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Sample records for nuclear microprobe analysis

  1. Materials analysis with a nuclear microprobe

    SciTech Connect

    Maggiore, C.J.

    1980-01-01

    The ability to produce focused beams of a few MeV light ions from Van de Graaff accelerators has resulted in the development of nuclear microprobes. Rutherford backscattering, nuclear reactions, and particle-induced x-ray emission are used to provide spatially resolved information from the near surface region of materials. Rutherford backscattering provides nondestructive depth and mass resolution. Nuclear reactions are sensitive to light elements (Z < 15). Particle-induced x-ray analysis is similar to electron microprobe analysis, but 2 orders of magnitude more sensitive. The focused beams are usually produced with specially designed multiplets of magnetic quadrupoles. The LASL microprobe uses a superconducting solenoid as a final lens. The data are acquired by a computer interfaced to the experiment with CAMAC. The characteristics of the information acquired with a nuclear microprobe are discussed; the means of producing the beams of nuclear particles are described; and the limitations and applications of such systems are given.

  2. Analysis of biological materials using a nuclear microprobe

    NASA Astrophysics Data System (ADS)

    Mulware, Stephen Juma

    The use of nuclear microprobe techniques including: Particle induced x-ray emission (PIXE) and Rutherford backscattering spectrometry (RBS) for elemental analysis and quantitative elemental imaging of biological samples is especially useful in biological and biomedical research because of its high sensitivity for physiologically important trace elements or toxic heavy metals. The nuclear microprobe of the Ion Beam Modification and Analysis Laboratory (IBMAL) has been used to study the enhancement in metal uptake of two different plants. The roots of corn (Zea mays) have been analyzed to study the enhancement of iron uptake by adding Fe (II) or Fe(III) of different concentrations to the germinating medium of the seeds. The Fe uptake enhancement effect produced by lacing the germinating medium with carbon nanotubes has also been investigated. The aim of this investigation is to ensure not only high crop yield but also Fe-rich food products especially from calcareous soil which covers 30% of world's agricultural land. The result will help reduce iron deficiency anemia, which has been identified as the leading nutritional disorder especially in developing countries by the World Health Organization. For the second plant, Mexican marigold (Tagetes erecta ), the effect of an arbuscular mycorrhizal fungi (Glomus intraradices ) for the improvement of lead phytoremediation of lead contaminated soil has been investigated. Phytoremediation provides an environmentally safe technique of removing toxic heavy metals (like lead), which can find their way into human food, from lands contaminated by human activities like mining or by natural disasters like earthquakes. The roots of Mexican marigold have been analyzed to study the role of arbuscular mycorrhizal fungi in enhancement of lead uptake from the contaminated rhizosphere.

  3. Nuclear microprobe analysis of lead profile in crocodile bones

    NASA Astrophysics Data System (ADS)

    Orlic, I.; Siegele, R.; Hammerton, K.; Jeffree, R. A.; Cohen, D. D.

    2003-09-01

    Elevated concentrations of lead were found in Australian free ranging saltwater crocodile ( Crocodylus porosus) bone and flesh. Lead shots were found as potential source of lead in these animals. ANSTO's heavy ion nuclear microprobe was used to measure the distribution of Pb in a number of bones and osteoderms. The aim was to find out if elevated Pb concentration remains in growth rings and if the concentration is correlated with the blood levels recorded at the time. Results of our study show a very distinct distribution of accumulated Pb in bones and osteoderms as well as good correlation with the level of lead concentration in blood. To investigate influence of ion species on detection limits measurements of the same sample were performed by using 3 MeV protons, 9 MeV He ions and 20 MeV carbon ions. Peak to background ratios, detection limits and the overall 'quality' of obtained spectra are compared and discussed.

  4. Nuclear micro-probe analysis of Arabidopsis thaliana leaves

    NASA Astrophysics Data System (ADS)

    Ager, F. J.; Ynsa, M. D.; Domínguez-Solís, J. R.; López-Martín, M. C.; Gotor, C.; Romero, L. C.

    2003-09-01

    Phytoremediation is a cost-effective plant-based approach for remediation of soils and waters which takes advantage of the remarkable ability of some plants to concentrate elements and compounds from the environment and to metabolize various molecules in their tissues, such as toxic heavy metals and organic pollutants. Nowadays, phytoremediation technology is becoming of paramount importance when environmental decontamination is concerned, due to the emerging knowledge of its physiological and molecular mechanisms and the new biological and engineering strategies designed to optimize and improve it. In addition, the feasibility of using plants for environmental cleanup has been confirmed by many different trials around the world. Arabidopsis thaliana plants can be used for basic studies to improve the technology on phytoremediation. Making use of nuclear microscopy techniques, in this paper we study leaves of wild type and transgenic A. thaliana plants grown in a cadmium-rich environment under different conditions. Micro-PIXE, RBS and SEM analyses, performed on the scanning proton micro-probe at the CNA in Seville (Spain), prove that cadmium is preferentially sequestered in the central region of epidermal trichome and allow comparing the effects of genetic modifications.

  5. Technical aspects of nuclear microprobe analysis of senile plaques from alzheimer patients

    NASA Astrophysics Data System (ADS)

    Larsson, N. P.-O.; Tapper, U. A. S.; Sturesson, K.; Odselius, R.; Brun, A.

    1990-04-01

    Alzheimer's disease, a common form of senile dementia, has been proposed to be caused by aluminium. One of the interesting structures to be studied, senile plaque cores in the brain, have centres of only about 10 μm. We have investigated the possibility of applying nuclear microprobes to sections containing senile plaques. An alternative staining procedure, TMToluidin blue staining using a spray technique, is also presented. An outline is given of a procedure for preparing senile plaque specimens for nuclear microprobe analysis. This includes a technique for accurate ion beam positioning, utilizing electron microscopy-grids. The subject may be of general interest since sample preparation is one of the most important aspects in microprobe analysis of biological matter.

  6. Mars Microprobe Entry Analysis

    NASA Technical Reports Server (NTRS)

    Braun, Robert D.; Mitcheltree, Robert A.; Cheatwood, F. McNeil

    1998-01-01

    The Mars Microprobe mission will provide the first opportunity for subsurface measurements, including water detection, near the south pole of Mars. In this paper, performance of the Microprobe aeroshell design is evaluated through development of a six-degree-of-freedom (6-DOF) aerodynamic database and flight dynamics simulation. Numerous mission uncertainties are quantified and a Monte-Carlo analysis is performed to statistically assess mission performance. Results from this 6-DOF Monte-Carlo simulation demonstrate that, in a majority of the cases (approximately 2-sigma), the penetrator impact conditions are within current design tolerances. Several trajectories are identified in which the current set of impact requirements are not satisfied. From these cases, critical design parameters are highlighted and additional system requirements are suggested. In particular, a relatively large angle-of-attack range near peak heating is identified.

  7. Nuclear microprobe analysis of muscle biopsies: Applications in pathology and clinic

    NASA Astrophysics Data System (ADS)

    Moretto, Ph; Coquet, M.; Gherardi, R. K.; Stoedzel, P.

    2000-03-01

    The nuclear microprobe analysis of muscle biopsy sections has been recently applied to investigate different muscle disorders. This technique, employed as a complementary examination in the frame of pathological studies, permitted to confirm the diagnosis for a first pathology and to elucidate the cause of a second. In skeletal muscles of a young patient suffering from a slow progressive myopathy, calcium accumulations have been demonstrated in histologically abnormal fibers. These findings have been compared to histopathological characteristics previously described. On the other hand, we have evaluated muscle sections from two patients who presented symptoms of an inflammatory myopathy, a rare pathology that recently emerged in France. The chemical analyses permitted us to highlight local aluminium infiltration in muscles. The hypothesis of an unusual reaction to intramuscular aluminium accumulation has been advanced. These studies demonstrate the capability for ion beam microanalytical techniques to address acute problems in pathology.

  8. Intracochlear microprobe analysis

    SciTech Connect

    Bone, R.C.; Ryan, A.F.

    1982-04-01

    Energy dispersive x-ray analysis (EDXA) or microprobe analysis provides cochlear physiologists with a means of accurately assessing relative ionic concentrations in selected portions of the auditory mechanism. Rapid freezing followed by lyophilization allows the recovery of fluid samples in crystalline form not only from perilymphatic and endolymphatic spaces, but also from much smaller subregions of the cochlea. Because samples are examined in a solid state, there is no risk of diffusion into surrounding or juxtaposed fluids. Samples of cochlear tissues may also be evaluated without the danger of intercellular ionic diffusion. During direct visualization by scanning electron microscopy, determination of the biochemical makeup of the material being examined can be simultaneously, assuring the source of the data collected. Other potential advantages and disadvantages of EDXA are reviewed. Initial findings as they relate to endolymph, perilymph, stria vascularis, and the undersurface of the tectorial membrane are presented.

  9. Nuclear microprobe analysis and source apportionment of individual atmospheric aerosol particles

    NASA Astrophysics Data System (ADS)

    Artaxo, Paulo; Rabello, Marta L. C.; Watt, Frank; Grime, Geoff; Swietlicki, Erik

    1993-04-01

    In atmospheric aerosol research, one key issue is to determine the sources of the airborne particles. Bulk PIXE analysis coupled with receptor modeling provides a useful, but limited view of the aerosol sources influencing one particular site or sample. The scanning nuclear microprobe (SNM) technique is a microanalytical technique that gives unique information on individual aerosol particles. In the SNM analyses a 1.0 μm size 2.4 MeV proton beam from the Oxford SNM was used. The trace elements with Z > 11 were measured by the particle induced X-ray emission (PIXE) method with detection limits in the 1-10 ppm range. Carbon, nitrogen and oxygen are measured simultaneously using Rutherford backscattering spectrometry (RBS). Atmospheric aerosol particles were collected at the Brazilian Antarctic Station and at biomass burning sites in the Amazon basin tropical rain forest in Brazil. In the Antarctic samples, the sea-salt aerosol particles were clearly predominating, with NaCl and CaSO 4 as major compounds with several trace elements as Al, Si, P, K, Mn, Fe, Ni, Cu, Zn, Br, Sr, and Pb. Factor analysis of the elemental data showed the presence of four components: 1) soil dust particles; 2) NaCl particles; 3) CaSO 4 with Sr; and 4) Br and Mg. Strontium, observed at 20-100 ppm levels, was always present in the CaSO 4 particles. The hierarchical cluster procedure gave results similar to the ones obtained through factor analysis. For the tropical rain forest biomass burning aerosol emissions, biogenic particles with a high organic content dominate the particle population, while K, P, Ca, Mg, Zn, and Si are the dominant elements. Zinc at 10-200 ppm is present in biogenic particles rich in P and K. The quantitative aspects and excellent detection limits make SNM analysis of individual aerosol particles a very powerful analytical tool.

  10. Electron microprobe mineral analysis guide

    NASA Technical Reports Server (NTRS)

    Brown, R. W.

    1980-01-01

    Electron microprobe mineral analysis guide is a compilation of X-ray tables and spectra recorded from various mineral matrices. Spectra were obtained using electron microprobe, equipped with LiF geared, curved crystal X-ray spectrometers, utilizing typical analytical operating conditions: 15 Kv acceleration potential, 0.02 microampere sample current as measured on a clinopyroxene standard (CP19). Tables and spectra are presented for the majority of elements, fluorine through uranium, occurring in mineral samples from lunar, meteoritic and terrestrial sources. Tables for each element contain relevant analytical information, i.e., analyzing crystal, X-ray peak, background and relative intensity information, X-ray interferences and a section containing notes on the measurement. Originally intended to cover silicates and oxide minerals the tables and spectra have been expanded to cover other mineral phases. Electron microprobe mineral analysis guide is intended as a spectral base to which additional spectra can be added as the analyst encounters new mineral matrices.

  11. In situ titanium dioxide nanoparticles quantitative microscopy in cells and in C. elegans using nuclear microprobe analysis

    NASA Astrophysics Data System (ADS)

    Le Trequesser, Quentin; Saez, Gladys; Devès, Guillaume; Michelet, Claire; Barberet, Philippe; Delville, Marie-Hélène; Seznec, Hervé

    2014-12-01

    Detecting and tracking nanomaterials in biological systems is challenging and essential to understand the possible interactions with the living. In this context, in situ analyses were conducted on human skin cells and a multicellular organism (Caenorhabditiselegans) exposed to titanium dioxide nanoparticles (TiO2 NPs) using nuclear microprobe. Coupled to conventional methods, nuclear microprobe was found to be suitable for accurate description of chemical structure of biological systems and also for detection of native TiO2 NPs. The method presented herein opens the field to NPs exposure effects analyses and more generally to toxicological analyses assisted by nuclear microprobe. This method will show applications in key research areas where in situ imaging of chemical elements is essential.

  12. Data acquisition with a nuclear microprobe

    SciTech Connect

    Maggiore, C.

    1980-01-01

    Spatially resolved information from the near surfaces of materials can be obtained with a nuclear microprobe. The spatial resolution is determined by the optics of the instrument and radiation damage in the specimen. Two- and three-dimensional maps of elemental concentration may be obtained from the near surfaces of materials. Data are acquired by repeated scans of a constantly moving beam over the region of interest or by counting for a preset integrated charge at each specimen location.

  13. Microprobe analysis of chlorpromazine pigmentation

    SciTech Connect

    Benning, T.L.; McCormack, K.M.; Ingram, P.; Kaplan, D.L.; Shelburne, J.D.

    1988-10-01

    We describe the histochemical, ultrastructural, and microanalytical features of a skin biopsy specimen obtained from a patient with chlorpromazine pigmentation. Golden-brown pigment granules were present in the dermis, predominantly in a perivascular arrangement. The granules stained positively with the Fontana-Masson stain for silver-reducing substances and negatively with Perl's stain for iron. Electron microscopy revealed dense inclusion bodies in dermal histiocytes, pericytes, endothelial cells, and Schwann cells, as well as lying free in the extracellular matrix. These ''chlorpromazine bodies'' were quite dense even in unosmicated, unstained ultrathin sections, indicating that the pigmentation is related, at least in part, to the inclusions. Microprobe analysis of the chlorpromazine bodies revealed a striking peak for sulfur, which strongly suggests the presence of the drug or its metabolite within these inclusions.

  14. Nuclear microprobe analysis of wear tracks on 14N-implanted steels

    NASA Astrophysics Data System (ADS)

    Doyle, B. L.; Follstaedt, D. M.; Picraux, S. T.; Yost, F. G.; Pope, L. E.; Knapp, J. A.

    1985-03-01

    Two nuclear microbeam analysis techniques [3,7 MeV(α,p) and 6 MeV(α, α)] have been used to determine the local areal density of 14N which remains in wear tracks resulting from pin-on-disc testing of nitrogen implanted 15-5 PH and 304 stainless steels. The microbeam analysis shows that the extent of N migration into the 15-5 substrate was to depths ≲ 0.5 μm, but perhaps to ≲ 1.0 μm in 304. The as-implanted layer in 15-5 PH contains up to 40-45 at.% N and consists principally of ∼ 2 μm particles of (Fe, Cr) 2N 1-x. When sufficient wear has occurred in 304 to lower the N content below 10 17 N/cm 2, an O buildup to 2 × 10 17 O/cm 2 is observed; however the presence of N does not correlate with low O levels in the wear tracks of 15-5 PH.

  15. Electron microprobe analysis of cryolite

    NASA Astrophysics Data System (ADS)

    Guimarães, F.; Bravo Silva, P.; Ferreira, J.; Piedade, A. P.; Vieira, M. T. F.

    2014-03-01

    A sample of cryolite was studied with a JEOL JXA 8500-F electron microprobe under several operating conditions. A TAP crystal was used to analyse Na and Al and a LDE1 crystal to analyse F. As F and Na are both highly "volatile" elements, special care must be taken during analysis. The measurement order of Na, F and Al is not irrelevant and optimum conditions may also result in different combinations of accelerating voltage, beam current, beam size or counting times. Relevant X-ray signals were recorded in order to investigate the behaviour of the Na Ka and F Ka counts with elapsed time. The incident beam current was also recorded at the same time. In a clear contrast to what has normally been reported in the EPMA analysis of aluminosilicates and silicate glasses, we found that the Na X-ray counts increase with time. This increment of X-rays intensities for sodium in cryolite depends on the operating conditions and is accompanied by a strong migration of fluorine from the beam excitation volume, leading to a decrease in F X-ray counting rates. It was also observed that higher incident beam currents induce higher radiation damage in the mineral. The current instability is consistent with possible electron induced dissociation in the cryolite structure. An analytical protocol was achieved for 6 kV and 15kV accelerating voltage for the correct EPMA analysis of cryolite.

  16. Study of metal bioaccumulation by nuclear microprobe analysis of algae fossils and living algae cells

    NASA Astrophysics Data System (ADS)

    Guo, P.; Wang, J.; Li, X.; Zhu, J.; Reinert, T.; Heitmann, J.; Spemann, D.; Vogt, J.; Flagmeyer, R.-H.; Butz, T.

    2000-03-01

    Microscopic ion-beam analysis of palaeo-algae fossils and living green algae cells have been performed to study the metal bioaccumulation processes. The algae fossils, both single cellular and multicellular, are from the late Neoproterozonic (570 million years ago) ocean and perfectly preserved within a phosphorite formation. The biosorption of the rare earth element ions Nd 3+ by the green algae species euglena gracilis was investigated with a comparison between the normal cells and immobilized ones. The new Leipzig Nanoprobe, LIPSION, was used to produce a proton beam with 2 μm size and 0.5 nA beam current for this study. PIXE and RBS techniques were used for analysis and imaging. The observation of small metal rich spores ( <10 μm) surrounding both of the fossils and the living cells proved the existence of some specific receptor sites which bind metal carrier ligands at the microbic surface. The bioaccumulation efficiency of neodymium by the algae cells was 10 times higher for immobilized algae cells. It confirms the fact that the algae immobilization is an useful technique to improve its metal bioaccumulation.

  17. The Fudan nuclear microprobe set-up and performance

    NASA Astrophysics Data System (ADS)

    Zhong, L.; Zhuang, W.; Shen, H.; Mi, Y.; Wu, Y.; Liu, B.; Yang, M.; Cheng, H.

    2007-07-01

    A new scanning nuclear microprobe has been constructed at the Institute of Modern Physics in Fudan University, to replace the old microbeam system which had been running for more than ten years. The key parts were purchased from Oxford Microbeams Ltd., including triplet quadrupole lens (model OM-150), collimator slits, scanning system, target chamber, and data acquisition system. Ion beams are provided from a NEC 9SDH-2 Tandem accelerator. Three CCD cameras and multiple monitors were installed to assist beam adjust. The design of beam line and beam monitors is described. Beam optics calculations were carried out based on the specific Fudan microprobe system geometry, and the results regarding beam line performance and limitations of the spacial resolution are presented and discussed here. A comparison with experimental results is given as well. About 1.5 μm beam spot size could be achieved with a 3 MeV proton beam at a current of around 10 pA. Recently, the new microprobe is applied to obtain information of fly ash particle, algae cell and otoliths.

  18. Application of Nuclear Microprobes towards Understanding Complex Ore Geo-electrochemistry

    NASA Astrophysics Data System (ADS)

    Laird, J. S.; Szymanski, R.; Large, R.; Ryan, C. G.

    2012-10-01

    We report on recent development on the CSIRO Nuclear Microprobe (NMP) towards catering for long exposure mapping required for large area scanning. A new data collection system based on Labview FPGA highly co-ordinated with beam transport sits at the heart of the upgrade. These upgrades are discussed and an example of the systems use for μ-Particle Induced X-ray Emission (PIXE) analysis in the area of complex ore geo-electrochemistry is briefly described.

  19. Nuclear microprobe and optical investigation of sparkling wine bottles

    NASA Astrophysics Data System (ADS)

    Padayachee, J.; Prozesky, V. M.; Pineda, C. A.

    1999-10-01

    Glass bottles, used for sparkling wine, are treated with freon during manufacturing to harden the inside surface. Although this type of treatment normally improves the properties of the glass, in this case the occurrence of "egg" formations (egg-shaped rough areas) on distinct areas of bottles, as well as yeast sticking to the insides of bottles at specific areas pointed to the possibility of different areas showing different properties in the same bottle. The question was whether the correct gas was used for the treatment, and secondly, whether the process was controlled well enough to obtain the correct properties for the inside of the glass. We present results of an optical microscopy and nuclear microprobe (NMP) investigation.

  20. Quantitative elemental imaging of octopus stylets using PIXE and the nuclear microprobe

    NASA Astrophysics Data System (ADS)

    Doubleday, Zoë; Belton, David; Pecl, Gretta; Semmens, Jayson

    2008-01-01

    By utilising targeted microprobe technology, the analysis of elements incorporated within the hard bio-mineralised structures of marine organisms has provided unique insights into the population biology of many species. As hard structures grow, elements from surrounding waters are incorporated effectively providing a natural 'tag' that is often unique to the animal's particular location or habitat. The spatial distribution of elements within octopus stylets was investigated, using the nuclear microprobe, to assess their potential for determining dispersal and population structure in octopus populations. Proton Induced X-ray Emission (PIXE) was conducted using the Dynamic Analysis method and GeoPIXE software package, which produced high resolution, quantitative elemental maps of whole stylet cross-sections. Ten elements were detected within the stylets which were heterogeneously distributed throughout the microstructure. Although Ca decreased towards the section edge, this trend was consistent between individuals and remained homogeneous in the inner region of the stylet, and thus appears a suitable internal standard for future microprobe analyses. Additional analyses used to investigate the general composition of the stylet structure suggested that they are amorphous and largely organic, however, there was some evidence of phosphatic mineralisation. In conclusion, this study indicates that stylets are suitable for targeted elemental analysis, although this is currently limited to the inner hatch region of the microstructure.

  1. Microprobe analysis of brine shrimp grown on meteorite extracts

    NASA Astrophysics Data System (ADS)

    Kennedy, J.; Mautner, M. N.; Barry, B.; Markwitz, A.

    2007-07-01

    Nuclear microprobe methods have been used to investigate the uptake and distribution of various elements by brine shrimps and their unhatched eggs when grown in extracts of the Murchison and Allende carbonaceous meteorites, which were selected as model space resources. Measurements were carried out using a focussed 2 MeV proton beam raster scanned over the samples in order to obtain the average elemental concentrations. Line scans across the egg and shrimp samples show uptake of elements such as Mg, Ni, S and P which are present in the meteorites. The results confirmed that carbonaceous chondrite materials can provide nutrients, including high levels of the essential nutrient phosphate. The concentrations of these elements varied significantly between shrimp and eggs grown in extracts of the two meteorite types, which can help in identifying optimal growth media. Our results illustrate that nuclear microprobe techniques can determine elemental concentrations in organisms exposed to meteorite derived media and thus help in identifying useful future resources.

  2. An integrated computer system for Fudan nuclear microprobe

    NASA Astrophysics Data System (ADS)

    Zou, Degang; Ren, Chigang; Tang, Jiayong; Yang, Fujia

    1995-09-01

    With the help of modern personal computer (PC) and object oriented programming (OOP) technology, we have recently developed a compact, integrated, user-friendly computer system for Fudan nuclear microprobe, which was originally modeled after the SUNY/Albany system. The system software has been thoroughly rewritten so as to take advantage of today's high-performance PC and facilitate easy upgrading and expansion in the case of future development of both hardware and software. Most functions of this system such as sample searching, scanning control, data acquisition, image processing and displaying, are based on a single 80386 IBM style PC with a 1-MB DRAM TVGA high-resolution monitor. Data from up to 4 ADCs, 4 sensors and a CCD camera can be acquired simultaneously. Two stepper motors are employed to move the target; a CCD camera system is also included to locate the area of interest on the sample; the secondary electron image could act as a reference to fine adjustment. Rectangular raster scanning or irregular scanning is facilitated with beam motion triggered either by a timer or by pulses from a current integrator. A variety of built-in image displaying, processing and printing methods have also been implemented in order to make the maps easier to interpret for the eyes. All of these functions are administrated by an integrated, completely menu-driven software package-MBSYS.

  3. Effect of magnetic quadrupole lens alignment on a nuclear microprobe resolution

    NASA Astrophysics Data System (ADS)

    Kolinko, S. V.; Ponomarev, A. G.

    2016-04-01

    The paper reports the research trends in developing probe-forming systems with high demagnification and analysis factors that limit a nuclear microprobe resolution. Parasitic aberrations caused by tilts and offsets of magnetic quadrupoles are studied in terms of their effect on probe parameters on a target. The most common arrangements of probe-forming systems such as a triplet and "Russian quadruplet" with separated geometry are considered. The accuracy prerequisites for the positioning of the quadrupoles are defined, and practical guidelines for alignment of probe-forming systems with high demagnification factors are suggested.

  4. The Debrecen Scanning Nuclear Microprobe and its Applications in Biology and Environmental Science

    SciTech Connect

    Kertesz, Zsofia

    2007-11-26

    Nuclear microscopy is one of the most powerful tools which are able to determine quantitative trace element distributions in complex samples on a microscopic scale. The advantage of nuclear microprobes are that different ion beam analytical techniques, like PIXE, RBS, STIM and NRA can be applied at the same time allowing the determination of the sample structure, major, minor and trace element distribution simultaneously.In this paper a nuclear microprobe setup developed for the microanalysis of thin complex samples of organic matrix at the Debrecen Scanning Nuclear Microprobe Facility is presented. The application of nuclear microscopy in life sciences is shown through an example, the study of penetration of TiO{sub 2} nanoparticles of bodycare cosmetics in skin layers.

  5. New CAMAC based data acquisition and beam control system for Lund nuclear microprobe

    NASA Astrophysics Data System (ADS)

    Elfman, Mikael; Kristiansson, Per; Malmqvist, Klas; Pallon, Jan; Sjöland, Anders; Utui, Rogerio; Yang, Changyi

    1997-07-01

    A new CAMAC based data acquisition system has been installed at the Lund Nuclear Microprobe facility. This paper reports on the development and present status of the data acquisition system. The system is a true multiparameter CAMAC based system with fast Fera bus readout and in crate memory buffer. The user interface is based on Sparrow Kmax software for a Power Macintosh platform. The system read out and tag the event data with position on-line, which make fast on-line monitoring of spectra or element maps possible.Simultaneously, all data can be saved event by event for off-line analysis. The beam scanning part is software controlled through a timed D/A converter, this allows fast scanning of the beam. With a CCD-camera and video card the area to be analysed could be defined directly from the image, and the sample position can be moved. Any kind of irregular scan patterns could be defined.

  6. Wavelength dispersive analysis with the synchrotron x ray fluorescence microprobe

    NASA Technical Reports Server (NTRS)

    Rivers, M. L.; Thorn, K. S.; Sutton, S. R.; Jones, K. W.; Bajt, S.

    1993-01-01

    A wavelength dispersive spectrometer (WDS) was tested on the synchrotron x ray fluorescence microprobe at Brookhaven National Laboratory. Compared to WDS spectra using an electron microprobe, the synchrotron WDS spectra have much better sensitivity and, due to the absence of bremsstrahlung radiation, lower backgrounds. The WDS spectrometer was successfully used to resolve REE L fluorescence spectra from standard glasses and transition metal K fluorescence spectra from kamacite.

  7. Light stable isotope analysis of meteorites by ion microprobe

    NASA Technical Reports Server (NTRS)

    Mcsween, Harry Y., Jr.

    1994-01-01

    The main goal was to develop the necessary secondary ion mass spectrometer (SIMS) techniques to use a Cameca ims-4f ion microprobe to measure light stable isotope ratios (H, C, O and S) in situ and in non-conducting mineral phases. The intended application of these techniques was the analysis of meteorite samples, although the techniques that have been developed are equally applicable to the investigation of terrestrial samples. The first year established techniques for the analysis of O isotope ratios (delta O-18 and delta O-17) in conducting mineral phases and the measurement of S isotope ratios (delta S-34) in a variety of sulphide phases. In addition, a technique was developed to measure delta S-34 values in sulphates, which are insulators. Other research undertaken in the first year resulted in SIMS techniques for the measurement of wide variety of trace elements in carbonate minerals, with the aim of understanding the nature of alteration fluids in carbonaceous chondrites. In the second year we developed techniques for analyzing O isotope ratios in nonconducting mineral phases. These methods are potentially applicable to the measurement of other light stable isotopes such as H, C and S in insulators. Also, we have further explored the analytical techniques used for the analysis of S isotopes in sulphides by analyzing troilite in a number of L and H ordinary chondrites. This was done to see if there was any systematic differences with petrological type.

  8. Laser microprobe facility used in the elemental analysis of small feature of a sample

    NASA Technical Reports Server (NTRS)

    Baldwin, J. M.

    1969-01-01

    Laser microprobe facility is effective in the elemental analysis of small areas of heterogeneous samples. The instrument uses the focused beam of a pulsed laser to evaporate a small volume of material from a relatively massive sample.

  9. Development of an external beam nuclear microprobe on the Aglae facility of the Louvre museum

    NASA Astrophysics Data System (ADS)

    Calligaro, T.; Dran, J.-C.; Ioannidou, E.; Moignard, B.; Pichon, L.; Salomon, J.

    2000-03-01

    The external beam line of our facility has been recently equipped with the focusing system previously mounted on a classical nuclear microprobe. When using a 0.1 μm thick Si 3N 4 foil for the exit window and flowing helium on the sample under analysis, a beam spot as small as 10 μm is attainable at a distance of 3 mm from the window. Elemental micromapping is performed by mechanical scanning. An electronic device has been designed which allows XY scanning by moving the sample under the beam by steps down to 0.1 μm. Beam monitoring is carried out by means of the weak X-ray signal emitted by the exit foil and detected by a specially designed Si(Li) detector cooled by Peltier effect. The characteristics of external beams of protons and alpha particles are evaluated by means of resonance scanning and elemental mapping of a grid. An example of application is presented, dealing with elemental micro-mapping of inclusions in gemstones.

  10. RAMAN MICROPROBE ANALYSIS OF STATIONARY SOURCE PARTICULATE POLLUTANTS

    EPA Science Inventory

    The application of Raman spectroscopy to the molecular characterization of individual particles from stationary sources is described. The NBS-developed Raman microprobe has been used to characterize microparticles of oil- and coal-fired power plant emissions and boiler samples co...

  11. An x-ray microprobe beam line for trace element analysis

    SciTech Connect

    Gordon, B.M.; Hanson, A.L.; Jones, K.W.; Kwiatek, W.M.; Long, G.J.; Pounds, J.G.; Schidlovsky, G.; Spanne, P.; Rivers, M.L.; Sutton, S.R.

    1987-01-01

    The application of synchrotron radiation to an x-ray microprobe for trace element analysis is a complementary and natural extension of existing microprobe techniques using electrons, protons, and heavier ions as excitation sources for x-ray fluorescence. The ability to focus charged particles leads to electron microprobes with spatial resolutions in the sub-micrometer range and down to 100 ppM detection limits and proton microprobes with micrometer resolution and ppM detection limits. The characteristics of synchrotron radiation that prove useful for microprobe analysis include a broad and continuous energy spectrum, a relatively small amount of radiation damage compared to that deposited by charged particles, a highly polarized source which reduces background scattered radiation in an appropriate counting geometry, and a small vertical divergence angle of approx.0.2 mrad which allows for focussing of the light beam into a small spot with high flux. The features of a dedicated x-ray microprobe beam line developed at the National Synchrotron Light Source (NSLS) are described. 4 refs., 3 figs.

  12. Nuclear Microprobe using Elastic Recoil Detection (ERD) for Hydrogen Profiling in High Temperature Protonic Conductors

    NASA Technical Reports Server (NTRS)

    Berger, Pascal; Sayir, Ali; Berger, Marie-Helene

    2004-01-01

    The interaction between hydrogen and various high temperature protonic conductors (HTPC) has not been clearly understood due to poor densification and unreacted secondary phases. the melt-processing technique is used in producing fully dense simple SrCe(0.9)Y (0.10) O(3-delta) and complex Sr3Ca(1+x)Nb(2+x)O(9-delta) perovskites that can not be achieved by solid-state sintering. the possibilities of ion beam analysis have been investigated to quantify hydrogen distribution in HTPC perovskites subjected to water heat treatment. Nuclear microprobe technique is based on the interactions of a focused ion beam of MeV light ions (H-1, H-2, He-3, He-4,.) with the sample to be analyzed to determine local elemental concentrations at the cubic micrometer scale, the elastic recoil detection analysis technique (ERDA) has been carried out using He-4(+) microbeams and detecting the resulting recoil protons. Mappings of longitudinal sections of water treated SrCeO3 and Sr(Ca(1/3)Nb(2/3))O3 perovskites have been achieved, the water treatment strongly alters the surface of simple SrCe(0.9)Y(0.10)O(3-delta) perovskite. From Rutherford Back Scattering measurements (RBS), both Ce depletion and surface re-deposition is evidenced. the ERDA investigations on water treated Sr3Ca(1+x)Nb(2+x)O(9-delta) perovskite did not exhibit any spatial difference for the hydrogen incorporation from the surface to the centre. the amount of hydrogen incorporation for Sr3Ca(1+x)Nb(2+x)O(9-delta) was low and required further development of two less conventional techniques, ERDA in forward geometry and forward elastic diffusion H-1(p,p) H-1 with coincidence detection.

  13. Microprobe PIXE analysis of aluminium in the brains of patients with Alzheimer's disease

    NASA Astrophysics Data System (ADS)

    Yumoto, S.; Horino, Y.; Mokuno, Y.; Kakimi, S.; Fujii, K.

    1996-04-01

    To investigate the cause of Alzheimer's disease (senile dementia), we examined aluminium (Al) in the rat liver, and in the brains (hippocampus) of Alzheimer's disease patients using heavy ion (5 MeV Si 3+) microprobe and proton (2 MeV) microprobe PIXE analysis. Heavy ion microprobes (3 MeV Si 2+) have several time's higher sensitivity for Al detection than 2 MeV proton microprobes. (1) In the rat liver, Al was detected in the cell nuclei, where phosphorus (P) was most densely distributed. (2) We also demonstrated Al in the cell nuclei isolated from Alzheimer's disease brains using heavy ion (5 MeV Si 3+) microprobes. Al spectra were detected using 2 MeV proton microprobes in the isolated brain cell nuclei. Al could not be observed in areas where P was present in relatively small amounts, or was absent. Our results indicate that Alzheimer's disease is caused by irreversible accumulation of Al in the nuclei of brain cells.

  14. Evaluation of the odd-even effect in limits of detection for electron microprobe analysis of natural minerals.

    PubMed

    Verma, Surendra P; Pandarinath, Kailasa; Velasco-Tapia, Fernando; Rodríguez-Ríos, Rodolfo

    2009-04-13

    Limit of detection (LOD), being a fundamental quality parameter for analytical techniques, has been recently investigated and a systematic behavior has been observed for most odd-even element pairs for many techniques. However, to the best of our knowledge very few LOD data are available in published literature for electron microprobe analysis; these consist of three papers, two being on rare-earth elements and the third covering a large number of elements of atomic number between 21 and 92. These data confirm the systematic behavior of LODs for many odd-even pairs. To initiate to full this gap, we determined LODs for several major rock-forming chemical elements from Na to Fe with atomic numbers between 11 and 26, during the microprobe analysis of common minerals (olivine, plagioclase, pyroxene, amphibole, quartz, and opaques) in volcanic rocks. The odd-even effect of nuclear stability seems to be present in LOD data for most odd-even pairs investigated. Nevertheless, the experimental strategy concerning the reference materials, calibration procedure, and blank measurements, should be substantially modified to better evaluate the systematic behavior of LOD values in microprobe analysis. PMID:19327450

  15. Recent advances in laser microprobe mass analysis (LAMMA) of inner ear tissue

    SciTech Connect

    Meyer zum Gottesberge-Orsulakova, A.; Kaufmann, R.

    1985-01-01

    Maintenance of ionic gradients within the various fluids compartments of the inner ear requires transport active cellular systems at different locations. LAMMA analysis is ideally suited for detection of ions in microquantity on cellular levels overcoming many technical difficulties. The present paper summarizes the results of microprobe analysis obtained with laser induced mass spectrometry (LAMMA) supplemented by X-ray microprobe analysis of epithelial cell layers adjacent to the endolymphatic space in the cochlear duct, in the vestibular organ and in the endolymphatic sac. The possible role of inner ear as well as ocular melanin in the mechanisms of active ion transport is discussed.

  16. Microprobe analysis of teeth by synchrotron radiation: environmental contamination

    NASA Astrophysics Data System (ADS)

    Pinheiro, T.; Carvalho, M. L.; Casaca, C.; Barreiros, M. A.; Cunha, A. S.; Chevallier, P.

    1999-10-01

    An X-ray fluorescence set-up with microprobe capabilities, installed at the Laboratoire pour l'Utilisation du Rayonnement Électromagnétique (LURE) synchrotron (France) was used for elemental determination in teeth. To evaluate the influence of living habits in dental elemental composition nine teeth collected post-mortem were analysed, five from a miner and four from a fisherman. All teeth from the fisherman were healthy. From the miner some teeth were carious and one of them was filled with metallic amalgam. Teeth were sliced under the vertical plane and each slice was scanned from the root to the enamel for elemental profile determination. The synchrotron microprobe resolution was of 100 μm and incident photons of 18 keV energy were used. The elemental concentration values found suggest heterogeneity of the teeth material. Moreover, the distinct profiles for Mn, Sr, Br and Pb were found when teeth from the miner and from the fisherman are compared which can be associated with dietary habits and environmental influence. Higher concentrations of Mn and Sr were found for the fisherman teeth. In addition, Br was only observed in this group of teeth. Pb levels are higher for the miner teeth in particular for dentine regions. The influence of amalgam, such as, increase of Zn and Hg contents in the teeth material, is only noticed for the immediate surroundings of the treated cavity.

  17. Millimeter length micromachining using a heavy ion nuclear microprobe with standard magnetic scanning

    NASA Astrophysics Data System (ADS)

    Nesprías, F.; Debray, M. E.; Davidson, J.; Kreiner, A. J.; Vega, N.; de la Fournière, E.

    2013-04-01

    In order to increase the scanning length of our microprobe, we have developed an irradiation procedure suitable for use in any nuclear microprobe, extending at least up to 400% the length of our heavy ion direct writing facility using standard magnetic exploration. Although this method is limited to patterns of a few millimeters in only one direction, it is useful for the manufacture of curved waveguides, optical devices such Mach-Zehnder modulators, directional couplers as well as channels for micro-fluidic applications. As an example, this technique was applied to the fabrication of 3 mm 3D-Mach-Zehnder modulators in lithium niobate with short Y input/output branches and long shaped parallel-capacitor control electrodes. To extend and improve the quality of the machined structures we developed new scanning control software in LabView™ platform. The new code supports an external dose normalization, electrostatic beam blanking and is capable of scanning figures at 16 bit resolution using a National Instruments™ PCI-6731 High-Speed I/O card. A deep and vertical micromachining process using swift 35Cl ions 70 MeV bombarding energy and direct write patterning was performed on LiNbO3, a material which exhibits a strong natural anisotropy to conventional etching. The micromachined structures show the feasibility of this method for manufacturing micro-fluidic channels as well.

  18. A novel approach to the examination of soil evidence: mineral identification using infrared microprobe analysis.

    PubMed

    Weinger, Brooke A; Reffner, John A; De Forest, Peter R

    2009-07-01

    Identification of minerals using the infrared microprobe with a diamond internal reflection objective is a rapid and reliable method for forensic soil examinations. Ninety-six mineral varieties were analyzed, and 77 were differentiated by their attenuated total reflection (ATR) spectra. Mineral grains may be mounted in oil for conventional polarized light microscope characterization and their ATR spectrum obtained with little or no interference by the liquid. This infrared microprobe method can be used to identify silicates, phosphates, nitrates, carbonates, and other covalent minerals; however, ionic minerals, metal oxide and sulfide minerals, and minerals with refractive indexes greater than diamond do not produce identifiable spectra, but the lack of a spectrum or one with high absorbance values does provide useful information. This research demonstrates the overall utility that infrared microprobe analysis brings mineral identification in soil evidence. PMID:19467138

  19. The use of the RBI nuclear microprobe in conservation process studies of a church portal

    NASA Astrophysics Data System (ADS)

    Pastuović, Ž.; Fazinić, S.; Jakšić, M.; Krstić, D.; Mudronja, D.

    2005-04-01

    The southern portal of the St. Marko church in Zagreb, Croatia, is currently under the process of conservation. The conservation treatments on calcareous sandstone consist of (i) removal of harmful sulfates (gypsum) from the surface of the material by saturated solution of ammonium carbonate; and (ii) treatment of the material surface with a 10% solution of barium hydroxide in order to convert the remaining dissolvable sulfates into non-dissolvable compounds and to strengthen the material surface. The nuclear microprobe has been used to measure the level of gypsum induced damage, and quality of conservation. More specifically, the surface quantity and depth concentration profiles of sulfur have been determined in several samples taken from the portal before and after the treatment with the solution of ammonium carbonate. To test the quality of treatment by the barium hydroxide solution, the depth concentration of barium in the samples has been determined after the treatment. Both sulfur and barium concentration levels have been determined by scanning the focused proton beam over the samples, detecting PIXE spectra and creating elemental distribution maps. Beside portal samples, the efficiency of the barium hydroxide treatment was tested on sandstone samples from nearby stone pit assumed to be the origin of material used for portal construction.

  20. Nuclear microprobe study of TiO 2-penetration in the epidermis of human skin xenografts

    NASA Astrophysics Data System (ADS)

    Kertész, Zs.; Szikszai, Z.; Gontier, E.; Moretto, P.; Surlève-Bazeille, J.-E.; Kiss, B.; Juhász, I.; Hunyadi, J.; Kiss, Á. Z.

    2005-04-01

    Titanium-dioxide is a widely used physical photoprotective component of various cosmetic products. However, very few experiments have been carried out on its penetration through the human epidermal barrier and its possible biological effects in vivo and in vitro. In the frame of the NANODERM EU5 project, the penetration of TiO2-nanoparticles through the epidermis of human foreskin grafts transplanted into SCID mice was investigated in the Debrecen and Bordeaux nuclear microprobe laboratories using combined IBA techniques. Transmission electron microscope studies of the same samples were also carried out in the DMPFCS laboratory. The skin grafts were treated with a hydrophobic emulsion containing micronised TiO2-nanoparticles in occlusion, for different time periods. Quantitative elemental concentrations and distributions have been determined in 14-16 μm thick freeze-dried sections obtained from quick frozen punch biopsies using STIM, PIXE and RBS analytical methods. Using both microscopic methods, we have observed nanoparticles having penetrated into the corneocyte layers of stratum corneum by direct visualisation in TEM and via their chemical fingerprint in PIXE. The human skin xenograft has proved to be a model particularly well adapted to such penetration studies.

  1. A Scanning Auger Microprobe analysis of corrosion products associated with sulfate reducing bacteria

    SciTech Connect

    Sadowski, R.A.; Chen, G.; Clayton, C.R.; Kearns, J.R.; Gillow, J.B.; Francis, A.J.

    1995-03-01

    A Scanning Auger Microprobe analysis was performed on the corrosion products of an austenitic AISI type 304 SS after a potentiostatic polarization of one volt for ten minutes in a modified Postgate`s C media containing sulfate reducing bacteria. The corrosion products were characterized and mapped in local regions where pitting was observed. A critical evaluation of the applicability of this technique for the examination of microbially influenced corrosion (MIC) is presented.

  2. Study of microstructure and silicon segregation in cast iron using color etching and electron microprobe analysis

    SciTech Connect

    Vazehrad, S.; Diószegi, A.

    2015-06-15

    An investigation on silicon segregation of lamellar, compacted and nodular graphite iron was carried out by applying a selective, immersion color etching and a modified electron microprobe to study the microstructure. The color etched micrographs of the investigated cast irons by revealing the austenite phase have provided data about the chronology and mechanism of microstructure formation. Moreover, electron microprobe has provided two dimensional segregation maps of silicon. A good agreement was found between the segregation profile of silicon in the color etched microstructure and the silicon maps achieved by electron microprobe analysis. However, quantitative silicon investigation was found to be more accurate than color etching results to study the size of the eutectic colonies. - Highlights: • Sensitivity of a color etchant to silicon segregation is quantitatively demonstrated. • Si segregation measurement by EMPA approved the results achieved by color etching. • Color etched micrographs provided data about solidification mechanism in cast irons. • Austenite grain boundaries were identified by measuring the local Si concentration.

  3. Scanning proton microprobe analysis applied to wood and bark samples

    NASA Astrophysics Data System (ADS)

    Lövestam, N. E. G.; Johansson, E.-M.; Johansson, S. A. E.; Pallon, J.

    1990-04-01

    In this study the feasibility of applying scanning micro-PIXE to analysis of wood and bark samples is demonstrated. Elemental mapping of the analysed sections show the patterns of Cl, K, Ca, Mn, Fe, Cu and Zn. Some of these patterns can be related to the annual tree ring structure. It is observed that the variation of elements having an environmental character can be rather large within a single tree ring, thus illuminating possible difficulties when using tree ring sections as a pollution monitor. The variations in elemental concentrations when crossing from bark to wood are also shown to be smooth for some elements but rather abrupt for others.

  4. Quantitative simultaneous multi-element microprobe analysis using combined wavelength and energy dispersive systems

    NASA Technical Reports Server (NTRS)

    Walter, L. S.; Doan, A. S., Jr.; Wood, F. M., Jr.; Bredekamp, J. H.

    1972-01-01

    A combined WDS-EDS system obviates the severe X-ray peak overlap problems encountered with Na, Mg, Al and Si common to pure EDS systems. By application of easily measured empirical correction factors for pulse pile-up and peak overlaps which are normally observed in the analysis of silicate minerals, the accuracy of analysis is comparable with that expected for WDS electron microprobe analyses. The continuum backgrounds are subtracted for the spectra by a spline fitting technique based on integrated intensities between the peaks. The preprocessed data are then reduced to chemical analyses by existing data reduction programs.

  5. The laser microprobe mass analysis technique in the studies of the inner ear.

    PubMed

    Orsulakova, A; Morgenstern, C; Kaufmann, R; D'Haese, M

    1982-01-01

    Laser microprobe mass analysis (LAMMA) has been used to investigate cation and anion concentration in shock frozen, freeze-dried and plastic embedded inner ear tissue. Dissected inner ear specimens were prepared in various media of known ionic compositions and the influence on the K/Na ratio was measured in the lateral cochlea wall (spiral ligament, stria vascularis). For control purposes of the various procedures employed, muscle specimens (external standard) were processed in parallel. It was found that there is a good correlation between the K/Na ratio and the preservation of the tissue fine structure by comparing the results in tissues with different degrees of freezing damage. PMID:6764025

  6. Elemental distribution and sample integrity comparison of freeze-dried and frozen-hydrated biological tissue samples with nuclear microprobe

    NASA Astrophysics Data System (ADS)

    Vavpetič, P.; Vogel-Mikuš, K.; Jeromel, L.; Ogrinc Potočnik, N.; Pongrac, P.; Drobne, D.; Pipan Tkalec, Ž.; Novak, S.; Kos, M.; Koren, Š.; Regvar, M.; Pelicon, P.

    2015-04-01

    The analysis of biological samples in frozen-hydrated state with micro-PIXE technique at Jožef Stefan Institute (JSI) nuclear microprobe has matured to a point that enables us to measure and examine frozen tissue samples routinely as a standard research method. Cryotome-cut slice of frozen-hydrated biological sample is mounted between two thin foils and positioned on the sample holder. The temperature of the cold stage in the measuring chamber is kept below 130 K throughout the insertion of the samples and the proton beam exposure. Matrix composition of frozen-hydrated tissue is consisted mostly of ice. Sample deterioration during proton beam exposure is monitored during the experiment, as both Elastic Backscattering Spectrometry (EBS) and Scanning Transmission Ion Microscopy (STIM) in on-off axis geometry are recorded together with the events in two PIXE detectors and backscattered ions from the chopper in a single list-mode file. The aim of this experiment was to determine differences and similarities between two kinds of biological sample preparation techniques for micro-PIXE analysis, namely freeze-drying and frozen-hydrated sample preparation in order to evaluate the improvements in the elemental localisation of the latter technique if any. In the presented work, a standard micro-PIXE configuration for tissue mapping at JSI was used with five detection systems operating in parallel, with proton beam cross section of 1.0 × 1.0 μm2 and a beam current of 100 pA. The comparison of the resulting elemental distributions measured at the biological tissue prepared in the frozen-hydrated and in the freeze-dried state revealed differences in elemental distribution of particular elements at the cellular level due to the morphology alteration in particular tissue compartments induced either by water removal in the lyophilisation process or by unsatisfactory preparation of samples for cutting and mounting during the shock-freezing phase of sample preparation.

  7. Quantification and local distribution of hydrogen within Zircaloy-4 PWR nuclear fuel cladding tubes at the nuclear microprobe of the Pierre Süe Laboratory from μ-ERDA

    NASA Astrophysics Data System (ADS)

    Raepsaet, C.; Bossis, Ph.; Hamon, D.; Béchade, J. L.; Brachet, J. C.

    2008-05-01

    Hydrogen content and its distribution in in-core materials of nuclear plants are known to have a strong influence on their behaviour, especially on their mechanical properties but also on their corrosion resistance. This point has to be largely investigated in the case of the nuclear fuel cladding (Zr based alloys) of pressurized water reactors (PWR). Two situations have been considered here, with regards to the hydrogen content and its spatial distribution within the thickness of the tubes: Irradiated fuel cladding tubes after a nominal period under working conditions in a PWR core. Non-irradiated fuel cladding previously exposed to conditions representative of an hypothetical "loss of coolant accident" scenario (LOCA). As far as micrometric distributions of H were required, μ-ERDA has been performed at the nuclear microprobe of the Pierre Süe Laboratory. This facility is fitted with two beam lines. In the first one, used for non-active sample analysis, the μ-ERDA configuration has been improved to reduce the limits of detection and the reliability of the results. The second one offers the unique feature of being dedicated to radioactive samples. We will present the nuclear microprobe and emphasize on the μ-ERDA configuration of the two beam lines. We will illustrate the performance of the setup by describing the results obtained for Zircaloy-4 cladding both on non-irradiated and irradiated samples.

  8. Challenge to Electron Microprobe Analysis by Nano-features in Geo-materials

    NASA Astrophysics Data System (ADS)

    Ma, C.; Rossman, G. R.

    2007-12-01

    With current high-resolution analytical scanning electron microscope and transmission electron microscope technology, nano-features (i.e., inclusions, exsolutions, pores) are being discovered in many common geo- materials routinely analyzed by EPMA. Most EPMA instruments have a thermionic electron gun with a tungsten "hairpin" type filament and operate at such high probe currents that they do not produce the high resolution imaging that field emission SEMs do. Such nano-features present difficulties to electron microprobe analysis of the host materials. It is an accuracy issue. Presented here are a few examples. Nano-inclusions like magnetite or pyroxene are common in volcanic glass. Massive rose quartz contains nano-fibers of a dumortierite-related phase that is pink, which is the cause of rose color and optical star effects. Blue quartz has nano-inclusions of ilmenite. Nano-exsolutions and nano-inclusions occur in some feldspars (moonstone and sunstone). Nano- pores in corundum and opals are observed. Thin coatings of nanocrystals on grains of hematite bring Al and P (or As) into the analytical picture. In each of these cases, electron microprobe analyses of host materials were contaminated or affected by the nano-features. For a complete analytical description of a geo-material it is necessary to first examine probe samples under an optical microscope (400× minimum) and a FE-SEM. If the sample contains nano-features, it would then be necessary to combine FIB and TEM-EDS-EELS to comprehensively analyze the host composition.

  9. Nuclear microprobe investigation of the penetration of ultrafine zinc oxide into intact and tape-stripped human skin

    NASA Astrophysics Data System (ADS)

    Szikszai, Z.; Kertész, Zs.; Bodnár, E.; Major, I.; Borbíró, I.; Kiss, Á. Z.; Hunyadi, J.

    2010-06-01

    Ultrafine metal oxides, such as titanium dioxide and zinc oxide are widely used in cosmetic and health products like sunscreens. These oxides are potent UV filters and the small particle size makes the product more transparent compared to formulations containing coarser particles. In the present work the penetration of ultrafine zinc oxide into intact and tape-stripped human skin was investigated using nuclear microprobe techniques, such as proton induced X-ray spectroscopy and scanning transmission ion microscopy. Our results indicate that the penetration of ultrafine zinc oxide, in a hydrophobic basis gel with 48 h application time, is limited to the stratum corneum layer of the intact skin. Removing the stratum corneum partially or entirely by tape-stripping did not cause the penetration of the particles into the deeper dermal layers; the zinc particles remained on the surface of the skin.

  10. PIXE profiling, imaging and analysis using the NAC proton microprobe: Unraveling mantle eclogites

    NASA Astrophysics Data System (ADS)

    van Achterbergh, Esmé; Ryan, Chris G.; Gurney, John J.; Le Roex, Anton P.

    1995-09-01

    The National Accelerator Centre (NAC) proton microprobe has been carefully calibrated by the analysis of pure element, primary steel and geological standards. The results obtained are generally accurate to within 5%. For routine analyses (6-8 min), detection limits in the X-ray energy region 7-20 keV, range from 1.5 to 5 ppm. Previous workers have suggested the use of a (H 2) + beam for semi-quantitative analysis and imaging as higher beam brightness is obtainable with this beam at NAC. However, insufficient suppression of electrons introduces significant analytical error. Only a 3 MeV H + beam has been used for the quantitative analysis reported in this work. A rare suite of xenoliths, consisting of interlayered kyanite-bearing and kyanite-free eclogite, from the Roberts Victor kimberlite, Northern Cape, South Africa, was prepared as polished thin-sections and analyzed by the proton microprobe as a pilot study of trace element signatures in its component minerals (garnet, clinopyroxene and kyanite). The analysis of these eclogites identified significant chemical differences between the minerals of the kyanite-bearing and kyanite-free eclogite. Two clear groupings were distinguished well outside statistical error for Mn, Zn and Zr in garnet, and Mn, Ga, Sr and Ba in the clinopyroxene. Furthermore, clear chemical gradients in the elements Mn, Fe, Zn, Y and Zr were identified in single garnets at the contact between the two eclogite types. True elemental imaging revealed a heterogeneous distribution of the elements Sr and Ba in the clinopyroxene; the presence of Ba is interpreted to indicate the introduction of foreign material. A compositional dependence of the partitioning of Zn between garnet and clinopyroxene was also identified. The data do not contradict a previous hypothesis that the kyanite eclogite zones are the metamorphic products of a plagioclase-rich crystal protolith, but they do challenge the proposal that the layering is a primary feature of the rock

  11. Gaining Precision and Accuracy on Microprobe Trace Element Analysis with the Multipoint Background Method

    NASA Astrophysics Data System (ADS)

    Allaz, J. M.; Williams, M. L.; Jercinovic, M. J.; Donovan, J. J.

    2014-12-01

    Electron microprobe trace element analysis is a significant challenge, but can provide critical data when high spatial resolution is required. Due to the low peak intensity, the accuracy and precision of such analyses relies critically on background measurements, and on the accuracy of any pertinent peak interference corrections. A linear regression between two points selected at appropriate off-peak positions is a classical approach for background characterization in microprobe analysis. However, this approach disallows an accurate assessment of background curvature (usually exponential). Moreover, if present, background interferences can dramatically affect the results if underestimated or ignored. The acquisition of a quantitative WDS scan over the spectral region of interest is still a valuable option to determine the background intensity and curvature from a fitted regression of background portions of the scan, but this technique retains an element of subjectivity as the analyst has to select areas in the scan, which appear to represent background. We present here a new method, "Multi-Point Background" (MPB), that allows acquiring up to 24 off-peak background measurements from wavelength positions around the peaks. This method aims to improve the accuracy, precision, and objectivity of trace element analysis. The overall efficiency is amended because no systematic WDS scan needs to be acquired in order to check for the presence of possible background interferences. Moreover, the method is less subjective because "true" backgrounds are selected by the statistical exclusion of erroneous background measurements, reducing the need for analyst intervention. This idea originated from efforts to refine EPMA monazite U-Th-Pb dating, where it was recognised that background errors (peak interference or background curvature) could result in errors of several tens of million years on the calculated age. Results obtained on a CAMECA SX-100 "UltraChron" using monazite

  12. Application of a nuclear microprobe to the study of calcified tissues

    NASA Astrophysics Data System (ADS)

    Coote, Graeme E.; Vickridge, Ian C.

    1988-03-01

    The mineral fraction of calcified tissue is largely calcium hydroxyapatite (bones and teeth) or calcium carbonate (shells and fish otoliths). Apatite has such a strong affinity for fluoride ions that the F/Ca ratio can vary markedly with position in a bone or tooth, depending on the amount of fluoride present at the time of calcification or partial recrystallization. New biological information can be obtained by introducing extra fluoride into the diet of an animal and using a microprobe later to scan sections of bones or teeth. In suitable burial sites extra fluoride is introduced after death, and the new distribution may have applications in forensic science and archaeology. Fish otoliths are also of interest since a new carbonate layer is formed each day and the distribution of trace elements may record some aspects of the fish's life history. Results from the following studies are presented: fluorine distributions in the teeth of sheep which ingested extra fluoride for known periods; distributions of calcium and fluorine in femurs of rats which drank water high in fluoride for periods from 2 to 15 weeks; calcium and fluorine distributions in artificially-prepared lesions in tooth enamel; diffusion profiles in archaeological human teeth and animal bones; patterns in the strontium/calcium ratio in sectioned otoliths of several species of fish.

  13. Electron Microprobe Analysis of Fe2+/Fe3+ in Minerals With low Total Iron Concentrations

    NASA Astrophysics Data System (ADS)

    Creighton, S. D.; Matveev, S.; Stachel, T.; Luth, R. W.

    2004-12-01

    method, we have been able to precisely measure ferric iron concentrations of less than 1 wt.% in mantle-derived pyrope garnets with true microprobe spatial resolution. The accuracy of the flank method is currently being verified with spectrophotometric wet-chemical analysis of ferric iron in pyrope garnet standards. References Höfer, H.E., Brey, G.P., Schulz-Dobrick, B., and Oberhänsli, R., 1994. Eur. J. Min., 6: 407-418

  14. The osmotic behaviour of toad skin epithelium (Bufo viridis). an electron microprobe analysis.

    PubMed

    Rick, R; Dörge, A; Katz, U; Bauer, R; Thurau, K

    1980-05-01

    The effect of saline adaptation on the intracellular Na, K, Cl, P concentrations and dry weight content of the toad skin epithelium (Bufo viridis) was studied using the technique of electron microprobe analysis. The measurements were performed on isolated abdominal skins either directly after dissection or after additional incubation in Ussing-type chambers. Adaptations of the toads to increasing NaCl concentrations for 7 days resulted in increased blood plasma osmolarity and a parallel increase in the cellular electrolyte, P and dry weight concentrations of the epithelium, the K increase representing the most significant fraction of the intracellular osmolarity increase. No evidence was obtained to show that the nucleus and cytoplasm reacted differently from each other and all living epithelial cell types basically showed the same response. Incubation of the isolated skins under control conditions showed a drastic inhibition of the transepithelial Na transport after adaptation to high salinities. In spite of the large variations in the transport rate almost identical intracellular electrolyte concentrations were observed. In tap water adapted toads the average cellular concentrations were 8.8 mmole/kg wet weight for Na, 109.6 for K, 41.5 for Cl, and 135.3 for P, respectively. Incubation of the skin with Ringer's solution of different osmolarities demonstrated that the epithelial cells are in osmotic equilibrium with the inner bathing solution. The results are consistent with the view that the osmotic adaptation is mainly accomplished by the movement of water. PMID:7191092

  15. Boron analysis by electron microprobe using MoB4C layered synthetic crystals

    USGS Publications Warehouse

    McGee, J.J.; Slack, J.F.; Herrington, C.R.

    1991-01-01

    Preliminary electron microprobe studies of B distribution in minerals have been carried out using MoB4C-layered synthetic crystals to improve analytical sensitivity for B. Any microprobe measurements of the B contents of minerals using this crystal must include analyses for Cl to assess and correct for the interference of Cl X-rays on the BK?? peak. Microprobe analyses for B can be made routinely in tourmaline and other B-rich minerals, and minor B contents also can be determined in common rock-forming minerals. Incorporation of unusually high B contents in minerals other than borosilicates has been discovered in prograde and retrograde minerals in tourmalinites from the Broken Hill district, Australia, and may reflect high B activities produced during the metamorphism of tourmaline-rich rocks. -from Authors

  16. Phosphate concentration and association as revealed by sequential extraction and microprobe analysis: The case of sediments from two Argentinean reservoirs

    NASA Astrophysics Data System (ADS)

    Borgnino, L.; Orona, C.; Avena, M.; Maine, M. A.; RodríGuez, A.; de Pauli, C. P.

    2006-01-01

    This article reports the general characteristics of the sediments of two Argentinean reservoirs, which are used for water supply. The chemical composition, granulometry, and specific surface area are presented together with a study of total phosphate concentration and phosphate association by combining sequential extraction and microprobe analysis. In general, the sediments of both reservoirs have similar characteristics. Sequential extraction reveals that the main P fractions in the studied sediments are Ca-bound phosphate in river mouths and Fe-bound phosphate in the rest of the reservoir stations. Microprobe analysis appears to be an important complementary technique to sequential extraction. Combined with chemical fractionation and specific surface area measurements, these analyses indicate that Ca-bound phosphate is mainly distributed within grains or particles highly concentrated in Ca and P, whereas Fe-bound phosphate is rather homogeneously distributed in the sediments at the surface of fine particles. Microprobe analyses also revealed an important coating of phyllosilicate surfaces with Fe (hydr)oxides, which explains the good correlation found between Fe-bound phosphate, clay fraction, and specific surface area. The role of sediments as a potential source of phosphate is discussed in terms of P association in the solid phase and dissolved oxygen concentration profiles in the water column.

  17. The application of a synchrotron radiation microprobe to trace element analysis

    SciTech Connect

    Gordon, B.M.; Hanson, A.L.; Jones, K.W.; Kwiatek, W.M.; Long, G.J.; Pounds, J.G.; Schidlovsky, G.; Spanne, P.; Rivers, M.L.; Sutton, S.R.

    1987-01-01

    Synchrotron radiation is light emitted by electrons when accelerated in a circular orbit. Properties of synchrotron radiation important to trace element analysis by x-ray fluorescence analysis include a broad, continuous and tunable energy spectrum for K- and L-shell excitation of all elements; a linearly polarized source reducing the scattered radiation backgrounds; low energy deposition in the target; and an appreciable flux in narrow energy bandwidths for chemical speciation. Experiments to date have generally used ''white'' continuous spectra with a low energy absorber and no focussing, but future runs will use focussing mirrors which increase intensities by a factor of more than 1000. Monochromators will be used to select the energy and bandwidths appropriate to the experiment. Detection limits for thin biomedical samples using a solid-state detector, a 0.5 mm beam and a 5 min counting interval were in the range of 30 ppB for calcium to 50 ppB for zinc. A prototype wet cell was designed, constructed and tested using cat cardiac myocytes with the result that major trace elements such as iron could be quantitated in single myocytes. The x-ray microprobe was used to localize gallium in fetal rat bone explants after being cultured in BGJ media containing 25 ..mu..M Ga(NO/sub 3/)/sub 3/. The high brightness of x rays from a synchrotron source makes possible the development of computerized tomography on a micrometer scale. A tomogram of a freeze-dried caterpillar head was produced in a 50 min scan. The pixel size was 30 ..mu..m using a 20-..mu..m beam. 2 refs., 1 fig.

  18. Ion microprobe U-Pb dating and strontium isotope analysis of biogenic apatite

    NASA Astrophysics Data System (ADS)

    Sano, Y.; Toyoshima, K.; Takahata, N.; Shirai, K.

    2012-12-01

    Conodonts are micro-fossils chemically composed of apatite which occurred in the body of one animal. They are guide fossils to show formation ages of sedimentary sequences with the highest resolution [1] and good samples to verify the dating method. We developed the ion microprobe U-Pb dating of apatite [2] and applied the method to a Carboniferous conodont [3] by using a SHRIMP II installed at Department of Earth and Planetary Sciences, Hiroshima University. Recently we have developed the NanoSIMS U-Pb dating method and successfully measured the formation ages of monazite [4] and zircon [5] at Atmosphere and Ocean Research Institute, University of Tokyo. In this work we carried out the NanoSIMS U-Pb dating of biogenic apatite such as conodont. Since the spot size of NanoSIMS is smaller than SHRIMP II, it is easier to have multi-spots on the single fragment of biogenic apatite. Based on the isochron method of U-Pb system, we have calculated the formation ages. They are consistent with those in literature. In order to study the chemical evolution of ocean during the past 600 Million years, strontium isotopes (87Sr/86Sr) of fossil marine carbonate such as coral skeletons and foraminifera tests were measured and compiled [6]. However they are not robust when the age is older than 500Ma, partly due to post-depositional histories. Apatite is more stable and more resistant to the alteration than carbonate [7]. Recently we have developed the method of NanoSIMS strontium isotopic analysis of a fish otolith, which composed of aragonite [8]. In this work we carried out the strontium isotopic analysis of biogenic apatite. The advantage of the ion microprobe technique over the TIMS (thermal ionization mass spectrometer) and MC-ICP-MS (multi-collector inductively coupled argon plasma mass spectrometer) method is preservation of the important textural context and to provide an opportunity for other simultaneous analytical work with high spatial resolution. This is the case for

  19. On the analysis of neonatal hamster tooth germs with the photon microprobe at Daresbury, UK

    NASA Astrophysics Data System (ADS)

    Tros, G. H. J.; Van Langevelde, F.; Vis, R. D.

    1990-04-01

    Complementary to the micro-PIXE experiments performed on hamster tooth germs to elucidate the role of fluoride during the growth, the photon microprobe at Daresbury was used to obtain information on the distribution of Zn. The germs of fluoride-administered hamsters, together with a control group, were analyzed with the micro-synchrotron radiation fluorescence method (micro-SXRF).

  20. Exploratory nuclear microprobe data visualisation using 3- and 4-dimensional biological volume rendering tools

    NASA Astrophysics Data System (ADS)

    Whitlow, Harry J.; Ren, Minqin; van Kan, Jeroen A.; Watt, Frank; White, Dan

    2007-07-01

    The emergence of Confocal Microscopy (CM) and Atomic Force Microscopy (AFM) as everyday tools in cellular level biology has stimulated development of 3D data visualisation software. Conventional 2-dimensional images of cell (optical) sections obtained in a transmission electron or optical microscopes and more sophisticated multidimensional imaging methods require processing software capable of 3D rendering and mathematically transforming data in 3-, 4-, or more dimensions. The richness of data obtained from the different nuclear microscopy imaging techniques and often parallel information channels (X-ray, secondary electron, Scanning Transmission Ion Microscopy) is often not obvious because subtleties and interrelations in the data could not be rendered in a human interpretable way. In this exploratory study we have applied the BioImageXD software, originally developed for rendering of multidimensional CM data, to some different nuclear microscopy data. Cells-on-Silicon STIM data from a human breast cancer cell line and elemental maps from lesions on rabbit aorta have been visualised. Mathematical filtering and averaging combined with hardware accelerated 3D rendering enabled dramatically clear visualisation of inter-cellular regions comprising extra cellular matrix proteins that were otherwise difficult to visualise, and also sub cellular structures. For elemental mapping, the use of filtered correlation surfaces and colour channels clearly revealed the interrelations in the data structures that are not easily discernible in the PIXE elemental maps.

  1. Trace elemental analysis of bituminuos coals using the Heidelberg proton microprobe

    USGS Publications Warehouse

    Chen, J.R.; Kneis, H.; Martin, B.; Nobiling, R.; Traxel, K.; Chao, E.C.T.; Minkin, J.A.

    1981-01-01

    Trace elements in coal can occur as components of either the organic constituents (macerals) or the inorganic constituents (minerals). Studies of the concentrations and distribution of the trace elements are vital to understanding the geochemical millieu in which the coal was formed and in evaluating the attempts to recover rare but technologically valuable metals. In addition, information on the trace element concentrations is important in predicting the environmental impact of burning particular coals, as many countries move toward greater utilization of coal reserves for energy production. Traditionally, the optical and the electron microscopes and more recently the electron microprobe have been used in studying the components of coal. The proton-induced X-ray emission (PIXE) microprobe offers a new complementary approach with an order of magnitude or more better minimum detection limit. We present the first measurements with a PIXE microprobe of the trace element concentrations of bituminous coal samples. Elemental analyses of the coal macerals-vitrinite, exinite, and inertinite-are discussed for three coal samples from the Eastern U.S.A., three samples from the Western U.S.A., and one sample from the Peoples Republic of China. ?? 1981.

