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Sample records for in-situ gamma spectrometry

  1. Fluence Evaluations For Applications of In Situ Gamma-Ray Spectrometry in Non-Flat Terrain

    SciTech Connect

    Miller, Kevin M.

    1999-02-28

    Evaluations of gamma-ray fluence are made for source geometries that depart from the flat ground geometry that is used in standard applications of in situ spectrometry. Geometries considered include uniform source distributions for soil mounds on top of flat terrain, cylindrical wells, and rectangular trenches. The results indicate that scaling the standard fluence values for flat terrain by the ratio of solid angle subtended by the soil to 2? leads to fluence estimates that are accurate to within a few percent. Practical applications of in situ spectrometry in non-flat terrain also appears to be simplified by the fact that the angular correction factor for a typical coaxial detector in these geometries may typically be about the same as that computed for flat ground.

  2. Monte Carlo simulation by GEANT 4 and GESPECOR of in situ gamma-ray spectrometry measurements.

    PubMed

    Chirosca, Alecsandru; Suvaila, Rares; Sima, Octavian

    2013-11-01

    The application of GEANT 4 and GESPECOR Monte Carlo simulation codes for efficiency calibration of in situ gamma-ray spectrometry was studied. The long computing time required by GEANT 4 prevents its use in routine simulations. Due to the application of variance reduction techniques, GESPECOR is much faster. In this code specific procedures for incorporating the depth profile of the activity were implemented. In addition procedures for evaluating the effect of non-homogeneity of the source were developed. The code was validated by comparison with test simulations carried out with GEANT 4 and by comparison with published results. PMID:23566809

  3. In situ gamma-ray spectrometry in the environment using dose rate spectroscopy

    NASA Astrophysics Data System (ADS)

    Ji, Young-Yong; Kim, Chang-Jong; Chung, Kun Ho; Choi, Hee-Yeoul; Lee, Wanno; Kang, Mun Ja; Park, Sang Tae

    2016-02-01

    In order to expand the application of dose rate spectroscopy to the environment, in situ gamma-ray spectrometry was first conducted at a height of 1 m above the ground to calculate the ambient dose rate and individual dose rate at that height, as well as the radioactivity in the soil layer for the detected gamma nuclides from the dose rate spectroscopy. The reliable results could be obtained by introducing the angular correction factor to correct the G-factor with respect to incident photons distributed in a certain range of angles. The intercomparison results of radioactivity using ISOCS software, an analysis of a sample taken from the soil around a detector, and dose rate spectroscopy had a difference of <20% for 214Pb, 214Bi, 228Ac, 212Bi, 208Tl, and 40K, except for 212Pb with low-energy photons, that is, <300 keV. In addition, the drawback of using dose rate spectroscopy, that is, all gamma rays from a nuclide should be identified to accurately assess the individual dose rate, was overcome by adopting the concept of contribution ratio of the key gamma ray to the individual dose rate of a nuclide, so that it could be accurately calculated by identifying only a key gamma ray from a nuclide.

  4. Spatially-Dependent Measurements of Surface and Near-Surface Radioactive Material Using In situ Gamma Ray Spectrometry (ISGRS) For Final Status Surveys

    SciTech Connect

    J. A. Chapman, A. J. Boerner, E. W. Abelquist

    2006-11-15

    In-situ, high-resolution gamma-ray spectrometry (ISGRS) measurements were conducted at the Oak Ridge Institute for Science and Education (ORISE) field laboratory in Oak Ridge, Tennessee. The purpose of these tests was to provide analytical data for assessing how “fit for use” this technology is for detecting discrete particles in soil.

  5. In situ gamma spectrometry measurements and Monte Carlo computations for the detection of radioactive sources in scrap metal.

    PubMed

    Clouvas, A; Xanthos, S; Takoudis, G; Potiriadis, C; Silva, J

    2005-02-01

    A very limited number of field experiments have been performed to assess the relative radiation detection sensitivities of commercially available equipment used to detect radioactive sources in recycled metal scrap. Such experiments require the cooperation and commitment of considerable resources on the part of vendors of the radiation detection systems and the cooperation of a steel mill or scrap processing facility. The results will unavoidably be specific to the equipment tested at the time, the characteristics of the scrap metal involved in the tests, and to the specific configurations of the scrap containers. Given these limitations, the use of computer simulation for this purpose would be a desirable alternative. With this in mind, this study sought to determine whether Monte Carlo simulation of photon flux energy distributions resulting from a radiation source in metal scrap would be realistic. In the present work, experimental and simulated photon flux energy distributions in the outer part of a truck due to the presence of embedded radioactive sources in the scrap metal load are compared. The experimental photon fluxes are deduced by in situ gamma spectrometry measurements with portable Ge detector and the calculated ones by Monte Carlo simulations with the MCNP code. The good agreement between simulated and measured photon flux energy distributions indicate that the results obtained by the Monte Carlo simulations are realistic. PMID:15650590

  6. Survey of the {sup 137}Cs contamination in Belgium by in-situ gamma spectrometry, a decade after the Chernobyl accident

    SciTech Connect

    Uyttenhove, J.; Pomme, S.; Hardenman, F.; Culot, J.P.

    1997-10-01

    The residual radiocesium concentration, nearly 10 y after the Chernobyl accident, is measured at different sites on the Belgian territory by means of in-situ gamma-spectrometry. A possible link between the rainfall at the beginning of May 1986 and the actual cesium concentration is investigated. The radiological impact of this contamination, even in the most affected regions in the Ardennes, is very small (<6 {mu}Sv y{sup -1}). 6 refs., 4 figs., 1 tab.

  7. Assay for uranium and determination of disequilibrium by means of in situ high resolution gamma-ray spectrometry

    USGS Publications Warehouse

    Tanner, Allan B.; Moxham, Robert M.; Senftle, F.E.

    1977-01-01

    Two sealed sondes, using germanium gamma-ray detectors cooled by melting propane, have been field tested to depths of 79 m in water-filled boreholes at the Pawnee Uranium Mine in Bee Co., Texas. When, used as total-count devices, the sondes are comparable in logging speed and counting rate with conventional scintillation detectors for locating zones of high radioactivity. When used with a multichannel analyzer, the sondes are detectors with such high resolution that individual lines from the complex spectra of the uranium and thorium series can be distinguished. Gamma rays from each group of the uranium series can be measured in ore zones permitting determination of the state of equilibrium at each measurement point. Series of 10-minute spectra taken at 0.3- to 0.5-m intervals in several holes showed zones where maxima from the uranium group and from the 222Rn group were displaced relative to each other. Apparent excesses of 230Th at some locations suggest that uranium-group concentrations at those locations were severalfold greater some tens of kiloyears, ago. At the current state of development a 10-minute count yields a sensitivity of about 80 ppm U308. Data reduction could in practice be accomplished in about 5 minutes. The result is practically unaffected by disequilibrium or radon contamination. In comparison with core assay, high-resolution spectrometry samples a larger volume; avoids problems due to incomplete core recovery, loss of friable material to drilling fluids, and errors in depth and marking; and permits use of less expensive drilling methods. Because gamma rays from the radionuclides are accumulated simultaneously, it also avoids the problems inherent in trying to correlate logs made in separate runs with different equipment. Continuous-motion delayed-gamma activation by a 163-?g 252Cf neutron source attached to the sonde yielded poor sensitivity. A better neutron-activation method, in which the sonde is moved in steps so as to place the detector at the previous activation point, could not be evaluated because of equipment failure.

  8. A Users' Guide for the Computer Program ISDMAP: Analysis and Mapping of In-Situ Gamma-Ray Spectrometry and Soil Sample Data

    SciTech Connect

    Reginatto, Marcel; Bailey, Paul; Shebell, Peter

    2000-11-30

    The computer program ISDMAP was written to analyze data from a set of in situ gamma-ray spectrometry measurements on a grid. It can also do a combined analysis of this type of data and data from soil samples. One well-known difficulty with attempting this type of analysis is that such sets of data can never provide enough information to determine a unique solution. This can be understood intuitively since a finite number of measurements cannot be sufficient to determine a continuous distribution (this observation is not restricted to data collected with the in situ technique, but holds for any set of discrete measurements, such as a series of soil samples). One can, however, restrict to particular types of solutions by requiring that they satisfy other conditions in addition to the measurements, and this is the approach taken by ISDMAP. In ISDMAP, the data are analyzed in a different manner depending on whether the data is from a characterization survey or from a post-remediation survey. The ''characterization'' option creates a map of contamination in surface soil that is smooth and fits the data. The ''post-remediation'' option creates a map with a summary of potential hot spots over a constant background level, providing a map of hot spots that might be ''hidden'' in the data. This report describes the operation of ISDMAP in sufficient detail to allow a user to prepare the necessary input files and run the program. The program requires a PC with DOS or a DOS emulator (most Windows machines have this).

  9. In situ secondary ion mass spectrometry analysis

    SciTech Connect

    Groenewold, G.S.; Applehans, A.D.; Ingram, J.C.; Delmore, J.E.; Dahl, D.A.

    1993-01-01

    The direct detection of tributyl phosphate (TBP) on rocks using molecular beam surface analysis [MBSA or in situ secondary ion mass spectrometry (SIMS)] is demonstrated. Quantities as low as 250 ng were detected on basalt and sandstone with little or no sample preparation. Detection of TBP on soil has proven to be more problematic and requires further study. Ethylenediaminetetraacetic acid (EDTA) is more difficult to detect because it is very reactive with surfaces of interest. Nevertheless, it is possible to detect EDTA if the acidity of the surface is controlled. The detection of EDTA-metal complexes is currently an open question, but evidence is presented for the detection of ions arising from a EDTA-lead complex. Carboxylic acids (i.e., citric, ascorbic, malic, succinic, malonic, and oxalic) give characteristic SIM spectra, but their detection on sample surfaces awaits evaluation.

  10. An improved in situ method for determining depth distributions of gamma-ray emitting radionuclides

    NASA Astrophysics Data System (ADS)

    Benke, Roland R.; Kearfott, Kimberlee J.

    2001-05-01

    In situ gamma-ray spectrometry determines the quantities of radionuclides in some medium with a portable detector. The main limitation of in situ gamma-ray spectrometry lies in determining the depth distribution of radionuclides. This limitation is addressed by developing an improved in situ method for determining the depth distributions of gamma-ray emitting radionuclides in large area sources. This paper implements a unique collimator design with conventional radiation detection equipment. Cylindrically symmetric collimators were fabricated to allow only those gamma-rays emitted from a selected range of polar angles (measured off the detector axis) to be detected. Positioned with its axis normal to surface of the media, each collimator enables the detection of gamma-rays emitted from a different range of polar angles and preferential depths. Previous in situ methods require a priori knowledge of the depth distribution shape. However, the absolute method presented in this paper determines the depth distribution as a histogram and does not rely on such assumptions. Other advantages over previous in situ methods are that this method only requires a single gamma-ray emission, provides more detailed depth information, and offers a superior ability for characterizing complex depth distributions. Collimated spectrometer measurements of buried area sources demonstrated the ability of the method to yield accurate depth information. Based on the results of actual measurements, this method increases the potential of in situ gamma-ray spectrometry as an independent characterization tool in situations with unknown radionuclide depth distributions.

  11. Spatial mapping of soil and radioactivity redistribution at the hillslope scale using in-situ gamma spectrometry, terrestrial laser scanning and RFID tags after the Fukushima nuclear accident fallout.

    NASA Astrophysics Data System (ADS)

    Patin, Jeremy; Onda, Yuichi; Noguchi, Takehiro; Parsons, Anthony

    2013-04-01

    In March 2011, the Fukushima Daiichi Nuclear Power Plant disaster, triggered by the Tohoku earthquake and the consequent tsunami, released a large amount of radionuclides in the environment. To provide a rapid assessment of the soil contamination and its potential redistribution, intensive scientific monitoring has been conducted since July 2011 in our study site, located in the Yamakiya district of Kawamata town, in Fukushima prefecture, Japan, about 37 km from the power plant. In this paper, we summarize and analyze a dataset combining multiple innovative methods deployed inside a 5m x 22m bounded hillslope plot. In addition to runoff volumes and sediments radiocesium concentrations, each major rainfall event was followed by in situ gamma spectrometry measurements. In 2012, to trace the complex behavior of sediments inside the plot, about 300 RFID (Radio-Frequency IDentification) tags representing coarse sediments were scattered and their spatial position was periodically checked using a total station. Finally, several high resolutions Digital Elevation Models were acquired with a terrestrial laser scanner to assess the surface structure and changes. The observed processes at the event scale include interrill and rill erosion, as well as local deposition and remobilization phenomenon. Not only do they directly provide information on the erosion spatio-temporal variability and the associated radionuclides transfers, but combined together they can constitute a solid basis to improve and challenge process-based distributed erosion models.

  12. Uncertainty analysis of in-situ gamma spectrometry measurements of air cleaning filter cartridges and 200 L drums by a HPGe detector.

    PubMed

    Slaninka, Alojz; Slvik, Ondrej; Necas, Vladimr

    2010-01-01

    This work deals with most significant sources of uncertainty in determination of radionuclides massic activity in 200 L drums with radioactive waste (RAW) from decommissioning of nuclear power plant (NPP) A1 and operational air cleaning filters coming from different parts of NPP's ventilation system. It turned out that the most significant source of uncertainty is determination of photo peak detection efficiency, in particular measurement geometry. The detection efficiency of HPGe detector has been determined by calculation using ISOCS software (In Situ Object Counting System) and detector characteristics delivered by the manufacturer (LABSOCS). The detector efficiency is influenced by various factors like measurement geometry, deviation from standard geometry, environmental characteristics, sample properties (density, material composition), used collimator etc. Mentioned factors and their contributions to the uncertainty of detection efficiency and thus to the total uncertainty of massic activity determination have been individually evaluated in the paper. The main part of the work consists of evaluation of maximum uncertainty factor due to presence of hypothetical point source in measurement volume for both types of measurement geometry. PMID:19945884

  13. Indoor and outdoor in situ high-resolution gamma radiation measurements in urban areas of Cyprus.

    PubMed

    Svoukis, E; Tsertos, H

    2007-01-01

    In situ, high-resolution, gamma-ray spectrometry of a total number of 70 outdoor and 20 indoor representative measurements were performed in preselected, common locations of the main urban areas of Cyprus. Specific activities and gamma absorbed dose rates in air due to the naturally occurring radionuclides of (232)Th and (238)U series, and (40)K are determined and discussed. Effective dose rate to the Cyprus population due to terrestrial gamma radiation is derived directly from this work. The results obtained outdoors match very well with those derived previously by high-resolution gamma spectrometry of soil samples, which were collected from the main island bedrock surface. This implies that the construction and building materials in urban areas do not affect the external gamma dose rate; thus they are mostly of local origin. Finally, the indoor/outdoor gamma dose ratio was found to be 1.4 +/- 0.5. PMID:17065195

  14. In situ secondary ion mass spectrometry analysis. 1992 Summary report

    SciTech Connect

    Groenewold, G.S.; Applehans, A.D.; Ingram, J.C.; Delmore, J.E.; Dahl, D.A.

    1993-01-01

    The direct detection of tributyl phosphate (TBP) on rocks using molecular beam surface analysis [MBSA or in situ secondary ion mass spectrometry (SIMS)] is demonstrated. Quantities as low as 250 ng were detected on basalt and sandstone with little or no sample preparation. Detection of TBP on soil has proven to be more problematic and requires further study. Ethylenediaminetetraacetic acid (EDTA) is more difficult to detect because it is very reactive with surfaces of interest. Nevertheless, it is possible to detect EDTA if the acidity of the surface is controlled. The detection of EDTA-metal complexes is currently an open question, but evidence is presented for the detection of ions arising from a EDTA-lead complex. Carboxylic acids (i.e., citric, ascorbic, malic, succinic, malonic, and oxalic) give characteristic SIM spectra, but their detection on sample surfaces awaits evaluation.

  15. In situ mass spectrometry of autoimmune liver diseases.

    PubMed

    Bowlus, Christopher L; Seeley, Erin H; Roder, Joanna; Grigorieva, Julia; Roder, Heinrich; Caprioli, Richard M; Gershwin, Meric

    2011-05-01

    Primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC) and autoimmune hepatitis (AIH) are the major forms of autoimmune liver diseases each characterized by the destruction of a specific liver cell type and the presence of differing auto-antibodies. We took a proteomic approach utilizing in situ matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) to obtain profiles directly from liver samples of patients with PBC, PSC, AIH and controls. The ability to precisely localize the region for acquisition of MALDI MS allowed us to obtain profiles from bile ducts, inflammatory infiltrates and hepatocytes from each biopsy sample. Analysis tools developed to identify peaks and compare peaks across diseases and cell types were used to develop models to classify the samples. Using an initial set of testing samples from PBC patients and controls, we identified unique peaks present in bile ducts, inflammatory infiltrates and hepatocytes that could classify samples in a validation cohort with 88-91% accuracy. Interestingly, profiles of PSC and AIH did not differ significantly from PBC. Identification of proteins in these peaks may represent novel autoantigens or effector molecules. These findings illustrate the potential of a proteomic approach to autoimmune diseases with in situ MALDI MS. PMID:21258365

  16. Monitoring Genetic & Metabolic Potential for In Situ Bioremediation: Mass Spectrometry

    SciTech Connect

    Buchanan, Michelle V.; Hurst, Gregory B.; Lidstrom, Mary E.; Auman, Anne; Britt, Phillip F.; Costello, Andria; Doktycz, Mitchel; Kim, Yongseong

    1999-06-01

    A number of DOE sites are contaminated with dense non-aqueous phase liquids (DNAPLs) such as carbon tetrachloride and trichloroethylene. At many of these sites, microbial bioremediation is an attractive strategy for cleanup, since it has the potential to degrade DNAPLs in situ. A rapid screening method to determine the broad range potential of a site's microbial population for contaminant degradation would greatly facilitate assessment for in situ bioremediation, as well as for monitoring ongoing bioremediation treatment. Current laboratory based treatability methods are cumbersome and expensive. In this project, we are developing methods based on matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) for rapid and accurate detection of polymerase chain reaction (PCR) products from microbial genes involved in biodegradation of pollutants. PCR primers are being developed to amplify DNA sequences that are amenable to MALDI-MS detection. This work will lay the foundation for development of a field-portable MS-based technique for rapid on site assessment and monitoring of bioremediation processes.

  17. Airborne Gamma-Spectrometry in Switzerland

    SciTech Connect

    Butterweck, Gernot; Bucher, Benno; Rybach, Ladislaus

    2008-08-07

    Airborne gamma-spectrometry is able to obtain fast radiological information over large areas. The airborne gamma-spectrometry unit deployed in Switzerland by the Swiss National Emergency Operations Centre (NEOC) consists of a Swiss army Super Puma helicopter equipped with four NaI-Detectors with a total volume of 17 liters, associated electronics and a real-time data evaluation and mapping unit developed by the Swiss Federal Institute of Technology (ETH) and the Paul Scherrer Institut (PSI). The operational readiness of the airborne gamma-spectrometry system is validated in annual exercises of one week duration. Data from 2005 and 2006 exercises are represented in maps of {sup 137}Cs activity concentration for two towns located in southern and western Switzerland. An indicator of man-made radioactivity (MMGC ratio) is demonstrated for an area with four different types of nuclear installations. The intercomparison between airborne gamma-spectrometry and ground measurements showed good agreement between both methods.

  18. Airborne Gamma-Spectrometry in Switzerland

    NASA Astrophysics Data System (ADS)

    Butterweck, Gernot; Bucher, Benno; Rybach, Ladislaus

    2008-08-01

    Airborne gamma-spectrometry is able to obtain fast radiological information over large areas. The airborne gamma-spectrometry unit deployed in Switzerland by the Swiss National Emergency Operations Centre (NEOC) consists of a Swiss army Super Puma helicopter equipped with four NaI-Detectors with a total volume of 17 liters, associated electronics and a real-time data evaluation and mapping unit developed by the Swiss Federal Institute of Technology (ETH) and the Paul Scherrer Institut (PSI). The operational readiness of the airborne gamma-spectrometry system is validated in annual exercises of one week duration. Data from 2005 and 2006 exercises are represented in maps of 137Cs activity concentration for two towns located in southern and western Switzerland. An indicator of man-made radioactivity (MMGC ratio) is demonstrated for an area with four different types of nuclear installations. The intercomparison between airborne gamma-spectrometry and ground measurements showed good agreement between both methods.

  19. Factors influencing in situ gamma-ray measurements

    NASA Astrophysics Data System (ADS)

    Loonstra, E. H.; van Egmond, F. M.

    2009-04-01

    Introduction In situ passive gamma-ray sensors are very well suitable for mapping physical soil properties. In order to make a qualitative sound soil map, high quality input parameters for calibration are required. This paper will focus on the factors that affect the output of in situ passive gamma-ray sensors, the primary source, soil, not taken into account. Factors The gamma-ray spectrum contains information of naturally occurring nuclides 40K, 238U and 232Th and man-made nuclides like 137Cs, as well as the total count rate. Factors that influence the concentration of these nuclides and the count rate can be classified in 3 categories. These are sensor design, environmental conditions and operational circumstances. Sensor design The main elements of an in situ gamma-ray sensor that influence the outcome and quality of the output are the crystal and the spectrum analysis method. Material and size of the crystal determine the energy resolution. Though widely used, NaI crystals are not the most efficient capturer of gamma radiation. Alternatives are BGO and CsI. BGO has a low peak resolution, which prohibits use in cases where man-made nuclides are subject of interest. The material is expensive and prone to temperature instability. CsI is robust compared to NaI and BGO. The density of CsI is higher than NaI, yielding better efficiency, especially for smaller crystal sizes. More volume results in higher energy efficiency. The reduction of the measured spectral information into concentration of radionuclides is mostly done using the Windows analysis method. In Windows, the activities of the nuclides are found by summing the intensities of the spectrum found in a certain interval surrounding a peak. A major flaw of the Windows method is the limited amount of spectral information that is incorporated into the analysis. Another weakness is the inherent use of ‘stripping factors' to account for contributions of radiation from nuclide A into the peak of nuclide B. This can be overcome using Full Spectrum Analysis (FSA). This method incorporates virtually all data present in the measured gamma spectrum. In FSA, a Chi-squared algorithm is used to fit a set of "Standard Spectra" to the measured spectrum. The uncertainty in the FSA method is at least a factor 2 lower compared to the Windows method. Environmental conditions Environmental conditions can influence the signal output and therefore the quality. In general, the density of the medium through which gamma-radiation travels determines the interaction of the radiation with matter and thus affects the sensor readings. Excluding soil as being the source; water is the most important external factor in this respect. The amount of water in soil will affect the signal. In general, energy loss occurs as water content in soil increases. As a result, the nuclide concentrations will be lower. Monte Carlo simulations show a difference of 16% in nuclide concentration for completely dry and fully saturated sandy soils. Another water related issue is rainfall. With rain radon gas, a product of 238U, will precipitate. This causes spectral noise effects. Snow and fog have the same effect to a minor degree. Another aspect is the openness of soil. From experience we know that the concentration of 40K differs if soil is tilled. Finally, on earth there is always radioactive noise present from the galaxy. The "Standard Spectra" used in the FSA method can take noise and geometric effects into account. Operational circumstances During a survey an operator should be aware of the effects of driving speed and measurement height. In general, a larger crystal has better energy efficiency and is therefore more suitable for high speed. E.g. a 70 x 150 mm CsI crystal provides qualitative satisfactory output for soil mapping up to 10 km/hr. Sample locations, however, are best measured during a longer period (3 to 5 minutes). The measurement height affects the measurement resolution; the lower the sensor, the smaller the measured area. In addition, Monte Carlo simulations show that the mass of the survey vehicle has to be taken into account. A large tractor e.g. can lead to spectral shape disruptions of 5 to 10%. Conclusion Several factors can effect the measured concentrations of radioactive nuclides. Potential users should take mentioned factors into account in respect to their needs when building and applying gamma-ray sensors. For purposes of soil mapping the use of FSA method is preferred, as it incorporates several disturbing factors. This allows the user to create a consistent dataset which will lead to a better understanding of the relation between nuclide concentrations and physical soil properties.

  20. Demonstration of a collimated in situ method for determining depth distributions using γ-ray spectrometry

    NASA Astrophysics Data System (ADS)

    Benke, Roland R.; Kearfott, Kimberlee J.

    2002-04-01

    In situ γ-ray spectrometry uses a portable detector to quantify radionuclides in materials. The main shortcoming of in situ γ-ray spectrometry has been its inability to determine radionuclide depth distributions. Novel collimator designs were paired with a commercial in situ γ-ray spectrometry system to overcome this limitation for large area sources. Positioned with their axes normal to the material surface, the cylindrically symmetric collimators limited the detection of unattenuated γ-rays from a selected range of polar angles (measured off the detector axis). Although this approach does not alleviate the need for some knowledge of the γ-ray attenuation characteristics of the materials being measured, the collimation method presented in this paper represents an absolute method that determines the depth distribution as a histogram, while other in situ methods require a priori knowledge of the depth distribution shape. Other advantages over previous in situ methods are that this method does not require multiple γ-ray emission energies, provides the capability for characterizing complex depth distributions. The disadvantages are that collimation adds weight to the in situ system and increases the counting time by reducing the detector's field of view. Using a high-purity germanium spectrometry system, collimated in situ measurements of large area sources buried in attenuating materials were performed in laboratory settings and demonstrated the method's capability to yield accurate depth information.

  1. MONITORING GENETIC & METABOLIC POTENTIAL FOR IN SITU BIOREMEDIATION: MASS SPECTROMETRY

    EPA Science Inventory

    A number of DOE sites are contaminated with mixtures of dense non-aqueous phase liquids (DNAPLs) such as carbon tetrachloride, chloroform, perchloroethylene, and trichloroethylene. At many of these sites, in situ microbial bioremediation is an attractive strategy for cleanup, sin...

  2. Mass spectrometry imaging for in situ kinetic histochemistry

    PubMed Central

    Louie, Katherine B.; Bowen, Benjamin P.; McAlhany, Stephanie; Huang, Yurong; Price, John C.; Mao, Jian-hua; Hellerstein, Marc; Northen, Trent R.

    2013-01-01

    Tissues are composed of diverse cell subpopulations each with distinct metabolic characteristics that influence overall behavior. Unfortunately, traditional histopathology imaging techniques are blind to the spatially ordered metabolic dynamics within tissue. While mass spectrometry imaging enables spatial mapping of molecular composition, resulting images are only a static snapshot in time of molecules involved in highly dynamic processes; kinetic information of flux through metabolic pathways is lacking. To address this limitation, we developed kinetic mass spectrometry imaging (kMSI), a novel technique integrating soft desorption/ionization mass spectrometry with clinically accepted in vivo metabolic labeling of tissue with deuterium to generate images of kinetic information of biological processes. Applied to a tumor, kMSI revealed heterogeneous spatial distributions of newly synthesized versus pre-existing lipids, with altered lipid synthesis patterns distinguishing region-specific intratumor subpopulations. Images also enabled identification and correlation of metabolic activity of specific lipids found in tumor regions of varying grade. PMID:23584513

  3. Mass spectrometry imaging for in situ kinetic histochemistry.

    PubMed

    Louie, Katherine B; Bowen, Benjamin P; McAlhany, Stephanie; Huang, Yurong; Price, John C; Mao, Jian-hua; Hellerstein, Marc; Northen, Trent R

    2013-01-01

    Tissues are composed of diverse cell subpopulations each with distinct metabolic characteristics that influence overall behavior. Unfortunately, traditional histopathology imaging techniques are 'blind' to the spatially ordered metabolic dynamics within tissue. While mass spectrometry imaging enables spatial mapping of molecular composition, resulting images are only a static snapshot in time of molecules involved in highly dynamic processes; kinetic information of flux through metabolic pathways is lacking. To address this limitation, we developed kinetic mass spectrometry imaging (kMSI), a novel technique integrating soft desorption/ionization mass spectrometry with clinically accepted in vivo metabolic labeling of tissue with deuterium to generate images of kinetic information of biological processes. Applied to a tumor, kMSI revealed heterogeneous spatial distributions of newly synthesized versus pre-existing lipids, with altered lipid synthesis patterns distinguishing region-specific intratumor subpopulations. Images also enabled identification and correlation of metabolic activity of specific lipids found in tumor regions of varying grade. PMID:23584513

  4. Monitoring genetic and metabolic potential for in situ bioremediation: Mass spectrometry. 1997 annual progress report

    SciTech Connect

    Buchanan, M.V.; Hurst, G.B.; Britt, P.F.; McLuckey, S.A.; Doktycz, M.J.

    1997-09-01

    'A number of US Department of Energy (DOE) sites are contaminated with mixtures of dense non-aqueous phase liquids (DNAPLs) such as carbon tetrachloride, chloroform,. perchloroethylene, and trichloroethylene. At many of these sites, in situ microbial bioremediation is an attractive strategy for cleanup because it has the potential to degrade DNAPLs in situ without producing toxic byproducts. A rapid screening method to determine the broad range metabolic and genetic potential for contaminant degradation would greatly reduce the cost and time involved in assessment for in situ bioremediation as well as for monitoring ongoing bioremediation treatment. In this project, the ORNL Organic Mass Spectrometry (OMS) group is developing mass-spectrometry-based methods to screen for the genetic and metabolic potential for assessment and monitoring of in situ bioremediation of DNAPLs. In close collaboration, Professor Mary Lidstrom''s group at the University of Washington is identifying short DNA sequences related to microbial processes involved in the biodegradation of pollutants. This work will lay the foundation for development of a field-portable mass-spectrometry-based technique for rapid assessment and monitoring of bioremediation processes on site.'

  5. Review of in situ derivatization techniques for enhanced bioanalysis using liquid chromatography with mass spectrometry.

    PubMed

    Baghdady, Yehia Z; Schug, Kevin A

    2016-01-01

    Accurate and specific analysis of target molecules in complex biological matrices remains a significant challenge, especially when ultra-trace detection limits are required. Liquid chromatography with mass spectrometry is often the method of choice for bioanalysis. Conventional sample preparation and clean-up methods prior to the analysis of biological fluids such as liquid-liquid extraction, solid-phase extraction, or protein precipitation are time-consuming, tedious, and can negatively affect target recovery and detection sensitivity. An alternative or complementary strategy is the use of an off-line or on-line in situ derivatization technique. In situ derivatization can be incorporated to directly derivatize target analytes in their native biological matrices, without any prior sample clean-up methods, to substitute or even enhance the extraction and preconcentration efficiency of these traditional sample preparation methods. Designed appropriately, it can reduce the number of sample preparation steps necessary prior to analysis. Moreover, in situ derivatization can be used to enhance the performance of the developed liquid chromatography with mass spectrometry-based bioanalysis methods regarding stability, chromatographic separation, selectivity, and ionization efficiency. This review presents an overview of the commonly used in situ derivatization techniques coupled to liquid chromatography with mass spectrometry-based bioanalysis to guide and to stimulate future research. PMID:26496130

  6. Mass Spectrometry Guided In Situ Proteolysis to Obtain Crystals for X-ray Structure Determination

    SciTech Connect

    Gheyi, Tarun; Rodgers, Logan; Romero, Richard; Sauder, J. Michael; Burley, Stephen K.

    2012-04-30

    A strategy for increasing the efficiency of protein crystallization/structure determination with mass spectrometry has been developed. This approach combines insights from limited proteolysis/mass spectrometry and crystallization via in situ proteolysis. The procedure seeks to identify protease-resistant polypeptide chain segments from purified proteins on the time-scale of crystal formation, and subsequently crystallizing the target protein in the presence of the optimal protease at the right relative concentration. We report our experience with 10 proteins of unknown structure, two of which yielded high-resolution X-ray structures. The advantage of this approach comes from its ability to select only those structure determination candidates that are likely to benefit from application of in situ proteolysis, using conditions most likely to result in formation of a stable proteolytic digestion product suitable for crystallization.

  7. Mass spectrometry guided in situ proteolysis to obtain crystals for X-ray structure determination.

    PubMed

    Gheyi, Tarun; Rodgers, Logan; Romero, Richard; Sauder, J Michael; Burley, Stephen K

    2010-10-01

    A strategy for increasing the efficiency of protein crystallization/structure determination with mass spectrometry has been developed. This approach combines insights from limited proteolysis/mass spectrometry and crystallization via in situ proteolysis. The procedure seeks to identify protease-resistant polypeptide chain segments from purified proteins on the time-scale of crystal formation, and subsequently crystallizing the target protein in the presence of the optimal protease at the right relative concentration. We report our experience with 10 proteins of unknown structure, two of which yielded high-resolution X-ray structures. The advantage of this approach comes from its ability to select only those structure determination candidates that are likely to benefit from application of in situ proteolysis, using conditions most likely to result in formation of a stable proteolytic digestion product suitable for crystallization. PMID:20685133

  8. Comparison of in situ and laboratory gamma spectroscopy of natural radionuclides in desert soil.

    PubMed

    Benke, R R; Kearfott, K J

    1997-08-01

    In situ and laboratory gamma spectroscopy were used to characterize natural background levels of radiation in the soil at eight sites around the Yucca Mountain Range. The purpose of this practical field analysis was to determine if published empirical in situ calibration factors would yield accurate quantitative specific activities (Bq kg(-1)) in a desert environment. Corrections were made to the in situ calibration factors to account for the on-axis response of a detector with a thin beryllium end window. The in situ gamma spectroscopy results were compared to laboratory gamma spectroscopy of soil samples gathered from each site. Five natural radionuclides were considered: 40K, 214Pb, 214Bi, 208Tl, and 228Ac. The in situ determined specific activities were consistently within +/-15% of the laboratory soil sample results. A quantitative discussion of the factors contributing to the uncertainty in the in situ and laboratory results is included. Analysis on the specific activity data using statistical hypothesis tests determined that three nuclides, 214Pb, 214Bi, and 228Ac showed a weak site dependence while the other two nuclides, 40K and 208Tl, did not exhibit a site dependence. Differing radiation background levels from site to site along with in situ and laboratory uncertainties in excess of 10% are two factors that account for the weak site dependence. Despite the good correlation between data, it was recommended that the in situ detector be calibrated by a detector-specific Monte Carlo code which would accurately model more complex geometries and source distributions. PMID:9228170

  9. A Hybrid X-Gamma Detector for In-situ Planetary Science

    NASA Astrophysics Data System (ADS)

    Skidmore, Michelle; Ambrosi, Richard; Nelms, Nick; Ball, Andrew; Wolters, Stephen; Simon, Herv; Bannister, Nigel

    A new generation of hybrid X-ray and gamma ray detectors is being developed by the University of Leicester in collaboration with Eurorad, France. This type of detector is being developed for surface and subsurface in-situ planetary science applications. Gamma rays generated from neutron-induced interactions with a planetary surface as well as emissions from radioactive elements will allow an X-Gamma detector to analyze the bulk composition of the surface and sub-surface of any planetary body, the depth of analysis being dependent on the configuration of the instrumented probe. Gamma backscatter densitometry is a non-destructive in-situ method for measuring the bulk density of surrounding material that exploits the Compton effect. The bulk density can be used to measure heat flow through a planetary body as a function of depth. X-Gamma, used in conjunction with a small gamma ray source may be used to measure the bulk density of a planetary surface as well as the bulk composition. The use of such a detector on a planetary surface could aid in our understanding of the evolution of a planetary body and enable us to complement orbital gamma ray measurements by mapping the gamma ray emissions at a higher spatial resolution. In-situ analysis could aid in detecting trace elements that have not been previously detected by orbital gamma ray spectrometers. In this study we describe the progress made on the X-Gamma project, including the characterization of several possible gamma ray detectors for the hybrid detector. The results obtained during several experimental detector test campaigns at the neutron beam facility, FRM-2 in Munich, Germany will also be reported.

  10. EML Gamma Spectrometry Data Evaluation Program

    SciTech Connect

    Decker, Karin M.

    2001-01-01

    This report presents the results of the analyses for the third EML Gamma Spectrometry Data Evaluation Program (October 1999). This program assists laboratories in providing more accurate gamma spectra analysis results and provides a means for users of gamma data to assess how a laboratory performed on various types of gamma spectrometry analyses. This is accomplished through the use of synthetic gamma spectra. A calibration spectrum, a background spectrum, and three sample spectra are sent to each participant in the spectral file format requested by the laboratory. The calibration spectrum contains nuclides covering the energy range from 59.5 keV to 1836 keV. The participants are told fallout and fission product nuclides could be present. The sample spectra are designed to test the ability of the software and user to properly resolve multiplets and to identify and quantify nuclides in a complicated fission product spectrum. The participants were asked to report values and uncertainties as Becquerel per sample with no decay correction. Thirty-one sets of results were reported from a total of 60 laboratories who received the spectra. Six foreign laboratories participated. The percentage of the results within 1 of the expected value was 68, 33, and 46 for samples 1, 2, and 3, respectively. From all three samples, 18% of the results were more than 3 from the expected value. Eighty-three (12%) values out of a total of 682 expected results were not reported for the three samples. Approximately 30% of these false negatives were due the laboratories not reporting 144Pr in sample 2 which was present at the minimum detectable activity level. There were 53 false positives reported with 25% of these responses due to problems with background subtraction. The results show improvement in the ability of the software or user to resolve peaks separated by 1 keV. Improvement is still needed either in the analysis report produced by the software or in the review of these results by the users.

  11. Parametric Studies for 233U Gamma Spectrometry

    SciTech Connect

    Scheffing, C.C.; Krichinsky, A.

    2004-01-01

    Quantification of special nuclear material is a necessary aspect to assuring material accountability and is often accomplished using non-destructive gamma spectrometry. For 233U, gamma rays are affected by matrix and packaging attenuation and by a strong Compton continuum from decay products of 232U (inherently found in 233U) that obscure 233U gamma photopeaks. This project, based on current work at the national repository for separated 233U located at Oak Ridge National Laboratory (ORNL), explores the effects of various parameters on the quantification of 233U– including material form and geometry. Using an attenuation correction methodology for calculating the mass of 233U from NDA analysis, a bias of almost 75% less than the actual 233U mass was identified. The source of the bias needs to be understood at a more fundamental level for further use of this quantification method. Therefore, controlled experiments using well characterized packages of 233U were conducted at the repository and are presented in this paper.

  12. Rapid In-Situ Measurement of Gamma Activity in Soil for Environmental Assessment

    NASA Astrophysics Data System (ADS)

    Honeycutt, T. K.

    2003-12-01

    In-situ measurements of gamma radiation in soil are used as a rapid, low-cost, non-intrusive alternative to conventional sampling and analysis methods in the preliminary assessment of environmental impacts to watersheds at the Savannah River Site (SRS). The method resolves the ambient gamma-radiation field near ground surface into background and residual components and provides radionuclide-specific soil activity determination. The efficacy of the method has been evaluated and compares favorably with conventional gamma-PHA soil analyses and aerial survey data. The method has garnered regulatory approval and is being successfully deployed to evaluate the impact of Cs-137 contamination from CERCLA sites.

  13. In situ characterization of hazardous contaminants using prompt gamma neutron activation analysis

    SciTech Connect

    Ruddy, F.H.; Congedo, T.V.; Seidel, J.G.; Gonzalez, J.L.; Weigle, D.H.

    1993-12-31

    Prompt Gamma Neutron Activation Analysis (PGNAA) has been developed for real-time, in situ measurements of contaminant elements in soil. Pulsed neutron activation coupled with state-of-the-art high count rate throughput electronics and time-sequenced gamma ray energy analysis have been used to obtain sensitivities at the trace level for uranium in soil. The results of detailed neutron dosimetry and prompt neutron-induced gamma ray transport measurements carried out using a soil test matrix will be reported. Initial field deployment of the PGNAA system at a former solution uranium mine in Bruni, Texas will also be described.

  14. Planetary Geochemistry Techniques: Probing In-Situ with Neutron and Gamma Rays (PING) Instrument

    NASA Technical Reports Server (NTRS)

    Parsons, A.; Bodnarik, J.; Burger, D.; Evans, L.; Floyd, S.; Lin, L.; McClanahan, T.; Nankung, M.; Nowicki, S.; Schweitzer, J.; Starr, R.; Trombka, J.

    2011-01-01

    The Probing In situ with Neutrons and Gamma rays (PING) instrument is a promising planetary science application of the active neutron-gamma ray technology so successfully used in oil field well logging and mineral exploration on Earth. The objective of our technology development program at NASA Goddard Space Flight Center's (NASA/GSFC) Astrochemistry Laboratory is to extend the application of neutron interrogation techniques to landed in situ planetary composition measurements by using a 14 MeV Pulsed Neutron Generator (PNG) combined with neutron and gamma ray detectors, to probe the surface and subsurface of planetary bodies without the need to drill. We are thus working to bring the PING instrument to the point where it can be flown on a variety of surface lander or rover missions to the Moon, Mars, Venus, asteroids, comets and the satellites of the outer planets.

  15. Novel Equipment for In Situ Alpha Spectrometry with Good Energy Resolution.

    PubMed

    Pllnen, Roy; Turunen, Jani; Karhunen, Tero; Perjrvi, Kari; Siiskonen, Teemu; Wirta, Markus; Turunen, Asko

    2015-12-01

    An approach for in situ alpha spectrometry that allows one to measure the spectra with good energy resolution at ambient air pressure has been developed recently. Here, novel equipment is introduced for in situ measurements. Neither vacuum pumps nor radiochemical sample processing are necessary. Flat and smooth surfaces are ideal sources provided that the radionuclide contamination represents a thin layer on the surface. Other sources, such as air filters or evaporation residues, are also possible. Alpha particle collimation is used to obtain good energy resolution, but the equipment can also be used without collimation. An estimation of the detection efficiency with and without collimation is given using an extended area source containing 241Am. PMID:26509627

  16. Composite mapping experiences in airborne gamma spectrometry.

    PubMed

    Bucher, B

    2014-08-01

    During an international intercomparison exercise of airborne gamma spectrometry held in Switzerland 2007 teams from Germany, France and Switzerland were proving their capabilities. One of the tasks was the composite mapping of an area around Basel. Each team was mainly covering the part of its own country at its own flying procedures. They delivered the evaluated data in a data format agreed in advance. The quantities to be delivered were also defined in advance. Nevertheless, during the process to put the data together a few questions raised: Which dose rate was meant? Had the dose rate to be delivered with or without cosmic contribution? Activity per dry or wet mass? Which coordinate system was used? Finally, the data could be put together in one map. For working procedures in case of an emergency, quantities of interest and exchange data format have to be defined in advance. But the procedures have also to be proved regularly. PMID:24664949

  17. An experimental comparison of in-situ gamma spectrometric methods for quantifying Cs-137 radioactive contamination in the ground

    SciTech Connect

    MacDonald, J.; Gibson, C.J.; Fish, P.J.; Assinder, D.J.

    1999-06-01

    In-situ gamma spectrometry is a potentially powerful method for rapid quantification of radioactive contamination in the ground using an above-ground detector. The accuracy of the technique, however, depends on having information on the activity variation with depth. Three methods have previously been proposed for deriving this information using information obtained in the field. This paper describes these methods and models used to approximate activity-depth distributions and presents an experimental comparison for a range of sites of differing activity concentrations and sources of contamination. It was found that the Lead Plate Method in conjunction with a modified gaussian activity distribution model gave the best results estimating activity concentrations on average to within a factor of 1.5 of the true value.

  18. In situ laser ablation sampling for inductively coupled plasma atomic emission spectrometry

    NASA Astrophysics Data System (ADS)

    Liu, X. R.; Horlick, Gary

    1995-06-01

    In this report an in situ laser ablation system for inductively coupled plasma-atomic emission spectrometry (ICP-AES) is described that eliminates the aerosol transport step associated with conventional laser ablation sample introduction systems. The concept of this system is to place the sample inside the ICP torch immediately below the plasma discharge. This can be accomplished using a direct sample insertion system. The laser is then focused on the sample by a lens placed above the plasma and ablated material is directly injected into the plasma. For ablation with a Q-switched Nd-YAG laser (single pulse) this results in an emission signal that has a duration of about 0.7 ms, in contrast to a conventional ablation system where signal durations are measured in seconds. This translates to a dramatic improvement in sensitivity for the in situ system over a conventional system. Measurement considerations are discussed, results are presented for the analysis of Al and steel samples, and the in situ system is briefly compared with a conventional laser ablation system.

  19. In situ mapping of nutrient uptake in the rhizosphere using nanoscale secondary ion mass spectrometry.

    PubMed

    Clode, Peta L; Kilburn, Matt R; Jones, David L; Stockdale, Elizabeth A; Cliff, John B; Herrmann, Anke M; Murphy, Daniel V

    2009-12-01

    Plant roots and microorganisms interact and compete for nutrients within the rhizosphere, which is considered one of the most biologically complex systems on Earth. Unraveling the nitrogen (N) cycle is key to understanding and managing nutrient flows in terrestrial ecosystems, yet to date it has proved impossible to analyze and image N transfer in situ within such a complex system at a scale relevant to soil-microbe-plant interactions. Linking the physical heterogeneity of soil to biological processes marks a current frontier in plant and soil sciences. Here we present a new and widely applicable approach that allows imaging of the spatial and temporal dynamics of the stable isotope (15)N assimilated within the rhizosphere. This approach allows visualization and measurement of nutrient resource capture between competing plant cells and microorganisms. For confirmation we show the correlative use of nanoscale secondary ion mass spectrometry, and transmission electron microscopy, to image differential partitioning of (15)NH(4)(+) between plant roots and native soil microbial communities at the submicron scale. It is shown that (15)N compounds can be detected and imaged in situ in individual microorganisms in the soil matrix and intracellularly within the root. Nanoscale secondary ion mass spectrometry has potential to allow the study of assimilatory processes at the submicron level in a wide range of applications involving plants, microorganisms, and animals. PMID:19812187

  20. Application of PERALS alpha spectrometry and gamma spectrometry for analysis and investigation of environmental spills at ISL uranium mining projects.

    PubMed

    Borysenko, A; Ostrowski, A; Bellifemine, D; Palmer, G; Haigh, P; Johnston, A

    2014-03-01

    Radiation protection and environmental monitoring in mining requires effective and reliable radionuclide analysis at all stages of the mine project-prior to mining, during operation and through to remediation and decommissioning. The approach presented in this paper was specially developed for the monitoring of radioactive waste resulting from spills during mining and mineral processing operations and uses a combination of high resolution gamma spectrometry, and PERALS alpha spectrometry to identify and reliably quantify the activity of the major members of the U-238 decay chain at activities down to 10 mBq g(-1) by direct radionuclide counting and by assessment of the activity of their decay products. This approach has reduced sample preparation and analysis time while providing effective analysis and quantification of naturally occurring radionuclides in environmental samples. It has been successfully applied to several in situ leach (ISL) mining-related projects involving investigations of process material spill impacts and also to routine environmental monitoring. PMID:24270399

  1. In situ XRF and gamma ray spectrometer for Mars sample return mission

    NASA Technical Reports Server (NTRS)

    Lo, I. Yin; Trombka, Jacob I.; Evans, Larry G.; Squyres, Steven W.

    1988-01-01

    A combined in situ X-ray fluorescence (XRF) and passive gamma ray spectrometer instrument is proposed for the chemical elemental analysis of various Martian surfaces and samples. The combined instrument can be carried on board a rover. The passive gamma ray or the neutron excited gamma ray system would be used to determine the elemental composition of the Martian surface while the rover is in motion. The XRF system would be used to perform analysis either on the Martian surface or on collected samples when the rover is stationary. The latter function is important both in cataloging the collected samples and in the selection of samples to be returned to earth. For both systems, data accumulation time would be on the order of 30 minutes. No sample preparation would be necessary.

  2. Laser-induced shock wave plasma spectrometry using a small chamber designed for in situ analysis

    NASA Astrophysics Data System (ADS)

    Kurniawan, Hendrik; Jie Lie, Tjung; Kagawa, Kiichiro; On Tjia, May

    2000-07-01

    Direct spectrochemical analyses on large bulk samples such as metal plates have been performed by using a small vacuum chamber, which was attached directly to the sample surface through an o-ring. This technique allowed the in situ generation of laser plasma and hence overcome to a good extent the inconvenient and sometime clumsy sample preparation procedure required in Laser-Induced Shock Wave Plasma Spectrometry. Additionally, the presence of the o-ring near the target surface effectively shielded off the surrounding area from the undesirable continuum emission from the primary plasma, and thereby enhanced the detection sensitivity of this technique. Using zinc plate and Pb glass as samples, it was further demonstrated in this experiment that even the time-integrated spectra, obtained by employing an OMA system, still exhibited a lower background than those obtained by ordinary time-resolved Laser-Induced Breakdown Spectroscopy.

  3. Laser Time-of-Flight Mass Spectrometry for Future In Situ Planetary Missions

    NASA Technical Reports Server (NTRS)

    Getty, S. A.; Brinckerhoff, W. B.; Cornish, T.; Ecelberger, S. A.; Li, X.; Floyd, M. A. Merrill; Chanover, N.; Uckert, K.; Voelz, D.; Xiao, X.; Tawalbeh, R.; Glenar, D.; Elsila, J. E.; Callahan, M.

    2012-01-01

    Laser desorption/ionization time-of-flight mass spectrometry (LD-TOF-MS) is a versatile, low-complexity instrument class that holds significant promise for future landed in situ planetary missions that emphasize compositional analysis of surface materials. Here we describe a 5kg-class instrument that is capable of detecting and analyzing a variety of analytes directly from rock or ice samples. Through laboratory studies of a suite of representative samples, we show that detection and analysis of key mineral composition, small organics, and particularly, higher molecular weight organics are well suited to this instrument design. A mass range exceeding 100,000 Da has recently been demonstrated. We describe recent efforts in instrument prototype development and future directions that will enhance our analytical capabilities targeting organic mixtures on primitive and icy bodies. We present results on a series of standards, simulated mixtures, and meteoritic samples.

  4. Monitoring Genetic and Metabolic Potential for In-Situ Bioremediation: Mass Spectrometry

    SciTech Connect

    Buchanan, Michelle V.; Britt, Phillip F.; Doktycz, Mitchel J.; Hurst, Gregory B.; Lidstrom, Mary E.

    2000-06-01

    A number of DOE sites are contaminated with dense non-aqueous phase liquids (DNAPLs) such as carbon tetrachloride and trichloroethylene. At many of these sites, microbial bioremediation is an attractive strategy for cleanup, since it has the potential to degrade DNAPLs in situ. A rapid screening method to determine the broad range potential of a site's microbial population for contaminant degradation would greatly facilitate assessment for in situ bioremediation, as well as for monitoring ongoing bioremediation treatment. Current laboratory-based treatability methods are cumbersome and expensive. In this project, we are developing methods based on matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) for rapid and accurate detection of polymerase chain reaction (PCR) products from microbial genes involved in biodegradation of pollutants. PCR primers are being developed to amplify DNA sequences that are amenable to MALDI-MS detection. This work will lay the foundation for development of a field-portable MS-based technique for rapid on site assessment and monitoring of bioremediation processes.

  5. MALDI Mass Spectrometry Imaging for Visualizing In Situ Metabolism of Endogenous Metabolites and Dietary Phytochemicals

    PubMed Central

    Fujimura, Yoshinori; Miura, Daisuke

    2014-01-01

    Understanding the spatial distribution of bioactive small molecules is indispensable for elucidating their biological or pharmaceutical roles. Mass spectrometry imaging (MSI) enables determination of the distribution of ionizable molecules present in tissue sections of whole-body or single heterogeneous organ samples by direct ionization and detection. This emerging technique is now widely used for in situ label-free molecular imaging of endogenous or exogenous small molecules. MSI allows the simultaneous visualization of many types of molecules including a parent molecule and its metabolites. Thus, MSI has received much attention as a potential tool for pathological analysis, understanding pharmaceutical mechanisms, and biomarker discovery. On the other hand, several issues regarding the technical limitations of MSI are as of yet still unresolved. In this review, we describe the capabilities of the latest matrix-assisted laser desorption/ionization (MALDI)-MSI technology for visualizing in situ metabolism of endogenous metabolites or dietary phytochemicals (food factors), and also discuss the technical problems and new challenges, including MALDI matrix selection and metabolite identification, that need to be addressed for effective and widespread application of MSI in the diverse fields of biological, biomedical, and nutraceutical (food functionality) research. PMID:24957029

  6. EML Gamma Spectrometry Data Evaluation Program

    SciTech Connect

    Decker, Karin M.

    1998-02-28

    This report represents the results of the analyses for the second EML Gamma Spectrometry Data Evaluation Program (August 1997). A calibration spectrum, a background spectrum and three sample spectra were included for each software format as part of the evaluation. The calibration spectrum contained nuclides covering the range from 59.5 keV to 1836 keV. The participants were told fallout and fission product nuclides as well as naturally occurring nuclides could be present. The samples were designed to test the detection and quantification of very low levels of nuclides and the ability of the software and user to properly resolve multiplets. The participants were asked to report values and uncertainties as Becquerel per sample with no decay correction. Twenty-nine sets of results were reported from a total of 70 laboratories who received the spectra. The percentage of the results within 1 F of the expected value was 76, 67, and 55 for samples 1, 2, and 3, respectively. From all three samples, 12% of the results were more than 3 F from the expected value. Sixty-two nuclides out of a total of 580 expected results were not reported for the three samples. Sixty percent of these false negatives were due to nuclides which were present at the minimum detectable activity level. There were 53 false positives reported with 60% of the responses due to problems with background subtraction. The results indicate that the Program is beneficial to the participating laboratories in that it provides them with analysis problems that are difficult to create with spiked samples due to the unavailability of many nuclides and the short half-lives of others. EML will continue its annual distribution, the third is to be held in March 1999.

  7. In situ capture gamma-ray analysis of coal in an oversize borehole

    USGS Publications Warehouse

    Mikesell, J.L.; Dotson, D.W.; Senftle, F.E.; Zych, R.S.; Koger, J.; Goldman, L.

    1983-01-01

    In situ capture gamma-ray analysis in a coal seam using a high resolution gamma-ray spectrometer in a close-fitting borehole has been reported previously. In order to check the accuracy of the method under adverse conditions, similar measurements were made by means of a small-diameter sonde in an oversize borehole in the Pittsburgh seam, Greene County, Pennsylvania. The hole was 5 times the diameter of the sonde, a ratio that substantially increased the contribution of water (hydrogen) to the total spectral count and reduced the size of the sample measured by the detector. The total natural count, the 40K,count, and the intensities of capture gamma rays from Si, Ca, H, and Al were determined as a function of depth above, through, and below the coal seam. From these logs, the depth and width of the coal seam and its partings were determined. Spectra were accumulated in the seam for 1 h periods by using neutron sources of different strengths. From the spectra obtained by means of several 252Cf neutron sources of different sizes, the ultimate elemental analysis and ash content were determined. The results were not as good as those obtained previously in a close-fitting borehole. However, the results did improve with successively larger source-to-detector distances, i.e.,as the count contribution due to hydrogen in the water decreased. It was concluded that in situ borehole analyses should be made in relatively close-fitting boreholes. ?? 1983.

  8. Active Neutron and Gamma-Ray Instrumentation for In Situ Planetary Science Applications

    NASA Technical Reports Server (NTRS)

    Parsons, A.; Bodnarik, J.; Evans, L.; Floyd, A.; Lim, L.; McClanahan, T.; Namkung, M.; Nowicki, S.; Schweitzer, J.; Starr, R.; Trombka, J.

    2011-01-01

    We describe the development of an instrument capable of detailed in situ bulk geochemical analysis of the surface of planets, moons, asteroids, and comets. This instrument technology uses a pulsed neutron generator to excite the solid materials of a planet and measures the resulting neutron and gamma-ray emission with its detector system. These time-resolved neutron and gamma-ray data provide detailed information about the bulk elemental composition, chemical context, and density distribution of the soil within 50 cm of the surface. While active neutron scattering and neutron-induced gamma-ray techniques have been used extensively for terrestrial nuclear well logging applications, our goal is to apply these techniques to surface instruments for use on any solid solar system body. As described, experiments at NASA Goddard Space Flight Center use a prototype neutron-induced gamma-ray instrument and the resulting data presented show the promise of this technique for becoming a versatile, robust, workhorse technology for planetary science, and exploration of any of the solid bodies in the solar system. The detection of neutrons at the surface also provides useful information about the material. This paper focuses on the data provided by the gamma-ray detector.

  9. The Probing In-Situ With Neutron and Gamma Rays (PING) Instrument for Planetary Composition Measurements

    NASA Technical Reports Server (NTRS)

    Parsons, A.; Bodnarik, J.; Evans, L.; McClanahan, T.; Namkung, M.; Nowicki, S.; Schweitzer, J.; Starr, R.

    2012-01-01

    The Probing In situ with Neutrons and Gamma rays (PING) instrument (formerly named PNG-GRAND) [I] experiment is an innovative application of the active neutron-gamma ray technology successfully used in oil field well logging and mineral exploration on Earth over many decades. The objective of our active neutron-gamma ray technology program at NASA Goddard Space Flight Center (NASA/GSFC) is to bring PING to the point where it can be flown on a variety of surface lander or rover missions to the Moon, Mars, Venus, asteroids, comets and the satellites of the outer planets and measure their bulk surface and subsurface elemental composition without the need to drill into the surface. Gamma-Ray Spectrometers (GRS) have been incorporated into numerous orbital planetary science missions. While orbital measurements can map a planet, they have low spatial and elemental sensitivity due to the low surface gamma ray emission rates reSUlting from using cosmic rays as an excitation source, PING overcomes this limitation in situ by incorporating a powerful neutron excitation source that permits significantly higher elemental sensitivity elemental composition measurements. PING combines a 14 MeV deuterium-tritium Pulsed Neutron Generator (PNG) with a gamma ray spectrometer and two neutron detectors to produce a landed instrument that can determine the elemental composition of a planet down to 30 - 50 cm below the planet's surface, The penetrating nature of .5 - 10 MeV gamma rays and 14 MeV neutrons allows such sub-surface composition measurements to be made without the need to drill into or otherwise disturb the planetary surface, thus greatly simplifying the lander design, We are cun'ently testing a PING prototype at a unique outdoor neutron instrumentation test facility at NASA/GSFC that provides two large (1.8 m x 1.8 m x ,9 m) granite and basalt test formations placed outdoors in an empty field, Since an independent trace elemental analysis has been performed on both these Columbia River basalt and Concord Gray granite materials, these large samples present two known standards with which to compare PING's experimentally measured elemental composition results, We will present both gamma ray and neutron experimental results from PING measurements of the granite and basalt test formations in various layering configurations and compare the results to the known composition.

  10. In-situ gamma-PHA measurements to support unconditional release of 235-F chiller units

    SciTech Connect

    Salaymeh, S.R.

    2000-02-17

    The Analytical Development Section of Savannah River Technology Center (SRTC) was requested by the Facility Decommission Division (FDD) to conduct in-situ gamma-ray pulse height analysis measurements to support the unconditional release of 235-F chiller units. The chiller units were used to cool process water in the 235-F facility. The measurements' main goal is to confirm that there is no process-related contaminants present on the chillers. For each of the two F-area clean water chillers, the authors have acquired ten gamma-ray pulse height analysis spectra. This report will discuss the purpose of the measurements, the experimental setup, data acquisition, calculations and results, and a conclusion of the study.

  11. Time-resolved Neutron-gamma-ray Data Acquisition for in Situ Subsurface Planetary Geochemistry

    NASA Technical Reports Server (NTRS)

    Bodnarik, Julie G.; Burger, Dan Michael; Burger, A.; Evans, L. G.; Parsons, A. M.; Schweitzer, J. S.; Starr R. D.; Stassun, K. G.

    2013-01-01

    The current gamma-ray/neutron instrumentation development effort at NASA Goddard Space Flight Center aims to extend the use of active pulsed neutron interrogation techniques to probe the subsurface elemental composition of planetary bodies in situ. Previous NASA planetary science missions, that used neutron and/or gamma-ray spectroscopy instruments, have relied on neutrons produced from galactic cosmic rays. One of the distinguishing features of this effort is the inclusion of a high intensity 14.1 MeV pulsed neutron generator synchronized with a custom data acquisition system to time each event relative to the pulse. With usually only one opportunity to collect data, it is difficult to set a priori time-gating windows to obtain the best possible results. Acquiring time-tagged, event-by-event data from nuclear induced reactions provides raw data sets containing channel/energy, and event time for each gamma ray or neutron detected. The resulting data set can be plotted as a function of time or energy using optimized analysis windows after the data are acquired. Time windows can now be chosen to produce energy spectra that yield the most statistically significant and accurate elemental composition results that can be derived from the complete data set. The advantages of post-processing gamma-ray time-tagged event-by-event data in experimental tests using our prototype instrument will be demonstrated.

  12. Membrane-Extraction Ion Mobility Spectrometry for In-Situ Detection of Chlorinated Hydrocarbons in Water

    SciTech Connect

    Du, Yongzhai; Zhang, Wei; Whitten, William B; Li, Haiyang; Watson, David B; Xu, Jun

    2010-01-01

    Membrane-extraction ion mobility spectrometry (ME-IMS) has been developed for in-situ sampling and analysis of trace chlorinated hydrocarbons in water in a single procedure. The sampling is configured so that aqueous contaminants permeate through a spiral hollow polydimethylsiloxane (PDMS) membrane and are carried away by a vapor flow through the membrane tube. The extracted analyte flows into an atmospheric pressure chemical ionization (APCI) chamber and is analyzed in a home-made IMS analyzer. PDMS membrane is found to effectively extract chlorinated hydrocarbon solvents from liquid phase to vapor. The specialized IMS analyzer has been found to have resolutions of R=33 and 41, respectively, for negative- and positive-modes and is capable of detecting aqueous tetrachloroethylene (PCE) and trichloroethylene (TCE) as low as 80 g/L and 74 g/L in negative ion mode, respectively. The time-dependent characteristics of sampling and detection of TCE are both experimentally and theoretically studied for various concentrations, membrane lengths, and flow rates. These characteristics demonstrate that membrane-extraction IMS is feasible for the continuous monitoring of chlorinated hydrocarbons in water.

  13. In situ Analysis of Organic Compounds on Mars using Chemical Derivatization and Gas Chromatography Mass Spectrometry

    NASA Technical Reports Server (NTRS)

    Glavin, D. P.; Buch, A.; Cabane, M.; Coll, P.; Navarro-Gonzalez, R.; Mahaffy, P. R.

    2005-01-01

    One of the core science objectives of NASA's 2009 Mars Science Laboratory (MSL) mission is to determine the past or present habitability of Mars. The search for key organic compounds relevant to terrestrial life will be an important part of that assessment. We have developed a protocol for the analysis of amino acids and carboxylic acids in Mars analogue materials using gas chromatography mass spectrometry (GCMS). As shown, a variety of carboxylic acids were readily identified in soil collected from the Atacama Desert in Chile at part-per-billion levels by GCMS after extraction and chemical derivatization using the reagent N,N-tert.-butyl (dimethylsilyl) trifluoroacetamide (MTBSTFA). Several derivatized amino acids including glycine and alanine were also detected by GCMS in the Atacama soil at lower concentrations (chromatogram not shown). Lacking derivatization capability, the Viking pyrolysis GCMS instruments could not have detected amino acids and carboxylic acids, since these non-volatile compounds require chemical transformation into volatile species that are stable in a GC column. We are currently optimizing the chemical extraction and derivatization technique for in situ GCMS analysis on Mars. Laboratory results of analyses of Atacama Desert samples and other Mars analogue materials using this protocol will be presented.

  14. Photon energy conversion efficiency in gamma-ray spectrometry.

    PubMed

    vec, Anton

    2016-01-01

    Photon energy conversion efficiency coefficient is presented as the ratio of total energy registered in the collected spectrum to the emitted photon energy. This parameter is calculated from the conventional gamma-ray histogram and in principle is not affected by coincidence phenomena. This feature makes it particularly useful for calibration and measurement of radionuclide samples at close geometries. It complements the number of efficiency parameters used in gamma-ray spectrometry and can partly change the view as to how the gamma-ray spectra are displayed and processed. PMID:26474210

  15. Monitoring genetic and metabolic potential for in situ bioremediation: Mass spectrometry. 1998 annual progress report

    SciTech Connect

    Buchanan, M.V.; Hurst, G.B.; Doktycz, M.J.; Britt, P.F.; Weaver, K.; Lidstrom, M.; Costello, A.

    1998-01-01

    'A number of DOE sites are contaminated with dense non-aqueous phase liquids (DNAPLs) such as carbon tetrachloride and trichloroethylene. At many of these sites, microbial bioremediation is an attractive strategy for cleanup, since it has the potential to degrade DNAPLs in-situ. A rapid screening method to determine the broad range potential of a site''s microbial population for contaminant degradation would greatly facilitate assessment for in-situ bioremediation, as well as for monitoring ongoing bioremediation treatment. Current laboratory-based treatability methods are cumbersome and expensive. In this project, the authors are developing methods based on matrix-assisted laser desorption/ ionization mass-spectrometry (MALDI-MS) to rapidly and accurately detect polymerase chain reaction (PCR) products. In parallel, PCR primers to amplify DNA sequences from microbial genes involved in biodegradation of pollutants are being identified that are short enough to allow MALDI-MS detection. This work will lay the foundation for development of a field-portable MS-based technique for rapid assessment and monitoring of bioremediation processes on site. This report summarizes work after 1-1/2 years of a 3-year project. In this time, the authors have demonstrated MALDI-MS-based detection of signature bacterial PCR products (Hurst et al., 1998). A model system for interfacing MALDI-MS with PCR amplification is based on the pmoA gene for the active site subunit of particulate methane monooxygenase, a bacterial enzyme that can oxidize trichloroethylene. PCR primer pairs were designed to amplify relatively short segments (99 bases and 56 bases) of this gene in Type 1 and Type 2 methanotrophs. A rapid reverse-phase purification of the resulting PCR products allows MALDI-MS detection from a fraction of one 25-microliter PCR reaction. At this level of sensitivity, MALDI-MS has considerable potential to compete with existing electrophoresis and hybridization methods for detecting PCR products in this size range. To allow increased throughput, the PerSeptive Biosystems MALDI-TOF mass spectrometer allows automated MALDI data acquisition, and they have adapted their purification scheme to a 96-well microtiter plate format that allows parallel treatment of 96 PCR reactions in about ten minutes (Weaver et al., 1998). An in-house-constructed TOF mass spectrometer is being modified to allow more fundamental studies aimed at improving the MS detection of PCR products.'

  16. Comet nucleus gamma-ray spectrometer penetrator - An in situ nucleus composition experiment

    NASA Technical Reports Server (NTRS)

    Swenson, B. L.; Mascy, A. C.; Edsinger, L. E.; Squyres, S. W.; Mckay, C. P.

    1985-01-01

    An engineering design study of a comet nucleus penetrator system for in situ determinations of comet composition is presented. The system is designed for participation in the Comet Rendezvous/Asteroid Flyby mission to comet Kopff in 1996. The instrumentation payload of the penetrator system will include a passive gamma-ray spectrometer; a high frequency response accelerometer for measurements of the impact deceleration profile of the system as it penetrates to the nucleus of the comet; and several thermocouples mounted along the length of the penetrator to measure temperature and temperature gradients. The mechanical, electrical and thermal interfaces between the penetrator and the Mariner Mark II spacecraft are described. A series of line drawings is provided which illustrates the proposed configuration of the system.

  17. New shield for gamma-ray spectrometry

    NASA Technical Reports Server (NTRS)

    Brar, S. S.; Gustafson, P. F.; Nelson, D. M.

    1969-01-01

    Gamma-ray shield that can be evacuated, refilled with a clean gas, and pressurized for exclusion of airborne radioactive contaminants effectively lowers background noise. Under working conditions, repeated evacuation and filling procedures have not adversely affected the sensitivity and resolution of the crystal detector.

  18. Determination of tellurium by hydride generation with in situ trapping flame atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Matusiewicz, Henryk; Krawczyk, Magdalena

    2007-03-01

    The analytical performance of coupled hydride generation — integrated atom trap (HG-IAT) atomizer flame atomic absorption spectrometry (FAAS) system was evaluated for determination of Te in reference material (GBW 07302 Stream Sediment), coal fly ash and garlic. Tellurium, using formation of H 2Te vapors, is atomized in air-acetylene flame-heated IAT. A new design HG-IAT-FAAS hyphenated technique that would exceed the operational capabilities of existing arrangements (a water-cooled single silica tube, double-slotted quartz tube or an "integrated trap") was investigated. An improvement in detection limit was achieved compared with using either of the above atom trapping techniques separately. The concentration detection limit, defined as 3 times the blank standard deviation (3 σ), was 0.9 ng mL - 1 for Te. For a 2 min in situ pre-concentration time (sample volume of 2 mL), sensitivity enhancement compared to flame AAS, was 222 fold, using the hydride generation — atom trapping technique. The sensitivity can be further improved by increasing the collection time. The precision, expressed as RSD, was 7.0% ( n = 6) for Te. The designs studied include slotted tube, single silica tube and integrated atom trap-cooled atom traps. The accuracy of the method was verified using a certified reference material (GBW 07302 Stream Sediment) by aqueous standard calibration curves. The measured Te contents of the reference material was in agreement with the information value. The method was successfully applied to the determination of tellurium in coal fly ash and garlic.

  19. In situ digestion for the determination of Ca in beverages by tungsten coil atomic emission spectrometry.

    PubMed

    Santos, Luana N; Gonzalez, Mrio H; Moura, Monise F; Donati, George L; Nbrega, Joaquim A

    2012-08-15

    Tungsten coil atomic emission spectrometry (WCAES) is employed for the determination of calcium in juice, mineral and coconut water samples. A sample aliquot of 20 ?L is placed directly on the coil and a constant-voltage power source is used to dry and atomize the sample, as well as to promote Ca atomic emission. Analytical signals are resolved and detected using a Czerny-Turner spectrometer and a charge coupled device detector. Some experimental parameters such as coil position related to the spectrometer entrance slit and integration time are critically evaluated. A heating program with relatively constant drying temperatures is used in all measurements. An in situ digestion procedure is used to partially decompose organic matrices and improve WCAES precision and accuracy. By adding an oxidizing mixture to the sample and including a digestion step in the heating cycle, no statistical difference was observed between WCAES and ICP OES results for Ca in juice and coconut water samples. Mineral water samples were simply diluted with 1% vv(-1) HNO(3) before analysis and no significant interference was observed for concomitants such as Na and K. Despite severe positive interference caused by Mg, good agreement was obtained between WCAES and ICP OES results for Ca in several mineral water samples. Limits of detection and quantification obtained were 0.02 and 0.07 mg L(-1), respectively. The method precision, calculated as the relative standard deviation for 10 consecutive measurements of a 2.5 mg L(-1) Ca solution, is 3.8%. PMID:22841081

  20. Detection of soil microorganism in situ by combined gas chromatography mass spectrometry

    NASA Technical Reports Server (NTRS)

    Alexander, M.; Duxbury, J. M.; Francis, A. J.; Adamson, J.

    1972-01-01

    Experimental tests were made to determine whether analysis of volatile metabolic products, formed in situ, is a viable procedure for an extraterrestrial life detection system. Laboratory experiments, carried out under anaerobic conditions with addition of carbon source, extended to include a variety of soils and additional substrates. In situ experiments were conducted without amendment using a vacuum sampling system.

  1. In situ calibration of a high-resolution gamma-ray borehole sonde for assaying uranium-bearing sandstone deposits

    USGS Publications Warehouse

    Day, J.H., Jr.

    1985-01-01

    A method is presented for assaying radioactive sandstone deposits in situ by using a high-resolution borehole gamma-ray spectrometer. Gamma-ray photopeaks from the same spectrum acquired to analyze a sample are used to characterize gamma-ray attenuation properties, from which a calibration function is determined. Assay results are independent of differences between properties of field samples and those of laboratory or test-hole standards generally used to calibrate a borehole sonde. This assaying technique is also independent of the state of radioactive disequilibrium that usually exists in nature among members of the natural-decay chains. ?? 1985.

