between 0.01 and 3 ppb. (author) 48 refs.; 2 figs.; 4 tabs

  11. Characterization of trace elements in Casearia medicinal plant by neutron activation analysis

    Leaves of Casearia sylvestris, Casearia decandra and Casearia obliqua plant species, collected at the Atlantic Forest in Brazil, were analyzed by using instrumental neutron activation analysis (INAA). Short and long irradiations using thermal neutron flux of the IEA-R1 nuclear reactor were carried out for these analyses. Concentrations of Ca, K and Mg were found in these samples at the percentage levels, Br, Cl, Fe, Mn, Na, Rb and Zn at the μg g-1 levels and Co, Cr, Cs, La, and Sc at the μg kg-1 levels. Comparisons were made among the element concentrations obtained in these three Casearia species and significant differences were found for the elements Cl, Co, Cs, Cr, La, Mn, Na and Sc. The precision and the accuracy of the results were evaluated by analyzing the certified reference materials NIST-1515 Apple Leaves and NIST-1573a Tomato Leaves

  12. The level of elements and antioxidant activity of commercial dietary supplement formulations based on edible mushrooms.

    Stilinović, Nebojša; Škrbić, Biljana; Živančev, Jelena; Mrmoš, Nataša; Pavlović, Nebojša; Vukmirović, Saša

    2014-12-01

    Commercial preparations of Cordyceps sinensis, Ganoderma lucidum and Coprinus comatus mushroom marketed as healthy food supplements in Serbia were analyzed by atomic absorption spectrometry with a graphite furnace (GFAAS) for their element content. Antioxidant activity potential and total phenolics of the same mushrooms were determined. The element content of mushroom samples was in the range of 0.130-0.360 mg kg(-1) for lead (Pb), sinensis showed the best properties. The same was seen for the analysis of selected phenolic compounds; C. sinensis was found to have the highest content. Commercial preparations of C. sinensis and C. comatus can be considered to be safe and suitable food supplements included in well-balanced diets. PMID:25294630

  13. Separation of interfering elements in the neutron activation analysis of lanthanides in geological materials

    A chemical procedure has been developed for the separation of U, Th, Fe, Sc, Na,Ta, and Mo which interfere in the neutron activation analysis of the lanthanide elements in geological materials. This procedure is based on the solvent extraction of interferents using a solution of tetracycline in benzyl alcohol. The lanthanide elements remaining in the aqueous phase are coprecipitated on calcium oxalate or ferric hydroxide for irradiation and subsequent determination by gamma ray spectrometry. The chemical separation procedure was applied in the analysis of lanthanides in two international geological reference materials GSP-1 (USGS), GS-N (CRPG) and in the analysis of a volcanic rock from Pocos de Caldas, MG, Brazil. The sensitivities for all the lanthanides were determined. (author)

  14. Trace element pharmacognostical study on diuretic drugs by neutron activation analysis

    Some pharmacological properties and especially diuretic action of medicinal plants are attributed to their elemental content. The elements chlorine, manganese, potassium and sodium are determined by instrumental neutron activation analysis in the dry samples of the following drugs: stigmata of Zea mays, leaves of Uva ursi, rhizome of Cynodon dactylon, whole plant of Ceterach officinarum as well as in infusions, decoction of the same drugs and in the water used for these preparations. It has been found that manganese and potassium are transferred partially into prepared solutions. Sodium is not transferred into solutions from any of these drugs while only chlorine is transferred partially into infusion of Zea mays. From these results it is concluded that the diuretic action of the examined drugs should not be attributed exclusively to the presence of their potassium and chlorine content but also to other constituents. (author)

