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Sample records for evolved gas analysis

  1. Regolith Evolved Gas Analyzer

    Science.gov (United States)

    Hoffman, John H.; Hedgecock, Jud; Nienaber, Terry; Cooper, Bonnie; Allen, Carlton; Ming, Doug

    2000-01-01

    The Regolith Evolved Gas Analyzer (REGA) is a high-temperature furnace and mass spectrometer instrument for determining the mineralogical composition and reactivity of soil samples. REGA provides key mineralogical and reactivity data that is needed to understand the soil chemistry of an asteroid, which then aids in determining in-situ which materials should be selected for return to earth. REGA is capable of conducting a number of direct soil measurements that are unique to this instrument. These experimental measurements include: (1) Mass spectrum analysis of evolved gases from soil samples as they are heated from ambient temperature to 900 C; and (2) Identification of liberated chemicals, e.g., water, oxygen, sulfur, chlorine, and fluorine. REGA would be placed on the surface of a near earth asteroid. It is an autonomous instrument that is controlled from earth but does the analysis of regolith materials automatically. The REGA instrument consists of four primary components: (1) a flight-proven mass spectrometer, (2) a high-temperature furnace, (3) a soil handling system, and (4) a microcontroller. An external arm containing a scoop or drill gathers regolith samples. A sample is placed in the inlet orifice where the finest-grained particles are sifted into a metering volume and subsequently moved into a crucible. A movable arm then places the crucible in the furnace. The furnace is closed, thereby sealing the inner volume to collect the evolved gases for analysis. Owing to the very low g forces on an asteroid compared to Mars or the moon, the sample must be moved from inlet to crucible by mechanical means rather than by gravity. As the soil sample is heated through a programmed pattern, the gases evolved at each temperature are passed through a transfer tube to the mass spectrometer for analysis and identification. Return data from the instrument will lead to new insights and discoveries including: (1) Identification of the molecular masses of all of the gases

  2. Possible Detection of Perchlorates by Evolved Gas Analysis of Rocknest Soils: Global Implication

    Science.gov (United States)

    Archer, P. D., Jr.; Sutter, B.; Ming, D. W.; McKay, C. P.; Navarro-Gonzalez, R.; Franz, H. B.; McAdam, A.; Mahaffy, P. R.

    2013-01-01

    The Sample Analysis at Mars (SAM) instrument suite on board the Mars Science Laboratory (MSL) recently ran four samples from an aeolian bedform named Rocknest. Rocknest was selected as the source of the first samples analyzed because it is representative of both windblown material in Gale crater as well as the globally-distributed dust. The four samples analyzed by SAM were portioned from the fifth scoop at this location. The material delivered to SAM passed through a 150 m sieve and should have been well mixed during the sample acquisition/ preparation/handoff process. Rocknest samples were heated to 835 C at a 35 C/minute ramp rate with a He carrier gas flow rate of 1.5 standard cubic centimeters per minute and at an oven pressure of 30 mbar. Evolved gases were detected by a quadrupole mass spectrometer (QMS).

  3. Application of evolved gas analysis to cold-cap reactions of melter feeds for nuclear waste vitrification

    Energy Technology Data Exchange (ETDEWEB)

    Kruger, Albert A.; Chun, Jaehun; Hrma, Pavel R.; Rodriguez, Carmen P.; Schweiger, Michael J.

    2014-04-30

    In the vitrification of nuclear wastes, the melter feed (a mixture of nuclear waste and glass-forming and modifying additives) experiences multiple gas-evolving reactions in an electrical glass-melting furnace. We employed the thermogravimetry-gas chromatography-mass spectrometry (TGA-GC-MS) combination to perform evolved gas analysis (EGA). Apart from identifying the gases evolved, we performed quantitative analysis relating the weighed sum of intensities of individual gases linearly proportional with the differential themogravimetry. The proportionality coefficients were obtained by three methods based on the stoichiometry, least squares, and calibration. The linearity was shown to be a good first-order approximation, in spite of the complicated overlapping reactions.

  4. Evolved gas analysis with skimmer interface and ion attachment mass spectrometry for burnout monitoring of organic additives in ceramic processing.

    Science.gov (United States)

    Tsugoshi, Takahisa; Ito, Nanaka; Nagaoka, Takaaki; Watari, Koji

    2006-08-15

    A monitoring of the individual pyrolysis of mixed polymer as a binder for ceramic processing was carried out as an application of evolved gas analysis-mass spectrometry (EGA-MS) with a skimmer interface and ion attachment mass spectrometry (IAMS). It could detect characteristic species evolved by the pyrolysis of the organic additives, according to the instrumental advantages as the transmission of the gaseous species with no transformation by the skimmer interface and complete soft ionization for gaseous species by IAMS technique. Further, the pyrolysis behavior of blended polymers as a binder could be monitored individually as EGA curves of characteristic species evolved by the pyrolyses.

  5. Non-isothermal pyrolysis of de-oiled microalgal biomass: Kinetics and evolved gas analysis.

    Science.gov (United States)

    Maurya, Rahulkumar; Ghosh, Tonmoy; Saravaia, Hitesh; Paliwal, Chetan; Ghosh, Arup; Mishra, Sandhya

    2016-12-01

    Non-isothermal (β=5, 10, 20, 35°C/min) pyrolysis of de-oiled microalgal biomass (DMB) of Chlorella variabilis was investigated by TGA-MS (30-900°C, Argon atmosphere) to understand thermal decomposition and evolved gas analysis (EGA). The results showed that three-stage thermal decomposition and three volatilization zone (100-400°C, 400-550°C and 600-750°C) of organic matters during pyrolysis. The highest rate of weight-loss is 8.91%/min at 302°C for 35°C/min heating-rate. Kinetics of pyrolysis were investigated by iso-conversional (KAS, FWO) and model-fitting (Coats-Redfern) method. For Zone-1and3, similar activation energy (Ea) is found in between KAS (α=0.4), FWO (α=0.4) and Avrami-Erofe'ev (n=4) model. Using the best-fitted kinetic model Avrami-Erofe'ev (n=4), Ea values (R(2)=>0.96) are 171.12 (Zone-1), 404.65 (Zone-2) and 691.42kJ/mol (Zone-3). EGA indicate the abundance of most gases observed consequently between 200-300°C and 400-500°C. The pyrolysis of DMB involved multi-step reaction mechanisms for solid-state reactions having different Ea values. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Sulphur-bearing Compounds Detected by MSL SAM Evolved Gas Analysis of Materials from Yellowknife Bay, Gale Crater, Mars

    Science.gov (United States)

    McAdam, A. C.; Franz, H. B.; Archer, P. D. Jr.; Sutter, B.; Eigenbrode, J. L.; Freissinet, C.; Atreya, S. K.; Bish, D. L.; Blake, D. F.; Brunner, A.; hide

    2014-01-01

    The Sample Analysis at Mars (SAM) and Chemistry and Mineralogy (CheMin) instruments on the Mars Science Laboratory (MSL) analysed several subsamples of sample fines (<150 µm) from three sites in Yellowknife Bay, an aeolian bedform termed Rocknest (hereafter "RN") and two samples drilled from the Sheepbed mudstone at sites named John Klein ("JK") and Cumberland ("CB"). SAM's evolved gas analysis (EGA) mass spectrometry detected H2O, CO2, O2, H2, SO2, H2S, HCl, NO, OCS, CS2 and other trace gases. The identity of evolved gases and temperature (T) of evolution can support mineral detection by CheMin and place constraints on trace volatile-bearing phases present below the CheMin detection limit or difficult to characterize with XRD (e.g., X-ray amorphous phases). Here, we focus on potential constraints on phases that evolved SO2, H2S, OCS, and CS2 during thermal analysis.

  7. Mars Phoenix Scout Thermal Evolved Gas Analyzer (TEGA) Database: Thermal Database Development and Analysis

    Science.gov (United States)

    Sutter, B.; Archer, D.; Niles, P. B.; Stein, T. C.; Hamara, D.; Boynton, W. V.; Ming, D. W.

    2017-01-01

    The Mars Phoenix Scout Lander mission in 2008 examined the history of water, searched for organics, and evaluated the potential for past/present microbial habitability in a martian arctic ice-rich soil [1]. The Thermal Evolved Gas Analyzer (TEGA) instrument measured the isotopic composition of atmospheric CO2 and detected volatile bearing mineralogy (perchlorate, carbonate, hydrated mineral phases) in the martian soil [2-7]. The TEGA data are archived at the Planetary Data System (PDS) Geosciences Node but are reported in forms that require further processing to be of use to the non-TEGA expert. The soil and blank TEGA thermal data are reported as duty cycle and must be converted to differential power (mW) to allow for enthalpy calculations of exothermic/endothermic transitions. The exothermic/endothermic temperatures are also used to determine what phases (inorganic/organic) are present in the sample. The objectives of this work are to: 1) Describe how interpretable thermal data can be created from TEGA data sets on the PDS and 2) Provide additional thermal data interpretation of two Phoenix soils (Baby Bear, Wicked Witch) and include interpretations from three unreported soils (Rosy Red 1, 2, and Burning Coals).

  8. Evolved Gas Analyses of the Murray Formation in Gale Crater, Mars: Results of the Curiosity Rover's Sample Analysis at Mars (SAM) Instrument

    Science.gov (United States)

    Sutter, B.; McAdam, A. C.; Rampe, E. B.; Thompson, L. M.; Ming, D. W.; Mahaffy, P. R.; Navarro-Gonzalez, R.; Stern, J. C.; Eigenbrode, J. L.; Archer, P. D.

    2017-01-01

    The Sample Analysis at Mars (SAM) instrument aboard the Mars Science Laboratory rover has analyzed 13 samples from Gale Crater. All SAM-evolved gas analyses have yielded a multitude of volatiles (e.g., H2O, SO2, H2S, CO2, CO, NO, O2, HCl) [1- 6]. The objectives of this work are to 1) Characterize recent evolved SO2, CO2, O2, and NO gas traces of the Murray formation mudstone, 2) Constrain sediment mineralogy/composition based on SAM evolved gas analysis (SAM-EGA), and 3) Discuss the implications of these results relative to understanding the geological history of Gale Crater.

  9. Evolved Gas Analyses of Sedimentary Materials in Gale Crater, Mars: Results of the Curiosity Rover's Sample Analysis at Mars (SAM) Instrument from Yellowknife Bay to the Stimson Formation

    Science.gov (United States)

    Sutter, B.; McAdam, A. C.; Rampe, E. B.; Ming, D. W.; Mahaffy, P. R.; Navarro-Gonzalez, R.; Stern, J. C.; Eigenbrode, J. L.; Archer, P. D.

    2016-01-01

    The Sample Analysis at Mars (SAM) instrument aboard the Mars Science Laboratory rover has analyzed 10 samples from Gale Crater. All SAM evolved gas analyses have yielded a multitude of volatiles (e.g, H2O, SO2, H2S, CO2, CO, NO, O2, HC1). The objectives of this work are to 1) Characterize the evolved H2O, SO2, CO2, and O2 gas traces of sediments analyzed by SAM through sol 1178, 2) Constrain sediment mineralogy/composition based on SAM evolved gas analysis (SAM-EGA), and 3) Discuss the implications of these results releative to understanding the geochemical history of Gale Crater.

  10. TG-FTIR-MS (Evolved Gas Analysis) of bidi tobacco powder during combustion and pyrolysis.

    Science.gov (United States)

    Ahamad, Tansir; Alshehri, Saad M

    2012-01-15

    Bidi smoke, a complex mixture of toxic and carcinogens chemicals causes a large and growing number of premature deaths in South Asian countries especially in India and Bangladesh. The evolved products during the thermal degradation of bidi tobacco powder (BTP) have been measured by using TG-FTIR-MS technique. The results revealed that the main gases and volatile products released during the combustion and pyrolysis of BTP are CO, CO(2), NH(3), HCN, NO, isoprene, formaldehyde, acetaldehyde, acrolein, etc. Still others such as nicotine, phenol, polyaromatic hydrocarbon and some tobacco specific nitrosamines are contained in submicron sized solid particles that are suspended in Bidi smoke. The intensity or the quantity of evolved products is higher during the combustion than pyrolysis of BTP. The evolved chemical data suggest that Bidi smoke is responsible for cancer of the throat, oral cavity, pharynx, larynx, lungs, esophagus, stomach, and liver. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. Sulfur-bearing phases detected by evolved gas analysis of the Rocknest aeolian deposit, Gale Crater, Mars

    Science.gov (United States)

    McAdam, Amy C.; Franz, Heather B.; Sutter, Brad; Archer, Paul D.; Freissinet, Caroline; Eigenbrode, Jennifer L.; Ming, Douglas W.; Atreya, Sushil K.; Bish, David L.; Blake, David F.; Bower, Hannah E.; Brunner, Anna; Buch, Arnaud; Glavin, Daniel P.; Grotzinger, John P.; Mahaffy, Paul R.; McLennan, Scott M.; Morris, Richard V.; Navarro-González, Rafael; Rampe, Elizabeth B.; Squyres, Steven W.; Steele, Andrew; Stern, Jennifer C.; Sumner, Dawn Y.; Wray, James J.

    2014-02-01

    The Sample Analysis at Mars (SAM) instrument suite detected SO2, H2S, OCS, and CS2 from ~450 to 800°C during evolved gas analysis (EGA) of materials from the Rocknest aeolian deposit in Gale Crater, Mars. This was the first detection of evolved sulfur species from a Martian surface sample during in situ EGA. SO2 (~3-22 µmol) is consistent with the thermal decomposition of Fe sulfates or Ca sulfites, or evolution/desorption from sulfur-bearing amorphous phases. Reactions between reduced sulfur phases such as sulfides and evolved O2 or H2O in the SAM oven are another candidate SO2 source. H2S (~41-109 nmol) is consistent with interactions of H2O, H2 and/or HCl with reduced sulfur phases and/or SO2 in the SAM oven. OCS (~1-5 nmol) and CS2 (~0.2-1 nmol) are likely derived from reactions between carbon-bearing compounds and reduced sulfur. Sulfates and sulfites indicate some aqueous interactions, although not necessarily at the Rocknest site; Fe sulfates imply interaction with acid solutions whereas Ca sulfites can form from acidic to near-neutral solutions. Sulfides in the Rocknest materials suggest input from materials originally deposited in a reducing environment or from detrital sulfides from an igneous source. The presence of sulfides also suggests that the materials have not been extensively altered by oxidative aqueous weathering. The possibility of both reduced and oxidized sulfur compounds in the deposit indicates a nonequilibrium assemblage. Understanding the sulfur mineralogy in Rocknest materials, which exhibit chemical similarities to basaltic fines analyzed elsewhere on Mars, can provide insight in to the origin and alteration history of Martian surface materials.

  12. Sulfur-Bearing Phases Detected by Evolved Gas Analysis of the Rocknest Aeolian Deposit, Gale Crater, Mars

    Science.gov (United States)

    Mcadam, Amy Catherine; Franz, Heather Bryant

    2014-01-01

    The Sample Analysis at Mars (SAM) instrument suite detected SO2, H2S, OCS, and CS2 from approx.450 to 800 C during evolved gas analysis (EGA) of materials from the Rocknest aeolian deposit in Gale Crater, Mars. This was the first detection of evolved sulfur species from a Martian surface sample during in situ EGA. SO2(approx. 3-22 micro-mol) is consistent with the thermal decomposition of Fe sulfates or Ca sulfites, or evolution/desorption from sulfur-bearing amorphous phases. Reactions between reduced sulfur phases such as sulfides and evolved O2 or H2O in the SAM oven are another candidate SO2 source. H2S (approx.41-109 nmol) is consistent with interactions of H2O, H2 and/or HCl with reduced sulfur phases and/or SO2 in the SAM oven. OCS (approx.1-5 nmol) and CS2(approx.0.2-1 nmol) are likely derived from reactions between carbon-bearing compounds and reduced sulfur. Sulfates and sulfites indicate some aqueous interactions, although not necessarily at the Rocknest site; Fe sulfates imply interaction with acid solutions whereas Ca sulfites can form from acidic to near-neutral solutions. Sulfides in the Rocknest materials suggest input from materials originally deposited in a reducing environment or from detrital sulfides from an igneous source. The presence of sulfides also suggests that the materials have not been extensively altered by oxidative aqueous weathering. The possibility of both reduced and oxidized sulfur compounds in the deposit indicates a nonequilibrium assemblage. Understanding the sulfur mineralogy in Rocknest materials, which exhibit chemical similarities to basaltic fines analyzed elsewhere on Mars, can provide insight in to the origin and alteration history of Martian surface materials.

  13. Thermal and Evolved Gas Analysis of Magnesium Perchlorate: Implications for Perchlorates in Soils at the Mars Phoenix Landing Site

    Science.gov (United States)

    Ming, Douglas W.; Morris, R.V.; Lauer, H. V.; Sutter, B.; Golden, D.C.; Boynton, W.V.

    2009-01-01

    Perchlorate salts were discovered in the soils around the Phoenix landing site on the northern plains of Mars [1]. Perchlorate was detected by an ion selective electrode that is part of the MECA Wet Chemistry Laboratory (WCL). The discovery of a mass 32 fragment (likely 02) by the Thermal and Evolved-Gas Analyzer (TEGA) provided additional confirmation of a strong oxidizer in the soils around the landing site. The purpose of this paper is to evaluate the thermal and evolved gas behavior of perchlorate salts using TEGA-like laboratory testbed instruments. TEGA ovens were fabricated from high purity Ni. Hence, an additional objective of this paper is to determine the effects that Ni might have on the evolved gas behavior of perchlorate salts.

  14. Analysis and quantitation of volatile organic compounds emitted from plastics used in museum construction by evolved gas analysis-gas chromatography-mass spectrometry.

    Science.gov (United States)

    Samide, Michael J; Smith, Gregory D

    2015-12-24

    Construction materials used in museums for the display, storage, and transportation of artwork must be assessed for their tendency to emit harmful pollution that could potentially damage cultural treasures. Traditionally, a subjective metals corrosion test known as the Oddy test has been widely utilized in museums for this purpose. To augment the Oddy test, an instrumental sampling approach based on evolved gas analysis (EGA) coupled to gas chromatography (GC) with mass spectral (MS) detection has been implemented for the first time to qualitatively identify off-gassed pollutants under specific conditions. This approach is compared to other instrumental methods reported in the literature. This novel application of the EGA sampling technique yields several benefits over traditional testing, including rapidity, high sensitivity, and broad detectability of volatile organic compounds (VOCs). Furthermore, unlike other reported instrumental approaches, the EGA method was used to determine quantitatively the amount of VOCs emitted by acetate resins and polyurethane foams under specific conditions using both an external calibration method as well as surrogate response factors. EGA was successfully employed to rapidly characterize emissions from 12 types of common plastics. This analysis is advocated as a rapid pre-screening method to rule out poorly performing materials prior to investing time and energy in Oddy testing. The approach is also useful for rapid, routine testing of construction materials previously vetted by traditional testing, but which may experience detrimental formulation changes over time. As an example, a case study on batch re-orders of rigid expanded poly(vinyl chloride) board stock is presented. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. EVOLVED GAS ANALYSIS (COUPLED TG-DSC-FT-IR APPLIED IN THE STUDY OF FRUCTOOLIGOSACCHARIDES FROM CHICORY

    Directory of Open Access Journals (Sweden)

    Roberta de Souza Leone

    2014-08-01

    Full Text Available EGA (Evolved Gas Analysis is a group of coupled techniques (in this case TG-DSC and FT-IR that was used to provide information about the thermal and calorimetric behavior of standard fructooligosaccharides (FOS from chicory. These FOS are found in several foods (tuber, roots, fruits, leaves, cereals, etc. and have been the subject of several studies. In the present study thermogravimetry (TG allowed the characterization of FOS a standard (Sigma-Aldrich, in which the weight loss can be observed in three stages (m 7.56, 55.53 and 36.53%, respectively. The simultaneous use of DSC showed endo and exothermic events in temperature characteristics and in agreement with TG curves. The enthalpies of the main stages of decomposition were calculated: ΔHdehydr 260 J g-1 and ΔHdec 410 J g-1. From the FT-IR spectrum of the volatiles was possible to characterize the main bands, which confirmed CO and CO2 as a result of thermal decomposition.

  16. Thermal and Evolved-Gas Analyzer Illustration

    Science.gov (United States)

    2008-01-01

    This is a computer-aided drawing of the Thermal and Evolved-Gas Analyzer, or TEGA, on NASA's Phoenix Mars Lander. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  17. Thermogravimetry-evolved gas analysis–mass spectrometry system ...

    Indian Academy of Sciences (India)

    This system which gives complete information on weight change, heat change, nature and content of evolved gases is being used for. temperature programmed decomposition (TPD),; synthesis of nanocrystalline materials,; gas–solid interactions and; analysis of gas mixtures. The TPD of various inorganic oxyanion solids ...

  18. Kinetics and evolved gas analysis for pyrolysis of food processing wastes using TGA/MS/FT-IR.

    Science.gov (United States)

    Özsin, Gamzenur; Pütün, Ayşe Eren

    2017-06-01

    The objective of this study was to identify the pyrolysis of different bio-waste produced by food processing industry in a comprehensible manner. For this purpose, pyrolysis behaviors of chestnut shells (CNS), cherry stones (CS) and grape seeds (GS) were investigated by thermogravimetric analysis (TGA) combined with a Fourier-transform infrared (FT-IR) spectrometer and a mass spectrometer (MS). In order to make available theoretical groundwork for biomass pyrolysis, activation energies were calculated with the help of four different model-free kinetic methods. The results are attributed to the complex reaction schemes which imply parallel, competitive and complex reactions during pyrolysis. During pyrolysis, the evolution of volatiles was also characterized by FT-IR and MS. The main evolved gases were determined as H2O, CO2 and hydrocarbons such as CH4 and temperature dependent profiles of the species were obtained. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Thermally evolved gas analysis (TEGA) of hyperarid soils doped with microorganisms from the Atacama Desert in southern Peru: Implications for the Phoenix mission

    Science.gov (United States)

    Valdivia-Silva, Julio E.; Navarro-González, Rafael; McKay, Christopher

    2009-07-01

    TEGA, one of several instruments on board of the Phoenix Lander, performed differential scanning calorimetry and evolved gas analysis of soil samples and ice, collected from the surface and subsurface at a northern landing site on Mars. TEGA is a combination of a high temperature furnace and a mass spectrometer (MS) that was used to analyze samples delivered to the instrument via a robotic arm. The samples were heated at a programmed ramp rate up to 1000 °C. The power required for heating can be carefully and continuously monitored (scanning calorimetry). The evolved gases generated during the process can be analyzed with the evolved gas analyzer (a magnetic sector mass spectrometer) in order to determine the composition of gases released as a function of temperature. Our laboratory has developed a sample characterization method using a pyrolyzer integrated to a quadrupole mass spectrometer to support the interpretations of TEGA data. Here we examine the evolved gas properties of six types of hyperarid soils from the Pampas de La Joya in southern Peru (a possible analog to Mars), to which we have added with microorganisms ( Salmonella typhimurium, Micrococcus luteus, and Candida albicans) in order to investigate the effect of the soil matrix on the TEGA response. Between 20 and 40 mg of soil, with or without ˜5 mg of lyophilized microorganism biomass (dry weight), were placed in the pyrolyzer and heated from room temperature to 1200 °C in 1 h at a heating rate of 20 °C/min. The volatiles released were transferred to a MS using helium as a carrier gas. The quadrupole MS was ran in scan mode from 10 to 200 m/z. In addition, ˜20 mg of each microorganism without a soil matrix were analyzed. As expected, there were significant differences in the gases released from microorganism samples with or without a soil matrix, under similar heating conditions. Furthermore, samples from the most arid environments had significant differences compared with less arid soils

  20. Kinetics of Cold-Cap Reactions for Vitrification of Nuclear Waste Glass Based on Simultaneous Differential Scanning Calorimetry - Thermogravimetry (DSC-TGA) and Evolved Gas Analysis (EGA)

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, Carmen P.; Pierce, David A.; Schweiger, Michael J.; Kruger, Albert A.; Chun, Jaehun; Hrma, Pavel R.

    2013-12-03

    For vitrifying nuclear waste glass, the feed, a mixture of waste with glass-forming and modifying additives, is charged onto the cold cap that covers 90-100% of the melt surface. The cold cap consists of a layer of reacting molten glass floating on the surface of the melt in an all-electric, continuous glass melter. As the feed moves through the cold cap, it undergoes chemical reactions and phase transitions through which it is converted to molten glass that moves from the cold cap into the melt pool. The process involves a series of reactions that generate multiple gases and subsequent mass loss and foaming significantly influence the mass and heat transfers. The rate of glass melting, which is greatly influenced by mass and heat transfers, affects the vitrification process and the efficiency of the immobilization of nuclear waste. We studied the cold-cap reactions of a representative waste glass feed using both the simultaneous differential scanning calorimetry thermogravimetry (DSC-TGA) and the thermogravimetry coupled with gas chromatography-mass spectrometer (TGA-GC-MS) as complementary tools to perform evolved gas analysis (EGA). Analyses from DSC-TGA and EGA on the cold-cap reactions provide a key element for the development of an advanced cold-cap model. It also helps to formulate melter feeds for higher production rate.

  1. Field Characterization of the Mineralogy and Organic Chemistry of Carbonates from the 2010 Arctic Mars Analog Svalbard Expedition by Evolved Gas Analysis

    Science.gov (United States)

    McAdam, A. C.; Ten Kate, I. L.; Stern, J. C.; Mahaffy, P. R.; Blake, D. F.; Morris, R. V.; Steele, A.; Amundson, H. E. F.

    2011-01-01

    The 2010 Arctic Mars Analog Svalbard Expedition (AMASE) investigated two geologic settings using methodologies and techniques being developed or considered for future Mars missions, such as the Mars Science Laboratory (MSL), ExoMars, and Mars Sample Return. The Sample Analysis at Mars (SAM) [1] instrument suite, which will be on MSL, consists of a quadrupole mass spectrometer (QMS), a gas chromatograph (GC), and a tunable laser mass spectrometer (TLS); all will be applied to analyze gases created by pyrolysis of samples. During AMASE, a Hiden Evolved Gas Analysis-Mass Spectrometer (EGA-MS) system represented the EGA-MS capability of SAM. Another MSL instrument, CheMin, will use x-ray diffraction (XRD) and x-ray fluorescence (XRF) to perform quantitative mineralogical characterization of samples [e.g., 2]. Field-portable versions of CheMin were used during AMASE. AMASE 2010 focused on two sites that represented biotic and abiotic analogs. The abiotic site was the basaltic Sigurdfjell vent complex, which contains Mars-analog carbonate cements including carbonate globules which are excellent analogs for the globules in the ALH84001 martian meteorite [e.g., 3, 4]. The biotic site was the Knorringfjell fossil methane seep, which featured carbonates precipitated in a methane-supported chemosynthetic community [5]. This contribution focuses on EGA-MS analyses of samples from each site, with mineralogy comparisons to CheMin team results. The results give insight into organic content and organic-mineral associations, as well as some constraints on the minerals present.

  2. Evolved gas analyses of sedimentary rocks and eolian sediment in Gale Crater, Mars: Results of the Curiosity rover's sample analysis at Mars instrument from Yellowknife Bay to the Namib Dune

    Science.gov (United States)

    Sutter, B.; McAdam, A. C.; Mahaffy, P. R.; Ming, D. W.; Edgett, K. S.; Rampe, E. B.; Eigenbrode, J. L.; Franz, H. B.; Freissinet, C.; Grotzinger, J. P.; Steele, A.; House, C. H.; Archer, P. D.; Malespin, C. A.; Navarro-González, R.; Stern, J. C.; Bell, J. F.; Calef, F. J.; Gellert, R.; Glavin, D. P.; Thompson, L. M.; Yen, A. S.

    2017-12-01

    The sample analysis at Mars instrument evolved gas analyzer (SAM-EGA) has detected evolved water, H2, SO2, H2S, NO, CO2, CO, O2, and HCl from two eolian sediments and nine sedimentary rocks from Gale Crater, Mars. These evolved gas detections indicate nitrates, organics, oxychlorine phase, and sulfates are widespread with phyllosilicates and carbonates occurring in select Gale Crater materials. Coevolved CO2 (160 ± 248-2373 ± 820 μgC(CO2)/g) and CO (11 ± 3-320 ± 130 μgC(CO)/g) suggest that organic C is present in Gale Crater materials. Five samples evolved CO2 at temperatures consistent with carbonate (0.32 ± 0.05-0.70 ± 0.1 wt % CO3). Evolved NO amounts to 0.002 ± 0.007-0.06 ± 0.03 wt % NO3. Evolution of O2 suggests that oxychlorine phases (chlorate/perchlorate) (0.05 ± 0.025-1.05 ± 0.44 wt % ClO4) are present, while SO2 evolution indicates the presence of crystalline and/or poorly crystalline Fe and Mg sulfate and possibly sulfide. Evolved H2O (0.9 ± 0.3-2.5 ± 1.6 wt % H2O) is consistent with the presence of adsorbed water, hydrated salts, interlayer/structural water from phyllosilicates, and possible inclusion water in mineral/amorphous phases. Evolved H2 and H2S suggest that reduced phases occur despite the presence of oxidized phases (nitrate, oxychlorine, sulfate, and carbonate). SAM results coupled with CheMin mineralogical and Alpha-Particle X-ray Spectrometer elemental analyses indicate that Gale Crater sedimentary rocks have experienced a complex authigenetic/diagenetic history involving fluids with varying pH, redox, and salt composition. The inferred geochemical conditions were favorable for microbial habitability and if life ever existed, there was likely sufficient organic C to support a small microbial population.

  3. In situ evolved gas analysis assisted thermogravimetric (TG-FTIR and TG/DTA–MS) studies on non-activated copper benzene-1,3,5-tricarboxylate

    Energy Technology Data Exchange (ETDEWEB)

    Domán, Andrea; Madarász, János; László, Krisztina (Budapest)

    2017-01-01

    The results of a complete thermogravimetric study of copper benzene-1,3,5-tricarboxylate (Cu-BTC or HKUST-1) are reported here together with mass spectrometry (MS) and Fourier transform infrared spectroscopy (FTIR) analyses of the evolved gases up to 800 °C. Oxidative and inert conditions were applied to reveal the stoichiometry of the as-received synthesis product. In spite of using a water-ethanol mixture during the synthesis and the filtration, only water is retained in the pores. It is proposed that the thermolytic release of ethanol in the temperature range 150–250 °C originates from ethanol-benzene-1,3,5-tricarboxylate (BTC) esters situated on the surface of the HKUST-1 crystal, and which limit the size of the developing crystals during the synthesis.

  4. EVOLVE

    CERN Document Server

    Deutz, André; Schütze, Oliver; Legrand, Pierrick; Tantar, Emilia; Tantar, Alexandru-Adrian

    2017-01-01

    This book comprises nine selected works on numerical and computational methods for solving multiobjective optimization, game theory, and machine learning problems. It provides extended versions of selected papers from various fields of science such as computer science, mathematics and engineering that were presented at EVOLVE 2013 held in July 2013 at Leiden University in the Netherlands. The internationally peer-reviewed papers include original work on important topics in both theory and applications, such as the role of diversity in optimization, statistical approaches to combinatorial optimization, computational game theory, and cell mapping techniques for numerical landscape exploration. Applications focus on aspects including robustness, handling multiple objectives, and complex search spaces in engineering design and computational biology.

  5. Chlorine Gas: An Evolving Hazardous Material Threat and Unconventional Weapon

    OpenAIRE

    Jones, Robert MD; Wills, Brandon DO; Kang, Christopher MD

    2010-01-01

    Chlorine gas represents a hazardous material threat from industrial accidents and as a terrorist weapon. This review will summarize recent events involving chlorine disasters and its use by terrorists, discuss pre-hospital considerations and suggest strategies for the initial management for acute chlorine exposure events. [West J Emerg Med. 2010; 11(2):151-156.

  6. Chlorine Gas: An Evolving Hazardous Material Threat and Unconventional Weapon

    Directory of Open Access Journals (Sweden)

    Jones, Robert MD

    2010-05-01

    Full Text Available Chlorine gas represents a hazardous material threat from industrial accidents and as a terrorist weapon. This review will summarize recent events involving chlorine disasters and its use by terrorists, discuss pre-hospital considerations and suggest strategies for the initial management for acute chlorine exposure events. [West J Emerg Med. 2010; 11(2:151-156.

  7. Insights into the Sulfur Mineralogy of Martian Soil at Rocknest, Gale Crater, Enabled by Evolved Gas Analyses

    Science.gov (United States)

    McAdam, A.; Franz, H.; Archer, P., Jr.; Freissinet, C.; Sutter, B.; Glavin, D.; Eigenbrode, J.; Bower, H.; Stern, J.; Mchaffy, P.; hide

    2013-01-01

    The first solid samples analysed by the Chemistry and Mineralogy (CheMin) instrument and Sample Analysis at Mars (SAM) instrument suite on the Mars Science Laboratory (MSL) consisted of < 150 m fines sieved from aeolian bedform material at a site named Rocknest. All four samples of this material analyzed by SAM s evolved gas analysis mass spectrometry (EGA-MS) released H2O, CO2, O2, and SO2 (Fig. 1), as well as H2S and possibly NO. This is the first time evolved SO2 (and evolved H2S) has been detected from thermal analysis of martian materials. The identity of these evolved gases and temperature (T) of evolution can support mineral detection by CheMin and place constraints on trace volatile-bearing phases present below the CheMin detection limit or difficult to characterize with XRD (e.g., X-ray amorphous phases). Constraints on phases responsible for evolved CO2 and O2 are detailed elsewhere [1,2,3]. Here, we focus on potential constraints on phases that evolved SO2, H2S, and H2O during thermal analysis.

  8. Impact of the spatial distribution of morphological pattern on the efficiency of electrocatalytic gas evolving reactions

    Directory of Open Access Journals (Sweden)

    Žerađanin Aleksandar R.

    2014-01-01

    Full Text Available The efficiency of electrocatalytic gas evolving reactions (hydrogen, chlorine and oxygen evolution is a key challenge for the important industrial processes, such as chlor-alkali electrolysis or water electrolysis. Central issue for the aforementioned electrocatalytic processes is huge power consumption. Experimental results accumulated in the past, as well as some predictive models ("volcano" plots indicate that altering the nature of the electrode material cannot significantly increase the activity of mentioned reactions. Consequently, it is necessary to find a qualitatively different strategy for improving the energy efficiency of electrocatalytic gas evolving reactions. Usually disregarded fact is that the gas evolution is an oscillatory phenomenon. Given the oscillatory behavior, a key parameter of macrokinetics of gas electrode is the frequency of gas-bubble detachment. Bearing in mind that the gas evolution greatly depends on the surface morphology, a methodology is proposed that establishes a rational link between the morphological pattern of electrode with electrode activity and stability. Characterization was performed using advanced analytical tools. Frequency of gas-bubble detachment is obtained in the configuration of scanning electrochemical microscopy (SECM while the corrosion stability is analyzed using miniaturized scanning flow electrochemical cell connected to the mass spectrometer (SFC-ICPMS.

  9. Qualitative Functional Decomposition Analysis of Evolved Neuromorphic Flight Controllers

    Directory of Open Access Journals (Sweden)

    Sanjay K. Boddhu

    2012-01-01

    Full Text Available In the previous work, it was demonstrated that one can effectively employ CTRNN-EH (a neuromorphic variant of EH method methodology to evolve neuromorphic flight controllers for a flapping wing robot. This paper describes a novel frequency grouping-based analysis technique, developed to qualitatively decompose the evolved controllers into explainable functional control blocks. A summary of the previous work related to evolving flight controllers for two categories of the controller types, called autonomous and nonautonomous controllers, is provided, and the applicability of the newly developed decomposition analysis for both controller categories is demonstrated. Further, the paper concludes with appropriate discussion of ongoing work and implications for possible future work related to employing the CTRNN-EH methodology and the decomposition analysis techniques presented in this paper.

  10. Reduced and Oxidized Sulfur Compounds Detected by Evolved Gas Analyses of Materials from Yellowknife Bay, Gale Crater, Mars

    Science.gov (United States)

    McAdam, A. C.; Franz, H. B.; Archer, P. D., Jr.; Sutter, B.; Eigenbrode, J. L.; Freissinet, C.; Atreya, S. K.; Bish, D. L.; Blake, D. F.; Brunner, A.; hide

    2014-01-01

    Sulfate minerals have been directly detected or strongly inferred from several Mars datasets and indicate that aqueous alteration of martian surface materials has occurred. Indications of reduced sulfur phases (e.g., sulfides) from orbital and in situ investigations of martian materials have been fewer in number, but these phases are observed in martian meteorites and are likely because they are common minor phases in basaltic rocks. Here we discuss potential sources for the S-bearing compounds detected by the Mars Science Laboratory (MSL) Sample Analysis at Mars (SAM) instrument’s evolved gas analysis (EGA) experiments.

  11. Robotic Arm Camera Image of the South Side of the Thermal and Evolved-Gas Analyzer (Door TA4

    Science.gov (United States)

    2008-01-01

    The Thermal and Evolved-Gas Analyzer (TEGA) instrument aboard NASA's Phoenix Mars Lander is shown with one set of oven doors open and dirt from a sample delivery. After the 'seventh shake' of TEGA, a portion of the dirt sample entered the oven via a screen for analysis. This image was taken by the Robotic Arm Camera on Sol 18 (June 13, 2008), or 18th Martian day of the mission. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  12. Deuterium Gas Analysis by Residual Gas Analyzer

    Science.gov (United States)

    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.

  13. Regolith Evolved Gas Analyzer (REGA): An Instrument to Characterize the Martian Soil Mineralogy and Atmosphere Composition

    Science.gov (United States)

    Hoffman, John H.; McKay, David S.; Ming, Douglas; Allen, Carlton C.; Hedgecock, Jud; Nienaber, Terry

    2000-01-01

    This abstract describes an instrument and experiment to be proposed for a future Mars surface mission to conduct basic research on environmental characterization. The Regolith Evolved Gas Analyzer (REGA) experiment is designed to provide information on Mars surface material properties in preparation for human missions of exploration. The goals of the investigation are: 1) Define and determine surface mineralogy of soil and dust and their effects on humans and machines; and 2) Conduct in-situ investigations aimed at identifying possible evidence of past or present life on Mars.

  14. Properties of the molecular gas around the most massive evolved stars

    Science.gov (United States)

    Quintana-Lacaci, G.; Cernicharo, J.; Bujarrabal, V.; Castro-Carrizo, A.; Sanchez-Contreras, C.; Agundez, M.; Alcolea J.

    2014-04-01

    The kinematical and chemical properties of gas ejected by the most massive evolved stars are far from being understood. The observation of molecular rovibrational transitions has been shown to be an extremely powerful tool to study theses characteristics of the gas. In order to study these properties we have obtained a large amount of molecular data. In particular, we have obtained interferometric CO maps of the red supergiant stars (RSGs) Mu Cep and S Per, of the yellow hypergiant stars (YHGs) AFGL2343 and IRC+10420 and of two C-rich stars showing gas with high expansion velocities, AFGL2233 and IRC+10401. In addition we have performed a line surveys of the RSG VY CMa, the YHG IRC+10420 and C-rich stars AFGL2233 and IRC+10401 with the IRAM 30m telescope and the HIFI instrument. These observations revealed the rich chemistry present in these objects. In particular we have confirmed the enrichment in nitrogen predicted for the massive stars by the hot bottom burning (HBB) process. Also, we have found evidences that support that the C-rich stars AFGL2233 and IRC+10401 are massive stars that have deactivated the HBB process. Finally, we will propose an evolutionary scenario for the late massive stars, based in the kinematical study of the CO interferometric maps obtained for the RSGs and the YHGs.

  15. Evolving natural gas markets: LNG possibilities for a hydrothermal power system

    Energy Technology Data Exchange (ETDEWEB)

    Correia, Tiago B.; Resende, Joao P.; Costa, Agnes M. [Brazilian Ministry of Mines and Energy, Brasilia, DF (Brazil)

    2008-07-01

    The latest advancements in the natural gas - NG industry have brought new opportunities for the resource's application, especially in the power industry. On the one hand, rapid growth in demand and falling costs of transportation over long distances, particularly as liquefied natural gas - LNG, should lead to a more integrated NG world market. On the other, the deregulation of electricity markets and the growth of independent power producers - IPPs using NG as a fuel for generating peak load power have increased the demand for more flexible NG supply contracts. These factors have allowed a shift in the timing of investment and contract negotiation in NG market. Traditionally, firms searched for trading partners and signed long-term contracts before investing in infrastructure. In the evolving LNG market, producers invest in infrastructure before they have buyers for all their expected outputs, while buyers undertake investment before having firm contracts for all their expected NG needs. These technological and market changes may foster greater participation of a fully flexible NG power plants in the Brazilian electricity market. Nowadays, thermal power long-term capacity contracts customized and negotiated in the local electricity pool (ACR) require power producer to award guarantees of NG firm supply, substantially increasing their cost. A combination of flexible LNG supply contracts and electricity pool contracts may present a solution to the lack of competitiveness of NG power plants in the Brazilian power industry. (author)

  16. Equation-free analysis of a dynamically evolving multigraph

    Science.gov (United States)

    Holiday, A.; Kevrekidis, I. G.

    2016-09-01

    In order to illustrate the adaptation of traditional continuum numerical techniques to the study of complex network systems, we use the equation-free framework to analyze a dynamically evolving multigraph. This approach is based on coupling short intervals of direct dynamic network simulation with appropriately-defined lifting and restriction operators, mapping the detailed network description to suitable macroscopic (coarse-grained) variables and back. This enables the acceleration of direct simulations through Coarse Projective Integration (CPI), as well as the identification of coarse stationary states via a Newton-GMRES method. We also demonstrate the use of data-mining, both linear (principal component analysis, PCA) and nonlinear (diffusion maps, DMAPS) to determine good macroscopic variables (observables) through which one can coarse-grain the model. These results suggest methods for decreasing simulation times of dynamic real-world systems such as epidemiological network models. Additionally, the data-mining techniques could be applied to a diverse class of problems to search for a succint, low-dimensional description of the system in a small number of variables.

  17. Electrochemistry of single nanobubbles. Estimating the critical size of bubble-forming nuclei for gas-evolving electrode reactions.

    Science.gov (United States)

    German, Sean R; Edwards, Martin A; Chen, Qianjin; Liu, Yuwen; Luo, Long; White, Henry S

    2016-12-12

    In this article, we address the fundamental question: "What is the critical size of a single cluster of gas molecules that grows and becomes a stable (or continuously growing) gas bubble during gas evolving reactions?" Electrochemical reactions that produce dissolved gas molecules are ubiquitous in electrochemical technologies, e.g., water electrolysis, photoelectrochemistry, chlorine production, corrosion, and often lead to the formation of gaseous bubbles. Herein, we demonstrate that electrochemical measurements of the dissolved gas concentration, at the instant prior to nucleation of an individual nanobubble of H2, N2, or O2 at a Pt nanodisk electrode, can be analyzed using classical thermodynamic relationships (Henry's law and the Young-Laplace equation - including non-ideal corrections) to provide an estimate of the size of the gas bubble nucleus that grows into a stable bubble. We further demonstrate that this critical nucleus size is independent of the radius of the Pt nanodisk employed (pressure of ∼350 atm, and contains ∼1700 H2 molecules. The data are consistent with stochastic fluctuations in the density of dissolved gas, at or near the Pt/solution interface, controlling the rate of bubble nucleation. We discuss the growth of the nucleus as a diffusion-limited process and how that process is affected by proximity to an electrode producing ∼1011 gas molecules per second. Our study demonstrates the advantages of studying a single-entity, i.e., an individual nanobubble, in understanding and quantifying complex physicochemical phenomena.

  18. Metadata Evaluation and Improvement: Evolving Analysis and Reporting

    Science.gov (United States)

    Habermann, Ted; Kozimor, John; Gordon, Sean

    2017-01-01

    ESIP Community members create and manage a large collection of environmental datasets that span multiple decades, the entire globe, and many parts of the solar system. Metadata are critical for discovering, accessing, using and understanding these data effectively and ESIP community members have successfully created large collections of metadata describing these data. As part of the White House Big Earth Data Initiative (BEDI), ESDIS has developed a suite of tools for evaluating these metadata in native dialects with respect to recommendations from many organizations. We will describe those tools and demonstrate evolving techniques for sharing results with data providers.

  19. Water resources and shale gas/oil production in the Appalachian Basin: critical issues and evolving developments

    Science.gov (United States)

    Kappel, William M.; Williams, John H.; Szabo, Zoltan

    2013-01-01

    Unconventional natural gas and oil resources in the United States are important components of a national energy program. While the Nation seeks greater energy independence and greener sources of energy, Federal agencies with environmental responsibilities, state and local regulators and water-resource agencies, and citizens throughout areas of unconventional shale gas development have concerns about the environmental effects of high volume hydraulic fracturing (HVHF), including those in the Appalachian Basin in the northeastern United States (fig. 1). Environmental concerns posing critical challenges include the availability and use of surface water and groundwater for hydraulic fracturing; the migration of stray gas and potential effects on overlying aquifers; the potential for flowback, formation fluids, and other wastes to contaminate surface water and groundwater; and the effects from drill pads, roads, and pipeline infrastructure on land disturbance in small watersheds and headwater streams (U.S. Government Printing Office, 2012). Federal, state, regional and local agencies, along with the gas industry, are striving to use the best science and technology to develop these unconventional resources in an environmentally safe manner. Some of these concerns were addressed in U.S. Geological Survey (USGS) Fact Sheet 2009–3032 (Soeder and Kappel, 2009) about potential critical effects on water resources associated with the development of gas extraction from the Marcellus Shale of the Hamilton Group (Ver Straeten and others, 1994). Since that time, (1) the extraction process has evolved, (2) environmental awareness related to high-volume hydraulic fracturing process has increased, (3) state regulations concerning gas well drilling have been modified, and (4) the practices used by industry to obtain, transport, recover, treat, recycle, and ultimately dispose of the spent fluids and solid waste materials have evolved. This report updates and expands on Fact Sheet 2009

  20. Analysis of the evolved contact system V367 Cygni

    Energy Technology Data Exchange (ETDEWEB)

    Li, Y.F.; Leung, K.C.

    1987-02-01

    Three groups of observations of V367 Cyg - Fresa's blue light curve (1957-1960, group I), Heiser's UBV light curves (1960-1961, group II), and BV light curves of Kalv and Pustylnik (1967-1973, group III) - were analyzed separately with the Wilson and Devinney approach. An appropriate value of the mass ratio of the system was derived from a q-search procedure. Three contact solutions were obtained with over-contact of 0.0 percent (critical contact), 4.5 percent, and 8.8 percent, corresponding to the observations of group I, group II, and group III respectively; and no third lights were found in the light curves. Absolute dimensions of the system were calculated with the photometric mass ratio. The observed radii are found to be about a factor of six greater than the zero-age main-sequence values for stars of corresponding masses. It is suggested that V367 Cyg is at an evolved contact phase with active mass transfer or mass loss or both. 19 references.

  1. Analysis of the evolved contact system V367 Cygni

    Science.gov (United States)

    Li, Yan-Feng; Leung, Kam-Ching

    1987-02-01

    Three groups of observations of V367 Cyg - Fresa's blue light curve (1957-1960, group I), Heiser's UBV light curves (1960-1961, group II), and BV light curves of Kalv and Pustylnik (1967-1973, group III) - were analyzed separately with the Wilson and Devinney approach. An appropriate value of the mass ratio of the system was derived from a q-search procedure. Three contact solutions were obtained with over-contact of 0.0 percent (critical contact), 4.5 percent, and 8.8 percent, corresponding to the observations of group I, group II, and group III respectively; and no third lights were found in the light curves. Absolute dimensions of the system were calculated with the photometric mass ratio. The observed radii are found to be about a factor of six greater than the zero-age main-sequence values for stars of corresponding masses. It is suggested that V367 Cyg is at an evolved contact phase with active mass transfer or mass loss or both.

  2. Evolving cosmic scenario in modified Chaplygin gas with adiabatic matter creation

    Science.gov (United States)

    Bhattacharya, Subhra; Halder, Shibaji; Chakraborty, Subenoy

    2018-01-01

    Modified Chaplygin Gas has been successful in describing the cosmic history of the universe from radiation to ΛCDM in standard cosmology, while particle creation mechanism in nonlinear thermodynamics can be used to explain inflation as well as late time acceleration. The present work is an attempt to explore the possibilities of obtaining an alternative explanation to cosmic evolution when modified Chaplygin gas is used in the context of particle creation mechanism.

  3. Umbilical cord blood gas analysis.

    Science.gov (United States)

    Thorp, J A; Rushing, R S

    1999-12-01

    Umbilical cord blood gas and pH values should always be obtained in the high-risk delivery and whenever newborn depression occurs. This practice is important because umbilical cord blood gas analysis may assist with clinical management and excludes the diagnosis of birth asphyxia in approximately 80% of depressed newborns at term. The most useful umbilical cord blood parameter is arterial pH. Sampling umbilical venous blood alone is not recommended because arterial blood is more representative of the fetal metabolic condition and because arterial acidemia may occur with a normal venous pH. A complete blood gas analysis may provide important information regarding the type and cause of acidemia and sampling the artery and vein may provide a more clear assessment. The sampling technique is simple and easily mastered by any treatment person in the delivery room. Preheparinized syringes ensure a consistent dose and amount of heparin. Depending on how normality is defined and on the population studied, normal ranges for umbilical cord blood gas values vary (see Table 1). In general, the lower range for normal arterial pH extends to at least 7.10 and that for venous pH to at least 7.20. Many different factors during pregnancy, labor, and delivery can affect cord blood gases. Umbilical blood sampling for acid-base status at all deliveries cannot be universally recommended because many facilities do not have the capabilities to support such a practice and in doing so may impose an excessive financial burden. Considering the costs, the accumulated published data, and the nonspecificity of electronic fetal monitoring in the evaluation of fetal oxygenation, it may be more rational to implement universal cord blood gas analysis. Care providers and institutions with the logistical capabilities in place should consider the cost efficacy of routine cord blood gas analysis because it is the gold standard assessment of uteroplacental function and fetal oxygenation/acid-base status

  4. SAM-Like Evolved Gas Analyses of Phyllosilicate Minerals and Applications to SAM Analyses of the Sheepbed Mudstone, Gale Crater, Mars

    Science.gov (United States)

    McAdam, A. C.; Franz, H. B.; Mahaffy, P. R.; Eigenbrode, J. L.; Stern, J. C.; Brunner, B.; Sutter, B.; Archer, P. D.; Ming , D. W.; Morris, R. V.; hide

    2014-01-01

    While in Yellowknife Bay, the Mars Science Laboratory Curiosity rover collected two drilled samples, John Klein (hereafter "JK") and Cumberland ("CB"), from the Sheepbed mudstone, as well as a scooped sample from the Rocknest aeolian bedform ("RN"). These samples were sieved by Curiosity's sample processing system and then several subsamples of these materials were delivered to the Sample Analysis at Mars (SAM) instrument suite and the CheMin X-ray diffraction/X-ray fluorescence instrument. CheMin provided the first in situ X-ray diffraction-based evidence of clay minerals on Mars, which are likely trioctahedral smectites (e.g., Fe-saponite) and comprise 20 wt% of the mudstone samples [1]. SAM's evolved gas analysis (EGA) mass spectrometry analyses of JK and CB subsamples, as well as RN subsamples, detected H2O, CO2, O2, H2, SO2, H2S, HCl, NO, OCS, CS2 and other trace gases evolved during pyrolysis. The identity of evolved gases and temperature( s) of evolution can augment mineral detection by CheMin and place constraints on trace volatile-bearing phases present below the CheMin detection limit or those phases difficult to characterize with XRD (e.g., X-ray amorphous phases). Here we will focus on the SAM H2O data, in the context of CheMin analyses, and comparisons to laboratory SAM-like analyses of several phyllosilicate minerals including smectites.

  5. DGA Clustering and Analysis: Mastering Modern, Evolving Threats, DGALab

    Directory of Open Access Journals (Sweden)

    Alexander Chailytko

    2016-05-01

    Full Text Available Domain Generation Algorithms (DGA is a basic building block used in almost all modern malware. Malware researchers have attempted to tackle the DGA problem with various tools and techniques, with varying degrees of success. We present a complex solution to populate DGA feed using reversed DGAs, third-party feeds, and a smart DGA extraction and clustering based on emulation of a large number of samples. Smart DGA extraction requires no reverse engineering and works regardless of the DGA type or initialization vector, while enabling a cluster-based analysis. Our method also automatically allows analysis of the whole malware family, specific campaign, etc. We present our system and demonstrate its abilities on more than 20 malware families. This includes showing connections between different campaigns, as well as comparing results. Most importantly, we discuss how to utilize the outcome of the analysis to create smarter protections against similar malware.

  6. Exploring Twitter communication dynamics with evolving community analysis

    Directory of Open Access Journals (Sweden)

    Konstantinos Konstantinidis

    2017-02-01

    Full Text Available Online Social Networks (OSNs have been widely adopted as a means of news dissemination, event reporting, opinion expression and discussion. As a result, news and events are being constantly reported and discussed online through OSNs such as Twitter. However, the variety and scale of all the information renders manual analysis extremely cumbersome, and therefore creating a storyline for an event or news story is an effort-intensive task. The main challenge pertains to the magnitude of data to be analyzed. To this end, we propose a framework for ranking the resulting communities and their metadata on the basis of structural, contextual and evolutionary characteristics such as community centrality, textual entropy, persistence and stability. We apply the proposed framework on three Twitter datasets and demonstrate that the analysis that followed enables the extraction of new insights with respect to influential user accounts, topics of discussion and emerging trends. These insights could primarily assist the work of social and political analysis scientists and the work of journalists in their own story telling, but also highlight the limitations of existing analysis methods and pose new research questions. To our knowledge, this study is the first to investigate the ranking of dynamic communities. In addition, our findings suggest future work regarding the determination of the general context of the communities based on structure and evolutionary behavior alone.

  7. Evolving shale gas management: water resource risks, impacts, and lessons learned.

    Science.gov (United States)

    Rahm, Brian G; Riha, Susan J

    2014-05-01

    Unconventional shale gas development promises to significantly alter energy portfolios and economies around the world. It also poses a variety of environmental risks, particularly with respect to the management of water resources. We review current scientific understanding of risks associated with the following: water withdrawals for hydraulic fracturing; wastewater treatment, discharge and disposal; methane and fluid migration in the subsurface; and spills and erosion at the surface. Some of these risks are relatively unique to shale gas development, while others are variations of risks that we already face from a variety of industries and activities. All of these risks depend largely on the pace and scale of development that occurs within a particular region. We focus on the United States, where the shale gas boom has been on-going for several years, paying particular attention to the Marcellus Shale, where a majority of peer-reviewed study has taken place. Governments, regulatory agencies, industry, and other stakeholders are challenged with responding to these risks, and we discuss policies and practices that have been adopted or considered by these various groups. Adaptive Management, a structured framework for addressing complex environmental issues, is discussed as a way to reduce polarization of important discussions on risk, and to more formally engage science in policy-making, along with other economic, social and value considerations. Data suggests that some risks can be substantially reduced through policy and best practice, but also that significant uncertainty persists regarding other risks. We suggest that monitoring and data collection related to water resource risks be established as part of planning for shale gas development before activity begins, and that resources are allocated to provide for appropriate oversight at various levels of governance.

  8. Life-cycle analysis of shale gas and natural gas.

    Energy Technology Data Exchange (ETDEWEB)

    Clark, C.E.; Han, J.; Burnham, A.; Dunn, J.B.; Wang, M. (Energy Systems); ( EVS)

    2012-01-27

    The technologies and practices that have enabled the recent boom in shale gas production have also brought attention to the environmental impacts of its use. Using the current state of knowledge of the recovery, processing, and distribution of shale gas and conventional natural gas, we have estimated up-to-date, life-cycle greenhouse gas emissions. In addition, we have developed distribution functions for key parameters in each pathway to examine uncertainty and identify data gaps - such as methane emissions from shale gas well completions and conventional natural gas liquid unloadings - that need to be addressed further. Our base case results show that shale gas life-cycle emissions are 6% lower than those of conventional natural gas. However, the range in values for shale and conventional gas overlap, so there is a statistical uncertainty regarding whether shale gas emissions are indeed lower than conventional gas emissions. This life-cycle analysis provides insight into the critical stages in the natural gas industry where emissions occur and where opportunities exist to reduce the greenhouse gas footprint of natural gas.

  9. Correlation of gas dynamics and dust in the evolved filament G82.65-02.00

    Science.gov (United States)

    Saajasto, M.; Juvela, M.; Dobashi, K.; Shimoikura, T.; Ristorcelli, I.; Montillaud, J.; Marshall, D. J.; Malinen, J.; Pelkonen, V.-M.; Fehér, O.; Rivera-Ingraham, A.; Toth, L. V.; Montier, L.; Bernard, J.-Ph.; Onishi, T.

    2017-12-01

    Context. The combination of line and continuum observations can provide vital insight into the formation and fragmentation of filaments and the initial conditions for star formation. We have carried out line observations to map the kinematics of an evolved, actively star forming filament G82.65-2.00. The filament was first identified from the Planck data as a region of particularly cold dust emission and was mapped at 100-500 μm as a part of the Herschel key program Galactic Cold Cores. The Herschel observations cover the central part of the filament, corresponding to a filament length of 12 pc at the assumed distance of 620 pc. Aims: CO observations show that the filament has an intriguing velocity field with several velocity components around the filament. In this paper, we study the velocity structure in detail, to quantify possible mass accretion rate onto the filament, and study the masses of the cold cores located in the filament. Methods: We have carried out line observations of several molecules, including CO isotopologues, HCO+, HCN, and CS with the Osaka 1.85 m telescope and the Nobeyama 45 m telescope. The spectral line data are used to derive velocity and column density information. Results: The observations reveal several velocity components in the field, with strongest line emission concentrated to velocity range [3,5] km s-1. The column density of molecular hydrogen along the filament varies from 1.0 to 2.3 × 1022cm2. We have examined six cold clumps from the central part of the filament. The clumps have masses in the range 10-20M⊙ ( 70 M⊙ in total) and are close to or above the virial mass. Furthermore, the main filament is heavily fragmented and most of the substructures have a mass lower than or close to the virial mass, suggesting that the filament is dispersing as a whole. Position-velocity maps of 12CO and 13CO lines indicate that at least one of the striations is kinematically connected to two of the clumps, potentially indicating mass

  10. The Detection of Evolved Oxygen from the Rocknest Eolian Bedform Material by the Sample Analysis at Mars(SAM) instrument at the Mars Curiosity Landing Site

    Science.gov (United States)

    Sutter, B.; Archer, D.; Ming, D.; Eigenbrode, J. L.; Franz, H.; Glavin, D. P.; McAdam, A.; Mahaffy, P.; Stern, J.; Navarro-Gonzalex, R.; hide

    2013-01-01

    The Sample Analysis at Mars (SAM) instrument onboard the Curiosity rover detected an O2 gas release from the Rocknest eolain bedform (Fig. 1). The detection of perchlorate (ClO4-) by the Mars Phoenix Lander s Wet Chemistry Laboratory (WCL) [1] suggests that perchlorate is a possible candidate for evolved O2 release detected by SAM. The perchlorate would also serve as a source of chlorine in the chlorinated hydrocarbons detected by the SAM quadrupole mass spectrometer (QMS) and gas chromatography/mass spectrometer (GCMS) [2,3]. Chlorates (ClO3-) [4,5] and/or superoxides [6] may also be sources of evolved O2 from the Rocknest materials. The work objectives are to 1) evaluate the O2 release temperatures from Rocknest materials, 2) compare these O2 release temperatures with a series of perchlorates and chlorates, and 3) evaluate superoxide O2- sources and possible perchlorate interactions with other Rocknest phases during QMS analysis.

  11. OPIC Greenhouse Gas Emissions Analysis Details

    Data.gov (United States)

    Overseas Private Investment Corporation — Summary project inventory with independent analysis to quantify the greenhouse gas ("GHG") emissions directly attributable to projects to which the Overseas Private...

  12. Evolving Cuban-CARICOM relations : a comparative cost/benefit analysis

    Directory of Open Access Journals (Sweden)

    Michael Erisman

    1995-01-01

    Full Text Available Survey of the basic developmental dynamics involved in the evolving Cuban-CARICOM relationship. On the basis of a cost-risk/benefit analysis, the author provides some projections regarding the future of this relationship. He concludes that there appear sufficient potential benefits for both sides to deepen the relationship. Cuban-CARICOM integration, however, has no top priority for either partner.

  13. [Central venous blood gas analysis].

    Science.gov (United States)

    Marano, Marco; D'Amato, Anna; Guiotto, Giovanna; Schiraldi, Fernando

    2015-01-01

    The hemodialysis might interfere with patients hemodynamic, as the technique allows a sophisticated game with extra and intravascular fluids. As the cardiocirculatory response could sometimes be unpredictable, it is interesting to collect valuable information by reaching a deep understanding of the tissue metabolism which is mirrored by the blood gas analysis of variations in arterial and central venous blood samples. Particularly interesting are the time course variations of the central venous hemoglobin saturation (ScvO2), which are directly related to the patient with O2-demand as well as to the O2-Delivery (DO2). The ScvO2 is determined by four parameters (cardiac output, Hb concentration, arterial Hb saturation and O2 consumption): If the fluids subtraction during dialysis was about to determine an occult hypoperfusion, the ScvO2 reduction would be a timely warning sign to be considered. Moreover, while the normal veno-arterial PCO2 difference is 2-4 mmHg, whenever a mismatch between O2-demand and DO2arise, a larger v-aPCO2 difference should be observed.

  14. Near-wall measurements of the bubble- and Lorentz-force-driven convection at gas-evolving electrodes

    Science.gov (United States)

    Baczyzmalski, Dominik; Weier, Tom; Kähler, Christian J.; Cierpka, Christian

    2015-08-01

    Chemical energy storage systems, e.g., in the form of hydrogen or methanol, have a great potential for the establishment of volatile renewable energy sources due to the large energy density. The efficiency of hydrogen production through water electrolysis is, however, limited by gas bubbles evolving at the electrode's surface and can be enhanced by an accelerated bubble detachment. In order to characterize the complex multi-phase flow near the electrode, simultaneous measurements of the fluid velocities and the size and trajectories of hydrogen bubbles were performed in a water electrolyzer. The liquid phase velocity was measured by PIV/PTV, while shadowgraphy was used to determine the bubble trajectories. Special measurement and evaluation techniques had to be applied as the measurement uncertainty is strongly affected by the high void fraction close to the wall. In particular, the application of an advanced PTV scheme allowed for more precise fluid velocity measurements closer to electrode. Based on these data, stability characteristics of the near-wall flow were evaluated and compared to that of a wall jet. PTV was used as well to investigate the effect of Lorentz forces on the near-wall fluid velocities. The results show a significantly increased wall parallel liquid phase velocity with increasing Lorentz forces. It is presumed that this enhances the detachment of hydrogen bubbles from the electrode surface and, consequently, decreases the fractional bubble coverage and improves the efficiency. In addition, the effect of large rising bubbles with path oscillations on the near-wall flow was investigated. These bubbles can have a strong impact on the mass transfer near the electrode and thus affect the performance of the process.

  15. Gas Hydrate Petroleum System Analysis

    Science.gov (United States)

    Collett, T. S.

    2012-12-01

    In a gas hydrate petroleum system, the individual factors that contribute to the formation of gas hydrate accumulations, such as (1) gas hydrate pressure-temperature stability conditions, (2) gas source, (3) gas migration, and (4) the growth of the gas hydrate in suitable host sediment can identified and quantified. The study of know and inferred gas hydrate accumulations reveal the occurrence of concentrated gas hydrate is mostly controlled by the presence of fractures and/or coarser grained sediments. Field studies have concluded that hydrate grows preferentially in coarse-grained sediments because lower capillary pressures in these sediments permit the migration of gas and nucleation of hydrate. Due to the relatively distal nature of the deep marine geologic settings, the overall abundance of sand within the shallow geologic section is usually low. However, drilling projects in the offshore of Japan, Korea, and in the Gulf of Mexico has revealed the occurrence of significant hydrate-bearing sand reservoirs. The 1999/2000 Japan Nankai Trough drilling confirmed occurrence of hydrate-bearing sand-rich intervals (interpreted as turbidite fan deposits). Gas hydrate was determined to fill the pore spaces in these deposits, reaching saturations up to 80% in some layers. A multi-well drilling program titled "METI Toaki-oki to Kumano-nada" also identified sand-rich reservoirs with pore-filling hydrate. The recovered hydrate-bearing sand layers were described as very-fine- to fine-grained turbidite sand layers measuring from several centimeters up to a meter thick. However, the gross thickness of the hydrate-bearing sand layers were up to 50 m. In 2010, the Republic of Korea conducted the Second Ulleung Basin Gas Hydrate (UBGH2) Drilling Expedition. Seismic data clearly showed the development of a thick, potential basin wide, sedimentary sections characterized by mostly debris flows. The downhole LWD logs and core data from Site UBGH2-5 reveal that each debris flows is

  16. Reactions Involving Calcium and Magnesium Sulfates as Potential Sources of Sulfur Dioxide During MSL SAM Evolved Gas Analyses

    Science.gov (United States)

    McAdam, A. C.; Knudson, C. A.; Sutter, B.; Franz, H. B.; Archer, P. D., Jr.; Eigenbrode, J. L.; Ming, D. W.; Morris, R. V.; Hurowitz, J. A.; Mahaffy, P. R.; hide

    2016-01-01

    The Sample Analysis at Mars (SAM) and Chemistry and Mineralogy (CheMin) instruments on the Mars Science Laboratory (MSL) have analyzed several subsamples of 860 C). Sulfides or Fe sulfates were detected by CheMin (e.g., CB, MJ, BK) and could contribute to the high temperature SO2 evolution, but in most cases they are not present in enough abundance to account for all of the SO2. This additional SO2 could be largely associated with x-ray amorphous material, which comprises a significant portion of all samples. It can also be attributed to trace S phases present below the CheMin detection limit, or to reactions which lower the temperatures of SO2 evolution from sulfates that are typically expected to thermally decompose at temperatures outside the SAM temperature range (e.g., Ca and Mg sulfates). Here we discuss the results of SAM-like laboratory analyses targeted at understanding this last possibility, focused on understanding if reactions of HCl or an HCl evolving phase (oxychlorine phases, chlorides, etc.) and Ca and Mg sulfates can result in SO2 evolution in the SAM temperature range.

  17. Insights into the growth rate of spatially evolving plane turbulent free-shear layers from 2D vortex-gas simulations

    Science.gov (United States)

    Suryanarayanan, Saikishan; Narasimha, Roddam

    2017-02-01

    Although the free-shear or mixing layer has been a subject of extensive research over nearly a century, there are certain fundamental issues that remain controversial. These include the influence of initial and downstream conditions on the flow, the effect of velocity ratio across the layer, and the nature of any possible coupling between small scale dynamics and the large scale evolution of layer thickness. In the spirit of the temporal vortex-gas simulations of Suryanarayanan et al. ["Free turbulent shear layer in a point vortex gas as a problem in nonequilibrium statistical mechanics," Phys. Rev. E 89, 013009 (2014)], we revisit the simple 2D inviscid vortex-gas model with extensive computations and detailed analysis, in order to gain insights into some of the above issues. Simulations of the spatially evolving vortex-gas shear layer are carried out at different velocity ratios using a computational model based on the work of Basu et al. ["Vortex sheet simulation of a plane canonical mixing layer," Comput. Fluids 21, 1-30 (1992) and "Modelling plane mixing layers using vortex points and sheets," Appl. Math. Modell. 19, 66-75 (1995)], but with a crucial improvement that ensures conservation of global circulation. The simulations show that the conditions imposed at the origin of the free shear layer and at the exit to the computational domain can affect flow evolution in their respective downstream and upstream neighbourhoods, the latter being particularly strong in the single stream limit. In between these neighbourhoods at the ends is a regime of universal self-preserving growth rate given by a universal function of velocity ratio. The computed growth rates are generally located within the scatter of experimental data on plane mixing layers and closely agree with recent high Reynolds number experiments and 3D large eddy simulation studies. These findings support the view that observed free-shear layer growth can be largely explained by the 2D vortex dynamics of

  18. Analysis of K west basin canister gas

    Energy Technology Data Exchange (ETDEWEB)

    Trimble, D.J., Fluor Daniel Hanford

    1997-03-06

    Gas and Liquid samples have been collected from a selection of the approximately 3,820 spent fuel storage canisters in the K West Basin. The samples were taken to characterize the contents of the gas and water in the canisters providing source term information for two subprojects of the Spent Nuclear Fuel Project (SNFP) (Fulton 1994): the K Basins Integrated Water Treatment System Subproject (Ball 1996) and the K Basins Fuel Retrieval System Subproject (Waymire 1996). The barrels of ten canisters were sampled for gas and liquid in 1995, and 50 canisters were sampled in a second campaign in 1996. The analysis results from the first campaign have been reported (Trimble 1995a, 1995b, 1996a, 1996b). The analysis results from the second campaign liquid samples have been documented (Trimble and Welsh 1997; Trimble 1997). This report documents the results for the gas samples from the second campaign and evaluates all gas data in terms of expected releases when opening the canisters for SNFP activities. The fuel storage canisters consist of two closed and sealed barrels, each with a gas trap. The barrels are attached at a trunion to make a canister, but are otherwise independent (Figure 1). Each barrel contains up to seven N Reactor fuel element assemblies. A gas space of nitrogen was established in the top 2.2 to 2.5 inches (5.6 to 6.4 cm) of each barrel. Many of the fuel elements were damaged allowing the metallic uranium fuel to be corroded by the canister water. The corrosion releases fission products and generates hydrogen gas. The released gas mixes with the gas-space gas and excess gas passes through the gas trap into the basin water. The canister design does not allow canister water to be exchanged with basin water.