  2. Electron microprobe analysis of frog skin epithelium: evidence for a syncytial sodium transport compartment.

    PubMed

    Rick, R; Dörge, A; von Arnim, E; Thurau, K

    1978-03-20

    For elucidation of the functional organization of frog skin epithelium with regard to transepithelial Na transport, electrolyte concentrations in individual epithelial cells were determined by electron microprobe analysis. The measurements were performed on 1-micron thick freeze-dried cryosections by an energy-dispersive X-ray detecting system. Quantification of the electrolyte concentrations was achieved by comparing the X-ray intensities obtained in the cells with those of an internal albumin standard. The granular, spiny, and germinal cells, which constitute the various layers of the epithelium, showed an identical behavior of their Na and K concentrations under all experimental conditions. In the control, both sides of the skin bathed in frog Ringer's solution, the mean cellular concentrations (in mmole/kg wet wt) were 9 for Na and 118 for K. Almost no change in the cellular Na occurred when the inside bathing solution was replaced by a Na-free isotonic Ringer's solution, whereas replacing the outside solution by distilled water resulted in a decrease of Na to almost zero in all layers. Inhibition of the transepithelial Na transport by ouabain (10(-4) M) produced in increase in Na to 109 and a decrease in K to 16. The effect of ouabain on the cellular Na and K concentrations was completely cancelled when the Na influx from the outside was prevented, either by removing Na or adding amiloride (10(-4) M). When, after the action of ouabain, Na was removed from the outside bathing solution, the Na and K concentration in all layers returned to control values. The latter effect could be abolished by amiloride. The other cell types of the epithelium showed under some experimental conditions a different behavior. In the cornified cells and the light cells, which occurred occasionally in the stratum granulosum, the electrolyte concentrations approximated those of the outer bathing medium under all experimental conditions. In the mitochondria-rich cells, the Na influx

  3. Ion microprobe magnesium isotope analysis of plagioclase and hibonite from ordinary chondrites

    NASA Technical Reports Server (NTRS)

    Hinton, R. W.; Bischoff, A.

    1984-01-01

    Ion and electron microprobes were used to examine Mg-26 excesses from Al-26 decay in four Al-rich objects from the type 3 ordinary hibonite clast in the Dhajala chondrite. The initial Al-26/Al-27 ratio was actually significantly lower than Al-rich inclusions in carbonaceous chondrites. Also, no Mg-26 excesses were found in three plagioclase-bearing chondrules that were also examined. The Mg-26 excesses in the hibonite chondrites indicated a common origin for chondrites with the excesses. The implied Al-26 content in a proposed parent body could not, however, be confirmed as a widespread heat source in the early solar system.

  4. Cometary and interstellar dust grains - Analysis by ion microprobe mass spectrometry and other techniques

    NASA Astrophysics Data System (ADS)

    Zinner, E.

    1991-04-01

    A survey of microanalytical measurements on interplanetary dust particles (IDPs) and interstellar dust grains from primitive meteorites is presented. Ion-microprobe mass spectrometry with its capability to determine isotopic compositions of many elements on a micron spatial scale has played a special role. Examples are measurements of H, N, and O isotopes and refractory trace elements in IDPs; C, N, Mg, and Si isotopes in interstellar SiC grains; and C and N isotopes and H, N, Al, and Si concentrations in interstellar graphite grains.

  5. Ion microprobe mass analysis of plagioclase from 'non-mare' lunar samples

    NASA Technical Reports Server (NTRS)

    Meyer, C., Jr.; Anderson, D. H.; Bradley, J. G.

    1974-01-01

    The ion microprobe was used to measure the composition and distribution of trace elements in lunar plagioclase, and these analyses are used as criteria in determining the possible origins of some nonmare lunar samples. The Apollo 16 samples with metaclastic texture and high-bulk trace-element contents contain plagioclase clasts with extremely low trace-element contents. These plagioclase inclusions represent unequilibrated relicts of anorthositic, noritic, or troctolitic rocks that have been intermixed as a rock flour into the KREEP-rich matrix of these samples. All of the plagioclase-rich inclusions which were analyzed in the KREEP-rich Apollo 14 breccias were found to be rich in trace elements. This does not seem to be consistent with the interpretation that the Apollo 14 samples represent a pre-Imbrium regolith, because such an ancient regolith should have contained many plagioclase clasts with low trace-element contents more typical of plagioclase from the pre-Imbrium crust. Ion-microprobe analyses for Ba and Sr in large plagioclase phenocrysts in 14310 and 68415 are consistent with the bulk compositions of these rocks and with the known distribution coefficients for these elements. The distribution coefficient for Li (basaltic liquid/plagioclase) was measured to be about 2.

  6. High resolution imaging and elemental analysis of PAGE electrophoretograms by scanning proton microprobe

    NASA Astrophysics Data System (ADS)

    Szőkefalvi-Nagy, Z.; Kocsonya, A.; Kovács, I.; Hopff, D.; Lüthje, S.; Niecke, M.

    2009-06-01

    Metal content of metalloproteins can be detected and even quantified by the PIXE-PAGE method. In this technique the proteins are separated by thin layer electrophoresis (by polyacrylamide gel electrophoresis (PAGE) in most cases) and the properly dried gel sections are analyzed by PIXE using "band-shaped" proton milli-beam. This PIXE-PAGE method was adapted for our scanning proton microprobe. The microPIXE-PAGE version provides two-dimensional elemental mapping of the protein bands. In addition, the fast continuous scanning reduces the risk of the thermal deterioration of the sample and the X-ray contribution from dust-impurities can be filtered out in the data evaluation process.

  7. Imaging and spectroscopic analysis of single microdroplets containing p-cresol using the near-infrared laser tweezers/Raman microprobe system

    NASA Astrophysics Data System (ADS)

    Ajito, Katsuhiro; Morita, Masao

    1999-06-01

    The near-infrared (NIR) laser tweezers/Raman microprobe system features two charge-coupled device (CCD) cameras with holographic notch filters (HNFs) for the imaging and spectroscopic analysis of molecules in a single microdroplet (MD). One CCD camera and a HNF are used to record an image of the laser microprobe in a trapped MD. The other CCD camera and two HNFs are used with a polychromator to obtain a Raman spectrum of molecules in the MD. A dielectric multilayer coated beam splitter divides the scattered NIR light into two optical paths for the cameras. The system provides sufficient sensitivity to obtain a Raman spectrum of p-cresol contained in a single picoliter toluene MD and sufficient spatial resolution to record an image of the laser microprobe in a trapped MD simultaneously. Furthermore, a difference in the solubility for the p-cresol in bulk solvent and in the MD solvent was clearly observed using this system.

  8. A study of the behavior of bromide in artificial pits using in situ X-ray microprobe analysis

    SciTech Connect

    Isaacs, H.S.; Kaneko, M.

    1997-12-31

    An in situ X-ray microprobe analysis of Type 316 stainless steel artificial pits has been carried out with a bromide/chloride solution. A high intensity 8 micron diameter polychromatic X-ray beam was scanned across the steel solution interface within the artificial pit. The resulting X-ray fluorescence was analyzed using an energy dispersive X-ray detector. In contrast to the light Cl atom, Br could be detected, making it possible to monitor the behavior of halides in the artificial pits and in the salt layer at the interface. It was found that Br was more active than Cl. At high potentials, elemental Br was produced as an oxidation product, whereas without added bromide, chloride only formed a salt layer. Br also concentrated at the salt steel interface at potentials below where it was oxidized.

  9. Experimental and numerical analysis of the temperature distribution of injection molded products using protruding microprobes

    NASA Astrophysics Data System (ADS)

    Liu, Shih-Jung; Ho, Chia-Wei

    2011-05-01

    Injection molding has been one of the most important polymer processing methods for manufacturing plastic parts. In the process, the temperature is an important parameter that influences process features such as cycle times, crystallization rates, degree of crystallinity, melt flow properties, and molded product qualities. This study aims to, experimentally and numerically, examine the three-dimensional temperature distribution along the melt flow path of injection molded parts. A special experimental set-up, which includes an injection mold equipped with protruding microprobes for guiding embedded thermocouples, was designed and built to measure the temperature field along the flow path, i.e., inside the runner and the cavity, of injection molded products. The experimental results suggested that the disturbance induced by the probes remained negligible and precise temperature profiles could be measured at various positions inside the cavity. A significant increase of melt temperature was found to result from the viscous dissipation of the polymeric materials in the runner. Additionally, a commercially available code was employed to simulate and predict the temperature variation in injection molded parts. It was shown that the numerical simulation predicted better the temperature distributions inside the cavity than those along the runner.

  10. Detection of graphite using laser microprobe mass analysis of a transbronchial biopsy from a foundry worker with mixed dust pneumoconiosis.

    PubMed

    Domej, Wolfgang; Földes-Papp, Zeno; Schlagenhaufen, Claudia; Wippel, Ruediger; Tilz, Gernot Peter; Krachler, Michael; Demel, Ulrike; Lang, Johanna; Urban-Woltron, Hildegard

    2002-03-28

    Inhalation of dust containing graphite can cause lung disease in foundry workers and workers in graphite mines or mills. Mixed dust pneumoconiosis caused by long-term occupational exposure to graphite dust is a rare disease. Only a few cases of graphite pneumoconiosis have been reported in literature, and these were usually diagnosed post mortem. Our report is of an 80-year-old male patient who had worked in an iron foundry for 20 years and whose work had entailed regular contact with ground graphite and foundry vapors. Chest x-rays revealed both a reticular and nodular pattern in the lung, moderate apical distractions and pleural scarring, all of which were confirmed by high-resolution computed tomography. Bronchoalveolar lavage and transbronchial biopsies were also consistent with mixed dust pneumoconiosis, and due to the long-term dust exposure, graphite pneumoconiosis was strongly suspected. To confirm this diagnosis, the chemical composition of the dark granules in the semi-thin histological sections of the transbronchial biopsies were analyzed using laser microprobe mass spectroscopy. The mass spectra of these black particles were consistent with those of natural graphite powder. Comparative analyses of normal lung tissue did not produce similar spectral patterns. We conclude that histology and cytology does not always suffice to confirm a diagnosis of graphite pneumoconiosis, because black particles are also found in conditions resulting from other exposures, such as heavy smoking or coal mining. Analysis of the composition of particles deposited in the lung tissue offers more precise information, which can be used as evidence in occupational and forensic medicine. Laser microprobe mass spectroscopy can assess the mineral dust load in lung samples. PMID:12238312

  11. Analysis for chemical characterization of atmospheric aerosols application of X-ray microprobe system and double thin film method.

    PubMed

    Tohno, Susumu; Ma, Chang-Jin; Hayakawa, Shinjiro; Yamasaki, Satoshi; Kasahara, Mikio

    2006-09-01

    The X-ray microprobe system was applied to ultra trace characterization of single Kosa aerosols and non-Kosa aerosols simultaneously collected at Yasaka, Japan and TaeAnn, Korea. We demonstrated remarkable mass increase of heavy metals as well as soil components in individual particles during the Kosa event compared with the non-Kosa period at Yasaka. Backward trajectory analysis suggested that the Kosa samples were in the mixing state of mineral components and anthropogenic heavy elements. Double thin film method was applied to investigate the seasonal change of the mixing states of single sea-salt aerosols associated with chlorine loss due to the heterogeneous reactions between sea-salt particles and acidic gases. It was revealed that the percentages of both chloride-nitrate mixed particles and sulfate-nitrate ones were larger in wintertime than those in summertime and fraction of chloride-nitrate mixed particles increased with an increase of particle size. Comparison between the size-segregated bulk analysis and the single particle analysis demonstrated that remarkable chloride depletion occurred in coarse particles sampled on May in the former analysis, while chloride depletion in coarse particles was not marked in the latter analysis. The discrepancy attributes to the difference of the sampling time between both analyses because significant change of air mass route occurred during the bulk sampling after completion of the single particle sampling. PMID:16741794

  12. PROTON MICROPROBE ANALYSIS OF TRACE-ELEMENT VARIATIONS IN VITRINITES IN THE SAME AND DIFFERENT COAL BEDS.

    USGS Publications Warehouse

    Minkin, J.A.; Chao, E.C.T.; Blank, Herma; Dulong, F.T.

    1987-01-01

    The PIXE (proton-induced X-ray emission) microprobe can be used for nondestructive, in-situ analyses of areas as small as those analyzed by the electron microprobe, and has a sensitivity of detection as much as two orders of magnitude better than the electron microprobe. Preliminary studies demonstrated that PIXE provides a capability for quantitative determination of elemental concentrations in individual coal maceral grains with a detection limit of 1-10 ppm for most elements analyzed. Encouraged by the earlier results, we carried out the analyses reported below to examine trace element variations laterally (over a km range) as well as vertically (cm to m) in the I and J coal beds in the Upper Cretaceous Ferron Sandstone Member of the Mancos Shale in central Utah, and to compare the data with the data from two samples of eastern coals of Pennsylvanian age.

  13. Use of electron microprobe x-ray analysis for determination of low calcium concentrations across leaves deficient in calcium

    NASA Technical Reports Server (NTRS)

    Barta, D. J.; Tibbitts, T. W.

    1991-01-01

    An electron microprobe with wavelength-dispersive x-ray spectrometry (WDS) was found to be useful for the determination of Ca concentrations in leaf tissue deficient in Ca. WDS effectively detected Ca concentrations as low as 0.2 mg/g dry wt in the presence of high levels of K and Mg (120 and 50 mg/g dry wt, respectively). Leaf specimens were prepared for analysis by quick-freezing in liquid nitrogen and freeze-drying at -20 degrees C to maintain elemental integrity within the tissue. Because dry material was analyzed, sample preparation was simple and samples could be stored for long periods before analysis. A large beam diameter of 50 gm was used to minimize tissue damage under the beam and analyze mineral concentrations within several cells at one time. Beam penetration was between 50 and 55 microns, approximately one-third of the thickness of the leaf. For analysis of concentrations in interveinal areas, analyses directed into the abaxial epidermis were found most useful. However, because of limited beam penetration, analyses of veinal areas would require use of cross sections [correction of crosssections]. Solid mineral standards were used for instrument standardization. To prevent measurement errors resulting from differences between the matrix of the mineral standards and the analyzed tissue, concentrations in leaves were corrected using gelatin standards prepared and analyzed under the same conditions. WDS was found to be useful for documenting that very low Ca levels occur in specific areas of lettuce leaves exhibiting the Ca deficiency injury termed tipburn.

  14. Ion microprobe analysis of oxygen isotope ratios in granulite facies magnetites: diffusive exchange as a guide to cooling history

    NASA Astrophysics Data System (ADS)

    Valley, John W.; Graham, Colin M.

    1991-03-01

    Ion microprobe analysis of magnetites from the Adirondack Mountains, NY, yields oxygen isotope ratios with spatial resolution of 2 8 μm and precision in the range of 1‰ (1 sigma). These analyses represent 11 orders of magnitude reduction in sample size compared to conventional analyses on this material and they are the first report of routinely reproducible precision in the 1 per mil range for analysis of δ18O at this scale. High precision micro-analyses of this sort will permit wide-ranging new applications in stable isotope geochemistry. The analyzed magnetites form nearly spherical grains in a calcite matrix with diopside and monticellite. Textures are characteristic of granulite facies marbles and show no evidence for retrograde recrystallization of magnetite. Magnetites are near to Fe3O4 in composition, and optically and chemically homogeneous. A combination of ion probe plus conventional BrF5 analysis shows that individual grains are homogeneous with δ18O=8.9±1‰ SMOW from the core to near the rim of 0.1 1.2 mm diameter grains. Depth profiling into crystal growth faces of magnetites shows that rims are 9‰ depleted in δ18O. These low δ18O values increase in smooth gradients across the outer 10 μm of magnetite rims in contact with calcite. These are the sharpest intracrystalline gradients measured to date in geological materials. This discovery is confirmed by bulk analysis of 150 350 μm diameter magnetites which average 1.2‰ lower in δ18O than coarse magnetites due to low δ18O rims. Conventional analysis of coexisting calcite yields °18O=18.19, suggesting that bulk Δ18O (Cc-Mt)=9.3‰ and yielding an apparent equilibration “temperature” of 525° C, over 200° C below the temperature of regional metamorphism. Consideration of experimental diffusion data and grain size distribution for magnetite and calcite suggests two contrasting cooling histories. The data for oxygen in calcite under hydrothermal conditions at high P(H2O) indicates that

  15. Electron microprobe analysis of human labial gland secretory granules in cystic fibrosis

    SciTech Connect

    Izutsu, K.; Johnson, D.; Schubert, M.; Wang, E.; Ramsey, B.; Tamarin, A.; Truelove, E.; Ensign, W.; Young, M.

    1985-06-01

    X-ray microanalysis of freeze-dried labial gland cryosections revealed that Na concentration was doubled and the Ca/S concentration ratio was decreased in secretory granules of labial glands from patients with cystic fibrosis (CF) when compared with glands from normal subjects. Other results suggested that the decrease in the Ca/S concentration ratio resulted from an increase in S concentration. These findings imply that mucous granules in labial saliva showed a CF-related increase in Na and S content, and such changes would be expected to affect the rheology of the mucus after exocytosis. In contrast with a previous study in human parotid glands, no evidence was found for CF-related changes in cytoplasmic or nuclear Na, K, and Ca concentrations. Significant elemental differences were found between secretory granules and nuclei and cytoplasm of control cells.

  16. Nuclear Analysis

    NASA Technical Reports Server (NTRS)

    Clement, J. D.; Kirby, K. D.

    1973-01-01

    Exploratory calculations were performed for several gas core breeder reactor configurations. The computational method involved the use of the MACH-1 one dimensional diffusion theory code and the THERMOS integral transport theory code for thermal cross sections. Computations were performed to analyze thermal breeder concepts and nonbreeder concepts. Analysis of breeders was restricted to the (U-233)-Th breeding cycle, and computations were performed to examine a range of parameters. These parameters include U-233 to hydrogen atom ratio in the gaseous cavity, carbon to thorium atom ratio in the breeding blanket, cavity size, and blanket size.

  17. Laser Microprobe Mass Spectrometry 1: Basic Principles and Performance Characteristics.

    ERIC Educational Resources Information Center

    Denoyer, Eric; And Others

    1982-01-01

    Describes the historical development, performance characteristics (sample requirements, analysis time, ionization characteristics, speciation capabilities, and figures of merit), and applications of laser microprobe mass spectrometry. (JN)

  18. Hydrogen incorporation into high temperature protonic conductors: Nuclear microprobe microanalysis by means of 1H(p, p) 1H scattering

    NASA Astrophysics Data System (ADS)

    Berger, P.; Gallien, J.-P.; Khodja, H.; Daudin, L.; Berger, M.-H.; Sayir, A.

    2006-08-01

    Protonic conductivity of some solid state materials at an intermediate temperature range (400-600 °C), referred as high temperature protonic conductor (HTPC), suggests their application as electrolytes in electrochemical cells, batteries, sensors, etc. Among them, some perovskites can be protonic and electronic conductors. Several obstacles remain to achieve the full potential of these ceramic membranes, among them the lack of measurement techniques and of an unambiguous model for conductivity. A precise understanding of the transport mechanisms requires local profiling of hydrogen concentrations within the microstructure of the ceramic. We have used the nuclear microprobe of the Laboratoire Pierre SÜE to investigate quantitatively the spatial distribution of hydrogen after water heat treatment of textured perovskites, SrCe0.9Y0.1O3-δ and Sr3Ca1+xNb2-xO9-δ, x = 0.18, synthesized according to a melt-process developed at NASA GRC. A not very common method has been developed for hydrogen measurements in thin samples, 1H(p, p)1H elastic recoil coincidence spectrometry (ERCS). Early experiments have evidenced hydrogen concentration enhancement within grain boundaries.

  19. Chemical and Isotopic Analysis of Trace Organic Matter on Meteorites and Interstellar Dust Using a Laser Microprobe Instrument

    NASA Technical Reports Server (NTRS)

    Zare, Richard N.; Boyce, Joseph M. (Technical Monitor)

    2001-01-01

    Polycyclic Aromatic Hydrocarbons (PAHs) are of considerable interest today because they are ubiquitous on Earth and in the interstellar medium (ISM). In fact, about 20% of cosmic carbon in the galaxy is estimated to be in the form of PAHs. Investigation of these species has obvious uses for determining the cosmochemistry of the solar system. Work in this laboratory has focused on four main areas: 1) Mapping the spatial distribution of PAHs in a variety of meteoritic samples and comparing this distribution with mineralogical features of the meteorite to determine whether a correlation exists between the two. 2) Developing a method for detection of fullerenes in extraterrestrial samples using microprobe Laser Desorption Ionization Mass Spectroscopy and utilizing this technique to investigate fullerene presence, while exploring the possibility of spatially mapping the fullerene distribution in these samples through in situ detection. 3) Investigating a possible formation pathway for meteoritic and ancient terrestrial kerogen involving the photochemical reactions of PAHs with alkanes under prebiotic and astrophysically relevant conditions. 4) Studying reaction pathways and identifying the photoproducts generated during the photochemical evolution of PAH-containing interstellar ice analogs as part of an ongoing collaboration with researchers at the Astrochemistry Lab at NASA Ames. All areas involve elucidation of the solar system formation and chemistry using microprobe Laser Desorption Laser Ionization Mass Spectrometry. A brief description of microprobe Laser Desorption Ionization Mass Spectroscopy, which allows selective investigation of subattomole levels of organic species on the surface of a sample at 10-40 micrometer spatial resolution, is given.

  20. New X-ray microprobe system for trace heavy element analysis using ultraprecise X-ray mirror optics of long working distance

    NASA Astrophysics Data System (ADS)

    Terada, Yasuko; Yumoto, Hirokatsu; Takeuchi, Akihisa; Suzuki, Yoshio; Yamauchi, Kazuto; Uruga, Tomoya

    2010-05-01

    A new X-ray microprobe system for trace heavy element analysis using ultraprecise X-ray mirror optics of 300 mm long working distance has been developed at beamline 37XU of SPring-8. A focusing test has been performed in the X-ray energy range 20-37.7 keV. A focused beam size of 1.3 μm ( V)×1.5 μm ( H) has been achieved at an X-ray energy of 30 keV, and a total photon flux of the focused beam was about 2.7×10 10 photons/s. Micro-X-ray fluorescence (μ-XRF) analysis of eggplant roots has been carried out using the developed microprobe. It is clearly observed in the XRF images that cadmium is highly accumulated in the endodermis, exodermis and epidermis of roots. This study demonstrates the potential of scanning microscopy for heavy elements analysis in the high-energy X-ray region.

  1. Micro-fluidics and integrated optics glass sensor for in-line micro-probing of nuclear samples

    SciTech Connect

    Schimpf, A.; Bucci, D.; Broquin, J.E.; Canto, F.; Magnaldo, A.; Couston, L.

    2012-08-15

    We study the miniaturization of Thermal Lens Spectrometry (TLS) towards Lab-on-chip integration in order to reduce the volume of fluid assays in nuclear process control. TLS is of great interest in this context since it combines the advantages of optical detection methods with an inherent suitability for small-scale samples. After validating the experimental principle in a classical thermal lens crossed-beam setup, we show the integration of a Young-interferometer with a microcapillary on a glass substrate, reducing the necessary sample size to 400 nl. The interferometer translates the photo-thermally induced refractive index change in the fluid to a phase shift of the fringe pattern, which can then be detected by a camera. Measurements of Co(II) in ethanol yield a detection limit of c = 5 x 10{sup -4} M for the crossed-beam setup and c = 6 x 10{sup -3} M for the integrated sensor. At an interaction length of 10 m, it detects a minimum absorbance of K = 1.2 x 10{sup -4} in a probed volume of 14 pl. (authors)

  2. Nuclear microprobe investigation into the trace elemental contents of carotid artery walls of apolipoprotein E deficient mice

    NASA Astrophysics Data System (ADS)

    Minqin, Ren; En, Huang; Beck, Konstanze; Rajendran, Reshmi; Wu, Ben J.; Halliwell, Barry; Watt, Frank; Stocker, Roland

    2007-07-01

    Atherosclerosis is a progressive disease that causes lesions in large and medium-sized arteries. There is increasing evidence that the function of vascular endothelial cells is impaired by oxidation reactions, and that metal ions may participate in these processes. The nuclear microscopy facility in NUS, which has the ability to focus a 2 MeV proton beam down to sub micron spot sizes, was used to investigate the trace elemental changes (e.g. Zn and Fe) in atherosclerotic lesions in the common carotid artery of apolipoprotein E deficient mice fed a high fat diet. In this preliminary study, which is part of a larger study to investigate the effects of probucol on carotid artery atherosclerosis, two sets of mice were used; a test set fed a high fat diet +1% probucol, and a control set which was fed a high fat diet only. The results show that the Zn/Fe ratio was significantly higher in the media of arteries of probucol treated animals without overlying lesion (4.3) compared to the media with overlying lesion (1.3) ( p = 0.004) for test mice. For the control mice, the arterial Zn/Fe ratio was 1.8 for media without overlying lesion, compared with 1.0 for media with overlying lesion ( p = 0.1). Thus, for media without overlying lesion, the Zn/Fe ratio was significantly higher ( p = 0.009) in probucol-treated (4.3) than control mice (1.8), whereas there was little difference in the ratios between the two groups in media with overlying lesion (1.3 compared with 1.0). These preliminary results are consistent with the idea that the levels of iron and zinc concentrations within the artery wall may influence the formation of atherosclerotic plaque in the carotid artery.

  3. Analysis of solids with a secondary-neutral microprobe based on electron-gas post-ionization.

    PubMed

    Bieck, W; Gnaser, H; Oechsner, H

    1995-10-01

    The detection sensitivity and the lateral resolution in electron-gas SNMS have been improved in a newly developed secondary-neutral microprobe. This instrument combines the high post-ionization efficiency provided by the electron component of an rf-plasma (post-ionization probability alpha(0) of some 10(-2)) with a high-transmission magnetic mass spectrometer. Using the plasma as an effective primary ion source, secondary-neutral intensities of up to 10(9) cps can be realized for 1 keV Ar(+) ion bombardment and a primary current density of 1 mA/cm(2). To obtain laterally resolved secondary-neutral micrographs, a 20 keV-Ga(+)-ion beam produced in a liquid-metal ion source (LMIS) is utilized for sputter excitation. At Ga(+)-ion-beam currents of about 6 nA a spot size on the target of 1 microm is possible. The detection sensitivity in this operation mode is on the order of microprobe instrument highlight its capacity as a surface analytical tool. PMID:15048491

  4. High-resolution nuclear microprobe elemental mapping of teeth enamel-dentine interface exposed to acidic conditions

    NASA Astrophysics Data System (ADS)

    Pineda-Vargas, C. A.; Eisa, M. E.; Chikte, U. M. E.; Conradie, J. L.

    2004-10-01

    The process of demineralisation in tooth erosion due to exposure to acidic media was investigated in a group of test and control healthy human molar teeth. Analysis by micro-PIXE and proton-backscattering showed that the levels of trace elements were enriched and/or depleted according to experimental treatment. The atomic ratios of major constituents in the matrix were characteristic of test or controls with typical ratios: O 5P 1Ca 3F 1 for tests and O 6P 0.5Ca 3F 0.5 for controls. The correlation between maps of Ca and Zn in and around the interface between dentine and enamel in control samples showed two kinds of correlation strengths (for enamel and dentine). The strongest correlation was related to the enamel area.

  5. Pb-207/Pb-206 ages of individual mineral phases in Luna 20 material by ion microprobe mass analysis.

    NASA Technical Reports Server (NTRS)

    Andersen, C. A.; Hinthorne, J. R.

    1973-01-01

    Ion microprobe analyses of returned lunar material have helped to demonstrate that U, Th, and radiogenic Pb are concentrated in small accessory mineral phases. It is possible to measure the isotopic composition of this Pb and obtain a radiometric Pb-207/Pb-206 age for the mineral. The ages so derived compare favorably with crystallization ages determined by conventional methods. A grain mount (22003,2/6) of Luna 20 material was searched for such accessory mineral phases, and two were found. One of these phases give an age of 4.12 plus or minus 0.04 b.y. and the other an age of 4.42 plus or minus 0.11 b.y. Ages of minerals dated by the ion probe in Apollo samples 14310 and 15555 are given for comparison. Data on the upper limit for Pb concentration in the outermost surface layers of free lunar soil particles are also given.

  6. San Francisco Estuary Striped Bass Migration History Determined by Electron-microprobe Analysis of Otolith Sr/Ca Ratio

    SciTech Connect

    Ostrach, D J; Phillis, C C; Weber, P K; Ingram, B L; Zinkl, J G

    2004-09-17

    Habitat use has been shown to be an important factor in the bioaccumulation of contaminants in striped bass. This study examines migration in striped bass as part of a larger study investigating bioaccumulation and maternal transfer of xenobiotics to progeny in the San Francisco Estuary system. Habitat use, residence time and spawning migration over the life of females (n = 23) was studied. Female striped bass were collected between Knights Landing and Colusa on the Sacramento River during the spawning runs of 1999 and 2001. Otoliths were removed, processed and aged via otolith microstructure. Subsequently, otoliths were analyzed for strontium/calcium (Sr/Ca) ratio using an electron-microprobe to measure salinity exposure and to distinguish freshwater, estuary, and marine habitat use. Salinity exposure during the last year before capture was examined more closely for comparison of habitat use by the maternal parent to contaminant burden transferred to progeny. Results were selectively confirmed by ion microprobe analyses for habitat use. The Sr/Ca data demonstrate a wide range of migratory patterns. Age of initial ocean entry differs among individuals before returning to freshwater, presumably to spawn. Some fish reside in freshwater year-round, while others return to more saline habitats and make periodic migrations to freshwater. Frequency of habitat shifts and residence times differs among fish, as well as over the lifetime of individual fish. While at least one fish spent its final year in freshwater, the majority of spawning fish spent their final year in elevated salinity. However, not all fish migrated to freshwater to spawn in the previous year. Results from this investigation concerning migration history in striped bass can be combined with contaminant and histological developmental analyses to better understand the bioaccumulation of contaminants and the subsequent effects they and habitat use have on fish populations in the San Francisco Estuary system.

  7. Calcification of basal ganglia and cerebellar roof nuclei in mentally defective patient with hidrotic ectodermal dysplasia. Analysis of intracranial concretions by electon microprobe.

    PubMed

    Copeland, D D; Lamb, W A; Klintworth, G K

    1977-11-01

    This report describes, for the first time, an analysis by electron microprobe of concretions in the brain of an individual with striopallidodentate calcification. We also report the unique association of this intracranial syndrome with hidrotic ectodermal dysplasia. An institutionalized male with impaired intellectual function and hidrotic ectodermal dysplasia was known since the age of 3 years to have bilateral radiopaque densities in the region of the basal ganglia on skull roentgenogram. He died at age 29 in congestive heart failure from rheumatic pancarditis. At autopsy, concretions were identified in globus pallidus, caudate nuclei, thalamus, and dentate nuclei. Mineral deposits within the brain, analyzed by energy dispersive x-ray microanalysis, consisted predominately of calcium and phosphorus. Trace amounts of magnesium, iron, and silicon also were detected. PMID:562997

  8. HYPER-FORM—A Hypercard® program for Macintosh® microcomputers to calculate mineral formulae from electron microprobe and wet chemical analysis

    NASA Astrophysics Data System (ADS)

    de Bjerg, Silvia C.; Mogessie, Aberra; Bjerg, Ernesto

    1992-07-01

    The program HYPER-FORM permits the input and calculation of a mineral formula from wet chemical and electron microprobe analysis. It includes autosaving of data, search routines, and other database functions. The calculated formula can be exported to wordprocessing programs such as MacWrite® or Microsoft Word® and can be edited as required. It also is possible to export the calculated data to graphic programs such as Cricket Graph® or Kaleidagraph® for a graphic representation of the data. HYPER-FORM is an interactive program written in HyperTalk™ (HyperCard® environment) and is designed to correspond to the Macintosh® interface.

  9. FUN with PANURGE - High mass resolution ion microprobe measurements of Mg in Allende inclusions. [meteoritic composition isotope analysis

    NASA Technical Reports Server (NTRS)

    Huneke, J. C.; Armstrong, J. T.; Wassserburg, G. J.

    1983-01-01

    Isotopic ratios have been determined, at a precision level approaching that of counting statistics using beam switching, by employing PANURGE, a modified CAMECA IMS3F ion microprobe at a mass resolving power of 5000. This technique is used to determine the isotopic composition of Mg and Si and the atomic ratio of Al/Mg in minerals from the Allende inclusion WA and the Allende FUN inclusion C1. Results show enrichment in Mg-26 of up to 260 percent. Results of Mg and Al/Mg measurements on cogenetic spinel inclusion and host plagiclase crystals show Mg-Al isochrons in excellent agreement with precise mineral isochrons determined by thermal emission mass spectrometry. The measurements are found to confirm the presence of substantial excess Mg-26 in WA and its near absence in C1. Data is obtained which indicates a metamorphic reequilibrium of Mg in Allende plagioclase at least 0.6 my after WA formation. Ion probe measurements are obtained which confirm that the Mg composition in Allende C1 is highly fractionated and is uniform among pyroxene, melilite, plagioclase, spinel crystals, and spinel included in melilite and plagioclase crystals.

  10. Nuclear microprobe analysis of solar proton implantation profiles in lunar rock surfaces

    NASA Technical Reports Server (NTRS)

    Stauber, M. C.; Padawer, G. M.; D'Agostino, M. D.; Kamykowski, E.; Brandt, W.; Young, D. A.

    1973-01-01

    Discussion of the results of hydrogen (proton) depth profile concentration analyses conducted on selected Apollo 16 rocks. A modeling of solar particle implantation profiles in lunar rocks is shown to trace the evolvement of these profiles under the combined influence of diffusion of atomic particles implanted in the rock, and rock surface erosion. It is also demonstrated that such diffusion may have a significant effect on the shape of the implantation profiles in certain rock materials.

  11. Light detection with spectral analysis at the Legnaro nuclear microprobe: Applications in material and earth sciences

    NASA Astrophysics Data System (ADS)

    Vittone, E.; Lo Giudice, A.; Manfredotti, C.; Egeni, G.; Rudello, V.; Rossi, P.; Gennaro, G.; Pratesi, G.; Corazza, M.

    2001-07-01

    Among the numerous ion beam analytical (IBA) techniques available for material characterisation, ionoluminescence (IL) has not attracted the interest that it should deserve. Although the importance of IL technique, particularly if combined with other IBA techniques, has been widely proven, very few apparatuses to analyse light emission spectra have been installed at the microbeam facilities. In this paper we present the new IL apparatus installed at the Legnaro (LNL) Ion Microbeam Facility. The system is a modification of the OXFORD MONOCL2 apparatus for cathodoluminescence. Light collection is performed by using a retractable parabolic mirror located at a very short distance from the sample, with a small aperture to allow the ion beam to hit the sample. Accurate positioning of the retractable mirror directly coupled to a chamber mounted high-resolution monochromator allows for high light collection efficiency. This design assures that IL can be used with low beam currents (<1 pA) with the consequent reduction of the radiation damage, which often occurs during ionoluminescence measurements. A summary of some meaningful results obtained with such an apparatus is presented. The combination of IL/PIXE was used to characterise natural silica glass, known as Libyan Desert Glass, and cubic BN grains; polycristalline CVD diamond has been studied by a synergetic combination of IBICC/IL technique.

  12. Nuclear and radiochemical analysis

    SciTech Connect

    Ehmann, W.D.; Yates, S.W.

    1988-06-15

    In this, their second fundamental review under the present authorship and title, they have chosen to continue their emphasis on topics representing the use of nuclear properties for chemical analysis. Excluded are topics in the areas of health physics, nuclear spectroscopy (unless directly related to analysis), nuclear engineering, fusion, radioactive waste disposal, fallout, and nuclear and particle physics. Other topics such as particle-induced X-ray emission (PIXE), plasma desorption mass spectrometry, radioimmunoassay, Moessbauer spectroscopy, nuclear dating methods, and radiotracer applications are treated briefly here, since they are adequately covered in other current reviews in this or other major journals. Only a brief mention is made of well logging, since many of the advances in this field do not currently appear in the open literature. As in their previous review, they finish with short comments on some interesting developments in nuclear and radiochemistry that are not strictly analytical in nature. This review is based largely on a computerized keyword search of Chemical Abstracts (CA) for the period from mid-November 1985 through December 31, 1987.

  13. Nuclear and radiochemical analysis

    SciTech Connect

    Ehmann, W.D.; Robertson, J.D.; Yates, S.W.

    1992-06-15

    This is the fourth in a series of periodic reviews on the subject of nuclear and radiochemical analysis. The review covers material found in books and journals concerning radiochemical, neutron activation, charged-particle activation, ion beam, isotope dilution, direct counting, transmission, attenuation, scattering, tracer, and isotopic dating methods.

  14. Positron microprobe at LLNL

    SciTech Connect

    Asoka, P; Howell, R; Stoeffl, W

    1998-11-01

    The electron linac based positron source at Lawrence Livermore National Laboratory (LLNL) provides the world's highest current beam of keV positrons. We are building a positron microprobe that will produce a pulsed, focused positron beam for 3-dimensional scans of defect size and concentration with sub-micron resolution. The widely spaced and intense positron packets from the tungsten moderator at the end of the 100 MeV LLNL linac are captured and trapped in a magnetic bottle. The positrons are then released in 1 ns bunches at a 20 MHz repetition rate. With a three-stage re-moderation we will compress the cm-sized original beam to a 1 micro-meter diameter final spot on the target. The buncher will compress the arrival time of positrons on the target to less than 100 ps. A detector array with up to 60 BaF2 crystals in paired coincidence will measure the annihilation radiation with high efficiency and low background. The energy of the positrons can be varied from less than 1 keV up to 50 keV.

  15. Ion Microprobe U-Pb Dating and REE Analysis of Apatite from Kerogen-rich Silica Dike from North Pole Area, Pilbara Craton, Western Australia

    NASA Astrophysics Data System (ADS)

    Nishizawa, M.

    2003-12-01

    In order to provide a time constraint on the 13C-depleted kerogen in silica dikes that intruded 3.5 Ga greenstone from Pilbara Craton in Western Australia, we have carried out an ion microprobe U-Pb dating and rare earth element (REE) analysis of apatite from the dike. Two types of apatite were identified in the dikes based on their occurrences. One is stick-shape apatites (Type 1) in secondary silica micro-veins that cut the silica dike. The other is granular apatites (Type 2) that occurs in matrix of the dike. Occurrence in the secondary micro-veins (Type 1), non-igenous chondrite normalized REE patterns (Type 1 and 2), chemical zoning (some of Type 1 and 2), and presence of mineral inclusion that is composed of Fe and S (some of Type 2) suggest that both Type 1 and 2 apatites were crystallized in the silica dike. Ion microprobe U-Pb dating of Type 1 apatite did not give a meaningful age, while Type 2 apatite yields a Tera-Wasserburg concordia intercept age of 3214 +/- 140 Ma (95 per cent confidence level, MSWD = 0.6) in a three-dimensional 238U/206Pb-207Pb/206Pb-204Pb/206Pb diagram, and a 204Pb/206Pb-207Pb/206Pb isochron age of 3191 +/- 150 Ma (95 per cent confidence level, MSWD = 0.5). It is difficult to judge whether the U-Pb and Pb-Pb age of Type 2 apatite is crystallization age or metamorphic age, since the estimated range of closure temperature of U-Pb system in the apatite and that of metamorphic temperature is partly overlapped. In either case, it can be safely concluded that the minimum age of the dike and kerogen is 3.0 Ga. These ages might allow the interpretation that the kerogen was produced by biological carbon fixation and/or abiological reaction (such as Fischer-Tropsch Type reaction) at least before 3.0 Ga.

  16. In-situ determination of metallic variation and multi-association in single particles by combining synchrotron microprobe, sequential chemical extraction and multivariate statistical analysis.

    PubMed

    Zhu, Yu-Min; Zhang, Hua; Fan, Shi-Suo; Wang, Si-Jia; Xia, Yi; Shao, Li-Ming; He, Pin-Jing

    2014-07-15

    Due to the heterogeneity of metal distribution, it is challenging to identify the speciation, source and fate of metals in solid samples at micro scales. To overcome these challenges single particles of air pollution control residues were detected in situ by synchrotron microprobe after each step of chemical extraction and analyzed by multivariate statistical analysis. Results showed that Pb, Cu and Zn co-existed as acid soluble fractions during chemical extraction, regardless of their individual distribution as chlorides or oxides in the raw particles. Besides the forms of Fe2O3, MnO2 and FeCr2O4, Fe, Mn, Cr and Ni were closely associated with each other, mainly as reducible fractions. In addition, the two groups of metals had interrelations with the Si-containing insoluble matrix. The binding could not be directly detected by micro-X-ray diffraction (μ-XRD) and XRD, suggesting their partial existence as amorphous forms or in the solid solution. The combined method on single particles can effectively determine metallic multi-associations and various extraction behaviors that could not be identified by XRD, μ-XRD or X-ray absorption spectroscopy. The results are useful for further source identification and migration tracing of heavy metals. PMID:24887126

  17. Hard X-Ray Spectro Microprobe Analysis of Inhomogeneous Solids: A Case Study. Element Distribution and Speciation in Selected Iron Meteorite

    SciTech Connect

    Cavell, R.G.; Feng, R.; Barnes, E.M.; Cavell, P.A.; McCready, A.J.; Webb, M.A.

    2007-06-08

    The hard X-ray microprobe provides an effective methodology for the non-destructive analysis of inhomogeneous materials. Application of X-ray absorption/fluroescence spectroscopy techniques (XANES and EXAFS) permits the speciation of the elements and yields information about the local structural environment. Microfocussed, monochromatic, tunable X-rays allows examination of small areas of micrometer dimensions with spectroscopic procedures. Typically the materials which are presented are thick and cannot be altered for the experiment. This condition introduces difficulties which may compromise the results. Herein we discuss those difficulties and show that the system can yield reliable results in spite of the compromises. Some results are presented on the two iron meteorites we have examined. These specimens are representative of highly inhomogeneous materials and illustrate the difficulties encountered with compositional variations which may occur at sub-millimeter dimensions and also illustrate the difficulties presented by the need to analyze components present at ppm concentration levels in a concentrated matrix. In these particular samples the major constituent is Fe which ranges from 90% to 70%, balanced by Ni which ranges from 10% to 30%. The critical diagnostic trace elements Ga and Ge which must also be analyzed are present at the 80 and 340 ppm level respectively. These diagnostic elements have been shown by EXAFS to be substitutionally placed in the matrix of the major element species in these meteorite samples.

  18. The Stanford-U.S. Geological Survey SHRIMP ion microprobe--a tool for micro-scale chemical and isotopic analysis

    USGS Publications Warehouse

    Bacon, Charles R.; Grove, Marty; Vazquez, Jorge A.; Coble, Matthew A.

    2012-01-01

    Answers to many questions in Earth science require chemical analysis of minute volumes of minerals, volcanic glass, or biological materials. Secondary Ion Mass Spectrometry (SIMS) is an extremely sensitive analytical method in which a 5–30 micrometer diameter "primary" beam of charged particles (ions) is focused on a region of a solid specimen to sputter secondary ions from 1–5 nanograms of the sample under high vacuum. The elemental abundances and isotopic ratios of these secondary ions are determined with a mass spectrometer. These results can be used for geochronology to determine the age of a region within a crystal thousands to billions of years old or to precisely measure trace abundances of chemical elements at concentrations as low as parts per billion. A partnership of the U.S. Geological Survey and the Stanford University School of Earth Sciences operates a large SIMS instrument, the Sensitive High-Resolution Ion Microprobe with Reverse Geometry (SHRIMP–RG) on the Stanford campus.

  19. Retrieval analysis of different orthodontic brackets: the applicability of electron microprobe techniques for determining material heterogeneities and corrosive potential

    PubMed Central

    HOLST, Alexandra Ioana; HOLST, Stefan; HIRSCHFELDER, Ursula; von SECKENDORFF, Volker

    2012-01-01

    Objective The objective of this study was to investigate the applicability of micro-analytical methods with high spatial resolution to the characterization of the composition and corrosion behavior of two bracket systems. Material and methods The surfaces of six nickel-free brackets and six nickel-containing brackets were examined for signs of corrosion and qualitative surface analysis using an electron probe microanalyzer (EPMA), prior to bonding to patient's tooth surfaces and four months after clinical use. The surfaces were characterized qualitatively by secondary electron (SE) images and back scattered electron (BSE) images in both compositional and topographical mode. Qualitative and quantitative wavelength-dispersive analyses were performed for different elements, and by utilizing qualitative analysis the relative concentration of selected elements was mapped two-dimensionally. The absolute concentration of the elements was determined in specially prepared brackets by quantitative analysis using pure element standards for calibration and calculating correction-factors (ZAF). Results Clear differences were observed between the different bracket types. The nickel-containing stainless steel brackets consist of two separate pieces joined by a brazing alloy. Compositional analysis revealed two different alloy compositions, and reaction zones on both sides of the brazing alloy. The nickel-free bracket was a single piece with only slight variation in element concentration, but had a significantly rougher surface. After clinical use, no corrosive phenomena were detectable with the methods applied. Traces of intraoral wear at the contact areas between the bracket slot and the arch wire were verified. Conclusion Electron probe microanalysis is a valuable tool for the characterization of element distribution and quantitative analysis for corrosion studies. PMID:23032212

  20. U-Th-Pb ion microprobe analysis of monazite from the Paleoproterozoic Karrat rare earth element (REE) deposit, western Greenland

    NASA Astrophysics Data System (ADS)

    Mott, A.; Grove, M.; Bird, D. K.

    2012-12-01

    The Karrat rare earth element (REE) deposit is located at 72°N on the Niaqornakavsak peninsula of Qeqertarssuq Island on the western coast of Greenland. Metasomatic alteration of an amphibolite host rock by carbonatite derived fluids resulted in REE mineralization in the Karrat Isfjord area. REE in the mineralization are primarily found in bastnasite, allanite, and monazite. In-situ analysis of monazite was conducted on samples obtained from three sites of mineralization: (1) the primary deposit at Niaqornakavsak consisting of a single distinct ~30m thick unit; (2) at Umiamako Nuna 7 km to the east of Niaqornakavsak where the majority of REE mineralization occurs within the first 20m of the surface; and (3) a 6m thick REE-rich vein 100m below the surface at Umiamako Nuna. Formation ages for monazite at Niaqornakavsak, Umiamako Nuna (surface), and Umiamako Nuna (vein) have been calculated using 207Pb/206Pb, 206Pb/238U, and 208Pb/232Th isotope ratios. Multiple isotope ratios were examined to determine the ideal method of monazite analysis based on the inherent issues of low U content of monazite, difficulties measuring 204Pb, common Pb corrections, and peak interferences resulting from high concentrations of REE. 208Pb/232Th analysis resulted in the best precision and smallest spread of values. Energy filtering was applied to 208Pb/232Th analyses in an effort to reduce interferences at several peaks. Although all three isotope ratio analyses result in a Paleoproterozoic age similar to the timing of convergence of the North Atlantic craton, Rae craton, and Aasiat domain as well as the emplacement of the Prøven Igneous Complex in Greenland (1.95-1.80Ga), the values range between 1.7-1.9Ga depending on the isotope ratio.

  1. X-ray microprobe analysis of the retina and RPE in sheep with ovine ceroid-lipofuscinosis

    SciTech Connect

    Samuelson, D.A.; Armstrong, D.; Jolly, R. )

    1990-11-01

    Ovine ceroid-lipofuscinosis (OCL) is one animal model for the human condition, and because autofluorescent lipopigments are prominent in the brain and eye, it may also prove useful as a model for aging. For example, a progressive decline in electrical recording from brain and retina are observed in both aging and OCL. Samples of retinal and retinal pigment epithelial (RPE) tissues were obtained from a young control. 2 animals with OCL and a normal aged sheep. Specimens were cryo-fractured and examined by scanning electron microscopy/x-ray microanalysis. Measurements made of 6 individual cells in the ganglion layer of OCL specimens, the remainder of the retina, and RPE showed age-related changes in zinc, iron, and copper which were associated with lipopigment accumulation in the RPE. There was marked decrease in phosphate, sulfur, and manganese levels, as photoreceptor cells and their outer segments are lost in the disease process. This is the first report of metal analysis in the retina and RPE in a disease entity, and as a function of normal aging.

  2. Microprobe analysis, iono- and photo-luminescence of Mn2+ activated ZnGa2O4 fibres

    NASA Astrophysics Data System (ADS)

    Santos, N. F.; Fernandes, A. J. S.; Alves, L. C.; Sobolev, N. A.; Alves, E.; Lorenz, K.; Costa, F. M.; Monteiro, T.

    2013-07-01

    Cubic ZnGa2O4 fibres have been grown by the laser floating zone technique with different pulling rates. In fibres activated with manganese ions, the room temperature photo- and iono-luminescence is dominated by an intense green emission which is observed by the naked eye. The green band is due to an overlap of the 4T1 → 6A1 intraionic transitions of the Mn2+ ions in different sites in the gallate host. The fibres' photoluminescence spectra have been found to be dependent on the excitation energy. Additionally, the intensity of the green photo- and iono-luminescence is strongly sensitive to the measurement temperature and proton irradiation time. Micro PIXE analysis was used in order to verify the homogeneous distribution of the Mn luminescence activators and determine its concentration as well as for verification of impurity contents that may have been incorporated during the fibres growth. The potential of ionoluminescence measurements for characterization of optical materials is discussed.

  3. The Review of Nuclear Microscopy Techniques: An Approach for Nondestructive Trace Elemental Analysis and Mapping of Biological Materials

    PubMed Central

    Mulware, Stephen Juma

    2015-01-01

    The properties of many biological materials often depend on the spatial distribution and concentration of the trace elements present in a matrix. Scientists have over the years tried various techniques including classical physical and chemical analyzing techniques each with relative level of accuracy. However, with the development of spatially sensitive submicron beams, the nuclear microprobe techniques using focused proton beams for the elemental analysis of biological materials have yielded significant success. In this paper, the basic principles of the commonly used microprobe techniques of STIM, RBS, and PIXE for trace elemental analysis are discussed. The details for sample preparation, the detection, and data collection and analysis are discussed. Finally, an application of the techniques to analysis of corn roots for elemental distribution and concentration is presented. PMID:26664356

  4. The Review of Nuclear Microscopy Techniques: An Approach for Nondestructive Trace Elemental Analysis and Mapping of Biological Materials.

    PubMed

    Mulware, Stephen Juma

    2015-01-01

    The properties of many biological materials often depend on the spatial distribution and concentration of the trace elements present in a matrix. Scientists have over the years tried various techniques including classical physical and chemical analyzing techniques each with relative level of accuracy. However, with the development of spatially sensitive submicron beams, the nuclear microprobe techniques using focused proton beams for the elemental analysis of biological materials have yielded significant success. In this paper, the basic principles of the commonly used microprobe techniques of STIM, RBS, and PIXE for trace elemental analysis are discussed. The details for sample preparation, the detection, and data collection and analysis are discussed. Finally, an application of the techniques to analysis of corn roots for elemental distribution and concentration is presented. PMID:26664356

  5. Skeletal muscle fiber analysis by atmospheric pressure scanning microprobe matrix-assisted laser desorption/ionization mass spectrometric imaging at high mass and high spatial resolution.

    PubMed

    Tsai, Yu-Hsuan; Bhandari, Dhaka Ram; Garrett, Timothy J; Carter, Christy S; Spengler, Bernhard; Yost, Richard A

    2016-06-01

    Skeletal muscles are composed of heterogeneous muscle fibers with various fiber types. These fibers can be classified into different classes based on their different characteristics. MALDI mass spectrometric imaging (MSI) has been applied to study and visualize different metabolomics profiles of different fiber types. Here, skeletal muscles were analyzed by atmospheric pressure scanning microprobe MALDI-MSI at high spatial and high mass resolution. PMID:27198224

  6. Nuclear Reactor Engineering Analysis Laboratory

    SciTech Connect

    Carlos Chavez-Mercado; Jaime B. Morales-Sandoval; Benjamin E. Zayas-Perez

    1998-12-31

    The Nuclear Reactor Engineering Analysis Laboratory (NREAL) is a sophisticated computer system with state-of-the-art analytical tools and technology for analysis of light water reactors. Multiple application software tools can be activated to carry out different analyses and studies such as nuclear fuel reload evaluation, safety operation margin measurement, transient and severe accident analysis, nuclear reactor instability, operator training, normal and emergency procedures optimization, and human factors engineering studies. An advanced graphic interface, driven through touch-sensitive screens, provides the means to interact with specialized software and nuclear codes. The interface allows the visualization and control of all observable variables in a nuclear power plant (NPP), as well as a selected set of nonobservable or not directly controllable variables from conventional control panels.

  7. The electron microprobe as a metallographic tool

    NASA Technical Reports Server (NTRS)

    Goldstein, J. I.

    1974-01-01

    The electron microprobe (EMP) is shown to represent one of the most powerful techniques for the examination of the microstructure of materials. It is an electron optical instrument in which compositional and topographic information is obtained from regions smaller than 1 micron in diameter on a specimen. Photographs of compositional and topographic changes in 1-sq-mm to 20-sq-micron areas on various types of specimens can also be obtained. These photographs are strikingly similar to optical photomicrographs. Various signals measured in the EMP (X-rays, secondary electrons, backscattered electrons, etc.) are discussed, along with their resolution and the type of information they may help obtain. In addition to elemental analysis, solid state detecting and scanning techniques are reviewed. Various techniques extending the EMP instrument capabilities, such as deconvolution and soft X-ray analysis, are also described.

  8. Development and applications of an epifluorescence module for synchrotron x-ray fluorescence microprobe imaging

    SciTech Connect

    Miller, Lisa M.; Smith, Randy J.; Ruppel, Meghan E.; Ott, Cassandra H.; Lanzirotti, Antonio

    2005-06-15

    Synchrotron x-ray fluorescence (XRF) microprobe is a valuable analysis tool for imaging trace element composition in situ at a resolution of a few microns. Frequently, epifluorescence microscopy is beneficial for identifying the region of interest. To date, combining epifluorescence microscopy with x-ray microprobe has involved analyses with two different microscopes. We report the development of an epifluorescence module that is integrated into a synchrotron XRF microprobe beamline, such that visible fluorescence from a sample can be viewed while collecting x-ray microprobe images simultaneously. This unique combination has been used to identify metal accumulation in Alzheimer's disease plaques and the mineral distribution in geological samples. The flexibility of this accessory permits its use on almost any synchrotron x-ray fluorescence microprobe beamline and applications in many fields of science can benefit from this technology.

  9. Nuclear microprobe determination of platinum quantitative distribution in rat brain tumors after cisplatin or carboplatin injection for PAT treatment of glioma

    NASA Astrophysics Data System (ADS)

    Ortega, R.; Biston, M.-C.; Devès, G.; Bohic, S.; Carmona, A.

    2005-04-01

    Conventional radiotherapy of high-grade glioma is unsuccessful since less than 50% of patients survive at 6 months, therefore glioma treatment is still challenging. A new radiotherapy procedure has been recently proposed, the photoactivation therapy (PAT), associating synchrotron radiation with a chemotherapy agent, such as cisplatin. PAT aims at using the monochromaticity and the very high brilliance of the synchrotron radiation for selective excitation of a high-Z compound introduced in tumor cell DNA to maximize the photoelectric effect probability, thus increasing local toxicity. Synchrotron irradiation of cisplatin at the platinum absorption K-edge resulted in a dramatic increase in life span relative to median survival time in the F98 glioma model in Fisher rat. In the purpose to optimize the platinum concentration into the tumor, the platinum content of irradiated target needs to be quantified. These results will enable to correlate injected dose to cellular platinum content in the tumor at the time of irradiation, and to study the spatial diffusion and distribution of the platinum into the tumor and the surrounding healthy tissues from the point of injection. Male Fisher 344 rats were inoculated with 103 F98 glioma cells. Thirteen days after stereotactic inoculation, intracerebral injection at the tumor site of 40 μg of carboplatin and 3 or 5 μg of cisplatin was performed. Platinum quantitative distribution in tumors and adjacent brain tissues was determined using μ-PIXE and μ-RBS analysis.

  10. NMR spectroscopy and perfusion of mammalian cells using surface microprobes.

    PubMed

    Ehrmann, Klaus; Pataky, Kristopher; Stettler, Matthieu; Wurm, Florian Maria; Brugger, Jürgen; Besse, Pierre-André; Popovic, Radivoje

    2007-03-01

    NMR spectra of mammalian cells are taken using surface microprobes that are based on microfabricated planar coils. The surface microprobe resembles a miniaturized Petri dish commonly used in biological research. The diameter of the planar coils is 1 mm. Chinese Hamster Ovaries are immobilized in a uniform layer on the microprobe surface or patterned by an ink-jet printer in the centre of the microcoil, where the rf-field of the planar microcoil is most uniform. The acquired NMR spectra show the prevalent metabolites found in mammalian cells. The volumes of the detected samples range from 25 nL to 1 nL (or 50,000 to 1800 cells). With an extended set-up that provides fluid inlets and outlets to the microprobe, the cells can be perfused within the NMR-magnet while constantly taking NMR spectra. Perfusion of the cells opens the way to increased cell viability for long acquisitions or to analysis of the cells' response to environmental change. PMID:17330170

  11. Dynamic Analysis of Nuclear Energy System Strategies

    SciTech Connect

    Den Durpel, Luc Van

    2004-06-17

    DANESS is an integrated process model for nuclear energy systems allowing the simulation of multiple reactors and fuel cycles in a continuously changing nuclear reactor park configuration. The model is energy demand driven and simulates all nuclear fuel cycle facilites, up to 10 reactors and fuels. Reactor and fuel cycle facility history are traced and the cost of generating energy is calculated per reactor and for total nuclear energy system. The DANESS model aims at performing dynamic systems analysis of nuclear energy development used for integrated analysis of development paths for nuclear energy, parameter scoping for new nuclear energy systems, economic analysis of nuclear energy, government role analysis, and education.

  12. Dating Archean zircon by ion microprobe: New light on an old problem

    NASA Technical Reports Server (NTRS)

    Williams, I. S.; Kinny, P. D.; Black, L. P.; Compston, W.; Froude, D. O.; Ireland, T. R.

    1985-01-01

    Ion microprobe analysis of zircons from three sites (Watersmeet Dome in northern Michigan, Mount Sones in eastern Antarctica, and Mount Narryer in western Australia) is discussed. Implications of the results to Archean geochronology and early Earth crust composition are addressed.

  13. Microprobe analyses of glasses and minerals from Luna-16 soil

    NASA Technical Reports Server (NTRS)

    Brown, R. W.; Harmon, R. S.; Jakes, P.; Reid, A. M.; Ridley, W. I.; Warner, J. L.

    1971-01-01

    Electron microprobe analyses are presented for nine elements in 250 glasses and 434 pyroxenes, eight elements in 113 olivines, and six elements in 354 feldspars, 35 spinels, and 159 ilmenites. All grains are from the 125-425 micron fraction of horizon A and horizon D soil from the Luna 16 sample. A norm is presented for each glass analysis and the structural formula is calculated for each mineral analysis.

  14. U, Th, Pb and REE abundances and Pb 207/Pb 206 ages of individual minerals in returned lunar material by ion microprobe mass analysis.

    NASA Technical Reports Server (NTRS)

    Andersen, C. A.; Hinthorne, J. R.

    1972-01-01

    Results of ion microprobe analyses of Apollo 11, 12 and 14 material, showing that U, Th, Pb and REE are concentrated in accessory minerals such as apatite, whitlockite, zircon, baddeleyite, zirkelite, and tranquillityite. Th/U ratios are found to vary by over a factor of 40 in these minerals. K, Ba, Rb and Sr have been localized in a K rich, U and Th poor glass phase that is commonly associated with the U and Th bearing accessory minerals. Li is observed to be fairly evenly distributed between the various accessory phases. The phosphates have been found to have REE abundance patterns (normalized to the chondrite abundances) that are fairly flat, while the Zr bearing minerals have patterns that rise steeply, by factors of ten or more, from La to Gd. All the accessory minerals have large negative Eu anomalies. Radiometric age dates (Pb 207/Pb 206) of the individual U and Th bearing minerals compare favorably with the Pb 207/Pb 206 age of the bulk rocks.

  15. Proton enhanced scattering and nuclear reaction analysis microcharacterization of ternary graphite-lithium-calcium intercalation compounds

    NASA Astrophysics Data System (ADS)

    Berger, P.; Pruvost, S.; Hérold, C.; Lagrange, P.

    2004-06-01

    Intercalation of lithium into graphite is of great interest, due to its largely expanded use as negative electrode material in the Li-ion batteries, especially the LiC 6 compound. Recently, the first ternary intercalation compounds associating lithium with a second metallic element were synthesized by immersing pyrographite platelet in a molten Ca-Li alloy. Photonic and neutronic diffractions on these graphite-lithium-calcium compounds reveal that lithium and calcium layers are intercalated between graphene sheets. However, the precise elemental composition still lacks. Chemical analysis gives an average composition but carbon is not measured in the same sample as calcium and lithium. Electron microprobe, SEM and TEM do not allow to determine lithium concentration and its distribution in these compounds. This paper reports the first elemental characterization of carbon-calcium-lithium intercalation compounds by means of nuclear microprobe. Using a 3.1 MeV proton beam, both lithium, calcium and carbon can be determined within a single measurement, from the 7Li(p,α) 4He nuclear reaction and from elastic scattering for calcium and carbon respectively. In the graphite-lithium-calcium system, three different intercalation compounds were synthesized, containing low to high lithium content. The mapping of the samples reveals lateral and also mainly in depth heterogeneity (along the c axis).

  16. Radioactive halos and ion microprobe measurement of Pb isotope ratios

    NASA Technical Reports Server (NTRS)

    Gentry, R. V.

    1974-01-01

    This investigation was to obtain, if possible, the Pb isotope ratios of both lunar and meteoritic troilite grains by utilizing ion microprobe techniques. Such direct in situ measurement of Pb isotope ratios would eliminate contamination problems inherent in wet chemistry separation procedures, and conceivably determine whether lunar troilite grains were of meteoritic origin. For comparison purposes two samples of meteoritic troilite were selected (one from Canyon Diablo) for analysis along with two very small lunar troilite grains (approximately 50-100 microns). It was concluded that the ion microprobe as presently operating, does not permit the in situ measurement of Pb isotope ratios in lunar or meteoritic troilite. On the basis of these experiments no conclusions could be drawn as to the origin of the lunar troilite grains.

  17. Production of a positron microprobe using a transmission remoderator.

    PubMed

    Fujinami, Masanori; Jinno, Satoshi; Fukuzumi, Masafumi; Kawaguchi, Takumi; Oguma, Koichi; Akahane, Takashi

    2008-01-01

    A production method for a positron microprobe using a beta+-decay radioisotope (22Na) source has been investigated. When a magnetically guided positron beam was extracted from the magnetic field, the combination of an extraction coil and a magnetic lens enabled us to focus the positron beam by a factor of 10 and to achieve a high transport efficiency (71%). A 150-nm-thick Ni(100) thin film was mounted at the focal point of the magnetic lens and was used as a remoderator for brightness enhancement in a transmission geometry. The remoderated positrons were accelerated by an electrostatic lens and focused on the target by an objective magnetic lens. As a result, a 4-mm-diameter positron beam could be transformed into a microprobe of 60 microm or less with 4.2% total efficiency. The S parameter profile obtained by a single-line scan of a test specimen coincided well with the defect distribution. This technique for a positron microprobe is available to an accelerator-based high-intensity positron source and allows 3-dimensional vacancy-type defect analysis and a positron source for a transmission positron microscope. PMID:18187852

  18. Nuclear Proliferation Technology Trends Analysis

    SciTech Connect

    Zentner, Michael D.; Coles, Garill A.; Talbert, Robert J.

    2005-10-04

    A process is underway to develop mature, integrated methodologies to address nonproliferation issues. A variety of methodologies (both qualitative and quantitative) are being considered. All have one thing in common, a need for a consistent set of proliferation related data that can be used as a basis for application. One approach to providing a basis for predicting and evaluating future proliferation events is to understand past proliferation events, that is, the different paths that have actually been taken to acquire or attempt to acquire special nuclear material. In order to provide this information, this report describing previous material acquisition activities (obtained from open source material) has been prepared. This report describes how, based on an evaluation of historical trends in nuclear technology development, conclusions can be reached concerning: (1) The length of time it takes to acquire a technology; (2) The length of time it takes for production of special nuclear material to begin; and (3) The type of approaches taken for acquiring the technology. In addition to examining time constants, the report is intended to provide information that could be used to support the use of the different non-proliferation analysis methodologies. Accordingly, each section includes: (1) Technology description; (2) Technology origin; (3) Basic theory; (4) Important components/materials; (5) Technology development; (6) Technological difficulties involved in use; (7) Changes/improvements in technology; (8) Countries that have used/attempted to use the technology; (9) Technology Information; (10) Acquisition approaches; (11) Time constants for technology development; and (12) Required Concurrent Technologies.

  19. Correlated petrographic, electron microprobe, and ion microprobe studies of selected primitive and processed phase assemblages in meteorites

    NASA Technical Reports Server (NTRS)

    Albee, Arden L.

    1993-01-01

    During the past three years we have received support to continue our research in elucidating the formation and alteration histories of selected meteoritic materials by a combination of petrographic, trace element, and isotopic analyses employing optical and scanning electron microscopes and electron and ion microprobes. The awarded research funds enabled the P.I. to attend the annual LPSC, the co-I to devote approximately 15 percent of his time to the research proposed in the grant, and partial support for a visiting summer post-doctoral fellow to conduct electron microprobe analyses of meteoritic samples in our laboratory. The research funds, along with support from the NASA Education Initiative awarded to P.I. G. Wasserburg, enabled the co-I to continue a mentoring program with inner-city minority youth. The support enabled us to achieve significant results in the five projects that we proposed (in addition to the Education Initiative), namely: studies of the accretional and post-accretional alteration and thermal histories in CV meteorites, characterization of periclase-bearing Fremdlinge in CV meteorites, characterization of Ni-Pt-Ge-Te-rich Fremdlinge in CV meteorites in an attempt to determine the constraints they place on the petrogenetic and thermal histories of their host CAI's, correlated electron and ion microprobe studies of silicate and phosphate inclusions in the Colomera meteorite in an attempt to determine the petrogenesis of the IE iron meteorites, and development of improved instrumental and correction procedures for improved accuracy of analysis of meteoritic materials with the electron microprobe. This grant supported, in part or whole, 18 publications so far by our research team, with at least three more papers anticipated. The list of these publications is included. The details of the research results are briefly summarized.

  20. Dynamic Analysis of Nuclear Energy System Strategies

    Energy Science and Technology Software Center (ESTSC)

    2004-06-17

    DANESS is an integrated process model for nuclear energy systems allowing the simulation of multiple reactors and fuel cycles in a continuously changing nuclear reactor park configuration. The model is energy demand driven and simulates all nuclear fuel cycle facilites, up to 10 reactors and fuels. Reactor and fuel cycle facility history are traced and the cost of generating energy is calculated per reactor and for total nuclear energy system. The DANESS model aims atmore » performing dynamic systems analysis of nuclear energy development used for integrated analysis of development paths for nuclear energy, parameter scoping for new nuclear energy systems, economic analysis of nuclear energy, government role analysis, and education.« less

  1. Nuclear Power Plant Module, NPP-1: Nuclear Power Cost Analysis.

    ERIC Educational Resources Information Center

    Whitelaw, Robert L.

    The purpose of the Nuclear Power Plant Modules, NPP-1, is to determine the total cost of electricity from a nuclear power plant in terms of all the components contributing to cost. The plan of analysis is in five parts: (1) general formulation of the cost equation; (2) capital cost and fixed charges thereon; (3) operational cost for labor,…

  2. Microprobe sampling--photo ionization-time-of-flight mass spectrometry for in situ chemical analysis of pyrolysis and combustion gases: examination of the thermo-chemical processes within a burning cigarette.