  2. Rapid in situ identification of bioactive compounds in plants by in vivo nanospray high-resolution mass spectrometry.

    PubMed

    Chang, Qing; Peng, Yue'e; Dan, Conghui; Shuai, Qin; Hu, Shenghong

    2015-03-25

    A method for the rapid in situ identification of bioactive compounds in fresh plants has been developed using in vivo nanospray coupled to high-resolution mass spectrometry (HR-MS). Using a homemade in vivo nanospray ion source, the plant liquid was drawn out from a target region and ionized in situ. The ionized bioactive compounds were then identified using Q-Orbitrap HR-MS. The accurate mass measurements of these bioactive compounds were performed by full-scan or selected ion monitoring (SIM), and tandem mass spectrometry (MS/MS) was used in the structural elucidation. Without sample pretreatment, 12 bioactive compounds in 7 different plant species were identified, namely, isoalliin in onion; butylphthalide in celery; N-methylpelletierine, pelletierine, and pseudopelletierine in pomegranate; chlorogenic acid in crabapple; solamargine, solasonine, and solasodine in nightshade; aloin and aloe-emodin in aloe; and menthone in mint. This work demonstrates that in vivo nanospray HR-MS is a good method for rapid in situ identification of bioactive compounds in plants. PMID:25749134

  3. Seabed gamma-ray spectrometry: applications at IAEA-MEL.

    PubMed

    Osvath, I; Povinec, P P

    2001-01-01

    The technique of underwater gamma-ray spectrometry has been developed to complement or replace the traditional sampling-sample analysis approach for applications with space-time constraints, e.g. large areas of investigation, emergency response or long-term monitoring. IAEA-MEL has used both high-efficiency NaI(Tl) and high-resolution HPGe spectrometry to investigate contamination with anthropogenic radionuclides in a variety of marine environments. Surveys at the South Pacific nuclear test sites of Mururoa and Fangataufa have been used to guide sampling in areas of high contamination around ground zero points. In the Irish Sea offshore from the Sellafield nuclear reprocessing plant, a gamma-ray survey of seabed sediment was carried out to obtain estimates of the distribution and subsequently, for the inventory of 137Cs in the investigated area. PMID:11379061

  4. A numerical method for the calibration of in situ gamma ray spectroscopy systems.

    PubMed

    Dewey, S C; Whetstone, Z D; Kearfott, K J

    2010-05-01

    High purity germanium in situ gamma ray spectroscopy systems are typically calibrated using pre-calculated tables and empirical formulas to estimate the response of a detector to an exponentially distributed source in a soil matrix. Although this method is effective, it has estimated uncertainties of 10-15%, is limited to only a restricted set of measurement scenarios, and the approach only applies to an exponentially distributed source. In addition, the only soil parameters that can be varied are density and moisture content, while soil attenuation properties are fixed. This paper presents a more flexible method for performing such calibrations. For this new method, a three- or four-dimensional analytical expression is derived that is a combination of a theoretical equation and experimentally measured data. Numerical methods are used to integrate this expression, which approximates the response of a detector to a large variety of source distributions within any soil, concrete, or other matrix. The calculation method is flexible enough to allow for the variation of multiple parameters, including media attenuation properties and the measurement geometry. The method could easily be adapted to horizontally non-uniform sources as well. Detector responses are calculated analytically and Monte Carlo radiation transport simulations are used to verify the results. Results indicate that the method adds an uncertainty of only approximately 5% to the other uncertainties typically associated with the calibration of a detector system. PMID:20386196

  5. Determination of environmental radiation flux and organ doses using in-situ gamma spectroscopy

    NASA Astrophysics Data System (ADS)

    Al-Ghamdi, Abdulrahman S.

    Contamination of buildings represent a unique problem during Decontamination and Decommissioning (D&D) of nuclear facilities. It is necessary to determine the long-lived radionuclides and their respective specific activities in building materials before the right D&D decision can be made. At the same time, radiation risk of workers or potential occupants in the facility must be assessed as part of the D&D process. The goal of this project was to develop a methodology of obtaining gamma radiation flux and organ doses from in-situ gamma spectroscopy. Algorithms were developed to simulate the response functions of the HPGe detector and to convert the spectra into photon fluences. A Monte Carlo code, MCNP4C, was used to simulate HPGe detector response and to develop the conversion algorithm. The simulated spectra obtained for an HPGe detector were converted to flux using the algorithm for various different geometries. The response functions of the detector are presented in this document for the gamma energies from 60 keV to 2.2 MeV. Published fluence-to-dose conversion coefficients were used to calculate organ doses and effective dose equivalent. We then tested the theory at a 100-MeV linear electron accelerator at Rensselaer Polytechnic Institute (RPI). Samples of the activated concrete walls and floor in the target room of the Linac facility as well as some steel samples were taken to quantify the specific activities of the structures. The results show that the most important long-lived radionuclides include 22 Na, 46Sc, 54 Mn, 57Co, 60 Co, 65Zn, 152 Eu and 154Eu, depending on the location and composition of the material. The specific activities at the Linac facility range from 1.15E-01 to 765.31 muCi/Kg. The annual effective dose equivalent was assessed to be 2.44 mSv y-1 (0.244 rem y-1 ), which is about 5% of the Annual EDE limits to workers.

  6. In-situ Ir concentration measurements in KT-boundary sediments by accelerator secondary ion mass spectrometry

    NASA Astrophysics Data System (ADS)

    Maden, C.; Dbeli, M.; Hofmann, B.; Suter, M.

    2004-06-01

    Accelerator SIMS is the extension of secondary ion mass spectrometry (SIMS) with accelerator mass spectrometry (AMS) by which molecular interferences in the SIMS spectrum are removed. The potential of the PSI/ETH accelerator SIMS facility with respect to concentration analysis is demonstrated by presenting in-situ iridium concentration measurements in sedimentary layers around the Cretaceous-Tertiary transition (KT-boundary) from the Starkville South section, Raton basin, Colorado. In these sediments an iridium concentration anomaly is believed to originate from the impact of a meteorite 65 million years ago. By accelerator SIMS iridium concentrations in the range of 0.1 ng/g could be measured with a lateral resolution of 100 ?m reproducing neutron activation analysis data. The characteristics of accelerator SIMS together with boundary conditions influencing measurements are discussed.

  7. Ion funnel augmented Mars atmospheric pressure photoionization mass spectrometry for in situ detection of organic molecules.

    PubMed

    Johnson, Paul V; Hodyss, Robert; Beauchamp, J L

    2014-11-01

    Laser desorption is an attractive technique for in situ sampling of organics on Mars given its relative simplicity. We demonstrate that under simulated Martian conditions (~2.5 Torr CO(2)) laser desorption of neutral species (e.g., polycyclic aromatic hydrocarbons), followed by ionization with a simple ultraviolet light source such as a discharge lamp, offers an effective means of sampling organics for detection and identification with a mass spectrometer. An electrodynamic ion funnel is employed to provide efficient ion collection in the ambient Martian environment. This experimental methodology enables in situ sampling of Martian organics with minimal complexity and maximum flexibility. PMID:24986759

  8. REAL-TIME IN-SITU MEASUREMENT OF MATERIAL ELASTIC PROPERTIES IN A HIGH GAMMA IRRADIATION ENVIRONMENT

    SciTech Connect

    Ken Telschow; Rob Schley; Dave Cottle

    2006-05-01

    The first measurements of elastic vibrations of an object in-situ to a high gamma irradiation field using a laser coupled resonant ultrasound method are described. A vibration mode of an Inconel hollow capped cylinder was measured throughout a period of 170 hours as the gamma radiation field was increased to 104 Gray/hour. The vibration mode frequency was observed to change in a manner consistent with the temperature dependence of the elastic stiffness coefficients of the material. These results illustrate the efficacy of the laser approach for real-time resonant ultrasound measurements in this severely hostile nuclear environment.

  9. Investigating the Origin and Evolution of Venus with In Situ Mass Spectrometry

    NASA Technical Reports Server (NTRS)

    Trainer, M. G.; Mahaffy, P. R.; Brinckerhoff, W. B.; Johnson, N. M.; Glaze, L. S.

    2015-01-01

    Measurement of noble gas abundances on Venus remain a high priority for planetary science. These studies are only possible through in situ measurement, and can be accomplished by a modern neutral mass spectrometer (NMS) such as that developed at NASA Goddard, based on flight-proven technology. Here we show how the measurement of noble gases can be secured using demonstrated enrichment techniques.

  10. In Situ Mapping of Nutrient Uptake in the Rhizosphere Using Nanoscale Secondary Ion Mass Spectrometry1[OA

    PubMed Central

    Clode, Peta L.; Kilburn, Matt R.; Jones, David L.; Stockdale, Elizabeth A.; Cliff, John B.; Herrmann, Anke M.; Murphy, Daniel V.

    2009-01-01

    Plant roots and microorganisms interact and compete for nutrients within the rhizosphere, which is considered one of the most biologically complex systems on Earth. Unraveling the nitrogen (N) cycle is key to understanding and managing nutrient flows in terrestrial ecosystems, yet to date it has proved impossible to analyze and image N transfer in situ within such a complex system at a scale relevant to soil-microbe-plant interactions. Linking the physical heterogeneity of soil to biological processes marks a current frontier in plant and soil sciences. Here we present a new and widely applicable approach that allows imaging of the spatial and temporal dynamics of the stable isotope 15N assimilated within the rhizosphere. This approach allows visualization and measurement of nutrient resource capture between competing plant cells and microorganisms. For confirmation we show the correlative use of nanoscale secondary ion mass spectrometry, and transmission electron microscopy, to image differential partitioning of 15NH4+ between plant roots and native soil microbial communities at the submicron scale. It is shown that 15N compounds can be detected and imaged in situ in individual microorganisms in the soil matrix and intracellularly within the root. Nanoscale secondary ion mass spectrometry has potential to allow the study of assimilatory processes at the submicron level in a wide range of applications involving plants, microorganisms, and animals. PMID:19812187

  11. Analysis of size-fractionated soil samples by gamma spectrometry.

    PubMed

    Savva, M I; Karangelos, D J; Anagnostakis, M J; Simopoulos, S E

    2016-03-01

    The purpose of this work was to investigate the effect of particle size on radionuclides in soil, particularly in relation to depth. A set of soil samples at the 0-10cm and 10-20cm depth layers were collected, separated into size fractions using a sieving machine and analyzed by gamma spectrometry to determine (238)U, (226)Ra, (210)Pb, and (137)Cs. Significant variations between different size fractions and depth layers were observed. A 0-20cm depth profile was also investigated. PMID:26671791

  12. Gamma ray spectrometry of LDEF samples at SRL

    NASA Technical Reports Server (NTRS)

    Winn, Willard G.

    1992-01-01

    A total of 31 samples from the Long Duration Exposure Facility (LDEF), including materials of aluminum, vanadium, and steel trunnions were analyzed by ultra-low-level gamma spectrometry. The study quantified particle induced activations of Na-22, Sc-46, Cr-51, Mn-54, Co-56, Co-57, Co-58, and Co-60. The samples of trunnion sections exhibited increasing activity toward the outer end of the trunnion and decreasing activity toward its radial center. The trunnion sections did not include end pieces, which were reported to collect noticeable Be-7 on their leading surfaces. No significant Be-7 was detected in the samples analyzed.

  13. Gamma ray spectrometry of LDEF samples at SRS

    NASA Technical Reports Server (NTRS)

    Winn, Willard G.

    1991-01-01

    A total of 31 samples from Long Duration Exposure Facility (LDEF), including materials of Al, V, and steel trunnions were analyzed by ultralow level gamma spectrometry. The study quantified particle induced activations of Na-22, Sc-46, Cr-51, Mn-54, Co-56, Co-57, Co-58, and Co-60. The samples of trunnion sections exhibited increasing activity toward the outer end of the trunnion and decreasing activity toward its radial center. The trunnion sections did not include an end piece that collects noticeable Be-7 on its leading surface. No significant Be-7 was detected in the samples analyzed. The most sensitive analyses were performed with a 90 pct. efficient HPGe gamma ray detector, which is enclosed in a purged active/passive active shield.

  14. Investigating the Origin and Evolution of Venus with In Situ Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Trainer, M. G.; Mahaffy, P. R.; Brinckerhoff, W. B.; Johnson, N. M.; Glaze, L. S.

    2015-10-01

    Measurement of noble gas abundances on Venus remain a high priority for planetary science [1,2]. These studies are only possible through in situ measurement, and can be accomplished by a modern neutral mass spectrometer (NMS) such as that developed at NASA Goddard, based on flight-proven technology. Here we show how the measurement of noble gases can be secured using demonstrated enrichment techniques.

  15. Slow elimination of phosphorylated histone {gamma}-H2AX from DNA of terminally differentiated mouse heart cells in situ

    SciTech Connect

    Gavrilov, Boris; Vezhenkova, Irina; Firsanov, Denis; Solovjeva, Liudmila; Svetlova, Maria; Mikhailov, Vyacheslav; Tomilin, Nikolai . E-mail: nvtom@hotmail.com

    2006-09-08

    Phosphorylation of replacement histone H2AX occurs in megabase chromatin domains around double-strand DNA breaks (DSBs) and this modification (called {gamma}-H2AX) may serve as a useful marker of genome damage and repair in terminally differentiated cells. Here using immunohistochemistry we studied kinetics of {gamma}-H2AX formation and elimination in the X-irradiated mouse heart and renal epithelial tissues in situ. Unirradiated tissues have 3-5% {gamma}-H2AX-positive cells and in tissues fixed 1 h after X-irradiation {gamma}-H2AX-positive nuclei are induced in a dose-dependent manner approaching 20-30% after 3 Gy of IR. Analysis of mouse tissues at different times after 3 Gy of IR showed that maximal induction of {gamma}-H2AX in heart is observed 20 min after IR and then is decreased slowly with about half remaining 23 h later. In renal epithelium maximum of the {gamma}-H2AX-positive cells is observed 40 min after IR and then decreases to control values in 23 h. This indicates that there are significant variations between non-proliferating mammalian tissues in the initial H2AX phosphorylation rate as well as in the rate of {gamma}-H2AX elimination after X-irradiation, which should be taken into account in the analysis of radiation responses.

  16. Gamma spectrometry of 234Th (238U) in environmental samples.

    PubMed

    El-Daoushy, Farid; Hernndez, Francisco

    2002-07-01

    Environmental samples from a wide-range of aquatic and soil deposits, mainly of Scandinavian origin, were analysed for 234Th (238U) using low-level gamma-spectrometry. The diversity of the samples, in terms of composition and ages, allowed a detailed evaluation of the analytical problems associated with gamma-ray spectrometry with focus on the reliability of the 234Th peaks for absolute determination of the 234Th activities. The X-ray contributions in the 93 keV peak were compared with the corresponding self-absorption corrected activities of the 63 keV peak. These X-ray contributions were, also, correlated with the 238U, 232Th, 235U, 40K and 137Cs activities of the samples. Despite the difficulties imposed by the self-absorption corrections, the 63 keV peak is still the best option. Large variability in the 93 keV peak interferences, due to X-rays from Th, exists in sediment and soil samples. Only in the case of young ombrotrophic peat samples was it possible to conclude that the 93 keV peak is free from X-ray contributions and can be as good as the 63 keV Monte-Carlo self-absorption corrected peak. X-ray contributions in the samples correlated with the 238U and 232Th activities, only, in closed environmental systems where a secular equilibrium with the daughters of the U/Th series can occur. PMID:12173662

  17. Physiologically active hydrogel (in situ gel) of sparfloxacin and its evaluation for ocular retention using gamma scintigraphy

    PubMed Central

    Gupta, Himanshu; Malik, Aqil; Khar, R. K.; Ali, Asgar; Bhatnagar, Aseem; Mittal, Gaurav

    2015-01-01

    Objective: Due to the structure and physiological barrier of eye, only 1% of instilled dose is available for action on the corneal surface. In this work, we developed and evaluated chitosan (pH sensitive) and gellan gum (ion sensitive) in situ gel of sparfloxacin to improve precorneal residence time. Materials and Methods: A protocol for radiolabeling of sparfloxacin with Tc-99m was optimized to study the ocular retention using gamma scintigraphy technique. Results: The clear formulation was developed. In vitro release showed a sustained and prolonged release compared to plain eye drop solution. Dynamic and static gamma scintigraphy showed better retention than plain eye drops. The ocular tolerance test (hen's egg test-chorioallantoic membrane test and infra-red study) showed that the formulation is nonirritant and can be used as ocular vehicle. Conclusion: Radiolabel protocol for sparfloxacin was successfully developed and evaluated on ocular retention studies of developed in situ gel. The developed in situ gel is non irritant and can go further with clinical evaluation. PMID:26229353

  18. In situ cell-by-cell imaging and analysis of small cell populations by mass spectrometry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Molecular imaging by mass spectrometry (MS) is emerging as a tool to determine the distribution of proteins, lipids and metabolites in tissues. The existing imaging methods, however, rely on predefined typically rectangular grids for sampling that ignore the natural cellular organization of the tiss...

  19. The laser ablation ion funnel: Sampling for in situ mass spectrometry on Mars

    NASA Astrophysics Data System (ADS)

    Johnson, Paul V.; Hodyss, Robert; Tang, Keqi; Brinckerhoff, William B.; Smith, Richard D.

    2011-04-01

    A considerable investment has been made by NASA and other space agencies to develop instrumentation suitable for in situ analytical investigation of extra terrestrial bodies including various mass spectrometers (time-of-flight, quadrupole ion trap, quadrupole mass filters, etc.). However, the front-end sample handling that is needed to collect and prepare samples for interrogation by such instrumentation remains underdeveloped. Here we describe a novel approach tailored to the exploration of Mars where ions are created in the ambient atmosphere via laser ablation and then efficiently transported into a mass spectrometer for in situ analysis using an electrodynamic ion funnel. This concept would enable elemental and isotopic analysis of geological samples with the analysis of desorbed organic material a possibility as well. Such an instrument would be suitable for inclusion on all potential missions currently being considered such as the Mid-Range Rover, the Astrobiology Field Laboratory, and Mars Sample Return (i.e., as a sample pre-selection triage instrument), among others.

  20. The Laser Ablation Ion Funnel: Sampling for in situ Mass Spectrometry on Mars

    NASA Technical Reports Server (NTRS)

    Johnson, Paul V.; Hodyss, Robert; Tang, Keqi; Brinckerhoff, William B.; Smith, Richard D.

    2011-01-01

    A considerable investment has been made by NASA and other space agencies to develop instrumentation suitable for in situ analytical investigation of extra terrestrial bodies including various mass spectrometers (time-of-flight, quadrupole ion trap, quadrupole mass filters, etc.). However, the front-end sample handling that is needed to collect and prepare samples for interrogation by such instrumentation remains underdeveloped. Here we describe a novel approach tailored to the exploration of Mars where ions are created in the ambient atmosphere via laser ablation and then efficiently transported into a mass spectrometer for in situ analysis using an electrodynamic ion funnel. This concept would enable elemental and isotopic analysis of geological samples with the analysis of desorbed organic material a possibility as well. Such an instrument would be suitable for inclusion on all potential missions currently being considered such as the Mid-Range Rover, the Astrobiology Field Laboratory, and Mars Sample Return (i.e., as a sample pre-selection triage instrument), among others.

  1. In situ analysis of soybeans and nuts by probe electrospray ionization mass spectrometry.

    PubMed

    Petroselli, Gabriela; Mandal, Mridul K; Chen, Lee C; Hiraoka, Kenzo; Nonami, Hiroshi; Erra-Balsells, Rosa

    2015-04-01

    The probe electrospray ionization (PESI) is an ESI-based ionization technique that generates electrospray from the tip of a solid metal needle. In the present work, we describe the PESI mass spectra obtained by in situ measurement of soybeans and several nuts (peanuts, walnuts, cashew nuts, macadamia nuts and almonds) using different solid needles as sampling probes. It was found that PESI-MS is a valuable approach for in situ lipid analysis of these seeds. The phospholipid and triacylglycerol PESI spectra of different nuts and soybean were compared by principal component analysis (PCA). PCA shows significant differences among the data of each family of seeds. Methanolic extracts of nuts and soybean were exposed to air and sunlight for several days. PESI mass spectra were recorded before and after the treatment. Along the aging of the oil (rancidification), the formation of oxidated species with variable number of hydroperoxide groups could be observed in the PESI spectra. The relative intensity of oxidated triacylglycerols signals increased with days of exposition. Monitoring sensitivity of PESI-MS was high. This method provides a fast, simple and sensitive technique for the analysis (detection and characterization) of lipids in seed tissue and degree of oxidation of the oil samples. PMID:26149112

  2. In situ detection of histone variants and modifications in mouse brain using imaging mass spectrometry.

    PubMed

    Lahiri, Shibojyoti; Sun, Na; Solis-Mezarino, Victor; Fedisch, Andreas; Ninkovic, Jovica; Feuchtinger, Annette; Götz, Magdalena; Walch, Axel; Imhof, Axel

    2016-02-01

    Histone posttranslational modifications and histone variants control the epigenetic regulation of gene expression and affect a wide variety of biological processes. A complex pattern of such modifications and variants defines the identity of cells within complex organ systems and can therefore be used to characterize cells at a molecular level. However, their detection and identification in situ has been limited so far due to lack of specificity, selectivity, and availability of antihistone antibodies. Here, we describe a novel MALDI imaging MS based workflow, which enables us to detect and characterize histones by their intact mass and their correlation with cytological properties of the tissue using novel statistical and image analysis tools. The workflow allows us to characterize the in situ distribution of the major histone variants and their modification in the mouse brain. This new analysis tool is particularly useful for the investigation of expression patterns of the linker histone H1 variants for which suitable antibodies are so far not available. PMID:26593131

  3. In situ biomarker discovery and label-free molecular histopathological diagnosis of lung cancer by ambient mass spectrometry imaging

    PubMed Central

    Li, Tiegang; He, Jiuming; Mao, Xinxin; Bi, Ying; Luo, Zhigang; Guo, Chengan; Tang, Fei; Xu, Xin; Wang, Xiaohao; Wang, Mingrong; Chen, Jie; Abliz, Zeper

    2015-01-01

    Sensitive and spatial exploration of the metabolism of tumors at the metabolome level is highly challenging. In this study, we developed an in situ metabolomics method based on ambient mass spectrometry imaging using air flow-assisted desorption electrospray ionization (AFADESI), which can spatially explore the alteration of global metabolites in tissues with high sensitivity. Using this method, we discovered potential histopathological diagnosis biomarkers (including lipids, amino acids, choline, peptides, and carnitine) from 52 postoperative lung cancer tissue samples and then subsequently used these biomarkers to generate images for rapid and label-free histopathological diagnosis. These biomarkers were validated with a sensitivity and a specificity of 93.5% and 100%, respectively. Moreover, a single imaging analysis of a cryosection that visualized all these biomarkers, taking tens of minutes, revealed the type and subtype of the cancer. This method could potentially be used as a molecular pathological tool for rapid clinical lung cancer diagnosis and immediate image-guided surgery. PMID:26404114

  4. Matrix assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) for direct visualization of plant metabolites in situ.

    PubMed

    Sturtevant, Drew; Lee, Young-Jin; Chapman, Kent D

    2016-02-01

    Direct visualization of plant tissues by matrix assisted laser desorption ionization-mass spectrometry imaging (MALDI-MSI) has revealed key insights into the localization of metabolites in situ. Recent efforts have determined the spatial distribution of primary and secondary metabolites in plant tissues and cells. Strategies have been applied in many areas of metabolism including isotope flux analyses, plant interactions, and transcriptional regulation of metabolite accumulation. Technological advances have pushed achievable spatial resolution to subcellular levels and increased instrument sensitivity by several orders of magnitude. It is anticipated that MALDI-MSI and other MSI approaches will bring a new level of understanding to metabolomics as scientists will be encouraged to consider spatial heterogeneity of metabolites in descriptions of metabolic pathway regulation. PMID:26613199

  5. In situ GaN decomposition analysis by quadrupole mass spectrometry and reflection high-energy electron diffraction

    SciTech Connect

    Fernandez-Garrido, S.; Calleja, E.; Koblmueller, G.; Speck, J. S.

    2008-08-01

    Thermal decomposition of wurtzite (0001)-oriented GaN was analyzed: in vacuum, under active N exposure, and during growth by rf plasma-assisted molecular beam epitaxy. The GaN decomposition rate was determined by measurements of the Ga desorption using in situ quadrupole mass spectrometry, which showed Arrhenius behavior with an apparent activation energy of 3.1 eV. Clear signatures of intensity oscillations during reflection high-energy electron diffraction measurements facilitated complementary evaluation of the decomposition rate and highlighted a layer-by-layer decomposition mode in vacuum. Exposure to active nitrogen, either under vacuum or during growth under N-rich growth conditions, strongly reduced the GaN losses due to GaN decomposition.

  6. In-situ suspended aggregate microextraction of gold nanoparticles from water samples and determination by electrothermal atomic absorption spectrometry.

    PubMed

    Choleva, Tatiana G; Kappi, Foteini A; Tsogas, George Z; Vlessidis, Athanasios G; Giokas, Dimosthenis L

    2016-05-01

    This work describes a new method for the extraction and determination of gold nanoparticles in environmental samples by means of in-situ suspended aggregate microextraction and electrothermal atomic absorption spectrometry. The method relies on the in-situ formation of a supramolecular aggregate phase through ion-association between a cationic surfactant and a benzene sulfonic acid derivative. Gold nanoparticles are physically entrapped into the aggregate phase which is separated from the bulk aqueous solution by vacuum filtration on the surface of a cellulose filter in the form of a thin film. The film is removed from the filter surface and is dissociated into an acidified methanolic solution which is used for analysis. Under the optimized experimental conditions, gold nanoparticles can be efficiently extracted from water samples with recovery rates between 81.0-93.3%, precision 5.4-12.0% and detection limits as low as 75femtomolL(-1) using only 20mL of sample volume. The satisfactory analytical features of the method along with the simplicity indicate the efficiency of this new approach to adequately collect and extract gold nanoparticle species from water samples. PMID:26946014

  7. Tellurium speciation analysis using hydride generation in situ trapping electrothermal atomic absorption spectrometry and ruthenium or palladium modified graphite tubes.

    PubMed

    Yildirim, Emrah; Akay, Pınar; Arslan, Yasin; Bakirdere, Sezgin; Ataman, O Yavuz

    2012-12-15

    Speciation of tellurium can be achieved by making use of different kinetic behaviors of Te(IV) and Te(VI) upon their reaction with sodium borohydride using hydride generation. While Te(IV) can form H(2)Te, Te(VI) will not form any volatile species during the course of hydride formation and measurement by atomic absorption spectrometry. Quantitative reduction of Te(VI) was achieved through application of a microwave assisted prereduction of Te(VI) in 6.0 mol/L HCl solution. Enhanced sensitivity was achieved by in situ trapping of the generated H(2)Te species in a previously heated graphite furnace whose surface was modified using Pd or Ru. Overall efficiency for in situ trapping in pyrolytically coated graphite tube surface was found to be 15% when volatile analyte species are trapped for 60s at 300°C. LOD and LOQ values were calculated as 0.086 ng/mL and 0.29 ng/mL, respectively. Efficiency was increased to 46% and 36% when Pd and Ru surface modifiers were used, respectively. With Ru modified graphite tube 173-fold enhancement was obtained over 180 s trapping period with respect to ETAAS; the tubes could be used for 250 cycles. LOD values were 0.0064 and 0.0022 ng/mL for Pd and Ru treated ETAAS systems, respectively, for 180 s collection of 9.6 mL sample solution. PMID:23182575

  8. In Situ Analysis of Small Populations of Adherent Mammalian Cells Using Laser Ablation Electrospray Ionization Mass Spectrometry in Transmission Geometry.

    PubMed

    Jacobson, Rachelle S; Thurston, Richard L; Shrestha, Bindesh; Vertes, Akos

    2015-12-15

    Most cultured cells used for biomedical research are cultured adherently, and the requisite detachment prior to biochemical analysis might induce chemical changes. This is especially crucial if accurate metabolic measurements are desired, given the rapid turnover of metabolites in living organisms. There are only a few methods available for the nontargeted in situ analysis of small adherent cell populations. Here we show that laser ablation electrospray ionization (LAESI) mass spectrometry (MS) can be used to analyze adherent cells directly, while still attached to the culture surface. To reduce the size of the analyzed cell population, the spot size constraints of conventional focusing in reflection geometry (rg) LAESI had to be eliminated. By introducing transmission geometry (tg) LAESI and incorporating an objective with a high numerical aperture, spot sizes of 10-20 ?m were readily achieved. As few as five adherent cells could be specifically selected for analysis in their culturing environment. The importance of in situ analysis was highlighted by comparing the metabolite composition of adherent versus suspended cells. For example, we observed that cells analyzed adherently yielded higher values for the adenylate energy charge (0.90 0.09 for adherent cells vs 0.09 0.03 for suspended cells). Additionally, due to the smaller focal spot size, tg-LAESI enabled the analysis of ?20 times smaller cell populations compared to rg-LAESI. PMID:26558336

  9. Development of the Probing In-Situ with Neutron and Gamma Rays (PING) Instrument for Planetary Science Applications

    NASA Technical Reports Server (NTRS)

    Parsons, A.; Bodnarik, J.; Burger, D.; Evans, L.; Floyd, S; Lim, L.; McClanahan, T.; Namkung, M.; Nowicki, S.; Schweitzer, J.; Starr, R.; Trombka, J.

    2011-01-01

    The Probing In situ with Neutrons and Gamma rays (PING) instrument is a promising planetary science application of the active neutron-gamma ray technology that has been used successfully in oil field well logging and mineral exploration on Earth for decades. Similar techniques can be very powerful for non-invasive in situ measurements of the subsurface elemental composition on other planets. The objective of our active neutron-gamma ray technology program at NASA Goddard Space Flight Center (NASA/GSFC) is to bring instruments using this technology to the point where they can be flown on a variety of surface lander or rover missions to the Moon, Mars, Venus, asteroids, comets and the satellites of the outer planets. PING combines a 14 MeV deuterium-tritium pulsed neutron generator with a gamma ray spectrometer and two neutron detectors to produce a landed instrument that can determine the elemental composition of a planet down to 30 - 50 cm below the planet's surface. The penetrating nature of.5 - 10 MeV gamma rays and 14 MeV neutrons allows such sub-surface composition measurements to be made without the need to drill into or otherwise disturb the planetary surface, thus greatly simplifying the lander design. We are currently testing a PING prototype at a unique outdoor neutron instrumentation test facility at NASA/GSFC that provides two large (1.8 m x 1.8 m x.9 m) granite and basalt test formations placed outdoors in an empty field. Since an independent trace elemental analysis has been performed on both the Columbia River basalt and Concord Gray granite materials, these samples present two known standards with which to compare PING's experimentally measured elemental composition results. We will present experimental results from PING measurements of both the granite and basalt test formations and show how and why the optimum PING instrument operating parameters differ for studying the two materials.

  10. Novel application of ?/? autoradiography and collimated ?-spectrometry to study in situ radionuclide migration paths in fractured rock

    NASA Astrophysics Data System (ADS)

    Mri, A.; Biggin, C.; Mder, U.; Eikenberg, J.; Rthi, M.

    ?/?-Autoradiography and collimated ?-spectrometry were applied on in situ impregnated core samples containing various radionuclides such as 137Cs and 60Co to study diffusion paths in fractured granitic rocks from the Grimsel test site (GTS). The radionuclide tracers were injected into a water conducting feature (WCF) during years ( 137Cs) or months ( 60Co) before the flow field and the adjacent rock matrix were overcored for analysis. The retardation sites of the radionuclides in and around the flow paths were first determined by means of a state of the art ?/?-autoradiography scanner. Increased activity above natural background was observed both in the WCF and in the adjacent rock matrix showing structural control of radionuclide transport into the rock matrix as activity in the matrix was mainly bound to grain-boundary pores. In a second step, the areas of increased activity within the WCF and in the neighbouring rock matrix were investigated using a HPGe ?-spectrometer. A new setup for collimated ?-spectrometry was developed, which revealed spatial and nuclide specific information about tracer concentrations in the samples. Although this technique is hampered by much reduced counting efficiencies, it allows non-invasive determination of spatial distribution of radionuclides at the centimetre scale. A preliminary data set produced to show the application possibilities of these techniques indicated maximum 137Cs diffusion into the rock matrix adjacent to a WCF to a depth of 45 mm within 3 years and for 60Co to about 3 mm in 2 months.

  11. Two-Step Resonance-Enhanced Desorption Laser Mass Spectrometry for In Situ Analysis of Organic-Rich Environments

    NASA Technical Reports Server (NTRS)

    Getty, S. A.; Grubisic, A.; Uckert, K.; Li, X.; Cornish, T.; Cook, J. E.; Brinckerhoff, W. B.

    2016-01-01

    A wide diversity of planetary surfaces in the solar system represent high priority targets for in situ compositional and contextual analysis as part of future missions. The planned mission portfolio will inform our knowledge of the chemistry at play on Mars, icy moons, comets, and primitive asteroids, which can lead to advances in our understanding of the interplay between inorganic and organic building blocks that led to the evolution of habitable environments on Earth and beyond. In many of these environments, the presence of water or aqueously altered mineralogy is an important indicator of habitable environments that are present or may have been present in the past. As a result, the search for complex organic chemistry that may imply the presence of a feedstock, if not an inventory of biosignatures, is naturally aligned with targeted analyses of water-rich surface materials. Here we describe the two-step laser mass spectrometry (L2MS) analytical technique that has seen broad application in the study of organics in meteoritic samples, now demonstrated to be compatible with an in situ investigation with technique improvements to target high priority planetary environments as part of a future scientific payload. An ultraviolet (UV) pulsed laser is used in previous and current embodiments of laser desorption/ionization mass spectrometry (LDMS) to produce ionized species traceable to the mineral and organic composition of a planetary surface sample. L2MS, an advanced technique in laser mass spectrometry, is selective to the aromatic organic fraction of a complex sample, which can provide additional sensitivity and confidence in the detection of specific compound structures. Use of a compact two-step laser mass spectrometer prototype has been previously reported to provide specificity to key aromatic species, such as PAHs, nucleobases, and certain amino acids. Recent improvements in this technique have focused on the interaction between the mineral matrix and the organic analyte. The majority of planetary targets of astrobiological interest are characterized by the presence of water or hydrated mineral phases. Water signatures can indicate a history of available liquid water that may have played an important role in the chemical environment of these planetary surfaces and subsurfaces. The studies we report here investigate the influence of water content on the detectability of organics by L2MS in planetary analog samples.

  12. Elastic and plastic properties of gamma + laves phase in-situ composite alloys using nanoindentation techniques

    SciTech Connect

    Weaver, M.L.; Stevenson, M.E.; Shamsuzzoha, M.; Ott, R.D.; Brady, M.P.

    1999-07-01

    In the present study, the local elastic and plastic properties of the {gamma}-TiAl and the Laves phases have been investigated in a series of {gamma} + Laves alloys using room-temperature compression. Vickers microhardness, and nanoindentation with an emphasis on elucidating the local property changes in {gamma} + Laves alloys deformed at room temperature. This study shows that nanoindentation can be used to provide useful information on plastic flow in multiphase intermetallic alloys.

  13. Laser Ablation Electrodynamic Ion Funnel for In Situ Mass Spectrometry on Mars

    NASA Technical Reports Server (NTRS)

    Johnson, Paul V.; Hodyss, Robert P.; Tang, Keqi; Smith, Richard D.

    2012-01-01

    A front-end instrument, the laser ablation ion funnel, was developed, which would ionize rock and soil samples in the ambient Martian atmosphere, and efficiently transport the product ions into a mass spectrometer for in situ analysis. Laser ablation creates elemental ions from a solid with a high-power pulse within ambient Mars atmospheric conditions. Ions are captured and focused with an ion funnel into a mass spectrometer for analysis. The electrodynamic ion funnel consists of a series of axially concentric ring-shaped electrodes whose inside diameters (IDs) decrease over the length of the funnel. DC potentials are applied to each electrode, producing a smooth potential slope along the axial direction. Two radio-frequency (RF) AC potentials, equal in amplitude and 180 out of phase, are applied alternately to the ring electrodes. This creates an effective potential barrier along the inner surface of the electrode stack. Ions entering the funnel drift axially under the influence of the DC potential while being restricted radially by the effective potential barrier created by the applied RF. The net result is to effectively focus the ions as they traverse the length of the funnel.

  14. Analysis of Tropical Forest Fire Emissions Using in Situ Gas Chromatography/Mass Spectrometry during Sambba

    NASA Astrophysics Data System (ADS)

    Minaeian, J.; Lewis, A. C.; Edwards, P. M.; Evans, M. J.; Hopkins, J. R.; Lee, J. D.; Purvis, R.

    2014-12-01

    Vertical atmospheric profiles of volatile organic compounds (VOCs) were made over Amazonia using an in situ gas chromatography/mass spectrometer (GC/MS), including isoprene, methacrolein, methyl vinyl ketone and products of biomass burning such as benzene. Measurements were made in the Amazonian (Rondnia and Amazonas) region during September 2012, a period of extensive biomass burning. Data was obtained between 100m and 8500m from the FAAM BAe 146 research aircraft. Isoprene was observed to be constrained overwhelmingly to the boundary layer (height typically ~2500m) with mean boundary layer mixing ratio of ~2 ppbv and a peak of ~5 ppbv at the lowest flight levels of 100 m. First generation isoprene oxidation products, methyl vinyl ketone and methacrolein, were quantified individually rather than as the sum of the pair, which is more commonly found in the literature. Both MACR and MVK were constrained primarily to the boundary layer, however trace quantities could be seen in the free troposphere to a height of 8000 m. Benzene from biomass burning was observed in both boundary layer and free troposphere, with a peak mixing ratio of ~0.8 ppbv at 750 m. This work will present the spatial distribution of isoprene within the boundary as a function of underlying surface type. The vertical profiles of all species are then compared to representative simulations from the GEOS-Chem chemistry transport model and conclusions drawn on the success of the model in representing emissions and oxidation chemistry.

  15. High-resolution gamma-ray spectrometry in uranium exploration

    USGS Publications Warehouse

    Moxham, Robert M.; Tanner, Allan B.

    1977-01-01

    Sedimentary-type uranium deposits accumulate at favorable sites along a migration path which may be kilometers in length. Their source is a large volume of rock from which the uranium has been leached. The geochemical mobilities and half lives of uranium and its daughter products vary widely so that they are transported from the source rocks, at different rates, along the migration path to their ultimate site. The radioactive disequilibrium resulting from this process has been well documented in the immediate vicinity of ore deposits, and disequilibrium is commonly recorded on gamma-ray logs up the hydraulic gradient from uranium ore. Little is known about the state of secular equilibrium in the leached host rocks, which often represent the only part of the migration path that is at or near the surface and is thus most accessible to the exploration geophysicist. High-resolution gamma-ray spectrometry provides a means of investigating the disequilibrium associated with uranium leaching and migration. Direct measurement of uranium can be made by this method, and the equivalent weight percents can be determined for six of the seven daughter-product decay groups that characterize the state of radioactive equilibrium. The technique has been used quantitatively in laboratory studies, where the results compare favorably with radiochemical analyses; field experiments suggest that semi-quantitative data may be obtained at the outcrop.

  16. Evaluation of uncertainties in in situ and ex situ gamma measurements on land areas with low contamination levels.

    PubMed

    Rostron, Peter D; Heathcote, John A; Ramsey, Michael H

    2015-06-01

    Previous work on the characterisation of land areas with moderate contamination levels showed that in situ measurements made with a gamma detector can achieve lower levels of the random component of uncertainty than laboratory measurements of extracted samples. This was found when the variance caused by small-scale lateral heterogeneity of contaminants was included in the uncertainty estimation. The present paper documents the results of applying the same techniques of uncertainty estimation to an area with contamination levels that were lower by a factor of 10. If the same counting times were used, it would be expected that both measurement types would be affected by higher levels of random uncertainty in the individual measurements because of increased uncertainty from counting statistics and other factors such as interpretation of gamma spectra. However, when uncertainty due to sampling was included, it was found that both measurements methods were subject to similar combined uncertainties at individual locations. Using an assumption of the depth distributions of radionuclides that was supported by ex situ measurements, in situ measurements were able to produce averaging estimates with an approximate reduction of 50% in the standard error on the mean at ~50% of the cost of the ex situ measurements. PMID:25928900

  17. Miniaturized laser-induced plasma spectrometry for planetary in situ analysis - The case for Jupiter's moon Europa

    NASA Astrophysics Data System (ADS)

    Pavlov, S. G.; Jessberger, E. K.; Hbers, H.-W.; Schrder, S.; Rauschenbach, I.; Florek, S.; Neumann, J.; Henkel, H.; Klinkner, S.

    2011-08-01

    Jupiter's icy moon Europa is one of most promising places in our Solar System where possible extraterrestrial life forms could exist either in the past or even presently. The Europa Lander mission, an exciting part of the international Europa Jupiter System Mission (EJSM/Laplace), considers in situ planetary exploration of the moon. The distance of Europa from the Earth and the Sun asks for autonomous analytical tools that maximize the scientific return at minimal resources, demanding new experimental concepts. We propose a novel instrument, based on the atomic spectroscopy of laser generated plasmas for the elemental analysis of Europa's surface materials as far as it is in reach of the lander for example by a robotic arm or a mole, or just onboard the lander. The technique of laser-induced plasma spectrometry provides quantitative elemental analysis of all major and many trace elements. It is a fast technique, i.e. an analysis can be performed in a few seconds, which can be applied to many different types of material such as ice, dust or rocks and it does not require any sample preparation. The sensitivity is in the range of tens of ppm and high lateral resolution, down to 50 ?m, is feasible. In addition, it provides the potential of depth profiling, up to 2 mm in rock material and up to a few cm in more transparent icy matrices. Key components of the instrument are presently developed in Germany for planetary in situ missions. This development program is accompanied by an in-depth methodical investigation of this technique under planetary environmental conditions.

  18. High-Speed Tandem Mass Spectrometric in Situ Imaging by Nanospray Desorption Electrospray Ionization Mass Spectrometry

    SciTech Connect

    Lanekoff, Ingela T.; Burnum-Johnson, Kristin E.; Thomas, Mathew; Short, Joshua TL; Carson, James P.; Cha, Jeeyeon; Dey, Sudhansu K.; Yang, Pengxiang; Prieto Conaway, Maria C.; Laskin, Julia

    2013-10-15

    Nanospray desorption electrospray ionization (nano-DESI) combined with tandem mass spectrometry (MS/MS), high-resolution mass analysis (m/m=17,500 at m/z 200), and rapid spectral acquisition enabled simultaneous imaging and identification of more than 300 molecules from 92 selected m/z windows (± 1 Da) with a spatial resolution of better than 150 um. Uterine sections of implantation sites on day 6 of pregnancy were analyzed in the ambient environment without any sample pre-treatment. MS/MS imaging was performed by scanning the sample under the nano-DESI probe at 10 um/s while acquiring higher-energy collision-induced dissociation (HCD) spectra for a targeted inclusion list of 92 m/z values at a rate of ~6.3 spectra/s. Molecular ions and their corresponding fragments, separated using high-resolution mass analysis, were assigned based on accurate mass measurement. Using this approach, we were able to identify and image both abundant and low-abundance isobaric species within each m/z window. MS/MS analysis enabled efficient separation and identification of isobaric sodium and potassium adducts of phospholipids. Furthermore, we identified several metabolites associated with early pregnancy and obtained the first 2D images of these molecules.

  19. High-speed tandem mass spectrometric in situ imaging by nanospray desorption electrospray ionization mass spectrometry.

    PubMed

    Lanekoff, Ingela; Burnum-Johnson, Kristin; Thomas, Mathew; Short, Joshua; Carson, James P; Cha, Jeeyeon; Dey, Sudhansu K; Yang, Pengxiang; Prieto Conaway, Maria C; Laskin, Julia

    2013-10-15

    Nanospray desorption electrospray ionization (nano-DESI) combined with tandem mass spectrometry (MS/MS), high-resolution mass analysis of the fragment ions (m/?m = 17?500 at m/z 200), and rapid spectral acquisition enabled simultaneous imaging and identification of a large number of metabolites and lipids from 92 selected m/z windows (1 Da) with a spatial resolution of better than 150 ?m. Mouse uterine sections of implantation sites on day 6 of pregnancy were analyzed in the ambient environment without any sample pretreatment. MS/MS imaging was performed by scanning the sample under the nano-DESI probe at 10 ?m/s, while higher-energy collision-induced dissociation (HCD) spectra were acquired for a targeted inclusion list of 92 m/z values at a rate of ?6.3 spectra/s. Molecular ions and their corresponding fragments, separated by high-resolution mass analysis, were assigned on the basis of accurate mass measurement. Using this approach, we were able to identify and image both abundant and low-abundance isobaric and isomeric species within each m/z window. MS/MS analysis enabled efficient separation and identification of isomeric and isobaric phospholipids that are difficult to separate in full-scan mode. Furthermore, we identified several metabolites associated with early pregnancy and obtained the first 2D images of these molecules. PMID:24040919

  20. Mass spectrometry imaging: an expeditious and powerful technique for fast in situ lignin assessment in Eucalyptus.

    PubMed

    Arajo, Pedro; Ferreira, Mnica Siqueira; de Oliveira, Diogo Noin; Pereira, Luciano; Sawaya, Alexandra Christine Helena Frankland; Catharino, Rodrigo Ramos; Mazzafera, Paulo

    2014-04-01

    Plant biomass has been suggested as an alternative to produce bioethanol. The recalcitrance of plant biomass to convert cellulose into simpler carbohydrates used in the fermentation process is partially due to lignin, but the standard methods used to analyze lignin composition frequently use toxic solvents and are laborious and time-consuming. MS imaging was used to study lignin in Eucalyptus, since this genus is the main source of cellulose in the world. Hand-cut sections of stems of two Eucalyptus species were covered with silica and directly analyzed by matrix-assisted laser sesorption ionization (MALDI)-imaging mass spectrometry (MS). Information available in the literature about soluble lignin subunits and structures were used to trace their distribution in the sections and using a software image a relative quantification could be made. Matrixes routinely used in MALDI-imaging analysis are not satisfactory to analyze plant material and were efficiently substituted by thin layer chromatography (TLC) grade silica. A total of 22 compounds were detected and relatively quantified. It was also possible to establish a proportion between syringyl and guaiacyl monolignols, characteristic for each species. Because of the simple way that samples are prepared, the MALDI-imaging approach presented here can replace, in routine analysis, complex and laborious MS methods in the study of lignin composition. PMID:24451041

  1. Desorption corona beam ionisation (DCBI) mass spectrometry for in-situ analysis of adsorbed phenol in cigarette acetate fiber filter.

    PubMed

    Du, Wen; Tang, Li-Juan; Wen, Jian-Hui; Zhong, Ke-Jun; Jiang, Jian-Hui; Wang, Hua; Chen, Bo; Yu, Ru-Qin

    2015-01-01

    The study of spatial distribution characteristics of the adsorbed compounds for absorbent materials has significant importance in understanding the behaviors of aerosols while they migrating in the absorbent materials. Herein, for the first time, desorption corona beam ionization-mass spectrometry (DCBI-MS) has proposed for direct in-situ analysis of adsorbed aerosol for absorbent materials. DCBI is a novel atmospheric pressure chemical ionization (APCI)-related technique developed by our group in recent years. It can facilitate accurately localizing sampling by forming a visible thin corona beam and avoid the risk of sample contamination and matrix interference compared with other similar techniques. The advantages of DCBI-MS allow rapid screening of the spatial distribution characteristics of the adsorbed compounds for absorbent materials. The distribution characteristic of phenol in cigarette filter tip filled with cellulose acetate fiber was studied as a model case for demonstrating the feasibility of the developed method. As a comparison, conventional HPLC was also used for the study of the distribution characteristic of phenol. The results revealed DCBI-MS had highly improved assay simplicity in spatial distribution characteristic analysis of phenol for the acetate fiber tip, therefore, exhibiting a great potential for convenient, rapid and cost-efficient analysis of the spatial distribution characteristic investigation of adsorbed compounds for adsorbent materials. PMID:25281132

  2. Capillary injection device for in situ pre-concentration of trace elements in graphite furnace-atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Ceccarini, Alessio; Fuoco, Roger; Vecchio, Carolina

    2001-12-01

    A device for in situ pre-concentration of trace elements in graphite furnace-atomic absorption spectrometry (GF-AAS), which is based on the direct introduction of the sample solution into the furnace by a fused silica capillary, is described. Experimental conditions have been optimized for the determination of several elements at the sub pg/g level with a CV always better than 15%. A deposition yield of approximately 95% was estimated by depositing a solution containing NaCl 0.002 M. A very simple and effective device for handling a sample under contamination-free conditions is also described which allowed a CV less than 10% to be obtained for replicate determinations of Cd in blank samples at 0.4 pg/g. The overall analytical system was validated by recovery studies carried out on standard solutions and spiked snow samples. Measurements were performed at 1, 5 and 50 pg/g, and the error was always lower than 20, 10 and 5%, respectively. The evaluation of the experimental detection limits which ranged in the interval 0.1-4 pg/g is finally discussed.

  3. Use of airborne gamma-ray spectrometry for kaolin exploration

    NASA Astrophysics Data System (ADS)

    Tourlire, B.; Perrin, J.; Le Berre, P.; Pasquet, J. F.

    2003-08-01

    Airborne gamma-ray spectrometry was used to define targets with kaolin potential in the Armorican Massif of Brittany, France. This exploration method is based on the principle that kaolinite, an aluminosilicate clay mineral constituting kaolin, is formed by the hydrolysis of potash feldspar with the elimination of potassium. Therefore, potassium contrast between favourable host-rock such as a leucogranite and kaolin occurrence is likely a significant pathfinder. As the relationship between the potassium-40 recorded by an airborne gamma-ray spectrometer and total potassium is constant, such data provide us a direct measurement of the potassium content of the ground flown over. Our study tested this by calculating, for each geological unit, the difference between the measured and average potassium content calculated for a given geological formation. The study was based on (i) a recent (1998) high-definition airborne geophysical survey over the Armorican Massif undertaken on behalf of the French Government, and (ii) new geological compilation maps covering the same region. Depleted zones, where the measured potassium is less than the average potassium content calculated target areas with high potential of containing kaolin, provided that the unit was originally rich in potash feldspar. By applying this method to the entire Armorican Massif, it was possible to identify 150 potassium-depleted zones, including 115 that were subjected to rapid field checks and 36 that contained kaolin (21 new discoveries). This method, which is both safe for the environment and easy to use, is therefore a good tool for rapidly defining targets with kaolin potential at a regional scale. The method may also have possibilities in exploring for other types of deposit characterised by an enrichment or depletion in U, K and/or Th.

  4. In situ gamma ray measurements of radionuclides at a disused phosphate mine on the West Coast of South Africa.

    PubMed

    Bezuidenhout, Jacques

    2015-12-01

    High levels of uranium and its radioactive progeny like radium is normally associated with phosphate mining. In Situ gamma ray spectroscopy as a survey tool has been successfully applied to assess radionuclide concentrations in various geographical environments. A transportable and robust gamma ray detection system (GISPI) was therefore employed to determine the concentrations of naturally occurring radionuclides at a disused phosphate mine on the West Coast of South Africa. The concentrations of radium, thorium and potassium were measured and plotted. The measurements showed fairly high concentrations with medians of 320 Bq/kg for (226)Ra, 64 Bq/kg for (232)Th and 390 Bq/kg for (40)K. The highest concentrations were however confined to specific areas of the mine. The effective dose due to gamma irradiation for the various areas of the mine was also estimated and the highest estimated level was 0.45 mSv/y. The article finally draws conclusions as to the origins and impact of the radiation. PMID:26254719

  5. In situ assays demonstrate that interferon-gamma suppresses infection-stimulated hepatic fibrin deposition by promoting fibrinolysis

    PubMed Central

    Mullarky, Isis K.; Szaba, Frank M.; Winchel, Caylin G.; Parent, Michelle A.; Kummer, Lawrence W.; Mackman, Nigel; Johnson, Lawrence L.; Smiley, Stephen T.

    2010-01-01

    Summary Inflammatory cytokines potently impact hemostatic pathways during infection, but the tissue-specific regulation of coagulation and fibrinolysis complicates studies of the underlying mechanisms. Here, we describe assays that quantitatively measuring prothrombinase (PTase), protein C-ase (PCase) and plasminogen activator (PA) activities in situ, thereby facilitating studies of tissue-specific hemostasis. Using these assays, we investigate the mechanisms regulating hepatic fibrin deposition during murine toxoplasmosis and the means by which interferon-gamma (IFN?) suppresses infection-stimulated fibrin deposition. We demonstrate that Toxoplasma infection upregulates hepatic PTase, PCase, and PA activity. Wild type and gene-targeted IFN?-deficient mice exhibit similar levels of infection-stimulated PTase activity. By contrast, IFN?-deficiency is associated with increased PCase activity and reduced PA activity during infection. Parallel analyses of hepatic gene expression reveal that IFN?-deficiency is associated with increased expression of thrombomodulin (TM), a key component of the PCase, increased expression of thrombin-activatable fibrinolysis inhibitor (TAFI), a PC substrate, and reduced expression of urokinase PA (uPA). These findings suggest that IFN? suppresses infection-stimulated hepatic fibrin deposition by suppressing TM-mediated activation of TAFI, thereby destabilizing fibrin deposits, and concomitantly increasing hepatic uPA activity, thereby promoting fibrinolysis. We anticipate that further application of these in situ assays will improve our understanding of tissue-specific hemostasis, its regulation by cytokines, and its dysregulation during coagulopathy. PMID:16839357

  6. Active Neutron and Gamma Ray Instrumentation for In Situ Planetary Science Applications

    NASA Technical Reports Server (NTRS)

    Parsons, A.; Bodnarik, J.; Evans, L.; Floyd, S.; Lim, L.; McClanahan, T.; Namkung, M.; Schweitzer, J.; Starr, R.; Trombka, J.

    2010-01-01

    The Pulsed Neutron Generator-Gamma Ray And Neutron Detectors (PNG-GRAND) experiment is an innovative application of the active neutron-gamma ray technology so successfully used in oil field well logging and mineral exploration on Earth. The objective of our active neutron-gamma ray technology program at NASA Goddard Space Flight Center (NASA-GSFC) is to bring the PNG-GRAND instrument to the point where it can be flown on a variety of surface lander or rover missions to the Moon, Mars, Menus, asteroids, comets and the satellites of the outer planets. Gamma-Ray Spectrometers (GRS) have been incorporated into numerous orbital planetary science missions and, especially its the case of the Mars Odyssey GRS, have contributed detailed maps of the elemental composition over the entire surface of Mars. However, orbital gamma ray measurements have low spatial sensitivity (100's of km) due to their low surface emission rates from cosmic rays and subsequent need to be averaged over large surface areas. PNG-GRAND overcomes this impediment by incorporating a powerful neutron excitation source that permits high sensitivity surface and subsurface measurements of bulk elemental compositions. PNG-GRAND combines a pulsed neutron generator (PNG) with gamma ray and neutron detectors to produce a landed instrument to determine subsurface elemental composition without needing to drill into a planet's surface a great advantage in mission design. We are currently testing PNG-GRAND prototypes at a unique outdoor neutron instrumentation test facility recently constructed at NASA/GSFC that consists of a 2 m x 2 in x 1 m granite structure placed outdoors in an empty field. Because an independent trace elemental analysis has been performed on the material, this granite sample is a known standard with which to compare both Monte Carlo simulations and our experimentally measured elemental composition data. We will present data from operating PNG-GRAND in various experimental configurations on a known sample in a geometry that is identical to that on a planetary surface. We will also illustrate the use of gamma ray timing techniques to improve sensitivity and will compare the material composition results from our experiments to both an independent laboratory elemental composition analysis and MCNPX computer modeling results.

  7. Assessment of hand-held Raman instrumentation for in situ screening for potentially counterfeit artesunate antimalarial tablets by FT-Raman spectroscopy and direct ionization mass spectrometry.

    PubMed

    Ricci, Camilla; Nyadong, Leonard; Yang, Felicia; Fernandez, Facundo M; Brown, Christopher D; Newton, Paul N; Kazarian, Sergei G

    2008-08-15

    Pharmaceutical counterfeiting has become a significant public health problem worldwide and new, rapid, user-friendly, reliable and inexpensive methods for drug quality screening are needed. This work illustrates the chemical characterization of genuine and fake artesunate antimalarial tablets by portable Raman spectroscopy and validation by FT-Raman spectroscopy and ambient mass spectrometry. The applicability of a compact and robust portable Raman spectrometer (TruScan) for the in situ chemical identification of counterfeit tablets is reported. PMID:18620922

  8. A Team Approach to the Development of Gamma Ray and x Ray Remote Sensing and in Situ Spectroscopy for Planetary Exploration Missions

    NASA Technical Reports Server (NTRS)

    Trombka, J. I.; Floyd, S.; Ruitberg, A.; Evans, L.; Starr, R.; Metzger, A.; Reedy, R.; Drake, D.; Moss, C.; Edwards, B.

    1993-01-01

    An important part of the investigation of planetary origin and evolution is the determination of the surface composition of planets, comets, and asteroids. Measurements of discrete line X-ray and gamma ray emissions from condensed bodies in space can be used to obtain both qualitative and quantitative elemental composition information. The Planetary Instrumentation Definition and Development Program (PIDDP) X-Ray/Gamma Ray Team has been established to develop remote sensing and in situ technologies for future planetary exploration missions.

  9. Use of a Shielded High Resolution Gamma Spectrometry System to Segregate LLW from Contact Handleable ILW Containing Plutonium - 13046

    SciTech Connect

    Lester, Rosemary; Wilkins, Colin; Chard, Patrick; Jaederstroem, Henrik; LeBlanc, Paul; Mowry, Rick; MacDonald, Sanders; Gunn, William

    2013-07-01

    Dounreay Site Restoration Limited (DSRL) have a number of drums of solid waste that may contain Plutonium Contaminated Material. These are currently categorised as Contact Handleable Intermediate Level Waste (CHILW). A significant fraction of these drums potentially contain waste that is in the Low Level Waste (LLW) category. A Canberra Q2 shielded high resolution gamma spectrometry system is being used to quantify the total activity of drums that are potentially in the LLW category in order to segregate those that do contain LLW from CHILW drums and thus to minimise the total volume of waste in the higher category. Am-241 is being used as an indicator of the presence of plutonium in the waste from its strong 59.54 keV gamma-ray; a knowledge of the different waste streams from which the material originates allows a pessimistic waste 'fingerprint' to be used in order to determine an upper limit to the activities of the weak and non-gamma-emitting plutonium and associated radionuclides. This paper describes the main features of the high resolution gamma spectrometry system being used by DSRL to perform the segregation of CHILW and LLW and how it was configured and calibrated using the Canberra In-Situ Object Counting System (ISOCS). It also describes how potential LLW drums are selected for assay and how the system uses the existing waste stream fingerprint information to determine a reliable upper limit for the total activity present in each measured drum. Results from the initial on-site commissioning trials and the first measurements of waste drums using the new monitor are presented. (authors)

  10. Automated determination of tin by hydride generation using in situ trapping on stable coatings in graphite furnace atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Haug, Hermann O.; Yiping, Liao

    1995-09-01

    Conditions have been studied for the determination of Sn by coupling of hydride generation and graphite furnace atomic absorption spectrometry. Sequestering and in situ concentration of Sn hydride in the graphite furnace requires just a single application of a long-term stable trapping reagent for automated analyses. In a systematic study it is shown that effective trapping of stannane is possible on graphite tubes or platforms coated with a carbide-forming element such as Zr, Nb, Ta, or W at trapping temperatures of 500 to 600C. Trapping temperatures should not be higher than 600C (the "critical temperature") because otherwise at temperatures higher than 700C errors in absorbance values could occur by an adsorptive "carry-over effect". Signal stability and reproducibility are tested over more than 400 complete trapping and atomization cycles, and a precision of 2% is observed. Narrow peaks are obtained for all coatings except for Nb- and Ta-coated platforms where double peaks occur. Ir- or Pd/Ir-coated surfaces allow trapping of stannane at lower temperatures but the signal stability (especially in the case of Pd/Ir coating) is lower than with the carbide-forming element coatings. The highest sensitivity is found for Zr- and W-coated tubes with a characteristic mass of about 17 and 20 pg, respectively, and the calibration curves are linear up to 2 ng Sn on Zr-treated tubes (peak height) and 4 ng on Zr-coated platforms (integrated absorbance) using the 286.3 nm line. The detection limit is 25 pg for a 1 ml sample volume, and the reagent blank is still significant with the purest available chemicals. The method is tested by determination of Sn in low alloy steel samples.

  11. In-situ gamma-ray assay of the west cell line in the 235-F plutonium fuel form facility

    SciTech Connect

    Couture, A. H.; Diprete, D.

    2014-09-01

    On August 29th, 2013, scientists from SRNL took a series of in-situ gamma-ray measurements in the maintenance trench beneath Cells 6-9 on the west line of the PuFF facility using an uncollimated, highpurity germanium detector. The detector efficiency was estimated using a combination of MCNP simulations and empirical measurements. Data analysis was performed using three gamma-rays emitted by Pu-238 (99.85 keV, 152.7 keV, and 766.4 keV) providing three independent estimates of the mass of Pu-238 holdup in each of the cells. The weighted mean of these three results was used as the best estimate of Pu-238 holdup in the West Cell Line of PuFF. The results of the assay measurements are found in the table below along with the results from the scoping assay performed in 2006. All uncertainties in this table (as well as the rest of the report) are given as 1σ. The total holdup in the West Cell Line was 2.4 ± 0.7 grams. This result is 0.6 g higher than the previous estimate, a 0.4σ difference.

  12. Gamma irradiation testing of montan wax barrier materials for in-situ waste containment

    SciTech Connect

    Soo, P.; Heiser, J.

    1996-02-01

    A scoping study was carried out to quantify the potential use of a montan wax as a barrier material for subsurface use. If it possesses resistance to chemical and structural change, it could be used in a barrier to minimize the migration of contaminants from their storage or disposal locations. Properties that were evaluated included hardness, melting point, molecular weight, and biodegradation as a function of gamma radiation dose. The main emphasis was to quantify the wax`s long-term ability to withstand radiation-induced mechanical, chemical, and microbial degradation.

  13. Low level measurement of (60)Co by gamma ray spectrometry using γ-γ coincidence.

    PubMed

    Paradis, H; de Vismes Ott, A; Luo, M; Cagnat, X; Piquemal, F; Gurriaran, R

    2016-03-01

    This paper presents the latest development of the laboratory to measure the natural and artificial massic activities in environmental samples. The measurement method of coincident emitters by gamma-gamma coincidence using an anti-Compton device and its digital electronics is described. Results obtained with environmental samples are shown. Despite its low efficiency, this method decreases detection limits of (60)Co for certain samples compared to conventional gamma-ray spectrometry due to its very low background. PMID:26682892

  14. In situ trace element determination of carbonates by laserProbe inductively coupled plasma mass spectrometry using nonmatrix matched standardization

    NASA Astrophysics Data System (ADS)

    Feng, Rui

    1994-03-01

    The LaserProbe Inductively Coupled Plasma Mass Spectrometry (LP-ICP-MS) has shown great potential to precisely and quickly determine trace element compositions of minerals in situ at a scale of ? 60 ?m. However, standardization is complicated, due to the lack of matrix-matched, homogeneous mineral standards. In this study, a nonmatrix matched calibration standard, the NIST 612 silicate glass, was employed to determine Sr, Y, Ba and REE concentrations in calcite and dolomite grain mounts. Using 43Ca as an internal standard, the results demonstrate that it is not essential to have a matrix-matched mineral standard by LP-ICP-MS. Routine limits of detection are ~10 ppb for REEs and ~200 ppb for Sr, Y and Ba, depending on laser operating conditions. Evaluation of precision and accuracy is made complex by heterogeneity of trace elements within single mineral grains. However, the best within-grain precision (determined from several LP sampling pits within an individual mineral grain) is considered to represent the maximum analytical error and is generally <5% RSD for REEs ? 1 ppm, <10% RSD for REEs between 0.1-1 ppm and ~ 15-25% for lower concentrations. Accuracy was established through comparison of LP-ICP-MS results with those of solution ICP-MS analysis of bulk calcite and dolomite powders and is generally better than 10% for relatively homogeneous samples and also for heterogeneous samples when large numbers of grains (>10 grains) were analyzed. Nonmatrix matched standardization for quantitative analysis can successfully be used, because the small size laser probe ( ~ 10 ?m) used in this study can generate much higher power density than the conventional size laser beam. At high power density, the sample ablation mainly results from plasma plume expansion induced by the laser, not from absorption of the laser beam and related thermal vaporization, as for conventional, low power density laser analysis. The plasma plume expansion as a major ablation process permits the ablation of even those materials usually transparent to laser (e.g., calcite). This technique can be applied to the analysis of trace elements of carbonates in thin sections, grain mounts and rock or mineral chips, thus avoiding extensive sample preparation with significant implications for studies of near-surface and environmental processes.

  15. Sapphire: a better material for atomization and in situ collection of silver volatile species for atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Musil, Stanislav; Matouek, Tom; D?dina, Ji?

    2015-06-01

    Sapphire is presented as a high temperature and corrosion resistant material of an optical tube of an atomizer for volatile species of Ag generated by the reaction with NaBH4. The modular atomizer design was employed which allowed to carry out the measurements in two modes: (i) on-line atomization and (ii) in situ collection (directly in the optical tube) by means of excess of O2 over H2 in the carrier gas during the trapping step and vice versa in the volatilization step. In comparison with quartz atomizers, the sapphire tube atomizer provides a significantly increased atomizer lifetime as well as substantially improved repeatability of the Ag in situ collection signals shapes. In situ collection of Ag in the sapphire tube atomizer was highly efficient (> 90%). Limit of detection in the on-line atomization mode and in situ collection mode, respectively, was 1.2 ng ml- 1 and 0.15 ng ml- 1.

  16. Monte carlo simulation of in situ gamma-spectra recorded by NaI (Tl) detector in the marine environment

    NASA Astrophysics Data System (ADS)

    Wang, Yiming; Zhang, Yingying; Wu, Ning; Wu, Bingwei; Liu, Yan; Cao, Xuan; Wang, Qian

    2015-06-01

    To develop a NaI (Tl) detector for in situ radioactivity monitoring in the marine environment and enhance the confidence of the probability of the gamma-spectrum analysis, Monte Carlo simulations using the Monte Carlo N-Particle ( MNCP ) code were performed to provide the response spectra of some interested radionuclides and the background spectra originating from the natural radionuclides in seawater recorded by a NaI (Tl) detector. A newly developed 75 mm 75 mm NaI (Tl) detector was calibrated using four reference radioactive sources 137Cs, 60Co, 40K and 54Mn in the laboratory before the field measurements in seawater. A simulation model was established for the detector immersed in seawater. The simulated spectra were all broadened with Gaussian pulses to reflect the statistical fluctuations and electrical noise in the real measurement. The simulated spectra show that the single-energy photons into the detector are mostly scattering low-energy photons and the high background in the low energy region mainly originates from the Compton effect of the high energy ?-rays of natural radionuclides in seawater. The simulated background spectrum was compared with the experimental one recorded in field measurement and they seem to be in good agreement. The simulation method and spectra can be used for the accurate analysis of the filed measurement results of low concentration radioactivity in seawater.

  17. QUALITY CONTROL FOR ENVIRONMENTAL MEASUREMENTS USING GAMMA-RAY SPECTROMETRY

    EPA Science Inventory

    This report describes the quality control procedures, calibration, collection, analysis, and interpretation of data in measuring the activity of gamma ray-emitting radionuclides in environmental samples. Included in the appendices are basic data for selected gamma ray-emitting ra...

  18. ADONIS, high count-rate HP-Ge {gamma} spectrometry algorithm: Irradiated fuel assembly measurement

    SciTech Connect

    Pin, P.; Barat, E.; Dautremer, T.; Montagu, T.; Normand, S.

    2011-07-01

    ADONIS is a digital system for gamma-ray spectrometry, developed by CEA. This system achieves high count-rate gamma-ray spectrometry with correct dynamic dead-time correction, up to, at least, more than an incoming count rate of 3.10{sup 6} events per second. An application of such a system at AREVA NC's La Hague plant is the irradiated fuel scanning facility before reprocessing. The ADONIS system is presented, then the measurement set-up and, last, the measurement results with reference measurements. (authors)

  19. Nondestructive determination of plutonium by gamma spectrometry and neutron well coincidence counting

    NASA Astrophysics Data System (ADS)

    Agarwal, Chhavi; Poi, Sanhita; Nathaniel, T. N.; Mhatre, Amol; Kalsi, P. C.; Singh, Sarbjit; Goswami, A.

    2009-03-01

    Different NDA methods based on gamma ray and neutron measurements developed for the determination of Pu in solid samples is reported. In the gamma spectrometric measurements for solid samples, a method which takes advantage of the multiple ?-rays emitted by Pu and relies on the empirical relation between apparent mass of the sample and ?-ray energy was used. The method is applicable for the determination of small quantities of plutonium samples of non standard geometry by gamma ray spectrometry. The gross and coincidence neutron count rates for two different sets of standard Pu oxide powder samples were found to fall on different calibration lines. Isotopic composition of the two sets were determined using gamma ray spectrometry to obtain effective 240Pu content in the samples. A common calibration curve could be obtained when coincidence count rates were plotted vs. effective 240Pu content.

  20. Comparison between in situ and ex situ gamma measurements on land areas within a decommissioning nuclear site: a case study at Dounreay.

    PubMed

    Rostron, Peter D; Heathcote, John A; Ramsey, Michael H

    2014-09-01

    Measurements made in situ with gamma detectors and ex situ measurements of soil samples in a laboratory can have complementary roles in the assessment of radioactively contaminated land on decommissioning nuclear sites. Both in situ and ex situ methods were used to characterize (137)Cs contamination within an area at the Dounreay site in Scotland. The systematic difference (bias) between estimates of the mean activity concentration was found to be non-significant when in situ measurements were interpreted using a linear depth model, based on ex situ measurements made at two different depths. An established method of evaluating the random components of measurement uncertainty was used. The random component of analytical uncertainty in the in situ measurements, made in field conditions, was found to exceed that for the ex situ measurements, made in the controlled conditions of a laboratory. However, contamination by the target radionuclide was found to be heterogeneous over small spatial scales. This resulted in significantly higher levels of random sampling uncertainty in individual ex situ measurements. As in situ measurements are substantially less costly, a greater number of measurements can be made, which potentially reduces the uncertainty on the mean. Providing the depth profile of contaminants can be modelled with confidence, this can enable estimates of mean activity concentration over an averaging area to be made with lower overall uncertainties than are possible using ex situ methods. PMID:24938421

  1. In-situ gamma-ray assay of the east cell line in the 235-F Plutonium fuel form facility

    SciTech Connect

    Diprete, D.

    2015-08-21

    On September 17th -19th , 2013, scientists from SRNL took a series of in-situ gamma-ray measurements in the maintenance trench beneath Cells 1-5 on the east line of the PuFF facility using a well-collimated, high-purity germanium detector. The cell interiors were assayed along with the furnaces and storage coolers that protrude beneath the cells. The detector efficiency was estimated using a combination of MCNP simulations and empirical measurements. Data analysis was performed using three gamma-rays emitted by Pu-238 (99.85 keV, 152.7 keV, and 766.4 keV) providing three independent estimates of the mass of Pu-238 holdup in each of the cells. The weighted mean of these three results was used as the best estimate of Pu-238 holdup in the East Cell Line of PuFF. The results of the assay measurements are found in the table on the following page along with the results from the scoping assay performed in 2006. All uncertainties in this table (as well as the rest of the report) are reported at 1σ. Summing the assay results and treating MDAs as M238Pu= 0 ± MDA, the total holdup in the East Cell Line was 240 ± 40 grams. This result is 100 grams lower than the previous estimate, a 0.55σ difference. The uncertainty in the Pu-238 holdup is also reduced substantially relative to the 2006 scoping assay. However, the current assay results are in agreement with the 2006 scoping assay results due to the large uncertainty associated with the 2006 scoping assays. The current assay results support the conclusion that the 2006 results bound the Pu-238 mass in Cells 1-5. These results should be considered preliminary since additional measurements of the East Cell line are scheduled for 2017 and 2018. Those measurements will provide detailed information about the distribution of Pu-238 in the cells to be used to refine the results of the current assay.

