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1

Radioactivity measurements in the aquatic environment using in-situ and laboratory gamma-ray spectrometry.  

PubMed

The in-situ underwater gamma-ray spectrometry method is validated by inter-comparison with laboratory method. Deployments of the spectrometer KATERINA on a submarine spring and laboratory measurements of water samples with HPGe detector were performed. Efficiency calibrations, Monte Carlo simulations and the Minimum Detectable Activity (MDA) estimations were realized. MDAs varied from 0.19 to 10.4 (lab) and 0.05 to 0.35 (in-situ) Bq/L, while activity concentrations differed from 7% (for radon progenies) up to 10% (for (40)K), between the two methods. PMID:24103707

Eleftheriou, G; Tsabaris, C; Androulakaki, E G; Patiris, D L; Kokkoris, M; Kalfas, C A; Vlastou, R

2013-12-01

2

Application of in-situ gamma spectrometry in the remediation of radioactively contaminated soil  

SciTech Connect

The Fernald Environmental Management Project (FEMP) is a US Department of Energy site that is undergoing total remediation and closure. Most of the remediation effort entails massive excavation of soil for disposal, both offsite and onsite, at an engineered disposal facility. In-situ gamma spectrometry is routinely used to support soil excavation operations to accurately and quickly identify soil areas as being above or below regulatory remediation criteria. Two different in-situ gamma spectrometry systems are used. The first is a sodium iodide (NaI) detector mounted either on a tractor or a jogging stroller, depending on the terrain to be measured. The NaI system allows the collection of a gamma energy spectrum which can be analyzed to identify and quantify radioactive isotopes which are present within the detector`s viewing area. Each energy spectrum is tagged by location coordinates provided by an on-board global positioning system (GPS) to precisely locate elevated contamination areas. The second is a tripod-mounted, high purity germanium detector (HPGe) gamma spectrometry system that is functionally similar to the NaI system. The principal advantage of the HPGe is its superior resolution, which allows much more accurate identification and quantification of radionuclide contaminants in soils. In order to effectively utilize the data quality objective process with these systems, three quality assurance (QA) elements had to be performed.

Sutton, C.; Yesso, J.D.; Danahy, R.J.; Cox, T.

1999-06-01

3

Contribution of atmospherical radon to in-situ scintillation gamma spectrometry data.  

PubMed

In-situ gamma spectrometry can be used for monitoring and determining natural and man-made radionuclide concentrations in the environment. The low detection limit of potential contaminants depends on the natural background variations, including variations in the atmospheric concentrations of radon and its decay products. The scintillation spectrometer response for atmospheric radon was simulated by the Monte Carlo method, and the results were compared with the experimental measurements over large water surfaces. The contributions of atmospheric radon to the natural background were assessed. PMID:21129988

Kluso?, J; Thinová, L

2011-08-01

4

In situ gamma spectrometry of piping in a CANDU heat transport system -- Application during decontamination  

SciTech Connect

An in situ pipe gamma spectrometry technique was applied to determine the activity within piping during various stages of CANDU reactor decontaminations. Measurements were performed in general radiation fields up to {approximately}500 mR/h and required both the detector and the pipe being scanned to be appropriately shielded from other neighboring piping. Measured counts were interpreted using a pipe source efficiency calibration with due regard to its distance dependence. Cobalt-60 was the dominant radionuclide on the piping before the decontamination. Deposition of {sup 124}Sb occurred on out-core piping surfaces during the decontamination. The spectrometry measurements were supplemented with contact radiation field measurements, which were performed using survey detectors housed within specially designed pipe shields. Radiation fields estimated from measured radionuclide activities were compared with the measured radiation fields. On average, the ratio of measured to estimated fields was {approximately}72%. Reasons for this discrepancy are discussed.

Husain, A.; Breckenridge, C.E. [Ontario Hydro Technologies, Toronto, Ontario (Canada); Storey, D. [Ontario Hydro Nuclear, Toronto, Ontario (Canada)

1995-02-01

5

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

SciTech Connect

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.

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

2006-11-15

6

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

SciTech Connect

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.

Uyttenhove, J. [Univ. of Gent (Belgium); Pomme, S.; Hardenman, F. [Belgian Nuclear Research Centre, Boeretang (Belgium); Culot, J.P. [A.V. Nuclear, Brussels (Belgium)] [and others

1997-10-01

7

In situ gamma-spectrometry several years after deposition of radiocesium. Part I. Approximation of depth distributions by the Lorentz function.  

PubMed

Several years after the deposition of fallout-radiocesium, the maximal activity of this radionuclide will not remain at the soil surface but be found rather in deeper layers. In order to estimate the total radiocesium contamination of a large area and the resulting gamma-dose rate by in-situ spectrometry, it is necessary to approximate the vertical distribution of this radionuclide by an analytical function. Observations at ten undisturbed grassland soils and Bavaria, Germany, show that the resulting depth distributions can be approximated closely by a three-parameter Lorentz function. This function characterises the observed distributions in all three critical sections, i.e. the surface layer, the distribution around the maximal concentration, and the tail at greater depth. It is also shown that the observed total activity per unit area of the soil due to 137Cs agrees very well with the corresponding value obtained from the integrated Lorentz function. The two coefficients of the Lorentz function, which characterise the location (depth) and width of the maximum in the activity distribution, are shown to be correlated. In part II of this study, it will be shown how the parameters of the Lorentz function can also be obtained by in-situ gamma-ray spectrometry. As a result, it is possible to use in-situ gamma-ray spectrometry to obtain the total 137Cs activity per unit area also for sites where the vertical distribution of this radionuclide in the soil is no longer exponential. PMID:9008007

Hillmann, U; Schimmack, W; Jacob, P; Bunzl, K

1996-11-01

8

In situ gamma-spectrometry several years after deposition of radiocesium. II. Peak-to-valley method.  

PubMed

A new method is introduced for deriving radiocesium soil contaminations and kerma rates in air from in situ gamma-ray spectrometric measurements. The approach makes use of additional information about gamma-ray attenuation given by the peak-to-valley ratio, which is the ratio of the count rates for primary and forward scattered photons. In situ measurements are evaluated by comparing the experimental data with the results of Monte Carlo simulations of photon transport and detector response. The influence of photons emitted by natural radionuclides on the calculation of the peak-to-valley ratio is carefully analysed. The new method has been applied to several post-Chernobyl measurements and the results agreed well with those of soil sampling. PMID:10052678

Gering, F; Hillmann, U; Jacob, P; Fehrenbacher, G

1998-12-01

9

In-situ gamma spectrometry measurements of time-dependent Xenon-135 inventory in the TRIGA Mark II reactor Vienna  

E-print Network

In this work, it has been shown that the time dependent Xe-135 inventory in the TRIGA Mark II reactor in Vienna, Austria can be measured via gamma spectrometry even in the presence of strong background radiation. It is focussing on the measurement of (but not limited to) the nuclide Xe-135. The time dependent Xe-135 inventory of the TRIGA Mark II reactor Vienna has been measured using a temporary beam line between one fuel element of the core placed onto the thermal column after shutdown and a detector system located just above the water surface of the reactor tank. For the duration of one week, multiple gamma ray spectra were recorded automatically, starting each afternoon after reactor shutdown until the next morning. One measurement series has been recorded over the weekend. The Xe-135 peaks were extracted from a total of 1227 recorded spectra using an automated peak search algorithm and analyzed for their time-dependent properties. Although the background gamma radiation present in the core after shutdown...

Riede, Julia

2013-01-01

10

In-situ gamma spectrometry measurements of time-dependent Xenon-135 inventory in the TRIGA Mark II reactor Vienna  

E-print Network

In this work, it has been shown that the time dependent Xe-135 inventory in the TRIGA Mark II reactor in Vienna, Austria can be measured via gamma spectrometry even in the presence of strong background radiation. It is focussing on the measurement of (but not limited to) the nuclide Xe-135. The time dependent Xe-135 inventory of the TRIGA Mark II reactor Vienna has been measured using a temporary beam line between one fuel element of the core placed onto the thermal column after shutdown and a detector system located just above the water surface of the reactor tank. For the duration of one week, multiple gamma ray spectra were recorded automatically, starting each afternoon after reactor shutdown until the next morning. One measurement series has been recorded over the weekend. The Xe-135 peaks were extracted from a total of 1227 recorded spectra using an automated peak search algorithm and analyzed for their time-dependent properties. Although the background gamma radiation present in the core after shutdown was large especially in the lower energy range, the Xe-135 peak located at 249.8 keV could be extracted from the most spectra where present and could be compared to theoretical calculations.

Julia Riede; Helmuth Boeck

2013-07-29

11

Small Scale Assessment of Spatial and Vertical Redistribution of Fukushima Fallouts Radiocaesium in Contaminated Soil Using in-situ HPGe Gamma Ray Spectrometry  

NASA Astrophysics Data System (ADS)

After Tohoku earthquake on March 11th 2011, the subsequent tsunami and the resulting Fukushima Daiichi Nuclear Power Plant disaster, gamma emitting particles, first release into the atmosphere, were quickly deposited on the soil surface, with potentially harmful level in the surroundings of the nuclear power plant. Thus, the evaluation of soil deposition pattern, depth migration and afterward radionuclides redistribution and export by erosion and hydrological processes is fundamental for contamination assessments and to plan future actions. Our study site is located 37km from Fukushima power plant, inside the evacuated zone. In this study, we used a bounded erosion plot of 22.1m x 5m to assess global export of sediments and 137Cs. This plot, previously cropped with tobacco, is morphologically divided into inter-rill areas separated by rills that formed into former wheel tracks. The bottom of the plot is subject to deposition of sediments. In order to determine and quantify the internal processes responsible of the export of sediment, the depth distribution of 137Cs is estimated using a portable High Purity Germanium (HPGe) detector. Such a portable device, associated to the high radiation levels, allow an acquisition of spatially distributed data within the plot in a reasonable time (1 min/sample). At the same time, depth distribution of 137Cs are measured using the scrapper plate technique, adapted to obtain a fine resolution in the first, highly contaminated, centimeters of soil. Finally, 137Cs depth profiles, associated with in situ and laboratory gamma spectrums acquired with the portable detector, allow for the detector calibration. Although the initial deposit can reasonably be supposed homogeneous at the plot scale, the dataset obtained 3 months later shows high spatial and temporal variability due to erosion processes. Measurements with the portable HPGe detector proved to be useful at this small scale, avoiding the needs of a large number of soil samples, and our results are promising to understand erosion at larger scale where horizontal patterns of deposition and redistribution are usually supposed homogeneous over quite larger areas.

Patin, J.; Onda, Y.; Yoda, H.; Kato, H.

2011-12-01

12

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)

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.

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

2013-04-01

13

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

PubMed

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

Slaninka, Alojz; Slávik, Ondrej; Necas, Vladimír

2010-01-01

14

Continuous gamma-ray spectrometry in the Fast Flux Test Facility (FFTF)  

NASA Astrophysics Data System (ADS)

Gamma ray continua were measured at startup in the Fast Flux Test Facility (FFTF). A special FFTF insert, called the In-Reactor Thimble (IRT), provided an adequate environment for in situ operation of the gamma spectrometer. The IRT replaced a fuel assembly near core center (No. 2101) and measurements were conducted at three axial locations, namely midplane, the lower axial shield, and the upper axial reflector. Observations were carried out with Compton Recoil Gamma Ray Spectrometry at the state of the art. Advantage was thereby taken of the most recent advances, including extension of gamma ray spectrometry up to roughly 7 MeV with the new in situ Janus detector probe.

Gold, R.; Kaiser, B. J.; Moore, F. S., Jr.; Bunch, W. L.; McElroy, W. N.; Sheen, E. M.

1980-10-01

15

Airborne Gamma-Spectrometry in Switzerland  

SciTech Connect

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.

Butterweck, Gernot [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Bucher, Benno [Swiss Federal Nuclear Safety Inspectorate, 5232 Villigen HSK (Switzerland); Rybach, Ladislaus [Swiss Federal Institute of Technology Zurich, Institute of Geophysics, 8093 Zurich (Switzerland)

2008-08-07

16

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...

17

Mass spectrometry imaging for in situ kinetic histochemistry  

PubMed Central

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

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

2013-01-01

18

In situ determination of the grafting sites on nanosized ceramic powders by FT-IR spectrometry  

Microsoft Academic Search

The grafting of hexamethyldisilazane (HMDS) on the surface of alumina and titania nanosized powders has been followed in situ by Fourier transform infrared surface spectrometry. It is demonstrated that the reaction of HMDS with the different hydroxyl groups on the alumina and titania surfaces is selective and that Si-OH groups can be generated by oxidation of the grafted surfaces. Then

M.-I. Baraton; F. Chancel; L. Merhari

1997-01-01

19

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

SciTech Connect

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.

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

2012-04-30

20

In situ measurements of thermospheric composition, temperature, and winds by mass spectrometry  

NASA Technical Reports Server (NTRS)

Mass spectrometry, in which a beam of electrons ionizes a sample of atmospheric gas and then analyses the ions thus produced to determine the concentration of each species in the sample, is presently evaluated as a basis for the study of earth atmosphere and other planetary atmospheres' properties. Recent applications of in situ mass spectrometry have measured thermospheric neutral gas composition, temperatures, and winds, with a spatial resolution sufficiently high to reveal previously unsuspected atmospheric variability. It is expected that analyses of these data will lead to a more detailed understanding of the deposition processes governing the thermosphere's highly variable structure.

Spencer, N. W.; Carignan, G. R.

1988-01-01

21

Comparison of gamma-ray coincidence and low-background gamma-ray singles spectrometry.  

PubMed

Aerosol samples have been studied under different background conditions using gamma-ray coincidence and low-background gamma-ray singles spectrometric techniques with High-Purity Germanium detectors. Conventional low-background gamma-ray singles counting is a competitive technique when compared to the gamma-gamma coincidence approach in elevated background conditions. However, measurement of gamma-gamma coincidences can clearly make the identification of different nuclides more reliable and efficient than using singles spectrometry alone. The optimum solution would be a low-background counting station capable of both singles and gamma-gamma coincidence spectrometry. PMID:22037206

Konki, J; Greenlees, P T; Jakobsson, U; Jones, P; Julin, R; Juutinen, S; Ketelhut, S; Hauschild, K; Kontro, R; Leppänen, A-P; Lopez-Martens, A; Mattila, A; Nieminen, P; Nyman, M; Peräjärvi, K; Peura, P; Rahkila, P; Ruotsalainen, P; Sarén, J; Scholey, C; Sorri, J; Toivonen, H; Turunen, J; Uusitalo, J

2012-02-01

22

Quantification of cuttlefish (Sepia officinalis) camouflage: a study of color and luminance using in situ spectrometry.  

PubMed

Cephalopods are renowned for their ability to adaptively camouflage on diverse backgrounds. Sepia officinalis camouflage body patterns have been characterized spectrally in the laboratory but not in the field due to the challenges of dynamic natural light fields and the difficulty of using spectrophotometric instruments underwater. To assess cuttlefish color match in their natural habitats, we studied the spectral properties of S. officinalis and their backgrounds on the Aegean coast of Turkey using point-by-point in situ spectrometry. Fifteen spectrometry datasets were collected from seven cuttlefish; radiance spectra from animal body components and surrounding substrates were measured at depths shallower than 5 m. We quantified luminance and color contrast of cuttlefish components and background substrates in the eyes of hypothetical di- and trichromatic fish predators. Additionally, we converted radiance spectra to sRGB color space to simulate their in situ appearance to a human observer. Within the range of natural colors at our study site, cuttlefish closely matched the substrate spectra in a variety of body patterns. Theoretical calculations showed that this effect might be more pronounced at greater depths. We also showed that a non-biological method ("Spectral Angle Mapper"), commonly used for spectral shape similarity assessment in the field of remote sensing, shows moderate correlation to biological measures of color contrast. This performance is comparable to that of a traditional measure of spectral shape similarity, hue and chroma. This study is among the first to quantify color matching of camouflaged cuttlefish in the wild. PMID:23254307

Akkaynak, Derya; Allen, Justine J; Mäthger, Lydia M; Chiao, Chuan-Chin; Hanlon, Roger T

2013-03-01

23

Formation and in situ sizing of gamma-Fe2O3 nanoparticles in a microwave flow reactor.  

PubMed

Nanocrystalline gamma-Fe2O3 particles were produced in a microwave flow reactor. The reaction of iron pentacarbonyl [Fe(CO)5] with the plasma gases Ar/O2 to form nanosized particles was followed by in situ particle mass spectrometry. The particle mass spectrometer combines a nonintrusive sampling technique with a calibration-free mass determination. The influence of process parameters like microwave power, precursor concentration, and pressure on the particle size was studied. The results reveal a mean particle diameter in the range of 4-5 nm with a slight dependence on the process parameter. The geometric standard deviation of the measured size distribution was always between 1.1 and 1.2. PMID:12914055

Janzen, C; Wiggers, H; Knipping, J; Roth, P

2001-06-01

24

In situ measurement of refractive index changes induced by gamma radiation in germanosilicate fibers  

Microsoft Academic Search

We propose a technique to measure in situ the refractive index changes induced by ionizing radiation in single-mode optical fibers. This change can be derived from the channel drift appearing in narrow channel wavelength-division-multiplexing couplers exposed to gamma radiation. We measured a radiation-induced refractive index change of about 5 10-6\\/kGy[H2O] at low doses and 5 10-7\\/kGy[H2O] at higher doses. No

A. Fernandez Fernandez; B. Brichard; F. Berghmans

2003-01-01

25

Matrix-Assisted Laser Desorption Ionization Imaging Mass Spectrometry: In Situ Molecular Mapping  

PubMed Central

Matrix-assisted laser desorption ionization imaging mass spectrometry (IMS) is a relatively new imaging modality that allows mapping of a wide range of biomolecules within a thin tissue section. The technology uses a laser beam to directly desorb and ionize molecules from discrete locations on the tissue that are subsequently recorded in a mass spectrometer. IMS is distinguished by the ability to directly measure molecules in situ ranging from small metabolites to proteins, reporting hundreds to thousands of expression patterns from a single imaging experiment. This article reviews recent advances in IMS technology, applications, and experimental strategies that allow it to significantly aid in the discovery and understanding of molecular processes in biological and clinical samples. PMID:23259809

Angel, Peggi M.; Caprioli, Richard M.

2013-01-01

26

Combining in situ proteolysis and mass spectrometry to crystallize Escherichia coli PgaB  

PubMed Central

The periplasmic poly-?-1,6-N-acetyl-d-glucosamine (PNAG) de-N-acetylase PgaB from Escherichia coli was overexpressed and purified, but was recalcitrant to crystallization. Use of the in situ proteolysis technique produced crystals of PgaB, but these crystals could not be optimized for diffraction studies. By analyzing the initial crystal hits using SDS–PAGE and mass spectrometry, the boundaries of the protein species that crystallized were determined. The re-­engineered protein target crystallized reproducibly without the addition of protease and with significantly increased crystal quality. Crystals of the selenomethionine-incorporated protein exhibited the symmetry of space group P212121 and diffracted to 2.1?Å resolution. PMID:22750880

Little, Dustin J.; Whitney, John C.; Robinson, Howard; Yip, Patrick; Nitz, Mark; Howell, P. Lynne

2012-01-01

27

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

PubMed Central

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

Fujimura, Yoshinori; Miura, Daisuke

2014-01-01

28

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

PubMed

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

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

2014-03-01

29

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

NASA Technical Reports Server (NTRS)

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.

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

1988-01-01

30

In situ elemental analysis using neutron-capture gamma-ray spectroscopy  

NASA Astrophysics Data System (ADS)

In situ chemical analysis has become increasingly important in many areas of geochemical exploration and environmental monitoring. However, the determination of absolute or relative concentrations by neutron-gamma techniques can be difficult because of the variety of materials that can be encountered. Changes in concentration of neutron moderators, particularly water, and of strong absorbers, such as iron, can result in spatial and energy distribution variations of the neutron flux in the material. These lead to changes in the measured gamma-ray spectrum. We have been developing analytical procedures which allow the absolute and relative abundances of major and minor elements to be determined from the measured neutron-induced gamma-ray spectrum. Calculations are made using the one-dimensional neutron and gamma transport code ANISN. From the calculations, conversion factors are obtained that can be used to convert gamma-ray count rates to elemental concentrations. Once these conversion factors are determined as a function of water content and the macroscopic cross section, they can be used to determine compositions of unknown samples. To explore the application of these analytical methods, a number of different experimental test programs have been initiated to collect measured gamma-ray spectra. Field tests have been conducted in soils of various compositions using a 120 cm 3 HPGe detector and a 14 MeV pulsed neutron generator.

Evans, Larry G.; Lapides, Jeffrey R.; Trombka, Jacob I.; Jensen, Dal H.

31

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

USGS Publications Warehouse

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.

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

1983-01-01

32

Technical considerations for using in situ gamma spectroscopy in conducting final status surveys.  

PubMed

Facilities undergoing decommissioning are required to conduct radiological surveys to initially characterize contaminants, guide remediation activities, and demonstrate that cleanup criteria have been met, based on screening or site-specific derived concentration guideline levels. This paper presents a number of technical considerations, not all inclusive, associated with the use of in situ gamma spectroscopy that should be addressed when such a method is proposed for conducting final status surveys. The technical issues identified here do not yet reflect the policy of the NRC on this subject. PMID:12792406

Dehmel, Jean-Claude; Schneider, Stewart

2003-06-01

33

MALDI Imaging Mass Spectrometry for In Situ Proteomic Analysis of Preneoplastic Lesions in Pancreatic Cancer  

PubMed Central

The identification of new biomarkers for preneoplastic pancreatic lesions (PanINs, IPMNs) and early pancreatic ductal adenocarcinoma (PDAC) is crucial due to the diseasés high mortality rate upon late detection. To address this task we used the novel technique of matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) on genetically engineered mouse models (GEM) of pancreatic cancer. Various GEM were analyzed with MALDI IMS to investigate the peptide/protein-expression pattern of precursor lesions in comparison to normal pancreas and PDAC with cellular resolution. Statistical analysis revealed several discriminative m/z-species between normal and diseased tissue. Intraepithelial neoplasia (PanIN) and intraductal papillary mucinous neoplasm (IPMN) could be distinguished from normal pancreatic tissue and PDAC by 26 significant m/z-species. Among these m/z-species, we identified Albumin and Thymosin-beta 4 by liquid chromatography and tandem mass spectrometry (LC-MS/MS), which were further validated by immunohistochemistry, western blot, quantitative RT-PCR and ELISA in both murine and human tissue. Thymosin-beta 4 was found significantly increased in sera of mice with PanIN lesions. Upregulated PanIN expression of Albumin was accompanied by increased expression of liver-restricted genes suggesting a hepatic transdifferentiation program of preneoplastic cells. In conclusion we show that GEM of endogenous PDAC are a suitable model system for MALDI-IMS and subsequent LC-MS/MS analysis, allowing in situ analysis of small precursor lesions and identification of differentially expressed peptides and proteins. PMID:22761793

Grüner, Barbara M.; Hahne, Hannes; Mazur, Pawel K.; Trajkovic-Arsic, Marija; Maier, Stefan; Esposito, Irene; Kalideris, Evdokia; Michalski, Christoph W.; Kleeff, Jörg; Rauser, Sandra; Schmid, Roland M.; Küster, Bernhard; Walch, Axel; Siveke, Jens T.

2012-01-01

34

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

NASA Technical Reports Server (NTRS)

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.

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

35

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

NASA Technical Reports Server (NTRS)

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.

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

2005-01-01

36

MALDI-TOF mass spectrometry, an efficient technique for in situ detection and characterization of actinomycins.  

PubMed

An extensive study of actinomycins was performed using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS). Actinomycins represent a well-known family of peptidolactone chromopeptides with potent cytostatic and antibiotic properties. Using five well-characterized streptomycete strains, we introduced MALDI-TOF MS as an efficient technique for rapid in situ detection of actinomycins in surface extracts of cells picked from agar plates. By this procedure, actinomycin complexes can be investigated with high sensitivity and accuracy in a minimum of time. These studies were complemented by mass spectrometric investigation of actinomycins obtained from culture filtrate extracts and purified by high-performance liquid chromatography to detect yet unknown actinomycin species. By feeding experiments, C-demethyl-actinomycins from Streptomyces chrysomallus and Streptomyces parvulus as well as hemi-actinomycins from Streptomyces antibioticus lacking one of the two pentapeptide lactone rings were isolated and characterized as novel variants for structure-activity relationship studies. Structural characterization of the investigated actinomycins was performed by post source decay MALDI-TOF MS. The specific features of the fragmentation patterns of the protonated and cationized forms of selected actinomycins were investigated in detail. PMID:24619547

Vater, Joachim; Crnov?i?, Ivana; Semsary, Siamak; Keller, Ullrich

2014-03-01

37

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

NASA Technical Reports Server (NTRS)

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.

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

38

Time-resolved neutron/gamma-ray data acquisition for in situ subsurface planetary geochemistry  

NASA Astrophysics Data System (ADS)

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.

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

2013-04-01

39

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

SciTech Connect

'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.'

Buchanan, M.V.; Hurst, G.B.; Doktycz, M.J.; Britt, P.F.; Weaver, K. [Oak Ridge National Lab., TN (US); Lidstrom, M.; Costello, A. [Univ. of Washington, Seattle, WA (US)

1998-01-01

40

MCNPX evaluation of gamma spectrometry results in high radon concentration areas.  

PubMed

The radon concentration in underground workplaces may reach tens of thousands of Bq m(-3). A simple MCNPXTM Monte Carlo (MC) model of a cave was developed to estimate the influence of radon on the in situ gamma spectrometry results in various geometries and radon concentrations. The detector total count rate was obtained as the sum of the individual count rates due to 214Bi in the air, radon in the walls and deposition of radon daughters on surfaces. The MC model was then modified and used in the natural conditions of the Mlade? Caves, Czech Republic. The content of 226Ra was calculated from laboratory gamma spectrometry measurements, and the concentrations of unattached and attached 214Bi were measured using the FRITRA4 device (SMM-Prague). We present a comparison of the experimental results with results calculated by the MCNPXTM model of the Gamma Surveyor spectrometry probe (GF Instruments) with a 3?×3? NaI(Tl) detector and a 2?×2? BGO detector. PMID:24729561

Thinová, L; Solc, J

2014-07-01

41

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

Microsoft Academic Search

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

Rui Feng; Rui

1994-01-01

42

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

NASA Astrophysics Data System (ADS)

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 ?), 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.

Matusiewicz, Henryk; Krawczyk, Magdalena

2007-03-01

43

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

NASA Technical Reports Server (NTRS)

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.

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

1972-01-01

44

Further development of IDGS: Isotope dilution gamma-ray spectrometry  

NASA Astrophysics Data System (ADS)

The isotope dilution gamma-ray spectrometry (IDGS) technique for determining the plutonium concentration and isotopic composition of highly radioactive spent-fuel dissolver solutions has been further developed. Both the sample preparation and the analysis have been improved. The plutonium isotopic analysis is based on high-resolution, low-energy gamma-ray spectrometry. The plutonium concentration in the dissolver solutions then is calculated from the measured isotopic differences among the spike, the dissolver solution, and the spiked dissolver solution. Plutonium concentrations and isotopic compositions of dissolver solutions analyzed from this study agree well with those obtained by traditional isotope dilution mass spectrometry (IDMS) and are consistent with the first IDGS experimental result. With the current detector efficiency, sample size, and a 100-min count time, the estimated precision is approximately 0.5 percent for Pu-239 and Pu-240 isotopic analyses and approximately 1 percent for the plutonium concentration analysis.

Li, T. K.; Parker, J. L.; Kuno, Y.; Sato, S.; Kamata, M.; Akiyama, T.

45

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

USGS Publications Warehouse

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.

Day, J.H., Jr.

1985-01-01

46

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

PubMed

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 CO2) 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

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

2014-11-01

47

Imaging Neutron Activation Analysis and Multiplexed Gamma Ray Spectrometry.  

NASA Astrophysics Data System (ADS)

This work demonstrates for the first time the feasibility of Imaging Neutron Activation Analysis (Imaging NAA) and of multiplexed gamma-ray spectrometry. The two techniques are based on position sensitive beta -gamma coincidence measurement using a gamma-ray detector, a charged particle imaging detector and a coincidence system. Imaging NAA is a technique for determining the 2-dimensional elemental distributions in heterogeneous samples. With multiplexed gamma-ray spectrometry it is possible to count an array of samples simultaneously which results in a substantial reduction in total counting time and also low background because of the coincidence measurement. Two distinctly different charged particle imaging detectors were investigated for electron localization. They were: (1) an electron optics based system for low energy secondary electron imaging and (2) a Position Sensitive Photomultiplier Tube (PSPMT) coupled to a thin plastic scintillator for beta imaging. The secondary electron imaging system offers a spatial resolution of 30 ?m but its active imaging area is only 1 mm in diameter, and the beta detection efficiency is less than 10%. The PSPMT gives a spatial resolution of 2.5 mm FWHM with a 60 x 55 mm^2 active area and a beta detection efficiency of up to 36%. The secondary electron imaging system is suitable for element mapping of small continuous heterogeneous samples, while the PSPMT is suitable for multiplexed gamma-ray spectrometry of discrete samples. Results show that using the PSPMT it is possible to multiplex 100 samples, which results in up to a factor of 36 gain in total counting time compared to counting the samples individually. Experimental results that demonstrate the two techniques are presented for various radionuclides that undergo beta, alpha or EC decay followed by coincident gamma -ray emission.

Dewaraja, Yuni Kamalika

48

In Situ Mass Spectrometry Imaging and Ex Vivo Characterization of Renal Crystalline Deposits Induced in Multiple Preclinical Drug Toxicology Studies  

PubMed Central

Drug toxicity observed in animal studies during drug development accounts for the discontinuation of many drug candidates, with the kidney being a major site of tissue damage. Extensive investigations are often required to reveal the mechanisms underlying such toxicological events and in the case of crystalline deposits the chemical composition can be problematic to determine. In the present study, we have used mass spectrometry imaging combined with a set of advanced analytical techniques to characterize such crystalline deposits in situ. Two potential microsomal prostaglandin E synthase 1 inhibitors, with similar chemical structure, were administered to rats over a seven day period. This resulted in kidney damage with marked tubular degeneration/regeneration and crystal deposits within the tissue that was detected by histopathology. Results from direct tissue section analysis by matrix-assisted laser desorption ionization mass spectrometry imaging were combined with data obtained following manual crystal dissection analyzed by liquid chromatography mass spectrometry and nuclear magnetic resonance spectroscopy. The chemical composition of the crystal deposits was successfully identified as a common metabolite, bisulphonamide, of the two drug candidates. In addition, an un-targeted analysis revealed molecular changes in the kidney that were specifically associated with the area of the tissue defined as pathologically damaged. In the presented study, we show the usefulness of combining mass spectrometry imaging with an array of powerful analytical tools to solve complex toxicological problems occurring during drug development. PMID:23110069

Bjurstrom, Sivert; Goodwin, Richard J. A.; Basmaci, Elisa; Gustafsson, Ingela; Annas, Anita; Hellgren, Dennis; Svanhagen, Alexander; Andren, Per E.; Lindberg, Johan

2012-01-01

49

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

PubMed

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

Osvath, I; Povinec, P P

2001-01-01

50

Automated gamma spectrometry and data analysis on radiometric neutron dosimeters  

Microsoft Academic Search

An automated gamma-ray spectrometry system was designed and implemented by the Westinghouse Hanford Company at the Hanford Engineering Development Laboratory (HEDL) to analyze radiometric neutron dosimeters. Unattended, automatic, 24 hour\\/day, 7 day\\/week operation with online data analysis and mainframe-computer compatible magnetic tape output are system features. The system was used to analyze most of the 4000-plus radiometric monitors (RM's) from

1983-01-01

51

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

NASA Astrophysics Data System (ADS)

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.

Al-Ghamdi, Abdulrahman S.

52

In situ hafnium isotope ratio analysis of zircon by inductively coupled plasma multiple collector mass spectrometry  

Microsoft Academic Search

Hf isotopic data are reported for ten ?0.01-mm2 subareas of a zircon crystal separated from the ? 318-Ma diatreme of Elie Ness, Fife, Scotland. In situ analysis was achieved by ablation sampling with a Nd:YAG laser into an inductively-coupled plasma, with ions dispersed by a sector magnet and integrated in a 7-Faraday multicollector array. Despite large interferences from Yb (16%

Matthew F. Thirlwall; Andrew J. Walder

1995-01-01

53

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

SciTech Connect

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.

Ken Telschow; Rob Schley; Dave Cottle

2006-05-01

54

The comparative effects of gamma radiation and in situ alpha particles on five strong-base anion exchange resins  

SciTech Connect

The effects of external gamma radiation and in situ alpha particles were measured on a recently available, macroporous, strong-base polyvinylpyridine resin and on four strong-base polystyrene anion exchange resins. Each resin was irradiated in 7 M nitric acid to 1--10 megaGray of gamma radiation from external {sup 60}Co, or to 5--14 megaGray of alpha particles from sorbed {sup 238}Pu. Each irradiated resin was measured for changes in dry weight, wet volume, weak-base and strong-base chloride exchange capacities, and exchange capacities for Pu(4) from nitric acid. Alpha-induced resin damage was significantly less than that caused by an equivalent dose of gamma radiation. The polyvinylpyridine resin offers the greatest resistance to damage from gamma radiation and from alpha particles. 5 refs., 1 figs. 5 tabs.

Marsh, S.F.

1991-01-01

55

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

NASA Technical Reports Server (NTRS)

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.

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

2011-01-01

56

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

SciTech Connect

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.

Gavrilov, Boris [Institute of Cytology, Russian Academy of Sciences, 194064 St. Petersburg (Russian Federation); Vezhenkova, Irina [Institute of Cytology, Russian Academy of Sciences, 194064 St. Petersburg (Russian Federation); Firsanov, Denis [Institute of Cytology, Russian Academy of Sciences, 194064 St. Petersburg (Russian Federation); Solovjeva, Liudmila [Institute of Cytology, Russian Academy of Sciences, 194064 St. Petersburg (Russian Federation); Svetlova, Maria [Institute of Cytology, Russian Academy of Sciences, 194064 St. Petersburg (Russian Federation); Mikhailov, Vyacheslav [Institute of Cytology, Russian Academy of Sciences, 194064 St. Petersburg (Russian Federation); Tomilin, Nikolai [Institute of Cytology, Russian Academy of Sciences, 194064 St. Petersburg (Russian Federation)]. E-mail: nvtom@hotmail.com

2006-09-08

57

Airborne gamma spectrometry--towards integration of European operational capability.  

PubMed

Airborne gamma spectrometry is an excellent tool for finding out in a timely manner the extent and magnitude of the dispersion of radioactive materials resulting from a nuclear disaster. To utilise existing European airborne monitoring capabilities for multilateral assistance in an accident is a complex administrative and technical matter. Several international exercises have been organised demonstrating the capability to cooperate. However, efficient mutual assistance between European countries requires conceptual work, standards and harmonisation of software. A unified radiological vocabulary and data exchange format in XML need to be developed. A comprehensive database is essential for data assimilation. An operations centre is needed for management and planning of surveys. PMID:15238672

Toivonen, Harri

2004-01-01

58

Basic characterization of highly enriched uranium by gamma spectrometry  

E-print Network

Gamma-spectrometric methods suitable for the characterization of highly enriched uranium samples encountered in illicit trafficking of nuclear materials are presented. In particular, procedures for determining the 234U, 235U, 238U, 232U and 236U contents and the age of highly enriched uranium are described. Consequently, the total uranium content and isotopic composition can be calculated. For determining the 238U and 232U contents a low background chamber was used. In addition, age dating of uranium was also performed using low-background spectrometry.