  15. Analysis of toxic trace elements in sea food samples by neutron activation

    The contents of toxic and essential trace element were analysed such as As, Hg, Se and Zn by neutron activation analysis in coastal fishes consumed by the general population of Malaysia. The mean values of the elements analysed expressed in mg/kg fresh weight ranged 1.42-5.61, 0.06-0.42, 4.2-20.6, 0.41-1.28 for As, Hg, Zn and Se, respectively. The maximum permissible limit for As in food was set at 1.0 mg/kg under the Malaysian Food Regulations. The results showed that consumption of coastal fishes is not permitted under the regulations, while the levels of Hg, Se and Zn were within the permissible limits. The daily dietary intake of As and Hg at 400 μg and 30 μg respectively are still within the tolerance levels. (author) 9 refs.; 2 tabs

  16. Assessment of some chemical element contents in Traganum nudatum Del shrub using instrumental neutron activation analysis

    Bouzid Nedjimi; Brahim Beladel

    2015-01-01

    Instrumental neutron activation analysis (INAA) has been used to determine some chemical element contents (K, Ca, Na, Fe, Zn, Co, Eu, Sb, and Sc) in Traganum nudatum Del (Chenopodiaceae family) consumed in North African rangelands by sheep livestock. Samples were collected from the area of Djelfa in an arid steppe of Algeria. Results show that pasture halophyte had sufficient levels of K, Ca, Zn, and Co to meet the requirements of ruminants. However, it seems that this halophyte shrub had substantial amounts of Na, higher than the critical level established by the National Research Council (NRC). Eu, Sb, and Sc were within the safety baseline of all the assayed elements recommended by the NRC. The high Na content (∼10 g/kg) in this halophytic species requires elevated intake of water by livestock.

  17. Use of the low-background underground laboratory in activation analysis of pure substances and low-activity radiometry of naturally radioactive elements

    This paper is the result of joint investigations by Russian and German scientists. It is devoted to questions of lowering the detection limits of some elements in neutron-activation analysis of pure substances (for example, silicon) in the low-background underground laboratory. The authors also consider the prospects for radiometry of some naturally radioactive elements under the same conditions of activity measurements

  18. Finite Element Based Solution of Laplace's Equation Applied to Electrical Activity of the Human Body

    Zainab T. Baqer

    2010-01-01

    Full Text Available Computer models are used in the study of electrocardiography to provide insight into physiological phenomena that are difficult to measure in the lab or in a clinical environment. The electrocardiogram is an important tool for the clinician in that it changes characteristically in a number of pathological conditions. Many illnesses can be detected by this measurement. By simulating the electrical activity of the heart one obtains a quantitative relationship between the electrocardiogram and different anomalies. Because of the inhomogeneous fibrous structure of the heart and the irregular geometries of the body, finite element method is used for studying the electrical properties of the heart. This work describes the implementation of the Conjugate Gradient iterative method for the solution of large linear equation systems resulting from the finite element method. A diagonal Jacobi preconditioner is used in order to accelerate the convergence. Gaussian elimination is also implemented and compared with the Precondition Conjugate Gradient (PCG method and with the iterative method. Different types of matrix storage schemes are implemented such as the Compressed Sparse Row (CSR to achieve better performance. In order to demonstrate the validity of the finite element analysis, the technique is adopted to solve Laplace's equation that describes the electrical activity of the human body with Dirichlet and Neumann boundary conditions. An automatic mesh generator is built using C++ programming language. Initially a complete finite element program is built to solve Laplace's equation. The same accuracy is obtained using these methods. The results show that the CSR format reduces computation time compared to the order format. The PCG method is better for the solution of large linear system (sparse matrices than the Gaussian Elimination and back substitution method, while Gaussian elimination is better than iterative method.