  2. In situ metathesis ionic liquid formation dispersive liquid-liquid microextraction for copper determination in water samples by electrothermal atomic absorption spectrometry.

    PubMed

    Stanisz, Ewa; Zgo?a-Grze?kowiak, Agnieszka

    2013-10-15

    In situ synthesis of ionic liquid extractant for dispersive liquid-liquid microextraction (in situ IL DLLME) combined with electrothermal atomic absorption spectrometry (ET AAS) for determination of copper in water samples was developed. Analytical signals were obtained without the back-extraction of copper from the IL phase prior to its determination by AAS. Some essential parameters of the microextraction and detection techniques such as the pH of sample solution, volume of components for in situ synthesis, matrix interferences and main parameters of graphite furnace atomizer have been studied. Under optimal conditions, high extraction efficiency for copper was achieved for the extraction of 0.7 g L(-1) in 10.0 mL of sample solution employing 8 ?L of 1-hexyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide (HmimNTf2) as the extraction solvent. The detection limit was found as 0.004 g L(-1) with an enrichment factor of 200. The relative standard deviation (RSD) for seven replicate measurements of 0.7 g L(-1) in sample solution was 4%. The accuracy of the proposed method was evaluated by analysis of the Certified Reference Materials: NIST SRM 2709 (San Joaquin Soil), NBS SRM 2704 (Buffalo River Sediment), NRCC DOLT-2 (Dogfish Liver) and NIST SRM 1643e (Trace Element in Water). The measured copper contents in the reference materials were in satisfactory agreement with the certified values. The method was successfully applied to analysis of the tap, lake and mineral water samples. PMID:24054576

  3. Fission studies by prompt gamma-ray spectrometry

    NASA Astrophysics Data System (ADS)

    Materna, T.; Letourneau, A.; Amouroux, Ch.; Marchix, A.; Litaize, O.; Sérot, O.; Regnier, D.; Blanc, A.; Jentschel, M.; Köster, U.; Mutti, P.; Soldner, T.; Simpson, G.; Leoni, S.; de France, G.; Urban, W.

    2015-05-01

    The feasibility of retrieving accurate fission observables with a Ge-detector array around a fissile target placed in a cold neutron beam was tested. In three measurement campaigns performed at ILL with the EXILL setup, 235U and 241Pu targets were placed in the high flux cold neutron beam available at the PF1B neutron guide. Gamma-rays following fission were detected by an array of 16 Ge detectors. In the following study, part of data was analyzed as a proof of principle. A set of yields belonging to the Kr-Ba pair were extracted using a gamma-gamma coincidence technique. Preliminary results were compared to the predictions of two phenomenological models: GEF and FIFRELIN.

  4. Pulser injection with subsequent removal for gamma-ray spectrometry

    DOEpatents

    Hartwell, Jack K. (Idaho Falls, ID); Goodwin, Scott G. (Idaho Falls, ID); Johnson, Larry O. (Blackfoot, ID); Killian, E. Wayne (Idahoe Falls, ID)

    1990-01-01

    An improved system for gamma-ray spectroscopy characterized by an interface module that controls the injection of electronic pulses as well as separation logic that enables storage of pulser events in a region of the spectrum of a multichannel analyzer distinct from the region reserved for storage of gamma-ray events. The module accomplishes this by tagging pulser events (high or low) injected into the amplification circuitry, adding an offset to the events so identified at the time the events are at the output of the analog to digital converter, and storing such events in the upper portion of the spectrum stored in the multichannel analyzer. The module can be adapted for use with existing gamma-ray spectroscopy equipment to provide for automatic analyses of radioisotopes.

  5. Plutonium isotopic analysis of nondescript samples by gamma-ray spectrometry

    SciTech Connect

    Gunnink, R.

    1981-09-01

    A gamma-ray spectrometry system has been developed for the Savannah River Plant that when coupled with calorimetry will allow a complete nondestructive assay of various plutonium product and waste materials contained in sealed cans. The computer-based system employs two germanium detectors to obtain spectral information that is analyzed in a unique fashion to obtain plutonium isotopic ratios.

  6. Characterization of coal and charcoal by alpha-particle and gamma-ray spectrometry

    NASA Astrophysics Data System (ADS)

    Carrasco Lourtau, A. M.; Rubio Montero, M. P.; Jurado Vargas, M.

    2015-11-01

    Although coal and charcoal have similar physical and chemical characteristics, there are several crystallographic procedures used to distinguish and characterize them. But if the matrix is crushed, there is no standard procedure to distinguish coal from charcoal. In this work, a procedure to characterize coal and charcoal samples based on the radioactive content is proposed. The first assay is by gamma-ray spectrometry, which allows a part of the radioactive content to be determined rapidly and non-destructively. Then, alpha-particle spectrometry is applied to assay the content of those radionuclides which are difficult to determine precisely by gamma-ray spectrometry. This second technique requires prior chemical purification of the carbon sample in order to separate the corresponding radionuclides of interest.

  7. Development and calibration of a real-time airborne radioactivity monitor using direct gamma-ray spectrometry with two scintillation detectors.

    PubMed

    Casanovas, R; Morant, J J; Salvad, M

    2014-07-01

    The implementation of in-situ gamma-ray spectrometry in an automatic real-time environmental radiation surveillance network can help to identify and characterize abnormal radioactivity increases quickly. For this reason, a Real-time Airborne Radioactivity Monitor using direct gamma-ray spectrometry with two scintillation detectors (RARM-D2) was developed. The two scintillation detectors in the RARM-D2 are strategically shielded with Pb to permit the separate measurement of the airborne isotopes with respect to the deposited isotopes.In this paper, we describe the main aspects of the development and calibration of the RARM-D2 when using NaI(Tl) or LaBr3(Ce) detectors. The calibration of the monitor was performed experimentally with the exception of the efficiency curve, which was set using Monte Carlo (MC) simulations with the EGS5 code system. Prior to setting the efficiency curve, the effect of the radioactive source term size on the efficiency calculations was studied for the gamma-rays from (137)Cs. Finally, to study the measurement capabilities of the RARM-D2, the minimum detectable activity concentrations for (131)I and (137)Cs were calculated for typical spectra at different integration times. PMID:24607535

  8. Monitoring of Martian atmosphere with gamma-ray spectrometry

    NASA Astrophysics Data System (ADS)

    Gasnault, O.; D'Uston, C.; Forni, O.; Maurice, S.

    Mars Odyssey has been monitoring the leakage gamma-rays from Mars since 2002 [1]. The spectrum of these gamma-rays is made of a dominating continuum plus lines (only 4% of the count rates) [2]. The latter have been used to build compositional maps of the surface [3]; the former can be analyzed to monitor atmospheric variations with time and place [4, 5]. Sometimes both aspects can be combined when during polar winters it is possible to track the argon in the atmosphere through its discrete gamma-ray line [6]. The Martian atmosphere is quite transparent (free mean path of about 100km) at these energies (100 keV - 10 MeV), and consequently the continuum varies by only a few percents over the Martian year. However the statistics are good enough to see these variations. Previous studies revealed short and long term time variations, as well as regional differences. In particular we noticed earlier that the atmospheric cycle looks slightly different from one year to the other. Deep basins (Argyre and Hellas) seem also to act as reservoirs at some seasons. We will present an update of the study of the gamma-ray continuum, including the latest data available, in terms of transparency of the Martian atmosphere. [1] Boynton et al. (2004) Space Sci. Rev., 110 (1), 37-83; [2] Evans et al. (2006) J. Geophys. Res., accepted; [3] Boynton et al. (2006) J. Geophys. Res., in preparation; [4] Gasnault et al. (2003) LPSC 34, abstract #1649 CD-ROM; [5] Gasnault et al. (2005) 1st Mars Express Sci. Conf., Noordwijk, Netherlands; [6] Sprague et al. (2006) J. Geophys. Res., accepted.

  9. On line gamma-ray spectrometry at open sea.

    PubMed

    Tsabaris, C; Ballas, D

    2005-01-01

    Set up and application of a stationary monitoring network for measuring specific gamma- activities in the Aegean Sea are described. Three NaI scintillator based spectrometers have been used to detect the gamma rays. The gross counting rate of each system was found to be nearly constant, when there was no rainfall. The volumetric activity of the natural gamma-ray emitter 40K in open sea varied from 12,200 to 13,000 Bq/m3. The counting rate for 1461 keV 40K radiation was measured by intercalibration with an appropriate salinity sensor mounted close to the NaI-detector system. A simple relation between the counting rate and the salt concentration has been observed. The amount of the artificial radioactivity from 137Cs was increased up to seven times higher after strong rainfall, compared to the radiation level as given in literature (3.5-5.5 Bq/m3), while the 214Bi counting rate was increased up to ten times compared to the data without rainfall. PMID:15498689

  10. Latent transforming growth factor beta1 activation in situ: quantitative and functional evidence after low-dose gamma-irradiation

    NASA Technical Reports Server (NTRS)

    Ehrhart, E. J.; Segarini, P.; Tsang, M. L.; Carroll, A. G.; Barcellos-Hoff, M. H.; Chatterjee, A. (Principal Investigator)

    1997-01-01

    The biological activity of transforming growth factor beta1 (TGF-beta) is controlled by its secretion as a latent complex in which it is noncovalently associated with latency-associated peptide (LAP). Activation is the extracellular process in which TGF-beta is released from LAP, and is considered to be a primary regulatory control. We recently reported rapid and persistent changes in TGF-beta immunoreactivity in conjunction with extracellular matrix remodeling in gamma-irradiated mouse mammary gland. Our hypothesis is that these specific changes in immunoreactivity are indicative of latent TGF-beta activation. In the present study, we determined the radiation dose response and tested whether a functional relationship exists between radiation-induced TGF-beta and collagen type III remodeling. After radiation exposures as low as 0.1 Gy, we detected increased TGF-beta immunoreactivity in the mammary epithelium concomitant with decreased LAP immunostaining, which are events consistent with activation. Quantitative image analysis demonstrated a significant (P=0.0005) response at 0.1 Gy without an apparent threshold and a linear dose response to 5 Gy. However, in the adipose stroma, loss of LAP demonstrated a qualitative threshold at 0.5 Gy. Loss of LAP paralleled induction of collagen III immunoreactivity in this tissue compartment. We tested whether TGF-beta mediates collagen III expression by treating animals with TGF-beta panspecific monoclonal antibody, 1D11.16, administered i.p. shortly before irradiation. Radiation-induced collagen III staining in the adipose stroma was blocked in an antibody dose-dependent manner, which persisted through 7 days postirradiation. RNase protection assay revealed that radiation-induced elevation of total gland collagen III mRNA was also blocked by neutralizing antibody treatment. These data provide functional confirmation of the hypothesis that radiation exposure leads to latent TGF-beta activation, support our interpretation of the reciprocal shift in immunoreactivity as evidence of activation, and implicate TGF-beta as a mediator of tissue response to ionizing radiation. The sensitivity of activation to low radiation doses points to a potential role for TGF-beta in orchestrating tissue response to oxidative stress. As such, radiation may be useful as a probe to delineate the consequences of latent TGF-beta activation in situ.

  11. In situ production of gamma interferon, interleukin-4, and tumor necrosis factor alpha mRNA in human lung tuberculous granulomas.

    PubMed

    Fenhalls, G; Wong, A; Bezuidenhout, J; van Helden, P; Bardin, P; Lukey, P T

    2000-05-01

    Human tuberculous granulomas from five adults undergoing surgery for hemoptysis were analyzed by nonradioactive in situ hybridization for tumor necrosis factor alpha (TNF-alpha), gamma interferon (IFN-gamma), and interleukin-4 (IL-4) gene expression. All of the patients produced TNF-alpha mRNA. Three patients stained positive for both IFN-gamma and IL-4 mRNA; the other two stained positive for IFN-gamma but not IL-4 mRNA. Heterogeneity between the granulomas was observed in those patients staining positive for both IFN-gamma and IL-4 mRNA; these patients exhibited granulomas having IFN-gamma and not IL-4 mRNA as well as granulomas positive for both cytokine mRNAs. There was no evidence of caseation in these granulomas, and the cytokine patterns may represent events in the evolution of the granuloma. However, in those granulomas exhibiting caseous necrosis, very little IFN-gamma or IL-4 mRNA was observed, implying that progression of the granuloma is accompanied by a down regulation of T-cell responses. TNF-alpha mRNA expression was highest in patients with both IFN-gamma and IL-4 mRNA. Populations of CD68 positive macrophage-like cells within the granulomas produce mRNA for TNF-alpha, IFN-gamma, and IL-4. This implies that macrophages within the tuberculous granuloma may not be dependent on T-cell cytokines for modulation of their function but may be able to regulate their own activation state and that of the surrounding T cells. These findings have implications on the delivery of immunotherapies to patients with tuberculosis. PMID:10768979

  12. Natural Radiation from Soil using Gamma-Ray Spectrometry

    SciTech Connect

    Silveira, M. A. G.; Moreira, R. H.; Paula, A. L. C. de; Medina, N. H.

    2009-06-03

    We have studied the distribution of natural radioactivity in the soil of Interlagos, in Sao Paulo city and Billings Reservoir, in Sao Bernardo do Campo, Sao Paulo, Brazil. The main contribution of the effective radiation dose is due to the elements of the {sup 238}Th decay series, with smaller contributions from {sup 40}K and the elements of the series of {sup 238}U. The results indicate the dose in all of the studied areas is around the average international dose due to external exposure to gamma rays (0.48 mSv/yr) proceeding from natural terrestrial elements.

  13. Centromere detection in vinblastine- and radiation-induced micronuclei of cytokinesis-blocked mouse cells by using in situ hybridization with a mouse gamma (major) satellite DNA probe

    SciTech Connect

    Salassidis, K.; Huber, R.; Zitzelsberger, H.; Bauchinger, M. )

    1992-01-01

    Non-isotopic in situ hybridization using a mouse gamma (major) satellite probe DNA was applied to detect centromeres in micronuclei, which were induced in vitro mouse liver cells by ionizing radiation and by vinblastine sulfate. In a cytokinesis-blocked micronucleus assay a dose-dependent induction of micronuclei was found for both agents. After vinblastine exposure the observed micronuclei showed centromere-positive hybridization signals in an order of magnitude of 70-91%, but after radiation exposure the magnitude was only 10-20%. Since the in situ hybridization technique detects centromeric DNA directly, it can be used in a cytokinesis-blocked micronucleus assay for a rapid and reliable discrimination between aneuploidy-inducing and clastogenic agents.

  14. Gamma ray spectrometry of LDEF samples at SRL

    NASA Astrophysics Data System (ADS)

    Winn, W. G.

    1991-07-01

    A total of 31 samples from the Long Duration Exposure Facility (LDEF), including materials of aluminum, vanadium, and steel trunnions were analyzed by ultra-low-level gamma spectroscopy. The study quantified particle induced activations of Na-22, Sc-46, Cr-51, Mn-54, Co-56, Co-57, Co-58, and Co-60. The samples of trunnion sections exhibited increasing activity toward the outer end of the trunnion and decreasing activity toward its radial center. The trunnion sections did not include end pieces, which have been reported to collect noticeable Be-7 on their leading surfaces. No significant Be-7 was detected in the samples analyzed. The Underground Counting Facility at Savannah River Laboratory (SRL) was used in this work. The facility is 50 ft. underground, constructed with low-background shielding materials, and operated as a clean room. The most sensitive analyses were performed with a 90 percent efficient HPGe gamma-ray detector, which is enclosed in a purged active/passive shield. Each sample was counted for one to six days in two orientations to yield more representative average activities for the sample. The non-standard geometries of the LDEF samples prompted the development of a novel calibration method, whereby the efficiency about the samples surfaces (measured with point sources) predicted the efficiency for the bulk sample.

  15. Messenger RNA Detection in Leukemia Cell lines by Novel Metal-Tagged in situ Hybridization using Inductively Coupled Plasma Mass Spectrometry.

    PubMed

    Ornatsky, Olga I; Baranov, Vladimir I; Bandura, Dmitry R; Tanner, Scott D; Dick, John

    2006-01-01

    Conventional gene expression profiling relies on using fluorescent detection of hybridized probes. Physical characteristics of fluorophores impose limitations on achieving a highly multiplex gene analysis of single cells. Our work demonstrates the feasibility of using metal-tagged in situ hybridization for mRNA detection by inductively coupled plasma mass spectrometry (ICP-MS). ICP-MS as an analytical detector has a number of unique and relevant properties: 1) metals and their stable isotopes generate non-overlapping distinct signals that can be detected simultaneously; 2) these signals can be measured over a wide dynamic range; 3) ICP-MS is quantitative and very sensitive. We used commercial antibodies conjugated to europium (Eu) and gold together with biotinylated oligonucleotide probes reacted with terbium-labeled streptavidin to demonstrate simultaneous mRNA and protein detection by ICP-MS in leukemia cells. PMID:23662035

  16. Photosensitized degradation kinetics of trace halogenated contaminants in natural waters using membrane introduction mass spectrometry as an in situ reaction monitor.

    PubMed

    Letourneau, Dane R; Gill, Chris G; Krogh, Erik T

    2015-11-01

    The photochemically mediated dechlorination of polyhalogenated compounds represents a potential decontamination strategy and a relevant environmental process in chemically reducing media. We report the UV irradiation of natural and artificial waters containing natural dissolved organic matter to effect the photo-sensitized degradation of chlorinated organic compounds, including tetrachloromethane, 1,1,1-tricloroethane, perchloroethene, 1,2-dibromo-3-chloropropane and chlorobenzene at trace (ppb) levels in aqueous solution. The degradation kinetics are followed in situ using membrane introduction mass spectrometry. By re-circulating the reaction mixture in a closed loop configuration over a semi-permeable hollow fiber polydimethylsiloxane membrane in a flow cell interface, volatile and semi-volatile compounds are continuously monitored using a quadrupole ion trap mass spectrometer. The time resolved quantitative information provides useful mechanistic insights, including kinetic data. Pseudo first-order rate constants for the degradation of contaminant mixtures in natural waters are reported. PMID:26439106

  17. In situ Measurement of Pore-Water pH in Anoxic Sediments Using Laser Raman Spectrometry

    NASA Astrophysics Data System (ADS)

    Peltzer, E. T.; Luna, M.; Walz, P. M.; Zhang, X.; Brewer, P. G.

    2010-12-01

    Accurate measurement of the geochemical properties of sediment pore waters is of fundamental importance in ocean geochemistry and microbiology. Recent work has shown that the properties of pore waters can be measured rapidly in situ with a novel Raman based insertion probe (Zhang et al., 2010), and that data obtained from anoxic sediments on in situ dissolved methane concentrations are very different (~30x) than from recovered cores due the large scale degassing that occurs during core recovery (Zhang et al., submitted). Degassing of methane must carry with it via Henrys Law partioning significant quantities of H2S, which is clearly detectable by smell during sample processing, and thus in situ measurement of H2S is also highly desirable. In practice, dissolved H2S is partitioned between the HS- and H2S species as a function of pH with pKa ~7 for the acid dissociation reaction. Since both species are Raman active full determination of the sulfide system is possible if the relative Raman cross sections are known. The diagenetic equations for these reactions are commonly summarized as: 2CH2O + SO4= ? 2HCO3- + H2S CH4 + SO4= ? HCO3- + HS- + H2O Three of the major components of these equations, CH4, SO4=, and H2S/HS-, are all observable directly by Raman spectroscopy; but the detection of HCO3- presents a challenge due to its low Raman cross section and thus poor sensitivity. We show that pore water pH, which is a good estimator of HCO3- if total CO2 or alkalinity are known, can be measured by observing the H2S / HS- ratio via the equation: pH = pKa + log([HS-]/[H2S]) thereby fully constraining these equations within a single measurement protocol. The Raman peak for HS- is at 2573 cm-1 and for H2S is at 2592 cm-1; thus the peaks are well separated and may easily be deconvoluted from the observed spectrum. We have determined the relative Raman cross sections by a series of laboratory measurements over a range of pH and by using the definition that when pH = pKa then the mole fractions are equal. We find by this means that the HS-/H2S factor is 2.744:1. We report here both the process for determining the relative Raman cross-sections and show the application of the technique via deconvolution of the species present in the spectra. We present results of in situ pore water measurements made on highly reducing sediments on the Santa Monica Basin Mounds and determine the in situ pH to have a mean value of 7.12 at 20 - 30 cm insertion depth into a zone of dense bacterial mat. References: Zhang, X., P.M. Walz, W.J. Kirkwood, K.C. Hester, W.Ussler, E.T. Peltzer, P.G. Brewer (2010). Development and deployment of a deep-sea Raman probe for measurement of pore water geochemistry. Deep-Sea Res. I 57: 297-306. Zhang, X., K.C. Hester, W. Ussler, P.M. Walz, E.T. Peltzer, P.G. Brewer (submitted). Observing Deep Ocean Sediment Methane Concentrations. Science.

  18. Rapid analysis of 226Ra in waters by gamma-ray spectrometry.

    PubMed

    Johnston, A; Martin, P

    1997-05-01

    Techniques for the determination of 226Ra in waters by gamma-ray spectrometry are examined, with an emphasis on methods capable of completion within 1-3 days of sample collection. Methods discussed utilise either: (i) the 186 keV 226Ra gamma ray, with the contribution from 235U being subtracted after a separate uranium determination, or (ii) measurement of ingrowing 222Rn progeny. An analysis of the statistical and systematic errors associated with each technique is presented. Examples are given of their application to analysis of uranium mine process waters. PMID:9204522

  19. Rechargeable alkaline manganese dioxide batteries. I - In situ X-ray diffraction investigation of the H(+)/gamma-MnO2 (EMD-type) insertion system

    NASA Astrophysics Data System (ADS)

    Mondoloni, Christian; Laborde, Marc; Rioux, Jacques; Andoni, Edouard; Levy-Clement, Claude

    1992-04-01

    The influence of the electrochemical insertion and deinsertion of H(+) on the evolution of the crystallographic structure of EMD-type gamma-MnO2 insertion system during the discharge and recharge of an alkaline H(+)/MnO2 battery was investigated using in situ XRD observations. Results of voltage measurements are presented together with XRD profiles and measurements of variations of lattice parameters during the first discharge of alcaline cells. Mechanisms involved in the electrochemical insertion and deinsertion of H(+) are discussed.

  20. High-resolution measurements of dissolved organic carbon in the Arctic Ocean by in situ fiber-optic spectrometry

    NASA Astrophysics Data System (ADS)

    Guay, Christopher K.; Klinkhammer, Gary P.; Falkner, Kelly Kenison; Benner, Ronald; Coble, Paula G.; Whitledge, Terry E.; Black, Brenda; Bussell, F. Joseph; Wagner, Tim A.

    Here we report results from an extensive survey of dissolved organic carbon (DOC) in the Arctic Ocean, which was achieved by means of a high-resolution, in situ UV fluorometer deployed on a nuclear submarine. Based on a strong linear correlation observed between fluorescence (320 nm excitation, 420 nm emission) and organic carbon concentrations determined directly by high-temperature combustion, a continuous record of DOC was produced at a keel depth of 58 m along a 2900-km transect north of the Beaufort, Chukchi, East Siberian and Laptev seas. The DOC record, combined with other physical and chemical measurements, identifies areas where river waters cross the shelves and enter the circulation of the Arctic interior. Fluvial sources were found to account for 12-56% of the total DOC in parts of the upper Makarov and Amundsen basins.

  1. The potential of gamma-ray spectrometry as supplementary information for mapping central European soils

    NASA Astrophysics Data System (ADS)

    Schuler, U.; Bock, M.; Baritz, R.; Willer, J.; Pickert, E.; Kardel, K.; Herrmann, L.

    2012-04-01

    Permanently updated soil maps are needed inter alia for the prediction of landslide hazards, flooding and drought effects, land degradation monitoring, and precision farming. Since comprehensive and intensive field mapping is not affordable, alternative mapping approaches are required. A promising tool, with quite unrecognised potential for modern soil science is gamma-ray spectrometry. As the radioelements potassium, thorium and uranium respond differently to soil forming processes, it should be possible to infer from their concentration on weathering status, and after calibration on soil properties and types. This paper aims to investigate the potential of airborne gamma spectrometry for mapping of central European soils and soil properties. The study was conducted for a test site in Southern Saxony, Germany, 140*85 km wide, representing diverse soil landscapes. Seven different petrographic training and validation areas were chosen each. To assess the potential of gamma-ray spectrometry as additional data layer, predictions were carried out (i) with and (ii) without radiometric data. The outputs were compared with independent soil information of the validation areas. Both prediction runs used the following predictors: elevation, slope, curvature, planform curvature, profile curvature, terrain ruggedness index, relative altitude, vertical distance above drainage network, wetness index, and convergence index. As additional predictor parent material derived from a reclassification of the official geological map (1:1M scale) was used. As radiometric properties potassium, thorium and uranium were used. The radiometric raster datasets were generated by universal kriging using relative altitude as covariate. Training and validation datasets were selected from a comprehensive dataset representing more than 14.000 point data. Point data include soil types and substrates, and for more than 800 sites soil profiles with analysed texture, pH, exchangeable cations, nutrients, and efficient cation exchange capacity. The study shows that gamma spectrometry is suitable to enhance the prediction of soil types and properties such as texture significantly.

  2. Correction for radon distribution in solid/liquid and air phases in gamma-ray spectrometry.

    PubMed

    Carconi, P; Cardellini, F; Cozzella, M L; De Felice, P; Fazio, A

    2012-09-01

    The effect of radon diffusion and distribution between a (226)Ra matrix and the top air gap inside sample containers for gamma-ray spectrometry was studied. Containers filled at almost 100% or just 70% of total capacity yielded correction factors of about 7% and 20% respectively. Applying these correction factors allowed activity values calculated from (226)Ra or radon decay products to agree within 2%. PMID:22476014

  3. Determination of impurities in (124)I samples by high resolution gamma spectrometry.

    PubMed

    de Almeida, M C M; da Silva, R L; Delgado, J U; Poledna, R; de Araújo, M T F; Laranjeira, A S; de Veras, E; Braghirolli, A M S; Dos Santos, G R; Lopes, R T

    2016-03-01

    (124)I is a radionuclide used in the diagnosis of tumors. The National Health Agency requires identification and activity measurement of impurities. Using gamma spectrometry with an efficiency calibrated high-purity germanium detector, impurities (125)I and (126)I in an (1)(24)I production sample were identified. Activity ratios of (125)I and (126)I to (124)I were approximately 0.5% and 98%, respectively. PMID:26653211

  4. Cadium-Zinc-Telluride (CZT) Gamma Ray Spectrometry

    SciTech Connect

    William Quam

    2001-09-01

    This report describes CZT crystals and their use in large arrays for generation of gamma ray spectra. Laboratory spectra will be shown together with spectra accumulated by various battery powered portable instruments (see Appendix A). One of these portable instruments was specifically constructed to minimize power consumption and yet provide reasonable isotope identification capability. Detailed data will be presented covering gamma energy resolution, gamma peak shapes, system background, and detector efficiency. Nearly all data were taken with very small crystals of CZT; cubes 5 mm on a side. A few spectra will be presented from cylindrical crystals of about the same size (see Appendix A). The small crystal size leads to low counting rates and extended counting times for reliable isotope identification. We have addressed this problem by using arrays of CZT crystals, initially two crystals and, at present, arrays of eight crystals. Data will be shown relating spectral parameters for these two arrays. System MDA is one way of combining resolution, efficiency, and background that will enable direct comparison of various detector types for individual isotope identification. We have calculated the MDA for an early dual crystal array and the current eight crystal array. Data derived from each array will be presented. In addition, it is possible to extrapolate the MDA methodology to much larger arrays. A 32-crystal array is under construction and extrapolations to 256 and 1024 crystals are considered possible. Estimated MDA values for these larger arrays are also presented. Several 8-crystal arrays have been constructed and versions have been incorporated into portable instruments. Descriptions of these small instruments are given covering physical size, weight, and general configuration. These instruments have been tested for shock and temperature effects and data will be presented on the results of these tests. The MDA concept will also allow extrapolation to large source to detector distances. The usual laboratory measurements are done with small sources at 20 to 50 cm ranges. Practical ranges for aerial work will be 50 to 100 meters or greater. These distances will require correction for air attenuation for most of the low energy isotopes. The approximations used in the present note for aerial measurements involve small diameter sources (diameter approximately equal to the altitude), a 1 kt pass, and a planar array with no aircraft attenuation material in the field of view. The array will have a collimator to limit the side-looking sensitivity to enable a more accurate extrapolation from the laboratory data. Large arrays will have significant physical size and weight compared to the small hand-held instruments thus far constructed. We estimate these parameters and extrapolate the power consumption to provide a realistic estimate of a suitable airborne system. In all cases these larger systems are lighter and physically more compact than the usual NaI or high purity Germanium (HPGe) systems used in aerial work. Thus deployment should be simple. The power consumption is much less as well.

  5. NMIS With Gamma Spectrometry for Attributes of Pu and HEU, Explosives and Chemical Agents

    SciTech Connect

    Mihalczo, J. T.; Mattingly, J. K.; Mullens, J. A.; Neal, J. S.

    2002-05-10

    The concept for the system described herein is an active/passive Nuclear Materials Identification System{sup 2} (NMIS) that incorporates gamma ray spectrometry{sup 3}. This incorporation of gamma ray spectrometry would add existing capability into this system. This Multiple Attribute System can determine a wide variety of attributes for Pu and highly enriched uranium (HEU) of which a selected subset could be chosen. This system can be built using commercial off the shelf (COTS) components. NMIS systems are at All-Russian Scientific Research Institute of Experimental Physics (VNIIEF) and Russian Federal Nuclear Center Institute of Technical Physics, (VNIITF) and measurements with Pu have been performed at VNIIEF and analyzed successfully for mass and thickness of Pu. NMIS systems are being used successfully for HEU at the Y-12 National Security Complex. The use of active gamma ray spectrometry for high explosive HE and chemical agent detection is a well known activation analysis technique, and it is incorporated here. This report describes the system, explains the attribute determination methods for fissile materials, discusses technical issues to be resolved, discusses additional development needs, presents a schedule for building from COTS components, and assembly with existing components, and discusses implementation issues such as lack of need for facility modification and low radiation exposure.

  6. Speciation of inorganic arsenic in drinking water by wavelength-dispersive X-ray fluorescence spectrometry after in situ preconcentration with miniature solid-phase extraction disks.

    PubMed

    Hagiwara, Kenta; Inui, Tetsuo; Koike, Yuya; Aizawa, Mamoru; Nakamura, Toshihiro

    2015-03-01

    A rapid and simple method using wavelength-dispersive X-ray fluorescence (WDXRF) spectrometry after in situ solid-phase extraction (SPE) was developed for the speciation and evaluation of the concentration of inorganic arsenic (As) in drinking water. The method involves the simultaneous collection of As(III) and As(V) using 13 mm ? SPE miniature disks. The removal of Pb(2+) from the sample water was first conducted to avoid the overlapping PbL? and AsK? spectra on the XRF spectrum. To this end, a 50 mL aqueous sample (pH 5-9) was passed through an iminodiacetate chelating disk. The filtrate was adjusted to pH 2-3 with HCl, and then ammonium pyrrolidine dithiocarbamate solution was added. The solution was passed through a hydrophilic polytetrafluoroethylene filter placed on a Zr and Ca loaded cation-exchange disk at a flow rate of 12.5 mL min(-1) to separate As(III)-pyrrolidine dithiocarbamate complex and As(V). Each SPE disk was affixed to an acrylic plate using adhesive cellophane tape, and then examined by WDXRF spectrometry. The detection limits of As(III) and As(V) were 0.8 and 0.6 ?g L(-1), respectively. The proposed method was successfully applied to screening for As speciation and concentration evaluation in spring water and well water. PMID:25618730

  7. Testing of regolith of celestial bolides with active neutron gamma-ray spectrometry

    NASA Astrophysics Data System (ADS)

    Vostrukhin, Andrey; Mitrofanov, Igor; Golovin, Dmitry; Litvak, Maxim; Sanin, Anton

    2015-04-01

    Current space instruments for studying planet's surface include gamma ray spectrometers that detect natural radioactive isotopes as well as gamma-rays induced in subsurface by galactic cosmic rays. When measuring from celestial body's surface, statistics and amount of detected elements can be dramatically increased with active methods, where soil exposed to artificial flux of particles. One good example is the Russian Dynamic Albedo of Neutron (DAN) instrument onboard Martian Science Laboratory mission (Curiosity rover) developed in 2005-2011. It is the first active neutron spectrometer flown to another planet as part of a landed mission to investigate subsurface water distribution and which has now successfully operated for more than two years on the Martian surface. Presentation describes a number of space instruments for different landers and rovers being developed in Russian Space Research Institute for studying Moon and Mars, as well as method of active neutron and gamma spectrometry overview.

  8. Reactions of butadiene in zeolite catalysts by in situ variable-temperature solid-state nuclear magnetic resonance spectrometry

    SciTech Connect

    Richardson, B.R.; Lazo, N.D.; Schettler, P.D.; White, J.L.; Haw, J.F. )

    1990-04-11

    The mechanisms by which butadiene oligomerizes in acidic zeolite catalysts leading to deactivation by pore blockage have been elucidated by using in situ {sup 13}C solid-state NMR spectroscopy with magic-angle spinning (MAS). Butadiene is found to oligomerize primarily by the 1,4-addition reaction upon adsorption at its melting point (164 K). Secondary reactions of the oligomers are strongly dependent upon the properties of the zeolite. The initially formed linear product undergoes cyclization reactions to form fused rings in zeolite HY, but isolated rings are formed in the smaller channels of zeolite HZSM-5. Branching reactions and/or 1,2 enchainment result in an appreciable methyl group content in the oligomers formed in zeolite HY. These results provide insight into the mechanisms by which oxide catalysts are deactivated by pore blockage. Neither carbenium ions nor any other reactive intermediates were observed spectroscopically, presumably because such intermediates reacted with either free butadiene or the oligomers so rapidly as to preclude a detectable steady state concentration.

  9. In-situ X-ray diffraction measurements of the [gamma-epsilon] transition boundary of iron in an internally-heated diamond anvil cell

    SciTech Connect

    Komabayashi, T.; Fei, Y.; Meng, Y.; Prakapenka, V.

    2009-05-07

    The phase transition boundary between the {gamma} (face-centered cubic structure) and {epsilon} (hexagonal close-packed structure) iron phases was determined up to 69 GPa by using a newly developed internally-heated diamond anvil cell, combined with in-situ synchrotron X-ray diffraction measurements. The improved experimental configuration provides stable heating with reliable temperature and pressure determination and phase identification. A simultaneous laser- and internal-heating system was also used to produce further higher temperature at higher pressures. The sample pressure at any given temperature was calculated using an established thermal equation of state for {epsilon} iron. The {gamma}-{epsilon} transition boundary was bracketed with the normal and reversal directions and it is linear from 21 to 69 GPa with a dP/dT slope of 0.0394 GPa/K. There is no evidence for the existence of additional iron solid phase other than the {gamma} and {epsilon} phases over the P-T range of this study. We inferred that the {gamma}-{epsilon}-liquid triple point of iron should occur at 88 GPa and 2800 K.

  10. Rapid and Simultaneous In Situ Assessment of Aflatoxins and Stilbenes Using Silica Plate Imprinting Mass Spectrometry Imaging

    PubMed Central

    de Oliveira, Diogo N.; Ferreira, Mônica S.; Catharino, Rodrigo R.

    2014-01-01

    A fast and direct combination of techniques for simultaneous mycotoxin and phytoalexin identification in peanut skin and kernel is described. Silica Plate Imprinting Laser Desorption/Ionization Mass Spectrometry Imaging (SPILDI-MSI) is a powerful technique that exhibits great advantages, such as solvent-free and matrix-free characteristics, as well as no sample preparation or separation steps. It also permits accurate identification of mycotoxins and phytoalexins with unique fingerprint profiles in just a few seconds. Results are expressed as chemical images of the 4 identified types of aflatoxins (B1, B2, G1 and G2) and a stilbenoid (resveratrol). Also, SPILDI-MSI allows the comparison between the spatial distribution of aflatoxins and resveratrol found in kernel and skin. This novel application has proven to be useful for instantaneous qualitative assessment of aflatoxins and stilbenoids both in the peanut skin and kernel and offers precise tracking of fungal contamination in nuts and other foodstuffs. PMID:24595464

  11. Time of Flight Mass Spectrometry Imaging of Samples Fractured In Situ with a Spring-Loaded Trap System

    PubMed Central

    Lanekoff, Ingela; Kurczy, Michael E.; Hill, Rowland; Fletcher, John S.; Vickerman, John C.; Winograd, Nick; Sjövall, Peter; Ewing, Andrew G.

    2010-01-01

    An in situ freeze fracture device featuring a spring-loaded trap system has been designed and characterized for TOF SIMS analysis of single cells. The device employs the sandwich assembly, which is typically used in freeze fracture TOF SIMS experiments to prepare frozen, hydrated cells for high-resolution SIMS imaging. The addition of the spring-loaded trap system to the sandwich assembly offers two advances to this sample preparation method. First, mechanizing the fracture by adding a spring standardizes each fracture by removing the need to manually remove the top of the sandwich assembly with a cryogenically cooled knife. A second advance is brought about because the top of the sandwich is not discarded after the sandwich assembly has been fractured. This results in two imaging surfaces effectively doubling the sample size and providing the unique ability to image both sections of a cell bifurcated by the fracture. Here we report TOF SIMS analysis of freeze fractured rat pheochromocytoma (PC12) cells using a Bi cluster ion source. This work exhibits the ability to obtain single cell chemical images with sub-cellular lateral resolution from cells preserved in an ice matrix. In addition to preserving the cells, the signal from lipid fragment ions rarely identified in single cells are better observed in the freeze-fractured samples for these experiments. Furthermore, using the accepted argument that K+ signal indicates a cell that has been fractured though the cytoplasm, we have also identified different fracture planes of cells over the surface. Coupling a mechanized freeze fracture device to high-resolution cluster SIMS imaging will provide the sensitivity and resolution as well as the number of trials required to carry out biologically relevant SIMS experiments. PMID:20593800

  12. A Case Study Correlating Innovative Gamma Ray Scanning Detection Systems Data to Surface Soil Gamma Spectrometry Results - 13580

    SciTech Connect

    Thompson, Shannon; Rodriguez, Rene; Billock, Paul; Lit, Peter

    2013-07-01

    HydroGeoLogic (HGL), Inc. completed a United States Environmental Protection Agency (USEPA) study to characterize radiological contamination at a site near Canoga Park, California. The characterized area contained 470 acres including the site of a prototype commercial nuclear reactor and other nuclear design, testing, and support operations from the 1950's until 1988 [1]. The site history included radiological releases during operation followed by D and D activities. The characterization was conducted under an accelerated schedule and the results will support the project remediation. The project has a rigorous cleanup to background agenda and does not allow for comparison to risk-based guidelines. To target soil sample locations, multiple lines of evidence were evaluated including a gamma radiation survey, geophysical surveys, historical site assessment, aerial photographs, and former worker interviews. Due to the time since production and decay, the primary gamma emitting radionuclide remaining is cesium-137 (Cs-137). The gamma ray survey covered diverse, rugged terrain using custom designed sodium iodide thallium-activated (NaI(Tl)) scintillation detection systems. The survey goals included attaining 100% ground surface coverage and detecting gamma radiation as sensitively as possible. The effectiveness of innovative gamma ray detection systems was tested by correlating field Cs-137 static count ratios to Cs-137 laboratory gamma spectrometry results. As a case study, the area encompassing the former location of the first nuclear power station in the U. S. was scanned, and second by second global positioning system (GPS)-linked gamma spectral data were evaluated by examining total count rate and nuclide-specific regions of interest. To compensate for Compton scattering from higher energy naturally occurring radionuclides (U-238, Th-232 and their progeny, and K-40), count rate ratios of anthropogenic nuclide-specific regions of interest to the total count rate were calculated. From the scanning data, locations with observed Cs-137 ratios exceeding six standard deviations above the mean ratio were mapped in high resolution [2]. Field teams returned to those locations to collect static count measurements using the same detection systems. Soil surface samples were collected at 30 locations and analyzed for Cs-137. An exponential correlation was identified between Cs-137 concentrations in surface soil and field-scanned Cs-137 ratios. The data indicate field minimum detectable concentration (MDC) of Cs-137 at 0.02 Bq/g (0.5 pCi/g) or lower depending on contaminant distribution in soil. (authors)

  13. Desorption electrospray ionisation mass spectrometry reveals in situ modification of a hindered amine light stabiliser resulting from direct N-OR bond cleavage.

    PubMed

    Paine, Martin R L; Barker, Philip J; Blanksby, Stephen J

    2011-03-01

    Detection and characterisation of structural modifications of a hindered amine light stabiliser (HALS) directly from a polyester-based coil coating have been achieved by desorption electrospray ionisation mass spectrometry (DESI-MS) for the first time. In situ detection is made possible by exposing the coating to an acetone vapour atmosphere prior to analysis. This is a gentle and non-destructive treatment that allows diffusion of analyte to the surface without promoting lateral migration. Using this approach a major structural modification of the HALS TINUVIN123 (bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate) was discovered where one N-ether piperidine moiety (N-OC(8)H(17)) is converted to a secondary piperidine (N-H). With the use of 2-dimensional DESI-MS imaging the modification was observed to arise during high curing temperatures (ca. 260 C) and under simulated physiological conditions (80 C, full solar spectrum). It is proposed that the secondary piperidine derivative is a result of a highly reactive aminyl radical intermediate produced by N-O homolytic bond cleavage. The nature of the bond cleavage is also suggested by ESR spin-trapping experiments employing ?-phenyl-N-tert-butyl nitrone (PBN) in toluene at 80 C. The presence of a secondary piperidine derivative in situ and the implication of N-OR competing with NO-R bond cleavage suggest an alternative pathway for generation of the nitroxyl radical-an essential requirement in anti-oxidant activity that has not previously been described for the N-ether sub-class of HALS. PMID:21152630

  14. In situ emulsification microextraction using a dicationic ionic liquid followed by magnetic assisted physisorption for determination of lead prior to micro-sampling flame atomic absorption spectrometry.

    PubMed

    Shokri, Masood; Beiraghi, Asadollah; Seidi, Shahram

    2015-08-19

    For the first time, a simple and efficient in situ emulsification microextraction method using a dicationic ionic liquid followed by magnetic assisted physisorption was presented to determine trace amounts of lead. In this method, 400 μL of 1.0 mol L(-1) lithium bis (trifluoromethylsulfonyl) imide aqueous solution, Li[NTf2], was added into the sample solution containing 100 μL of 1.0 mol L(-1) 1,3-(propyl-1,3-diyl) bis (3-methylimidazolium) chloride, [pbmim]Cl2, to form a water immiscible ionic liquid, [pbmim][NTf2]2. This new in situ formed dicationic ionic liquid was applied as the acceptor phase to extract the lead-ammonium pyrrolidinedithiocarbamate (Pb-APDC) complexes from the sample solution. Subsequently, 30 mg of Fe3O4 magnetic nanoparticles (MNPs) were added into the sample solution to collect the fine droplets of [pbmim][NTf2]2, physisorptively. Finally, MNPs were eluted by acetonitrile, separated by an external magnetic field and the obtained eluent was subjected to micro-sampling flame atomic absorption spectrometry (FAAS) for further analysis. Comparing with other microextraction methods, no special devices and centrifugation step are required. Parameters influencing the extraction efficiency such as extraction time, pH, concentration of chelating agent, amount of MNPs and coexisting interferences were studied. Under the optimized conditions, this method showed high extraction recovery of 93% with low LOD of 0.7 μg L(-1). Good linearity was obtained in the range of 2.5-150 μg L(-1) with determination coefficient (r(2)) of 0.9921. Relative standard deviation (RSD%) for seven repeated measurements at the concentration of 10 μg L(-1) was 4.1%. Finally, this method was successfully applied for determination of lead in some water and plant samples. PMID:26343434

  15. In-situ monitoring of actinides and rare earth elements by electrothermal hollow cathode discharge spectrometry. Technical progress report

    SciTech Connect

    Lee, S.C.; Edelson, M.C.

    1992-12-01

    This report describes an Electrothermal Hollow Cathode Discharge Spectrometry (ET-HCDS) source being constructed for the analytical determination of actinides and rare earth elements. This work was initiated with the support of the Office of Safeguards and Security; the Buried Waste Integrated Demonstration began funding work in this area in mid-FY1992 and the work is continuing into FY1993 with funds from both sources. Special features of this instrument should permit it to be used for the determination of individual isotopic species, which is important for safeguard`s materials control and accountancy. ET-HCDS can be achieved using compact instrumentation suitable for use in field laboratories. The technique is capable of determining a suite of environmentally-important species, such as the actinides and the heavy metals, in a variety of physical forms (e.g., in solution, as found on air particulates, or in soils). ET-HCDS should be capable of very sensitive analyses and should require very small samples (e.g., microgram). Since ET-HCDS is possible in an air atmosphere (at reduced pressures), it may be useful for the real-time determination of hazardous materials, both radioactive and non radioactive, contained in dusts released during waste retrieval operations; ET-HCDS should also be useful for the rapid and sensitive analysis of metals in soils.

  16. Determination of methylmercury by electrothermal atomic absorption spectrometry using headspace single-drop microextraction with in situ hydride generation

    NASA Astrophysics Data System (ADS)

    Gil, Sandra; Fragueiro, Sandra; Lavilla, Isela; Bendicho, Carlos

    2005-01-01

    A new method is proposed for preconcentration and matrix separation of methylmercury prior to its determination by electrothermal atomic absorption spectrometry (ETAAS). Generation of methylmercury hydride (MeHgH) from a 5-ml solution is carried out in a closed vial and trapped onto an aqueous single drop (3-?l volume) containing Pd(II) or Pt(IV) (50 and 10 mg/l, respectively). The hydrogen evolved in the headspace (HS) after decomposition of sodium tetrahydroborate (III) injected for hydride generation caused the formation of finely dispersed Pd(0) or Pt(0) in the drop, which in turn, were responsible for the sequestration of MeHgH. A preconcentration factor of ca. 40 is achieved with both noble metals used as trapping agents. The limit of detection of methylmercury was 5 and 4 ng/ml (as Hg) with Pd(II) or Pt(IV) as trapping agents, and the precision expressed as relative standard deviation was about 7%. The preconcentration system was fully characterised through optimisation of the following variables: Pd(II) or Pt(IV) concentration in the drop, extraction time, pH of the medium, temperatures of both sample solution and drop, concentration of salt in the sample solution, sodium tetrahydroborate (III) concentration in the drop and stirring rate. The method has been successfully validated against two fish certified reference materials (CRM 464 tuna fish and CRM DORM-2 dogfish muscle) following selective extraction of methylmercury in 2 mol/l HCl medium.

  17. In Situ Analysis of Bacterial Lipopeptide Antibiotics by Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging.

    PubMed

    Debois, Delphine; Ongena, Marc; Cawoy, Hélène; De Pauw, Edwin

    2016-01-01

    Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) is a technique developed in the late 1990s enabling the two-dimensional mapping of a broad variety of biomolecules present at the surface of a sample. In many applications including pharmaceutical studies or biomarker discovery, the distribution of proteins, lipids or drugs, and metabolites may be visualized within tissue sections. More recently, MALDI MSI has become increasingly applied in microbiology where the versatility of the technique is perfectly suited to monitor the metabolic dynamics of bacterial colonies. The work described here is focused on the application of MALDI MSI to map secondary metabolites produced by Bacilli, especially lipopeptides, produced by bacterial cells during their interaction with their environment (bacteria, fungi, plant roots, etc.). This chapter addresses the advantages and challenges that the implementation of MALDI MSI to microbiological samples entails, including detailed protocols on sample preparation (from both microbiologist and mass spectrometrist points of view), matrix deposition, and data acquisition and interpretation. Lipopeptide images recorded from confrontation plates are also presented. PMID:26831708

  18. Measurement of gamma radiation levels in soil samples from Thanjavur using gamma-ray spectrometry and estimation of population exposure.

    PubMed

    Senthilkumar, B; Dhavamani, V; Ramkumar, S; Philominathan, P

    2010-01-01

    This study assesses the level of terrestrial gamma radiation and associated dose rates from the naturally occurring radionuclides (232)Th, (238)U and (40)K in 10 soil samples collected from Thanjavur (Tamil Nadu, India) using gamma-ray spectrometry. The activity profile of radionuclides has clearly showed the existence of low level activity in Thanjavur. The geometric mean activity concentrations of (232)Th, (238)U and (40)K is 42.9+/-9.4 Bq.kg(-1), 14.7+/-1.7 Bq.kg(-1) and 149.5+/-3.1 Bq.kg(-1) respectively are derived from all the soil samples studied. The activity concentration of (232)Th, (238)U and (40)K in soil is due to the presence of metamorphic rocks like shale, hornblende-biotite gneiss and quartzofeldspathic gneiss in these areas. Gamma absorbed dose rates in air outdoors were calculated to be in the range between 32 nGy.h(-1) and 59.1 nGy.h(-1) with an arithmetic mean of 43.3 +/-9 nGy.h(-1). This value is lesser than the population weighted world-averaged of 60 nGy.h(-1). Inhabitants of Thanjavur are subjected to external gamma radiation exposure (effective dose) ranging between 39.2 and 72.6 muSv.y(-1) with an arithmetic mean of 53.1+/-11 muSv.y(-1). The values of the external hazard index determined from the soil radioactivity of the study area are less than the recommended safe levels. PMID:20177570

  19. Apparatus for measuring the stopping power of active materials evaporated in situ and characterized by Auger electron spectrometry and Rutherford backscattering

    SciTech Connect

    Semrad, D.; Bauer, P.; Eder, K.; Obermann, W.

    1986-07-01

    An ultrahigh-vacuum scattering chamber working in the low 10/sup -9/-mbar range is described. It is attached to a standard O-ring sealed beam transport system of an electrostatic accelerator. Twelve targets can be prepared in situ, one by one, by evaporating the material onto backings, which are mounted on tiltable target holders on a wheel. Backscattering spectra are obtained from these targets and the stopping cross section is deduced from their widths. A cooled high-resolution surface barrier detector is used for this purpose. The integral concentrations of light impurities in the target are obtained using Rutherford backscattering (RBS), whereas Auger electron spectrometry (AES) together with a sputtering device is used to determine the depth composition. As a test of the assembly we determined the stopping power of aluminum for protons and deuterons, respectively. The results are compared to published tables based upon fits to experiments. The influence of impurities on the result is discussed for an aluminum target prepared under standard evaporation conditions.

  20. In situ derivatization reaction and determination of ibuprofen in water samples using headspace generation-programmed temperature vaporization-gas chromatography-mass spectrometry.

    PubMed

    Prez Pavn, Jos Luis; Casas Ferreira, Ana Mara; Fernndez Laespada, Mara Esther; Moreno Cordero, Bernardo

    2009-09-25

    The aim of the present work is to propose a method for the determination of ibuprofen, as a typical representative of pharmaceutical compounds, in aqueous samples. To do so, an in situ derivatization reaction in aqueous medium was employed in the vial of a headspace sampler (HS), after which instrumental measurements were made with gas chromatography-mass spectrometry (GC-MS). As the injection system we propose a programmed temperature vaporizer (PTV) where, in solvent vent mode, better results can be obtained than with the conventional split and splitless injection modes. Since the derivatization reaction takes place in the HS vial, after the mixing of reagents and the sealing of the vial, the whole process takes place on-line, with no need for intermediate steps. The simplicity and speed of the method--analysis throughput: 10.5 min--together with the limit of detection obtained (0.23 microg/L), bearing in mind that no preconcentration step or later clean-up step are required, make this a good method for the analysis of ibuprofen in aqueous samples of urban waste water. PMID:19700164

  1. Sublimation extraction coupled with gas chromatography-mass spectrometry: A new technique for future in situ analyses of purines and pyrimidines on Mars

    NASA Astrophysics Data System (ADS)

    Glavin, D. P.; Cleaves, H. J.; Buch, A.; Schubert, M.; Aubrey, A.; Bada, J. L.; Mahaffy, P. R.

    2006-12-01

    We have developed a sublimation technique coupled with chemical derivatization and gas chromatography mass spectrometry (GC-MS) to detect nucleobases and other volatile organic compounds derived from bacteria in Mars analog materials. To demonstrate this technique, a sample of serpentine inoculated with Escherichia coli ( E. coli) cells was heated to 500 C for several seconds under Martian ambient pressure. The sublimate was collected on a cold finger, then derivatized and analyzed by GC-MS. We found that adenine, cytosine, thymine and uracil were the most abundant molecules detected in the sublimed E. coli extract by GC-MS. In addition, nucleobases were also detected in sublimed extracts of a deep-sea sediment sample, seawater, and soil collected from the Atacama Desert in Chile after heating the samples under the same conditions. Our results indicate that nucleobases can be easily isolated directly from natural samples using sublimation and then detected by GC-MS after chemical derivatization. The sublimation-based extraction technique is one approach that should be considered for use by future in situ instruments designed to detect organic compounds relevant to life in the Martian regolith.

  2. Qualitative and quantitative analysis of enantiomers by mass spectrometry: application of a simple chiral chloride probe via rapid in-situ reaction.

    PubMed

    Wang, Lin; Chai, Yunfeng; Ni, Zhangqin; Wang, Lu; Hu, Ruilin; Pan, Yuanjiang; Sun, Cuirong

    2014-01-27

    A tandem mass spectrometry method for high-sensitivity qualitative and quantitative discrimination of chiral amino compounds is conducted. The method is based on a chemical derivation process that uses a simple reagent, L-1-(phenylsulfonyl)pyrrolidine-carbonyl chloride, as the probe. The method is applicable in both organic solutions and biological conditions. Twenty-one pairs of enantiomer containing amino acids, amino alcohols, and amines are used to produce diastereomers using the probe via in situ reaction for 20 s at room temperature. The resulting diastereomers are successfully recognized based on the relative peak intensities of their fragments in positive mode, with the chiral recognition ability values ranging from 0.35 to 3.83. The L/D ratio of Pro spiked at different concentrations (enantiomeric excess) in both acetonitrile and dog plasma is determined by establishing calibration curves. This method achieves a lower limit of quantification of 50 pmol in analyzing amino acids using an extract ion chromatograph. The relative standard deviation for both qualitative and quantitative results is <5%. Thus, the present method is demonstrated as a new and practical technique of rapidly and sensitively determining enantiomers of amino compounds. PMID:24418139

  3. Low Background Gamma-Ray Spectrometry in the 'Laboratoire Souterrain de Modane'

    SciTech Connect

    Hubert, Ph.; Hubert, F.

    2007-03-28

    Most of the underground experiments in physics and many studies in geology, biology or environmental sciences face a common requirement with the necessity of using experimental devices with ultra-low background radioactivity. Many developments involving many different techniques have been used in order to be able to measure extremely low levels of radioactivity in materials. This report will focus on low background gamma-ray spectrometry and will describe the work which has been carried out over the last fifteen years in the 'Laboratoire Souterrain de Modane' (LSM)

  4. Nuclear chemistry of returned lunar samples: Nuclide analysis by gamma-ray spectrometry

    NASA Technical Reports Server (NTRS)

    Okelley, G. D.

    1975-01-01

    Primordial and cosmogenic radionuclide concentrations are determined nondestructively by gamma-ray spectrometry in soil and rock samples from the returned Apollo 17 sample collection from Taurus-Littrow and Descartes. Geochemical evidence in support of field geology speculation concerning layering of the subfloor basalt flows is demonstrated along with a possible correlation of magmatic fractionation of K/U as a function of depth. The pattern of radionuclide concentrations observed in these samples is distinct due to proton bombardment by the intense solar flares of August 4-9, 1972. Such radionuclide determinations are used in determining lunar sample orientation and characterizing solar flare activity.

  5. Comparison of LabSOCS and GESPECOR codes used in gamma-ray spectrometry.

    PubMed

    Done, L; Tugulan, L C; Gurau, D; Dragolici, F; Alexandru, C

    2016-03-01

    Two dedicated software packages -LabSOCS and GESPECOR- for efficiency evaluation in gamma-ray spectrometry, were compared for equivalence. The detection efficiency and the coincidence-summing corrections coefficients were calculated for a specific HPGe detector, for different sample parameters and energies typically encountered in environmental radioactivity measurements. The discrepancy between the results obtained with the two codes were acceptable for most of the applications. Furthermore, the deviations between the values of the standard sources/ reference materials activities from the certificate and the values obtained after Monte Carlo simulation were less than 8% for LabSOCS and 9% for GESPECOR. PMID:26625727

  6. Precipitation correction of airborne gamma-ray spectrometry data using monitoring profiles: methodology and case study

    NASA Astrophysics Data System (ADS)

    Ahl, Andreas; Motschka, Klaus; Slapansky, Peter

    2014-08-01

    Variations of soil moisture content caused by precipitation often complicate the interpretation of airborne gamma-ray spectrometry data. This is particularly the case in repeated surveys designed to monitor the change of near surface abundances of radioactive elements or in large and time-consuming surveys. To counter this precipitation effect we propose a correction method based on repeated survey flights over a monitoring profile. Assuming that the weather and the soil conditions at the monitoring profile are representative for the survey area, the weather dependent effect of soil moisture can be observed and sufficiently corrected.

  7. Evaluation of radiological data of some saturated fatty acids using gamma ray spectrometry

    NASA Astrophysics Data System (ADS)

    Kore, Prashant S.; Pawar, Pravina P.; Palani Selvam, T.

    2016-02-01

    Radiological parameters such as mass attenuation coefficients (μm), total attenuation cross section (σtot), molar extinction coefficient (ε), mass energy absorption coefficient (μen/ρ) and effective electronic cross section (σt, el) of saturated fatty acids, namely butyric acid (C4H8O2), caproic acid (C6H12O2), enanthic acid (C7H14O2), caprylic acid (C8H16O2), pelargonic acid (C9H18O2) and valeric acid (C5H10O2) were measured using NaI(Tl)-based gamma spectrometry. Radioactive sources used in the study are 57Co, 133Ba, 137Cs, 54Mn, 60Co and 22Na. Gamma ray transmission method in a narrow beam good geometry set up was used in the study. The measured data were compared against Win-XCOM-based data. The agreement is within 1%.

  8. Measurement of uranium series radionuclides in rock and groundwater at the Koongarra ore deposit, Australia, by gamma spectrometry

    SciTech Connect

    Yanase, Nobuyuki; Sekine, Keiichi

    1995-12-31

    Gamma spectrometry without any self-absorption correction was developed to measure low energy gamma rays emitted by uranium and actinium series radionuclides in rock samples and groundwater residues collected at the Koongarra ore deposit, Australia. Thin samples were prepared to minimize the self-absorption by uranium in the samples. The present method gave standard deviations of 0.9 to 18% for the measurements of concentrations of uranium and actinium series radionuclides. The concentrations of {sup 238}U, {sup 230}Th and {sup 235}U measured by gamma spectrometry were compared with those by alpha spectrometry that requires a complicated chemical separation procedure. The results obtained by both methods were in fairly good agreement, and it was found that the gamma spectrometry is applicable to rock and groundwater samples having uranium content sup to 8.1% (10{sup 3} B1/g) and 3 Bq/l of {sup 238}U, respectively. The detection limits were calculated to be of the order of 10{sup {minus}2} Bq/g for rock samples and 10{sup {minus}1} Bq/l for groundwater samples. The concentrations of uranium and actinium series radionuclides can be determined precisely in these samples using gamma spectrometry without any self-absorption correction.

  9. Development of a method for in situ measurement of denitrification in aquifers using 15N tracer tests and membrane inlet mass spectrometry

    NASA Astrophysics Data System (ADS)

    Eschenbach, W.; Well, R.; Flessa, H.; Walther, W.; Duijnisveld, W. H. M.

    2009-04-01

    In NO3- contaminated aquifers containing reduced compounds like organic carbon or sulfides, denitrification is an intense process. Its characterization is of interest because NO3- consump-tion improves water quality and N2O production can cause emission of this greenhouse gas to the atmosphere. Spatial distribution of NO3- and N2 produced by denitrification in groundwa-ter (excess N2) reflects the NO3- input as well as cumulative denitrification during aquifer pas-sage. Reaction progress (RP) at a given location, i.e. the relative consumption by denitrifica-tion of the NO3- that had been leached to the aquifers, characterizes the stage of the denitrifi-cation process. RP can be derived from the ratio between accumulated gaseous denitrification products and initial NO3- concentrations. The amount and spatial distribution of reduced com-pounds within denitrifying aquifers is not well known. Recent findings from parallel investi-gations on in situ denitrification and reactive compounds suggests that single-well 15N tracer tests might be suitable to characterize the stock of reduced compounds in aquifers (Konrad 2007). The overall objective of our studies is measure the spatial dynamics of denitrification within two sandy aquifers in northern Germany. This includes measurement of the actually occurring denitrification process. Moreover we want to determine the long-term denitrification potential which is governed by the stock of reactive material. Here we present a new approach for in situ-measurement of denitrification at monitoring wells using a combination of 15N-tracer push-pull experiments with in situ analysis of 15N-labled N2 and N2O using membrane inlet mass spectrometry (MIMS). We will present first results from a laboratory test with aquifer mesocosms using the MIMS method. In this test we supplemented aquifer material of two depths (2 and 7 m below surface) of a drinking water catchment in Northwest Germany with K15NO3 solution. After tracer application we took wa-ter samples at regular intervals with an automated sampling device over 5 days. A small part of the sample was directly conducted in the membrane inlet of our mass spectrometer and the other part was collected in serum bottles which were immediately sealed with rubber septa and stored for later measurement by isotope ratio mass spectrometer (IRMS). Results available up to now showed for both types of measurement a linear increase of deni-trification products (15(N2O+N2)) over time. At the end of our laboratory test we measured up to 270 and 2400 g/L 15(N2O+N2) in the water samples from the supplemented aquifer mate-rial of 3 and 7 m depth respectively. Because of the online measurement with MIMS we were able to see during the experiment if and when the production of the labeled denitrification products started. Later-on this approach will be used in the field. Here, the MIMS-technique will be especially advantageous, because the success of tracer test can be immediately seen during in situ sampling. Results of excess-N2 measurements at the monitoring wells within the two aquifers showed a range of 0 to 30 mg L-1 excess-N2 and a RP between 0 and 100%. References: Konrad, C. (2007): Methoden zur Bestimmung des Umsatzes von Stickstoff, dargestellt fr drei Pleistozne Grundwasserleiter Norddeutschlands, PhD thesis, Dresden Univ. of Techn., Germany, 157 pp.

  10. Real Time in Situ Gamma Radiation Measurements of the Plume Evolution from the Full-Scale Radiological Dispersal Device Field Trials.

    PubMed

    Korpach, Ed; Berg, Rodney; Erhardt, Lorne; Lebel, Luke; Liu, Chuanlei

    2016-05-01

    During the Full-Scale Radiological Dispersal Device Field Trials carried out in Suffield in 2012, several suites of detection and sampling equipment were used to measure and characterize the explosive dispersal of the short half-life radioactive tracer Lanthanum-140 (La). The equipment deployed included networks of in situ real-time radiation monitoring detectors providing measurements of different sensitivities and characteristics. A dense array of lower sensitivity detectors was established near field, ranging from 10 to 450 m from the detonation location. A sparser array of more sensitive detectors was established in the far field (150 m to 3.5 km from the detonation location). Each was used to collect and report the dose rate data from the radioactive plume passage with a sample time resolution of 1 s. The two systems went through independent calibrations and were compared and shown to be consistent with each other. The in situ gamma radiation measurements have allowed the movement and evolution of the plume to be described and to identify deposition rates and non-uniformities in the temporal shape of the plume. This knowledge could be applied for emergency planning guidance for the case of release of radioactive material by a radiological dispersive device. PMID:27023030

  11. An Analysis of Nuclear Fuel Burnup in the AGR 1 TRISO Fuel Experiment Using Gamma Spectrometry, Mass Spectrometry, and Computational Simulation Techniques

    SciTech Connect

    Jason M. Harp; Paul A. Demkowicz; Phillip L. Winston; James W. Sterbentz

    2014-10-01

    AGR 1 was the first in a series of experiments designed to test US TRISO fuel under high temperature gas-cooled reactor irradiation conditions. This experiment was irradiated in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL) and is currently undergoing post irradiation examination (PIE) at INL and Oak Ridge National Laboratory. One component of the AGR 1 PIE is the experimental evaluation of the burnup of the fuel by two separate techniques. Gamma spectrometry was used to non destructively evaluate the burnup of all 72 of the TRISO fuel compacts that comprised the AGR 1 experiment. Two methods for evaluating burnup by gamma spectrometry were developed, one based on the Cs 137 activity and the other based on the ratio of Cs 134 and Cs 137 activities. Burnup values determined from both methods compared well with the values predicted from simulations. The highest measured burnup was 20.1 %FIMA for the direct method and 20.0 %FIMA for the ratio method (compared to 19.56% FIMA from simulations). An advantage of the ratio method is that the burnup of the cylindrical fuel compacts can determined in small (2.5 mm) axial increments and an axial burnup profile can be produced. Destructive chemical analysis by inductively coupled mass spectrometry (ICP MS) was then performed on selected compacts that were representative of the expected range of fuel burnups in the experiment to compare with the burnup values determined by gamma spectrometry. The compacts analyzed by mass spectrometry had a burnup range of 19.3 % FIMA to 10.7 % FIMA. The mass spectrometry evaluation of burnup for the four compacts agreed well with the gamma spectrometry burnup evaluations and the expected burnup from simulation. For all four compacts analyzed by mass spectrometry, the maximum range in the three experimentally determined values and the predicted value was 6% or less. The results confirm the accuracy of the nondestructive burnup evaluation from gamma spectrometry for TRISO fuel compacts across a burnup range of approximately 10 to 20 % FIMA and also validate the approach used in the physics simulation of the AGR 1 experiment.

  12. Radioactivity of a Rock Profile from Rio do Rasto Formation Measured by High Resolution Gamma Spectrometry

    NASA Astrophysics Data System (ADS)

    Bastos, Rodrigo O.; Appoloni, Carlos R.; Pinese, Jos P. P.

    2011-08-01

    Natural occurring radionuclides are present in different concentrations in sedimentary rocks. Generally, their distribution correlates reasonably with their geo-physicochemical behavior during sediment deposition and rock consolidation. This fact permits to study some geological characteristics of the rocks by analyzing the radionuclide distribution in the rocks, as it might reflect the origin of the sediments, the depositional environment, and more recent events such as weathering and erosion. In this work, rocks from an exposed profile of the Rio do Rasto Formation were collected and analyzed in laboratory by high resolution gamma spectrometry for 226Ra, 232Th and 40K determination. It was employed a standard gamma ray spectrometry electronic chain, with a 66% relative efficiency HPGe detector. The efficiency calibration, as well as its validation, was accomplished with eight International Atomic Energy Agency certified samples. The outcrop exposes layers of sandstone and siltstone and, secondarily, claystone, with varying colors (gray, red and green). The rocks were collected along this profile, each of them was dried in the open air during 48 hours, grounded, sieved through 4 mm mesh and sealed in cylindrical recipients. The 226Ra, 232Th and 40K activity concentrations are presented, their distribution and the possible relations among activities are analyzed. The general pattern of radionuclides distribution respects well the hypotheses on geo-physicochemical behavior of radioactive elements.

  13. Total Absorption Gamma-ray Spectrometer (TAGS) Intensity Distributions from INL's Gamma-Ray Spectrometry Center

    DOE Data Explorer

    Greenwood, R. E.

    A 252Cf fission-product source and the INL on-line isotope separator were used to supply isotope-separated fission-product nuclides to a total absorption -ray spectrometer. This spectrometer consisted of a large (25.4-cm diameter x 30.5-cm long) NaI(Tl) detector with a 20.3-cm deep axial well in which is placed a 300-mm2 x 1.0-mm Si detector. The spectra from the NaI(Tl) detector are collected both in the singles mode and in coincidence with the B-events detected in the Si detector. Ideally, this detector would sum all the energy of the B- rays in each cascade following the population of daughter level by B- decay, so that the event could be directly associated with a particular daughter level. However, there are losses of energy from attenuation of the rays before they reach the detector, transmission of rays through the detector, escape of secondary photons from Compton scattering, escape of rays through the detector well, internal conversion, etc., and the measured spectra are thus more complicated than the ideal case and the analysis is more complex. Analysis methods have been developed to simulate all of these processes and thus provide a direct measure of the B- intensity distribution as a function of the excitation energy in the daughter nucleus. These data yield more accurate information on the B- distribution than conventional decay-scheme studies for complex decay schemes with large decay energies, because in the latter there are generally many unobserved and observed but unplaced rays. The TAGS data have been analyzed and published [R. E. Greenwood et al., Nucl Instr. and metho. A390(1997)] for 40 fission product-nuclides to determine the B- intensity distributions. [Copied from the TAGS page at http://www.inl.gov/gammaray/spectrometry/tags.shtml]. Those values are listed on this page for quick reference.

  14. Monte Carlo based method for conversion of in-situ gamma ray spectra obtained with a portable Ge detector to an incident photon flux energy distribution.

    PubMed

    Clouvas, A; Xanthos, S; Antonopoulos-Domis, M; Silva, J

    1998-02-01

    A Monte Carlo based method for the conversion of an in-situ gamma-ray spectrum obtained with a portable Ge detector to photon flux energy distribution is proposed. The spectrum is first stripped of the partial absorption and cosmic-ray events leaving only the events corresponding to the full absorption of a gamma ray. Applying to the resulting spectrum the full absorption efficiency curve of the detector determined by calibrated point sources and Monte Carlo simulations, the photon flux energy distribution is deduced. The events corresponding to partial absorption in the detector are determined by Monte Carlo simulations for different incident photon energies and angles using the CERN's GEANT library. Using the detector's characteristics given by the manufacturer as input it is impossible to reproduce experimental spectra obtained with point sources. A transition zone of increasing charge collection efficiency has to be introduced in the simulation geometry, after the inactive Ge layer, in order to obtain good agreement between the simulated and experimental spectra. The functional form of the charge collection efficiency is deduced from a diffusion model. PMID:9450590

  15. Report of the Department of Energy, Office of Environmental Management, Gamma Spectrometry Data Validation Program

    SciTech Connect

    Decker, K.; Sanderson, C.G.; Greenlaw, P.

    1996-11-01

    This report represents the results of analyses received on or before August 15, 1996 for the first annual Gamma Spectrometry Data Validation Program (May 1996) designed to assess the capability of DOE laboratories and DOE contractors in performing routine gamma spectra analyses. Data reduction of gamma spectra are normally performed with computer codes supplied by commercial manufacturers or are developed in house. Earlier evaluations of commercial codes gave spurious results for complex spectrum. A calibration spectrum, a background spectrum and three sample spectra of increasing complexity were included for each format. The calibration spectrum contained nuclides covering the energy range from 59.5 keV to 1836 keV. The first two samples contained fallout nuclides with halflives of over 30 days. Naturally occurring nuclides were also present. The third sample contained both short and long lived fission product nuclides. The participants were asked to report values and uncertainties as Becquerel per sample with no decay correction. Sixteen software packages were evaluated. In general, the results do not appear to be dependent on the software used. Based on the control limits established for the Program for the three sample spectra, 62%, 63% and 53%, respectively, of the reported results were evaluated as acceptable.

  16. The 124Sb activity standardization by gamma spectrometry for medical applications

    NASA Astrophysics Data System (ADS)

    de Almeida, M. C. M.; Iwahara, A.; Delgado, J. U.; Poledna, R.; da Silva, R. L.

    2010-07-01

    This work describes a metrological activity determination of 124Sb, which can be used as radiotracer, applying gamma spectrometry methods with hyper pure germanium detector and efficiency curves. This isotope with good activity and high radionuclidic purity is employed in the form of meglumine antimoniate (Glucantime) or sodium stibogluconate (Pentostam) to treat leishmaniasis. 124Sb is also applied in animal organ distribution studies to solve some questions in pharmacology. 124Sb decays by β-emission and it produces several photons (X and gamma rays) with energy varying from 27 to 2700 keV. Efficiency curves to measure point 124Sb solid sources were obtained from a 166mHo standard that is a multi-gamma reference source. These curves depend on radiation energy, sample geometry, photon attenuation, dead time and sample-detector position. Results for activity determination of 124Sb samples using efficiency curves and a high purity coaxial germanium detector were consistent in different counting geometries. Also uncertainties of about 2% ( k=2) were obtained.

