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Sample records for in-situ gas analysis

  1. Versatile in situ gas analysis apparatus for nanomaterials reactors.

    PubMed

    Meysami, Seyyed Shayan; Snoek, Lavina C; Grobert, Nicole

    2014-09-01

    We report a newly developed technique for the in situ real-time gas analysis of reactors commonly used for the production of nanomaterials, by showing case-study results obtained using a dedicated apparatus for measuring the gas composition in reactors operating at high temperature (<1000 °C). The in situ gas-cooled sampling probe mapped the chemistry inside the high-temperature reactor, while suppressing the thermal decomposition of the analytes. It thus allows a more accurate study of the mechanism of progressive thermocatalytic cracking of precursors compared to previously reported conventional residual gas analyses of the reactor exhaust gas and hence paves the way for the controlled production of novel nanomaterials with tailored properties. Our studies demonstrate that the composition of the precursors dynamically changes as they travel inside of the reactor, causing a nonuniform growth of nanomaterials. Moreover, mapping of the nanomaterials reactor using quantitative gas analysis revealed the actual contribution of thermocatalytic cracking and a quantification of individual precursor fragments. This information is particularly important for quality control of the produced nanomaterials and for the recycling of exhaust residues, ultimately leading toward a more cost-effective continuous production of nanomaterials in large quantities. Our case study of multiwall carbon nanotube synthesis was conducted using the probe in conjunction with chemical vapor deposition (CVD) techniques. Given the similarities of this particular CVD setup to other CVD reactors and high-temperature setups generally used for nanomaterials synthesis, the concept and methodology of in situ gas analysis presented here does also apply to other systems, making it a versatile and widely applicable method across a wide range of materials/manufacturing methods, catalysis, as well as reactor design and engineering.

  2. Versatile in situ gas analysis apparatus for nanomaterials reactors.

    PubMed

    Meysami, Seyyed Shayan; Snoek, Lavina C; Grobert, Nicole

    2014-09-01

    We report a newly developed technique for the in situ real-time gas analysis of reactors commonly used for the production of nanomaterials, by showing case-study results obtained using a dedicated apparatus for measuring the gas composition in reactors operating at high temperature (<1000 °C). The in situ gas-cooled sampling probe mapped the chemistry inside the high-temperature reactor, while suppressing the thermal decomposition of the analytes. It thus allows a more accurate study of the mechanism of progressive thermocatalytic cracking of precursors compared to previously reported conventional residual gas analyses of the reactor exhaust gas and hence paves the way for the controlled production of novel nanomaterials with tailored properties. Our studies demonstrate that the composition of the precursors dynamically changes as they travel inside of the reactor, causing a nonuniform growth of nanomaterials. Moreover, mapping of the nanomaterials reactor using quantitative gas analysis revealed the actual contribution of thermocatalytic cracking and a quantification of individual precursor fragments. This information is particularly important for quality control of the produced nanomaterials and for the recycling of exhaust residues, ultimately leading toward a more cost-effective continuous production of nanomaterials in large quantities. Our case study of multiwall carbon nanotube synthesis was conducted using the probe in conjunction with chemical vapor deposition (CVD) techniques. Given the similarities of this particular CVD setup to other CVD reactors and high-temperature setups generally used for nanomaterials synthesis, the concept and methodology of in situ gas analysis presented here does also apply to other systems, making it a versatile and widely applicable method across a wide range of materials/manufacturing methods, catalysis, as well as reactor design and engineering. PMID:25090251

  3. Methodology for in situ gas sampling, transport and laboratory analysis of gases from stranded cetaceans

    NASA Astrophysics Data System (ADS)

    de Quirós, Yara Bernaldo; González-Díaz, Óscar; Saavedra, Pedro; Arbelo, Manuel; Sierra, Eva; Sacchini, Simona; Jepson, Paul D.; Mazzariol, Sandro; di Guardo, Giovanni; Fernández, Antonio

    2011-12-01

    Gas-bubble lesions were described in cetaceans stranded in spatio-temporal concordance with naval exercises using high-powered sonars. A behaviourally induced decompression sickness-like disease was proposed as a plausible causal mechanism, although these findings remain scientifically controversial. Investigations into the constituents of the gas bubbles in suspected gas embolism cases are highly desirable. We have found that vacuum tubes, insulin syringes and an aspirometer are reliable tools for in situ gas sampling, storage and transportation without appreciable loss of gas and without compromising the accuracy of the analysis. Gas analysis is conducted by gas chromatography in the laboratory. This methodology was successfully applied to a mass stranding of sperm whales, to a beaked whale stranded in spatial and temporal association with military exercises and to a cetacean chronic gas embolism case. Results from the freshest animals confirmed that bubbles were relatively free of gases associated with putrefaction and consisted predominantly of nitrogen.

  4. Methodology for in situ gas sampling, transport and laboratory analysis of gases from stranded cetaceans

    PubMed Central

    de Quirós, Yara Bernaldo; González-Díaz, Óscar; Saavedra, Pedro; Arbelo, Manuel; Sierra, Eva; Sacchini, Simona; Jepson, Paul D.; Mazzariol, Sandro; Di Guardo, Giovanni; Fernández, Antonio

    2011-01-01

    Gas-bubble lesions were described in cetaceans stranded in spatio-temporal concordance with naval exercises using high-powered sonars. A behaviourally induced decompression sickness-like disease was proposed as a plausible causal mechanism, although these findings remain scientifically controversial. Investigations into the constituents of the gas bubbles in suspected gas embolism cases are highly desirable. We have found that vacuum tubes, insulin syringes and an aspirometer are reliable tools for in situ gas sampling, storage and transportation without appreciable loss of gas and without compromising the accuracy of the analysis. Gas analysis is conducted by gas chromatography in the laboratory. This methodology was successfully applied to a mass stranding of sperm whales, to a beaked whale stranded in spatial and temporal association with military exercises and to a cetacean chronic gas embolism case. Results from the freshest animals confirmed that bubbles were relatively free of gases associated with putrefaction and consisted predominantly of nitrogen. PMID:22355708

  5. In situ gas analysis for high pressure applications using property measurements

    NASA Astrophysics Data System (ADS)

    Moeller, J.; Span, R.; Fieback, T.

    2013-10-01

    As the production, distribution, and storage of renewable energy based fuels usually are performed under high pressures and as there is a lack of in situ high pressure gas analysis instruments on the market, the aim of this work was to develop a method for in situ high pressure gas analysis of biogas and hydrogen containing gas mixtures. The analysis is based on in situ measurements of optical, thermo physical, and electromagnetic properties in gas mixtures with newly developed high pressure sensors. This article depicts the calculation of compositions from the measured properties, which is carried out iteratively by using highly accurate equations of state for gas mixtures. The validation of the method consisted of the generation and measurement of several mixtures, of which three are presented herein: a first mixture of 64.9 mol. % methane, 17.1 mol. % carbon dioxide, 9 mol. % helium, and 9 mol. % ethane at 323 K and 423 K in a pressure range from 2.5 MPa to 17 MPa; a second mixture of 93.0 mol. % methane, 4.0 mol. % propane, 2.0 mol. % carbon dioxide, and 1.0 mol. % nitrogen at 303 K, 313 K, and 323 K in a pressure range from 1.2 MPa to 3 MPa; and a third mixture of 64.9 mol. % methane, 30.1 mol. % carbon dioxide, and 5.0 mol. % nitrogen at 303 K, 313 K, and 323 K in a pressure range from 2.5 MPa to 4 MPa. The analysis of the tested gas mixtures showed that with measured density, velocity of sound, and relative permittivity the composition can be determined with deviations below 1.9 mol. %, in most cases even below 1 mol. %. Comparing the calculated compositions with the generated gas mixture, the deviations were in the range of the combined uncertainty of measurement and property models.

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

    NASA Astrophysics Data System (ADS)

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

    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

  7. Modeling and Analysis of the Reverse Water Gas Shift Process for In-Situ Propellant Production

    NASA Technical Reports Server (NTRS)

    Whitlow, Jonathan E.

    2000-01-01

    This report focuses on the development of mathematical models and simulation tools developed for the Reverse Water Gas Shift (RWGS) process. This process is a candidate technology for oxygen production on Mars under the In-Situ Propellant Production (ISPP) project. An analysis of the RWGS process was performed using a material balance for the system. The material balance is very complex due to the downstream separations and subsequent recycle inherent with the process. A numerical simulation was developed for the RWGS process to provide a tool for analysis and optimization of experimental hardware, which will be constructed later this year at Kennedy Space Center (KSC). Attempts to solve the material balance for the system, which can be defined by 27 nonlinear equations, initially failed. A convergence scheme was developed which led to successful solution of the material balance, however the simplified equations used for the gas separation membrane were found insufficient. Additional more rigorous models were successfully developed and solved for the membrane separation. Sample results from these models are included in this report, with recommendations for experimental work needed for model validation.

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

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

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

  9. Search for organics in extraterrestrial environments by in situ gas chromatography analysis

    NASA Astrophysics Data System (ADS)

    Rodier, C.; Sternberg, R.; Szopa, C.; Buch, A.; Cabane, M.; Raulin, F.

    Many organic molecules are present in interstellar clouds and might be carried to the early Earth by comets and meteorites during the heavy bombardment period 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. This assumption is significantly supported by the study of the Murchison meteorite that revealed more than 500 organic compounds, including several nucleic acid bases and 80 amino acids, 8 of them being proteinaceous. Investigation of extraterrestrial environments therefore appears of primary interest to determine the nature of the organic molecules (either endogenous or exogenous) which could be present on Earth when prebiotic chemistry occurred and life emerged. Until samples brought by future space missions are available on Earth, in situ measurements are the only way to get unaltered samples for analysis. The current most powerful technique for the analysis of organic molecules in extraterrestrial environments is gas chromatography (GC) coupled to mass spectrometry (MS).It was first used in the Viking landers, by the GC-MS experiments which looked for organics on the surface and subsurface of Mars. Viking failed to detect organics at the ppb levels for complex organics. Since the meteorites and interplanetary dust should carry organics to Mars, their absence in the samples analysed by Viking suggests that they are actively destroyed. It is however thought today that organics could be present on the surface at levels below the detection limit of the Viking GC-MS, or that the could be preserved in the Martian subsurface beneath the depth that Viking was able to access. This is why several surface missions are currently planned to investigate Mars to seek again for organics, and GC-MS should be the main experimental device used for this task. Besides Mars, Titan and the comet Churyumov

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  11. Stakeholder acceptance analysis: In-well vapor stripping, in-situ bioremediation, gas membrane separation system (membrane separation)

    SciTech Connect

    Peterson, T.

    1995-12-01

    This document provides stakeholder evaluations on innovative technologies to be used in the remediation of volatile organic compounds from soils and ground water. The technologies evaluated are; in-well vapor stripping, in-situ bioremediation, and gas membrane separation.

  12. Gas chromatography for space exploration : application to the in situ analysis of Titan's atmosphere, comets nucleus and martian soil

    NASA Astrophysics Data System (ADS)

    Sternberg, R.; Szopa, C.; Buch, A.; Mettetal, F.; Coscia, D.; Coll, P.; Cabane, M.; Rodier, C.; Vidal-Madjar, C.; Raulin, F.

    Gas chromatography is one of the most powerful technique for the in situ chemical investigation of extraterrestrial environments Its successful use in past planetary missions to Mars 1976-78 and Venus 1978-85 made it the main method selected for the in situ molecular characterization of the Titan s atmosphere comets and the Martian soil Indeed gas chromatography fully meet the severe constraints required in space instrumentation such as small weight and size low power consumption high mechanical strength and resistance to deep space conditions vacuum cosmic rays This paper presents the gas chromatographic subsystems which have been developed at LISA and SA respectively for the Huygens probe of the Cassini-Huygens mission to Titan 1 the Philae probe of the Rosetta mission to a comet 2 and the future landing probe of the MSL 2009 mission to Mars 3 The coupling of these GC subsystems with pyrolysis and chemical derivatization techniques allows the chemical analysis of a wide range of molecules including non-volatiles complex organics such as aminoacides and nucleobases the search of wich is of particular interest for exobiology The analytical capabilities of these subsystems with a particular emphasis of their exobiological aspects and implications are described 1 G Israel C Szopa F Raulin M Cabane P Coll R Sternberg et al Nature vol438 796-799 2005 2 C Szopa R Sternberg F Raulin and H Rosenbauer PSS 863-877 2003 3 Cabane M P Coll C Szopa G Isra e l F Raulin

  13. Improving the Detection Limit in a Capillary Raman System for In Situ Gas Analysis by Means of Fluorescence Reduction

    PubMed Central

    Rupp, Simone; Off, Andreas; Seitz-Moskaliuk, Hendrik; James, Timothy M.; Telle, Helmut H.

    2015-01-01

    Raman spectroscopy for low-pressure or trace gas analysis is rather challenging, in particular in process control applications requiring trace detection and real-time response; in general, enhancement techniques are required. One possible enhancement approach which enjoys increasing popularity makes use of an internally-reflective capillary as the gas cell. However, in the majority of cases, such capillary systems were often limited in their achievable sensitivity by a significant fluorescence background, which is generated as a consequence of interactions between the laser light and optical glass components in the setup. In order to understand and counteract these problems we have investigated a range of fluorescence-reducing measures, including the rearrangement of optical elements, and the replacement of glass components—including the capillary itself—by metal alternatives. These studies now have led to a capillary setup in which fluorescence is practically eliminated and substantial signal enhancement over standard Raman setups is achieved. With this improved (prototype) setup, detection limits of well below 1 mbar could be obtained in sub-second acquisition times, demonstrating the potential of capillary Raman spectroscopy for real-time, in situ gas sensing and process control applications, down to trace level concentrations. PMID:26378545

  14. GAS TURBINE REHEAT USING IN SITU COMBUSTION

    SciTech Connect

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

    2004-05-17

    In situ reheat is an alternative to traditional gas turbine reheat design in which fuel is fed through airfoils rather than in a bulky discrete combustor separating HP and LP turbines. The goals are to achieve increased power output and/or efficiency without higher emissions. In this program the scientific basis for achieving burnout with low emissions has been explored. In Task 1, Blade Path Aerodynamics, design options were evaluated using CFD in terms of burnout, increase of power output, and possible hot streaking. It was concluded that Vane 1 injection in a conventional 4-stage turbine was preferred. Vane 2 injection after vane 1 injection was possible, but of marginal benefit. In Task 2, Combustion and Emissions, detailed chemical kinetics modeling, validated by Task 3, Sub-Scale Testing, experiments, resulted in the same conclusions, with the added conclusion that some increase in emissions was expected. In Task 4, Conceptual Design and Development Plan, Siemens Westinghouse power cycle analysis software was used to evaluate alternative in situ reheat design options. Only single stage reheat, via vane 1, was found to have merit, consistent with prior Tasks. Unifying the results of all the tasks, a conceptual design for single stage reheat utilizing 24 holes, 1.8 mm diameter, at the trailing edge of vane 1 is presented. A development plan is presented.

  15. Performance and microbial community analysis of the anaerobic reactor with coke oven gas biomethanation and in situ biogas upgrading.

    PubMed

    Wang, Wen; Xie, Li; Luo, Gang; Zhou, Qi; Angelidaki, Irini

    2013-10-01

    A new method for simultaneous coke oven gas (COG) biomethanation and in situ biogas upgrading in anaerobic reactor was developed in this study. The simulated coke oven gas (SCOG) (92% H2 and 8% CO) was injected directly into the anaerobic reactor treating sewage sludge through hollow fiber membrane (HFM). With pH control at 8.0, the added H2 and CO were fully consumed and no negative effects on the anaerobic degradation of sewage sludge were observed. The maximum CH4 content in the biogas was 99%. The addition of SCOG resulted in enrichment and dominance of homoacetogenetic genus Treponema and hydrogenotrophic genus Methanoculleus in the liquid, which indicated that H2 were converted to methane by both direct (hydrogenotrophic methanogenesis) and indirect (homoacetogenesis+aceticlastic methanogenesis) pathways in the liquid. However, the aceticlasitic genus Methanosaeta was dominant for archaea in the biofilm on the HFM, which indicated indirect (homoacetogenesis+aceticlastic methanogenesis) H2 conversion pathway on the biofilm.

  16. In situ ultrahigh vacuum residual gas analyzer 'calibration'

    SciTech Connect

    Malyshev, O. B.; Middleman, K. J.

    2008-11-15

    Knowing the residual gas spectrum is essential for many applications and research in ultrahigh vacuum (UHV). Residual gas analyzers (RGAs) are used for both qualitative and quantitative gas analyses, where the quadrupole mass analyzers are now the most popular. It was found that RGAs supplied by different manufacturers are not necessarily well calibrated for quantitative gas analysis. A procedure applied for in situ RGA 'calibration' against a calibrated UHV total pressure gauge is described in this article. It was found that special attention should be paid to H{sub 2} calibration, as RGAs are usually much more sensitive to H{sub 2} than ionization gauges. The calibration coefficients are quite reproducible in Faraday cup mode, however, using the secondary electron multiplier requires frequent checks of the calibration coefficients. The coefficients obtained for the RGA allow the use of the RGA as an accurate device for gas spectrum analysis.

  17. Application of ion attachment mass spectrometry to evolved gas analysis for in situ monitoring of porous ceramic processing.

    PubMed

    Tsugoshi, Takahisa; Nagaoka, Takaaki; Nakamura, Megumi; Shiokawa, Yoshiro; Watari, Koji

    2006-04-01

    Ion attachment mass spectrometry was applied to evolved gas analysis-mass spectrometry (EGA-MS), generally known as thermogravimetry-mass spectrometry. Characteristic species arising from poly(vinyl alcohol) (PVA) and poly(methyl methacrylate) (PMMA) resin, used as a binder and a porogen, respectively, in the starting materials for porous ceramics, were detected in the mass spectra. The EGA curves of the characteristic mass peaks from PVA and PMMA, when plotted against the programmed temperature, successfully showed the individual pyrolysis behavior of each polymer during the firing process.

  18. In situ bioremediation of chlorinated solvent with natural gas

    SciTech Connect

    Rabold, D.E.

    1996-12-31

    A bioremediation system for the removal of chlorinated solvents from ground water and sediments is described. The system involves the the in-situ injection of natural gas (as a microbial nutrient) through an innovative configuration of horizontal wells.

  19. In Situ Analysis of Gas Generation in Lithium-Ion Batteries with Different Carbonate-Based Electrolytes.

    PubMed

    Teng, Xin; Zhan, Chun; Bai, Ying; Ma, Lu; Liu, Qi; Wu, Chuan; Wu, Feng; Yang, Yusheng; Lu, Jun; Amine, Khalil

    2015-10-21

    Gas generation in lithium-ion batteries is one of the critical issues limiting their safety performance and lifetime. In this work, a set of 900 mAh pouch cells were applied to systematically compare the composition of gases generated from a serial of carbonate-based composite electrolytes, using a self-designed gas analyzing system. Among electrolytes used in this work, the composite γ-butyrolactone/ethyl methyl carbonate (GBL/EMC) exhibited remarkably less gassing because of the electrochemical stability of the GBL, which makes it a promising electrolyte for battery with advanced safety and lifetime.

  20. In Situ Analysis of Gas Generation in Lithium-Ion Batteries with Different Carbonate-Based Electrolytes.

    PubMed

    Teng, Xin; Zhan, Chun; Bai, Ying; Ma, Lu; Liu, Qi; Wu, Chuan; Wu, Feng; Yang, Yusheng; Lu, Jun; Amine, Khalil

    2015-10-21

    Gas generation in lithium-ion batteries is one of the critical issues limiting their safety performance and lifetime. In this work, a set of 900 mAh pouch cells were applied to systematically compare the composition of gases generated from a serial of carbonate-based composite electrolytes, using a self-designed gas analyzing system. Among electrolytes used in this work, the composite γ-butyrolactone/ethyl methyl carbonate (GBL/EMC) exhibited remarkably less gassing because of the electrochemical stability of the GBL, which makes it a promising electrolyte for battery with advanced safety and lifetime. PMID:26417916

  1. Treatment of gas from an in situ conversion process

    SciTech Connect

    Diaz, Zaida; Del Paggio, Alan Anthony; Nair, Vijay; Roes, Augustinus Wilhelmus Maria

    2011-12-06

    A method of producing methane is described. The method includes providing formation fluid from a subsurface in situ conversion process. The formation fluid is separated to produce a liquid stream and a first gas stream. The first gas stream includes olefins. At least the olefins in the first gas stream are contacted with a hydrogen source in the presence of one or more catalysts and steam to produce a second gas stream. The second gas stream is contacted with a hydrogen source in the presence of one or more additional catalysts to produce a third gas stream. The third gas stream includes methane.

  2. Seeking organic compounds on Mars : in situ analysis of organic compounds by Gas Chromatography-Mass Spectrometry on MOMA experiment

    NASA Astrophysics Data System (ADS)

    Buch, A.; Freissinet, C.; Sternberg, R.; Pinnick, V.; Szopa, C.; Coll, P. J.; Rodier, C.; Garnier, C.; Steininger, H.; Moma Team

    2010-12-01

    The search for signs of past or present life is one of the primary goals of future Mars exploratory missions. The Mars Organic Molecule Analyzer (MOMA) experiment of the ExoMars mission (set to launch 2016-2018) is a joint venture by the European Space Agency and NASA to develop a sensitive detector for organics on Mars. MOMA will be one of the main analytical instruments aboard the ExoMars Rover aimed at characterizing possible “signs-of-life molecules” in the Martian environment such as amino acids, carboxylic acids, nucleobases or polycyclic aromatic hydrocarbons (PAHs). With the aim to separate and detect organic compounds from Martian soil, the French MOMA team has built a gas chromatograph able to work in standalone mode by using a TCD detector. The gas chromatograph can also be coupled with an ion trap mass spectrometer developed by the US MOMA team. Moreover, a GC-MS compatible sample processing system (SPS) allowing the extraction and the chemical transformation of the organic compounds from the soil, that fits within space flight conditions, has also been developed. The sample processing is performed in an oven, dedicated to the MOMA experiment containing the solid sample (50-100mg). The internal temperature of oven can be ranged from 20 to 1000 °C which allows for pyrolysis, thermochemolysis or derivatization. The organic extraction step is achieved by using thermodesorption in the range of 100 to 300°C for 0.5 to 5 min. Then, the chemical derivatization and/or thermochemolysis of the extracted compounds is performed directly on the soil with a mixture of MTBSTFA-DMF, TMAH or DMF-DMA solution when enantiomeric separation is required. By decreasing the polarity of the target molecules, this step allows for their volatilization at a temperature below 250°C without any chemical degradation. Once derivatized, the volatile target molecules are trapped in a cold chemical trap and promptly desorbed into the gas chromatograph coupled to the mass

  3. In-Situ Planetary Chemical Analysis

    NASA Technical Reports Server (NTRS)

    Kounaves, S. P.; Buehler, M. G.; Grannan, S. M.; Hecht, M. H.; Kuhlman, K. R.

    2000-01-01

    Both, the search for evidence of life on Mars and the assessment of the Martian environment in respect to its compatibility with human explorers, will require the ability to measure and understand the aqueous chemistry of the Martian regolith. Direct in-situ chemical analysis is the only method by which chemical biosignatures can be reliably recognized and the toxicity of the regolith accurately assessed. Qualitative and quantitative determination of the aqueous ionic constituents and their concentrations is critical in developing kinetic and thermodynamic models that can be used to accurately predict the potential of the past or present Martian geochemical environment to have either generated or still sustain life. In-situ chemical characterization could provide evidence as to whether the chemical composition of the regolith or evaporates in suspected ancient water bodies have been biologically influenced.

  4. In Situ Analysis of the Volatiles in the Lunar Regolith with the Gas Analytical Package Experiment: Calibration of a GCMS Protoype

    NASA Astrophysics Data System (ADS)

    Coscia, David; Szopa, Cyril; Gerasimov, Mikhail; Wurz, Peter; Hofer, Lukas; cabane, Michel; Coll, Patrice; Buch, Arnaud; Fausch, Rico; Sap gir, S. A.; Aseev, Sergei; Zaitsev, Maxim; GAC Team

    2016-10-01

    Volatiles were recently shown to be present at the Lunar pole. They probably come from meteorites and micrometeorites which continuously deliver their material at the surface of the satellite. Thus, their characterisation would enable to better constrain the nature of the species brought by the meteorites to the solar system bodies, evaluate their evolution under Moon surface conditions. Within a few years, it could be done in situ with the Gas Analytical Package experiment onboard the Russian Luna Ressource mission, in part devoted to analyse regolith samples. With this aim, our team proposes an instrumentation to characterize in situ the content of volatiles in the lunar soil and rocks. This instrumentation would provide important reference data about the samples collected. It is based on pyrolysis coupled with gas chromatography and mass spectrometry, and could have the capability to: extract volatile materials (either condensed or present in the minerals) from the solid samples, separate the volatile and analyze their structure for identification and quantification, and analyze isotopic ratios in a certain extent. This instrumentation is based on an inheritance of the GAP instrument that was present onboard the late Phobos-Grunt probe. The instrumentation would be composed of : i. a pyrolyzer capable to heat the samples up to about 1000°C, and developed by IKI (Rus), which is also in charge to the whole instrument (PI M. Gerasimov); ii. a gas chromatograph devoted to separate and detect the volatile species released from the samples, developed by LATMOS and LISA (Fr.) ; iii. a time of flight mass spectrometer for the structural identification of the molecules, developed by the University of Bern (Sw.). This instrumentation should allow the identification of inorganic volatile molecules and small organic molecules (up to about benzene). This communication aims at presenting this instrumentation that should be onboard the Luna Ressource probe to the lunar South

  5. In situ secondary ion mass spectrometry analysis

    SciTech Connect

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

    1993-01-01

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

  6. Two Decades of in situ Halocarbon Trace Gas Measurements

    NASA Astrophysics Data System (ADS)

    Dutton, G.; Nance, J. D.; Elkins, J. W.; Hall, B.; Thompson, T.

    2006-12-01

    Motivated by the signing of the Montreal Protocol in 1987 and interests in greenhouse gases, the NOAA Halocarbons and other Atmospheric Trace Species (HATS) group (now in the ESRL/GMD laboratory) focused on frequently measuring some of the regulated ozone depleting gases such as chlorofluorocarbons (CFC-11 and CFC-12), methyl chloroform (CH3CCl3), and carbon tetrachloride (CCl4). The original HATS in situ program, the Radiatively Important Trace Species (RITS) program, measured these four gases and nitrous oxide (N2O) using gas chromatographic (GC) techniques. The RITS GCs were deployed at the NOAA baseline observatories and a cooperative research station where they remained in operation for the next 13 years. Throughout the 1990s, the HATS in situ and flask programs documented the steady decline in global growth rates of the major chlorinated solvents and chlorofluorocarbons as a result of the Montreal Protocol. Widespread use of the replacement compounds to the now banned CFCs prompted improvements to the HATS in situ program. The RITS instruments were replaced from 1998-2000 by the four-channel Chromatograph for Atmospheric Trace Species (CATS) GCs. In addition to the gases measured by RITS, the CATS GCs added nine compounds including halon-1211, methyl chloride (CH3Cl) and CFC alternatives such as HFC-142b and HCFC-22. Since the RITS instruments have been taken offline, efforts have been focused on finalizing this important data set. A number of calibration scale changes from and improvements with the data reduction algorithms have facilitated comparing and combining the RITS and CATS data sets. In particular, the RITS calibration gas concentration tables were updated to reflect the most recent calibration scale changes. Ratios of calibration gas concentrations were fitted to ratios of RITS system responses to those gases in order to derive a detector response nonlinearity factor for each compound measured. The residuals of these fits were used to

  7. Gas cell for in situ soft X-ray transmission-absorption spectroscopy of materials

    SciTech Connect

    Drisdell, W. S.; Kortright, J. B.

    2014-07-15

    A simple gas cell design, constructed primarily from commercially available components, enables in situ soft X-ray transmission-absorption spectroscopy of materials in contact with gas at ambient temperature. The cell has a minimum X-ray path length of 1 mm and can hold gas pressures up to ∼300 Torr, and could support higher pressures with simple modifications. The design enables cycling between vacuum and gas environments without interrupting the X-ray beam, and can be fully sealed to allow for measurements of air-sensitive samples. The cell can attach to the downstream port of any appropriate synchrotron beamline, and offers a robust and versatile method for in situ measurements of certain materials. The construction and operation of the cell are discussed, as well as sample preparation and proper spectral analysis, illustrated by examples of spectral measurements. Potential areas for improvement and modification for specialized applications are also mentioned.

  8. High Throughput In Situ DDA Analysis of Neuropeptides by Coupling Novel Multiplex Mass Spectrometric Imaging (MSI) with Gas-Phase Fractionation

    NASA Astrophysics Data System (ADS)

    OuYang, Chuanzi; Chen, Bingming; Li, Lingjun

    2015-12-01

    Matrix-assisted laser desorption/ionization (MALDI) mass spectrometric imaging (MSI) is a powerful tool to map the spatial distribution of biomolecules on tissue sections. Recent developments of hybrid MS instruments allow combination of different types of data acquisition by various mass analyzers into a single MSI analysis, which reduces experimental time and sample consumptions. Here, using the well-characterized crustacean nervous system as a test-bed, we explore the utility of high resolution and accurate mass (HRAM) MALDI Orbitrap platform for enhanced in situ characterization of the neuropeptidome with improved chemical information. Specifically, we report on a multiplex-MSI method, which combines HRAM MSI with data dependent acquisition (DDA) tandem MS analysis in a single experiment. This method enables simultaneous mapping of neuropeptide distribution, sequence validation, and novel neuropeptide discovery in crustacean neuronal tissues. To enhance the dynamic range and efficiency of in situ DDA, we introduced a novel approach of fractionating full m/z range into several sub-mass ranges and embedding the setup using the multiplex-DDA-MSI scan events to generate pseudo fractionation before MS/MS scans. The division of entire m/z into multiple segments of m/z sub-ranges for MS interrogation greatly decreased the complexity of molecular species from tissue samples and the heterogeneity of the distribution and variation of intensities of m/z peaks. By carefully optimizing the experimental conditions such as the dynamic exclusion, the multiplex-DDA-MSI approach demonstrates better performance with broader precursor coverage, less biased MS/MS scans towards high abundance molecules, and improved quality of tandem mass spectra for low intensity molecular species.

  9. In situ Gas Conditioning in Fuel Reforming for Hydrogen Generation

    SciTech Connect

    Bandi, A.; Specht, M.; Sichler, P.; Nicoloso, N.

    2002-09-20

    The production of hydrogen for fuel cell applications requires cost and energy efficient technologies. The Absorption Enhanced Reforming (AER), developed at ZSW with industrial partners, is aimed to simplify the process by using a high temperature in situ CO2 absorption. The in situ CO2 removal results in shifting the steam reforming reaction equilibrium towards increased hydrogen concentration (up to 95 vol%). The key part of the process is the high temperature CO2 absorbent. In this contribution results of Thermal Gravimetric Analysis (TGA) investigations on natural minerals, dolomites, silicates and synthetic absorbent materials in regard of their CO2 absorption capacity and absorption/desorption cyclic stability are presented and discussed. It has been found that the inert parts of the absorbent materials have a structure stabilizing effect, leading to an improved cyclic stability of the materials.

  10. Preliminary development of a wall-less gas-flow proportional counter for in-situ field analysis of nuclear contamination in soil

    SciTech Connect

    Bush, S.P.; Hamby, D.M.; Martin, J.E.

    1997-03-01

    This study resulted in the design, construction and testing of a gas flow proportional counter for in-situ determination of soil contamination. The uniqueness of this detector is the screened material used for the cathode. A Pu-239 source of 0.006 {micro}Ci was mounted to the outside of the cathode to simulate radioactive soil. The detector probe was placed into a laboratory mock-up and tested to determine operating voltage, efficiency and energy resolution. Two gas flow proportional counters were built and tested. The detectors are cylindrical, each with a radius of 1.905 cm, having an anode wire with a radius of 0.0038 cm. The length of the smaller detector S anode was 2.54 cm, and the length of the larger detector S anode was 7.64 cm. Therefore, the active volumes were 28.96 cm{sup 3} and 87.10 cm{sup 3}, respectively, for the small and large detector. An operating voltage of 1975 volts was determined to be sufficient for both detectors. The average efficiency was 2.59 {+-} 0.12% and 76.71 {+-} 10.81% for the small volume and large volume detectors, respectively. The average energy resolution for the low-energy peak of the small detector was 4.24 {+-} 1.28% and for the large-energy peak was 1.37 {+-} 0.66%. The large detectors energy resolution was 17.75 {+-} 3.74%. The smaller detector, with better energy resolution, exhibited a bi-modal spectrum, whereas the larger detector S spectrum centered around a single broad peak.

  11. Resonant optical transducers for in-situ gas detection

    DOEpatents

    Bond, Tiziana C; Cole, Garrett; Goddard, Lynford

    2016-06-28

    Configurations for in-situ gas detection are provided, and include miniaturized photonic devices, low-optical-loss, guided-wave structures and state-selective adsorption coatings. High quality factor semiconductor resonators have been demonstrated in different configurations, such as micro-disks, micro-rings, micro-toroids, and photonic crystals with the properties of very narrow NIR transmission bands and sensitivity up to 10.sup.-9 (change in complex refractive index). The devices are therefore highly sensitive to changes in optical properties to the device parameters and can be tunable to the absorption of the chemical species of interest. Appropriate coatings applied to the device enhance state-specific molecular detection.

  12. Foreword: In situ gas surface interactions: approaching realistic conditions

    NASA Astrophysics Data System (ADS)

    Lundgren, Edvin; Over, Herbert

    2008-03-01

    This special issue is devoted to the application of in situ surface-sensitive techniques in the elucidation of catalysed reactions at (model) catalyst surfaces. Both reaction intermediates and the nature of the catalytically active phase are the targets of these investigations. In situ surface science techniques are also used to study the interaction of water with surfaces under realistic conditions. Since 80% of all technical chemicals are manufactured by utilizing (heterogeneous) catalysis, scientific understanding and technological development of catalysis are of central practical importance in modern society [1]. Heterogeneously catalysed reactions take place at the gas/solid interface. Therefore one of the major topics in surface chemistry and physics is closely related to heterogeneous catalysis, with the aim of developing novel catalysts and to improve catalysts' performances on the basis of atomic scale based knowledge. Despite the economical and environmental rewards—if such a goal is achieved—and despite 40 years of intensive research, practical catalysis is still safely in a black box: the reactivity and selectivity of a catalyst are commercially still optimized on a trial and error basis, applying the high throughput screening approach. The reason for this discrepancy between ambition and reality lies in the inherent complexity of the catalytic system, consisting of the working catalyst and the interaction of the catalyst with the reactant mixture. Practical (solid) catalysts consist of metal or oxide nanoparticles which are dispersed and stabilized on a support and which may be promoted by means of additives. These particles catalyse a reaction in pressures as high as 100 bar. Practical catalysis is in general considered to be far too complex for gaining atomic-scale understanding of the mechanism of the catalysed reaction of an industrial catalyst during its operation. Therefore it has been necessary to introduce idealization and simplification of

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  14. Direct comparative study on the energy level alignments in unoccupied/occupied states of organic semiconductor/electrode interface by constructing in-situ photoemission spectroscopy and Ar gas cluster ion beam sputtering integrated analysis system

    SciTech Connect

    Yun, Dong-Jin Chung, JaeGwan; Kim, Yongsu; Park, Sung-Hoon; Kim, Seong-Heon; Heo, Sung

    2014-10-21

    Through the installation of electron gun and photon detector, an in-situ photoemission and damage-free sputtering integrated analysis system is completely constructed. Therefore, this system enables to accurately characterize the energy level alignments including unoccupied/occupied molecular orbital (LUMO/HOMO) levels at interface region of organic semiconductor/electrode according to depth position. Based on Ultraviolet Photoemission Spectroscopy (UPS), Inverse Photoemission Spectroscopy (IPES), and reflective electron energy loss spectroscopy, the occupied/unoccupied state of in-situ deposited Tris[4-(carbazol-9-yl)phenyl]amine (TCTA) organic semiconductors on Au (E{sub LUMO}: 2.51 eV and E{sub HOMO}: 1.35 eV) and Ti (E{sub LUMO}: 2.19 eV and E{sub HOMO}: 1.69 eV) electrodes are investigated, and the variation of energy level alignments according to work function of electrode (Au: 4.81 eV and Ti: 4.19 eV) is clearly verified. Subsequently, under the same analysis condition, the unoccupied/occupied states at bulk region of TCTA/Au structures are characterized using different Ar gas cluster ion beam (Ar GCIB) and Ar ion sputtering processes, respectively. While the Ar ion sputtering process critically distorts both occupied and unoccupied states in UPS/IPES spectra, the Ar GCIB sputtering process does not give rise to damage on them. Therefore, we clearly confirm that the in-situ photoemission spectroscopy in combination with Ar GCIB sputtering allows of investigating accurate energy level alignments at bulk/interface region as well as surface region of organic semiconductor/electrode structure.

  15. NMR apparatus for in situ analysis of fuel cells

    SciTech Connect

    Gerald, II, Rex E; Rathke, Jerome W

    2012-11-13

    The subject apparatus is a fuel cell toroid cavity detector for in situ analysis of samples through the use of nuclear magnetic resonance. The toroid cavity detector comprises a gas-tight housing forming a toroid cavity where the housing is exposed to an externally applied magnetic field B.sub.0 and contains fuel cell component samples to be analyzed. An NMR spectrometer is electrically coupled and applies a radiofrequency excitation signal pulse to the detector to produce a radiofrequency magnetic field B.sub.1 in the samples and in the toroid cavity. Embedded coils modulate the static external magnetic field to provide a means for spatial selection of the recorded NMR signals.

  16. Enantiomeric separation of volatile organics by gas chromatography for the in situ analysis of extraterrestrial materials: kinetics and thermodynamics investigation of various chiral stationary phases.

    PubMed

    Freissinet, C; Buch, A; Szopa, C; Sternberg, R

    2013-09-01

    The performances of several commercial chiral capillary columns have been evaluated with the aim of determining the one most suitable for enantiomeric separation in a gas chromatograph onboard a space probe. We compared the GC-MS response of three capillary columns coated with different chiral stationary phases (CSP) using volatile chiral organic molecules which are potential markers of a prebiotic organic chemistry. The three different chiral capillary columns are Chirasil-Val, with an amino acid derivative CSP, ChiralDex-β-PM, with a CSP composed of dissolved permethylated β-cyclodextrins in polysiloxane, and Chirasil-Dex, with a CSP made of modified cyclodextrins chemically bonded to the polysiloxane backbone. Both kinetics and thermodynamics studies have been carried out to evaluate the chiral recognition potential in these different types of columns. The thermodynamic parameters also allow a better understanding of the driving forces affecting the retention and separation of the enantiomers. The Chirasil-Dex-CSP displays the best characteristics for an optimal resolution of the chiral compounds, without preliminary derivatization. This CSP had been chosen to be the only chiral column in the Sample Analysis at Mars (SAM) experiment onboard the current Mars Science Laboratory (MSL) mission, and is also part of the Mars Organic Molecules Analyzer (MOMA) gas chromatograph onboard the next Martian mission ExoMars. The use of this column could also be extended to all space missions aimed at studying chirality in space. PMID:23921265

  17. Enantiomeric separation of volatile organics by gas chromatography for the in situ analysis of extraterrestrial materials: kinetics and thermodynamics investigation of various chiral stationary phases.

    PubMed

    Freissinet, C; Buch, A; Szopa, C; Sternberg, R

    2013-09-01

    The performances of several commercial chiral capillary columns have been evaluated with the aim of determining the one most suitable for enantiomeric separation in a gas chromatograph onboard a space probe. We compared the GC-MS response of three capillary columns coated with different chiral stationary phases (CSP) using volatile chiral organic molecules which are potential markers of a prebiotic organic chemistry. The three different chiral capillary columns are Chirasil-Val, with an amino acid derivative CSP, ChiralDex-β-PM, with a CSP composed of dissolved permethylated β-cyclodextrins in polysiloxane, and Chirasil-Dex, with a CSP made of modified cyclodextrins chemically bonded to the polysiloxane backbone. Both kinetics and thermodynamics studies have been carried out to evaluate the chiral recognition potential in these different types of columns. The thermodynamic parameters also allow a better understanding of the driving forces affecting the retention and separation of the enantiomers. The Chirasil-Dex-CSP displays the best characteristics for an optimal resolution of the chiral compounds, without preliminary derivatization. This CSP had been chosen to be the only chiral column in the Sample Analysis at Mars (SAM) experiment onboard the current Mars Science Laboratory (MSL) mission, and is also part of the Mars Organic Molecules Analyzer (MOMA) gas chromatograph onboard the next Martian mission ExoMars. The use of this column could also be extended to all space missions aimed at studying chirality in space.

  18. In situ vitrification large-scale operational acceptance test analysis

    SciTech Connect

    Buelt, J.L.; Carter, J.G.

    1986-05-01

    A thermal treatment process is currently under study to provide possible enhancement of in-place stabilization of transuranic and chemically contaminated soil sites. The process is known as in situ vitrification (ISV). In situ vitrification is a remedial action process that destroys solid and liquid organic contaminants and incorporates radionuclides into a glass-like material that renders contaminants substantially less mobile and less likely to impact the environment. A large-scale operational acceptance test (LSOAT) was recently completed in which more than 180 t of vitrified soil were produced in each of three adjacent settings. The LSOAT demonstrated that the process conforms to the functional design criteria necessary for the large-scale radioactive test (LSRT) to be conducted following verification of the performance capabilities of the process. The energy requirements and vitrified block size, shape, and mass are sufficiently equivalent to those predicted by the ISV mathematical model to confirm its usefulness as a predictive tool. The LSOAT demonstrated an electrode replacement technique, which can be used if an electrode fails, and techniques have been identified to minimize air oxidation, thereby extending electrode life. A statistical analysis was employed during the LSOAT to identify graphite collars and an insulative surface as successful cold cap subsidence techniques. The LSOAT also showed that even under worst-case conditions, the off-gas system exceeds the flow requirements necessary to maintain a negative pressure on the hood covering the area being vitrified. The retention of simulated radionuclides and chemicals in the soil and off-gas system exceeds requirements so that projected emissions are one to two orders of magnitude below the maximum permissible concentrations of contaminants at the stack.

  19. A (S)TEM Gas Cell Holder with Localized Laser Heating for In Situ Experiments

    SciTech Connect

    Mehraeen, Shareghe; McKeown, Joseph T.; Deshmukh, Pushkarraj V.; Evans, James E.; Abellan, Patricia; Xu, Pinghong; Reed, Bryan W.; Taheri, Mitra L.; Fischione, Paul E.; Browning, Nigel D.

    2013-03-04

    We report that the advent of aberration correction for transmission electron microscopy has transformed atomic resolution imaging into a nearly routine technique for structural analysis. Now an emerging frontier in electron microscopy is the development of in situ capabilities to observe reactions at atomic resolution in real time and within realistic environments. Here we present a new in situ gas cell holder that is designed for compatibility with a wide variety of sample type (i.e., dimpled 3-mm discs, standard mesh grids, various types of focused ion beam lamellae attached to half grids). Its capabilities include localized heating and precise control of the gas pressure and composition while simultaneously allowing atomic resolution imaging at ambient pressure. The results show that 0.25-nm lattice fringes are directly visible for nanoparticles imaged at ambient pressure with gas path lengths up to 20 μm. Additionally, we quantitatively demonstrate that while the attainable contrast and resolution decrease with increasing pressure and gas path length, resolutions better than 0.2 nm should be accessible at ambient pressure with gas path lengths less than the 15 μm utilized for these experiments.

  20. An in situ method for real-time monitoring of soil gas diffusivity

    NASA Astrophysics Data System (ADS)

    Laemmel, Thomas; Maier, Martin; Schack-Kirchner, Helmer; Lang, Friederike

    2016-04-01

    Soil aeration is an important factor for the biogeochemistry of soils. Generally, gas exchange between soil and atmosphere is assumed to be governed by molecular diffusion and by this way fluxes can be calculated using by Fick's Law. The soil gas diffusion coefficient DS represents the proportional factor between the gas flux and the gas concentration gradient in the soil and reflects the ability of the soil to "transport passively" gas through the soil. One common way to determine DS is taking core samples in the field and measuring DS in the lab. Unfortunately this method is destructive and laborious and it can only reflect a small fraction of the whole soil. As a consequence, uncertainty about the resulting effective diffusivity on the profile scale, i.e. the real aeration status remains. We developed a method to measure and monitor DS in situ. The set-up consists of a custom made gas sampling device, the continuous injection of an inert tracer gas and inverse gas transport modelling in the soil. The gas sampling device has seven sampling depths (from 0 to -43 cm of depth) and can be easily installed into vertical holes drilled by an auger, which allows for fast installation of the system. Helium (He) as inert tracer gas was injected continuously at the lower end of the device. The resulting steady state distribution of He was used to deduce the DS depth distribution of the soil. For Finite Element Modeling of the gas-sampling-device/soil system the program COMSOL was used. We tested our new method both in the lab and in a field study and compared the results with a reference lab method using soil cores. DS profiles obtained by our in-situ method were consistent with DS profiles determined based on soil core analyses. Soil gas profiles could be measured with a temporal resolution of 30 minutes. During the field study, there was an important rain event and we could monitor the decrease in soil gas diffusivity in the top soil due to water infiltration. The effect

  1. Foreword: In situ gas surface interactions: approaching realistic conditions

    NASA Astrophysics Data System (ADS)

    Lundgren, Edvin; Over, Herbert

    2008-03-01

    This special issue is devoted to the application of in situ surface-sensitive techniques in the elucidation of catalysed reactions at (model) catalyst surfaces. Both reaction intermediates and the nature of the catalytically active phase are the targets of these investigations. In situ surface science techniques are also used to study the interaction of water with surfaces under realistic conditions. Since 80% of all technical chemicals are manufactured by utilizing (heterogeneous) catalysis, scientific understanding and technological development of catalysis are of central practical importance in modern society [1]. Heterogeneously catalysed reactions take place at the gas/solid interface. Therefore one of the major topics in surface chemistry and physics is closely related to heterogeneous catalysis, with the aim of developing novel catalysts and to improve catalysts' performances on the basis of atomic scale based knowledge. Despite the economical and environmental rewards—if such a goal is achieved—and despite 40 years of intensive research, practical catalysis is still safely in a black box: the reactivity and selectivity of a catalyst are commercially still optimized on a trial and error basis, applying the high throughput screening approach. The reason for this discrepancy between ambition and reality lies in the inherent complexity of the catalytic system, consisting of the working catalyst and the interaction of the catalyst with the reactant mixture. Practical (solid) catalysts consist of metal or oxide nanoparticles which are dispersed and stabilized on a support and which may be promoted by means of additives. These particles catalyse a reaction in pressures as high as 100 bar. Practical catalysis is in general considered to be far too complex for gaining atomic-scale understanding of the mechanism of the catalysed reaction of an industrial catalyst during its operation. Therefore it has been necessary to introduce idealization and simplification of

  2. In-situ Data Analysis Framework for ACME Land Simulations

    NASA Astrophysics Data System (ADS)

    Wang, D.; Yao, C.; Jia, Y.; Steed, C.; Atchley, S.

    2015-12-01

    The realistic representation of key biogeophysical and biogeochemical functions is the fundamental of process-based ecosystem models. Investigating the behavior of those ecosystem functions within real-time model simulation can be a very challenging due to the complex of both model and software structure of an environmental model, such as the Accelerated Climate Model for Energy (ACME) Land Model (ALM). In this research, author will describe the urgent needs and challenges for in-situ data analysis for ALM simulations, and layouts our methods/strategies to meet these challenges. Specifically, an in-situ data analysis framework is designed to allow users interactively observe the biogeophyical and biogeochemical process during ALM simulation. There are two key components in this framework, automatically instrumented ecosystem simulation, in-situ data communication and large-scale data exploratory toolkit. This effort is developed by leveraging several active projects, including scientific unit testing platform, common communication interface and extreme-scale data exploratory toolkit. Authors believe that, based on advanced computing technologies, such as compiler-based software system analysis, automatic code instrumentation, and in-memory data transport, this software system provides not only much needed capability for real-time observation and in-situ data analytics for environmental model simulation, but also the potentials for in-situ model behavior adjustment via simulation steering.

  3. The development of an electrochemical technique for in situ calibrating of combustible gas detectors

    NASA Technical Reports Server (NTRS)

    Shumar, J. W.; Lantz, J. B.; Schubert, F. H.

    1976-01-01

    A program to determine the feasibility of performing in situ calibration of combustible gas detectors was successfully completed. Several possible techniques for performing the in situ calibration were proposed. The approach that showed the most promise involved the use of a miniature water vapor electrolysis cell for the generation of hydrogen within the flame arrestor of a combustible gas detector to be used for the purpose of calibrating the combustible gas detectors. A preliminary breadboard of the in situ calibration hardware was designed, fabricated and assembled. The breadboard equipment consisted of a commercially available combustible gas detector, modified to incorporate a water vapor electrolysis cell, and the instrumentation required for controlling the water vapor electrolysis and controlling and calibrating the combustible gas detector. The results showed that operation of the water vapor electrolysis at a given current density for a specific time period resulted in the attainment of a hydrogen concentration plateau within the flame arrestor of the combustible gas detector.

  4. Development of an in situ calibration technique for combustible gas detectors

    NASA Technical Reports Server (NTRS)

    Shumar, J. W.; Wynveen, R. A.; Lance, N., Jr.; Lantz, J. B.

    1977-01-01

    This paper describes the development of an in situ calibration procedure for combustible gas detectors (CGD). The CGD will be a necessary device for future space vehicles as many subsystems in the Environmental Control/Life Support System utilize or produce hydrogen (H2) gas. Existing calibration techniques are time-consuming and require support equipment such as an environmental chamber and calibration gas supply. The in situ calibration procedure involves utilization of a water vapor electrolysis cell for the automatic in situ generation of a H2/air calibration mixture within the flame arrestor of the CGD. The development effort concluded with the successful demonstration of in situ span calibrations of a CGD.

  5. In Situ Control of Gas Flow by Modification of Gas-Solid Interactions

    NASA Astrophysics Data System (ADS)

    Seo, Dongjin; Ducker, William A.

    2013-10-01

    The boundary condition for gas flow at the solid-gas interface can be altered by in situ control of the state of a thin film adsorbed to the solid. A monolayer of ocatadecyltrichlorosilane (OTS) reversibly undergoes a meltinglike transition. When the temperature of an OTS-coated particle and plate is moved through the range of OTS “melting” temperatures, there is a change in the lubrication force between the particle and plate in 1 atm of nitrogen gas. This change is interpreted in terms of a change in the flow of gas mediated by the slip length and tangential momentum accommodation coefficient (TMAC). There is a minimum in slip length (290 nm) at 18°C, which corresponds to a maximum in TMAC (0.44). The slip length increases to 590 nm at 40°C which corresponds to a TMAC of 0.25. We attribute the decrease in TMAC with increasing temperature to a decrease in roughness of the monolayer on melting, which allows a higher fraction of specular gas reflections, thereby conserving tangential gas momentum. The importance of this work is that it demonstrates the ability to control gas flow simply by altering the interface for fixed geometry and gas properties.

  6. In situ analysis of martian regolith with the SAM experiment during the first mars year of the MSL mission: Identification of organic molecules by gas chromatography from laboratory measurements

    NASA Astrophysics Data System (ADS)

    Millan, M.; Szopa, C.; Buch, A.; Coll, P.; Glavin, D. P.; Freissinet, C.; Navarro-Gonzalez, R.; François, P.; Coscia, D.; Bonnet, J. Y.; Teinturier, S.; Cabane, M.; Mahaffy, P. R.

    2016-09-01

    The Sample Analysis at Mars (SAM) instrument onboard the Curiosity rover, is specifically designed for in situ molecular and isotopic analyses of martian surface materials and atmosphere. It contributes to the Mars Science Laboratory (MSL) missions primary scientific goal to characterize the potential past, present or future habitability of Mars. In all of the analyses of solid samples delivered to SAM so far, chlorinated organic compounds have been detected above instrument background levels and identified by gas chromatography coupled to mass spectrometry (GC-MS) (Freissinet et al., 2015; Glavin et al., 2013). While some of these may originate from reactions between oxychlorines and terrestrial organic carbon present in the instrument background (Glavin et al., 2013), others have been demonstrated to originate from indigenous organic carbon present in samples (Freissinet et al., 2015). We present here laboratory calibrations that focused on the analyses performed with the MXT-CLP GC column (SAM GC-5 channel) used for nearly all of the GC-MS analyses of the martian soil samples carried out with SAM to date. Complementary to the mass spectrometric data, gas chromatography allows us to separate and identify the species analyzable in a nominal SAM-GC run time of about 21 min. To characterize the analytical capabilities of this channel within the SAM Flight Model (FM) operating conditions on Mars, and their implications on the detection of organic matter, it is required to perform laboratory experimental tests and calibrations on spare model components. This work assesses the SAM flight GC-5 column efficiency, confirms the identification of the molecules based on their retention time, and enables a better understanding of the behavior of the SAM injection trap (IT) and its release of organic molecules. This work will enable further optimization of the SAM-GC runs for additional samples to be analyzed during the MSL mission.

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

    NASA Technical Reports Server (NTRS)

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

    1972-01-01

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

  8. Estimates of in situ gas hydrate concentration from resistivity monitoring of gas hydrate bearing sediments during temperature equilibration

    USGS Publications Warehouse

    Riedel, M.; Long, P.E.; Collett, T.S.

    2006-01-01

    As part of Ocean Drilling Program Leg 204 at southern Hydrate Ridge off Oregon we have monitored changes in sediment electrical resistivity during controlled gas hydrate dissociation experiments. Two cores were used, each filled with gas hydrate bearing sediments (predominantly mud/silty mud). One core was from Site 1249 (1249F-9H3), 42.1 m below seafloor (mbsf) and the other from Site 1248 (1248C-4X1), 28.8 mbsf. At Site 1247, a third experiment was conducted on a core without gas hydrate (1247B-2H1, 3.6 mbsf). First, the cores were imaged using an infra-red (IR) camera upon recovery to map the gas hydrate occurrence through dissociation cooling. Over a period of several hours, successive runs on the multi-sensor track (includes sensors for P-wave velocity, resistivity, magnetic susceptibility and gamma-ray density) were carried out complemented by X-ray imaging on core 1249F-9H3. After complete equilibration to room temperature (17-18??C) and complete gas hydrate dissociation, the final measurement of electrical resistivity was used to calculate pore-water resistivity and salinities. The calculated pore-water freshening after dissociation is equivalent to a gas hydrate concentration in situ of 35-70% along core 1249F-9H3 and 20-35% for core 1248C-4X1 assuming seawater salinity of in situ pore fluid. Detailed analysis of the IR scan, X-ray images and split-core photographs showed the hydrate mainly occurred disseminated throughout the core. Additionally, in core 1249F-9H3, a single hydrate filled vein, approximately 10 cm long and dipping at about 65??, was identified. Analyses of the logging-while-drilling (LWD) resistivity data revealed a structural dip of 40-80?? in the interval between 40 and 44 mbsf. We further analyzed all resistivity data measured on the recovered core during Leg 204. Generally poor data quality due to gas cracks allowed analyses to be carried out only at selected intervals at Sites 1244, 1245, 1246, 1247, 1248, 1249, and 1252. With a few

  9. CO2 Storage and Enhance Gas Recovery from Shales: Insights from In Situ Experiments

    NASA Astrophysics Data System (ADS)

    Schaef, T.; McGrail, P.; Miller, Q. R.; Glezakou, V.; Loring, J. S.

    2012-12-01

    Recent developments in hydraulic fracturing technologies have provided a basis for dramatic increases in natural gas production from shale and tight gas reservoirs. GIS data analysis shows that approximately 60% of U.S. stationary CO2 emission sources are within 50 miles of a currently operating or potential shale gas play. Those emission sources represent a potential supply of CO2 to support enhanced gas recovery operations to extend the economic production life of these shale gas fields. Conservative estimates of the CO2 storage capacity in these depleted shale gas reservoirs are around 10 GtCO2 potentially producing up to an additional 100 Tcf of gas. Hence, there is a critical need to better understand the fundamental factors controlling CO2 storage and secondary gas production in shales. Mineralogy of shale formations are complicated, often times containing varying amounts of different clay minerals (illite, kaolinite, chlorite, and montmorillonite) carbonates (calcite, siderite, and dolomite), feldspar, quartz, gypsum, and pyrite. Interactions of these minerals with wet scCO2 are mostly unknown and will ultimately control injectivity, methane production, and CO2 storage capacity through mineral volume changes. To investigate the interactions between important clay minerals and wet scCO2, we have conducted a series of experiments exposing selected clay minerals to scCO2 containing variable amounts of dissolved water. Observations by in situ XRD indicate the montmorillonite structure contracts when in contact with dry scCO2. Expansion is observed when the same mineral is exposed to wet scCO2. Degrees of expansion and contraction are related to total dissolved water content in the scCO2 and the amount of water in the interlayer and type of interlayer cation. Other clays such as kaolinite, chlorite, and illite appear stable and undergo no observable structural change during exposure to scCO2. Experiments are in progress with in situ optical spectroscopic probes

  10. Gas Turbine Reheat Using In-Situ Combustion

    SciTech Connect

    T.E. Lippert; D.M. Bachovchin

    2004-03-31

    Siemens Westinghouse Power Corporation (SWPC) is developing in-situ reheat (fuel injection via airfoil injection) as a means for increasing cycle efficiency and power output, with possibly reduced emissions. In addition to kinetic modeling and experimental task, CFD modeling (by Texas A&M) of airfoil injection and its effects on blade aerodynamics and turbine performance. This report discusses validation of the model against single-vane combustion test data from Siemens Westinghouse, and parametric studies of injection reheat in a modern turbine. The best location for injection is at the trailing edge of the inlet guide vane. Combustion is incomplete at trailing edges of subsequent vanes. Recommendations for further development are presented.

  11. Gas Turbine Reheat Using In-Situ Combustion

    SciTech Connect

    Newby, R. A.; Bachovchin, D. M.; Lippert, T. E.

    2004-04-29

    Siemens Westinghouse Power Corporation (SWPC) is developing in-situ reheat (fuel injection via airfoil injection) as a means for increasing cycle efficiency and power output, with possibly reduced emissions. This report discusses engineering cycle evaluations on various reheat approaches, using GateCycle and ChemCad software simulations of typical F-class and G-class engines, modified for alternative reheat cycles. The conclusion that vane 1 reheat offers the most advantageous design agrees with the conclusions of the detailed chemical kinetics (Task 2) as verified by high temperature testing (Task 3) and Blade path CFD (Task 1) tasks. The second choice design option (vane 2 reheat after vane 1 reheat) is also validated in all tasks. A conceptual design and next recommended development tasks are presented.

  12. Gas seal for an in situ oil shale retort and method of forming thermal barrier

    DOEpatents

    Burton, III, Robert S.

    1982-01-01

    A gas seal is provided in an access drift excavated in a subterranean formation containing oil shale. The access drift is adjacent an in situ oil shale retort and is in gas communication with the fragmented permeable mass of formation particles containing oil shale formed in the in situ oil shale retort. The mass of formation particles extends into the access drift, forming a rubble pile of formation particles having a face approximately at the angle of repose of fragmented formation. The gas seal includes a temperature barrier which includes a layer of heat insulating material disposed on the face of the rubble pile of formation particles and additionally includes a gas barrier. The gas barrier is a gas-tight bulkhead installed across the access drift at a location in the access drift spaced apart from the temperature barrier.

  13. Trace Gas Emission from in-Situ Denitrifying Bioreactors

    NASA Astrophysics Data System (ADS)

    Pluer, W.; Walter, M. T.; Geohring, L.

    2014-12-01

    Despite decades of concerted effort to mitigate nonpoint source nitrate (NO3-) pollution from agricultural lands, these efforts have not been sufficient to arrest eutrophication. A primary process for removing excess NO3- from water is denitrification, where denitrifying bacteria use NO3- for respiration in the absence of oxygen. Denitrification results in reduced forms of nitrogen, often dinitrogen gas (N2) but also nitrous oxide (N2O), an aggressive greenhouse gas. A promising solution to NO3- pollution is to intercept agricultural discharges with denitrifying bioreactors (DNBRs). DNBRs provide conditions ideal for denitrifiers: an anaerobic environment, sufficient organic matter, and excess NO3-. These conditions are also ideal for methanogens, which produce methane (CH4), another harmful trace gas. While initial results from bioreactor studies show that they can cost-effectively remove NO3-, trace gas emissions are an unintended consequence. This study's goal was to determine how bioreactor design promotes denitrification while limiting trace gas production. Reactor inflow and outflow water samples were tested for nutrients, including NO3-, and dissolved inflow and outflow gas samples were tested for N2O and CH4. NO3- reduction and trace gas production were evaluated at various residence times, pHs, and inflow NO3- concentrations in field and lab-scale reactors. Low NO3- reduction indicated conditions that stressed denitrifying bacteria while high reductions indicated designs that optimized pollutant treatment for water quality. Several factors influenced high N2O, suggesting non-ideal conditions for the final step of complete denitrification. High CH4 emissions pointed to reactor media choice for discouraging methanogens, which may remove competition with denitrifiers. It is critical to understand all of potential impacts that DNBRs may have, which means identifying processes and design specifications that may affect them.

  14. Sour gas injection for use with in situ heat treatment

    DOEpatents

    Fowler, Thomas David

    2009-11-03

    Systems, methods, and heaters for treating a subsurface formation are described herein. At least one method for providing acidic gas to a subsurface formation is described herein. The method may include providing heat from one or more heaters to a portion of a subsurface formation; producing fluids that include one or more acidic gases from the formation using a heat treatment process. At least a portion of one of the acidic gases may be introduced into the formation, or into another formation, through one or more wellbores at a pressure below a lithostatic pressure of the formation in which the acidic gas is introduced.

  15. In situ structural analysis of the Yersinia enterocolitica injectisome.

    PubMed

    Kudryashev, Mikhail; Stenta, Marco; Schmelz, Stefan; Amstutz, Marlise; Wiesand, Ulrich; Castaño-Díez, Daniel; Degiacomi, Matteo T; Münnich, Stefan; Bleck, Christopher Ke; Kowal, Julia; Diepold, Andreas; Heinz, Dirk W; Dal Peraro, Matteo; Cornelis, Guy R; Stahlberg, Henning

    2013-01-01

    Injectisomes are multi-protein transmembrane machines allowing pathogenic bacteria to inject effector proteins into eukaryotic host cells, a process called type III secretion. Here we present the first three-dimensional structure of Yersinia enterocolitica and Shigella flexneri injectisomes in situ and the first structural analysis of the Yersinia injectisome. Unexpectedly, basal bodies of injectisomes inside the bacterial cells showed length variations of 20%. The in situ structures of the Y. enterocolitica and S. flexneri injectisomes had similar dimensions and were significantly longer than the isolated structures of related injectisomes. The crystal structure of the inner membrane injectisome component YscD appeared elongated compared to a homologous protein, and molecular dynamics simulations documented its elongation elasticity. The ring-shaped secretin YscC at the outer membrane was stretched by 30-40% in situ, compared to its isolated liposome-embedded conformation. We suggest that elasticity is critical for some two-membrane spanning protein complexes to cope with variations in the intermembrane distance. DOI:http://dx.doi.org/10.7554/eLife.00792.001. PMID:23908767

  16. In situ structural analysis of the Yersinia enterocolitica injectisome

    PubMed Central

    Kudryashev, Mikhail; Stenta, Marco; Schmelz, Stefan; Amstutz, Marlise; Wiesand, Ulrich; Castaño-Díez, Daniel; Degiacomi, Matteo T; Münnich, Stefan; Bleck, Christopher KE; Kowal, Julia; Diepold, Andreas; Heinz, Dirk W; Dal Peraro, Matteo; Cornelis, Guy R; Stahlberg, Henning

    2013-01-01

    Injectisomes are multi-protein transmembrane machines allowing pathogenic bacteria to inject effector proteins into eukaryotic host cells, a process called type III secretion. Here we present the first three-dimensional structure of Yersinia enterocolitica and Shigella flexneri injectisomes in situ and the first structural analysis of the Yersinia injectisome. Unexpectedly, basal bodies of injectisomes inside the bacterial cells showed length variations of 20%. The in situ structures of the Y. enterocolitica and S. flexneri injectisomes had similar dimensions and were significantly longer than the isolated structures of related injectisomes. The crystal structure of the inner membrane injectisome component YscD appeared elongated compared to a homologous protein, and molecular dynamics simulations documented its elongation elasticity. The ring-shaped secretin YscC at the outer membrane was stretched by 30–40% in situ, compared to its isolated liposome-embedded conformation. We suggest that elasticity is critical for some two-membrane spanning protein complexes to cope with variations in the intermembrane distance. DOI: http://dx.doi.org/10.7554/eLife.00792.001 PMID:23908767

  17. Gas Turbine Reheat Using In-Situ Combustion

    SciTech Connect

    D.M. Bachovchin; T.E. Lippert

    2004-04-30

    Gas turbine reheat is a well-known technique for increasing the power output of gas turbine, as well as the efficiency in combined cycle operation with higher heat recovery inlet temperatures. The technique also could allow development of an advanced high efficiency turbine with an additional stage, but without a higher inlet temperature. A novel reheat approach, with fuel added via internal passages in turbine airfoils, has been proposed [1]. This avoids the bulky and possible high-NOx discrete reheat combustors used in traditional approaches. The key questions regarding this approach are whether there is sufficient residence time at high temperature for fuel burnout, and whether increased emissions of NOx and CO result. This project examines the chemical kinetics basis of these questions. In the present task detailed chemical kinetics models were used to evaluate injection reheat combustion. Models used included a Siemens Westinghouse diffusion flame model, the set of CHEMKIN gas-phase kinetics equation solvers, and the GRI 3.0 detailed kinetics data base. These modules are called by a reheat-specific main program, which also provides them with data, including gas path conditions that change with distance through the turbine. Conceptually, injection could occur in either of two ways: (1) direct injection via holes in airfoil trailing edges; or (2) injection at the downstream faces of small bluff bodies placed at these edges. In the former case, combustion could occur as a diffusion flame at the hole, as a plume or streak following this zone, or as a substantially mixed out homogeneous region downstream. In the latter case, combustion could occur as a lower temperature, well-mixed, recirculating flame in the wake of the bluff body, followed by burnout in the same sequence of diffusion flame, streak, and mixed out. The results were as follows. In the case of a conventional four-stage engine, vane 1 trailing edge injection can be achieved with complete burnout

  18. Greenhouse Gas Emission from In-situ Denitrifying Bioreactors

    NASA Astrophysics Data System (ADS)

    Pluer, W.; Walter, M. T.; Geohring, L.

    2013-12-01

    Despite decades of concerted effort to mitigate nonpoint source nitrate (NO3-) pollution from agricultural lands, these efforts have not been sufficient to arrest eutrophication, which continues to be a serious and chronic problem. Two primary processes for removing excess NO3- from water are biological assimilation and denitrification. Denitrifying bacteria use NO3- as the electron acceptor for respiration in the absence of oxygen. Denitrification results in reduced forms of nitrogen, often dinitrogen gas (N2) but also nitrous oxide (N2O), an aggressive greenhouse gas (GHG). A promising solution to NO3- pollution is to intercept agricultural discharges with denitrifying bioreactors (DNBRs), though research has been limited to NO3- level reduction and omitted process mechanisms. DNBRs work by providing an anaerobic environment with plenty of organic matter (commonly woodchips) for denitrifying bacteria to flourish. While, initial results from bioreactor studies show that they can cost-effectively remove NO3-, GHG emission could be an unintended consequence. The study's goal is to determine how bioreactor design promotes microbial denitrification while limiting N2O production. It specifically focuses on expanding the body of knowledge concerning DNBRs in the areas of design implications and internal processes by measuring intermediate compounds and not solely NO3-. Nutrient samples are collected at inflow and outflow structures and tested for NO3- and nitrite (NO2-). Dissolved and headspace gas samples are collected and tested for N2O. Additional gas samples will be analyzed for naturally-occurring isotopic N2 to support proposed pathways. Designs will be analyzed both through the N2O/N2 production ratio and NO2- production caused by various residence times and inflow NO3- concentrations. High GHG ratios and NO2- production suggest non-ideal conditions or flow patterns for complete denitrification. NO3- reduction is used for comparison with previous studies. Few

  19. Molecular recognition in gas sensing: Results from acoustic wave and in-situ FTIR measurements

    SciTech Connect

    Hierlemann, A.; Ricco, A.J.; Bodenhoefer, K.; Goepel, W.

    1998-06-01

    Surface acoustic wave (SAW) measurements were combined with direct, in-situ molecular spectroscopy to understand the interactions of surface-confined sensing films with gas-phase analytes. This was accomplished by collecting Fourier-transform infrared external-reflectance spectra (FTIR-ERS) on operating SAW devices during dosing of their specifically coated surfaces with key analytes.

  20. In Situ Analysis of Organics with a Portable Mass Spectrometer

    NASA Technical Reports Server (NTRS)

    Soparawalla, Santosh

    2011-01-01

    The search for extra-terrestrial life starts at home. In order to find life on other planets, we start by examining life processes we understand on the earth. Though it may not be possible to see the life in the form of macroscopic organisms, telltale signs of life can exist in the form of small organic molecules such as peptides and amino acids. Our overall goal is to test a portable mass spectrometer (MS) system, the Mini 10.5, for astrobiological applications including in situ hydrocarbon analysis and sediments analysis using an additional automated sample processing system (ASPS). The collaborative research focuses on two current projects in the field of astrobiology. Both projects are geared towards examining organics distributed in extreme environments. One portion of study attempts to qualitatively analyze the effect of volatile organic compounds (VOC) produced by diesel exhaust on lichens growing in the desert. This requires measurements to be taken by bringing the instrument to the Mojave Desert and monitoring atmospheric composition of VOCs in situ. The second project is to evaluate the miniature MS system as a detector for the ASPS extraction system. A major obstacle of any chemometric in situ analysis is the suppression of analyte signal by concomitant signal from the surrounding environment. The ASPS extraction device has been developed at JPL to extract amino acids from sediment samples and elute them in solution. The solution is eluted at a high pH and needs to be conditioned to a more neutral pH so that dissolved amino acids can be readily protonated and subsequently analyzed by electrospray MS.

  1. A new in-situ method to determine the apparent gas diffusion coefficient of soils

    NASA Astrophysics Data System (ADS)

    Laemmel, Thomas; Paulus, Sinikka; Schack-Kirchner, Helmer; Maier, Martin

    2015-04-01

    Soil aeration is an important factor for the biological activity in the soil and soil respiration. Generally, gas exchange between soil and atmosphere is assumed to be governed by diffusion and Fick's Law is used to describe the fluxes in the soil. The "apparent soil gas diffusion coefficient" represents the proportional factor between the flux and the gas concentration gradient in the soil and reflects the ability of the soil to "transport passively" gases through the soil. One common way to determine this coefficient is to take core samples in the field and determine it in the lab. Unfortunately this method is destructive and needs laborious field work and can only reflect a small fraction of the whole soil. As a consequence insecurity about the resulting effective diffusivity on the profile scale must remain. We developed a new in-situ method using new gas sampling device, tracer gas and inverse soil gas modelling. The gas sampling device contains several sampling depths and can be easily installed into vertical holes of an auger, which allows for fast installation of the system. At the lower end of the device inert tracer gas is injected continuously. The tracer gas diffuses into the surrounding soil. The resulting distribution of the tracer gas concentrations is used to deduce the diffusivity profile of the soil. For Finite Element Modeling of the gas sampling device/soil system the program COMSOL is used. We will present the results of a field campaign comparing the new in-situ method with lab measurements on soil cores. The new sampling pole has several interesting advantages: it can be used in-situ and over a long time; so it allows following modifications of diffusion coefficients in interaction with rain but also vegetation cycle and wind.

  2. In situ and in-transit analysis of cosmological simulations

    NASA Astrophysics Data System (ADS)

    Friesen, Brian; Almgren, Ann; Lukić, Zarija; Weber, Gunther; Morozov, Dmitriy; Beckner, Vincent; Day, Marcus

    2016-08-01

    Modern cosmological simulations have reached the trillion-element scale, rendering data storage and subsequent analysis formidable tasks. To address this circumstance, we present a new MPI-parallel approach for analysis of simulation data while the simulation runs, as an alternative to the traditional workflow consisting of periodically saving large data sets to disk for subsequent `offline' analysis. We demonstrate this approach in the compressible gasdynamics/ N-body code Nyx, a hybrid MPI+OpenMP code based on the BoxLib framework, used for large-scale cosmological simulations. We have enabled on-the-fly workflows in two different ways: one is a straightforward approach consisting of all MPI processes periodically halting the main simulation and analyzing each component of data that they own (` in situ'). The other consists of partitioning processes into disjoint MPI groups, with one performing the simulation and periodically sending data to the other `sidecar' group, which post-processes it while the simulation continues (`in-transit'). The two groups execute their tasks asynchronously, stopping only to synchronize when a new set of simulation data needs to be analyzed. For both the in situ and in-transit approaches, we experiment with two different analysis suites with distinct performance behavior: one which finds dark matter halos in the simulation using merge trees to calculate the mass contained within iso-density contours, and another which calculates probability distribution functions and power spectra of various fields in the simulation. Both are common analysis tasks for cosmology, and both result in summary statistics significantly smaller than the original data set. We study the behavior of each type of analysis in each workflow in order to determine the optimal configuration for the different data analysis algorithms.

  3. In situ reaction kinetic analysis of dental restorative materials

    NASA Astrophysics Data System (ADS)

    Younas, Basma; Samad Khan, Abdul; Muzaffar, Danish; Hussain, Ijaz; Chaudhry, Aqif Anwar; Rehman, Ihtesham Ur

    2013-12-01

    The objective of this study was to evaluate in situ structural and thermal changes of dental restorative materials at periodical time intervals. The commercial materials included zinc oxide eugenol (ZOE), zinc phosphate type I (ZnPO4), glass ionomer cement type II (GIC) and resin-based nano-omposite (Filtek Z350 XT). These materials were processed according to manufacturer's instructions. For the structural analysis Fourier transform infrared spectroscopy (FTIR) was used at high resolution. TGA was used to evaluate thermal weight-loss. The FTIR spectra were collected at periodic time intervals. FTIR spectra showed that with time passing all materials exhibited an increase in peak intensities and a new appearance of shoulders and shifting of peaks for example, ZnPO4 (P-O), ZOE (C═O, C═N, C-O-C), GIC (COO-, C-H, Si-OH), composites (C═O, C═C, C═N, C-N-H). The peaks were replaced by bands and these bands became broader with time interval. Composites showed a degree of conversion and new peaks corresponded to the cross-linking of polymer composites. TGA analysis showed that significant changes in weight loss of set materials were observed after 24 h, where ZOE showed continuous changes in thermal degradation. The spectral changes and thermal degradation with time interval elucidated in situ setting behaviour and understanding of their bonding compatibility with tooth structure and change in relation to time.

  4. Mineral exploration and soil analysis using in situ neutron activation

    USGS Publications Warehouse

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

    1966-01-01

    A feasibility study has been made to operate by remote control an unshielded portable positive-ion accelerator type neutron source to induce activities in the ground or rock by "in situ" neutron irradiation. Selective activation techniques make it possible to detect some thirty or more elements by irradiating the ground for periods of a few minutes with either 3-MeV or 14-MeV neutrons. The depth of penetration of neutrons, the effect of water content of the soil on neutron moderation, gamma ray attenuation in the soil and other problems are considered. The analysis shows that, when exploring for most elements of economic interest, the reaction 2H(d,n)3He yielding ??? 3-MeV neutrons is most practical to produce a relatively uniform flux of neutrons of less than 1 keV to a depth of 19???-20???. Irradiation with high energy neutrons (??? 14 MeV) can also be used and may be better suited for certain problems. However, due to higher background and lower sensitivity for the heavy minerals, it is not a recommended neutron source for general exploration use. Preliminary experiments have been made which indicate that neutron activation in situ is feasible for a mineral exploration or qualititative soil analysis. ?? 1976.