  19. Trace element landscape of resting and activated human neutrophils on the sub-micrometer level.

    Niemiec, M J; De Samber, B; Garrevoet, J; Vergucht, E; Vekemans, B; De Rycke, R; Björn, E; Sandblad, L; Wellenreuther, G; Falkenberg, G; Cloetens, P; Vincze, L; Urban, C F

    2015-06-01

    Every infection is a battle for trace elements. Neutrophils migrate first to the infection site and accumulate quickly to high numbers. They fight pathogens by phagocytosis and intracellular toxication. Additionally, neutrophils form neutrophil extracellular traps (NETs) to inhibit extracellular microbes. Yet, neutrophil trace element characteristics are largely unexplored. We investigated unstimulated and phorbol myristate acetate-stimulated neutrophils using synchrotron radiation X-ray fluorescence (SR-XRF) on the sub-micron spatial resolution level. PMA activates pinocytosis, cytoskeletal rearrangements and the release of NETs, all mechanisms deployed by neutrophils to combat infection. By analyzing Zn, Fe, Cu, Mn, P, S, and Ca, not only the nucleus but also vesicular granules were identifiable in the elemental maps. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) revealed a neutrophil-specific composition of Zn, Fe, Cu, and Mn in comparison with J774 and HeLa cells, indicating a neutrophil-specific metallome complying with their designated functions. When investigating PMA-activated neutrophils, the SR-XRF analysis depicted typical subcellular morphological changes: the transformation of nucleus and granules and the emergence of void vacuoles. Mature NETs were evenly composed of Fe, P, S, and Ca with occasional hot spots containing Zn, Fe, and Ca. An ICP-MS-based quantification of NET supernatants revealed a NETosis-induced decrease of soluble Zn, whereas Fe, Cu, and Mn concentrations were only slightly affected. In summary, we present a combination of SR-XRF and ICP-MS as a powerful tool to analyze trace elements in human neutrophils. The approach will be applicable and valuable to numerous aspects of nutritional immunity. PMID:25832493

  20. Neutron activation analysis of essential and toxic elements in sludge from city water treatment

    Instrumental neutron activation analysis (INAA) method was used to determine concentrations of essential and toxic elements in three sludge samples resulting after the city water treatment. The samples, having different levels of toxic elements, were denoted as WT-L (low level), WT-M (medium level) and WT-H (high level). They were provided by the Institute of Radioecology and Applied Nuclear Techniques from Kosice (Slovakia), in the frame of an intercomparison exercise. A number of 36 laboratories from 13 countries have participated to this intercomparison run. Our laboratory data are presented, with respect to the intercomparison values, to emphasize the analytical performances obtained by INAA at WWR-S reactor in Bucharest. Concentrations of 38 elements (Ag, Al, As, Au, Ba, Br, Ca, Ce, Cl, Co, Cr, Cs, Cu, Eu, Fe, Hf, Hg, K, La, Lu, Mn, Na, Ni, Rb, Sb, Sc, Se, Sm, Sr, Ta, Tb, Th, Ti, U, V, W, Yb, Zn) were determined by us using INAA method. Short irradiation of 30 s at 2.5 · 1012 n · cm2 · s-1neutron fluence rate using a pneumatic tube, and long irradiation of 65 h at 1.1 · 1011 n · cm2 · s-1 neutron fluence rate, were performed. The gamma ray spectra were carried out by means of a HPGe EG/G ORTEC detector with 2.1 keV FWHM and 30 % relative efficiency, and processed by ASPERA program. The concentration values in the three types of sludge samples are found between percent for Al, Ca and Fe and hundreds of μg kg-1 for Au, Eu, Lu, Ta, Tb. By comparing the elemental contents of the WT-H and WT-L samples, the following approximate ratios were determined: 50 for Co, 20 for Cu, 18 for Cl, 15 for Cr, 14 for As, 8.5 for Mn, 7.5 for Hg, 4.8 for Zn. All the elemental concentrations obtained in our laboratory have been included in the statistical processing of the results submitted by the participating laboratories. We have obtained a very good agreement for Al, As, Ba, Ca, Cl, Co, Cs, Eu, Fe, Hf, La, Mn, Na, Sc, Sm, Sr, Th, U, Zn and a good agreement for the other