  17. Differentiation of three pairs of Boc-beta,gamma- and gamma,beta-hybrid peptides by electrospray ionization tandem mass spectrometry.

    PubMed

    Ramesh, V; Srinivas, R; Sharma, G V M; Jayaprakash, P; Kunwar, A C

    2008-09-01

    A new series of Boc-N-beta(3), gamma(4)-/gamma(4), beta(3)-isomeric hybrid peptides (containing repeats of beta(3)-Caa and gamma(4)-Caa's, Caa = C-linked carbo beta(3)-/gamma(4)-amino acids derived from D-xylose) have been differentiated by both positive and negative ion electrospray ionization (ESI) ion-trap and high resolution quadrupole time-of-flight/tandem mass spectrometry (Q-TOF MS/MS). MS(n) of protonated isomeric peptides and [M+H-Boc+H](+) produce characteristic fragmentation involving the peptide backbone, the Boc-group, and the side chain. The positional isomers are differentiated from one another by the presence of y(n)(+), b(n)(+), and other fragment ions of different m/z values. It is observed that the peptides with beta-Caa at the N-terminus produce extensive fragmentation, whereas gamma-Caa gave rise to much less fragmentation. Peptides with gamma-Caa at the N-terminus lose NH(3), whereas this process is absent for the carbopeptides with beta-Caa at the N-terminus. Two pairs of dipeptide diastereomers are clearly differentiated by the collision-induced dissociation (CID) of their protonated molecules. The loss of 2-methylprop-1-ene is more pronounced for Boc-NH-(R)-beta-Caa-(R)-gamma-Caa-OCH(3) (6) and Boc-NH-(R)-gamma-Caa-(R)-beta-Caa-OCH(3) (12), whereas it is insignificant or totally absent for its protonated diastereomeric pair Boc-NH-(S)-beta-Caa-(S)-gamma-Caa-OCH(3) (1) and Boc-NH-(S)-gamma-Caa-(S)-beta-Caa-OCH(3) (7). Further, ESI negative ion tandem mass spectrometry has also been found to be useful for differentiating these isomeric peptide acids. PMID:18320536

  18. Analysis of spectra from portable handheld gamma-ray spectrometry for terrain comparative assessment.

    PubMed

    Dias, Flávio; Lima, Marco; Sanjurjo-Sánchez, Jorge; Alves, Carlos

    2016-04-01

    Geological characteristics can have impacts on societal development by, e.g., geotechnical issues and radiological hazard levels. Due to urban sprawl, there is an increasing need for detailed geological assessment. In this work are analysed data from portable handheld gamma-ray spectra (K, eU and eTh) obtained in granitic and Silurian metaclastic outcrops as well as in an profile, roughly N-S, on soil covered terrains transecting a mapped contact between these rock types (the profile's northern extremity is at locations mapped as granite). Estimations from gamma-ray spectra were studied by univariate and multivariate analyses. K, eU and eTh values were higher on granite in relation to Silurian metaclastic rocks. The northern extremity of the profile showed clearly higher contents of eTh and this contrast was supported by univariate statistical tools (normality plot and Wilk-Shapiro test; boxplots). A ternary plot with the contribution of the elements to gamma-ray absorbed dose showed the separation of granite from Silurian metaclastic rocks with the former being nearer the eTh vertex. The points in the northern extremity of the profile are nearer the eTh vertex than the other points on the profile. These visual suggestions were supported by hierarchical cluster analysis, which was able to differentiate between granite and metaclastic outcrops and separate portions of the profile located on different terrains. Portable gamma-ray spectrometry showed, hence, the potential to distinguish granite and metaclastic terrains at a scale useful for engineering works. These results can also be useful for a first comparative zoning of radiological hazards (which are higher for granite). PMID:26867098

  19. First Year PIDDP Report on gamma-ray and x-ray spectroscopy: X-ray remote sensing and in situ spectroscopy for planetary exploration missions and gamma-ray remote sensing and in situ spectroscopy for planetary exploration missions

    NASA Technical Reports Server (NTRS)

    Mahdavi, M.; Giboni, K. L.; Vajda, S.; Schweitzer, J. S.; Truax, J. A.

    1994-01-01

    Detectors that will be used for planetary missions must have their responses calibrated in a reproducible manner. In addition, it is important to characterize a detector system at uneven portions of its life cycle, for example after exposure to different amounts of radiation. A calibration and response characterization facility has been constructed at Schlumberger-Doll Research for all types of gamma- and x-ray detectors that may be used for planetary measurement. This facility is currently being tested. Initial use is expected for the MARS 94 detectors. The facility will then also be available for calibrating other detectors as well as arrays of detectors such as the NEAR detector with its central Nal(TI) crystal surrounded with a large BGO crystal. Cadmium telluride detectors are investigated for applications in space explorations. These detectors show an energy resolution of 5 keV for the 122 keV 57Co line. Earlier reported polarization effects are not observed. The detectors can be used at temperatures up to 100 C, although with reduced energy resolution. The thickness of standard detectors is limited to 2 mm. These detectors become fully efficient at bias voltages above 200 V. Initial results for a 1 cm thick detector show that the quality of the material is inferior to the thinner standard detectors and hole trapping affects the pulse height. A detailed characterization of the detector is in progress. Prototypes of photomultipliers based on a Channel Electron Multiplier (CEM) are being built to study their performance. Such photomultipliers promise better timing characteristics and a higher dynamic range while being more compact and of lower in weight.

  20. Summary of gamma spectrometry on local air samples from 1985--1995

    SciTech Connect

    Winn, W.G.

    1997-04-02

    This report summarizes the 1985--1995 results of low-level HPGe gamma spectrometry analysis of high-volume air samples collected at the Aiken Airport, which is about 25 miles north of SRS. The author began analyzing these samples with new calibrations using the newly developed GRABGAM code in 1985. The air sample collections were terminated in 1995, as the facilities at the Aiken Airport were no longer available. Air sample measurements prior to 1985 were conducted with a different analysis system (and by others prior to 1984), and the data were not readily available. The report serves to closeout this phase of local NTS air sample studies, while documenting the capabilities and accomplishments. Hopefully, the information will guide other applications for this technology, both locally and elsewhere.

  1. Fast-ion energy resolution by one-step reaction gamma-ray spectrometry

    NASA Astrophysics Data System (ADS)

    Salewski, M.; Nocente, M.; Gorini, G.; Jacobsen, A. S.; Kiptily, V. G.; Korsholm, S. B.; Leipold, F.; Madsen, J.; Moseev, D.; Nielsen, S. K.; Rasmussen, J.; Stejner, M.; Tardocchi, M.; Contributors, JET

    2016-04-01

    The spectral broadening of γ-rays from fusion plasmas can be measured in high-resolution gamma-ray spectrometry (GRS). We derive weight functions that determine the observable velocity space and quantify the velocity-space sensitivity of one-step reaction high-resolution GRS measurements in magnetized fusion plasmas. The weight functions suggest that GRS resolves the energies of fast ions directly without the need for tomographic inversion for selected one-step reactions at moderate plasma temperatures. The D(p,γ)3He reaction allows the best direct fast-ion energy resolution. We illustrate our general formalism using reactions with and without intrinsic broadening of the γ-rays for the GRS diagnostic at JET.

  2. A review of the nationwide proficiency test on natural radioactivity measurements by gamma spectrometry.

    PubMed

    Şahin, N K; Yeltepe, E; Yücel, Ü

    2016-03-01

    This study is the review of the first proficiency test on radioactivity measurement organized in Turkey by Sarayköy Nuclear Research and Training Center (SANAEM) of Turkish Atomic Energy Authority (TAEK) in 2013. The objective of the test was to determine (226)Ra, (232)Th and (40)K activity concentrations in natural soil samples using gamma-ray spectrometry. The bulk material consisting of uranium- and thorium-rich soil and sand was milled, mixed thoroughly and sieved. Homogeneity of the final mix was tested with 6 randomly taken samples. 16 proficiency test samples were distributed to 16 participating laboratories. 12 laboratories reported results. The results were evaluated on the accuracy and precision criteria adopted by the IAEA Proficiency Testing Group. The percentage of acceptable scores was 49%. Some recommendations have been provided to the laboratories to improve the quality of their results. It is planned to extend these proficiency tests periodically for various radionuclides in various matrices. PMID:26750585

  3. In situ gamma ray survey for geological mapping of Kmetasomatized metavolcanics at Bükkszentkereszt, Bükk Mts, Hungary

    NASA Astrophysics Data System (ADS)

    Németh, Norbert; Pethõ, Gábor; Zajzon, Norbert

    2015-09-01

    The Middle-Upper Triassic Bagolyhegy Metarhyolite Formation of the Bükk Mts. (Hungary) hosts silicified bodies with high potassic feldspar content formed by Kmetasomatism. The rocks underwent a multistage deformation history including syn- and postmetamorphic folding and faulting. As the outcrop area is covered by soil and debris with some exposed silicified cliffs only, and potassium content is a characteristic feature of the metasomatized rocks, geological mapping was supported by a spectral gamma ray survey with a scintillation detector of NaI(Tl) crystal. A thunderstorm felling the beech forest made the soil horizon B also accessible in several pits, providing the opportunity to make measurements on the weathered debris instead of the topsoil (horizon A). Measurements in different arrangements were designed to test the effects of measuring time, measuring geometry and soil horizon. Our results show that concentration values obtained on the debris with a 2 min measuring time can be compared with those measured on exposed rock surfaces, producing a more reliable geological map than measurements on the topsoil with randomly variable K depletion. Pit geometry effects can be eliminated by the K/(eU+eTh) ratio. This results in a more realistic K distribution map if neither U nor Th enrichments are present. The survey successfully delineated the unexposed outcrop of K-enriched rocks on the survey area.

  4. Application of gamma-ray spectrometry in a NORM industry for its radiometrical characterization

    NASA Astrophysics Data System (ADS)

    Mantero, J.; Gázquez, M. J.; Hurtado, S.; Bolívar, J. P.; García-Tenorio, R.

    2015-11-01

    Industrial activities involving Naturally Occurring Radioactive Materials (NORM) are found among the most important industrial sectors worldwide as oil/gas facilities, metal production, phosphate Industry, zircon treatment, etc. being really significant the radioactive characterization of the materials involved in their production processes in order to assess the potential radiological risk for workers or natural environment. High resolution gamma spectrometry is a versatile non-destructive radiometric technique that makes simultaneous determination of several radionuclides possible with little sample preparation. However NORM samples cover a wide variety of densities and composition, as opposed to the standards used in gamma efficiency calibration, which are either water-based solutions or standard/reference sources of similar composition. For that reason self-absorption correction effects (especially in the low energy range) must be considered individually in every sample. In this work an experimental and a semi-empirical methodology of self-absorption correction were applied to NORM samples, and the obtained results compared critically, in order to establish the best practice in relation to the circumstances of an individual laboratory. This methodology was applied in samples coming from a TiO2 factory (NORM industry) located in the south-west of Spain where activity concentration of several radionuclides from the Uranium and Thorium series through the production process was measured. These results will be shown in this work.

  5. Efficiency transfer using the GEANT4 code of CERN for HPGe gamma spectrometry.

    PubMed

    Chagren, S; Tekaya, M Ben; Reguigui, N; Gharbi, F

    2016-01-01

    In this work we apply the GEANT4 code of CERN to calculate the peak efficiency in High Pure Germanium (HPGe) gamma spectrometry using three different procedures. The first is a direct calculation. The second corresponds to the usual case of efficiency transfer between two different configurations at constant emission energy assuming a reference point detection configuration and the third, a new procedure, consists on the transfer of the peak efficiency between two detection configurations emitting the gamma ray in different energies assuming a "virtual" reference point detection configuration. No pre-optimization of the detector geometrical characteristics was performed before the transfer to test the ability of the efficiency transfer to reduce the effect of the ignorance on their real magnitude on the quality of the transferred efficiency. The obtained and measured efficiencies were found in good agreement for the two investigated methods of efficiency transfer. The obtained agreement proves that Monte Carlo method and especially the GEANT4 code constitute an efficient tool to obtain accurate detection efficiency values. The second investigated efficiency transfer procedure is useful to calibrate the HPGe gamma detector for any emission energy value for a voluminous source using one point source detection efficiency emitting in a different energy as a reference efficiency. The calculations preformed in this work were applied to the measurement exercise of the EUROMET428 project. A measurement exercise where an evaluation of the full energy peak efficiencies in the energy range 60-2000keV for a typical coaxial p-type HpGe detector and several types of source configuration: point sources located at various distances from the detector and a cylindrical box containing three matrices was performed. PMID:26623928

  6. Development and application of compact denuder sampling techniques with in situ derivatization followed by gas chromatography-mass spectrometry for halogen speciation in volcanic plumes

    NASA Astrophysics Data System (ADS)

    Rüdiger, Julian; Bobrowski, Nicole; Hoffmann, Thorsten

    2015-04-01

    Volcanoes are a large source for several reactive atmospheric trace gases including sulphur and halogen containing species. The detailed knowledge of volcanic plume chemistry can give insights into subsurface processes and can be considered as a useful geochemical tool for monitoring of volcanic activity, especially halogen to sulphur ratios (e.g. Bobrowski and Giuffrida, 2012; Donovan et al., 2014). The reactive bromine species bromine monoxide (BrO) is of particular interest, because BrO as well as SO2 are readily measurable by UV spectrometers at a safe distance. Furthermore it is formed in the plume by a multiphase reaction mechanism under depletion of ozone in the plume. The abundance of BrO changes as a function of the reaction time and therefore distance from the vent as well as the spatial position in the plume. Due to the lack of analytical approaches for the accurate speciation of certain halogens (HBr, Br2, Br, BrCl, HOBr etc.) there are still uncertainties about the magnitude of volcanic halogen emissions and in particular their specificationtheir species and therefore also in the understanding of the bromine chemistry in volcanic plumes (Bobrowski et al., 2007). In this study, the first application of a 1,3,5-trimethoxybenzene (1,3,5-TMB)-coated gas diffusion denuder (Huang and Hoffmann, 2008) on volcanic gases proved to be suitable to collect selectively gaseous bromine species with oxidation states of +1 or 0 (Br2 and BrO(H)), while being ignorant to HBr (OS -1). The reaction of 1,3,5-TMB with bromine gives 1-bromo-2,4,6-trimethoxybenzene (1-bromo-2,4,6-TMB) - other halogens give corresponding products. The diffusion denuder technique allows sampling of gaseous compounds exclusively without collecting particulate matter. Choosing a flow rate of 500 mL-min-1 and a denuder length of 0.5 m a nearly quantitative collection efficiency was achieved. Solvent elution of the derivatized analytes and subsequent analysis with gas chromatography-mass spectrometry gives a limit of detection below 1 ng of bromine. The method was applied on volcanic gas plumes at Mt. Etna and Mt. Stromboli in Italy in July 2014 and on fumarolic gas emissions at Mt. Lastarria in Chile in November 2014. The results show significant amounts of the concerning bromine species (lower ppb range). Comprehensive data evaluation and comparison with results of impinger extraction with NaOH solution as well as chamber experiments are still in progress. References Bobrowski, N. and G. Giuffrida: Bromine monoxide / sulphur dioxide ratios in relation to volcanological observations at Mt. Etna 2006-2009. Solid Earth, 3, 433-445, 2012 Bobrowski, N., R. von Glasow, A. Aiuppa, S. Inguaggiato, I. Louban, O. W. Ibrahim and U. Platt: Reactive halogen chemistry in volcanic plumes. J. Geophys. Res., 112, 2007 Donovan A., V. Tsanev, C. Oppenheimer and M. Edmonds: Reactive halogens (BrO and OClO) detected in the plume of Soufrière Hills Volcano during an eruption hiatus. Geochem. Geophys. Geosyst., 15, 3346-3363, 2014 Huang, R.-J. and T. Hoffmann: A denuder-impinger system with in situ derivatization followed by gas chromatography-mass spectrometry for the determination of gaseous iodine-containing halogen species. Journal of Chromatography A, 1210, 135-141, 2008

  7. On-line interrogation of pebble bed reactor fuel using passive gamma-ray spectrometry

    NASA Astrophysics Data System (ADS)

    Chen, Jianwei

    The Pebble Bed Reactor (PBR) is a helium-cooled, graphite-moderated high temperature nuclear power reactor. In addition to its inherently safe design, a unique feature of this reactor is its multipass fuel cycle in which graphite fuel pebbles (of varying enrichment) are randomly loaded and continuously circulated through the core until they reach their prescribed end-of-life burnup limit (80,000--100,000 MWD/MTU). Unlike the situation with conventional light water reactors (LWRs), depending solely on computational methods to perform in-core fuel management will be highly inaccurate. As a result, an on-line measurement approach becomes the only accurate method to assess whether a particular pebble has reached its end-of-life burnup limit. In this work, an investigation was performed to assess the feasibility of passive gamma-ray spectrometry assay as an approach for on-line interrogation of PBR fuel for the simultaneous determination of burnup and enrichment on a pebble-by-pebble basis. Due to the unavailability of irradiated or fresh pebbles, Monte Carlo simulations were used to study the gamma-ray spectra of the PBR fuel at various levels of burnup. A pebble depletion calculation was performed using the ORIGEN code, which yielded the gamma-ray source term that was introduced into the input of an MCNP simulation. The MCNP simulation assumed the use of a high-purity coaxial germanium detector. Due to the lack of one-group high temperature reactor cross sections for ORIGEN, a heterogeneous MCNP model was developed to describe a typical PBR core. Subsequently, the code MONTEBURNS was used to couple the MCNP model and ORIGEN. This approach allowed the development of the burnup-dependent, one-group spectral-averaged PBR cross sections to be used in the ORIGEN pebble depletion calculation. Based on the above studies, a relative approach for performing the measurements was established. The approach is based on using the relative activities of Np-239/I-132 in combination with the relative activities of Cs-134/Co-60 (Co-60 is introduced as a dopant) to yield the burnup and enrichment for each pebble. Furthermore, a direct consequence of the relative approach is the ability to apply a self-calibration scheme using the multiple gamma lines of Ba-La-140 to establish the relative efficiency curve of the HPGe detector. An assessment of the expected uncertainty components in this approach showed that a maximum uncertainty of less than 5% should be feasible. To confirm the above findings, gamma-ray scans were performed on irradiated PULSTAR reactor fuel assemblies at North Carolina Sate University. The measurements used a 40% efficient n-type coaxial HPGe detector connected to an ORTEC DSPEC plus digital Gamma-Ray Spectrometer, and a data acquisition computer. The obtained results showed consistency with the predictions of the simulations including the observation of the I-132, Cs-134, Np-239 uncontaminated gamma lines. In addition, the Ba-La-140 lines were clearly observed confirming the ability to perform relative calibration of the spectrometer.

  8. Recent achievements for In-situ measurement: applications to an actual decommissioning project

    SciTech Connect

    Lamadie, F.; Girones, P.; Le Goaller, C.; Mahe, C.; Kohler, J.Y.; Risser, M.A.

    2007-07-01

    Decommissioning a nuclear facility implies a policy of limiting the waste volume and its chemical - and especially radiological - toxicity. It is therefore important to determine the activity level contained in each component that will be dismantled. A variety of methods and analysis techniques are used for this purpose, ranging from simple dose rate measurements to {gamma} spectrometry and {gamma} imaging. The results of several measurement campaigns in a reactor currently in operation but for which decommissioning studies have now been undertaken are discussed. The measurements provide additional radiological data for the waste inventory, which is one of the first issues to be examined. This discussion focuses on the methods used ({gamma} imaging, in situ {gamma} spectrometry, etc.), the results obtained, and their implications for the project, as well as the technological and methodological innovations implemented during these campaigns. (authors)

  9. Application of low-background gamma-ray spectrometry to monitor radioactivity in the environment and food.

    PubMed

    Khan, A J; Semkow, T M; Beach, S E; Haines, D K; Bradt, C J; Bari, A; Syed, U-F; Torres, M; Marrantino, J; Kitto, M E; Menia, T; Fielman, E

    2014-08-01

    The results are described of an upgrade of the low-background gamma-ray spectrometry laboratory at New York State Department of Health by acquiring sensitivity to low-energy gamma rays. Tuning of the spectrometer and its low-energy response characteristics are described. The spectrometer has been applied to monitor the environment by measuring aerosols and water in New York State contaminated by the 2011 Fukushima accident plume. In addition, the spectrometer has been used to monitor radioactivity in food by performing a study of cesium in Florida milk. PMID:24836905

  10. In-situ gamma-ray survey of rare-earth tailings dams - A case study in Baotou and Bayan Obo Districts, China.

    PubMed

    Li, Baochuan; Wang, Nanping; Wan, Jianhua; Xiong, Shengqing; Liu, Hongtao; Li, Shijun; Zhao, Rong

    2016-01-01

    An in-situ gamma-ray spectrometer survey with a scintillation detector of NaI(Tl) (Φ75 mm × 75 mm) was carried out in the Baotou and Bayan Obo Districts in order to estimate the levels of natural radionuclides near rare-earth (RE) tailings dams. In the RE tailings dam of Baotou, the mean concentrations of (238)U and (232)Th were 3.0 ± 1.0 mg/kg (range: 1.9-4.6 mg/kg) and 321 ± 31 mg/kg (range: 294-355 mg/kg), respectively. In the Bayan Obo tailings dam, the mean concentrations of (238)U and (232)Th were 5.7 ± 0.5 mg/kg (range: 5.3-6.1 mg/kg) and 276 ± 0.5 mg/kg (range: 275.5-276.3 mg/kg), respectively. The average (232)Th concentrations in the mining areas of the Bayan Obo Mine and the living areas of the Bayan Obo Town were 18.7 ± 7.5 and 26.2 ± 9.1 mg/kg, respectively. The (232)Th concentration recorded in the tailings dams was much higher than the global average (7.44 mg/kg). Our investigation shows that the (232)Th concentration in the tailings in the Baotou dam was 34.6 times greater than that in the local soil (in Guyang County); the average concentrations of (232)Th in the soil in the Baotou District and Bayan Obo Districts were about 1.35 and 2.82 times greater, respectively, than that in the soil in Guyang County. Based on our results, the highest estimated effective dose due to gamma irradiation was 1.15 mSv per year, estimated from the data observed in the Baotou tailings dams. The results of this preliminary study indicate the potential importance of radioactivity in RE tailings dams and that remedial measures may be required. PMID:26555365

  11. In Situ Production of Gamma Interferon, Interleukin-4, and Tumor Necrosis Factor Alpha mRNA in Human Lung Tuberculous Granulomas

    PubMed Central

    Fenhalls, Gael; Wong, Anthony; Bezuidenhout, Juanita; van Helden, Paul; Bardin, Philip; Lukey, Pauline T.

    2000-01-01

    Human tuberculous granulomas from five adults undergoing surgery for hemoptysis were analyzed by nonradioactive in situ hybridization for tumor necrosis factor alpha (TNF-?), gamma interferon (IFN-?), and interleukin-4 (IL-4) gene expression. All of the patients produced TNF-? mRNA. Three patients stained positive for both IFN-? and IL-4 mRNA; the other two stained positive for IFN-? but not IL-4 mRNA. Heterogeneity between the granulomas was observed in those patients staining positive for both IFN-? and IL-4 mRNA; these patients exhibited granulomas having IFN-? and not IL-4 mRNA as well as granulomas positive for both cytokine mRNAs. There was no evidence of caseation in these granulomas, and the cytokine patterns may represent events in the evolution of the granuloma. However, in those granulomas exhibiting caseous necrosis, very little IFN-? or IL-4 mRNA was observed, implying that progression of the granuloma is accompanied by a down regulation of T-cell responses. TNF-? mRNA expression was highest in patients with both IFN-? and IL-4 mRNA. Populations of CD68 positive macrophage-like cells within the granulomas produce mRNA for TNF-?, IFN-?, and IL-4. This implies that macrophages within the tuberculous granuloma may not be dependent on T-cell cytokines for modulation of their function but may be able to regulate their own activation state and that of the surrounding T cells. These findings have implications on the delivery of immunotherapies to patients with tuberculosis. PMID:10768979

  12. Implementation of gamma-ray spectrometry in two real-time water monitors using NaI(Tl) scintillation detectors.

    PubMed

    Casanovas, R; Morant, J J; Salvad, M

    2013-10-01

    In this study, the implementation of gamma-ray spectrometry in two real-time water monitors using 2 in. 2 in. NaI(Tl) scintillation detectors is described. These monitors collect the water from the river through a pump and it is analyzed in a vessel, which is shielded with Pb. The full calibration of the monitors was performed experimentally, except for the efficiency curve, which was set using validated Monte Carlo simulations with the EGS5 code system. After the calibration, the monitors permitted the identification and quantification of the involved isotopes in a possible radioactive increment and made it possible to discard possible leaks in the nuclear plants. As an example, a radiological increment during rain is used to show the advantages of gamma-ray spectrometry. To study the capabilities of the monitor, the minimum detectable activity concentrations for (131)I, (137)Cs and (40)K are presented for different integration times. PMID:23827508

  13. Assessment of measurement result uncertainty in determination of (210)Pb with the focus on matrix composition effect in gamma-ray spectrometry.

    PubMed

    Iurian, A R; Pitois, A; Kis-Benedek, G; Migliori, A; Padilla-Alvarez, R; Ceccatelli, A

    2016-03-01

    Reference materials were used to assess measurement result uncertainty in determination of (210)Pb by gamma-ray spectrometry, liquid scintillation counting, or indirectly by alpha-particle spectrometry, using its daughter (210)Po in radioactive equilibrium. Combined standard uncertainties of (210)Pb massic activities obtained by liquid scintillation counting are in the range 2-12%, depending on matrices and massic activity values. They are in the range 1-3% for the measurement of its daughter (210)Po using alpha-particle spectrometry. Three approaches (direct computation of counting efficiency and efficiency transfer approaches based on the computation and, respectively, experimental determination of the efficiency transfer factors) were applied for the evaluation of (210)Pb using gamma-ray spectrometry. Combined standard uncertainties of gamma-ray spectrometry results were found in the range 2-17%. The effect of matrix composition on self-attenuation was investigated and a detailed assessment of uncertainty components was performed. PMID:26653212

  14. Assessment of radiological hazards of Lawrencepur sand, Pakistan using gamma spectrometry.

    PubMed

    Qureshi, Aziz Ahmed; Ali, Muhammad; Waheed, Abdul; Manzoor, Shahid; Siddique, Rehan Ul Haq; Ahmed Khan, Hameed

    2013-11-01

    The Lawrencepur sand had remained refrigerated during a long period of glaciations in the study area. Owing to its derivation from the granitic rocks of the Himalayas and its preservation under glacial environment, the sand grains are still fresh and may contain high level of primordial radioactivity. For that reason, radiological hazards of Lawrencepur sand were assessed using a high-purity germanium gamma spectrometry technique. The average activity concentrations of (226)Ra, (232)Th and (40)K were found to be 15.973.05, 27.984.89 and 498.2015.91 Bq kg(-1), respectively. These values are higher than those of the sands of many countries of the world but lower than those of some of the Pakistani, Indian and Egyptian sands. The outdoor and indoor hazard indices and annual effective doses of the Lawrencepur sand are higher than those of some of the sand deposits of European, African and American countries but lower than those of nearby Pakistani and Indian sands. However, the hazard indices and annual effective doses of the Lawrencepur sand are within the safe limits. Overall, the Lawrencepur sand does not pose any radiological health hazard as a building material. PMID:23630384

  15. Detection of /sup 210/Pb in the lungs of smokers by in-vivo gamma spectrometry

    SciTech Connect

    Berger, C.D.; Lane, B.H.

    1982-09-01

    Since mainstream smoke is highly enriched in /sup 210/Pb, alpha radiation from inhaled cigarette smoke particles has been proposed as a cancer-producing agent in cigarette smokers. /sup 210/Po and /sup 210/Pb have been observed in tobacco, cigarette smoke and in the lungs of smokers. Since /sup 210/Pb is highly enriched in mainstream smoke, there have been estimates of yearly excesses of /sup 210/Pb in the lungs of one-pack-a-day smokers of 3 to 10 pCi (0.11 to 0.37 Bq). The ORNL Whole Body Counter was used to verify this estimate by the methodology of high-resolution, in vivo gamma spectrometry. Measurements were made on 113 adult male non-radiation workers who have either smoked at least one pack of cigarettes per day for at least five years, or have never smoked cigarettes. An analysis-of-variance table was generated based on the Pb-ratio for each individual which revealed that there was no statistically significant increase in the amount of /sup 210/Pb in the lungs of smokers over those of non-smokers. Sources of error are also discussed.

  16. Using gamma ray spectrometry for fingerprinting sources of estuarine and coastal sediment in Mukawa coast, Hokkaido, northern Japan

    NASA Astrophysics Data System (ADS)

    Mizugaki, S.; Ohtsuka, J.; Murakami, Y.; Ishiya, T.; Hamamoto, S.

    2010-12-01

    To seek the geological tracers of environmental radionuclide for fingerprinting sources of estuarine and coastal sediment, the gamma ray spectrometry was conducted for the soil and sediment samples collected from subcatchments, rivers, estuaries and coast in Mukawa and Sarugawa river watersheds and Mukawa coast, Hokkaido, northern Japan. Gamma ray spectrometry was conducted to determine the activities of environmental radionuclides associated with each soil and sediment samples using HP Ge well-type detector. Gamma ray spectrometry could determine 15 environmental radionuclides, including U-series, Th-series, cesium-137 and potassium-40. Lead-210 excess was also determined by subtracting the activities of Pb-214 from that of Pb-210. The Kruskal-Wallis H test was conducted to assess the ability of each tracer property to discriminate between surface soil samples from the categories divided by subcatchment, geological era and period, suggesting that more than 11 tracer properties were available. Subsequently, the stepwise discriminant function analysis was conducted to identify which combination of tracer properties provides the best composite fingerprint for differentiating source materials on the basis of subcatchment and geology source groups. This analysis suggested that the composite fingerprints of Pb-212, Ac-228 and K-40 can classify the geology into 6 groups based on rock type. Using these tracer properties, the contribution of rock to estuarine and coastal sediment can be evaluated with the multivariate sediment mixing model.

  17. A NEW METHDOLOGY FOR DETERMINING FISSILE MASS IN INDIVIDUAL ACCOUNTING ITEMS WITH THE USE OF GAMMA-RAY SPECTROMETRY.

    SciTech Connect

    KANE,W.R.; VANIER,P.E.; ZUHOSKI,P.B.; LEMLEY,J.R.

    2000-07-16

    In the safeguards, arms control, and nonproliferation regimes measurements are required which give the quantity of fissile material in an accounting item, e.g., a standard container of plutonium or uranium oxide. Because of the complexity of modeling the absorption of gamma rays in high-Z materials, gamma-ray spectrometry is not customarily used for this purpose. Gamma-ray measurements can be used to determine the fissile mass when two conditions are met: (1) The material is in a standard container, and (2) The material is finely divided, or a solid item with a reproducible shape. The methodology consists of: (A) Measurement of the emitted gamma rays, and (B) Measurement of the transmission through the item of the high-energy gamma rays of Co-60 and Th-228. We have demonstrated that items containing nuclear materials possess a characteristic ''fingerprint'' of gamma rays which depends not only on the nuclear properties, but also on the mass, density, shape, etc.. The material's spectrum confirms its integrity, homogeneity, and volume as well. While there is attenuation of radiation from the interior, the residual radiation confirms the homogeneity of the material throughout the volume. Transmission measurements, where the attenuation depends almost entirely on Compton scattering, determine the material mass. With well-characterized standards, this methodology can provide an accurate measure of the contained fissile material.

  18. Neanderthal skeleton from Tabun: U-series data by gamma-ray spectrometry.

    PubMed

    Schwarcz, H P; Simpson, J J; Stringer, C B

    1998-12-01

    The Neanderthal hominid Tabun C1, found in Israel by Garrod & Bate, was attributed to either layer B or C of their stratigraphic sequence. We have used gamma-ray spectrometry to determine the 230Th/234U and 231Pa/235U ratios of two bones from this skeleton, the mandible and a femur. The ages calculated from these ratios depend on the uranium uptake history of the bones. Assuming a model of early U (EU) uptake the age of the Tabun C1 mandible is 34+/-5 ka. The EU age of the femur is 19+/-2 ka. The femur may have experienced continuous (linear) U uptake which would give an age of 33+/-4 ka, in agreement with the mandible's EU age, but implies marked inhomogeneity in U uptake history at the site. These new age estimates for the skeleton suggest that it was younger than deposits of layer C. This apparent age is less than those of other Neanderthals found in Israel, and distinctly younger than the ages of the Skhul and Qafzeh burials. This suggests that Neanderthals did not necessarily coexist with the earliest modern humans in the region. All of the more complete Neanderthal fossils from Israel are now dated to the cool period of the last glacial cycle, suggesting that Neanderthals may have arrived in this region as a result of the southward expansion of their habitable range. The young age determined for the Tabun skeleton would suggest that Neanderthals survived as late in the Levant as they did in Europe. PMID:9929173

  19. Assessment of the suitability of different random number generators for Monte Carlo simulations in gamma-ray spectrometry.

    PubMed

    Daz, N Cornejo; Gil, A Vergara; Vargas, M Jurado

    2010-03-01

    The Monte Carlo method has become a valuable numerical laboratory framework in which to simulate complex physical systems. It is based on the generation of pseudo-random number sequences by numerical algorithms called random generators. In this work we assessed the suitability of different well-known random number generators for the simulation of gamma-ray spectrometry systems during efficiency calibrations. The assessment was carried out in two stages. The generators considered (Delphi's linear congruential, mersenne twister, XorShift, multiplier with carry, universal virtual array, and non-periodic logistic map based generator) were first evaluated with different statistical empirical tests, including moments, correlations, uniformity, independence of terms and the DIEHARD battery of tests. In a second step, an application-specific test was conducted by implementing the generators in our Monte Carlo program DETEFF and comparing the results obtained with them. The calculations were performed with two different CPUs, for a typical HpGe detector and a water sample in Marinelli geometry, with gamma-rays between 59 and 1800 keV. For the Non-periodic Logistic Map based generator, dependence of the most significant bits was evident. This explains the bias, in excess of 5%, of the efficiency values obtained with this generator. The results of the application-specific assessment and the statistical performance of the other algorithms studied indicate their suitability for the Monte Carlo simulation of gamma-ray spectrometry systems for efficiency calculations. PMID:20018515

  20. A revision factor to the Cutshall self-attenuation correction in (210)Pb gamma-spectrometry measurements.

    PubMed

    Jod?owski, Pawe?

    2016-03-01

    The Cutshall transmission method of determination of self-attenuation correction in (210)Pb measurements by gamma-spectrometry gives the results burdened with errors of up to 10%. The author proposes introducing into the Cutshall correction Cs,Cuts an additional revision factor CCs,Cuts to eliminate errors. The proposed formula of the revision factor describes the CCs,Cuts value depending on the experimentally obtained Cs,Cuts correction. Formula holds true in wide ranges of the measurement geometries and linear attenuation coefficients of both the standard and the sample. PMID:26702546

  1. Multi-scale monitoring of a marine geologic methane source in the Santa Barbara Channel using imaging spectrometry, ARCTAS-CARB in situ sampling and coastal hourly total hydrocarbon measurements

    NASA Astrophysics Data System (ADS)

    Bradley, E. S.; Leifer, I.; Roberts, D.; Dennison, P. E.; Margolis, J.; Moritsch, M.; Diskin, G. S.; Sachse, G. W.

    2009-12-01

    The Coal Oil Point (COP) hydrocarbon seep field off the coast of Santa Barbara, CA is one of the most active and best-studied marine geologic methane sources in the world and contributes to elevated terrestrial methane concentrations downwind. In this study, we investigate the spatiotemporal variability of this local source and the influence of meteorological conditions on transport and concentration. A methane plume emanating from Trilogy Seep was mapped with the Airborne Visible Infrared Imaging Spectrometer at a 7.5 m resolution with a short-wave infrared band ratio technique. This structure agrees with the local wind speed and direction and is orthogonal to the surface currents. ARCTAS-CARB aircraft in situ sampling of lower-troposphere methane is compared to sub-hour total hydrocarbon concentration (THC) measurements from the Santa Barbara Air Pollution Control District (SBAPCD) station located near COP. Hourly SBAPCD THC values from 1980-2008 demonstrate a decrease in seep source strength until the late 1990s, followed by a consistent increase. The occurrence of elevated SBAPCD THC values for onshore wind conditions as well as numerous positive outliers as high as 17 ppm suggests that seep field emissions are both quasi-steady state and transient, direct (bubble) and diffuse (outgassing). As demonstrated for the COP seeps, the combination of imaging spectrometry, aircraft in situ sampling, and ground-based monitoring provides a powerful approach for understanding local methane sources and transport processes.

  2. [An automatic and sensitive method for the determination of endogenous brassinosteroids in plant tissues by an online trapping-in situ derivatization-ultra performance liquid chromatography-tandem mass spectrometry system].

    PubMed

    Ding, Jun; Jiang, Li; Feng, Yuqi

    2014-10-01

    Brassinosteroids (BRs) are a class of naturally occurring phytohormones with poly- hydroxy steroid structure, which regulate general plant growth and many physiological processes. The reported methods for BR analysis were complicated, and the detection sensitivity was relatively low. To realize the automatic analysis of trace BRs in limited plant tissues, an in-tube solid phase microextraction-ultra performance liquid chromatography-tandem mass spectrometry (SPME-UPLC-MS/MS) system was constructed based on two valves-two pumps. Using C18 PEEK column as the trapping column and 4-(dimethylamino) phenylboronic acid (4-DMAPBA) as the derivatization reagent, an on line trapping and in situ derivatization assay method of BRs was developed. BRs could be programmed to fulfill the procedures of injection, extraction, derivatization, LC separation and MS detection in the system. The detection limits of BRs were improved more than one order of magnitude by the online trapping and in situ derivatization techniques, thus endogenous BRs could be quantified in only 300 mg plant tissues. PMID:25739270

  3. Determination of the natural radioactivity in Qatarian building materials using high-resolution gamma-ray spectrometry

    NASA Astrophysics Data System (ADS)

    Al-Sulaiti, Huda; Alkhomashi, N.; Al-Dahan, N.; Al-Dosari, M.; Bradley, D. A.; Bukhari, S.; Matthews, M.; Regan, P. H.; Santawamaitre, T.

    2011-10-01

    This study is aimed at the determination of the activity concentrations of naturally occurring and technically enhanced levels of radiation in building materials used across the State of Qatar. Samples from a range of common building materials, including Qatarian cement, Saudi cement, white cement, sand and washed sand, have been analyzed, in addition to other samples of cement's raw materials and additives collected from the main suppliers in Qatar. In order to establish the activity concentrations associated with the 235,8U and 232Th natural decay chains and 40K, the samples have been studied using a high-resolution, low-background gamma-ray spectrometry set-up. Details of the sample preparation and the gamma-ray spectroscopic analysis techniques are presented, together with the preliminary results of the activity concentrations associated with the naturally occurring radionuclide chains for the building materials collected across the Qatarian peninsula.

  4. Investigation of Failed TRISO Fuel Assay Using Gamma-Ray Spectrometry

    NASA Astrophysics Data System (ADS)

    Harp, Jason Michael

    TRISO microsphere fuel is the fundamental fuel unit for Very High Temperature Reactors (VHTR). A single TRISO particle consists of an inner kernel of Uranium Oxycarbide surrounded by layers of pyrolytic carbon and silicon carbide. The silicon carbide serves as the primary barrier to the release of fission products into the core. If the silicon carbide layer fails, fission gas, especially Kr and Xe, will begin to escape the failed particle. In order to understand the behavior of TRISO fuel under in-core conditions, a series of experiments is being conducted by Idaho National Lab at the Advanced Test Reactor. AGR-1 is the first of these experiments. It will measure fission product release due to failed TRISO particles. Simulations of this experiment have been conducted at North Carolina State University to develop a method for the analysis of the results of the experiment. The ATR core was simulated using the Monte Carlo code MCNP to calculate the expected neutron energy spectrum for the AGR-1 experimental test train. This spectrum was used to create one-group cross sections for implementation in ORIGEN calculations of the amount of activity produced in the experiment. Several theoretical models have been developed to describe the phenomenon of gas release. While each model is based on similar physics, different models contain unique features that distinguish them from one another. These Release to Birth (R/B) models are developed and applied to the activity found in the ORIGEN calculations to create expected release activities. The release activity is used to create gamma-ray spectra that are representative of the different R/B models. Expected R/B due to a model can be calculated for comparison to the experiment with knowledge of the number of failed particles in the spectra. The comparison of measured to predicted R/B ratios gives insight into the physics of release and also helps validate specific models. Direct comparison is possible, but many of the uncertainties associated with direct comparison are nullified through the use of relative indicators. Each R/B model has a unique set of indicators that reflect the physical processes simulated in the model. Trends in the model indicators can be matched up with trends in indicators derived from the release spectra to validate either an entire model or validate the need to consider certain parameters in the creation of a complete and successful release to birth model. Gamma spectrometry is a useful tool for the understanding of fission gas release from failed TRISO particles. A better understanding of the processes that influence fission gas release will influence the fuel manufacturing and quality assurance protocols during the continued development of the VHTR. Future work in this area includes experiment in which the conditions can be better controlled to document the effects of temperature and fission rate in the fuel.

  5. A rapid dissolution procedure to aid initial nuclear forensics investigations of chemically refractory compounds and particles prior to gamma spectrometry.

    PubMed

    Reading, David G; Croudace, Ian W; Warwick, Phillip E; Britton, Richard

    2015-11-01

    A rapid and effective preparative procedure has been evaluated for the accurate determination of low-energy (40-200 keV) gamma-emitting radionuclides ((210)Pb, (234)Th, (226)Ra, (235)U) in uranium ores and uranium ore concentrates (UOCs) using high-resolution gamma ray spectrometry. The measurement of low-energy gamma photons is complicated in heterogeneous samples containing high-density mineral phases and in such situations activity concentrations will be underestimated. This is because attenuation corrections, calculated based on sample mean density, do not properly correct where dense grains are dispersed within a less dense matrix (analogous to a nugget effect). The current method overcomes these problems using a lithium tetraborate fusion that readily dissolves all components including high-density, self-attenuating minerals/compounds. This is the ideal method for dissolving complex, non-volatile components in soils, rocks, mineral concentrates, and other materials where density reduction is required. Lithium borate fusion avoids the need for theoretical efficiency corrections or measurement of matrix matched calibration standards. The resulting homogeneous quenched glass produced can be quickly dissolved in nitric acid producing low-density solutions that can be counted by gamma spectrometry. The effectiveness of the technique is demonstrated using uranium-bearing Certified Reference Materials and provides accurate activity concentration determinations compared to the underestimated activity concentrations derived from direct measurements of a bulk sample. The procedure offers an effective solution for initial nuclear forensic studies where complex refractory minerals or matrices exist. It is also significantly faster, safer and simpler than alternative approaches. PMID:26572834

  6. IN-SITU ASSAY OF TRANSURANIC RADIONUCLIDES IN THE VADOSE ZONE USING HIGH-RESOLUTION SPECTRAL GAMMA LOGGING - A HANFORD CASE STUDY

    SciTech Connect

    ROHAY VJ; HENWOOD P; MCCAIN R

    2009-11-30

    High-resolution spectral gamma logging in steel-cased boreholes is used to detect and quantify transuranic radionuclides in the subsurface. Pu-239, Pu-241, Am-241, and Np-237 are identified based on characteristic decay gammas. Typical minimum detectable levels are on the order of 20 to 40 nCi/g. In intervals of high transuranic concentrations, gamma rays from other sources may complicate analysis and interpretation. Gamma rays detected in the borehole may originate from three sources: decay of the parent transuranic radionuclide or a daughter; alpha interactions; and interactions with neutrons resulting from either spontaneous fission or alpha particle interactions.

  7. A method for determining the analytical form of a radionuclide depth distribution using multiple gamma spectrometry measurements.

    PubMed

    Dewey, Steven Clifford; Whetstone, Zachary David; Kearfott, Kimberlee Jane

    2011-06-01

    When characterizing environmental radioactivity, whether in the soil or within concrete building structures undergoing remediation or decommissioning, it is highly desirable to know the radionuclide depth distribution. This is typically modeled using continuous analytical expressions, whose forms are believed to best represent the true source distributions. In situ gamma ray spectroscopic measurements are combined with these models to fully describe the source. Currently, the choice of analytical expressions is based upon prior experimental core sampling results at similar locations, any known site history, or radionuclide transport models. This paper presents a method, employing multiple in situ measurements at a single site, for determining the analytical form that best represents the true depth distribution present. The measurements can be made using a variety of geometries, each of which has a different sensitivity variation with source spatial distribution. Using non-linear least squares numerical optimization methods, the results can be fit to a collection of analytical models and the parameters of each model determined. The analytical expression that results in the fit with the lowest residual is selected as the most accurate representation. A cursory examination is made of the effects of measurement errors on the method. PMID:21482447

  8. Particulate-matter distribution and its flow from power plants using infrared spectrometry and thermodynamics for in situ continuous emissions monitoring.

    PubMed

    Shlifshteyn, A; Lang, F D; Ayrapetian, R

    1996-01-20

    Spectroscopy measurements made through a continuum having suspended particulate matter are addressed. The applications presented permit correction of spectral transmissions as effected by particulate-producing fossil-fuel combustion. The research is especially applicable to large effluent flows from coal-fired power plants, whose effluents are studied with in situ (smokestack) radiometers. Methods involving fast calculation procedures based on measured irradiances in unabsorbed regions of the IR spectrum are presented. The methodology is based on wavelength-dependent extinction of radiation by small particles, considering both elastic scattering and absorbing effects. This extinction leads to an observed skeweness (or shift) of the blackbody spectral shape. Based on such skeweness, the particulate number distribution is determined with Mie theory. In order to simplify, and to speed up the routine for real-time application, a two-step procedure is presented. During preinstallation calibration with Mie theory, sets of integral tables are computed for all possible solution values and stored in computer memory. Based on instantaneous spectral measurements, the appropriate integral tables are retrieved, then used as inputs in a process leading to particulate number distribution. Because all time-consuming calculations associated with Mie theory are performed during preinstallation calibration, the technique is capable of monitoring particulate emission in real time. Furthermore, given resolution of the number distribution in combination with thermodynamic analysis of the system, determination of particulate apparent density and particulate mass flow rate is made. These values have importance for environmental reporting. Comparisons of calculated particulate distributions with in situ measurements are also presented. Confirmatory testing programs conducted at several power plants are discussed. PMID:21069018

  9. Study on stable coatings for determination of lead by flow-injection hydride generation and in situ concentration in graphite furnace atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Haug, H. O.

    1996-09-01

    Lead hydride was generated by flow-injection from 0.05 M oxalic acid sample solution by using 0.1 M HCl carrier solution and the reaction with 1.5% sodium borohydride in the presence of 2% potassium hexacyanoferrate(III) as a mild oxidizing agent. Pb was determined by in situ concentration in graphite furnace AAS. The hydride generation by flow-injection and trapping in the graphite tube coated with a highly stable trapping reagent (e.g. tungsten) allows automatic Pb determination. In a systematic investigation, the in situ concentration of Pb was studied in the temperature range 50-600 on graphite tubes coated with noble metals (Ir, Ir/Mg, Pd/Ir), and with W or Zr. The highest response was found on the Ir coatings at trapping temperatures of 200-300, followed by the W and Zr coatings. The radiotracer 210Pb was used to measure hydride generation (95%) and trapping efficiency (71%) on a W-coated tube. Signal stability and reproducibility was tested over 400 trapping and atomization cycles, and the better performance was found with the W and Zr coatings at a precision of 3%. Trapping temperatures above 450C can lead to errors in absorbance values owing to an adsorptive "carry-over" effect. A characteristic mass of about 21 pg Pb for W-coated tube (283.3 nm) and a detection limit (3?) of about 0.25 ng was obtained with a 0.5 ml sample loop. The problem with Pb hydride generation is the relatively high reagent blank (1.3 ng in 30 s trapping time) even using chemicals of the highest purity. The method has been tested by applying it to the determination of Pb in a sediment certified reference material.

  10. X-ray remote sensing and in-situ spectroscopy for planetary exploration missions and gamma-ray remote sensing and in-situ spectroscopy for planetary exploration missions

    NASA Technical Reports Server (NTRS)

    Mahdavi, M.; Giboni, K. L.; Vajda, S.; Schweitzer, J.

    1994-01-01

    Detectors that will be used for planetary missions must have their responses calibrated in a reproducible manner. A calibration facility is being constructed at Schlumberger-Doll Research for gamma and x ray detectors. With this facility the detector response can be determined in an invariant and reproducible fashion. Initial use of the facility is expected for the MARS94 detectors. Work is continuing to better understand the rare earth oxyorthosilicates and to define their characteristics. This will allow a better use of these scintillators for planetary missions. In a survey of scintillating materials two scintillators were identified as promising candidates besides GSO, LSO, and YSO. These are CdWO4 and CsI(Tl). It will be investigated if a detector with a better overall performance can be assembled with various photon converters. Considerable progress was achieved in photomultiplier design. The length of an 1 inch diameter PMT could be reduced from 4.2 to 2.5 inches without performance degradation. This technology is being employed in the gamma ray detector for the NEAR project. A further weight and size reduction of the detector package can be achieved with miniaturized integrated power supplies.

  11. Application of a fast and cost-effective in situ derivatization method prior to gas chromatography with mass spectrometry to monitor endocrine disruptors in water matrices.

    PubMed

    Melo, Armindo; Ferreira, Isabel M P L V O; Mansilha, Catarina

    2015-06-01

    This work deals with the optimization of a rapid, cost-effective, and eco-friendly gas chromatography with mass spectrometry method for the simultaneous determination of four endocrine disruptor compounds in water matrices: estrone, 17?-estradiol, 17?-ethinylestradiol, and bisphenol A, that are currently considered to be of main concern in the field of water policy and that could became candidates for future regulations. The method involves simultaneous derivatization and extraction of compounds by dispersive liquid-liquid microextraction followed by gas chromatography with mass spectrometry analysis. Derivatization and extraction parameters were optimized with the aid of experimental design approach. An excellent linear response was achieved for all analytes (r(2) ? 0.999). Limits of detection and quantification are 0.003-0.005 and 0.0094-0.0164 ?g/L, respectively. Intraday precision ranged between 1.1 and 12.6%, whereas interday precision ranged between 0.5 and 14.7%. For accuracy, bias values varied between -15.0 and 13.7%. Recoveries at three concentration levels ranged from 86.4 to 118.2%. The proposed method can be applied to the routine analysis of groundwater, river, sea, tap, and mineral water samples with excellent sensitivity, precision, and accuracy. PMID:25821146

  12. In situ derivatization combined to automated microextraction by packed sorbents for the determination of chlorophenols in soil samples by gas chromatography mass spectrometry.

    PubMed

    González Paredes, Rosa María; García Pinto, Carmelo; Pérez Pavón, José Luis; Moreno Cordero, Bernardo

    2014-09-12

    A method based on the coupling of in situ extraction and derivatization of chlorophenols (CPs) (2-chlorophenol, 4-chloro-3-methylphenol, 2,4-dichlorophenol, and 2,4,6-trichlorophenol) from soils, accomplishing their preconcentration by means of automated microextraction by packed sorbent (MEPS), is proposed. After extraction and acylation of the chlorophenols in aqueous medium, the liquid phase obtained is subjected to the MEPS procedure. The QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) and MEPS techniques were compared and the results confirmed the preconcentration carried out with MEPS. The existence of a matrix effect was checked and the analytical characteristics of the method were determined in a soil sample. The method provided good linearity (from 1 to 12μgkg(-1)), together with good repeatability and reproducibility values (RSD equal to or less than 10%). The limits of detection were in the 0.118-0.894μgkg(-1) range. A certified reference material was applied to validate the proposed methodology. PMID:25113872

  13. Graphene oxide-based dispersive solid-phase extraction combined with in situ derivatization and gas chromatography-mass spectrometry for the determination of acidic pharmaceuticals in water.

    PubMed

    Naing, Nyi Nyi; Li, Sam Fong Yau; Lee, Hian Kee

    2015-12-24

    A fast and low-cost sample preparation method of graphene based dispersive solid-phase extraction combined with gas chromatography-mass spectrometric (GC-MS) analysis, was developed. The procedure involves an initial extraction with water-immiscible organic solvent, followed by a rapid clean-up using amine functionalized reduced graphene oxide as sorbent. Simple and fast one-step in situ derivatization using trimethylphenylammonium hydroxide was subsequently applied on acidic pharmaceuticals serving as model analytes, ibuprofen, gemfibrozil, naproxen, ketoprofen and diclofenac, before GC-MS analysis. Extraction parameters affecting the derivatization and extraction efficiency such as volume of derivatization agent, effect of desorption solvent, effect of pH and effect of ionic strength were investigated. Under the optimum conditions, the method demonstrated good limits of detection ranging from 1 to 16ngL(-1), linearity (from 0.01 to 50 and 0.05 to 50μgL(-1), depending on the analytes) and satisfactory repeatability of extractions (relative standard deviations, below 13%, n=3). PMID:26684593

  14. A method for the comparison of performance of gamma-ray spectrometry calibration cocktails.

    PubMed

    Legarda, F; Los Arcos, J M; Herranz, M

    2004-01-01

    In order to make quantitative assessments about the usefulness of different gamma-ray emitting radionuclide cocktails to carry out efficiency calibrations of gamma-ray spectrometers, a method has been developed that allows the comparison of their different performances and to optimize the choice of gamma energy lines for the radionuclides within a specific cocktail. The method has been applied to compare different cocktail configurations obtained from measurements made in the laboratory with monoenergetic radionuclides, and their relative performances are presented and discussed. PMID:14987701

  15. Detection of in-situ derivatized peptides in microbial biofilms by laser desorption 7.87 eV postionizaton mass spectrometry.

    SciTech Connect

    Edirisinghe, P. D.; Moore, J. F.; Skinner-Nemec, K. A.; Lindberg, C.; Giometti, C. S.; Veryovkin, I. V.; Hunt, J. E.; Pellin, M. J.; Hanley, L.; Biosciences Division; Univ. of Illinois at Chicago; MassThink

    2007-01-01

    A novel analytical method based on laser desorption postionization mass spectrometry (LDPI-MS) was developed to investigate the competence and sporulation factor-a pentapeptide of amino acid sequence ERGMT-within intact Bacillus subtilis biofilms. Derivatization of the neat ERGMT peptide with quinoline- and anthracene-based tags was separately used to lower the peptide ionization potential and permit direct ionization by 7.87-eV vacuum ultraviolet radiation. The techniques of mass shifting and selective ionization of the derivatized peptide were combined here to permit detection of ERGMT peptide within intact biofilms by LDPI-MS, without any prior extraction or chromatographic separation. Finally, imaging MS specific to the derivatized peptide was demonstrated on an intact biofilm using LDPI-MS. The presence of ERGMT in the biofilms was verified by bulk extraction/LC-MS. However, MALDI imaging MS analyses were unable to detect ERGMT within intact biofilms.

  16. A broadband gamma-ray spectrometry using novel unfolding algorithms for characterization of laser wakefield-generated betatron radiation

    NASA Astrophysics Data System (ADS)

    Jeon, Jong Ho; Nakajima, Kazuhisa; Kim, Hyung Taek; Rhee, Yong Joo; Pathak, Vishwa Bandhu; Cho, Myung Hoon; Shin, Jung Hun; Yoo, Byung Ju; Hojbota, Calin; Jo, Sung Ha; Shin, Kang Woo; Sung, Jae Hee; Lee, Seung Ku; Cho, Byeoung Ick; Choi, Il Woo; Nam, Chang Hee

    2015-12-01

    We present a high-flux, broadband gamma-ray spectrometry capable of characterizing the betatron radiation spectrum over the photon energy range from 10 keV to 20 MeV with respect to the peak photon energy, spectral bandwidth, and unique discrimination from background radiations, using a differential filtering spectrometer and the unfolding procedure based on the Monte Carlo code GEANT4. These properties are experimentally verified by measuring betatron radiation from a cm-scale laser wakefield accelerator (LWFA) driven by a 1-PW laser, using a differential filtering spectrometer consisting of a 15-filter and image plate stack. The gamma-ray spectra were derived by unfolding the photostimulated luminescence (PSL) values recorded on the image plates, using the spectrometer response matrix modeled with the Monte Carlo code GEANT4. The accuracy of unfolded betatron radiation spectra was assessed by unfolding the test PSL data simulated with GEANT4, showing an ambiguity of less than 20% and clear discrimination from the background radiation with less than 10%. The spectral analysis of betatron radiation from laser wakefield-accelerated electron beams with energies up to 3 GeV revealed radiation spectra characterized by synchrotron radiation with the critical photon energy up to 7 MeV. The gamma-ray spectrometer and unfolding method presented here facilitate an in-depth understanding of betatron radiation from LWFA process and a novel radiation source of high-quality photon beams in the MeV regime.

  17. A broadband gamma-ray spectrometry using novel unfolding algorithms for characterization of laser wakefield-generated betatron radiation.

    PubMed

    Jeon, Jong Ho; Nakajima, Kazuhisa; Kim, Hyung Taek; Rhee, Yong Joo; Pathak, Vishwa Bandhu; Cho, Myung Hoon; Shin, Jung Hun; Yoo, Byung Ju; Hojbota, Calin; Jo, Sung Ha; Shin, Kang Woo; Sung, Jae Hee; Lee, Seung Ku; Cho, Byeoung Ick; Choi, Il Woo; Nam, Chang Hee

    2015-12-01

    We present a high-flux, broadband gamma-ray spectrometry capable of characterizing the betatron radiation spectrum over the photon energy range from 10 keV to 20 MeV with respect to the peak photon energy, spectral bandwidth, and unique discrimination from background radiations, using a differential filtering spectrometer and the unfolding procedure based on the Monte Carlo code GEANT4. These properties are experimentally verified by measuring betatron radiation from a cm-scale laser wakefield accelerator (LWFA) driven by a 1-PW laser, using a differential filtering spectrometer consisting of a 15-filter and image plate stack. The gamma-ray spectra were derived by unfolding the photostimulated luminescence (PSL) values recorded on the image plates, using the spectrometer response matrix modeled with the Monte Carlo code GEANT4. The accuracy of unfolded betatron radiation spectra was assessed by unfolding the test PSL data simulated with GEANT4, showing an ambiguity of less than 20% and clear discrimination from the background radiation with less than 10%. The spectral analysis of betatron radiation from laser wakefield-accelerated electron beams with energies up to 3 GeV revealed radiation spectra characterized by synchrotron radiation with the critical photon energy up to 7 MeV. The gamma-ray spectrometer and unfolding method presented here facilitate an in-depth understanding of betatron radiation from LWFA process and a novel radiation source of high-quality photon beams in the MeV regime. PMID:26724015

  18. In-situ infrared spectroelectrochemistry. Report No. 44. Technical report

    SciTech Connect

    Pons, S.; Foley, J.K.

    1986-07-30

    In-situ infrared (IR) spectroelectrochemistry has become a viable experimental technique only within about the past five years, but it has already proved to be an important addition to the small number of in-situ spectroelectrochemical methods currently in use (electron spin resonance spectrometry, ellipsometry, uv-visible spectrometry,resonance Raman, and surface-enhanced Raman spectrometry),. The technique has found two broad areas of application.

  19. A prototype of radioactive waste drum monitor by non-destructive assays using gamma spectrometry.

    PubMed

    Thanh, Tran Thien; Trang, Hoang Thi Kieu; Chuong, Huynh Dinh; Nguyen, Vo Hoang; Tran, Le Bao; Tam, Hoang Duc; Tao, Chau Van

    2016-03-01

    In this work, segmented gamma scanning and the gamma emission tomography were used to locate unknown sources in a radioactive waste drum. The simulated detector response function and full energy peak efficiency are compared to corresponding experimental data and show about 5.3% difference for an energy ranging from 81keV to 1332.5keV for point sources. Computation of the corresponding activity is in good agreement with the true values. PMID:26717796

  20. Determination of gamma radioactivity levels and associated dose rates of soil samples of the Akkuyu/Mersin using high-resolution gamma-ray spectrometry.

    PubMed

    Ozmen, S F; Boztosun, I; Yavuz, M; Tun, M R

    2014-03-01

    In this study several soil samples were collected from the Bykeceli district where Turkey's first nuclear power plant will be built and radioactivity concentrations of (226)Ra, (232)Th, (40)K and (137)Cs were determined by gamma spectrometry using a high-purity germanium detector. The measured activity concentrations in soil samples ranged from 9.8 0.7 to 258.6 15.8, 11.7 0.9 to 85.6 5.0, 173.8 2.1 to 1949.5 14.7 and 0.4 0.1 to 72.2 2.2 Bq kg(-1) for (226)Ra, (232)Th, (40)K and (137)Cs, respectively. Findings are in good agreement with the published results of neighbouring areas. The absorbed gamma dose rate (D) in air and the annual effective dose of soil samples were calculated to be 80.2 nGy h(-1) and 98.3 mSv y(-1), respectively. The results show that the radiation hazard in the Bykeceli district is insignificant. The data presented in this study would be very useful to determine the future effects of the nuclear power plant to the environment. PMID:24214909

  1. In-situ submicron organic aerosol characterization at a boreal forest research station during HUMPPA-COPEC 2010 using soft and hard ionization mass spectrometry

    NASA Astrophysics Data System (ADS)

    Vogel, A. L.; ijl, M.; Corrigan, A. L.; Junninen, H.; Ehn, M.; Petj, T.; Worsnop, D. R.; Kulmala, M.; Russell, L. M.; Williams, J.; Hoffmann, T.

    2013-07-01

    The chemical composition of submicron aerosol during the comprehensive field campaign HUMPPA-COPEC 2010 at Hyytil, Finland is presented. The focus lies on online measurements of organic acids, which was achieved by using atmospheric pressure chemical ionization (APCI) ion trap mass spectrometry (IT-MS). These measurements were accompanied by Aerosol Mass Spectrometry (AMS) measurements and Fourier-Transform Infrared Spectroscopy (FTIR) of filter samples, all showing a high degree of correlation. The soft ionization mass spectrometer alternated between gas phase measurements solely and measuring the sum of gas- and particle-phase. The AMS measurements of C, H and O elemental composition show that the aerosol during the campaign was highly oxidized, which appears reasonable due to high and prolonged radiation during the boreal summer measurement period as well as the long transport times of some of the aerosol. In order to contrast ambient and laboratory aerosol, an average organic acid pattern, measured by APCI-IT-MS during the campaign, was compared to terpene ozonolysis products in a laboratory reaction chamber. Identification of single organic acid species remains a major challenge due to the complexity of the boreal forest aerosol. Unambiguous online species identification was attempted by the combinatorial approach of identifying unique fragments in the MS2-mode of standards, and then comparing these results with MS2 field spectra. During the campaign, unique fragments of limonene derived organic acids (limonic acid and ketolimononic acid) and of the biomass burning tracer vanillic acid were detected. Other specific fragments (neutral loss of 28 Da) in the MS2 suggest the occurrence of semialdehydes. Furthermore, an approach to determine the average molecular weight of the aerosol is presented. The campaign average organic molecular weight was determined to be 300 g mol-1. However, a plume of aged biomass burning aerosol, arriving at Hyytil from Russia, contained organic compounds up to 800 Da (MWom ? 450 g mol-1), showing that the average molecular weight can vary significantly. The high measurement frequency of both, AMS and APCI-IT-MS, enabled the partitioning of selected organic acids between gas- and particle-phase as a function of the total particulate mass to be quantified. Surprisingly high fractions of the higher molecular weight organic acids were observed to reside in the gas phase. These observations might be a consequence of large equilibration timescales for semi-solid boreal forest aerosol, as it has been recently hypothesised by Shiraiwa and Seinfeld (2012).

  2. In situ submicron organic aerosol characterization at a boreal forest research station during HUMPPA-COPEC 2010 using soft and hard ionization mass spectrometry

    NASA Astrophysics Data System (ADS)

    Vogel, A. L.; Äijälä, M.; Corrigan, A. L.; Junninen, H.; Ehn, M.; Petäjä, T.; Worsnop, D. R.; Kulmala, M.; Russell, L. M.; Williams, J.; Hoffmann, T.

    2013-11-01

    The chemical composition of submicron aerosol during the comprehensive field campaign HUMPPA-COPEC 2010 at Hyytiälä, Finland, is presented. The focus lies on online measurements of organic acids, which were achieved by using atmospheric pressure chemical ionization (APCI) ion trap mass spectrometry (IT-MS). These measurements were accompanied by aerosol mass spectrometry (AMS) measurements and Fourier transform infrared spectroscopy (FTIR) of filter samples, all showing a high degree of correlation. The soft ionization mass spectrometer alternated between gas-phase measurements solely and measuring the sum of gas and particle phase. The AMS measurements of C, H and O elemental composition show that the aerosol during the campaign was highly oxidized, which appears reasonable due to high and prolonged radiation during the boreal summer measurement period as well as the long transport times of some of the aerosol. In order to contrast ambient and laboratory aerosol, an average organic acid pattern, measured by APCI-IT-MS during the campaign, was compared to terpene ozonolysis products in a laboratory reaction chamber. Identification of single organic acid species remains a major challenge due to the complexity of the boreal forest aerosol. Unambiguous online species identification was attempted by the combinatorial approach of identifying unique fragments in the MS2 mode of standards, and then comparing these results with MS2 field spectra. During the campaign, unique fragments of limonene-derived organic acids (limonic acid and ketolimononic acid) and of the biomass burning tracer vanillic acid were detected. Other specific fragments (neutral loss of 28 Da) in the MS2 suggest the occurrence of semialdehydes. Furthermore, an approach to determine the average molecular weight of the aerosol is presented. The campaign average organic molecular weight was determined to be 300 g mol-1. However, a plume of aged biomass burning aerosol, arriving at Hyytiälä from Russia, contained organic compounds up to 800 Da (MWom≈450 g mol-1), showing that the average molecular weight can vary significantly. The high measurement frequency of both AMS and APCI-IT-MS enabled the partitioning of selected organic acids between gas and particle phase as a function of the total particulate mass to be quantified. Surprisingly high fractions of the higher molecular weight organic acids were observed to reside in the gas phase. These observations might be a consequence of large equilibration timescales for semi-solid boreal forest aerosol, as has been recently hypothesized by Shiraiwa and Seinfeld (2012).

  3. Suitability of dispersive liquid-liquid microextraction for the in situ silylation of chlorophenols in water samples before gas chromatography with mass spectrometry.

    PubMed

    Saraji, Mohammad; Ghambari, Hoda

    2015-10-01

    Trace analysis of chlorophenols in water was performed by simultaneous silylation and dispersive liquid-liquid microextraction followed by gas chromatography with mass spectrometry. Dispersive liquid-liquid microextraction was carried out using an organic solvent lighter than water (n-hexane). The effect of different silylating reagents on the method efficiency was investigated. The influence of derivatization reagent volume, presence of catalyst and derivatization/extraction time on the yield of the derivatization reaction was studied. Different parameters affecting extraction efficiency such as kind and volume of extraction and disperser solvents, pH of the sample and addition of salt were also investigated and optimized. Under the optimum conditions, the calibration graphs were linear in the range of 0.05-100 ng/mL and the limit of detection was 0.01 ng/mL. The enrichment factors were 242, 351, and 363 for 4-chlorophenol, 2,4-dichlorophenol, and 2,4,6-trichlorophenol, respectively. The values of intra- and inter-day relative standard deviations were in the range of 3.0-6.4 and 6.1-9.9%, respectively. The applicability of the method was investigated by analyzing water and wastewater samples. PMID:26257251

  4. In situ real-time studies of oxygen incorporation in complex oxide thin films using spectroscopic ellipsometry and ion scattering and recoil spectrometry

    SciTech Connect

    Mueller, A. H.; Gao, Y.; Irene, E. A.; Auciello, O.; Krauss, A. R.; Achultz, J. A.

    2000-05-25

    The surface termination of c-axis oriented YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} (YBCO) and the oxygen incorporation mechanism has been investigated using a unique combination of spectroscopic ellipsometry (SE) and time of flight ion scattering and recoil spectrometry (ToF-ISARS). The high surface sensitivity of the ToF-ISARS technique combined with the bulk oxygen sensitivity of SE are shown to yield complimentary information. The SE provided the film orientation and quality, while ToF-ISARS supplied surface compositional and structural information and enabled isotopic {sup 18}O tracer studies. It was determined that the O content of the film had little effect on the surface termination of the film, indicating a lack of labile Cu(1) sites at the c-axis oriented YBCO surface. Also, strong evidence for a Ba or BaO terminated structure is shown. The data related to the {sup 18}O tracer studies indicate that O from the reaction ambient incorporates only into the labile Cu(1) sites during both deposition and annealing, while stable O sites were populated with O from the sputtered target, indicating either the need for sputtered atomic O or sputtered YCuO complexes to occupy the stable Cu(2) sites.

  5. High resolution gamma-ray spectrometry of culverts containing transuranic waste at the Savannah River Site

    SciTech Connect

    Hofstetter, K.J.; Sigg, R.

    1990-12-31

    A number of concrete culverts used to retrievably store drummed, dry, radioactive waste at the Savannah River Site (SRS), were suspected of containing ambiguous quantities of transuranic (TRU) nuclides. These culverts were assayed in place for Pu-239 content using thermal and fast neutron counting techniques. High resolution gamma-ray spectroscopy on 17 culverts, having neutron emission rates several times higher than expected, showed characteristic gamma-ray signatures of neutron emitters other than Pu-239 (e.g., Pu-238, Pu/Be, or Am/Be neutron sources). This study confirmed the Pu-239 content of the culverts with anomalous neutron rates and established limits on the Pu-239 mass in each of the 17 suspect culverts by in-field, non-intrusive gamma-ray measurements.

  6. High resolution gamma-ray spectrometry of culverts containing transuranic waste at the Savannah River Site

    SciTech Connect

    Hofstetter, K.J.; Sigg, R.

    1990-01-01

    A number of concrete culverts used to retrievably store drummed, dry, radioactive waste at the Savannah River Site (SRS), were suspected of containing ambiguous quantities of transuranic (TRU) nuclides. These culverts were assayed in place for Pu-239 content using thermal and fast neutron counting techniques. High resolution gamma-ray spectroscopy on 17 culverts, having neutron emission rates several times higher than expected, showed characteristic gamma-ray signatures of neutron emitters other than Pu-239 (e.g., Pu-238, Pu/Be, or Am/Be neutron sources). This study confirmed the Pu-239 content of the culverts with anomalous neutron rates and established limits on the Pu-239 mass in each of the 17 suspect culverts by in-field, non-intrusive gamma-ray measurements.

  7. A convenient method for discriminating between natural and depleted uranium by gamma-ray spectrometry.

    PubMed

    Shoji, M; Hamajima, Y; Takatsuka, K; Honoki, H; Nakajima, T; Kondo, T; Nakanishi, T

    2001-08-01

    A convenient method for discriminating between natural and depleted uranium reagent was developed by measuring and analyzing the gamma-ray spectra of some reagents with no standard source. The counting rates (R) of photoelectric peaks of gamma-rays from nuclides with the same radioactivity divided by their emission probability (B) are expressed as a function of gamma-ray energy. The radioactivities of 234Th and 234mPa and 21.72 times that of 235U are equal to the radioactivity of 235U in natural uranium. Therefore, the plot of 21.72-fold R/B for 235U should be on a curve fitted to the points for 234Th and 234mPa in natural uranium. Depleted uranium with a 235U isotopic composition of less than 0.68% could be discriminated from natural uranium in the case of a reagent containing 4.0 g of uranium. PMID:11393763

  8. Evaluation of an automated assay system to measure soil radionuclides by L x-ray and gamma-ray spectrometry

    SciTech Connect

    Nyhan, J.W.; Drennon, B.J.; Crowell, J.M.