    PubMed

    Hertz, Romy; Streibel, Thorsten; Liu, Chuan; McAdam, Kevin; Zimmermann, Ralf

    2012-02-10

    A microprobe sampling device (μ-probe) has been developed for in situ on-line photo ionization mass spectrometric analysis of volatile chemical species formed within objects consisting of organic matter during thermal processing. With this approach the chemical signature occurring during heating, pyrolysis, combustion, roasting and charring of organic material within burning objects such as burning fuel particles (e.g., biomass or coal pieces), lit cigarettes or thermally processed food products (e.g., roasting of coffee beans) can be investigated. Due to its dynamic changes between combustion and pyrolysis phases the cigarette smoking process is particularly interesting and has been chosen as first application. For this investigation the tip of the μ-probe is inserted directly into the tobacco rod and volatile organic compounds from inside the burning cigarette are extracted and real-time analyzed as the glowing front (or coal) approaches and passes the μ-probe sampling position. The combination of micro-sampling with photo ionization time-of-flight mass spectrometry (PI-TOFMS) allows on-line intrapuff-resolved analysis of species formation inside a burning cigarette. Monitoring volatile smoke compounds during cigarette puffing and smoldering cycles in this way provides unparalleled insights into formation mechanisms and their time-dependent change. Using this technique the changes from pyrolysis conditions to combustion conditions inside the coal of a cigarette could be observed directly. A comparative analysis of species formation within a burning Kentucky 2R4F reference cigarette with μ-probe analysis reveals different patterns and behaviors for nicotine, and a range of semi-volatile aromatic and aliphatic species. PMID:22244143

  3. The composition of hypersaline, iron-rich granitic fluids based on laser-ICP and Synchrotron-XRF microprobe analysis of individual fluid inclusions in topaz, Mole granite, eastern Australia

    NASA Astrophysics Data System (ADS)

    Rankin, A. H.; Ramsey, M. H.; Coles, B.; Van Langevelde, F.; Thomas, C. R.

    1992-01-01

    High-temperature (>550°C) hypersaline (>50 wt% salts) fluid inclusions, representative of the earliest hydrothermal fluids associated with the Sn-W-Cu-Pb-Zn-mineralised Mole granite of eastern Australia, are well developed in topaz from the Fielders Hill locality. Methods based on Inductively Coupled Plasma Emission Spectroscopy following laser ablation and on Synchrotron X-Ray Fluorescence microanalysis are described and applied to the semiquantitative point analysis of these inclusions. Crushleach analysis provides further information as well as highlighting the importance of point methods when several generations of inclusions are present. The laser-ICP results confirm the dominance of Fe, K, and Na in these early high-temperature fluids. The mean Fe:K:Na atomic ratios (0.95:0.79:1.00) are entirely in agreement with published experimental data on the composition of chloride brines in equilibrium with synthetic granite at magmatic temperatures and support the view that these fluids are direct products from a cooling granite magma. A number of trace and minor elements have also been detected in the inclusions. These include Ca, Mg, Li, B, Be, Ba, Sr, and several of the ore metals. Order of magnitude estimates of the ore metal contents of these fluids, based on combined XRF-microprobe and laser-ICP analysis, are in the percent range for Fe, Mn, and Zn, in the range from several hundred to several thousand ppm in the case of Sn, Cu, and Pb, and less than 600 ppm for Mo and W. These results have important implications for ore genesis in granitic environments and point to the very high ore-carrying potential of high-temperature, hypersaline, chloride-rich brines exsolved from cooling granite magmas.

  4. Nuclear weapon detection categorization analysis

    SciTech Connect

    1997-12-01

    This statement of work is for the Proof of Concept for nuclear weapon categories utility in Arms control. The focus of the project will be to collect, analyze and correlate Intrinsic Radiation (INRAD) calculation results for the purpose of defining measurable signatures that differentiate categories of nuclear weapons. The project will support START III negotiations by identifying categories of nuclear weapons. The categories could be used to clarify sub-limits on the total number of nuclear weapons.

  5. On the distribution of uranium in hair: Non-destructive analysis using synchrotron radiation induced X-ray fluorescence microprobe techniques

    NASA Astrophysics Data System (ADS)

    Israelsson, A.; Eriksson, M.; Pettersson, H. B. L.

    2015-06-01

    In the present study the distribution of uranium in single human hair shafts has been evaluated using two synchrotron radiation (SR) based micro X-ray fluorescence techniques; SR μ-XRF and confocal SR μ-XRF. The hair shafts originated from persons that have been exposed to elevated uranium concentrations. Two different groups have been studied, i) workers at a nuclear fuel fabrication factory, exposed mainly by inhalation and ii) owners of drilled bedrock wells exposed by ingestion of water. The measurements were carried out on the FLUO beamline at the synchrotron radiation facility ANKA, Karlsruhe. The experiment was optimized to detect U with a beam size of 6.8 μm × 3 μm beam focus allowing detection down to ppb levels of U in 10 s (SR μ-XRF setup) and 70 s (SR confocal μ-XRF setup) measurements. It was found that the uranium was present in a 10-15 μm peripheral layer of the hair shafts for both groups studied. Furthermore, potential external hair contamination was studied by scanning of unwashed hair shafts from the workers. Sites of very high uranium signal were identified as particles containing uranium. Such particles, were also seen in complementary analyses using variable pressure electron microscope coupled with energy dispersive X-ray analyzer (ESEM-EDX). However, the particles were not visible in washed hair shafts. These findings can further increase the understanding of uranium excretion in hair and its potential use as a biomonitor.

  6. FTIR Analysis of Aerogel Keystones from the Stardust Interstellar Dust Collector: Assessment of Terrestrial Organic Contamination and X-Ray Microprobe Beam Damage

    NASA Technical Reports Server (NTRS)

    Zolensky, M. E.; Bechtel, H. A.; Allen, C.; Bajt, S.; Borg, J.; Brenker, F.; Bridges, J.; Brownlee, D. E.; Burchell, M.; Burghammer, M.; Butterworth, A. L.; Cloetens, P.; Davis, A. M.; Floss, C.; Flynn, G. J.; Frank, D.; Gainsforth, Z.; Grun, E.; Hech, P R.; Hillier, J. K.

    2011-01-01

    The Stardust Interstellar Dust Collector (SIDC) was intended to capture and return contemporary interstellar dust. The approx.0.1 sq m collector was composed of aerogel tiles (85% of the collecting area) and aluminum foils and was exposed to the interstellar dust stream for a total exposure factor of 20 sq m day. The Stardust Interstellar Preliminary Examination (ISPE) is a consortium-based project to characterize the collection using nondestructive techniques. Sandford et al. recently assessed numerous potential sources of organic contaminants in the Stardust cometary collector. These contaminants could greatly complicate the analysis and interperetation of any organics associated with interstellar dust, particularly because signals from these particles are expected to be exceedingly small. Here, we present a summary of FTIR analyses of over 20 aerogel keystones, many of which contained candidates for interstellar dust.

  7. The second Mars microprobe is unloaded

    NASA Technical Reports Server (NTRS)

    1998-01-01

    In the Spacecraft Assembly and Encapsulation Facility -2 (SAEF- 2), Chris Voorhees (left) and Satish Krishnan (right), from the Jet Propulsion Laboratory, remove the second Mars microprobe from a drum. Two microprobes will hitchhike on the Mars Polar Lander, scheduled to be launched Jan. 3, 1999, aboard a Delta II rocket. The solar-powered spacecraft is designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere. The Mars microprobes, called Deep Space 2, are part of NASA's New Millennium Program. They will complement the climate-related scientific focus of the lander by demonstrating an advanced, rugged microlaser system for detecting subsurface water. Such data on polar subsurface water, in the form of ice, should help put limits on scientific projections for the global abundance of water on Mars.

  8. Geochemistry of the Spor Mountain rhyolite, western Utah, as revealed by laser ablation ICP-MS, cathodoluminescence, and electron microprobe analysis

    NASA Astrophysics Data System (ADS)

    Dailey, S. R.; Christiansen, E. H.; Dorais, M.; Fernandez, D. P.

    2015-12-01

    The Miocene topaz rhyolite at Spor Mountain in western Utah hosts one of the largest beryllium deposits in the world and was responsible for producing 85% of the beryllium mined worldwide in 2010 (Boland, 2012). The Spor Mountain rhyolite is composed primarily of Ca-poor plagioclase (An8), sodic sanidine (Or40), Fe-rich biotite (Fe/(Fe+Mg)>0.95; Al 1.2-1.4 apfu), and Ti-poor quartz, along with several trace-element rich accessory phases including zircon, monazite, thorite, columbite, and allanite. Cathodoluminescence (CL) studies of quartz show oscillatory zoning, with 80% of the examined crystals displaying euhedral edges and slightly darker rims. CL images were used to guide laser ablation (LA) ICP-MS analysis of quartz, along with analyses of plagioclase, sanidine, biotite, and glass. Ti concentrations in quartz are 20±6 ppm; there is no quantifiable variation of Ti from core to rim within the diameter of the laser spot (53 microns). Temperatures, calculated using Ti in quartz (at 2 kb, aTiO2=0.34), vary between 529±10 C (Thomas et al., 2011), 669±13 C (Huang and Audetat, 2012), and 691±13 C (Wark and Watson, 2006). Two feldspar thermometry yield temperatures of 686±33 C (Elkins and Grove, 1990) and 670±41 C (Benisek et al., 2010). Zr saturation temperatures (Watson and Harrison, 1983) average 711±28 C. Analysis of the glass reveal the Spor Mountain rhyolite is greatly enriched in rare elements (i.e. Li, Be, F, Ga, Rb, Nb, Mo, Sn, and Ta) compared to average continental crust (Rudnick and Gao, 2003). Be in the glass can have as much as 100 ppm, nearly 50 times the concentration in continental crust. REE partition coefficients for sanidine are 2 to 3 times higher in the Spor Mountain rhyolite when compared to other silicic magmas (Nash and Crecraft, 1985; Mahood and Hildreth, 1983), although plagioclase tends to have lower partition coefficients; biotite has lower partition coefficients for LREE and higher partition coefficients for HREE. The patterns of

  9. Tin accumulation in spermatozoa of the rats exposed to tributyltin chloride by synchrotron radiation X-ray fluorescence (SR-XRF) analysis with microprobe

    NASA Astrophysics Data System (ADS)

    Homma-Takeda, S.; Nishimura, Y.; Terada, Y.; Ueno, S.; Watanabe, Y.; Yukawa, M.

    2005-04-01

    Organotin compounds are widely used in industry and its environmental contamination by these compounds has recently become a concern. It is known that they act as endocrine disruptors but details of the dynamics of Sn in reproductive organs are still unknown. In the present study, we attempted to determine Sn distribution in the testis of rats exposed to tributyltin chloride (TBTC) by inductively coupled argon plasma-mass spectrometry (ICP-MS) for microdissectioned seminiferous tubules and cell-selective metal determination of synchrotron radiation X-ray florescence (SR-XRF) analysis. TBTC was orally administered to rats at a dose of 45 μmol/kg per day for 3 days. One day later, Sn was detected in the microdissectioned seminiferous tubules at a level approximately equivalent to that in the testis. Significant stage-specificity of Sn accumulation was not observed in the experimental model. Sn was also detected in spermatozoa at the stage VIII seminiferous tubule, which are the final step of spermatogenesis in the testis. These data indicate that Sn accumulates in germ cells as well as in spermatozoa in a short period of TBTC exposure.

  10. Application of a new Raman microprobe spectrometer to nondestructive analysis of sulfate and other ions in individual phases in fluid inclusions in minerals

    USGS Publications Warehouse

    Rosasco, G.J.; Roedder, E.

    1979-01-01

    Rosasco et al. (1975), reported the first successful application of laser-excited Raman spectroscopy for the identification and nondestructive partial analysis of individual solid, liquid, and gaseous phases in selected fluid inclusions. We report here the results of the application of a new instrument, based on back-scattering, that eliminates many of the previous stringent sample limitations and hence greatly expands the range of applicability of Raman spectroscopy to fluid inclusions. Fluid inclusions in many porphyry copper deposits contain 5-10 ??m 'daughter' crystals thought to be anhydrite but too small for identification by the previous Raman technique. Using the new instrument, we have verified that such daughter crystals in quartz from Bingham, Utah, are anhydrite. They may form by leakage of hydrogen causing internal autooxidation of sulfide ion. Daughter crystals were also examined in apatite (Durango, Mexico) and emerald (Muzo, Colombia). Valid analyses of sulfur species in solution in small fluid inclusions from ore deposits would be valuable, but are generally impossible by conventional methods. We present a calibration procedure for analyses for SO42- in such inclusions from Bingham, Utah (12,000 ?? 4000 ppm) and Creede, Colo. (probably < 500 ppm). A fetid Brazilian quartz, originally thought to contain liquid H2S, is shown to contain only HS- in major amounts. ?? 1979.

  11. In vivo analysis of tissue by Raman microprobe: examination of human skin lesions and esophagus Barrett's mucosa on an animal model

    NASA Astrophysics Data System (ADS)

    Tfayli, Ali; Piot, Olivier; Derancourt, Sylvie; Cadiot, Guillaume; Diebold, Marie D.; Bernard, Philippe; Manfait, Michel

    2006-02-01

    In the last few years, Raman spectroscopy has been increasingly used for the characterization of normal and pathological tissues. A new Raman system, constituted of optic fibers bundle coupled to an axial Raman spectrometer (Horiba Jobin Yvon SAS), was developed for in vivo investigations. Here, we present in vivo analysis on two tissues: human skin and esophagus mucosa on a rat model. The skin is a directly accessible organ, representing a high diversity of lesions and cancers. Including malignant melanoma, basal cell carcinoma and the squamous cell carcinoma, skin cancer is the cancer with the highest incidence worldwide. Several Raman investigations were performed to discriminate and classify different types of skin lesions, on thin sections of biopsies. Here, we try to characterize in vivo the different types of skin cancers in order to be able to detect them in their early stages of development and to define precisely the exeresis limits. Barrett's mucosa was also studied by in vivo examination of rat's esophagus. Barrett's mucosa, induced by gastro-esophageal reflux, is a pretumoral state that has to be carefully monitored due to its high risk of evolution in adenocarcinoma. A better knowledge of the histological transformation of esophagus epithelium in a Barrett's type will lead to a more efficient detection of the pathology for its early diagnosis. To study these changes, an animal model (rats developing Barrett's mucosa after duodenum - esophagus anastomosis) was used. Potential of vibrational spectroscopy for Barrett's mucosa identification is assessed on this model.

  12. Nuclear microscopy in biomedical analysis with special emphasis on clinical metal biology

    NASA Astrophysics Data System (ADS)

    Lindh, Ulf; Frisk, Peter; Nyström, Joakim; Danersund, Antero; Hudecek, Romuald; Lindvall, Anders; Thunell, Stig

    1997-07-01

    Nuclear microscopy based upon developments in high energy ion beam techniques is by now an accepted technique in many fields of research. The advancements into the biomedical field have, however, been slower than expected. A major factor explaining this tendency is the availability of nuclear microscopy. This paper reviews briefly the biomedical work using nuclear microscopy that has been carried out since the 4 th International Conference on Nuclear Microprobe Technology and Applications held in Shanghai. Nuclear microscopy of isolated individual blood cells from patients adversely affected by metal exposure from dental amalgam has been performed both before and after removal of the metallic fillings. The elemental profile of blood cells was more or less normalised after treatment. Some of these results will be presented to illustrate a medical application. Results from bulk analysis by ICP-MS of erythrocytes and plasma before and after treatment will also be presented to illustrate the difference in information content between these two approaches as well as the need for complementary information in solving biomedical problems. As part of a larger study of acute porphyria, nuclear microscopy of blood cells was included among the 78 laboratory tests. The approach in this study was unbiased in the sense that no hypothesis was formulated as to which laboratory parameters would be the most explanatory for health or disease. Multivariate discriminant analysis was applied to the large amounts of data acquired. This approach led to the hypothesis that oxidative stress increased the synthesis of manganese-dependent superoxide dismutase in the mitochondria of polymorphonuclear leukocytes, explaining the increase of manganese in these cells. Antioxidant therapy was therefore applied to a couple of patients with porphyria, however, without clinical success.

  13. Microprobe investigation of brittle segregates in aluminum MIG and TIG welds

    NASA Technical Reports Server (NTRS)

    Larssen, P. A.; Miller, E. L.

    1968-01-01

    Quantitative microprobe analysis of segregated particles in aluminum MIG /Metal Inert Gas/ and TIG /Tungsten Inert Gas/ welds indicated that there were about ten different kinds of particles, corresponding to ten different intermetallic compounds. Differences between MIG and TIG welds related to the individual cooling rates of these welds.

  14. MicroProbe Small Unmanned Aerial System

    NASA Technical Reports Server (NTRS)

    Bland, Geoffrey; Miles, Ted

    2012-01-01

    The MicroProbe unmanned aerial system (UAS) concept incorporates twin electric motors mounted on the vehicle wing, thus enabling an aerodynamically and environmentally clean nose area for atmospheric sensors. A payload bay is also incorporated in the fuselage to accommodate remote sensing instruments. A key feature of this concept is lightweight construction combined with low flying speeds to minimize kinetic energy and associated hazards, as well as maximizing spatial resolution. This type of aerial platform is needed for Earth science research and environmental monitoring. There were no vehicles of this type known to exist previously.

  15. Autoclave nuclear criticality safety analysis

    SciTech Connect

    D`Aquila, D.M.; Tayloe, R.W. Jr.

    1991-12-31

    Steam-heated autoclaves are used in gaseous diffusion uranium enrichment plants to heat large cylinders of UF{sub 6}. Nuclear criticality safety for these autoclaves is evaluated. To enhance criticality safety, systems are incorporated into the design of autoclaves to limit the amount of water present. These safety systems also increase the likelihood that any UF{sub 6} inadvertently released from a cylinder into an autoclave is not released to the environment. Up to 140 pounds of water can be held up in large autoclaves. This mass of water is sufficient to support a nuclear criticality when optimally combined with 125 pounds of UF{sub 6} enriched to 5 percent U{sup 235}. However, water in autoclaves is widely dispersed as condensed droplets and vapor, and is extremely unlikely to form a critical configuration with released UF{sub 6}.

  16. The first Mars microprobe is unloaded

    NASA Technical Reports Server (NTRS)

    1998-01-01

    In the Spacecraft Assembly and Encapsulation Facility -2 (SAEF- 2), workers from the Jet Propulsion Laboratory open the drums containing the Mars microprobes that will hitchhike on the Mars Polar Lander. From left, they are Satish Krishnan, Charles Cruzan, Chris Voorhees and Arden Acord. Scheduled to be launched Jan. 3, 1999, aboard a Delta II rocket, the solar-powered spacecraft is designed to touch down on the Martian surface near the northern-most boundary of the south pole in order to study the water cycle there. The lander also will help scientists learn more about climate change and current resources on Mars, studying such things as frost, dust, water vapor and condensates in the Martian atmosphere. The Mars microprobes, called Deep Space 2, are part of NASA's New Millennium Program. They will complement the climate-related scientific focus of the lander by demonstrating an advanced, rugged microlaser system for detecting subsurface water. Such data on polar subsurface water, in the form of ice, should help put limits on scientific projections for the global abundance of water on Mars.

  17. Multiattribute risk analysis in nuclear emergency management.

    PubMed

    Hämäläinen, R P; Lindstedt, M R; Sinkko, K

    2000-08-01

    Radiation protection authorities have seen a potential for applying multiattribute risk analysis in nuclear emergency management and planning to deal with conflicting objectives, different parties involved, and uncertainties. This type of approach is expected to help in the following areas: to ensure that all relevant attributes are considered in decision making; to enhance communication between the concerned parties, including the public; and to provide a method for explicitly including risk analysis in the process. A multiattribute utility theory analysis was used to select a strategy for protecting the population after a simulated nuclear accident. The value-focused approach and the use of a neutral facilitator were identified as being useful. PMID:11051070

  18. Defense against nuclear weapons: a decision analysis

    SciTech Connect

    Orient, J.M.

    1985-02-01

    Response to the public health threat posed by nuclear weapons is a medical imperative. The United States, in contrast to other nations, has chosen a course that assures maximal casualties in the event of a nuclear attack, on the theory that prevention of the attack is incompatible with preventive measures against its consequences, such as blast injuries and radiation sickness. A decision analysis approach clarifies the risks and benefits of a change to a strategy of preparedness.

  19. Design and characterization of a resonant triaxial microprobe

    NASA Astrophysics Data System (ADS)

    Goj, Boris; Dressler, Lothar; Hoffmann, Martin

    2015-12-01

    A new trend for tactile microprobes leads to oscillating microprobes in order to overcome the drawbacks resulting from high Hertzian stress and disturbing surface forces. Thin water films on the measurement surface result in the so-called sticking effect which causes measurement faults such as snap-back and false triggering. This leads to measurement errors and low measurement speeds. We present an innovative oscillating triaxial microprobe which safely avoids sticking in all Cartesian measurement directions. The system design as well as the characterization of the microprobe are presented in this work. The low number of coupling elements, the batch-capable design and the low contact forces are the key features of the microprobe.

  20. First direct-write lithography results on the Guelph high resolution proton microprobe

    NASA Astrophysics Data System (ADS)

    Wang, L. P.; de Kerckhove, D.

    2011-10-01

    The recently completed high-resolution proton microprobe at the University of Guelph is Canada's first one-micron nuclear microprobe, which represents the country's state-of-the-art technology for various nuclear microprobe applications, e.g. direct-write microlithography. Its probe-forming system is comprised of a triplet Oxford Micro beams magnetic quadrupole lenses, along with high-precision objective slits. High energy protons coming off a 3 MV particle accelerator can achieve a nominal resolution of one micro and a beam current of several hundred of picoamperes when arriving at the target. This proton probe is ideal for the use of direct-write lithography with the incorporation of a magnetic scanning system and motorized sample stage. Preliminary lithography results have been obtained using spin-coated PMMA photoresist as specimen. The beam spot size, beam range and straggling inside the substrate and the exposure conditions are investigated by using scanning electron microscopy. This facility is the first in Canada to perform focused direct-write ion beam lithography, which is ideal for modification and machining of polymer and semiconductor materials for biological, microfluidic and ultimate lab-on-chip applications.

  1. Microprobe PIXE study of Ni-Ge interactions in lateral diffusion couples

    NASA Astrophysics Data System (ADS)

    Chilukusha, D.; Pineda-Vargas, C. A.; Nemutudi, R.; Habanyama, A.; Comrie, C. M.

    2015-11-01

    Rutherford backscattering spectrometry on the nuclear microprobe (μRBS) is often used in studies of lateral diffusion couples. RBS requires that the positions of the interacting species on the periodic table are not too close in terms of atomic number and therefore do not produce excessive RBS peak overlap. In order to satisfactorily characterize systems that have atomic numbers which are close, it is necessary to find techniques which can complement μRBS. The aim of this study was to determine the extent to which particle induced X-ray emission (PIXE) could be applied in the lateral diffusion couple study of a system with relatively close atomic numbers. This was with a view that it may eventually be adopted to study systems where the atomic numbers are too close for RBS analysis. The system studied here was the Ni-Ge binary system. Since RBS is an established technique for studying lateral diffusion couples, we used it as a standard for comparison. The PIXE results showed a maximum error of 12% with reference to the RBS standard. In order to achieve the most effective use of PIXE in lateral diffusion couple studies we recommend the use of the technique in such a way as to obtain depth information and the use of relatively thick sample layers.

  2. Microprobe and oxygen fugacity study of armalcolite

    NASA Technical Reports Server (NTRS)

    Friel, J. J.

    1976-01-01

    The stability of synthetic armalcolite was determined as a function of oxygen fugacity with particular regard to the oxidation state of iron and titanium. The equilibrium pseudobrookite (armalcolite) composition was measured at 1200 C under various conditions of oxidation typical of the lunar environment. These data, when compared with published descriptions of mare basalts, provide information about the conditions of crystallization of armalcolite-bearing lunar rocks. Some information about the crystal chemistry of armalcolite was obtained from X-ray diffraction and electron microprobe analyses of synthetic armalcolite and Zr-armalcolite. Further data were gathered from a comparison of the Mossbauer spectra of a phase pure stoichiometric armalcolite and one containing appreciable amounts of trivalent titanium.

  3. Aerodynamics of the Mars Microprobe Entry Vehicles

    NASA Technical Reports Server (NTRS)

    Mitcheltree, R. A.; Moss, J. N.; Cheatwood, F. M.; Greene, F. A.; Braun, R. D.

    1997-01-01

    The selection of the unique aeroshell shape for the Mars Microprobes is discussed. A description of its aerodynamics in hypersonic rarefied, hypersonic continuum, supersonic and transonic flow regimes is then presented. This description is based on Direct Simulation Monte Carlo analyses in the rarefied-flow regime, thermochemical nonequilibrium Computational Fluid Dynamics in the hypersonic regime, existing wind tunnel data in the supersonic and transonic regime, additional computational work in the transonic regime, and finally, ballistic range data. The aeroshell is shown to possess the correct combination of aerodynamic stability and drag to convert the probe's initial tumbling attitude and high velocity at atmospheric-interface into the desired surface-impact orientation and velocity.

  4. Nuclear analysis of Jordanian tobacco

    NASA Astrophysics Data System (ADS)

    Al-Saleh, K. A.; Saleh, N. S.

    The concentration of trace and minor elements in six different Jordanian and two foreign brands of cigarette tobacco and wrapping paper were determined using combined X-ray fluorescence (XRF) and Rutherford backscatteing (RBS) analysis techniques. The cigarette filter and the ash were also analyzed to determine the trapped elements on the filter and their transference with smoke. The toxic effects of some elements have been briefly discussed.

  5. Analysis of nuclear power plant component failures

    SciTech Connect

    Not Available

    1984-01-01

    Items are shown that have caused 90% of the nuclear unit outages and/or deratings between 1971 and 1980 and the magnitude of the problem indicated by an estimate of power replacement cost when the units are out of service or derated. The funding EPRI has provided on these specific items for R and D and technology transfer in the past and the funding planned in the future (1982 to 1986) are shown. EPRI's R and D may help the utilities on only a small part of their nuclear unit outage problems. For example, refueling is the major cause for nuclear unit outages or deratings and the steam turbine is the second major cause for nuclear unit outages; however, these two items have been ranked fairly low on the EPRI priority list for R and D funding. Other items such as nuclear safety (NRC requirements), reactor general, reactor and safety valves and piping, and reactor fuel appear to be receiving more priority than is necessary as determined by analysis of nuclear unit outage causes.

  6. Molecular forensic science analysis of nuclear materials

    NASA Astrophysics Data System (ADS)

    Reilly, Dallas David

    Concerns over the proliferation and instances of nuclear material in the environment have increased interest in the expansion of nuclear forensics analysis and attribution programs. A new related field, molecular forensic science (MFS) has helped meet this expansion by applying common scientific analyses to nuclear forensics scenarios. In this work, MFS was applied to three scenarios related to nuclear forensics analysis. In the first, uranium dioxide was synthesized and aged at four sets of static environmental conditions and studied for changes in chemical speciation. The second highlighted the importance of bulk versus particle characterizations by analyzing a heterogeneous industrially prepared sample with similar techniques. In the third, mixed uranium/plutonium hot particles were collected from the McGuire Air Force Base BOMARC Site and analyzed for chemical speciation and elemental surface composition. This work has identified new signatures and has indicated unexpected chemical behavior under various conditions. These findings have lead to an expansion of basic actinide understanding, proof of MFS as a tool for nuclear forensic science, and new areas for expansion in these fields.

  7. Nuclear radiation analysis for TFTR

    SciTech Connect

    Ku, L.P.

    1980-09-01

    A multi-dimensional analysis of the radiation problems was performed for TFTR using the system established at PPPL. Simple, clean geometries were first used to establish the expected reference level. Different calculational models were compared. The characteristics of streaming and activation were then studied. It is shown that the objectives set forth for the TFTR shielding design are not entirely satisfied, based on our calculation. Using the results of this study as a baseline, a review of the shielding for TFTR and its upgrade, TFM, has been initiated with the objective of a shielding design modified to satisfy both modes of operation.

  8. Bimodal Nuclear Thermal Rocket Analysis Developments

    NASA Technical Reports Server (NTRS)

    Belair, Michael; Lavelle, Thomas; Saimento, Charles; Juhasz, Albert; Stewart, Mark

    2014-01-01

    Nuclear thermal propulsion has long been considered an enabling technology for human missions to Mars and beyond. One concept of operations for these missions utilizes the nuclear reactor to generate electrical power during coast phases, known as bimodal operation. This presentation focuses on the systems modeling and analysis efforts for a NERVA derived concept. The NERVA bimodal operation derives the thermal energy from the core tie tube elements. Recent analysis has shown potential temperature distributions in the tie tube elements that may limit the thermodynamic efficiency of the closed Brayton cycle used to generate electricity with the current design. The results of this analysis are discussed as well as the potential implications to a bimodal NERVA type reactor.

  9. Determination of trace element mineral/liquid partition coefficients in melilite and diopside by ion and electron microprobe techniques

    NASA Technical Reports Server (NTRS)

    Kuehner, S. M.; Laughlin, J. R.; Grossman, L.; Johnson, M. L.; Burnett, D. S.

    1989-01-01

    The applicability of ion microprobe (IMP) for quantitative analysis of minor elements (Sr, Y, Zr, La, Sm, and Yb) in the major phases present in natural Ca-, Al-rich inclusions (CAIs) was investigated by comparing IMP results with those of an electron microprobe (EMP). Results on three trace-element-doped glasses indicated that it is not possible to obtain precise quantitative analysis by using IMP if there are large differences in SiO2 content between the standards used to derive the ion yields and the unknowns.

  10. Application of the Karlsruhe proton microprobe to medical samples

    NASA Astrophysics Data System (ADS)

    Heck, D.; Rokita, E.

    1984-04-01

    The Karlsruhe nuclear microprobe was used in the investigation of healthy and malign tissue of animals and men. Target preparation tests showed that cryofixation of the tissue before cutting with a microtome and succeeding lyophilization of the slices gave reliable results. The slices were mounted on backing foils of Formvar the thickness of which varied between 30 and 50 {μg}/{cm 2}. For irradiation we tested various patterns generated by the 3 MeV proton beam by sweeping in one or two dimensions. Most of the data were collected in line-scan mode, where 256 equidistant irradiation dots of 3 × 10 μm 2 formed a line of 750 μm length at beam currents of 250 pA. The target thickness was determined simultaneously by proton elastic scattering in all cases. Radial concentration profiles of degenerated human arteries (atherosclerosis) showed a remarkable increase of Ca, partly correlated with local maxima of the Zn content, when compared with non-degenerated capillaries. Microtome cuts across a Morris Hepatoma 7777 cancer grown in a rat leg were investigated to correlate the concentration shifts of some trace elements in malign tissue with single cells.

  11. Multiphysics Nuclear Thermal Rocket Thrust Chamber Analysis

    NASA Technical Reports Server (NTRS)

    Wang, Ten-See

    2005-01-01

    The objective of this effort is t o develop an efficient and accurate thermo-fluid computational methodology to predict environments for hypothetical thrust chamber design and analysis. The current task scope is to perform multidimensional, multiphysics analysis of thrust performance and heat transfer analysis for a hypothetical solid-core, nuclear thermal engine including thrust chamber and nozzle. The multiphysics aspects of the model include: real fluid dynamics, chemical reactivity, turbulent flow, and conjugate heat transfer. The model will be designed to identify thermal, fluid, and hydrogen environments in all flow paths and materials. This model would then be used to perform non- nuclear reproduction of the flow element failures demonstrated in the Rover/NERVA testing, investigate performance of specific configurations and assess potential issues and enhancements. A two-pronged approach will be employed in this effort: a detailed analysis of a multi-channel, flow-element, and global modeling of the entire thrust chamber assembly with a porosity modeling technique. It is expected that the detailed analysis of a single flow element would provide detailed fluid, thermal, and hydrogen environments for stress analysis, while the global thrust chamber assembly analysis would promote understanding of the effects of hydrogen dissociation and heat transfer on thrust performance. These modeling activities will be validated as much as possible by testing performed by other related efforts.

  12. A noncontact thermal microprobe for local thermal conductivity measurement.

    PubMed

    Zhang, Yanliang; Castillo, Eduardo E; Mehta, Rutvik J; Ramanath, Ganpati; Borca-Tasciuc, Theodorian

    2011-02-01

    We demonstrate a noncontact thermal microprobe technique for measuring the thermal conductivity κ with ∼3 μm lateral spatial resolution by exploiting quasiballistic air conduction across a 10-100 nm air gap between a joule-heated microprobe and the sample. The thermal conductivity is extracted from the measured effective thermal resistance of the microprobe and the tip-sample thermal contact conductance and radius in the quasiballistic regime determined by calibration on reference samples using a heat transfer model. Our κ values are within 5%-10% of that measured by standard steady-state methods and theoretical predictions for nanostructured bulk and thin film assemblies of pnictogen chalcogenides. Noncontact thermal microprobing demonstrated here mitigates the strong dependence of tip-sample heat transfer on sample surface chemistry and topography inherent in contact methods, and allows the thermal characterization of a wide range of nanomaterials. PMID:21361625

  13. A noncontact thermal microprobe for local thermal conductivity measurement

    NASA Astrophysics Data System (ADS)

    Zhang, Yanliang; Castillo, Eduardo E.; Mehta, Rutvik J.; Ramanath, Ganpati; Borca-Tasciuc, Theodorian

    2011-02-01

    We demonstrate a noncontact thermal microprobe technique for measuring the thermal conductivity κ with ˜3 μm lateral spatial resolution by exploiting quasiballistic air conduction across a 10-100 nm air gap between a joule-heated microprobe and the sample. The thermal conductivity is extracted from the measured effective thermal resistance of the microprobe and the tip-sample thermal contact conductance and radius in the quasiballistic regime determined by calibration on reference samples using a heat transfer model. Our κ values are within 5%-10% of that measured by standard steady-state methods and theoretical predictions for nanostructured bulk and thin film assemblies of pnictogen chalcogenides. Noncontact thermal microprobing demonstrated here mitigates the strong dependence of tip-sample heat transfer on sample surface chemistry and topography inherent in contact methods, and allows the thermal characterization of a wide range of nanomaterials.

  14. Stand-alone microprobe at Livermore

    SciTech Connect

    Antolak, A J; Bench, G S; Brown, T A; Frantz, B R; Grant, P G; Morse, D H; Roberts, M L

    1998-10-02

    Lawrence Livermore National Laboratory (LLNL) and Sandia National Laboratories/California have jointly constructed a new stand-alone microprobe facility. Although the facility was built to develop a method to rapidly locate and determine elemental concentrations of micron scale particulates on various media using PIXE, the facility has found numerous applications in biology and materials science. The facility is located at LLNL and uses a General Ionex Corporation Model 358 duoplasmatron negative ion source, a National Electrostatics Corporation 5SDH-2 tandem accelerator, and an Oxford triplet lens. Features of the system include complete computer control of the beam transport using LabVIEWTM for Macintosh, computer controlled beam collimating and divergence limiting slits, automated sample positioning to micron resolution, and video optics for beam positioning and sample observation. Data collection is accomplished with the simultaneous use of as many as four EG&G Ortec IGLET-XTM X-Ray detectors, digital amplifiers made by X-Ray Instruments and Associates (XIA), and LabVIEWTM for Macintosh acquisition software.

  15. Aerothermal Heating Predictions for Mars Microprobe

    NASA Technical Reports Server (NTRS)

    Mitcheltree, R. A.; DiFulvio, M.; Horvath, T. J.; Braun, R. D.

    1998-01-01

    A combination of computational predictions and experimental measurements of the aerothermal heating expected on the two Mars Microprobes during their entry to Mars are presented. The maximum, non-ablating, heating rate at the vehicle's stagnation point (at alpha = 0 degrees) is predicted for an undershoot trajectory to be 194 Watts per square centimeters with associated stagnation point pressure of 0.064 atm. Maximum stagnation point pressure occurs later during the undershoot trajectory and is 0.094 atm. From computations at seven overshoot-trajectory points, the maximum heat load expected at the stagnation point is near 8800 Joules per square centimeter. Heat rates and heat loads on the vehicle's afterbody are much lower than the forebody. At zero degree angle-of-attack, heating over much of the hemi-spherical afterbody is predicted to be less than 2 percent of the stagnation point value. Good qualitative agreement is demonstrated for forebody and afterbody heating between CFD calculations at Mars entry conditions and experimental thermographic phosphor measurements from the Langley 20-Inch Mach 6 Air Tunnel. A novel approach which incorporates six degree-of-freedom trajectory simulations to perform a statistical estimate of the effect of angle-of-attack, and other off-nominal conditions, on heating is included.

  16. A High-Speed Detector System for X-ray Fluorescence Microprobes.

    SciTech Connect

    Siddons,P.D.; Dragone, A.; De Geronimo, g.; Kuczewski, A.; Kuczewski, J.; O

    2006-10-29

    We have developed a high-speed system for collecting x-ray fluorescence microprobe data, based on ASICs developed at BNL and high-speed processors developed by CSIRO. The system can collect fluorescence data in a continuous raster scan mode, and present elemental images in real time using Ryan's Dynamic Analysis algorithm. We will present results from a 32-element prototype array illustrating the concept. The final instrument will have 384 elements arranged in a square array around a central hole.

  17. Analysis of Nuclear Quantum Phase Transitions

    SciTech Connect

    Li, Z. P.; Meng, J.; Niksic, T.; Vretenar, D.; Lalazissis, G. A.; Ring, P.

    2009-08-26

    A microscopic analysis, based on nuclear energy density functionals, is presented for shape phase transitions in Nd isotopes. Low-lying excitation spectra and transition probabilities are calculated starting from a five-dimensional Hamiltonian, with parameters determined by constrained relativistic mean-field calculations for triaxial shapes. The results reproduce available data, and show that there is an abrupt change of structure at N = 90, that corresponds to a first-order quantum phase transition between spherical and axially deformed shapes.

  18. Information Services at the Nuclear Safety Analysis Center.

    ERIC Educational Resources Information Center

    Simard, Ronald

    This paper describes the operations of the Nuclear Safety Analysis Center. Established soon after an accident at the Three Mile Island nuclear power plant near Harrisburg, Pennsylvania, its efforts were initially directed towards a detailed analysis of the accident. Continuing functions include: (1) the analysis of generic nuclear safety issues,…

  19. NUCLEAR FORENSICS ANALYSIS CENTER FORENSIC ANALYSIS TO DATA INTERPRETATION

    SciTech Connect

    Nichols, T.

    2011-02-07

    The Nuclear Forensics Analysis Center (NFAC) is part of Savannah River National Laboratory (SRNL) and is one of only two USG National Laboratories accredited to perform nuclear forensic analyses to the requirements of ISO 17025. SRNL NFAC is capable of analyzing nuclear and radiological samples from bulk material to ultra-trace samples. NFAC provides analytical support to the FBI's Radiological Evidence Examination Facility (REEF), which is located within SRNL. REEF gives the FBI the capability to perform traditional forensics on material that is radiological and/or is contaminated. SRNL is engaged in research and development efforts to improve the USG technical nuclear forensics capabilities. Research includes improving predictive signatures and developing a database containing comparative samples.

  20. Ion microprobe measurement of strontium isotopes in calcium carbonate with application to salmon otoliths

    USGS Publications Warehouse

    Weber, P.K.; Bacon, C.R.; Hutcheon, I.D.; Ingram, B.L.; Wooden, J.L.

    2005-01-01

    The ion microprobe has the capability to generate high resolution, high precision isotopic measurements, but analysis of the isotopic composition of strontium, as measured by the 87Sr/ 86Sr ratio, has been hindered by isobaric interferences. Here we report the first high precision measurements of 87Sr/ 86Sr by ion microprobe in calcium carbonate samples with moderate Sr concentrations. We use the high mass resolving power (7000 to 9000 M.R.P.) of the SHRIMP-RG ion microprobe in combination with its high transmission to reduce the number of interfering species while maintaining sufficiently high count rates for precise isotopic measurements. The isobaric interferences are characterized by peak modeling and repeated analyses of standards. We demonstrate that by sample-standard bracketing, 87Sr/86Sr ratios can be measured in inorganic and biogenic carbonates with Sr concentrations between 400 and 1500 ppm with ???2??? external precision (2??) for a single analysis, and subpermil external precision with repeated analyses. Explicit correction for isobaric interferences (peak-stripping) is found to be less accurate and precise than sample-standard bracketing. Spatial resolution is ???25 ??m laterally and 2 ??m deep for a single analysis, consuming on the order of 2 ng of material. The method is tested on otoliths from salmon to demonstrate its accuracy and utility. In these growth-banded aragonitic structures, one-week temporal resolution can be achieved. The analytical method should be applicable to other calcium carbonate samples with similar Sr concentrations. Copyright ?? 2005 Elsevier Ltd.

  1. Distributed computing and nuclear reactor analysis

    SciTech Connect

    Brown, F.B.; Derstine, K.L.; Blomquist, R.N.

    1994-03-01

    Large-scale scientific and engineering calculations for nuclear reactor analysis can now be carried out effectively in a distributed computing environment, at costs far lower than for traditional mainframes. The distributed computing environment must include support for traditional system services, such as a queuing system for batch work, reliable filesystem backups, and parallel processing capabilities for large jobs. All ANL computer codes for reactor analysis have been adapted successfully to a distributed system based on workstations and X-terminals. Distributed parallel processing has been demonstrated to be effective for long-running Monte Carlo calculations.

  2. Nuclear fuel cycle facility accident analysis handbook

    SciTech Connect

    Ayer, J E; Clark, A T; Loysen, P; Ballinger, M Y; Mishima, J; Owczarski, P C; Gregory, W S; Nichols, B D

    1988-05-01

    The Accident Analysis Handbook (AAH) covers four generic facilities: fuel manufacturing, fuel reprocessing, waste storage/solidification, and spent fuel storage; and six accident types: fire, explosion, tornado, criticality, spill, and equipment failure. These are the accident types considered to make major contributions to the radiological risk from accidents in nuclear fuel cycle facility operations. The AAH will enable the user to calculate source term releases from accident scenarios manually or by computer. A major feature of the AAH is development of accident sample problems to provide input to source term analysis methods and transport computer codes. Sample problems and illustrative examples for different accident types are included in the AAH.

  3. Nuclear material production cycle vulnerability analysis

    SciTech Connect

    Bott, T.F.

    1996-07-01

    This paper discusses a method for rapidly and systematically identifying vulnerable equipment in a nuclear material or similar production process and ranking that equipment according to its attractiveness to a malevolent attacker. A multistep approach was used in the analysis. First, the entire production cycle was modeled as a flow diagram. This flow diagram was analyzed using graph theoretical methods to identify processes in the production cycle and their locations. Models of processes that were judged to be particularly vulnerable based on the cycle analysis then were developed in greater detail to identify equipment in that process that is vulnerable to intentional damage.

  4. Nickel geochemistry of a Philippine laterite examined by bulk and microprobe synchrotron analyses

    NASA Astrophysics Data System (ADS)

    Fan, Rong; Gerson, Andrea R.

    2011-11-01

    The Ni geochemistry of limonite and saprolite laterite ores from Pujada in the Philippines has been investigated using a mixture of laboratory and synchrotron techniques. Nickel laterite profiles are typically composed of complicated mineral assemblages, with Ni being distributed heterogeneously at the micron scale, and thus a high degree of spatial resolution is required for analysis. This study represents the first such analysis of Philippine laterite ores. Synchrotron bulk and microprobe X-ray absorption spectroscopy (XAS), comprising both X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopies, together with synchrotron microprobe X-ray fluorescence microscopy (XFM) and diffraction (XRD) have been applied to provide quantitative analysis of the mineral components and Ni speciation. Synchrotron microprobe EXAFS spectroscopy suggests that the limonite Ni is associated with phyllomanganate via adsorption onto the Mn oxide layers and substitution for Mn within these layers. Laboratory scanning electron microscopy, coupled to electron dispersive spectroscopy analyses, indicates that Ni is also associated with concentrated Fe containing particles and this is further confirmed by synchrotron bulk and microprobe investigation. Linear combination fitting of the bulk EXAFS limonite data suggests 60 ± 15% of the Ni is associated with phyllomanganate, with the predominant fraction adsorbed above vacancies in the MnO 6 layers with the remainder being substituted for Mn within these layers. The remaining 40 ± 10% of the Ni in the limonite ore is incorporated into goethite through replacement of the Fe. In the saprolite ore, 90 ± 23% of the Ni is associated with a serpentine mineral, most likely lizardite, as a replacement for Mg. The remaining Ni is found within phyllomanganate adsorbed above vacancies in the MnO 6 layers.

  5. The Bioscience Nuclear Microscopy Program at LLNL

    SciTech Connect

    Bench, G.; Freeman, S.; Roberts, M.; Sideras-Haddad, E.

    1996-12-31

    Since initiation in mid 1994, a bioscience nuclear microscopy program at Livermore has enabled collaboration with bio-scientists on a variety of projects requiring quantitative elemental microanalysis. For microprobe analysis a combination of PIXE and STIM are typically used; respectively generating element distribution maps with micron scale spatial resolution, and projected densities and histological information with sub-micron spatial resolution. Current studies demonstrate the applicability of nuclear microscopy (particularly when combined with other analysis techniques) in environmental tracing, toxicology, carcinogenesis, and structural biology. The program currently uses {approximately}10 percent of the available time on a 10 MV tandem accelerator that is also applied to a variety of Accelerator Mass Spectrometry and other microprobe programs. The completion of a dedicated nuclear microprobe system, using a 5 SDH NEC 1.7 MV tandem accelerator and employing several energy dispersive x-ray detectors to improve x-ray counting rates, promises increased accelerator access, greater sample throughput and continued expansion of the program.

  6. Biological Effects in Coral Biomineralization: The Ion-Microprobe Revolution

    NASA Astrophysics Data System (ADS)

    Meibom, A.

    2004-12-01

    Scleractinian corals are among the most prolific biomineralizing organisms on Earth and massive, reef-building corals are used extensively as proxies for past variations in the global climate. It is therefore of wide interest to understand the degree to which biological versus inorganic processes control the chemistry of the coral skeleton. Early workers considered aragonitic coral skeleton formation to be a purely physiochemical process. More recent studies have increasingly emphasized the role of a skeletal organic matrix, or intercalated organic macro-molecules that control the macroscopic shape and size of the growing crystals. It is now well established that organic compounds play a key role in controlling the morphology of crystals in a wide variety of calcium carbonate biomineralization processes by binding to specific sites, thereby causing direction-specific binding energies on the crystal surfaces. Macro-molecules, such as aspartic acid-rich or glutamic proteins and sulfated polysaccharides, are known to be embedded within the aragonitic skeletal components of coral. In addition, endosymbiotic algae and the layer of cells adjacent to the mineralizing surface, the calicoblastic ectoderm, are believed to play important roles in driving and controlling hermatypic coral skeletogenesis. However, until recently, further progress has been somewhat limited because it was not possible to obtain chemical analyses of the coral skeleton with sufficiently high spatial resolution and sensitivity to correlate chemical variations with the micrometer scale organization of its different structural components. The recent emergence of new ion microprobe technology is changing this situation radically. Conventional ion microprobe and laser ablation techniques have already contributed substantially to our knowledge about the micro-distribution of key trace elements such as B, Mg, Sr, Ba and U. However, with the development of the NanoSIMS, a newly designed ion microprobe

  7. Brain activity mapping at multiple scales with silicon microprobes containing 1,024 electrodes

    PubMed Central

    Shobe, Justin L.; Claar, Leslie D.; Parhami, Sepideh; Bakhurin, Konstantin I.

    2015-01-01

    The coordinated activity of neural ensembles across multiple interconnected regions has been challenging to study in the mammalian brain with cellular resolution using conventional recording tools. For instance, neural systems regulating learned behaviors often encompass multiple distinct structures that span the brain. To address this challenge we developed a three-dimensional (3D) silicon microprobe capable of simultaneously measuring extracellular spike and local field potential activity from 1,024 electrodes. The microprobe geometry can be precisely configured during assembly to target virtually any combination of four spatially distinct neuroanatomical planes. Here we report on the operation of such a device built for high-throughput monitoring of neural signals in the orbitofrontal cortex and several nuclei in the basal ganglia. We perform analysis on systems-level dynamics and correlations during periods of conditioned behavioral responding and rest, demonstrating the technology's ability to reveal functional organization at multiple scales in parallel in the mouse brain. PMID:26133801

  8. Laser Microprobe (U-Th)/He Thermochronology of Detrital Minerals

    NASA Astrophysics Data System (ADS)

    Hodges, K. V.; van Soest, M. C.

    2007-12-01

    A persistent concern in detrital mineral geochronology is the need to obtain a representative sampling of crystallization or cooling ages in the source region. Methods with high throughput --- e.g., laser microprobe 40Ar/39Ar thermochronology of muscovite and U-Pb thermochronology of zircon --- have a distinct advantage in this regard. Both techniques have advanced to the point that the dozens of analyses necessary to obtain a representative sampling can be done quickly and with sufficiently precision for high-quality research. Datasets obtained using methods that are far more labor intensive --- e.g., single-grain (U-Th)/He and fission track dating of minerals such as zircon --- typically include many fewer analyses. Consequently, we have less confidence that the cooling age distribution in the dataset represents the cooling age distribution in the source region. Of greater concern are analytical protocols that increase the probability of non-representative sampling. One example is the practice of picking zircon grains that are inclusion-free and euhedral (or nearly so) for conventional (U-Th)/He dating. While this practice is essential for successful conventional (U-Th)/He dating, it unavoidably leads to the systematic exclusion of grains that actually may represent significant portions of the source terrain. We describe a new approach to detrital mineral (U-Th)/He thermochronology that, in principle, provides a higher- fidelity record of the source region cooling history than the conventional technique. It involves the use of an excimer laser microprobe to ablate portions of the grain interiors from detrital zircons in a polished grain mount. (Prior to analyses, the grains can be mapped using backscattered electron and cathodoluminesence imagery.) The amounts of evolved 4He are typically so small that they are best measured using a magnetic-sector mass spectrometer rather than a quadrupole mass spectrometer of the type typically used for conventional (U- Th

  9. Single cell elemental analysis using nuclear microscopy

    NASA Astrophysics Data System (ADS)

    Ren, M. Q.; Thong, P. S. P.; Kara, U.; Watt, F.

    1999-04-01

    The use of Particle Induced X-ray Emission (PIXE), Rutherford Backscattering Spectrometry (RBS) and Scanning Transmission Ion Microscopy (STIM) to provide quantitative elemental analysis of single cells is an area which has high potential, particularly when the trace elements such as Ca, Fe, Zn and Cu can be monitored. We describe the methodology of sample preparation for two cell types, the procedures of cell imaging using STIM, and the quantitative elemental analysis of single cells using RBS and PIXE. Recent work on single cells at the Nuclear Microscopy Research Centre,National University of Singapore has centred around two research areas: (a) Apoptosis (programmed cell death), which has been recently implicated in a wide range of pathological conditions such as cancer, Parkinson's disease etc, and (b) Malaria (infection of red blood cells by the malaria parasite). Firstly we present results on the elemental analysis of human Chang liver cells (ATTCC CCL 13) where vanadium ions were used to trigger apoptosis, and demonstrate that nuclear microscopy has the capability of monitoring vanadium loading within individual cells. Secondly we present the results of elemental changes taking place in individual mouse red blood cells which have been infected with the malaria parasite and treated with the anti-malaria drug Qinghaosu (QHS).

  10. Adiabatic Hyperspherical Analysis of Realistic Nuclear Potentials

    NASA Astrophysics Data System (ADS)

    Daily, K. M.; Kievsky, Alejandro; Greene, Chris H.

    2015-12-01

    Using the hyperspherical adiabatic method with the realistic nuclear potentials Argonne V14, Argonne V18, and Argonne V18 with the Urbana IX three-body potential, we calculate the adiabatic potentials and the triton bound state energies. We find that a discrete variable representation with the slow variable discretization method along the hyperradial degree of freedom results in energies consistent with the literature. However, using a Laguerre basis results in missing energy, even when extrapolated to an infinite number of basis functions and channels. We do not include the isospin T = 3/2 contribution in our analysis.

  11. U/Th dating by SHRIMP RG ion-microprobe mass spectrometry using single ion-exchange beads

    USGS Publications Warehouse

    Bischoff, J.L.; Wooden, J.; Murphy, F.; Williams, Ross W.

    2005-01-01

    We present a new analytical method for U-series isotopes using the SHRIMP RG (Sensitive High mass Resolution Ion MicroProbe) mass spectrometer that utilizes the preconcentration of the U-series isotopes from a sample onto a single ion-exchange bead. Ion-microprobe mass spectrometry is capable of producing Th ionization efficiencies in excess of 2%. Analytical precision is typically better than alpha spectroscopy, but not as good as thermal ionization mass spectroscopy (TIMS) and inductively coupled plasma multicollector mass spectrometry (ICP-MS). Like TIMS and ICP-MS the method allows analysis of small samples sizes, but also adds the advantage of rapidity of analysis. A major advantage of ion-microprobe analysis is that U and Th isotopes are analyzed in the same bead, simplifying the process of chemical separation. Analytical time on the instrument is ???60 min per sample, and a single instrument-loading can accommodate 15-20 samples to be analyzed in a 24-h day. An additional advantage is that the method allows multiple reanalyses of the same bead and that samples can be archived for reanalysis at a later time. Because the ion beam excavates a pit only a few ??m deep, the mount can later be repolished and reanalyzed numerous times. The method described of preconcentrating a low concentration sample onto a small conductive substrate to allow ion-microprobe mass spectrometry is potentially applicable to many other systems. Copyright ?? 2005 Elsevier Ltd.

  12. A high-resolution scanning microprobe matrix-assisted laser desorption/ionization ion source for imaging analysis on an ion trap/Fourier transform ion cyclotron resonance mass spectrometer.

    PubMed

    Koestler, Martin; Kirsch, Dieter; Hester, Alfons; Leisner, Arne; Guenther, Sabine; Spengler, Bernhard

    2008-10-01

    A new scanning microprobe matrix-assisted laser desorption/ionization (SMALDI) ion source for high spatial resolution has been developed for linear ion trap and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). The source is fully compatible with commercial ion trap flanges (such as the LTQ series, Thermo Fisher Scientific). The source is designed for atmospheric pressure (AP) operation but is also suitable for mid-pressure operation. The AP mode is especially useful for investigating volatile compounds. The source can be interchanged with other ion sources within a minute when operated in the AP mode. Combining high-lateral resolution MALDI imaging with high mass resolution and high mass accuracy mass spectrometry, available in the FT-ICR mode, provides a new quality of analytical information, e.g. from biological samples. First results obtained with the new ion source demonstrate a maximum lateral resolution of 0.6 by 0.5 microm. Depending on the limit of detection of the chosen mass analyzer, however, the size of the focus had to be enlarged to a diameter of up to 8 microm in the FT-ICR mode, in order to create enough ions for detection. Mass spectra acquired for analytical imaging were obtained from single laser pulses per pixel in all the experiments. This mode allows us to investigate biological thin sections with desorption focus diameters in the micrometer range, known to cause complete evaporation of material under the laser focus with a very limited number of laser pulses. As a first example, peptide samples deposited in microstructures were investigated with the new setup. A high quality and validity of the acquired images were obtained in the ion trap mode due to the low limit of detection. High mass resolution and accuracy but poorer image quality were obtained in the ICR mode due to the lower detection sensitivity of the ICR detector. PMID:18819119

  13. Analysis of nuclear power plant construction costs

    SciTech Connect

    Not Available

    1986-01-01

    The objective of this report is to present the results of a statistical analysis of nuclear power plant construction costs and lead-times (where lead-time is defined as the duration of the construction period), using a sample of units that entered construction during the 1966-1977 period. For more than a decade, analysts have been attempting to understand the reasons for the divergence between predicted and actual construction costs and lead-times. More importantly, it is rapidly being recognized that the future of the nuclear power industry rests precariously on an improvement in the cost and lead-time situation. Thus, it is important to study the historical information on completed plants, not only to understand what has occurred to also to improve the ability to evaluate the economics of future plants. This requires an examination of the factors that have affected both the realized costs and lead-times and the expectations about these factors that have been formed during the construction process. 5 figs., 22 tabs.

  14. Seismic analysis of nuclear power plant structures

    NASA Technical Reports Server (NTRS)

    Go, J. C.

    1973-01-01

    Primary structures for nuclear power plants are designed to resist expected earthquakes of the site. Two intensities are referred to as Operating Basis Earthquake and Design Basis Earthquake. These structures are required to accommodate these seismic loadings without loss of their functional integrity. Thus, no plastic yield is allowed. The application of NASTRAN in analyzing some of these seismic induced structural dynamic problems is described. NASTRAN, with some modifications, can be used to analyze most structures that are subjected to seismic loads. A brief review of the formulation of seismic-induced structural dynamics is also presented. Two typical structural problems were selected to illustrate the application of the various methods of seismic structural analysis by the NASTRAN system.

  15. Nuclear material production cycle vulnerability analysis. Revision.

    SciTech Connect

    Bott, T.F.

    1996-10-01

    This paper discusses a method for rapidly and systematically identifying vulnerable equipment in a nuclear material or similar production process and ranking that equipment according to its attractiveness to a malevolent attacker. A multi-step approach was used in the analysis. First, the entire production cycle was modeled as a flow diagram. This flow diagram was analyzed using graph theoretical methods to identify processes in the production cycle and their locations. Models of processes that were judged to be particularly vulnerable based on the cycle analysis then were developed in greater detail to identify equipment in that process that is vulnerable to intentional damage. The information generated by this analysis may be used to devise protective features for critical equipment. The method uses directed graphs, fault trees, and evaluation matrices. Expert knowledge of plant engineers and operators is used to determine the critical equipment and evaluate its attractiveness to potential attackers. The vulnerability of equipment can be ranked and sorted according to any criterion desired and presented in a readily grasped format using matrices.

  16. The application of HPLC and microprobe NMR spectroscopy in the identification of metabolites in complex biological matrices.

    PubMed

    Miao, Zhaoxia; Jin, Mengxia; Liu, Xia; Guo, Wei; Jin, Xiangju; Liu, Hongyue; Wang, Yinghong

    2015-05-01

    Nuclear magnetic resonance (NMR)-based metabolomics can be used directly to identify a variety of metabolites in biological fluids and tissues. Metabolite analysis is an important part of life science and metabolomics research. However, the identification of some metabolites using NMR spectroscopy remains a big challenge owing to low abundance or signal overlap. It is important to develop a method to measure these compounds accurately. Two-dimensional NMR spectroscopy, metabolite prediction software packages, and spike-in experiments with authentic standards are often used to solve these problems, but they are costly and time-consuming. In this study, methods were developed to identify metabolites in complex biological mixtures using both high-performance liquid chromatography (HPLC) and off-line microprobe NMR spectroscopy. With use of these methods, 83 and 73 metabolites were identified in Sprague Dawley rat urine and feces, respectively. Among them, 40 and 45 metabolites, respectively, could not be identified with traditional NMR methods. Our research revealed that the combination of HPLC and NMR techniques could significantly improve the accuracy of trace and overlapped metabolite identification, while offering an effective and convenient approach to identify potential biomarkers in complex biological systems. PMID:25814271

  17. Applicability of trends in nuclear safety analysis to space nuclear power systems

    SciTech Connect

    Bari, R.A.

    1992-10-01

    A survey is presented of some current trends in nuclear safety analysis that may be relevant to space nuclear power systems. This includes: lessons learned from operating power reactor safety and licensing; approaches to the safety design of advanced and novel reactors and facilities; the roles of risk assessment, extremely unlikely accidents, safety goals/targets; and risk-benefit analysis and communication.

  18. Ion microprobe measurement of strontium isotopes in calcium carbonate with application to salmon otoliths

    NASA Astrophysics Data System (ADS)

    Weber, Peter K.; Bacon, Charles R.; Hutcheon, Ian D.; Ingram, B. Lynn; Wooden, Joseph L.

    2005-03-01

    The ion microprobe has the capability to generate high resolution, high precision isotopic measurements, but analysis of the isotopic composition of strontium, as measured by the 87Sr/ 86Sr ratio, has been hindered by isobaric interferences. Here we report the first high precision measurements of 87Sr/ 86Sr by ion microprobe in calcium carbonate samples with moderate Sr concentrations. We use the high mass resolving power (7000 to 9000 M.R.P.) of the SHRIMP-RG ion microprobe in combination with its high transmission to reduce the number of interfering species while maintaining sufficiently high count rates for precise isotopic measurements. The isobaric interferences are characterized by peak modeling and repeated analyses of standards. We demonstrate that by sample-standard bracketing, 87Sr/ 86Sr ratios can be measured in inorganic and biogenic carbonates with Sr concentrations between 400 and 1500 ppm with ˜2‰ external precision (2σ) for a single analysis, and subpermil external precision with repeated analyses. Explicit correction for isobaric interferences (peak-stripping) is found to be less accurate and precise than sample-standard bracketing. Spatial resolution is ˜25 μm laterally and 2 μm deep for a single analysis, consuming on the order of 2 ng of material. The method is tested on otoliths from salmon to demonstrate its accuracy and utility. In these growth-banded aragonitic structures, one-week temporal resolution can be achieved. The analytical method should be applicable to other calcium carbonate samples with similar Sr concentrations.

  19. X-ray microprobe measurements of the chemical compositions of ALH84001 carbonate globules

    SciTech Connect

    Flynn, G.J.; Sutton, S.R.; Keller, L.P.

    2004-01-28

    We measured minor element contents of carbonate from ALH84001 and report trends in tbe Ca, V, Mn and Sr in carbonate and the associated magnetite bands. McKay et al. suggested that carbonate globules in the ALH84001 meteorite from Mars contained evidence consistent with the development of bacterial life early in the history of Mars. This result provoked an extensive study of the ALH84001 meteorite. More recently Thomas-Keprta et al. have published a study showing that the magnetite associated with carbonate rims are of the size and shape produced by terrestrial bacteria. This paper has revived interest in ALH84001. The typical ALH84001 carbonate globule consists of four regions: a core of Fe-rich carbonate, a thin magnetite-rich band, a rim of Mn-rich carbonate, and another thin magnetite-rich band. Trace element analysis of each of these phases may allow us to address several important questions about these carbonates: (1) The origin of the magnetite-rich bands in the ALH84001 carbonate globules. If the magnetites are derived from the underlying carbonate through thermal decomposition (as proposed by Golden et al.), then we expect to see 'inherited' trace elements in these magnetite bands. (2) The origin of the rim carbonate, by determining whether the carbonate in the core has the same trace elements as the rim carbonates. (3) The age of the rim carbonate. Borg et al. dated the formation of the rim carbonate using the Rb/Sr chronometer. Borg et al. performed their measurements on an aliquot of what they called a high-Rb, low-Sr carbonate separate from the rim. We previously measured the trace element contents of chips from core and rim carbonates from an ALH84001 carbonate globule using an X-Ray Microprobe on Beamline X26A at the National Synchrotron Light Source. These measurements showed the rim carbonate had a very low Rb content, with Sr>>Rb, inconsistent with the {approx}5 ppm Rb reported by Borg et al. in the sample they dated by the Rb/Sr chronometer. The

  20. Radiochemistry and nuclear methods of analysis

    SciTech Connect

    Ehmann, W.D.; Vance, D.E.

    1993-01-01

    In comparison with other aspects of physical science, nuclear and radiochemistry are small contributors to the overall scheme of things. Nuclear science is, however, an important player in various aspects of medicine, life sciences, industrial technology, physical sciences, archeometry and art, and theoretical/computational sciences. This new book fills the need for a contemporary text with a good mix of simple introductory theory, experimental methodology, and instrumentation for beginning students of nuclear science.

  1. The role of electron microprobe mapping and dating in tectonic geochronology

    NASA Astrophysics Data System (ADS)

    Williams, M. L.; Jercinovic, M. J.; Dumond, G.; Mahan, K. H.; Flowers, R. M.

    2007-12-01

    Electron microprobe geochronology occupies a special niche within the spectrum of geochronological techniques and may be particularly relevant to the question, "What are we dating?" The technique was originally envisioned to be a low-cost, reconnaissance dating tool, opening low-resolution geochronology to a large number of researchers. However, more than a decade of research has shown that, when used in a reconnaissance fashion (i.e. using major-element analytical techniques for trace-element analysis) uncertainties are unsuitably large (several 10s of m.y. or more) for solving most tectonic problems. Using trace element analytical techniques (background modeling, interference correction, highly conductive coating, multi-analysis measurement, etc.) precision and accuracy are dramatically increased, but analysis time and cost are also increased, challenging the "quick, cheap, and easy" description. The power of microprobe geochronology comes from the spatial resolution and the natural integration with compositional data. High-resolution compositional mapping is valuable for all in-situ geochronology. Large area maps provide petrologic and textural context for chronometer phases; small scale maps illuminate the history of the chronometers themselves. Compositional maps associated with monazite are particularly informative, but examples from the East Athabasca granulite terrane using zircon, titanite, and rutile will be discussed. Most monazite crystals are 30μ or less and most have several compositional domains. Rim compositions and dates are particularly critical because they can commonly be tied to reactions and to matrix texture and fabric. Commonly, rims and internal sub domains are several microns in width and can only be analyzed by electron probe. Y has been widely used to tie monazite to Grt growth or breakdown, but current studies use a suite of trace and REE (Y, Sm, Nd, Ca, Eu, Gd, etc) to tie monazite into chemical reactions. A rapidly growing

  2. Electron Microprobe Techniques for Use in Tephrochronological Analyses

    NASA Astrophysics Data System (ADS)

    Fournelle, J.; Severin, K.; Wallace, K.; Beget, J.; Larsen, J.

    2006-12-01

    (1992) which followed the 1990 INQUA InterCongress Committee on Tephrochronology Workshop, e.g., use of particular standards, documentation of instrument conditions and analytical procedures, particularly volatile element treatment and matrix correction, and presentation of both tephra and standard compositional data and statistics. We suggest some modification to the recommendations regarding standards and volatile element correction. We recommend the tephra analytical community discuss and make use of this set of standardized procedures for optimizing electron microprobe analysis of volcanic glass and for reporting the data. We also recognize that no single analytical protocol may necessarily be correct for all tephra analyses, but emphasize that all relevant analytical parameters should be explicitly reported so that other laboratories could reproduce similar data on the same tephra.

  3. Electron Microprobe Analyses of Lithic Fragments and Their Minerals from Luna 20 Fines

    NASA Technical Reports Server (NTRS)

    Conrad, G. H.; Hlava, P. F.; Green, J. A.; Moore, R. B.; Moreland, G.; Dowty, E.; Prinz, M.; Keil, K.; Nehru, C. E.; Bunch, T. E.

    1973-01-01

    The bulk analyses (determined with the broad beam electron microprobe technique) of lithic fragments are given in weight percentages and are arranged according to the rock classification. Within each rock group the analyses are arranged in order of increasing FeO content. Thin section and lithic fragment numbers are given at the top of each column of analysis and correspond to the numbers recorded on photo mosaics on file in the Institute of Meteoritics. CIPW molecular norms are given for each analysis. Electron microprobe mineral analyses (given in oxide weight percentages), structural formulae and molecular end member values are presented for plagioclase, olivine, pyroxene and K-feldspar. The minerals are selected mostly from lithic fragments that were also analyzed for bulk composition. Within each mineral group the analyses are presented according to the section number and lithic fragment number. Within each lithic fragment the mineral analyses are arranged as follows: Plagioclase in order of increasing CaO; olivine and pyroexene in order of increasing FeO; and K-feldspar in order of increasing K2O. The mineral grains are identified at the top of each column of analysis by grain number and lithic fragment number.

  4. High brightness sources for MeV microprobe applications

    SciTech Connect

    Read, P.M.; Alton, G.D.; Maskrey, J.T.

    1987-01-01

    State of the art MeV ion microprobe facilities are now approaching current density limitations on targets imposed by the fundamental nature of conventional gaseous ion sources. With a view to addressing this problem efforts are under way which have the ultimate objective of developing high brightness Li liquid metal ion sources suitable for MeV ion microprobe applications. Prototype Li/sup +/ and Ga/sup +/ liquid metal ion sources have been designed, fabricated and are undergoing preliminary testing. This paper describes the first total emittance and brightness measurements of a Ga liquid metal ion source. The effect of the geometry of the ion extraction system is investigated and the brightness data are compared to those of a radio frequency ion source.