Cong Tam Nguyen; Jozsef Zsigrai

2005-08-25

59

In situ atom trapping of Bi on W-coated slotted quartz tube flame atomic absorption spectrometry and interference studies  

NASA Astrophysics Data System (ADS)

Analytical performances of metal coated slotted quartz tube flame atomic absorption spectrometry (SQT-FAAS) and slotted quartz tube in situ atom trapping flame atomic absorption spectrometry (SQT-AT-FAAS) systems were evaluated for determination of Bi. Non-volatile elements such as Mo, Zr, W and Ta were tried as coating materials. It was observed that W-coated SQT gave the best sensitivity for the determination of Bi for SQT-FAAS and SQT-AT-FAAS. The parameters for W-coated SQT-FAAS and W-coated SQT-AT-FAAS were optimized. Sensitivity of FAAS for Bi was improved as 4.0 fold by W-coated SQT-FAAS while 613 fold enhancement in sensitivity was achieved by W-coated SQT-AT-FAAS using 5.0 min trapping with respect to conventional FAAS. MIBK was selected as organic solvent for the re-atomization of Bi from the trapping surface. Limit of detection values for W-coated SQT-FAAS and W-coated SQT-AT-FAAS was obtained as 0.14 ?g mL- 1 and 0.51 ng mL- 1, respectively. Linear calibration plot was obtained in the range of 2.5-25.0 ng mL- 1 for W-coated SQT-AT-FAAS. Accuracy of the W-coated SQT-AT-FAAS system was checked by analyzing a standard reference material, NIST 1643e.

K?l?nç, Ersin; Bak?rdere, Sezgin; Ayd?n, F?rat; Ataman, O. Yavuz

2013-11-01

60

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

PubMed

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

El-Daoushy, Farid; Hernández, Francisco

2002-07-01

61

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

NASA Technical Reports Server (NTRS)

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.

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

62

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

PubMed

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

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

63

High-Speed MS/MS in Situ Imaging by Nanospray Desorption Electrospray Ionization Mass Spectrometry  

PubMed Central

Nanospray desorption electrospray ionization (nano-DESI) combined with tandem mass spectrometry (MS/MS), high-resolution mass analysis of the fragment ions (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 pre-treatment. MS/MS imaging was performed by scanning the sample under the nano-DESI probe at 10 ?m/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 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 a full-scan mode. Furthermore, we identified several metabolites associated with early pregnancy and obtained the first 2D images of these molecules. PMID:24040919

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

2013-01-01

64

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

PubMed

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

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

2015-01-01

65

In situ trace-element analysis of individual silicate melt inclusions by laser ablation microprobe-inductively coupled plasma-mass spectrometry (LAM-ICP-MS)  

Microsoft Academic Search

This paper reports the successful application of laser ablation microprobe-inductively coupled plasma-mass spectrometry (LAM-ICP-MS) to the in situ analysis of a diverse suite of twenty trace elements including Zr, Hf, Nb, Ta, Y, and REEs, in individual silicate melt inclusions in phenocrysts from Fantale volcano, Ethiopia. The UV laser, a frequency quadrupled Nd: YAG operating at 266 nm, significantly improves

R. P. Taylor; S. E. Jackson; H. P. Longerich; J. D. Webster

1997-01-01

66

Trace analysis of phenolic xenoestrogens in water samples by stir bar sorptive extraction with in situ derivatization and thermal desorption–gas chromatography–mass spectrometry  

Microsoft Academic Search

A method for the simultaneous measurement of trace amounts of phenolic xenoestrogens, such as 2,4-dichlorophenol (2,4-DCP), 4-tert-butylphenol (BP), 4-tert-octylphenol (OP), 4-nonylphenol (NP), pentachlorophenol (PCP) and bisphenol A (BPA), in water samples was developed using stir bar sorptive extraction (SBSE) with in situ derivatization followed by thermal desorption (TD)–gas chromatography–mass spectrometry (GC–MS) analysis. The conditions for derivatization with acetic acid anhydride

Migaku Kawaguchi; Koichi Inoue; Mariko Yoshimura; Norihiro Sakui; Noriya Okanouchi; Rie Ito; Yoshihiro Yoshimura; Hiroyuki Nakazawa

2004-01-01

67

Liquid phase microextraction with in situ derivatization for measurement of bisphenol A in river water sample by gas chromatography–mass spectrometry  

Microsoft Academic Search

A new method that involves liquid phase microextraction (LPME) with in situ derivatization and gas chromatography–mass spectrometry (GC–MS) is described for the determination of trace amounts of bisphenol A (BPA) in river water samples. The LPME conditions, such as the type of extraction solvent and the extraction time, are investigated. Then, the extract is directly injected into GC–MS. The detection

Migaku Kawaguchi; Rie Ito; Naoyuki Endo; Noriya Okanouchi; Norihiro Sakui; Koichi Saito; Hiroyuki Nakazawa

2006-01-01

68

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

NASA Technical Reports Server (NTRS)

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.

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

2010-01-01

69

Electrooxidation of glycerol studied by combined in-situ IR spectroscopy and online mass spectrometry under continuous flow conditions  

E-print Network

Electrooxidation of glycerol studied by combined in-situ IR spectroscopy and online mass-electrochemical DEMS/ATR-FTIRS set-up, we have investigated the adsorption/oxidation of glycerol on a Pt thin film dependent development of the glycerol adlayer was followed by highly surface sensitive in-situ ATR

Pfeifer, Holger

70

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

Microsoft Academic Search

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

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

2010-01-01

71

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

SciTech Connect

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.

Soo, P.; Heiser, J.

1996-02-01

72

Gamma spectrometry and plastic-scintillator inherent background  

Microsoft Academic Search

The authors measured the energy resolution for a linear dependence of light yield on gamma radiation energy of gamma spectrometers based on plastic scintillation detectors for several plastic scintillators. If there were several gamma lines from the source the line with the highest energy was used to eliminate distortion due to overlap from the Compton background from gamma radiation of

V. V. Pomerantsev; I. B. Gagauz; L. I. Mitsai; V. S. Pilipenko; V. M. Solomonov; V. V. Chernikov; Y. A. Tsirlin

1988-01-01

73

Deformation and fracture behavior of Ni-Mo-Al(gamma/gamma prime-alpha) in situ composite  

NASA Technical Reports Server (NTRS)

Tensile properties of a directionally solidified (DS) eutectic alloy of the nominal composition Ni-33 Mo-5.7 Al (weight percent) have been investigated both at room temperature and elevated temperatures. The microstructure-mechanical property relationship has been studied for the alloy both in the as-DS and heat-treated conditions. Changes in the yield strength, the work hardening behavior, and the fracture morphology have been explained in terms of the microstructural changes due to the heat treatment. The yield drops observed have been attributed to the microdebonding due to the possible segregation of impurities at the fiber-matrix interface, and partly to the strain aging. The deformation mechanism has been identified to be the cutting of gamma prime particles.

Sriramamurthy, A. M.; Tewari, S. N.

1984-01-01

74

Quantification of uranium-238 in environmental samples using gamma-ray spectrometry  

NASA Astrophysics Data System (ADS)

A large number of environmental samples are routinely measured world-wide using gamma-ray spectrometry some of its assets being easy sample preparation and comprehensive data for many radionu-clides in one analysis. Although other techniques can be considered more suitable for analysing 238U in environmental samples, it is also routinely done by gamma-ray spectrometry. One mainly uses ?-ray emissions following the decay of the first daughter, 234Th, for determining the 238U activity. However, the low-energy gamma-rays at 63 keV and 92.5 keV are very difficult to quantify in a robust way due to high attenuation and interferences. This paper quantifies parameters affecting the possibility of making robust quantification of 238U via 234Th using gamma-ray spectrometry. It addresses the use of correct decay data, suitable detectors, optimised sample size, enhanced spectral amplification, correction for peak interferences and control of background.

Hult, M.; Andreotti, E.; González de Orduña, R.; Pommé, S.; Yeltepe, E.

2012-04-01

75

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

PubMed

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

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

2014-09-01

76

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...

77

Taking borehole conditions algorithmically into account in the. gamma. spectrometry of rock  

SciTech Connect

In the present work, an analytical model permitting an operative algorithmic interpretation of the data of borehole gamma spectrometry is briefly described. The spectrometry of the natural gamma radiation of rock permits significant increase in the efficiency of solving problems of oil-gas geophysics associated with the surveying and exploitation of oil and gas deposits, calculation of the reserves, and increasing the petroleum output of beds. The meteorological parameters of the interpretational model are presented. The universal dependence of the bed value for a centered instrument and an instrument passed to the borehole wall on the dimensionless parameter is shown.

Kozhevnikov, D.A.

1987-01-01

78

Temperature dependence of gain shift in gamma-ray spectrometry system involving a long connecting cable.  

PubMed

This work demonstrates the possibility of a gain shift or a peak-shape-deterioration with changes in the temperature of a long connecting cable between a pre-amplifier and a main amplifier in a Ge gamma-ray spectrometry system. The tests were performed for 50m-long RG174/U and RG58C/U cables with and without the termination. Such a temperature effect may cause from the temperature dependence of the resistivity of a central copper wire. In order to minimize such temperature effects in a Ge gamma-ray spectrometry, use of a terminator should be avoided. PMID:20022513

Kawada, Y; Yamada, T; Nagai, A

2010-01-01

79

A simple method for the absolute determination of uranium enrichment by high-resolution gamma spectrometry.  

PubMed

A simple method for the determination of uranium enrichment using high-resolution gamma spectrometry is presented in this paper. The method relies solely on the gamma-ray emission probabilities of 235U and 234mPa, and an iterative procedure for the least squares fit of a polynomial to a set of experimentally determined data. To ensure the reliability of the 234mPa gamma-ray emission probabilities employed, a new determination of these probabilities was carried out using a combination of gamma spectrometry and Cerenkov counting of a purified 234Th solution. Using these new data, a maximum difference of approximately 5% has been found between the experimental and declared uranium enrichment in a set of solid and liquid samples containing uranium compounds. PMID:16311038

Korob, R O; Blasiyh Nuño, G A

2006-05-01

80

Determination of basic degradation products of chemical warfare agents in water using hollow fibre-protected liquid-phase microextraction with in-situ derivatisation followed by gas chromatography–mass spectrometry  

Microsoft Academic Search

Hollow fibre-protected liquid-phase microextraction (HF-LPME) together with gas chromatography–mass spectrometry was, for the first time, investigated for the in-situ derivatisation and analysis of basic degradation products of chemical warfare agents in water samples. The degradation products studied were those of nerve and blister agents, and a psychotomimetic agent. Extractions with in-situ derivatisation were successfully performed using a mixture of solvent

Hoi Sim Nancy Lee; Mui Tiang Sng; Chanbasha Basheer; Hian Kee Lee

2008-01-01

81

In situ Pb geochronology of zircon with laser ablation–inductively coupled plasma–sector field mass spectrometry  

Microsoft Academic Search

The in situ Pb geochronological capabilities of a laser ablation–inductively coupled plasma–mass spectrometer (LA–ICP–MS) coupling a magnetic sector ICP–MS with a Nd:YAG laser probe working at 213 nm have been tested on three zircon populations with different age (150–294–577 Ma) and radiogenic Pb contents (0.7–10–40 ppm). The influence of scan mode and spatial resolution on age precision and accuracy has

Massimo Tiepolo

2003-01-01

82

Pulser injection with subsequent removal for gamma-ray spectrometry  

DOEpatents

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.

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

83

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

NASA Astrophysics Data System (ADS)

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 Henry’s 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.

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

2010-12-01

84

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

Microsoft Academic Search

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

S. C. Lee; M. C. Edelson

1992-01-01

85

Gamma spectrometry and calibration methods used in neutron dosimetry  

Microsoft Academic Search

Neutron activation rates are calculated from measured gamma-ray spectral data obtained from calibrated lithium drifted germanium (Ge(Li)) detectors. The calibration techniques, which include energy, efficiency, pulse height analyzer data reduction, and geometry factors, are discussed. Problems encountered when analyzing highly radioactive samples, specifically random coincidence summing, sample size, air absorption, and use of absorbers, are also discussed briefly. To illustrate

R. L. Malewicki; R. R. Heinrich; R. J. Popek

1979-01-01

86

Intercomparison of efficiency transfer software for gamma-ray spectrometry  

Microsoft Academic Search

The EUROMET project 428 examines efficiency transfer results for Ge gamma-ray spectrometers when the efficiency is known for a reference point source geometry. For this, different methods are used, such as Monte Carlo simulation or semi-empirical computation. The exercise compares the application of these methods to the same selected experimental cases to determine the usage limitations versus the requested accuracy.

M. C. Lépy; T. Altzitzoglou; D. Arnold; F. Bronson; R. Capote Noy; M. Décombaz; F. De Corte; R. Edelmaier; E. Herrera Peraza; S. Klemola; M. Korun; M. Kralik; H. Neder; J. Plagnard; S. Pommé; J. de Sanoit; O. Sima; F. Ugletveit; L. Van Velzen; T. Vidmar

2001-01-01

87

High accuracy in situ radiometric mapping.  

PubMed

In situ and airborne gamma ray spectrometry have been shown to provide rapid and spatially representative estimates of environmental radioactivity across a range of landscapes. However, one of the principal limitations of this technique has been the influence of changes in the vertical distribution of the source (e.g. 137Cs) on the observed photon fluence resulting in a significant reduction in the accuracy of the in situ activity measurement. A flexible approach for single gamma photon emitting radionuclides is presented, which relies on the quantification of forward scattering (or valley region between the full energy peak and Compton edge) within the gamma ray spectrum to compensate for changes in the 137Cs vertical activity distribution. This novel in situ method lends itself to the mapping of activity concentrations in environments that exhibit systematic changes in the vertical activity distribution. The robustness of this approach has been demonstrated in a salt marsh environment on the Solway coast, SW Scotland, with both a 7.6 cm x 7.6 cm NaI(Tl) detector and a 35% n-type HPGe detector. Application to ploughed field environments has also been demonstrated using HPGe detector, including its application to the estimation of field moist bulk density and soil erosion measurement. Ongoing research work is also outlined. PMID:15162872

Tyler, Andrew N

2004-01-01

88

Characterising in situ activation and degradation of hindered amine light stabilisers using liquid extraction surface analysis-mass spectrometry.  

PubMed

Changes in the molecular structure of polymer antioxidants such as hindered amine light stabilisers (HALS) is central to their efficacy in retarding polymer degradation and therefore requires careful monitoring during their in-service lifetime. The HALS, bis-(1-octyloxy-2,2,6,6-tetramethyl-4-piperidinyl) sebacate (TIN123) and bis-(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate (TIN292), were formulated in different polymer systems and then exposed to various curing and ageing treatments to simulate in-service use. Samples of these coatings were then analysed directly using liquid extraction surface analysis (LESA) coupled with a triple quadrupole mass spectrometer. Analysis of TIN123 formulated in a cross-linked polyester revealed that the polymer matrix protected TIN123 from undergoing extensive thermal degradation that would normally occur at 292°C, specifically, changes at the 1- and 4-positions of the piperidine groups. The effect of thermal versus photo-oxidative degradation was also compared for TIN292 formulated in polyacrylate films by monitoring the in situ conversion of N-CH3 substituted piperidines to N-H. The analysis confirmed that UV light was required for the conversion of N-CH3 moieties to N-H - a major pathway in the antioxidant protection of polymers - whereas this conversion was not observed with thermal degradation. The use of tandem mass spectrometric techniques, including precursor-ion scanning, is shown to be highly sensitive and specific for detecting molecular-level changes in HALS compounds and, when coupled with LESA, able to monitor these changes in situ with speed and reproducibility. PMID:24370104

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

2014-01-15

89

On line gamma-ray spectrometry at open sea.  

PubMed

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

Tsabaris, C; Ballas, D

2005-01-01

90

Computerized gamma spectrometry at the Helsinki University of Technology  

NASA Astrophysics Data System (ADS)

In this paper we describe our approach to designing a system for rapid and accurate processing of gamma spectra. Our measurements are done in a separate measuring station which consists of conventional equipment centered around a multichannel analyzer. The measured spectra are then transferred to a Nova 2 minicomputer based analysis station via a 70 m long cable at a 9600 baud rate with a special control program. Analyses can be performed with our new SAMPO80 code on the Nova or the data can be further transferred into the computer network of the University with another control program. Various aspects of the system design and development are discussed.

Aarnio, P. A.; Koskelo, M. J.

91

A new extraction technique for in situ analyses of amino and carboxylic acids on Mars by gas chromatography mass spectrometry  

NASA Astrophysics Data System (ADS)

In order to target key organic compounds in the Martian regolith using gas chromatography mass spectrometry (GC-MS), we have developed a new extraction procedure coupled with chemical derivatization. This new technique was tested on a Mars analog soil sample collected from the Atacama Desert in Chile. We found that amino and carboxylic acids can be extracted from the Atacama soil in a 1:1 mixture of isopropanol and water after ultrasonic treatment for 30 min. The extracted organic compounds were then derivatized in a single-step reaction using N-methyl- N-( tert-butyldimethylsilyl)-trifluoroacetamide (MTBSTFA) as the silylating agent in order to transform these compounds into volatile species that can then be detected by GC-MS. We are currently developing a miniaturized reaction cell suited for spaceflight, where both organic extraction and chemical derivatization processes can take place in a single step.

Buch, A.; Glavin, D. P.; Sternberg, R.; Szopa, C.; Rodier, C.; Navarro-González, R.; Raulin, F.; Cabane, M.; Mahaffy, P. R.

2006-12-01

92

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

PubMed Central

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

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

2014-01-01

93

Adsorbers for In-Situ Collection and At-Sea Gamma Analysis of Dissolved Thorium-234 in Seawater.  

National Technical Information Service (NTIS)

Two polypropylene cartridge types (Beta Pure and Hytrex II) were tested in the laboratory as adsorbers for in-situ collection of dissolved Thorium-234 (234Th) in seawater. Using a uranyl nitrate tracer, we determined that a MnO2 impregnated 3.25-inch Hytr...

M. C. Hartman, K. O. Buesseler

1994-01-01

94

Well Ge and semi-planar Ge (HP) detectors for low-level gamma-spectrometry  

NASA Astrophysics Data System (ADS)

Two gamma spectrometers, a well Ge and a semi-planar Ge (HP), are now installed and calibrated for measurements of environmental radioactivity with special attention being paid to the requirements needed for aquatic mass-balance studies, including isotope-particle dynamics and dating of recent deposits. These facilities will complement the previously developed isotope dilution alpha spectrometry (PIPS detectors) and radon emanation (ionization chambers) techniques for 210Pb dating. A careful evaluation of efficiencies and background of the Ge detectors, together with the influence of the sample's intrinsic activity on the lower limit of detection (LLD), allowed us to study the relative importance of detector and shield specifications on low level gamma spectrometry of environmental samples with various sizes and composition.

El-Daoushy, F.; Garcia-Tenorio, R.

1995-02-01

95

gamma. -ray spectrometry for determination of radium-228 and radium-226 in natural waters  

Microsoft Academic Search

A technique has been developed for the measurement of ²²⁸Ra and ²²⁶Ra in both fresh- and seawater using Ge(Li) ..gamma..-ray spectrometry. Radium isotopes are preconcentrated in the field from 100 to 1000 L onto Mn-impregnated acrylic fiber cartridges, leached from the fiber and coprecipitated with BaSOâ. Lower limits of detection are controlled by the volume of water processed through the

Jacqueline. Michel; Willard S. Moore; Philip T. King

1981-01-01

96

Use of liquid chromatography/tandem mass spectrometry to detect distinctive indicators of in situ RDX transformation in contaminated groundwater.  

PubMed

An important element of monitored natural attenuation is the detection in groundwater of distinctive products of pollutant degradation or transformation. In this study, three distinctive products of the explosive RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) were detected in contaminated groundwater from the Iowa Army Ammunition Plant; the products were MNX (hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine), DNX (hexahydro-1,3-dinitroso-5-nitro-1,3,5-triazine), and TNX (hexahydro-1,3,5-trinitroso-1,3,5-triazine). These compounds are powerful indicators of RDX transformation for several reasons: (a) they have unique chemical features that reveal their origin as RDX daughter products, (b) they have no known commercial, industrial, or natural sources, and (c) they are well documented as anaerobic RDX metabolites in laboratory studies. The products were analyzed by LC/MS/MS (liquid chromatography/mass spectrometry/mass spectrometry) with selected reaction monitoring and internal standard quantification using [ring-U-15N]RDX. Validation tests showed the novel LC/MS/MS method to be of favorable sensitivity (detection limits ca. 0.1 microg/L), accuracy, and precision. The products, which were detected in all groundwater samples with RDX concentrations of > ca. 1 microg/L (25 out of 55 samples analyzed), were present at concentrations ranging from near the detection limit to 430 microg/L. MNX was the typically the most abundant of the three nitroso-substituted products; concentrations of the products seldom exceeded 4 mol % of the RDX concentration, although they ranged as high as 26 mol % (TNX). Geographic and temporal distributions of RDX, MNX, DNX, and TNX were assessed. A degradation product resulting from RDX ring cleavage, methylenedinitramine, was not detected by LC/MS/MS in any sample (detection limit ca. 0.6-4 microg/L). This extensive field characterization of MNX, DNX, and TNX distributions in groundwater by a highly selective analytical method (LC/MS/MS) is significant because very little is known about the occurrence of intrinsic RDX transformation in contaminated aquifers. PMID:12026993

Beller, Harry R; Tiemeier, Kevin

2002-05-01

97

Determination of plutonium in nuclear materials with the combination of alpha and gamma spectrometry  

NASA Astrophysics Data System (ADS)

Alpha-particle spectrometry (AS) and high-resolution gamma spectrometry (HRGS) are jointly used for the determination of plutonium concentration in various materials containing this element. With AS the alpha activity ratios of 238Pu/( 239Pu + 240Pu) in spiked and unspiked samples and with HRGS the isotopic composition of plutonium in unspiked samples have been measured. The plutonium concentrations are calculated from the isotope dilution formula and are compared with the results from isotope dilution mass spectrometry (IDMS). The relative differences between the results of both methods are within ± 1%. Several factors such as the quality of alpha sources, sample size and the errors in HRGS affect the results and they are discussed in detail.

Parus, J. L.; Raab, W.

1996-02-01

98

Real time in situ chemical characterization of submicrometer organic particles using direct analysis in real time-mass spectrometry.  

PubMed

Direct analysis in real time mass spectrometry (DART-MS) is used to analyze the surface chemical composition of nanometer-sized organic aerosol particles in real time at atmospheric pressure. By introducing a stream of particles in between the DART ionization source and the atmospheric pressure inlet of the mass spectrometer, the aerosol is exposed to a thermal flow of helium or nitrogen gas containing some fraction of metastable helium atoms or nitrogen molecules. In this configuration, the molecular constituents of organic particles are desorbed, ionized, and detected with reduced molecular ion fragmentation, allowing for compositional identification. Aerosol particles detected include alkanes, alkenes, acids, esters, alcohols, aldehydes, and amino acids. The ion signal produced by DART-MS scales with the aerosol surface area rather than volume, suggesting that DART-MS is a viable technique to measure the chemical composition of the particle interface. For oleic acid, particle size measurements of the aerosol stream exiting the ionization region suggest that the probing depth depends upon the desorption temperature, and the probing depth is estimated to be on the order of 5 nm for a 185 nm diameter particle at a DART heater temperature of 500 °C with nitrogen as the DART gas. The reaction of ozone with submicrometer oleic acid particles is measured to demonstrate the ability of this technique to identify products and quantify reaction rates in a heterogeneous reaction. PMID:23330910

Nah, Theodora; Chan, ManNin; Leone, Stephen R; Wilson, Kevin R

2013-02-19

99

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

SciTech Connect

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.

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

1992-12-01

100

Oxidative electrolyte solvent degradation in lithium-ion batteries. An in situ differential electrochemical mass spectrometry investigation  

SciTech Connect

Differential electrochemical mass spectrometry (DEMS) was used to study the electrochemical decomposition of organic carbonate electrolyte solutions at practical lithium metal oxide composite electrodes used in lithium-ion batteries. For propylene carbonate (PC), CO{sub 2} evolution was detected at LiNiO{sub 2}, LiCoO{sub 2}, and LiMn{sub 2}O{sub 4} composite electrodes. The starting point of gas evolution was 4.2 V vs. Li/Li{sup +} at LiNiO{sub 2}, whereas at LiCoO{sub 2} and LiMn{sub 2}O{sub 4}, CO{sub 2} evolution was observed only above 4.8 V vs. Li/Li{sup +}. In addition, various other volatile electrolyte decomposition products of PC were detected when using LiCoO{sub 2}, LiMn{sub 2}O{sub 4}, and carbon black electrodes. In ethylene carbonate/dimethylcarbonate, CO{sub 2} evolution was detected only at LiNiO{sub 2} electrodes, again starting at about 4.2 V vs. Li/Li{sup +}.

Imhof, R.; Novak, P. [Paul Scherrer Inst., Villigen PSI (Switzerland). Electrochemistry Section] [Paul Scherrer Inst., Villigen PSI (Switzerland). Electrochemistry Section

1999-05-01

101

Cadium-Zinc-Telluride (CZT) Gamma Ray Spectrometry  

SciTech Connect

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.

William Quam

2001-09-01

102

Microextraction by packed sorbent for the analysis of pharmaceutical residues in environmental water samples by in situ derivatization-programmed temperature vaporizer-gas chromatography-mass spectrometry.  

PubMed

The present work describes the development and validation of a method for the determination of five non-steroidal anti-inflammatory drugs (NSAIDs: clofibric acid, ibuprofen, naproxen, diclofenac and ketoprofen) in water samples. The fully automated method includes in situ aqueous derivatization followed by analyte enrichment by microextraction by packed sorbent (MEPS) coupled directly to programmed temperature vaporizer-gas chromatography-mass spectrometry (PTV-GC-MS). The MEPS variables, such as sample volume, elution solvent, elution volume, fill and injection speed and washing steps were optimized. It was possible to use the MEPS polymer (silica-C18) 250 times. Ibuprofen-d3 was used as internal standard. The reproducibility of the method, calculated as the relative standard deviation (RSD), was below 10% for all compounds. Detection limits in ultrapure water were between 3.0 and 110 ngL(-1) for ibuprofen and ketoprofen, respectively. External calibration was used in the determination of NSAIDs in several types of water samples, including tap, river, sea and influent and effluent wastewater. The results obtained revealed the presence of ibuprofen and naproxen in the influent wastewater sample and of naproxen in the effluent wastewater sample. PMID:22129572

Noche, Gloria Grueiro; Laespada, María Esther Fernández; Pavón, José Luis Pérez; Cordero, Bernardo Moreno; Lorenzo, Soledad Muniategui

2011-12-30

103

Assessment of field portable X-ray fluorescence spectrometry for the in situ determination of heavy metals in soils and plants.  

PubMed

In soil pollution studies, large numbers of soil samples collected at random need to be processed and analyzed to determine their heavy metal contents. This study was designed to assess the use of a field portable X-ray fluorescence (FPXRF) spectrometry system for the in situ determination of heavy metal levels in both soil and plant samples. First, we optimised the method using 84 reference soil standards and soil samples from known polluted sites. The optimised method was then used to determine heavy metals at three abandoned mine sites and two sealed landfills in central Spain. Given that knowledge of heavy metal levels in plants is important for the ecotoxicological study of these sites, the FPXRF device was also used to determine heavy metals in plants. Our results indicate the acceptable to high quality of the data provided by the system especially for soil samples. The cost-benefits and sustainability of this instrument in relation to other techniques were also examined. The use of the FPXRF system for the study of potentially polluted sites was found to save on costs, time and materials. Results indicate its suitable use for the preliminary screening of heavy-metal polluted sites. PMID:23793270

Gutiérrez-Ginés, María Jesús; Pastor, Jesús; Hernández, Ana Jesús

2013-08-01

104

Evaluation of TASTEX task H: measurement of plutonium isotopic abundances by gamma-ray spectrometry  

SciTech Connect

This report describes a computer-based gamma spectrometer system that was developed for measuring isotopic and total plutonium concentrations in nitric acid solutions. The system was installed at the Tokai reprocessing plant where it is undergoing testing and evaluation as part of the Tokai Advanced Safeguards Exercise (TASTEX). Objectives of TASTEX Task H, High-Resolution Gamma Spectrometer for Plutonium Isotopic Analysis, the methods and equipment used, the installation and calibration of the system, and the measurements obtained from several reprocessing campaigns are discussed and described. In general, we find that measurements for gamma spectroscopy agree well with those of mass spectrometry and of other chemical analysis. The system measures both freshly processed plutonium from the product accountability tank and aged plutonium solutions from storage tanks. 14 figures, 15 tables.

Gunnink, R.; Prindle, A.L.; Asakura, Y.; Masui, J.; Ishiguro, N.; Kawasaki, A.; Kataoka, S.

1981-10-01

105

In-situ determination of cross-over point for overcoming plasma-related matrix effects in inductively coupled plasma-atomic emission spectrometry  

NASA Astrophysics Data System (ADS)

A novel method is described for overcoming plasma-related matrix effects in inductively coupled plasma-atomic emission spectrometry (ICP-AES). The method is based on measurement of the vertically resolved atomic emission of analyte within the plasma and therefore requires the addition of no reagents to the sample solution or to the plasma. Plasma-related matrix effects enhance analyte emission intensity low in the plasma but depress the same emission signal at higher positions. Such bipolar behavior is true for all emission lines and matrices that induce plasma-related interferences. The transition where the enhancement is balanced by the depression (the so-called cross-over point) results in a spatial region with no apparent matrix effects. Although it would be desirable always to perform determinations at this cross-over point, its location varies between analytes and from matrix to matrix, so it would have to be found separately for every analyte and for every sample. Here, a novel approach is developed for the in-situ determination of the location of this cross-over point. It was found that the location of the cross-over point is practically invariant for a particular analyte emission line when the concentration of the matrix was varied. As a result, it is possible to determine in-situ the location of the cross-over point for all analyte emission lines in a sample by means of a simple one-step sample dilution. When the original sample is diluted by a factor of 2 and the diluted sample is analyzed again, the extent of the matrix effect is identical (zero) between the original sample and the diluted sample at one and only one location — the cross-over point. This novel method was verified with several single-element matrices (0.05 M Na, Ca, Ba and La) and some mixed-element matrices (mixtures of Na-Ca, Ca-Ba, and a plant-sample digest). The inaccuracy in emission intensity due to the matrix effect could be as large as - 30% for conventional measurements in the normal analytical zone, but is reduced to within 5% with this new method. The major currently known limitation is that the accuracy of the method is highly sensitive to fluctuations and noise in the vertical emission-intensity profile, so the stability of the ICP system must be controlled to preferably within 1%.

Chan, George C.-Y.; Hieftje, Gary M.

2008-03-01

106

Determination of degradation products of chemical warfare agents in water using hollow fibre-protected liquid-phase microextraction with in-situ derivatisation followed by gas chromatography–mass spectrometry  

Microsoft Academic Search

Hollow fibre-protected liquid-phase microextraction (HF-LPME) together with gas chromatography\\/mass spectrometry was investigated for the analysis of degradation products of chemical warfare agents in water samples. The degradation products studied were those of nerve and blister agents, and a psychotomimetic agent. Extractions were successfully performed coupled with in-situ derivatisation using a mixture of solvent and derivatising agent. The protection of the

Hoi Sim Nancy Lee; Mui Tiang Sng; Chanbasha Basheer; Hian Kee Lee

2007-01-01

107

Determination of bisphenol A in river water and body fluid samples by stir bar sorptive extraction with in situ derivatization and thermal desorption-gas chromatography–mass spectrometry  

Microsoft Academic Search

A new method, based on stir bar sorptive extraction (SBSE) with in situ derivatization and thermal desorption (TD)-gas chromatography–mass spectrometry (GC–MS) is described for the determination of trace amounts of bisphenol A (BPA) in river water, urine, plasma, and saliva samples. The derivatization conditions with acetic acid anhydride and the SBSE conditions such as sample volumes and extraction time are

Migaku Kawaguchi; Koichi Inoue; Mariko Yoshimura; Rie Ito; Norihiro Sakui; Noriya Okanouchi; Hiroyuki Nakazawa

2004-01-01

108

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

SciTech Connect

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)

Thompson, Shannon; Rodriguez, Rene; Billock, Paul [HydroGeoLogic, Inc., 11107 Sunset Hills Road, Suite 400, Reston, VA 20190 (United States)] [HydroGeoLogic, Inc., 11107 Sunset Hills Road, Suite 400, Reston, VA 20190 (United States); Lit, Peter [Nomad Science Group, 7738 Nautilus Shell Street, Las Vegas, NV 89139 (United States)] [Nomad Science Group, 7738 Nautilus Shell Street, Las Vegas, NV 89139 (United States)

2013-07-01

109

Measuring the radium quartet (228Ra, 226Ra, 224Ra, 223Ra) in seawater samples using gamma spectrometry.  

PubMed

Radium isotopes are widely used in marine studies (eg. to trace water masses, to quantify mixing processes or to study submarine groundwater discharge). While 228Ra and 226Ra are usually measured using gamma spectrometry, short-lived Ra isotopes (224Ra and 223Ra) are usually measured using a Radium Delayed Coincidence Counter (RaDeCC). Here we show that the four radium isotopes can be analyzed using gamma spectrometry. We report 226Ra, 228Ra, 224Ra, 223Ra activities measured using low-background gamma spectrometry in standard samples, in water samples collected in the vicinity of our laboratory (La Palme and Vaccarès lagoons, France) but also in seawater samples collected in the plume of the Amazon river, off French Guyana (AMANDES project). The 223Ra and 224Ra activities determined in these samples using gamma spectrometry were compared to the activities determined using RaDeCC. Activities determined using the two techniques are in good agreement. Uncertainties associated with the 224Ra activities are similar for the two techniques. RaDeCC is more sensitive for the detection of low 223Ra activities. Gamma spectrometry thus constitutes an alternate method for the determination of short-lived Ra isotopes. PMID:20106569

van Beek, P; Souhaut, M; Reyss, J-L

2010-07-01

110

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

NASA Technical Reports Server (NTRS)

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.

Okelley, G. D.

1975-01-01

111

Technologically enhanced levels of natural radioactivity studied by gamma-ray spectrometry  

NASA Astrophysics Data System (ADS)

The pollution of the environment arising from sources emitting preconcentrated natural radionuclides was studied using low-level gamma-spectrometry. Along the upper stream of the river Sava in Slovenia (Yugoslavia) many sources with enhanced concentrations of natural radionuclides contribute to the pollution of the river. The pollution of air is usually limited to the vicinity of the sources. A planar Ge(HP) detector with a large surface showed improved sensitivity for 210Pb, U, and Ra in comparison to the 116 cm 3 Ge(Li) coaxial detector.

Brajnik, D.; Kobal, I.; Korun, M.; Miklavži?, U.

1986-11-01

112

GEANT4 Calibration of Gamma Spectrometry Efficiency for Measurements of Airborne Radioactivity on Filter Paper.  

PubMed

A simple method of efficiency calibration for gamma spectrometry was performed. This method, which focused on measuring airborne radioactivity collected on filter paper, was based on Monte Carlo simulations using the toolkit GEANT4. Experimentally, the efficiency values of an HPGe detector were calculated for a multi-gamma disk source. These efficiency values were compared to their counterparts produced by a computer code that simulated experimental conditions. Such comparison revealed biases of 24, 10, 1, 3, 7, and 3% for the radionuclides (photon energies in keV) of Ce (166), Sn (392), Cs (662), Co (1,173), Co (1,333), and Y (1,836), respectively. The output of the simulation code was in acceptable agreement with the experimental findings, thus validating the proposed method. PMID:25271933

Alrefae, Tareq

2014-11-01

113

Radioactivity Levels and Gamma-Ray Dose Rate in Soil Samples from Kohistan (Pakistan) Using Gamma-Ray Spectrometry  

NASA Astrophysics Data System (ADS)

The analysis of naturally occurring radionuclides (226Ra, 232Th and 40K) and an anthropogenic radionuclide 137Cs is carried out in some soil samples collected from Kohistan district of N.W.F.P. (Pakistan), using gamma-ray spectrometry. The gamma spectrometry is operated using a high purity Germanium (HPGe) detector coupled with a computer based high resolution multi channel analyzer. The specific activity in soil ranges from 24.72 to 78.48Bq·kg-1 for 226Ra, 21.73 to 75.28Bq·kg-1 for 232Th, 7.06 to 14.9Bq·kg-1 for 137Cs and 298.46 to 570.77Bq·kg-1 for 40K with the mean values of 42.11, 43.27, 9.5 and 418.27Bq·kg-1, respectively. The radium equivalent activity in all the soil samples is lower than the safe limit set in the OECD report (370Bq·kg-1). Man-made radionuclide 137Cs is also present in detectable amount in all soil samples. Presence of 137Cs indicates that the samples in this remote area also receive some fallout from nuclear accident in Chernobyl power plant in 1986. The internal and external hazard indices have the mean values of 0.48 and 0.37 respectively. Absorbed dose rates and effective dose equivalents are also determined for the samples. The concentration of radionuclides found in the soil samples during the present study is nominal and does not pose any potential health hazard to the general public.