  19. Risk-Based Prioritization of Research for Aviation Security Using Logic-Evolved Decision Analysis

    Science.gov (United States)

    Eisenhawer, S. W.; Bott, T. F.; Sorokach, M. R.; Jones, F. P.; Foggia, J. R.

    2004-01-01

    The National Aeronautics and Space Administration is developing advanced technologies to reduce terrorist risk for the air transportation system. Decision support tools are needed to help allocate assets to the most promising research. An approach to rank ordering technologies (using logic-evolved decision analysis), with risk reduction as the metric, is presented. The development of a spanning set of scenarios using a logic-gate tree is described. Baseline risk for these scenarios is evaluated with an approximate reasoning model. Illustrative risk and risk reduction results are presented.

  20. Development Roadmap of an Evolvable and Extensible Multi-Mission Telecom Planning and Analysis Framework

    Science.gov (United States)

    Cheung, Kar-Ming; Tung, Ramona H.; Lee, Charles H.

    2003-01-01

    In this paper, we describe the development roadmap and discuss the various challenges of an evolvable and extensible multi-mission telecom planning and analysis framework. Our long-term goal is to develop a set of powerful flexible telecommunications analysis tools that can be easily adapted to different missions while maintain the common Deep Space Communication requirements. The ability of re-using the DSN ground models and the common software utilities in our adaptations has contributed significantly to our development efforts measured in terms of consistency, accuracy, and minimal effort redundancy, which can translate into shorter development time and major cost savings for the individual missions. In our roadmap, we will address the design principles, technical achievements and the associated challenges for following telecom analysis tools (i) Telecom Forecaster Predictor - TFP (ii) Unified Telecom Predictor - UTP (iii) Generalized Telecom Predictor - GTP (iv) Generic TFP (v) Web-based TFP (vi) Application Program Interface - API (vii) Mars Relay Network Planning Tool - MRNPT.

  1. Sensitivity analysis of a branching process evolving on a network with application in epidemiology

    CERN Document Server

    Hautphenne, Sophie; Delvenne, Jean-Charles; Blondel, Vincent D

    2015-01-01

    We perform an analytical sensitivity analysis for a model of a continuous-time branching process evolving on a fixed network. This allows us to determine the relative importance of the model parameters to the growth of the population on the network. We then apply our results to the early stages of an influenza-like epidemic spreading among a set of cities connected by air routes in the United States. We also consider vaccination and analyze the sensitivity of the total size of the epidemic with respect to the fraction of vaccinated people. Our analysis shows that the epidemic growth is more sensitive with respect to transmission rates within cities than travel rates between cities. More generally, we highlight the fact that branching processes offer a powerful stochastic modeling tool with analytical formulas for sensitivity which are easy to use in practice.

  2. Blood gas analysis for bedside diagnosis.

    Science.gov (United States)

    Singh, Virendra; Khatana, Shruti; Gupta, Pranav

    2013-07-01

    Arterial blood gas is an important routine investigation to monitor the acid-base balance of patients, effectiveness of gas exchange, and the state of their voluntary respiratory control. Majority of the oral and maxillofacial surgeons find it difficult to interpret and clinically correlate the arterial blood gas report in their everyday practice. This has led to underutilization of this simple tool. The present article aims to simplify arterial blood gas analysis for a rapid and easy bedside interpretation. In context of oral and maxillofacial surgery, arterial blood gas analysis plays a vital role in the monitoring of postoperative patients, patients receiving oxygen therapy, those on intensive support, or with maxillofacial trauma with significant blood loss, sepsis, and comorbid conditions like diabetes, kidney disorders, Cardiovascular system (CVS) conditions, and so on. The value of this analysis is limited by the understanding of the basic physiology and ability of the surgeon to interpret the report. Using a systematic and logical approach by using these steps would make the interpretation simple and easy to use for oral and maxillofacial surgeons.

  3. Maintaining evolvability.

    Science.gov (United States)

    Crow, James F

    2008-12-01

    is yet to be determined. It is likely that only a case-by-case analysis will provide the answers. Despite the difficulties that complex interactions cause for evolution in Mendelian populations, such populations nevertheless evolve very well. Longlasting species must have evolved mechanisms for coping with such problems. Since such difficulties do not arise in asexual populations, a comparison of epistatic patterns in closely related sexual and asexual species might provide some important insights.

  4. A miniaturized optical gas sensor for natural gas analysis

    NARCIS (Netherlands)

    Ayerden, N.P.

    2016-01-01

    The depletion of domestic reserves and the growing use of sustainable resources forces a transition from the locally produced natural gas with a well-known composition toward the ‘new’ gas with a more flexible composition in the Netherlands. For safe combustion and proper billing, the natural gas

  5. Comparative transcriptomic analysis reveals phenol tolerance mechanism of evolved Chlorella strain.

    Science.gov (United States)

    Zhou, Lin; Cheng, Dujia; Wang, Liang; Gao, Juan; Zhao, Quanyu; Wei, Wei; Sun, Yuhan

    2017-03-01

    The growth of microalgae is inhibited by high concentration phenol due to reactive oxygen species. An evolved strain tolerated to 500mg/L phenol, Chlorella sp. L5, was obtained in previous study. In this study, comparative transcriptomic analysis was performed for Chlorella sp. L5 and its original strain (Chlorella sp. L3). The tolerance mechanism of Chlorella sp. L5 for high concentration phenol was explored on genome scale. It was identified that the up-regulations of the related genes according to antioxidant enzymes (SOD, APX, CAT and GR) and carotenoids (astaxanthin, lutein and lycopene) biosynthesis had critical roles to tolerate high concentration phenol. In addition, most of genes of PS I, PS II, photosynthetic electron transport chain and starch biosynthesis were also up-regulated. It was consistent to the experimental results of total carbohydrate contents of Chlorella sp. L3 and Chlorella sp. L5 under 0mg/L and 500mg/L phenol. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Identification of fast-evolving genes in the scleractinian coral Acropora using comparative EST analysis.

    Directory of Open Access Journals (Sweden)

    Akira Iguchi

    Full Text Available To identify fast-evolving genes in reef-building corals, we performed direct comparative sequence analysis with expressed sequence tag (EST datasets from two acroporid species: Acropora palmata from the Caribbean Sea and A. millepora from the Great Barrier Reef in Australia. Comparison of 589 independent sequences from 1,421 A. palmata contigs, with 10,247 A. millepora contigs resulted in the identification of 196 putative homologues. Most of the homologous pairs demonstrated high amino acid similarities (over 90%. Comparisons of putative homologues showing low amino acid similarities (under 90% among the Acropora species to the near complete datasets from two other cnidarians (Hydra magnipapillata and Nematostella vectensis implied that some were non-orthologous. Within 86 homologous pairs, 39 exhibited dN/dS ratios significantly less than 1, suggesting that these genes are under purifying selection associated with functional constraints. Eight independent genes showed dN/dS ratios exceeding 1, while three deviated significantly from 1, suggesting that these genes may play important roles in the adaptive evolution of Acropora. Our results also indicated that CEL-III lectin was under positive selection, consistent with a possible role in immunity or symbiont recognition. Further studies are needed to clarify the possible functions of the genes under positive selection to provide insight into the evolutionary process of corals.

  7. THE MOLECULAR GAS CONTENT OF z = 3 LYMAN BREAK GALAXIES: EVIDENCE OF A NON-EVOLVING GAS FRACTION IN MAIN-SEQUENCE GALAXIES AT z > 2

    Energy Technology Data Exchange (ETDEWEB)

    Magdis, Georgios E.; Rigopoulou, D. [Department of Physics, University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom); Daddi, E.; Sargent, M.; Elbaz, D.; Gobat, R.; Tan, Q.; Aussel, H. [CEA, Laboratoire AIM, Irfu/SAp, F-91191 Gif-sur-Yvette (France); Dannerbauer, H. [Institut fuer Astronophysik, Universitaet Wien, Tuerkenschanzstrasse 17, A-1180 Wien (Austria); Feruglio, C. [IRAM-Institut de RadioAstronomie Millimetrique 300 rue de la Piscine, Domaine Universitaire, F-38406 Saint Martin d' Heres (France); Charmandaris, V. [Department of Physics and Institute of Theoretical and Computational Physics, University of Crete, GR-71003 Heraklion (Greece); Dickinson, M. [NOAO, 950 N. Cherry Avenue, Tucson, AZ 85719 (United States); Reddy, N. [Department of Physics and Astronomy, University of California, Riverside 900 University, Avenue Riverside, CA 92507 (United States)

    2012-10-10

    We present observations of the CO[J = 3 {yields} 2] emission toward two massive and infrared luminous Lyman break galaxies (LBGs) at z = 3.21 and z = 2.92, using the IRAM Plateau de Bure Interferometer, placing first constraints on the molecular gas masses (M{sub gas}) of non-lensed LBGs. Their overall properties are consistent with those of typical (main-sequence) galaxies at their redshifts, with specific star formation rates {approx}1.6 and {approx}2.2 Gyr{sup -1}, despite their large infrared luminosities (L{sub IR} Almost-Equal-To (2-3) Multiplication-Sign 10{sup 12} L{sub Sun }) derived from Herschel. With one plausible CO detection (spurious detection probability of 10{sup -3}) and one upper limit, we investigate the evolution of the molecular gas-to-stellar mass ratio (M{sub gas}/M{sub *}) with redshift. Our data suggest that the steep evolution of M{sub gas}/M{sub *} of normal galaxies up to z {approx} 2 is followed by a flattening at higher redshifts, providing supporting evidence for the existence of a plateau in the evolution of the specific star formation rate at z > 2.5.

  8. Redistribution of CO at the location of the CO ice line in evolving gas and dust disks

    Science.gov (United States)

    Stammler, Sebastian Markus; Birnstiel, Tilman; Panić, Olja; Dullemond, Cornelis Petrus; Dominik, Carsten

    2017-04-01

    Context. Ice lines are suggested to play a significant role in grain growth and planetesimal formation in protoplanetary disks. Evaporation fronts directly influence the gas and ice abundances of volatile species in the disk and therefore the coagulation physics and efficiency and the chemical composition of the resulting planetesimals. Aims: In this work, we investigate the influence of the existence of the CO ice line on particle growth and on the distribution of CO in the disk. Methods: We include the possibility of tracking the CO content and/or other volatiles in particles and in the gas in our existing dust coagulation and disk evolution model and present a method for studying evaporation and condensation of CO using the Hertz-Knudsen equation. Our model does not yet include fragmentation, which will be part of further investigations. Results: We find no enhanced grain growth immediately outside the ice line where the particle size is limited by radial drift. Instead, we find a depletion of solid material inside the ice line, which is solely due to evaporation of the CO. Such a depression inside the ice line may be observable and may help to quantify the processes described in this work. Furthermore, we find that the viscosity and diffusivity of the gas heavily influence the re-distribution of vaporized CO at the ice line and can lead to an increase in the CO abundance by up to a factor of a few in the region just inside the ice line. Depending on the strength of the gaseous transport mechanisms, the position of the ice line in our model can change by up to 10 AU and consequently, the temperature at that location can range from 21 to 23 K.

  9. GAS CHROMATOGRAPHIC AND SPECTROSCOPIC ANALYSIS OF ...

    African Journals Online (AJOL)

    Peroxyformic acid prepared in-situ was employed for epoxidation of canola oil in the presence of toluene. Gas chromatographic analysis of the product revealed the following species: C16:0; C18:0; C18:1; C18:2; C18:3; monoepoxy C18:0; monoepoxy C18:1; monoepoxy C18:2; diepoxy C18:0; diepoxy C18:1 and triepoxy ...

  10. The System Dynamics Analysis on the Evolvement of Mechanism of Convention and Exhibition Industry

    Science.gov (United States)

    Wu, Xin-Ju; Sun, Ming-Jun

    The purpose of this paper is to defines the factors and the way which influence the evolvement of convention and exhibition industry cluster (CEIC for short). From the perspective of system dynamics, the author designed the system flow chart and SD Model to show how the different factors exert positive/negative influencing on the CEIC. The author used Vensim to stimulate the SD Model and to verify its validity and application value. The research shows the evolvement of CEIC is the result of combined strength which comes from both the external and the internal system, the supply factors of the internal system and the market demand from the external system are key strengths for the evolvement of CEIC system. The model had a high fitting precision and a good predicting ability .The research can be used practically and theoretically for the development of convention and exhibition industry (C&E industry for short).

  11. Environmental analysis for pipeline gas demonstration plants

    Energy Technology Data Exchange (ETDEWEB)

    Stinton, L.H.

    1978-09-01

    The Department of Energy (DOE) has implemented programs for encouraging the development and commercialization of coal-related technologies, which include coal gasification demonstration-scale activities. In support of commercialization activities the Environmental Analysis for Pipeline Gas Demonstration Plants has been prepared as a reference document to be used in evaluating potential environmental and socioeconomic effects from construction and operation of site- and process-specific projects. Effluents and associated impacts are identified for six coal gasification processes at three contrasting settings. In general, impacts from construction of a high-Btu gas demonstration plant are similar to those caused by the construction of any chemical plant of similar size. The operation of a high-Btu gas demonstration plant, however, has several unique aspects that differentiate it from other chemical plants. Offsite development (surface mining) and disposal of large quantities of waste solids constitute important sources of potential impact. In addition, air emissions require monitoring for trace metals, polycyclic aromatic hydrocarbons, phenols, and other emissions. Potential biological impacts from long-term exposure to these emissions are unknown, and additional research and data analysis may be necessary to determine such effects. Possible effects of pollutants on vegetation and human populations are discussed. The occurrence of chemical contaminants in liquid effluents and the bioaccumulation of these contaminants in aquatic organisms may lead to adverse ecological impact. Socioeconomic impacts are similar to those from a chemical plant of equivalent size and are summarized and contrasted for the three surrogate sites.

  12. How do obligate parasites evolve? A multi-gene phylogenetic analysis of downy mildews.

    Science.gov (United States)

    Göker, Markus; Voglmayr, Hermann; Riethmüller, Alexandra; Oberwinkler, Franz

    2007-02-01

    Plant parasitism has independently evolved as a nutrition strategy in both true fungi and Oomycetes (stramenopiles). A large number of species within phytopathogenic Oomycetes, the so-called downy mildews, are defined as obligate biotrophs since they have not, to date, been cultured on any artificial medium. Other genera like Phytophthora and Pythium can in general be cultured on standard or non-standard agar media. Within all three groups there are many important plant pathogens responsible for severe economic losses as well as damage to natural ecosystems. Although they are important model systems to elucidate the evolution of obligate parasites, the phylogenetic relationships between these genera have not been clearly resolved. Based on the most comprehensive sampling of downy mildew genera to date and a representative sample of Phytophthora subgroups, we inferred the phylogenetic relationships from a multi-gene dataset containing both coding and non-coding nuclear and mitochondrial loci. Phylogenetic analyses were conducted under several optimality criteria and the results were largely consistent between all the methods applied. Strong support is achieved for monophyly of a clade comprising both the genus Phytophthora and the obligate biotrophic species. The facultatively parasitic genus Phytophthora is shown to be at least partly paraphyletic. Monophyly of a cluster nested within Phytophthora containing all obligate parasites is strongly supported. Within the obligate biotrophic downy mildews, four morphologically or ecologically well-defined subgroups receive statistical support: (1) A cluster containing all species with brownish-violet conidiosporangia, i.e., the genera Peronospora and Pseudoperonospora; (2) a clade comprising the genera with vesicular to pyriform haustoria (Basidiophora, Benua, Bremia, Paraperonospora, Plasmopara, Plasmoverna, Protobremia); (3) a group containing species included in Hyaloperonospora and Perofascia which almost exclusively

  13. Thermodynamic Analysis of Supplementary-Fired Gas Turbine Cycles

    DEFF Research Database (Denmark)

    Elmegaard, Brian; Henriksen, Ulrik Birk; Qvale, Einar Bjørn

    2003-01-01

    This paper presents an analysis of the possibilities for improving the efficiency of an indi-rectly biomass-fired gas turbine (IBFGT) by supplementary direct gas-firing. The supple-mentary firing may be based on natural gas, biogas or pyrolysis gas. Intuitively, sup-plementary firing is expected ...

  14. Thermodynamic Analysis of Supplementary-Fired Gas Turbine Cycles

    DEFF Research Database (Denmark)

    Elmegaard, Brian; Henriksen, Ulrik Birk; Qvale, Einar Bjørn

    2002-01-01

    This paper presents an analysis of the possibilities for improving the efficiency of an indirectly biomass-fired gas turbine (IBFGT) by supplementary direct gas-firing. The supplementary firing may be based on natural gas, biogas, or pyrolysis gas. {The interest in this cycle arise from a recent ...

  15. FTIR gas chromatographic analysis of perfumes

    Science.gov (United States)

    Diederich, H.; Stout, Phillip J.; Hill, Stephen L.; Krishnan, K.

    1992-03-01

    Perfumes, natural or synthetic, are complex mixtures consisting of numerous components. Gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) techniques have been extensively utilized for the analysis of perfumes and essential oils. A limited number of perfume samples have also been analyzed by FT-IR gas chromatographic (GC-FTIR) techniques. Most of the latter studies have been performed using the conventional light pipe (LP) based GC-FTIR systems. In recent years, cold-trapping (in a matrix or neat) GC-FTIR systems have become available. The cold-trapping systems are capable of sub-nanogram sensitivities. In this paper, comparison data between the LP and the neat cold-trapping GC- FTIR systems is presented. The neat cold-trapping interface is known as Tracer. The results of GC-FTIR analysis of some commercial perfumes is also presented. For comparison of LP and Tracer GC-FTIR systems, a reference (synthetic) mixture containing 16 major and numerous minor constituents was used. The components of the mixture are the compounds commonly encountered in commercial perfumes. The GC-FTIR spectra of the reference mixture was obtained under identical chromatographic conditions from an LP and a Tracer system. A comparison of the two sets of data thus generated do indeed show the enhanced sensitivity level of the Tracer system. The comparison also shows that some of the major components detected by the Tracer system were absent from the LP data. Closer examination reveals that these compounds undergo thermal decomposition on contact with the hot gold surface that is part of the LP system. GC-FTIR data were obtained for three commercial perfume samples. The major components of these samples could easily be identified by spectra search against a digitized spectral library created using the Tracer data from the reference mixture.

  16. Gas Chromatography-Mass Spectrometric Analysis of Essential Oil ...

    African Journals Online (AJOL)

    C) for subsequent experiments. Analysis of the essential oil. Capillary gas chromatography was performed using Hewlett–Packard 5890 gas chromatograph equipped with a flame ionization detector and fused silica capillary column HP-5 (5 % ...

  17. E Unibus Plurum: genomic analysis of an experimentally evolved polymorphism in Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Margie A Kinnersley

    2009-11-01

    Full Text Available Microbial populations founded by a single clone and propagated under resource limitation can become polymorphic. We sought to elucidate genetic mechanisms whereby a polymorphism evolved in Escherichia coli under glucose limitation and persisted because of cross-feeding among multiple adaptive clones. Apart from a 29 kb deletion in the dominant clone, no large-scale genomic changes distinguished evolved clones from their common ancestor. Using transcriptional profiling on co-evolved clones cultured separately under glucose-limitation we identified 180 genes significantly altered in expression relative to the common ancestor grown under similar conditions. Ninety of these were similarly expressed in all clones, and many of the genes affected (e.g., mglBAC, mglD, and lamB are in operons coordinately regulated by CRP and/or rpoS. While the remaining significant expression differences were clone-specific, 93% were exhibited by the majority clone, many of which are controlled by global regulators, CRP and CpxR. When transcriptional profiling was performed on adaptive clones cultured together, many expression differences that distinguished the majority clone cultured in isolation were absent, suggesting that CpxR may be activated by overflow metabolites removed by cross-feeding strains in co-culture. Relative to their common ancestor, shared expression differences among adaptive clones were partly attributable to early-arising shared mutations in the trans-acting global regulator, rpoS, and the cis-acting regulator, mglO. Gene expression differences that distinguished clones may in part be explained by mutations in trans-acting regulators malT and glpK, and in cis-acting sequences of acs. In the founder, a cis-regulatory mutation in acs (acetyl CoA synthetase and a structural mutation in glpR (glycerol-3-phosphate repressor likely favored evolution of specialists that thrive on overflow metabolites. Later-arising mutations that led to specialization

  18. Cooled gas turbine blade edge flow analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mendonca, Marcio Teixeira de [Instituto Tecnologico de Aeronautica, Divisao de Engenharia Mecanica Aeronautica ITA/IEM, Sao Jose dos Campos, SP (Brazil)], e-mail: marcio@ita.br

    2010-07-01

    The flow on the rotating blades of a turbine is unsteady due to the wake of the stator blade row upstream. This unsteadiness is a source of losses and complex flow structures on the rotor blade due to the variation on the turbulence levels and location of the boundary layer laminar to turbulent transition. Convective cooled blades often time have cooling air ejected at the trailing edge right at the blade wake. The present investigation presents an analysis of a canonical flow consistent with the flow topology found at the trailing edge of a gas turbine blade with coolant ejection. A hydrodynamic stability analysis is performed for the combined wake and jet velocity profiles given by a gaussian distribution representing the turbulent rms wake and a laminar jet superposed. The growth rate of any instability found on the flow is an indication of faster mixing, resulting in a reduction on the wake velocity defect and consequently on the complexity associated with it. The results show that increasing the Mach number or the three-dimensionality of the disturbances result in a reduction of the amplification rate. When the flow at the trailing edge is modified by a jet, the amplification rates are lower, but the range of unstable stream wise wavenumbers is larger. (author)

  19. What Causes Environmental Inequalities and Related Health Effects? An Analysis of Evolving Concepts

    Science.gov (United States)

    Kruize, Hanneke; Droomers, Mariël; van Kamp, Irene; Ruijsbroek, Annemarie

    2014-01-01

    Early environmental justice studies were exposure-oriented, lacked an integrated approach, and did not address the health impact of environmental inequalities. A coherent conceptual framework, needed to understand and tackle environmental inequalities and the related health effects, was lacking. We analyzed the more recent environmental justice literature to find out how conceptual insights have evolved. The conceptual framework of the WHO Commission on Social Determinants of Health (CSDH) was analyzed for additional explanations for environmental inequalities and the related health effects. This paper points out that recent environmental justice studies have broadened their scope by incorporating a broader set of physical and social environmental indicators, and by focusing on different geographic levels and on health impacts of environmental inequalities. The CSDH framework provided additional elements such as the role of structural determinants, the role of health-related behavior in relation to the physical and social environment, access to health care, as well as the life course perspective. Incorporating elements of the CSDH framework into existing environmental justice concepts, and performing more empirical research on the interactions between the different determinants at different geographical levels would further improve our understanding of environmental inequalities and their health effects and offer new opportunities for policy action. PMID:24886752

  20. Analysis of Adsorbed Natural Gas Tank Technology

    Science.gov (United States)

    Knight, Ernest; Schultz, Conrad; Rash, Tyler; Dohnke, Elmar; Stalla, David; Gillespie, Andrew; Sweany, Mark; Seydel, Florian; Pfeifer, Peter

    With gasoline being an ever decreasing finite resource and with the desire to reduce humanity's carbon footprint, there has been an increasing focus on innovation of alternative fuel sources. Natural gas burns cleaner, is more abundant, and conforms to modern engines. However, storing compressed natural gas (CNG) requires large, heavy gas cylinders, which limits space and fuel efficiency. Adsorbed natural gas (ANG) technology allows for much greater fuel storage capacity and the ability to store the gas at a much lower pressure. Thus, ANG tanks are much more flexible in terms of their size, shape, and weight. Our ANG tank employs monolithic nanoporous activated carbon as its adsorbent material. Several different configurations of this Flat Panel Tank Assembly (FPTA) along with a Fuel Extraction System (FES) were examined to compare with the mass flow rate demands of an engine.

  1. Examining Evolving Performance on the Force Concept Inventory Using Factor Analysis

    Science.gov (United States)

    Semak, M. R.; Dietz, R. D.; Pearson, R. H.; Willis, C. W

    2017-01-01

    The application of factor analysis to the "Force Concept Inventory" (FCI) has proven to be problematic. Some studies have suggested that factor analysis of test results serves as a helpful tool in assessing the recognition of Newtonian concepts by students. Other work has produced at best ambiguous results. For the FCI administered as a…

  2. Using Willie's Acid-Base Box for Blood Gas Analysis

    Science.gov (United States)

    Dietz, John R.

    2011-01-01

    In this article, the author describes a method developed by Dr. William T. Lipscomb for teaching blood gas analysis of acid-base status and provides three examples using Willie's acid-base box. Willie's acid-base box is constructed using three of the parameters of standard arterial blood gas analysis: (1) pH; (2) bicarbonate; and (3) CO[subscript…

  3. Gas Chromatography-Mass Spectrometric Analysis of Essential Oil ...

    African Journals Online (AJOL)

    Gas Chromatography-Mass Spectrometric Analysis of Essential Oil of Aerial Parts of Glycosmis parviflora (Sims) Little (Rutaceae) ... Gas chromatography/mass spectrometric (GC/MS) analysis (HP-5MS column) of the essential oil was performed and the toxicity of the oil determined by contact test. Results: A total of 37 ...

  4. Review of Sector and Regional Trends in U.S. Electricity Markets. Focus on Natural Gas. Natural Gas and the Evolving U.S. Power Sector Monograph Series. Number 1 of 3

    Energy Technology Data Exchange (ETDEWEB)

    Logan, Jeffrey; Medlock III, Kenneth B.; Boyd, William C.

    2015-10-15

    This study explores dynamics related to natural gas use at the national, sectoral, and regional levels, with an emphasis on the power sector. It relies on a data set from SNL Financial to analyze recent trends in the U.S. power sector at the regional level. The research aims to provide decision and policy makers with objective and credible information, data, and analysis that informs their discussions of a rapidly changing energy system landscape. This study also summarizes regional changes in natural gas demand within the power sector. The transition from coal to natural gas is occurring rapidly along the entire eastern portion of the country, but is relatively stagnant in the central and western regions. This uneven shift is occurring due to differences in fuel price costs, renewable energy targets, infrastructure constraints, historical approach to regulation, and other factors across states.

  5. Thermodynamic DFT analysis of natural gas.

    Science.gov (United States)

    Neto, Abel F G; Huda, Muhammad N; Marques, Francisco C; Borges, Rosivaldo S; Neto, Antonio M J C

    2017-08-01

    Density functional theory was performed for thermodynamic predictions on natural gas, whose B3LYP/6-311++G(d,p), B3LYP/6-31+G(d), CBS-QB3, G3, and G4 methods were applied. Additionally, we carried out thermodynamic predictions using G3/G4 averaged. The calculations were performed for each major component of seven kinds of natural gas and to their respective air + natural gas mixtures at a thermal equilibrium between room temperature and the initial temperature of a combustion chamber during the injection stage. The following thermodynamic properties were obtained: internal energy, enthalpy, Gibbs free energy and entropy, which enabled us to investigate the thermal resistance of fuels. Also, we estimated an important parameter, namely, the specific heat ratio of each natural gas; this allowed us to compare the results with the empirical functions of these parameters, where the B3LYP/6-311++G(d,p) and G3/G4 methods showed better agreements. In addition, relevant information on the thermal and mechanic resistance of natural gases were investigated, as well as the standard thermodynamic properties for the combustion of natural gas. Thus, we show that density functional theory can be useful for predicting the thermodynamic properties of natural gas, enabling the production of more efficient compositions for the investigated fuels. Graphical abstract Investigation of the thermodynamic properties of natural gas through the canonical ensemble model and the density functional theory.

  6. Examining evolving performance on the Force Concept Inventory using factor analysis

    Science.gov (United States)

    Semak, M. R.; Dietz, R. D.; Pearson, R. H.; Willis, C. W.

    2017-06-01

    The application of factor analysis to the Force Concept Inventory (FCI) has proven to be problematic. Some studies have suggested that factor analysis of test results serves as a helpful tool in assessing the recognition of Newtonian concepts by students. Other work has produced at best ambiguous results. For the FCI administered as a pre- and post-test, we see factor analysis as a tool by which the changes in conceptual associations made by our students may be gauged given the evolution of their response patterns. This analysis allows us to identify and track conceptual linkages, affording us insight as to how our students have matured due to instruction. We report on our analysis of 427 pre- and post-tests. The factor models for the pre- and post-tests are explored and compared along with the methodology by which these models were fit to the data. The post-test factor pattern is more aligned with an expert's interpretation of the questions' content, as it allows for a more readily identifiable relationship between factors and physical concepts. We discuss this evolution in the context of approaching the characteristics of an expert with force concepts. Also, we find that certain test items do not significantly contribute to the pre- or post-test factor models and attempt explanations as to why this is so. This may suggest that such questions may not be effective in probing the conceptual understanding of our students.

  7. Multiparameter Analysis of Gas Transport Phenomena in Shale Gas Reservoirs: Apparent Permeability Characterization.

    Science.gov (United States)

    Shen, Yinghao; Pang, Yu; Shen, Ziqi; Tian, Yuanyuan; Ge, Hongkui

    2018-02-08

    The large amount of nanoscale pores in shale results in the inability to apply Darcy's law. Moreover, the gas adsorption of shale increases the complexity of pore size characterization and thus decreases the accuracy of flow regime estimation. In this study, an apparent permeability model, which describes the adsorptive gas flow behavior in shale by considering the effects of gas adsorption, stress dependence, and non-Darcy flow, is proposed. The pore size distribution, methane adsorption capacity, pore compressibility, and matrix permeability of the Barnett and Eagle Ford shales are measured in the laboratory to determine the critical parameters of gas transport phenomena. The slip coefficients, tortuosity, and surface diffusivity are predicted via the regression analysis of the permeability data. The results indicate that the apparent permeability model, which considers second-order gas slippage, Knudsen diffusion, and surface diffusion, could describe the gas flow behavior in the transition flow regime for nanoporous shale. Second-order gas slippage and surface diffusion play key roles in the gas flow in nanopores for Knudsen numbers ranging from 0.18 to 0.5. Therefore, the gas adsorption and non-Darcy flow effects, which involve gas slippage, Knudsen diffusion, and surface diffusion, are indispensable parameters of the permeability model for shale.

  8. Attachment B: URS Shale Gas Emissions Analysis

    Science.gov (United States)

    This data was provided in response to a request by ANGA for actual current data that could be compared to EPA's assumptions used in the newly proposed Oil and Natural Gas Air Pollution Standards, Subpart quad 0

  9. Iron-rich Carbonates as the Potential Source of Evolved CO2 Detected by the Sample Analysis at Mars (SAM) instrument in Gale Crater.

    Science.gov (United States)

    Sutter, B.; Heil, E.; Rampe, E. B.; Morris, R. V.; Ming, D. W.; Archer, P. D., Jr.; Eigenbrode, J. L.; Franz, H. B.; Glavin, D. P.; McAdam, A.; Navarro-Gonzalez, R.; Mahaffy, P. R.; Stern, J. C.; Mertzman, S. A.

    2015-12-01

    The Sample Analysis at Mars (SAM) instrument detected at least 4 distinct CO2 release during the pyrolysis of a sample scooped from the Rocknest (RN) eolian deposit. The highest peak CO2 release temperature (478-502°C) has been attributed to either a Fe-rich carbonate or nano-phase Mg-carbonate. The objective of this experimental study was to evaluate the thermal evolved gas analysis (T/EGA) characteristics of a series of terrestrial Fe-rich carbonates under analog SAM operating conditions to compare with the RN CO2 releases. Natural Fe-rich carbonates (Gale Crater and elsewhere on Mars (e.g., Gusev Crater, Meridiani) suggests that up to 1 wt. % Fe-rich carbonate may occur throughout the Gale Crater region and could be widespread on Mars. The Rocknest Fe-carbonate may have formed from the interaction of reduced Fe phases (e.g., Fe2+ bearing olivine) with atmospheric CO2 and transient water. Alternatively, the Rocknest Fe-carbonate could be derived by eolian processes that have eroded distally exposed deep crustal material that possesses Fe-carbonate that may have formed through metamorphic and/or metasomatic processes.

  10. Iron-Rich Carbonates as the Potential Source of Evolved CO2 Detected by the Sample Analysis at Mars (SAM) Instrument in Gale Crater

    Science.gov (United States)

    Sutter, B.; Heil, E.; Rampe, E. B.; Morris, R. V.; Ming, D. W.; Archer, P. D.; Eigenbrode, J. L.; Franz, H. B.; Glavin, D. P.; McAdam, A. C.; hide

    2015-01-01

    The Sample Analysis at Mars (SAM) instrument detected at least 4 distinct CO2 release during the pyrolysis of a sample scooped from the Rocknest (RN) eolian deposit. The highest peak CO2 release temperature (478-502 C) has been attributed to either a Fe-rich carbonate or nano-phase Mg-carbonate. The objective of this experimental study was to evaluate the thermal evolved gas analysis (T/EGA) characteristics of a series of terrestrial Fe-rich carbonates under analog SAM operating conditions to compare with the RN CO2 releases. Natural Fe-rich carbonates (Gale Crater and elsewhere on Mars (e.g., Gusev Crater, Meridiani) suggests that up to 1 wt. % Fe-rich carbonate may occur throughout the Gale Crater region and could be widespread on Mars. The Rocknest Fe-carbonate may have formed from the interaction of reduced Fe phases (e.g., Fe2+ bearing olivine) with atmospheric CO2 and transient water. Alternatively, the Rocknest Fe-carbonate could be derived by eolian processes that have eroded distally exposed deep crustal material that possesses Fe-carbonate that may have formed through metamorphic and/or metasomatic processes.

  11. Analysis of natural gas supply strategies at Fort Drum

    Energy Technology Data Exchange (ETDEWEB)

    Stucky, D.J.; Shankle, S.A.; Anderson, D.M.

    1992-07-01

    This analysis investigates strategies for Fort Drum to acquire a reliable natural gas supply while reducing its gas supply costs. The purpose of this study is to recommend an optimal supply mix based on the life-cycle costs of each strategy analyzed. In particular, this study is intended to provide initial guidance as to whether or not the building and operating of a propane-air mixing station is a feasible alternative to the current gas acquisition strategy. The analysis proceeded by defining the components of supply (gas purchase, gas transport, supplemental fuel supply); identifying alternative options for each supply component; constructing gas supply strategies from different combinations of the options available for each supply component and calculating the life-cycle costs of each supply strategy under a set of different scenarios reflecting the uncertainty of future events.

  12. Modular Analytical Multicomponent Analysis in Gas Sensor Aarrays

    OpenAIRE

    Theodor Doll; Gerhard Müller; Simon Ahlers; Olaf Kiesewetter; Rüdiger Traute; Ali Chaiyboun

    2006-01-01

    A multi-sensor system is a chemical sensor system which quantitatively and qualitatively records gases with a combination of cross-sensitive gas sensor arrays and pattern recognition software. This paper addresses the issue of data analysis for identification of gases in a gas sensor array. We introduce a software tool for gas sensor array configuration and simulation. It concerns thereby about a modular software package for the acquisition of data of different sensors. A signal evaluation al...

  13. Preanalytical considerations in blood gas analysis

    Science.gov (United States)

    Baird, Geoffrey

    2013-01-01

    Blood gas testing is a commonly ordered test in hospital settings, where the results almost always have the potential to dictate an immediate or urgent response. The preanalytical steps in testing, from choosing the correct tests to ensuring the specimen is introduced into the instrument correctly, must be perfectly coordinated to ensure that the patient receives appropriate and timely therapy in response to the analytical results. While many of the preanalytical steps in blood gas testing are common to all laboratory tests, such as accurate specimen labeling, some are unique to this testing because of the physicochemical properties of the analytes being measured. The common sources of preanalytical variation in blood gas testing are reviewed here. PMID:23457763

  14. Network analysis of breast cancer progression and reversal using a tree-evolving network algorithm.

    Directory of Open Access Journals (Sweden)

    Ankur P Parikh

    2014-07-01

    Full Text Available The HMT3522 progression series of human breast cells have been used to discover how tissue architecture, microenvironment and signaling molecules affect breast cell growth and behaviors. However, much remains to be elucidated about malignant and phenotypic reversion behaviors of the HMT3522-T4-2 cells of this series. We employed a "pan-cell-state" strategy, and analyzed jointly microarray profiles obtained from different state-specific cell populations from this progression and reversion model of the breast cells using a tree-lineage multi-network inference algorithm, Treegl. We found that different breast cell states contain distinct gene networks. The network specific to non-malignant HMT3522-S1 cells is dominated by genes involved in normal processes, whereas the T4-2-specific network is enriched with cancer-related genes. The networks specific to various conditions of the reverted T4-2 cells are enriched with pathways suggestive of compensatory effects, consistent with clinical data showing patient resistance to anticancer drugs. We validated the findings using an external dataset, and showed that aberrant expression values of certain hubs in the identified networks are associated with poor clinical outcomes. Thus, analysis of various reversion conditions (including non-reverted of HMT3522 cells using Treegl can be a good model system to study drug effects on breast cancer.

  15. Gas chromatographic and mass spectrometric analysis of ...

    Indian Academy of Sciences (India)

    Unknown

    anabolic steroids in urine collected from orally administered humans. Microanalysis of conjugated steroids by gas chromatography and mass spectrometry (GC/MS) has been carried out. Following oral administration three major metabolites of anabolic steroid drugs have been detected and partially characterized. The six ...

  16. Modular Analytical Multicomponent Analysis in Gas Sensor Aarrays

    Science.gov (United States)

    Chaiyboun, Ali; Traute, Rüdiger; Kiesewetter, Olaf; Ahlers, Simon; Müller, Gerhard; Doll, Theodor

    2006-01-01

    A multi-sensor system is a chemical sensor system which quantitatively and qualitatively records gases with a combination of cross-sensitive gas sensor arrays and pattern recognition software. This paper addresses the issue of data analysis for identification of gases in a gas sensor array. We introduce a software tool for gas sensor array configuration and simulation. It concerns thereby about a modular software package for the acquisition of data of different sensors. A signal evaluation algorithm referred to as matrix method was used specifically for the software tool. This matrix method computes the gas concentrations from the signals of a sensor array. The software tool was used for the simulation of an array of five sensors to determine gas concentration of CH4, NH3, H2, CO and C2H5OH. The results of the present simulated sensor array indicate that the software tool is capable of the following: (a) identify a gas independently of its concentration; (b) estimate the concentration of the gas, even if the system was not previously exposed to this concentration; (c) tell when a gas concentration exceeds a certain value. A gas sensor data base was build for the configuration of the software. With the data base one can create, generate and manage scenarios and source files for the simulation. With the gas sensor data base and the simulation software an on-line Web-based version was developed, with which the user can configure and simulate sensor arrays on-line.

  17. THERMOECONOMIC ANALYSIS AND OPTIMIZATION OF GAS TURBINE POWER PLANT

    OpenAIRE

    Siahaya, Yusuf

    2009-01-01

    A gas turbine power plant, which will be located in Jakarta, will analyzed with the aid of exergy, exergoeconomics and optimization. An exergy analysis identifies the real thermodynacs inefficiency due to irreversibility destroyed within a gas turbine power plant system. An exergoeconomics or thermodynamic analysis consists of an exergy, an economic, an exergy costing, an exergoeconomic, and an exergoeconomic optimization aims at minimizing the thermodynamic inefficiencies (exergy...

  18. Blood gas analysis as a determinant of occupationally related disability

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, W.K.; Zaldivar, G.L. (Univ. of Western Ontario, London, Ontario (Canada))

    1990-05-01

    Arterial blood gas analysis is one of the criteria used by the Department of Labor to award total and permanent disability for coal workers' pneumoconiosis (Black Lung). We have observed that Black Lung claimants often undergo several blood gas analyses with widely differing results that sometimes range from complete normality to life-threatening hypoxemia in the same subject. We concluded that blood gas analysis in occupationally related disability determination is unreliable, in that quality control and instrumentation are variable; that severe hypoxemia is rare in coal workers' pneumoconiosis; and that such hypoxemia is nonspecific and correlates poorly with breathlessness.

  19. In situ gas analysis during the growth of hexagonal boron nitride from ammonia borane

    Science.gov (United States)

    Wood, Grace E.; Laker, Zachary P. L.; Marsden, Alexander J.; Bell, Gavin R.; Wilson, Neil R.

    2017-11-01

    Ammonia borane (NH3 :BH3 ) is commonly used as a stoichiometric source of nitrogen and boron for the growth of hexagonal boron nitride (h-BN) by chemical vapour deposition (CVD). We use in situ gas analysis by mass spectrometry to investigate the active chemical components that evolve when an ammonia borane source is heated, and study how these components change after flowing through the CVD growth furnace. This also gives insight into the catalytic effect of copper substrates used for CVD growth of h-BN. We find that in vacuum, even at 40 °C, gaseous amino borane and polyaminoborane fragments are evolved from the solid source; as the temperature of the ammonia borane source increases, the amount of all components increases but proportionally more of the higher mass components are present. Gas phase reactions change the gas composition after flowing through the CVD growth furnace, depending on the temperature of the growth furnace, with increased dehydrogenation at higher furnace temperatures. Further reactions are catalysed by the copper substrate, with decomposition of the higher mass components evident at furnace temperatures > 900 °C. Direct comparison with CVD h-BN growth suggests that the lower mass components produced by lower ammonia borane source temperatures are preferred for larger island sizes and that furnace temperatures higher than 900 °C are required in order to initiate the catalytic effects of the copper substrate. In situ gas analysis thus gives new insight into the CVD growth of h-BN, and similar methodology could be used to optimise and understand the growth of other two dimensional materials.

  20. Modular Analytical Multicomponent Analysis in Gas Sensor Aarrays

    Directory of Open Access Journals (Sweden)

    Theodor Doll

    2006-04-01

    Full Text Available A multi-sensor system is a chemical sensor system which quantitatively andqualitatively records gases with a combination of cross-sensitive gas sensor arrays andpattern recognition software. This paper addresses the issue of data analysis foridentification of gases in a gas sensor array. We introduce a software tool for gas sensorarray configuration and simulation. It concerns thereby about a modular software packagefor the acquisition of data of different sensors. A signal evaluation algorithm referred to asmatrix method was used specifically for the software tool. This matrix method computes thegas concentrations from the signals of a sensor array. The software tool was used for thesimulation of an array of five sensors to determine gas concentration of CH4, NH3, H2, COand C2H5OH. The results of the present simulated sensor array indicate that the softwaretool is capable of the following: (a identify a gas independently of its concentration; (bestimate the concentration of the gas, even if the system was not previously exposed to thisconcentration; (c tell when a gas concentration exceeds a certain value. A gas sensor database was build for the configuration of the software. With the data base one can create,generate and manage scenarios and source files for the simulation. With the gas sensor database and the simulation software an on-line Web-based version was developed, with whichthe user can configure and simulate sensor arrays on-line.

  1. Gas Turbine Design & Analysis Tool: Turbomachinery Components.

    OpenAIRE

    Garcia Soto, David

    2012-01-01

    Este proyecto se centra en la creación de un programa el cual ha de ser una herramienta de ayuda en el diseño y simulación de aplicaciones de motores de turbina de gas, permitiendo al usuario realizar los cálculos necesarios para poder implementar posteriormente los resultados en sus diseños. Por ello, dicha herramienta debe ser versátil y permitir trabajar tanto con un solo módulo como con diversos acoplados según las necesidades del usuario. Además el hecho de modularizar permite acotar y r...

  2. Correlation between arterial blood gas analysis and peripheral blood gas analysis in acid-base unbalance state

    OpenAIRE

    Lee Kim, Hyun; Ho Ryu, Hyun

    2012-01-01

    Acid-base unbalance is most common problem in severe ill patient, especially in condition of abnormal renal function state. Acid-base unbalances are respiratory acidosis, respiratory alkalosis, metabolic acidosis, and metabolic alkalosis. Metabolic acidosis is frequently appeared in clinical state. Arterial blood gas analysis is considered as a basic test to the intensive care unit patient and emergency state. Recently some researches were done, comparing with arterial blood gas analysis and ...

  3. Signal Analysis of Gas Tungsten Arc Welds

    Science.gov (United States)

    Eagar, T. W.

    1985-01-01

    Gas tungsten arc welding is a process in which the input parameters such as current, voltage and travel speed, can be easily controlled and/or monitored. However, weld quality is not solely a function of these parameters. An adaptive method of observing weld quality is desired to improve weld quality assurance. The use of dynamic electrical properties of the welding arc as a weld quality monitor was studied. The electrical properties of the arc are characterized by the current voltage transfer function. The hardware and software necessary to collect the data at a maximum rate of 45 kHz and to allow the off-line processing of this data are tested. The optimum input current waveform is determined. Bead-on-plate welds to observe such characteristics of the weld as the fundamental frequency of the puddle are studied. Future work is planned to observe changes of the arc response with changes in joint geometry, base metal chemistry, and shielding gas composition are discussed.

  4. Suitability of selected free-gas and dissolved-gas sampling containers for carbon isotopic analysis.

    Science.gov (United States)

    Eby, P; Gibson, J J; Yi, Y

    2015-07-15

    Storage trials were conducted for 2 to 3 months using a hydrocarbon and carbon dioxide gas mixture with known carbon isotopic composition to simulate typical hold times for gas samples prior to isotopic analysis. A range of containers (both pierced and unpierced) was periodically sampled to test for δ(13)C isotopic fractionation. Seventeen containers were tested for free-gas storage (20°C, 1 atm pressure) and 7 containers were tested for dissolved-gas storage, the latter prepared by bubbling free gas through tap water until saturated (20°C, 1 atm) and then preserved to avoid biological activity by acidifying to pH 2 with phosphoric acid and stored in the dark at 5°C. Samples were extracted using valves or by piercing septa, and then introduced into an isotope ratio mass spectrometer for compound-specific δ(13)C measurements. For free gas, stainless steel canisters and crimp-top glass serum bottles with butyl septa were most effective at preventing isotopic fractionation (pierced and unpierced), whereas silicone and PTFE-butyl septa allowed significant isotopic fractionation. FlexFoil and Tedlar bags were found to be effective only for storage of up to 1 month. For dissolved gas, crimp-top glass serum bottles with butyl septa were again effective, whereas silicone and PTFE-butyl were not. FlexFoil bags were reliable for up to 2 months. Our results suggest a range of preferred containers as well as several that did not perform very well for isotopic analysis. Overall, the results help establish better QA/QC procedures to avoid isotopic fractionation when storing environmental gas samples. Recommended containers for air transportation include steel canisters and glass serum bottles with butyl septa (pierced and unpierced). Copyright © 2015 John Wiley & Sons, Ltd.

  5. Development of a gas systems analysis model (GSAM)

    Energy Technology Data Exchange (ETDEWEB)

    Godec, M.L. [IFC Resources Inc., Fairfax, VA (United States)

    1995-04-01

    The objectives of developing a Gas Systems Analysis Model (GSAM) are to create a comprehensive, non-proprietary, PC based model of domestic gas industry activity. The system is capable of assessing the impacts of various changes in the natural gas system within North America. The individual and collective impacts due to changes in technology and economic conditions are explicitly modeled in GSAM. Major gas resources are all modeled, including conventional, tight, Devonian Shale, coalbed methane, and low-quality gas sources. The modeling system asseses all key components of the gas industry, including available resources, exploration, drilling, completion, production, and processing practices, both for now and in the future. The model similarly assesses the distribution, storage, and utilization of natural gas in a dynamic market-based analytical structure. GSAM is designed to provide METC managers with a tool to project the impacts of future research, development, and demonstration (RD&D) benefits in order to determine priorities in a rapidly changing, market-driven gas industry.

  6. Disgust: Evolved function and structure

    NARCIS (Netherlands)

    Tybur, J.M.; Lieberman, D.; Kurzban, R.; DeScioli, P.

    2013-01-01

    Interest in and research on disgust has surged over the past few decades. The field, however, still lacks a coherent theoretical framework for understanding the evolved function or functions of disgust. Here we present such a framework, emphasizing 2 levels of analysis: that of evolved function and

  7. Cost analysis of NOx control alternatives for stationary gas turbines

    Energy Technology Data Exchange (ETDEWEB)

    Bill Major

    1999-11-05

    The use of stationary gas turbines for power generation has been growing rapidly with continuing trends predicted well into the future. Factors that are contributing to this growth include advances in turbine technology, operating and siting flexibility and low capital cost. Restructuring of the electric utility industry will provide new opportunities for on-site generation. In a competitive market, it maybe more cost effective to install small distributed generation units (like gas turbines) within the grid rather than constructing large power plants in remote locations with extensive transmission and distribution systems. For the customer, on-site generation will provide added reliability and leverage over the cost of purchased power One of the key issues that is addressed in virtually every gas turbine application is emissions, particularly NO{sub x} emissions. Decades of research and development have significantly reduced the NO{sub x} levels emitted from gas turbines from uncontrolled levels. Emission control technologies are continuing to evolve with older technologies being gradually phased-out while new technologies are being developed and commercialized. The objective of this study is to determine and compare the cost of NO{sub x} control technologies for three size ranges of stationary gas turbines: 5 MW, 25 MW and 150 MW. The purpose of the comparison is to evaluate the cost effectiveness and impact of each control technology as a function of turbine size. The NO{sub x} control technologies evaluated in this study include: Lean premix combustion, also known as dry low NO{sub x} (DLN) combustion; Catalytic combustion; Water/steam injection; Selective catalytic reduction (SCR)--low temperature, conventional, high temperature; and SCONO{sub x}{trademark}.

  8. Systems Analysis of In-Space Manufacturing Applications for the International Space Station and the Evolvable Mars Campaign

    Science.gov (United States)

    Owens, Andrew C.; De Weck, Olivier L.

    2016-01-01

    Maintenance logistics support is a significant challenge for extended human operations in space, especially for missions beyond Low Earth Orbit (LEO). For missions to Mars (such as NASA's Evolvable Mars Campaign (EMC)), where timely resupply or abort in the event of emergency will not be possible, maintenance logistics mass is directly linked to the Probability of Loss of Crew (P(LoC)), and the cost of driving down risk is an exponential increase in mass requirements. The logistics support strategies that have maintained human operations in LEO will not be effective for these deep space missions. In-Space Manufacturing (ISM) is a promising technological solution that could reduce logistics requirements, mitigate risks, and augment operational capabilities, enabling Earth- independent human spaceflight. This paper reviews maintenance logistics challenges for spaceflight operations in LEO and beyond, and presents a summary of selected results from a systems analysis of potential ISM applications for the ISS and EMC. A quantitative modeling framework and sample assessment of maintenance logistics and risk reduction potential of this new technology is also presented and discussed.

  9. Engineering analysis of biomass gasifier product gas cleaning technology

    Energy Technology Data Exchange (ETDEWEB)

    Baker, E.G.; Brown, M.D.; Moore, R.H.; Mudge, L.K.; Elliott, D.C.

    1986-08-01

    For biomass gasification to make a significant contribution to the energy picture in the next decade, emphasis must be placed on the generation of clean, pollutant-free gas products. This reports attempts to quantify levels of particulated, tars, oils, and various other pollutants generated by biomass gasifiers of all types. End uses for biomass gases and appropriate gas cleaning technologies are examined. Complete systems analysis is used to predit the performance of various gasifier/gas cleanup/end use combinations. Further research needs are identified. 128 refs., 20 figs., 19 tabs.

  10. EVOLVE 2014 International Conference

    CERN Document Server

    Tantar, Emilia; Sun, Jian-Qiao; Zhang, Wei; Ding, Qian; Schütze, Oliver; Emmerich, Michael; Legrand, Pierrick; Moral, Pierre; Coello, Carlos

    2014-01-01

    This volume encloses research articles that were presented at the EVOLVE 2014 International Conference in Beijing, China, July 1–4, 2014.The book gathers contributions that emerged from the conference tracks, ranging from probability to set oriented numerics and evolutionary computation; all complemented by the bridging purpose of the conference, e.g. Complex Networks and Landscape Analysis, or by the more application oriented perspective. The novelty of the volume, when considering the EVOLVE series, comes from targeting also the practitioner’s view. This is supported by the Machine Learning Applied to Networks and Practical Aspects of Evolutionary Algorithms tracks, providing surveys on new application areas, as in the networking area and useful insights in the development of evolutionary techniques, from a practitioner’s perspective. Complementary to these directions, the conference tracks supporting the volume, follow on the individual advancements of the subareas constituting the scope of the confe...

  11. Thermodynamic analysis of steam-injected advanced gas turbine cycles

    Science.gov (United States)

    Pandey, Devendra; Bade, Mukund H.

    2017-12-01

    This paper deals with thermodynamic analysis of steam-injected gas turbine (STIGT) cycle. To analyse the thermodynamic performance of steam-injected gas turbine (STIGT) cycles, a methodology based on pinch analysis is proposed. This graphical methodology is a systematic approach proposed for a selection of gas turbine with steam injection. The developed graphs are useful for selection of steam-injected gas turbine (STIGT) for optimal operation of it and helps designer to take appropriate decision. The selection of steam-injected gas turbine (STIGT) cycle can be done either at minimum steam ratio (ratio of mass flow rate of steam to air) with maximum efficiency or at maximum steam ratio with maximum net work conditions based on the objective of plants designer. Operating the steam injection based advanced gas turbine plant at minimum steam ratio improves efficiency, resulting in reduction of pollution caused by the emission of flue gases. On the other hand, operating plant at maximum steam ratio can result in maximum work output and hence higher available power.

  12. Analysis of the Energy Balance of Shale Gas Development

    Directory of Open Access Journals (Sweden)

    Hiroaki Yaritani

    2014-04-01

    Full Text Available Interest has rapidly grown in the use of unconventional resources to compensate for depletion of conventional hydrocarbon resources (“easy hydrocarbon” that are produced at relatively low cost from oil and gas fields with large proven reserves. When one wants to ensure the prospects for development of unconventional resources that are potentially vast in terms of their energy potential, it is essential to determine the quality of that energy. Here we consider the development of shale gas, an unconventional energy resource of particularly strong interest of late, through analysis of its energy return on investment (EROI, a key indicator for qualitative assessment of energy resources. We used a Monte Carlo approach for the carbon footprint of U.S. operations in shale gas development to estimate expected ranges of EROI values by incorporating parameter variability. We obtained an EROI of between 13 and 23, with a mean of approximately 17 at the start of the pipeline. When we incorporated all the costs required to bring shale gas to the consumer, the mean value of EROI drops from about 17 at the start of the pipeline to 12 when delivered to the consumer. The shale gas EROI values estimated in the present study are in the initial stage of shale gas exploitation where the quality of that resource may be considerably higher than the mean and thus the careful and continuous investigation of change in EROI is needed, especially as production moves off the initial “sweet spots”.

  13. An industrial FT-IR process gas analyzer for stack gas cems analysis

    Energy Technology Data Exchange (ETDEWEB)

    Welch, G.M. [American instruments, Anacortes, WA (United States); Herman, B.E. [Applied Automation/Hartmann & Braun, Bartlesville, OK (United States)

    1995-12-31

    This paper describes utilizing Fourier Transform Infrared (FT-IR) technology to meet and exceed EPA requirements to Continuously Monitor Carbon Monoxide (CO) and Sulfur Dioxide (SO){sub 2} in an oil refinery. The application consists of Continuous Emission Monitoring (CEMS) of two stacks from a Fluid Catalytic Cracking unit (FCCU). The discussion will follow the project from initial specifications, installation, start-up, certification results (RATA, 7 day drift), Cylinder Gas Audit (CGA) and the required maintenance. FT-IR is a powerful analytical tool suitable for measurement of stack component gases required to meet CEMS regulations, and allows simultaneous multi-component analysis of complex stack gas streams with a continuous sample stream flow through the measurement cell. The Michelson Interferometer in a unique {open_quotes}Wishbone{close_quotes} design and with a special alignment control enables standardized configuration of the analyzer for flue gas analysis. Normal stack gas pollutants: NO{sub x}, SO{sub 2}, and CO; as well as water soluble pollutants such as NH{sub 3} and HCI may be accurately determined and reported even in the presence of 0-31 Vol % water vapor concentrations (hot and wet). This FT-IR analyzer has been operating with EPA Certification in an oil refinery environment since September 1994.

  14. Using Single Drop Microextraction for Headspace Analysis with Gas Chromatography

    Science.gov (United States)

    Riccio, Daniel; Wood, Derrick C.; Miller, James M.

    2008-01-01

    Headspace (HS) gas chromatography (GC) is commonly used to analyze samples that contain non-volatiles. In 1996, a new sampling technique called single drop microextraction, SDME, was introduced, and in 2001 it was applied to HS analysis. It is a simple technique that uses equipment normally found in the undergraduate laboratory, making it ideal…

  15. Gas Chromatographic-Mass Spectrometric Analysis of Essential Oil ...

    African Journals Online (AJOL)

    Purpose: To analyze the essential oil composition of the flower of Jasminum officinale L. var. grandifloroum L. (Jasminum grandiflorum) by gas chromatography-mass spectrometry (GC-MS). Methods: The optimum GC-MS conditions used for the analysis were 250 oC inlet temperature, 150 oC MSD detector temperature, ...

  16. Delayed cord clamping and cord gas analysis at birth.

    Science.gov (United States)

    Xodo, Serena; Xodo, Luigi; Berghella, Vincenzo

    2018-01-01

    Delayed cord clamping for at least 60 s in both term and preterm babies is a major recent change in clinical care. Delayed cord clamping has several effects on other possible interventions. One of these is the effect of delayed cord clamping on umbilical artery gas analysis. When indicated, umbilical artery gas analysis can safely be done either with early cord clamping or, probably most of the times it is necessary, during delayed cord clamping with the cord still unclamped. Paired blood samples (one from the umbilical artery and one from the umbilical vein) can be taken from the pulsating and unclamped cord, immediately after birth, during delayed cord clamping, without any effect on either the accuracy of umbilical artery gas analysis or the transfusion of blood through delayed cord clamping. Umbilical artery gas analysis should instead not be done after delayed cord clamping, since delayed cord clamping alters several acid-based parameters and lactate values. © 2017 Nordic Federation of Societies of Obstetrics and Gynecology.

  17. Evolvable synthetic neural system

    Science.gov (United States)

    Curtis, Steven A. (Inventor)

    2009-01-01

    An evolvable synthetic neural system includes an evolvable neural interface operably coupled to at least one neural basis function. Each neural basis function includes an evolvable neural interface operably coupled to a heuristic neural system to perform high-level functions and an autonomic neural system to perform low-level functions. In some embodiments, the evolvable synthetic neural system is operably coupled to one or more evolvable synthetic neural systems in a hierarchy.

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

    Science.gov (United States)

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

    2014-09-02

    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 (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.

  19. Static Structural and Modal Analysis of Gas Turbine Blade

    Science.gov (United States)

    Ranjan Kumar, Ravi; Pandey, K. M., Prof.

    2017-08-01

    Gas turbine is one of the most versatile items of turbo machinery nowadays. It is used in different modes such as power generation, oil and gas, process plants, aviation, domestic and related small industries. This paper is based on the problems concerning blade profile selection, material selection and turbine rotor blade vibration that seriously impact the induced stress-deformation and structural functioning of developmental gas turbine engine. In this paper for generating specific power by rotating blade at specific RPM, blade profile and material has been decided by static structural analysis. Gas turbine rotating blade RPM is decided by Modal Analysis so that the natural frequency of blade should not match with the excitation frequency. For the above blade profile has been modeled in SOLIDWORKS and analysis has been done in ANSYS WORKBENCH 14. Existing NACA6409 profile has been selected as base model and then it is modified by bending it through 72.5° and 145°. Hence these three different blade profiles have been analyzed for three different materials viz. Super Alloy X, Nimonic 80A and Inconel 625 at three different speed viz. 20000, 40000 and 60000RPM. It is found that NACA6409 with 72.5° bent gives best result for all material at all speed. Among all the material Inconel 625 gives best result. Hence Blade of Inconel 625 having 72.5° bent profile is the best combination for all RPM.

  20. Considering the Role of Natural Gas in the Deep Decarbonization of the U.S. Electricity Sector. Natural Gas and the Evolving U.S. Power Sector Monograph Series: Number 2

    Energy Technology Data Exchange (ETDEWEB)

    Cole, Wesley [National Renewable Energy Lab. (NREL), Golden, CO (United States); Beppler, Ross [National Renewable Energy Lab. (NREL), Golden, CO (United States); Zinaman, Owen [National Renewable Energy Lab. (NREL), Golden, CO (United States); Logan, Jeffrey [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-02-12

    Natural gas generation in the U.S. electricity sector has grown substantially in recent years, while the sector's carbon dioxide (CO2) emissions have generally declined. This relationship highlights the concept of natural gas as a potential enabler of a transition to a lower-carbon future. This work considers that concept by using the National Renewable Energy Laboratory (NREL) Renewable Energy Deployment System (ReEDS) model. ReEDS is a long-term capacity expansion model of the U.S. electricity sector. We examine the role of natural gas within the ReEDS modeling framework as increasingly strict carbon emission targets are imposed on the electricity sector. In addition to various natural gas price futures, we also consider scenarios that emphasize a low-carbon technology in order to better understand the role of natural gas if that low-carbon technology shows particular promise. Specifically, we consider scenarios with high amounts of energy efficiency (EE), low nuclear power costs, low renewable energy (RE) costs, and low carbon capture and storage (CCS) costs. Within these scenarios we find that requiring the electricity sector to lower CO2 emissions over time increases near-to-mid-term (through 2030) natural gas generation (see Figure 1 - left). The long-term (2050) role of natural gas generation in the electricity sector is dependent on the level of CO2 emission reduction required. Moderate reductions in long-term CO2 emissions have relatively little impact on long-term natural gas generation, while more stringent CO2 emission limits lower long-term natural gas generation (see Figure 1 - right). More stringent carbon targets also impact other generating technologies, with the scenarios considered here seeing significant decreases in coal generation, and new capacity of nuclear and renewable energy technologies over time. Figure 1 also demonstrates the role of natural gas in the context of scenarios where a specific low-carbon technology is advantaged. In

  1. Genome-Wide Analysis in Three Fusarium Pathogens Identifies Rapidly Evolving Chromosomes and Genes Associated with Pathogenicity

    Science.gov (United States)

    Sperschneider, Jana; Gardiner, Donald M.; Thatcher, Louise F.; Lyons, Rebecca; Singh, Karam B.; Manners, John M.; Taylor, Jennifer M.

    2015-01-01

    Pathogens and hosts are in an ongoing arms race and genes involved in host–pathogen interactions are likely to undergo diversifying selection. Fusarium plant pathogens have evolved diverse infection strategies, but how they interact with their hosts in the biotrophic infection stage remains puzzling. To address this, we analyzed the genomes of three Fusarium plant pathogens for genes that are under diversifying selection. We found a two-speed genome structure both on the chromosome and gene group level. Diversifying selection acts strongly on the dispensable chromosomes in Fusarium oxysporum f. sp. lycopersici and on distinct core chromosome regions in Fusarium graminearum, all of which have associations with virulence. Members of two gene groups evolve rapidly, namely those that encode proteins with an N-terminal [SG]-P-C-[KR]-P sequence motif and proteins that are conserved predominantly in pathogens. Specifically, 29 F. graminearum genes are rapidly evolving, in planta induced and encode secreted proteins, strongly pointing toward effector function. In summary, diversifying selection in Fusarium is strongly reflected as genomic footprints and can be used to predict a small gene set likely to be involved in host–pathogen interactions for experimental verification. PMID:25994930

  2. Electronic Nose Functionality for Breath Gas Analysis during Parabolic Flight

    Science.gov (United States)

    Dolch, Michael E.; Hummel, Thomas; Fetter, Viktor; Helwig, Andreas; Lenic, Joachim; Moukhamedieva, Lana; Tsarkow, Dimitrij; Chouker, Alexander; Schelling, Gustav

    2017-06-01

    The presence of humans in space represents a constant threat for their health and safety. Environmental factors such as living in a closed confinement, as well as exposure to microgravity and radiation, are associated with significant changes in bone metabolism, muscular atrophy, and altered immune response, which has impacts on human performance and possibly results in severe illness. Thus, maintaining and monitoring of crew health status has the highest priority to ensure whole mission success. With manned deep space missions to moon or mars appearing at the horizon where short-term repatriation back to earth is impossible the availability of appropriate diagnostic platforms for crew health status is urgently needed. In response to this need, the present experiment evaluated the functionality and practicability of a metal oxide based sensor system (eNose) together with a newly developed breath gas collecting device under the condition of altering acceleration. Parabolic flights were performed with an Airbus A300 ZeroG at Bordeaux, France. Ambient air and exhaled breath of five healthy volunteers was analyzed during steady state flight and parabolic flight maneuvres. All volunteers completed the study, the breath gas collecting device valves worked appropriately, and breathing through the collecting device was easy and did not induce discomfort. During breath gas measurements, significant changes in metal oxide sensors, mainly sensitive to aromatic and sulphur containing compounds, were observed with alternating conditions of acceleration. Similarly, metal oxide sensors showed significant changes in all sensors during ambient air measurements. The eNose as well as the newly developed breath gas collecting device, showed appropriate functionality and practicability during alternating conditions of acceleration which is a prerequisite for the intended use of the eNose aboard the International Space Station (ISS) for breath gas analysis and crew health status

  3. Optimization of the Heating Element in a Gas-Gas Heater Using an Integrated Analysis Model

    Directory of Open Access Journals (Sweden)

    Young Mun Lee

    2017-11-01

    Full Text Available Gas-gas heaters (GGHs are used to reheat gases through desulfurization in coal-fired power plants to reduce low-temperature corrosion and white smoke. Wrinkled heating elements are installed inside the GGH to perform effective heat exchange. An optimization study of the heating element shape was conducted to reduce the differential pressure effectively and improve performance. An integrated analysis model was applied. Based on actual operational data, a computational fluid dynamic analysis was conducted on the L-type heating element and GGH system. The experiments applied the optimal latin hypercube sampling method, and numerical analysis was performed for each sample. Based on the response surface, the result of the sample was optimized through the pointer algorithm. For the integrated analysis model, validation was performed by comparison with the actual operational data, and the thermal-fluid characteristics of the heating element and GGH system were analyzed to set three parameters: plate angle, undulated angle, and pitch 1. From the optimization result, increases in the undulated angle and pitch 1 reduce the pressure drop by widening the heating element cross section. By increasing the plate angle, the heat transfer area is secured and the reduced heat transfer coefficient is compensated, improving the GGH performance.

  4. Integrated Analysis of Optimizing Tubing Material Selection for Gas Wells

    OpenAIRE

    Bonar Tua Halomoan Marbun; Samuel Z. Sinaga; Gde V.I. Arimbawa; Aristya P. Pamungkas; Aldiano F. Hardama; Ricko Rizkiaputra

    2015-01-01

    Corrosion in production tubing strings is seen as a challenging problem in gas wells containing carbon dioxideand hydrogen sulfide. This paper presents a new comprehensive method of corrosion rate calculation with integrated study of reservoir condition, nodal analysis of the well, and well trajectory, which could also have an effect due to the possibility of different flow regimes of the production fluid. This method is applicable to evaluate and predict the performance of selected tubing s...

  5. The Physics Analysis of a Gas Attenuator with Argon as a Working Gas

    Energy Technology Data Exchange (ETDEWEB)

    Ryutov, D D; Bionta, R M; McKernan, M A; Shen, S; Trent, J W

    2005-12-19

    A gas attenuator is an important element of the LCLS facility. The attenuator has to operate in a broad range of x-ray energies, provide attenuation coefficient between 1 and 10{sup 4} with the accuracy of 1% and, at the same time, be reliable and allow for many months of un-interrupted operation. A detailed design study of the attenuator based on the use of nitrogen as a working gas has been recently carried out by S. Shen et al [1]. In this note we assess the features of the attenuator based on the use of argon. We concentrate on the physics issues; the design features will probably be not that different from the aforementioned nitrogen attenuator. Although specific results obtained in our note pertain to argon, the general framework (and many equations obtained) are applicable also to the nitrogen attenuator. In the past, an analysis of the attenuator based on the use of a noble gas has already been carried out [2]. This analysis was performed for an extremely stringent set of specifications. In particular, a very large diameter for the unobstructed x-ray beam was set (1 cm) to accommodate the spontaneous radiation; the attenuator was supposed to cover the whole range of energies of the coherent radiation, from 800 eV to 8000 eV; the maximum attenuation was set at the level of 10{sup 4}; the use of solid attenuators was not allowed, as well as the use of rotating shutters. The need to reach a sufficient absorption at the high-energy end of the spectrum predetermined the choice of Xe as the working gas (in order to have a reasonable absorption at a not-too-high pressure). A sophisticated differential pumping system that included a Penning-type ion pump was suggested in order to minimize the gas leak into the undulator/accelerator part of the facility. A high cost of xenon meant also that an efficient (and expensive) gas-recovery system would have to be installed. The main parameter that determined the high cost and the complexity of the system was a large radius

  6. Undisplayed Bicarbonate ion Concentration in Arterial Blood Gas Analysis.

    Science.gov (United States)

    Sathe, Aditya Balakrishna; Bhalkar, Manjiri Shashank

    2013-12-01

    Blood bicarbonate ion concentration (BcHCO3 (-)) is a vital parameter in the management of acid base disorders. In an arterial blood gas (ABG) analyzer, the BcHCO3 (-) is calculated from the values of pH and pCO2. We received four samples in a span of one year, from December 2011 to November 2012 for arterial blood gas analysis, in which the BcHCO3 (-) was not displayed by the blood gas analyzer. Based on the information available in literature, the formula for calculating the BcHCO3 (-) from pH and pCO2 was obtained and BcHCO3 (-) was calculated in all four samples mentioned above. An attempt was made to establish a clinical correlation between laboratory and clinical data of these patients. All these values of BcHCO3 (-) were above the maximum display limit of our blood gas analyzer, which was 60 mmol/L and hence, they were not displayed. All four patients had chronic respiratory disease and they were taking furosemide and / or dexamethasone. High values of BcHCO3 (-) , sometimes falling beyond the display range of the ABG analyzer, could be observed in patients of chronic respiratory disease, treated with drugs like furosemide and dexamethasone, that result in bicarbonate retention.