    1982-08-01

    An automated radionuclide assay system for conducting soil radioassays using L x-ray and gamma-ray spectrometry was evaluated. Wet chemistry assay procedures were shown to be considerably more time consuming than similar analyses of soil on this radionuclide assay system. The detection limits of /sup 241/Am and plutonium were determined, as well as the reproducibility of radionuclide assay results. The L x-ray spectrometric measurements were compared with radiochemical analyses on several tuff samples. The assay system's intrinsic germanium detector was found to respond linearly to varying low concentrations of /sup 241/Am and plutonium, both of which were easily detected in the presence of elevated concentrations of /sup 137/Cs.

  9. A denuder-impinger system with in situ derivatization followed by gas chromatography-mass spectrometry for the determination of gaseous iodine-containing halogen species.

    PubMed

    Huang, Ru-Jin; Hoffmann, Thorsten

    2008-11-14

    Reactive iodine species have been suggested to play an important role in the atmosphere (e.g. tropospheric ozone depletion, coastal new particle formation). However, there still exist major uncertainties about their atmospheric chemistry, mostly due to the lack of analytical approaches for the accurate speciation of certain key compounds. In this study, 1,3,5-trimethoxybenzene (1,3,5-TMB)-coated denuder proved to be suitable for the differentiation between gaseous interhalogens (iodine monochloride (ICl), iodine monobromide (IBr)) and molecular iodine (I2) based on a selective collection/derivatization method. The results of the denuder sampling were compared with the results of impinger sampling in water, methanol and carbon tetrachloride solutions of 1,3,5-TMB. ICl and IBr are converted into 1-iodo-2,4,6-trimethoxybenzene (1-iodo-2,4,6-TMB) and 1-bromo-2,4,6-trimethoxybenzene (1-bromo-2,4,6-TMB), respectively, in the denuder systems. The respective collection efficiency is 99.2% for ICl and 92.6% for IBr, at 500mLmin(-1) gas flow rate. The collection efficiency for I2 is lower than 1% in the same denuder system, but significantly increases to about 90% in the aqueous 1,3,5-TMB loaded impinger. The denuder-impinger coupled system was then used to differentiate and to collect the ICl, IBr and I2 gas mixtures, followed by gas chromatography-ion trap mass spectrometry (GC-MS) determination. The precision of the method is in general better than 9.1%. The parameters affecting denuder operation including sampling flow rate, sampling duration, and relative humidity have been evaluated. The presented method provides an attractive protocol for iodine species analysis for atmospheric chemistry research. PMID:18849042

  10. In situ analysis of precious metals in polished mineral samples and sulphido "standards" by Accelerator Mass Spectrometry at concentrations of parts-per-billion

    NASA Astrophysics Data System (ADS)

    Wilson, Graham C.; Kilius, Linas R.; Rucklidge, John C.

    1991-08-01

    This article addresses the analysis of eight precious metals (Au and Ag, plus the six Platinum Group Elements (PGE): Pt, Ir, Os, Ru, Rh, and Pd). The metals are measured in Fe-Ni-(Cu) sulphidos by Accelerator Mass Spectrometry (AMS). Samples are analysed in the form of small polished cores, derived from sulphido- and oxide-rich rocks, and from Ni-S-dominated fire assay beads. The chosen analytical strategies are shown to have essentially zero background for Au, Ag, and the PGE, with the notable result that detection limits, like precision, are limited only by the time available for analysis. Sensitivities for monatomic negative ions are in the order Au ≈ Ag > Pt ≈ Rh > Pd ≈ Ir > Ru > Os, with nominal detection limits (quoted on the basis of equal counting times of 100 sec) ranging from 0.1 ppb for Au to <600 ppb for Os. The utility of the method is exemplified in terms of analysis of specific sulphidic precious-metal ores. Although optical and Scanning Electron Microscope (SEM) studies reveal substantial heterogeneities in the NiS beads, on scales varying from 1 μm to 100 μm, reproducible results to a precision of < 10% can be obtained because the probing beam of Cs, ≈ 500 μm in diameter, averages out these inhomogeneities, but still has the spatial resolution to provide grain-by-grain analysis of coarse ore samples. The magnitudes of PGE partition coefficients between the sulphido components of the beads, which await determination with a collimated probing beam, provide a limiting factor in the attainable precision of the results. These samples have become the reference material of choice for precious metal analysis within this laboratory. The technique permits direct measurement of the partitioning of precious metals between coexisting ore minerals, and of PGE patterns within single crystals of such phases as pyrite and chromite.

  11. Mathematical model of gamma-ray spectrometry borehole logging for quantitative analysis

    USGS Publications Warehouse

    Schimschal, Ulrich

    1981-01-01

    A technique for analyzing gamma-ray spectral-logging data has been developed, in which a digital computer is used to calculate the effects of gamma-ray attentuation in a borehole environment. The computer model allows for the calculation of the effects of lithology, porosity, density, and the thickness of a horizontal layer of uniformly distributed radioactive material surrounding a centralized probe in a cylindrical borehole. The computer program also contains parameters for the calculation of the effects of well casing, drilling fluid, probe housing, and losses through the sodium-iodide crystal. Errors associated with the commonly used mathematical assumption of a point detector are eliminated in this model. (USGS)

  12. Calculation of the decision threshold in gamma-ray spectrometry using sum peaks.

    PubMed

    Korun, M; Vodenik, B; Zorko, B

    2016-03-01

    In the presence of radon daughters, gamma rays from (88)Y with energies at 898.0keV or 1836.1keV appear on a high, continuous background or overlap with other peaks. Therefore a calculation of the decision threshold from the sum peak at 2734.1keV represents a useful alternative, because here the continuous background is low. The decision threshold calculated from this peak can attain a value being comparable to the decision threshold calculated from the gamma-ray peak at 898.0keV. PMID:26625726

  13. Development of a Method for the Quantitation of Three Thiols in Beer, Hop, and Wort Samples by Stir Bar Sorptive Extraction with in Situ Derivatization and Thermal Desorption-Gas Chromatography-Tandem Mass Spectrometry.

    PubMed

    Ochiai, Nobuo; Sasamoto, Kikuo; Kishimoto, Toru

    2015-08-01

    A method for analysis of hop-derived polyfunctional thiols, such as 4-sulfanyl-4-methylpentan-2-one (4S4M2Pone), 3-sulfanylhexan-1-ol (3SHol), and 3-sulfanylhexyl acetate (3SHA), in beer, hop water extract, and wort at nanogram per liter levels was developed. The method employed stir bar sorptive extraction with in situ derivatization (der-SBSE) using ethyl propiolate (ETP), followed by thermal desorption and gas chromatography-tandem mass spectrometry (TD-GC-MS/MS) with selected reaction monitoring (SRM) mode. A prior step involved structural identification of the ETP derivatives of the thiols by TD-GC-quadrupole-time-of-flight mass spectrometry with parallel sulfur chemiluminescence detection (Q-TOF-MS/SCD) after similar der-SBSE. The der-SBSE conditions of the ETP concentration, buffer concentration, salt addition, and extraction time profiles were investigated, and the performance of the method was demonstrated with spiked beer samples. The limits of detection (LODs) (0.19-27 ng/L) are below the odor threshold levels of all analytes. The apparent recoveries at 10-100 ng/L (99-101%) and the repeatabilities [relative standard deviation (RSD) of 1.3-7.2%; n = 6] are also good. The method was successfully applied to the determination of target thiols at nanogram per liter levels in three kinds of beer samples (hopped with Cascade, Citra, and Nelson Sauvin) and the corresponding hop water extracts and wort samples. There was a clear correlation between the determined values and the characteristics of citrus hop aroma for each sample. PMID:26166150

  14. Infrared spectra of U.S. automobile original finishes (post - 1989). VIII: In situ identification of bismuth vanadate using extended range FT-IR spectroscopy, Raman spectroscopy, and X-ray fluorescence spectrometry.

    PubMed

    Suzuki, Edward M

    2014-03-01

    Chrome Yellow (PbCrO4 ·xPbSO4 ) was a common pigment in U.S. automobile OEM finishes for more than three decades, but in the early 1990s its use was discontinued. One of its main replacements was Bismuth Vanadate (BiVO4 ·nBi2 MoO6 , n = 0-2), which was commercially introduced in 1985, as this inorganic pigment also produces a very bright hue and has excellent outdoor durability. This paper describes the in situ identification of Bismuth Vanadate in automotive finishes using FT-IR and dispersive Raman spectroscopy and XRF spectrometry. Some differentiation of commercial formulations of this pigment is possible based on far-infrared absorptions, Raman data, and elemental analysis. The spectral differences arise from the presence or absence of molybdenum, the use of two crystal polymorphs of BiVO4 , and differences in pigment stabilizers. Bismuth Vanadate is usually not used alone, and it is typically found with Isoindoline Yellow, hydrous ferric oxide, rutile, Isoindolinone Yellow 3R, or various combinations of these. PMID:24261821

  15. Hollow fiber liquid-phase microextraction with in situ derivatization combined with gas chromatography-mass spectrometry for the determination of root exudate phenylamine compounds in hot pepper ( Capsicum annuum L.).

    PubMed

    Sun, Haiyan; Wang, Yan

    2013-06-12

    Hollow fiber liquid-phase microextraction (HF-LPME) with derivatization was developed for the determination of three root exudate phenylamine compounds in hot pepper ( Capsicum annuum L.) by gas chromatography-mass spectrometry (GC-MS). The performance and applicability of the proposed procedure were evaluated through the extraction of 1-naphthylamine (1-NA), diphenylamine (DPA), and N-phenyl-2- naphthaleneamine (N-P-2-NA) in a recirculating hydroponic solution of hot pepper. Parameters affecting the extraction efficiency were investigated. The calibration curves showed a good linearity in the range of 0.1-10 ?g mL(-1). The limits of detection (S/N = 3) for the three compounds were 0.096, 0.074, and 0.057 ?g mL(-1), respectively. The enrichment factors reached 174, 196, and 230 at the concentration of 5 ?g mL(-1), and relative standard deviations (RSD) of 9.5, 8.6, and 7.8% and 8.4, 7.6, and 6.2% were obtained at concentrations of 2 and 5 ?g mL(-1) for 1-NA, DPA, and N-P-2-NA, respectively. Recoveries ranging from 90.2 to 96.1% and RSDs below 9.1% were obtained when HF-LPME with in situ derivatization was applied to determine root exudate 1-NA, DPA, and N-P-2-NA after 15 and 30 days of culture solution, respectively. PMID:23706116

  16. An efficiency calibration for 210Pb and 7Be measurements by gamma-ray spectrometry in atmospheric filters

    NASA Astrophysics Data System (ADS)

    Martnez-Ruiz, F.; Borrego, E.; San Miguel, E. G.; Bolvar, J. P.

    2007-09-01

    Natural radionuclides, especially 210Pb and 7Be, condensed on suspended particulate matter in the atmosphere (commonly called aerosols) have been widely used to study a large variety of relevant atmospheric processes. A rapid and non-destructive analysis of 210Pb and 7Be is possible by direct measurement of their 46.5 and 477.6 keV ?-rays, respectively. In this work we have developed an original method to find an empirical function which relates the full-energy peak efficiency with energy in a rectangular geometry for energies above 150 keV. For the energy range below 150 keV only the 46.5 keV of the gamma photon of 210Pb was of interest in this work. A dusty Reference Material (phosphate rock) containing high levels of 238U-series radionuclides, especially 226Ra, was used as calibration sample. This solid matrix (grain size smaller than 63 ?m) was taken to impregnate homogenously the filters so that the real geometry of measurement was reproduced. 210Pb and 7Be activity concentrations in surface air were determined in samples collected from July 2004 to June 2005 at three different locations of the Huelva province (South West of Spain): urban, rural, and industrialized areas. 7Be and 210Pb activities have been determined in the PM 10 and TSP fractions of surface aerosols. The radiometric measurements were performed by low-level gamma spectrometry with a thin window coaxial germanium detector.

  17. The Application of High-Resolution Gamma-Ray Spectrometry (HRGS) to Nuclear Safeguards, Nonproliferation, and Arms Control Activities

    SciTech Connect

    Kane, Walter R.; Lemley, James R.; Forman, Leon

    1997-12-31

    While well-developed methodologies exist for the employment of high- resolution gamma ray spectrometry (HRGS) in determining the isotopic composition of plutonium samples, the potential capabilities of such measurements in determining the properties of nuclear materials otherwise remain largely unexploited. These measurements contain information sufficiently detailed such that not only can the isotopic composition of uranium and plutonium materials be determined, but the details of the spectrum obtained will depend reproducibly upon other factors including the total mass, density, chemical composition, and geometrical configuration of the material, and for certain materials, the elapsed time since chemical processing. The potential thus exists to obtain a `gamma-ray fingerprint` for typical containers or assemblies of nuclear material which will then serve to identify that class of item in a later confirmatory measurement. These measurements have the additional advantage that, by comparison with active interrogation techniques which usually require the introduction of some extraneous form of radiation or other intrusive activity, they are totally passive, and thus impose only minimal additional safety or regulatory burdens on the operators. In the application of these measurements to the verification of treaty-limited items, where the information acquired may be sensitive in nature, the use of the CIVET (Controlled Intrusiveness Verification Technique) approach, where a computer-based interface is employed to limit access to the information obtained, may be followed.

  18. Prospecting for Lunar Oxygen with Gamma-Ray Spectrometry and Multispectral Imaging

    NASA Technical Reports Server (NTRS)

    Allen, Carlton C.; Weitz, Catherine M.; McKay, David S.

    1998-01-01

    Oxygen is a potentially abundant lunar resource that could be used for life support and spacecraft propulsion. The recent identification by Prospector of ice at the lunar poles has renewed interest in the use of in situ 0 production to supply a future base. Siting a lunar base at any significant distance from the poles, however, would require costly transport of 0 or its extraction from the local regolith. More than 20 different processes have been proposed for regolith 0 extraction. Among the simplest and best studied of these processes is the reduction of oxides in lunar minerals and glass using H gas. Oxides, predominantly those containing FeO, are first reduced; 0 is then liberated to form water. The water is then electrolyzed to yield 0, and the H is recycled to the reactor.

  19. The Study of Equilibrium factor between Radon-222 and its Daughters in Bangkok Atmosphere by Gamma-ray Spectrometry

    NASA Astrophysics Data System (ADS)

    Rujiwarodom, Rachanee

    2010-05-01

    To study the Equilibrium between radon-222 and its daughters in Bangkok atmosphere by Gamma-ray spectrometry, air sample were collected on 48 activated charcoal canister and 360 glass fiber filters by using a high volume jet-air sampler during December 2007 to November 2008.The Spectra of gamma-ray were measured by using a HPGe (Hyper Pure Germanium Detector). In the condition of secular equilibrium obtaining between Radon-222 and its decay products, radon-222 on activated charcoal canister and its daughters on glass fiber filters collected in the same time interval were calculated. The equilibrium factor (F) in the open air had a value of 0.38 at the minimum ,and 0.75 at the maximum. The average value of equilibrium factor (F) was 0.560.12. Based on the results, F had variations with a maximum value in the night to the early morning and decreased in the afternoon. In addition, F was higher in the winter than in the summer. This finding corresponds with the properties of the Earth atmosphere. The equilibrium factor (F) also depended on the concentration of dust in the atmosphere. People living in Bangkok were exposed to average value of 30 Bq/m3 of Radon-222 in the atmosphere. The equilibrium factor (0.560.12) and the average value of Radon-222 showed that people were exposed to alpha energy from radon-222 and its daughters decay at 0.005 WL(Working Level) which is lower than the safety standard at 0.02 WL. Keywords: Radon, Radon daughters , equilibrium factor, Gamma -ray spectrum analysis ,Bangkok ,Thailand

  20. Measurement of gamma radiation levels in soil samples from Thanjavur using γ-ray spectrometry and estimation of population exposure

    PubMed Central

    Senthilkumar, B.; Dhavamani, V.; Ramkumar, S.; Philominathan, P.

    2010-01-01

    This study assesses the level of terrestrial gamma radiation and associated dose rates from the naturally occurring radionuclides 232Th, 238U and 40K in 10 soil samples collected from Thanjavur (Tamil Nadu, India) using γ-ray spectrometry. The activity profile of radionuclides has clearly showed the existence of low level activity in Thanjavur. The geometric mean activity concentrations of 232Th, 238U and 40K is 42.9±9.4 Bq.kg−1, 14.7±1.7 Bq.kg−1 and 149.5±3.1 Bq.kg−1 respectively are derived from all the soil samples studied. The activity concentration of 232Th, 238U and 40K in soil is due to the presence of metamorphic rocks like shale, hornblende-biotite gneiss and quartzofeldspathic gneiss in these areas. Gamma absorbed dose rates in air outdoors were calculated to be in the range between 32 nGy.h−1 and 59.1 nGy.h−1 with an arithmetic mean of 43.3 ±9 nGy.h−1. This value is lesser than the population weighted world-averaged of 60 nGy.h−1. Inhabitants of Thanjavur are subjected to external gamma radiation exposure (effective dose) ranging between 39.2 and 72.6 μSv.y−1 with an arithmetic mean of 53.1±11 μSv.y−1. The values of the external hazard index determined from the soil radioactivity of the study area are less than the recommended safe levels. PMID:20177570

  1. The efficiency calibration and development of environmental correction factors for an in situ high-resolution gamma spectroscopy well logging system

    SciTech Connect

    Giles, J.R.

    1996-05-01

    A Gamma Spectroscopy Logging System (GSLS) has been developed to study sub-surface radionuclide contamination. Absolute efficiency calibration of the GSLS was performed using simple cylindrical borehole geometry. The calibration source incorporated naturally occurring radioactive material (NORM) that emitted photons ranging from 186-keV to 2,614-keV. More complex borehole geometries were modeled using commercially available shielding software. A linear relationship was found between increasing source thickness and relative photon fluence rates at the detector. Examination of varying porosity and moisture content showed that as porosity increases, relative photon fluence rates increase linearly for all energies. Attenuation effects due to iron, water, PVC, and concrete cylindrical shields were found to agree with previous studies. Regression analyses produced energy-dependent equations for efficiency corrections applicable to spectral gamma-ray well logs collected under non-standard borehole conditions.

  2. Characterisation of imperial college reactor centre legacy waste using gamma-ray spectrometry

    NASA Astrophysics Data System (ADS)

    Shuhaimi, Alif Imran Mohd

    2016-01-01

    Waste characterisation is a principal component in waste management strategy. The characterisation includes identification of chemical, physical and radiochemical parameters of radioactive waste. Failure to determine specific waste properties may result in sentencing waste packages which are not compliant with the regulation of long term storage or disposal. This project involved measurement of intensity and energy of gamma photons which may be emitted by radioactive waste generated during decommissioning of Imperial College Reactor Centre (ICRC). The measurement will use High Purity Germanium (HPGe) as Gamma-ray detector and ISOTOPIC-32 V4.1 as analyser. In order to ensure the measurements provide reliable results, two quality control (QC) measurements using difference matrices have been conducted. The results from QC measurements were used to determine the accuracy of the ISOTOPIC software.

  3. Gamma ray spectrometry logs as a hydrocarbon indicator for clastic reservoir rocks in Egypt.

    PubMed

    Al-Alfy, I M; Nabih, M A; Eysa, E A

    2013-03-01

    Petroleum oil is an important source for the energy in the world. The Gulf of Suez, Nile Delta and South Valley are important regions for studying hydrocarbon potential in Egypt. A thorium normalization technique was applied on the sandstone reservoirs in the three regions to determine the hydrocarbon potentialities zones using the three spectrometric radioactive gamma ray-logs (eU, eTh and K% logs). The conventional well logs (gamma-ray, deep resistivity, shallow resistivity, neutron, density and sonic logs) are analyzed to determine the net pay zones in these wells. Indices derived from thorium normalized spectral logs indicate the hydrocarbon zones in petroleum reservoirs. The results of this technique in the three regions (Gulf of Suez, Nile Delta and South Valley) are in agreement with the results of the conventional well log analyses by ratios of 82%, 78% and 71% respectively. PMID:23306160

  4. Quantifying the benefits of ultrahigh energy resolution for gamma-ray spectrometry

    NASA Astrophysics Data System (ADS)

    Drury, Owen B.; Terracol, Stephane F.; Friedrich, Stephan

    2005-03-01

    Cryogenic Gamma-ray spectrometers operating at temperatures of 0.1 K provide an order of magnitude better energy resolution than conventional germanium detectors. Ultra-high energy resolution improves the accuracy of non-destructive analysis of nuclear materials, since a better separation of lines reduces statistical errors as well as systematic errors from background subtraction and efficiency correction. We are developing cryogenic Gamma-spectrometers based on bulk tin absorbers and superconducting molybdenum-copper sensors for nuclear forensics and non-proliferation applications. Here we quantify the improvements in accuracy for isotope analysis with cryogenic detectors in terms of detector performance for different cases of line separation, line intensity ratios and background levels. Precise measurements of isotope ratios are crucial in the context of nuclear attribution, since they provide signatures of composition, age, origin, intended purpose and processing history of illicit nuclear materials.

  5. Elemental analysis of a comet nucleus by passive gamma ray spectrometry from a penetrator

    NASA Technical Reports Server (NTRS)

    Evans, L. G.; Trombka, J. I.; Boynton, W. V.

    1986-01-01

    The Comet Rendezvous Asteroid Flyby (CRAF) spacecraft, to be launched in 1991, was designed to study the physical and chemical properties of cometary and asteroid bodies. It is proposed that these properties can be determined by utilizing a penetrator experiment delivery system aboard the CRAF, which would deliver a passive gamma ray spectrometer to the comet and determine the composition of subsurface materials. Results of calculations for a model comet (50 percent CI carbonaceous chrondrite, 50 percent ices) provide data on the expected gamma ray fluxes, the minimum detectable limits, and the detection uncertainties for 35 isotopes. These results confirm that this technique can determine the composition of both the rocky and ice components, and the rock-to-ice ratio in the nucleus. In addition, useful information regarding the formation of the solar system is provided.

  6. Monte Carlo Solutions for Selected Problems in Gamma-Ray Spectrometry and Nuclear Activation Analysis

    SciTech Connect

    Sima, Octavian

    2008-08-14

    A comprehensive calibration of gamma-ray spectrometers cannot be obtained purely on experimental basis. Problems like self-attenuation effects, coincidence-summing effects and non-uniform source distribution (resulting e.g. from neutron self-shielding in NAA) can be efficiently solved by Monte Carlo simulation. The application of the GESPECOR code to these problems is presented and the associated uncertainty is discussed.

  7. Fission Fragment Studies by Gamma-Ray Spectrometry with the Mass Separator Lohengrin

    NASA Astrophysics Data System (ADS)

    Materna, T.; Amouroux, C.; Bail, A.; Bideau, A.; Chabod, S.; Faust, H.; Capellan, N.; Kessedjian, G.; Kster, U.; Letourneau, A.; Litaize, O.; Martin, F.; Mathieu, L.; Mplan, O.; Panebianco, S.; Rgis, J.-M.; Rudigier, M.; Sage, C.; Serot, O.; Urban, W.

    2014-09-01

    A gamma spectrometric technique was implemented at the exit of the fission fragment separator of the ILL. It allows a precise measurement of isotopic yields of most important actinides in the heavy fragment region by an unambiguous identification of the nuclear charge of the fragments selected by the mass spectrometer. The status of the project and last results are reviewed. A spin-off of this activity is the identification of unknown nanosecond isomers in exotic nuclei through the observation of a disturbed ionic charge distribution. This technique has been improved to provide an estimation of the lifetime of the isomeric state.

  8. Uncertainty assessment in the free release measurement by gamma spectrometry of rotating waste drums.

    PubMed

    Stanga, D; Sima, O; Gurau, D

    2016-03-01

    The assessment of uncertainty in free release measurements by integral gamma scanning method is described and applied to the measurement of homogeneous and heterogeneous waste drums. It is based on the propagation of distributions using the Monte Carlo method. In addition, two techniques for the uncertainty reduction are also described. The first technique makes use of containers constructed from two concentric cylinders and the second technique is based on the measurement of a group of waste drums. It is proved that the uncertainty of clearance measurements can be reduced using both techniques. PMID:26653210

  9. Modern aerial gamma-ray spectrometry and regional potassium map of the conterminous United States

    USGS Publications Warehouse

    Duval, Joseph S.

    1990-01-01

    The aerial gamma-ray data were obtained as part of the National Uranium Resource Evaluation (NURE) Program sponsored by the U.S. Department of Energy during the period 1975-1983. References for the Open-File Reports that describe the surveys and data collection can be found in Bendix Field Engineering Corp. (1983). The aerial surveys were flown by contractors using fixed-wing and helicopter systems with 33-50 L (liters) of thallium-activated sodium iodide (NaI (TI)) crystals. The nominal survey altitude used is 122 m. The survey lines were generally east-west with line spacings of 1.6-10 km. Tie lines were flown perpendicular to the flight lines at intervals of 16- 30 km. The data were corrected for background from aircraft contamination and cosmic rays, altitude variations, airborne 214Bi, and Compton scattering. The gamma-ray systems were calibrated using the calibrations pads at Grand Junction, Colorado (Ward, 1978 ) and the dynamic test strip at Lake Mead, Arizona (Geodata International, Inc., 1977).  

  10. Spectral information enhancement using wavelet-based iterative filtering for in vivo gamma spectrometry.

    PubMed

    Paul, Sabyasachi; Sarkar, P K

    2013-04-01

    Use of wavelet transformation in stationary signal processing has been demonstrated for denoising the measured spectra and characterisation of radionuclides in the in vivo monitoring analysis, where difficulties arise due to very low activity level to be estimated in biological systems. The large statistical fluctuations often make the identification of characteristic gammas from radionuclides highly uncertain, particularly when interferences from progenies are also present. A new wavelet-based noise filtering methodology has been developed for better detection of gamma peaks in noisy data. This sequential, iterative filtering method uses the wavelet multi-resolution approach for noise rejection and an inverse transform after soft 'thresholding' over the generated coefficients. Analyses of in vivo monitoring data of (235)U and (238)U were carried out using this method without disturbing the peak position and amplitude while achieving a 3-fold improvement in the signal-to-noise ratio, compared with the original measured spectrum. When compared with other data-filtering techniques, the wavelet-based method shows the best results. PMID:22887117

  11. Rapid Discrimination of Haemophilus influenzae, H. parainfluenzae, and H. haemolyticus by Fluorescence In Situ Hybridization (FISH) and Two Matrix-Assisted Laser-Desorption-Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF-MS) Platforms

    PubMed Central

    Frickmann, Hagen; Christner, Martin; Donat, Martina; Berger, Anja; Essig, Andreas; Podbielski, Andreas; Hagen, Ralf Matthias; Poppert, Sven

    2013-01-01

    Background Due to considerable differences in pathogenicity, Haemophilus influenzae, H. parainfluenzae and H. haemolyticus have to be reliably discriminated in routine diagnostics. Retrospective analyses suggest frequent misidentifications of commensal H. haemolyticus as H. influenzae. In a multi-center approach, we assessed the suitability of fluorescence in situ hybridization (FISH) and matrix-assisted laser-desorption-ionization time-of-flight mass-spectrometry (MALDI-TOF-MS) for the identification of H. influenzae, H. parainfluenzae and H. haemolyticus to species level. Methodology A strain collection of 84 Haemophilus spp. comprising 50 H. influenzae, 25 H. parainfluenzae, 7 H. haemolyticus, and 2 H. parahaemolyticus including 77 clinical isolates was analyzed by FISH with newly designed DNA probes, and two different MALDI-TOF-MS systems (Bruker, Shimadzu) with and without prior formic acid extraction. Principal Findings Among the 84 Haemophilus strains analyzed, FISH led to 71 correct results (85%), 13 uninterpretable results (15%), and no misidentifications. Shimadzu MALDI-TOF-MS resulted in 59 correct identifications (70%), 19 uninterpretable results (23%), and 6 misidentifications (7%), using colony material applied directly. Bruker MALDI-TOF-MS with prior formic acid extraction led to 74 correct results (88%), 4 uninterpretable results (5%) and 6 misidentifications (7%). The Bruker MALDI-TOF-MS misidentifications could be resolved by the addition of a suitable H. haemolyticus reference spectrum to the system's database. In conclusion, no analyzed diagnostic procedure was free of errors. Diagnostic results have to be interpreted carefully and alternative tests should be applied in case of ambiguous test results on isolates from seriously ill patients. PMID:23646201

  12. 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 (?-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 ?-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 ?-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 ?-probe analysis reveals different patterns and behaviors for nicotine, and a range of semi-volatile aromatic and aliphatic species. PMID:22244143

  13. Investigation of the automated determination of As, Sb and Bi by flow-injection hydride generation using in-situ trapping on stable coatings in graphite furnace atomic absorption spectrometry.

    PubMed

    Haug, H O; Liao, Y P

    1996-12-01

    Flow-injection hydride generation and in situ concentration of As, Sb and Bi hydrides in graphite furnace atomic absorption spectrometry can be automated by means of a long-term stable trapping reagent replacing the Pd modifier. In a systematic study, carbide-forming elements (Zr, Nb, Ta, W) and noble metals (Ir, Ir/Mg, Pd/Ir) were investigated as stable adsorbers which require only a single application. Trapping temperature curves indicate high signals for trapping of As at 750-800 degrees C, Sb at 450-8000 degrees C and Bi at 100-500 degrees C on Zr-coated tubes. Ir- and Ir/Mg-coated tubes showed a high response for Sb and Bi at lower temperatures, but based on signal stability and reproducibility (over 400 trapping and atomization cycles tested) the better performance was found with the Zr-coated tubes. The radiotracers Sb-125 and Bi-207 were used to measure the hydride generation (>95% for both elements) and trapping efficiency (91% for Sb and 56% for Bi) on the Zr-coated tube. An adsorptive "carry-over effect" was observed with Sb and Bi but not with As, and trapping temperatures above 450 degrees C with Sb and 350 degrees C with Bi (the "critical temperatures") can lead to errors in absorbance values. On a Zr-coated tube the characteristic mass was about 16 pg for As, 15 pg for Sb and 9 pg for Bi (peak height) and the detection limits (3 sigma) were about 0.015, 0.010 and 0.027 ng, respectively, with a 1 ml sample loop. The method was tested by the determination of the elements in NIST low-alloy steel certified reference materials. PMID:15045225

  14. Comparison of peptide nucleic acid fluorescence in situ hybridization assays with culture-based matrix-assisted laser desorption/ionization-time of flight mass spectrometry for the identification of bacteria and yeasts from blood cultures and cerebrospinal fluid cultures.

    PubMed

    Calderaro, A; Martinelli, M; Motta, F; Larini, S; Arcangeletti, M C; Medici, M C; Chezzi, C; De Conto, F

    2014-08-01

    Peptide nucleic acid fluorescence in situ hybridization (PNA FISH) is a molecular diagnostic tool for the rapid detection of pathogens directly from liquid media. The aim of this study was to prospectively evaluate PNA FISH assays in comparison with culture-based matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) identification, as a reference method, for both blood and cerebrospinal fluid (CSF) cultures, during a 1-year investigation. On the basis of the Gram stain microscopy results, four different PNA FISH commercially available assays were used ('Staphylococcus aureus/CNS', 'Enterococcus faecalis/OE', 'GNR Traffic Light' and 'Yeasts Traffic Light' PNA FISH assays, AdvanDx). The four PNA FISH assays were applied to 956 positive blood cultures (921 for bacteria and 35 for yeasts) and 11 CSF cultures. Among the 921 blood samples positive for bacteria, PNA FISH gave concordant results with MALDI-TOF MS in 908/921 (98.64%) samples, showing an agreement of 99.4% in the case of monomicrobial infections. As regards yeasts, the PNA FISH assay showed a 100% agreement with the result obtained by MALDI-TOF MS. When PNA FISH assays were tested on the 11 CSF cultures, the results agreed with the reference method in all cases (100%). PNA FISH assays provided species identification at least one work-day before the MALDI-TOF MS culture-based identification. PNA FISH assays showed an excellent efficacy in the prompt identification of main pathogens, yielding a significant reduction in reporting time and leading to more appropriate patient management and therapy in cases of sepsis and severe infections. PMID:24304149

  15. Radiometric analysis of construction materials using HPGe gamma-ray spectrometry.

    PubMed

    Khandaker, M U; Jojo, P J; Kassim, H A; Amin, Y M

    2012-11-01

    Concentrations of primordial radionuclides in common construction materials collected from the south-west coastal region of India were determined using a high-purity germanium gamma-ray spectrometer. Average specific activities (Bq kg(-1)) for (238)U((226)Ra) in cement, brick, soil and stone samples were obtained as 54 13, 21 4, 50 12 and 46 8, respectively. Respective values of (232)Th were obtained as 65 10, 21 3, 58 10 and 57 12. Concentrations of (40)K radionuclide in cement, brick, soil and stone samples were found to be 440 91, 290 20, 380 61 and 432 64, respectively. To evaluate the radiological hazards, radium equivalent activity, various hazard indices, absorbed dose rate and annual effective dose have been calculated, and compared with the literature values. Obtained data could be used as reference information to assess any radiological contamination due to construction materials in future. PMID:22887119

  16. Detection of frozen salt in pipes using gamma-ray spectrometry of potassium self-activity

    SciTech Connect

    Grena, Roberto; Scafe, Raffaele; Pisacane, Fabrizio; Pilato, Renzo; Crescenzi, Tommaso; Mazzei, Domenico

    2010-01-15

    Solar plants that use molten salts as heat transfer fluid need careful control to avoid the freezing of the salt in the pipes; if such a problem occurs, a diagnostic instrument to localize where is the frozen salt plug and to determine its length is useful. If the salt contains potassium (as is the case of the most common mixture used in solar plants, NaNO{sub 3}/KNO{sub 3} 60/40% by weight), the gamma decay of the natural unstable isotope {sup 40}K can be exploited to detect the frozen salt in a non-invasive way. Simulations and experimental results regarding the detectability of such plugs with different masses/lengths are presented. (author)

  17. Contribution of {sup 137}Cs to the total absorbed gamma dose rate in air in a Greek forest ecosystem: Measurements and Monte Carlo computations

    SciTech Connect

    Clouvas, A.; Xanthos, S.; Antonopoulos-Domis, M.; Alifragis, D.A.

    1999-01-01

    The absorbed gamma dose rate in air 1 m above soil due to natural gamma emitters and {sup 137}Cs from the Chernobyl accident was determined inside a Quercus conferta Kit ecosystem in Northern Greece by combination of Monte Carlo simulations with the MNP code and in-situ gamma spectrometry measurements. The total absorbed gamma dose rate in air is about 64 nGy h{sup {minus}1}, where 40% of this value is due to {sup 137}Cs and 60% to natural gamma emitters. The Monte Carlo simulations indicated that the gamma absorbed dose rate in air due to {sup 137}Cs is mainly due (70%) to unscattered radiation and to a lesser extent (30%) to the scattered radiation. The results obtained with the Monte Carlo simulations for the unscattered radiation were in very good agreement with the experimental values deduced by in-situ gamma spectrometry measurements. From the combination of the Monte Carlo simulations and in-situ gamma spectrometry measurements a conversion factor C = 1 nGy h{sup {minus}1}/kBq m{sup {minus}2} was deduced for {sup 137}Cs. This factor must be used with caution and only for forest sites similar to the one used for this work.

  18. Contribution of 137Cs to the total absorbed gamma dose rate in air in a Greek forest ecosystem: measurements and Monte Carlo computations.

    PubMed

    Clouvas, A; Xanthos, S; Antonopoulos-Domis, M; Alifragis, D A

    1999-01-01

    The absorbed gamma dose rate in air 1 m above soil due to natural gamma emitters and 137Cs from the Chernobyl accident was determined inside a Quercus conferta Kit ecosystem in Northern Greece by combination of Monte Carlo simulations with the MCNP code and in-situ gamma spectrometry measurements. The total absorbed gamma dose rate in air is about 64 nGy h(-1), where 40% of this value is due to 137Cs and 60% to natural gamma emitters. The Monte Carlo simulations indicated that the gamma absorbed dose rate in air due to 137Cs is mainly due (70%) to unscattered radiation and to a lesser extent (30%) to the scattered radiation. The results obtained with the Monte Carlo simulations for the unscattered radiation were in very good agreement with the experimental values deduced by in-situ gamma spectrometry measurements. From the combination of the Monte Carlo simulations and in-situ gamma spectrometry measurements a conversion factor C = 1 nGy h(-1)/kBq m(-2) was deduced for 137Cs. This factor must be used with caution and only for forest sites similar to the one used for this work. PMID:9883945

  19. In-Situ Spectrometry of Neutrons

    NASA Technical Reports Server (NTRS)

    Maurer, Richard H.

    1999-01-01

    High energy charged particles of extra-galactic, galactic and solar origin collide with spacecraft structures in Earth orbit outside the atmosphere and in interplanetary travel beyond the Earth's magnetosphere. These primaries create a number of secondary particles inside the structures that can produce a significant ionizing radiation environment. This radiation is a threat to long term inhabitants or travelers for space missions and produces an increased risk of cancer and DNA damage. The primary high energy cosmic rays and trapped protons collide with common spacecraft materials such as aluminum and silicon and create secondary particles inside structures that are mostly protons and neutrons. Charged protons are readily detected and instruments are already in existence for this task. Neutrons are electrically neutral and therefore much more difficult to measure and detect. These neutrons are reported to contribute 30-60% of the dose inside space structures and cannot be ignored. Currently there is no compact, portable and real time neutron detector instrumentation available for use inside spacecraft or on planetary surfaces where astronauts will live and work. We propose to design and build a portable, low power and robust neutron spectrometer that will measure the neutron spectrum from 10 KeV to 500 MeV with at least 10% energy resolution in the various energy intervals. This instrument will monitor the existing neutron environment both inside spacecraft structures and on planetary surfaces to determine the safest living areas, warn of high fluxes associated with solar storms and assist the NSBRI Radiation Effects Team in making an accurate assessment of increased cancer risk and DNA damage to astronauts. The instrument uses a highly efficient proportional counter Helium 3 tube at the lowest energy intervals where .equivalent damage factors for tissue are the highest (10 KeV-2 MeV). The Helium 3 tube may be shielded with a cadmium absorber to eliminate the much less damaging, but more prevalent, thermal and epithermal neutrons and to make the structure of the spectrum more accurate in the 20 KeV-2 MeV range; or a pair of tubes, one shielded and one unshielded, can be combined so that the difference in their counts yields the thermal neutron contribution. The spectrometer also uses a 5mm lithium drifted bulk silicon solid state detector in the medium energy range of 2-20 Mev and two standard silicon surface barrier detectors separated by tens of millimeters behind a I cm thick polyethylene moderator in a stack or telescope arrangement for the high energy neutrons (>20 MeV). In the medium and high energy regions equivalent damage factors are lower but hits from one or a small number of neutrons may prove to be important. The silicon detector systems for medium and high energy neutrons will discriminate against charged particles by using a plastic cesium iodide scintillator of an appropriate geometry monitored by a silicon PIN photodiode.

  20. The in situ exobiological investigation of the Martian surface mineralogy during unmanned missions. [Abstract only

    NASA Technical Reports Server (NTRS)

    Mancinelli, Rocco L.; White, Melisa R.

    1994-01-01

    An important goal of exobiological research is to determine if life arose on planets other than Earth. The only other planet known, to date, on which life may have arisen is Mars. The data suggest that the physical environment of early Mars (i.e., temperature, pressure, and radiation regimes) was suitable for life to arise. Thus far, the data also suggest that early Mars possessed sufficient quantities of the required building blocks and a number of the chemical compounds necessary for life to arise. It is not known, however, if water existed in the appropriate state (i.e., liquid) in sufficient quantities long enough for life to arise. Determining the mineralogy and components of the Martian soil through in situ analyses during missions to Mars will provide information from which an assessment can be made for the probability of the origin of life on Mars. Missions to Mars in the near future will be unmanned and capable of in situ analyses. Our studies have shown that differential thermal analysis coupled with gas chromatography (DTA/GC) is a more appropriate analytical technique than, x-ray fluorescence, x-ray diffraction, alpha-proton backscatter, gamma-ray spectrometry, differential scanning calorimetry coupled with mass spectrometry (DSC/MS), or DSC/GC to identify the mineralogy of the Martian surface material in situ. DTA/GC is an advancement over the pyrolytic techniques flown on previous missions that have supplied only limited mineralogical information (Biemann et al. 1977).

  1. Data acquisition ATCA system for neutron and gamma-rays spectrometries

    SciTech Connect

    Pereira, R.; Fernandes, A. G.; Sousa, J.; Varandas, C. A. F.

    2006-10-15

    Digital pulse processing (DPP) systems are known to have better performance than analog ones for neutron and/or gamma-ray pulses. DPP can synthesize almost any pulse response shape without the associated signal degradation which happens in a complex analog path. Measuring techniques involving detectors/spectrometers for fusion diagnostics rely on real-time algorithms, implemented in field programmable gate array (FPGA), for pulse height analysis, pulse shape discrimination, and pileup rejection of digitized pulses in real time for reduced data throughput, monitoring, and control. This article describes a data acquisition system for real-time pulse analysis based on ATCA and contains a 6 GFLPOS ix86-based control unit and a number of transient recorder (TR) modules interconnected through PCI Express links. Each TR module features (i) eight channels of 12 bit resolution with accuracy equal or higher than 10 bits, (ii) 200 Msamples/s of sampling rate achieving 400 Msamples/s in an interleaved architecture, (iii) 2 or 4 Gbytes of local memory, and (iv) two field FPGAs able to perform real-time processing algorithms.

  2. Data acquisition ATCA system for neutron and gamma-rays spectrometries

    NASA Astrophysics Data System (ADS)

    Pereira, R.; Fernandes, A. G.; Sousa, J.; Varandas, C. A. F.

    2006-10-01

    Digital pulse processing (DPP) systems are known to have better performance than analog ones for neutron and/or gamma-ray pulses. DPP can synthesize almost any pulse response shape without the associated signal degradation which happens in a complex analog path. Measuring techniques involving detectors/spectrometers for fusion diagnostics rely on real-time algorithms, implemented in field programmable gate array (FPGA), for pulse height analysis, pulse shape discrimination, and pileup rejection of digitized pulses in real time for reduced data throughput, monitoring, and control. This article describes a data acquisition system for real-time pulse analysis based on ATCA and contains a 6 GFLPOS i ×86-based control unit and a number of transient recorder (TR) modules interconnected through PCI Express links. Each TR module features (i) eight channels of 12bit resolution with accuracy equal or higher than 10bits, (ii) 200Msamples/s of sampling rate achieving 400Msamples/s in an interleaved architecture, (iii) 2 or 4Gbytes of local memory, and (iv) two field FPGAs able to perform real-time processing algorithms.

  3. Martian surface heat production and crustal heat flow from Mars Odyssey Gamma-Ray spectrometry

    NASA Astrophysics Data System (ADS)

    Hahn, B. C.; McLennan, S. M.; Klein, E. C.

    2011-07-01

    Martian thermal state and evolution depend principally on the radiogenic heat-producing element (HPE) distributions in the planet's crust and mantle. The Gamma-Ray Spectrometer (GRS) on the 2001 Mars Odyssey spacecraft has mapped the surface abundances of HPEs across Mars. From these data, we produce the first models of global and regional surface heat production and crustal heat flow. As previous studies have suggested that the crust is a repository for approximately 50% of the radiogenic elements on Mars, these models provide important, directly measurable constraints on Martian heat generation. Our calculations show considerable geographic and temporal variations in crustal heat flow, and demonstrate the existence of anomalous heat flow provinces. We calculate a present day average surface heat production of 4.9 0.3 10-11 W kg-1. We also calculate the average crustal component of heat flow of 6.4 0.4 mW m-2. The crustal component of radiogenically produced heat flow ranges from <1 mW m-2 in the Hellas Basin and Utopia Planitia regions to 13 mW m-2 in the Sirenum Fossae region. These heat production and crustal heat flow values from geochemical measurements support previous heat flow estimates produced by different methodologies.

  4. High Throughput In Situ EXAFS Instrumentation for the Automatic Characterization of Materials and Catalysts

    SciTech Connect

    Tsapatsaris, Nikolaos; Beesley, A. M.; Weiher, Norbert; Schroeder, Sven L. M.; Tromp, Moniek; Evans, John; Dent, A. J.; Harvey, Ian

    2007-01-19

    An XAS data acquisition and control system for the in situ analysis of dynamic materials libraries under control of temperature and gaseous environment has been developed. It was integrated at the SRS in Daresbury, UK, beamline 9.3, using a Si (220) monochromator and a 13 element solid state Ge fluorescence detector. The core of the system is an intelligent X, Y, Z, {theta} positioning system coupled to multi-stream quadrupole mass spectrometry analysis (QMS). The system is modular and can be adapted to other synchrotron radiation beamlines. The entire software control was implemented using Labview and allows the scan of a variety of library sizes, in several positions, angles, gas compositions and temperatures with minimal operator intervention. The system was used for the automated characterization of a library of 91 catalyst precursors containing ternary combinations of Cu, Pt, and Au on {gamma}-Al2O3, and for the evaluation and structural characterization of eight Au catalysts supported on Al2O3 and TiO2 Mass spectrometer traces reveal conversion rate oscillations in 6wt % Au/{gamma}Al2O3 catalysts. The use of HT experimentation for in situ EXAFS studies demonstrates the feasibility and potential of HT in situ XAFS for synchrotron radiation studies.

  5. In-situ soil carbon analysis using inelastic neutron scattering

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In situ soil carbon analysis using inelastic neutron scattering (INS) is based on the emission of 4.43 MeV gamma rays from carbon nuclei excited by fast neutrons. This in-situ method has excellent potential for easily measuring soil carbon since it does not require soil core sampling and processing ...

  6. Implications of Martian Surface Composition Determined by Mars Odyssey Gamma-Ray Spectrometry

    NASA Astrophysics Data System (ADS)

    Taylor, G. J.

    2006-12-01

    The Mars Odyssey spacecraft carries a gamma-ray spectrometer (GRS) that allows measurement of several elements (K, Th, Fe, Si, Al, Ca, Cl, and H) on the surface of Mars. Although its spatial resolution is 500 km, it measures the composition in the upper few tens of centimeters (compared to microns to a few hundred microns for reflectance or emission spectral techniques). GRS provides the first global chemical perspective on the composition of the Martian surface, allowing us to assess the composition of the crust and, with judicious assumptions, the bulk silicate composition of the planet. The data also allow us to identify major geochemical provinces to understand the evolution of the crust and search for the effects of aqueous alteration. GRS data show that the Martian surface is chemically heterogeneous. Elemental concentrations vary across the surface, including variations within high-albedo areas that are presumably covered with dust. Fe concentrations are uniformly high, in accord with the compositions of Martian meteorites and most rock samples analyzed by landed instruments. K/Th is variable, but 95% of the surface has a weight ratio between 3000 and 7000. The mean (5300) is double that in terrestrial crustal rocks and in the bulk silicate Earth. These data indicate that bulk silicate Mars is enriched in moderately volatile elements and in FeO compared to Earth, suggesting that there was not extensive mixing throughout the inner solar system during planetary accretion. Cl varies substantially, with the highest values (0.8 wt%) in the region west of the Tharsis Montes. Surface Types (ST) 1 and 2 (identified from TES spectra) are indistinguishable in Si and Fe concentrations, but ST2 is enriched in K and Th by about 30% relative to ST1 (the K/Th ratio is similar in both regions). The combination of TES and GRS data suggests that ST2 is composed of a different suite of (probably) basaltic rocks than is ST1 and has been weathered. The H2O mass fraction (derived from the H content) in equatorial regions ranges from about 1.5 to 7 %, suggesting the presence of hydrous minerals. Variation in H2O and highly soluble Cl, coupled with some areas with anomalous K/Th, provide geochemical evidence for the role of aqueous alteration on Mars, although the generally uniform K/Th might indicate that wet periods were short.

  7. Subsurface In Situ Elemental Composition Measurements with PING

    NASA Technical Reports Server (NTRS)

    Parsons, Ann; McClanahan, Timothy; Bodnarik, Julia; Evans, Larry; Nowicki, Suzanne; Schweitzer, Jeffrey; Starr, Richard

    2013-01-01

    This paper describes the Probing In situ with Neutron and Gamma rays (PING) instrument, that can measure the subsurface elemental composition in situ for any rocky body in the solar system without the need for digging into the surface. PING consists of a Pulsed Neutron Generator (PNG), a gamma ray spectrometer and neutron detectors. Subsurface elements are stimulated by high-energy neutrons to emit gamma rays at characteristic energies. This paper will show how the detection of these gamma rays results in a measurement of elemental composition. Examples of the basalt to granite ratios for aluminum and silicon abundance are provided.

  8. Improvements on Low Level Activity Gamma Measurements and X-ray Spectrometry at the CEA-MADERE Measurement Platform

    NASA Astrophysics Data System (ADS)

    Sergeyeva, Victoria; Domergue, Christophe; Destouches, Christophe; Girard, Jean Michel; Philibert, Hervé; Bonora, Jonathan; Thiollay, Nicolas; Lyoussi, Abdallah

    2016-02-01

    The CEA MADERE platform (Measurement Applied to DosimEtry in REactors) is a part of the Instrumentation Sensors and Dosimetry Laboratory (LDCI). This facility is dedicated to the specific activity measurements of solid and radioactive samples using Gamma and X-ray spectrometry. MADERE is a high-performance facility devoted to neutron dosimetry for experimental programs performed in CEA and for the irradiation surveillance programmes of PWR vessels. The MADERE platform is engaged in a continuous improvement process. Recently, two High Efficiency diodes have been integrated to the MADERE platform in order to manage the accurate low level activity measurements (few Bq per sample). This new equipment provides a good level of efficiency over the energy range from 60 keV to 2 MeV. The background continuum is reduced due to the use of a Ultra Low Background (ULB) lead shielding. Relative and absolute X-ray measurement techniques have been improved in order to facilitate absolute rhodium activity measurement (Rh103m) on solid samples. Additional efforts have been made to increase the accuracy of the relative niobium (Nb93m) activity measurement technique. The way of setting up an absolute measurement method for niobium is under investigation. After a presentation of the MADERE's measurement devices, this paper focuses on the technological options taken into account for the design of high efficiency measurement devices. Then, studies performed on X-ray measurement techniques are presented. Some details about the calculation of uncertainties and correction factors are also mentioned. Finally, future research and development axes are exposed.

  9. In situ mapping of radionuclides in subsurface and surface soils: 1994 Summary report

    SciTech Connect

    Schilk, A.J.; Hubbard, C.W.; Knopf, M.A.; Abel, K.H.

    1995-04-01

    Uranium production and support facilities at several DOE sites occasionally caused local contamination of some surface and subsurface soils. The thorough cleanup of these sites is a major public concern and a high priority for the US Department of Energy, but before any effective remedial protocols can be established, the three-dimensional distributions of target contaminants must be characterized. Traditional means of measuring radionuclide activities in soil are cumbersome, expensive, time-consuming, and often do not accurately reflect conditions over very large areas. New technologies must be developed, or existing ones improved, to allow cheaper, faster, and safer characterization of radionuclides in soils at these sites. The Pacific Northwest Laboratory (PNL) was tasked with adapting, developing, and demonstrating technologies to measure uranium in surface and subsurface soils. In partial completion of this effort, PNL developed an improved in situ gamma-ray spectrometry system to satisfy the technical requirements. This document summarizes fiscal-year 1994 efforts at PNL to fulfill requirements for TTP {number_sign}321103 (project {number_sign}19307). These requirements included (a) developing a user-friendly software package for reducing field-acquired gamma-ray spectra, (b) constructing an improved data-acquisition hardware system for use with high-purity germanium detectors, (c) ensuring readiness to conduct field mapping exercises as specified by the sponsor, (d) evaluating the in situ gamma-ray spectrometer for the determination of uranium depth distribution, and (e) documenting these efforts.

  10. Building-up a code for the purpose of TRUE coincidence summing correction in gamma-ray spectrometry with EGS4

    NASA Astrophysics Data System (ADS)

    Celik, Necati; Altin, Duygu; Cevik, Ugur

    2015-10-01

    In the presented study, a code was created for the purpose of true coincidence summing (TCS) correction factors for 134Cs. The created code was implemented in EGS4 Monte Carlo simulation package. TCS factors were determined for nine different energies for different detector-source geometries. The calculated results were successfully validated by an empirical method using a point 134Cs radioactive source and a p-type HPGe detector having 55% relative efficiency. Although the code created gives TCS factors only for 134Cs, the technique presented can be used to obtain the factors for any radionuclide used in gamma-ray spectrometry.

  11. Gamma-ray spectrometry method used for radioactive waste drums characterization for final disposal at National Repository for Low and Intermediate Radioactive Waste--Baita, Romania.

    PubMed

    Done, L; Tugulan, L C; Dragolici, F; Alexandru, C

    2014-05-01

    The Radioactive Waste Management Department from IFIN-HH, Bucharest, performs the conditioning of the institutional radioactive waste in concrete matrix, in 200 l drums with concrete shield, for final disposal at DNDR - Baita, Bihor county, in an old exhausted uranium mine. This paper presents a gamma-ray spectrometry method for the characterization of the radioactive waste drums' radionuclides content, for final disposal. In order to study the accuracy of the method, a similar concrete matrix with Portland cement in a 200 l drum was used. PMID:24331854

  12. Measurement of {sup 25}Mg(p, {gamma}){sup 26}Al{sup g} resonance strengths via accelerator mass spectrometry

    SciTech Connect

    Arazi, A.; Niello, J. O. Fernandez; Faestermann, T.; Knie, K.; Korschinek, G.; Poutivtsev, M.; Rugel, G.; Richter, E.; Wallner, A.

    2006-08-15

    The strengths of resonances located at center-of-mass energies of E{sub c.m.}=189, 304, 374, and 418 keV for the {sup 25}Mg(p,{gamma}) reaction have been measured for the first time with an off-line method: Mg targets were firstly activated with protons at the resonance energies and the produced {sup 26}Al{sup g} nuclei were counted by means of highly sensitive accelerator mass spectrometry (AMS). Thus, the production of {sup 26}Al in its ground state is determined independently from the {gamma}-decay branching ratio. While the 304, 374, and 418 keV resonances show fair agreement with previous measurements, the 189 keV resonance yield a significantly less strength. In addition, an experimental upper limit for the E{sub c.m.}=92 keV resonance was determined.

  13. In situ determination of salinity by PGNAA.

    PubMed

    Borsaru, M; Smith, C; Merritt, J; Aizawa, T; Rojc, A

    2006-05-01

    Salinity is a very important environmental issue all around the world. In many cases salinity was produced from human activities like farming and mining. Different soluble salts contribute to salinity, however, NaCl is the most common salt producing salinity. This work deals with the application of the prompt gamma neutron activation analysis (PGNAA) technique for in situ determination of salinity. The technique is based on the measurement of chlorine, a component of the common salt, by PGNAA. PMID:16448819

  14. In situ groundwater bioremediation

    SciTech Connect

    Hazen, Terry C.

    2009-02-01

    In situ groundwater bioremediation of hydrocarbons has been used for more than 40 years. Most strategies involve biostimulation; however, recently bioaugmentation have been used for dehalorespiration. Aquifer and contaminant profiles are critical to determining the feasibility and strategy for in situ groundwater bioremediation. Hydraulic conductivity and redox conditions, including concentrations of terminal electron acceptors are critical to determine the feasibility and strategy for potential bioremediation applications. Conceptual models followed by characterization and subsequent numerical models are critical for efficient and cost effective bioremediation. Critical research needs in this area include better modeling and integration of remediation strategies with natural attenuation.

  15. On background radiation gradients--the use of airborne surveys when searching for orphan sources using mobile gamma-ray spectrometry.

    PubMed

    Kock, Peder; Rääf, Christopher; Samuelsson, Christer

    2014-02-01

    Systematic background radiation variations can lead to both false positives and failures to detect an orphan source when searching using car-borne mobile gamma-ray spectrometry. The stochastic variation at each point is well described by Poisson statistics, but when moving in a background radiation gradient the mean count rate will continually change, leading to inaccurate background estimations. Airborne gamma spectrometry (AGS) surveys conducted on the national level, usually in connection to mineral exploration, exist in many countries. These data hold information about the background radiation gradients which could be used at the ground level. This article describes a method that aims to incorporate the systematic as well as stochastic variations of the background radiation. We introduce a weighted moving average where the weights are calculated from existing AGS data, supplied by the Geological Survey of Sweden. To test the method we chose an area with strong background gradients, especially in the thorium component. Within the area we identified two roads which pass through the high-variability locations. The proposed method is compared with an unweighted moving average. The results show that the weighting reduces the excess false positives in the positive background gradients without introducing an excess of failures to detect a source during passage in negative gradients. PMID:24321866

  16. Spiked environmental matrix for use as a reference material for gamma-ray spectrometry: Production and homogeneity test.

    PubMed

    Sobiech-Matura, K; Máté, B; Altzitzoglou, T

    2016-03-01

    The application of a spiking method for reference material production and its utilisation for a food matrix is presented. The raw rice powder was tested by means of γ-ray spectrometry and spiked with a (137)Cs solution. The spiked material was mixed and tested for homogeneity. The future use of the rice powder reference material after the entire characterisation cycle will be for γ-ray spectrometry method validation. PMID:26610369

  17. In Situ Processing.

    ERIC Educational Resources Information Center

    Edgar, T. F.; Schechter, R. S.

    1980-01-01

    Describes research on in situ processing to develop necessary theory and understanding of the underground process to facilitate commercialization of a wide range of mineral deposits. Goal is to produce laboratory and computer-based tools to allow site evaluation based on field and laboratory measurements of mineral and associated overburdens.…

  18. In Situ Cometary Cosmochemistry

    NASA Astrophysics Data System (ADS)

    Wright, I. P.; Andrews, D. J.; Barber, S. J.; Sheridan, S.; Morgan, G. H.; Morse, A. D.

    2013-09-01

    In 2014 the Rosetta space mission arrives at comet 67P. Herein we describe the ambitions of one of the instruments, Ptolemy, included on the lander. Our aim is to make in situ measurements of isotopic compositions of elements such as H, C, N and O.

  19. In situ reactor

    DOEpatents

    Radtke, Corey William; Blackwelder, David Bradley

    2004-01-27

    An in situ reactor for use in a geological strata, is described and which includes a liner defining a centrally disposed passageway and which is placed in a borehole formed in the geological strata; and a sampling conduit is received within the passageway defined by the liner and which receives a geological specimen which is derived from the geological strata, and wherein the sampling conduit is in fluid communication with the passageway defined by the liner.

  20. Chromogenic in Situ Hybridization

    PubMed Central

    Tanner, Minna; Gancberg, David; Di Leo, Angelo; Larsimont, Denis; Rouas, Ghizlane; Piccart, Martine J.; Isola, Jorma

    2000-01-01

    Determination of HER-2/neu oncogene amplification has become necessary for selection of breast cancer patients for trastuzumab (Herceptin) therapy. Fluorescence in situ hybridization (FISH) is currently regarded as a gold standard method for detecting HER-2/neu amplification, but it is not very practical for routine histopathological laboratories. We evaluated a new modification of in situ hybridization, the chromogenic in situ hybridization (CISH), which enables detection of HER-2/neu gene copies with conventional peroxidase reaction. Archival formalin-fixed paraffin-embedded tumor tissue sections were pretreated (by heating in a microwave oven and using enzyme digestion) and hybridized with a digoxigenin-labeled DNA probe. The probe was detected with anti-digoxigenin fluorescein, anti-fluorescein peroxidase, and diaminobenzidine. Gene copies visualized by CISH could be easily distinguished with a 40 objective in hematoxylin-stained tissue sections. HER-2/neu amplification typically appeared as large peroxidase-positive intranuclear gene copy clusters. CISH and FISH (according to Vysis, made from frozen pulverized tumor samples) correlated well in a series of 157 breast cancers (kappa coefficient, 0.81). The few different classifications were mostly because of low-level amplifications by FISH that were negative by CISH and immunohistochemistry with monoclonal antibody CB-11. We conclude that CISH, using conventional bright-field microscopy in evaluation, is a useful alternative for determination of HER-2/neu amplification in paraffin-embedded tumor samples, especially for confirming the immunohistochemical staining results. PMID:11073807

  1. Determining in situ biodegradation

    SciTech Connect

    Madsen, E.L. )

    1991-10-01

    The evolutionary role of microorganisms as effective agents causing the destruction and recycling of organic materials in the biosphere is well established. Nonetheless, in situ biodegradation of organic contaminant compounds is very difficult to prove because the uncontrollability of field sites may prevent the assembly of mass balances and the identification of microbiological contributions to contaminant loss. Several convergent lines of independent evidence from a field site are necessary including laboratory assays for site-containing metabolically adapted organisms, concentration profiles at the site of contaminant losses which indicate microbial metabolism and unequivocal distinctions between biotic and abiotic attenuating processes. Quantitative evidence of in situ biodegradation, lacking in the past, is necessary to prove the efficacy of the biotic process. Three long term challenges for biodegradation scientists that need to be addressed in the future are quantitative determination of in situ biodegradation rates, extension of this determination to complex mixtures of organic compounds, and achievement of a level of contaminant attenuation that complies with health standards set by regulatory agencies. The importance of these challenges cannot be overemphasized.

  2. Evaluation of comparison and proficiency test results of gamma ray spectrometry at Jožef Stefan Institute from 1986 to 2014.

    PubMed

    Glavič-Cindro, Denis; Korun, Matjaž; Nečemer, Marijan; Vodenik, Branko; Zorko, Benjamin

    2016-03-01

    One of the best ways to demonstrate the performance and capabilities of testing laboratories is to participate successfully in different international comparison schemes and proficiency tests. The overview of all results of such schemes in the field of high resolution gamma-ray spectrometry where the Laboratory for Radioactivity Measurements (LMR) of the Jožef Stefan Institute (JSI), Slovenia, participated in years 1986-2014 is presented. Different schemes are compared, strong points and drawbacks of different providers and schemes regarding evaluation procedures, determination of reference values, reporting time, sets of radionuclides included in the samples and range of activities of different radionuclides are discussed. One of the main conclusions is that the comparison and proficiency test samples normally contain substantially larger activities than are usually detected in environmental samples. Therefore the capability of determination of activities close to detection limits is usually covered only by few schemes. PMID:26706285

  3. A Multi-detector NaI(Tl) Gamma-ray Spectrometry System for Investigation of Neutron Induced Capture and Fission Reactions

    NASA Astrophysics Data System (ADS)

    Ruskov, I.; Kopach, Yu. N.; Skoy, V.; Hambsch, F.-J.; Oberstedt, S.

    At the Joint Institute for Nuclear Research (JINR) Frank Laboratory of Neutron Physics (FLNP), a new multi-detector gamma-ray spectrometry system (MDGRSS) was constructed. It consists of 24 hexagonal NaI(Tl) detectors, arranged in two cylindrical arrays of variable diameter and distance between them. Test measurements with the MDGRSS are going on at one of the neutron beam-lines of the pulsed white-spectrum neutron source IREN. Some preliminary results from a measurement of the resonance-neutron flux density at IREN 60m flight-path station, using 181Ta(n,?) reaction, are reported. In combination with a multi-section parallel-plate gas-ionization chamber as a fission fragment detector, positioned in the centre of the system, it is possible to investigate the neutron-induced capture and fission reactions on a number of heavy isotopes, important for fundamental and applied neutron and nuclear physics.

  4. Determination of thorium-232 in Canadian soils by gamma-ray spectrometry via lead-212 and actinium-228, interference from uranium

    SciTech Connect

    Zikovsky, L.; Blagoeva, R.

    1994-12-31

    Thorium-232 background levels in non-cultivated Canadian soils (southern and northern Quebec and the Northwest Territories) are presented. Gamma-ray spectrometry was used to determine the activity of {sup 232}Th by measuring the activities of {sup 228}Ac and {sup 212}Pb at 37 sites. The specific activity levels ranged from 2.7 to 95.5 Bq/kg with an overall mean of 24.0 {+-} 15.4 Bq/kg. This activity generated an annual absorbed dose equivalent in air of 0.1 mSv. The activities of {sup 228}Ac and {sup 212}Pb in the soil increased with increasing depth. IT was found that uranium, via its decay product radium, can interfere with the determination of thorium in the soil.

  5. Intercomparison of inductively coupled plasma mass spectrometry, quantitative neutron capture radiography, and prompt gamma activation analysis for the determination of boron in biological samples.

    PubMed

    Schtz, C L; Brochhausen, C; Hampel, G; Iffland, D; Kuczewski, B; Otto, G; Schmitz, T; Stieghorst, C; Kratz, J V

    2012-10-01

    Boron determination in blood and tissue samples is a crucial task especially for treatment planning, preclinical research, and clinical application of boron neutron capture therapy (BNCT). Comparison of clinical findings remains difficult due to a variety of analytical methods, protocols, and standard reference materials in use. This paper addresses the comparability of inductively coupled plasma mass spectrometry, quantitative neutron capture radiography, and prompt gamma activation analysis for the determination of boron in biological samples. It was possible to demonstrate that three different methods relying on three different principles of sample preparation and boron detection can be validated against each other and yield consistent results for both blood and tissue samples. The samples were obtained during a clinical study for the application of BNCT for liver malignancies and therefore represent a realistic situation for boron analysis. PMID:22918535

  6. Ductal carcinoma in situ.

    PubMed

    Bleicher, Richard J

    2013-04-01

    Management of ductal carcinoma in situ (DCIS) has evolved from radical surgery to the option of a more minimally invasive approach. Data show that breast conservation surgery performed with administration of radiotherapy, like mastectomy, is feasible and safe. Because efforts to find a safe group for elimination of radiotherapy have resulted in data that conflict, radiotherapy still remains standard of care as a part of breast conservation for DCIS. Tamoxifen has also shown a significant recurrence benefit and has become standard in the treatment of receptor-positive disease. Investigation of other agents, such as anastrazole and trastuzumab, are ongoing. PMID:23464692

  7. In Situ Fabrication Technologies

    NASA Technical Reports Server (NTRS)

    Rolin, Terry D.; Hammond, Monica

    2005-01-01

    A manufacturing system is described that is internal to controlled cabin environments which will produce functional parts to net shape with sufficient tolerance, strength and integrity to meet application specific needs such as CEV ECLS components, robotic arm or rover components, EVA suit items, unforeseen tools, conformal repair patches, and habitat fittings among others. Except for start-up and shut-down, fabrication will be automatic without crew intervention under nominal scenarios. Off-nominal scenarios may require crew and/or Earth control intervention. System will have the ability to fabricate using both provisioned feedstock materials and feedstock refined from in situ regolith.

  8. Nondestructive and quantitative characterization of TRU and LLW mixed-waste using active and passive gamma-ray spectrometry and computed tomography

    SciTech Connect

    Camp, D.C.; Martz, H.E.

    1991-11-12

    The technology being proposed by LLNL is an Active and Passive Computed Tomography (A P CT) Drum Scanner for contact-handled (CH) wastes. It combines the advantages offered by two well-developed nondestructive assay technologies: gamma-ray spectrometry and computed tomography (CT). Coupled together, these two technologies offer to nondestructively and quantitatively characterize mixed- wastes forms. Gamma-ray spectroscopy uses one or more external radiation detectors to passively and nondestructively measure the energy spectrum emitted from a closed container. From the resulting spectrum one can identify most radioactivities detected, be they transuranic isotopes, mixed-fission products, activation products or environmental radioactivities. Spectral libraries exist at LLNL for all four. Active (A) or transmission CT is a well-developed, nondestructive medical and industrial technique that uses an external-radiation beam to map regions of varying attenuation within a container. Passive (P) or emission CT is a technique mainly developed for medical application, e.g., single-photon emission CT. Nondestructive industrial uses of PCT are under development and just coming into use. This report discuses work on the A P CT Drum Scanner at LLNL.

  9. Determination of (241)Pu by the method of disturbed radioactive equilibrium using 2πα-counting and precision gamma-spectrometry.

    PubMed

    Alekseev, I; Kuzmina, T

    2016-04-01

    A simple technique is proposed for the determination of the content of (241)Pu, which is based on disturbance of radioactive equilibrium in the genetically related (237)U←(241)Pu→(241)Am decay chain of radionuclides, with the subsequent use of 2πα-counting and precision gamma-spectroscopy for monitoring the process of restoration of that equilibrium. It has been shown that the data on dynamics of accumulation of the daughter (241)Am, which were obtained from the results of measurements of α- and γ-spectra of the samples, correspond to the estimates calculated for the chain of two genetically related radionuclides, the differences in the estimates of (241)Pu radioactivity not exceeding 2%. Combining the different methods of registration (2πα-counting, semiconductor alpha- and gamma-spectrometry) enables the proposed method to be efficiently applied both for calibration of (241)Pu-sources (from several hundreds of kBq and higher) and for radioisotopic analysis of plutonium mixtures. In doing so, there is a deep purification of (241)Pu from its daughter decay products required due to unavailability of commercial detectors that could make it possible, based only on analysis of alpha-spectra, to conduct quantitative analysis of the content of (238)Pu and (241)Am. PMID:26868275

  10. Performance of cerium-doped Gd3Al2Ga3O12 (GAGG:Ce) scintillator in gamma-ray spectrometry

    NASA Astrophysics Data System (ADS)

    Iwanowska, Joanna; Swiderski, Lukasz; Szczesniak, Tomasz; Sibczynski, Pawel; Moszynski, Marek; Grodzicka, Martyna; Kamada, Kei; Tsutsumi, Kousuke; Usuki, Yoshiyuki; Yanagida, Takayuki; Yoshikawa, Akira

    2013-06-01

    Performance of cerium-doped Gd3Al2Ga3O12 (GAGG:Ce) scintillator in gamma-ray spectrometry has been investigated. The measurements of two samples of GAGG:Ce cover the tests of emission spectra (maximum of emission at about 530 nm), light output, non-proportionality, energy resolution, time resolution and decay time of light pulses. We compare the results with commonly known scintillators, such as NaI(Tl), LSO, LuAG etc. The results show that GAGG:Ce has a high light yield of about 33000 ph/MeV as measured with Hamamatsu S3590-18 Si PiN photodiode [1]. The total energy resolution for 662 keV gamma-rays from 137Cs source is equal to about 6%, whereas intrinsic resolution is equal to 5.2%. Additionally, we made basic measurements of photoelectron yield, non-proportionality and total energy resolution of small sample (555 mm3) of GAGG:Ce crystal coupled to Hamamatsu MPPC array (66 mm2). The results show that the performance of GAGG:Ce measured with the MPPC array are similar to those measured with the PMT.

  11. Mass spectrometry in ionospheric research.

    PubMed

    Ferguson, Eldon E

    2007-01-01

    Mass spectrometry played a key role in the development of the understanding of the earth's ionosphere. Of primary importance was its use for in situ atmospheric measurements of the ion and neutral composition of the atmosphere. Mass spectrometry has also played an essential role in the laboratory measurement of critical ionospheric molecular processes. Examples of both are given. PMID:17099890

  12. Mapping the spatial distribution and activity of (226)Ra at legacy sites through Machine Learning interpretation of gamma-ray spectrometry data.