Hasan, M. Khan; Ismail, M.; K., Khan; Akhter, P.

2011-01-01

114

In-situ gamma-ray site characterization of the Tatum Salt Dome Test Site in Lamar County, Mississippi  

SciTech Connect

Field surveys of gamma-ray emitting nuclides and soil core sampling were conducted at 12 sites on the Tatum Salt Dome Test Site and surrounding control areas to determine exposure rates from surficial radioactivity. 137Cs was the only man-made radionuclide detected and was most abundant at three off-site locations on cultivated lawns. 137Cs inventories at all of the on-site survey locations were lower than expected, given the high annual precipitation in the area. The vertical distributions were more extended than those reported for undisturbed sites. Pressurized ion chamber measurements indicated no significant differences in exposure rates on and off the test site.

Faller, S.H. (Environmental Protection Agency, Las Vegas, NV (United States))

1992-06-01

115

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

DOE Data Explorer

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.

Greenwood, R.E.

116

Low-level gamma spectrometry for pollution assessment in San Simón Bay (Vigo, Spain)  

NASA Astrophysics Data System (ADS)

A gamma spectrometer with HPGe detector of 50% relative efficiency and 1 cps total background has been dedicated to the measurement of an intertidal sediment core from a coastal environment at the Ría de Vigo (Spain). The area is affected by lead pollution and the source identification needs of a precise dating of the sediment core. Such a precise dating requires the measurement not only of the radionuclides directly involved in time calculation, as 210Pb and 226Ra, but also of ancillary radionuclides which inform about the dating model to apply and about the validity of its time estimation. Gamma spectrometry with Ge detectors performs a simultaneous measurement of the full content in ?-emitters of the sample. However, its use is limited by its high spectral background. We present the characteristics of our lowlevel background gamma spectrometer and also of Galea, the computing tool for the expert analysis of natural radionuclides. Both make possible to get the proper experimental results to reach a suitable dating. The results allowed us to detect a change in the sedimentation dynamics in the area under study, to verify the impact of lead pollution in the 210Pb level, to obtain a sedimentation rate by using the CF:CS model with a suitable correction factor and, finally, to validate the sediment dating.

Quintana, B.; Álvarez-Iglesias, P.; Santamaría, R.; Rubio, B.; Pérez-Arlucea, M.

2006-05-01

117

Radon fixation for determination of 224Ra, 226Ra and 228Ra via gamma-ray spectrometry  

Microsoft Academic Search

The aim of this work is the improvement of the procedure for the determination of radium isotopes activities in water, which is done through radiochemical separation and subsequent gamma-ray spectrometry. In addition, radon gas retention is studied using different activated carbon materials. The results of the IAEA Proficiency test: “Determination of radium and uranium radionuclides in water” of December 2002

M. Herranz; R. Idoeta; A. Abelairas; F. Legarda

2006-01-01

118

Use of HPGe gamma-ray spectrometry to assess the isotopic compositiion of uranium in soils.  

PubMed

Gamma-ray spectrometry was used to determine uranium activity and investigate the presence of depleted uranium in soil samples collected from camping sites of the Greek expeditionary force in Kosovo. Assessment of 238U concentrations was based on measurements of the 63.3 keV and 92.38 keV emissions of its first daughter nuclide, 234Th. To determine the isotopic ratio of 238U/235U, secular equilibrium along the two radioactive series was first ensured and thereby the contribution of 235U under the 186 keV peak was deduced. The uranium activity in the samples varied from 48 to 112 Bq kg(-1), whereas the activity ratio of 238U/235U averaged 23.1+/-4.3. PMID:12500805

Papachristodoulou, C A; Assimakopoulos, P A; Patronis, N E; Ioannides, K G

2003-01-01

119

Contribution of a germanium detector in mobile gamma-ray spectrometry. Spectral analysis and performance  

NASA Astrophysics Data System (ADS)

The sensitivity of the germanium semi-conductor detector is 30 times lower than that of the sodium iodide (NaI) detectors frequently used in airborne spectrometry. Its energy resolution however, is 20 times better, giving more accurate identification of radionuclides, especially when complex spectra are involved. The use of the germanium detector in mobile gamma-ray spectrometry provides a large amount of qualitative and quantitative information. In post-accident situations a germanium detector will be sufficient, and should therefore be used in preference to a NaI detector. An algorithm for detecting the total absorption peaks by studying the variations in the spectral profile of germanium gamma-ray spectra has been developed at the CEA. The use of digital filters that take into account the characteristics of the absorption peaks reduces the statistical fluctuations, making possible detection based on the analysis of the first and second derivatives. The absorption peak is then estimated by subtracting the background noise modelled in the detection window. This method of analysis offers the advantage of not requiring prior knowledge of the number or nature of the radionuclides to be detected. A study has been carried out to assess the specific performances of this detection software in different situations: average background noise in France and detection of artificial sources with varying activity levels. This analysis showed that the performance of our detection algorithm is very close to the theoretical detection limits, for both natural and artificial radionuclides. This algorithm is therefore well suited to the germanium type of spectral profile and to low count rates.

Gutierrez, S.; Guillot, L.; Bourgeois, C.

2002-04-01

120

Standardization of 222Rn by LSC and comparison with alpha- and gamma-spectrometry.  

PubMed

Liquid scintillation counting (LSC) was used for the measurement of 222Rn in equilibrium with its daughters, with detection efficiency close to 5. The appropriate corrections were considered, including one related to the probability that the 165-micros half-life 214Po decays during the dead time of the counter initiated by the disintegration of his parent nuclide, 214Bi. The dead-time determination of a commercial LS counter is also presented using a 222Rn standard source. The LSC 222Rn sources were prepared by transfer of 222Rn produced by a solid 226Ra source into LSC cocktail frozen at 77K, flame-sealed afterwards. They were measured using the LNHB triple coincidence counter with adjustable extending-type dead-time unit, between 8 and 100 micros; two different procedures were used to calculate an effective dead time and then to deduce the counting rate extrapolated to zero dead-time value. The LSC results were compared with those obtained by cryogenic alpha-particle spectrometry (LNHB system) and by gamma-ray spectrometry for the same radon source in the LSC vial; the geometry transfer coefficient was calculated using the ETNA software. Measurement results and uncertainties are discussed. PMID:16876423

Cassette, P; Sahagia, M; Grigorescu, L; Lépy, M C; Picolo, J L

2006-01-01

121

Investigation of the soil-plant transfer of primordial radionuclides in tomatoes by low-level gamma-ray spectrometry.  

PubMed

The paper presents actual data from investigations of the soil-plant transfer of the primordial radionuclides 40K, 238U, 226Ra, 210Pb and 227Ac for tomatoes growing at soils from former uranium mining areas. The analysis were carried out using low-level gamma-ray spectrometry in a 47 m deep underground laboratory. For tomato fruits transfer factors of (0.0007 +/- 0.0006) for 235U, (0.0021 +/- 0.0017) for 226Ra, (0.0015 +/- 0.0009) for 210Pb and (0.0018 +/- 0.0012) for 227Ac were obtained. The investigation of the soil-plant transfer by low-level gamma-ray spectrometry is often limited by the Compton-continuum from the always present high-energy gamma-ray emitter 40K. PMID:10879862

Köhler, M; Gleisberg, B; Niese, S

2000-01-01

122

Thickness metrology and end point control in W chemical vapor deposition process from SiH4 WF6 using in situ mass spectrometry  

E-print Network

Thickness metrology and end point control in W chemical vapor deposition process from SiH4 Ã?WF6-time, in situ chemical sensing has been applied to achieve reaction metrology and advanced process control-time measurement of deposited film thickness with an uncertainty less than 2%, and this thickness metrology signal

Rubloff, Gary W.

123

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E-print Network

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Laske, Gabi

124

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

SciTech Connect

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.

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

2000-07-16

125

Quantitative Analysis of CF4 Produced in the SiO2 Etching Process Using c-C4F8, C3F8, and C2F6 Plasmas by In Situ Mass Spectrometry  

NASA Astrophysics Data System (ADS)

The use of CF32+ as a specific product ion to selectively quantify CF4 produced in the SiO2 etching process using plasmas of perfluorocompounds (PFCs), such as c-C4F8, C3F8, and C2F6, has been proposed and investigated in the present experiments by measuring mass spectra inside and outside the plasmas. It is known that the CF32+ ion does not appear in the mass spectra of any stable PFCs, except for CF4. It is confirmed in the present experiments that the quantity of CF32+ originating from the CF3 radical in the mass spectra measured in situ is negligible. Other unstable chemical species in the plasmas are too small in quantity to explain the intensity of CF32+ appearing in the mass spectra measured in situ, even if they could produce stable CF32+ by ionization. It is therefore concluded that CF32+ can be used as a fingerprint of CF4 in mass spectrometry. Application of this new method for the quantitative analysis of CF4 produced in the SiO2 etching process using PFC plasmas results in CF4 production advancing significantly not only in the etching region of SiO2 but also in the downstream region of the plasmas.

Furuya, Kenji; Hatano, Yoshihiko

2004-01-01

126

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

PubMed

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 12?gkg(-1)), together with good repeatability and reproducibility values (RSD equal to or less than 10%). The limits of detection were in the 0.118-0.894?gkg(-1) range. A certified reference material was applied to validate the proposed methodology. PMID:25113872

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

2014-09-12

127

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)

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.

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

1994-01-01

128

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

SciTech Connect

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.

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

129

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

PubMed

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

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

2011-06-01

130

Investigation of Failed TRISO Fuel Assay Using Gamma-Ray Spectrometry  

NASA Astrophysics Data System (ADS)

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.

Harp, Jason Michael

131

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)

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 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 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 it has been recently hypothesised by Shiraiwa and Seinfeld (2012).

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.

2013-07-01

132

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)

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).

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

133

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

SciTech Connect

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.

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

2000-05-25

134

Simultaneous determination of Ra and Th nuclides, 238U and 227Ac in uranium mining waters by gamma-ray spectrometry  

PubMed

For the investigation of flooding processes in uranium mines, Ra and Th nuclides as well as 238U and 227Ac activities in waters were simultaneous analyzed by gamma-ray spectrometry. The activities of 227Ac and 228Th, not directly determinable by gamma-ray spectrometry, can be calculated from two consecutive measurements (approximately 25 d delay) of the progeny 227Th and 224Ra. For the short-lived radionuclides 234Th, 227Th, 223Ra and 224Ra a correction of the results to the sampling date is necessary. PMID:10724431

Kohler; Niese; Gleisberg; Jenk; Nindel

2000-03-01

135

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

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

Suzuki, Edward M

2014-03-01

136

Three Independent Techniques Localize Expression of Transcript afp-11 and Its Bioactive Peptide Products to the Paired AVK Neurons in Ascaris suum: In Situ Hybridization, Immunocytochemistry, and Single Cell Mass Spectrometry  

PubMed Central

We utilized three independent techniques, immunocytochemistry (ICC), single cell mass spectrometry (MS), and in situ hybridization (ISH), to localize neuropeptides and their transcripts in the nervous system of the nematode Ascaris suum. AF11 (SDIGISEPNFLRFa) is an endogenous peptide with potent paralytic effects on A. suum locomotory behavior. A highly specific antibody to AF11 showed robust immunostaining for AF11 in the paired AVK neurons in the ventral ganglion. We traced the processes from the AVK neurons into the ventral nerve cord and identified them as ventral cord interneurons. MS and MS/MS of single dissected AVKs detected AF11, two previously characterized peptides (AF25 and AF26), seven novel sequence-related peptides, including several sharing a PNFLRFamide C-terminus, and peptide NY, a peptide with an unrelated sequence. Also present in a subset of AVKs was AF2, a peptide encoded by the afp-4 transcript. By sequencing the afp-11 transcript, we discovered that it encodes AF11, all the AF11-related peptides detected by MS in AVK, and peptide NY. ISH detected the afp-11 transcript in AVK neurons, consistent with other techniques. ISH did not detect afp-11 in the ALA neuron, although both ICC and MS found AF11 in ca. 30% of ALAs. All 10 AF11-related peptides reduced acetylcholine-induced muscle contraction, but they differed in their rate of reversal of inhibition after removal of the peptide. PMID:23509978

2012-01-01

137

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

Microsoft Academic Search

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

D. C. Camp; H. E. Martz

1991-01-01

138

Determination of Vanadium by Instrumental Neutron Activation Analysis in Conjunction with Compton Suppression Gamma-Ray Spectrometry  

SciTech Connect

The toxicity of vanadium has been known for a long time. It is only recently that vanadium has been recognized as an essential trace element. The determination of vanadium with high precision and accuracy in tissues, foods, and other biological materials is needed for the purpose of studying its effect on human nutrition and health. Several techniques such as spectrophotometry, atomic absorption, X-ray fluorescence, and neutron activation analysis (NAA) can be used for its determination. Vanadium can be determined by NAA through its short-lived nuclide {sup 52}V produced via the {sup 51}V(n, {gamma}){sup 52}V reaction; it has a 1434.2-keV gamma ray and a half-life of 3.74 min. It has been reported that {sup 52}V has sufficient sensitivity for its measurement down to nanogram levels. However, it is seldom assayed in practice by instrumental NAA (INAA) in conjunction with conventional gamma-ray spectrometry, in particular for low vanadium content in high-salt biological materials, due to the Compton background interference from nuclides such as {sup 28}Al, {sup 38}Cl, {sup 56}Mn, and {sup 24}Na. Alternatively, radiochemical NAA or preconcentration NAA methods are used to separate vanadium from the major and interfering elements. A Compton suppression counting technique can be beneficially used under such situations. One of the objectives of this work was to fully explore the advantages of Compton suppression counting for the determination of vanadium in biological samples.

W. H. Zhang; A. Chatt

2000-11-12

139

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

PubMed

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

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

2004-01-01

140

Decay heat of ²³U fission products by beta- and gamma-ray spectrometry  

Microsoft Academic Search

The fast-rabbit facilities of the ORRR were used to irradiate 1- to 10-..mu..g samples of ²³U for 1, 10, and 100 s. Released power is observed using nuclear spectroscopy to permit separate observations of emitted ..beta.. and ..gamma.. spectra in successive time intervals. The spectra were integrated over energy to obtain total decay heat and the ..beta..- and ..gamma..-ray results

J. K. Dickens; T. A. Love; J. W. McConnell; R. W. Peelle

1976-01-01

141

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

PubMed

In this study several soil samples were collected from the Büyükeceli 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 Büyükeceli 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

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

2014-03-01

142

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

PubMed

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

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

2001-08-01

143

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

USGS Publications Warehouse

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)

Schimschal, Ulrich

1981-01-01

144

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

SciTech Connect

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.

Giles, J.R.

1996-05-01

145

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

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

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

2013-01-01

146

Real time in situ chemical characterization of sub-micron organic aerosols using Direct Analysis in Real Time mass spectrometry (DART-MS): the effect of aerosol size and volatility.  

PubMed

Direct Analysis in Real Time (DART) mass spectrometry is an atmospheric pressure ionization technique suitable for in situ chemical analysis of organic aerosols. Here, mass spectra are obtained by introducing a stream of nanometer-sized aerosols into the ionization region, which is an open space between the ion source and the atmospheric inlet of mass spectrometer. Model single component aerosols are used to show how the aerosol size and volatility influence the measured ion signals at different DART gas temperatures. The results show that for equivalent aerosol mass concentrations, the ion signal scales with particle surface area, with smaller diameter oleic acid aerosols yielding higher ion signals relative to larger diameter aerosols. For the aerosols of the same size, but different vapor pressures, the ion signal is larger for more volatile succinic acid aerosols than less volatile adipic and suberic acid particles. From the measured changes in aerosol size, produced by the DART source, the radial probing depth for these model aerosols range from 1 to 10 nm, the magnitude of which depends upon the physiochemical properties of the aerosols and DART gas temperature. An aerosol evaporation model reveals that the ion signal is correlated with changes in aerosol size and depends upon the total quantity of evaporated aerosol mass, consistent with a mechanism in which gas-phase molecules are first desorbed from the aerosol surface prior to ionization. The results of this work serve as a basis for future investigations of the mass spectra, ionization pathways, and probing depth of the aerosols using DART. PMID:23687648

Chan, Man Nin; Nah, Theodora; Wilson, Kevin R

2013-07-01

147

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

SciTech Connect

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.

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

1997-12-31

148

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

NASA Technical Reports Server (NTRS)

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).

Mancinelli, Rocco L.; White, Melisa R.

1994-01-01

149

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

NASA Astrophysics Data System (ADS)

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 0.56±0.12. 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 (0.56±0.12) 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

Rujiwarodom, Rachanee

2010-05-01

150

Measurement of Danube sediment radioactivity in Serbia and Montenegro using gamma ray spectrometry  

Microsoft Academic Search

The radionuclide content of 54 sediment samples collected from 18 locations distributed along the Vojvodina part of the Danube was determined by means of low-level, high-resolution gamma-spectroscopy. Beside the members of the natural radioactive chains of 238U, 232Th and the natural 40K, 137Cs content of Chernobyl origin was also detected. The data obtained are compared with those collected during four

I. Bikit; J. Slivka; M. Veskovi?; E. Varga; N. Žiki?-Todorovi?; D. Mr?a; S. Forkapi?

2006-01-01

151

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

SciTech Connect

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.

Tsapatsaris, Nikolaos; Beesley, A. M.; Weiher, Norbert; Schroeder, Sven L. M. [School of Chemical Engineering and Analytical Science, Molecular Materials Centre, University of Manchester, Sackville Street, P.O. Box 88. Manchester, M60 1QD (United Kingdom); Tromp, Moniek; Evans, John [School of Chemistry, University of Southhampton, Highfield, Southampton, SO17 1BJ (United Kingdom); Dent, A. J. [Diamond Light Source Ltd., Diamond House, Chilton, Didcot, Oxfordshire, OX11 0DE (United Kingdom); Harvey, Ian [Synchrotron Radiation Source (SRS), Daresbury Laboratory, Warrington, Cheshire, WA4 4AD (United Kingdom)

2007-01-19

152

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

PubMed

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

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

1999-01-01

153

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

PubMed

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

Paul, Sabyasachi; Sarkar, P K

2013-04-01

154

Natural radioactivity and radiological hazard assessment of soil using gamma-ray spectrometry.  

PubMed

Natural radioactivity in soil samples collected from different places of Bulandshahr, Hapur and Meerut city of Uttar Pradesh, India, using a low-level counting multichannel gamma-ray spectrometer system comprising an NaI(Tl) crystal. The range of (238)U, (232)Th and (40)K activity concentrations varied from 29.6 to 69.2, from 34.9 to 93.8 and from 438.2 to 719.9 , respectively. The activity concentrations of (232)Th are higher than those of (238)U in all the samples. The absorbed dose rate ranges from 53.18 to 110.95 . The values of the annual effective dose indoors are found to vary from 0.26 to 0.54 , whereas outdoors are found to vary from 0.07 to 0.14 . The annual effective dose is marginally below the international recommended value of 1 for the general public. The external and internal hazard indexes of the soil samples are below the recommended limits. The values of the gamma index in soil samples varied from 0.41 to 0.88. The values of the alpha index varied from 0.15 to 0.35. All these values of and are <1.0. It is observed from the results that there is no significant radiation hazard due to natural radionuclides of the soil samples in the studied areas. PMID:23427204

Zubair, Mohd; Verma, Deepak; Azam, Ameer; Roy, Sukanta

2013-08-01

155

Recent progress in low-level gamma imaging  

SciTech Connect

The CEA's Aladin gamma imaging system has been operated successfully for several years in nuclear plants and during decommissioning projects with additional tools such as gamma spectrometry detectors and dose rate probes. The radiological information supplied by these devices is becoming increasingly useful for establishing robust and optimized decommissioning scenarios. Recent technical improvements allow this gamma imaging system to be operated in low-level applications and with shorter acquisition times suitable for decommissioning projects. The compact portable system can be used in places inaccessible to operators. It is quick and easy to implement, notably for onsite component characterization. Feasibility trials and in situ measurements were recently carried out under low-level conditions, mainly on waste packages and glove boxes for decommissioning projects. This paper describes recent low-level in situ applications. These characterization campaigns mainly concerned gamma emitters with {gamma} energy < 700 keV. In many cases, the localization of hot spots by gamma camera was confirmed by additional measurements such as dose rate mapping and gamma spectrometry measurements. These complementary techniques associated with advanced calculation codes (MCNP, Mercure 6.2, Visiplan and Siren) offer a mobile and compact tool for specific assessment of waste packages and glove boxes. (authors)

Mahe, C.; Girones, Ph.; Lamadie, F.; Le Goaller, C. [CEA/DEN/DDCO/SDSP, CEA/Valrho, BP 17171, 30207 Bagnols sur Ceze Cedex (France)

2007-07-01

156

Rapid non-destructive quantitative estimation of urania/thoria in mixed thorium uranium di-oxide pellets by high-resolution gamma-ray spectrometry.  

PubMed

A non-destructive technique using high-resolution gamma-ray spectrometry has been standardised for quantitative estimation of uranium/thorium in mixed (ThO2-UO2) fuel pellets of varying composition. Four gamma energies were selected; two each from the uranium and thorium series and the time of counting has been optimised. This technique can be used for rapid estimation of U/Th percentage in a large number of mixed fuel pellets from a production campaign. PMID:11300408

Shriwastwa, B B; Kumar, A; Raghunath, B; Nair, M R; Abani, M C; Ramachandran, R; Majumdar, S; Ghosh, J K

2001-06-01

157

Quantification of gamma-aminobutyric acid in Sri Lankan tea by means of ultra performance tandem mass spectrometry.  

PubMed

Gamma-Aminobutyric acid (GABA), an important bioactive component of tea, acts as a major inhibitory neurotransmitter and is considered to influence other physiological processes in human as well as in planta. In the hereby presented study, the content of this valuable metabolite was investigated in two novel types of Ceylon Tea, explicitly "Silver Tips" and "White Tea", originating from minimally processed buds of the unique cultivar, "TRI 2043". The samples were subjected to hot water infusion, equivalent to the traditional beverage preparation procedure, and analyzed by means of hydrophilic interaction ultra performance liquid chromatography coupled to tandem mass spectrometry (HILIC LC-MS/MS). The registered GABA levels were compared with those obtained for the classic "Black Tea" and "Green Tea" samples from Sri Lanka. A high variation of GABA content was observed among the different tea types, especially in the case of "Silver Tips" and "White Tea", indicating the crucial influence of the manufacturing procedure (processing extent) on the final abundance of the bioactive component of interest. Furthermore, "White Tea" samples boasted the highest GABA concentration reported for this type of tea so far, reaching up to 50% of that characteristic of the high-priced "GABA Tea". Therefore, "White Tea" and "Silver Tips" were proved to be high quality tea with amounts of gamma-aminobutyric acid comparable with those described for similar types before. To our knowledge, this is the first report on HILIC LC-MS/MS application for the quantification of GABA and for in-depth characterization of teas from Sri Lanka. PMID:24868875

Carvalho, Elisabete; Punyasiri, P A Nimal; Somasiri, H P P Sudarshana; Abeysinghe, I Sarath B; Martens, Stefan

2014-04-01

158

Subsurface In Situ Elemental Composition Measurements with PING  

NASA Technical Reports Server (NTRS)

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.

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

2013-01-01

159

Subsurface In situ elemental composition measurements with PING  

NASA Astrophysics Data System (ADS)

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.

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

160

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

SciTech Connect

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)

Grena, Roberto; Scafe, Raffaele; Pisacane, Fabrizio; Pilato, Renzo; Crescenzi, Tommaso; Mazzei, Domenico [ENEA, Casaccia Research Centre, via Anguillarese 301, 00123 S. Maria di Galeria, Rome (Italy)

2010-01-15

161

Determination of Copper by Neutron Activation Analysis in Conjunction with Compton Suppression Gamma Spectrometry  

SciTech Connect

Copper is considered to be an essential element. Its accurate determination in tissues, foods, and other biological materials is needed to study the effect of copper on human nutrition and health. Using and Advance Prediction Computer Program, it has been shown that short-lived {sup 66}Cu (half-life = 5.09 min) can be used to determine copper in biological materials by instrumental neutron activation analysis (INAA). However, it is seldom done in practice-in particular, for low copper content in high-salt biological materials-because of the Compton background interference from nuclides such as {sup 28}Al, {sup 38}Cl, and {sup 24}Na. To eliminate the Compton interference, a preconcentration NAA method has recently been developed in our laboratory using reversed-phase extraction chromatography of copper followed by short irradiation and conventional gamma-spectrometric counting of {sup 66}Cu; the detection limit is {approx}5 ppb.

W. H. Zhang; A. Chatt

2000-06-04

162

Development and application of Marinelli beaker standards for monitoring radioactivity in Dairy-Products by gamma-ray spectrometry.  

PubMed

Marinelli (reentrant) beakers are recommended for measurement of low-activity radioactive environmental samples, in both liquid and solid phase. The preparation of Marinelli beaker standards of milk powder containing 232ThO2 at secular equilibrium with its daughter radionuclides was studied. Standards were prepared by mixing of known amounts of solid ThO2 and milk powder. The densities of the standards were 0.5-0.7 kg dm(-3). Measurements of calibrated Marinelli beaker standards with HPGe detector showed that the energy dependence of the efficiency is similar to that of a point source, i.e. an almost linear dependence of log-efficiency vs. log-energy in the 200-2000 keV range, however the parabolic correlation fits better. The validity of these standards was checked by comparison with certified standard reference material IAEA-152-Milk powder containing radiocesium and radiopotassium. The results obtained were found to be in a good agreement with the published certified data. The limit of detection for the determination of radiocesium by gamma ray spectrometry under the prevailing experimental conditions is 0.03 Bq (i.e. 0.8 pCi), for samples of dairy products having lower densities of 0.7 kg dm(-1). PMID:15388145

Lavi, N; Alfassi, Z B

2004-12-01

163

International Workshop on Gamma Spectrometry Analysis Codes for U and Pu Isotopics: Workshop Results and Next Steps  

SciTech Connect

In November 2008, the Institute of Nuclear Materials Management (INMM) and the European Safeguards Research and Development Association (ESARDA) co-hosted the International Workshop on Gamma Spectrometry Analysis Codes for U and Pu Isotopics at the Oak Ridge National Laboratory (ORNL). This workshop was conducted in response to needs expressed by the international safeguards community to understand better the capabilities and limitations of the codes; to ensure these codes are sustained; and to ensure updates or revisions are performed in a controlled manner. The workshop was attended by approximately 100 participants. The participants included code developers, code suppliers, safeguards specialists, domestic and international inspectors, process operators, regulators, and programme sponsors from various government agencies. The workshop provided a unique opportunity for code developers, commercial distributors and end users to interact in a hands-on laboratory environment to develop solutions for programmatic and technical issues associated with the various codes. The workshop also provided an international forum for discussing development of an internationally accepted standard test method. This paper discusses the organization of the workshop, its goals and objectives and feedback received from the participants. The paper also describes the significance of the working group's contribution to improving codes that are commonly used during inspections to verify that nuclear facilities are compliant with treaty obligations that ensure nuclear fuel cycle facilities are used for peaceful purposes.

McGinnis, Brent R [ORNL; Solodov, Alexander A [ORNL; Shipwash, Jacqueline L [ORNL; Zhernosek, Alena V [ORNL; McKinney, Teressa L [ORNL; Pickett, Chris A [ORNL; Peerani, Paolo [ORNL

2009-01-01

164

Measurement uncertainties and minimum detectable concentrations for the in situ NaI gamma spectroscopy systems used at the Fernald site.  

SciTech Connect

This report determines the uncertainties associated with measurements made by using the mobile gamma-ray spectrometers deployed at the U.S. Department of Energy's Fernald Closure Project to characterize soil contaminated with {sup 238}U, {sup 226}Ra, and {sup 232}Th. It also examines minimum detectable concentrations (MDCs) for these instruments. The spectrometers use sodium iodide (NaI) detectors and are mounted on a variety of platforms that allow access to all areas of the site, including deep excavations. They are utilized for surveying large areas to obtain distribution patterns for radionuclides in soil, determining whether activity concentrations exceed action levels for hot spots, and determining if the concentration of total uranium exceeds the allowable level for Fernald's on-site disposal facility. Soil cleanup levels at Fernald are 82 parts per million (ppm) for total uranium (27.3 pCi/g for {sup 238}U), 1.7 pCi/g for {sup 226}Ra, and 1.5 pCi/g for {sup 232}Th. The waste acceptance criterion (WAC) for total uranium for the disposal facility is 1030 ppm. Uncertainties associated with counting, efficiency calibration, the calibration pad and sources used, the vertical distribution of contaminants in soil, the use of moisture corrections, and the use of corrections to account for the loss of radon from soil are examined. (Loss of radon is an important process because measurement of {sup 226}Ra relies on emissions from progeny of {sup 226}Ra and because {sup 222}Rn is an intermediate, highly mobile decay product.) The importance of each source of uncertainty depends on the radionuclide of interest and level of contamination. The combined relative uncertainty (relative standard deviation) in measurements of dry-weight concentrations near three times the cleanup levels (the action levels for hot spots) is about 30% for 4-second measurements of {sup 238}U, 40% for {sup 226}Ra, and 20% for {sup 232}Th. (Measurement uncertainties for {sup 226}Ra are elevated because of the magnifying effect of the correction process used to account for the loss of {sup 222}Rn from soil.) For measurements of total uranium near the WAC level, the total relative uncertainty is about 20% for 4-second measurements. When only uncertainties due to counting errors are considered, a trigger level of 900 ppm can be used with 4-second measurements to determine, with a 95% level of confidence, if concentrations of total uranium in soil exceed the WAC level. The MDCs for 4-second measurements are well below three times the relevant cleanup levels for all three radionuclides considered.

Davis, M. J.

2004-07-20

165

Pile-up reconstruction algorithm for high count rate gamma-ray spectrometry  

NASA Astrophysics Data System (ADS)

In high count rate ?-ray spectrometry, the pile-up phenomenon turns out to be an important problem with respect to energy resolution and detection efficiency. Pile-up effects occur when two events are detected so close in time that instrumentation cannot properly extract information from both of them. Because this kind of data is incorrect and marginally useful, such data had to be rejected in traditional pulse processors. In times of digital pulse processing however, one can reconstruct piled-up pulse amplitudes by special algebraic approaches. In fully digital signal acquisition, the moving window deconvolution (MWD) method is commonly used. This method requires two parameters to be carefully set, namely the flattop time (dictated by the maximum rise time of the signal) and the shaping time, to accomplish the best possible energy resolution. In this way, the maximum energy resolution is accomplished, but a lot of piled-up events are rejected, reducing detection efficiency. We propose a method that restores some of the pile-up events, using a parallel block MWD implementation where the shaping time parameter differs for every MWD block. Careful detection of as many true events as possible, as well as determining their exact occurrence in time (their respective timestamps) is the key in getting the most out of the measured signal. With proper analysis logic we get more experimental information through reduced dead time, at the cost of controlled and selectively worsened energy resolution, on an event-by-event basis, achieving better overall detection efficiency. This method was tested on real experimental data where the detection efficiency of our method is higher, by a factor of 4.4(9), than the efficiency of a standard method with pile-up rejection at 500 kcps count rate.

Petrovi?, T.; Vencelj, M.; Lipoglavšek, M.; Novak, R.; Savran, D.

2013-04-01

166

Data acquisition ATCA system for neutron and gamma-rays spectrometries  

SciTech Connect

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.

Pereira, R.; Fernandes, A. G.; Sousa, J.; Varandas, C. A. F. [Associacao EURATOM/IST Centro de Fusao Nuclear, Instituto Superior Tecnico, 1049-001 Lisbon (Portugal)

2006-10-15

167

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

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

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

2014-05-01

168

Gamma  

NSDL National Science Digital Library

The Geometric Algorithms for Modeling, Motion, and Animation (GAMMA) research group is part of the Department of Computer Science at the University of North Carolina. Some of the topics of research include haptics, "robot motion planning," collision detection, and "real-time interaction with virtual environments." There are several projects that are described in detail for each of the main areas of investigation. Many recent papers are offered that describe the progress and findings of the group's research. Additionally, there is a large collection of videos demonstrating computer animation, simulation, and interactive applications. Some software can also be downloaded for the GAMMA Web site; however, access to a few of the titles must first be approved by the system administrator.

2007-07-28

169

In Situ Fabrication Technologies  

NASA Technical Reports Server (NTRS)

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.

Rolin, Terry D.; Hammond, Monica

2005-01-01

170

In-Situ Metrology: the Path to Real-Time Advanced Process Control  

E-print Network

In-Situ Metrology: the Path to Real-Time Advanced Process Control G.W. Rubloff University, process control through course correction has been mainly focused on in-line metrologies to drive run-to-run feedback and feedforward control We have developed in-situ metrologies based on mass spectrometry, acoustic

Rubloff, Gary W.

171

In Situ Surface Characterization  

NASA Technical Reports Server (NTRS)

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.

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

2011-01-01

172

In situ measurement system  

DOEpatents

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.

Lord, D.E.

1980-11-24

173

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

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

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

2012-10-01

174

Construction and Testing of a Neutron and Gamma Spectrometry System Using Pulse Shape Discrimination with an Organic Scintillator.  

National Technical Information Service (NTIS)

The goal of this thesis was to construct and test a neutron detector to measure the energy spectrum of 1 to 14-MeV neutrons in the presence of gammas. A spectrometer based on the process of pulse shape discrimination (PSD) was constructed, in which the sc...

R. S. Pope

1993-01-01

175

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

SciTech Connect

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.

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

1991-11-12

176

13 In Situ: Groundwater Bioremediation  

E-print Network

13 In Situ: Groundwater Bioremediation T. C. Hazen Lawrence Berkeley National Laboratory, Berkeley and Bioaugmentation of Groundwater ............................ 2589 5 Intrinsic Bioremediation and Modeling.1007/978-3-540-77587-4_191, # Springer-Verlag Berlin Heidelberg, 2010 #12;Abstract: In situ groundwater bioremediation of hydrocarbons

Hazen, Terry

177

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...

178

In Situ Nuclear Characterization Infrastructure  

SciTech Connect

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.

James A. Smith; J. Rory Kennedy

2011-11-01

179

Pileup Correction Algorithms for Very-High-Count-Rate Gamma-Ray Spectrometry With NaI(Tl) Detectors  

Microsoft Academic Search

In this paper, we propose algorithms that are suitable for gamma-ray spectrometric systems with Nal(Tl) detector that support pileup correction at extremely high count rates of 4 ?? 106 pulses\\/s. The following two algorithms are presented: 1) an algorithm based on modified phase-only correlation (MPOC) for the detection of the beginning of pulses and maximum likelihood estimation (MLE) for the

Miodrag Bolic; Vujo Drndarevic; Wail Gueaieb

2010-01-01

180

In situ mercury stabilization  

SciTech Connect

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.

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

2004-09-01

181

FISH - (Fluoresence In Situ Hybridization)  

NSDL National Science Digital Library

Fluorescence in situ hybridization (FISH) is a process which vividly paints chromosomes or portions of chromosomes with fluorescent molecules. This technique is useful for identifying chromosomal abnormalities and gene mapping.

Darryl Leja (National Human Genome Research Institute REV)

2005-04-04

182

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...

183

Rapid determination of radon daughters and of artificial radionuclides in air by online gamma-ray spectrometry.  

PubMed

For the determination of airborne radionuclide concentrations in real time, a fixed filter device was constructed which fits directly onto a germanium detector with standard nuclear electronics and a multichannel analyzer buffer connected via a data line to a personal computer for remote control and on-line spectrum evaluation. The on-line gamma-ray spectrometer was applied to the study of radon decay product concentrations in ground-level air and to the rapid detection of any contamination of the environmental air by artificial radionuclides. At Munich-Neuherberg, depending on the meterological conditions, the measured air concentrations of 214Pb, the first gamma-ray-emitting member of the 222Rn decay series, varied from about 1 to 50 Bq m-3. For the artificial radionuclides 60Co, 131I and 137Cs the detection limits were determined as a function of the varying natural radon daughter concentrations at sampling and counting times of 1 h or 1 day. For these radionuclides minimum detectable air activity concentrations of 0.3 or 0.001 Bq m-3, respectively, were obtained at low radon daughter levels. At high radon daughter levels the respective detection limits were found to be higher by a factor of only about 2. PMID:8393198

Hötzl, H; Winkler, R

1993-01-01

184

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)

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.