  7. New method of respiratory gas analysis: light spectrometer.

    Science.gov (United States)

    Fraser, R B; Turney, S Z

    1985-09-01

    A multigas concentration analyzer particularly suited for respiratory gas analysis has been developed using a new principle based on the measurement of the intensity of light emitted by excited atoms or ions in a direct current glow discharge. This glow discharge spectral emission gas analyzer (GDSEA), or light spectrometer, simultaneously measures O2, N2, CO2, He, and N2O gas concentrations with a 0-90% response time of 100 ms and a sample rate of less than 20 ml/min in a short gas sample line configuration. Mole accuracy and resolution of the GDSEA using a short sample line were determined in the laboratory to be +/- 0.15 to +/- 0.7% and 0.02-0.05%, respectively. In the clinical setting a comparative evaluation was made with a mass spectrometer in a long sample line, computerized, multibed, respiratory monitoring system. Results indicate a close agreement between the two instruments with differences in mixed inspiratory or expiratory O2 and CO2 concentrations of less than 2% and of derived variables, such as O2 consumption, CO2 production, and respiratory exchange ratio, of less than 5%.

  8. Mass spectrometric analysis of evolved CO2 during 9.6-μm CO2 irradiation of dental enamel

    Science.gov (United States)

    Xie, John; Fried, Daniel

    2002-06-01

    Carbon dioxide laser irradiation induces chemical changes in dental hard tissues including, dehydration, decomposition, disproportionation, and vaporization. Such changes can lead to either an increase or decrease in susceptibility to acid dissolution and adversely affect the bond strength to restorative materials. The objective of this study was to measure the evolved molecular species produced during laser irradiation. Samples of bovine enamel were irradiated by a 9.6 micrometers TEA CO2 laser in a vacuum chamber connected to a quadruple mass spectrometer. At irradiation intensities above 0.37 J/cm2 an increase in evolved CO2 and H2O were detected indicative of thermal decomposition of the mineral phase. The respective ion yields changed markedly with increasing number of laser pulses suggesting that the decomposition was complete after less than ten laser pulses at irradiation intensities from 0.4 to 0.8 J/cm2. Above irradiation intensities of 1.0 J/cm2 there is continual emission after 50 laser pulses indicative of vaporization and material removal. At higher ablative fluence, higher mass species were detected due to the ejection of hydroxyapatite. This study demonstrates that mass spectroscopy can be used to directly probe laser induced physical and chemical changes in dental hard tissue during laser ablation.

  9. Minimal residual disease detection and evolved IGH clones analysis in acute B lymphoblastic leukemia using IGH deep sequencing

    Directory of Open Access Journals (Sweden)

    Jinghua Wu

    2016-10-01

    Full Text Available Acute B lymphoblastic leukemia (B-ALL is one of most common types of childhood cancer worldwide and chemotherapy is the main treatment approach. Despite good response rates to chemotherapy regiments, many patients eventually relapse and minimal residual disease (MRD is the leading risk factor for relapse. The evolution of leukemic clones during disease development and treatment may have clinical significance. In this study, we performed immunoglobulin heavy chain (IGH repertoire high throughput sequencing (HTS on the diagnostic and post-treatment samples of 51 pediatric B-ALL patients. We identified leukemic IGH clones in 92.2% of the diagnostic samples and nearly half of the patients were polyclonal. About 1/3 of the leukemic clones have correct open reading frame (ORF in the complementarity determining region 3 (CDR3 of IGH, which demonstrates that the leukemic B cells were in the early developmental stage. We also demonstrated the higher sensitivity of HTS in MRD detection and investigated the clinical value of using peripheral blood in MRD detection and monitoring the clonal IGH evolution. In addition, we found leukemic clones were extensively undergoing continuous clonal IGH evolution by variable gene replacement. Dynamic frequency change and newly emerged evolved IGH clones were identified upon the pressure of chemotherapy. In summary, we confirmed the high sensitivity and universal applicability of HTS in MRD detection. We also reported the ubiquitous evolved IGH clones in B-ALL samples and their response to chemotherapy during treatment.

  10. Influence of spurious hemolysis on blood gas analysis.

    Science.gov (United States)

    Lippi, Giuseppe; Fontana, Rossana; Avanzini, Paola; Sandei, Franca; Ippolito, Luigi

    2013-08-01

    Although the prevalence of hemolyzed samples referred for blood gas analysis is as high as 4%, no studies have assessed the bias introduced by spurious erythrocyte breakdown, nor it is known which parameters are mostly influenced and to what extent. This study was hence planned to assess the influence of spurious hemolysis on venous blood gas analysis. Venous blood was collected from nine healthy volunteers in sodium heparin tubes and divided in two aliquots of 3 mL. The former aliquot was mechanically hemolyzed by aspiration with 0.5 mL insulin syringe equipped with 30 gauge needle. One milliliter of all aliquots was tested for hemoglobin, pH, oxygen partial pressure (pO₂), partial pressure of carbon dioxide (pCO₂), bicarbonate (HCO³⁻), oxygen tension at 50% hemoglobin saturation (p50), oxygen saturation (sO₂), actual base excess (ABE), carboxyhemoglobin (COHb), methemoglobin (metHb), ionized calcium (Ca²⁺) and potassium, on ABL800 flex. The remaining 2 mL of blood were centrifuged, plasma separated and tested for hemolysis index. The concentration of cell-free hemoglobin increased from blood, significant decreases were found for pH (-0.2%), pO₂ (-4.9%), sO₂ (-4.9%), COHb (-11%) and Ca²⁺ (-7.0%), whereas significant increases were observed for pCO₂ (+4.1%), HCO³⁻ (+1.4%) and potassium (+152%). Clinically meaningful bias was found for pO₂, pCO₂, Ca²⁺ and potassium. Spurious hemolysis is likely to introduce meaningful biases in blood gas analysis, hence manufacturers of blood gas analyzers should develop instrumentation capable of identifying interfering substances in whole blood. The presence of spurious hemolysis should also be suspected whenever test results do not reflect the clinics.

  11. Startup analysis for a high temperature gas loaded heat pipe

    Science.gov (United States)

    Sockol, P. M.

    1973-01-01

    A model for the rapid startup of a high-temperature gas-loaded heat pipe is presented. A two-dimensional diffusion analysis is used to determine the rate of energy transport by the vapor between the hot and cold zones of the pipe. The vapor transport rate is then incorporated in a simple thermal model of the startup of a radiation-cooled heat pipe. Numerical results for an argon-lithium system show that radial diffusion to the cold wall can produce large vapor flow rates during a rapid startup. The results also show that startup is not initiated until the vapor pressure p sub v in the hot zone reaches a precise value proportional to the initial gas pressure p sub i. Through proper choice of p sub i, startup can be delayed until p sub v is large enough to support a heat-transfer rate sufficient to overcome a thermal load on the heat pipe.

  12. Noble Gas Measurement and Analysis Technique for Monitoring Reprocessing Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Charlton, William S [Univ. of California, Berkeley, CA (United States)

    1999-09-01

    An environmental monitoring technique using analysis of stable noble gas isotopic ratios on-stack at a reprocessing facility was developed. This technique integrates existing technologies to strengthen safeguards at reprocessing facilities. The isotopic ratios are measured using a mass spectrometry system and are compared to a database of calculated isotopic ratios using a Bayesian data analysis method to determine specific fuel parameters (e.g., burnup, fuel type, fuel age, etc.). These inferred parameters can be used by investigators to verify operator declarations. A user-friendly software application (named NOVA) was developed for the application of this technique. NOVA included a Visual Basic user interface coupling a Bayesian data analysis procedure to a reactor physics database (calculated using the Monteburns 3.01 code system). The integrated system (mass spectrometry, reactor modeling, and data analysis) was validated using on-stack measurements during the reprocessing of target fuel from a U.S. production reactor and gas samples from the processing of EBR-II fast breeder reactor driver fuel. These measurements led to an inferred burnup that matched the declared burnup with sufficient accuracy and consistency for most safeguards applications. The NOVA code was also tested using numerous light water reactor measurements from the literature. NOVA was capable of accurately determining spent fuel type, burnup, and fuel age for these experimental results. Work should continue to demonstrate the robustness of this system for production, power, and research reactor fuels.

  13. An Analysis of Quality of Service (QoS In Live Video Streaming Using Evolved HSPA Network Media

    Directory of Open Access Journals (Sweden)

    Achmad Zakaria Azhar

    2016-10-01

    Full Text Available Evolved High Speed Packet Access (HSPA+ is a mobile telecommunication system technology and the evolution of HSPA technology. This technology has a packet data based service with downlink speeds up to 21.1 Mbps and uplink speed up to 11.5 Mbps on the bandwidth 5MHz. This technology is expected to fulfill and support the needs for information that involves all aspects of multimedia such as video and audio, especially live video streaming. By utilizing this technology it will facilitate communicating the information, for example to monitoring the situation of the house, the news coverage at some certain area, and other events in real time. This thesis aims to identify and test the Quality of Service (QoS performance on the network that is used for live video streaming with the parameters of throughput, delay, jitter and packet loss. The software used for monitoring the data traffic of the live video streaming network is wireshark network analyzer. From the test results it is obtained that the average throughput of provider B is 5,295 Kbps bigger than the provider A, the average delay of provider B is 0.618 ms smaller than the provider A, the average jitter of provider B is 0.420 ms smaller than the provider A and the average packet loss of provider B is 0.451% smaller than the provider A.

  14. Qualitative Analysis of the Time-Frequency Signature Induced by a Reflected L-Band Signal from Time Evolving Sea Surfaces

    CERN Document Server

    Coatanhay, Arnaud

    2013-01-01

    Passive remote sensing techniques have become more and more popular for detection and characterization purposes. The advantage of using the Global Navigation Satellite Systems (GNSS) are the well known signals emitted and the availability in most areas on Earth. In the present paper, L-Band signals (including GNSS signals) are considered for oceanographic purposes. The main interest in this contribution is the analysis of the signal reflected by an evolving sea surface using time-frequency transforms. The features which occur in this domain are examined in relation to the physical phenomena: interaction of the electromagnetic waves with the moving sea surface.

  15. Analysis of Water Features in Gas Leakage Area

    Directory of Open Access Journals (Sweden)

    Liu Huaishan

    2011-01-01

    Full Text Available In a certain frequency range, gas is an effective absorber and scatterer of sound, which changes the compressibility of water, and then changes the speed and frequency of sound. Gas continues rising, deforming, and dissolving. The same bubble of natural gas has different radii at different depths. By analyzing these changes, the resonance frequency of gas bubble, and its impacts on sound wave, characteristics of the influences of gas at different depths on the incident sound wave can be obtained. The main sound features of gas are relevant to the gas size, gas content, velocity, attenuation, resonance frequency, the scattering cross-section, and so forth. Sound models with hydrate and free gas in the water and sediment are established. Through the practical application to actual data, the sound characteristics yielded when the gas (or gas hydrate dissociation escaped the water of seismic data are very clear.

  16. Population level analysis of evolved mutations underlying improvements in plant hemicellulose and cellulose fermentation by Clostridium phytofermentans.

    Directory of Open Access Journals (Sweden)

    Supratim Mukherjee

    Full Text Available The complexity of plant cell walls creates many challenges for microbial decomposition. Clostridium phytofermentans, an anaerobic bacterium isolated from forest soil, directly breaks down and utilizes many plant cell wall carbohydrates. The objective of this research is to understand constraints on rates of plant decomposition by Clostridium phytofermentans and identify molecular mechanisms that may overcome these limitations.Experimental evolution via repeated serial transfers during exponential growth was used to select for C. phytofermentans genotypes that grow more rapidly on cellobiose, cellulose and xylan. To identify the underlying mutations an average of 13,600,000 paired-end reads were generated per population resulting in ∼300 fold coverage of each site in the genome. Mutations with allele frequencies of 5% or greater could be identified with statistical confidence. Many mutations are in carbohydrate-related genes including the promoter regions of glycoside hydrolases and amino acid substitutions in ABC transport proteins involved in carbohydrate uptake, signal transduction sensors that detect specific carbohydrates, proteins that affect the export of extracellular enzymes, and regulators of unknown specificity. Structural modeling of the ABC transporter complex proteins suggests that mutations in these genes may alter the recognition of carbohydrates by substrate-binding proteins and communication between the intercellular face of the transmembrane and the ATPase binding proteins.Experimental evolution was effective in identifying molecular constraints on the rate of hemicellulose and cellulose fermentation and selected for putative gain of function mutations that do not typically appear in traditional molecular genetic screens. The results reveal new strategies for evolving and engineering microorganisms for faster growth on plant carbohydrates.

  17. Congenic strain analysis reveals genes that are rapidly evolving components of a prezygotic isolation mechanism mediating incipient reinforcement.

    Directory of Open Access Journals (Sweden)

    Christina M Laukaitis

    Full Text Available Two decades ago, we developed a congenic strain of Mus musculus, called b-congenic, by replacing the androgen-binding protein Abpa27(a allele in the C3H/HeJ genome with the Abpa27(b allele from DBA/2J. We and other researchers used this b-congenic strain and its C3H counterpart, the a-congenic strain, to test the hypothesis that, given the choice between signals from two strains with different a27 alleles on the same genetic background, test subjects would prefer the homosubspecific one. It was our purpose in undertaking this study to characterize the segment transferred from DBA to the C3H background in producing the b-congenic strain on which a role for ABPA27 in behavior has been predicated. We determined the size of the chromosome 7 segment transferred from DBA and the genes it contains that might influence preference. We found that the "functional" DBA segment is about 1% the size of the mouse haploid genome and contains at least 29 genes expressed in salivary glands, however, only three of these encode proteins identified in the mouse salivary proteome. At least two of the three genes Abpa27, Abpbg26 and Abpbg27 encoding the subunits of androgen-binding protein ABP dimers evolved under positive selection and the third one may have also. In the sense that they are subunits of the same two functional entities, the ABP dimers, we propose that their evolutionary histories might not be independent of each other.

  18. Advancement and application of gas chromatography isotope ratio mass spectrometry techniques for atmospheric trace gas analysis

    Science.gov (United States)

    Giebel, Brian M.

    2011-12-01

    The use of gas chromatography isotope ratio mass spectrometry (GC-IRMS) for compound specific stable isotope analysis is an underutilized technique because of the complexity of the instrumentation and high analytical costs. However stable isotopic data, when coupled with concentration measurements, can provide additional information on a compounds production, transformation, loss, and cycling within the biosphere and atmosphere. A GC-IRMS system was developed to accurately and precisely measure delta13C values for numerous oxygenated volatile organic compounds having natural and anthropogenic sources. The OVOCs include methanol, ethanol, acetone, methyl ethyl ketone, 2-pentanone, and 3-pentanone. Guided by the requirements for analysis of trace components in air, the GC-IRMS system was developed with the goals of increasing sensitivity, reducing dead-volume and peak band broadening, optimizing combustion and water removal, and decreasing the split ratio to the IRMS. The technique relied on a two-stage preconcentration system, a low-volume capillary reactor and water trap, and a balanced reference gas delivery system. Measurements were performed on samples collected from two distinct sources (i.e. biogenic and vehicle emissions) and ambient air collected from downtown Miami and Everglades National Park. However, the instrumentation and the method have the capability to analyze a variety of source and ambient samples. The measured isotopic signatures that were obtained from source and ambient samples provide a new isotopic constraint for atmospheric chemists and can serve as a new way to evaluate their models and budgets for many OVOCs. In almost all cases, OVOCs emitted from fuel combustion were enriched in 13C when compared to the natural emissions of plants. This was particularly true for ethanol gas emitted in vehicle exhaust, which was observed to have a uniquely enriched isotopic signature that was attributed to ethanol's corn origin and use as an alternative

  19. ANALYSIS OF SITUATION WITH THE GAS AND OIL SECTOR IN IRAQ

    Directory of Open Access Journals (Sweden)

    Aziz Hayder Saleh

    2014-01-01

    Full Text Available This article discusses the current state of oil and gas complex and comparative dataon reserves and production of oil and gasin Iraq. It is also consists the analysis ofthe foreign investment in the oil and gas sector.

  20. Rise in accuracy of gas stream spectral analysis in mechanical engineering technology

    Science.gov (United States)

    Mukhametzyanova, G. F.; Karikh, F. G.; Mukhametzyanov, I. R.

    2017-09-01

    The submitted method of rise in accuracy of gas stream spectral analysis in mechanical engineering technology by controlling the chemical composition of the exhaust gas streams by means of a six-jet electric-arc plasmatron is available.

  1. Methane Venting in Gas Hydrate Potential Area Offshore of SW Taiwan: Evidence of Gas Analysis of Water Column Samples

    Directory of Open Access Journals (Sweden)

    Tsanyao Frank Yang

    2006-01-01

    Full Text Available Water column samples were collected systematically in several potential gas hydrate areas offshore of SW Taiwan for analysis of dissolved gases. Some these samples show unusually high dissolved methane concentrations at sites A, B, C, and H of cruise ORI-765. The profiles of helium concentrations in the dissolved gases of the water column also exhibit consistent results with an increasing trend toward the seafloor. The 3He/4He ratios range from 0.2 to 0.4 times that of the atmospheric air ratio after air correction, which fall in the range of typical crustal gas composition and are similar to those of on-shore mud volcanoes in SW Taiwan. This indicates that gases are venting actively from the seafloor in the region and may share similar gas sources to on-shore mud volcanoes. The venting gases are considered to have originated from dissociation of gas hydrates and/or a deeper gas reservoir.

  2. Sensitivity analysis and economic optimization studies of inverted five-spot gas cycling in gas condensate reservoir

    Science.gov (United States)

    Shams, Bilal; Yao, Jun; Zhang, Kai; Zhang, Lei

    2017-08-01

    Gas condensate reservoirs usually exhibit complex flow behaviors because of propagation response of pressure drop from the wellbore into the reservoir. When reservoir pressure drops below the dew point in two phase flow of gas and condensate, the accumulation of large condensate amount occurs in the gas condensate reservoirs. Usually, the saturation of condensate accumulation in volumetric gas condensate reservoirs is lower than the critical condensate saturation that causes trapping of large amount of condensate in reservoir pores. Trapped condensate often is lost due to condensate accumulation-condensate blockage courtesy of high molecular weight, heavy condensate residue. Recovering lost condensate most economically and optimally has always been a challenging goal. Thus, gas cycling is applied to alleviate such a drastic loss in resources. In gas injection, the flooding pattern, injection timing and injection duration are key parameters to study an efficient EOR scenario in order to recover lost condensate. This work contains sensitivity analysis on different parameters to generate an accurate investigation about the effects on performance of different injection scenarios in homogeneous gas condensate system. In this paper, starting time of gas cycling and injection period are the parameters used to influence condensate recovery of a five-spot well pattern which has an injection pressure constraint of 3000 psi and production wells are constraint at 500 psi min. BHP. Starting injection times of 1 month, 4 months and 9 months after natural depletion areapplied in the first study. The second study is conducted by varying injection duration. Three durations are selected: 100 days, 400 days and 900 days. In miscible gas injection, miscibility and vaporization of condensate by injected gas is more efficient mechanism for condensate recovery. From this study, it is proven that the application of gas cycling on five-spot well pattern greatly enhances condensate recovery

  3. Integrated Analysis of Optimizing Tubing Material Selection for Gas Wells

    Directory of Open Access Journals (Sweden)

    Bonar Tua Halomoan Marbun

    2015-07-01

    Full Text Available Corrosion in production tubing strings is seen as a challenging problem in gas wells containing carbon dioxideand hydrogen sulfide. This paper presents a new comprehensive method of corrosion rate calculation with integrated study of reservoir condition, nodal analysis of the well, and well trajectory, which could also have an effect due to the possibility of different flow regimes of the production fluid. This method is applicable to evaluate and predict the performance of selected tubing size and material. This method can also give an economic evaluation for the consideration of using corrosion resistant alloy (CRA or low-alloy steel and carbon steel. The measurement of corrosion rate can be done by several methods,such as using corrosion coupons, calculating the iron content inside the production fluid, or probes. Either way, when the corrosion rate measured in the field is still below the acceptable maximum corrosion rate, it can be said that the adequacy of this method is guaranteed. This method has been implemented in a gas field,where it successfully selected the best tubing material for the next development well in this field. Consequently, the lifetime of the tubing strings could be extended,resulting in an economical benefit as well.

  4. Environmental risk analysis for offshore oil and gas activities

    Energy Technology Data Exchange (ETDEWEB)

    Brude, Odd Willy; Aspholm, Ole O.; Rudberg, Anders [Det Norske Veritas (Brazil)

    2008-07-01

    Offshore oil and gas activities always have a risk for environmental impact due to potential accidental releases of oil and gas. The environmental risk can be calculated as a combination of the frequency of such accidents to occur and their environmental consequences in terms of environmental damage to habitats or populations. A method for conducting environmental risk analysis has been in use in Norwegian offshore waters for a decade, with a continuously refinement of methodology over the past years. This paper outlines the principles in the MIRA method and gives examples and discussions regarding use in different environmental compartments. The risk assessment starts with identification of oil spill scenarios with frequencies of potential release rates and spill durations. The next step is to model the oil drift for each accidental oil spill scenario. Drift and fate of oil is modeled probabilistic. Based on the oil spill scenarios and their probability of oil pollution, the potential environmental damage is quantified for each scenario. The endpoint of environmental damage is reduction of a population and the resulting recovery time (in years) for various species and habitats. Environmental risk levels are then evaluated against the operating companies' environmental acceptance criteria. (author)

  5. Generic Analysis Methods for Gas Turbine Engine Performance: The development of the gas turbine simulation program GSP

    OpenAIRE

    Visser, W.P.J.

    2015-01-01

    Numerical modelling and simulation have played a critical role in the research and development towards today’s powerful and efficient gas turbine engines for both aviation and power generation. The simultaneous progress in modelling methods, numerical methods, software development tools and methods, and computer platform technology has provided the gas turbine community with ever more accurate design, performance prediction and analysis tools. An important element is the development towards g...

  6. Determination of volatiles in volcanic rocks and minerals with a Directly Coupled Evolved Gas Analyzing System (DEGAS -Part I: Interpretation of degassing profiles (DEGAS-profiles of minerals and rocks on the basis of melting experiments

    Directory of Open Access Journals (Sweden)

    C. M. Schmidt

    2005-06-01

    Full Text Available Volatile components in magma strongly influence many physical properties of melts and minerals. The temperature resolved degassing analysis of volcanic crystalline and vitreous rocks gives detailed information about volatile compounds in the melt. Aspecial high-temperature mass-spectrometry device in combination with a thermo-balance allows a quantitative determination of different volatile species. It enables a differentiation between the primary gas content in the magma and the gas released from decomposition of secondary alteration products. The gas release profiles give the following indications: i during the littoral explosions of Pahoehoe lava the content of volatiles is not changed by interaction with air or sea water; ii the degassing profiles of vitreous black sand verify the primary content of volatiles in the erupted melt, only CO2 was detected; iii the oxygen release profile gives significant indications for oxygen undersaturation of the erupted magma; iv remelting of black sand in air at 1450°C for 0.45 h causes an oxygen saturation of the basaltic melt; v remelting of black sand in argon atmosphere confirms the oxygen undersaturation of the melt; vi remelting of black sand-black shale mixtures affects a significant change in the degassing profiles, especially in CO2-release. With the first investigations we can demonstrate that gas release curves of volcanic rocks are qualified for a detection of the primary gas content of erupted magma; b detection of alteration processes of the igneous glass; c detection of contamination of the magma with adjacent rocks.

  7. Comparative analysis from hydroelectric generation versus natural gas; Analise comparativa da geracao eletrica hidrica versus gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Galvao, Luiz Claudio Ribeiro; Boarati, Julio Henrique; Shayani, Rafael Amaral; Udaeta, Miguel Edgar Morales [Sao Paulo Univ., SP (Brazil). Escola Politecnica. Dept. de Engenharia de Energia e Automacao Eletricas]. E-mail: udaeta@pea.usp.br

    1999-07-01

    The aim of the work was to present a comparative analysis between hydroelectric generation and natural gas based on integrated resource planning and sustainable development. The introduced comparative analysis considers the financial aspects; the appropriated technology; and the social, environmental and political factors. The hydroelectric option it showed more advantageous than the thermoelectric. This result was independent of the enterprise scale.

  8. Evolving digital ecological networks.

    Directory of Open Access Journals (Sweden)

    Miguel A Fortuna

    Full Text Available "It is hard to realize that the living world as we know it is just one among many possibilities" [1]. Evolving digital ecological networks are webs of interacting, self-replicating, and evolving computer programs (i.e., digital organisms that experience the same major ecological interactions as biological organisms (e.g., competition, predation, parasitism, and mutualism. Despite being computational, these programs evolve quickly in an open-ended way, and starting from only one or two ancestral organisms, the formation of ecological networks can be observed in real-time by tracking interactions between the constantly evolving organism phenotypes. These phenotypes may be defined by combinations of logical computations (hereafter tasks that digital organisms perform and by expressed behaviors that have evolved. The types and outcomes of interactions between phenotypes are determined by task overlap for logic-defined phenotypes and by responses to encounters in the case of behavioral phenotypes. Biologists use these evolving networks to study active and fundamental topics within evolutionary ecology (e.g., the extent to which the architecture of multispecies networks shape coevolutionary outcomes, and the processes involved.

  9. A versatile gas interface for routine radiocarbon analysis with a gas ion source

    Energy Technology Data Exchange (ETDEWEB)

    Wacker, L., E-mail: wacker@phys.ethz.ch [Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich (Switzerland); Fahrni, S.M. [Department of Chemistry and Biochemistry, University of Bern, 3012 Berne (Switzerland); Oeschger Centre for Climate Change Research, University of Bern, 3012 Berne (Switzerland); Paul Scherrer Institute (PSI), 5232 Villigen (Switzerland); Hajdas, I. [Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich (Switzerland); Molnar, M. [Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich (Switzerland); Institute of Nuclear Research, Hungarian Academy of Sciences, 4026 Debrecen (Hungary); Synal, H.-A. [Laboratory of Ion Beam Physics, ETH Zurich, 8093 Zurich (Switzerland); Szidat, S. [Department of Chemistry and Biochemistry, University of Bern, 3012 Berne (Switzerland); Oeschger Centre for Climate Change Research, University of Bern, 3012 Berne (Switzerland); Zhang, Y.L. [Department of Chemistry and Biochemistry, University of Bern, 3012 Berne (Switzerland); Oeschger Centre for Climate Change Research, University of Bern, 3012 Berne (Switzerland); Paul Scherrer Institute (PSI), 5232 Villigen (Switzerland)

    2013-01-15

    In 2010 more than 600 radiocarbon samples were measured with the gas ion source at the MIni CArbon DAting System (MICADAS) at ETH Zurich and the number of measurements is rising quickly. While most samples contain less than 50 {mu}g C at present, the gas ion source is attractive as well for larger samples because the time-consuming graphitization is omitted. Additionally, modern samples are now measured down to 5 per-mill counting statistics in less than 30 min with the recently improved gas ion source. In the versatile gas handling system, a stepping-motor-driven syringe presses a mixture of helium and sample CO{sub 2} into the gas ion source, allowing continuous and stable measurements of different kinds of samples. CO{sub 2} can be provided in four different ways to the versatile gas interface. As a primary method, CO{sub 2} is delivered in glass or quartz ampoules. In this case, the CO{sub 2} is released in an automated ampoule cracker with 8 positions for individual samples. Secondly, OX-1 and blank gas in helium can be provided to the syringe by directly connecting gas bottles to the gas interface at the stage of the cracker. Thirdly, solid samples can be combusted in an elemental analyzer or in a thermo-optical OC/EC aerosol analyzer where the produced CO{sub 2} is transferred to the syringe via a zeolite trap for gas concentration. As a fourth method, CO{sub 2} is released from carbonates with phosphoric acid in septum-sealed vials and loaded onto the same trap used for the elemental analyzer. All four methods allow complete automation of the measurement, even though minor user input is presently still required. Details on the setup, versatility and applications of the gas handling system are given.

  10. Flammable gas tank safety program: Technical basis for gas analysis and monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Sherwood, D.J.

    1995-09-08

    Flammable gases generated in radioactive liquids. Twenty-five high level radioactive liquid waste storage tanks located underground at the Hanford Site are on a Flammable Gas Watch List because they contain waste which tends to retain the gases generated in it until rather large quantities are available for sudden release to the tank head space; if a tank is full it has little dome space, and a flammable concentration of gases could be produced--even if the tank is ventilated. If the waste has no tendency to retain gas generated in it then a continual flammable gas concentration in the tank dome space is established by the gas production rate and the tank ventilation rate (or breathing rate for unventilated tanks); this is also a potential problem for Flammable Gas Watch List tanks, and perhaps other Hanford tanks too. All Flammable Gas Watch List tanks will be fitted with Standard Hydorgen Monitoring Systems so that their behavior can be observed. In some cases, such as tank 241-SY-101, the data gathered from such observations will indicate that tank conditions need to be mitigated so that gas release events are either eliminated or rendered harmless. For example, a mixer pump was installed in tank 241-SY-101; operating the pump stirs the waste, replacing the large gas release events with small releases of gas that are kept below twenty-five percent of the lower flammability limit by the ventilation system. The concentration of hydrogen measured in Hanford waste tanks is greater than that of any other flammable gas. Hydrogen levels measured with a Standard Hydrogen Monitoring System in excess of 0.6 volume percent will cause Westinghouse Hanford Company to consider actions which will decrease the amount of flammable gas in the tank

  11. EBI metagenomics in 2016 - an expanding and evolving resource for the analysis and archiving of metagenomic data

    Science.gov (United States)

    Mitchell, Alex; Bucchini, Francois; Cochrane, Guy; Denise, Hubert; Hoopen, Petra ten; Fraser, Matthew; Pesseat, Sebastien; Potter, Simon; Scheremetjew, Maxim; Sterk, Peter; Finn, Robert D.

    2016-01-01

    EBI metagenomics (https://www.ebi.ac.uk/metagenomics/) is a freely available hub for the analysis and archiving of metagenomic and metatranscriptomic data. Over the last 2 years, the resource has undergone rapid growth, with an increase of over five-fold in the number of processed samples and consequently represents one of the largest resources of analysed shotgun metagenomes. Here, we report the status of the resource in 2016 and give an overview of new developments. In particular, we describe updates to data content, a complete overhaul of the analysis pipeline, streamlining of data presentation via the website and the development of a new web based tool to compare functional analyses of sequence runs within a study. We also highlight two of the higher profile projects that have been analysed using the resource in the last year: the oceanographic projects Ocean Sampling Day and Tara Oceans. PMID:26582919

  12. Failure analysis of gas turbine blades in a gas turbine engine used ...

    African Journals Online (AJOL)

    The gas turbine blade under examination was operated at elevated temperatures in corrosive environmental attack such as oxidation, hot corrosion and sulphidation etc. The investigation on gas turbine blade included the activities like visual inspection, determination of material composition, microscopic examination and ...

  13. Shaly gas-sand analysis using hand-carried calculators

    Energy Technology Data Exchange (ETDEWEB)

    Wu, C.H. (Colorado School of Mines, Golden); Krug, J.

    1979-05-01

    A well log evaluation program is presented in this article for shaly-sand cross-plot analysis using either the Hewlett Parkard HP-97 or HP-67 calculator. This program uses analytic methods to compute the effective porosity and shale content from a density (rho/sub b/) and a neutron log porosity (phiN) cross-plot. When hydrocarbon effect is significant, the gamma ray log or spontaneous potential log response is used to compute a shale-corrected, and consequently, hydrocarbon-corrected porosity. First the porosity and shale content are computed, then the water saturation is calculated using the total shale formula. The program has been tested on low permeability (tight) gas-sand analysis and the results are comparable with SARABRAND sand-shale analysis. The accuracy and versatility of the program allows the user to: (1) evaluate shaly formations accurately and quickly in the field and to assist on-site decisions for formation tests and completion; and (2) determine the effect of log parameters on the porosity and saturation calculations or to spot-check SARABRAND results quickly for hydrocarbon-in-place estimates. Furthermore, the program should relieve the user from tedious shaly-sand calculations and allow more time for log quality control and interpretation.

  14. Technology and Greenhouse Gas Emissions: An IntegratedScenario Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Koomey, J.G.; Latiner, S.; Markel, R.J.; Marnay, C.; Richey, R.C.

    1998-09-01

    This report describes an analysis of possible technology-based scenarios for the U.S. energy system that would result in both carbon savings and net economic benefits. We use a modified version of the Energy Information Administration's National Energy Modeling System (LBNL-NEMS) to assess the potential energy, carbon, and bill savings from a portfolio of carbon saving options. This analysis is based on technology resource potentials estimated in previous bottom-up studies, but it uses the integrated LBNL-NEMS framework to assess interactions and synergies among these options. The analysis in this paper builds on previous estimates of possible "technology paths" to investigate four major components of an aggressive greenhouse gas reduction strategy: (1) the large scale implementation of demand-side efficiency, comparable in scale to that presented in two recent policy studies on this topic; (2) a variety of "alternative" electricity supply-side options, including biomass cofiring, extension of the renewable production tax credit for wind, increased industrial cogeneration, and hydropower refurbishment. (3) the economic retirement of older and less efficient existing fossil-find power plants; and (4) a permit charge of $23 per metric ton of carbon (1996 $/t),l assuming that carbon trading is implemented in the US, and that the carbon permit charge equilibrates at this level. This level of carbon permit charge, as discussed later in the report, is in the likely range for the Clinton Administration's position on this topic.

  15. Residual gas analysis of volatile impurities in halide precursors for scintillator crystals

    Science.gov (United States)

    Swider, S.; Motakef, S.; Datta, A.; Higgins, W. M.

    2013-09-01

    Alkaline-earth halides can be made into bright scintillators if purity is maintained during synthesis and growth. In order to investigate precursor purity, beaded halide precursors were heated under vacuum and evolved gas was assessed by residual gas spectroscopy. These precursors included cesium chloride, lithium chloride, yttrium chloride, cerium chloride, strontium iodide, europium iodide, barium bromide, and europium bromide. Water and CO2 desorption, sulfur release, argon release, and halide dissociation was observed in samples. Triply-oxidized precursors showed multiple paths to decomposition. The data inform approaches toward purification and growth.

  16. EBI metagenomics in 2016--an expanding and evolving resource for the analysis and archiving of metagenomic data.

    Science.gov (United States)

    Mitchell, Alex; Bucchini, Francois; Cochrane, Guy; Denise, Hubert; ten Hoopen, Petra; Fraser, Matthew; Pesseat, Sebastien; Potter, Simon; Scheremetjew, Maxim; Sterk, Peter; Finn, Robert D

    2016-01-04

    EBI metagenomics (https://www.ebi.ac.uk/metagenomics/) is a freely available hub for the analysis and archiving of metagenomic and metatranscriptomic data. Over the last 2 years, the resource has undergone rapid growth, with an increase of over five-fold in the number of processed samples and consequently represents one of the largest resources of analysed shotgun metagenomes. Here, we report the status of the resource in 2016 and give an overview of new developments. In particular, we describe updates to data content, a complete overhaul of the analysis pipeline, streamlining of data presentation via the website and the development of a new web based tool to compare functional analyses of sequence runs within a study. We also highlight two of the higher profile projects that have been analysed using the resource in the last year: the oceanographic projects Ocean Sampling Day and Tara Oceans. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  17. Thermoeconomic and thermoenvironomic modeling and analysis of selected gas turbine power plants in Nigeria

    National Research Council Canada - National Science Library

    Oyedepo, Sunday O; Fagbenle, Richard O; Adefila, Samuel S; Alam, Md. Mahbub

    2015-01-01

    This study presents comprehensive thermoeconomic and thermoenvironomic modeling and analysis of selected gas turbine power plants in Nigeria using the first and second laws of thermodynamics (exergy) concept...

  18. [Analysis of benzodiazepine derivative mixture by gas-liquid chromatography].

    Science.gov (United States)

    Zevzikovas, Andrejus; Kiliuviene, Guoda; Ivanauskas, Liudas; Dirse, Vidmantas

    2002-01-01

    The analysis of mixture of benzodiazepine derivates (chlordiazepoxide, flunitrazepam, medazepam, nitrazepam, oxazepam and tetrazepam) by gas--liquid chromatography (GLC) in purpose to separate and identify these psychotropic drugs in mixture is presented in this article. The experiment was carried out in vitro, accommodating this method for identification and separation of drugs, isolated from biological objects (blood and urine). Referring to data of annual reports of chemical investigations (1) above-mentioned psychotropic drugs are very frequent among drug intoxication. In most cases they are detected in the mixture of the same or different pharmacological group, and this causes difficulty for separation and identification. The analysis of the mixture was carried out by GLC, which is widely used in practice of forensic-chemical examination. Adsorbents and stationery phases were changed; the conditions and parameters of chromatography were modified, in purpose totally separate preparations in the mixture. For the separation and identification of all three preparation the column packed with Inerton Super with stationary phase 3% OV-17 is suitable. The column temperature-290 degrees C. The mixture of these drugs was excreted from body fluids (blood and urine) in vitro and investigated by GLC under these conditions. The results of investigation were similar.

  19. Differentiation at autopsy between in vivo gas embolism and putrefaction using gas composition analysis.

    Science.gov (United States)

    Bernaldo de Quirós, Yara; González-Díaz, Oscar; Møllerløkken, Andreas; Brubakk, Alf O; Hjelde, Astrid; Saavedra, Pedro; Fernández, Antonio

    2013-03-01

    Gas embolism can arise from different causes (iatrogenic accidents, criminal interventions, or diving related accidents). Gas analyses have been shown to be a valid technique to differentiate between putrefaction gases and gas embolism. In this study, we performed systematic necropsies at different postmortem times in three experimental New Zealand White Rabbits models: control or putrefaction, infused air embolism, and compression/decompression. The purpose of this study was to look for qualitative and quantitative differences among groups and to observe how putrefaction gases mask in vivo gas embolism. We found that the infused air embolism and compression/decompression models had a similar gas composition prior to 27-h postmortem, being typically composed of around 70-80 % of N(2) and 20-30 % of CO(2), although unexpected higher CO(2) concentrations were found in some decompressed animals, putting in question the role of CO(2) in decompression. All these samples were statistically and significantly different from more decomposed samples. Gas composition of samples from more decomposed animals and from the putrefaction model presented hydrogen, which was therefore considered as a putrefaction marker.

  20. Comparison of Boolean analysis and standard phylogenetic methods using artificially evolved and natural mt-tRNA sequences from great apes.

    Science.gov (United States)

    Ari, Eszter; Ittzés, Péter; Podani, János; Thi, Quynh Chi Le; Jakó, Eena

    2012-04-01

    Boolean analysis (or BOOL-AN; Jakó et al., 2009. BOOL-AN: A method for comparative sequence analysis and phylogenetic reconstruction. Mol. Phylogenet. Evol. 52, 887-97.), a recently developed method for sequence comparison uses the Iterative Canonical Form of Boolean functions. It considers sequence information in a way entirely different from standard phylogenetic methods (i.e. Maximum Parsimony, Maximum-Likelihood, Neighbor-Joining, and Bayesian analysis). The performance and reliability of Boolean analysis were tested and compared with the standard phylogenetic methods, using artificially evolved - simulated - nucleotide sequences and the 22 mitochondrial tRNA genes of the great apes. At the outset, we assumed that the phylogeny of Hominidae is generally well established, and the guide tree of artificial sequence evolution can also be used as a benchmark. These offer a possibility to compare and test the performance of different phylogenetic methods. Trees were reconstructed by each method from 2500 simulated sequences and 22 mitochondrial tRNA sequences. We also introduced a special re-sampling method for Boolean analysis on permuted sequence sites, the P-BOOL-AN procedure. Considering the reliability values (branch support values of consensus trees and Robinson-Foulds distances) we used for simulated sequence trees produced by different phylogenetic methods, BOOL-AN appeared as the most reliable method. Although the mitochondrial tRNA sequences of great apes are relatively short (59-75 bases long) and the ratio of their constant characters is about 75%, BOOL-AN, P-BOOL-AN and the Bayesian approach produced the same tree-topology as the established phylogeny, while the outcomes of Maximum Parsimony, Maximum-Likelihood and Neighbor-Joining methods were equivocal. We conclude that Boolean analysis is a promising alternative to existing methods of sequence comparison for phylogenetic reconstruction and congruence analysis. Copyright © 2012 Elsevier Inc. All

  1. Engineering Economic Analysis for Feed Gas Cooler (Cold box: a Case of a Gas Processing Complex in Malaysia

    Directory of Open Access Journals (Sweden)

    Ghazali Zulkipli

    2014-07-01

    Full Text Available This study examine the economic feasibility of a proposal to replace an existing Feed Gas Cooler (Cold Box with a new unit in a gas processing complex in Malaysia. Economic justification is essential to make the decision on the feasibility of this undertaking because of the high capital investment. The mathematical model presented in the paper includes net present worth, payback period, rate of return, investment balance analysis, and sensitivity analysis. Critical analyses on four factors of the estimates were done to assess their influence on the overall economic justification of the proposal. The results indicate an acceptable return on investment. However, the proposal is susceptible to the variation in demand of the Feed Gas Load.

  2. Economics of lifecycle analysis and greenhouse gas regulations

    Science.gov (United States)

    Rajagopal, Deepak

    2009-11-01

    Interest in alternatives to fossil fuels has risen significantly during the current decade. Although a variety of different alternative technologies have experienced rapid growth, biofuels have emerged as the main alternative transportation fuel. Energy policies in several countries envision blending biofuels with fossil fuels as the main mechanism to increase energy independence and energy security. Climate change policies in several regions are also riding on the same hope for reducing emissions from transportation. The main advantage of biofuels is that they are technically mature, cheaper to produce and more convenient to use relative to other alternative fuels. However, the impact of current biofuels on the environment and on economic welfare, is controversial. In my dissertation I focus on three topics relevant to future energy and climate policies. The first is the economics of lifecycle analysis and its application to the assessment of environmental impact of biofuel policies. The potential of biofuel for reducing greenhouse gas emissions was brought to the fore by research that relied on the methodology called lifecycle analysis (LCA). Subsequent research however showed that the traditional LCA fails to account for market-mediated effects that will arise when biofuel technologies are scaled up. These effects can increase or decrease emissions at each stage of the lifecycle. I discuss how the LCA will differ depending on the scale, a single firm versus a region and why LCA of the future should be distinguished from LCA of the past. I describe some approaches for extending the LCA methodology so that it can be applied under these different situations. The second topic is the economic impact of biofuels. Biofuels reduce the demand for oil and increase the demand for agricultural goods. To high income countries which tend to be both large importers of oil and large exporters of agricultural goods, this implies two major benefits. One of the one hand it reduces

  3. Mentoring: An Evolving Relationship.

    Science.gov (United States)

    Block, Michelle; Florczak, Kristine L

    2017-04-01

    The column concerns itself with mentoring as an evolving relationship between mentor and mentee. The collegiate mentoring model, the transformational transcendence model, and the humanbecoming mentoring model are considered in light of a dialogue with mentors at a Midwest university and conclusions are drawn.

  4. Measurably evolving populations

    DEFF Research Database (Denmark)

    Drummond, Alexei James; Pybus, Oliver George; Rambaut, Andrew

    2003-01-01

    processes through time. Populations for which such studies are possible � measurably evolving populations (MEPs) � are characterized by sufficiently long or numerous sampled sequences and a fast mutation rate relative to the available range of sequence sampling times. The impact of sequences sampled through...... understanding of evolutionary processes in diverse organisms, from viruses to vertebrates....

  5. Optical Absorption Spectroscopy for Gas Analysis in Biomass Gasification

    DEFF Research Database (Denmark)

    Grosch, Helge

    Biomass gasication as a source of heat, power and chemical feedstock needs monitoring of the gas species to improve the performance and gas quality, deepen the understanding of the process and to be able to control the emission of hazardous compounds. Major species, like H2, CO and CO2, can alrea...

  6. Performance analysis of gas purging operation in volume control tank

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chang Ho; Chung, Chang Kyu; Lim, Duck Jae; Kim, Eun Kee [Korea Power Engineering Company, Taejon (Korea, Republic of)

    2004-07-01

    The Volume Control Tank (VCT) is designed to provide for control of hydrogen concentration in the coolant and the means for the removal of radioactive gases by purging the accumulated gases in the tank. NRC notified the licensees that the charging pump with the minimum bypass line could be damaged by the gas binding in the suction piping. It is caused by the evolution of hydrogen gas at the point where the local pressure is less than the saturated pressure. The purging operation results in the pressure reduction of the VCT. The computer code is developed to evaluate the capacities and set points of the pressure regulating valves which are installed on the gas control system of the VCT. In order to exclude the hydrogen evolution during the purging operation with the supply capacity of 20 SCFM, the set points of the regulating valves for nitrogen gas and hydrogen gas shall not be higher than 45 psig and 30 psig, respectively. The capacities shall be more than 25 SCFM for nitrogen gas and 55 SCFM for hydrogen gas to get the adjustable set point of 20 through 50 psig. To minimize the purging time and the wasted gas mass during the purging operation, the set point shall be reduced as low as possible within this set point range.

  7. Contextual neural gas for spatial clustering and analysis

    NARCIS (Netherlands)

    Hagenauer, J.; Helbich, M.

    2013-01-01

    This study aims to introduce contextual Neural Gas (CNG), a variant of the Neural Gas algorithm, which explicitly accounts for spatial dependencies within spatial data. The main idea of the CNG is to map spatially close observations to neurons, which are close with respect to their rank distance.

  8. Performance analysis of the continuous trace gas preconcentrator

    Science.gov (United States)

    Muntz, E. P.; Han, Y.-L.

    2011-03-01

    In gas molecule detection systems, certain trace gas components can go undetected. This is due to ultralow yet dangerous concentrations combined with limitations of the detection methods. To remedy this problem, a preconcentrator can be included in a system to increase the trace gas concentrations, before the gas samples enter the detection unit. The widely used adsorption/desorption preconcentrators enable detection by interrupting the sampled gas flow for significant periods, in order to accumulate detectable periodic concentrations of trace gas molecules. The recently patented continuous trace gas preconcentrator (CTGP) provides a unique approach for enhancing the trace gas concentration, without stopping the flow. In this study, a performance model is developed for the CTGP, by application of the Poiseuille flow coefficients for long tubes. Based on the Cercignani-Lampis scattering kernel, Sharipov calculated the Poiseuille flow coefficients for various geometries and numerous operating Knudsen numbers. The concentrations of sampled molecules were analyzed in this study using Sharipov's flow coefficients. The results presented here reinforce the potential benefits of the CTGP.

  9. Gas to particle conversion-gas exchange technique for direct analysis of metal carbonyl gas by inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Nishiguchi, Kohei; Utani, Keisuke; Gunther, Detlef; Ohata, Masaki

    2014-10-21

    A novel gas to particle conversion-gas exchange technique for the direct analysis of metal carbonyl gas by inductively coupled plasma mass spectrometry (ICPMS) was proposed and demonstrated in the present study. The technique is based on a transfer of gas into particle, which can be directly analyzed by ICPMS. Particles from metal carbonyl gases such as Cr(CO)6, Mo(CO)6, and W(CO)6 are formed by reaction with ozone (O3) and ammonium (NH3) gases within a newly developed gas to particle conversion device (GPD). The reaction mechanism of the gas to particle conversion is based on either oxidation of metal carbonyl gas by O3 or agglomeration of metal oxide with ammonium nitrate (NH4NO3) which is generated by the reaction of O3 and NH3. To separate the reaction gases (remaining O3 and NH3) from the formed particles, a previously reported gas exchange device (GED) was used and the in argon stabilized analyte particles were directly introduced and measured by ICPMS. This new technique provided limits of detection (LOD) of 0.15 pL L(-1) (0.32 ng m(-3)), 0.02 pL L(-1) (0.07 ng m(-3)), and 0.01 pL L(-1) (0.07 ng m(-3)) for Cr(CO)6, Mo(CO)6, and W(CO)6, respectively, which were 4-5 orders of magnitude lower than those conventional applied for detecting these gases, e.g., gas chromatography with electron captured detector (GC-ECD) as well as Fourier transform-infrared spectroscopy (FT-IR). The achieved LODs were also similar or slightly better than those for ICPMS coupled to GC. Since the gas to particle conversion technique can achieve the direct measurement of metal carbonyl gases as well as the removal of reaction and ambient gases from metal carbonyl gases, the technique is considered to be well suited to monitor gas quality in semiconductor industry, engine exhaust gases, and or waste incineration products.

  10. Multiresidue pesticide analysis by capillary gas chromatography-mass spectrometry.

    Science.gov (United States)

    Wong, Jon W; Zhang, Kai; Hayward, Douglas G; Kai-Meng, Chin

    2011-01-01

    A multiresidue pesticide method using a modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) procedure and capillary gas chromatography-mass spectrometry (GC-MS) is described for the determination of 166 organochlorine, organophosphorus, and pyrethroid pesticides, metabolites, and isomers in spinach. The pesticides from spinach were extracted using acetonitrile saturated with magnesium sulfate and sodium chloride, followed by solid-phase dispersive cleanup using primary-secondary amine and graphitized carbon black sorbents and toluene. Analysis is performed using different GC-MS techniques emphasizing the benefits of non-targeted acquisition and targeted screening procedures. Non-targeted data acquisition of pesticides in the spinach was demonstrated using GC coupled to a single quadrupole mass spectrometery (GC-MS) in full scan mode or multidimensional GC-time-of-flight mass spectrometery (GC  ×  GC-TOF/MS), along with deconvolution software and libraries. Targeted screening was achieved using GC-single quadrupole mass spectrometry in selective ion monitoring (GC-MS/SIM) mode or -tandem mass spectrometry (GC-MS/MS) in multiple reaction monitoring mode. The development of these techniques demonstrates the powerful use of GC-MS for the screening, identification, and quantitation of pesticide residues in foods.

  11. AARC clinical practice guideline: blood gas analysis and hemoximetry: 2013.

    Science.gov (United States)

    Davis, Michael D; Walsh, Brian K; Sittig, Steve E; Restrepo, Ruben D

    2013-10-01

    We searched MEDLINE, CINAHL, and Cochrane Library database for articles published between January 1990 and December 2012. The update of this clinical practice guideline is based on 237 clinical trials, 54 reviews, and 23 meta-analyses on blood gas analysis (BGA) and hemoximetry. The following recommendations are made following the Grading of Recommendations Assessment, Development, and Evaluation scoring system. BGA and hemoximetry are recommended for evaluating a patient's ventilatory, acid-base, and/or oxygenation status. BGA and hemoximetry are suggested for evaluating a patient's response to therapeutic interventions. BGA and hemoximetry are recommended for monitoring severity and progression of documented cardiopulmonary disease processes. Hemoximetry is recommended to determine the impact of dyshemoglobins on oxygenation. Capillary BGA is not recommended to determine oxygenation status. Central venous BGA and hemoximetry are suggested to determine oxygen consumption in the setting of early goal-directed therapies. For the assessment of oxygenation, a peripheral venous P(O2) is not recommended as a substitute for an arterial blood measurement (P(aO2)). It is not recommended to use venous P(CO2) and pH as a substitute for arterial blood measurement of P(aCO2) and pH. It is suggested that hemoximetry is used in the detection and evaluation of shunts during diagnostic cardiac catheterization.

  12. Recent Advances in Water Analysis with Gas Chromatograph Mass Spectrometers

    Science.gov (United States)

    MacAskill, John A.; Tsikata, Edem

    2014-01-01

    We report on progress made in developing a water sampling system for detection and analysis of volatile organic compounds in water with a gas chromatograph mass spectrometer (GCMS). Two approaches are described herein. The first approach uses a custom water pre-concentrator for performing trap and purge of VOCs from water. The second approach uses a custom micro-volume, split-splitless injector that is compatible with air and water. These water sampling systems will enable a single GC-based instrument to analyze air and water samples for VOC content. As reduced mass, volume, and power is crucial for long-duration, manned space-exploration, these water sampling systems will demonstrate the ability of a GCMS to monitor both air and water quality of the astronaut environment, thereby reducing the amount of required instrumentation for long duration habitation. Laboratory prototypes of these water sampling systems have been constructed and tested with a quadrupole ion trap mass spectrometer as well as a thermal conductivity detector. Presented herein are details of these water sampling system with preliminary test results.

  13. Applications of laser-photoacoustic gas analysis method

    Energy Technology Data Exchange (ETDEWEB)

    Hernberg, R.; Stenberg, J. [Tampere Univ. of Technology (Finland). Dept. of Physics

    1996-12-01

    The dynamic behavior of a circulating fluidized bed boiler (CFB) was studied using two high speed gas analysis systems during combustion of coal, peat and wood chips. Time resolved concentrations of some pollutants (SO{sub 2}, NO, NH{sub 3} and H{sub 2}S) were measured using laser induced photoacoustic spectroscopy (LIPS). A zirkonia cell based probe (lambda-probe) was used in synchronization with the LIPS-probe to measure fluctuations between reducing and oxidizing conditions. The two probes were positioned in the same measurement volume on the center-line of the combustion chamber of the CFB. The purpose of the measurements was to investigate the behavior of the LIPS in a combustion chamber containing large amounts of other unburnt hydrocarbons. The correlations between oxidizing and reducing conditions and concentrations at three locations in the combustion chamber are presented. The best correlations were found in the upper part of the CFB combustion chamber. In some cases the correlations between reducing conditions and the LIPS signal were caused by hydrocarbons. Comparison of the average values obtained by the LIPS-system for NO and SO{sub 2} with the result from a sampling probe system connected to on-line analysers was also carried out. (author)

  14. [When is a venous blood gas analysis sufficient in the emergency department?

    NARCIS (Netherlands)

    Exsel, J.A. van; Simons, S.O.; Kramers, C.; Heijdra, Y.F.

    2017-01-01

    Blood gas analysis plays an important role in the initial assessment of a patient in the emergency ward. We present three different patient cases to illustrate when to opt for a venous or an arterial blood gas analysis. Arterial punctures are more painful and carry a higher risk of complications

  15. Correlation dimension estimate and its potential use in analysis of gas-solid flows

    DEFF Research Database (Denmark)

    Yin, Chungen; Rosendahl, Lasse Aistrup; Kær, Søren Knudsen

    2005-01-01

    Gas-solid flows are nonlinear systems. Therefore state-space analysis, a tool developed within the framework of nonlinear dynamics, could provide more useful insights into complex gas-solid flows. One of the positive aspects of state-space analysis is that the major properties of a system can be ...

  16. Hepatopulmonary syndrome: which blood gas analysis criteria and position should we use for diagnosis?

    Science.gov (United States)

    Grilo, Israel; Pascasio, Juan Manuel; López-Pardo, Francisco-Jesús; Ortega-Ruiz, Francisco; Tirado, Juan Luis; Sousa, José Manuel; Rodríguez-Puras, María José; Ferrer, María Teresa; Gómez-Bravo, Miguel Ángel; Grilo, Antonio

    2017-10-03

    Different blood gas criteria have been used in the diagnosis of hepatopulmonary syndrome (HPS). Arterial blood gases were prospectively evaluated in 194 cirrhotic candidates for liver transplantation (LT) in the supine and seated position. Three blood gas criteria were analyzed: classic (partial pressure of oxygen [PaO2] blood gas measurements in the supine position and the use of modern criteria are more sensitive for the diagnosis of HPS. Blood gas analysis with the patient seated detects a greater number of severe and very severe cases. The presence of HPS was not associated with an increase in mortality regardless of blood gas criterion used.

  17. Can Liberalization Affect the Price of Gas Imports? A Theoretical Analysis of the EU Case.

    OpenAIRE

    Cavaliere, Alberto; Michelis, Stefano

    2012-01-01

    Common wisdom about the effects of gas market liberalization in the EU claims that the fragmentation of gas supply in the downstream market can raise the price of gas imports, as the bargaining power of European firms in the upstream market would be weakened. We consider such a claim from the point of view of economic theory, by analysing the effects of downstream competition on the upstream price of gas. Though our analysis is limited by the assumption of a single gas producer upstream, we c...

  18. Hollow Waveguide Gas Sensor for Mid-Infrared Trace Gas Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S; Young, C; Chan, J; Carter, C; Mizaikoff, B

    2007-07-12

    A hollow waveguide mid-infrared gas sensor operating from 1000 cm{sup -1} to 4000 cm{sup -1} has been developed, optimized, and its performance characterized by combining a FT-IR spectrometer with Ag/Ag-halide hollow core optical fibers. The hollow core waveguide simultaneously serves as a light guide and miniature gas cell. CH{sub 4} was used as test analyte during exponential dilution experiments for accurate determination of the achievable limit of detection (LOD). It is shown that the optimized integration of an optical gas sensor module with FT-IR spectroscopy provides trace sensitivity at the few hundreds of parts-per-billion concentration range (ppb, v/v) for CH{sub 4}.

  19. Rapid analysis of urinary opiates using fast gas chromatography–mass spectrometry and hydrogen as a carrier gas

    Directory of Open Access Journals (Sweden)

    Sumandeep Rana

    2014-09-01

    Gas chromatographic–mass spectrometric analysis was performed in electron ionization mode by selective ion monitoring, using hydrogen as a carrier gas, a short narrow bore GC capillary column, and fast temperature program, allowing for a rapid analytical cycle to maximize the instrument time for high throughput laboratories. While maintaining specificity for these drugs, concentrations in human urine ranging from 50 to 5,000 ng/mL can be measured with intraday and interday imprecision, expressed as variation coefficients, of less than 2.3% for all analytes within a run time of less than 3.5 minutes.

  20. Analysis and Comparison of Aluminum Alloy Welded Joints Between Metal Inert Gas Welding and Tungsten Inert Gas Welding

    Science.gov (United States)

    Zhao, Lei; Guan, Yingchun; Wang, Qiang; Cong, Baoqiang; Qi, Bojin

    2015-09-01

    Surface contamination usually occurs during welding processing and it affects the welds quality largely. However, the formation of such contaminants has seldom been studied. Effort was made to study the contaminants caused by metal inert gas (MIG) welding and tungsten inert gas (TIG) welding processes of aluminum alloy, respectively. SEM, FTIR and XPS analysis was carried out to investigate the microstructure as well as surface chemistry. These contaminants were found to be mainly consisting of Al2O3, MgO, carbide and chromium complexes. The difference of contaminants between MIG and TIG welds was further examined. In addition, method to minimize these contaminants was proposed.

  1. Screening of Gas-Cooled Reactor Thermal-Hydraulic and Safety Analysis Tools and Experimental Database

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Jae; Kim, Min Hwan; Lee, Seung Wook (and others)

    2007-08-15

    This report is a final report of I-NERI Project, 'Screening of Gas-cooled Reactor Thermal Hydraulic and Safety Analysis Tools and Experimental Database 'jointly carried out by KAERI, ANL and INL. In this study, we developed the basic technologies required to develop and validate the VHTR TH/safety analysis tools and evaluated the TH/safety database information. The research tasks consist of; 1) code qualification methodology (INL), 2) high-level PIRTs for major nucleus set of events (KAERI, ANL, INL), 3) initial scaling and scoping analysis (ANL, KAERI, INL), 4) filtering of TH/safety tools (KAERI, INL), 5) evaluation of TH/safety database information (KAERI, INL, ANL) and 6) key scoping analysis (KAERI). The code qualification methodology identifies the role of PIRTs in the R and D process and the bottom-up and top-down code validation methods. Since the design of VHTR is still evolving, we generated the high-level PIRTs referencing 600MWth block-type GT-MHR and 400MWth pebble-type PBMR. Nucleus set of events that represents the VHTR safety and operational transients consists of the enveloping scenarios of HPCC (high pressure conduction cooling: loss of primary flow), LPCC/Air-Ingress (low pressure conduction cooling: loss of coolant), LC (load changes: power maneuvering), ATWS (anticipated transients without scram: reactivity insertion), WS (water ingress: water-interfacing system break) and HU (hydrogen-side upset: loss of heat sink). The initial scaling analysis defines dimensionless parameters that need to be reflected in mixed convection modeling and the initial scoping analysis provided the reference system transients used in the PIRTs generation. For the PIRTs phenomena, we evaluated the modeling capability of the candidate TH/safety tools and derived a model improvement need. By surveying and evaluating the TH/safety database information, a tools V and V matrix has been developed. Through the key scoping analysis using available database, the

  2. Gas migration through cement slurries analysis: A comparative laboratory study

    Directory of Open Access Journals (Sweden)

    Arian Velayati

    2015-12-01

    Full Text Available Cementing is an essential part of every drilling operation. Protection of the wellbore from formation fluid invasion is one of the primary tasks of a cement job. Failure in this task results in catastrophic events, such as blow outs. Hence, in order to save the well and avoid risky and operationally difficult remedial cementing, slurry must be optimized to be resistant against gas migration phenomenon. In this paper, performances of the conventional slurries facing gas invasion were reviewed and compared with modified slurry containing special gas migration additive by using fluid migration analyzer device. The results of this study reveal the importance of proper additive utilization in slurry formulations. The rate of gas flow through the slurry in neat cement is very high; by using different types of additives, we observe obvious changes in the performance of the cement system. The rate of gas flow in neat class H cement was reported as 36000 ml/hr while the optimized cement formulation with anti-gas migration and thixotropic agents showed a gas flow rate of 13.8 ml/hr.

  3. On-line non-contact gas analysis

    DEFF Research Database (Denmark)

    Fateev, Alexander; Clausen, Sønnik

    Non-intrusive and fast measurements of the gas temperature, NO and other gas concentrations at elevated temperatures in boilers, engines and flames are of the great interest. The optical properties of the gases must be known in a spectral range and temperature level of interest. High-resolution IR......, and good agreement has been found for NO (e.g. deviations of 1-5% for NO at 1200 °C). Practical highresolution measurements at the AVV2 boiler are analysed, and detection limits for the NO are discussed. The developed tools and results will be used in the future projects, e.g. fast measurements of the gas...

  4. Characteristic Value Method of Well Test Analysis for Horizontal Gas Well

    Directory of Open Access Journals (Sweden)

    Xiao-Ping Li

    2014-01-01

    Full Text Available This paper presents a study of characteristic value method of well test analysis for horizontal gas well. Owing to the complicated seepage flow mechanism in horizontal gas well and the difficulty in the analysis of transient pressure test data, this paper establishes the mathematical models of well test analysis for horizontal gas well with different inner and outer boundary conditions. On the basis of obtaining the solutions of the mathematical models, several type curves are plotted with Stehfest inversion algorithm. For gas reservoir with closed outer boundary in vertical direction and infinite outer boundary in horizontal direction, while considering the effect of wellbore storage and skin effect, the pseudopressure behavior of the horizontal gas well can manifest four characteristic periods: pure wellbore storage period, early vertical radial flow period, early linear flow period, and late horizontal pseudoradial flow period. For gas reservoir with closed outer boundary both in vertical and horizontal directions, the pseudopressure behavior of the horizontal gas well adds the pseudosteady state flow period which appears after the boundary response. For gas reservoir with closed outer boundary in vertical direction and constant pressure outer boundary in horizontal direction, the pseudopressure behavior of the horizontal gas well adds the steady state flow period which appears after the boundary response. According to the characteristic lines which are manifested by pseudopressure derivative curve of each flow period, formulas are developed to obtain horizontal permeability, vertical permeability, skin factor, reservoir pressure, and pore volume of the gas reservoir, and thus the characteristic value method of well test analysis for horizontal gas well is established. Finally, the example study verifies that the new method is reliable. Characteristic value method of well test analysis for horizontal gas well makes the well test analysis

  5. Oxyanion induced variations in domain structure for amorphous cobalt oxide oxygen evolving catalysts, resolved by X-ray pair distribution function analysis.

    Science.gov (United States)

    Kwon, Gihan; Kokhan, Oleksandr; Han, Ali; Chapman, Karena W; Chupas, Peter J; Du, Pingwu; Tiede, David M

    2015-12-01

    Amorphous thin film oxygen evolving catalysts, OECs, of first-row transition metals show promise to serve as self-assembling photoanode materials in solar-driven, photoelectrochemical `artificial leaf' devices. This report demonstrates the ability to use high-energy X-ray scattering and atomic pair distribution function analysis, PDF, to resolve structure in amorphous metal oxide catalyst films. The analysis is applied here to resolve domain structure differences induced by oxyanion substitution during the electrochemical assembly of amorphous cobalt oxide catalyst films, Co-OEC. PDF patterns for Co-OEC films formed using phosphate, Pi, methylphosphate, MPi, and borate, Bi, electrolyte buffers show that the resulting domains vary in size following the sequence Pi < MPi < Bi. The increases in domain size for CoMPi and CoBi were found to be correlated with increases in the contributions from bilayer and trilayer stacked domains having structures intermediate between those of the LiCoOO and CoO(OH) mineral forms. The lattice structures and offset stacking of adjacent layers in the partially stacked CoMPi and CoBi domains were best matched to those in the LiCoOO layered structure. The results demonstrate the ability of PDF analysis to elucidate features of domain size, structure, defect content and mesoscale organization for amorphous metal oxide catalysts that are not readily accessed by other X-ray techniques. PDF structure analysis is shown to provide a way to characterize domain structures in different forms of amorphous oxide catalysts, and hence provide an opportunity to investigate correlations between domain structure and catalytic activity.

  6. Analysis of factors affecting gas exchange in intravascular blood gas exchanger.

    Science.gov (United States)

    Niranjan, S C; Clark, J W; San, K Y; Zwischenberger, J B; Bidani, A

    1994-10-01

    A mathematical model of an intravascular hollow-fiber gas-exchange device, called IVOX, has been developed using a Krogh cylinder-like approach with a repeating unit structure comprised of a single fiber with gas flowing through its lumen surrounded by a coaxial cylinder of blood flowing in the opposite direction. Species mass balances on O2 and CO2 result in a nonlinear coupled set of convective-diffusion parabolic partial differential equations that are solved numerically using an alternating-direction implicit finite-difference method. Computed results indicated the presence of a large resistance to gas transport on the external (blood) side of the hollow-fiber exchanger. Increasing gas flow through the device favored CO2 removal from but not O2 addition to blood. Increasing blood flow over the device favored both CO2 removal as well as O2 addition. The rate of CO2 removal increased linearly with the transmural PCO2 gradient imposed across the device. The effect of fiber crimping on blood phase mass transfer resistance was evaluated indirectly by varying species blood diffusivity. Computed results indicated that CO2 excretion by IVOX can be significantly enhanced with improved bulk mixing of vena caval blood around the IVOX fibers.

  7. Analysis of fifty year Gas Flaring Emissions from oil/gas companies in Africa

    Science.gov (United States)

    Doumbia, E. H. T.; Liousse, C.; Granier, L.; Granier, C.; Rosset, R.; Oda, T.; Hsu, F. C.

    2014-12-01

    Flaring is a process during which waste gases are burned in an open atmosphere. The quantification of gas flaring emissions represents a major scientific concern due to its magnitude and related uncertainties. In global/regional emission inventories, this source, though releasing large amounts of pollutants in the atmosphere, is still poorly quantified if not missing. It can represent the main emission source of gaseous compounds and particles in some areas, as observed during the AMMA project in the Gulf of Guinea. Our study focuses on Africa, and includes Nigeria, which is one of the largest natural oil and gas reserve in the world. Africa is an important gas flaring area, since technologies for the exploitation of this energy source and the reduction of flaring activities have been only recently implemented. We have developed an emission inventory for gases and particles from flaring in Africa. We have first compiled the few published available dataset of fuel consumption from flaring. The spatial distribution of CO2 and black carbon (BC) emissions from gas flaring in 2011 is estimated using a methodology based on field reports and remote sensing (DMSP satellite data). Our results point out to the importance of flaring activities into the regional anthropogenic emissions in Africa over the period 1960-2011. Finally, the contribution of flaring to total anthropogenic emission can be large and needs to be accurately quantified.

  8. Production Optimization for Plan of Gas Field Development Using Marginal Cost Analysis

    Directory of Open Access Journals (Sweden)

    Suprapto Soemardan

    2013-09-01

    Full Text Available Gas production rate is one of the most important variables affecting the feasibility plan of gas field development. It take into account reservoir characteristics, gas reserves, number of wells, production facilities, government take and market conditions. In this research, a mathematical  model of gas production optimization  has been developed using  marginal cost  analysis  in  determining  the  optimum  gas  production  rate  for  economic  profit,  by employing  the  case  study  of Matindok  Field.  The  results  show  that  the  optimum  gas  production  rate  is  mainly  affected  by  gas  price  duration  and time of gas delivery. When the price of gas  increases, the optimum  gas production rate  will increase, and then it  will become closer to the maximum production rate of the reservoir. Increasing the duration time of gas delivery will reduce the optimum gas production rate and increase maximum profit non-linearly.

