WorldWideScience

Sample records for volume gas cell

  1. Observations from using models to fit the gas production of varying volume test cells and landfills.

    Science.gov (United States)

    Lamborn, Julia

    2012-12-01

    Landfill operators are looking for more accurate models to predict waste degradation and landfill gas production. The simple microbial growth and decay models, whilst being easy to use, have been shown to be inaccurate. Many of the newer and more complex (component) models are highly parameter hungry and many of the required parameters have not been collected or measured at full-scale landfills. This paper compares the results of using different models (LANDGEM, HBM, and two Monod models developed by the author) to fit the gas production of laboratory scale, field test cell and full-scale landfills and discusses some observations that can be made regarding the scalability of gas generation rates. The comparison of these results show that the fast degradation rate that occurs at laboratory scale is not replicated at field-test cell and full-scale landfills. At small scale, all the models predict a slower rate of gas generation than actually occurs. At field test cell and full-scale a number of models predict a faster gas generation than actually occurs. Areas for future work have been identified, which include investigations into the capture efficiency of gas extraction systems and into the parameter sensitivity and identification of the critical parameters for field-test cell and full-scale landfill predication.

  2. Versatile, ultra-low sample volume gas analyzer using a rapid, broad-tuning ECQCL and a hollow fiber gas cell

    Energy Technology Data Exchange (ETDEWEB)

    Kriesel, Jason M.; Makarem, Camille N.; Phillips, Mark C.; Moran, James J.; Coleman, Max; Christensen, Lance; Kelly, James F.

    2017-05-05

    We describe a versatile mid-infrared (Mid-IR) spectroscopy system developed to measure the concentration of a wide range of gases with an ultra-low sample size. The system combines a rapidly-swept external cavity quantum cascade laser (ECQCL) with a hollow fiber gas cell. The ECQCL has sufficient spectral resolution and reproducibility to measure gases with narrow features (e.g., water, methane, ammonia, etc.), and also the spectral tuning range needed to measure volatile organic compounds (VOCs), (e.g., aldehydes, ketones, hydrocarbons), sulfur compounds, chlorine compounds, etc. The hollow fiber is a capillary tube having an internal reflective coating optimized for transmitting the Mid-IR laser beam to a detector. Sample gas introduced into the fiber (e.g., internal volume = 0.6 ml) interacts strongly with the laser beam, and despite relatively modest path lengths (e.g., L ~ 3 m), the requisite quantity of sample needed for sensitive measurements can be significantly less than what is required using conventional IR laser spectroscopy systems. Example measurements are presented including quantification of VOCs relevant for human breath analysis with a sensitivity of ~2 picomoles at a 1 Hz data rate.

  3. Natural gas annual 1994: Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-11-01

    The Natural Gas Annual provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. This report, Volume 2, presents historical data fro the Nation from 1930 to 1994, and by State from 1967 to 1994.

  4. Gas volume contents within a container, smart volume instrument

    Science.gov (United States)

    Kelley, Anthony R. (Inventor); Van Buskirk, Paul D. (Inventor)

    2008-01-01

    A method for determining the volume of an incompressible gas in a system including incompressible substances in a zero-gravity environment. The method includes inducing a volumetric displacement within a container and measuring the resulting pressure change. From this data, the liquid level can be determined.

  5. Natural gas annual 1992: Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    1993-11-22

    This document provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and education institutions. The 1992 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production top its end use. Tables summarizing natural gas supply and disposition from 1988 to 1992 are given for each Census Division and each State. Annual historical data are shown at the national level. Volume 2 of this report presents State-level historical data.

  6. Thermodynamics of the low density excluded volume hadron gas

    CERN Document Server

    Zalewski, Kacper

    2015-01-01

    We discuss the influence of the excluded volume of hadrons on macroscopic variables and thermal parameters of the hadron gas at finite temperature and chemical potential in the low density approximation. Based solely on elementary thermodynamics we show that when the excluded volume grows at constant temperature, pressure, and number of particles, the overall volume increases just as much as the excluded volume, while the entropy and energy remain unchanged. The growth of the chemical potentials is equal to the work needed to create the respective excluded volumes. Consequently, the bulk density functions of a gas with excluded volume are expressed by the corresponding variables in a system of point particles with the shifted chemical potentials. Our results are fully consistent with the previous findings obtained upon applications of more advanced methods of statistical physics. A validity limit for the low density approximation is derived and discussed in the context of the hadron gas created in heavy ion c...

  7. North American Natural Gas Markets. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    1989-02-01

    This report summarizes die research by an Energy Modeling Forum working group on the evolution of the North American natural gas markets between now and 2010. The group`s findings are based partly on the results of a set of economic models of the natural gas industry that were run for four scenarios representing significantly different conditions: two oil price scenarios (upper and lower), a smaller total US resource base (low US resource case), and increased potential gas demand for electric generation (high US demand case). Several issues, such as the direction of regulatory policy and the size of the gas resource base, were analyzed separately without the use of models.

  8. Coal liquefaction and gas conversion: Proceedings. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-31

    Volume I contains papers presented at the following sessions: AR-Coal Liquefaction; Gas to Liquids; and Direct Liquefaction. Selected papers have been processed separately for inclusion in the Energy Science and Technology Database.

  9. Ion Channels Involved in Cell Volume Regulation

    DEFF Research Database (Denmark)

    Hoffmann, Else Kay

    2011-01-01

    This mini review outlines studies of cell volume regulation in two closely related mammalian cell lines: nonadherent Ehrlich ascites tumour cells (EATC) and adherent Ehrlich Lettre ascites (ELA) cells. Focus is on the regulatory volume decrease (RVD) that occurs after cell swelling, the volume...

  10. North American Natural Gas Markets: Selected technical studies. Volume 3

    Energy Technology Data Exchange (ETDEWEB)

    Huntington, H.G.; Schuler, G.E. [eds.

    1989-04-01

    The Energy Modeling Forum (EMF) was established in 1976 at Stanford University to provide a structural framework within which energy experts, analysts, and policymakers could meet to improve their understanding of critical energy problems. The ninth EMF study, North American Natural Gas Markets, was conducted by a working group comprised of leading natural gas analysts and decision-makers from government, private companies, universities, and research and consulting organizations. The EMF 9 working group met five times from October 1986 through June 1988 to discuss key issues and analyze natural gas markets. This third volume includes technical papers that support many of the conclusions discussed in the EMF 9 summary report (Volume 1) and full working group report (Volume 2). These papers discuss the results from the individual models as well as some nonmodeling analysis related to US natural gas imports and industrial natural gas demand. Individual papers have been processed separately for inclusion in the Energy Science and Technology Database.

  11. Computed Tomography Colonography Technique: The Role of Intracolonic Gas Volume

    Directory of Open Access Journals (Sweden)

    Patrick D. McLaughlin

    2013-01-01

    Full Text Available Introduction. Poor distention decreases the sensitivity and specificity of CTC. The total volume of gas administered will vary according to many factors. We aim to determine the relationship between the volume of retained gas at the time of image acquisition and colonic distention and specifically the presence of collapsed bowel segments at CTC. Materials and Methods. All patients who underwent CTC over a 12-month period at a single institution were included in the study. Colonic luminal distention was objectively scored by 2 radiologists using an established 4-point scale. Quantitative analysis of the volume of retained gas at the time of image acquisition was conducted using the threshold 3D region growing function of OsiriX. Results. 108 patients were included for volumetric analysis. Mean retained gas volume was 3.3 L. 35% (38/108 of patients had at least one collapsed colonic segment. Significantly lower gas volumes were observed in the patients with collapsed colonic segments when compared with those with fully distended colons 2.6 L versus 3.5 L (P=0.031. Retained volumes were significantly higher for the 78% of patients with ileocecal reflux at 3.4 L versus 2.6 L without ileocecal reflux (P=0.014. Conclusion. Estimation of intraluminal gas volume at CTC is feasible using image segmentation and thresholding tools. An average of 3.5 L of retained gas was found in diagnostically adequate CTC studies with significantly lower mean gas volume observed in patients with collapsed colonic segments.

  12. Safe Reduction of Blood Volume in the Blood Gas Laboratory.

    Science.gov (United States)

    Jensen, Phillip R; Markewitz, Boaz A

    2016-11-01

    Phlebotomy is a significant cause of iatrogenic anemia in the critical care environment. It is estimated that one-third of all transfusions of packed red blood cells in intensive care units (ICU) result from phlebotomy. The aims of this study were to determine if utilizing the 1mL blood gas syringe for an adult population would impact the rate at which specimens were acceptable for testing and result reporting based on lab specimen rejection criteria; and to compare blood utilization between the 2 different syringes. This study was conducted in 1 of the adult ICUs at the University of Utah Hospital. Over a baseline period a standard adult 3 mL blood gas syringe was utilized. Subsequently the standard adult syringe was replaced by a 1 mL syringe produced by the same manufacturer with the same heparin concentration. The change to the 1 mL syringe had no effect on specimen integrity in regards to laboratory's ability to process the specimen. With use of the 1 mL syringe there was a 60% reduction in the volume of blood drawn compared with the baseline period. Standardizing the 1 mL syringe for Blood Gas Laboratory tests will reduce patient blood loss without appreciably affecting specimen rejection relative to current rates. © American Society for Clinical Pathology, 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. Determination of turnover and cushion gas volume of a prospected gas storage reservoir under uncertainty

    Energy Technology Data Exchange (ETDEWEB)

    Gubik, A. [RAG-AG Wien (Austria); Baffoe, J.; Schulze-Riegert, R. [SPT Group GmbH, Hamburg (Germany)

    2013-08-01

    Gas storages define a key contribution for building a reliable gas supply chain from production to consumers. In a competitive gas market with short reaction times to seasonal and other gas injection and extraction requirements, gas storages also receive a strong focus on availability and precise prediction estimates for future operation scenarios. Reservoir management workflows are increasingly built on reservoir simulation support for optimizing production schemes and estimating the impact of subsurface uncertainties on field development scenarios. Simulation models for gas storages are calibrated to geological data and accurate reproduction of historical production data are defined as a prerequisite for reliable production and performance forecasts. The underlying model validation process is called history matching, which potentially generates alternative simulation models due to prevailing geological uncertainties. In the past, a single basecase reference model was used to predict production capacities of a gas storage. The working gas volume was precisely defined over a contracted plateau delivery and the required cushion gas volume maintains the reservoir pressure during the operation. Cushion and working gas Volume are strongly dependent on reservoir parameters. In this work an existing depleted gas reservoir and the operation target as a gas storage is described. Key input data to the reservoir model description and simulation is reviewed including production history and geological uncertainties based on large well spacing, limited core and well data and a limited seismic resolution. Target delivery scenarios of the prospected gas storage are evaluated under uncertainty. As one key objective, optimal working gas and cushion gas volumes are described in a probabilistic context reflecting geological uncertainties. Several work steps are defined and included in an integrated workflow design. Equiprobable geological models are generated and evaluated based on

  14. Enhanced recovery of unconventional gas. Executive summary. Volume I (of 3 volumes)

    Energy Technology Data Exchange (ETDEWEB)

    Kuuskraa, V. A.; Brashear, J. P.; Doscher, T. M.; Elkins, L. E.

    1978-10-01

    R and D efforts in enhanced gas recovery of near-conventional and unconventional gas sources are needed in order to augment domestic supplies. Unconventional gas sources could provide 200 to 220 Tcf of additional gas supply, if a combination of economic incentives and publicly sponsored R and D is used, and as much as 2 to 8 Tcf could be delivered per year by 1990. This volume comprises three parts discussing the public policy issues, proposed research strategy in enhanced gas recovery, and methodology. 14 figures. (DLC)

  15. Gas Density and the Volume Schmidt Law for Spiral Galaxies

    CERN Document Server

    Abramova, O V

    2007-01-01

    The thickness of the equilibrium isothermal gaseous layers and their volume densities \\rho_{gas}(R) in the disc midplane are calculated for 7 spiral galaxies (including our Galaxy) in the frame of self-consistent axisymmetric model. Local velocity dispersions of stellar discs were assumed to be close to marginal values necessary for the discs to be in a stable equilibrium state. Under this condition the stellar discs of at least 5 of 7 galaxies reveal a flaring. Their volume densities decrease with R faster than \\rho_{gas}, and, as a result, the gas dominates by the density at the disc periphery. Comparison of the azimuthally averaged star formation rate SFR with the gas density shows that there is no universal Schmidt law SFR \\rho_{gas}^n, common to all galaxies. Nevertheless, SFR in different galaxies reveals better correlation with the volume gas density than with the column one. Parameter n in the Schmidt law SFR \\rho_{gas}^n, formally calculated by the least square method, lies within 0.8-2.4 range and i...

  16. The cryogenic gas stopping cell of SHIPTRAP

    Energy Technology Data Exchange (ETDEWEB)

    Droese, C., E-mail: christian.droese1@uni-greifswald.de [Ernst-Moritz-Arndt-Universität, Felix-Hausdorff-Straße 6, 17489 Greifswald (Germany); Helmholtz-Institut Mainz, Johannes Gutenberg-Universität, 55099 Mainz (Germany); Eliseev, S.; Blaum, K. [Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Block, M.; Herfurth, F. [GSI Helmholtzzentrum für Schwerionenforschung, Planckstraße 1, 64291 Darmstadt (Germany); Laatiaoui, M. [Helmholtz-Institut Mainz, Johannes Gutenberg-Universität, 55099 Mainz (Germany); Lautenschläger, F. [Technische Universität Darmstadt, Pankratiusstraße 2, 64289 Darmstadt (Germany); Minaya Ramirez, E. [Helmholtz-Institut Mainz, Johannes Gutenberg-Universität, 55099 Mainz (Germany); Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Schweikhard, L. [Ernst-Moritz-Arndt-Universität, Felix-Hausdorff-Straße 6, 17489 Greifswald (Germany); Simon, V.V. [Helmholtz-Institut Mainz, Johannes Gutenberg-Universität, 55099 Mainz (Germany); Thirolf, P.G. [Ludwig Maximilians-Universität München, Am Coulombwall 1, 85748 Garching (Germany)

    2014-11-01

    The overall efficiency of the Penning-trap mass spectrometer SHIPTRAP at GSI Darmstadt, employed for high-precision mass measurements of exotic nuclei in the mass region above fermium, is presently mostly limited by the stopping and extraction of fusion-evaporation products in the SHIPTRAP gas cell. To overcome this limitation a second-generation gas cell with increased stopping volume was designed. In addition, its operation at cryogenic temperatures leads to a higher gas density at a given pressure and an improved cleanliness of the helium buffer gas. Here, the results of experiments with a {sup 219}Rn recoil ion source are presented. An extraction efficiency of 74(3)% was obtained, a significant increase compared to the extraction efficiency of 30% of the present gas stopping cell operated at room temperature. The optimization of electric fields and other operating parameters at room as well as cryogenic temperatures is described in detail. Furthermore, the extraction time of {sup 219}Rn ions was determined for several operating parameters.

  17. 30 CFR 203.73 - How do suspension volumes apply to natural gas?

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false How do suspension volumes apply to natural gas... suspension volumes apply to natural gas? You must measure natural gas production under the royalty-suspension volume as follows: 5.62 thousand cubic feet of natural gas, measured in accordance with 30 CFR part...

  18. An introduction to finite volumes for gas dynamics

    CERN Document Server

    Dubois, François

    2011-01-01

    We propose an elementary introduction to the finite volume method in the context of gas dynamics conservation laws. Our approach is founded on the advection equation, the exact integration of the associated Cauchy problem, and the so-called upwind scheme in one space dimension. It is then extended in three directions: hyperbolic linear systems and particularily the system of acoustics, gas dynamics with the help of the Roe matrix and two space dimensions by following the approach proposed by Van Leer. A special emphasis on boundary conditions is proposed all along the text.

  19. Physiology of cell volume regulation in vertebrates

    DEFF Research Database (Denmark)

    Hoffmann, Else K; Lambert, Ian H; Pedersen, Stine F

    2009-01-01

    cases, activation of volume regulatory osmolyte transport. After acute swelling, cell volume is regulated by the process of regulatory volume decrease (RVD), which involves the activation of KCl cotransport and of channels mediating K(+), Cl(-), and taurine efflux. Conversely, after acute shrinkage......, cell volume is regulated by the process of regulatory volume increase (RVI), which is mediated primarily by Na(+)/H(+) exchange, Na(+)-K(+)-2Cl(-) cotransport, and Na(+) channels. Here, we review in detail the current knowledge regarding the molecular identity of these transport pathways...... and their regulation by, e.g., membrane deformation, ionic strength, Ca(2+), protein kinases and phosphatases, cytoskeletal elements, GTP binding proteins, lipid mediators, and reactive oxygen species, upon changes in cell volume. We also discuss the nature of the upstream elements in volume sensing in vertebrate...

  20. Disordered, strongly scattering porous materials as miniature multipass gas cells

    CERN Document Server

    Svensson, Tomas; Lewander, Märta; Xu, Can T; Svanberg, Sune

    2010-01-01

    Spectroscopic gas sensing is both a commercial success and a rapidly advancing scientific field. Throughout the years, massive efforts have been directed towards improving detection limits by achieving long interaction pathlengths. Prominent examples include the use of conventional multipass gas cells, sophisticated high-finesse cavities, gas-filled holey fibers, integrating spheres, and diffusive reflectors. Despite this rich flora of approaches, there is a continuous struggle to reduce size, gas volume, cost and alignment complexity. Here, we show that extreme light scattering in porous materials can be used to realise miniature gas cells. Near-infrared transmission through a 7 mm zirconia (ZrO2) sample with a 49% porosity and subwavelength pore structure (on the order of 100 nm) gives rise to an effective gas interaction pathlength above 5 meters, an enhancement corresponding to 750 passes through a conventional multipass cell. This essentially different approach to pathlength enhancement opens a new route...

  1. LOFT reflood as a function of accumulator initial gas volume

    Energy Technology Data Exchange (ETDEWEB)

    Rhodes, H.F.

    1978-06-01

    The effect of the initial gas volume in the LOFT accumulators on the time to start of core reflood, after a LOCA, has been studied. The bases of the calculations are the data used and results presented in the Safety Analysis Report, Rev.1, August 1977, and the data in the RELAP and TOODEE2 program input and output listings. The results of this study show that an initial nitrogen volume of 12 cu ft, or more (at 600 psig initial pressure), would cause start of core reflood in time to prevent the cladding temperature from reaching 2200/sup 0/F. The 12 cu ft initial volume will expand from 600 psig, initial pressure, to about 10 psig (containment pressure shortly after start of LOCA is approximately 8 psig) when all ECC liquid has been expelled from the accumulator. This pressure margin is considered too small; the ECC flowrate will be zero before the accumulator is empty.

  2. Gas transport in solid oxide fuel cells

    CERN Document Server

    He, Weidong; Dickerson, James

    2014-01-01

    This book provides a comprehensive overview of contemporary research and emerging measurement technologies associated with gas transport in solid oxide fuel cells. Within these pages, an introduction to the concept of gas diffusion in solid oxide fuel cells is presented. This book also discusses the history and underlying fundamental mechanisms of gas diffusion in solid oxide fuel cells, general theoretical mathematical models for gas diffusion, and traditional and advanced techniques for gas diffusivity measurement.