Gonsalves, Basil C.; Darby, Iain G.; Toloza, Arsenio; Mabit, Lionel; Kaiser, Ralf B.; Dercon, Gerd

2014-05-01

185

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

NASA Technical Reports Server (NTRS)

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.

Davis, P. A., Jr.

1980-01-01

186

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

NASA Astrophysics Data System (ADS)

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.

Davis, P. A.

1980-06-01

187

Determination of total fluorine in five coal reference materials by proton-induced gamma-ray emission spectrometry.  

PubMed

The direct non-destructive proton-induced gamma-ray emission (PIGE) technique with a germanium detector was applied to the determination of total fluorine concentration in five coal reference materials (BCR 40, NIST 1632b, NIST 1635, SARM 20 and USGS CLB-1). Duplicate analyses were made from five randomly selected bottles of each coal. Individual data are presented and some problems (calibration, proton stopping power, effects of sample heating by the proton beam, background estimation) which were encountered during this study are discussed. Sensitivity and reproducibility of the determinations, and homogeneity of the coal samples with respect to fluorine contents by analysis of variance were investigated. The present data are also compared with the few published values for these reference samples, including other PIGE data. The use of synthetic standards and spiked samples in the present study suggested that the PIGE method was more accurate than other techniques. PMID:18966506

Roelandts, I; Robaye, G; Delbrouck-Habaru, J M; Weber, G

1996-03-01

188

Effect of small potassium-rich dykes on regional gamma-spectrometry image of a potassium-poor volcanic complex: A case from the Doupovské hory Volcanic Complex, NW Czech Republic  

NASA Astrophysics Data System (ADS)

Basaltic rocks with low K, U and Th contents dominate the entire Volcanic Complex of the Doupovské hory Mts. Significant potassium anomaly exceeding 1.5 atomic wt.% of potassium over an area of 4 × 8 km and 2 atomic wt.% of potassium over an area of 2 × 6 km was defined by airborne gamma-ray spectrometry above the central part of the Doupovské hory Volcanic Complex. The following detailed field study, supported by field and laboratory gamma-spectrometry measurements and geochemical analyses of rock samples, resulted in discovery of a swarm of potassium-rich trachytic dykes. The existence of such highly-differentiated rocks in the volcanic complex was unknown till present. These dykes are commonly less than 1 m wide, but their potassium content varies between 4 and 8 atomic wt.%. Owing to this high-K composition and relative abundance of dykes, the dyke rocks significantly modify the regional pattern of gamma-spectrometry data. The potassium anomaly cannot be explained by the presence of Flurbühl intrusive body dominated by ijolites and essexites, as all these rocks are poor in K, with potassium typically not exceeding 1.5 wt.%. On the other hand, much more extensive intermediate trachybasaltic lavas with K content varying within the range 1.8-3 wt.% cause only minor or undetectable anomalies.

Zuzana, Skácelová; Vladislav, Rapprich; Bed?ich, Ml?och

2009-10-01

189

Radionuclides in the ground-level atmosphere in Vilnius, Lithuania, in March 2011, detected by gamma-ray spectrometry.  

PubMed

This study presents the ground-level air monitoring results obtained in Vilnius, the capital of Lithuania, on 14 March-14 April 2011 after the recent earthquake and subsequent Tsunami having a crucial impact on Japanese nuclear reactors at the Fukushima Daiichi Nuclear Power Plant (NPP) on 11 March 2011. To collect representative diurnal aerosol samples a powerful sampling system ensuring the air filtration rate of 5500 m(3) h(-1) was used. The following artificial gamma-ray emitting radionuclides have been determined: (129m)Te, (132)Te (in equilibrium with its daughter (132)I), (131)I, (134)Cs, (136)Cs and (137)Cs. Activity concentration of the globally distributed fission product (137)Cs has increased from a background value of 1.6 ?Bq m(-3) to the value of 0.9 mBq m(-3) at the beginning of April. The activity ratio (134)Cs/(137)Cs was found to be close to 1, with a slightly higher activity of (134)Cs. The maximum aerosol-associated (131)I activity concentration of 3.45 mBq m(-3) was by four orders of magnitude lower than that measured at the same location in April-May 1986 as a consequence of the Chernobyl NPP accident. The estimated gaseous fraction of iodine-131 constituted about 70% of the total (131)I activity. PMID:22541992

Gudelis, A; Druteikien?, R; Lujanien?, G; Maceika, E; Plukis, A; Remeikis, V

2012-07-01

190

Measurement of radionuclides and absorbed dose rates in soil samples of Peshawar, Pakistan, using gamma ray spectrometry.  

PubMed

The analysis of gamma-emitting radionuclides in nature, i.e. (226)Ra, (232)Th, (40)K and (137)Cs, has been carried out in soil samples collected from Peshawar University Campus and surrounding areas using a high purity germanium detector coupled with a computer-based high-resolution multichannel analyser. The activity concentrations in soil ranged from 30.20±0.65 to 61.90±0.95, 50.10±0.54 to 102.80±1.04, 373.60±4.56 to 1082±11.38 and 9.50±0.11 to 46.60±0.42 Bq kg(-1) for (226)Ra, (232)Th, (40)K and (137)Cs, with a mean value of 45±7.70, 67±12.50, 878±180 and 19±9.20 Bq kg(-1), respectively. The radium equivalent activity, internal and external hazard indices have mean values of 203.40±29.40 Bq kg(-1), 0.56 and 0.68, respectively. The mean values of outdoor and indoor absorbed dose rates in air and the annual effective dose equivalents were found to be 106.50 and 128 nGy h(-1) and 0.19 and 0.54 mSv y(-1), respectively. In the present study, (40)K was the major radionuclide present in soil samples. The presence of (137)Cs indicates that this area also received some fallout from the nuclear accident of the Chernobyl power plant in 1986. The activity concentrations of radionuclides found in soil samples during the current investigation were nominal. Therefore, they are not associated with any potential source of health hazard to the public. PMID:22397699

Khan, Hasan M; Ismail, Muhammad; Zia, Muhammad Abid; Khan, Khalid

2012-06-01

191

In situ biofilm coupon device  

DOEpatents

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.

Peyton, Brent M. (Kennewick, WA); Truex, Michael J. (Richland, WA)

1997-01-01

192

In Situ Analytical Electron Microscopy for Probing Nanoscale Electrochemistry  

SciTech Connect

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 li

Graetz J.; Meng, Y.S.; McGilvray, T.; Yang, M.-C.; Gostovic, D.; Wang, F.; Zeng, D.; Zhu, Y.

2011-10-31

193

In situ delta7Li, Li\\/Ca, and Mg\\/Ca analyses of synthetic aragonites  

Microsoft Academic Search

In situ secondary ion mass spectrometry (SIMS) analyses of delta7Li, Li\\/Ca, and Mg\\/Ca were performed on five synthetic aragonite samples precipitated from seawater at 25°C at different rates. The compositions of delta7Li in bulk aragonites and experimental fluids were measured by multicollector inductively coupled plasma-mass spectrometry (MC-ICP-MS). Both techniques yielded similar delta7Li in aragonite when SIMS analyses were corrected to

R. I. Gabitov; A. K. Schmitt; M. Rosner; K. D. McKeegan; G. A. Gaetani; A. L. Cohen; E. B. Watson; T. M. Harrison

2011-01-01

194

In situ ?7Li, Li\\/Ca, and Mg\\/Ca analyses of synthetic aragonites  

Microsoft Academic Search

In situ secondary ion mass spectrometry (SIMS) analyses of ?7Li, Li\\/Ca, and Mg\\/Ca were performed on five synthetic aragonite samples precipitated from seawater at 25°C at different rates. The compositions of ?7Li in bulk aragonites and experimental fluids were measured by multicollector inductively coupled plasma–mass spectrometry (MC-ICP-MS). Both techniques yielded similar ?7Li in aragonite when SIMS analyses were corrected to

R. I. Gabitov; A. K. Schmitt; M. Rosner; K. D. McKeegan; G. A. Gaetani; A. L. Cohen; E. B. Watson; T. M. Harrison

2011-01-01

195

Chemical-modification rescue assessed by mass spectrometry demonstrates that gamma-thia-lysine yields the same activity as lysine in aldolase.  

PubMed

The role of active site residues in fructose 1,6-bisphosphate aldolase is investigated by chemical-modification rescue. An active-site mutation, K107C, is constructed in a background where the four solvent-accessible cysteine residues are converted to alanine. The resulting mutant, tetK107C, when reacted with bromoethylamine (BrEA), shows a 40-fold increase in activity (to 80% that of wild type). Determination of the sites and their degree of modification using electrospray ionization Fourier transform mass spectrometry (ESI-FTMS) is developed, allowing correlation of activity after chemical modification rescue to the degree of modification. The stoichiometry of the reaction is 2.5 aminoethylations per subunit, as measured by ESI-FTMS. Protein modification with a double-labeled mix (1:1) of natural abundance isotope (d(0)-BrEA) and 2-bromoethyl-1,1,2,2-d4-amine hydrobromide (d(4)-BrEA), followed by dialysis and trypsin digestion, shows aminoethylated peptides as "twin peptides" separated by four mass units in ESI-FTMS analysis. Using this detection procedure under nondenaturing (native) conditions, C107 is aminoethylated, whereas the four buried thiols remain unlabeled. Aminoethylation of other residues is observed, and correlates with those peptides containing histidine, methionine, and/or the amino terminus. Quantification of the aminoethylation reaction is achieved by labeling with nondeuterated d(0)-BrEA under denaturing conditions following double labeling under native conditions. In addition to complete labeling all five thiols, the intensity of the d(0)-BrEA peak for C107 containing peptides increases, and the change in the d(0)/d(4) ratio between native and denaturing conditions shows 82 +/- 4.5% aminoethylation at C107. This correlation of modification with the recovered activity, indicates that gamma-thia-lysine replaces lysine in the catalytic mechanism. Kinetic constants measured for the rescued K107C mutant enzyme with the substrates fructose 1-phosphate and fructose 1,6-bisphosphate are consistent with the role of the positively charged lysine binding to the C6-phosphate. ESI-FTMS, combined with this double-labeling procedure, allows precise identification of sites and measurement of degree of protein modification. PMID:12070312

Hopkins, Christopher E; O'Connor, Peter B; Allen, Karen N; Costello, Catherine E; Tolan, Dean R

2002-07-01

196

In-situ spectrophotometric probe  

DOEpatents

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.

Prather, W.S.

1992-12-15

197

In-situ measurement system  

DOEpatents

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.

Lord, David E. (Livermore, CA)

1983-01-01

198

In-situ spectrophotometric probe  

DOEpatents

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.

Prather, William S. (2419 Dickey Rd., Augusta, GA 30906)

1992-01-01

199

Amplification of chromosomal DNA in situ  

DOEpatents

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.

Christian, Allen T. (Tracy, CA); Coleman, Matthew A. (Livermore, CA); Tucker, James D. (Livermore, CA)

2002-01-01

200

In situ bioremediation of petrol contaminated groundwater  

E-print Network

21/11/08 1 In situ bioremediation of petrol contaminated groundwater Guido Miguel Delgadillo EVS and facts · Likelihood of contamination · Benefits of in situ bioremediation So... Ask not what groundwater · Intrinsic BR vs. Engineered BR Anaerobic Bioremediation (1) Background · Anaerobic conditions most likely

Blouin-Demers, Gabriel

201

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...

202

LABORATORY TESTS AND IN-SITU MEASUREMENTS  

Microsoft Academic Search

Currently the knowledge about the settlement behavior of waste bodies is very limited. As a result, the interpretation of stress settlement tests in the laboratory and its concurrence with in-situ conditions can only be estimated with a great deal of reservation. Thus, prognoses about the settlement behavior of landfills are rough. The method currently in practice consists of extrapolating in-situ

Jan Bauer; Kai Münnich; Klaus Fricke

203

A system for low-level the cosmogenic 22 Na radionuclide measurement by gamma–gamma coincidence method using BGO detectors  

Microsoft Academic Search

In this study, a gamma–gamma coincidence spectrometry was developed and examined for environmental low-level cosmogenic 22Na monitoring purposes. The spectrometry consists of two bismuth germanate scintillators (BGO) and XIA LLC Digital Gamma Finder\\u000a (DGF)\\/Pixie-4 software and card package. The developed spectrometry was optimized according to the considerations of output\\u000a count rate and gamma peak energy resolution. This spectrometry provides a

Weihua ZhangJing; Jing Yi; Pawel Mekarski; Ian Hoffman; Kurt Ungar; Ari-Pekka Leppänen

2011-01-01

204

Determination of neptunium in plutonium and mixed uranium-plutonium samples by isotope dilution gamma-spectrometry with 243 Am as a spike  

Microsoft Academic Search

A method was developed for isolating neptunium from Pu, U or mixed oxide (MOX) samples and its determination by isotope dilution -spectrometry (IDGS) using239Np (243Am) as a spike. Extraction chromatography with trilaurylamine fixed on a SGX-C18 support was used for the isolation of Np. The decontamination factors for U, Pu, Am and Pa vary between 1000–2000 and 100, respectively. The

F. Sus; J. L. Parus; W. Raab

1996-01-01

205

In situ bioremediation using horizontal wells  

SciTech Connect

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.

NONE

1995-04-01

206

Gum containing calcium fluoride reinforces enamel subsurface lesions in situ.  

PubMed

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-?m distance increments from the surface showed statistical differences in hardness recovery rate between POs-Ca and POs-Ca+F in the superficial 20-?m region (p < 0.05). Fluoride mapping revealed distribution of the ion up to 20 ?m 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

Kitasako, Y; Sadr, A; Hamba, H; Ikeda, M; Tagami, J

2012-04-01

207

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...

208

A Deep-Sea Mass Spectrometer Instrument for Long-Term, In Situ Biogeochemical Monitoring  

Microsoft Academic Search

Mass spectrometry has been a major analytical tool for more than 100 years, but it has rarely been used to monitor the environment in situ. Furthermore, a deep-water instrument is even more challenging due to a lack of an effective membrane-introduction interface and an efficient high-vacuum system that will work remotely for long periods at very high pressure. Being able

A. Bossuyt; G. M. McMurtry

2004-01-01

209

Underwater mass spectrometers for in situ chemical analysis of the hydrosphere  

Microsoft Academic Search

Underwater mass spectrometry systems can be used for direct in situ detection of volatile organic compounds and dissolved\\u000a gases in oceans, lakes, rivers and waste-water streams. In this work we describe the design and operation of (1) a linear\\u000a quadrupole mass filter and (2) a quadrupole ion trap mass spectrometer interfaced, in each case, with a membrane introduction\\/fluid\\u000a control system

R. T. Short; D. P. Fries; M. L. Kerr; C. E. Lembke; S. K. Toler; P. G. Wenner; R. H. Byrne

2001-01-01

210

A Plant Peptide Encoded by CLV3 Identified by in Situ MALDI-TOF MS Analysis  

Microsoft Academic Search

The Arabidopsis CLAVATA3 (CLV3) gene encodes a stem cell-specific protein presumed to be a precursor of a secreted peptide hormone. Matrix-assisted laser desorption\\/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) applied to in situ Arabidopsis tissues determined the structure of a modified 12-amino acid peptide (MCLV3), which was derived from a conserved motif in the CLV3 sequence. Synthetic MCLV3 induced shoot and root

Tatsuhiko Kondo; Shinichiro Sawa; Atsuko Kinoshita; Satoko Mizuno; Tatsuo Kakimoto; Hiroo Fukuda; Youji Sakagami

2006-01-01

211

Using Gamma Spectrometry to Determine U, Th, and K Signatures in Cap Carbonates of the Death Valley Region and Their Relation to Other Carbonates  

Microsoft Academic Search

We collected spectral gamma data (K, U, Th) and measured sections in cap carbonates (Noonday dolomite) and cap-like carbonates (Beck Spring dolomite) of the Death Valley region in order to explore elemental changes in the post-snowball oceans. The Snowball Earth theory of Hoffman et al. (1998) proposes dramatic post-glacial chemical weathering as large concentrations of carbon were removed from the

M. Hannon; J. Lindberg; C. Barrie; T. Johnson; A. Donatelle; J. Goeden; S. Holter; T. Hickson; K. Theissen; M. Lamb

2004-01-01

212

FRAM (Fixed Energy, Response Function Analysis with Multiple Efficiency): A new, versatile gamma-ray spectrometry code for measuring the isotopic composition of plutonium  

SciTech Connect

We describe the characteristics and features and demonstrate the performance of a new code (FRAM) for determining the isotopic composition of plutonium using gamma-ray spectroscopy. This versatile code can measure an extremely wide range of isotopic compositions and is extremely easy to tailor to specialized measurement conditions. Measurement precision, accuracy, and throughput are significantly improved over previous Los Alamos National Laboratory (LANL) codes. 13 refs., 2 figs., 4 tabs.

Sampson, T.E.; Nelson, G.W.; Kelley, T.A.

1990-01-01

213

Mass spectrometry.  

NASA Technical Reports Server (NTRS)

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.

Burlingame, A. L.; Johanson, G. A.

1972-01-01

214

Accelerator mass spectrometry: Proceedings of the fourth international symposium on accelerator mass spectrometry  

SciTech Connect

This report is a volume of the journal Nuclear Instruments and Methods in Physics Research B: Beam Interactions with Materials and Atoms. This particular volume is concerned with accelerator mass spectrometry. The sections of this issue are: Advances in AMS techniques; Archaeology and ecology; Glaciology and climatology; Cosmochemistry and in situ production; Ocean and atmospheric sciences; Hydrology and geology; Astrophysics, nuclear physics and lasers.

Gove, H.E. (ed.); Litherland, A.E. (ed.); Elmore, D. (ed.)

1987-01-01

215

Non-destructive in-situ method and apparatus for determining radionuclide depth in media  

DOEpatents

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.

Xu, X. George (Clifton Park, NY); Naessens, Edward P. (West Point, NY)

2003-01-01

216

Radiation resistance of sequencing chips for in situ life detection.  

PubMed

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

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

217

Mineral exploration and soil analysis using in situ neutron activation  

USGS Publications Warehouse

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.

Senftle, F.E.; Hoyte, A.F.

1966-01-01

218

Improvement in the determination of 238U, 228-234Th, 226-228Ra, 210Pb, and 7Be by gamma spectrometry on evaporated fresh water samples.  

PubMed

For the U-Th series radionuclides investigation in natural freshwater, a simple, fast, and not laboratory intensive method which consists of evaporating the water samples to dryness in the presence of carriers is presented. The small volume of the residue (1-2 cm3) leads to a good efficiency for gamma counting and limits the self-absorption effect for the low energy gamma rays (less than 200 keV). The best efficiency is obtained with a well-type Ge detector. To determine the evaporation yields a river with a common uranium content, the Seine river (France), was selected. By using internal spikes and more conventional techniques of investigation, we demonstrate that the evaporation is quantitative for U, Th, Ra, Pb, and Be. The residue of a 3 L, standard superficial freshwater, evaporated sample was analyzed in a high efficiency, low background Ge detector, which leads to a sufficient precision for most environmental studies. The method has been applied to rain, river, and lake waters to study the impact of disused uranium mine water inputs on the 238U, 228-234Th, 226-228Ra, 210Pb, and 7Be river and lake contents in the U mining area of Limoges (France). PMID:14620828

Cazala, C; Reyss, J L; Decossas, J L; Royer, A

2003-11-01

219

In Situ Forming Polymeric Drug Delivery Systems  

PubMed Central

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

Madan, M.; Bajaj, A.; Lewis, S.; Udupa, N.; Baig, J. A.

2009-01-01

220

Deuterium/hydrogen ratio analysis of thymol, carvacrol, gamma-terpinene and p-cymene in thyme, savory and oregano essential oils by gas chromatography-pyrolysis-isotope ratio mass spectrometry.  

PubMed

Isotope ratio mass spectrometry online coupled with capillary gas chromatography (GC-Py-IRMS) on column INNOWAX is used in the origin specific analysis and the authenticity control of the phenolic essential oils (EOs). Isotopic data delta(2)H(V-SMOW) of thymol and carvacrol in natural essential oils were evidently more depleted than synthetic products (from -49 to 7 per thousand for thymol and -61 per thousand for carvacrol). delta(2)H(V-SMOW) values of p-cymene, gamma-terpinene and thymol in authentic thyme oils (Thymus vulgaris L. and Thymus zygis L.) were found from -300 to -270 per thousand, from -285 to -248 per thousand and from -259 to -234 per thousand, respectively. delta(2)H(V-SMOW) values of carvacrol and p-cymene in authentic oregano oils (Origanum heracleoticum L., Coridothymus capitatus L. and Origanum compactum L.) varied from -223 to -193 per thousand and from -284 to -259 per thousand, respectively. For authentic Satureja montana subsp. montana essential oils, the mean delta(2)H(V-SMOW) value for aromatic compounds were found to be the following: gamma-terpinene -273 per thousand (SD=4.6 per thousand) and p-cymene -283 per thousand (SD=3.0 per thousand), thymol -245 per thousand (SD=1.8 per thousand) and carvacrol -226 per thousand (SD=1.7 per thousand). In addition, p-cymene was previously found as a precursor of the biosynthesis of thymol and carvacrol in thyme oil, thus, we considered p-cymene as an endogenous reference compound (ERC) for D/H ratio analysis. The isotopic fractionation factors alpha(thymol/p-cymene)=1.05 and alpha(carvacrol/p-cymene)=1.08 were obtained and also used to control the authenticity of the phenolic EOs. PMID:16945376

Nhu-Trang, Tran-Thi; Casabianca, Hervé; Grenier-Loustalot, Marie-Florence

2006-11-01

221

Potential of natural gamma-ray spectrometry for mapping and environmental monitoring of black-sand beach deposits on the northern coast of Sinai, Egypt.  

PubMed

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

Aboelkhair, Hatem; Zaaeimah, Mostafa

2013-04-01

222

RNA in situ hybridization in Arabidopsis.  

PubMed

RNA in situ hybridization using digoxigenin-labeled riboprobes on tissue sections is a powerful technique for revealing microscopic spatial gene expression. Here, we describe an in situ hybridization method commonly practiced in Arabidopsis research labs. The highly stringent hybridization condition eliminates the usage of Ribonlucease A and gives highly specific signals. This also allows the use of longer probes which enhance signal strength without cross hybridization to closely related genes. In addition, using spin columns in template and riboprobe purification greatly reduces background signals. PMID:22589125

Wu, Miin-Feng; Wagner, Doris

2012-01-01

223

Spatial distribution of gamma radiation levels in surface soils from Jaduguda uranium mineralization zone, Jharkhand, India, using ?-ray spectrometry, and determination of outdoor dose to the population  

PubMed Central

The concentrations of natural radionuclides in surface soil samples around selected villages of Jaduguda were investigated and compared with the radioactivity level in the region. Concentrations of 238U, 232Th, and 40K were determined by a gamma ray spectrometer using the HPGe detector with 50% relative efficiency, and the radiation dose to the local population was estimated. The average estimated activity concentrations of 238U, 232Th, and 40K in the surface soil were 53.8, 44.2 and 464.2 Bq kg?1 respectively. The average absorbed dose rate in the study area was estimated to be 72.5 nGy h-1, where as the annual effective dose to the population was 0.09 mSv y-1. A correlation analysis was made between measured dose rate and individual radionuclides, in order to delineate the contribution of the respective nuclides towards dose rate. The radio-elemental concentrations of uranium, thorium and potassium estimated for the soils, in the study area, indicated the enrichment of uranium series nuclide. The results of the present study were subsequently compared with international and national recommended values. PMID:21170189

Maharana, Mandakini; Krishnan, Narayani; Sengupta, D.

2010-01-01

224

Characterization of gamma-irradiated polyethylene terephthalate by liquid-chromatography mass-spectrometry (LC MS) with atmospheric-pressure chemical ionization (APCI)  

NASA Astrophysics Data System (ADS)

Low-molecular-weight (low-MW) constituents of polyethylene terephthalate (PET), irradiated with 60Co gamma rays at 25 and 50 kGy, were analyzed by HPLC-MS with atmospheric-pressure chemical ionization (APCI). Consistent with earlier results, the concentrations of the major compounds that are present in the non-irradiated PET do not change perceptibly. However, we find a small but significant increase in terephthalic acid ethylester, from less than 1 mg/kg in the non-irradiated control to ca. 2 mg/kg after 50 kGy, which has not been described before. The finding is important because it gives an impression of the sensitivity of the analytical method. Additionally, it shows that even very radiation-resistant polymers can form measurable amounts of low-MW radiolysis products. The potential and limitations of LC-MS for the analysis of radiolysis products and unidentified migrants are briefly discussed in the context of the question: How can we validate our analytical methods for unknown analytes?

Buchalla, Rainer; Begley, Timothy H.

2006-01-01

225

DIG In Situ Hybridization Protocol (with detergent)  

E-print Network

Cat. #1 093 274) at 4o C overnight. Dilute antibody 1:1000 in B2 GOAT. DAY THREE *Wash 3X30 minutes temperature in the dark for 10 minutes to 3 days, depending on abundance of transcript. B4 Solution: 45 µl NBTDIG In Situ Hybridization Protocol (with detergent) Leslie Vosshall 2 September 2000 DAY ONE

226

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....

227

In situ photoimmunotherapy for advanced cutaneous melanoma  

Microsoft Academic Search

Currently there are no truly effective treatments for advanced melanoma (surgically unresectable stage III and IV). In situ photoimmunotherapy (ISPI) is a recently developed therapy based on physical and immunological principles that uses lasers in combination with immunostimulants to achieve clinically significant responses in advanced melanoma patients. Results from an ongoing phase I clinical trial suggest that this form of

Mark F. Naylor; Robert E. Nordquist; T. Kent Teague; David A. Adelson; Lisa A. Perry; Wei R. Chen

2008-01-01

228

Fabrication Capabilities Utilizing In Situ Materials  

NASA Technical Reports Server (NTRS)

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.

McLemore, Carole A.; Fikes, John C.; Darby, Charles A.; Good, James E.; Gilley, Scott D.

2008-01-01

229

In-Situ Burning of Spilled Oil.  

ERIC Educational Resources Information Center

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)…

Allen, Alan A.

1991-01-01

230

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...

231

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...

232

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...

233

In Situ Fiber-Optic Reflectance Monitor  

NASA Technical Reports Server (NTRS)

In situ fiber-optic reflectance monitor serves as simple means of monitoring changes in reflectance of specimen exposed to simulated outerspace or other environments in vacuum chamber. Eliminates need to remove specimen from vacuum chamber, eliminating optical changes and bleaching such removal causes in coatings.

Linton, Roger C.; Gray, Perry A.

1996-01-01

234

Optimized Autonomous Space In-situ Sensorweb  

NASA Astrophysics Data System (ADS)

A multidisciplinary team of computer scientists (WSU), earth (USGS) and space (JPL) scientists are collaborating to develop a sensor web system optimized for rapid deployment at restless volcanoes. The primary goals of this Optimized Autonomous Space In-situ Sensorweb (OASIS) are: 1) integrate complementary space and in-situ (ground-based) elements into an interactive, autonomous sensorweb; 2) advance sensorweb power and communication resource management technology; and 3) enable scalability for seamless infusion of future space and in-situ assets into the sensorweb. This three year project started with a rigorous multi-disciplinary interchange that resulted in a system requirements document aimed to guide the design of OASIS and future networks and to achieve the project stated goals. Based on those guidelines, we have developed fully self-contained in-situ nodes that integrate GPS, seismic, infrasonic and ash detection sensors. The nodes in the wireless sensor network are linked to the ground control center through a highly optimized mesh network for remote geophysical monitoring operation. OASIS also features an autonomous bidirectional interaction between ground nodes and instruments on the EO-1 space platform through a database with alarming capabilities at the command and control center. We have successfully completed two field deployments in the crater of Mount St. Helens, Washington on October 14, 2008 and July 14th, 2009 respectively, and demonstrated that sensor web technology provides unprecedented fine-scale real-time continuous data acquisition and interaction for earth science community.

Song, W.; Shirazi, B. A.; Lahusen, R.; Kedar, S.; Chien, S.; Webb, F.

2009-12-01

235

PERFORMANCE CONFIRMATION IN-SITU INSTRUMENTATION  

Microsoft Academic Search

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

N. T. Raczka

2000-01-01

236

Research paper Using in situ cosmogenic 10  

E-print Network

of polythermal ice sheets on Baffin Island, Arctic Canada Jason P. Briner a,*, Nathaniel A. Lifton b , Gifford H online 27 November 2012 Keywords: Cosmogenic nuclide Polythermal ice sheet Baffin Island In situ 14 C 10 elements of the Laurentide Ice Sheet history of north-central Baffin Island. A clearly defined erosion

Briner, Jason P.

237

Routine fluorescence in situ hybridization in soil  

Microsoft Academic Search

The use of fluorescence in situ hybridization (FISH) to identify and enumerate soil bacteria has long been hampered by the autofluorescence of soil particles masking the bacterial signals and because the need of counting hundreds of bacteria in order to achieve statistically reliable data is time consuming. Recently, it was demonstrated that Nycodenz facilitates FISH in soil by concentrating bacteria

J. Bertaux; U. Gloger; M. Schmid; A. Hartmann; S. Scheu

2007-01-01

238

Heat Balance in In situ Combustion.  

National Technical Information Service (NTIS)

A quasi-steady-burning channel model is used in this Bureau of Mines study to describe the conductive heat loss from an in situ coal combustor to the surrounding rock strata. The calculated heat losses are significantly greater than those previously estim...

R. F. Chaiken

1977-01-01

239

Raman Spectrometry.  

ERIC Educational Resources Information Center

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)

Gardiner, Derek J.

1980-01-01

240

In Situ Remediation Integrated Program: Technology summary  

SciTech Connect

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.

Not Available

1994-02-01

241

An attempt to use aerial gamma-ray spectrometry results in petrochemical assessments of the volcanic and plutonic associations of Central Anatolia (Turkey)  

NASA Astrophysics Data System (ADS)

Volcanic and magmatic rocks of Central Anatolia are fairly rich in radioelement concentrations. The aerial gamma-ray spectrometric survey data, gathered for the purpose of radioactive mineral exploration were utilized as an additional tool for the petrochemical classification of the volcanic and magmatics rocks and their environments. The survey data on acidic intrusions (e.g. granite, monzonite and syenite) have revealed radioelement concentrations to occur in wide ranges to be 2-6 wt per cent for potassium (K), 3-15 ppm for uranium (U) and 10-52 ppm for thorium (Th). The chain-like high and moderately high potassium, uranium and thorium anomalies on acid intrusives of the entire area show a halo-shaped feature. Locations and lithological compositions of the volcanic rocks namely lavas, tuffs, ignimbrites and basalts, appear to be reasonably effective on their radioelement concentrations. The highest potassium, uranium and thorium concentrations of the volcanic rocks are around 4 wt per cent, 10 ppm and 35 ppm, respectively. Consequently, depending on the location and composition, volcanics show a very wide range of air absorbed dose rate. The lowest rates, which vary between 10 and 120 nGy/hr, were calculated in the ophiolitic group, thick cultivated soil covering areas, particularly at the centre of the aerial survey area, metamorphosed rocks in the north and young basalts mostly in the Kayseri district. Their average radioelement concentrations were found to be very low, that is, 1.2 wt per cent, 2.3 ppm and 10 ppm for K, U and Th, respectively. Because of the accumulation of soluble uranium isotopes, air absorbed rates stemming from radioactivity of these isotopes at the vicinity of the Kozakl? hot spring reach 440 nGy/hr and exceed 150 nGy/hr at the vicinity of the Nev?ehir geothermal field.

Aydin, ?brahim; Aydo?an, M. Selman; Oksum, Erdinç; Koçak, Ali

2006-11-01

242

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)

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.

Karunakara, N.; Yashodhara, I.; Sudeep Kumara, K.; Tripathi, R. M.; Menon, S. N.; Kadam, S.; Chougaonkar, M. P.

243

In-Situ Characterization of Underwater Radioactive Sludge  

SciTech Connect

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)

Simpson, A.P.; Clapham, M.J.; Swinson, B. [Pajarito Scientific Corp., Santa Fe, NM (United States)

2008-07-01

244

Making a Hybrid Microfluidic Platform Compatible for In Situ Imaging by Vacuum-Based Techniques  

SciTech Connect

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.

Yang, Li; Yu, Xiao-Ying; Zhu, Zihua; Thevuthasan, Suntharampillai; Cowin, James P.

2011-10-26

245

Laser in situ monitoring of combustion processes.  

PubMed

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

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

246

Quantitative in situ nanoindentation of aluminum films  

SciTech Connect

We report the development of a method for quantitative, in situ nanoindentation in an electron microscope and its application to study the onset of deformation during the nanoindentation of aluminum films. The load-displacement curve developed during in situ nanoindentation shows the characteristic ''staircase'' instability at the onset of plastic deformation. The instability corresponds to the first appearance of dislocations in previously defect-free grains, and occurs at a force near that measured in conventional nanoindentation experiments on similarly oriented Al grains. Plastic deformation proceeds through the formation and propagation of prismatic loops punched into the material, and half-loops that emanate from the sample surface. This new experimental technique permits the direct observation of the microstructural mechanisms that operate at the onset of deformation.

Minor, Andrew M.; Stach, Eric A.; Morris Jr., J.W.

2001-04-04

247

In situ simulation: identification of systems issues.  

PubMed

The Institute of Medicine's report, To Err is Human, concluded that "medical errors are not a result of isolated individual actions but rather faulty systems, processes, and conditions that lead people to make mistakes." In situ simulation offers the unique opportunity to train the teams of people who deliver healthcare while enhancing policies, evaluating new technologies, and improving the systems that support the delivery of safe healthcare. For this reason, the Institute of Medicine, the Joint Commission, and the Agency for Healthcare Research and Quality recommend medical simulation as one of the most important safe practice interventions to reduce errors and risks associated with the process of care. This review builds on other reports in this issue and discusses the application of in situ simulation to identify, address, and test systems improvements. PMID:23721772

Guise, Jeanne-Marie; Mladenovic, Jeanette

2013-06-01

248

Quantum criticality from in situ density imaging  

SciTech Connect

We perform large-scale quantum Monte Carlo (QMC) simulations for strongly interacting bosons in a two-dimensional optical lattice trap and confirm an excellent agreement with the benchmarking in situ density measurements by the Chicago group [N. Gemelke et al., Nature (London) 460, 995 (2009)]. We further present a general finite-temperature phase diagram for both the uniform and the trapped systems, demonstrating how the universal scaling properties near the superfluid-to-Mott insulator transition can be observed from the in situ density profile. The characteristic temperature to find such quantum criticality is estimated to be of the order of the single-particle bandwidth, which should be achievable in the present experiments. Finally, we examine the validity regime of the local fluctuation-dissipation theorem, which can be a used as a thermometry in the strongly interacting regime.

Fang Shiang; Chung, Chia-Min [Physics Department, National Tsing-Hua University, Hsinchu 300, Taiwan (China); Ma, Ping Nang [Theoretische Physik, ETH Zurich, CH-8093 Zurich (Switzerland); Chen Pochung; Wang, Daw-Wei [Physics Department, National Tsing-Hua University, Hsinchu 300, Taiwan (China); Physics Division, National Center for Theoretical Sciences, Hsinchu 300, Taiwan (China)

2011-03-15

249

In situ combustion project at Bartlett, Kansas  

Microsoft Academic Search

The Bartlesville Energy Technology Center, U.S. Department of Energy, is developing petroleum-recovery techniques for shallow, low-productivity, heavy-oil deposits in SE. Kansas, SW. Missouri, and NE. Oklahoma. Personnel designed and conducted an in situ combustion experiment on the Link Lease in Labette County, Kansas. The Nelson-McNeil calculation method was used to calculate oil recovery and predict production time for a 1.25-acre

H. B. Carroll; J. Miller; K. Spence

1981-01-01

250

Excursion control at in situ uranium mines  

SciTech Connect

This paper summarizes excursions (uncontrolled movement of lixiviant beyond the ore zone) based on case histories of 8 in situ uranium mines (7 in Wyoming and 1 in Texas). These case histories were compiled from data provided by the US Nuclear Regulatory Commission, the Wyoming Department of Environmental Quality, and the Texas Department of Water Resources. Most of these data were provided to the above agencies by mining companies in response to regulatory requirements pertaining to licensing actions.