  9. Thermal Analysis of the Divertor Primary Heat Transfer System Piping During the Gas Baking Process

    Energy Technology Data Exchange (ETDEWEB)

    Yoder Jr, Graydon L [ORNL; Harvey, Karen [ORNL; Ferrada, Juan J [ORNL

    2011-02-01

    A preliminary analysis has been performed examining the temperature distribution in the Divertor Primary Heat Transfer System (PHTS) piping and the divertor itself during the gas baking process. During gas baking, it is required that the divertor reach a temperature of 350 C. Thermal losses in the piping and from the divertor itself require that the gas supply temperature be maintained above that temperature in order to ensure that all of the divertor components reach the required temperature. The analysis described in this report was conducted in order to estimate the required supply temperature from the gas heater.

  10. Analysis of regenerative thermal storage geometries for solar gas turbines

    CSIR Research Space (South Africa)

    Klein, P

    2014-08-01

    Full Text Available Ceramic heat regenerators are suited to providing thermal storage for concentrating solar power stations based on a recuperated gas turbine cycle. Randomly packed beds of spheres and saddles; honeycombs and checker bricks were identified...

  11. Evolvable Neural Software System

    Science.gov (United States)

    Curtis, Steven A.

    2009-01-01

    The Evolvable Neural Software System (ENSS) is composed of sets of Neural Basis Functions (NBFs), which can be totally autonomously created and removed according to the changing needs and requirements of the software system. The resulting structure is both hierarchical and self-similar in that a given set of NBFs may have a ruler NBF, which in turn communicates with other sets of NBFs. These sets of NBFs may function as nodes to a ruler node, which are also NBF constructs. In this manner, the synthetic neural system can exhibit the complexity, three-dimensional connectivity, and adaptability of biological neural systems. An added advantage of ENSS over a natural neural system is its ability to modify its core genetic code in response to environmental changes as reflected in needs and requirements. The neural system is fully adaptive and evolvable and is trainable before release. It continues to rewire itself while on the job. The NBF is a unique, bilevel intelligence neural system composed of a higher-level heuristic neural system (HNS) and a lower-level, autonomic neural system (ANS). Taken together, the HNS and the ANS give each NBF the complete capabilities of a biological neural system to match sensory inputs to actions. Another feature of the NBF is the Evolvable Neural Interface (ENI), which links the HNS and ANS. The ENI solves the interface problem between these two systems by actively adapting and evolving from a primitive initial state (a Neural Thread) to a complicated, operational ENI and successfully adapting to a training sequence of sensory input. This simulates the adaptation of a biological neural system in a developmental phase. Within the greater multi-NBF and multi-node ENSS, self-similar ENI s provide the basis for inter-NBF and inter-node connectivity.

  12. Numerical analysis of a microwave torch with axial gas injection

    Energy Technology Data Exchange (ETDEWEB)

    Gritsinin, S. I.; Davydov, A. M.; Kossyi, I. A., E-mail: kossyi@fpl.gpi.ru [Russian Academy of Sciences, Prokhorov General Physics Institute (Russian Federation); Kulumbaev, E. B. [National Research University Belgorod State University (Russian Federation); Lelevkin, V. M. [Kyrgyz-Russian Slavic University (Kyrgyzstan)

    2013-07-15

    The characteristics of a microwave discharge in an argon jet injected axially into a coaxial channel with a shortened inner electrode are numerically analyzed using a self-consistent equilibrium gas-dynamic model. The specific features of the excitation and maintenance of the microwave discharge are determined, and the dependences of the discharge characteristics on the supplied electromagnetic power and gas flow rate are obtained. The calculated results are compared with experimental data.

  13. Optimal Energy Consumption Analysis of Natural Gas Pipeline

    OpenAIRE

    Liu, Enbin; Li, Changjun; Yang, Yi

    2014-01-01

    There are many compressor stations along long-distance natural gas pipelines. Natural gas can be transported using different boot programs and import pressures, combined with temperature control parameters. Moreover, different transport methods have correspondingly different energy consumptions. At present, the operating parameters of many pipelines are determined empirically by dispatchers, resulting in high energy consumption. This practice does not abide by energy reduction policies. There...

  14. Offsite Radiological Consequence Analysis for the Bounding Flammable Gas Accident

    CERN Document Server

    Carro, C A

    2003-01-01

    This document quantifies the offsite radiological consequences of the bounding flammable gas accident for comparison with the 25 rem Evaluation Guideline established in DOE-STD-3009, Appendix A. The bounding flammable gas accident is a detonation in a single-shell tank The calculation applies reasonably conservation input parameters in accordance with DOE-STD-3009, Appendix A, guidance. Revision 1 incorporates comments received from Office of River Protection.

  15. Geological evolution and analysis of confirmed or suspected gas hydrate localities: Volume 13: Basin analysis, formation and stability of gas hydrates of the Nankai Trough: Topical report

    Energy Technology Data Exchange (ETDEWEB)

    Ciesnik, M.; Krason, J.

    1989-05-01

    Geological factors controlling the formation, stability, and distribution of gas hydrates were investigated by basin analysis of the Nankai Trough region. The Nankai Trough is located beneath the western Pacific, south of the Japanese islands Shikoku and central Kyushu. Geological, geophysical, and geochemical data from the region were assembled and critically evaluated to develop consistent interpretations of the relationships of geological environments and gas hydrates. This study was performed for the US Department of Energy Morgantown Energy Technology Center by Geoexplorers International, Inc., as part of a worldwide evaluation of 21 offshore sites where the presence of gas hydrates has been confirmed or inferred. 60 refs., 26 figs., 1 tab.

  16. An integrated approach for gas dispersion, gas explosion and structural impact analysis for an offshore production platform on the Dutch continental shelf

    NARCIS (Netherlands)

    Korndörffer, W.; Schaap, D.; Heijden, A.M.A. van der; Versloot, N.H.A.

    2004-01-01

    The design of an offshore gas production platform has been subjected to an extensive quantitative risk analysis in particular with regard to its resistance to gas explosions loads. It was demonstrated that integration of the physical and structural effects of a gas explosion in an early stage of the

  17. Regional frequency analysis using Growing Neural Gas network

    Science.gov (United States)

    Abdi, Amin; Hassanzadeh, Yousef; Ouarda, Taha B. M. J.

    2017-07-01

    The delineation of hydrologically homogeneous regions is an important issue in regional hydrological frequency analysis. In the present study, an application of the Growing Neural Gas (GNG) network for hydrological data clustering is presented. The GNG is an incremental and unsupervised neural network, which is able to adapt its structure during the training procedure without using a prior knowledge of the size and shape of the network. In the GNG algorithm, the Minimum Description Length (MDL) measure as the cluster validity index is utilized for determining the optimal number of clusters (sub-regions). The capability of the proposed algorithm is illustrated by regionalizing drought severities for 40 synoptic weather stations in Iran. To fulfill this aim, first a clustering method is applied to form the sub-regions and then a heterogeneity measure is used to test the degree of heterogeneity of the delineated sub-regions. According to the MDL measure and considering two different indices namely CS and Davies-Bouldin (DB) in the GNG network, the entire study area is subdivided in two sub-regions located in the eastern and western sides of Iran. In order to evaluate the performance of the GNG algorithm, a number of other commonly used clustering methods, like K-means, fuzzy C-means, self-organizing map and Ward method are utilized in this study. The results of the heterogeneity measure based on the L-moments approach reveal that only the GNG algorithm successfully yields homogeneous sub-regions in comparison to the other methods.

  18. New Jersey's natural gas shortage: a policy analysis

    Energy Technology Data Exchange (ETDEWEB)

    Cecil, J.L.; Morell, D.

    1976-12-01

    The public policy problems associated with New Jersey's natural gas shortage are extremely complex and rather difficult to examine. They involve a blend of technology, politics and economics; of regulatory mandates and profit-motivated initiatives; of Federal and state interaction and conflict. To understand the state's gas shortage and to lay the basis for recommending measures to deal with it, information about the basic technology, the organization of the gas industry, the national regulatory posture, and the possible causes of the gas shortage encompasses Part I of the overall study. In Part II, the analysis turns from the national level to a direct examination of New Jersey's gas situation. In Part III, Chapter VIII, the following are considered: the state's supply of natural gas, distribution of these supply volumes within New Jersey by the four major gas utilities, and gas consumption patterns within the state as a whole and then for each major consuming sector (electric utility, industrial, commercial, and residential). This chapter concludes with an analysis of the impacts of the gas shortage to date in New Jersey, and of its probable effects in the near-term. In the final chapter, some tentative conclusions and broad suggestions are advanced for public policies to mitigate the gravity of the state's position with respect to natural gas. Analysis proceeds, in turn, through consideration of possible state actions in several areas: increasing total interstate gas supplies; increasing New Jersey's share of whatever national total exists; making greater (or more effective) use of alternate fuels; and moderating demand for gas through aggressive conservation policies. Some short-term measures to cope better with whatever level of gas shortage exists in the state at any particular time are suggested. 151 references. (MCW)

  19. The analysis of the possible thermal emission at radio frequencies from an evolved supernova remnant HB 3 (G132.7+1.3: Revisited

    Directory of Open Access Journals (Sweden)

    Onić D.

    2008-01-01

    Full Text Available It has recently been reported that some of the flux density values for an evolved supernova remnant (SNR HB 3 (G132.7+1.3 are not accurate enough. In this work we therefore revised the analysis of the possible thermal emission at radio frequencies from this SNR using the recently published, corrected flux density values. A model including the sum of non-thermal (purely synchrotron and thermal (bremsstrahlung components is applied to fit the integrated radio spectrum of this SNR. The contribution of thermal component to the total volume emissivity at 1 GHz is estimated to be ≈ 37%. The ambient density is also estimated to be n ≈ 9 cm-3 for T = 104 K. Again we obtained a relatively significant presence of thermal emission at radio frequencies from the SNR, which can support interaction between SNR HB 3 and adjacent molecular cloud associated with the H ii region W3. Our model estimates for thermal component contribution to total volume emissivity at 1 GHz and ambient density are similar to those obtained earlier (≈ 40 %, ≈ 10 cm-3 . It is thus obvious that the corrected flux density values do not affect the basic conclusions.

  20. The Analysis of the Possible Thermal Emission at Radio Frequencies from an Evolved Supernova Remnant HB 3 (G132.7+1.3: Revisited

    Directory of Open Access Journals (Sweden)

    Onić, D.

    2008-12-01

    Full Text Available It has recently been reported that some of the flux density values for an evolved supernova remnant (SNR HB 3 (G132.7$+$1.3 are not accurate enough. In this work we therefore revised the analysis of the possible thermal emission at radio frequencies from this SNR using the recently published, corrected flux density values. A model including the sum of non-thermal (purely synchrotron and thermal (bremsstrahlung components is applied to fit the integrated radio spectrum of this SNR. The contribution of thermal component to the total volume emissivity at $1 mathrm{GHz}$ is estimated to be $approx37 \\%$. The ambient density is also estimated to be $napprox 9 mathrm{cm}^{-3}$ for $mathrm{T}=10^{4} mathrm{K}$. Again we obtained a relatively significant presence of thermal emission at radio frequencies from the SNR, which can support interaction between SNR HB 3 and adjacent molecular cloud associated with the mbox{H,{sc ii}} region W3. Our model estimates for thermal component contribution to total volume emissivity at $1 mathrm{GHz}$ and ambient density are similar to those obtained earlier ($approx40 \\%$, $approx10 mathrm{cm^{-3}}$. It is thus obvious that the corrected flux density values do not affect the basic conclusions.

  1. Analysis of temperature and pressure changes in liquefied natural gas (LNG) cryogenic tanks

    Science.gov (United States)

    Chen, Q.-S.; Wegrzyn, J.; Prasad, V.

    2004-10-01

    Liquefied natural gas (LNG) is being developed as a transportation fuel for heavy vehicles such as trucks and transit buses, to lessen the dependency on oil and to reduce greenhouse gas emissions. The LNG stations are properly designed to prevent the venting of natural gas (NG) from LNG tanks, which can cause evaporative greenhouse gas emissions and result in fluctuations of fuel flow and changes of fuel composition. Boil-off is caused by the heat added into the LNG fuel during the storage and fueling. Heat can leak into the LNG fuel through the shell of tank during the storage and through hoses and dispensers during the fueling. Gas from tanks onboard vehicles, when returned to LNG tanks, can add additional heat into the LNG fuel. A thermodynamic and heat transfer model has been developed to analyze different mechanisms of heat leak into the LNG fuel. The evolving of properties and compositions of LNG fuel inside LNG tanks is simulated. The effect of a number of buses fueled each day on the possible total fuel loss rate has been analyzed. It is found that by increasing the number of buses, fueled each day, the total fuel loss rate can be reduced significantly. It is proposed that an electric generator be used to consume the boil-off gas or a liquefier be used to re-liquefy the boil-off gas to reduce the tank pressure and eliminate fuel losses. These approaches can prevent boil-off of natural gas emissions, and reduce the costs of LNG as transportation fuel.

  2. An alternative methodology for the analysis of electrical resistivity data from a soil gas study

    OpenAIRE

    Johansson, Sara; Rosqvist, Hakan; Svensson, Mats; Dahlin, Torleif; Leroux, Virginie

    2011-01-01

    The aim of this paper is to present an alternative method for the analysis of resistivity data. The methodology was developed during a study to evaluate if electrical resistivity can be used as a tool for analysing subsurface gas dynamics and gas emissions from landfills. The main assumption of this study was that variations in time of resistivity data correspond to variations in the relative amount of gas and water in the soil pores. Field measurements of electrical resistivity, static chamb...

  3. Teaching Risk Analysis in an Aircraft Gas Turbine Engine Design Capstone Course

    Science.gov (United States)

    2016-01-01

    American Institute of Aeronautics and Astronautics 1 Teaching Risk Analysis in an Aircraft Gas Turbine Engine Design Capstone Course...5 from the contempory Level of Technology 4. The design point for this example is a supercruise mission leg at Mach 1.5 and altitude of 36,000 feet...Gas Turbine Engine Course. Feb 2012, ASME Journal of Engineering for Gas Turbines and Power , Vol. 134, pp. 021601-1. Byerley, Aaron R., Rolling

  4. Pore-Scale Simulation and Sensitivity Analysis of Apparent Gas Permeability in Shale Matrix.

    Science.gov (United States)

    Zhang, Pengwei; Hu, Liming; Meegoda, Jay N

    2017-01-25

    Extremely low permeability due to nano-scale pores is a distinctive feature of gas transport in a shale matrix. The permeability of shale depends on pore pressure, porosity, pore throat size and gas type. The pore network model is a practical way to explain the macro flow behavior of porous media from a microscopic point of view. In this research, gas flow in a shale matrix is simulated using a previously developed three-dimensional pore network model that includes typical bimodal pore size distribution, anisotropy and low connectivity of the pore structure in shale. The apparent gas permeability of shale matrix was calculated under different reservoir pressures corresponding to different gas exploitation stages. Results indicate that gas permeability is strongly related to reservoir gas pressure, and hence the apparent permeability is not a unique value during the shale gas exploitation, and simulations suggested that a constant permeability for continuum-scale simulation is not accurate. Hence, the reservoir pressures of different shale gas exploitations should be considered. In addition, a sensitivity analysis was also performed to determine the contributions to apparent permeability of a shale matrix from petro-physical properties of shale such as pore throat size and porosity. Finally, the impact of connectivity of nano-scale pores on shale gas flux was analyzed. These results would provide an insight into understanding nano/micro scale flows of shale gas in the shale matrix.

  5. Characterizing Environmental Transformation of Multi-walled Carbon Nanotubes and Carbon Nano-Fiber Composites using Thermal Analysis and Related Hyphenated Techniques

    Science.gov (United States)

    Thermogravimetric analysis (TGA) coupled with gas chromatography and mass spectroscopy (TGA/GCMS), for the evolved gas analysis, has given insight to the stability and kinetics of structural changes and determining adsorbed organics to nanomaterials and nanocomposites. TGA is als...

  6. Energy Factor Analysis for Gas Heat Pump Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Gluesenkamp, Kyle R [ORNL

    2016-01-01

    Gas heat pump water heaters (HPWHs) can improve water heating efficiency with zero GWP and zero ODP working fluids. The energy factor (EF) of a gas HPWH is sensitive to several factors. In this work, expressions are derived for EF of gas HPWHs, as a function of heat pump cycle COP, tank heat losses, burner efficiency, electrical draw, and effectiveness of supplemental heat exchangers. The expressions are used to investigate the sensitivity of EF to each parameter. EF is evaluated on a site energy basis (as used by the US DOE for rating water heater EF), and a primary energy-basis energy factor (PEF) is also defined and included. Typical ranges of values for the six parameters are given. For gas HPWHs, using typical ranges for component performance, EF will be 59 80% of the heat pump cycle thermal COP (for example, a COP of 1.60 may result in an EF of 0.94 1.28). Most of the reduction in COP is due to burner efficiency and tank heat losses. Gas-fired HPWHs are theoretically be capable of an EF of up to 1.7 (PEF of 1.6); while an EF of 1.1 1.3 (PEF of 1.0 1.1) is expected from an early market entry.

  7. Steady State Structural Analysis of High Pressure Gas Turbine Blade using Finite Element Analysis

    Science.gov (United States)

    Mazarbhuiya, Hussain Mahamed Sahed Mostafa; Murari Pandey, Krishna

    2017-08-01

    In gas turbines the major portion of performance dependency lies upon turbine blade design. Turbine blades experience very high centrifugal, axial and tangential force during power generation. While withstanding these forces blades undergo elongation. Different methods have proposed for better enhancement of the mechanical properties of blade to withstand in extreme condition. Present paper describes the stress and elongation for blades having properties of different materials. Steady state structural analysis have performed in the present work for different materials (In 625, In 718, In 738, In 738 LC, MAR M246, Ni-Cr, Ti-alloy, Ti-Al, Ti-T6, U500). Remarkable finding is that the root of the blade is subjected to maximum stress for all blade materials and the blade made of MAR M246 has less stress and deformation among all other blade materials which can be selected as a suitable material for gas turbine blade.

  8. Cleaner flue gas and energy recovery through pinch analysis

    Energy Technology Data Exchange (ETDEWEB)

    Zhelev, T.K.; Semkov, K.A. [University of Durban Westville, Durban (South Africa). Dept. of Chemical Engineering

    2004-07-01

    The paper addresses the problems of cleaner energy generation in industrial applications. Its aims further flue gas energy recovery accompanied with additional environmental impact. It shows how the widely accepted flue gas temperature of industrial coal fired boilers can be lowered substantially without increasing the risk of back-end condensation. This is possible through dehumidification and partial absorption of the flue gas in a packed-bed economiser system by circulating water. Different design contact economiser systems (CES) are presented and compared. Pinch principles are deployed for targeting, design and operation-guiding purposes, balancing the heat and mass transfer in a second generation CES of parallel type. The results are expected to make these systems more sophisticated and more suitable for industrial applications.

  9. Analysis of the gas diffusion process during a hypothetical air ingress accident in a modular high temperature gas cooled reactor

    OpenAIRE

    Zhang, Z.; Gerwin, Helmut; Scherer, Winfried

    1993-01-01

    In order to simulate the diffusion process during a hypothetical air ingress accident in a modular high temperature gas cooled reactor, a one-dimensional coupled diffusion-convection model has been established. In this analysis it is shown first, that experiments performed at the Japan Atomic Energy Research Institute (JAERI) have been recalculated successfully, thus validating the new model. Applying this model to the NACOK facility, now under construction at the Institute for Safety Researc...

  10. Ultraviolet spectroscopic breath analysis using hollow-optical fiber as gas cell

    Science.gov (United States)

    Iwata, T.; Katagiri, T.; Matsuura, Y.

    2017-02-01

    For breath analysis on ultraviolet absorption spectroscopy, an analysis system using a hollow optical fiber as gas cell is developed. The hollow optical fiber functions as a long path and extremely small volume gas cell. Firstly, the measurement sensitivity of the system is evaluated by using NO gas as a gas sample. The result shows that NO gas with 50 ppb concentration is measured by using a system with a laser-driven, high intensity light source and a 3-meter long, aluminum-coated hollow optical fiber. Then an absorption spectrum of breath sample is measured in the wavelength region of around 200-300 nm and from the spectrum, it is found that the main absorbing components in breath were H2O, isoprene, and O3 converted from O2 by radiation of ultraviolet light. Then the concentration of isoprene in breath is estimated by using multiple linear regression analysis.

  11. Analysis of engineering cycles power, refrigerating and gas liquefaction plant

    CERN Document Server

    Haywood, R W

    1991-01-01

    Extensively revised, updated and expanded, the fourth edition of this popular text provides a rigorous analytical treatment of modern energy conversion plant. Notable for both its theoretical and practical treatment of conventional and nuclear power plant, and its studies of refrigerating and gas-liquefaction plant. This fourth edition now includes material on topics of increasing concern in the fields of energy 'saving' and reduction of environmental pollution. This increased coverage deals specifically with the following areas: CHP (cogeneration) plant, studies of both gas and coal burning p

  12. Gas adsorption and desorption effects on high pressure small volume cylinders and their relevance to atmospheric trace gas analysis

    Science.gov (United States)

    Satar, Ece; Nyfeler, Peter; Pascale, Céline; Niederhauser, Bernhard; Leuenberger, Markus

    2017-04-01

    Long term atmospheric monitoring of trace gases requires great attention to precision and accuracy of the measurement setups. For globally integrated and well established greenhouse gas observation networks, the World Meteorological Organization (WMO) has set recommended compatibility goals within the framework of its Global Atmosphere Watch (GAW) Programme [1]. To achieve these challenging limits, the measurement systems are regularly calibrated with standard gases of known composition. Therefore, the stability of the primary and secondary gas standards over time is an essential issue. Past studies have explained the small instabilities in high pressure standard gas cylinders through leakage, diffusion, regulator effects, gravimetric fractionation and surface processes [2, 3]. The latter include adsorption/desorption, which are functions of temperature, pressure and surface properties. For high pressure standard gas mixtures used in atmospheric trace gas analysis, there exists only a limited amount of data and few attempts to quantify the surface processes [4, 5]. Specifically, we have designed a high pressure measurement chamber to investigate trace gases and their affinity for adsorption on different surfaces over various temperature and pressure ranges. Here, we focus on measurements of CO2, CH4 and CO using a cavity ring down spectroscopy analyzer and quantify the concentration changes due to adsorption/desorption. In this study, the first results from these prototype cylinders of steel and aluminum will be presented. References [1] World Meteorological Organization (WMO), Global Atmosphere Watch.(GAW): Report No. 229, 18th WMO/IAEA Meeting on Carbon Dioxide, Other Greenhouse Gases and Related Tracers Measurement Techniques (GGMT-2015), 2016. [2] Keeling, R. F., Manning, A. C., Paplawsky, W. J., and Cox, A. C.: On the long-term stability of reference gases for atmospheric O2 /N2 and CO2 measurements, Tellus B, 59, 10.3402/tellusb.v59i1.16964, 2007. [3

  13. Radial artery pseudoaneurysm: A rare complication after a single arterial puncture for blood-gas analysis.

    Science.gov (United States)

    Patel, Kajal Nitin; Gandhi, Shruti P; Sutariya, Harsh C

    2016-10-01

    With a reported incidence of 0.048%, radial artery pseudoaneurysm (PA) is a rare but serious complication of arterial cannulation. We report a case of PA developing after a single puncture of the right radial artery for arterial blood-gas analysis diagnosed by Doppler ultrasound in young male patient. The development of PA after puncture of radial artery for continuous blood pressure monitoring and serial blood-gas analysis has been reported in the past; however, to the best of our knowledge, there is only one case report of development of PA after a single arterial puncture for blood-gas analysis is reported in the past.

  14. An experimental setup with ultrasonic gas analyzers and real time analysis of the composition of a binary gas mixture

    Directory of Open Access Journals (Sweden)

    Doubek M.

    2013-04-01

    Full Text Available This paper describes an automated measuring apparatus with an ultrasonic gas analyzer and realtime analysis of the composition of the gas. The apparatus is designed for preparing binary gas mixtures and making measurements in a wide range of pressures (from 0.8 bara to 15 bara and temperatures (between -15°C and 80°C. The apparatus was developed to determine the thermophysical properties of fluorocarbon mixtures for potential use in the cooling circuits of several Large Hadron Collider projects at CERN. The design of its control system took into account the safety and reliability o the gas analyzer, and the need to limit the presence of laboratory personnel. The control system was implemented in PVSS-II, the Supervisory, Control and Data Acquisition standard chosen for LHC and its experiments at CERN. The second part of the paper describes the implementation and verification of the algorithm for continuous real-time determination of the composition of the refrigerant mixture. The algorithm is based on minimizing the quadratic norm fromthe measured data and from the pre-generated look-up tables acquired from the NIST REFPROP software package.

  15. Gas stream analysis using voltage-current time differential operation of electrochemical sensors

    Energy Technology Data Exchange (ETDEWEB)

    Woo, Leta Yar-Li; Glass, Robert Scott; Fitzpatrick, Joseph Jay; Wang, Gangqiang; Henderson, Brett Tamatea; Lourdhusamy, Anthoniraj; Steppan, James John; Allmendinger, Klaus Karl

    2018-01-02

    A method for analysis of a gas stream. The method includes identifying an affected region of an affected waveform signal corresponding to at least one characteristic of the gas stream. The method also includes calculating a voltage-current time differential between the affected region of the affected waveform signal and a corresponding region of an original waveform signal. The affected region and the corresponding region of the waveform signals have a sensitivity specific to the at least one characteristic of the gas stream. The method also includes generating a value for the at least one characteristic of the gas stream based on the calculated voltage-current time differential.

  16. Gas Chromatography-Mass Spectrometric Analysis of Nematicidal ...

    African Journals Online (AJOL)

    by gas chromatography-mass spectrometry by comparison of their retention indices with those published in the literature or with those of authentic compounds available in our laboratories. The retention indices were determined in relation to a homologous series of n-alkanes (C8–C24) under the same operating conditions.

  17. Modular approach to analysis of chemically recuperated gas turbine cycles

    Energy Technology Data Exchange (ETDEWEB)

    Carcasci, C.; Facchini, B. [University of Florence, `Sergio Stecco` (Italy). Dept. of Energy Engineering; Harvey, S. [Chalmers Institute of Technology, Goeteberg (Sweden). Dept. of Heat and Power Technology

    1998-12-31

    Current research programmes such as the CAGT programme investigate the opportunity for advanced power generation cycles based on state-of-the-art aeroderivative gas turbine technology. Such cycles would be primarily aimed at intermediate duty applications. Compared to industrial gas turbines, aeroderivatives offer high simple cycle efficiency, and the capability to start quickly and frequently without a significant maintenance cost penalty. A key element for high system performance is the development of improved heat recovery systems, leading to advanced cycles such as the humid air turbine (HAT) cycle, the chemically recuperated gas turbine (CRGT) cycle and the Kalina combined cycle. When used in combination with advanced technologies and components, screening studies conducted by research programmes such as the CAGT programme predict that such advanced cycles could theoretically lead to net cycle efficiencies exceeding 60%. In this paper, the authors present the application of the modular approach to cycle simulation and performance predictions of CRGT cycles. The paper first presents the modular simulation code concept and the main characteristics of CRGT cycles. The paper next discusses the development of the methane-steam reformer unit model used for the simulations. The modular code is then used to compute performance characteristics of a simple CRGT cycle and a reheat CRGT cycle, both based on the General Electric LM6000 aeroderivative gas turbine. (author)

  18. Undisplayed Bicarbonate ion Concentration in Arterial Blood Gas Analysis

    OpenAIRE

    Sathe, Aditya Balakrishna; Bhalkar, Manjiri Shashank

    2013-01-01

    Blood bicarbonate ion concentration (BcHCO3-) is a vital parameter in the management of acid base disorders. In an arterial blood gas (ABG) analyzer, the BcHCO3- is calculated from the values of pH and pCO2.

  19. On-line non-contact gas analysis

    Energy Technology Data Exchange (ETDEWEB)

    Fateev, A.; Clausen, Soennik

    2008-03-15

    Non-intrusive and fast measurements of the gas temperature, NO and other gas concentrations at elevated temperatures in boilers, engines and flames are of the great interest. The optical properties of the gases must be known in a spectral range and temperature level of interest. High-resolution IR- and UV-absorption spectra of the NO have been measured with a hot gas cell operated from the ambient up to 1400-1500 deg. C. Similarly, high-resolution infrared absorption spectra of the H{sub 2}O have been measured. Measurements are compared with simulated spectra using the HITRAN-2006 and HITEMP-1996 databases, and good agreement has been found for NO (e.g. deviations of 1-5% for NO at 1200 deg. C). practical high-resolution measurements at the AVV2 boiler are analysed, and detection limits for the NO are discussed. The developed tools and results will be used in the future projects, e.g. fast measurements of the gas composition in the near-burner field with co-firing of biomass and coal, and NO measurements in a large diesel engine. (au)

  20. Analysis of essential oils by gas chromatography and mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Masada, Y.

    1976-01-01

    The book is in two parts: first part Essential Oil includes compositae; labiatae; verbenaceae; oleaceae; umbelliferae; myrtaceae; euphorbiaceae; rutaceae; geraniaceae; rosaceae; lauraceae; myristicaceae; anonaceae; santalaceae; moraceae; piperaceae; zingiberaceae; araceae; gramineae; and cupressaceae written in English and Japanese. Part two includes essential oil; gas chromatography, and mass spectrometry written in Japanese. (DP)

  1. Methods to optimize myxobacterial fermentations using off-gas analysis

    Directory of Open Access Journals (Sweden)

    Hüttel Stephan

    2012-05-01

    Full Text Available Abstract Background The influence of carbon dioxide and oxygen on microbial secondary metabolite producers and the maintenance of these two parameters at optimal levels have been studied extensively. Nevertheless, most studies have focussed on their influence on specific product formation and condition optimization of established processes. Considerably less attention has been paid to the influence of reduced or elevated carbon dioxide and oxygen levels on the overall metabolite profiles of the investigated organisms. The synergistic action of both gases has garnered even less attention. Results We show that the composition of the gas phase is highly important for the production of different metabolites and present a simple approach that enables the maintenance of defined concentrations of both O2 and CO2 during bioprocesses over broad concentration ranges with a minimal instrumental setup by using endogenously produced CO2. The metabolite profiles of a myxobacterium belonging to the genus Chondromyces grown under various concentrations of CO2 and O2 showed considerable differences. Production of two unknown, highly cytotoxic compounds and one antimicrobial substance was found to increase depending on the gas composition. In addition, the observation of CO2 and O2 in the exhaust gas allowed optimization and control of production processes. Conclusions Myxobacteria are becoming increasingly important due to their potential for bioactive secondary metabolite production. Our studies show that the influence of different gas partial pressures should not be underestimated during screening processes for novel compounds and that our described method provides a simple tool to investigate this question.

  2. Accessibility analysis as an urban planning tool: Gas station location

    NARCIS (Netherlands)

    Escobar, D.; Cadena-Gaitán, C.; Garcia, F.

    2014-01-01

    We apply geo-statistical techniques to find relationships between the geographic location of urban "Gas Stations" (GS) and operational features offered by the transport network in Manizales (Colombia). This research is built upon primary information collected during a period longer than one year

  3. Continuous analysis of nitrogen dioxide in gas streams of plants

    Science.gov (United States)

    Durkin, W. T.; Kispert, R. C.

    1969-01-01

    Analyzer and sampling system continuously monitors nitrogen dioxide concentrations in the feed and tail gas streams of a facility recovering nitric acid. The system, using a direct calorimetric approach, makes use of readily available equipment and is flexible and reliable in operation.

  4. Risk Analysis using Corrosion Rate Parameter on Gas Transmission Pipeline

    Science.gov (United States)

    Sasikirono, B.; Kim, S. J.; Haryadi, G. D.; Huda, A.

    2017-05-01

    In the oil and gas industry, the pipeline is a major component in the transmission and distribution process of oil and gas. Oil and gas distribution process sometimes performed past the pipeline across the various types of environmental conditions. Therefore, in the transmission and distribution process of oil and gas, a pipeline should operate safely so that it does not harm the surrounding environment. Corrosion is still a major cause of failure in some components of the equipment in a production facility. In pipeline systems, corrosion can cause failures in the wall and damage to the pipeline. Therefore it takes care and periodic inspections or checks on the pipeline system. Every production facility in an industry has a level of risk for damage which is a result of the opportunities and consequences of damage caused. The purpose of this research is to analyze the level of risk of 20-inch Natural Gas Transmission Pipeline using Risk-based inspection semi-quantitative based on API 581 associated with the likelihood of failure and the consequences of the failure of a component of the equipment. Then the result is used to determine the next inspection plans. Nine pipeline components were observed, such as a straight pipes inlet, connection tee, and straight pipes outlet. The risk assessment level of the nine pipeline’s components is presented in a risk matrix. The risk level of components is examined at medium risk levels. The failure mechanism that is used in this research is the mechanism of thinning. Based on the results of corrosion rate calculation, remaining pipeline components age can be obtained, so the remaining lifetime of pipeline components are known. The calculation of remaining lifetime obtained and the results vary for each component. Next step is planning the inspection of pipeline components by NDT external methods.

  5. Strategic analysis on establishing a natural gas trading hub in China

    Directory of Open Access Journals (Sweden)

    Xiaoguang Tong

    2014-12-01

    Full Text Available Since 2010, the LNG importing price premium in the Asia–Pacific markets has become increasingly high, generating great effects on the economic development in China. In addition, the natural gas dependence degree is expanding continuously, making it extremely urgent to establish a natural gas trading hub in China, with the aim to ensure national energy security, to gain the pricing power, and to build the regional benchmark prices. Through a comparative analysis of internal strength/weakness and external competitiveness, we concluded that with intensively-issued supporting policies on the natural gas sector, the initiation of spot and futures markets, the rapid growth of gas production and highly-improved infrastructures, as well as Shanghai's advantageous location, China has more advantages in establishing an Asian Natural Gas Trading Hub than other counties like Singapore, Japan and Malaysia. Moreover, based on the SWOT (strength, weakness, opportunity and threat and the marketization process analysis, the following strategies were presented: to impel the establishment of a natural gas trading hub depending on the gas supply condition, to follow the policies to complete the gas storage system, to form regional communities by taking comparative advantages, and to reinforce the marketization reform and regulation system establishment with foreign experiences for reference. This study rationalized the necessity and practicality of establishing a natural gas trading hub in China and will help China make a proper decision and find a periodical strategic path in this sector.

  6. Unique problems associated with seismic analysis of partially gas-saturated unconsolidated sediments

    Science.gov (United States)

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

    2009-01-01

    Gas hydrate stability conditions restrict the occurrence of gas hydrate to unconsolidated and high water-content sediments at shallow depths. Because of these host sediments properties, seismic and well log data acquired for the detection of free gas and associated gas hydrate-bearing sediments often require nonconventional analysis. For example, a conventional method of identifying free gas using the compressional/shear-wave velocity (Vp/Vs) ratio at the logging frequency will not work, unless the free-gas saturations are more than about 40%. The P-wave velocity dispersion of partially gas-saturated sediments causes a problem in interpreting well log velocities and seismic data. Using the White, J.E. [1975. Computed seismic speeds and attenuation in rocks with partial gas saturation. Geophysics 40, 224-232] model for partially gas-saturated sediments, the difference between well log and seismic velocities can be reconciled. The inclusion of P-wave velocity dispersion in interpreting well log data is, therefore, essential to identify free gas and to tie surface seismic data to synthetic seismograms.

  7. Angiostrongylosis-related restrictive pneumopathy assessed by arterial blood gas analysis in a dog.

    Science.gov (United States)

    Csöndes, Judit; Majoros, Gábor; Lajos, Zoltán; Psáder, Roland; Vajdovich, Péter; Manczur, Ferenc; Máthé, Ákos

    2015-03-01

    Pulmonary angiostrongylosis was diagnosed by the Baermann method and larval identification from faecal and bronchoalveolar lavage samples in a five-month- old male mongrel dog with dyspnoea and cough. Arterial blood gas analysis indicated arterial hypoxaemia and restrictive pneumopathy. In addition to the palliative treatment, fenbendazole was administered (50 mg/kg/24 h per os) for 14 days. The respiratory signs subsided within a short time clinically, but serial arterial blood gas analysis demonstrated an ongoing ventilation disorder. Repeated haematology, thoracic radiography, bronchoscopy and blood gas analysis were performed to follow the course of the disease. The most severe eosinophilia was detected after the beginning of the anthelmintic therapy, and the arterial pO2 level was permanently low. Arterial blood gas analysis provided the most adequate information about the course of the pneumopathy and it greatly facilitated the patient's medical management.

  8. Analysis of chemical signals in red fire ants by gas chromatography and pattern recognition techniques

    Science.gov (United States)

    The combination of gas chromatography and pattern recognition (GC/PR) analysis is a powerful tool for investigating complicated biological problems. Clustering, mapping, discriminant development, etc. are necessary to analyze realistically large chromatographic data sets and to seek meaningful relat...

  9. A rapid analysis of plasma/serum ethylene and propylene glycol by headspace gas chromatography

    National Research Council Canada - National Science Library

    Ehlers, Alexandra; Morris, Cory; Krasowski, Matthew D

    2013-01-01

    A rapid headspace-gas chromatography (HS-GC) method was developed for the analysis of ethylene glycol and propylene glycol in plasma and serum specimens using 1,3-propanediol as the internal standard...

  10. Characterisation of odorants in roasted stem tea using gas chromatography-mass spectrometry and gas chromatography-olfactometry analysis.

    Science.gov (United States)

    Sasaki, Tetsuya; Koshi, Erina; Take, Harumi; Michihata, Toshihide; Maruya, Masachika; Enomoto, Toshiki

    2017-04-01

    Roasted stem tea has a characteristic flavour, which is obtained by roasting tea stems, by-product of green tea production. This research aims to understand the characteristic odorants in roasted stem tea by comparing it to roasted leaf tea. We revealed potent odorants in commercial roasted stem tea using gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry with aroma extract dilution analysis (AEDA). The difference between roasted stem and leaf tea derived from the same tea plants were investigated using GC-MS. Pyrazine compounds exhibited a roasted odour and high flavour dilution (FD) factors, as determined via AEDA. Roasted stem tea was richer in these pyrazines than roasted leaf tea. Geraniol and linalool exhibited high FD factors and a floral odour, and roasted stem tea was richer in these compounds than roasted leaf tea. These results may have a positive impact on the development of tea products. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Gas turbine cooling modeling - Thermodynamic analysis and cycle simulations

    Energy Technology Data Exchange (ETDEWEB)

    Jordal, Kristin

    1999-02-01

    Considering that blade and vane cooling are a vital point in the studies of modern gas turbines, there are many ways to include cooling in gas turbine models. Thermodynamic methods for doing this are reviewed in this report, and, based on some of these methods, a number of model requirements are set up and a Cooled Gas Turbine Model (CGTM) for design-point calculations of cooled gas turbines is established. Thereafter, it is shown that it is possible to simulate existing gas turbines with the CGTM. Knowledge of at least one temperature in the hot part of the turbine (TET, TRIT or possibly TIT) is found to be vital for a complete heat balance over the turbine. The losses, which are caused by the mixing of coolant and main flow, are in the CGTM considered through a polytropic efficiency reduction factor S. Through the study of S, it can be demonstrated that there is more to gain from coolant reduction in a small and/or old turbine with poor aerodynamics, than there is to gain in a large, modern turbine, where the losses due to interaction between coolant and main flow are, relatively speaking, small. It is demonstrated, at the design point (TET=1360 deg C, {pi}=20) for the simple-cycle gas turbine, that heat exchanging between coolant and fuel proves to have a large positive impact on cycle efficiency, with an increase of 0.9 percentage points if all of the coolant passes through the heat exchanger. The corresponding improvement for humidified coolant is 0.8 percentage points. A design-point study for the HAT cycle shows that if all of the coolant is extracted after the humidification tower, there is a decrease in coolant requirements of 7.16 percentage points, from 19.58% to 12.52% of the compressed air, and an increase in thermal efficiency of 0.46 percentage points, from 53.46% to 53.92%. Furthermore, it is demonstrated with a TET-parameter variation, that the cooling of a simple-cycle gas turbine with humid air can have a positive effect on thermal efficiency

  12. Application of quantum cascade lasers to trace gas analysis

    Science.gov (United States)

    Kosterev, A.; Wysocki, G.; Bakhirkin, Y.; So, S.; Lewicki, R.; Fraser, M.; Tittel, F.; Curl, R. F.

    2008-02-01

    Quantum cascade (QC) lasers are virtually ideal mid-infrared sources for trace gas monitoring. They can be fabricated to operate at any of a very wide range of wavelengths from ˜ 3 μm to ˜ 24 μm. Seizing the opportunity presented by mid-infrared QC lasers, several groups world-wide are actively applying them to trace gas sensing. Real world applications include environmental monitoring, industrial process control and biomedical diagnostics. In our laboratory we have explored the use of several methods for carrying out absorption spectroscopy with these sources, which include multipass absorption spectroscopy, cavity ring down spectroscopy (CRDS), integrated cavity output spectroscopy (ICOS), and quartz-enhanced photoacoustic spectroscopy (QEPAS).

  13. Arterialised earlobe blood gas analysis: an underused technique.

    OpenAIRE

    Pitkin, A. D.; Roberts, C.M.; Wedzicha, J A

    1994-01-01

    BACKGROUND--Techniques for sampling arterialised capillary blood from the finger pulp and the earlobe were first described over two decades ago but, although close agreement between arterial values and earlobe samples has been demonstrated in normal subjects, this technique is not in common usage. METHODS--Forty patients with chronic lung disease and a wide range of arterial blood gas values were studied. Simultaneous earlobe and arterial samples were drawn with the patient at rest and analys...

  14. Stability Analysis of High-Speed Boundary-Layer Flow with Gas Injection (Briefing Charts)

    Science.gov (United States)

    2014-06-01

    boundary-layer flow with gas injection 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER Alexander V. Fedorov ...Release; Distribution Unlimited Stability analysis of high-speed boundary-layer flow with gas injection Alexander Fedorov and Vitaly Soudakov Moscow...Dispersion relation from WKB analysis*,**: *Guschin, V.R., & Fedorov , A.V., Fluid Dynamics, Vol. 24, No.1, 1989 **Guschin, V.R., & Fedorov , A.V., NASA

  15. Smell of danger: an analysis of LP-gas odorization

    Energy Technology Data Exchange (ETDEWEB)

    Cain, W.S.; Turk, A.

    1985-03-01

    LP-gas derives warning properties from the odorants ethyl mercaptan or thiophane. Laboratory tests have implied that the average person has the ability to smell the odors before leaking LP-gas reaches one-fifth its lower limit of flammability. Generally, however, laboratory tests ignore or discard persons with a poor sense of smell, especially the elderly and persons with certain types of hyposmia. Some persons who apparently can smell the warning agents when directed may otherwise fail to notice or identify them. Elderly men seem particularly vulnerable to instances of incidental anosmia and olfactory agnosia. Psychophysical testing of the warning agents has been rather unsophisticated. There exists neither a standard protocol for testing nor adequate specification of the perceptual properties that might make one warning agent better than another. Without such developments, improvement in warning agents will fail to occur. Possible improvements include increases in concentration, the use of blends to insure more uniform delivery of agent and, to decrease the perceptual vulnerability of relatively insensitive people, use of agents with favorable psychophysical (stimulus-response) functions and use of agents with favorable adaptation characteristics. Even without a change in existing products, it seems advisable to learn more about the vulnerability of LP-gas users and to employ educational means to reduce risks.

  16. Optimal Energy Consumption Analysis of Natural Gas Pipeline

    Science.gov (United States)

    Liu, Enbin; Li, Changjun; Yang, Yi

    2014-01-01

    There are many compressor stations along long-distance natural gas pipelines. Natural gas can be transported using different boot programs and import pressures, combined with temperature control parameters. Moreover, different transport methods have correspondingly different energy consumptions. At present, the operating parameters of many pipelines are determined empirically by dispatchers, resulting in high energy consumption. This practice does not abide by energy reduction policies. Therefore, based on a full understanding of the actual needs of pipeline companies, we introduce production unit consumption indicators to establish an objective function for achieving the goal of lowering energy consumption. By using a dynamic programming method for solving the model and preparing calculation software, we can ensure that the solution process is quick and efficient. Using established optimization methods, we analyzed the energy savings for the XQ gas pipeline. By optimizing the boot program, the import station pressure, and the temperature parameters, we achieved the optimal energy consumption. By comparison with the measured energy consumption, the pipeline now has the potential to reduce energy consumption by 11 to 16 percent. PMID:24955410

  17. Residual gas analysis for long-pulse, advanced tokamak operation.

    Science.gov (United States)

    Klepper, C C; Hillis, D L; Bucalossi, J; Douai, D; Oddon, P; Vartanian, S; Colas, L; Manenc, L; Pégourié, B

    2010-10-01

    A shielded residual gas analyzer (RGA) system on Tore Supra can function during plasma operation and is set up to monitor the composition of the neutral gas in one of the pumping ducts of the toroidal pumped limited. This "diagnostic RGA" has been used in long-pulse (up to 6 min) discharges for continuous monitoring of up to 15 masses simultaneously. Comparison of the RGA-measured evolution of the H(2)/D(2) isotopic ratio in the exhaust gas to that measured by an energetic neutral particle analyzer in the plasma core provides a way to monitor the evolution of particle balance. RGA monitoring of corrective H(2) injection to maintain proper minority heating is providing a database for improved ion cyclotron resonance heating, potentially with RGA-base feedback control. In very long pulses (>4 min) absence of significant changes in the RGA-monitored, hydrocarbon particle pressures is an indication of proper operation of the actively cooled, carbon-based plasma facing components. Also H(2) could increase due to thermodesorption of overheated plasma facing components.

  18. Analysis of hollow fibre membrane systems for multicomponent gas separation

    KAUST Repository

    Khalilpour, Rajab

    2013-02-01

    This paper analysed the performance of a membrane system over key design/operation parameters. A computation methodology is developed to solve the model of hollow fibre membrane systems for multicomponent gas feeds. The model represented by a nonlinear differential algebraic equation system is solved via a combination of backward differentiation and Gauss-Seidel methods. Natural gas sweetening problem is investigated as a case study. Model parametric analyses of variables, namely feed gas quality, pressure, area, selectivity and permeance, resulted in better understanding of operating and design optima. Particularly, high selectivities and/or permeabilities are shown not to be necessary targets for optimal operation. Rather, a medium selectivity (<60 in the given example) combined with medium permeance (∼300-500×10-10mol/sm2Pa in the given case study) is more advantageous. This model-based membrane systems engineering approach is proposed for the synthesis of efficient and cost-effective multi-stage membrane networks. © 2012 The Institution of Chemical Engineers.

  19. Should blood gas analysis be part of the diagnostic workup of short children? Auxological data and blood gas analysis in children with renal tubular acidosis

    NARCIS (Netherlands)

    D. Mul (Dick); F.K. Grote (Floor); J.R. Goudriaan; S.M.P.F. de Muinck Keizer-Schrama (Sabine); J.M. Wit (Jan); W. Oostdijk (Wilma)

    2010-01-01

    textabstractBackground: Renal tubular acidosis (RTA) is a rare cause of growth failure, therefore it is uncertain whether routine screening with blood gas analysis of short infants and children is cost-effective. Objective: To investigate the clinical, growth and laboratory parameters in children

  20. Just fracking: a distributive environmental justice analysis of unconventional gas development in Pennsylvania, USA

    Science.gov (United States)

    Clough, Emily; Bell, Derek

    2016-02-01

    This letter presents a distributive environmental justice analysis of unconventional gas development in the area of Pennsylvania lying over the Marcellus Shale, the largest shale gas formation in play in the United States. The extraction of shale gas using unconventional wells, which are hydraulically fractured (fracking), has increased dramatically since 2005. As the number of wells has grown, so have concerns about the potential public health effects on nearby communities. These concerns make shale gas development an environmental justice issue. This letter examines whether the hazards associated with proximity to wells and the economic benefits of shale gas production are fairly distributed. We distinguish two types of distributive environmental justice: traditional and benefit sharing. We ask the traditional question: are there a disproportionate number of minority or low-income residents in areas near to unconventional wells in Pennsylvania? However, we extend this analysis in two ways: we examine income distribution and level of education; and we compare before and after shale gas development. This contributes to discussions of benefit sharing by showing how the income distribution of the population has changed. We use a binary dasymetric technique to remap the data from the 2000 US Census and the 2009-2013 American Communities Survey and combine that data with a buffer containment analysis of unconventional wells to compare the characteristics of the population living nearer to unconventional wells with those further away before and after shale gas development. Our analysis indicates that there is no evidence of traditional distributive environmental injustice: there is not a disproportionate number of minority or low-income residents in areas near to unconventional wells. However, our analysis is consistent with the claim that there is benefit sharing distributive environmental injustice: the income distribution of the population nearer to shale gas wells

  1. Evolving cellular automata to perform computations. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Crutchfield, J.P.; Mitchell, M.

    1998-04-01

    The overall goals of the project are to determine the usefulness of genetic algorithms (GAs) in designing spatially extended parallel systems to perform computational tasks and to develop theoretical frameworks both for understanding the computation in the systems evolved by the GA and for understanding the evolutionary process which successful systems are designed. In the original proposal the authors scheduled the first year of the project to be devoted to experimental grounding. During the first year they developed the simulation and graphics software necessary for doing experiments and analysis on one dimensional cellular automata (CAs), and they performed extensive experiments and analysis concerning two computational tasks--density classification and synchronization. Details of these experiments and results, and a list of resulting publications, were given in the 1994--1995 report. The authors scheduled the second year to be devoted to theoretical development. (A third year, to be funded by the National Science Foundation, will be devoted to applications.) Accordingly, most of the effort during the second year was spent on theory, both of GAs and of the CAs that they evolve. A central notion is that of the computational strategy of a CA, which they formalize in terms of domains, particles, and particle interactions. This formalization builds on the computational mechanics framework developed by Crutchfield and Hanson for understanding intrinsic computation in spatially extended dynamical systems. They have made significant progress in the following areas: (1) statistical dynamics of GAs; (2) formalizing particle based computation in cellular automata; and (3) computation in two-dimensional CAs.

  2. [When is a venous blood gas analysis sufficient in the emergency department?

    Science.gov (United States)

    van Exsel, J A J M; Simons, S O; Kramers, C; Heijdra, Y F

    2017-01-01

    Blood gas analysis plays an important role in the initial assessment of a patient in the emergency ward. We present three different patient cases to illustrate when to opt for a venous or an arterial blood gas analysis. Arterial punctures are more painful and carry a higher risk of complications compared to venous punctures. It is possible to use a venous blood gas to screen for acute acid/base disturbances. Ventilatory compensation or anion gap cannot be calculated reliably with a venous blood gas. On the other hand, the diagnosis diabetic keto-acidosis can be made with a venous blood gas; this mode of sampling can also be used for lactate measurement at the emergency department as an independent prognostic marker for mortality. Venous blood gas analyses are not able to assess oxygenation. Pulse oximetry is a non-invasive alternative for arterial blood gas sampling. The use of a venous blood gas to assess a patient's ventilation is limited, whereas it can be used to diagnose carbomonoxide intoxication or methaemoglobinaemia.

  3. Technical and Feasibility Analysis of Gasoline and Natural Gas Fuelled Vehicles

    Directory of Open Access Journals (Sweden)

    Charalambos Chasos

    2014-03-01

    Full Text Available There is recent interest for the utilisation of natural gas for empowering the internal combustion engines (ICE of vehicles. The production of novel natural gas ICE for vehicles, as well as the conversion of existing gasoline fuelled ICE of vehicles to natural gas fuelled ICE are new technologies which require to be analysed and assessed. The objective of the present study is to examine the adaptation of natural gas as vehicle fuel and carry out a technical analysis and an economical feasibility analysis of the two types of ICE vehicles, namely gasoline and natural gas fuelled vehicles. The technical model uses the physical properties of the two fuels and the performance factors of internal combustion engines including brake thermal efficiency. The resulting exhaust gas emissions are also estimated by the technical model using combustion calculations which provide the expected levels of exhaust gas emissions. Based on the analysis with the technical model, comparisons of the two types of engines are performed. Furthermore, the estimated performance characteristics of the two types of engines, along with local statistical data on annual fuel imports and annual fuel consumption for transportation and data on the vehicles fleet for the case study of Cyprus are used as input in the economical model. For the base year 2013, data of natural gas price is also used in the economical model. The economical model estimates the capital cost, the carbon dioxide emissions avoidance of fines, the net present value and the internal rate of return of the investment of large scale adaptation of natural gas fuelled vehicles for the case study. From the results and comparisons, conclusions are drawn and recommendations are provided for the adaptation of natural gas vehicles which can provide improved performance with reduced pollutant emissions.

  4. [Analysis of naphtha vapors in the air by gas chromatography].

    Science.gov (United States)

    Starek, A; Golba, W

    1984-01-01

    The paper is aimed at the development of a method for determining kerosene vapours in air by gas chromatography. Optimum parameters of kerosenes chromatographic separation and conditions for air sampling were determined. In addition, coefficient of the desorption of kerosene hydrocarbons from charcoal at which they were adsorbed, was determined. The quantitative interpretation of chromatograms was based on the measurement of the peak height of dodecane (C12), which constitutes 10.9% of the preparation mass per cent. The determinability of the method amounts to 60 mg/cm3 for kerosene vapours, with +/- 3,23% precision.

  5. Gas chromatographic analysis of trace impurities in chlorine trifluoride.

    Science.gov (United States)

    Laurens, J B; Swinley, J M; de Coning, J P

    2000-03-24

    The gas chromatographic determination of trace gaseous impurities in highly reactive fluorinated gaseous matrices presents unique requirements to both equipment and techniques. Especially problematic are the gases normally present in ambient air namely oxygen and nitrogen. Analysing these gases at the low microl/l (ppm) level requires special equipment and this publication describes a custom-designed system utilising backflush column switching to protect the columns and detectors. A thermal conductivity detector with nickel filaments was used to determine ppm levels of impurities in ClF3.

  6. Design and characterization of a Raman-scattering-based sensor system for temporally resolved gas analysis and its application in a gas turbine power plant

    Science.gov (United States)

    Kiefer, J.; Seeger, T.; Steuer, S.; Schorsch, S.; Weikl, M. C.; Leipertz, A.

    2008-08-01

    A sensor system for fast gas composition analysis is presented. Using linear Raman scattering the simultaneous detection of virtually all components of fuel gas mixtures such as natural gas and biogas can be achieved. The system consists of commercially available hardware components, in detail a frequency doubled continuous wave laser at 532 nm and a compact spectrometer with an embedded charge coupled device chip. For the evaluation of the Raman spectra a fast software module based on a contour fit algorithm is developed. Moreover, modules for controlling the hardware components are implemented in the sensor software ensuring simple operability of the entire system. In this paper the sensor is characterized in terms of, e.g., accuracy, reproducibility, detection limits and temporal performance. Finally its application for natural gas analysis in a gas turbine power plant is demonstrated, and the results obtained are compared to gas chromatography results.

  7. Fat: an evolving issue

    Directory of Open Access Journals (Sweden)

    John R. Speakman

    2012-09-01

    Work on obesity is evolving, and obesity is a consequence of our evolutionary history. In the space of 50 years, we have become an obese species. The reasons why can be addressed at a number of different levels. These include separating between whether the primary cause lies on the food intake or energy expenditure side of the energy balance equation, and determining how genetic and environmental effects contribute to weight variation between individuals. Opinion on whether increased food intake or decreased energy expenditure drives the obesity epidemic is still divided, but recent evidence favours the idea that food intake, rather than altered expenditure, is most important. There is more of a consensus that genetics explains most (probably around 65% of weight variation between individuals. Recent advances in genome-wide association studies have identified many polymorphisms that are linked to obesity, yet much of the genetic variance remains unexplained. Finding the causes of this unexplained variation will be an impetus of genetic and epigenetic research on obesity over the next decade. Many environmental factors – including gut microbiota, stress and endocrine disruptors – have been linked to the risk of developing obesity. A better understanding of gene-by-environment interactions will also be key to understanding obesity in the years to come.

  8. Evolving Concepts of Asthma

    Science.gov (United States)

    Ray, Anuradha; Wenzel, Sally E.

    2015-01-01

    Our understanding of asthma has evolved over time from a singular disease to a complex of various phenotypes, with varied natural histories, physiologies, and responses to treatment. Early therapies treated most patients with asthma similarly, with bronchodilators and corticosteroids, but these therapies had varying degrees of success. Similarly, despite initial studies that identified an underlying type 2 inflammation in the airways of patients with asthma, biologic therapies targeted toward these type 2 pathways were unsuccessful in all patients. These observations led to increased interest in phenotyping asthma. Clinical approaches, both biased and later unbiased/statistical approaches to large asthma patient cohorts, identified a variety of patient characteristics, but they also consistently identified the importance of age of onset of disease and the presence of eosinophils in determining clinically relevant phenotypes. These paralleled molecular approaches to phenotyping that developed an understanding that not all patients share a type 2 inflammatory pattern. Using biomarkers to select patients with type 2 inflammation, repeated trials of biologics directed toward type 2 cytokine pathways saw newfound success, confirming the importance of phenotyping in asthma. Further research is needed to clarify additional clinical and molecular phenotypes, validate predictive biomarkers, and identify new areas for possible interventions. PMID:26161792

  9. Evolving endoscopic surgery.

    Science.gov (United States)

    Sakai, Paulo; Faintuch, Joel

    2014-06-01

    Since the days of Albukasim in medieval Spain, natural orifices have been regarded not only as a rather repugnant source of bodily odors, fluids and excreta, but also as a convenient invitation to explore and treat the inner passages of the organism. However, surgical ingenuity needed to be matched by appropriate tools and devices. Lack of technologically advanced instrumentation was a strong deterrent during almost a millennium until recent decades when a quantum jump materialized. Endoscopic surgery is currently a vibrant and growing subspecialty, which successfully handles millions of patients every year. Additional opportunities lie ahead which might benefit millions more, however, requiring even more sophisticated apparatuses, particularly in the field of robotics, artificial intelligence, and tissue repair (surgical suturing). This is a particularly exciting and worthwhile challenge, namely of larger and safer endoscopic interventions, followed by seamless and scarless recovery. In synthesis, the future is widely open for those who use together intelligence and creativity to develop new prototypes, new accessories and new techniques. Yet there are many challenges in the path of endoscopic surgery. In this new era of robotic endoscopy, one will likely need a virtual simulator to train and assess the performance of younger doctors. More evidence will be essential in multiple evolving fields, particularly to elucidate whether more ambitious and complex pathways, such as intrathoracic and intraperitoneal surgery via natural orifice transluminal endoscopic surgery (NOTES), are superior or not to conventional techniques. © 2014 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.

  10. Asymmetric evolving random networks

    Science.gov (United States)

    Coulomb, S.; Bauer, M.

    2003-10-01

    We generalize the Poissonian evolving random graph model of M. Bauer and D. Bernard (2003), to deal with arbitrary degree distributions. The motivation comes from biological networks, which are well-known to exhibit non Poissonian degree distributions. A node is added at each time step and is connected to the rest of the graph by oriented edges emerging from older nodes. This leads to a statistical asymmetry between incoming and outgoing edges. The law for the number of new edges at each time step is fixed but arbitrary. Thermodynamical behavior is expected when this law has a large time limit. Although (by construction) the incoming degree distributions depend on this law, this is not the case for most qualitative features concerning the size distribution of connected components, as long as the law has a finite variance. As the variance grows above 1/4, the average being < 1/2, a giant component emerges, which connects a finite fraction of the vertices. Below this threshold, the distribution of component sizes decreases algebraically with a continuously varying exponent. The transition is of infinite order, in sharp contrast with the case of static graphs. The local-in-time profiles for the components of finite size allow to give a refined description of the system.

  11. Evolving a photosynthetic organelle

    Directory of Open Access Journals (Sweden)

    Nakayama Takuro

    2012-04-01

    Full Text Available Abstract The evolution of plastids from cyanobacteria is believed to represent a singularity in the history of life. The enigmatic amoeba Paulinella and its 'recently' acquired photosynthetic inclusions provide a fascinating system through which to gain fresh insight into how endosymbionts become organelles. The plastids, or chloroplasts, of algae and plants evolved from cyanobacteria by endosymbiosis. This landmark event conferred on eukaryotes the benefits of photosynthesis - the conversion of solar energy into chemical energy - and in so doing had a huge impact on the course of evolution and the climate of Earth 1. From the present state of plastids, however, it is difficult to trace the evolutionary steps involved in this momentous development, because all modern-day plastids have fully integrated into their hosts. Paulinella chromatophora is a unicellular eukaryote that bears photosynthetic entities called chromatophores that are derived from cyanobacteria and has thus received much attention as a possible example of an organism in the early stages of organellogenesis. Recent studies have unlocked the genomic secrets of its chromatophore 23 and provided concrete evidence that the Paulinella chromatophore is a bona fide photosynthetic organelle 4. The question is how Paulinella can help us to understand the process by which an endosymbiont is converted into an organelle.

  12. Cycle analysis of MCFC/gas turbine system

    Science.gov (United States)

    Musa, Abdullatif; Alaktiwi, Abdulsalam; Talbi, Mosbah

    2017-11-01

    High temperature fuel cells such as the solid oxide fuel cell (SOFC) and the molten carbonate fuel cell (MCFC) are considered extremely suitable for electrical power plant application. The molten carbonate fuel cell (MCFC) performances is evaluated using validated model for the internally reformed (IR) fuel cell. This model is integrated in Aspen Plus™. Therefore, several MCFC/Gas Turbine systems are introduced and investigated. One of this a new cycle is called a heat recovery (HR) cycle. In the HR cycle, a regenerator is used to preheat water by outlet air compressor. So the waste heat of the outlet air compressor and the exhaust gases of turbine are recovered and used to produce steam. This steam is injected in the gas turbine, resulting in a high specific power and a high thermal efficiency. The cycles are simulated in order to evaluate and compare their performances. Moreover, the effects of an important parameters such as the ambient air temperature on the cycle performance are evaluated. The simulation results show that the HR cycle has high efficiency.

  13. Trash to Gas (TtG) Simulant Analysis

    Science.gov (United States)

    Miles, John D., II; Hintze, Paul E.

    2014-01-01

    Space exploration in outer earths orbit is a long-term commitment, where the reuse of discarded materials is a critical component for its success. The Logistics Reduction and Repurposing (LRR) project under the NASA Advanced Exploration System Program is a project focused on technologies that reduce the amount of consumables that are needed to be sent into space, repurpose items sent to space, or convert wastes to commodities. In particular, Trash to Gas (TtG), part of the LRR project, is a novel space technology capable of converting raw elements from combustible waste including food waste and packaging, paper, wipes and towels, nitrile gloves, fecal matter, urine brine, maximum absorbency garments, and other organic wastes from human space exploration into useful gases. Trash to gas will ultimately reduce mission cost by producing a portion of important consumables in situ. This paper will discuss results of waste processing by steam reforming. Steam reforming is a thermochemical process developed as part of TtG, where waste is heated in the presence of oxygen and steam to produce carbon dioxide, carbon monoxide, hydrogen, methane and water. The aim of this experiment is to investigate the processing of different waste simulants and their gaseous products. This will lay a foundation for understating and optimizing the production of useful gases for propulsion and recovery of water for life support.

  14. Cycle analysis of MCFC/gas turbine system

    Directory of Open Access Journals (Sweden)

    Musa Abdullatif

    2017-01-01

    Full Text Available High temperature fuel cells such as the solid oxide fuel cell (SOFC and the molten carbonate fuel cell (MCFC are considered extremely suitable for electrical power plant application. The molten carbonate fuel cell (MCFC performances is evaluated using validated model for the internally reformed (IR fuel cell. This model is integrated in Aspen Plus™. Therefore, several MCFC/Gas Turbine systems are introduced and investigated. One of this a new cycle is called a heat recovery (HR cycle. In the HR cycle, a regenerator is used to preheat water by outlet air compressor. So the waste heat of the outlet air compressor and the exhaust gases of turbine are recovered and used to produce steam. This steam is injected in the gas turbine, resulting in a high specific power and a high thermal efficiency. The cycles are simulated in order to evaluate and compare their performances. Moreover, the effects of an important parameters such as the ambient air temperature on the cycle performance are evaluated. The simulation results show that the HR cycle has high efficiency.

  15. Integral Transport Analysis Results for Ions Flowing Through Neutral Gas

    Science.gov (United States)

    Emmert, Gilbert; Santarius, John

    2017-10-01

    Results of a computational model for the flow of energetic ions and neutrals through a background neutral gas will be presented. The method models reactions as creating a new source of ions or neutrals if the energy or charge state of the resulting particle is changed. For a given source boundary condition, the creation and annihilation of the various species is formulated as a 1-D Volterra integral equation that can quickly be solved numerically by finite differences. The present work focuses on multiple-pass, 1-D ion flow through neutral gas and a nearly transparent, concentric anode and cathode pair in spherical, cylindrical, or linear geometry. This has been implemented as a computer code for atomic (3He, 3He +, 3He + +) and molecular (D, D2, D-, D +, D2 +, D3 +) ion and neutral species, and applied to modeling inertial-electrostatic connement (IEC) devices. The code yields detailed energy spectra of the various ions and energetic neutral species. Calculations for several University of Wisconsin IEC and ion implantation devices will be presented. Research supported by US Dept. of Homeland Security Grant 2015-DN-077-ARI095, Dept. of Energy Grant DE-FG02-04ER54745, and the Grainger Foundation.

  16. Detection of outliers in gas emissions from urban areas using functional data analysis.

    Science.gov (United States)

    Torres, J Martínez; Garcia Nieto, P J; Alejano, L; Reyes, A N

    2011-02-15

    In this work a solution for the problem of the detection of outliers in gas emissions in urban areas that uses functional data analysis is described. Different methodologies for outlier identification have been applied in air pollution studies, with gas emissions considered as vectors whose components are gas concentration values for each observation made. In our methodology we consider gas emissions over time as curves, with outliers obtained by a comparison of curves instead of vectors. The methodology, which is based on the concept of functional depth, was applied to the detection of outliers in gas omissions in the city of Oviedo and results were compared with those obtained using a conventional method based on a comparison of vectors. Finally, the advantages of the functional method are reported. Copyright © 2010 Elsevier B.V. All rights reserved.

  17. A Review on Innovative Procedures for the Analysis of Data from Gas Sensor Systems and Networks

    Directory of Open Access Journals (Sweden)

    Rolf Seifert

    2015-01-01

    Full Text Available Economic online and in-situ field analyses applications like discriminated alarming of smoldering fire or toxic gas leakages, monitoring of volatile components in chemical and biochemical processes, quality monitoring in food processing etc., wait for reliable and economic analytical solutions by sensor systems. This paper presents various innovative mathematical procedures to analyze data from gas sensor systems and gas sensor nets: ProSens - an efficient mathematical procedure for calibration and evaluation of tin oxide gas sensor data, SimSens – a mathematical program for simultaneous analysis of gases, ProCal - a program for batch-wise calibration of multi gas sensors and ProSource - a procedure for source localization. Applications to real data demonstrate the performance of the procedures.

  18. Dynamic Modeling and Analysis of an Industrial Gas Suspension Absorber for Flue Gas Desulfurization

    DEFF Research Database (Denmark)

    Cignitti, Stefano; Mansouri, Seyed Soheil; Sales-Cruz, Mauricio

    2016-01-01

    another plant data set. It was verified that in spite of the simplicity of the model, very good prediction of industrial behavior was obtained. Furthermore, the dynamic analysis of the system was performed by carrying out open-loop and closed-loop simulations to verify plant dynamics. Therefore, a simple...... parameters were fitted to operational data from a real cement plant. A detailed statistical analysis of the parameter estimation procedure was performed, and the confidence intervals for estimated kinetic parameters were calculated. The model and reaction rate expression prediction ability was tested using...

  19. A Driving Force Analysis and Forecast for Gas Consumption Demand in China

    Directory of Open Access Journals (Sweden)

    Qing Zhu

    2014-01-01

    Full Text Available In recent years, gas has begun to be widely used in power generation as well as in manufacturing because of the environmental advantages, lower cost, and the relative safety and reliability. Accurate prediction of future gas consumption is of great importance for energy security. In this paper, we first use path analysis to select the core factors that impact gas consumption, then use the RBF-QRNN model and BVAR model separately to predict future gas consumption, and finally discuss and compare the results from the two models. The results show that if there is a positive growth in GDP, urbanization, and population, then gas consumption is expected to increase over a comparatively long time. In detail, gas consumption is expected to remain at about 25% of all energy consumption, GDP’s contribution to gas consumption is expected to be about 53%, and the urbanization rate contribution would be about 15%. Gas consumption in China is predicted to reach around 178649.23 million cubic meters by the end of 2015 and about 264698.86 million cubic meters by 2020.