    PubMed

    Varley, Adam; Tyler, Andrew; Smith, Leslie; Dale, Paul; Davies, Mike

    2016-03-01

    Radium ((226)Ra) contamination derived from military, industrial, and pharmaceutical products can be found at a number of historical sites across the world posing a risk to human health. The analysis of spectral data derived using gamma-ray spectrometry can offer a powerful tool to rapidly estimate and map the activity, depth, and lateral distribution of (226)Ra contamination covering an extensive area. Subsequently, reliable risk assessments can be developed for individual sites in a fraction of the timeframe compared to traditional labour-intensive sampling techniques: for example soil coring. However, local heterogeneity of the natural background, statistical counting uncertainty, and non-linear source response are confounding problems associated with gamma-ray spectral analysis. This is particularly challenging, when attempting to deal with enhanced concentrations of a naturally occurring radionuclide such as (226)Ra. As a result, conventional surveys tend to attribute the highest activities to the largest total signal received by a detector (Gross counts): an assumption that tends to neglect higher activities at depth. To overcome these limitations, a methodology was developed making use of Monte Carlo simulations, Principal Component Analysis and Machine Learning based algorithms to derive depth and activity estimates for (226)Ra contamination. The approach was applied on spectra taken using two gamma-ray detectors (Lanthanum Bromide and Sodium Iodide), with the aim of identifying an optimised combination of detector and spectral processing routine. It was confirmed that, through a combination of Neural Networks and Lanthanum Bromide, the most accurate depth and activity estimates could be found. The advantage of the method was demonstrated by mapping depth and activity estimates at a case study site in Scotland. There the method identified significantly higher activity (<3Bqg(-1)) occurring at depth (>0.4m), that conventional gross counting algorithms failed to identify. It was concluded that the method could easily be employed to identify areas of high activity potentially occurring at depth, prior to intrusive investigation using conventional sampling techniques. PMID:26795756

  13. In Situ Surface Characterization

    NASA Technical Reports Server (NTRS)

    Deen, Robert G.; Leger, Patrick C.; Yanovsky, Igor

    2011-01-01

    Operation of in situ space assets, such as rovers and landers, requires operators to acquire a thorough understanding of the environment surrounding the spacecraft. The following programs help with that understanding by providing higher-level information characterizing the surface, which is not immediately obvious by just looking at the XYZ terrain data. This software suite covers three primary programs: marsuvw, marsrough, and marsslope, and two secondary programs, which together use XYZ data derived from in situ stereo imagery to characterize the surface by determining surface normal, surface roughness, and various aspects of local slope, respectively. These programs all use the Planetary Image Geometry (PIG) library to read mission-specific data files. The programs themselves are completely multimission; all mission dependencies are handled by PIG. The input data consists of images containing XYZ locations as derived by, e.g., marsxyz. The marsuvw program determines surface normals from XYZ data by gathering XYZ points from an area around each pixel and fitting a plane to those points. Outliers are rejected, and various consistency checks are applied. The result shows the orientation of the local surface at each point as a unit vector. The program can be run in two modes: standard, which is typically used for in situ arm work, and slope, which is typically used for rover mobility. The difference is primarily due to optimizations necessary for the larger patch sizes in the slope case. The marsrough program determines surface roughness in a small area around each pixel, which is defined as the maximum peak-to-peak deviation from the plane perpendicular to the surface normal at that pixel. The marsslope program takes a surface normal file as input and derives one of several slope-like outputs from it. The outputs include slope, slope rover direction (a measure of slope radially away from the rover), slope heading, slope magnitude, northerly tilt, and solar energy (compares the slope with the Sun s location at local noon). The marsuvwproj program projects a surface normal onto an arbitrary plane in space, resulting in a normalized 3D vector, which is constrained to lie in the plane. The marsuvwrot program rotates the vectors in a surface normal file, generating a new surface normal file. It also can change coordinate systems for an existing surface normal file. While the algorithms behind this suite are not particularly unique, what makes the programs useful is their integration into the larger in situ image processing system via the PIG library. They work directly with space in situ data, understanding the appropriate image metadata fields and updating them properly. The secondary programs (marsuvwproj, marsuvwrot) were originally developed to deal with anomalous situations on Opportunity and Spirit, respectively, but may have more general applicability.

  14. Use of airborne gamma-ray spectrometry for environmental assessment of the rehabilitated nabarlek uranium mine, Australia.

    PubMed

    Martin, Paul; Tims, Stephen; McGill, Anthony; Ryan, Bruce; Pfitzner, Kirrilly

    2006-04-01

    This article describes an airborne gamma survey of a 7 x 5 km region around the rehabilitated Nabarlek uranium mine in northern Australia. An unusually tight line spacing (100 m) and low aircraft height (50 m) were used, enabling the survey to distinguish man-made structures such as ponds and accommodation areas, as well as creek lines. Positive correlations between airborne data and ground-based readings enabled an estimation of the average absorbed dose rate arising from terrestrial gamma radiation over large areas of the site to be derived. For the fenced minesite area this estimate was 0.31 micro Gy hr(- 1). The airborne survey data were found to be invaluable in helping to plan further ground-level investigations and showed promise as an assessment tool for rehabilitated minesites. PMID:16649135

  15. In situ measurement system

    DOEpatents

    Lord, D.E.

    1980-11-24

    A multipurpose in situ underground measurement system comprising a plurality of long electrical resistance elements in the form of rigid reinforcing bars, each having an open loop hairpin configuration of shorter length than the other resistance elements. The resistance elements are arranged in pairs in a unitized structure, and grouted in place in the underground volume. Measurement means are provided for obtaining for each pair the electrical resistance of each element and the difference in electrical resistance of the paired elements, which difference values may be used in analytical methods involving resistance as a function of temperature. A scanner means sequentially connects the resistance-measuring apparatus to each individual pair of elements. A source of heating current is also selectively connectable for heating the elements to an initial predetermined temperature prior to electrical resistance measurements when used as an anemometer.

  16. Assessing sample attenuation parameters for use in low-energy efficiency transfer in gamma-ray spectrometry.

    PubMed

    Bruggeman, M; Verheyen, L; Vidmar, T; Liu, B

    2016-03-01

    We present a numerical fitting method for transmission data that outputs an equivalent sample composition. This output is used as input to a generalised efficiency transfer model based on the EFFTRAN software integrated in a LIMS. The procedural concept allows choosing between efficiency transfer with a predefined sample composition or with an experimentally determined composition based on a transmission measurement. The method can be used for simultaneous quantification of low-energy gamma emitters like (210)Pb, (241)Am, (234)Th in typical environmental samples. PMID:26688363

  17. The natural radioactivity measurements in coastal sediment samples along the East Coast of Tamilnadu using gamma spectrometry technique

    NASA Astrophysics Data System (ADS)

    Chandramohan, J.; Tholkappian, M.; Harikrishnan, N.; Ravisankar, R.

    2015-08-01

    The natural radioactivity concentration in beach sediment samples collected from Pattipulam to Devanampattinam of East Coast of Tamilnadu have been determined by NaI (TI) gamma ray spectrometer. The specific activity concentrations range from ≤ 2.21 (BDL) to 37.02 Bq kg-1 with a mean of 3.79 Bqkg-1 for 238U, ≤ 2.11 (BDL) to 643.77 Bqkg-1 with a mean of 49.60 Bqkg-1 for 232Th and 300.34 Bqkg-1 to 449.08 Bqkg-1 with a mean of 360.23 Bqkg-1 for 40K. The potential radiological hazards due to natural radionuclides content such as Radium Equivalent activity (Raeq), Representative level index (RLI), External hazard index (Hex), absorbed gamma does rate (DR), and Annual effective dose rate (AEDR) are estimated to assess the radiation hazard associated with the sediments. The obtained data are compared with the recommended safety limits and international approved values. All the values are well below the recommended safety limits indicating that radiation levels do not poses any significant health hazard to the public in the area as a result of the natural radioactivity of beach sediments. This study may help the baseline data for more extensive works in the same subjects of future studies.

  18. Savannah River Site Experiences in In Situ Field Measurements of Radioactive Materials

    SciTech Connect

    Moore, F.S.

    1999-10-07

    This paper discusses some of the field gamma-ray measurements made at the Savannah River Site, the equipment used for the measurements, and lessons learned during in situ identification and characterization of radioactive materials.

  19. Investigation of the environmental impacts of naturally occurring radionuclides in the processing of sulfide ores for gold using gamma spectrometry.

    PubMed

    Gbadago, J K; Faanhof, A; Darko, E O; Schandorf, C

    2011-09-01

    The possible environmental impacts of naturally occurring radionuclides on workers and a critical community, as a result of milling and processing sulfide ores for gold by a mining company at Bogoso in the western region of Ghana, have been investigated using gamma spectroscopy. Indicative doses for the workers during sulfide ore processing were calculated from the activity concentrations measured at both physical and chemical processing stages. The dose rate, annual effective dose equivalent, radium equivalent activity, external and internal hazard indices, and radioactivity level index for tailings, for the de-silted sediments of run-off from the vicinity of the tailings dam through the critical community, and for the soils of the critical community's basic schools were calculated and found to be lower than their respective permissible limits. The environmental impact of the radionuclides is therefore expected to be low in this mining environment. PMID:21865616

  20. Iron and titanium distribution on the moon from orbital gamma ray spectrometry with implications for crustal evolutionary models

    NASA Technical Reports Server (NTRS)

    Davis, P. A., Jr.

    1980-01-01

    A set of Fe and Ti maps and regional values are obtained from the Apollo 15 and 16 orbital gamma ray data by energy band analysis. High-Ti basalts predominate the early and late stages of mare volcanism with high-Fe basaltic volcanism in the interim. The first evidence of a high-Ti-KREEP basalt association is found in the Aristarchus region. A N-S asymmetry for Fe and Ti in the east limb and farside highlands complicates the E-W asymmetry for Th but substantiates crustal inhomogeneity. The observed crustal inhomogeneity adds an additional objection to the primitive source model for crustal evolution. The high-Ti-KREEP basalt association and the general trend of decreasing mare basalt Ti with time lend support to the cumulate source model; however, this model cannot account for young, high-Ti maria. The dynamic assimilation model better accounts for chemical variations observed on the moon.

  1. Modeling in situ vitrification

    SciTech Connect

    Mecham, D.C.; MacKinnon, R.J.; Murray, P.E.; Johnson, R.W.

    1990-01-01

    In Situ Vitrification (ISV) process is being assessed by the Idaho National Engineering Laboratory (INEL) to determine its applicability to transuranic and mixed wastes buried at INEL'S Subsurface Disposal Area (SDA). This process uses electrical resistance heating to melt waste and contaminated soil in place to produce a durable glasslike material that encapsulates and immobilizes buried wastes. This paper outlines the requirements for the model being developed at the INEL which will provide analytical support for the ISV technology assessment program. The model includes representations of the electric potential field, thermal transport with melting, gas and particulate release, vapor migration, off-gas combustion and process chemistry. The modeling objectives are to help determine the safety of the process by assessing the air and surrounding soil radionuclides and chemical pollution hazards, the nuclear criticality hazard, and the explosion and fire hazards, help determine the suitability of the ISV process for stabilizing the buried wastes involved, and help design laboratory and field tests and interpret results. 3 refs., 2 figs., 1 tab.

  2. IN SITU STEAM EXTRACTION TREATMENT

    EPA Science Inventory

    In situ steam extraction removes volatile and semivolatile hazardous contaminants from soil and groundwater without excavation of the hazardous waste. aste constituents are removed in situ by the technology and are not actually treated. he use of steam enhances the stripping of v...

  3. In Situ Nuclear Characterization Infrastructure

    SciTech Connect

    James A. Smith; J. Rory Kennedy

    2011-11-01

    To be able to evolve microstructure with a prescribed in situ process, an effective measurement infrastructure must exist. This interdisciplinary infrastructure needs to be developed in parallel with in situ sensor technology. This paper discusses the essential elements in an effective infrastructure.

  4. Real-time monitoring of in situ gas-phase H/D exchange reactions of cations by atmospheric pressure helium plasma ionization mass spectrometry (HePI-MS).

    PubMed

    Attygalle, Athula B; Gangam, Rekha; Pavlov, Julius

    2014-01-01

    An enclosed atmospheric-pressure helium-plasma ionization (HePI-MS) source avoids, or minimizes, undesired back-exchange reactions usually encountered during deuterium incorporation experiments under ambient-pressure open-source conditions. A simple adaptation of an ESI source provides an economical way of conducting gas phase hydrogen/deuterium (H/D) exchange reactions (HDX) in real time without the need for complicated hardware modifications. For example, the spectrum of [(2)H8]toluene recorded under exposed ambient conditions showed the base peak at m/z 96 due to fast leaching of ring hydrogens because of interactions with H2O vapor present in the open source. Such D/H exchanges are rapidly reversed if the deuterium-depleted [(2)H8]toluene is exposed to D2O vapor. In addition to the enumeration of labile protons, our procedure enables the identification of protonation sites in molecules unambiguously, by the number of H/D exchanges observed in real time. For example, molecules such as tetrahydrofuran and pyridine protonate at the heteroatom and consequently undergo only one H/D exchange, whereas ethylbenzene, which protonates at a ring position of the aromatic ring, undergoes six H/D exchanges. In addition, carbocations generated in situ by in-source fragmentation of precursor protonated species, such as benzyl alcohol, do not undergo any rapid H/D exchanges. Because radical cations, second-generation cations (ions formed by losing a small molecule from a precursor ion), or those formed by hydride abstraction do not undergo rapid H/D exchanges, our technique provides a way to distinguish these ions from protonated molecules. PMID:24325360

  5. Continued Development of in Situ Geochronology for Planetary Missions

    NASA Technical Reports Server (NTRS)

    Devismes, D.; Cohen, B. A.

    2015-01-01

    The instrument 'Potassium (K) Argon Laser Experiment' (KArLE) is developed and designed for in situ absolute dating of rocks on planetary surfaces. It is based on the K-Ar dating method and uses the Laser Induced Breakdown Spectroscopy - Laser Ablation - Quadrupole Mass Spectrometry (LIBSLA- QMS) technique. We use a dedicated interface to combine two instruments similar to SAM of Mars Science Laboratory (for the QMS) and ChemCam (for the LA and LIBS). The prototype has demonstrated that KArLE is a suitable and promising instrument for in situ absolute dating.

  6. Technical review: In situ hybridization.

    PubMed

    Jensen, Ellen

    2014-08-01

    In situ hybridization is a technique that is used to detect nucleotide sequences in cells, tissue sections, and even whole tissue. This method is based on the complementary binding of a nucleotide probe to a specific target sequence of DNA or RNA. These probes can be labeled with either radio-, fluorescent-, or antigen-labeled bases. Depending on the probe used, autoradiography, fluorescence microscopy, or immunohistochemistry, respectively, are used for visualization. In situ hybridization is extensively used in research, as well as clinical applications, especially for diagnostic purposes. This review discusses the basic technique of in situ hybridization. The standard in situ hybridization process is reviewed, and different types of in situ hybridization, their applications, and advantages and disadvantages are discussed. PMID:24810158

  7. LAFARA: a new underground laboratory in the French Pyrénées for ultra low-level gamma-ray spectrometry.

    TOXLINE Toxicology Bibliographic Information

    van Beek P; Souhaut M; Lansard B; Bourquin M; Reyss JL; von Ballmoos P; Jean P

    2013-02-01

    We describe a new underground laboratory, namely LAFARA (for "LAboratoire de mesure des FAibles RAdioactivités"), that was recently created in the French Pyrénées. This laboratory is primarily designed to analyze environmental samples that display low radioactivity levels using gamma-ray spectrometry. Two high-purity germanium detectors were placed under 85 m of rock (ca. 215 m water equivalent) in the tunnel of Ferrières (Ariège, France). The background is thus reduced by a factor of ∼20 in comparison to above-ground laboratories. Both detectors are fully equipped so that the samples can be analyzed in an automatic mode without requiring permanent presence of a technician in the laboratory. Auto-samplers (twenty positions) and systems to fill liquid nitrogen automatically provide one month of autonomy to the spectrometers. The LAFARA facility allows us to develop new applications in the field of environmental sciences based on the use of natural radionuclides present at low levels in the environment. As an illustration, we present two of these applications: i) dating of marine sediments using the decay of (226)Ra in sedimentary barite (BaSO(4)), ii) determination of (227)Ac ((231)Pa) activities in marine sediment cores.

  8. LAFARA: a new underground laboratory in the French Pyrénées for ultra low-level gamma-ray spectrometry.

    PubMed

    van Beek, P; Souhaut, M; Lansard, B; Bourquin, M; Reyss, J-L; von Ballmoos, P; Jean, P

    2013-02-01

    We describe a new underground laboratory, namely LAFARA (for "LAboratoire de mesure des FAibles RAdioactivités"), that was recently created in the French Pyrénées. This laboratory is primarily designed to analyze environmental samples that display low radioactivity levels using gamma-ray spectrometry. Two high-purity germanium detectors were placed under 85 m of rock (ca. 215 m water equivalent) in the tunnel of Ferrières (Ariège, France). The background is thus reduced by a factor of ∼20 in comparison to above-ground laboratories. Both detectors are fully equipped so that the samples can be analyzed in an automatic mode without requiring permanent presence of a technician in the laboratory. Auto-samplers (twenty positions) and systems to fill liquid nitrogen automatically provide one month of autonomy to the spectrometers. The LAFARA facility allows us to develop new applications in the field of environmental sciences based on the use of natural radionuclides present at low levels in the environment. As an illustration, we present two of these applications: i) dating of marine sediments using the decay of (226)Ra in sedimentary barite (BaSO(4)), ii) determination of (227)Ac ((231)Pa) activities in marine sediment cores. PMID:23164692

  9. Evaluation of natural radioactivity content in high-volume surface water samples along the northern coast of Oman Sea using portable high-resolution gamma-ray spectrometry.

    PubMed

    Zare, Mohammad Reza; Kamali, Mahdi; Omidi, Zohre; Khorambagheri, Mahdi; Mortazavi, Mohammad Seddigh; Ebrahimi, Mahmood; Akbarzadeh, Gholamali

    2015-06-01

    Portable high-resolution gamma-ray spectrometry was carried out to determine the natural radioactivity levels in high volume surface water samples of the northern coast of Oman Sea, covering the coastal strip from Hormoz strait to Goatr seaport, for the first time. The water samples from 36 coastal and near shore locations were collected for analysis. Analyses on the samples collected were carried out to determine (226)Ra, (232)Th and (40)K contents. The concentration of (226)Ra, (232)Th and (40)K in surface water samples ranged between 2.19 and 2.82 Bq/L, 1.66-2.17 Bq/L and 132.6-148.87 Bq/L, respectively. The activity profile of radionuclides shows low activity across the study area. The study also examined some radiation hazard indices. The external hazard index was found to be less than 1, indicating a low dose. The results of measurements will serve as background reference level for Oman Sea coastlines. PMID:25847859

  10. In situ mercury stabilization

    SciTech Connect

    Fuhrmann, M.; Kalb, P.; Adams, J.

    2004-09-01

    BNL Royalty Project Internal Status Report. The funds from the allotment of royalty income were used to experimentally explore feasibility of related, potential new techniques based on the Environmental Sciences Department successful technology licensed for the ex situ treatment of mercury. Specifically, this work is exploring the concept of using Sulfur Polymer Cement (SPC) in an in situ application to stabilize and/or remove mercury (Hg) from surficial soil. Patent disclosure forms have been filed for this process. Soil was artificially spiked with 500 ppm Hg and a series of experiments were set up in which SPC rods were placed in the center of a mass of this soil. Some experiments were conducted at 20 C and others at 50 C. After times ranging from 11 to 24 days, these experiments were opened, photographed and the soil was sampled from discrete locations in the containers. The soil and SPC samples were analyzed for Fe and Hg by x-ray fluorescence. The Hg profile in the soil was significantly altered, with concentrations along the outer edge of the soil reduced by as much as 80% from the starting concentration. Conversely, closer to the treatment rod containing SPC, concentrations of Hg were significantly increased over the original concentration. Preliminary results for elevated temperature sample are shown graphically in Figure 2. Apparently the Hg had migrated toward the SPC and reacted with sulfur to form Hg S. This appears to be a reaction between gaseous phases of both S and Hg, with Hg having a greater vapor pressure. The concentration of low solubility HgS (i.e., low leaching properties) developed within 11 days at 50 C and 21 days at 20 C, confirming the potential of this concept.

  11. Publication bias in situ

    PubMed Central

    Phillips, Carl V

    2004-01-01

    Background Publication bias, as typically defined, refers to the decreased likelihood of studies' results being published when they are near the null, not statistically significant, or otherwise "less interesting." But choices about how to analyze the data and which results to report create a publication bias within the published results, a bias I label "publication bias in situ" (PBIS). Discussion PBIS may create much greater bias in the literature than traditionally defined publication bias (the failure to publish any result from a study). The causes of PBIS are well known, consisting of various decisions about reporting that are influenced by the data. But its impact is not generally appreciated, and very little attention is devoted to it. What attention there is consists largely of rules for statistical analysis that are impractical and do not actually reduce the bias in reported estimates. PBIS cannot be reduced by statistical tools because it is not fundamentally a problem of statistics, but rather of non-statistical choices and plain language interpretations. PBIS should be recognized as a phenomenon worthy of study it is extremely common and probably has a huge impact on results reported in the literature and there should be greater systematic efforts to identify and reduce it. The paper presents examples, including results of a recent HIV vaccine trial, that show how easily PBIS can have a large impact on reported results, as well as how there can be no simple answer to it. Summary PBIS is a major problem, worthy of substantially more attention than it receives. There are ways to reduce the bias, but they are very seldom employed because they are largely unrecognized. PMID:15296515

  12. Experimental study on neptunium migration under in situ geochemical conditions

    NASA Astrophysics Data System (ADS)

    Kumata, M.; Vandergraaf, T. T.

    1998-12-01

    Results are reported for migration experiments performed with Np under in situ geochemical conditions over a range of groundwater flow rates in columns of crushed rock in a specially designed facility at the 240-level of the Underground Research Laboratory (URL) near Pinawa, Manitoba, Canada. This laboratory is situated in an intrusive granitic rock formation, the Lac du Bonnet batholith. Highly altered granitic rock and groundwater were obtained from a major subhorizontal fracture zone at a depth of 250 m in the URL. The granite was wet-crushed and wet-sieved with groundwater from this fracture zone. The 180-850-?m size fraction was selected and packed in 20-cm long, 2.54-cm in diameter Teflon-lined stainless steel columns. Approximately 30-ml vols of groundwater containing 3HHO and 237Np were injected into the columns at flow rates of 0.3, 1, and 3 ml/h, followed by elution with groundwater, obtained from the subhorizontal fracture, at the same flow rates, for a period of 95 days. Elution profiles for 3HHO were obtained, but no 237Np was detected in the eluted groundwater. After terminating the migration experiments, the columns were frozen, the column material was removed and cut into twenty 1-cm thick sections and each section was analyzed by gamma spectrometry. Profiles of 237Np were obtained for the three columns. A one-dimensional transport model was fitted to the 3HHO breakthrough curves to obtain flow parameters for this experiment. These flow parameters were in turn applied to the 237Np concentration profiles in the columns to produce sorption and dispersion coefficients for Np. The results show a strong dependence of retardation factors ( Rf) on flow rate. The decrease in the retarded velocity of the neptunium ( Vn) varied over one order of magnitude under the geochemical conditions for these experiments.

  13. The use of MCNP and gamma spectrometry in supporting the evaluation of NORM in Libyan oil pipeline scale

    NASA Astrophysics Data System (ADS)

    Habib, Ahmed S.; Bradley, D. A.; Regan, P. H.; Shutt, A. L.

    2010-07-01

    The accumulation of scales in production pipes is a common problem in the oil industry, reducing fluid flow and also leading to costly remedies and disposal issues. Typical materials found in such scale are sulphates and carbonates of calcium and barium, or iron sulphide. Radium arising from the uranium/thorium present in oil-bearing rock formations may replace the barium or calcium in these salts to form radium salts. This creates what is known as technologically enhanced naturally occurring radioactive material (TENORM or simply NORM). NORM is a serious environmental and health and safety issue arising from commercial oil and gas extraction operations. Whilst a good deal has been published on the characterisation and measurement of radioactive scales from offshore oil production, little information has been published regarding NORM associated with land-based facilities such as that of the Libyan oil industry. The ongoing investigation described in this paper concerns an assessment of NORM from a number of land based Libyan oil fields. A total of 27 pipe scale samples were collected from eight oil fields, from different locations in Libya. The dose rates, measured using a handheld survey meter positioned on sample surfaces, ranged from 0.1-27.3 ?Sv h -1. In the initial evaluations of the sample activity, use is being made of a portable HPGe based spectrometry system. To comply with the prevailing safety regulations of the University of Surrey, the samples are being counted in their original form, creating a need for correction of non-homogeneous sample geometries. To derive a detection efficiency based on the actual sample geometries, a technique has been developed using a Monte Carlo particle transport code (MCNPX). A preliminary activity determination has been performed using an HPGe portable detector system.

  14. In-situ measurement of residual carbon content in flyash

    SciTech Connect

    Bonanno, A.S.; Knight, K.S.; Kinsella, K.; Serio, M.A.; Solomon, P.R.

    1995-12-31

    An on-line carbon-in-ash monitor based on in-situ infrared emission spectrometry is described. Laboratory measurements of the infrared spectral emissivity of flyash are presented in order to demonstrate that emissivity can be correlated to the residual carbon content in the range of interest for pulverized coal-fired power plants. Data collected during a field test at a pilot-scale combustor are presented in order to demonstrate that the emissivity measurements could be made in-situ on a realistic facility, and that the spectral emissivity could be correlated to the residual carbon content. Since this measurement can be made in-situ in a few seconds using an FT-IR spectrometer, an infrared emissivity based carbon-in-ash monitoring will be capable of providing data on a time scale appropriate for implementation in combustion control strategies while avoiding the disadvantages associated with extractive ash sampling.

  15. Assessing soil erosion at landscape level: A step forward in the up-scaling of 137Cs measurements through the use of in-situ lanthanum bromide scintillator

    NASA Astrophysics Data System (ADS)

    Gonsalves, Basil C.; Darby, Iain G.; Toloza, Arsenio; Mabit, Lionel; Kaiser, Ralf B.; Dercon, Gerd

    2014-05-01

    Measuring Fallout Radionuclides (FRN), in particular 137Cs, is a well-established method to estimate soil erosion and deposition in agricultural landscapes. While extremely sensitive, laboratory based gamma-ray spectrometry requires careful handling and preparation of measurement samples with a lengthy measuring time (~1 day), In-situ gamma-ray spectrometry can give near instantaneous results, allowing prompt decisions to be made and identification of critical spots of soil erosion, while the equipment is in the field. The aim of this investigation was to compare the precision of the in-situ FRN measurements, made by a cost-effective lanthanum bromide (LaBr3 (Ce)) scintillation detector of 137Cs against those from conventional (high-purity germanium HPGe detector) but laborious laboratory based gamma-ray spectrometry for assessing soil erosion. As preliminary test, five cores of a gleyic Cambisol - per increments of 5 cm until 1 m depth - were collected at the experimental research station of the Austrian Agency for Health and Food Safety located in Grabenegg 130 km west of Vienna. Three soil cores were sampled at the study site and, in the vicinity of this experimental site, two additional cores were collected at two different undisturbed reference sites. Laboratory gamma analyses were carried out during 50 000 seconds using a HPGe coaxial detector. The gamma measurements performed at the laboratory confirmed the undisturbed status of the two selected reference sites (i.e. exponential decrease with depth of the 137Cs content). Using the surface area of the sampling tool, the 137Cs areal activities of the cores sampled in the study site have been established at 2134±465 Bq m-2, 1835±356 Bq m-2 and 2553±340 Bq m-2, and, for the two reference sites at 3221±444 Bq m-2 and 3946±527 Bq m-2. At the same location and prior to collect the five soil cores, in-situ measurements using a lanthanum bromide (LaBr3 (Ce)) scintillator were performed. The detector was placed at 2 cm above ground and each measurement was conducted for 900 seconds. A significant positive correlation (i.e. R2=0.82; p < 0.001) has been established between the 137Cs areal activities obtained with the in-situ and laboratory based measurements. The first results relating to in-situ measurement of 137Cs offer an exciting potential for the application of FRN measurements and their up-scaling in the framework of soil erosion assessments at the landscape level. This includes cost, time, and portability, the potential to work in remote areas, pre-screening to develop more effective sampling strategies and rapid repeat surveys. This work is still in its initial stage and more research is required to validate this innovative in-situ technique.

  16. IN SITU ENHANCED SOURCE REMOVAL

    EPA Science Inventory

    This html report describes and compares the performance of in situ technologies designed to accelerate the removal of organic contaminants from unconsolidated soils and aquifers. The research was conducted through the Enhanced Source Removal (ESR) Program within the Subsurface Pr...

  17. In Situ Activation of Microcapsules

    NASA Technical Reports Server (NTRS)

    Morrison, Dennis R. (Inventor); Mosier, Benjamin (Inventor)

    2000-01-01

    Disclosed are microcapsules comprising a polymer shell enclosing two or more immiscible liquid phases in which a drug, or a prodrug and a drug activator are partitioned into separate phases. or prevented from diffusing out of the microcapsule by a liquid phase in which the drug is poorly soluble. Also disclosed are methods of using the microcapsules for in situ activation of drugs where upon exposure to an appropriate energy source the internal phases mix and the drug is activated in situ.

  18. Evaluating airborne and ground based gamma spectrometry methods for detecting particulate radioactivity in the environment: a case study of Irish Sea beaches.

    PubMed

    Cresswell, A J; Sanderson, D C W

    2012-10-15

    In several places, programmes are in place to locate and recover radioactive particles that have the potential to cause detrimental health effects in any member of the public who may encounter them. A model has been developed to evaluate the use of mobile gamma spectrometry systems within such programmes, with particular emphasis on large volume (16l) NaI(Tl) detectors mounted in low flying helicopters. This model uses a validated Monte Carlo code with assessment of local geochemistry and natural and anthropogenic background radiation concentrations and distributions. The results of the model, applied to the example of particles recovered from beaches in the vicinity of Sellafield, clearly show the ability of rapid airborne surveys conducted at 75 m ground clearance and 120 kph speeds to demonstrate the absence of sources greater than 5 MBq (137)Cs within large areas (10-20 km(2)h(-1)), and identify areas requiring further ground based investigation. Lowering ground clearance for airborne surveys to 15m whilst maintaining speeds covering 1-2 km(2) h(-1) can detect buried (137)Cs sources of 0.5MBq or greater activity. A survey design to detect 100 kBq (137)Cs sources at 10 cm depth has also been defined, requiring surveys at <15m ground clearance and <2 ms(-1) ground speed. The response of airborne systems to the Sellafield particles recovered to date has also been simulated, and the proportion of the existing radiocaesium background in the vicinity of the nuclear site has been established. Finally the rates of area coverage and sensitivities of both airborne and ground based approaches are compared, demonstrating the ability of airborne systems to increase the rate of particle recovery in a cost effective manner. The potential for equipment and methodological developments to improve performance are discussed. PMID:22947616

  19. TRIO-01 experiment: in-situ tritium-recovery results

    SciTech Connect

    Clemmer, R.G.; Finn, P.A.; Billone, M.C.; Misra, B.; Arons, R.M.; Poeppel, R.B.; Dyer, F.F.; Dudley, I.T.; Bate, L.C.; Clemmer, E.D.

    1983-08-01

    The TRIO-01 experiment is a test of in-situ tritium recovery from ..gamma..-LiAlO/sub 2/ with test conditions chosen to simulate those anticipated in fusion power reactors. A status report is presented which describes qualitatively the results observed during the irradiation phase of the experiment. Both the rate of tritium release and the chemical forms of tritium were measured using a helium sweep gas which flowed past the breeder material to a gas analysis system.

  20. TRIO-01 experiment: in-situ tritium recovery results

    SciTech Connect

    Clemmer, R.G.; Finn, P.A.; Billone, M.C.; Misra, B.; Greenwood, L.R.; Dyer, F.F.; Dudley, I.T.; Bate, L.C.; Clemmer, E.D.; Fisher, P.W.

    1983-01-01

    The TRIO-01 experiment was designed to test in-situ tritium recovery and heat transfer performance of a candidate solid breeder, ..gamma..-LiAlO/sub 2/. The results showed that nearly all the tritium generated was recovered. Only < 0.1 wppM tritium remained in the solid after irradiation testing. The heat transfer performance showed that temperature profiles can be effectively controlled.

  1. In situ microbial filter used for bioremediation

    DOEpatents

    Carman, M. Leslie; Taylor, Robert T.

    2000-01-01

    An improved method for in situ microbial filter bioremediation having increasingly operational longevity of an in situ microbial filter emplaced into an aquifer. A method for generating a microbial filter of sufficient catalytic density and thickness, which has increased replenishment interval, improved bacteria attachment and detachment characteristics and the endogenous stability under in situ conditions. A system for in situ field water remediation.

  2. Triplex in-situ hybridization

    DOEpatents

    Fresco, Jacques R. (Princeton, NJ); Johnson, Marion D. (East Windsor, NJ)

    2002-01-01

    Disclosed are methods for detecting in situ the presence of a target sequence in a substantially double-stranded nucleic acid segment, which comprises: a) contacting in situ under conditions suitable for hybridization a substantially double-stranded nucleic acid segment with a detectable third strand, said third strand being capable of hybridizing to at least a portion of the target sequence to form a triple-stranded structure, if said target sequence is present; and b) detecting whether hybridization between the third strand and the target sequence has occured.

  3. Very little in situ produced radiocarbon retained in accumulating Antarctic ice

    NASA Astrophysics Data System (ADS)

    van der Kemp, W. J. M.; Alderliesten, C.; van der Borg, K.; Holmlund, P.; de Jong, A. F. M.; Karlf, L.; Lamers, R. A. N.; Oerlemans, J.; Thomassen, M.; van de Wal, R. S. W.

    2000-10-01

    Ice samples from Dronning Maud Land, Antarctica, were analyzed for 14CO 2 and 14CO by accelerator mass spectrometry. Only a small amount (2%) of in situ produced radiocarbon was detected. The calibrated radiocarbon ages, corrected for in situ produced 14C, are in fair agreement with age estimates obtained from stratigraphical methods added to a gas inclusion model. The ages of the entrapped air range from recent to ca. 1200 AD.

  4. In situ biofilm coupon device

    DOEpatents

    Peyton, Brent M.; Truex, Michael J.

    1997-01-01

    An apparatus for characterization of in-situ microbial biofilm populations in subsurface groundwater. The device permits biofilm-forming microorganisms to adhere to packing material while emplaced in a groundwater strata, so that the packing material can be later analyzed for quantity and type of microorganisms, growth rate, and nutrient requirements.

  5. In situ biofilm coupon device

    DOEpatents

    Peyton, B.M.; Truex, M.J.

    1997-06-24

    An apparatus is disclosed for characterization of in-situ microbial biofilm populations in subsurface groundwater. The device permits biofilm-forming microorganisms to adhere to packing material while emplaced in a groundwater strata, so that the packing material can be later analyzed for quantity and type of microorganisms, growth rate, and nutrient requirements. 3 figs.

  6. Strategies for In situ and Sample Return Analyses

    NASA Astrophysics Data System (ADS)

    Papanastassiou, D. A.

    2006-12-01

    There is general agreement that planetary exploration proceeds from orbital reconnaissance of a planet, to surface and near-surface in situ exploration, to sample return missions, which bring back samples for investigations in terrestrial laboratories, using the panoply of state-of-the-art analytical techniques. The applicable techniques may depend on the nature of the returned material and complementary and multi- disciplinary techniques can be used to best advantage. High precision techniques also serve to provide the "ground truth" and calibrate past and future orbital and in situ measurements on a planet. It is also recognized that returned samples may continue to be analyzed by novel techniques as the techniques become developed, in part to address specific characteristics of returned samples. There are geophysical measurements such as those of the moment of inertia of a planet, seismic activity, and surface morphology that depend on orbital and in-situ science. Other characteristics, such as isotopic ages and isotopic compositions (e.g., initial Sr and Nd) as indicators of planetary mantle or crust evolution and sample provenance require returned samples. In situ analyses may be useful for preliminary characterization and for optimization of sample selection for sample return. In situ analyses by Surveyor on the Moon helped identify the major element chemistry of lunar samples and the need for high precision mass spectrometry (e. g., for Rb-Sr ages, based on extremely low alkali contents). The discussion of in-situ investigations vs. investigations on returned samples must be directly related to available instrumentation and to instrumentation that can be developed in the foreseeable future. The discussion of choices is not a philosophical but instead a very practical issue: what precision is required for key investigations and what is the instrumentation that meets or exceeds the required precision. This must be applied to potential in situ instruments and to laboratory instruments. Age determinations and use of isotopes for deciphering planetary evolution are viewed as off-limits for in-situ determinations, as they require: a) typically high precision mass spectrometry (at 0.01% and below); b) the determination of parent-daughter element ratios at least at the percent level; c) the measurement of coexisting minerals (for internal isochron determinations); d) low contamination (e. g., for U-Pb and Pb-Pb); and e) removal of adhering phases and contaminants, not related to the samples to be analyzed. Total K-Ar age determinations are subject to fewer requirements and may be feasible, in situ, but in the absence of neutron activation, as required for 39Ar-40Ar, the expected precision is at the level of ~20%, with trapped Ar in the samples introducing further uncertainty. Precision of 20% for K-Ar may suffice to address some key cratering rate uncertainties on Mars, especially as applicable to the Middle Amazonian(1). For in situ, the key issues, which must be addressed for all measurements are: what precision is required and are there instruments available, at the required precision levels. These issues must be addressed many years before a mission gets defined. Low precision instruments on several in situ missions that do not address key scientific questions may in fact be more expensive, in their sum, than a sample return mission. In summary, all missions should undergo similar intense scrutiny with regard to desired science and feasibility, based on available instrumentation (with demonstrated and known capabilities) and cost. 1. P. T. Doran et al. (2004) Earth Sci. Rev. 67, 313-337.

  7. In situ zymography: topographical considerations.

    PubMed

    Mungall, B A; Pollitt, C C

    2001-02-26

    In situ gelatin zymography is a simple technique providing valuable information about the cellular and tissue localization of gelatinases. Until recently, the use of this technique has been confined to soft, relatively homogeneous tissue. In this report in situ zymography has been utilized to assess the sub-lamellar location of gelatinases in the hard, semi-keratinized epidermal layer and the adjacent soft connective tissue matrix of the dermis of the equine hoof. We show that alterations in the orientation at which the tissue is dipped and withdrawn from the emulsion cause profound alterations in emulsion thickness. Microscopic variations in the surface topography of frozen tissue sections also influence emulsion thickness making interpretation of the results difficult. Given these results, researchers must be aware of potential variations in zymographic analysis may be influenced by physical tissue parameters in addition to suspected gelatinase activity. PMID:11245888

  8. DGT as an in situ tool for measuring radiocesium in natural waters.

    PubMed

    Murdock, C; Kelly, M; Chang, L Y; Davison, W; Zhang, H

    2001-11-15

    The application of diffusive gradients in thin-films (DGT) samplers for the measurement of cesium radionuclides in solution, using an ammonium molybdophosphate (AMP) binding agent, was tested under both laboratory and field conditions. In the former they proved able to reproduce known 134Cs concentrations (60 Bq L(-1)) with a high degree of accuracy and precision over periods up to approximately 1 d, in freshwaters over a wide range of pH and temperature, and in saline water. In field trials in a freshwater lake receiving nuclear power station discharges, mean concentrations of 137CS (47-61 mBq L(-1)) were measured over periods from 5 d to 1 month. These agreed, within error, with mean concentrations determined from grab samples but rigorous field validation of long-term (month) deployments of DGT devices proved impossible using conventional sampling procedures, due to loss of 137Cs to container walls. Identified limitations of the DGT technique included probable AMP degradation over longer periods and calibration problems if large changes in temperature and concentration occurred together. Potential limitations due to biofilm growth were considered not to be significant. Despite the limitations, the technique appears to measure concentrations accurately for deployment times of 1 month or less. It has several advantages over traditional sampling methods for monitoring radionuclides in the solution/dissolved phase, including its simplicity, provision of time-averaged mean concentrations, and automatic in-situ concentration onto a medium with ideal counting geometry for gamma spectrometry. PMID:11757612

  9. Integrated in-situ remediation

    SciTech Connect

    Fustos, V.; Lieberman, P.

    1996-01-01

    This article presents an integrated approach to ex-situ and in-situ remediation. A sequence of processes, used successfully in their own right, but used synergistically in this approach, have achieved short-term, economic remediation. In addition the range of contaminants that can be treated is extended. The Process uses ozone, compressed oxygen, water vapor, heat, bioaugmentation and vapor extraction to remediate lower molecular weight hydrocarbons and higher molecular weight hydrocarbons. 3 figs.

  10. Oldest biliary endoprosthesis in situ.

    PubMed

    Consolo, Pierluigi; Scalisi, Giuseppe; Crin, Stefano F; Tortora, Andrea; Giacobbe, Giuseppa; Cintolo, Marcello; Familiari, Luigi; Pallio, Socrate

    2013-07-16

    The advantages of endoscopic retrograde cholangiopancreatography over open surgery have made it the predominant method of treating patients with choledocholithiasis. After sphincterotomy, however, 10%-15% of common bile duct stones cannot be removed with a basket or balloon. The methods for managing "irretrievable stones" include surgery, mechanical lithotripsy, intraductal or extracorporeal shock wave lithotripsy and biliary stenting. The case presented was a referred 82-year-old Caucasian woman with a 7-year-old plastic biliary endoprosthesis in situ. To the best of our knowledge the examined endoprosthesis is the oldest endoprosthesis in situ reported in the literature. Endoscopic biliary endoprosthesis placement remains a simple and safe procedure for patients with stones that are difficult to manage by conventional endoscopic methods and for patients who are unfit for surgery or who are high surgical risks. To date no consensus has been reached regarding how long a biliary prosthesis should remain in situ. Long-term biliary stenting may have a role in selected elderly patients if stones extraction has failed because the procedure may prevent stones impaction and cholangitis. PMID:23858381

  11. Oldest biliary endoprosthesis in situ

    PubMed Central

    Consolo, Pierluigi; Scalisi, Giuseppe; Crin, Stefano F; Tortora, Andrea; Giacobbe, Giuseppa; Cintolo, Marcello; Familiari, Luigi; Pallio, Socrate

    2013-01-01

    The advantages of endoscopic retrograde cholangiopancreatography over open surgery have made it the predominant method of treating patients with choledocholithiasis. After sphincterotomy, however, 10%-15% of common bile duct stones cannot be removed with a basket or balloon. The methods for managing irretrievable stones include surgery, mechanical lithotripsy, intraductal or extracorporeal shock wave lithotripsy and biliary stenting. The case presented was a referred 82-year-old Caucasian woman with a 7-year-old plastic biliary endoprosthesis in situ. To the best of our knowledge the examined endoprosthesis is the oldest endoprosthesis in situ reported in the literature. Endoscopic biliary endoprosthesis placement remains a simple and safe procedure for patients with stones that are difficult to manage by conventional endoscopic methods and for patients who are unfit for surgery or who are high surgical risks. To date no consensus has been reached regarding how long a biliary prosthesis should remain in situ. Long-term biliary stenting may have a role in selected elderly patients if stones extraction has failed because the procedure may prevent stones impaction and cholangitis. PMID:23858381

  12. In-situ Rb-Sr geochronology

    NASA Astrophysics Data System (ADS)

    Anderson, F. S.; Nowicki, K.; Whitaker, T.

    This paper reports on the first rubidium-strontium (Rb-Sr) radiometric dates using a Laser Desorption Resonance Ionization Mass Spectrometry (LDRIMS) instrument capable of being miniaturized for flight to another planet. The LDRIMS instrument produces dates in under 24 hours, requires minimal sample preparation, and avoids the interference and mass resolution issues associated with other geochronology measurements. We have begun testing the bench-top prototype on the Boulder Creek Granite (BCG), from Colorado, comprised primarily of a gneissic quartz monzonite and granodiorite; whole rock Rb-Sr TIMS measurements result in dates of 1700± 40 Ma [1]. Data reduction of the LDRIMS Rb-Sr measurements on calibrated repeat runs result in a date for the BCG of 1.727± 0.087 Ga (n=288, MSWD=1). Most geochronology applications are willing to accept an MSWD up to ~2.7; at MSWD=2, the precision improves to ± 0.062 Ga. This technology is moving from lab prototype to field deployable instrument, and provides an opportunity to directly address the science goals of Mars Sample Return (MSR) within the bounds posed by current scientific, fiscal, and political pressures on the Mars program. Additionally, LDRIMS could potentially be flown to the Moon under the Discovery or New Frontiers program. We posit that in-situ geochronology missions to Mars to triage and validate samples for Mars Sample Return (MSR) are technically feasible in the 2018-2022 time frame.

  13. Noise canceling in-situ detection

    DOEpatents

    Walsh, David O.

    2014-08-26

    Technologies applicable to noise canceling in-situ NMR detection and imaging are disclosed. An example noise canceling in-situ NMR detection apparatus may comprise one or more of a static magnetic field generator, an alternating magnetic field generator, an in-situ NMR detection device, an auxiliary noise detection device, and a computer.

  14. Composite with In Situ Plenums

    NASA Technical Reports Server (NTRS)

    Montesano, Mark

    2012-01-01

    A document describes a high-performance thermal distribution panel (TDP) concept using high-conductivity (greater than 800 W/mK) macro composite skin with in situ heat pipes. The processing technologies proposed to build such a panel result in a one-piece, inseparable assembly with high conductance in both the X and Y planes. The TDP configuration can also be used to produce panels with high structural stiffness. The one-piece construction of the TDP eliminates the thermal interface between the cooling plenums and the heat spreader base, and obviates the need for bulky mounting flanges and thick heat spreaders used on baseline designs. The conductivity of the TDP can be configured to exceed 800 W/mK with a mass density below 2.5 grams per cubic centimeter. This material can provide efficient conductive heat transfer between the in situ heat plenums, permitting the use of thinner panel thicknesses. The plenums may be used as heat pipes, loop heat pipes, or liquid cooling channels. The panel technology used in the TDP is a macro-composite comprised of aluminum-encapsulated annealed pyrolytic graphite (APG). APG is highly aligned crystalline graphite with an in-plane thermal conductivity of 1,700 W/mK. APG has low shear strength and does not constrain the encapsulating material. The proposed concept has no thermal interfaces between the heat pipes and the spreader plate, further improving the overall conductance of the system. The in situ plenums can also be used for liquid cooling applications. The process can be used to fabricate structural panels by adding a second thin sheet.

  15. In Situ Mosaic Brightness Correction

    NASA Technical Reports Server (NTRS)

    Deen, Robert G.; Lorre, Jean J.

    2012-01-01

    In situ missions typically have pointable, mast-mounted cameras, which are capable of taking panoramic mosaics comprised of many individual frames. These frames are mosaicked together. While the mosaic software applies radiometric correction to the images, in many cases brightness/contrast seams still exist between frames. This is largely due to errors in the radiometric correction, and the absence of correction for photometric effects in the mosaic processing chain. The software analyzes the overlaps between adjacent frames in the mosaic and determines correction factors for each image in an attempt to reduce or eliminate these brightness seams.

  16. Cancer statistics: Breast cancer in situ.

    PubMed

    Ward, Elizabeth M; DeSantis, Carol E; Lin, Chun Chieh; Kramer, Joan L; Jemal, Ahmedin; Kohler, Betsy; Brawley, Otis W; Gansler, Ted

    2015-01-01

    An estimated 60,290 new cases of breast carcinoma in situ are expected to be diagnosed in 2015, and approximately 1 in 33 women is likely to receive an in situ breast cancer diagnosis in her lifetime. Although in situ breast cancers are relatively common, their clinical significance and optimal treatment are topics of uncertainty and concern for both patients and clinicians. In this article, the American Cancer Society provides information about occurrence and treatment patterns for the 2 major subtypes of in situ breast cancer in the United States-ductal carcinoma in situ and lobular carcinoma in situ-using data from the North American Association of Central Cancer Registries and the 13 oldest Surveillance, Epidemiology, and End Results registries. The authors also present an overview of in situ breast cancer detection, treatment, risk factors, and prevention and discuss research needs and initiatives. PMID:26431342

  17. Simulations of Terrestrial in-situ Cosmogenic-Nuclide Production

    NASA Technical Reports Server (NTRS)

    Reedy, R. C.; Nishiizumi, K.; Lal, D.; Arnold, J. R.; Englert, P. A. J.; Klein, J.; Middleton, R.; Jull, A. J. T.; Donahue, D. J.

    1994-01-01

    Targets of silicon and silicon dioxide were irradiated with spallation neutrons to simulate the production of long-lived radionuclides in the surface of the Earth. Gamma-ray spectroscopy was used to measure Be-7 and Na-22, and accelerator mass spectrometry was used to measure Be-10, C-14, and Al-26. The measured ratios of these nuclides are compared with calculated ratios and with ratios from other simulations and agree well with ratios inferred from terrestrial samples.

  18. Chemical ionization tandem mass spectrometer for the in situ measurement of methyl hydrogen peroxide

    SciTech Connect

    St Clair, Jason M.; McCabe, David C.; Crounse, John D.; Steiner, Urs; Wennberg, Paul O.

    2010-09-15

    A new approach for measuring gas-phase methyl hydrogen peroxide [(MHP) CH{sub 3}OOH] utilizing chemical ionization mass spectrometry is presented. Tandem mass spectrometry is used to avoid mass interferences that hindered previous attempts to measure atmospheric CH{sub 3}OOH with CF{sub 3}O{sup -} clustering chemistry. CH{sub 3}OOH has been successfully measured in situ using this technique during both airborne and ground-based campaigns. The accuracy and precision for the MHP measurement are a function of water vapor mixing ratio. Typical precision at 500 pptv MHP and 100 ppmv H{sub 2}O is {+-}80 pptv (2 sigma) for a 1 s integration period. The accuracy at 100 ppmv H{sub 2}O is estimated to be better than {+-}40%. Chemical ionization tandem mass spectrometry shows considerable promise for the determination of in situ atmospheric trace gas mixing ratios where isobaric compounds or mass interferences impede accurate measurements.

  19. In-situ spectrophotometric probe

    DOEpatents

    Prather, William S. (2419 Dickey Rd., Augusta, GA 30906)

    1992-01-01

    A spectrophotometric probe for in situ absorption spectra measurements comprising a first optical fiber carrying light from a remote light source, a second optical fiber carrying light to a remote spectrophotometer, the proximal ends of the first and second optical fibers parallel and coterminal, a planoconvex lens to collimate light from the first optical fiber, a reflecting grid positioned a short distance from the lens to reflect the collimated light back to the lens for focussing on the second optical fiber. The lens is positioned with the convex side toward the optical fibers. A substrate for absorbing analyte or an analyte and reagent mixture may be positioned between the lens and the reflecting grid.

  20. In-situ measurement system

    DOEpatents

    Lord, David E. (Livermore, CA)

    1983-01-01

    A multipurpose in situ underground measurement system comprising a plurality of long electrical resistance elements in the form of rigid reinforcing bars, each having an open loop "hairpin" configuration of shorter length than the other resistance elements. The resistance elements are arranged in pairs in a unitized structure, and grouted in place in the underground volume. The electrical resistance of each element and the difference in electrical resistance of the paired elements are obtained, which difference values may be used in analytical methods involving resistance as a function of temperature. A scanner sequentially connects the resistance-measuring apparatus to each individual pair of elements. A source of heating current is also selectively connectable for heating the elements to an initial predetermined temperature prior to electrical resistance measurements when used as an anemometer.

  1. In-situ spectrophotometric probe

    DOEpatents

    Prather, W.S.

    1992-12-15

    A spectrophotometric probe is described for in situ absorption spectra measurements comprising a first optical fiber carrying light from a remote light source, a second optical fiber carrying light to a remote spectrophotometer, the proximal ends of the first and second optical fibers parallel and co-terminal, a planoconvex lens to collimate light from the first optical fiber, a reflecting grid positioned a short distance from the lens to reflect the collimated light back to the lens for focusing on the second optical fiber. The lens is positioned with the convex side toward the optical fibers. A substrate for absorbing analyte or an analyte and reagent mixture may be positioned between the lens and the reflecting grid. 5 figs.

  2. Distribution of natural and anthropogenic radionuclides in soil and beach sand samples of Kalpakkam (India) using hyper pure germanium (HPGe) gamma ray spectrometry.

    PubMed

    Kannan, V; Rajan, M P; Iyenga, M A R; Ramesh, R

    2002-07-01

    Pre-operational survey at Kalpakkam coast, indicated elevated gamma background radiation levels in the range of 100-4000 nGy h(-1) over the large tracts of the coastal sands due to the presence of pockets of monazite mineral in beach sands. In view of the prevalence of monazite, a systematic gamma spectrometric study of distribution of natural radionuclides in soil and beach sand samples collected from the terrestrial and coastal environment of Kalpakkam was performed and concentrations of primordial radionuclides such as 238U, 232Th and 40K and anthropogenic radionuclide 137Cs were determined. The concentrations of 238U, 232Th and 40K in soil samples were 5-71, 15-776 and 200-854 Bq kg(-1) dry, respectively. In beach sand samples, 238U, 232Th and 40K contents varied in the range of 36-258, 352-3872 and 324-405 Bq kg(-1) dry, respectively. The total absorbed gamma dose rate in air due to the presence of 238U, 232Th and 40K in Kalpakkam soil samples varied between 24 and 556 nGy h(-1) with a mean of 103 nGy h(-1). The contribution to the total absorbed gamma dose rate in air in the decreasing order was due to the presence of 232Th (76.4%), followed by 40K (16.9%) and 238U (6.7%) in Kalpakkam soils. However, in beach areas of Kalpakkam, the presence of 232Th in beach sand contributed maximum (94.0%) to the total absorbed gamma dose rate in air followed by 238U (4.7%) and minimum contribution was by 40K (1.3%). 137Cs in Kalpakkam soils ranged from < or = 1.0 to 2.8 Bq kg(-1) dry, which was 1-3 order of magnitude less than the concentration of primordial radionuclides in soil. PMID:12137019

  3. Training for teamwork through in situ simulations

    PubMed Central

    Sorensen, Asta; Poehlman, Jon; Bollenbacher, John; Riggan, Scott; Davis, Stan; Miller, Kristi; Ivester, Thomas; Kahwati, Leila

    2015-01-01

    In situ simulations allow healthcare teams to practice teamwork and communication as well as clinical management skills in a team's usual work setting with typically available resources and equipment. The purpose of this video is to demonstrate how to plan and conduct in situ simulation training sessions, with particular emphasis on how such training can be used to improve communication and teamwork. The video features an in situ simulation conducted at a labour and delivery unit in response to postpartum hemorrhage. PMID:26294962

  4. The Tensions of In Situ Visualization.

    PubMed

    Moreland, Kenneth

    2016-01-01

    In situ visualization is the coupling of visualization software with a simulation or other data producer to process the data "in memory" before the data are offloaded to a storage system. Although in situ visualization provides superior analysis, it has implementation tradeoffs resulting from conflicts with some traditional expected requirements. Numerous conflicting requirements create tensions that lead to difficult implementation tradeoffs. This article takes a look at the most prevailing tensions of in situ visualization. PMID:26960023

  5. Amplification of chromosomal DNA in situ

    DOEpatents

    Christian, Allen T.; Coleman, Matthew A.; Tucker, James D.

    2002-01-01

    Amplification of chromosomal DNA in situ to increase the amount of DNA associated with a chromosome or chromosome region is described. The amplification of chromosomal DNA in situ provides for the synthesis of Fluorescence in situ Hybridization (FISH) painting probes from single dissected chromosome fragments, the production of cDNA libraries from low copy mRNAs and improved in Comparative Genomic Hybridization (CGH) procedures.

  6. The architecture of outer dynein arms in situ.

    PubMed

    Ishikawa, Takashi; Sakakibara, Hitoshi; Oiwa, Kazuhiro

    2007-05-18

    Outer dynein arms, the force generators for axonemal motion, form arrays on microtubule doublets in situ, although they are bouquet-like complexes with separated heads of multiple heavy chains when isolated in vitro. To understand how the three heavy chains are folded in the array, we reconstructed the detailed 3D structure of outer dynein arms of Chlamydomonas flagella in situ by electron cryo-tomography and single-particle averaging. The outer dynein arm binds to the A-microtubule through three interfaces on two adjacent protofilaments, two of which probably represent the docking complex. The three AAA rings of heavy chains, seen as stacked plates, are connected in a striking manner on microtubule doublets. The tail of the alpha-heavy chain, identified by analyzing the oda11 mutant, which lacks alpha-heavy chain, extends from the AAA ring tilted toward the tip of the axoneme and towards the inside of the axoneme at 50 degrees , suggesting a three-dimensional power stroke. The neighboring outer dynein arms are connected through two filamentous structures: one at the exterior of the axoneme and the other through the alpha-tail. Although the beta-tail seems to merge with the alpha-tail at the internal side of the axoneme, the gamma-tail is likely to extend at the exterior of the axoneme and join the AAA ring. This suggests that the fold and function of gamma-heavy chain are different from those of alpha and beta-chains. PMID:17391698

  7. Method for in situ combustion

    DOEpatents

    Pasini, III, Joseph; Shuck, Lowell Z.; Overbey, Jr., William K.

    1977-01-01

    This invention relates to an improved in situ combustion method for the recovery of hydrocarbons from subterranean earth formations containing carbonaceous material. The method is practiced by penetrating the subterranean earth formation with a borehole projecting into the coal bed along a horizontal plane and extending along a plane disposed perpendicular to the plane of maximum permeability. The subterranean earth formation is also penetrated with a plurality of spaced-apart vertical boreholes disposed along a plane spaced from and generally parallel to that of the horizontal borehole. Fractures are then induced at each of the vertical boreholes which project from the vertical boreholes along the plane of maximum permeability and intersect the horizontal borehole. The combustion is initiated at the horizontal borehole and the products of combustion and fluids displaced from the earth formation by the combustion are removed from the subterranean earth formation via the vertical boreholes. Each of the vertical boreholes are, in turn, provided with suitable flow controls for regulating the flow of fluid from the combustion zone and the earth formation so as to control the configuration and rate of propagation of the combustion zone. The fractures provide a positive communication with the combustion zone so as to facilitate the removal of the products resulting from the combustion of the carbonaceous material.

  8. In situ bioremediation in Europe

    SciTech Connect

    Porta, A.; Young, J.K.; Molton, P.M.

    1993-06-01

    Site remediation activity in Europe is increasing, even if not at the forced pace of the US. Although there is a better understanding of the benefits of bioremediation than of other approaches, especially about in situ bioremediation of contaminated soils, relatively few projects have been carried out full-scale in Europe or in the US. Some engineering companies and large industrial companies in Europe are investigating bioremediation and biotreatment technologies, in some cases to solve their internal waste problems. Technologies related to the application of microorganisms to the soil, release of nutrients into the soil, and enhancement of microbial decontamination are being tested through various additives such as surfactants, ion exchange resins, limestone, or dolomite. New equipment has been developed for crushing and mixing or injecting and sparging the microorganisms, as have new reactor technologies (e.g., rotating aerator reactors, biometal sludge reactors, and special mobile containers for simultaneous storage, transportation, and biodegradation of contaminated soil). Some work has also been done with immobilized enzymes to support and restore enzymatic activities related to partial or total xenobiotic decontamination. Finally, some major programs funded by public and private institutions confirm that increasing numbers of firms have a working interest in bioremediation.

  9. ENGINEERING BULLETIN: IN SITU STEAM EXTRACTION TREATMENT

    EPA Science Inventory

    In situ steam extraction removes volatile and semivolatile hazardous contaminants from soil and groundwater without excavation of the hazardous waste. Waste constituents are removed in situ by the technology and are not actually treated. The use of steam enhances the stripping of...

  10. In Situ Analytical Electron Microscopy for Probing Nanoscale Electrochemistry

    SciTech Connect

    Graetz J.; Meng, Y.S.; McGilvray, T.; Yang, M.-C.; Gostovic, D.; Wang, F.; Zeng, D.; Zhu, Y.

    2011-10-31

    Oxides and their tailored structures are at the heart of electrochemical energy storage technologies and advances in understanding and controlling the dynamic behaviors in the complex oxides, particularly at the interfaces, during electrochemical processes will catalyze creative design concepts for new materials with enhanced and better-understood properties. Such knowledge is not accessible without new analytical tools. New innovative experimental techniques are needed for understanding the chemistry and structure of the bulk and interfaces, more importantly how they change with electrochemical processes in situ. Analytical Transmission Electron Microscopy (TEM) is used extensively to study electrode materials ex situ and is one of the most powerful tools to obtain structural, morphological, and compositional information at nanometer scale by combining imaging, diffraction and spectroscopy, e.g., EDS (energy dispersive X-ray spectrometry) and Electron Energy Loss Spectrometry (EELS). Determining the composition/structure evolution upon electrochemical cycling at the bulk and interfaces can be addressed by new electron microscopy technique with which one can observe, at the nanometer scale and in situ, the dynamic phenomena in the electrode materials. In electrochemical systems, for instance in a lithium ion battery (LIB), materials operate under conditions that are far from equilibrium, so that the materials studied ex situ may not capture the processes that occur in situ in a working battery. In situ electrochemical operation in the ultra-high vacuum column of a TEM has been pursued by two major strategies. In one strategy, a 'nano-battery' can be fabricated from an all-solid-state thin film battery using a focused ion beam (FIB). The electrolyte is either polymer based or ceramic based without any liquid component. As shown in Fig. 1a, the interfaces between the active electrode material/electrolyte can be clearly observed with TEM imaging, in contrast to the composite electrodes/electrolyte interfaces in conventional lithium ion batteries, depicted in Fig.1b, where quantitative interface characterization is extremely difficult if not impossible. A second strategy involves organic electrolyte, though this approach more closely resembles the actual operation conditions of a LIB, the extreme volatility In Situ Analytical Electron Microscopy for Probing Nanoscale Electrochemistry by Ying Shirley Meng, Thomas McGilvray, Ming-Che Yang, Danijel Gostovic, Feng Wang, Dongli Zeng, Yimei Zhu, and Jason Graetz of the organic electrolytes present significant challenges for designing an in situ cell that is suitable for the vacuum environment of the TEM. Significant progress has been made in the past few years on the development of in situ electron microscopy for probing nanoscale electrochemistry. In 2008, Brazier et al. reported the first cross-section observation of an all solid-state lithium ion nano-battery by TEM. In this study the FIB was used to make a 'nano-battery,' from an all solid-state battery prepared by pulsed laser deposition (PLD). In situ TEM observations were not possible at that time due to several key challenges such as the lack of a suitable biasing sample holder and vacuum transfer of sample. In 2010, Yamamoto et al. successfully observed changes of electric potential in an all-solid-state lithium ion battery in situ with electron holography (EH). The 2D potential distribution resulting from movement of lithium ions near the positive-electrode/electrolyte interface was quantified. More recently Huang et al. and Wang et al. reported the in situ observations of the electrochemical lithiation of a single SnO{sub 2} nanowire electrode in two different in situ setups. In their approach, a vacuum compatible ionic liquid is used as the electrolyte, eliminating the need for complicated membrane sealing to prevent the evaporation of carbonate based organic electrolyte into the TEM column. One main limitation of this approach is that EELS spectral imaging is not possible due to the high plasmon signal of the ionic liquid. To this end, we have developed a novel in situ instrumental system combining analytical electron microscopy with advanced spectroscopy to probe the dynamic phenomena in an all solid-state nano-battery. In situ electron microscopy is a versatile technique that yields insights into challenging questions that could not be obtained using other techniques. However, in order to fully exploit the capabilities, a very carefully thought-out plan of action is essential. It is important to recognize that this is not just a simple characterization tool, but a collection of tools that make up a complete experimental set-up: the choice of FIB operation conditions, specimen holder for biasing, grid materials and design as well as microscope environment must be thoroughly considered before performing an experiment.

  11. Toward the next TRL of KArLE (in situ geochronology for planetary experiment)

    NASA Astrophysics Data System (ADS)

    Devismes, D.; Cohen, B. A.; Haight, H.

    2015-10-01

    The instrument 'Potassium (K) Argon Laser Experiment' (KArLE) is developed and designed for in situ absolute dating of rocks on planetary surfaces. It is based on the K-Ar dating method and uses the Laser Induced Breakdown Spectroscopy - Laser Ablation - Quadrupole Mass Spectrometry (LIBSLA- QMS) technique. We use a dedicated interface to combine two instruments similar to SAM of Mars Science Laboratory (for the QMS) and ChemCam (for the LA and LIBS). The prototype has demonstrated that KArLE is a suitable and promising instrument for in situ absolute dating.

  12. Frontiers of in situ electron microscopy

    DOE PAGESBeta

    Zheng, Haimei; Zhu, Yimei; Meng, Shirley Ying

    2015-01-01

    In situ transmission electron microscopy (TEM) has become an increasingly important tool for materials characterization. It provides key information on the structural dynamics of a material during transformations and the correlation between structure and properties of materials. With the recent advances in instrumentation, including aberration corrected optics, sample environment control, the sample stage, and fast and sensitive data acquisition, in situ TEM characterization has become more and more powerful. In this article, a brief review of the current status and future opportunities of in situ TEM is included. It also provides an introduction to the six articles covered by inmore » this issue of MRS Bulletin explore the frontiers of in situ electron microscopy, including liquid and gas environmental TEM, dynamic four-dimensional TEM, nanomechanics, ferroelectric domain switching studied by in situ TEM, and state-of-the-art atomic imaging of light elements (i.e., carbon atoms) and individual defects.« less

  13. Multiple NEO Rendezvous, Reconnaissance and In Situ Exploration

    NASA Astrophysics Data System (ADS)

    Klaus, K.; Elsperman, M. S.; Cook, T.; Smith, D.

    2010-12-01

    We propose a two spacecraft mission (Mother Ship and Small Body Lander) rendezvous with multiple Near Earth Objects (NEO). This two spacecraft mission mimics the likely architecture approach that human explorers will use: a mother ship(MS) designed to get from Earth to the NEO and a Small Body Lander(SBL) that performs in situ investigation on or close to the NEOs surface. The MS carries the SBL to the target NEO. Once at the target NEO, the MS conducts an initial reconnaissance in order to produce a high resolution map of the surface. This map is used to identify coordinates of interest which are sent to the SBL. The SBL un-docks from the MS to rendezvous with the NEO and collect data. Landings are possible, though the challenges of anchoring to the NEO surface are significant. The SBL design is flexible and adaptable, enabling science data collection on or near the surface. After surface investigations are completed on the first NEO, the SBL will return and autonomously rendezvous and dock with the MS. The MS then goes to the next NEO target. During transit to the next NEO, the SBL could be refueled by the MS, a TRL8 capability demonstrated on the DARPA/NASA Orbital Express mission in 2007, or alternately sized to operate without requiring refueling depending on the mission profile. The mission goals are to identify surface hazards; quantify engineering boundary conditions for future human visits, and identify resources for future exploitation. The mission goals will be accomplished through the execution of key mission objectives: (1) high-resolution surface topography; (2) surface composition and mineralogy; (3) radiation environment near NEO; and (4) mechanical properties of the surface. Essential SBL instruments include: a) LIDAR (Obj. 1); b) 3D, high- resolution hyperspectral imaging cameras (Obj. 2); c) radiation sensor package (Obj. 3); and d) strain gauges (Obj. 4). Additional or alternative instruments could include: e) x-ray fluorescence or laser-induced breakdown spectroscopy (LIBS) sensor package (Obj. 2); f) gamma ray/neutron spectrometry package (Obj. 2); and g) radiometer package (to address variations in thermal environment). The ability to reach, survey, sample, and analyze multiple NEOs at close proximity is an enormous capability that can enable NASA to rapidly achieve the primary Exploration Precursor Robotic Mission (xPRM) Program goal of characterizing NEOs for future human exploration. Instead of launching multiple dedicated missions to each NEO of interest, a multi-NEO sortie mission can be planned and executed to achieve the same mission objectives with one launch, dramatically reducing the cost of NEO exploration. Collectively, our NEO Exploration System Architecture provides solutions for a wide variety of exploration activities using a common spacecraft bus and common core instrumentation for the spacecraft. This engineering consistency will substantially improve the probability of mission success, increase the likelihood of maintaining an aggressive launch schedule, and decrease the total cost of multiple missions. NASA successfully used this approach with the robotic precursors leading up to the Apollo missions, and we see significant benefits from this same programmatic approach for the xPRM program.

  14. In situ bioremediation using horizontal wells

    SciTech Connect

    1995-04-01

    In Situ Bioremediation (ISB), which is the term used in this report for Gaseous Nutrient Injection for In Situ Bioremediation, remediates soils and ground water contaminated with volatile organic compounds (VOCs) both above and below the water table. ISB involves injection of air and nutrients (sparging and biostimulation) into the ground water and vacuum extraction to remove .VOCs from the vadose zone concomitant with biodegradation of VOCs. The innovation is in the combination of 3 emerging technologies, air stripping, horizontal wells, and bioremediation via gaseous nutrient injection with a baseline technology, soil vapor extraction, to produce a more efficient in situ remediation system.

  15. Potential of natural gamma-ray spectrometry for mapping and environmental monitoring of black-sand beach deposits on the northern coast of Sinai, Egypt.

    PubMed

    Aboelkhair, Hatem; Zaaeimah, Mostafa

    2013-04-01

    The concentrations and distributions of naturally occurring radioactive materials were studied with the aim of detecting and mapping radioactive anomalies as well as monitoring the environment for black-sand beach deposits in Northern Sinai, Egypt. For this purpose, ground gamma-ray spectrometric surveys were conducted using a portable GS-512 spectrometer, with an NaI (Tl) detector, on an area 77.5 km(2) in surface area located between the cities of Rafah and Elareish on the Mediterranean Sea coast. The results revealed that the black-sand beach deposits could be differentiated according to their total-count (TC) radioactivity into five normally distributed interpreted radiometric lithologic (IRL) units denoted by U1, U2, U3, U4 and U5. The computed characteristic TC radiometric statistics of these five IRL units range from 4.67  to 9.96 Ur for their individual arithmetic means. The computed arithmetic means for the three radioelements K, eU and eTh reach 0.46 %, 2.25 and 6.17 ppm, respectively for the whole study area. Monitoring the environmental effects of radioelement concentrations on the study area showed that the mean natural equivalent radiation dose rate from the terrestrial gamma-radiation of the whole area attains 0.33 mSv y(-1). This average value remains on the safe side and within the maximum permissible safe radiation dose (<1.0 mSv y(-1)) without harm to the individual, except at three scattered points reaching more than these values. Some of the local inhabitants in the region sometimes use black sands as a building material. Consequently, they are not recommended for use as building materials, because the inhabitants will, then, receive a relatively high radioactive dose generated mainly by monazite and zircon minerals, two of the main constituents of black sands. PMID:22869819

  16. In-situ characterization technique for screening contaminated soils

    SciTech Connect

    Jaselskis, E.J.; Anderson, M.S.; D`Silva, A.P.; Baldwin, D.P.; Zamzow, D.S.

    1995-07-01

    An innovative field sampling system for screening contaminated soils has been developed using laser ablation coupled with inductively coupled plasma-atomic emission spectrometry (LA-ICP-AES) technology. This sampling approach provides in-situ real-time analysis of trace inorganic elements and is conducted through a mobile testing facility that consists of an instrumentation vehicle called the Mobile Demonstration Laboratory for Environmental Screening Technologies (MDLEST) and an attached trailer called the Robotic Sampling Accessory (RSA). The RSA provides automated sampling capabilities through an attached three-degree-of-freedom robot that is equipped with a surface-sampling probe. The MDLEST-RSA was successfully tested at a Department of Energy (DOE) site in Fernald, Ohio, during the fall of 1992. This paper provides a description of the analysis technique, the MDLEST and RSA, and results of the field demonstration. In addition, benefits, limitations, and future plans are also discussed.

  17. Toward In Situ Monitoring of Water Contamination by Nitroenergetic Compounds

    PubMed Central

    Johnson, Brandy J.; Leska, Iwona A.; Medina, Alejandro; Dyson, Norris F.; Nasir, Mansoor; Melde, Brian J.; Taft, Jenna R.; Charles, Paul T.

    2012-01-01

    We have previously described the application of novel porous organosilicate materials to the preconcentration of nitroenergetic targets from aqueous solution prior to HPLC analysis. The performance of the sorbents and the advantages of these types of materials over commercially available solid phase extraction sorbents have been demonstrated. Here, the development of systems for application of those sorbents to in situ monitoring is described. Considerations such as column pressure, particulate filtration, and component durability are discussed. The diameter of selected column housings, the sorbent bed depth, and the frits utilized significantly impact the utility of the sorbent columns in the prototype system. The impact of and necessity for improvements in the morphological characteristics of the sorbents as they relate to reduction in column pressure are detailed. The results of experiments utilizing a prototype system are presented. Data demonstrating feasibility for use of the sorbents in preconcentration prior to ion mobility spectrometry is also presented. PMID:23202195

  18. Lithographically fabricated silicon microreactor for in situ characterization of heterogeneous catalysts—Enabling correlative characterization techniques

    SciTech Connect

    Baier, S.; Rochet, A.; Hofmann, G.; Kraut, M.; Grunwaldt, J.-D.