  1. Trace elements in some new Romanian phytotherapeutic drugs determined by neutron activation analysis

    Instrumental neutron activation analysis (INAA) has been performed on four new Romanian phytotherapeutic drugs registered us Fitolip, Fitodiab, Retinomion and Neuromion. The drugs were very well tolerated in clinical trials and are used in diabetes and other chronic diseases. They were prepared in the form of tablets made from dried powders of fruits, flowers, leaves and shells of plants used in non-conventional medicine. All four products are reach in various bioactive substances such as flavones, flavonoids, anthocyans, terpenes, rutosides, vitamins and essential fatty acids. Samples and multielemental reference materials were irradiated in a thermal neutron flux of 1.1 x 1011 n.cm-2.s-1 and measured with a high resolution Ge(Li) detector. 28 mineral elements were found, including Mg, K, Ca, Na and Fe at percent and sub-percent levels; Cl, Al and Mn between tens and thousands of ppm; Zn, Br, Rb and Ba up to tens of ppm; Cr, Cu, Co and V in the ppm range; and Sc, As, Sb, Cs, Lu, La, Ce, Sm, Hf, Au, Hg and Th up to hundreds of ppb. The intake of mineral elements provided by a cure of 3 pills/day shows the following: 1. None of the toxic elements As and Hg in the four drugs exceeds a noxious level; 2. Mg is the most abundant macro-element and a cure covers 15 - 60 % of the daily requirements; 3. Among essential microelements, Co may provide even more than 100% of the daily requirements; other elements may give small but significant fractions of the necessary daily amounts, e.g. 3-30% for Cr, 5-20% for Mn, and 2-10% for Fe; 4. The supply of Al, the most abundant unessential metal represents 6 - 40 % of the known daily intake. Thus a 3 pills/day cure could contribute positively to the therapy of various diseases by providing Mg, Mn, Cr (a trace element deficient in diabetes), Fe and Co, but higher daily doses could result in a Co oversupply. Further in INAA studies on biological examples from patients taking these new medicines are needed to understand the

  2. Innovative Application of Mechanical Activation for Rare Earth Elements Recovering: Process Optimization and Mechanism Exploration

    Tan, Quanyin; Deng, Chao; Li, Jinhui

    2016-01-01

    With the rapidly expanding use of fluorescent lamps (FLs) and increasing interest in conservation and sustainable utilization of critical metals such as rare earth elements (REEs), the recovering of REEs from phosphors in waste FLs is becoming a critical environmental and economic issue. To effectively recycle REEs with metallurgical methods, mechanical activation by ball milling was introduced to pretreat the waste phosphors. This current study put the emphasis on the mechanical activation and leaching processes for REEs, and explored the feasibility of the method from both theoretical and practical standpoints. Results showed physicochemical changes of structural destruction and particle size reduction after mechanical activation, leading to the easy dissolution of REEs in the activated samples. Under optimal conditions, dissolution yields of 89.4%, 93.1% and 94.6% for Tb, Eu and Y, respectively, were achieved from activated waste phosphors using hydrochloric acid as the dissolution agent. The shrinking core model proved to be the most applicable for the leaching procedure, with an apparent activation energy of 10.96 ± 2.79 kJ/mol. This novel process indicates that mechanical activation is an efficient method for recovering REEs from waste phosphors, and it has promising potential for REE recovery with low cost and high efficiency.