  3. DIGESTER GAS - FUEL CELL - PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Dr.-Eng. Dirk Adolph; Dipl.-Eng. Thomas Saure

    2002-03-01

    GEW has been operating the first fuel cell in Europe producing heat and electricity from digester gas in an environmentally friendly way. The first 9,000 hours in operation were successfully concluded in August 2001. The fuel cell powered by digester gas was one of the 25 registered ''Worldwide projects'' which NRW presented at the EXPO 2000. In addition to this, it is a key project of the NRW State Initiative on Future Energies. All of the activities planned for the first year of operation were successfully completed: installing and putting the plant into operation, the transition to permanent operation as well as extended monitoring till May 2001.

  4. DEMONSTRATION OF FUEL CELLS TO RECOVER ENERGY FROM LANDFILL GAS - PHASE III. DEMONSTRATION TESTS - PHASE IV. GUIDELINES AND RECOMMENDATIONS- VOLUME 1. TECHNICAL REPORT

    Science.gov (United States)

    The report summarizes the results of a four-phase program to demonstrate that fuel cell energy recovery using a commercial phosphoric acid fuel cell is both environmentally sound and commercially feasible. Phase I, a conceptual design and evaluation study, addressed the technical...

  5. METHANE EMISSIONS FROM THE NATURAL GAS INDUSTRY VOLUME 15: GAS-ASSISTED GLYCOL PUMPS

    Science.gov (United States)

    The 15-volume report summarizes the results of a comprehensive program to quantify methane (CH4) emissions from the U.S. natural gas industry for the base year. The objective was to determine CH4 emissions from the wellhead and ending downstream at the customer's meter. The accur...

  6. Fifth DOE symposium on enhanced oil and gas recovery and improved drilling technology. Volume 3. Gas and drilling

    Energy Technology Data Exchange (ETDEWEB)

    Linville, B. [ed.

    1979-01-01

    Volume 3 contains papers from the sessions on natural gas supporting research, western gas sands project, drilling technology, and environmental effects. Individuals were processed for inclusion in the Energy Data Base.

  7. Development of Parametric Mass and Volume Models for an Aerospace SOFC/Gas Turbine Hybrid System

    Science.gov (United States)

    Tornabene, Robert; Wang, Xiao-yen; Steffen, Christopher J., Jr.; Freeh, Joshua E.

    2005-01-01

    In aerospace power systems, mass and volume are key considerations to produce a viable design. The utilization of fuel cells is being studied for a commercial aircraft electrical power unit. Based on preliminary analyses, a SOFC/gas turbine system may be a potential solution. This paper describes the parametric mass and volume models that are used to assess an aerospace hybrid system design. The design tool utilizes input from the thermodynamic system model and produces component sizing, performance, and mass estimates. The software is designed such that the thermodynamic model is linked to the mass and volume model to provide immediate feedback during the design process. It allows for automating an optimization process that accounts for mass and volume in its figure of merit. Each component in the system is modeled with a combination of theoretical and empirical approaches. A description of the assumptions and design analyses is presented.

  8. Purge gas protected transportable pressurized fuel cell modules and their operation in a power plant

    Science.gov (United States)

    Zafred, Paolo R.; Dederer, Jeffrey T.; Gillett, James E.; Basel, Richard A.; Antenucci, Annette B.

    1996-01-01

    A fuel cell generator apparatus and method of its operation involves: passing pressurized oxidant gas, (O) and pressurized fuel gas, (F), into fuel cell modules, (10 and 12), containing fuel cells, where the modules are each enclosed by a module housing (18), surrounded by an axially elongated pressure vessel (64), where there is a purge gas volume, (62), between the module housing and pressure vessel; passing pressurized purge gas, (P), through the purge gas volume, (62), to dilute any unreacted fuel gas from the modules; and passing exhaust gas, (82), and circulated purge gas and any unreacted fuel gas out of the pressure vessel; where the fuel cell generator apparatus is transpatable when the pressure vessel (64) is horizontally disposed, providing a low center of gravity.

  9. A new estimate of the volume and distribution of gas hydrate in the northern Gulf of Mexico

    Science.gov (United States)

    Majumdar, U.; Cook, A.

    2016-12-01

    In spite of the wealth of information gained over the last several decades about gas hydrate in the northern Gulf of Mexico, there is still considerable uncertainty about the distribution and volume of gas hydrate. In our assessment we build a dataset of basin-wide gas hydrate distribution and thickness, as appraised from publicly available petroleum industry well logs within the gas hydrate stability zone (HSZ), and subsequently develop a Monte Carlo to determine the volumetric estimate of gas hydrate using the dataset. We evaluate the presence of gas hydrate from electrical resistivity well logs, and categorized possible reservoir type (either sand or clay) based on the gamma ray response and resistivity curve characteristics. Out of the 798 wells with resistivity well log data within the HSZ we analyzed, we found evidence of gas hydrate in 124 wells. In this research we present a new stochastic estimate of the gas hydrate volume in the northern Gulf of Mexico guided by our well log dataset. For our Monte Carlo simulation, we divided our assessment area of 200,000 km2 into 1 km2 grid cells. Our volume assessment model incorporates variables unique to our well log dataset such as the likelihood of gas hydrate occurrence, fraction of the HSZ occupied by gas hydrate, reservoir type, and gas hydrate saturation depending on the reservoir, in each grid cell, in addition to other basic variables such as HSZ thickness and porosity. Preliminary results from our model suggests that the total volume of gas at standard temperature and pressure in gas hydrate in the northern Gulf of Mexico is in the range of 430 trillion cubic feet (TCF) to 730 TCF, with a mean volume of 585 TCF. While the reservoir distribution from our well log dataset found gas hydrate in sand reservoirs in 30 wells out of the 124 wells with evidence of gas hydrate ( 24%), we find sand reservoirs contain over half of the total volume of gas hydrate in the Gulf of Mexico, as a result of the relatively high

  10. 30 CFR 250.1163 - How must I measure gas flaring or venting volumes and liquid hydrocarbon burning volumes, and...

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false How must I measure gas flaring or venting... SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Production Requirements Flaring, Venting, and Burning Hydrocarbons § 250.1163 How must I measure gas flaring or venting volumes and liquid...

  11. Immunobiology of natural killer cells. Volume II

    Energy Technology Data Exchange (ETDEWEB)

    Lotzova, E.; Herberman, R.B.

    1986-01-01

    This book provides a review of natural killer (NK) cell-mediated immunity in humans and experimental animal system. Topics for the volume include: In vivo activities of NK cells against primary and metastatic tumors in experimental animals; involvement of NK cells in human malignant disease; impaired NK cell profile in leukemia patients; in vivo modulation of NK activity in cancer patients; implications of aberrant NK cell activity in nonmalignant, chronic diseases; NK cell role in regulation of the growth and functions of hemopoietic and lymphoid cells; NK cells active against viral, bacterial, protozoan, and fungal infections; cytokine secretion and noncytotoxic functions of human large granular lymphocytes; augmentation of NK activity; regulation of NK cell activity by suppressor cells; NK cell cloning technology and characteristics of NK cell clones; comparison of antibody-dependent cellular cytotoxicity (ADCC) and NK activity, and index.

  12. Cell swelling and volume regulation

    DEFF Research Database (Denmark)

    Hoffmann, Else Kay

    1992-01-01

    been reported. The role of the different channels was discussed. A taurine leak pathway is clearly activated after cell swelling both in astrocytes and in neurones. The relations between the effect of glutamate and cell swelling were discussed. Discussion on the clearance of potassium from...... the extracellular space was continued. Neither the spatial buffering mechanism nor the role of the Na+/K+ pump was discussed here, but additional possibilities for K+ removal were discussed. At a high extracellular K+ concentration there is a possibility of channel-mediated KCl uptake by the glia cells, and a Na......-K-2Cl cotransport system is present in astrocytes and seems to play a role at relatively low extracellular K+ concentrations (6-20 mM). The cotransport system is likely to be regulated, but little is known about its regulation in glia cells....

  13. Cell volume regulation: physiology and pathophysiology

    DEFF Research Database (Denmark)

    Lambert, I H; Hoffmann, E K; Pedersen, Stine Helene Falsig

    2008-01-01

    not only under physiological conditions, e.g. following accumulation of nutrients, during epithelial absorption/secretion processes, following hormonal/autocrine stimulation, and during induction of apoptosis, but also under pathophysiological conditions, e.g. hypoxia, ischaemia and hyponatremia....../hypernatremia. On the other hand, it has recently become clear that an increase or reduction in cell volume can also serve as a specific signal in the regulation of physiological processes such as transepithelial transport, cell migration, proliferation and death. Although the mechanisms by which cell volume perturbations...... are sensed are still far from clear, significant progress has been made with respect to the nature of the sensors, transducers and effectors that convert a change in cell volume into a physiological response. In the present review, we summarize recent major developments in the field, and emphasize...

  14. Digital volume imaging of the PEFC gas diffusion layer

    Energy Technology Data Exchange (ETDEWEB)

    Borup, Rodney L [Los Alamos National Laboratory; Mukundan, Rangachary [Los Alamos National Laboratory; Mukherjee, Partha [ORNL; Shim, Eunkyoung [NC ST

    2010-01-01

    The gas diffusion layer (GDL) plays a key role in the overall performance/durability of a polymer electrolyte fuel cell (PEFC). Of profound importance, especially in the context of water management and flooding phenomena, is the influence of the underlying pore morphology and wetting characteristics Of the GDL microstructure. In this article, we present the digital volumetric imaging (DVI) technique in order to generate the 3-D carbon paper GDL microstructure. The internal pore structure and the local microstructural variations in terms of fiber alignment and fiber/binder distributions are investigated using the several 3-D thin sections of the sample obtained from DVI.

  15. A transient method for measuring the gas volume fraction in a mixed gas-liquid flow using acoustic resonance spectroscopy

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In this paper, the feasibility of measuring the gas volume fraction in a mixed gas-liquid flow by using an acoustic resonant spectroscopy (ARS) method in a transient way is studied theoretically and experimentally. Firstly, the effects of sizes and locations of a single air bubble in a cylindrical cavity with two open ends on resonant frequencies are investigated numerically. Then, a transient measurement system for ARS is established, and the trends of the resonant frequencies (RFs) and resonant amplitudes (RAs) in the cylindrical cavity with gas flux inside are investigated experimentally. The measurement results by the proposed transient method are compared with those by steady-state ones and numerical ones. The numerical results show that the RFs of the cavity are highly sensitive to the volume of the single air bubble. A tiny bubble volume perturbation may cause a prominent RF shift even though the volume of the air bubble is smaller than 0.1% of that of the cavity. When the small air bubble moves, the RF shift will change and reach its maximum value as it is located at the middle of the cavity. As the gas volume fraction of the two-phase flow is low, both the RFs and RAs from the measurement results decrease dramatically with the increasing gas volume, and this decreasing trend gradually becomes even as the gas volume fraction increases further. These experimental results agree with the theoretical ones qualitatively. In addition, the transient method for ARS is more suitable for measuring the gas volume fraction with randomness and instantaneity than the steady-state one, because the latter could not reflect the random and instant characteristics of the mixed fluid due to the time consumption for frequency sweeping. This study will play a very important role in the quantitative measurement of the gas volume fraction of multiphase flows.

  16. Radiation from Large Gas Volumes and Heat Exchange in Steam Boiler Furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Makarov, A. N., E-mail: tgtu-kafedra-ese@mail.ru [Tver State Technical University (Russian Federation)

    2015-09-15

    Radiation from large cylindrical gas volumes is studied as a means of simulating the flare in steam boiler furnaces. Calculations of heat exchange in a furnace by the zonal method and by simulation of the flare with cylindrical gas volumes are described. The latter method is more accurate and yields more reliable information on heat transfer processes taking place in furnaces.

  17. No-migration variance petition: Draft. Volume 4, Appendices DIF, GAS, GCR (Volume 1)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-05-31

    The Department of Energy is responsible for the disposition of transuranic (TRU) waste generated by national defense-related activities. Approximately 2.6 million cubic feet of the se waste have been generated and are stored at various facilities across the country. The Waste Isolation Pilot Plant (WIPP), was sited and constructed to meet stringent disposal requirements. In order to permanently dispose of TRU waste, the DOE has elected to petition the US EPA for a variance from the Land Disposal Restrictions of RCRA. This document fulfills the reporting requirements for the petition. This report is volume 4 of the petition which presents details about the transport characteristics across drum filter vents and polymer bags; gas generation reactions and rates during long-term WIPP operation; and geological characterization of the WIPP site.

  18. Effects of respiratory rate and tidal volume on gas exchange in total liquid ventilation.

    Science.gov (United States)

    Bull, Joseph L; Tredici, Stefano; Fujioka, Hideki; Komori, Eisaku; Grotberg, James B; Hirschl, Ronald B

    2009-01-01

    Using a rabbit model of total liquid ventilation (TLV), and in a corresponding theoretical model, we compared nine tidal volume-respiratory rate combinations to identify a ventilator strategy to maximize gas exchange, while avoiding choked flow, during TLV. Nine different ventilation strategies were tested in each animal (n = 12): low [LR = 2.5 breath/min (bpm)], medium (MR = 5 bpm), or high (HR = 7.5 bpm) respiratory rates were combined with a low (LV = 10 ml/kg), medium (MV = 15 ml/kg), or high (HV = 20 ml/kg) tidal volumes. Blood gases and partial pressures, perfluorocarbon gas content, and airway pressures were measured for each combination. Choked flow occurred in all high respiratory rate-high volume animals, 71% of high respiratory rate-medium volume (HRMV) animals, and 50% of medium respiratory rate-high volume (MRHV) animals but in no other combinations. Medium respiratory rate-medium volume (MRMV) resulted in the highest gas exchange of the combinations that did not induce choke. The HRMV and MRHV animals that did not choke had similar or higher gas exchange than MRMV. The theory predicted this behavior, along with spatial and temporal variations in alveolar gas partial pressures. Of the combinations that did not induce choked flow, MRMV provided the highest gas exchange. Alveolar gas transport is diffusion dominated and rapid during gas ventilation but is convection dominated and slow during TLV. Consequently, the usual alveolar gas equation is not applicable for TLV.

  19. FUEL CELL ENERGY RECOVERY FROM LANDFILL GAS

    Science.gov (United States)

    International Fuel Cells Corporation is conducting a US Environmental Protection Agency (EPA) sponsored program to demonstrate energy recovery from landfill gas using a commercial phosphoric acid fuel cell power plant. The US EPA is interested in fuel cells for this application b...

  20. Improved Gas Seal for Electrolytic Cells

    Science.gov (United States)

    Richter, R.

    1984-01-01

    Breakage by differential thermal expansion reduced. Cells for hot electrolysis of gases improved by design that reduces vulnerability of gas seals to breakage at operating temperature of about 1000 degrees C.

  1. VolumeExplorer: Roaming Large Volumes to Couple Visualization and Data Processing for Oil and Gas Exploration

    OpenAIRE

    2005-01-01

    http://ieeexplore.ieee.org/; In this paper, we present a volume roaming system dedicated to oil and gas exploration. Our system combines probe-based volume rendering with data processing and computing. The daily oil production and the estimation of the world proven-reserves directly affect the barrel price and have a strong impact on the economy. Among others, production and correct estimation are linked to the accuracy of the subsurface model used for predicting oil reservoirs shape and size...

  2. Mathematical model of diffusion-limited gas bubble dynamics in unstirred tissue with finite volume.

    Science.gov (United States)

    Srinivasan, R Srini; Gerth, Wayne A; Powell, Michael R

    2002-02-01

    Models of gas bubble dynamics for studying decompression sickness have been developed by considering the bubble to be immersed in an extravascular tissue with diffusion-limited gas exchange between the bubble and the surrounding unstirred tissue. In previous versions of this two-region model, the tissue volume must be theoretically infinite, which renders the model inapplicable to analysis of bubble growth in a finite-sized tissue. We herein present a new two-region model that is applicable to problems involving finite tissue volumes. By introducing radial deviations to gas tension in the diffusion region surrounding the bubble, the concentration gradient can be zero at a finite distance from the bubble, thus limiting the tissue volume that participates in bubble-tissue gas exchange. It is shown that these deviations account for the effects of heterogeneous perfusion on gas bubble dynamics, and are required for the tissue volume to be finite. The bubble growth results from a difference between the bubble gas pressure and an average gas tension in the surrounding diffusion region that explicitly depends on gas uptake and release by the bubble. For any given decompression, the diffusion region volume must stay above a certain minimum in order to sustain bubble growth.

  3. LANDFILL GAS PRETREATMENT FOR FUEL CELL APPLICATIONS

    Science.gov (United States)

    The paper discusses the U.S. EPA's program, underway at International Fuel Cells Corporation, to demonstrate landfill methane control and the fuel cell energy recovery concept. In this program, two critical issues are being addressed: (1) a landfill gas cleanup method that would ...

  4. Operating a fuel cell using landfill gas

    Energy Technology Data Exchange (ETDEWEB)

    Trippel, C.E.; Preston, J.L. Jr.; Trocciola, J.; Spiegel, R.

    1996-12-31

    An ONSI PC25{trademark}, 200 kW (nominal capacity) phosphoric acid fuel cell operating on landfill gas is installed at the Town of Groton Flanders Road landfill in Groton, Connecticut. This joint project by the Connecticut Light & Power Company (CL&P) which is an operating company of Northeast Utilities, the Town of Groton, International Fuel Cells (IFC), and the US EPA is intended to demonstrate the viability of installing, operating and maintaining a fuel cell operating on landfill gas at a landfill site. The goals of the project are to evaluate the fuel cell and gas pretreatment unit operation, test modifications to simplify the GPU design and demonstrate reliability of the entire system.

  5. The study of volume ultrasonic waves propagation in the gas-containing iron ore pulp.

    Science.gov (United States)

    Morkun, V; Morkun, N; Pikilnyak, A

    2015-02-01

    The results of research of the volume ultrasonic waves propagation in the gas-containing iron ore slurry using ultrasonic phased array technology is presented. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Free volume and gas permeation in ion-exchanged forms of the Nafion® membrane

    Science.gov (United States)

    Mohamed, Hamdy F. M.; Kobayashi, Y.; Kuroda, C. S.; Ohira, A.

    2010-04-01

    Variations of free volume and gas permeability of the Nafion® membrane upon ion-exchange of H+ with Cs+ or Pt2+ was studied as a function of temperature. Free volume was quantified using the positron annihilation lifetime technique. Our results showed that the free volume (VFV,Ps) of the dried membrane is enlarged by thermal expansion. It was found that the ion-exchange significantly expands the free volume and at the same time decreases the permeabilities of O2 and H2. Good linear correlations between the logarithm of permeabilities of O2 and H2 at different temperatures and 1/VFV,Ps for the ion-exchanged forms of Nafion® in the dried state suggest an important role played by the free volume in gas permeation. Considerable downward deviation of the correlations for the ion-exchanged ionomers from the H+-form suggested the importance of polymer stiffening in gas permeation.