Staub, W.P.

1987-01-01

251

Practical application of in situ aerosol measurement  

SciTech Connect

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.

O`Hern, T.J.; Rader, D.J.

1993-09-01

252

In Situ Measurement of Aerosol Extinction  

NASA Technical Reports Server (NTRS)

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.

Strawa, Anthony W.; Castaneda, R.; Owano, T. G.; Bear, D.; Gore, Warren J. (Technical Monitor)

2001-01-01

253

Overview of the current definition of Ductal Carcinoma in Situ  

Cancer.gov

Ductal Carinoma in Situ: Strategies for Integrating Tumor Biology and Population Sciences February 1-2, 2007, San Francisco, CA Overview of the current definition of Ductal Carcinoma in Situ Donald L. Weaver, MD University of Vermont In the beginning… •

254

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...

255

IN-SITU BIOREMEDIATION OF CONTAMINATED GROUND WATER  

EPA Science Inventory

In-Situ bioremediation, where applicable, appears to be a potential cost-effective and environmentally acceptable remediation technology. uflita (1989) identified characteristics of the ideal candidate site for successful implementation of in-situ bioremediation. hese characteris...

256

Development of Spectroelectrochemical Cells for in situ Neutron Reflectometry  

NASA Astrophysics Data System (ADS)

A new spectroelectrochemical cell for in situ neutron reflectometry was developed. Electrochemical reactions were determined using this in situ cell with a LiMn2O4/SrRuO3 multi layer thin film. Changes in interfacial structures on the surface of the thin film are also observed by in situ neutron reflectivity measurements. The performances of this in situ cell were expected the determination of changes on the interface between the electrodes and electrolytes.

Yonemura, M.; Hirayama, M.; Suzuki, K.; Kanno, R.; Torikai, N.; Yamada, N. L.

2014-04-01

257

In-situ droplet monitoring for self-tuning spectrometers  

DOEpatents

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.

Montaser, Akbar (Potomac, MD); Jorabchi, Kaveh (Arlington, VA); Kahen, Kaveh (Kleinburg, CA)

2010-09-28

258

In situ synthesis studies of silicon clathrates  

NASA Astrophysics Data System (ADS)

Solid state clathrates have shown considerable potential as a new class of materials over the past 30 years. Experimental and theoretical studies have shown that precise tuning and synthetic control of these materials, may lead to desirable properties. Very little is known about the mechanism of formation of the clathrates and so the desire to have accurate synthetic control was, until now, unrealistic. This thesis address the problem using in situ synchrotron x-ray techniques. In this study, experiments were designed to utilise time-resolved in situ diffraction techniques and high temperature 23Na NMR, in efforts to understand the mechanism of formation for this class of expanded framework materials. A complex high vacuum capillary synthesis cell was designed for loading under inert conditions and operation under high vacuum at station 6.2 of the SRS Daresbury. The cell was designed to operate in conjunction with a custom made furnace capable of temperatures in excess of 1000 C, as well as a vacuum system capable of 10"5 bar. The clathrate system was studied in situ, using rapid data collection to elucidate the mechanism of formation. The data were analysed using Rietveld methods and showed a structural link between the monoclinic, C2/c, Zintl precursors and the cubic, Pm3n, clathrate I phase. The phases were found to be linked by relation of the sodium planes in the silicide and the sodium atoms resident at cages centres in the clathrate system. This evidence suggests the guest species is instrumental in formation of the clathrate structure by templating the formation of the cages in the structure. Solid state 23Na NMR was utilised to complete specially design experiments, similar to those complete in situ using synchrotron x-ray techniques. The experiments showed increased spherical symmetry of the alkali metal sites and suggested increased mobility of the guest atoms during heating. In addition, cyclic heating experiments using in situ diffraction showed reversible reintroduction of the guest species on heating and cooling, during formation and subsequent dissipation of the clathrate structure. The realisation of the synthesis of a guest free type II clathrate and the theoretical prediction of negative thermal expansion behaviour at low temperature prompted the use of laboratory x-ray diffraction and a liquid helium cryostat to test the prediction. Careful study of the region from 20 to 200 K showed a region of zero or negative thermal expansion in the predicted region the effect observed showed good agreement with theory.

Hutchins, Peter Thomas

259

Development of an automatic machine for in situ hybridization and immunohistochemistry.  

PubMed

An instrument for the automation of in situ hybridization and immunohistochemistry has been developed. This machine is capable of analyzing 20 microscope glass slides via all of the steps required for colorimetric in situ hybridization or immunohistochemistry. The slides are placed specimen-side down on a specialized Teflon slide-holder set in the reaction chamber of the machine. The system uses a unique type of capillary action between the slide and the holder. The holder has two small holes and is designed to apply, incubate and sequentially add and remove reagents from the slide surface. The system performs the complete processes of in situ hybridization and immunohistochemistry from dewaxing to colorization. Some applications were carried out using this instrument. Cultured cells infected with cytomegalovirus, adenovirus, or herpes simplex virus were hybridized with homologous biotinylated probes, and showed strong purple signals with alkaline phosphatase in the presence of nitroblue tetrazolium and 5-bromo-4-chloro-3-indolyl phosphate. Automatic in situ hybridization using other colorimetric detection systems (e.g., peroxidase-labeled probes/diaminobenzidine/H2O2) was also examined in cells infected with Chlamydia trachomatis and in paraffin-embedded hepatic tissue sections from patients with hepatitis. For conventional immunohistochemical staining, formalin-fixed and paraffin-embedded tissues were used. Glial fibrillary acidic protein and gamma-immunoglobulins were detected automatically in human brain white matter and tonsillar tissues, respectively, as peroxidase-based reddish signals. The intensity of staining was equal to that achieved by manual methods. PMID:1776690

Takahashi, T; Ishiguro, K

1991-08-01

260

Development of a Nanoindenter for In Situ Transmission Electron Microscopy  

E-print Network

Development of a Nanoindenter for In Situ Transmission Electron Microscopy Eric A. Stach,1 * Tony will be presented. Key words: transmission electron microscopy, nanoindentation, in situ, dislocations, deformation, that of in situ nanoindentation (Wall et al., 1995; Wall and Dahmen, 1997, 1998a,b). Their work to date has

Rubloff, Gary W.

261

Coordinated in Situ Analyses of Organic Nanoglobules in the Sutter's Mill Meteorite  

NASA Technical Reports Server (NTRS)

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).

Nakamura-Messenger, K.; Messenger, S.; Keller, L. P.; Clemett, S. J.; Nguyen, A. N.; Gibson, E. K.

2013-01-01

262

Determination of Darcian permeability of porous material by infrared spectrometry  

E-print Network

spectrometry Á Porous material Á Permeation determination Á Active cooling List of symbols KD Darcian and the pressure drop through the porous media. Due to thermo- chemical process involved in the cooling in chemical reactor engineering in order to propose a real-time in situ quantification of the Darcian

Boyer, Edmond

263

Use of a portable quadrupole mass spectrometer for the measurement of dissolved gas concentrations in ovine rumen liquor in situ  

Microsoft Academic Search

The use of membrane-inlet mass spectrometry in the study of dissolved gas concentrations in the rumen was evaluated in order to assess the value of the technique as a tool for the study of microbial activity in ecosystems in situ. Four dissolved gases (CH4, CO2, H2, and O2) were measured simultaneously and continuously for short periods (up to 30 min)

Kevin Hillman; David Lloyd; Alan G. Williams

1985-01-01

264

Environmental gamma-ray dose rate in Aomori Prefecture, Japan.  

PubMed

Japan's first commercial nuclear fuel cycling facilities, including a spent nuclear fuel reprocessing plant, are now under construction in Rokkasho, Aomori Prefecture (prefecture--an area of administration similar to a county in the U.S.). The reprocessing plant is due to be completed by 2004. We surveyed indoor and outdoor environmental gamma-ray dose rates throughout Aomori Prefecture from 1992 to 1996 to get background data before operation of the plant. Glass dosimeters were used to measure cumulative gamma-ray dose rate. The outdoor gamma-ray dose rates were measured at 109 locations in the prefecture. The indoor gamma-ray dose rates were measured at 81 locations, which were generally in a dwelling near the location of an outdoor measurement. The contribution of radionuclides in the ground to the outdoor dose rate was estimated by using in-situ gamma-ray spectrometry with a germanium detector. The spectra were measured at 20 locations used for the glass dosimeter measurements. The outdoor gamma-ray dose rate was higher in the Tsugaru area (western part of the prefecture) than in the Nanbu area (eastern part). Means of the dose rate were 28, 31, and 25 nGy h(-1) for the whole prefecture and Tsugaru and Nanbu areas, respectively. The dose rates in winter were lower than those in the other seasons due to the shielding effect of snow on the ground. Mean contributions of uranium series, thorium series and 40K to the dose rates were 7.7, 8.2, and 9.3 nGy h(-1), respectively. The indoor dose rate was generally higher than the outdoor one, and the mean ratio of indoor to outdoor dose rates was 1.42. Means of indoor gamma-ray dose rate were 41, 37, and 43 nGy h(-1) for the whole prefecture and Tsugaru and Nanbu areas, respectively. The average effective dose rate to people in the prefecture was estimated to be 0.24 mSv y(-1). PMID:11906142

Iyogi, Takashi; Ueda, Shinji; Hisamatsu, Shunichi; Kondo, Kunio; Haruta, Hideto; Katagiri, Hiromi; Kurabayashi, Mizumi; Nakamura, Yuji; Tsuji, Nobuo

2002-04-01

265

pH control with silicates minerals for in situ bioremediation of chlorinated solventsfor in situ bioremediation of chlorinated solvents  

E-print Network

pH control with silicates minerals for in situ bioremediation of chlorinated solventsfor in situ bioremediation of chlorinated solvents Elsa Lacroix(1,2), Alessandro Brovelli(2), D.A. Barry(2), Christof (tetrachloroethylene), TCE 21 In situ bioremediation of chlorinated solvents is an acid-generating process. Acidic

266

Miniaturized GC\\/MS instrumentation for in situ measurements: micro gas chromatography coupled with miniature quadrupole array and Paul ion trap mass spectrometers  

Microsoft Academic Search

Miniaturized chemical instrumentation is needed for in situ measurements in planetary exploration and other spaceflight applications where factors such as reduction in payload requirements and enhanced robustness are important. In response to this need, we are continuing to develop miniaturized GC\\/MS instrumentation which combines chemical separations by gas chromatography (GC) with mass spectrometry (MS) to provide positive identification of chemical

Paul M. Holland; Ara Chutjian; Murray R. Darrach; Otto J. Orient

2003-01-01

267

In situ reactivation of glycerol-inactivated coenzyme B12-dependent enzymes, glycerol dehydratase and diol dehydratase.  

PubMed Central

The catalytic properties of coenzyme B12-dependent glycerol dehydratase and diol dehydratase were studied in situ with Klebsiella pneumoniae cells permeabilized by toluene treatment, since the in situ enzymes approximate the in vivo conditions of the enzymes more closely than enzymes in cell-free extracts or cell homogenates. Both dehydratases in situ underwent rapid "suicidal" inactivation by glycerol during catalysis, as they do in vitro. The inactivated dehydratases in situ, however, were rapidly and continually reactivated by adenosine 5'-triphosphate (ATP) and Mn2+ in the presence of free adenosylcobalamin, although in cell-free extracts or in cell homogenates they could not be reactivated at all under the same reaction conditions. ATP was partially replaced by cytidine 5'-triphosphate or guanosine 5'-triphosphate but not by the beta, gamma-methylene analog of ATP in the in situ reactivation. Mn2+ was fully replaced by Mg2+ but only partially by Co2+. Hydroxocoblamin could not replace adenosylcobalamin in reactivation mixtures. The ability to reactivate the glycerol-inactivated dehydratases in situ was only seen in cells grown anaerobically in glycerol-containing media. This suggests that some factor(s) required for in situ reactivation is subject to induction by glycerol. Of the two possible mechanisms of in situ reactivation, i.e., the regeneration of adenosylcobalamin by Co-adenosylation of the bound inactivated coenzyme moiety (B12-adenosylation mechanism) and the displacement of the bound inactivated coenzyme moiety by free adenosyl-cobalamin (B12-exchange mechanism), the former seems very unlikely from the experimental results. Images PMID:6997273

Honda, S; Toraya, T; Fukui, S

1980-01-01

268

TSSM: The in situ exploration of Titan  

NASA Astrophysics Data System (ADS)

The Titan Saturn System Mission (TSSM) mission was born when NASA and ESA decided to collaborate on two missions independently selected by each agency: the Titan and Enceladus mission (TandEM), and Titan Explorer, a 2007 Flagship study. TandEM, the Titan and Enceladus mission, was proposed as an L-class (large) mission in response to ESA's Cosmic Vision 2015-2025 Call. The mission concept is to perform remote and in situ investigations of Titan primarily, but also of Enceladus and Saturn's magentosphere. The two satellites are tied together by location and properties, whose remarkable natures have been partly revealed by the ongoing Cassini-Huygens mission. These bodies still hold mysteries requiring a complete exploration using a variety of vehicles and instruments. TSSM will study Titan as a system, including its upper atmosphere, the interactions with the magnetosphere, the neutral atmosphere, surface, interior, origin and evolution, as well as the astrobiological potential of Titan. It is an ambitious mission because its targets are two of the most exciting and challenging bodies in the Solar System. It is designed to build on but exceed the scientific and technological accomplishments of the Cassini- Huygens mission, exploring Titan and Enceladus in ways that are not currently possible (full close-up and in situ coverage over long periods of time for Titan, several close flybys of Enceladus). One overarching goal of the TSSM mission is to explore in situ the atmosphere and surface of Titan. In the current mission architecture, TSSM consists of an orbiter (under NASA's responsibility) with a large host of instruments which would perform several Enceladus and Titan flybys before stabilizing in an orbit around Titan alone, therein delivering in situ elements (a Montgolfière, or hot air balloon, and a probe/lander). The latter are being studied by ESA. The balloon will circumnavigate Titan above the equator at an altitude of about 10 km for several months. The probe will descend through Titan's atmosphere and land on a liquid surface (at the North pole, in a lake according to the current design). The currently envisaged strawman payload for these elements will be presented. Instruments aboard the balloon would provide high resolution vistas of the surface of Titan as the balloon cruises at 10 km altitude, as well as make compositional measurements of the surface, detailed sounding of crustal layering, and chemical measurements of aerosols. A magnetometer, unimpeded by Titan's ionosphere, would permit sensitive detection of induced or intrinsic fields. The short-lived probe would splash into a large northern sea and spend several hours floating during which direct chemical and physical sampling of the liquid—a carrier for many dissolved organic species— would be undertaken. During its descent the Mare Explorer would provide the first in situ profiling of the winter northern hemispheric atmosphere, which is distinctly different from the equatorial atmosphere where Huygens descended and the balloon will arrive. Coordinated radio science experiments aboard the orbiter and in situ elements would be capable of providing detailed information on Titan's tidal response, and hence its crustal rigidity and thickness.

Coustenis, A.; Lunine, J. I.; Lebreton, J. P.; Matson, D.; Reh, K.; Beauchamp, P.; Erd, C.

2008-09-01

269

Calibrating feedwater flow nozzles in-situ  

SciTech Connect

This paper presents a new method for in-situ calibration of feedwater flow nozzles wherein feedwater flow is determined indirectly by performing a high accuracy heat balance around the highest-pressure feedwater heater. It is often difficult to reliably measure feedwater flow. Over the life of a power plant, the feedwater nozzle can accumulate deposits, erode, or suffer other damage that can render the original nozzle calibration inaccurate. Recalibration of installed feedwater flow nozzles is expensive and time consuming. Traditionally, the nozzle is cut out of the piping and sent to a laboratory for recalibration, which can be an especially difficult, expensive, and time-consuming task when involving high pressure feedwater lines. ENCOR-AMERICA, INC. has developed an accurate and cost-effective method of calibrating feedwater nozzles in-situ as previously reported at the 1994 EPRI Heat Rate Improvement Conference. In this method, feedwater flow and differential pressure across the nozzle are measured concurrently. The feedwater flow is determined indirectly by performing a heat balance around the highest-pressure feedwater heater. Extraction steam to the feedwater heater is measured by use of a high accuracy turbine flowmeter. The meters used have been calibrated at an independent laboratory with a primary or secondary device traceable to the NIST. In this paper, a new variation on the above method is reported. The new approach measures the heater drains and vent flows instead of the extraction steam flow. Test theory and instrumentation will be discussed. Results of in-situ feedwater nozzle calibration tests performed at two units owned by Tri-State Generation and Transmission Association will be presented.

Caudill, M. [Tri-State Generation and Transmission, Inc., Montrose, CA (United States); Diaz-Tous, I.; Murphy, S.; Leggett, M.; Crandall, C. [ENCOR-AMERICA, Inc., Mountain View, CA (United States)

1996-05-01

270

Survey of in-situ and remote sensing methods for soil moisture determination  

NASA Technical Reports Server (NTRS)

General methods for determining the moisture content in the surface layers of the soil based on in situ or point measurements, soil water models and remote sensing observations are surveyed. In situ methods described include gravimetric techniques, nuclear techniques based on neutron scattering or gamma-ray attenuation, electromagnetic techniques, tensiometric techniques and hygrometric techniques. Soil water models based on column mass balance treat soil moisture contents as a result of meteorological inputs (precipitation, runoff, subsurface flow) and demands (evaporation, transpiration, percolation). The remote sensing approaches are based on measurements of the diurnal range of surface temperature and the crop canopy temperature in the thermal infrared, measurements of the radar backscattering coefficient in the microwave region, and measurements of microwave emission or brightness temperature. Advantages and disadvantages of the various methods are pointed out, and it is concluded that a successful monitoring system must incorporate all of the approaches considered.

Schmugge, T. J.; Jackson, T. J.; Mckim, H. L.

1981-01-01

271

Robust and efficient in situ quantum control  

E-print Network

Precision control of quantum systems is the driving force for both quantum technology and the probing of physics at the quantum and nano-scale. 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 and 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.

Christopher Ferrie; Osama Moussa

2014-09-10

272

Measure of Legionella penumophila activity in situ  

SciTech Connect

Detection of Legionella pneumophila by serogroup-specific fluorescent antibodies was combined with a tetrazolium dye (INT) to measure electron transport activity. The biological uptake and reduction of the INT dye was studied in pure cultures and in natural water samples with respect to temperature. Uptake was complete within 60 min. Controls inhibited with formaldehyde demonstrated little activity. Both the in vitro and in situ determinations suggested that the electron transport system of Legionella was active over a temperature range of 25 to 60/sup 0/C.

Fliermans, C.B. (E.I. du Pont de Nemours and Co., Aiken, SC); Soracco, R.J.; Pope, D.H.

1981-01-01

273

Measure of Legionella pneumophila activity in situ  

SciTech Connect

Detection of Legionella pneumophila by serogroup-specific fluorescent antibodies was combined with a tetrazolium dye (INT) to measure electron transport activity. The biological uptake and reduction of the INT dye was studied in pure cultures and in natural water samples with respect to temperature. Uptake was complete within 60 minutes. Controls inhibited with formaldehyde demonstrated little activity. Both the in vitro and in situ determinations suggested that the electron transport system of Legionella was active over a temperature range of 25/sup 0/ to 60/sup 0/C.

Fliermans, C.B.; Soracco, R.J.; Pope, D.H.

1981-01-01

274

Gamma Scanning the Primary Circuit of the Peach Bottom HTGR.  

National Technical Information Service (NTIS)

The plateout distribution of gamma-emitting nuclides in the primary circuit of the Peach Bottom HTGR at end-of-life has been determined by in situ gamma scanning. The specific activity was mapped by scanning the accessible ducting at 12 locations with a G...

D. L. Hanson, N. L. Baldwin, W. E. Selph

1976-01-01

275

GAS TURBINE REHEAT USING IN SITU COMBUSTION  

SciTech Connect

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.

D.M. Bachovchin; T.E. Lippert; R.A. Newby P.G.A. Cizmas

2004-05-17

276

Dimensional characterisation of collagen constructs in situ  

NASA Astrophysics Data System (ADS)

We present results of a non contacting instrument based on the confocal scanning technique for assessing the thickness and structure of collagen substrates and tissue constructs. There is an unmet need in the creation of tissue constructs to quantitatively evaluate their dimensional characteristics during manufacture. With this knowledge more effective structures can be produced. The measurement is complicated by the need to make these measurements in situ. For many processes, including the plastic compression of collagen gels for generating 3D structures, the constructs are situated in a liquid solution contained in a well plate or similar container. It is therefore necessary to perform the measurements through an interfering medium and this confounds many measurement techniques. A system has therefore been developed that utilizes a scanning confocal arrangement to accurately measure the dimensional characteristics of these constructs in situ. A fiber based optical arrangement using compact, proven components from the telecommunications industry has been integrated into a dedicated system architecture so that the constructs can be measured whilst in production. This architecture is particularly important due to the "wet" nature of the samples. The meter can measure constructs with thicknesses from a few tens of micrometers up to 0.9 millimeters with sub-micrometer resolution. Results are presented that show how the meter has been used to evaluate changes in these collagen constructs whilst in production. This was little understood prior to these measurements and the greater understanding of how the materials behave has allowed the process to be greatly improved.

Taylor, R.; Reynolds, J.; Chikkanna, B.; Daly, D.; Brown, R. A.; Tan, N. S.

2014-02-01

277

Molecular cytogenetics using fluorescence in situ hybridization  

SciTech Connect

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.

Gray, J.W.; Kuo, Wen-Lin; Lucas, J.; Pinkel, D.; Weier, H-U.; Yu, Loh-Chung.

1990-12-07

278

In situ bioremediation under high saline conditions  

SciTech Connect

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.

Bosshard, B.; Raumin, J.; Saurohan, B.

1995-12-31

279

In situ PEM fuel cell water measurements  

SciTech Connect

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.

Borup, Rodney L [Los Alamos National Laboratory; Mukundan, Rangachary [Los Alamos National Laboratory; Davey, John R [Los Alamos National Laboratory; Spendelow, Jacob S [Los Alamos National Laboratory; Hussey, Daniel S [NIST; Jacobson, David L [NIST; Arif, Muhammad [NIST

2009-01-01

280

In Situ Instruments: Overview of In Situ Instruments for Deployment in Extreme Environments  

NASA Technical Reports Server (NTRS)

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.

Taylor, M.; Cardell, G.

2000-01-01

281

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

NASA Astrophysics Data System (ADS)

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, ? 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 ?-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/?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.

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

2007-01-01

282

In situ photoemission electron spectroscopy of plasma-nitrided metal alloys  

SciTech Connect

In this paper, we report the influence of oxygen on the structure and chemical compositions of the surface of low-energy ({approx}50 eV) implanted stainless steel studied by in situ photoemission electron spectroscopy. The presence of oxygen at the surface forms thermodynamically stable oxides and hydroxides, degrading metallic nitrides, and preventing efficient nitrogen diffusion into the bulk material. Among these metallic nitrides, {gamma}{sub N} and FeN{sub x} are more susceptible to oxidize. Lower oxygen partial pressures augment nitrogen content at the surface determining material bulk properties.

Figueroa, C.A.; Alvarez, F. [Instituto de Fisica 'Gleb Wataghin', Universidade Estadual de Campinas, Unicamp 13083-970, Campinas, Sao Paulo (Brazil)

2005-05-15

283

In-situ Resources In Space  

NASA Technical Reports Server (NTRS)

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.

Curreri, Peter A.

2005-01-01

284

Mars in Situ Resource Utilization Technology Evaluation  

NASA Technical Reports Server (NTRS)

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.

Muscatello, Anthony C.; Santago-Maldonado, Edgardo

2012-01-01

285

Support Routines for In Situ Image Processing  

NASA Technical Reports Server (NTRS)

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.

Deen, Robert G.; Pariser, Oleg; Yeates, Matthew C.; Lee, Hyun H.; Lorre, Jean

2013-01-01

286

Semiconductors: In Situ Processing of Photovoltaic Devices  

NASA Technical Reports Server (NTRS)

Current proposals for developing an extended human presence on the Moon and Mars increasingly consider the processing of nonterrestrial materials essential for keeping the Earth launch burden reasonable. Utilization of in situ resources for construction of lunar and Mars bases will initially require assessment of resource availability followed by the development of economically acceptable and technically feasible extraction processes. In regard to materials processing and fabrication, the lower gravity level on the Moon (0.125 g) and Mars (0.367 g) will dramatically change the presently accepted hierarchy of materials in terms of specific properties, a factor that must be understood and exploited. Furthermore, significant changes are expected in the behavior of liquid materials during processing. In casting, for example, mold filling and associated solidification processes have to be reevaluated. Finally, microstructural development, and therefore material properties, presently being documented through ongoing research in microgravity science and applications, need to be understood and scaled to the reduced gravity environments.

Curreri, Peter A.

1998-01-01

287

High resolution in situ ultrasonic corrosion monitor  

DOEpatents

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.

Grossman, R.J.

1984-01-10

288

High resolution in situ ultrasonic corrosion monitor  

DOEpatents

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.

Grossman, Robert J. (Schenectady, NY)

1985-01-01

289

IN SITU URANIUM STABILIZATION BY MICROBIAL METABOLITES  

SciTech Connect

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.

Turick, C; Anna Knox, A; Chad L Leverette,C; Yianne Kritzas, Y

2006-11-29

290

In-situ continuous water monitoring system  

DOEpatents

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.

Thompson, Cyril V. (Knoxville, TN); Wise, Marcus B. (Kingston, TN)

1998-01-01

291

PERFORMANCE CONFIRMATION IN-SITU INSTRUMENTATION  

SciTech Connect

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.

N.T. Raczka

2000-05-23

292

Comparisons of Remote And In-situ CME Features  

NASA Astrophysics Data System (ADS)

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.

Reinard, Alysha; Mulligan, T.; Lynch, B.

2011-05-01

293

DNA/DNA in situ hybridization with enzyme linked probes  

SciTech Connect

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.

Grillo, S.; Mosher, M.; Charles, P.; Henry, S.; Taub, F.

1987-05-01

294

A Deep-Sea Mass Spectrometer Instrument for Long-Term, In Situ Biogeochemical Monitoring  

NASA Astrophysics Data System (ADS)

Mass spectrometry has been a major analytical tool for more than 100 years, but it has rarely been used to monitor the environment in situ. Furthermore, a deep-water instrument is even more challenging due to a lack of an effective membrane-introduction interface and an efficient high-vacuum system that will work remotely for long periods at very high pressure. Being able to solve these problems could greatly improve scientific work that requires long-term monitoring of the environment (geology, biology, oceanography). Traditional deep-water sampling methods usually involve the collection of water samples and delivery to a laboratory for analysis. This approach can result in degradation of sample quality over time and provide inaccurate results, but mostly, this approach limits a remote, in situ monitoring capability. In situ measurements by an underwater mass spectrometer can eliminate many problems intrinsic to traditional sampling methods and provide data with temporal resolutions that are difficult to obtain by other means. High sensitivity and the ability to simultaneously measure multiple species (e.g. hydrogen, helium, methane, oxygen, H2S or CO2) with the promise of isotopic resolution are its major features. We have developed an underwater mass spectrometer instrument for the in situ study of dissolved gases for six months to a year at up to 3000 m water depth, using battery power. This oceanographic instrument should eventually allow the measurement of dissolved gases and volatile organic compounds in a variety of ocean environments (cold seeps on the continental margins, deep-sea hydrothermal vents, submarine groundwater discharge and pollution in coastal areas).

Bossuyt, A.; McMurtry, G. M.

2004-12-01

295

In situ search for organics by gas chromatography analysis: new derivatization / thermochemolysis approach  

NASA Astrophysics Data System (ADS)

Many organic molecules are present in interstellar clouds and might be carried to the early Earth by comets and meteorites during the heavy bombardment phase in the first few hundred million years of the solar system. It has been suggested that extraterrestrial organic material may well represent an important part of the organic material available for the origin of life. Until samples, brought by future space missions, are available on Earth, in situ measurements are one of the way to get unaltered and non-contaminated samples for analysis. The analytical technique has to be robust, sensitive and non-specific due to the large scope of targets molecules. The only currently flight qualified technique of analysis of organic molecules in space is gas chromatography (Viking, Cassini-Huygens, SAM-MSL, COSAC-Rosetta). The main objective of this work is to present a new approach with multi step analysis using derivatisation and thermochemolysis reagents for a one pot in situ analysis of volatile and refractory organics in surface or sub-surface samples (Mars, comets).Indeed, no single technology enables to identify all organic compounds because naturally occurring molecules have different polarities, molecular weights, being extractible or recalcitrant, bonded trapped or adsorbed on minerals. Thus, we propose to wider the scope of chemical reagent already validated for in situ wet chemistry such as MTBSTFA (Rodier et al. 2001, 2002), DMF-DMA (Rodier et al. 2002), or TMAH (Rodier et al, 2005, Geffroy-Rodier et al; 2009) to analyze enantiomers of amino acids, carbohydrates and lipids in a one pot several steps sub system using a multi reagent and multi step approach. Thus using a new derivatizing agent, we successfully identified twenty one amino acids including twelve of the twenty proteinic amino acids without inhibiting following multi step thermochemolysis. *Geffroy-Rodier C, Grasset L, Sternberg R. Buch A. Amblès A. (2009) Thermochemolysis in search for organics in extraterrestrial environments, Journal of Applied Pyrolysis 85: 454-459. *Rodier C, Sternberg R, Raulin F, Vidal-Madjar C (2001). In situ detection of organic molecules in extraterrestrial environment by gas chromatography / mass spectrometry. Journal of Chromatography A 915: 199-207. *Rodier C, Laurent C, Szopa C. Sternberg R, Raulin F (2002) Chirality and the origin of life: in situ enantiomeric separation for future space missions, Chirality 14: 527-532. *Rodier C. Sternberg R, Szopa C, Buch A, Cabane M and Raulin F (2005) Search for organics in extraterrestrial environments by in situ gas chromatography analysis. Advances in Space Research 36: 195-200. This work has been funded by CNES

Geffroy, Claude; Buch, Arnaud; David, Marc; Aissat, Lyes; El Mufleh, Amel; Papot, S.; Sternberg, Robert

296

In Situ Analysis of Nitrifying Biofilms as Determined by In Situ Hybridization and the Use of Microelectrodes  

Microsoft Academic Search

We investigated the in situ spatial organization of ammonia-oxidizing and nitrite-oxidizing bacteria in do- mestic wastewater biofilms and autotrophic nitrifying biofilms by using microsensors and fluorescent in situ hybridization (FISH) performed with 16S rRNA-targeted oligonucleotide probes. The combination of these tech- niques made it possible to relate in situ microbial activity directly to the occurrence of nitrifying bacterial populations. In

SATOSHI OKABE; HISASHI SATOH; YOSHIMASA WATANABE

1999-01-01

297

In situ radiation measurements at the former Soviet Nuclear Test Site  

SciTech Connect

A team from the Remote Sensing Laboratory conducted a series of in situ radiological measurements at the former Soviet Nuclear Test Site near Semipalatinsk, Kazakhstan, during the period of July 21-30, 1994. The survey team measured the terrestrial gamma radiation at selected areas on the site to determine the levels of natural and man-made radiation. The survey was part of a cooperative effort between the United States team and teams of radiation scientists from the National Nuclear Center of the Republic of Kazakhstan and the V.G. Khlopin Radium Institute in St. Petersburg, Russia. In addition to in situ radiation measurements made by the United States and Russian teams, soil samples were collected and analyzed by the Russian and Kazakhstani teams. All teams conducted their measurements at ten locations within the test site. The United States team also made a number of additional measurements to locate and verify the positions of three potential fallout plumes containing plutonium contamination from nonnuclear tests. In addition, the United States team made several measurements in Kurchatov City, the housing area used by personnel and their families who work(ed) at the test sites. Comparisons between the United States and Russian in situ measurements and the soil sample results are presented as well as comparisons with a Soviet aerial survey conducted in 1990-1991. The agreement between the different types of measurements made by all three countries was quite good.

Tipton, W.J.

1996-06-01

298

Assessment of the use of prompt gamma emission for proton therapy range verification  

E-print Network

PURPOSE: Prompt gamma rays emitted from proton-nucleus interactions in tissue present a promising non-invasive, in situ means of monitoring proton beam based radiotherapy. This study investigates the fluence and energy ...

Styczynski, John R

2009-01-01

299

Emerging issues after the recognition of in situ follicular lymphoma.  

PubMed

This article reviews knowledge derived from the introduction of the concept of in situ follicular lymphoma (FL). The following questions are addressed: (1) How should in situ lymphomas be defined and diagnosed? (2) Is in situ lymphoma an early step of lymphomagenesis? (3) Is the concept of early neoplasia applicable to the lymphoma setting? (4) How should patients with in situ lymphoma be managed? The commonly used term of in situ FL, also called FL in situ (FLIS), has been adopted to define a B-cell lymphoid neoplasia with an intrafollicular growth pattern. The neoplastic B cells are localized within the germinal center, without invasion of surrounding structures. Pathological diagnosis requires recognizing strong immunostaining of BCL2 and CD10 by neoplastic B cells inside the affected follicles. Fluorescence in situ hybridization (FISH) analysis for t(14;18) is mandatory in doubtful cases in which immunohistochemistry data are ambiguous. In situ FL is probably the earliest stage of development of FL, while the concept of "early" lymphoma is applicable when minimal disease extends beyond the boundaries of the follicular compartment. From a clinical point of view, in situ FL has an uncertain clinical behavior and unknown risk to progression to overt lymphoma. How to approach and monitor patients with in situ FL is currently uncertain. An asymptomatic patient with stage 1 in situ FL requires the same treatment plan as an asymptomatic patient with stage 1 conventional FL. For patients with concomitant overt malignancy, therapy must be applied according to the malignant counterpart. PMID:23713483

Carbone, Antonino; Gloghini, Annunziata

2014-03-01

300

IN-SITU TRITIUM BETA DETECTOR  

SciTech Connect

The objectives of this three-phase project were to design, develop, and demonstrate a monitoring system capable of detecting and quantifying tritium in situ in ground and surface waters, and in water from effluent lines prior to discharge into public waterways. The tritium detection system design is based on measurement of the low energy beta radiation from the radioactive decay of tritium using a special form of scintillating optical fiber directly in contact with the water to be measured. The system consists of the immersible sensor module containing the optical fiber, and an electronics package, connected by an umbilical cable. The system can be permanently installed for routine water monitoring in wells or process or effluent lines, or can be moved from one location to another for survey use. The electronics will read out tritium activity directly in units of pico Curies per liter, with straightforward calibration. In Phase 1 of the project, we characterized the sensitivity of fluor-doped plastic optical fiber to tritium beta radiation. In addition, we characterized the performance of photomultiplier tubes needed for the system. In parallel with this work, we defined the functional requirements, target specifications, and system configuration for an in situ tritium beta detector that would use the fluor-doped fibers as primary sensors of tritium concentration in water. The major conclusions from the characterization work are: A polystyrene optical fiber with fluor dopant concentration of 2% gave best performance. This fiber had the highest dopant concentration of any fibers tested. Stability may be a problem. The fibers exposed to a 22-day soak in 120 F water experienced a 10x reduction in sensitivity. It is not known whether this was due to the build up of a deposit (a potentially reversible effect) or an irreversible process such as leaching of the scintillating dye. Based on the results achieved, it is premature to initiate Phase 2 and commit to a prototype design for construction and test. Significant improvements must be made in fluor-doped fiber performance in order to use the method for in situ monitoring to verify compliance with current EPA drinking water standards. Additional Phase 1 fiber development work should be performed to increase the fluor dopant concentration above 2% until the self-absorption limit is observed. Continued fiber optimization work is expected to improve the sensitivity limits, and will enable application of the detector to verify compliance with the US EPA drinking water standard of 20,000 pico Curies per liter. However, if the need for monitoring higher levels of tritium in water at concentrations greater than 200,000 pico Curies per liter is justified, then prototype development and testing could proceed either as a Phase 2 stand-alone effort or in parallel with continued Phase 1 development work.