  3. Structural elements in the Girk1 subunit that potentiate G protein-gated potassium channel activity.

    Wydeven, Nicole; Young, Daniele; Mirkovic, Kelsey; Wickman, Kevin

    2012-12-26

    G protein-gated inwardly rectifying K(+) (Girk/K(IR)3) channels mediate the inhibitory effect of many neurotransmitters on excitable cells. Girk channels are tetramers consisting of various combinations of four mammalian Girk subunits (Girk1 to -4). Although Girk1 is unable to form functional homomeric channels, its presence in cardiac and neuronal channel complexes correlates with robust channel activity. This study sought to better understand the potentiating influence of Girk1, using the GABA(B) receptor and Girk1/Girk2 heteromer as a model system. Girk1 did not increase the protein levels or alter the trafficking of Girk2-containing channels to the cell surface in transfected cells or hippocampal neurons, indicating that its potentiating influence involves enhancement of channel activity. Structural elements in both the distal carboxyl-terminal domain and channel core were identified as key determinants of robust channel activity. In the distal carboxyl-terminal domain, residue Q404 was identified as a key determinant of receptor-induced channel activity. In the Girk1 core, three unique residues in the pore (P) loop (F137, A142, Y150) were identified as a collective potentiating influence on both receptor-dependent and receptor-independent channel activity, exerting their influence, at least in part, by enhancing mean open time and single-channel conductance. Interestingly, the potentiating influence of the Girk1 P-loop is tempered by residue F162 in the second membrane-spanning domain. Thus, discontinuous and sometime opposing elements in Girk1 underlie the Girk1-dependent potentiation of receptor-dependent and receptor-independent heteromeric channel activity. PMID:23236146

  4. Transcription of Mammalian cis-Regulatory Elements Is Restrained by Actively Enforced Early Termination.

    Austenaa, Liv M I; Barozzi, Iros; Simonatto, Marta; Masella, Silvia; Della Chiara, Giulia; Ghisletti, Serena; Curina, Alessia; de Wit, Elzo; Bouwman, Britta A M; de Pretis, Stefano; Piccolo, Viviana; Termanini, Alberto; Prosperini, Elena; Pelizzola, Mattia; de Laat, Wouter; Natoli, Gioacchino

    2015-11-01

    Upon recruitment to active enhancers and promoters, RNA polymerase II (Pol II) generates short non-coding transcripts of unclear function. The mechanisms that control the length and the amount of ncRNAs generated by cis-regulatory elements are largely unknown. Here, we show that the adaptor protein WDR82 and its associated complexes actively limit such non-coding transcription. WDR82 targets the SET1 H3K4 methyltransferases and the nuclear protein phosphatase 1 (PP1) complexes to the initiating Pol II. WDR82 and PP1 also interact with components of the transcriptional termination and RNA processing machineries. Depletion of WDR82, SET1, or the PP1 subunit required for its nuclear import caused distinct but overlapping transcription termination defects at highly expressed genes and active enhancers and promoters, thus enabling the increased synthesis of unusually long ncRNAs. These data indicate that transcription initiated from cis-regulatory elements is tightly coordinated with termination mechanisms that impose the synthesis of short RNAs. PMID:26593720

  5. Glucose Enhances Basal or Melanocortin-Induced cAMP-Response Element Activity in Hypothalamic Cells.

    Breit, Andreas; Wicht, Kristina; Boekhoff, Ingrid; Glas, Evi; Lauffer, Lisa; Mückter, Harald; Gudermann, Thomas