  7. Shear-induced Volume Decrease in MDCK Cells

    Science.gov (United States)

    Heo, Jinseok; Sachs, Frederick; Wang, Jianbin; Hua, Susan Z.

    2013-01-01

    Using a microfluidic cell volume sensor we measured the change in the cell volume of Madin-Darby Canine Kidney (MDCK) cells induced by shear stress. An increase in shear stress from 0.2 to 2.0 dyn/cm2 resulted in a volume decrease to a steady state volume ~ 20 – 30 % smaller than the initial resting cell volume. Independent experiments based on fluorescence quenching confirmed the volume reduction. This shear-induced cell shrinkage was irreversible on the time scale of the experiment (~ 30 min). Treatment of 0.1 μM Hg2+ significantly inhibited the volume decrease, suggesting that the shear-induced cell shrinkage is associated with water efflux through aquaporins. The volume decrease cannot be inhibited by 75 mM TEA, 100 μM DIDS, or 100 μM Gd3+ suggesting that volume reduction is not directly mediated by K+ and Cl− channels that typically function during regulatory volume decrease (RVD), nor is it through cationic stretch-activated ion channels (SACs). The process also appears to be Ca2+ independent because it was insensitive to intracellular Ca2+ level. Since cell volume is determined by the intracellular water content, we postulate that the shear induced reductions in cell volume may arise from increased intracellular hydrostatic pressure as the cell is deformed under flow, which promotes the efflux of water. The increase in internal pressure in a deformable object under the flow is supported by the finite element mechanical model. PMID:22759987

  8. Theoretical test of Jarzynski's equality for reversible volume-switching processes of an ideal gas system.

    Science.gov (United States)

    Sung, Jaeyoung

    2007-07-01

    We present an exact theoretical test of Jarzynski's equality (JE) for reversible volume-switching processes of an ideal gas system. The exact analysis shows that the prediction of JE for the free energy difference is the same as the work done on the gas system during the reversible process that is dependent on the shape of path of the reversible volume-switching process.

  9. Cell volume-regulated cation channels.

    Science.gov (United States)

    Wehner, Frank

    2006-01-01

    Considering the enormous turnover rates of ion channels when compared to carriers it is quite obvious that channel-mediated ion transport may serve as a rapid and efficient mechanism of cell volume regulation. Whenever studied in a quantitative fashion the hypertonic activation of non-selective cation channels is found to be the main mechanism of regulatory volume increase (RVI). Some channels are inhibited by amiloride (and may be related to the ENaC), others are blocked by Gd(3) and flufenamate (and possibly linked to the group of transient receptor potential (TRP) channels). Nevertheless, the actual architecture of hypertonicity-induced cation channels remains to be defined. In some preparations, hypertonic stress decreases K(+) channel activity so reducing the continuous K(+) leak out of the cell; this is equivalent to a net gain of cell osmolytes facilitating RVI. The hypotonic activation of K(+) selective channels appears to be one of the most common principles of regulatory volume decrease (RVD) and, in most instances, the actual channels involved could be identified on the molecular level. These are BKCa (or maxi K(+)) channels, IK(Ca) and SK(Ca) channels (of intermediate and small conductance, respectively), the group of voltage-gated (Kv) channels including their Beta (or Kv ancilliary) subunits, two-pore K(2P) channels, as well as inwardly rectifying K(+) (Kir) channels (also contributing to K(ATP) channels). In some cells, hypotonicity activates non-selective cation channels. This is surprising, at first sight, because of the inside negative membrane voltage and the sum of driving forces for Na(+) and K(+) diffusion across the cell membrane rather favouring net cation uptake. Some of these channels, however, exhibit a P(K)/P(Na) significantly higher than 1, whereas others are Ca(++) permeable linking hypotonic stress to the activation of Ca(++) dependent ion channels. In particular, the latter holds for the group of TRPs which are specialised in the

  10. Enhanced recovery of unconventional gas. The methodology--Volume III (of 3 volumes)

    Energy Technology Data Exchange (ETDEWEB)

    Kuuskraa, V. A.; Brashear, J. P.; Doscher, T. M.; Elkins, L. E.

    1979-02-01

    The methodology is described in chapters on the analytic approach, estimated natural gas production, recovery from tight gas sands, recovery from Devonian shales, recovery from coal seams, and recovery from geopressured aquifers. (JRD)

  11. Industrial Fuel Gas Demonstration Plant Program. Volume 1. Demonstration plant environmental analysis (Deliverable No. 27)

    Energy Technology Data Exchange (ETDEWEB)

    Gray, Robert W.; Swift, Richard J.; Krause, Arthur J.; Berkey, Edgar

    1979-08-01

    This environmental report describes the proposed action to construct, test and operate a coal gasification demonstration plant in Memphis, Tennessee, under the co-sponsorship of the Memphis Light, Gas and Water Division (MLGW) and the US Department of Energy (DOE). This document is Volume I of a three-volume Environmental Report. Volume I consists of the Summary, Introduction and the Description of the Proposed Action. Volume II consists of the Description of the Existing Environment. Volume III contains the Environmental Impacts of the Proposed Action, Mitigating Measures and Alternatives to the Proposed Action.

  12. Industrial Fuel Gas Demonstration Plant Program. Volume III. Demonstration plant environmental analysis (Deliverable No. 27)

    Energy Technology Data Exchange (ETDEWEB)

    1979-08-01

    An Environmental Report on the Memphis Light, Gas and Water Division Industrial Fuel Demonstration Plant was prepared for submission to the US Department of Energy under Contract ET-77-C-01-2582. This document is Volume III of a three-volume Environmental Report. Volume I consists of the Summary, Introduction and the Description of the Proposed Action. Volume II consists of the Description of the Existing Environment. Volume III contains the Environmental Impacts of the Proposed Action, Mitigating Measures and Alternatives to the Proposed Action.

  13. Coal liquefaction and gas conversion: Proceedings. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-31

    Volume II contains papers presented at the following sessions: Indirect Liquefaction (oxygenated fuels); and Indirect Liquefaction (Fischer-Tropsch technology). Selected papers have been processed separately for inclusion in the Energy Science and Technology Database.

  14. Fuel Gas Demonstration Plant Program. Volume I. Demonstration plant

    Energy Technology Data Exchange (ETDEWEB)

    1979-01-01

    The objective of this project is for Babcock Contractors Inc. (BCI) to provide process designs, and gasifier retort design for a fuel gas demonstration plant for Erie Mining Company at Hoyt Lake, Minnesota. The fuel gas produced will be used to supplement natural gas and fuel oil for iron ore pellet induration. The fuel gas demonstration plant will consist of five stirred, two-stage fixed-bed gasifier retorts capable of handling caking and non-caking coals, and provisions for the installation of a sixth retort. The process and unit design has been based on operation with caking coals; however, the retorts have been designed for easy conversion to handle non-caking coals. The demonstration unit has been designed to provide for expansion to a commercial plant (described in Commercial Plant Package) in an economical manner.

  15. [Inspection of gas cylinders in storage at TA-54, Area L]. Volume 1, Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-06-23

    ERC sampled, analyzed, and recontainerized when necessary gas cylinders containing various chemicals in storage at Los Alamos TA-54 Area L. A vapor containment structure was erected. A total of 179 cylinders was processed; 39 were repackaged; and 55 were decommissioned. This report summarizes the operation; this is Volume 1 of five volumes.

  16. EVALUATION OF VAPOR EQUILIBRATION AND IMPACT OF PURGE VOLUME ON SOIL-GAS SAMPLING RESULTS

    Science.gov (United States)

    Sequential sampling was utilized at the Raymark Superfund site to evaluate attainment of vapor equilibration and the impact of purge volume on soil-gas sample results. A simple mass-balance equation indicates that removal of three to five internal volumes of a sample system shou...

  17. ECONOMETRIC MODELING OF THE DYNAMICS OF VOLUMES HYDROCARBONS OF SMALL OIL AND GAS ENTERPRISES

    Directory of Open Access Journals (Sweden)

    GORLOV A.V.

    2015-01-01

    Full Text Available In this paper investigates the principles of functioning of small oil and gas enterprises of Russia. The basic characteristics and socio-economic tasks performed by the small oil and gas enterprises. Made correlation and regression analysis, a result of which the pair correlation coefficients between the indicator of development of small oil and gas enterprises (volumes hydrocarbons and the factors that characterize the work environment of their operation; built regressions, describing the process of development of small oil and gas enterprises. With a view to forecasting the development of small oil and gas enterprises built production function of Cobb-Douglas and selected econometric model, has good predictive properties. Made predictive calculations dynamics of volumes hydrocarbons of small oil and gas enterprises on formulating scenarios for the planning period (2015-2016 years.

  18. Direct volume rendering methods for cell structures.

    Science.gov (United States)

    Martišek, Dalibor; Martišek, Karel

    2012-01-01

    The study of the complicated architecture of cell space structures is an important problem in biology and medical research. Optical cuts of cells produced by confocal microscopes enable two-dimensional (2D) and three-dimensional (3D) reconstructions of observed cells. This paper discuses new possibilities for direct volume rendering of these data. We often encounter 16 or more bit images in confocal microscopy of cells. Most of the information contained in these images is unsubstantial for the human vision. Therefore, it is necessary to use mathematical algorithms for visualization of such images. Present software tools as OpenGL or DirectX run quickly in graphic station with special graphic cards, run very unsatisfactory on PC without these cards and outputs are usually poor for real data. These tools are black boxes for a common user and make it impossible to correct and improve them. With the method proposed, more parameters of the environment can be set, making it possible to apply 3D filters to set the output image sharpness in relation to the noise. The quality of the output is incomparable to the earlier described methods and is worth increasing the computing time. We would like to offer mathematical methods of 3D scalar data visualization describing new algorithms that run on standard PCs very well.

  19. Liquefied natural gas as a transportation fuel for heavy-duty trucks: Volume I

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-01

    This document contains Volume 1 of a three-volume manual designed for use with a 2- to 3-day liquefied natural gas (LNG) training course. Transportation and off-road agricultural, mining, construction, and industrial applications are discussed. This volume provides a brief introduction to the physics and chemistry of LNG; an overview of several ongoing LNG projects, economic considerations, LNG fuel station technology, LNG vehicles, and a summary of federal government programs that encourage conversion to LNG.

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

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, C.W.; Alzheimer, J.M.; Brewster, M.E.; Chen, G.; Reid, H.C.; Shepard, C.L.; Terrones, G. [Pacific Northwest National Lab., Richland, WA (United States); Mendoza, R.E. [Westinghouse Hanford Co., Richland, WA (United States)

    1996-09-01

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

  1. An assessment of unstructured grid finite volume schemes for cold gas hypersonic flow calculations

    Directory of Open Access Journals (Sweden)

    João Luiz F. Azevedo

    2009-06-01

    Full Text Available A comparison of five different spatial discretization schemes is performed considering a typical high speed flow application. Flowfields are simulated using the 2-D Euler equations, discretized in a cell-centered finite volume procedure on unstructured triangular meshes. The algorithms studied include a central difference-type scheme, and 1st- and 2nd-order van Leer and Liou flux-vector splitting schemes. These methods are implemented in an efficient, edge-based, unstructured grid procedure which allows for adaptive mesh refinement based on flow property gradients. Details of the unstructured grid implementation of the methods are presented together with a discussion of the data structure and of the adaptive refinement strategy. The application of interest is the cold gas flow through a typical hypersonic inlet. Results for different entrance Mach numbers and mesh topologies are discussed in order to assess the comparative performance of the various spatial discretization schemes.

  2. Free Volume and Gas Permeation in Anthracene Maleimide-Based Polymers of Intrinsic Microporosity

    Directory of Open Access Journals (Sweden)

    Muntazim Munir Khan

    2015-05-01

    Full Text Available High free-volume copolymers were prepared via polycondensation with 2,3,5,6,-tetrafluoroterephthalonitrile (TFTPN in which a portion of the 3,3,3',3'-tetramethyl-1,1'-spirobisindane (TTSBI of PIM-1 was replaced with dibutyl anthracene maleimide (4bIII. An investigation of free volume using positron annihilation lifetime spectroscopy (PALS, and gas permeation measurements was carried out for the thin film composite copolymer membranes and compared to PIM-1. The average free volume hole size and the gas permeance of the copolymer membranes increased with decreasing TTSBI content in the copolymer.

  3. Rapid estimate of solid volume in large tuff cores using a gas pycnometer

    Energy Technology Data Exchange (ETDEWEB)

    Thies, C. [ed.; Geddis, A.M.; Guzman, A.G. [and others

    1996-09-01

    A thermally insulated, rigid-volume gas pycnometer system has been developed. The pycnometer chambers have been machined from solid PVC cylinders. Two chambers confine dry high-purity helium at different pressures. A thick-walled design ensures minimal heat exchange with the surrounding environment and a constant volume system, while expansion takes place between the chambers. The internal energy of the gas is assumed constant over the expansion. The ideal gas law is used to estimate the volume of solid material sealed in one of the chambers. Temperature is monitored continuously and incorporated into the calculation of solid volume. Temperature variation between measurements is less than 0.1{degrees}C. The data are used to compute grain density for oven-dried Apache Leap tuff core samples. The measured volume of solid and the sample bulk volume are used to estimate porosity and bulk density. Intrinsic permeability was estimated from the porosity and measured pore surface area and is compared to in-situ measurements by the air permeability method. The gas pycnometer accommodates large core samples (0.25 m length x 0.11 m diameter) and can measure solid volume greater than 2.20 cm{sup 3} with less than 1% error.

  4. Volume morphology of printable solar cells

    Directory of Open Access Journals (Sweden)

    Joachim Loos

    2010-10-01

    Full Text Available Printable polymer or hybrid solar cells (PSCs have the potential to become one of the leading technologies of the 21st century in conversion of sunlight to electrical energy. Because of their ease of processing from solution fast and low cost mass production of devices is possible in a roll-to-roll printing fashion. The performance of such printed devices, in turn, is determined to a large extent by the three-dimensional organization of the photoactive layer, i.e. layer where light is absorbed and converted into free electrical charges, and its contacts with the charge collecting electrodes. In this review I briefly introduce our current understanding of morphology-performance relationships in PSCs with specific focus on electron tomography as analytical tool providing volume information with nanometer resolution.

  5. Gas Plasma Effects on Living Cells

    Science.gov (United States)

    Stoffels, E.; Sladek, R. E. J.; Kieft, I. E.

    This paper surveys the research activities at the Eindhoven University of Technology (The Netherlands) in the area of biomedical applications of gas discharge plasmas. A non-thermal atmospheric plasma source (the plasma needle) has been developed, and its interactions with living mammalian cells and bacteria are studied. It is concluded that plasma can efficiently kill bacteria without harming the cells, and also influence the cells without causing cell death (necrosis). In future it will lead to applications like skin (wound) and caries treatment.

  6. Theoretical and experimental analysis of a multiphase screw pump, handling gas-liquid mixtures with very high gas volume fractions

    Energy Technology Data Exchange (ETDEWEB)

    Raebiger, K. [LEISTRITZ Pumpen GmbH, Nuremberg (Germany); Faculty of Advanced Technology, University of Glamorgan, Pontypridd, Wales (United Kingdom); Maksoud, T.M.A.; Ward, J. [Faculty of Advanced Technology, University of Glamorgan, Pontypridd, Wales (United Kingdom); Hausmann, G. [Department of Mechanical Engineering and Building Services Engineering, University of Applied Sciences, Nuremberg (Germany)

    2008-09-15

    In the investigation of the pumping behaviour of multiphase screw pumps, handling gas-liquid mixtures with very high gas volume fractions, theoretical and experimental analyses were performed. A new theoretical screw pump model was developed, which calculates the time-dependent conditions inside the several chambers of a screw pump as well as the exchange of mass and energy between these chambers. By means of the performed experimental analysis, the screw pump model was verified, especially at very high gas volume fractions from 90% to 99%. The experiments, which were conducted with the reference fluids water and air, can be divided mainly into the determination of the steady state pumping behaviour on the one hand and into the analysis of selected transient operating conditions on the other hand, whereas the visualisation of the leakage flows through the circumferential gaps was rounded off the experimental analysis. (author)

  7. Deep Panuke offshore gas development project summary : volume 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-11-15

    This project summary is the first of 5 documents intended to comprise a development plan application for approval of the Deep Panuke Offshore Gas Development. EnCana Corporation plans to produce gas from the completion of 4 existing wells and 1 new production well feeding a central production facility sized for a peak sales gas throughput of 8.5 x 10{sup 6} m{sup 3}/day. The project was designed to meet the significant and growing demand for natural gas for markets in Canada and the United States. The development phase of the project is expected to continue until 2010. Following the commissioning of the project facilities, project life is expected to be in the range of 8 to 17.5 years. The project summary included details of EnCana Corporation's development strategy as well as a detailed description of the project. Project principles and management principles were outlined. Environmental assessment methodologies were presented, as well as details of the potential environmental and socio-economic effects of the project. A project schedule was provided, as well as a regulatory overview. Project components and activities included development drilling; subsea equipment; a mobile offshore processing unit (MOPU); offshore pipelines; and onshore pipeline and facilities. Environmental, health and safety management plans were provided, as well as details of public and Aboriginal consultation processes. It was concluded that the project is not likely to have significant adverse environmental or socio-economic impacts. The results of the economic opportunities and impacts analysis conducted for the project indicated that the project will have a positive impact on the communities of the province of Nova Scotia and Canada. 4 tabs., 3 figs.

  8. Mechanisms underlying KCNQ1channel cell volume sensitivity

    DEFF Research Database (Denmark)

    Hammami, Sofia

    Cells are constantly exposed to changes in cell volume during cell metabolism, nutrient uptake, cell proliferation, cell migration and salt and water transport. In order to cope with these perturbations, potassium channels in line with chloride channels have been shown to be likely contributors...... to the process of cell volume adjustments. A great diversity of potassium channels being members of either the 6TM, 4 TM or 2 TM K+ channel gene family have been shown to be strictly regulated by small, fast changes in cell volume. However, the precise mechanism underlying the K+ channel sensitivity to cell...... mechanism of regulation. Besides being regulated by cell volume, KCNQ1 is also modulated by the interaction of the ß subunit KCNE1 giving rise to the cardiac IKs delayed rectifier potassium current. Apart from altering the kinetic characteristics of the KCNQ1 channel current, KCNE1 also augments the KCNQ1...

  9. Importance of evaluation of uncertainties on the measurement of natural gas and petroleum volumes; Importancia da avaliacao das incertezas na medicao dos volumes de petroleo e gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Silva Filho, Jose Alberto Pinheiro da; Oliveira, Thiago Barra Vidal de; Mata, Josaphat Dias da [PETROBRAS, Rio de Janeiro, RJ (Brazil)], Emails: jose.pinheiro@petrobras.com.br, thiagovidal@petrobras.com.br, josaphat@petrobras.com.br; Val, Luiz Gustavo do [Instituto de Qualidade e Metrologia (IQM), Rio de Janeiro, RJ (Brazil)], E-mail: gdoval.iqm@petrobras.com.br

    2009-07-01

    The measurement is considered as the 'cash register' of the enterprises, increasing the accuracy and the exigence at each step when come close to the delivery points, where the 0.1 % of differences are discussed. The work presents the approach used in the evaluation of measurement uncertainties in the volumes obtained of petroleum and natural gas at the processes of production in Brazil, and in the international level as well.