  5. Conceptual designs for in situ analysis of Mars soil

    NASA Technical Reports Server (NTRS)

    Mckay, C. P.; Zent, A. P.; Hartman, H.

    1991-01-01

    A goal of this research is to develop conceptual designs for instrumentation to perform in situ measurements of the Martian soil in order to determine the existence and nature of any reactive chemicals. Our approach involves assessment and critical review of the Viking biology results which indicated the presence of a soil oxidant, an investigation of the possible application of standard soil science techniques to the analysis of Martian soil, and a preliminary consideration of non-standard methods that may be necessary for use in the highly oxidizing Martian soil. Based on our preliminary analysis, we have developed strawman concepts for standard soil analysis on Mars, including pH, suitable for use on a Mars rover mission. In addition, we have devised a method for the determination of the possible strong oxidants on Mars.

  6. In situ gas concentrations in the Kumano forearc basin from drilling mud gas monitoring and sonic velocity data (IODP NanTroSEIZE Exp. 319 Site C0009)

    NASA Astrophysics Data System (ADS)

    Wiersberg, T.; Doan, M.-L.; Schleicher, A. M.; Horiguchi, K.; Eguchi, N.; Erzinger, J.

    2012-04-01

    Conventional IODP shipboard methods of gas investigations comprise gas sampling from core voids and headspace gas sampling followed by shipboard gas analysis. These methods possibly underestimate the in situ gas concentration due to core degassing during retrieval and handling on deck. In few cases, a Pressure Core Sampler (PCS) was used in the past to overcome this problem, providing gas concentrations one or two order of magnitude higher than headspace gas analysis from corresponding depths. Here, we describe two new techniques applied during IODP NanTroSEIZE Exp. 319 Site C0009 riser drilling in the Kumano forearc basin to estimate in situ gas concentrations without drill core recovery. During riser drilling of site C0009 between 703 to 1594 mbsf, gas was continuously extracted from returing drilling mud and analysed in real-time (drill mud gas monitoring). This method results in information on the gas composition and gas concentration at depth. The chemical (C1-C3) and isotope (δ13C, H/D) composition of hydrocarbons, the only formation-derived gases identified in drill mud, demonstrate a microbial hydrocarbon gas source mixing with small but increasing amounts of thermogenic gas at greater depth. Methane content in drilling mud semi-quantitatively correlates with visible allochtonous material (wood, lignite) in drilling cuttings. In situ gas concentration determination from drill mud gas monitoring based on the assumption that gas is either liberated from the rock into the drilling mud during drilling and ascent with the mud column or remains in the pore space of the drilling cuttings. Drilling mud gas data were calibrated with a defined amount of C2H2 (175 l [STP]) from a carbide test and result in methane concentrations reaching up to 24 lgas/lsediment, in good agreement with findings from other IODP Legs using the PCS. Hydrocarbon gas concentrations in drilling cuttings from C0009 are significantly lower, indicating cuttings outgassing during ascent of the

  7. Analysis of in situ measurements of cirrus anvil outflow dynamics

    NASA Astrophysics Data System (ADS)

    Lederman, J. I.; Whiteway, J. A.

    2012-12-01

    The airborne campaign, EMERALD 2 (Egrett Microphysics Experiment with Radiation, Lidar, and Dynamics,) was conducted out of Darwin, Australia in 2002. Objectives included characterization of the dynamics in the cirrus anvil outflow from tropical deep convection. Two aircraft, the Egrett and King Air, were flown in tandem in the upper troposphere (7 km - 15 km) to collect in situ measurements in the anvil outflow from a storm named "Hector" that occurs on a regular basis over the Tiwi Islands north of Darwin during November and December. Turbulence probes mounted on the wings of the Egrett aircraft were used to measure the wind fluctuations across the anvil and along its length with a spatial resolution of 2 meters. The in situ measurements from the Egrett were coincident with lidar measurements of the cloud structure from the King Air aircraft flying directly below. The presentation will show results of the analysis of the measurements with an emphasis on the turbulence, gravity waves, and coherent structures that are particular to the cirrus anvil outflow environment. Emphasis is placed on the dynamics associated with the generation of mammatus formations at the base of the anvil clouds.

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

    PubMed

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

    2015-10-01

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

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

    PubMed Central

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

    2016-01-01

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

  10. Sources of biogenic methane to form marine gas hydrates: In situ production or upward migration?

    SciTech Connect

    Paull, C.K.; Ussler, W. III; Borowski, W.S.

    1993-09-01

    Potential sources of biogenic methane in the Carolina Continental Rise -- Blake Ridge sediments have been examined. Two models were used to estimate the potential for biogenic methane production: (1) construction of sedimentary organic carbon budgets, and (2) depth extrapolation of modern microbial production rates. While closed-system estimates predict some gas hydrate formation, it is unlikely that >3% of the sediment volume could be filled by hydrate from methane produced in situ. Formation of greater amounts requires migration of methane from the underlying continental rise sediment prism. Methane may be recycled from below the base of the gas hydrate stability zone by gas hydrate decomposition, upward migration of the methane gas, and recrystallization of gas hydrate within the overlying stability zone. Methane bubbles may also form in the sediment column below the depth of gas hydrate stability because the methane saturation concentration of the pore fluids decreases with increasing depth. Upward migration of methane bubbles from these deeper sediments can add methane to the hydrate stability zone. From these models it appears that recycling and upward migration of methane is essential in forming significant gas hydrate concentrations. In addition, the depth distribution profiles of methane hydrate will differ if the majority of the methane has migrated upward rather than having been produced in situ.

  11. INTEGRATION OF HIGH TEMPERATURE GAS REACTORS WITH IN SITU OIL SHALE RETORTING

    SciTech Connect

    Eric P. Robertson; Michael G. McKellar; Lee O. Nelson

    2011-05-01

    This paper evaluates the integration of a high-temperature gas-cooled reactor (HTGR) to an in situ oil shale retort operation producing 7950 m3/D (50,000 bbl/day). The large amount of heat required to pyrolyze the oil shale and produce oil would typically be provided by combustion of fossil fuels, but can also be delivered by an HTGR. Two cases were considered: a base case which includes no nuclear integration, and an HTGR-integrated case.

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

    SciTech Connect

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

    1993-01-01

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

  13. Airborne In-Situ Trace Gas Measurements of Multiple Wildfires in California (2013-2014)

    NASA Astrophysics Data System (ADS)

    Iraci, L. T.; Yates, E. L.; Tanaka, T.; Roby, M.; Gore, W.; Clements, C. B.; Lareau, N.; Ambrosia, V. G.; Quayle, B.; Schroeder, W.

    2014-12-01

    Biomass burning emissions are an important source of a wide range of trace gases and particles that can impact local, regional and global air quality, climate forcing, biogeochemical cycles and human health. In the western US, wildfires dominate over prescribed fires, contributing to atmospheric trace gas budgets and regional and local air pollution. Limited sampling of emissions from wildfires means western US emission estimates rely largely on data from prescribed fires, which may not be a suitable proxy for wildfire emissions. We report here in-situ measurements of carbon dioxide, methane, ozone and water vapor from the plumes of a variety of wildfires sampled in California in the fire seasons of 2013 and 2014. Included in the analysis are the Rim Fire (August - October 2013, near Yosemite National Park), the Morgan Fire (September 2013, near Clayton, CA), and the El Portal Fire (July - August 2014, in Yosemite National Park), among others. When possible, fires were sampled on multiple days. Emission ratios and estimated emission factors will be presented and discussed in the context of fuel composition, plume structure, and fire phase. Correlations of plume chemical composition to MODIS/VIIRS Fire Radiative Power (FRP) and other remote sensing information will be explored. Furthermore, the role of plumes in delivery of enhanced ozone concentrations to downwind municipalities will be discussed.

  14. Method for increasing the calorific value of gas produced by the in situ combustion of coal

    DOEpatents

    Shuck, Lowell Z.

    1978-01-01

    The present invention relates to the production of relatively high Btu gas by the in situ combustion of subterranean coal. The coal bed is penetrated with a horizontally-extending borehole and combustion is initiated in the coal bed contiguous to the borehole. The absolute pressure within the resulting combustion zone is then regulated at a desired value near the pore pressure within the coal bed so that selected quantities of water naturally present in the coal will flow into the combustion zone to effect a hydrogen and carbon monoxide-producing steam-carbon reaction with the hot carbon in the combustion zone for increasing the calorific value of the product gas.

  15. Aberration corrected environmental STEM (AC ESTEM) for dynamic in-situ gas reaction studies of nanoparticle catalysts

    NASA Astrophysics Data System (ADS)

    Boyes, E. D.; Gai, P. L.

    2014-06-01

    Environmental scanning transmission electron microscopy (ESTEM) with aberration correction (AC) has recently been added to the capabilities of the more established ETEM for analysis of heterogeneous nanoparticle based catalysts. It has helped to reveal the importance and potentially unique properties of individual atoms as active sites in their own right as well as pathways between established nanoparticles. A new capability is introduced for dynamic in-situ experiments under controlled conditions of specimen temperature and gas environment related to real world conditions pertinent to a range of industrial and societal priorities for new and improved chemical processes, materials, fuels, pharmaceutical products and processes, and in control or remediation of environmental emissions.

  16. Life cycle Greenhouse gas emissions of current Oil Sands Technologies: surface mining and in situ applications.

    PubMed

    Bergerson, Joule A; Kofoworola, Oyeshola; Charpentier, Alex D; Sleep, Sylvia; Maclean, Heather L

    2012-07-17

    Life cycle greenhouse gas (GHG) emissions associated with two major recovery and extraction processes currently utilized in Alberta's oil sands, surface mining and in situ, are quantified. Process modules are developed and integrated into a life cycle model-GHOST (GreenHouse gas emissions of current Oil Sands Technologies) developed in prior work. Recovery and extraction of bitumen through surface mining and in situ processes result in 3-9 and 9-16 g CO(2)eq/MJ bitumen, respectively; upgrading emissions are an additional 6-17 g CO(2)eq/MJ synthetic crude oil (SCO) (all results are on a HHV basis). Although a high degree of variability exists in well-to-wheel emissions due to differences in technologies employed, operating conditions, and product characteristics, the surface mining dilbit and the in situ SCO pathways have the lowest and highest emissions, 88 and 120 g CO(2)eq/MJ reformulated gasoline. Through the use of improved data obtained from operating oil sands projects, we present ranges of emissions that overlap with emissions in literature for conventional crude oil. An increased focus is recommended in policy discussions on understanding interproject variability of emissions of both oil sands and conventional crudes, as this has not been adequately represented in previous studies.

  17. In situ and operando spectroscopy for assessing mechanisms of gas sensing.

    PubMed

    Gurlo, Alexander; Riedel, Ralf

    2007-01-01

    The mechanistic description of gas sensing on inorganic, organic, and polymeric materials is of great scientific and technological interest. The understanding of surface and bulk reactions responsible for gas-sensing effects will lead to increased selectivity and sensitivity in the chemical determination of gases and thus to the development of better sensors. In recent years, spectroscopic tools have been developed to follow the physicochemical processes taking place in an active sensing element in real time and under operating conditions. Thus, the monitoring of the processes in "living" gas sensors is no longer an unsolvable problem. This Review gives an overview of in situ and operando spectroscopic techniques for the study of gas-sensing mechanisms on solid-state sensors.

  18. Tunable photonic cavities for in-situ spectroscopic trace gas detection

    DOEpatents

    Bond, Tiziana; Cole, Garrett; Goddard, Lynford

    2012-11-13

    Compact tunable optical cavities are provided for in-situ NIR spectroscopy. MEMS-tunable VCSEL platforms represents a solid foundation for a new class of compact, sensitive and fiber compatible sensors for fieldable, real-time, multiplexed gas detection systems. Detection limits for gases with NIR cross-sections such as O.sub.2, CH.sub.4, CO.sub.x and NO.sub.x have been predicted to approximately span from 10.sup.ths to 10s of parts per million. Exemplary oxygen detection design and a process for 760 nm continuously tunable VCSELS is provided. This technology enables in-situ self-calibrating platforms with adaptive monitoring by exploiting Photonic FPGAs.

  19. Extractive electrospray ionization mass spectrometry toward in situ analysis without sample pretreatment.

    PubMed

    Li, Ming; Hu, Bin; Li, Jianqiang; Chen, Rong; Zhang, Xie; Chen, Huanwen

    2009-09-15

    A homemade novel nanoextractive electrospray ionization (nanoEESI) source has been characterized for in situ mass spectrometric analysis of ambient samples without sample pretreatment. The primary ions generated using a nanospray emitter interact with the neutral sample plume created by manually nebulizing liquid samples, allowing production of the analyte ions in the spatial cross section of the nanoEESI source. The performance of nanoEESI is experimentally investigated by coupling the nanoEESI source to a commercial LTQ mass spectrometer for rapid analysis of various ambient samples using positive/negative ion detection modes. Compounds of interest in actual samples such as aerosol drug preparations, beverages, milk suspensions, farmland water, and groundwater were unambiguously detected using tandem nanoEESI ion trap mass spectrometry. The limit of detection was low picogram per milliliter levels for the compounds tested. Acceptable relative standard deviation (RSD) values (5-10%) were obtained for direct measurement of analytes in complex matrixes, providing linear dynamic signal responses using manual sample introduction. A single sample analysis was completed within 1.2 s. Requiring no sheath gas for either primary ion production or neutral sample introduction, the nanoEESI has advantages including readiness for miniaturization and integration, simple maintenance, easy operation, and low cost. The experimental data demonstrate that the nanoEESI is a promising tool for high-throughput, sensitive, quantitative, in situ analysis of ambient complex samples, showing potential applications for in situ analysis in multiple disciplines including but not limited to pharmaceutical analysis, food quality control, pesticides residue detection, and homeland security.

  20. Development of an in situ derivatization technique for rapid analysis of levoglucosan and polar compounds in atmospheric organic aerosol

    NASA Astrophysics Data System (ADS)

    Sheesley, Rebecca J.; Mieritz, Mark; DeMinter, Jeff T.; Shelton, Brandon R.; Schauer, James J.

    2015-12-01

    A novel thermal desorption gas chromatography mass spectrometry (TD-GCMS) technique was developed for the analysis of levoglucosan and other polar compounds in atmospheric organic aerosol. The method employs an in situ derivatization to add tri-methylsilyl groups to alcohol functional groups on simple carbohydrates, like levoglucosan and sterols. The new method was then demonstrated on a set of 40 filter samples collected in Fresno, CA. The results from the in situ silylation TD-GCMS method were compared, using levoglucosan, with a solvent extraction, high-volume injection GCMS method resulting in an r2 = 0.91.

  1. Development of an In-Situ Data Logging System for Multiple Trace Gas Analyzers

    SciTech Connect

    Mioduszewski, John R.; Yu, Xiao-Ying

    2008-09-01

    A field deployable in-situ data logging system was developed at Pacific Northwest National Laboratory for trace gases including carbon monoxide (CO), ozone (O3), sulfur dioxide (SO2), and nitrogen oxides including nitric oxide, nitrogen dioxide, and odd nitrogens (NO/NO2/NOx). On-line data acquisition and calibration are essential to analysis of observables and data integrity. As such, a program was written to control the communication between the data logger and each analyzer in Logger Net, a program used to communicate with the data logger. Analog outputs were collected by a CR-23X Campbell data logger between July 2, 2007 and August 7, 2007 in Richland, Washington, with data being averaged every minute. A dynamic calibrator was used to calibrate the instruments using a gas standard with NIST-certified concentration. The National Oceanic and Atmospheric Administration’s HYSPLIT model was used to create a backward and forward trajectory of air during an episode of peak O3 to determine pollutant sources and sinks. Data collected through the duration of the sampling period revealed several observations. Concentrations of all trace gases were low, due in part to the scarcity of pollutant sources in the region. The average SO2 reading was less than 0.05 ppb over the period, whereas mixing ratios of 1-20 ppb are more common in rural-suburban environments. NO, NO2, and NOx averaged 0.3, 12.2, and 12.8 ppb, respectively, while the average CO was 228.5 ppb. Typical O3 in similar environments peaks at 80-150 ppb, but the highest mixing ratio of O3 observed was less than 45 ppb. HYSPLIT offered no apparent source for additional pollutants during the high O3 episode, but increased photochemistry due to high temperatures would explain the increase in O3. Both SO2 and NO readings registered near the detection limit of the instruments, and displayed a trend similar to background noise. The development of the data logging and display system for key trace gas species is an

  2. Gas-phase advanced oxidation for effective, efficient in situ control of pollution.

    PubMed

    Johnson, Matthew S; Nilsson, Elna J K; Svensson, Erik A; Langer, Sarka

    2014-01-01

    In this article, gas-phase advanced oxidation, a new method for pollution control building on the photo-oxidation and particle formation chemistry occurring in the atmosphere, is introduced and characterized. The process uses ozone and UV-C light to produce in situ radicals to oxidize pollution, generating particles that are removed by a filter; ozone is removed using a MnO2 honeycomb catalyst. This combination of in situ processes removes a wide range of pollutants with a comparatively low specific energy input. Two proof-of-concept devices were built to test and optimize the process. The laboratory prototype was built of standard ventilation duct and could treat up to 850 m(3)/h. A portable continuous-flow prototype built in an aluminum flight case was able to treat 46 m(3)/h. Removal efficiencies of >95% were observed for propane, cyclohexane, benzene, isoprene, aerosol particle mass, and ozone for concentrations in the range of 0.4-6 ppm and exposure times up to 0.5 min. The laboratory prototype generated a OH(•) concentration derived from propane reaction of (2.5 ± 0.3) × 10(10) cm(-3) at a specific energy input of 3 kJ/m(3), and the portable device generated (4.6 ± 0.4) × 10(9) cm(-3) at 10 kJ/m(3). Based on these results, in situ gas-phase advanced oxidation is a viable control strategy for most volatile organic compounds, specifically those with a OH(•) reaction rate higher than ca. 5 × 10(-13) cm(3)/s. Gas-phase advanced oxidation is able to remove compounds that react with OH and to control ozone and total particulate mass. Secondary pollution including formaldehyde and ultrafine particles might be generated, depending on the composition of the primary pollution.

  3. Chemical composition and the nutritive value of pistachio epicarp (in situ degradation and in vitro gas production techniques)

    PubMed Central

    Bakhshizadeh, Somayeh; Taghizadeh, Akbar; Janmohammadi, Hossein; Alijani, Sadegh

    2014-01-01

    The nutritive value of pistachio epicarp (PE) was evaluated by in situ and in vitro techniques. Chemical analysis indicated that PE was high in crude protein (11.30%) and low in neutral detergent fiber (26.20%). Total phenols, total tannins, condensed tannins and hydrolysable tannins contents in PE were 8.29%, 4.48%, 0.49% and 3.79%, respectively. Ruminal dry matter and crude protein degradation after 48 hr incubation were 75.21% and 82.52%, respectively. The gas production volume at 48 hr for PE was 122.47 mL g-1DM. As a whole, adding polyethylene glycol (PEG) to PE increased (p < 0.05) gas production volumes, organic matter digestibility and the metabolizable energy that illustrated inhibitory effect of phenolics on rumen microbial fermentation and the positive influence of PEG on digestion PE. The results showed that PE possessed potentials to being used as feed supplements. PMID:25568691

  4. In situ Gas Measurements in Five Experimental Waste Rock Piles, Antamina Mine, Peru

    NASA Astrophysics Data System (ADS)

    Singurindy, O.; Blackmore, S. R.; Wild, A.; Mayer, K. U.; Beckie, R. D.; Smith, L.

    2009-12-01

    At the Antamina mine (Peru), a skarn deposit consisting of a quartz-monzonite porphyry hosted in limestone is mined for copper, zinc, lead, and molybdenum. Five (5) experimental waste rock piles were constructed at Antamina and instrumented to evaluate processes controlling metal release under neutral-pH drainage conditions. The piles were built over a 3-year period and each contains approximately 25,000 tonnes of waste rock classified as ‘slightly reactive’ (Pile 1 -2007), ‘reactive’ (Pile 2 and 3 - 2008), or a combination of rock of variable reactivity (Pile 4 and 5 - 2009). All waste rock, reactive to non-reactive, contains variable amounts of sulphide and carbonate minerals. Oxidation of sulphide minerals consumes O2 and generates low-pH conditions, which promotes carbonate dissolution and elevates CO2 concentrations. Sampling of the piles’ 64 in situ gas lines, using a portable gas analyzing system, revealed numerous CO2-enriched and O2-depleted zones. Piles constructed of the most reactive and fine-grained rock (Pile 2 and 3) show the highest CO¬2 concentrations (≥ 20,000 ppm), with Piles 1, 4 and 5 showing lower maximum concentrations of 1,600 ppm, 1,100 ppm, 2,900 ppm, respectively. The highest CO2 concentrations are located in the interior and near the bottom of the piles. Of the gas lines sampled from Pile 2 and 3, 88% and 95%, respectively are CO2-enriched (defined as > 2 x ambient values). The younger and less reactive piles (Pile 4 and 5) show CO2-enriched values in 3% and 17% of gas lines measured. The exothermic reaction of sulphide oxidation is also monitored by 12 in situ thermistors. Pile 2 and 3 temperatures are the highest at 9 - 10 oC. These temperatures are significantly warmer than ambient conditions (i.e., ~ 6 oC, June average) and correlate well with pockets of high CO2 concentrations. The gradational decline of CO2 concentrations with depth supports the notion that gas transport is dominated by vertical movement, while

  5. Rapid human chromosome aberration analysis using fluorescence in situ hybridization.

    PubMed

    Lucas, J N; Tenjin, T; Straume, T; Pinkel, D; Moore, D; Litt, M; Gray, J W

    1989-07-01

    We have used in situ hybridization of repeat-sequence DNA probes, specific to the paracentromric locus 1q12 and the telomeric locus 1p36, to fluorescently stain regions that flank human chromosome 1p. This procedure was used for fast detection of structural aberrations involving human chromosome 1p in two separate experiments. In one, human lymphocytes were irradiated with 0, 0.8, 1.6, 2.4 and 3.2 Gy of 137Cs gamma-rays. In the other, human lymphocytes were irradiated with 0, 0.09, 0.18, 2.0, 3.1 and 4.1 Gy of 60Co gamma-rays. The frequencies (per cell) of translocations and dicentrics with one breakpoint in 1p and one elsewhere in the genome were determined for cells irradiated at each dose point. These frequencies both increased with dose, D, in a linear-quadratic manner. The delta, alpha, and beta coefficients resulting from a fit of the equation f(D)=delta + alphaD + betaD2 to the translocation frequency dose-response data were 0.0025, 0.0027 and 0.0037 for 137Cs gamma-rays, and 0.0010, 0.0041, and 0.0057 for 60Co gamma-rays. The delta, alpha, and beta coefficients resulting from a fit to the dicentric frequency dose-response data were 0.0005, 0.0010 and 0.0028 for 137Cs gamma-rays and 0.0001, 0.0002 and 0.0035, for 60Co gamma-rays. Approximately 32,000 metaphase spreads were scored in this study. The average analysis rate was over two metaphase spreads per minute. However, an experienced analyst was able to find and score one metaphase spread every 10s. The importance of this new cytogenetic analysis technique for biological dosimetry and in vivo risk assessment is discussed.

  6. In-situ gas hydrate hydrate saturation estimated from various well logs at the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope

    USGS Publications Warehouse

    Lee, M.W.; Collett, T.S.

    2011-01-01

    In 2006, the U.S. Geological Survey (USGS) completed detailed analysis and interpretation of available 2-D and 3-D seismic data and proposed a viable method for identifying sub-permafrost gas hydrate prospects within the gas hydrate stability zone in the Milne Point area of northern Alaska. To validate the predictions of the USGS and to acquire critical reservoir data needed to develop a long-term production testing program, a well was drilled at the Mount Elbert prospect in February, 2007. Numerous well log data and cores were acquired to estimate in-situ gas hydrate saturations and reservoir properties.Gas hydrate saturations were estimated from various well logs such as nuclear magnetic resonance (NMR), P- and S-wave velocity, and electrical resistivity logs along with pore-water salinity. Gas hydrate saturations from the NMR log agree well with those estimated from P- and S-wave velocity data. Because of the low salinity of the connate water and the low formation temperature, the resistivity of connate water is comparable to that of shale. Therefore, the effect of clay should be accounted for to accurately estimate gas hydrate saturations from the resistivity data. Two highly gas hydrate-saturated intervals are identified - an upper ???43 ft zone with an average gas hydrate saturation of 54% and a lower ???53 ft zone with an average gas hydrate saturation of 50%; both zones reach a maximum of about 75% saturation. ?? 2009.

  7. A piezoelectric electrospun platform for in situ cardiomyocyte contraction analysis

    NASA Astrophysics Data System (ADS)

    Beringer, Laura Toth

    hyperpolarized state, proving their potential use as contractile analysis microdevices. The third and final aim of this dissertation was to be able to measure contraction events from both cultured cardiomyocytes and whole tissues in situ. Rat neonatal cardiomyocytes grew on the prepared collagen/PVDF-TrFe nanogenerators and yielded a distinct signal after 8 days of growth. These contractions were verified with live cell imaging and video recording. In addition, cardiomyocyte exposure to the drug isoproterenol increased contraction strength and frequency, which was reflected in the nanogenerator recordings. Frog whole heart and heart tissue slices also were interfaced with the fabricated nanogenerators and signals were recorded. The same held true for heart slices from male Sprague-Dawley rats. These signals were determined to be statistically different compared to the control baseline nanogenerator recordings in media in the absence of cell culture. Overall the fabricated nanogenerators have demonstrated their potential to be used as in situ analysis tools for contractile events and have potential in the field of personalized medicine and drug diagnostic assays. The facile fabrication and ease of setup to obtain the electrical voltage signal corresponding to the contractile events are what sets the nanogenerator apart from any polymer based sensor available today.

  8. Versatile in situ powder X-ray diffraction cells for solid–gas investigations

    PubMed Central

    Jensen, Torben R.; Nielsen, Thomas K.; Filinchuk, Yaroslav; Jørgensen, Jens-Erik; Cerenius, Yngve; Gray, Evan MacA.; Webb, Colin J.

    2010-01-01

    This paper describes new sample cells and techniques for in situ powder X-ray diffraction specifically designed for gas absorption studies up to ca 300 bar (1 bar = 100 000 Pa) gas pressure. The cells are for multipurpose use, in particular the study of solid–gas reactions in dosing or flow mode, but can also handle samples involved in solid–liquid–gas studies. The sample can be loaded into a single-crystal sapphire (Al2O3) capillary, or a quartz (SiO2) capillary closed at one end. The advantages of a sapphire single-crystal cell with regard to rapid pressure cycling are discussed, and burst pressures are calculated and measured to be ∼300 bar. An alternative and simpler cell based on a thin-walled silicate or quartz glass capillary, connected to a gas source via a VCR fitting, enables studies up to ∼100 bar. Advantages of the two cell types are compared and their applications are illustrated by case studies. PMID:22477780

  9. Terra Vac In Situ Vacuum Extraction System: Applications Analysis Report

    EPA Science Inventory

    This document is an evaluation of the Terra Vac in situ vacuum extraction system and its applicability as a treatment method for waste site cleanup. This report analyzes the results from the Superfund Innovative Technology Evaluation (SITE) Program’s 56-day demonstration at t...

  10. 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 ...

  11. High-temperature in situ crystallographic observation of reversible gas sorption in impermeable organic cages

    PubMed Central

    Baek, Seung Bin; Moon, Dohyun; Graf, Robert; Cho, Woo Jong; Park, Sung Woo; Yoon, Tae-Ung; Cho, Seung Joo; Hwang, In-Chul; Bae, Youn-Sang; Spiess, Hans W.; Lee, Hee Cheon; Kim, Kwang S.

    2015-01-01

    Crystallographic observation of adsorbed gas molecules is a highly difficult task due to their rapid motion. Here, we report the in situ single-crystal and synchrotron powder X-ray observations of reversible CO2 sorption processes in an apparently nonporous organic crystal under varying pressures at high temperatures. The host material is formed by hydrogen bond network between 1,3,5-tris-(4-carboxyphenyl)benzene (H3BTB) and N,N-dimethylformamide (DMF) and by π–π stacking between the H3BTB moieties. The material can be viewed as a well-ordered array of cages, which are tight packed with each other so that the cages are inaccessible from outside. Thus, the host is practically nonporous. Despite the absence of permanent pathways connecting the empty cages, they are permeable to CO2 at high temperatures due to thermally activated molecular gating, and the weakly confined CO2 molecules in the cages allow direct detection by in situ single-crystal X-ray diffraction at 323 K. Variable-temperature in situ synchrotron powder X-ray diffraction studies also show that the CO2 sorption is reversible and driven by temperature increase. Solid-state magic angle spinning NMR defines the interactions of CO2 with the organic framework and dynamic motion of CO2 in cages. The reversible sorption is attributed to the dynamic motion of the DMF molecules combined with the axial motions/angular fluctuations of CO2 (a series of transient opening/closing of compartments enabling CO2 molecule passage), as revealed from NMR and simulations. This temperature-driven transient molecular gating can store gaseous molecules in ordered arrays toward unique collective properties and release them for ready use. PMID:26578758

  12. Measuring in situ methane concentrations over time at Gas Hydrate seafloor observatories

    NASA Astrophysics Data System (ADS)

    Lapham, L.; Wilson, R. M.; Chanton, J.; Higley, P.; Lutken, C.; Riedel, M.

    2011-12-01

    Since 2006, we have been working on outfitting Gas Hydrate seafloor observatories with instruments, called Pore-Fluid Arrays, to collect and measure in situ methane concentrations and other biogeochemical parameters over time. The central technology within the PFA's uses OsmoSampler instruments that use osmosis to pull fluids slowly through ports into 300 meter-long copper tubing coil. OsmoSamplers are robust, require no power, and give sample resolution on the order of days to weeks. They allow questions about the dynamics of a system, in our case, gas hydrate systems, to be asked. For example, at the Gulf of Mexico Gas Hydrate Research Consortium monitoring station, we asked "on what time scale do gas hydrates form or decompose?" A 4-month time-series from Mississippi Canyon 118 gave unexpected results showing methane dynamics from the deep-sea influenced by regional tectonic activity. In 2009, we extended this tectonic link to methane release by asking the specific question "is shallow gas released from the seafloor when regional tectonics is active, and, if so, what is the temporal variability of such release events?" To answer this, we deployed a PFA in an area of seafloor where extensive methane venting is known to occur, Northern Cascadia margin gas hydrate sites. This area has seafloor cracks with active bubble streams and thin bacterial mats suggesting shallow gas and possible pore-fluid saturation. One of these gas crack sites, informally named "bubbly gulch", was chosen to deploy a PFA for 9 months. The PFA was modified to be ROV-deployable and was made up of 4 OsmoSamplers that were each plumbed to a port along a 1-meter probe tip using small diameter tubing. Because of the high methane concentrations anticipated, in situ pressures were maintained within the coil by the addition of a high pressure valve. Water samples were collected from the overlying water, at the sediment-water interface, and 6 and 10 cm into the sediments. Bottom water temperatures

  13. Assessment of a multi-species in-situ FTIR for precise atmospheric greenhouse gas observations

    NASA Astrophysics Data System (ADS)

    Hammer, S.; Griffith, D. W. T.; Konrad, G.; Vardag, S.; Caldow, C.; Levin, I.

    2012-05-01

    We thoroughly evaluate the performance of a multi-species, in-situ FTIR analyser with respect to high accuracy needs for greenhouse gas monitoring networks. The in-situ FTIR analyser measures CO2, CO, CH4 and N2O mole fractions continuously, all with better reproducibility than requested by the WMO-GAW inter-laboratory compatibility (ILC) goal. Simultaneously determined δ13CO2 reaches reproducibility as good as 0.03‰. This paper focuses on the quantification of residual dependencies between the measured components and the thermodynamic properties of the sample as well as the cross-sensitivities among the sample constituents. The instrument has proven to be linear for all components in the ambient range. The temporal stability of the instrument was investigated by 10 months of continuously collected quality control measures. Based on these measures we conclude that for moderately stable laboratory conditions weekly calibrations of the instrument are sufficient to reach WMO-GAW ILC goals.

  14. In situ and laboratory toxicity of coalbed natural gas produced waters with elevated sodium bicarbonate

    USGS Publications Warehouse

    Farag, Aida M.; Harper, David D.; Skaar, Don

    2014-01-01

    Some tributaries in the Powder River Structural Basin, USA, were historically ephemeral, but now contain water year round as a result of discharge of coalbed natural gas (CBNG)-produced waters. This presented the opportunity to study field sites with 100% effluent water with elevated concentrations of sodium bicarbonate. In situ experiments, static renewal experiments performed simultaneously with in situ experiments, and static renewal experiments performed with site water in the laboratory demonstrated that CBNG-produced water reduces survival of fathead minnow (Pimephales promelas) and pallid sturgeon (Scaphirhynchus albus). Age affected survival of fathead minnow, where fish 2 d posthatch (dph) were more sensitive than 6 dph fish, but pallid sturgeon survival was adversely affected at both 4 and 6 dph. This may have implications for acute assays that allow for the use of fish up to 14 dph. The survival of early lifestage fish is reduced significantly in the field when concentrations of NaHCO3 rise to more than 1500 mg/L (also expressed as >1245 mg HCO3 (-) /L). Treatment with the Higgin's Loop technology and dilution of untreated water increased survival in the laboratory. The mixing zones of the 3 outfalls studied ranged from approximately 800 m to 1200 m below the confluence. These experiments addressed the acute toxicity of effluent waters but did not address issues related to the volumes of water that may be added to the watershed.

  15. In situ and laboratory toxicity of coalbed natural gas produced waters with elevated sodium bicarbonate.

    PubMed

    Farag, Aïda M; Harper, David D; Skaar, Don

    2014-09-01

    Some tributaries in the Powder River Structural Basin, USA, were historically ephemeral, but now contain water year round as a result of discharge of coalbed natural gas (CBNG)-produced waters. This presented the opportunity to study field sites with 100% effluent water with elevated concentrations of sodium bicarbonate. In situ experiments, static renewal experiments performed simultaneously with in situ experiments, and static renewal experiments performed with site water in the laboratory demonstrated that CBNG-produced water reduces survival of fathead minnow (Pimephales promelas) and pallid sturgeon (Scaphirhynchus albus). Age affected survival of fathead minnow, where fish 2 d posthatch (dph) were more sensitive than 6 dph fish, but pallid sturgeon survival was adversely affected at both 4 and 6 dph. This may have implications for acute assays that allow for the use of fish up to 14 dph. The survival of early lifestage fish is reduced significantly in the field when concentrations of NaHCO(3) rise to more than 1500 mg/L (also expressed as >1245 mg HCO(3) (-) /L). Treatment with the Higgin's Loop technology and dilution of untreated water increased survival in the laboratory. The mixing zones of the 3 outfalls studied ranged from approximately 800 m to 1200 m below the confluence. These experiments addressed the acute toxicity of effluent waters but did not address issues related to the volumes of water that may be added to the watershed.

  16. A broadband absorption spectrometer using light emitting diodes for ultrasensitive, in situ trace gas detection

    SciTech Connect

    Langridge, Justin M.; Shillings, Alexander J. L.; Jones, Roderic L.; Ball, Stephen M.

    2008-12-15

    A broadband absorption spectrometer has been developed for highly sensitive and target-selective in situ trace gas measurements. The instrument employs two distinct modes of operation: (i) broadband cavity enhanced absorption spectroscopy (BBCEAS) is used to quantify the concentration of gases in sample mixtures from their characteristic absorption features, and (ii) periodic measurements of the cavity mirrors' reflectivity are made using step-scan phase shift cavity ringdown spectroscopy (PSCRDS). The latter PSCRDS method provides a stand-alone alternative to the more usual method of determining mirror reflectivities by measuring BBCEAS absorption spectra for calibration samples of known composition. Moreover, the instrument's two modes of operation use light from the same light emitting diode transmitted through the cavity in the same optical alignment, hence minimizing the potential for systematic errors between mirror reflectivity determinations and concentration measurements. The ability of the instrument to quantify absorber concentrations is tested in instrument intercomparison exercises for NO{sub 2} (versus a laser broadband cavity ringdown spectrometer) and for H{sub 2}O (versus a commercial hygrometer). A method is also proposed for calculating effective absorption cross sections for fitting the differential structure in BBCEAS spectra due to strong, narrow absorption lines that are under-resolved and hence exhibit non-Beer-Lambert law behavior at the resolution of the BBCEAS measurements. This approach is tested on BBCEAS spectra of water vapor's 4v+{delta} absorption bands around 650 nm. The most immediate analytical application of the present instrument is in quantifying the concentration of reactive trace gases in the ambient atmosphere. The instrument's detection limits for NO{sub 3} as a function of integration time are considered in detail using an Allan variance analysis. Experiments under laboratory conditions produce a 1{sigma} detection limit

  17. A broadband absorption spectrometer using light emitting diodes for ultrasensitive, in situ trace gas detection

    NASA Astrophysics Data System (ADS)

    Langridge, Justin M.; Ball, Stephen M.; Shillings, Alexander J. L.; Jones, Roderic L.

    2008-12-01

    A broadband absorption spectrometer has been developed for highly sensitive and target-selective in situ trace gas measurements. The instrument employs two distinct modes of operation: (i) broadband cavity enhanced absorption spectroscopy (BBCEAS) is used to quantify the concentration of gases in sample mixtures from their characteristic absorption features, and (ii) periodic measurements of the cavity mirrors' reflectivity are made using step-scan phase shift cavity ringdown spectroscopy (PSCRDS). The latter PSCRDS method provides a stand-alone alternative to the more usual method of determining mirror reflectivities by measuring BBCEAS absorption spectra for calibration samples of known composition. Moreover, the instrument's two modes of operation use light from the same light emitting diode transmitted through the cavity in the same optical alignment, hence minimizing the potential for systematic errors between mirror reflectivity determinations and concentration measurements. The ability of the instrument to quantify absorber concentrations is tested in instrument intercomparison exercises for NO2 (versus a laser broadband cavity ringdown spectrometer) and for H2O (versus a commercial hygrometer). A method is also proposed for calculating effective absorption cross sections for fitting the differential structure in BBCEAS spectra due to strong, narrow absorption lines that are under-resolved and hence exhibit non-Beer-Lambert law behavior at the resolution of the BBCEAS measurements. This approach is tested on BBCEAS spectra of water vapor's 4v+δ absorption bands around 650 nm. The most immediate analytical application of the present instrument is in quantifying the concentration of reactive trace gases in the ambient atmosphere. The instrument's detection limits for NO3 as a function of integration time are considered in detail using an Allan variance analysis. Experiments under laboratory conditions produce a 1σ detection limit of 0.25 pptv for a 10 s

  18. In Situ Analysis of Organics and Isotopes at Mars

    NASA Astrophysics Data System (ADS)

    Mahaffy, P. R.; Atreya, S. K.; Brinckerhoff, W. B.; Cabane, M.; Coll, P.; Demick, J.; Harpold, D. N.; Ming, D.; Niemann, H.; Owen, T.; Raulin, F.; Scott, J.; Webster, C.

    2003-05-01

    The recent success of the "follow the water" imperative for Mars exploration is tempered by the fact that more than 2 decades after Viking, much remains unknown about the state of carbon at the planet's surface. Therefore, a key objective for lander missions that follow MER will be a search for the location and nature of organic molecules and other carbon containing species. Reduced or partially oxidized compounds may reveal the nature of ancient or even present biotic or prebiotic processes. Ongoing definition and development of advanced techniques and protocols to "follow the carbon" will be described. For example, an instrument suite presently under development to be proposed for inclusion on the 2009 Mars Science Laboratory consists of an advanced gas chromatograph mass spectrometer (GCMS) with derivatization capability coupled with a laser desorption time-of-flight mass spectrometer (LDMS) and a tunable laser spectrometer (TLS). The suite is designated SAM (for Sample Analysis at Mars) and is designed to carry out analysis of both atmospheric gases and volatiles released from solid phase soils, rock samples, and ices. Volatile organic molecules and their pyrolysis products are analyzed by the GCMS and TLS, and refractory organics and elements by the LDMS. Additional objectives include higher precision measurements than have been obtained, to date, of the abundances and isotope ratios of the noble gases and a range of light elements including H, C, O, and N in both the atmosphere and soil. SAM can also contribute to geochemical objectives with the identification of various minerals through evolved gas analysis (EGA) of stable thermal decomposition products such as H2O, CO2, and oxides of nitrogen and sulfur using the MS and TLS as the detector. Recent EGA studies on Mars analogue materials that illustrate this capability are described. This work is supported by funding from NASA and CNES

  19. Laboratory Studies Of Titan Haze: Simultaneous In Situ Detection Of Gas And Particle Species

    NASA Astrophysics Data System (ADS)

    Horst, Sarah; Li, R.; Yoon, H.; Hicks, R.; de Gouw, J.; Tolbert, M.

    2012-10-01

    Analyses of data obtained by multiple instruments carried by Cassini and Huygens have increased our knowledge of the composition of Titan’s atmosphere. While a wealth of new information about the aerosols in Titan’s atmosphere was obtained, their composition is still not well constrained. Laboratory experiments will therefore play a key role in furthering our understanding of the chemical processes resulting in the formation of haze in Titan’s atmosphere and its possible composition. We have obtained simultaneous in situ measurements of the gas- and particle-phase compositions produced by our Titan atmosphere simulation experiments (see e.g. [1]). The gas phase composition was measured using a Proton-Transfer Ion-Trap Mass Spectrometer (PIT-MS) and the aerosol composition was measured using a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS). This complementary set of measurements will allow us to address the partitioning of gas- and aerosol-phase species. Knowledge of the gas phase composition in which the particles in our experiments form allows both for better comparison to the chemistry that is occurring in Titan’s atmosphere and for enabling more accurate determination of the possible pathways involved in the transition from gas phase to aerosol. We will compare the results from experiments that used two different initial gas mixtures (98% N2/2% CH4 and 98%N2/2%CH4/50 ppm CO) and two different energy sources to initiate the chemical reactions that result in particle formation (spark discharge using a Tesla coil or FUV irradiation from a deuterium lamp (115-400 nm)). [1] Trainer, M.G., et al. (2012) Astrobiology, 12, 315-326. SMH is supported by NSF Astronomy and Astrophysics Postdoctoral Fellowship AST-1102827.

  20. Intact Capture and In-situ Analysis System for Possible Biomarkers of Enceladus Plume Particles

    NASA Astrophysics Data System (ADS)

    Yano, Hajime; Fujishima, Kosuke; Rothschild, Lynn; Carbonnier, Benjamin; Guerrouache, Mohamed; Dziomba, Szymon; Tabata, Makoto

    2016-07-01

    A combination of intact capture and in-situ detection of organic molecules from extraterrestrial environments is a key step towards understanding the variety and distribution of the building blocks of life other than the terrestrial one. The best candidate in terms of technical feasibility of our time is to sample currently ejecting icy plumes of the Satrun's satellite Enceladus. While gas chromatography/mass spectrometry (GC/MS) has been dominantly used as successful and robust organic detection system in space, it is not suited for the separation and detection of non-volatile, heat-degradable organic molecules. Using polypeptides as a candidate molecule target, we we able to separate 16 out of the 17 tripeptides consisting of abiotically available amino acids by using capillary electrophoresis (CE). This can be regarded an example of possible bio-signatures that can be found in habitable extraterrestrial environments such as deep habitats of internal oceans of satellites of gas giants like Enceladus. We further used these peptides for the simulated Enceladus sample return using hypervelocity impact experiment facility at the same encountering velocity (i.e., 4-6 km/s) as flying through sampling mission to its plumes like the LIFE mission concept. As a result by using the space-proven 0.01g/cc aerogels, two peptide peaks corresponding to negatively charged peptides were detected, thus representing a full simulation of the capture, extraction and analysis of peptides from plume particles. Since the aerogel module is crushable and can be soaked with the electrophoresis agents/solutions and injected to capillary, this media can be used for in-situ wet analysis, in addition to previously known usage for sample return missions.

  1. Method of monitoring photoactive organic molecules in-situ during gas-phase deposition of the photoactive organic molecules

    DOEpatents

    Forrest, Stephen R.; Vartanian, Garen; Rolin, Cedric

    2015-06-23

    A method for in-situ monitoring of gas-phase photoactive organic molecules in real time while depositing a film of the photoactive organic molecules on a substrate in a processing chamber for depositing the film includes irradiating the gas-phase photoactive organic molecules in the processing chamber with a radiation from a radiation source in-situ while depositing the film of the one or more organic materials and measuring the intensity of the resulting photoluminescence emission from the organic material. One or more processing parameters associated with the deposition process can be determined from the photoluminescence intensity data in real time providing useful feedback on the deposition process.

  2. BOREAS TE-9 In Situ Diurnal Gas Exchange of NAS Boreal Forest Stands

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Curd, Shelaine (Editor); Margolis, Hank; Coyea, Marie; Dang, Qinglai

    2000-01-01

    The BOREAS TE-9 team collected several data sets related to chemical and photosynthetic properties of leaves in boreal forest tree species. The purpose of the BOREAS TE-09 study was threefold: 1) to provide in situ gas exchange data that will be used to validate models of photosynthetic responses to light, temperature, and carbon dioxide (CO2); 2) to compare the photosynthetic responses of different tree crown levels (upper and lower); and 3) to characterize the diurnal water potential curves for these sites to get an indication of the extent to which soil moisture supply to leaves might be limiting photosynthesis. The gas exchange data of the BOREAS NSA were collected to characterize diurnal gas exchange and water potential of two canopy levels of five boreal canopy cover types: young jack pine, old jack pine, old aspen, lowland old black spruce, and upland black spruce. These data were collected between 27-May-1994 and 17-Sep-1994. The data are provided in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  3. In-situ Micro-structural Studies of Gas Hydrate Formation in Sedimentary Matrices

    NASA Astrophysics Data System (ADS)

    Kuhs, Werner F.; Chaouachi, Marwen; Falenty, Andrzej; Sell, Kathleen; Schwarz, Jens-Oliver; Wolf, Martin; Enzmann, Frieder; Kersten, Michael; Haberthür, David

    2015-04-01

    The formation process of gas hydrates in sedimentary matrices is of crucial importance for the physical and transport properties of the resulting aggregates. This process has never been observed in-situ with sub-micron resolution. Here, we report on synchrotron-based micro-tomographic studies by which the nucleation and growth processes of gas hydrate were observed in different sedimentary matrices (natural quartz, glass beds with different surface properties, with and without admixtures of kaolinite and montmorillonite) at varying water saturation. The nucleation sites can be easily identified and the growth pattern is clearly established. In under-saturated sediments the nucleation starts at the water-gas interface and proceeds from there to form predominantly isometric single crystals of 10-20μm size. Using a newly developed synchrotron-based method we have determined the crystallite size distributions (CSD) of the gas hydrate in the sedimentary matrix confirming in a quantitative and statistically relevant manner the impressions from the tomographic reconstructions. It is noteworthy that the CSDs from synthetic hydrates are distinctly smaller than those of natural gas hydrates [1], which suggest that coarsening processes take place in the sedimentary matrix after the initial hydrate formation. Understanding the processes of formation and coarsening may eventually permit the determination of the age of gas hydrates in sedimentary matrices [2], which are largely unknown at present. Furthermore, the full micro-structural picture and its evolution will enable quantitative digital rock physics modeling to reveal poroelastic properties and in this way to support the exploration and exploitation of gas hydrate resources in the future. [1] Klapp S.A., Hemes S., Klein H., Bohrmann G., McDonald I., Kuhs W.F. Grain size measurements of natural gas hydrates. Marine Geology 2010; 274(1-4):85-94. [2] Klapp S.A., Klein H, Kuhs W.F. First determination of gas hydrate

  4. In situ NMR analysis of fluids contained in sedimentary rock

    PubMed

    de Swiet TM; Tomaselli; Hurlimann; Pines

    1998-08-01

    Limitations of resolution and absorption in standard chemical spectroscopic techniques have made it difficult to study fluids in sedimentary rocks. In this paper, we show that a chemical characterization of pore fluids may be obtained in situ by magic angle spinning (MAS) nuclear magnetic resonance (NMR), which is normally used for solid samples. 1H MAS-NMR spectra of water and crude oil in Berea sandstone show sufficient chemical shift resolution for a straightforward determination of the oil/water ratio. Copyright 1998 Academic Press.

  5. Functional materials analysis using in situ and in operando X-ray and neutron scattering

    PubMed Central

    Peterson, Vanessa K.; Papadakis, Christine M.

    2015-01-01

    In situ and in operando studies are commonplace and necessary in functional materials research. This review highlights recent developments in the analysis of functional materials using state-of-the-art in situ and in operando X-ray and neutron scattering and analysis. Examples are given covering a number of important materials areas, alongside a description of the types of information that can be obtained and the experimental setups used to acquire them. PMID:25866665

  6. Collagen bioengineered systems: in situ advanced optical spatiotemporal analysis

    NASA Astrophysics Data System (ADS)

    Hwang, Yu Jer; Lang, Xuye; Granelli, Joseph; Turgman, Cassandra C.; Gigante, Jackie; Lyubovitsky, Julia G.

    2014-05-01

    The architecture of collagen is important in maintenance and regeneration of higher vertebrates' tissues. We had been studying the changes to this architecture with in situ multi-photon optical microscopy that combines nonlinear optical phenomena of second harmonic generation (SHG) and two-photon fluorescence (TPF) signals from collagen hydrogels prepared from different collagen solid content, polymerized at different temperatures, with different ions as well as modified with reducing sugars. We incubated 2 g/l collagen hydrogels with 0.1 M fructose at 37 °C and after about 20 days observed a significant induction of in situ fluorescence. The twophoton fluorescence emission was centered at about 460 nm for 730 nm excitation wavelength and shifted to 480 nm when we changed the excitation wavelength to 790 nm. The one-photon fluorescence emission was centered at about 416 nm when excitation was 330 nm. It red shifted and split into two peaks centered at about 430 nm and 460 nm for 370 nm excitation; 460 nm peak became predominant for 385 nm excitation and further shifted to 470 nm for 390 nm excitation. SHG and TPF imaging showed restructuring of hydrogels upon this modification. We will discuss these findings within the context of our ongoing dermal wound repair research.

  7. Technology on In-Situ Gas Generation to Recover Residual Oil Reserves

    SciTech Connect

    Sayavur Bakhtiyarov

    2008-02-29

    of the in-situ generated CO{sub 2} gas. A set of core flood experiments were conducted to define effect of surfactant on recovery efficiency. The results demonstrated obvious advantages of the foamy system over the brine solution in order to achieve higher sweep efficiency and recovery coefficient. It is shown that a slug injection is not an efficient method for mixing GY and GF solutions and it can't generate considerable gas inside the slim-tube.

  8. Kinematic analysis of in situ measurement during chemical mechanical planarization process.

    PubMed

    Li, Hongkai; Wang, Tongqing; Zhao, Qian; Meng, Yonggang; Lu, Xinchun

    2015-10-01

    Chemical mechanical planarization (CMP) is the most widely used planarization technique in semiconductor manufacturing presently. With the aid of in situ measurement technology, CMP tools can achieve good performance and stable productivity. However, the in situ measurement has remained unexplored from a kinematic standpoint. The available related resources for the kinematic analysis are very limited due to the complexity and technical secret. In this paper, a comprehensive kinematic analysis of in situ measurement is provided, including the analysis model, the measurement trajectory, and the measurement time of each zone of wafer surface during the practical CMP process. In addition, a lot of numerical calculations are performed to study the influences of main parameters on the measurement trajectory and the measurement velocity variation of the probe during the measurement process. All the efforts are expected to improve the in situ measurement system and promote the advancement in CMP control system.

  9. Kinematic analysis of in situ measurement during chemical mechanical planarization process

    SciTech Connect

    Li, Hongkai; Wang, Tongqing; Zhao, Qian; Meng, Yonggang; Lu, Xinchun

    2015-10-15

    Chemical mechanical planarization (CMP) is the most widely used planarization technique in semiconductor manufacturing presently. With the aid of in situ measurement technology, CMP tools can achieve good performance and stable productivity. However, the in situ measurement has remained unexplored from a kinematic standpoint. The available related resources for the kinematic analysis are very limited due to the complexity and technical secret. In this paper, a comprehensive kinematic analysis of in situ measurement is provided, including the analysis model, the measurement trajectory, and the measurement time of each zone of wafer surface during the practical CMP process. In addition, a lot of numerical calculations are performed to study the influences of main parameters on the measurement trajectory and the measurement velocity variation of the probe during the measurement process. All the efforts are expected to improve the in situ measurement system and promote the advancement in CMP control system.

  10. In-situ observation for growth of hierarchical metal-organic frameworks and their self-sequestering mechanism for gas storage

    NASA Astrophysics Data System (ADS)

    Hyo Park, Jung; Min Choi, Kyung; Joon Jeon, Hyung; Jung Choi, Yoon; Ku Kang, Jeung

    2015-07-01

    Although structures with the single functional constructions and micropores were demonstrated to capture many different molecules such as carbon dioxide, methane, and hydrogen with high capacities at low temperatures, their feeble interactions still limit practical applications at room temperature. Herein, we report in-situ growth observation of hierarchical pores in pomegranate metal-organic frameworks (pmg-MOFs) and their self-sequestering storage mechanism, not observed for pristine MOFs. Direct observation of hierarchical pores inside the pmg-MOF was evident by in-situ growth X-ray measurements while self-sequestering storage mechanism was revealed by in-situ gas sorption X-ray analysis and molecular dynamics simulations. The results show that meso/macropores are created at the early stage of crystal growth and then enclosed by micropore crystalline shells, where hierarchical pores are networking under self-sequestering mechanism to give enhanced gas storage. This pmg-MOF gives higher CO2 (39%) and CH4 (14%) storage capacity than pristine MOF at room temperature, in addition to fast kinetics with robust capacity retention during gas sorption cycles, thus giving the clue to control dynamic behaviors of gas adsorption.

  11. In-situ observation for growth of hierarchical metal-organic frameworks and their self-sequestering mechanism for gas storage

    PubMed Central

    Hyo Park, Jung; Min Choi, Kyung; Joon Jeon, Hyung; Jung Choi, Yoon; Ku Kang, Jeung

    2015-01-01

    Although structures with the single functional constructions and micropores were demonstrated to capture many different molecules such as carbon dioxide, methane, and hydrogen with high capacities at low temperatures, their feeble interactions still limit practical applications at room temperature. Herein, we report in-situ growth observation of hierarchical pores in pomegranate metal-organic frameworks (pmg-MOFs) and their self-sequestering storage mechanism, not observed for pristine MOFs. Direct observation of hierarchical pores inside the pmg-MOF was evident by in-situ growth X-ray measurements while self-sequestering storage mechanism was revealed by in-situ gas sorption X-ray analysis and molecular dynamics simulations. The results show that meso/macropores are created at the early stage of crystal growth and then enclosed by micropore crystalline shells, where hierarchical pores are networking under self-sequestering mechanism to give enhanced gas storage. This pmg-MOF gives higher CO2 (39%) and CH4 (14%) storage capacity than pristine MOF at room temperature, in addition to fast kinetics with robust capacity retention during gas sorption cycles, thus giving the clue to control dynamic behaviors of gas adsorption. PMID:26155988

  12. Assessment of a multi-species in situ FTIR for precise atmospheric greenhouse gas observations

    NASA Astrophysics Data System (ADS)

    Hammer, S.; Griffith, D. W. T.; Konrad, G.; Vardag, S.; Caldow, C.; Levin, I.

    2013-05-01

    We thoroughly evaluate the performance of a multi-species, in situ Fourier transform infrared (FTIR) analyser with respect to high-accuracy needs for greenhouse gas monitoring networks. The in situ FTIR analyser is shown to measure CO2, CO, CH4 and N2O mole fractions continuously, all with better reproducibility than the inter-laboratory compatibility (ILC) goals, requested by the World Meteorological Organization (WMO) for the Global Atmosphere Watch (GAW) programme. Simultaneously determined δ13CO2 reaches reproducibility as good as 0.03‰. Second-order dependencies between the measured components and the thermodynamic properties of the sample, (temperature, pressure and flow rate) and the cross sensitivities among the sample constituents are investigated and quantified. We describe an improved sample delivery and control system that minimises the pressure and flow rate variations, making post-processing corrections for those quantities non-essential. Temperature disequilibrium effects resulting from the evacuation of the sample cell are quantified and improved by the usage of a faster temperature sensor. The instrument has proven to be linear for all measured components in the ambient concentration range. The temporal stability of the instrument is characterised on different time scales. Instrument drifts on a weekly time scale are only observed for CH4 (0.04 nmol mol-1 day-1) and δ13CO2 (0.02‰ day-1). Based on 10 months of continuously collected quality control measures, the long-term reproducibility of the instrument is estimated to ±0.016 μmol mol-1 CO2, ±0.03‰ δ13CO2, ±0.14 nmol mol-1 CH4, ±0.1 nmol mol-1 CO and ±0.04 nmol mol-1 N2O. We propose a calibration and quality control scheme with weekly calibrations of the instrument that is sufficient to reach WMO-GAW inter-laboratory compatibility goals.

  13. In situ gasification process for producing product gas enriched in carbon monoxide and hydrogen

    DOEpatents

    Capp, John P.; Bissett, Larry A.

    1978-01-01

    The present invention is directed to an in situ coal gasification process wherein the combustion zone within the underground coal bed is fed with air at increasing pressure to increase pressure and temperature in the combustion zone for forcing product gases and water naturally present in the coal bed into the coal bed surrounding the combustion zone. No outflow of combustion products occurs during the build-up of pressure and temperature in the combustion zone. After the coal bed reaches a temperature of about 2000.degree. F and a pressure in the range of about 100-200 psi above pore pressure the airflow is terminated and the outflow of the combustion products from the combustion zone is initiated. The CO.sub.2 containing gaseous products and the water bleed back into the combustion zone to react endothermically with the hot carbon of the combustion zone to produce a burnable gas with a relatively high hydrogen and carbon monoxide content. About 11 to 29 percent of the gas recovered from the combustion zone is carbon monoxide which is considerably better than the 4 to 10 percent carbon monoxide obtained by employing previously known coal gasification techniques.

  14. In situ structural analysis of Golgi intracisternal protein arrays

    PubMed Central

    Engel, Benjamin D.; Schaffer, Miroslava; Albert, Sahradha; Asano, Shoh; Plitzko, Jürgen M.; Baumeister, Wolfgang

    2015-01-01

    We acquired molecular-resolution structures of the Golgi within its native cellular environment. Vitreous Chlamydomonas cells were thinned by cryo-focused ion beam milling and then visualized by cryo-electron tomography. These tomograms revealed structures within the Golgi cisternae that have not been seen before. Narrow trans-Golgi lumina were spanned by asymmetric membrane-associated protein arrays that had ∼6-nm lateral periodicity. Subtomogram averaging showed that the arrays may determine the narrow central spacing of the trans-Golgi cisternae through zipper-like interactions, thereby forcing cargo to the trans-Golgi periphery. Additionally, we observed dense granular aggregates within cisternae and intracisternal filament bundles associated with trans-Golgi buds. These native in situ structures provide new molecular insights into Golgi architecture and function. PMID:26311849

  15. A Strategy for In Situ Analysis of the Martian Surface

    NASA Astrophysics Data System (ADS)

    Marshall, J. R.

    1996-03-01

    It is proposed that for future exploration of the martian surface with roving vehicles, surface-analytical (as opposed to meteorological or seismological) instruments on-board should aim, whenever possible, for a dual capability for both cursory and intense interrogation of sample materials. At the very least, the explorational platform itself should embody this capability within the suite of on-board instruments. The development of analytical instrumentation for planetary exploration commonly does not follow this philosophy. In essence, a roving vehicle's scientific payload should act as a surrogate geologist who has the capacity for site reconnaissance, but who also has a well-equipped backpack for conducting in situ analyses as desired. We are developing a field-deployable x-ray diffraction-fluorescence instrument that can perform the dual role required of the surrogate geologist.

  16. Method for in-situ calibration of electrophoretic analysis systems

    DOEpatents

    Liu, Changsheng; Zhao, Hequan

    2005-05-08

    An electrophoretic system having a plurality of separation lanes is provided with an automatic calibration feature in which each lane is separately calibrated. For each lane, the calibration coefficients map a spectrum of received channel intensities onto values reflective of the relative likelihood of each of a plurality of dyes being present. Individual peaks, reflective of the influence of a single dye, are isolated from among the various sets of detected light intensity spectra, and these can be used to both detect the number of dye components present, and also to establish exemplary vectors for the calibration coefficients which may then be clustered and further processed to arrive at a calibration matrix for the system. The system of the present invention thus permits one to use different dye sets to tag DNA nucleotides in samples which migrate in separate lanes, and also allows for in-situ calibration with new, previously unused dye sets.

  17. Novel Modified Optical Fibers for High Temperature In-Situ Miniaturized Gas Sensors in Advanced Fossil Energy Systems

    SciTech Connect

    Pickrell, Gary; Scott, Brian

    2014-06-30

    This report covers the technical progress on the program “Novel Modified Optical Fibers for High Temperature In-Situ Miniaturized Gas Sensors in Advanced Fossil Energy Systems”, funded by the National Energy Technology Laboratory of the U.S. Department of Energy, and performed by the Materials Science & Engineering and Electrical & Computer Engineering Departments at Virginia Tech, and summarizes technical progress from July 1st, 2005 –June 30th, 2014. The objective of this program was to develop novel fiber materials for high temperature gas sensors based on evanescent wave absorption in optical fibers. This project focused on two primary areas: the study of a sapphire photonic crystal fiber (SPCF) for operation at high temperature and long wavelengths, and a porous glass based fiber optic sensor for gas detection. The sapphire component of the project focused on the development of a sapphire photonic crystal fiber, modeling of the new structures, fabrication of the optimal structure, development of a long wavelength interrogation system, testing of the optical properties, and gas and temperature testing of the final sensor. The fabrication of the 6 rod SPCF gap bundle (diameter of 70μm) with a hollow core was successfully constructed with lead-in and lead-out 50μm diameter fiber along with transmission and gas detection testing. Testing of the sapphire photonic crystal fiber sensor capabilities with the developed long wavelength optical system showed the ability to detect CO2 at or below 1000ppm at temperatures up to 1000°C. Work on the porous glass sensor focused on the development of a porous clad solid core optical fiber, a hollow core waveguide, gas detection capabilities at room and high temperature, simultaneous gas species detection, suitable joining technologies for the lead-in and lead-out fibers and the porous sensor, sensor system sensitivity improvement, signal processing improvement, relationship between pore structure and fiber

  18. In situ measurements of gas/particle-phase transitions for atmospheric semivolatile organic compounds.

    PubMed

    Williams, Brent J; Goldstein, Allen H; Kreisberg, Nathan M; Hering, Susanne V

    2010-04-13

    An understanding of the gas/particle-phase partitioning of semivolatile compounds is critical in determining atmospheric aerosol formation processes and growth rates, which in turn affect global climate and human health. The Study of Organic Aerosol at Riverside 2005 campaign was performed to gain a better understanding of the factors responsible for aerosol formation and growth in Riverside, CA, a region with high concentrations of secondary organic aerosol formed through the phase transfer of low-volatility reaction products from the oxidation of precursor gases. We explore the ability of the thermal desorption aerosol gas chromatograph (TAG) to measure gas-to-particle-phase transitioning for several organic compound classes (polar and nonpolar) found in the ambient Riverside atmosphere by using in situ observations of several hundred semivolatile organic compounds. Here we compare TAG measurements to modeled partitioning of select semivolatile organic compounds. Although TAG was not designed to quantify the vapor phase of semivolatile organics, TAG measurements do distinguish when specific compounds are dominantly in the vapor phase, are dominantly in the particle phase, or have both phases present. Because the TAG data are both speciated and time-resolved, this distinction is sufficient to see the transition from vapor to particle phase as a function of carbon number and compound class. Laboratory studies typically measure the phase partitioning of semivolatile organic compounds by using pure compounds or simple mixtures, whereas hourly TAG phase partitioning measurements can be made in the complex mixture of thousands of polar/nonpolar and organic/inorganic compounds found in the atmosphere. PMID:20142511

  19. In-situ stress analysis of multilayer environmental barrier coatings.

    SciTech Connect

    Harder, B. J.; Almer, J.; Lee, K. N.; Faber, K. T.; Northwestern Univ.; Rolls-Royce Corp.

    2009-06-01

    The biaxial stress and thermal expansion of multilayer doped-aluminosilicate environmental barrier coatings were measured in situ during cooling using microfocused high-energy X-rays in transmission. Coating stresses during cooling from 1000 C were measured for as-sprayed and thermally cycled samples. In the as-sprayed state, tensile stresses as high as 75 MPa were measured in the doped-aluminosilicate topcoat at 375 C, after which a drop in the stress occurred accompanied by through-thickness cracking of the two outermost layers. After thermally cycling the samples, the stress in the topcoat was reduced to approximately 50 MPa, and there was no drop in stress upon cooling. This stress reduction was attributed to a crystallographic phase transformation of the topcoat and the accompanying change in thermal expansion coefficient. The addition of a doped aluminosilicate to the mullite layer did not lower the stress in the topcoat, but may offer increased durability due to an increased compressive stress.

  20. Analysis of Marine Stratocumulus Drizzle Variability Using In Situ Observations

    NASA Astrophysics Data System (ADS)

    Witte, M.; Chuang, P. Y.; Rossiter, D.

    2013-12-01

    Precipitation is an important factor in the dynamics and large-scale organization of marine stratocumulus, yet it remains poorly understood. We aim to elucidate the factors driving the amount and variability of marine stratocumulus drizzle using in situ observations. We use aircraft measurements from two regions: a) in the near-coastal region of Monterey, CA during the Physics of Stratocumulus Top (POST) project from July and August 2008 and b) in the near-coastal region of Iquique, Chile during the VAMOS Ocean-Cloud-Atmosphere-Land Study (VOCALS) from October 2008. Using these two different projects, we examine whether or not changes in conditions such as boundary layer depth, cloud top liquid water content, aerosol or drop concentrations, turbulence strength and inversion strength affect drizzle amount and variability. Interpreting which of these factors tend to associate most closely with various measures of drizzle intensity and variability will give insight into processes relevant to both precipitation formation and maintenance, and hopefully help explain how stratocumulus organize into the large-scale cellular patterns observed.

  1. In situ measurements of plasma properties during gas-condensation of Cu nanoparticles

    NASA Astrophysics Data System (ADS)

    Koten, M. A.; Voeller, S. A.; Patterson, M. M.; Shield, J. E.

    2016-03-01

    Since the mean, standard deviation, and modality of nanoparticle size distributions can vary greatly between similar input conditions (e.g., power and gas flow rate), plasma diagnostics were carried out in situ using a double-sided, planar Langmuir probe to determine the effect the plasma has on the heating of clusters and their final size distributions. The formation of Cu nanoparticles was analyzed using cluster-plasma physics, which relates the processes of condensation and evaporation to internal plasma properties (e.g., electron temperature and density). Monitoring these plasma properties while depositing Cu nanoparticles with different size distributions revealed a negative correlation between average particle size and electron temperature. Furthermore, the modality of the size distributions also correlated with the modality of the electron energy distributions. It was found that the maximum cluster temperature reached during plasma heating and the material's evaporation point regulates the growth process inside the plasma. In the case of Cu, size distributions with average sizes of 8.2, 17.3, and 24.9 nm in diameter were monitored with the Langmuir probe, and from the measurements made, the cluster temperatures for each deposition were calculated to be 1028, 1009, and 863 K. These values are then compared with the onset evaporation temperature of particles of this size, which was estimated to be 1059, 1068, and 1071 K. Thus, when the cluster temperature is too close to the evaporation temperature, less particle growth occurs, resulting in the formation of smaller particles.

  2. Release model for in situ vitrification large-field test off-gas treatment system

    SciTech Connect

    Pafford, D.J.; Tung, V.X.

    1992-03-01

    A conceptual model for the vapor and aerosol transport and deposition in the in situ vitrification large-field test off-gas system (OGS) has been developed. This model can be used to predict the emissions from the OGS under normal and off-normal conditions. Results generated by the model can be used to evaluate design and/or procedural modifications, define tests, and predict results. The OGS vapor and aerosol transport and deposition is modeled using the PULSE/MOD-ISV/VER 1.0.0 developmental computer code. Input data requirements for this code include the specific geometries of the OGS components; the composition, rate, and temperature of the vapors and aerosols entering the OGS; and the OGS component surface temperatures or heat fluxes. Currently, not all of these model inputs are available. Therefore, conceptual input parameters are developed. Using this input data, preliminary calculations with the code have been performed. These calculations include a demonstration that the code predicts convergent results, a comparison of predicted results with performance data for one of the OGS components, and a preliminary sensitivity study of the complete model.

  3. Gas injection to inhibit migration during an in situ heat treatment process

    DOEpatents

    Kuhlman, Myron Ira; Vinegar; Harold J.; Baker, Ralph Sterman; Heron, Goren

    2010-11-30

    Methods of treating a subsurface formation are described herein. Methods for treating a subsurface treatment area in a formation may include introducing a fluid into the formation from a plurality of wells offset from a treatment area of an in situ heat treatment process to inhibit outward migration of formation fluid from the in situ heat treatment process.

  4. Unmanned Aerial Mass Spectrometer Systems for In-Situ Volcanic Plume Analysis

    NASA Astrophysics Data System (ADS)

    Diaz, Jorge Andres; Pieri, David; Wright, Kenneth; Sorensen, Paul; Kline-Shoder, Robert; Arkin, C. Richard; Fladeland, Matthew; Bland, Geoff; Buongiorno, Maria Fabrizia; Ramirez, Carlos; Corrales, Ernesto; Alan, Alfredo; Alegria, Oscar; Diaz, David; Linick, Justin

    2015-02-01

    Technology advances in the field of small, unmanned aerial vehicles and their integration with a variety of sensor packages and instruments, such as miniature mass spectrometers, have enhanced the possibilities and applications of what are now called unmanned aerial systems (UAS). With such technology, in situ and proximal remote sensing measurements of volcanic plumes are now possible without risking the lives of scientists and personnel in charge of close monitoring of volcanic activity. These methods provide unprecedented, and otherwise unobtainable, data very close in space and time to eruptions, to better understand the role of gas volatiles in magma and subsequent eruption products. Small mass spectrometers, together with the world's smallest turbo molecular pump, have being integrated into NASA and University of Costa Rica UAS platforms to be field-tested for in situ volcanic plume analysis, and in support of the calibration and validation of satellite-based remote sensing data. These new UAS-MS systems are combined with existing UAS flight-tested payloads and assets, such as temperature, pressure, relative humidity, SO2, H2S, CO2, GPS sensors, on-board data storage, and telemetry. Such payloads are capable of generating real time 3D concentration maps of the Turrialba volcano active plume in Costa Rica, while remote sensing data are simultaneously collected from the ASTER and OMI space-borne instruments for comparison. The primary goal is to improve the understanding of the chemical and physical properties of emissions for mitigation of local volcanic hazards, for the validation of species detection and abundance of retrievals based on remote sensing, and to validate transport models.

  5. Unmanned aerial mass spectrometer systems for in-situ volcanic plume analysis.

    PubMed

    Diaz, Jorge Andres; Pieri, David; Wright, Kenneth; Sorensen, Paul; Kline-Shoder, Robert; Arkin, C Richard; Fladeland, Matthew; Bland, Geoff; Buongiorno, Maria Fabrizia; Ramirez, Carlos; Corrales, Ernesto; Alan, Alfredo; Alegria, Oscar; Diaz, David; Linick, Justin

    2015-02-01

    Technology advances in the field of small, unmanned aerial vehicles and their integration with a variety of sensor packages and instruments, such as miniature mass spectrometers, have enhanced the possibilities and applications of what are now called unmanned aerial systems (UAS). With such technology, in situ and proximal remote sensing measurements of volcanic plumes are now possible without risking the lives of scientists and personnel in charge of close monitoring of volcanic activity. These methods provide unprecedented, and otherwise unobtainable, data very close in space and time to eruptions, to better understand the role of gas volatiles in magma and subsequent eruption products. Small mass spectrometers, together with the world's smallest turbo molecular pump, have being integrated into NASA and University of Costa Rica UAS platforms to be field-tested for in situ volcanic plume analysis, and in support of the calibration and validation of satellite-based remote sensing data. These new UAS-MS systems are combined with existing UAS flight-tested payloads and assets, such as temperature, pressure, relative humidity, SO2, H2S, CO2, GPS sensors, on-board data storage, and telemetry. Such payloads are capable of generating real time 3D concentration maps of the Turrialba volcano active plume in Costa Rica, while remote sensing data are simultaneously collected from the ASTER and OMI space-borne instruments for comparison. The primary goal is to improve the understanding of the chemical and physical properties of emissions for mitigation of local volcanic hazards, for the validation of species detection and abundance of retrievals based on remote sensing, and to validate transport models. PMID:25588720

  6. In situ measurement of gas composition changes in radio frequency plasmas using a quartz sensor

    SciTech Connect

    Suzuki, Atsushi; Nonaka, Hidehiko

    2009-09-15

    A simple method using a quartz sensor (Q-sensor) was developed to observe gas composition changes in radio frequency (rf) plasmas. The output depends on the gases' absolute pressure, molecular weight, and viscosity. The pressure-normalized quartz sensor output depends only on the molecular weight and viscosity of the gas. Consequently, gas composition changes can be detected in the plasmas if a sensor can be used in the plasmas. Influences imparted by the plasmas on the sensor, such as those by reactive particles (e.g., radicals and ions), excited species, electrons, temperature, and electric potentials during measurements were investigated to test the applicability of this quartz sensor measurement to plasma. The Q-sensor measurement results for rf plasmas with argon, hydrogen, and their mixtures are reproducible, demonstrating that the Q-sensor measurement is applicable for plasmas. In this work, pressure- and temperature-normalized Q-sensor output (NQO) were used to obtain the gas composition information of plasma. Temperature-normalization of the Q-sensor output enabled quartz sensor measurements near plasma electrodes, where the quartz sensor temperature increases. The changes in NQO agreed with results obtained by gas analysis using a quadrupole mass spectrometer. Results confirmed that the change in NQO is mainly attributable to changes in the densities and kinds of gas molecules in the plasma gas phase, not by other extrinsic influences of plasma. For argon, hydrogen, and argon-hydrogen plasmas, these changes correspond to reduction in nitrogen, production of carbon monoxide, and dissociation of hydrogen molecules, respectively. These changes in NQO qualitatively and somewhat quantitatively agreed with results obtained using gas analysis, indicting that the measurement has a potential application to obtain the gas composition in plasmas without disturbing industrial plasma processes.

  7. In situ measurement of gas composition changes in radio frequency plasmas using a quartz sensor.

    PubMed

    Suzuki, Atsushi; Nonaka, Hidehiko

    2009-09-01

    A simple method using a quartz sensor (Q-sensor) was developed to observe gas composition changes in radio frequency (rf) plasmas. The output depends on the gases' absolute pressure, molecular weight, and viscosity. The pressure-normalized quartz sensor output depends only on the molecular weight and viscosity of the gas. Consequently, gas composition changes can be detected in the plasmas if a sensor can be used in the plasmas. Influences imparted by the plasmas on the sensor, such as those by reactive particles (e.g., radicals and ions), excited species, electrons, temperature, and electric potentials during measurements were investigated to test the applicability of this quartz sensor measurement to plasma. The Q-sensor measurement results for rf plasmas with argon, hydrogen, and their mixtures are reproducible, demonstrating that the Q-sensor measurement is applicable for plasmas. In this work, pressure- and temperature-normalized Q-sensor output (NQO) were used to obtain the gas composition information of plasma. Temperature-normalization of the Q-sensor output enabled quartz sensor measurements near plasma electrodes, where the quartz sensor temperature increases. The changes in NQO agreed with results obtained by gas analysis using a quadrupole mass spectrometer. Results confirmed that the change in NQO is mainly attributable to changes in the densities and kinds of gas molecules in the plasma gas phase, not by other extrinsic influences of plasma. For argon, hydrogen, and argon-hydrogen plasmas, these changes correspond to reduction in nitrogen, production of carbon monoxide, and dissociation of hydrogen molecules, respectively. These changes in NQO qualitatively and somewhat quantitatively agreed with results obtained using gas analysis, indicting that the measurement has a potential application to obtain the gas composition in plasmas without disturbing industrial plasma processes.