J.W. Berthold; L.A. Jeffers

1998-04-15

301

Additive manufacturing for in situ repair of osteochondral defects  

Microsoft Academic Search

Tissue engineering holds great promise for injury repair and replacement of defective body parts. While a number of techniques exist for creating living biological constructs in vitro, none have been demonstrated for in situ repair. Using novel geometric feedback-based approaches and through development of appropriate printing-material combinations, we demonstrate the in situ repair of both chondral and osteochondral defects that

Daniel L. Cohen; Jeffrey I. Lipton; Lawrence J. Bonassar; Hod Lipson

2010-01-01

302

Electromechanical instabilities of thermoplastics: Theory and in situ observation  

E-print Network

Electromechanical instabilities of thermoplastics: Theory and in situ observation Qiming Wang://apl.aip.org/about/rights_and_permissions #12;Electromechanical instabilities of thermoplastics: Theory and in situ observation Qiming Wang,1 online 5 October 2012) Thermoplastics under voltages are used in diverse applications ranging from

Zhao, Xuanhe

303

Microstructural and mechanical characteristics of in situ metal matrix composites  

Microsoft Academic Search

During the past decade, considerable research effort has been directed towards the development of in situ metal matrix composites (MMCs), in which the reinforcements are formed in situ by exothermal reactions between elements or between elements and compounds. Using this approach, MMCs with a wide range of matrix materials (including aluminum, titanium, copper, nickel and iron), and second-phase particles (including

S. C Tjong; Z. Y Ma

2000-01-01

304

In situ monitoring of liquid phase electroepitaxial growth  

NASA Technical Reports Server (NTRS)

In situ monitoring of the layer thickness during liquid phase electroepitaxy (LPEE) was achieved with a submicron resolution through precise resistance measurements. The new approach to the study and control of LPEE was applied to growth of undoped and Ge-doped GaAs layers. The in situ determined growth kinetics was found to be in excellent agreement with theory.

Okamoto, A.; Isozumi, S.; Lagowski, J.; Gatos, H. C.

1982-01-01

305

An overview of in situ waste treatment technologies  

SciTech Connect

In situ technologies are becoming an attractive remedial alternative for eliminating environmental problems. In situ treatments typically reduce risks and costs associated with retrieving, packaging, and storing or disposing-waste and are generally preferred over ex situ treatments. Each in situ technology has specific applications, and, in order to provide the most economical and practical solution to a waste problem, these applications must be understood. This paper presents an overview of thirty different in situ remedial technologies for buried wastes or contaminated soil areas. The objective of this paper is to familiarize those involved in waste remediation activities with available and emerging in situ technologies so that they may consider these options in the remediation of hazardous and/or radioactive waste sites. Several types of in situ technologies are discussed, including biological treatments, containment technologies, physical/chemical treatments, solidification/stabilization technologies, and thermal treatments. Each category of in situ technology is briefly examined in this paper. Specific treatments belonging to these categories are also reviewed. Much of the information on in situ treatment technologies in this paper was obtained directly from vendors and universities and this information has not been verified.

Walker, S.; Hyde, R.A.; Piper, R.B.; Roy, M.W.

1992-08-01

306

An overview of in situ waste treatment technologies  

SciTech Connect

In situ technologies are becoming an attractive remedial alternative for eliminating environmental problems. In situ treatments typically reduce risks and costs associated with retrieving, packaging, and storing or disposing-waste and are generally preferred over ex situ treatments. Each in situ technology has specific applications, and, in order to provide the most economical and practical solution to a waste problem, these applications must be understood. This paper presents an overview of thirty different in situ remedial technologies for buried wastes or contaminated soil areas. The objective of this paper is to familiarize those involved in waste remediation activities with available and emerging in situ technologies so that they may consider these options in the remediation of hazardous and/or radioactive waste sites. Several types of in situ technologies are discussed, including biological treatments, containment technologies, physical/chemical treatments, solidification/stabilization technologies, and thermal treatments. Each category of in situ technology is briefly examined in this paper. Specific treatments belonging to these categories are also reviewed. Much of the information on in situ treatment technologies in this paper was obtained directly from vendors and universities and this information has not been verified.

Walker, S.; Hyde, R.A.; Piper, R.B.; Roy, M.W.

1992-01-01

307

In-Situ Resource Utilization (ISRU) Capability Roadmap Progress Review  

NASA Technical Reports Server (NTRS)

A progress review on In-Situ Resource Utilization (ISRU) capability is presented. The topics include: 1) In-Situ Resource Utilization (ISRU) Capability Roadmap: Level 1; 2) ISRU Emphasized Architecture Overview; 3) ISRU Capability Elements: Level 2 and below; and 4) ISRU Capability Roadmap Wrap-up.

Sanders, Gerald B.; Duke, Michael

2005-01-01

308

In situ tensile fracture toughness of surficial cohesive marine sediments  

E-print Network

ORIGINAL In situ tensile fracture toughness of surficial cohesive marine sediments Bruce D. Johnson the first in situ measure- ments of tensile fracture toughness, KIC, of soft, surficial, cohesive marine of magnitude lower than for the muddy sediments, and reflects the lack of cohesion/adhesion. A comparison

Jumars, Pete

309

Some implications of in situ uranium mining technology development  

SciTech Connect

A technology assessment was initiated in March 1979 of the in-situ uranium mining technology. This report explores the impediments to development and deployment of this technology and evaluates the environmental impacts of a generic in-situ facility. The report is divided into the following sections: introduction, technology description, physical environment, institutional and socioeconomic environment, impact assessment, impediments, and conclusions. (DLC)

Cowan, C.E.; Parkhurst, M.A.; Cole, R.J.; Keller, D.; Mellinger, P.J.; Wallace, R.W.

1980-09-01

310

ABIOTIC IN SITU TECHNOLOGIES FOR GROUNDWATER REMEDIATION CONFERENCE: PROCEEDINGS  

EPA Science Inventory

The USEPA conference on Abiotic In Situ Technologies for Groundwater Remediation was held in Dallas, TX, 8/31-9/2/99. The goal of the meeting was to disseminate current information on abiotic in situ groundwater treatment echnologies. Although much information is being provided a...

311

Successful Treatment of Lower Eyelid Melanoma in Situ  

PubMed Central

Summary: We present a brief literature review of the topical immune-modulating medication Imiquimod. The treatment of periorbital melanoma in situ typically requires surgical resection. Here we discuss a case of lower eyelid melanoma in situ successfully treated non-operatively with Imiquimod.

Yuan, Joyce; Koh, Justin; Miller, Timothy A.

2014-01-01

312

Determining In-Situ Stress Profiles From Logs.  

E-print Network

study. #12;18 SPE 90070 Shahab D. Mohaghegh Methodology Neural Networks were used to develop an in1 Determining In-Situ Stress Profiles From Logs. Shahab D. Mohaghegh West Virginia University regarding in-situ stress. An important factor in designing successful hydraulic fractures. #12;4 SPE 90070

Mohaghegh, Shahab

313

Diagnostic tools for unbiased in situ target strength estimation  

Microsoft Academic Search

In situ target strength (TS) is theoretically the optimal measure to scale echo-integration values to fish density. In practice, in situ TS is often biased. The number of fish per sample volume (Nv) has been used to set a threshold density to reduce the bias attributable to multiple targets. However, order of magnitude differences in the Nv threshold have been

Stéphane Gauthier; George A. Rose

2001-01-01

314

Metabolic indicators for detecting in situ anaerobic alkylbenzene degradation  

Microsoft Academic Search

Monitoring programs for intrinsic bioremediation of fuel hydrocarbonsrequire indicators that can convincingly demonstrate in situ metabolism. In this evaluation of potential indicators of in situ anaerobic alkylbenzene metabolism, laboratory and field data are reviewed for two classes of aromatic acids: (i) benzylsuccinate, E-phenylitaconate, and their methyl homologs, and (ii) benzoate, and methyl-, dimethyl-, and trimethylbenzoates. The review includes previously unpublished

Harry R. Beller

2000-01-01

315

Denitrification in?situ of groundwaters with solid carbon matter  

Microsoft Academic Search

We propose a denitrification process of in?situ treatment. The system has a central drilling from which water is partly pumped out and distributed, the other part is sent in reactors filled up with a mixture of straw and maërl and then reinjected in aquiferous through the soil. Five series of experimentation in?situ have been made. A fall down of the

F. Boussaid; G. Martin; J. Morvan; J. J. Collin; A. Landreau; H. Talbo

1988-01-01

316

Polypropylene carbon nanotube composites by in situ polymerization  

Microsoft Academic Search

The preparation of isotactic polypropylene nanocomposites filled with crude, purified and oxidized multi-walled carbon nanotubes (MWCNTs) was accomplished by polymerization of propylene with a metallocene\\/methylaluminoxane (MAO) catalyst and in situ coating. A good interfacial adhesion between the matrix and the filler is crucial for the successful preparation of nanocomposites; therefore, the polymerizations were performed with a new in situ coating

Andreas Funck; Walter Kaminsky

2007-01-01

317

In Situ Colloid Mobilization in Hanford Sediments under  

E-print Network

In Situ Colloid Mobilization in Hanford Sediments under Unsaturated Transient Flow Conditions of radioactive wastes at the Hanford site, Washington State. In this study, column experiments were conducted to examine the effect of irrigation schedule on releases of in situ colloids from two Hanford sediments

Perfect, Ed

318

A mass spectrometry primer for mass spectrometry imaging  

PubMed Central

Mass spectrometry imaging (MSI), a rapidly growing subfield of chemical imaging, employs mass spectrometry (MS) technologies to create single- and multi-dimensional localization maps for a variety of atoms and molecules. Complimentary to other imaging approaches, MSI provides high chemical specificity and broad analyte coverage. This powerful analytical toolset is capable of measuring the distribution of many classes of inorganics, metabolites, proteins and pharmaceuticals in chemically and structurally complex biological specimens in vivo, in vitro, and in situ. The MSI approaches highlighted in this Methods in Molecular Biology volume provide flexibility of detection, characterization, and identification of multiple known and unknown analytes. The goal of this chapter is to introduce investigators who may be unfamiliar with MS to the basic principles of the mass spectrometric approaches as used in MSI. In addition to guidelines for choosing the most suitable MSI method for specific investigations, cross-references are provided to the chapters in this volume that describe the appropriate experimental protocols. PMID:20680583

Rubakhin, Stanislav S.; Sweedler, Jonathan V.

2011-01-01

319

In-situ X-ray Absorption Spectroscopy of Supported Ru Catalysts in the Aqueous Phase  

SciTech Connect

The size of supported Ru metal particles on various supports was monitored by in situ X-ray absorption spectroscopy under aqueous phase conditions typical of biomass conversion reactions. In particular, Ru/{gamma}-Al{sub 2}O{sub 3}, Ru/C, Ru/TiO{sub 2}, and Ru/SiO{sub 2} were evaluated at the Ru K edge at 473 K in neutral water and 0.4 M NaOH. The as-prepared samples exposed to air contained oxidized Ru that was subsequently reduced by H{sub 2}-saturated water solution. Significant growth of the metal particles was observed on the Ru/{gamma}-Al{sub 2}O{sub 3} and Ru/SiO{sub 2} samples during the aqueous treatments, whereas the Ru/TiO{sub 2} and Ru/C samples were quite stable under the conditions used here. Results from post-treatment X-ray diffraction and surface area analysis revealed major structural changes of the alumina and silica supports. The structural stability of the carbon and titania account for the lack of metal particle growth on those supports. Because a reference Pt/C catalyst revealed metal particle growth under the same conditions, the results for the Ru/C cannot be generalized to other carbon-supported catalysts and underscores the importance of in situ characterization for heterogeneous catalysts in the aqueous phase.

Ketchie,W.; Maris, E.; Davis, R.

2007-01-01

320

An In Situ Radiological Survey of Three Canyons at the Los Alamos National Laboratory  

SciTech Connect

An in situ radiological survey of Mortandad, Ten Site, and DP Canyons at the Los Alamos National Laboratory was conducted during August 19-30, 1996. The purpose of this survey was to measure the quantities of radionuclides that remain in the canyons from past laboratory operations. A total of 65 in situ measurements were conducted using high-resolution gamma radiation detectors at 1 meter above the ground. The measurements were obtained in the streambeds of the canyons beginning near the water-release points at the laboratories and extending to the ends of the canyons. Three man-made gamma-emitting radionuclides were detected in the canyons: americium-241 ({sup 241}Am), cesium-137 ({sup 137}Cs), and cobalt-60 ({sup 60}Co). Estimated contamination levels ranged from 13.3-290.4 picocuries per gram (pCi/g)for {sup 241}Am, 4.4-327.8 pCi/g for {sup 137}Cs, and 0.4-2.6 pCi/g for {sup 60}Co.

R.J. Maurer

1999-06-01

321

Imaging tree root systems in situ  

NASA Astrophysics Data System (ADS)

Predictions of global energy use in this century suggest a continued increase in carbon emissions and rising concentrations of carbon dioxide (CO2) in the atmosphere. This represents a serious environmental problem and contributes significantly to greenhouse gases that affect global warming. Terrestrial ecosystems are a huge natural biological scrubber for CO2 currently sequestering, directly from the atmosphere, about 25% (approximately 2 GtC) of the 7.4 Gt of anthropogenic carbon emitted annually into the atmosphere. The major carbon pathways into soil are through plant litter and roots. Presently, there are no means by which root morphology, distribution, and mass can be measured without serious sampling artifacts that alter these properties. The current methods are destructive and labor intensive. Preliminary results using a high frequency, 1.5 Ghz, impulse Ground Penetrating Radar (GPR) for nondestructive imaging of tree root systems in situ are presented. The 3D reconstructed image is used to assess root morphology and dimensions. The constraints, limitations, and potential solutions for using GPR for tree root systems imaging and analysis are discussed.

Wielopolski, Lucian; Hendrey, George; Daniels, Jeffrey J.; McGuigan, Michael

2000-04-01

322

Enhancing in situ bioremediation with pneumatic fracturing  

SciTech Connect

A major technical obstacle affecting the application of in situ bioremediation is the effective distribution of nutrients to the subsurface media. Pneumatic fracturing can increase the permeability of subsurface formations through the injection of high pressure air to create horizontal fracture planes, thus enhancing macroscale mass-transfer processes. Pneumatic fracturing technology was demonstrated at two field sites at Tinker Air Force Base, Oklahoma City, Oklahoma. Tests were performed to increase the permeability for more effective bioventing, and evaluated the potential to increase permeability and recovery of free product in low-permeability soils consisting of fine-grain silts, clays, and sedimentary rock. Pneumatic fracturing significantly improved formation permeability by enhancing secondary permeability and by promoting removal of excess soil moisture form the unsaturated zone. Postfracture airflows were 500% to 1,700% higher than prefracture airflows for specific fractured intervals in the formation. This corresponds to an average prefracturing permeability of 0.017 darcy, increasing to an average of 0.32 darcy after fracturing. Pneumatic fracturing also increased free-product recovery rates of number 2 fuel from an average of 587 L (155 gal) per month before fracturing to 1,647 L (435 gal) per month after fracturing.

Anderson, D.B.; Peyton, B.M. [Battelle Pacific Northwest, Richland, WA (United States); Liskowitz, J.J.; Fitzgerald, C.D. [Accutech Remedial Systems, Keyport, NJ (United States); Schuring, J.R. [New Jersey Inst. of Tech., Newark, NJ (United States). Dept. of Chemical Engineering, Chemistry, and Environmental Science

1995-12-31

323

In situ analysis of the martian soil  

NASA Astrophysics Data System (ADS)

Mars is presently the most likely planet on which there is a possibility of finding extinct and/or extant life. The next exploratory missions to Mars will focus on key organic molecules such as carboxylic and amino acids. In the frame of the Sample Analysis on Mars (SAM) GC/MS-based experiment aiming at performing in situ chemical analysis of the Martian soil, an automated extraction process coupled to chemical derivatization is under development. The extraction efficiency of various organic solvents has been tested (and compared to that of water), first on standard soil samples and then, on Martian soil analogues such as the Akatama desert (Chili) soil. It was shown that propanol is the best solvent, allowing high extraction yields for both amino and carboxylic acids with space compatible extraction time (15 to 30 min) when the extraction procedure is assisted by sonication. A highly sensititive and quantitative single-step derivatization reaction using as N-(tert-butyldimethylsilyl)-trifluoroacétanamide (MTBSTFA) as silylation agent was then used, prior to GC/MS analysis. The extraction and the derivatization process will take place in an automated miniaturized reactor, which is currently under investigation.

Buch, A.; Sternberg, R.; Meunier, D.; Marchetti, C.; Raulin, F.

2003-04-01

324

Visualizing T Cell Migration in situ  

PubMed Central

Mounting a protective immune response is critically dependent on the orchestrated movement of cells within lymphoid tissues. The structure of secondary lymphoid organs regulates immune responses by promoting optimal cell–cell and cell–extracellular matrix interactions. Naïve T cells are initially activated by antigen presenting cells in secondary lymphoid organs. Following priming, effector T cells migrate to the site of infection to exert their functions. Majority of the effector cells die while a small population of antigen-specific T cells persists as memory cells in distinct anatomical locations. The persistence and location of memory cells in lymphoid and non-lymphoid tissues is critical to protect the host from re-infection. The localization of memory T cells is carefully regulated by several factors including the highly organized secondary lymphoid structure, the cellular expression of chemokine receptors and compartmentalized secretion of their cognate ligands. This balance between the anatomy and the ordered expression of cell surface and soluble proteins regulates the subtle choreography of T cell migration. In recent years, our understanding of cellular dynamics of T cells has been advanced by the development of new imaging techniques allowing in situ visualization of T cell responses. Here, we review the past and more recent studies that have utilized sophisticated imaging technologies to investigate the migration dynamics of naïve, effector, and memory T cells. PMID:25120547

Benechet, Alexandre P.; Menon, Manisha; Khanna, Kamal M.

2014-01-01

325

IN-SITU MINING OF PHOSPHATE ORES  

SciTech Connect

Presently the mining of Florida phosphate requires the movement of over a 100-ton of materials (overburden, sand, clay) for every ton of phosphate concentrate recovered. Not only is this energy intensive, but it also causes significant stress on the environment. In 2003, the Department of Energy solicited ideas for innovative mining ideas that could significantly improve the efficiency of mining. An award was made to the University of Florida Engineering Research Center to evaluate the in situ mining of phosphates using an aqueous CO{sub 2} solution. Tests were carried out in a 15.2 cm (6-inch) diameter column, 1.83 meter (6 feet) long at pressures up to 117.2 kg/cm{sup 2} (40 psi). Results to date demonstrate that initially the MgO is leached from the ore and then the phosphate. While the tests are continuing, so far they have not demonstrated P{sub 2}O{sub 5} concentrations that are economically attractive.

H. El-Shall; R. Stana; A. El-Midany; S. Malekzadah

2004-12-17

326

In situ observations of Io torus plasma  

NASA Technical Reports Server (NTRS)

The physical properties of the Io plasma formation deduced from in situ observations are described. The torus plasma is characterized by spatially distinct regions with steep gradients in plasma parameters between them. The innermost region has a cool plasma which collapses toward the centrifugal equator and gives rise to a distinctive localized concentration of plasma well inside of Io's orbit. The next region has a warm plasma which includes the L-shell of Io and is the presumed injection region of the plasma. Other regions, known as the plasma ledge and ramp, are described. The changes in plasma characteristics are accounted for by centrifugally driven flux tube interchange diffusion to provide radial mass transport. The ramp is shown to result from impoundment of the plasma by the inner edge of the energetic particle population. It is also shown how the power required to excite the ultraviolet emissions of the torus and the Jovian aurora determines the rate at which new plasma is fed into the torus.

Sullivan, J. D.; Siscoe, G. L.

1982-01-01

327

In situ dissolution testing using potentiometric sensors.  

PubMed

Potentiometric sensors can be used to determine the amount of API dissolved in the dissolution medium in function of time by measuring directly in the dissolution vessel of a Paddle (USP type 2) and Basket (USP type 1) apparatus. The prototype potentiometric sensor instrumentation showed very promising results for a selection of APIs with different physico-chemical properties. The applicability, benefits and limitations of the prototype were explored. The applicability of the measurement technique strongly depends on the log(P) of the API. Here, it is shown that measurements can easily be performed for APIs with a log(P)>4. Electrode performance however decreases with decreasing logP of the APIs due to decreased drug selectivity in comparison to the excipients and ionic strength of the applied dissolution medium. The potentiometric sensors are shown to be insensitive towards undissolved particles and air bubbles as opposed to UV spectrometric measurement where these can lead to severe light scattering. For the tested APIs, the obtained dissolution profiles are very reproducible and show a low variation compared to the measurements using manual sampling and UV or HPLC analysis. The measurements demonstrate that potentiometric sensors are a very promising technology that can become a standard for in situ dissolution measurements. PMID:18539443

Peeters, Karl; De Maesschalck, Roy; Bohets, Hugo; Vanhoutte, Koen; Nagels, Luc

2008-08-01

328

In Situ and Satellite Measured Temperature Comparability  

NASA Technical Reports Server (NTRS)

Following the International Geophysical Year in the late 1950's, small meteorological rockets caught the interest of scientists as a potentially inexpensive method to obtain meteorological information (density, temperature, wind) above balloon-borne radiosonde altitudes. These small rocketsondes have served many important observational roles in terms of studies conducted of atmospheric structure and processes, enabling many new ideas about the atmosphere to emerge. Although no longer manufactured a small residual inventory of meteorological rocketsondes exist for specific research projects. The value of data from meteorological rocketsondes is without question but with their disappearance data from many different satellites are filling the need, some able to resolve high-altitude temperatures quite well. However, the rocketsonde vertical profile is more localized to the launch site whereas satellites move several kilometers per second. The objective of this presentation is to compare in situ temperature data with remotely measured/retrieved temperature data. There have been a number of U.S. conducted missions utilizing the passive falling sphere data that we use to verify the comparability of retrieved temperatures from these satellites. Missions, some as early as 1991, were conducted in polar, equatorial, and mid-latitude locations. An important aspect is that a single satellite profile compared to a falling sphere profile often does not agree while high density satellite measurements when averaged over an area near the rocketsonde data area seems to be in better agreement. Radiosonde temperature data are used in the analysis when appropriate

Schmidlin, F. J.; Goldberg, R. A.; Bedrick, Mary; Rose, R. Lynn

2011-01-01

329

In situ containment and stabilization of buried waste  

SciTech Connect

The objective of the project was to develop, demonstrate and implement advanced grouting materials for the in-situ installation of impermeable, durable subsurface barriers and caps around waste sites and for the in-situ stabilization of contaminated soils. Specifically, the work was aimed at remediation of the Chemical Waste (CWL) and Mixed Waste Landfills (MWL) at Sandia National Laboratories (SNL) as part of the Mixed Waste Landfill Integrated Demonstration (MWLID). This report documents this project, which was conducted in two subtasks. These were (1) Capping and Barrier Grouts, and (2) In-situ Stabilization of Contaminated Soils. Subtask 1 examined materials and placement methods for in-situ containment of contaminated sites by subsurface barriers and surface caps. In Subtask 2 materials and techniques were evaluated for in-situ chemical stabilization of chromium in soil.

Allan, M.L.; Kukacka, L.E.; Heiser, J.H.

1992-11-01

330

Polyamide 66 microspheres metallised with in situ synthesised gold nanoparticles for a catalytic application.  

PubMed

A simple concept is proposed to metallise polyamide 66 (PA66) spherulite structures with in situ synthesised gold nanoparticles (Au NPs) using a wet chemical method. This cost-effective approach, applied to produce a PA66/Au NP hybrid material, offers the advantages of controlling the nanoparticle size, the size distribution and the organic-inorganic interactions. These are the key factors that have to be controlled to construct consistent Au nanostructures which are essential for producing the catalytic activities of interest. The hybrid materials obtained are characterised by means of scanning electron microscopy, transmission electron microscopy, attenuated total reflection-Fourier transform infrared spectrometry and X-ray diffraction spectrometry. The results show that PA66 microspheres obtained via the crystallisation process are coated with Au NPs of 13 nm in size. It was found that controlling the metal coordination is the key parameter to template the Au NPs on the spherulite surfaces. The preparation processes and the key factors leading to the formation of PA66 spherulites coated with Au NPs are discussed. Moreover, the efficiency of the coated spherulites as a potential catalyst is proved by demonstrating the reduction of methylene blue via UV-visible spectrometry. PMID:22401661

Cheval, Nicolas; Gindy, Nabil; Flowkes, Clifford; Fahmi, Amir

2012-01-01

331

Underwater mass spectrometers for in situ chemical analysis of the hydrosphere.  

PubMed

Underwater mass spectrometry systems can be used for direct in situ detection of volatile organic compounds and dissolved gases in oceans, lakes, rivers and waste-water streams. In this work we describe the design and operation of (1) a linear quadrupole mass filter and (2) a quadrupole ion trap mass spectrometer interfaced, in each case, with a membrane introduction/fluid control system and packaged for underwater operation. These mass spectrometry systems can operate autonomously, or under user control via a wireless rf link. Detection limits for each system were determined in the laboratory using pure solutions. The quadrupole mass filter system provides detection limits in the 1-5 ppb range with an upper mass limit of 100 amu. Its power requirement is approximately 95 Watts. The ion trap system has detection limits well below 1 ppb, an upper mass limit of 650 amu and MS/MS capability. Its power consumption is on the order of 150 Watts. The present membrane limits analysis to non-polar compounds (<300 amu) with analysis cycles of 5-15 minutes. Deployments of both types of instruments are described, along with a discussion of the challenges associated with in-water mass spectrometry and descriptions of alternative in-water mass spectrometer configurations. PMID:11401158

Short, R T; Fries, D P; Kerr, M L; Lembke, C E; Toler, S K; Wenner, P G; Byrne, R H

2001-06-01

332

Time-Resolved Data Acquisition for In Situ Subsurface Planetary Geochemistry  

NASA Technical Reports Server (NTRS)

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 geochemistry of planetary bodies in situ. All previous NASA planetary science missions, that used neutron and/or gamma-ray spectroscopy instruments, have relied on a constant neutron source 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.

Bodnarik, Julia Gates; Burger, Dan M.; Burger, Arnold; Evans, Larry G.; Parsons, Ann M.; Starr, Richard D.; Stassun, Keivan G.

2012-01-01

333

in situ Calcite Precipitation for Contaminant Immobilization  

SciTech Connect

in situ Calcite Precipitation for Contaminant Immobilization Yoshiko Fujita (Yoshiko.fujita@inl.gov) (Idaho National Laboratory, Idaho Falls, Idaho, USA) Robert W. Smith (University of Idaho-Idaho Falls, Idaho Falls, Idaho, USA) Subsurface radionuclide and trace metal contaminants throughout the U.S. Department of Energy (DOE) complex pose one of DOE’s greatest challenges for long-term stewardship. One promising stabilization mechanism for divalent trace ions, such as the short-lived radionuclide strontium-90, is co-precipitation in calcite. Calcite, a common mineral in the arid western U.S., can form solid solutions with trace metals. The rate of trace metal incorporation is susceptible to manipulation using either abiotic or biotic means. We have previously demonstrated that increasing the calcite precipitation rate by stimulating the activity of urea hydrolyzing microorganisms can result in significantly enhanced Sr uptake. Urea hydrolysis causes the acceleration of calcium carbonate precipitation (and trace metal co-precipitation) by increasing pH and alkalinity, and also by liberating the reactive cations from the aquifer matrix via exchange reactions involving the ammonium ion derived from urea: H2NCONH2 + 3H2O ? 2NH4+ + HCO3- + OH- urea hydrolysis >X:2Ca + 2NH4+ ? 2>X:NH4 + Ca2+ ion exchange Ca2+ + HCO3- + OH- ? CaCO3(s) + H2O calcite precipitation where >X: is a cation exchange site on the aquifer matrix. This contaminant immobilization approach has several attractive features. Urea hydrolysis is catalyzed by the urease enzyme, which is produced by many indigenous subsurface microorganisms. Addition of foreign microbes is unnecessary. In turn the involvement of the native microbes and the consequent in situ generation of reactive components in the aqueous phase (e.g., carbonate and Ca or Sr) can allow dissemination of the reaction over a larger volume and/or farther away from an amendment injection point, as compared to direct addition of the reactants at a well (which can lead to clogging). A final particularly attractive characteristic of this approach is its long-term sustainability; the remediation scheme is geared toward environments that are already saturated with respect to calcite, and in such systems the bulk of any newly precipitated calcite will remain stable once engineered manipulations cease. This means that the co-precipitated contaminants will be effectively sequestered over the long term. We are currently conducting integrated field, laboratory, and computational research to evaluate a) the relationships between urea hydrolysis rate, calcite precipitation rate, and trace metal partitioning under environmentally relevant conditions; and b) the coupling between flow/flux manipulations and calcite precipitate distribution and metal uptake. We are also assessing the application of geophysical and molecular biological tools to monitor the relevant chemical and physical processes. The primary emphasis is on field-scale processes, with the laboratory and modeling activities designed specifically to support the field studies. Field experiments are being conducted in perched water (vadose zone) at the Vadose Zone Research Park (VZRP) at the Idaho National Laboratory; the VZRP provides an uncontaminated setting that is an analog of the 90Sr-contaminated vadose zone at the Idaho Nuclear Technology and Engineering Center. A summary of results to date will be presented.

Yoshiko Fujita; Robert W. Smith

2009-08-01

334

In-Situ Wire Damage Detection System  

NASA Technical Reports Server (NTRS)

An In-Situ Wire Damage Detection System (ISWDDS) has been developed that is capable of detecting damage to a wire insulation, or a wire conductor, or to both. The system will allow for realtime, continuous monitoring of wiring health/integrity and reduce the number of false negatives and false positives while being smaller, lighter in weight, and more robust than current systems. The technology allows for improved safety and significant reduction in maintenance hours for aircraft, space vehicles, satellites, and other critical high-performance wiring systems for industries such as energy production and mining. The integrated ISWDDS is comprised of two main components: (1) a wire with an innermost core conductor, an inner insulation film, a conductive layer or inherently conductive polymer (ICP) covering the inner insulation film, an outermost insulation jacket; and (2) smart connectors and electronics capable of producing and detecting electronic signals, and a central processing unit (CPU) for data collection and analysis. The wire is constructed by applying the inner insulation films to the conductor, followed by the outer insulation jacket. The conductive layer or ICP is on the outer surface of the inner insulation film. One or more wires are connected to the CPU using the smart connectors, and up to 64 wires can be monitored in real-time. The ISWDDS uses time domain reflectometry for damage detection. A fast-risetime pulse is injected into either the core conductor or conductive layer and referenced against the other conductor, producing transmission line behavior. If either conductor is damaged, then the signal is reflected. By knowing the speed of propagation of the pulse, and the time it takes to reflect, one can calculate the distance to and location of the damage.

Williams, Martha; Roberson, Luke; Tate, Lanetra; Smith, Trent; Gibson, Tracy; Medelius, Pedro; Jolley, Scott

2012-01-01

335

Synchronous bilateral neuroendocrine ductal carcinoma in situ.  

PubMed

Neuroendocrine ductal carcinoma in situ (NE-DCIS) is a breast malignancy that has characteristic clinicopathological features and can, therefore, be regarded as a distinct variant of DCIS. The patient was a 54-year-old premenopausal woman with hemorrhagic nipple discharge in her left breast. Magnetic resonance imaging and ultrasound (US) images of the left breast showed mass-like lesions, while concurrent images of the right breast showed non-mass-like lesions. These findings suggested the presence of both benign and malignant tumors. Pathological findings from US-guided core-needle biopsy of the left mass were highly suspicious of a malignant tumor. Excisional biopsy of both breasts was performed. We could define the diagnosis of breast cancer by the second opinion on pathological diagnosis. The tumor cells showed histological characteristics of NE-DCIS. Bilateral breast lesions had histopathological similarities and were composed of predominantly solid growth of carcinoma cells, frequently with well-developed vascular structures, in mammary ducts and ductules. Carcinoma cells were polygonal or occasionally spindle shaped and had fine-granular, relatively eosinophilic cytoplasm. The nuclei of these cells showed round to ovoid in shape and fine-granular chromatin pattern. There was not any invasive component, as confirmed by careful histological examination. Thus, additional immunohistochemical stainings for NE markers (chromogranin A and synaptophysin) were performed. Staining statuses of these markers were positive in almost all tumor cells from both breasts. Both tumors were therefore diagnosed as NE-DCIS. To our knowledge, this case is the first report of NE-DCIS diagnosed synchronously in both breasts. PMID:21735237

Honami, Hisae; Sotome, Keiichi; Sakamoto, Goi; Iri, Hisami; Tanaka, Yoichi; Fukamachi, Shigeru; Morozumi, Kyoei

2014-07-01

336

In-situ bioassays using caged bivalves  

SciTech Connect

It is important to make the distinction between chemical measurements to assess bioaccumulation potential versus biological measurements to assess potential bioeffects because bioaccumulation is not a bioeffect. Caging provides a unique opportunity to make synoptic measurements of each and facilitates making these measurements over space and time. Measuring bioaccumulation in resident and transplanted bivalves has probably been the most frequently used form of an in-situ bioassay because bivalves concentrate chemicals in their tissues. They are also easy to collect, cage, and measure. The authors have refined bivalve bioassay methods by minimizing the size range of test animals, making repetitive measurements of the same individuals, and standardizing test protocols for a variety of applications. They are now attempting to standardize criteria for accepting and interpreting data in the same way that laboratory bioassays have been standardized. Growth measurements can serve two purposes in this assessment strategy: (1) An integrated biological response endpoint that is easily quantifiable and with significance to the population, and (2) A means of calibrating bioaccumulation by assessing the relative health and physiological state of tissues that have accumulated the chemicals. In general, the authors have found the highest bioconcentration factors associated with the highest growth rates, the highest concentrations ({micro}g/g) of chemicals in juvenile mussels, and the highest chemical content ({micro}g/animal) in adult mussels. Without accounting for possible dilution of chemical concentrations by tissue growth or magnification through degrowth, contaminant concentrations can be misleading. Examples are provided for the Sudbury River in Massachusetts (Elliptio complanata), San Diego Bay (Mytilus galloprovincialis), and the Harbor Island Superfund Site in Puget Sound (Mytilus trossulus).

Salazar, M.H.; Salazar, S.M.

1995-12-31

337

Mass spectrometry imaging for biomedical applications  

PubMed Central

The development of mass spectrometry imaging technologies is of significant current research interest. Mass spectrometry potentially is capable of providing highly specific information about the distribution of chemical compounds on tissues at highly sensitive levels. The required in-situ analysis for the tissue imaging forced MS analysis being performed off the traditional conditions optimized in pharmaceutical applications with intense sample preparation. This critical review seeks to present an overview of the current status of the MS imaging with different sampling ionization methods and to discuss the 3D imaging and quantitative imaging capabilities needed to be further developed, the importance of the multi-modal imaging, and a balance between the pursuit of the high imaging resolution and the practical application of MS imaging in biomedicine. PMID:23539099

Liu, Jiangjiang; Ouyang, Zheng

2013-01-01

338

Particle Analysis by Laser Mass Spectrometry  

NSDL National Science Digital Library

PALMS (Particle Analysis by Laser Mass Spectrometry), a laser ion mass spectrometer run by the National Oceanic and Atmospherics Association's (NOAA's) Meteorological Chemistry Group, makes in-situ measurements of the chemical composition of individual aerosol particles. PALMS has a lab version and a flight version, which is carried on the nose of an aircraft. The PALMS Website gives spectral data from the Spring 1998 flight mission and from 1993 measurements from Idaho Hill, Colorado, 1995 measurements from Cape Grim, Tasmania, and a link to a data page for the Atlanta, Georgia station. Throughout the site's data pages are links to other universities and other institutions using PALMS or involved in aerosol spectrometry research. A list of publications related to PALMS is also provided.

339

External gamma-ray dose rate and radon concentration in indoor environments covered with Brazilian granites.  