  5. Wavelength dispersive μPIXE setup for the ion microprobe

    NASA Astrophysics Data System (ADS)

    Fazinić, S.; Božičević Mihalić, I.; Tadić, T.; Cosic, D.; Jakšić, M.; Mudronja, D.

    2015-11-01

    We have developed a small wavelength dispersive X-ray spectrometer to explore the possibility of performing chemical speciation on microscopic samples utilizing focused ion beams available at the Rudjer Boskovic Institute ion microprobe. Although PIXE spectra are in principle chemically invariant, small influence of chemical effects could be observed even with Si(Li) or SDD detectors. Such chemical effects can be clearly seen with high resolution crystal X-ray spectrometers having energy resolution of several eV. A dedicated vacuum chamber, housing the diffraction crystal, sample holder and CCD X-ray detector, was constructed and positioned behind the main ion microprobe vacuum chamber. Here we will briefly describe the spectrometer, and illustrate its capabilities on measured K X-ray spectra of selected sulfur compounds. We will also demonstrate its abilities to resolve K and M X-ray lines irresolvable by solid state ED detectors usually used in PIXE.

  6. Characterization of nuclear material by Neutron Resonance Transmission Analysis

    NASA Astrophysics Data System (ADS)

    Paradela, C.; Alaerts, G.; Becker, B.; Heyse, J.; Kopecky, S.; Moens, A.; Mondelaers, W.; Schillebeeckx, P.; Wynants, R.; Harada, H.; Kitatani, F.; Koizumi, M.; Tsuchiya, H.

    2016-11-01

    The use of Neutron Resonance Transmission Analysis for the characterization of nuclear materials is discussed. The method, which relies on resonance structures in neutron-induced reaction cross sections, can be applied as a non-destructive method to characterise complex nuclear materials such as melted fuel resulting from a severe nuclear accident. Results of a demonstration experiment at the GELINA facility reveal that accurate data can be obtained at a compact facility even in the case of strong overlapping resonances.

  7. Submicron elemental mapping with the oxford scanning proton microprobe

    NASA Astrophysics Data System (ADS)

    Grime, G. W.; Watt, F.; Chapman, J. R.

    1987-03-01

    Following recent modifications to the Oxford scanning proton microprobe (SPM) a beam spot diameter of 0.5 μm has been achieved at a beam current of 20-30 pA of 4 MeV protons. This has been confirmed by scanning both a copper test grid and microcrystals of barium sulphate. The potential of using high spatial resolutions in microbiology has been explored by scanning a single mouse cell.

  8. Nuclear analytical techniques in medicine

    SciTech Connect

    Cesareo, R.

    1988-01-01

    This book acquaints one with the fundamental principles and the instrumentation relevant to analytical technique based on atomic and nuclear physics, as well as present and future biomedical applications. Besides providing a theoretical description of the physical phenomena, a large part of the book is devoted to applications in the medical and biological field, particularly in hematology, forensic medicine and environmental science. This volume reviews methods such as the possibility of carrying out rapid multi-element analysis of trace elements on biomedical samples, in vitro and in vivo, by XRF-analysis; the ability of the PIXE-microprobe to analyze in detail and to map trace elements in fragments of biomedical samples or inside the cells; the potentiality of in vivo nuclear activation analysis for diagnostic purposes. Finally, techniques are described such as radiation scattering (elastic and inelastic scattering) and attenuation measurements which will undoubtedly see great development in the immediate future.

  9. Nuclear reaction techniques in materials analysis

    SciTech Connect

    Amsel, G.; Lanford, W.A.

    1984-01-01

    This article discusses nuclear reaction microanalysis (NRA). In NRA, data accumulated in the frame of low-energy nuclear physics is put to advantage for analytical purposes. Unknown targets are bombarded and known reactions are observed. For NRA, the accelerator, detectors, spectrum recording and interpretation must be reliable, simple, and fast. Other MeV ion-beam analytical techniques are described which are complementary to NRA, such as Rutherford backscattering (RBS), proton-induced x-ray emission (PIXE), and the more recent method of elastic recoil detection (ERD). Applications for NRA range from solid-state physics and electrochemistry, semiconductor technology, metallurgy, materials science, and surface science to biology and archeology.

  10. Analysis of failed nuclear plant components

    NASA Astrophysics Data System (ADS)

    Diercks, D. R.

    1993-12-01

    Argonne National Laboratory has conducted analyses of failed components from nuclear power- gener-ating stations since 1974. The considerations involved in working with and analyzing radioactive compo-nents are reviewed here, and the decontamination of these components is discussed. Analyses of four failed components from nuclear plants are then described to illustrate the kinds of failures seen in serv-ice. The failures discussed are (1) intergranular stress- corrosion cracking of core spray injection piping in a boiling water reactor, (2) failure of canopy seal welds in adapter tube assemblies in the control rod drive head of a pressurized water reactor, (3) thermal fatigue of a recirculation pump shaft in a boiling water reactor, and (4) failure of pump seal wear rings by nickel leaching in a boiling water reactor.

  11. Multilayer Network Analysis of Nuclear Reactions.

    PubMed

    Zhu, Liang; Ma, Yu-Gang; Chen, Qu; Han, Ding-Ding

    2016-01-01

    The nuclear reaction network is usually studied via precise calculation of differential equation sets, and much research interest has been focused on the characteristics of nuclides, such as half-life and size limit. In this paper, however, we adopt the methods from both multilayer and reaction networks, and obtain a distinctive view by mapping all the nuclear reactions in JINA REACLIB database into a directed network with 4 layers: neutron, proton, (4)He and the remainder. The layer names correspond to reaction types decided by the currency particles consumed. This combined approach reveals that, in the remainder layer, the β-stability has high correlation with node degree difference and overlapping coefficient. Moreover, when reaction rates are considered as node strength, we find that, at lower temperatures, nuclide half-life scales reciprocally with its out-strength. The connection between physical properties and topological characteristics may help to explore the boundary of the nuclide chart. PMID:27558995

  12. Multilayer Network Analysis of Nuclear Reactions

    PubMed Central

    Zhu, Liang; Ma, Yu-Gang; Chen, Qu; Han, Ding-Ding

    2016-01-01

    The nuclear reaction network is usually studied via precise calculation of differential equation sets, and much research interest has been focused on the characteristics of nuclides, such as half-life and size limit. In this paper, however, we adopt the methods from both multilayer and reaction networks, and obtain a distinctive view by mapping all the nuclear reactions in JINA REACLIB database into a directed network with 4 layers: neutron, proton, 4He and the remainder. The layer names correspond to reaction types decided by the currency particles consumed. This combined approach reveals that, in the remainder layer, the β-stability has high correlation with node degree difference and overlapping coefficient. Moreover, when reaction rates are considered as node strength, we find that, at lower temperatures, nuclide half-life scales reciprocally with its out-strength. The connection between physical properties and topological characteristics may help to explore the boundary of the nuclide chart. PMID:27558995

  13. Spent Nuclear Fuel Alternative Technology Decision Analysis

    SciTech Connect

    Shedrow, C.B.

    1999-11-29

    The Westinghouse Savannah River Company (WSRC) made a FY98 commitment to the Department of Energy (DOE) to recommend a technology for the disposal of aluminum-based spent nuclear fuel (SNF) at the Savannah River Site (SRS). The two technologies being considered, direct co-disposal and melt and dilute, had been previously selected from a group of eleven potential SNF management technologies by the Research Reactor Spent Nuclear Fuel Task Team chartered by the DOE''s Office of Spent Fuel Management. To meet this commitment, WSRC organized the SNF Alternative Technology Program to further develop the direct co-disposal and melt and dilute technologies and ultimately provide a WSRC recommendation to DOE on a preferred SNF alternative management technology.

  14. Analysis of nuclear reactor instability phenomena

    SciTech Connect

    Lahey, R.T. Jr.

    1993-01-01

    The phenomena known as density-wave instability often occurs in phase change systems, such as boiling water nuclear reactors (BWRS). Our current understanding of density-wave oscillations is in fairly good shape for linear phenomena (eg, the onset of instabilities) but is not very advanced for non-linear phenomena [Lahey and Podowski, 1989]. In particular, limit cycle and chaotic instability modes are not well understood in boiling systems such as current and advanced generation BWRs (eg, SBWR). In particular, the SBWR relies on natural circulation and is thus inherently prone to problems with density-wave instabilities. The purpose of this research is to develop a quantitative understanding of nonlinear nuclear-coupled density-wave instability phenomena in BWRS. This research builds on the work of Achard et al [1985] and Clausse et al [1991] who showed, respectively, that Hopf bifurcations and chaotic oscillations may occur in boiling systems.

  15. Super-achromatic microprobe for ultrahigh-resolution endoscopic OCT imaging at 800 nm (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Yuan, Wu; Alemohammad, Milad; Yu, Xiaoyun; Yu, Shaoyong; Li, Xingde

    2016-03-01

    In this paper, we report a super-achromatic microprobe made with fiber-optic ball lens to enable ultrahigh-resolution endoscopic OCT imaging. An axial resolution of ~2.4 µm (in air) can be achieved with a 7-fs Ti:Sapphire laser. The microprobe has minimal astigmatism which affords a high transverse resolution of ~5.6 µm. The miniaturized microprobe has an outer diameter of ~520 µm including the encasing metal guard and can be used to image small luminal organs. The performance of the ultrahigh-resolution OCT microprobe was demonstrated by imaging rat esophagus, guinea pig esophagus, and mouse rectum in vivo.

  16. Electrostatic microprobe for determining charge domains on surfaces.

    PubMed

    Fletcher, Robert A

    2015-11-01

    An electrostatic microprobe was developed to measure charge on wipes and various test surfaces. The device is constructed on an optical microscope platform utilizing a computer controlled XY stage. Test surfaces can be optically imaged to identify microscopic features that can be correlated to the measured charge domain maps. The ultimate goal is to quantify charge on wipe cloths to determine the influence of electrostatic forces on wipe sampling efficiency. We found that certain wipe materials do not extensively charge while others accumulate charge by making contact with other surfaces (through the triboelectric effect). Charge domains are found to be nonuniform. PMID:26628139

  17. Electrostatic microprobe for determining charge domains on surfaces

    NASA Astrophysics Data System (ADS)

    Fletcher, Robert A.

    2015-11-01

    An electrostatic microprobe was developed to measure charge on wipes and various test surfaces. The device is constructed on an optical microscope platform utilizing a computer controlled XY stage. Test surfaces can be optically imaged to identify microscopic features that can be correlated to the measured charge domain maps. The ultimate goal is to quantify charge on wipe cloths to determine the influence of electrostatic forces on wipe sampling efficiency. We found that certain wipe materials do not extensively charge while others accumulate charge by making contact with other surfaces (through the triboelectric effect). Charge domains are found to be nonuniform.

  18. Elemental mapping of biological samples using a scanning proton microprobe

    NASA Astrophysics Data System (ADS)

    Watt, F.; Grime, G. W.

    1988-03-01

    Elemental mapping using a scanning proton microprobe (SPM) can be a powerful technique for probing trace elements in biology, allowing complex interfaces to be studied in detail, identifying contamination and artefacts present in the specimen, and in certain circumstances obtaining indirect chemical information. Examples used to illustrate the advantages of the technique include the elemental mapping of growing pollen tubes, honey bee brain section, a mouse macrophage cell, human liver section exhibiting primary biliary cirrhosis, and the attack by a mildew fungus on a pea leaf.

  19. Rapid correction of electron microprobe data for multicomponent metallic systems

    NASA Technical Reports Server (NTRS)

    Gupta, K. P.; Sivakumar, R.

    1973-01-01

    This paper describes an empirical relation for the correction of electron microprobe data for multicomponent metallic systems. It evaluates the empirical correction parameter, a for each element in a binary alloy system using a modification of Colby's MAGIC III computer program and outlines a simple and quick way of correcting the probe data. This technique has been tested on a number of multicomponent metallic systems and the agreement with the results using theoretical expressions is found to be excellent. Limitations and suitability of this relation are discussed and a model calculation is also presented in the Appendix.

  20. A High Resolution Microprobe Study of EETA79001 Lithology C

    NASA Technical Reports Server (NTRS)

    Schrader, Christian M.; Cohen, B. A.; Donovan, J. J.; Vicenzi, E. P.

    2010-01-01

    Antarctic meteorite EETA79001 has received substantial attention for possibly containing a component of Martian soil in its impact glass (Lithology C) [1]. The composition of Martian soil can illuminate near-surface processes such as impact gardening [2] and hydrothermal and volcanic activity [3,4]. Impact melts in meteorites represent our most direct samples of Martian regolith. We present the initial findings from a high-resolution electron microprobe study of Lithology C from Martian meteorite EETA79001. As this study develops we aim to extract details of a potential soil composition and to examine Martian surface processes using elemental ratios and correlations.

  1. Nuclear reactor descriptions for space power systems analysis

    NASA Technical Reports Server (NTRS)

    Mccauley, E. W.; Brown, N. J.

    1972-01-01

    For the small, high performance reactors required for space electric applications, adequate neutronic analysis is of crucial importance, but in terms of computational time consumed, nuclear calculations probably yield the least amount of detail for mission analysis study. It has been found possible, after generation of only a few designs of a reactor family in elaborate thermomechanical and nuclear detail to use simple curve fitting techniques to assure desired neutronic performance while still performing the thermomechanical analysis in explicit detail. The resulting speed-up in computation time permits a broad detailed examination of constraints by the mission analyst.

  2. Nuclear power plant fire protection: philosophy and analysis. [PWR; BWR

    SciTech Connect

    Berry, D. L.

    1980-05-01

    This report combines a fire severity analysis technique with a fault tree methodology for assessing the importance to nuclear power plant safety of certain combinations of components and systems. Characteristics unique to fire, such as propagation induced by the failure of barriers, have been incorporated into the methodology. By applying the resulting fire analysis technique to actual conditions found in a representative nuclear power plant, it is found that some safety and nonsafety areas are both highly vulnerable to fire spread and impotant to overall safety, while other areas prove to be of marginal importance. Suggestions are made for further experimental and analytical work to supplement the fire analysis method.

  3. The new external beam facility of the Oxford scanning proton microprobe

    NASA Astrophysics Data System (ADS)

    Grime, G. W.; Abraham, M. H.; Marsh, M. A.

    2001-07-01

    This paper describes the development of a high spatial resolution external beam facility on one of the beamlines of the Oxford scanning proton microprobe tandem accelerator. Using a magnetic quadrupole doublet to focus the beam through the Kapton exit window a beam diameter of <50 μm full width at half maximum (fwhm) can be achieved on a sample located at 4 mm from the exit window. The facility is equipped with two Si-Li X-ray detectors for proton-induced X-ray emission (PIXE) analysis of light and trace elements respectively, a surface barrier detector for Rutherford backscattering spectrometry (RBS) analysis and a HP-Ge detector for γ-ray detection. The mechanical and beam-optical design of the system is described.

  4. A nuclear source term analysis for spacecraft power systems

    SciTech Connect

    McCulloch, W.H.

    1998-12-01

    All US space missions involving on board nuclear material must be approved by the Office of the President. To be approved the mission and the hardware systems must undergo evaluations of the associated nuclear health and safety risk. One part of these evaluations is the characterization of the source terms, i.e., the estimate of the amount, physical form, and location of nuclear material, which might be released into the environment in the event of credible accidents. This paper presents a brief overview of the source term analysis by the Interagency Nuclear Safety Review Panel for the NASA Cassini Space Mission launched in October 1997. Included is a description of the Energy Interaction Model, an innovative approach to the analysis of potential releases from high velocity impacts resulting from launch aborts and reentries.

  5. Analysis of dinosaur samples by nuclear microscopy

    NASA Astrophysics Data System (ADS)

    Wu, Xiankang; Orlić, I.; Tang, S. M.; Wang, Yiming; Wang, Xiaohong; Zhu, Jieqing

    1997-07-01

    Several dinosaur bone and eggshell fossil samples unearthed at different sites in China were analyzed by means of nuclear microscopy. Concentrations and distributions of elements such as Na, Mg, Al, P, S, Ca, Cr, Mn, Fe, Cu, Zn, As, Br, Sr, Y, Ce, Pb and U, etc. were obtained for each sample. The results of quantitative PIXE and RBS analyses show unusually high concentrations of U and Ce in several samples obtained from a period near the K-T boundary (between Cretaceous and Tertiary periods, 65 million years ago), suggesting that some form of environmental pollution could be the cause of dinosaur extinction.

  6. Satellite nuclear power station: An engineering analysis

    NASA Technical Reports Server (NTRS)

    Williams, J. R.; Clement, J. D.; Rosa, R. J.; Kirby, K. D.; Yang, Y. Y.

    1973-01-01

    A nuclear-MHD power plant system which uses a compact non-breeder reactor to produce power in the multimegawatt range is analyzed. It is shown that, operated in synchronous orbit, the plant would transmit power safely to the ground by a microwave beam. Fuel reprocessing would take place in space, and no radioactive material would be returned to earth. Even the effect of a disastrous accident would have negligible effect on earth. A hydrogen moderated gas core reactor, or a colloid-core, or NERVA type reactor could also be used. The system is shown to approach closely the ideal of economical power without pollution.

  7. Advanced nuclear rocket engine mission analysis

    SciTech Connect

    Ramsthaler, J.; Farbman, G.; Sulmeisters, T.; Buden, D.; Harris, P.

    1987-12-01

    The use of a derivative of the NERVA engine developed from 1955 to 1973 was evluated for potential application to Air Force orbital transfer and maneuvering missions in the time period 1995 to 2020. The NERVA stge was found to have lower life cycle costs (LCC) than an advanced chemical stage for performing low earth orbit (LEO) to geosynchronous orbit (GEO0 missions at any level of activity greater than three missions per year. It had lower life cycle costs than a high performance nuclear electric engine at any level of LEO to GEO mission activity. An examination of all unmanned orbital transfer and maneuvering missions from the Space Transportation Architecture study (STAS 111-3) indicated a LCC advantage for the NERVA stage over the advanced chemical stage of fifteen million dollars. The cost advanced accured from both the orbital transfer and maneuvering missions. Parametric analyses showed that the specific impulse of the NERVA stage and the cost of delivering material to low earth orbit were the most significant factors in the LCC advantage over the chemical stage. Lower development costs and a higher thrust gave the NERVA engine an LCC advantage over the nuclear electric stage. An examination of technical data from the Rover/NERVA program indicated that development of the NERVA stage has a low technical risk, and the potential for high reliability and safe operation. The data indicated the NERVA engine had a great flexibility which would permit a single stage to perform all Air Force missions.

  8. Nuclear fuel cycle facility accident analysis handbook

    SciTech Connect

    1998-03-01

    The purpose of this Handbook is to provide guidance on how to calculate the characteristics of releases of radioactive materials and/or hazardous chemicals from nonreactor nuclear facilities. In addition, the Handbook provides guidance on how to calculate the consequences of those releases. There are four major chapters: Hazard Evaluation and Scenario Development; Source Term Determination; Transport Within Containment/Confinement; and Atmospheric Dispersion and Consequences Modeling. These chapters are supported by Appendices, including: a summary of chemical and nuclear information that contains descriptions of various fuel cycle facilities; details on how to calculate the characteristics of source terms for releases of hazardous chemicals; a comparison of NRC, EPA, and OSHA programs that address chemical safety; a summary of the performance of HEPA and other filters; and a discussion of uncertainties. Several sample problems are presented: a free-fall spill of powder, an explosion with radioactive release; a fire with radioactive release; filter failure; hydrogen fluoride release from a tankcar; a uranium hexafluoride cylinder rupture; a liquid spill in a vitrification plant; and a criticality incident. Finally, this Handbook includes a computer model, LPF No.1B, that is intended for use in calculating Leak Path Factors. A list of contributors to the Handbook is presented in Chapter 6. 39 figs., 35 tabs.

  9. Superconductive microprobes for eddy current evaluation of materials

    NASA Astrophysics Data System (ADS)

    Podney, Walter N.

    1989-07-01

    Superconductive quantum interference devices (SQUIDS) offer new technology for locating materials flaws electromagnetically that promises to increase sensitivity, depth of magnetic flux enables use of microscopic pickup loops in a gradiometer configuration to give high resolution. A cryogenic umbilical connects pickup loops to a remote cryostat housing SQUID sensors to ease scanning. A pair of drive coils a few millimeters in radius that encircle pickup loops forming a coplanar gradiometer 1 mm or less in radius comprise a superconductive microprobe. It provides a depth of field of several millimeters to a 0.1 mm flaw in an aluminum plate, when operating with a drive current a 1 A oscillating at a frequency of 1kHz. Its field of view ranges to several millimeters, for flaws a few millimeters deep, and its horizontal resolution is 1 mm or so, for flaw depths out to its depth of field. An array of microprobes form receptors much like rods in the retina of a magnetic eye. The eye leads to an electromagnetic microscope for imaging internal flaws in aluminum plates. It gives multiple images that enable resolving depth of a 0.1 mm flaw to a few tenths of a millimeter with a horizontal resolution of one millimeter or so.

  10. Friction microprobe investigation of particle layer effects on sliding friction

    SciTech Connect

    Blau, P.J.

    1993-01-01

    Interfacial particles (third-bodies), resulting from wear or external contamination, can alter and even dominate the frictional behavior of solid-solid sliding in the absence of effective particle removal processes (e.g., lubricant flow). A unique friction microprobe, developed at Oak Ridge National Laboratory, was used to conduct fine- scale friction studies using 1.0 mm diameter stainless steel spheres sliding on several sizes of loose layers of fine aluminum oxide powders on both aluminum and alumina surfaces. Conventional, pin-on-disk experiments were conducted to compare behavior with the friction microprobe results. The behavior of the relatively thick particle layers was found to be independent of the nature of underlying substrate, substantiating previous work by other investigators. The time-dependent behavior of friction, for a spherical macrocontact starting from rest, could generally be represented by a series of five rather distinct phases involving static compression, slider breakaway, transition to steady state, and dynamic layer instability. A friction model for the steady state condition, which incorporates lamellar powder layer behavior, is described.

  11. Probabilistic analysis of accident precursors in the nuclear industry.

    PubMed

    Hulsmans, M; De Gelder, P

    2004-07-26

    Feedback of operating experience has always been an important issue in the nuclear industry. A probabilistic safety analysis (PSA) can be used as a tool to analyse how an operational event might have developed adversely in order to obtain a quantitative assessment of the safety significance of the event. This process is called PSA-based event analysis (PSAEA). A comprehensive set of PSAEA guidelines was developed by an international project. The main characteristics of this methodology are summarised. This approach to analyse incidents can be used to meet different objectives of utilities or nuclear regulators. The paper describes the main objectives and the experiences of the Belgian nuclear regulatory organisation AVN with the application of PSA-based event analysis. Some interesting aspects of the process of PSAEA are further developed and underlined. Several case studies are discussed and an overview of the obtained results is given. Finally, the interest of a broad and interactive forum on PSAEA is highlighted. PMID:15231351

  12. Chemometric Analysis of Nuclear Magnetic Resonance Spectroscopy Data

    SciTech Connect

    ALAM,TODD M.; ALAM,M. KATHLEEN

    2000-07-20

    Chemometric analysis of nuclear magnetic resonance (NMR) spectroscopy has increased dramatically in recent years. A variety of different chemometric techniques have been applied to a wide range of problems in food, agricultural, medical, process and industrial systems. This article gives a brief review of chemometric analysis of NMR spectral data, including a summary of the types of mixtures and experiments analyzed with chemometric techniques. Common experimental problems encountered during the chemometric analysis of NMR data are also discussed.

  13. Analysis of valve failure data for LWR nuclear power plants

    SciTech Connect

    Schmidt, W. H.

    1980-01-01

    A computer analysis of the Nuclear Regulatory Commission (NRC) data file, compiled from Licensee Event Report (LER) data sheets, has been performed to characterize and highlight valve failures in light water reactor (LWR) nuclear power plants and provide guidance for valve improvement programs. The analysis is based on data from 1975 through 1978. Over this period, 889 valve citations were reported for pressurized water reactor (PWR) plants and 891 for boiling water reactor (BWR) plants. This report presents the pertinent LER data in a manner which indicates valve performance areas toward which improvement efforts may be directed.

  14. RABBIT: an electron microprobe data-reduction program using empirical corrections

    USGS Publications Warehouse

    Goff, Fraser E.

    1977-01-01

    RABBIT is a FORTRAN IV computer Program that uses Bence-Albee empirical corrections for the reduction of electron microprobe data of silicates, oxides, sulphates, carbonates, and phosphates. RABBIT efficiently reduces large volumes of data collected on 3-11 channel microprobes.

  15. Volatility in the lunar crust: Trace element analyses of lunar minerals by PIXE proton microprobe

    NASA Technical Reports Server (NTRS)

    Norman, M. D.; Griffin, W. L.; Ryan, C. G.

    1993-01-01

    In situ determination of mineral compositions using microbeam techniques can characterize magma compositions through mineral-melt partitioning, and be used to investigate fine-grained or rare phases which cannot be extracted for analysis. Abundances of Fe, Mn, Sr, Ga, Zr, Y, Nb, Zn, Cu, Ni, Se, and Sb were determined for various mineral phases in a small number of lunar highlands rocks using the PIXE proton microprobe. Sr/Ga ratios of plagioclase and Mn/Zn ratios of mafic silicates show that the ferroan anorthosites and Mg-suite cumulates are depleted in volatile lithophile elements to about the same degree compared with chondrites and the Earth. This links the entire lunar crust to common processes or source compositions. In contrast, secondary sulfides in Descartes breccia clasts are enriched in chalcophile elements such as Cu, Zn, Ni, Se, and Sb, and represent a potential resource in the lunar highlands.

  16. Application of laser microprobe (LAMMA 1000) to "fingerprinting" of coal constituents in bituminous coal

    USGS Publications Warehouse

    Lyons, P.C.; Hercules, D.M.; Morelli, J.J.; Sellers, G.A.; Mattern, D.; Thompson-Rizer, C. L.; Brown, F.W.; Millay, M.A.

    1987-01-01

    A laser microprobe (LAMMA-1000) microchemical analysis of vitrinites of different morphologies but similar reflectances within the same bituminous coal bed indicates distinct "fingerprint" spectra. The banded form of vitrinite contains Li, Ti, Ba, Sr, F, and Cl which were not detected in the nonbanded vitrinite. These differences may indicate a different plant source or the introduction of these elements from fluids mobilized during diagenesis. The nonbanded vitrinite (called corpocollinite), which was contained in a pyrite coal-ball seed fern permineralization of Myeloxylon, may have been protected from influx of these elements due to entrapment by pyrite during an early peat stage. An ion at M/Z 65, which is characteristic of the banded vitrinite, may indicate C5H5+ and, perhaps a difference in the chemical structure of the two vitrinites. These results demonstrate that "fingerprint" spectra can be obtained from vitrinite macerals by LAMMA and that these "fingerprints" have genetic implications. ?? 1987.

  17. 78 FR 4477 - Review of Safety Analysis Reports for Nuclear Power Plants, Introduction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-22

    ... COMMISSION Review of Safety Analysis Reports for Nuclear Power Plants, Introduction AGENCY: Nuclear... subsection to NUREG-0800, ``Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power..., Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants:...

  18. CAC - NUCLEAR THERMAL ROCKET CORE ANALYSIS CODE

    NASA Technical Reports Server (NTRS)

    Clark, J. S.

    1994-01-01

    One of the most important factors in the development of nuclear rocket engine designs is to be able to accurately predict temperatures and pressures throughout a fission nuclear reactor core with axial hydrogen flow through circular coolant passages. CAC is an analytical prediction program to study the heat transfer and fluid flow characteristics of a circular coolant passage. CAC predicts as a function of time axial and radial fluid conditions, passage wall temperatures, flow rates in each coolant passage, and approximate maximum material temperatures. CAC incorporates the hydrogen properties model STATE to provide fluid-state relations, thermodynamic properties, and transport properties of molecular hydrogen in any fixed ortho-para combination. The program requires the general core geometry, the core material properties as a function of temperature, the core power profile, and the core inlet conditions as function of time. Although CAC was originally developed in FORTRAN IV for use on an IBM 7094, this version is written in ANSI standard FORTRAN 77 and is designed to be machine independent. It has been successfully compiled on IBM PC series and compatible computers running MS-DOS with Lahey F77L, a Sun4 series computer running SunOS 4.1.1, and a VAX series computer running VMS 5.4-3. CAC requires 300K of RAM under MS-DOS, 422K of RAM under SunOS, and 220K of RAM under VMS. No sample executable is provided on the distribution medium. Sample input and output data are included. The standard distribution medium for this program is a 5.25 inch 360K MS-DOS format diskette. CAC was developed in 1966, and this machine independent version was released in 1992. IBM-PC and IBM are registered trademarks of International Business Machines. Lahey F77L is a registered trademark of Lahey Computer Systems, Inc. SunOS is a trademark of Sun Microsystems, Inc. VMS is a trademark of Digital Equipment Corporation. MS-DOS is a registered trademark of Microsoft Corporation.

  19. Electron microprobe analysis program for biological specimens: BIOMAP

    NASA Technical Reports Server (NTRS)

    Edwards, B. F.

    1972-01-01

    BIOMAP is a Univac 1108 compatible program which facilitates the electron probe microanalysis of biological specimens. Input data are X-ray intensity data from biological samples, the X-ray intensity and composition data from a standard sample and the electron probe operating parameters. Outputs are estimates of the weight percentages of the analyzed elements, the distribution of these estimates for sets of red blood cells and the probabilities for correlation between elemental concentrations. An optional feature statistically estimates the X-ray intensity and residual background of a principal standard relative to a series of standards.

  20. Neutron transport analysis for nuclear reactor design

    DOEpatents

    Vujic, J.L.

    1993-11-30

    Replacing regular mesh-dependent ray tracing modules in a collision/transfer probability (CTP) code with a ray tracing module based upon combinatorial geometry of a modified geometrical module (GMC) provides a general geometry transfer theory code in two dimensions (2D) for analyzing nuclear reactor design and control. The primary modification of the GMC module involves generation of a fixed inner frame and a rotating outer frame, where the inner frame contains all reactor regions of interest, e.g., part of a reactor assembly, an assembly, or several assemblies, and the outer frame, with a set of parallel equidistant rays (lines) attached to it, rotates around the inner frame. The modified GMC module allows for determining for each parallel ray (line), the intersections with zone boundaries, the path length between the intersections, the total number of zones on a track, the zone and medium numbers, and the intersections with the outer surface, which parameters may be used in the CTP code to calculate collision/transfer probability and cross-section values. 28 figures.

  1. Neutron transport analysis for nuclear reactor design

    DOEpatents

    Vujic, Jasmina L.

    1993-01-01

    Replacing regular mesh-dependent ray tracing modules in a collision/transfer probability (CTP) code with a ray tracing module based upon combinatorial geometry of a modified geometrical module (GMC) provides a general geometry transfer theory code in two dimensions (2D) for analyzing nuclear reactor design and control. The primary modification of the GMC module involves generation of a fixed inner frame and a rotating outer frame, where the inner frame contains all reactor regions of interest, e.g., part of a reactor assembly, an assembly, or several assemblies, and the outer frame, with a set of parallel equidistant rays (lines) attached to it, rotates around the inner frame. The modified GMC module allows for determining for each parallel ray (line), the intersections with zone boundaries, the path length between the intersections, the total number of zones on a track, the zone and medium numbers, and the intersections with the outer surface, which parameters may be used in the CTP code to calculate collision/transfer probability and cross-section values.

  2. Next Generation Nuclear Plant GAP Analysis Report

    SciTech Connect

    Ball, Sydney J; Burchell, Timothy D; Corwin, William R; Fisher, Stephen Eugene; Forsberg, Charles W.; Morris, Robert Noel; Moses, David Lewis

    2008-12-01

    As a follow-up to the phenomena identification and ranking table (PIRT) studies conducted recently by NRC on next generation nuclear plant (NGNP) safety, a study was conducted to identify the significant 'gaps' between what is needed and what is already available to adequately assess NGNP safety characteristics. The PIRT studies focused on identifying important phenomena affecting NGNP plant behavior, while the gap study gives more attention to off-normal behavior, uncertainties, and event probabilities under both normal operation and postulated accident conditions. Hence, this process also involved incorporating more detailed evaluations of accident sequences and risk assessments. This study considers thermal-fluid and neutronic behavior under both normal and postulated accident conditions, fission product transport (FPT), high-temperature metals, and graphite behavior and their effects on safety. In addition, safety issues related to coupling process heat (hydrogen production) systems to the reactor are addressed, given the limited design information currently available. Recommendations for further study, including analytical methods development and experimental needs, are presented as appropriate in each of these areas.

  3. Fuzzy risk analysis for nuclear safeguards

    SciTech Connect

    Zardecki, A.

    1993-05-01

    Analysis of a safeguards system, based on the notion of fuzzy sets and linguistic variables, concerns such as complexity and inherent imprecision in estimating the possibility of loss or compromise. The automated risk analysis allows the risk to be determined for an entire system based on estimates for lowest level components and the component proportion. In addition, for each component (asset) the most effective combination of protection mechanisms against a given set of threats is determined. A distinction between bar and featured risk is made.

  4. Fuzzy risk analysis for nuclear safeguards

    SciTech Connect

    Zardecki, A.

    1993-01-01

    Analysis of a safeguards system, based on the notion of fuzzy sets and linguistic variables, concerns such as complexity and inherent imprecision in estimating the possibility of loss or compromise. The automated risk analysis allows the risk to be determined for an entire system based on estimates for lowest level components and the component proportion. In addition, for each component (asset) the most effective combination of protection mechanisms against a given set of threats is determined. A distinction between bar and featured risk is made.

  5. Nuclear risk analysis of the Ulysses mission

    SciTech Connect

    Bartram, B.W.; Vaughan, F.R. ); Englehart, D.R.W. )

    1991-01-01

    The use of a radioisotope thermoelectric generator fueled with plutonium-238 dioxide on the Space Shuttle-launched Ulysses mission implies some level of risk due to potential accidents. This paper describes the method used to quantify risks in the Ulysses mission Final Safety Analysis Report prepared for the U.S. Department of Energy. The starting point for the analysis described herein is following input of source term probability distributions from the General Electric Company. A Monte Carlo technique is used to develop probability distributions of radiological consequences for a range of accident scenarios thoughout the mission. Factors affecting radiological consequences are identified, the probability distribution of the effect of each factor determined, and the functional relationship among all the factors established. The probability distributions of all the factor effects are then combined using a Monte Carlo technique. The results of the analysis are presented in terms of complementary cumulative distribution functions (CCDF) by mission sub-phase, phase, and the overall mission. The CCDFs show the total probability that consequences (calculated health effects) would be equal to or greater than a given value.

  6. Analysis of Operation PLUMBBOB nuclear test smoky aerial radiological data

    SciTech Connect

    Steadman, C.R. Jr.; Kennedy, N.C.; Quinn, V.E.

    1984-03-01

    This report describes the Weather Service Nuclear Support Office (WSNSO) analysis of the aerial radiological data collected following the SMOKY nuclear test of Operation PLUMBBOB. The methods of converting these aerial data to exposure rates compatible with those measured by ground-level monitors are discussed. A fallout pattern, based upon the resulting aerial exposure-rate values, is presented for the downwind area where no ground-level exposure-rate measurements were made. This WSNSO extended fallout pattern is compared with a similar analysis prepared in the late 1950s. An evaluation of the enhanced fallout areas shown in the extended pattern is made. The appendices contain discussions of the aerial data collection and analysis procedures, and contain tabulated radiological data used in the extended fallout pattern analysis. 7 references, 6 figures, 3 tables.

  7. Multi-Elemental Nuclear Analysis of soil reference material

    NASA Astrophysics Data System (ADS)

    Metairon, S.; Zamboni, C. B.; Medeiros, I. M. M. Amaral; Menezes, M. À. B. C.

    2011-08-01

    The elements concentration in the soil reference material (IAEA/SOIL-7) was obtained using the parametric Neutron Activation Analysis technique in the IEA-R1 nuclear reactor at IPEN (CNEN-SP). The results obtained were in good agreement with the respective nominal values from this reference material suggesting the viability of using this parametric procedure for environmental investigations.

  8. Ion microprobe mass spectrometry using sputtering atomization and resonance ionization

    SciTech Connect

    Donohue, D.L.; Christie, W.H.; Goeringer, D.E.

    1985-01-01

    Resonance ionization mass spectrometry (RIMS) has recently been developed into a useful technique for isotope ratio measurements. Studies performed in our laboratory (1-6) have been reported for a variety of elements using thermal vaporization sources to produce the atom reservoir for laser-induced resonance ionization. A commercial ion microprobe mass analyzer (IMMA) has been interfaced with a tunable pulsed dye laser for carrying out resonance ionization mass spectrometry of sputtered atoms. The IMMA instrument has many advantages for this work, including a micro-focused primary ion beam (2 ..mu..m in diameter) of selected mass, complete sample manipulation and viewing capability, and a double-focusing mass spectrometer for separation and detection of the secondary or laser-generated ions. Data were obtained demonstrating the number and type of ions formed along with optical spectral information showing the wavelengths at which resonance ionization occurs. 7 refs.

  9. Thin film characterization using a mechanical properties microprobe

    NASA Astrophysics Data System (ADS)

    Oliver, W. C.; McHargue, C. J.; Zinkle, S. J.

    A new ultra-low load microindentation system has been acquired in the ORNL Metals and Ceramics Division. The system's spatial resolution and its data acquisition capabilities allow the determination of several mechanical properties from volumes of material with submicron dimension; hence, the term Mechanical Properties Microprobe (MPM). Research with the MPM at Oak Ridge has led to improved techniques for determining the plastic and elastic properties of materials using microindentation experiments. The techniques have been applied to thin films created by ion implanting metals and ceramics, radiation damaged materials, and thin hard coatings of TiN. Changes in the strength (hardness) and modulus have been measured in films as thin as 200 nm.

  10. Secondary ion collection and transport system for ion microprobe

    DOEpatents

    Ward, James W.; Schlanger, Herbert; McNulty, Jr., Hugh; Parker, Norman W.

    1985-01-01

    A secondary ion collection and transport system, for use with an ion microprobe, which is very compact and occupies only a small working distance, thereby enabling the primary ion beam to have a short focal length and high resolution. Ions sputtered from the target surface by the primary beam's impact are collected between two arcuate members having radii of curvature and applied voltages that cause only ions within a specified energy band to be collected. The collected ions are accelerated and focused in a transport section consisting of a plurality of spaced conductive members which are coaxial with and distributed along the desired ion path. Relatively high voltages are applied to alternate transport sections to produce accelerating electric fields sufficient to transport the ions through the section to an ion mass analyzer, while lower voltages are applied to the other transport sections to focus the ions and bring their velocity to a level compatible with the analyzing apparatus.

  11. The Oxford scanning proton microprobe: A medical diagnostic application

    NASA Astrophysics Data System (ADS)

    Watt, F.; Grime, G. W.; Takacs, J.; Vaux, D. J. T.

    1984-04-01

    Primary biliary cirrhosis (PBC) is a disease characterised by progressive destruction of small intrahepatic bile ducts, cholestasis, and high levels of copper within the liver. The Oxford 1 μm scanning proton microprobe (SPM) has been used to construct elemental maps of a 7 μm section of diseased liver at several different magnifications. The results of these investigations have shown that the copper is distributed in small deposits ( < 5 μm) at specific locations in the liver. Further there appears to be a 1:1 atomic correlation between copper and sulphur, indicating the presence of an inorganic salt or a protein with approximately equal numbers of copper and sulphur atoms.

  12. Implementation of ionoluminescence in the AGLAE scanning external microprobe

    NASA Astrophysics Data System (ADS)

    Pichon, L.; Calligaro, T.; Gonzalez, V.; Lemasson, Q.; Moignard, B.; Pacheco, C.

    2015-04-01

    The scope of this work is to present the implementation of an IBIL imaging system in the scanning external microprobe of the AGLAE facility so as to correlate luminescence and composition maps provided by PIXE, RBS and PIGE. The challenging integration of the optical spectrometer, due to incompatibility of acquisition timings and data formats with the other IBA channels has motivated the development of a specific acquisition system. This article details the IBIL setup and explains the technical solutions retained for the coupling of IBIL with IBA techniques in order to produce fast and large IBIL-IBA maps. The IBIL maps stored in the same format as the PIXE, RBS and PIGE ones can be visualised and compared using the dedicated AGLAEmap program or the PyMCA processing package. An example of such a coupled mapping on Mesoamerican jade is presented to emphasise the interest of performing simultaneously IBA and IBIL large mappings.

  13. Micro Electron MicroProbe and Sample Analyzer

    NASA Technical Reports Server (NTRS)

    Manohara, Harish; Bearman, Gregory; Douglas, Susanne; Bronikowski, Michael; Urgiles, Eduardo; Kowalczyk, Robert; Bryson, Charles

    2009-01-01

    A proposed, low-power, backpack-sized instrument, denoted the micro electron microprobe and sample analyzer (MEMSA), would serve as a means of rapidly performing high-resolution microscopy and energy-dispersive x-ray spectroscopy (EDX) of soil, dust, and rock particles in the field. The MEMSA would be similar to an environmental scanning electron microscope (ESEM) but would be much smaller and designed specifically for field use in studying effects of geological alteration at the micrometer scale. Like an ESEM, the MEMSA could be used to examine uncoated, electrically nonconductive specimens. In addition to the difference in size, other significant differences between the MEMSA and an ESEM lie in the mode of scanning and the nature of the electron source.

  14. Multiscale Methods for Nuclear Reactor Analysis

    NASA Astrophysics Data System (ADS)

    Collins, Benjamin S.

    The ability to accurately predict local pin powers in nuclear reactors is necessary to understand the mechanisms that cause fuel pin failure during steady state and transient operation. In the research presented here, methods are developed to improve the local solution using high order methods with boundary conditions from a low order global solution. Several different core configurations were tested to determine the improvement in the local pin powers compared to the standard techniques, that use diffusion theory and pin power reconstruction (PPR). Two different multiscale methods were developed and analyzed; the post-refinement multiscale method and the embedded multiscale method. The post-refinement multiscale methods use the global solution to determine boundary conditions for the local solution. The local solution is solved using either a fixed boundary source or an albedo boundary condition; this solution is "post-refinement" and thus has no impact on the global solution. The embedded multiscale method allows the local solver to change the global solution to provide an improved global and local solution. The post-refinement multiscale method is assessed using three core designs. When the local solution has more energy groups, the fixed source method has some difficulties near the interface: however the albedo method works well for all cases. In order to remedy the issue with boundary condition errors for the fixed source method, a buffer region is used to act as a filter, which decreases the sensitivity of the solution to the boundary condition. Both the albedo and fixed source methods benefit from the use of a buffer region. Unlike the post-refinement method, the embedded multiscale method alters the global solution. The ability to change the global solution allows for refinement in areas where the errors in the few group nodal diffusion are typically large. The embedded method is shown to improve the global solution when it is applied to a MOX/LEU assembly

  15. Deep Space 2: The Mars Microprobe Project and Beyond

    NASA Technical Reports Server (NTRS)

    Smrekar, S. E.; Gavit, S. A.

    1998-01-01

    The Mars Microprobe Project, or Deep Space 2 (DS2), is the second of the New Millennium Program planetary missions and is designed to enable future space science network missions through flight validation of new technologies. A secondary goal is the collection of meaningful science data. Two micropenetrators will be deployed to carry out surface and subsurface science. The penetrators are being carried as a piggyback payload on the Mars Polar Lander cruise ring and will be launched in January 1999. The microprobe has no active control, attitude determination, or propulsive systems. It is a single stage from separation until landing and will passively orient itself due to its aerodynamic design. The aeroshell will be made of a nonerosive heat shield material, Silicon impregnated Reusable Ceramic Ablator(SIRCA), developed at Ames Research Center. The aeroshell shatters on impact, at which time the probe separates into an aftbody that remains at the surface and a forebody that penetrates into the subsurface. Each probe has a total mass of up to 3 kg, including the aeroshell. The impact velocity will be about 180 meters per second. The forebody will experience up to 30,000 g's and penetrate between 0.3 and 2 meters, depending on the ice content of the soil. The aftbody deceleration will be up to 80,000 g. The penetrators arrive in December 1999. The landing ellipse latitude range is 73 deg-77 deg S. The longitude will be selected by the Mars Surveyor Project to place the lander on the polar layered deposits in the range of 180 deg -230 deg W. The two micropenetrators are likely to land within 100 km of the Mars Surveyor Lander, on the polar deposits. The likely arrival date is L(sub s) = 256, late southern spring. The nominal mission lasts 2 days. A science team was selected in April 1998.

  16. Deep Space 2: The Mars Microprobe Project and Beyond

    NASA Astrophysics Data System (ADS)

    Smrekar, S. E.; Gavit, S. A.

    1998-01-01

    The Mars Microprobe Project, or Deep Space 2 (DS2), is the second of the New Millennium Program planetary missions and is designed to enable future space science network missions through flight validation of new technologies. A secondary goal is the collection of meaningful science data. Two micropenetrators will be deployed to carry out surface and subsurface science. The penetrators are being carried as a piggyback payload on the Mars Polar Lander cruise ring and will be launched in January 1999. The microprobe has no active control, attitude determination, or propulsive systems. It is a single stage from separation until landing and will passively orient itself due to its aerodynamic design. The aeroshell will be made of a nonerosive heat shield material, Silicon impregnated Reusable Ceramic Ablator(SIRCA), developed at Ames Research Center. The aeroshell shatters on impact, at which time the probe separates into an aftbody that remains at the surface and a forebody that penetrates into the subsurface. Each probe has a total mass of up to 3 kg, including the aeroshell. The impact velocity will be about 180 meters per second. The forebody will experience up to 30,000 g's and penetrate between 0.3 and 2 meters, depending on the ice content of the soil. The aftbody deceleration will be up to 80,000 g. The penetrators arrive in December 1999. The landing ellipse latitude range is 73 deg-77 deg S. The longitude will be selected by the Mars Surveyor Project to place the lander on the polar layered deposits in the range of 180 deg -230 deg W. The two micropenetrators are likely to land within 100 km of the Mars Surveyor Lander, on the polar deposits. The likely arrival date is Ls = 256, late southern spring. The nominal mission lasts 2 days. A science team was selected in April 1998.

  17. Nuclear Thermal Propulsion Mars Mission Systems Analysis and Requirements Definition

    NASA Technical Reports Server (NTRS)

    Mulqueen, Jack; Chiroux, Robert C.; Thomas, Dan; Crane, Tracie

    2007-01-01

    This paper describes the Mars transportation vehicle design concepts developed by the Marshall Space Flight Center (MSFC) Advanced Concepts Office. These vehicle design concepts provide an indication of the most demanding and least demanding potential requirements for nuclear thermal propulsion systems for human Mars exploration missions from years 2025 to 2035. Vehicle concept options vary from large "all-up" vehicle configurations that would transport all of the elements for a Mars mission on one vehicle. to "split" mission vehicle configurations that would consist of separate smaller vehicles that would transport cargo elements and human crew elements to Mars separately. Parametric trades and sensitivity studies show NTP stage and engine design options that provide the best balanced set of metrics based on safety, reliability, performance, cost and mission objectives. Trade studies include the sensitivity of vehicle performance to nuclear engine characteristics such as thrust, specific impulse and nuclear reactor type. Tbe associated system requirements are aligned with the NASA Exploration Systems Mission Directorate (ESMD) Reference Mars mission as described in the Explorations Systems Architecture Study (ESAS) report. The focused trade studies include a detailed analysis of nuclear engine radiation shield requirements for human missions and analysis of nuclear thermal engine design options for the ESAS reference mission.

  18. Constraining the symmetry energy content of nuclear matter from nuclear masses: A covariance analysis

    NASA Astrophysics Data System (ADS)

    Mondal, C.; Agrawal, B. K.; De, J. N.

    2015-08-01

    Elements of nuclear symmetry energy evaluated from different energy density functionals parametrized by fitting selective bulk properties of few representative nuclei are seen to vary widely. Those obtained from experimental data on nuclear masses across the periodic table, however, show that they are better constrained. A possible direction in reconciling this paradox may be gleaned from comparison of results obtained from use of the binding energies in the fitting protocol within a microscopic model with two sets of nuclei, one a representative standard set and another where very highly asymmetric nuclei are additionally included. A covariance analysis reveals that the additional fitting protocol reduces the uncertainties in the nuclear symmetry energy coefficient, its slope parameter, as well as the neutron-skin thickness in 208Pb nucleus by ˜50 % . The central values of these entities are also seen to be slightly reduced.

  19. Analysis of the transient response of nuclear spins in GaAs with/without nuclear magnetic resonance

    NASA Astrophysics Data System (ADS)

    Rasly, Mahmoud; Lin, Zhichao; Yamamoto, Masafumi; Uemura, Tetsuya

    2016-05-01

    As an alternative to studying the steady-state responses of nuclear spins in solid state systems, working within a transient-state framework can reveal interesting phenomena. The response of nuclear spins in GaAs to a changing magnetic field was analyzed based on the time evolution of nuclear spin temperature. Simulation results well reproduced our experimental results for the transient oblique Hanle signals observed in an all-electrical spin injection device. The analysis showed that the so called dynamic nuclear polarization can be treated as a cooling tool for the nuclear spins: It works as a provider to exchange spin angular momentum between polarized electron spins and nuclear spins through the hyperfine interaction, leading to an increase in the nuclear polarization. In addition, a time-delay of the nuclear spin temperature with a fast sweep of the external magnetic field produces a possible transient state for the nuclear spin polarization. On the other hand, the nuclear magnetic resonance acts as a heating tool for a nuclear spin system. This causes the nuclear spin temperature to jump to infinity: i.e., the average nuclear spins along with the nuclear field vanish at resonant fields of 75As, 69Ga and 71Ga, showing an interesting step-dip structure in the oblique Hanle signals. These analyses provide a quantitative understanding of nuclear spin dynamics in semiconductors for application in future computation processing.

  20. PBMR nuclear design and safety analysis: An overview

    SciTech Connect

    Stoker, C.

    2006-07-01

    PBMR is a high-temperature helium-cooled graphite-moderated continuous-fuelled pebble bed reactor. The power conversion unit is directly coupled to the reactor and the power turbines are driven through a direct closed-circuit helium cycle. An overview is presented on the nuclear engineering analyses used for the design and safety assessment for the PBMR. Topics addressed are the PBMR design, safety and licensing requirements, nuclear engineering analysis results, software verification and validation, and advances in software development. (authors)

  1. Analysis of evaporation in nuclear waste boreholes in unsaturated tuff

    SciTech Connect

    Zhou, W.; Chambre, P.L.; Pigford, T.H.; Lee, W.W.L.

    1993-12-31

    We present an analysis of evaporation in a nuclear waste borehole in unsaturated tuff. In unsaturated tuff, water in contact with a waste container will evaporate due to the difference in vapor pressure between water in a flat film and water held in rock pores with curved interfaces. Decay heat will also enhance evaporation. It is important to study evaporation in a potential geologic repository of nuclear waste in unsaturated rock because the corrosion of waste containers is increased with liquid water. For radionuclides other than gaseous ones, their release from waste solids requires liquid water.

  2. Nuclear monitoring by nonradioactive noble gas sampling and analysis

    SciTech Connect

    Fearey, B.L.; Nakhleh, C.W.; Stanbro, W.D.

    1997-10-01

    This is the final report of a two-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The perceived importance of measuring the xenon and krypton isotopics of nuclear activities has increased substantially in recent years. We have performed a systems analysis and theoretical simulation of the production, atmospheric dispersion, and isotopic abundances of noble-gas fission products, addressing several questions of interest, including: the relative isotopic variation as a function of nuclear fuel composition, reactor operational history, reactor type, distance from stack, and ambient meteorological conditions. Of particular importance in this analysis was the question of back-calculating process parameters of interest given noble-gas isotopic data. An analysis of the effect of measurement uncertainties was also performed. The results of these analyses indicate that this monitoring concept should be experimentally feasible.

  3. ADDING REALISM TO NUCLEAR MATERIAL DISSOLVING ANALYSIS

    SciTech Connect

    Williamson, B.

    2011-08-15

    Two new criticality modeling approaches have greatly increased the efficiency of dissolver operations in H-Canyon. The first new approach takes credit for the linear, physical distribution of the mass throughout the entire length of the fuel assembly. This distribution of mass is referred to as the linear density. Crediting the linear density of the fuel bundles results in using lower fissile concentrations, which allows higher masses to be charged to the dissolver. Also, this approach takes credit for the fact that only part of the fissile mass is wetted at a time. There are multiple assemblies stacked on top of each other in a bundle. On average, only 50-75% of the mass (the bottom two or three assemblies) is wetted at a time. This means that only 50-75% (depending on operating level) of the mass is moderated and is contributing to the reactivity of the system. The second new approach takes credit for the progression of the dissolving process. Previously, dissolving analysis looked at a snapshot in time where the same fissile material existed both in the wells and in the bulk solution at the same time. The second new approach models multiple consecutive phases that simulate the fissile material moving from a high concentration in the wells to a low concentration in the bulk solution. This approach is more realistic and allows higher fissile masses to be charged to the dissolver.

  4. In-field analysis and assessment of nuclear material

    SciTech Connect

    Morgado, R.E.; Myers, W.S.; Olivares, J.A.; Phillips, J.R.; York, R.L.

    1996-05-01

    Los Alamos National Laboratory has actively developed and implemented a number of instruments to monitor, detect, and analyze nuclear materials in the field. Many of these technologies, developed under existing US Department of Energy programs, can also be used to effectively interdict nuclear materials smuggled across or within national borders. In particular, two instruments are suitable for immediate implementation: the NAVI-2, a hand-held gamma-ray and neutron system for the detection and rapid identification of radioactive materials, and the portable mass spectrometer for the rapid analysis of minute quantities of radioactive materials. Both instruments provide not only critical information about the characteristics of the nuclear material for law-enforcement agencies and national authorities but also supply health and safety information for personnel handling the suspect materials.

  5. Hydrogen release from irradiated elastomers measured by Nuclear Reaction Analysis

    NASA Astrophysics Data System (ADS)

    Jagielski, J.; Ostaszewska, U.; Bielinski, D. M.; Grambole, D.; Romaniec, M.; Jozwik, I.; Kozinski, R.; Kosinska, A.

    2016-03-01

    Ion irradiation appears as an interesting method of modification of elastomers, especially friction and wear properties. Main structural effect caused by heavy ions is a massive loss of hydrogen from the surface layer leading to its smoothening and shrinking. The paper presents the results of hydrogen release from various elastomers upon irradiation with H+, He+ and Ar+ studied by using Nuclear Reaction Analysis (NRA) method. The analysis of the experimental data indicates that the hydrogen release is controlled by inelastic collisions between ions and target electrons. The last part of the study was focused on preliminary analysis of mechanical properties of irradiated rubbers.

  6. An analysis of international nuclear fuel supply options

    NASA Astrophysics Data System (ADS)

    Taylor, J'tia Patrice

    As the global demand for energy grows, many nations are considering developing or increasing nuclear capacity as a viable, long-term power source. To assess the possible expansion of nuclear power and the intricate relationships---which cover the range of economics, security, and material supply and demand---between established and aspirant nuclear generating entities requires models and system analysis tools that integrate all aspects of the nuclear enterprise. Computational tools and methods now exist across diverse research areas, such as operations research and nuclear engineering, to develop such a tool. This dissertation aims to develop methodologies and employ and expand on existing sources to develop a multipurpose tool to analyze international nuclear fuel supply options. The dissertation is comprised of two distinct components: the development of the Material, Economics, and Proliferation Assessment Tool (MEPAT), and analysis of fuel cycle scenarios using the tool. Development of MEPAT is aimed for unrestricted distribution and therefore uses publicly available and open-source codes in its development when possible. MEPAT is built using the Powersim Studio platform that is widely used in systems analysis. MEPAT development is divided into three modules focusing on: material movement; nonproliferation; and economics. The material movement module tracks material quantity in each process of the fuel cycle and in each nuclear program with respect to ownership, location and composition. The material movement module builds on techniques employed by fuel cycle models such as the Verifiable Fuel Cycle Simulation (VISION) code developed at the Idaho National Laboratory under the Advanced Fuel Cycle Initiative (AFCI) for the analysis of domestic fuel cycle. Material movement parameters such as lending and reactor preference, as well as fuel cycle parameters such as process times and material factors are user-specified through a Microsoft Excel(c) data spreadsheet

  7. NUCLEAR DATA RESOURCES FOR ADVANCED ANALYSIS AND SIMULATION.

    SciTech Connect

    PRITYCHENKO, B.

    2006-06-05

    The mission of the National Nuclear Data Center (NNDC) includes collection, evaluation, and dissemination of nuclear physics data for basic nuclear research and applied nuclear technologies. In 2004, to answer the needs of nuclear data users, NNDC completed a project to modernize storage and management of its databases and began offering new nuclear data Web services. Examples of nuclear reaction, nuclear structure and decay database applications along with a number of nuclear science codes are also presented.

  8. A human reliability analysis of a nuclear explosives dismantlement

    SciTech Connect

    Bott, T.F.

    1995-07-01

    This paper describes the methodology used in a human reliability analysis (HRA) conducted during a quantitative hazard assessment of a nuclear weapon disassembly process performed at the Pantex plant. The probability of human errors during the disassembly process is an extremely important aspect of estimating accident-sequence frequency for nuclear weapons processing. The methods include the systematic identification of potential human-initiated or enabled accident sequences using an accident-sequence fault tree, the extensive use of walkthroughs and videotaping of the disassembly process, and hands-on testing of postulated human errors. THERP modeling of rule-based behavior and operational data analysis of errors in skill-based behavior are described. A simple method for evaluating the approximate likelihood of nonmalevolent violations of procedures was developed and used to examine the process. The HRA occurred concurrently with process design, so considerable interaction between the analysts and designers occurred and resulted in design changes that are discussed in the paper.

  9. Analysis of DOE Spent Nuclear Fuels for Repository Disposal

    SciTech Connect

    L.F. Pincock; W.D. Hintze; J. Duguid

    2006-02-07

    U.S. Department of Energy (DOE) spent nuclear fuel (SNF) consists of hundreds of different fuel types in various conditions. In order to analyze and model the DOE SNF for its suitability for repository disposal, several generalizations and simplifications were necessary. This paper describes the methodology used to arrive at a suitable DOE SNF surrogate and summarizes the proposed analysis of this DOE SNF surrogate for its appropriateness as a representative SNF.

  10. A combination of size-resolved particle samplers and XRF microprobe technique for single particle study

    NASA Astrophysics Data System (ADS)

    Ma, Chang-Jin; Kim, Ki-Hyun

    It is important to understand the properties of individual airborne particulates that are determined by the processes of various physicochemical reactions occurring in their generation, transformation, and transport. This study describes the application of the X-ray fluorescence (XRF) microprobe technique to the analysis of size-resolved individual particles as well as the results of an experimental study on the comparison of three different particle collection instruments for single particle analysis: a two-stage filter pack, a low pressure Andersen impactor (LPAI), and a micro-orifice uniform deposit impactor (MOUDI). Though LPAI and MOUDI are relatively suitable for multisize-segregated particles sampling compared with the two-stage filter pack sampler, they can easily form particle clusters and finally these particle clusters impede single particle analysis. Even though more particle mass can be collected without overloading on the substrate using MOUDI, by stage rotating, particles are still deposited and form clusters on the concentric circles. When particles are forming a spot (or other shapes of particle cluster), single particle analysis using the XRF micro-beam technique is restricted to individual particles deposited at the edge of the spot. Thus, the sampling duration time depending on the sampler stage should be adjusted for single particle study.

  11. Vulnerability Analysis Considerations for the Transportation of Special Nuclear Material

    SciTech Connect

    Nicholson, Lary G.; Purvis, James W.

    1999-07-21

    The vulnerability analysis methodology developed for fixed nuclear material sites has proven to be extremely effective in assessing associated transportation issues. The basic methods and techniques used are directly applicable to conducting a transportation vulnerability analysis. The purpose of this paper is to illustrate that the same physical protection elements (detection, delay, and response) are present, although the response force plays a dominant role in preventing the theft or sabotage of material. Transportation systems are continuously exposed to the general public whereas the fixed site location by its very nature restricts general public access.

  12. Enhanced Raman Microprobe Imaging of Single-Wall Carbon Nanotubes

    NASA Technical Reports Server (NTRS)

    Hadjiev, V. G.; Arepalli, S.; Nikolaev, P.; Jandl, S.; Yowell, L.

    2003-01-01

    We explore Raman microprobe capabilities to visualize single wall carbon nanotubes (SWCNTs). Although this technique is limited to a micron scale, we demonstrate that images of individual SWCNTs, bundles or their agglomerates can be generated by mapping Raman active elementary excitations. We measured the Raman response from carbon vibrations in SWCNTs excited by confocal scanning of a focused laser beam. Carbon vibrations reveal key characteristics of SWCNTs as nanotube diameter distribution (radial breathing modes, RBM, 100-300 cm(exp -1)), presence of defects and functional groups (D-mode, 1300-1350 cm(exp -1)), strain and oxidation states of SWCNTs, as well as metallic or semiconducting character of the tubes encoded in the lineshape of the G-modes at 1520-1600 cm(exp - 1). In addition, SWCNTs are highly anisotropic scatterers. The Raman response from a SWCNT is maximal for incident light polarization parallel to the tube axis and vanishing for perpendicular directions. We show that the SWCNT bundle shape or direction can be determined, with some limitations, from a set of Raman images taken at two orthogonal directions of the incident light polarization.

  13. Raman microprobe spectroscopic studies of solid DNA-CTMA films

    NASA Astrophysics Data System (ADS)

    Yaney, Perry P.; Ahmad, Faizan; Grote, James G.

    2008-08-01

    Extensive studies have been carried out on developing the new biopolymer, deoxyribonucleic acid (DNA) derived from salmon, that has been complexed with a surfactant to make it water insoluble for application to bioelectronic and biophotonic devices. One of the key issues associated with the properties and behavior of solid films of this material is the extreme size of the >8 MDa molecular weight of the virgin, as-received material. Reduction of this molecular weight by factors of up to 40 is achieved by high power sonication. To support the various measurements that have been made to confirm that the sonicated material is still double strand DNA and to look for other effects of sonication, Raman studies were carried out to compare the spectra over a wide range of molecular weights and to develop baseline data that can be used in intercolation studies where various dopants are added to change the electrical, mechanical or optical properties. Raman microprobe spectra from solid, dry thin films of DNA with molecular weights ranging from 200 kDa to >8 MDa complexed with cetyltrimethyl-ammonium chloride (CTMA) are reported and compared to the as-received spectrum and to published DNA spectra in aqueous solutions. In addition, microscopy and measurements on macro-molecular structures of DNA-CTMA are reported.

  14. Identification of cosmogenic argon components in Allende by laser microprobe

    NASA Technical Reports Server (NTRS)

    Kirschbaum, C.

    1986-01-01

    New techniques are presented for using a laser microprobe to determine the spallation argon systematics of calcium-aluminum inclusions. The Ar-38(s) amounts determined for melilite and anorthite in a coarse-grained inclusion from Allende are 2.9 x 10 to the -8th and 1.3 x 10 to the -8th cc/g, respectively. The ratio of the amounts is consistent with the calcium contents of these two minerals. The Ar-38(s) amount determined for a fine-grained inclusion from Allende is 1.1 x 10 to the -8th cc/g. Calcium and potassium amounts were determined from irradiated samples of the same inclusions so that production of Ar-38 from calcium during the cosmic ray exposure of Allende could be determined for these samples. The production observed was 12.4 + or - 2.1 x 10 to the -8th cc STP Ar-38/g Ca for the coarse-grained inclusion and 9.9 + or - 2.4 cc STP Ar-38/g Ca for the fine-grained inclusion. No evidence of unusual exposure was observed in the two inclusions studied.

  15. [Investigation of Carbonaceous Airborne Particles by Scanning Proton Microprobe].

    PubMed

    Bao, Liang-man; Liu, Jiang-feng; Lei, Qian-tao; Li, Xiao-lin; Zhang, Gui-lin; Li, Yan

    2016-01-15

    Carbonaceous particles are an important component of the atmospheric aerosol particles and important for global climate change, air quality and human health. The PM₁₀ single particles from two environmental monitor locations and seven pollution emission sources were analyzed using scanning proton microprobe (SPM) techniques. The concentration of carbon in individual particles was quantitatively determined by proton non-Rutherford elastic backscattering spectrometry (EBS). The results of this investigation showed that carbonaceous particles were dominant in the pollution sources of coal and oil combustions, diesel busexhaust and automobile exhaust, while inorganic particles were dominant in the sources of steel industry, cement dust and soil dust. Carbonaceous matter was enriched in particles from the city center, while mineral matter was the main component of airborne particles in the industrial area. Elemental mapping of single aerosol particles yielded important information on the chemical reactions of aerosol particles. The micro-PIXE (particle induced X-ray emission) maps of S, Ca and Fe of individual carbonaceous particles showed that sulfuration reaction occurred between SO₂and mineral particles, which increased the sulfur content of particles. PMID:27078933

  16. Stanford-USGS shrimp-RG ion microprobe: A new approach to determining the distribution of trace elements in coal

    USGS Publications Warehouse

    Kolker, A.; Wooden, J.L.; Persing, H.M.; Zielinski, R.A.

    2000-01-01

    The distribution of Cr and other trace metals of environmental interest in a range of widely used U.S. coals was investigated using the Stanford-USGS SHRIMP-RG ion microprobe . Using the oxygen ion source, concentrations of Cr (11 to 176 ppm), V (23 to 248 ppm), Mn (2 to 149 ppm), Ni (2 to 30 ppm), and 13 other elements were determined in illite/smectite, a group of clay minerals commonly present in coal. The results confirm previous indirect or semi-quantitative determinations indicating illite/smectite to be an important host of these metals. Calibration was achieved using doped aluminosilicate-glass synthetic standards and glasses prepared from USGS rock standards. Grains for analysis were identified optically, and confirmed by 1) precursory electron microprobe analysis and wavelength-dispersive compositional mapping, and 2) SHRIMP-RG major element data obtained concurrently with trace element results. Follow-up investigations will focus on the distribution of As and other elements that are more effectively ionized with the cesium primary beam currently being tested.

  17. Safety analysis of irradiated nuclear fuel transportation container

    SciTech Connect

    Uspuras, E.; Rimkevicius, S.

    2007-07-01

    Ignalina NPP comprises two Units with RBMK-1500 reactors. After the Unit 1 of the Ignalina Nuclear Power Plant was shut down in 2004, approximately 1000 fuel assemblies from Unit were available for further reuse in Unit 2. The fuel-transportation container, vehicle, protection shaft and other necessary equipment were designed in order to implement the process for on-site transportation of Unit 1 fuel for reuse in the Unit 2. The Safety Analysis Report (SAR) was developed to demonstrate that the proposed set of equipment performs all functions and assures the required level of safety for both normal operation and accident conditions. The purpose of this paper is to introduce the content and main results of SAR, focusing attention on the container used to transport spent fuel assemblies from Unit I on Unit 2. In the SAR, the structural integrity, thermal, radiological and nuclear safety calculations are performed to assess the acceptance of the proposed set of equipment. The safety analysis demonstrated that the proposed nuclear fuel transportation container and other equipment are in compliance with functional, design and regulatory requirements and assure the required safety level. (authors)

  18. INTEGRATION OF FACILITY MODELING CAPABILITIES FOR NUCLEAR NONPROLIFERATION ANALYSIS

    SciTech Connect

    Gorensek, M.; Hamm, L.; Garcia, H.; Burr, T.; Coles, G.; Edmunds, T.; Garrett, A.; Krebs, J.; Kress, R.; Lamberti, V.; Schoenwald, D.; Tzanos, C.; Ward, R.

    2011-07-18

    Developing automated methods for data collection and analysis that can facilitate nuclear nonproliferation assessment is an important research area with significant consequences for the effective global deployment of nuclear energy. Facility modeling that can integrate and interpret observations collected from monitored facilities in order to ascertain their functional details will be a critical element of these methods. Although improvements are continually sought, existing facility modeling tools can characterize all aspects of reactor operations and the majority of nuclear fuel cycle processing steps, and include algorithms for data processing and interpretation. Assessing nonproliferation status is challenging because observations can come from many sources, including local and remote sensors that monitor facility operations, as well as open sources that provide specific business information about the monitored facilities, and can be of many different types. Although many current facility models are capable of analyzing large amounts of information, they have not been integrated in an analyst-friendly manner. This paper addresses some of these facility modeling capabilities and illustrates how they could be integrated and utilized for nonproliferation analysis. The inverse problem of inferring facility conditions based on collected observations is described, along with a proposed architecture and computer framework for utilizing facility modeling tools. After considering a representative sampling of key facility modeling capabilities, the proposed integration framework is illustrated with several examples.