  8. Enhanced spectroscopic gas sensors using in-situ grown carbon nanotubes

    SciTech Connect

    De Luca, A.; Cole, M. T.; Milne, W. I.; Hopper, R. H.; Boual, S.; Ali, S. Z.; Warner, J. H.; Robertson, A. R.; Udrea, F.; Gardner, J. W.

    2015-05-11

    In this letter, we present a fully complementary-metal-oxide-semiconductor (CMOS) compatible microelectromechanical system thermopile infrared (IR) detector employing vertically aligned multi-walled carbon nanotubes (CNT) as an advanced nano-engineered radiation absorbing material. The detector was fabricated using a commercial silicon-on-insulator (SOI) process with tungsten metallization, comprising a silicon thermopile and a tungsten resistive micro-heater, both embedded within a dielectric membrane formed by a deep-reactive ion etch following CMOS processing. In-situ CNT growth on the device was achieved by direct thermal chemical vapour deposition using the integrated micro-heater as a micro-reactor. The growth of the CNT absorption layer was verified through scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. The functional effects of the nanostructured ad-layer were assessed by comparing CNT-coated thermopiles to uncoated thermopiles. Fourier transform IR spectroscopy showed that the radiation absorbing properties of the CNT adlayer significantly enhanced the absorptivity, compared with the uncoated thermopile, across the IR spectrum (3 μm–15.5 μm). This led to a four-fold amplification of the detected infrared signal (4.26 μm) in a CO{sub 2} non-dispersive-IR gas sensor system. The presence of the CNT layer was shown not to degrade the robustness of the uncoated devices, whilst the 50% modulation depth of the detector was only marginally reduced by 1.5 Hz. Moreover, we find that the 50% normalized absorption angular profile is subsequently more collimated by 8°. Our results demonstrate the viability of a CNT-based SOI CMOS IR sensor for low cost air quality monitoring.

  9. Enhanced spectroscopic gas sensors using in-situ grown carbon nanotubes

    NASA Astrophysics Data System (ADS)

    De Luca, A.; Cole, M. T.; Hopper, R. H.; Boual, S.; Warner, J. H.; Robertson, A. R.; Ali, S. Z.; Udrea, F.; Gardner, J. W.; Milne, W. I.

    2015-05-01

    In this letter, we present a fully complementary-metal-oxide-semiconductor (CMOS) compatible microelectromechanical system thermopile infrared (IR) detector employing vertically aligned multi-walled carbon nanotubes (CNT) as an advanced nano-engineered radiation absorbing material. The detector was fabricated using a commercial silicon-on-insulator (SOI) process with tungsten metallization, comprising a silicon thermopile and a tungsten resistive micro-heater, both embedded within a dielectric membrane formed by a deep-reactive ion etch following CMOS processing. In-situ CNT growth on the device was achieved by direct thermal chemical vapour deposition using the integrated micro-heater as a micro-reactor. The growth of the CNT absorption layer was verified through scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. The functional effects of the nanostructured ad-layer were assessed by comparing CNT-coated thermopiles to uncoated thermopiles. Fourier transform IR spectroscopy showed that the radiation absorbing properties of the CNT adlayer significantly enhanced the absorptivity, compared with the uncoated thermopile, across the IR spectrum (3 μm-15.5 μm). This led to a four-fold amplification of the detected infrared signal (4.26 μm) in a CO2 non-dispersive-IR gas sensor system. The presence of the CNT layer was shown not to degrade the robustness of the uncoated devices, whilst the 50% modulation depth of the detector was only marginally reduced by 1.5 Hz. Moreover, we find that the 50% normalized absorption angular profile is subsequently more collimated by 8°. Our results demonstrate the viability of a CNT-based SOI CMOS IR sensor for low cost air quality monitoring.

  10. Micro/Nano gas sensors: a new strategy towards in-situ wafer-level fabrication of high-performance gas sensing chips.

    PubMed

    Xu, Lei; Dai, Zhengfei; Duan, Guotao; Guo, Lianfeng; Wang, Yi; Zhou, Hong; Liu, Yanxiang; Cai, Weiping; Wang, Yuelin; Li, Tie

    2015-05-22

    Nano-structured gas sensing materials, in particular nanoparticles, nanotubes, and nanowires, enable high sensitivity at a ppb level for gas sensors. For practical applications, it is highly desirable to be able to manufacture such gas sensors in batch and at low cost. We present here a strategy of in-situ wafer-level fabrication of the high-performance micro/nano gas sensing chips by naturally integrating microhotplatform (MHP) with nanopore array (NPA). By introducing colloidal crystal template, a wafer-level ordered homogenous SnO2 NPA is synthesized in-situ on a 4-inch MHP wafer, able to produce thousands of gas sensing units in one batch. The integration of micromachining process and nanofabrication process endues micro/nano gas sensing chips at low cost, high throughput, and with high sensitivity (down to ~20 ppb), fast response time (down to ~1 s), and low power consumption (down to ~30 mW). The proposed strategy of integrating MHP with NPA represents a versatile approach for in-situ wafer-level fabrication of high-performance micro/nano gas sensors for real industrial applications.

  11. An in situ-satellite blended analysis of global sea surface salinity

    NASA Astrophysics Data System (ADS)

    Xie, P.; Boyer, T.; Bayler, E.; Xue, Y.; Byrne, D.; Reagan, J.; Locarnini, R.; Sun, F.; Joyce, R.; Kumar, A.

    2014-09-01

    The blended monthly sea surface salinity (SSS) analysis, called the NOAA "Blended Analysis of Surface Salinity" (BASS), is constructed for the 4 year period from 2010 to 2013. Three data sets are employed as inputs to the blended analysis: in situ SSS measurements aggregated and quality controlled by NOAA/NODC, and passive microwave (PMW) retrievals from both the National Aeronautics and Space Administration's (NASA) Aquarius/SAC-D and the European Space Agency's (ESA) Soil Moisture-Ocean Salinity (SMOS) satellites. The blended analysis comprises two steps. First, the biases in the satellite retrievals are removed through probability distribution function (PDF) matching against temporally spatially colocated in situ measurements. The blended analysis is then achieved through optimal interpolation (OI), where the analysis for the previous time step is used as the first guess while the in situ measurements and bias-corrected satellite retrievals are employed as the observations to update the first guess. Cross validations illustrate improved quality of the blended analysis, with reduction in bias and random errors over most of the global oceans as compared to the individual inputs. Large uncertainty, however, remains in high-latitude oceans and coastal regions where the in situ networks are sparse and current-generation satellite retrievals have limitations. Our blended SSS analysis shows good agreements with the NODC in situ-based analysis over most of the tropical and subtropical oceans, but large differences are observed for high-latitude oceans and along coasts. In the tropical oceans, the BASS is shown to have coherent variability with precipitation and evaporation associated with the evolution of the El Niño-Southern Oscillation (ENSO).

  12. The Hummingbird GC-IMS: In Situ Analysis of a Cometary Nucleus

    NASA Technical Reports Server (NTRS)

    Kojiro, Daniel R.; Carle, Glenn C.; Cohen, Martin J.; Wernlund, Roger F.; Stimac, Robert M.; Takeuchi, Norishige; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    Comets are of enormous scientific interest for many reasons. They are primitive bodies that date back to the earliest stages of solar system formation and, because of their small size and because they have been stored in the outer reaches of the solar system, their pristine nature has been preserved better than for any other class of body. They are extremely rich in highly volatile elements, many in the form of ices, and are richer in organic matter than any other known solar system body. It is strongly suspected that in addition to their content of primordial solar nebular material, they also incorporate unprocessed matter from the interstellar medium. Impacts by comets occur onto all the planets and satellites, often with major consequences (e.g., the dinosaur extinction event at the KIT boundary), or sometimes just providing a spectacular cosmic event (e.g., the collision of comet Shoemaker-Levy 9 with Jupiter). A mission to analyze a cometary nucleus must be capable of detecting and identifying over 30 molecular species among several different chemical groups. The Hummingbird Mission will rendezvous with, orbit, characterize, and make multiple descents to the nucleus of a comet. Hummingbird will employ a Gas Chromatograph - Ion Mobility Spectrometer (GC-IMS) as part-of a suite of sophisticated instruments for a comprehensive in situ elemental, molecular, and isotopic analysis of the comet.

  13. In situ production and analysis of Weissella confusa dextran in wheat sourdough.

    PubMed

    Katina, Kati; Maina, Ndegwa Henry; Juvonen, Riikka; Flander, Laura; Johansson, Liisa; Virkki, Liisa; Tenkanen, Maija; Laitila, Arja

    2009-10-01

    Several lactic acid bacteria belonging to the genera Leuconostoc, Lactobacillus, and Weissella have been introduced to wheat sourdough baking for in situ production of exopolysaccharides. This is considered a novel method for improving the shelf-life, volume and nutritional value of bread without additives. However, in situ production of exopolysaccharides during sourdough fermentation is challenged by simultaneous acidification due to metabolic activities of the bacteria, which may significantly diminish the positive technological impact of exopolysaccharides. In this study, the growth, activity and in situ production of dextran by Weissella confusa VTT E-90392 in wheat sourdoughs were investigated. Furthermore, the influence of dextran-enriched sourdoughs, at the addition level of 43%, on the subsequent bread quality was established. W. confusa efficiently produced dextran from the added sucrose in wheat sourdough without strong acid production. A new specific enzyme-assisted method for in situ analysis of dextran in sourdoughs was developed. With this method, we could for the first time proof significant (11-16 g/kg DW) production of polymeric dextran in sourdoughs. Concomitant formation of shorter isomaltooligosaccharides by W. confusa was also detected. The produced dextran significantly increased the viscosity of the sourdoughs. Application of dextran-enriched sourdoughs in bread baking provided mildly acidic wheat bread with improved volume (up to 10%) and crumb softness (25-40%) during 6 days of storage. Hence, W. confusa is a promising new strain for efficient in situ production of dextrans and isomaltooligosaccharides in sourdoughs without strong acidification.

  14. A meta-analysis comparing the toxicity of sediments in the laboratory and in situ.

    PubMed

    Hose, Grant C; Murray, Brad R; Park, Margaux L; Kelaher, Brendan P; Figueira, Will E

    2006-04-01

    Sediment toxicity tests in the laboratory are an important part of ecological risk assessments, yet how they relate to sediment toxicity in situ has rarely been explored. Using meta-analysis, we examined differences in the toxicity of sediment tested in the laboratory and in situ. Data from four published studies were subjected to rigorous statistical analyses. Overall, the toxicity of sediments in laboratory tests was substantially less than their toxicity in situ. Differences between laboratory and in situ toxicity, expressed using the log odds ratio effect size, varied significantly among published studies. Effect size increased significantly with increasing sediment toxicity, showing that the more toxic the sediment, the greater the disparity between laboratory and field toxicities. Our findings may not apply to all laboratory/field comparisons; however, we consider that the overlying water in field situations is a significant contributor to this relationship through additional contamination and toxicity. Our findings also have important implications for the use of laboratory tests to assess improvements in sediment quality and remediation, because changes in laboratory toxicity may not reflect the true improvements to sediment quality in situ.

  15. In Situ Space Gas Dynamic Measurements by the ROSINA Comet Pressure Sensor COPS Onboard Rosetta Spacecraft

    NASA Astrophysics Data System (ADS)

    Tzou, Chia-Yu; Altwegg, Kathrin; Fiethe, Björn; Gasc, Sébastien; Rubin, Martin

    2015-04-01

    Rosetta is part of the cornerstone missions executed by the European Space Agency. It is the first space mission to orbit and also land on a comet. The Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) is one of the core payloads on board of the Rosetta spacecraft [Balsiger et al, 2007]. ROSINA's main objective is to determine the major atmospheric and ionospheric composition in the coma and to investigate the gas dynamics around the comet. ROSINA consists of two mass spectrometers and a pressure sensor. The COmet Pressure Sensor (COPS) includes two gauges: the "nude gauge" measures total neutral density in the coma and the "ram gauge" measures the dynamic pressure of the cometary gas flux. The combination of these two gauges makes COPS capable to derive the gas dynamics (velocity and temperature) at the location of the spacecraft. Over several months Rosetta has been carrying out a close study of comet 67P/Churyumov-Gerasimenko. In early August 2014 COPS detected the faint and expanding atmosphere of the comet while it was still outside of 3.5 AU from the Sun. We will present ROSINA COPS observations of the evolution and gas dynamics of the cometary coma following these first observations until spring 2015. Reference: Balsiger, H. et al.: ROSINA-Rosetta Orbiter Spectrometer for Ion and Neutral Analysis, Space Science Reviews, Vol. 128, 745-801, 2007.

  16. Soil characterization by energy dispersive X-ray fluorescence: sampling strategy for in situ analysis.

    PubMed

    Custo, Graciela; Boeykens, Susana; Dawidowski, L; Fox, L; Gómez, D; Luna, F; Vázquez, Cristina

    2005-07-01

    This work describes a sampling strategy that will allow the use of portable EDXRF (energy dispersive X-ray fluorescence) instruments for "in situ" soil analysis. The methodology covers a general approach to planning field investigations for any type of environmental studies and it was applied for a soil characterization study in the zone of Campana, Argentina, by evaluating data coming from an EDXRF spectrometer with a radioisotope excitation source. Simulating non-treated sampled as "in situ" samples and a soil characterization for Campana area was intended. "In situ" EDXRF methodology is a powerful analytical modality with the advantage of providing data immediately, allowing a fast general screening of the soil composition. PMID:16038489

  17. Combined analysis of cervical smears. Cytopathology, image cytometry and in situ hybridization.

    PubMed

    Multhaupt, H; Bruder, E; Elit, L; Rothblat, I; Warhol, M

    1993-01-01

    This study was an attempt to correlate the Bethesda System of Papanicolaou smear classification with DNA content by image analysis and the presence of human papillomavirus (HPV) as determined by in situ hybridization. DNA histograms were classified as normal diploid, diploid proliferative, polyploid and aneuploid. HPV in situ hybridization was performed with a cocktail of probes specific to HPV types 6, 11, 16 and 18. There was a good correlation between normal cytology and normal DNA histograms. Cytologically normal smears with bacterial or fungal infections showed a high proliferation index. HPV infection correlated with DNA polyploidy but was seen in 15 of 29 smears classified as cytologically normal. Morphologically abnormal Papanicolaou smears correlated with aneuploid DNA content. Smears classified as intraepithelial neoplasia correlated with aneuploid DNA content in all 12 cases. Four of five cases cytologically suspicious for HPV infection had HPV by in situ hybridization.

  18. Optimization and Analysis of Laser Beam Machining Parameters for Al7075-TiB2 In-situ Composite

    NASA Astrophysics Data System (ADS)

    Manjoth, S.; Keshavamurthy, R.; Pradeep Kumar, G. S.

    2016-09-01

    The paper focuses on laser beam machining (LBM) of In-situ synthesized Al7075-TiB2 metal matrix composite. Optimization and influence of laser machining process parameters on surface roughness, volumetric material removal rate (VMRR) and dimensional accuracy of composites were studied. Al7075-TiB2 metal matrix composite was synthesized by in-situ reaction technique using stir casting process. Taguchi's L9 orthogonal array was used to design experimental trials. Standoff distance (SOD) (0.3 - 0.5mm), Cutting Speed (1000 - 1200 m/hr) and Gas pressure (0.5 - 0.7 bar) were considered as variable input parameters at three different levels, while power and nozzle diameter were maintained constant with air as assisting gas. Optimized process parameters for surface roughness, volumetric material removal rate (VMRR) and dimensional accuracy were calculated by generating the main effects plot for signal noise ratio (S/N ratio) for surface roughness, VMRR and dimensional error using Minitab software (version 16). The Significant of standoff distance (SOD), cutting speed and gas pressure on surface roughness, volumetric material removal rate (VMRR) and dimensional error were calculated using analysis of variance (ANOVA) method. Results indicate that, for surface roughness, cutting speed (56.38%) is most significant parameter followed by standoff distance (41.03%) and gas pressure (2.6%). For volumetric material removal (VMRR), gas pressure (42.32%) is most significant parameter followed by cutting speed (33.60%) and standoff distance (24.06%). For dimensional error, Standoff distance (53.34%) is most significant parameter followed by cutting speed (34.12%) and gas pressure (12.53%). Further, verification experiments were carried out to confirm performance of optimized process parameters.

  19. In-Situ Quantification of Methanotrophic Activity in a Landfill Cover Soil Using Gas Push-Pull Tests

    NASA Astrophysics Data System (ADS)

    Gomez, K. E.; Gonzalez-Gil, G.; Schroth, M. H.; Zeyer, J.

    2007-12-01

    Landfills are both a major anthropogenic source and a sink for the greenhouse gas CH4. Methanogenic bacteria produce CH4 during the anaerobic digestion of landfill waste, whereas, methanotrophic bacteria consume CH4 as it is transported through a landfill cover soil. Methanotrophs are thought to be ubiquitous in soils, but typically exist in large numbers at oxic/anoxic interfaces, close to anaerobic methane sources but exposed to oxygen required for metabolism. Accurate in-situ quantification of the sink strength of methanotrophs in landfill cover soils is needed for global carbon balances and for local emissions mitigation strategies. We measured in-situ CH4 concentrations at 30, 60, and 100 cm depth at 18 evenly spaced locations across a landfill cover soil. Furthermore, we performed Gas Push-Pull Tests (GPPTs) to estimate in-situ rates of methanotrophic activity in the cover soil. The GPPT is a gas-tracer test in which a gas mixture containing CH4, O2, and non-reactive tracer gases is injected (pushed) into the soil followed by extraction (pull) from the same location. Quantification of CH4 oxidation rates is based upon comparison of the breakthrough curves of CH4 and tracer gases. We present the results of a series of GPPTs conducted at two locations in the cover soil to assess the feasibility and reproducibility of this technique to quantify methanotrophic activity. Additional GPPTs were performed with a methanotrophic inhibitor in the injection gas mixture to confirm the appropriate choice of tracers to quantify CH4 oxidation. Estimated CH4 oxidation rate constants indicate that the cover soil contains a highly active methanotrophic community.

  20. Gas Evolution in Operating Lithium-Ion Batteries Studied In Situ by Neutron Imaging

    NASA Astrophysics Data System (ADS)

    Michalak, Barbara; Sommer, Heino; Mannes, David; Kaestner, Anders; Brezesinski, Torsten; Janek, Jürgen

    2015-10-01

    Gas generation as a result of electrolyte decomposition is one of the major issues of high-performance rechargeable batteries. Here, we report the direct observation of gassing in operating lithium-ion batteries using neutron imaging. This technique can be used to obtain qualitative as well as quantitative information by applying a new analysis approach. Special emphasis is placed on high voltage LiNi0.5Mn1.5O4/graphite pouch cells. Continuous gassing due to oxidation and reduction of electrolyte solvents is observed. To separate gas evolution reactions occurring on the anode from those associated with the cathode interface and to gain more insight into the gassing behavior of LiNi0.5Mn1.5O4/graphite cells, neutron experiments were also conducted systematically on other cathode/anode combinations, including LiFePO4/graphite, LiNi0.5Mn1.5O4/Li4Ti5O12 and LiFePO4/Li4Ti5O12. In addition, the data were supported by gas pressure measurements. The results suggest that metal dissolution in the electrolyte and decomposition products resulting from the high potentials adversely affect the gas generation, particularly in the first charge cycle (i.e., during graphite solid-electrolyte interface layer formation).

  1. Gas Evolution in Operating Lithium-Ion Batteries Studied In Situ by Neutron Imaging

    PubMed Central

    Michalak, Barbara; Sommer, Heino; Mannes, David; Kaestner, Anders; Brezesinski, Torsten; Janek, Jürgen

    2015-01-01

    Gas generation as a result of electrolyte decomposition is one of the major issues of high-performance rechargeable batteries. Here, we report the direct observation of gassing in operating lithium-ion batteries using neutron imaging. This technique can be used to obtain qualitative as well as quantitative information by applying a new analysis approach. Special emphasis is placed on high voltage LiNi0.5Mn1.5O4/graphite pouch cells. Continuous gassing due to oxidation and reduction of electrolyte solvents is observed. To separate gas evolution reactions occurring on the anode from those associated with the cathode interface and to gain more insight into the gassing behavior of LiNi0.5Mn1.5O4/graphite cells, neutron experiments were also conducted systematically on other cathode/anode combinations, including LiFePO4/graphite, LiNi0.5Mn1.5O4/Li4Ti5O12 and LiFePO4/Li4Ti5O12. In addition, the data were supported by gas pressure measurements. The results suggest that metal dissolution in the electrolyte and decomposition products resulting from the high potentials adversely affect the gas generation, particularly in the first charge cycle (i.e., during graphite solid-electrolyte interface layer formation). PMID:26496823

  2. Experience with in-situ gas measurement systems for monitoring power plant emissions

    SciTech Connect

    McGowan, G.F.; Karpinske, R.G.

    1995-12-31

    In-situ pollutant/diluent monitors have been used for continuous emission monitoring since the early `70s. Probe type in-situ analyzers have enjoyed considerable success in these applications. With the advent of the 1990 CAAA and the Acid Rain CEMS requirements, the old SM810/8100 style instruments were redesigned to meet these new requirements. This paper describes some of the notable improvements which have been made in the design of these instruments and the performance which has been achieved, operating under 40CFR75 regulations.

  3. In situ precipitation preparation of ZnO hollow spheres and their photocatalysis and gas-sensing properties

    NASA Astrophysics Data System (ADS)

    Jia, Xiaohua; Tian, Minggang; Liu, Yingying; Wu, Xiangyang; Song, Haojie

    2015-06-01

    ZnO hollow spheres were synthesized by in situ precipitation method in the presence of surfactant polyvinylpyrrolidone combined with subsequent calcination. The prepared ZnO was characterized using scanning electron microscopy, X-ray diffraction, high-resolution transmission electron microscopy. The results indicated that the prepared ZnO hollow spheres were well crystalline with wurtzite hexagonal phase. The formation mechanism of ZnO hollow spheres was discussed. Furthermore, the gas-sensing properties for detection of organic gas and photocatalytic activities for the degradation of rhodamine B (RhB) of the prepared ZnO hollow spheres were investigated. The results indicated that the prepared ZnO hollow spheres exhibited superior photocatalysis properties on decomposition of RhB and high gas-sensing properties for detection of acetone gas.

  4. In situ analysis of copper electrodeposition reaction using unilateral NMR sensor.

    PubMed

    Gomes, B F; Nunes, L M S; Lobo, C M S; Carvalho, A S; Cabeça, L F; Colnago, L A

    2015-12-01

    The uses of high-resolution NMR spectroscopy and imaging (MRI) to study electrochemical reactions in situ have greatly increased in the last decade. However, most of these applications are limited to specialized NMR laboratories and not feasible for routine analysis. Recently we have shown that a bench top, time domain NMR spectrometer can be used to monitor in situ copper electrodeposition reaction and the effect of Lorentz force in the reaction rate. However these spectrometers limit the cell size to the magnet gap and cannot be used with standard electrochemical cells. In this paper we are demonstrating that unilateral NMR sensor (UNMR), which does not limit sample size/volume, can be used to monitor electrodeposition of paramagnetic ions in situ. The copper electrodeposition reaction was monitored remotely and in situ, placing the electrochemical cell on top of the UNMR sensor. The Cu(2+) concentration was measured during three hours of the electrodeposition reactions, by using the transverse relaxation rate (R2) determined with the Carr-Purcell-Meiboom-Gill pulse sequence. The reaction rate increased fourfold when the reaction was performed in the presence of a magnetic field (in situ), in comparison to the reactions in the absence of the magnetic field (ex situ). The increase of reaction rate, in the presence of the UNMR magnet, was related to the magneto hydrodynamic force (FB) and magnetic field gradient force (F∇B). F∇B was calculated to be one order of magnitude stronger than FB. The UNMR sensor has several advantages for in situ measurements when compared to standard NMR spectrometers. It is a low cost, portable, open system, which does not limit sample size/volume and can be easily be adapted to standard electrochemical cells or large industrial reactors.

  5. In situ analysis of copper electrodeposition reaction using unilateral NMR sensor

    NASA Astrophysics Data System (ADS)

    Gomes, B. F.; Nunes, L. M. S.; Lobo, C. M. S.; Carvalho, A. S.; Cabeça, L. F.; Colnago, L. A.

    2015-12-01

    The uses of high-resolution NMR spectroscopy and imaging (MRI) to study electrochemical reactions in situ have greatly increased in the last decade. However, most of these applications are limited to specialized NMR laboratories and not feasible for routine analysis. Recently we have shown that a bench top, time domain NMR spectrometer can be used to monitor in situ copper electrodeposition reaction and the effect of Lorentz force in the reaction rate. However these spectrometers limit the cell size to the magnet gap and cannot be used with standard electrochemical cells. In this paper we are demonstrating that unilateral NMR sensor (UNMR), which does not limit sample size/volume, can be used to monitor electrodeposition of paramagnetic ions in situ. The copper electrodeposition reaction was monitored remotely and in situ, placing the electrochemical cell on top of the UNMR sensor. The Cu2+ concentration was measured during three hours of the electrodeposition reactions, by using the transverse relaxation rate (R2) determined with the Carr-Purcell-Meiboom-Gill pulse sequence. The reaction rate increased fourfold when the reaction was performed in the presence of a magnetic field (in situ), in comparison to the reactions in the absence of the magnetic field (ex situ). The increase of reaction rate, in the presence of the UNMR magnet, was related to the magneto hydrodynamic force (FB) and magnetic field gradient force (F∇B). F∇B was calculated to be one order of magnitude stronger than FB. The UNMR sensor has several advantages for in situ measurements when compared to standard NMR spectrometers. It is a low cost, portable, open system, which does not limit sample size/volume and can be easily be adapted to standard electrochemical cells or large industrial reactors.

  6. The Determination of Pesticidal and Non-Pesticidal Organotin Compounds by in situ Ethylation and Capillary Gas Chromatography with Pulsed Flame Photometric Detection

    EPA Science Inventory

    The concurrent determination of pesticidal and non-pesticidal organotin compounds in several water matrices, using a simultaneous in situ ethylation and liquid-liquid extraction followed by splitless injection mode capillary gas chromatography with pulsed flame photometric detect...

  7. The Determination of Pesticidal and Non-Pesticidal Organotin Compounds in Water Matrices by in situ Ethylation and Gas Chromatography with Pulsed Flame Photometric Detection

    EPA Science Inventory

    The concurrent determination of pesticidal and non-pesticidal organotin compounds in several water matrices, using a simultaneous in situ ethylation and liquid-liquid extraction followed by splitless injection mode capillary gas chromatography with pulsed flame photometric detect...

  8. Reactive landing of gas-phase ions as a tool for the fabrication of metal oxide surfaces for in situ phosphopeptide enrichment.

    PubMed

    Blacken, Grady R; Volný, Michael; Diener, Matthew; Jackson, Karl E; Ranjitkar, Pratistha; Maly, Dustin J; Turecek, Frantisek

    2009-06-01

    Zirconium, titanium, and hafnium oxide-coated stainless steel surfaces are fabricated by reactive landing of gas-phase ions produced by electrospray ionization of group IVB metal alkoxides. The surfaces are used for in situ enrichment of phosphopeptides before analysis by matrix-assisted laser desorption ionization (MALDI) mass spectrometry. To evaluate this method we characterized ZrO(2) (zirconia) surfaces by (1) comparison with the other group IVB metal oxides of TiO(2) (titania) and HfO(2) (hafnia), (2) morphological characterization by SEM image analysis, and (3) dependence of phosphopeptide enrichment on the metal oxide layer thickness. Furthermore, we evaluated the necessity of the reactive landing process for the construction of useful metal oxide surfaces by preparing surfaces by electrospray deposition of Zr, Ti, and Hf alkoxides directly onto polished metal surfaces at atmospheric pressure. Although all three metal oxide surfaces evaluated were capable of phosphopeptide enrichment from complex peptide mixtures, zirconia performed better than hafnia or titania as a result of morphological characteristics illustrated by the SEM analysis. Metal oxide coatings that were fabricated by atmospheric pressure deposition were still capable of in situ phosphopeptide enrichment, although with inferior efficiency and surface durability. We show that zirconia surfaces prepared by reactive landing of gas-phase ions can be a useful tool for high throughput screening of novel phosphorylation sites and quantitation of phosphorylation kinetics.

  9. VAPoR - Volatile Analysis by Pyrolysis of Regolith - an Instrument for In Situ Detection of Water, Noble Gases, and Organics on the Moon

    NASA Technical Reports Server (NTRS)

    ten Kate, I. L.; Cardiff, E. H.; Feng, S. H.; Holmes, V.; Malespin, C.; Stern, J. G.; Swindle, T. D.; Glavin, D. P.

    2010-01-01

    We present the Volatile Analysis by Pyrolysis of Regolith (VAPoR) instrument design and demonstrate the validity of an in situ pyrolysis mass spectrometer for evolved gas analyses of lunar and planetary regolith samples. In situ evolved gas analyses of the lunar regolith have not yet been carried out and no atmospheric or evolved gas measurements have been made at the lunar poles. VAPoR is designed to do both kinds of measurements, is currently under development at NASA's Goddard Space Flight Center, and will be able to heat powdered regolith samples or rock drill fines up to 1400 C in vacuo. To validate the instrument concept, evolved gas species released from different planetary analogs were determined as a function of temperature using a laboratory breadboard. Evolved gas measurements of an Apollo 16 regolith sample and a fragment of the carbonaceous meteorite Murchison were made by VAPoR and our results compared with existing data. The results imply that in situ evolved gas measurements of the lunar regolith at the polar regions by VAPoR will be a very powerful tool for identifying water and other volatile signatures of lunar or exogenous origin as potential resources for future human exploration.

  10. Role of in situ organic matter degradation and fluid flow in the global gas hydrate distribution: application of general functions

    NASA Astrophysics Data System (ADS)

    Pinero, E.; Hensen, C.; Marquardt, M.; Haeckel, M.; Wallmann, K. J.

    2010-12-01

    During the last decades several estimates of the global gas hydrate budget have been published. The published results range by several orders of magnitude and thus, the total gas hydrate inventory is still poorly known. In order to elucidate the global gas hydrate amount we applied a recently published transfer function that calculates the amount of gas hydrate produced by in situ generated methane through organic matter degradation (Marquardt et al., accepted). The transfer function was derived from a large set of systematic runs of a numerical diagenetic model (Wallmann et al., 2006) covering a wide range of environmental conditions that are typical for the continental margins. The transfer function only includes two variables: the accumulation rate of particulate organic carbon and the thickness of the gas hydrate stability zone. We tested various approaches to calculate both parameters on the global scale. The global grids used include seafloor bathymetry, TOC input, organic rain rate, bottom water temperature, geothermal gradient estimated from heat flow, sediment thickness, and age of the oceanic crust. The results obtained lead to the conclusion that only minor amounts of gas hydrates (<10 Gt of C) are formed by in situ methane production. An extended function considering fluid flow was developed applying the same transport-reaction model. The resulting global distribution map gives a total inventory of gas hydrate ranging from 400 to 2500 Gt of C. So far, some of our calculations are slightly lower than previously published results (e.g. Archer et al., 2009) and suggest that only <2 % of the global gas hydrate budget forms from an autochthonous source of methane. The results presented here suggest that where gas does not migrate into the gas hydrate stability zone only minor negligible concentrations of gas hydrate accumulate. References: Wallmann, K., Aloisi, G. Haeckel, M., Obzhirov, A., Pavlova, G., Tishchenko, P.: Kinetics of organic matter degradation

  11. Application of in situ stress estimation methods in wellbore stability analysis under isotropic and anisotropic conditions

    NASA Astrophysics Data System (ADS)

    Gholami, Raoof; Rasouli, Vamegh; Aadnoy, Bernt; Mohammadi, Ramin

    2015-08-01

    Estimation of in situ stresses is a key step in many petroleum engineering applications, ranging from wellbore stability to sanding analysis and hydraulic fracturing design. Direct techniques conventionally used to determine in situ stresses are indeed very time consuming and expensive. These measurements would also be restricted as to the depth of acquisition, and generalization of the results to entire rock masses may not yield representative results. In this paper, applications of three indirect methods-Zoback’s polygon, shear moduli, and poroelastic-are studied to assess their applicability in providing reliable stress estimation under isotropic and anisotropic conditions. Determination of elastic, strength, and in situ stress parameters according to the assumption of each method for one of the vertical wells drilled in south Iran indicated that the shear moduli method is an appropriate approach for prediction of maximum horizontal stress within an interval where sufficient field data including leak-off tests are acquired. However, the poroelastic method seems to be a better method in prediction of in situ stresses under anisotropic conditions. This might be due to the presence of excessive shale formations in subsurface layers, causing structural or intrinsic anisotropy-based methods such as poroelastic equations to deliver more accurate results. However, making general conclusions based on studying a single vertical wellbore may not be sufficient, and therefore further studies are required.

  12. Radon in soil gas--exhalation tests and in situ measurements.

    PubMed

    Lindmark, A; Rosen, B

    1985-10-01

    Radon in soil can move into buildings resulting in high radon daughter concentrations. The foundation of a dwelling should be adapted to the radon "risk" which is determined by the radon concentration and the air permeability of the soil. Different measuring procedures are discussed in this paper, both in situ measurements of radon content and laboratory tests on radon exhalation from different types of soils at different water contents. PMID:4081740

  13. In situ characterization of catalysts and membranes in a microchannel under high-temperature water gas shift reaction conditions

    NASA Astrophysics Data System (ADS)

    Cavusoglu, G.; Dallmann, F.; Lichtenberg, H.; Goldbach, A.; Dittmeyer, R.; Grunwaldt, J.-D.

    2016-05-01

    Microreactor technology with high heat transfer in combination with stable catalysts is a very attractive approach for reactions involving major heat effects such as methane steam reforming and to some extent, also the high temperature water gas shift (WGS) reaction. For this study Rh/ceria catalysts and an ultrathin hydrogen selective membrane were characterized in situ in a microreactor specially designed for x-ray absorption spectroscopic measurements under WGS conditions. The results of these experiments can serve as a basis for further development of the catalysts and membranes.

  14. Combining In-situ and In-transit Processing to Enable Extreme-Sscale Scientific Analysis

    SciTech Connect

    Bennett, Janine C.; Abbasi, Hasan; Bremer, Peer-Timo; Grout, Ray; Gyulassy, Attila; Jin, Tong; Klasky, Scott A; Kolla, Hemanth; Parashar, Manish; Pascucci, Valerio; Pebay, Philippe; Thompson, David; Yu, Hongfeng; Zhang, Fan; Chen, Jacqueline H

    2012-01-01

    With the onset of extreme-scale computing, I/O constraints make it increasingly difficult for scientists to save a sufficient amount of raw simulation data to persistent storage. One potential solution is to change the data analysis pipeline from a post-process centric to a concurrent approach based on either in-situ or in-transit processing. In this context computations are considered in-situ if they utilize the primary compute resources, while in-transit processing refers to offloading computations to a set of secondary resources using asynchronous data transfers. In this paper we explore the design and implementation of three common analysis techniques typically performed on large-scale scientific simulations: topological analysis, descriptive statistics, and visualization. We summarize algorithmic developments, describe a resource scheduling system to coordinate the execution of various analysis workflows, and discuss our implementation using the DataSpaces and ADIOS frameworks that support efficient data movement between in-situ and in-transit computations. We demonstrate the efficiency of our lightweight, flexible framework by deploying it on the Jaguar XK6 to analyze data generated by S3D, a massively parallel turbulent combustion code. Our framework allows scientists dealing with the data deluge at extreme scale to perform analyses at increased temporal resolutions, mitigate I/O costs, and significantly improve the time to insight.

  15. Method of estimating the amount of in situ gas hydrates in deep marine sediments

    USGS Publications Warehouse

    Lee, M.W.; Hutchinson, D.R.; Dillon, William P.; Miller, J.J.; Agena, W.F.; Swift, B.A.

    1993-01-01

    The bulk volume of gas hydrates in marine sediments can be estimated by measuring interval velocities and amplitude blanking of hydrated zones from true amplitude processed multichannel seismic reflection data. In general, neither velocity nor amplitude information is adequate to independently estimate hydrate concentration. A method is proposed that uses amplitude blanking calibrated by interval velocity information to quantify hydrate concentrations in the Blake Ridge area of the US Atlantic continental margin. On the Blake Ridge, blanking occurs in conjunction with relatively low interval velocities. The model that best explains this relation linearly mixes two end-member sediments: hydrated and unhydrated sediment. Hydrate concentration in the hydrate end-member can be calculated from a weighted equation that uses velocity estimated from the seismic data, known properties of the pure hydrate, and porosity inferred from a velocity-porosity relationship. Amplitude blanking can be predicted as the proportions of hydrated and unhydrated sediment change across a reflection boundary. Our analysis of a small area near DSDP 533 indicates that the amount of gas hydrates is about 6% in total volume when the interval velocity is used as a criterion and about 9.5% when amplitude information is used. This compares with a calculated value of about 8% derived from the only available measurement in DSDP 533. ?? 1993.

  16. In-situ source path contribution analysis of structure borne road noise

    NASA Astrophysics Data System (ADS)

    Elliott, A. S.; Moorhouse, A. T.; Huntley, T.; Tate, S.

    2013-11-01

    Source-path-contribution (SPC) analysis, also known as transfer path analysis (TPA), is a technique widely used in the automotive industry for rank ordering noise and vibration sources. The SPC approach is known to provide reliable diagnostic information but is time consuming to apply. In this paper, a faster SPC approach that allows all measurements to be performed in-situ is outlined and tested. For validation purposes a classic example consisting of a vehicle's suspension system (considered a vibration source) attached to a vehicle body (receiver) is analysed. It is found that structure borne noise inside the vehicle can be predicted well by either the conventional or the novel in-situ SPC approaches and that both methods give the same diagnostic information in terms of the rank ordering of path contributions. Thus, the new in-situ approach provides results at least as reliable as the conventional inverse SPC approach but has significant practical advantages in terms of reduced test time, transferability of data and flexibility in the location of the source-receiver interface. An additional investigation also demonstrates the feasibility of including rotational motions and moments in the analysis and it is shown that improved accuracy can be achieved as a result.

  17. In situ rheology and gas volume in Hanford double-shell waste tanks

    SciTech Connect

    Stewart, C.W.; Alzheimer, J.M.; Brewster, M.E.; Chen, G.; Reid, H.C.; Shepard, C.L.; Terrones, G.; Mendoza, R.E.

    1996-09-01

    This report is a detailed characterization of gas retention and release in 6 Hanford DS waste tanks. The results came from the ball rheometer and void fraction instrument in (flammable gas watch list) tanks SY-101, SY-103, AW-101, AN-103, AN-104, and AN-105 are presented. Instrument operation and derivation of data reduction methods are presented. Gas retention and release information is summarized for each tank and includes tank fill history and instrumentation, waste configuration, gas release, void fraction distribution, gas volumes, rheology, and photographs of the waste column from extruded core samples. Potential peak burn pressure is computed as a function of gas release fraction to portray the `hazard signature` of each tank. It is shown that two tanks remain well below the maximum allowable pressure, even if the entire gas content were released and ignited, and that none of the others present a hazard with their present gas release behavior.

  18. In Situ Measurement, Characterization, and Modeling of Two-Phase Pressure Drop Incorporating Local Water Saturation in PEMFC Gas Channels

    NASA Astrophysics Data System (ADS)

    See, Evan J.

    Proton Exchange Membrane Fuel Cells (PEMFCs) have been an area of focus as an alternative for internal combustion engines in the transportation sector. Water and thermal management techniques remain as one of the key roadblocks in PEMFC development. The ability to model two-phase flow and pressure drop in PEMFCs is of significant importance to the performance and optimization of PEMFCs. This work provides a perspective on the numerous factors that affect the two-phase flow in the gas channels and presents a comprehensive pressure drop model through an extensive in situ fuel cell investigation. The study focused on low current density and low temperature operation of the cell, as these conditions present the most challenging scenario for water transport in the PEMFC reactant channels. Tests were conducted using two PEMFCs that were representative of the actual full scale commercial automotive geometry. The design of the flow fields allowed visual access to both cathode and anode sides for correlating the visual observations to the two-phase flow patterns and pressure drop. A total of 198 tests were conducted varying gas diffusion layer (GDL), inlet humidity, current density, and stoichiometry; this generated over 1500 average pressure drop measurements to develop and validate two-phase models. A two-phase 1+1 D modeling scheme is proposed that incorporates an elemental approach and control volume analysis to provide a comprehensive methodology and correlation for predicting two-phase pressure drop in PEMFC conditions. Key considerations, such as condensation within the channel, consumption of reactant gases, water transport across the membrane, and thermal gradients within the fuel cell, are reviewed and their relative importance illustrated. The modeling scheme is shown to predict channel pressure drop with a mean error of 10% over the full range of conditions and with a mean error of 5% for the primary conditions of interest. The model provides a unique and

  19. NMR bioreactor development for live in-situ microbial functional analysis

    NASA Astrophysics Data System (ADS)

    Majors, Paul D.; McLean, Jeffrey S.; Scholten, Johannes C. M.

    2008-05-01

    A live, in-situ metabolomics capability was developed for prokaryotic cultures under controlled growth conditions. Toward this goal, a radiofrequency-transparent bioreactor was developed and integrated with a commercial wide-bore nuclear magnetic resonance (NMR) imaging spectrometer and a commercial bioreactor controller. Water suppressed 1H NMR spectroscopy was used to monitor glucose and fructose utilization and byproduct excretion by Eubacterium aggregans (an anaerobic bacterial species relevant for biofuel production) under controlled batch and continuous culture conditions. The resulting metabolite profiles (short chain organic acids and ethanol) and trends are consistent with existing knowledge of its metabolism. However, our study also showed that E. aggregans produces lactate end product in significant concentrations—a result not previously reported. The advantages of live in-situ microbial metabolomics analysis and its complementariness with functional genomics/systems biology methods are discussed.

  20. NMR bioreactor development for live in-situ microbial functional analysis

    SciTech Connect

    Majors, Paul D.; Mclean, Jeffrey S.; Scholten, Johannes C.

    2008-05-01

    A live in-situ metabolomics capability was developed for prokaryotic cultures under controlled-growth conditions. Toward this goal, a radiofrequency-transparent bioreactor was developed and integrated with a commercial wide-bore nuclear magnetic resonance (NMR) imaging spectrometer and a commercial bioreactor controller. Water suppressed 1H NMR spectroscopy was used to monitor glucose and fructose utilization and byproduct excretion by Eubacterium aggregans (an anaerobic bacterial species relevant for biofuels production) under controlled batch and continuous culture conditions. The resulting metabolite profiles (short chain organic acids and ethanol) and trends are consistent with existing knowledge of its metabolism. However, our study showed the Eubacterium aggregans produces lactate end product in significant concentrations – a result not previously reported. The advantages of live in-situ microbial metabolomics analysis and its complementariness with functional genomics / systems biology methods are discussed.

  1. Miniature Variable Pressure Scanning Electron Microscope for In-Situ Imaging and Chemical Analysis

    NASA Technical Reports Server (NTRS)

    Gaskin, Jessica A.; Jerman, Gregory; Gregory, Don; Sampson, Allen R.

    2012-01-01

    NASA Marshall Space Flight Center (MSFC) is leading an effort to develop a Miniaturized Variable Pressure Scanning Electron Microscope (MVP-SEM) for in-situ imaging and chemical analysis of uncoated samples. This instrument development will be geared towards operation on Mars and builds on a previous MSFC design of a mini-SEM for the moon (funded through the NASA Planetary Instrument Definition and Development Program). Because Mars has a dramatically different environment than the moon, modifications to the MSFC lunar mini-SEM are necessary. Mainly, the higher atmospheric pressure calls for the use of an electron gun that can operate at High Vacuum, rather than Ultra-High Vacuum. The presence of a CO2-rich atmosphere also allows for the incorporation of a variable pressure system that enables the in-situ analysis of nonconductive geological specimens. Preliminary testing of Mars meteorites in a commercial Environmental SEM(Tradmark) (FEI) confirms the usefulness of lowcurrent/low-accelerating voltage imaging and highlights the advantages of using the Mars atmosphere for environmental imaging. The unique capabilities of the MVP-SEM make it an ideal tool for pursuing key scientific goals of NASA's Flagship Mission Max-C; to perform in-situ science and collect and cache samples in preparation for sample return from Mars.

  2. Analysis of ocean in situ observations and web-based visualization

    NASA Astrophysics Data System (ADS)

    Barth, Alexander; Watelet, Sylvain; Troupin, Charles; Alvera Azcarate, Aida; Santinelli, Giorgio; Hendriksen, Gerrit; Giorgetti, Alessandra; Beckers, Jean-Marie

    2016-04-01

    The sparsity of observations poses a challenge common to various ocean science disciplines. Even for physical parameters where the spatial and temporal coverage is higher, current observational networks undersample a broad spectrum of scales. The situation is generally more severe for chemical and biological parameters because related sensors are less widely deployed. The analysis tool DIVA (Data-Interpolating Variational Analysis) is designed to generate gridded fields from in situ observations. DIVA has been applied to various physical (temperature and salinity), chemical (concentration of nitrate, nitrite and phosphate) and biological parameters (abundance of a species) in the context of different European projects (SeaDataNet, EMODnet Chemistry and EMODnet Biology). We show the technologies used to visualize the gridded fields based on the Web Map Services standard. Visualization of analyses from in situ observations provides a unique set of challenges since the accuracy of the analysed field is not spatially uniform as it strongly depends on the observations location. In addition, an adequate handling of depth and time dimensions is essential. Beside visualizing the gridded fields, access is also given to the underlying observations. It is thus also possible to view more detailed information about the variability of the observations. The in situ observation visualization service allows one to display vertical profiles and time series and it is built upon OGC standards (the Web Feature Service and Web Processing Services) and following recommendation from the INSPIRE directive.

  3. In situ analysis of Titan's tholins by Laser 2 steps Desorption Ionisation

    NASA Astrophysics Data System (ADS)

    Benilan, Y.; Carrasco, N.; Cernogora, G.; Gazeau, M.; Mahjoub, A.; Szopa, C.; Schwell, M.

    2013-12-01

    The main objective of the whole project developed in collaboration (LISA/LATMOS) is to provide a better understanding of the chemical composition of Titan aerosols laboratory analogs, called tholins, and thereby of their formation pathways. The tholins are produced in the PAMPRE reactor (French acronyme for Aerosols Microgravity Production by Reactives Plasmas) developed at LATMOS. These tholins are generated in levitation (wall effects are thus limited) in a low pressure radiofrequency plasma. Up to now, the determination of the physical and chemical properties of these tholins was achieved after their collection and ex-situ analysis by several methods. Their bulk composition was then determined but their insoluble part is still unknown. Other studies were performed after the transfer of the soluble part of the aerosols to different analytical instruments. Therefore, possible artifacts could have influenced the results. We present the SMARD (a French acronym for Mass Spectrometry of Aerosols by InfraRed Laser Desorption) program. A challenging issue of our work is to perform the soluble and unsoluble parts of PAMPRE tholins' analysis in real time and in situ. The coupling of the PAMPRE reactor to a unique instrument (Single Particle Laser Ablation Mass Spectrometry) developed at LISA should allow determining in real time and in situ the characteristics (chemical composition together with granulometry) of the nanometric aerosols. The later are introduced in the analytical instrument using an aerodynamic lens device. Their detection and aerodynamic diameter are determined using two continuous diode lasers operating at λ = 403 nm. Then, the L2DI (Laser 2 steps Desorption Ionisation) technique is used in order to access to the chemical composition of individual particles: they are vaporized using a 10 μm CO2 pulsed laser and the gas produced is then ionized by a 248 nm KrF Excimer laser. Finally, the molecular ions are analyzed by a 1 m linear time-of-flight mass

  4. Incidence and Outcomes of Anterior Chamber Gas Bubble during Femtosecond Flap Creation for Laser-Assisted In Situ Keratomileusis.

    PubMed

    Rush, Sloan W; Cofoid, Philip; Rush, Ryan B

    2015-01-01

    Purpose. To report the incidence and outcomes of anterior chamber gas bubble formation during femtosecond laser flap creation for laser-assisted in situ keratomileusis (LASIK). Methods. The charts of 2,886 consecutive eyes that underwent femtosecond LASIK from May 2011 through August 2014 were retrospectively reviewed. The incidence, preoperative characteristics, intraoperative details, and postoperative outcomes were analyzed in subjects developing anterior chamber gas bubble formation during the procedure. Results. A total of 4 cases (0.14%) developed anterior chamber gas bubble formation during femtosecond laser flap creation. In all four cases, the excimer laser was unable to successfully track the pupil immediately following the anterior chamber bubble formation, temporarily postponing the completion of the procedure. There was an ethnicity predilection of anterior chamber gas formation toward Asians (p = 0.0055). An uncorrected visual acuity of 20/20 was ultimately achieved in all four cases without further complications. Conclusions. Anterior chamber gas bubble formation during femtosecond laser flap creation for LASIK is an uncommon event that typically results in a delay in treatment completion; nevertheless, it does influence final positive visual outcome. PMID:25954511

  5. Incidence and Outcomes of Anterior Chamber Gas Bubble during Femtosecond Flap Creation for Laser-Assisted In Situ Keratomileusis.

    PubMed

    Rush, Sloan W; Cofoid, Philip; Rush, Ryan B

    2015-01-01

    Purpose. To report the incidence and outcomes of anterior chamber gas bubble formation during femtosecond laser flap creation for laser-assisted in situ keratomileusis (LASIK). Methods. The charts of 2,886 consecutive eyes that underwent femtosecond LASIK from May 2011 through August 2014 were retrospectively reviewed. The incidence, preoperative characteristics, intraoperative details, and postoperative outcomes were analyzed in subjects developing anterior chamber gas bubble formation during the procedure. Results. A total of 4 cases (0.14%) developed anterior chamber gas bubble formation during femtosecond laser flap creation. In all four cases, the excimer laser was unable to successfully track the pupil immediately following the anterior chamber bubble formation, temporarily postponing the completion of the procedure. There was an ethnicity predilection of anterior chamber gas formation toward Asians (p = 0.0055). An uncorrected visual acuity of 20/20 was ultimately achieved in all four cases without further complications. Conclusions. Anterior chamber gas bubble formation during femtosecond laser flap creation for LASIK is an uncommon event that typically results in a delay in treatment completion; nevertheless, it does influence final positive visual outcome.

  6. Nitrogen as an indicator of mass transfer during in-situ gas sparging.

    PubMed

    Balcke, Gerd U; Hahn, M; Oswald, Sascha E

    2011-09-25

    Aiming at the stimulation of intrinsic microbial activity, pulses of pure oxygen or pressurized air were recurrently injected into groundwater polluted with chlorobenzene. To achieve well-controlled conditions and intensive sampling, a large, vertical underground tank was filled with the local unconfined sandy aquifer material. In the course of two individual gas injections, one using pure oxygen and one using pressurized air, the mass transfer of individual gas species between trapped gas phase and groundwater was studied. Field data on the dissolved gas composition in the groundwater were combined with a kinetic model on gas dissolution and transport in porous media. Phase mass transfer of individual gas components caused a temporary enrichment of nitrogen, and to a lower degree of methane, in trapped gas leading to the formation of excess dissolved nitrogen levels downgradient from the dissolving gas phase. By applying a novel gas sampling method for dissolved gases in groundwater it was shown that dissolved nitrogen can be used as a partitioning tracer to indicate complete gas dissolution in porous media.

  7. On-line gas chromatographic analysis of airborne particles

    DOEpatents

    Hering, Susanne V.; Goldstein, Allen H.

    2012-01-03

    A method and apparatus for the in-situ, chemical analysis of an aerosol. The method may include the steps of: collecting an aerosol; thermally desorbing the aerosol into a carrier gas to provide desorbed aerosol material; transporting the desorbed aerosol material onto the head of a gas chromatography column; analyzing the aerosol material using a gas chromatograph, and quantizing the aerosol material as it evolves from the gas chromatography column. The apparatus includes a collection and thermal desorption cell, a gas chromatograph including a gas chromatography column, heated transport lines coupling the cell and the column; and a quantization detector for aerosol material evolving from the gas chromatography column.

  8. Residual gas analysis device

    DOEpatents

    Thornberg, Steven M.

    2012-07-31

    A system is provided for testing the hermeticity of a package, such as a microelectromechanical systems package containing a sealed gas volume, with a sampling device that has the capability to isolate the package and breach the gas seal connected to a pulse valve that can controllably transmit small volumes down to 2 nanoliters to a gas chamber for analysis using gas chromatography/mass spectroscopy diagnostics.

  9. In situ measurement of leaf chlorophyll concentration: analysis of the optical/absolute relationship.

    PubMed

    Parry, Christopher; Blonquist, J Mark; Bugbee, Bruce

    2014-11-01

    In situ optical meters are widely used to estimate leaf chlorophyll concentration, but non-uniform chlorophyll distribution causes optical measurements to vary widely among species for the same chlorophyll concentration. Over 30 studies have sought to quantify the in situ/in vitro (optical/absolute) relationship, but neither chlorophyll extraction nor measurement techniques for in vitro analysis have been consistent among studies. Here we: (1) review standard procedures for measurement of chlorophyll; (2) estimate the error associated with non-standard procedures; and (3) implement the most accurate methods to provide equations for conversion of optical to absolute chlorophyll for 22 species grown in multiple environments. Tests of five Minolta (model SPAD-502) and 25 Opti-Sciences (model CCM-200) meters, manufactured from 1992 to 2013, indicate that differences among replicate models are less than 5%. We thus developed equations for converting between units from these meter types. There was no significant effect of environment on the optical/absolute chlorophyll relationship. We derive the theoretical relationship between optical transmission ratios and absolute chlorophyll concentration and show how non-uniform distribution among species causes a variable, non-linear response. These results link in situ optical measurements with in vitro chlorophyll concentration and provide insight to strategies for radiation capture among diverse species.

  10. Application of meta-transcriptomics and -proteomics to analysis of in situ physiological state

    SciTech Connect

    Konopka, Allan; Wilkins, Michael J.

    2012-05-18

    Analysis of the growth-limiting factor or environmental stressors affecting microbes in situ is of fundamental importance but analytically difficult. Microbes can reduce in situ limiting nutrient concentrations to sub-micromolar levels, and contaminated ecosystems may contain multiple stressors. The patterns of gene or protein expression by microbes in nature can be used to infer growth limitations, because they are regulated in response to environmental conditions. Experimental studies under controlled conditions in the laboratory provide the physiological underpinnings for developing these physiological indicators. Although regulatory networks may differ among specific microbes, there are some broad principles that can be applied, related to limiting nutrient acquisition, resource allocation, and stress responses. As technologies for transcriptomics and proteomics mature, the capacity to apply these approaches to complex microbial communities will accelerate. Global proteomics has the particular advantage that it reflects expressed catalytic activities. Furthermore, the high mass accuracy of some proteomic approaches allows mapping back to specific microbial strains. For example, at the Rifle IFRC field site in Western Colorado, the physiological status of Fe(III)-reducing populations has been tracked over time. Members of a 'subsurface clade' within the Geobacter predominated during carbon amendment to the subsurface environment. At the functional level, proteomic identifications produced inferences regarding (i) temporal changes in anabolism and catabolism of acetate, (ii) the onset of N2 fixation when N became limiting, and (iii) expression of phosphate transporters during periods of intense growth. The application of these approaches in situ can lead to discovery of novel physiological adaptations.

  11. In situ ionic liquid dispersive liquid-liquid microextraction and direct microvial insert thermal desorption for gas chromatographic determination of bisphenol compounds.

    PubMed

    Cacho, Juan Ignacio; Campillo, Natalia; Viñas, Pilar; Hernández-Córdoba, Manuel

    2016-01-01

    A new procedure based on direct insert microvial thermal desorption injection allows the direct analysis of ionic liquid extracts by gas chromatography and mass spectrometry (GC-MS). For this purpose, an in situ ionic liquid dispersive liquid-liquid microextraction (in situ IL DLLME) has been developed for the quantification of bisphenol A (BPA), bisphenol Z (BPZ) and bisphenol F (BPF). Different parameters affecting the extraction efficiency of the microextraction technique and the thermal desorption step were studied. The optimized procedure, determining the analytes as acetyl derivatives, provided detection limits of 26, 18 and 19 ng L(-1) for BPA, BPZ and BPF, respectively. The release of the three analytes from plastic containers was monitored using this newly developed analytical method. Analysis of the migration test solutions for 15 different plastic containers in daily use identified the presence of the analytes at concentrations ranging between 0.07 and 37 μg L(-1) in six of the samples studied, BPA being the most commonly found and at higher concentrations than the other analytes.

  12. In situ microbial metabolism as a cause of gas anomalies in ice.

    PubMed

    Rohde, Robert A; Price, P Buford; Bay, Ryan C; Bramall, Nathan E

    2008-06-24

    Isolated spikes of anomalously high concentrations of N(2)O have been reported at depths in Greenland and Antarctic ice cores corresponding to narrow time intervals over the past approximately 10(5) years. Now, using a calibrated spectrofluorimeter to map protein-bound Trp, a proxy for microbes, versus depth in the 3,053-m GISP2 ice core, we find six depths at which localized spikes of high cell concentrations coincide with N(2)O spikes. We show that the excess gases are consistent with accumulation of in situ metabolic wastes during residence times of the excess microbes in the ice. Because of sparseness of N(2)O measurements and our spectrofluorimetry versus depth, the total number of microbially produced N(2)O spikes in GISP2 is probably much larger than six. Spikes of excess methanogens coincident with CH(4) spikes are found at three depths in the bottom 3% of GISP2, most likely because of methanogenic metabolism in the underlying silty ice, followed by turbulent flow of the lowest approximately 90 m of ice. The apparent rates of in situ production of N(2)O and CH(4) spikes by metabolism are observed to be consistent with a single activation energy, U, and maintain proportionality to exp(-U/RT) over the entire temperature range down to -40 degrees C. Fluorescence of nonmicrobial aerosols in GISP2 ice is distinguishable from microbial fluorescence by its different emission spectra. Our spectrofluorimetric scans throughout the GISP2 ice core lead us to conclude that both microbes and nonmicrobial aerosols are deposited in discontinuous bursts, which may provide a tool for studying wind storms in the distant past.

  13. In situ microbial metabolism as a cause of gas anomalies in ice

    PubMed Central

    Rohde, Robert A.; Price, P. Buford; Bay, Ryan C.; Bramall, Nathan E.

    2008-01-01

    Isolated spikes of anomalously high concentrations of N2O have been reported at depths in Greenland and Antarctic ice cores corresponding to narrow time intervals over the past ≈105 years. Now, using a calibrated spectrofluorimeter to map protein-bound Trp, a proxy for microbes, versus depth in the 3,053-m GISP2 ice core, we find six depths at which localized spikes of high cell concentrations coincide with N2O spikes. We show that the excess gases are consistent with accumulation of in situ metabolic wastes during residence times of the excess microbes in the ice. Because of sparseness of N2O measurements and our spectrofluorimetry versus depth, the total number of microbially produced N2O spikes in GISP2 is probably much larger than six. Spikes of excess methanogens coincident with CH4 spikes are found at three depths in the bottom 3% of GISP2, most likely because of methanogenic metabolism in the underlying silty ice, followed by turbulent flow of the lowest ≈90 m of ice. The apparent rates of in situ production of N2O and CH4 spikes by metabolism are observed to be consistent with a single activation energy, U, and maintain proportionality to exp(−U/RT) over the entire temperature range down to −40°C. Fluorescence of nonmicrobial aerosols in GISP2 ice is distinguishable from microbial fluorescence by its different emission spectra. Our spectrofluorimetric scans throughout the GISP2 ice core lead us to conclude that both microbes and nonmicrobial aerosols are deposited in discontinuous bursts, which may provide a tool for studying wind storms in the distant past. PMID:18550836

  14. In situ microbial metabolism as a cause of gas anomalies in ice.

    PubMed

    Rohde, Robert A; Price, P Buford; Bay, Ryan C; Bramall, Nathan E

    2008-06-24

    Isolated spikes of anomalously high concentrations of N(2)O have been reported at depths in Greenland and Antarctic ice cores corresponding to narrow time intervals over the past approximately 10(5) years. Now, using a calibrated spectrofluorimeter to map protein-bound Trp, a proxy for microbes, versus depth in the 3,053-m GISP2 ice core, we find six depths at which localized spikes of high cell concentrations coincide with N(2)O spikes. We show that the excess gases are consistent with accumulation of in situ metabolic wastes during residence times of the excess microbes in the ice. Because of sparseness of N(2)O measurements and our spectrofluorimetry versus depth, the total number of microbially produced N(2)O spikes in GISP2 is probably much larger than six. Spikes of excess methanogens coincident with CH(4) spikes are found at three depths in the bottom 3% of GISP2, most likely because of methanogenic metabolism in the underlying silty ice, followed by turbulent flow of the lowest approximately 90 m of ice. The apparent rates of in situ production of N(2)O and CH(4) spikes by metabolism are observed to be consistent with a single activation energy, U, and maintain proportionality to exp(-U/RT) over the entire temperature range down to -40 degrees C. Fluorescence of nonmicrobial aerosols in GISP2 ice is distinguishable from microbial fluorescence by its different emission spectra. Our spectrofluorimetric scans throughout the GISP2 ice core lead us to conclude that both microbes and nonmicrobial aerosols are deposited in discontinuous bursts, which may provide a tool for studying wind storms in the distant past. PMID:18550836

  15. An in-situ gas chromatography investigation into the suppression of oxygen gas evolution by coated amorphous cobalt-phosphate nanoparticles on oxide electrode

    PubMed Central

    Gim, Jihyeon; Song, Jinju; Kim, Sungjin; Jo, Jeonggeun; Kim, Seokhun; Yoon, Jaegu; Kim, Donghan; Hong, Suk-Gi; Park, Jin-Hwan; Mathew, Vinod; Han, Junhee; Song, Sun-Ju; Kim, Jaekook

    2016-01-01

    The real time detection of quantitative oxygen release from the cathode is performed by in-situ Gas Chromatography as a tool to not only determine the amount of oxygen release from a lithium-ion cell but also to address the safety concerns. This in-situ gas chromatography technique monitoring the gas evolution during electrochemical reaction presents opportunities to clearly understand the effect of surface modification and predict on the cathode stability. The oxide cathode, 0.5Li2MnO3∙0.5LiNi0.4Co0.2Mn0.4O2, surface modified by amorphous cobalt-phosphate nanoparticles (a-CoPO4) is prepared by a simple co-precipitation reaction followed by a mild heat treatment. The presence of a 40 nm thick a-CoPO4 coating layer wrapping the oxide powders is confirmed by electron microscopy. The electrochemical measurements reveal that the a-CoPO4 coated overlithiated layered oxide cathode shows better performances than the pristine counterpart. The enhanced performance of the surface modified oxide is attributed to the uniformly coated Co-P-O layer facilitating the suppression of O2 evolution and offering potential lithium host sites. Further, the formation of a stable SEI layer protecting electrolyte decomposition also contributes to enhanced stabilities with lesser voltage decay. The in-situ gas chromatography technique to study electrode safety offers opportunities to investigate the safety issues of a variety of nanostructured electrodes. PMID:27001370

  16. Two-stage in situ gas stripping for enhanced butanol fermentation and energy-saving product recovery

    SciTech Connect

    Xue, C; Zhao, JB; Liu, FF; Lu, CC; Yang, ST; Bai, FW

    2013-05-01

    Two-stage gas stripping for butanol recovery from acetone-butanol-ethanol (ABE) fermentation with Clostridium acetobutylicum JB200 in a fibrous bed bioreactor was studied. Compared to fermentation without in situ gas stripping, more ABE (10.0 g/L acetone, 19.2 g/L butanol, 1.7 g/L ethanol vs. 7.9 g/L acetone, 16.2 g/L butanol, 1.4 g/L ethanol) were produced, with a higher butanol yield (0.25 g/g vs. 0.20 g/g) and productivity (0.40 g/L.h vs. 0.30 g/L-h) due to reduced butanol inhibition. The first-stage gas stripping produced a condensate containing 175.6 g/L butanol (227.0 g/L ABE), which after phase separation formed an organic phase containing 612.3 g/L butanol (660.7 g/L ABE) and an aqueous phase containing 101.3 g/L butanol (153.2 g/L ABE). After second-stage gas stripping, a highly concentrated product containing 420.3 g/L butanol (532.3 g/L ABE) was obtained. The process is thus effective in producing high-titer butanol that can be purified with much less energy. (C) 2012 Elsevier Ltd. All rights reserved.

  17. Atmospheric methane at Zeppelin Station in Ny-Alesund: presentation and analysis of in situ measurements.

    PubMed

    Pedersen, Ine-Therese; Holmen, Kim; Hermansen, Ove

    2005-05-01

    In situ methane (CH(4)) measurement techniques and data from the Zeppelin Station in Ny-Alesund on Svalbard (N 78 degrees 54' E 11 degrees 53') on Mt. Zeppelin (475 m.a.s.l) are presented. The data span the time period from October 1998 to December 2003, though not continuously. The daily mean was calculated from 96 samples per day which are analysed by gas chromatography with flame ionisation detection. Details of the experimental methods and procedures are given. A harmonic function is fitted to the data with a constant trend and seasonal amplitude. The data are also presented in a regression plot showing the difference between the in situ measurements and flask measurements from the National Oceanic and Atmospheric Administration of the Climate Monitoring and Diagnostics Laboratory (NOAA/CMDL) in Boulder, Colorado (http://www.cmdl.noaa.gov/). The Zeppelin data show typical Arctic air characteristics with wintertime pollution episodes from Europe and Russia and a relatively calm summer state. PMID:15877171

  18. Atmospheric methane at Zeppelin Station in Ny-Alesund: presentation and analysis of in situ measurements.

    PubMed

    Pedersen, Ine-Therese; Holmen, Kim; Hermansen, Ove

    2005-05-01

    In situ methane (CH(4)) measurement techniques and data from the Zeppelin Station in Ny-Alesund on Svalbard (N 78 degrees 54' E 11 degrees 53') on Mt. Zeppelin (475 m.a.s.l) are presented. The data span the time period from October 1998 to December 2003, though not continuously. The daily mean was calculated from 96 samples per day which are analysed by gas chromatography with flame ionisation detection. Details of the experimental methods and procedures are given. A harmonic function is fitted to the data with a constant trend and seasonal amplitude. The data are also presented in a regression plot showing the difference between the in situ measurements and flask measurements from the National Oceanic and Atmospheric Administration of the Climate Monitoring and Diagnostics Laboratory (NOAA/CMDL) in Boulder, Colorado (http://www.cmdl.noaa.gov/). The Zeppelin data show typical Arctic air characteristics with wintertime pollution episodes from Europe and Russia and a relatively calm summer state.

  19. Analysis of in-situ rock joint strength using digital borehole scanner images

    SciTech Connect

    Thapa, B.B.

    1994-09-01

    The availability of high resolution digital images of borehole walls using the Borehole Scanner System has made it possible to develop new methods of in-situ rock characterization. This thesis addresses particularly new approaches to the characterization of in-situ joint strength arising from surface roughness. An image processing technique is used to extract the roughness profile from joints in the unrolled image of the borehole wall. A method for estimating in-situ Rengers envelopes using this data is presented along with results from using the method on joints in a borehole in porphyritic granite. Next, an analysis of the joint dilation angle anisotropy is described and applied to the porphyritic granite joints. The results indicate that the dilation angle of the joints studied are anisotropic at small scales and tend to reflect joint waviness as scale increases. A procedure to unroll the opposing roughness profiles to obtain a two dimensional sample is presented. The measurement of apertures during this process is shown to produce an error which increases with the dip of the joint. The two dimensional sample of opposing profiles is used in a new kinematic analysis of the joint shear stress-shear deformation behavior. Examples of applying these methods on the porphyritic granite joints are presented. The unrolled opposing profiles were used in a numerical simulation of a direct shear test using Discontinuous Deformation Analysis. Results were compared to laboratory test results using core samples containing the same joints. The simulated dilatancy and shear stress-shear deformation curves were close to the laboratory curves in the case of a joint in porphyritic granite.

  20. Analysis of In Situ Thermal Ion Measurements from the MICA Sounding Rocket

    NASA Astrophysics Data System (ADS)

    Fernandes, P. A.; Lynch, K. A.; Zettergren, M. D.; Hampton, D. L.; Fisher, L. E.; Powell, S. P.

    2014-12-01

    The MICA sounding rocket launched on 19 Feb. 2012 into several discrete, localized arcs in the wake of a westward traveling surge. In situ and ground-based observations provide a measured response of the ionosphere to preflight and localized auroral drivers. Initial analysis of the in situ thermal ion data indicate possible measurement of an ion conic at low altitude (< 325 km). In the low-energy regime, the response of the instrument varies from the ideal because the measured thermal ion population is sensitive to the presence of the instrument. The plasma is accelerated in the frame of the instrument due to flows, ram, and acceleration through the sheath which forms around the spacecraft. The energies associated with these processes are large compared to the thermal energy. Correct interpretation of thermal plasma measurements requires accounting for all of these plasma processes and the non-ideal response of the instrument in the low-energy regime. This is an experimental and modeling project which involves thorough analysis of ionospheric thermal ion data from the MICA campaign. Analysis includes modeling and measuring the instrument response in the low-energy regime as well as accounting for the complex sheath formed around the instrument. This results in a forward model in which plasma parameters of the thermal plasma are propagated through the sheath and instrument models, resulting in an output which matches the in situ measurement. In the case of MICA, we are working toward answering the question of the initiating source processes that result, at higher altitudes, in well-developed conics and outflow on auroral field lines.

  1. In Situ Eddy Analysis in a High-Resolution Ocean Climate Model.

    PubMed

    Woodring, Jonathan; Petersen, Mark; Schmeißer, Andre; Patchett, John; Ahrens, James; Hagen, Hans

    2016-01-01

    An eddy is a feature associated with a rotating body of fluid, surrounded by a ring of shearing fluid. In the ocean, eddies are 10 to 150 km in diameter, are spawned by boundary currents and baroclinic instabilities, may live for hundreds of days, and travel for hundreds of kilometers. Eddies are important in climate studies because they transport heat, salt, and nutrients through the world's oceans and are vessels of biological productivity. The study of eddies in global ocean-climate models requires large-scale, high-resolution simulations. This poses a problem for feasible (timely) eddy analysis, as ocean simulations generate massive amounts of data, causing a bottleneck for traditional analysis workflows. To enable eddy studies, we have developed an in situ workflow for the quantitative and qualitative analysis of MPAS-Ocean, a high-resolution ocean climate model, in collaboration with the ocean model research and development process. Planned eddy analysis at high spatial and temporal resolutions will not be possible with a postprocessing workflow due to various constraints, such as storage size and I/O time, but the in situ workflow enables it and scales well to ten-thousand processing elements. PMID:26353372

  2. In Situ Eddy Analysis in a High-Resolution Ocean Climate Model.

    PubMed

    Woodring, Jonathan; Petersen, Mark; Schmeißer, Andre; Patchett, John; Ahrens, James; Hagen, Hans

    2016-01-01

    An eddy is a feature associated with a rotating body of fluid, surrounded by a ring of shearing fluid. In the ocean, eddies are 10 to 150 km in diameter, are spawned by boundary currents and baroclinic instabilities, may live for hundreds of days, and travel for hundreds of kilometers. Eddies are important in climate studies because they transport heat, salt, and nutrients through the world's oceans and are vessels of biological productivity. The study of eddies in global ocean-climate models requires large-scale, high-resolution simulations. This poses a problem for feasible (timely) eddy analysis, as ocean simulations generate massive amounts of data, causing a bottleneck for traditional analysis workflows. To enable eddy studies, we have developed an in situ workflow for the quantitative and qualitative analysis of MPAS-Ocean, a high-resolution ocean climate model, in collaboration with the ocean model research and development process. Planned eddy analysis at high spatial and temporal resolutions will not be possible with a postprocessing workflow due to various constraints, such as storage size and I/O time, but the in situ workflow enables it and scales well to ten-thousand processing elements.

  3. Nuclear spectroscopy for in situ soil elemental analysis: Monte Carlo simulations

    SciTech Connect

    Wielopolski L.; Doron, O.

    2012-07-01

    We developed a model to simulate a novel inelastic neutron scattering (INS) system for in situ non-destructive analysis of soil using standard Monte Carlo Neutron Photon (MCNP5a) transport code. The volumes from which 90%, 95%, and 99% of the total signal are detected were estimated to be 0.23 m{sup 3}, 0.37 m{sup 3}, and 0.79 m{sup 3}, respectively. Similarly, we assessed the instrument's sampling footprint and depths. In addition we discuss the impact of the carbon's depth distribution on sampled depth.

  4. An atomic layer deposition chamber for in situ x-ray diffraction and scattering analysis

    SciTech Connect

    Geyer, Scott M.; Methaapanon, Rungthiwa; Kim, Woo-Hee; Bent, Stacey F.; Johnson, Richard W.; Van Campen, Douglas G.; Metha, Apurva

    2014-05-15

    The crystal structure of thin films grown by atomic layer deposition (ALD) will determine important performance properties such as conductivity, breakdown voltage, and catalytic activity. We report the design of an atomic layer deposition chamber for in situ x-ray analysis that can be used to monitor changes to the crystal structural during ALD. The application of the chamber is demonstrated for Pt ALD on amorphous SiO{sub 2} and SrTiO{sub 3} (001) using synchrotron-based high resolution x-ray diffraction, grazing incidence x-ray diffraction, and grazing incidence small angle scattering.

  5. In-Situ Analysis of Gradient Trajectories in a Reactive Turbulent Shear Flow

    NASA Astrophysics Data System (ADS)

    Dietzsch, Felix; Gauding, Michael; Hasse, Christian

    2015-11-01

    Most understanding of turbulent fine-scale mixing has been gained from conditional statistics. Conditional statistics are examined along gradient trajectories, which constitute a natural, intrinsic coordinate system of the underlaying scalar field. Statistics along gradient trajectories contain information about the temporal mechanism of turbulent mixing and combustion. Analyzing these statistics is an important step to understand the transient behaviour of the interaction between turbulence and chemistry. The tracking of gradient trajectories is very challenging and has to be conducted in-situ in order to capture the smallest time-scales. The analysis is based on a direct numerical simulation of a turbulent diffusion flame exhibiting extinction and reignition.

  6. Zeolites as nanoporous, gas-sensitive materials for in situ monitoring of DeNO(x)-SCR.

    PubMed

    Simons, Thomas; Simon, Ulrich

    2012-01-01

    In a proof-of-concept study we demonstrate in situ reaction monitoring of DeNO(x)-SCR on proton-conducting zeolites serving as catalyst and gas sensor at the same time. By means of temperature-dependent impedance spectroscopy we found that the thermally induced NH(3) desorption in H-form and in Fe-loaded zeolite H-ZSM-5 follow the same process, while a remarkable difference under DeNO(x)-SCR reaction conditions was found. The Fe-loaded catalyst shows a significantly lower onset temperature, and time-dependent measurements suggest different SCR reaction mechanisms for the two catalysts tested. These results may help in the development of catalysts for the reduction of NO(x) emissions and ammonia consumption, and provide insight into the elementary catalytic process promoting a full description of the NH(3)-SCR reaction system.