  20. Greenhouse gas emissions in Hawaii: Household and visitor expenditure analysis

    Energy Technology Data Exchange (ETDEWEB)

    Konan, Denise Eby, E-mail: konan@hawaii.ed [Department of Economics, Economic Research Organization, University of Hawaii at Manoa, Saunders Hall 542, Honolulu, HI 96822 (United States); Chan, H.L., E-mail: hingc@hawaii.ed [OmniTrak Group Inc., 1250 Davies Pacific Center, 841 Bishop Street, Honolulu, HI 96813 (United States)

    2010-01-15

    This paper focuses on petroleum use and greenhouse gas emissions associated with economic activities in Hawaii. Data on economic activity, petroleum consumption by type (gasoline, diesel, aviation fuel, residual, propane), and emissions factors are compiled and analyzed. In the baseline year 1997, emissions are estimated to total approximately 23.2 million metric tons of carbon, 181 thousand metric tons of nitrous oxide, and 31 thousand metric tons of methane in terms of carbon-equivalent global warming potential over a 100-year horizon. Air transportation, electricity, and other transportation are the key economic activity responsible for GHG emissions associated with fossil fuel use. More than 22% of total emissions are attributed to visitor expenditures. On a per person per annum basis, emission rates generated by visitor demand are estimated to be higher than that of residents by a factor of 4.3 for carbon, 3.2 for methane, and 4.8 for nitrous oxide.

  1. Greenhouse gas emissions in Hawaii. Household and visitor expenditure analysis

    Energy Technology Data Exchange (ETDEWEB)

    Konan, Denise Eby [Department of Economics, Economic Research Organization, University of Hawai' i at Manoa, Saunders Hall 542, Honolulu, HI 96822 (United States); Chan, Hing Ling [OmniTrak Group Inc., 1250 Davies Pacific Center, 841 Bishop Street, Honolulu, HI 96813 (United States)

    2010-01-15

    This paper focuses on petroleum use and greenhouse gas emissions associated with economic activities in Hawaii. Data on economic activity, petroleum consumption by type (gasoline, diesel, aviation fuel, residual, propane), and emissions factors are compiled and analyzed. In the baseline year 1997, emissions are estimated to total approximately 23.2 million metric tons of carbon, 181 thousand metric tons of nitrous oxide, and 31 thousand metric tons of methane in terms of carbon-equivalent global warming potential over a 100-year horizon. Air transportation, electricity, and other transportation are the key economic activity responsible for GHG emissions associated with fossil fuel use. More than 22% of total emissions are attributed to visitor expenditures. On a per person per annum basis, emission rates generated by visitor demand are estimated to be higher than that of residents by a factor of 4.3 for carbon, 3.2 for methane, and 4.8 for nitrous oxide. (author)

  2. Leakage analysis of fuel gas pipe in large LNG carrier engine room

    Directory of Open Access Journals (Sweden)

    CEN Zhuolun

    2017-10-01

    Full Text Available [Objectives] The electric propulsion dual-fuel engine is becoming dominant in newly built Liquefied Natural Gas(LNGcarriers. To avoid the potential risks that accompany the use of flammable and explosive boil-off gas,the performance of precise safety and reliability assessments is indispensable. [Methods] This research concerns the engine rooms of large LNG carriers which are propelled electrically by a dual-fuel engine. Possible fuel gas(natural gasleak cases in different areas of the engine room are simulated and analyzed. Five representative leak cases defined by leak form,leak location and leak rate are entered into a Computational Fluid Dynamics(CFDsimulation,in which the Reynolds stress model of Fluent software is adopted as the turbulence model. The results of the leaked gas distribution and ventilation velocity field are analyzed in combination to obtain the diffusion tendency and concentration distribution of leaked gas in different areas.[Results] Based on an analysis of the results,an optimized arrangement of flammable gas detectors is provided for the engine room, and the adoption of an explosion-proof exhaust fan is proven to be unnecessary.[Conclusions] These analysis methods can provide a reference for similar gas leakage scenarios occurring in confined ventilated spaces. In addition, the simulation results can be used to quantitatively assess potential fire or explosion damage in order to guide the design of structural reinforcements.

  3. Adapting Human Reliability Analysis from Nuclear Power to Oil and Gas Applications

    Energy Technology Data Exchange (ETDEWEB)

    Boring, Ronald Laurids [Idaho National Laboratory

    2015-09-01

    ABSTRACT: Human reliability analysis (HRA), as currently used in risk assessments, largely derives its methods and guidance from application in the nuclear energy domain. While there are many similarities be-tween nuclear energy and other safety critical domains such as oil and gas, there remain clear differences. This paper provides an overview of HRA state of the practice in nuclear energy and then describes areas where refinements to the methods may be necessary to capture the operational context of oil and gas. Many key distinctions important to nuclear energy HRA such as Level 1 vs. Level 2 analysis may prove insignifi-cant for oil and gas applications. On the other hand, existing HRA methods may not be sensitive enough to factors like the extensive use of digital controls in oil and gas. This paper provides an overview of these con-siderations to assist in the adaptation of existing nuclear-centered HRA methods to the petroleum sector.

  4. Modelling and analysis of offshore energy systems on North Sea oil and gas platforms

    DEFF Research Database (Denmark)

    Nguyen, Tuong-Van; Elmegaard, Brian; Pierobon, Leonardo

    2012-01-01

    export, and power generation. In this paper, a generic model of a North Sea oil and gas platform is described and the most thermodynamically inefficient processes are identified by performing an exergy analysis. Models and simulations are built and run with the tools Aspen Plus R, DNA and Aspen HYSYS R....... Results reveal that the total exergy destruction of the system is particularly sensitive to the gas-to-oil ratio and amounts to 55-65 MW, while the total exergy losses amount to 15-20 MW. The gas compression train and the production manifold module are the most exergy-destructive operations of the oil...

  5. A model-based analysis of the implications of shale gas developments for the European gas market

    Energy Technology Data Exchange (ETDEWEB)

    De Joode, J.; Plomp, A.J.; Ozdemir, O. [ECN Policy Studies, Petten (Netherlands)

    2012-04-15

    Shale gas in Europe could potentially be a big thing, especially in particular regions. Whereas test drillings need to confirm the technical recoverability of deposits and further research is needed on the environmental and safety aspects of shale gas production, this paper illustrates that shale gas developments may have substantial implications for regional gas balances, gas flows, and infrastructure requirements throughout Europe in the next decades.

  6. Stability Analysis of High-Speed Boundary-Layer Flow with Gas Injection

    Science.gov (United States)

    2014-06-01

    boundary-layer flow with gas injection 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER Alexander V. Fedorov ...distribution unlimited Stability analysis of high-speed boundary-layer flow with gas injection Alexander V. Fedorov * and Vitaly G. Soudakov...Laminar Flow, AGARD Report Number 709, 1984. 2. Fedorov , A., “Transition and Stability of High-Speed Boundary Layers,” Annu. Rev. Fluid Mech., Vol

  7. Earlobe arterialized capillary blood gas analysis in the intensive care unit: a pilot study

    OpenAIRE

    Vaquer, Sergi; Masip, Jordi; Gili, Gisela; Gomà, Gemma; Oliva, Joan Carles; Frechette, Alexandre; Evetts, Simon; Russomano, Thais; Artigas, Antonio

    2014-01-01

    Background Earlobe arterialized capillary blood gas analysis can be used to estimate arterial gas content and may be suitable for diagnosis and management of critically ill patients. However, its utility and applicability in the ICU setting remains unexplored. Methods A prospective observational validation study was designed to evaluate this technique in a cohort of mechanically ventilated adult critically ill patients admitted to a polyvalent ICU. Precision and agreement between capillary ga...

  8. Pixel-based analysis of comprehensive two-dimensional gas chromatograms (color plots) of petroleum

    DEFF Research Database (Denmark)

    Furbo, Søren; Hansen, Asger B.; Skov, Thomas

    2014-01-01

    We demonstrate how to process comprehensive two-dimensional gas chromatograms (GC × GC chromatograms) to remove nonsample information (artifacts), including background and retention time shifts. We also demonstrate how this, combined with further reduction of the influence of irrelevant informati......, allows for data analysis without integration or peak deconvolution (pixelbased analysis)....

  9. Exergy analysis of a gas turbine power plant | Oko | Journal of ...

    African Journals Online (AJOL)

    Exergy analysis of a 100MW gas turbine power plant that works on the. Brayton cycle is presented. The average increase in the thermodynamic degradation of the plant over the period of six (6) years at three different levels of load was assessed. The exergy analysis of the plant was done on two sets of data: one from the ...

  10. New methods for modelling and data analysis in gas chromatography: a Bayesian view

    NARCIS (Netherlands)

    Barcaru, A.

    2017-01-01

    Along this thesis were presented several application of Bayesian statistics in gas-chromatographic data analysis. Although complex in understanding for the public used with the frequentist data analysis, Bayesian statistics proved to be useful, robust and objective tool for chromatographic data

  11. Investigate a Gas Well Performance Using Nodal Analysis

    Science.gov (United States)

    Ben Mahmud, Hisham; Abdullah, Aman

    2017-07-01

    Gas condensate well has unique reservoir characteristics and ups and downs in well behaviour affect the production rate significantly. A proper optimization can reduce the operating cost, maximize the hydrocarbon recovery and increase the net present value. Well level optimization can be achieved through optimizing well parameters, such as wellhead, tubing size, and skin factor. All of these factors have been investigated using a real field of Thrace Basin and PROSPER simulation program. The history matching data are validated to identify the future performance prediction for the same reservoir deliverability following the period changes. Therefore, predicted results are compared and validated with measured field data to provide the best production practices. Moreover, the results show that the skin factor has a large influence on the production rate by 45% reduction. The reduction in the reservoir pressure declines the production rate dramatically resulted in 70% decline. While manipulating the wellhead pressure shows minor decline compare to tubing size that does not show any significant change to production rate.

  12. Multi-scale structural analysis of gas diffusion layers

    Science.gov (United States)

    Göbel, Martin; Godehardt, Michael; Schladitz, Katja

    2017-07-01

    The macroscopic properties of materials are strongly determined by their micro structure. Here, transport properties of gas diffusion layers (GDL) for fuel cells are considered. In order to simulate flow and thermal properties, detailed micro structural information is essential. 3D images obtained by high-resolution computed tomography using synchrotron radiation and scanning electron microscopy (SEM) combined with focused ion beam (FIB) serial slicing were used. A recent method for reconstruction of porous structures from FIB-SEM images and sophisticated morphological image transformations were applied to segment the solid structural components. The essential algorithmic steps for segmenting the different components in the tomographic data-sets are described and discussed. In this paper, two types of GDL, based on a non-woven substrate layer and a paper substrate layer were considered, respectively. More than three components are separated within the synchrotron radiation computed tomography data. That is, fiber system, polytetrafluoroethylene (PTFE) binder/impregnation, micro porous layer (MPL), inclusions within the latter, and pore space are segmented. The usage of the thus derived 3D structure data in different simulation applications can be demonstrated. Simulations of macroscopic properties such as thermal conductivity, depending on the flooding state of the GDL are possible.

  13. Methodology for Structural Integrity Analysis of Gas Turbine Blades

    Directory of Open Access Journals (Sweden)

    Tiago de Oliveira Vale

    2012-03-01

    Full Text Available One of the major sources of stress arising in turbomachinery blades are the centrifugal loads acting at any section of the airfoil. Accounting for this phenomenon stress evaluation of the blade attachment region in the disc has to be performed in order to avoid blade failure. Turbomachinery blades are generally twisted, and the cross section area varies from the root of the blade to the tip. The blade root shape at the attachment region is of great concern. Stress concentrations are predictable at this contact region. In this paper, a finite element model has been created for the purpose of assessing stress at the joint region connecting the blade to the disc slot. Particular attention was paid to the geometric modeling of the "fir-tree" fixing, which is now used in the majority of gas turbine engines. This study has been performed using the commercial software ANSYS 13.0. The disc and blade assembly are forced to move with a certain rotational velocity. Contact connections are predicted on the common faces of the blade and on the disc at the root. Solutions can be obtained to allow the evaluation of stresses. Results can be compared with the mechanical properties of the adopted material.

  14. AVO Analysis of a Shallow Gas Accumulation in the Marmara Sea

    Science.gov (United States)

    Er, M.; Dondurur, D.; Çifçi, G.

    2012-04-01

    In recent years, Amplitude versus Offset-AVO analysis is widely used in determination and classification of gas anomalies from wide-offset seismic data. Bright spots which are among the significant factors in determining the hydrocarbon accumulations, can also be determined sucessfully using AVO analysis. A bright spot anomaly were identified on the multi-channel seismic data collected by R/V K. Piri Reis research vessel in the Marmara Sea in 2008. On prestack seismic data, the associated AVO anomalies are clearly identified on the supergathers. Near- and far-offset stack sections are plotted to show the amplitudes changes at different offsets and the bright amplitudes were observed on the far-offset stack. AVO analysis was applied to the observed bright spot anomaly following the standart data processing steps. The analysis includes the preparation of Intercept, Gradient and Fluid Factor sections of AVO attribues. Top and base boundaries of gas bearing sediment were shown by intercept - gradient crossplot method. 1D modelling was also performed to show AVO classes and models were compared with the analysis results. It is interpreted that the bright spot anomaly arises from a shallow gas accumulation. In addition, the gas saturation from P-wave velocity was also estimated by the analysis. AVO analysis indicated Class 3 and Class 4 AVO anomalies observed on the bright spot anomaly.

  15. Sustainability Assessment of the Natural Gas Industry in China Using Principal Component Analysis

    Directory of Open Access Journals (Sweden)

    Xiucheng Dong

    2015-05-01

    Full Text Available Under pressure toward carbon emission reduction and air protection, China has accelerated energy restructuring by greatly improving the supply and consumption of natural gas in recent years. However, several issues with the sustainable development of the natural gas industry in China still need in-depth discussion. Therefore, based on the fundamental ideas of sustainable development, industrial development theories and features of the natural gas industry, a sustainable development theory is proposed in this thesis. The theory consists of five parts: resource, market, enterprise, technology and policy. The five parts, which unite for mutual connection and promotion, push the gas industry’s development forward together. Furthermore, based on the theoretical structure, the Natural Gas Industry Sustainability Index in China is established and evaluated via the Principal Component Analysis (PCA method. Finally, a conclusion is reached: that the sustainability of the natural gas industry in China kept rising from 2008 to 2013, mainly benefiting from increasing supply and demand, the enhancement of enterprise profits, technological innovation, policy support and the optimization and reformation of the gas market.

  16. Visibility graph network analysis of natural gas price: The case of North American market

    Science.gov (United States)

    Sun, Mei; Wang, Yaqi; Gao, Cuixia

    2016-11-01

    Fluctuations in prices of natural gas significantly affect global economy. Therefore, the research on the characteristics of natural gas price fluctuations, turning points and its influencing cycle on the subsequent price series is of great significance. Global natural gas trade concentrates on three regional markets: the North American market, the European market and the Asia-Pacific market, with North America having the most developed natural gas financial market. In addition, perfect legal supervision and coordinated regulations make the North American market more open and more competitive. This paper focuses on the North American natural gas market specifically. The Henry Hub natural gas spot price time series is converted to a visibility graph network which provides a new direction for macro analysis of time series, and several indicators are investigated: degree and degree distribution, the average shortest path length and community structure. The internal mechanisms underlying price fluctuations are explored through the indicators. The results show that the natural gas prices visibility graph network (NGP-VGN) is of small-world and scale-free properties simultaneously. After random rearrangement of original price time series, the degree distribution of network becomes exponential distribution, different from the original ones. This means that, the original price time series is of long-range negative correlation fractal characteristic. In addition, nodes with large degree correspond to significant geopolitical or economic events. Communities correspond to time cycles in visibility graph network. The cycles of time series and the impact scope of hubs can be found by community structure partition.

  17. Economic evaluation and market analysis for natural gas utilization. Topical report

    Energy Technology Data Exchange (ETDEWEB)

    Hackworth, J.H.; Koch, R.W.; Rezaiyan, A.J.

    1995-04-01

    During the past decade, the U.S. has experienced a surplus gas supply. Future prospects are brightening because of increased estimates of the potential size of undiscovered gas reserves. At the same time, U.S. oil reserves and production have steadily declined, while oil imports have steadily increased. Reducing volume growth of crude oil imports was a key objective of the Energy Policy Act of 1992. Natural gas could be an important alternative energy source to liquid products derived from crude oil to help meet market demand. The purpose of this study was to (1) analyze three energy markets to determine whether greater use could be made of natural gas or its derivatives and (2) determine whether those products could be provided on an economically competitive basis. The following three markets were targeted for possible increases in gas use: transportation fuels, power generation, and chemical feedstock. Gas-derived products that could potentially compete in these three markets were identified, and the economics of the processes for producing those products were evaluated. The processes considered covered the range from commercial to those in early stages of process development. The analysis also evaluated the use of both high-quality natural gas and lower-quality gases containing CO{sub 2} and N{sub 2} levels above normal pipeline quality standards.

  18. High-order evolving surface finite element method for parabolic problems on evolving surfaces

    OpenAIRE

    Kovács, Balázs

    2016-01-01

    High-order spatial discretisations and full discretisations of parabolic partial differential equations on evolving surfaces are studied. We prove convergence of the high-order evolving surface finite element method, by showing high-order versions of geometric approximation errors and perturbation error estimates and by the careful error analysis of a modified Ritz map. Furthermore, convergence of full discretisations using backward difference formulae and implicit Runge-Kutta methods are als...

  19. Interring Gas Dynamic Analysis of Piston in a Diesel Engine considering the Thermal Effect

    Directory of Open Access Journals (Sweden)

    Wanyou Li

    2015-01-01

    Full Text Available Understanding the interaction between ring dynamics and gas transport in ring pack systems is crucial and needs to be imperatively studied. The present work features detailed interring gas dynamics of piston ring pack behavior in internal combustion engines. The model is developed for a ring pack with four rings. The dynamics of ring pack are simulated. Due to the fact that small changes in geometry of the grooves and lands would have a significant impact on the interring gas dynamics, the thermal deformation of piston has been considered during the ring pack motion analysis in this study. In order to get the temperature distribution of piston head more quickly and accurately, an efficient method utilizing the concept of inverse heat conduction is presented. Moreover, a sensitive analysis based on the analysis of partial regression coefficients is presented to investigate the effect of groove parameters on blowby.

  20. (N+1)-dimensional Lorentzian evolving wormholes supported by polytropic matter

    Energy Technology Data Exchange (ETDEWEB)

    Cataldo, Mauricio [Universidad del Bio-Bio, Departamento de Fisica, Facultad de Ciencias, Concepcion (Chile); Arostica, Fernanda; Bahamonde, Sebastian [Universidad de Concepcion, Departamento de Fisica, Concepcion (Chile)

    2013-08-15

    In this paper we study (N+1)-dimensional evolving wormholes supported by energy satisfying a polytropic equation of state. The considered evolving wormhole models are described by a constant redshift function and generalizes the standard flat Friedmann-Robertson-Walker spacetime. The polytropic equation of state allows us to consider in (3+1)-dimensions generalizations of the phantom energy and the generalized Chaplygin gas sources. (orig.)

  1. APPLYING OF GAS ANALYSIS IN DIAGNOSIS OF BRONCHOPULMONARY DISEASES

    Directory of Open Access Journals (Sweden)

    Ye. B. Bukreyeva

    2014-01-01

    Full Text Available Bronchopulmonary system diseases are on the first place among the causes of people's death. Most of methods for lung diseases diagnosis are invasive or not suitable for children and patients with severe disease. One of the promising methods of clinical diagnosis and disease activity monitoring of bronchopulmonary system is analyzing of human breath. Directly exhaled breath or exhaled breath condensate are using for human breaths analyzing. Analysis of human breath can apply for diagnostic, long monitoring and evaluation of efficacy of the treatment bronchopulmonary diseases. Differential diagnostic between chronic obstructive lung disease (COPD and bronchial asthma is complicated because they have differences in pathogenesis. Analysis of human breath allows to explore features of COPD and bronchial asthma and to improve differential diagnostic of these diseases. Human breaths analyzing can apply for diagnostic dangerous diseases, such as tuberculosis, lung cancer. The analysis of breath air by spectroscopy methods is new noninvasive way for diagnosis of bronchopulmonary diseases.

  2. Stress analysis of parallel oil and gas steel pipelines in inclined tunnels.

    Science.gov (United States)

    Wu, Xiaonan; Lu, Hongfang; Wu, Shijuan

    2015-01-01

    Geological conditions along long distance pipelines are complex. In consideration of differences in elevation and terrain obstacles, long distance pipelines are commonly laid through tunnels. Oil and gas pipelines are often laid side by side to reduce construction costs and minimize geological impact. The layout and construction of parallel oil and gas pipelines are more complex than those of single pipelines. In order to reduce safety hazards, it is necessary to carry out stress analysis of the oil and gas pipelines that run through tunnels. In this study, a stress analysis model of pipelines running through a tunnel was developed. On the basis of the finite element method, CAESAR II software was used to analyze the stress and displacement of a section of parallel oil and gas pipelines that run through tunnels and stress and displacement distribution laws were drawn from the analyses. A study of the factors influencing stress recommended that: (1) The buttress interval of the parallel oil and gas pipelines in a tunnel should be 12 m; (2) The angle of inclined pipelines should be no greater than 25°; (3) The stress of oil pipelines enhances more obviously than that of gas pipelines under earthquake action; (4) The average stress can be reduced by adopting "ladder" laying; and (5) Guide bend can be set at the tunnel entrance and exit in order to reduce the stress.

  3. Spectral Analysis of Moderately Charged Rare-Gas Atoms

    Directory of Open Access Journals (Sweden)

    Jorge Reyna Almandos

    2017-03-01

    Full Text Available This article presents a review concerning the spectral analysis of several ions of neon, argon, krypton and xenon, with impact on laser studies and astrophysics that were mainly carried out in our collaborative groups between Argentina and Brazil during many years. The spectra were recorded from the vacuum ultraviolet to infrared regions using pulsed discharges. Semi-empirical approaches with relativistic Hartree–Fock and Dirac-Fock calculations were also included in these investigations. The spectral analysis produced new classified lines and energy levels. Lifetimes and oscillator strengths were also calculated.

  4. Analysis of gas turbine cogeneration plants in Italy; Indagine sulla funzionalita` degli impianti di cogenerazione conturbina a gas operanti in Italia

    Energy Technology Data Exchange (ETDEWEB)

    Romani, Rino; Vignati, Sigfrido [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dipt. Energia

    1997-10-01

    The purpose of this study is to improve, by random analysis, the current knowledge about functional and running data of gas turbine cogeneration plants in Italy. The analysis consider simple and combined cycle gas turbines plant with electric power less 30.000 k W per unit and involves a sample of 44 units according to a randomized model consisting of 112 gas turbines. The collected data show different plant selection criteria, energy performances, reliability and availability values as well as maintenance costs. These data support some general suggestions and recommendations for a better selection and utilization of these plants.

  5. Modeling and parametric analysis of hollow fiber membrane system for carbon capture from multicomponent flue gas

    KAUST Repository

    Khalilpour, Rajab

    2011-08-12

    The modeling and optimal design/operation of gas membranes for postcombustion carbon capture (PCC) is presented. A systematic methodology is presented for analysis of membrane systems considering multicomponent flue gas with CO 2 as target component. Simplifying assumptions is avoided by namely multicomponent flue gas represented by CO 2/N 2 binary mixture or considering the co/countercurrent flow pattern of hollow-fiber membrane system as mixed flow. Optimal regions of flue gas pressures and membrane area were found within which a technoeconomical process system design could be carried out. High selectivity was found to not necessarily have notable impact on PCC membrane performance, rather, a medium selectivity combined with medium or high permeance could be more advantageous. © 2011 American Institute of Chemical Engineers (AIChE).

  6. Natural selection promotes antigenic evolvability

    NARCIS (Netherlands)

    Graves, C.J.; Ros, V.I.D.; Stevenson, B.; Sniegowski, P.D.; Brisson, D.

    2013-01-01

    The hypothesis that evolvability - the capacity to evolve by natural selection - is itself the object of natural selection is highly intriguing but remains controversial due in large part to a paucity of direct experimental evidence. The antigenic variation mechanisms of microbial pathogens provide

  7. Ion beam analysis of gas turbine blades: evaluation of refurbishment ...

    Indian Academy of Sciences (India)

    In the cross-sections of refurbished and used samples, distinct regions were identified corresponding to the base superalloy, original protection layer and applied coating for refurbishment. The elemental composition of each of these regions was measured by Micro-PIXE analysis. Inhomogeneous and high content of Si as ...

  8. Gas dynamic analysis of the performance of diffuser augmented ...

    Indian Academy of Sciences (India)

    ASME 3: 120±125. Mayer D W, Kneeling W 1992 Evaluation of two-flow analysis for subsonic diffuser design. 30th. Aerospace Society Meeting, Dena, NV, AIAA Paper 92-0273. Mohamed F A, Badawy M T S 1997 The optimal characteristics of a horizontal axis wind turbine electric generator system. Florence World Energy ...

  9. Gas dynamic analysis of the performance of diffuser augmented ...

    Indian Academy of Sciences (India)

    A diffuser augmented wind turbine (DAWT) is considered an important application of the advanced concepts to improve the attractiveness of wind energy. The present paper aims to find a theoretical demonstration of DAWT by using theoretical analysis, mathematical models, assumptions, estimations and maximization of ...

  10. The application of FAIMS gas analysis in medical diagnostics

    NARCIS (Netherlands)

    Covington, J. A.; van der Schee, M. P.; Edge, A. S. L.; Boyle, B.; Savage, R. S.; Arasaradnam, R. P.

    2015-01-01

    There is an ever increasing need to develop new tools to aid in the diagnosis and monitoring of human diseases. Such tools will ultimately reduce the cost of healthcare by identifying disease states more quickly and cheaply than current practices. One method showing promise is the analysis of

  11. Evolving virtual creatures and catapults.

    Science.gov (United States)

    Chaumont, Nicolas; Egli, Richard; Adami, Christoph

    2007-01-01

    We present a system that can evolve the morphology and the controller of virtual walking and block-throwing creatures (catapults) using a genetic algorithm. The system is based on Sims' work, implemented as a flexible platform with an off-the-shelf dynamics engine. Experiments aimed at evolving Sims-type walkers resulted in the emergence of various realistic gaits while using fairly simple objective functions. Due to the flexibility of the system, drastically different morphologies and functions evolved with only minor modifications to the system and objective function. For example, various throwing techniques evolved when selecting for catapults that propel a block as far as possible. Among the strategies and morphologies evolved, we find the drop-kick strategy, as well as the systematic invention of the principle behind the wheel, when allowing mutations to the projectile.

  12. Operation, Modeling and Analysis of the Reverse Water Gas Shift Process

    Science.gov (United States)

    Whitlow, Jonathan E.

    2001-01-01

    The Reverse Water Gas Shift process is a candidate technology for water and oxygen production on Mars under the In-Situ Propellant Production project. This report focuses on the operation and analysis of the Reverse Water Gas Shift (RWGS) process, which has been constructed at Kennedy Space Center. A summary of results from the initial operation of the RWGS, process along with an analysis of these results is included in this report. In addition an evaluation of a material balance model developed from the work performed previously under the summer program is included along with recommendations for further experimental work.

  13. Analysis of Discharged Gas from Incinerator using Simulated Organic Solution

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seungil; Kim, Hyunki; Heo, Jun; Kang, Dukwon [HaJI Co., Ltd., Radiation Eng. Center, Siheung (Korea, Republic of); Kim, Yunbok; Kwon, Youngbock [KORAD, Daejeon (Korea, Republic of)

    2014-05-15

    is controlled from 800 .deg. c to 930 .deg. C using temperature controller. The concentration of gaseous pollutants released by incinerating simulated organic waste is satisfied with Clean Air Conservation Act, Notification of Nuclear Safety Commission, Persistent Organic Pollutants Control Act and related statute. The incinerator used in this experiment is not object of regulation but the concentration of dioxin released from incinerator, 0.007ng-TEQ/Sm{sup 3}, could be ignored because it is just 7%, in comparison with the limit of exhaust standard, 0.1ng-TEQ/Sm{sup 3}. This is due to the rapid cooling of exhaust gas using heat-exchanger.

  14. High resolution gas chromatography analysis of rice bran oil

    Science.gov (United States)

    Yu, Fengxiang; Lin, Qinlu; Chen, Xu; Wei, Xiaojun

    To assess the nutritional value and safety quality of rice bran oil (RBO) ,fatty acids of RBO from 15 species rice come from Hunan Province were analyzed by high resolution gas chromatography (HRGC). Crude RBOs were extracted by hexane 3-times using a solvent-to-rice bran ratio of 3:1 (w/w) at 40°C and composition of RBOs was analyzed by HRGC. The result showed that main fatty acids of 15 kinds of RBO include myristic acid (C14:0), palmitic acid (C16:0), palmitoleic acid (C16:1), stearic acid (C18:0), oleic acid (C18:1), linoleic acid (C18:2), linolenic acid (C18:3), arachidic acid (C20:0), arachidonic acid (C20:1). It is strange that arachidonic acid (C20:1) is not listed in Chinese standard of RBO (GB11192-2003), and it exists in our samples of RBO. The average value of linolenic acid in RBOs is 1.6304% (range from 1.2425% to 2.131%), and it showed higher level comparing with Chinese standard that linolenic acid is less than 1.0%. The average value of USFA and SFA are 76.81% (range 75.96% to 82.06% ) and 20.15% (range 13.72% to 23.06%) respectively, and USFA content is close to olive oil (83.75%), peanut oil (81.75%) and soybean oil (85.86%). USFA in Jingyou 13 RBO is the highest content. The ratio of USFA to SFA content is 4:1 (range from 3.32 to 5.98:1). The ratio of SFA: MUFA: PUFA of 15 RBOs is 1: 2.2: 1.8, and ω6/ω3 ratio is 21.69 (range from16.54 to 27.28) and it is close to the 26:1 which is reported to be helpful to increase SOD activity. The oleic acid /linoleic acid ratio of 15 RBOs is 1.23:1 (rang from 1.04:1 to 1.42:1). Our data analyzed composition of RBOs from 15 species rice of China and will provide new evidence to revise RBO standard. It also helps us to assess nutritional value of RBOs and identify different RBOs from various species rice and places of origin.

  15. Evolved atmospheric entry corridor with safety factor

    Science.gov (United States)

    Liang, Zixuan; Ren, Zhang; Li, Qingdong

    2018-02-01

    Atmospheric entry corridors are established in previous research based on the equilibrium glide condition which assumes the flight-path angle to be zero. To get a better understanding of the highly constrained entry flight, an evolved entry corridor that considers the exact flight-path angle is developed in this study. Firstly, the conventional corridor in the altitude vs. velocity plane is extended into a three-dimensional one in the space of altitude, velocity, and flight-path angle. The three-dimensional corridor is generated by a series of constraint boxes. Then, based on a simple mapping method, an evolved two-dimensional entry corridor with safety factor is obtained. The safety factor is defined to describe the flexibility of the flight-path angle for a state within the corridor. Finally, the evolved entry corridor is simulated for the Space Shuttle and the Common Aero Vehicle (CAV) to demonstrate the effectiveness of the corridor generation approach. Compared with the conventional corridor, the evolved corridor is much wider and provides additional information. Therefore, the evolved corridor would benefit more to the entry trajectory design and analysis.

  16. Gene expression analysis of parthenogenetic embryonic development of the pea aphid, Acyrthosiphon pisum, suggests that aphid parthenogenesis evolved from meiotic oogenesis.

    Science.gov (United States)

    Srinivasan, Dayalan G; Abdelhady, Ahmed; Stern, David L

    2014-01-01

    Aphids exhibit a form of phenotypic plasticity, called polyphenism, in which genetically identical females reproduce sexually during one part of the life cycle and asexually (via parthenogenesis) during the remainder of the life cycle. The molecular basis for aphid parthenogenesis is unknown. Cytological observations of aphid parthenogenesis suggest that asexual oogenesis evolved either through a modification of meiosis or from a mitotic process. As a test of these alternatives, we assessed the expression levels and expression patterns of canonical meiotic recombination and germline genes in the sexual and asexual ovaries of the pea aphid, Acyrthosiphon pisum. We observed expression of all meiosis genes in similar patterns in asexual and sexual ovaries, with the exception that some genes encoding Argonaute-family members were not expressed in sexual ovaries. In addition, we observed that asexual aphid tissues accumulated unspliced transcripts of Spo11, whereas sexual aphid tissues accumulated primarily spliced transcripts. In situ hybridization revealed Spo11 transcript in sexual germ cells and undetectable levels of Spo11 transcript in asexual germ cells. We also found that an obligately asexual strain of pea aphid produced little spliced Spo11 transcript. Together, these results suggest that parthenogenetic oogenesis evolved from a meiosis-like, and not a mitosis-like, process and that the aphid reproductive polyphenism may involve a modification of Spo11 gene activity.

  17. Evolving nucleotide binding surfaces

    Science.gov (United States)

    Kieber-Emmons, T.; Rein, R.

    1981-01-01

    An analysis is presented of the stability and nature of binding of a nucleotide to several known dehydrogenases. The employed approach includes calculation of hydrophobic stabilization of the binding motif and its intermolecular interaction with the ligand. The evolutionary changes of the binding motif are studied by calculating the Euclidean deviation of the respective dehydrogenases. Attention is given to the possible structural elements involved in the origin of nucleotide recognition by non-coded primordial polypeptides.

  18. Analysis and clustering of natural gas consumption data for thermal energy use forecasting

    Science.gov (United States)

    Franco, Alessandro; Fantozzi, Fabio

    2015-11-01

    In this paper, after a brief analysis of the connections between the uses of natural gas and thermal energy use, the natural gas consumption data related to Italian market are analyzed and opportunely clustered in order to compute the typical consumption profile in different days of the week in different seasons and for the different class of users: residential, tertiary and industrial. The analysis of the data shows that natural gas consumption profile is mainly related to seasonality pattern and to the weather conditions (outside temperature, humidity and wind chiller). There is also an important daily pattern related to industrial and civil sector that, at a lower degree than the previous one, does affect the consumption profile and have to be taken into account for defining an effective short and mid term thermal energy forecasting method. A possible mathematical structure of the natural gas consumption profile is provided. Due to the strong link between thermal energy use and natural gas consumption, this analysis could be considered the first step for the development of a model for thermal energy forecasting.

  19. Potentiometric determination of total nitrogen in soils by flow injection analysis with a gas-diffusion unit

    OpenAIRE

    Ferreira, Alexandra M. R.; José L. F. C. Lima; Rangel,António O. S. S.

    1996-01-01

    A flow injection analysis (FIA) system incorporating a gas-diffusion unit and a potentiometric detector was developed for the determination of total nitrogen in soil digests. The solutions obtained from the Kjeldahl digestion of the soil samples were injected in the FIA system where ammonium was converted into ammonia. This gas diffused through a gas-permeable membrane to a buffer acceptor stream, allowing the separation of the gas from the rest of the sample. Once in contact with the buffer ...

  20. Design of continuous circulation sub for gas drilling and the mechanical analysis on the sub body

    Directory of Open Access Journals (Sweden)

    Ding Feng

    2016-01-01

    Full Text Available Gas drilling, as an important part of underbalanced drilling, can increase drilling speed. But in the process of conventional gas drilling, it tends to cause cutting settlement, borehole collapse, sticking and other safety hazards because gas circulation has to be interrupted. Therefore, this paper presents a continuous circulation sub which can be installed and removed easily. With this sub, gas circulation will not be interrupted when drilling tools are connected and removed. This sub is composed of body, main valve, bypass valve and side entry sub. The structure design of its key components (i.e. main and bypass valves were fulfilled. Based on statics analysis on the sub body, its force situations under extension, torsion and internal pressure were simulated by using the ANSYS finite element analysis software. It is shown that its stress distribution trend is consistent with its elastic–plastic mechanics analysis results. Stress concentrates around the two round holes of the sub body, and the maximum deformation amount is still at the stage of elastic deformation. The analysis results are in line with the elastic–plastic mechanics analysis results, and the requirement of body strength is satisfied. This paper provides a new program to guarantee the drilling safety of extended-reach wells, underbalanced wells and narrow-density window wells.

  1. Evolving Procurement Organizations

    DEFF Research Database (Denmark)

    Bals, Lydia; Laine, Jari; Mugurusi, Godfrey

    putting the structural elements in focus is derived from the analysis of two case companies, which extends the existing literature and opens new avenues for future research. The findings highlight the importance of taking a contingency perspective on procurement organization, understanding the internal...... in future studies in the fields of hybrid procurement organizations, global sourcing organizations as well as international procurement offices (IPOs). From a practical standpoint, an assessment of external and internal contingencies and their relation to specific structural dimensions that can be chosen...... provides the opportunity to consciously match an organization to its operating environment and internal demands....

  2. Fatigue life analysis of cracked gas receiver of emergency cut-off system in gas gathering station

    Science.gov (United States)

    Hu, Junzhi; Zhou, Jiyong; Li, Siyuan

    2017-06-01

    Small-scale air compressor and gas receiver are used as the driving gas of the emergency cut-off system in gas gathering station. Operation of block valve is ensured by starting and stopping compressor automatically. The frequent start-stop of compressor and the pressure fluctuation pose a threat to the service life of gas receiver, and then affect normal operation of the emergency cut-off system and security of gas gathering station. In this paper, the fatigue life of a pressure vessel with axial semi-elliptical surface crack in the inner wall is analyzed under the varying pressure by means of the theory of fracture mechanics. The influences of the amplitude of pressure fluctuation and the initial crack size on the residual life of gas receiver are discussed. It provides a basis for setting the working parameters of gas receiver of emergency cut-off system and determining the maintenance cycle.

  3. Application of gas chromatography to analysis of spirit-based alcoholic beverages.

    Science.gov (United States)

    Wiśniewska, Paulina; Śliwińska, Magdalena; Dymerski, Tomasz; Wardencki, Waldemar; Namieśnik, Jacek

    2015-01-01

    Spirit-based beverages are alcoholic drinks; their production processes are dependent on the type and origin of raw materials. The composition of this complex matrix is difficult to analyze, and scientists commonly choose gas chromatography techniques for this reason. With a wide selection of extraction methods and detectors it is possible to provide qualitative and quantitative analysis for many chemical compounds with various functional groups. This article describes different types of gas chromatography techniques and their most commonly used associated extraction techniques (e.g., LLE, SPME, SPE, SFE, and SBME) and detectors (MS, TOFMS, FID, ECD, NPD, AED, O or EPD). Additionally, brief characteristics of internationally popular spirit-based beverages and application of gas chromatography to the analysis of selected alcoholic drinks are presented.

  4. Sensitivity analysis of a light gas oil deep hydrodesulfurization process via catalytic distillation

    Energy Technology Data Exchange (ETDEWEB)

    Rosales-Quintero, A.; Vargas-Villamil, F.D. [Prog. de Matematicas Aplicadas y Computacion, Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152, Mexico, D.F. 07330 (Mexico); Arce-Medina, E. [Instituto Politecnico Nacional, ESIQIE, Ed. 8 Col. Lindavista, Mexico, D.F. 07738 (Mexico)

    2008-01-30

    In this work, a sensitivity analysis of a light gas oil deep hydrodesulfurization catalytic distillation column is presented. The aim is to evaluate the effects of various parameters and operating conditions on the organic sulfur compound elimination by using a realistic light gas oil fraction. The hydrocarbons are modeled using pseudocompounds, while the organic sulfur compounds are modeled using model compounds, i.e., dibenzothiophene (DBT) and 4,6-dimethyl dibenzothiophene (4,6-DMDBT). These are among the most refractive sulfur compounds present in the oil fractions. A sensitivity analysis is discussed for the reflux ratio, bottom flow rate, condenser temperature, hydrogen and gas oil feed stages, catalyst loading, the reactive, stripping, and rectifying stages, feed disturbances, and multiple feeds. The results give insight into the qualitative effect of some of the operating variables and disturbances on organic sulfur elimination. In addition, they show that special attention must be given to the bottom flow rate and LGO feed rate control. (author)

  5. Spectral analysis of semiconductor-based surface plasmon resonance sensors for infrared-gas sensing

    Science.gov (United States)

    Ghosh, S.; Ray, M.

    2015-06-01

    In present analysis a semiconductor-based surface plasmon resonance structure using Gr-IV materials (Silicon and Germanium) has been analyzed in spectral interrogation mode which can be used for efficient environmental monitoring and Infrared (IR) gas-sensing purposes. The Silicon-Germanium (Si-Ge) combination structure is able to confine an extremely high evanescent field in the sensing region due to their extraordinary high refractive indices (RI). Higher concentration of optical field in the sensing area provides enhanced spectral sensitivity for infrared gas-sensing. Better detection accuracy and adequate dynamic range are other additional advantages offered by such semiconductor-based surface plasmon resonance (SPR) configurations. Analysis of the SPR structure has also been carried out in terms of detection accuracy, figure of merit and Q-factor of the gas-sensor.

  6. Analysis of micro vibration in gas film of aerostatic guide way based on molecule collision theory

    Directory of Open Access Journals (Sweden)

    Yang Shao Hua

    2016-01-01

    Full Text Available Micro vibration of the aerostatic guide way has a significant impact on its dynamic characteristics and stability, which limits the development of pneumatic component. High pressure gas molecules have been collided with the supporting surface and the internal surface of the throttle during the flow process. Variable impulse of the surfaces aside for the gas film are affected by the changes of impulse which formed irregular impact force in horizontal and vertical direction. Micro-vibration takes place based on the natural frequency of the system and its frequency doubling. In this paper, the vibration model was established to describe the dynamic characteristics of the gas film, and the formation mechanism of micro vibration in the film is defined. Through the simulation analysis and experimental comparison, formation mechanism of the micro vibration in the gas film is confirmed. It was proposed that the micro vibration of gas film can be produced no matter whether there is a gas chamber or not in the throttle. Under the same conditions, the micro vibration of the guide way with air chamber is greater than that without any chamber. The frequency points of the vibration peaks are almost the same, as well as the vibration pattern in the frequency domain.

  7. Off-Design Behavior Analysis and Operating Curve Design of Marine Intercooled Gas Turbine

    Directory of Open Access Journals (Sweden)

    Nian-kun Ji

    2017-01-01

    Full Text Available The intercooled gas turbine obtained by adopting an indirect heat exchanger into an existing gas turbine is one of the candidates for developing high-power marine power units. To simplify such a strong coupled nonlinear system reasonably, the feasibility and availability of qualifying equivalent effectiveness as the only parameter to evaluate the intercooler behavior are investigated. Regarding equivalent effectiveness as an additional degree of freedom, the steady state model of a marine intercooled gas turbine is developed and its off-design performance is analyzed. With comprehensive considerations given to various phase missions of ships, operational flexibility, mechanical constraints, and thermal constraints, the operating curve of the intercooled gas turbine is optimized based on graphical method in three-dimensional performance space. The resulting operating curve revealed that the control strategy at the steady state conditions for the intercooled gas turbine should be variable cycle control. The necessity of integration optimization design for gas turbine and intercooler is indicated and the modeling and analysis method developed in this paper should be beneficial to it.

  8. Offshore Antarctic Peninsula Gas Hydrate Reservoir Characterization by Geophysical Data Analysis

    Directory of Open Access Journals (Sweden)

    Michela Giustiniani

    2010-12-01

    Full Text Available A gas hydrate reservoir, identified by the presence of the bottom simulating reflector, is located offshore of the Antarctic Peninsula. The analysis of geophysical dataset acquired during three geophysical cruises allowed us to characterize this reservoir. 2D velocity fields were obtained by using the output of the pre-stack depth migration iteratively. Gas hydrate amount was estimated by seismic velocity, using the modified Biot-Geerstma-Smit theory. The total volume of gas hydrate estimated, in an area of about 600 km2, is in a range of 16 × 109–20 × 109 m3. Assuming that 1 m3 of gas hydrate corresponds to 140 m3 of free gas in standard conditions, the reservoir could contain a total volume that ranges from 1.68 to 2.8 × 1012 m3 of free gas. The interpretation of the pre-stack depth migrated sections and the high resolution morpho-bathymetry image allowed us to define a structural model of the area. Two main fault systems, characterized by left transtensive and compressive movement, are recognized, which interact with a minor transtensive fault system. The regional geothermal gradient (about 37.5 °C/km, increasing close to a mud volcano likely due to fluid-upwelling, was estimated through the depth of the bottom simulating reflector by seismic data.

  9. An analysis of the coal-seam gas resource of the Piceance Basin, Colorado

    Energy Technology Data Exchange (ETDEWEB)

    McFall, K.S.; Wicks, D.E.; Kelso, B.S.; Brandenburg, C.F.

    1988-06-01

    A detailed geologic analysis of the Piceance basin in northwestern Colorado shows that nearly 84 Tcf (2.4 x 10/sup 12/ m/sup 3/) of coal-seam gas is in place in three target coal groups. The Cameo coal group contains the most coalbed methane with 65 Tcf (1.8 x 10/sup 12/ m/sup 3/). The more areally limited Coal Ridge and Black Diamond coal groups contain significantly less gas, 10 and 9 Tcf (280 x 10/sup 9/ and 255 x 10/sup 9/ m/sup 3/), respectively. The areas of highest methane concentration are in the east-central portion of the Piceance basin. These areas coincide with thick deposits of high-rank coal at significant depths and their associated higher gas contents. Also, these areas appear to have been structurally (tectonically) altered, leading to enhanced permeability to gas and water. Thus, the east-central basin area appears favorable for coalbed methane production. This study relied on extensive well data to correlate and map the subsurface extent of the Cretaceous coals of the Piceance basin. Newly derived correlations of coal-rank/depth with gas content were used along with estimates of coal volume to determine gas in place.

  10. Humidity independent mass spectrometry for gas phase chemical analysis via ambient proton transfer reaction

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Hongying; Huang, Guangming, E-mail: gmhuang@ustc.edu.cn

    2015-03-31

    Graphical abstract: Direct and humidity independent mass spectrometry analysis of gas phase chemicals could be achieved via ambient proton transfer ionization, ion intensity was found to be stable with humidity ranged from ∼10% to ∼100%. - Highlights: • A humidity independent mass spectrometric method for gas phase samples analysis. • A universal and good sensitivity method. • The method can real time identify plant released raw chemicals. - Abstract: In this work, a humidity independent mass spectrometric method was developed for rapid analysis of gas phase chemicals. This method is based upon ambient proton transfer reaction between gas phase chemicals and charged water droplets, in a reaction chamber with nearly saturate humidity under atmospheric pressure. The humidity independent nature enables direct and rapid analysis of raw gas phase samples, avoiding time- and sample-consuming sample pretreatments in conventional mass spectrometry methods to control sample humidity. Acetone, benzene, toluene, ethylbenzene and meta-xylene were used to evaluate the analytical performance of present method. The limits of detection for benzene, toluene, ethylbenzene and meta-xylene are in the range of ∼0.1 to ∼0.3 ppbV; that of benzene is well below the present European Union permissible exposure limit for benzene vapor (5 μg m{sup −3}, ∼1.44 ppbV), with linear ranges of approximately two orders of magnitude. The majority of the homemade device contains a stainless steel tube as reaction chamber and an ultrasonic humidifier as the source of charged water droplets, which makes this cheap device easy to assemble and facile to operate. In addition, potential application of this method was illustrated by the real time identification of raw gas phase chemicals released from plants at different physiological stages.

  11. An annular gas seal analysis using empirical entrance and exit region friction factors

    Science.gov (United States)

    Elrod, D. A.; Childs, D. W.; Nelson, C. C.

    1990-01-01

    Wall shear stress results from stationary-rotor flow tests of five annular gas seals are used to develop entrance and exit region friction factor models. The friction factor models are used in a bulk-flow seal analysis which predicts leakage and rotor-dynamic coefficients. The predictions of the analysis are compared to experimental results and to the predictions of Nelson's analysis (1985). The comparisons are for smooth-rotor seals with smooth and honeycomb-stators. The present analysis predicts the destabilizing cross-coupled stiffness of a seal better than Nelson's analysis. Both analyses predict direct damping well and direct stiffness poorly.

  12. EVOLVE : International Conference

    CERN Document Server

    Deutz, Andre; Schuetze, Oliver; Bäck, Thomas; Tantar, Emilia; Tantar, Alexandru-Adrian; Moral, Pierre; Legrand, Pierrick; Bouvry, Pascal; Coello, Carlos

    2013-01-01

    Numerical and computational methods are nowadays used in a wide range of contexts in complex systems research, biology, physics, and engineering.  Over the last decades different methodological schools have emerged with emphasis on different aspects of computation, such as nature-inspired algorithms, set oriented numerics, probabilistic systems and Monte Carlo methods. Due to the use of different terminologies and emphasis on different aspects of algorithmic performance there is a strong need for a more integrated view and opportunities for cross-fertilization across particular disciplines. These proceedings feature 20 original publications from distinguished authors in the cross-section of computational sciences, such as machine learning algorithms and probabilistic models, complex networks and fitness landscape analysis, set oriented numerics and cell mapping, evolutionary multiobjective optimization, diversity-oriented search, and the foundations of genetic programming algorithms. By presenting cutting ed...

  13. Evolving Information Ecologies

    DEFF Research Database (Denmark)

    Nicolajsen, Hanne Westh; Bansler, Jørgen P.

    2009-01-01

    This chapter examines how people in organizations appropriate new computer-based media, that is, how they adopt, reconfigure, and integrate advanced communication technologies such as groupware or desktop conferencing systems into their work practice. The chapter presents and analyzes findings from...... an in-depth field study of the adoption and use of a Web-based groupware application—a “virtual workspace”—in a large multinational firm. The analysis focuses, in particular, on the fact that people in modern organizations have plenty of media at their disposal and often combine old and new media...... to accomplish their work tasks. Furthermore, it highlights the crucial role of organizational communication genres in shaping how people adopt and use new media. The authors argue that understanding and facilitating the process of appropriation is the key to the successful introduction of new media...

  14. Analysis of fission gas release in LWR fuel using the BISON code

    Energy Technology Data Exchange (ETDEWEB)

    G. Pastore; J.D. Hales; S.R. Novascone; D.M. Perez; B.W. Spencer; R.L. Williamson

    2013-09-01

    Recent advances in the development of the finite-element based, multidimensional fuel performance code BISON of Idaho National Laboratory are presented. Specifically, the development, implementation and testing of a new model for the analysis of fission gas behavior in LWR-UO2 fuel during irradiation are summarized. While retaining a physics-based description of the relevant mechanisms, the model is characterized by a level of complexity suitable for application to engineering-scale nuclear fuel analysis and consistent with the uncertainties pertaining to some parameters. The treatment includes the fundamental features of fission gas behavior, among which are gas diffusion and precipitation in fuel grains, growth and coalescence of gas bubbles at grain faces, grain growth and grain boundary sweeping effects, thermal, athermal, and transient gas release. The BISON code incorporating the new model is applied to the simulation of irradiation experiments from the OECD/NEA International Fuel Performance Experiments database, also included in the IAEA coordinated research projects FUMEX-II and FUMEX-III. The comparison of the results with the available experimental data at moderate burn-up is presented, pointing out an encouraging predictive accuracy, without any fitting applied to the model parameters.

  15. Parametric Analysis of a Two-Shaft Aeroderivate Gas Turbine of 11.86 MW

    Directory of Open Access Journals (Sweden)

    R. Lugo-Leyte

    2015-08-01

    Full Text Available The aeroderivate gas turbines are widely used for power generation in the oil and gas industry. In offshore marine platforms, the aeroderivative gas turbines provide the energy required to drive mechanically compressors, pumps and electric generators. Therefore, the study of the performance of aeroderivate gas turbines based on a parametric analysis is relevant to carry out a diagnostic of the engine, which can lead to operational as well as predictive and/or corrective maintenance actions. This work presents a methodology based on the exergetic analysis to estimate the irrevesibilities and exergetic efficiencies of the main components of a two-shaft aeroderivate gas turbine. The studied engine is the Solar Turbine Mars 100, which is rated to provide 11.86 MW. In this engine, the air is compressed in an axial compressor achieving a pressure ratio of 17.7 relative to ambient conditions and a high pressure turbine inlet temperature of 1220 °C. Even if the thermal efficiency associated to the pressure ratio of 17.7 is 1% lower than the maximum thermal efficiency, the irreversibilities related to this pressure ratio decrease approximately 1 GW with respect to irreversibilities of the optimal pressure ratio for the thermal efficiency. In addition, this paper contributes to develop a mathematical model to estimate the high turbine inlet temperature as well as the pressure ratio of the low and high pressure turbines.

  16. An Analysis of Cold Gas Flow-Field for UHV Class Interrupters

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ki Dong; Park, Kyong Yop [Korea Electrotechnology Research Institute (Korea); Song, Won Pyo [Hyosung Heavy Industrial (Korea)

    2000-06-01

    This paper presents a method of cold gas flow-field analysis within puffer type GCB(Gas Circuit Breaker). Using this method, the entire interruption process including opening operation of GCB can be simulated successfully. In particular, the distortion problem of the grid due to the movement of moving parts can be dealt with by the fixed grid technique. The gas parameters such as temperature, pressure, density, velocity through the entire interruption process can be calculated and visualized. It was confirmed that the time variation of pressure which was calculated from the application of the method to a model GCB agreed with the experimental one. Therefore it is possible to evaluate the small current interruption capability analytically and to design the interrupter which has excellent interruption capability using the proposed method. It is expected that the proposed method can reduce the time and cost for development of GCB very much. It also will be possible to develop the hot-gas flow-field analysis program by combining the cold-gas flow field program with the arc model and to evaluate the large current interruption capability. (author). 9 refs., 11 figs., 1 tab.

  17. Comprehensive two-dimensional gas chromatography for the analysis of organohalogenated micro-contaminants

    NARCIS (Netherlands)

    Korytar, P.; Haglund, P.; Boer, de J.; Brinkman, U.A.Th.

    2006-01-01

    We explain the principles of comprehensive two-dimensional gas chromatography (GC × GC), and discuss key instrumental aspects - with emphasis on column combinations and mass spectrometric detection. As the main item of interest, we review the potential of GC × GC for the analysis of

  18. A multivariate statistical analysis approach to analyze gas chromatography-olfactometry data of tangerine hybrids

    Science.gov (United States)

    Gas chromatography (GC) hyphenated with olfactometry (O) when a human subject smells the effluent of the GC is a useful technique to identify aroma activity of volatile compounds in a food. Many techniques have been developed, based on olfactory thresholds (CHARM analysis, AEDA), or based on psychop...

  19. Semi-continuous high speed gas analysis of generated vapors of chemical warfare agents

    NARCIS (Netherlands)

    Trap, H.C.; Langenberg, J.P.

    1999-01-01

    A method is presented for the continuous analysis of generated vapors of the nerve agents soman and satin and the blistering agent sulfur mustard. By using a gas sampling valve and a very short (15 cm) column connected to an on-column injector with a 'standard length' column, the system can either

  20. Watching ZZ Ceti evolve

    Science.gov (United States)

    Mukadam, Anjum S.; Kim, Agnes; Fraser, Oliver; Winget, D. E.; Kepler, S. O.; Sullivan, D. J.; Reaves, D.; Robinson, E. L.; von Hippel, T.; Mullally, F.; Shipman, H.; Thompson, S. E.; Silvestri, N. M.; Hynes, R. I.

    2009-06-01

    We report preliminary results from our analysis of the stability of periods observed in the pulsating hydrogen atmosphere white dwarf ZZ Ceti (R548) based on observations that span 37 years from 1970 to 2007. We determine the rate of change of period with time to be dP/dt = (0.8±1.9)×10-15 s/s using the O-C method and dP/dt = (4.3±1.2)×10-15 s/s using the direct non-linear least squares fit NLSPDOT for the dominant period 213.13260643 s after correcting for proper motion. We do not claim either of these values as a measurement at this time, but hope to arrive at a conclusive result in the near future with more observations. The reduced uncertainty for both methods shows the improvement we obtained over the previous evolutionary constraint on ZZ Ceti (Mukadam et al. 2003). These dP/dt values are consistent within uncertainties with the measurement of dP/dt = (3.57 ±0.82)×10-15 s/s for the period 215.2 s observed in another pulsating white dwarf G117-B15A (Kepler et al. 2005). Using the 213 s triplet spacing of 4μHz, we compute the rotation period of ZZ Ceti to be 1.5 days.

  1. Comparative analysis of monetizing technologies for the use of offshore natural gas; Analise comparativa das tecnologias embarcadas de aproveitamento de gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Biruel Junior, Jose

    2008-09-15

    The growing world need for natural gas, the issue of offshore oil and associated gas exploration in regions constantly farther from the consumer market, and the law restrictions due to greenhouses gases emissions have stimulated the development of technologies intended to monetizing stranded gas reserves. In order to compare these technologies, a Multi Criteria Decision Analysis Methodology, based on fuzzy parameters, has been developed. The Methodology enables specialists to define analysis dimensions and criteria as well as to assign weight and ratings by means of linguistic variables, resulting in a general performance index for each technology. The Methodology has been applied in a case study to compare the floating technologies FCNG (Floating Compressed Natural Gas), FLNG (Floating Liquefied Natural Gas), FGTL (Floating Gas-to-Liquid) and FGTW (Floating Gas-to- Wire). The efficacy of the Methodology depends on the comprehensiveness and quality of the information provided. Therefore, this dissertation presents a study of these technologies, placing strong emphasis on the Technological Dimension. The Methodology allows for the identification of the drawbacks of each technology so as to especially conduct R and D efforts to improve their competitiveness. (author)

  2. Evolution of evolvability in gene regulatory networks.

    Directory of Open Access Journals (Sweden)

    Anton Crombach

    Full Text Available Gene regulatory networks are perhaps the most important organizational level in the cell where signals from the cell state and the outside environment are integrated in terms of activation and inhibition of genes. For the last decade, the study of such networks has been fueled by large-scale experiments and renewed attention from the theoretical field. Different models have been proposed to, for instance, investigate expression dynamics, explain the network topology we observe in bacteria and yeast, and for the analysis of evolvability and robustness of such networks. Yet how these gene regulatory networks evolve and become evolvable remains an open question. An individual-oriented evolutionary model is used to shed light on this matter. Each individual has a genome from which its gene regulatory network is derived. Mutations, such as gene duplications and deletions, alter the genome, while the resulting network determines the gene expression pattern and hence fitness. With this protocol we let a population of individuals evolve under Darwinian selection in an environment that changes through time. Our work demonstrates that long-term evolution of complex gene regulatory networks in a changing environment can lead to a striking increase in the efficiency of generating beneficial mutations. We show that the population evolves towards genotype-phenotype mappings that allow for an orchestrated network-wide change in the gene expression pattern, requiring only a few specific gene indels. The genes involved are hubs of the networks, or directly influencing the hubs. Moreover, throughout the evolutionary trajectory the networks maintain their mutational robustness. In other words, evolution in an alternating environment leads to a network that is sensitive to a small class of beneficial mutations, while the majority of mutations remain neutral: an example of evolution of evolvability.

  3. Analysis of Petroleum Products in Fire Debris Residues by Gas Chromatography: A Literature Review

    Directory of Open Access Journals (Sweden)

    Gurvinder Singh Bumbrah

    2017-06-01

    Full Text Available This review gives a brief overview of developments in the analysis of petroleum products (PP in fire debris residues (FDR by gas chromatography (GC. The review covers different aspects of analysis such as the substrates involved, isolation procedures, column and mobile phase used, and subsequent detection in tabular form. This paper covers detection of PP such as petrol, kerosene, and diesel in various types’ of samples of interest to fire debris analysts. Solid phase microextraction is most frequently used along with gas chromatography-mass spectrometry (GC-MS for the extraction and identification of PP from FDR. Chemometric tools should be used to improve the significance and reliability of results obtained from the analysis of FDR. However, the potential utility of portable GC-MS in fire debris analysis cannot be ignored, and its proper development and validation is required before using it for this purpose.

  4. When did oxygenic photosynthesis evolve?

    National Research Council Canada - National Science Library

    Roger Buick

    2008-01-01

    ...2.4 Ga ago, but when the photosynthetic oxygen production began is debatable. However, geological and geochemical evidence from older sedimentary rocks indicates that oxygenic photosynthesis evolved well before this oxygenation event...

  5. Marshal: Maintaining Evolving Models Project

    Data.gov (United States)

    National Aeronautics and Space Administration — SIFT proposes to design and develop the Marshal system, a mixed-initiative tool for maintaining task models over the course of evolving missions. Marshal-enabled...

  6. Natural selection promotes antigenic evolvability.

    Science.gov (United States)

    Graves, Christopher J; Ros, Vera I D; Stevenson, Brian; Sniegowski, Paul D; Brisson, Dustin

    2013-01-01

    The hypothesis that evolvability - the capacity to evolve by natural selection - is itself the object of natural selection is highly intriguing but remains controversial due in large part to a paucity of direct experimental evidence. The antigenic variation mechanisms of microbial pathogens provide an experimentally tractable system to test whether natural selection has favored mechanisms that increase evolvability. Many antigenic variation systems consist of paralogous unexpressed 'cassettes' that recombine into an expression site to rapidly alter the expressed protein. Importantly, the magnitude of antigenic change is a function of the genetic diversity among the unexpressed cassettes. Thus, evidence that selection favors among-cassette diversity is direct evidence that natural selection promotes antigenic evolvability. We used the Lyme disease bacterium, Borrelia burgdorferi, as a model to test the prediction that natural selection favors amino acid diversity among unexpressed vls cassettes and thereby promotes evolvability in a primary surface antigen, VlsE. The hypothesis that diversity among vls cassettes is favored by natural selection was supported in each B. burgdorferi strain analyzed using both classical (dN/dS ratios) and Bayesian population genetic analyses of genetic sequence data. This hypothesis was also supported by the conservation of highly mutable tandem-repeat structures across B. burgdorferi strains despite a near complete absence of sequence conservation. Diversification among vls cassettes due to natural selection and mutable repeat structures promotes long-term antigenic evolvability of VlsE. These findings provide a direct demonstration that molecular mechanisms that enhance evolvability of surface antigens are an evolutionary adaptation. The molecular evolutionary processes identified here can serve as a model for the evolution of antigenic evolvability in many pathogens which utilize similar strategies to establish chronic infections.

  7. Natural selection promotes antigenic evolvability.

    Directory of Open Access Journals (Sweden)

    Christopher J Graves

    Full Text Available The hypothesis that evolvability - the capacity to evolve by natural selection - is itself the object of natural selection is highly intriguing but remains controversial due in large part to a paucity of direct experimental evidence. The antigenic variation mechanisms of microbial pathogens provide an experimentally tractable system to test whether natural selection has favored mechanisms that increase evolvability. Many antigenic variation systems consist of paralogous unexpressed 'cassettes' that recombine into an expression site to rapidly alter the expressed protein. Importantly, the magnitude of antigenic change is a function of the genetic diversity among the unexpressed cassettes. Thus, evidence that selection favors among-cassette diversity is direct evidence that natural selection promotes antigenic evolvability. We used the Lyme disease bacterium, Borrelia burgdorferi, as a model to test the prediction that natural selection favors amino acid diversity among unexpressed vls cassettes and thereby promotes evolvability in a primary surface antigen, VlsE. The hypothesis that diversity among vls cassettes is favored by natural selection was supported in each B. burgdorferi strain analyzed using both classical (dN/dS ratios and Bayesian population genetic analyses of genetic sequence data. This hypothesis was also supported by the conservation of highly mutable tandem-repeat structures across B. burgdorferi strains despite a near complete absence of sequence conservation. Diversification among vls cassettes due to natural selection and mutable repeat structures promotes long-term antigenic evolvability of VlsE. These findings provide a direct demonstration that molecular mechanisms that enhance evolvability of surface antigens are an evolutionary adaptation. The molecular evolutionary processes identified here can serve as a model for the evolution of antigenic evolvability in many pathogens which utilize similar strategies to establish

  8. Parallel Hybrid Gas-Electric Geared Turbofan Engine Conceptual Design and Benefits Analysis

    Science.gov (United States)

    Lents, Charles; Hardin, Larry; Rheaume, Jonathan; Kohlman, Lee

    2016-01-01

    The conceptual design of a parallel gas-electric hybrid propulsion system for a conventional single aisle twin engine tube and wing vehicle has been developed. The study baseline vehicle and engine technology are discussed, followed by results of the hybrid propulsion system sizing and performance analysis. The weights analysis for the electric energy storage & conversion system and thermal management system is described. Finally, the potential system benefits are assessed.

  9. Analysis of Petroleum Products in Fire Debris Residues by Gas Chromatography: A Literature Review

    OpenAIRE

    Gurvinder Singh Bumbrah; Rajinder Kumar Sarin; Rakesh Mohan Sharma

    2017-01-01

    This review gives a brief overview of developments in the analysis of petroleum products (PP) in fire debris residues (FDR) by gas chromatography (GC). The review covers different aspects of analysis such as the substrates involved, isolation procedures, column and mobile phase used, and subsequent detection in tabular form. This paper covers detection of PP such as petrol, kerosene, and diesel in various types’ of samples of interest to fire debris analysts. Solid phase microextraction is mo...

  10. Carbohydrate analysis of hemicelluloses by gas chromatography-mass spectrometry of acteylated methyl glycosides

    DEFF Research Database (Denmark)

    Sárossy, Zsuzsa; Plackett, David; Egsgaard, Helge

    2012-01-01

    A method based on gas chromatography–mass spectrometry analysis of acetylated methyl glycosides was developed in order to analyze monosaccharides obtained from various hemicelluloses. The derivatives of monosaccharide standards, arabinose, glucose, and xylose were studied in detail and 13C-labele......-labeled analogues were used for identification and quantitative analysis. Excellent chromatographic separation of the monosaccharide derivatives was found and identification of the anomeric configuration was feasible through a prepared and identified pure methyl 2,3,4,6-tetra...

  11. Peripheral venous blood gas analysis: An alternative to arterial blood gas analysis for initial assessment and resuscitation in emergency and intensive care unit patients.

    Science.gov (United States)

    Awasthi, Shilpi; Rani, Raka; Malviya, Deepak

    2013-01-01

    Arterial blood gas (ABG) analysis is the gold standard method for assessment of oxygenation and acid base analysis, yielding valuable information about a variety of disease process. This study is aimed to determine the extent of correlation between arterial and peripheral venous samples for blood gases and acid base status in critically ill and emergency department patients and to evaluate if venous sample may be a better alternative for initial assessment and resuscitation. The prospective study was conducted on 45 patients of either sex in the age group of 15-80 years of intensive care unit and emergency ward. Relevant history, presenting complaints, vital signs, and indication for testing were recorded. Arterial and peripheral venous samples were drawn simultaneously in a pre-heparinized syringe and analyzed immediately for blood gases and acid base status. Mean difference and Pearson's product moment correlation coefficient was used to compare the result. After statistical evaluation, the present study shows minimal mean difference and good correlation (r > 0.9) between arterial and peripheral venous sample for blood gases and acid base status. Correlation in PO2 measurement was poor (r blood may be a useful alternative to arterial blood during blood gas analysis obviating the need for arterial puncture in difficult clinical situation especially trauma patients, for initial emergency department assessment and early stages of resuscitation.

  12. Exergy analysis of offshore processes on North Sea oil and gas platforms

    DEFF Research Database (Denmark)

    Nguyen, Tuong-Van; Pierobon, Leonardo; Elmegaard, Brian

    2012-01-01

    generation. In this paper, the most thermodynamically inefficient processes are identified by performing an exergy analysis, based on models built with the simulation tools Aspen Plus®, DNA and Aspen HYSYS®. Results reveal that the total exergy destruction of the system amounts to 69.4 MW, while the total...... exergy losses amount to 22.3 MW. The gas lifting train and the production-separation module are the most exergy-destructive operations of the oil and gas processing system, consuming 8.83 MW and 8.17 MW respectively, while the power generation system alone is responsible for 46.7 MW. The exergetic...

  13. Stability analysis and testing of a train of centrifugal compressors for high pressure gas injection

    Energy Technology Data Exchange (ETDEWEB)

    Memmott, E.A. [Dresser-Rand Co., Olean, NY (United States)

    1999-07-01

    This paper describes the rotor dynamic stability analysis and the PTC-10 Class 1 test of a three body centrifugal compressor train for high pressure natural gas injection services. This train had a full load full pressure string test on hydrocarbon gases to a final discharge pressure of 500 BAR (7250 PSIA). Each compressor is of the back to back configuration, and is equipped with tilting pad seals, damper bearings, and a honeycomb labyrinth at the division wall with shunt holes. The driver is a gas turbine.