  19. Integration of facility modeling capabilities for nuclear nonproliferation analysis

    SciTech Connect

    Garcia, Humberto; Burr, Tom; Coles, Garill A; Edmunds, Thomas A.; Garrett, Alfred; Gorensek, Maximilian; Hamm, Luther; Krebs, John; Kress, Reid L; Lamberti, Vincent; Schoenwald, David; Tzanos, Constantine P; Ward, Richard C

    2012-01-01

    Developing automated methods for data collection and analysis that can facilitate nuclear nonproliferation assessment is an important research area with significant consequences for the effective global deployment of nuclear energy. Facility modeling that can integrate and interpret observations collected from monitored facilities in order to ascertain their functional details will be a critical element of these methods. Although improvements are continually sought, existing facility modeling tools can characterize all aspects of reactor operations and the majority of nuclear fuel cycle processing steps, and include algorithms for data processing and interpretation. Assessing nonproliferation status is challenging because observations can come from many sources, including local and remote sensors that monitor facility operations, as well as open sources that provide specific business information about the monitored facilities, and can be of many different types. Although many current facility models are capable of analyzing large amounts of information, they have not been integrated in an analyst-friendly manner. This paper addresses some of these facility modeling capabilities and illustrates how they could be integrated and utilized for nonproliferation analysis. The inverse problem of inferring facility conditions based on collected observations is described, along with a proposed architecture and computer framework for utilizing facility modeling tools. After considering a representative sampling of key facility modeling capabilities, the proposed integration framework is illustrated with several examples.

  20. Systems analysis of solid fuel nuclear engines in cislunar space

    NASA Astrophysics Data System (ADS)

    Thomas, U.; Koelle, H. H.; Balzer-Sieb, R.; Bernau, D.; Czarnitzki, J.; Floete, A.; Goericke, D.; Lindenthal, A.; Protsch, R.; Teschner, O.

    1984-12-01

    The use of nuclear engines in cislunar space was studied and the restrictions imposed on nuclear ferries by the chemical Earth to lower Earth orbit (LEO) transportation system were analyzed. The operating conditions are best met by tungsten-water-moderated reactors due to a high specific impulse and long durability. Specific transportation cost for LEO to geostationary orbit (GEO) and LEO to lunar orbit flights were calculated for a transportation system life of 50 yr. Average transportation costs are estimated to be 141 $/kg. No difference is made for both routes. An additional analysis of smaller and larger flight units shows only small cost reductions by employing larger ferries but a significant cost increase in case smaller flight units are used.

  1. SCALE 6: Comprehensive Nuclear Safety Analysis Code System

    SciTech Connect

    Bowman, Stephen M

    2011-01-01

    Version 6 of the Standardized Computer Analyses for Licensing Evaluation (SCALE) computer software system developed at Oak Ridge National Laboratory, released in February 2009, contains significant new capabilities and data for nuclear safety analysis and marks an important update for this software package, which is used worldwide. This paper highlights the capabilities of the SCALE system, including continuous-energy flux calculations for processing multigroup problem-dependent cross sections, ENDF/B-VII continuous-energy and multigroup nuclear cross-section data, continuous-energy Monte Carlo criticality safety calculations, Monte Carlo radiation shielding analyses with automated three-dimensional variance reduction techniques, one- and three-dimensional sensitivity and uncertainty analyses for criticality safety evaluations, two- and three-dimensional lattice physics depletion analyses, fast and accurate source terms and decay heat calculations, automated burnup credit analyses with loading curve search, and integrated three-dimensional criticality accident alarm system analyses using coupled Monte Carlo criticality and shielding calculations.

  2. Nuclear Cryogenic Propulsion Stage Conceptual Design and Mission Analysis

    NASA Technical Reports Server (NTRS)

    Kos, Larry D.; Russell, Tiffany E.

    2014-01-01

    The Nuclear Cryogenic Propulsion Stage (NCPS) is an in-space transportation vehicle, comprised of three main elements, designed to support a long-stay human Mars mission architecture beginning in 2035. The stage conceptual design and the mission analysis discussed here support the current nuclear thermal propulsion going on within partnership activity of NASA and the Department of Energy (DOE). The transportation system consists of three elements: 1) the Core Stage, 2) the In-line Tank, and 3) the Drop Tank. The driving mission case is the piloted flight to Mars in 2037 and will be the main point design shown and discussed. The corresponding Space Launch System (SLS) launch vehicle (LV) is also presented due to it being a very critical aspect of the NCPS Human Mars Mission architecture due to the strong relationship between LV lift capability and LV volume capacity.

  3. Radionuclide Analysis on Bamboos following the Fukushima Nuclear Accident

    PubMed Central

    Higaki, Takumi; Higaki, Shogo; Hirota, Masahiro; Akita, Kae; Hasezawa, Seiichiro

    2012-01-01

    In response to contamination from the recent Fukushima nuclear accident, we conducted radionuclide analysis on bamboos sampled from six sites within a 25 to 980 km radius of the Fukushima Daiichi nuclear power plant. Maximum activity concentrations of radiocesium 134Cs and 137Cs in samples from Fukushima city, 65 km away from the Fukushima Daiichi plant, were in excess of 71 and 79 kBq/kg, dry weight (DW), respectively. In Kashiwa city, 195 km away from the Fukushima Daiichi, the sample concentrations were in excess of 3.4 and 4.3 kBq/kg DW, respectively. In Toyohashi city, 440 km away from the Fukushima Daiichi, the concentrations were below the measurable limits of up to 4.5 Bq/kg DW. In the radiocesium contaminated samples, the radiocesium activity was higher in mature and fallen leaves than in young leaves, branches and culms. PMID:22496858

  4. Seismological analysis of the fourth North Korean nuclear test

    NASA Astrophysics Data System (ADS)

    Hartmann, Gernot; Gestermann, Nicolai; Ceranna, Lars

    2016-04-01

    The Democratic People's Republic of Korea has conducted its fourth underground nuclear explosions on 06.01.2016 at 01:30 (UTC). The explosion was clearly detected and located by the seismic network of the International Monitoring System (IMS) of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Additional seismic stations of international earthquake monitoring networks at regional distances, which are not part of the IMS, are used to precisely estimate the epicenter of the event in the North Hamgyong province (41.38°N / 129.05°E). It is located in the area of the North Korean Punggye-ri nuclear test site, where the verified nuclear tests from 2006, 2009, and 2013 were conducted as well. The analysis of the recorded seismic signals provides the evidence, that the event was originated by an explosive source. The amplitudes as well as the spectral characteristics of the signals were examined. Furthermore, the similarity of the signals with those from the three former nuclear tests suggests very similar source type. The seismograms at the 8,200 km distant IMS station GERES in Germany, for example, show the same P phase signal for all four explosions, differing in the amplitude only. The comparison of the measured amplitudes results in the increasing magnitude with the chronology of the explosions from 2006 (mb 4.2), 2009 (mb 4.8) until 2013 (mb 5.1), whereas the explosion in 2016 had approximately the same magnitude as that one three years before. Derived from the magnitude, a yield of 14 kt TNT equivalents was estimated for both explosions in 2013 and 2016; in 2006 and 2009 yields were 0.7 kt and 5.4 kt, respectively. However, a large inherent uncertainty for these values has to be taken into account. The estimation of the absolute yield of the explosions depends very much on the local geological situation and the degree of decoupling of the explosive from the surrounding rock. Due to the missing corresponding information, reliable magnitude-yield estimation for the

  5. Seasonal-Resolution δ18O in Speleothems by Ion Microprobe: Revealing Asian Monsoon Dynamics

    NASA Astrophysics Data System (ADS)

    Orland, I. J.; Edwards, R. L.; Cheng, H.; Kozdon, R.; Valley, J. W.

    2014-12-01

    Over the last decade, ion microprobe analysis of speleothems (cave carbonates) has increased the temporal resolution of their oxygen isotope (δ18O) paleoclimate proxy records. Recent improvements in methodology, standardization, and imaging at the WiscSIMS lab make it possible to examine sub-annual patterns of δ18O variability at 10-µm-scale, revealing new seasonal paleoenvironmental information. We applied this technique to an important suite of Chinese stalagmites with conventional drill-sampled δ18O records that reflect changes in Asian Monsoon dynamics across the last deglaciation. Seasonal-resolution δ18O analyses in the Chinese stalagmites reveal regular patterns of annual δ18O variability. Quantitative assessment of the patterns identifies two important components in the δ18O records. First, the source and rainout histories of water vapors that ultimately yield rainfall over China play a primary role in determining the δ18O value of speleothem calcite year-round. Second, intra-annual patterns of calcite δ18O variability indicate that the annual proportion of monsoon precipitation changes systematically during the last deglaciation; the annual proportion of monsoon rainfall is greater during the Holocene and Bølling-Allerød than during the Younger Dryas. This is the first time these components have been characterized in any speleothem δ18O record of monsoon dynamics because seasonal δ18O variability is lost by conventional drill-sampling. Ion microprobe analysis of speleothems can also produce year-by-year records of δ18O across abrupt climate change events. At the Younger Dryas-Holocene transition in a Kulishu Cave stalagmite, which spanned 16 years at 11.53 ky BP, there is a relatively smooth decrease in year-round δ18O(calcite). In contrast, the intra-annual δ18O patterns indicate that the increase in the annual proportion of monsoon rainfall across this transition is stochastic, implying that this record can distinguish the regional

  6. Thorite in an Apollo 12 granite fragment and age determination using the electron microprobe

    NASA Astrophysics Data System (ADS)

    Seddio, Stephen M.; Jolliff, Bradley L.; Korotev, Randy L.; Carpenter, Paul K.

    2014-06-01

    We present the first quantitative compositional analysis of thorite in a lunar sample. The sample, a granitic assemblage, also contains monazite and yttrobetafite grains, all with concentrations of U, Th, and Pb sufficiently high to determine reliably with the electron microprobe. The assemblage represents the first documented occurrence of these three minerals together and only the second reported occurrence of thorite in a lunar rock. Sample 12023,147-10 is a small, monomict rock fragment recovered from an Apollo 12 regolith sample. It comprises graphic intergrowths of K-feldspar and quartz, and plagioclase and quartz, along with minor or accessory hedenbergite, fayalite, ilmenite, zircon, yttrobetafite, thorite, monazite, and Fe metal. Thorite, ideally ThSiO4, occurs in the assemblage adjacent to quartz and plagioclase, and includes a 12% xenotime ([Y,HREE]PO4) component. From quantitative electron-probe microanalysis (EPMA) of Th, U, and Pb in thorite, assuming that all of the measured Pb is radiogenic, we calculate an age of 3.87 ± 0.03 Ga. Yttrobetafite and monazite, which contain lesser concentrations of U, Th, and Pb than the thorite, yield ages of 3.78 ± 0.06 Ga and 3.9 ± 0.3 Ga, respectively. These dates are consistent with formation of the granitic material around 3.8-3.9 Ga, possibly associated with, or after, the formation of the Imbrium basin. This age falls within a group of younger ages for granitic samples, measured mainly by ion microprobe analysis of zircon, compared to a suite of older ages, ca. 4.20-4.32 Ga, also from zircons (Meyer et al., 1996). A 3.8-3.9 Ga age may reflect an origin following the Imbrium event whereby granitic melt formed as a result of heating and melting, and was mobilized and emplaced along an Imbrium-related ring-fracture system. Silicic volcanic or exposed intrusive materials occur in several circum-Imbrium locations such as the Mairan and Gruithuisen Domes and in ejecta excavated by Aristarchus crater. Perhaps

  7. Age Dating from Electron Microprobe Analyses of U, Th, and Pb: Geological Advantages and Analytical Difficulties.

    PubMed

    Bowles, John F W

    2015-10-01

    Electron microprobe analysis of U, Th, and Pb in naturally occurring minerals can indicate their age. Where the Pb is entirely due to the radioactive decay of U and Th, the time since mineral formation or equilibration can be calculated. Uraninite (UO2), monazite (REE PO4), zircon (ZrSiO4), and xenotime (YPO4) have been used, the latter containing U and/or Th in minor proportions. Any stable U- or Th-bearing phase can be considered. Careful analysis is required with attention to interferences, background measurement, detection limits, and Pb-free sample preparation. Extended counting times (600 s) at a probe current >200 nA are recommended. Ages can be determined from uraninite older than 2 Ma for a Pb detection limit of 0.02% and up to 700-1,000 Ma, after which Pb can be lost from the structure. The youngest monazite ages permitted by the Pb detection limit are 50-100 Ma and ages greater than 3,000 Ma have been determined. The method does not provide the detail of isotopic methods, but results can be obtained more readily. Examples show dating of cheralite ((Ca,Ce)(Th,Ce)(PO4)2), a rock containing primary and secondary UO2, and a suite of detrital uraninite grains that formed a part of a mineral exploration program. PMID:25936439

  8. Measuring localized viscoelasticity of the vitreous body using intraocular microprobes.

    PubMed

    Pokki, Juho; Ergeneman, Olgaç; Sevim, Semih; Enzmann, Volker; Torun, Hamdi; Nelson, Bradley J

    2015-10-01

    Vitrectomy is a standard ophthalmic procedure to remove the vitreous body from the eye. The biomechanics of the vitreous affects its duration (by changing the removal rate) and the mechanical forces transmitted via the vitreous on the surrounding tissues during the procedure. Biomechanical characterization of the vitreous is essential for optimizing the design and control of instruments that operate within the vitreous for improved precision, safety, and efficacy. The measurements are carried out using a magnetic microprobe inserted into the vitreous, a method known as magnetic microrheology. The location of the probe is tracked by a microscope/camera while magnetic forces are exerted wirelessly by applied magnetic fields. In this work, in vitro artificial vitreous, ex vivo human vitreous and ex vivo porcine vitreous were characterized. In addition, in vivo rabbit measurements were performed using a suturelessly injected probe. Measurements indicate that viscoelasticity parameters of the ex vivo human vitreous are an order of magnitude different from those of the ex vivo porcine vitreous. The in vivo intra-operative measurements show typical viscoelastic behavior of the vitreous with a lower compliance than the ex vivo measurements. The results of the magnetic microrheology measurements were validated with those obtained by a standard atomic force microscopy (AFM) method and in vitro artificial vitreous. This method allows minimally-invasive characterization of localized mechanical properties of the vitreous in vitro, ex vivo, and in vivo. A better understanding of the characteristics of the vitreous can lead to improvements in treatments concerning vitreal manipulation such as vitrectomy. PMID:26238733

  9. Graph-Based Analysis of Nuclear Smuggling Data

    SciTech Connect

    Cook, Diane; Holder, Larry; Thompson, Sandra E.; Whitney, Paul D.; Chilton, Lawrence

    2009-12-01

    Much of the data that is collected and analyzed today is structural, consisting not only of entities but also of relationships between the entities. As a result, analysis applications rely upon automated structural data mining approaches to find patterns and concepts of interest. This ability to analyze structural data has become a particular challenge in many security-related domains. In these domains, focusing on the relationships between entities in the data is critical to detect important underlying patterns. In this study we apply structural data mining techniques to automate analysis of nuclear smuggling data. In particular, we choose to model the data as a graph and use graph-based relational learning to identify patterns and concepts of interest in the data. In this paper, we identify the analysis questions that are of importance to security analysts and describe the knowledge representation and data mining approach that we adopt for this challenge. We analyze the results using the Russian nuclear smuggling event database.

  10. Solid Phase Microextraction for the Analysis of Nuclear Weapons

    SciTech Connect

    Chambers, D M

    2001-06-01

    This document is a compendium of answers to commonly asked questions about solid phase microextraction as it relates to the analysis of nuclear weapons. We have also included a glossary of terms associated with this analytical method as well as pertinent weapons engineering terminology. Microextraction is a new collection technique being developed to nonintrusively sample chemicals from weapon headspace gases for subsequent analysis. The chemicals that are being targeted outgas from the high explosives and other organic materials used in the weapon assembly. This technique is therefore a valuable tool to: (1) remotely detect and assess the aging of Lawrence Livermore National Laboratory (LLNL) and, in some cases, Sandia National Laboratory (SNL) organic materials; and (2) identify potential compatibility issues (i.e., materials interactions) that should be more carefully monitored during surveillance tear-downs. Microextraction is particularly attractive because of the practical constraints inherent to the weapon surveillance procedure. To remain transparent to other core surveillance activities and fall within nuclear safety guidelines, headspace analysis of the weapons requires a procedure that: (1) maintains ambient temperature conditions; (2) allows practical collection times of less than 20 min; (3) maintains the integrity of the weapon gas volume; (4) provides reproducible and quantitative results; and (5) can identify all possible targets.

  11. Rare earth element measurements and mapping of minerals in the Allende CAI, 7R19-1, by NanoSIMS ion microprobe

    NASA Astrophysics Data System (ADS)

    Ito, Motoo; Messenger, Scott

    2016-04-01

    We have established analytical procedures for quantitative rare earth element (REE) measurements by NanoSIMS 50L ion microprobe with 2-10 μm spatial resolution. Measurements are performed by multidetection using energy filtering under several static magnetic field settings. Relative sensitivity factors and REE oxide/REE element secondary ion ratios that we determined for the NanoSIMS match values previously determined for other ion microprobes. REE measurements of 100 ppm REE glass standards yielded reproducibility and accuracy of 0.5-2.5% and 5-15%, respectively. REE measurements of minerals of an Allende type-A CAI, 7R19-1, were performed using three different methods: spot analysis, line profile, and imaging. These data are in excellent agreement with previous REE measurements of this inclusion by IMS-3f ion microprobe. The higher spatial resolution NanoSIMS measurements provide additional insight into the formation process of this CAI and offer a promising new tool for analysis of fine-grained and complexly zoned materials.

  12. High-Resolution X-ray Microprobe Using a Spatial Filter and Its Application to Micro-XAFS Measurements

    SciTech Connect

    Terada, Y.; Tanida, H.; Uruga, T.; Takeuchi, A.; Suzuki, Y.; Goto, S.

    2011-09-09

    An x-ray microprobe system with total-reflection mirror optics for trace element analysis has been developed at beamline 37XU of SPring-8. To achieve sub-microprobe, a spatial filter has been installed downstream of a monochromator. Focusing tests have been performed in the x-ray energy range of 6-14 keV. A focused beam size of 0.83 {mu}m(V)x1.35 {mu}m(H) has been obtained at an x-ray energy of 10 keV, and using a spatial filter in the horizontal direction, the beam size is down to 0.84 {mu}m. Micro-x-ray absorption fine structure (XAFS) spectroscopy of submicrometer particles has been done by utilizing the total-reflection mirror optics. It was clearly observed from the nickel K-edge XAFS spectra that the oxidation state of nickel was a mixture of metal and oxide even in the single submicrometer particle.

  13. Computational neutronic analysis of the nuclear vapor thermal rocket engine

    SciTech Connect

    Dugan, E.T.; Watanabe, Y.; Kuras, S.; Maya, I.; Diaz, N.J. )

    1992-01-01

    Calculational procedures and results are presented for the neutronic analysis of the Nuclear Vapor Thermal Reactor (NVTR) rocket engine. The NVTR, in a rocket engine, uses modified NERVA geometry and systems with the solid fuel replaced by highly enriched (>85%) uranium tetrafluoride (UF[sub 4]) vapor. In the NVTR, the hydrogen propellant is the primary coolant, is physically separated from the UF[sub 4] vapor (which is not circulated), is maintained at high pressure (50 to 100 atm), and exits the core at 3100 to 3500 K.

  14. In situ structural analysis of the human nuclear pore complex.

    PubMed

    von Appen, Alexander; Kosinski, Jan; Sparks, Lenore; Ori, Alessandro; DiGuilio, Amanda L; Vollmer, Benjamin; Mackmull, Marie-Therese; Banterle, Niccolo; Parca, Luca; Kastritis, Panagiotis; Buczak, Katarzyna; Mosalaganti, Shyamal; Hagen, Wim; Andres-Pons, Amparo; Lemke, Edward A; Bork, Peer; Antonin, Wolfram; Glavy, Joseph S; Bui, Khanh Huy; Beck, Martin

    2015-10-01

    Nuclear pore complexes are fundamental components of all eukaryotic cells that mediate nucleocytoplasmic exchange. Determining their 110-megadalton structure imposes a formidable challenge and requires in situ structural biology approaches. Of approximately 30 nucleoporins (Nups), 15 are structured and form the Y and inner-ring complexes. These two major scaffolding modules assemble in multiple copies into an eight-fold rotationally symmetric structure that fuses the inner and outer nuclear membranes to form a central channel of ~60 nm in diameter. The scaffold is decorated with transport-channel Nups that often contain phenylalanine-repeat sequences and mediate the interaction with cargo complexes. Although the architectural arrangement of parts of the Y complex has been elucidated, it is unclear how exactly it oligomerizes in situ. Here we combine cryo-electron tomography with mass spectrometry, biochemical analysis, perturbation experiments and structural modelling to generate, to our knowledge, the most comprehensive architectural model of the human nuclear pore complex to date. Our data suggest previously unknown protein interfaces across Y complexes and to inner-ring complex members. We show that the transport-channel Nup358 (also known as Ranbp2) has a previously unanticipated role in Y-complex oligomerization. Our findings blur the established boundaries between scaffold and transport-channel Nups. We conclude that, similar to coated vesicles, several copies of the same structural building block--although compositionally identical--engage in different local sets of interactions and conformations. PMID:26416747

  15. Risk analysis of nuclear safeguards regulations. [Aggregated Systems Model (ASM)

    SciTech Connect

    Al-Ayat, R.A.; Altman, W.D.; Judd, B.R.

    1982-06-01

    The Aggregated Systems Model (ASM), a probabilisitic risk analysis tool for nuclear safeguards, was applied to determine benefits and costs of proposed amendments to NRC regulations governing nuclear material control and accounting systems. The objective of the amendments was to improve the ability to detect insiders attempting to steal large quantities of special nuclear material (SNM). Insider threats range from likely events with minor consequences to unlikely events with catastrophic consequences. Moreover, establishing safeguards regulations is complicated by uncertainties in threats, safeguards performance, and consequences, and by the subjective judgments and difficult trade-offs between risks and safeguards costs. The ASM systematically incorporates these factors in a comprehensive, analytical framework. The ASM was used to evaluate the effectiveness of current safeguards and to quantify the risk of SNM theft. Various modifications designed to meet the objectives of the proposed amendments to reduce that risk were analyzed. Safeguards effectiveness was judged in terms of the probability of detecting and preventing theft, the expected time to detection, and the expected quantity of SNM diverted in a year. Data were gathered in tours and interviews at NRC-licensed facilities. The assessment at each facility was begun by carefully selecting scenarios representing the range of potential insider threats. A team of analysts and facility managers assigned probabilities for detection and prevention events in each scenario. Using the ASM we computed the measures of system effectiveness and identified cost-effective safeguards modifications that met the objectives of the proposed amendments.

  16. Mathematical analysis of compressive/tensile molecular and nuclear structures

    NASA Astrophysics Data System (ADS)

    Wang, Dayu

    Mathematical analysis in chemistry is a fascinating and critical tool to explain experimental observations. In this dissertation, mathematical methods to present chemical bonding and other structures for many-particle systems are discussed at different levels (molecular, atomic, and nuclear). First, the tetrahedral geometry of single, double, or triple carbon-carbon bonds gives an unsatisfying demonstration of bond lengths, compared to experimental trends. To correct this, Platonic solids and Archimedean solids were evaluated as atoms in covalent carbon or nitrogen bond systems in order to find the best solids for geometric fitting. Pentagonal solids, e.g. the dodecahedron and icosidodecahedron, give the best fit with experimental bond lengths; an ideal pyramidal solid which models covalent bonds was also generated. Second, the macroscopic compression/tension architectural approach was applied to forces at the molecular level, considering atomic interactions as compressive (repulsive) and tensile (attractive) forces. Two particle interactions were considered, followed by a model of the dihydrogen molecule (H2; two protons and two electrons). Dihydrogen was evaluated as two different types of compression/tension structures: a coaxial spring model and a ring model. Using similar methods, covalent diatomic molecules (made up of C, N, O, or F) were evaluated. Finally, the compression/tension model was extended to the nuclear level, based on the observation that nuclei with certain numbers of protons/neutrons (magic numbers) have extra stability compared to other nucleon ratios. A hollow spherical model was developed that combines elements of the classic nuclear shell model and liquid drop model. Nuclear structure and the trend of the "island of stability" for the current and extended periodic table were studied.

  17. Human Factors Considerations in New Nuclear Power Plants: Detailed Analysis.

    SciTech Connect

    OHara,J.; Higgins, J.; Brown, W.; Fink, R.

    2008-02-14

    This Nuclear Regulatory Commission (NRC) sponsored study has identified human-performance issues in new and advanced nuclear power plants. To identify the issues, current industry developments and trends were evaluated in the areas of reactor technology, instrumentation and control technology, human-system integration technology, and human factors engineering (HFE) methods and tools. The issues were organized into seven high-level HFE topic areas: Role of Personnel and Automation, Staffing and Training, Normal Operations Management, Disturbance and Emergency Management, Maintenance and Change Management, Plant Design and Construction, and HFE Methods and Tools. The issues where then prioritized into four categories using a 'Phenomena Identification and Ranking Table' methodology based on evaluations provided by 14 independent subject matter experts. The subject matter experts were knowledgeable in a variety of disciplines. Vendors, utilities, research organizations and regulators all participated. Twenty issues were categorized into the top priority category. This Brookhaven National Laboratory (BNL) technical report provides the detailed methodology, issue analysis, and results. A summary of the results of this study can be found in NUREG/CR-6947. The research performed for this project has identified a large number of human-performance issues for new control stations and new nuclear power plant designs. The information gathered in this project can serve as input to the development of a long-term strategy and plan for addressing human performance in these areas through regulatory research. Addressing human-performance issues will provide the technical basis from which regulatory review guidance can be developed to meet these challenges. The availability of this review guidance will help set clear expectations for how the NRC staff will evaluate new designs, reduce regulatory uncertainty, and provide a well-defined path to new nuclear power plant licensing.

  18. Characterization of Nuclear Fuel using Multivariate Statistical Analysis

    SciTech Connect

    Robel, M; Robel, M; Robel, M; Kristo, M J; Kristo, M J

    2007-11-27

    Various combinations of reactor type and fuel composition have been characterized using principle components analysis (PCA) of the concentrations of 9 U and Pu isotopes in the 10 fuel as a function of burnup. The use of PCA allows the reduction of the 9-dimensional data (isotopic concentrations) into a 3-dimensional approximation, giving a visual representation of the changes in nuclear fuel composition with burnup. Real-world variation in the concentrations of {sup 234}U and {sup 236}U in the fresh (unirradiated) fuel was accounted for. The effects of reprocessing were also simulated. The results suggest that, 15 even after reprocessing, Pu isotopes can be used to determine both the type of reactor and the initial fuel composition with good discrimination. Finally, partial least squares discriminant analysis (PSLDA) was investigated as a substitute for PCA. Our results suggest that PLSDA is a better tool for this application where separation between known classes is most important.

  19. Analysis of fine structure in the nuclear continuum

    SciTech Connect

    Shevchenko, A.; Kalmykov, Y.; Neumann-Cosel, P. von; Ponomarev, V. Yu.; Richter, A.; Wambach, J.; Carter, J.; Usman, I.; Cooper, G. R. J.; Fearick, R. W.

    2008-02-15

    Fine structure has been shown to be a general phenomenon of nuclear giant resonances of different multipolarities over a wide mass range. In this article we assess various techniques that have been proposed to extract quantitative information from the fine structure in terms of characteristic scales. These include the so-called local scaling dimension, the entropy index method, Fourier analysis, and continuous and discrete wavelet transforms. As an example, results on the isoscalar giant quadrupole resonance in {sup 208}Pb from high-energy-resolution inelastic proton scattering and calculations with the quasiparticle-phonon model are analyzed. Wavelet analysis, both continuous and discrete, of the spectra is shown to be a powerful tool to extract the magnitude and localization of characteristic scales.

  20. Chloroplast and nuclear microsatellite analysis of Aegilops cylindrica.

    PubMed

    Gandhi, Harish T; Vales, M Isabel; Watson, Christy J W; Mallory-Smith, Carol A; Mori, Naoki; Rehman, Maqsood; Zemetra, Robert S; Riera-Lizarazu, Oscar

    2005-08-01

    Aegilops cylindrica Host (2n = 4x = 28, genome CCDD) is an allotetraploid formed by hybridization between the diploid species Ae. tauschii Coss. (2n = 2x = 14, genome DD) and Ae. markgrafii (Greuter) Hammer (2n = 2x = 14, genome CC). Previous research has shown that Ae. tauschii contributed its cytoplasm to Ae. cylindrica. However, our analysis with chloroplast microsatellite markers showed that 1 of the 36 Ae. cylindrica accessions studied, TK 116 (PI 486249), had a plastome derived from Ae. markgrafii rather than Ae. tauschii. Thus, Ae. markgrafii has also contributed its cytoplasm to Ae. cylindrica. Our analysis of chloroplast and nuclear microsatellite markers also suggests that D-type plastome and the D genome in Ae. cylindrica were closely related to, and were probably derived from, the tauschii gene pool of Ae. tauschii. A determination of the likely source of the C genome and the C-type plastome in Ae. cylindrica was not possible. PMID:15986256

  1. An Analysis of Nuclear-Rocket Nozzle Cooling

    NASA Technical Reports Server (NTRS)

    Robbins, William H.; Bachkin, Daniel; Medeiros, Arthur A.

    1960-01-01

    A nuclear-rocket regenerative-cooling analysis was conducted over a range of reactor power of 46 to 1600 megawatts and is summarized herein. Although the propellant (hydrogen) is characterized by a large heat-sink capacity, an analysis of the local heat-flux capability of the coolant at the nozzle throat indicated that, for conventional values of system pressure drop, the cooling capability was inadequate to maintain a selected wall temperature of 1440 R. Several techniques for improving the cooling capability were discussed, for example, high pressure drop, high wall temperature, refractory wall coatings, thin highly conductive walls, and film cooling. In any specific design a combination of methods will probably be utilized to achieve successful cooling.

  2. Turbopump Design and Analysis Approach for Nuclear Thermal Rockets

    SciTech Connect

    Chen, Shucheng S.; Veres, Joseph P.; Fittje, James E.

    2006-01-20

    A rocket propulsion system, whether it is a chemical rocket or a nuclear thermal rocket, is fairly complex in detail but rather simple in principle. Among all the interacting parts, three components stand out: they are pumps and turbines (turbopumps), and the thrust chamber. To obtain an understanding of the overall rocket propulsion system characteristics, one starts from analyzing the interactions among these three components. It is therefore of utmost importance to be able to satisfactorily characterize the turbopump, level by level, at all phases of a vehicle design cycle. Here at the NASA Glenn Research Center, as the starting phase of a rocket engine design, specifically a Nuclear Thermal Rocket Engine design, we adopted the approach of using a high level system cycle analysis code (NESS) to obtain an initial analysis of the operational characteristics of a turbopump required in the propulsion system. A set of turbopump design codes (PumpDes and TurbDes) were then executed to obtain sizing and performance parameters of the turbopump that were consistent with the mission requirements. A set of turbopump analyses codes (PUMPA and TURBA) were applied to obtain the full performance map for each of the turbopump components; a two dimensional layout of the turbopump based on these mean line analyses was also generated. Adequacy of the turbopump conceptual design will later be determined by further analyses and evaluation. In this paper, descriptions and discussions of the aforementioned approach are provided and future outlooks are discussed.

  3. Challenges in structural analysis for deformed nuclear reactivity assessments.

    SciTech Connect

    Tallman, Tyler N.; Smith, Jeffrey A.; Villa, Daniel L.

    2010-09-01

    Launch safety calculations for past space reactor concepts have usually been limited to immersion of the reactor in water and/or sand, using nominal system geometries or in some cases simplified compaction scenarios. Deformation of the reactor core by impact during the accident sequence typically has not been considered because of the complexity of the calculation. Recent advances in codes and computing power have made such calculations feasible. The accuracy of such calculations depends primarily on the underlying structural analysis. Even though explicit structural dynamics is a mature field, nuclear reactors present significant challenges to obtain accurate deformation predictions. The presence of a working fluid is one of the primary contributors to challenges in these predictions. The fluid-structure interaction cannot be neglected because the fluid surrounds the nuclear fuel which is the most important region in the analysis. A detailed model of a small eighty-five pin reactor was built with the working fluid modeled as smoothed particle hydrodynamic (SPH) elements. Filling the complex volume covered by the working fluid with SPH elements required development of an algorithm which eliminates overlaps between hexahedral and SPH elements. The results with and without the working fluid were found to be considerably different with respect to reactivity predictions.

  4. Multi-Detector Analysis System for Spent Nuclear Fuel Characterization

    SciTech Connect

    Reber, Edward Lawrence; Aryaeinejad, Rahmat; Cole, Jerald Donald; Drigert, Mark William; Jewell, James Keith; Egger, Ann Elizabeth; Cordes, Gail Adele

    1999-09-01

    The Spent Nuclear Fuel (SNF) Non-Destructive Analysis (NDA) program at INEEL is developing a system to characterize SNF for fissile mass, radiation source term, and fissile isotopic content. The system is based on the integration of the Fission Assay Tomography System (FATS) and the Gamma-Neutron Analysis Technique (GNAT) developed under programs supported by the DOE Office of Non-proliferation and National Security. Both FATS and GNAT were developed as separate systems to provide information on the location of special nuclear material in weapons configuration (FATS role), and to measure isotopic ratios of fissile material to determine if the material was from a weapon (GNAT role). FATS is capable of not only determining the presence and location of fissile material but also the quantity of fissile material present to within 50%. GNAT determines the ratios of the fissile and fissionable material by coincidence methods that allow the two prompt (immediately) produced fission fragments to be identified. Therefore, from the combination of FATS and GNAT, MDAS is able to measure the fissile material, radiation source term, and fissile isotopics content.

  5. System Analysis of Nuclear-Assisted Syngas Production from Coal

    SciTech Connect

    E. A. Harvego; M. G. McKellar; J. E. O'Brien

    2009-07-01

    A system analysis has been performed to assess the efficiency and carbon utilization of a nuclear-assisted coal gasification process. The nuclear reactor is a high-temperature helium-cooled reactor that is used primarily to provide power for hydrogen production via hightemperature electrolysis. The supplemental hydrogen is mixed with the outlet stream from an oxygen-blown coal gasifier to produce a hydrogen-rich gas mixture, allowing most of the carbon dioxide to be converted into carbon monoxide, with enough excess hydrogen to produce a syngas product stream with a hydrogen/carbon monoxide molar ratio of about 2:1. Oxygen for the gasifier is also provided by the high-temperature electrolysis process. Results of the analysis predict 90.5% carbon utilization with a syngas production efficiency (defined as the ratio of the heating value of the produced syngas to the sum of the heating value of the coal plus the high-temperature reactor heat input) of 64.4% at a gasifier temperature of 1866 K for the high-moisture-content lignite coal considered. Usage of lower moisture coals such as bituminous can yield carbon utilization approaching 100% and 70% syngas production efficiency.

  6. Turbopump Design and Analysis Approach for Nuclear Thermal Rockets

    NASA Technical Reports Server (NTRS)

    Chen, Shu-cheng S.; Veres, Joseph P.; Fittje, James E.

    2006-01-01

    A rocket propulsion system, whether it is a chemical rocket or a nuclear thermal rocket, is fairly complex in detail but rather simple in principle. Among all the interacting parts, three components stand out: they are pumps and turbines (turbopumps), and the thrust chamber. To obtain an understanding of the overall rocket propulsion system characteristics, one starts from analyzing the interactions among these three components. It is therefore of utmost importance to be able to satisfactorily characterize the turbopump, level by level, at all phases of a vehicle design cycle. Here at NASA Glenn Research Center, as the starting phase of a rocket engine design, specifically a Nuclear Thermal Rocket Engine design, we adopted the approach of using a high level system cycle analysis code (NESS) to obtain an initial analysis of the operational characteristics of a turbopump required in the propulsion system. A set of turbopump design codes (PumpDes and TurbDes) were then executed to obtain sizing and performance characteristics of the turbopump that were consistent with the mission requirements. A set of turbopump analyses codes (PUMPA and TURBA) were applied to obtain the full performance map for each of the turbopump components; a two dimensional layout of the turbopump based on these mean line analyses was also generated. Adequacy of the turbopump conceptual design will later be determined by further analyses and evaluation. In this paper, descriptions and discussions of the aforementioned approach are provided and future outlooks are discussed.

  7. SYSTEM ANALYSIS OF NUCLEAR-ASSISTED SYNGAS PRODUCTION FROM COAL

    SciTech Connect

    E. A. Harvego; M. G. McKellar; J. E. O'Brien

    2008-09-01

    A system analysis has been performed to assess the efficiency and carbon utilization of a nuclear-assisted coal gasification process. The nuclear reactor is a high-temperature helium-cooled reactor that is used primarily to provide power for hydrogen production via high-temperature electrolysis. The supplemental hydrogen is mixed with the outlet stream from an oxygen-blown coal gasifier to produce a hydrogen-rich gas mixture, allowing most of the carbon dioxide to be converted into carbon monoxide, with enough excess hydrogen to produce a syngas product stream with a hydrogen/carbon monoxide molar ratio of about 2:1. Oxygen for the gasifier is also provided by the high-temperature electrolysis process. Results of the analysis predict 90.5% carbon utilization with a syngas production efficiency (defined as the ratio of the heating value of the produced syngas to the sum of the heating value of the coal plus the high-temperature reactor heat input) of 66.1% at a gasifier temperature of 1866 K for the high-moisture-content lignite coal considered. Usage of lower moisture coals such as bituminous can yield carbon utilization approaching 100% and 70% syngas production efficiency.

  8. Investigation of elemental distribution in human femoral head by PIXE and SRXRF microprobe

    NASA Astrophysics Data System (ADS)

    Zhang, Y. X.; Wang, Y. S.; Zhang, Y. P.; Zhang, G. L.; Huang, Y. Y.; He, W.

    2007-07-01

    In order to study the distribution and possible degenerative processes inducing the loss of inorganic substances in bone and to provide a scientific basis for the prevention and therapy of osteoporosis, proton induced X-ray emission (PIXE) method is used for the determination of elemental concentrations in femoral heads from five autopsies and seven patients with femoral neck fractures. Synchrotron radiation X-ray fluorescence (SRXRF) microprobe analysis technique is used to scan a slice of the femoral head from its periphery to its center, via cartilage, compact and spongy zones. The specimen preparation and experiment procedure are described in detail. The results show that the concentrations of P, Ca, Fe, Cu, Sr in the control group are higher than those in the patient group, but the concentrations of S, K, Zn, Mn are not significantly different. The quantitative results of elemental distribution, such as Ca, P, K, Fe, Zn, Sr and Pb in bone slice tissue including cartilage, substantial compact and substantial spongy, are investigated. The data obtained show that the concentrations of Ca, P, K, (the major elements of bone composition), are obviously low in both spongy and cartilage zones in the patient group, but there are no remarkable differences in the compact zone. Combined with the correlations between P, K, Zn, Sr and Ca, the loss mechanism of minerals and the physiological functions of some metal elements in bone are also discussed.

  9. Ion microprobe elemental analyses of impact features on interplanetary dust experiment sensor surfaces

    NASA Technical Reports Server (NTRS)

    Hunter, Jerry L.; Wortman, Jim J.; Griffis, Dieter P.; Simon, Charles G.

    1991-01-01

    Hypervelocity impact features on several of the electro-active dust sensors utilized in the Interplanetary Dust Experiment (IDE) were subjected to elemental analysis using an ion microprobe. The negatively biased dust sensor surfaces acted as ion traps for cations produced in the plasma plumes of impacting particles. Impactor residue surrounds most impact features to two or three feature diameters. After etching away a layer of carbonaceous/silicaceous surface contamination, low mass resolution elemental survey scans are used to tentatively identify the presence of impactor debris. High mass resolution two-dimensional elemental maps and three dimensional depth profiling of the feature and surrounding area show the distribution and relative composition of the debris. The location of these sensors on the six primary Long Duration Exposure Facility (LDEF) sides provides a unique opportunity to further define the debris environment. Researchers applied the same techniques to impact and contaminant features on a set of ultra-pure, highly polished single crystal germanium wafer witness plates that were mounted on row 12 and exposed to the environment during the entire mission.

  10. Development of a bio-PIXE setup at the Debrecen scanning proton microprobe

    NASA Astrophysics Data System (ADS)

    Kertész, Zs.; Szikszai, Z.; Uzonyi, I.; Simon, A.; Kiss, Á. Z.

    2005-04-01

    On the growing need of an accurate, quantitative method for the analysis of thin biological tissues down to the cell level, a measurement setup and data evaluating system has been developed at the Debrecen scanning proton microprobe facility, using its unique capability of the PIXE-PIXE technique. Quantitative elemental concentrations and true elemental maps from C to U can be produced in the case of thin (10-50 μm), inhomogeneous samples of organic matrix with a 2 μm lateral resolution. The method is based on the combined application of on-axis STIM and PIXE-PIXE ion beam analytical techniques. STIM spectra and maps are used to determine the morphology and the area density of the samples. PIXE spectra and maps of an ultra thin windowed and a conventional Be-windowed Si(Li) X-ray detectors are used to quantify concentrations and distributions of elements in the C to Fe (light and medium) and S to U (medium and heavy) atomic number regions, separately. For cross-checking the validation of the obtained data in a few cases RBS technique was used simultaneously. The application of the new bio-PIXE method is shown through an example, the study of the penetration and clearance of ultra-fine particles containing heavy metals (TiO2) of physical bodycare cosmetics in different layers of skin within the frame of the NANODERM EU5 project.

  11. In vivo chemical investigation of human skin using a confocal Raman fiber optic microprobe.

    PubMed

    Chrit, L; Hadjur, C; Morel, S; Sockalingum, G; Lebourdon, G; Leroy, F; Manfait, M

    2005-01-01

    To evaluate the potential of a new in vivo confocal Raman microprobe, we undertake a pilot study in human skin. A fiber optic probe is operated with a 633-nm laser and trials are conducted in healthy volunteers. We examine changes in molecular composition and structure of the stratum corneum, from different volunteers, from different anatomical sites and skin layers. Main spectral variations are detected in the following regions: 800 to 900 cm(-1) (amino acids); 1200 to 1290 cm(-1) (proteins); and 1030 to 1130 cm(-1), 1300 to 1450 cm(-1), and 2800 to 2900 cm(-1) (lipids). Curve fitting of the amide 1 region performs in detail protein secondary structural variations of the amide 1 band. Protein conformation is also found to vary depending on the anatomical site and volunteer. Similar analysis of the 730- to 1170-cm(-1) spectral window reveals a different organization of lamellar lipids: gel for forearm and palm, and liquid-crystalline phase for fingertips. All these variations result from changes in the stratum corneum components such as natural moisturizing factor (NMF), lipids (namely ceramides), and water. Hierarchical clustering classification is also performed to sort out Raman data obtained from different subjects. Further improvement of the confocal probe would be to adapt a 360-deg configuration enabling access to other anatomical sites. PMID:16178641

  12. Development of a High Resolution-High Sensitivity Ion Microprobe Facility for Cosmochemical Applications

    NASA Technical Reports Server (NTRS)

    McKeegan, Kevin D.

    1998-01-01

    NASA NAGW-4112 has supported development of the CAMECA ims 1270 ion microprobe at UCLA for applications in cosmochemistry. The instrument has been brought to an operational status and techniques developed for accurate, precise microbeam analysis of oxygen isotope ratios in polished thin-sections. We made the first oxygen isotopic (delta(18)O and delta(17)O) measurements of rare mafic silicates in the most chemically primitive meteorites, the a chondrites (Leshin et al., 1997). The results have implications for both high temperature processing in the nebula and low-T aqueous alteration on the CI asteroid. We have performed measurements of oxygen isotopic compositions of magnetite and co-existing olivine from carbonaceous (Choi et al., 1997) and unequilibrated ordinary chondrites (Choi et al., in press). This work has identified a significant new oxygen isotope reservoir in the early solar system: water characterized by a very high Delta(17)) value of approx. 5 % per thousand. We have determined the spatial distributions of oxygen isotopic anomalies in all major mineral phases of a type B CAI from Allende. We have also studied an unusual fractionated CAI from Leoville and made the first oxygen isotopic measurements in rare CAIs from ordinary chondrites.

  13. Using synchrotron X-ray fluorescence microprobes in the study of metal homeostasis in plants

    PubMed Central

    Punshon, Tracy; Guerinot, Mary Lou; Lanzirotti, Antonio

    2009-01-01

    Background and Aims This Botanical Briefing reviews the application of synchrotron X-ray fluorescence (SXRF) microprobes to the plant sciences; how the technique has expanded our knowledge of metal(loid) homeostasis, and how it can be used in the future. Scope The use of SXRF microspectroscopy and microtomography in research on metal homeostasis in plants is reviewed. The potential use of SXRF as part of the ionomics toolbox, where it is able to provide fundamental information on the way that plants control metal homeostasis, is recommended. Conclusions SXRF is one of the few techniques capable of providing spatially resolved in-vivo metal abundance data on a sub-micrometre scale, without the need for chemical fixation, coating, drying or even sectioning of samples. This gives researchers the ability to uncover mechanisms of plant metal homeostasis that can potentially be obscured by the artefacts of sample preparation. Further, new generation synchrotrons with smaller beam sizes and more sensitive detection systems will allow for the imaging of metal distribution within single living plant cells. Even greater advances in our understanding of metal homeostasis in plants can be gained by overcoming some of the practical boundaries that exist in the use of SXRF analysis. PMID:19182222

  14. Using Synchrotron X-ray Fluorescence Microprobes in the Study of Metal Homeostasis in Plants

    SciTech Connect

    Punshon, T.; Guerinot, M; Lanzirotti, A

    2009-01-01

    Background and Aims: This Botanical Briefing reviews the application of synchrotron X-ray fluorescence (SXRF) microprobes to the plant sciences; how the technique has expanded our knowledge of metal(loid) homeostasis, and how it can be used in the future. Scope: The use of SXRF microspectroscopy and microtomography in research on metal homeostasis in plants is reviewed. The potential use of SXRF as part of the ionomics toolbox, where it is able to provide fundamental information on the way that plants control metal homeostasis, is recommended. Conclusions: SXRF is one of the few techniques capable of providing spatially resolved in-vivo metal abundance data on a sub-micrometre scale, without the need for chemical fixation, coating, drying or even sectioning of samples. This gives researchers the ability to uncover mechanisms of plant metal homeostasis that can potentially be obscured by the artefacts of sample preparation. Further, new generation synchrotrons with smaller beam sizes and more sensitive detection systems will allow for the imaging of metal distribution within single living plant cells. Even greater advances in our understanding of metal homeostasis in plants can be gained by overcoming some of the practical boundaries that exist in the use of SXRF analysis.

  15. Computational image analysis of nuclear morphology associated with various nuclear-specific aging disorders

    PubMed Central

    Choi, Siwon; Wang, Wei; Ribeiro, Alexandrew J.S.; Kalinowski, Agnieszka; Gregg, Siobhan Q.; Opresko, Patricia L.; Niedernhofer, Laura J.

    2011-01-01

    Computational image analysis is used in many areas of biological and medical research, but advanced techniques including machine learning remain underutilized. Here, we used automated segmentation and shape analyses, with pre-defined features and with computer generated components, to compare nuclei from various premature aging disorders caused by alterations in nuclear proteins. We considered cells from patients with Hutchinson-Gilford progeria syndrome (HGPS) with an altered nucleoskeletal protein; a mouse model of XFE progeroid syndrome caused by a deficiency of ERCC1-XPF DNA repair nuclease; and patients with Werner syndrome (WS) lacking a functional WRN exonuclease and helicase protein. Using feature space analysis, including circularity, eccentricity, and solidity, we found that XFE nuclei were larger and significantly more elongated than control nuclei. HGPS nuclei were smaller and rounder than the control nuclei with features suggesting small bumps. WS nuclei did not show any significant shape changes from control. We also performed principle component analysis (PCA) and a geometric, contour based metric. PCA allowed direct visualization of morphological changes in diseased nuclei, whereas standard, feature-based approaches required pre-defined parameters and indirect interpretation of multiple parameters. Both methods yielded similar results, but PCA proves to be a powerful pre-analysis methodology for unknown systems. PMID:22127259

  16. Geiger mode mapping: A new imaging modality for focused ion microprobes

    NASA Astrophysics Data System (ADS)

    Yang, Changyi; Hougaard, Christiaan R.; Bielejec, Edward; Caroll, Malcolm S.; Jamieson, David N.

    2015-04-01

    Geiger mode detectors fabricated in silicon are used to detect incident photons with high sensitivity. They are operated with large internal electric fields so that a single electron-hole pair can trigger an avalanche breakdown which generates a signal in an external circuit. We have applied a modified version of the ion beam induced charge technique in a nuclear microprobe system to investigate the application of Geiger mode detectors to detect discrete ion impacts. Our detectors are fabricated with an architecture based on the avalanche diode structure and operated with a transient bias voltage that activates the Geiger mode. In this mode avalanche breakdown is triggered by ion impact followed by diffusion of an electron-hole pair into the sensitive volume. The avalanche breakdown is quenched by removal of the transient bias voltage which is synchronized with a beam gate. An alternative operation mode is possible at lower bias voltages where the avalanche process self-quenches and the device exhibits linear charge gain as a consequence. Incorporation of such a device into a silicon substrate potentially allows the exceptional sensitivity of Geiger mode to register an electron-hole pair from sub-10 keV donor atom implants for the deterministic construction of shallow arrays of single atoms in the substrate required for emerging quantum technologies. Our characterization system incorporates a fast electrostatic ion beam switcher gated by the transient device bias, duration 800 ns, with a time delay, duration 500 ns, that allows for both the ion time of flight and the diffusion of the electron-hole pairs in the substrate into the sensitive region of the device following ion impact of a scanned 1 MeV H microbeam. We compare images at the micron scale mapping the response of the device to ion impact operated in both Geiger mode and avalanche (linear) mode for silicon devices engineered with this ultimate-sensitivity detector structure.

  17. Development of an NMR microprobe procedure for high-throughput environmental metabolomics of Daphnia magna.

    PubMed

    Nagato, Edward G; Lankadurai, Brian P; Soong, Ronald; Simpson, André J; Simpson, Myrna J

    2015-09-01

    Nuclear magnetic resonance (NMR) is the primary platform used in high-throughput environmental metabolomics studies because its non-selectivity is well suited for non-targeted approaches. However, standard NMR probes may limit the use of NMR-based metabolomics for tiny organisms because of the sample volumes required for routine metabolic profiling. Because of this, keystone ecological species, such as the water flea Daphnia magna, are not commonly studied because of the analytical challenges associated with NMR-based approaches. Here, the use of a 1.7-mm NMR microprobe in analyzing tissue extracts from D. magna is tested. Three different extraction procedures (D2O-based buffer, Bligh and Dyer, and acetonitrile : methanol : water) were compared in terms of the yields and breadth of polar metabolites. The D2O buffer extraction yielded the most metabolites and resulted in the best reproducibility. Varying amounts of D. magna dry mass were extracted to optimize metabolite isolation from D. magna tissues. A ratio of 1-1.5-mg dry mass to 40 µl of extraction solvent provided excellent signal-to-noise and spectral resolution using (1)H NMR. The metabolite profile of a single daphnid was also investigated (approximately 0.2 mg). However, the signal-to-noise of the (1)H NMR was considerably lower, and while feasible for select applications would likely not be appropriate for high-throughput NMR-based metabolomics. Two-dimensional NMR experiments on D. magna extracts were also performed using the 1.7-mm NMR probe to confirm (1)H NMR metabolite assignments. This study provides an NMR-based analytical framework for future metabolomics studies that use D. magna in ecological and ecotoxicity studies. PMID:25891518

  18. Nuclear Technology Series. Course 22: Advanced Radionuclide Analysis.

    ERIC Educational Resources Information Center

    Center for Occupational Research and Development, Inc., Waco, TX.

    This technical specialty course is one of thirty-five courses designed for use by two-year postsecondary institutions in five nuclear technician curriculum areas: (1) radiation protection technician, (2) nuclear instrumentation and control technician, (3) nuclear materials processing technician, (4) nuclear quality-assurance/quality-control…

  19. Molecular identification of foreign inclusions in inflammatory tissue surrounding metal implants by Fourier transform laser microprobe mass spectrometry.

    PubMed

    De Nollin, S; Poels, K; Van Vaeck, L; De Clerck, N; Bakker, A; Duwel, V; Vandevelde, D; Van Marck, E

    1997-01-01

    Fourier transform laser microprobe mass spectrometry (FT LMMS) is a novel technique for micro-analysis of solids with a lateral resolution in the 5 microns range. One of the major advantages of the technique is the capability to perform characterisation of the molecular composition of both organic and inorganic compounds. The information is directly deduced from the signals without the aid of reference spectra. FT LMMS was applied to the characterisation of black tissue fragments in a biopsy from a patient, in which a constrained condylar nodular knee system was implanted ten years ago. The tissue contained numerous foreign giant cells with a black non-birefringent pigment in their cytoplasm. FT LMMS analysis allowed us to detect directly by means of molecular signals, that the debris consisted primarily of titanium oxide and not metallic titanium, while the implant itself only contained titanium. PMID:9258958

  20. Molecular analysis of Baylisascaris columnaris revealed mitochondrial and nuclear polymorphisms

    PubMed Central

    2013-01-01

    Background Baylisascaris species are intestinal nematodes of skunks, raccoons, badgers, and bears belonging to the genus Ascarididae. Oral uptake of embryonated Baylisascaris sp. eggs by a wide variety of mammals and birds can lead to visceral, ocular and neurological larva migrans. B. procyonis, the raccoon roundworm, is known to cause severe illness in intermediate hosts and in humans, whereas the skunk roundworm B. columnaris is probably less pathogenic. Skunks and raccoons are kept as pets in Europe, sometimes together with cats and dogs, living in close contact with humans. B. procyonis and B. columnaris are difficult to differentiate based on morphological criteria and molecular and phylogenetic information concerning B. columnaris is missing. This is the first study on the genetic characterisation of B. columnaris, based on mitochondrial and nuclear molecular markers. Methods B. columnaris worms were isolated from pet skunks, and used for molecular analysis. PCR primers targeted at mitochondrial cytochrome c oxidase 1 and 2 (CO1 and CO2), ribosomal ITS1-5.8S-ITS2 and ribosomal 28S genes were used. DNA sequences from B. columnaris, B. procyonis and B. transfuga from bears were analysed by cluster analysis. Results Four different multi-locus genotypes were found in B. columnaris, based on 14 single nucleotide polymorphisms (SNPs) and two insertions / deletions in CO1, CO2, ITS1-5.8S-ITS2 and 28S. Conclusions The genetic characteristics of B. columnaris show close resemblance to those of B. procyonis, but in contrast to B. procyonis, show several polymorphisms in both mitochondrial and nuclear markers. These polymorphisms could be used as a tool to differentiate B. columnaris from B. procyonis in molecular diagnostic assays, and to identify B. columnaris by PCR, in addition to or replacing morphometric analysis. This might lead to more insight into the zoonotic relevance of B. columnaris in humans. PMID:23627901

  1. Numerical analysis of a nuclear fuel element for nuclear thermal propulsion

    NASA Technical Reports Server (NTRS)

    Wang, Ten-See; Schutzenhofer, Luke

    1991-01-01

    A computational fluid dynamics model with porosity and permeability formulations in the transport equations has been developed to study the concept of nuclear thermal propulsion through the analysis of a pulsed irradiation of a particle bed element (PIPE). The numerical model is a time-accurate pressure-based formulation. An adaptive upwind scheme is employed for spatial discretization. The upwind scheme is based on second- and fourth-order central differencing with adaptive artificial dissipation. Multiblocked porosity regions have been formulated to model the cold frit, particle bed, and hot frit. Multiblocked permeability regions have been formulated to describe the flow shaping effect from the thickness-varying cold frit. Computational results for several zero-power density PIPEs and an elevated-particle-temperature PIPE are presented. The implications of the computational results are discussed.

  2. An Empirical Analysis of Human Performance and Nuclear Safety Culture

    SciTech Connect

    Jeffrey Joe; Larry G. Blackwood

    2006-06-01

    The purpose of this analysis, which was conducted for the US Nuclear Regulatory Commission (NRC), was to test whether an empirical connection exists between human performance and nuclear power plant safety culture. This was accomplished through analyzing the relationship between a measure of human performance and a plant’s Safety Conscious Work Environment (SCWE). SCWE is an important component of safety culture the NRC has developed, but it is not synonymous with it. SCWE is an environment in which employees are encouraged to raise safety concerns both to their own management and to the NRC without fear of harassment, intimidation, retaliation, or discrimination. Because the relationship between human performance and allegations is intuitively reciprocal and both relationship directions need exploration, two series of analyses were performed. First, human performance data could be indicative of safety culture, so regression analyses were performed using human performance data to predict SCWE. It also is likely that safety culture contributes to human performance issues at a plant, so a second set of regressions were performed using allegations to predict HFIS results.

  3. Climatographic analysis of the Zion nuclear power station site

    SciTech Connect

    Lyons, W.A.; Venne, M.G.; Keen, C.S.; Miller, C.W.; Whitcomb, R.C.

    1989-01-01

    The computerized emergency response dose assessment codes (ERDACs) used in the nuclear industry commonly rely on Gaussian plume dispersion techniques. In coastal zones, particularly within 15 km of the shoreline, complex four-dimensional mesoscale meteorological regimes often violate some of the basic assumptions of Gaussian dispersion. For example, a land breeze will initially advect materials offshore into unpopulated areas. Such effluents may pool over water only to return to land in the next morning's onshore flow, but in locations and concentrations unknown and undeterminable from on-site data and standard Gaussian modeling techniques. Improving the performance of ERDACs for a given coastal site requires a climatographic inventory of that site and its surroundings. This involves identifying the coastal mesoscale regimes (CMRs) that affect the site, including their annual frequencies of occurrence and the meteorological conditions that characterize them. Such a climatographic analysis has been performed for the Zion nuclear power station (NPS), which is located just north of Chicago, Illinois, on the western shore of southern Lake Michigan. The purpose of this paper is to summarize the results of this study and its implications for radiological emergency response activities.

  4. Climatographic analysis of the Zion Nuclear Power Station site

    SciTech Connect

    Miller, C.W.; Whitcomb, R.C. ); Lyons, W.A.; Venne, M.G.; Keen, C.S.

    1989-01-01

    The computerized emergency response dose assessment codes (ERDACs) used in the nuclear industry commonly rely on Gaussian plume dispersion techniques. In coastal zones, particularly within 15 km of the shoreline, complex four-dimensional mesoscale meteorological regimes often violate some of the basic assumptions of Gaussian dispersion. For example a land breeze will initially advect materials offshore into unpopulated areas. Such effluents may pool over water only to return to land in the next morning's onshore flow, but in locations and concentrations unknown and undeterminable from on-site data and standard Gaussian modeling techniques. Improving the performance of ERDACs for a given coastal site requires a climatographic inventory of that site and its surroundings. This involves identifying the coastal mesoscale regimes (CMRs) that affect the site, including their annual frequencies of occurrence and the meteorological conditions that characterize them. Such a climatographic analysis has been performed for the Zion nuclear power station (NPS), which is located just north of Chicago, Illinois, on the western shore of southern Lake Michigan. The purpose of this papers is to summarize the results of this study and its implications for radiological emergency response activities. A conceptual framework for allocating resources in developing an adequate emergency response system includes three major factors: (1) frequency of the mesoscale regimes; (2) extent to which the regime can result in high concentrations/doses; (3) ease with which it can be modeled, with due consideration given for input data requirements.

  5. In situ structural analysis of the human nuclear pore complex

    PubMed Central

    Ori, Alessandro; DiGuilio, Amanda L.; Vollmer, Benjamin; Mackmull, Marie-Therese; Banterle, Niccolo; Parca, Luca; Kastritis, Panagiotis; Buczak, Katarzyna; Mosalaganti, Shyamal; Hagen, Wim; Andres-Pons, Amparo; Lemke, Edward A.; Bork, Peer; Antonin, Wolfram; Glavy, Joseph S.; Bui, Khanh Huy; Beck, Martin

    2016-01-01

    Summary Nuclear pore complexes (NPCs) are fundamental components of all eukaryotic cells that mediate nucleocytoplasmic exchange. Elucidating their 110 MDa structure imposes a formidable challenge and requires in situ structural biology approaches. Fifteen out of about thirty nucleoporins (Nups) are structured and form the Y- and inner ring complexes. These two major scaffolding modules assemble in multiple copies into an eight-fold rotationally symmetric structure that fuses the inner and outer nuclear membranes to form a central channel of ∼60 nm in diameter 1. The scaffold is decorated with transport channel Nups that often contain phenylalanine (FG)-repeat sequences and mediate the interaction with cargo complexes. Although the architectural arrangement of parts of the Y-complex has been elucidated, it is unclear how exactly it oligomerizes in situ. Here, we combined cryo electron tomography with mass spectrometry, biochemical analysis, perturbation experiments and structural modeling to generate the most comprehensive architectural model of the NPC to date. Our data suggest previously unknown protein interfaces across Y-complexes and to inner ring complex members. We demonstrate that the higher eukaryotic transport channel Nup358 (RanBP2) has a previously unanticipated role in Y-complex oligomerization. Our findings blur the established boundaries between scaffold and transport channel Nups. We conclude that, similarly to coated vesicles, multiple copies of the same structural building block - although compositionally identical - engage in different local sets of interactions and conformations. PMID:26416747

  6. Integration of facility modeling capabilities for nuclear nonproliferation analysis

    SciTech Connect

    Burr, Tom; Gorensek, M. B.; Krebs, John; Kress, Reid L; Lamberti, Vincent; Schoenwald, David; Ward, Richard C

    2012-01-01

    Developing automated methods for data collection and analysis that can facilitate nuclearnonproliferation assessment is an important research area with significant consequences for the effective global deployment of nuclear energy. Facilitymodeling that can integrate and interpret observations collected from monitored facilities in order to ascertain their functional details will be a critical element of these methods. Although improvements are continually sought, existing facilitymodeling tools can characterize all aspects of reactor operations and the majority of nuclear fuel cycle processing steps, and include algorithms for data processing and interpretation. Assessing nonproliferation status is challenging because observations can come from many sources, including local and remote sensors that monitor facility operations, as well as open sources that provide specific business information about the monitored facilities, and can be of many different types. Although many current facility models are capable of analyzing large amounts of information, they have not been integrated in an analyst-friendly manner. This paper addresses some of these facilitymodelingcapabilities and illustrates how they could be integrated and utilized for nonproliferationanalysis. The inverse problem of inferring facility conditions based on collected observations is described, along with a proposed architecture and computer framework for utilizing facilitymodeling tools. After considering a representative sampling of key facilitymodelingcapabilities, the proposed integration framework is illustrated with several examples.

  7. The Activities of the European Consortium on Nuclear Data Development and Analysis for Fusion

    NASA Astrophysics Data System (ADS)

    Fischer, U.; Avrigeanu, M.; Avrigeanu, V.; Cabellos, O.; Kodeli, I.; Koning, A.; Konobeyev, A. Yu.; Leeb, H.; Rochman, D.; Pereslavtsev, P.; Sauvan, P.; Sublet, J.-C.; Trkov, A.; Dupont, E.; Leichtle, D.; Izquierdo, J.

    2014-06-01

    This paper presents an overview of the activities of the European Consortium on Nuclear Data Development and Analysis for Fusion. The Consortium combines available European expertise to provide services for the generation, maintenance, and validation of nuclear data evaluations and data files relevant for ITER, IFMIF and DEMO, as well as codes and software tools required for related nuclear calculations.

  8. The Activities of the European Consortium on Nuclear Data Development and Analysis for Fusion

    SciTech Connect

    Fischer, U.; Avrigeanu, M.; Avrigeanu, V.; Cabellos, O.; Kodeli, I.; Koning, A.; Konobeyev, A.Yu.; Leeb, H.; Rochman, D.; Pereslavtsev, P.; Sauvan, P.; Sublet, J.-C.; Dupont, E.; Leichtle, D.; Izquierdo, J.

    2014-06-15

    This paper presents an overview of the activities of the European Consortium on Nuclear Data Development and Analysis for Fusion. The Consortium combines available European expertise to provide services for the generation, maintenance, and validation of nuclear data evaluations and data files relevant for ITER, IFMIF and DEMO, as well as codes and software tools required for related nuclear calculations.

  9. Global NLO Analysis of Nuclear Parton Distribution Functions

    SciTech Connect

    Hirai, M.; Kumano, S.; Nagai, T.-H.

    2008-02-21

    Nuclear parton distribution functions (NPDFs) are determined by a global analysis of experimental measurements on structure-function ratios F{sub 2}{sup A}/F{sub 2}{sup A{sup '}} and Drell-Yan cross section ratios {sigma}{sub DY}{sup A}/{sigma}{sub DY}{sup A{sup '}}, and their uncertainties are estimated by the Hessian method. The NPDFs are obtained in both leading order (LO) and next-to-leading order (NLO) of {alpha}{sub s}. As a result, valence-quark distributions are relatively well determined, whereas antiquark distributions at x>0.2 and gluon distributions in the whole x region have large uncertainties. The NLO uncertainties are slightly smaller than the LO ones; however, such a NLO improvement is not as significant as the nucleonic case.

  10. A Nuclear Reaction Analysis study of fluorine uptake in flint

    SciTech Connect

    Jin, Jian-Yue; Weathers, D. L.; Picton, F.; Hughes, B. F.; Duggan, J. L.; McDaniel, F. D.; Matteson, S.

    1999-06-10

    Nuclear Reaction Analysis (NRA) using the {sup 19}F(p,{alpha}{gamma}){sup 16}O resonance reaction is a powerful method of fluorine depth profiling. We have used this method to study the fluorine uptake phenomenon in mineral flint, which could potentially develop into a method of dating archeological flint artifacts. Flint samples cut with a rock saw were immersed in aqueous fluoride solutions for different times for the uptake study. The results suggest that fluorine uptake is not a simple phenomenon, but rather a combination of several simultaneous processes. Fluorine surface adsorption appears to play an important role in developing the fluorine profiles. The surface adsorption was affected by several parameters such as pH value and fluorine concentration in the solution, among others. The problem of surface charging for the insulator materials during ion bombardment is also reported.

  11. Zircon geochronology and ca. 400 Ma exhumation of Norwegian ultrahigh-pressure rocks: An ion microprobe and chemical abrasion study

    USGS Publications Warehouse

    Root, D.B.; Hacker, B.R.; Mattinson, J.M.; Wooden, J.L.

    2004-01-01

    Understanding the formation and exhumation of the remarkable ultrahigh-pressure (UHP) rocks of the Western Gneiss Region, Norway, hinges on precise determination of the time of eclogite recrystallization. We conducted detailed thermal ionization mass spectrometry, chemical abrasion analysis and sensitive high-resolution ion-microprobe analysis of zircons from four ultrahigh- and high-pressure (HP) rocks. Ion-microprobe analyses from the Flatraket eclogite yielded a broad range of apparently concordant Caledonian ages, suggesting long-term growth. In contrast, higher precision thermal ionization mass spectrometry analysis of zircon subject to combined thermal annealing and multi-step chemical abrasion yielded moderate Pb loss from the first (lowest temperature) abrasion step, possible minor Pb loss or minor growth at 400 Ma from the second step and a 407-404 Ma cluster of slightly discordant 206Pb/238U ages, most likely free from Pb loss, from the remaining abrasion steps. We interpret the latter to reflect zircon crystallization at ???405-400 Ma with minor discordance from inherited cores. Zircon crystallization occurred at eclogite-facies, possibly post-peak conditions, based on compositions of garnet inclusions in zircon as well as nearly flat HREE profiles and lack of Eu anomalies in zircon fractions subjected to chemical abrasion. These ages are significantly younger than the 425 Ma age often cited for western Norway eclogite recrystallization, implying faster rates of exhumation (>2.5-8.5 km/Myr), and coeval formation of eclogites across the UHP portion of the Western Gneiss Region. ?? 2004 Published by Elsevier B.V.