  10. Effect of gas channel height on gas flow and gas diffusion in a molten carbonate fuel cell stack

    Science.gov (United States)

    Hirata, Haruhiko; Nakagaki, Takao; Hori, Michio

    An investigation is made of the relationships between the gas channel height, the gas-flow characteristics, and the gas-diffusion characteristics in a plate heat-exchanger type molten carbonate fuel cell stack. Effects of the gas channel height on the uniformity and pressure loss of the gas flow are evaluated by numerical analysis using a computational fluid dynamics code. The effects of the gas channel height on the distribution of the reactive gas concentration in the direction perpendicular to the channel flow are evaluated by an analytical solution of the two-dimensional concentration transport equation. Considering the results for uniformity and pressure loss of the gas flow, and for distribution of the reactive gas concentration, the appropriate gas channel height in the molten carbonate fuel cell stack is investigated.

  11. Cell volume homeostatic mechanisms: effectors and signalling pathways

    DEFF Research Database (Denmark)

    Hoffmann, E K; Pedersen, Stine Helene Falsig

    2011-01-01

    . Later work addressed the mechanisms through which cellular signalling pathways regulate the volume regulatory effectors or flux pathways. These studies were facilitated by the molecular identification of most of the relevant channels and transporters, and more recently also by the increased...... understanding of their structures. Finally, much current research in the field focuses on the most up- and downstream components of these paths: how cells sense changes in cell volume, and how cell volume changes in turn regulate cell function under physiological and pathophysiological conditions....

  12. Hot-gas cleanup system model development. Volume I. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Ushimaru, K.; Bennett, A.; Bekowies, P.J.

    1982-11-01

    This two-volume report summarizes the state of the art in performance modeling of advanced high-temperature, high-pressure (HTHP) gas cleanup devices. Volume I contains the culmination of the research effort carried over the past 12 months and is a summary of research achievements. Volume II is the user's manual for the computer programs developed under the present research project. In this volume, Section 2 presents background information on pressurized, fluidized-bed combustion concepts, a description of the role of the advanced gas cleanup systems, and a list of advanced gas cleanup systems that are currently in development under DOE sponsorship. Section 3 describes the methodology for the software architecture that forms the basis of the well-disciplined and structured computer programs developed under the present project. Section 4 reviews the fundamental theories that are important in analyzing the cleanup performance of HTHP gas filters. Section 5 discusses the effect of alkali agents in HTHP gas cleanup. Section 6 evaluates the advanced HTHP gas cleanup models based on their mathematical integrity, availability of supporting data, and the likelihood of commercialization. As a result of the evaluation procedure detailed in Section 6, five performance models were chosen to be incorporated into the overall system simulation code, ASPEN. These five models (the electrocyclone, ceramic bag filter, moving granular bed filter, electrostatic granular bed filter, and electrostatic precipitator) are described in Section 7. The method of cost projection for these five models is discussed in Section 8. The supporting data and validation of the computer codes are presented in Section 9, and finally the conclusions and recommendations for the HTHP gas cleanup system model development are given in Section 10. 72 references, 19 figures, 25 tables.

  13. Gas permeation measurement under defined humidity via constant volume/variable pressure method

    KAUST Repository

    Jan Roman, Pauls

    2012-02-01

    Many industrial gas separations in which membrane processes are feasible entail high water vapour contents, as in CO 2-separation from flue gas in carbon capture and storage (CCS), or in biogas/natural gas processing. Studying the effect of water vapour on gas permeability through polymeric membranes is essential for materials design and optimization of these membrane applications. In particular, for amine-based CO 2 selective facilitated transport membranes, water vapour is necessary for carrier-complex formation (Matsuyama et al., 1996; Deng and Hägg, 2010; Liu et al., 2008; Shishatskiy et al., 2010) [1-4]. But also conventional polymeric membrane materials can vary their permeation behaviour due to water-induced swelling (Potreck, 2009) [5]. Here we describe a simple approach to gas permeability measurement in the presence of water vapour, in the form of a modified constant volume/variable pressure method (pressure increase method). © 2011 Elsevier B.V.

  14. METHANE EMISSIONS FROM THE NATURAL GAS INDUSTRY VOLUME 13: CHEMICAL INJECTION PUMPS

    Science.gov (United States)

    The 15-volume report summarizes the results of a comprehensive program to quantify methane (CH4) emissions from the U.S. natural gas industry for the base year. The objective was to determine CH4 emissions from the wellhead and ending downstream at the customer's meter. The accur...

  15. Modelling dynamic liquid-gas systems: Extensions to the volume-of-fluid solver

    CSIR Research Space (South Africa)

    Heyns, Johan A

    2013-06-01

    Full Text Available This study presents the extension of the volume-of-fluid solver, interFoam, for improved accuracy and efficiency when modelling dynamic liquid-gas systems. Examples of these include the transportation of liquids, such as in the case of fuel carried...

  16. METHANE EMISSIONS FROM THE NATURAL GAS INDUSTRY VOLUME 12: PNEUMATIC DEVICES

    Science.gov (United States)

    The 15-volume report summarizes the results of a comprehensive program to quantify methane (CH4) emissions from the U.S. natural gas industry for the base year. The objective was to determine CH4 emissions from the wellhead and ending downstream at the customer's meter. The accur...

  17. METHANE EMISSIONS FROM THE NATURAL GAS INDUSTRY VOLUME 11: COMPRESSOR DRIVER EXHAUST

    Science.gov (United States)

    The 15-volume report summarizes the results of a comprehensive program to quantify methane (CH4) emissions from the U.S. natural gas industry for the base year. The objective was to determine CH4 emissions from the wellhead and ending downstream at the customer's meter. The accur...

  18. METHANE EMISSIONS FROM THE NATURAL GAS INDUSTRY VOLUME 7: BLOW AND PURGE ACTIVITIES

    Science.gov (United States)

    The 15-volume report summarizes the results of a comprehensive program to quantify methane (CH4) emissions from the U.S. natural gas industry for the base year. The objective was to determine CH4 emissions from the wellhead and ending downstream at the customer's meter. The accur...

  19. Relation Between the Cell Volume and the Cell Cycle Dynamics in Mammalian cell

    Science.gov (United States)

    Magno, A. C. G.; Oliveira, I. L.; Hauck, J. V. S.

    2016-08-01

    The main goal of this work is to add and analyze an equation that represents the volume in a dynamical model of the mammalian cell cycle proposed by Gérard and Goldbeter (2011) [1]. The cell division occurs when the cyclinB/Cdkl complex is totally degraded (Tyson and Novak, 2011)[2] and it reaches a minimum value. At this point, the cell is divided into two newborn daughter cells and each one will contain the half of the cytoplasmic content of the mother cell. The equations of our base model are only valid if the cell volume, where the reactions occur, is constant. Whether the cell volume is not constant, that is, the rate of change of its volume with respect to time is explicitly taken into account in the mathematical model, then the equations of the original model are no longer valid. Therefore, every equations were modified from the mass conservation principle for considering a volume that changes with time. Through this approach, the cell volume affects all model variables. Two different dynamic simulation methods were accomplished: deterministic and stochastic. In the stochastic simulation, the volume affects every model's parameters which have molar unit, whereas in the deterministic one, it is incorporated into the differential equations. In deterministic simulation, the biochemical species may be in concentration units, while in stochastic simulation such species must be converted to number of molecules which are directly proportional to the cell volume. In an effort to understand the influence of the new equation a stability analysis was performed. This elucidates how the growth factor impacts the stability of the model's limit cycles. In conclusion, a more precise model, in comparison to the base model, was created for the cell cycle as it now takes into consideration the cell volume variation

  20. Model documentation Natural Gas Transmission and Distribution Model of the National Energy Modeling System. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-02-26

    The Natural Gas Transmission and Distribution Model (NGTDM) of the National Energy Modeling System is developed and maintained by the Energy Information Administration (EIA), Office of Integrated Analysis and Forecasting. This report documents the archived version of the NGTDM that was used to produce the natural gas forecasts presented in the Annual Energy Outlook 1996, (DOE/EIA-0383(96)). The purpose of this report is to provide a reference document for model analysts, users, and the public that defines the objectives of the model, describes its basic approach, and provides detail on the methodology employed. Previously this report represented Volume I of a two-volume set. Volume II reported on model performance, detailing convergence criteria and properties, results of sensitivity testing, comparison of model outputs with the literature and/or other model results, and major unresolved issues.

  1. The effects of different syringe volume, needle size and sample volume on blood gas analysis in syringes washed with heparin

    Science.gov (United States)

    Küme, Tuncay; Şişman, Ali Rıza; Solak, Ahmet; Tuğlu, Birsen; Çinkooğlu, Burcu; Çoker, Canan

    2012-01-01

    Introductıon: We evaluated the effect of different syringe volume, needle size and sample volume on blood gas analysis in syringes washed with heparin. Materials and methods: In this multi-step experimental study, percent dilution ratios (PDRs) and final heparin concentrations (FHCs) were calculated by gravimetric method for determining the effect of syringe volume (1, 2, 5 and 10 mL), needle size (20, 21, 22, 25 and 26 G) and sample volume (0.5, 1, 2, 5 and 10 mL). The effect of different PDRs and FHCs on blood gas and electrolyte parameters were determined. The erroneous results from nonstandardized sampling were evaluated according to RiliBAK’s TEa. Results: The increase of PDRs and FHCs was associated with the decrease of syringe volume, the increase of needle size and the decrease of sample volume: from 2.0% and 100 IU/mL in 10 mL-syringe to 7.0% and 351 IU/mL in 1 mL-syringe; from 4.9% and 245 IU/mL in 26G to 7.6% and 380 IU/mL in 20 G with combined 1 mL syringe; from 2.0% and 100 IU/mL in full-filled sample to 34% and 1675 IU/mL in 0.5 mL suctioned sample into 10 mL-syringe. There was no statistical difference in pH; but the percent decreasing in pCO2, K+, iCa2+, iMg2+; the percent increasing in pO2 and Na+ were statistical significance compared to samples full-filled in syringes. The all changes in pH and pO2 were acceptable; but the changes in pCO2, Na+, K+ and iCa2+ were unacceptable according to TEa limits except fullfilled-syringes. Conclusions: The changes in PDRs and FHCs due nonstandardized sampling in syringe washed with liquid heparin give rise to erroneous test results for pCO2 and electrolytes. PMID:22838185

  2. Electrochemical Cell with Improved Water or Gas Management

    Science.gov (United States)

    Smith, William F. (Inventor); McElroy, James F. (Inventor); LaGrange, Jay W. (Inventor)

    2015-01-01

    An electrochemical cell having a water/gas porous separator prepared from a polymeric material and one or more conductive cell components that pass through, or are located in close proximity to, the water/gas porous separator, is provided. The inventive cell provides a high level of in-cell electrical conductivity.

  3. Cell Volume Regulation and Apoptotic Volume Decrease in Rat Distal Colon Superficial Enterocytes

    Directory of Open Access Journals (Sweden)

    Stefania Antico

    2013-12-01

    Full Text Available Background: The colon epithelium is physiologically exposed to osmotic stress, and the activation of cell volume regulation mechanisms is essential in colonocyte physiology. Moreover, colon is characterized by a high apoptotic rate of mature cells balancing the high division rate of stem cells. Aim: The aim of the present work was to investigate the main cell volume regulation mechanisms in rat colon surface colonocytes and their role in apoptosis. Methods: Cell volume changes were measured by light microscopy and video imaging on colon explants; apoptosis sign appearance was monitored by confocal microscopy on annexin V/propidium iodide labeled explants. Results: Superficial colonocytes showed a dynamic regulation of their cell volume during anisosmotic conditions with a Regulatory Volume Increase (RVI response following hypertonic shrinkage and Regulatory Volume Decrease (RVD response following hypotonic swelling. RVI was completely inhibited by bumetanide, while RVD was completely abolished by high K+ or iberiotoxin treatment and by extracellular Ca2+ removal. DIDS incubation was also able to affect the RVD response. When colon explants were exposed to H2O2 as apoptotic inducer, colonocytes underwent an isotonic volume decrease ascribable to Apoptotic Volume Decrease (AVD within about four hours of exposure. AVD was shown to precede annexin V positivity. It was also inhibited by high K+ or iberiotoxin treatment. Interestingly, treatment with iberiotoxin significantly inhibited apoptosis progression. Conclusions: In rat superficial colonocytes K+ efflux through high conductance Ca2+-activated K+ channels (BK channels was demonstrated to be the main mechanism of RVD and to plays also a crucial role in the AVD process and in the progression of apoptosis.

  4. Free volumes and gas transport in polymers: amine-modified epoxy resins as a case study.

    Science.gov (United States)

    Patil, Pushkar N; Roilo, David; Brusa, Roberto S; Miotello, Antonio; Aghion, Stefano; Ferragut, Rafael; Checchetto, Riccardo

    2016-02-07

    The CO2 transport process was studied in a series of amine-modified epoxy resins having different cross-linking densities but the same chemical environment for the penetrant molecules. Positron Annihilation Lifetime Spectroscopy (PALS) was used to monitor the free volume structure of the samples and experimentally evaluate their fractional free volume fh(T) and its temperature evolution. The analysis of the free volume hole size distribution showed that all the holes have a size large enough to accommodate the penetrant molecules at temperatures T above the glass transition temperature Tg. The measured gas diffusion constants at T > Tg have been reproduced in the framework of the free volume theory of diffusion using a novel procedure based on the use of fh(T) as an input experimental parameter.

  5. Design, construction and performance tests of a prototype micromegas chamber with two readout planes in a common gas volume

    Science.gov (United States)

    Brickwedde, Bernard; Düdder, Andreas; Schott, Matthias; Yildirim, Eda

    2017-08-01

    In this paper, the design and the performance of a prototype detector based on MicroMegas technology with two detection planes in a common gas volume is discussed. The detector is suited for the forward region of LHC detectors, addressing the high-rate environment and limited available space. Each detection plane has an active area of 9 × 9cm2 with a two-dimensional strip readout and is separated by a common gas region with a height of 14 mm . A micro-mesh, working as a cathode, is placed in the middle of the common gas volume separating it into two individual cells. This setup allows for an angle reconstruction of incoming particles with a precision of ∼ 2 mrad. Since this design reduces the impact of multiple scattering effects by the reduced material budget, possible applications for low energy beam experiments can be envisioned. The performance of the prototype detector has been tested with a 4 . 4 GeV electron beam, provided by the test beam facility at DESY.

  6. Cell volume regulation in epithelial physiology and cancer

    DEFF Research Database (Denmark)

    Pedersen, Stine Helene Falsig; Hoffmann, Else Kay; Novak, Ivana

    2013-01-01

    The physiological function of epithelia is transport of ions, nutrients, and fluid either in secretory or absorptive direction. All of these processes are closely related to cell volume changes, which are thus an integrated part of epithelial function. Transepithelial transport and cell volume...... transporters and channels with key physiological functions in epithelia and known roles in the development of cancer in these tissues. Their roles in cell survival, cell cycle progression, and development of drug resistance in epithelial cancers will be discussed....... such as cancer, transepithelial and cell volume regulatory ion transport are dys-regulated. Furthermore, epithelial architecture and coordinated ion transport function are lost, cell survival/death balance is altered, and new interactions with the stroma arise, all contributing to drug resistance. Since altered...

  7. Quantitative measurement of regional lung gas volume by synchrotron radiation computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Monfraix, Sylvie [European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble (France); Bayat, Sam [European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble (France); Porra, Liisa [Department of Physical Sciences, University of Helsinki, POB 64, FIN-00014 Helsinki (Finland); Berruyer, Gilles [European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble (France); Nemoz, Christian [European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble (France); Thomlinson, William [Canadian Light Source, 101 Perimeter Road, Saskatoon, SK S7N 0X4 (Canada); Suortti, Pekka [Department of Physical Sciences, University of Helsinki, POB 64, FIN-00014 Helsinki (Finland); Sovijaervi, Anssi R A [Department of Clinical Physiology and Nuclear Medicine, Helsinki University Central Hospital, POB 340, FIN-00029 HUS, Helsinki (Finland)

    2005-01-07

    The aim of this study was to assess the feasibility of a novel respiration-gated spiral synchrotron radiation computed tomography (SRCT) technique for direct quantification of absolute regional lung volumes, using stable xenon (Xe) gas as an inhaled indicator. Spiral SRCT with K-edge subtraction using two monochromatic x-ray beams was used to visualize and directly quantify inhaled Xe concentrations and airspace volumes in three-dimensional (3D) reconstructed lung images. Volume measurements were validated using a hollow Xe-filled phantom. Spiral images spanning 49 mm in lung height were acquired following 60 breaths of an 80% Xe-20% O{sub 2} gas mixture, in two anaesthetized and mechanically ventilated rabbits at baseline and after histamine aerosol inhalation. Volumetric images of 20 mm lung sections were obtained at functional residual capacity (FRC) and at end-inspiration. 3D images showed large patchy filling defects in peripheral airways and alveoli following histamine provocation. Local specific lung compliance was calculated based on FRC/end-inspiration images in normal lung. This study demonstrates spiral SRCT as a new technique for direct determination of regional lung volume, offering possibilities for non-invasive investigation of regional lung function and mechanics, with a uniquely high spatial resolution. An example of non-uniform volume distribution in rabbit lung following histamine inhalation is presented.

  8. Sampling small volumes of ambient ammonia using a miniaturized gas sampler.

    Science.gov (United States)

    Timmer, Björn; Olthuis, Wouter; van den Berg, Albert

    2004-06-01

    The development of a gas sampler for a miniaturized ambient ammonia detector is described. A micromachined channel system is realized in glass and silicon using powder blasting and anodic bonding. The analyte gas is directly mixed with purified water, dissolving the ammonia that will dissociate into ammonium ions. Carrier gas bubbles are subsequently removed from the liquid stream through a venting hole sealed with a microporous water repellent PTFE membrane. A flow restrictor is placed at the outlet of the sampler to create a small overpressure underneath the membrane, enabling the gas to leave through the membrane. Experiments with a gas flow of 1 ml min(-1), containing ammonia concentrations ranging from 9.4 ppm to 0.6 ppm in a nitrogen carrier flow have been carried out, at a water flow of 20 microl min(-1). The ammonium concentration in the sample solution is measured with an electrolyte conductivity detector. The measured values correspond with the concentration calculated from the initial ammonia concentration in the analyte gas, the fifty times concentration enhancement due to the gas-liquid volume difference and the theoretical dissociation equilibrium as a function of the resulting pH.