  14. CHEMICAL ANALYSIS OF DENSE-GAS EXTRACTS FROM LIME FLOWERS

    Directory of Open Access Journals (Sweden)

    Demyanenko DV

    2015-04-01

    Full Text Available The purpose of this work was to make qualitative and quantitative analysis of phenolic biologically active substances (BAS in the extracts produced from lime flowers with condensed gases, using method of high-performance liquid chromatography (HPLC. Materials and methods: materials for this study were the extracts obtained by consequent processing of the herbal drug and marcs thereof with various condensed gases: difluorochloromethane (Freon R22, difluoromethane (Freon R32, azeotropic mixture of difluoromethane with pentafluoroethane (Freon 410A and freon-ammonium mixture. Extracts obtained with the latter were subjected to further fractionation by liquidliquid separation into hexane, chloroform, ethyl acetate and aqueous-alcohol phases. Besides, the supercritical СО2 extract, obtained from the herbal drug under rather strong conditions (at temperature 60°С and pressure 400 bar, was studied in our previous research. Presence of phenolic BAS and their quantity in the researched samples were determined by method of HPLC with UVspectrometric detection. Results and discussion: It has been found that Freon R22 extracted trace amounts of rutin from lime flowers – its content was only 0.08% of the total extract weight. On the other hand, Freons R32 and R410А showed good selectivity to moderately polar BAS of lime flowers (derivatives of flavonoids and hydroxycinnamic acids: in particular, the extract obtained with freon R32 contained about 1.3% of the total phenolic substances, and it was the only one of the investigated condensed gases used by us which took the basic flavonoid of lime flowers tiliroside – its content was 0.42% of extract weight. Also Freons R32 and R410А were able to withdraw another compound dominating among phenolic substances in the yielded extracts. Its quantity was rather noticeable – up to 0.87% of extract weight. This substance was not identified by existing database, but its UV-spectrum was similar to those of

  15. Life Cycle Greenhouse Gas Analysis of Multiple Vehicle Fuel Pathways in China

    Directory of Open Access Journals (Sweden)

    Tianduo Peng

    2017-11-01

    Full Text Available The Tsinghua University Life Cycle Analysis Model (TLCAM is applied to calculate the life cycle fossil energy consumption and greenhouse gas (GHG emissions for more than 20 vehicle fuel pathways in China. In addition to conventional gasoline and diesel, these include coal- and gas-based vehicle fuels, and electric vehicle (EV pathways. The results indicate the following. (1 China’s current dependence on coal and relative low-efficiency processes limits the potential for most alternative fuel pathways to decrease energy consumption and emissions; (2 Future low-carbon electricity pathways offer more obvious advantages, with coal-based pathways needing to adopt carbon dioxide capture and storage technology to compete; (3 A well-to-wheels analysis of the fossil energy consumption of vehicles fueled by compressed natural gas and liquefied natural gas (LNG showed that they are comparable to conventional gasoline vehicles. However, importing rather than domestically producing LNG for vehicle use can decrease domestic GHG emissions by 35% and 31% compared with those of conventional gasoline and diesel vehicles, respectively; (4 The manufacturing and recovery of battery and vehicle in the EV analysis has significant impact on the overall ability of EVs to decrease fossil energy consumption and GHG emissions from ICEVs.

  16. Development of a new method for hydrogen isotope analysis of trace hydrocarbons in natural gas samples

    Directory of Open Access Journals (Sweden)

    Xibin Wang

    2016-12-01

    Full Text Available A new method had been developed for the analysis of hydrogen isotopic composition of trace hydrocarbons in natural gas samples by using solid phase microextraction (SPME combined with gas chromatography-isotope ratio mass spectrometry (GC/IRMS. In this study, the SPME technique had been initially introduced to achieve the enrichment of trace content of hydrocarbons with low abundance and coupled to GC/IRMS for hydrogen isotopic analysis. The main parameters, including the equilibration time, extraction temperature, and the fiber type, were systematically optimized. The results not only demonstrated that high extraction yield was true but also shows that the hydrogen isotopic fractionation was not observed during the extraction process, when the SPME device fitted with polydimethylsiloxane/divinylbenzene/carbon molecular sieve (PDMS/DVB/CAR fiber. The applications of SPME-GC/IRMS method were evaluated by using natural gas samples collected from different sedimentary basins; the standard deviation (SD was better than 4‰ for reproducible measurements; and also, the hydrogen isotope values from C1 to C9 can be obtained with satisfying repeatability. The SPME-GC/IRMS method fitted with PDMS/DVB/CAR fiber is well suited for the preconcentration of trace hydrocarbons, and provides a reliable hydrogen isotopic analysis for trace hydrocarbons in natural gas samples.

  17. Fuzzy Bayesian Network-Bow-Tie Analysis of Gas Leakage during Biomass Gasification

    Science.gov (United States)

    Yan, Fang; Xu, Kaili; Yao, Xiwen; Li, Yang

    2016-01-01

    Biomass gasification technology has been rapidly developed recently. But fire and poisoning accidents caused by gas leakage restrict the development and promotion of biomass gasification. Therefore, probabilistic safety assessment (PSA) is necessary for biomass gasification system. Subsequently, Bayesian network-bow-tie (BN-bow-tie) analysis was proposed by mapping bow-tie analysis into Bayesian network (BN). Causes of gas leakage and the accidents triggered by gas leakage can be obtained by bow-tie analysis, and BN was used to confirm the critical nodes of accidents by introducing corresponding three importance measures. Meanwhile, certain occurrence probability of failure was needed in PSA. In view of the insufficient failure data of biomass gasification, the occurrence probability of failure which cannot be obtained from standard reliability data sources was confirmed by fuzzy methods based on expert judgment. An improved approach considered expert weighting to aggregate fuzzy numbers included triangular and trapezoidal numbers was proposed, and the occurrence probability of failure was obtained. Finally, safety measures were indicated based on the obtained critical nodes. The theoretical occurrence probabilities in one year of gas leakage and the accidents caused by it were reduced to 1/10.3 of the original values by these safety measures. PMID:27463975

  18. Fuzzy Bayesian Network-Bow-Tie Analysis of Gas Leakage during Biomass Gasification.

    Directory of Open Access Journals (Sweden)

    Fang Yan

    Full Text Available Biomass gasification technology has been rapidly developed recently. But fire and poisoning accidents caused by gas leakage restrict the development and promotion of biomass gasification. Therefore, probabilistic safety assessment (PSA is necessary for biomass gasification system. Subsequently, Bayesian network-bow-tie (BN-bow-tie analysis was proposed by mapping bow-tie analysis into Bayesian network (BN. Causes of gas leakage and the accidents triggered by gas leakage can be obtained by bow-tie analysis, and BN was used to confirm the critical nodes of accidents by introducing corresponding three importance measures. Meanwhile, certain occurrence probability of failure was needed in PSA. In view of the insufficient failure data of biomass gasification, the occurrence probability of failure which cannot be obtained from standard reliability data sources was confirmed by fuzzy methods based on expert judgment. An improved approach considered expert weighting to aggregate fuzzy numbers included triangular and trapezoidal numbers was proposed, and the occurrence probability of failure was obtained. Finally, safety measures were indicated based on the obtained critical nodes. The theoretical occurrence probabilities in one year of gas leakage and the accidents caused by it were reduced to 1/10.3 of the original values by these safety measures.

  19. Fuzzy Bayesian Network-Bow-Tie Analysis of Gas Leakage during Biomass Gasification.

    Science.gov (United States)

    Yan, Fang; Xu, Kaili; Yao, Xiwen; Li, Yang

    2016-01-01

    Biomass gasification technology has been rapidly developed recently. But fire and poisoning accidents caused by gas leakage restrict the development and promotion of biomass gasification. Therefore, probabilistic safety assessment (PSA) is necessary for biomass gasification system. Subsequently, Bayesian network-bow-tie (BN-bow-tie) analysis was proposed by mapping bow-tie analysis into Bayesian network (BN). Causes of gas leakage and the accidents triggered by gas leakage can be obtained by bow-tie analysis, and BN was used to confirm the critical nodes of accidents by introducing corresponding three importance measures. Meanwhile, certain occurrence probability of failure was needed in PSA. In view of the insufficient failure data of biomass gasification, the occurrence probability of failure which cannot be obtained from standard reliability data sources was confirmed by fuzzy methods based on expert judgment. An improved approach considered expert weighting to aggregate fuzzy numbers included triangular and trapezoidal numbers was proposed, and the occurrence probability of failure was obtained. Finally, safety measures were indicated based on the obtained critical nodes. The theoretical occurrence probabilities in one year of gas leakage and the accidents caused by it were reduced to 1/10.3 of the original values by these safety measures.

  20. Robustness of arterial blood gas analysis for assessment of respiratory safety pharmacology in rats.

    Science.gov (United States)

    Whiteside, Garth T; Hummel, Michele; Boulet, Jamie; Beyenhof, Jessica D; Strenkowski, Bryan; John, Janet Dell; Knappenberger, Terri; Maselli, Harry; Koetzner, Lee

    2016-01-01

    Whole body plethysmography using unrestrained animals is a common technique for assessing the respiratory risk of new drugs in safety pharmacology studies in rats. However, wide variations in experimental technique make cross laboratory comparison of data difficult and raise concerns that non-appropriate conditions may mask the deleterious effects of test compounds - in particular with suspected respiratory depressants. Therefore, the objective of this study was to evaluate the robustness of arterial blood gas analysis as an alternative to plethysmography in rats. We sought to do this by assessing the effect of different vehicles and times post-surgical catheterization on blood gas measurements, in addition to determining sensitivity to multiple opioids. Furthermore, we determined intra-lab variability from multiple datasets utilizing morphine and generated within a single lab and lastly, inter-lab variability was measured by comparing datasets generated in two separate labs. Overall, our data show that arterial blood gas analysis is a measure that is both flexible in terms of experimental conditions and highly sensitive to respiratory depressants, two key limitations when using plethysmography. As such, our data strongly advocate the adoption of arterial blood gas analysis as an investigative approach to reliably examine the respiratory depressant effects of opioids. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Multivariate data analysis to characterize gas chromatography columns for dioxin analysis.

    Science.gov (United States)

    Do, Lan; Geladi, Paul; Haglund, Peter

    2014-06-20

    dipolar moment. Finally, the PCA and PLS analyses were complemented with linear regression analysis to identify the most orthogonal column combinations, which could be used in comprehensive two-dimensional gas chromatography (GC×GC) to enhance PCDD/F separation and congener profiling. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Heat transfer analysis of unsteady graphene oxide nanofluid flow using a fuzzy identifier evolved by genetically encoded mutable smart bee algorithm

    Directory of Open Access Journals (Sweden)

    Mohammadreza Azimi

    2015-03-01

    Full Text Available In the current research, the unsteady two dimensional Graphene Oxide water based nanofluid heat transfer between two moving parallel plates is analyzed using an intelligent black-box identifier. The developed intelligent tool is known as evolvable evolutionary fuzzy inference system (EE-FIS which is based on the integration of low-level fuzzy programming and hyper-level evolutionary computing concepts. Here, the authors propose the use of a modified evolutionary algorithm (EA which is called hybrid genetic mutable smart bee algorithm (HGMSBA. The proposed HGMSBA is used to evolve both antecedent and consequent parts of fuzzy rule base. Besides, it tries to prune the rule base of fuzzy inference system (FIS to decrease its computational complexity and increase its interpretability. By considering the prediction error of the fuzzy identifier as the objective function of HGMSBA, an automatic soft interpolation machine is developed which can intuitively increase the robustness and accuracy of the final model. Here, HGMSBA-FIS is used to provide a nonlinear map between inputs, i.e. nanoparticles solid volume fraction (ϕ, Eckert number (Ec and a moving parameter which describes the movements of plates (S, and output, i.e. Nusselt number (Nu. Prior to proceeding with the modeling process, a comprehensive numerical comparative study is performed to investigate the potentials of the proposed model for nonlinear system identification. After demonstrating the efficacy of HGMSBA for training the FIS, the system is applied to the considered problem. Based on the obtained results, it can be inferred that the developed HGMSBA-FIS black-box identifier can be used as a very authentic tool with respect to accuracy and robustness. Besides, as the proposed black-box is not a physics-based identifier, it frees experts from the cumbersome mathematical formulations, and can be used for advanced real-time applications such as model-based control. The simulations

  3. Metabolic memory: Evolving concepts.

    Science.gov (United States)

    Misra, Anoop; Bloomgarden, Zachary

    2018-03-01

    HbA1c at the time of diagnosis simply reflect a brief period of glycemic exposure, so that it would not be expected to be of consequence? The ratio of undiagnosed to diagnosed diabetes in National Health and Nutrition Surveys (NHANES) carried out from 1999 to 2010, and from 2011 to 2012, is roughly 1: 2, suggesting that at the time of initial diagnosis diabetes often may be present for a substantial period, implying that prediagnosis exposure to elevated glucose levels has a bearing on subsequent outcome. Bianchi and del Prato suggest an interesting interpretation of "bad glycemic legacy" based on the Veterans Administration Diabetes Trial (VADT). In that study, 1791 military veterans with a mean diabetes duration of 11.5 years and poor diabetes control, with baseline HbA1c 9.4%, and assigned to intensive or standard treatment arms showed no overall differences in macrovascular or microvascular endpoints after a median follow-up of 5.6 years. Perhaps, then, uncontrolled glycemia of long duration may not be offset by subsequent intensive control, but intensive treatment from the time of diagnosis, even with "bad glycemic legacy" (but of short duration), will be effective in decreasing risk of later complications. Does the retrospective study by Pantalone et al. hint at a different aspect of metabolic memory, namely that poor control of glycemia at baseline does not affect the development of complications later if it is effectively managed subsequently? That effects of initial hyperglycemia could be dispelled with excellent glycemic control? Such an interpretation gives cause for optimism and can be used in empowering people developing diabetes to participate in their care. Analysis of more datasets with serial measures of HbA1c may allow us to further understand these relationships, and certainly the underlying molecular mechanisms of metabolic memory deserve further investigation. © 2017 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and John Wiley

  4. Glass bottle sampling solid phase microextraction gas chromatography mass spectrometry for breath analysis of drug metabolites.

    Science.gov (United States)

    Lu, Yan; Niu, Wenqi; Zou, Xue; Shen, Chengyin; Xia, Lei; Huang, Chaoqun; Wang, Hongzhi; Jiang, Haihe; Chu, Yannan

    2017-05-05

    Breath analysis is a non-invasive approach which may be applied to disease diagnosis and pharmacokinetic study. In the case of offline analysis, the exhaled gas needs to be collected and the sampling bag is often used as the storage vessel. However, the sampling bag usually releases some extra compounds, which may interfere with the result of the breath test. In this study, a novel breath sampling glass bottle was developed with a syringe needle sampling port for solid phase microextraction (SPME). Such a glass bottle scarcely liberates compounds and can be used to collect exhaled gas for ensuing analysis by gas chromatography-mass spectrometry (GC-MS). The glass bottle sampling SPME-GC-MS analysis was carried out to investigate the breath metabolites of myrtol, a multicompound drug normally used in the treatment of bronchitis and sinusitis. Four compounds, α-pinene, 2,3-dehydro-1,8-cineole, d-limonene and 1,8-cineole were found in the exhaled breath of all eight volunteers who had taken the myrtol. While for other ten subjects who had not used the myrtol, these compounds were undetectable. In the SPME-GC-MS analysis of the headspace of myrtol, three compounds were detected including α-pinene, d-limonene and 1,8-cineole. Comparing the results of breath and headspace analysis, it indicates that 2,3-dehydro-1,8-cineole in the breath is the metabolite of 1,8-cineole. It is the first time that this metabolite was identified in human breath. The study demonstrates that the glass bottle sampling SPME-GC-MS method is applicable to exhaled gas analysis including breath metabolites investigation of drugs like myrtol. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Analysis of Critical Permeabilty, Capillary Pressure and Electrical Properties for Mesaverde Tight Gas Sandstones from Western U.S. Basins

    Energy Technology Data Exchange (ETDEWEB)

    Alan Byrnes; Robert Cluff; John Webb; John Victorine; Ken Stalder; Daniel Osburn; Andrew Knoderer; Owen Metheny; Troy Hommertzheim; Joshua Byrnes; Daniel Krygowski; Stefani Whittaker

    2008-06-30

    Although prediction of future natural gas supply is complicated by uncertainty in such variables as demand, liquefied natural gas supply price and availability, coalbed methane and gas shale development rate, and pipeline availability, all U.S. Energy Information Administration gas supply estimates to date have predicted that Unconventional gas sources will be the dominant source of U.S. natural gas supply for at least the next two decades (Fig. 1.1; the period of estimation). Among the Unconventional gas supply sources, Tight Gas Sandstones (TGS) will represent 50-70% of the Unconventional gas supply in this time period (Fig. 1.2). Rocky Mountain TGS are estimated to be approximately 70% of the total TGS resource base (USEIA, 2005) and the Mesaverde Group (Mesaverde) sandstones represent the principal gas productive sandstone unit in the largest Western U.S. TGS basins including the basins that are the focus of this study (Washakie, Uinta, Piceance, northern Greater Green River, Wind River, Powder River). Industry assessment of the regional gas resource, projection of future gas supply, and exploration programs require an understanding of reservoir properties and accurate tools for formation evaluation. The goal of this study is to provide petrophysical formation evaluation tools related to relative permeability, capillary pressure, electrical properties and algorithms for wireline log analysis. Detailed and accurate moveable gas-in-place resource assessment is most critical in marginal gas plays and there is need for quantitative tools for definition of limits on gas producibility due to technology and rock physics and for defining water saturation. The results of this study address fundamental questions concerning: (1) gas storage; (2) gas flow; (3) capillary pressure; (4) electrical properties; (5) facies and upscaling issues; (6) wireline log interpretation algorithms; and (7) providing a web-accessible database of advanced rock properties. The following text

  6. Doping control analysis of anabolic steroids in equine urine by gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Wong, April S Y; Leung, Gary N W; Leung, David K K; Wan, Terence S M

    2017-09-01

    Anabolic steroids are banned substances in equine sports. Gas chromatography-mass spectrometry (GC-MS) has been the traditional technique for doping control analysis of anabolic steroids in biological samples. Although liquid chromatography-mass spectrometry (LC/MS) has become an important technique in doping control, the detection of saturated hydroxysteroids by LC-MS remains a problem due to their low ionization efficiency under electrospray. The recent development in fast-scanning gas-chromatography-triple-quadrupole mass spectrometry (GC-MS/MS) has provided a better alternative with a significant reduction in chemical noise by means of selective reaction monitoring. Herein, we present a sensitive and selective method for the screening of over 50 anabolic steroids in equine urine using gas chromatography-tandem mass spectrometry (GC-MS/MS). Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  7. Finite element analysis of radiant heating systems based on gas-fired infrared heat emitters

    Directory of Open Access Journals (Sweden)

    Ermolaev Anton N.

    2017-01-01

    Full Text Available The article presents a finite element model for simulating a gas-fired IR radiation system. Simulation of gaseous combustion and discrete ordinates radiation model were used to solve a number of heat-transfer problems in ventilated rooms with radiant heating. We used Ansys Multiphysics software and Fluent CFD solver for implementing finite element analysis. To solve differential equations of heating and gas dynamics, the following boundary conditions were considered. Dry methane was used as the fuel and air with 21% of oxygen, as oxidizer. Fuel consumption was 0.5 m3/hour; the gas pressure before the nozzle was 1270 Pa. The air–fuel ratio was 9.996.

  8. A new method of leak location for the natural gas pipeline based on wavelet analysis

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhao; Xiong, Zhuang; Shao, Min [Thermal Energy Research Institute, School of Mechanical Engineering, Tianjin University, Nankai District, Tianjin 300072 (China)

    2010-09-15

    This paper analyzes the properties of wavelet transform and its potential application in detecting the leakage location of gas pipeline. An entity-part method, which is proposed for the accurate leaking point, has been proved valid in the stimulation experiment. In addition, method of Romberg and Dichotomy Searching are also adopted for the computational analysis of leaking point. In detail, the effect of gas velocity is taken into consideration in the location formula and we propose to consider the average velocities of two parts caused by the leaking point, respectively. Finally, we test these three methods in a real gas pipeline experiment and the result shows the improvement to some extent in contrast to the traditional approach. (author)

  9. Gaz Türbinlerinin Optimal Performans Analizi = Optimal Performance Analysis of Gas Turbines

    Directory of Open Access Journals (Sweden)

    Burhanettin ÇETİN

    2006-01-01

    Full Text Available The usage of gas turbines increases rapidly in the electricity production and cogeneration systems in recent years. Decreasing performance of gas turbines causes not only reducing their capacity of electricity production but also increasing production cost. In this study, the thermodynamic analysis of the open cycle gas turbine model is examined. The power output and the thermal efficiency of system are chosen as the performance criteria and the effects of compressor pressure ratio, turbine inlet temperature, isentropic efficiencies and pressure losses on the performance are analyzed. Developed model has been solved by using the computer program written in Visual Basic language and the design parameters giving maximum power and efficiency are determined.

  10. Analysis of main gaseous emissions of heavy duty gas turbines burning several syngas fuels

    Energy Technology Data Exchange (ETDEWEB)

    Chacartegui, R.; Torres, M.; Sanchez, D.; Jimenez, F.; Munoz, A.; Sanchez, T. [Escuela Tecnica Superior de Ingenieros, Sevilla (Spain)

    2011-02-15

    This work presents the development of a simple analytical model of performance for heavy duty gas turbine combustors and its use for the analysis of main emissions for a set of syngas fuels. This set of syngas fuels has been selected as a wide representation of different compositions of syngas fuels, from fossil or vegetal origins. Their combustion processes have been modelled as a set of chemical reactors in serial and a detailed kinetic model, simulating a conventional diffusion flame combustor. In each slice, the thermodynamics and the kinetics have been modelled using perfect stirred reactor models. The combustor model has been validated with the GE MS7001F gas turbine experimental data. From this validation the model applicability range has been established for combustor outlet temperatures above 1200 K. Finally the combustor model has been applied to the comparison of different syngas fuels emissions in three new generation gas turbines. (author)

  11. [The practice of neonatal umbilical blood gas analysis in the "Alsace" regional French perinatal network].

    Science.gov (United States)

    Kellenberger, F; Akladios, C Y; Sananes, N; Gaudineau, A; Langer, B

    2016-10-01

    The assessment of neonatal well-being is paramount in delivery rooms. For that purpose, it is recommended in France to carry out a systematic neonatal umbilical cord blood gas analysis. The aim of this study is to evaluate how umbilical cord blood gas sampling is realised, analysed and interpreted by midwives in a French regional perinatal network. We conducted a survey focused on randomly selected midwives partitioning in different maternities that constitute the "Alsace" regional perinatal network. A questionnaire concerning the modalities of umbilical cord blood sampling, its analysis and the interpretation of results was used during interviews with included midwives. Fifty-one midwives were included in the study (15.8% of whom were working in delivery rooms). Only 13% of maternities constituting the perinatal network did not realise systematic neonatal umbilical cord blood analysis. Among interviewed midwives, 78.4% reported umbilical cord clamping after the first breath of the child. Among the midwives included, 86.3% of them realise sampling from the umbilical artery and 29.4% from both umbilical artery and vein. For 86.3% of interviewed midwives, the leitmotif of realising umbilical blood sampling was medico-legal. More than two third of included midwives interpret blood gas taking into account two parameters (either pH and base excess, or lactate). They settled at 7.0-7.2, the limit below which a newborn might present sequelae. This study shows that the neonatal umbilical cord blood gas analysis at birth is almost systematic in this regional French perinatal network. It is realised primarily for medico-legal purpose. However, there are significant variations in sampling procedures and interpretation. This should lead to the establishment within each maternity of a neonatal umbilical cord blood gas sampling protocol along with a midwifery training program. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  12. Risk analysis of urban gas pipeline network based on improved bow-tie model

    Science.gov (United States)

    Hao, M. J.; You, Q. J.; Yue, Z.

    2017-11-01

    Gas pipeline network is a major hazard source in urban areas. In the event of an accident, there could be grave consequences. In order to understand more clearly the causes and consequences of gas pipeline network accidents, and to develop prevention and mitigation measures, the author puts forward the application of improved bow-tie model to analyze risks of urban gas pipeline network. The improved bow-tie model analyzes accident causes from four aspects: human, materials, environment and management; it also analyzes the consequences from four aspects: casualty, property loss, environment and society. Then it quantifies the causes and consequences. Risk identification, risk analysis, risk assessment, risk control, and risk management will be clearly shown in the model figures. Then it can suggest prevention and mitigation measures accordingly to help reduce accident rate of gas pipeline network. The results show that the whole process of an accident can be visually investigated using the bow-tie model. It can also provide reasons for and predict consequences of an unfortunate event. It is of great significance in order to analyze leakage failure of gas pipeline network.

  13. Comparative Analysis of Volatile Defensive Secretions of Three Species of Pyrrhocoridae (Insecta: Heteroptera) by Gas Chromatography-Mass Spectrometric Method.

    Science.gov (United States)

    Krajicek, Jan; Havlikova, Martina; Bursova, Miroslava; Ston, Martin; Cabala, Radomir; Exnerova, Alice; Stys, Pavel; Bosakova, Zuzana

    2016-01-01

    The true bugs (Hemiptera: Heteroptera) have evolved a system of well-developed scent glands that produce diverse and frequently strongly odorous compounds that act mainly as chemical protection against predators. A new method of non-lethal sampling with subsequent separation using gas chromatography with mass spectrometric detection was proposed for analysis of these volatile defensive secretions. Separation was performed on Rtx-200 column containing fluorinated polysiloxane stationary phase. Various mechanical irritation methods (ultrasonics, shaking, pressing bugs with plunger of syringe) were tested for secretion sampling with a special focus on non-lethal irritation. The preconcentration step was performed by sorption on solid phase microextraction (SPME) fibers with different polarity. For optimization of sampling procedure, Pyrrhocoris apterus was selected. The entire multi-parameter optimization procedure of secretion sampling was performed using response surface methodology. The irritation of bugs by pressing them with a plunger of syringe was shown to be the most suitable. The developed method was applied to analysis of secretions produced by adult males and females of Pyrrhocoris apterus, Pyrrhocoris tibialis and Scantius aegyptius (all Heteroptera: Pyrrhocoridae). The chemical composition of secretion, particularly that of alcohols, aldehydes and esters, is species-specific in all three pyrrhocorid species studied. The sexual dimorphism in occurrence of particular compounds is largely limited to alcohols and suggests their epigamic intraspecific function. The phenetic overall similarities in composition of secretion do not reflect either relationship of species or similarities in antipredatory color pattern. The similarities of secretions may be linked with antipredatory strategies. The proposed method requires only a few individuals which remain alive after the procedure. Thus secretions of a number of species including even the rare ones can be

  14. Accident Analysis Simulation in Modular 300MWt Gas Cooled Fast Reactor

    Science.gov (United States)

    Zaki, Su'ud

    2017-01-01

    Safety analysis of 300MWt helium gas cooled long-life fast reactors has been performed. The analysis of unprotected loss of flow(ULOF) and unprotected rod run-out transient overpower (UTOP) are discussed. Some simulations for 300 MWt He gas cooled fast reactors has been performed and the results show that the reactor can anticipate complete pumping failure inherently by reducing power through reactivity feedback and remove the rest of heat through natural circulations. GCFR relatively has hard spectrum so it has relatively small Doppler coefficient. In the UTOP accident case the analysis has been performed against external reactivity up to 0.002dk/k. In addition the steam generator design has also consider excess power during severe UTOP case..

  15. Sensitivity analysis and economic optimization studies of inverted five-spot gas cycling in gas condensate reservoir

    Directory of Open Access Journals (Sweden)

    Shams Bilal

    2017-08-01

    Full Text Available Gas condensate reservoirs usually exhibit complex flow behaviors because of propagation response of pressure drop from the wellbore into the reservoir. When reservoir pressure drops below the dew point in two phase flow of gas and condensate, the accumulation of large condensate amount occurs in the gas condensate reservoirs. Usually, the saturation of condensate accumulation in volumetric gas condensate reservoirs is lower than the critical condensate saturation that causes trapping of large amount of condensate in reservoir pores. Trapped condensate often is lost due to condensate accumulation-condensate blockage courtesy of high molecular weight, heavy condensate residue. Recovering lost condensate most economically and optimally has always been a challenging goal. Thus, gas cycling is applied to alleviate such a drastic loss in resources.

  16. Multiresidue analysis of pesticides in soil by gas chromatography with nitrogen-phosphorus detection and gas chromatography mass spectrometry.

    Science.gov (United States)

    Fenoll, José; Hellín, Pilar; Marín, Cristóbal; Martínez, Carmen M; Flores, Pilar

    2005-10-05

    A rapid multiresidue method for the simultaneous determination of 25 fungicides and insecticides in soil was developed. Soil samples are extracted by sonication with a water-acetonitrile mixture, and the pesticides are partitioned into dichloromethane. Final determination was made by gas chromatography (GC) with nitrogen-phosphorus detection (NPD). Confirmation analysis of pesticides was carried out by GC-MS in the selected ion monitoring (SIM) mode. The identification of compounds was based on retention time and on comparison of the primary and secondary ions. The average recovery by the GC-NPD method obtained for these compounds varied from 68.5% to 112.1% with a relative standard deviation between 1.8% and 6.2%. The GC-NPD method presents good linearity over the range assayed 50-2000 microg/L, and the detection limit for the pesticides studied varied from 0.1 to 10.4 microg/kg. The proposed method was used to determine pesticide levels in soil samples from experimental greenhouse pepper cultivation.

  17. Free volume analysis and gas transport mechanisms of aromatic polyimide membranes: a molecular simulation study.

    Science.gov (United States)

    Chang, Kai-Shiun; Tung, Chieng-Chi; Wang, Ko-Shung; Tung, Kuo-Lun

    2009-07-23

    Molecular simulation techniques were adopted to investigate membrane free volume morphologies and gas-transport mechanisms in the aromatic polyimide (PI) membranes composed of various diamines and dianhydrides. A molecular dynamics (MD) technique was adopted to analyze the fractional free volume (FFV), fractional accessible volume (FAV), free volume size and shape, and diffusion mechanisms. A Monte Carlo (MC) method was used to analyze the gas sorption behaviors in the membranes. The FFV, FAV, and free volume morphology analyses reveal that bulky groups in the PI membranes contributed to the formation of a larger and more continuous free volume. The thermal motion analysis shows that a greater effective free volume in the membranes promoted effective motion, such as jumping and diffusive motions. The sorption analysis indicates that the larger free volume provides more sites for gas molecule absorption. The MD and MC results provide good agreement with the experimental data from past reports, which validates the feasibility of molecular simulation techniques in gas separation membranes at a molecular scale.

  18. Humidity independent mass spectrometry for gas phase chemical analysis via ambient proton transfer reaction.

    Science.gov (United States)

    Zhu, Hongying; Huang, Guangming

    2015-03-31

    In this work, a humidity independent mass spectrometric method was developed for rapid analysis of gas phase chemicals. This method is based upon ambient proton transfer reaction between gas phase chemicals and charged water droplets, in a reaction chamber with nearly saturate humidity under atmospheric pressure. The humidity independent nature enables direct and rapid analysis of raw gas phase samples, avoiding time- and sample-consuming sample pretreatments in conventional mass spectrometry methods to control sample humidity. Acetone, benzene, toluene, ethylbenzene and meta-xylene were used to evaluate the analytical performance of present method. The limits of detection for benzene, toluene, ethylbenzene and meta-xylene are in the range of ∼0.1 to ∼0.3 ppbV; that of benzene is well below the present European Union permissible exposure limit for benzene vapor (5 μg m(-3), ∼1.44 ppbV), with linear ranges of approximately two orders of magnitude. The majority of the homemade device contains a stainless steel tube as reaction chamber and an ultrasonic humidifier as the source of charged water droplets, which makes this cheap device easy to assemble and facile to operate. In addition, potential application of this method was illustrated by the real time identification of raw gas phase chemicals released from plants at different physiological stages. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Effects of cystic fibrosis lung disease on gas mixing indices derived from alveolar slope analysis.

    Science.gov (United States)

    Horsley, Alex R; Macleod, Kenneth A; Robson, Andrew G; Lenney, Jill; Bell, Nicholas J; Cunningham, Steve; Greening, Andrew P; Gustafsson, Per M; Innes, J Alastair

    2008-08-31

    S(cond) and S(acin) are derived from analysis of concentration-normalized phase III slopes (Sn(III)) of a multiple breath inert gas washout. Studies in healthy and COPD subjects suggest these reflect ventilation heterogeneity in conducting and acinar airway zones respectively, but similar studies in cystic fibrosis (CF) are lacking. S(cond), S(acin) and lung clearance index (LCI, a measure of overall gas mixing efficiency) were measured in 22 adults and 18 children with CF and 17 adult and 29 child controls. Plethysmography and gas transfer measurements were performed in adults, and spirometry in all subjects. S(cond) was elevated in almost all CF patients, including children with mild disease and normal LCI. However, S(cond) did not correlate with other measurements and appeared to reach a maximum; further increase in ventilation heterogeneity being restricted to S(acin). The nature and/or severity of CF lung disease may invalidate assumptions underlying the ability to separate phase III slope analysis of ventilation heterogeneity into proximal and peripheral components, and LCI may be a better indicator of gas mixing in this population.

  20. Clinical, operational and economic outcomes of point-of-care blood gas analysis in COPD patients.

    Science.gov (United States)

    Oliver, Paloma; Buno, Antonio; Alvarez-Sala, Rodolfo; Fernandez-Calle, Pilar; Alcaide, Maria Jose; Casitas, Raquel; Garcia-Quero, Cristina; Madero, Rosario; Gomez-Rioja, Ruben; Iturzaeta, Jose Manuel

    2015-04-01

    Arterial blood gas analysis is relevant in chronic obstructive pulmonary disease (COPD) management. The aim of this study was to evaluate whether the use of a blood gas analyzer in pulmonology departments improves the clinical, operational and economic outcomes when compared with clinical laboratory measurements. It is an observational prospective study. 112 patients were selected. After specimen collection, the measurement was performed both in pulmonology office as point-of-care and in laboratory. We evaluated clinical outcomes (modification of the indication of long-term oxygen therapy (LTOT) according to results, changes in blood gas analysis results, relationship of the partial pressure of oxygen (PaO2) obtained in the medical visit and velocity of change of the PaO2, influence of total haemoglobin concentration and the change in PaO2), operational outcomes (turnaround time (TAT) from specimen collection to receiving the blood gas analysis report) and economic outcomes (overall cost per process of patient care). There were discrepancies in the indication of LTOT in 13.4% of patients. All parameters showed changes. PaO2 levels showed changes in 2 ways, though they frequently increase over time. The correlation was not good in the other two clinical outcomes. The median TATs in pulmonology office were 1 min versus 79 in laboratory, with 52 min for specimen preparation and transport and 17 min for TAT intralaboratory. The overall cost for the 112 patients in pulmonology office and laboratory was 16,769.89€ and 22,260.97€ respectively. The use of a blood gas analyzer in a pulmonology office improves clinical, operational and economic outcomes when compared with clinical laboratory. Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  1. Generational analysis of trends in unprotected sex in France among men who have sex with men: The major role of context-driven evolving patterns.

    Directory of Open Access Journals (Sweden)

    Nicolas Méthy

    Full Text Available Using a generational approach, this study analyses how unprotected anal intercourse has evolved since 1991 in France across different generations of men who have sex with men (MSM whose sexual lives began at different periods in the history of the HIV epidemic.Data were collected from 18-59 year-old respondents to the French Gay Press surveys Enquêtes Presse Gay, conducted repeatedly between 1991 and 2011 (N = 32,196 using self-administered questionnaires distributed in gay magazines and over the internet.Trends in unprotected anal intercourse (i.e. condomless anal sex with casual partners of unknown or different HIV serostatus (hereafter "UAId" in this manuscript were studied. Responses were analysed according to year and then reorganised for age-cohort analyses by generation, based on the year respondents turned 18.UAId rates fell from 1991 to 1997, and then rose from 13.4% in 1997 to 25.5% in 2011 among seronegative respondents, and from 24.8% to 63.3%, respectively, among seropositive respondents. Both in seropositive and seronegative respondents, UAId increased over time for all generations, indicative of a strong period effect.Analyses of data from several generations of MSM who started their sexual lives at different time points in the HIV epidemic, revealed very similar trends in UAId between generations, among both seropositive and seronegative respondents. This strong period effect suggests that sexual behaviours in MSM are influenced more by contextual than generational factors. The fact that prevention practices are simultaneously observed in different generations and that there are most likely underlying prevention norms among MSM, suggests that PrEP could become widely accepted by all generations of MSM exposed to the risk of HIV.

  2. Generational analysis of trends in unprotected sex in France among men who have sex with men: The major role of context-driven evolving patterns.

    Science.gov (United States)

    Méthy, Nicolas; Meyer, Laurence; Bajos, Nathalie; Velter, Annie

    2017-01-01

    Using a generational approach, this study analyses how unprotected anal intercourse has evolved since 1991 in France across different generations of men who have sex with men (MSM) whose sexual lives began at different periods in the history of the HIV epidemic. Data were collected from 18-59 year-old respondents to the French Gay Press surveys Enquêtes Presse Gay, conducted repeatedly between 1991 and 2011 (N = 32,196) using self-administered questionnaires distributed in gay magazines and over the internet. Trends in unprotected anal intercourse (i.e. condomless anal sex) with casual partners of unknown or different HIV serostatus (hereafter "UAId" in this manuscript) were studied. Responses were analysed according to year and then reorganised for age-cohort analyses by generation, based on the year respondents turned 18. UAId rates fell from 1991 to 1997, and then rose from 13.4% in 1997 to 25.5% in 2011 among seronegative respondents, and from 24.8% to 63.3%, respectively, among seropositive respondents. Both in seropositive and seronegative respondents, UAId increased over time for all generations, indicative of a strong period effect. Analyses of data from several generations of MSM who started their sexual lives at different time points in the HIV epidemic, revealed very similar trends in UAId between generations, among both seropositive and seronegative respondents. This strong period effect suggests that sexual behaviours in MSM are influenced more by contextual than generational factors. The fact that prevention practices are simultaneously observed in different generations and that there are most likely underlying prevention norms among MSM, suggests that PrEP could become widely accepted by all generations of MSM exposed to the risk of HIV.

  3. Wavelength modulation spectroscopy--digital detection of gas absorption harmonics based on Fourier analysis.

    Science.gov (United States)

    Mei, Liang; Svanberg, Sune

    2015-03-20

    This work presents a detailed study of the theoretical aspects of the Fourier analysis method, which has been utilized for gas absorption harmonic detection in wavelength modulation spectroscopy (WMS). The lock-in detection of the harmonic signal is accomplished by studying the phase term of the inverse Fourier transform of the Fourier spectrum that corresponds to the harmonic signal. The mathematics and the corresponding simulation results are given for each procedure when applying the Fourier analysis method. The present work provides a detailed view of the WMS technique when applying the Fourier analysis method.

  4. Exergy costing analysis and performance evaluation of selected gas turbine power plants

    Directory of Open Access Journals (Sweden)

    S.O. Oyedepo

    2015-12-01

    Full Text Available In this study, exergy costing analysis and performance evaluation of selected gas turbine power plants in Nigeria are carried out. The results of exergy analysis confirmed that the combustion chamber is the most exergy destructive component compared to other cycle components. The exergetic efficiency of the plants was found to depend significantly on a change in gas turbine inlet temperature (GTIT. The increase in exergetic efficiency with the increase in turbine inlet temperature is limited by turbine material temperature limit. This was observed from the plant efficiency defect curve. As the turbine inlet temperature increases, the plant efficiency defect decreases to minimum value at certain GTIT (1,200 K, after which it increases with GTIT. This shows degradation in performance of gas turbine plant at high turbine inlet temperature. Exergy costing analysis shows that the combustion chamber has the greatest cost of exergy destruction compared to other components. Increasing the GTIT, both the exergy destruction and the cost of exergy destruction of this component are found to decrease. Also, from exergy costing analysis, the unit cost of electricity produced in the power plants varies from cents 1.99/kWh (N3.16/kWh to cents 5.65/kWh (N8.98/kWh.

  5. Spectrum analysis of national greenhouse gas emission: a case study of Germany

    Energy Technology Data Exchange (ETDEWEB)

    Su, Meirong [Dongguan University of Technology, School of Chemistry and Environmental Engineering, Dongguan, Guangdong Province (China); Beijing Normal University, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Beijing (China); Technical University of Munich, Strategic Landscape Planning and Management, Freising (Germany); Pauleit, Stephan; Xu, Chao [Technical University of Munich, Strategic Landscape Planning and Management, Freising (Germany)

    2016-10-15

    It is essential to abstract the key information from accounting results of greenhouse gas (GHG) emissions because it can provide a highly generalized and clear picture of GHG emissions, which is especially helpful for the public and policy makers. To clearly display the composition of GHG emissions, the concept of spectrum analysis is introduced and defined in this paper. Next, a multilayer analysis framework for national GHG emissions was proposed, which is represented by a pyramid of three layers: total emissions (first layer), emissions decomposed by gas type or sector (second layer), and emissions decomposed by both gas type and sector (third layer). Based on the analysis results from the first to third layers, the main compositional information of national GHG emissions was gradually summarized and analyzed until a spectrum of GHG emissions was acquired. The spectrum of GHG emissions displays the compositional structure of national GHG emissions in the different layers, which is helpful in identifying priorities for emissions reduction. A case study of Germany's GHG emissions during 1990-2012 was conducted, which indicated that CO{sub 2} and the energy sector were the biggest contributors to the total GHG emissions. Some suggestions for reducing GHG emissions are offered based on the obtained results. And the potential development of spectrum analysis for GHG emissions is also expected from aspects of both research and technology. (orig.)

  6. Life Cycle Greenhouse Gas Emissions from Electricity Generation: A Comparative Analysis of Australian Energy Sources

    Directory of Open Access Journals (Sweden)

    Robert G. Hynes

    2012-03-01

    Full Text Available Electricity generation is one of the major contributors to global greenhouse gas emissions. Transitioning the World’s energy economy to a lower carbon future will require significant investment in a variety of cleaner technologies, including renewables and nuclear power. In the short term, improving the efficiency of fossil fuel combustion in energy generation can provide an important contribution. Availability of life cycle GHG intensity data will allow decision-makers to move away from overly simplistic assertions about the relative merits of certain fuels, and focus on the complete picture, especially the critical roles of technology selection and application of best practice. This analysis compares the life-cycle greenhouse gas (GHG intensities per megawatt-hour (MWh of electricity produced for a range of Australian and other energy sources, including coal, conventional liquefied natural gas (LNG, coal seam gas LNG, nuclear and renewables, for the Australian export market. When Australian fossil fuels are exported to China, life cycle greenhouse gas emission intensity in electricity production depends to a significant degree on the technology used in combustion. LNG in general is less GHG intensive than black coal, but the gap is smaller for gas combusted in open cycle gas turbine plant (OCGT and for LNG derived from coal seam gas (CSG. On average, conventional LNG burned in a conventional OCGT plant is approximately 38% less GHG intensive over its life cycle than black coal burned in a sub-critical plant, per MWh of electricity produced. However, if OCGT LNG combustion is compared to the most efficient new ultra-supercritical coal power, the GHG intensity gap narrows considerably. Coal seam gas LNG is approximately 13–20% more GHG intensive across its life cycle, on a like-for like basis, than conventional LNG. Upstream fugitive emissions from CSG (assuming best practice gas extraction techniques do not materially alter the life cycle

  7. An analysis of the types and distribution characteristics of natural gas reservoirs in China

    National Research Council Canada - National Science Library

    Xu Zhangyou Yue Dali Wu Shenghe Zhang Xiaoyu Chen Ce Ni Yuqiang

    2009-01-01

    The natural gas reservoir beds of different areas in China can be divided into three kinds, clastic natural gas reservoir bed, carbonate natural gas reservoir bed and special natural gas reservoir bed...

  8. THE NIGERIAN GAS MASTER-PLAN, INVESTMENT OPPORTUNITIES, CHALLENGES, ISSUES AFFECTING POWER SECTOR: AN ANALYSIS

    Directory of Open Access Journals (Sweden)

    R. INGWE

    2014-11-01

    Full Text Available The Nigerian Gas Master-Plan, Investment Opportunities, Challenges, Issues Affecting Power Sector: an Analysis. The objective of this article is to contribute towards understanding of the Nigerian Gas Master Plan (NGMP/Plan and its bifurcations with key socio-economic development factors. I applied the method of discourse to bring to being some points that have hitherto been unknown about the Master-plan and its inter-relationships and bifurcations. Elaborated here are the spectacular gains that have accrued to the Latin American country, Trinidad and Tobago, from its recent development of natural gas resources. This was considered suitable and significant here for highlighting that if such spectacular achievements could be realized from Trinidad and Tobago’s relatively smaller gas deposit (15.3 tcf, probable reserves (8.4 tcf, possible reserves (6.2 tcf would be by far greater considering Nigeria’s larger natural gas reserves (184 tcf wealth as earlier stated. I show that the Plan is well designed relevant to addressing Nigeria’s current development needs generally. It presents potentials for stimulating Nigeria’s economic growth by harnessing the country’s abundant natural gas reserves. The Plan enumerates/ elaborates huge investment opportunities. Some challenges likely to be faced in the implementation/management of the Plan are already being surmounted as recent reports show that some of its key investments have been realized and the required infrastructure are being provided. Regarding the issues in the Master-plan that are likely to affect and are affecting Nigeria’s power sector development, I reckon that they are mostly positive factors due to the way the plan promises to stimulate electricity generation in our country.

  9. Performance Analysis of Joule-Thomson Cooler Supplied with Gas Mixtures

    Science.gov (United States)

    Piotrowska, A.; Chorowski, M.; Dorosz, P.

    2017-02-01

    Joule-Thomson (J-T) cryo-coolers working in closed cycles and supplied with gas mixtures are the subject of intensive research in different laboratories. The replacement of pure nitrogen by nitrogen-hydrocarbon mixtures allows to improve both thermodynamic parameters and economy of the refrigerators. It is possible to avoid high pressures in the heat exchanger and to use standard refrigeration compressor instead of gas bottles or high-pressure oil free compressor. Closed cycle and mixture filled Joule-Thomson cryogenic refrigerator providing 10-20 W of cooling power at temperature range 90-100 K has been designed and manufactured. Thermodynamic analysis including the optimization of the cryo-cooler mixture has been performed with ASPEN HYSYS software. The paper describes the design of the cryo-cooler and provides thermodynamic analysis of the system. The test results are presented and discussed.

  10. Capacity expansion analysis of UGSs rebuilt from low-permeability fractured gas reservoirs with CO2 as cushion gas

    Directory of Open Access Journals (Sweden)

    Yufei Tan

    2016-11-01

    Full Text Available The techniques of pressurized mining and hydraulic fracturing are often used to improve gas well productivity at the later development stage of low-permeability carbonate gas reservoirs, but reservoirs are watered out and a great number of micro fractures are produced. Therefore, one of the key factors for underground gas storages (UGS rebuilt from low-permeability fractured gas reservoirs with CO2 as the cushion gas is how to expand storage capacity effectively by injecting CO2 to displace water and to develop control strategies for the stable migration of gas–water interface. In this paper, a mathematical model was established to simulate the gas–water flow when CO2 was injected into dual porosity reservoirs to displace water. Then, the gas–water interface migration rules while CO2 was injected in the peripheral gas wells for water displacement were analyzed with one domestic UGS rebuilt from fractured gas reservoirs as the research object. And finally, discussion was made on how CO2 dissolution, bottom hole flowing pressure (BHFP, CO2 injection rate and micro fracture parameters affect the stability of gas–water interface in the process of storage capacity expansion. It is shown that the speed of capacity expansion reaches the maximum value at the fifth cycle and then decreases gradually when UGS capacity is expanded in the pattern of more injection and less withdrawal. Gas–water interface during UGS capacity expansion is made stable due to that the solubility of CO2 in water varies with the reservoir pressure. When the UGS capacity is expanded at constant BHFP and the flow rate, the expansion speed can be increased effectively by increasing the BHFP and the injection flow rate of gas wells in the central areas appropriately. In the reservoir areas with high permeability and fracture-matrix permeability ratio, the injection flow rate should be reduced properly to prevent gas–water interface fingering caused by a high-speed flow

  11. Evolving characteristics and outcome of secondary acute promyelocytic leukemia (APL): A prospective analysis by the French-Belgian-Swiss APL group.

    Science.gov (United States)

    Braun, Thorsten; Cereja, Sophie; Chevret, Sylvie; Raffoux, Emmanuel; Beaumont, Marie; Detourmignies, Laurence; Pigneux, Arnaud; Thomas, Xavier; Bordessoule, Dominique; Guerci, Agnès; Lamy, Thierry; Recher, Christian; Poiré, Xavier; Tournilhac, Olivier; Spertini, Olivier; Chomienne, Christine; Degos, Laurent; Dombret, Hervé; Adès, Lionel; Fenaux, Pierre

    2015-07-15

    Reports of patients with secondary acute promyelocytic leukemia (APL) have increased in recent years, particularly for those who received treatment with mitoxantrone, and retrospective studies have suggested that their characteristics and outcomes were similar to those of patients with de novo APL. The authors investigated patients with de novo and secondary APL who were included in the ongoing APL-2006 trial. Patients with secondary APL who were included in that trial also were compared with a previous retrospective cohort of patients with secondary APL. In the APL-2006 trial, 42 of 280 patients (15%) had secondary APL. Compared with the retrospective cohort, patients with secondary APL in the APL-2006 trial had a lower incidence of prior breast carcinoma (35.7% vs 57%; P = .03) and a higher incidence of prior prostate carcinoma (26.2% vs 4.7%; P < .001). Treatment of the primary tumor in the APL-2006 trial less frequently included combined radiochemotherapy (28.6% vs 47.2%; P = .044) and no mitoxantrone (0% vs 46.7%; P = .016) but more frequently included anthracyclines (53.3% vs 38.3%; P = .015). In the APL-2006 trial, patients who had secondary APL, compared with those who had de novo APL, were older (mean, 60.2 years vs 48.7 years, respectively; P < .0001) but had a similar complete response rate (97.6% vs 90.3%, respectively), cumulative incidence of relapse (0% vs 1.8%, respectively), and overall survival (92.3% vs 90.9%, respectively) at 18 months. Although the incidence of secondary APL appears to be stable over time, evolving strategies for the treatment of primary cancers have reduced its occurrence among breast cancer patients but have increased its incidence among patients with prostate cancer. The current results confirm prospectively that patients with secondary APL have characteristics and outcomes similar to those of patients with de novo APL. © 2015 American Cancer Society.

  12. The use of heparin in preparing samples for blood-gas analysis.

    Science.gov (United States)

    Higgins, Chris

    2007-10-01

    Heparin is the only anticoagulant used to prepare samples for blood-gas analysis. There are two ways in which heparin can interfere with results. The first is high heparin concentration in blood, and the second is heparin dilution of blood if liquid rather than dried (lyophilized) heparin is used. Traditional blood-gas analytes (pH, pCO2, and pO2) are less affected than electrolytes (particularly ionized calcium), also measured on modern blood-gas analyzers. The sample requirements as far as heparin is concerned are thus less exacting if only pH, pCO2, and pO2 are to be measured. For these analytes, it is still essential that the heparin (either sodium or lithium) concentration is less than 200 IU/mL blood and that the blood is not diluted more than 5%. The inclusion of electrolytes in the test repertoire excludes the use of sodium heparin in favor of lithium heparin. The inclusion of ionized calcium in the test repertoire demands that the heparin should be lyophilized, and the concentration should not exceed 10 IU/mL blood, unless a specialized heparin that eliminates the effect of calcium binding by heparin is used. Whatever the heparin formulation, it is essential for accurate results that the correct volume of blood is sampled to achieve a correct heparin concentration (and dilution, if liquid heparin is used), and that blood and anticoagulant are well mixed immediately after sampling. One of the most common practical problems associated with blood-gas analysis is inadequate anticoagulation and the formation of small blood clots that can block the sample pathway of blood-gas analyzers and invalidate results. Inadequate mixing of specimen with heparin is usually the problem. Clearly, the lower the heparin concentration the greater is the risk that poor mixing technique will give rise to inadequate anticoagulation and the associated problems.

  13. A Novel Acoustic Liquid Level Determination Method for Coal Seam Gas Wells Based on Autocorrelation Analysis

    Directory of Open Access Journals (Sweden)

    Ximing Zhang

    2017-11-01

    Full Text Available In coal seam gas (CSG wells, water is periodically removed from the wellbore in order to keep the bottom-hole flowing pressure at low levels, facilitating the desorption of methane gas from the coal bed. In order to calculate gas flow rate and further optimize well performance, it is necessary to accurately monitor the liquid level in real-time. This paper presents a novel method based on autocorrelation function (ACF analysis for determining the liquid level in CSG wells under intense noise conditions. The method involves the calculation of the acoustic travel time in the annulus and processing the autocorrelation signal in order to extract the weak echo under high background noise. In contrast to previous works, the non-linear dependence of the acoustic velocity on temperature and pressure is taken into account. To locate the liquid level of a coal seam gas well the travel time is computed iteratively with the non-linear velocity model. Afterwards, the proposed method is validated using experimental laboratory investigations that have been developed for liquid level detection under two scenarios, representing the combination of low pressure, weak signal, and intense noise generated by gas flowing and leakage. By adopting an evaluation indicator called Crest Factor, the results have shown the superiority of the ACF-based method compared to Fourier filtering (FFT. In the two scenarios, the maximal measurement error from the proposed method was 0.34% and 0.50%, respectively. The latent periodic characteristic of the reflected signal can be extracted by the ACF-based method even when the noise is larger than 1.42 Pa, which is impossible for FFT-based de-noising. A case study focused on a specific CSG well is presented to illustrate the feasibility of the proposed approach, and also to demonstrate that signal processing with autocorrelation analysis can improve the sensitivity of the detection system.

  14. The adaptive internet application for interpretation of the transformer oil gas chromatographic analysis results

    Directory of Open Access Journals (Sweden)

    Polužanski Vladimir

    2015-01-01

    Full Text Available This paper describes an adaptive Internet application for the interpretation of the transformer oil gas chromatographic analysis results. The first version of the application is developed by following an evolutionary software development concept. The most important software development risks and the appropriate solutions are described. An open-source web framework named Bootstrap is used for an application implementation. The application is developed by using ASP.NET and MS SQL server.

  15. Analysis of Volatile Organic Compounds in a Controlled Environment: Ethylene Gas Measurement Studies on Radish

    Science.gov (United States)

    Kong, Suk Bin

    2001-01-01

    Volatile organic compound(VOC), ethylene gas, was characterized and quantified by GC/FID. 20-50 ppb levels were detected during the growth stages of radish. SPME could be a good analytical tool for the purpose. Low temperature trapping method using dry ice/diethyl ether and liquid nitrogen bath was recommended for the sampling process for GC/PID and GC/MS analysis.

  16. Preliminary Failure Modes and Effects Analysis of the US Massive Gas Injection Disruption Mitigation System Design

    Energy Technology Data Exchange (ETDEWEB)

    Cadwallader, Lee C. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2013-10-01

    This report presents the results of a preliminary failure modes and effects analysis (FMEA) of a candidate design for the ITER Disruption Mitigation System. This candidate is the Massive Gas Injection System that provides machine protection in a plasma disruption event. The FMEA was quantified with “generic” component failure rate data as well as some data calculated from operating facilities, and the failure events were ranked for their criticality to system operation.

  17. Method for analysis of heavy sulphur compounds using gas chromatography with flame photometric detection

    OpenAIRE

    Moreira, N.; Pinho, P. Guedes de; Vasconcelos, I

    2004-01-01

    A method for analysis of heavy sulphur compounds in wines, based on gas chromatography (GC) with flame photometric detection, is reported. Wine samples preparation includes a dichloromethane liquid–liquid extraction followed by concentration under a nitrogen atmosphere. The extracted fraction was also analysed by GC–mass spectrometry. The method enables high recovery of sulphur compounds in wine and satisfies the requirements of repeatability and sensitivity. Applications of the meth...

  18. Improved parameterization of interatomic potentials for rare gas dimers with density-based energy decomposition analysis

    Science.gov (United States)

    Zhou, Nengjie; Lu, Zhenyu; Wu, Qin; Zhang, Yingkai

    2014-01-01

    We examine interatomic interactions for rare gas dimers using the density-based energy decomposition analysis (DEDA) in conjunction with computational results from CCSD(T) at the complete basis set (CBS) limit. The unique DEDA capability of separating frozen density interactions from density relaxation contributions is employed to yield clean interaction components, and the results are found to be consistent with the typical physical picture that density relaxations play a very minimal role in rare gas interactions. Equipped with each interaction component as reference, we develop a new three-term molecular mechanical force field to describe rare gas dimers: a smeared charge multipole model for electrostatics with charge penetration effects, a B3LYP-D3 dispersion term for asymptotically correct long-range attractions that is screened at short-range, and a Born-Mayer exponential function for the repulsion. The resulted force field not only reproduces rare gas interaction energies calculated at the CCSD(T)/CBS level, but also yields each interaction component (electrostatic or van der Waals) which agrees very well with its corresponding reference value. PMID:24908000

  19. Mixed Finite Element Simulation with Stability Analysis for Gas Transport in Low-Permeability Reservoirs

    Directory of Open Access Journals (Sweden)

    Mohamed F. El-Amin

    2018-01-01

    Full Text Available Natural gas exists in considerable quantities in tight reservoirs. Tight formations are rocks with very tiny or poorly connected pors that make flow through them very difficult, i.e., the permeability is very low. The mixed finite element method (MFEM, which is locally conservative, is suitable to simulate the flow in porous media. This paper is devoted to developing a mixed finite element (MFE technique to simulate the gas transport in low permeability reservoirs. The mathematical model, which describes gas transport in low permeability formations, contains slippage effect, as well as adsorption and diffusion mechanisms. The apparent permeability is employed to represent the slippage effect in low-permeability formations. The gas adsorption on the pore surface has been described by Langmuir isotherm model, while the Peng-Robinson equation of state is used in the thermodynamic calculations. Important compatibility conditions must hold to guarantee the stability of the mixed method by adding additional constraints to the numerical discretization. The stability conditions of the MFE scheme has been provided. A theorem and three lemmas on the stability analysis of the mixed finite element method (MFEM have been established and proven. A semi-implicit scheme is developed to solve the governing equations. Numerical experiments are carried out under various values of the physical parameters.

  20. Implementation of an ultrasonic instrument for simultaneous mixture and flow analysis of binary gas systems

    Energy Technology Data Exchange (ETDEWEB)

    Alhroob, M.; Boyd, G.; Hasib, A.; Pearson, B.; Srauss, M.; Young, J. [Department of Physics and Astronomy, University of Oklahoma, Norman, OK 73019, (United States); Bates, R.; Bitadze, A. [School of Physics and Astronomy, University of Glasgow, G12 8QQ, (United Kingdom); Battistin, M.; Berry, S.; Bonneau, P.; Botelho-Direito, J.; Bozza, G.; Crespo-Lopez, O.; DiGirolamo, B.; Favre, G.; Godlewski, J.; Lombard, D.; Zwalinski, L. [CERN, 1211 Geneva 23, (Switzerland); Bousson, N.; Hallewell, G.; Mathieu, M.; Rozanov, A. [Centre de Physique des Particules de Marseille, 163 Avenue de Luminy, 13288 Marseille Cedex 09, (France); Deterre, C.; O' Rourke, A. [Deutsches Elektronen-Synchrotron, Notkestrasse 85, D-22607 Hamburg, (Germany); Doubek, M.; Vacek, V. [Czech Technical University, Technick 4, 166 07 Prague 6, (Czech Republic); Degeorge, C. [Physics Department, Indiana University, Bloomington, IN 47405, (United States); Katunin, S. [B.P. Konstantinov Petersburg Nuclear Physics Institute (PNPI), 188300 St. Petersburg, (Russian Federation); Langevin, N. [Institut Universitaire de Technologie of Marseille, University of Aix-Marseille, 142 Traverse Charles Susini, 13013 Marseille, (France); McMahon, S. [Rutherford Appleton Laboratory - Science and Technology Facilities Council, Harwell Science and Innovation Campus, Didcot OX11 OQX, (United Kingdom); Nagai, K. [Department of Physics, Oxford University, Oxford OX1 3RH, (United Kingdom); Robinson, D. [Department of Physics and Astronomy, University of Cambridge, (United Kingdom); Rossi, C. [INFN - Genova, Via Dodecaneso 33, 16146 Genova, (Italy)

    2015-07-01

    Precision ultrasonic measurements in binary gas systems provide continuous real-time monitoring of mixture composition and flow. Using custom micro-controller-based electronics, we have developed an ultrasonic instrument, with numerous potential applications, capable of making continuous high-precision sound velocity measurements. The instrument measures sound transit times along two opposite directions aligned parallel to - or obliquely crossing - the gas flow. The difference between the two measured times yields the gas flow rate while their average gives the sound velocity, which can be compared with a sound velocity vs. molar composition look-up table for the binary mixture at a given temperature and pressure. The look-up table may be generated from prior measurements in known mixtures of the two components, from theoretical calculations, or from a combination of the two. We describe the instrument and its performance within numerous applications in the ATLAS experiment at the CERN Large Hadron Collider (LHC). The instrument can be of interest in other areas where continuous in-situ binary gas analysis and flowmetry are required. (authors)

  1. The impact of introducing universal umbilical cord blood gas analysis and lactate measurement at delivery.

    Science.gov (United States)

    White, Christopher R H; Doherty, Dorota A; Newnham, John P; Pennell, Craig E

    2014-02-01

    There is growing support for umbilical cord blood gas analysis (UCBGA) to be conducted at delivery. A recent study in a tertiary level obstetric unit found that universal UCBGA was associated with improved perinatal outcomes, but there is less evidence of benefit in lower-risk environments. In such settings, lactate analysis may be a suitable alternative. This study evaluated the introduction of universal UCBGA into a secondary obstetric unit and universal umbilical cord lactate analysis program into primary and secondary units. After education, universal UCBGA or lactate analysis was introduced into one primary and two secondary level obstetric units. Univariate and adjusted analysis assessed changes in UCBGA values and Apgar scores over the study period. There were no significant changes in mean blood gas and lactate values at any centre following introduction of universal UCBGA or lactate analysis. However, there was at the primary level obstetric unit a significant reduction in the proportion of neonates with moderate to severe elevations in umbilical artery lactate values. There was a non-significant reduction in arterial pH values less than 7.10 at the secondary metropolitan centre. The data presented in this study suggest that the benefits of introducing UCBGA into a tertiary obstetric centre may be reproduced in a primary obstetric centre within 12 months of implementation. Larger studies are required in secondary units to assess infrequent adverse obstetric and neonatal outcomes. © 2013 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists.

  2. ANALYSIS AND IDENTIFICATION SPIKING CHEMICAL COMPOUNDS RELATED TO CHEMICAL WEAPON CONVENTION IN UNKNOWN WATER SAMPLES USING GAS CHROMATOGRAPHY AND GAS CHROMATOGRAPHY ELECTRON IONIZATION MASS SPECTROMETRY

    Directory of Open Access Journals (Sweden)

    Harry Budiman

    2010-06-01

    Full Text Available The identification and analysis of chemical warfare agents and their degradation products is one of important component for the implementation of the convention. Nowadays, the analytical method for determination chemical warfare agent and their degradation products has been developing and improving. In order to get the sufficient analytical data as recommended by OPCW especially in Proficiency Testing, the spiking chemical compounds related to Chemical Weapon Convention in unknown water sample were determined using two different techniques such as gas chromatography and gas chromatography electron-impact ionization mass spectrometry. Neutral organic extraction, pH 11 organic extraction, cation exchanged-methylation, triethylamine/methanol-silylation were performed to extract the chemical warfare agents from the sample, before analyzing with gas chromatography. The identification of chemical warfare agents was carried out by comparing the mass spectrum of chemicals with mass spectrum reference from the OPCW Central Analytical Database (OCAD library while the retention indices calculation obtained from gas chromatography analysis was used to get the confirmation and supported data of  the chemical warfare agents. Diisopropyl methylphosphonate, 2,2-diphenyl-2-hydroacetic acid and 3-quinuclidinol were found in unknown water sample. Those chemicals were classified in schedule 2 as precursor or reactant of chemical weapons compound in schedule list of Chemical Weapon Convention.   Keywords: gas chromatography, mass spectrometry, retention indices, OCAD library, chemical warfare agents

  3. Use of hydrogen as a carrier gas for the analysis of steroids with anabolic activity by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Muñoz-Guerra, J A; Prado, P; García-Tenorio, S Vargas

    2011-10-14

    Due to the impact in the media and the requirements of sensitivity and robustness, the detection of the misuse of forbidden substances in sports is a really challenging area for analytical chemistry, where any study focused on enhancing the performance of the analytical methods will be of great interest. The aim of the present study was to evaluate the usefulness of using hydrogen instead of helium as a carrier gas for the analysis of anabolic steroids by gas chromatography-mass spectrometry with electron ionization. There are several drawbacks related with the use of helium as a carrier gas: it is expensive, is a non-renewable resource, and has limited availability in many parts of the world. In contrast, hydrogen is readily available using a hydrogen generator or high-pressure bottled gas, and allows a faster analysis without loss of efficiency; nevertheless it should not be forgotten that due to its explosiveness hydrogen must be handled with caution. Throughout the study the impact of the change of the carrier gas will be evaluated in terms of: performance of the chromatographic system, saving of time and money, impact on the high vacuum in the analyzer, changes in the fragmentation behaviour of the analytes, and finally consequences for the limits of detection achieved with the method. Copyright © 2011 Elsevier B.V. All rights reserved.

  4. Comprehensive two-dimensional gas chromatography for biogas and biomethane analysis.

    Science.gov (United States)

    Hilaire, F; Basset, E; Bayard, R; Gallardo, M; Thiebaut, D; Vial, J

    2017-11-17

    The gas industry is going to be revolutionized by being able to generate bioenergy from biomass. The production of biomethane - a green substitute of natural gas - is growing in Europe and the United-States of America. Biomethane can be injected into the gas grid or used as fuel for vehicles after compression. Due to various biomass inputs (e.g. agricultural wastes, sludges from sewage treatment plants, etc.), production processes (e.g. anaerobic digestion, municipal solid waste (MSW) landfills), seasonal effects and purification processes (e.g. gas scrubbers, pressure swing adsorption, membranes for biogas upgrading), the composition and quality of biogas and biomethane produced is difficult to assess. All previous publications dealing with biogas analysis reported that hundreds of chemicals from ten chemical families do exist in trace amounts in biogas. However, to the best of our knowledge, no study reported a detailed analysis or the implementation of comprehensive two-dimensional gas chromatography (GC×GC) for biogas matrices. This is the reason why the benefit of implementing two-dimensional gas chromatography for the characterization of biogas and biomethane samples was evaluated. In a first step, a standard mixture of 89 compounds belonging to 10 chemical families, representative of those likely to be found, was used to optimize the analytical method. A set consisting of a non-polar and a polar columns, respectively in the first and the second dimension, was used with a modulation period of six seconds. Applied to ten samples of raw biogas, treated biogas and biomethane collected on 4 industrial sites (two MSW landfills, one anaerobic digester on a wastewater treatment plant and one agricultural biogas plant), this analytical method provided a "fingerprint" of the gases composition at the molecular level in all biogas and biomethane samples. Estimated limits of detection (far below the μgNm -3 ) coupled with the resolution of GC×GC allowed the comparison

  5. Ozonolysis of α/β-farnesene mixture: Analysis of gas-phase and particulate reaction products

    Science.gov (United States)

    Jaoui, Mohammed; Lewandowski, Michael; Offenberg, John H.; Docherty, Kenneth S.; Kleindienst, Tadeusz E.

    2017-11-01

    Atmospheric oxidation of sesquiterpenes has been of considerable interest recently because of their likely contribution to ambient organic aerosol, but farnesene oxidation has been reported in only a few studies and with limited data. In the present study, a detailed chemical analysis of the organic fraction of gas and particle phases originating from the ozonolysis of a mixture of α-farnesene and β-farnesene was carried out in a 14.5 m3 smog chamber. More than 80 organic compounds bearing OH functionality were detected for the first time in this system in the gas and particle phases. The major secondary organic aerosol (SOA) components included conjugated α-farnesene trienols, hydroxyl carboxylic acid and its corresponding lactones, C3-C7 linear dicarboxylic acids, and hydroxy/carbonyl/carboxylic compounds. Of particular importance was 5,6-dihydroxy-6-methylheptan-2-one (DHMHO), which was detected at high concentration. In the gas phase, the main species identified were trienols and their corresponding epoxides and diepoxides. Proposed reaction schemes are provided for selected compounds. A similar analysis was performed for ambient PM2.5 samples collected during summer 2013 as part of the SOAS to determine farnesene contributions to PM2.5. Gas chromatography-mass spectrometry analysis were consistent with the occurrence of several farnesene SOA compounds, indicating the potential impact of farnesene on the regional aerosol burden. The high abundance of DHMHO in chamber SOA and its presence in ambient PM2.5 is particularly important because to our knowledge it is specific to farnesene and therefore could serve as an indicator for farnesene emitted into ambient aerosol. In the absence of authentic standards, however, it is difficult to accurately quantify the contribution of SOA originating from farnesene to ambient PM2.5.

  6. Chemical derivatization of pharmaceutical samples prior to Gas-Chromatography and Mass-Spectrometry analysis

    Directory of Open Access Journals (Sweden)

    Vivek K. Bajpai

    2016-12-01

    Full Text Available Derivatization is the process by which a compound is chemically changed, that has properties more amenable to a particular analytical method. Some samples analyzed by Gas-chromatography and Mass-spectrometry (GC-MS require derivatization in order to make them suitable for analysis. Especially the compounds that have poor volatility, poor thermal stability, or that can be adsorbed in the injector will exhibit non-reproducible peak areas, heights, and shapes. Hence, this study focused on step-by-step visual demonstration of chemical derivatization of pharmaceutical samples prior to GC-MS analysis for their better elution and detection.

  7. Evaluation of three gas chromatography and two direct mass spectrometry techniques for aroma analysis of dried red bell peppers

    NARCIS (Netherlands)

    Ruth, van S.M.; Boscaini, E.; Mayr, D.; Pugh, J.; Posthumus, M.A.

    2003-01-01

    Three gas chromatography methods and two direct mass spectrometry techniques were compared for the analysis of the aroma of rehydrated diced red bell peppers. Gas chromatography methods included systems with olfactometry detection (GC-O), flame ionisation detection (GC-FID) and mass spectrometry

  8. Sensitivity Analysis of Methane Hydrate Reservoirs: Effects of Reservoir Parameters on Gas Productivity and Economics

    Science.gov (United States)

    Anderson, B. J.; Gaddipati, M.; Nyayapathi, L.