    2015-06-15

    We report on a new modular setup on a silicon-based microreactor designed for correlative spectroscopic, scattering, and analytic on-line gas investigations for in situ studies of heterogeneous catalysts. The silicon microreactor allows a combination of synchrotron radiation based techniques (e.g., X-ray diffraction and X-ray absorption spectroscopy) as well as infrared thermography and Raman spectroscopy. Catalytic performance can be determined simultaneously by on-line product analysis using mass spectrometry. We present the design of the reactor, the experimental setup, and as a first example for an in situ study, the catalytic partial oxidation of methane showing the applicability of this reactor for in situ studies.

  19. Lithographically fabricated silicon microreactor for in situ characterization of heterogeneous catalystsEnabling correlative characterization techniques

    NASA Astrophysics Data System (ADS)

    Baier, S.; Rochet, A.; Hofmann, G.; Kraut, M.; Grunwaldt, J.-D.

    2015-06-01

    We report on a new modular setup on a silicon-based microreactor designed for correlative spectroscopic, scattering, and analytic on-line gas investigations for in situ studies of heterogeneous catalysts. The silicon microreactor allows a combination of synchrotron radiation based techniques (e.g., X-ray diffraction and X-ray absorption spectroscopy) as well as infrared thermography and Raman spectroscopy. Catalytic performance can be determined simultaneously by on-line product analysis using mass spectrometry. We present the design of the reactor, the experimental setup, and as a first example for an in situ study, the catalytic partial oxidation of methane showing the applicability of this reactor for in situ studies.

  20. Lithographically fabricated silicon microreactor for in situ characterization of heterogeneous catalystsEnabling correlative characterization techniques.

    PubMed

    Baier, S; Rochet, A; Hofmann, G; Kraut, M; Grunwaldt, J-D

    2015-06-01

    We report on a new modular setup on a silicon-based microreactor designed for correlative spectroscopic, scattering, and analytic on-line gas investigations for in situ studies of heterogeneous catalysts. The silicon microreactor allows a combination of synchrotron radiation based techniques (e.g., X-ray diffraction and X-ray absorption spectroscopy) as well as infrared thermography and Raman spectroscopy. Catalytic performance can be determined simultaneously by on-line product analysis using mass spectrometry. We present the design of the reactor, the experimental setup, and as a first example for an in situ study, the catalytic partial oxidation of methane showing the applicability of this reactor for in situ studies. PMID:26133867

  1. Mass spectrometry.

    NASA Technical Reports Server (NTRS)

    Burlingame, A. L.; Johanson, G. A.

    1972-01-01

    Review of the current state of mass spectrometry, indicating its unique importance for advanced scientific research. Mass spectrometry applications in computer techniques, gas chromatography, ion cyclotron resonance, molecular fragmentation and ionization, and isotope labeling are covered. Details are given on mass spectrometry applications in bio-organic chemistry and biomedical research. As the subjects of these applications are indicated alkaloids, carbohydrates, lipids, terpenes, quinones, nucleic acid components, peptides, antibiotics, and human and animal metabolisms. Particular attention is given to the mass spectra of organo-inorganic compounds, inorganic mass spectrometry, surface phenomena such as secondary ion and electron emission, and elemental and isotope analysis. Further topics include mass spectrometry in organic geochemistry, applications in geochronology and cosmochemistry, and organic mass spectrometry.

  2. ENHANCED BIODEGRADATION THROUGH IN-SITU AERATION

    EPA Science Inventory

    This presentation provided an overview of enhanced aerobic bioremediation using in-situ aeration or venting. The following topics were covered: (1) Basic discussion on biodegradation and respiration testing; (2) Basic discussion on volatilization, rate-limited mass transport, an...

  3. Direct in situ rt-PCR.

    PubMed

    Lossi, Laura; Gambino, Graziana; Salio, Chiara; Merighi, Adalberto

    2011-01-01

    In situ polymerase chain reaction (PCR) is a histological technique that exploits the advantages of PCR for detection of mRNA directly in tissue sections. It somehow conjugates together PCR and in situ hybridization that is more traditionally employed for mRNA localization in cell organelles, intact cells, or tissue sections. This chapter describes the application of in situ PCR for neuropeptide mRNA localization. We provide here a detailed protocol for direct in situ reverse transcription (RT) PCR (RT-PCR) with nonradioactive probes after fixation and paraffin embedding or cryosectioning. Digoxigenin-labeled nucleotides (digoxigenin-11-dUTP) are incorporated in the PCR product after RT and subsequently detected with an anti-digoxigenin antibody conjugated with alkaline phosphatase. The procedure can be modified for use with fluorescent probes and employed in combination with enzyme/fluorescence immunocytochemical labeling. PMID:21922403

  4. 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

  5. Gum containing calcium fluoride reinforces enamel subsurface lesions in situ.

    PubMed

    Kitasako, Y; Sadr, A; Hamba, H; Ikeda, M; Tagami, J

    2012-04-01

    The aim of this study was to assess the effect of chewing gum containing phosphoryl oligosaccharides of calcium (POs-Ca) and a low concentration of fluoride (F) on the hardness of enamel subsurface lesions, utilizing a double-blind, randomized, and controlled in situ model. Fifteen individuals wore removable lingual appliances with 3 bovine-enamel insets containing subsurface demineralized lesions. Three times a day for 14 days, they chewed one of the 3 chewing gums (placebo, POs-Ca, POs-Ca+F). After the treatment period, cross-sectional mineral content, nanoindentation hardness, and fluoride ion mapping by time-of-flight secondary ion mass spectrometry (TOF-SIMS) were evaluated. Although there were no statistical differences in overall mineral content and hardness recovery rates between POs-Ca and POs-Ca+F subsurface lesions (p > 0.05), nanoindentation at 1-μm distance increments from the surface showed statistical differences in hardness recovery rate between POs-Ca and POs-Ca+F in the superficial 20-μm region (p < 0.05). Fluoride mapping revealed distribution of the ion up to 20 μm from the surface in the POs-Ca+F group. Nanoindentation and TOF-SIMS results highlighted the benefits of bioavailability of fluoride ion on reinforcement of the superficial zone of subsurface lesions in situ (NCT01377493). PMID:22337700

  6. Cancer Cell Imaging Using in Situ Generated Gold Nanoclusters.

    PubMed

    Chattoraj, Shyamtanu; Amin, Md Asif; Mohapatra, Saswat; Ghosh, Surajit; Bhattacharyya, Kankan

    2016-01-01

    In situ generated fluorescent gold nanoclusters (Au-NCs) are used for bio-imaging of three human cancer cells, namely, lung (A549), breast (MCF7), and colon (HCT116), by confocal microscopy. The amount of Au-NCs in non-cancer cells (WI38 and MCF10A) is 20-40 times less than those in the corresponding cancer cells. The presence of a larger amount of glutathione (GSH) capped Au-NCs in the cancer cell is ascribed to a higher glutathione level in cancer cells. The Au-NCs exhibit fluorescence maxima at 490-530?nm inside the cancer cells. The fluorescence maxima and matrix-assisted laser desorption ionization (MALDI) mass spectrometry suggest that the fluorescent Au-NCs consist of GSH capped clusters with a core structure (Au8-13 ). Time-resolved confocal microscopy indicates a nanosecond (1-3?ns) lifetime of the Au-NCs inside the cells. This rules out the formation of aggregated Au-thiolate complexes, which typically exhibit microsecond (?1000?ns) lifetimes. Fluorescence correlation spectroscopy (FCS) in live cells indicates that the size of the Au-NCs is ?1-2?nm. For in situ generation, we used a conjugate consisting of a room-temperature ionic liquid (RTIL, [pmim][Br]) and HAuCl4 . Cytotoxicity studies indicate that the conjugate, [pmim][AuCl4 ], is non-toxic for both cancer and non-cancer cells. PMID:26437799

  7. Non-destructive in-situ method and apparatus for determining radionuclide depth in media

    DOEpatents

    Xu, X. George; Naessens, Edward P.

    2003-01-01

    A non-destructive method and apparatus which is based on in-situ gamma spectroscopy is used to determine the depth of radiological contamination in media such as concrete. An algorithm, Gamma Penetration Depth Unfolding Algorithm (GPDUA), uses point kernel techniques to predict the depth of contamination based on the results of uncollided peak information from the in-situ gamma spectroscopy. The invention is better, faster, safer, and/cheaper than the current practice in decontamination and decommissioning of facilities that are slow, rough and unsafe. The invention uses a priori knowledge of the contaminant source distribution. The applicable radiological contaminants of interest are any isotopes that emit two or more gamma rays per disintegration or isotopes that emit a single gamma ray but have gamma-emitting progeny in secular equilibrium with its parent (e.g., .sup.60 Co, .sup.235 U, and .sup.137 Cs to name a few). The predicted depths from the GPDUA algorithm using Monte Carlo N-Particle Transport Code (MCNP) simulations and laboratory experiments using .sup.60 Co have consistently produced predicted depths within 20% of the actual or known depth.

  8. Chemoenzymatic Synthesis of Acyl Coenzyme A Substrates Enables in Situ Labeling of Small Molecules and Proteins.

    PubMed

    Agarwal, Vinayak; Diethelm, Stefan; Ray, Lauren; Garg, Neha; Awakawa, Takayoshi; Dorrestein, Pieter C; Moore, Bradley S

    2015-09-18

    A chemoenzymatic approach to generate fully functional acyl coenzyme A molecules that are then used as substrates to drive in situ acyl transfer reactions is described. Mass spectrometry based assays to verify the identity of acyl coenzyme A enzymatic products are also illustrated. The approach is responsive to a diverse array of carboxylic acids that can be elaborated to their corresponding coenzyme A thioesters, with potential applications in wide-ranging chemical biology studies that utilize acyl coenzyme A substrates. PMID:26333306

  9. Investigation of (235)U, (226)Ra, (232)Th, (40)K, (137)Cs, and heavy metal concentrations in Anzali international wetland using high-resolution gamma-ray spectrometry and atomic absorption spectroscopy.

    PubMed

    Zare, Mohammad Reza; Kamali, Mahdi; Fallahi Kapourchali, Maryam; Bagheri, Hashem; Khoram Bagheri, Mahdi; Abedini, Ali; Pakzad, Hamid Reza

    2016-02-01

    Measurements of natural radioactivity levels and heavy metals in sediment and soil samples of the Anzali international wetland were carried out by two HPGe-gamma ray spectrometry and atomic absorption spectroscopy techniques. The concentrations of (235)U, (226)Ra, (232)Th, (40)K, and (137)Cs in sediment samples ranged between 1.05??0.51-5.81??0.61, 18.06??0.63-33.36??.0.34, 17.57??0.38-45.84??6.23, 371.88??6.36-652.28??11.60, and 0.43??0.06-63.35??0.94Bq/kg, while in the soil samples they vary between 2.36-5.97, 22.71-38.37, 29.27-42.89, 472.66-533, and 1.05-9.60Bq/kg for (235)U, (226)Ra, (232)Th, (40)K, and (137)Cs, respectively. Present results are compared with the available literature data and also with the world average values. The radium equivalent activity was well below the defined limit of 370Bq/kg. The external hazard indices were found to be less than 1, indicating a low dose. Heavy metal concentrations were found to decrease in order as Fe?>?Mn?>?Sr?>?Zn?>?Cu?>?Cr?>?Ni?>?Pb?>?Co?>?Cd. These measurements will serve as background reference levels for the Anzali wetland. PMID:26490904

  10. DOE In Situ Remediation Integrated Program. In situ manipulation technologies subprogram plan

    SciTech Connect

    Yow, J.L. Jr.

    1993-12-22

    The In Situ Remediation Integrated Program (ISRP) supports and manages a balanced portfolio of applied research and development activities in support of DOE environmental restoration and waste management needs. ISRP technologies are being developed in four areas: containment, chemical and physical treatment, in situ bioremediation, and in situ manipulation (including electrokinetics). the focus of containment is to provide mechanisms to stop contaminant migration through the subsurface. In situ bioremediation and chemical and physical treatment both aim to destroy or eliminate contaminants in groundwater and soils. In situ manipulation (ISM) provides mechanisms to access contaminants or introduce treatment agents into the soil, and includes other technologies necessary to support the implementation of ISR methods. Descriptions of each major program area are provided to set the technical context of the ISM subprogram. Typical ISM needs for major areas of in situ remediation research and development are identified.

  11. [In situ gene amplification on tissue sections (in situ PCR). A new technique for pathologists].

    PubMed

    Walker, F; Bedel, C; Boucher, O; Dauge, M C; Vissuzaine, C; Potet, F

    1995-01-01

    In situ polymerase chain reaction is a recent technique which combines the sensitivity of PCR reaction to intracellular localization of genomic sequences with the same specificity as in situ hybridization. This reaction is based on the in situ annealing and polymerisation of oligonucleotides complementary to nucleotides located at each side of the target DNA sequence to amplify. We describe the Hot Start PCR (DNA) and the Hot Start PCR after reverse transcription step (RNA). It allows to amplify some nucleic sequences to a high level, becoming easier to detect. The vizualisation can be realized by direct in situ PCR, the product obtained being directly identifiable by incorporation of labeled nucleotides or primers, or preferentially by indirect in situ PCR. In this case, the amplification is followed by in situ hybridization with labeled probes. This last procedure is more specific. Numerous controls are essential at each step of the technique for validating results. PMID:8720848

  12. Calibration curves for biological dosimetry by fluorescence in situ hybridisation.

    PubMed

    Stronati, L; Durante, M; Gensabella, G; Gialanella, G; Gross, G F; Pugliese, M; Scampoli, P; Sgura, A; Testa, A; Tanzarella, C

    2001-01-01

    Dose-response curves were measured for the induction of chromosomal aberrations in peripheral blood lymphocytes after acute exposure in vitro to 60Co gamma rays. Blood was obtained from four different healthy donors, and chromosomes were either observed at metaphase, following colcemid accumulation, or prematurely condensed by calyculin A. Cells were analysed in three different Italian laboratories. Chromosomes 1, 2, and 4 were painted, and simple-type interchanges between painted and non-painted chromosomes were scored in cells exposed in the dose range 0.1-3.0 Gy. The chemical-induced premature chromosome condensation method was also used combined with chromosome painting (chromosome 4 only) to determine calibration curves for high dose exposures (up to 20 Gy X rays). Calibration curves described in this paper will be used in our laboratories for biological dosimetry by fluorescence in situ hybridisation. PMID:11499437

  13. Radiation resistance of sequencing chips for in situ life detection.

    PubMed

    Carr, Christopher E; Rowedder, Holli; Lui, Clarissa S; Zlatkovsky, Ilya; Papalias, Chris W; Bolander, Jarie; Myers, Jason W; Bustillo, James; Rothberg, Jonathan M; Zuber, Maria T; Ruvkun, Gary

    2013-06-01

    Life beyond Earth may be based on RNA or DNA if such life is related to life on Earth through shared ancestry due to meteoritic exchange, such as may be the case for Mars, or if delivery of similar building blocks to habitable environments has biased the evolution of life toward utilizing nucleic acids. In this case, in situ sequencing is a powerful approach to identify and characterize such life without the limitations or expense of returning samples to Earth, and can monitor forward contamination. A new semiconductor sequencing technology based on sensing hydrogen ions released during nucleotide incorporation can enable massively parallel sequencing in a small, robust, optics-free CMOS chip format. We demonstrate that these sequencing chips survive several analogues of space radiation at doses consistent with a 2-year Mars mission, including protons with solar particle event-distributed energy levels and 1 GeV oxygen and iron ions. We find no measurable impact of irradiation at 1 and 5 Gy doses on sequencing quality nor on low-level hardware characteristics. Further testing is required to study the impacts of soft errors as well as to characterize performance under neutron and gamma irradiation and at higher doses, which would be expected during operation in environments with significant trapped energetic particles such as during a mission to Europa. Our results support future efforts to use in situ sequencing to test theories of panspermia and/or whether life has a common chemical basis. PMID:23734755

  14. Mineral exploration and soil analysis using in situ neutron activation

    USGS Publications Warehouse

    Senftle, F.E.; Hoyte, A.F.

    1966-01-01

    A feasibility study has been made to operate by remote control an unshielded portable positive-ion accelerator type neutron source to induce activities in the ground or rock by "in situ" neutron irradiation. Selective activation techniques make it possible to detect some thirty or more elements by irradiating the ground for periods of a few minutes with either 3-MeV or 14-MeV neutrons. The depth of penetration of neutrons, the effect of water content of the soil on neutron moderation, gamma ray attenuation in the soil and other problems are considered. The analysis shows that, when exploring for most elements of economic interest, the reaction 2H(d,n)3He yielding ??? 3-MeV neutrons is most practical to produce a relatively uniform flux of neutrons of less than 1 keV to a depth of 19???-20???. Irradiation with high energy neutrons (??? 14 MeV) can also be used and may be better suited for certain problems. However, due to higher background and lower sensitivity for the heavy minerals, it is not a recommended neutron source for general exploration use. Preliminary experiments have been made which indicate that neutron activation in situ is feasible for a mineral exploration or qualititative soil analysis. ?? 1976.

  15. Development and evaluation of in situ gel of pregabalin

    PubMed Central

    Madan, Jyotsana R; Adokar, Bhushan R; Dua, Kamal

    2015-01-01

    Aim and Background: Pregabalin (PRG), an analog of gamma-aminobutyric acid, reduces the release of many neurotransmitters, including glutamate, and noradrenaline. It is used for the treatment of epilepsy; simple and complex partial convulsion. The present research work aims to ensure a high drug absorption by retarding the advancement of PRG formulation through the gastrointestinal tract. The work aims to design a controlled release PRG formulation which is administered as liquid and further gels in the stomach and floats in gastric juice. Materials and Methods: In situ gelling formulations were prepared using sodium alginate, calcium chloride, sodium citrate, hydroxypropyl methylcellulose (HPMC) K100M, and sodium bicarbonate. The prepared formulations were evaluated for solution viscosity, drug content, in vitro gelling studies, gel strength, and in vitro drug release. The final formulation was optimized using a 32 full factorial design. Results: The formulation containing 2.5% w/v sodium alginate and 0.2% w/v calcium chloride were considered optimum since it showed minimum floating lag time (18 s), optimum viscosity (287.3 cps), and gel strength (4087.17 dyne/cm2). The optimized formulation follows Korsmeyer-Peppas kinetic model with n value 0.3767 representing Fickian diffusion mechanism of drug release. Conclusion: Floating in situ gelling system of PRG can be formulated using sodium alginate as a gelling polymer and calcium chloride as a complexing agent to control the drug release for about 12 h for the treatment of epilepsy. PMID:26682193

  16. In-situ bioremediation via horizontal wells

    SciTech Connect

    Hazen, T.C.; Looney, B.B.; Enzien, M.; Franck, M.M.; Fliermans, C.B.; Eddy, C.A.

    1993-12-31

    This project is designed to demonstrate in situ bioremediation of groundwater and sediment contaminated with chlorinated solvents. Indigenous microorganisms were stimulated to degrade TCE, PCE and their daughter products in situ by addition of nutrients to the contaminated zone. In situ biodegradation is a highly attractive technology for remediation because contaminants are destroyed, not simply moved to another location or immobilized, thus decreasing costs, risks, and time, while increasing efficiency and public and regulatory acceptability. Bioremediation has been found to be among the least costly technologies in applications where it will work (Radian 1989). Subsurface soils and water adjacent to an abandoned process sewer line at the SRS have been found to have elevated levels of TCE (Marine and Bledsoe 1984). This area of subsurface and groundwater contamination is the focus of a current integrated demonstration of new remediation technologies utilizing horizontal wells. Bioremediation has the potential to enhance the performance of in situ air stripping as well as offering stand-alone remediation of this and other contaminated sites (Looney et al. 1991). Horizontal wells could also be used to enhance the recovery of groundwater contaminants for bioreactor conversions from deep or inaccessible areas (e.g., under buildings) and to enhance the distribution of nutrient or microbe additions in an in situ bioremediation.

  17. In situ forming polymeric drug delivery systems.

    PubMed

    Madan, M; Bajaj, A; Lewis, S; Udupa, N; Baig, J A

    2009-05-01

    In situ forming polymeric formulations are drug delivery systems that are in sol form before administration in the body, but once administered, undergo gelation in situ, to form a gel. The formation of gels depends on factors like temperature modulation, pH change, presence of ions and ultra violet irradiation, from which the drug gets released in a sustained and controlled manner. Various polymers that are used for the formulation of in situ gels include gellan gum, alginic acid, xyloglucan, pectin, chitosan, poly(DL-lactic acid), poly(DL-lactide-co-glycolide) and poly-caprolactone. The choice of solvents like water, dimethylsulphoxide, N-methyl pyrrolidone, triacetin and 2-pyrrolidone for these formulations depends on the solubility of polymer used. Mainly in situ gels are administered by oral, ocular, rectal, vaginal, injectable and intraperitoneal routes. The in situ gel forming polymeric formulations offer several advantages like sustained and prolonged action in comparison to conventional drug delivery systems. The article presents a detailed review of these types of polymeric systems, their evaluation, advancements and their commercial formulations. From a manufacturing point of view, the production of such devices is less complex and thus lowers the investment and manufacturing cost. PMID:20490289

  18. In Situ Forming Polymeric Drug Delivery Systems

    PubMed Central

    Madan, M.; Bajaj, A.; Lewis, S.; Udupa, N.; Baig, J. A.

    2009-01-01

    In situ forming polymeric formulations are drug delivery systems that are in sol form before administration in the body, but once administered, undergo gelation in situ, to form a gel. The formation of gels depends on factors like temperature modulation, pH change, presence of ions and ultra violet irradiation, from which the drug gets released in a sustained and controlled manner. Various polymers that are used for the formulation of in situ gels include gellan gum, alginic acid, xyloglucan, pectin, chitosan, poly(DL-lactic acid), poly(DL-lactide-co-glycolide) and poly-caprolactone. The choice of solvents like water, dimethylsulphoxide, N-methyl pyrrolidone, triacetin and 2-pyrrolidone for these formulations depends on the solubility of polymer used. Mainly in situ gels are administered by oral, ocular, rectal, vaginal, injectable and intraperitoneal routes. The in situ gel forming polymeric formulations offer several advantages like sustained and prolonged action in comparison to conventional drug delivery systems. The article presents a detailed review of these types of polymeric systems, their evaluation, advancements and their commercial formulations. From a manufacturing point of view, the production of such devices is less complex and thus lowers the investment and manufacturing cost. PMID:20490289

  19. An alternative in situ gel-formulation of levofloxacin eye drops for prolong ocular retention

    PubMed Central

    Gupta, Himanshu; Aqil, M.; Khar, R. K.; Ali, Asgar; Bhatnagar, Aseem; Mittal, Gaurav

    2015-01-01

    Introduction: Delivering drugs to ocular region is a challenging task. Eye physiological barriers lead to relatively less therapeutic and bioavailability effect by the conventional eye drops. This may be overcome by the use of in situ gel delivery system. Objective: The objective of our work was to formulate an ocular delivery system of levofloxacin, based on the concept of ion (sodium alginate) and pH (chitosan) activated in situ gelation concept. Due to its elastic properties, in situ gels resist the ocular drainage of drug leading to longer contact times with ocular surface. Materials and Methods: The formulation was evaluated for physicochemical characteristics, in vitro drug release. Ocular retention studies were carried out by Gamma scintigraphy. Time activity curve was plotted between marketed formulation and developed formulation for comparing drug drainage from the eye with time. Ocular tolerance test was performed by handheld infra-red camera. Results and Discussion: The formulations showed a first-order release pattern over 12 h. Both in vitro release studies and in vivo gamma scintigraphy precorneal retention studies indicated better therapeutic efficacy compared with standard eye drops. Conclusion: The results demonstrated that the developed in situ gel of levofloxacin is nonirritant, has prolonged action and is a better option in terms of retention, ocular bioavailability and patient compliance when compared with plain eye drops formulation. PMID:25709330

  20. Terrestrial gamma radiation baseline mapping using ultra low density sampling methods.

    PubMed

    Kleinschmidt, R; Watson, D

    2016-01-01

    Baseline terrestrial gamma radiation maps are indispensable for providing basic reference information that may be used in assessing the impact of a radiation related incident, performing epidemiological studies, remediating land contaminated with radioactive materials, assessment of land use applications and resource prospectivity. For a large land mass, such as Queensland, Australia (over 1.7 million km(2)), it is prohibitively expensive and practically difficult to undertake detailed in-situ radiometric surveys of this scale. It is proposed that an existing, ultra-low density sampling program already undertaken for the purpose of a nationwide soil survey project be utilised to develop a baseline terrestrial gamma radiation map. Geoelement data derived from the National Geochemistry Survey of Australia (NGSA) was used to construct a baseline terrestrial gamma air kerma rate map, delineated by major drainage catchments, for Queensland. Three drainage catchments (sampled at the catchment outlet) spanning low, medium and high radioelement concentrations were selected for validation of the methodology using radiometric techniques including in-situ measurements and soil sampling for high resolution gamma spectrometry, and comparative non-radiometric analysis. A Queensland mean terrestrial air kerma rate, as calculated from the NGSA outlet sediment uranium, thorium and potassium concentrations, of 4969nGyh(-1) (n=311, 3? 99% confidence level) is proposed as being suitable for use as a generic terrestrial air kerma rate background range. Validation results indicate that catchment outlet measurements are representative of the range of results obtained across the catchment and that the NGSA geoelement data is suitable for calculation and mapping of terrestrial air kerma rate. PMID:26063584

  1. Assessment of ambient gamma dose rate around a prospective uranium mining area of South India - A comparative study of dose by direct methods and soil radioactivity measurements

    NASA Astrophysics Data System (ADS)

    Karunakara, N.; Yashodhara, I.; Sudeep Kumara, K.; Tripathi, R. M.; Menon, S. N.; Kadam, S.; Chougaonkar, M. P.

    Indoor and outdoor gamma dose rates were evaluated around a prospective uranium mining region - Gogi, South India through (i) direct measurements using a GM based gamma dose survey meter, (ii) integrated measurement days using CaSO4:Dy based thermo luminescent dosimeters (TLDs), and (iii) analyses of 273 soil samples for 226Ra, 232Th, and 40K activity concentration using HPGe gamma spectrometry. The geometric mean values of indoor and outdoor gamma dose rates were 104 nGy h-1 and 97 nGy h-1, respectively with an indoor to outdoor dose ratio of 1.09. The gamma dose rates and activity concentrations of 226Ra, 232Th, and 40K varied significantly within a small area due to the highly localized mineralization of the elements. Correlation study showed that the dose estimated from the soil radioactivity is better correlated with that measured directly using the portable survey meter, when compared to that obtained from TLDs. This study showed that in a region having localized mineralization in situ measurements using dose survey meter provide better representative values of gamma dose rates.

  2. In Situ Imaging of Atomic Quantum Gases

    NASA Astrophysics Data System (ADS)

    Hung, Chen-Lung; Chin, Cheng

    2015-09-01

    One exciting progress in recent cold atom experiments is the development of high resolution, in situ imaging techniques for atomic quantum gases.1-3 These new powerful tools provide detailed information on the distribution of atoms in a trap with resolution approaching the level of single atom and even single lattice site, and complement the welldeveloped time-of-flight method that probes the system in momentum space. In a condensed matter analogy, this technique is equivalent to locating electrons of a material in a snap shot. In situ imaging has offered a new powerful tool to study atomic gases and inspired many new research directions and ideas. In this chapter, we will describe the experimental setup of in situ absorption imaging, observables that can be extracted from the images, and new physics that can be explored with this technique.

  3. In situ macromolecular crystallography using microbeams

    PubMed Central

    Axford, Danny; Owen, Robin L.; Aishima, Jun; Foadi, James; Morgan, Ann W.; Robinson, James I.; Nettleship, Joanne E.; Owens, Raymond J.; Moraes, Isabel; Fry, Elizabeth E.; Grimes, Jonathan M.; Harlos, Karl; Kotecha, Abhay; Ren, Jingshan; Sutton, Geoff; Walter, Thomas S.; Stuart, David I.; Evans, Gwyndaf

    2012-01-01

    Despite significant progress in high-throughput methods in macromolecular crystallography, the production of diffraction-quality crystals remains a major bottleneck. By recording diffraction in situ from crystals in their crystallization plates at room temperature, a number of problems associated with crystal handling and cryoprotection can be side-stepped. Using a dedicated goniometer installed on the microfocus macromolecular crystallography beamline I24 at Diamond Light Source, crystals have been studied in situ with an intense and flexible microfocus beam, allowing weakly diffracting samples to be assessed without a manual crystal-handling step but with good signal to noise, despite the background scatter from the plate. A number of case studies are reported: the structure solution of bovine enterovirus 2, crystallization screening of membrane proteins and complexes, and structure solution from crystallization hits produced via a high-throughput pipeline. These demonstrate the potential for in situ data collection and structure solution with microbeams. PMID:22525757

  4. In situ macromolecular crystallography using microbeams.

    PubMed

    Axford, Danny; Owen, Robin L; Aishima, Jun; Foadi, James; Morgan, Ann W; Robinson, James I; Nettleship, Joanne E; Owens, Raymond J; Moraes, Isabel; Fry, Elizabeth E; Grimes, Jonathan M; Harlos, Karl; Kotecha, Abhay; Ren, Jingshan; Sutton, Geoff; Walter, Thomas S; Stuart, David I; Evans, Gwyndaf

    2012-05-01

    Despite significant progress in high-throughput methods in macromolecular crystallography, the production of diffraction-quality crystals remains a major bottleneck. By recording diffraction in situ from crystals in their crystallization plates at room temperature, a number of problems associated with crystal handling and cryoprotection can be side-stepped. Using a dedicated goniometer installed on the microfocus macromolecular crystallography beamline I24 at Diamond Light Source, crystals have been studied in situ with an intense and flexible microfocus beam, allowing weakly diffracting samples to be assessed without a manual crystal-handling step but with good signal to noise, despite the background scatter from the plate. A number of case studies are reported: the structure solution of bovine enterovirus 2, crystallization screening of membrane proteins and complexes, and structure solution from crystallization hits produced via a high-throughput pipeline. These demonstrate the potential for in situ data collection and structure solution with microbeams. PMID:22525757

  5. Scientific rationale for Saturn's in situ exploration

    NASA Astrophysics Data System (ADS)

    Mousis, O.; Fletcher, L. N.; Lebreton, J.-P.; Wurz, P.; Cavali, T.; Coustenis, A.; Courtin, R.; Gautier, D.; Helled, R.; Irwin, P. G. J.; Morse, A. D.; Nettelmann, N.; Marty, B.; Rousselot, P.; Venot, O.; Atkinson, D. H.; Waite, J. H.; Reh, K. R.; Simon, A. A.; Atreya, S.; Andr, N.; Blanc, M.; Daglis, I. A.; Fischer, G.; Geppert, W. D.; Guillot, T.; Hedman, M. M.; Hueso, R.; Lellouch, E.; Lunine, J. I.; Murray, C. D.; O`Donoghue, J.; Rengel, M.; Snchez-Lavega, A.; Schmider, F.-X.; Spiga, A.; Spilker, T.; Petit, J.-M.; Tiscareno, M. S.; Ali-Dib, M.; Altwegg, K.; Bolton, S. J.; Bouquet, A.; Briois, C.; Fouchet, T.; Guerlet, S.; Kostiuk, T.; Lebleu, D.; Moreno, R.; Orton, G. S.; Poncy, J.

    2014-12-01

    Remote sensing observations meet some limitations when used to study the bulk atmospheric composition of the giant planets of our solar system. A remarkable example of the superiority of in situ probe measurements is illustrated by the exploration of Jupiter, where key measurements such as the determination of the noble gases' abundances and the precise measurement of the helium mixing ratio have only been made available through in situ measurements by the Galileo probe. This paper describes the main scientific goals to be addressed by the future in situ exploration of Saturn placing the Galileo probe exploration of Jupiter in a broader context and before the future probe exploration of the more remote ice giants. In situ exploration of Saturn's atmosphere addresses two broad themes that are discussed throughout this paper: first, the formation history of our solar system and second, the processes at play in planetary atmospheres. In this context, we detail the reasons why measurements of Saturn's bulk elemental and isotopic composition would place important constraints on the volatile reservoirs in the protosolar nebula. We also show that the in situ measurement of CO (or any other disequilibrium species that is depleted by reaction with water) in Saturn's upper troposphere may help constraining its bulk O/H ratio. We compare predictions of Jupiter and Saturn's bulk compositions from different formation scenarios, and highlight the key measurements required to distinguish competing theories to shed light on giant planet formation as a common process in planetary systems with potential applications to most extrasolar systems. In situ measurements of Saturn's stratospheric and tropospheric dynamics, chemistry and cloud-forming processes will provide access to phenomena unreachable to remote sensing studies. Different mission architectures are envisaged, which would benefit from strong international collaborations, all based on an entry probe that would descend through Saturn's stratosphere and troposphere under parachute down to a minimum of 10 bar of atmospheric pressure. We finally discuss the science payload required on a Saturn probe to match the measurement requirements.

  6. In-situ vitrification of waste materials

    DOEpatents

    Powell, James R. (Shoreham, NY); Reich, Morris (Kew Gardens Hills, NY); Barletta, Robert (Wading River, NY)

    1997-11-14

    A method for the in-situ vitrification of waste materials in a disposable can that includes an inner container and an outer container is disclosed. The method includes the steps of adding frit and waste materials to the inner container, removing any excess water, heating the inner container such that the frit and waste materials melt and vitrify after cooling, while maintaining the outer container at a significantly lower temperature than the inner container. The disposable can is then cooled to ambient temperatures and stored. A device for the in-situ vitrification of waste material in a disposable can is also disclosed.

  7. In-situ vitrification of waste materials

    DOEpatents

    Powell, J.R.; Reich, M.; Barletta, R.

    1997-10-14

    A method for the in-situ vitrification of waste materials in a disposable can that includes an inner container and an outer container is disclosed. The method includes the steps of adding frit and waste materials to the inner container, removing any excess water, heating the inner container such that the frit and waste materials melt and vitrify after cooling, while maintaining the outer container at a significantly lower temperature than the inner container. The disposable can is then cooled to ambient temperatures and stored. A device for the in-situ vitrification of waste material in a disposable can is also disclosed. 7 figs.

  8. In situ ply strengths - An initial assessment

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.; Sullivan, T. L.

    1978-01-01

    The in situ ply strengths in several composites were calculated using a computational procedure developed for this purpose. Laminate fracture data for appropriate low modulus and high modulus fiber composites were used in the laminate analysis in conjunction with the method of least squares. The laminate fracture data were obtained from tests on Modmor-I graphite/epoxy, AS-graphite/epoxy, boron/epoxy and E-glass/epoxy. The results obtained show that the calculated in situ ply strengths can be considerably different from those measured in unidirectional composites, especially the transverse strengths and those in angleplied laminates with transply cracks.

  9. Raman Spectrometry.

    ERIC Educational Resources Information Center

    Gardiner, Derek J.

    1980-01-01

    Reviews mainly quantitative analytical applications in the field of Raman spectrometry. Includes references to other reviews, new and analytically untested techniques, and novel sampling and instrument designs. Cites 184 references. (CS)

  10. IN SITU SOIL VAPOR EXTRACTION TREATMENT

    EPA Science Inventory

    Soil vapor extraction (SVE) is designed to physically remove volatile compounds, generally from the vadose or unsaturated zone. t is an in situ process employing vapor extraction wells alone or in combination with air injection wells. acuum blowers supply the motive force, induci...

  11. Controlled in situ etch-back

    NASA Technical Reports Server (NTRS)

    Mattauch, R. J.; Seabaugh, A. C. (inventors)

    1981-01-01

    A controlled in situ etch-back technique is disclosed in which an etch melt and a growth melt are first saturated by a source-seed crystal and thereafter etch-back of a substrate takes place by the slightly undersaturated etch melt, followed by LPE growth of a layer by the growth melt, which is slightly supersaturated.

  12. Transesterification in situ of sunflower seed oil

    SciTech Connect

    Harrington, K.J.; D'Arch-Evans, C.

    1985-06-01

    Transesterification of sunflower seed oil in situ has produced methyl and ethyl esters in yields greater than 40% of the dry seed weight. This figure compares with a typical yield of ca. 30% when the esters were prepared in the conventional manner from preextracted seed oil. 14 references.

  13. FIELD STUDIES OF IN SITU SOIL WASHING

    EPA Science Inventory

    The EPA and US Air Force conducted a research test program to demonstrate the removal of hydrocarbons and chlorinated hydrocarbons from a sandy soil by in situ soil washing using surfactants. Contaminated soil from the fire training area of Volk Air National Guard Base, WI, was f...

  14. Accelerated in situ bioremediation of groundwater

    SciTech Connect

    Truex, M.J.; Hooker, B.S.; Anderson, D.B.

    1996-07-01

    In situ bioremediation, as applied in this project, is based on the principal of biostimulation: supplying nutrients to indigenous microbes to stimulate their metabolic activity and subsequent degradation of contaminants. Typically, a network of injection and extraction wells are used to recirculate groundwater into which amendments are added and distributed within the aquifer. The objective of the in situ process is to create in the aquifer a microbially active zone that maximizes contaminant destruction while controlling the distribution of microbial growth. It is important to control microbial growth to avoid plugging the aquifer near the injection well and to establish and sustain maximum treatment zones for each injection well. Figure I illustrates this concept for in situ bioremediation. The technology described herein is innovative in its use of the computer-based Accelerated Bioremediation Design Tool (ABDT) to aid in selecting appropriate system designs and to determine optimal operating strategies. In addition, numerical simulations within the design tool proved to be valuable during remediation operations to determine appropriate changes in the` operating strategy as the bioremediation process progressed. This is particularly important because in situ bioremediation is not a steady- state process, and corrective actions to operating parameters are typically needed to maintain both rapid destruction rates and hydraulic containment.

  15. ENGINEERING BULLETIN: IN SITU BIODEGRADATION TREATMENT

    EPA Science Inventory

    In situ biodegradation may be used to treat low-to-intermediate concentrations of organic contaminants in place without disturbing or displacing the contaminated media. lthough this technology hag been used to degrade a limited number of inorganics, specifically cyanide and nitra...

  16. DEMONSTRATION BULLETIN: IN SITU VITRIFICATION - GEOSAFE CORPORATION

    EPA Science Inventory

    in Situ Vitrification (ISV) is designed to treat soils, sludges, sediments, and mine tailings contaminated with organic and inorganic compounds. The process uses electrical current to heat (mett) and vitrify the soil in place. Organic contaminants are decomposed by the extreme h...

  17. IN SITU MONITORING OF ENVIRONMENTAL GENOTOXINS

    EPA Science Inventory

    Potential health hazard of a test site can be assessed by (1) epidemiological survey of the indigenous populations, (2) in situ monitoring by introducing test organisms into the environment, and (3) bringing environmental samples from the test site into the laboratory and perform...

  18. TECHNICAL REFERENCE DOCUMENT: IN SITU THERMAL TREATMENT

    EPA Science Inventory

    This report will describe the state of practice and current capabilities of in-situ thermal treatment technologies. PLEASE NOTE: If peer review is needed, it will be conducted by the Army Corps of Engineers who is our partner in developing this report.

  19. ENGINEERING BULLETIN: IN SITU VITRIFICATION TREATMENT

    EPA Science Inventory

    In situ vitrification (ISV) uses electrical power to heat and melt soil, sludge, mine tailings, buried wastes, and sediments contaminated with organic, inorganic, and metal-bearing hazardous wastes. The molten material cools to form a hard, monolithic, chemically inert, stable...

  20. In-Situ Burning of Spilled Oil.

    ERIC Educational Resources Information Center

    Allen, Alan A.

    1991-01-01

    Reviews in-situ burning with particular emphasis on how it can be applied in water-related oil spill situations. Presents and discusses the use of nomograms and development of techniques cited for safe and effective ignition and controlled burning of spilled oil. Includes representative oil spill scenarios and possible responses. (15 references)

  1. ENGINEERING BULLETIN: IN SITU BIODEGRADATION TREATMENT

    EPA Science Inventory

    In situ biodegradation may be used to treat low-to-intermediate concentrations of organic contaminants in place without disturbing or displacing the contaminated media. Although this technology has been used to degrade a limited number of inorganics, specifically cyanide and nitr...

  2. IN SITU LEAD IMMOBILIZATION BY APATITE

    EPA Science Inventory

    Lead contamination is of environmental concern due to its effect on human health. he purpose of this study was to develop a technology to immobilize Pb in situ in contaminated soils and wastes using apatite. ydroxyapatite [Ca10(PO4)6(OH)2]was reacted with aqueous Pb, resinexchang...

  3. Refueling with In-Situ Produced Propellants

    NASA Technical Reports Server (NTRS)

    Chato, David J.

    2014-01-01

    In-situ produced propellants have been identified in many architecture studies as key to implementing feasible chemical propulsion missions to destinations beyond lunar orbit. Some of the more noteworthy ones include: launching from Mars to return to Earth (either direct from the surface, or via an orbital rendezvous); using the Earth-Moon Lagrange point as a place to refuel Mars transfer stages with Lunar surface produced propellants; and using Mars Moon Phobos as a place to produce propellants for descent and ascent stages bound for the Mars surface. However successful implementation of these strategies require an ability to successfully transfer propellants from the in-situ production equipment into the propellant tankage of the rocket stage used to move to the desired location. In many circumstances the most desirable location for this transfer to occur is in the low-gravity environment of space. In support of low earth orbit propellant depot concepts, extensive studies have been conducted on transferring propellants in-space. Most of these propellant transfer techniques will be applicable to low gravity operations in other locations. Even ground-based transfer operations on the Moon, Mars, and especially Phobos could benefit from the propellant conserving techniques used for depot refueling. This paper will review the literature of in-situ propellants and refueling to: assess the performance benefits of the use in-situ propellants for mission concepts; review the parallels with propellant depot efforts; assess the progress of the techniques required; and provide recommendations for future research.

  4. In-Situ Burning of Spilled Oil.

    ERIC Educational Resources Information Center

    Allen, Alan A.

    1991-01-01

    Reviews in-situ burning with particular emphasis on how it can be applied in water-related oil spill situations. Presents and discusses the use of nomograms and development of techniques cited for safe and effective ignition and controlled burning of spilled oil. Includes representative oil spill scenarios and possible responses. (15 references)…

  5. Fabrication Capabilities Utilizing In Situ Materials

    NASA Technical Reports Server (NTRS)

    McLemore, Carole A.; Fikes, John C.; Darby, Charles A.; Good, James E.; Gilley, Scott D.

    2008-01-01

    The National Aeronautics and Space Administration (NASA) has a Space Exploration Policy that lays out a plan that far exceeds the earlier Apollo goals where landing on the moon and taking those first historic steps fulfilled the mission. The policy states that we will set roots on the moon by establishing an outpost. This outpost will be used as a test bed for residing in more distant locales, such as Mars. In order to become self-sufficient, the occupants must have the capability to fabricate component parts in situ. Additionally, in situ materials must be used to minimize valuable mission upmass and to be as efficient as possible. In situ materials can be found from various sources such as raw lunar regolith whereby specific constituents can be extracted from the regolith (such as aluminum, titanium, or iron), and existing hardware already residing on the moon from past Apollo missions. The Electron Beam Melting (EBM) process lends itself well to fabricating parts, tools, and other necessary items using in situ materials and will be discussed further in this paper.

  6. IN SITU LEAD IMMOBILIZATION BY APATITE

    EPA Science Inventory

    Lead contamination is of environmental concern due to its effect on human health. The purpose of this study was to develop a technology to immobilize Pb in situ in contaminated soils and wastes using apatite. Hydroxyapatite [Ca10(PO4)6(O...

  7. "In Situ" Generation of Compressed Inverted Files.

    ERIC Educational Resources Information Center

    Moffat, Alistair; Bell, Timothy A. H.

    1995-01-01

    Discussion of index construction for large text collections highlights a new indexing algorithm designed to create large compressed inverted indexes "in situ." Topics include a computational model, inversion, index compression, merging, experimental test results, effect on retrieval performance, memory restrictions, and dynamic collections.

  8. ENGINEERING BULLETIN: IN SITU SOIL FLUSHING

    EPA Science Inventory

    In situ soil flushing is the extraction of contaminants from the soil with water or other suitable aqueous solutions. Soil flushing is accomplished by passing the extraction fluid through in-place soils using an injection or infiltration process. Extraction fluids must be recover...

  9. Imaging Mass Spectrometry in Neuroscience

    PubMed Central

    2013-01-01

    Imaging mass spectrometry is an emerging technique of great potential for investigating the chemical architecture in biological matrices. Although the potential for studying neurobiological systems is evident, the relevance of the technique for application in neuroscience is still in its infancy. In the present Review, a principal overview of the different approaches, including matrix assisted laser desorption ionization and secondary ion mass spectrometry, is provided with particular focus on their strengths and limitations for studying different neurochemical species in situ and in vitro. The potential of the various approaches is discussed based on both fundamental and biomedical neuroscience research. This Review aims to serve as a general guide to familiarize the neuroscience community and other biomedical researchers with the technique, highlighting its great potential and suitability for comprehensive and specific chemical imaging. PMID:23530951

  10. In Situ Cleanable Alternative HEPA Filter Media

    SciTech Connect

    Adamson, D. J.; Terry, M. T.

    2002-02-28

    The Westinghouse Savannah River Company, located at the Savannah River Site in Aiken, South Carolina, is currently testing two types of filter media for possible deployment as in situ regenerable/cleanable High Efficiency Particulate Air (HEPA) filters. The filters are being investigated to replace conventional, disposable, glass-fiber, HEPA filters that require frequent removal, replacement, and disposal. This is not only costly and subjects site personnel to radiation exposure, but adds to the ever-growing waste disposal problem. The types of filter media being tested, as part of a National Energy Technology Laboratory procurement, are sintered nickel metal and ceramic monolith membrane. These media were subjected to a hostile environment to simulate conditions that challenge the high-level waste tank ventilation systems. The environment promoted rapid filter plugging to maximize the number of filter loading/cleaning cycles that would occur in a specified period of time. The filters were challenged using nonradioactive simulated high-level waste materials and atmospheric dust; materials that cause filter pluggage in the field. The filters are cleaned in situ using an aqueous solution. The study found that both filter media were insensitive to high humidity or moisture conditions and were easily cleaned in situ. The filters regenerated to approximately clean filter status even after numerous plugging and in situ cleaning cycles. Air Techniques International is conducting particle retention testing on the filter media at the Oak Ridge Filter Test Facility. The filters are challenged using 0.3-mm di-octyl phthalate particles. Both the ceramic and sintered media have a particle retention efficiency > 99.97%. The sintered metal and ceramic filters not only can be cleaned in situ, but also hold great potential as a long life alternative to conventional HEPA filters. The Defense Nuclear Facility Safety Board Technical Report, ''HEPA Filters Used in the Department of Energy's Hazardous Facilities'', found that conventional glass fiber HEPA filters are structurally weak and easily damaged by water or fire. The structurally stronger sintered metal and ceramic filters would reduce the potential of a catastrophic HEPA filter failure due to filter media breakthrough in the process ventilation system. An in situ regenerable system may also find application in recovering nuclear materials, such as plutonium, collected on glove box exhaust HEPA filters. This innovative approach of the in situ regenerative filtration system may be a significant improvement upon the shortfalls of conventional disposable HEPA filters.

  11. In-Situ Characterization of Underwater Radioactive Sludge

    SciTech Connect

    Simpson, A.P.; Clapham, M.J.; Swinson, B.

    2008-07-01

    A fundamental requirement underpinning safe clean-up technologies for legacy spent nuclear fuel (SNF) ponds, pools and wet silos is the ability to characterize the radioactive waste form prior to retrieval. The corrosion products resulting from the long term underwater storage of spent nuclear fuel, reactor components and reprocessing debris present a major hazard to facility decontamination and decommissioning in terms of their radioactive content and physical / chemical reactivity. The ability to perform in-situ underwater non-destructive characterization of sludge and debris in a safe and cost-effective manner offers significant benefits over traditional destructive sampling methods. Several techniques are available for underwater measurements including (i) Gross gamma counting, (ii) Low-, Medium- and High- Resolution Gamma Spectroscopy, (iii) Passive neutron counting and (iv) Active Neutron Interrogation. The optimum technique depends on (i) the radioactive inventory (ii) mechanical access restrictions for deployment of the detection equipment, interrogation sources etc. (iii) the integrity of plant records and (iv) the extent to which Acceptable Knowledge which may be used for 'fingerprinting' the radioactive contents to a marker nuclide. Prior deployments of underwater SNF characterization equipment around the world have been reviewed with respect to recent developments in gamma and neutron detection technologies, digital electronics advancements, data transfer techniques, remote operation capabilities and improved field ruggedization. Modeling and experimental work has been performed to determine the capabilities, performance envelope and operational limitations of the future generation of non-destructive underwater sludge characterization techniques. Recommendations are given on the optimal design of systems and procedures to provide an acceptable level of confidence in the characterization of residual sludge content of legacy wet storage facilities such that retrieval and repackaging of SNF sludges may proceed safely and efficiently with support of the regulators and the public. (author)

  12. In Situ Remediation Integrated Program: Technology summary

    SciTech Connect

    Not Available

    1994-02-01

    The In Situ Remediation Integrated Program (ISR IP) was instituted out of recognition that in situ remediation could fulfill three important criteria: significant cost reduction of cleanup by eliminating or minimizing excavation, transportation, and disposal of wastes; reduced health impacts on workers and the public by minimizing exposure to wastes during excavation and processing; and remediation of inaccessible sites, including: deep subsurfaces, in, under, and around buildings. Buried waste, contaminated soils and groundwater, and containerized wastes are all candidates for in situ remediation. Contaminants include radioactive wastes, volatile and non-volatile organics, heavy metals, nitrates, and explosive materials. The ISR IP intends to facilitate development of in situ remediation technologies for hazardous, radioactive, and mixed wastes in soils, groundwater, and storage tanks. Near-term focus is on containment of the wastes, with treatment receiving greater effort in future years. ISR IP is an applied research and development program broadly addressing known DOE environmental restoration needs. Analysis of a sample of 334 representative sites by the Office of Environmental Restoration has shown how many sites are amenable to in situ remediation: containment--243 sites; manipulation--244 sites; bioremediation--154 sites; and physical/chemical methods--236 sites. This needs assessment is focused on near-term restoration problems (FY93--FY99). Many other remediations will be required in the next century. The major focus of the ISR EP is on the long term development of permanent solutions to these problems. Current needs for interim actions to protect human health and the environment are also being addressed.

  13. Gamma-ray spectrometer experiment

    NASA Technical Reports Server (NTRS)

    Arnold, J. R.; Peterson, L. E.; Metzger, A. E.; Trombka, J. I.

    1972-01-01

    The experiments in gamma-ray spectrometry to determine the geochemical composition of the lunar surface are reported. The theory is discussed of discrete energy lines of natural radioactivity, and the lines resulting from the bombardment of the lunar surface by high energy cosmic rays. The gamma-ray spectrometer used in lunar orbit and during transearth coast is described, and a preliminary analysis of the results is presented.

  14. Mass Spectrometry in the Home and Garden

    NASA Astrophysics Data System (ADS)

    Pulliam, Christopher J.; Bain, Ryan M.; Wiley, Joshua S.; Ouyang, Zheng; Cooks, R. Graham

    2015-02-01

    Identification of active components in a variety of chemical products used directly by consumers is described at both trace and bulk levels using mass spectrometry. The combination of external ambient ionization with a portable mass spectrometer capable of tandem mass spectrometry provides high chemical specificity and sensitivity as well as allowing on-site monitoring. These experiments were done using a custom-built portable ion trap mass spectrometer in combination with the ambient ionization methods of paper spray, leaf spray, and low temperature plasma ionization. Bactericides, garden chemicals, air fresheners, and other products were examined. Herbicide applied to suburban lawns was detected in situ on single leaves 5 d after application.

  15. Development of an in situ derivatization technique for rapid analysis of levoglucosan and polar compounds in atmospheric organic aerosol

    NASA Astrophysics Data System (ADS)

    Sheesley, Rebecca J.; Mieritz, Mark; DeMinter, Jeff T.; Shelton, Brandon R.; Schauer, James J.

    2015-12-01

    A novel thermal desorption gas chromatography mass spectrometry (TD-GCMS) technique was developed for the analysis of levoglucosan and other polar compounds in atmospheric organic aerosol. The method employs an in situ derivatization to add tri-methylsilyl groups to alcohol functional groups on simple carbohydrates, like levoglucosan and sterols. The new method was then demonstrated on a set of 40 filter samples collected in Fresno, CA. The results from the in situ silylation TD-GCMS method were compared, using levoglucosan, with a solvent extraction, high-volume injection GCMS method resulting in an r2 = 0.91.

  16. The Orléans-Lithothèque - an analogue rockstore for in situ missions

    NASA Astrophysics Data System (ADS)

    Bost, Nicolas; Westall, Frances; Ramboz, Claire

    2010-05-01

    The Orléans-Lithothèque - an analogue rockstore for in situ missions Nicolas Bost, Frances Westall, Claire Ramboz, Axelle Hubert, Derek Pullan, Beda Hofmann, Elisabeth Vergès, Michel Viso, Jorge Vago, Christelle Briois, Bruno Scaillet, Michel Tagger Instruments for in-situ missions to extraterrestrial bodies should ideally be cross calibrated using a common suite of relevant materials. Such multi-instrument calibration would enable a better comparison of instrument performances during the mission, as well as aid in the interpretation of the in-situ measurements. At the CNRS in Orléans, the Observatoire des Sciences de l'Univers de la region Centre is creating a collection of well-characterised rocks that will be available for testing and calibrating instruments to be flown on space missions. The characteristics of the collection's analogue materials will be described in an online database. In view of the upcoming 2018 ExoMars rover mission, we are concentrating initially on materials of direct relevance to Mars. The initial collection includes basalts (ultramafic, weathered, andesitic, hydrothermally-silicified); sediments (volcanic, biolaminated, banded iron formation); and minerals (silica, evaporites, clays, Fe oxides). This set of samples will be augmented with time. All samples will be characterised petrographically, petrologically, and geochemically using the types of analyses likely to be performed during an in-situ mission: hand specimen description, optical microscopy, mineralogical analysis (XRD, Raman and IR spectrometry), elemental analysis (EDX, microprobe, ICP) and organics analysis (Raman, pyr-GCMS).

  17. In situ nanoparticle sizing with zeptomole sensitivity.

    PubMed

    Batchelor-McAuley, Christopher; Ellison, Joanna; Tschulik, Kristina; Hurst, Philip L; Boldt, Regine; Compton, Richard G

    2015-08-01

    We present the basis for an entirely new approach to in situ nanoparticle sizing. Nanoparticles containing just 12 zeptomoles (1 zeptomole = 10(-21) moles) of silver, are detected via in situ particle coulometry. These stochastic charge measurements correspond to the transfer of only 7000-8000 electrons, yielding direct information relating to the individual nanoparticle volumes. The resulting particle size distribution (average equivalent radius 5 nm) obtained via nanoparticle coulometry is in excellent correspondence with that attained from TEM analysis. Moreover, the measurable particle size limit by this electrochemical method is shown to be significantly below that of more common optical nanoparticle tracking techniques, and as such can be viewed as a potential disruptive nano-technology. PMID:26050623

  18. In situ bioremediation of Hanford groundwater

    SciTech Connect

    Skeen, R.S.; Roberson, K.R.; Workman, D.J. ); Petersen, J.N.; Shouche, M. . Dept. of Chemical Engineering)

    1992-04-01

    Liquid wastes containing radioactive, hazardous, and regulated chemicals have been generated throughout the 40+ years of operations at the US Department of Energy's (DOE) Hanford Site. Some of these wastes were discharged to the soil column and many of the waste components, including nitrate, carbon tetrachloride (CCl{sub 4}), and several radionuclides, have been detected in the Hanford groundwater. Current DOE policy prohibits the disposal of contaminated liquids directly to the environment, and remediation of existing contaminated groundwaters may be required. In situ bioremediation is one technology currently being developed at Hanford to meet the need for cost effective technologies to clean groundwater contaminated with CCl{sub 4}, nitrate, and other organic and inorganic contaminants. This paper focuses on the latest results of an on going effort to develop effective in situ remediation strategies through the use of predictive simulations.

  19. In situ, noninvasive characterization of superhydrophobic coatings

    NASA Astrophysics Data System (ADS)

    Tepper, G. C.; Samaha, M. A.; Vahedi Tafreshi, H.; Gad-El-Hak, M.

    2011-11-01

    Light scattering was used to measure the time-dependent loss of air entrapped within a submerged microporous hydrophobic surface subjected to different environmental conditions. The loss of trapped air resulted in a measurable decrease in surface reflectivity and the kinetics of the process was determined in real time and compared to surface properties, such as porosity and morphology. The light-scattering results were compared with measurements of skin-friction drag, static contact angle, and contact-angle hysteresis. The In situ, noninvasive optical technique was shown to correlate well with the more conventional methods for quantifying surface hydrophobicity, such as flow slip and contact angle. In situ characterization of submerged hydrophobic surfaces using light scattering represents a new and useful tool for real-time estimation of hydrophobicity and drag reduction. Financial support from the Defense Advanced Research Projects Agency (DARPA), contract number W91CRB-10-1-0003, is acknowledged.

  20. Inherently safe in situ uranium recovery

    SciTech Connect

    Krumhansl, James L; Brady, Patrick V

    2014-04-29

    An in situ recovery of uranium operation involves circulating reactive fluids through an underground uranium deposit. These fluids contain chemicals that dissolve the uranium ore. Uranium is recovered from the fluids after they are pumped back to the surface. Chemicals used to accomplish this include complexing agents that are organic, readily degradable, and/or have a predictable lifetime in an aquifer. Efficiency is increased through development of organic agents targeted to complexing tetravalent uranium rather than hexavalent uranium. The operation provides for in situ immobilization of some oxy-anion pollutants under oxidizing conditions as well as reducing conditions. The operation also artificially reestablishes reducing conditions on the aquifer after uranium recovery is completed. With the ability to have the impacted aquifer reliably remediated, the uranium recovery operation can be considered inherently safe.

  1. In situ bioremediation of chlorinated solvents.

    PubMed Central

    Semprini, L

    1995-01-01

    Chlorinated solvents and their natural transformation products are the most frequently observed groundwater contaminants in the United States. In situ bioremediation using anaerobic or aerobic co-metabolic processes is a promising means of cleaning up contaminated aquifers. Studies show that under natural conditions trichloroethylene can be anaerobically degraded to dichloroethylene, vinyl chloride, and ethylene. Pilot scale field studies of in situ aerobic co-metabolic transformations have shown that indigenous microbes grown on phenol are more effective at degrading trichloroethylene and cis-1,2-dichloroethylene than microbes grown on methane. Modeling studies support field observations and indicate that the removal of trichloroethylene and cis-dichloroethylene results from the biostimulation of an indigenous microbial population. Field tests and modeling studies indicate that, at high TCE concentration, degradation becomes stoichiometrically limited. PMID:8565895

  2. Laser in situ monitoring of combustion processes.

    PubMed

    Arnold, A; Becker, H; Hemberger, R; Hentschel, W; Ketterle, W; Kollner, M; Meienburg, W; Monkhouse, P; Neckel, H; Schafer, M; Schindler, K P; Sick, V; Suntz, R; Wolfrum, J

    1990-11-20

    Several examples of laser in situ monitoring of combustion processes are presented. Using a frequency modulated (13)CO(2) waveguide laser, in situ concentrations of NH(3) down to 1 ppm were measured at temperatures up to 600 degrees C in waste incinerators and power or chemical plants. Following ignition of CH(3)OH-O(2) mixtures by a TEA CO(2) laser, gas temperature profiles were measured using rapid scanning tunable diode laser spectroscopy of CO molecules. In laminar CH(4)-air counterflow diffusion flames at atmospheric pressure absolute concentrations, temperatures, and collisional lifetimes of OH radicals were determined by 2-D and picosecond LIF and absorption spectroscopy. Two-dimensional LIF and Mie scattering were used to observe fuel injection and combustion in a diesel engine. PMID:20577480

  3. In-Situ Planetary Chemical Analysis

    NASA Technical Reports Server (NTRS)

    Kounaves, S. P.; Buehler, M. G.; Grannan, S. M.; Hecht, M. H.; Kuhlman, K. R.

    2000-01-01

    Both, the search for evidence of life on Mars and the assessment of the Martian environment in respect to its compatibility with human explorers, will require the ability to measure and understand the aqueous chemistry of the Martian regolith. Direct in-situ chemical analysis is the only method by which chemical biosignatures can be reliably recognized and the toxicity of the regolith accurately assessed. Qualitative and quantitative determination of the aqueous ionic constituents and their concentrations is critical in developing kinetic and thermodynamic models that can be used to accurately predict the potential of the past or present Martian geochemical environment to have either generated or still sustain life. In-situ chemical characterization could provide evidence as to whether the chemical composition of the regolith or evaporates in suspected ancient water bodies have been biologically influenced.

  4. In situ synthesis of protein arrays.

    PubMed

    He, Mingyue; Stoevesandt, Oda; Taussig, Michael J

    2008-02-01

    In situ or on-chip protein array methods use cell free expression systems to produce proteins directly onto an immobilising surface from co-distributed or pre-arrayed DNA or RNA, enabling protein arrays to be created on demand. These methods address three issues in protein array technology: (i) efficient protein expression and availability, (ii) functional protein immobilisation and purification in a single step and (iii) protein on-chip stability over time. By simultaneously expressing and immobilising many proteins in parallel on the chip surface, the laborious and often costly processes of DNA cloning, expression and separate protein purification are avoided. Recently employed methods reviewed are PISA (protein in situ array) and NAPPA (nucleic acid programmable protein array) from DNA and puromycin-mediated immobilisation from mRNA. PMID:18207731

  5. In situ bioremediation of Hanford groundwater

    SciTech Connect

    Skeen, R.S.; Roberson, K.R.; Workman, D.J.; Petersen, J.N.; Shouche, M.

    1992-04-01

    Liquid wastes containing radioactive, hazardous, and regulated chemicals have been generated throughout the 40+ years of operations at the US Department of Energy`s (DOE) Hanford Site. Some of these wastes were discharged to the soil column and many of the waste components, including nitrate, carbon tetrachloride (CCl{sub 4}), and several radionuclides, have been detected in the Hanford groundwater. Current DOE policy prohibits the disposal of contaminated liquids directly to the environment, and remediation of existing contaminated groundwaters may be required. In situ bioremediation is one technology currently being developed at Hanford to meet the need for cost effective technologies to clean groundwater contaminated with CCl{sub 4}, nitrate, and other organic and inorganic contaminants. This paper focuses on the latest results of an on going effort to develop effective in situ remediation strategies through the use of predictive simulations.

  6. Fluorescence In Situ Hybridization on Rice Chromosomes.

    PubMed

    Li, Yafei; Cheng, Zhukuan

    2016-01-01

    Fluorescence in situ hybridization (FISH) has become one of the most important technologies applied in plant molecular cytogenetic research. FISH technique has been not only well applied in physical mapping and genomic studies, but also served as an indispensable tool in tracing the individual chromosome during cell division. This chapter provides protocols for basic FISH analysis using rice as a model, which can also be adapted to other model plant species. PMID:26659957

  7. In-situ studies of nanocatalysis.

    PubMed

    Zhang, Shiran; Nguyen, Luan; Zhu, Yuan; Zhan, Sihui; Tsung, Chia-Kuang Frank; Tao, Franklin Feng

    2013-08-20

    A heterogeneous catalyst in industry consists of nanoparticles with variable crystallite sizes, shapes, and compositions. Its catalytic performance (activity, selectivity, and durability) derives from surface chemistry of catalyst nanoparticles during catalysis. However, the surface chemistry of the catalyst particles during catalysis, termed in-situ information, is a "black box" because of the challenges in characterizing the catalysts during catalysis. The lack of such in-situ information about catalysts has limited the understanding of catalytic mechanisms and the development of catalysts with high selectivity and activity. The challenges in understanding heterogeneous catalysis include measurement of reaction kinetics, identification of reaction intermediates, bridging pressure gap and materials gap. The pressure gap is the difference in surface structure and chemistry between a catalyst during catalysis and under an ultrahigh vacuum (UHV) condition. The materials gap represents the difference between the structural and compositional complexity of industrial catalysts and the well-defined surface of model catalysts of metals or oxides. Development of in-situ characterization using electron spectroscopy and electron microscopy in recent decades has made possible studies of surface chemistry and structure of nanocatalysts under reaction conditions or during catalysis at near ambient pressure. In this Account, we review the new chemistries and structures of nanocatalysts during reactions revealed with in-situ analytical techniques. We discuss changes observed during catalysis including the evolution of composition, oxidation state, phase, and geometric structure of the catalyst surface, and the sintering of catalysts. These surface chemistries and structures have allowed researchers to build a correlation between surface chemistry and structure of active nanocatalysts and their corresponding catalytic performances. Such a correlation provides critical insights for understanding catalysis, optimization of existing nanocatalysts, and development of new nanocatalysts with high activity and selectivity. PMID:23618394

  8. In situ health monitoring of piezoelectric sensors

    NASA Technical Reports Server (NTRS)

    Jensen, Scott L. (Inventor); Drouant, George J. (Inventor)

    2013-01-01

    An in situ health monitoring apparatus may include an exciter circuit that applies a pulse to a piezoelectric transducer and a data processing system that determines the piezoelectric transducer's dynamic response to the first pulse. The dynamic response can be used to evaluate the operating range, health, and as-mounted resonance frequency of the transducer, as well as the strength of a coupling between the transducer and a structure and the health of the structure.

  9. Using vegetation to enhance in situ bioremediation

    SciTech Connect

    Erickson, L.E.; Banks, M.K.; Davis, L.C.; Schwab, A.P.; Muralidharan, N.; Reilley, K.; Tracy, J.C.

    1994-11-01

    Vegetation can enhance in situ bioremediation processes in many applications. Microbial transformations occur in the soil external to the plant roots. Organic contaminants also enter vegetation and are transformed within plants. Research progress is reviewed with emphasis on recent experimental results and mathematical models of contaminant fate in systems where vegetation is present. Evapotranspiration provides a solar driven pump-and-treat system which helps bring contaminants to the rhizosphere and helps contain them on the site. 39 refs., 7 tabs.

  10. Numerical simulation of in situ bioremediation

    SciTech Connect

    Travis, B.J.

    1998-12-31

    Models that couple subsurface flow and transport with microbial processes are an important tool for assessing the effectiveness of bioremediation in field applications. A numerical algorithm is described that differs from previous in situ bioremediation models in that it includes: both vadose and groundwater zones, unsteady air and water flow, limited nutrients and airborne nutrients, toxicity, cometabolic kinetics, kinetic sorption, subgridscale averaging, pore clogging and protozoan grazing.

  11. Making a Hybrid Microfluidic Platform Compatible for In Situ Imaging by Vacuum-Based Techniques

    SciTech Connect

    Yang, Li; Yu, Xiao-Ying; Zhu, Zihua; Thevuthasan, Suntharampillai; Cowin, James P.

    2011-10-26

    A self-contained microfluidic-based device was designed and fabricated for in situ imaging of aqueous surfaces using vacuum techniques. The device is a hybrid between a microfluidic PDMS block and external accessories, all portable on a small platform (10 cm-8 cm). The key feature is that a small aperture with a diameter of 2-3 micrometers is opened to the vacuum, which serves as a detection window for in situ imaging of aqueous surfaces. Vacuum compatibility and temperature drop due to water vaporization are the two most important challenges in this invention. Theoretical calculations and fabrication strategies are presented from multiple design aspects. In addition, results from the time-of-flight secondary ion mass spectrometry (ToF-SIMS) of aqueous surfaces are presented.

  12. The Potassium-Argon Laser Experiment (KArLE): In Situ Geochronology for Planetary Robotic Missions

    NASA Technical Reports Server (NTRS)

    Cohen, Barbara

    2016-01-01

    The Potassium (K) - Argon (Ar) Laser Experiment (KArLE) will make in situ noble-gas geochronology measurements aboard planetary robotic landers and roverss. Laser-Induced Breakdown Spectroscopy (LIBS) is used to measure the K abun-dance in a sample and to release its noble gases; the evolved Ar is measured by mass spectrometry (MS); and rela-tive K content is related to absolute Ar abundance by sample mass, determined by optical measurement of the ablated volume. KArLE measures a whole-rock K-Ar age to 10% or better for rocks 2 Ga or older, sufficient to resolve the absolute age of many planetary samples. The LIBS-MS approach is attractive because the analytical components have been flight proven, do not require further technical development, and provide complementary measurements as well as in situ geochronology.

  13. Autonomous in situ measurements of seawater alkalinity.

    PubMed

    Spaulding, Reggie S; DeGrandpre, Michael D; Beck, James C; Hart, Robert D; Peterson, Brittany; De Carlo, Eric H; Drupp, Patrick S; Hammar, Terry R

    2014-08-19

    Total alkalinity (AT) is an important parameter for describing the marine inorganic carbon system and understanding the effects of atmospheric CO2 on the oceans. Measurements of AT are limited, however, because of the laborious process of collecting and analyzing samples. In this work we evaluate the performance of an autonomous instrument for high temporal resolution measurements of seawater AT. The Submersible Autonomous Moored Instrument for alkalinity (SAMI-alk) uses a novel tracer monitored titration method where a colorimetric pH indicator quantifies both pH and relative volumes of sample and titrant, circumventing the need for gravimetric or volumetric measurements. The SAMI-alk performance was validated in the laboratory and in situ during two field studies. Overall in situ accuracy was -2.2 ± 13.1 μmol kg(-1) (n = 86), on the basis of comparison to discrete samples. Precision on duplicate analyses of a carbonate standard was ±4.7 μmol kg(-1) (n = 22). This prototype instrument can measure in situ AT hourly for one month, limited by consumption of reagent and standard solutions. PMID:25051401

  14. In situ denitrification in controlled landfill systems

    SciTech Connect

    Onay, T.T.; Pohland, F.G.

    1996-11-01

    The characteristics of leachate from landfill disposal sites vary according to the operational stage of the landfill. Leachates from old landfills are often rich in ammonia nitrogen due to the hydrolysis and fermentation of nitrogenous fractions of biodegradable refuse substrates. The relative concentration accumulating as stabilization progresses is also influenced by washout as leachate is collected and removed for external treatment. However, in landfills operated as bioreactors with leachate containment, collection and in situ recirculation to accelerate decomposition of readily available organic fractions of the refuse, leachate ammonia nitrogen concentrations may accumulate to much higher levels. High leachate ammonia nitrogen concentrations in landfill leachate have been reported, resulting in separate treatment challenges if direct discharge to either land or receiving waters is practiced. External treatment options for landfill leachate may involve complex physical-chemical and/or biological processes for removal of both high-strength organic and inorganic fractions, including nitrogen. Such separate leachate treatment systems are often costly and difficult to control on a continuum. Therefore, this study focused on the investigation of landfill ammonia nitrogen generation patterns, and the potential for its in situ attenuation and conversion in landfills constructed to permit sequential nitrification and denitrification using leachate recirculation. Accordingly, the landfill is constructed and operated as a controlled bioreactor system, with opportunity to convert ammonia to nitrate by nitrification and nitrate to nitrogen gas by denitrification. The results presented in this paper focus on in situ landfill denitrification of nitrified ammonia.

  15. In Situ Measurement of Aerosol Extinction

    NASA Technical Reports Server (NTRS)

    Strawa, Anthony W.; Castaneda, R.; Owano, T. G.; Bear, D.; Gore, Warren J. (Technical Monitor)

    2001-01-01

    Aerosols are important contributors to the radiative forcing in the atmosphere. Much of the uncertainty in our knowledge of climate forcing is due to uncertainties in the radiative forcing due to aerosols as illustrated in the IPCC reports of the last ten years. Improved measurement of aerosol optical properties, therefore, is critical to an improved understanding of atmospheric radiative forcing. Additionally, attempts to reconcile in situ and remote measurements of aerosol radiative properties have generally not been successful. This is due in part to the fact that it has been impossible to measure aerosol extinction in situ in the past. In this presentation we introduce a new instrument that employs the techniques used in cavity ringdown spectroscopy to measure the aerosol extinction and scattering coefficients in situ. A prototype instrument has been designed and tested in the lab and the field. It is capable of measuring aerosol extinction coefficient to 2x10(exp -6) per meter. This prototype instrument is described and results are presented.