PubMed

Health hazard from natural radioactivity in Brazilian granites, covering the walls and floor in a typical dwelling room, was assessed by indirect methods to predict external gamma-ray dose rates and radon concentrations. The gamma-ray dose rate was estimated by a Monte Carlo simulation method and validated by in-situ measurements with a NaI spectrometer. Activity concentrations of (232)Th, (226)Ra, and (40)K in an extensive selection of Brazilian commercial granite samples measured by using gamma-ray spectrometry were found to be 4.5-450 Bq kg(-1), 4.9-160 Bq kg(-1) and 190-2029 Bq kg(-1), respectively. The maximum external gamma-ray dose rate from floor and walls covered with the Brazilian granites in the typical dwelling room (5.0 m × 4.0 m area, 2.8 m height) was found to be 120 nGy h(-1), which is comparable with the average worldwide exposure to external terrestrial radiation of 80 nGy h(-1) due to natural sources, proposed by United Nations Scientific Committee on the Effects of Atomic Radiation. Radon concentrations in the room were also estimated by a simple mass balance equation and exhalation rates calculated from the measured values of (226)Ra concentrations and the material properties. The results showed that the radon concentration in the room ventilated adequately (0.5 h(-1)) will be lower than 100 Bq m(-3), value recommended as a reference level by the World Health Organization. PMID:21729819

Anjos, R M; Juri Ayub, J; Cid, A S; Cardoso, R; Lacerda, T

2011-11-01

340

Microbeam titanium isotopic analysis by resonance ionization mass spectrometry  

SciTech Connect

The importance of isotopic anomalies in refractory inclusions in meteorites is well established. Measurements of the anomalies using conventional mass spectrometry are often rendered difficult, however, by isobarically interfering isotopes: for example, {sup 48}Ti and {sup 48}Ca. Resonance ionization mass spectrometry (RIMS) can substantially reduce isobaric interferences in a number of systems. We have employed RIMS for the in situ detection of Ti atoms sputtered from pure Ti metal and from several terrestrial oxides containing both Ti and Ca. Tunable lasers were employed to resonantly ionize neutral Ti atoms. We have chosen Ti specifically because of the importance of Ti isotopic anomalies in cosmochemistry.

Spiegel, D.R.; Davis, A.M.; Clayton, R.N. (Chicago Univ., IL (USA). Enrico Fermi Inst.); Pellin, M.J.; Calaway, W.F.; Burnett, J.W.; Coon, S.R.; Young, C.E.; Gruen, D.M. (Argonne National Lab., IL (USA))

1991-01-01

341

NOVEL IN-SITU METAL AND MINERAL EXTRACTION TECHNOLOGY  

SciTech Connect

This white paper summarizes the state of art of in-situ leaching of metals and minerals, and describes a new technology concept employing improved fragmentation of ores underground in order to prepare the ore for more efficient in-situ leaching, combined with technology to continuously improve solution flow patterns through the ore during the leaching process. The process parameters and economic benefits of combining the new concept with chemical and biological leaching are described. A summary is provided of the next steps required to demonstrate the technology with the goal of enabling more widespread use of in-situ leaching.

Glenn O'Gorman; Hans von Michaelis; Gregory J. Olson

2004-09-22

342

Cell Growth on In Situ Photo-Cross-Linked Electrospun Acrylated Cellulose Acetate Butyrate.  

PubMed

In this study, electrospinning was combined with UV curing technology for producing in situ photo cross-linked fibers from methacrylated cellulose acetate butyrate (CABIEM). ECV304 and 3T3 cells were seeded on electrospun fibrous scaffolds. Collagen modified CABIEM fibers were also prepared for improving cell adhesion and proliferation. Cross-linking and the morphology of the fibers were characterized by ATR-FT-IR spectrometry and environmental scanning electron microscopy (ESEM). The cytotoxicity of the fibers was examined using the MTT cytotoxicity assay. According to the results, electrospun fibrous scaffolds are non-toxic and cell viability depends on the amount of collagen. It was found that cell adhesion and cell growth were enhanced as the collagen percentage was increased. PMID:21457618

Cakmakç?, Emrah; Güngör, Atilla; Kayaman-Apohan, Nilhan; Kuruca, Serap Erdem; Cetin, Muzaffer Beyza; Dar, Kadriye Akgün

2011-03-31

343

Synthesis of Tailored Nanoparticles in Flames: Chemical Kinetics, In Situ Diagnostics, Numerical Simulation, and Process Development  

NASA Astrophysics Data System (ADS)

Flame synthesis of nanoparticles provides access to a wide variety of metal oxide nanoparticles. Detailed understanding of the underlying fundamental processes is a prerequisite for the synthesis of specific materials with well-defined properties. Multiple steps from gas-phase chemistry, inception of first particles and particle growth are thus investigated in detail to provide the information required for setting up chemistry and particle dynamics models that allow simulating particle synthesis apparatus. Experiments are carried out in shock wave and flow reactors with in situ optical diagnostics, such as absorption, laser-induced fluorescence, and laser-induced incandescence, with in-line sampling via mass spectrometry as well as with thermophoretic sampling for ex situ microscopic analysis and electronic characterization. Focus is on tuning particle size as well as crystallinity and stoichiometry, with a specific focus on sub-stoichiometric materials with tunable composition.

Wiggers, Hartmut; Fikri, Mustapha; Wlokas, Irenaeus; Roth, Paul; Schulz, Christof

344

In situ chemical probing of the electrode-electrolyte interface by ToF-SIMS.  

PubMed

A portable vacuum interface allowing direct probing of the electrode-electrolyte interface was developed. A classical electrochemical system consisting of a gold working electrode, platinum counter electrode, platinum reference electrode, and potassium iodide electrolyte was used to demonstrate real-time observation of the gold iodide adlayer on the electrode and chemical species as a result of redox reactions using cyclic voltammetry (CV) and time-of-flight secondary ion mass spectrometry (ToF-SIMS, a vacuum-based surface technique) simultaneously. This microfluidic electrochemical probe provides a new way to investigate the surface region with adsorbed molecules and the region of the diffused layer with chemical speciation in liquids in situ by surface sensitive techniques. PMID:24356670

Liu, Bingwen; Yu, Xiao-Ying; Zhu, Zihua; Hua, Xin; Yang, Li; Wang, Zhaoying

2014-03-01

345

Characterization of MYC-induced tumorigenesis by in situ lipid profiling.  

PubMed

We apply desorption electrospray ionization mass spectrometry imaging (DESI-MSI) to provide an in situ lipidomic profile of genetically modified tissues from a conditional transgenic mouse model of MYC-induced hepatocellular carcinoma (HCC). This unique, label-free approach of combining DESI-MSI with the ability to turn specific genes on and off has led to the discovery of highly specific lipid molecules associated with MYC-induced tumor onset. We are able to distinguish normal from MYC-induced malignant cells. Our approach provides a strategy to define a precise molecular picture at a resolution of about 200 ?m that may be useful in identifying lipid molecules that define how the MYC oncogene initiates and maintains tumorigenesis. PMID:23560736

Perry, Richard H; Bellovin, David I; Shroff, Emelyn H; Ismail, Ali I; Zabuawala, Tahera; Felsher, Dean W; Zare, Richard N

2013-05-01

346

In Situ Measurements of Meteoric Ions  

NASA Technical Reports Server (NTRS)

Extraterrestrial material is the source of metal ions in the Earth's atmosphere, Each year approx. 10(exp 8) kg of material is intercepted by the Earth. The origin of this material is predominantly solar orbiting interplanetary debris from comets or asteroids that crosses the Earth's orbit. It contains a very small amount of interstellar material. On occasion the Earth passes through enhanced amounts of debris associated with the orbit of a decaying comet. This leads to enhanced meteor shower displays for up to several days. The number flux of shower material is typically several times the average sporadic background influx of material. Meteoric material is some of the earliest material formed in the solar system. By studying the relative elemental abundances of atmospheric metal ions, information can be gained on the chemical composition of cometary debris and the chemical makeup of the early solar system. Using in situ sampling with rocket-borne ion mass spectrometers; there have been approximately 50 flights that made measurements of the metal ion abundances at attitudes between 80 and 130 km. It is this altitude range where incoming meteoric particles am ablated, the larger ones giving rise to visible meteor. displays. In several rocket measurements isotopic ratios of different atomic ion mass components and metal molecular ion concentrations have been determined and used to identify unambiguously the measured species and to investigate the processes controlling the metal ion distributions The composition of the Earth's ionosphere was first sampled by an ion mass spectrometer flown an a rocket in 1956. In 1958 a rocket-borne ion spectrometer identified, fbr the first time, a layer of metal ions near 95 km. These data were interpreted as evidence of an extraterrestrial rather than a terrestrial source. Istomin predicted: "It seems probable that with some improvement in the method that analysis of the ion composition in the E-region may be used for determining the chemical composition of those meteors which do not reach the ground. Particularly, we hope to get information about the composition difference between particles of different meteor showers and also sporadic and shower meteoroids". These visions categorized the aims of many subsequent rocket-borne ion mass spectrometer experiments in the lower ionosphere, Although the use such measurements to deduce the composition of different classes of meteoroids has not been successful, the past four decades of rocket observations have provided po%erful sets of data for advancing our understanding of meteor ablation, meteoric composition, metal neutral and ion chemistry as well as ionospheric dynamics.

Grebowsky, Joseph M.; Aiken, Arthur C.; Einaudi, Franco (Technical Monitor)

2001-01-01

347

In situ reaction on Cu(OH)2 nanoribbons for controlling growth of nanorods arrays of copper oxalate.  

PubMed

Cu(OH)2 nanoribbons template provides a simple way for producing arrays of copper oxalate nanorods and assemblies with controllable size and shape of the arrays of copper oxalate in situ reaction on Cu(OH)2 nanoribbons. The observations of scanning electron microscopy and characterization of X-ray powder diffraction and Fourier transmission infrared spectrometry show formation of the arrays of cubic column nanorods, nanotubes, and corn-like nanorods of CuC2O4 by controlling the concentration of oxalate solution and reaction time. We believe this approach can also be applied for synthesis of inorganic and inorganic/organic material architectures. PMID:17450866

Cui, Shuang; Liu, Huibiao; Jiang, Li; Zhong, Zhifeng; Feng, Xiaoping; Zhu, Yulan; Li, Yuliang

2007-03-01

348

Development of a solenoid pumped in situ zinc analyzer for environmental monitoring  

USGS Publications Warehouse

A battery powered submersible chemical analyzer, the Zn-DigiScan (Zn Digital Submersible Chemical Analyzer), has been developed for near real-time, in situ monitoring of zinc in aquatic systems. Microprocessor controlled solenoid pumps propel sample and carrier through an anion exchange column to separate zinc from interferences, add colorimetric reagents, and propel the reaction complex through a simple photometric detector. The Zn-DigiScan is capable of self-calibration with periodic injections of standards and blanks. The detection limit with this approach was 30 ??g L-1. Precision was 5-10% relative standard deviation (R.S.D.) below 100 ??g L-1, improving to 1% R.S.D. at 1000 ??g L-1. The linear range extended from 30 to 3000 ??g L-1. In situ field results were in agreement with samples analyzed by inductively coupled plasma mass spectrometry (ICPMS). This pump technology is quite versatile and colorimetric methods with complex online manipulations such as column reduction, preconcentration, and dilution can be performed with the DigiScan. However, long-term field deployments in shallow high altitude streams were hampered by air bubble formation in the photometric detector. ?? 2005 Elsevier B.V. All rights reserved.

Chapin, T.P.; Wanty, R.B.

2005-01-01

349

Design and characterization of nanoknife with buffering beam for in situ single-cell cutting  

NASA Astrophysics Data System (ADS)

A novel nanoknife with a buffering beam is proposed for single-cell cutting. The nanoknife was fabricated from a commercial atomic force microscopy (AFM) cantilever by focused-ion-beam (FIB) etching technique. The material identification of the nanoknife was determined using the energy dispersion spectrometry (EDS) method. It demonstrated that the gallium ion pollution of the nanoknife can be ignored during the etching processes. The buffering beam was used to measure the cutting force based on its deformation. The spring constant of the beam was calibrated based on a referenced cantilever by using a nanomanipulation approach. The tip of the nanoknife was designed with a small edge angle 5° to reduce the compression to the cell during the cutting procedure. For comparison, two other nanoknives with different edge angles, i.e. 25° and 45°, were also prepared. An in situ single-cell cutting experiment was performed using these three nanoknives inside an environmental scanning electron microscope (ESEM). The cutting force and the sample slice angle for each nanoknife were evaluated. It showed the compression to the cell can be reduced when using the nanoknife with a small edge angle 5°. Consequently, the nanoknife was capable for in situ single-cell cutting tasks.

Shen, Yajing; Nakajima, Masahiro; Yang, Zhan; Kojima, Seiji; Homma, Michio; Fukuda, Toshio

2011-07-01

350

Developing in-situ ellipsometry for tokamak discharges in KSTAR  

NASA Astrophysics Data System (ADS)

An in-situ ellipsometer based on four-detector polarimeter(FDP) is under development at KSTAR. In-situ ellipsometer for tokamak discharges will measure the characteristics of thin films deposited onto a quartz window near the edge region in real time. These characteristics contain local deposition/erosion rates as well as hydrogen to carbon ratio, which have to be measured in-situ, for more clear insight view of plasma-wall interaction in tokamak edge plasmas. This paper reports the status of in-situ ellipsometer development for tokamak discharges at KSTAR, to study plasma-wall interaction and fuel retention. Basic concept, design and construction of the ellipsometer are described.

Hong, Suk-Ho; Kim, Woong-Chae

2010-05-01

351

GEOSAFE CORPORATION IN SITU VITRIFICATION: INNOVATIVE TECHNOLOGY EVALUATION REPORT  

EPA Science Inventory

This report summarizes the findings associated with a Demonstration of the Geosafe Corporation (Geosafe) In Situ Vitrification (ISV) Process. he Geosafe ISV Technology was evaluated under the EPA Superfund Innovative Technology Evaluation (SITE) Program in conjuction with remedia...

352

SITE TECHNOLOGY CAPSULE: GEOSAFE CORPORATION IN SITU VITRIFICATION TECHNOLOGY  

EPA Science Inventory

The Geosafe In Situ Vitrification (ISV) Technology is designed to treat soils, sludges, sediments, and mine tallings contaminated with organic, inorganic, and radioactive compounds. The organic compounds are pyrolyzed and reduced to simple gases which are collected under a treatm...

353

GEOSAFE CORPORATION IN SITU VITRIFICATION: INNOVATIVE TECHNOLOGY EVALUATION REPORT  

EPA Science Inventory

This report summarizes the findings associated with a Demonstration of the Geosafe Corporation (Geosafe) In Situ Vitrification (ISV) Process. The Geosafe ISV Technology was evaluated under the EPA Superfund Innovative Technology Evaluation (SITE) Program in conjuction with remedi...

354

Epoxy nanodielectrics fabricated with in situ and ex situ techniques  

SciTech Connect

In this study, we report fabrication and characterisation of a nanocomposite system composed of a commercial resin and extremely small (several nanometres in diameter) titanium dioxide particles. Nanoparticles were synthesised in situ with particle nucleation occurring inside the resin matrix. In this nanodielectric fabrication method, the nanoparticle precursor was mixed to the resin solution, and the nanoparticles were in situ precipitated. Note that no high shear mixing equipment was needed to improve particle dispersion - nanoparticles were distributed in the polymer matrix uniformly since particle nucleation occurs uniformly throughout the matrix. The properties of in situ nanodielectrics are compared to the unfilled resin and an ex situ nanocomposite. We anticipate that the presented in situ nanocomposite would be employed in high-temperature superconductivity applications. In additions, the improvement shown in the dielectric breakdown indicates that conventional high-voltage components and systems can be reduced in size with novel nanodielectrics.

Tuncer, Enis [ORNL; Polyzos, Georgios [ORNL; Sauers, Isidor [ORNL; James, David Randy [ORNL; Ellis, Alvin R [ORNL; More, Karren Leslie [ORNL

2012-01-01

355

78 FR 47427 - AUC, LLC Reno Creek, In Situ  

Federal Register 2010, 2011, 2012, 2013

...and Operate the Reno Creek ISR Project AGENCY...operate its proposed Reno Creek, In Situ Leach Uranium...Basin near Wright, Wyoming. DATES: Requests for...facility at AUC's Reno Creek site near Wright, Wyoming. Requirements for...

2013-08-05

356

In situ sampling cart development engineering task plan  

SciTech Connect

This Engineering Task Plan (ETP) supports the development for facility use of the next generation in situ sampling system for characterization of tank vapors. In situ sampling refers to placing sample collection devices (primarily sorbent tubes) directly into the tank headspace, then drawing tank gases through the collection devices to obtain samples. The current in situ sampling system is functional but was not designed to provide the accurate flow measurement required by today`s data quality objectives (DQOs) for vapor characterization. The new system will incorporate modern instrumentation to achieve much tighter control. The next generation system will be referred to in this ETP as the New In Situ System (NISS) or New System. The report describes the current sampling system and the modifications that are required for more accuracy.

DeFord, D.K.

1995-02-06

357

Regulation of Glycolysis in Mouse Brain in Situ During Convulsions.  

National Technical Information Service (NTIS)

The concentrations of metabolites, including glucose, glycogen, glycolytic intermediates, adenine nucleotides, phosphates, amino acids, and citrate, in mouse brain in situ were measured from 15 to 180 sec after exposure of mice to the convulsant, 'Indoklo...

B. Sacktor, J. E. Wilson, C. G. Tiekert

1966-01-01

358

Advanced hydraulic fracturing methods to create in situ reactive barriers  

SciTech Connect

This article describes the use of hydraulic fracturing to increase permeability in geologic formations where in-situ remedial action of contaminant plumes will be performed. Several in-situ treatment strategies are discussed including the use of hydraulic fracturing to create in situ redox zones for treatment of organics and inorganics. Hydraulic fracturing methods offer a mechanism for the in-situ treatment of gently dipping layers of reactive compounds. Specialized methods using real-time monitoring and a high-energy jet during fracturing allow the form of the fracture to be influenced, such as creation of assymmetric fractures beneath potential sources (i.e. tanks, pits, buildings) that should not be penetrated by boring. Some examples of field applications of this technique such as creating fractures filled with zero-valent iron to reductively dechlorinate halogenated hydrocarbons, and the use of granular activated carbon to adsorb compounds are discussed.

Murdoch, L. [FRX Inc., Cincinnati, OH (United States)]|[Clemson Univ., SC (United States). Dept. of Geological Sciences; Siegrist, B.; Meiggs, T. [Oak Ridge National Lab., TN (United States)] [and others

1997-12-31

359

Treatment Options for Lobular Carcinoma In Situ (LCIS)  

MedlinePLUS

... Childhood (for information about childhood breast cancer) Health history can affect the risk of developing breast cancer. ... birth or never having given birth. A personal history of invasive breast cancer , ductal carcinoma in situ ( ...

360

SITE TECHNOLOGY CAPSULE; IN SITU ELECTROKINETIC EXTRACTION SYSTEM  

EPA Science Inventory

As a part of the Superfund Innovative Technology Evaluation (SITE) Program, the U.S. Environmental Protection Agency evaluated the In-Situ Electrokinetic Extraction (ISEE) system at Sandia National Laboratories, Albuquerque, New Mexico. The SITE demonstration results show ...

361

In Situ Instrument to Detect Prebiotic Compounds in Planetary Ices  

NASA Technical Reports Server (NTRS)

The development of an in situ LC-MS instrument for future planetary science missions to icy surfaces that are of high astrobiology and astrochemistry potential will advance our understanding of organics in the solar system.

Getty, Stephanie A.; Dworkin, Jason; Glavin, Daniel P.; Southard, Adrian; Balvin, Manuel; Kotecki, Carl; Ferrance, Jerome

2013-01-01

362

Hyperopic laser in situ keratomileusis to treat overcorrected myopic LASIK  

Microsoft Academic Search

PurposeTo evaluate the safety and efficacy of hyperopic laser in situ keratomileusis (LASIK) in treating hyperopia caused by overcorrected myopic LASIK and to evaluate a new technique to place the hyperopic treatment after lifting the initial myopic flap.

Jason M Jacobs; Matthew C Sanderson; Lawrence D Spivack; John R Wright; Alfred D Roberts; Michael J Taravella

2001-01-01

363

In-situ derivatisation of degradation products of chemical warfare agents in water by solid-phase microextraction and gas chromatographic–mass spectrometric analysis  

Microsoft Academic Search

A new analytical procedure was developed for the extraction of degradation products of chemical warfare agents from water and for in-situ derivatisation prior to analysis by gas chromatography–mass spectrometry (GC–MS). With this new procedure, degradation products of the chemical warfare agents can be analysed and identified without going through laborious sample preparation. Parameters such as fiber selection, pH, salt content,

Mui Tiang Sng; Wei Fang Ng

1999-01-01

364

Laser wavelength selection for Raman spectroscopy of microbial pigments in situ in Antarctic desert ecosystem analogues of former habitats on Mars  

Microsoft Academic Search

The vital ultraviolet- (UV-) protective and photosynthetic pigments of cyanobacteria and lichens (microbial symbioses) that dominate primary production in Antarctic desert ecosystems auto-fluoresce at short wavelengths. We therefore use a long-wavelength (1064 nm) infrared laser for non-intrusive in situ Raman spectrometry of their ecologically significant compounds (especially pigments). To confirm that the power loss at this longer wavelength is justified

Howell G. M. Edwards; Emma M. Newton; David D. Wynn-Williams; David Dickensheets; Chris Schoen; Chelle Crowder

2002-01-01

365

In-Situ Production Cost Model for Uranium  

Microsoft Academic Search

In a recently completed research project for the U.S. Bureau of Mines -Twin Cities Research Center, a computerized costing procedure for uranium in-situ leach mining was developed by the NUS Corporation. This costing procedure, termed a cost model, employs a process engineering approach for estimating total project costs as well as equipment and manpower requirements for uranium in-situ leaching operations

G. W. Toth; W. C. Larson

1983-01-01

366

BAW and SAW sensors for in-situ analysis  

NASA Technical Reports Server (NTRS)

In-situ analysis is a major goal in current and future NASA exploration missions. In general in-situ analysis experiments are designed to investigate chmical, biological or geological markers or properties to determine the complex history of the body being studied. In order to expand the number of applicable sensor schemes an investigation into piezoelectric bulk acoustic wave (BAW) and surface acoustic wave (SAW) resonators has been initiated.

Bar-Cohen, Y.; Bao, X. Q.; Chang, Z.; Sherrit, S.

2003-01-01

367

In Situ Resource Utilization (ISRU II) Technical Interchange Meeting  

NASA Technical Reports Server (NTRS)

This volume contains extended abstracts that have been accepted for presentation at the In Situ Resource Utilization (ISRU II) Technical Interchange Meeting, November 18-19, 1997, at the Lunar and Planetary Institute, Houston, Texas. Included are topics which include: Extraterrestrial resources, in situ propellant production, sampling of planetary surfaces, oxygen production, water vapor extraction from the Martian atmosphere, gas generation, cryogenic refrigeration, and propellant transport and storage.

Kaplan, David (Compiler); Saunders, Stephen R. (Compiler)

1997-01-01

368

Volumetric In Situ Electrical Heating: An Unexploited Electrotechnology  

E-print Network

with other enhanced oil recovery systems to reduce air pollution and to provide a market for excess electrical power generation capacity. other applications of the EEOR technology include the in situ decontamination of hazardous waste spills...-oil reservoirs and into a more environmentally benign method for decontaminating, in situ, warehouse-size blocks of earth near the surface. Further, we extended the technology to treat volumes of material such as hospital wastes and radioactive materials...

Bridges, J. E.

369

In situ diffusion experiment in granite: phase I.  

PubMed

A program of in situ experiments, supported by laboratory studies, was initiated to study diffusion in sparsely fractured rock (SFR), with a goal of developing an understanding of diffusion processes within intact crystalline rock. Phase I of the in situ diffusion experiment was started in 1996, with the purpose of developing a methodology for estimating diffusion parameter values. Four in situ diffusion experiments, using a conservative iodide tracer, were performed in highly stressed SFR at a depth of 450 m in the Underground Research Laboratory (URL). The experiments, performed over a 2 year period, yielded rock permeability estimates of 2 x 10(-21) m(2) and effective diffusion coefficients varying from 2.1 x 10(-14) to 1.9 x 10(-13) m(2)/s, which were estimated using the MOTIF code. The in situ diffusion profiles reveal a characteristic "dog leg" pattern, with iodide concentrations decreasing rapidly within a centimeter of the open borehole wall. It is hypothesized that this is an artifact of local stress redistribution and creation of a zone of increased constrictivity close to the borehole wall. A comparison of estimated in situ and laboratory diffusivities and permeabilities provides evidence that the physical properties of rock samples removed from high-stress regimes change. As a result of the lessons learnt during Phase I, a Phase II in situ program has been initiated to improve our general understanding of diffusion in SFR. PMID:12598104

Vilks, P; Cramer, J J; Jensen, M; Miller, N H; Miller, H G; Stanchell, F W

2003-03-01

370

21 CFR 866.4700 - Automated fluorescence in situ hybridization (FISH) enumeration systems.  

Code of Federal Regulations, 2011 CFR

...Automated fluorescence in situ hybridization (FISH) enumeration systems. 866.4700 ...fluorescence in situ hybridization (FISH) enumeration systems. (a) Identification . An automated FISH enumeration system is a device...

2011-04-01

371

21 CFR 866.4700 - Automated fluorescence in situ hybridization (FISH) enumeration systems.  

...Automated fluorescence in situ hybridization (FISH) enumeration systems. 866.4700 ...fluorescence in situ hybridization (FISH) enumeration systems. (a) Identification. An automated FISH enumeration system is a device...

2014-04-01

372

21 CFR 866.4700 - Automated fluorescence in situ hybridization (FISH) enumeration systems.  

Code of Federal Regulations, 2013 CFR

...Automated fluorescence in situ hybridization (FISH) enumeration systems. 866.4700 ...fluorescence in situ hybridization (FISH) enumeration systems. (a) Identification . An automated FISH enumeration system is a device...

2013-04-01

373

21 CFR 866.4700 - Automated fluorescence in situ hybridization (FISH) enumeration systems.  

Code of Federal Regulations, 2012 CFR

...Automated fluorescence in situ hybridization (FISH) enumeration systems. 866.4700 ...fluorescence in situ hybridization (FISH) enumeration systems. (a) Identification . An automated FISH enumeration system is a device...

2012-04-01

374

21 CFR 866.4700 - Automated fluorescence in situ hybridization (FISH) enumeration systems.  

Code of Federal Regulations, 2010 CFR

...Automated fluorescence in situ hybridization (FISH) enumeration systems. 866.4700 ...fluorescence in situ hybridization (FISH) enumeration systems. (a) Identification . An automated FISH enumeration system is a device...

2010-04-01

375

IN SITU FIELD TESTING OF PROCESSES  

SciTech Connect

The purpose of this scientific analysis report is to update and document the data and subsequent analyses from ambient field-testing activities performed in underground drifts and surface-based boreholes through unsaturated zone (UZ) tuff rock units. In situ testing, monitoring, and associated laboratory studies are conducted to directly assess and evaluate the waste emplacement environment and the natural barriers to radionuclide transport at Yucca Mountain. This scientific analysis report supports and provides data to UZ flow and transport model reports, which in turn contribute to the Total System Performance Assessment (TSPA) of Yucca Mountain, an important document for the license application (LA). The objectives of ambient field-testing activities are described in Section 1.1. This report is the third revision (REV 03), which supercedes REV 02. The scientific analysis of data for inputs to model calibration and validation as documented in REV 02 were developed in accordance with the Technical Work Plan (TWP) ''Technical Work Plan for: Performance Assessment Unsaturated Zone'' (BSC 2004 [DIRS 167969]). This revision was developed in accordance with the ''Technical Work Plan for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654], Section 1.2.4) for better integrated, consistent, transparent, traceable, and more complete documentation in this scientific analysis report and associated UZ flow and transport model reports. No additional testing or analyses were performed as part of this revision. The list of relevant acceptance criteria is provided by ''Technical Work Plan for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654]), Table 3-1. Additional deviations from the TWP regarding the features, events, and processes (FEPs) list are discussed in Section 1.3. Documentation in this report includes descriptions of how, and under what conditions, the tests were conducted. The descriptions and analyses provide data useful for refining and confirming the understanding of flow, drift seepage, and transport processes in the UZ. The UZ testing activities included measurement of permeability distribution, quantification of the seepage of water into the drifts, evaluation of fracture-matrix interaction, study of flow along faults, testing of flow and transport between drifts, characterization of hydrologic heterogeneity along drifts, estimation of drying effects on the rock surrounding the drifts due to ventilation, monitoring of moisture conditions in open and sealed drifts, and determination of the degree of minimum construction water migration below drift. These field tests were conducted in two underground drifts at Yucca Mountain, the Exploratory Studies Facility (ESF) drift, and the cross-drift for Enhanced Characterization of the Repository Block (ECRB), as described in Section 1.2. Samples collected in boreholes and underground drifts have been used for additional hydrochemical and isotopic analyses for additional understanding of the UZ setting. The UZ transport tests conducted at the nearby Busted Butte site (see Figure 1-4) are also described in this scientific analysis report.

J.S.Y. YANG

2004-11-08

376

SENSITIVITY STUDIES FOR AN IN-SITU PARTIAL DEFECT DETECTOR (PDET) IN SPENT FUEL USING MONTE CARLO TECHNIQUES  

SciTech Connect

This study presents results from Monte Carlo radiation transport calculations aimed at characterizing a novel methodology being developed to detect partial defects in Pressurized Water Reactor (PWR) spent fuel assemblies (SFAs). The methodology uses a combination of measured neutron and gamma fields inside a spent fuel assembly in an in-situ condition where no movement of the fuel assembly is required. Previous studies performed on single isolated assemblies resulted in a unique base signature that would change when some of the fuel in the assembly is replaced with dummy fuel. These studies indicate that this signature is still valid in the in-situ condition enhancing the prospect of building a practical tool, Partial Defect Detector (PDET), which can be used in the field for partial defect detection.

Sitaraman, S; Ham, Y S

2008-04-28

377

In-Situ Phase Mapping and Direct Observations of Phase Transformations During Arc Welding of 1045 Steel  

SciTech Connect

In-situ Spatially Resolved X-Ray Diffraction (SRXRD) experiments were performed during gas tungsten arc (GTA) welding of AISI 1045 C-Mn steel. Ferrite ({alpha}) and austenite ({gamma}) phases were identified and quantified in the weld heat-affected zone (HAZ) from the real time x-ray diffraction data. The results were compiled along with weld temperatures calculated using a coupled thermal fluids weld model to create a phase map of the HAZ. This map shows the {alpha} {yields} {gamma} transformation taking place during weld heating and the reverse {gamma} {yields} {alpha} transformation taking place during weld cooling. Superheating is required to complete the {alpha} {yields} {gamma} phase transformation, and the amount of superheat above the A3 temperature was shown to vary with distance from the centerline of the weld. Superheat values as high as 250 C above the A3 temperature were observed at heating rates of 80 C/s. The SRXRD experiments also revealed details about the {gamma} phase not observable by conventional techniques, showing that {gamma} is present with two distinct lattice parameters as a result of inhomogeneous distribution of carbon and manganese in the starting pearlitic/ferritic microstructure. During cooling, the reverse {gamma} {yields} {alpha} phase transformation was shown to depend on the HAZ location. In the fine grained region of the HAZ, at distances greater than 2 mm from the fusion line, the {gamma} {yields} {alpha} transformation begins near the A3 temperature and ends near the A1 temperature. In this region of the HAZ where the cooling rates are below 40 C/s, the transformation occurs by nucleation and growth of pearlite. For HAZ locations closer to the fusion line, undercoolings of 200 C or more below the A1 temperature are required to complete the {gamma} {yields} {alpha} transformation. In this region of the HAZ, grain growth coupled with cooling rates in excess of 50 C/s causes the transformation to occur by a bainitic mechanism.

Elmer, J; Palmer, T

2005-09-13

378

In situ Management and Domestication of Plants in Mesoamerica  

PubMed Central

Background and Aims Ethnobotanical studies in Mexico have documented that Mesoamerican peoples practise systems of in situ management of wild and weedy vegetation directed to control availability of useful plants. In situ management includes let standing, encouraging growing and protection of individual plants of useful species during clearance of vegetation, which in some cases may involve artificial selection. The aim of this study was to review, complement and re-analyse information from three case studies which examined patterns of morphological, physiological and genetic effects of artificial selection in plant populations under in situ management in the region. Methods Information on wild and in situ managed populations of the herbaceous weedy plants Anoda cristata and Crotalaria pumila, the tree Leucaena esculenta subsp. esculenta and the columnar cacti Escontria chiotilla, Polaskia chichipe and Stenocereus stellatus from Central Mexico was re-analysed. Analyses compared morphology and frequency of morphological variants, germination patterns, and population genetics parameters between wild and managed in situ populations of the species studied. Species of columnar cacti are under different management intensities and their populations, including cultivated stands of P. chichipe and S. stellatus, were also compared between species. Key Results Significant differences in morphology, germination patterns and genetic variation documented between wild, in situ managed and cultivated populations of the species studied are associated with higher frequencies of phenotypes favoured by humans in managed populations. Genetic diversity in managed populations of E. chiotilla and P. chichipe is slightly lower than in wild populations but in managed populations of S. stellatus variation was higher than in the wild. However, genetic distance between populations was generally small and influenced more by geographic distance than by management. Conclusions Artificial selection operating on in situ managed populations of the species analysed is causing incipient domestication. This process could be acting on any of the 600–700 plant species documented to be under in situ management in Mesoamerica. In situ domestication of plants could be relevant to understand early processes of domestication and current conditions of in situ conservation of plant genetic resources. PMID:17652338

Casas, Alejandro; Otero-Arnaiz, Adriana; Perez-Negron, Edgar; Valiente-Banuet, Alfonso

2007-01-01

379

Mass spectrometry of atmospheric aerosols--recent developments and applications. Part II: On-line mass spectrometry techniques.  

PubMed

Many of the significant advances in our understanding of atmospheric particles can be attributed to the application of mass spectrometry. Mass spectrometry provides high sensitivity with fast response time to probe chemically complex particles. This review focuses on recent developments and applications in the field of mass spectrometry of atmospheric aerosols. In Part II of this two-part review, we concentrate on real-time mass spectrometry techniques, which provide high time resolution for insight into brief events and diurnal changes while eliminating the potential artifacts acquired during long-term filter sampling. In particular, real-time mass spectrometry has been shown recently to provide the ability to probe the chemical composition of ambient individual particles <30 nm in diameter to further our understanding of how particles are formed through nucleation in the atmosphere. Further, transportable real-time mass spectrometry techniques are now used frequently on ground-, ship-, and aircraft-based studies around the globe to further our understanding of the spatial distribution of atmospheric aerosols. In addition, coupling aerosol mass spectrometry techniques with other measurements in series has allowed the in situ determination of chemically resolved particle effective density, refractive index, volatility, and cloud activation properties. PMID:21449003

Pratt, Kerri A; Prather, Kimberly A

2012-01-01

380

Method for rapid localization of seafloor petroleum contamination using concurrent mass spectrometry and acoustic positioning  

Microsoft Academic Search

Locating areas of seafloor contamination caused by heavy oil spills is challenging, in large part because of observational limitations in aquatic subsurface environments. Accepted methods for surveying and locating sunken oil are generally slow, labor intensive and spatially imprecise. This paper describes a method to locate seafloor contamination caused by heavy oil fractions using in situ mass spectrometry and concurrent

R. Camilli; B. Bingham; C. M. Reddy; R. K. Nelson; A. N. Duryea

2009-01-01

381

Gamma scanning the primary circuit of the Peach Bottom HTGR  

Microsoft Academic Search

The plateout distribution of gamma-emitting nuclides in the primary circuit of the Peach Bottom HTGR at end-of-life has been determined by in situ gamma scanning. The specific activity was mapped by scanning the accessible ducting at 12 locations with a Ge(Li) detector and by axially traversing 79 steam generator tubes with travelling CdTe detectors from the water side. Following destructive

D. L. Hanson; N. L. Baldwin; W. E. Selph

1976-01-01

382

In-Situ TEM Study of Interface Sliding and Migration in an Ultrafine Lamellar Structure  

SciTech Connect

The instability of interfaces in an ultrafine TiAl-({gamma})/Ti{sub 3}Al-({alpha}{sub 2}) lamellar structure by straining at room temperature has been investigated using in-situ straining techniques performed in a transmission electron microscope. The purpose of this study is to obtain experimental evidence to support the creep mechanisms based upon the interface sliding in association with a cooperative movement of interfacial dislocations previously proposed to interpret the nearly linear creep behavior observed from ultrafine lamellar TiAl alloys. The results have revealed that both the sliding and migration of lamellar interfaces can take place simultaneously as a result of the cooperative movement of interfacial dislocations.