    2008-12-01

    This paper presents a parametric study on production rates of natural gas from gas hydrates by the method of depressurization, using CMG STARS. Seven factors/parameters were considered as perturbations from a base-case hydrate reservoir description based on Problem 7 of the International Methane Hydrate Reservoir Simulator Code Comparison Study led by the Department of Energy and the USGS. This reservoir is modeled after the inferred properties of the hydrate deposit at the Prudhoe Bay L-106 site. The included sensitivity variables were hydrate saturation, pressure (depth), temperature, bottom-hole pressure of the production well, free water saturation, intrinsic rock permeability, and porosity. A two-level (L=2) Plackett-Burman experimental design was used to study the relative effects of these factors. The measured variable was the discounted cumulative gas production. The discount rate chosen was 15%, resulting in the gas contribution to the net present value of a reservoir. Eight different designs were developed for conducting sensitivity analysis and the effects of the parameters on the real and discounted production rates will be discussed. The breakeven price in various cases and the dependence of the breakeven price on the production parameters is given in the paper. As expected, initial reservoir temperature has the strongest positive effect on the productivity of a hydrate deposit and the bottom-hole pressure in the production well has the strongest negative dependence. Also resulting in a positive correlation is the intrinsic permeability and the initial free water of the formation. Negative effects were found for initial hydrate saturation (at saturations greater than 50% of the pore space) and the reservoir porosity. These negative effects are related to the available sensible heat of the reservoir, with decreasing productivity due to decreasing available sensible heat. Finally, we conclude that for the base case reservoir, the break-even price (BEP

  9. Multi channel thermal hydraulic analysis of gas cooled fast reactor using genetic algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Drajat, R. Z.; Su' ud, Z.; Soewono, E.; Gunawan, A. Y. [Department of Mathematics, Institut Teknologi Bandung, Bandung 40132 (Indonesia); Department of Physics, Institut Teknologi Bandung, Bandung 40132 (Indonesia); Department of Mathematics, Institut Teknologi Bandung, Bandung 40132 (Indonesia)

    2012-05-22

    There are three analyzes to be done in the design process of nuclear reactor i.e. neutronic analysis, thermal hydraulic analysis and thermodynamic analysis. The focus in this article is the thermal hydraulic analysis, which has a very important role in terms of system efficiency and the selection of the optimal design. This analysis is performed in a type of Gas Cooled Fast Reactor (GFR) using cooling Helium (He). The heat from nuclear fission reactions in nuclear reactors will be distributed through the process of conduction in fuel elements. Furthermore, the heat is delivered through a process of heat convection in the fluid flow in cooling channel. Temperature changes that occur in the coolant channels cause a decrease in pressure at the top of the reactor core. The governing equations in each channel consist of mass balance, momentum balance, energy balance, mass conservation and ideal gas equation. The problem is reduced to finding flow rates in each channel such that the pressure drops at the top of the reactor core are all equal. The problem is solved numerically with the genetic algorithm method. Flow rates and temperature distribution in each channel are obtained here.

  10. Propagation of uncertainty and sensitivity analysis in an integral oil-gas plume model

    KAUST Repository

    Wang, Shitao

    2016-05-27

    Polynomial Chaos expansions are used to analyze uncertainties in an integral oil-gas plume model simulating the Deepwater Horizon oil spill. The study focuses on six uncertain input parameters—two entrainment parameters, the gas to oil ratio, two parameters associated with the droplet-size distribution, and the flow rate—that impact the model\\'s estimates of the plume\\'s trap and peel heights, and of its various gas fluxes. The ranges of the uncertain inputs were determined by experimental data. Ensemble calculations were performed to construct polynomial chaos-based surrogates that describe the variations in the outputs due to variations in the uncertain inputs. The surrogates were then used to estimate reliably the statistics of the model outputs, and to perform an analysis of variance. Two experiments were performed to study the impacts of high and low flow rate uncertainties. The analysis shows that in the former case the flow rate is the largest contributor to output uncertainties, whereas in the latter case, with the uncertainty range constrained by aposteriori analyses, the flow rate\\'s contribution becomes negligible. The trap and peel heights uncertainties are then mainly due to uncertainties in the 95% percentile of the droplet size and in the entrainment parameters.

  11. Can venous blood gas analysis be used for predicting seizure recurrence in emergency department?

    Science.gov (United States)

    Kılıc, Turgay Yılmaz; Yesilaras, Murat; Atilla, Ozge Duman; Sever, Mustafa; Aksay, Ersin

    2014-01-01

    Epileptic seizures account for 1%-2% of all admissions of patients to the emergency department (ED). The present study aimed to determine whether venous blood pH, bicarbonate, base excess, and lactate levels taken within 1 hour of the last seizure episode help to determine seizure recurrence in emergency departments. A cross-sectional study was conducted in the emergency department (ED) between January and July, 2012. Patients who were admitted to the emergency department consecutively were included in the study if they were 14 years or older and within 1 hour after last seizure. Demographics, seizure type, use of antiepileptic drugs, observation period at the emergency department, seizure recurrence, pH, bicarbonate, base excess, and lactate levels from venous blood gas analysis were determined. A total of 94 patients aged 14 years or older were included in the study. Of these patients, 10.6% (n=10) experienced recurrent seizures in the observation period at the emergency department. To predict recurrent seizures in ED, threshold venous blood gas values were determined as follows: pH7.65 mmol/L [sensitivity 80% (95%CI: 44-96), negative predictive value 96.6% (95%CI: 87-99)]. If venous blood gas analysis is made on pH, base excess, lactate and bicarbonate immediately one hour after the last epileptic seizure episode, it is possible to predict whether the patient will have seizure recurrence.

  12. Exergy analysis in the assessment of the sustainability of waste gas treatment systems.

    Science.gov (United States)

    Dewulf, J; Van Langenhove, H; Dirckx, J

    2001-06-12

    This study focuses on the sustainability of different technological options for the treatment of waste gases from a waste water treatment plant loaded with volatile organic compounds. The options considered are biofiltration, active carbon adsorption and catalytic and thermal oxidation. The amount of resources and utilities to construct and operate each system have been investigated from the point of view of the Second Law of thermodynamics. The unit in which all resources are treated is Joules of exergy. It was concluded that biofiltration was the most exergetically efficient system. The cumulative exergy consumption of the resources and utilities for construction and operation have been quantified in exergy terms. Further on, the requirements for the abatement of emissions generated by operating the waste gas treatment systems and the amount of renewables have been taken into account in the assessment of the sustainability of the waste gas treatment technologies. Finally, a comparison between exergy analysis and life cycle analysis in assessing the sustainability of the waste gas treatment options, is presented.

  13. Optimal q-homotopy analysis method for time-space fractional gas dynamics equation

    Science.gov (United States)

    Saad, K. M.; AL-Shareef, E. H.; Mohamed, Mohamed S.; Yang, Xiao-Jun

    2017-01-01

    It is well known that the homotopy analysis method is one of the most efficient methods for obtaining analytical or approximate semi-analytical solutions of both linear and non-linear partial differential equations. A more general form of HAM is introduced in this paper, which is called Optimal q-Homotopy Analysis Method (Oq-HAM). It has better convergence properties as compared with the usual HAM, due to the presence of fraction factor associated with the solution. The convergence of q-HAM is studied in details elsewhere (M.A. El-Tawil, Int. J. Contemp. Math. Sci. 8, 481 (2013)). Oq-HAM is applied to the non-linear homogeneous and non-homogeneous time and space fractional gas dynamics equations with initial condition. An optimal convergence region is determined through the residual error. By minimizing the square residual error, the optimal convergence control parameters can be obtained. The accuracy and efficiency of the proposed method are verified by comparison with the exact solution of the fractional gas dynamics equation. Also, it is shown that the Oq-HAM for the fractional gas dynamics equation is equivalent to the exact solution. We obtain graphical representations of the solutions using MATHEMATICA.

  14. An Alternative to Performing Remote-Handled Transuranic Waste Container Headspace Gas Sampling and Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Spangler, L. R.; Djordjevic, S. M.; Kehrman, R. F.; Most, W. A.

    2002-02-26

    The Waste Isolation Pilot Plant (WIPP) is operating under a Resource Conservation and Recovery Act (RCRA) Hazardous Waste Facility Permit (HWFP) for contact-handled (CH) transuranic (TRU) waste. The HWFP contains limitations on allowable emissions from waste disposed in the underground. This environmental performance standard imposed on the WIPP consists of limiting volatile organic compound (VOC) emissions from emplaced waste to ensure protection of human health and the environment. The standard is currently met by tracking individual waste container headspace gas concentrations, which are determined by headspace gas sampling and analysis of CH TRU waste containers. The WIPP is seeking a HWFP modification to allow the disposal of remote-handled (RH) TRU waste. Because RH TRU waste is limited to approximately 5% of the waste volume and is emplaced in the disposal room walls, it is possible to bound the potential RH TRU waste contribution to VOC emissions using conservative upper bounds. These conservative upper bounds were developed as an alternative to RH TRU waste canister headspace gas sampling and analysis. The methodology used to perform the calculations used to evaluate VOC emissions from emplaced RH TRU waste canisters applied the same equations as those used to evaluate VOC emissions in the original HWFP application.

  15. Report - Analysis of designer drugs in human blood using gas chromatography-mass spectrometry.

    Science.gov (United States)

    Chen, Xueguo; Zhao, Dan

    2017-05-01

    A robust gas chromatography-mass spectrometry method was utilized in the qualitative and quantitative analysis of designer drugs in human blood. Designer drugs, including methcathinone, 3, 4-methylenedioxymethcathinone, 4'-methyl-α-pyrrolidinopropiophenone and methylenedioxy-pyrovalerone were simultaneously analyzed by gas chromatography-mass spectrometry. Liquid-liquid small volume extraction was employed in the pretreatment of human blood sample, and the experimental results showed that the method was validated with high extraction efficiency, low limits of detection and good linearity throughout the studied concentration ranges. Furthermore, the method not only exhibited good accuracy and precision in the determination of designer drugs in human blood, but also showed the potential of the approach in the determination of trace evidence in forensic science.

  16. Analysis of whole blood samples with low gas flow inductively coupled plasma-optical emission spectrometry.

    Science.gov (United States)

    Nowak, Sascha; Künnemeyer, Jens; Terborg, Lydia; Trümpler, Stefan; Günsel, Andreas; Wiesmüller, Gerhard A; Karst, Uwe; Buscher, Wolfgang

    2015-01-01

    Low gas flow ICP-OES with a total argon consumption below 0.7 L/min is introduced for the analysis of trace elements in blood samples to investigate the influence of samples containing an organic solvent in a demanding matrix on the performance of this plasma for the first time. Therefore, gadolinium was determined in human plasma samples and mercury in red blood cells, human plasma, and precipitated plasma protein fraction. Limits of detection (LOD) were determined to be in the low microgram per liter range for the analytes and the accuracy of the method was assessed by comparison with a conventional Fassel-type torch-based ICP-OES. It was proven that the low gas flow ICP-OES leads to comparable results with the instrument based on the Fassel-type torch.

  17. An analysis of seasonality fluctuations in the oil and gas stock returns

    Directory of Open Access Journals (Sweden)

    Muhammad Surajo Sanusi

    2016-12-01

    Full Text Available This paper investigates the existence of seasonality anomalies in the stock returns of the oil and gas companies on the London Stock Exchange. It employs F-test, Kruskal–Wallis and Tukey tests to examine days-of-the-week effect. Generalised autoregressive conditional heteroscedasticity specification was also employed to investigate both the days-of-the-week and months-of-the-year effects. The analysis had been extended to some key FTSE indices. Our results showed no evidence of any regularity or seasonal fluctuation in the oil and gas stock returns despite the seasonal changes of demand in the companies’ products. However, January effect has been observed in FTSE All Share and FTSE 100 indices.

  18. Decision analysis for the exploration of gas reserves: merging todim and thor

    Directory of Open Access Journals (Sweden)

    Carlos Francisco Simões Gomes

    2010-12-01

    Full Text Available This article approaches the problem of selecting the non-dominated alternative for the destination of the natural gas reserves in the Mexilhão field in the Santos Basin, Brazil. Major aims of the case study reported here were to create a mechanism for assisting in the process of analyzing and selecting the best options for the destination of natural gas, and to enable the decision agent to choose the investment options best aligned to the expectations and objectives observed in the company strategies. The decision analysis employed in the study made use of the TODIM method and the THOR multicriteria decision support system. The application of both demonstrated that a decision analytic framework can be extremely useful when recommending options for upstream projects, owing to the fact that it can clearly identify the most important alternatives in the face of the scenarios tested and in relation to the criteria expressed.

  19. Performance Analysis of Gas Foil Bearing with Different Foil Pivot Configuration

    Directory of Open Access Journals (Sweden)

    Milind Babasaheb Patil

    2013-01-01

    Full Text Available A numerical model is developed in order to find out the performance characteristics of gas foil bearings. The static performance analysis of gas foil bearings has been carried out using an elastic foundation model of the foil. The steady state results have been compared with the experimental and theoretical results available in the literature. The characteristics of the bearing have been investigated with change in foil pivot position. It has been shown that the load carrying capacity is different for different foil pivot positions. Besides effect of bearing parameters like eccentricity ratio, length to diameter ratio, compliance coefficient, and bearing number on the load carrying capacity with different foil pivot positions have been studied.

  20. Interpretation of blood gas analysis by physicians in a community teaching hospital.

    Science.gov (United States)

    Powles, A C; Morse, J L; Pugsley, S O; Campbell, E J

    1979-07-01

    Forty-two interns and residents on the staff of a community teaching hospital were questioned to assess their understanding of blood gas abnormalities. Misunderstandings were such that 24% of the residents and interns might have given inadequate care had their interpretations dictated practice. Few therapeutic misadventures in fact occurred, largely because of supervision. Even without supervision, it is unlikely that much harm would have come about, partly because pattern recognition and rules of thumb provided adequate guidance and partly because no notice was taken of the results of the blood gas analysis anyway. Those who wish to promote rational practice should direct their educational efforts to improved understanding of the mechanisms of hypoxaemia and of the chemical, physiological and pathophysiological interactions of PCO2, bicarbonate and pH in the various acid-base disorders.

  1. Signal analysis of voltage noise in welding arcs. [gas tungsten arc welding

    Science.gov (United States)

    Elis, E.; Eagar, T. W.

    1982-01-01

    Gas tungsten arc welds were made on low alloy steel plates to which intentional defects (discontinuities) were imposed. Disruption of shielding gas, welding over surface films, and tack welds produce changes in what is otherwise a relatively uniform voltage signal. The arc voltage was 15 volts + or - 2 volts with 300 mV ripple noise from the power supply. Changes in this steady noise voltage varied from 50 mV to less than one millivolt depending on the severity and the type of change experienced. In some instances the changes were easily detected by analysis of the signal in real time, while in other cases the signal had to transformed to the frequency domain in order to detect the changes. Discontinuities as small as 1.5 mm in length were detected. The ultimate sensitivity and reproducibility of the technique is still being investigated.

  2. Analysis of the Cold Gas Flow in Puffer Type Circuit Breaker

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hong Kyu; Jung, Hyun Kyo [Seoul National University (Korea); Shin, Seong Rok [Samsung SDI R and D Center (Korea); Kim, Doo Sung; Kweon, KI Yeoung [Hyosung Heavy Industry (Korea)

    2000-04-01

    There are many difficult problems in analyzing the gas flow in puffer type circuit breaker such as complex geometry, moving boundary, shock wave and so on. To predict the interruption performance accurately, these should be considered in the simulation. In this paper, the analysis procedure of the cold gas flow in the circuit breaker is presented. Euler equation is solved by FVFLIC method which is an explicit time difference scheme for an unsteady flow computation. Moving boundaries are treated with a cell elimination-addition technique. The pressure and density in front of piston are calculated from the rate of the cell volume change. The presented method is applied to the real circuit breaker model and the pressure in front of the piston is good agreement with the experimental one. (author). 8 refs., 13 figs., 1 tab.

  3. Energy Sensitivity analysis and greenhouse gas emissions for tea production in Guilan Province

    Directory of Open Access Journals (Sweden)

    Amin Nikkhah

    2016-05-01

    Full Text Available Sustainable development of the production in every region requires consideration of energy flow in the production system, moreover, investigating the production system inputs from environmental management point of view is of high importance. In this study energy use and greenhouse gas emissions is investigated. Data were collected through interviews with 75 tea farmers and comparing the results with Farmers Information Book. Total energy input was 39060.60 MJ ha-1. Energy efficiency was calculated as 0.22. Chemical fertilizers had the largest share in energy use and greenhouse gas emissions with 58.55% and 74.22% in tea production respectively. Total greenhouse gas emission in tea production was 1281.82 kgCO2eq. ha-1. The Results of Cobb-Douglas model and sensitivity analysis of energy inputs revealed that the effect of all energy inputs except chemicals were positive on the yield, and the Input of human labor energy on yield was significant at the level of one percent. Energy of labor input had the most sensitivity and also had the most effect on the yield and then the machinery energy input and chemicals had the next highest effect on the yield of tea production in Guilan province Sustainable development of the production in every region requires consideration of energy flow in the production system, moreover, investigating the production system inputs from environmental management point of view is of high importance. In this study energy use and greenhouse gas emissions is investigated. Data were collected through interviews with 75 tea farmers and comparing the results with Farmers Information Book. Total energy input was 39060.60 MJ ha-1. Energy efficiency was calculated as 0.22. Chemical fertilizers had the largest share in energy use and greenhouse gas emissions with 58.55% and 74.22% in tea production respectively. Total greenhouse gas emission in tea production was 1281.82 kgCO2eq. ha-1. The Results of Cobb-Douglas model and sensitivity

  4. Risk Analysis of Return Support Material on Gas Compressor Platform Project

    Science.gov (United States)

    Silvianita; Aulia, B. U.; Khakim, M. L. N.; Rosyid, Daniel M.

    2017-07-01

    On a fixed platforms project are not only carried out by a contractor, but two or more contractors. Cooperation in the construction of fixed platforms is often not according to plan, it is caused by several factors. It takes a good synergy between the contractor to avoid miss communication may cause problems on the project. For the example is about support material (sea fastening, skid shoe and shipping support) used in the process of sending a jacket structure to operation place often does not return to the contractor. It needs a systematic method to overcome the problem of support material. This paper analyses the causes and effects of GAS Compressor Platform that support material is not return, using Fault Tree Analysis (FTA) and Event Tree Analysis (ETA). From fault tree analysis, the probability of top event is 0.7783. From event tree analysis diagram, the contractors lose Rp.350.000.000, - to Rp.10.000.000.000, -.

  5. Dynamic analysis of a liquid droplet and optimization of helical angles for vortex drainage gas recovery

    Directory of Open Access Journals (Sweden)

    Xiaodong Wu

    2016-10-01

    Full Text Available Downhole vortex drainage gas recovery is a new gas production technology. So far, however, the forces and motions of liquid phase in the swirling flow field of wellbores during its field application have not been figured out. In this paper, the forces of liquid droplets in the swirling flow field of wellbores were analyzed on the basis of two-phase fluid dynamics theories. Then, the motion equations of fluid droplets along axial and radical directions were established. Magnitude comparison was performed on several typical acting forces, including Basset force, virtual mass force, Magnus force, Saffman force and Stokes force. Besides, the formula for calculating the optimal helical angle of vortex tools was established according to the principle that the vertical resultant force on fluid droplets should be the maximum. And afterwards, each acting force was comprehensively analyzed in terms of its origin, characteristics and direction based on the established force analysis model. Magnitude comparison indicates that the forces with less effect can be neglected, including virtual mass force, Basset force and convection volume force. Moreover, the vertically upward centrifugal force component occurs on the fluid droplets in swirling flow field instead of those in the conventional flow field of wellbores, which is favorable for the fluid droplets to move upward. The reliability of optimal helical angle calculation formula was verified by means of case analysis. It is demonstrated that with the decrease of well depth, the fluid-carrying capability of gas and the optimal helical angle increase. The research results in this paper have a guiding significance to the optimization design of downhole vortex tools and the field application of downhole vortex drainage gas recovery technology.

  6. Spatial Risk Analysis of Hydraulic Fracturing near Abandoned and Converted Oil and Gas Wells.

    Science.gov (United States)

    Brownlow, Joshua W; Yelderman, Joe C; James, Scott C

    2017-03-01

    Interaction between hydraulically generated fractures and existing wells (frac hits) could represent a potential risk to groundwater. In particular, frac hits on abandoned oil and gas wells could lead to upward leakage into overlying aquifers, provided migration pathways are present along the abandoned well. However, potential risk to groundwater is relatively unknown because few studies have investigated the probability of frac hits on abandoned wells. In this study, actual numbers of frac hits were not determined. Rather, the probability for abandoned wells to intersect hypothetical stimulated reservoir sizes of horizontal wells was investigated. Well data were compiled and analyzed for location and reservoir information, and sensitivity analyses were conducted by varying assumed sizes of stimulated reservoirs. This study used public and industry data for the Eagle Ford Shale play in south Texas, with specific attention paid to abandoned oil and gas wells converted into water wells (converted wells). In counties with Eagle Ford Shale activity, well-data analysis identified 55,720 abandoned wells with a median age of 1983, and 2400 converted wells with a median age of 1954. The most aggressive scenario resulted in 823 abandoned wells and 184 converted wells intersecting the largest assumed stimulated reservoir size. Analysis showed abandoned wells have the potential to be intersected by multiple stimulated reservoirs, and risks for intersection would increase if currently permitted horizontal wells in the Eagle Ford Shale are actually completed. Results underscore the need to evaluate historical oil and gas activities in areas with modern unconventional oil and gas activities. © 2016, National Ground Water Association.

  7. Agricultural green gas demonstration projects in the Netherlands. A stakeholder analysis

    NARCIS (Netherlands)

    Hoppe, Thomas; Sanders, Maurits

    2014-01-01

    In the Netherlands green gas is seen as a sustainable alternative to natural gas. However, green gas is still not competitive to natural gas in terms of pricing, and production volumes are remarkably low. Currently, there is a lot of attention to green gas which stems from upgraded biogas, which is

  8. The Evolving Resource Metadata Infrastructure

    Science.gov (United States)

    Biemesderfer, Chris

    The search and discovery mechanisms that will facilitate and simplify systematic research on the Internet depend on systematic classifications of resources, as well as on standardized access to such metadata. The principles and technologies that will make this possible are evolving in the work of the Internet Engineering Task Force and the digital library initiatives, among others. The desired outcome is a set of standards, tools, and practices that permits both cataloging and retrieval to be comprehensive and efficient.

  9. Permeability in Rotliegend gas sandstones to gas and brine as predicted from NMR, mercury injection and image analysis

    DEFF Research Database (Denmark)

    Rosenbrand, Esther; Fabricius, Ida Lykke; Fisher, Quentin

    2015-01-01

    Permeability characterisation of low permeability, clay-rich gas sandstones is part of production forecasting and reservoir management. The physically based Kozeny (1927) equation linking permeability with porosity and pore size is derived for a porous medium with a homogeneous pore size, whereas...

  10. "Second order" exploratory data analysis of the large scale gas injection test (lasgit) dataset, focused around known gas migration events

    NARCIS (Netherlands)

    Bennett, D.; Cuss, R.; Vardon, P.J.; Harrington, J.; Sedighi, M.; Shaw, R.; Thomas, H.

    2013-01-01

    Within large-scale experimental datasets a wealth of small scale information can typically be found. An example of such an experiment is the Large Scale Gas Injection Test (Lasgit). A toolkit has been developed to facilitate the investigation of the small scale or ‘second order’ detail contained

  11. Generic Analysis Methods for Gas Turbine Engine Performance : The development of the gas turbine simulation program GSP

    NARCIS (Netherlands)

    Visser, W.P.J.

    2015-01-01

    Numerical modelling and simulation have played a critical role in the research and development towards today’s powerful and efficient gas turbine engines for both aviation and power generation. The simultaneous progress in modelling methods, numerical methods, software development tools and methods,

  12. Analysis of transient fission gas behaviour in oxide fuel using BISON and TRANSURANUS

    Science.gov (United States)

    Barani, T.; Bruschi, E.; Pizzocri, D.; Pastore, G.; Van Uffelen, P.; Williamson, R. L.; Luzzi, L.

    2017-04-01

    The modelling of fission gas behaviour is a crucial aspect of nuclear fuel performance analysis in view of the related effects on the thermo-mechanical performance of the fuel rod, which can be particularly significant during transients. In particular, experimental observations indicate that substantial fission gas release (FGR) can occur on a small time scale during transients (burst release). To accurately reproduce the rapid kinetics of the burst release process in fuel performance calculations, a model that accounts for non-diffusional mechanisms such as fuel micro-cracking is needed. In this work, we present and assess a model for transient fission gas behaviour in oxide fuel, which is applied as an extension of conventional diffusion-based models to introduce the burst release effect. The concept and governing equations of the model are presented, and the sensitivity of results to the newly introduced parameters is evaluated through an analytic sensitivity analysis. The model is assessed for application to integral fuel rod analysis by implementation in two structurally different fuel performance codes: BISON (multi-dimensional finite element code) and TRANSURANUS (1.5D code). Model assessment is based on the analysis of 19 light water reactor fuel rod irradiation experiments from the OECD/NEA IFPE (International Fuel Performance Experiments) database, all of which are simulated with both codes. The results point out an improvement in both the quantitative predictions of integral fuel rod FGR and the qualitative representation of the FGR kinetics with the transient model relative to the canonical, purely diffusion-based models of the codes. The overall quantitative improvement of the integral FGR predictions in the two codes is comparable. Moreover, calculated radial profiles of xenon concentration after irradiation are investigated and compared to experimental data, illustrating the underlying representation of the physical mechanisms of burst release.

  13. Gulf of Mexico Gas Hydrate Joint Industry Project Leg II logging-while-drilling data acquisition and analysis

    Science.gov (United States)

    Collett, Timothy S.; Lee, Wyung W.; Zyrianova, Margarita V.; Mrozewski, Stefan A.; Guerin, Gilles; Cook, Ann E.; Goldberg, Dave S.

    2012-01-01

    One of the objectives of the Gulf of Mexico Gas Hydrate Joint Industry Project Leg II (GOM JIP Leg II) was the collection of a comprehensive suite of logging-while-drilling (LWD) data within gas-hydrate-bearing sand reservoirs in order to make accurate estimates of the concentration of gas hydrates under various geologic conditions and to understand the geologic controls on the occurrence of gas hydrate at each of the sites drilled during this expedition. The LWD sensors just above the drill bit provided important information on the nature of the sediments and the occurrence of gas hydrate. There has been significant advancements in the use of downhole well-logging tools to acquire detailed information on the occurrence of gas hydrate in nature: From using electrical resistivity and acoustic logs to identify gas hydrate occurrences in wells to where wireline and advanced logging-while-drilling tools are routinely used to examine the petrophysical nature of gas hydrate reservoirs and the distribution and concentration of gas hydrates within various complex reservoir systems. Recent integrated sediment coring and well-log studies have confirmed that electrical resistivity and acoustic velocity data can yield accurate gas hydrate saturations in sediment grain supported (isotropic) systems such as sand reservoirs, but more advanced log analysis models are required to characterize gas hydrate in fractured (anisotropic) reservoir systems. In support of the GOM JIP Leg II effort, well-log data montages have been compiled and presented in this report which includes downhole logs obtained from all seven wells drilled during this expedition with a focus on identifying and characterizing the potential gas-hydrate-bearing sedimentary section in each of the wells. Also presented and reviewed in this report are the gas-hydrate saturation and sediment porosity logs for each of the wells as calculated from available downhole well logs.

  14. Environmental Stress Testing of the Single Sample Cylinder: A Proven Consensus Standard for Internal Gas Analysis (IGA) or Residual Gas Analysis (RGA)

    Science.gov (United States)

    Schuessler, Philipp WH

    2010-01-01

    In August 2008, Schuessler Consulting was contracted by NASA GSFC in support of the NASA Electronic Parts and Packaging (NEPP) program to perform two separate studies on moisture laden air in a stainless steel cylinder that had been designed to become a consensus standard for Test Method 1018. This Test Method was originally released for hybrids under Mil. Std. 883 but was quickly utilized on other microelectronic devices under the auspice of Mil. Std. 750. The cylinder had subsequently been fabricated for the 750 community. It was back-filled with moist air and subsequently analyzed over a period of time under a previous NASA contract. It had been shown that moisture in the 4000 - 5000 ppm range could be analyzed rather precisely with a mass spectrometer, commonly referred to as a Residual Gas Analyzer (RGA). The scope of this study was to ascertain if the composition and precision varied as a function of thermal shock at sub-zero temperatures and whether there was consensus when the standard was submitted to other RGA units. It was demonstrated and published that the consensus standard would yield precise RGA data for moisture within +/- 1% when optimized for a given RGA unit. It has been subsequently shown in this study at Oneida Research Services, that sub-zero storage did not affect that precision when a well-defined protocol for the analysis was followed. The consensus standard was taken to a second facility for analysis where it was found that moisture adsorption on the transfer lines caused precision to drop to +/- 12%. The Single Sample Cylinder (SSC) is a one liter stainless steel cylinder with associated sampling valves and has considerable weight and volume. But this considerable size allows for approximately 300 gas samples of the same composition to be delivered to any RGA unit. Lastly, a smaller cylinder, approximately 75 cc, of a second consensus standard was fabricated and tested with a different mix of fixed gases where moisture was kept in the

  15. Ranking in evolving complex networks

    Science.gov (United States)

    Liao, Hao; Mariani, Manuel Sebastian; Medo, Matúš; Zhang, Yi-Cheng; Zhou, Ming-Yang

    2017-05-01

    Complex networks have emerged as a simple yet powerful framework to represent and analyze a wide range of complex systems. The problem of ranking the nodes and the edges in complex networks is critical for a broad range of real-world problems because it affects how we access online information and products, how success and talent are evaluated in human activities, and how scarce resources are allocated by companies and policymakers, among others. This calls for a deep understanding of how existing ranking algorithms perform, and which are their possible biases that may impair their effectiveness. Many popular ranking algorithms (such as Google's PageRank) are static in nature and, as a consequence, they exhibit important shortcomings when applied to real networks that rapidly evolve in time. At the same time, recent advances in the understanding and modeling of evolving networks have enabled the development of a wide and diverse range of ranking algorithms that take the temporal dimension into account. The aim of this review is to survey the existing ranking algorithms, both static and time-aware, and their applications to evolving networks. We emphasize both the impact of network evolution on well-established static algorithms and the benefits from including the temporal dimension for tasks such as prediction of network traffic, prediction of future links, and identification of significant nodes.

  16. Flammable Gas Refined Safety Analysis Tool Software Verification and Validation Report for Resolve Version 2.5

    Energy Technology Data Exchange (ETDEWEB)

    BRATZEL, D.R.

    2000-09-28

    The purpose of this report is to document all software verification and validation activities, results, and findings related to the development of Resolve Version 2.5 for the analysis of flammable gas accidents in Hanford Site waste tanks.

  17. Multivariate analysis of progressive thermal desorption coupled gas chromatography-mass spectrometry.

    Energy Technology Data Exchange (ETDEWEB)

    Van Benthem, Mark Hilary; Mowry, Curtis Dale; Kotula, Paul Gabriel; Borek, Theodore Thaddeus, III

    2010-09-01

    Thermal decomposition of poly dimethyl siloxane compounds, Sylgard{reg_sign} 184 and 186, were examined using thermal desorption coupled gas chromatography-mass spectrometry (TD/GC-MS) and multivariate analysis. This work describes a method of producing multiway data using a stepped thermal desorption. The technique involves sequentially heating a sample of the material of interest with subsequent analysis in a commercial GC/MS system. The decomposition chromatograms were analyzed using multivariate analysis tools including principal component analysis (PCA), factor rotation employing the varimax criterion, and multivariate curve resolution. The results of the analysis show seven components related to offgassing of various fractions of siloxanes that vary as a function of temperature. Thermal desorption coupled with gas chromatography-mass spectrometry (TD/GC-MS) is a powerful analytical technique for analyzing chemical mixtures. It has great potential in numerous analytic areas including materials analysis, sports medicine, in the detection of designer drugs; and biological research for metabolomics. Data analysis is complicated, far from automated and can result in high false positive or false negative rates. We have demonstrated a step-wise TD/GC-MS technique that removes more volatile compounds from a sample before extracting the less volatile compounds. This creates an additional dimension of separation before the GC column, while simultaneously generating three-way data. Sandia's proven multivariate analysis methods, when applied to these data, have several advantages over current commercial options. It also has demonstrated potential for success in finding and enabling identification of trace compounds. Several challenges remain, however, including understanding the sources of noise in the data, outlier detection, improving the data pretreatment and analysis methods, developing a software tool for ease of use by the chemist, and demonstrating our belief

  18. Peripheral venous and arterial blood gas analysis in adults: are they comparable? A systematic review and meta-analysis.

    Science.gov (United States)

    Byrne, Anthony L; Bennett, Michael; Chatterji, Robindro; Symons, Rebecca; Pace, Nathan L; Thomas, Paul S

    2014-02-01

    Peripheral venous blood gas (PVBG) analysis is increasingly being used as a substitute for arterial blood sampling; however, comparability has not been clearly established. To determine if the pH, PCO2 and PO2 obtained from PVBG analysis is comparable with arterial blood gas (ABG) analysis. A search was conducted of electronic databases as well as hand-searching of journals and reference lists through December 2012 to identify studies comparing PVBG with ABG analysis in adult subjects. A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. A meta-analysis using a random effects model was used to calculate the average difference (bias) and the limits of agreement for the venous and arterial pH, PCO2 and PO2 . A total of 18 studies comprising 1768 subjects were included in the meta-analysis. There was considerable heterogeneity between studies with I(2) approaching 100%. There was little difference between the pH obtained from the PVBG and the ABG, with the arterial pH typically 0.03 higher than the venous pH (95% confidence interval 0.029-0.038). The venous and arterial PCO2 were not comparable because the 95% prediction interval of the bias for venous PCO2 was unacceptably wide, extending from -10.7 mm Hg to +2.4 mm Hg. The PO2 values compared poorly, the arterial PO2 typically 36.9 mm Hg greater than the venous with significant variability (95% confidence interval from 27.2 to 46.6 mm Hg). PVBG analysis compares well with ABG analysis for pH estimations in adults but not to the PCO2 or PO2 . These differences are sufficiently large to be of clinical significance. © 2014 The Authors. Respirology © 2014 Asian Pacific Society of Respirology.

  19. ASSESSMENT OF DIVERSITY OF POLISH VOIVODSHIPS BY LEVEL OF GAS PIPELINE INFRASTRUCTURE DEVELOPMENT USING MULTIDIMENSIONAL COMPARATIVE ANALYSIS

    Directory of Open Access Journals (Sweden)

    Marek URBANIK

    2016-06-01

    Full Text Available In the paper differentiation of gas pipeline infrastructure development in the Polish voivodships was presented. To illustrate this diversity the method of cluster analysis is used, obtained on the basis of statistical data collected by the Central Statistical Office (CSO. In order to conduct a preliminary review procedure for classification of individual provinces in relation to the assessment of the development of gas pipeline infrastructure linear classification was used, involved determining synthetic measure, which is the average of the variable components, through which voivodships were ordered. In order to estimate the distance between the clusters the variance analysis was used with the implementation of the Ward method. The analysis was performed on the basis of the following indicators: average increase in length of the gas network (an average for the total voivodoship 164.2 km, growth of the gas network in comparison to the first year of observation (123%, number of gas connections per 1 km of gas pipe (18.87 no∙km-1, the length of the network per unit area (5.37 m∙ha-1, intensity of network loading (84.15 m3∙d-1∙km-1, inhabitants having access to the gas system in % of total population (51.33%. In the analysis five clusters were grouped. Critical value was determined and segregation of individual clusters was made, taking into account the dominant parameters.

  20. Extremely sensitive CWA analyzer based on a novel optical pressure sensor in photoacoustic gas analysis

    Science.gov (United States)

    Kauppinen, Jyrki K.; Koskinen, Vesa; Uotila, Juho; Kauppinen, Ismo K.

    2004-12-01

    Major improvement into the sensitivity of broadband Fourier transform infrared (FTIR) spectrometers, used in gas analysis, can be achieved by a photoacoustic detection system, which bases on a recently introduced optical pressure sensor. The sensor is a cantilever-type microphone with interferometric measurement of its free end displacement. By using a preliminary prototype of the photoacoustic gas detector, equipped with the proposed sensor and a black body radiation source, a detection limit in the sub-ppb range was obtained for e.g. methane gas. The limit, obtained in non-resonant operation mode, is very close to the best photoacoustic results achieved with powerfull laser sources and by exploiting the cell resonances. It is also orders of magnitude better than any measurement with a black body radiation source. Furthermore, the ultimate sensitivity leads on to very small detection limits also for several chemical warfare agents (CWA) e.g. sarin, tabun and mustard. The small size of the sensor and its great thermal stability enables the construction of an extremely sensitive portable CWA analyzer in the near future.

  1. Analysis of calibration interval of turbine meters used in natural gas delivery points

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Fernanda M. [TBG - Transportadora Brasileira Gasoguto Bolivia Brasil, Campinas, SP (Brazil)

    2009-12-19

    In natural gas pipeline operation, an accurate measurement of flow at delivery points provides the basis for the company billing and ensures a relationship of credibility with customers. So, the measurement management system must ensure that the equipment responsible for natural gas measurement is calibrated, although it does not mean that a high frequency of calibration must be adopted, since the calibration costs may increase without relevant gains being perceived. Therefore studying calibration frequency becomes really important in order to find the optimal point between reliability and cost. This paper aimed to evaluate the calibration frequency of the turbine flow meters used in TBG - Transportadora Brasileira Gasoduto Bolivia Brasil to measure processed gas flow at delivery points. Historical calibration data were used in commercial statistical software, which is normally used for lifetime analysis of equipment. Following such procedure, each time a meter was rejected at a calibration, it was considered a fail. The results obtained indicate that the tow year calibration interval used by TBG ensures the probability of failure, translated by the probability of producing incorrect results, of only 3%, considering their process conditions. (author)

  2. Improved machine learning method for analysis of gas phase chemistry of peptides

    Directory of Open Access Journals (Sweden)

    Ahn Natalie

    2008-12-01

    Full Text Available Abstract Background Accurate peptide identification is important to high-throughput proteomics analyses that use mass spectrometry. Search programs compare fragmentation spectra (MS/MS of peptides from complex digests with theoretically derived spectra from a database of protein sequences. Improved discrimination is achieved with theoretical spectra that are based on simulating gas phase chemistry of the peptides, but the limited understanding of those processes affects the accuracy of predictions from theoretical spectra. Results We employed a robust data mining strategy using new feature annotation functions of MAE software, which revealed under-prediction of the frequency of occurrence in fragmentation of the second peptide bond. We applied methods of exploratory data analysis to pre-process the information in the MS/MS spectra, including data normalization and attribute selection, to reduce the attributes to a smaller, less correlated set for machine learning studies. We then compared our rule building machine learning program, DataSqueezer, with commonly used association rules and decision tree algorithms. All used machine learning algorithms produced similar results that were consistent with expected properties for a second gas phase mechanism at the second peptide bond. Conclusion The results provide compelling evidence that we have identified underlying chemical properties in the data that suggest the existence of an additional gas phase mechanism for the second peptide bond. Thus, the methods described in this study provide a valuable approach for analyses of this kind in the future.

  3. Thermodynamic analysis of fuels in gas phase: ethanol, gasoline and ethanol - gasoline predicted by DFT method.

    Science.gov (United States)

    Neto, A F G; Lopes, F S; Carvalho, E V; Huda, M N; Neto, A M J C; Machado, N T

    2015-10-01

    This paper presents a theoretical study using density functional theory to calculate thermodynamics properties of major molecules compounds at gas phase of fuels like gasoline, ethanol, and gasoline-ethanol mixture in thermal equilibrium on temperature range up to 1500 K. We simulated a composition of gasoline mixture with ethanol for a thorough study of thermal energy, enthalpy, Gibbs free energy, entropy, heat capacity at constant pressure with respect to temperature in order to study the influence caused by ethanol as an additive to gasoline. We used semi-empirical computational methods as well in order to know the efficiency of other methods to simulate fuels through this methodology. In addition, the ethanol influence through the changes in percentage fractions of chemical energy released in combustion reaction and the variations on thermal properties for autoignition temperatures of fuels was analyzed. We verified how ethanol reduces the chemical energy released by gasoline combustion and how at low temperatures the gas phase fuels in thermal equilibrium have similar thermodynamic behavior. Theoretical results were compared with experimental data, when available, and showed agreement. Graphical Abstract Thermodynamic analysis of fuels in gas phase.

  4. Analysis of CO2 Separation from Flue Gas, Pipeline Transportation, and Sequestration in Coal

    Energy Technology Data Exchange (ETDEWEB)

    Eric P. Robertson

    2007-09-01

    This report was written to satisfy a milestone of the Enhanced Coal Bed Methane Recovery and CO2 Sequestration task of the Big Sky Carbon Sequestration project. The report begins to assess the costs associated with separating the CO2 from flue gas and then injecting it into an unminable coal seam. The technical challenges and costs associated with CO2 separation from flue gas and transportation of the separated CO2 from the point source to an appropriate sequestration target was analyzed. The report includes the selection of a specific coal-fired power plant for the application of CO2 separation technology. An appropriate CO2 separation technology was identified from existing commercial technologies. The report also includes a process design for the chosen technology tailored to the selected power plant that used to obtain accurate costs of separating the CO2 from the flue gas. In addition, an analysis of the costs for compression and transportation of the CO2 from the point-source to an appropriate coal bed sequestration site was included in the report.

  5. Technical and economic analysis of implementation of small scale GTL (Gas-to-Liquids) technology to monetize associated stranded natural gas offshore in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Castelo Branco, David; Szklo, Alexandre; Schaeffer, Roberto [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Programa de Planejamento Energetico

    2008-07-01

    The volume of global stranded natural gas reserves is impressive totalling more than a third of the world's proven natural gas reserves. In Brazil, recent discoveries operated by PETROBRAS with the share of other companies indicate the tendency of incorporating stranded gas reserves (associated or not) to the country's total reserves. The objective of this study is to perform a technical and economic analysis of the implementation of small-scale GTL technology for the exploitation of stranded associated natural gas offshore in Brazil. Thus, the study initially held a survey of the processes of gasification and the manufacturers of technologies and projects based on these processes, specifically for offshore applications. Then, the offshore environment conditions were examined. After the confrontation of the available technologies and the operational conditions, one technology was chosen to be assessed by the economic analysis. The results show that GTL offshore option becomes feasible for the minimum oil price of approximately $50.00 per barrel. This price is greater than the value of robustness adopted by PETROBRAS, however there is still the possibility of cost reductions for the feasibility of new technologies. (author)

  6. Evolving Yangtze River reconstructed by detrital zircon U-Pb dating and petrographic analysis of Miocene marginal Sea sedimentary rocks of the Western Foothills and Hengchun Peninsula, Taiwan

    Science.gov (United States)

    Zhang, Xinchang; Huang, Chiyue; Wang, Yuejun; Clift, Peter D.; Yan, Yi; Fu, Xiaowei; Chen, Duofu

    2017-04-01

    The timing of the establishment of the Yangtze River, whether prior to the early Miocene ( 24 Ma) or more recently ( 2 Ma), has been a point of much debate. Here we applied detrital zircon U-Pb dating to Miocene sedimentary rocks from Taiwan and to estuary sands from modern rivers in SE China to trace sediment provenance and to further constrain the evolution of the Yangtze River. Detrital zircon U-Pb ages from Miocene sandstones of the Western Foothills show similar age spectra to Miocene and modern sediments in the Yangtze River drainage and some similarity to the Minjiang River sediments. However, they differ significantly from ages in some sandstones from the Hengchun Peninsula accretionary prism and from the estuary sands of the Jiulongjiang River. This information, together with petrographic and sedimentary facies analysis, argues that the Jiulongjiang and Minjiang Rivers were major sources to some Hengchun Peninsula turbidites ( 12 Ma), while synchronous sedimentation in the Western Foothills was supplied from the Yangtze, Minjiang (or similar river), and possibly even the Yellow River. These sediments were transported southward/eastward via rivers or channels to the marginal sedimentary basins now inverted in the Western Foothills in Taiwan. The Yangtze River must have been established prior to the middle Miocene.

  7. The Evolving Mcart Multimodal Imaging Core: Establishing a Protocol for Computed Tomography and Echocardiography in the Rhesus Macaque to Perform Longitudinal Analysis of Radiation-Induced Organ Injury.

    Science.gov (United States)

    de Faria, Eduardo B; Barrow, Kory R; Ruehle, Bradley T; Parker, Jordan T; Swartz, Elisa; Taylor-Howell, Cheryl; Kieta, Kaitlyn M; Lees, Cynthia J; Sleeper, Meg M; Dobbin, Travis; Baron, Adam D; Mohindra, Pranshu; MacVittie, Thomas J

    2015-11-01

    Computed Tomography (CT) and Echocardiography (EC) are two imaging modalities that produce critical longitudinal data that can be analyzed for radiation-induced organ-specific injury to the lung and heart. The Medical Countermeasures Against Radiological Threats (MCART) consortium has a well established animal model research platform that includes nonhuman primate (NHP) models of the acute radiation syndrome and the delayed effects of acute radiation exposure. These models call for a definition of the latency, incidence, severity, duration, and resolution of different organ-specific radiation-induced subsyndromes. The pulmonary subsyndromes and cardiac effects are a pair of interdependent syndromes impacted by exposure to potentially lethal doses of radiation. Establishing a connection between these will reveal important information about their interaction and progression of injury and recovery. Herein, the authors demonstrate the use of CT and EC data in the rhesus macaque models to define delayed organ injury, thereby establishing: a) consistent and reliable methodology to assess radiation-induced damage to the lung and heart; b) an extensive database in normal age-matched NHP for key primary and secondary endpoints; c) identified problematic variables in imaging techniques and proposed solutions to maintain data integrity; and d) initiated longitudinal analysis of potentially lethal radiation-induced damage to the lung and heart.

  8. Thermal analysis and its application in evaluation of fluorinated polyimide membranes for gas separation

    KAUST Repository

    Qiu, Wulin

    2011-08-01

    Seven polyimides based on (4,4′-hexafluoroisopropylidene) diphthalic anhydride, 6FDA, with different chemical structures were synthesized in a single pot two-step procedure by first producing a high molecular weight polyamic acid (PAA), followed by reaction with acetic anhydride to produce polyimide (PI). The resulting polymers were characterized using thermal analysis techniques including TGA, derivative weight analysis, TGA-MS, and DSC. The decarboxylation-induced thermal cross-linking, ester cross-linking through a diol, and ion-exchange reactions of selected polyimide membranes were investigated. Cross-linking of polymer membranes was confirmed by solubility tests and CO 2 permeability measurements. The thermal analysis provides simple and timesaving opportunities to characterize the polymer properties, the ability to optimize polymer cross-linking conditions, and to monitor polymer functionalization to develop high performance polymeric membranes for gas separations. © 2011 Elsevier Ltd. All rights reserved.

  9. Analysis of penetration and mixing of gas jets in supersonic cross flow

    Science.gov (United States)

    Billig, F. S.; Schetz, J. A.

    1992-01-01

    The JETPEN analysis for gas jets in a supersonic cross flow developed earlier at APL/JHU has been extended in several important ways. First, the treatment of cases with injection at angles other than 90 deg has been redone. Next, the second of the three regions formerly treated has been eliminated. Third, the region downstream of the Mach disk for underexpanded cases has been reformulated such that turbulent entrainment of main stream fluid into the plume is modeled, and the equations of motion are solved marching downstream. These changes now permit prediction of the variation in composition, mixing area growth and all other flow variables along the plume. The analysis has been verified by comparison of predictions and experiment over a wide range of conditions. The result is an analysis capable of reliable predictions of the major flowfield variables that can be run on a PC.

  10. Total fuel-cycle analysis of heavy-duty vehicles using biofuels and natural gas-based alternative fuels.

    Science.gov (United States)

    Meyer, Patrick E; Green, Erin H; Corbett, James J; Mas, Carl; Winebrake, James J

    2011-03-01

    Heavy-duty vehicles (HDVs) present a growing energy and environmental concern worldwide. These vehicles rely almost entirely on diesel fuel for propulsion and create problems associated with local pollution, climate change, and energy security. Given these problems and the expected global expansion of HDVs in transportation sectors, industry and governments are pursuing biofuels and natural gas as potential alternative fuels for HDVs. Using recent lifecycle datasets, this paper evaluates the energy and emissions impacts of these fuels in the HDV sector by conducting a total fuel-cycle (TFC) analysis for Class 8 HDVs for six fuel pathways: (1) petroleum to ultra low sulfur diesel; (2) petroleum and soyoil to biodiesel (methyl soy ester); (3) petroleum, ethanol, and oxygenate to e-diesel; (4) petroleum and natural gas to Fischer-Tropsch diesel; (5) natural gas to compressed natural gas; and (6) natural gas to liquefied natural gas. TFC emissions are evaluated for three greenhouse gases (GHGs) (carbon dioxide, nitrous oxide, and methane) and five other pollutants (volatile organic compounds, carbon monoxide, nitrogen oxides, particulate matter, and sulfur oxides), along with estimates of total energy and petroleum consumption associated with each of the six fuel pathways. Results show definite advantages with biodiesel and compressed natural gas for most pollutants, negligible benefits for e-diesel, and increased GHG emissions for liquefied natural gas and Fischer-Tropsch diesel (from natural gas).

  11. Monte Carlo Analysis of the Battery-Type High Temperature Gas Cooled Reactor

    Science.gov (United States)

    Grodzki, Marcin; Darnowski, Piotr; Niewiński, Grzegorz

    2017-12-01

    The paper presents a neutronic analysis of the battery-type 20 MWth high-temperature gas cooled reactor. The developed reactor model is based on the publicly available data being an `early design' variant of the U-battery. The investigated core is a battery type small modular reactor, graphite moderated, uranium fueled, prismatic, helium cooled high-temperature gas cooled reactor with graphite reflector. The two core alternative designs were investigated. The first has a central reflector and 30×4 prismatic fuel blocks and the second has no central reflector and 37×4 blocks. The SERPENT Monte Carlo reactor physics computer code, with ENDF and JEFF nuclear data libraries, was applied. Several nuclear design static criticality calculations were performed and compared with available reference results. The analysis covered the single assembly models and full core simulations for two geometry models: homogenous and heterogenous (explicit). A sensitivity analysis of the reflector graphite density was performed. An acceptable agreement between calculations and reference design was obtained. All calculations were performed for the fresh core state.

  12. Monte Carlo Analysis of the Battery-Type High Temperature Gas Cooled Reactor

    Directory of Open Access Journals (Sweden)

    Grodzki Marcin

    2017-12-01

    Full Text Available The paper presents a neutronic analysis of the battery-type 20 MWth high-temperature gas cooled reactor. The developed reactor model is based on the publicly available data being an ‘early design’ variant of the U-battery. The investigated core is a battery type small modular reactor, graphite moderated, uranium fueled, prismatic, helium cooled high-temperature gas cooled reactor with graphite reflector. The two core alternative designs were investigated. The first has a central reflector and 30×4 prismatic fuel blocks and the second has no central reflector and 37×4 blocks. The SERPENT Monte Carlo reactor physics computer code, with ENDF and JEFF nuclear data libraries, was applied. Several nuclear design static criticality calculations were performed and compared with available reference results. The analysis covered the single assembly models and full core simulations for two geometry models: homogenous and heterogenous (explicit. A sensitivity analysis of the reflector graphite density was performed. An acceptable agreement between calculations and reference design was obtained. All calculations were performed for the fresh core state.

  13. Subacute Ruminal Acidosis and Evaluation of Blood Gas Analysis in Dairy Cow

    Directory of Open Access Journals (Sweden)

    Matteo Gianesella

    2010-01-01

    Full Text Available Subacute Ruminal Acidosis (SARA corresponds to an imbalance between lactate-producing bacteria and lactate-using bacteria, which results in a change in ruminal pH associated with a prevalent consumption of rapidly fermentable carbohydrates. In our study, 216 primiparus and multiparus dairy cows were selected from 20 Italian intensive dairy herds and were divided into three groups based on the risk of SARA. All the dairy cows had high average milk production. After blood sampling, a complete blood gas analysis was performed. One-way ANOVA was performed to compare the three groups. O2 Cont, PCO2, blood pH, O2Hb, urinary pH, and rumen pH were significantly lower in cows with rumen pH<5.5. These results indicate that blood gas analysis is a valuable tool to diagnose acidosis in dairy cows because it provides good assessment of acidosis while being less invasive than rumen pH analysis.

  14. Thermodynamic Analysis and Reduction of MnO2 by Methane-Hydrogen Gas Mixture

    Science.gov (United States)

    Liu, Bingbing; Zhang, Yuanbo; Su, Zijian; Peng, Zhiwei; Li, Guanghui; Jiang, Tao

    2017-09-01

    Methane and hydrogen reduction has emerged as promising technology for clean and efficient metallurgy. To understand the reduction process of MnO2 by CH4-H2 gas mixture, the effects of various CH4/(CH4 + H2) molar ratios (0-1) and temperatures (1100°C-1250°C) on the reduction of pure MnO2 were researched. Characterization of the solid carbon derived from the decomposition of CH4 gas was also determined. Thermodynamic analysis indicated that the MnO2 was first reduced to MnO by CH4-H2 gas mixture, and then MnO was reduced to Mn7C3 according to this reaction, 7MnO(s) + 10CH4(g) = Mn7C3(s) + 7CO(g) + 20H2(g). Experimental results showed that under the CH4/(CH4 + H2) molar ratio of 0.2, the reduction extent of MnO2 increased with the rising of temperatures. Nevertheless, the deep reduction of MnO to Mn7C3 was retarded even by increasing the temperature and prolonging the time, which was a result of the formation of deposited solid carbon. The free carbon contents in the reduced samples increased with the increasing of the CH4/(CH4 + H2) molar ratio and reduction time. The reduction of MnO2 and formation of carbon can be regulated by adjusting the CH4/(CH4 + H2) molar ratio in a gas mixture. For example, when MnO2 was reduced by 50 vol.%CH4-50%N2, large amounts of MnO and Mn7C3 particles were wrapped by the platelike and rodlike carbon with nanoscale. Yet, the wrapping phenomenon cannot be observed under 10 vol.%CH4-40 vol.%H2-50 vol.%N2.

  15. Application of spectral analysis in radiometric measurements of twophase liquid-gas flow

    Directory of Open Access Journals (Sweden)

    Zych Marcin

    2014-01-01

    Full Text Available This article presents use of the classical spectral analysis to identify a type of flow in investigation of gas transportation by liquid with a measurement of gamma radiation absorption. During numerous experiments it was found that a magnitude of the cross-spectral density distribution of recording signals reveals type of air-water mixture flow in a horizontal pipeline. As an example, some results of laboratory measurements equipped in 241Am radiation source and scintillation probes with of NaI(Tl crystals are presented. Moreover attached figures facilitate interpretation of observed results and in details illustrating the proposed method.

  16. [Investigation of reference intervals of blood gas and acid-base analysis assays in China].

    Science.gov (United States)

    Zhang, Lu; Wang, Wei; Wang, Zhiguo

    2015-10-01

    To investigate and analyze the upper and lower limits and their sources of reference intervals in blood gas and acid-base analysis assays. The data of reference intervals were collected, which come from the first run of 2014 External Quality Assessment (EQA) program in blood gas and acid-base analysis assays performed by National Center for Clinical Laboratories (NCCL). All the abnormal values and errors were eliminated. Data statistics was performed by SPSS 13.0 and Excel 2007 referring to upper and lower limits of reference intervals and sources of 7 blood gas and acid-base analysis assays, i.e. pH value, partial pressure of carbon dioxide (PCO2), partial pressure of oxygen (PO2), Na+, K+, Ca2+ and Cl-. Values were further grouped based on instrument system and the difference between each group were analyzed. There were 225 laboratories submitting the information on the reference intervals they had been using. The three main sources of reference intervals were National Guide to Clinical Laboratory Procedures [37.07% (400/1 079)], instructions of instrument manufactures [31.23% (337/1 079)] and instructions of reagent manufactures [23.26% (251/1 079)]. Approximately 35.1% (79/225) of the laboratories had validated the reference intervals they used. The difference of upper and lower limits in most assays among 7 laboratories was moderate, both minimum and maximum (i.e. the upper limits of pH value was 7.00-7.45, the lower limits of Na+ was 130.00-156.00 mmol/L), and mean and median (i.e. the upper limits of K+ was 5.04 mmol/L and 5.10 mmol/L, the upper limits of PCO2 was 45.65 mmHg and 45.00 mmHg, 1 mmHg = 0.133 kPa), as well as the difference in P2.5 and P97.5 between each instrument system group. It was shown by Kruskal-Wallis method that the P values of upper and lower limits of all the parameters were lower than 0.001, expecting the lower limits of Na+ with P value 0.029. It was shown by Mann-Whitney that the statistic differences were found among instrument

  17. Isolation and gas chromatographic analysis of lupenone and lupeol from sorbus cortex

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.M. [Chungnam National University, Taejon (Korea, Republic of); Lee, C.G. [Chongju University, Congju (Korea, Republic of)

    1999-04-01

    Lupenone and lupeol, the triterpenoids of sorbus cortex, were isolated with silica gel column chromatography and used as the standard substances for the quantitative analysis. The compounds were identified with IR, NMR, EI-MS. They were separated on VA-5MS [(5%-phenyl)methlypolysiloxane, 30m*0.25mm, 0.25 {mu}m] column by gas-chromatograph. The contents of lupeone and lupeol in three different samples of Sorbus Cortex were in the range of 0.050{approx}0.056% and 0.772{approx}0.834%, respectively. 15 refs., 6 figs., 2 tabs.

  18. Comparative characteristic of concentration units relating to reference materials for gas chromatography analysis of hydrocarbon samples

    Directory of Open Access Journals (Sweden)

    S. A. Arystanbekova

    2014-01-01

    Full Text Available Application of a method of absolute calibration relating to gas chromatography analysis of liquid hydrocarbon samples is considered. It is shown for this task that both from theoretical, and practical points of view the optimum concentration unit is mass (not molar fraction. Information on average molar mass of the analyzed sample is necessary for the determination of analytes in liquid hydrocarbon samples in terms of mole fraction. Meanwhile, the normative documents of rather high rank (ASTM, ISO, GOST, GOST R concerning methods of the determination of average molar weight of samples of such a kind are absent.

  19. Roadmap for Development of Natural Gas Vehicle Fueling Infrastructructure and Analysis of Vehicular Natural Gas Consumption by Niche Sector

    Energy Technology Data Exchange (ETDEWEB)

    Stephen C. Yborra

    2007-04-30

    Vehicular natural gas consumption is on the rise, totaling nearly 200 million GGEs in 2005, despite declines in total NGV inventory in recent years. This may be attributed to greater deployment of higher fuel use medium- and heavy-duty NGVs as compared to the low fuel use of the natural gas-powered LDVs that exited the market through attrition, many of which were bi-fuel. Natural gas station counts are down to about 1100 from their peak of about 1300. Many of the stations that closed were under-utilized or not used at all while most new stations were developed with greater attention to critical business fundamentals such as site selection, projected customer counts, peak and off-peak fueling capacity needs and total station throughput. Essentially, the nation's NGV fueling infrastructure has been--and will continue--going through a 'market correction'. While current economic fundamentals have shortened payback and improved life-cycle savings for investment in NGVs and fueling infrastructure, a combination of grants and other financial incentives will still be needed to overcome general fleet market inertia to maintain status quo. Also imperative to the market's adoption of NGVs and other alternative fueled vehicle and fueling technologies is a clear statement of long-term federal government commitment to diversifying our nation's transportation fuel use portfolio and, more specifically, the role of natural gas in that policy. Based on the current NGV market there, and the continued promulgation of clean air and transportation policies, the Western Region is--and will continue to be--the dominant region for vehicular natural gas use and growth. In other regions, especially the Northeast, Mid-Atlantic states and Texas, increased awareness and attention to air quality and energy security concerns by the public and - more important, elected officials--are spurring policies and programs that facilitate deployment of NGVs and fueling

  20. Thermogravimetry-evolved gas analysis–mass spectrometry system ...

    Indian Academy of Sciences (India)

    Unknown

    –MS) system has been deve- loped. This system consists of a .... holder is connected to a data acquisition system (34970A,. M/s Agilent) for direct ..... could generate a fairly big O2 peak (corresponding Y-axis in a.u. is not shown in figure 5).

  1. Risk factors of incomplete Apgar score and umbilical cord blood gas analysis: a retrospective observational study.

    Science.gov (United States)

    van Tetering, Anne A C; van de Ven, Joost; Fransen, Annemarie F; Dieleman, Jeanne P; van Runnard Heimel, Pieter J; Oei, S Guid

    2017-11-01

    To investigate whether incomplete umbilical cord blood gas (UCBG) analysis occurs more often than the incomplete reporting of the Apgar score, and risk factors associated with the incomplete values. A total of 8824 infants born alive after 26 weeks' gestation between January 2009 and April 2013 were included. We extracted data on five-minute Apgar score, UCBG analysis, gestational age, mode of delivery, time of delivery and multiple pregnancy. Univariate and multivariable logistic regression analyses were performed. Five-minute Apgar score was incomplete in 15 cases (0.2%) and UCBG analysis in 1960 cases (22.2%), p Apgar score below seven (Odds ratio (OR) 1.68, 95% CI;1.29-2.19), gestational age between 26 to 27 6/7 and 28 to 31 6/7 weeks (OR 3.14, 95% CI; 2.13-4.62 and OR 1.91, 95% CI; 1.57-2.32), cesarean section (OR 1.31, 95% CI; 1.11-1.55), and multiple pregnancy (OR 2.02, 95% CI; 1.69-2.43). Deliveries during night time had a lower risk of incomplete UCBG analysis (OR 0.78, 95% CI; 0.69-0.88). Measuring five-minute Apgar score generated less incomplete data compared with UCBG analysis. The risk factors associated with incomplete UCBG analysis were noted. Study outcomes with UCBG analysis as neonatal assessment tool should be interpreted with caution.

  2. The evolvability of programmable hardware

    Science.gov (United States)

    Raman, Karthik; Wagner, Andreas

    2011-01-01

    In biological systems, individual phenotypes are typically adopted by multiple genotypes. Examples include protein structure phenotypes, where each structure can be adopted by a myriad individual amino acid sequence genotypes. These genotypes form vast connected ‘neutral networks’ in genotype space. The size of such neutral networks endows biological systems not only with robustness to genetic change, but also with the ability to evolve a vast number of novel phenotypes that occur near any one neutral network. Whether technological systems can be designed to have similar properties is poorly understood. Here we ask this question for a class of programmable electronic circuits that compute digital logic functions. The functional flexibility of such circuits is important in many applications, including applications of evolutionary principles to circuit design. The functions they compute are at the heart of all digital computation. We explore a vast space of 1045 logic circuits (‘genotypes’) and 1019 logic functions (‘phenotypes’). We demonstrate that circuits that compute the same logic function are connected in large neutral networks that span circuit space. Their robustness or fault-tolerance varies very widely. The vicinity of each neutral network contains circuits with a broad range of novel functions. Two circuits computing different functions can usually be converted into one another via few changes in their architecture. These observations show that properties important for the evolvability of biological systems exist in a commercially important class of electronic circuitry. They also point to generic ways to generate fault-tolerant, adaptable and evolvable electronic circuitry. PMID:20534598

  3. The 'E' factor -- evolving endodontics.

    Science.gov (United States)

    Hunter, M J

    2013-03-01

    Endodontics is a constantly developing field, with new instruments, preparation techniques and sealants competing with trusted and traditional approaches to tooth restoration. Thus general dental practitioners must question and understand the significance of these developments before adopting new practices. In view of this, the aim of this article, and the associated presentation at the 2013 British Dental Conference & Exhibition, is to provide an overview of endodontic methods and constantly evolving best practice. The presentation will review current preparation techniques, comparing rotary versus reciprocation, and question current trends in restoration of the endodontically treated tooth.

  4. An empirical analysis of ERP adoption by oil and gas firms

    Science.gov (United States)

    Romero, Jorge

    2005-07-01

    Despite the growing popularity of enterprise-resource-planning (ERP) systems for the information technology infrastructure of large and medium-sized businesses, there is limited empirical evidence on the competitive benefits of ERP implementations. Case studies of individual firms provide insights but do not provide sufficient evidence to draw reliable inferences and cross-sectional studies of firms in multiple industries provide a broad-brush perspective of the performance effects associated with ERP installations. To narrow the focus to a specific competitive arena, I analyze the impact of ERP adoption on various dimensions of performance for firms in the Oil and Gas Industry. I selected the Oil and Gas Industry because several companies installed a specific type of ERP system, SAP R/3, during the period from 1990 to 2002. In fact, SAP was the dominant provider of enterprise software to oil and gas companies during this period. I evaluate performance of firms that implemented SAP R/3 relative to firms that did not adopt ERP systems in the pre-implementation, implementation and post-implementation periods. My analysis takes two different approaches, the first from a financial perspective and the second from a strategic perspective. Using the Sloan (General Motors) model commonly applied in financial statement analysis, I examine changes in performance for ERP-adopting firms versus non-adopting firms along the dimensions of asset utilization and return on sales. Asset utilization is more closely aligned with changes in leanness of operations, and return on sales is more closely aligned with customer-value-added. I test hypotheses related to the timing and magnitude of the impact of ERP implementation with respect to leanness of operations and customer value added. I find that SAP-adopting companies performed relatively better in terms of asset turnover than non-SAP-adopting companies during both the implementation and post-implementation periods and that SAP

  5. Analysis of a gas stratification break-up by a vertical jet using the GOTHIC code

    Energy Technology Data Exchange (ETDEWEB)

    Fernández-Cosials, Mikel Kevin; Jimenez, Gonzalo, E-mail: gonzalo.jimenez@upm.es; Lopez-Alonso, Emma

    2016-02-15

    Highlights: • Study of a light gas distribution with the GOTHIC code based on the OECD/NEA IBE-3. • Sensitivity analysis on turbulence model, discretization scheme and heat transfer. • The jet erosion phenomena is captured properly with a relatively coarse mesh. • Development of a tool to evaluate the influence of each parameter on the simulation. • Several recommendation on modeling a stratification break-up are included. - Abstract: During a severe accident in light water reactor (LWR), hydrogen concentration can overpass the flammability limits locally, so the correct simulation of its behavior during a release is critical. The capability assessment of computational fluid dynamics tools to calculate the hydrogen distribution under different conditions has been the focus of intense research worldwide. In this context, the OECD/NEA conducted an international benchmark exercise (IBE-3), which was focused on the break-up of a stratified layer of a light gas by a vertical jet. The participants performed their simulations before the experiment data was released. When the data was released, it was noticed that a combination of several parameters like the mesh, turbulence model or solver controls were responsible for the broad differences between the participants’ results. To obtain information about how each parameter affects the simulation, a post-test sensitivity analysis has been done by the UPM. In this paper, the IBE-3 experiment simulation with GOTHIC 8.0 is presented along with extensive sensitivity analyses of the relevant parameters. The first objective of the work is to test the capability of GOTHIC 8.0 to simulate properly a gas stratification break-up by a vertical jet with a relatively coarse mesh. The second objective of the paper is to relate each sensitivity parameter with each other and with the experiment through the Parameter Influence Chart, a helpful tool specially designed for this purpose.

  6. Integrated cost-effectiveness analysis of greenhouse gas emission abatement. The case of Finland

    Energy Technology Data Exchange (ETDEWEB)

    Lehtilae, A.; Tuhkanen, S. [VTT Energy, Espoo (Finland). Energy Systems

    1999-11-01

    In Finland greenhouse gas emissions are expected to increase during the next decades due to economic growth, particularly in the energy intensive industrial sectors. The role of these industries is very central in the national economy. The emission control according to the Kyoto Protocol will therefore be quite difficult and costly. The study analyses the cost-effectiveness of different technical options for reducing the emissions of carbon dioxide, methane, and nitrous oxide in Finland. The analysis is performed with the help of a comprehensive energy system model for Finland, which has been extended to cover all major sources of methane and nitrous oxide emissions in the energy sector, industry, waste management and agriculture. The focus being on technical options, no consideration is given to possible policy measures, emission trading or joint implementation in the study. Under the boundary conditions given for the development of the Finnish energy economy, cost-effective technical measures in the energy system include increases in the use of wood biomass, natural gas and wind energy, increases in the contribution of CHP to the power supply, and intensified energy conservation in all end-use sectors. Additional cost-effective measures are landfill gas recovery, utilisation of the combustible fraction of waste and catalytic conversion of N{sub 2}O in nitric acid production. With baseline assumptions, the direct annual costs of emission abatement are calculated to be about 2000 MFIM (330 M{epsilon}) in 2010. The marginal costs are estimated to be about 230 FIM (40 {epsilon}) per tonne of CO{sub 2}-equivalent in 2010. The cost curie derived from the analysis could be used in further analyses concerning emissions trading. (orig.) 109 refs. SIHTI Research Programme

  7. A risk analysis for gas transport network planning expansion under regulatory uncertainty in Western Europe

    NARCIS (Netherlands)

    Pelletier, 27736; Wortmann, J.C.; Noteboom, H.J.