  7. In situ X-ray pair distribution function analysis of geopolymer gel nanostructure formation kinetics.

    PubMed

    White, Claire E; Provis, John L; Bloomer, Breaunnah; Henson, Neil J; Page, Katharine

    2013-06-14

    With the ever-increasing environmentally-driven demand for technologically advanced structural materials, geopolymer cement is fast becoming a viable alternative to traditional cements due to its proven engineering characteristics and the reduction in CO2 emitted during manufacturing (as much as 80% less CO2 emitted in manufacture, compared to ordinary Portland cement). Nevertheless, much remains unknown regarding the kinetics of reaction responsible for nanostructural evolution during the geopolymerisation process. Here, in situ X-ray total scattering measurements and pair distribution function (PDF) analysis are used to quantify the extent of reaction as a function of time for alkali-activated metakaolin/slag geopolymer binders, including the impact of various activators (alkali hydroxide/silicate) on the kinetics of the geopolymerisation reaction. Quantifying the reaction process in situ from X-ray PDF data collected during the initial ten hours can provide an estimate of the total reaction extent, but when combined with data obtained at longer times (128 days here) enables more accurate determination of the overall rate of reaction. To further assess the initial stages of the geopolymerisation reaction process, a pseudo-single step first order rate equation is fitted to the extent of reaction data, which reveals important mechanistic information regarding the role of free silica in the activators in the evolution of the binder systems. Hence, it is shown that in situ X-ray PDF analysis is an ideal experimental local structure tool to probe the reaction kinetics of complex reacting systems involving transitions between disordered/amorphous phases, of which geopolymerisation is an important example.

  8. In situ X-ray pair distribution function analysis of geopolymer gel nanostructure formation kinetics.

    PubMed

    White, Claire E; Provis, John L; Bloomer, Breaunnah; Henson, Neil J; Page, Katharine

    2013-06-14

    With the ever-increasing environmentally-driven demand for technologically advanced structural materials, geopolymer cement is fast becoming a viable alternative to traditional cements due to its proven engineering characteristics and the reduction in CO2 emitted during manufacturing (as much as 80% less CO2 emitted in manufacture, compared to ordinary Portland cement). Nevertheless, much remains unknown regarding the kinetics of reaction responsible for nanostructural evolution during the geopolymerisation process. Here, in situ X-ray total scattering measurements and pair distribution function (PDF) analysis are used to quantify the extent of reaction as a function of time for alkali-activated metakaolin/slag geopolymer binders, including the impact of various activators (alkali hydroxide/silicate) on the kinetics of the geopolymerisation reaction. Quantifying the reaction process in situ from X-ray PDF data collected during the initial ten hours can provide an estimate of the total reaction extent, but when combined with data obtained at longer times (128 days here) enables more accurate determination of the overall rate of reaction. To further assess the initial stages of the geopolymerisation reaction process, a pseudo-single step first order rate equation is fitted to the extent of reaction data, which reveals important mechanistic information regarding the role of free silica in the activators in the evolution of the binder systems. Hence, it is shown that in situ X-ray PDF analysis is an ideal experimental local structure tool to probe the reaction kinetics of complex reacting systems involving transitions between disordered/amorphous phases, of which geopolymerisation is an important example. PMID:23450172

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

    PubMed

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

    2015-04-01

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

  10. In situ hybridization analysis of human papillomavirus DNA in oral mucosal lesions.

    PubMed

    Zeuss, M S; Miller, C S; White, D K

    1991-06-01

    Commercial biotinylated DNA probes specific for human papillomavirus (HPV) types 6 and 11; 16 and 18; and 31, 33, and 35 were used for in situ hybridization analysis of 105 oral mucosal specimens from 5 cases of verruca vulgaris, 15 cases of condyloma acuminatum, 30 cases of squamous papilloma, 20 cases of hyperkeratosis/acanthosis, 15 cases of epithelial dysplasia, 5 cases of carcinoma in situ, and 15 cases of squamous cell carcinoma. Positive hybridization signals were found in 26 specimens (24.8%). Only HPV-6/11 was detected. HPV DNA occurred significantly more often (p less than 0.005, chi-square analysis) in condyloma acuminatum (100%) and verruca vulgaris (100%) than squamous papilloma (13.3%), hyperkeratotic/acanthotic lesions (10%), and malignant and premalignant lesions (0%). The tongue (19.1%) and labial epithelium (17.1%) were infected most frequently. Nuclear reaction products indicating HPV infection were associated primarily with koilocytes. These results demonstrate the usefulness of commercial biotinylated probes for HPV DNA analysis in routine paraffin-embedded lesion specimens. They confirm HPV involvement in benign lesions of the oral mucosa but fail to associate HPV infection with oral cancer and precancer.

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

    PubMed

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

    2015-04-01

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

  12. In situ mass analysis of particles by surface ionization mass spectrometry

    NASA Technical Reports Server (NTRS)

    Lassiter, W. S.; Moen, A. L.

    1974-01-01

    A qualitative study of the application of surface ionization and mass spectrometry to the in situ detection and constituent analysis of atmospheric particles was conducted. The technique consists of mass analysis of ions formed as a result of impingement of a stream of particles on a hot filament where, it is presumed, surface ionization takes place. Laboratory air particles containing K, Ca, and possibly hydrocarbons were detected. Other known particles such as Al2O3, Pb(NO3)2, and Cr2O3 were analyzed by detecting the respective metal atoms making up the particles. In some cases, mass numbers indicative of compounds making up the particles were detected showing surface ionization of particles sometimes leads to chemical analysis as well as to elemental analysis. Individual particles were detected, and it was shown that the technique is sensitive to Al2O3 particles with a mass of a few nanograms.

  13. In situ experiments of geothermal well stimulation using gas fracturing technology

    SciTech Connect

    Chu, T.Y.; Warpinski, N.; Jacobson, R.D.

    1988-07-01

    The results of an experimental study of gas fracturing technology for geothermal well stimulation demonstrated that multiple fractures could be created to link water-filled boreholes with existing fractures. The resulting fracture network and fracture interconnections were characterized by mineback as well as flow tests. Commercial oil field fracturing tools were used successfully in these experiments. Simple scaling laws for gas fracturing and a brief discussion of the application of this technique to actual geothermal well stimulation are presented. 10 refs., 42 figs., 4 tabs.

  14. Gas-driven filter pressing in magmas: insights into in-situ melt segregation from crystal mushes

    NASA Astrophysics Data System (ADS)

    Pistone, M.; Arzilli, F.; Dobson, K. J.; Cordonnier, B.; Reusser, E.; Ulmer, P.; Marone, F.; Whittington, A. G.; Mancini, L.; Fife, J.; Blundy, J. D.

    2015-12-01

    Gas-driven filter pressing is the process of melt expulsion from a volatile-saturated crystal mush, induced by the buildup and subsequent release of gas pressure. Filter pressing is inferred to play a major role in magma fractionation at shallow depths (<10 km) by moving melt and gas relative to the solid, crystalline framework. However, the magmatic conditions at which this process operates remain poorly constrained. We present novel experimental data that illustrate how the crystal content of the mush affects the ability of gas-driven filter pressing to segregate melt. Hydrous haplogranite (2.1 wt% water in the melt) and dacite (4.2 wt% water in the melt) crystal mushes, with a wide range of crystallinities (34-80 vol% crystals), were investigated using in-situ, high temperature (500-800 °C) synchrotron X-ray tomographic microscopy with high spatial (3 micron/pixel) and temporal resolution (~8 s per 3D data set). The experimental results show that gas-driven filter pressing operates only below the maximum packing of bubbles and crystals (~74 vol%). Above this threshold, the mush tends to fracture and gas escapes via fractures. Therefore, the efficiency of gas-driven filter pressing is promoted close to the percolation threshold and in situations where a mush inflates slowly relative to build-up of pressure and expulsion of melt. Such observations offer a likely explanation for the production of eruptible, crystal-poor magmas within Earth's crust. Figure = Synchrotron X-ray tomographic microscopy 3D renderings of representative haplogranite (A-D) and dacite (E-H) samples, with different crystal (Φ) and bubble fractions (β) at representative temperatures and experimental times (t, in minutes). Black objects are bubbles and fractures; dark gray field is silicic glass/melt; light gray objects are corundum crystals in haplogranite sample, and quartz in dacite sample. White and black arrows indicate representative fractures and directions of melt expulsion during

  15. Laser-based mass spectrometry for in situ chemical composition analysis of planetary surfaces

    NASA Astrophysics Data System (ADS)

    Frey, Samira; Neuland, Maike B.; Grimaudo, Valentine; Moreno-García, Pavel; Riedo, Andreas; Tulej, Marek; Broekmann, Peter; Wurz, Peter

    2016-04-01

    Mass spectrometry is an important analytical technique in space research. The chemical composition of planetary surface material is a key scientific question on every space mission to a planet, moon or asteroid. Chemical composition measurements of rocky material on the surface are of great importance to understand the origin and evolution of the planetary body.[1] A miniature laser ablation/ionisation reflectron- type time-of-flight mass spectrometer (instrument name LMS) was designed and built at the University of Bern for planetary research.[2] Despite its small size and light weight, the LMS instrument still maintains the same capabilities as large laboratory systems, which makes it suitable for its application on planetary space missions.[3-5] The high dynamic range of about eight orders of magnitude, high lateral (μm-level) and vertical (sub-nm level) resolution and high detection sensitivity for almost all elements (10 ppb, atomic fraction) make LMS a versatile instrument for various applications. LMS is a suitable instrument for in situ measurements of elemental and isotope composition with high precision and accuracy. Measurements of Pb- isotope abundances can be used for dating of planetary material. Measurements of bio-relevant elements allow searching for past or present life on a planetary surface. The high spatial resolution, both in lateral and vertical direction, is of considerable interest, e.g. for analysis of inhomogeneous, extraterrestrial samples as well as weathering processes of planetary material. References [1] P. Wurz, D. Abplanalp, M. Tulej, M. Iakovleva, V.A. Fernandes, A. Chumikov, and G. Managadze, "Mass Spectrometric Analysis in Planetary Science: Investigation of the Surface and the Atmosphere", Sol. Sys. Res., 2012, 46, 408. [2] U. Rohner, J.A. Whitby, P. Wurz, "A miniature laser ablation time of flight mass spectrometer for in situ planetary exploration" Meas. Sci. Tch., 2003, 14, 2159. [3] M. Tulej, A. Riedo, M.B. Neuland, S

  16. In-Situ Ion Analysis of Fresh Waters via an ISE Multiprobe and Artificial Neural Networks

    NASA Astrophysics Data System (ADS)

    Mueller, A. V.; Hemond, H.

    2010-12-01

    The ecological and geochemical sciences stand to substantially gain from capability for comprehensive, real-time, in-situ characterization of the chemical constituents of natural waters, e.g. by facilitating rapid high-resolution adaptive sampling campaigns and avoiding the potential errors and high costs related to traditional grab sample collection, transportation and in-lab analysis. In-situ chemical instrumentation also promotes the goals of large-scale monitoring networks, such as CUASHI and WATERS, by reducing the financial and human resources overhead required for traditional sampling at this scale. Problems of environmental remediation and monitoring of industrial waste waters would additionally benefit from such instrumental capacity. We have pursued in-situ measurement of all major ions contributing to the charge makeup (>99%) of oxic natural fresh waters via an instrument combining an array of ion-selective electrode (ISE) hardware with an appropriate multivariate signal processing architecture. Commercially available electrochemical sensors promote low cost and a fast development schedule, as well as easy maintenance and reproduction. Data processing techniques are adapted from artificial intelligence and chemometrics to extract accurate information from the corresponding in-situ data matrix. This architecture takes into account temperature, conductivity, and non-linearity effects, as well as taking advantage of sensor cross-selectivities traditionally considered as interferences. Chemical and mathematical constraints, e.g. charge balance and total ionic strength, provide further system-level information. Maximizing data recovery from the sensor array allows use of the instrument without the standard additions or ionic strength adjustment traditionally-required with use of ISEs. Initial work demonstrates the effectiveness of this methodology at predicting inorganic cations (sodium, potassium, calcium, and ammonium ) and hydrogen ion in a simplified

  17. Gas Hydrates on Mars: In-situ Resources for Human Habitation?

    NASA Astrophysics Data System (ADS)

    Max, M. D.; Pellenbarg, R. E.

    2002-05-01

    The apparent presence of abundant water on Mars, combined with the recent discovery of deep lithoautotrophic bacteria on Earth raises the possibility that a similar development of early life was established on Mars early in its history. CH4 would be a likely by-product of that deep biosphere metabolism. Where methane may have been produced over a long period of time, considerable volumes of it can be expected to have migrated toward the planet?s surface. Although confirmation of the presence of gas hydrate in the Martian subsurface has yet to be made, its occurrence is consistent with the temperature and pressure regimes expected at depth. The possible existence of substantial deposits of gas hydrates in the Martian subsurface, comparable to those now known on Earth, may be of critical importance to exploration and colonization of Mars because hydrate concentrates resources. Both CO2 and CH4 hydrates compress about 164 m3 of gas (at Earth STP) along with about 0.87m3 of pure water into each m3 of gas hydrate. The successful retrieval of concentrated CO2, CH4 and water from relatively shallow depths within the Martian cryosphere may provide the key of human occupation of Mars. In addition to the basic elements of fuel and water necessary to support the eventual expansion of human life across the surface of the planet virtually all shelter and hard goods can be fabricated from plastics produced from chemical components of these hydrate deposits.

  18. Portable Mass Spectrometer System for in-situ Environmental Gas Monitoring

    NASA Technical Reports Server (NTRS)

    Conejo, E.; Griffin, T. P.; Diaz, J. A.; Arkin, C. R.; Soto, C.; Naylor, G. R.; Curley, C.; Floyd, D.

    2005-01-01

    A system developed by NASA has been used for monitoring air quality around different locations. The system was designed for aircraft applications but has proven to be very useful as a portable gas analyzer. The system has been used to monitor air quality around volcanoes, cities, and the surrounding areas. The transport of the system has been via aircraft, car, and hand carried.

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

    USGS Publications Warehouse

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

    1983-01-01

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

  20. Gene numerical imbalances in cytological specimens based on fluorescence/chromogenic in situ hybridization analysis.

    PubMed

    Tsiambas, E; Karameris, A; Lygeros, M; Athanasiou, A E; Salemis, N S; Gourgiotis, S; Ragkos, V; Metaxas, G E; Vilaras, G; Patsouris, E

    2012-01-01

    Design and development of novel targeted therapeutic strategies is an innovation in handling patients with solid malignancies including breast, colon, lung, head & neck or even pancreatic and hepatocellular carcinoma. For a long time, immunohistocytochemistry (IHC/ICC) has been performed as a routine method in almost all labs for evaluating protein expression. Modern molecular approaches show that identification of specific structural and numerical imbalances regarding genes involved in signal transduction pathways provide important data to the oncologists. Alterations in molecules such as epidermal growth factor receptor (EGFR), HER2/neu, PTEN or Topoisomerase IIa affect the response rates to specific chemotherapeutic agents modifying also patients' prognostic rates. In situ hybridization (ISH) techniques based on fluorescence and chromogenic variants (FISH/CISH) or silver in situ hybridization (SISH) are applicable in both tissue and cell substrates. Concerning cytological specimens, FISH/CISH analysis appears to be a fast and very accurate method in estimating gene/chromosome ratios. In this paper, we sought to evaluate the usefulness of FISH/ CISH analysis in cytological specimens, describing also the advantages and disadvantages of these methods from the technical point of view. PMID:23033306

  1. Final Report: Sublinear Algorithms for In-situ and In-transit Data Analysis at Exascale.

    SciTech Connect

    Bennett, Janine Camille; Pinar, Ali; Seshadhri, C.; Thompson, David; Salloum, Maher; Bhagatwala, Ankit; Chen, Jacqueline H.

    2015-09-01

    Post-Moore's law scaling is creating a disruptive shift in simulation workflows, as saving the entirety of raw data to persistent storage becomes expensive. We are moving away from a post-process centric data analysis paradigm towards a concurrent analysis framework, in which raw simulation data is processed as it is computed. Algorithms must adapt to machines with extreme concurrency, low communication bandwidth, and high memory latency, while operating within the time constraints prescribed by the simulation. Furthermore, in- put parameters are often data dependent and cannot always be prescribed. The study of sublinear algorithms is a recent development in theoretical computer science and discrete mathematics that has significant potential to provide solutions for these challenges. The approaches of sublinear algorithms address the fundamental mathematical problem of understanding global features of a data set using limited resources. These theoretical ideas align with practical challenges of in-situ and in-transit computation where vast amounts of data must be processed under severe communication and memory constraints. This report details key advancements made in applying sublinear algorithms in-situ to identify features of interest and to enable adaptive workflows over the course of a three year LDRD. Prior to this LDRD, there was no precedent in applying sublinear techniques to large-scale, physics based simulations. This project has definitively demonstrated their efficacy at mitigating high performance computing challenges and highlighted the rich potential for follow-on re- search opportunities in this space.

  2. An integrated, subsurface characterization system for real-time, in-situ field analysis

    SciTech Connect

    Baumgart, C.W.; Creager, J.; Mathes, J.; Pounds, T.; VanDeusen, A.; Warthen, B.

    1996-02-01

    This paper describes current efforts at AlliedSignal Federal Manufacturing and Technologies (FM and T) to develop and field an in-situ, data analysis platform to acquire, process, and display site survey data in near real-time. In past years, FM and T has performed a number of site survey tasks. Each of these surveys was unique in application as well as in the type of data processing and analysis that was required to extract and visualize useful site characterization information. However, common to each of these surveys were the following specific computational and operational requirements: (1) a capability to acquire, process, and visualize the site survey data in the field; (2) a capability to perform all processing in a timely fashion (ideally real-time); and (3) a technique for correlating (or fusing) data streams from multiple sensors. Two more general, but no less important, requirements include system architecture modularity and positioning capability. Potential applications include: survey, evaluation, and remediation of numerous Department of Defense and Department of Energy waste sites; real-time detection and characterization of unexploded ordnance and landmines; survey, evaluation, and remediation of industrial waste sites; location of underground utility lines; and providing law enforcement agencies with real-time surveys of crime scenes. The paper describes an integrated data acquisition, processing, and visualization platform that is capable of performing in-situ data processing, interpretation, and visualization in real-time.

  3. Quartz Crystal Microbalance Technique for in Situ Analysis of Supersaturation in Cooling Crystallization.

    PubMed

    Liu, Li-Shang; Kim, Jong-Min; Kim, Woo-Sik

    2016-06-01

    A quartz crystal microbalance (QCM) is used as a novel in situ strategy for analyzing the supersaturation profile during cooling crystallization. The main concept is based on preventing any solid mass loading on the QCM sensor by modifying the sensor surface. As a result, the QCM responses only depend on the solution concentration changes during the crystallization. The proposed strategy is confirmed on the basis of an analysis of sulfamerazine (SMZ) crystallization. When the QCM sensor is modified using 11-amino-1-undecanethiol (AUT), crystal formation on the sensor is completely prevented due to a repulsive interaction between the -NH2 functional groups of the AUT and SMZ crystals. Thus, the QCM responses reflect only the property changes in the solution phase during the crystallization. The supersaturation in the solution is then estimated on the basis of the difference in the frequency shifts between the SMZ solution and a blank solution. The accuracy of the in situ QCM analysis of supersaturation is confirmed using an off-line gravimetric method. PMID:27161190

  4. Thermal decomposition of dolomite under CO2: insights from TGA and in situ XRD analysis.

    PubMed

    Valverde, Jose Manuel; Perejon, Antonio; Medina, Santiago; Perez-Maqueda, Luis A

    2015-11-28

    Thermal decomposition of dolomite in the presence of CO2 in a calcination environment is investigated by means of in situ X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The in situ XRD results suggest that dolomite decomposes directly at a temperature around 700 °C into MgO and CaO. Immediate carbonation of nascent CaO crystals leads to the formation of calcite as an intermediate product of decomposition. Subsequently, decarbonation of this poorly crystalline calcite occurs when the reaction is thermodynamically favorable and sufficiently fast at a temperature depending on the CO2 partial pressure in the calcination atmosphere. Decarbonation of this dolomitic calcite occurs at a lower temperature than limestone decarbonation due to the relatively low crystallinity of the former. Full decomposition of dolomite leads also to a relatively low crystalline CaO, which exhibits a high reactivity as compared to limestone derived CaO. Under CO2 capture conditions in the Calcium-Looping (CaL) process, MgO grains remain inert yet favor the carbonation reactivity of dolomitic CaO especially in the solid-state diffusion controlled phase. The fundamental mechanism that drives the crystallographic transformation of dolomite in the presence of CO2 is thus responsible for its fast calcination kinetics and the high carbonation reactivity of dolomitic CaO, which makes natural dolomite a potentially advantageous alternative to limestone for CO2 capture in the CaL technology as well as SO2in situ removal in oxy-combustion fluidized bed reactors. PMID:26506285

  5. Application of meta-transcriptomics and -proteomics to analysis of in situ physiological state

    PubMed Central

    Konopka, Allan; Wilkins, Michael J.

    2012-01-01

    Analysis of the growth-limiting factor or environmental stressors affecting microbes in situ is of fundamental importance but analytically difficult. Microbes can reduce in situ limiting nutrient concentrations to sub-micromolar levels, and contaminated ecosystems may contain multiple stressors. The patterns of gene or protein expression by microbes in nature can be used to infer growth limitations, because they are regulated in response to environmental conditions. Experimental studies under controlled conditions in the laboratory provide the physiological underpinnings for developing these physiological indicators. Although regulatory networks may differ among specific microbes, there are some broad principles that can be applied, related to limiting nutrient acquisition, resource allocation, and stress responses. As technologies for transcriptomics and proteomics mature, the capacity to apply these approaches to complex microbial communities will accelerate. Global proteomics has the particular advantage that it reflects expressed catalytic activities. Furthermore, the high mass accuracy of some proteomic approaches allows mapping back to specific microbial strains. For example, at the Rifle IFRC field site in Western Colorado, the physiological status of Fe(III)-reducing populations has been tracked over time. Members of a “subsurface clade” within the Geobacter predominated during carbon amendment to the subsurface environment. At the functional level, proteomic identifications produced inferences regarding (i) temporal changes in anabolism and catabolism of acetate, (ii) the onset of N2 fixation when N became limiting, and (iii) expression of phosphate transporters during periods of intense growth. The application of these approaches in situ can lead to discovery of novel physiological adaptations. PMID:22783237

  6. Thermal decomposition of dolomite under CO2: insights from TGA and in situ XRD analysis.

    PubMed

    Valverde, Jose Manuel; Perejon, Antonio; Medina, Santiago; Perez-Maqueda, Luis A

    2015-11-28

    Thermal decomposition of dolomite in the presence of CO2 in a calcination environment is investigated by means of in situ X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The in situ XRD results suggest that dolomite decomposes directly at a temperature around 700 °C into MgO and CaO. Immediate carbonation of nascent CaO crystals leads to the formation of calcite as an intermediate product of decomposition. Subsequently, decarbonation of this poorly crystalline calcite occurs when the reaction is thermodynamically favorable and sufficiently fast at a temperature depending on the CO2 partial pressure in the calcination atmosphere. Decarbonation of this dolomitic calcite occurs at a lower temperature than limestone decarbonation due to the relatively low crystallinity of the former. Full decomposition of dolomite leads also to a relatively low crystalline CaO, which exhibits a high reactivity as compared to limestone derived CaO. Under CO2 capture conditions in the Calcium-Looping (CaL) process, MgO grains remain inert yet favor the carbonation reactivity of dolomitic CaO especially in the solid-state diffusion controlled phase. The fundamental mechanism that drives the crystallographic transformation of dolomite in the presence of CO2 is thus responsible for its fast calcination kinetics and the high carbonation reactivity of dolomitic CaO, which makes natural dolomite a potentially advantageous alternative to limestone for CO2 capture in the CaL technology as well as SO2in situ removal in oxy-combustion fluidized bed reactors.

  7. Fluid Inclusion Gas Analysis

    DOE Data Explorer

    Dilley, Lorie

    2013-01-01

    Fluid inclusion gas analysis for wells in various geothermal areas. Analyses used in developing fluid inclusion stratigraphy for wells and defining fluids across the geothermal fields. Each sample has mass spectrum counts for 180 chemical species.

  8. In situ etching WO{sub 3} nanoplates: Hydrothermal synthesis, photoluminescence and gas sensor properties

    SciTech Connect

    Su, Xintai; Li, Yani; Jian, Jikang; Wang, Jide

    2010-12-15

    A novel hydrothermal process using p-nitrobenzoic acid as structure-directing agent has been employed to synthesize plate-shaped WO{sub 3} nanostructures containing holes. The p-nitrobenzoic acid plays a critical role in the synthesis of such novel WO{sub 3} nanoplates. The morphology, structure and optical property of the WO{sub 3} nanoplates have been characterized by transmission electron microcopy (TEM), scanning electron microcopy (SEM), X-ray diffraction (XRD) and photoluminescence (PL). The lateral size of the nanoplates is 500-1000 nm, and the thickness is about 80 nm. The formation mechanism of WO{sub 3} nanoplates is discussed briefly. The gas sensitivity of WO{sub 3} nanoplates was studied to ethanol and acetone at different operation temperatures and concentrations. Furthermore, the WO{sub 3} nanoplate-based gas sensor exhibits high sensitivity for ethanol and acetone as well as quick response and recovery time at low temperature.

  9. Confocal Raman microscopy and fluorescent in situ hybridization - A complementary approach for biofilm analysis.

    PubMed

    Kniggendorf, Ann-Kathrin; Nogueira, Regina; Kelb, Christian; Schadzek, Patrik; Meinhardt-Wollweber, Merve; Ngezahayo, Anaclet; Roth, Bernhard

    2016-10-01

    We combine confocal Raman microscopy (CRM) of wet samples with subsequent Fluorescent in situ hybridization (FISH) without significant limitations to either technique for analyzing the same sample of a microbial community on a cell-to-cell basis. This combination of techniques allows a much deeper, more complete understanding of complex environmental samples than provided by either technique alone. The minimalistic approach is based on laboratory glassware with micro-engravings for reproducible localization of the sample at cell scale combined with a fixation and de- and rehydration protocol for the respective techniques. As proof of concept, we analyzed a floc of nitrifying activated sludge, demonstrating that the sample can be tracked with cell-scale precision over different measurements and instruments. The collected information includes the microbial content, spatial shape, variant chemical compositions of the floc matrix and the mineral microparticles embedded within. In addition, the direct comparison of CRM and FISH revealed a difference in reported cell size due to the different cell components targeted by the respective technique. To the best of our knowledge, this is the first report of a direct cell-to-cell comparison of confocal Raman microscopy and Fluorescent in situ hybridization analysis performed on the same sample. An adaptation of the method to include native samples as a starting point is planned for the near future. The micro-engraving approach itself also opens up the possibility of combining other, functionally incompatible techniques as required for further in-depth investigations of low-volume samples. PMID:27423128

  10. Improving the Molecular Ion Signal Intensity for In Situ Liquid SIMS Analysis

    NASA Astrophysics Data System (ADS)

    Zhou, Yufan; Yao, Juan; Ding, Yuanzhao; Yu, Jiachao; Hua, Xin; Evans, James E.; Yu, Xiaofei; Lao, David B.; Heldebrant, David J.; Nune, Satish K.; Cao, Bin; Bowden, Mark E.; Yu, Xiao-Ying; Wang, Xue-Lin; Zhu, Zihua

    2016-09-01

    In situ liquid secondary ion mass spectrometry (SIMS) enabled by system for analysis at the liquid vacuum interface (SALVI) has proven to be a promising new tool to provide molecular information at solid-liquid and liquid-vacuum interfaces. However, the initial data showed that useful signals in positive ion spectra are too weak to be meaningful in most cases. In addition, it is difficult to obtain strong negative molecular ion signals when m/z>200. These two drawbacks have been the biggest obstacle towards practical use of this new analytical approach. In this study, we report that strong and reliable positive and negative molecular signals are achievable after optimizing the SIMS experimental conditions. Four model systems, including a 1,8-diazabicycloundec-7-ene (DBU)-base switchable ionic liquid, a live Shewanella oneidensis biofilm, a hydrated mammalian epithelia cell, and an electrolyte popularly used in Li ion batteries were studied. A signal enhancement of about two orders of magnitude was obtained in comparison with non-optimized conditions. Therefore, molecular ion signal intensity has become very acceptable for use of in situ liquid SIMS to study solid-liquid and liquid-vacuum interfaces.

  11. Quantitative analysis of in situ hybridization methods for the detection of actin gene expression.

    PubMed Central

    Lawrence, J B; Singer, R H

    1985-01-01

    We have implemented an efficient, quantitative approach for the optimization of in situ hybridization using double-stranded recombinant DNA probes. The model system studied was actin mRNA expression in chicken embryonic muscle cultures. Actin and control (pBR322) probes were nick-translated with p32 labeled nucleotides, hybridized to cells grown on coverslips, and quantitated in a scintillation counter. Cellular RNA retention was monitored via the incorporation of H3-Uridine into RNA prior to cell fixation. Over a thousand samples were analyzed, and among the technical variables examined were the fixation protocol, proteolytic cell pretreatment, the time course of hybridization, saturation kinetics, hybridization efficiency, and effect of probe size on hybridization and network formation. Results have allowed us to develop a reproducible in situ hybridization methodology which is simpler and less destructive to cellular RNA and morphology than other protocols. Moreover, this technique is highly sensitive and efficient in detection of cellular RNAs. Lastly, the rapid quantitative approach used for this analysis is valuable in itself as a potential alternative to filter or solution hybridizations. Images PMID:3889842

  12. An Asynchronous Many-Task Implementation of In-Situ Statistical Analysis using Legion.

    SciTech Connect

    Pebay, Philippe Pierre; Bennett, Janine Camille

    2015-11-01

    In this report, we propose a framework for the design and implementation of in-situ analy- ses using an asynchronous many-task (AMT) model, using the Legion programming model together with the MiniAero mini-application as a surrogate for full-scale parallel scientific computing applications. The bulk of this work consists of converting the Learn/Derive/Assess model which we had initially developed for parallel statistical analysis using MPI [PTBM11], from a SPMD to an AMT model. In this goal, we propose an original use of the concept of Legion logical regions as a replacement for the parallel communication schemes used for the only operation of the statistics engines that require explicit communication. We then evaluate this proposed scheme in a shared memory environment, using the Legion port of MiniAero as a proxy for a full-scale scientific application, as a means to provide input data sets of variable size for the in-situ statistical analyses in an AMT context. We demonstrate in particular that the approach has merit, and warrants further investigation, in collaboration with ongoing efforts to improve the overall parallel performance of the Legion system.

  13. Steady-state analysis of the fate of volatile contaminants during In situ Vitrification

    SciTech Connect

    Kuhn, W.L.

    1992-05-01

    A mathematical simulation has been developed to describe the transport of water, steam, and trace concentrations of volatile contaminants in soil during the application of the In Situ Vitrification (ISV) process. The ISV process creates a mass of molten soil that grows during processing. Testing has shown that the vast majority of water encountered and vaporized by the growing melt is expelled from the soil and directed to an off-gas treatment system. The simulation addresses the question: under what conditions will other volatile species also be expelled from the soil and be directed to the off-gas system (or oxidized or pyrolyzed in transit) The simulation is based on an assumed spherical symmetry of temperature, liquid saturation, and contaminant concentration profiles adjacent to an assumed expanding hemispherical melt. A set of coupled, nonlinear ordinary differential equations are solved numerically to predict the transport of water and steam in two regions: a boiling region (essentially a heat pipe) assumed to be devoid of air, and a diffusion region assumed to be at constant pressure. The results of the simulation are presented in terms of the degree of sorption in soil required to predict that the contaminant is captured by the growing ISV melt. Results are presented for carbon tetrachloride, benzene, and acetone. The results are very favorable for acetone; success in capturing immiscible species such as carbon tetrachloride depend on the organic content of the soil, which affects sorption of organic species.

  14. Steady-state analysis of the fate of volatile contaminants during In situ Vitrification

    SciTech Connect

    Kuhn, W.L.

    1992-05-01

    A mathematical simulation has been developed to describe the transport of water, steam, and trace concentrations of volatile contaminants in soil during the application of the In Situ Vitrification (ISV) process. The ISV process creates a mass of molten soil that grows during processing. Testing has shown that the vast majority of water encountered and vaporized by the growing melt is expelled from the soil and directed to an off-gas treatment system. The simulation addresses the question: under what conditions will other volatile species also be expelled from the soil and be directed to the off-gas system (or oxidized or pyrolyzed in transit)? The simulation is based on an assumed spherical symmetry of temperature, liquid saturation, and contaminant concentration profiles adjacent to an assumed expanding hemispherical melt. A set of coupled, nonlinear ordinary differential equations are solved numerically to predict the transport of water and steam in two regions: a boiling region (essentially a heat pipe) assumed to be devoid of air, and a diffusion region assumed to be at constant pressure. The results of the simulation are presented in terms of the degree of sorption in soil required to predict that the contaminant is captured by the growing ISV melt. Results are presented for carbon tetrachloride, benzene, and acetone. The results are very favorable for acetone; success in capturing immiscible species such as carbon tetrachloride depend on the organic content of the soil, which affects sorption of organic species.

  15. In situ analysis of ion-induced polymer surface modification using secondary ion mass spectroscopy

    NASA Astrophysics Data System (ADS)

    Okuji, Shigeto; Kitazawa, Hideaki; Takeda, Yoshihiko

    2016-06-01

    We have investigated the surface modification process consisting of ion irradiation immediately followed by exposure to ambient gas for three types of polymers having the same main chain, sbnd Csbnd Csbnd , but different atoms bound to the main chain, using in situ secondary ion mass spectroscopy. The polymers' surface was irradiated with 30 keV Au ions at a total fluence for up to 1 × 1017 cm-2 and exposed to ambient gas in a ultra-high-vacuum chamber (1 × 10-6 Pa) for 30 min after the ion irradiation. Low density polyethylene mainly exhibited a hydrogen dissociation during the ion irradiation and a recombination with hydrogen atoms by the exposure, polytetrafluoroethylene mainly showed a main chain scission and no recombination during the exposure, and polyvinylidene difluoride lost hydrogen and fluorine atoms by the ion irradiation and partially recombined with hydrogen and fluorine atoms upon the exposure. The deposited energy density on the polymer surfaces reflects the dependence of the modification on the incident ion species, Au or Ga ions.

  16. In situ O2 dynamics in submerged Isoetes australis: varied leaf gas permeability influences underwater photosynthesis and internal O2.

    PubMed

    Pedersen, Ole; Pulido, Cristina; Rich, Sarah Meghan; Colmer, Timothy David

    2011-08-01

    A unique type of vernal pool are those formed on granite outcrops, as the substrate prevents percolation so that water accumulates in depressions when precipitation exceeds evaporation. The O(2) dynamics of small, shallow vernal pools with dense populations of Isoetes australis were studied in situ, and the potential importance of the achlorophyllous leaf bases to underwater net photosynthesis (P(N)) and radial O(2) loss to sediments is highlighted. O(2) microelectrodes were used in situ to monitor pO(2) in leaves, shallow sediments, and water in four vernal pools. The role of the achlorophyllous leaf bases in gas exchange was evaluated in laboratory studies of underwater P(N), loss of tissue water, radial O(2) loss, and light microscopy. Tissue and sediment pO(2) showed large diurnal amplitudes and internal O(2) was more similar to sediment pO(2) than water pO(2). In early afternoon, sediment pO(2) was often higher than tissue pO(2) and although sediment O(2) declined substantially during the night, it did not become anoxic. The achlorophyllous leaf bases were 34% of the surface area of the shoots, and enhanced by 2.5-fold rates of underwater P(N) by the green portions, presumably by increasing the surface area for CO(2) entry. In addition, these leaf bases would contribute to loss of O(2) to the surrounding sediments. Numerous species of isoetids, seagrasses, and rosette-forming wetland plants have a large proportion of the leaf buried in sediments and this study indicates that the white achlorophyllous leaf bases may act as an important area of entry for CO(2), or exit for O(2), with the surrounding sediment.

  17. First in-situ sensing of volcanic gas plume composition at Boiling Lake (Dominica, West Indies)

    NASA Astrophysics Data System (ADS)

    Di Napoli, R.; Aiuppa, A.; Allard, P.

    2012-12-01

    Dominica, a small Caribbean island between Martinique (to the South) and Guadeloupe (to the North), is, because of the high number of potentially active volcanic centres, one of the most susceptible sites to volcanic risk in the Lesser Antilles arc. Seven major volcanic centres, active during the last 10ka, are considered likely to erupt again, and one of these is the Valley of Desolation volcanic complex. This is an area of 0.5 km2, located in on SW Dominica, where a number of small explosion craters, hot springs, bubbling pools and fumaroles testify for vigorous and persistent hydrothermal activity. Two main phreatic explosions have been documented in historical time (1880 and 1997), and the most likely centre of future activity is the Boiling Lake, a nearby high-T volcanic crater lake produced by an undated phreatic/phreato-magmatic explosion. Hot (80 to 90°C) and acidic (4-6) waters normally characterize the steady-state activity of the lake, whereby which vigorous gas upwelling in the lake's centre feeds a persistent steaming plume. Stability of the Boiling Lake has occasionally been interrupted in the past (since 1876) by crises, the most recent in 2004, involving rapid draining of the lake and changes in water temperature and pH, likely as a result of drastic decrease of hydrothermal fluid input into the lake. While the chemical and isotopic composition of the lake waters is well characterised, there are no compositional data available for the gas plume leaving the lake, due to inherent difficulties in direct gas sampling. Here, we present the results of the first direct measurements of the Boiling Lake's plume, performed by using the MultiGAS technique in February 2012. We acquired 0.5 Hz time-series of H2O, CO2, H2S and SO2 plume concentrations, which were seen to peak (with maximum background-corrected concentrations of 3680, 101 and 25 ppm for respectively H2O, CO2 and H2S) during phases of visible increase in lake outgassing. SO2 was virtually absent

  18. Challenges and solutions for the analysis of in situ, in crystallo micro-spectrophotometric data

    PubMed Central

    Dworkowski, Florian S. N.; Hough, Michael A.; Pompidor, Guillaume; Fuchs, Martin R.

    2015-01-01

    Combining macromolecular crystallography with in crystallo micro-spectrophotometry yields valuable complementary information on the sample, including the redox states of metal cofactors, the identification of bound ligands and the onset and strength of undesired photochemistry, also known as radiation damage. However, the analysis and processing of the resulting data differs significantly from the approaches used for solution spectrophotometric data. The varying size and shape of the sample, together with the suboptimal sample environment, the lack of proper reference signals and the general influence of the X-ray beam on the sample have to be considered and carefully corrected for. In the present article, how to characterize and treat these sample-dependent artefacts in a reproducible manner is discussed and the SLS-APE in situ, in crystallo optical spectroscopy data-analysis toolbox is demonstrated. PMID:25615857

  19. Challenges and solutions for the analysis of in situ , in crystallo micro-spectrophotometric data

    DOE PAGES

    Dworkowski, Florian S. N.; Hough, Michael A.; Pompidor, Guillaume; Fuchs, Martin R.

    2015-01-01

    Combining macromolecular crystallography with in crystallo micro-spectrophotometry yields valuable complementary information on the sample, including the redox states of metal cofactors, the identification of bound ligands and the onset and strength of undesired photochemistry, also known as radiation damage. However, the analysis and processing of the resulting data differs significantly from the approaches used for solution spectrophotometric data. The varying size and shape of the sample, together with the suboptimal sample environment, the lack of proper reference signals and the general influence of the X-ray beam on the sample have to be considered and carefully corrected for. In the presentmore » article, we discuss how to characterize and treat these sample-dependent artefacts in a reproducible manner and we demonstrate the SLS-APE in situ, in crystallo optical spectroscopy data-analysis toolbox.« less

  20. In Situ Analysis of Orthopyroxene in Diogenites Using Laser Ablation ICP-MS

    NASA Technical Reports Server (NTRS)

    Elk, Mattias; Quinn, J. E.; Mittlefehldt, D. W.

    2012-01-01

    Howardites, eucrites and diogenites (HED) form a suit of igneous achondrite meteorites that are thought to have formed on a single asteroidal body. While there have been many different models proposed for the formation of the HED parent asteroid they can be generalized into two end member models. One is the magma ocean model (e.g. [1]) in which the entire HED parent body was continuously fractionated from a planet wide magma ocean with diogenites representing the lower crust and eucrites being upper crustal rocks. The second model hypothesizes that diogenites and eucrites were formed as a series of intrusions and/or extrusions of partial melts of a primitive proto-Vesta [2]. We use in situ trace element analysis together with major and minor element analysis to try and distinguish between these different hypotheses for the evolution of the HED parent body.

  1. In situ immunogold labeling analysis of the rice hoja blanca virus nucleoprotein and major noncapsid protein.

    PubMed

    Espinoza, A M; Hernández, M; Pereira, R; Falk, B; Medina, V

    1992-12-01

    Ribonucleoprotein particles (RNPs) of rice hoja blanca virus (RHBV) were purified and used for electron microscopic analysis and antibody production. Antibodies made to RNPs specifically decorated purified RNPs. The RNPs typically showed characteristic tenuivirus morphologies. They were approximately 8 nm in diameter, mostly circular in nature, and exhibited branching and a high degree of superhelicity. When the RNP antibodies were used for in situ immunogold labeling analysis of RHBV-infected tissues, no specific structures were identified, but gold particles were distributed throughout the cytosol of RHBV-infected but not healthy plants. However, amorphous semi-electron opaque inclusion bodies (ASO-IBs) were abundant in cells of RHBV-infected plants. While the ASO-IBs were not labeled with the anti-RNP antiserum, they were specifically labeled with antibodies to the RHBV major noncapsid protein (NCP) and with antibodies to the NCP of another tenuivirus, maize stripe virus. PMID:1448918

  2. Converting oil shale to liquid fuels: energy inputs and greenhouse gas emissions of the Shell in situ conversion process.

    PubMed

    Brandt, Adam R

    2008-10-01

    Oil shale is a sedimentary rock that contains kerogen, a fossil organic material. Kerogen can be heated to produce oil and gas (retorted). This has traditionally been a CO2-intensive process. In this paper, the Shell in situ conversion process (ICP), which is a novel method of retorting oil shale in place, is analyzed. The ICP utilizes electricity to heat the underground shale over a period of 2 years. Hydrocarbons are produced using conventional oil production techniques, leaving shale oil coke within the formation. The energy inputs and outputs from the ICP, as applied to oil shales of the Green River formation, are modeled. Using these energy inputs, the greenhouse gas (GHG) emissions from the ICP are calculated and are compared to emissions from conventional petroleum. Energy outputs (as refined liquid fuel) are 1.2-1.6 times greater than the total primary energy inputs to the process. In the absence of capturing CO2 generated from electricity produced to fuel the process, well-to-pump GHG emissions are in the range of 30.6-37.1 grams of carbon equivalent per megajoule of liquid fuel produced. These full-fuel-cycle emissions are 21%-47% larger than those from conventionally produced petroleum-based fuels.

  3. Sensitive in situ trace-gas detection by photothermal deflection spectroscopy

    SciTech Connect

    Fournier, D.; Boccara, A. C.; Amer, Nabil M.; Gerlach, Robert

    1980-03-01

    We present a sensitive (5ppb for ethylene, 10-7 cm-1) and simple photothermal scheme for the detection of trace gases and measuring weak absorption in gas-phase samples. We also demonstrate the feasibility of this scheme for performing i n s i t u measurements in the absence of sample cells or containers, thus eliminating the drawbacks of sampling and sampling techniques. Finally, factors limiting our detectivity are discussed, and a comparison to the thermal lens effect is made.

  4. A method for measuring the local gas pressure within a gas-flow stage in situ in the transmission electron microscope

    SciTech Connect

    Colby, Robert J.; Alsem, Daan H.; Liyu, Andrey V.; Kabius, Bernd C.

    2015-06-01

    The development of environmental transmission electron microscopy (TEM) has enabled in situ experiments in a gaseous environment with high resolution imaging and spectroscopy. Addressing scientific challenges in areas such as catalysis, corrosion, and geochemistry can require pressures much higher than the ~20 mbar achievable with a differentially pumped, dedicated environmental TEM. Gas flow stages, in which the environment is contained between two semi-transparent thin membrane windows, have been demonstrated at pressures of several atmospheres. While this constitutes significant progress towards operando measurements, the design of many current gas flow stages is such that the pressure at the sample cannot necessarily be directly inferred from the pressure differential across the system. Small differences in the setup and design of the gas flow stage can lead to very different sample pressures. We demonstrate a method for measuring the gas pressure directly, using a combination of electron energy loss spectroscopy and TEM imaging. This method requires only two energy filtered TEM images, limiting the measurement time to a few seconds and can be performed during an ongoing experiment at the region of interest. This approach provides a means to ensure reproducibility between different experiments, and even between very differently designed gas flow stages.

  5. A method for measuring the local gas pressure within a gas-flow stage in situ in the transmission electron microscope.

    PubMed

    Colby, R; Alsem, D H; Liyu, A; Kabius, B

    2015-06-01

    Environmental transmission electron microscopy (TEM) has enabled in situ experiments in a gaseous environment with high resolution imaging and spectroscopy. Addressing scientific challenges in areas such as catalysis, corrosion, and geochemistry can require pressures much higher than the ∼20 mbar achievable with a differentially pumped environmental TEM. Gas flow stages, in which the environment is contained between two semi-transparent thin membrane windows, have been demonstrated at pressures of several atmospheres. However, the relationship between the pressure at the sample and the pressure drop across the system is not clear for some geometries. We demonstrate a method for measuring the gas pressure at the sample by measuring the ratio of elastic to inelastic scattering and the defocus of the pair of thin windows. This method requires two energy filtered high-resolution TEM images that can be performed during an ongoing experiment, at the region of interest. The approach is demonstrated to measure greater than atmosphere pressures of N2 gas using a commercially available gas-flow stage. This technique provides a means to ensure reproducible sample pressures between different experiments, and even between very differently designed gas-flow stages. PMID:25765435

  6. In situ growth of carbon nanotubes on Ni/MgO: a facile preparation of efficient catalysts for the production of synthetic natural gas from syngas.

    PubMed

    Fan, M T; Lin, J D; Zhang, H B; Liao, D W

    2015-11-01

    Ni/MgO-CNTs catalysts are prepared by in situ chemical vapor deposition growth of CNTs on Ni/MgO. These catalysts exhibit an improved performance for the production of synthetic natural gas from syngas, which is attributed to the formation of highly catalytic active interfaces among Ni, CNTs and MgO.

  7. In situ growth of carbon nanotubes on Ni/MgO: a facile preparation of efficient catalysts for the production of synthetic natural gas from syngas.

    PubMed

    Fan, M T; Lin, J D; Zhang, H B; Liao, D W

    2015-11-01

    Ni/MgO-CNTs catalysts are prepared by in situ chemical vapor deposition growth of CNTs on Ni/MgO. These catalysts exhibit an improved performance for the production of synthetic natural gas from syngas, which is attributed to the formation of highly catalytic active interfaces among Ni, CNTs and MgO. PMID:26365211

  8. In situ polymerization deposition of porous conducting polymer on reduced graphene oxide for gas sensor.

    PubMed

    Yang, Yajie; Li, Shibin; Yang, Wenyao; Yuan, Wentao; Xu, Jianhua; Jiang, Yadong

    2014-08-27

    Porous conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) nanocomposite prepared on reduced graphene oxide (RGO) film was used as efficient chemiresistor sensor platform for NO2 detection. The comparable electrical performance between RGO and porous PEDOT nanostructure, the large surface area and opening porous structure of this RGO/porous PEDOT nanocomposite resulted in excellent synergistic effect. The gas sensing performance revealed that, in contrast to bare RGO, the RGO/porous PEDOT exhibited the enhanced sensitivity (2 orders of magnitude) as well as response and recovery performance. As a result of the highly uniform distribution of PEDOT porous network and excellent synergetic effect between RGO and porous PEDOT, this nanocomposite based sensor exhibited higher selectivity to NO2 in contrast to other oxidant analyte gases, e.g., HCl, H2S and SO2. PMID:25073562

  9. A bracket approach to improve the stability and gas sorption performance of a metal-organic framework via in situ incorporating the size-matching molecular building blocks.

    PubMed

    Chen, Di-Ming; Tian, Jia-Yue; Liu, Chun-Sen; Du, Miao

    2016-06-28

    Incorporating the in situ formed size-matching molecular building blocks (MBBs) into the open channels will remarkably improve the robustness and gas sorption performance of an evacuated metal-organic framework. As a result, such MBBs can transfer the open metal sites from the framework walls to the channel centers and separate the large channels into multiple smaller voids, leading to a molecular sieving effect and high-performance gas-separation of the modified material. PMID:27301546

  10. Gas hydrate formation in the deep sea: In situ experiments with controlled release of methane, natural gas, and carbon dioxide

    USGS Publications Warehouse

    Brewer, P.G.; Orr, F.M.; Friederich, G.; Kvenvolden, K.A.; Orange, D.L.

    1998-01-01

    We have utilized a remotely operated vehicle (ROV) to initiate a program of research into gas hydrate formation in the deep sea by controlled release of hydrocarbon gases and liquid CO2 into natural sea water and marine sediments. Our objectives were to investigate the formation rates and growth patterns of gas hydrates in natural systems and to assess the geochemical stability of the reaction products over time. The novel experimental procedures used the carrying capacity, imaging capability, and control mechanisms of the ROV to transport gas cylinders to depth and to open valves selectively under desired P-T conditions to release the gas either into contained natural sea water or into sediments. In experiments in Monterey Bay, California, at 910 m depth and 3.9??C water temperature we find hydrate formation to be nearly instantaneous for a variety of gases. In sediments the pattern of hydrate formation is dependent on the pore size, with flooding of the pore spaces in a coarse sand yielding a hydrate cemented mass, and gas channeling in a fine-grained mud creating a veined hydrate structure. In experiments with liquid CO2 the released globules appeared to form a hydrate skin as they slowly rose in the apparatus. An initial attempt to leave the experimental material on the sea floor for an extended period was partially successful; we observed an apparent complete dissolution of the liquid CO2 mass, and an apparent consolidation of the CH4 hydrate, over a period of about 85 days.

  11. POWTEX Neutron Diffractometer at FRM II - New Perspectives for In-Situ Rock Deformation Analysis

    NASA Astrophysics Data System (ADS)

    Walter, J. M.; Stipp, M.; Ullemeyer, K.; Klein, H.; Leiss, B.; Hansen, B. T.; Kuhs, W. F.

    2012-04-01

    In Geoscience quantitative texture analysis here defined as the quantitative analysis of the crystallographic preferred orientation (CPO), is a common tool for the investigation of fabric development in mono- and polyphase rocks, their deformation histories and kinematics. Bulk texture measurements also allow the quantitative characterisation of the anisotropic physical properties of rock materials. A routine tool to measure bulk sample volumes is neutron texture diffraction, as neutrons have large penetration capabilities of several cm in geological sample materials. The new POWTEX (POWder and TEXture) Diffractometer at the neutron research reactor FRM II in Garching, Germany is designed as a high-intensity diffractometer by groups from the RWTH Aachen, Forschungszentrum Jülich and the University of Göttingen. Complementary to existing neutron diffractometers (SKAT at Dubna, Russia; GEM at ISIS, UK; HIPPO at Los Alamos, USA; D20 at ILL, France; and the local STRESS-SPEC and SPODI at FRM II) the layout of POWTEX is focused on fast time-resolved experiments and the measurement of larger sample series as necessary for the study of large scale geological structures. POWTEX is a dedicated beam line for geoscientific research. Effective texture measurements without sample tilting and rotation are possible firstly by utilizing a range of neutron wavelengths simultaneously (Time-of-Flight technique) and secondly by the high detector coverage (9.8 sr) and a high flux (~1 - 107 n/cm2s) at the sample. Furthermore the instrument and the angular detector resolution is designed also for strong recrystallisation textures as well as for weak textures of polyphase rocks. These instrument characteristics allow in-situ time-resolved texture measurements during deformation experiments on rocksalt, ice and other materials as large sample environments will be implemented at POWTEX. The in-situ deformation apparatus is operated by a uniaxial spindle drive with a maximum axial load of

  12. Complex organic matter in Titan's atmospheric aerosols from in situ pyrolysis and analysis.

    PubMed

    Israël, G; Szopa, C; Raulin, F; Cabane, M; Niemann, H B; Atreya, S K; Bauer, S J; Brun, J-F; Chassefière, E; Coll, P; Condé, E; Coscia, D; Hauchecorne, A; Millian, P; Nguyen, M-J; Owen, T; Riedler, W; Samuelson, R E; Siguier, J-M; Steller, M; Sternberg, R; Vidal-Madjar, C

    2005-12-01

    Aerosols in Titan's atmosphere play an important role in determining its thermal structure. They also serve as sinks for organic vapours and can act as condensation nuclei for the formation of clouds, where the condensation efficiency will depend on the chemical composition of the aerosols. So far, however, no direct information has been available on the chemical composition of these particles. Here we report an in situ chemical analysis of Titan's aerosols by pyrolysis at 600 degrees C. Ammonia (NH3) and hydrogen cyanide (HCN) have been identified as the main pyrolysis products. This clearly shows that the aerosol particles include a solid organic refractory core. NH3 and HCN are gaseous chemical fingerprints of the complex organics that constitute this core, and their presence demonstrates that carbon and nitrogen are in the aerosols.

  13. In situ analysis of adsorption process from residual gases during thin film deposition

    NASA Astrophysics Data System (ADS)

    Giedraitis, A.; Tamulevicius, S.; Slapikas, K.; Gudaitis, R.; Juraitis, A.

    2008-03-01

    In this work we present the developed experimental technique as well as results of optical control of adsorption processes during thin film deposition. Different metallic films: (silver) as a model material and barium getter films were studied. Thermal evaporation method has been used to deposit thin metallic films and films of barium getter on glass substrates. Kinetics of the optical absorbance of the growing film was registered in situ measuring transmission of the film-substrate structure. These measurements were done in parallel to the ex-situ absorption (UV-VIS) and reflection spectra as well as XRD analysis. Such complex measurements enabled us to follow adsorption process from the residual gases during thermal evaporation as well to control adsorption process after the evaporation.

  14. In situ tooth replica custom implant: a 3-dimensional finite element stress and strain analysis.

    PubMed

    Ghuneim, Wael Aly

    2013-10-01

    This study is a phase of a biomechanical study, a part of a research program concerned with the new concept of in situ tooth replication. The purpose of the study was to evaluate tooth replica under each of two possible circumstances: (1) attachment via periodontal ligament and (2) osseointegration. Replicas were made of Cortoss, a bioactive glass, bone substitute. Three-dimensional finite element analysis was used to assess the stresses and strains resulting from each of 2 types of loads: off-vertical pressure and vertical point force acting on natural mandibular second premolar and corresponding replicas. Natural tooth tolerated 19 MPa pressure or 85 N vertical force, periodontally attached replica tolerated 15 MPa pressure or 80 N force, and osseointegrated replica tolerated 23 MPa pressure or 217 N force.

  15. Advanced In-Situ Detection and Chemical Analysis of Interstellar Dust Particles

    NASA Astrophysics Data System (ADS)

    Sternovsky, Z.; Gemer, A.; Gruen, E.; Horanyi, M.; Kempf, S.; Maute, K.; Postberg, F.; Srama, R.; Williams, E.; O'brien, L.; Rocha, J. R. R.

    2015-12-01

    The Ulysses dust detector discovered that interstellar dust particles pass through the solar system. The Hyperdsut instrument is developed for the in-situ detection and analysis of these particles to determine the elemental, chemical and isotopic compositions. Hyperdust builds on the heritage of previous successful instruments, e.g. the Cosmic Dust Analyzer (CDA) on Cassini. Hyperdust combines a highly sensitive Dust Trajectory Sensor (DTS) and the high mass resolution Chemical Analyzer (CA). The DTS will detect dust particles as small as 0.3 μm in radius, and the velocity vector information is used to confirm the interstellar origin and/or reveal the dynamics from the interactions within the solar system. The effective target area of the CA is > 600 cm2 achieves mass resolution in excess of 200, which is considerably higher than that of CDA, and is acheved by advanced ion optics design. The Hyperdust instrument is in the final phases of development to TRL 6.

  16. Complex organic matter in Titan's atmospheric aerosols from in situ pyrolysis and analysis.

    PubMed

    Israël, G; Szopa, C; Raulin, F; Cabane, M; Niemann, H B; Atreya, S K; Bauer, S J; Brun, J-F; Chassefière, E; Coll, P; Condé, E; Coscia, D; Hauchecorne, A; Millian, P; Nguyen, M-J; Owen, T; Riedler, W; Samuelson, R E; Siguier, J-M; Steller, M; Sternberg, R; Vidal-Madjar, C

    2005-12-01

    Aerosols in Titan's atmosphere play an important role in determining its thermal structure. They also serve as sinks for organic vapours and can act as condensation nuclei for the formation of clouds, where the condensation efficiency will depend on the chemical composition of the aerosols. So far, however, no direct information has been available on the chemical composition of these particles. Here we report an in situ chemical analysis of Titan's aerosols by pyrolysis at 600 degrees C. Ammonia (NH3) and hydrogen cyanide (HCN) have been identified as the main pyrolysis products. This clearly shows that the aerosol particles include a solid organic refractory core. NH3 and HCN are gaseous chemical fingerprints of the complex organics that constitute this core, and their presence demonstrates that carbon and nitrogen are in the aerosols. PMID:16319825

  17. A prototype mass spectrometer for in situ analysis of cave atmospheres

    NASA Astrophysics Data System (ADS)

    Patrick, Edward L.; Mandt, Kathleen E.; Mitchell, Evelynn J.; Mitchell, Joseph N.; Younkin, Kerri N.; Seifert, Clarissa M.; Williams, Gregg C.

    2012-10-01

    Research in cave environments has many applications: studying local hydrogeologic activity, paleoclimate studies, analyzing white nose syndrome in bat populations, analogs for underground atmospheres in mining facilities, carbon sequestration efforts, and terrestrial analogs for planetary caves. The atmospheres of many caves contain tracers of current geological and biological activity, but up to this point, in situ studies have been limited to sensors that monitor individual components of the cave atmosphere. A prototype cave mass spectrometer system was assembled from commercial off-the-shelf parts to conduct surveys of atmospheric compositions inside four local Texas caves and to perform atmospheric analysis of two aquifer wellheads to a depth of 60 m. We found increased levels of CO2 in all caves and, surprisingly, increased levels of O2 in Bracken Bat Cave. Aquifer wellhead measurements showed indications of methane, other hydrocarbons, and other constituents not anticipated.

  18. Granulometry and Moisture Influence for In Situ Soil Analysis by Portable EDXRF

    NASA Astrophysics Data System (ADS)

    Melquiades, Fábio L.; Bastos, Rodrigo O.; Biasi, Gabriel E. V.; Parreira, Paulo S.; Appoloni, Carlos R.

    2011-08-01

    The objective of this work was to verify the granulometry and the moisture influence in results when soils samples are measured for identification and quantification of metal, on field, employing portable Energy Dispersive X-Ray Fluorescence (PXRF) equipment. For granulometry, the obtained concentration values for Ti, Fe and Zr, are equivalent for the samples grinded for one minute and the samples grinded and sieved. This result indicates that, for in situ analysis of this soil, it is sufficient to grind the dried sample before measurement. For moisture, concentration values obtained for the samples dried from 30 to 120 minutes at sun are equivalent. On the other hand, the concentration values obtained for the samples dried during 24 h are higher than the values obtained for the same samples dried at sun. Moisture influences the concentrations values in around 20%.

  19. In situ detection of small-size insect pests sampled on traps using multifractal analysis

    NASA Astrophysics Data System (ADS)

    Xia, Chunlei; Lee, Jang-Myung; Li, Yan; Chung, Bu-Keun; Chon, Tae-Soo

    2012-02-01

    We introduce a multifractal analysis for detecting the small-size pest (e.g., whitefly) images from a sticky trap in situ. An automatic attraction system is utilized for collecting pests from greenhouse plants. We applied multifractal analysis to segment action of whitefly images based on the local singularity and global image characteristics. According to the theory of multifractal dimension, the candidate blobs of whiteflies are initially defined from the sticky-trap image. Two schemes, fixed thresholding and regional minima obtainment, were utilized for feature extraction of candidate whitefly image areas. The experiment was conducted with the field images in a greenhouse. Detection results were compared with other adaptive segmentation algorithms. Values of F measuring precision and recall score were higher for the proposed multifractal analysis (96.5%) compared with conventional methods such as Watershed (92.2%) and Otsu (73.1%). The true positive rate of multifractal analysis was 94.3% and the false positive rate minimal level at 1.3%. Detection performance was further tested via human observation. The degree of scattering between manual and automatic counting was remarkably higher with multifractal analysis (R2=0.992) compared with Watershed (R2=0.895) and Otsu (R2=0.353), ensuring overall detection of the small-size pests is most feasible with multifractal analysis in field conditions.

  20. Technical Note: In-situ derivatization thermal desorption GC-TOFMS for direct analysis of particle-bound non-polar and polar organic species

    NASA Astrophysics Data System (ADS)

    Orasche, J.; Schnelle-Kreis, J.; Abbaszade, G.; Zimmermann, R.

    2011-05-01

    An in-situ derivatization thermal desorption method followed by gas chromatography and time-of-flight mass spectrometry (IDTD-GC-TOFMS) was developed for determination of polar organic compounds. Hydroxyl and carboxyl groups of compounds such as anhydrous sugars, alcohols and phenols, fatty acids and resin acids are targets of the derivatization procedure. Derivatization is based on silylation with N-Methyl-N-trimethylsilyl-trifluoroacetamide (MSTFA) during the step of thermal desorption. The high temperature of 300 °C during desorption is utilized for the in-situ derivatization on the collection substrate (quartz fibre filters) accelerating the reaction rate. Thereby, the analysis time is as short as without derivatization. At first the filter surface is dampened with derivatization reagent before insertion of the sample into the thermal desorption unit. To ensure ongoing derivatization during thermal desorption the carrier gas is saturated with MSTFA until the desorption procedure is finished. The method introduced here was compared with direct thermal desorption gas chromatography time-of-flight-mass spectrometry (DTD-GC-TOFMS) and with solvent extraction (SE) procedures followed by gas chromatography and mass spectrometry. Comparisons were carried out with field samples originating from ambient aerosol collected on quartz fibre filters. Moreover, the methods have been applied on NIST Standard Reference Material Urban Dust (SRM 1649a).

  1. The effects of crosslinkers on physical, mechanical, and cytotoxic properties of gelatin sponge prepared via in-situ gas foaming method as a tissue engineering scaffold.

    PubMed

    Poursamar, S Ali; Lehner, Alexander N; Azami, Mahmoud; Ebrahimi-Barough, Somayeh; Samadikuchaksaraei, Ali; Antunes, A P M

    2016-06-01

    In this study porous gelatin scaffolds were prepared using in-situ gas foaming, and four crosslinking agents were used to determine a biocompatible and effective crosslinker that is suitable for such a method. Crosslinkers used in this study included: hexamethylene diisocyanate (HMDI), poly(ethylene glycol) diglycidyl ether (epoxy), glutaraldehyde (GTA), and genipin. The prepared porous structures were analyzed using Fourier Transform Infrared Spectroscopy (FT-IR), thermal and mechanical analysis as well as water absorption analysis. The microstructures of the prepared samples were analyzed using Scanning Electron Microscopy (SEM). The effects of the crosslinking agents were studied on the cytotoxicity of the porous structure indirectly using MTT analysis. The affinity of L929 mouse fibroblast cells for attachment on the scaffold surfaces was investigated by direct cell seeding and DAPI-staining technique. It was shown that while all of the studied crosslinking agents were capable of stabilizing prepared gelatin scaffolds, there are noticeable differences among physical and mechanical properties of samples based on the crosslinker type. Epoxy-crosslinked scaffolds showed a higher capacity for water absorption and more uniform microstructures than the rest of crosslinked samples, whereas genipin and GTA-crosslinked scaffolds demonstrated higher mechanical strength. Cytotoxicity analysis showed the superior biocompatibility of the naturally occurring genipin in comparison with other synthetic crosslinking agents, in particular relative to GTA-crosslinked samples.

  2. Natural-gas-hydrate deposits: a review of in-situ properties

    SciTech Connect

    Halleck, P.M.; Pearson, C.; McGuire, P.L.; Hermes, R.; Mathews, M.

    1982-01-01

    The Los Alamos hydrate project has concentrated on: evaluating techniques to produce gas from hydrate deposits to determine critical reservoir and production variables; predicting physical properties of hydrate-containing sediments both for their effects on production models and to allow us to develop geophysical exploration and reservoir characterization techniques; and measuring properties of synthetic hydrate cores in the laboratory. Exploration techniques can help assess the size of potential hydrate deposits and determine which production techniques are appropriate for particular deposits. So little is known about the physical properties of hydrate deposits that it is difficult to develop geophysical techniques to locate or characterize them; but, because of the strong similarity between hydrates and ice, empirical relationships between ice composition and seismic velocity, electrical resistivity, density, and heat capacity that have been established for frozen rocks may be used to estimate the physical properties of hydrate deposits. Resistivities of laboratory permafrost samples are shown to follow a variation of Archie's equation. Both the resistivities and seismic velocities are functions of the unfrozen water content (Sw); however, resistivities are more sensitive to changes in Sw, varying by as much as three orders of magnitude, which may allow the use of electrical resistivity measurements to estimte the amount of hydrate in place. We estimated Sw, assuming that the dissolved salt in the pore water is concentrated as a brine phase as the hydrates form, and the brine content as a function of depth, assuming several temperature gradients and pore water salinities. Hydrate-bearing zones are characterized by high seismic velocities and electrical resistivities compared to unfrozen sediments or permafrost zones.

  3. On the path to the digital rock physics of gas hydrate-bearing sediments - processing of in situ synchrotron-tomography data

    NASA Astrophysics Data System (ADS)

    Sell, Kathleen; Saenger, Erik H.; Falenty, Andrzej; Chaouachi, Marwen; Haberthür, David; Enzmann, Frieder; Kuhs, Werner F.; Kersten, Michael

    2016-08-01

    To date, very little is known about the distribution of natural gas hydrates in sedimentary matrices and its influence on the seismic properties of the host rock, in particular at low hydrate concentration. Digital rock physics offers a unique approach to this issue yet requires good quality, high-resolution 3-D representations for the accurate modeling of petrophysical and transport properties. Although such models are readily available via in situ synchrotron radiation X-ray tomography, the analysis of such data asks for complex workflows and high computational power to maintain valuable results. Here, we present a best-practice procedure complementing data from Chaouachi et al. (2015) with data post-processing, including image enhancement and segmentation as well as exemplary numerical simulations of an acoustic wave propagation in 3-D using the derived results. A combination of the tomography and 3-D modeling opens a path to a more reliable deduction of properties of gas hydrate-bearing sediments without a reliance on idealized and frequently imprecise models.

  4. Effective Use of Molecular Recognition in Gas Sensing: Results from Acoustic Wave and In-Situ FTIR Measurements

    SciTech Connect

    Bodenhofer, K,; Gopel, W.; Hierlemann, A.; Ricco, A.J.

    1998-12-09

    To probe directly the analyte/film interactions that characterize molecular recognition in gas sensors, we recorded changes to the in-situ surface vibrational spectra of specifically fictionalized surface acoustic wave (SAW) devices concurrently with analyte exposure and SAW measurement of the extent of sorption. Fourier-lmnsform infrared external- reflectance spectra (FTIR-ERS) were collected from operating 97-MH2 SAW delay lines during exposure to a range of analytes as they interacted with thin-film coatings previously shown to be selective: cyclodextrins for chiral recognition, Ni-camphorates for Lewis bases such as pyridine and organophosphonates, and phthalocyanines for aromatic compounds. In most cases where specific chemical interactions-metal coordination, "cage" compound inclusion, or z stacking-were expected, analyte dosing caused distinctive changes in the IR spectr~ together with anomalously large SAW sensor responses. In contrast, control experiments involving the physisorption of the same analytes by conventional organic polymers did not cause similar changes in the IR spectra, and the SAW responses were smaller. For a given conventional polymer, the partition coefficients (or SAW sensor signals) roughly followed the analyte fraction of saturation vapor pressure. These SAW/FTIR results support earlier conclusions derived from thickness-shear mode resonator data.

  5. In situ calibration of micro-photoionization detectors in a multi-dimensional micro-gas chromatography system.

    PubMed

    Lee, Jiwon; Zhou, Menglian; Zhu, Hongbo; Nidetz, Robert; Kurabayashi, Katsuo; Fan, Xudong

    2016-06-20

    A photoionization detector (PID) is widely used as a gas chromatography (GC) detector. By virtue of its non-destructive nature, multiple PIDs can be used in multi-dimensional GC. However, different PIDs have different responsivities towards the same chemical compound with the same concentration or mass due to different aging conditions of the PID lamps and windows. Here, we carried out a systematic study regarding the response of 5 Krypton μPIDs in a 1 × 4-channel 2-dimensional μGC system to 7 different volatile organic compounds (VOCs) with the ionization potential ranging from 8.45 eV to 10.08 eV and the concentration ranging from ∼1 ng to ∼2000 ng. We used one of the PIDs as the reference detector and calculated the calibration factor for each of the remaining 4 PIDs against the first PID, which we found is quite uniform regardless of the analyte, its concentration, or chromatographic peak width. Based on the above observation, we were able to quantitatively reconstruct the coeluted peaks in the first dimension using the signal obtained with a PID array in the second dimension. Our work will enable rapid and in situ calibration of PIDs in a GC system using a single analyte at a single concentration. It will also lead to the development of multi-channel multi-dimensional GC where multiple PIDs are employed. PMID:27152367

  6. Structural effect of the in situ generated titania on its ability to oxidize and capture the gas-phase elemental mercury.

    PubMed

    Lee, Tai Gyu; Hyun, Jung Eun

    2006-01-01

    Structural effect of the in situ generated TiO(2) sorbent particle was examined for its ability to capture elemental mercury under UV irradiation in a simulated combustion flue gas. Titania particles were prepared by thermal gas-phase oxidation of Titanium (IV) isopropoxide (TTIP) using a high temperature electric furnace reactor. The structural characteristics of the in situ generated TiO(2) at various synthesis temperatures were investigated; size distribution and the geometric mean diameter were measured using a scanning mobility particle sizer, while fractal dimension and radius of gyration were evaluated from the transmission electron microscopy images. Results from the Hg(0) capture experiment show that with increasing titania synthesis temperature, the overall aggregate size increases and the morphology becomes more open-structured to gas-phase Hg(0) and UV light, resulting in the improved mercury removal capability. PMID:15949836

  7. In situ analysis of agrochemical residues on fruit using ambient ionization on a handheld mass spectrometer.

    PubMed

    Soparawalla, Santosh; Tadjimukhamedov, Fatkhulla K; Wiley, Joshua S; Ouyang, Zheng; Cooks, R Graham

    2011-11-01

    We describe a rapid in situ method for detecting agrochemicals on the surface or in the tissue of fruit using a portable mass spectrometer equipped with an ambient ionization source. Two such ionization methods, low temperature plasma (LTP) and paper spray (PS), were employed in experiments performed at a local grocery store. LTP was used to detect diphenylamine (DPA) directly from the skin of apples in the store and those treated after harvest with DPA were recognized by MS and MS/MS. These data therefore allowed ready distinction between organic and non-organic apples. DPA was also found within the internal tissue of purchased apples and its distribution was mapped using LTP. Similarly, thiabendazole residues were detected on the skin of treated oranges in a grocery store experiment in which paper spray was performed by wiping the orange surface with a moist commercial lens wipe and then applying a high voltage to ionize the chemicals directly from the wipe. The handheld mass spectrometer used in these measurements is capable of performing several stages of tandem mass spectrometry (up to MS(5)); the compounds on the fruit were identified by their MS/MS fragmentation patterns. Protonated DPA (m/z 170) produced a characteristic MS(2) fragment ion at m/z 92, while thiabendazole was identified by MS(3) using precursor to fragment ion transitions m/z 202 →m/z 175 →m/z 131. These particular examples exemplify the power of in situ analysis of complex samples using ambient ionization and handheld mass spectrometers.

  8. Structural characterizaiton and gas reactions of small metal particles by high-resolution, in-situ TEM and TED

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The existing in-situ transmission electron microscopy (TEM) facility was improved by adding a separately pumped mini-specimen chamber. The chamber contains wire-evaporation sources for three metals and a specimen heater for moderate substrate temperatures. A sample introduction device was constructed, installed, and tested, facilitating rapid introduction of a specimen into the mini-chamber while maintaining the background pressure in that chamber in the 10(-9) millibar range. Small particles and clusters of Pd, grown by deposition from the vapor phase in an in-situ TEM facility on amorphous and crystalline support films of alumina and on ultra-thin carbon films, were analyzed by conventional high-resolution TEM and image analysis in terms of detectability, number density, and size distribution. The smallest particles that could be detected and counted contained no more than 6 atoms; size determinations could be made for particles 1 nm in diameter. The influence of various oxygen plasma treatments, annealing treatments, and of increasing the substrate temperature during deposition was investigated. The TEM technique was employed to demonstrate that under otherwise identica l conditions the lattice parameter of Pd particles in the 1 to 2 nm size range and supported in random orientation on ex-situ prepared mica films is expanded by some 3% when compared to 5 nm size particles. It is believed that this expansion is neither a small-particle diffraction effect nor due to pseudomorphism, but that it is due to a annealing-induced transformation of the small as-deposited particles with predominantly composite crystal structures into larger particles with true f.c.c. structure and thus inherently smaller lattice parameter.

  9. Development of a screened cathode gas flow proportional counter for in situ field determination of alpha contamination in soil

    SciTech Connect

    Bush, S.P.

    1997-02-01

    This study resulted in the design, construction and testing of a gas flow proportional counter for in-situ determination of soil contamination. The uniqueness of this detector is the screened material used for the cathode. A Pu-239 source of 0.006 {micro}Ci was mounted to the outside of the cathode to simulate radioactive soil. The detector probe was placed into a laboratory mock-up and tested to determine operating voltage, efficiency and energy resolution. Two gas flow proportional counters were built and tested. The detectors are cylindrical, each with a radius of 1.905 cm, having an anode wire with a radius of 0.0038 cm. The length of the smaller detector`s anode was 2.54 cm, and the length of the larger detector`s anode was 7.64 cm. Therefore, the active volumes were 28.96 cm{sup 3} and 87.10 cm{sup 3}, respectively, for the small and large detector. An operating voltage of 1,975 volts was determined to be sufficient for both detectors. The average efficiency was 2.59 {+-} 0.12% and 76.71 {+-} 10.81% for the small volume and large volume detectors, respectively. The average energy resolution for the low-energy peak of the small detector was 4.24 {+-} 1.28% and for the large-energy peak was 1.37 {+-} 0.66%. The large detectors` energy resolution was 17.75 {+-} 3.74%. The smaller detector, with better energy resolution, exhibited a bi-modal spectrum, whereas the larger detector`s spectrum centered around a single broad peak.