Hsiung, L M

2005-12-06

383

In situ visualization of newly synthesized proteins in environmental microbes using amino acid tagging and click chemistry.  

PubMed

Here we describe the application of a new click chemistry method for fluorescent tracking of protein synthesis in individual microorganisms within environmental samples. This technique, termed bioorthogonal non-canonical amino acid tagging (BONCAT), is based on the in vivo incorporation of the non-canonical amino acid L-azidohomoalanine (AHA), a surrogate for l-methionine, followed by fluorescent labelling of AHA-containing cellular proteins by azide-alkyne click chemistry. BONCAT was evaluated with a range of phylogenetically and physiologically diverse archaeal and bacterial pure cultures and enrichments, and used to visualize translationally active cells within complex environmental samples including an oral biofilm, freshwater and anoxic sediment. We also developed combined assays that couple BONCAT with ribosomal RNA (rRNA)-targeted fluorescence in situ hybridization (FISH), enabling a direct link between taxonomic identity and translational activity. Using a methanotrophic enrichment culture incubated under different conditions, we demonstrate the potential of BONCAT-FISH to study microbial physiology in situ. A direct comparison of anabolic activity using BONCAT and stable isotope labelling by nano-scale secondary ion mass spectrometry ((15)NH(3) assimilation) for individual cells within a sediment-sourced enrichment culture showed concordance between AHA-positive cells and (15)N enrichment. BONCAT-FISH offers a fast, inexpensive and straightforward fluorescence microscopy method for studying the in situ activity of environmental microbes on a single-cell level. PMID:24571640

Hatzenpichler, Roland; Scheller, Silvan; Tavormina, Patricia L; Babin, Brett M; Tirrell, David A; Orphan, Victoria J

2014-08-01

384

In Situ Monitoring of Hafnium Oxide Atomic Layer Deposition  

NASA Astrophysics Data System (ADS)

Atomic layer deposition (ALD) is increasingly being utilized as a method of depositing the thin (nanometer-scale), conformal layers required for microelectronics applications such as high ? gate dielectric layers and diffusion barriers. However, significant process development issues remain for implementation of this technology in many applications. One potential solution to some process development issues is in situ monitoring. In situ monitoring of atomic layer deposition processes has the potential to yield insights that will enable efficiencies in film growth, in the development of deposition recipes, and in the design and qualification of reactors. However, demonstrations of in situ monitoring of actual atomic layer deposition processes are limited. In this work, the species present in the gas phase during atomic layer deposition of hafnium oxide were investigated in an attempt to gain insight into the chemistry of this system and evaluate potential in situ gas phase optical monitors. Hafnium oxide was deposited on a silicon substrate using tetrakis(ethylmethylamino) hafnium (TEMAH) and water as the hafnium and oxygen sources, respectively. In situ infrared absorption spectroscopic measurements were performed near the growth surface in a research-grade, horizontal-flow reactor under a range of deposition conditions. Density functional theory quantum calculations of vibrational frequencies of expected species were used to facilitate identification of observed spectral features.

Maslar, J. E.; Hurst, W. S.; Burgess, D. R.; Kimes, W. A.; Nguyen, N. V.; Moore, E. F.

2007-09-01

385

In situ Measurements of Phytoplankton Fluorescence Using Low Cost Electronics  

PubMed Central

Chlorophyll a fluorometry has long been used as a method to study phytoplankton in the ocean. In situ fluorometry is used frequently in oceanography to provide depth-resolved estimates of phytoplankton biomass. However, the high price of commercially manufactured in situ fluorometers has made them unavailable to some individuals and institutions. Presented here is an investigation into building an in situ fluorometer using low cost electronics. The goal was to construct an easily reproducible in situ fluorometer from simple and widely available electronic components. The simplicity and modest cost of the sensor makes it valuable to students and professionals alike. Open source sharing of architecture and software will allow students to reconstruct and customize the sensor on a small budget. Research applications that require numerous in situ fluorometers or expendable fluorometers can also benefit from this study. The sensor costs US$150.00 and can be constructed with little to no previous experience. The sensor uses a blue LED to excite chlorophyll a and measures fluorescence using a silicon photodiode. The sensor is controlled by an Arduino microcontroller that also serves as a data logger. PMID:23783738

Leeuw, Thomas; Boss, Emmanuel S.; Wright, Dana L.

2013-01-01

386

In situ measurements of phytoplankton fluorescence using low cost electronics.  

PubMed

Chlorophyll a fluorometry has long been used as a method to study phytoplankton in the ocean. In situ fluorometry is used frequently in oceanography to provide depth-resolved estimates of phytoplankton biomass. However, the high price of commercially manufactured in situ fluorometers has made them unavailable to some individuals and institutions. Presented here is an investigation into building an in situ fluorometer using low cost electronics. The goal was to construct an easily reproducible in situ fluorometer from simple and widely available electronic components. The simplicity and modest cost of the sensor makes it valuable to students and professionals alike. Open source sharing of architecture and software will allow students to reconstruct and customize the sensor on a small budget. Research applications that require numerous in situ fluorometers or expendable fluorometers can also benefit from this study. The sensor costs US$150.00 and can be constructed with little to no previous experience. The sensor uses a blue LED to excite chlorophyll a and measures fluorescence using a silicon photodiode. The sensor is controlled by an Arduino microcontroller that also serves as a data logger. PMID:23783738

Leeuw, Thomas; Boss, Emmanuel S; Wright, Dana L

2013-01-01

387

Rapid in situ detection of alkaloids in plant tissue under ambient conditions using desorption electrospray ionization.  

PubMed

Desorption electrospray ionization (DESI) mass spectrometry is applied to the in situ detection of alkaloids in the tissue of poison hemlock (Conium maculatum), jimsonweed (Datura stramonium) and deadly nightshade (Atropa belladonna). The experiment is carried out by electrospraying micro-droplets of solvent onto native or freshly-cut plant tissue surfaces. No sample preparation is required and the mass spectra are recorded under ambient conditions, in times of a few seconds. The impact of the sprayed droplets on the surface produces gaseous ions from organic compounds originally present in the plant tissue. The effects of operating parameters, including the electrospray high voltage, heated capillary temperature, the solvent infusion rate and the carrier gas pressure on analytical performance are evaluated and optimized. Different types of plant material are analyzed including seeds, stems, leaves, roots and flowers. All the previously reported alkaloids have been detected in C. maculatum, while fifteen out of nineteen known alkaloids for D. stramonium and the principal alkaloids of A. belladonna were also identified. All identifications were confirmed by tandem mass spectrometry. Results obtained show similar mass spectra, number of alkaloids, and signal intensities to those obtained when extraction and separation processes are performed prior to mass spectrometric analysis. Evidence is provided that DESI ionization occurs by both a gas-phase ionization process and by a droplet pick-up mechanism. Quantitative precision of DESI is compared with conventional electrospray ionization mass spectrometry (after sample workup) and the RSD values for the same set of 25 dicotyledonous C. maculatum seeds (one half of each seed analyzed by ESI and the other by DESI) are 9.8% and 5.2%, respectively. PMID:16284661

Talaty, Nari; Takáts, Zoltán; Cooks, R Graham

2005-12-01

388

Analysis of excursions at selected in situ uranium mines in Wyoming and Texas. [Case studies  

Microsoft Academic Search

Intensive research and development of in situ uranium mining took place in the United States during the 1970s. By the end of the decade, nearly 10% of all uranium production came from in situ mines. Recent poor market conditions, however, forced the closure of all domestic in situ uranium mines. When market conditions improve, domestic in situ mining is expected

W. P. Staub; R. E. Williams; F. Anastasi; N. E. Hinkle; J. Osiensky; D. Rogness

1986-01-01

389

In situ observation of deformation-induced interface migration in a fully-lamellar TiAl alloy  

SciTech Connect

It has been reported previously that the mobility of interfacial dislocations plays a dominant role in the creep deformation behavior of a fully-lamellar (FL) TiAl alloy fabricated by powder metallurgy (P/M). Since the motion of lattice dislocations within the {gamma} lamellae is largely restricted by a refined lamellar spacing within the P/M alloy, the deformation strain is mainly accommodated by the motion of the interfacial dislocations. The creep resistance of the P/M alloy significantly increases when the motion of interfacial dislocations in the twin ({gamma}/{gamma}{sub T}) or interphase ({gamma}/{alpha}{sub 2}) interface is effectively hindered by a well developed deformation substructure such as mechanical (deformation) twins. In parallel to this study, other investigation reported in the literature have also suggested that the lamellar interfaces of TiAl are glissile. It is possible that the lamellar interfaces in TiAl, under certain circumstances, could migrate (advance) directly through the cooperative motion of interfacial dislocations. That is, the {gamma}/{gamma}{sub T} or {gamma}/{alpha}{sub 2} interface can migrate through the cooperative motion of interfacial dislocations and lead to the growth or shrinkage of the {gamma} or {alpha}{sub 2} lamellae. Therefore, a deformation-induced interfacial instability in fully-lamellar TiAl alloys could result in a weakening effect when the alloys are employed for engineering applications. Although it is anticipated that the interface migration is prevalent at elevated temperatures, the present study, in fact, addresses the influence of deformation on the stability of lamellar interfaces at room temperature. An in situ straining experiment in a transmission electron microscope was incorporated for the investigation.

Hsiung, L.M.; Schwartz, A.J.; Nieh, T.G. [Lawrence Livermore National Lab., CA (United States)] [Lawrence Livermore National Lab., CA (United States)

1997-05-01

390

In situ, spatially resolved biosignature detection at the microbial scale  

NASA Astrophysics Data System (ADS)

Whether life has ever existed beyond Earth is one of the great human questions. The Science Definition Team (SDT) for the proposed NASA Mars 2020 rover mission recently announced a suggested approach for NASA to 'demonstrate significant technical progress towards the future return of scientifically selected, well-documented samples to Earth' in part 'to investigate whether Mars was ever inhabited by microbial life.' The SDT further recommended a per-sample volume of 8 cm3 [1] (e.g., a core with a diameter of 1 cm and length of 10 cm). Such samples would be the first available for scientific inquiry with the potential to definitively answer the fundamental question of astrobiology, and their small volume would necessitate analysis with non- or minimally destructive techniques. Potential biosignatures include 'chemical, isotopic, mineralogical, and morphological features that can be created by life and also appear to be inconsistent with nonbiological processes'[1]. Guidelines for biosignature detection in extraterrestrial samples derive in part from the search for evidence of life in the most ancient sedimentary rocks on Earth, wherein the most compelling case for biogenicity is made when these 'chemical, isotopic, mineralogical, and morphological features' occur in association. Sedimentary rocks deposited on Earth prior to ~3.5 billion years ago (i.e., when persistent surface water [e.g., 2] likely supported habitable environments on Mars) have only very rarely escaped severe alteration by metamorphism and metasomatism. Understanding how these processes have operated on Earth through strategic interrogation of biosignature alteration records in (meta)sedimentary rocks is thus a critical task in the search for extraterrestrial life. Here we present techniques for and results of in situ, spatially resolved, non- or minimally destructive detection of morphological, elemental, molecular, and light stable isotopic biosignatures, as well as records of alteration, in Precambrian sedimentary rocks from Earth in the context of the eventual analysis of samples returned from Mars. Sample acquisition and preparation, morphological analysis by conventional light, confocal laser, and electron microscopy, elemental analysis by energy and wavelength dispersive spectroscopy, molecular analysis by laser Raman microscopy, carbon isotope analysis of organic matter and carbonate minerals, and multiple sulfur isotope analysis of pyrite with secondary ion mass spectrometry will be discussed. New and recently published [3-5] results from the application of these methods towards detection of the signatures of life, environment, and alteration history in rocks containing putative and bona fide microfossils ranging in age from 0.6 to 3.5 billion years, and in rocks of similar age lacking morphological biosignatures, as well as our current understanding of key challenges and opportunities for future research will be reviewed. [1] Mustard, J.F. et al. 2013. Report of the Mars 2020 Science Definition Team, 154 pp., posted by MEPAG at http://mepag.jpl.nasa.gov/reports/MEP/Mars_2020_SDT_Report_Final.pdf. [2] Williams, R.M.E. et al. 2013. Science 340: 1068-1072. [3] Williford, K.H. et al. 2011. GCA 75: 5686-5705. [4] Williford, K.H. et al. 2013. GCA 104: 165-182. [5] Lepot, K. et al. 2013. GCA 112: 66-86.

Williford, K. H.; Eigenbrode, J. L.; Hallmann, C.; Kitajima, K.; Kozdon, R.; Summons, R. E.; Kudryavstev, A.; Lepot, K.; Schopf, J.; Spicuzza, M.; Sugitani, K.; Ushikubo, T.; van Kranendonk, M.; Valley, J. W.

2013-12-01

391

In-Situ Resource Utilization (ISRU) Development Program  

NASA Technical Reports Server (NTRS)

The question "Why In-Situ Resource Utilization (ISRU)?" is addressed in this presentation. The reasons given concentrate on Cost reduction, Mass reduction, Risk reduction, the expansion of human exploration and presence and the enabling of industrial exploitation. A review of the Martian and Lunar resources available for ISRU is presented. Other ISRU concepts (i.e., In-Situ Consumable production (ISCP) and In-Situ Propellant Production (ISPP)) are introduced and further explained. The objectives of a Mars ISRU System Technology (MIST) include (1) the characterization of technology and subsystem performance for mission modeling and technology funding planning, (2) reduce risk and concerns arising from sample return and human missions utilizing ISRU, and (3) demonstrate the environmental suitability of ISRU components/processes and systems. A proof of concept demonstration schedule and a facility overview for MIST is presented.

Sanders, Jerry

1998-01-01

392

NMR methods for in-situ biofilm metabolism studies  

SciTech Connect

Novel procedures and instrumentation are described for nuclear magnetic resonance (NMR) spectroscopy and imaging studies of live, in situ microbial films. A perfused NMR/optical microscope sample chamber containing a planar biofilm support was integrated into a recirculation/dilution flow loop growth reactor system and used to grow in situ Shewanella oneidensis strain MR-1 biofilms. Localized NMR techniques were developed and used to non-invasively monitor time-resolved metabolite concentrations and to image the biomass volume and distribution. As a first illustration of the feasibility of the methodology an initial 13C-labeled lactate metabolic pathway study was performed, yielding results consistent with existing genomic data for MR-1. These results represent progress toward our ultimate goal of correlating time- and depth-resolved metabolism and mass transport with gene expression in live in situ biofilms using combined NMR/optical microscopy techniques.

Majors, Paul D.; Mclean, Jeffrey S.; Pinchuk, Gregory E.; Fredrickson, Jim K.; Gorby, Yuri A.; Minard, Kevin R.; Wind, Robert A.

2005-09-01

393

Robot-Assisted Antegrade In-Situ Fenestrated Stent Grafting  

SciTech Connect

To determine the technical feasibility of a novel approach of in-situ fenestration of aortic stent grafts by using a remotely controlled robotic steerable catheter system in the porcine model. A 65-kg pig underwent robot-assisted bilateral antegrade in-situ renal fenestration of an abdominal aortic stent graft with subsequent successful deployment of a bare metal stent into the right renal artery. A 16-mm iliac extension covered stent served as the porcine aortic endograft. Under fluoroscopic guidance, the graft was punctured with a 20-G customized diathermy needle that was introduced and kept in place by the robotic arm. The needle was exchanged for a 4 x 20 mm cutting balloon before successful deployment of the renal stent. Robot-assisted antegrade in-situ fenestration is technically feasible in a large mammalian model. The robotic system enables precise manipulation, stable positioning, and minimum instrumentation of the aorta and its branches while minimizing radiation exposure.

Riga, Celia V., E-mail: c.riga@imperial.ac.uk; Bicknell, Colin D. [Imperial College Healthcare, St Mary's Hospital, Regional Vascular Unit (United Kingdom); Wallace, Daniel [Hansen Medical (United States); Hamady, Mohamad; Cheshire, Nicholas [Imperial College Healthcare, St Mary's Hospital, Regional Vascular Unit (United Kingdom)

2009-05-15

394

In situ x-ray absorption fuel cell  

NASA Astrophysics Data System (ADS)

An in situ x-ray absorption spectroscopy cell was designed to study the structural and electronic properties of high performance polymer electrolyte fuel cell electrocatalysts. The cell was operated as a standard fuel cell and x-ray absorption data were collected simultaneously as the fuel cell operating conditions were varied. The cell was used to examine platinum-ruthenium alloy electrocatalysts incorporated in the anode of a fuel cell membrane and electrode assembly. In situ Pt LIII and Ru K edge x-ray absorption near-edge structure (XANES) data were collected at five selected current densities of the operating fuel cell. The XANES data show that under normal fuel cell operating conditions, the metallic nature of the Pt-Ru catalyst is retained. The cell design enabled an in situ fuel cell study at a synchrotron source in which no additional electrolytes were required.

Viswanathan, Rameshkrishnan; Liu, Renxuan; Smotkin, Eugene S.

2002-05-01

395

In-situ growth monitoring of molecular beam epitaxy processes  

NASA Astrophysics Data System (ADS)

The strong collaboration between Arizona State University and General Electric Corp. has resulted in a comprehensive program to develop intelligent, in-situ sensors for monitoring and control of semiconductor thin film growth by Molecular Beam Epitaxy (MBE). An intimate collaboration with a commercial MBE manufacturer (DCA Instruments) has resulted in a new ultra-stable substrate manipulator which is compatible with in-situ optical measurements. Another long time collaboration with an ellipsometer manufacturer (Woollam Co.) has generated a new prototype high speed in-situ spectroscopic ellipsometer. Both the manipulator and the ellipsometer have become commercial products. Adaptation of spectroscopic ellipsometry to real time MBE growth monitoring and development of advanced computer algorithms have enabled the tracking of epitaxial layer thickness, temperature and alloy composition. Temperature dependent (from room temperature to 650 deg C) optical constants of GaAs have been measured and verified. Work is continuing on obtaining optical constants for AlGaAs compound semiconductors.

Maracas, George N.; Sohie, Guy R.

1993-09-01

396

In-situ Rock Spalling Strength near Excavation Boundaries  

NASA Astrophysics Data System (ADS)

It is widely accepted that the in-situ strength of massive rocks is approximately 0.4 ± 0.1 UCS, where UCS is the uniaxial compressive strength obtained from unconfined tests using diamond drilling core samples with a diameter around 50 mm. In addition, it has been suggested that the in-situ rock spalling strength, i.e., the strength of the wall of an excavation when spalling initiates, can be set to the crack initiation stress determined from laboratory tests or field microseismic monitoring. These findings were supported by back-analysis of case histories where failure had been carefully documented, using either Kirsch's solution (with approximated circular tunnel geometry and hence ? max = 3? 1 -? 3) or simplified numerical stress modeling (with a smooth tunnel wall boundary) to approximate the maximum tangential stress ? max at the excavation boundary. The ratio of ? max /UCS is related to the observed depth of failure and failure initiation occurs when ? max is roughly equal to 0.4 ± 0.1 UCS. In this article, it is suggested that these approaches ignore one of the most important factors, the irregularity of the excavation boundary, when interpreting the in-situ rock strength. It is demonstrated that the "actual" in-situ spalling strength of massive rocks is not equal to 0.4 ± 0.1 UCS, but can be as high as 0.8 ± 0.05 UCS when surface irregularities are considered. It is demonstrated using the Mine-by tunnel notch breakout example that when the realistic "as-built" excavation boundary condition is honored, the "actual" in-situ rock strength, given by 0.8 UCS, can be applied to simulate progressive brittle rock failure process satisfactorily. The interpreted, reduced in-situ rock strength of 0.4 ± 0.1 UCS without considering geometry irregularity is therefore only an "apparent" rock strength.

Cai, M.; Kaiser, P. K.

2014-03-01

397

In-situ bioremediation drilling and characterization work plan  

SciTech Connect

This work plan describes the design and construction of proposed wells and outlines the characterization activities to be performed in support of the In Situ Bioremediation Task for FY 1994. The purpose of the well-design is to facilitate implementation and monitoring of in situ biodegradation of CCl{sub 4} in ground water. However, the wells will also be used to characterize the geology, hydrology, microbiology, and contaminant distribution, which will all feed into the design of the technology. Implementation and design of this remediation demonstration technology will be described separately in an integrated test plan.

Koegler, K.J.

1994-04-26

398

Bioremediation of solvent hydrocarbons: Laboratory and in situ field studies  

SciTech Connect

A multidisciplinary international site assessment and remediation project has been undertaken for an operating paint manufacturing site in Germany, with specialist input from collaborating research centers and remediation consultants from both Australia and Germany. After a detailed chemical and hydrogeological investigation revealed areas of contamination with aromatic and aliphatic solvent hydrocarbons, soil and groundwater samples were collected for detailed microcosm-based studies to demonstrate the potential for biodegradation of the contaminants of concern. In situ biodegradation rates in the unsaturated zone were established by a field test program involving air injection testing, tracer testing and in situ respiration studies. 2 refs., 4 tabs.

Peck, P.C.; Rhodes, S.H. [Minenco Pty. Ltd. Bioremediation Services, North Sydney (Australia); Anderson, B.N. [RMIT Univ., Melbourne, Victoria (Australia); Henkler, R.D. [Safety, Health and Environment, Berkshire (United Kingdom)

1996-12-31

399

A simplified In Situ cosmogenic 14C extraction system  

USGS Publications Warehouse

We describe the design, construction, and testing of a new, simplified in situ radiocarbon extraction system at the University of Arizona. Blank levels for the new system are low ((234 ?? 11) ?? 103 atoms (1 ??; n = 7)) and stable. The precision of a given measurement depends on the concentration of 14C, but is typically <5% for concentrations of 100 ?? 103 atoms g-1 or more. The new system is relatively small and easy to construct, costs significantly less than the original in situ 14C extraction system at Arizona, and lends itself to future automation. ?? 2010 by the Arizona Board of Regents on behalf of the University of Arizona.

Pigati, J.S.; Lifton, N.A.; Timothy, Jull A.J.; Quade, J.

2010-01-01

400

In situ bioremediation strategies for organic wood preservatives  

SciTech Connect

Laboratory biotreatability studies evaluated the use of bioventing and biosparging plus groundwater circulation (UVB technology) for their potential ability to treat soil and groundwater containing creosote and pentachlorophenol. Soils from two former wood-treatment facilities were used in these studies. These studies provided useful, site-specific data demonstrating enhanced biodegradation of all monitored organic constituents. The results suggest that the introduction and delivery of co-reagents (i.e., oxygen and nitrogen) essential to in situ biodegradation of organic wood preservatives represents an important component of effective in situ bioremediation. Full-scale implementation strategies are being considered based on the findings of these studies.

Mueller, J.G. [SBP Technologies Inc., Gulf Breeze, FL (United States); Tischuk, M.D.; Brourman, M.D. [Beazer East, Pittsburgh, PA (United States); Steeg, G.E. Van De [Kerr McGee Corp., Oklahoma City, OK (United States)

1995-12-31

401

Engineered approaches for in situ bioremediation of chlorinated solvent contamination  

SciTech Connect

Throughout the world there are sites contaminated with chlorinated compounds such as perchloroethylene, trichloroethylene, tetrachloromethene, carbon tetrachloride, pentachlorophenol, chlorinated benzenes, and various pesticide/herbicide compounds. Not only do these compounds carry health risks, but they also are challenging and often expensive to treat in the field. However, progress is being made, and this volume brings together the most up-to-date laboratory findings and the latest full-scale results from bioremediation efforts at actual field sites. Engineering approaches discussed include biobarriers, cometabolism, bioaugmentation, in situ oxidation, Genton's Reagent, in situ bioremediation, and more.

Alleman, B.C.; Leeson, A.

1999-01-01

402

Engineered approaches for in situ bioremediation of chlorinated solvent contamination  

SciTech Connect

Throughout the world there are sites contaminated with chlorinated compounds such as perchloroethylene, trichloroethylene, tetrachloromethene, carbon tetrachloride, pentachlorophenol, chlorinated benzenes, and various pesticide/herbicide compounds. Not only do these compounds carry health risks, but they also are challenging and often expensive to treat in the field. However, progress is being made, and this volume brings together the most up-to-date laboratory findings and the latest full-scale results from bioremediation efforts at actual field sites. Engineering approaches discussed include biobarriers, cometabolism, bioaugmentation, in situ oxidation, Genton`s Reagent, in situ bioremediation, and more.

Alleman, B.C.; Leeson, A.

1999-11-01

403

Engineered approaches for in situ bioremediation of chlorinated solvent contamination  

SciTech Connect

Throughout the world there are sites contaminated with chlorinated compounds such as perchloroethylene, trichloroethylene, tetrachloromethene, carbon tetrachloride, pentachlorophenol, chlorinated benzenes, and various pesticide/herbicide compounds. Not only do these compounds carry health risks, but they also are challenging and often expensive to treat in the field. However, progress is being made, and this volume brings together the most up-to-date laboratory findings and the latest full-scale results from bioremediation efforts at actual field sites. Engineering approaches discussed include biobarriers, cometabolism, bioaugmentation, in situ oxidation, Fenton`s Reagent, in situ bioremediation, and more.

Alleman, B.C.; Leeson, A. [eds.

1999-10-01

404

In situ radiometric mapping as a proxy of sediment contamination: assessment of the underlying geochemical and -physical principles.  

PubMed

Correlations between sediment contaminants like heavy metals or organic micro-compounds and natural or anthropogenic radionuclides ((40)K, (238)U, (232)Th, (137)Cs) facilitates in situ mapping of the contaminated sediment using gamma-ray detectors. These maps can be made quickly and economically using surveys with towed underwater gamma-ray detectors and based on the fundamental correlation of contaminants with radioactivity. This paper aims at an assessment of the geochemical and -physical principles underlying these correlations. This assessment uses multivariate analysis of a data base containing information on radionuclides and contaminants for a large number of sediment samples used to derive radionuclide-contaminant correlations in radiometric mapping projects in freshwater bodies of the Netherlands. More specifically, the aims of this study are to test if these correlations are valid for the entire Dutch freshwater environment and to investigate the validity of the thesis that these correlations are mainly due to the presence of clay. PMID:17258466

van der Graaf, E R; Koomans, R L; Limburg, J; de Vries, K

2007-05-01

405

Diagnosis of In Situ Metabolic State and Rates of Microbial Metabolism During In Situ Uranium Bioremediation with Molecular Techniques  

SciTech Connect

The goal of these projects was to develop molecule tools to tract the metabolic activity and physiological status of microorganisms during in situ uranium bioremediation. Such information is important in able to design improved bioremediation strategies. As summarized below, the research was highly successful with new strategies developed for estimating in situ rates of metabolism and diagnosing the physiological status of the predominant subsurface microorganisms. This is a first not only for groundwater bioremediation studies, but also for subsurface microbiology in general. The tools and approaches developed in these studies should be applicable to the study of microbial communities in a diversity of soils and sediments.

Lovley, Derek R

2012-11-28

406

In-Situ TEM Observations of Strain-Induced Interface Instability in TiAl/Ti3Al Laminate Composite  

SciTech Connect

The stability of interfaces in lamellar TiAl (or TiAl/Ti{sub 3}Al laminate composite) by straining at ambient temperatures has been investigated using in-situ staining techniques performed in a transmission electron microscope in order to obtain direct evidence to support the previously proposed creep mechanisms in refined lamellar TiAl based upon the interface sliding in association with the cooperative motion of interfacial dislocations. It has been reported previously that the mobility of interfacial dislocations can play a crucial role in the creep deformation behavior of refined lamellar TiAl [1,2]. Since the operation of lattice dislocations within refined {alpha}{sub 2} and {gamma} lamellae is largely restricted, the motion of interfacial dislocations becomes the major strain carrier for plasticity. Results of ex-situ TEM investigation have revealed the occurrence of interface sliding in low-stress (LS) creep regime and deformation twinning in high-stress (HS) creep regime. These results have led us to propose that interface sliding associated with a viscous glide of pre-existing interfacial dislocations is the predominant creep mechanism in LS regime and interface-activated deformation twinning in {gamma} lamellae is the predominant creep mechanism in HS regime. Stress concentration resulted from the pileup of interfacial dislocations is suggested to be the cause for the interface-activated deformation twinning. Accordingly, the creep resistance of refined lamellar TiAl is considered to depend greatly on the cooperative motion of interfacial dislocations, which in turn may solely be controlled and hindered by the interfacial segregation of solute atoms (such as W) or interfacial precipitation. Furthermore, through the in-situ TEM investigation, we also found that the lamellar interfaces could migrate directly through the cooperative motion of interfacial dislocations. That is, the {gamma}/{gamma}and {gamma}/{alpha}{sub 2} interfaces can migrate through interface sliding and lead to the coalescence or shrinkage of constituent lamellae (i.e. microstructural instability), which results in a weakening effect when refined lamellar TiAl is employed for engineering applications. Although it is anticipated that interface sliding and migration are prevalent at elevated temperatures, the present in-situ straining study reveals the instability of lamellar interfaces at ambient temperatures.

Hsiung, L L

2003-04-08

407

In-Situ Exploration of Venus: Major Science Objectives, Investigations, and Mission Platform Options  

NASA Astrophysics Data System (ADS)

In-situ missions to Venus have been recommended by both the 2011 and 2003 Decadal Studies of the NRC and have been proposed numerous times to NASA's Discovery and New Frontiers programs as well as to ESA's Cosmic Vision program. Such missions would revolutionize our understanding of Venus, as they address key questions of Venus's origin, evolution, and current state via high precision measurements of (1) noble gases and their isotopes, and (2) reactive trace gases and aerosol associated with Venus's active photo- and thermo-chemistry and sulfur cycle, including components potentially responsible for the poorly-understood uv-absorbing haze layer. Fundamental questions, as promoted in recent VEXAG documents, include: (1) Did Venus, Mars, and Earth have a common origin? (2) What roles did comets from the outer Solar System play in delivering volatiles to Venus? (3) Did Venus once have and lose a global ocean? (4) How much has Venus outgassed, and what is the current rate of outgassing, particularly of sulfur, the major driver of Venus clouds? and (5) Through the deposition of energy within them, what role do these clouds play in (a) driving the cloud-level thermal structure and (b) generating and maintaining the super-rotating zonal windfield that covers the globe? Fundamental answers could be uniquely provided through in-situ sampling via mass spectrometry of the noble gases and their isotopes - in particular of the 8 stable Xe isotopes, the bulk abundances of Kr, and the 3 isotopes of Ne. Measurements of the relative abundances of the light isotopes of N, O, H, S and O, by, for example, tunable laser spectrometry, would provide additional insights into Venus's origin, surface outgassing and planetary escape. Such measurements could be performed by probes, landers, or balloons. On descent through the uv-absorbing layer and the surrounding H2SO4 cloud, each of these platforms could explore both the absorber and sulfur-cycle-associated reactive species and aerosols, thus addressing VEXAG desires for enhanced understanding of Venus' chemical cycles, aerosol properties, and radiative transfer. On descent to the surface, probes and landers can provide vertical profiles of temperatures and species abundances, as well as provide near-surface measurements of sulfur isotopes and trace sulfuric gases indicative of outgassing. Additional major in-situ goals dealing with Venus's global circulation and local dynamics can be addressed by a balloon platform floating within the convective middle cloud near ~55-km altitude. Drifting over a wide range of latitudes and all times-of-day and longitudes, such a floating platform could accurately measure (1) motions in all three dimensions - zonal, meridional, and vertical, including motions associated with convection and gravity waves, (2) simultaneous measurements of cloud particle size, their parent molecules, the local temperature, and vertical velocity, to study cloud formation/dissipation processes, and (3) the power and frequency of local lightning. Altogether, such in-situ measurements would potentially revolutionize our understanding of (1) Venus's circulation, including the role of waves and solar cloud heating in powering the planet's poorly-understood super-rotation, (2) Venus's sulfur cycle, key to Venus's current climate, and (3) how Earth's neighbor formed and evolved over the aeons.

Baines, K. H.; Limaye, S. S.; Hall, J. L.; Atreya, S. K.; Bullock, M. A.; Crisp, D.; Grinspoon, D. H.; Mahaffy, P. R.; Russell, C. T.; Webster, C. R.; Zahnle, K. J.

2013-12-01

408

Product evaluation of in situ vitrification engineering, Test 4  

SciTech Connect

This report is one of several that evaluates the In Situ Vitrification (ISV) Engineering-Scale Test 4 (ES-4). This document describes the chemical and physical composition, microstructure, and leaching characteristics of ES-4 product samples; these data provide insight into the expected performance of a vitrified product in an ISV buried waste application similar to that studied in ES-4.

Loehr, C.A.; Weidner, J.R.; Bates, S.O.

1991-09-01

409

IN SITU FIELD PORTABLE FINE PARTICLE MEASURING DEVICE  

EPA Science Inventory

The report describes the design, development, and testing of an in situ fine particle measuring device--the Fine Particle Stack Spectrometer System (FPSSS). It is a laser-fed optical system with detection by near-forward light scattering. Sample volume is established by a high-re...

410

Nylon 6\\/Graphite Fiber Composites by in Situ Polymerization  

Microsoft Academic Search

The in situ polymerization of caprolactam to Nylon 6 was investigated as a method for making graphite fiber composites. It was necessary to find a co-catalyst (using sodium caprolactam as catalyst) which could be mixed at about 100°C and where the final mixture had a long enough pot life to allow for mixing and application to the fibers. The temperature

Morton H. Litt; Allan W. Brinkmann

1973-01-01

411

PEMERIKSAAN ABERASI KROMOSOM STABIL DENGAN TEHNIK FLUORESENCE IN SITU HYBRIDIZATION  

Microsoft Academic Search

MEASUREMENT OF STABLE CHROMOSOME ABERRATIONS BY FLUORESENCE IN SITU HYBRIDIZATION TECHNIQUE. Measurement of translocation as stable chromosome aberrations becomes a very important tool to detect cytogenetic damages in lymphocytes due to radiation exposure in prediction and assessment of immediate and late radiation effects. Translocation is also considered as optimum cytogeneric parameter for long-term retrospective biodosimetry. The aim of this study

Zubaidah Alatas; Pusat Teknologi

412

Fluorescence In Situ Hybridization in Studying the Human Genome  

Microsoft Academic Search

Physical chromosome mapping by fluorescence in situ hybridization (FISH) is among the major lines of research on the human genome (as well as genomes of numerous other organisms). To localize particular genes or anonymous DNA sequences on individual chromosomes or chromosome regions, FISH was developed in the late 1980s and early 1990s, when the International Human Genome Project and the

A. V. Zelenin

2004-01-01

413

An Improved In Situ and Satellite SST Analysis for Climate  

Microsoft Academic Search

A weekly 18 spatial resolution optimum interpolation (OI) sea surface temperature (SST) analysis has been produced at the National Oceanic and Atmospheric Administration (NOAA) using both in situ and satellite data from November 1981 to the present. The weekly product has been available since 1993 and is widely used for weather and climate monitoring and forecasting. Errors in the satellite

Richard W. Reynolds; Nick A. Rayner; Thomas M. Smith; Diane C. Stokes; Wanqiu Wang

2002-01-01

414

IN-SITU FENTON OXIDATION: A CRITICAL ANALYSIS  

EPA Science Inventory

In-situ Fenton oxidation (ISFO) is a rapidly emerging technology which involves the injection of hydrogen peroxide (H2O2) and other chemical reagents into the subsurface for the purpose of oxidizing and transforming contaminants. ISFO is being applied at an increasing number of ...

415

TECHNOLOGIES FOR IN-SITU TREATMENT OF HAZARDOUS WASTES  

EPA Science Inventory

The paper will give a general overview/problem definition and state-of-the-art of the natural processes of biodegradation and chemical transformations. The importance and problems of delivery and recovery systems will be emphasized. In-situ