  9. Hot and Dense Hadron Gas (HG): A New Excluded-volume approach

    CERN Document Server

    Tiwari, S K

    2013-01-01

    We formulate a thermodynamically consistent equation of state (EOS), based on excluded-volume approach, for a hot, dense hadron gas (HG). We calculate various thermodynamical quantities of HG and various hadron ratios and compare our model results with the results of other excluded-volume models and experimental data. We also calculate various transport coefficients such as $\\eta/s$ etc. and compare them with other HG model results. Furthermore, we test the validity of our model in getting the rapidity spectra of various hadrons and the effect of flow on them is investigated by matching our predictions with the experimental data.

  10. Cell volume and membrane stretch independently control K+ channel activity

    DEFF Research Database (Denmark)

    Bomholtz, Sofia Hammami; Willumsen, Niels J; Olsen, Hervør L

    2009-01-01

    A number of potassium channels including members of the KCNQ family and the Ca(2+) activated IK and SK, but not BK, are strongly and reversibly regulated by small changes in cell volume. It has been argued that this general regulation is mediated through sensitivity to changes in membrane stretch...... was not affected by membrane stretch. The results indicate that (1) activation of BK channels by local membrane stretch is not mimicked by membrane stress induced by cell swelling, and (2) activation of KCNQ1 channels by cell volume increase is not mediated by local tension in the cell membrane. We conclude....... To test this hypothesis we have studied the regulation of KCNQ1 and BK channels after expression in Xenopus oocytes. Results from cell-attached patch clamp studies (approximately 50 microm(2) macropatches) in oocytes expressing BK channels demonstrate that the macroscopic volume-insensitive BK current...

  11. Thin gas cell with GRIN fiber lens for intra-cavity fiber laser gas sensors

    Science.gov (United States)

    Li, Mo; Dai, Jing-min; Peng, Gang-ding

    2009-07-01

    Fiber laser gas sensors based on the intra-cavity absorption spectroscopy require the use of gas cells. We propose a simple and reliable gas cell using graded-index fiber lens (GFL) based all-fiber collimator. Conventional gas cells usually utilize direct fiber-to-fiber coupling without collimators or graded-index (GRIN) lens as collimators. Direct fiberto- fiber gas cell has simple configuration, but it suffers from high coupling loss and stray light interference. Gas cells applying fiber pigtailed GRIN lens are advantageous to achieve low coupling loss. However, fiber pigtailed GRIN lens requires accurate and complicated alignment and glue packaging which could compromise long term reliability and thermal stability. The proposed technique fabricates all-fiber collimators by simply splicing a short section of gradedindex fiber to single mode fiber which is both compact and durable. With that collimator, the gas cell can be fabricated very thin and are suitable for extreme environments with high temperature and vibration. In this paper, we have carried out experiment and analysis to evaluate the proposed technique. The coupling efficiency is studied versus different GFL gradient parameter profiles using ray matrix transformation of the complex beam parameter. Experiments are also done to prove the practical feasibility of the collimator. The analysis indicates that gas cell using GFLs can overcome the disadvantages of traditional design; it may replace the conventional gas cells in practical applications.

  12. Gas Breakthrough Pressure (GBP through Claystones: Correlation with FIB/SEM Imaging of the Pore Volume

    Directory of Open Access Journals (Sweden)

    Song Yang

    2016-07-01

    Full Text Available This contribution uses six claystone samples imaged by FIB/SEM (Focused Ion Beam/Scanning Electron Microscopy, within micrometric volumes located in the clay matrix; their 3D connected pore network is identified down to 17-22 nm pore size. All samples are gently dried to minimize damage, and several are impregnated with Poly(Methyl MethAcrylate (PMMA resin to avoid further damage during FIB/SEM observations. Three pore volumes out of six are connected between two parallel end surfaces through crack-like pores; two are not connected between any two parallel end surfaces; only one sample has a connected pore network distinct from cracks. By assuming varied pathways for gas to migrate by capillarity through the connected pore volumes (either by taking the shortest path, or through the largest path, or through the most frequent pore size, or by simulating the ingress of a non wetting fluid, we determine the Gas Breakthrough Pressure (GBP through the initially fully liquid saturated claystone, from these micrometric volumes. The scale change (from the micrometric to the macroscopic scale is assumed possible without changing the GBP value, and clay/water interactions are not accounted for. By comparison with GBP values measured in the laboratory on centimetric-sized claystone samples, it is concluded that breakthrough occurs most probably by capillary digitation; micro-cracks are the most probable pathways for gas, so that gas does not progress in a homogeneous manner through the claystone, as standard macroscopic finite element models would represent it. For intact claystone, predictions based on the capillary ingress of a non wetting fluid provide a GBP value ranging between 7-14 MPa.

  13. Signal Transduction Involved in Cell Volume Regulation

    NARCIS (Netherlands)

    Th. van der Wijk (Thea)

    2001-01-01

    textabstract1.fammalian cells are surrounded by a selective permeable plasma membrane that allmvs the interior of the cell to differ in composition from the surrounding solution. The plasma membrane is formed by a bilayer of (phospho-) lipids and contains many different proteins. Hydrophobic molecul

  14. Sensors and signal transduction pathways in vertebrate cell volume regulation

    DEFF Research Database (Denmark)

    Hoffmann, Else K; Pedersen, Stine F

    2006-01-01

    will be discussed. In contrast to the simple pathway of osmosensing in yeast, cells from vertebrate organisms appear to exhibit multiple volume sensing systems, the specific mechanism(s) activated being cell type- and stimulus-dependent. Candidate sensors include integrins and growth factor receptors, while other...

  15. Small-Size Resonant Photoacoustic Cell of Inclined Geometry for Gas Detection

    CERN Document Server

    Gorelik, A V; Nikonovich, F N; Zakharich, M P; Chebotar, A I; Firago, V A; Stetsik, V M; Kazak, N S; Starovoitov, V S

    2009-01-01

    A photoacoustic cell intended for laser detection of trace gases is represented. The cell is adapted so as to enhance the gas-detection performance and, simultaneously, to reduce the cell size. The cell design provides an efficient cancellation of the window background (a parasite response due to absorption of laser beam in the cell windows) and acoustic isolation from the environment for an acoustic resonance of the cell. The useful photoacoustic response from a detected gas, window background and noise are analyzed in demonstration experiments as functions of the modulation frequency for a prototype cell with the internal volume ~ 0.5 cm^3. The minimal detectable absorption for the prototype is estimated to be ~ 1.2 10^{-8} cm^{-1} W Hz^{-1/2}.

  16. Bistability: requirements on cell-volume, protein diffusion, and thermodynamics.

    Directory of Open Access Journals (Sweden)

    Robert G Endres

    Full Text Available Bistability is considered wide-spread among bacteria and eukaryotic cells, useful, e.g., for enzyme induction, bet hedging, and epigenetic switching. However, this phenomenon has mostly been described with deterministic dynamic or well-mixed stochastic models. Here, we map known biological bistable systems onto the well-characterized biochemical Schlögl model, using analytical calculations and stochastic spatiotemporal simulations. In addition to network architecture and strong thermodynamic driving away from equilibrium, we show that bistability requires fine-tuning towards small cell volumes (or compartments and fast protein diffusion (well mixing. Bistability is thus fragile and hence may be restricted to small bacteria and eukaryotic nuclei, with switching triggered by volume changes during the cell cycle. For large volumes, single cells generally loose their ability for bistable switching and instead undergo a first-order phase transition.

  17. Reduction of total lung capacity in obese men: comparison of total intrathoracic and gas volumes.

    Science.gov (United States)

    Watson, R A; Pride, N B; Thomas, E Louise; Fitzpatrick, J; Durighel, G; McCarthy, J; Morin, S X; Ind, P W; Bell, J D

    2010-06-01

    Restriction of total lung capacity (TLC) is found in some obese subjects, but the mechanism is unclear. Two hypotheses are as follows: 1) increased abdominal volume prevents full descent of the diaphragm; and 2) increased intrathoracic fat reduces space for full lung expansion. We have measured total intrathoracic volume at full inflation using magnetic resonance imaging (MRI) in 14 asymptomatic obese men [mean age 52 yr, body mass index (BMI) 35-45 kg/m2] and 7 control men (mean age 50 yr, BMI 22-27 kg/m2). MRI volumes were compared with gas volumes at TLC. All measurements were made with subjects supine. Obese men had smaller functional residual capacity (FRC) and FRC-to-TLC ratio than control men. There was a 12% predicted difference in mean TLC between obese (84% predicted) and control men (96% predicted). In contrast, differences in total intrathoracic volume (MRI) at full inflation were only 4% predicted TLC (obese 116% predicted TLC, control 120% predicted TLC), because mediastinal volume was larger in obese than in control [heart and major vessels (obese 1.10 liter, control 0.87 liter, P=0.016) and intrathoracic fat (obese 0.68 liter, control 0.23 liter, P80% predicted (ON) was 26% predicted TLC. Mediastinal volume was similar in OR (1.84 liter) and ON (1.73 liter), but total intrathoracic volume was 19% predicted TLC smaller in OR than in ON. We conclude that the major factor restricting TLC in some obese men was reduced thoracic expansion at full inflation.

  18. Cell volume and membrane stretch independently control K+ channel activity.

    Science.gov (United States)

    Hammami, Sofia; Willumsen, Niels J; Olsen, Hervør L; Morera, Francisco J; Latorre, Ramón; Klaerke, Dan A

    2009-05-15

    A number of potassium channels including members of the KCNQ family and the Ca(2+) activated IK and SK, but not BK, are strongly and reversibly regulated by small changes in cell volume. It has been argued that this general regulation is mediated through sensitivity to changes in membrane stretch. To test this hypothesis we have studied the regulation of KCNQ1 and BK channels after expression in Xenopus oocytes. Results from cell-attached patch clamp studies (approximately 50 microm(2) macropatches) in oocytes expressing BK channels demonstrate that the macroscopic volume-insensitive BK current increases with increasing negative hydrostatic pressure (suction) applied to the pipette. Thus, at a pipette pressure of -5.0 +/- 0.1 mmHg the increase amounted to 381 +/- 146% (mean +/- S.E.M., n = 6, P < 0.025). In contrast, in oocytes expressing the strongly volume-sensitive KCNQ1 channel, the current was not affected by membrane stretch. The results indicate that (1) activation of BK channels by local membrane stretch is not mimicked by membrane stress induced by cell swelling, and (2) activation of KCNQ1 channels by cell volume increase is not mediated by local tension in the cell membrane. We conclude that stretch and volume sensitivity can be considered two independent regulatory mechanisms.

  19. Volume regulatory hormones and plasma volume in pregnant women with sickle cell disorder

    Directory of Open Access Journals (Sweden)

    Bosede B Afolabi

    2016-09-01

    Full Text Available Background: Sickle cell disease (haemoglobin SS (HbSS mainly affects those of West African origin and is associated with hypervolaemia. Plasma volume rises by up to 50% in normal pregnancy but was previously found to be paradoxically contracted in late sickle cell pregnancy. The renin–angiotensin–aldosterone system is activated very early in human pregnancy to support the plasma volume expansion. We hypothesised that activation of the renin–angiotensin–aldosterone system would be blunted in pregnant women with sickle cell disease. Materials and methods: We measured plasma volume and concentrations of plasma renin, angiotensinogen, aldosterone and other volume-related hormones in a cross-sectional study of pregnant and non-pregnant Nigerian women with HbSS or HbAA. Results: Plasma volume was higher in non-pregnant HbSS than HbAA women, but had not risen by 16 weeks, unlike plasma volume in HbAA women. The concentration of plasma renin also rose significantly less by 16 weeks in HbSS; angiotensinogen and aldosterone concentrations increased. Conclusions: The lower plasma renin concentration at 16 weeks with HbSS could be either primary or secondary to vasoconstriction related to inadequate vasodilator activity. The contracted plasma volume might then stimulate aldosterone synthesis by non-angiotensin II dependent stimulation. Studies of vasodilators such as nitric oxide, vasodilator eicosanoids or the PlGF/VEGF/sFlT-1 axis in pregnant HbSS and HbAA women will test this hypothesis.

  20. Microfluidic Cell Volume Biosensor for High Throughput Drug Screening

    Science.gov (United States)

    2005-01-01

    method is non- invasive, and it provides real-time measurement of changes in cell volume for both adherent and suspended cells. The microfluidic nature of...channels as well as the release of organic osmolytes, such as taurine [11]. Upon returning to isotonic solution at the end of RVD we observed cell...Haussinger, Biochem. J, 313,697 (1996). [2] Sachs, F. Nature Structural Biology 9, 636-637 (2002). [3] F. Schliess, and D. Haussinger, Bio. Chem. 383

  1. A gas cell for stopping, storing and polarizing radioactive particles

    CERN Document Server

    Sytema, A; Böll, O; Chernowitz, D; Dijck, E A; Grasdijk, J O; Hoekstra, S; Jungmann, K; Mathavan, S C; Meinema, C; Mohanty, A; Müller, S E; Portela, M Nuñez; Onderwater, C J G; Pijpker, C; Willmann, L; Wilschut, H W

    2016-01-01

    A radioactive beam of 20Na is stopped in a gas cell filled with Ne gas. The stopped particles are polarized by optical pumping. The degree of polarization that can be achieved is studied. A maximum polarization of 50% was found. The dynamic processes in the cell are described with a phenomenological model.

  2. A gas cell for stopping, storing and polarizing radioactive particles

    NARCIS (Netherlands)

    Sytema, Auke; van den Berg, Joost; Böll, Oliver; Chernowitz, Daniel; Dijck, Elwin; Grasdijk, Jan; Hoekstra, Steven; Jungmann, Klaus-Peter; Chirayath Mathavan, Sreekanth; Meinema, Jacoba Roelien; Mueller, Stefan E.; Portela, M. N.; Onderwater, Cornelis; Pijpker, Coen; Willmann, Lorenz; Wilschut, H. W.

    2016-01-01

    A radioactive beam of Na-20 is stopped in a gas cell filled with Ne gas. The stopped particles are polarized by optical pumping. The degree of polarization that can be achieved is studied. A maximum polarization of 50% was found. The dynamic processes in the cell are described with a phenomenologica

  3. EOS simulation and GRNN modeling of the constant volume depletion behavior of gas condensate reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Elsharkawy, A.M.; Foda, S.G. [Kuwait University, Safat (Kuwait). Petroleum Engineering Dept.

    1998-03-01

    Currently, two approaches are being used to predict the changes in retrograde gas condensate composition and estimate the pressure depletion behavior of gas condensate reservoirs. The first approach uses the equation of states whereas the second uses empirical correlations. Equations of states (EOS) are poor predictive tools for complex hydrocarbon systems. The EOS needs adjustment against phase behavior data of reservoir fluid of known composition. The empirical correlation does not involve numerous numerical computations but their accuracy is limited. This study presents two general regression neural network (GRNN) models. The first model, GRNNM1, is developed to predict dew point pressure and gas compressibility at dew point using initial composition of numerous samples while the second model, GRNNM2, is developed to predict the changes in well stream effluent composition at any stages of pressure depletion. GRNNM2 can also be used to determine the initial reservoir fluid composition using dew point pressure, gas compressibility at dew point, and reservoir temperature. These models are based on analysis of 142 sample of laboratory studies of constant volume depletion (CVD) for gas condensate systems forming a total of 1082 depletion stages. The database represents a wide range of gas condensate systems obtained worldwide. The performance of the GRNN models has been compared to simulation results of the equation of state. The study shows that the proposed general regression neural network models are accurate, valid, and reliable. These models can be used to forecast CVD data needed for many reservoir engineering calculations in case laboratory data is unavailable. The GRNN models save computer time involved in EOS calculations. The study also show that once these models are properly trained they can be used to cut expenses of frequent sampling and laborious experimental CVD tests required for gas condensate reservoirs. 55 refs., 13 figs., 6 tabs.

  4. Prediction of forage intake using in vitro gas production methods: Comparison of multiphase fermentation kinetics measured in an automated gas test, and combined gas volume and substrate degradability measurements in a manual syringe system

    NARCIS (Netherlands)

    Blümmel, M.; Cone, J.W.; Gelder, van A.H.; Nshalai, I.; Umunna, N.N.; Makkar, H.P.S.; Becker, K.

    2005-01-01

    This study investigated two approaches to in vitro analysis of gas production data, being a three phase model with long (¿72 h) incubation times, to obtain kinetics and asymptotic values of gas production, and combination of gas volume measurements with residue determinations after a relatively shor

  5. Treating network junctions in finite volume solution of transient gas flow models

    Science.gov (United States)

    Bermúdez, Alfredo; López, Xián; Vázquez-Cendón, M. Elena

    2017-09-01

    A finite volume scheme for the numerical solution of a non-isothermal non-adiabatic compressible flow model for gas transportation networks on non-flat topography is introduced. Unlike standard Euler equations, the model takes into account wall friction, variable height and heat transfer between the pipe and the environment which are source terms. The case of one single pipe was considered in a previous reference by the authors, [8], where a finite volume method with upwind discretization of the flux and source terms has been proposed in order to get a well-balanced scheme. The main goal of the present paper is to go a step further by considering a network of pipes. The main issue is the treatment of junctions for which container-like 2D finite volumes are introduced. The couplings between pipes (1D) and containers (2D) are carefully described and the conservation properties are analyzed. Numerical tests including real gas networks are solved showing the performance of the proposed methodology.

  6. RESOLVE Survey Photometry and Volume-limited Calibration of the Photometric Gas Fractions Technique

    CERN Document Server

    Eckert, Kathleen D; Stark, David V; Moffett, Amanda J; Norris, Mark A; Snyder, Elaine M; Hoversten, Erik A

    2015-01-01

    We present custom-processed UV, optical, and near-IR photometry for the RESOLVE survey, a volume-limited census of stellar, gas, and dynamical mass within two subvolumes of the nearby universe (RESOLVE-A and -B), complete down to baryonic mass ~10^9.1-9.3 Msun. In contrast to standard pipeline photometry (e.g., SDSS), our photometry uses optimal background subtraction, avoids suppressing color gradients, and includes systematic errors. With these improvements, we measure brighter magnitudes, larger radii, bluer colors, and a real increase in scatter around the red sequence. Combining stellar masses from our photometry with the RESOLVE-A HI mass census, we create volume-limited calibrations of the photometric gas fractions (PGF) technique, which predicts gas-to-stellar mass ratios (G/S) from galaxy colors and optional additional parameters. We analyze G/S-color residuals vs. potential third parameters, finding that axial ratio is the best independent and physically meaningful third parameter. We define a "modi...

  7. Cell volume regulation in epithelial physiology and cancer

    DEFF Research Database (Denmark)

    Pedersen, Stine Helene Falsig; Hoffmann, Else Kay; Novak, Ivana

    2013-01-01

    The physiological function of epithelia is transport of ions, nutrients, and fluid either in secretory or absorptive direction. All of these processes are closely related to cell volume changes, which are thus an integrated part of epithelial function. Transepithelial transport and cell volume...... expression of ion transporters and channels is now recognized as one of the hallmarks of cancer, it is timely to consider this especially for epithelia. Epithelial cells are highly proliferative and epithelial cancers, carcinomas, account for about 90% of all cancers. In this review we will focus on ion...... transporters and channels with key physiological functions in epithelia and known roles in the development of cancer in these tissues. Their roles in cell survival, cell cycle progression, and development of drug resistance in epithelial cancers will be discussed....