  12. Polymer SU-8 Based Microprobes for Neural Recording and Drug Delivery

    NASA Astrophysics Data System (ADS)

    Altuna, Ane; Fernandez, Luis; Berganzo, Javier

    2015-06-01

    This manuscript makes a reflection about SU-8 based microprobes for neural activity recording and drug delivery. By taking advantage of improvements in microfabrication technologies and using polymer SU-8 as the only structural material, we developed several microprobe prototypes aimed to: a) minimize injury in neural tissue, b) obtain high-quality electrical signals and c) deliver drugs at a micrometer precision scale. Dedicated packaging tools have been developed in parallel to fulfill requirements concerning electric and fluidic connections, size and handling. After these advances have been experimentally proven in brain using in vivo preparation, the technological concepts developed during consecutive prototypes are discussed in depth now.

  13. Core Community Specifications for Electron Microprobe Operating Systems: Software, Quality Control, and Data Management Issues

    NASA Technical Reports Server (NTRS)

    Fournelle, John; Carpenter, Paul

    2006-01-01

    Modem electron microprobe systems have become increasingly sophisticated. These systems utilize either UNIX or PC computer systems for measurement, automation, and data reduction. These systems have undergone major improvements in processing, storage, display, and communications, due to increased capabilities of hardware and software. Instrument specifications are typically utilized at the time of purchase and concentrate on hardware performance. The microanalysis community includes analysts, researchers, software developers, and manufacturers, who could benefit from exchange of ideas and the ultimate development of core community specifications (CCS) for hardware and software components of microprobe instrumentation and operating systems.

  14. Development of nuclear analysis capabilities for DOE waste management activities

    SciTech Connect

    Parks, C.V.; DeHart, M.D.; Broadhead, B.L.; Hopper, C.M.; Petrie, L.M.

    1998-05-01

    The objective of this project is to develop and demonstrate prototypic analysis capabilities that can be used by the nuclear safety analysis practitioners to: (1) demonstrate a more thorough understanding of the underlying physics phenomena that can lead to improved reliability and defensibility of safety evaluations; and (2) optimize operations related to the handling, storage, transportation, and disposal of fissile material and DOE spent fuel. To address these problems, the project will investigate the implementation of sensitivity and uncertainty methods within existing Monte Carlo codes used for criticality safety analyses, as well as within a new deterministic code that allows specification of arbitrary grids to accurately model the geometry details required in a criticality safety analysis. This capability can facilitate improved estimations of the required subcritical margin and potentially enable the use of a broader range of experiments in the validation process. The new arbitrary-grid radiation transport code will also enable detailed geometric modeling valuable for improved accuracy in application to a myriad of other problems related to waste characterization. Application to these problems will also be explored.

  15. Summary of Prometheus Radiation Shielding Nuclear Design Analysis

    SciTech Connect

    J. Stephens

    2006-01-13

    This report transmits a summary of radiation shielding nuclear design studies performed to support the Prometheus project. Together, the enclosures and references associated with this document describe NRPCT (KAPL & Bettis) shielding nuclear design analyses done for the project.

  16. Proton microprobe and X-ray fluorescence investigations of nickel distribution in serpentine flora from South Africa

    NASA Astrophysics Data System (ADS)

    Mesjasz-Przybyłowicz, J.; Balkwill, K.; Przybyłowicz, W. J.; Annegarn, H. J.

    1994-05-01

    Certain plant species growing on serpentinite soils are hyperaccumulative of Ni. The ability to tolerate high Ni levels may have useful environmental and economic implications. However, the processes of Ni accumulation and tolerance are not well understood. The proton microprobe of the Schonland Research Centre was used in the PIXE mode to map the lateral and cross-sectional distribution of Ni and other elements in the tissue of species from the family Asteraceae, growing on serpentine outcrops in the Barberton district, south-eastern Transvaal. Elemental maps showed that the highest Ni enrichment was in the epidermis. Energy dispersive XRF fluorescence analysis was used for qualitative rapid scanning to select suitable metal-rich plants and for quantitative bulk analyses.

  17. Experimental determination of the partitioning of gallium between solid iron metal and synthetic basaltic melt Electron and ion microprobe study

    NASA Technical Reports Server (NTRS)

    Drake, M. J.; Newsom, H. E.; Reed, S. J. B.; Enright, M. C.

    1984-01-01

    The distribution of Ga between solid Fe metal and synthetic basaltic melt is investigated experimentally at temperatures of 1190 and 1330 C, and over a narrow range of oxygen fugacities. Metal-silicate reversal experiments were conducted, indicating a close approach to equilibrium. The analysis of the partitioned products was performed using electron and ion microprobes. At one bar total pressure, the solid metal/silicate melt partition coefficient D(Ga) is used to evaluate metal-silicate fractionation processes in the earth, moon, and Eucrite Parent Body (EPB). It is found that the depletion of Ga abundances in the EPB is due to the extraction of Ga into a metallic core. Likewise, the depletion of Ga in the lunar mantle is consistent with the extraction of Ga into a smaller lunar core if Ga was originally present in a subchondritic concentration. The relatively high Ga abundances in the earth's mantle are discussed, with reference to several theoretical models.

  18. High-order harmonic generation from polyatomic molecules including nuclear motion and a nuclear modes analysis

    SciTech Connect

    Madsen, C. B.; Abu-samha, M.; Madsen, L. B.

    2010-04-15

    We present a generic approach for treating the effect of nuclear motion in high-order harmonic generation from polyatomic molecules. Our procedure relies on a separation of nuclear and electron dynamics where we account for the electronic part using the Lewenstein model and nuclear motion enters as a nuclear correlation function. We express the nuclear correlation function in terms of Franck-Condon factors, which allows us to decompose nuclear motion into modes and identify the modes that are dominant in the high-order harmonic generation process. We show results for the isotopes CH{sub 4} and CD{sub 4} and thereby provide direct theoretical support for a recent experiment [S. Baker et al., Science 312, 424 (2006)] that uses high-order harmonic generation to probe the ultrafast structural nuclear rearrangement of ionized methane.

  19. High-order harmonic generation from polyatomic molecules including nuclear motion and a nuclear modes analysis

    NASA Astrophysics Data System (ADS)

    Madsen, C. B.; Abu-Samha, M.; Madsen, L. B.

    2010-04-01

    We present a generic approach for treating the effect of nuclear motion in high-order harmonic generation from polyatomic molecules. Our procedure relies on a separation of nuclear and electron dynamics where we account for the electronic part using the Lewenstein model and nuclear motion enters as a nuclear correlation function. We express the nuclear correlation function in terms of Franck-Condon factors, which allows us to decompose nuclear motion into modes and identify the modes that are dominant in the high-order harmonic generation process. We show results for the isotopes CH4 and CD4 and thereby provide direct theoretical support for a recent experiment [S. Baker , Science 312, 424 (2006)] that uses high-order harmonic generation to probe the ultrafast structural nuclear rearrangement of ionized methane.

  20. Nuclear Forensic Science: Analysis of Nuclear Material Out of Regulatory Control

    NASA Astrophysics Data System (ADS)

    Kristo, Michael J.; Gaffney, Amy M.; Marks, Naomi; Knight, Kim; Cassata, William S.; Hutcheon, Ian D.

    2016-06-01

    Nuclear forensic science seeks to identify the origin of nuclear materials found outside regulatory control. It is increasingly recognized as an integral part of a robust nuclear security program. This review highlights areas of active, evolving research in nuclear forensics, with a focus on analytical techniques commonly employed in Earth and planetary sciences. Applications of nuclear forensics to uranium ore concentrates (UOCs) are discussed first. UOCs have become an attractive target for nuclear forensic researchers because of the richness in impurities compared to materials produced later in the fuel cycle. The development of chronometric methods for age dating nuclear materials is then discussed, with an emphasis on improvements in accuracy that have been gained from measurements of multiple radioisotopic systems. Finally, papers that report on casework are reviewed, to provide a window into current scientific practice.

  1. Quantifying trace elements in individual aquatic protist cells with a synchrotron X-ray fluorescence microprobe.

    PubMed

    Twining, Benjamin S; Baines, Stephen B; Fisher, Nicholas S; Maser, Jörg; Vogt, Stefan; Jacobsen, Chris; Tovar-Sanchez, Antonio; Sañudo-Wilhelmy, Sergio A

    2003-08-01

    The study of trace metal cycling by aquatic protists is limited by current analytical techniques. Standard "bulk" element analysis techniques that rely on physical separations to concentrate cells for analysis cannot separate cells from co-occurring detrital material or other cells of differing taxonomy or trophic function. Here we demonstrate the ability of a synchrotron-based X-ray fluorescence (SXRF) microprobe to quantify the elements Si, Mn, Fe, Ni, and Zn in individual aquatic protist cells. This technique distinguishes between different types of cells in an assemblage and between cells and other particulate matter. Under typical operating conditions, the minimum detection limits are 7.0 x 10(-16) mol microm(-2) for Si and between 5.0 x 10(-20) and 3.9 x 10(-19) mol microm(-2) for Mn, Fe, Ni, and Zn; this sensitivity is sufficient to detect these elements in cells from even the most pristine waters as demonstrated in phytoplankton cells collected from remote areas of the Southern Ocean. Replicate analyses of single cells produced variations of <5% for Si, Mn, Fe, and Zn and <10% for Ni. Comparative analyses of cultured phytoplankton cells generally show no significant differences in cellular metal concentrations measured with SXRF and standard bulk techniques (spectrophotometry and graphite furnace atomic absorption spectrometry). SXRF also produces two-dimensional maps of element distributions in cells, thereby providing information not available with other analytical approaches. This technique enables the accurate and precise measurement of trace metals in individual aquatic protists collected from natural environments. PMID:14572047

  2. Quantifying trace elements in individual aquatic protist cells with a synchrotron x-ray fluorescence microprobe.

    SciTech Connect

    Twining, B. S.; Baines, S. B.; Fisher, N. S.; Maser, J.; Vogt, S.; Jacobsen, C.; Tovar-Sanchez, A.; Sanudo-Wihelmy, S. A.; Experimental Facilities Division; Stony Brook Univ.

    2003-01-01

    The study of trace metal cycling by aquatic protists is limited by current analytical techniques. Standard 'bulk' element analysis techniques that rely on physical separations to concentrate cells for analysis cannot separate cells from co-occurring detrital material or other cells of differing taxonomy or trophic function. Here we demonstrate the ability of a synchrotron-based X-ray fluorescence (SXRF) microprobe to quantify the elements Si, Mn, Fe, Ni, and Zn in individual aquatic protist cells. This technique distinguishes between different types of cells in an assemblage and between cells and other particulate matter. Under typical operating conditions, the minimum detection limits are 7.0 x 10{sup -16} mol {mu}m{sup -2} for Si and between 5.0 x 10{sup -20} and 3.9 x 10{sup -19} mol {mu}m{sup -2} for Mn, Fe, Ni, and Zn; this sensitivity is sufficient to detect these elements in cells from even the most pristine waters as demonstrated in phytoplankton cells collected from remote areas of the Southern Ocean. Replicate analyses of single cells produced variations of <5% for Si, Mn, Fe, and Zn and <10% for Ni. Comparative analyses of cultured phytoplankton cells generally show no significant differences in cellular metal concentrations measured with SXRF and standard bulk techniques (spectrophotometry and graphite furnace atomic absorption spectrometry). SXRF also produces two-dimensional maps of element distributions in cells, thereby providing information not available with other analytical approaches. This technique enables the accurate and precise measurement of trace metals in individual aquatic protists collected from natural environments.

  3. A probabilistic safety analysis of incidents in nuclear research reactors.

    PubMed

    Lopes, Valdir Maciel; Agostinho Angelo Sordi, Gian Maria; Moralles, Mauricio; Filho, Tufic Madi

    2012-06-01

    This work aims to evaluate the potential risks of incidents in nuclear research reactors. For its development, two databases of the International Atomic Energy Agency (IAEA) were used: the Research Reactor Data Base (RRDB) and the Incident Report System for Research Reactor (IRSRR). For this study, the probabilistic safety analysis (PSA) was used. To obtain the result of the probability calculations for PSA, the theory and equations in the paper IAEA TECDOC-636 were used. A specific program to analyse the probabilities was developed within the main program, Scilab 5.1.1. for two distributions, Fischer and chi-square, both with the confidence level of 90 %. Using Sordi equations, the maximum admissible doses to compare with the risk limits established by the International Commission on Radiological Protection (ICRP) were obtained. All results achieved with this probability analysis led to the conclusion that the incidents which occurred had radiation doses within the stochastic effects reference interval established by the ICRP-64. PMID:22021060

  4. Commercial Spent Nuclear Fuel Waste Package Misload Analysis

    SciTech Connect

    A. Alsaed

    2005-07-28

    The purpose of this calculation is to estimate the probability of misloading a commercial spent nuclear fuel waste package with a fuel assembly(s) that has a reactivity (i.e., enrichment and/or burnup) outside the waste package design. The waste package designs are based on the expected commercial spent nuclear fuel assemblies and previous analyses (Macheret, P. 2001, Section 4.1 and Table 1). For this calculation, a misloaded waste package is defined as a waste package that has a fuel assembly(s) loaded into it with an enrichment and/or burnup outside the waste package design. An example of this type of misload is a fuel assembly designated for the 21-PWR Control Rod waste package being incorrectly loaded into a 21-PWR Absorber Plate waste package. This constitutes a misloaded 21-PWR Absorber Plate waste package, because the reactivity (i.e., enrichment and/or burnup) of a 21-PWR Control Rod waste package fuel assembly is outside the design of a 21-PWR Absorber Plate waste package. These types of misloads (i.e., fuel assembly with enrichment and/or burnup outside waste package design) are the only types that are evaluated in this calculation. This calculation utilizes information from ''Frequency of SNF Misload for Uncanistered Fuel Waste Package'' (CRWMS M&O 1998) as the starting point. The scope of this calculation is limited to the information available. The information is based on the whole population of fuel assemblies and the whole population of waste packages, because there is no information about the arrival of the waste stream at this time. The scope of this calculation deviates from that specified in ''Technical Work Plan for: Risk and Criticality Department'' (BSC 2002a, Section 2.1.30) in that only waste package misload is evaluated. The remaining issues identified (i.e., flooding and geometry reconfiguration) will be addressed elsewhere. The intended use of the calculation is to provide information and inputs to the Preclosure Safety Analysis

  5. Commercial Spent Nuclear Fuel Waste Package Misload Analysis

    SciTech Connect

    J.K. Knudson

    2003-10-02

    The purpose of this calculation is to estimate the probability of misloading a commercial spent nuclear fuel waste package with a fuel assembly(s) that has a reactivity (i.e., enrichment and/or burnup) outside the waste package design. The waste package designs are based on the expected commercial spent nuclear fuel assemblies and previous analyses (Macheret, P. 2001, Section 4.1 and Table 1). For this calculation, a misloaded waste package is defined as a waste package that has a fuel assembly(s) loaded into it with an enrichment and/or burnup outside the waste package design. An example of this type of misload is a fuel assembly designated for the 21-PWR Control Rod waste package being incorrectly loaded into a 21-PWR Absorber Plate waste package. This constitutes a misloaded 21-PWR Absorber Plate waste package, because the reactivity (i.e., enrichment and/or burnup) of a 21-PWR Control Rod waste package fuel assembly is outside the design of a 21-PWR Absorber Plate waste package. These types of misloads (i.e., fuel assembly with enrichment and/or burnup outside waste package design) are the only types that are evaluated in this calculation. This calculation utilizes information from ''Frequency of SNF Misload for Uncanistered Fuel Waste Package'' (CRWMS M&O 1998) as the starting point. The scope of this calculation is limited to the information available. The information is based on the whole population of fuel assemblies and the whole population of waste packages, because there is no information about the arrival of the waste stream at this time. The scope of this calculation deviates from that specified in ''Technical Work Plan for: Risk and Criticality Department'' (BSC 2002a, Section 2.1.30) in that only waste package misload is evaluated. The remaining issues identified (i.e., flooding and geometry reconfiguration) will be addressed elsewhere. The intended use of the calculation is to provide information and inputs to the Preclosure Safety Analysis

  6. Regression analysis of technical parameters affecting nuclear power plant performances

    SciTech Connect

    Ghazy, R.; Ricotti, M. E.; Trueco, P.

    2012-07-01

    Since the 80's many studies have been conducted in order to explicate good and bad performances of commercial nuclear power plants (NPPs), but yet no defined correlation has been found out to be totally representative of plant operational experience. In early works, data availability and the number of operating power stations were both limited; therefore, results showed that specific technical characteristics of NPPs were supposed to be the main causal factors for successful plant operation. Although these aspects keep on assuming a significant role, later studies and observations showed that other factors concerning management and organization of the plant could instead be predominant comparing utilities operational and economic results. Utility quality, in a word, can be used to summarize all the managerial and operational aspects that seem to be effective in determining plant performance. In this paper operational data of a consistent sample of commercial nuclear power stations, out of the total 433 operating NPPs, are analyzed, mainly focusing on the last decade operational experience. The sample consists of PWR and BWR technology, operated by utilities located in different countries, including U.S. (Japan)) (France)) (Germany)) and Finland. Multivariate regression is performed using Unit Capability Factor (UCF) as the dependent variable; this factor reflects indeed the effectiveness of plant programs and practices in maximizing the available electrical generation and consequently provides an overall indication of how well plants are operated and maintained. Aspects that may not be real causal factors but which can have a consistent impact on the UCF, as technology design, supplier, size and age, are included in the analysis as independent variables. (authors)

  7. Examination of Surveyor 3 parts with the scanning electron microscope and electron microprobe

    NASA Technical Reports Server (NTRS)

    Chodos, A. A.; Devaney, J. R.; Evens, K. C.

    1972-01-01

    Two screws and two washers, several small chips of tubing, and a fiber removed from a third screw were examined with the scanning electron microscope and the electron microprobe. The purpose of the examination was to determine the nature of the material on the surface of these samples and to search for the presence of meteoritic material.

  8. Chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade uranyl nitrate solutions

    SciTech Connect

    Not Available

    1981-01-01

    The standard covers analytical procedures to determine compliance of nuclear-grade uranyl nitrate solution to specifications. The following methods are described in detail: uranium by ferrous sulfate reduction-potassium dichromate titrimetry and by ignition gravimetry; specific gravity by pycnometry; free acid by oxalate complexation; thorium by the Arsenazo(III) (photometric) method; chromium by the diphenylcarbazide (photometric) method; molybdenum by the thiocyanate (photometric) method; halogens separation by steam distillation; fluorine by specific ion electrode; halogen distillate analysis: chloride, bromide and iodide by amperometric microtitrimetry; bromine by the fluorescein (photometric) method; sulfate sulfur by (photometric) turbidimetry; phosphorus by the molybdenum blue (photometric) method; silicon by the molybdenum blue (photometric) method; carbon by persulfate oxidation-acid titrimetry; nonvolatile impurities by spectrography; volatile impurities by rotating-disk spark spectrography; boron by emission spectrography; impurity elements by spark source mass spectrography; isotopic composition by multiple filament surface-ionization mass spectrometry; uranium-232 by alpha spectrometry; total alpha activity by direct alpha counting; fission product activity by beta and gamma counting; entrained organic matter by infrared spectrophotometry. (JMT)

  9. Mapping the Earth's mantle in 4D using the proton microprobe

    NASA Astrophysics Data System (ADS)

    Griffin, W. L.; Ryan, C. G.; Win, T. T.

    1995-09-01

    The CSIRO proton microprobe is used to study the trace element chemistry of garnet and chromite grains recovered from kimberlites and other volcanic rocks, both to develop new diamond exploration methods and to further understanding of the makeup and evolution of the earth's upper mantle. Analysis of the partitioning of trace and major elements between garnet and chromite and their coexisting phases in mantle rocks has led to the development of two single-mineral thermometers and a barometer. Trace Ni in Cr-pyrope garnet is used to determine the equilibration temperature ( TNi) of each garnet grain. This is the temperature of the garnet in its source rock before it was entrained in the erupting magma. Similarly, trace Zn in chromite yields an estimate ( TZn) of its equilibration temperature. To relate these temperature to depth in the lithosphere a measure of pressure ( PCr) has been developed that estimates pressure directly from Cr-pyrope garnet composition and TNi. This breakthrough enables the information on rock composition and metasomatic processes held in the trace and major element chemistry of each garnet to be located in P and T and thus placed in its stratigraphic context. Y, Ga and Cr provide information on mantle depletion by partial melting. Zr, Y and Ti provide clues to metasomatic processes such as infiltration of asthenospheric melts. Together the result is both an improved diamond exploration tool and a method of mapping the 3D structure, lithology and metasomatic processes in the lithosphere. With the added knowledge of the date of each intrusion, these methods permit the construction of 4D maps of the lithosphere, charting variation in mantle composition both laterally, with depth and through time.

  10. Ion microprobe U-Pb dating and REE abundance of biogenic apatite

    NASA Astrophysics Data System (ADS)

    Sano, Y.; Terada, K.; Ueki, S.

    2001-12-01

    If the direct U-Pb dating of a fossil itself is possible, the method could have great impact on stratigraphic studies in establishing the absolute chronology of sedimentary sequences. Micro fossil ?conodont? are candidates for this purpose since they consist of apatite (Ca2(PO5)3 (F,Cl,OH)), which would uptake U, Th and Pb after sedimentation no longer than a few million years and is supposed to remain closed to U and Pb under relatively low effective closure temperature. We report here results of direct ion microprobe U-Th-Pb dating of two conodonts; Trichognathus from Kinderhookian stage of Mississippian sedimentary sequence from Illinois Basin region in North America and Panderodus from a Llandoverian sedimentary sequence on Langkawi Island, northern Malaysia. Secondary purpose of the study is to indicate in situ analysis of all REE on the same spots of U-Pb measurements. Samples were cast into epoxy resin discs with a few grains of standard apatite, PRAP, derived from an alkaline rock of Prairie Lake circular complex in the Canadian Shield and polished until they were exposed through their mid-sections. U, Th and REE abundances, and Pb isotopic compositions were measured by using SHRIMP installed at Hiroshima University. Thirteen spots on Trichognathus yield a 238U/206Pb isochron age of 323+/-36 Ma, which is consistent with the depositional and early diagenetic ages. Fifteen spots on Panderodus give 232Th/208Pb isochron age of 429+/-50 Ma, which is again comparable to an early Silurian. Shale-normalized REE of Trichognathus shows a broadly flat pattern from light to middle REE and a decrease from middle to heavy REE with negative anomalies of Ce and Eu. In contrast Panderodus indicates a concave-shape pattern with middle REE enrichment. These characteristics are probably due to a different formation environment as suggested by other workers.

  11. Sulfide formation in reservoir carbonates of the Devonian Nisku Formation, Alberta, Canada: An ion microprobe study

    SciTech Connect

    Riciputi, L.R.; Cole, D.R.; Machel, H.G.

    1996-01-01

    The processes affecting sulfur during diagenesis in carbonates have been investigated by ion microprobe analysis of {sigma} {sup 34}S values of pyrite, marcasite, and anhydrite from the Devonian Nisku Formation in the Western Canada Sedimentary Basin. Pyrite and marcasite from three Nisku wells have {sigma}{sup 34}S ranging between -35 and +20{per_thousand}. The {sigma}{sup 34}S values increase b6y up to 50{per_thousand} with increasing well depth in two different Nisku wells, and {sigma}{sup 34}S also increases by up to 15{per_thousand} as grain size increases form 40 to over 100 {mu}m in individual samples. The appearance of native sulfur is accompanied by an increase of up to 30{per_thousand} in pyrite {sigma}{sup 34}S values. Bulk and ion probe analyses of anhydrite are relatively uniform ({sigma}{sup 34}S = +22 to +30{per_thousand} CDT). The predominately low {sigma}{sup 34}S values of Nisku sulfides indicate bacterial sulfate reduction. Textural relations indicate that Fe-sulfide formation in Nisku carbonates may have occurred by two different mechanisms. Much of the sulfide has {sigma}{sup 34}S values that suggest that it was associated with bacterial sulfate reduction, although most Fe-sulfides did not form until after pervasive matrix dolomitization (depths of 300-1000 m). Other sulfide may have formed later, during deep ({approximately}4km) burial via thermochemical sulfate reduction. The range in {sigma}{sup 34}S values in a single thin section and correlations between pyrite morphology and isotopic values suggest that sulfate reduction was a very localized process, and that the sulfate reduction environment varied considerably on a small scale. 61 refs., 10 figs., 1 tab.

  12. Analysis of statistical model properties from discrete nuclear structure data

    NASA Astrophysics Data System (ADS)

    Firestone, Richard B.

    2012-02-01

    Experimental M1, E1, and E2 photon strengths have been compiled from experimental data in the Evaluated Nuclear Structure Data File (ENSDF) and the Evaluated Gamma-ray Activation File (EGAF). Over 20,000 Weisskopf reduced transition probabilities were recovered from the ENSDF and EGAF databases. These transition strengths have been analyzed for their dependence on transition energies, initial and final level energies, spin/parity dependence, and nuclear deformation. ENSDF BE1W values were found to increase exponentially with energy, possibly consistent with the Axel-Brink hypothesis, although considerable excess strength observed for transitions between 4-8 MeV. No similar energy dependence was observed in EGAF or ARC data. BM1W average values were nearly constant at all energies above 1 MeV with substantial excess strength below 1 MeV and between 4-8 MeV. BE2W values decreased exponentially by a factor of 1000 from 0 to 16 MeV. The distribution of ENSDF transition probabilities for all multipolarities could be described by a lognormal statistical distribution. BE1W, BM1W, and BE2W strengths all increased substantially for initial transition level energies between 4-8 MeV possibly due to dominance of spin-flip and Pygmy resonance transitions at those excitations. Analysis of the average resonance capture data indicated no transition probability dependence on final level spins or energies between 0-3 MeV. The comparison of favored to unfavored transition probabilities for odd-A or odd-Z targets indicated only partial support for the expected branching intensity ratios with many unfavored transitions having nearly the same strength as favored ones. Average resonance capture BE2W transition strengths generally increased with greater deformation. Analysis of ARC data suggest that there is a large E2 admixture in M1 transitions with the mixing ratio δ ≈ 1.0. The ENSDF reduced transition strengths were considerably stronger than those derived from capture gamma ray

  13. Monte-Carlo Application for Nondestructive Nuclear Waste Analysis

    NASA Astrophysics Data System (ADS)

    Carasco, C.; Engels, R.; Frank, M.; Furletov, S.; Furletova, J.; Genreith, C.; Havenith, A.; Kemmerling, G.; Kettler, J.; Krings, T.; Ma, J.-L.; Mauerhofer, E.; Neike, D.; Payan, E.; Perot, B.; Rossbach, M.; Schitthelm, O.; Schumann, M.; Vasquez, R.

    2014-06-01

    Radioactive waste has to undergo a process of quality checking in order to check its conformance with national regulations prior to its transport, intermediate storage and final disposal. Within the quality checking of radioactive waste packages non-destructive assays are required to characterize their radio-toxic and chemo-toxic contents. The Institute of Energy and Climate Research - Nuclear Waste Management and Reactor Safety of the Forschungszentrum Jülich develops in the framework of cooperation nondestructive analytical techniques for the routine characterization of radioactive waste packages at industrial-scale. During the phase of research and development Monte Carlo techniques are used to simulate the transport of particle, especially photons, electrons and neutrons, through matter and to obtain the response of detection systems. The radiological characterization of low and intermediate level radioactive waste drums is performed by segmented γ-scanning (SGS). To precisely and accurately reconstruct the isotope specific activity content in waste drums by SGS measurement, an innovative method called SGSreco was developed. The Geant4 code was used to simulate the response of the collimated detection system for waste drums with different activity and matrix configurations. These simulations allow a far more detailed optimization, validation and benchmark of SGSreco, since the construction of test drums covering a broad range of activity and matrix properties is time consuming and cost intensive. The MEDINA (Multi Element Detection based on Instrumental Neutron Activation) test facility was developed to identify and quantify non-radioactive elements and substances in radioactive waste drums. MEDINA is based on prompt and delayed gamma neutron activation analysis (P&DGNAA) using a 14 MeV neutron generator. MCNP simulations were carried out to study the response of the MEDINA facility in terms of gamma spectra, time dependence of the neutron energy spectrum

  14. Nuclear microbeam analysis of wear particles in tissue surrounding failed hip joint implants

    NASA Astrophysics Data System (ADS)

    Grime, G. W.; Triffitt, J. T.; Williamson, M. C.; Athanasou, N. A.

    1994-05-01

    Particulate wear debris from hip joint replacements is an important factor in determining the response of the surrounding tissue to the implants. Failed replacement joints are surrounded by a layer of fibrous tissue showing an inflammatory response to the wear debris. This reaction leads to bone resorption and the eventual failure of the prosthesis. In preliminary experiments the Oxford scanning proton microprobe has been used to study the composition of wear particles in the membranes surrounding failed implants constructed from Ti/V/Al alloy. The membranes were observed to contain 1-10 μm particles with major constituents from the alloy and also from the cement and polyethylene used in the fitting and construction of the implant. Histological staining shows that these particles are associated with areas of high macrophage activity. Individual PIXE analysis of the metal particles indicates that two populations (high Ti/low Al and low Ti/high Al) may be present. These observations will provide further information on the mechanisms of implant degradation.

  15. NUclear EVacuation Analysis Code (NUEVAC) : a tool for evaluation of sheltering and evacuation responses following urban nuclear detonations.

    SciTech Connect

    Yoshimura, Ann S.; Brandt, Larry D.

    2009-11-01

    The NUclear EVacuation Analysis Code (NUEVAC) has been developed by Sandia National Laboratories to support the analysis of shelter-evacuate (S-E) strategies following an urban nuclear detonation. This tool can model a range of behaviors, including complex evacuation timing and path selection, as well as various sheltering or mixed evacuation and sheltering strategies. The calculations are based on externally generated, high resolution fallout deposition and plume data. Scenario setup and calculation outputs make extensive use of graphics and interactive features. This software is designed primarily to produce quantitative evaluations of nuclear detonation response options. However, the outputs have also proven useful in the communication of technical insights concerning shelter-evacuate tradeoffs to urban planning or response personnel.

  16. Spherical tensor analysis of nuclear magnetic resonance signals.

    PubMed

    van Beek, Jacco D; Carravetta, Marina; Antonioli, Gian Carlo; Levitt, Malcolm H

    2005-06-22

    In a nuclear magnetic-resonance (NMR) experiment, the spin density operator may be regarded as a superposition of irreducible spherical tensor operators. Each of these spin operators evolves during the NMR experiment and may give rise to an NMR signal at a later time. The NMR signal at the end of a pulse sequence may, therefore, be regarded as a superposition of spherical components, each derived from a different spherical tensor operator. We describe an experimental method, called spherical tensor analysis (STA), which allows the complete resolution of the NMR signal into its individual spherical components. The method is demonstrated on a powder of a (13)C-labeled amino acid, exposed to a pulse sequence generating a double-quantum effective Hamiltonian. The propagation of spin order through the space of spherical tensor operators is revealed by the STA procedure, both in static and rotating solids. Possible applications of STA to the NMR of liquids, liquid crystals, and solids are discussed. PMID:16035785

  17. Sensitivity analysis and optimization of the nuclear fuel cycle

    SciTech Connect

    Passerini, S.; Kazimi, M. S.; Shwageraus, E.

    2012-07-01

    A sensitivity study has been conducted to assess the robustness of the conclusions presented in the MIT Fuel Cycle Study. The Once Through Cycle (OTC) is considered as the base-line case, while advanced technologies with fuel recycling characterize the alternative fuel cycles. The options include limited recycling in LWRs and full recycling in fast reactors and in high conversion LWRs. Fast reactor technologies studied include both oxide and metal fueled reactors. The analysis allowed optimization of the fast reactor conversion ratio with respect to desired fuel cycle performance characteristics. The following parameters were found to significantly affect the performance of recycling technologies and their penetration over time: Capacity Factors of the fuel cycle facilities, Spent Fuel Cooling Time, Thermal Reprocessing Introduction Date, and in core and Out-of-core TRU Inventory Requirements for recycling technology. An optimization scheme of the nuclear fuel cycle is proposed. Optimization criteria and metrics of interest for different stakeholders in the fuel cycle (economics, waste management, environmental impact, etc.) are utilized for two different optimization techniques (linear and stochastic). Preliminary results covering single and multi-variable and single and multi-objective optimization demonstrate the viability of the optimization scheme. (authors)

  18. Intelligent signal analysis methodologies for nuclear detection, identification and attribution

    NASA Astrophysics Data System (ADS)

    Alamaniotis, Miltiadis

    Detection and identification of special nuclear materials can be fully performed with a radiation detector-spectrometer. Due to several physical and computational limitations, development of fast and accurate radioisotope identifier (RIID) algorithms is essential for automated radioactive source detection and characterization. The challenge is to identify individual isotope signatures embedded in spectral signature aggregation. In addition, background and isotope spectra overlap to further complicate the signal analysis. These concerns are addressed, in this thesis, through a set of intelligent methodologies recognizing signature spectra, background spectrum and, subsequently, identifying radionuclides. Initially, a method for detection and extraction of signature patterns is accomplished by means of fuzzy logic. The fuzzy logic methodology is applied on three types of radiation signal processing applications, where it exhibits high positive detection, low false alarm rate and very short execution time, while outperforming the maximum likelihood fitting approach. In addition, an innovative Pareto optimal multiobjective fitting of gamma ray spectra using evolutionary computing is presented. The methodology exhibits perfect identification while performs better than single objective fitting. Lastly, an innovative kernel based machine learning methodology was developed for estimating natural background spectrum in gamma ray spectra. The novelty of the methodology lies in the fact that it implements a data based approach and does not require any explicit physics modeling. Results show that kernel based method adequately estimates the gamma background, but algorithm's performance exhibits a strong dependence on the selected kernel.

  19. Nuclear criticality safety calculational analysis for small-diameter containers

    SciTech Connect

    LeTellier, M.S.; Smallwood, D.J.; Henkel, J.A.

    1995-11-01

    This report documents calculations performed to establish a technical basis for the nuclear criticality safety of favorable geometry containers, sometimes referred to as 5-inch containers, in use at the Portsmouth Gaseous Diffusion Plant. A list of containers currently used in the plant is shown in Table 1.0-1. These containers are currently used throughout the plant with no mass limits. The use of containers with geometries or material types other than those addressed in this evaluation must be bounded by this analysis or have an additional analysis performed. The following five basic container geometries were modeled and bound all container geometries in Table 1.0-1: (1) 4.32-inch-diameter by 50-inch-high polyethylene bottle; (2) 5.0-inch-diameter by 24-inch-high polyethylene bottle; (3) 5.25-inch-diameter by 24-inch-high steel can ({open_quotes}F-can{close_quotes}); (4) 5.25-inch-diameter by 15-inch-high steel can ({open_quotes}Z-can{close_quotes}); and (5) 5.0-inch-diameter by 9-inch-high polybottle ({open_quotes}CO-4{close_quotes}). Each container type is evaluated using five basic reflection and interaction models that include single containers and multiple containers in normal and in credible abnormal conditions. The uranium materials evaluated are UO{sub 2}F{sub 2}+H{sub 2}O and UF{sub 4}+oil materials at 100% and 10% enrichments and U{sub 3}O{sub 8}, and H{sub 2}O at 100% enrichment. The design basis safe criticality limit for the Portsmouth facility is k{sub eff} + 2{sigma} < 0.95. The KENO study results may be used as the basis for evaluating general use of these containers in the plant.

  20. Nuclear Dynamics Consequence Analysis (NDCA) for the Disposal of Spent Nuclear Fuel in an Underground Geologic Repository - Volume 3: Appendices

    SciTech Connect

    Taylor, L.L.; Wilson, J.R.; Sanchez, L.C.; Aguilar, R.; Trellue, H.R.; Cochrane, K.; Rath, J.S.

    1998-10-01

    The United States Department of Energy Office of Environmental Management's (DOE/EM's) National Spent Nuclear Fuel Program (NSNFP), through a collaboration between Sandia National Laboratories (SNL) and Idaho National Engineering and Environmental Laboratory (INEEL), is conducting a systematic Nuclear Dynamics Consequence Analysis (NDCA) of the disposal of SNFs in an underground geologic repository sited in unsaturated tuff. This analysis is intended to provide interim guidance to the DOE for the management of the SNF while they prepare for final compliance evaluation. This report presents results from a Nuclear Dynamics Consequence Analysis (NDCA) that examined the potential consequences and risks of criticality during the long-term disposal of spent nuclear fuel owned by DOE-EM. This analysis investigated the potential of post-closure criticality, the consequences of a criticality excursion, and the probability frequency for post-closure criticality. The results of the NDCA are intended to provide the DOE-EM with a technical basis for measuring risk which can be used for screening arguments to eliminate post-closure criticality FEPs (features, events and processes) from consideration in the compliance assessment because of either low probability or low consequences. This report is composed of an executive summary (Volume 1), the methodology and results of the NDCA (Volume 2), and the applicable appendices (Volume 3).

  1. Ion microprobe studies of trace elements in Apollo 14 volcanic glass beads - Comparisons to Apollo 14 mare basalts and petrogenesis of picritic magmas

    NASA Technical Reports Server (NTRS)

    Shearer, C. K.; Papike, J. J.; Simon, S. B.; Shimizu, N.; Yurimoto, H.

    1990-01-01

    Results are presented from trace element analysis, by ion microprobe techniques, of individual glass beads representing seven compositionally distinct types of picritic glass beads from the Apollo 14 landing site. The picritic glass beads at the A-14 exhibited a wide range of primary magma compositions and a lack of petrogenetic linkage (via crystal fractionation) to crystalline basalts. The wide range of major and trace element characteristics of the picritic glass beads is consistent with derivation from mineralogically distinct sources which consist of varying proportions of olivine + orthopyroxene +/- clonopyroxene +/- ilmenite +/- plagioclase +/- KREEP component.

  2. Interviewing a Silent (Radioactive) Witness through Nuclear Forensic Analysis.

    PubMed

    Mayer, Klaus; Wallenius, Maria; Varga, Zsolt

    2015-12-01

    Nuclear forensics is a relatively young discipline in science which aims at providing information on nuclear material of unknown origin. The determination of characteristic parameters through tailored analytical techniques enables establishing linkages to the material's processing history and hence provides hints on its place and date of production and on the intended use. PMID:26376028

  3. Analysis constants for database of neutron nuclear data

    NASA Astrophysics Data System (ADS)

    Bedenko, S. V.; Jeremiah, J. Joseph; Knyshev, V. V.; Shamanin, I. V.

    2016-07-01

    At present there is a variety of experimental and calculation nuclear data which are rather entirely presented in the following evaluated nuclear data libraries: ENDF (USA), JEFF (Europe), JENDL (Japan), TENDL (Russian Federation), ROSFOND (Russian Federation). Libraries of nuclear data, used for neutron-physics calculations in programs: Scale (Origen-Arp), MCNP, WIMS, MCU, and others. Nevertheless all existing nuclear data bases, including evaluated ones, contain practically no information about threshold neutron reactions on 232Th nuclei; available values of outputs and cross-sections significantly differ by orders. The work shows necessity of nuclear constants corrections which are used in the calculations of grids and thorium storage systems. The results of numerical experiments lattices and storage systems with thorium.

  4. Style, content and format guide for writing safety analysis documents. Volume 1, Safety analysis reports for DOE nuclear facilities

    SciTech Connect

    Not Available

    1994-06-01

    The purpose of Volume 1 of this 4-volume style guide is to furnish guidelines on writing and publishing Safety Analysis Reports (SARs) for DOE nuclear facilities at Sandia National Laboratories. The scope of Volume 1 encompasses not only the general guidelines for writing and publishing, but also the prescribed topics/appendices contents along with examples from typical SARs for DOE nuclear facilities.

  5. CONCH: A Visual Basic program for interactive processing of ion-microprobe analytical data

    NASA Astrophysics Data System (ADS)

    Nelson, David R.

    2006-11-01

    A Visual Basic program for flexible, interactive processing of ion-microprobe data acquired for quantitative trace element, 26Al- 26Mg, 53Mn- 53Cr, 60Fe- 60Ni and U-Th-Pb geochronology applications is described. Default but editable run-tables enable software identification of secondary ion species analyzed and for characterization of the standard used. Counts obtained for each species may be displayed in plots against analysis time and edited interactively. Count outliers can be automatically identified via a set of editable count-rejection criteria and displayed for assessment. Standard analyses are distinguished from Unknowns by matching of the analysis label with a string specified in the Set-up dialog, and processed separately. A generalized routine writes background-corrected count rates, ratios and uncertainties, plus weighted means and uncertainties for Standards and Unknowns, to a spreadsheet that may be saved as a text-delimited file. Specialized routines process trace-element concentration, 26Al- 26Mg, 53Mn- 53Cr, 60Fe- 60Ni, and Th-U disequilibrium analysis types, and U-Th-Pb isotopic data obtained for zircon, titanite, perovskite, monazite, xenotime and baddeleyite. Correction to measured Pb-isotopic, Pb/U and Pb/Th ratios for the presence of common Pb may be made using measured 204Pb counts, or the 207Pb or 208Pb counts following subtraction from these of the radiogenic component. Common-Pb corrections may be made automatically, using a (user-specified) common-Pb isotopic composition appropriate for that on the sample surface, or for that incorporated within the mineral at the time of its crystallization, depending on whether the 204Pb count rate determined for the Unknown is substantially higher than the average 204Pb count rate for all session standards. Pb/U inter-element fractionation corrections are determined using an interactive log e-log e plot of common-Pb corrected 206Pb/ 238U ratios against any nominated fractionation-sensitive species pair

  6. Dynamic Systems Analysis Report for Nuclear Fuel Recycle

    SciTech Connect

    Brent Dixon; Sonny Kim; David Shropshire; Steven Piet; Gretchen Matthern; Bill Halsey

    2008-12-01

    This report examines the time-dependent dynamics of transitioning from the current United States (U.S.) nuclear fuel cycle where used nuclear fuel is disposed in a repository to a closed fuel cycle where the used fuel is recycled and only fission products and waste are disposed. The report is intended to help inform policy developers, decision makers, and program managers of system-level options and constraints as they guide the formulation and implementation of advanced fuel cycle development and demonstration efforts and move toward deployment of nuclear fuel recycling infrastructure.

  7. Nuclear and radiochemical techniques in chemical analysis. Final report

    SciTech Connect

    Finston, H.L.; Williams, E.T.

    1981-06-01

    The areas studied during the period of the contract included determinations of cross sections for nuclear reactions, determination of neutron capture cross sections of radionuclides, application of special activation techniques, and x-ray counting, elucidation of synergic solvent extraction mechanisms and development of new solvent extraction techniques, and the development of a PIXE analytical facility. The thermal neutron capture cross section of /sup 22/Na was determined, and cross sections and energy levels were determined for /sup 20/Ne(n,..cap alpha..)/sup 17/O, /sup 20/Ne(n,P)/sup 20/F, and /sup 40/Ar(n,..cap alpha..)/sup 37/S. Inelastic scattering with 2 to 3 MeV neutrons followed by counting of the metastable states permits analysis of the following elements: In, Sr, Cd, Hg, and Pb. Bromine can be detected in the presence of a 500-fold excess of Na and/or K by thermal neutron activation and x-ray counting, and as little as 0.3 x 10/sup -9/ g of Hg can be detected by this technique. Mediun energy neutrons (10 to 160 MeV) have been used to determine Tl, Pb, and Bi by (n,Xn) and (n,PXn) reactions. The reaction /sup 19/F(P,..cap alpha..)/sup 76/O has been used to determine as little as 50 ..mu..mol of Freon -14. Mechanisms for synergic solvent extractions have been elucidated and a new technique of homogeneous liquid-liquid solvent extraction has been developed in which the neutral complex is rapidly extracted propylene carbonate by raising and lowering the temperature of the system. An external-beam PIXE system has been developed for trace element analyses of a variety of sample types. Various sample preparation techniques have been applied to a diverse range of samples including marine sediment, coral, coal, and blood.

  8. Risk analysis and solving the nuclear waste siting problem

    SciTech Connect

    Inhaber, H.

    1993-12-01

    In spite of millions of dollars and countless human resources being expended on finding nuclear wastes sites, the search has proved extremely difficult for the nuclear industry. This may be due to the approach followed, rather than inadequacies in research or funding. A new approach to the problem, the reverse Dutch auction, is suggested. It retains some of the useful elements of the present system, but it also adds new ones.

  9. Providing Nuclear Criticality Safety Analysis Education through Benchmark Experiment Evaluation

    SciTech Connect

    John D. Bess; J. Blair Briggs; David W. Nigg

    2009-11-01

    One of the challenges that today's new workforce of nuclear criticality safety engineers face is the opportunity to provide assessment of nuclear systems and establish safety guidelines without having received significant experience or hands-on training prior to graduation. Participation in the International Criticality Safety Benchmark Evaluation Project (ICSBEP) and/or the International Reactor Physics Experiment Evaluation Project (IRPhEP) provides students and young professionals the opportunity to gain experience and enhance critical engineering skills.

  10. 78 FR 56869 - Nuclear Infrastructure Programmatic Environmental Impact Statement Supplement Analysis...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-16

    ...The Department of Energy (DOE) has completed the Supplement Analysis (SA) of the Programmatic Environmental Impact Statement for Accomplishing Expanded Civilian Nuclear Energy Research and Development and Isotope Production Missions in the United States, Including the Role of the Fast Flux Test Facility (Nuclear Infrastructure or NI PEIS) (DOE/EIS-0310) published in December 2000. In......

  11. Determination of nitrogen in coal macerals using electron microprobe technique-experimental procedure

    USGS Publications Warehouse

    Mastalerz, Maria; Gurba, L.W.

    2001-01-01

    This paper discusses nitrogen determination with the Cameca SX50 electron microprobe using PCO as an analyzing crystal. A set of conditions using differing accelerating voltages, beam currents, beam sizes, and counting times were tested to determine parameters that would give the most reliable nitrogen determination. The results suggest that, for the instrumentation used, 10 kV, current 20 nA, and a counting time of 20 s provides the most reliable nitrogen determination, with a much lower detection limit than the typical concentration of this element in coal. The study demonstrates that the electron microprobe technique can be used to determine the nitrogen content of coal macerals successfully and accurately. ?? 2001 Elsevier Science B.V. All rights reserved.

  12. Application of a nuclear microprobe to the study of fish otoliths and scales

    NASA Astrophysics Data System (ADS)

    Coote, G. E.; Gauldie, R. W.; West, I. F.

    1991-03-01

    We have measured the distributions of some of the elements in otoliths and scales from several species of teleost (bony) fish, with the aim of learning more about the environment of a fish at different stages in its life, and testing the validity of present methods for determining the age of a fish. The ratio of strontium to calcium in successive layers of an otolith is extremely sensitive to water temperature, so it is possible to trace the temperature history of the fish, probably including seasonal variations. The distributions of calcium and fluorine in scales differ strikingly between species and sufficiently in a single scale to suggest that environmental information may be captured there as well.

  13. Investigation of UO 2 leaching behaviour in groundwater using a nuclear microprobe: preliminary results

    NASA Astrophysics Data System (ADS)

    Trocellier, Patrick; Gallien, Jean Paul

    1994-08-01

    Rutherford backscattering spectrometry with a 1.5 MeV 4He + microbeam was used to quantify the variation of the surface composition of sintered UO 2 pellets submitted to groundwater corrosion in oxidizing conditions. μRBS data indicate the transformation of UO 2 both into higher oxides such as U 4O 9, U 3O 7, U 2O 5 and U 3O 8 and into hydrated and/or carbonated species. Comparison of these results with millibeam RBS and NRA experiments, scanning electron microscopy observations and calculations using the thermodynamics geocode PHREEQE suggests an oxidation/dissolution phenomenon controlled by precipitation of uranium insoluble compounds such as βUO 2(OH) 2, rutherfordine, βUO 3 or CaUO 4.

  14. Ion Microprobe Analyses of Rare Earth Elements in an Extremely Ultrarefractory Nodule from the Efremovka CV3 Chondrite

    NASA Astrophysics Data System (ADS)

    Uchiyama, K.; Hiyagon, H.; Takahata, N.; Sano, Y.; Ushikubo, T.; Kimura, M.; Hashimoto, A.

    2008-03-01

    REE abundance patterns of an extremely ultrarefractory nodule "Himiko" and its host inclusion "EFG-1" obtained using NanoSIMS and ims-6f ion microprobes, respectively, are presented and their formation conditions are discussed.

  15. Review of Overall Safety Manual for space nuclear systems. An evaluation of a nuclear safety analysis methodology for plutonium-fueled space nuclear systems

    SciTech Connect

    Coleman, J.; Inhaber, H.

    1984-02-01

    As part of its duties in connection with space missions involving nuclear power sources, the Office of Nuclear Safety (ONS) of the Office of Assistant Secretary for Environmental Protection, Safety, and Emergency Preparedness has been assigned the task of reviewing the Overall Safety Manual (OSM) (memo from B.J. Rock to J.R. Maher, December 1, 1982). The OSM, dated July 1981 and in four volumes, was prepared by NUS Corporation, Rockville, Maryland, for the US Department of Energy. The OSM provides many of the technical models and much of the data which are used by (1) space launch contractors in safety analysis reports and (2) the broader Interagency Nuclear Safety Review Panel (INSRP) safety evaluation reports. If fhs interaction between the OSM, contractors, and INSRP is to work effectively, the OSM must be accurate, comprehensive, understandable, and usable.

  16. Analysis of nuclear proliferation resistance reprocessing and recycling technologies

    SciTech Connect

    Patricia Paviet-Hartmann; Gary Cerefice; Marcela Stacey; Steven Bakhtiar

    2011-05-01

    The PUREX process has been progressively and continuously improved during the past three decades, and these improvements account for successful commercialization of reprocessing in a few countries. The renewed interest in nuclear energy and the international growth of nuclear electricity generation do not equate – and should not be equated -with increasing proliferation risks. Indeed, the nuclear renaissance presents a unique opportunity to enhance the culture of non-proliferation. With the recent revival of interest in nuclear technology, technical methods for prevention of nuclear proliferation are being revisited. Robust strategies to develop new advanced separation technologies are emerging worldwide for sustainability and advancement of nuclear energy with enhanced proliferation resistance. On the other hand, at this moment, there are no proliferation resistance advanced technologies. . Until now proliferation resistance as it applies to reprocessing has been focused on not separating a pure stream of weapons-usable plutonium. France, as an example, has proposed a variant of the PUREX process, the COEX TM process, which does not result on a pure plutonium product stream. A further step is to implement a process based on group extraction of actinides and fission products associated with a homogeneous recycling strategy (UNEX process in the US, GANEX process in France). Such scheme will most likely not be deployable on an industrial scale before 2030 or so because it requires intensive R&D and robust flowsheets. Finally, future generation recycling schemes will handle the used nuclear fuel in fast neutron reactors. This means that the plutonium throughput of the recycling process may increase. The need is obvious for advanced aqueous recycling technologies that are intrinsically more proliferation resistant than the commercial PUREX process. In this paper, we review the actual PUREX process along with the advanced recycling technologies that will enhance

  17. Trace Element Zoning and Incipient Metamictization in a Lunar Zircon: Application of Three Microprobe Techniques

    NASA Technical Reports Server (NTRS)

    Wopenka, Brigitte; Jollife, Bradley L.; Zinner, Ernst; Kremser, Daniel T.

    1996-01-01

    We have determined major (Si, Zr, Hf), minor (Al, Y, Fe, P), and trace element (Ca, Sc, Ti, Ba, REE, Th, U) concentrations and Raman spectra of a zoned, 200 microns zircon grain in lunar sample 14161,7069, a quartz monzodiorite breccia collected at the Apollo 14 site. Analyses were obtained on a thin section in situ with an ion microprobe, an electron microprobe, and a laser Raman microprobe. The zircon grain is optically zoned in birefringence, a reflection of variable (incomplete) metamictization resulting from zo- nation in U and Th concentrations. Variations in the concentrations of U and Th correlate strongly with those of other high-field-strength trace elements and with changes in Raman spectral parameters. Concentrations of U and Th range from 21 to 55 ppm and 6 to 31 ppm, respectively, and correlate with lower Raman peak intensities, wider Raman peaks, and shifted Si-O peak positions. Concentrations of heavy rare earth elements range over a factor of three to four and correlate with intensities of fluorescence peaks. Correlated variations in trace element concentrations reflect the original magmatic differentiation of the parental melt approx. 4 b.y. ago. Degradation of the zircon structure, as reflected by the observed Raman spectral parameters, has occurred in this sample over a range of alpha-decay event dose from approx. 5.2 x 10(exp 14) to 1.4 x 10(exp 15) decay events per milligram of zircon, as calculated from the U and Th concentrations. This dose is well below the approx. 10(exp 16) events per milligram cumulative dose that causes complete metamictization and indicates that laser Raman microprobe spectroscopy is an analytical technique that is very sensitive to the radiation-induced damage in zircon.

  18. Commissioning of a microprobe-XRF beamline (BL-16) on Indus-2 synchrotron source

    SciTech Connect

    Tiwari, M. K.; Gupta, P.; Sinha, A. K.; Garg, C. K.; Singh, A. K.; Kane, S. R.; Garg, S. R.; Lodha, G. S.

    2012-06-05

    We report commissioning of the microprobe-XRF beamline on Indus-2 synchrotron source. The beamline has been recently made operational and is now open for the user's experiments. The beamline comprises of Si(111) double crystal monochromator and Kirkpatrick-Baez focusing optics. The beamline covers wide photon energy range of 4 - 20 keV using both collimated and micro-focused beam modes. The design details and the first commissioning results obtained using this beamline are presented.

  19. Multicolor in vivo brain imaging with a microscope-coupled fiber-bundle microprobe

    NASA Astrophysics Data System (ADS)

    Doronina-Amitonova, Lyubov V.; Fedotov, Il'ya V.; Efimova, Olga; Chernysheva, Maria; Fedotov, Andrei B.; Anokhin, Konstantin V.; Zheltikov, Aleksei M.

    2012-12-01

    A fiber-bundle microprobe coupled to a confocal optical microscope is shown to enable multicolor in vivo fluorescence brain imaging. A bundle of several thousands of 2.4-μm-diameter optical fibers is employed to deliver multiwavelength laser excitation radiation and to transmit multicolor images from hippocampus tissues in living transgenic mice by picking up a multiplex fluorescent response from green fluorescent protein, nucleic acid counterstains, and neuron tracers.

  20. Applications of synchrotron x-ray fluorescence microprobe techniques to photochromic materials

    SciTech Connect

    Perry, D.L.

    1996-12-31

    Applications of synchrotron x-ray fluorescence microprobe techniques to photochromic materials are presented regarding dopant metal ions in the crystal matrices. Types of samples that are amenable to the technique will be discussed, along with sample format and experimental conditions. The chemical information that one can obtain from samples will be presented, and examples of copant contaminant studies in crystals will be given. New types of samples that are possible to study using this technique will be presented.

  1. DSMC Simulations of Blunt Body Flows for Mars Entries: Mars Pathfinder and Mars Microprobe Capsules

    NASA Technical Reports Server (NTRS)

    Moss, James N.; Wilmoth, Richard G.; Price, Joseph M.

    1997-01-01

    The hypersonic transitional flow aerodynamics of the Mars Pathfinder and Mars Microprobe capsules are simulated with the direct simulation Monte Carlo method. Calculations of axial, normal, and static pitching coefficients were obtained over an angle of attack range comparable to actual flight requirements. Comparisons are made with modified Newtonian and free-molecular-flow calculations. Aerothermal results were also obtained for zero incidence entry conditions.

  2. Stress measurements in silicon substrates with TiSi2 patterns using Raman microprobe

    NASA Astrophysics Data System (ADS)

    Ito, Tadashi; Azuma, Hirozumi; Noda, Shoji

    1994-01-01

    The horizontal and depth distributions of the stress induced in silicon substrates with titanium silicide TiSi2 patterns were evaluated using the Raman microprobe. Tensile stress is generated besides the TiSi2 pattern. The tensile stres s reaches a maximum value of 150-350 MPa at the distance of approximately = 0.5 micron from the edge of the TiSi2 pattern.

  3. Library of sophisticated functions for analysis of nuclear spectra

    NASA Astrophysics Data System (ADS)

    Morháč, Miroslav; Matoušek, Vladislav

    2009-10-01

    In the paper we present compact library for analysis of nuclear spectra. The library consists of sophisticated functions for background elimination, smoothing, peak searching, deconvolution, and peak fitting. The functions can process one- and two-dimensional spectra. The software described in the paper comprises a number of conventional as well as newly developed methods needed to analyze experimental data. Program summaryProgram title: SpecAnalysLib 1.1 Catalogue identifier: AEDZ_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEDZ_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 42 154 No. of bytes in distributed program, including test data, etc.: 2 379 437 Distribution format: tar.gz Programming language: C++ Computer: Pentium 3 PC 2.4 GHz or higher, Borland C++ Builder v. 6. A precompiled Windows version is included in the distribution package Operating system: Windows 32 bit versions RAM: 10 MB Word size: 32 bits Classification: 17.6 Nature of problem: The demand for advanced highly effective experimental data analysis functions is enormous. The library package represents one approach to give the physicists the possibility to use the advanced routines simply by calling them from their own programs. SpecAnalysLib is a collection of functions for analysis of one- and two-parameter γ-ray spectra, but they can be used for other types of data as well. The library consists of sophisticated functions for background elimination, smoothing, peak searching, deconvolution, and peak fitting. Solution method: The algorithms of background estimation are based on Sensitive Non-linear Iterative Peak (SNIP) clipping algorithm. The smoothing algorithms are based on the convolution of the original data with several types of filters and algorithms based on discrete

  4. ANALYSIS OF THE 'SPODOPTERA FRUGIPERDA' NUCLEAR POLYHEDROSIS VIRUS GENOME BY RESTRICTION ENDONUCLEASES AND ELECTRON MICROSCOPY

    EPA Science Inventory

    Restriction endonuclease analysis was used to differentiate between four strains of Spodoptera frugiperda nuclear polyhedrosis virus from different geographical areas. In addition, partial denaturation was performed, and a partial denaturation map was constructed for the Ohio str...

  5. Comparative analysis of dosimetry parameters for nuclear medicine

    SciTech Connect

    Toohey, R.E.; Stabin, M.G.

    1999-01-01

    For years many have employed the concept of ``total-body dose`` or ``whole-body dose,`` i.e., the total energy deposited in the body divided by the mass of the body, when evaluating the risks of different nuclear medicine procedures. The effective dose equivalent (H{sub E}), first described in ICRP Publication 26, has been accepted by some as a better quantity to use in evaluating the total risk of a procedure, but its use has been criticized by others primarily because the tissue weighting factors were intended for use in the radiation worker, rather than the nuclear medicine patient population. Nevertheless, in ICRP Publication 52, the ICRP has suggested that the H{sub E} may be used in nuclear medicine. The ICRP also has published a compendium of dose estimates, including H{sub E} values, for various nuclear medicine procedures at various ages in ICRP Publication 53. The effective dose (E) of ICRP Publication 60 is perhaps more suitable for use in nuclear medicine, with tissue weighting factors based on the entire population. Other comparisons of H{sub E} and E have been published. The authors have used the program MIRDOSE 3.1 to compute total-body dose, H{sub E}, and E for 62 radiopharmaceutical procedures, based on the best current biokinetic data available.

  6. A microprobe for parallel optical and electrical recordings from single neurons in vivo.

    PubMed

    LeChasseur, Yoan; Dufour, Suzie; Lavertu, Guillaume; Bories, Cyril; Deschênes, Martin; Vallée, Réal; De Koninck, Yves

    2011-04-01

    Recording electrical activity from identified neurons in intact tissue is key to understanding their role in information processing. Recent fluorescence labeling techniques have opened new possibilities to combine electrophysiological recording with optical detection of individual neurons deep in brain tissue. For this purpose we developed dual-core fiberoptics-based microprobes, with an optical core to locally excite and collect fluorescence, and an electrolyte-filled hollow core for extracellular single unit electrophysiology. This design provides microprobes with tips < 10 μm, enabling analyses with single-cell optical resolution. We demonstrate combined electrical and optical detection of single fluorescent neurons in rats and mice. We combined electrical recordings and optical Ca²(+) measurements from single thalamic relay neurons in rats, and achieved detection and activation of single channelrhodopsin-expressing neurons in Thy1::ChR2-YFP transgenic mice. The microprobe expands possibilities for in vivo electrophysiological recording, providing parallel access to single-cell optical monitoring and control. PMID:21317908

  7. ``STANDARD LIBRARY'': A relational database for the management of electron microprobe standards

    NASA Astrophysics Data System (ADS)

    Diamond, Larryn W.; Schmatz, Dirk; Würsten, Felix

    1994-05-01

    Laboratory collections of well-characterized solid materials are an indispensable basis for the calibration of quantitative electron microprobe analyses. The STANDARD LIBRARY database has been designed to manage the wide variety of information needed to characterize such standards, and to provide a rapid way by which these data can be accessed. In addition to physical storage information, STANDARD LIBRARY includes a full set of chemical and mineralogic characterization variables, and a set of variables specific to microprobe calibration (instrumental setup, standard homogeneity, etc.). Application programs for STANDARD LIBRARY provide a series of interactive screen views for database search, retrieval, and editing operations (including inventories). Search and inventory results can be written as UNIX data files, some of which are formatted to be read directly by the software that controls CAMECA SX50™ electron microprobes. The application programs are coded in OSL for the INGRES™ database-management system, and run within any environment that supports INGRES™ (e.g. UNIX, VMS, DOS, etc.). STANDARD LIBRARY has been generalized, however, such that only the physical storage structure of the database is dependent on the selected database-management system.

  8. The Mars Microprobe Mission: Advanced Micro-Avionics for Exploration Surface

    NASA Technical Reports Server (NTRS)

    Blue, Randel

    2000-01-01

    The Mars Microprobe Mission is the second spacecraft developed as part of the New Millennium Program deep space missions. The objective of the Microprobe Project is to demonstrate the applicability of key technologies for future planetary missions by developing two probes for deployment on Mars. The probes are designed with a single stage entry, descent, and landing system and impact the Martian surface at speeds of approximately 200 meters per second. The microprobes are composed of two main sections, a forebody section that penetrates to a depth below the Martian surface of 0.5 to 2 meters, and an aftbody section that remains on the surface. Each probe system consists of a number of advanced technology components developed specifically for this mission. These include a non-erosive aeroshell for entry into. the atmosphere, a set of low temperature batteries to supply probe power, an advanced microcontroller to execute the mission sequence, collect the science data, and react to possible system fault conditions, a telecommunications subsystem implemented on a set of custom integrated circuits, and instruments designed to provide science measurements from above and below the Martian surface. All of the electronic components have been designed and fabricated to withstand the severe impact shock environment and to operate correctly at predicted temperatures below -100 C.

  9. A liquid metal ion source in a high energy microprobe setup

    NASA Astrophysics Data System (ADS)

    Adamczewski, J.; Stephan, A.; Meijer, J.; Becker, H. W.; Bukow, H. H.; Rolfs, C.

    1999-10-01

    We describe first experiments with a new arrangement of the Bochum superconducting solenoid microprobe using a single ended electrostatic accelerator and the implementation of a high brightness Ga liquid metal ion source. In this setup the accelerator and the microprobe components are mounted on a common optical bench which is mechanically decoupled from the laboratory building via a separate basement. Care had to be taken of the ion optical adaptation of the source to the accelerator tube in order to preserve the source brightness in the entire experimental setup. The emittance characteristic of the Ga ion beam was determined directly at the location of the microprobe via automatic emittance scanning using the computer controlled slit system of the setup. By this means the parameters of the unfocused beam could be measured for both the accelerated case (315 keV) and the unaccelerated case (30 keV). It could be shown that the observed brightness of the source behind the extraction optics is about three orders of magnitude less than values quoted in the literature (˜10 6 A m -2 rad -2 eV -1) which were deduced from the virtual source size and the angular current density of the ion beam at the source tip. The parameters of the focused beam are presented.

  10. Experimental study on the mechanical interaction between silicon neural microprobes and rat dura mater during insertion.

    PubMed

    Fekete, Z; Németh, A; Márton, G; Ulbert, I; Pongrácz, A

    2015-02-01

    In vivo insertion experiments are essential to optimize novel neural implants. Our work focuses on the interaction between intact dura mater of rats and as-fabricated single-shaft silicon microprobes realized by deep reactive ion etching. Implantation parameters like penetration force and dimpling through intact dura mater were studied as a function of insertion speed, microprobe cross-section, tip angle and animal age. To reduce tissue resistance, we proposed a unique tip sharpening technique, which was also evaluated in in vivo insertion tests. By doubling the insertion speed (between 1.2 and 10.5 mm/min), an increase of 10-35% in penetration forces was measured. When decreasing the cross-section of the microprobes, penetration forces and dimpling was reduced by as much as 30-50% at constant insertion speeds. Force was noticed to gradually decrease by decreasing tip angles. Measured penetration forces through dura mater were reduced even down to 11±3 mN compared to unsharpened (49±13 mN) probes by utilizing our unique tip sharpening technique, which is very close to exerted penetration force in the case of retracted dura (5±1.5 mN). Our findings imply that age remarkably alters the elasticity of intact dura mater. The decreasing stiffness of dura mater results in a significant rise in penetration force and decrease in dimpling. Our work is the first in vivo comparative study on microelectrode penetration through intact and retracted dura mater. PMID:25631267

  11. The use of the laser Raman microprobe for the determination of salinity in fluid inclusions

    SciTech Connect

    Mernagh, T.P.; Wilde, A.R. )

    1989-04-01

    The O-H stretching region (2,800-3,800 cm{sup {minus}1}) in Raman spectra of aqueous solutions is sensitive to changes in the salt concentration. This permits determination of the salinity in the aqueous phase of fluid inclusions (at room temperature) by calculating skewing parameters from Raman microprobe spectra. The technique does not require detailed knowledge of the fluid composition and can be applied to most chloride solutions which commonly occur in fluid inclusions. Studies of synthetic fluid inclusions from the NaCl-H{sub 2}O system show that salinities up to halite saturation may be determined to within {plus minus}2 wt%. Well-characterized fluid inclusions from the unconformity-related uranium deposits of Nabarlek and Koongarra, Northern Territory, Australia, were studied with the laser Raman microprobe. The salinities determined from the Raman spectra are comparable to those obtained using standard microthermometric techniques. The Raman microprobe technique has the advantage of not requiring analogy to binary salt-water phase diagrams which cannot adequately model the complex brines in these inclusions. Variations in the concentration of salt hydrates, observed in Raman spectra of frozen inclusion, validated the salinities derived from the Raman skewing parameters obtained at room temperature. The Raman analyses confirm previous microthermometric evidence for trapping of discrete high and low salinity fluids.

  12. Nuclear stockpile stewardship and Bayesian image analysis (DARHT and the BIE)

    SciTech Connect

    Carroll, James L

    2011-01-11

    Since the end of nuclear testing, the reliability of our nation's nuclear weapon stockpile has been performed using sub-critical hydrodynamic testing. These tests involve some pretty 'extreme' radiography. We will be discussing the challenges and solutions to these problems provided by DARHT (the world's premiere hydrodynamic testing facility) and the BIE or Bayesian Inference Engine (a powerful radiography analysis software tool). We will discuss the application of Bayesian image analysis techniques to this important and difficult problem.

  13. Factorized molecular wave functions: Analysis of the nuclear factor

    SciTech Connect

    Lefebvre, R.

    2015-06-07

    The exact factorization of molecular wave functions leads to nuclear factors which should be nodeless functions. We reconsider the case of vibrational perturbations in a diatomic species, a situation usually treated by combining Born-Oppenheimer products. It was shown [R. Lefebvre, J. Chem. Phys. 142, 074106 (2015)] that it is possible to derive, from the solutions of coupled equations, the form of the factorized function. By increasing artificially the interstate coupling in the usual approach, the adiabatic regime can be reached, whereby the wave function can be reduced to a single product. The nuclear factor of this product is determined by the lowest of the two potentials obtained by diagonalization of the potential matrix. By comparison with the nuclear wave function of the factorized scheme, it is shown that by a simple rectification, an agreement is obtained between the modified nodeless function and that of the adiabatic scheme.