    2016-07-01

    Melanocyte-stimulating hormone (MSH)-induced activation of the cAMP-response element (CRE) via the CRE-binding protein in hypothalamic cells promotes expression of TRH and thereby restricts food intake and increases energy expenditure. Glucose also induces central anorexigenic effects by acting on hypothalamic neurons, but the underlying mechanisms are not completely understood. It has been proposed that glucose activates the CRE-binding protein-regulated transcriptional coactivator 2 (CRTC-2) in hypothalamic neurons by inhibition of AMP-activated protein kinases (AMPKs), but whether glucose directly affects hypothalamic CRE activity has not yet been shown. Hence, we dissected effects of glucose on basal and MSH-induced CRE activation in terms of kinetics, affinity, and desensitization in murine, hypothalamic mHypoA-2/10-CRE cells that stably express a CRE-dependent reporter gene construct. Physiologically relevant increases in extracellular glucose enhanced basal or MSH-induced CRE-dependent gene transcription, whereas prolonged elevated glucose concentrations reduced the sensitivity of mHypoA-2/10-CRE cells towards glucose. Glucose also induced CRCT-2 translocation into the nucleus and the AMPK activator metformin decreased basal and glucose-induced CRE activity, suggesting a role for AMPK/CRTC-2 in glucose-induced CRE activation. Accordingly, small interfering RNA-induced down-regulation of CRTC-2 expression decreased glucose-induced CRE-dependent reporter activation. Of note, glucose also induced expression of TRH, suggesting that glucose might affect the hypothalamic-pituitary-thyroid axis via the regulation of hypothalamic CRE activity. These findings significantly advance our knowledge about the impact of glucose on hypothalamic signaling and suggest that TRH release might account for the central anorexigenic effects of glucose and could represent a new molecular link between hyperglycaemia and thyroid dysfunction. PMID:27144291

  6. Rare-Earth Element determinations in Nigerian rock samples by instrumental neutron activation analysis

    Nineteen igneous and six sedimentary rock samples of various geological types from two major locations in Nigeria were analyzed for six Rare-Earth Elements (REE) (La, Ce, Sm, Eu, Tb, Yb) by instrumental neutron activation analysis. The chondrite-normalized REE patterns of the different rock types were compared with those of similar samples from other parts of the world. Suggestions are made concerning the probable petrogenesis of some of these rock samples, and the REE patterns of others are rationalized on the basis of the major minerals present in such rocks. 10 references, 2 figures, 2 tables

  7. Determination of trace elements in scalp hair of an elderly population by neutron activation analysis

    Neutron activation analysis was applied to assess trace elements concentrations in head hair from healthy elderly people living in the Sao Paulo metropolitan area. Concentrations of As, Br, Ca, Cl, Co, Cr, Cu, Fe, K, La, Mn, Na, Sb, Se and, Zn were determined. Comparisons were made between the results obtained for dyed and non-dyed hair as well as for hair from females and males of two different age groups. The results were also compared with range values established by clinical laboratories and published data. (author)

  8. Comparison of elemental composition of hair between osteoporotic and normal women by instrumental neutron activation analysis

    Instrumental neutron activation analysis (INAA) was carried out on hair samples from a group of 20 patients undergoing a study of osteoporosis. Half of these were judged normal. Forteen elements were measured but only calcium was found to have a correlation with the disease state. Calcium levels in hair were significantly lower (99% level) in patients with osteoporosis. Conversely, calcium levels in the blood of osteoporotic patients were significantly higher (95% level) than those in normals. Though the group studied was small it is felt that levels of calcium in hair may be of value in diagnosing osteoporosis. (author)

  9. Comparison of elemental composition of hair between osteoporotic and normal women by instrumental neutron activation analysis

    Instrumental neutron activation analysis was carried out on hair samples from a group of twenty patients undergoing a study of osteoporosis. Half of these were judged normal. Fourteen elements were measured but only calcium was found to have a correlation with the disease state. Calcium levels in hair were significantly lower (99% confidence level) in patients with osteoporosis. Conversely, calcium levels in the blood of osteoporotic patients were significantly higher (95% confidence level) than those in normals. Though the group studied was small it is felt that the levels of calcium in hair may be of value in diagnosing osteoporosis. (author) 14 refs

  10. Analysis of essential elements in medicinal plants and their respective soils by neutron activation analysis

    In this study, the essential elements for humans in selected medicinal plants and their respective growing soils are measured by Neutron Activation Analysis. The concentrations of Na, K, Fe, Br, Al, Mn, Cl, Ca and Mg were analyzed using 20 kW KAMINI Reactor, Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam. Results show that justification for the usage of these medicinal plants in the treatment of various diseases. Moreover, these results can be useful for preparing dosage of the herbal formulations. (author)