  8. A new method for the measurement of meteorite bulk volume via ideal gas pycnometry

    Science.gov (United States)

    Li, Shijie; Wang, Shijie; Li, Xiongyao; Li, Yang; Liu, Shen; Coulson, Ian M.

    2012-10-01

    To date, of the many techniques used to measure the bulk volume of meteorites, only three methods (Archimedean bead method, 3-D laser imaging and X-ray microtomography) can be considered as nondestructive or noncontaminating. The bead method can show large, random errors for sample sizes of smaller than 5 cm3. In contrast, 3-D laser imaging is a high-accuracy method even when measuring the bulk volumes of small meteorites. This method is both costly and time consuming, however, and meteorites of a certain shape may lead to some uncertainties in the analysis. The method of X-ray microtomography suffers from the same problems as 3-D laser imaging. This study outlines a new method of high-accuracy, nondestructive and noncontaminating measurement of the bulk volume of meteorite samples. In order to measure the bulk volume of a meteorite, one must measure the total volume of the balloon vacuum packaged meteorite and the volume of balloon that had been used to enclose the meteorite using ideal gas pycnometry. The difference between the two determined volumes is the bulk volume of the meteorite. Through the measurement of zero porosity metal spheres and tempered glass fragments, our results indicate that for a sample which has a volume of between 0.5 and 2 cm3, the relative error of the measurement is less than ±0.6%. Furthermore, this error will be even smaller (less than ±0.1%) if the determined sample size is larger than 2 cm3. The precision of this method shows some volume dependence. For samples smaller than 1 cm3, the standard deviations are less than ±0.328%, and these values will fall to less than ±0.052% for samples larger than 2 cm3. The porosities of nine fragments of Jilin, GaoGuenie, Zaoyang and Zhaodong meteorites have been measured using our vacuum packaging-pycnometry method, with determined average porosities of Jilin, GaoGuenie, Zaoyang and Zhaodong of 9.0307%, 2.9277%, 17.5437% and 5.9748%, respectively. These values agree well with the porosities

  9. Evaluation of the programmed temperature vaporiser for large-volume injection of biological samples in gas chromatography

    NARCIS (Netherlands)

    van Hout, M.W J; de Zeeuw, R.A; Franke, J.P.; de Jong, G.J.

    1999-01-01

    The use of a programmed temperature vaporiser (PTV) with a packed liner was evaluated for the injection of large volumes (up to 100 mu l) of plasma extracts in a gas chromatograph. Solvent purity, which is essential when large volumes are injected into the GC system, was determined. Special attentio

  10. A Simple Mercury-Free Laboratory Apparatus to Study the Relationship between Pressure, Volume, and Temperature in a Gas

    Science.gov (United States)

    McGregor, Donna; Sweeney, William V.; Mills, Pamela

    2012-01-01

    A simple and inexpensive mercury-free apparatus to measure the change in volume of a gas as a function of pressure at different temperatures is described. The apparatus is simpler than many found in the literature and can be used to study variations in pressure, volume, and temperature. (Contains 1 table and 7 figures.)

  11. A Simple Mercury-Free Laboratory Apparatus to Study the Relationship between Pressure, Volume, and Temperature in a Gas

    Science.gov (United States)

    McGregor, Donna; Sweeney, William V.; Mills, Pamela

    2012-01-01

    A simple and inexpensive mercury-free apparatus to measure the change in volume of a gas as a function of pressure at different temperatures is described. The apparatus is simpler than many found in the literature and can be used to study variations in pressure, volume, and temperature. (Contains 1 table and 7 figures.)

  12. Model documentation: Natural Gas Transmission and Distribution Model of the National Energy Modeling System; Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-02-24

    The Natural Gas Transmission and Distribution Model (NGTDM) is a component of the National Energy Modeling System (NEMS) used to represent the domestic natural gas transmission and distribution system. NEMS is the third in a series of computer-based, midterm energy modeling systems used since 1974 by the Energy Information Administration (EIA) and its predecessor, the Federal Energy Administration, to analyze domestic energy-economy markets and develop projections. This report documents the archived version of NGTDM that was used to produce the natural gas forecasts used in support of the Annual Energy Outlook 1994, DOE/EIA-0383(94). The purpose of this report is to provide a reference document for model analysts, users, and the public that defines the objectives of the model, describes its basic design, provides detail on the methodology employed, and describes the model inputs, outputs, and key assumptions. It is intended to fulfill the legal obligation of the EIA to provide adequate documentation in support of its models (Public Law 94-385, Section 57.b.2). This report represents Volume 1 of a two-volume set. (Volume 2 will report on model performance, detailing convergence criteria and properties, results of sensitivity testing, comparison of model outputs with the literature and/or other model results, and major unresolved issues.) Subsequent chapters of this report provide: (1) an overview of the NGTDM (Chapter 2); (2) a description of the interface between the National Energy Modeling System (NEMS) and the NGTDM (Chapter 3); (3) an overview of the solution methodology of the NGTDM (Chapter 4); (4) the solution methodology for the Annual Flow Module (Chapter 5); (5) the solution methodology for the Distributor Tariff Module (Chapter 6); (6) the solution methodology for the Capacity Expansion Module (Chapter 7); (7) the solution methodology for the Pipeline Tariff Module (Chapter 8); and (8) a description of model assumptions, inputs, and outputs (Chapter 9).

  13. Excluded-volume effects for a hadron gas in Yang-Mills theory

    CERN Document Server

    Alba, Paolo; Nada, Alessandro; Panero, Marco; Stöcker, Horst

    2016-01-01

    When the multiplicities of particles produced in heavy-ion collisions are fitted to the hadron-resonance-gas model, excluded-volume effects play a significant role. In this work, we study the impact of such effects onto the equation of state of pure Yang-Mills theory at low temperatures, comparing the predictions of the statistical model with lattice results. In particular, we present a detailed analysis of the SU(2) and SU(3) Yang-Mills theories: we find that, for both of them, the best fits to the equilibrium thermodynamic quantities are obtained when one assumes that the volume of different glueball states is inversely proportional to their mass. The implications of these findings for QCD are discussed.

  14. The equivalent electrical permittivity of gas-solid mixtures at intermediate solid volume fractions.

    Energy Technology Data Exchange (ETDEWEB)

    Torczynski, John Robert; Ceccio, Steven Louis; Tortora, Paul Richard

    2005-07-01

    Several mixture models are evaluated for their suitability in predicting the equivalent permittivity of dielectric particles in a dielectric medium for intermediate solid volume fractions (0.4 to 0.6). Predictions of the Maxwell, Rayleigh, Bottcher and Bruggeman models are compared to computational simulations of several arrangements of solid particles in a gas and to the experimentally determined permittivity of a static particle bed. The experiment uses spherical glass beads in air, so air and glass permittivity values (1 and 7, respectively) are used with all of the models and simulations. The experimental system used to measure the permittivity of the static particle bed and its calibration are described. The Rayleigh model is found to be suitable for predicting permittivity over the entire range of solid volume fractions (0-0.6).

  15. Gas productivity related to cleat volumes derived from focused resistivity tools in coalbed methane (CBM) fields

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Y.H.; Peeters, M.; Cloud, T.A.; Van Kirk, C.W. [Kerr McGee Rocky Mountain Corporation, Denver, CO (United States)

    2006-06-15

    Cleats are critical for coal-bed methane (CBM) production, but operators usually lack a viable method to determine productivity except for costly well tests. Wireline logs, run over the CBM deposits of the Drunkards Wash Unit located in the Uinta Basin of Utah, were used to develop a new method to relate productivity to the cleat volume. The latter is derived from a focused resistivity log and the wellbore-fluid resistivity. Induction tools are unsuitable for this method, because they are dominated by borehole effects in high resistivity coals and low resistivity mud. Moreover, they read too deep to be significantly affected by the substitution of formation fluid by borehole fluid in the cleats on which the method is based. The method was demonstrated by relating cleat volume to CBM gas productivity in 24 wells, an exercise that clearly separated good from poor producers.

  16. Significant Increase in Hydrogen Photoproduction Rates and Yields by Wild-Type Algae is Detected at High Photobioreactor Gas Phase Volume (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2012-07-01

    This NREL Hydrogen and Fuel Cell Technical Highlight describes how hydrogen photoproduction activity in algal cultures can be improved dramatically by increasing the gas-phase to liquid-phase volume ratio of the photobioreactor. NREL, in partnership with subcontractors from the Institute of Basic Biological Problems in Pushchino, Russia, demonstrated that the hydrogen photoproduction rate in algal cultures always decreases exponentially with increasing hydrogen partial pressure above the culture. The inhibitory effect of high hydrogen concentrations in the photobioreactor gas phase on hydrogen photoproduction by algae is significant and comparable to the effect observed with some anaerobic bacteria.

  17. Dissipative properties of hot and dense hadronic matter in excluded volume hadron resonance gas model

    CERN Document Server

    Kadam, Guru Prakash

    2015-01-01

    We estimate dissipative properties viz: shear and bulk viscosities of hadronic matter using rel- ativistic Boltzmann equation in relaxation time approximation within ambit of excluded volume hadron resonance gas (EHRG) model. We find that at zero baryon chemical potential the shear viscosity to entropy ratio ({\\eta}/s) decreases with temperature and reaches very close to Kovtun-Son- Starinets (KSS) bound. At sufficiently large baryon chemical potential this ratio shows same behav- ior as a function of temperature but goes below KSS bound. We further find that along chemical freezout line {\\eta}/s increases monotonically while the bulk viscosity to entropy ratio ({\\zeta}/s) decreases monotonically.

  18. Proceedings of the seventh annual gasification and gas stream cleanup systems contractors review meeting: Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Ghate, M.R.; Markel, K.E. Jr.; Jarr, L.A.; Bossart, S.J. (eds.)

    1987-08-01

    On June 16 through 19, 1987, METC sponsored the Seventh Annual Gasification and Gas Stream Cleanup Systems Contractors Review Meeting which was held at the Sheraton Lakeview Conference Center in Morgantown, West Virginia. The primary purpose of the meeting was threefold: to review the technical progress and current status of the gasification and gas stream cleanup projects sponsored by the Department of Energy; to foster technology exchange among participating researchers and other technical communities; to facilitate interactive dialogues which would identify research needs that would make coal-based gasification systems more attractive economically and environmentally. More than 310 representatives of Government, academia, industry, and foreign energy research organizations attended the 4-day meeting. Fifty-three papers and thirty poster displays were presented summarizing recent developments in the gasification and gas stream cleanup programs. Volume I covers information presented at sessions 1 through 4 on systems for the production of Co-products and industrial fuel gas, environmental projects, and components and materials. Individual papers have been processed for the Energy Data Base.

  19. Proceedings of the seventh annual gasification and gas stream cleanup systems contractors review meeting: Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Ghate, M.R.; Markel, K.E. Jr.; Jarr, L.A.; Bossart, S.J. (eds.)

    1987-08-01

    On June 16 through 19, 1987, METC sponsored the Seventh Annual Gasification and Gas Stream Cleanup Systems Contractors Review Meeting which was held at the Sheraton Lakeview Conference Center in Morgantown, West Virginia. The primary purpose of the meeting was threefold: to review the technical progress and current status of the gasification and gas stream cleanup projects sponsored by the Department of Energy; to foster technology exchange among participating researchers and other technical communities; to facilitate interactive dialogues which would identify research needs that would make coal-based gasification systems more attractive economically and environmentally. More than 310 representatives of Government, academia, industry, and foreign energy research organizations attended the 4-day meeting. Fifty-three papers and thirty poster dsplays were presented summarizing recent developments in the gasification and gas stream cleanup programs. Volume II covers papers presented at sessions 5 and 6 on system for the production of synthesis gas, and on system for the production of power. All papers have been processed for inclusion in the Energy Data Base.

  20. Off-line test of the KISS gas cell

    Energy Technology Data Exchange (ETDEWEB)

    Hirayama, Yoshikazu, E-mail: yoshikazu.hirayama@kek.jp [Institute of Particle and Nuclear Studies (IPNS), High Energy Accelerator Research Organization (KEK), Ibaraki 305-0801 (Japan); Watanabe, Yutaka; Imai, Nobuaki; Ishiyama, Hironobu; Jeong, Sun-Chan; Miyatake, Hiroari; Oyaizu, Michihiro [Institute of Particle and Nuclear Studies (IPNS), High Energy Accelerator Research Organization (KEK), Ibaraki 305-0801 (Japan); Kim, Yung Hee [Seoul National University, Seoul 151 742 (Korea, Republic of); Mukai, Momo [Tsukuba University, Ibaraki 305 0006 (Japan); Matsuo, Yukari; Sonoda, Tetsu; Wada, Michiharu [Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351 0198 (Japan); Huyse, Mark; Kudryavtsev, Yuri; Van Duppen, Piet [Instituut voor Kern-en Stralingsfysica, KU Leuven, B-3001 Leuven (Belgium)

    2013-12-15

    Highlights: • Construction of the KEK Isotope Separation System (KISS) at RIKEN. • Ionization scheme of an iron. • Measurement of transport time profile in a gas cell. -- Abstract: The KEK Isotope Separation System (KISS) has been constructed at RIKEN to study the β-decay properties of neutron-rich isotopes with neutron numbers around N = 126 for application to astrophysics. A key component of KISS is a gas cell filled with argon gas at a pressure of 50 kPa to stop and collect the unstable nuclei, where the isotopes of interest will be selectively ionized using laser resonance ionization. We have performed off-line tests to study the basic properties of the gas cell and of KISS using nickel and iron filaments placed in the gas cell.

  1. Sickle cell patients are characterized by a reduced glycocalyx volume

    NARCIS (Netherlands)

    E.J. van Beers (Eduard); M. Nieuwdorp (Max); A.J. Duits (Ashley); L.M. Evers (Ludo); J.J.B. Schnog; B.J. Biemond (Bart)

    2008-01-01

    textabstractThe glycocalyx is an important anti-inflammatory and anti-adhesive barrier at the luminal side of endothelial cells. Glycocalyx volume was significantly reduced in sickle cell patients (HbSS/HbSβ0-thalassemia median 0.47L, IQR 0.27-0.66, HbSC/HbSβ+-thalassemia 0.23L, 0.0-0.58) compared w

  2. Transient receptor potential channels in mechanosensing and cell volume regulation

    DEFF Research Database (Denmark)

    Pedersen, Stine Falsig; Nilius, Bernd

    2007-01-01

    Transient receptor potential (TRP) channels are unique cellular sensors responding to a wide variety of extra- and intracellular signals, including mechanical and osmotic stress. In recent years, TRP channels from multiple subfamilies have been added to the list of mechano- and/or osmosensitive...... and involvement in cell volume regulation....

  3. KCNQ1 channels sense small changes in cell volume

    DEFF Research Database (Denmark)

    Grunnet, Morten; Jespersen, Thomas; MacAulay, Nanna

    2003-01-01

    . Incubation of the oocytes in cytochalasin D and experiments with truncated KCNQ1 channels suggest that KCNQ1 channels sense cell volume changes through interactions between the cytoskeleton and the N-terminus of the channel protein. From our results we propose that KCNQ1 and KCNQ4 channels play an important...

  4. Alternatives to argon for gas stopping volumes in the B194 neutron imager

    Energy Technology Data Exchange (ETDEWEB)

    Bleuel, D. L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Anderson, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Caggiano, J. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hall, J. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Johnson, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ratkiewicz, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Rusnak, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-05-17

    In a recent experiment at Lawrence Berkeley National Laboratory, the 40Ar(d,p)41Ar excitation function between 3-7 MeV was measured, confirming a previous estimation that there may be an intolerable radiation dose from 41Ar production by slowing to rest 6.74 MeV deuterons in the gas cell of the neutron imaging facility being constructed in B194. Gas alternatives to argon are considered, including helium, nitrogen (N2), neon, sulfur hexafluoride (SF6), krypton, and xenon, as well as high atomic number solid backings such as tantalum.

  5. In Situ Void Fraction and Gas Volume in Hanford Tank 241-SY-101 as Measured with the Void Fraction Instrument

    Energy Technology Data Exchange (ETDEWEB)

    CW Stewart; G Chen; JM Alzheimer; PA Meyer

    1998-11-10

    The void fraction instrument (WI) was deployed in Tank 241-SY-101 three times in 1998 to confm and locate the retained gas (void) postulated to be causing the accelerating waste level rise observed since 1995. The design, operation, and data reduction model of the WI are described along with validation testing and potential sources of uncertainty. The test plans, field observations and void measurements are described in detail, including the total gas volume calculations and the gas volume model. Based on 1998 data, the void fraction averaged 0.013 i 0.001 in the mixed slurry and 0.30 ~ 0.04 in the crust. This gives gas volumes (at standard pressure and temperature) of 87 t 9 scm in the slurry and 138 ~ 22 scm in the crust for a total retained gas volume of221 *25 scm. This represents an increase of about 74 scm in the crust and a decrease of about 34 scm in the slurry from 1994/95 results. The overall conclusion is that the gas retention is occurring mainly in the crust layer and there is very little gas in the mixed slurry and loosely settled layers below. New insights on crust behavior are also revealed.

  6. Comparing volume of fluid and level set methods for evaporating liquid-gas flows

    Science.gov (United States)

    Palmore, John; Desjardins, Olivier

    2016-11-01

    This presentation demonstrates three numerical strategies for simulating liquid-gas flows undergoing evaporation. The practical aim of this work is to choose a framework capable of simulating the combustion of liquid fuels in an internal combustion engine. Each framework is analyzed with respect to its accuracy and computational cost. All simulations are performed using a conservative, finite volume code for simulating reacting, multiphase flows under the low-Mach assumption. The strategies used in this study correspond to different methods for tracking the liquid-gas interface and handling the transport of the discontinuous momentum and vapor mass fractions fields. The first two strategies are based on conservative, geometric volume of fluid schemes using directionally split and un-split advection, respectively. The third strategy is the accurate conservative level set method. For all strategies, special attention is given to ensuring the consistency between the fluxes of mass, momentum, and vapor fractions. The study performs three-dimensional simulations of an isolated droplet of a single component fuel evaporating into air. Evaporation rates and vapor mass fractions are compared to analytical results.

  7. Little pump that could : hydraulic submersible pump tackles low pressure, low fluid volume gas wells

    Energy Technology Data Exchange (ETDEWEB)

    Ross, E.