  10. Quantitative analysis for in situ sintering of 3% yttria-stablized zirconia in the transmission electron microscope.

    PubMed

    Majidi, Hasti; Holland, Troy B; van Benthem, Klaus

    2015-05-01

    Studying particle-agglomerate systems compared to two-particle systems elucidates different stages of sintering by monitoring both pores and particles. We report on in situ sintering of 3% yttria-stablized zirconia particle agglomerates in the transmission electron microscope (TEM). Real-time TEM observations indicate neck formation and growth, particle coalescence and pore closure. A MATLAB-based image processing tool was developed to calculate the projected area of the agglomerate with and without internal pores during in situ sintering. We demonstrate the first densification curves generated from sequentially acquired TEM images. The in situ sintering onset temperature was then determined to be at 960 °C. Densification curves illustrated that the agglomerate projected area which excludes the internal observed pores also shrinks during in situ sintering. To overcome the common projection problem for TEM analyses, agglomerate mass-thickness maps were obtained from low energy-loss analysis combined with STEM imaging. The decrease in the projected area was directly related to the increase in mass-thickness of the agglomerate, likely caused by hidden pores existing in the direction of the beam. Access to shrinkage curves through in situ TEM analysis provides a new avenue to investigate fundamental mechanisms of sintering through directly correlating microstructural changes during consolidation with mesoscale densification behavior. PMID:25600824

  11. Engineering feasibility analysis for in-situ stabilization of Canonsburg residues. [UMTRA project

    SciTech Connect

    Not Available

    1982-01-01

    The US Department of Energy is considering several methods for carrying out remedial actions in Canonsburg, Pennsylvania, at the site of an inactive uranium-processing mill. The main objective of this study is to determine the feasibility of in-situ stabilization as the remedial action. In-situ stabilization is an alternative to site decontamination and offsite disposal. The problems associated with offsite hauling of large quantities of contaminated material and with the location and development of a new disposal site could be avoided by the implementation of an in-situ stabilization concept. In addition, the in-situ approach would be more cost-effective than offsite disposal. This study will establish that a technically feasible and implementable in-situ stabilization concept can be developed that meets regulatory requirements and is cost effective. This study in no way commits the DOE to implement any specific actions described herein. 11 refs., 30 figs., 24 tabs.

  12. In-situ Characterization of Gas Phase Organic Emissions from a Medium Duty Diesel Engine

    NASA Astrophysics Data System (ADS)

    Cross, E. S.; Sappok, A.; Hunter, J. F.; Jayne, J.; Wong, V. W.; Worsnop, D. R.; Kroll, J. H.

    2012-12-01

    With volatilities slightly lower than VOCs, intermediate volatility organic compounds (IVOCs; e.g. C13-C20 n-alkanes) and semi-volatile organic compounds (SVOCs; e.g. C21-C32 n-alkanes) comprise an important, largely unmeasured part of the organic carbon emission profile of a diesel engine. Similar to VOCs, I/SVOCs have important impacts on air quality and climate, serving as precursor species to secondary organic aerosol (SOA) formation, but a detailed understanding of SOA formation from I/SVOCs remains incomplete due to a lack of fast, reliable measurement techniques that target I/SVOCs. This paper presents experimental results obtained with a recently developed technique that combines cryogenic collection and electron-impact, high-resolution time-of-flight mass spectrometry to enable fast, quantitative, volatility-resolved, bulk characterization of I/SVOCs. In this experiment, I/SVOC tailpipe emissions from a Cummins (5.9 L) 2002 ISB 300 engine were measured as a function of engine speed and load during steady-state and transient conditions, including numerous cold starts. Analysis of the high resolution mass spectra reveal evolving hydrocarbon and oxygenated hydrocarbon signatures as a function of engine block temperature and engine load. The exhaust sampling apparatus included the ability to test different emission control technologies. For a subset of tests, a diesel particulate filter (DPF) was integrated into the exhaust system to characterize post-DPF I/SVOC emissions during soot loading and DPF-regeneration cycles.

  13. Enabling Graph Mining in RDF Triplestores using SPARQL for Holistic In-situ Graph Analysis

    SciTech Connect

    Lee, Sangkeun; Sukumar, Sreenivas R; Hong, Seokyong; Lim, Seung-Hwan

    2016-01-01

    The graph analysis is now considered as a promising technique to discover useful knowledge in data with a new perspective. We envi- sion that there are two dimensions of graph analysis: OnLine Graph Analytic Processing (OLGAP) and Graph Mining (GM) where each respectively focuses on subgraph pattern matching and automatic knowledge discovery in graph. Moreover, as these two dimensions aim to complementarily solve complex problems, holistic in-situ graph analysis which covers both OLGAP and GM in a single system is critical for minimizing the burdens of operating multiple graph systems and transferring intermediate result-sets between those systems. Nevertheless, most existing graph analysis systems are only capable of one dimension of graph analysis. In this work, we take an approach to enabling GM capabilities (e.g., PageRank, connected-component analysis, node eccentricity, etc.) in RDF triplestores, which are originally developed to store RDF datasets and provide OLGAP capability. More specifically, to achieve our goal, we implemented six representative graph mining algorithms using SPARQL. The approach allows a wide range of available RDF data sets directly applicable for holistic graph analysis within a system. For validation of our approach, we evaluate performance of our implementations with nine real-world datasets and three different computing environments - a laptop computer, an Amazon EC2 instance, and a shared-memory Cray XMT2 URIKA-GD graph-processing appliance. The experimen- tal results show that our implementation can provide promising and scalable performance for real world graph analysis in all tested environments. The developed software is publicly available in an open-source project that we initiated.

  14. Enabling Graph Mining in RDF Triplestores using SPARQL for Holistic In-situ Graph Analysis

    DOE PAGES

    Lee, Sangkeun; Sukumar, Sreenivas R; Hong, Seokyong; Lim, Seung-Hwan

    2016-01-01

    The graph analysis is now considered as a promising technique to discover useful knowledge in data with a new perspective. We envi- sion that there are two dimensions of graph analysis: OnLine Graph Analytic Processing (OLGAP) and Graph Mining (GM) where each respectively focuses on subgraph pattern matching and automatic knowledge discovery in graph. Moreover, as these two dimensions aim to complementarily solve complex problems, holistic in-situ graph analysis which covers both OLGAP and GM in a single system is critical for minimizing the burdens of operating multiple graph systems and transferring intermediate result-sets between those systems. Nevertheless, most existingmore » graph analysis systems are only capable of one dimension of graph analysis. In this work, we take an approach to enabling GM capabilities (e.g., PageRank, connected-component analysis, node eccentricity, etc.) in RDF triplestores, which are originally developed to store RDF datasets and provide OLGAP capability. More specifically, to achieve our goal, we implemented six representative graph mining algorithms using SPARQL. The approach allows a wide range of available RDF data sets directly applicable for holistic graph analysis within a system. For validation of our approach, we evaluate performance of our implementations with nine real-world datasets and three different computing environments - a laptop computer, an Amazon EC2 instance, and a shared-memory Cray XMT2 URIKA-GD graph-processing appliance. The experimen- tal results show that our implementation can provide promising and scalable performance for real world graph analysis in all tested environments. The developed software is publicly available in an open-source project that we initiated.« less

  15. Investigating ancient microbial biosignatures with Micro-XRF in situ elemental analysis

    NASA Astrophysics Data System (ADS)

    Allwood, A.; Hurowitz, J.; Tice, M. M.; Hodyss, R. P.; Knowles, E. J.; Wade, L.

    2013-12-01

    Identifying ancient microbial biosignatures in the geologic record is about assembling a body of evidence, and almost never involves a "smoking gun". When a potential biosignature such as a microfossil, organic deposit or stromatolite is found, sources of evidence for testing the biogenic hypothesis include the inherent properties of the feature itself, the assemblage characteristics of multiple candidate features, the geologic context of the features, and the relationship between changes in the features and changes in the geologic context. Given these diverse sources of evidence, multiple analytical techniques necessarily come into play. Some of the most powerful techniques emerging for ancient biosignature investigations are those that analyze composition in situ, enabling correlation between morphological observations and elemental, mineralogical, molecular and isotopic measurements. The push in this area of analysis has been toward higher spatial resolution methods, while larger scale measurements have remained largely the purview of reflected light analysis of polished slabs. This latter realm of investigation is an area ripe for innovation because larger scale (naked-eye to hand lens) observations have a unifying role that is particularly important in guiding the application of high resolution techniques, understanding the context of high resolution measurements, integrating the high resolution data sets, and providing a concrete link to outcrop scale investigations. One method that is emerging for in situ compositional analysis at naked-eye to hand lens scales is micro x-ray fluorescence, or micro-XRF. Micro-XRF scans a focused X-ray beam across the surface of a rock to create a map of elemental composition at mm-cm scales, comprising individual spot measurements of 10-100 microns diameter (typical). We have applied micro-XRF to diverse geological samples including ancient stromatolites and shales, and found that the element maps are not only a highly

  16. Fully integrated wearable sensor arrays for multiplexed in situ perspiration analysis

    DOE PAGES

    Gao, Wei; Emaminejad, Sam; Nyein, Hnin Yin Yin; Challa, Samyuktha; Chen, Kevin; Peck, Austin; Fahad, Hossain M.; Ota, Hiroki; Shiraki, Hiroshi; Kiriya, Daisuke; et al

    2016-01-27

    We report that wearable sensor technologies are essential to the realization of personalized medicine through continuously monitoring an individual’s state of health. Sampling human sweat, which is rich in physiological information13, could enable non-invasive monitoring. Previously reported sweat-based and other noninvasive biosensors either can only monitor a single analyte at a time or lack on-site signal processing circuitry and sensor calibration mechanisms for accurate analysis of the physiological state14–18. Given the complexity of sweat secretion, simultaneous and multiplexed screening of target biomarkers is critical and requires full system integration to ensure the accuracy of measurements. Here we present a mechanicallymore » flexible and fully integrated (that is, no external analysis is needed) sensor array for multiplexed in situ perspiration analysis, which simultaneously and selectively measures sweat metabolites (such as glucose and lactate) and electrolytes (such as sodium and potassium ions), as well as the skin temperature (to calibrate the response of the sensors). Lastly, our work bridges the technological gap between signal transduction, conditioning (amplification and filtering), processing and wireless transmission in wearable biosensors by merging plasticbased sensors that interface with the skin with silicon integrated circuits consolidated on a flexible circuit board for complex signal processing.« less

  17. Detecting Combustion and Flow Features In Situ Using Principal Component Analysis

    SciTech Connect

    Thompson, David; Grout, Ray W.; Fabian, Nathan D.; Bennett, Janine Camille

    2009-03-01

    This report presents progress on identifying and classifying features involving combustion in turbulent flow using principal component analysis (PCA) and k-means clustering using an in situ analysis framework. We describe a process for extracting temporally- and spatially-varying information from the simulation, classifying the information, and then applying the classification algorithm to either other portions of the simulation not used for training the classifier or further simulations. Because the regions classified as being of interest take up a small portion of the overall simulation domain, it will consume fewer resources to perform further analysis or save these regions at a higher fidelity than previously possible. The implementation of this process is partially complete and results obtained from PCA of test data is presented that indicates the process may have merit: the basis vectors that PCA provides are significantly different in regions where combustion is occurring and even when all 21 species of a lifted flame simulation are correlated the computational cost of PCA is minimal. What remains to be determined is whether k-means (or other) clustering techniques will be able to identify combined combustion and flow features with an accuracy that makes further characterization of these regions feasible and meaningful.

  18. Study of field assessment methods and worker risks for processing alternatives to support principles for FUSRAP waste materials. Part 2: Preliminary development of a wall-less gas-flow proportional counter for in-situ field analysis of nuclear contamination in soil

    SciTech Connect

    Bush, S.P.; Hamby, D.M.; Martin, J.E.

    1997-03-01

    This study resulted in the design, construction and testing of a gas flow proportional counter for in-situ determination of soil contamination. The uniqueness of this detector is the screened material used for the cathode. A Pu-239 source of 0.006 {micro}Ci was mounted to the outside of the cathode to simulate radioactive soil. The detector probe was placed into a laboratory mock-up and tested to determine operating voltage, efficiency and energy resolution. Two gas flow proportional counters were built and tested. The detectors are cylindrical, each with a radius of 1.905 cm, having an anode wire with a radius of 0.0038 cm. The length of the smaller detector`s anode was 2.54 cm, and the length of the larger detector`s anode was 7.64 cm. Therefore, the active volumes were 28.96 cm{sup 3} and 87.10 cm{sup 3}, respectively, for the small and large detector. An operating voltage of 1975 volts was determined to be sufficient for both detectors. The average efficiency was 2.59 {+-} 0.12% and 76.71 {+-} 10.81% for the small volume and large volume detectors, respectively. The average energy resolution for the low-energy peak of the small detector was 4.24 {+-} 1.28% and for the large-energy peak was 1.37 {+-} 0.66%. The large detectors` energy resolution was 17.75 {+-} 3.74%. The smaller detector, with better energy resolution, exhibited a bi-modal spectrum, whereas the larger detector`s spectrum centered around a single broad peak.

  19. Spatially Resolved, In Situ Carbon Isotope Analysis of Archean Organic Matter

    NASA Technical Reports Server (NTRS)

    Williford, Kenneth H.; Ushikubo, Takayuki; Lepot, Kevin; Hallmann, Christian; Spicuzza, Michael J.; Eigenbrode, Jennifer L.; Summons, Roger E.; Valley, John W.

    2011-01-01

    Spatiotemporal variability in the carbon isotope composition of sedimentary organic matter (OM) preserves information about the evolution of the biosphere and of the exogenic carbon cycle as a whole. Primary compositions, and imprints of the post-depositional processes that obscure them, exist at the scale of individual sedimentary grains (mm to micron). Secondary ion mass spectrometry (SIMS) (1) enables analysis at these scales and in petrographic context, (2) permits morphological and compositional characterization of the analyte and associated minerals prior to isotopic analysis, and (3) reveals patterns of variability homogenized by bulk techniques. Here we present new methods for in situ organic carbon isotope analysis with sub-permil precision and spatial resolution to 1 micron using SIMS, as well as new data acquired from a suite of Archean rocks. Three analytical protocols were developed for the CAMECA ims1280 at WiscSIMS to analyze domains of varying size and carbon concentration. Average reproducibility (at 2SD) using a 6 micron spot size with two Faraday cup detectors was 0.4 %, and 0.8 % for analyses using 1 micron and 3 micron spot sizes with a Faraday cup (for C-12) and an electron multiplier (for C-13). Eight coals, two ambers, a shungite, and a graphite were evaluated for micron-scale isotopic heterogeneity, and LCNN anthracite (delta C-13 = -23.56 +/- 0.1 %, 2SD) was chosen as the working standard. Correlation between instrumental bias and H/C was observed and calibrated for each analytical session using organic materials with H/C between 0.1 and 1.5 (atomic), allowing a correction based upon a C-13H/C-13 measurement included in every analysis. Matrix effects of variable C/SiO2 were evaluated by measuring mm to sub-micron graphite domains in quartzite from Bogala mine, Sri Lanka. Apparent instrumental bias and C-12 count rate are correlated in this case, but this may be related to a crystal orientation effect in graphite. Analyses of amorphous

  20. A Transport Analysis of In Situ Airborne Ozone Measurements from the 2011 DISCOVER-AQ Campaign

    NASA Astrophysics Data System (ADS)

    Arkinson, H. L.; Brent, L. C.; He, H.; Loughner, C.; Stehr, J. W.; Weinheimer, A. J.; Dickerson, R. R.

    2013-12-01

    Baltimore and Washington are currently designated as nonattainment areas with respect to the 2008 EPA National Ambient Air Quality Standard (NAAQS) for 8-hour Ozone (O3). Tropospheric O3 is the dominant component of summertime photochemical smog, and at high levels, has deleterious effects on human health, ecosystems, and materials. The University of Maryland (UMD) Regional Atmospheric Measurement Modeling and Prediction Program (RAMMPP) strives to improve understanding of air quality in the Mid-Atlantic States and to elucidate contributions of pollutants such as O3 from regional transport versus local sources through a combination of modeling and in situ measurements. The NASA Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) project investigates the connection between column measurements and surface conditions to explore the potential of remote sensing observations in diagnosing air quality at ground level where pollutants can affect human health. During the 2011 DISCOVER-AQ field campaign, in situ airborne measurements of trace gases and aerosols were performed along the Interstate 95 corridor between Baltimore and Washington from the NASA P3B aircraft. To augment this data and provide regional context, measurements of trace gases and aerosols were also performed by the RAMMPP Cessna 402B aircraft over nearby airports in Maryland and Virginia. This work presents an analysis of O3 measurements made by the Ultraviolet (UV) Photometric Ambient O3 Analyzer on the RAMMPP Cessna 402B and by the NCAR 4-Channel Chemiluminescence instrument on the NASA P3B. In this analysis, spatial and temporal patterns of O3 data are examined within the context of forward and backward trajectories calculated from 12-km North American Mesoscale (NAM) meteorological data using the NOAA Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) Model and from a high resolution Weather Research and

  1. In Situ Space Gas Dynamic Measurements by the ROSINA Comet Pressure Sensor COPS on the Rosetta Spacecraft

    NASA Astrophysics Data System (ADS)

    Tzou, C. Y.; Altwegg, K.; Fiethe, B.; Gasc, S.; Rubin, M.

    2014-12-01

    Rosetta is part of the cornerstone missions executed by the European Space Agency. It is the first space mission to orbit and also land on a comet. Starting in August 2014 Rosetta will be able to carry out a close study of comet 67P/Churyumov-Gerasimenko. The Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) is one of the core payloads on board of the Rosetta spacecraft [Balsiger et al, 2007]. ROSINA's main objective is to determine the major atmospheric and ionospheric composition in the coma and to investigate the gas dynamics around the comet. ROSINA consists of two mass spectrometers and a pressure sensor. The Comet Pressure Sensor (COPS) includes two gauges: the "nude gauge" measures total neutral density in the coma and the "ram gauge" measures the dynamic pressure of the cometary gas flux to obtain the bulk velocity of the neutral gas. The combination of these two gauges makes COPS capable to derive the gas dynamics at the location of the spacecraft. We performed laboratory gas dynamic measurements with the identical flight-spare instrument of COPS. Using the Calibration System for The Mass Spectrometer Instrument ROSINA (CASYMIR) we produce neutral gas beams to model cometary gas jets with velocities from thermal up to 2 km/s. We expect that COPS will be able to detect the faint and expanding atmosphere of comet 67P/Churyumov-Gerasimenko as early as August 2014 when the comet is still farther than 3 AU from the Sun. We will present the first ROSINA COPS observations of the gas dynamics around the comet together with the corresponding laboratory measurements required for the interpretation of these data. Reference: Balsiger, H. et al.: ROSINA-Rosetta Orbiter Spectrometer for Ion and Neutral Analysis, Space Science Reviews, Vol. 128, 745-801, 2007.

  2. Comparative Study of δ18O Compositions Determined for Fossil Holocene Planktic Foraminifera by In Situ SIMS Measurements and Standard Gas-Source IRMS Bulk Shell Analyses

    NASA Astrophysics Data System (ADS)

    Wycech, J.; Kelly, D. C.; Kozdon, R.; Kitajima, K.; Spero, H. J.; Orland, I. J.; Kita, N.; Valley, J. W.

    2015-12-01

    The use of SIMS to perform in situ δ18O analyses on micron-scale domains within individual foraminiferal shells is an emerging technique that holds much promise for elucidating new paleoclimate information from deep-sea records. High precision and accuracy are possible for inorganic calcite, but continued testing is essential to establish the accuracy of this novel technique for biocarbonates; hence, a comparative study was conducted using both in situ SIMS (IMS 1280) and standard gas-source IRMS analyses to measure the δ18O in the same chamber of a foraminifera shell. An initial experiment was performed on 18 Orbulina universa shells (~600 μm) exhibiting varying states of preservation (3 well-preserved glassy, 1 intermediate, 14 frosty) handpicked from the uppermost 2 cm (Holocene) of a piston core (PC9) retrieved from the northwestern Atlantic. The spherical chamber of each shell was manually broken into smaller fragments with the majority of the fragments pooled for δ18O analysis by IRMS, and a remaining fragment cast in epoxy for SIMS. Comparison of average SIMS δ18O values to corresponding IRMS δ18O values for the same chamber reveals a linear relationship across a 3‰ range in glassy and frosty shells with the SIMS values being 0.9 ± 0.7‰ (2SD) lower. This 0.9‰ offset is also seen in O. universa shells (1 glassy, 3 intermediate, 10 frosty) that have undergone hydrogen peroxide cleaning and sonication. The δ18O offset is being further investigated using manually fragmented O. universa shells from the core-top of PC9 that have been vacuum roasted as well as cultured specimens grown under controlled conditions. Through these additional experiments we are exploring possible offset mechanisms including: errors in SIMS and gas-source analysis; differences between the coarsely crystalline homogeneous SIMS standards and complex biocarbonate samples; and zoning in shells due to growth, diagenesis or other components not targeted by SIMS.

  3. Field emission from α-Fe2O3 nanoflakes: Effect of vacuum pressure, gas adsorption and in-situ thermal treatment

    NASA Astrophysics Data System (ADS)

    Wu, J. Q.; Deng, S. Z.; Xu, N. S.; Chen, Jun

    2014-02-01

    The effects of vacuum pressure and gas adsorption on field emission current of α-Fe2O3 nanoflakes were studied. It was found that field emission current of α-Fe2O3 nanoflakes decreased with increasing pressure. The field emission current decreased when N2 or O2 was introduced into chamber, while no obvious change was observed for H2 gas. An in-situ thermal treatment was carried out to eradicate the effect of absorbed gas. After the in-situ thermal treatment, the field emission current density was largely enhanced from 60 to 500 μA/cm2 under applied electrical field of 10 MV/m and the turn on field (Eturn-on) decreased from 7.6 to 5.2 MV/m. The lowered turn-on field was attributed to the decrease of surface work function induced by surface gas desorption and reduction of α-Fe2O3 nanoflakes. Moreover, the improvement of field emission performance can be retained in high vacuum condition, which indicates the in-situ thermal treatment is an efficient method to improve field emission properties of α-Fe2O3 nanoflakes.

  4. Deuterium Gas Analysis by Residual Gas Analyzer

    NASA Astrophysics Data System (ADS)

    Das, B. K.; Shukla, R.; Das, R.; Shyam, A.; Rao, A. D. P.

    2012-11-01

    Hydrogen gas is generated by electrolysis method in a compact hydrogen generator. A simple procedure reduces handling and storage of hydrogen cylinders for laboratory applications. In such a system, we are producing deuterium gas from heavy water by electrolysis method. After production of the deuterium gas, we have checked the purity level of the outgoing deuterium from the electrolyser. The test was carried out in a high vacuum system in which one residual gas analyser (RGA) was mounted. The deuterium gas was inserted by one manual gas leak valve in to the vacuum system. In this study, the effect of the emission current of the RGA on the detection of the deuterium was performed. In this paper, we will discuss the detail analysis of the deuterium gas and the effect of the emission current on the partial pressure measurement.

  5. Potential clinical impact of three-dimensional visualization for fluorescent in situ hybridization image analysis

    NASA Astrophysics Data System (ADS)

    Li, Zheng; Li, Shibo; Bin, Zheng; Zhang, Roy; Li, Yuhua; Tian, Huimin; Chen, Wei; Liu, Hong

    2012-05-01

    Chromosomal translocation is strong indication of cancers. Fluorescent in situ hybridization (FISH) can effectively detect this translocation and achieve high accuracy in disease diagnosis and prognosis assessment. For this purpose, whole chromosome paint probes are utilized to image the configuration of DNA fragments. Although two-dimensional (2-D) microscopic images are typically used in FISH signal analysis, we present a case where the translocation occurs in the depth direction where two probed FISH signals are overlapped in the projected image plane. Thus, the translocation cannot be identified. However, when imaging the whole specimen with a confocal microscope at 27 focal planes with 0.5-μm step interval, the translocation can be clearly identified due to the free rotation capability by the three-dimensional (3-D) visualization. Such a translocation detection error of using 2-D images might be critical in detecting and diagnosing early or subtle disease cases where detecting a small number of abnormal cells can make diagnostic difference. Hence, the underlying implication of this report suggests that utilizing 3-D visualization may improve the overall accuracy of FISH analysis for some clinical cases. However, the clinical efficiency and cost of using 3-D versus 2-D imaging methods are also to be assessed carefully.

  6. Exploring laser-induced breakdown spectroscopy for nuclear materials analysis and in-situ applications

    NASA Astrophysics Data System (ADS)

    Martin, Madhavi Z.; Allman, Steve; Brice, Deanne J.; Martin, Rodger C.; Andre, Nicolas O.

    2012-08-01

    Laser-induced breakdown spectroscopy (LIBS) has been used to determine the limits of detection of strontium (Sr) and cesium (Cs), common nuclear fission products. Additionally, detection limits were determined for cerium (Ce), often used as a surrogate for radioactive plutonium in laboratory studies. Results were obtained using a laboratory instrument with a Nd:YAG laser at fundamental wavelength of 1064 nm, frequency doubled to 532 nm with energy of 50 mJ/pulse. The data was compared for different concentrations of Sr and Ce dispersed in a CaCO3 (white) and carbon (black) matrix. We have addressed the sampling errors, limits of detection, reproducibility, and accuracy of measurements as they relate to multivariate analysis in pellets that were doped with the different elements at various concentrations. These results demonstrate that LIBS technique is inherently well suited for in situ analysis of nuclear materials in hot cells. Three key advantages are evident: (1) small samples (mg) can be evaluated; (2) nuclear materials can be analyzed with minimal sample preparation; and (3) samples can be remotely analyzed very rapidly (ms-seconds). Our studies also show that the methods can be made quantitative. Very robust multivariate models have been used to provide quantitative measurement and statistical evaluation of complex materials derived from our previous research on wood and soil samples.

  7. Exploring laser-induced breakdown spectroscopy for nuclear materials analysis and in-situ applications

    SciTech Connect

    Martin, Madhavi Z; Allman, Steve L; Brice, Deanne Jane; Martin, Rodger Carl; Andre, Nicolas O

    2012-01-01

    Laser-induced breakdown spectroscopy (LIBS) has been used to determine the limits of detection of strontium (Sr) and cesium (Cs), common nuclear fission products. Additionally, detection limits were determined for cerium (Ce), often used as a surrogate for radioactive plutonium in laboratory studies. Results were obtained using a laboratory instrument with a Nd:YAG laser at fundamental wavelength of 1064 nm, frequency doubled to 532 nm with energy of 50 mJ/pulse. The data was compared for different concentrations of Sr and Ce dispersed in a CaCO3 (white) and carbon (black) matrix. We have addressed the sampling errors, limits of detection, reproducibility, and accuracy of measurements as they relate to multivariate analysis in pellets that were doped with the different elements at various concentrations. These results demonstrate that LIBS technique is inherently well suited for in situ analysis of nuclear materials in hot cells. Three key advantages are evident: (1) small samples (mg) can be evaluated; (2) nuclear materials can be analyzed with minimal sample preparation; and (3) samples can be remotely analyzed very rapidly (ms-seconds). Our studies also show that the methods can be made quantitative. Very robust multivariate models have been used to provide quantitative measurement and statistical evaluation of complex materials derived from our previous research on wood and soil samples.

  8. Development of a portable ESPI system for the analysis in situ of mural paintings

    NASA Astrophysics Data System (ADS)

    Boaglio, E.; Lamas, J.; López, Ana J.; Ramil, A.; Pereira, L.; Prieto, B.; Silva, B.

    2012-10-01

    The use of Electronic Speckle Pattern Interferometry (ESPI) is well documented in the literature as a non-destructive technique for structural diagnostics in the field of cultural heritage.. In the case of mural paintings the lack of adhesion between the plaster and the mural support is one of the most important risk factors that threaten their conservation. With this non-invasive method it is possible to detect detachments and cracks in the paintings before they become visible The objective of this work is the development of ESPI portable equipment based on a fibre interferometer for in situ qualitative analysis of mural paintings. The novelty of the presented set up is the use of a variable ratio coupler which makes the system more immune to vibrations and allows for better use of available light compared with the equivalent of free air guided. This configuration simplifies the arrangement and makes it possible to obtain ESPI interferograms with high contrast; moreover, the use of a ceramic heater as excitation source enables the analysis during the heating. Preliminary results obtained in laboratory conditions have shown that detachments and cracks can be successfully detected on model samples of the wall paintings.

  9. Microfluidic electrochemical device and process for chemical imaging and electrochemical analysis at the electrode-liquid interface in-situ

    DOEpatents

    Yu, Xiao-Ying; Liu, Bingwen; Yang, Li; Zhu, Zihua; Marshall, Matthew J.

    2016-03-01

    A microfluidic electrochemical device and process are detailed that provide chemical imaging and electrochemical analysis under vacuum at the surface of the electrode-sample or electrode-liquid interface in-situ. The electrochemical device allows investigation of various surface layers including diffuse layers at selected depths populated with, e.g., adsorbed molecules in which chemical transformation in electrolyte solutions occurs.

  10. In-Situ Study of Gaseous Reduction of Magnetite Doped with Alumina Using High-Temperature XRD Analysis

    NASA Astrophysics Data System (ADS)

    Kapelyushin, Yury; Sasaki, Yasushi; Zhang, Jianqiang; Jeong, Sunkwang; Ostrovski, Oleg

    2015-12-01

    The reduction of magnetite of technical grade and magnetite doped with 3 mass pct Al2O3 was studied in situ using high-temperature XRD (HT-XRD) analysis. Magnetite was reduced by CO-CO2 gas (80 vol pct CO) at 1023 K (750 °C). Reduction of magnetite doped with alumina occurred from the Fe3O4-FeAl2O4 solid solution which has a miscibility gap with critical temperature of 1133 K (860 °C). The degree of reduction of magnetite was derived using Rietveld refinement of the HT-XRD spectra; the compositions of the Fe3O4-FeAl2O4 solid solution and the concentrations of carbon in γ-iron were determined from the lattice constants of the solutions. The reduction of magnetite progressed topochemically with the formation of a dense iron shell. The reduction of alumina-containing magnetite started along certain lattice planes with the formation of a network-like structure. Reduction of alumina-containing magnetite was faster than that of un-doped magnetite; this difference was attributed to the formation of the network-like structure. Hercynite content in the Fe3O4-FeAl2O4 solid solution in the process of reduction of magnetite doped with 3 mass pct Al2O3 increased from 5.11 to 20 mass pct, which is close to the miscibility gap at 1023 K (750 °C). The concentration of carbon in γ-Fe (0.76 mass pct) formed in the reduced sample of magnetite doped with 3 mass pct Al2O3 was close to the equilibrium value with 80 vol pct CO to 20 vol pct CO2 gas used in the HT-XRD experiments.

  11. Thermogravimetry and Molecularly Imprinted Polymers as Tools for In-Situ Analysis of Planetary Environments

    NASA Astrophysics Data System (ADS)

    Palomba, E.; Longobardo, A.; Dirri, F.; Biondi, D.; Zampetti, E.; Pantalei, S.; Bearzotti, A.; Macagnano, A.; Zinzi, A.; Saggin, B.; Baggiani, C.

    2012-10-01

    VISTA (Volatile In Situ Thermogravimetry Analyser) is an instrument developed at IAPS-INAF. It is a thermogravimeter-biosensor system, which aims to measure abundance of volatile compounds and detect biogenic molecules in any planetary environment.

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

    PubMed

    Shrestha, Bindesh; Patt, Joseph M; Vertes, Akos

    2011-04-15

    Molecular imaging by mass spectrometry (MS) is emerging as a tool to determine the distribution of proteins, lipids, and metabolites in tissues. The existing imaging methods, however, mostly rely on predefined rectangular grids for sampling that ignore the natural cellular organization of the tissue. Here we demonstrate that laser ablation electrospray ionization (LAESI) MS can be utilized for in situ cell-by-cell imaging of plant tissues. The cell-by-cell molecular image of the metabolite cyanidin, the ion responsible for purple pigmentation in onion (Allium cepa) epidermal cells, correlated well with the color of cells in the tissue. Chemical imaging using single-cells as voxels reflects the spatial distribution of biochemical differences within a tissue without the distortion stemming from sampling multiple cells within the laser focal spot. Microsampling by laser ablation also has the benefit of enabling the analysis of very small cell populations for biochemical heterogeneity. For example, with a ∼30 μm ablation spot we were able to analyze 3-4 achlorophyllous cells within an oil gland on a sour orange (Citrus aurantium) leaf. To explore cell-to-cell variations within and between tissues, multivariate statistical analysis on LAESI-MS data from epidermal cells of an A. cepa bulb and a C. aurantium leaf and from human buccal epithelial cell populations was performed using the method of orthogonal projections to latent structures discriminant analysis (OPLS-DA). The OPLS-DA analysis of mass spectra, containing over 300 peaks each, provided guidance in identifying a small number of metabolites most responsible for the variance between the cell populations. These metabolites can be viewed as promising candidates for biomarkers that, however, require further verification. PMID:21388149

  13. In-situ Strontium Isotopes Analysis on Single Conodont Apatite by LA-MC-ICP-MS

    NASA Astrophysics Data System (ADS)

    Zhao, L.; Zhang, L.; Chen, Z. Q.; Ma, D.; Qiu, H.; Lv, Z.; Hu, Z.; Wang, F.

    2014-12-01

    Strontium isotope played an important role in stratigraphic chronology and sedimentary geochemistry research (McArthur et al., 2001). Conodonts is a kind of extinct species of marine animals and widely distributed in marine sediments all over the world. Rich in radiogenic Sr contents and difficulty to be affected during diagenesis alteration makes conodonts a good choice in seawater Sr isotope composition studies (John et al., 2008). Conodont samples were collected from 24th to 39th layer across Permian-Triassic boundary at Meishan D section (GSSP), Zhejiang Province, South China (Yin et al., 2001). Conodonts was originated from fresh limestone and only conodont elements with CAI<2 were chosen for in-situ strontium isotope analysis using laser-ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS). Conodont samples are from totally 25 layers in seven conodont zones making it possible for a high resolution 87Sr/ 86Sr curve reconstruction during the Permian-Triassic transition. 87Sr/ 86Sr ratio kept a relatively high value (0.70752) in the middle part of the Clarkina yini zone and a lower value (0.70634) in the upperpart of Clarkina taylorae zone. Of which, 87Sr/ 86Sr ratio emerged a rapid decrease within the Clarkina taylorae zone. After a subsequent increase, 87Sr/ 86Sr ratio dropped to 0.70777 in the Isarcicella staeschei zone. These results helps providing reference data for the biological mass extinction events during the Permian-Triassic transition. Our study also makes is possible for high resolution 87Sr/ 86Sr ratio testing on the single conodont apatite and riched the in-situ studies on the conodont apatite, which of great significance for the future conodont Sr isotope research (Zhao et al., 2009; Zhao et al., 2013). Keywords: Conodonts, Strontium isotope, LA-MC-ICP-MS, Permian-Triassic transition, Meishan D section [1] John et al., 2008 3P[2] McArthur et al., 2001 J. of Geology [3] Yin et al., 2001 Episodes [4] Zhao et al

  14. Distributed Data-Flow for In-Situ Visualization and Analysis at Petascale

    SciTech Connect

    Laney, D E; Childs, H R

    2009-03-13

    We conducted a feasibility study to research modifications to data-flow architectures to enable data-flow to be distributed across multiple machines automatically. Distributed data-flow is a crucial technology to ensure that tools like the VisIt visualization application can provide in-situ data analysis and post-processing for simulations on peta-scale machines. We modified a version of VisIt to study load-balancing trade-offs between light-weight kernel compute environments and dedicated post-processing cluster nodes. Our research focused on memory overheads for contouring operations, which involves variable amounts of generated geometry on each node and computation of normal vectors for all generated vertices. Each compute node independently decided whether to send data to dedicated post-processing nodes at each stage of pipeline execution, depending on available memory. We instrumented the code to allow user settable available memory amounts to test extremely low-overhead compute environments. We performed initial testing of this prototype distributed streaming framework, but did not have time to perform scaling studies at and beyond 1000 compute-nodes.

  15. Design and Analysis of a Scalable In-situ Cryogen Production Facility for Space Exploration

    NASA Astrophysics Data System (ADS)

    Petrick, D. E.; Nieczkoski, S. J.; Duke, M. B.; Gardner, T. Q.

    2006-04-01

    A system demonstration of a scalable cryogen production facility will be necessary to establish the feasibility of in-situ resource utilization (ISRU) as part of NASA's Space Exploration Initiative. Cryogenic fluids such as liquid oxygen, hydrogen, and methane will be required for propellants for return vehicle propulsion, life support consumables, power generation, and precursors for the refinement of structural materials. A key technology necessary for the realization of a cryogenic ISRU system is high-efficiency cryocoolers that can enable low-temperature thermal processing of extracted volatile materials for separation, liquefaction, and zero boiloff (ZBO) storage. This paper addresses the design and analysis of the following pertinent technologies: (1) producing a concentrated feedstock from low partial-pressure volatile constituents to drive chemical and thermal reaction operations, (2) balancing unit feed and effluent flows and molecular species to derive system efficiency and capture of high-purity cryogenic fluids, (3) thermal isolation of cryogenically cooled stages from ambient and elevated temperature subsystems to achieve power efficiency and thermal stability, and (4) developing a reverse-Brayton cycle cryocooler that provides cooling at 20 K for liquefying and sustaining hydrogen storage.

  16. Summary and analysis of 216 GHz polarimetric measurements of in-situ rain

    NASA Astrophysics Data System (ADS)

    Hedden, Abigail S.; Wikner, David A.; Bradley, Russell W.

    2015-05-01

    The Army Research Laboratory (ARL) has developed a polarimetric frequency-modulated continuous-wave (FMCW) instrumentation radar that has been used to study the polarization and backscatter properties of in-situ rain in the 220 GHz atmospheric window. A summary of the preliminary measurements is presented in this work including an analysis of the co-polarization backscatter and attenuation characteristics measured at 216 GHz. A marginal detection of the copolarization backscatter signature of rain was made during a series of fast-moving, heavy downpour thunderstorm events. A detection limit of -40±3 dB[m2/m3] was found for the VV-polarization cross section per unit volume for rain rates up to 150 mm/hr. Co-polarization (VV- and HH-polarization) attenuation characteristics measured at high rain rates (< 20 mm/hr) were well described by a Joss thunderstorm drop distribution in the high frequency limit, where drop size is much greater than the observation wavelength. Observations at 216 GHz suggest attenuation levels of 8-10 dB/km at rain rates above 20 mm/hr, strengthening previous evidence that attenuation through rain is independent of frequency under high rain rate conditions. Attenuation measurements at lower rain rates (< 20 mm/hr) were qualitatively consistent with both Laws and Parsons and Joss thunderstorm distributions.

  17. Fundamental study of spin-coating using in-situ analysis and simulation

    NASA Astrophysics Data System (ADS)

    Harumoto, Masahiko; Yoshida, Jun-ichi; Stokes, Harold; Tanaka, Yuji; Miyagi, Tadashi; Kaneyama, Koji; Pieczulewski, Charles; Asai, Masaya

    2015-03-01

    Spin coating has been used as a photoresist application method for many years, and consequently certain defects have been recognized through each resist generation; i-line, KrF, ArF, ArF immersion and, most recently, EUV. Last year we reported an in-situ analysis via high-speed video camera that proved to be useful for understanding defect formation such as non-uniformity spots within organic film coatings and post-develop water-mark defects. In this study, fingerprints known as `tiger stripes' around the wafer's edge were analyzed. This phenomenon, for example, is directly related to the wafer spin-speed and air-flow during the coat-processing. Utilizing a high-speed camera and 3D simulation, we reveal the mechanism of fingerprint generation for tiger stripe phenomena, confirm the mechanism with several different spin-speeds, and correlate these to defect inspection results. Furthermore, we will discuss the expansion to 450mmm wafers.

  18. Quantitative analysis of microRNAs in tissue microarrays by in situ hybridization

    PubMed Central

    Hanna, Jason A.; Wimberly, Hallie; Kumar, Salil; Slack, Frank; Agarwal, Seema; Rimm, David L.

    2013-01-01

    MicroRNAs (miRNAs) have emerged as key regulators in the pathogenesis of cancers where they can act as either oncogenes or tumor suppressors. Most miRNA measurement methods require total RNA extracts which lack critical spatial information and present challenges for standardization. We have developed and validated a method for the quantitative analysis of miRNA expression by in situ hybridization (ISH) allowing for the direct assessment of tumor epithelial expression of miRNAs. This co-localization based approach (called qISH) utilizes DAPI and cytokeratin immunofluorescence to establish subcellular compartments in the tumor epithelia, then multiplexed with the miRNA ISH, allows for quantitative measurement of miRNA expression within these compartments. We use this approach to assess miR-21, miR-92a, miR-34a, and miR-221 expression in 473 breast cancer specimens on tissue microarrays. We found that miR-221 levels are prognostic in breast cancer illustrating the high-throughput method and confirming that miRNAs can be valuable biomarkers in cancer. Furthermore, in applying this method we found that the inverse relationship between miRNAs and proposed target proteins is difficult to discern in large population cohorts. Our method demonstrates an approach for large cohort, tissue microarray-based assessment of miRNA expression. PMID:22482439

  19. In situ microparticle analysis of marine phytoplankton cells with infrared laser-based optical tweezers

    NASA Astrophysics Data System (ADS)

    Sonek, G. J.; Liu, Y.; Iturriaga, R. H.

    1995-11-01

    We describe the application of infrared optical tweezers to the in situ microparticle analysis of marine phytoplankton cells. A Nd:YAG laser (lambda=3D 1064 nm) trap is used to confine and manipulate single Nannochloris and Synechococcus cells in an enriched seawater medium while spectral fluorescence and Lorenz-Mie backscatter signals are simultaneously acquired under a variety of excitation and trapping conditions. Variations in the measured fluorescence intensities of chlorophyll a (Chl a) and phycoerythrin pigments in phytoplankton cells are observed. These variations are related, in part, to basic intrasample variability, but they also indicate that increasing ultraviolet-exposure time and infrared trapping power may have short-term effects on cellular physiology that are related to Chl a photobleaching and laser-induced heating, respectively. The use of optical tweezers to study the factors that affect marine cell physiology and the processes of absorption, scattering, and attenuation by individual cells, organisms, and particulate matter that contribute to optical closure on a microscopic scale are also described. (c)1995 Optical Society of America

  20. In situ fluidization for peat bed rupture, and preliminary economic analysis

    NASA Astrophysics Data System (ADS)

    Niven, R. K.; Khalili, N.

    2002-11-01

    This study concerns in situ fluidization (ISF), a new remediation method with potential application to the remediation of NAPL and heavy metal contaminants, by their release from the fluidized zone generated by a water jet. The present study examines the effect of ISF on layers of peat, of significance owing to its role as an important NAPL and metal contaminant trap. Once trapped, such contaminants are not readily accessible by most remedial methods, due to the low permeability and diffusivity of the peat. A simple tank experiment is used to demonstrate rupture of a peat layer by ISF, with removal of the peat as elutriated fines and segregated peat chunks. The application of ISF in the field is then examined by three field trials in uncontaminated sands, in both saturated and unsaturated conditions. Fluidized depths of up to 1.9 m in the saturated zone (with refusal on a peat layer) and 2.5 m in the unsaturated zone (no refusal) were attained, using a 1.9-m-long, 50 mm diameter jet operated at 5-13 l s -1. Pulses of dark turbidity and shell fragments in the effluent indicated the rupture of peat and shelly layers. The experiments demonstrate the hydraulic viability of ISF in the field, and its ability to remove peat-based contaminants. The issues of appropriate jet design and water generation during ISF are discussed, followed by a preliminary economic analysis of ISF relative to existing remediation methods.

  1. Analysis of thiols by microchip capillary electrophoresis for in situ planetary investigations.

    PubMed

    Mora, Maria F; Stockton, Amanda M; Willis, Peter A

    2013-01-01

    The detection of thiols on extraterrestrial bodies could provide evidence for life, as well as a host of potential prebiological or abiological processes. Here, we report a novel protocol to analyze organic thiols by microchip CE with LIF detection. Thiols were labeled with Pacific Blue C5 maleimide and analyzed by MEKC. The separation buffer consisted of 15 mM tetraborate pH 9.2 and 25 mM SDS. The optimized method provided LODs ranging from 1.4 to 15 nM. The method was validated using samples collected from geothermal pools at Hot Creek Gorge, California, which were found to contain 2-propanethiol and 1-butanethiol in the nanomolar concentration range. These samples serve as chemical analogues to material potentially present in the reducing environment of primitive Earth and also at sulfurous regions of Mars. Hence, the protocol developed here enables highly sensitive thiol analysis in samples with complexity comparable to that expected in astrobiologically relevant extraterrestrial settings. This new protocol could be readily added to the existing suite of microfluidic chemical analyses developed for in situ planetary exploration; all that is required is the incorporation of two new reagents to the payload of an existing instrument concept. PMID:23161601

  2. The murine ufo receptor: molecular cloning, chromosomal localization and in situ expression analysis.

    PubMed

    Faust, M; Ebensperger, C; Schulz, A S; Schleithoff, L; Hameister, H; Bartram, C R; Janssen, J W

    1992-07-01

    We have cloned the mouse homologue of the ufo oncogene. It encodes a novel tyrosine kinase receptor characterized by a unique extracellular domain containing two immunoglobulin-like and two fibronectin type III repeats. Comparison of the predicted ufo amino acid sequences of mouse and man revealed an overall identity of 87.6%. The ufo locus maps to mouse chromosome 7A3-B1 and thereby extends the known conserved linkage group between mouse chromosome 7 and human chromosome 19. RNA in situ hybridization analysis established the onset of specific ufo expression in the late embryogenesis at day 12.5 post coitum (p.c.) and localized ufo transcription to distinct substructures of a broad spectrum of developing tissues (e.g. subepidermal cells of the skin, mesenchymal cells of the periosteum). In adult animals ufo is expressed in cells forming organ capsules as well as in connective tissue structures. ufo may function as a signal transducer between specific cell types of mesodermal origin.

  3. Field and numerical analysis of in-situ air sparging: a case study.

    PubMed

    Benner, M L; Stanford, S M; Lee, L S; Mohtar, R H

    2000-02-25

    An in-situ air sparging operation was used to remediate the sandy subsurface soils and shallow groundwater under a drum storage site near Chicago, IL, where either periodic or random spillage of a light non-aqueous phase liquid (LNAPL) occurred between 1980 and 1987. Both field measurements and model simulations using commercially available computer software suggested that microbial degradation was the most significant contributor to the removal of contaminant mass. Toluene, ethylbenzene and total xylenes (TEX), which were of major concern with regards to reaching clean-up criteria at the site, were observed to decline by 88% in concentration. Furthermore, up to 97% of the total mass removed through microbial degradation consisted of TEX. Of the total contaminant spill, up to 23% of initial organic chemical mass was removed through microbial degradation compared to less than 6% by physical stripping. Greater loss to microbial degradation is most likely attributed to the relatively low air injection rate used during the course of the air sparging remediation. Evaluation of air sparging at the site using model simulations supported this analysis by estimating 140 and 620 kg of total contaminant mass being removed through volatilization and biodegradation, respectively. An evaluation of several system design parameters using model simulations suggested that only the type of sparging operation (i.e. pulsed or continuous) was significant in terms of total contaminant removal time, while both the sparging operation and air injection rate were significant in terms of removal of a critical species, total xylenes.

  4. Field applicability of Compound-Specific Isotope Analysis (CSIA) for characterization and quantification of in situ contaminant degradation in aquifers.

    PubMed

    Braeckevelt, M; Fischer, A; Kästner, M

    2012-06-01

    Microbial processes govern the fate of organic contaminants in aquifers to a major extent. Therefore, the evaluation of in situ biodegradation is essential for the implementation of Natural Attenuation (NA) concepts in groundwater management. Laboratory degradation experiments and biogeochemical approaches are often biased and provide only indirect evidence of in situ degradation potential. Compound-Specific Isotope Analysis (CSIA) is at present among the most promising tools for assessment of the in situ contaminant degradation within aquifers. One- and two-dimensional (2D) CSIA provides qualitative and quantitative information on in situ contaminant transformation; it is applicable for proving in situ degradation and characterizing degradation conditions and reaction mechanisms. However, field application of CSIA is challenging due to a number of influencing factors, namely those affecting the observed isotope fractionation during biodegradation (e.g., non-isotope-fractionating rate-limiting steps, limited bioavailability), potential isotope effects caused by processes other than biodegradation (e.g., sorption, volatilization, diffusion), as well as non-isotope-fractionating physical processes such as dispersion and dilution. This mini-review aims at guiding practical users towards the sound interpretation of CSIA field data for the characterization of in situ contaminant degradation. It focuses on the relevance of various constraints and influencing factors in CSIA field applications and provides advice on when and how to account for these constraints. We first evaluate factors that can influence isotope fractionation during biodegradation, as well as potential isotope-fractionating and non-isotope-fractionating physical processes governing observed isotope fractionation in the field. Finally, the potentials of the CSIA approach for site characterization and the proper ways to account for various constraints are illustrated by means of a comprehensive CSIA field

  5. In Situ Monitoring of Crystal Growth Using MEPHISTO, Mission STS 87-Program USMP-4: Experimental Analysis

    NASA Technical Reports Server (NTRS)

    Abbaschian, Reza; Chen, F.; Mileham, J. R.; deGroh, H., III; Timchenko, V.; Leonardi, E.; deVahlDavis, G.; Coriell, S.; Cambon, G.

    1999-01-01

    This report summarizes the results of the In situ Monitoring of Crystal Growth Using MEPHISTO (Material por l'Etude des Phenomenes Interessant de la Solidification sur Terre et en Orbite) experiment on USMP-4. The report includes microstructural and compositional data obtained during the first year of the post flight analysis, as well as numerical simulation of the flight experiment. Additional analyses are being continued and will be reported in the near future. The experiments utilized MEPHISTO hardware to study the solidification and melting behavior of bismuth alloyed with 1 at% tin. The experiments involved repeated melting and solidification of three samples, each approximately 90 cm long and 6mm in diameter. Half of each sample also included a 2 mm. diameter growth capillary, to assist in the formation of single grain inside. One sample provided the Seebeck voltage generated during melting and freezing processes. Another one provided temperature data and Peltier pulsed demarcation of the interface shape for post flight analysis. The third sample provided resistance and velocity measurements, as well as additional thermal data. The third sample was also quenched at the end of the mission to preserve the interface composition for post flight determination. A total of more than 45cm of directionally solidified alloy were directionally solidified at the end of the flight for post mission structural and compositional characterization. Metallurgical analysis of the samples has shown that the interfacial kinetics play a key role in controlling the morphological stability of faceted alloys. Substantial differences were observed in the Seebeck signal between the ground-based experiments and the space-based experiments. The temperature gradient in the liquid for the ground-based experiments was also significantly lower than the temperature gradient in the liquid for the space-based experiments. Both of these observations indicate significant influence of liquid

  6. Fully integrated wearable sensor arrays for multiplexed in situ perspiration analysis.

    PubMed

    Gao, Wei; Emaminejad, Sam; Nyein, Hnin Yin Yin; Challa, Samyuktha; Chen, Kevin; Peck, Austin; Fahad, Hossain M; Ota, Hiroki; Shiraki, Hiroshi; Kiriya, Daisuke; Lien, Der-Hsien; Brooks, George A; Davis, Ronald W; Javey, Ali

    2016-01-28

    Wearable sensor technologies are essential to the realization of personalized medicine through continuously monitoring an individual's state of health. Sampling human sweat, which is rich in physiological information, could enable non-invasive monitoring. Previously reported sweat-based and other non-invasive biosensors either can only monitor a single analyte at a time or lack on-site signal processing circuitry and sensor calibration mechanisms for accurate analysis of the physiological state. Given the complexity of sweat secretion, simultaneous and multiplexed screening of target biomarkers is critical and requires full system integration to ensure the accuracy of measurements. Here we present a mechanically flexible and fully integrated (that is, no external analysis is needed) sensor array for multiplexed in situ perspiration analysis, which simultaneously and selectively measures sweat metabolites (such as glucose and lactate) and electrolytes (such as sodium and potassium ions), as well as the skin temperature (to calibrate the response of the sensors). Our work bridges the technological gap between signal transduction, conditioning (amplification and filtering), processing and wireless transmission in wearable biosensors by merging plastic-based sensors that interface with the skin with silicon integrated circuits consolidated on a flexible circuit board for complex signal processing. This application could not have been realized using either of these technologies alone owing to their respective inherent limitations. The wearable system is used to measure the detailed sweat profile of human subjects engaged in prolonged indoor and outdoor physical activities, and to make a real-time assessment of the physiological state of the subjects. This platform enables a wide range of personalized diagnostic and physiological monitoring applications.

  7. Fully integrated wearable sensor arrays for multiplexed in situ perspiration analysis

    NASA Astrophysics Data System (ADS)

    Gao, Wei; Emaminejad, Sam; Nyein, Hnin Yin Yin; Challa, Samyuktha; Chen, Kevin; Peck, Austin; Fahad, Hossain M.; Ota, Hiroki; Shiraki, Hiroshi; Kiriya, Daisuke; Lien, Der-Hsien; Brooks, George A.; Davis, Ronald W.; Javey, Ali

    2016-01-01

    Wearable sensor technologies are essential to the realization of personalized medicine through continuously monitoring an individual’s state of health. Sampling human sweat, which is rich in physiological information, could enable non-invasive monitoring. Previously reported sweat-based and other non-invasive biosensors either can only monitor a single analyte at a time or lack on-site signal processing circuitry and sensor calibration mechanisms for accurate analysis of the physiological state. Given the complexity of sweat secretion, simultaneous and multiplexed screening of target biomarkers is critical and requires full system integration to ensure the accuracy of measurements. Here we present a mechanically flexible and fully integrated (that is, no external analysis is needed) sensor array for multiplexed in situ perspiration analysis, which simultaneously and selectively measures sweat metabolites (such as glucose and lactate) and electrolytes (such as sodium and potassium ions), as well as the skin temperature (to calibrate the response of the sensors). Our work bridges the technological gap between signal transduction, conditioning (amplification and filtering), processing and wireless transmission in wearable biosensors by merging plastic-based sensors that interface with the skin with silicon integrated circuits consolidated on a flexible circuit board for complex signal processing. This application could not have been realized using either of these technologies alone owing to their respective inherent limitations. The wearable system is used to measure the detailed sweat profile of human subjects engaged in prolonged indoor and outdoor physical activities, and to make a real-time assessment of the physiological state of the subjects. This platform enables a wide range of personalized diagnostic and physiological monitoring applications.

  8. Fully integrated wearable sensor arrays for multiplexed in situ perspiration analysis.

    PubMed

    Gao, Wei; Emaminejad, Sam; Nyein, Hnin Yin Yin; Challa, Samyuktha; Chen, Kevin; Peck, Austin; Fahad, Hossain M; Ota, Hiroki; Shiraki, Hiroshi; Kiriya, Daisuke; Lien, Der-Hsien; Brooks, George A; Davis, Ronald W; Javey, Ali

    2016-01-28

    Wearable sensor technologies are essential to the realization of personalized medicine through continuously monitoring an individual's state of health. Sampling human sweat, which is rich in physiological information, could enable non-invasive monitoring. Previously reported sweat-based and other non-invasive biosensors either can only monitor a single analyte at a time or lack on-site signal processing circuitry and sensor calibration mechanisms for accurate analysis of the physiological state. Given the complexity of sweat secretion, simultaneous and multiplexed screening of target biomarkers is critical and requires full system integration to ensure the accuracy of measurements. Here we present a mechanically flexible and fully integrated (that is, no external analysis is needed) sensor array for multiplexed in situ perspiration analysis, which simultaneously and selectively measures sweat metabolites (such as glucose and lactate) and electrolytes (such as sodium and potassium ions), as well as the skin temperature (to calibrate the response of the sensors). Our work bridges the technological gap between signal transduction, conditioning (amplification and filtering), processing and wireless transmission in wearable biosensors by merging plastic-based sensors that interface with the skin with silicon integrated circuits consolidated on a flexible circuit board for complex signal processing. This application could not have been realized using either of these technologies alone owing to their respective inherent limitations. The wearable system is used to measure the detailed sweat profile of human subjects engaged in prolonged indoor and outdoor physical activities, and to make a real-time assessment of the physiological state of the subjects. This platform enables a wide range of personalized diagnostic and physiological monitoring applications. PMID:26819044

  9. Unravelling organic matter and nutrient biogeochemistry in groundwater-fed rivers under baseflow conditions: controls on in situ analysis

    NASA Astrophysics Data System (ADS)

    Bieroza, M.; Heathwaite, A. L.

    2015-12-01

    In agricultural catchments diffuse fluxes of nutrients, mainly nitrogen (N) and phosphorus (P) from arable land and livestock are responsible for pollution of receiving waters and their eutrophication. Organic matter (OM) can play an important role in mediating a range of biogeochemical processes controlling diffuse pollution in streams and at their interface with surrounding land in the riparian and hyporheic zones. Thus, a holistic and simultaneous monitoring of N, P and OM fractions can help to improve our understanding of biogeochemical functioning of agricultural streams. In this study we build on intensive in situ monitoring of diffuse pollution in a small agricultural groundwater-fed stream in NW England carried out since 2009. We examine the variation in baseflow macronutrient and organic matter concentrations determined by automatic in situ (wet chemistry analyser, UV-Vis and fluorescence sensors) and automated grab sampling without instantaneous analysis using autosamplers. We evaluate and compare the performance of the automatic sampling techniques and their ability to capture typically low baseflow concentrations of highly reactive forms of nutrients and organic matter: total reactive phosphorus, nitrate nitrogen and tryptophan-like fluorescence which is an autochthonous fraction of OM. In particular, we examine the temperature effects on in situ automatic nutrient and organic matter determinations and autosampler storage effects for hourly samples retrieved daily for laboratory analyses. Understanding transformations and measurement variability in reactive forms of nutrients and organic matter associated with in situ analysis is of great importance for establishing robust monitoring protocols and creating future monitoring networks.

  10. Systematic analysis of the in situ crosstalk of tyrosine modifications reveals no additional natural selection on multiply modified residues

    PubMed Central

    Pan, Zhicheng; Liu, Zexian; Cheng, Han; Wang, Yongbo; Gao, Tianshun; Ullah, Shahid; Ren, Jian; Xue, Yu

    2014-01-01

    Recent studies have indicated that different post-translational modifications (PTMs) synergistically orchestrate specific biological processes by crosstalks. However, the preference of the crosstalk among different PTMs and the evolutionary constraint on the PTM crosstalk need further dissections. In this study, the in situ crosstalk at the same positions among three tyrosine PTMs including sulfation, nitration and phosphorylation were systematically analyzed. The experimentally identified sulfation, nitration and phosphorylation sites were collected and integrated with reliable predictions to perform large-scale analyses of in situ crosstalks. From the results, we observed that the in situ crosstalk between sulfation and nitration is significantly under-represented, whereas both sulfation and nitration prefer to co-occupy with phosphorylation at same tyrosines. Further analyses suggested that sulfation and nitration preferentially co-occur with phosphorylation at specific positions in proteins, and participate in distinct biological processes and functions. More interestingly, the long-term evolutionary analysis indicated that multi-PTM targeting tyrosines didn't show any higher conservation than singly modified ones. Also, the analysis of human genetic variations demonstrated that there is no additional functional constraint on inherited disease, cancer or rare mutations of multiply modified tyrosines. Taken together, our systematic analyses provided a better understanding of the in situ crosstalk among PTMs. PMID:25476580

  11. Geostatistical Analysis of Surface Temperature and In-Situ Soil Moisture Using LST Time-Series from Modis

    NASA Astrophysics Data System (ADS)

    Sohrabinia, M.; Rack, W.; Zawar-Reza, P.

    2012-07-01

    The objective of this analysis is to provide a quantitative estimate of the fluctuations of land surface temperature (LST) with varying near surface soil moisture (SM) on different land-cover (LC) types. The study area is located in the Canterbury Plains in the South Island of New Zealand. Time series of LST from the MODerate resolution Imaging Spectro-radiometer (MODIS) have been analysed statistically to study the relationship between the surface skin temperature and near-surface SM. In-situ measurements of the skin temperature and surface SM with a quasi-experimental design over multiple LC types are used for validation. Correlations between MODIS LST and in-situ SM, as well as in-situ surface temperature and SM are calculated. The in-situ measurements and MODIS data are collected from various LC types. Pearson's r correlation coefficient and linear regression are used to fit the MODIS LST and surface skin temperature with near-surface SM. There was no significant correlation between time-series of MODIS LST and near-surface SM from the initial analysis, however, careful analysis of the data showed significant correlation between the two parameters. Night-time series of the in-situ surface temperature and SM from a 12 hour period over Irrigated-Crop, Mixed-Grass, Forest, Barren and Open- Grass showed inverse correlations of -0.47, -0.68, -0.74, -0.88 and -0.93, respectively. These results indicated that the relationship between near-surface SM and LST in short-terms (12 to 24 hours) is strong, however, remotely sensed LST with higher temporal resolution is required to establish this relationship in such time-scales. This method can be used to study near-surface SM using more frequent LST observations from a geostationary satellite over the study area.

  12. Perchlorate and volatiles of the brine of Lake Vida (Antarctica): Implication for the in situ analysis of Mars sediments

    NASA Astrophysics Data System (ADS)

    Kenig, Fabien; Chou, Luoth; McKay, Christopher P.; Jackson, W. Andrew; Doran, Peter T.; Murray, Alison E.; Fritsen, Christian H.

    2016-07-01

    The cold (-13.4°C), cryoencapsulated, anoxic, interstitial brine of the >27 m thick ice of Lake Vida (Victoria Valley, Antarctica) contains 49 µg · L-1 of perchlorate and 11 µg · L-1 of chlorate. Lake Vida brine (LVBr) may provide an analog for potential oxychlorine-rich subsurface brine on Mars. LVBr volatiles were analyzed by solid-phase microextraction (SPME) gas chromatography-mass spectrometry (GC-MS) with two different SPME fibers. With the exception of volatile organic sulfur compounds, most other volatiles observed were artifacts produced in the GC injector when the thermal decomposition products of oxychlorines reacted with reduced carbon derived from LVBr and the SPME fiber phases. Analysis of MilliQ water with perchlorate (40 µg · L-1) showed low level of organic artifacts, reflecting carbon limitation. In order to observe sample-derived organic compounds, both in analog samples and on Mars, the molar abundance of reduced carbon in a sample must exceed those of O2 and Cl2 produced during decomposition of oxychlorines. This suggests that the abundance of compounds observed by the Sample Analysis at Mars (SAM) instruments in Sheepbed samples (CB-3, CB5, and CB6) may be controlled by an increase in the reduced-carbon/oxychlorine ratio of these samples. To increase chances of in situ detection of Martian organics during pyrolysis-GC-MS, we propose that the derivatization agents stored on SAM may be used as an external source of reduced carbon, increasing artificially the reduced-carbon to perchlorate ratio during pyrolysis, allowing the expression of more abundant and perhaps more diverse Martian organic matter.

  13. Perchlorate and Volatiles of the Brine of Lake Vida (Antarctica): Implication for the in Situ Analysis of Mars Sediments

    NASA Technical Reports Server (NTRS)

    Kenig, Fabien; Chou, Luoth; McKay, Christopher P.; Jackson, W. Andrew; Doran, Peter T.; Murray, Alison E.; Fritsen, Christian H.

    2016-01-01

    The cold (-13.4 C), cryoencapsulated, anoxic, interstitial brine of the 27 m-thick ice of Lake Vida (Victoria Valley, Antarctica) contains 49 microgram L-1 of perchlorate and 11 microgram L-1 of chlorate. Lake Vida brine (LVBr) may provide an analog for potential oxychlorine-rich subsurface brine on Mars. LVBr volatiles were analyzed by solid-phase microextraction (SPME) gas chromatography-mass spectrometry (GC-MS) with two different SPME fibers. With the exception of volatile organic sulfur compounds, most other volatiles observed were artifacts produced in the GC injector when the thermal decomposition products of oxychlorines reacted with reduced carbon derived from LVBr and the SPME fiber phases. Analysis of MilliQ water with perchlorate (40 microgram L-1) showed low level of organic artifacts, reflecting carbon limitation. In order to observe sample-derived organic compounds, both in analog samples and on Mars, the molar abundance of reduced carbon in a sample must exceed those of O2 and Cl2 produced during decomposition of oxychlorines. This suggests that the abundance of compounds observed by the Sample Analysis at Mars (SAM) instruments in Sheepbed samples (CB-3, CB5, and CB6) may be controlled by an increase in the reduced-carbon/oxychlorine ratio of these samples. To increase chances of in situ detection of Martian organics during pyrolysis-GC-MS, we propose that the derivatization agents stored on SAM may be used as an external source of reduced carbon, increasing artificially the reduced-carbon to perchlorate ratio during pyrolysis, allowing the expression of more abundant and perhaps more diverse Martian organic matter.

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

    NASA Technical Reports Server (NTRS)

    Holland, P.; Chutjian, A.; Darrach, M.; Orient, O.

    2002-01-01

    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 compounds in complex mixtures of gases, such as those found in the International Space Station's cabin atmosphere. Our design approach utilizes micro gas chromatography components coupled with either a miniature quadrupole mass spectrometer array (QMSA) or compact, high-resolution Paul ion trap.

  15. In situ measurement of methane fluxes and analysis of transcribed particulate methane monooxygenase in desert soils.

    PubMed

    Angel, Roey; Conrad, Ralf

    2009-10-01

    Aerated soils are a biological sink for atmospheric methane. However, the activity of desert soils and the presence of methanotrophs in these soils have hardly been studied. We studied on-site atmospheric methane consumption rates as well as the diversity and expression of the pmoA gene, coding for a subunit of the particulate methane monooxygenase, in arid and hyperarid soils in the Negev Desert, Israel. Methane uptake was only detected in undisturbed soils in the arid region (approximately 90 mm year(-1)) and vertical methane profiles in soil showed the active layer to be at 0-20 cm depth. No methane uptake was detected in the hyperarid soils (approximately 20 mm year(-1)) as well as in disturbed soils in the arid region (i.e. agricultural field and a mini-catchment). Molecular analysis of the methanotrophic community using terminal restriction fragment length polymorphism (T-RFLP) and cloning/sequencing of the pmoA gene detected methanotrophs in the active soils, whereas the inactive ones were dominated by sequences of the homologous gene amoA, coding for a subunit of the ammonia monooxygenase. Even in the active soils, methanotrophs (as well as in situ activity) could not be detected in the soil crust, which is the biologically most important layer in desert soils. All pmoA sequences belonged to yet uncultured strains. Transcript analysis showed dominance of sequences clustering within the JR3, formerly identified in Californian grassland soils. Our results show that although active methanotrophs are prevalent in arid soils they seem to be absent or inactive in hyperarid and disturbed arid soils. Furthermore, we postulate that methanotrophs of the yet uncultured JR3 cluster are the dominant atmospheric methane oxidizers in this ecosystem.

  16. Microthermogravimetric analysis as a useful tool for in-situ planetary space missions

    NASA Astrophysics Data System (ADS)

    Palomba, E.; Zinzi, A.; Longobardo, A.; Bellucci, G.; Zampetti, E.; Pantalei, S.; Bearzotti, A.; Macagnano, A.

    2008-09-01

    Thermo gravimetric analysis (TGA) is a widely used technique to investigate condensation/sublimation and absorption/desorption processes of volatile compounds in different environments. TGA analyzers are used to investigate outgassing contamination in Space, dehydration and organic decomposition in minerals, as well as to measure moisture content in foods or develop temperature profiles for firing ceramics. TGA is often coupled with other analytical techniques (e.g., mass spectroscopy and FTIR) in order to determine the specific off-gas materials.

  17. Analysis of pollutant chemistry in combustion by in situ pulsed photoacoustic laser diagnostics

    NASA Astrophysics Data System (ADS)

    Stenberg, Jari; Hernberg, Rolf; Vattulainen, Juha

    1995-12-01

    A technique for gas analysis based on pulsed-laser-induced photoacoustic spectroscopy in the UV and the visible is presented. The laser-based technique and the associated analysis probe have been developed for the analysis of pollutant chemistry in fluidized beds and other combustion environments with limited or no optical access. The photoacoustic-absorption spectrum of the analyzed gas is measured in a test cell located at the end of a tubular probe. This test cell is subject to the prevailing temperature and pressure in the combustion process. The instrument response has been calibrated for N2O, NO, NO2, NH3, SO2, and H2 S at atmospheric pressure between 20 and 910 deg C. The response of the probe was found to increase with pressure for N2O, NO, NH 3, and NO2 up to 1.2 MPa pressure. The method and the probe have been used for detection and ranging of gas concentrations in a premixed methane flame. Some preliminary tests in a large 12-MW circulating bed boiler have also been done.

  18. Technical Note: In-situ derivatization thermal desorption GC-TOFMS for direct analysis of particle-bound non-polar and polar organic species

    NASA Astrophysics Data System (ADS)

    Orasche, J.; Schnelle-Kreis, J.; Abbaszade, G.; Zimmermann, R.

    2011-09-01

    An in-situ derivatization thermal desorption method followed by gas chromatography and time-of-flight mass spectrometry (IDTD-GC-TOFMS) was developed for determination of polar organic compounds together with non-polar compounds in one measurement. Hydroxyl and carboxyl groups of compounds such as anhydrous sugars, alcohols and phenols, fatty acids and resin acids are targets of the derivatization procedure. Derivatization is based on silylation with N-Methyl-N-trimethylsilyl-trifluoroacetamide (MSTFA) during the step of thermal desorption. The high temperature of 300 °C during desorption is utilized for the in-situ derivatization on the collection substrate (quartz fibre filters) accelerating the reaction rate. Thereby, the analysis time is as short as without derivatization. At first the filter surface is dampened with derivatization reagent before insertion of the sample into the thermal desorption unit. To ensure ongoing derivatization during thermal desorption the carrier gas is enriched with MSTFA until the desorption procedure is finished. The precisions of all studied analytes were below 17 % within a calibration range from 22 pg (abietic acid) up to 342 ng (levoglucosan). Limits of quantification (LOQ) for polycyclic aromatic hydrocarbons (PAH) were between 1 pg (fluoranthene) and 8 pg (indeno[1,2,3-cd]pyrene), for resin acids 37-102 pg and for studied phenols 4-144 pg. LOQ for levoglucosan was 17 pg.

  19. Techno-economic and uncertainty analysis of in situ and ex situ fast pyrolysis for biofuel production

    SciTech Connect

    Li, Boyan; Ou, Longwen; Dang, Qi; Meyer, Pimphan A.; Jones, Susanne B.; Brown, Robert C.; Wright, Mark

    2015-11-01

    This study evaluates the techno-economic uncertainty in cost estimates for two emerging biorefinery technologies for biofuel production: in situ and ex situ catalytic pyrolysis. Stochastic simulations based on process and economic parameter distributions are applied to calculate biorefinery performance and production costs. The probability distributions for the minimum fuel-selling price (MFSP) indicate that in situ catalytic pyrolysis has an expected MFSP of $4.20 per gallon with a standard deviation of 1.15, while the ex situ catalytic pyrolysis has a similar MFSP with a smaller deviation ($4.27 per gallon and 0.79 respectively). These results suggest that a biorefinery based on ex situ catalytic pyrolysis could have a lower techno-economic risk than in situ pyrolysis despite a slightly higher MFSP cost estimate. Analysis of how each parameter affects the NPV indicates that internal rate of return, feedstock price, total project investment, electricity price, biochar yield and bio-oil yield are significant parameters which have substantial impact on the MFSP for both in situ and ex situ catalytic pyrolysis.

  20. In situ atomic force microscopy analysis of morphology and particle size changes in lithium iron phosphate cathode during discharge.

    PubMed

    Demirocak, Dervis Emre; Bhushan, Bharat

    2014-06-01

    Li-ion batteries offer great promise for future plug-in hybrid electric vehicles (PHEVs) and pure electric vehicles (EVs). One of the challenges is to improve the cycle life of Li-ion batteries which requires detailed understanding of the aging phenomenon. In situ techniques are especially valuable to understand aging since it allows monitoring the physical and chemical changes in real time. In this study, in situ atomic force microscopy (AFM) is utilized to study the changes in morphology and particle size of LiFePO4 cathode during discharge. The guidelines for in situ AFM cell design for accurate and reliable measurements based on different designs are presented. The effect of working electrode to counter electrode surface area ratio on cycling data of an in situ cell is also discussed. Analysis of the surface area change in LiFePO4 particles when the cell was cycled between 100% and 70% state of charge is presented. Among four particles analyzed, surface area increase of particles during Li intercalation of LiFePO4 spanned from 1.8% to 14.3% indicating the inhomogeneous nature of the cathode surface.

  1. Large-Scale Compute-Intensive Analysis via a Combined In-situ and Co-scheduling Workflow Approach

    SciTech Connect

    Messer, Bronson; Sewell, Christopher; Heitmann, Katrin; Finkel, Dr. Hal J; Fasel, Patricia; Zagaris, George; Pope, Adrian; Habib, Salman; Parete-Koon, Suzanne T

    2015-01-01

    Large-scale simulations can produce tens of terabytes of data per analysis cycle, complicating and limiting the efficiency of workflows. Traditionally, outputs are stored on the file system and analyzed in post-processing. With the rapidly increasing size and complexity of simulations, this approach faces an uncertain future. Trending techniques consist of performing the analysis in situ, utilizing the same resources as the simulation, and/or off-loading subsets of the data to a compute-intensive analysis system. We introduce an analysis framework developed for HACC, a cosmological N-body code, that uses both in situ and co-scheduling approaches for handling Petabyte-size outputs. An initial in situ step is used to reduce the amount of data to be analyzed, and to separate out the data-intensive tasks handled off-line. The analysis routines are implemented using the PISTON/VTK-m framework, allowing a single implementation of an algorithm that simultaneously targets a variety of GPU, multi-core, and many-core architectures.

  2. Simulated In Situ Measurements and Structural Analysis of Reconnection-Driven Solar Polar Jets

    NASA Astrophysics Data System (ADS)

    Roberts, Merrill A.; Uritsky, Vadim M.; Karpen, Judith T.; DeVore, C. R.

    2015-04-01

    Solar polar jets are observed to originate in regions within the open field of solar coronal holes. These so called “anemone” regions are associated with an embedded dipole topology, consisting of a fan-separatrix and a spine line emanating from a null point occurring at the top of the dome shaped fan surface (Antiochos 1998). In this study, we analyze simulations using the Adaptively Refined MHD Solver (ARMS) that take into account gravity, solar wind, and spherical geometry to generate polar jets by reconnection between a twisted embedded bipole and the surrounding open field (Karpen et al. 2015). These new simulations confirm and extend previous Cartesian studies of polar jets based on this mechanism (Pariat et al. 2009, 2010, 2015). Focusing on the plasma density, velocity, and magnetic field, we interpolate the adaptively gridded simulation data onto a regular grid, and analyze the signatures that the jet produces as it propagates outward from the solar surface. The trans-Alfvénic nature of the jet front is confirmed by temporally differencing the plasma mass density and comparing the result with the local Alfvén speed. We perform a preliminary analysis of the magnetized plasma turbulence, and examine how the turbulence affects the overall structure of the jet. We also conduct simulated spacecraft fly-throughs of the jet, illustrating the signatures that spacecraft such as Solar Probe Plus may encounter in situ as the jet propagates into the heliosphere. These fly-throughs are performed in several different velocity regimes to better model the changing velocity of Solar Probe Plus relative to the Sun and its jets over the course of the mission.This research was supported by NASA grant NNG11PL10A 670.036 to CUA/IACS (M.A.R. and V.M.U.) and the Living With a Star Targeted Research and Technology (J.T.K. and C.R.D.) program.