  14. Adapting Human Reliability Analysis from Nuclear Power to Oil and Gas Applications

    SciTech Connect

    Boring, Ronald Laurids

    2015-09-01

    ABSTRACT: Human reliability analysis (HRA), as currently used in risk assessments, largely derives its methods and guidance from application in the nuclear energy domain. While there are many similarities be-tween nuclear energy and other safety critical domains such as oil and gas, there remain clear differences. This paper provides an overview of HRA state of the practice in nuclear energy and then describes areas where refinements to the methods may be necessary to capture the operational context of oil and gas. Many key distinctions important to nuclear energy HRA such as Level 1 vs. Level 2 analysis may prove insignifi-cant for oil and gas applications. On the other hand, existing HRA methods may not be sensitive enough to factors like the extensive use of digital controls in oil and gas. This paper provides an overview of these con-siderations to assist in the adaptation of existing nuclear-centered HRA methods to the petroleum sector.

  15. A COMPARATIVE ANALYSIS BETWEEN FRANCE AND JAPAN ON LOCAL GOVERNMENTS' INVOLVEMENT IN NUCLEAR SAFETY GOVERNANCE

    NASA Astrophysics Data System (ADS)

    Sugawara, Shin-Etsu; Shiroyama, Hideaki

    This paper shows a comparative analysis between France and Japan on the way of the local governments' involvement in nuclear safety governance through some interviews. In France, a law came into force that requires related local governments to establish "Commision Locale d'Information" (CLI), which means the local governments officially involve in nuclear regulatory activity. Meanwhile, in Japan, related local governments substantially involve in the operation of nuclear facilities through the "safety agreements" in spite of the lack of legal authority. As a result of comparative analysis, we can point out some institutional input from French cases as follows: to clarify the local governments' roles in the nuclear regulation system, to establish the official channels of communication among nuclear utilities, national regulatory authorities and local governments, and to stipulate explicitly the transparency as a purpose of safety regulation.

  16. Analysis of nuclear quantum effects on hydrogen bonding.

    PubMed

    Swalina, Chet; Wang, Qian; Chakraborty, Arindam; Hammes-Schiffer, Sharon

    2007-03-22

    The impact of nuclear quantum effects on hydrogen bonding is investigated for a series of hydrogen fluoride (HF)n clusters and a partially solvated fluoride anion, F-(H2O). The nuclear quantum effects are included using the path integral formalism in conjunction with the Car-Parrinello molecular dynamics (PICPMD) method and using the second-order vibrational perturbation theory (VPT2) approach. For the HF clusters, a directional change in the impact of nuclear quantum effects on the hydrogen-bonding strength is observed as the clusters evolve toward the condensed phase. Specifically, the inclusion of nuclear quantum effects increases the F-F distances for the (HF)n=2-4 clusters and decreases the F-F distances for the (HF)n>4 clusters. This directional change occurs because the enhanced electrostatic interactions between the HF monomers become more dominant than the zero point energy effects of librational modes as the size of the HF clusters increases. For the F-(H2O) system, the inclusion of nuclear quantum effects decreases the F-O distance and strengthens the hydrogen bonding interaction between the fluoride anion and the water molecule because of enhanced electrostatic interactions. The vibrationally averaged 19F shielding constant for F-(H2O) is significantly lower than the value for the equilibrium geometry, indicating that the electronic density on the fluorine decreases as a result of the quantum delocalization of the shared hydrogen. Deuteration of this system leads to an increase in the vibrationally averaged F-O distance and nuclear magnetic shielding constant because of the smaller degree of quantum delocalization for deuterium. PMID:17388289

  17. X-ray Mapping of Terrestrial and Extraterrestrial Materials Using the Electron Microprobe

    NASA Technical Reports Server (NTRS)

    Carpenter, P.

    2006-01-01

    Lunar samples returned from the Apollo program motivated development of the Bence-Albee algorithm for the rapid and accurate analysis of lunar materials, and established interlaboratory comparability through its common use. In the analysis of mineral and rock fragments it became necessary to combine micro- and macroscopic analysis by coupling electron-probe microanalysis (EPMA) with automated stage point counting. A coarse grid that included several thousand points was used, and initially wavelength-dispersive (WDS) and later energydispersive (EDS) data were acquired at discrete stage points using approx. 5 sec count times. A approx 50 micrometer beam diameter was used for WDS and up to 500 micrometer beam diameter for EDS analysis. Average analyses of discretely sampled phases were coupled with the point count data to calculate the bulk composition using matrix algebra. Use of a defocused beam resulted in a contribution from multiple phases to each analytical point, and the analytical data were deconvolved relative to end-member phase chemistry on the fly. Impressive agreement was obtained between WDS and EDS measurements as well as comparison with bulk chemistry obtained by other methods. In the 30 years since these methods were developed, significant improvements in EPMA automation and computer processing have taken place. Digital beam control allows routine collection of x-ray maps by EDS, and stage mapping for WDS is conducted continuously at slew speed and incrementally by sampling at discrete points. Digital pulse processing in EDS systems has significantly increased the throughput for EDS mapping, and the ongoing development of Si-drift detector systems promises mapping capabilities rivaling WDS systems. Spectrum imaging allows a data cube of EDS spectra to be acquired and sophisticated processing of the original data is possible using matrix algebra techniques. The study of lunar and meteoritic materials includes the need to conveniently: (1) Characterize

  18. Analysis of nuclear test TRINITY radiological and meteorological data

    SciTech Connect

    Quinn, V.E.

    1987-09-01

    This report describes the Weather Service Nuclear Support Office (WSNSO) analyses of the radiological and meteorological data collected for the TRINITY nuclear test. Inconsistencies in the radiological data and their resolution are discussed. The methods of normalizing the radiological data to a standard time and estimating fallout-arrival times are presented. The meteorological situations on event day and the following day are described. Comparisons of the WSNSO fallout analyses with analyses performed in the 1940s are presented. The radiological data used to derive the WSNSO 1987 fallout patterns are tabulated in appendices.

  19. Nuclear forensic analysis of a non-traditional actinide sample.

    PubMed

    Doyle, Jamie L; Kuhn, Kevin; Byerly, Benjamin; Colletti, Lisa; Fulwyler, James; Garduno, Katherine; Keller, Russell; Lujan, Elmer; Martinez, Alexander; Myers, Steve; Porterfield, Donivan; Spencer, Khalil; Stanley, Floyd; Townsend, Lisa; Thomas, Mariam; Walker, Laurie; Xu, Ning; Tandon, Lav

    2016-10-01

    Nuclear forensic publications, performance tests, and research and development efforts typically target the bulk global inventory of intentionally safeguarded materials, such as plutonium (Pu) and uranium (U). Other materials, such as neptunium (Np), pose a nuclear security risk as well. Trafficking leading to recovery of an interdicted Np sample is a realistic concern especially for materials originating in countries that reprocesses fuel. Using complementary forensic methods, potential signatures for an unknown Np oxide sample were investigated. Measurement results were assessed against published Np processes to present hypotheses as to the original intended use, method of production, and origin for this Np oxide. PMID:27474299

  20. Electron-microprobe study of chromitites associated with alpine ultramafic complexes and some genetic implications

    USGS Publications Warehouse

    Bird, M.L.

    1978-01-01

    Electron-microprobe and petrographic studies of alpine chromite deposits from around the world demonstrate that they are bimodal with respect to the chromic oxide content of their chromite. The two modes occur at 54 ? 4 and 37 ? 3 weight per cent chromic oxide corresponding to chromite designated as high-chromium and high-aluminum chromite respectively. The high-chromium chromite occurs exclusively with highly magnesian olivine (Fo92-97) and some interstitial diopside. The high-aluminum chromite is associated with more ferrous olivine (Fo88-92), diopside, enstatite, and feldspar. The plot of the mole ratios Cr/(Cr+Al+Fe3+) vs. Mg/(Mg+Fe2+) usually presented for alpine chromite is shown to have a high-chromium, high-iron to low-chromium, low-iron trend contrary to that shown by stratiform chromite. This trend is characteristic of alpine type chromite and is termed the alpine trend. However, a trend similar to that for startiform chromite is discernable on the graph for the high-chromium chromite data. This latter trend is well-developed at Red Mountain, Seldovia, Alaska. Analysis of the iron-magnesium distribution coefficient, Kd=(Fe/Mg)ol/(Fe/Mg)ch, between olivine and chromite shows that Kd for the high-chromium chromite from all ultramafic complexes has essentially the same constant value of .05 while the distribution coefficient for the high-aluminum chromite varies with composition of the chromite. These distribution coefficients are also characteristic of alpine-type chromites. The constant value for Kd for the high-chromium chromite and associated high-magnesium olivine in all alpine complexes suggests that they all crystallized under similar physico-chemical conditions. The two types of massive chromite and their associations of silicate minerals suggest the possibility of two populations with different origins. Recrystallization textures associated with the high-aluminum chromite together with field relationships between the gabbro and the chromite pods

  1. Dual fiber microprobe for mapping elemental distributions in biological cells

    DOEpatents

    Martin, Rodger C [Powell, TN; Martin, Madhavi Z [Powell, TN

    2007-07-31

    Laser-induced breakdown spectroscopy (LIBS) is applied on a microscale for in situ elemental analysis and spatial mapping in biological cells. A high power laser beam is focused onto a cell surface using a dual branching optical fiber probe for optical excitation of the cell constituents. Dual spectrometers and ICCD detectors capture the emission spectra from the excited cell(s). Repeated probing or repositioning of the laser beam with respect to the cell can provide 2-D or 3-D mapping of the cell.

  2. Integrated Laser Microprobe (U-Th)/He and U/Pb Dating of Titanite and Zircon

    NASA Astrophysics Data System (ADS)

    Horne, A.; Van Soest, M. C.; Hodges, K. V.; Tripathy-Lang, A.

    2014-12-01

    The application of laser technologies for high spatial resolution dating has proven to be an important advancement in (U-Th)/He thermochronology. Excimer laser microprobes have been used to successfully date high U+Th minerals and are an especially promising way to determine the distribution of (U-Th)/He zircon ages in detrital sedimentary samples. We have also found that another detrital mineral, titanite, may be amenable to this method as well. While titanite contains lower concentrations of parent isotopes than zircon, and consequently less radiogenic 4He, its typically larger grain size allows for these characteristics to be mitigated by the use of larger laser beam diameters during the ablation process. With the integrated use of ICPMS, an established method for U/Pb geochronology, this phase of the laser microprobe (U-Th)/He technique can be modified slightly to enable (U-Th)/He and U/Pb 'double' dating of detrital samples. Here we present a proof of concept study demonstrating the viability of integrated laser microprobe (U-Th)/He and U/Pb through dating Oligocene Fish Canyon tuff titanite and zircon from Colorado. Our use of a well characterized sample with established (U-Th)/He and U/Pb dates allows us to fully evaluate the utility of this technique. By selecting medium- to fine-grained crystals we are able to simulate a realistic, uni-modal detrital sample. Using our modified laser microprobe approach, we are able to reproduce the expected age modes with an analytical imprecision roughly twice that of more established methods, a difference that has little practical effect on geologic interpretations. Additionally, we believe that the technique could prove a viable method for double dating detrital rutile and apatite, so long as characteristically lower U+Th concentrations in these minerals are balanced by appropriately scaled ablation pits in an aliquot unbiased by the need for larger detrital grains. Ultimately, integrated laser microprobe U/Pb and (U

  3. DEVELOPMENT OF NUCLEAR ANALYSIS CAPABILITIES FOR DOE WASTE MANAGEMENT ACTIVITIES

    EPA Science Inventory

    This research involves research and development in support of complementary technologies that are required to fulfill the anticipated needs of the DOE in its charter to safely provide for the management and ultimate disposition of nuclear facilities and materials. Specifically, t...

  4. Carbon analysis in CdTe by nuclear activation

    NASA Astrophysics Data System (ADS)

    Chibani, H.; Stoquert, J. P.; Hage-Ali, M.; Koebel, J. M.; Abdesselam, M.; Siffert, P.

    1991-06-01

    We describe the capabilities of the nuclear reaction 12C(d, n) 13Nlimit→β +13C the measurement of absolute concentrations of C in CdTe by the charged particle activation (CPA) method. This technique is used to determine the segregation coefficient of C introduced as an impurity in CdTe.

  5. Analysis of cross sections using various nuclear potential

    SciTech Connect

    Aziz, Azni Abdul; Kassim, Hasan Abu; Yusof, Norhasliza; Muhammad Zamrun, F.

    2014-05-02

    The relevant astrophysical reaction rates which are derived from the reaction cross sections are necessary input to the reaction network. In this work, we analyse several theoretical models of the nuclear potential which give better prediction of the cross sections for some selected reactions.

  6. The Analysis of North Korea's Nuclear Tests by Turkish National Data Center

    NASA Astrophysics Data System (ADS)

    Semin, K.; Meral Ozel, N.; Destici, T. C.; Necmioglu, O.; Kocak, S.

    2013-12-01

    The Democratic People's Republic of Korea (DPRK) announced the conduct of a third underground nuclear test on 12 February 2013 in the northeastern part of the country as the previous tests that were conducted in 2009 and 2006. The latest nuclear test is the best detected nuclear event by the global seismic networks. The magnitude estimates show that each new test increased in size when compared with the previous one. As Turkish NDC (National Data Center), we have analyzed the 2013 and 2009 nuclear tests using seismic data from International Monitoring System (IMS) stations through the International Data Center (IDC) located in Vienna. Discrimination analysis was performed based on mb:Ms magnitude ratio and spectral analysis. We have also applied array based waveform cross-correlation to show the similarity of the nuclear tests and precise arrival time measurements for relative location estimates and basic infrasound analysis using two IMS infrasound stations for the 2013 event. Seismic analysis were performed using softwares such as Geotool, EP (Event processor from Norsar) and Seismic Analysis Code (SAC) and the infrasound data were analyzed by using PMCC from CEA-France. The IMS network is operating under the Comprehensive Nuclear Test Ban Treaty Organization (CTBTO). The CTBTO verification system is under continuous development, also making use of the state of the art technologies and methodologies.

  7. [Quantitative Analysis of Immuno-fluorescence of Nuclear Factor-κB Activation].

    PubMed

    Xiu, Min; He, Feng; Lou, Yuanlei; Xu, Lu; Xiong Jieqi; Wang, Ping; Liu, Sisun; Guo, Fei

    2015-06-01

    Immuno-fluorescence technique can qualitatively determine certain nuclear translocation, of which NF-κB/ p65 implicates the activation of NF-κB signal pathways. Immuno-fluorescence analysis software with independent property rights is able to quantitatively analyze dynamic location of NF-κB/p65 by computing relative fluorescence units in nuclei and cytoplasm. We verified the quantitative analysis by Western Blot. When we applied the software to analysis of nuclear translocation in lipopolysaccharide (LPS) induced (0. 5 h, 1 h, 2 h, 4 h) primary human umbilical vein endothelial cells (HUVECs) , we found that nuclear translocation peak showed up at 2h as with calculated Western blot verification results, indicating that the inventive immuno-fluorescence analysis software can be applied to the quantitative analysis of immuno-fluorescence. PMID:26485997

  8. Sensitivity analysis of synergistic collaborative scenarios towards sustainable nuclear energy systems

    SciTech Connect

    Fesenko, G.; Kuznetsov, V.; Poplavskaya, E.

    2013-07-01

    The paper presents results of the study on the role of collaboration among countries towards sustainable global nuclear energy systems. The study explores various market shares for nuclear fuel cycle services, possible scale of collaboration among countries and assesses benefits and issues relevant for collaboration between suppliers and users of nuclear fuel cycle services. The approach used in the study is based on a heterogeneous world model with grouping of the non-personified nuclear energy countries according to different nuclear fuel cycle policies. The methodology applied in the analysis allocates a fraction of future global nuclear energy generation to each of such country-groups as a function of time. The sensitivity studies performed show the impacts of the group shares on the scope of collaboration among countries and on the resulting possible reactor mix and nuclear fuel cycle infrastructure versus time. The study quantitatively demonstrates that the synergistic approach to nuclear fuel cycle has a significant potential for offering a win-win collaborative strategy to both, technology holders and technology users on their joint way to future sustainable nuclear energy systems. The study also highlights possible issues on such a collaborative way. (authors)

  9. Temperature measuring analysis of the nuclear reactor fuel assembly

    SciTech Connect

    Urban, F. E-mail: zdenko.zavodny@stuba.sk; Kučák, L. E-mail: zdenko.zavodny@stuba.sk; Bereznai, J. E-mail: zdenko.zavodny@stuba.sk; Závodný, Z. E-mail: zdenko.zavodny@stuba.sk; Muškát, P. E-mail: zdenko.zavodny@stuba.sk

    2014-08-06

    Study was based on rapid changes of measured temperature values from the thermocouple in the VVER 440 nuclear reactor fuel assembly. Task was to determine origin of fluctuations of the temperature values by experiments on physical model of the fuel assembly. During an experiment, heated water was circulating in the system and cold water inlet through central tube to record sensitivity of the temperature sensor. Two positions of the sensor was used. First, just above the central tube in the physical model fuel assembly axis and second at the position of the thermocouple in the VVER 440 nuclear reactor fuel assembly. Dependency of the temperature values on time are presented in the diagram form in the paper.

  10. Analysis of nuclear reactor instability phenomena. Progress report

    SciTech Connect

    Lahey, R.T. Jr.

    1993-03-01

    The phenomena known as density-wave instability often occurs in phase change systems, such as boiling water nuclear reactors (BWRS). Our current understanding of density-wave oscillations is in fairly good shape for linear phenomena (eg, the onset of instabilities) but is not very advanced for non-linear phenomena [Lahey and Podowski, 1989]. In particular, limit cycle and chaotic instability modes are not well understood in boiling systems such as current and advanced generation BWRs (eg, SBWR). In particular, the SBWR relies on natural circulation and is thus inherently prone to problems with density-wave instabilities. The purpose of this research is to develop a quantitative understanding of nonlinear nuclear-coupled density-wave instability phenomena in BWRS. This research builds on the work of Achard et al [1985] and Clausse et al [1991] who showed, respectively, that Hopf bifurcations and chaotic oscillations may occur in boiling systems.

  11. Asymptotic Expansion Homogenization for Multiscale Nuclear Fuel Analysis

    SciTech Connect

    Hales, J. D.; Tonks, M. R.; Chockalingam, K.; Perez, D. M.; Novascone, S. R.; Spencer, B. W.; Williamson, R. L.

    2015-03-01

    Engineering scale nuclear fuel performance simulations can benefit by utilizing high-fidelity models running at a lower length scale. Lower length-scale models provide a detailed view of the material behavior that is used to determine the average material response at the macroscale. These lower length-scale calculations may provide insight into material behavior where experimental data is sparse or nonexistent. This multiscale approach is especially useful in the nuclear field, since irradiation experiments are difficult and expensive to conduct. The lower length-scale models complement the experiments by influencing the types of experiments required and by reducing the total number of experiments needed. This multiscale modeling approach is a central motivation in the development of the BISON-MARMOT fuel performance codes at Idaho National Laboratory. These codes seek to provide more accurate and predictive solutions for nuclear fuel behavior. One critical aspect of multiscale modeling is the ability to extract the relevant information from the lower length-scale sim- ulations. One approach, the asymptotic expansion homogenization (AEH) technique, has proven to be an effective method for determining homogenized material parameters. The AEH technique prescribes a system of equations to solve at the microscale that are used to compute homogenized material constants for use at the engineering scale. In this work, we employ AEH to explore the effect of evolving microstructural thermal conductivity and elastic constants on nuclear fuel performance. We show that the AEH approach fits cleanly into the BISON and MARMOT codes and provides a natural, multidimensional homogenization capability.

  12. Nuclear-power-safety reporting system: feasibility analysis

    SciTech Connect

    Finlayson, F.C.; Ims, J.

    1983-04-01

    The US Nuclear Regulatory Commission (NRC) is evaluating the possibility of instituting a data gathering system for identifying and quantifying the factors that contribute to the occurrence of significant safety problems involving humans in nuclear power plants. This report presents the results of a brief (6 months) study of the feasibility of developing a voluntary, nonpunitive Nuclear Power Safety Reporting System (NPSRS). Reports collected by the system would be used to create a data base for documenting, analyzing and assessing the significance of the incidents. Results of The Aerospace Corporation study are presented in two volumes. This document, Volume I, contains a summary of an assessment of the Aviation Safety Reporting System (ASRS). The FAA-sponsored, NASA-managed ASRS was found to be successful, relatively low in cost, generally acceptable to all facets of the aviation community, and the source of much useful data and valuable reports on human factor problems in the nation's airways. Several significant ASRS features were found to be pertinent and applicable for adoption into a NPSRS.

  13. [Cost analysis of twenty-nine nuclear medicine procedures].

    PubMed

    Kastanioti, Catherine K; Alphalbouharali, Gihand; Fotopoulos, Andreas

    2004-01-01

    The aim of this study was to compare actual cost estimates for diagnostic procedures as applied in the nuclear medicine department of our University Hospital, with cost estimates obtained through an analytical activity-based costing methodology. Activity data on the use of twenty-nine nuclear medicine procedures were collected. The actual hospital prices for the fiscal years of 2003-2004 were obtained from the Accounting Department of the Hospital. Cost estimates were calculated per patient. Activity-based data were compared with hospital prices and also with unit costs from the activity-based costing methodology. Our results showed a significant statistical difference between unit cost estimates per patient based on hospital prices, as compared with those based on unit costs. This study shows that in our university hospital, reliance on generic hospital prices for nuclear medicine procedures, considerable underestimates their real cost by a mean value of 40% as derived through the activity-based costing methodology and can lead to substantial financial hospital deficits. PMID:15841290

  14. Nuclear analysis for the intor array of loops ICRF launcher module design

    SciTech Connect

    Sawan, M.E.

    1985-07-01

    Nuclear analysis for the array of loops ICRF launcher module design of INTOR is presented. The nuclear radiation environment in the different module components is determined. The fast neutron fluence in the BeO radome is 10/sup 22/ n/cm/sup 2/ after one full power year leading to significant microcracking. Activation calculations for SF/sub 6/ imply a total activity of 5 x 10/sup 4/ Ci at shutdown. Nuclear heating results in a large breakdown rate in SF/sub 6/. A 1.6 m thick nuclear shield is needed to allow for hands-on maintenance one day after shutdown behind the launcher module. The results imply that significant design changes are required for the array of loops ICRF launcher module to stand the severe INTOR nuclear environment.

  15. Semiclassical analysis of the electron-nuclear coupling in electronic non-adiabatic processes

    NASA Astrophysics Data System (ADS)

    Agostini, Federica; Min, Seung Kyu; Gross, E. K. U.

    2015-10-01

    In the context of the exact factorization of the electron-nuclear wave function, the coupling between electrons and nuclei beyond the adiabatic regime is encoded (i) in the time-dependent vector and scalar potentials and (ii) in the electron-nuclear coupling operator. The former appear in the Schroedinger-like equation that drives the evolution of the nuclear degrees of freedom, whereas the latter is responsible for inducing non-adiabatic effects in the electronic evolution equation. As we have devoted previous studies to the analysis of the vector and scalar potentials, in this paper we focus on the properties of the electron-nuclear coupling operator, with the aim of describing a numerical procedure to approximate it within a semiclassical treatment of the nuclear dynamics.

  16. Accelerating Nuclear Magnetic Resonance (NMR) Analysis of Soil Organic Matter with Dynamic Nuclear Polarization (DNP) Enhancement

    NASA Astrophysics Data System (ADS)

    Normand, A. E.; Smith, A. N.; Long, J. R.; Reddy, K. R.

    2014-12-01

    13C magic angle spinning (MAS) solid state Nuclear Magnetic Resonance (ssNMR) has become an essential tool for discerning the chemical composition of soil organic matter (SOM). However, the technique is limited due to the inherent insensitivity of NMR resulting in long acquisition times, especially for low carbon (C) soil. The pursuits of higher magnetic fields or concentrating C with hydrofluoric acid are limited solutions for signal improvement. Recent advances in dynamic nuclear polarization (DNP) have addressed the insensitivity of NMR. DNP utilizes the greater polarization of an unpaired electron in a given magnetic field and transfers that polarization to an NMR active nucleus of interest via microwave irradiation. Signal enhancements of up to a few orders of magnitude have been achieved for various DNP experiments. In this novel study, we conduct DNP 13C cross-polarization (CP) MAS ssNMR experiments of SOM varying in soil C content and chemical composition. DNP signal enhancements reduce the experiment run time allowing samples with low C to be analyzed in hours rather than days. We compare 13C CP MAS ssNMR of SOM with multiple magnetic field strengths, hydrofluoric acid treatment, and novel DNP approaches. We also explore DNP surface enhanced NMR Spectroscopy (SENP) to determine the surface chemistry of SOM. The presented results and future DNP MAS ssNMR advances will lead to further understanding of the nature and processes of SOM.

  17. Guidance for Safety Analysis of Other Than Nuclear Facilities/Activities at the INEEL

    SciTech Connect

    Swanson, Douglas Sidney; Perry, Scott William

    2002-06-01

    The U.S. Department of Energy Idaho Operations Office (DOE-ID) provided guidance per DOE-ID Orders 420.C, "Safety Basis Review and Approval Process," and 420.D, "Requirements and Guidance for Safety Analysis," for conducting safety analysis for facilities and activities that do not meet either the nuclear facility criteria or the criteria for not requiring additional safety analysis (NRASA). These facilities and activities are thus designated as "other than nuclear" (OTN), and hazard analyses are performed using a graded approach. This graded approach is done in accordance with DOE-ID Order 420.D. DOE-ID guidance is used to format these OTN facilities and activities into 3-chapter documents, rather than the 17-chapter format specified in DOE-STD-3009-94, "Preparation Guide for U.S. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports."

  18. FINAL REPORT. DEVELOPMENT OF NUCLEAR ANALYSIS CAPABILITIES FOR DOE WASTE MANAGEMENT ACTIVITIES

    EPA Science Inventory

    The objective of this three-year Environmental Management (EM) Science Program (EMSP) project has been to develop and demonstrate prototypical analysis capabilities that can be used by nuclear safety analysis practitioners to: 1) demonstrate a more thorough understanding of the u...

  19. Living near nuclear power plants and thyroid cancer risk: A systematic review and meta-analysis.

    PubMed

    Kim, Jaeyoung; Bang, Yejin; Lee, Won Jin

    2016-02-01

    There has been public concern regarding the safety of residing near nuclear power plants, and the extent of risk for thyroid cancer among adults living near nuclear power plants has not been fully explored. In the present study, a systematic review and meta-analysis of epidemiologic studies was conducted to investigate the association between living near nuclear power plants and the risk of thyroid cancer. A comprehensive literature search was performed on studies published up to March 2015 on the association between nuclear power plants and thyroid cancer risk. The summary standardized incidence ratio (SIR), standardized mortality ratio (SMR), and 95% confidence intervals (CIs) were calculated using a random-effect model of meta-analysis. Sensitivity analyses were performed by study quality. Thirteen studies were included in the meta-analysis, covering 36 nuclear power stations in 10 countries. Overall, summary estimates showed no significant increased thyroid cancer incidence or mortality among residents living near nuclear power plants (summary SIR=0.98; 95% CI 0.87-1.11, summary SMR=0.80; 95% CI 0.62-1.04). The pooled estimates did not reveal different patterns of risk by gender, exposure definition, or reference population. However, sensitivity analysis by exposure definition showed that living less than 20 km from nuclear power plants was associated with a significant increase in the risk of thyroid cancer in well-designed studies (summary OR=1.75; 95% CI 1.17-2.64). Our study does not support an association between living near nuclear power plants and risk of thyroid cancer but does support a need for well-designed future studies. PMID:26638017

  20. Probabilistic reliability analysis, quantitative safety goals, and nuclear licensing in the United Kingdom.

    PubMed

    Cannell, W

    1987-09-01

    Although unpublicized, the use of quantitative safety goals and probabilistic reliability analysis for licensing nuclear reactors has become a reality in the United Kingdom. This conclusion results from an examination of the process leading to the licensing of the Sizewell B PWR in England. The licensing process for this reactor has substantial implications for nuclear safety standards in Britain, and is examined in the context of the growing trend towards quantitative safety goals in the United States. PMID:3685540

  1. Automated local bright feature image analysis of nuclear proteindistribution identifies changes in tissue phenotype

    SciTech Connect

    Knowles, David; Sudar, Damir; Bator, Carol; Bissell, Mina

    2006-02-01

    The organization of nuclear proteins is linked to cell and tissue phenotypes. When cells arrest proliferation, undergo apoptosis, or differentiate, the distribution of nuclear proteins changes. Conversely, forced alteration of the distribution of nuclear proteins modifies cell phenotype. Immunostaining and fluorescence microscopy have been critical for such findings. However, there is an increasing need for quantitative analysis of nuclear protein distribution to decipher epigenetic relationships between nuclear structure and cell phenotype, and to unravel the mechanisms linking nuclear structure and function. We have developed imaging methods to quantify the distribution of fluorescently-stained nuclear protein NuMA in different mammary phenotypes obtained using three-dimensional cell culture. Automated image segmentation of DAPI-stained nuclei was generated to isolate thousands of nuclei from three-dimensional confocal images. Prominent features of fluorescently-stained NuMA were detected using a novel local bright feature analysis technique, and their normalized spatial density calculated as a function of the distance from the nuclear perimeter to its center. The results revealed marked changes in the distribution of the density of NuMA bright features as non-neoplastic cells underwent phenotypically normal acinar morphogenesis. In contrast, we did not detect any reorganization of NuMA during the formation of tumor nodules by malignant cells. Importantly, the analysis also discriminated proliferating non-neoplastic cells from proliferating malignant cells, suggesting that these imaging methods are capable of identifying alterations linked not only to the proliferation status but also to the malignant character of cells. We believe that this quantitative analysis will have additional applications for classifying normal and pathological tissues.

  2. Nuclear quadrupole resonance studies project. [spectrometer design and spectrum analysis

    NASA Technical Reports Server (NTRS)

    Murty, A. N.

    1978-01-01

    The participation of undergraduates in nuclear quadrupole resonance research at Grambling University was made possible by NASA grants. Expanded laboratory capabilities include (1) facilities for high and low temperature generation and measurement; (2) facilities for radio frequency generation and measurement with the modern spectrum analyzers, precision frequency counters and standard signal generators; (3) vacuum and glass blowing facilities; and (4) miscellaneous electronic and machine shop facilities. Experiments carried out over a five year period are described and their results analyzed. Theoretical studies on solid state crystalline electrostatic fields, field gradients, and antishielding factors are included.

  3. Parametric analysis of a thermionic space nuclear power system

    NASA Technical Reports Server (NTRS)

    Strohmayer, W. H.; Van Hagan, T. H.

    1987-01-01

    Key parameters in the design of a thermionic space nuclear power system are identified and analysed in various system tradeoffs. The results are referenced to the thermionic system currently being studied for the SP-100 program. The SP-100 requirements provide definitive guidelines with respect to system optimization, the primary ones being the system mass limit of 3000 kg, the system volume constrraint of one-third of the Space Shuttle cargo bay, and the system lifetime of seven years. Many parametric influences are described and the methods used to optimize system design, in the context of the requirements, are indicated. Considerable design flexiblity is demonstrated.

  4. Combined analysis of fourteen nuclear genes refines the Ursidae phylogeny.

    PubMed

    Pagès, Marie; Calvignac, Sébastien; Klein, Catherine; Paris, Mathilde; Hughes, Sandrine; Hänni, Catherine

    2008-04-01

    Despite numerous studies, questions remain about the evolutionary history of Ursidae and additional independent genetic markers were needed to elucidate these ambiguities. For this purpose, we sequenced ten nuclear genes for all the eight extant bear species. By combining these new sequences with those of four other recently published nuclear markers, we provide new insights into the phylogenetic relationships of the Ursidae family members. The hypothesis that the giant panda was the first species to diverge among ursids is definitively confirmed and the precise branching order within the Ursus genus is clarified for the first time. Moreover, our analyses indicate that the American and the Asiatic black bears do not cluster as sister taxa, as had been previously hypothesised. Sun and sloth bears clearly appear as the most basal ursine species but uncertainties about their exact relationships remain. Since our larger dataset did not enable us to clarify this last question, identifying rare genomic changes in bear genomes could be a promising solution for further studies. PMID:18328735

  5. $ANBA; a rapid, combined data acquisition and correction program for the SEMQ electron microprobe

    USGS Publications Warehouse

    McGee, James J.

    1983-01-01

    $ANBA is a program developed for rapid data acquisition and correction on an automated SEMQ electron microprobe. The program provides increased analytical speed and reduced disk read/write operations compared with the manufacturer's software, resulting in a doubling of analytical throughput. In addition, the program provides enhanced analytical features such as averaging, rapid and compact data storage, and on-line plotting. The program is described with design philosophy, flow charts, variable names, a complete program listing, and system requirements. A complete operating example and notes to assist in running the program are included.

  6. Electron microprobe evaluation of terrestrial basalts for whole-rock K-Ar dating

    USGS Publications Warehouse

    Mankinen, E.A.; Brent, Dalrymple G.

    1972-01-01

    Four basalt samples for whole-rock K-Ar dating were analyzed with an electron microprobe to locate potassium concentrations. Highest concentrations of potassium were found in those mineral phases which were the last to crystallize. The two reliable samples had potassium concentrated in fine-grained interstitial feldspar and along grain boundaries of earlier formed plagioclase crystals. The two unreliable samples had potassium concentrated in the glassy matrix, demonstrating the ineffectiveness of basaltic glass as a retainer of radiogenic argon. In selecting basalt samples for whole-rock K-Ar dating, particular emphasis should be placed on determining the nature and condition of the fine-grained interstitial phases. ?? 1972.

  7. Procedure for conducting a human-reliability analysis for nuclear power plants. Final report

    SciTech Connect

    Bell, B.J.; Swain, A.D.

    1983-05-01

    This document describes in detail a procedure to be followed in conducting a human reliability analysis as part of a probabilistic risk assessment when such an analysis is performed according to the methods described in NUREG/CR-1278, Handbook for Human Reliability Analysis with Emphasis on Nuclear Power Plant Applications. An overview of the procedure describing the major elements of a human reliability analysis is presented along with a detailed description of each element and an example of an actual analysis. An appendix consists of some sample human reliability analysis problems for further study.

  8. Ion Microprobe Studies of Iodine Contents in Silicate Glasses and in Semarkona Chondrules

    NASA Astrophysics Data System (ADS)

    Goswami, J. N.; Sahijpal, S.; Swindle, T. D.; Musselwhite, D. S.; Grossman, J. N.

    1993-07-01

    Isotopic studies of electronegative elements (e.g. H, C, O, S, I, etc.) by the ion microprobe is best done in the negative secondary mode as the negative ion yields for these elements are much higher compared to their positive ion yields. However, analysis of non-conducting solids (e.g., silicates) in the negative secondary mode is beset with the problem of sample charging. In addition, for heavy elements like iodine, the problem of molecular interferences is also difficult to resolve. We have used a normal incidence electron gun, that generates a cloud of low energy electron near the sample surface, to overcome the problem of sample charging. The problem of molecular interferences was effectively removed by the energy filtering technique, commonly used for trace element studies [1]. Since the normal energy filtering procedure that involves introduction of appropriate offset to the sample high voltage cannot be followed in the negative secondary mode, we have introduced offset to the electrostatic analyzer (ESA) voltage, to achieve the required energy filtering. A silicon sample was analyzed to calibrate ESA voltage offset with sample voltage offset. We have initially analyzed silicon samples and a set of silicate glasses doped with iodine (0.1 to 1.5% by weight) to check for optimum conditions for measurement of low iodine concentration (

  9. Fuel cycle analysis of once-through nuclear systems.

    SciTech Connect

    Kim, T. K.; Taiwo, T. A.; Nuclear Engineering Division

    2010-08-10

    Once-through fuel cycle systems are commercially used for the generation of nuclear power, with little exception. The bulk of these once-through systems have been water-cooled reactors (light-water and heavy water reactors, LWRs and HWRs). Some gas-cooled reactors are used in the United Kingdom. The commercial power systems that are exceptions use limited recycle (currently one recycle) of transuranic elements, primarily plutonium, as done in Europe and nearing deployment in Japan. For most of these once-through fuel cycles, the ultimate storage of the used (spent) nuclear fuel (UNF, SNF) will be in a geologic repository. Besides the commercial nuclear plants, new once-through concepts are being proposed for various objectives under international advanced nuclear fuel cycle studies and by industrial and venture capital groups. Some of the objectives for these systems include: (1) Long life core for remote use or foreign export and to support proliferation risk reduction goals - In these systems the intent is to achieve very long core-life with no refueling and limited or no access to the fuel. Most of these systems are fast spectrum systems and have been designed with the intent to improve plant economics, minimize nuclear waste, enhance system safety, and reduce proliferation risk. Some of these designs are being developed under Generation IV International Forum activities and have generally not used fuel blankets and have limited the fissile content of the fuel to less than 20% for the purpose on meeting international nonproliferation objectives. In general, the systems attempt to use transuranic elements (TRU) produced in current commercial nuclear power plants as this is seen as a way to minimize the amount of the problematic radio-nuclides that have to be stored in a repository. In this case, however, the reprocessing of the commercial LWR UNF to produce the initial fuel will be necessary. For this reason, some of the systems plan to use low enriched uranium

  10. High Fidelity Thermal Simulators for Non-Nuclear Testing: Analysis and Initial Results

    NASA Technical Reports Server (NTRS)

    Bragg-Sitton, Shannon M.; Dickens, Ricky; Dixon, David

    2007-01-01

    Non-nuclear testing can be a valuable tool in the development of a space nuclear power system, providing system characterization data and allowing one to work through various fabrication, assembly and integration issues without the cost and time associated with a full ground nuclear test. In a non-nuclear test bed, electric heaters are used to simulate the heat from nuclear fuel. Testing with non-optimized heater elements allows one to assess thermal, heat transfer, and stress related attributes of a given system, but fails to demonstrate the dynamic response that would be present in an integrated, fueled reactor system. High fidelity thermal simulators that match both the static and the dynamic fuel pin performance that would be observed in an operating, fueled nuclear reactor can vastly increase the value of non-nuclear test results. With optimized simulators, the integration of thermal hydraulic hardware tests with simulated neutronie response provides a bridge between electrically heated testing and fueled nuclear testing, providing a better assessment of system integration issues, characterization of integrated system response times and response characteristics, and assessment of potential design improvements' at a relatively small fiscal investment. Initial conceptual thermal simulator designs are determined by simple one-dimensional analysis at a single axial location and at steady state conditions; feasible concepts are then input into a detailed three-dimensional model for comparison to expected fuel pin performance. Static and dynamic fuel pin performance for a proposed reactor design is determined using SINDA/FLUINT thermal analysis software, and comparison is made between the expected nuclear performance and the performance of conceptual thermal simulator designs. Through a series of iterative analyses, a conceptual high fidelity design can developed. Test results presented in this paper correspond to a "first cut" simulator design for a potential

  11. The application of utility analysis processes to estimate the impact of training for nuclear maintenance personnel

    SciTech Connect

    Groppel, C.F.

    1991-01-01

    The primary objectives of this study were to test two utility analysis models, the Cascio-Ramos Estimate of Performance in Dollars (CREPID) model and Godkewitsch financial utility analysis model and to determine their appropriateness as tools for evaluating training. This study was conducted in conjunction with Philadelphia Electric Company's Nuclear Training Group. Job performance of nuclear maintenance workers was assessed to document the impact of the training program. Assessment of job performance covered six job performance themes. Additionally, front-line nuclear maintenance supervisors were interviewed to determine their perceptions of the nuclear maintenance training. A comparison of supervisor's perceptions and outcomes of the utility analysis models was made to determine the appropriateness of utility analysis as quantitative tools for evaluating the nuclear maintenance training program. Application of the CREPID utility analysis model indicated the dollar value of the benefits of training through utility analysis was $5,843,750 which represented only four of the job performance themes. Application of the Godkewitsch utility analysis model indicated the dollar value of the benefits of training was $3,083,845 which represented all six performance themes. A comparison of the outcomes indicated a sizeable difference between the dollar values produced by the models. Supervisors indicated training resulted in improved productivity, i.e., improved efficiency and effectiveness. Additionally, supervisors believed training was valuable because it provided nonmonetary benefits, e.g., improved self-esteem and confidence. The application of utility analysis addressed only monetary benefits of training. The variation evidenced by the difference in the outcome of the two models suggests that utility analysis [open quotes]estimates[close quotes] may not accurately reflect the impact of training.

  12. Analysis of failure and maintenance experiences of motor operated valves in a Finnish nuclear power plant

    NASA Astrophysics Data System (ADS)

    Simola, Kaisa; Laakso, Kari

    1992-01-01

    Eight years of operating experiences of 104 motor operated closing valves in different safety systems in nuclear power units were analyzed in a systematic way. The qualitative methods used were Failure Mode and Effect Analysis (FMEA) and Maintenance Effects and Criticality Analysis (MECA). These reliability engineering methods are commonly used in the design stage of equipment. The successful application of these methods for analysis and utilization of operating experiences was demonstrated.

  13. Sensitivity analysis using computer calculus: A nuclear waste isolation application

    SciTech Connect

    Oblow, E.M.; Pin, F.G.; Wright, R.Q.

    1986-09-01

    An automated procedure for performing large-scale sensitivity studies based on the use of computer calculus is presented. The procedure is embodied in a FORTRAN precompiler called GRESS, which automatically processes computer models adding derivative-taking capabilities to the normal calculated results. The theory and applicability of the GRESS codes are described and tested against a major geohydrological modeling problem. The SWENT nuclear waste repository modeling code is used as the basis for these studies. Results for a test problem involving groundwater flow in the vicinity of the Richton Salt Dome are discussed in detail. Sensitivity results are compared with analytical, perturbation, and alternate sensitivity approaches to the problem. Five-place accuracy in these sensitivity results is verified for all cases in which the effects of nonlinearities are made sufficiently small. Conclusions are drawn as to the applicability of GRESS in the problem studied and for more general large-scale modeling sensitivity studies.

  14. Analysis of Nuclear Reactor Background Radiation for Neutrino Experiments

    NASA Astrophysics Data System (ADS)

    Leblanc, Ricky; Blackmon, J. C.; Rasco, B. C.; Mumm, H. P.; mTC; NuLat Collaboration

    2015-10-01

    Prior measurements of reactor antineutrinos have found a lower flux than expected. Precision measurements of antineutrino energy spectra are important for understanding the anomaly, reactor safeguards, and nuclear nonproliferation. Antineutrino detector designs rely on good characterization of gamma-ray and neutron backgrounds near the reactor core. To study the gamma-ray background at the NIST research reactor, spectra were collected using a 6.25 cm diameter × 5.5 cm germanium detector. We analyzed the measured spectra using simulations of the detector response using the GEANT4 toolkit to determine background fluxes and build a background model that will be used to understand shielding requirements and the impact of backgrounds on potential short-baseline reactor antineutrino studies at NIST. This work supported by the National Science Foundation and LSU.

  15. Next Generation Nuclear Plant Resilient Control System Functional Analysis

    SciTech Connect

    Lynne M. Stevens

    2010-07-01

    Control Systems and their associated instrumentation must meet reliability, availability, maintainability, and resiliency criteria in order for high temperature gas-cooled reactors (HTGRs) to be economically competitive. Research, perhaps requiring several years, may be needed to develop control systems to support plant availability and resiliency. This report functionally analyzes the gaps between traditional and resilient control systems as applicable to HTGRs, which includes the Next Generation Nuclear Plant; defines resilient controls; assesses the current state of both traditional and resilient control systems; and documents the functional gaps existing between these two controls approaches as applicable to HTGRs. This report supports the development of an overall strategy for applying resilient controls to HTGRs by showing that control systems with adequate levels of resilience perform at higher levels, respond more quickly to disturbances, increase operational efficiency, and increase public protection.

  16. Preliminary analysis of three cycles for nuclear propulsion of aircraft

    NASA Technical Reports Server (NTRS)

    Humble, L V; Wachtl, W W; Doyle, R B

    1950-01-01

    A preliminary study was made of the feasibility of three cycles for nuclear propulsion of aircraft: a direct-air-turbojet, a binary liquid-metal turbojet, and a helium compressor jet. All three cycles appeared feasible for flight at a Mach number of 0.9 and altitudes up to 50,000 feet; the liquid-metal cycle appeared feasible for flight at a Mach number of 1.5. The air and helium cycles resulted in heavier aircraft than did the liquid-metal cycle, particularly at a Mach number of 1.5. The relative advantage of the liquid-metal cycle became greater as the flight speed and altitude increased, and as the reactor wall temperature decreased.

  17. Nuclear magnetic resonance spectral analysis and molecular properties of berberine

    NASA Astrophysics Data System (ADS)

    Huang, Ming-Ju; Lee, Ken S.; Hurley, Sharon J.

    An extensive theoretical study of berberine has been performed at the ab initio HF/6-31G**, HF/6-311G**, and B3LYP/6-311G** levels with and without solvent effects. The optimized structures are compared with X-ray data. We found that the optimized structures with solvent effects are in slightly better agreement with X-ray data than those without solvent effects. The 1H and 13C nuclear magnetic resonance (NMR) chemical shifts of berberine were calculated by using the gauge-independent atomic orbital (GIAO) (with and without solvent effects), CSGT, and IGAIM methods. The calculated chemical shifts were compared with the two-dimensional NMR experimental data. Overall, the calculated chemical shifts show very good agreement with the experimental results. The harmonic vibrational frequencies for berberine were calculated at the B3LYP/6-311G** level.

  18. A quantitative analysis of nuclear factor I/DNA interactions.

    PubMed Central

    Meisterernst, M; Gander, I; Rogge, L; Winnacker, E L

    1988-01-01

    Nuclear factor I (NFI) was purified to homogeneity from porcine liver by DNA-affinity chromatography and displays a single band with a molecular weight of 36 kDa in SDS-polyacrylamide gels. The purified protein was used to determine absolute equilibrium binding constants by gel retardation techniques for a variety of DNA fragments with genuine or mutated NFI binding sites and a number of DNA fragments derived from various eukaryotic promoters carrying the CCAAT-box as a half-site for NFI binding. We present a model which allows prediction of the functional significance of mutated NFI binding-sites from sequence data. The data suggest that the single molecular species of NFI from porcine liver may not be able to recognize and activate the -CCAAT- promoter element in vivo without additional interactions, e.g. with other proteins. Images PMID:3380685

  19. Thermal analysis of cold vacuum drying of spent nuclear fuel

    SciTech Connect

    Piepho, M.G.

    1998-07-20

    The thermal analysis examined transient thermal and chemical behavior of the Multi canister Overpack (MCO) container for a broad range of cases that represent the Cold Vacuum Drying (CVD) processes. The cases were defined to consider both normal and off-normal operations at the CVD Facility for an MCO with Mark IV N, Reactor spent fuel in four fuel baskets and one scrap basket. This analysis provides the basis for the MCO thermal behavior at the CVD Facility for its Phase 2 Safety Analysis Report (revision 4).

  20. Analysis of Operation TEAPOT nuclear test BEE radiological and meteorological data

    SciTech Connect

    Quinn, V.E.

    1986-08-01

    This report describes the Weather Service Nuclear Support Office (WSNSO) analyses of the radiological and meteorological data collected for the BEE nuclear test of Operation TEAPOT. Inconsistencies in the radiological data and their resolution are discussed. The methods of normalizing the radiological data to a standard time and estimating fallout-arrival times are presented. The meteorological situations on event day and the following day are described. A comparison of the WSNSO fallout analysis with an analysis performed in the 1950's is presented. The radiological data used to derive the WSNSO fallout pattern are tabulated in an appendix.

  1. Analysis of operation UPSHOT-KNOTHOLE nuclear test BADGER radiological and meteorological data

    SciTech Connect

    Quinn, V.E.

    1986-04-01

    This report describes the Weather Service Nuclear Support Office (WSNSO) analyses of the radiological and meteorological data collected for the BADGER nuclear test of Operation UPSHOT-KNOTHOLE. Inconsistencies in the radiological data and their resolution are discussed. The methods of normalizing the radiological data to a standard time, of converting the aerial data to equivalent ground-level values, and of estimating fallout-arrival times are presented. The meteorological situations on event day and the following day are described. A comparison of the WSNSO fallout analysis with an analysis performed during the 1950's is presented. The radiological data used to derive the WSNSO fallout pattern are tabulated in an appendix.

  2. Analysis of operation TEAPOT nuclear test ZUCCHINI radiological and meterological data

    SciTech Connect

    Quinn, V.E.

    1987-03-01

    This report describes the Weather Service Nuclear Support Office (WSNSO) analyses of the radiological and meteorological data collected for the ZUCCHINI nuclear test of Operation TEAPOT. Inconsistencies in the radiological data and their resolution are discussed. The methods of normalizing the radiological data to a standard time and estimating fallout-arrival times are presented. The meteorological situations on event day and the following day are described. A comparison of the WSNSO fallout analysis with an analysis performed in the 1950's is presented. The radiological data used to derive the WSNSO 1986 fallout pattern are tabulated in an appendix.

  3. A microprobe technique for simultaneously measuring thermal conductivity and Seebeck coefficient of thin films

    NASA Astrophysics Data System (ADS)

    Zhang, Yanliang; Hapenciuc, Claudiu L.; Castillo, Eduardo E.; Borca-Tasciuc, Theodorian; Mehta, Rutvik J.; Karthik, Chinnathambi; Ramanath, Ganpati

    2010-02-01

    We demonstrate a microprobe technique that can simultaneously measure thermal conductivity κ and Seebeck coefficient α of thin films. In this technique, an alternative current joule-heated V-shaped microwire that serves as heater, thermometer and voltage electrode, locally heats the thin film when contacted with the surface. The κ is extracted from the thermal resistance of the microprobe and α from the Seebeck voltage measured between the probe and unheated regions of the film by modeling heat transfer in the probe, sample and their contact area, and by calibrations with standard reference samples. Application of the technique on sulfur-doped porous Bi2Te3 and Bi2Se3 films reveals α =-105.4 and 1.96 μV/K, respectively, which are within 2% of the values obtained by independent measurements carried out using microfabricated test structures. The respective κ values are 0.36 and 0.52 W/mK, which are significantly lower than the bulk values due to film porosity, and are consistent with effective media theory. The dominance of air conduction at the probe-sample contact area determines the microscale spatial resolution of the technique and allows probing samples with rough surfaces.

  4. Late Pleistocene granodiorite beneath Crater Lake caldera, Oregon, dated by ion microprobe

    USGS Publications Warehouse

    Bacon, C.R.; Persing, H.M.; Wooden, J.L.; Ireland, T.R.

    2000-01-01

    Variably melted granodiorite blocks ejected during the Holocene caldera-forming eruption of Mount Mazama were plucked from the walls of the climactic magma chamber ~15 km depth. Ion-microprobe U-Pb dating of zircons from two unmelted granodiorite blocks with SHRIMP RG (sensitive high-resolution ion microprobe-reverse geometry) gives a nominal 238U/206Pb age of 101+78-80 ka, or 174+89-115 ka when adjusted for an initial 230Th deficit. SHRIMP RG U-Th measurements on a subset of the zircons yield a 230Th/238U isochron age of 112 ?? 24 ka, considered to be the best estimate of the time of solidification of the pluton. These results suggest that the granodiorite is related to andesite and dacite of Mount Mazama and not to magmas of the climactic eruption. The unexposed granodiorite has an area of at least 28 km2. This young, shallow pluton was emplaced in virtually the same location where a similarly large magma body accumulated and powered violent explosive eruptions ~7700 yr ago, resulting in collapse of Crater Lake caldera.

  5. Implantable Microprobe with Arrayed Microsensors for Combined Amperometric Monitoring of the Neurotransmitters, Glutamate and Dopamine.

    PubMed

    Tseng, Tina T-C; Monbouquette, Harold G

    2012-08-15

    An implantable, micromachined microprobe with a microsensor array for combined monitoring of the neurotransmitters, glutamate (Glut) and dopamine (DA), by constant potential amperometry has been created and characterized. Microprobe studies in vitro revealed Glut and DA microsensor sensitivities of 126±5 nA·μM(-1)·cm(-2) and 3250±50 nA·μM(-1)·cm(-2), respectively, with corresponding detection limits of 2.1±0.2 μM and 62±8 nM, both at comparable ~1 sec response times. No diffusional interaction of H(2)O(2) among arrayed microelectrodes was observed. Also, no responses from the electroactive interferents, ascorbic acid (AA), uric acid (UA), DOPA (a DA catabolite) or DOPAC (a DA precursor), over their respective physiological concentration ranges, were detected. The dual sensing microbe attributes of size, detection limit, sensitivity, response time and selectivity make it attractive for combined sensing of Glut and DA in vivo. PMID:23139647

  6. Hyperspectral mapping-combining cathodoluminescence and X-ray collection in an electron microprobe.

    PubMed

    Macrae, Colin M; Wilson, Nicholas C; Johnson, Sally A; Phillips, Peter L; Otsuki, Masayuki

    2005-08-01

    An optical spectrometer has been integrated into a JEOL 8900R electron microprobe, which allows simultaneous collection of light, X-ray, and electron signals. The cathodoluminescence signal is collected from a monocular eyepiece, which is integrated into the electron optics of the electron microprobe. The optical acquisition is synchronized with the stage motion. X-ray lines of major elements are collected using an energy dispersive spectrometer, X-ray lines of minor elements are collected using wavelength dispersive spectrometers, and the secondary and backscattered electron signals are collected using standard detectors. In mapping mode of operation the different signals are collected at each pixel with map sizes typically ranging from 1 million to 10 million pixels. This represents a significant amount of data from which the major correlations and associations in the map can be determined. Summing over a small number of channels and examining only a subset of the complete wavelength range are the strategies that have been developed to reduce the size of the data handled. The application of this mapping technique is demonstrated with two examples, zircons and refractory bricks. Zircons with various degrees of metamictization have been characterized, and inclusions differentiated using a combination of cathodoluminescence and X-ray maps. Examination of refractory bricks reveals subtle chemical changes in the spinel grains. PMID:16170823

  7. A floating 3D silicon microprobe array for neural drug delivery compatible with electrical recording

    NASA Astrophysics Data System (ADS)

    Spieth, S.; Brett, O.; Seidl, K.; Aarts, A. A. A.; Erismis, M. A.; Herwik, S.; Trenkle, F.; Tätzner, S.; Auber, J.; Daub, M.; Neves, H. P.; Puers, R.; Paul, O.; Ruther, P.; Zengerle, R.

    2011-12-01

    This paper reports on the design, fabrication, assembly and characterization of a three-dimensional silicon-based floating microprobe array for localized drug delivery to be applied in neuroscience research. The microprobe array is composed of a silicon platform into which up to four silicon probe combs with needle-like probe shafts can be inserted. Two dedicated positions in the array allow the integration of combs for drug delivery. The implemented comb variants feature 8 mm long probe shafts with two individually addressable microchannels incorporated in a single shaft or distributed to two shafts. Liquid supply to the array is realized by a highly flexible 250 µm thick multi-lumen microfluidic cable made from polydimethylsiloxane (PDMS). The specific design concept of the slim-base platform enables floating implantation of the array in the small space between brain and skull. In turn, the flexible cable mechanically decouples the array from any microfluidic interface rigidly fixed to the skull. After assembly of the array, full functionality is demonstrated and characterized at infusion rates from 1 to 5 µL min-1. Further, the effect of a parylene-C coating on the water vapour and osmotic liquid water transport through the PDMS cable walls is experimentally evaluated by determining the respective transmission rates including the water vapour permeability of the used PDMS type.

  8. Development of Ultra Low Temperature, Impact Resistant Lithium Battery for the Mars Microprobe

    NASA Technical Reports Server (NTRS)

    Frank, H.; Deligiannis, F.; Davies, E.; Ratnakumar, Bugga V.; Surampudi, S.; Russel, P. G.; Reddy, T. B.

    1998-01-01

    The requirements of the power source for the Mars Microprobe, to be backpacked on the Mars 98 Spacecraft, are fairly demanding, with survivability to a shock of the order of 80,000 g combined with an operational requirement at -80 C. Development of a suitable power system, based on primary lithium-thionyl chloride is underway for the last eighteen months, together with Yardney Technical Products Inc., Pawcatuck, CT. The battery consists of 4 cells of 2 Ah capacity at 25 C, of which at least 25 % would be available at -80 C, at a moderate rate of C/20. Each probe contains two batteries and two such probes will be deployed. The selected cell is designed around an approximate 1/2 "D" cells, with flat plate electrodes. Significant improvements to the conventional Li-SOCl2 cell include: (a) use of tetrachlorogallate salt instead of aluminate for improved low temperature performance and reduced voltage delay, (b) optimization of the salt concentration, and (c) modification of the cell design to develop shock resistance to 80,000 g. We report here results from our several electrical performance tests, mission simulation tests, microcalorimetry and AC impedance studies, and Air gun tests. The cells have successfully gone through mission-enabling survivability and performance tests for the Mars Microprobe penetrator.

  9. Multisite monitoring of choline using biosensor microprobe arrays in combination with CMOS circuitry.

    PubMed

    Frey, Olivier; Rothe, Jörg; Heer, Flavio; van der Wal, Peter D; de Rooij, Nico F; Hierlemann, Andreas

    2014-08-01

    A miniature device enabling parallel in vivo detection of the neurotransmitter choline in multiple brain regions of freely behaving rodents is presented. This is achieved by combining a biosensor microprobe array with a custom-developed CMOS chip. Each silicon microprobe comprises multiple platinum electrodes that are coated with an enzymatic membrane and a permselective layer for selective detection of choline. The biosensors, based on the principle of amperometric detection, exhibit a sensitivity of 157±35 µA mM(-1) cm(-2), a limit of detection of below 1 µM, and a response time in the range of 1 s. With on-chip digitalization and multiplexing, parallel recordings can be performed at a high signal-to-noise ratio with minimal space requirements and with substantial reduction of external signal interference. The layout of the integrated circuitry allows for versatile configuration of the current range and can, therefore, also be used for functionalization of the electrodes before use. The result is a compact, highly integrated system, very convenient for on-site measurements. PMID:24145056

  10. Lead Slowing Down Spectrometry Analysis of Data from Measurements on Nuclear Fuel

    SciTech Connect

    Warren, Glen A.; Anderson, Kevin K.; Kulisek, Jonathan A.; Danon, Yaron; Weltz, Adam; Gavron, Victor A.; Harris, Jason; Stewart, Trevor N.

    2015-01-12

    Improved non-destructive assay of isotopic masses in used nuclear fuel would be valuable for nuclear safeguards operations associated with the transport, storage and reprocessing of used nuclear fuel. Our collaboration is examining the feasibility of using lead slowing down spectrometry techniques to assay the isotopic fissile masses in used nuclear fuel assemblies. We present the application of our analysis algorithms on measurements conducted with a lead spectrometer. The measurements involved a single fresh fuel pin and discrete 239Pu and 235U samples. We are able to describe the isotopic fissile masses with root mean square errors over seven different configurations to 6.35% for 239Pu and 2.7% for 235U over seven different configurations. Funding Source(s):

  11. Identification and Analysis of Critical Gaps in Nuclear Fuel Cycle Codes Required by the SINEMA Program

    SciTech Connect

    Adrian Miron; Joshua Valentine; John Christenson; Majd Hawwari; Santosh Bhatt; Mary Lou Dunzik-Gougar: Michael Lineberry

    2009-10-01

    The current state of the art in nuclear fuel cycle (NFC) modeling is an eclectic mixture of codes with various levels of applicability, flexibility, and availability. In support of the advanced fuel cycle systems analyses, especially those by the Advanced Fuel Cycle Initiative (AFCI), Unviery of Cincinnati in collaboration with Idaho State University carried out a detailed review of the existing codes describing various aspects of the nuclear fuel cycle and identified the research and development needs required for a comprehensive model of the global nuclear energy infrastructure and the associated nuclear fuel cycles. Relevant information obtained on the NFC codes was compiled into a relational database that allows easy access to various codes' properties. Additionally, the research analyzed the gaps in the NFC computer codes with respect to their potential integration into programs that perform comprehensive NFC analysis.

  12. Office of Nuclear Energy Knowledge Management Program Situational Analysis Report

    SciTech Connect

    Kimberlyn C. Mousseau

    2011-12-01

    Knowledge management (KM) has been a high priority for the Department of Energy (DOE) Office of Nuclear Energy (NE) for the past several years. NE Programs are moving toward well-established knowledge management practices and a formal knowledge management program has been established. Knowledge management is being practiced to some level within each of the NE programs. Although it continues to evolve as NE programs evolve, a formal strategic plan that guides the implementation of KM has been developed. Despite the acceptance of KM within DOE NE, more work is necessary before the NE KM program can be considered fully successful. Per Dr. David J. Skyrme[1], an organization typically moves through the following evolutionary phases: (1) Ad-hoc - KM is being practiced to some level in some parts of the organization; (2) Formal - KM is established as a formal project or program; (3) Expanding - the use of KM as a discipline grows in practice across different parts of the organization; (4) Cohesive - there is a degree of coordination of KM; (5) Integrated - there are formal standards and approaches that give every individual access to most organizational knowledge through common interfaces; and (6) Embedded - KM is part-and-parcel of everyday tasks; it blends seamlessly into the background. According to the evolutionary phases, the NE KM program is operating at the two lower levels, Ad-hoc and Formal. Although KM is being practiced to some level, it is not being practiced in a consistent manner across the NE programs. To be fully successful, more emphasis must be placed on establishing KM standards and processes for collecting, organizing, sharing and accessing NE knowledge. Existing knowledge needs to be prioritized and gathered on a routine basis, its existence formally recorded in a knowledge inventory. Governance to ensure the quality of the knowledge being used must also be considered. For easy retrieval, knowledge must be organized according to a taxonomy that

  13. Depth Probing Soft X-ray Microprobe (DPSXRM) for High Resolution Probing of Earth's Microstructural Samples

    NASA Astrophysics Data System (ADS)

    Dikedi, P. N.

    2015-12-01

    The Cambrian explosion; occurrence of landslides in very dry weather conditions; rockslides; dead, shriveled-up and crumbled leaves possessing fossil records with the semblance of well preserved, flat leaves; abundance of trilobite tracks in lower and higher rock layers; and sailing stones are enigmas demanding demystifications. These enigmas could be elucidated when data on soil structure, texture and strength are provided by some device with submicrometre accuracy; for these and other reasons, the design of a Depth Probing Soft X-ray Microprobe (DPSXRM), is being proposed; it is expected to deliver soft X-rays, at spatial resolution, ϛ≥600nm and to probe at the depth of 0.5m in 17s. The microprobe is portable compared to a synchrotron radiation facility (Diamond Light Source has land size of 43,300m2); spatial resolution,ϛ , of the DPSXRM surpasses those of the X-ray Fluorescence microanalysis (10µm), electron microprobe (1-3µm) and ion microprobe (5->30µm); the DPSXRM has allowance for multiple targets. Vanadium and Manganese membranes are proposed owing to respective 4.952KeV VKα1 and 5.899KeV MnKα1 X-rays emitted, which best suits micro-probing of Earth's microstructural samples. Compound systems like the Kirk-Patrick and Baez and Wolter optics, aspheric mirrors like elliptical and parabolic optics, small apertures and Abbe sine condition are employed to reduce or remove astigmatism, obliquity, comatic and spherical aberrations—leading to good image quality. Results show that 5.899KeV MnKα1 and 4.952KeV VKα1 soft X-rays will travel a distance of 2.75mm to form circular patches of radii 2.2mm and 2.95mm respectively. Zone plate with nth zone radius of 1.5mm must be positioned 1.5mm and 2mm from the electron gun if circular patches must be formed from 4.952KeV VKα1 and 5.899KeV MnKα1 soft X-rays respectively. The focal lengths of 0.25μm≤ƒ≤1.50μm and 0.04μm≤ƒ≤0.2μm covered by 4.952KeV VKα1 and 5.899KeV Mn Kα1 soft X-Rays, will

  14. Laser spectrometry and laser ablation - an ideal solution for the analysis of nuclear materials

    SciTech Connect

    Goodall, P.; Johnson, S.G.

    1996-09-01

    Nuclear materials, consisting primarily of actinides and lanthanides, produce a plethora of emission lines from the ICP. This provides an entertaining problem for the analyst applying ICP-AES. Laser ablation ICP-AES (LA-ICP-AES) offers unique advantages for the analysis of nuclear materials as it allows remote analysis of these materials in heavily shielded environments. The use of high resolution spectrometry, when coupled with LA-ICP-AES, simplifies the spectral chaos normally encountered with these materials. This obviates the requirement for analyte separation which standard ICP-AES instrumentation demands. Examples of the analysis of nuclear fuels and materials used in the reprocessing of that fuel will be presented (e.g., the determination of U, La, Y, Ce and Nd in molten salts.). In addition to bulk (or local) chemical composition, it is also possible to extract isotopic information using high resolution LA-ICP-AES (e.g., the determination of {sup 236}U for the estimation of {open_quotes}burn-up{close_quotes} of {sup 235}U in a nuclear reactor). Laser excited atomic fluorescence (LEAFS) has the advantage of high specificity at the expense of instrumental sophistication but provides one solution to the spectral complexity encountered with nuclear materials. The potential of laser ablation coupled to ICP-LEAFS will be discussed and the determination of lanthanides by LA-ICP-LEAFS described.

  15. Antineutrino analysis for continuous monitoring of nuclear reactors: Sensitivity study

    SciTech Connect

    Stewart, Christopher; Erickson, Anna

    2015-10-28

    This paper explores the various contributors to uncertainty on predictions of the antineutrino source term which is used for reactor antineutrino experiments and is proposed as a safeguard mechanism for future reactor installations. The errors introduced during simulation of the reactor burnup cycle from variation in nuclear reaction cross sections, operating power, and other factors are combined with those from experimental and predicted antineutrino yields, resulting from fissions, evaluated, and compared. The most significant contributor to uncertainty on the reactor antineutrino source term when the reactor was modeled in 3D fidelity with assembly-level heterogeneity was found to be the uncertainty on the antineutrino yields. Using the reactor simulation uncertainty data, the dedicated observation of a rigorously modeled small, fast reactor by a few-ton near-field detector was estimated to offer reduction of uncertainty on antineutrino yields in the 3.0–6.5 MeV range to a few percent for the primary power-producing fuel isotopes, even with zero prior knowledge of the yields.

  16. Antineutrino analysis for continuous monitoring of nuclear reactors: Sensitivity study

    NASA Astrophysics Data System (ADS)

    Stewart, Christopher; Erickson, Anna

    2015-10-01

    This paper explores the various contributors to uncertainty on predictions of the antineutrino source term which is used for reactor antineutrino experiments and is proposed as a safeguard mechanism for future reactor installations. The errors introduced during simulation of the reactor burnup cycle from variation in nuclear reaction cross sections, operating power, and other factors are combined with those from experimental and predicted antineutrino yields, resulting from fissions, evaluated, and compared. The most significant contributor to uncertainty on the reactor antineutrino source term when the reactor was modeled in 3D fidelity with assembly-level heterogeneity was found to be the uncertainty on the antineutrino yields. Using the reactor simulation uncertainty data, the dedicated observation of a rigorously modeled small, fast reactor by a few-ton near-field detector was estimated to offer reduction of uncertainty on antineutrino yields in the 3.0-6.5 MeV range to a few percent for the primary power-producing fuel isotopes, even with zero prior knowledge of the yields.

  17. Analysis by simulation of the disposition of nuclear fuel waste

    SciTech Connect

    Turek, J.L.

    1980-09-01

    A descriptive simulation model is developed which includes all aspects of nuclear waste disposition. The model is comprised of two systems, the second system orchestrated by GASP IV. A spent fuel generation prediction module is interfaced with the AFR Program Management Information System and a repository scheduling information module. The user is permitted a wide range of options with which to tailor the simulation to any desired storage scenario. The model projects storage requirements through the year 2020. The outputs are evaluations of the impact that alternative decision policies and milestone date changes have on the demand for, the availability of, and the utilization of spent fuel storage capacities. Both graphs and detailed listings are available. These outputs give a comprehensive view of the particular scenario under observation, including the tracking, by year, of each discharge from every reactor. Included within the work is a review of the status of spent fuel disposition based on input data accurate as of August 1980. The results indicate that some temporary storage techniques (e.g., transshipment of fuel and/or additional at-reactor storage pools) must be utilized to prevent reactor shutdowns. These techniques will be required until the 1990's when several AFR facilities, and possibly one repository, can become operational.