    2008-03-15

    A new pump designed by Global Energy Services was described. The pump was designed to address problems associated with downhole pumps in coalbed methane (CBM) wells. The hydraulic submersible pump (HSP) was designed to address issues related to artificial lift gas lock and solids. The pump has been installed at 35 CBM wells in western Canada as well as at natural gas wells with low pressures and low rates of water. The HSP technology was designed for use with wells between 0.01 cubic metres and 24 cubic metres per day of water. A single joystick in the surface unit is used to determine the amount of hydraulic oil delivered to the bottomhole pump when then determines the amounts of fluid produced. A 10-slot self-flushing sand screen is used to filter out particles of sand, coal, and cement. The pump also includes a hydraulic flow control valve to control water volumes. The HSP's positive displacement design makes it suitable for use in horizontal and deviated wells. The pump technology is currently being re-designed to handle larger volumes at deeper depths. 2 figs.

  8. Large volume high-pressure cell for inelastic neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Wang, W.; Kamenev, K. V. [Centre for Science at Extreme Conditions and School of Engineering, University of Edinburgh, Edinburgh EH9 3JZ (United Kingdom); Sokolov, D. A.; Huxley, A. D. [SUPA, Centre for Science at Extreme Conditions and School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3JZ (United Kingdom)

    2011-07-15

    Inelastic neutron scattering measurements typically require two orders of magnitude longer data collection times and larger sample sizes than neutron diffraction studies. Inelastic neutron scattering measurements on pressurised samples are particularly challenging since standard high-pressure apparatus restricts sample volume, attenuates the incident and scattered beams, and contributes background scattering. Here, we present the design of a large volume two-layered piston-cylinder pressure cell with optimised transmission for inelastic neutron scattering experiments. The design and the materials selected for the construction of the cell enable its safe use to a pressure of 1.8 GPa with a sample volume in excess of 400 mm{sup 3}. The design of the piston seal eliminates the need for a sample container, thus providing a larger sample volume and reduced absorption. The integrated electrical plug with a manganin pressure gauge offers an accurate measurement of pressure over the whole range of operational temperatures. The performance of the cell is demonstrated by an inelastic neutron scattering study of UGe{sub 2}.

  9. Large volume high-pressure cell for inelastic neutron scattering

    Science.gov (United States)

    Wang, W.; Sokolov, D. A.; Huxley, A. D.; Kamenev, K. V.

    2011-07-01

    Inelastic neutron scattering measurements typically require two orders of magnitude longer data collection times and larger sample sizes than neutron diffraction studies. Inelastic neutron scattering measurements on pressurised samples are particularly challenging since standard high-pressure apparatus restricts sample volume, attenuates the incident and scattered beams, and contributes background scattering. Here, we present the design of a large volume two-layered piston-cylinder pressure cell with optimised transmission for inelastic neutron scattering experiments. The design and the materials selected for the construction of the cell enable its safe use to a pressure of 1.8 GPa with a sample volume in excess of 400 mm3. The design of the piston seal eliminates the need for a sample container, thus providing a larger sample volume and reduced absorption. The integrated electrical plug with a manganin pressure gauge offers an accurate measurement of pressure over the whole range of operational temperatures. The performance of the cell is demonstrated by an inelastic neutron scattering study of UGe2.

  10. High-Volume Production of Lightweight Multijunction Solar Cells

    Science.gov (United States)

    Youtsey, Christopher

    2015-01-01

    MicroLink Devices, Inc., has transitioned its 6-inch epitaxial lift-off (ELO) solar cell fabrication process into a manufacturing platform capable of sustaining large-volume production. This Phase II project improves the ELO process by reducing cycle time and increasing the yield of large-area devices. In addition, all critical device fabrication processes have transitioned to 6-inch production tool sets designed for volume production. An emphasis on automated cassette-to-cassette and batch processes minimizes operator dependence and cell performance variability. MicroLink Devices established a pilot production line capable of at least 1,500 6-inch wafers per month at greater than 80 percent yield. The company also increased the yield and manufacturability of the 6-inch reclaim process, which is crucial to reducing the cost of the cells.

  11. Measurement of cell volume changes by fluorescence self-quenching

    DEFF Research Database (Denmark)

    Hamann, Steffen; Kiilgaard, J.F.; Litman, Thomas

    2002-01-01

    At high concentrations, certain fluorophores undergo self-quenching, i.e., fluorescence intensity decreases with increasing fluorophore concentration. Accordingly, the self-quenching properties can be used for measuring water volume changes in lipid vesicles. In cells, quantitative determination...... of water transport using fluorescence self-quenching has been complicated by the requirement of relatively high (mM) and often toxic loading concentrations. Here we report a simple method that uses low (muM) loading concentrations of calcein-acetoxymethyl ester (calcein-AM) to obtain intracellular...... concentrations of the fluorophore calcein suitable for measurement of changes in cell water volume by self-quenching. The relationship between calcein fluorescence intensity, when excited at 490 nm (its excitation maximum), and calcein concentration was investigated in vitro and in various cultured cell types...

  12. Oil and gas technology transfer activities and potential in eight major producing states. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    1993-07-01

    In 1990, the Interstate Oil and Gas Compact Commission (the Compact) performed a study that identified the structure and deficiencies of the system by which oil and gas producers receive information about the potential of new technologies and communicate their problems and technology needs back to the research community. The conclusions of that work were that major integrated companies have significantly more and better sources of technology information than independent producers. The majors also have significantly better mechanisms for communicating problems to the research and development (R&D) community. As a consequence, the Compact recommended analyzing potential mechanisms to improve technology transfer channels for independents and to accelerate independents acceptance and use of existing and emerging technologies. Building on this work, the Compact, with a grant from the US Department Energy, has reviewed specific technology transfer organizations in each of eight major oil producing states to identify specific R&D and technology transfer organizations, characterize their existing activities, and identify potential future activities that could be performed to enhance technology transfer to oil and gas producers. The profiles were developed based on information received from organizations,follow-up interviews, site visit and conversations, and participation in their sponsored technology transfer activities. The results of this effort are reported in this volume. In addition, the Compact has also developed a framework for the development of evaluation methodologies to determine the effectiveness of technology transfer programs in performing their intended functions and in achieving desired impacts impacts in the producing community. The results of that work are provided in a separate volume.

  13. A Miniaturized Optical Sensor with Integrated Gas Cell

    NARCIS (Netherlands)

    Ayerden, N.P.; Ghaderi, M.; De Graaf, G.; Wolffenbuttel, R.F.

    2015-01-01

    The design, fabrication and characterization of a highly integrated optical gas sensor is presented. The gas cell takes up most of the space in a microspectrometer and is the only component that has so far not been miniaturized. Using the tapered resonator cavity of a linear variable optical filter

  14. Foam Based Gas Diffusion Electrodes for Reversible Alkaline Electrolysis Cells

    DEFF Research Database (Denmark)

    Allebrod, Frank; Chatzichristodoulou, Christodoulos; Mogensen, Mogens Bjerg

    2014-01-01

    cell. In the present work we demonstrate the application of hydrophobic, porous, and electro-catalytically active gas diffusion electrodes. PTFE particles and silver nanowires as electro-catalysts were used in the gas diffusion electrodes. Impedance spectroscopy and cyclic voltammetry were performed...

  15. Salinity independent volume fraction prediction in water-gas-oil multiphase flows using artificial neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Salgado, C.M.; Pereira, Claudio M.N.A.; Brandao, Luis E.B., E-mail: otero@ien.gov.b, E-mail: cmnap@ien.gov.b, E-mail: brandao@ien.gov.b [Instituto de Engenharia Nuclear (DIRA/IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Div. de Radiofarmacos

    2011-07-01

    This work investigates the response of a volume fraction prediction system for water-gas-oil multiphase flows considering variations on water salinity. The approach is based on gamma-ray pulse height distributions pattern recognition by means the artificial neural networks (ANNs). The detection system uses appropriate fan beam geometry, comprised of a dual-energy gamma-ray source and two NaI(Tl) detectors adequately positioned outside the pipe in order measure transmitted and scattered beams. An ideal and static theoretical model for annular flow regime have been developed using MCNP-X code, which was used to provide training, test and validation data for the ANN. More than 500 simulations have been done, in which water salinity have been ranged from 0 to 16% in order to cover a most practical situations. Validation tests have included values of volume fractions and water salinity different from those used in ANN training phase. The results presented here show that the proposed approach may be successfully applied to material volume fraction prediction on watergas- oil multiphase flows considering practical (real) levels of variations in water salinity. (author)

  16. Fabrication of uniformly cell-laden porous scaffolds using a gas-in-liquid templating technique.

    Science.gov (United States)

    Takei, Takayuki; Aokawa, Ryuta; Shigemitsu, Takamasa; Kawakami, Koei; Yoshida, Masahiro

    2015-11-01

    Design of porous scaffolds in tissue engineering field was challenging. Uniform immobilization of cells in the scaffolds with high porosity was essential for homogeneous tissue formation. The present study was aimed at fabricating uniformly cell-laden porous scaffolds with porosity >74% using the gas-in-liquid foam templating technique. To this end, we used gelatin, microbial transglutaminase and argon gas as a scaffold material, cross-linker of the protein and porogen of scaffold, respectively. We confirmed that a porosity of >74% could be achieved by increasing the gas volume delivered to a gelatin solution. Pore size in the scaffold could be controlled by stirring speed, stirring time and the pore size of the filter through which the gas passed. The foaming technique enabled us to uniformly immobilize a human hepatoblastoma cell line in scaffold. Engraftment efficiency of the cell line entrapped within the scaffold in nude mice was higher than that of cells in free-form. These results showed that the uniformly cell-laden porous scaffolds were promising for tissue engineering.

  17. Aquaporin expression and cell volume regulation in the SV40 immortalized rat submandibular acinar cell line.

    Science.gov (United States)

    Hansen, Ann-Kristin; Galtung, Hilde Kanli

    2007-03-01

    The amount of aquaporins present and the cellular ability to perform regulatory volume changes are likely to be important for fluid secretions from exocrine glands. In this work these phenomena were studied in an SV40 immortalized rat submandibular acinar cell line. The regulatory cell volume characteristics have not previously been determined in these cells. Cell volume regulation following hyposmotic exposure and aquaporin induction was examined with Coulter counter methodology, radioactive efflux studies, fura-2 fluorescence, and polymerase chain reaction and Western blot techniques. Cell volume regulation was inhibited by the K(+) channel antagonists quinine and BaCl(2) and the Cl(-) channel blocker 5-nitro-2-(3-phenypropylamino)benzoic acid. A concomitant increase in cellular (3)H-taurine release and Ca(2+) concentration was also observed. Chelation of both intra- and extracellular Ca(2+) with EGTA and the Ca(2+) ionophore A23187 did not, however, affect cell volume regulation. Aquaporin 5 (AQP5) mRNA and protein levels were upregulated in hyperosmotic conditions and downregulated upon return to isosmotic solutions, but were reduced by the mitogen-activated ERK-activating kinase (MEK) inhibitor U0126. A 24-h MEK inhibition also diminished hyposmotically induced cell swelling and cell volume regulation. In conclusion, it was determined that regulatory volume changes in this immortalized cell line are due to KCl and taurine efflux. In conditions that increased AQP5 levels, the cells showed a faster cell swelling and a more complete volume recovery following hyposmotic exposure. This response could be overturned by MEK inhibition.

  18. Ion channels involved in cell volume regulation: effects on migration, proliferation, and programmed cell death in non adherent EAT cells and adherent ELA cells.

    Science.gov (United States)

    Hoffmann, Else Kay

    2011-01-01

    This mini review outlines studies of cell volume regulation in two closely related mammalian cell lines: nonadherent Ehrlich ascites tumour cells (EATC) and adherent Ehrlich Lettre ascites (ELA) cells. Focus is on the regulatory volume decrease (RVD) that occurs after cell swelling, the volume regulatory ion channels involved, and the mechanisms (cellular signalling pathways) that regulate these channels. Finally, I shall also briefly review current investigations in these two cell lines that focuses on how changes in cell volume can regulate cell functions such as cell migration, proliferation, and programmed cell death.

  19. Closed system generation of dendritic cells from a single blood volume for clinical application in immunotherapy.

    Science.gov (United States)

    Elias, M; van Zanten, J; Hospers, G A P; Setroikromo, A; de Jong, M A; de Leij, L F M H; Mulder, N H

    2005-12-01

    Dendritic cells (DC) used for clinical trials should be processed on a large scale conforming to current good manufacturing practice (cGMP) guidelines. The aim of this study was to develop a protocol for clinical grade generation of immature DC in a closed-system. Aphereses were performed with the Cobe Spectra continuous flow cell separator and material was derived from one volume of blood processed. Optimisation of a 3-phase collection autoPBSC technique significantly improved the quality of the initial mononuclear cell (MNC) product. Monocytes were then enriched from MNC by immunomagnetic depletion of CD19+ B cells and CD2+ T cells and partial depletion of NK cells using the Isolex 300I Magnetic cell selector. The quality of the initial mononuclear cell product was found to determine the outcome of monocyte enrichment. Enriched monocytes were cultured in Opticyte gas-permeable containers using CellGro serum-free medium supplemented with GM-CSF and IL-4 to generate immature DC. A seeding concentration of 1 x 10(6) was found optimal in terms of DC phenotype expression, monocyte percentage in culture, and cell viability. The differentiation pattern favours day 7 for harvest of immature DC. DC recovery, viability, as well as phenotype expression after cryopreservation of immature DC was considered in this study. DC were induced to maturation and evaluated in FACS analysis for phenotype expression and proliferation assays. Mature DC were able to generate an allogeneic T-cell response as well as an anti-CMV response as detected by proliferation assays. These data indicate that the described large-scale GMP-compatible system results in the generation of stable DC derived from one volume of blood processed, which are qualitatively and quantitatively sufficient for clinical application in immunotherapeutic protocols.

  20. Radon measurement of natural gas using alpha scintillation cells.

    Science.gov (United States)

    Kitto, Michael E; Torres, Miguel A; Haines, Douglas K; Semkow, Thomas M

    2014-12-01

    Due to their sensitivity and ease of use, alpha-scintillation cells are being increasingly utilized for measurements of radon ((222)Rn) in natural gas. Laboratory studies showed an average increase of 7.3% in the measurement efficiency of alpha-scintillation cells when filled with less-dense natural gas rather than regular air. A theoretical calculation comparing the atomic weight and density of air to that of natural gas suggests a 6-7% increase in the detection efficiency when measuring radon in the cells. A correction is also applicable when the sampling location and measurement laboratory are at different elevations. These corrections to the measurement efficiency need to be considered in order to derive accurate concentrations of radon in natural gas.

  1. Mimetic Theory for Cell-Centered Lagrangian Finite Volume Formulation on General Unstructured Grids

    Energy Technology Data Exchange (ETDEWEB)

    Sambasivan, Shiv Kumar [Los Alamos National Laboratory; Shashkov, Mikhail J. [Los Alamos National Laboratory; Burton, Donald E. [Los Alamos National Laboratory; Christon, Mark A. [Los Alamos National Laboratory

    2012-07-19

    A finite volume cell-centered Lagrangian scheme for solving large deformation problems is constructed based on the hypo-elastic model and using the mimetic theory. Rigorous analysis in the context of gas and solid dynamics, and arbitrary polygonal meshes, is presented to demonstrate the ability of cell-centered schemes in mimicking the continuum properties and principles at the discrete level. A new mimetic formulation based gradient evaluation technique and physics-based, frame independent and symmetry preserving slope limiters are proposed. Furthermore, a physically consistent dissipation model is employed which is both robust and inexpensive to implement. The cell-centered scheme along with these additional new features are applied to solve solids undergoing elasto-plastic deformation.

  2. Method and system for purification of gas/liquid streams for fuel cells or electrolysis cells

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention provides in embodiments a method for purification of inlet gas/liquid streams in a fuel cell or electrolysis cell, the fuel cell or electrolysis cell comprising at least a first electrode, an electrolyte and a second electrode, the method comprising the steps of: - providing...... at least one scrubber in the gas/liquid stream at the inlet side of the first electrode of the fuel cell or electrolysis cell; and/or providing at least one scrubber in the gas/liquid stream at the inlet side of the second electrode of the fuel cell or electrolysis cell; and - purifying the gas...... with the at least one scrubber, with the proviso that the fuel cell or electrolysis cell is not a solid oxide cell....

  3. Impaired migration and cell volume regulation in aquaporin 5-deficient SPC-A1 cells.

    Science.gov (United States)

    Chen, Zhihong; Zhang, Ziqiang; Gu, Yutong; Bai, Chunxue

    2011-05-31

    Aquaporin 5 (AQP5) is widely expressed in various organ and tissues. In light of the novel oncogenic properties of aquaporins (AQPs), here we investigated the effect of AQP5 knockdown by RNAi on transmembrane osmotic water permeability, cell migration potential and cell volume regulation ability. AQP5 expression was inhibited by short hairpin RNA in SPC-A1 cells, a lung adenocarcinoma cell line. Cells loaded with a fluoroprobe (calcein-AM) were immersed in either isosmotic, hyperosmotic or hyposmotic solutions, and fluorescence intensity was recorded using confocal microscopy. These measurements were used to calculate osmotic water permeability coefficients (Pf) and to monitor regulated volume decrease (RVD). Tumor cell migration and invasion assays were performed in a modified Boyden chamber. Wound healing and colony forming ability were also tested. Although self-quenching was not found in SPC-A1 cells, we observed a linear relationship between fluorescence intensity and cell water volume, suggesting that this method is a sensitive and reproducible way to measure single-cell transmembrane water permeability. Cells in which the AQP5 gene was silenced showed a 49.4% decrease in osmotic water permeability, a 55.3% decrease in migration and a 28.4% decrease in invasion potential. In addition, RVD decreased remarkably with reduced osmotic water permeability. Our results suggest that AQP5, which mediates water permeability and thus regulates cell shape and volume, is a potentially important determinant in cell migration. Copyright © 2011 Elsevier B.V. All rights reserved.

  4. Activation of Salivary Secretion: Coupling of Cell Volume and [Ca2+]i in Single Cells

    Science.gov (United States)

    Foskett, J. Kevin; Melvin, James E.

    1989-06-01

    High-resolution differential interference contrast microscopy and digital imaging of the fluorescent calcium indicator dye fura-2 were performed simultaneously in single rat salivary gland acinar cells to examine the effects of muscarinic stimulation on cell volume and cytoplasmic calcium concentration ([Ca2+]i). Agonist stimulation of fluid secretion is initially associated with a rapid tenfold increase in [Ca2+]i as well as a substantial cell shrinkage. Subsequent changes of cell volume in the continued presence of agonist are tightly coupled to dynamic levels of [Ca2+]i, even during [Ca2+]i oscillations. Experiments with Ca2+ chelators and ionophores showed that physiological elevations of [Ca2+]i are necessary and sufficient to cause changes in cell volume. The relation between [Ca2+]i and cell volume suggests that the latter reflects the secretory state of the acinar cell. Agonist-induced changes in [Ca2+]i, by modulating specific ion permeabilities, result in solute movement into or out of the cell. The resultant cell volume changes may be important in modulating salivary secretion.

  5. Hot-gas cleanup system model development. Volume II. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Ushimaru, K.; Bennett, A.; Bekowies, P.J.