  3. Cyanea capillata Bell Kinematics Analysis through Corrected In Situ Imaging and Modeling Using Strategic Discretization Techniques

    PubMed Central

    Villanueva, Alex A.; Priya, Shashank

    2014-01-01

    Obtaining accurate kinematic data of animals is essential for many biological studies and bio-inspired engineering. Many animals, however, are either too large or too delicate to transport to controlled environments where accurate kinematic data can be easily obtained. Often, in situ recordings are the only means available but are often subject to multi-axis motion and relative magnification changes with time leading to large discrepancies in the animal kinematics. Techniques to compensate for these artifacts were applied to a large jellyfish, Cyanea capillata, freely swimming in ocean waters. The bell kinematics were captured by digitizing exumbrella profiles for two full swimming cycles. Magnification was accounted for by tracking a reference point on the ocean floor and by observing the C. capillata exumbrella arclength in order to have a constant scale through the swimming cycles. A linear fit of the top bell section was used to find the body angle with respect to the camera coordinate system. Bell margin trajectories over two swimming cycles confirmed the accuracy of the correction techniques. The corrected profiles were filtered and interpolated to provide a set of time-dependent points along the bell. Discrete models of the exumbrella were used to analyze the bell kinematics. Exumbrella discretization was conducted using three different methods. Fourier series were fitted to the discretized models and subsequently used to analyze the bell kinematics of the C. capillata. The analysis showed that the bell did not deform uniformly over time with different segments lagging behind each other. Looping of the bell trajectory between contraction and relaxation was also present through most of the exumbrella. The bell margin had the largest looping with an outer path during contraction and inner path during relaxation. The subumbrella volume was approximated based on the exumbrella kinematics and was found to increase during contraction. PMID:25541980

  4. Quantification of the resist dissolution process: an in situ analysis using high speed atomic force microscopy

    NASA Astrophysics Data System (ADS)

    Santillan, Julius Joseph; Shichiri, Motoharu; Itani, Toshiro

    2016-03-01

    This work focuses on the application of a high speed atomic force microscope (HS-AFM) for the in situ visualization / quantification of the resist dissolution process. This technique, as reported in the past, has provided useful pointers on the formation of resist patterns during dissolution. This paper discusses about an investigation made on the quantification of what we refer to as "dissolution unit size" or the basic units of patterning material dissolution. This was done through the establishment of an originally developed analysis method which extracts the difference between two succeeding temporal states of the material film surface (images) to indicate the amount of change occurring in the material film at a specific span of time. Preliminary experiments with actual patterning materials were done using a positive-tone EUV model resist composed only of polyhydroxystyrene (PHS)-based polymer with a molecular weight of 2,500 and a polydispersity index of 1.2. In the absence of a protecting group, the material was utilized at a 50nm film thickness with post application bake of 90°C/60s. The resulting film is soluble in the alkali-based developer even without exposure. Results have shown that the dissolution components (dissolution unit size) of the PHS-based material are not of fixed size. Instead, it was found that aside from one constantly dissolving unit size, another, much larger dissolution unit size trend also occurs during material dissolution. The presence of this larger dissolution unit size suggests an occurrence of "polymer clustering". Such polymer clustering was not significantly present during the initial stages of dissolution (near the original film surface) but becomes more persistently obvious after the dissolution process reaches a certain film thickness below the initial surface.

  5. In-Situ Statistical Analysis of Autotune Simulation Data using Graphical Processing Units

    SciTech Connect

    Ranjan, Niloo; Sanyal, Jibonananda; New, Joshua Ryan

    2013-08-01

    Developing accurate building energy simulation models to assist energy efficiency at speed and scale is one of the research goals of the Whole-Building and Community Integration group, which is a part of Building Technologies Research and Integration Center (BTRIC) at Oak Ridge National Laboratory (ORNL). The aim of the Autotune project is to speed up the automated calibration of building energy models to match measured utility or sensor data. The workflow of this project takes input parameters and runs EnergyPlus simulations on Oak Ridge Leadership Computing Facility s (OLCF) computing resources such as Titan, the world s second fastest supercomputer. Multiple simulations run in parallel on nodes having 16 processors each and a Graphics Processing Unit (GPU). Each node produces a 5.7 GB output file comprising 256 files from 64 simulations. Four types of output data covering monthly, daily, hourly, and 15-minute time steps for each annual simulation is produced. A total of 270TB+ of data has been produced. In this project, the simulation data is statistically analyzed in-situ using GPUs while annual simulations are being computed on the traditional processors. Titan, with its recent addition of 18,688 Compute Unified Device Architecture (CUDA) capable NVIDIA GPUs, has greatly extended its capability for massively parallel data processing. CUDA is used along with C/MPI to calculate statistical metrics such as sum, mean, variance, and standard deviation leveraging GPU acceleration. The workflow developed in this project produces statistical summaries of the data which reduces by multiple orders of magnitude the time and amount of data that needs to be stored. These statistical capabilities are anticipated to be useful for sensitivity analysis of EnergyPlus simulations.

  6. Phobos Grooves Analysis: do They Favor the In Situ or the Asteroidal Capture Origin?

    NASA Astrophysics Data System (ADS)

    Pajola, M.; Simioni, E.; Cremonese, G.; Massironi, M.; Giacomini, L.

    2014-12-01

    Despite 43 years of spacecraft observations (Duxbury et al., 2014), Phobos origin is still a matter of great debate within the scientific community. Two main scenarios have been presented in the last decades: the in situ formation and the asteroidal capture origin. Both approaches present pros and cons that do not uniquely demonstrate the debated moon's origin; above that, Schmedemann et al. (2014) suggest that Phobos has an ancient cratering surface age of about 4.3-3.7 Ga, dating back to a period where the two proposed origins can be supported. Within such context frame, the work we present suggests a new interpretation of Phobos multiple grooves, which may point at one of the two scenarios. Phobos parallel grooves have been debated since their first observation on Viking images in 1976 (Veverka and Duxbury, 1977). Multiple origins have been proposed for their formation i) as the result of Mars tidal stress (Dobrovolskis, 1982); ii) as fractures directly related to the formation of the 9 km Stickney crater (Fujiwara and Asada, 1983) or iii) a formation caused by rolling boulders coming from the Stickney impact crater (Wilson and Head, 1989). Another formation scenario is that the grooves are chains of secondary impacts resulting from primary impact events on Mars (Murray and Iliffe, 2011), but recently Ramsley and Head (2014) indicated that the volume of ejecta coming from Mars to Phobos is insufficient to produce the grooves as secondary craters. Grooves are common on asteroids, as presented in 951 Gaspra (Veverka et al., 1994), 243 Ida (Belton et al., 1994), 433 Eros (Thomas et al., (2002), Buczkowski et al., 2008), 21 Lutetia (Massironi et al., 2011), 4 Vesta (Buczkowski et al., 2012). In this work we will show the preliminary results of a novel approach on the analysis of the grooves distribution, suggesting they are the remnants of an ancient parent body from which the moon could have been originated providing important implications on the origin of Phobos.

  7. Measurement and analysis of sarcomere length in rat cardiomyocytes in situ and in vitro

    PubMed Central

    Camelliti, P.; Bollensdorff, C.; Stuckey, D. J.; Picton, G.; Burton, R. A. B.; Clarke, K.; Kohl, P.

    2010-01-01

    Sarcomere length (SL) is an important determinant and indicator of cardiac mechanical function; however, techniques for measuring SL in living, intact tissue are limited. Here, we present a technique that uses two-photon microscopy to directly image striations of living cells in cardioplegic conditions, both in situ (Langendorff-perfused rat hearts and ventricular tissue slices, stained with the fluorescent marker di-4-ANEPPS) and in vitro (acutely isolated rat ventricular myocytes). Software was developed to extract SL from two-photon fluorescence image sets while accounting for measurement errors associated with motion artifact in raster-scanned images and uncertainty of the cell angle relative to the imaging plane. Monte-Carlo simulations were used to guide analysis of SL measurements by determining error bounds as a function of measurement path length. The mode of the distribution of SL measurements in resting Langendorff-perfused heart is 1.95 μm (n = 167 measurements from N = 11 hearts) after correction for tissue orientation, which was significantly greater than that in isolated cells (1.71 μm, n = 346, N = 9 isolations) or ventricular slice preparations (1.79 μm, n = 79, N = 3 hearts) under our experimental conditions. Furthermore, we find that edema in arrested Langendorff-perfused heart is associated with a mean SL increase; this occurs as a function of time ex vivo and correlates with tissue volume changes determined by magnetic resonance imaging. Our results highlight that the proposed method can be used to monitor SL in living cells and that different experimental models from the same species may display significantly different SL values under otherwise comparable conditions, which has implications for experiment design, as well as comparison and interpretation of data. PMID:20228259

  8. Fluorescence In Situ Hybridization Analysis of Atypical Melanocytic Proliferations and Melanoma in Young Patients

    PubMed Central

    DeMarchis, Emilia H; Swetter, Susan M; Jennings, Charay D; Kim, Jinah

    2014-01-01

    Morphologic heterogeneity among melanocytic proliferations is a common challenge in the diagnosis of melanoma. In particular, atypical melanocytic lesions in children, adolescents, and young adults may be difficult to classify because of significant morphologic overlap with melanoma. Recently a four-probe fluorescence in situ hybridization (FISH) protocol to detect chromosomal abnormalities in chromosomes 6 and 11 has shown promise for improving the classification of melanocytic lesions. We sought to determine the correlation between FISH results, morphology, and clinical outcomes in a series of challenging melanocytic proliferations in young patients. We retrospectively performed the standard four-probe FISH analysis on 21 melanocytic neoplasms from 21 patients younger than 25 years of age (range 5–25 years, mean 14.6 years) from Stanford University Medical Center who were prospectively followed for a median of 51 months (range 1–136 months). The study cohort included patients with 5 confirmed melanomas, 2 melanocytic tumors of uncertain malignant potential (MelTUMPs), 10 morphologically challenging atypical Spitz tumors (ASTs), and 4 typical Spitz nevi. FISH detected chromosomal aberrations in all five melanomas and in one MelTUMP, in which the patient developed subsequent lymph node and distant metastasis. All 10 ASTs, 4 Spitz nevi, and 1 of 2 MelTUMPs were negative for significant gains or losses in chromosomes 6 and 11q. Our findings demonstrated a strong correlation between positive FISH results and the histomorphologic impression of melanoma. This finding was also true for the MelTUMP with poor clinical outcome. Therefore FISH may serve as a helpful adjunct in the classification of controversial melanocytic tumors in young patients. PMID:24924836

  9. Chromosome analysis of nuclear power plant workers using fluorescence in situ hybridization and Giemsa assay.

    PubMed

    Hristova, Rositsa; Hadjidekova, Valeria; Grigorova, Mira; Nikolova, Teodora; Bulanova, Minka; Popova, Ljubomira; Staynova, Albena; Benova, Donka

    2013-09-01

    The aim of this study was to evaluate the genotoxic effects of ionizing radiation in vivo in exposed Bulgarian nuclear power plant workers by using classical cytogenetic and molecular cytogenetic analyses of peripheral lymphocytes. Chromosome analysis using fluorescence in situ hybrydization (FISH) and Giemsa techniques was undertaken on 63 workers and 45 administrative staff controls from the Bulgarian Nuclear Power Plant. Using the Giemsa method, the frequencies of cells studied with chromosome aberrations, dicentrics plus rings and chromosome fragments in the radiation workers were significantly higher compared with the control group (P = 0.044, P = 0.014, and P = 0.033, respectively). A significant association between frequencies of dicentrics plus rings and accumulated doses was registered (P < 0.01). In the present study, a FISH cocktail of whole chromosome paints for chromosomes 1, 4 and 11 was used. A significant association between frequency of translocations and accumulated doses was also observed (P < 0.001). Within the control group, a correlation was found between age and the spontaneous frequency of translocations. No correlation was found between smoking status and frequency of translocations. When compared with the control group, workers with accumulated doses up to 100 mSv showed no increase in genome translocation frequency, whereas workers with accumulated doses from 101 to 200 mSv showed a statistically significant doubling of genome translocation frequency (P = 0.009). Thus, in cases of chronic exposure and for purposes of retrospective dosimetry, the genome frequency of translocations is a more useful marker for evaluation of genotoxic effects than dicentric frequency.

  10. In situ structural analysis of microsomal UDP-glucuronyltransferases by radiation inactivation

    SciTech Connect

    Vessey, D.A.; Kempner, E.S.

    1989-04-15

    The structure of the UDP-glucuronyltransferases in microsomes from guinea pig and rat liver was examined in situ by radiation inactivation analysis. The p-nitrophenol conjugating activity of guinea pig microsomes increased at lower doses of radiation; at higher doses (greater than or equal to 36 megarads), activity showed a first order decline yielding a target size of 71 +/- 9 kDa. Treating microsomes with Triton X-100 eliminated the activation seen at lower doses of radiation and yielded a simple exponential decrease in activity which gave a larger target size (95 +/- 18 kDa). A monoexponential decrease in activity was seen in sonicated microsomes, at greater than or equal to 36 megarads. The same response was obtained when the reaction was assayed in the reverse direction. The estrone conjugating activity of guinea pig microsomes was similarly activated at lower doses of radiation and declined at higher doses (greater than or equal to 36 megarads), with a target size of 57 +/- 11 kDa. Allosteric activation of the enzyme by UDP-N-acetylglucosamine was eliminated by lower doses of radiation. Thus, activation of the enzyme by radiation, detergent, sonication, and UDP-N-acetylglucosamine appear to be interdependent. These activations are postulated to be due to the existence of the enzyme in an oligomeric form which can be dissociated into monomers with higher activity. The same biphasic activation-inactivation curves were obtained for p-nitrophenol conjugation in rat liver microsomes. The target sizes were 54 +/- 8 kDa (p-nitrophenol in the forward direction) and 66 +/- 10 kDa (p-nitrophenol in the reverse direction). Thus, the enzyme appears to be smaller in rat liver as compared with guinea pig liver. Lithocholate glucuronidating activity in rat liver microsomes (at greater than 36 megarads) gave a target size of 74 +/- 1 kDa.

  11. In situ SIMS oxygen isotope analysis of olivine in the Tibetan mantle xenoliths

    NASA Astrophysics Data System (ADS)

    Zhao, Zhidan; Zhu, Di-Cheng; Liu, Dong; Mo, Xuanxue

    2016-04-01

    Although the mantle-derived xenoliths from Lhasa terrane provide a means of directly investigating the mantle underlying the southern part of the plateau, they were rarely found in the region. The only case of mantle xenoliths came from the Sailipu ultrapotassic volcanic rocks, erupted at ˜17 Ma, which have indicated that the subcontinental mantle of southern Tibetan Plateau is hot and strongly influenced by metasomatism (Zhao et al., 2008a, b; Liu et al., 2011). A further study by Liu et al.(2014) of in-situ oxygen isotope of olivine crystals in Sailipu mantle xenoliths identify a metasomatized mantle reservoir that interpreted as the sub-arc lithospheric mantle, with anomalously enriched oxygen isotopes (δ18O=8.03). Here we present oxygen isotopes data on the Sailipu mantle xenolith olivines, using different method of sample preparation. Mantle xenoliths (less than 1 cm in diameter) together originally with their host volcanic rocks were prepared in epoxy adjacent to grains of a San Carlos olivine intralaboratory standard and then polished to a flat and smooth surface. Oxygen isotope compositions of olivines occurs both in mantle xenolith and as phenocryst in the host rock, were analyzed in situ using CAMECA SIMS-1280 ion microprobe at the Institute of Geology and Geophysics, Chinese Academy of Sciences. We also performed traditional oxygen isotope analysis on three olivine phenocrysts separates from the host lava. Our new data show: (1) The mantle xenolith olivines have typical mantle oxygen isotopic composition (δ18O=4.8-8.0‰ with average of 5.5±0.2‰ n=105) with variety Fo#(78-90), (2) Oxygen isotopes of situ olivine phenocrysts in the Sailipu lavas (δ18O=7.1-9.2‰ Fo#=70-84, n=66), are similar to that of the whole rock (δ18O=7.0-9.4‰ Fo#=64-74, n=8, Zhao et al., 2009), and three olivine phenocryst grains (δ18O=7.2-7.8); (3) The intralaboratory standard of San Carlos olivine can be a suitable standard using for analyzing olivines with Fo not only

  12. Demonstration of Longevity of Microdevices for in situ Analysis of Organic Molecules on Outer Planet Icy Moons

    NASA Astrophysics Data System (ADS)

    Duca, Z. A.; Tan, G. K.; Cantrell, T. P.; Van Enige, M. A.; Mathies, R. A.; Stockton, A. M.

    2015-10-01

    Quantitative compositional in situ analysis of small organic molecules in extraterrestrial environments provides essential information on planetary formation and evolution, as well as the capability to find potential signatures of past or present life. Microchip capillary electrophoresis (μCE) with laser-induced fluorescence (LIF) detection has proven to be capable of highly sensitive (sub parts-per-trillion, or pptr) automated quantitative compositional analysis of multiple organic compound classes. Here, we demonstrate the retained functionality of automated μCE-LIF microdevices fabricated in 2005. After 5 hours of vacuum cycling, a pneumatically-controlled valve re-opened and regained normal use. The ability of these microdevices to retain functionality after over 10 years of storage combined with system sensitivity, reliable autonomous control, and chiral resolution further supports the value of μCE-LIF as an in situ technique for outer planetary missions.

  13. APPLICATIONS ANALYSIS REPORT: TOXIC TREATMENTS, IN-SITU STEAM/HOT-AIR STRIPPING TECHNOLOGY

    EPA Science Inventory

    This document is an evaluation of the performance of the Toxic Treatments (USA), Inc., (TTUSA) in situ steam/hot-air stripping technology and its applicability as an on-site treatment technique for hazardous waste site soil cleanup of volatile and semivolatile contaminants. Both ...

  14. Instrumentation for in situ sampling and analysis of compounds of interest to Astrobiology in the lower atmosphere and surface of Titan

    NASA Technical Reports Server (NTRS)

    Holland, Paul M.; Kojiro, Daniel R.; Stimac, Robert; Kaye, William; Takeuchi, Nori

    2006-01-01

    Instrumentation for exploration of the solar system will require new enabling technology for in situ sample acquisition and analysis of pre-biotic chemistry in extreme planetary environments, such as that encountered at the surface of Titan. The potential use of balloon aero-rovers for Titan places special emphasis on the importance of miniaturization, low power and low usage of consumables. To help meet this need, we are developing a miniature gas chromatograph coupled with a new Mini-Cell ion mobility spectrometer (GC-IMS), and one of us (PMH) has begun development work on a miniaturized cryogenic inlet system with sampling probes for Titan. This instrumentation, and its approach for meeting measurement needs for the analysis of prebiotic chemistry on Titan, will be discussed.

  15. In-situ chemical and isotopic analysis of a comet by Ptolemy

    NASA Astrophysics Data System (ADS)

    Morse, A. D.; Barber, S. J.; Leese, M. R.; Morgan, G. H.; Sheridan, S.; Wright, I. P.; Zarnecki, J. C.; Pillinger, C. T.

    2003-04-01

    Ptolemy is a Gas Chromatograph - Mass Spectrometer, one of the instruments on board the Rosetta Lander, intended to land on comet Wirtanen. Ptolemy is designed to measure the composition and isotope ratios of gases released from comet samples during pyrolysis or combustion. The total mass of the instrument is 4.6 kg and it fits into a space of 33 x 25 x 11 cm. Following touchdown on the comet nucleus, comet samples are obtained by the SD2 instrument, which drills a core sample and loads it into one of 26 ovens on a carousel. One of the ovens already contains a molecular sieve absorbent so that the comet "atmosphere" can also be sampled. The sample is then heated by the oven and the gases released are transferred to the Ptolemy instrument. Within Ptolemy, the raw sample gases can be chemically processed to convert them into molecules suitable for isotopic analysis. The processed sample mixture gas is injected into one of three GC columns to separate it into its constituent components before analysis by the mass spectrometer. An ion trap mass spectrometer has been used as this gives considerable reduction of mass, power and volume, compared to standard magnetic sector mass spectrometers normally used for isotopic analysis. Laboratory experiments have shown that an ion trap is capable of measuring carbon and nitrogen isotope ratios to a precision of +/- 20 per mil or better. We will present data from the Flight instrument plus results of ongoing characterisation studies using the identical Qualification Model.

  16. Development of a Low Power Gas Chromatograph-Mass Spectrometer for In-Situ Detection of Organics in Martian Soil

    NASA Technical Reports Server (NTRS)

    Pinnick, Veronica; Buch, Arnaud; VanAmerom, Friso H. W.; Danell, Ryan M.; Brinckerhoff, William; Mahaffy, Paul; Cotter, Robert J.

    2011-01-01

    The Mars Organic Molecule Analyzer (MOMA) is a joint venture by NASA and the European Space Agency (ESA) to develop a sensitive, light-weight, low-power mass spectrometer for chemical analysis on Mars. MOMA is a key analytical instrument aboard the 2018 ExoMars rover mission seeking signs of past or present life. The current prototype was built to demonstrate operation of gas chromatography (OC) and laser desorption (LD) mass spectrometry under martian ambient conditions (5-7 Torr of CO2-rich atmosphere). Recent reports have discussed the MO MA concept, design and performance. Here, we update the current prototype performance, focusing specifically on the GCMS mode.

  17. Miniature robotic sample analysis lab for planetary in situ mineralogy and microbiology

    NASA Astrophysics Data System (ADS)

    Kruzelecky, Roman; Wong, Brian; Haddad, Emile; Jamroz, Wes; Cloutis, Edward; Strong, Kimberly; Ghafoor, Nadeem; Jessen, Sean

    The current Martian surface conditions are relatively inhospitable, with average diurnal temperature ranges from 170 K to 268 K, a low air pressure of about 7 to 10 mbar consisting mainly of CO2 and negligible ozone to moderate the UV portion of the incident solar radiation. The intense UV effectively sterilizes the surface, and in combination with the low air pressure, makes any unbound surface liquid water unstable. However, there is mounting evidence to support the notion that the near subsurface of Mars may differ dramatically from the uppermost surface. The Inukshuk landed Mars mission, as initially developed under a pre-Phase A study for the Canadian Space Agency, focuses on the search for hydrated mineralogy and subsurface water sites that can provide evidence of past or present life. The mission will be achieved using a miniature suite of complementary spectral instruments operating in collaboration with a robotic tethered mole drill system for the systematic in situ subsurface exploration of the planetary mineralogy, water content and microbiology. The Inukshuk mission will, for the first time, study variations in the Mars subsurface characteristics and composition in detail at different locations. These will be correlated with the current planetary boundary layer conditions using an elevating Skycam platform and surface stand-off measurement capabilities. The subsurface analysis will be provided using a miniature bore-hole probe integrated within the mole driller and interfaced to the rover-based instrument suite using an IR fiber-optic link. This will allow subsurface mapping of the stratigraphy and composition in steps of a few mm to depths beyond 1 m. During the drilling, the bore-hole probe will be shielded using a wiper/shutter system. The in situ bore-hole analysis has an advantage for detecting biomarkers for astrobiology on Mars in that the alteration of the sample by surface radiation can be minimized. The bore-hole sample analysis will employ

  18. Borehole Stability Analysis of Horizontal Drilling in Shale Gas Reservoirs

    NASA Astrophysics Data System (ADS)

    Yuan, Jun-Liang; Deng, Jin-Gen; Tan, Qiang; Yu, Bao-Hua; Jin, Xiao-Chun

    2013-09-01

    Serious wellbore instability occurs frequently during horizontal drilling in shale gas reservoirs. The conventional forecast model of in situ stresses is not suitable for wellbore stability analysis in laminated shale gas formations because of the inhomogeneous mechanical properties of shale. In this study, a new prediction method is developed to calculate the in situ stresses in shale formations. The pore pressure near the borehole is heterogeneous along both the radial and tangential directions due to the inhomogeneity in the mechanical properties and permeability. Therefore, the stress state around the wellbore will vary with time after the formation is drained. Besides, based on the experimental results, a failure criterion is verified and applied to determine the strength of Silurian shale in the Sichuan Basin, including the long-term strength of gas shale. Based on this work, horizontal well borehole stability is analyzed by the new in situ stress prediction model. Finally, the results show that the collapse pressure will be underestimated if the conventional model is used in shale gas reservoirs improperly. The collapse pressure of a horizontal well is maximum at dip angle of 45°. The critical mud weight should be increased constantly to prevent borehole collapse if the borehole is exposed for some time.

  19. In situ flash x-ray high-speed computed tomography for the quantitative analysis of highly dynamic processes

    NASA Astrophysics Data System (ADS)

    Moser, Stefan; Nau, Siegfried; Salk, Manfred; Thoma, Klaus

    2014-02-01

    The in situ investigation of dynamic events, ranging from car crash to ballistics, often is key to the understanding of dynamic material behavior. In many cases the important processes and interactions happen on the scale of milli- to microseconds at speeds of 1000 m s-1 or more. Often, 3D information is necessary to fully capture and analyze all relevant effects. High-speed 3D-visualization techniques are thus required for the in situ analysis. 3D-capable optical high-speed methods often are impaired by luminous effects and dust, while flash x-ray based methods usually deliver only 2D data. In this paper, a novel 3D-capable flash x-ray based method, in situ flash x-ray high-speed computed tomography is presented. The method is capable of producing 3D reconstructions of high-speed processes based on an undersampled dataset consisting of only a few (typically 3 to 6) x-ray projections. The major challenges are identified, discussed and the chosen solution outlined. The application is illustrated with an exemplary application of a 1000 m s-1 high-speed impact event on the scale of microseconds. A quantitative analysis of the in situ measurement of the material fragments with a 3D reconstruction with 1 mm voxel size is presented and the results are discussed. The results show that the HSCT method allows gaining valuable visual and quantitative mechanical information for the understanding and interpretation of high-speed events.

  20. Touch Spray Mass Spectrometry for In Situ Analysis of Complex Samples

    PubMed Central

    Kerian, Kevin S.; Jarmusch, Alan K.; Cooks, R. Graham

    2014-01-01

    Touch spray, a spray-based ambient in-situ ionization method, uses a small probe, e.g. a teasing needle to pick up sample and the application of voltage and solvent to cause field-induced droplet emission. Compounds extracted from the microsample are incorporated into the sprayed micro droplets. Performance tests include disease state of tissue, microorganism identification, and therapeutic drug quantitation. Chemical derivatization is performed simultaneously with ionization. PMID:24756256

  1. Mechanistic analysis of Zein nanoparticles/PLGA triblock in situ forming implants for glimepiride

    PubMed Central

    Ahmed, Osama Abdelhakim Aly; Zidan, Ahmed Samir; Khayat, Maan

    2016-01-01

    Objectives The study aims at applying pharmaceutical nanotechnology and D-optimal fractional factorial design to screen and optimize the high-risk variables affecting the performance of a complex drug delivery system consisting of glimepiride–Zein nanoparticles and inclusion of the optimized formula with thermoresponsive triblock copolymers in in situ gel. Methods Sixteen nanoparticle formulations were prepared by liquid–liquid phase separation method according to the D-optimal fractional factorial design encompassing five variables at two levels. The responses investigated were glimepiride entrapment capacity (EC), particle size and size distribution, zeta potential, and in vitro drug release from the prepared nanoparticles. Furthermore, the feasibility of embedding the optimized Zein-based glimepiride nanoparticles within thermoresponsive triblock copolymers poly(lactide-co-glycolide)-block-poly(ethylene glycol)-block-poly(lactide-co-glycolide) in in situ gel was evaluated for controlling glimepiride release rate. Results Through the systematic optimization phase, improvement of glimepiride EC of 33.6%, nanoparticle size of 120.9 nm with a skewness value of 0.2, zeta potential of 11.1 mV, and sustained release features of 3.3% and 17.3% drug released after 2 and 24 hours, respectively, were obtained. These desirability functions were obtained at Zein and glimepiride loadings of 50 and 75 mg, respectively, utilizing didodecyldimethylammonium bromide as a stabilizer at 0.1% and 90% ethanol as a common solvent. Moreover, incorporating this optimized formulation in triblock copolymers-based in situ gel demonstrated pseudoplastic behavior with reduction of drug release rate as the concentration of polymer increased. Conclusion This approach to control the release of glimepiride using Zein nanoparticles/triblock copolymers-based in situ gel forming intramuscular implants could be useful for improving diabetes treatment effectiveness. PMID:26893561

  2. Formation of carbon nanotubes: In situ optical analysis using laser-induced incandescence and laser-induced fluorescence

    NASA Astrophysics Data System (ADS)

    Cau, M.; Dorval, N.; Attal-Trétout, B.; Cochon, J.-L.; Foutel-Richard, A.; Loiseau, A.; Krüger, V.; Tsurikov, M.; Scott, C. D.

    2010-04-01

    Gas-phase production of carbon nanotubes in presence of a metal catalyst with a continuous wave CO2 laser is investigated by combining coherent anti-Stokes Raman scattering (CARS), laser-induced fluorescence (LIF), and laser-induced incandescence (LII). These in situ techniques provide a unique investigation of the different transformation processes of the primarily carbon and metal vapors issued from the vaporization of the target by the laser and the temperature at which these processes occur. Continuous-wave laser provides with stable continuous vaporization conditions very well suited for such in situ investigations. Temperature profiles inside the reactor are known from CARS measurements and flow calculations. Carbon soot, density, and size of carbon aggregates are determined by LII measurements. LIF measurements are used to study the gas phases, namely, C2 and C3 radicals which are the very first steps of carbon recombination, and metal catalysts gas phase. Spectral investigations allow us to discriminate the signal from each species by selecting the correct pair of excitation/detection wavelengths. Spatial distributions of the different species are measured as a function of target composition and temperature. The comparison of LIF and LII signals allow us to correlate the spatial evolution of gas and soot in the scope of the different steps of the nanotube growth already proposed in the literature and to identify the impact of the chemical nature of the catalyst on carbon condensation and nanotube nucleation. Our study presents the first direct evidence of the nanotube onset and that the nucleation proceeds from a dissolution-segregation process from metal particles as assumed in the well-known vapor-liquid-solid model. Comparison of different catalysts reveals that this process is strongly favored when Ni is present.

  3. Vapor and gas sampling of single-shell tank 241-BX-102 using the in situ vapor sampling system

    SciTech Connect

    Lockrem, L.L.

    1997-08-05

    The Vapor Issue Resolution Program tasked the Vapor Team (VT) to collect representative headspace samples from Hanford Site single-shell tank (SST) 241-BX-102. This document presents In Situ vapor Sampling System (ISVS) data resulting from the July 31, 1996 sampling of SST 241-BX-102. Analytical results will be presented in separate reports issued by the Pacific Northwest National Laboratory (PNNL) which supplied and analyzed the sample media.

  4. Analysis of microRNA expression by in situ hybridization with RNA oligonucleotide probes

    PubMed Central

    Thompson, Robert C.; Deo, Monika; Turner, David L.

    2007-01-01

    In situ hybridization is an important tool for analyzing gene expression and developing hypotheses about gene functions. The discovery of hundreds of microRNA (miRNA) genes in animals has provided new challenges for analyzing gene expression and functions. The small size of the mature miRNAs (∼20-24 nucleotides in length) presents difficulties for conventional in situ hybridization methods. However, we have developed a modified in situ hybridization method for detection of mammalian miRNAs in tissue sections, based upon the use of RNA oligonucleotide probes in combination with highly specific wash conditions. Here we present detailed procedures for detection of miRNAs in tissue sections or cultured cells. The methods described can utilize either nonradioactive hapten-conjugated probes that are detected by enzyme-coupled antibodies, or radioactively labeled probes that are detected by autoradiography. The ability to visualize miRNA expression patterns in tissue sections provides an additional tool for the analyses of miRNA expression and function. In addition, the use of radioactively labeled probes should facilitate quantitative analyses of changes in miRNA gene expression. PMID:17889803

  5. Microchip capillary electrophoresis instrumentation for in situ analysis in the search for extraterrestrial life.

    PubMed

    Mora, Maria F; Stockton, Amanda M; Willis, Peter A

    2012-09-01

    The search for signs of life on extraterrestrial planetary bodies is among NASA's top priorities in Solar System exploration. The associated pursuit of organics and biomolecules as evidence of past or present life demands in situ investigations of planetary bodies for which sample return missions are neither practical nor affordable. These in situ studies require instrumentation capable of sensitive chemical analyses of complex mixtures including a broad range of organic molecules. Instrumentation must also be capable of autonomous operation aboard a robotically controlled vehicle that collects data and transmits it back to Earth. Microchip capillary electrophoresis (μCE) coupled to laser-induced fluorescence (LIF) detection provides this required sensitivity and targets a wide range of relevant organics while offering low mass, volume, and power requirements. Thus, this technology would be ideally suited for in situ studies of astrobiology targets, such as Mars, Europa, Enceladus, and Titan. In this review, we introduce the characteristics of these planetary bodies that make them compelling destinations for extraterrestrial astrobiological studies, and the principal groups of organics of interest associated with each. And although the technology we describe here was first developed specifically for proposed studies of Mars, by summarizing its evolution over the past decade, we demonstrate how μCE-LIF instrumentation has become an ideal candidate for missions of exploration to all of these nearby worlds in our Solar System.

  6. In situ dissolution analysis using coherent anti-Stokes Raman scattering (CARS) and hyperspectral CARS microscopy.

    PubMed

    Fussell, Andrew; Garbacik, Erik; Offerhaus, Herman; Kleinebudde, Peter; Strachan, Clare

    2013-11-01

    The solid-state form of an active pharmaceutical ingredient (API) in an oral dosage form plays an important role in determining the dissolution rate of the API. As the solid-state form can change during dissolution, there is a need to monitor the oral dosage form during dissolution testing. Coherent anti-Stokes Raman scattering (CARS) microscopy provides rapid, spectrally selective imaging to monitor the oral dosage form during dissolution. In this study, in situ CARS microscopy was combined with inline UV absorption spectroscopy to monitor the solid-state change in oral dosage forms containing theophylline anhydrate undergoing dissolution and to correlate the solid-state change with a change in dissolution rate. The results from in situ CARS microscopy showed that theophylline anhydrate converted to theophylline monohydrate during dissolution resulting in a reduction in the dissolution rate. The addition of methyl cellulose to the dissolution medium was found to delay the theophylline monohydrate growth and changed the morphology of the monohydrate. The net effect was an increased dissolution rate for theophylline anhydrate. Our results show that in situ CARS microscopy combined with inline UV absorption spectroscopy is capable of monitoring oral dosage forms undergoing dissolution and correlating changes in solid-state form with changes in dissolution rate. PMID:23994672

  7. An in situ heating TEM analysis method for an interface reaction.

    PubMed

    Tanigaki, Toshiaki; Ito, Katsuji; Nagakubo, Yasuhira; Asakawa, Takayuki; Kanemura, Takashi

    2009-10-01

    In order to analyze the thermal property of nano-sized materials, an in situ observation technique that allows highly sensitive energy dispersive x-ray spectroscopic (EDX) analyses and high-resolution in situ heating observation of precision specimens is required. A method for the in situ observation of the interface reaction using an analytical transmission electron microscopy (TEM) and a specimen-heating holder was developed. The specimen holder used in this study was a direct-heating type having a fine tungsten wire heater. For sensitive analyses including an EDX map of composition changes during the interface reaction, a space toward the EDX detector with a take-off angle of 20 degrees was made in the specimen holder. Samples were prepared by attaching a micro-sample directly to the heater using the focused ion beam (FIB) micro-sampling technique. It was confirmed that the sensitive EDX map and electron diffraction analyses were possible during the reaction, and that the resolution of this technique was of the order of 0.223 nm at 550 degrees C. PMID:19376815

  8. Microchip capillary electrophoresis instrumentation for in situ analysis in the search for extraterrestrial life.

    PubMed

    Mora, Maria F; Stockton, Amanda M; Willis, Peter A

    2012-09-01

    The search for signs of life on extraterrestrial planetary bodies is among NASA's top priorities in Solar System exploration. The associated pursuit of organics and biomolecules as evidence of past or present life demands in situ investigations of planetary bodies for which sample return missions are neither practical nor affordable. These in situ studies require instrumentation capable of sensitive chemical analyses of complex mixtures including a broad range of organic molecules. Instrumentation must also be capable of autonomous operation aboard a robotically controlled vehicle that collects data and transmits it back to Earth. Microchip capillary electrophoresis (μCE) coupled to laser-induced fluorescence (LIF) detection provides this required sensitivity and targets a wide range of relevant organics while offering low mass, volume, and power requirements. Thus, this technology would be ideally suited for in situ studies of astrobiology targets, such as Mars, Europa, Enceladus, and Titan. In this review, we introduce the characteristics of these planetary bodies that make them compelling destinations for extraterrestrial astrobiological studies, and the principal groups of organics of interest associated with each. And although the technology we describe here was first developed specifically for proposed studies of Mars, by summarizing its evolution over the past decade, we demonstrate how μCE-LIF instrumentation has become an ideal candidate for missions of exploration to all of these nearby worlds in our Solar System. PMID:22965706

  9. In situ microscopic analysis of asbestos and synthetic vitreous fibers retained in hamster lungs following inhalation.

    PubMed Central

    Rogers, R A; Antonini, J M; Brismar, H; Lai, J; Hesterberg, T W; Oldmixon, E H; Thevenaz, P; Brain, J D

    1999-01-01

    Hamsters breathed, nose-only, for 13 weeks, 5 days/week, 6 hr/day, either man-made vitreous fiber (MMVF)10a, MMVF33, or long amosite asbestos at approximately 300 World Health Organization (WHO) fibers/cc or long amosite at 25 WHO fibers/cc. [World Health Organization fibers are longer than 5 microm and thicker than 3 microm, with aspect ratio >3.] After sacrifice, fiber burden was estimated (left lungs) by ashing and scanning electron microscopy (ashing/SEM) or (right middle lobes) by confocal laser scanning microscopy (CLSM) in situ. In situ CLSM also provided three-dimensional views of fibers retained, undisturbed, in lung tissue. Fibers of each type were lodged in alveoli and small airways, especially at airway bifurcations, and were seen fully or partly engulfed by alveolar macrophages. Amosite fibers penetrated into and through alveolar septa. Length densities of fibers in parenchyma (total length of fiber per unit volume of lung) were estimated stereologically from fiber transsections counted on two-dimensional optical sections and were 30.5, 25.3, 20.0, and 81.6 mm/mm3 for MMVF10a, MMVF33, and low- and high-dose amosite, respectively. Lengths of individual fibers were measured in three dimensions by tracking individual fibers through series of optical sections. Length distributions of amosite fibers aerosolized, but before inhalation versus after retention in the lung were similar, whether determined by ashing/SEM or in situ CLSM. In contrast, the fraction of short MMVF10a and MMVF33 fibers increased and the geometric mean fiber lengths of both MMVFs decreased by approximately 60% during retention. Most likely due to fiber deposition pattern and differences in sampling, fiber burdens [MMVF10a, MMVF33, and amosite (high dose; 269 WHO fibers/cc)] determined by ashing/SEM were 1.4, 1. 5, and 3.5 times greater, respectively, than those calculated from in situ CLSM data. In situ CLSM is able to provide detailed information about the anatomic sites of fiber

  10. An in situ FTIR spectroscopic and thermogravimetric analysis study of the dehydration and dihydroxylation of SnO2: the contribution of the (100), (110) and (111) facets.

    PubMed

    Christensen, P A; Attidekou, P S; Egdell, R G; Maneelok, S; Manning, D A C

    2016-08-17

    Nanoparticulate SnO2 produced by a hydrothermal method was characterised by BET, XRD, TGA-MS and in situ variable temperature diffuse reflectance infra red spectroscopy (DRIFTS) to determine the surface behaviour of water. For the (100) facets, hydrogen bonding does not occur, and water adsorption is less strong than for the (111) and (110) facets where hydrogen bonding does occur. Reversible uptake of oxygen was observed. These findings have implications for other surface-gas reactions in which Ni and Sb co-doped SnO2 (NATO) anodes are used for ozone generation. BET showed the relatively high surface area and nanometer scale of the SnO2 particles, whilst XRD confirmed the nano dimension of the crystallites and showed only the cassiterite phase. TGA analysis indicated four temperature regions over which mass loss was observed. These and the in situ DRIFTS studies revealed the existence of various forms of water associated with specific crystal facets of the SnO2, as well as the existence of isolated O-H groups and adsorbed oxygen species. Electronic absorptions were also observed and the data rationalised in terms of the existence of both free electron absorptions, and absorptions from oxygen vacancy states. The role of adsorbed molecular oxygen in electrochemical ozone generation at Ni and Sb co-doped SnO2 (NATO) anodes was strongly suggested by this work. PMID:27488937

  11. Evaluating macroinvertebrate population and community level effects in outdoor microcosms: Use of in situ bioassays and multivariate analysis

    SciTech Connect

    Shaw, J.L.; Manning, J.P.

    1996-05-01

    Evaluating toxicant effects on aquatic communities is difficult due to the ecological complexity at higher levels of organization. Two methods were assessed to improve the understanding of effects on macroinvertebrate communities in aquatic model ecosystems. First, in situ bioassay population effects were used to interpret effects at a higher organization level. Second, canonical discriminant analysis was used to investigate effects on community structure. In situ bioassays were conducted on six occasions in 17-m{sup 3} microcosms treated with copper sulfate. Macroinvertebrates occurring naturally in the microcosms were monitored. Epibenthic in situ bioassays were conducted using Caenis sp. (Ephemeroptera) and Hyalella azteca (Amphipoda) and a water column bioassay was conducted using Notonectidae (Hemiptera). Survival and growth were assessed after 3 d. Effects of copper on both notonectidae and Caenis were observed following application. However, the final Caenis epibenthic bioassays indicated that potential for recovery and survival was {ge}95%. Potential for recovery was less distinct in the water column bioassays. Copper effects also occurred on epibenthic macroinvertebrate populations and communities. Only four taxa, including Caenis, distinguished community differences among copper treatments soon after application. Later, communities showed similarities to the pretreatment bioassay. However, actual recovery was less apparent than the potential for recovery indicated by the bioassays, and community differences due to Caenis persisted.

  12. Spreading and fluorescence in situ hybridization of male and female meiocyte chromosomes from Arabidopsis thaliana for cytogenetical analysis.

    PubMed

    Armstrong, Susan

    2013-01-01

    Advances in molecular biology and in the genetics of Arabidopsis thaliana have led to it becoming an important model for the analysis of meiosis in plants. Cytogenetic investigations are pivotal to meiotic studies and a number of technological improvements for Arabidopsis cytology have provided a range of tools to investigate chromosome behavior during meiosis. This chapter contains a detailed description of cytological techniques currently used in our laboratory for the basic preparation of meiotic chromosomes for investigation of the female and male meiotic pathway and fluorescence in situ hybridization (FISH) analysis for the frequency and distribution of crossovers (chiasmata) at metaphase I.

  13. Supercritical Carbon Dioxide Extraction of Coronene in the Presence of Perchlorate for In Situ Chemical Analysis of Martian Regolith

    NASA Astrophysics Data System (ADS)

    McCaig, Heather C.; Stockton, Amanda; Crilly, Candice; Chung, Shirley; Kanik, Isik; Lin, Ying; Zhong, Fang

    2016-09-01

    The analysis of the organic compounds present in the martian regolith is essential for understanding the history and habitability of Mars, as well as studying the signs of possible extant or extinct life. To date, pyrolysis, the only technique that has been used to extract organic compounds from the martian regolith, has not enabled the detection of unaltered native martian organics. The elevated temperatures required for pyrolysis extraction can cause native martian organics to react with perchlorate salts in the regolith and possibly result in the chlorohydrocarbons that have been detected by in situ instruments. Supercritical carbon dioxide (SCCO2) extraction is an alternative to pyrolysis that may be capable of delivering unaltered native organic species to an in situ detector. In this study, we report the SCCO2 extraction of unaltered coronene, a representative polycyclic aromatic hydrocarbon (PAH), from martian regolith simulants, in the presence of 3 parts per thousand (ppth) sodium perchlorate. PAHs are a class of nonpolar molecules of astrobiological interest and are delivered to the martian surface by meteoritic infall. We also determined that the extraction efficiency of coronene was unaffected by the presence of perchlorate on the regolith simulant, and that no sodium perchlorate was extracted by SCCO2. This indicates that SCCO2 extraction can provide de-salted samples that could be directly delivered to a variety of in situ detectors. SCCO2 was also used to extract trace native fluorescent organic compounds from the martian regolith simulant JSC Mars-1, providing further evidence that SCCO2 extraction may provide an alternative to pyrolysis to enable the delivery of unaltered native organic compounds to an in situ detector on a future Mars rover.

  14. Preliminary System Analysis of In Situ Resource Utilization for Mars Human Exploration

    NASA Technical Reports Server (NTRS)

    Rapp, Donald; Andringa, Jason; Easter, Robert; Smith, Jeffrey H .; Wilson, Thomas; Clark, D. Larry; Payne, Kevin

    2005-01-01

    We carried out a system analysis of processes for utilization of Mars resources to support human exploration of Mars by production of propellants from indigenous resources. Seven ISRU processes were analyzed to determine mass. power and propellant storage volume requirements. The major elements of each process include C02 acquisition, chemical conversion, and storage of propellants. Based on a figure of merit (the ratio of the mass of propellants that must be brought from Earth in a non-ISRU mission to the mass of the ISRU system. tanks and feedstocks that must be brought from Earth for a ISRU mission) the most attractive process (by far); is one where indigenous Mars water is accessible and this is processed via Sabatier/Electrolysis to methane and oxygen. These processes are technically relatively mature. Other processes with positive leverage involve reverse water gas shift and solid oxide electrolysis.

  15. Direct gas-solid carbonation kinetics of steel slag and the contribution to in situ sequestration of flue gas CO(2) in steel-making plants.

    PubMed

    Tian, Sicong; Jiang, Jianguo; Chen, Xuejing; Yan, Feng; Li, Kaimin

    2013-12-01

    Direct gas-solid carbonation of steel slag under various operational conditions was investigated to determine the sequestration of the flue gas CO2 . X-ray diffraction analysis of steel slag revealed the existence of portlandite, which provided a maximum theoretical CO2 sequestration potential of 159.4 kg CO 2 tslag (-1) as calculated by the reference intensity ratio method. The carbonation reaction occurred through a fast kinetically controlled stage with an activation energy of 21.29 kJ mol(-1) , followed by 10(3) orders of magnitude slower diffusion-controlled stage with an activation energy of 49.54 kJ mol(-1) , which could be represented by a first-order reaction kinetic equation and the Ginstling equation, respectively. Temperature, CO2 concentration, and the presence of SO2 impacted on the carbonation conversion of steel slag through their direct and definite influence on the rate constants. Temperature was the most important factor influencing the direct gas-solid carbonation of steel slag in terms of both the carbonation conversion and reaction rate. CO2 concentration had a definite influence on the carbonation rate during the kinetically controlled stage, and the presence of SO2 at typical flue gas concentrations enhanced the direct gas-solid carbonation of steel slag. Carbonation conversions between 49.5 % and 55.5 % were achieved in a typical flue gas at 600 °C, with the maximum CO2 sequestration amount generating 88.5 kg CO 2 tslag (-1) . Direct gas-solid carbonation of steel slag showed a rapid CO2 sequestration rate, high CO2 sequestration amounts, low raw-material costs, and a large potential for waste heat utilization, which is promising for in situ carbon capture and sequestration in the steel industry.

  16. Miniaturised 'lab-on-a-chip' nitrate analyser applied to high resolution in situ analysis of glacial meltwater

    NASA Astrophysics Data System (ADS)

    Beaton, A.; Mowlem, M.; Wadham, J. L.

    2013-12-01

    In situ chemical measurements of glacial meltwater can provide high temporal and spatial resolution data that allow us to infer biogeochemical processes and calculate export from glacial systems. Despite this, in situ measurements of single chemical parameters in glacial meltwater have so far largely been restricted to pH and dissolved oxygen. The lack of high performance ruggedized in situ sensors for other analytes means that the laboratory-based analysis of manually collected samples is still routine. Microfluidics (through lab-on-a-chip technology) permits the miniaturisation of established chemical analysis techniques so that they can be performed in situ. The advantages of decreased size and low power and reagent consumption make these systems suitable for deployment in extreme and inaccessible environments where regular manual sample collection is logistically difficult. We present data from a novel stand-alone microfluidic wet chemical nitrate analyser that has been deployed to monitor a proglacial meltwater river draining from the Greenland ice sheet. By performing a measurement every 20 minutes, the analyser was able to reveal diurnal fluctuations and short term trends in nitrate concentrations that would not discernible using standard daily sampling. High resolution in situ measurements such as these can allow a more accurate determination of nutrient export fluxes from glacial systems into the polar oceans, and allow enhanced interpretation of water quality datasets. Steps have been taken to ruggedize the system so that it can survive the freeze-thaw conditions, dilute concentrations and high sediment loads that can be associated with cryospheric environments. The system is small, has low power consumption and detects nitrate and nitrite with a limit of detection (LOD) of 0.025 μM, which is sufficient for low nutrient glacial environments. On-going work looks to deploy similar nutrient analysers more widely, not only in glacial systems, but also in

  17. A multi-scale analysis of in-situ precipitation data across the Sahelian Gourma

    NASA Astrophysics Data System (ADS)

    Guichard, Françoise; Frappart, Frédéric; Hiernaux, Pierre; Kergoat, Laurent; Mougin, Eric; Arjounin, Marc; Koité, Mohamed; Lebel, Thierry; Bock, Olivier; Meynadier, Rémi

    2010-05-01

    Droughts and floods are recurrent features of the Sahelian climate, which is also characterized by a very large variability of rainfall, in both space and time. The present study focuses on the Malian Gourma (2°W-1°E, 14.5°N-17.5°N), located in the Central Sahel, where the very large majority of rainfall events occur between June and September, during the West African monsoon. Rainfall is analysed with two complementary in-situ datasets: (i) daily rainfall series from 25 stations covering the period 1900-2007, and provided by the Direction Nationale de la Météorologie of Mali, and (ii) high-frequency rainfall data provided by a network of about 20 tipping bucket rain gauges, starting in 2005 - these rain gauges have been installed for the African Monsoon Multidisciplinary Analysis (AMMA), see Frappart et al. (2009) for additional information. The Gourma displays a particularly marked meridional gradient, with annual rainfall decreasing from about 500 mm at 14°N to 150 mm at 17.5°N. In line with previous studies focused on the Sahel, the area also displays a strong decadal variability, with the same succession of wet (1950-1969) and dry decades (1970-2007). The decrease of annual rainfall is explained by a reduction in the number of the rainy days in southern Gourma, but a decrease in both the number of rainy days and the daily rainfall in northern and central Gourma. This latter result contrasts with some studies focused on more southern areas. It may involves an influence of the distance from the inter-tropical discontinuity. The length of the rainy season has varied since the 1950s with two episodes of shorter rainy seasons: during the drought of the 1980s and also since 2000. However, this second episode is characterized by an increase in the daily rainfall, which suggests an intensification of rainfall events in the more recent years. High-frequency data show that most rainfall is produced by intense convective events whose characteristics are

  18. Contrasting behavior of oxygen and iron isotopes in banded iron formation revealed by in situ analysis

    NASA Astrophysics Data System (ADS)

    Beard, B.; Li, W.; Kita, N.; Valley, J. W.; Johnson, C.

    2012-12-01

    Banded iron formations (BIFs) record a period of dramatic secular change in Earth's geologic history, when abundant aqueous Fe(II) was removed from Archean and Proterozoic oceans by oxidation. BIFs are characterized by co-existing of quartz and iron minerals, including oxides and carbonates, and alternating iron-rich and iron-poor layers range from m to in situ measurement of O and Fe isotope ratios in minerals in BIFs provide valuable information about the origin of BIFs, as well as diagenetic and metamorphic effects that were superimposed on primary layering. We analyzed O and Fe isotope compositions of magnetite and hematite in BIFs from the 2.5 Ga Dales Gorge Member of the Brockman Iron Formation, Hamersley Group, Western Australia. Oxygen isotope ratios were measured by Secondary Ion Mass Spectrometry (SIMS), and Fe isotope ratios were measured by femtosecond Laser ablation Multi-Collector ICP-MS (fs-LA-MC-ICP-MS), with spatial resolutions of 15 mm (O) and 30-50 mm (Fe), and external precisions (2s) of +0.7 ‰ for δ18O and +0.2 ‰ for δ56Fe, respectively. Analysis of δ18O in iron oxides by SIMS employed special tuning with a 3kV primary beam to minimize orientation effects (Huberty et al. 2010 ). For hematite, δ18O values range from -7.1 ‰ to -0.6 ‰, with the majority of data clustering around -4.5 ‰, and δ56Fe values range from -0.50 ‰ to +1.53‰. Magnetite has a δ18O range of -5.6 ‰ to +5.6 ‰ and a δ56Fe range of -0.76 ‰ to +1.33 ‰. Notably, magnetite shows significant O isotope heterogeneity at a mineral grain scale, and the highest δ18O values were commonly measured from Si-rich (1-3 wt% SiO2) magnetite overgrowths or magnetite grains that have a recrystallization texture. In contrast, lowest δ18O values were measured from magnetite that contains less than 1 wt% SiO2. Individual magnetite grains can have up to 6 ‰ variation in δ18O values between low-Si core and Si-rich overgrowth. Iron

  19. In situ analysis of proteolipid protein gene transcripts during persistent Theiler's virus infection.

    PubMed

    Ozden, S; Aubert, C; Gonzalez-Dunia, D; Brahic, M

    1991-10-01

    SJL/J mice inoculated intracranially with the DA strain of Theiler's virus exhibit a persistent demyelinating disease of the central nervous system. To investigate the effect of persistent infection of oligodendrocytes on the expression of myelin genes, we analyzed the level of PLP mRNA in infected as well as uninfected oligodendrocytes. This study was performed at the single-cell level using the simultaneous detection of viral antigens by immunocytochemistry and PLP mRNAs by in situ hybridization with 35S-labeled oligonucleotide probes. Our data indicate that viral infection of oligodendrocytes reduces the level of PLP mRNA by about 80%.

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

    NASA Astrophysics Data System (ADS)

    Rüdiger, Julian; Bobrowski, Nicole; Hoffmann, Thorsten

    2015-04-01

    -mass spectrometry gives a limit of detection below 1 ng of bromine. The method was applied on volcanic gas plumes at Mt. Etna and Mt. Stromboli in Italy in July 2014 and on fumarolic gas emissions at Mt. Lastarria in Chile in November 2014. The results show significant amounts of the concerning bromine species (lower ppb range). Comprehensive data evaluation and comparison with results of impinger extraction with NaOH solution as well as chamber experiments are still in progress. References Bobrowski, N. and G. Giuffrida: Bromine monoxide / sulphur dioxide ratios in relation to volcanological observations at Mt. Etna 2006-2009. Solid Earth, 3, 433-445, 2012 Bobrowski, N., R. von Glasow, A. Aiuppa, S. Inguaggiato, I. Louban, O. W. Ibrahim and U. Platt: Reactive halogen chemistry in volcanic plumes. J. Geophys. Res., 112, 2007 Donovan A., V. Tsanev, C. Oppenheimer and M. Edmonds: Reactive halogens (BrO and OClO) detected in the plume of Soufrière Hills Volcano during an eruption hiatus. Geochem. Geophys. Geosyst., 15, 3346-3363, 2014 Huang, R.-J. and T. Hoffmann: A denuder-impinger system with in situ derivatization followed by gas chromatography-mass spectrometry for the determination of gaseous iodine-containing halogen species. Journal of Chromatography A, 1210, 135-141, 2008

  1. In-Situ XAFS Characterization for Nitriding Process of Silica Supported Nb Catalysts Under N2-H2 Gas

    SciTech Connect

    Ichikuni, Nobuyuki; Matsumoto, Hiroari; Haneishi, Hidenori; Shimazu, Shogo; Bando, Kyoko K.

    2007-02-02

    Fe-Nb/SiO2 catalyst was prepared from NbCl5 or peroxoniobic acid as Nb precursors. These precursor catalysts were nitrided by the TPR method under N2-H2 passage (without using NH3). Nb K-edge in-situ XAFS measurements were carried out during the nitriding process and revealed that the Nb species was more nitrided in the Fe-Nb/SiO2 catalyst prepared from peroxoniobic acid than in that prepared from NbCl5 as Nb precursor.

  2. In-Situ XAFS Characterization for Nitriding Process of Silica Supported Nb Catalysts Under N2-H2 Gas

    NASA Astrophysics Data System (ADS)

    Ichikuni, Nobuyuki; Matsumoto, Hiroari; Haneishi, Hidenori; Bando, Kyoko K.; Shimazu, Shogo

    2007-02-01

    Fe-Nb/SiO2 catalyst was prepared from NbCl5 or peroxoniobic acid as Nb precursors. These precursor catalysts were nitrided by the TPR method under N2-H2 passage (without using NH3). Nb K-edge in-situ XAFS measurements were carried out during the nitriding process and revealed that the Nb species was more nitrided in the Fe-Nb/SiO2 catalyst prepared from peroxoniobic acid than in that prepared from NbCl5 as Nb precursor.

  3. Tunable diode laser IR spectrometer for in situ measurements of the gas phase composition and particle size distribution of Titan's atmosphere

    NASA Technical Reports Server (NTRS)

    Webster, Christopher R.; Sander, Stanley P.; Beer, Reinhard; May, Randy D.; Knollenberg, Robert G.

    1990-01-01

    A new instrument, the Probe Infrared Laser Spectrometer (PIRLS), is described for in situ sensing of the gas composition and particle size distribution of Titan's atmosphere on the NASA/ESA Cassini mission. For gas composition measurements, several narrow-band (0.0001/cm) tunable lead-salt diode lasers operating near 80 K at selected mid-IR wavelengths are directed over a path length defined by a small reflector extending over the edge of the probe spacecraft platform; volume mixing ratios of 10 to the -9th should be measurable for several species of interest. A cloud-particle-size spectrometer using a diode laser source at 780 nm shares the optical path and deployed reflector; a combination of imaging and light scattering techniques is used to determine sizes of haze and cloud particles and their number density as a function of altitude.

  4. Pods: a Powder Delivery System for Mars In-situ Organic, Mineralogic and Isotopic Analysis Instruments

    NASA Technical Reports Server (NTRS)

    Saha, C. P.; Bryson, C. E.; Sarrazin, P.; Blake, D. F.

    2005-01-01

    Many Mars in situ instruments require fine-grained high-fidelity samples of rocks or soil. Included are instruments for the determination of mineralogy as well as organic and isotopic chemistry. Powder can be obtained as a primary objective of a sample collection system (e.g., by collecting powder as a surface is abraded by a rotary abrasion tool (RAT)), or as a secondary objective (e.g, by collecting drill powder as a core is drilled). In the latter case, a properly designed system could be used to monitor drilling in real time as well as to deliver powder to analytical instruments which would perform complementary analyses to those later performed on the intact core. In addition, once a core or other sample is collected, a system that could transfer intelligently collected subsamples of power from the intact core to a suite of analytical instruments would be highly desirable. We have conceptualized, developed and tested a breadboard Powder Delivery System (PoDS) intended to satisfy the collection, processing and distribution requirements of powder samples for Mars in-situ mineralogic, organic and isotopic measurement instruments.

  5. Multiscale in situ analysis of the role of dyskerin in lung cancer cells.

    PubMed

    Fernandez-Garcia, Ignacio; Marcos, Tamara; Muñoz-Barrutia, Arrate; Serrano, Diego; Pio, Ruben; Montuenga, Luis M; Ortiz-de-Solorzano, Carlos

    2013-02-01

    Dyskerin is one of the three subunits of the telomerase ribonucleoprotein (RNP) complex. Very little is known about the role of dyskerin in the biology of the telomeres in cancer cells. In this study, we use a quantitative, multiscale 3D image-based in situ method and several molecular techniques to show that dyskerin is overexpressed in lung cancer cell lines. Furthermore, we show that dyskerin expression correlates with telomere length both at the cell population level--cells with higher dyskerin expression have short telomeres--and at the single cell level--the shortest telomeres of the cell are spatially associated with areas of concentration of dyskerin proteins. Using this in vitro model, we also show that exogenous increase in dyskerin expression confers resistance to telomere shortening caused by a telomerase inactivating drug. Finally, we show that resistance is achieved by the recovery of telomerase activity associated with dyskerin. In summary, using a novel multiscale image-based in situ method, we show that, in lung cancer cell lines, dyskerin responds to continuous telomere attrition by increasing the telomerase RNP activity, which in turn provides resistance to telomere shortening.

  6. A novel in situ tool for the exposure and analysis of microorganisms in natural aquatic systems.

    PubMed

    Davis, Thomas A; Simon, Dana F; Hassler, Christel S; Wilkinson, Kevin J

    2009-11-01

    To evaluate the effects of contaminants or nutrient limitation in natural waters, it is often desirable to perform controlled exposures of organisms. While in situ exposures are routine for caged organisms or macrophytes, they are extremely difficult to perform for microorganisms, mainly due to difficulties in designing an exposure device that isolates the cells while allowing rapid equilibration with the external media. In this paper, a stirred underwater biouptake system (SUBS) based on the diffusion of chemicals across a semipermeable membrane housing a controlled population of microorganisms is reported. Cd diffusion through the semipermeable membrane was evaluated by voltammetry using a microelectrode. Comparison of stirred and unstirred solutions demonstrated a significantly increased diffusive flux in the presence of stirring. Lab tests using Chlamydomonas reinhardtii showed that diffusion across the semipermeable membrane was not limiting with respect to the biouptake of Cd. The SUBS device was field tested and the results of viability studies and trace metal biouptake by C. reinhardtii are reported. No diffusion limitation due to the SUBS was observed for Cd under the tested field conditions. The SUBS device was also shown to be useful for field exposures and subsequent measurements of trace metal uptake and viability. The results support the future use of the SUBS for the in situ measurement of phytochelatin/metallothionein production, photosynthetic efficiency, or reporter gene induction of controlled organisms.

  7. An immunohistochemical analysis of pseudomelanocytic nests mimicking melanoma in situ: report of 2 cases.

    PubMed

    Nicholson, Kimberly M; Gerami, Pedram

    2010-08-01

    Several case reports have discussed the difficulty in differentiating junctional pseudomelanocytic nests as a result of lichenoid inflammation from a true melanocytic neoplasm. Even immunohistochemistry can be misleading in these cases with both Melan-A and Mart-1 frequently resulting in false positivity as a result of nonspecific labeling of nonmelanocytic cells containing melanosomes. We present a series of 2 similar cases which were initially misdiagnosed as melanoma in situ likely as a result of Mart-1 positivity of the pseudomelanocytic nests. However, in our review, a significant lichenoid reaction was apparent at the dermal-epidermal junction. Staining with microphthalmia-associated transcription factor (MITF) showed a normal density of melanocytes along the dermal-epidermal junction and failed to uniformly label the Mart-1-positive pseudomelanocytic nests. In both patients, medications frequently resulting in fixed drug eruptions were identified, and a final diagnosis of fixed drug eruption was rendered in both cases. In light of these findings we suggest MITF is a more useful marker for evaluating lentiginous proliferations along the dermal-epidermal junction particularly when dealing with the differential diagnosis of lichenoid reaction with pseudomelanocytic nests versus melanoma in situ.

  8. A descriptive analysis of light vehicle-heavy vehicle interactions using in situ driving data.

    PubMed

    Hanowski, Richard J; Hickman, Jeffery S; Wierwille, Walter W; Keisler, Aysha

    2007-01-01

    Two recently completed on-road in situ (naturalistic) data collection efforts provided a large data set in which to conduct an examination of crashes, near-crashes, and crash-relevant conflicts (referred to as critical incidents throughout this paper) that occurred between light vehicles (LV) and heavy vehicles (HV). Video and non-video data collected during the two studies were used to characterize critical incidents that were recorded between LV and HV drivers. Across both studies, 210 LV-HV critical incidents were recorded. Of these, 78% were initiated by LV drivers, while the remaining 22% were initiated by HV drivers. Aggressive driving, on the part of the LV driver, was found to be the primary Contributing Factor for LV driver-initiated incidents. For HV driver-initiated incidents, the primary Contributing Factor was poor driving techniques. These results suggest that future efforts at addressing LV-HV interaction incidents should include focusing on aggressive LV drivers. Additionally, it is recommended that HV drivers might benefit from improved driver training that includes instruction on defensive driving skills. The in situ methodology provides an alternative to traditional crash databases, developed from police accident reports, for studying crash causation and driver behavior. PMID:16934736

  9. Better understanding of dissolution behaviour of amorphous drugs by in situ solid-state analysis using Raman spectroscopy.

    PubMed

    Savolainen, M; Kogermann, K; Heinz, A; Aaltonen, J; Peltonen, L; Strachan, C; Yliruusi, J

    2009-01-01

    Amorphous drugs have a higher kinetic solubility and dissolution rate than their crystalline counterparts. However, this advantage is lost if the amorphous form converts to the stable crystalline form during the dissolution as the dissolution rate will gradually change to that of the crystalline form. The purpose of this study was to use in situ Raman spectroscopy in combination with either partial least squares discriminant analysis (PLS-DA) or partial least squares (PLS) regression analysis to monitor as well as quantify the solid-phase transitions that take place during the dissolution of two amorphous drugs, indomethacin (IMC) and carbamazepine (CBZ). The dissolution rate was higher from amorphous IMC compared to the crystalline alpha- and gamma-forms. However, the dissolution rate started to slow down during the experiment. In situ Raman analysis verified that at that time point the sample started to crystallize to the alpha-form. Amorphous CBZ instantly started to crystallize upon contact with the dissolution medium. The transition from the amorphous form to CBZ dihydrate appears to go through the anhydrate form I. Based on the PLS analysis the amount of form I formed in the sample during the dissolution affected the dissolution rate. Raman spectroscopy combined with PLS-DA was also more sensitive to the solid-state changes than X-ray powder diffraction (XRPD) and was able to detect changes in the solid-state that could not be detected with XRPD. PMID:18590816

  10. In situ γ-ray spectrometry in the marine environment using full spectrum analysis for natural radionuclides.

    PubMed

    Androulakaki, E G; Kokkoris, M; Tsabaris, C; Eleftheriou, G; Patiris, D L; Pappa, F K; Vlastou, R

    2016-08-01

    The Full Spectrum Analysis approach was applied to obtain activity concentration estimations for in situ measurements in the marine environment. The 'standard spectra' were reproduced using the MCNP-CP code. In order to extract the activity concentrations, χ(2) minimization calculations were performed by implementing the MINUIT code. The method was applied to estimate the activity concentrations for measurements in the marine environment in three different test cases. The estimated activity concentrations were in good agreement with the experimentally derived ones within uncertainties.

  11. In situ γ-ray spectrometry in the marine environment using full spectrum analysis for natural radionuclides.

    PubMed

    Androulakaki, E G; Kokkoris, M; Tsabaris, C; Eleftheriou, G; Patiris, D L; Pappa, F K; Vlastou, R

    2016-08-01

    The Full Spectrum Analysis approach was applied to obtain activity concentration estimations for in situ measurements in the marine environment. The 'standard spectra' were reproduced using the MCNP-CP code. In order to extract the activity concentrations, χ(2) minimization calculations were performed by implementing the MINUIT code. The method was applied to estimate the activity concentrations for measurements in the marine environment in three different test cases. The estimated activity concentrations were in good agreement with the experimentally derived ones within uncertainties. PMID:27213807

  12. Husbandry Trace Gas Emissions from a Dairy Complex By Mobile in Situ and Airborne and Spaceborne Remote Sensing: A Comex Campaign Focus

    NASA Astrophysics Data System (ADS)

    Leifer, I.; Tratt, D. M.; Bovensmann, H.; Buckland, K. N.; Burrows, J. P.; Frash, J.; Gerilowski, K.; Iraci, L. T.; Johnson, P. D.; Kolyer, R.; Krautwurst, S.; Krings, T.; Leen, J. B.; Hu, C.; Melton, C.; Vigil, S. A.; Yates, E. L.; Zhang, M.

    2014-12-01

    Recent field study reviews on the greenhouse gas methane (CH4) found significant underestimation from fossil fuel industry and husbandry. The 2014 COMEX campaign seeks to develop methods to derive CH4 and carbon dioxide (CO2) from remote sensing data by combining hyperspectral imaging (HSI) and non-imaging spectroscopy (NIS) with in situ airborne and surface data. COMEX leverages synergies between high spatial resolution HSI column abundance maps and moderate spectral/spatial resolution NIS. Airborne husbandry data were collected for the Chino dairy complex (East Los Angeles Basin) by NIS-MAMAP, HSI-Mako thermal-infrared (TIR); AVIRIS NG shortwave IR (SWIR), with in situ surface mobile-AMOG Surveyor (AutoMObile greenhouse Gas)-and airborne in situ from a Twin Otter and the AlphaJet. AMOG Surveyor uses in situ Integrated Cavity Off Axis Spectroscopy (OA-ICOS) to measure CH4, CO2, H2O, H2S and NH3 at 5-10 Hz, 2D winds, and thermal anomaly in an adapted commuter car. OA-ICOS provides high precision and accuracy with excellent stability. NH3 and CH4 emissions were correlated at dairy size-scales but not sub-dairy scales in surface and Mako data, showing fine-scale structure and large variations between the numerous dairies in the complex (herd ~200,000-250,000) embedded in an urban setting. Emissions hotspots were consistent between surface and airborne surveys. In June, surface and MAMAP data showed a weak overall plume, while surface and Mako data showed a stronger plume in late (hotter) July. Multiple surface plume transects using NH3 fingerprinting showed East and then NE advection out of the LA Basin consistent with airborne data. Long-term trends were investigated in satellite data. This study shows the value of synergistically combined NH3 and CH4 remote sensing data to the task of CH4 source attribution using airborne and space-based remote sensing (IASI for NH3) and top of atmosphere sensitivity calculations for Sentinel V and Carbon Sat (CH4).

  13. In-situ and on-line measurement of gas flux at a hydrocarbon seep from the northern South China Sea

    NASA Astrophysics Data System (ADS)

    Di, Pengfei; Feng, Dong; Chen, Duofu

    2014-06-01

    Natural hydrocarbon seeps in the marine environment are important sources of methane and other greenhouse gases to the ocean and the atmosphere. Accurate quantification of methane flux at hydrocarbon seeps is therefore necessary to evaluate their influence on the global methane budget and climate change. Hydrocarbon seeps on the seabed produce a near-shore gas bubble zone along the shallow western coast of Hainan Island, northern South China Sea. An in-situ and on-line gas flux measuring device was deployed over a hydrocarbon seep to quantify the gas flux by equal volume exchange venting from the seabed offshore of Ledong Town, Hainan Island, over 19 days. The physiochemical parameters and the dissolved methane concentration of the bottom water at the hydrocarbon seep were also measured. The gas flux from the hydrocarbon seep varied from 22 to 77 l/day with the tidal period and was strongly negatively correlated with water depth. The flux data from the seep suggests that the variation in hydrostatic pressure induced by tidal forcing and ocean swell may control the variation of the gas flux. The bottom water dissolved methane concentration, ranging from 26 to 74 nmol/L, was negatively correlated with temperature and water depth at the seabed and positively with the gas flux. The total gas volume released from the hydrocarbon seep was 30.5 m3 for the 19-day period, providing an estimated gas flux of 600 m3/yr. The 120 known hydrocarbon seeps along the eastern edge of the Yinggehai Basin could vent a large quantity of methane from the seafloor, which suggests that hydrocarbon seeps on the continental margin of the northern South China Sea may be an important natural source of methane to the atmosphere.

  14. Uncertainty Analysis of in situ Ocean Color Radiometry for the Vicarious Calibration of Ocean Color Satellite Sensors

    NASA Astrophysics Data System (ADS)

    Johnson, B.; Clark, D.; Feinholz, M.; Flora, S.; Franz, B.; Houlihan, T.; Mueller, J. A.; Parr, A. C.; Voss, K. J.; Yarbrough, M.

    2011-12-01

    Substantial effort has been invested by NASA to create and maintain a long-term, consistent, and calibrated time series of ocean color radiometry over multiple missions and satellite sensors. This is a very difficult measurement problem because the water-leaving radiance is a small fraction of the total radiance measured by the satellite sensor. As a result, the SI traceability of ocean color radiometric values relies completely on a vicarious calibration approach utilizing reference oceanic sites. A robust and rigorous uncertainty analysis of this data set is outstanding. Broadly speaking, there are three aspects to the uncertainty budget for the long-term time series of the global ocean color radiometric data set: the in situ radiometric time series, the in situ to satellite match-up time series for determination of the vicarious calibration gain coefficients, and the global, satellite derived values for water-leaving radiances (or remote sensing reflectances). The uncertainty budget has elements attributed to sensor characterization functions (which change in time), natural variability, and the veracity and efficacy of the measurement equations (including models and algorithms) that describe the complete methodology. We have recently undertaken a rigorous analysis of uncertainty of the global ocean color radiometric time series data set, emphasizing the in situ uncertainties and their impact on the ocean color time series. Our technical approach is to formulate and analyze measurement equations that model the relationships between the values of the measured quantities and the resulting uncertainties, thus establishing traceability of the values of the MOBY results to stated reference values. Uncertainty estimates are quantitative data products in and of themselves - documentation of discrepancies between results and associating these values with uncertainties is not a valid or sufficient approach. We will review the MOBY data set, explain our uncertainty model

  15. Towards a cellular multi-parameter analysis platform: fluorescence in situ hybridization (FISH) on microhole-array chips.

    PubMed

    Kurz, Christian M; Moosdijk, Stefan V D; Thielecke, Hagen; Velten, Thomas

    2011-01-01

    Highly-sensitive analysis systems based on cellular multi-parameter are needed in the diagnostics. Therefore we improved our previously developed chip platform for another additional analysis method, the fluorescence in situ hybridization. Fluorescence in situ hybridization (FISH) is a technique used in the diagnostics to determine the localization and the presence or absence of specific DNA sequence. To improve this labor- and cost-intensive method, we reduced the assay consumption by a factor of 5 compared to the standard protocol. Microhole chips were used for making the cells well addressable. The chips were fabricated by semiconductor technology on the basis of a Silicon wafer with a thin deposited silicon nitride layer (Si(3)N(4)). Human retina pigment epithelia (ARPE-19) cells were arrayed on 5-μm holes of a 35 × 35 microhole-array by a gently negative differential pressure of around 5 mbar. After 3 hours of incubation the cells were attached to the chip and the FISH protocol was applied to the positioned cells. A LabView software was developed to simplify the analysis. The software automatically counts the number of dots (positive labeled chromosome regions) as well as the distance between adjacent dots. Our developed platform reduces the assay consumption and the labor time. Furthermore, during the 3 hours of incubation non-invasive or minimal-invasive methods like Raman- and impedance-spectroscopy can be applied. PMID:22256298

  16. Fast in situ phase and stress analysis during laser surface treatment: a synchrotron x-ray diffraction approach.

    PubMed

    Kostov, V; Gibmeier, J; Wilde, F; Staron, P; Rössler, R; Wanner, A

    2012-11-01

    An in situ stress analysis by means of synchrotron x-ray diffraction was carried out during laser surface hardening of steel. A single exposure set-up that based on a special arrangement of two fast silicon strip line detectors was established, allowing for fast stress analysis according to the sin(2)ψ x-ray analysis method. For the in situ experiments a process chamber was designed and manufactured, which is described in detail. First measurements were carried out at the HZG undulator imaging beamline (IBL, beamline P05) at the synchrotron storage ring PETRA III, DESY, Hamburg (Germany). The laser processing was carried out using a 6 kW high power diode laser system. Two different laser optics were compared, a Gaussian optic with a focus spot of ø 3 mm and a homogenizing optic with a rectangular spot dimension of 8 × 8 mm(2). The laser processing was carried out using spot hardening at a heating-/cooling rate of 1000 K/s and was controlled via pyrometric temperature measurement using a control temperature of 1150 °C. The set-up being established during the measuring campaign allowed for this first realization data collection rates of 10Hz. The data evaluation procedure applied enables the separation of thermal from elastic strains and gains unprecedented insight into the laser hardening process.

  17. Thermodynamics of gas-metal-slag equilibria for applications in in situ and ex situ vitrification melts

    SciTech Connect

    Miller, R.L.; Reimann, G.A.