  18. Joint Institute for Nuclear Research Data Analysis Guide - Berkelium Edition

    SciTech Connect

    Henderson, R A

    2009-07-23

    This is a data analysis guide to the JINR system developed by Roger Henderson. It is intended as a complete guide to the data format and the calibration parameters utilized for the analysis of the data. This guide will provide the basic structure of the data files, the description of the individual data items, and the basic equations developed for the calculation of the results. Currently (7/17/2009), calculation of the calibration parameters is not a covered topic. It is intended that this will be covered in a future update.

  19. Electron microprobe study of lunar and planetary zoned plagioclase feldspars: An analytical and experimental study of zoning in plagioclase

    NASA Technical Reports Server (NTRS)

    Smith, R. K.; Lofgren, G. E.

    1982-01-01

    Natural and experimentally grown zoned plagioclase feldspars were examined by electron microprobe. The analyses revealed discontinuous, sector, and oscillary chemical zoning superimposed on continuous normal or reverse zoning trends. Postulated mechanisms for the origin of zoning are based on either physical changes external to the magma (P, T, H2O saturation) or kinetic changes internal to the magma (diffusion, supersaturation, growth rate). Comparison of microprobe data on natural zoned plagioclase with zoned plagioclase grown in controlled experiments show that it may be possible to distinguish zonal development resulting from physio-chemical changes to the bulk magma from local kinetic control on the growth of individual crystals.

  20. Ion and laser microprobes applied to the measurement of corrosion-produced hydrogen on a microscopic scale

    NASA Technical Reports Server (NTRS)

    Gray, H. R.

    1971-01-01

    An ion microprobe and a laser microprobe were used to measure concentrations of corrosion-produced hydrogen on a microscopic scale. Hydrogen concentrations of several thousand ppm were measured by both analytical techniques below the fracture surfaces of hot-salt stress-corroded titanium alloy specimens. This segregation of hydrogen below fracture surfaces supports a previously proposed theory that corrosion-produced hydrogen is responsible for hot-salt stress-corrosion embrittlement and cracking of titanium alloys. These advanced analytical techniques suggest great potential for many areas of stress-corrosion and hydrogen embrittlement research, quality control, and field inspection applications.

  1. Report to the US Nuclear Regulatory Commission on Analysis and Evaluation of Operational Data, 1986

    SciTech Connect

    1987-05-01

    This annual report of the US Nuclear Regulatory Commission's Office for Analysis and Evaluation of Operational Data (AEOD) is devoted to the activities performed during calendar year 1986. Comments and observations are provided on operating experience at nuclear power plants and other NRC licensees, including results from selected AEOD studies; summaries of abnormal occurrences involving US nuclear plants; reviews of licensee event reports and their quality, reactor scram experience from 1984 to 1986, engineered safety features actuations, and the trends and patterns analysis program; and assessments of nonreactor and medical misadministration events. In addition, the report provides the year-end status of all recommendations included in AEOD studies, and listings of all AEOD reports issued from 1980 through 1986.

  2. A Delayed Neutron Counting System for the Analysis of Special Nuclear Materials

    NASA Astrophysics Data System (ADS)

    Sellers, Madison Theresa

    Nuclear forensic analysis is a modem science that uses numerous analytical techniques to identify and attribute nuclear materials in the event of a nuclear explosion, radiological terrorist attack or the interception of illicit nuclear material smuggling. The Canadian Department of National Defence has participated in recent international exercises that have highlighted the Nation's requirement to develop nuclear forensics expertise, protocol and capabilities, specifically pertaining to the analysis of special nuclear materials (SNM). A delayed neutron counting (DNC) system has been designed and established at the Royal Military College of Canada (RMC) to enhance the Government's SNM analysis capabilities. This analytical technique complements those already at RMC by providing a rapid and non-destructive method for the analysis of the fissile isotopes of both uranium (U) and plutonium (Pu). The SLOWPOKE-2 reactor at RMC produces a predominately thermal neutron flux. These neutrons induce fission in the SNM isotopes 233U, 235U and 239Pu releasing prompt fast neutrons, energy and radioactive fission fragments. Some of these fission fragments undergo beta - decay and subsequently emit neutrons, which can be recorded by an array of sensitive 3He detectors. The significant time period between the fission process and the release of these neutrons results in their identification as 'delayed neutrons'. The recorded neutron spectrum varies with time and the count rate curve is unique to each fissile isotope. In-house software, developed by this project, can analyze this delayed neutron curve and provides the fissile mass in the sample. Extensive characterization of the DNC system has been performed with natural U samples with 235 U content ranging from 2--7 microg. The system efficiency and dead time behaviour determined by the natural uranium sample analyses were validated by depleted uranium samples with similar quantities of 235 U resulting in a typical relative error of

  3. HEAT TRANSFER ANALYSIS FOR NUCLEAR WASTE SOLIDIFICATION CONTAINER

    SciTech Connect

    Lee, S.

    2009-06-01

    The Nuclear Nonproliferation Programs Design Authority is in the design stage of the Waste Solidification Building (WSB) for the treatment and solidification of the radioactive liquid waste streams generated by the Pit Disassembly and Conversion Facility (PDCF) and Mixed Oxide (MOX) Fuel Fabrication Facility (MFFF). The waste streams will be mixed with a cementitious dry mix in a 55-gallon waste container. Savannah River National Laboratory (SRNL) has been performing the testing and evaluations to support technical decisions for the WSB. Engineering Modeling & Simulation Group was requested to evaluate the thermal performance of the 55-gallon drum containing hydration heat source associated with the current baseline cement waste form. A transient axi-symmetric heat transfer model for the drum partially filled with waste form cement has been developed and heat transfer calculations performed for the baseline design configurations. For this case, 65 percent of the drum volume was assumed to be filled with the waste form, which has transient hydration heat source, as one of the baseline conditions. A series of modeling calculations has been performed using a computational heat transfer approach. The baseline modeling results show that the time to reach the maximum temperature of the 65 percent filled drum is about 32 hours when a 43 C initial cement temperature is assumed to be cooled by natural convection with 27 C external air. In addition, the results computed by the present model were compared with analytical solutions. The modeling results will be benchmarked against the prototypic test results. The verified model will be used for the evaluation of the thermal performance for the WSB drum. Detailed results and the cases considered in the calculations will be discussed here.

  4. Shielding analysis of a small compact space nuclear reactor

    NASA Astrophysics Data System (ADS)

    Woodrow, Lee L., Jr.

    1987-08-01

    The SP-100 reactor, currently in its developmental stage, has a layered tungsten-lithium hydride shield. Studies indicate that this shield configuration is the lightest weight shield. This configuration and three other shielding concepts were analyzed to determine the lightest shield and to determine the shield configuration with the smallest volume. The other concepts were a boron carbide-beryllium layered shield, and a lithium hydride-beryllium shield. FEMP2D and FEMP1D codes were used in this analysis. These codes were developed at Sandia National Laboatory (SNL), using the input from another code, RFCC, which produced enery dependent dose conversion factors, and determined the shields' ability to attenuate the neutron and gamma radiation to permissible dose limits. The results of this analysis show that the lithium hydribe-tungsten layered shield was indeed the lightest weight shield. Volume, not weight, may be the driving factor in determining the shield configuration.

  5. Spreadsheet analysis of gamma spectra for nuclear material measurements

    SciTech Connect

    Mosby, W.R.; Pace, D.M.

    1990-01-01

    A widely available commercial spreadsheet package for personal computers is used to calculate gamma spectra peak areas using both region of interest and peak fitting methods. The gamma peak areas obtained are used for uranium enrichment assays and for isotopic analyses of mixtures of transuranics. The use of spreadsheet software with an internal processing language allows automation of routine analysis procedures increasing ease of use and reducing processing errors while providing great flexibility in addressing unusual measurement problems. 4 refs., 9 figs.

  6. Development of an x-ray fluorescence microprobe at the National Synchrotron Light Source, Brookhaven National Laboratory: Early results: Comparison with data from other techniques

    SciTech Connect

    Smith, J.V.; Rivers, M.L.; Sutton, S.R.; Jones, K.W.; Hanson, A.L.; Gordon, B.M.

    1986-01-01

    Theoretical predictions for the detection levels in x-ray fluorescence analysis with a synchrotron storage ring are being achieved experimentally at several laboratories. This paper is deliberately restricted to the state of development of the Brookhaven National Laboratory/University of Chicago instruments. Analyses at the parts per million (ppM) level are being made using white light apertured to 20 ..mu..m and an energy dispersive system. This system is particularly useful for elements with Z > 20 in materials dominated by elements with Z < 20. Diffraction causes an interference for crystalline materials. Development of a focusing microprobe for tunable monochromatic x-rays and a wavelength dispersive spectrometer (WDS) is delayed by problems in shaping an 8:1 focusing mirror to the required accuracy. Reconnaissance analyses with a wiggler source on the CHESS synchrotron have been made in the K spectrum up to Z = 80.

  7. LANDSAT-4 image data quality analysis for energy related applications. [nuclear power plant sites

    NASA Technical Reports Server (NTRS)

    Wukelic, G. E. (Principal Investigator)

    1983-01-01

    No useable LANDSAT 4 TM data were obtained for the Hanford site in the Columbia Plateau region, but TM simulator data for a Virginia Electric Company nuclear power plant was used to test image processing algorithms. Principal component analyses of this data set clearly indicated that thermal plumes in surface waters used for reactor cooling would be discrenible. Image processing and analysis programs were successfully testing using the 7 band Arkansas test scene and preliminary analysis of TM data for the Savanah River Plant shows that current interactive, image enhancement, analysis and integration techniques can be effectively used for LANDSAT 4 data. Thermal band data appear adequate for gross estimates of thermal changes occurring near operating nuclear facilities especially in surface water bodies being used for reactor cooling purposes. Additional image processing software was written and tested which provides for more rapid and effective analysis of the 7 band TM data.

  8. Materials characterization center workshop on compositional and microstructural analysis of nuclear waste materials. Summary report

    SciTech Connect

    Daniel, J.L.; Strachan, D.M.; Shade, J.W.; Thomas, M.T.

    1981-06-01

    The purpose of the Workshop on Compositional and Microstructural Analysis of Nuclear Waste Materials, conducted November 11 and 12, 1980, was to critically examine and evaluate the various methods currently used to study non-radioactive, simulated, nuclear waste-form performance. Workshop participants recognized that most of the Materials Characterization Center (MCC) test data for inclusion in the Nuclear Waste Materials Handbook will result from application of appropriate analytical procedures to waste-package materials or to the products of performance tests. Therefore, the analytical methods must be reliable and of known accuracy and precision, and results must be directly comparable with those from other laboratories and from other nuclear waste materials. The 41 participants representing 18 laboratories in the United States and Canada were organized into three working groups: Analysis of Liquids and Solutions, Quantitative Analysis of Solids, and Phase and Microstructure Analysis. Each group identified the analytical methods favored by their respective laboratories, discussed areas needing attention, listed standards and reference materials currently used, and recommended means of verifying interlaboratory comparability of data. The major conclusions from this workshop are presented.

  9. An enhancement of NASTRAN for the seismic analysis of structures. [nuclear power plants

    NASA Technical Reports Server (NTRS)

    Burroughs, J. W.

    1980-01-01

    New modules, bulk data cards and DMAP sequence were added to NASTRAN to aid in the seismic analysis of nuclear power plant structures. These allow input consisting of acceleration time histories and result in the generation of acceleration floor response spectra. The resulting system contains numerous user convenience features, as well as being reasonably efficient.

  10. The TOMAS software system for approximate analysis of emergency situations at nuclear power stations

    NASA Astrophysics Data System (ADS)

    Zhukavin, A. P.

    2009-05-01

    The TOMAS software system for carrying out prompt analysis of different emergency situations in power units of nuclear power stations equipped with VVER-1000 and RBMK-1000 reactors is described. This software system can be used by experts of crisis centers for evaluating various situations, as well as for teaching students in higher schools specializing in the appropriate disciplines.

  11. A Discriminant Analysis of Attitudes Related to the Nuclear Power Controversy.

    ERIC Educational Resources Information Center

    Girondi, Alfred J.

    1983-01-01

    This study was designed to develop a test instrument for measuring selected attitudes toward nuclear power, determine if attitudinal differences existed between selected groups of individuals, describe group differences in attitude, and classify group members as either anti- or pronuclear. Results, based on discriminant analysis, are reported and…

  12. Chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade plutonium nitrate solutions

    SciTech Connect

    Not Available

    1981-01-01

    These analytical procedures are designed to show whether a given material meets the purchaser's specifications as to plutonium content, effective fissile content, and impurity content. The following procedures are described in detail: plutonium by controlled-potential coulometry; plutonium by amperometric titration with iron(II); free acid by titration in an oxalate solution; free acid by iodate precipitation-potentiometric titration method; uranium by Arsenazo I spectrophotometric method; thorium by thorin spectrophotometric method; iron by 1,10-phenanthroline spectrophotometric method; chloride by thiocyanate spectrophotometric method; fluoride by distillation-spectrophotometric method; sulfate by barium sulfate turbidimetric method; isotopic composition by mass spectrometry; americium-241 by extraction and gamma counting; americium-241 by gamma counting; gamma-emitting fission products, uranium, and thorium by gamma-ray spectroscopy; rare earths by copper spark spectrochemical method; tungsten, niobium (columbium), and tantalum by spectrochemical method; simple preparation by spectrographic analysis for general impurities. (JMT)

  13. Development of a Tender-Energy Microprobe for Geosciences at NSLS and NSLS-II

    SciTech Connect

    Northrup, Paul A.

    2014-08-30

    We propose to develop a tender-energy (1-8 keV operational range, optimized for 1-5 keV) X-ray microprobe, to bring the functionality and scientific benefits of hard (>5 keV) X-ray microprobes to a largely untapped domain of lighter, geologically-important elements. This proposal seeks to extend and enhance user-facility capabilities particularly optimized for research in Geosciences. This will be accomplished through development and implementation of unique new synchrotron instrumentation for high-performance microspectroscopy and imaging in the distinctive tender energy range. This new user facility at Beamline X15B at the National Synchrotron Light Source (NSLS) will benefit the specific Earth Science research programs described in this proposal, and will be available for use by the broader community through the merit-based General User program and through the User Cooperative that operates X15B. Its development will provide immediate benefit to regional and national Earth Science research conducted at the NSLS. It will achieve even higher performance at the Tender Energy Spectroscopy (TES) Beamline at NSLS-II, a new state-of-the-art synchrotron under construction and scheduled to begin operation in 2014. Project Objectives: Our goals are threefold: 1. Develop superlative capabilities to extend hard X-ray microprobe functionality and ease of use to the tender energy range. 2. Bring high-performance XAS (including full EXAFS) to the micron scale, over the range of 1-8 keV. 3. Deliver high flux and element sensitivity for geoscience applications. Our user facility will be designed and optimized for tender-energy microbeam applications and techniques for Earth Science research, including XRF imaging and high-quality extended XAS. Its key attributes will be an energy range of 1 to 8 keV, user-tunable spot size ranging from 40x14 to 3x2 μm, high flux up to 2x1011 photons/s, beam positional stability and energy calibration stability optimized for high-quality and

  14. Report of the Nuclear Propulsion Mission Analysis, Figures of Merit Subpanel: Quantifiable figures of merit for nuclear thermal propulsion

    NASA Technical Reports Server (NTRS)

    Haynes, Davy A.

    1991-01-01

    The results of an inquiry by the Nuclear Propulsion Mission Analysis, Figures of Merit subpanel are given. The subpanel was tasked to consider the question of what are the appropriate and quantifiable parameters to be used in the definition of an overall figure of merit (FoM) for Mars transportation system (MTS) nuclear thermal rocket engines (NTR). Such a characterization is needed to resolve the NTR engine design trades by a logical and orderly means, and to provide a meaningful method for comparison of the various NTR engine concepts. The subpanel was specifically tasked to identify the quantifiable engine parameters which would be the most significant engine factors affecting an overall FoM for a MTS and was not tasked with determining 'acceptable' or 'recommended' values for the identified parameters. In addition, the subpanel was asked not to define an overall FoM for a MTS. Thus, the selection of a specific approach, applicable weighting factors, to any interrelationships, for establishing an overall numerical FoM were considered beyond the scope of the subpanel inquiry.

  15. Dynamical analysis of mCAT2 gene models with CTN-RNA nuclear retention

    NASA Astrophysics Data System (ADS)

    Wang, Qianliang; Zhou, Tianshou

    2015-02-01

    As an experimentally well-studied nuclear-retained RNA, CTN-RNA plays a significant role in many aspects of mouse cationic amino acid transporter 2 (mCAT2) gene expression, but relevant dynamical mechanisms have not been completely clarified. Here we first show that CTN-RNA nuclear retention can not only reduce pre-mCAT2 RNA noise but also mediate its coding partner noise. Then, by collecting experimental observations, we conjecture a heterodimer formed by two proteins, p54nrb and PSP1, named p54nrb-PSP1, by which CTN-RNA can positively regulate the expression of nuclear mCAT2 RNA. Therefore, we construct a sequestration model at the molecular level. By analyzing the dynamics of this model system, we demonstrate why most nuclear-retained CTN-RNAs stabilize at the periphery of paraspeckles, how CTN-RNA regulates its protein-coding partner, and how the mCAT2 gene can maintain a stable expression. In particular, we obtain results that can easily explain the experimental phenomena observed in two cases, namely, when cells are stressed and unstressed. Our entire analysis not only reveals that CTN-RNA nuclear retention may play an essential role in indirectly preventing diseases but also lays the foundation for further study of other members of the nuclear-regulatory RNA family with more complicated molecular mechanisms.

  16. Analysis of the formation, expression, and economic impacts of risk perceptions associated with nuclear facilities

    SciTech Connect

    Allison, T.; Hunter, S.; Calzonetti, F.J.

    1992-10-01

    This report investigates how communities hosting nuclear facilities form and express perceptions of risk and how these risk perceptions affect local economic development. Information was collected from site visits and interviews with plant personnel, officials of local and state agencies, and community activists in the hosting communities. Six commercial nuclear fuel production facilities and five nuclear facilities operated for the US Department of Energy by private contractors were chosen for analysis. The results presented in the report indicate that the nature of risk perceptions depends on a number of factors. These factors are (1) level of communication by plant officials within the local community, (2) track record of the facility. operator, (3) process through which community and state officials receive information and form opinions, (4) level of economic links each plant has with the local community, and (15) physical characteristics of the facility itself. This report finds that in the communities studied, adverse ask perceptions have not affected business location decisions, employment levels in the local community, tourism, or agricultural development. On the basis of case-study findings, this report recommends that nuclear facility siting programs take the following observations into account when addressing perceptions of risk. First, the quality of a facility`s participation with community activists, interest groups, and state agencies helps to determine the level of perceived risk within a community. Second, the development of strong economic links between nuclear facilities and their host communities will produce a higher level of acceptance of the nuclear facilities.

  17. Some studies on the use of NASTRAN for nuclear power plant structural analysis and design

    NASA Technical Reports Server (NTRS)

    Setlur, A. V.; Valathur, M.

    1973-01-01

    Studies made on the use of NASTRAN for nuclear power plant analysis and design are presented. These studies indicate that NASTRAN could be effectively used for static, dynamic and special purpose problems encountered in the design of such plants. Normal mode capability of NASTRAN is extended through a post-processor program to handle seismic analysis. Static and dynamic substructuring is discussed. Extension of NASTRAN to include the needs in the civil engineering industry is discussed.

  18. Fire accident analysis modeling in support of non-reactor nuclear facilities at Sandia National Laboratories

    SciTech Connect

    Restrepo, L.F.

    1993-06-01

    The Department of Energy (DOE) requires that fire hazard analyses (FHAs) be conducted for all nuclear and new facilities, with results for the latter incorporated into Title I design. For those facilities requiring safety analysis documentation, the FHA shall be documented in the Safety Analysis Reports (SARs). This paper provides an overview of the methodologies and codes being used to support FHAs at Sandia facilities, with emphasis on SARs.

  19. Improved spatial resolution for U-series dating of opal at Yucca Mountain, Nevada, USA, using ion-microprobe and microdigestion methods

    USGS Publications Warehouse

    Paces, J.B.; Neymark, L.A.; Wooden, J.L.; Persing, H.M.

    2004-01-01

    Two novel methods of in situ isotope analysis, ion microprobe and microdigestion, were used for 230Th/U and 234U/238U dating of finely laminated opal hemispheres formed in unsaturated felsic tuff at Yucca Mountain, Nevada, proposed site for a high-level radioactive waste repository. Both methods allow analysis of layers as many as several orders of magnitude thinner than standard methods using total hemisphere digestion that were reported previously. Average growth rates calculated from data at this improved spatial resolution verified that opal grew at extremely slow rates over the last million years. Growth rates of 0.58 and 0.69 mm/m.y. were obtained for the outer 305 and 740 ??m of two opal hemispheres analyzed by ion microprobe, and 0.68 mm/m.y. for the outer 22 ??m of one of these same hemispheres analyzed by sequential microdigestion. These Pleistocene growth rates are 2 to 10 times slower than those calculated for older secondary calcite and silica mineral coatings deposited over the last 5 to 10 m.y. dated by the U-Pb method and may reflect differences between Miocene and Pleistocene seepage flux. The microdigestion data also imply that opal growth rates may have varied over the last 40 k.y. These data are the first indication that growth rates and associated seepage in the proposed repository horizon may correlate with changes in late Pleistocene climate, involving faster growth during wetter, cooler climates (glacial maximum), slower growth during transition climates, and no growth during the most arid climate (modern). Data collected at this refined spatial scale may lead to a better understanding of the hydrologic variability expected within the thick unsaturated zone at Yucca Mountain over the time scale of interest for radioactive waste isolation. ?? 2004 Elsevier Ltd.

  20. Collaborative human-machine nuclear non-proliferation analysis

    SciTech Connect

    Greitzer, F.L.; Badalamente, R.V.; Stewart, T.S.

    1993-10-01

    The purpose of this paper is to report on the results of a project investigating support concepts for the information treatment needs of the International Atomic Energy Agency (IAEA, also referred to as the Agency) and its attempts to strengthen international safeguards. The aim of the research was to define user/computer interface concepts and intelligent support features that will enhance the analyst`s access to voluminous and diverse information, the ability to recognize and evaluate uncertain data, and the capability to make decisions and recommendations. The objective was to explore techniques for enhancing safeguards analysis through application of (1) more effective user-computer interface designs and (2) advanced concepts involving human/system collaboration. The approach was to identify opportunities for human/system collaboration that would capitalize on human strengths and still accommodate human limitations. This paper documents the findings and describes a concept prototype, Proliferation Analysis Support System (PASS), developed for demonstration purposes. The research complements current and future efforts to enhance the information systems used by the IAEA, but has application elsewhere, as well.

  1. Chemical, mass spectrometric, spectrochemical, nuclear and radiochemical analysis of nuclear-grade plutonium metal

    SciTech Connect

    Not Available

    1981-01-01

    These analytical procedures are designed to show whether a given material meets the purchaser's specifications as to plutonium content, effective fissile content, and impurity content. The following procedures are described in detail: dissolution procedure; plutonium by controlled-potential coulometry; plutonium by amperometric titration with iron(II); plutonium by ceric sulfate titration method; uranium by Arsenazo I spectrophotometric method; thorium by thorin spectrophotometric method; iron by 1,10-phenanthroline spectrophotometric method; iron by 2,2'-bipyridyl spectrophotometric method; chloride by the thiocyanate spectrophotometric method; fluoride by distillation-spectrophotometric method; nitrogen by distillation-Nessler reagent spectrophotometric method; carbon by the direct combustion-thermal conductivity method; sulfur by distillation-spectrophotometric method; isotopic composition by mass spectrometry; Americium-241 by extraction and gamma counting; Americium-241 by gamma counting; gamma-emitting fission products, uranium, and thorium by gamma-ray spectroscopy; rare earths by copper spark spectrochemical method; tungsten, niobium (columbium) and tantalum by spectrochemical method; sample preparation for spectrographic analysis for trace impurities. (JMT)

  2. Common cause failure analysis of the rodded scram system of the Arkansas Nuclear One-Unit 1 Plant

    SciTech Connect

    Montague, D.F.; Campbell, D.J.; Flanagan, G.F.

    1986-10-01

    This study demonstrates the use of a formal method for common cause failure analysis in a reliability analysis of the Arkansas Nuclear One - Unit 1 rodded scram system. The scram system failure of interest is loss of capability of the system to shut the reactor down when required. The results of this analysis support the ATWS program sponsored by the US Nuclear Regulatory Commission. The methods used in this analysis support the NRC's Risk Methods Integration and Evaluation Program (RMIEP).

  3. MCO Pressurization analysis of spent nuclear fuel transporation and storage

    SciTech Connect

    Ogden, D.M., Westinghouse Hanford

    1996-09-20

    A series of analysis were performed to evaluate the pressurization of the Multi-Canister Overpack (MCO) during the stages of transport, processing and storage for expected operational and off normal events. The study examined both MCO sealing and venting issues. Computer models were developed for the MCO and its transport and storage environments using the GOTH and COBRA-TF computer codes. These thermal- hydraulic models included chemical corrosion and ranged in complexity from simple scoping models to full three-dimensional models. Results of the evaluation indicate that overpressurization of the MCO can occur within hours given the bounding reaction surface area and 3.0 Kg of residual water during shipping or 2.5 Kg of residual water during storage. Overpressurization can be prevented during shipping if the MCO reaction surface area is shown to be less than 80,000 cm{sup 2}. During storage the overpressurization can be prevented by limiting the available water.

  4. Secondary ionization mass spectrometric analysis of impurity element isotope ratios in nuclear reactor materials

    NASA Astrophysics Data System (ADS)

    Gerlach, D. C.; Cliff, J. B.; Hurley, D. E.; Reid, B. D.; Little, W. W.; Meriwether, G. H.; Wickham, A. J.; Simmons, T. A.

    2006-07-01

    During reactor operations and fuel burn up, some isotopic abundances change due to nuclear reactions and provide sensitive indicators of neutron fluence and fuel burnup. Secondary ion mass spectrometry (SIMS) analysis has been used to measure isotope ratios of selected impurity elements in irradiated nuclear reactor graphite. Direct SIMS measurements were made in graphite samples, following shaping and surface cleaning. Models predicting local fuel burnup based on isotopic measurements of B and Li isotopes by SIMS agreed well with U and Pu isotopic measurements obtained by thermal ionization mass spectrometry (TIMS).

  5. Analysis of operation UPSHOT-KNOTHOLE nuclear test SIMON radiological and meteorological data

    SciTech Connect

    Steadman, C.R. Jr.

    1988-07-01

    The Weather Service Nuclear Support Office has constructed a fallout pattern of the 1953 SIMON nuclear event, using that radiological and meteorological data available in 1987. This report presents the techniques employed in the fallout analysis, tabulates and evaluates the radiological data, relates the deposition pattern to the meteorological situation, and points out inconsistencies and limitations. In addition, the 1987 pattern is compared with the SIMON pattern published by the US Weather Bureau in 1956. While there are many similarities, there are some substantial differences. 28 refs., 21 figs., 16 tabs.

  6. Microprobe Evaluations of Grain Boundary Segregation in KM4 and IN100

    NASA Technical Reports Server (NTRS)

    Gabb, T. P.; Smith, J. W.

    2001-01-01

    Turbine disk alloys subjected to fatigue cycles with dwells at high temperatures and stresses can fail by cracking along grain boundaries. This could be due to concentrated creep deformation or environmental attack at grain boundaries. It would be important to identify any chemical segregation along grain boundaries to aid understanding of this intergranular failure mode. The objective of this study was to evaluate the degree of chemical segregation present at the grain boundaries of two disk alloys, KM4 and IN 100. An electron microprobe employing wavelength dispersive x-ray chemical analyses was used to characterize the chemistry along multiple grain boundaries in metallographically prepared samples of each alloy. Some degrees of boron, chromium, and cobalt enrichment of grain boundaries were observed in each alloy.

  7. Hg diffusion in books of XVIII and XIX centuries by synchrotron microprobe

    NASA Astrophysics Data System (ADS)

    Pessanha, S.; Carvalho, M. L.; Manso, M.; Guilherme, A.; Marques, A. F.; Perez, C. A.

    2009-08-01

    The pigment vermilion (HgS) was used to color the fore edge, tail and head of books. Dissemination and quantification of Hg present in the ink used to color books from XVIII and XIX centuries are reported. Mercury is a very toxic element for the human body, therefore it is extremely important to know whether Hg tends to disseminate throughout the paper or stays confined to the borders of the books with less danger for readers. Synchrotron X-ray microprobe was used to evaluate Hg dissemination from the border to the centre of the paper sheet. The diffusion pattern of Hg was compared with the results obtained by a portable X-ray fluorescence spectrometer and mean quantitative calculations were obtained by a stationary X-ray fluorescence system with triaxial geometry. The results showed high concentrations of Hg in the external regions, but no diffusion was observed for the inner parts of the paper.

  8. Lithium tracer-diffusion in an alkali-basaltic melt — An ion-microprobe determination

    NASA Astrophysics Data System (ADS)

    Lowry, R. K.; Reed, S. J. B.; Nolan, J.; Henderson, P.; Long, J. V. P.

    1981-03-01

    An ion-microprobe-based technique has been used to measure lithium tracer-diffusion coefficients ( D Li) in an alkali-basaltic melt at 1300, 1350 and 1400°C. The results can be expressed in the form: D Li=7.5 ×10 -2exp(-27,600/RT)cm 2S -1 The results show significantly faster diffusion rates than those previously recorded for other monovalent, divalent and trivalent cations in a tholeiitic melt. Consequently, diffusive transport of ions acting over a given time in a basaltic melt can produce a wider range of transport distance values than hitherto supposed. Hence, it is concluded that great care should be exercised when applying diffusion data to petrological problems.

  9. Garnet/high-silica rhyolite trace element partition coefficients measured by ion microprobe

    USGS Publications Warehouse

    Sisson, T.W.; Bacon, C.R.

    1992-01-01

    Garnet/liquid trace element partition coefficients have been measured in situ by ion microprobe in a rhyolite from Monache Mountain, California. Partition coefficients are reported for La, Ce, Nd, Sm, Dy, Er, Yb, Sc, Ti, V, Cr, Sr, Y, and Zr. The in situ analyses avoid the problem of contamination of the garnet phase by trace element-rich accessory minerals encountered in traditional bulk phenocryst/matrix partitioning studies. The partitioning pattern for the rare earth elements (REEs, excluding Eu) is smooth and rises steeply from the light to the heavy REEs with no sharp kinks or changes in slope, unlike patterns for garnet /silicic liquid REE partitioning determined by bulk methods. This difference suggests that the previous determinations by bulk methods are in error, having suffered from contamination of the phenocryst separates. ?? 1992.

  10. LASER MICROPROBE **4**0Ar/**3**9Ar DATING OF MINERAL GRAINS IN SITU.

    USGS Publications Warehouse

    Sutter, J.F.; Hartung, J.B.

    1984-01-01

    A laser-microprobe attached to a mass spectrometer for **4**0Ar/**3**9Ar age determination of single mineral grains in geological materials has been made operational at the US Geological Survey, Reston, VA. This microanalytical technique involves focusing a pulsed laser beam onto a sample contained in an ultra-high vacuum chamber attached to a rare-gas mass spectrometer. Argon in the neutron-irradiated sample is released by heating with the laser pulse and its isotopic composition is measured to yield an **4**0Ar/**3**9Ar age. Laser probe **4**0Ar/**3**9Ar ages of single mineral grains measured in situ can aid greatly in understanding the chronology of many geological situations where datable minerals are present but are not physically separable in quantities needed for conventional age dating.

  11. Electron microprobe analyses of Ca, S, Mg and P distribution in incisors of Spacelab-3 rats

    NASA Technical Reports Server (NTRS)

    Rosenberg, G. D.; Simmons, D. J.

    1985-01-01

    The distribution of Ca, S, Mg and P was mapped within the incisors of Spacelab-3 rats using an electron microprobe. The data indicate that Flight rats maintained in orbit for 7 days have significantly higher Ca/Mg ratios in dentin due to both higher Ca and lower Mg content than in dentin of ground-based Controls. There is no statistical difference in distribution of either P or S within Fligth animals and Controls, but there is clear indication that, for P at least, the reason is the greater variability of the Control data. These results are consistent with those obtained on a previous NASA/COSMOS flight of 18.5 days duration, although they are not pronounced. The results further suggest that continuously growing rat incisors provide useful records of the effects of weightlessness on Ca metabolism.

  12. Transparent intracortical microprobe array for simultaneous spatiotemporal optical stimulation and multichannel electrical recording.

    PubMed

    Lee, Joonhee; Ozden, Ilker; Song, Yoon-Kyu; Nurmikko, Arto V

    2015-12-01

    Optogenetics, the selective excitation or inhibition of neural circuits by light, has become a transformative approach for dissecting functional brain microcircuits, particularly in in vivo rodent models, owing to the expanding libraries of opsins and promoters. Yet there is a lack of versatile devices that can deliver spatiotemporally patterned light while performing simultaneous sensing to map the dynamics of perturbed neural populations at the network level. We have created optoelectronic actuator and sensor microarrays that can be used as monolithic intracortical implants, fabricated from an optically transparent, electrically highly conducting semiconductor ZnO crystal. The devices can perform simultaneous light delivery and electrical readout in precise spatial registry across the microprobe array. We applied the device technology in transgenic mice to study light-perturbed cortical microcircuit dynamics and their effects on behavior. The functionality of this device can be further expanded to optical imaging and patterned electrical microstimulation. PMID:26457862

  13. Study of ancient Islamic gilded pieces combining PIXE-RBS on external microprobe with sem images

    NASA Astrophysics Data System (ADS)

    Ynsa, M. D.; Chamón, J.; Gutiérrez, P. C.; Gomez-Morilla, I.; Enguita, O.; Pardo, A. I.; Arroyo, M.; Barrio, J.; Ferretti, M.; Climent-Font, A.

    2008-07-01

    Numerous metallic objects with very aesthetic and technological qualities have been recovered by archaeological excavations. Adequate processes of restoration and conservation treatments require the accurate determination of the elemental composition and distribution within the objects, as well as the identification of the nature and distribution of the corrosion products. Ideally the identification method should cause no alteration in the sample. In this work, different archaeological pieces with a gilded look have been characterized using simultaneously PIXE and RBS at the CMAM external microprobe in order to study the gilding metalworking done in the Iberian Peninsula during the Middle Ages. The gold layer thickness and its elemental concentrations of Ag, Au and Hg were determined by both techniques and compared with the scanning electron microscopy images obtained for some fragments of pieces.

  14. An Ion Microprobe Study of Fractionated Sulfur Isotopes in Hydrothermal Sulfides of the Kaidun Meteorite Breccia

    NASA Astrophysics Data System (ADS)

    McSween, H. Y., Jr.; Riciputi, L. R.; Paterson, B. A.

    1996-03-01

    The Kaidun breccia contains diverse clasts of enstatite and carbonaceous chondrite, identified by their petrography and oxygen isotopic compositions. One distinctive lithology, classified as CM1 to reflect its CM parentage and highly altered state, contains texturally unusual pyrrhotite needles wrapped in sheaths of phyllosilicate, as well as aggregates and crosscutting veins of pentlandite. The unique textures and associated alteration minerals (serpentine, saponite, melanite garnet, framboidal magnetite) indicate that these sulfides formed in a precursor parent body by reactions with hydrothermal fluids at temperatures as high as 450 degrees C . The alteration conditions recorded by these clasts are extreme in comparison to other carbonaceous chondrites, and coated, jackstraw pyrrhotites are unknown from other meteorites. Thus, it is important to document the reaction products as completely as possible. Here we report the results of in situ analyses of sulfur isotopes in Kaidun pyrrhotite and pentlandite, obtained using a Cameca ims-4f ion microprobe.

  15. Analysis of Nuclear RNA Interference (RNAi) in Human Cells by Subcellular Fractionation and Argonaute Loading

    PubMed Central

    Gagnon, Keith T.; Li, Liande; Janowski, Bethany A.; Corey, David R.

    2014-01-01

    RNA interference (RNAi) is well known for its ability to regulate gene expression in the cytoplasm of mammalian cells. In mammalian cell nuclei, however, the impact of RNAi has remained more controversial. A key technical hurdle has been a lack of optimized protocols for the isolation and analysis of cell nuclei. Here we describe a simplified protocol for nuclei isolation from cultured cells that incorporates a method for obtaining nucleoplasmic and chromatin fractions and removing cytoplasmic contamination. Cell fractions can then be used to detect the presence and activity of RNAi factors in the nucleus. We present a protocol for investigating an early step in RNAi, Argonaute protein loading with small RNAs, which is enabled by our improved extract preparations. These protocols facilitate characterization of nuclear RNAi and can be applied to the analysis of other nuclear proteins and pathways. From cellular fractionation to analysis of Argonaute loading results, this protocol takes 4–6 d to complete. PMID:25079428

  16. Exploration of high-dimensional scalar function for nuclear reactor safety analysis and visualization

    SciTech Connect

    Maljovec, D.; Wang, B.; Pascucci, V.; Bremer, P. T.; Pernice, M.; Mandelli, D.; Nourgaliev, R.

    2013-07-01

    The next generation of methodologies for nuclear reactor Probabilistic Risk Assessment (PRA) explicitly accounts for the time element in modeling the probabilistic system evolution and uses numerical simulation tools to account for possible dependencies between failure events. The Monte-Carlo (MC) and the Dynamic Event Tree (DET) approaches belong to this new class of dynamic PRA methodologies. A challenge of dynamic PRA algorithms is the large amount of data they produce which may be difficult to visualize and analyze in order to extract useful information. We present a software tool that is designed to address these goals. We model a large-scale nuclear simulation dataset as a high-dimensional scalar function defined over a discrete sample of the domain. First, we provide structural analysis of such a function at multiple scales and provide insight into the relationship between the input parameters and the output. Second, we enable exploratory analysis for users, where we help the users to differentiate features from noise through multi-scale analysis on an interactive platform, based on domain knowledge and data characterization. Our analysis is performed by exploiting the topological and geometric properties of the domain, building statistical models based on its topological segmentations and providing interactive visual interfaces to facilitate such explorations. We provide a user's guide to our software tool by highlighting its analysis and visualization capabilities, along with a use case involving data from a nuclear reactor safety simulation. (authors)

  17. Exploration of High-Dimensional Scalar Function for Nuclear Reactor Safety Analysis and Visualization

    SciTech Connect

    Dan Maljovec; Bei Wang; Valerio Pascucci; Peer-Timo Bremer; Michael Pernice; Robert Nourgaliev

    2013-05-01

    The next generation of methodologies for nuclear reactor Probabilistic Risk Assessment (PRA) explicitly accounts for the time element in modeling the probabilistic system evolution and uses numerical simulation tools to account for possible dependencies between failure events. The Monte-Carlo (MC) and the Dynamic Event Tree (DET) approaches belong to this new class of dynamic PRA methodologies. A challenge of dynamic PRA algorithms is the large amount of data they produce which may be difficult to visualize and analyze in order to extract useful information. We present a software tool that is designed to address these goals. We model a large-scale nuclear simulation dataset as a high-dimensional scalar function defined over a discrete sample of the domain. First, we provide structural analysis of such a function at multiple scales and provide insight into the relationship between the input parameters and the output. Second, we enable exploratory analysis for users, where we help the users to differentiate features from noise through multi-scale analysis on an interactive platform, based on domain knowledge and data characterization. Our analysis is performed by exploiting the topological and geometric properties of the domain, building statistical models based on its topological segmentations and providing interactive visual interfaces to facilitate such explorations. We provide a user’s guide to our software tool by highlighting its analysis and visualization capabilities, along with a use case involving dataset from a nuclear reactor safety simulation.

  18. Cellular and Nuclear Alignment Analysis for Determining Epithelial Cell Chirality.

    PubMed

    Raymond, Michael J; Ray, Poulomi; Kaur, Gurleen; Singh, Ajay V; Wan, Leo Q

    2016-05-01

    Left-right (LR) asymmetry is a biologically conserved property in living organisms that can be observed in the asymmetrical arrangement of organs and tissues and in tissue morphogenesis, such as the directional looping of the gastrointestinal tract and heart. The expression of LR asymmetry in embryonic tissues can be appreciated in biased cell alignment. Previously an in vitro chirality assay was reported by patterning multiple cells on microscale defined geometries and quantified the cell phenotype-dependent LR asymmetry, or cell chirality. However, morphology and chirality of individual cells on micropatterned surfaces has not been well characterized. Here, a Python-based algorithm was developed to identify and quantify immunofluorescence stained individual epithelial cells on multicellular patterns. This approach not only produces results similar to the image intensity gradient-based method reported previously, but also can capture properties of single cells such as area and aspect ratio. We also found that cell nuclei exhibited biased alignment. Around 35% cells were misaligned and were typically smaller and less elongated. This new imaging analysis approach is an effective tool for measuring single cell chirality inside multicellular structures and can potentially help unveil biophysical mechanisms underlying cellular chiral bias both in vitro and in vivo. PMID:26294010

  19. Resonant nuclear reaction analysis with high depth resolution

    NASA Astrophysics Data System (ADS)

    Kul'ment'ev, A. I.; Storizhko, V. E.; Zabashta, O. I.

    1994-03-01

    This paper discusses the potential of the resonant NRA technique for measuring the impurity depth profiles. An integrated program package is developed for analysis of the experimental data with high depth resolution. The input information for the package consists of the experimental yield from the impurity reaction selected. The impurity profile can be obtained by solving either a direct or an inverse problem. In the former case the simulated yield from the assigned profile is fitted to the experimental yield. In the latter case the depth profile is obtained by solving the theoretical yield equation. Since the latter procedure is an incorrect problem, we used Tikhonov's regularization method. This approach allows a correct inclusion of the experimental yield errors as well as of the assumptions made in the model describing the incident ion beam interaction with the material. The equation for the yield is derived taking into account the energy distribution of the initial beam, energy loss straggling, resonance width and Doppler effect. The package of programs is menu-driven with a friendly user interface and possibilities of visual representation, which makes the spectrum processing procedure simple and easy even to an unexperienced user. The computational system permits convenient selection of a certain reaction with an arbitrary shape of the resonance, selection of the beam-material interaction and energy loss straggling model and allows the processing of the spectra from a single or several simultaneously excited resonances.

  20. An X-Ray Microprobe for In-Situ Stone and Wood Characterization

    NASA Astrophysics Data System (ADS)

    Lovoi, P.; Asmus, J. F.

    NonDestructive Testing (NDT) has become an essential ingredient in the conservation of artworks and in the preservation of historic buildings. In many instances it is necessary to characterize the underlying strata of an artistic or historic object in order to plan technical conservation measures, to understand its history, to authenticate it, or to search for hidden features. X-ray and gamma-ray radiography as well as infrared imaging have been ubiquitous in conservation practice for generations. Recent decades have also seen the introduction of ultrasonic imaging, thermovision, x-ray fluorescence, neutron activation analyses, holographic interferometry, isotopic and trace element analyses, the electron microprobe, the laser microprobe, microwave impulse radar, eddy current imaging, and fiber-optic imaging. Unfortunately, for mainstream conservation and preservation some of these technologies are too costly or difficult to be implemented in any general way. In other instances penetration is too superficial or signals from the depth of interest are masked by interferences. Nevertheless, sufficiently important problems have arisen to warrant the utilization of each of the above NDT technologies as well as still others. A new diagnostic device has been introduced into the conservation field. Stone characterization analyses are reported using miniature x-ray devices that can be inserted into cracks and holes in specimens of interest. The family of x-ray tubes employed in these studies range in diameter from 1 to 6 mm. Operating voltages up to 50 kV are available. Electrical power and cooling are delivered through a flexible cable that has a bend diameter of less than 3 cm. Thus, it was possible to insert the x-ray tube into small holes and cracks in marble stones. In this manner radiographs of the outer strata of stones (and embedded metal pins) have been produced without having to transmit through the entire thickness of large blocks. It should also be possible to

  1. Fabrication of wear-resistant silicon microprobe tips for high-speed surface roughness scanning devices

    NASA Astrophysics Data System (ADS)

    Wasisto, Hutomo Suryo; Yu, Feng; Doering, Lutz; Völlmeke, Stefan; Brand, Uwe; Bakin, Andrey; Waag, Andreas; Peiner, Erwin

    2015-05-01

    Silicon microprobe tips are fabricated and integrated with piezoresistive cantilever sensors for high-speed surface roughness scanning systems. The fabrication steps of the high-aspect-ratio silicon microprobe tips were started with photolithography and wet etching of potassium hydroxide (KOH) resulting in crystal-dependent micropyramids. Subsequently, thin conformal wear-resistant layer coating of aluminum oxide (Al2O3) was demonstrated on the backside of the piezoresistive cantilever free end using atomic layer deposition (ALD) method in a binary reaction sequence with a low thermal process and precursors of trimethyl aluminum and water. The deposited Al2O3 layer had a thickness of 14 nm. The captured atomic force microscopy (AFM) image exhibits a root mean square deviation of 0.65 nm confirming the deposited Al2O3 surface quality. Furthermore, vacuum-evaporated 30-nm/200-nm-thick Au/Cr layers were patterned by lift-off and served as an etch mask for Al2O3 wet etching and in ICP cryogenic dry etching. By using SF6/O2 plasma during inductively coupled plasma (ICP) cryogenic dry etching, micropillar tips were obtained. From the preliminary friction and wear data, the developed silicon cantilever sensor has been successfully used in 100 fast measurements of 5- mm-long standard artifact surface with a speed of 15 mm/s and forces of 60-100 μN. Moreover, the results yielded by the fabricated silicon cantilever sensor are in very good agreement with those of calibrated profilometer. These tactile sensors are targeted for use in high-aspect-ratio microform metrology.

  2. Heavy ion microprobes: a unique tool for bystander research and other radiobiological applications

    NASA Astrophysics Data System (ADS)

    Voss, K. O.; Fournier, C.; Taucher-Scholz, G.

    2008-07-01

    The risk assessment for low doses of high linear energy transfer (LET) radiation has been challenged by a growing body of experimental evidence showing that non-irradiated bystander cells can receive signals from irradiated cells to elicit a variety of cellular responses. These may be significant for radiation protection but also for radiation therapy using heavy ions. Charged particle microbeams for radiobiological application provide a unique means to address these issues by allowing the precise irradiation of single cells with a counted numbers of ions. Here, we focus specifically on heavy ion microbeam facilities currently in use for biological purposes, describing their technical features and biological results. Typically, ion species up to argon are used for targeted biological irradiation at the vertically collimated microbeam at JAEA (Takasaki, Japan). At the SNAKE microprobe in Munich, mostly oxygen ions have been used in a horizontal focused beam line for cell targeting. At GSI (Darmstadt), a horizontal microprobe with a focused beam for defined targeting using ion species up to uranium is operational. The visualization of DNA damage response proteins relocalizing to defined sites of ion traversal has been accomplished at the three heavy ion microbeam facilities described above and is used to study mechanistic aspects of heavy ion effects. However, bystander studies have constituted the main focus of biological applications. While for cell inactivation and effects on cell cycle progression a response of non-targeted cells has been described at JAEA and GSI, respectively, in part controversial results have been obtained for the induction of DNA damage measured by double-strand formation or at the cytogenetic level. The results emphasize the influence of the cellular environment, and standardization of experimental conditions for cellular studies at different facilities as well as the investigation of bystander effects in tissue will be the aims of future

  3. An Analysis of Nuclear Related Technician Manpower in Western States for the Region Served by the Western Interstate Nuclear Board.

    ERIC Educational Resources Information Center

    Blair, Larry M.; Barker, Larry

    The study presents the results of a survey of current (1975) and projected near-future (1975 through 1977) labor market trends for nuclear-related technicians in the 12-State Western Interstate Nuclear Region Board (WINB) area. The survey covered employers and educators/trainers of nuclear related manpower in private industry, research…

  4. Analysis and consequences of fire inside the ventilation ducts of a nuclear facility

    SciTech Connect

    Briand, A.R.; Laborde, J.C. ); Savornin, J.H.; Tessier, J.L. )

    1989-01-01

    Accident events involving fire are rather frequent and could have a severe effect on the safety of nuclear facilities. Among the fires that have broken out in nuclear plants, several have resulted from ignition of dust deposited inside the ventilation ducts and on the high-efficiency particulate air (HEPA) filters. The BEATRICE test facility has been designed and built at a French nuclear studies center to enable the analysis and consequences of these types of fires to be evaluated. The associated experimental program is aimed at characterizing the fire (fire spread, aerosols formed), determining and simulating the temperature profiles along the duct (thermal losses evaluation by the pipette code), and evaluating the challenge and behavior of the associated HEPA filters (efficiency, contamination release, etc.). The tests performed in this study contributed to improvements in the basic knowledge about fires inside ventilation ducts and define the associated strategies (ventilation control, filters protection, etc.).

  5. An analysis of three nuclear events in P-Tunnel

    SciTech Connect

    Fourney, W.L.; Dick, R.D.; Taylor, S.R.; Weaver, T.A.

    1994-05-03

    This report examines experimental results obtained from three P Tunnel events -- Mission Cyber, Disko Elm, and Distant Zenith. The objective of the study was to determine if there were any differences in the explosive source coupling for the three events. It was felt that Mission Cyber might not have coupled well because the ground motions recorded for that event were much lower than expected based on experience from N Tunnel. Detailed examination of the physical and chemical properties of the tuff in the vicinity of each explosion indicated only minor differences. In general, the core samples are strong and competent out to at least 60 m from each working point. Qualitative measures of core sample strength indicate that the strength of the tuff near Mission Cyber may be greater than indicated by results of static testing. Slight differences in mineralogic content and saturation of the Mission Cyber tuff were noted relative to the other two tests, but probably would not result in large differences in ground motions. Examination of scaled free-field stress and acceleration records collected by Sandia National Laboratory (SNL) indicated that Disko Elm showed the least scatter and Distant Zenith the most scatter. Mission Cyber measurements tend to lie slightly below those of Distant Zenith, but still within two standard deviations. Analysis of regional seismic data from networks operated by Lawrence Livermore National Laboratory (LLNL) and SNL also show no evidence of Mission Cyber coupling low relative to the other two events. The overall conclusion drawn from the study is that there were no basic differences in the way that the explosions coupled to the rock.

  6. High-resolution time and spatial imaging of tobacco and its pyrolysis products during a cigarette puff by microprobe sampling photoionisation mass spectrometry.

    PubMed

    Hertz-Schünemann, R; Ehlert, S; Streibel, T; Liu, C; McAdam, K; Baker, R R; Zimmermann, R

    2015-03-01

    The time- and space-resolved chemical signatures of gases and vapours formed in solid-state combustion processes are difficult to examine using recent analytical techniques. A machine-smoked cigarette represents a very reproducible model system for dynamic solid-state combustion. By using a special sampling system (microprobe unit) that extracts the formed gases from inside of the burning cigarette, which is coupled to a photoionisation mass spectrometer, it was possible to study the evolution of organic gases during a 2-s cigarette puff. The concentrations of various pyrolysis and combustion products such as 1,3-butadiene, toluene, acetaldehyde and phenol were monitored on-line at different sampling points within cigarettes. A near-microscopic-scale spatial resolution and a 200-ms time resolution were achieved. Finally, the recorded information was combined to generate time-resolved concentration maps, showing the formation and destruction zones of the investigated compounds in the burning cigarette. The combustion zone at the tip of cigarette, where e.g. 1,3-butadiene is predominately formed, was clearly separable from the pyrolysis zones. Depending on the stability of the precursor (e.g. lignin or cellulose), the position of pyrolytic formation varies. In conclusion, it was demonstrated that soft photoionisation mass spectrometry in conjunction with a microprobe sampling device can be used for time- and space-resolved analysis of combustion and pyrolysis reactions. In addition to studies on the model cigarette, further model systems may be studied with this approach. This may include further studies on the combustion of biomass or coal chunks, on heterogeneously catalysed reactions or on spray, dust and gas combustion processes. PMID:25627787

  7. Microscopic analysis of fusion hindrance in heavy nuclear systems

    NASA Astrophysics Data System (ADS)

    Washiyama, Kouhei

    2015-06-01

    Background: Heavy-ion fusion reactions involving heavy nuclei at energies around the Coulomb barrier exhibit fusion hindrance, where the probability of compound nucleus formation is strongly hindered compared with that in light- and medium-mass systems. The origin of this fusion hindrance has not been well understood from a microscopic point of view. Purpose: I analyze the fusion dynamics in heavy systems by a microscopic reaction model in order to understand the origin of the fusion hindrance. Method: I employ the time-dependent Hartree-Fock (TDHF) theory as a microscopic reaction model. I extract the nucleus-nucleus potential and energy dissipation by the method combining TDHF dynamics of the entrance channel of fusion reactions with a one-dimensional Newton equation including a dissipation term. Then, I analyze the origin of the fusion hindrance using the properties of the extracted potential and energy dissipation. Results: I obtain finite extra-push energies for heavy systems from TDHF simulations, which agree with experimental observations. Extracted nucleus-nucleus potentials show monotonic increase as the relative distance of two nuclei decreases, which induces the disappearance of an ordinary barrier structure of the nucleus-nucleus potential. This property is different from those in light- and medium-mass systems and from density-constraint TDHF calculations. Extracted friction coefficients show sizable energy dependence and universal value of their magnitude, which are rather similar to those in light- and medium-mass systems. Using these properties, I analyze the origin of the fusion hindrance and find that contribution of the increase in potential to the extra-push energy is larger than that of the accumulated dissipation energy in most systems studied in this article. Conclusions: I find that the nucleus-nucleus potentials extracted in heavy systems show a specific property, which is not observed in light- and medium-mass systems. By the analysis of

  8. Modal seismic analysis of a nuclear power plant control panel and comparison with SAP 4

    NASA Technical Reports Server (NTRS)

    Pamidi, M. R.; Pamidi, P. R.

    1976-01-01

    The application of NASTRAN to seismic analysis by considering the example of a nuclear power plant control panel was considered. A modal analysis of a three-dimensional model of the panel, consisting of beam and quadri-lateral membrane elements, is performed. Using the results of this analysis and a typical response spectrum of an earthquake, the seismic response of the structure is obtained. ALTERs required to the program in order to compute the maximum modal responses as well as the resultant response are given. The results are compared with those obtained by using the SAP IV computer program.

  9. Dynamic analysis and design considerations for high-level nuclear waste repositories

    SciTech Connect

    Hossain, Q.A.

    1993-09-01

    These proceedings are arranged into six broad categories: general overview of analysis and design; characterization of faulting; characterization of design ground vibratory ground motion; considerations for underground facilities; considerations for surface facilities; and guidelines for instrumentation and monitoring. Discussions are given on the relative merits and inadequacies of state-of-the-art design/analysis practices and methodologies in the seismic and dynamic analysis and design field in relation to high-level nuclear waste repositories. All papers have been processed for inclusion on the data base.

  10. Toward the greening of nuclear energy: A content analysis of nuclear energy frames from 1991 to 2008

    NASA Astrophysics Data System (ADS)

    Miller, Sonya R.

    Framing theory has emerged as one of the predominant theories employed in mass communications research in the 21st century. Frames are identified as interpretive packages for content where some issue attributes are highlighted over other attributes. While framing effects studies appear plentiful, longitudinal studies assessing trends in dominant framing packages and story elements for an issue appear to be less understood. Through content analysis, this study examines dominant frame packages, story elements, headline tone, story tone, stereotypes, and source attribution for nuclear energy from 1991-2008 in the New York Times, USA Today, the Wall Street Journal, and the Washington Post. Unlike many content analysis studies, this study compares intercoder reliability among three indices---percentage agreement, proportional reduction of loss and Scott's Pi. The newspapers represented in this study possess a commonality in the types of dominant frames packages employed. Significant dominant frame packages among the four newspapers include human/health, proliferation, procedural, and marketplace. While the procedural frame package was more likely to appear prior to the 1997 Kyoto Protocol, the proliferation frame packaged was more likely to appear after the Kyoto Protol. Over time, the sustainable frame package demonstrated increased significance. This study is part of the growing literature regarding the function of frames over time.

  11. The applicability of sample collection and analysis in support of nuclear arms control agreements

    SciTech Connect

    McGuire, R.R.

    1995-08-01

    Agreements are being negotiated to halt the spread of nuclear arms both within the declared nuclear weapons states and to states not heretofore declaring their possession. With the verification regime of the recently negotiated Chemical Weapons Convention (CWC) as a model, negotiators are considering variations of on-site inspection as formulas to enhance the assurance of compliance with future agreements. These on-site inspections may be part of a treaty dictated verification regime or one of a set of voluntary {open_quotes}confidence building{close_quotes} measures. In either case, the collection of material samples for analysis could be an integral component of the inspection as it is in the CWC. The following is an assessment of the applicability of sampling and analysis for compliance monitoring nuclear arms control agreements currently envisioned. There are two essentially orthogonal ways of approaching this question of applicability: the consideration of the analytical questions and the consideration of the specifics of the individual agreements. This study is meant to utilize both approaches in examining the possible impact of sampling and analysis on compliance assessment. First attention must be given to technical questions relating to the efficacy of sampling and analysis.

  12. Applications of laser produced ion beams to nuclear analysis of materials

    NASA Astrophysics Data System (ADS)

    Mima, K.; Azuma, H.; Fujita, K.; Yamazaki, A.; Okuda, C.; Ukyo, Y.; Kato, Y.; Arrabal, R. Gonzalez; Soldo, F.; Perlado, J. M.; Nishimura, H.; Nakai, S.

    2012-07-01

    Laser produced ion beams have unique characteristics which are ultra-short pulse, very low emittance, and variety of nuclear species. These characteristics could be used for analyzing various materials like low Z ion doped heavy metals or ceramics. Energies of laser produced ion beam extend from 0.1MeV to 100MeV. Therefore, various nuclear processes can be induced in the interactions of ion beams with samples. The ion beam driven nuclear analysis has been developed for many years by using various electrostatic accelerators. To explore the applicability of laser ion beam to the analysis of the Li ion battery, a proton beam with the diameter of ˜ 1.0 μm at Takasaki Ion Acceleration for Advanced Radiation Application (TIARA), JAEA was used. For the analysis, the PIGE (Particle-Induced Gamma Ray Emission) is used. The proton beam scans over Li battery electrode samples to diagnose Li density in the LiNi0.85Co0.15O2 anode. As the results, PIGE images for Li area density distributions are obtained with the spatial resolution of better than 1.5μm FWHM. By the Li PIGE images, the depth dependence of de-intercalation levels of Li in the anode is obtained. By the POP experiments at TIARA, it is clarified that laser produced ion beam is appropriate for the Li ion battery analysis. 41.85.Lc, 41.75.Jv, 42.62.cf.

  13. Nuclear charge and neutron radii and nuclear matter: Trend analysis in Skyrme density-functional-theory approach

    NASA Astrophysics Data System (ADS)

    Reinhard, P.-G.; Nazarewicz, W.

    2016-05-01

    Background: Radii of charge and neutron distributions are fundamental nuclear properties. They depend on both nuclear interaction parameters related to the equation of state of infinite nuclear matter and on quantal shell effects, which are strongly impacted by the presence of nuclear surface. Purpose: In this work, by studying the correlation of charge and neutron radii, and neutron skin, with nuclear matter parameters, we assess different mechanisms that drive nuclear sizes. Method: We apply nuclear density functional theory using a family of Skyrme functionals obtained by means of optimization protocols, which do not include any radius information. By performing the Monte Carlo sampling of reasonable functionals around the optimal parametrization, we scan all correlations between nuclear matter properties and observables characterizing charge and neutron distributions of spherical closed-shell nuclei 48Ca,208Pb, and 298Fl. Results: By considering the influence of various nuclear matter properties on charge and neutron radii in a multidimensional parameter space of Skyrme functionals, we demonstrate the existence of two strong relationships: (i) between the nuclear charge radii and the saturation density of symmetric nuclear matter ρ0, and (ii) between the neutron skins and the slope of the symmetry energy L . The impact of other nuclear matter properties on nuclear radii is weak or nonexistent. For functionals optimized to experimental binding energies only, proton and neutron radii are found to be weakly correlated due to canceling trends from different nuclear matter characteristics. Conclusion: The existence of only two strong relations connecting nuclear radii with nuclear matter properties has important consequences. First, by requiring that the nuclear functional reproduces the empirical saturation point of symmetric nuclear matter practically fixes the charge (or proton) radii, and vice versa. This explains the recent results of ab initio calculations

  14. Thermal hydraulic design analysis of ternary carbide fueled square-lattice honeycomb nuclear rocket engine

    SciTech Connect

    Furman, Eric M.; Anghaie, Samim

    1999-01-22

    A computational analysis is conducted to determine the optimum thermal-hydraulic design parameters for a square-lattice honeycomb nuclear rocket engine core that will incorporate ternary carbide based uranium fuels. Recent studies at the Innovative Nuclear Space Power and Propulsion Institute (INSPI) have demonstrated the feasibility of processing solid solution, ternary carbide fuels such as (U, Zr, Nb)C, (U, Zr, Ta)C, (U, Zr, Hf)C and (U, Zr, W)C. The square-lattice honeycomb design provides high strength and is amenable to the processing complexities of these ultrahigh temperature fuels. A parametric analysis is conducted to examine how core geometry, fuel thickness and the propellant flow area effect the thermal performance of the nuclear rocket engine. The principal variables include core size (length and diameter) and fuel element dimensions. The optimum core configuration requires a balance between high specific impulse and thrust level performance, and maintaining the temperature and strength limits of the fuel. A nuclear rocket engine simulation code is developed and used to examine the system performance as well as the performance of the main reactor core components. The system simulation code was originally developed for analysis of NERVA-Derivative and Pratt and Whitney XNR-2000 nuclear thermal rockets. The code is modified and adopted to the square-lattice geometry of the new fuel design. Thrust levels ranging from 44,500 to 222,400 N (10,000 to 50,000 lbf) are considered. The average hydrogen exit temperature is kept at 2800 K, which is well below the melting point of these fuels. For a nozzle area ratio of 300 and a thrust chamber pressure of 4.8 Mpa (700 psi), the specific impulse is 930 s. Hydrogen temperature and pressure distributions in the core and the fuel maximum temperatures are calculated.

  15. Monte Carlo analysis of thermochromatography as a fast separation method for nuclear forensics

    SciTech Connect

    Hall, Howard L

    2012-01-01

    Nuclear forensic science has become increasingly important for global nuclear security, and enhancing the timeliness of forensic analysis has been established as an important objective in the field. New, faster techniques must be developed to meet this objective. Current approaches for the analysis of minor actinides, fission products, and fuel-specific materials require time-consuming chemical separation coupled with measurement through either nuclear counting or mass spectrometry. These very sensitive measurement techniques can be hindered by impurities or incomplete separation in even the most painstaking chemical separations. High-temperature gas-phase separation or thermochromatography has been used in the past for the rapid separations in the study of newly created elements and as a basis for chemical classification of that element. This work examines the potential for rapid separation of gaseous species to be applied in nuclear forensic investigations. Monte Carlo modeling has been used to evaluate the potential utility of the thermochromatographic separation method, albeit this assessment is necessarily limited due to the lack of available experimental data for validation.

  16. Microstructural characterization of nuclear-waste ceramics

    SciTech Connect

    Ryerson, F.J.; Clarke, D.R.

    1982-09-22

    Characterization of nuclear waste ceramics requires techniques possessing high spatial and x-ray resolution. XRD, SEM, electron microprobe, TEM and analytical EM techniques are applied to ceramic formulations designed to immobilize both commercial and defense-related reactor wastes. These materials are used to address the strengths and limitations of the techniques above. An iterative approach combining all these techniques is suggested. 16 figures, 2 tables.

  17. Fractal analysis differentiation of nuclear and vascular patterns in hepatocellular carcinomas and hepatic metastasis.

    PubMed

    Streba, C T; Pirici, D; Vere, C C; Mogoantă, L; Comănescu, Violeta; Rogoveanu, I

    2011-01-01

    Hepatocellular carcinoma (HCC) currently represents the fifth most common cancer worldwide, while being the third leading cause of cancer death. Fractal analysis is a novel tool used in quantitative and qualitative image assessment. Vascular patterns and cellular nuclei particularities in tumoral pathology make ideal candidates for this technique. Our aim was to apply fractal analysis in quantifying nuclear chromatin patterns and vascular axels in order to identify differences between images of primary HCC, liver metastasis (LM) and surrounding normal liver tissue. Formalin-fixed, paraffin-embedded tissue sections from 40 cases of HCC and 40 LM of various origins were used. We performed Hematoxylin staining for nuclear chromatin as well as immunohistochemical staining for vascular patterns. High-resolution images were captured; nuclear and vascular morphologies were assessed on binarized skeleton masks using the fractal box counting method. Analysis was performed using the free, public domain Java-based image processing tool, ImageJ, which provided the fractal dimensions (FDs) for each studied element. Statistical analysis was performed using the ANOVA test with Bonferroni post-tests and t-tests for paired samples. Fractal analysis of vascular patterns clearly differentiated between tumoral tissue and normal surrounding tissue (p<0.01). Further analysis of nuclear FDs improved the specificity of these results, providing clear differentiation between pathological and normal tissue (p<0.01). When comparing primary HCC images with metastatic formations, we encountered statistically significant differences in nuclear chromatin assessment. However, blood vessels had a higher FD in primary tumors when compared with liver metastasis (p<0.05) and also allowed for a differentiation between primary liver tumors with and without neurodifferentiation. Fractal analysis represents a potent tool for discriminating between tumoral and non-tumoral tissue images. It provides

  18. Evaluation of soil damping techniques used in soil structure interaction analysis of a nuclear power plant

    SciTech Connect

    Nelson, T.A.

    1982-02-24

    A prediction of dynamic soil properties at the site of a nuclear power plant plays a very important role in the seismic analysis of the facility. Conventional modal analysis procedures can accommodate virtually any range of equivalent elastic soil stiffness which is used to characterize the site. However, high radiation damping associated with energy dissipation in the soil half-space is difficult to accommodate in an elastic modal solution to the dynamic problem. Several methods are available to combine the soil damping with the structural damping in a composite modal damping coefficient. However, even with this convenient representation, the resulting large fractions of critical damping can make modal solutions to the problems suspect. This paper is based on experience gained in this area during studies performed for the Nuclear Regulatory Commission involving seismic analyses of power plants.

  19. NPTool: a simulation and analysis framework for low-energy nuclear physics experiments

    NASA Astrophysics Data System (ADS)

    Matta, A.; Morfouace, P.; de Séréville, N.; Flavigny, F.; Labiche, M.; Shearman, R.

    2016-08-01

    The Nuclear Physics Tool (NPTool) is an open source data analysis and Monte Carlo simulation framework that has been developed for low-energy nuclear physics experiments with an emphasis on radioactive beam experiments. The NPTool offers a unified framework for designing, preparing and analyzing complex experiments employing multiple detectors, each of which may comprise some hundreds of channels. The framework has been successfully used for the analysis and simulation of experiments at facilities including GANIL, RIKEN, ALTO and TRIUMF, using both stable and radioactive beams. This paper details the NPTool philosophy together with an overview of the workflow. The framework has been benchmarked through the comparison of simulated and experimental data for a variety of detectors used in charged particle and gamma-ray spectroscopy.

  20. Analysis of Operation UPSHOT-KNOTHOLE nuclear test NANCY radiological and meteorological data

    SciTech Connect

    Steadman, C.R. Jr.; Kennedy, N.C.; Quinn, V.E.

    1984-07-01

    This report describes the Weather Service Nuclear Support Office (WSNSO) analyses of the radiological and meteorological data collected for the NANCY nuclear test of Operation UPSHOT-KNOTHOLE. Inconsistencies in the radiological data and their resolution are discussed. The methods of normalizing the radiological data to a standard time, of converting aerial radiological data to equivalent ground-level values, and of estimating fallout arrival times are presented. The meteorological situation on the event day and a few days following is described. A comparison of the WSNSO fallout analysis with an analysis performed during the 1950's is presented. The radiological data used to derive the WSNSO fallout pattern are tabulated in an appendix.