    The natural gas industry in Western Europe went through drastic changes induced by the unbundling of the national companies, followed by the liberalization of gas trade and the regulation of gas transmission. Natural gas transmission is operated through a network of interconnected grids, and is

  8. Steady-state analysis of the integrated natural gas and electric power system with bi-directional energy conversion

    DEFF Research Database (Denmark)

    Zeng, Qing; Fang, Jiakun; Li, Jinghua

    2016-01-01

    Nowadays, the electric power system and natural gas network are becoming increasingly coupled and interdependent. A harmonized integration of natural gas and electricity network with bi-directional energy conversion is expected to accommodate high penetration levels of renewables in terms of system...... flexibility. This work focuses on the steady-state analysis of the integrated natural gas and electric power system with bi-directional energy conversion. A unified energy flow formulation is developed to describe the nodal balance and branch flow in both systems and it is solved with the Newton...... series of wind power and power load are used to investigate the mitigation effect of the integrated energy system. At last, the effect of wind power and power demand on the output of Power to Gas (P2G) and gas-fired power generation (GPG) has also been investigated....

  9. Greenhouse gas mitigation options in the forestry sector of The Gambia: Analysis based on COMAP model

    Energy Technology Data Exchange (ETDEWEB)

    Jallow, B.P.

    1996-12-31

    Results of the 1993 Greenhouse Gas Emissions Inventory of The Gambia showed net CO{sub 2} emissions of over (1.66 x 10{sup 6} tons) and 1% was due to uptake by plantations (0.01 x 10{sup 6} tons). This is a clear indication that there is need to identify changes in the land-use policy, law and tenure that discourages forest clearing at the same time significantly influencing the sustainable distribution of land among forestry, rangeland and livestock, and agriculture. About 11% of the total area of The Gambia is either fallow or barren flats that once supported vegetation and hence is still capable of supporting vegetation. The US Country Study Programme has provided the Government of The Gambia through the National Climate Committee funds to conduct Assessment of Mitigation Options to Reduce Greenhouse Gas Emissions. The Forestry Sector is one area for which assessment is being conducted. The assessment is expected to end in September 1996. The Comprehensive Mitigation Analysis Process (COMAP) is one of the Models supplied to the National Climate Committee by the Lawrence Berkeley Laboratory, on behalf of the US Country Study Programme, and is being used to conduct the analysis in The Gambia.

  10. Analysis of Precooling Injection Transient of Steam Generator for High Temperature Gas Cooled Reactor

    Directory of Open Access Journals (Sweden)

    Yan Wang

    2017-01-01

    Full Text Available After a postulated design basis accident leads high temperature gas cooled reactor to emergency shutdown, steam generator still remains with high temperature level and needs to be cooled down by a precooling before reactor restarts with clearing of fault. For the large difference of coolant temperature between inlet and outlet of steam generator in normal operation, the temperature distribution on the components of steam generator is very complicated. Therefore, the temperature descending rate of the components in steam generator needs to be limited to avoid the potential damage during the precooling stage. In this paper, a pebble-bed high temperature gas cooled reactor is modeled by thermal-hydraulic system analysis code and several postulated precooling injection transients are simulated and compared to evaluate their effects, which will provide support for the precooling design. The analysis results show that enough precooling injection is necessary to satisfy the precooling requirements, and larger mass flow rate of precooling water injection will accelerate the precooling process. The temperature decrease of steam generator is related to the precooling injection scenarios, and the maximal mass flow rate of the precooling injection should be limited to avoid the excessively quick temperature change of the structures in steam generator.

  11. Variance Analysis of Wind and Natural Gas Generation under Different Market Structures: Some Observations

    Energy Technology Data Exchange (ETDEWEB)

    Bush, B.; Jenkin, T.; Lipowicz, D.; Arent, D. J.; Cooke, R.

    2012-01-01

    Does large scale penetration of renewable generation such as wind and solar power pose economic and operational burdens on the electricity system? A number of studies have pointed to the potential benefits of renewable generation as a hedge against the volatility and potential escalation of fossil fuel prices. Research also suggests that the lack of correlation of renewable energy costs with fossil fuel prices means that adding large amounts of wind or solar generation may also reduce the volatility of system-wide electricity costs. Such variance reduction of system costs may be of significant value to consumers due to risk aversion. The analysis in this report recognizes that the potential value of risk mitigation associated with wind generation and natural gas generation may depend on whether one considers the consumer's perspective or the investor's perspective and whether the market is regulated or deregulated. We analyze the risk and return trade-offs for wind and natural gas generation for deregulated markets based on hourly prices and load over a 10-year period using historical data in the PJM Interconnection (PJM) from 1999 to 2008. Similar analysis is then simulated and evaluated for regulated markets under certain assumptions.

  12. Dual-Section DFB-QCLs for Multi-Species Trace Gas Analysis

    Directory of Open Access Journals (Sweden)

    Martin J. Süess

    2016-04-01

    Full Text Available We report on the dynamic behavior of dual-wavelength distributed feedback (DFB quantum cascade lasers (QCLs in continuous wave and intermittent continuous wave operation. We investigate inherent etaloning effects based on spectrally resolved light-current-voltage (LIV characterization and perform time-resolved spectral analysis of thermal chirping during long (>5 µs current pulses. The theoretical aspects of the observed behavior are discussed using a combination of finite element method simulations and transfer matrix method calculations of dual-section DFB structures. Based on these results, we demonstrate how the internal etaloning can be minimized using anti-reflective (AR coatings. Finally, the potential and benefits of these devices for high precision trace gas analysis are demonstrated using a laser absorption spectroscopic setup. Thereby, the atmospherically highly relevant compounds CO2 (including its major isotopologues, CO and N2O are simultaneously determined with a precision of 0.16 ppm, 0.22 ppb and 0.26 ppb, respectively, using a 1-s integration time and an optical path-length of 36 m. This creates exciting new opportunities in the development of compact, multi-species trace gas analyzers.

  13. Measurement and Analysis of Gas Bubbles Near a Reference Electrode in Aqueous Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Supathorn Phongikaroon; Steve Herrmann; Shelly Li; Michael Simpson

    2005-10-01

    Bubble size distributions (BSDs) near a reference electrode (RE) in aqueous glycerol solutions of an electrolyte NaCl have been investigated under various gas superficial velocities (U{sub S}). BSD and voltage reading of the solution were measured by using a high-speed digital camera and a pH/voltage meter, respectively. The results show that bubble size (b) increases with liquid viscosity ({mu}{sub c}) and U{sub S}. Self-similarity is seen and can be described by the log-normal form of the continuous number frequency distribution. The result shows that b controls the voltage reading in each solution. As b increases, the voltage increases because of gas bubbles interrupting their electrolyte paths in the solutions. An analysis of bubble rising velocity reveals that Stokes Law should be used cautiously to describe the system. The fundamental equation for bubble formation was developed via Newton's second law of motion and shown to be the function of three dimensionless groups--Weber number, Bond number, and Capillary number. After linking an electrochemical principle in the practical application, the result indicates that the critical bubble size is {approx}177 {micro}m. Further analysis suggests that there may be 3000 to 70,000 bubbles generated on the anode surface depending on the size of initial bubbles and provides the potential cause of the efficiency drop observed in the practical application.

  14. Correlation of central venous pressure with venous blood gas analysis parameters; a diagnostic study

    Directory of Open Access Journals (Sweden)

    Sima Rahim-Taleghani

    2017-03-01

    Full Text Available Objective: This study was conducted to assess the correlation between central venous pressure (CVP and venous blood gas (VBG analysis parameters, to facilitate management of severe sepsis and septic shock in emergency department. Material and methods: This diagnostic study was conducted from January 2014 until June 2015 in three major educational medical centers, Tehran, Iran. For patients selected with diagnosis of septic shock, peripheral blood sample was taken for testing the VBG parameters and the anion gap (AG was calculated. All the mentioned parameters were measured again after infusion of 500 cc of normal saline 0.9% in about 1 h. Results: Totally, 93 patients with septic shock were enrolled, 63 male and 30 female. The mean age was 72.53 ± 13.03 and the mean Shock Index (SI before fluid therapy was 0.79 ± 0.30. AG and pH showed significant negative correlations with CVP, While HCO3 showed a significant positive correlation with CVP. These relations can be affected by the treatment modalities used in shock management such as fluid therapy, mechanical ventilation and vasopressor treatment. Conclusion: It is likely that there is a significant statistical correlation between VBG parameters and AG with CVP, but further research is needed before implementation of the results of this study. Keywords: Shock, Septic, Central venous pressure, Blood gas analysis, Emergency department, Emergency medicine

  15. Analysis of Specific Features of the Ukrainian Market of Natural Gas Production and Consumption

    OpenAIRE

    Lelyuk Oleksiy V.

    2013-01-01

    The article provides results of the study of specific features of the Ukrainian market of natural gas production and consumption. It analyses dynamics of the specific weight of Ukraine in general volumes of natural gas consumption in the world, dynamics of natural gas consumption in Ukraine during 1990 – 2012 and dependence of natural gas consumption on GDP volumes by the purchasing power parity. It studies the structure of natural gas consumption by regions in 2012 and sectors of economy, re...

  16. NEUTRONICS ANALYSIS ON MINI TEST FUEL IN THE RSG-GAS CORE

    Directory of Open Access Journals (Sweden)

    Tukiran Surbakti

    2016-03-01

    Full Text Available Abstract NEUTRONICS ANALYSIS ON MINI TEST FUEL IN THE RSG-GAS CORE. Research of UMo fuel for research reactor has been developing  right now. The fuel of  research reactor used is uranium low enrichment with high density. For supporting the development of fuel, an assessment of mini fuel in the RSG-GAS core was performed. The mini fuel are U7Mo-Al and U6Zr-Al with densitis of 7.0gU/cc and 5.2 gU/cc, respectively. The size of both fuel are the same namely 630x70.75x1.30 mm were inserted to the 3 plates of dummy fuel. Before being irradiated in the core, a calculation for safety analysis  from neutronics and thermohydrolics aspects were required. However, in this paper will discuss safety analysis of the U7Mo-Al and U6Zr-Al mini fuels from neutronic point of view.  The calculation was done using WIMSD-5B and Batan-3DIFF code. The result showed that both of the mini fuels could be irradiated in the RSG-GAS core with burn up less than 70 % within 12 cycles of operation without over limiting the safety margin. Power density of U7Mo-Al mini fuel bigger than U6Zr-Al fuel.   Key words: mini fuel, neutronics analysis, reactor core, safety analysis   Abstrak ANALISIS NEUTRONIK ELEMEN BAKAR UJI MINI DI TERAS RSG-GAS. Penelitian tentang bahan bakar UMo untuk reaktor riset terus berkembang saat ini. Bahan bakar reaktor riset yang digunakan adalah uranium pengkayaan rendah namun densitas tinggi.  Untuk mendukung pengembangan bahan bakar dilakukan uji elemen bakar mini di teras reakror RSG-GAS dengan tujuan menentukan jumlah siklus di dalam teras sehingga tercapai fraksi bakar maksimum. Bahan bakar yang diuji adalah U7Mo-Al dengan densitas 7,0 gU/cc dan U6Zr-Al densitas 5,2 gU/cc. Ukuran kedua bahan bakar uji tersebut adalah sama 630x70,75x1,30 mm dimasukkan masing masing kedalam 3 pelat dummy bahan bakar. Sebelum diiradiasi ke dalam teras reaktor maka perlu dilakukan perhitungan keselamatan baik secara neutronik maupun termohidrolik. Dalam makalah ini

  17. Analysis of markets for biofuels - Theme: Vehicle gas market; Analys av marknaderna foer biodrivmedel - Tema: Fordonsgasmarknaden

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-07-01

    In 2011 the Energy Agency was given an annual mission, which involved analyzing the current and future markets for ethanol and bio diesel. The mission resulted in a report that did a thorough analysis of price and market mechanisms in the Swedish and international market. This year's report aims to provide a situation analysis of the markets for ethanol and bio diesel, both first and second generation, with additional focus on certain market issues. This time, the Agency has also been asked to consider the market for vehicle gas, something that was not part of the original mandate from 2011. Regarding ethanol and bio diesel so have indentations made primarily on European protection duties.

  18. Controllability analysis and decentralized control of a wet limestone flue gas desulfurization plant

    Energy Technology Data Exchange (ETDEWEB)

    Perales, A.L.V.; Ortiz, F.J.G.; Ollero, P.; Gil, F.M. [University of Seville, Seville (Spain)

    2008-12-15

    Presently, decentralized feedback control is the only control strategy used in wet limestone flue gas desulfurization (WLFGD) plants. Proper tuning of this control strategy is becoming an important issue in WLFGD plants because more stringent SO{sub 2} regulations have come into force recently. Controllability analysis is a highly valuable tool for proper design of control systems, but it has not been applied to WLFGD plants so far. In this paper a decentralized control strategy is designed and applied to a WLFGD pilot plant taking into account the conclusions of a controllability analysis. The results reveal that good SO{sub 2} control in WLFGD plants can be achieved mainly because the main disturbance of the process is well-aligned with the plant and interactions between control loops are beneficial to SO{sub 2} control.

  19. ANALYSIS OF EXHAUST GAS EMISSION IN THE MARINE TWO-STROKE SLOW-SPEED DIESEL ENGINE

    Directory of Open Access Journals (Sweden)

    Branko Lalić

    2016-09-01

    Full Text Available This paper explores the problem of exhaust emissions of the marine two-stroke slow-speed diesel engines. After establishing marine diesel engine regulations and defining the parameters influencing exhaust emissions, the simulation model of the marine two-stroke slow-speed diesel engine has been developed. Furthermore, the comparison of numerical and experimentally obtained data has been performed, resulting in achieving the model validity at 100% load, which represents a requirement for further exhaust gas analysis. Deviations obtained at the real engine and the model range from 2% to 7%. An analysis of the influential parameters such as compression ratio, exhaust valve timing and fuel injection timing has been performed. The obtained results have been compared and conclusions have been drawn.

  20. Gas Classification Using Combined Features Based on a Discriminant Analysis for an Electronic Nose

    Directory of Open Access Journals (Sweden)

    Sang-Il Choi

    2016-01-01

    Full Text Available This paper proposes a gas classification method for an electronic nose (e-nose system, for which combined features that have been configured through discriminant analysis are used. First, each global feature is extracted from the entire measurement section of the data samples, while the same process is applied to the local features of the section that corresponds to the stabilization, exposure, and purge stages. The discriminative information amounts in the individual features are then measured based on the discriminant analysis, and the combined features are subsequently composed by selecting the features that have a large amount of discriminative information. Regarding a variety of volatile organic compound data, the results of the experiment show that, in a noisy environment, the proposed method exhibits classification performance that is relatively excellent compared to the other feature types.

  1. Development of high velocity gas gun with a new trigger system-numerical analysis

    Science.gov (United States)

    Husin, Z.; Homma, H.

    2018-02-01

    In development of high performance armor vests, we need to carry out well controlled experiments using bullet speed of more than 900 m/sec. After reviewing trigger systems used for high velocity gas guns, this research intends to develop a new trigger system, which can realize precise and reproducible impact tests at impact velocity of more than 900 m/sec. A new trigger system developed here is called a projectile trap. A projectile trap is placed between a reservoir and a barrel. A projectile trap has two functions of a sealing disk and triggering. Polyamidimide is selected for the trap material and dimensions of the projectile trap are determined by numerical analysis for several levels of launching pressure to change the projectile velocity. Numerical analysis results show that projectile trap designed here can operate reasonably and stresses caused during launching operation are less than material strength. It means a projectile trap can be reused for the next shooting.

  2. Techno-economic analysis of expander-based configurations for natural gas liquefaction

    DEFF Research Database (Denmark)

    Nagy, Matteo; Nguyen, Tuong-Van; Elmegaard, Brian

    2017-01-01

    W/K and 275 kW/K. A trade-off between the power consumption and heat transfer area is found, which justifies a further economic analysis. A simplified economic analysis is set based on a discounted cash flow model. The unitary profit ranges between 0.3 and 0.85 DKK per kg of produced LNG. The most profitable......The use of liquefied natural gas (LNG) as a marine fuel is rapidly growing because of the possible economic advantages over conventional fuels and stricter environmental regulations. Production of LNG is energy-intensive because of the required temperature level of around -160°C. Three main types...... expander-based configuration is the dual-refrigerant cycle with nitrogen in the bottoming cycle. Finally, the influence of the cost correlations on the economic outcome is assessed: the compressors represent the major costs, which leads to the coincidence of the thermodynamic and economic optima....

  3. Tipping points for carbon dioxide and air pollution benefits: an energy systems analysis of natural gas verses electric technologies in the U.S. buildings sector

    Science.gov (United States)

    Our analysis examines emission trade-offs between electricity and natural gas use in the buildings sector at the system level, including upstream emissions from the electric sector and natural gas mining emissions.

  4. Application of gas chromatography analysis to quality control of residual organic solvents in clopidogrel bisulphate

    Directory of Open Access Journals (Sweden)

    Pavlović Aleksandar D.

    2014-01-01

    Full Text Available A direct-injection, split-mode capillary gas chromatographic procedure with a flame ionization detection is developed for the analysis of eight solvents used in the synthesis and purification of an anti-thrombotic drug clopidogrel bisulphate. The solvents analyzed were methanol, acetone, dichloromethane (DCM, 2-butanol, cyclohexane, toluene, acetic acid and N, N-dimethyl formamide (DMF. In addition, as a result of dehydration of 2-butanol during drying process, in clopidogrel bisulphate samples, significant amounts of 2-butanol dehydration products (1-butene, cis and trans isomers of 2-butene, 2,2'-oxydibutane and 1-(1-methylpropoxybutane may be detected. The content of each of these volatile products can be evaluated using the same gas-chromatographic method, with quantification based on the response factor established for the chromatographic peak of 2-butanol. For each solvent used in the process of clopidogrel bisulphate preparation, the procedure is validated for selectivity, linearity, recovery, precision, robustness, quantitation limit, and detection limit. All eight solvents plus five 2-butanol degradation products are fully separated. System suitability test is validated, and requirements are set. Based on a large number of result sets, retrospectively, from many different batches analyzed, conclusions were made about process variations and reliability and a lack of consistency was identified in the quality of the active substance from a particular producer source. Multivariate analysis was used as statistical technique to classify samples. From the analyzed set of 11 solvents, 6 of them were preselected based upon their occurrence in the samples and both Principal Component Analysis (PCA and Hierarchical Cluster Analysis (HCA were performed.

  5. RNA Structural Analysis by Evolving SHAPE Chemistry

    Science.gov (United States)

    Spitale, Robert C.; Flynn, Ryan A.; Torre, Eduardo A.; Kool, Eric T.; Chang, Howard Y.

    2017-01-01

    RNA is central to the flow of biological information. From transcription to splicing, RNA localization, translation, and decay, RNA is intimately involved in regulating every step of the gene expression program, and is thus essential for health and understanding disease. RNA has the unique ability to base-pair with itself and other nucleic acids to form complex structures. Hence the information content in RNA is not simply its linear sequence of bases, but is also encoded in complex folding of RNA molecules. A general chemical functionality that all RNAs have is a 2’-hydroxyl group in the ribose ring, and the reactivity of the 2'-hydroxyl in RNA is gated by local nucleotide flexibility. In other words, the 2'-hydroxyl is reactive at single-stranded and conformationally flexible positions but is unreactive at nucleotides constrained by base pairing. Recent efforts have been focused on developing reagents that modify RNA as a function of RNA 2’ hydroxyl group flexibility. Such RNA structure probing techniques can be read out by primer extension in experiments termed RNA SHAPE (Selective 2’ Hydroxyl Acylation and Primer Extension). Herein we describe the efforts devoted to the design and utilization of SHAPE probes for characterizing RNA structure. We also describe current technological advances that are being used to utilize SHAPE chemistry with deep sequencing to probe many RNAs in parallel. The merger of chemistry with genomics is sure to open the door to genome-wide exploration of RNA structure and function. PMID:25132067

  6. Earlobe arterialized capillary blood gas analysis in the intensive care unit: a pilot study.

    Science.gov (United States)

    Vaquer, Sergi; Masip, Jordi; Gili, Gisela; Gomà, Gemma; Oliva, Joan Carles; Frechette, Alexandre; Evetts, Simon; Russomano, Thais; Artigas, Antonio

    2014-01-01

    Earlobe arterialized capillary blood gas analysis can be used to estimate arterial gas content and may be suitable for diagnosis and management of critically ill patients. However, its utility and applicability in the ICU setting remains unexplored. A prospective observational validation study was designed to evaluate this technique in a cohort of mechanically ventilated adult critically ill patients admitted to a polyvalent ICU. Precision and agreement between capillary gas measures and arterial references was examined. Acute Respiratory Distress Syndrome (ARDS) diagnosis capabilities with the proposed technique were also evaluated. Finally, factors associated with sampling failure were explored. Fifty-five patients were included into this study. Precision of capillary samples was high (Coefficient of Variation PO2 = 9.8%, PCO2 = 7.7%, pH = 0.3%). PO2 measures showed insufficient agreement levels (Concordance Correlation Coefficient = 0.45; bias = 12 mmHg; percentage of error = 19.3%), whereas better agreement was observed for PCO2 and pH (Concordance Correlation Coefficient = 0.94 and 0.93 respectively; depreciable bias; percentage of error 11.4% and 0.5% respectively). The sensitivity and specificity for diagnosing ARDS were 100% and 92.3% using capillary gasometric measures. Sampling was unsuccessful in 43.6% of cases due to insufficient blood flow. Age > 65 years was independently associated with failure (odds ratio = 1.6), however hemodynamic failure and norepinephrine treatment were also influencing factors. Earlobe capillary blood gas analysis is precise and can be useful for detecting extreme gasometrical values. Diagnosis of ARDS can be done accurately using capillary measurements. Although this technique may be insufficient for precise management of patients in the ICU, it has the potential for important benefits in the acute phase of various critical conditions and in other critical care arenas, such as in emergency

  7. Meta-Analysis of Microarray Data Identifies GAS6 Expression as an Independent Predictor of Poor Survival in Ovarian Cancer

    Directory of Open Access Journals (Sweden)

    Michelle Buehler

    2013-01-01

    Full Text Available Seeking new biomarkers for epithelial ovarian cancer, the fifth most common cause of death from all cancers in women and the leading cause of death from gynaecological malignancies, we performed a meta-analysis of three independent studies and compared the results in regard to clinicopathological parameters. This analysis revealed that GAS6 was highly expressed in ovarian cancer and therefore was selected as our candidate of choice. GAS6 encodes a secreted protein involved in physiological processes including cell proliferation, chemotaxis, and cell survival. We performed immunohistochemistry on various ovarian cancer tissues and found that GAS6 expression was elevated in tumour tissue samples compared to healthy control samples (. In addition, GAS6 expression was also higher in tumours from patients with residual disease compared to those without. Our data propose GAS6 as an independent predictor of poor survival, suggesting GAS6, both on the mRNA and on the protein level, as a potential biomarker for ovarian cancer. In clinical practice, the staining of a tumour biopsy for GAS6 may be useful to assess cancer prognosis and/or to monitor disease progression.

  8. The role of quantitative uncertainty in the safety analysis of flammable gas accidents in Hanford waste tanks

    Energy Technology Data Exchange (ETDEWEB)

    Bratzel, D.R.

    1998-05-18

    Following a 1990 investigation into flammable gas generation, retention, and release mechanisms within the Hanford Site high-level waste tanks, personnel concluded that the existing Authorization Basis documentation did not adequately evaluate flammable gas hazards. The US Department of Energy Headquarters subsequently declared the flammable gas hazard as an unresolved safety issue. Although work scope has been focused on resolution of the issue, it has yet to be resolved due to considerable uncertainty regarding essential technical parameters and associated risk. Resolution of the Flammable Gas Safety Issue will include the identification of a set of controls for the Authorization Basis for the tanks which will require a safety analysis of flammable gas accidents. A traditional nuclear facility safety analysis is based primarily on the analysis of a set of bounding accidents to represent the risks of the possible accidents and hazardous conditions at a facility. While this approach may provide some indication of the bounding consequences of accidents for facilities, it does not provide a satisfactory basis for identification of facility risk or safety controls when there is considerable uncertainty associated with accident phenomena and/or data as is the case with potential flammable gas accidents at the Hanford Site. This is due to the difficulties in identifying the bounding case and reaching consensus among safety analysts, facility operations and engineering, and the regulator on the implications of the safety analysis results. In addition, the bounding cases are frequently based on simplifying assumptions that make the analysis results insensitive to variations among facilities or the impact of alternative safety control strategies. The existing safety analysis of flammable gas accidents for the Tank Waste Remediation system (TWRS) at the Hanford Site has these difficulties. However, Hanford Site personnel are developing a refined safety analysis approach

  9. Primordial evolvability: Impasses and challenges.

    Science.gov (United States)

    Vasas, Vera; Fernando, Chrisantha; Szilágyi, András; Zachár, István; Santos, Mauro; Szathmáry, Eörs

    2015-09-21

    While it is generally agreed that some kind of replicating non-living compounds were the precursors of life, there is much debate over their possible chemical nature. Metabolism-first approaches propose that mutually catalytic sets of simple organic molecules could be capable of self-replication and rudimentary chemical evolution. In particular, the graded autocatalysis replication domain (GARD) model, depicting assemblies of amphiphilic molecules, has received considerable interest. The system propagates compositional information across generations and is suggested to be a target of natural selection. However, evolutionary simulations indicate that the system lacks selectability (i.e. selection has negligible effect on the equilibrium concentrations). We elaborate on the lessons learnt from the example of the GARD model and, more widely, on the issue of evolvability, and discuss the implications for similar metabolism-first scenarios. We found that simple incorporation-type chemistry based on non-covalent bonds, as assumed in GARD, is unlikely to result in alternative autocatalytic cycles when catalytic interactions are randomly distributed. An even more serious problem stems from the lognormal distribution of catalytic factors, causing inherent kinetic instability of such loops, due to the dominance of efficiently catalyzed components that fail to return catalytic aid. Accordingly, the dynamics of the GARD model is dominated by strongly catalytic, but not auto-catalytic, molecules. Without effective autocatalysis, stable hereditary propagation is not possible. Many repetitions and different scaling of the model come to no rescue. Despite all attempts to show the contrary, the GARD model is not evolvable, in contrast to reflexively autocatalytic networks, complemented by rare uncatalyzed reactions and compartmentation. The latter networks, resting on the creation and breakage of chemical bonds, can generate novel ('mutant') autocatalytic loops from a given set of

  10. Detailed analysis of petroleum cuts by multidimensional gas chromatography; Analyse detaillee de coupes petrolieres par chromatographie en phase gazeuse multidimensionnelle

    Energy Technology Data Exchange (ETDEWEB)

    Vendeuvre, C.

    2006-01-15

    The limitations of petroleum resources implying a better valorisation of crude oil through the optimisation of production, refinery and petrochemistry processes, as well as the environmental regulations have strengthened the necessity of more detailed characterisation of petroleum products. In order to take up this challenge, efficient analytical tools have to be developed. This work demonstrates that comprehensive two-dimensional gas chromatography (GCxGC) constitutes a major advance compared to GC owing to its improved resolution power and to the structured chromatograms indicating the polarity and the volatility of hydrocarbons. The principle of GCxGC is based on the analysis of a whole sample in two independent dimensions of separation achieved using two GC columns of different selectivities; between the two columns a modulator device samples, focuses and re-injects small portions of the effluent from the first column into the second one. Since its introduction in 1991, GCxGC has known a rapid growth and has received a wide acceptance by the analytical science community. The competitive situation has considerably evolved during this thesis with the introduction of commercial systems and the two first sessions of an international symposium dedicated to this technique (Volendam, 2003 and Atlanta, 2004). The key points of the thesis concern the development of a GCxGC prototype system using dual jets CO{sub 2} technology and a data processing program; the evaluation of a retention model allowing a rational choice of operating conditions; and the application of this technique to various and complex issues. Thus, effluents from petrochemistry, refinery or pollution areas have been analysed according to the chemical classes of hydrocarbons and to their number of carbon atoms; a new method for obtaining distillation curves for each chemical group was also presented. Furthermore, the hyphenation of GCxGC with a specific sulphur detector revealed a great interest for

  11. Sensitivity analysis of an Advanced Gas-cooled Reactor control rod model

    Energy Technology Data Exchange (ETDEWEB)

    Scott, M.; Green, P.L. [Dynamics Research Group, Department of Mechanical Engineering, University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom); O’Driscoll, D. [EDF Energy, Barnett Way, Barnwood, Gloucester GL4 3RS (United Kingdom); Worden, K.; Sims, N.D. [Dynamics Research Group, Department of Mechanical Engineering, University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom)

    2016-08-15

    Highlights: • A model was made of the AGR control rod mechanism. • The aim was to better understand the performance when shutting down the reactor. • The model showed good agreement with test data. • Sensitivity analysis was carried out. • The results demonstrated the robustness of the system. - Abstract: A model has been made of the primary shutdown system of an Advanced Gas-cooled Reactor nuclear power station. The aim of this paper is to explore the use of sensitivity analysis techniques on this model. The two motivations for performing sensitivity analysis are to quantify how much individual uncertain parameters are responsible for the model output uncertainty, and to make predictions about what could happen if one or several parameters were to change. Global sensitivity analysis techniques were used based on Gaussian process emulation; the software package GEM-SA was used to calculate the main effects, the main effect index and the total sensitivity index for each parameter and these were compared to local sensitivity analysis results. The results suggest that the system performance is resistant to adverse changes in several parameters at once.

  12. Analysis of fission gas release-to-birth ratio data from the AGR irradiations

    Energy Technology Data Exchange (ETDEWEB)

    Einerson, Jeffrey J., E-mail: jeffrey.einerson@inl.gov; Pham, Binh T.; Scates, Dawn M.; Maki, John T.; Petti, David A.

    2016-09-15

    A series of advanced gas reactor (AGR) irradiation tests is being conducted in the advanced test reactor (ATR) at Idaho National Laboratory (INL) in support of development and qualification of tristructural isotropic (TRISO) fuel used in the High temperature gas-cooled reactor (HTGR). Each AGR test consists of multiple independent capsules containing fuel compacts placed in a graphite cylinder shrouded by a steel shell. These capsules are instrumented with thermocouples (TC) embedded in the graphite enabling temperature control. For AGR-1, the first US irradiation of modern TRISO fuel completed in 2009, there were no particle failures detected. For AGR-2, a few exposed kernels existed in the fuel compacts based upon quality control data. For the AGR-3/4 experiment, particle failures in all capsules were expected because of the use of designed-to-fail (DTF) fuel particles whose kernels are identical to the driver fuel kernels and whose coatings are designed to fail under irradiation. The release-rate-to-birth-rate ratio (R/B) for each of krypton and xenon isotopes is calculated from release rates measured by the germanium detectors used in the AGR fission product monitoring (FPM) system installed downstream from each irradiated capsule. Birth rates are calculated based on the fission power in the experiment and fission product generation models. Thus, this R/B is a measure of the ability of fuel particle coating layers and compact matrix to retain fission gas atoms preventing their release into the sweep gas flow. The major factors that govern gaseous diffusion and release processes are found to be fuel material diffusion coefficient, temperature, and isotopic decay constant. To compare the release behavior among the AGR capsules and historic experiments, the R/B per failed particle is used. HTGR designers use this parameter in their fission product behavior models. For the U.S. TRISO fuel, a regression analysis is performed to establish functional relationships

  13. Using venous blood gas analysis in the assessment of COPD exacerbations: a prospective cohort study.

    Science.gov (United States)

    McKeever, Tricia M; Hearson, Glenn; Housley, Gemma; Reynolds, Catherine; Kinnear, William; Harrison, Tim W; Kelly, Anne-Maree; Shaw, Dominick E

    2016-03-01

    Identifying acute hypercapnic respiratory failure is crucial in the initial management of acute exacerbations of COPD. Guidelines recommend obtaining arterial blood samples but these are more difficult to obtain than venous. We assessed whether blood gas values derived from venous blood could replace arterial at initial assessment. Patients requiring hospital treatment for an exacerbation of COPD had paired arterial and venous samples taken. Bland-Altman analyses were performed to assess agreement between arterial and venous pH, CO2 and HCO3-. The relationship between SpO2 and SaO2 was assessed. The number of attempts and pain scores for each sample were measured. 234 patients were studied. There was good agreement between arterial and venous measures of pH and HC)3- (mean difference 0.03 and -0.04, limits of agreement -0.05 to 0.11 and -2.90 to 2.82, respectively), and between SaO2 and SpO2 (in patients with an SpO2 of >80%). Arterial sampling required more attempts and was more painful than venous (mean pain score 4 (IQR 2-5) and 1 (IQR 0-2), respectively, pblood, and between pulse oximetry and arterial blood gas oxygen saturations. These agreements could allow the initial assessment of COPD exacerbations to be based on venous blood gas analysis and pulse oximetry, simplifying the care pathway and improving the patient experience. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  14. Electron kinetics dependence on gas pressure in laser-induced oxygen plasma experiment: Theoretical analysis

    Science.gov (United States)

    Gamal, Yosr E. E.-D.; Abdellatif, Galila

    2017-08-01

    A study is performed to investigate the dependency of threshold intensity on gas pressure observed in the measurements of the breakdown of molecular oxygen that carried out by Phuoc (2000) [1]. In this experiment, the breakdown was induced by 532 nm laser radiation of pulse width 5.5 ns and spot size of 8.5 μm, in oxygen over a wide pressure range (190-3000 Torr). The analysis aimed to explore the electron kinetic reliance on gas pressure for the separate contribution of each of the gain and loss processes encountered in this study. The investigation is based on an electron cascade model applied previously in Gamal and Omar (2001) [2] and Gaabour et al. (2013) [3]. This model solves numerically a differential equation designates the time evolution of the electron energy distribution, and a set of rate equations that describe the change of excited states population. The numerical examination of the electron energy distribution function and its parameters revealed that photo-ionization of the excited molecules plays a significant role in enhancing the electron density growth rate over the whole tested gas pressure range. This process is off set by diffusion of electrons out of the focal volume in the low-pressure regime. At atmospheric pressure electron, collisional processes dominate and act mainly to populate the excited states. Hence photo-ionization becomes efficient and compete with the encountered loss processes (electron diffusion, vibrational excitation of the ground state molecules as well as two body attachments). At high pressures ( 3000 Torr) three body attachments are found to be the primary cause of losses which deplete the electron density and hence results in the slow decrease of the threshold intensity.

  15. Contributions to the neutronic analysis of a gas-cooled fast reactor

    Energy Technology Data Exchange (ETDEWEB)

    Martin-del-Campo, Cecilia, E-mail: cecilia.martin.del.campo@gmail.com [Departamento de Sistemas Energeticos, Facultad de Ingenieria, Universidad Nacional Autonoma de Mexico, Paseo Cuauhnahuac 8532. Jiutepec, Morelos (Mexico); Reyes-Ramirez, Ricardo, E-mail: ricarera@yahoo.com.mx [Departamento de Sistemas Energeticos, Facultad de Ingenieria, Universidad Nacional Autonoma de Mexico, Paseo Cuauhnahuac 8532. Jiutepec, Morelos (Mexico); Francois, Juan-Luis, E-mail: juan.luis.francois@gmail.com [Departamento de Sistemas Energeticos, Facultad de Ingenieria, Universidad Nacional Autonoma de Mexico, Paseo Cuauhnahuac 8532. Jiutepec, Morelos (Mexico); Reinking-Cejudo, Arturo G., E-mail: reinking@servidor.unam.mx [Departamento de Sistemas Energeticos, Facultad de Ingenieria, Universidad Nacional Autonoma de Mexico, Paseo Cuauhnahuac 8532. Jiutepec, Morelos (Mexico)

    2011-06-15

    Highlights: > Differences on reactivity with MCNPX and TRIPOLI-4 are negligible. > Fuel lattice and core criticality calculations were done. > A higher Doppler coefficient than coolant density coefficient. > Zirconium carbide is a better reflector than silicon carbide. > Adequate active height, radial size and reflector thickness were obtained. - Abstract: In this work the Monte Carlo codes MCNPX and TRIPOLI-4 were used to perform the criticality calculations of the fuel assembly and the core configuration of a gas-cooled fast reactor (GFR) concept, currently in development. The objective is to make contributions to the neutronic analysis of a gas-cooled fast reactor. In this study the fuel assembly is based on a hexagonal lattice of fuel-pins. The materials used are uranium and plutonium carbide as fuel, silicon carbide as cladding, and helium gas as coolant. Criticality calculations were done for a fuel assembly where the axial reflector thickness was varied in order to find the optimal thickness. In order to determine the best material to be used as a reflector, in the reactor core with neutrons of high energy spectrum, criticality calculations were done for three reflector materials: zirconium carbide, silicon carbide and natural uranium. It was found that the zirconium carbide provides the best neutron reflection. Criticality calculations using different active heights were done to determine the optimal height, and the reflector thickness was adjusted. Core criticality calculations were performed with different radius sizes to determine the active radial dimension of the core. A negative temperature coefficient of reactivity was verified for the fuel. The effect on reactivity produced by changes in the coolant density was also evaluated. We present the main neutronic characteristics of a preliminary fuel and core designs for the GFR concept. ENDF-VI cross-sections libraries were used in both the MCNPX and TRIPOLI-4 codes, and we verified that the obtained

  16. Peripartum hysterectomy: an evolving picture.

    LENUS (Irish Health Repository)

    Turner, Michael J

    2012-02-01

    Peripartum hysterectomy (PH) is one of the obstetric catastrophes. Evidence is emerging that the role of PH in modern obstetrics is evolving. Improving management of postpartum hemorrhage and newer surgical techniques should decrease PH for uterine atony. Rising levels of repeat elective cesarean deliveries should decrease PH following uterine scar rupture in labor. Increasing cesarean rates, however, have led to an increase in the number of PHs for morbidly adherent placenta. In the case of uterine atony or rupture where PH is required, a subtotal PH is often sufficient. In the case of pathological placental localization involving the cervix, however, a total hysterectomy is required. Furthermore, the involvement of other pelvic structures may prospectively make the diagnosis difficult and the surgery challenging. If resources permit, PH for pathological placental localization merits a multidisciplinary approach. Despite advances in clinical practice, it is likely that peripartum hysterectomy will be more challenging for obstetricians in the future.

  17. Comparative QRA (Quantitative Risk Analysis) of natural gas distribution pipelines in urban areas; Analise comparativa dos riscos da operacao de linhas de gas natural em areas urbanas

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Luiz Fernando S. de [Energy Solutions South America (Brazil); Cardoso, Cassia de O.; Storch, Rafael [Det Norske Veritas (DNV) (Brazil)

    2008-07-01

    The natural gas pipeline network grows around the world, but its operation inherently imposes a risk to the people living next to pipelines. Due to this, it is necessary to conduct a risk analysis during the environmental licensing in Brazil. Despite the risk analysis methodology is well established, some points of its application for the distribution pipelines are still under discussion. This paper presents a methodology that examines the influences of major projects and operating parameters on the risk calculation of a distribution pipeline accident in urban areas as well as the possible accident scenarios assessment complexity. The impact of some scenarios has been evaluated using a Computational Fluid Dynamics tool. The results indicate that, under certain conditions, the risks from the pipeline operation under operating pressures of 20 bar may be acceptable in location class 3 or even in class 4. These results play a very important role if management decisions on the growth of the distribution of natural gas network in densely populated areas as well as in the improvement of laws to control the activity of distribution of natural gas. (author)

  18. Risk analysis applied to development of a gas field in Santos Basin; Analise de risco aplicada ao desenvolvimento de um campo de gas na Bacia de Santos

    Energy Technology Data Exchange (ETDEWEB)

    Xavier, Alexandre M.; Filoco, Paulo R.; Yamada, Debora T. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2008-07-01

    Decision analysis applied to the development phase of petroleum fields must take into account the risk associated to many kinds of uncertainties. In the transition of the appraisal to the development phases, the importance of risk associated to the production and the recovery factor may increase significantly. The process is complex due to high investments, large number of uncertain variables and strong dependence of the results with the production strategy definition. In E and P, several decisions must be taken considering the risks involved through the appraisal of the uncertainties impact in production of petroleum fields, increase the possibility of success, measuring possible lost and sub-optimized developments identifying new opportunities. In a specific scenario, like gas production, the risk associated to the project becomes larger due to the gas prices compared to oil, the demand, the distribution's structure and the deadlines defined in contracts. The objective of this paper is to show the results of a methodology developed in a detailed study of a risk analysis process in appraisal and development phases (execution and implementation) to one of the biggest gas fields in Brazil (Mexilhao Field) and support reliable future decisions. (author)

  19. A Fisher’s Criterion-Based Linear Discriminant Analysis for Predicting the Critical Values of Coal and Gas Outbursts Using the Initial Gas Flow in a Borehole

    Directory of Open Access Journals (Sweden)

    Xiaowei Li

    2017-01-01

    Full Text Available The risk of coal and gas outbursts can be predicted using a method that is linear and continuous and based on the initial gas flow in the borehole (IGFB; this method is significantly superior to the traditional point prediction method. Acquiring accurate critical values is the key to ensuring accurate predictions. Based on ideal rock cross-cut coal uncovering model, the IGFB measurement device was developed. The present study measured the data of the initial gas flow over 3 min in a 1 m long borehole with a diameter of 42 mm in the laboratory. A total of 48 sets of data were obtained. These data were fuzzy and chaotic. Fisher’s discrimination method was able to transform these spatial data, which were multidimensional due to the factors influencing the IGFB, into a one-dimensional function and determine its critical value. Then, by processing the data into a normal distribution, the critical values of the outbursts were analyzed using linear discriminant analysis with Fisher’s criterion. The weak and strong outbursts had critical values of 36.63 L and 80.85 L, respectively, and the accuracy of the back-discriminant analysis for the weak and strong outbursts was 94.74% and 92.86%, respectively. Eight outburst tests were simulated in the laboratory, the reverse verification accuracy was 100%, and the accuracy of the critical value was verified.

  20. Extreme evolved solar systems (EESS)

    Science.gov (United States)

    Gaensicke, Boris

    2017-08-01

    In just 20 years, we went from not knowing if the solar system is a fluke of Nature to realising that it is totally normal for stars to have planets. More remarkably, it is now clear that planet formation is a robust process, as rich multi-planet systems are found around stars more massive and less massive than the Sun. More recently, planetary systems have been identified in increasingly complex architectures, including circumbinary planets, wide binaries with planets orbiting one or both stellar components, and planets in triple stellar systems.We have also learned that many planetary systems will survive the evolution of their host stars into the white dwarf phase. Small bodies are scattered by unseen planets into the gravitational field of the white dwarfs, tidally disrupt, form dust discs, and eventually accrete onto the white dwarf, where they can be spectroscopically detected. HST/COS has played a critical role in the study these evolved planetary systems, demonstrating that overall the bulk composition of the debris is rocky and resembles in composition the inner the solar system, including evidence for water-rich planetesimals. Past observations of planetary systems at white dwarfs have focused on single stars with main-sequence progenitors of 1.5 to 2.5Msun. Here we propose to take the study of evolved planetary systems into the extremes of parameter ranges to answer questions such as: * How efficient is planet formation around 4-10Msun stars? * What are the metallicities of the progenitors of debris-accreting white dwarfs?* What is the fate of circumbinary planets?* Can star-planet interactions generate magnetic fields in the white dwarf host?

  1. Computational Analysis of Supercritical Carbon Dioxide Gas Turbine for Liquid Metal Cooled Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Wi S.; Suh, Kune Y. [Seoul National University, Seoul (Korea, Republic of)

    2008-10-15

    Energy demands at a remote site are increased as the world energy requirement diversifies so that they should generate power on their own site. A Small Modular Reactor (SMR) becomes a viable option for these sites. Generally, the economic feasibility of a high power reactor is greater than that for SMR. As a result the supercritical fluid driven Brayton cycle is being considered for a power conversion system to increase economic competitiveness of SMR. The Brayton cycle efficiency is much higher than that for the Rankine cycle. Moreover, the components of the Brayton cycle are smaller than Rankine cycle's due to high heat capacity when a supercritical fluid is adopted. A lead (Pb) cooled SMR, BORIS, and a supercritical fluid driven Brayton cycle, MOBIS, are being developed at the Seoul National University (SNU). Dostal et al. have compared some advanced power cycles and proposed the use of a supercritical carbon dioxide (SCO{sub 2}) driven Brayton cycle. According to their suggestion SCO{sub 2} is adopted as a working fluid for MOBIS. The turbo machineries are most important components for the Brayton cycle. The turbo machineries of Brayton cycle consists of a turbine to convert kinetic energy of the fluid into mechanical energy of the shaft, and a compressor to recompress and recover the driving force of the working fluid. Therefore, turbine performance is one of the pivotal factors in increasing the cycle efficiency. In MOBIS a supercritical gas turbine is designed in the Gas Advanced Turbine Operation (GATO) and analyzed in the Turbine Integrated Numerical Analysis (TINA). A three-dimensional (3D) numerical analysis is employed for more detailed design to account for the partial flow which the one-dimensional (1D) analysis cannot consider.

  2. A rapid analysis of plasma/serum ethylene and propylene glycol by headspace gas chromatography.

    Science.gov (United States)

    Ehlers, Alexandra; Morris, Cory; Krasowski, Matthew D

    2013-12-01

    A rapid headspace-gas chromatography (HS-GC) method was developed for the analysis of ethylene glycol and propylene glycol in plasma and serum specimens using 1,3-propanediol as the internal standard. The method employed a single-step derivitization using phenylboronic acid, was linear to 200 mg/dL and had a lower limit of quantitation of 1 mg/dL suitable for clinical analyses. The analytical method described allows for laboratories with HS-GC instrumentation to analyze ethanol, methanol, isopropanol, ethylene glycol, and propylene glycol on a single instrument with rapid switch-over from alcohols to glycols analysis. In addition to the novel HS-GC method, a retrospective analysis of patient specimens containing ethylene glycol and propylene glycol was also described. A total of 36 patients ingested ethylene glycol, including 3 patients who presented with two separate admissions for ethylene glycol toxicity. Laboratory studies on presentation to hospital for these patients showed both osmolal and anion gap in 13 patients, osmolal but not anion gap in 13 patients, anion but not osmolal gap in 8 patients, and 1 patient with neither an osmolal nor anion gap. Acidosis on arterial blood gas was present in 13 cases. Only one fatality was seen; this was a patient with initial serum ethylene glycol concentration of 1282 mg/dL who died on third day of hospitalization. Propylene glycol was common in patients being managed for toxic ingestions, and was often attributed to iatrogenic administration of propylene glycol-containing medications such as activated charcoal and intravenous lorazepam. In six patients, propylene glycol contributed to an abnormally high osmolal gap. The common presence of propylene glycol in hospitalized patients emphasizes the importance of being able to identify both ethylene glycol and propylene glycol by chromatographic methods.

  3. Applications of laser-photoacoustic gas analysis method; Fotoakustisen kaasuanalyysin sovelluksia. Fotoakustiset mittaukset paineistetussa poelyvirtausreaktorissa

    Energy Technology Data Exchange (ETDEWEB)

    Hernberg, R.; Stenberg, J. [Tampere Univ. of Technology (Finland). Lab. of Plasma Technology

    1997-10-01

    Laser induced photoacoustic spectroscopy has been developed in LIEKKI and LIEKKI 2 research programs. The method is intended for In-Situ analysis of gaseous components in hot and reactive environments such as combustion conditions. The method and the instrumentation developed in this project have been calibrated for SO{sub 2}, NO, NO{sub 2}, NH{sub 3}, N{sub 2}O, and H{sub 2}S between 20 and 860 deg C at atmospheric pressure. Calibrations at elevated pressures have been performed for NO{sub 2}, NO, SO{sub 2}, NH{sub 3} and N{sub 2}O. Calibration for OH radical has also been performed. A known concentration of OH was generated by thermally decomposing H{sub 2}O at temperatures between 900 and 1050 deg C. The photoacoustic method has earlier been applied to the chemical analysis of burning CH{sub 4}/HCN/O{sub 2}/N{sub 2} flame at pressures between 1 and 6 bar. The formation of NO and NH{sub 3} measured in post-flame conditions. The relative concentration of OH in the reactive zone of the flame was measured between 1 and 6 bar pressures. The method was also applied to measurements in circulating fluidized bed (CFB). Time resolved gas concentrations were measured at three different heights above the air distributor with a specialized probe. In this project the photoacoustic method is applied in studies regarding the effect of chlorine (Cl) on combustion chemistry. The second goal of this project is to make In-Situ measurements of the formation of NO{sub 2} in combustion. The formation of NO{sub 2} increases strongly at elevated pressures. Due to the instability of NO{sub 2} the analysis is prone to errors with conventional gas sampling probes

  4. Selection of High Performance Alloy for Gas Turbine Blade Using Multiphysics Analysis

    Directory of Open Access Journals (Sweden)

    H Khawaja

    2016-09-01

    Full Text Available With the extensive increase in the utilization of energy resources in the modern era, the need of energy extraction from various resources has pronounced in recent years. Thus comprehensive efforts have been made around the globe in the technological development of turbo machines where means of energy extraction is energized fluids. This development led the aviation industry to power boost due to better performing engines. Meanwhile, the structural conformability requirements relative to the functional requirements have also increased with the advent of newer, better performing materials. Thus there is a need to study the material behavior and its usage with the idea of selecting the best possible material for its application. In this work a gas turbine blade of a small turbofan engine, where geometry and aerodynamic data was available, was analyzed for its structural behavior in the proposed mission envelope, where the engine turbine is subjected to high thermal, inertial and aerodynamic loads. Multiphysics Finite Element (FE linear stress analysis was carried out on the turbine blade. The results revealed the upper limit of Ultimate Tensile Strength (UTS for the blade. Based on the limiting factor, high performance alloys were selected from the literature. The two most recommended alloy categories for gas turbine blades are NIMONIC and INCONEL from where total of 21 types of INCONEL alloys and 12 of NIMONIC alloys, available on commercial bases, were analyzed individually to meet the structural requirements. After applying selection criteria, four alloys were finalized from NIMONIC and INCONEL alloys for further analysis. On the basis of stress-strain behavior of finalized alloys, the Multiphysics FE nonlinear stress analysis was then carried out for the selection of the individual alloy by imposing a restriction of Ultimate Factor of Safety (UFOS of 1.33 and yield strength. Final selection is made keeping in view other factors

  5. Sales analysis as a basis for optimising gas procurement; Absatzanalyse als Grundlage optimierter Gasbeschaffung

    Energy Technology Data Exchange (ETDEWEB)

    Jungblut, Ralf [RWE Vertrieb AG, Dortmund (Germany). Produktmanagement, Marketing und Datenmanagement

    2012-01-15

    German energy suppliers are finding themselves in an increasingly difficult situation in the gas market. With the natural gas glut subsiding and global demand picking up, gas prices are expected to rise over the long term. Counter to the global trend, gas demand in Germany is expected to decrease. Furthermore, short-term fluctuations in economic activity with a potential for impacting on the demand for and price level of natural gas may pose significant economic risks. A detailed knowledge of one's own sales portfolio is therefore extremely important when it comes to gas procurement.

  6. Peak alignment and robust principal component analysis of gas chromatograms of fatty acid methyl esters and volatiles

    DEFF Research Database (Denmark)

    Frosch, Stina; Jørgensen, Bo

    2007-01-01

    Gas chromatograms of fatty acid methyl esters and of volatile lipid oxidation products from fish lipid extracts are analyzed by multivariate data analysis [principal component analysis (PCA)]. Peak alignment is necessary in order to include all sampled points of the chromatograms in the data set....

  7. FTIR spectra and normal-mode analysis of a tetranuclear Manganese adamantane-like complex in two electrochemically prepared oxidation states: Relevance to the oxygen-evolving complex of Photosystem II

    Energy Technology Data Exchange (ETDEWEB)

    Visser, Hendrik; Dube, Christopher E.; Armstrong, William H.; Sauer, Kenneth; Yachandra, Vittal K.

    2002-03-19

    The IR spectra and normal-mode analysis of the adamantane-like compound [Mn4O6(bpea)4]n+ in two oxidation states, MnIV4 and MnIIIMnIV3, that are relevant to the oxygen-evolving complex of photosystem II are presented. Mn-O vibrational modes are identified with isotopic exchange, 16O->18O, of the mono-(mu)-oxo bridging atoms in the complex. IR spectra of the MnIIIMnIV3 species are obtained by electrochemical reduction of the MnIV4 species using a spectroelectrochemical cell, based on attenuated total reflection [Visser et al. Anal Chem 2001, 73, 4374-4378]. A novel method of subtraction is used to reduce background contributions from solvent and ligand modes, and the difference and double-difference spectra are used in identifying Mn-O bridging modes that are sensitive to oxidation state change. Two strong IR bands are observed for the MnIV4 species at 745 and 707 cm-1 and a weaker band at 510 cm-1. Upon reduction, the MnIIIMnIV3 species exhibits two strong IR bands at 745 and 680 cm-1, and several weaker bands are observed in the 510 - 425 cm-1 range. A normal mode analysis is performed to assign all the relevant bridging modes in the oxidized MnIV4 and reduced MnIIIMnIV3 species. The calculated force constants for the MnIV4 species are = 3.15 mdynAngstrom, = 0.55 mdyn/Angstrom, and = 0.20 mdyn/Angstrom. The force constants for the MnIIIMnIV3 species are = 3.10 mdyn/Angstrom, = 2.45 mdyn/Angstrom, = 0.40, and = 0.15 mdyn/Angstrom. This study provides insights for the identification of Mn-O modes in the IR spectra of the photosynthetic oxygen-evolving complex during its catalytic cycle.

  8. Thermal hydrodynamic analysis of a countercurrent gas centrifuge; Analise termo hidrodinamica de uma centrifuga a contracorrente

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Delvonei Alves de

    1999-07-01

    The influence of the thermal countercurrent on the separative performance of countercurrent centrifuges is treated in this work. The methodology used consists in modeling the gas flow inside the rotor under thermal boundary conditions supplied by the structural thermal model. The gas flow model, also called hydrodynamical model, is based on the Finite Volume Method for cylindrical geometry with azimuthal symmetry. The structural thermal model is based on the Nodal Method and take into account simultaneously, the conduction convection and radiation phenomena. The procedure adopted for this study consisted in the definition of the operational and geometric conditions of a centrifuge which was used as a pattern to the accomplished analysis. This configuration, called 'Standard Centrifuge', was used for the accomplishment of several simulations where the importance of the realistic boundary thermal conditions for the numerical evaluation of the centrifuge separative capacity was evidenced. A selective alteration for the optical properties based on simple engineering procedures was proposed. An improvement of 5% was obtained with this alteration. (author)

  9. Thermodynamic Analysis of Simple Gas Turbine Cycle with Multiple Regression Modelling and Optimization

    Directory of Open Access Journals (Sweden)

    Abdul Ghafoor Memon

    2014-03-01

    Full Text Available In this study, thermodynamic and statistical analyses were performed on a gas turbine system, to assess the impact of some important operating parameters like CIT (Compressor Inlet Temperature, PR (Pressure Ratio and TIT (Turbine Inlet Temperature on its performance characteristics such as net power output, energy efficiency, exergy efficiency and fuel consumption. Each performance characteristic was enunciated as a function of operating parameters, followed by a parametric study and optimization. The results showed that the performance characteristics increase with an increase in the TIT and a decrease in the CIT, except fuel consumption which behaves oppositely. The net power output and efficiencies increase with the PR up to certain initial values and then start to decrease, whereas the fuel consumption always decreases with an increase in the PR. The results of exergy analysis showed the combustion chamber as a major contributor to the exergy destruction, followed by stack gas. Subsequently, multiple regression models were developed to correlate each of the response variables (performance characteristic with the predictor variables (operating parameters. The regression model equations showed a significant statistical relationship between the predictor and response variables.

  10. Thermochemical Analysis of Gas-Cooled Reactor Fuels Containing Am and Pu Oxides

    Energy Technology Data Exchange (ETDEWEB)

    Lindemer, T.B.

    2002-09-05

    Literature values and estimated data for the thermodynamics of the actinide oxides and fission products are applied to explain the chemical behavior in gas-cooled-reactor fuels. Emphasis is placed on the Am-O-C and Pu-O-C systems and the data are used to plot the oxygen chemical potential versus temperature of solid-solid and solid-gas equilibria. These results help explain observations of vaporization in Am oxides, nitrides, and carbides and provide guidance for the ceramic processing of the fuels. The thermodynamic analysis is then extended to the fission product systems and the Si-C-O system. Existing data on oxygen release (primarily as CO) as a function of burnup in the thoria-urania fuel system is reviewed and compared to values calculated from thermodynamic data. The calculations of oxygen release are then extended to the plutonia and americia fuels. Use of ZrC not only as a particle coating that may be more resistant to corrosion by Pd and other noble-metal fission products, but also as a means to getter oxygen released by fission is discussed.

  11. Well-to-Wheels Analysis of Compressed Natural Gas and Ethanol from Municipal Solid Waste

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Uisung [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division; Han, Jeongwoo [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division; Wang, Michael [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division

    2016-10-01

    The amount of municipal solid waste (MSW) generated in the United States was estimated at 254 million wet tons in 2013, and around half of that generated waste was landfilled. There is a huge potential in recovering energy from that waste, since around 60% of landfilled material is biomass-derived waste that has high energy content. In addition, diverting waste for fuel production avoids huge fugitive emissions from landfills, especially uncontrolled CH4 emissions, which are the third largest anthropogenic CH4 source in the United States. Lifecycle analysis (LCA) is typically used to evaluate the environmental impact of alternative fuel production pathways. LCA of transportation fuels is called well-to-wheels (WTW) and covers all stages of the fuel production pathways, from feedstock recovery (well) to vehicle operation (wheels). In this study, the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET®) model developed by Argonne National Laboratory is used to evaluate WTW greenhouse gas (GHG) emissions and fossil fuel consumption of waste-derived fuels. Two waste-to-energy (WTE) pathways have been evaluated – one for compressed natural gas (CNG) production using food waste via anaerobic digestion, and the other for ethanol production from yard trimmings via fermentation processes. Because the fuel production pathways displace current waste management practices (i.e., landfilling waste), we use a marginal approach that considers only the differences in emissions between the counterfactual case and the alternative fuel production case.

  12. On the exergy disaggregation for thermoeconomic analysis of a gas turbine cogeneration system

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Jose Joaquim Conceicao Soares [Federal University of Espirito Santo - UFES/DEM, Goiabeiras, Vitoria, ES (Brazil); Silva, Julio Augusto Mendes da [University of Sao Paulo, Sao Paulo, SP (Brazil)], e-mail: jams@usp.br; Palacio, Jose Carlos Escobar [Federal University of Itajuba, Itajuba, MG (Brazil); Moreira, Hugo Lima [Federal Rural University of Amazonia, Belem, PA (Brazil)

    2010-07-01

    Most analysts agree that exergy, instead of enthalpy only, is the most adequate thermodynamic quantity to associate with cost. Therefore, all thermoeconomic methodologies use the exergy to define productive structure. Sometimes, under a thermoeconomic analysis point of view, it is necessary to consider a mass or an energy flow rate consisting of several exergy components, for example thermal, mechanical and chemical components. Most analysts agree that by considering separate exergy forms the accuracy of the results is improved in thermoeconomics. However, these analysts recognize that the disaggregation of physical exergy might not be always reasonably because of the increase in the computational efforts. Thus, the main questions are: Is this improvement often marginal? Is exergy disaggregation necessary for extracting the main conclusions? This paper aims at answering these questions for the case of external fuel (natural gas) exergy allocation to the two final products (heat and power) of a gas turbine cogeneration system, by applying four different productive structures based on different kind and level of physical exergy disaggregation. The paper also shown that the model that uses enthalpy together with sintropy presents the closest result in relation to the total disaggregated model, showing the rationality of this methodology that intrinsically allocate the residues to the components of the cycle using the entropy variation in each component as a weighting factor. (author)

  13. Process analysis of CO{sub 2} capture from flue gas using carbonation/calcination cycles

    Energy Technology Data Exchange (ETDEWEB)

    Li, Z.S.; Cai, N.S.; Croiset, E. [Tsinghua University, Beijing (China). Dept. for Thermal Engineering

    2008-07-15

    Process analysis of CO{sub 2} capture from flue gas using Ca-based carbonation/calcination cycles is presented here. A carbonation/calcination system is composed essentially of two reactors (an absorber and a regenerator) with Ca-based sorbent circulating between the two reactors (assumed here as fluidized beds). CO{sub 2} is, therefore, transferred from the absorber to the regenerator. Because of the endothermicity of the calcination reaction, a certain amount of coal is burned with pure oxygen in the regenerator. Detailed mass balance, heat balance and cost of electricity and CO{sub 2} mitigation for the carbonation/calcination cycles with three Ca-based sorbents in dual fluidized beds were calculated and analyzed to study the effect of the Ca-based sorbent activity decay on CO{sub 2} capture from flue gas. The three sorbents considered were: limestone, dolomite and CaO/Ca{sub 12}Al{sub 14}O{sub 33} (75/25 wt %) sorbent. All results, including the amount of coal and oxygen required, are presented with respect to the difference in calcium oxide conversion between the absorber and the regenerator, which is an important design parameter. Finally, costs of electricity and CO{sub 2} mitigation costs using carbonation/calcination cycles for the three sorbents were estimated. The results indicate that the economics of the carbonation/calcination process compare favorably with competing technologies for capturing CO{sub 2}.

  14. Uncertainty analysis of a coupled ecosystem response model simulating greenhouse gas fluxes from a temperate grassland

    Science.gov (United States)

    Liebermann, Ralf; Kraft, Philipp; Houska, Tobias; Breuer, Lutz; Müller, Christoph; Kraus, David; Haas, Edwin; Klatt, Steffen

    2015-04-01

    Among anthropogenic greenhouse gas emissions, CO2 is the dominant driver of global climate change. Next to its direct impact on the radiation budget, it also affects the climate system by triggering feedback mechanisms in terrestrial ecosystems. Such mechanisms - like stimulated photosynthesis, increased root exudations and reduced stomatal transpiration - influence both the input and the turnover of carbon and nitrogen compounds in the soil. The stabilization and decomposition of these compounds determines how increasing CO2 concentrations change the terrestrial trace gas emissions, especially CO2, N2O and CH4. To assess the potential reaction of terrestrial greenhouse gas emissions to rising tropospheric CO2 concentration, we make use of a comprehensive ecosystem model integrating known processes and fluxes of the carbon-nitrogen cycle in soil, vegetation and water. We apply a state-of-the-art ecosystem model with measurements from a long term field experiment of CO2 enrichment. The model - a grassland realization of LandscapeDNDC - simulates soil chemistry coupled with plant physiology, microclimate and hydrology. The data - comprising biomass, greenhouse gas emissions, management practices and soil properties - has been attained from a FACE (Free Air Carbon dioxide Enrichment) experiment running since 1997 on a temperate grassland in Giessen, Germany. Management and soil data, together with weather records, are used to drive the model, while cut biomass as well as CO2 and N2O emissions are used for calibration and validation. Starting with control data from installations without CO2 enhancement, we begin with a GLUE (General Likelihood Uncertainty Estimation) assessment using Latin Hypercube to reduce the range of the model parameters. This is followed by a detailed sensitivity analysis, the application of DREAM-ZS for model calibration, and an estimation of the effect of input uncertainty on the simulation results. Since first results indicate problems with

  15. Quantitative analysis of dimethyl titanocene by iodometric titration, gas chromatography and NMR.

    Science.gov (United States)

    Vailaya, A; Wang, T; Chen, Y; Huffman, M

    2001-06-01

    In this study we report the use of an automated iodometric titration method and a novel gas chromatography (GC) method for the quantitative analysis of dimethyl titanocene (DMT), a key raw material in drug synthesis. Both approaches are based on the reaction of DMT in toluene or tetrahydrofuran solutions with iodine. In the case of iodometric titration, excess iodine is titrated with a standardized aqueous sodium thiosulfate solution to a potentiometric end-point for the determination of DMT concentration. Alternatively, GC is employed to measure the concentration of iodomethane, a product of the reaction between DMT and iodine, in order to determine the concentration of DMT in the solution. Excellent agreement between iodometric titration, GC and NMR results using several DMT samples confirms the accuracy of the two methods and strongly supports the use of either method as a replacement to the expensive NMR for quantitative DMT analysis. The relatively few sources of error associated with the two methods, their ubiquitous nature and ease of application in routine analysis make them the analytical methods of choice, among all. Both methods have been validated according to ICH requirements. The use of iodometric titration method for DMT analysis is demonstrated with a couple of applications.

  16. Nonstandard Analysis and Shock Wave Jump Conditions in a One-Dimensional Compressible Gas

    Energy Technology Data Exchange (ETDEWEB)

    Roy S. Baty, F. Farassat, John A. Hargreaves

    2007-05-25

    Nonstandard analysis is a relatively new area of mathematics in which infinitesimal numbers can be defined and manipulated rigorously like real numbers. This report presents a fairly comprehensive tutorial on nonstandard analysis for physicists and engineers with many examples applicable to generalized functions. To demonstrate the power of the subject, the problem of shock wave jump conditions is studied for a one-dimensional compressible gas. It is assumed that the shock thickness occurs on an infinitesimal interval and the jump functions in the thermodynamic and fluid dynamic parameters occur smoothly across this interval. To use conservations laws, smooth pre-distributions of the Dirac delta measure are applied whose supports are contained within the shock thickness. Furthermore, smooth pre-distributions of the Heaviside function are applied which vary from zero to one across the shock wave. It is shown that if the equations of motion are expressed in nonconservative form then the relationships between the jump functions for the flow parameters may be found unambiguously. The analysis yields the classical Rankine-Hugoniot jump conditions for an inviscid shock wave. Moreover, non-monotonic entropy jump conditions are obtained for both inviscid and viscous flows. The report shows that products of generalized functions may be defined consistently using nonstandard analysis; however, physically meaningful products of generalized functions must be determined from the physics of the problem and not the mathematical form of the governing equations.

  17. Financial Risk Factor Analysis for Facility Gas Leakages of H2 and NG

    Directory of Open Access Journals (Sweden)

    In-Bok Lee

    2016-09-01

    Full Text Available Fuel cells may be the key to a more environmentally-friendly future because they emit low carbon dioxide per unit of energy supplied. However, little work has investigated the potential financial risks pertaining to fuel cell systems. Often used in the analysis of the safety of systems involving flammable or hazardous materials, risk factor analysis has recently been used to analyze the potential financial losses that may occur from industrial hazards. Therefore, this work undertakes a financial risk factor analysis to determine the costs of leakages of hydrogen and natural gas, which are used in fuel cell systems. Total leakage was calculated from an analysis of several leakage rates and modes. The impact of applying appropriate detection and prevention systems was also investigated. The findings were then used to analyze the consequences for various sections of the system and to calculate the overall cost based on facility outage or damage, and the cost of taking safety precautions. This provides a basis for comparison among proposed potential reactionary measures.

  18. Lifecycle analysis of renewable natural gas and hydrocarbon fuels from wastewater treatment plants’ sludge

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Uisung [Argonne National Lab. (ANL), Argonne, IL (United States); Han, Jeongwoo [Argonne National Lab. (ANL), Argonne, IL (United States); Urgun Demirtas, Meltem [Argonne National Lab. (ANL), Argonne, IL (United States); Wang, Michael [Argonne National Lab. (ANL), Argonne, IL (United States); Tao, Ling [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-09-01

    Wastewater treatment plants (WWTPs) produce sludge as a byproduct when they treat wastewater. In the United States, over 8 million dry tons of sludge are produced annually just from publicly owned WWTPs. Sludge is commonly treated in anaerobic digesters, which generate biogas; the biogas is then largely flared to reduce emissions of methane, a potent greenhouse gas. Because sludge is quite homogeneous and has a high energy content, it is a good potential feedstock for other conversion processes that make biofuels, bioproducts, and power. For example, biogas from anaerobic digesters can be used to generate renewable natural gas (RNG), which can be further processed to produce compressed natural gas (CNG) and liquefied natural gas (LNG). Sludge can be directly converted into hydrocarbon liquid fuels via thermochemical processes such as hydrothermal liquefaction (HTL). Currently, the environmental impacts of converting sludge into energy are largely unknown, and only a few studies have focused on the environmental impacts of RNG produced from existing anaerobic digesters. As biofuels from sludge generate high interest, however, existing anaerobic digesters could be upgraded to technology with more economic potential and more environmental benefits. The environmental impacts of using a different anaerobic digestion (AD) technology to convert sludge into energy have yet to be analyzed. In addition, no studies are available about the direct conversion of sludge into liquid fuels. In order to estimate the energy consumption and greenhouse gas (GHG) emissions impacts of these alternative pathways (sludge-to-RNG and sludge-to-liquid), this study performed a lifecycle analysis (LCA) using the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET®) model. The energy uses and GHG emissions associated with the RNG and hydrocarbon liquid are analyzed relative to the current typical sludge management case, which consists of a single-stage mesophilic

  19. Analysis of the dynamic characteristics of gas chamber in rotary hammer

    National Research Council Canada - National Science Library

    YAN, Shiwei; HUANG, Shangyu; ZOU, Fangli

    2016-01-01

    Rotary hammer is a high-frequency impact machine with a complicated gas chamber. The design parameters of the gas chamber are dominating to impact energy output and impact efficiency of a rotary hammer...

  20. ANALYSIS OF DEPENDENCE BETWEEN CAPITAL EXPENDUTURES OF CONSTRUCTION WORKS AND GAS DISTRIBUTION PIPELINE DIAMETER

    Directory of Open Access Journals (Sweden)

    Tabunshchikov Yuriy Andreevich

    2012-10-01

    The research also contemplates the structure of expenses associated with the piping of gas distribution networks. Mathematical equations have been derived to perform sufficiently accurate calculations of costs of construction of various types and various lengths of gas pipelines.