    1993-05-01

    An equilibrium thermodynamic model for melting mixed waste was evaluated using the STEPSOL computer code. STEPSOL uses free energy minimization techniques to predict equilibrium composition from input species and user selected species in the output. The model assumes equilibrium between gas, slag, and metallic phases. Input for the model was developed using compositional data from Pit 9 of the Subsurface Disposal Area at the Idaho National Engineering Laboratory. Thermodynamic data were primarily from compilations published by the US Government. The results of model evaluation indicate that the amount of plutonium chloride or plutonium oxyhydroxide that would be evaporated into the vapor phase would be minor. Relatively more uranium chloride and uranium oxyhydroxide would be vaporized. However, a hazards analysis was not part of the present task. Minor amounts of plutonium and uranium would be reduced to the metallic state, but these amounts should alloy with the iron-chromium-nickel metallic phase. The vast majority of the plutonium and uranium are in the slag phase as oxides. Results of the calculations show that silica and silicates dominate the products and that the system is very reducing. The major gases are carbon monoxide and hydrogen, with lesser amounts of carbon dioxide and water. High vapor pressure metals are considered but were not analyzed using STEPSOL. STEPSOL does not make predictions of distribution of species between phases.

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

    NASA Astrophysics Data System (ADS)

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

    2000-07-01

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

  19. In situ analysis of texture development from sinusoidal stress at high pressure and temperature

    SciTech Connect

    Li, Li; Weidner, Donald J.

    2015-12-15

    Here, we present a new experimental protocol to investigate the relationship between texture, plastic strain, and the mechanisms of plastic deformation at high pressure and temperature. The method utilizes synchrotron X-ray radiation as the probing tool, coupled with a large-volume high pressure deformation device (D-DIA). The intensity of X-ray diffraction peaks within the spectrum of the sample is used for sampling texture development in situ. The unique feature of this study is given by the sinusoidal variation of the intensity when a sinusoidal strain is applied to the sample. For a sample of magnesium oxide at elevated pressure and temperature, we demonstrate observations that are consistent with elasto-plastic models for texture development and for diffraction-peak measurements of apparent stress. The sinusoidal strain magnitude was 3%.

  20. Fluorescence in situ hybridization analysis of formalin fixed paraffin embedded tissues, including tissue microarrays.

    PubMed

    Summersgill, Brenda M; Shipley, Janet M

    2010-01-01

    Formalin fixed paraffin embedded (FFPE) material is frequently the most convenient readily available source of diseased tissue, including tumors. Multiple cores of FFPE material are being used increasingly to construct tissue microarrays (TMAs) that enable simultaneous analyses of many archival samples. Fluorescence in situ hybridization (FISH) is an important approach to analyze FFPE material for specific genetic aberrations that may be associated with tumor types or subtypes, cellular morphology, and disease prognosis. Annealing, or hybridization of labeled nucleic acid sequences, or probes, to detect and locate one or more complementary nucleic acid sequences within fixed tissue sections allows the detection of structural (translocation/inversion) and numerical (deletion/gain) aberrations and their localization within tissues. The robust protocols described include probe preparation, hybridization, and detection and take 2-3 days to complete. A protocol is also described for the stripping of probes for repeat FISH in order to maximize the use of scarce tissue resources.

  1. MCNP ESTIMATE OF THE SAMPLED VOLUME IN A NON-DESTRUCTIVE IN SITU SOIL CARBON ANALYSIS.

    SciTech Connect

    WIELOPOLSKI, L.; DIOSZEGI, I.; MITRA, S.

    2004-05-03

    Global warming, promoted by anthropogenic CO{sub 2} emission into the atmosphere, is partially mitigated by the photosynthesis processes of the terrestrial echo systems that act as atmospheric CO{sub 2} scrubbers and sequester carbon in soil. Switching from till to no till soils management practices in agriculture further augments this process. Carbon sequestration is also advanced by putting forward a carbon ''credit'' system whereby these can be traded between CO{sub 2} producers and sequesters. Implementation of carbon ''credit'' trade will be further promulgated by recent development of a non-destructive in situ carbon monitoring system based on inelastic neutron scattering (INS). Volumes and depth distributions defined by the 0.1, 1.0, 10, 50, and 90 percent neutron isofluxes, from a point source located at either 5 or 30 cm above the surface, were estimated using Monte Carlo calculations.

  2. In situ analysis of texture development from sinusoidal stress at high pressure and temperature.

    PubMed

    Li, Li; Weidner, Donald J

    2015-12-01

    Here, we present a new experimental protocol to investigate the relationship between texture, plastic strain, and the mechanisms of plastic deformation at high pressure and temperature. The method utilizes synchrotron X-ray radiation as the probing tool, coupled with a large-volume high pressure deformation device (D-DIA). The intensity of X-ray diffraction peaks within the spectrum of the sample is used for sampling texture development in situ. The unique feature of this study is given by the sinusoidal variation of the intensity when a sinusoidal strain is applied to the sample. For a sample of magnesium oxide at elevated pressure and temperature, we demonstrate observations that are consistent with elasto-plastic models for texture development and for diffraction-peak measurements of apparent stress. The sinusoidal strain magnitude was 3%. PMID:26724072

  3. Spatially resolved quantitative in-situ phase analysis of a self-leveling compound

    SciTech Connect

    Seifert, Severin; Neubauer, Juergen; Goetz-Neunhoeffer, Friedlinde

    2012-07-15

    The development of the crystalline microstructure of a hydrating self-leveling compound (SLC) was analyzed using a two-dimensional XRD (GADDS). The application of non-destructive micro-diffraction with the GADDS, combined with a custom-made sample holder, made it possible to carry out position-sensitive in-situ measurements of a Calcium-Aluminate-Cement-(CAC)-dominated SLC. Different substrates were used in the measurement procedures so as to acquire data regarding the influence of the properties of the ground surface on the process of hydration. The results show that the crystalline microstructure is strongly affected by the availability of free water. The strongly vertically-fluctuating water-content of the hydrating mortar, which is mainly influenced by outside conditions, has a very significant effect upon the resulting ettringite content. This fact is also reflected in the resulting microstructure of the cured SLC.

  4. Phylogenetic analysis and in situ identification of bacteria in activated sludge.

    PubMed Central

    Snaidr, J; Amann, R; Huber, I; Ludwig, W; Schleifer, K H

    1997-01-01

    The bacterial community structure of activated sludge of a large municipal wastewater treatment plant was investigated by use of the rRNA approach. Almost-full-length genes coding for the small-subunit rRNA (rDNA) were amplified by PCR and subsequently cloned into the pGEM-T vector. Clones were screened by dot blot hybridization with group-specific oligonucleotide probes. The phylogenetic affiliations of clones were compared with the results obtained with the original sample by in situ hybridization with fluorescently labeled, rRNA-targeted oligonucleotide probes and found to be in general agreement. Twenty-five 16S rDNA clones were fully sequenced, 11 were almost fully (> 80%) sequenced, and 27 were partially sequenced. By comparative sequence analyses, the majority of the examined clones (35 of 67) could be affiliated with the beta subclass of the class Proteobacteria. The gamma and alpha subclasses of Proteobacteria were represented by 13 and 4 clones, respectively. Eight clones grouped with the epsilon group of Proteobacteria, and five clones grouped with gram-positive bacteria with a low DNA G+C content. The 16S rDNA of two clones showed similarity with 16S rDNA genes of members of the phyla Chlamydiae and Planctomyces. 16S rRNA-targeted oligonucleotide probes were designed and used for the enumeration of the respective bacteria. Interestingly, potentially pathogenic representatives of the genus Arcobacter were present in significant numbers (4%) in the activated sludge sample examined. Pairs of probes targeted to the 5' and 3' regions were used for detection of chimeric sequences by in situ hybridization. Two clones could be identified as chimera by applying such a pair of probes. PMID:9212435

  5. Simazine biodegradation in soil: analysis of bacterial community structure by in situ hybridization.

    PubMed

    Caracciolo, Anna Barra; Grenni, Paola; Ciccoli, Roberto; Di Landa, Giuseppe; Cremisini, Carlo

    2005-09-01

    Pesticide and nitrate contamination of soil and groundwater from agriculture is an environmental and public health concern worldwide. Simazine, 6-chloro-N2,N4-diethyl-1,3,5-triazine-2,4-diamine, is a triazine herbicide used in agriculture for selective weed control with several types of crops and it is frequently applied to soils receiving N-fertilizers. Degradation experiments were performed in the laboratory to assess whether the biodegradation of simazine in soil may be influenced by the presence of urea. Simazine degradation rates under different experimental conditions (presence/absence of urea, microbiologically active/sterilized soil) were assessed together with the formation, degradation and transformation of its main metabolites in soil. Simazine degradation was affected by the presence of urea, in terms both of a smaller half-life (t(1/2)) and of a higher amount of desethyl-simazine formed. The soil bacterial community was also studied. Microbial abundances were determined by epifluorescence direct counting. Moreover in situ hybridization with rRNA-targeted fluorescent oligonucleotide probes was used to analyze the bacterial community structure. Fluorescent in situ hybridization (FISH) was used to detect specific groups of bacteria such as the alpha,beta,gamma-subdivisions of Proteobacteria, Gram-positive bacteria with a high G + C DNA content, Planctomycetes, Betaproteobacterial ammonia-oxidizing bacteria and nitrifying bacteria. The presence of the herbicide and/or urea affected the bacterial community structure, showing that FISH is a valuable tool for determining the response of bacterial populations to different environmental conditions.

  6. Conversion of propan-2-ol on zeolites LaNaY and HY investigated by gas chromatography and in situ MAS NMR spectroscopy under continuous-flow conditions

    SciTech Connect

    Hunger, M.; Horvath, T.

    1997-04-01

    The conversion of propan-2-ol on zeolites HY and LaNaY has been investigated by gas chromatography (GC) and in situ {sup 1}H and {sup 13}C MAS NMR spectroscopy under continuous-flow conditions using a new MAS NMR microreactor with cylindrical catalyst bed. At reaction temperatures of T = 373 K and T = 393 K a propan-2-ol conversion of 50 and 100%, respectively, and the formation of propene, diisopropyl. ether, and small amounts of acetone was determined by GC. Applying in situ {sup 1}H and {sup 13}C MAS NMR spectroscopy, the initial step of the reaction was found to be the physisorption of propan-2-ol on Bronsted acid sites. A formation of isopropoxy species could be excluded by {sup 13}C MAS NMR spectroscopy. {sup 1}H MAS NMR spectroscopy indicated that the Bronsted acid sites of the zeolites LaNaY and HY were hydrated by water molecules in the first part of the induction period. These water molecules were formed in result of the propan-2-ol dehydration. The strong low-field shift of the {sup 1}H MAS NMR signals of the hydrated Bronsted acid sites is due to a partial protonation of adsorbed water molecules. At T = 393 K, a significant {sup 13}C MAS NMR signal of strongly bonded acetone molecules appeared at 220 ppm in the spectra of zeolites LaNaY and HY. As demonstrated by propan-2-ol conversion on a partially dealuminated zeolite HY, this by-reaction is promoted by extra-framework aluminium species. The formation of coke precursors which caused {sup 13}C MAS NMR signals at 10-50 ppm is explained by an oligomerization of propene. In situ {sup 13}C MAS NMR experiments carried out under a continuous flow of propene showed that the above-mentioned coke precursors are also formed on partially rehydrated zeolite HY. 25 refs., 14 figs., 1 tab.

  7. In situ measurements of radiofrequency exposure levels in Greece from 2008 to 2013: a multi-parametric annual analysis.

    PubMed

    Christopoulou, Maria; Karabetsos, Efthymios

    2015-04-01

    From 2008 through 2013, more than 6,000 in situ frequency selective audits, in the proximity of base stations, were conducted throughout Greece by the Greek Atomic Energy Commission (EEAE), in order to verify exposure limit compliance. EEAE is the competent national authority for protection of the general public against artificially produced non-ionizing radiation. This paper presents the first post processing and multi-parametric year statistical analysis of in situ measurement data corresponding to 4,705 audits in the whole country, compared to general public exposure levels, according to Greek legislation. The aim is to derive nationwide conclusions for the characterization of general public exposure to radiofrequency electromagnetic fields, during the last 6 years. The results' presentation includes electric field exposure ratios referring to broadband and frequency selective measurements at the highest exposure measurement point. Statistical analysis is applied to assist the data presentation and evaluation, based on selected criteria and classification parameters, including: (i) year (2008-2013); (ii) environment (urban/suburban/rural); (iii) frequency bands of selected common telecommunication services (e.g., TV, FM, GSM, DCS, UMTS); and (iv) number of service providers installed at the same site. In general, measurement results revealed that the vast majority of exposure values were below reference levels for general public exposure, as defined by Greek legislation. Data are constantly updated with the latest measurements, including emerging wireless technologies. PMID:25726724

  8. In situ measurements of radiofrequency exposure levels in Greece from 2008 to 2013: a multi-parametric annual analysis.

    PubMed

    Christopoulou, Maria; Karabetsos, Efthymios

    2015-04-01

    From 2008 through 2013, more than 6,000 in situ frequency selective audits, in the proximity of base stations, were conducted throughout Greece by the Greek Atomic Energy Commission (EEAE), in order to verify exposure limit compliance. EEAE is the competent national authority for protection of the general public against artificially produced non-ionizing radiation. This paper presents the first post processing and multi-parametric year statistical analysis of in situ measurement data corresponding to 4,705 audits in the whole country, compared to general public exposure levels, according to Greek legislation. The aim is to derive nationwide conclusions for the characterization of general public exposure to radiofrequency electromagnetic fields, during the last 6 years. The results' presentation includes electric field exposure ratios referring to broadband and frequency selective measurements at the highest exposure measurement point. Statistical analysis is applied to assist the data presentation and evaluation, based on selected criteria and classification parameters, including: (i) year (2008-2013); (ii) environment (urban/suburban/rural); (iii) frequency bands of selected common telecommunication services (e.g., TV, FM, GSM, DCS, UMTS); and (iv) number of service providers installed at the same site. In general, measurement results revealed that the vast majority of exposure values were below reference levels for general public exposure, as defined by Greek legislation. Data are constantly updated with the latest measurements, including emerging wireless technologies.

  9. A generalized method for high throughput in-situ experiment data analysis: An example of battery materials exploration

    NASA Astrophysics Data System (ADS)

    Aoun, Bachir; Yu, Cun; Fan, Longlong; Chen, Zonghai; Amine, Khalil; Ren, Yang

    2015-04-01

    A generalized method is introduced to extract critical information from series of ranked correlated data. The method is generally applicable to all types of spectra evolving as a function of any arbitrary parameter. This approach is based on correlation functions and statistical scedasticity formalism. Numerous challenges in analyzing high throughput experimental data can be tackled using the herein proposed method. We applied this method to understand the reactivity pathway and formation mechanism of a Li-ion battery cathode material during high temperature synthesis using in-situ high-energy X-ray diffraction. We demonstrate that Pearson's correlation function can easily unravel all major phase transition and, more importantly, the minor structural changes which cannot be revealed by conventionally inspecting the series of diffraction patterns. Furthermore, a two-dimensional (2D) reactivity pattern calculated as the scedasticity along all measured reciprocal space of all successive diffraction pattern pairs unveils clearly the structural evolution path and the active areas of interest during the synthesis. The methods described here can be readily used for on-the-fly data analysis during various in-situ operando experiments in order to quickly evaluate and optimize experimental conditions, as well as for post data analysis and large data mining where considerable amount of data hinders the feasibility of the investigation through point-by-point inspection.

  10. In Situ Void Fraction and Gas Volume in Hanford Tank 241-SY-101 as Measured with the Void Fraction Instrument

    SciTech Connect

    CW Stewart; G Chen; JM Alzheimer; PA Meyer

    1998-11-10

    The void fraction instrument (WI) was deployed in Tank 241-SY-101 three times in 1998 to confm and locate the retained gas (void) postulated to be causing the accelerating waste level rise observed since 1995. The design, operation, and data reduction model of the WI are described along with validation testing and potential sources of uncertainty. The test plans, field observations and void measurements are described in detail, including the total gas volume calculations and the gas volume model. Based on 1998 data, the void fraction averaged 0.013 i 0.001 in the mixed slurry and 0.30 ~ 0.04 in the crust. This gives gas volumes (at standard pressure and temperature) of 87 t 9 scm in the slurry and 138 ~ 22 scm in the crust for a total retained gas volume of221 *25 scm. This represents an increase of about 74 scm in the crust and a decrease of about 34 scm in the slurry from 1994/95 results. The overall conclusion is that the gas retention is occurring mainly in the crust layer and there is very little gas in the mixed slurry and loosely settled layers below. New insights on crust behavior are also revealed.

  11. In-situ Isotopic Analysis at Nanoscale using Parallel Ion Electron Spectrometry: A Powerful New Paradigm for Correlative Microscopy

    PubMed Central

    Yedra, Lluís; Eswara, Santhana; Dowsett, David; Wirtz, Tom

    2016-01-01

    Isotopic analysis is of paramount importance across the entire gamut of scientific research. To advance the frontiers of knowledge, a technique for nanoscale isotopic analysis is indispensable. Secondary Ion Mass Spectrometry (SIMS) is a well-established technique for analyzing isotopes, but its spatial-resolution is fundamentally limited. Transmission Electron Microscopy (TEM) is a well-known method for high-resolution imaging down to the atomic scale. However, isotopic analysis in TEM is not possible. Here, we introduce a powerful new paradigm for in-situ correlative microscopy called the Parallel Ion Electron Spectrometry by synergizing SIMS with TEM. We demonstrate this technique by distinguishing lithium carbonate nanoparticles according to the isotopic label of lithium, viz. 6Li and 7Li and imaging them at high-resolution by TEM, adding a new dimension to correlative microscopy. PMID:27350565

  12. In-situ Isotopic Analysis at Nanoscale using Parallel Ion Electron Spectrometry: A Powerful New Paradigm for Correlative Microscopy.

    PubMed

    Yedra, Lluís; Eswara, Santhana; Dowsett, David; Wirtz, Tom

    2016-01-01

    Isotopic analysis is of paramount importance across the entire gamut of scientific research. To advance the frontiers of knowledge, a technique for nanoscale isotopic analysis is indispensable. Secondary Ion Mass Spectrometry (SIMS) is a well-established technique for analyzing isotopes, but its spatial-resolution is fundamentally limited. Transmission Electron Microscopy (TEM) is a well-known method for high-resolution imaging down to the atomic scale. However, isotopic analysis in TEM is not possible. Here, we introduce a powerful new paradigm for in-situ correlative microscopy called the Parallel Ion Electron Spectrometry by synergizing SIMS with TEM. We demonstrate this technique by distinguishing lithium carbonate nanoparticles according to the isotopic label of lithium, viz. (6)Li and (7)Li and imaging them at high-resolution by TEM, adding a new dimension to correlative microscopy. PMID:27350565

  13. In-situ Isotopic Analysis at Nanoscale using Parallel Ion Electron Spectrometry: A Powerful New Paradigm for Correlative Microscopy

    NASA Astrophysics Data System (ADS)

    Yedra, Lluís; Eswara, Santhana; Dowsett, David; Wirtz, Tom

    2016-06-01

    Isotopic analysis is of paramount importance across the entire gamut of scientific research. To advance the frontiers of knowledge, a technique for nanoscale isotopic analysis is indispensable. Secondary Ion Mass Spectrometry (SIMS) is a well-established technique for analyzing isotopes, but its spatial-resolution is fundamentally limited. Transmission Electron Microscopy (TEM) is a well-known method for high-resolution imaging down to the atomic scale. However, isotopic analysis in TEM is not possible. Here, we introduce a powerful new paradigm for in-situ correlative microscopy called the Parallel Ion Electron Spectrometry by synergizing SIMS with TEM. We demonstrate this technique by distinguishing lithium carbonate nanoparticles according to the isotopic label of lithium, viz. 6Li and 7Li and imaging them at high-resolution by TEM, adding a new dimension to correlative microscopy.

  14. Evidence for in-situ metabolic activity in ice sheets based on anomalous trace gas records from the Vostok and other ice cores

    NASA Astrophysics Data System (ADS)

    Sowers, T.

    2003-04-01

    Measurements of trace gas species in ice cores are the primary means for reconstructing the composition of the atmosphere. The longest such record comes from the Vostok core taken from the central portion of the East Antarctic ice sheet [Petit et al., 1999]. In general, the trace gas records from Vostok are utilized as the reference signal when correlating trace gas measurements from other ice cores. The underlying assumption implicit in such endeavors is that the bubbles recovered from the ice cores record the composition of the atmosphere at the time the bubbles were formed. Another implicit assumption is that the composition of the bubbles has not been compromised by the extremely long storage periods within the ice sheet. While there is ample evidence that certain trace gas records (e.g. CO2 and CH4) have probably not been compromised, anomalous nitrous oxide (N2O) measurements from the penultimate glacial termination at Vostok are consistent with in-situ (N2O) production [Sowers, 2001]. In general, trace gas measurements from high altitude tropical/temperate glaciers are higher than expected based on contemporaneous measurements from polar cores. Measurements spanning the last 25kyr from the Sajama ice core from central Bolivia (18oS, 69oW, 6542masl), for example, were 1X-5X higher than contemporaneous values recorded in polar ice cores [Campen et al., 2003]. While other physical factors (like temperature/melting) may contribute to the elevated trace gas levels at these sites, the most likely explanation involves the accumulation of in-situ metabolic trace gas byproducts. Stable isotope measurements provide independent information for assessing the origin of the elevated trace gas levels in select samples. For the penultimate glacial termination at Vostok, the anomalous (N2O) values carry high δ15Nbulk and low δ18Obulk values that would be predicted if the added (N2O) was associated with in-situ nitrification. At Sajama, low δ13CH4 values observed during

  15. In situ cryopreservation of human embryonic stem cells in gas-permeable membrane culture cassettes for high post-thaw yield and good manufacturing practice.

    PubMed

    Amps, K J; Jones, M; Baker, D; Moore, H D

    2010-06-01

    The development of efficient and robust methods for the cryopreservation of human embryonic stem cells (hESCs) is important for the production of master and working cell banks for future clinical applications. Such methods must meet requirements of good manufacturing practice (GMP) and maintain genetic stability of the cell line. We investigated the culture of four Shef hESC lines in gas permeable 'culture cassettes' which met GMP compliance. hESCs adhered rapidly to the membrane and colonies displayed good proliferation and expansion. After 5-7 days of culture, hESCs were cryopreserved in situ using 10% dimethyl sulphoxide in foetal calf serum at approximately 1 degrees C/min. This method was compared with a control of standard flask culture and cryopreservation in vials. Post-thaw cassette culture displayed relative proliferation ratios (fold increase above flask/cryovial culture) of 114 (Shef 4), 8.2 (Shef 5), 195 (shef 6) and 17.5 (Shef 7). The proportion of cells expressing pluripotency markers after cryopreservation was consistently greater in cassette culture than for the control with the markers SSEA3 and SSEA4 exhibiting a significant increase (P> or =0.05). The efficiency of cell line culture in cassette was associated with the overall passage number of the cell line. The procedure enables cryopreservation of relatively large quantities of hESCs in situ, whilst returning high yields of viable, undifferentiated stem cells, thereby increasing capacity to scale up with greater efficacy.

  16. Pulsed ion beam surface analysis (PIBSA) as a means of in-situ real-time analysis of thin films during growth

    SciTech Connect

    Krauss, A.R; Lamich, G.J.; Gruen, D.M.; Lin, Y. |; Chang, R.P.H.; Auciello, O.; Schultz, J.A.

    1993-10-01

    Low energy (5-15 keV) pulsed ion beam surface analysis (PIBSA) comprises several different surface spectroscopies which provide a wide range of information relevant to growth of single and multi-component semiconductor, metal and metal oxide thin f@ and layered structures. Ion beam methods have not been widely used as an in-situ monitor of thin film growth. PIBSA has been developed as a non-destructive, in-situ, real-time probe of thin film composition and structure which does not physically interfere with deposition. Several PIBSA versions are exceptionally surface-specific, yet can yield high resolution data at ambient pressures in excess of 1 m Torr (4-5 orders of magnitude higher than conventional surface analytic methods). Therefore, PIBSA is ideal for studying ultra-thin layers and atomically abrupt interfaces. PIBSA instrumentation designed for use as an in-situ, real-time monitor of growth processes for single and multi-component thin films and layered structures is described. Representative data are shown for in-situ analysis of Pb and Zr layers at room temperature and high vacuum, as well as under conditions for growth of PZT perovskite films on MgO and RuO{sub 2} substrates.

  17. Application of the 15N gas-flux method for measuring in situ N2 and N2O fluxes due to denitrification in natural and semi-natural terrestrial ecosystems and comparison with the acetylene inhibition technique

    NASA Astrophysics Data System (ADS)

    Sgouridis, Fotis; Stott, Andrew; Ullah, Sami

    2016-03-01

    Soil denitrification is considered the most un-constrained process in the global N cycle due to uncertain in situ N2 flux measurements, particularly in natural and semi-natural terrestrial ecosystems. 15N tracer approaches can provide in situ measurements of both N2 and N2O simultaneously, but their use has been limited to fertilized agro-ecosystems due to the need for large 15N additions in order to detect 15N2 production against the high atmospheric N2. For 15N-N2 analyses, we have used an "in-house" laboratory designed and manufactured N2 preparation instrument which can be interfaced to any commercial continuous flow isotope ratio mass spectrometer (CF-IRMS). The N2 prep unit has gas purification steps and a copper-based reduction furnace, and allows the analysis of small gas injection volumes (4 µL) for 15N-N2 analysis. For the analysis of N2O, an automated Tracegas Preconcentrator (Isoprime Ltd) coupled to an IRMS was used to measure the 15N-N2O (4 mL gas injection volume). Consequently, the coefficient of variation for the determination of isotope ratios for N2 in air and in standard N2O (0.5 ppm) was better than 0.5 %. The 15N gas-flux method was adapted for application in natural and semi-natural land use types (peatlands, forests, and grasslands) by lowering the 15N tracer application rate to 0.04-0.5 kg 15N ha-1. The minimum detectable flux rates were 4 µg N m-2 h-1 and 0.2 ng N m-2 h-1 for the N2 and N2O fluxes respectively. Total denitrification rates measured by the acetylene inhibition technique in the same land use types correlated (r = 0.58) with the denitrification rates measured under the 15N gas-flux method, but were underestimated by a factor of 4, and this was partially attributed to the incomplete inhibition of N2O reduction to N2, under a relatively high soil moisture content, and/or the catalytic NO decomposition in the presence of acetylene. Even though relatively robust for in situ denitrification measurements, methodological

  18. Determining in-situ thermal conductivity of coarse textured materials through numerical analysis of thermal

    NASA Astrophysics Data System (ADS)

    Saito, H.; Hamamoto, S.; Moldrup, P.; Komatsu, T.

    2013-12-01

    Ground source heat pump (GSHP) systems use ground or groundwater as a heat/cooling source, typically by circulating anti-freezing solution inside a vertically installed closed-loop tube known as a U-tube to transfer heat to/from the ground. Since GSHP systems are based on renewable energy and can achieve much higher coefficient of performance (COP) than conventional air source heat pump systems, use of GSHP systems has been rapidly increasing worldwide. However, environmental impacts by GSHP systems including thermal effects on subsurface physical-chemical and microbiological properties have not been fully investigated. To rigorously assess GSHP impact on the subsurface environment, ground thermal properties including thermal conductivity and heat capacity need to be accurately characterized. Ground thermal properties were investigated at two experimental sites at Tokyo University of Agriculture and Technology (TAT) and Saitama University (SA), both located in the Kanto area of Japan. Thermal properties were evaluated both by thermal probe measurements on boring core samples and by performing in-situ Thermal Response Tests (TRT) in 50-80 m deep U-tubes. At both TAT and SU sites, heat-pulse probe measurements gave unrealistic low thermal conductivities for coarse textured materials (dominated by particles > 75 micrometers). Such underestimation can be partly due to poor contact between probe and porous material and partly to markedly decreasing sample water content during drilling, carrying, and storing sandy/gravelly samples. A more reliable approach for estimating in-situ thermal conductivity of coarse textured materials is therefore needed, and may be based on the commonly used TRT test. However, analyses of TRT data is typically based on Kelvin's line source model and provides an average (effective) thermal property for the whole soil profile around the U-tube but not for each geological layer. The main objective of this study was therefore to develop a method

  19. Experimental Study on In-situ Concentration Monitoring of Flue Gas from the Fixed Pollution Source Based on DOAS

    NASA Astrophysics Data System (ADS)

    Tang, Guanghua; Xu, Chuanlong; Wang, Shimin

    2007-06-01

    The air pollution is mainly derived from the flue gas from fixed pollution source and there has been no appropriate method to measure the concentration of flue gas in bad conditions for a long time. Based on the differential optical absorption spectroscopy (DAOS), an improved inversion algorithm, which is applied to the measurement of flue gas concentration at normal temperature and pressure, is put forward according to the characteristics of the flue gas from fixed pollution source and the experimental study of gas concentration measurement is performed combining the continuous transmittance spectrum from ultraviolet to visible region presented by avantes-2048 spectrometer with the absorption cross sections of sulfur dioxide and nitrogen dioxide derived form the experiment. Research results are shown the algorithm can not only be utilized to measure the concentration of sulfur dioxide with the interference of nitrogen dioxide but also be applied to simultaneously measure the concentration of sulfur dioxide and nitrogen dioxide in flue gas containing dust particles of high concentration.

  20. Buffer-Free GeSn and SiGeSn Growth on Si Substrate Using In Situ SnD4 Gas Mixing

    NASA Astrophysics Data System (ADS)

    Mosleh, Aboozar; Alher, Murtadha; Cousar, Larry C.; Du, Wei; Ghetmiri, Seyed Amir; Al-Kabi, Sattar; Dou, Wei; Grant, Perry C.; Sun, Greg; Soref, Richard A.; Li, Baohua; Naseem, Hameed A.; Yu, Shui-Qing

    2016-04-01

    Buffer-free GeSn and SiGeSn films have been deposited on Si via a cold-wall, ultra-high vacuum chemical vapor deposition reactor using in situ gas mixing of deuterated stannane, silane and germane. Material characterization of the films using x-ray diffraction and transmission electron microscopy shows crystalline growth with an array of misfit dislocation formed at the Si substrate interface. Energy dispersive x-ray maps attained from the samples show uniform incorporation of the elements. The Z-contrast map of the high-angle annular dark-field of the film cross section shows uniform incorporation along the growth as well. Optical characterization of the GeSn films through photoluminescence technique shows reduction in the bandgap edge of the materials.

  1. In situ analysis of dynamic laminar flow extraction using surface-enhanced Raman spectroscopy

    PubMed Central

    Wang, Fei; Wang, Hua-Lin; Qiu, Yang; Chang, Yu-Long; Long, Yi-Tao

    2015-01-01

    In this study, we performed micro-scale dynamic laminar flow extraction and site-specific in situ chloride concentration measurements. Surface-enhanced Raman spectroscopy was utilized to investigate the diffusion process of chloride ions from an oil phase to a water phase under laminar flow. In contrast to common logic, we used SERS intensity gradients of Rhodamine 6G to quantitatively calculate the concentration of chloride ions at specific positions on a microfluidic chip. By varying the fluid flow rates, we achieved different extraction times and therefore different chloride concentrations at specific positions along the microchannel. SERS spectra from the water phase were recorded at these different positions, and the spatial distribution of the SERS signals was used to map the degree of nanoparticle aggregation. The concentration of chloride ions in the channel could therefore be obtained. We conclude that this method can be used to explore the extraction behaviour and efficiency of some ions or molecules that enhance the SERS intensity in water or oil by inducing nanoparticle aggregation. PMID:26687436

  2. In situ structural analysis of calcium aluminosilicate glasses under high pressure

    NASA Astrophysics Data System (ADS)

    Muniz, R. F.; de Ligny, D.; Martinet, C.; Sandrini, M.; Medina, A. N.; Rohling, J. H.; Baesso, M. L.; Lima, S. M.; Andrade, L. H. C.; Guyot, Y.

    2016-08-01

    In situ micro-Raman spectroscopy was used to investigate the structural evolution of OH--free calcium aluminosilicate glasses, under high pressure and at room temperature. Evaluation was made of the role of the SiO2 concentration in percalcic join systems, for Al/(Al  +  Si) in the approximate range from 0.9 to 0.2. Under high pressure, the intensity of the main band related to the bending mode of bridging oxygen ({ν\\text{B}} [T-O-T], where T  =  Si or Al) decreased gradually, suggesting that the bonds were severely altered or even destroyed. In Si-rich glasses, compression induced a transformation of Q n species to Q n-1. In the case of Al-rich glass, the Al in the smallest Q n units evolved from tetrahedral to higher-coordinated Al ([5]Al and [6]Al). Permanent structural changes were observed in samples recovered from the highest pressure of around 15 GPa and, particularly for Si-rich samples, the recovered structure showed an increase of three-membered rings in the Si/Al tetrahedral network.

  3. In situ structural analysis of calcium aluminosilicate glasses under high pressure

    NASA Astrophysics Data System (ADS)

    Muniz, R. F.; de Ligny, D.; Martinet, C.; Sandrini, M.; Medina, A. N.; Rohling, J. H.; Baesso, M. L.; Lima, S. M.; Andrade, L. H. C.; Guyot, Y.

    2016-08-01

    In situ micro-Raman spectroscopy was used to investigate the structural evolution of OH‑-free calcium aluminosilicate glasses, under high pressure and at room temperature. Evaluation was made of the role of the SiO2 concentration in percalcic join systems, for Al/(Al  +  Si) in the approximate range from 0.9 to 0.2. Under high pressure, the intensity of the main band related to the bending mode of bridging oxygen ({ν\\text{B}} [T-O-T], where T  =  Si or Al) decreased gradually, suggesting that the bonds were severely altered or even destroyed. In Si-rich glasses, compression induced a transformation of Q n species to Q n‑1. In the case of Al-rich glass, the Al in the smallest Q n units evolved from tetrahedral to higher-coordinated Al ([5]Al and [6]Al). Permanent structural changes were observed in samples recovered from the highest pressure of around 15 GPa and, particularly for Si-rich samples, the recovered structure showed an increase of three-membered rings in the Si/Al tetrahedral network.

  4. In situ observation and analysis of faceted crystal growth process in REBCO superconductive oxide

    NASA Astrophysics Data System (ADS)

    Mori, N.; Nakahara, Y.; Ogi, K.; Mukaida, M.

    2007-10-01

    To clarify the nucleation and growth process of 123 crystals, growth of faceted RE123 (REBa2Cu3O7-X, RE = Nd, Sm, Gd, Y) crystals was observed in situ on MgO(1 0 0) by using high temperature optical microscope with zoom lens. RE123 crystals nucleated and grew at each undercooling (ΔT = 13-50 K). Growth rate (u) and incubation time (tinc) for nucleation were obtained from the relationship between the position of faceted interface and time (t). u increased with increasing ΔTr2 , where ΔTr = ΔT/Tp, Tp was peritectic temperature. Nucleation rate (Iv) was obtained from the relationship between the number of nucleated crystals (n) and time. Iv increased with increasing of exp (- B / ΔTr2), where B was a constant. Both u and Iv under a fixed ΔT increased with increasing Tp: u(Nd123) > u(Sm123) > u(Gd123) and Iv(Nd123) > Iv(Sm123) > Iv(Gd123) for Tp(Nd123) > Tp(Sm123) > Tp(Gd123) in Ar-1%O2 atmosphere.

  5. In situ observation and analysis of crystal growth process of GdBCO superconductive oxide

    NASA Astrophysics Data System (ADS)

    Nakahara, Y.; Inokawa, T.; Mori, N.; Ogi, K.

    2006-10-01

    To clarify the nucleation and growth process of 123 crystals, growth of faceted Gd123(GdBa2Cu3O7-δ) crystals was observed in situ on MgO(1 0 0) by using a high temperature optical microscope with zoom lens (×50-500). Gd123 crystals nucleated and grew at each undercooling (ΔT = 30, 35, 40, 45 K). Growth rate (u) and incubation time (tinc) for nucleation were obtained from the relationship between time and position of faceted interface. u was approximated by a function of ΔT: u =Agp ΔTr2 / η (T) , where Agp is a constant, Agp = 1.0 × 10-5. Nucleation rate (Iv) was obtained from the relationship between time and number of nucleated crystals. Iv was approximated by an exponential function: Iv = {An / η (T) } exp (- B / ΔTr2) , where An and B are constants, An = 1.3 × 107, B = 2.7 × 10-3. The nucleation and growth process of Gd123 crystals were expressed quantitatively by the above equations.

  6. Genome-wide, whole mount in situ analysis of transcriptional regulators in zebrafish embryos.

    PubMed

    Armant, Olivier; März, Martin; Schmidt, Rebecca; Ferg, Marco; Diotel, Nicolas; Ertzer, Raymond; Bryne, Jan Christian; Yang, Lixin; Baader, Isabelle; Reischl, Markus; Legradi, Jessica; Mikut, Ralf; Stemple, Derek; van IJcken, Wilfred; van der Sloot, Antoine; Lenhard, Boris; Strähle, Uwe; Rastegar, Sepand

    2013-08-15

    Transcription is the primary step in the retrieval of genetic information. A substantial proportion of the protein repertoire of each organism consists of transcriptional regulators (TRs). It is believed that the differential expression and combinatorial action of these TRs is essential for vertebrate development and body homeostasis. We mined the zebrafish genome exhaustively for genes encoding TRs and determined their expression in the zebrafish embryo by sequencing to saturation and in situ hybridisation. At the evolutionary conserved phylotypic stage, 75% of the 3302 TR genes encoded in the genome are already expressed. The number of expressed TR genes increases only marginally in subsequent stages and is maintained during adulthood suggesting important roles of the TR genes in body homeostasis. Fewer than half of the TR genes (45%, n=1711 genes) are expressed in a tissue-restricted manner in the embryo. Transcripts of 207 genes were detected in a single tissue in the 24h embryo, potentially acting as regulators of specific processes. Other TR genes were expressed in multiple tissues. However, with the exception of certain territories in the nervous system, we did not find significant synexpression suggesting that most tissue-restricted TRs act in a freely combinatorial fashion. Our data indicate that elaboration of body pattern and function from the phylotypic stage onward relies mostly on redeployment of TRs and post-transcriptional processes. PMID:23684812

  7. Genome-wide, whole mount in situ analysis of transcriptional regulators in zebrafish embryos

    PubMed Central

    Armant, Olivier; März, Martin; Schmidt, Rebecca; Ferg, Marco; Diotel, Nicolas; Ertzer, Raymond; Bryne, Jan Christian; Yang, Lixin; Baader, Isabelle; Reischl, Markus; Legradi, Jessica; Mikut, Ralf; Stemple, Derek; van IJcken, Wilfred; van der Sloot, Antoine; Lenhard, Boris; Strähle, Uwe; Rastegar, Sepand

    2015-01-01

    Transcription is the primary step in the retrieval of genetic information. A substantial proportion of the protein repertoire of each organism consists of transcriptional regulators (TRs). It is believed that the differential expression and combinatorial action of these TRs is essential for vertebrate development and body homeostasis. We mined the zebrafish genome exhaustively for genes encoding TRs and determined their expression in the zebrafish embryo by sequencing to saturation and in situ hybridisation. At the evolutionary conserved phylotypic stage, 75% of the 3302 TR genes encoded in the genome are already expressed. The number of expressed TR genes increases only marginally in subsequent stages and is maintained during adulthood suggesting important roles of the TR genes in body homeostasis. Fewer than half of the TR genes (45%, n=1711 genes) are expressed in a tissue-restricted manner in the embryo. Transcripts of 207 genes were detected in a single tissue in the 24 h embryo, potentially acting as regulators of specific processes. Other TR genes were expressed in multiple tissues. However, with the exception of certain territories in the nervous system, we did not find significant synexpression suggesting that most tissue-restricted TRs act in a freely combinatorial fashion. Our data indicate that elaboration of body pattern and function from the phylotypic stage onward relies mostly on redeployment of TRs and post-transcriptional processes. PMID:23684812

  8. In situ analysis of intrahepatic virological events in chronic hepatitis B virus infection

    PubMed Central

    Zhang, Xiaonan; Lu, Wei; Zheng, Ye; Wang, Weixia; Bai, Lu; Chen, Liang; Feng, Yanling; Zhang, Zhanqing

    2016-01-01

    Persistent hepatitis B virus (HBV) infection is established by the formation of an intranuclear pool of covalently closed circular DNA (cccDNA) in the liver. Very little is known about the intrahepatic distribution of HBV cccDNA in infected patients, particularly at the single-cell level. Here, we established a highly sensitive and specific ISH assay for the detection of HBV RNA, DNA, and cccDNA. The specificity of our cccDNA probe set was confirmed by its strict intranuclear signal and by a series of Southern blot analyses. Use of our in situ assay in conjunction with IHC or immunofluorescence uncovered a surprisingly mosaic distribution of viral antigens and nucleic acids. Most strikingly, a mutually exclusive pattern was found between HBV surface antigen–positive (HBsA-positive) and HBV DNA– and cccDNA-positive cells. A longitudinal observation of patients over a 1-year period of adeforvir therapy confirmed the persistence of a nuclear reservoir of viral DNA, although cytoplasmic DNA was effectively depleted in these individuals. In conclusion, our method for detecting viral nucleic acids, including cccDNA, with single-cell resolution provides a means for monitoring intrahepatic virological events in chronic HBV infection. More important, our observations unravel the complexity of the HBV life cycle in vivo. PMID:26901811

  9. Random amplified polymorphic DNA analysis, genome size, and genomic in situ hybridization of triploid viviparous onions

    PubMed

    Puizina; Javornik; Bohanec; Schweizer; Maluszynska; Papes

    1999-12-01

    Triploid viviparous onions (Allium cepa L. var. viviparum Metzg. (ALEF.), auct.), (2n = 3x = 24), are known in some countries only as a rare relic crop, while in other parts of the world they are still traditionally or even commercially cultivated. Results indicating an identical random amplified polymorphic DNA (RAPD) banding pattern and the same DNA content (2C = 43.4 pg) establish the high genetic similarity and the unique origin of the Croatian clone Ljutika and the Indian clone Pran. In order to determine the parental Allium species of these natural triploid hybrids, genomic fluorescent in situ hybridization (GISH) was applied. Biotinylated genomic DNAs from six diploid Allium species (A. cepa L., A. fistulosum L., A. roylei Stearn, A. vavilovii M. Pop. et Vved., A. galanthum Kar. et Kir., A. oschaninii O. Fedtsch.) were used as probes in this study. While probes obtained from genomic DNA of A. cepa, A. vavilovii, and A. roylei hybridized to somatic chromosomes of Ljutika probes from A. fistulosum, A. galanthum, and A. oschaninii did not. The DNA probes of A. cepa and A. roylei each completely or predominantly labelled one genome (eight chromosomes). A few chromosomes, the markers of the triploid karyotype, were not completely labelled by any probe applied. Our GISH results indicate that triploid viviparous onions might possess a complex triparental genome organization. PMID:10659789

  10. Analysis of In-Situ of Ozone Measurements in Saharan Mineral Dust during AEROSE Cruises

    NASA Astrophysics Data System (ADS)

    Roper, E. D.; Morris, V. R.; Nalli, N. R.; Joseph, E.

    2012-12-01

    The trans-Atlantic Aerosol and Oceanographic Science Expeditions (AEROSE) are a series of experiments that began in 2004 and take place in the tropical Atlantic Ocean. AEROSE collects a unique set of critical measurements to characterize the microphysical and chemical evolution of the Saharan dust aerosols during long-range transport. Continuous in-situ surface level measurements over the tropical Atlantic allows for accurate determination of lower tropospheric ozone concentrations, and its effects on the regional environment and climate that may be used to validate satellite observations. Ozone is instrumental in regulating the atmosphere's oxidizing capacity and can influence background levels of trace chemical species which affect the composition of the atmosphere and create climatic variations. Several studies have shown that ozone concentrations diminish with increased loading of dust particles from the Sahara. Current theories indicate that decomposition of ozone may be due to NOx titrations, decreased radiation, photocatalysis, interactions with organics, or heterogeneous reactions. In effort to understand the response of marine boundary layer ozone with coarse aerosols, analyses of ozone concentrations and aerosol correlations found in dusty Saharan air masses from various cruises will be presented.

  11. Analysis of changes in crystalline lens thickness and its refractive power after laser in situ keratomileusis

    PubMed Central

    Wang, Liang; Guo, Hai-Ke; Zeng, Jing; Jin, Hai-Ying

    2012-01-01

    AIM To evaluate changes in the anterior chamber depth (ACD), crystalline lens thickness (LT) and its refractive power after laser in situ keratomileusis (LASIK). METHODS In all cases, the preoperative and postoperative central ACD which were measured with Pentacam, Orbscan, IOL-Master and A-scan ultrasonography, central corneal true net power which was measured with the Pentacam, Orbscan and IOL-Master, axial length (AL) which was measured with IOL-Master and LT which was measured with the A-scan ultrasonography were compared using the paired sample t test. Ocular refractive errors and lens refractive power at corneal plane were calculated and their correlations were also evaluated before and after LASIK. RESULTS At 1 week after LASIK, LT and crystalline lens refractive power at corneal plane (Dlens) which were associated with the IOL-Master and Pentacam increased significantly (P≤0.005), ACD decreased significantly (P≤0.001), but no significant increase was observed in the Dlens which was associated with the Orbscan (P=0.261). Significant correlations between the changes in the ocular refractive errors and Dlens which were associated with the Pentacam were observed at 1 week and 6 months after LASIK (P=0.028; P=0.001). CONCLUSION LT increased significantly after LASIK, and this might partially lead to ACD decrease, Dlens increase and a small quantity of myopic regression. PMID:22553764

  12. Corneal scarring from laser in situ keratomileusis after epikeratoplasty: clinical and histopathologic analysis.

    PubMed

    Khandelwal, Sumitra S; Randleman, J Bradley; Grossniklaus, Hans E

    2013-03-01

    A 47-year-old woman required penetrating keratoplasty in the right eye after developing delayed visually significant corneal scarring bilaterally after laser in situ keratomileusis (LASIK) in 1997 following epikeratoplasty in 1987. Spectral domain ocular coherence tomography of the left cornea showed a 100 μm lenticule with a LASIK flap posterior to the host Bowman layer at 250 μm. Histopathology and electron microscopy of the right corneal button showed a 120 μm lenticule with a LASIK flap within the lenticule at 100 μm. Clinically significant scarring was present within the LASIK flap interface, within the lenticule stroma, and within the area of the underlying host Bowman layer. There were keratocytes at the junction between the LASIK flap and lenticule stromal bed. Although epikeratoplasty is no longer practiced, post-epikeratoplasty patients may present for refractive surgical options and LASIK carries significant risks for corneal scarring in these individuals, especially when using flap-creating devices that may create thin LASIK flaps.

  13. Isolation of a hyperthermophilic archaeum predicted by in situ RNA analysis.

    PubMed

    Huber, R; Burggraf, S; Mayer, T; Barns, S M; Rossnagel, P; Stetter, K O

    1995-07-01

    A variety of hyperthermophilic bacteria and archaea have been isolated from high-temperature environments by plating and serial dilutions. However, these techniques allow only the small percentage of organisms able to form colonies, or those that are predominant within environmental samples, to be obtained in pure culture. Recently, in situ 16S ribosomal RNA analyses of samples from the Obsidian hot pool at Yellowstone National Park, Wyoming, revealed a variety of archaeal sequences, which were all different from those of previously isolated species. This suggests substantial diversity of archaea with so far unknown morphological, physiological and biochemical features, which may play an important part within high-temperature ecosystems. Here we describe a procedure to obtain pure cultures of unknown organisms harbouring specific 16S rRNA sequences identified previously within the environment. It combines visual recognition of single cells by phylogenetic staining and cloning by 'optical tweezers'. Our result validates polymerase chain reaction data on the existence of large archael communities. PMID:7541115

  14. Analysis of human invasive cytotrophoblasts using multicolor fluorescence in situ hybridization.

    PubMed

    Weier, Jingly F; Hartshorne, Christy; Nguyen, Ha Nam; Baumgartner, Adolf; Polyzos, Aris A; Lemke, Kalistyn H; Zeng, Hui; Weier, Heinz-Ulrich G

    2013-12-01

    Multicolor fluorescence in situ hybridization, or FISH, is a widely used method to assess fixed tissues or isolated cells for numerical and structural chromosome aberrations. Unlike other screening procedures which provide average chromosome numbers for heterogeneous samples, FISH is a sensitive cell-by-cell method to analyze the distribution of abnormal cells in complex tissues. Here, we applied FISH to characterize chromosomal composition of a rare, but very important class of human cells that stabilize the fetal-maternal interface connecting the placenta to the uterine wall during early pregnancy, called invasive cytotrophoblasts (iCTBs). Combining differently-labeled, chromosome-specific DNA probes, we were able to unambiguously determine the number of up to six different autosomes and gonosomes in individual cell nuclei from iCTBs selected on the basis of their invasive behavior. In this manuscript, we describe a method for generation of iCTBs from placental villi, and provide the complete workflow of our FISH experiments including a detailed description of reagents and a trouble-shooting guide. We also include an in-depth discussion of the various types and sources of DNA probes which have evolved considerably in the last two decades. Thus, this communication represents both a complete guide as well as a valuable resource, intended to allow an average laboratory to reproduce the experiments and minimize the amount of specialized, and often costly, equipment.

  15. X chromosome aneuploidy in infertile women: Analysis by interphase fluorescent in situ hybridization

    SciTech Connect

    Morris, M.A.; Moix, I.; Mermillod, B.

    1994-09-01

    Up to 1 in 3 couples have a problem of infertility at some time in their lives. Sex chromosome anomalies are found in 5-10% of couples, with mosaic aneuploidy being a common finding in primary infertility. Recurrent spontaneous abortion (RSA), in contrast, is frequently associated with autosomal structural anomalies. We hypothesized that low-level mosaic X chromosome aneuploidy was associated with primary infertility but not with RSA. Three groups were studied: women from couples with primary infertillity (n=26); women with three or more spontaneous abortions (n=22); and age-matched normally fertile women (at least two pregnancies; n=28). Interphase fluorescent in situ hybridization (FISH) was used to determine X chromosome ploidy in 100 nuclei per patient, using a contig of three cosmids from MAO locus (kindly donated by W. Berger, Nijmegen). A control probe (chr. 15 centromere) was simultaneously hybridized, and only nuclei containing two control signals were scored for the X chromosome. The mean numbers of nuclei with two X chromosome signals were the same in all groups (Welch equality of means test: p>0.97). However, there is a significant difference between the variances of the primary infertile and RSA groups (Levene`s test: p=0.025 after Bonferrone correction for multiple testing). This provides preliminary support for the hypothesis of an association between primary infertility and low-level mosaic X chromosome aneuploidy.

  16. Detection and analysis of DNA damage in mouse skeletal muscle in situ using the TUNEL method.

    PubMed

    Fayzullina, Saniya; Martin, Lee J

    2014-01-01

    Terminal deoxynucleotidyl transferase (TdT) deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL) is the method of using the TdT enzyme to covalently attach a tagged form of dUTP to 3' ends of double- and single-stranded DNA breaks in cells. It is a reliable and useful method to detect DNA damage and cell death in situ. This video describes dissection, tissue processing, sectioning, and fluorescence-based TUNEL labeling of mouse skeletal muscle. It also describes a method of semi-automated TUNEL signal quantitation. Inherent normal tissue features and tissue processing conditions affect the ability of the TdT enzyme to efficiently label DNA. Tissue processing may also add undesirable autofluorescence that will interfere with TUNEL signal detection. Therefore, it is important to empirically determine tissue processing and TUNEL labeling methods that will yield the optimal signal-to-noise ratio for subsequent quantitation. The fluorescence-based assay described here provides a way to exclude autofluorescent signal by digital channel subtraction. The TUNEL assay, used with appropriate tissue processing techniques and controls, is a relatively fast, reproducible, quantitative method for detecting apoptosis in tissue. It can be used to confirm DNA damage and apoptosis as pathological mechanisms, to identify affected cell types, and to assess the efficacy of therapeutic treatments in vivo. PMID:25549099

  17. Expression of T cell receptors by thymocytes: in situ staining and biochemical analysis.

    PubMed Central

    Cristanti, A; Colantoni, A; Snodgrass, R; von Boehmer, H

    1986-01-01

    We have examined the in situ expression of T cell receptor (TCR) V beta 8 protein in murine thymus during ontogeny using the monoclonal antibody F23.1. Positive cells were first detected at day 15 of gestation (0.6%). By day 16 the frequency of positive cells increased dramatically (4.18%). From day 16 to day 17 positive cells doubled (8.17%). The first clusters of F23.1 positive cells were seen at day 17. In the cortex, positive cells decreased from 14% in the newborn mice to 9.8% in 8-week-old mice, whereas in the medulla the frequency remained unchanged at 20%. The antibody F23.1, as well as an antiserum raised against the constant region of the beta chain, immunoprecipitated receptor dimers from highly purified Lyt2+, L3T4+ thymocytes and from two thymic lymphomas of cortical phenotype which express full size alpha and beta mRNA. The receptor dimer could not be precipitated from Lyt2-, L3T4- thymocytes. The results are discussed with regard to intrathymic T cell repertoire selection. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. PMID:2431899

  18. In situ analysis of dynamic laminar flow extraction using surface-enhanced Raman spectroscopy.

    PubMed

    Wang, Fei; Wang, Hua-Lin; Qiu, Yang; Chang, Yu-Long; Long, Yi-Tao

    2015-01-01

    In this study, we performed micro-scale dynamic laminar flow extraction and site-specific in situ chloride concentration measurements. Surface-enhanced Raman spectroscopy was utilized to investigate the diffusion process of chloride ions from an oil phase to a water phase under laminar flow. In contrast to common logic, we used SERS intensity gradients of Rhodamine 6G to quantitatively calculate the concentration of chloride ions at specific positions on a microfluidic chip. By varying the fluid flow rates, we achieved different extraction times and therefore different chloride concentrations at specific positions along the microchannel. SERS spectra from the water phase were recorded at these different positions, and the spatial distribution of the SERS signals was used to map the degree of nanoparticle aggregation. The concentration of chloride ions in the channel could therefore be obtained. We conclude that this method can be used to explore the extraction behaviour and efficiency of some ions or molecules that enhance the SERS intensity in water or oil by inducing nanoparticle aggregation. PMID:26687436

  19. Process Analysis Of Thin Film Deposition With An In Situ Ellipsometer

    NASA Astrophysics Data System (ADS)

    Savrda, Steven; Himel, Marc D.; Guenther, Karl H.; Urban, Frank K.

    1990-01-01

    Thin films deposited in high vacuum by thermal evaporation, electron beam evaporation, and ion assisted deposition are anything but smooth, homogeneous, stratified media with plane parallel boundaries as assumed in thin film design and theory. In particular, the porosity brought about by the columnar microstructure of these films has been a problem ever since their first use. The refractive index may change upon exposure to ambient atmosphere, as a result of H2O adsorption. In-situ rapid scanning spectrophotometers and ellipsometers have helped various researchers to determine the degree of index change and the packing density of the films. Low voltage reactive ion plating is a rather novel deposition technique which produces thin films with packing densities of unity and higher. The dense, vitreous or polycrystalline microstructure, which pre-vents the films from adsorbing water upon exposure to air, yields films with bulk-like optical properties that are constant in time. However, there are problems with increased absorption particularly with ion plated TiO2 and SiO2 multilayer thin-film stacks. Continuous measurements of n and k during deposition need to be studied in order to determine the location of the increased absorption. Engineering aspects of mounting a Rudolph Research ellipsometer on a Balzers BAP 800 vacuum system will also be discussed.

  20. Determining in situ periphyton community responses to nutrient and atrazine gradients via pigment analysis.

    PubMed

    Dalton, Rebecca L; Boutin, Céline; Pick, Frances R

    2015-05-15

    Agrochemicals, including fertilizers and herbicides, are significant contributors of non-point source pollution to surface waters and have the potential to negatively affect periphyton. We characterized periphyton communities using pigment markers to assess the effects of nutrient enrichment and the herbicide atrazine with in situ experimental manipulations and by examining changes in community structure along existing agrochemical gradients. In 2008, the addition of nutrients (20 mg/L nitrate and 1.25 mg/L reactive phosphate), atrazine (20 μg/L) and a combination of both nutrients and atrazine had no significant effect on periphyton biomass or community structure in a stream periphytometer experiment. In 2009, similar experiments with higher concentrations of atrazine (200 μg/L) at two stream sites led to some minor effects. In contrast, at the watershed scale (2010) periphyton biomass (mg/m(2) chlorophyll a) increased significantly along correlated gradients of nitrate and atrazine but no direct effects of reactive phosphate were observed. Across the watershed, the average periphyton community was composed of Bacillariophyceae (60.9%), Chlorophyceae (28.1%), Cryptophyceae (6.9%) and Euglenophyceae (4.1%), with the Bacillariophyceae associated with high turbidity and the Chlorophyceae with nitrate enrichment. Overall, effects of nitrate on periphyton biomass and community structure superseded effects of reactive phosphate and atrazine. PMID:25700361

  1. Establishment of the genomic in situ hybridization (GISH) technique for analysis in interspecific hybrids of Passiflora.

    PubMed

    Melo, C A F; Silva, G S; Souza, M M

    2015-01-01

    The genomic in situ hybridization (GISH) technique was applied to Passiflora interspecific F1 HD13-133 hybrids (Passiflora sublanceolata x Passiflora foetida) and HD15-101 (Passiflora gardineri x Passiflora gibertii), and the backcrossed hybrids (BC1) HD18-106 and HD18-113 (Passiflora sublanceolata x HD13-133). GISH was performed using genomic probes prepared with the DNA from the paternal genitor, whereas the maternal DNA was used as blocking DNA and employed at various concentrations (20X, 40X, 60X, and 100X) in relation to the probe concentration. At the same time, GISH was applied with the use of simultaneous probes from both genomes, paternal and maternal, that were detected with avidin-FITC and anti-digoxigenin-rhodamine, respectively. Both methodologies allowed the distinguishing of the maternal and paternal genomes, thus confirming the hybrid nature of all the analyzed genotypes. Furthermore, the presence of recombinant chromosomes in BC1 hybrids revealed the occurrence of meiotic recombination in HD13 hybrids. This application of the GISH technique is an important step towards genomic analyses of Passiflora hybrids: it can broaden the phylogenetic and evolutionary studies of the genus and, at the same time, contribute to breeding programs. PMID:25867365

  2. Isolation of a hyperthermophilic archaeum predicted by in situ RNA analysis.

    PubMed

    Huber, R; Burggraf, S; Mayer, T; Barns, S M; Rossnagel, P; Stetter, K O

    1995-07-01

    A variety of hyperthermophilic bacteria and archaea have been isolated from high-temperature environments by plating and serial dilutions. However, these techniques allow only the small percentage of organisms able to form colonies, or those that are predominant within environmental samples, to be obtained in pure culture. Recently, in situ 16S ribosomal RNA analyses of samples from the Obsidian hot pool at Yellowstone National Park, Wyoming, revealed a variety of archaeal sequences, which were all different from those of previously isolated species. This suggests substantial diversity of archaea with so far unknown morphological, physiological and biochemical features, which may play an important part within high-temperature ecosystems. Here we describe a procedure to obtain pure cultures of unknown organisms harbouring specific 16S rRNA sequences identified previously within the environment. It combines visual recognition of single cells by phylogenetic staining and cloning by 'optical tweezers'. Our result validates polymerase chain reaction data on the existence of large archael communities.

  3. Determining in situ periphyton community responses to nutrient and atrazine gradients via pigment analysis.

    PubMed

    Dalton, Rebecca L; Boutin, Céline; Pick, Frances R

    2015-05-15

    Agrochemicals, including fertilizers and herbicides, are significant contributors of non-point source pollution to surface waters and have the potential to negatively affect periphyton. We characterized periphyton communities using pigment markers to assess the effects of nutrient enrichment and the herbicide atrazine with in situ experimental manipulations and by examining changes in community structure along existing agrochemical gradients. In 2008, the addition of nutrients (20 mg/L nitrate and 1.25 mg/L reactive phosphate), atrazine (20 μg/L) and a combination of both nutrients and atrazine had no significant effect on periphyton biomass or community structure in a stream periphytometer experiment. In 2009, similar experiments with higher concentrations of atrazine (200 μg/L) at two stream sites led to some minor effects. In contrast, at the watershed scale (2010) periphyton biomass (mg/m(2) chlorophyll a) increased significantly along correlated gradients of nitrate and atrazine but no direct effects of reactive phosphate were observed. Across the watershed, the average periphyton community was composed of Bacillariophyceae (60.9%), Chlorophyceae (28.1%), Cryptophyceae (6.9%) and Euglenophyceae (4.1%), with the Bacillariophyceae associated with high turbidity and the Chlorophyceae with nitrate enrichment. Overall, effects of nitrate on periphyton biomass and community structure superseded effects of reactive phosphate and atrazine.

  4. In situ analysis of intrahepatic virological events in chronic hepatitis B virus infection.

    PubMed

    Zhang, Xiaonan; Lu, Wei; Zheng, Ye; Wang, Weixia; Bai, Lu; Chen, Liang; Feng, Yanling; Zhang, Zhanqing; Yuan, Zhenghong

    2016-03-01

    Persistent hepatitis B virus (HBV) infection is established by the formation of an intranuclear pool of covalently closed circular DNA (cccDNA) in the liver. Very little is known about the intrahepatic distribution of HBV cccDNA in infected patients, particularly at the single-cell level. Here, we established a highly sensitive and specific ISH assay for the detection of HBV RNA, DNA, and cccDNA. The specificity of our cccDNA probe set was confirmed by its strict intranuclear signal and by a series of Southern blot analyses. Use of our in situ assay in conjunction with IHC or immunofluorescence uncovered a surprisingly mosaic distribution of viral antigens and nucleic acids. Most strikingly, a mutually exclusive pattern was found between HBV surface antigen-positive (HBsA-positive) and HBV DNA- and cccDNA-positive cells. A longitudinal observation of patients over a 1-year period of adeforvir therapy confirmed the persistence of a nuclear reservoir of viral DNA, although cytoplasmic DNA was effectively depleted in these individuals. In conclusion, our method for detecting viral nucleic acids, including cccDNA, with single-cell resolution provides a means for monitoring intrahepatic virological events in chronic HBV infection. More important, our observations unravel the complexity of the HBV life cycle in vivo. PMID:26901811

  5. Analysis of chromosome segregation during mammalian meiosis using combined immunofluorescence and fluorescence in situ hubridization

    SciTech Connect

    Hunt, P.A.; Embury, P.B.; Mroz, K.M.

    1994-09-01

    Meiotic non-disjunction is thought to occur in 10-20% of all human oocytes, making this the most common genetic abnormality in our species. Aberrant recombination has been implicated in the genesis of these errors; however, direct studies of the meiotic process have been hampered by the lack of material and appropriate technology. We have developed a technique for the evaluation of meiosis in intact mammalian oocytes that combines immunofluorescence and fluorescence in situ hybridization (FISH). This allows for simultaneous, 3-dimensional visualization of the meiotic spindle, the alignment of the chromosomes on the spindle, and the placement of specific chromosomes. We have used this technology to follow meiotic progression in oocytes from XO female mice to evaluate the behavior of an unsynapsed chromosome during mammalian meiosis. Perturbations in chromosome behavior are evident early in meiosis: during the formation of the first meiotic spindle, the univalent X chromosome is properly positioned. With the onset of anaphase, the single X chromosome most commonly segregates as an intact chromosome, although equational segregation of the X chromatids is seen in a significant minority (approximately 20%) of oocytes. These observations demonstrate that failure of pairing/recombination can result in segregation of sister chromatids at meiosis I. This has obvious implications for human non-disjunction, much of which is thought to be due to recombination deficiencies; accordingly, we are now extending our studies to include analyses of human oocytes.

  6. In-Situ observations of speciated organics in gas and particle phases: CalNex2010 Bakersfield and Los Angeles (Invited)

    NASA Astrophysics Data System (ADS)

    Goldstein, A. H.; Gentner, D. R.; Isaacman, G. A.; Worton, D. R.; Zhao, Y.; Weber, R.; Kreisberg, N. M.; Hering, S. V.; Williams, B. J.; Hohaus, T.; Jayne, J.; Lambe, A.; Williams, L. R.; Jimenez, J. L.; CalNex Bakersfield Science Team

    2010-12-01

    To identify the major sources and formation mechanisms of organic aerosol in polluted urban regions, we measured a wide range of gas phase and particle phase organics during the Research at the Nexus of Air Quality and Climate Change (CalNex) 2010 experiment at the Bakersfield and Pasadena supersites. The CalNex supersites included an extensive array of co-located observations with cutting edge measurement technologies. This talk will highlight the observations of speciated organics and how they can be used to 1) identify the main emission sources linked with primary and secondary organic aerosol (SOA), 2) identify individual and classes of volatile and semivolatile organic compounds (VOCs and SVOCs) indicative of specific source categories and transformation processes, and 3) examine the gas/particle partitioning of specific SVOCs and the parameters which influence their uptake into SOA, such as meteorological (T, RH, etc), or chemical composition (aerosol organic carbon mass, aerosol acidity, etc.). The complex chemical composition of atmospheric aerosols, particularly the organic carbon portion, presents unique measurement challenges. We developed the Thermal Desorption Aerosol Gas chromatograph (TAG) system for hourly in-situ speciation of a wide range of primary and secondary species including alkanes, aldehydes, ketones, PAHs, monocarboxylic acids, and many more. Recently, we incorporated two-dimensional chromatography (GC×GC) into TAG (2DTAG) enhancing our chromatographic separation power by including polarity separation following volatility separation. We have also developed a combined TAG-AMS (Aerosol Mass Spectrometer) instrument for simultaneous measurements of the total and speciated aerosol composition. Observations reported from Bakersfield include ambient concentrations of ~250 species of VOCs measured hourly via in-situ gas chromatography containing 1-17 C atoms and a variety of functional groups (e.g. aldehydes, ketones, alcohols, halogens, sulfur

  7. Chelating-Template-Assisted in Situ Encapsulation of Zinc Ferrite Inside Silica Mesopores for Enhanced Gas-Sensing Characteristics.

    PubMed

    Niu, Kui; Liang, Liman; Peng, Fei; Zhang, Fan; Gu, Yao; Tian, Hongyan

    2016-09-21

    A facile in situ approach has been designed to synthesize zinc ferrite/mesoporous silica guest-host composites. Chelating surfactant, N-hexadecyl ethylenediamine triacetic acid, was employed as structure-directing agent to fabricate mesoporous silica skeleton and simultaneously as complexing agent to incorporate stoichiometric amounts of zinc and iron ions into silica cavities. On this basis, spinel zinc ferrite nanoparticles with grain sizes less than 3 nm were encapsulated in mesoporous channels after calcination. The silica mesostructure, meanwhile, displayed a successive transformation from hexagonal p6mm through bicontinuous cubic Ia3̅d to lamellar phase with increasing the dopant concentration in the initial template solution. In comparison with zinc ferrite nanopowder prepared without silica host, the composite with bicontinuous architecture exhibited higher sensitivity, lower detection limit, lower optimum working temperature, quicker response, and shorter recovery time in sensing performance toward hydrogen sulfide. The significant improvements are from the high surface-to-volume ratio of the guest oxides and the three-dimensional porous structure of the composite. We believe the encapsulation route presented here may pave the way for directly introducing complex metal oxide into mesoporous silica matrix with tailorable mesophases for applications in sensing or other fields. PMID:27579863

  8. Novel MEMS-based gas-cell/heating specimen holder provides advanced imaging capabilities for in situ reaction studies.

    PubMed

    Allard, Lawrence F; Overbury, Steven H; Bigelow, Wilbur C; Katz, Michael B; Nackashi, David P; Damiano, John

    2012-08-01

    In prior research, specimen holders that employ a novel MEMS-based heating technology (Aduro™) provided by Protochips Inc. (Raleigh, NC, USA) have been shown to permit sub-Ångström imaging at elevated temperatures up to 1,000°C during in situ heating experiments in modern aberration-corrected electron microscopes. The Aduro heating devices permit precise control of temperature and have the unique feature of providing both heating and cooling rates of 10⁶°C/s. In the present work, we describe the recent development of a new specimen holder that incorporates the Aduro heating device into a "closed-cell" configuration, designed to function within the narrow (2 mm) objective lens pole piece gap of an aberration-corrected JEOL 2200FS STEM/TEM, and capable of exposing specimens to gases at pressures up to 1 atm. We show the early results of tests of this specimen holder demonstrating imaging at elevated temperatures and at pressures up to a full atmosphere, while retaining the atomic resolution performance of the microscope in high-angle annular dark-field and bright-field imaging modes.

  9. Chelating-Template-Assisted in Situ Encapsulation of Zinc Ferrite Inside Silica Mesopores for Enhanced Gas-Sensing Characteristics.

    PubMed

    Niu, Kui; Liang, Liman; Peng, Fei; Zhang, Fan; Gu, Yao; Tian, Hongyan

    2016-09-21

    A facile in situ approach has been designed to synthesize zinc ferrite/mesoporous silica guest-host composites. Chelating surfactant, N-hexadecyl ethylenediamine triacetic acid, was employed as structure-directing agent to fabricate mesoporous silica skeleton and simultaneously as complexing agent to incorporate stoichiometric amounts of zinc and iron ions into silica cavities. On this basis, spinel zinc ferrite nanoparticles with grain sizes less than 3 nm were encapsulated in mesoporous channels after calcination. The silica mesostructure, meanwhile, displayed a successive transformation from hexagonal p6mm through bicontinuous cubic Ia3̅d to lamellar phase with increasing the dopant concentration in the initial template solution. In comparison with zinc ferrite nanopowder prepared without silica host, the composite with bicontinuous architecture exhibited higher sensitivity, lower detection limit, lower optimum working temperature, quicker response, and shorter recovery time in sensing performance toward hydrogen sulfide. The significant improvements are from the high surface-to-volume ratio of the guest oxides and the three-dimensional porous structure of the composite. We believe the encapsulation route presented here may pave the way for directly introducing complex metal oxide into mesoporous silica matrix with tailorable mesophases for applications in sensing or other fields.

  10. Evaluation of new concepts for in situ vitrification: Power system, melt insulation, and off-gas containment

    SciTech Connect

    Luey, J.; Powell, T.D.; Heath, W.O.; Richardson, R.L.

    1992-07-01

    In situ vitrification (ISV) is a thermal process that converts contaminated soil into a highly leach-resistant material resembling natural obsidian. The ISV process was developed by the Pacific Northwest Laboratory (PNL)(a) for the US Department of Energy (DOE) to treat soils contaminated with transuranics. Since 1980, ISV has grown from a concept to an innovative technology through bench-, engineering-, intermediate-, and full-scale tests. Efforts by PNL have developed ISV into a technology considered available for limited deployment to remediate contaminated soil. The technology has been transferred to a licensee for commercial application. In September 1991, PNL conducted an operational acceptance test (OAT) of the modified engineering-scale unit. The OAT provided an opportunity to conduct proof-of-principle testing of new concepts for ISV technology. This additional testing was permitted since it was determined that testing of these new concepts would have no impact on the OAT objective. In discussing the proof-of-principle portion of the engineering-scale test, this report presents conclusions from this work and also describes the conceptual bases of the tested concepts, the engineering-scale test equipment and setup, and test results.

  11. DOTS: A High Resolution Orbitrap Mass Spectrometer for In Situ Analysis of the surface samples of Airless Planetary Bodies

    NASA Astrophysics Data System (ADS)

    Briois, Christelle; Thissen, Roland; Engrand, Cécile; Altwegg, Kathrin; Bouabdellah, Abdel; Boukrara, Amirouche; Carrasco, Nathalie; Chapuis, Claude; Cottin, Hervé; Grün, Eberhard; Grand, Noel; Henkel, Hartmut; Kempf, Sascha; Lebreton, Jean-Pierre; Makarov, Alexander A.; Postber, Frank; Srama, Ralf; Schmidt, Jürgen; Szopa, Cyril; Thirkell, Laurent; Tobie, Gabriel; Wurz, Peter; Zolotov, Mikhail Yu

    2013-04-01

    The dust detectors on board the Ulysses and Galileo spacecraft have shown that the Galilean satellites are surrounded by clouds of sub-micrometer size grains generated by impacts of interplanetary (micro-) meteoroids [1, 2]. In situ chemical analysis from orbit of these ballistic grains ejected from the surface of airless bodies provides a unique opportunity to remotely access the chemical composition of the Jovian moons' surface and subsurface. For Saturn, in situ identification by the Cassini Dust Analyzer (CDA) of sodium in icy grains in the E-Ring and in Enceladus plumes have proven a subsurface liquid water reservoir inside Enceladus [3, 4]. Noticeably, this was not accessible to other in situ or traditional remote sensing techniques. In situ measurements, either during a flyby or from orbit, of grains ejected from the surface, or emerging from the subsurface, of an airless body is a powerful tool to remotely study its surface composition and the nature of its geological activity. Crucial constraints on habitability can thus be determined. Our consortium of laboratories, in collaboration with Thermo Fischer Scientific [5, 6], is currently developing a high mass resolution Fourier Transform (FT) Orbitrap-based mass spectrometer optimized for in situ analysis of dust and icy grains in the environment of Solar System airless bodies. This new generation of dust mass spectrometer was studied in the framework of the Europa Jupiter System Mission (EJSM) instrument study in 2010-2012 and proposed in response to ESA's AO for the JUpiter ICy moons Explorer (JUICE) mission [7]. This mass analyser can provide very high mass resolution analysis (M/ΔM reaching 50 000 at m/z 50 Da). DOTS would allow identification of elemental and molecular species with excellent accuracy, in the 20-1000 Da mass range. In the context of the JUICE mission, DOTS would provide decisive information on the surface composition and on the putative liquid oceans in the subsurface of Ganymede

  12. In situ hyperspectral data analysis for coverage estimation of submerged plant Vallisneria spiralis in Hangzhou Bay wetland

    NASA Astrophysics Data System (ADS)

    Cheng, Qian; Wu, Xiuju

    2010-10-01

    In Situ hyperspectral data analysis for varied coverage estimation of submerged plant is very important for the interpretation of remote sensing images. In this study, the hyperspectral reflectance of Vallisneria spiralis was measured using a Spectroradiometer with spectral range of 350-1050 nm and resolution of 3 nm in Hangzhou bay wetland and the cover of submerged plant was measured. The results showed that the reflectance rate and the "red edge peak" of the first derivation of Vallisneria spiralis spectrum rose with its increasing coverage. The relationships between the coverage of Vallisneria spiralis and the spectral reflectance, spectral indices and red edge at the wavelengths were carried out and analyzed respectively. These results showed a clear linear relationship between the coverage of Vallisneria spiralis and spectrum, and the coverage of Vallisneria spiralis could be quantitatively estimated from the reflectance measured in situ. The hyperspectral remote sensing have a ability and potential to distinguish and monitor the distribution and dynamics of submerged vegetation on a large scale.