  16. In situ ion irradiation of zirconium carbide

    NASA Astrophysics Data System (ADS)

    Ulmer, Christopher J.; Motta, Arthur T.; Kirk, Mark A.

    2015-11-01

    Zirconium carbide (ZrC) is a candidate material for use in one of the layers of TRISO coated fuel particles to be used in the Generation IV high-temperature, gas-cooled reactor, and thus it is necessary to study the effects of radiation damage on its structure. The microstructural evolution of ZrCx under irradiation was studied in situ using the Intermediate Voltage Electron Microscope (IVEM) at Argonne National Laboratory. Samples of nominal stoichiometries ZrC0.8 and ZrC0.9 were irradiated in situ using 1 MeV Kr2+ ions at various irradiation temperatures (T = 20 K-1073 K). In situ experiments made it possible to continuously follow the evolution of the microstructure during irradiation using diffraction contrast imaging. Images and diffraction patterns were systematically recorded at selected dose points. After a threshold dose during irradiations conducted at room temperature and below, black-dot defects were observed which accumulated until saturation. Once created, the defect clusters did not move or get destroyed during irradiation so that at the final dose the low temperature microstructure consisted only of a saturation density of small defect clusters. No long-range migration of the visible defects or dynamic defect creation and elimination were observed during irradiation, but some coarsening of the microstructure with the formation of dislocation loops was observed at higher temperatures. The irradiated microstructure was found to be only weakly dependent on the stoichiometry.

  17. In situ rheology of yeast biofilms.

    PubMed

    Brugnoni, Lorena I; Tarifa, María C; Lozano, Jorge E; Genovese, Diego

    2014-01-01

    The aim of the present work was to investigate the in situ rheological behavior of yeast biofilms growing on stainless steel under static and turbulent flow. The species used (Rhodototula mucilaginosa, Candida krusei, Candida kefyr and Candida tropicalis) were isolated from a clarified apple juice industry. The flow conditions impacted biofilm composition over time, with a predominance of C. krusei under static and turbulent flow. Likewise, structural variations occurred, with a tighter appearance under dynamic flow. Under turbulent flow there was an increase of 112 μm in biofilm thickness at 11 weeks (p < 0.001) and cell morphology was governed by hyphal structures and rounded cells. Using the in situ growth method introduced here, yeast biofilms were determined to be viscoelastic materials with a predominantly solid-like behavior, and neither this nor the G'0 values were significantly affected by the flow conditions or the growth time, and at large deformations their weak structure collapsed beyond a critical strain of about 1.5-5%. The present work could represent a starting point for developing in situ measurements of yeast rheology and contribute to a thin body of knowledge about fungal biofilm formation. PMID:25428768

  18. Practical application of in situ aerosol measurement

    SciTech Connect

    O`Hern, T.J.; Rader, D.J.

    1993-09-01

    The use of in situ, real-time measurement techniques permits the characterization of airborne droplets and particles under conditions where traditional sampling methods can fail. For example, sampling method rely on the ability to sample and transport particles without biasing the properties of interest, and often are not applicable in harsh environment. Although in situ methods offer unique opportunities in these cases, these techniques introduce new concerns and must be used carefully if accurate measurement are to be made. Several in situ measurement techniques are reviewed here. As the field is rapidly evolving, the discussion is limited to those techniques which: (1) are commercially available, (2) provide real-time output, (3) measure the aerosol size distribution. Discussion is divided between single particle counters (which provide a flux-based or temporal measurement) and ensemble techniques (which provide a concentration-based or spatial measurement). Specific techniques discussed include phase Doppler, Mie scattering, and Fraunhofer diffraction, and commercial instruments based on these techniques.

  19. Predicting the denitrification capacity of sandy aquifers from in situ measurements using push-pull 15N tracer tests

    NASA Astrophysics Data System (ADS)

    Eschenbach, W.; Well, R.; Walther, W.

    2014-12-01

    Knowledge about the spatial variability of in situ denitrification rates (Dr(in situ)) and their relation to the denitrification capacity in nitrate-contaminated aquifers is crucial to predict the development of groundwater quality. Therefore, 28 push-pull 15N tracer tests for the measurement of in situ denitrification rates were conducted in two sandy Pleistocene aquifers in Northern Germany. The 15N analysis of denitrification derived 15N labelled N2 and N2O dissolved in water samples collected during the push-pull 15N tracer tests was performed by isotope ratio mass spectrometry (IRMS) in the lab and additionally for some tracer tests online in the field with a quadrupole membrane inlet mass spectrometer (MIMS), in order to test the feasibility of on-site real-time 15N analysis. Aquifer material from the same locations and depths as the push-pull injection points was incubated and the initial and cumulative denitrification after one year of incubation (Dcum(365)) as well as the stock of reduced compounds (SRC) was compared with in situ measurements of denitrification. This was done to derive transfer functions suitable to predict Dcum(365) and SRC from Dr(in situ). Dr(in situ) ranged from 0 to 51.5 μg N kg-1 d-1. Denitrification rates derived from on-site isotope analysis using membrane-inlet mass spectrometry satisfactorily coincided with laboratory analysis by conventional isotope ratio mass spectrometry, thus proving the feasibility of in situ analysis. Dr(in situ) was significantly higher in the sulphidic zone of both aquifers compared to the zone of non-sulphidic aquifer material. Overall, regressions between the Dcum(365) and SRC of the tested aquifer material with Dr(in situ) exhibited only a modest linear correlation for the full data set. But the predictability of Dcum(365) and SRC from Dr(in situ) data clearly increased for aquifer samples from the zone of NO3--bearing groundwater. In the NO3--free aquifer zone a lag phase of denitrification after NO3- injections was observed, which confounded the relationship between reactive compounds and in situ denitrification activity. This finding was attributed to adaptation processes in the microbial community after NO3- injections. Exemplarily, it was demonstrated that the microbial community in the NO3--free zone close below the NO3--bearing zone can be adapted to denitrification by amending wells with NO3--injections for an extended period. In situ denitrification rates were 30 to 65% higher after pre-conditioning with NO3-. Results from this study suggest that such pre-conditioning is crucial for the measurement of Dr(in situ) in deeper aquifer material from the NO3--free groundwater zone and thus for the prediction of Dcum(365) and SRC from Dr(in situ).

  20. DEMONSTRATION BULLETIN: IN SITU ELECTROKINETIC EXTRACTION SYSTEM - SANDIA NATIONAL LABORATORIES

    EPA Science Inventory

    Sandia National Laboratories (SNL) has developed an in situ soil remediation system that uses electrokinetic principles to remediate hexavalent chromium-contaminated unsaturated or partially saturated soils. The technology involves the in situ application of direct current to the...

  1. Analytical chemistry and the cone penetrometer : in situ chemical characterization of the subsurface.

    SciTech Connect

    Aldstadt, J. H.; Martin, A. F.; Environmental Research

    1997-01-01

    The development of novel microanalytical techniques for in situ chemical characterization of the terrestrial subsurface environment has grown significantly over the last decade, particularly those instruments that are interfaced to the cone penetrometer. Cone penetrometer testing (CPT) has emerged as an effective means to introduce samplers and probes for in situ analysis of contaminants in soil and groundwater matrices. A variety of in situ chemical samplers for CPT have been developed that can be driven into the subsurface to collect soil gas, groundwater, or soil samples at depth, thus providing a means of determining the vertical and horizontal extent of contamination. Cone penetrometer testing is also being explored as a means to deliver in situ subsurface sensor probes, including probes based on laser-induced fluorescence, Raman, and infrared spectroscopies for organics; on laser-induced breakdown and X-ray fluorescence spectroscopies for heavy metals; and on passive gamma-ray spectroscopy for radionuclides. The range of analytical technologies used in CPT for the determination of organic and inorganic species in the subsurface is described.

  2. In-situ droplet monitoring for self-tuning spectrometers

    DOEpatents

    Montaser, Akbar (Potomac, MD); Jorabchi, Kaveh (Arlington, VA); Kahen, Kaveh (Kleinburg, CA)

    2010-09-28

    A laser scattering based imaging technique is utilized in order to visualize the aerosol droplets in an inductively coupled plasma (ICP) torch from an aerosol source to the site of analytical measurements. The resulting snapshots provide key information about the spatial distribution of the aerosol introduced by direct and indirect injection devices: 1) a direct injection high efficiency nebulizer (DIHEN); 2) a large-bore DIHEN (LB-DIHEN); and 3) a PFA microflow nebulizer with a PFA Scott-type spray chamber. Moreover, particle image velocimetry (PIV) is used to study the in-situ behavior of the aerosol before interaction with, for example, plasma, while the individual surviving droplets are explored by particle tracking velocimetry (PTV). Further, the velocity distribution of the surviving droplets demonstrates the importance of the initial droplet velocities in complete desolvation of the aerosol for optimum analytical performance in ICP spectrometries. These new observations are important in the design of the next-generation direct injection devices for lower sample consumption, higher sensitivity, lower noise levels, suppressed matrix effects, and for developing smart spectrometers. For example, a controller can be provided to control the output of the aerosol source by controlling the configuration of the source or the gas flow rate via feedback information concerning the aerosol.

  3. 30 CFR 828.11 - In situ processing: Performance standards.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... in situ processing activities shall comply with 30 CFR 817 and this section. (b) In situ processing... processing activities shall submit for approval as part of the application for permit under 30 CFR 785.22... 30 Mineral Resources 3 2011-07-01 2011-07-01 false In situ processing: Performance standards....

  4. 30 CFR 828.11 - In situ processing: Performance standards.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... in situ processing activities shall comply with 30 CFR 817 and this section. (b) In situ processing... processing activities shall submit for approval as part of the application for permit under 30 CFR 785.22... 30 Mineral Resources 3 2013-07-01 2013-07-01 false In situ processing: Performance standards....

  5. 30 CFR 828.11 - In situ processing: Performance standards.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... in situ processing activities shall comply with 30 CFR 817 and this section. (b) In situ processing... processing activities shall submit for approval as part of the application for permit under 30 CFR 785.22... 30 Mineral Resources 3 2012-07-01 2012-07-01 false In situ processing: Performance standards....

  6. 30 CFR 828.11 - In situ processing: Performance standards.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... in situ processing activities shall comply with 30 CFR 817 and this section. (b) In situ processing... processing activities shall submit for approval as part of the application for permit under 30 CFR 785.22... 30 Mineral Resources 3 2010-07-01 2010-07-01 false In situ processing: Performance standards....

  7. 30 CFR 828.11 - In situ processing: Performance standards.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... in situ processing activities shall comply with 30 CFR 817 and this section. (b) In situ processing... processing activities shall submit for approval as part of the application for permit under 30 CFR 785.22... 30 Mineral Resources 3 2014-07-01 2014-07-01 false In situ processing: Performance standards....

  8. Influence of in situ ultrasound treatment during ion implantation on formation of silver nanoparticles in silica

    SciTech Connect

    Romanyuk, Andriy; Spassov, Vladislav; Melnik, Viktor

    2006-02-01

    We report on the effect of in situ ultrasound treatment on the clustering process of silver atoms in ion-implanted SiO{sub 2}. Cross-sectional transmission electron microscopy shows single-crystal Ag spheres with an increased cluster size when prepared using ultrasound vibrations. Time-of-flight secondary-ion-mass spectrometry demonstrates an enhanced yield of [Ag{sub 2}]{sup 216} complexes in structures treated with acoustic waves. An analysis of the influence of ultrasound on defect reaction kinetics as well as on different stages of the clustering process is performed.

  9. Coordinated in Situ Analyses of Organic Nanoglobules in the Sutter's Mill Meteorite

    NASA Technical Reports Server (NTRS)

    Nakamura-Messenger, K.; Messenger, S.; Keller, L. P.; Clemett, S. J.; Nguyen, A. N.; Gibson, E. K.

    2013-01-01

    The Sutter's Mill meteorite is a newly fallen carbonaceous chondrite that was collected and curated quickly after its fall. Preliminary petrographic and isotopic investigations suggest affinities to the CM2 carbonaceous chondrites. The primitive nature of this meteorite and its rapid recovery provide an opportunity to investigate primordial solar system organic matter in a unique new sample. Here we report in-situ analyses of organic nanoglobules in the Sutter's Mill meteorite using UV fluorescence imaging, Fourier-transform infrared spectroscopy (FTIR), scanning transmission electron microscopy (STEM), NanoSIMS, and ultrafast two-step laser mass spectrometry (ultra-L2MS).

  10. In-situ thermal testing program strategy

    SciTech Connect

    1995-06-01

    In the past year the Yucca Mountain Site Characterization Project has implemented a new Program Approach to the licensing process. The Program Approach suggests a step-wise approach to licensing in which the early phases will require less site information than previously planned and necessitate a lesser degree of confidence in the longer-term performance of the repository. Under the Program Approach, the thermal test program is divided into two principal phases: (1) short-term in situ tests (in the 1996 to 2000 time period) and laboratory thermal tests to obtain preclosure information, parameters, and data along with bounding information for postclosure performance; and (2) longer-term in situ tests to obtain additional data regarding postclosure performance. This effort necessitates a rethinking of the testing program because the amount of information needed for the initial licensing phase is less than previously planned. This document proposes a revised and consolidated in situ thermal test program (including supporting laboratory tests) that is structured to meet the needs of the Program Approach. A customer-supplier model is used to define the Project data needs. These data needs, along with other requirements, were then used to define a set of conceptual experiments that will provide the required data within the constraints of the Program Approach schedule. The conceptual thermal tests presented in this document represent a consolidation and update of previously defined tests that should result in a more efficient use of Project resources. This document focuses on defining the requirements and tests needed to satisfy the goal of a successful license application in 2001, should the site be found suitable.

  11. In situ surface biodegradation of restorative materials.

    PubMed

    Padovani, Gc; Fcio, Sbp; Ambrosano, Gmb; Sinhoreti, Mac; Puppin-Rontani, Rm

    2014-01-01

    SUMMARY This study aimed to evaluate the surface characteristics of restorative materials (roughness, hardness, chemical changes by energy-dispersive spectroscopy [EDX], and scanning electron microscopy [SEM]) submitted to in situ biodegradation. Fifteen discs of each material (IPS e.max [EM], Filtek Supreme [FS], Vitremer [VI], Ketac Molar Easymix [KM], and Amalgam GS-80 [AM]) were fabricated in a metallic mold (4.0 mm 1.5 mm). Roughness, hardness, SEM, and EDX were then evaluated. Fifteen healthy volunteers used a palatal device containing one disc of each restorative material for seven days. After the biodegradation, the roughness, hardness, SEM, and EDX were once again evaluated. Data obtained from the roughness and hardness evaluations were submitted to Kolmogorov-Smirnov and Tukey-Kramer tests (p<0.05). All esthetic restorative materials showed a significant increase in the roughness after biodegradation. Before biodegradation, significant differences in the hardness among the materials were seen: EM>AM>FS>KM>VI. After biodegradation, the hardness was significantly altered among the materials studied: EM>AM>FS=KM>VI, along with a significant increase in the hardness for AM, KM, and VI. SEM images indicated degradation on the surface of all materials, showing porosities, cracks, and roughness. Furthermore, after biodegradation, FS showed the presence of Cl, K, and Ca on the surface, while F was not present on the VI and KM surfaces. EM and AM did not have alterations in their chemical composition after biodegradation. It was concluded that the dental biofilm accumulation in situ on different restorative materials is a material-dependent parameter. Overall, all materials changed after biodegradation: esthetic restorative materials showed increased roughness, confirmed by SEM, and the ionomer materials and silver amalgam showed a significantly higher hardness. Finally, the initial chemical composition of the composite resin and ionomer materials evaluated was significantly altered by the action of the biofilm in situ. PMID:24555699

  12. Robust and efficient in situ quantum control

    NASA Astrophysics Data System (ADS)

    Ferrie, Christopher; Moussa, Osama

    2015-05-01

    Precision control of quantum systems is the driving force for both quantum technology and the probing of physics at the quantum and nanoscale levels. We propose an implementation-independent method for in situ quantum control that leverages recent advances in the direct estimation of quantum gate fidelity. Our algorithm takes account of the stochasticity of the problem, is suitable for closed-loop control, and requires only a constant number of fidelity-estimating experiments per iteration independent of the dimension of the control space. It is efficient and robust to both statistical and technical noise.

  13. In situ, noninvasive characterization of superhydrophobic coatings

    NASA Astrophysics Data System (ADS)

    Samaha, Mohamed A.; Ochanda, Fredrick O.; Tafreshi, Hooman Vahedi; Tepper, Gary C.; Gad-el-Hak, Mohamed

    2011-04-01

    Light scattering was used to measure the time-dependent loss of air entrapped within a submerged microporous hydrophobic surface subjected to different environmental conditions. The loss of trapped air resulted in a measurable decrease in surface reflectivity and the kinetics of the process was determined in real time and compared to surface properties, such as porosity and morphology. The light-scattering results were compared with measurements of skin-friction drag, static contact angle, and contact-angle hysteresis. The in situ, noninvasive optical technique was shown to correlate well with the more conventional methods for quantifying surface hydrophobicity, such as flow slip and contact angle.

  14. In-Situ Wire Damage Detection System

    NASA Technical Reports Server (NTRS)

    Williams, Martha K. (Inventor); Roberson, Luke B. (Inventor); Tate, Lanetra C. (Inventor); Smith, Trent M. (Inventor); Gibson, Tracy L. (Inventor); Jolley, Scott T. (Inventor); Medelius, Pedro J. (Inventor)

    2014-01-01

    An in-situ system for detecting damage in an electrically conductive wire. The system includes a substrate at least partially covered by a layer of electrically conductive material forming a continuous or non-continuous electrically conductive layer connected to an electrical signal generator adapted to delivering electrical signals to the electrically conductive layer. Data is received and processed to identify damage to the substrate or electrically conductive layer. The electrically conductive material may include metalized carbon fibers, a thin metal coating, a conductive polymer, carbon nanotubes, metal nanoparticles or a combination thereof.

  15. Spatially controlled, in situ synthesis of polymers

    DOEpatents

    Caneba, Gerard T.; Tirumala, Vijaya Raghavan; Mancini, Derrick C.; Wang, Hsien-Hau

    2005-03-22

    An in situ polymer microstructure formation method. The monomer mixture is polymerized in a solvent/precipitant through exposure to ionizing radiation in the absence any chemical mediators. If an exposure mask is employed to block out certain regions of the radiation cross section, then a patterned microstructure is formed. The polymerization mechanism is based on the so-called free-radical retrograde-precipitation polymerization process, in which polymerization occurs while the system is phase separating above the lower critical solution temperature. This method was extended to produce a crosslinked line grid-pattern of poly (N-isopropylacrylamide), which has been known to have thermoreversible properties.

  16. In situ hydrogen loading on zirconium powder

    PubMed Central

    Maimaitiyili, Tuerdi; Blomqvist, Jakob; Steuwer, Axel; Bjerkén, Christina; Zanellato, Olivier; Blackmur, Matthew S.; Andrieux, Jérôme; Ribeiro, Fabienne

    2015-01-01

    For the first time, various hydride phases in a zirconium–hydrogen system have been prepared in a high-energy synchrotron X-ray radiation beamline and their transformation behaviour has been studied in situ. First, the formation and dissolution of hydrides in commercially pure zirconium powder were monitored in real time during hydrogenation and dehydrogenation, then whole pattern crystal structure analysis such as Rietveld and Pawley refinements were performed. All commonly reported low-pressure phases presented in the Zr–H phase diagram are obtained from a single experimental arrangement. PMID:26134803

  17. Increased levels of gamma-glutamylamines in Huntington disease CSF.

    PubMed

    Jeitner, Thomas M; Matson, Wayne R; Folk, John E; Blass, John P; Cooper, Arthur J L

    2008-07-01

    Transglutaminases (TGases) catalyze several reactions with protein substrates, including formation of gamma-glutamyl-epsilon-lysine cross-links and gamma-glutamylpolyamine residues. The resulting gamma-glutamylamines are excised intact during proteolysis. TGase activity is altered in several diseases, highlighting the importance of in situ enzymatic determinations. Previous work showed that TGase activity (as measured by an in vitro assay) and free gamma-glutamyl-epsilon-lysine levels are elevated in Huntington disease (HD) and that gamma-glutamyl-epsilon-lysine is increased in HD CSF. Although free gamma-glutamyl-epsilon-lysine was used in these studies as an index of in situ TGase activity, gamma-glutamylpolyamines may also be diagnostic. We have devised methods for the simultaneous determination of four gamma-glutamylamines in CSF: gamma-glutamyl-epsilon-lysine, gamma-glutamylspermidine, gamma-glutamylputrescine, and bis-gamma-glutamylputrescine and showed that all are present in normal human CSF at concentrations of approximately 150, 670, 40, and 240 nM, respectively. The high gamma-glutamylspermidine/gamma-glutamylputrescine and gamma-glutamylspermidine/bis-gamma-glutamylputrescine ratios presumably reflect in part the large spermidine to putrescine mole ratio in human brain. We also showed that all four gamma-glutamylamines are elevated in HD CSF. Our findings support the hypotheses that (i) gamma-glutamylpolyamines are reflective of TGase activity in human brain, (ii) polyamination is an important post-translational modification of brain proteins, and (iii) TGase-catalyzed modification of proteins is increased in HD brain. PMID:18422943

  18. In situ expression of cytokines in human heart allografts.

    PubMed Central

    Van Hoffen, E.; Van Wichen, D.; Stuij, I.; De Jonge, N.; Klpping, C.; Lahpor, J.; Van Den Tweel, J.; Gmelig-Meyling, F.; De Weger, R.

    1996-01-01

    Although allograft rejection, the major complication of human organ transplantation, has been extensively studied, little is known about the exact cellular localization of the cytokine expression inside the graft during rejection. Therefore, we used in situ hybridization and immunohistochemistry to study local cytokine mRNA and protein expression in human heart allografts, in relation to the phenotypical characteristics of the cellular infiltrate. Clear expression of mRNA for interleukin (IL)-6, IL-8, IL-9, and IL-10 and weak expression for IL-2, IL-4, IL-5, and tumor necrosis factor (TNF)-alpha was detected in biopsies exhibiting high rejection grades (grade 3A/B). Also at lower grades of rejection, mRNA for IL-6 and IL-9 was present. Some mRNA for IL-1 beta, TNF-beta, and interferon (IFN)-gamma was detected in only a few biopsies. Using immunohistochemistry, IL-2, IL-3, and IL-10 protein was detected in biopsies with high rejection grades, whereas few cells expressed IL-6, IL-8, and IFN-gamma. In biopsies with lower grades of rejection, a weaker expression of these cytokines was observed. IL-4 was hardly detected in any of the biopsies. The level of IL-12 expression was equal in all biopsies. Although mRNA expression of several cytokines was expressed at a low level compared with the protein level of those cytokines, there was a good correlation between localization of cytokine mRNA and protein. Expression of IL-2, IL-4, IL-5, TNF-alpha, and IFN-gamma was mainly detected in lymphocytes. IL-3, IL-6, IL-10, and IL-12 were not detected or not only detected in lymphocytes but also in other stromal elements (eg, macrophages). Macrophage production of IL-3 and IL-12 was confirmed by immunofluorescent double labeling with CD68. We conclude that cardiac allograft rejection is not simply regulated by T helper cell cytokine production, but other intragraft elements contribute considerably to this process. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:8952534

  19. Molecular cytogenetics using fluorescence in situ hybridization

    SciTech Connect

    Gray, J.W.; Kuo, Wen-Lin; Lucas, J.; Pinkel, D.; Weier, H-U.; Yu, Loh-Chung.

    1990-12-07

    Fluorescence in situ hybridization (FISH) with chromosome-specific probes enables several new areas of cytogenetic investigation by allowing visual determination of the presence and normality of specific genetic sequences in single metaphase or interphase cells. in this approach, termed molecular cytogenetics, the genetic loci to be analyzed are made microscopically visible in single cells using in situ hybridization with nucleic acid probes specific to these loci. To accomplish this, the DNA in the target cells is made single stranded by thermal denaturation and incubated with single-stranded, chemically modified probe under conditions where the probe will anneal only with DNA sequences to which it has high DNA sequence homology. The bound probe is then made visible by treatment with a fluorescent reagent such as fluorescein that binds to the chemical modification carried by the probe. The DNA to which the probe does not bind is made visible by staining with a dye such as propidium iodide that fluoresces at a wavelength different from that of the reagent used for probe visualization. We show in this report that probes are now available that make this technique useful for biological dosimetry, prenatal diagnosis and cancer biology. 31 refs., 3 figs.

  20. In situ biodegradation of creosote contaminated soils

    SciTech Connect

    Nelson, M.D.; Maier, W.J.

    1996-11-01

    The Reilly Tar and Chemical operated a coal tar and wood processing plant on a 80 acre site from 1917 until plant closure in 1972. Reilly disposed of wastewater from the operation in a network of ditches which discharged into a swampy area south of the Reilly site. The contamination from these sources has migrated downward into the groundwater, contaminating the shallow aquifer underlying the site. Through multi-aquifer wells the contamination has entered deeper aquifers including the Prairie Duchien-Jordan aquifer. Ongoing pump and treat operations are not viewed as ecologically or economically sound long-term solutions. All parties agreed that programs to eliminate polluting materials at the source to speed the cleanup process and minimize the potential leakage of the pollutants into interconnected aquifers is desirable. In this connection, a study was completed to examine whether source materials can be eliminated by on site and/or in situ bioremediation. In order to engineer a bioremediation strategy which optimizes degradation rates it is extremely important to determine the rate limiting steps in the treatment process. The results of this study show that if sufficient oxygen can be provided, in situ bioremediation could be effective at reducing or eliminating offsite pollutant migration and effectively remove the sources of the groundwater contamination.

  1. Speckle interferometry in situ: a feasibility study

    NASA Astrophysics Data System (ADS)

    Facchini, Massimo

    1998-06-01

    Speckle interferometry has been successfully used in many cases where a non-contact analysis of a surface's deformation state was required. This technique has been mostly applied in favorable environment, where the absence of vibrations and a reduced ambient illumination could be assured, and for the observation of areas being not in excess of some dm2. When inspecting larger surfaces, all the problems related to the spatial resolution, to the limited sensitivity of the acquisition system, to the amount of illumination and to the extension of the observed area, should be taken into account. If the observed surface belongs to a structure directly positioned in-situ, problems of vibration, air turbulence, or ambient light saturation, become very restrictive for the application of the method. After a brief introduction about the theoretical principles of speckle interferometry, some main problems related to the inspection on quite large surfaces in-situ discussed. The problem is treated with the help of some simulations, possible solutions are proposed and some applications are presented. This work is the result of a joint collaboration between may institutes and research centers in the framework of a European project named VISILAS. Special fields of application foreseen for this project are civil engineering, aircraft industry, ship building and power plants for energy production.

  2. In situ SU-8 silver nanocomposites

    PubMed Central

    Uthuppu, Basil; Jakobsen, Mogens H

    2015-01-01

    Summary Nanocomposite materials containing metal nanoparticles are of considerable interest in photonics and optoelectronics applications. However, device fabrication of such materials always encounters the challenge of incorporation of preformed nanoparticles into photoresist materials. As a solution to this problem, an easy new method of fabricating silver nanocomposites by an in situ reduction of precursors within the epoxy-based photoresist SU-8 has been developed. AgNO3 dissolved in acetonitrile and mixed with the epoxy-based photoresist SU-8 forms silver nanoparticles primarily during the pre- and post-exposure soft bake steps at 95 C. A further high-temperature treatment at 300 C resulted in the formation of densely homogeneously distributed silver nanoparticles in the photoresist matrix. No particle growth or agglomeration of nanoparticles is observed at this point. The reported new in situ silver nanocomposite materials can be spin coated as homogeneous thin films and structured by using UV lithography. A resolution of 5 m is achieved in the lithographic process. The UV exposure time is found to be independent of the nanoparticle concentration. The fabricated silver nanocomposites exhibit high plasmonic responses suitable for the development of new optoelectronic and optical sensing devices. PMID:26425416

  3. Biophotonic in situ sensor for plant leaves

    SciTech Connect

    Conejo, Elian; Frangi, Jean-Pierre; Rosny, Gilles de

    2010-04-01

    Knowledge of the water concentration of plants can be helpful in several environmental and agricultural domains. There are many methods for the determination of water content in plant leaves; however, most of them give a relative moisture level or an analytical measure after a previous calibration procedure. Even for other biochemical compounds such as dry matter or chlorophyll, the measurement techniques could be destructive. For this reason, a nondestructive method has been developed to measure the biochemical compounds of a plant leaf, using an infrared spectroscopy technique. One important advantage is the simplicity of the device (RAdiometre portatif de Mesure In Situ, RAMIS) and its capability to perform measurements in situ. The prototype is a leaf-clip configuration and is made of LEDs at five wavelengths (656, 721, 843, 937, and 1550 nm), and a silicon/germanium photosensor. To compute the water content of vegetative leaves, the radiative transfer model PROSPECT was implemented. This model can accurately predict spectral transmittances in the 400 nm to 2500 nm spectral region as a function of the principal leaf biochemical contents: water, dry matter, and chlorophyll. Using the transmittance measured by RAMIS into an inversion procedure of PROSPECT: A Model of Leaf Optical Properties Spectra, we are able to compute the values of water contents that show an agreement with the water contents measured directly using dry weight procedures. This method is presented as a possibility to estimate other leaf biochemical compounds using appropriate wavelengths.

  4. Inherently safe in situ uranium recovery.

    SciTech Connect

    Krumhansl, James Lee; Beauheim, Richard Louis; Brady, Patrick Vane; Arnold, Bill Walter; Kanney, Joseph F.; McKenna, Sean Andrew

    2009-05-01

    Expansion of uranium mining in the United States is a concern to some environmental groups and sovereign Native American Nations. An approach which may alleviate some problems is to develop inherently safe in situ uranium recovery ('ISR') technologies. Current ISR technology relies on chemical extraction of trace levels of uranium from aquifers that, once mined, can still contain dissolved uranium and other trace metals that are a health concern. Existing ISR operations are few in number; however, high uranium prices are driving the industry to consider expanding operations nation-wide. Environmental concerns and enforcement of the new 30 ppb uranium drinking water standard may make opening new mining operations more difficult and costly. Here we propose a technological fix: the development of inherently safe in situ recovery (ISISR) methods. The four central features of an ISISR approach are: (1) New 'green' leachants that break down predictably in the subsurface, leaving uranium, and associated trace metals, in an immobile form; (2) Post-leachant uranium/metals-immobilizing washes that provide a backup decontamination process; (3) An optimized well-field design that increases uranium recovery efficiency and minimizes excursions of contaminated water; and (4) A combined hydrologic/geochemical protocol for designing low-cost post-extraction long-term monitoring. ISISR would bring larger amounts of uranium to the surface, leave fewer toxic metals in the aquifer, and cost less to monitor safely - thus providing a 'win-win-win' solution to all stakeholders.

  5. GAS TURBINE REHEAT USING IN SITU COMBUSTION

    SciTech Connect

    D.M. Bachovchin; T.E. Lippert; R.A. Newby P.G.A. Cizmas

    2004-05-17

    In situ reheat is an alternative to traditional gas turbine reheat design in which fuel is fed through airfoils rather than in a bulky discrete combustor separating HP and LP turbines. The goals are to achieve increased power output and/or efficiency without higher emissions. In this program the scientific basis for achieving burnout with low emissions has been explored. In Task 1, Blade Path Aerodynamics, design options were evaluated using CFD in terms of burnout, increase of power output, and possible hot streaking. It was concluded that Vane 1 injection in a conventional 4-stage turbine was preferred. Vane 2 injection after vane 1 injection was possible, but of marginal benefit. In Task 2, Combustion and Emissions, detailed chemical kinetics modeling, validated by Task 3, Sub-Scale Testing, experiments, resulted in the same conclusions, with the added conclusion that some increase in emissions was expected. In Task 4, Conceptual Design and Development Plan, Siemens Westinghouse power cycle analysis software was used to evaluate alternative in situ reheat design options. Only single stage reheat, via vane 1, was found to have merit, consistent with prior Tasks. Unifying the results of all the tasks, a conceptual design for single stage reheat utilizing 24 holes, 1.8 mm diameter, at the trailing edge of vane 1 is presented. A development plan is presented.

  6. In situ bioremediation under high saline conditions

    SciTech Connect

    Bosshard, B.; Raumin, J.; Saurohan, B.

    1995-12-31

    An in situ bioremediation treatability study is in progress at the Salton Sea Test Base (SSTB) under the NAVY CLEAN 2 contract. The site is located in the vicinity of the Salon Sea with expected groundwater saline levels of up to 50,000 ppm. The site is contaminated with diesel, gasoline and fuel oils. The treatability study is assessing the use of indigenous heterotrophic bacteria to remediate petroleum hydrocarbons. Low levels of significant macro nutrients indicate that nutrient addition of metabolic nitrogen and Orthophosphate are necessary to promote the process, requiring unique nutrient addition schemes. Groundwater major ion chemistry indicates that precipitation of calcium phosphorus compounds may be stimulated by air-sparging operations and nutrient addition, which has mandated the remedial system to include pneumatic fracturing as an option. This presentation is tailored at an introductory level to in situ bioremediation technologies, with some emphasize on innovations in sparge air delivery, dissolved oxygen uptake rates, nutrient delivery, and pneumatic fracturing that should keep the expert`s interest.

  7. In situ PEM fuel cell water measurements

    SciTech Connect

    Borup, Rodney L; Mukundan, Rangachary; Davey, John R; Spendelow, Jacob S; Hussey, Daniel S; Jacobson, David L; Arif, Muhammad

    2009-01-01

    Efficient PEM (Polymer Electrolyte Membrane) fuel cell performance requires effective water management. To achieve a deeper understanding of water transport and performance issues associated with water management, we have conducted in situ water examinations to help understand the effects of components and operations. High Frequency Resistance (HFR), AC Impedance and Neutron imaging were used to measure water content in operating fuel cells, with various conditions, including current density, relative humidity, inlet flows, flow orientation and variable Gas Diffusion Layer (GDL) properties. High resolution neutron radiography was used to image fuel cells during a variety of conditions. The effect of specific operating conditions, including flow direction (co-flow or counter-flow) was examined. Counter-flow operation was found to result in higher water content than co-flow operation, which correlates to lower membrane resistivity. A variety of cells were used to quantify the membrane water in situ during exposure to saturated gases, during fuel cell operation, and during hydrogen pump operation. The quantitative results show lower membrane water content than previous results suggested.

  8. In Situ Instruments: Overview of In Situ Instruments for Deployment in Extreme Environments

    NASA Technical Reports Server (NTRS)

    Taylor, M.; Cardell, G.

    2000-01-01

    This presentation reviews the design and specifications for several instruments for deployment in extreme environments. The instruments are: (1) In Situ Geochronology Instrument, (2) Laser Ablation Sampling Instrument, (3) Micro Hygrometer (4) Micro Lidar, (5) Atmospheric Electron X-Ray Spectrometer and (6) Nuclear Magnetic Resonance Spectrometer. Included in the descriptions are the contact people and the objective of each instrument.

  9. In situ radiation influence on strain measurement performance of Brillouin sensors

    NASA Astrophysics Data System (ADS)

    Pheron, X.; Ouerdane, Y.; Girard, S.; Marcandella, C.; Delepine-Lesoille, S.; Bertrand, J.; Taillade, F.; Merliot, E.; Sikali Mamdem, Y.; Boukenter, A.

    2011-05-01

    A new approach is proposed to monitor in situ the influence of gamma radiations on Brillouin properties of optical fiber extensometers. Experimental results are illustrated with the characterization of two fibers samples up to total dose of about 600Gy. The Brillouin frequency shift remains unaffected at such radiations level, as well as the spectral Brillouin signature or its dependence with strain. Meanwhile, propagation losses increase under radiations with an amplitude related to fiber dopants. The target application is nuclear wastes repository monitoring where higher doses are expected. UV radiation preliminary tests show that compaction phenomenon may occur at such high doses, inducing Brillouin frequency shift up to 20 MHz.

  10. Radiological aspects of in situ uranium recovery

    SciTech Connect

    BROWN, STEVEN H.

    2007-07-01

    In the last few years, there has been a significant increase in the demand for Uranium as historical inventories have been consumed and new reactor orders are being placed. Numerous mineralized properties around the world are being evaluated for Uranium recovery and new mining / milling projects are being evaluated and developed. Ore bodies which are considered uneconomical to mine by conventional methods such as tunneling or open pits, can be candidates for non-conventional recovery techniques, involving considerably less capital expenditure. Technologies such as Uranium in situ leaching in situ recovery (ISL / ISR), have enabled commercial scale mining and milling of relatively small ore pockets of lower grade, and may make a significant contribution to overall world wide uranium supplies over the next ten years. Commercial size solution mining production facilities have operated in the US since 1975. Solution mining involves the pumping of groundwater, fortified with oxidizing and complexing agents into an ore body, solubilizing the uranium in situ, and then pumping the solutions to the surface where they are fed to a processing plant. Processing involves ion exchange and may also include precipitation, drying or calcining and packaging operations depending on facility specifics. This paper presents an overview of the ISR process and the health physics monitoring programs developed at a number of commercial scale ISL / ISR Uranium recovery and production facilities as a result of the radiological character of these processes. Although many radiological aspects of the process are similar to that of conventional mills, conventional-type tailings as such are not generated. However, liquid and solid byproduct materials may be generated and impounded. The quantity and radiological character of these by products are related to facility specifics. Some special monitoring considerations are presented which are required due to the manner in which Radon gas is evolved in the process and the unique aspects of controlling solution flow patterns underground. An overview of the major aspects of the health physics and radiation protection programs that were developed at these facilities are discussed and contrasted to circumstances of the current generation and state of the art of Uranium ISR technologies and facilities. (authors)

  11. Applications of Mass Spectrometry to Lipids and Membranes

    PubMed Central

    Harkewicz, Richard; Dennis, Edward A.

    2012-01-01

    Lipidomics, a major part of metabolomics, constitutes the detailed analysis and global characterization, both spatial and temporal, of the structure and function of lipids (the lipidome) within a living system. As with proteomics, mass spectrometry has earned a central analytical role in lipidomics, and this role will continue to grow with technological developments. Currently, there exist two mass spectrometry-based lipidomics approaches, one based on a division of lipids into categories and classes prior to analysis, the “comprehensive lipidomics analysis by separation simplification” (CLASS), and the other in which all lipid species are analyzed together without prior separation, shotgun. In exploring the lipidome of various living systems, novel lipids are being discovered, and mass spectrometry is helping characterize their chemical structure. Deuterium exchange mass spectrometry (DXMS) is being used to investigate the association of lipids and membranes with proteins and enzymes, and imaging mass spectrometry (IMS) is being applied to the in situ analysis of lipids in tissues. PMID:21469951

  12. Sensitive and Specific In-Situ Sensor for Monitoring Contaminated Water

    SciTech Connect

    Du, Yongzhai; Watson, David B; Whitten, William B; Li, Haiyang; Nazarov, Erkinjun; Xu, Jun

    2010-01-01

    We report on the development of a high-sensitivity and high-specificity sensor, combining membrane extraction, pre-concentration, and gas-chromatographic differential mobility spectrometry (GC/DMS), for in situ detection of chlorinated hydrocarbons in water. Direct in-situ detection was achieved by membrane conversion of aqueous analyte to vapor, followed by vapor spectroscopy using GC/DMS analyzer. The limit of detection (LOD) reaches 0.37 parts per billion in volume (ppbv), or 0.54 ug/L, for aqueous trichloroethylene (TCE) and 1.6 ug/L for perchloroethylene (PCE) by incorporating a preconcentrator between the membrane extraction and GC/DMS detection systems. The high specificity was achieved using two-dimensional separation parameters of GC retention time and DMS compensation voltage. The presence of co-contaminants and foreign contaminants, such as benzene, toluene, CCl4, and CHCl3 did not interfere with the identification of chlorinated hydrocarbons. This highly-sensitive and -specific sensor paves the way for developing field-deployable sensors for in-situ and real-time monitoring of chlorinated hydrocarbons in groundwater and surface water.

  13. Alternative Surfactants for Improved Efficiency of In Situ Tryptic Proteolysis of Fingermarks

    NASA Astrophysics Data System (ADS)

    Patel, Ekta; Clench, Malcolm R.; West, Andy; Marshall, Peter S.; Marshall, Nathan; Francese, Simona

    2015-06-01

    Despite recent improvements to in situ proteolysis strategies, a higher efficiency is still needed to increase both the number of peptides detected and the associated ion intensity, leading to a complete and reliable set of biomarkers for diagnostic or prognostic purposes. In the study presented here, an extract of a systematic study is illustrated investigating a range of surfactants assisting trypsin proteolytic activity. Method development was trialled on fingermarks; this specimen results from a transfer of sweat from an individual's fingertip to a surface upon contact. As sweat carries a plethora of biomolecules, including peptides and proteins, fingermarks are, potentially, a very valuable specimen for non-invasive prognostic or diagnostic screening. A recent study has demonstrated the opportunity to quickly detect peptides and small proteins in fingermarks using Matrix Assisted Laser Desorption Ionization Mass Spectrometry Profiling (MALDI MSP). However, intact detection bears low sensitivity and does not allow species identification; therefore, a shotgun proteomic approach was employed involving in situ proteolysis. Data demonstrate that in fingermarks, further improvements to the existing method can be achieved using MEGA-8 as surfactant in higher percentages as well as combinations of different detergents. Also, for the first time, Rapigest SF, normally used in solution digestions, has been shown to successfully work also for in situ proteolysis.

  14. Dereplicating and Spatial Mapping of Secondary Metabolites from Fungal Cultures in Situ

    PubMed Central

    2015-01-01

    Ambient ionization mass spectrometry techniques have recently become prevalent in natural product research due to their ability to examine secondary metabolites in situ. These techniques retain invaluable spatial and temporal details that are lost through traditional extraction processes. However, most ambient ionization techniques do not collect mutually supportive data, such as chromatographic retention times and/or UV/vis spectra, and this can limit the ability to identify certain metabolites, such as differentiating isomers. To overcome this, the dropletliquid microjunctionsurface sampling probe (dropletLMJSSP) was coupled with UPLCPDAHRMSMS/MS, thus providing separation, retention times, MS data, and UV/vis data used in traditional dereplication protocols. By capturing these mutually supportive data, the identity of secondary metabolites can be confidently and rapidly assigned in situ. Using the dropletLMJSSP, a protocol was constructed to analyze the secondary metabolite profile of fungal cultures without any sample preparation. The results demonstrate that fungal cultures can be dereplicated from the Petri dish, thus identifying secondary metabolites, including isomers, and confirming them against reference standards. Furthermore, heat maps, similar to mass spectrometry imaging, can be used to ascertain the location and relative concentration of secondary metabolites directly on the surface and/or surroundings of a fungal culture. PMID:26192135

  15. Dereplicating and Spatial Mapping of Secondary Metabolites from Fungal Cultures in Situ.

    PubMed

    Sica, Vincent P; Raja, Huzefa A; El-Elimat, Tamam; Kertesz, Vilmos; Van Berkel, Gary J; Pearce, Cedric J; Oberlies, Nicholas H

    2015-08-28

    Ambient ionization mass spectrometry techniques have recently become prevalent in natural product research due to their ability to examine secondary metabolites in situ. These techniques retain invaluable spatial and temporal details that are lost through traditional extraction processes. However, most ambient ionization techniques do not collect mutually supportive data, such as chromatographic retention times and/or UV/vis spectra, and this can limit the ability to identify certain metabolites, such as differentiating isomers. To overcome this, the droplet-liquid microjunction-surface sampling probe (droplet-LMJ-SSP) was coupled with UPLC-PDA-HRMS-MS/MS, thus providing separation, retention times, MS data, and UV/vis data used in traditional dereplication protocols. By capturing these mutually supportive data, the identity of secondary metabolites can be confidently and rapidly assigned in situ. Using the droplet-LMJ-SSP, a protocol was constructed to analyze the secondary metabolite profile of fungal cultures without any sample preparation. The results demonstrate that fungal cultures can be dereplicated from the Petri dish, thus identifying secondary metabolites, including isomers, and confirming them against reference standards. Furthermore, heat maps, similar to mass spectrometry imaging, can be used to ascertain the location and relative concentration of secondary metabolites directly on the surface and/or surroundings of a fungal culture. PMID:26192135

  16. In Situ Hydrocarbon Degradation by Indigenous Nearshore Bacterial Populations

    SciTech Connect

    Cherrier, J.

    2005-05-16

    Potential episodic hydrocarbon inputs associated with oil mining and transportation together with chronic introduction of hydrocarbons via urban runoff into the relatively pristine coastal Florida waters poses a significant threat to Florida's fragile marine environment. It is therefore important to understand the extent to which indigenous bacterial populations are able to degrade hydrocarbon compounds and also determine factors that could potentially control and promote the rate at which these compounds are broken down in situ. Previous controlled laboratory experiments carried out by our research group demonstrated that separately both photo-oxidation and cometabolism stimulate bacterial hydrocarbon degradation by natural bacterial assemblages collected from a chronically petroleum contaminated site in Bayboro Bay, Florida. Additionally, we also demonstrated that stable carbon and radiocarbon abundances of respired CO{sub 2} could be used to trace in situ hydrocarbon degradation by indigenous bacterial populations at this same site. This current proposal had two main objectives: (a) to evaluate the cumulative impact of cometabolism and photo-oxidation on hydrocarbon degradation by natural bacterial assemblages collected the same site in Bayboro Bay, Florida and (b) to determine if in situ hydrocarbon degradation by indigenous bacterial populations this site could be traced using natural radiocarbon and stable carbon abundances of assimilated bacterial carbon. Funds were used for 2 years of full support for one ESI Ph.D. student, April Croxton. To address our first objective a series of closed system bacterial incubations were carried out using photo-oxidized petroleum and pinfish (i.e. cometabolite). Bacterial production of CO{sub 2} was used as the indicator of hydrocarbon degradation and {delta}{sup 13}C analysis of the resultant CO{sub 2} was used to evaluate the source of the respired CO{sub 2} (i.e. petroleum hydrocarbons or the pinfish cometabolite). Results from these time series experiments demonstrated that short-term exposure of petroleum to UV light enhanced hydrocarbon degradation by 48% over that observed for non-photo-oxidized petroleum. Despite the greater bio-availability of the photo-oxidized over the non-photo-oxidized petroleum, an initial lag in CO{sub 2} production was observed indicating potential phototoxicity of the photo- by-products. {delta}{sup 13}C analysis and mass balance calculations reveal that co-metabolism with pinfish resulted in increased hydrocarbon degradation for both photo-oxidized and non-photo-oxidized petroleum each by over 100%. These results demonstrate the cumulative effect of photo-oxidation and co-metabolism on petroleum hydrocarbon degradation by natural bacterial populations indigenous to systems chronically impacted by hydrocarbon input. To address the second objective of this proposal bacterial concentrates were collected from Bayboro Harbor in April 2001 for nucleic acid extraction and subsequent natural radiocarbon abundance analyses. Unfortunately, however, all of these samples were lost due to a faulty compressor in our -70 freezer. The freezer was subsequently repaired and samples were again collected from Bayboro Harbor in June 2002 and again December 2002. Several attempts were made to extract the nucleic acid samples--however, the student was not able to successfully extract and an adequate amount of uncontaminated nucleic acid samples for subsequent natural radiocarbon abundance measurements of the bacterial carbon by accelerator mass spectrometry (i.e. require at least 50 {micro}g carbon for AMS measurement). Consequently, we were not able to address the second objective of this proposed work.

  17. In-situ Resources In Space

    NASA Technical Reports Server (NTRS)

    Curreri, Peter A.

    2005-01-01

    This tutorial is a primer on the motivational and materials science basis for utilizing space resources to lower the cost and increase the safety and reliability of human systems beyond Earth's orbit. Past research in materials processing in orbit will be briefly reviewed to emphasize the challenges and advantages inherent in processing materials in space. Data on resource availability from human Lunar and robotic/sensor missions beyond the Moon will be overviewed for resource relevance to human exploration and development of space. Specific scenarios such as propellant production on the Moon and Mars, and lunar photovoltaic power production from in-situ materials will be discussed in relation to exploration and commercialization of space. A conclusion will cover some of the visionary proposals for the use of space resources to extend human society and prosperity beyond Earth.

  18. IN SITU URANIUM STABILIZATION BY MICROBIAL METABOLITES

    SciTech Connect

    Turick, C; Anna Knox, A; Chad L Leverette,C; Yianne Kritzas, Y

    2006-11-29

    Soil contaminated with U was the focus of this study in order to develop in-situ, U bio-immobilization technology. We have demonstrated microbial production of a metal chelating biopolymer, pyomelanin, in U contaminated soil from the Tims Branch area of the Department of Energy (DOE) Savannah River Site (SRS) as a result of tyrosine amendments. Bacterial densities of pyomelanin producers were >106 cells/g wet soil. Pyomelanin demonstrated U chelating and mineral binding capacities at pH 4 and 7. In laboratory studies, in the presence of goethite or illite, pyomelanin enhanced U sequestration by these minerals. Tyrosine amended soils in field tests demonstrated increased U sequestration capacity following pyomelanin production up to 13 months after tyrosine treatments.

  19. Recent advances in in situ vitrification

    SciTech Connect

    Bonner, W.F.; Luey, Ja-Kael

    1992-05-01

    In Situ Vitrification (ISV) is an innovative mobile remediation technology for soils and other underground contamination: Developed by the US Department of Energy`s Pacific Northwest Laboratory (PNL), ISV has advanced during the past decade from a laboratory concept to a remediation technology commercially available for contaminated soils. ISV technology is currently being developed for remediation of DOE waste sites at Hanford, Oak Ridge National Laboratory (ORNL) Idaho National Laboratory (INEL), and other sites. The incentives for application of ISV can convert contaminated sites to a solid, highly durable block similar to naturally occurring obsidian. The ISV product has been shown capable of passing US Environmental Protection Agency (EPA) tests such as the Toxic Characteristic Leach Procedure (TCLP). Retrieval, handling and transport of untreated hazardous material would normally not be required after application of ISV. Therefore, costs, exposure to personnel, risk of releases to the environment, and generation of secondary wastes are greatly reduced compared with remove-and-treat technologies.

  20. Recent advances in in situ vitrification

    SciTech Connect

    Bonner, W.F.; Luey, Ja-Kael.

    1992-05-01

    In Situ Vitrification (ISV) is an innovative mobile remediation technology for soils and other underground contamination: Developed by the US Department of Energy's Pacific Northwest Laboratory (PNL), ISV has advanced during the past decade from a laboratory concept to a remediation technology commercially available for contaminated soils. ISV technology is currently being developed for remediation of DOE waste sites at Hanford, Oak Ridge National Laboratory (ORNL) Idaho National Laboratory (INEL), and other sites. The incentives for application of ISV can convert contaminated sites to a solid, highly durable block similar to naturally occurring obsidian. The ISV product has been shown capable of passing US Environmental Protection Agency (EPA) tests such as the Toxic Characteristic Leach Procedure (TCLP). Retrieval, handling and transport of untreated hazardous material would normally not be required after application of ISV. Therefore, costs, exposure to personnel, risk of releases to the environment, and generation of secondary wastes are greatly reduced compared with remove-and-treat technologies.

  1. Condition of in situ unexploded ordnance.

    PubMed

    Taylor, Susan; Bigl, Susan; Packer, Bonnie

    2015-02-01

    Unexploded ordnance (UXO) become point contamination sources when their casings fail and their explosive fill dissolve. To determine the modes of failure, we documented the condition of UXO found on military training ranges and sampled soils for explosives beneath 42 in situ UXO. We found that oxidation caused the metal UXO casings to swell and fail catastrophically. Unlike previous work, pitting of the metal casings was not found to be an important release route for explosives. Of the 42 UXO sampled, eight were leaking explosives into the soil and of these, four had perforated or cracked casings, three were corroded and one was a partially detonated round. We estimated a surface density of 74 UXO per hectare for a subset of UXO sampled. We used the relative concentrations of explosives and their transformation products in the soil to determine if the explosives had recently dissolved or were from past military training. PMID:25461079

  2. Mars in Situ Resource Utilization Technology Evaluation

    NASA Technical Reports Server (NTRS)

    Muscatello, Anthony C.; Santago-Maldonado, Edgardo

    2012-01-01

    We have examined the technologies required to enable Mars In-Situ Resource Utilization (ISRU) because our understanding of Mars resources has changed significantly in the last five years as a result of recent robotic missions to the red planet. Two major developments, (1) confirmation of the presence of near-surface water in the form of ice in very large amounts at high latitudes by the Phoenix Lander and (2) the likely existence of water at lower latitudes in the form of hydrates or ice in the top one meter of the regolith, have the potential to change ISRU technology selection. A brief technology assessment was performed for the most promising Mars atmospheric gas processing techniques: Reverse Water Gas Shift (RWGS) and Methanation (aka Sabatier), as well as an overview of soil processing technology to extract water from Martian soil.

  3. Remote versus in situ turbulence measurements

    NASA Technical Reports Server (NTRS)

    Frost, Walter

    1987-01-01

    Comparisons of in situ wind and turbulence measurements made with the NASA B-57 instrumented aircraft and those remotely made with both radar and lidar systems are presented. Turbulence measurements with a lidar or radar system as compared with those from an aircraft are the principal themes. However, some discussion of mean wind speed and direction measurements is presented. First, the principle of measuring turbulence with Doppler lidar and radar is briefly and conceptually described. The comparisons with aircraft measurements are then discussed. Two studies in particular are addressed: one uses the JAWS Doppler radar data and the other uses data gathered both with the NASA Marshall Space Flight Center and the the NOAA Wave Propagation Lab. gound based lidars. Finally, some conclusions and recommendations are made.

  4. Well bore breakouts and in situ stress

    SciTech Connect

    Zoback, M.D.; Moos, D.; Mastin, L.; Anderson, R.N.

    1985-06-10

    The detailed cross-sectional shape of stress induced well bore breakouts has been studied using specially processed ultrasonic borehole televiewer data. We show breakout shapes for a variety of rock types and introduce a simple elastic failure model which explains many features of the observations. Both the observations and calculations indicate that the breakouts define relatively broad and flat curvilinear surfaces which enlarge the borehole in the direction of minimum horizontal compression. This work supports the hypothesis that breakouts result from shear failure of the rock where the compressive stress concentration around the well bore is greatest and that breakouts can be used to determine the orientation of the horizontal principal stresses in situ.

  5. In situ PEM fuel cell water measurements

    SciTech Connect

    Borup, Rodney L; Mukundan, Rangachary; Davey, John R; Spendalow, Jacob S

    2008-01-01

    Efficient PEM fuel cell performance requires effective water management. The materials used, their durability, and the operating conditions under which fuel cells run, make efficient water management within a practical fuel cell system a primary challenge in developing commercially viable systems. We present experimental measurements of water content within operating fuel cells. in response to operational conditions, including transients and freezing conditions. To help understand the effect of components and operations, we examine water transport in operating fuel cells, measure the fuel cell water in situ and model the water transport within the fuel cell. High Frequency Resistance (HFR), AC Impedance and Neutron imaging (using NIST's facilities) were used to measure water content in operating fuel cells with various conditions, including current density, relative humidity, inlet flows, flow orientation and variable GDL properties. Ice formation in freezing cells was also monitored both during operation and shut-down conditions.

  6. In situ soil remediation: Bacteria or fungi?

    SciTech Connect

    Cutright, T.J.; Lee, S.

    1995-07-01

    Contamination of the environment is not a new problem. For most of recorded history, the unwanted byproducts of industrial and residential processes have been dumped into unlined pits or nearby streams. Although disposal techniques have greatly improved, significant quantities of hazardous materials are still being released to the environment via accidental spills and leaking underground storage tanks. One particular group of contaminants of critical environmental concern is polycyclic aromatic hydrocarbons (PAHs). PAH-contaminated sites typically cover large areas; therefore, the development of in situ remediation techniques such as bioremediation is strongly emphasized. In situations when inherent microorganisms are not capable of degrading the contaminants, foreign strains must be used. Bioremediation experiments were conducted to compare the remediation efficiencies of a bacteria and a fungus for an industrially PAH contaminated soil. Specifically, the use of three supplemental nutrient solutions were investigated in conjunction with the bacteria Achromobacter sp. and fungus Cunninghamella echinulata var. elegans.

  7. Support Routines for In Situ Image Processing

    NASA Technical Reports Server (NTRS)

    Deen, Robert G.; Pariser, Oleg; Yeates, Matthew C.; Lee, Hyun H.; Lorre, Jean

    2013-01-01

    This software consists of a set of application programs that support ground-based image processing for in situ missions. These programs represent a collection of utility routines that perform miscellaneous functions in the context of the ground data system. Each one fulfills some specific need as determined via operational experience. The most unique aspect to these programs is that they are integrated into the large, in situ image processing system via the PIG (Planetary Image Geometry) library. They work directly with space in situ data, understanding the appropriate image meta-data fields and updating them properly. The programs themselves are completely multimission; all mission dependencies are handled by PIG. This suite of programs consists of: (1)marscahv: Generates a linearized, epi-polar aligned image given a stereo pair of images. These images are optimized for 1-D stereo correlations, (2) marscheckcm: Compares the camera model in an image label with one derived via kinematics modeling on the ground, (3) marschkovl: Checks the overlaps between a list of images in order to determine which might be stereo pairs. This is useful for non-traditional stereo images like long-baseline or those from an articulating arm camera, (4) marscoordtrans: Translates mosaic coordinates from one form into another, (5) marsdispcompare: Checks a Left Right stereo disparity image against a Right Left disparity image to ensure they are consistent with each other, (6) marsdispwarp: Takes one image of a stereo pair and warps it through a disparity map to create a synthetic opposite- eye image. For example, a right eye image could be transformed to look like it was taken from the left eye via this program, (7) marsfidfinder: Finds fiducial markers in an image by projecting their approximate location and then using correlation to locate the markers to subpixel accuracy. These fiducial markets are small targets attached to the spacecraft surface. This helps verify, or improve, the pointing of in situ cameras, (8) marsinvrange: Inverse of marsrange . given a range file, re-computes an XYZ file that closely matches the original. . marsproj: Projects an XYZ coordinate through the camera model, and reports the line/sample coordinates of the point in the image, (9) marsprojfid: Given the output of marsfidfinder, projects the XYZ locations and compares them to the found locations, creating a report showing the fiducial errors in each image. marsrad: Radiometrically corrects an image, (10) marsrelabel: Updates coordinate system or camera model labels in an image, (11) marstiexyz: Given a stereo pair, allows the user to interactively pick a point in each image and reports the XYZ value corresponding to that pair of locations. marsunmosaic: Extracts a single frame from a mosaic, which will be created such that it could have been an input to the original mosaic. Useful for creating simulated input frames using different camera models than the original mosaic used, and (12) merinverter: Uses an inverse lookup table to convert 8-bit telemetered data to its 12-bit original form. Can be used in other missions despite the name.

  8. High resolution in situ ultrasonic corrosion monitor

    DOEpatents

    Grossman, R.J.

    1984-01-10

    An ultrasonic corrosion monitor is provided which produces an in situ measurement of the amount of corrosion of a monitoring zone or zones of an elongate probe placed in the corrosive environment. A monitoring zone is preferably formed between the end of the probe and the junction of the zone with a lead-in portion of the probe. Ultrasonic pulses are applied to the probe and a determination made of the time interval between pulses reflected from the end of the probe and the junction referred to, both when the probe is uncorroded and while it is corroding. Corresponding electrical signals are produced and a value for the normalized transit time delay derived from these time interval measurements is used to calculate the amount of corrosion.

  9. High resolution in situ ultrasonic corrosion monitor

    DOEpatents

    Grossman, Robert J.

    1985-01-01

    An ultrasonic corrosion monitor is provided which produces an in situ measurement of the amount of corrosion of a monitoring zone or zones of an elongate probe placed in the corrosive environment. A monitoring zone is preferably formed between the end of the probe and the junction of the zone with a lead-in portion of the probe. Ultrasonic pulses are applied to the probe and a determination made of the time interval between pulses reflected from the end of the probe and the junction referred to, both when the probe is uncorroded and while it is corroding. Corresponding electrical signals are produced and a value for the normalized transit time delay derived from these time interval measurements is used to calculate the amount of corrosion.

  10. Autofluorescence correction for fluorescence in situ hybridization

    SciTech Connect

    Szoelloesi, J.; Balazs, M.; Waldman, F.C.

    1995-08-01

    Optimal sensitivity of fluorescence in situ hybridization (FISH) requires bright signals and low background fluorescence. Use of locus-specific probes is especially dependent on high sensitivity. Some tissue preparations show high autofluorescence, masking small or dim signals. We have developed a new method for subtracting autofluorescence from digital images on a pixel-by-pixel basis. It is based on the observation that fluorescent labels for FISH have narrower excitation and emission spectra than the chemical components responsible for autofluorescence. Our new approach uses calculation of the ratio of autofluorescence between multiple color images for correction of autofluorescence in each individual image. By subtracting autofluorescence components, we were able to enhance centromeric signals and make previously indistiguishable cosmid signals clearly visible. This image-processing approach to autofluorescence correction may widen the applicability of gene-specific probes in FISH analysis of tumor material. 15 refs., 3 fig., 1 tab.

  11. In-situ continuous water analyzing module

    DOEpatents

    Thompson, Cyril V.; Wise, Marcus B.

    1998-01-01

    An in-situ continuous liquid analyzing system for continuously analyzing volatile components contained in a water source comprises: a carrier gas supply, an extraction container and a mass spectrometer. The carrier gas supply continuously supplies the carrier gas to the extraction container and is mixed with a water sample that is continuously drawn into the extraction container. The carrier gas continuously extracts the volatile components out of the water sample. The water sample is returned to the water source after the volatile components are extracted from it. The extracted volatile components and the carrier gas are delivered continuously to the mass spectometer and the volatile components are continuously analyzed by the mass spectrometer.

  12. In-situ continuous water monitoring system

    DOEpatents

    Thompson, C.V.; Wise, M.B.

    1998-03-31

    An in-situ continuous liquid monitoring system for continuously analyzing volatile components contained in a water source comprises: a carrier gas supply, an extraction container and a mass spectrometer. The carrier gas supply continuously supplies the carrier gas to the extraction container and is mixed with a water sample that is continuously drawn into the extraction container by the flow of carrier gas into the liquid directing device. The carrier gas continuously extracts the volatile components out of the water sample. The water sample is returned to the water source after the volatile components are extracted from it. The extracted volatile components and the carrier gas are delivered continuously to the mass spectrometer and the volatile components are continuously analyzed by the mass spectrometer. 2 figs.

  13. In-situ continuous water monitoring system

    DOEpatents

    Thompson, Cyril V.; Wise, Marcus B.

    1998-01-01

    An in-situ continuous liquid monitoring system for continuously analyzing volatile components contained in a water source comprises: a carrier gas supply, an extraction container and a mass spectrometer. The carrier gas supply continuously supplies the carrier gas to the extraction container and is mixed with a water sample that is continuously drawn into the extraction container by the flow of carrier gas into the liquid directing device. The carrier gas continuously extracts the volatile components out of the water sample. The water sample is returned to the water source after the volatile components are extracted from it. The extracted volatile components and the carrier gas are delivered continuously to the mass spectrometer and the volatile components are continuously analyzed by the mass spectrometer.

  14. PERFORMANCE CONFIRMATION IN-SITU INSTRUMENTATION

    SciTech Connect

    N.T. Raczka

    2000-05-23

    The purpose of this document is to identify and analyze the types of in-situ instruments and methods that could be used in support of the data acquisition portion of the Performance Confirmation (PC) program at the potential nuclear waste repository at Yucca Mountain. The PC program will require geomechanical , geophysical, thermal, and hydrologic instrumentation of several kinds. This analysis is being prepared to document the technical issues associated with each type of measurement during the PC period. This analysis utilizes the ''Performance Confirmation Input Criteria'' (CRWMS M&O 1999a) as its starting point. The scope of this analysis is primarily on the period after the start of waste package emplacement and before permanent closure of the repository, a period lasting between 15 and 300 years after last package emplacement (Stroupe 2000, Attachment 1, p. 1). The primary objectives of this analysis are to: (1) Review the design criteria as presented in the ''Performance Confirmation Input Criteria'' (CRWMS M&O 1999a). The scope of this analysis will be limited to the instrumentation related to parameters that require continuous monitoring of the conditions underground. (2) Preliminary identification and listing of the data requirements and parameters as related to the current repository layout in support of PC monitoring. (3) Preliminary identification of methods and instrumentation for the acquisition of the required data. Although the ''Performance Confirmation Input Criteria'' (CRWMS M&O 1999a) defines a broad range of data that must be obtained from a variety of methods, the focus of this analysis is on instrumentation related to the performance of the rock mass and the formation of water in the repository environment, that is obtainable from in-situ observation, testing, and monitoring.

  15. In Situ Field Testing of Processes

    SciTech Connect

    J. Wang

    2001-12-14

    The purpose of this Analysis/Model Report (AMR) is to update and document the data and subsequent analyses from ambient field-testing activities performed in underground drifts of the Yucca Mountain Site Characterization Project (YMP). This revision updates data and analyses presented in the initial issue of this AMR. This AMR was developed in accordance with the ''Technical Work Plan for Unsaturated Zone (UZ) Flow and Transport Process Model Report'' and ''Technical Work Plan for UZ Flow, Transport, and Coupled Processes Process Model Report. These activities were performed to investigate in situ flow and transport processes. The evaluations provide the necessary framework to: (1) refine and confirm the conceptual model of matrix and fracture processes in the unsaturated zone (UZ) and (2) analyze the impact of excavation (including use of construction water and effect of ventilation) on the UZ flow and transport processes. This AMR is intended to support revisions to ''Conceptual and Numerical Models for UZ Flow and Transport'' and ''Unsaturated Zone Flow and Transport Model Process Model Report''. In general, the results discussed in this AMR are from studies conducted using a combination or a subset of the following three approaches: (1) air-injection tests, (2) liquid-release tests, and (3) moisture monitoring using in-drift sensors or in-borehole sensors, to evaluate the impact of excavation, ventilation, and construction-water usage on the surrounding rocks. The liquid-release tests and air-injection tests provide an evaluation of in situ fracture flow and the competing processes of matrix imbibition. Only the findings from testing and data not covered in the ''Seepage Calibration Model and Seepage Testing Data'' are analyzed in detail in the AMR.

  16. In situ exploration of large dynamic networks.

    PubMed

    Hadlak, Steffen; Schulz, Hans-Jrg; Schumann, Heidrun

    2011-12-01

    The analysis of large dynamic networks poses a challenge in many fields, ranging from large bot-nets to social networks. As dynamic networks exhibit different characteristics, e.g., being of sparse or dense structure, or having a continuous or discrete time line, a variety of visualization techniques have been specifically designed to handle these different aspects of network structure and time. This wide range of existing techniques is well justified, as rarely a single visualization is suitable to cover the entire visual analysis. Instead, visual representations are often switched in the course of the exploration of dynamic graphs as the focus of analysis shifts between the temporal and the structural aspects of the data. To support such a switching in a seamless and intuitive manner, we introduce the concept of in situ visualization--a novel strategy that tightly integrates existing visualization techniques for dynamic networks. It does so by allowing the user to interactively select in a base visualization a region for which a different visualization technique is then applied and embedded in the selection made. This permits to change the way a locally selected group of data items, such as nodes or time points, are shown--right in the place where they are positioned, thus supporting the user's overall mental map. Using this approach, a user can switch seamlessly between different visual representations to adapt a region of a base visualization to the specifics of the data within it or to the current analysis focus. This paper presents and discusses the in situ visualization strategy and its implications for dynamic graph visualization. Furthermore, it illustrates its usefulness by employing it for the visual exploration of dynamic networks from two different fields: model versioning and wireless mesh networks. PMID:22034354

  17. Vimentin is a dominant target of in situ humoral immunity in human lupus tubulointerstitial nephritis

    PubMed Central

    Kinloch, Andrew J; Chang, Anthony; Ko, Kichul; Dunand, Carole J Henry; Henderson, Scott; Maienschein-Cleine, Mark; Kaverina, Natalya; Rovin, Brad; Ferrer, Marlene Salgado; Wolfgeher, Don; Liarski, Vladimir; Haddon, D James; Utz, Paul J; Wilson, Patrick C; Clark, Marcus R

    2014-01-01

    Objective In lupus nephritis (LuN), severe tubulointerstitial inflammation (TII) predicts progression to renal failure. Severe TII is associated with tertiary lymphoid neogenesis and in situ antigen-driven clonal B cell selection. The autoantigen(s) driving in situ B-cell selection in TII are not known. This study aimed to identify the dominant driving autoantigen(s). Methods Single CD38+ or Ki-67+ B cells were laser captured from seven LuN diagnostic biopsies. Eighteen clonally expanded immunoglobulin heavy and light chain variable region pairs were cloned and expressed as monoclonal antibodies. Seven more antibodies were cloned from flow sorted CD38+ cells from an eighth biopsy. Antigen characterization was performed using a combination of confocal microscopy, ELISA, screening protoarrays, immunoprecipitation and mass spectrometry. Serum IgG titers to the dominant antigen were determined in 48 LuN and 35 non-nephritic lupus samples using purified antigen-coated arrays. Autoantigen expression was localized by immunohistochemistry and immunofluorescence on normal and LuN kidney. Results Eleven of 25 antibodies reacted with cytoplasmic structures, four reacted with nuclei, and none with dsDNA. Vimentin was the only autoantigen identified by both mass spectrometry and by protoarray. Ten of the 11 anti-cytoplasmic TII antibodies directly bound vimentin. Vimentin was highly expressed by tubulointerstitial inflammatory cells, and tested TII antibodies preferentially bound inflamed tubulointerstitium. Finally, high-titers of serum anti-vimentin antibodies were associated with severe TII (p = 0.0001). Conclusion Vimentin, an antigenic feature of inflammation, is a dominant autoantigen targeted in situ in LuN TII. This adaptive autoimmune response likely feeds forward to worsen TII and renal damage. PMID:25306868

  18. In-situ observations of oxidation and phase stability in cast nickel-based intermetallic alloys

    SciTech Connect

    Babu, Suresh S.; Specht, Eliot D; Santella, Michael L; Ice, Gene E; David, Stan A

    2006-01-01

    The effects of the as-cast microstructure on the oxidation characteristics of two Ni-Al-Cr alloys with either gamma or gamma' primary solidification were investigated with an in-situ, time-resolved X-ray diffraction (TRXRD) technique using synchrotron radiation. The measurements, carried out during rapid heating and cooling, showed that a segregated microstructure in these cast alloys leads to the preferential formation of zirconium oxide before the formation of aluminum oxides is detected. The oxidation leads to a change in the phase stability and to the modification of surface microstructures. Computational thermodynamic models were used to explain the preferential formation of oxides in the as-cast microstructure.

  19. Comparisons of Remote And In-situ CME Features

    NASA Astrophysics Data System (ADS)

    Reinard, Alysha; Mulligan, T.; Lynch, B.

    2011-05-01

    We present a comparison of remote and in-situ CME ejecta using data from the Ulysses and SOHO missions. Quadrature occurs when two spacecraft form a 90 degree angle with the Sun. Quadrature studies allow the comparison of visible features of limb CMEs and and in-situ ICME properties. We investigate several events, including so-called "cannibal" CMEs, and compare the relationship between CME morphology and in-situ structures such as magnetic field, composition, and plasma properties.

  20. DNA/DNA in situ hybridization with enzyme linked probes

    SciTech Connect

    Grillo, S.; Mosher, M.; Charles, P.; Henry, S.; Taub, F.

    1987-05-01

    A non-radioactive in situ nucleic acid hybridization method which requires no antibodies, haptens, avidin or biotin intermediateries is presented. Horseradish peroxidase (HRP) labeled nucleic acid probes are hybridized in situ for 2 hours or less, followed by brief washing of hybridized cells and the direct detection of in situ hybrids with diaminobenzidine (DAB). Application of this method to the detection of Human Papilloma Virus (HPV) in human cells is shown.