  13. Proteome-wide analysis reveals an age-associated cellular phenotype of in situ aged human fibroblasts

    PubMed Central

    Waldera-Lupa, Daniel M.; Kalfalah, Faiza; Florea, Ana-Maria; Sass, Steffen; Kruse, Fabian; Rieder, Vera; Tigges, Julia; Fritsche, Ellen; Krutmann, Jean; Busch, Hauke; Boerries, Melanie; Meyer, Helmut E.; Boege, Fritz; Theis, Fabian

    2014-01-01

    We analyzed an ex vivo model of in situ aged human dermal fibroblasts, obtained from 15 adult healthy donors from three different age groups using an unbiased quantitative proteome-wide approach applying label-free mass spectrometry. Thereby, we identified 2409 proteins, including 43 proteins with an age-associated abundance change. Most of the differentially abundant proteins have not been described in the context of fibroblasts’ aging before, but the deduced biological processes confirmed known hallmarks of aging and led to a consistent picture of eight biological categories involved in fibroblast aging, namely proteostasis, cell cycle and proliferation, development and differentiation, cell death, cell organization and cytoskeleton, response to stress, cell communication and signal transduction, as well as RNA metabolism and translation. The exhaustive analysis of protein and mRNA data revealed that 77% of the age-associated proteins were not linked to expression changes of the corresponding transcripts. This is in line with an associated miRNA study and led us to the conclusion that most of the age-associated alterations detected at the proteome level are likely caused post-transcriptionally rather than by differential gene expression. In summary, our findings led to the characterization of novel proteins potentially associated with fibroblast aging and revealed that primary cultures of in situ aged fibroblasts are characterized by moderate age-related proteomic changes comprising the multifactorial process of aging. PMID:25411231

  14. Estimating the greenhouse gas fluxes of European grasslands with a process-based model: 1. Model evaluation from in situ measurements

    NASA Astrophysics Data System (ADS)

    Vuichard, Nicolas; Soussana, Jean-FrançOis; Ciais, Philippe; Viovy, Nicolas; Ammann, Christof; Calanca, Pierluigi; Clifton-Brown, John; Fuhrer, Jürg; Jones, Mike; Martin, CéCile

    2007-03-01

    We improved a process-oriented biogeochemical model of carbon and nitrogen cycling in grasslands and tested it against in situ measurements of biomass and CO2 and CH4 fluxes at five European grassland sites. The new version of the model (PASIM) calculates the growth and senescence of aboveground vegetation biomass accounting for sporadic removals when the grassland is cut and for continuous removals when it is grazed. Limitations induced by high leaf area index (LAI), soil water deficits and aging of leaves are also included. We added to this a simple empirical formulation to account for the detrimental impact on vegetation of trampling and excreta by grazing animals. Finally, a more realistic methane emission module than is currently used was introduced on the basis of the quality of the animals' diet. Evaluation of this improved version of PASIM is performed at (1) Laqueuille, France, on grassland continuously grazed by cattle with two plots of intensive and extensive grazing intensities, (2) Oensingen, Switzerland, on cut grassland with two fertilized and nonfertilized plots, and (3) Carlow, Ireland, on grassland that is both cut and grazed by cattle during the growing season. In addition, we compared the modeled animal CH4 emissions with in situ measurements on cattle for two grazing intensities at the grazed grassland site of Laqueuille. Altogether, when all improvements to the PASIM model are included, we found that the new parameterizations resulted into a better fit to the observed seasonal cycle of biomass and of measured CO2 and CH4 fluxes. However, the large uncertainties in measurements of biomass and LAI make simulation of biomass dynamics difficult to make. Also simulations for cut grassland are better than for grazed swards. This work paves the way for simulating greenhouse gas fluxes over grasslands in a spatially explicit manner, in order to quantify and understand the past, present and future role of grasslands in the greenhouse gas budget of the

  15. In-situ ambient quantification of monoterpenes, sesquiterpenes, and related oxygenated compounds during BEARPEX 2007: implications for gas- and particle-phase chemistry

    NASA Astrophysics Data System (ADS)

    Bouvier-Brown, N. C.; Goldstein, A. H.; Gilman, J. B.; Kuster, W. C.; de Gouw, J. A.

    2009-08-01

    We quantified ambient mixing ratios of 9 monoterpenes, 6 sesquiterpenes, methyl chavicol, the oxygenated terpene linalool, and nopinone using an in-situ gas chromatograph with a quadrupole mass spectrometer (GC-MS). These measurements were a part of the 2007 Biosphere Effects on AeRosols and Photochemistry EXperiment (BEARPEX) at Blodgett Forest, a ponderosa pine forest in the Sierra Nevada Mountains of California. To our knowledge, these observations represent the first direct in-situ ambient quantification of the sesquiterpenes α-bergamotene, longifolene, α-farnesene, and β-farnesene. From average diurnal mixing ratio profiles, we show that α-farnesene emissions are dependent mainly on temperature whereas α-bergamotene and β-farnesene emissions are temperature- and light-dependent. The amount of sesquiterpene mass quantified above the canopy was small (averaging a total of 3.3 ppt during the day), but nevertheless these compounds contributed 7.6% to the overall ozone-olefin loss rate above the canopy. Assuming that the monoterpene-to-sesquiterpene emission rate in the canopy is similar to that observed in branch enclosure studies at the site during comparable weather conditions, and the average yield of aerosol mass from these sesquiterpenes is 10-50%, the amount of sesquiterpene mass reacted within the Blodgett Forest canopy alone accounts for 6-32% of the total organic aerosol mass measured during BEARPEX. The oxygenated monoterpene linalool was also quantified for the first time at Blodgett Forest. The linalool mass contribution was small (9.9 ppt and 0.74 ppt within and above the canopy, respectively), but it contributed 1.1% to the total ozone-olefin loss rate above the canopy. Reactive and semi-volatile compounds, especially sesquiterpenes, significantly impact the gas- and particle-phase chemistry of the atmosphere at Blodgett Forest and should be included in both biogenic volatile organic carbon emission and atmospheric chemistry models.

  16. In-situ ambient quantification of monoterpenes, sesquiterpenes, and related oxygenated compounds during BEARPEX 2007 - implications for gas- and particle-phase chemistry

    NASA Astrophysics Data System (ADS)

    Bouvier-Brown, N. C.; Goldstein, A. H.; Gilman, J. B.; Kuster, W. C.; de Gouw, J. A.

    2009-04-01

    We quantified ambient mixing ratios of 9 monoterpenes, 6 sesquiterpenes, methyl chavicol, the oxygenated terpene linalool, and nopinone using an in-situ gas chromatograph with a quadrupole mass spectrometer (GC-MS). These measurements were a part of the 2007 Biosphere Effects on AeRosols and Photochemistry EXperiment (BEARPEX) at Blodgett Forest, a ponderosa pine forest in the Sierra Nevada Mountains of California. To our knowledge, these observations represent the first direct in-situ ambient quantification of the sesquiterpenes α-bergamotene, longifolene, α-farnesene, and β-farnesene. From average diurnal mixing ratio profiles, we show that α-farnesene emissions are dependent mainly on temperature whereas α-bergamotene and β-farnesene emissions are temperature- and light-dependent. The amount of sesquiterpene mass quantified above the canopy was small (averaging a total of 3.3 ppt during the day), but nevertheless these compounds contributed 8.5% to the overall ozone reactivity above the canopy. Assuming that the monoterpene-to-sesquiterpene emission rate in the canopy is similar to that observed in branch enclosure studies at the site during comparable weather conditions, and the average yield of aerosol mass from these sesquiterpenes is 10-50%, the amount of sesquiterpene mass reacted within the Blodgett Forest canopy alone accounts for 8-38% of the total organic aerosol mass measured during BEARPEX. The oxygenated monoterpene linalool was also quantified for the first time at Blodgett Forest. The linalool mass contribution was small (9.9 ppt and 0.74 ppt within and above the canopy, respectively), but it contributed 1.2% to the total ozone reactivity above the canopy. Reactive and semi-volatile compounds, especially sesquiterpenes, significantly impact the gas- and particle-phase chemistry of the atmosphere at Blodgett Forest and should be included in both biogenic volatile organic carbon emission and atmospheric chemistry models.

  17. Early results from the development of a miniature tunable diode laser gas cell for measuring CO2 isotopologue fluxes in situ

    NASA Astrophysics Data System (ADS)

    Osuna, J. L.; Bora, M.; Bond, T.; Wharton, S.

    2014-12-01

    In order to accurately predict how ecosystems will respond to climate change, it is necessary to separate the response of respiration and photosynthetic uptake individually to environmental conditions. Currently, the net ecosystem exchange of CO2 is measured continuously at various ecosystems around the world. Net CO­2 flux can be partitioned into the primary components using either models or measurements of 13C/12C in the CO2 flux. We introduce recent technological developments toward in situ, rapid, continuous measurements of fluxes of 13CO2 and 12CO2. We describe a unique approach to achieving 10Hz measurements of CO2 using tunable diode laser gas absorption spectroscopy in a multi-pass White cell capable of being deployed directly to a canopy. We will first discuss proof-of-concept characterization of the technique using wave modulation spectroscopy with a laser tuned to detect 12CO2 fluxes. We show the sensitivity of the 2w component of a wave-modulated signal to CO2 concentration, the precision, and the accuracy of the sensor as well as the stability of the sensor under normal ranges of ambient temperature and humidity in an environmental chamber. We then show preliminary results of sensor performance with a laser tuned to measure 13CO2 and 12CO2 fluxes. We discuss our approach to reliably measuring multiple peaks of gas absorption while maintaining the rapid sampling rates necessary for flux calculations. We will also discuss considerations for extending the sensor from the lab to being directly deployed into a canopy for in situ measurements. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS- 658355

  18. Lidar data inversion for Cirrus clouds: An approach based on a statistical analysis of in situ microphysical measurements

    SciTech Connect

    Febvre, G.

    1994-10-01

    The problem of the lidar equation inversion lies in the fact that it requires a lidar calibration or else a reference value from the studied medium. This paper presents an approach to calibrate the lidar by calculating the constant Ak (lidar constant A multiplied by the ratio of backscatter coefficient to extinction coefficient k). This approach is based on statistical analysis of in situ measurements. This analysis demonstrates that the extinction coefficient has a typical probablility distribution in cirrus clouds. The property of this distribution, as far as the attenuation of laser beam in the cloud, is used as a constraint to calculate the value of Ak. The validity of this method is discussed and results compared with two other inversion methods.

  19. In Situ Time-Resolved Characterization of Novel Cu-MoO2 Catalysts During the Water-Gas Shift Reaction

    SciTech Connect

    Wen ,W.; Liu, J.; White, M.; Marinkovic, N.; Hanson, J.; Rodriguez, J.

    2007-01-01

    A novel and active Cu-MoO{sub 2} catalyst was synthesized by partial reduction of a precursor CuMoO{sub 4} mixed-metal oxide with CO or H{sub 2} at 200-250 C. The phase transformations of Cu-MoO{sub 2} during H{sub 2} reduction and the water-gas shift reaction could be followed by In situ time resolved XRD techniques. During the reduction process the diffraction pattern of the CuMoO{sub 4} collapsed and the copper metal lines were observed on an amorphous material background that was assigned to molybdenum oxides. During the first pass of water-gas shift (WGS) reaction, diffraction lines for Cu{sub 6}Mo{sub 5}O{sub 18} and MoO{sub 2} appeared around 350 C and Cu{sub 6}Mo{sub 5}O{sub 18} was further transformed to Cu/MoO{sub 2} at higher temperature. During subsequent passes, significant WGS catalytic activity was observed with relatively stable plateaus in product formation around 350, 400 and 500 C. The interfacial interactions between Cu clusters and MoO{sub 2} increased the water-gas shift catalytic activities at 350 and 400 C.

  20. In situ synthesis of porous array films on a filament induced micro-gap electrode pair and their use as resistance-type gas sensors with enhanced performances.

    PubMed

    Xu, Zongke; Duan, Guotao; Zhang, Hongwen; Wang, Yingying; Xu, Lei; Cai, Weiping

    2015-09-14

    Resistance-type metal-oxide semiconductor gas sensors with high sensitivity and low detection limit have been explored for practical applications. They require both sensing films with high sensitivity to target gases and an appropriate structure of the electrode-equipped substrate to support the sensing films, which is still challenging. In this paper, a new gas sensor of metal-oxide porous array films on a micro-gap electrode pair is designed and implemented by taking ZnO as a model material. First, a micro-gap electrode pair was constructed by sputtering deposition on a filament template, which was used as the sensor's supporting substrate. Then, the sensing film, made up of ZnO porous periodic arrays, was in situ synthesized onto the supporting substrate by a solution-dipping colloidal lithography strategy. The results demonstrated the validity of the strategy, and the as-designed sensor shows a small device-resistance, an enhanced sensing performance with high resolution and an ultralow detection limit. This work provides an alternative method to promote the practical application of resistance-type gas sensors.

  1. Sensitive Amino Acid Composition and Chirality Analysis in the Martian Regolith with a Microfabricated in situ Analyzer

    NASA Astrophysics Data System (ADS)

    Skelley, A. M.; Grunthaner, F. J.; Bada, J. L.; Mathies, R. A.

    2003-12-01

    Recent advances in microfabricated "lab-on-a-chip" technologies have dramatically enhanced the capabilities of chemical and biochemical analyzers. The portability and sensitivity of these devices makes them ideal instruments for in situ chemical analysis on other planets. We have focused our initial studies on amino acid analysis because amino acids are more chemically resistant to decomposition than other biomolecules, and because amino acid chirality is a well-defined biomarker [1]. Previously, we developed a prototype electrophoresis chip, detection system and analysis method where the amino acids were labeled with fluorescein using FITC and then electrophoretically analyzed using g-cyclodextrin as the chiral resolution agent [2]. Extracts of the Murchison meteorite were analyzed, and the D/L ratios determined by microchip CE closely matched those from HPLC and GCMS and exhibited greater precision. Our microchip analyzer has now been further improved by establishing the capability of performing amino acid composition and chirality analyses using fluorescamine rather than FITC [3]. Fluorescamine is advantageous because it reacts more rapidly than FITC, and because excess reagent is hydrolyzed to a non-fluorescent product. Furthermore, the use of fluorescamine facilitates interfacing with the Mars Organic Detector (MOD) [4]. Fluorescamine-amino acids are separated using similar conditions as the FITC-aa, resulting in similar separation times and identical elution orders. Fluorescamine-aa are chirally resolved in the presence of hydroxy-propyl-b-cyclodextrin, and typical limits of detection are ˜ 50 nM. This work establishes the feasibility of combining fluorescamine labeling of amino acids with microfabricated CE devices to develop low-volume, high-sensitivity apparatus for extraterrestrial exploration. The stage is now set for the development of the Mars Organic Analyzer (MOA), a portable analysis system for amino acid extraction and chiral analysis that will

  2. In situ observation and analysis of ultrasonic capillary effect in molten aluminium.

    PubMed

    Tzanakis, I; Xu, W W; Eskin, D G; Lee, P D; Kotsovinos, N

    2015-11-01

    An in situ synchrotron radiographic study of a molten Al-10 wt% Cu alloy under the influence of an external ultrasonic field was carried out using the Diamond-Manchester Branchline pink X-ray imaging at the Diamond Light Source in UK. A bespoke test rig was used, consisting of an acoustic transducer with a titanium sonotrode coupled with a PID-controlled resistance furnace. An ultrasonic frequency of 30 kHz, with a peak to peak amplitude at 140 microns, was used, producing a pressure output of 16.9 MPa at the radiation surface of the 1-mm diameter sonotrode. This allowed quantification of not only the cavitation bubble formation and collapse, but there was also evidence of the previously hypothesised ultrasonic capillary effect (UCE), providing the first direct observations of this phenomenon in a molten metallic alloy. This was achieved by quantifying the re-filling of a pre-existing groove in the shape of a tube (which acted as a micro-capillary channel) formed by the oxide envelope of the liquid sample. Analytical solutions of the flow suggest that the filling process, which took place in very small timescales, was related to micro-jetting from the collapsing cavitation bubbles. In addition, a secondary mechanism of liquid penetration through the groove, which is related with the density distribution of the oxides inside the groove, and practically to the filtration of aluminium melt from oxides, was revealed. The observation of the almost instantaneous re-filling of a micro-capillary channel with the metallic melt supports the hypothesised sono-capillary effect in technologically important liquids other than water, like metallic alloys with substantially higher surface tension and density. PMID:26186822

  3. In situ transcriptomic analysis of the globally important keystone N2-fixing taxon Crocosphaera watsonii.

    PubMed

    Hewson, Ian; Poretsky, Rachel S; Beinart, Roxanne A; White, Angelicque E; Shi, Tuo; Bench, Shellie R; Moisander, Pia H; Paerl, Ryan W; Tripp, H James; Montoya, Joseph P; Moran, Mary Ann; Zehr, Jonathan P

    2009-05-01

    The diazotrophic cyanobacterium Crocosphaera watsonii supplies fixed nitrogen (N) to N-depleted surface waters of the tropical oceans, but the factors that determine its distribution and contribution to global N(2) fixation are not well constrained for natural populations. Despite the heterogeneity of the marine environment, the genome of C. watsonii is highly conserved in nucleotide sequence in contrast to sympatric planktonic cyanobacteria. We applied a whole assemblage shotgun transcript sequencing approach to samples collected from a bloom of C. watsonii observed in the South Pacific to understand the genomic mechanisms that may lead to high population densities. We obtained 999 C. watsonii transcript reads from two metatranscriptomes prepared from mixed assemblage RNA collected in the day and at night. The C. watsonii population had unexpectedly high transcription of hypothetical protein genes (31% of protein-encoding genes) and transposases (12%). Furthermore, genes were expressed that are necessary for living in the oligotrophic ocean, including the nitrogenase cluster and the iron-stress-induced protein A (isiA) that functions to protect photosystem I from high-light-induced damage. C. watsonii transcripts retrieved from metatranscriptomes at other locations in the southwest Pacific Ocean, station ALOHA and the equatorial Atlantic Ocean were similar in composition to those recovered in the enriched population. Quantitative PCR and quantitative reverse transcriptase PCR were used to confirm the high expression of these genes within the bloom, but transcription patterns varied at shallower and deeper horizons. These data represent the first transcript study of a rare individual microorganism in situ and provide insight into the mechanisms of genome diversification and the ecophysiology of natural populations of keystone organisms that are important in global nitrogen cycling.

  4. Observation and Analysis of In Situ Carbonaceous Matter in Naklha. Part 2

    NASA Technical Reports Server (NTRS)

    Gibson, E. K., Jr.; Clemett, S. J.; Thomas-Kerpta, K. L.; McKay, D. S.; Wentworth, S. J.; Robert, F.; Verchovsky, A. B.; Wright, I. P.; Pillinger, C. T.; Rice, T.; VanLeer, B.

    2006-01-01

    The search for indigenous carbon components on Mars has been a challenge. The first attempt was the Viking GC-MS in situ experiment which gave inconclusive results at two sites on Mars [1]. After the discovery that the SNC meteorites were from Mars [2], [3-5] reported C isotopic compositional information which suggested a reduced C component present in the martian meteorites. [6 & 7] reported the presence of reduced C components (i.e., polycyclic aromatic hydrocarbons) associated with the carbonate globules in ALH84001. Jull et al. [8] noted in Nakhla there was an acid insoluble C component present with more than 75% of its C lacking any C-14, which is modern-day carbon. This C fraction was believed to be either indigenous martian or ancient meteoritic carbon. Fisk et al. [9, 10] have shown textural evidence along with C-enriched areas within fractures in Nakhla and ALH84001. To further understand the nature of possible indigenous reduced C components, we have carried out a variety of measurements on martian meteorites. For this presentation we will discuss only the Nakhla results. Interior samples from the Nakhla SNC meteorite, recently made available by the British Museum of Natural History, were analyzed. Petrographic examination [11, McKay et al., this volume] of Nakhla showed evidence of fractures (approx.0.5 micron wide) filled with dark brown to black dendritic material [Fig. 1] with characteristics similar to those observed by [10]. Iddingsite is also present along fractures in olivine. Fracture filling and dendritic material was examined by SEM-EDX, TEM-EDX, Focused Electron Beam microscopy, Laser Raman Spectroscopy, Nano-SIMS Ion Micro-probe, and Stepped-Combustion Static Mass Spectrometry.

  5. Calcium and magnesium transport by in situ mitochondria: electron probe analysis of vascular smooth muscle

    SciTech Connect

    Broderick, R.; Somlyo, A.P.

    1987-10-01

    The extent, time course, and reversibility of mitochondrial Ca/sup 2 +/ uptake secondary to cellular Ca/sup 2 +/ influx stimulated by massive Na+ efflux were evaluated by electron probe microanalysis of rabbit portal vein smooth muscle. Strips of portal vein were Na+ loaded for 3 hours at 37/sup 0/C in a K+-free 1 mM ouabain solution, after which rapid Na+ efflux was induced by washing with a Na+-free K+-Li+ solution (1 mM ouabain). Li+ washing Na+-loaded portal vein produced a large transient contraction accompanied by an increase (over 100-fold) in mitochondrial Ca/sup 2 +/ and also significant (p less than 0.05) increases in phosphorus and Mg/sup 2 +/. The Ca/sup 2 +/ loading of the mitochondria was reversed during prolonged Li+ wash, and by 2 hours, mitochondrial Ca/sup 2 +/, Mg/sup 2 +/, and phosphorus had returned to control levels. The maximal contractile response to stimulation remained normal, demonstrating that pathologic Ca/sup 2 +/ loading of mitochondria is reversible in situ and compatible with normal maximal force developed by the smooth muscle. Mitochondrial Ca/sup 2 +/ and phosphorus uptake were reduced but still significant when the Li+ wash contained 0.2 mM Ca/sup 2 +/ or when ouabain was omitted. The fact that mitochondrial Ca/sup 2 +/ loading accompanied submaximal contractions during 0.2 mM Ca/sup 2 +/-Li wash suggests supranormal affinity of mitochondria for Ca/sup 2 +/ and may be due, in part, to reverse operation of the mitochondrial Na+-Ca/sup 2 +/ exchanger. Mitochondrial Ca/sup 2 +/, Mg/sup 2 +/, and phosphorus uptake were eliminated when the Li+ wash was performed at 2/sup 0/C or when the wash contained no Ca/sup 2 +/.

  6. In situ DNA hybridization analysis of human papillomavirus (HPV) sequences in benign oral mucosal lesions.

    PubMed

    Syrjänen, S M; Syrjänen, K J; Happonen, R P; Lamberg, M A

    1987-01-01

    A series of 144 surgically treated benign oral mucosal lesions were analysed using an in situ DNA hybridization technique with 35S-labeled human papillomavirus (HPV) DNA probes to demonstrate the DNA of HPV types 6, 11, 13, and 16, in routinely processed, paraffin-embedded biopsy specimens. These lesions and an additional 62 benign oral mucosal biopsy specimens (total, 206 specimens) were also assessed by the indirect immunoperoxidase (IP-PAP) technique to detect the expression of HPV structural proteins (viral antigens). A total of 54/206 (26.2%) lesions were observed to express HPV antigens, being found in 45/92 (48.9%) of the squamous cell papillomas/condylomas, in 1/54 fibrous hyperplasias, in 1/8 true fibromas, and in 7/8 (87.5%) of the focal epithelial hyperplasia (FEH) lesions. Of the HPV DNA-positive lesions, 15/45 (33.3%) expressed HPV antigens, the expression not being related to any particular HPV type. HPV DNA sequences were found in 45/144 (31.3%) of the lesions. HPV DNA was present with the highest frequency in FEH (83.3%), followed by the papilloma/condyloma group (33.8%), papillary hyperplasia (28.6%), fibrous hyperplasia (24.4%), and true fibromas (14.3%). The most frequent HPV type was HPV 11, representing 37.8% of the DNA-positive lesions. HPV 13 DNA, previously regarded as specific to FEH, was disclosed as a single HPV type in seven cases, and as a double infection by HPV 11 and 13 in an additional three cases, including all five morphologically distinct entities. Noteworthy is the discovery of the high-risk HPV type 16 DNA in 17.8% of the DNA-positive lesions, four papilloma/condyloma lesions, three fibrous hyperplasias, and one FEH.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. Thermal transport in CO2 laser irradiated fused silica: in situ measurements and analysis

    SciTech Connect

    Yang, S T; Matthews, M J; Elhadj, S; Draggoo, V G; Bisson, S E

    2009-07-07

    In situ spatial and temporal temperature measurements of pristine fused silica surfaces heated with a 10.6 {micro}m CO{sub 2} laser were obtained using an infrared radiation thermometer based on a Mercury Cadmium Telluride (MCT) camera. Laser spot sizes ranged from 250 {micro}m to 1000 {micro}m diameter with peak axial irradiance levels of 0.13 to 16 kW/cm{sup 2}. For temperatures below 2800K, the measured steady-state surface temperature is observed to rise linearly with both increasing beam size and incident laser irradiance. The effective thermal conductivity estimated over this range was approximately 2W/mK, in good agreement with classical calculations based on phonon heat capacities. Similarly, time-dependent temperature measurements up to 2000K yielded thermal diffusivity values which were close to reported values of 7 x 10{sup -7} m{sup 2}/s. Above {approx}2800K, the fused silica surface temperature asymptotically approaches 3100K as laser power is further increased, consistent with the onset of evaporative heat losses near the silica boiling point. These results show that in the laser heating regime studied here, the T{sup 3} temperature dependent thermal conductivity due to radiation transport can be neglected, but at temperatures above 2800K heat transport due to evaporation must be considered. The thermal transport in fused silica up to 2800K, over a range of conditions, can then be adequately described by a linear diffusive heat equation assuming constant thermal properties.

  8. Synchrotron micro-X-ray fluorescence analysis of natural diamonds: First steps in identification of mineral inclusions in situ

    SciTech Connect

    Sitepu, Husin; Kopylova, Maya G.; Quirt, David H.; Cutler, Jeffrey N.; Kotzer, Thomas G.

    2008-06-09

    Diamond inclusions are of particular research interest in mantle petrology and diamond exploration as they provide direct information about the chemical composition of upper and lower mantle and about the petrogenetic sources of diamonds in a given deposit. The objective of the present work is to develop semi-quantitative analytical tools for non-destructive in situ identification and characterization of mineral inclusions in diamonds using synchrotron micro-X-ray Fluorescence ({mu}SXRF) spectroscopy and micro-X-ray Absorption Near Edge Structure ({mu}XANES) spectroscopy at a focused spot size of 4 to 5 micrometers. The data were collected at the Pacific Northwest Consortium (PNC-CAT) 20-ID microprobe beamline at the Advanced Photon Source, located at the Argonne National Laboratory, and yielded the first high-resolution maps of Ti, Cr, Fe, Ni, Cu, and Zn for natural diamond grains, along with quantitative {mu}SXRF analysis of select chemical elements in exposed kimberlite indicator mineral grains. The distribution of diamond inclusions inside the natural diamond host, both visible and invisible using optical transmitted-light microscopy, can be mapped using synchrotron {mu}XRF analysis. Overall, the relative abundances of chemical elements determined by {mu}SXRF elemental analyses are broadly similar to their expected ratios in the mineral and therefore can be used to identify inclusions in diamonds in situ. Synchrotron {mu}XRF quantitative analysis provides accurate estimates of Cr contents of exposed polished minerals when calibrated using the concentration of Fe as a standard. Corresponding Cr K-edge {mu}XANES analyses on selected inclusions yield unique information regarding the formal oxidation state and local coordination of Cr.

  9. Performance of a Microfluidic Device for In Situ ToF-SIMS Analysis of Selected Organic Molecules at Aqueous Surfaces

    SciTech Connect

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

    2013-04-03

    Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is a unique surface analysis technique because it can provide molecular recognition for organic and biological molecules. However, analyzing aqueous solution surfaces by ToF-SIMS is difficult, because ToF-SIMS is a high-vacuum technique, while the vapor pressure of water is about 2.3 kPa at room temperature (20 C). We designed and fabricated a self-contained microfluidic device, enabling in situ analysis of aqueous surfaces by scanning electron microscope (SEM) and ToF-SIMS, which has been briefly reported.1,2 In this study, we report more performance data, focusing on the performance of this device for in situ analysis of organic molecules at aqueous surfaces using ToF-SIMS. Three representative organic compounds (formic acid, glycerol, and glutamic acid) were tested, and their molecular signals were successfully observed. The device can be self-running in vacuum for 8 hours, and SIMS measurements are feasible at any time in this time range. The stability of this device under primary ion beam bombardment is also impressive. High fluence (6 × 1012 ions cm-2 s-1) measurements can be operated continuously for up to 30 minutes without any significant damage to the aperture. However, extra-high fluence measurements (>1 × 1014 ions cm-2 s-1) may lead to liquid bumping in the aperture, and the aqueous solutions may spread out quickly. Signal reproducibility is reasonably good, and relative standard deviation (RSD) for molecular ion signals can be controlled to be smaller than ±15% for consecutive measurements. Measurements at long time intervals (e.g., 60 min) show RSDs of ±40-50%. In addition, the detection limits of formic acid, glycerol, and glutamic acid are estimated to be 0.04%, 0.008%, and 0.002% (weight ratio), respectively.

  10. Propagation and Evolution of CMEs in the Interplanetary Medium: Analysis of Remote Sensing and In situ Observations

    NASA Technical Reports Server (NTRS)

    Figueroa-Vinas, Adolfo; Nieves-Chinchilla, Teresa; Vourlidas, Angelos; Gomez-Herrero, Raul; Malandraki, Olga; Szabo, Adam; Dresing, Nina; Davila, Joseph M.

    2010-01-01

    EUV disk imagers and white light coronagraphs have provided for many years information on the early formation and evolution of corona) mass ejections (CMEs). More recently, the novel heliospheric imaging instruments aboard the STEREO mission are providing crucial remote sensing information on the interplanetary evolution of these events while in situ instruments complete the overall characterization of the interplanetary CMEs. In this work, we present an analysis of CMEs from the Sun to the interplanetary medium using combined data from THE SOHO, STEREO, WIND, and ACE spacecraft. The events were selected to cover the widest possible spectrum of different ambient solar wind, magnetic field configurations, plasma parameters, etc. to allow uncovering those aspects that are important in understanding the propagation and evolution mechanisms of CMEs in the interplanetary medium.

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

    SciTech Connect

    Isaacs, H.S.; Kaneko, M.

    1997-12-31

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

  12. Scattering influences in quantitative fission neutron radiography for the in situ analysis of hydrogen distribution in metal hydrides

    NASA Astrophysics Data System (ADS)

    Börries, S.; Metz, O.; Pranzas, P. K.; Bücherl, T.; Söllradl, S.; Dornheim, M.; Klassen, T.; Schreyer, A.

    2015-10-01

    In situ neutron radiography allows for the time-resolved study of hydrogen distribution in metal hydrides. However, for a precise quantitative investigation of a time-dependent hydrogen content within a host material, an exact knowledge of the corresponding attenuation coefficient is necessary. Additionally, the effect of scattering has to be considered as it is known to violate Beer's law, which is used to determine the amount of hydrogen from a measured intensity distribution. Within this study, we used a metal hydride inside two different hydrogen storage tanks as host systems, consisting of steel and aluminum. The neutron beam attenuation by hydrogen was investigated in these two different setups during the hydrogen absorption process. A linear correlation to the amount of absorbed hydrogen was found, allowing for a readily quantitative investigation. Further, an analysis of scattering contributions on the measured intensity distributions was performed and is described in detail.

  13. In Situ Aerosol Optical Thickness Collected by the SIMBIOS Program (1997-2000): Protocols, and and Data QC and Analysis

    NASA Technical Reports Server (NTRS)

    Fargion, Giulietta S.; Barnes, Robert; McClain, Charles

    2001-01-01

    The purpose of this technical report is to provide current documentation of the Sensor Intercomparison and Merger for Biological and Interdisciplinary Oceanic Studies (SIMBIOS) Project Office activities on in situ aerosol optical thickness (i.e., protocols, and data QC and analysis). This documentation is necessary to ensure that critical information is related to the scientific community and NASA management. This critical information includes the technical difficulties and challenges of validating and combining ocean color data from an array of independent satellite systems to form consistent and accurate global bio-optical time series products. This technical report is not meant as a substitute for scientific literature. Instead, it will provide a ready and responsive vehicle for the multitude of technical reports issued by an operational project.

  14. INTERRELATIONSHIPS BETWEEN IN-SITU GAS HYDRATES AND HEAVY OIL OCCURRENCES ON THE NORTH SLOPE OF ALASKA.

    USGS Publications Warehouse

    Collett, T.S.

    1985-01-01

    In 1973, during the drilling of the West Sak #1 well on the North Slope of Alaska, oil was first recovered from a shallow Cretaceous sand interval which was later informally named the West Sak sands by ARCO Alaska. Stratigraphically above the West Sak sands there are two additional oil bearing sands, and are informally referred to by ARCO as the Ugnu and the 2150 horizons. Gas hydrates are interpreted to exist in the West Sak #6 well in conjunction with heavy oil and the physical properties of this oil may have been influenced by the gas hydrate. Prior to this work, only experimental evidence suggested that hydrates and oil could exist in the same reservoir.

  15. Dating prograde fluid pulses during subduction by in situ U-Pb and oxygen isotope analysis

    NASA Astrophysics Data System (ADS)

    Gauthiez-Putallaz, Laure; Rubatto, Daniela; Hermann, Jörg

    2016-02-01

    -system equilibrium fractionation during prograde to peak temperatures. The resulting equilibrium ∆18Ozircon-monazite at 700 ± 20 °C is 0.1 ± 0.7 ‰. The in situ oxygen isotope data argue against an externally derived input of fluids into the whiteschists. Instead, fluid-assisted zircon and monazite recrystallisation can be linked to internal dehydration reactions during prograde subduction. We propose that the major metasomatic event affecting the granite protolith was related to hydrothermal seafloor alteration post-dating Jurassic rifting, well before the onset of Alpine subduction.

  16. Non-destructive in-situ determination of the rare gas content of highly insulating glazing units

    SciTech Connect

    Gross, J.; Fricke, J.

    1997-11-01

    For a drastic reduction of heat transfer in glazing units low emissivity coatings and filling gases with low thermal conductivity, e.g., argon, krypton or xenon, are used. As the rim seal is not perfectly leak tight, part of the filling gas may diffuse out and air could diffuse into the spacing, resulting in a deterioration of the insulating performance. By measuring the sound velocity in the gas filling the relative amount of the noble gas can be determined. A theoretical expression for the sound velocity of an air-argon mixture is experimentally verified to 0.5%. In order to determine the krypton or xenon content to within about 10%, the sound velocity is determined by measuring changes of the travel time and the glazing spacing instead of absolute values. A change in spacing is achieved by pressing ultrasonic transducers onto the glazing unit with varying force. A sound frequency of typically 1 MHz is used for experiments carried out on a 50 x 50 cm{sup 2} argon filled double pane glazing with a spacing of 14 mm. The expected change of sound velocity with gas composition is analyzed with respect to the loss of thermal performance of the glazing. For xenon and krypton the effective U-value of the glazing can be determined from the ultrasound measurement with an uncertainty of better than 0.04 W/m{sup 2} K, whereas for argon the uncertainty with the present setup is acceptable only for higher air content of the glazing.

  17. In situ measurements of the air-sea gas transfer rate using heat as a proxy tracer

    SciTech Connect

    Haussecker, H.; Jaehne, B. |

    1994-12-31

    Conventional techniques to measure the transfer velocity k = j/{Delta}c of gases across the ocean interface are based on mass balance of the gas tracer in the water body. In order to determine j the temporal change {dot c}{sub w} of the tracer concentration in a volume of water V{sub w} has to be measured. The corresponding time constant {tau}{sub w} is in the order of days to weeks in the ocean. This long integration time prevents both an empirical parameterization of the gas transfer rate with friction velocity and other parameters such as the wave field and an insight into the mechanisms. Eddy correlation techniques are in principal suitable for flux measurements and parameterization of the gas transfer rate. So far, however, it could not be verified that they yield results that are consistent with geochemical methods and laboratory investigations. Here, an alternative approach is presented. The novel technique controls the tracer flux at the interface and uses heat as a proxy tracer.

  18. In situ x-ray photoelectron spectroscopy studies of gas/solidinterfaces at near-ambient conditions

    SciTech Connect

    Bluhm, Hendrik; Havecker, Michael; Knop-Gericke, Axel; Kiskinova,Maya; Schlogl, Robert; Salmeron, Miquel

    2007-12-03

    X-ray photoelectron spectroscopy (XPS) is a quantitative, chemically specific technique with a probing depth of a few angstroms to a few nanometers. It is therefore ideally suited to investigate the chemical nature of the surfaces of catalysts. Because of the scattering of electrons by gas molecules, XPS is generally performed under vacuum conditions. However, for thermodynamic and/or kinetic reasons, the catalyst's chemical state observed under vacuum reaction conditions is not necessarily the same as that of a catalyst under realistic operating pressures. Therefore, investigations of catalysts should ideally be performed under reaction conditions, i.e., in the presence of a gas or gas mixtures. Using differentially pumped chambers separated by small apertures, XPS can operate at pressures of up to 1 Torr, and with a recently developed differentially pumped lens system, the pressure limit has been raised to about 10 Torr. Here, we describe the technical aspects of high-pressure XPS and discuss recent applications of this technique to oxidation and heterogeneous catalytic reactions on metal surfaces.

  19. In situ derivatization and hollow fiber membrane microextraction for gas chromatographic determination of haloacetic acids in water.

    PubMed

    Varanusupakul, Pakorn; Vora-Adisak, Narongchai; Pulpoka, Bancha

    2007-08-13

    An alternative method for gas chromatographic determination of haloacetic acids (HAAs) in water using direct derivatization followed by hollow fiber membrane liquid-phase microextraction (HF-LPME) has been developed. The method has improved the sample preparation step according to the conventional US EPA Method 552.2 by combining the derivatization and the extraction into one step prior to determination by gas chromatography electron captured detector (GC-ECD). The HAAs were derivatized with acidic methanol into their methyl esters and simultaneously extracted with supported liquid hollow fiber membrane in headspace mode. The derivatization was attempted directly in water sample without sample evaporation. The HF-LPME was performed using 1-octanol as the extracting solvent at 55 degrees C for 60 min with 20% Na2SO4. The linear calibration curves were observed for the concentrations ranging from 1 to 300 microg L(-1) with the correlation coefficients (R2) being greater than 0.99. The method detection limits of most analytes were below 1 microg L(-1) except DCAA and MCAA that were 2 and 18 microg L(-1), respectively. The recoveries from spiked concentration ranged from 97 to 109% with %R.S.D. less than 12%. The method was applied for determination of HAAs in drinking water and tap water samples. The method offers an easy one step high sample throughput sample preparation for gas chromatographic determination of haloacetic acids as well as other contaminants in water. PMID:17693310

  20. An airborne infrared laser spectrometer for in-situ trace gas measurements: application to tropical convection case studies

    NASA Astrophysics Data System (ADS)

    Catoire, V.; Krysztofiak, G.; Robert, C.; Chartier, M.; Jacquet, P.; Guimbaud, C.; Hamer, P. D.; Marécal, V.

    2015-09-01

    A three-channel laser absorption spectrometer called SPIRIT (SPectromètre InfraRouge In situ Toute altitude) has been developed for airborne measurements of trace gases in the troposphere and lower stratosphere. More than three different species can be measured simultaneously with high time resolution (each 1.6 s) using three individual CW-DFB-QCLs (Continuous Wave Distributed FeedBack Quantum Cascade Lasers) coupled to a single Robert multipass optical cell. The lasers are operated in a time-multiplexed mode. Absorption of the mid-infrared radiations occur in the cell (2.8 L with effective path lengths of 134 to 151 m) at reduced pressure, with detection achieved using a HgCdTe detector cooled by Stirling cycle. The performances of the instrument are described, in particular precisions of 1, 1 and 3 %, and volume mixing ratio (vmr) sensitivities of 0.4, 6 and 2.4 ppbv are determined at 1.6 s for CO, CH4 and N2O, respectively (at 1σ confidence level). Estimated accuracies without calibration are about 6 %. Dynamic measuring ranges of about four decades are established. The first deployment of SPIRIT was realized aboard the Falcon-20 research aircraft operated by DLR (Deutsches Zentrum für Luft- und Raumfahrt) within the frame of the SHIVA (Stratospheric Ozone: Halogen Impacts in a Varying Atmosphere) European project in November-December 2011 over Malaysia. The convective outflows from two large convective systems near Borneo Island (6.0° N-115.5° E and 5.5° N-118.5° E) were sampled above 11 km in altitude on 19 November and 9 December, respectively. Correlated enhancements in CO and CH4 vmr were detected when the aircraft crossed the outflow anvil of both systems. These enhancements were interpreted as the fingerprint of transport from the boundary layer up through the convective system and then horizontal advection in the outflow. Using these observations, the fraction of boundary layer air contained in fresh convective outflow was calculated to range

  1. Development of a deep-sea laser-induced breakdown spectrometer for in situ multi-element chemical analysis

    NASA Astrophysics Data System (ADS)

    Thornton, Blair; Takahashi, Tomoko; Sato, Takumi; Sakka, Tetsuo; Tamura, Ayaka; Matsumoto, Ayumu; Nozaki, Tatsuo; Ohki, Toshihiko; Ohki, Koichi

    2015-01-01

    Spectroscopy is emerging as a technique that can expand the envelope of modern oceanographic sensors. The selectivity of spectroscopic techniques enables a single instrument to measure multiple components of the marine environment and can form the basis for versatile tools to perform in situ geochemical analysis. We have developed a deep-sea laser-induced breakdown spectrometer (ChemiCam) and successfully deployed the instrument from a remotely operated vehicle (ROV) to perform in situ multi-element analysis of both seawater and mineral deposits at depths of over 1000 m. The instrument consists of a long-nanosecond duration pulse-laser, a spectrometer and a high-speed camera. Power supply, instrument control and signal telemetry are provided through a ROV tether. The instrument has two modes of operation. In the first mode, the laser is focused directly into seawater and spectroscopic measurements of seawater composition are performed. In the second mode, a fiber-optic cable assembly is used to make spectroscopic measurements of mineral deposits. In this mode the laser is fired through a 4 m long fiber-optic cable and is focused onto the target's surface using an optical head and a linear stage that can be held by a ROV manipulator. In this paper, we describe the instrument and the methods developed to process its measurements. Exemplary measurements of both seawater and mineral deposits made during deployments of the device at an active hydrothermal vent field in the Okinawa trough are presented. Through integration with platforms such as underwater vehicles, drilling systems and subsea observatories, it is hoped that this technology can contribute to more efficient scientific surveys of the deep-sea environment.

  2. Laser-produced plasma sensor-probe system for in situ molten metal analysis. Final technical report

    SciTech Connect

    Kim, Y.W.

    1997-01-28

    The radically new methodology of in-situ laser-produced plasma (LPP) analysis of molten metals, as developed at Lehigh University, has been implemented into an LPP sensor-probe system, ready for deployment at steelmaking facilities. The system consists of an LPP sensor-probe head, which is immersed into the molten metal bath for the short duration of measurement, a control console, an umbilical cord connecting the above two units, and a support console providing coolants and pneumatic supports to the control console. The Department of Energy funding has supported Phase III-A and -B of the project in a joint sponsorship with AISI, CTU 5-2 Consortium, and Lehigh University. The objectives have been to: (1) implement the molten metal calibration protocol for the LPP analysis methodology; (2) implement the methodology in the form of a second-generation LPP sensor-probe system, which facilitates real-time process control by in-situ determination of elemental composition of molten steel alloys; (3) deploy such developmental systems in steelmaking facilities; (4) upgrade the systems to a third-generation design; and (5) effect technology transfer by selecting a manufacturer of commercial LPP sensor-probe systems. Four of the five objectives have been fully met. The deployment objective has been partially realized at present. The full LPP sensor-probe system has been put through trial immersion runs at a foundry, but its deployment at steelmaking facilities has progressed to a stage where various issues of financial and legal nature are being codified into a formal agreement between a host site and Lehigh University.

  3. In Situ Reactivity and TOF SIMS Analysis of Surfaces Prepared by Soft and Reactive Landing of Mass Selected Ions

    SciTech Connect

    Johnson, Grant E.; Lysonski, Michael; Laskin, Julia

    2010-07-01

    An instrument has been designed and constructed that enables in situ reactivity and time of flight secondary ion mass spectrometry (TOF-SIMS) analysis of surfaces prepared or modified through soft- and reactive landing of mass-selected polyatomic cations and anions. The apparatus employs an electrospray ion source coupled to a high transmission electrodynamic ion funnel, two focusing collision quadrupoles, a large 19 mm diameter quadrupole mass filter, and a quadrupole bender that deflects the ion beam, thereby preventing neutral contaminants from impinging on the deposition surface. The ion soft landing apparatus is coupled to a commercial TOF-SIMS instrument permitting the introduction of surfaces into vacuum and SIMS analysis before and after ion deposition without breaking vacuum. To facilitate a comparison of the current TOF-SIMS instrument with the in situ Fourier transform ion cyclotron resonance (FT-ICR-SIMS) deposition apparatus constructed previously, dications of the cyclic peptide Gramicidin S (GS) and the photoactive organonometallic complex ruthenium tris-bipyridine (Ru(bpy)3) were soft landed onto fluorinated self-assembled monolayer (FSAM) on gold surfaces. In both cases similarities and differences were observed in the secondary ion mass spectra, with the TOF-SIMS results, in general, characterized by greater sensitivity, larger dynamic range, less fragmentation, and fewer in-plume reactions than the corresponding FT-ICR-SIMS spectra. The charge reduction kinetics of both the doubly and singly protonated GS cations on the FSAM surface were also examined as was the influence of the primary gallium ion (Ga+) flux on the efficiency of these processes. In addition, we demonstrate that the new instrument enables detailed studies of the reactivity of catalytically active species immobilized by soft- and reactive landing towards gaseous reagents.

  4. Variation in ruminal in situ degradation of crude protein and starch from maize grains compared to in vitro gas production kinetics and physical and chemical characteristics.

    PubMed

    Seifried, Natascha; Steingaß, Herbert; Schipprack, Wolfgang; Rodehutscord, Markus

    2016-10-01

    The objectives of this study were (1) to evaluate in situ ruminal dry matter (DM), crude protein (CP) and starch degradation characteristics and in vitro gas production (GP) kinetics using a set of 20 different maize grain genotypes and (2) to predict the effective degradation (ED) of CP and starch from chemical and physical characteristics alone or in combination with in vitro GP measurements. Maize grains were characterised by different chemical and physical characteristics. Ruminal in situ degradation was measured in three lactating Jersey cows. Ground grains (sieve size: 2 mm) were incubated in bags for 1, 2, 4, 8, 16, 24, 48 and 72 h. Bag residues were analysed for CP and starch content. Degradation kinetics was determined and the ED of DM, CP and starch calculated using a ruminal passage rate of 5%/h and 8%/h. The GP of the grains (sieve size: 1 mm) was recorded after 2, 4, 6, 8, 12, 24, 48 and 72 h incubation in buffered rumen fluid and fitted to an exponential equation to determine GP kinetics. Correlations and stepwise multiple linear regressions were evaluated for the prediction of ED calculated for a passage rate of 5%/h (ED5) for CP (EDCP5) and starch (EDST5). The in situ parameters and ED5 varied widely between genotypes with average values (±SD) of 64% ± 4.2, 62% ± 4.1 and 65% ± 5.2 for ED5 of DM, EDCP5 and EDST5 and were on average 10 percentage points lower for a passage rate of 8%/h. Degradation rates varied between 4.8%/h and 7.4%/h, 4.1%/h and 6.5%/h and 5.3%/h and 8.9%/h for DM, CP and starch, respectively. These rates were in the same range as GP rates (6.0-8.3%/h). The EDCP5 and EDST5 were related to CP concentration and could be evaluated in detail using CP fractions and specific amino acids. In vitro GP measurements and GP rates correlated well with EDCP5 and EDST5 and predicted EDCP5 and EDST5 in combination with the chemical characteristics of the samples. Equations can be used to obtain quick and cost effective information

  5. EQUILGAS: Program to estimate temperatures and in situ two-phase conditions in geothermal reservoirs using three combined FT-HSH gas equilibria models

    NASA Astrophysics Data System (ADS)

    Barragán, Rosa María; Núñez, José; Arellano, Víctor Manuel; Nieva, David

    2016-03-01

    Exploration and exploitation of geothermal resources require the estimation of important physical characteristics of reservoirs including temperatures, pressures and in situ two-phase conditions, in order to evaluate possible uses and/or investigate changes due to exploitation. As at relatively high temperatures (>150 °C) reservoir fluids usually attain chemical equilibrium in contact with hot rocks, different models based on the chemistry of fluids have been developed that allow deep conditions to be estimated. Currently either in water-dominated or steam-dominated reservoirs the chemistry of steam has been useful for working out reservoir conditions. In this context, three methods based on the Fischer-Tropsch (FT) and combined H2S-H2 (HSH) mineral-gas reactions have been developed for estimating temperatures and the quality of the in situ two-phase mixture prevailing in the reservoir. For these methods the mineral buffers considered to be controlling H2S-H2 composition of fluids are as follows. The pyrite-magnetite buffer (FT-HSH1); the pyrite-hematite buffer (FT-HSH2) and the pyrite-pyrrhotite buffer (FT-HSH3). Currently from such models the estimations of both, temperature and steam fraction in the two-phase fluid are obtained graphically by using a blank diagram with a background theoretical solution as reference. Thus large errors are involved since the isotherms are highly nonlinear functions while reservoir steam fractions are taken from a logarithmic scale. In order to facilitate the use of the three FT-HSH methods and minimize visual interpolation errors, the EQUILGAS program that numerically solves the equations of the FT-HSH methods was developed. In this work the FT-HSH methods and the EQUILGAS program are described. Illustrative examples for Mexican fields are also given in order to help the users in deciding which method could be more suitable for every specific data set.

  6. Investigation of greenhouse gas emissions from a landfill site and agriculture in the UK by deployment of an in-situ FTIR

    NASA Astrophysics Data System (ADS)

    Sonderfeld, Hannah; Humpage, Neil; Jeanjean, Antoine; Leigh, Roland; Allen, Grant; Boesch, Hartmut

    2016-04-01

    The main greenhouse gases (GHG) emitted by human activities in the UK are carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). Understanding and quantifying their emissions is essential to monitor and guide emission reduction measures. The GAUGE (Greenhouse gAs Uk and Global Emissions) project funded by NERC aims to improve the knowledge of the UK GHG budget by an extensive measurement program. In this presentation, we focus on two important sources of these GHG: Waste and agricultural sector. We are presenting data from the deployment of an in-situ FTIR (Ecotech) for continuous and simultaneous sampling of CO2, CH4, N2O and CO with a high time resolution in the order of minutes. During a two week field campaign at a landfill site near Ipswich in August 2014, measurements were taken within a radius of 320 m of the uncovered and active area of the landfill, which was still filled with new incoming waste. The data are analysed in detail for emission ratios of CH4 to CO2. Thereby a consistent ratio in favour of CO2 is found for these emissions. We have applied a computation fluid dynamics (CFD) model, constrained with local wind measurements and a detailed topographic map of the landfill site, to the in-situ concentration data to calculate emission fluxes of the active site. Since October 2014 the FTIR has been sampling from a church tower in Glatton as part of a near surface sampling network in East Anglia focusing on regional GHG emissions from agriculture. The site is mainly influenced by south westerly winds. A clear diurnal cycle is observed in summer for CO2, CH4 and N2O, which is less pronounced in the winter months. A simulation of the methane and nitrous oxide concentrations through application of the NAME model to the EDGAR and NAEI emission inventories illustrates some shortcomings in the available emission inventories for the probed region.

  7. Experimental and numerical comparison of extractive and in situ laser measurements of non-equilibrium carbon monoxide in lean-premixed natural gas combustion

    SciTech Connect

    Nguyen, Q.V.; Edgar, B.L.; Dibble, R.W.; Gulati, A.

    1995-02-01

    Measurements of carbon monoxide (CO) in the high-temperature combustion product stream of an atmospheric pressure, lean-premixed combustion, natural gas reactor were obtained using line-of-sight tunable diode laser absorption and extractive probe sampling in conjunction with nondispersive infrared analyzers over various equivalence ratios and flow residence times. The measurements are compared with (1) a numerical model using comprehensive chemical kinetics for methane combustion in conjunction with perfectly stirred reactor (PSR) and plug-flow reactor (PFR) modeling approaches, and (2) chemical equilibrium at the measured temperatures. Temperatures ranging from 1,500 to 2,000 K were measured using a radiation corrected thermocouple and also by a diode laser thermometry technique. The laser based in situ measurements of CO concentration ranged from 50 to 5,000 ppm depending on the equivalence ratio and flow residence time. Results of the numerical model were consistent with the laser-based measurements. The extractive probe measurements were found to be as much as 10 times less than the laser-based measurements. However, laser and probe measurements for fuel-rich equivalence ratios agreed. In an effort to improve the performance of extractive sampling probes, the authors tested several aerodynamic quench probe designs. They were unable to achieve an aerodynamic quench of the CO in a high-temperature combustion product stream. A model of the sampling probe as a PFR indicates that extractive sampling of [CO] is increasingly inaccurate at gas temperatures above 1,000 K.

  8. Quantification of Gas-Wall Partitioning in Teflon Environmental Chambers Using Rapid Bursts of Low-Volatility Oxidized Species Generated in Situ.

    PubMed

    Krechmer, Jordan E; Pagonis, Demetrios; Ziemann, Paul J; Jimenez, Jose L

    2016-06-01

    Partitioning of gas-phase organic compounds to the walls of Teflon environmental chambers is a recently reported phenomenon than can affect the yields of reaction products and secondary organic aerosol (SOA) measured in laboratory experiments. Reported time scales for reaching gas-wall partitioning (GWP) equilibrium (τGWE) differ by up to 3 orders of magnitude, however, leading to predicted effects that vary from substantial to negligible. A new technique is demonstrated here in which semi- and low-volatility oxidized organic compounds (saturation concentration c* < 100 μg m(-3)) were photochemically generated in rapid bursts in situ in an 8 m(3) environmental chamber, and then their decay in the absence of aerosol was measured using a high-resolution chemical ionization mass spectrometer (CIMS) equipped with an "inlet-less" NO3(-) ion source. Measured τGWE were 7-13 min (rel. std. dev. 33%) for all compounds. The fraction of each compound that partitioned to the walls at equilibrium follows absorptive partitioning theory with an equivalent wall mass concentration in the range 0.3-10 mg m(-3). Measurements using a CIMS equipped with a standard ion-molecule reaction region showed large biases due to the contact of compounds with walls. On the basis of these results, a set of parameters is proposed for modeling GWP in chamber experiments. PMID:27138683

  9. Optical gas analysis in medicine

    NASA Astrophysics Data System (ADS)

    Pockrand, I.

    Infrared optical gas analysis methods for analysis and monitoring of gases for narcosis and artificial respiration are described. The advantages of IR absorption measurements for gas concentration determination are demonstrated. The medical quality, requirements for measuring equipment for continuous breathing gas analysis are fulfilled by IR systems. Desirable improvements mainly concern weight and volume of the measuring head, and the simultaneous determination of all relevant gases with a single measuring head. This requires an extension of the practically usable spectral range into the middle IR, where the volatile anesthetics show substantially stronger absorption bands. This extension is only successful if for the longer wavelength spectral range efficient emitters and stable, fast detectors can be used, whose power characteristics approach these of presently available component in the range between 3 and 4.5 micrometers.

  10. Comparison of in-situ FISH measurements of water vapor in the UTLS with ECMWF (re)analysis data

    NASA Astrophysics Data System (ADS)

    Kunz, A.; Spelten, N.; Konopka, P.; Müller, R.; Forbes, R. M.; Wernli, H.

    2014-06-01

    An evaluation of water vapor in the UTLS in the atmospheric ERA-Interim reanalysis data set is presented by using in-situ measurements from a large set of airborne measurement campaigns from 2001 to 2011 in the tropics, midlatitudes and polar regions. Water vapor measurements are derived from the Fast In-situ Stratospheric Hygrometer (FISH) and cover isentropic layers from 300-400 K (5-18 km). At the same time, the improvement of the ECMWF assimilation scheme representation of water vapor is addressed for time periods representing different cycles of the Integrated Forecast System (IFS). The ratio Δ(H2O) = H2OERA / H2OFISH is used as a simple measure for the difference between observations and the reanalyses. Overall, the reanalysis data reproduce around 87% of all FISH measurements within Δ(H2O) = 0.5-2, and 30% are within Δ(H2O) = 1.0 ± 0.1. Nevertheless, also strong over- and underestimations occur both in the troposphere and in the stratosphere. Δ(H2O) values indicate deviations of factors up to 10, with lower deviations in the stratosphere (Δ(H2O) = 0.5-4) than in the troposphere (Δ(H2O) = 0.5-10). In the tropical stratosphere the ratio is closer to 1 (Δ(H2O) = 0.5-2) than in the extratropical stratosphere where strong deviations occur (Δ(H2O) = 0.1-4). When considering operational analysis data, the agreement with FISH improves over the time, in particular when comparing water vapor fields for time periods before 2004 and after 2010. It appears that influences of tropical tropospheric and extratropical lower stratospheric processes on the water vapor distribution in the UTLS are particularly challenging, resulting in an overestimation of low and underestimation of high water vapor mixing ratios.

  11. In situ-ATR-FTIR analysis on the uptake and release of streptomycin from polyelectrolyte complex layers

    NASA Astrophysics Data System (ADS)

    Torger, B.; Müller, M.

    2013-03-01

    In-situ ATR-FTIR spectroscopy and line shape analysis of the diagnostic spectral region was used to quantify the bound amount and release of the antibiotic streptomycin (STRP) at polyelectrolyte (PEL) multilayers (PEM) of poly(ethyleneimine) (PEI) and poly(acrylic acid) (PAA) or PEI and sodium alginate (ALG). Unlike common concepts based on the drug enrichment of the release medium, this analytical concept allowed to measure quantitatively the drug depletion in the delivery matrix. The measured kinetic in situ ATR-FTIR data were analysed by a modified Korsmeyer-Peppas equation based on two characteristic release parameters k and n. As main experimental parameters the number of PEL layers (adsorption steps) z and the STRP/PEL ratio were varied. For z = 8 the STRP/PEL ratio showed the most significant influence on release kinetics, whereby for STRP/PEL = 1:25 slowest (n = 0.77) and lowest (k = 21.4%) and for STRP/PEL = 1:5 most rapid (n = 0.30) and highest (k = 58.6%) drug releases were found. PEM-PEI/ALG-8 (STRP/PEL = 1:5) revealed slower release rates (n = 0.58) and lower released STRP amounts (k = 17.1%) compared to PEI/PAA. UV-VIS data on time dependent STRP enrichment of the release medium showed a similar trend compared to respective ATR-FTIR data on STRP depletion in PEM. Released amounts of around 1-2 mg from the herein introduced PEM films could be determined. The introduced analytical concept will be used as screening tool for other drugs, drug eluting films and bone substituting materials.

  12. Space science technology: In-situ science. Sample Acquisition, Analysis, and Preservation Project summary

    NASA Technical Reports Server (NTRS)

    Aaron, Kim

    1991-01-01

    The Sample Acquisition, Analysis, and Preservation Project is summarized in outline and graphic form. The objective of the project is to develop component and system level technology to enable the unmanned collection, analysis and preservation of physical, chemical and mineralogical data from the surface of planetary bodies. Technology needs and challenges are identified and specific objectives are described.

  13. Gene expression analysis in sections and tissue microarrays of archival tissues by mRNA in situ hybridization.

    PubMed

    Henke, R T; Maitra, A; Paik, S; Wellstein, A

    2005-01-01

    Altered expression of genes in diseased tissues can prognosticate a distinct natural progression of the disease as well as predict sensitivity or resistance to particular therapies. Archival tissues from patients with a known medical history and treatments are an invaluable resource to validate the utility of candidate genes for prognosis and prediction of therapy outcomes. However, stored tissues with associated long-term follow-up information typically are formalin-fixed, paraffin-embedded specimen and this can severely restrict the methods applicable for gene expression analysis. We report here on the utility of tissue microarrays (TMAs) that use valuable tissues sparingly and provide a platform for simultaneous analysis of gene expression in several hundred samples. In particular, we describe a stable method applicable to mRNA expression screening in such archival tissues. TMAs are constructed from sections of small drill cores, taken from tissue blocks of archival tissues and multiple samples can thus be arranged on a single microscope slide. We used mRNA in situ hybridization (ISH) on >500 full sections and >100 TMAs for >10 different cDNAs that yielded >10,000 data points. We provide detailed experimental protocols that can be implemented without major hurdles in a molecular pathology laboratory and discuss quantitative analysis and the advantages and limitations of ISH. We conclude that gene expression analysis in archival tissues by ISH is reliable and particularly useful when no protein detection methods are available for a candidate gene.

  14. Multichannel capillary electrophoresis microdevice and instrumentation for in situ planetary analysis of organic molecules and biomarkers.

    PubMed

    Benhabib, Merwan; Chiesl, Thomas N; Stockton, Amanda M; Scherer, James R; Mathies, Richard A

    2010-03-15

    The Multichannel Mars Organic Analyzer (McMOA), a portable instrument for the sensitive microchip capillary electrophoresis (CE) analysis of organic compounds such as amino acid biomarkers and polycyclic aromatic hydrocarbons (PAHs), is developed. The instrument uses a four-layer microchip, containing eight CE analysis systems integrated with a microfluidic network for autonomous fluidic processing. The McMOA has improved optical components that integrate 405 nm laser excitation with a linear-scanning optical system capable of multichannel real-time fluorescence spectroscopic analysis. The instrumental limit of detection is 6 pM (glycine). Microfluidic programs are executed to perform the automated sequential analysis of an amine-containing sample in each channel as well as eight consecutive analyses of alternating samples on the same channel, demonstrating less than 1% cross-contamination. The McMOA is used to identify the unique fluorescence spectra of nine components in a PAH standard and then applied to the analysis of a sediment sample from Lake Erie. The presence of benzo[a]pyrene and perylene in this sample is confirmed, and a peak coeluting with anthanthrene is disqualified based on spectral analysis. The McMOA exploits lab-on-a-chip technologies to fully integrate complex autonomous operations demonstrating the facile engineering of microchip-CE platforms for the analysis of a wide variety of organic compounds in planetary exploration.

  15. Analysis of in-situ electrical conductivity data from the HFIR TRIST-ER1 experiment

    SciTech Connect

    Zinkle, S.J.; Snead, L.L.; Shikama, T.

    1997-08-01

    The current vs. applied voltage data generated from the HFIR TRIST-ER1 experiment have been analyzed to determine the electrical conductivity of the 15 aluminum oxide specimens and the MgO-insulated electrical cables as a function of irradiation dose. With the exception of the 0.05%Cr-doped sapphire (ruby) specimen, the electrical conductivity of the alumina specimens remained at the expected radiation induced conductivity (RIC) level of <10{sup -6} S/m during full-power reactor irradiation (10-16 kGy/s) at 450-500{degrees}C up to a maximum dose of {approximately}3 dpa. The ruby specimen showed a rapid initial increase in conductivity to {approximately}2 x 10{sup -4} S/m after {approximately}0.1 dpa, followed by a gradual decrease to <1 x 10{sup -6} S/m after 2 dpa. Nonohmic electrical behavior was observed in all of the specimens, and was attributed to preferential attraction of ionized electrons in the capsule gas to the unshielded low-side bare electrical leads emanating from the subcapsules. The electrical conductivity was determined from the slope of the specimen current vs. voltage curve at negative voltages, where the gas ionization effect was minimized. Dielectric breakdown tests performed on unirradiated mineral-insulated coaxial cables identical to those used in the high voltage coaxial cables during the 3-month irradiation is attributable to thermal dielectric breakdown in the glass seals at the end of the cables, as opposed to a radiation-induced electrical degradation (RIED) effect.

  16. The relationship between ocean surface turbulence and air-sea gas transfer velocity: An in-situ evaluation

    NASA Astrophysics Data System (ADS)

    Esters, L.; Landwehr, S.; Sutherland, G.; Bell, T. G.; Saltzman, E. S.; Christensen, K. H.; Miller, S. D.; Ward, B.

    2016-05-01

    Although the air-sea gas transfer velocity k is usually parameterized with wind speed, the so-called small-eddy model suggests a relationship between k and ocean surface dissipation of turbulent kinetic energy ɛ. Laboratory and field measurements of k and ɛ have shown that this model holds in various ecosystems. Here, field observations are presented supporting the theoretical model in the open ocean. These observations are based on measurements from the Air-Sea Interaction Profiler and eddy covariance CO2 and DMS air-sea flux data collected during the Knorr11 cruise. We show that the model results can be improved when applying a variable Schmidt number exponent compared to a commonly used constant value of 1/2. Scaling ɛ to the viscous sublayer allows us to investigate the model at different depths and to expand its applicability for more extensive data sets.

  17. Measuring in situ dissolved methane concentrations in gas hydrate-rich systems, Part 1: Investigating the correlation between tectonics and methane release from sediments

    NASA Astrophysics Data System (ADS)

    Lapham, L.; Wilson, R. M.; Paull, C. K.; Chanton, J.; Riedel, M.

    2010-12-01

    In 2009, an area of extended methane venting at 1200 meters water depth was found with high resolution AUV bathymetry scans on the Northern Cascadia Margin that was previously unknown. When visited by ROV, we found seafloor cracks with active bubble streams and thin bacterial mats suggesting shallow gas and possible pore-fluid saturation. Upon coring into the cracks, a hard-substrate (carbonate or gas hydrate) was punctured and gas flows began. With these observations, we asked the question “is this shallow gas released from the seafloor from regional tectonic activity, and, if so, what is the temporal variability of such release events?” To answer this, we deployed a long term pore-water collection device at one of these gas crack sites, informally named “bubbly gulch”, for 9 months. The device is made up of 4 OsmoSamplers that were each plumbed to a port along a 1-meter probe tip using small diameter tubing. By osmosis, the samplers collected water samples slowly through the ports and maintained them within a 300 meter-long copper tubing coil. Because of the high methane concentrations anticipated, in situ pressures were maintained within the coil by the addition of a high pressure valve. Water samples were collected from the overlying water, at the sediment-water interface, and 6 and 10 cm into the sediments. Bottom water temperatures were also measured over the time series to determine pumping rates of the samplers but also to look for any temporal variability. In May 2010, the samplers were retrieved by ROV during efforts to install seafloor instruments for Neptune Canada. In a land-based lab, the coils were sub-sampled by cutting every 4 meters of tubing. With a pumping rate of 0.5 mL/day, this allowed a temporal resolution of 6 days. To date, one sampler coil has been sub-sampled and measured for methane concentrations and stable carbon isotopes. Preliminary results from this coil show pore-fluids nearly saturated with respect to methane, ~45 m

  18. An In situ Analysis of the Dissolution Characteristics of Half Pitch Line and Space Extreme Ultraviolet Lithography Resist Patterns

    NASA Astrophysics Data System (ADS)

    Santillan, Julius Joseph; Itani, Toshiro

    2013-06-01

    The characterization of the resist dissolution is one fundamental area of research that has been continuously investigated. This paper focuses on the preliminary work on the application the high speed atomic force microscope (HS-AFM) for the in situ dissolution analysis half-pitch (hp) lines and spaces (L/S) at standard developer concentration. In earlier works, this has been difficult but through extensive optimization and the use of carbon nano fiber-tipped cantilevers, the dissolution characterization of a 32 nm hp L/S pattern at 0.26 N aqueous tetramethylammonium hydroxide developer (standard developer concentration) was successfully achieved. Based on the results obtained using the EIDEC standard resist (ESR1) it was found that regardless of analysis condition such as resist pattern configuration (isolated or L/S pattern) and developer concentration (diluted or standard), similar dissolution characteristics in the form of resist swelling of exposed areas was observed. Moreover, further investigations using other types of model resist polymer platforms such as poly(hydroxystyrene) (PHS)-based and hybrid (PHS-methacryl)-based model resists have confirmed that dissolution behavior is not affected by the analysis conditions applied.

  19. Stratospheric Sampling and In Situ Atmospheric Chemical Element Analysis During Meteor Showers: A Resource Study

    NASA Technical Reports Server (NTRS)

    Noever, David A.

    2000-01-01

    Resources studies for asteroidal mining evaluation have depended historically on remote sensing analysis for chemical elements. During the November 1998 Leonids meteor shower, a stratospheric balloon and various low-density capture media were used to sample fragments from Comet Tempel-Tuttle debris during a peak Earth crossing. The analysis not only demonstrates how potential sampling strategies may improve the projections for metals or rare elements in astromining, but also benchmarks materials during low temperature (-60 F), high dessication environments as seen during atmospheric exposure. The results indicate high aluminum, magnesium and iron content for various sampled particles recovered, but generalization to the sporadic meteors expected from asteroidal sources will require future improvements in larger sampling volumes before a broad-use strategy for chemical analysis can be described. A repeat of the experimental procedure is planned for the November 1999 Leonids' shower, and various improvements for atmospheric sampling will be discussed.

  20. Field Studies Show That In Situ Greenhouse Gas Emission Factors for East African Agriculture Are Less Than IPCC Values

    NASA Astrophysics Data System (ADS)

    Pelster, D.; Butterbach-Bahl, K.; Rufino, M.; Rosenstock, T. S.; Wanyama, G.

    2015-12-01

    Greenhouse gas (GHG) emissions from African agricultural systems are thought to comprise a large portion of total emissions from the continent, however these estimates have been calculated using emission factors (EF) from other regions due to the lack of field studies in Africa, which results in large uncertainties for these estimates. Field measurements from western Kenya calculating emissions over a year in 59 different sites found that GHG emissions from typical smallholder farms ranged from 2.8 to 15.0 Mg CO2-C ha-1, -6.0 to 2.4 kg CH4-C ha-1 and -0.1 to 1.8 kg N2O-N ha-1, and were not affected by management intensity. The lack of a response in N2O emissions to N fertilization suggests that the EF currently used in national inventories overestimates N2O emissions from typical smallholder agriculture. Another study measuring N2O and CH4 emissions from manure deposited by grazing cattle found that the N2O EF ranged from 0.1 to 0.2%, while the CH4 EF ranged from 0.04 to 0.14 Kg CH4-C per 173 kg animal. These suggest that the current IPCC EF overestimate agricultural soil and manure GHG emissions for Kenya, and likely for much of East Africa.

  1. In Situ Measurement of Epidermal Cell Turgor, Leaf Water Potential, and Gas Exchange in Tradescantia virginiana L. 1

    PubMed Central

    Shackel, Kenneth A.; Brinckmann, Enno

    1985-01-01

    A combined system has been developed in which epidermal cell turgor, leaf water potential, and gas exchange were determined for transpiring leaves of Tradescantia virginiana L. Uniform and stable values of turgor were observed in epidermal cells (stomatal complex cells were not studied) under stable environmental conditions for both upper and lower epidermises. The changes in epidermal cell turgor that were associated with changes in leaf transpiration were larger than the changes in leaf water potential, indicating the presence of transpirationally induced within-leaf water potential gradients. Estimates of 3 to 5 millimoles per square meter per second per megapascal were obtained for the value of within-leaf hydraulic conductivity. Step changes in atmospheric humidity caused rapid changes in epidermal cell turgor with little or no initial change in stomatal conductance, indicating little direct relation between stomatal humidity response and epidermal water status. The significance of within-leaf water potential gradients to measurements of plant water potential and to current hypotheses regarding stomatal response to humidity is discussed. PMID:16664210

  2. In situ Detection and Habitat Characteristics Analysis of Anammox Bacteria in Sediments from River-network Area, Yangtze River Delta

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Ruan, X.; Ao, J.; Ma, T.

    2010-12-01

    Anammox (anaerobic ammonium oxidation) is the conversation of NO2-and NH4+ to N2 in anaerobic condition processed by anammox bacteria. Recently, anammox bacteria has been identified in many different freshwater systems around the world. However, Many reports have only focused on the distribution and diversity of anammox bacteria in freshwater systems, little is known about the habitat characteristics of sediments suitable for anammox bacteria. Yangtze River Delta, located in the east of China, has many shallow lakes and river networks. In this study, 41 sediment samples were collected from three typical study areas (shallow lake, regional river and urban rivers) for in situ detection of anammox bacteria and physical-chemical analysis of deposital environment of sediments. Anammox specified sequences were analyzed by PCR amplification of the 16S rRNA from the sediments. Phylogentic analysis revealed that sequences from shallow lakes and regional rivers were related to 'Candidatus Brocadia fulgida', 'Candidatus Brocadia anammoxidans' and 'Candidatus Scalindua', and most of the sequences were affiliated to'Candidatus Brocadia'. No sequence was amplified from urban river's sediments. Principal Components and Classification Analysis (PCCA) of all samples shows that, 13 sites from shallow lake fell in the same set, and 28 samples from the rivers differed from each other. The nitrogen concentration of porewater from the sediments where anammox bacteria were detected in situ are: NH4+-N 6.5~33.71mg/L, NO2--N 0~0.22 mg/L, NO3--N 0.08~3.27mg/L, and the ammonium is the main form of inorganic nitrogen. The total organic carbon (TOC) in porewater varied from 15.07 mg/L to 500.49 mg/L, and the loss on ignition (LOI) in sediments is 3.9%~10.0%. The physical-chemical parameters of deposital environment of urban rivers fell in the former range, but no anammox bacteria was detected from the samples. Further study of the biological characteristics of the bacteria is needed.

  3. In-Situ Analysis of the Phobos Surface Mineralogy by the Mössbauer Spectrometer MIMOS II on Phobos Grunt.

    NASA Astrophysics Data System (ADS)

    Blumers, Mathias; Rodionov, Daniel; Klingelhöfer, Göstar; Evlanov, Evgeny; Bernhardt, Bodo; Fleischer, Iris; Girones-Lopez, Jordi; Maul, Jasmine; Duston, Claude; Shlyk, A.

    Müssbauer spectroscopy is a powerful tool for quantitative mineralogical analysis of Fe bearing materials. The miniature Müssbauer spectrometer MIMOS II [1] is a component of the Athena science payload on board of the two Mars Exploration Rovers currently working on the Martian surface. Both MIMOS instruments are still operational after 6 years of mission with a total integration time over 1 year. The MER mission has proven that Müssbauer spectroscopy is a valuable technique for the in situ exploration of extraterrestrial bodies and the study of Fe-bearing samples [2,3]. Currently MIMOS II is part of scientific payload of the "Phobos-Grunt"-Russian sample return mission to Phobos, one of the moons of Mars. Originally, "Phobos-Grunt" was scheduled to launch in October 2009, but the launch was delayed to 2011 for additional testing of the spacecraft and payload to ensure mission success. Mission goals are: (i) Sample return. for Laboratory analysis of Phobos surface material delivered to Earth; (ii) In situ and remote studies of Phobos surface including analysis of soil samples; (3) Exploration of Phobos and its ambient space from an orbiter. MIMOS II is mounted on the robotic arm (on the landing module). Scientific objectives are: (i) Identification of iron-bearing phases (e.g., oxides, silicates, sulfides, sulfates, and carbonates); (ii) Quantitative measurement of the distribution of iron among those phases; (iii) Quantitative measurement of the distribution of iron among its oxidation states. The Müssbauer spectrometer for "Phobos-Grunt" is based on the MER version [1] with some modifications and improvements. A number of improvements were made to ensure optimal instrument performance at low temperatures (down to -150 C). Acknowledgments: Funded by German Space Agency DLR under contract 50 QM 0703. Support by the Russian Space Agency is acknowledged. References: [1] Klingelhoefer et al., JGR. 108(E12) (2003), [2] Morris et al., JGR111 (2006), [3] Morris et al

  4. In-situ sampling of a large-scale particle simulation for interactive visualization and analysis

    SciTech Connect

    Woodring, Jonathan L; Ahrens, James P; Heitmann, Katrin

    2010-12-09

    We propose storing a random sampling of data from large scale particle simulations, such as the Roadrunner Universe MC{sup 3} cosmological simulation, to be used for interactive post-analysis and visualization. Simulation data generation rates will continue to be far greater than storage bandwidth rates and other limiting technologies by many orders of magnitude. This implies that only a very small fraction of data generated by the simulation can ever be stored and subsequently post-analyzed. The limiting technology in this situation is analogous to the problem in many population surveys: there aren't enough human resources to query a large population. To cope with the lack of resources, statistical sampling techniques are used to create a representative data set of a large population. Mirroring that situation, we propose to store a simulation-time random sampling of the particle data to cope with the bOlllenecks and support interactive, exploratory post-analysis. The particle samples are immediately stored in a level-ol-detail format for post-visualization and analysis, which amortizes the cost of post-processing for interactive visualization. Additionally, we incorporate a system for recording and visualizing sample approximation error information for confidence and importance highlighting.

  5. Challenges and solutions for the analysis of in situ, in crystallo micro-spectrophotometric data

    SciTech Connect

    Dworkowski, Florian S. N.; Hough, Michael A.; Pompidor, Guillaume

    2015-01-01

    The particular challenge of the analysis of optical absorption and Raman spectroscopic data measured from protein crystals and how the SLS-APE software toolbox supports scientists in dealing with such data is described. Combining macromolecular crystallography with in crys