    1982-11-01

    Under Contract to the Department of Energy (DOE) through the Morgantown Energy Technology Center (METC), Flow Industries, Inc., has developed computer models to simulate the physical performance of five hot-gas cleanup devices for pressurized, fluidized-bed combustion (PFBC), combined-cycle power plants. Separate cost models have also been developed to estimate the cost of each device. The work leading to the development of these models is described in Volume I of this report. This volume contains the user's manuals for both the physical and cost models. The manuals for the physical models are given first followed by those for the cost models. Each manual is a complete and separate document. The model names and devices and their respective subroutine names are: (1) Moving Granular Bed Filter by Combustion Power Company, USRCGB, QFCOST; (2) Ceramic Bag Filter by Acurex, USRACB, QDCOST; (3) Electrostatic Granular Bed Filter by General Electric, USRGGB, QACOST; (4) Electrostatic Precipitator by Research Cottrell, USRCEP, QECOST; and (5) Electrocyclone by General Electric, USRGCY, QBCOST.

  6. Capillary gas chromatographic analysis of nerve agents using large volume injections. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Deinum, T.; Nieuwenhuy, C.

    1994-11-01

    The procedure developed at TNO-Prins Maurits Laboratory (TNO-PML) for the verification of intact organophosphorus chemical warfare agents in water samples was improved. The last step in this procedure, the laborious and non-reproducible transfer of an ethyl acetate extract onto a Tenax-adsorption tube followed by thermal desorption of the Tenax-tube, was replaced by large volume injection of the extract onto a capillary gas chromatographic system. The parameters controlling the injection of a large volume of an extract (200 ul) were investigated and optimized. As ethyl acetate caused severe problems, potential new solvents were evaluated. With the improved procedure, the nerve agents sarin, tabun, soman, diisopropyl fluorophosphate (DFP) and VX could be determined in freshly prepared water samples at pg/ml (ppt) levels. The fate of the nerve agents under study in water at two pH`s (4.8 and 6) was investigated. For VX, the pH should be adjusted before extraction. Moreover, it is worthwhile to acidify water samples to diminish hydrolysis.

  7. A MODEL TO ESTIMATE VOLUME CHANGE DUE TO RADIOLYTIC GAS BUBBLES AND THERMAL EXPANSION IN SOLUTION REACTORS

    Energy Technology Data Exchange (ETDEWEB)

    F. SOUTO; A HEGER

    2001-02-01

    Aqueous homogeneous solution reactors have been proposed for the production of medical isotopes. However, the reactivity effects of fuel solution volume change, due to formation of radiolytic gas bubbles and thermal expansion, have to be mitigated to allow steady-state operation of solution reactors. The results of the free run experiments analyzed indicate that the proposed model to estimate the void volume due to radiolytic gas bubbles and thermal expansion in solution reactors can accurately describe the observed behavior during the experiments. This void volume due to radiolytic gas bubbles and fuel solution thermal expansion can then be used in the investigation of reactivity effects in fissile solutions. In addition, these experiments confirm that the radiolytic gas bubbles are formed at a higher temperature than the fuel solution temperature. These experiments also indicate that the mole-weighted average for the radiolytic gas bubbles in uranyl fluoride solutions is about 1 {micro}m. Finally, it should be noted that another model, currently under development, would simulate the power behavior during the transient given the initial fuel solution level and density. The model is based on Monte Carlo simulation with the MCNP computer code [Briesmeister, 1997] to obtain the reactor reactivity as a function of the fuel solution density, which, in turn, changes due to thermal expansion and radiolytic gas bubble formation.

  8. Miniature fuel cells relieve gas pressure in sealed batteries

    Science.gov (United States)

    Frank, H. A.

    1971-01-01

    Miniature fuel cells within sealed silver zinc batteries consume evolved hydrogen and oxygen rapidly, preventing pressure rupturing. They do not significantly increase battery weight and they operate in all battery life phases. Complete gas pressure control requires two fuel cells during all phases of operation of silver zinc batteries.

  9. Volume regulation and shape bifurcation in the cell nucleus.

    Science.gov (United States)

    Kim, Dong-Hwee; Li, Bo; Si, Fangwei; Phillip, Jude M; Wirtz, Denis; Sun, Sean X

    2015-09-15

    Alterations in nuclear morphology are closely associated with essential cell functions, such as cell motility and polarization, and correlate with a wide range of human diseases, including cancer, muscular dystrophy, dilated cardiomyopathy and progeria. However, the mechanics and forces that shape the nucleus are not well understood. Here, we demonstrate that when an adherent cell is detached from its substratum, the nucleus undergoes a large volumetric reduction accompanied by a morphological transition from an almost smooth to a heavily folded surface. We develop a mathematical model that systematically analyzes the evolution of nuclear shape and volume. The analysis suggests that the pressure difference across the nuclear envelope, which is influenced by changes in cell volume and regulated by microtubules and actin filaments, is a major factor determining nuclear morphology. Our results show that physical and chemical properties of the extracellular microenvironment directly influence nuclear morphology and suggest that there is a direct link between the environment and gene regulation. © 2015. Published by The Company of Biologists Ltd.

  10. A model to estimate volume change due to radiolytic gas bubbles and thermal expansion in solution reactors

    Energy Technology Data Exchange (ETDEWEB)

    Souto, F.J. [NIS-6: Advanced Nuclear Technology, Los Alamos National Lab., Los Alamos, NM (United States); Heger, A.S. [ESA-EA: Engineering Sciences and Application, Los Alamos National Lab., Los Alamos, NM (United States)

    2001-07-01

    To investigate the effects of radiolytic gas bubbles and thermal expansion on the steady-state operation of solution reactors at the power level required for the production of medical isotopes, a calculational model has been developed. To validate this model, including its principal hypotheses, specific experiments at the Los Alamos National Laboratory SHEBA uranyl fluoride solution reactor were conducted. The following sections describe radiolytic gas generation in solution reactors, the equations to estimate the fuel solution volume change due to radiolytic gas bubbles and thermal expansion, the experiments conducted at SHEBA, and the comparison of experimental results and model calculations. (author)

  11. Malignant human cell transformation of Marcellus shale gas drilling flow back water

    Science.gov (United States)

    Yao, Yixin; Chen, Tingting; Shen, Steven S.; Niu, Yingmei; DesMarais, Thomas L; Linn, Reka; Saunders, Eric; Fan, Zhihua; Lioy, Paul; Kluz, Thomas; Chen, Lung-Chi; Wu, Zhuangchun; Costa, Max

    2015-01-01

    The rapid development of high-volume horizontal hydraulic fracturing for mining natural gas from shale has posed potential impacts on human health and biodiversity. The produced flow back waters after hydraulic stimulation is known to carry high levels of saline and total dissolved solids. To understand the toxicity and potential carcinogenic effects of these waste waters, flow back water from five Marcellus hydraulic fracturing oil and gas wells were analyzed. The physicochemical nature of these samples was analyzed by inductively coupled plasma mass spectrometry and scanning electron microscopy / energy dispersive X-ray spectroscopy. A cytotoxicity study using colony formation as the endpoint was carried out to define the LC50 values of test samples using human bronchial epithelial cells (BEAS-2B). The BEAS-2B cell transformation assay was employed to assess the carcinogenic potential of the samples. Barium and strontium were among the most abundant metals in these samples and the same metals were found elevated in BEAS-2B cells after long-term treatment. BEAS-2B cells treated for 6 weeks with flow back waters produced colony formation in soft agar that was concentration dependant. In addition, flow back water-transformed BEAS-2B cells show a better migration capability when compared to control cells. This study provides information needed to assess the potential health impact of post-hydraulic fracturing flow back waters from Marcellus Shale natural gas mining. PMID:26210350

  12. Automated three-dimensional single cell phenotyping of spindle dynamics, cell shape, and volume

    CERN Document Server

    Plumb, Kemp; Pelletier, Vincent; Kilfoil, Maria L

    2015-01-01

    We present feature finding and tracking algorithms in 3D in living cells, and demonstrate their utility to measure metrics important in cell biological processes. We developed a computational imaging hybrid approach that combines automated three-dimensional tracking of point-like features with surface determination from which cell (or nuclear) volume, shape, and planes of interest can be extracted. After validation, we applied the technique to real space context-rich dynamics of the mitotic spindle, and cell volume and its relationship to spindle length, in dividing living cells. These methods are additionally useful for automated segregation of pre-anaphase and anaphase spindle populations in budding yeast. We found that genetic deletion of the yeast kinesin-5 mitotic motor cin8 leads to large mother and daughter cells that were indistinguishable based on size, and that in those cells the spindle length becomes uncorrelated with cell size. The technique can be used to visualize and quantify tracked feature c...

  13. Gas-foaming calcium phosphate cement scaffold encapsulating human umbilical cord stem cells.

    Science.gov (United States)

    Chen, Wenchuan; Zhou, Hongzhi; Tang, Minghui; Weir, Michael D; Bao, Chongyun; Xu, Hockin H K

    2012-04-01

    Tissue engineering approaches are promising to meet the increasing need for bone regeneration. Calcium phosphate cement (CPC) can be injected and self-set to form a scaffold with excellent osteoconductivity. The objectives of this study were to develop a macroporous CPC-chitosan-fiber construct containing alginate-fibrin microbeads encapsulating human umbilical cord mesenchymal stem cells (hUCMSCs) and to investigate hUCMSC release from the degrading microbeads and proliferation inside the porous CPC construct. The hUCMSC-encapsulated microbeads were completely wrapped inside the CPC paste, with the gas-foaming porogen creating macropores in CPC to provide for access to culture media. Increasing the porogen content in CPC significantly increased the cell viability, from 49% of live cells in CPC with 0% porogen to 86% of live cells in CPC with 15% porogen. The alginate-fibrin microbeads started to degrade and release the cells inside CPC at 7 days. The released cells started to proliferate inside the macroporous CPC construct. The live cell number inside CPC increased from 270 cells/mm(2) at 1 day to 350 cells/mm(2) at 21 days. The pore volume fraction of CPC increased from 46.8% to 78.4% using the gas-foaming method, with macropore sizes of approximately 100 to 400 μm. The strength of the CPC-chitosan-fiber scaffold at 15% porogen was 3.8 MPa, which approximated the reported 3.5 MPa for cancellous bone. In conclusion, a novel gas-foaming macroporous CPC construct containing degradable alginate-fibrin microbeads was developed that encapsulated hUCMSCs. The cells had good viability while wrapped inside the porous CPC construct. The degradable microbeads in CPC quickly released the cells, which proliferated over time inside the porous CPC. Self-setting, strong CPC with alginate-fibrin microbeads for stem cell delivery is promising for bone tissue engineering applications.

  14. Enhanced recovery of unconventional gas. Volume II. The program. [Tight gas basins; Devonian shale; coal seams; geopressured aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Kuuskraa, V.A.; Brashear, J.P.; Doscher, T.M.; Elkins, L.E.

    1978-10-01

    This study was conducted to assist public decision-makers in selecting among many choices to obtain new gas supplies by addressing 2 questions: 1) how severe is the need for additional future supplies of natural gas, and what is the economic potential of providing part of future supply through enhanced recovery from unconventional natural gas resources. The study also serves to assist the DOE in designing a cost-effective R and D program to stimulate industry to recover this unconventional gas and to produce it sooner. Tight gas basins, Devonian shale, methane from coal seams, and methane from geopressured aquifers are considered. It is concluded that unconventional sources, already providing about 1 Tcf per year, could provide from 3 to 4 Tcf in 1985 and from 6 to 8 Tcf in 1990 (at $1.75 and $3.00 per Mcf, respectively). However, even with these additions to supply, gas supply is projected to remain below 1977 usage levels. (DLC)

  15. Gas dispersion and immobile gas volume in solid and porous particle biofilter materials at low air flow velocities.

    Science.gov (United States)

    Sharma, Prabhakar; Poulsen, Tjalfe G

    2010-07-01

    Gas-phase dispersion in granular biofilter materials with a wide range of particle sizes was investigated using atmospheric air and nitrogen as tracer gases. Two types of materials were used: (1) light extended clay aggregates (LECA), consisting of highly porous particles, and (2) gravel, consisting of solid particles. LECA is a commercial material that is used for insulation, as a soil conditioner, and as a carrier material in biofilters for air cleaning. These two materials were selected to have approximately the same particle shape. Column gas transport experiments were conducted for both materials using different mean particle diameters, different particle size ranges, and different gas flow velocities. Measured breakthrough curves were modeled using the advection-dispersion equation modified for mass transfer between mobile and immobile gas phases. The results showed that gas dispersivity increased with increasing mean particle diameter for LECA but was independent of mean particle diameter for gravel. Gas dispersivity also increased with increasing particle size range for both media. Dispersivities in LECA were generally higher than for gravel. The mobile gas content in both materials increased with increasing gas flow velocity but it did not show any strong dependency on mean particle diameter or particle size range. The relative fraction of mobile gas compared with total porosity was highest for gravel and lowest for LECA likely because of its high internal porosity.

  16. A recoverable gas-cell diagnostic for the National Ignition Facility

    Science.gov (United States)

    Ratkiewicz, A.; Berzak Hopkins, L.; Bleuel, D. L.; Bernstein, L. A.; van Bibber, K.; Cassata, W. S.; Goldblum, B. L.; Siem, S.; Velsko, C. A.; Wiedeking, M.; Yeamans, C. B.

    2016-11-01

    The high-fluence neutron spectrum produced by the National Ignition Facility (NIF) provides an opportunity to measure the activation of materials by fast-spectrum neutrons. A new large-volume gas-cell diagnostic has been designed and qualified to measure the activation of gaseous substances at the NIF. This in-chamber diagnostic is recoverable, reusable and has been successfully fielded. Data from the qualification of the diagnostic have been used to benchmark an Monte Carlo N-Particle Transport Code simulation describing the downscattered neutron spectrum seen by the gas cell. We present early results from the use of this diagnostic to measure the activation of natXe and discuss future work to study the strength of interactions between plasma and nuclei.

  17. A recoverable gas-cell diagnostic for the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Ratkiewicz, A., E-mail: ratkiewicz1@llnl.gov; Berzak Hopkins, L.; Bleuel, D. L.; Cassata, W. S.; Velsko, C. A.; Yeamans, C. B. [Lawrence Livermore National Laboratory, Livermore, California 95440 (United States); Bernstein, L. A.; Bibber, K. van; Goldblum, B. L. [University of California, Berkeley, California 94720 (United States); Siem, S. [University of Oslo, N-0316 Oslo (Norway); Wiedeking, M. [iThemba LABS, Somerset West 7129 (South Africa)

    2016-11-15

    The high-fluence neutron spectrum produced by the National Ignition Facility (NIF) provides an opportunity to measure the activation of materials by fast-spectrum neutrons. A new large-volume gas-cell diagnostic has been designed and qualified to measure the activation of gaseous substances at the NIF. This in-chamber diagnostic is recoverable, reusable and has been successfully fielded. Data from the qualification of the diagnostic have been used to benchmark an Monte Carlo N-Particle Transport Code simulation describing the downscattered neutron spectrum seen by the gas cell. We present early results from the use of this diagnostic to measure the activation of {sup nat}Xe and discuss future work to study the strength of interactions between plasma and nuclei.

  18. Composition and Temperature Dependence of Excess Volume of Heavy Oil-Stocks Mixtures + (Gas oil or Toluene or Reformate

    Directory of Open Access Journals (Sweden)

    Shahad Z. Atta

    2011-01-01

    Full Text Available Binary mixtures of three, heavy oil-stocks was subjected to density measurements at temperatures of 30, 35 and 40 °C. and precise data was acquired on the volumetric behavior of these systems. The results are reported in terms of equations for excess specific volumes of mixtures. The heavy oil-stocks used were of good varity, namely 40 stock, 60 stock, and 150 stock. The lightest one is 40 stock with API gravity 33.69 while 60 stock is a middle type and 150 stock is a heavy one, with API gravity 27.74 and 23.79 respectively. Temperatures in the range of 30-40 °C have a minor effect on excess volume of heavy oil-stock binary mixture thus, insignificant expansion or shrinkage is observed by increasing the temperature this effect becomes more significant although the heavy oil-stocks is spiked with hydrocarbons like (gas oil, toluene and reformate. Blending of Heavy oil-stocks with hydrocarbons spikes (gas oil, toluene and reformate form non-ideal mixtures, for which excess volume can be positive or negative depending on nature species. Spiking of Heavy oil-stocks with either gas oil or reformate resulted in negative excess volume. This shrinkage is greater for the lowest boiling point spike as in the case of reformate, While, the presence of methyl groups in aromatic rings results in a positive excess volume, as shown in toluene when blended with 40 stock but a negative excess volume was found when blended with 60 stock and 150 stock. The API gravity of heavy oil-stocks has an effect on excess volume when the oil-stocks spiked with hydrocarbons like (gas oil, toluene and reformate. This 40 stocks as a typical light types resulted in minimum negative excess volume of -0.47 at 30 °C, when it was spiked with the gas oil; while the spiked heavy oil-stock with kerosene shows a maximum excess volume of -15.56 at 40 °C.

  19. Foam Based Gas Diffusion Electrodes for Reversible Alkaline Electrolysis Cells

    DEFF Research Database (Denmark)

    Allebrod, Frank; Chatzichristodoulou, Christodoulos; Mogensen, Mogens Bjerg

    2014-01-01

    Alkaline electrolysis cells operated at 250 °C and 40 bar have shown to be able to convert electrical energy into chemical energy in the form of hydrogen at very high efficiencies and power densities. Foam based gas diffusion electrodes and a liquid immobilized electrolyte allow the operation...... of the newly designed electrolysis cell as a fuel cell, but condensation of steam may lead to blocked pores, thereby inhibiting gas diffusion and decreasing the performance of the cell. In the here presented work we present the application of a hydrophobic, porous, and electro-catalytically active layer...... the electrochemical characteristics of the cell. The thickness of the electrolyte matrix was reduced to 200 µm, thereby achieving a serial resistance and area specific resistance as low as 60 mΩ cm2 and 150 mΩ cm2, respectively, at a temperature of 200 °C and 20 bar pressure. A new production method was developed...

  20. Aquaporin 2-increased renal cell proliferation is associated with cell volume regulation.

    Science.gov (United States)

    Di Giusto, Gisela; Flamenco, Pilar; Rivarola, Valeria; Fernández, Juan; Melamud, Luciana; Ford, Paula; Capurro, Claudia

    2012-12-01

    We have previously demonstrated that in renal cortical collecting duct cells (RCCD(1)) the expression of the water channel Aquaporin 2 (AQP2) raises the rate of cell proliferation. In this study, we investigated the mechanisms involved in this process, focusing on the putative link between AQP2 expression, cell volume changes, and regulatory volume decrease activity (RVD). Two renal cell lines were used: WT-RCCD(1) (not expressing aquaporins) and AQP2-RCCD(1) (transfected with AQP2). Our results showed that when most RCCD(1) cells are in the G(1)-phase (unsynchronized), the blockage of barium-sensitive K(+) channels implicated in rapid RVD inhibits cell proliferation only in AQP2-RCCD(1) cells. Though cells in the S-phase (synchronized) had a remarkable increase in size, this enhancement was higher and was accompanied by a significant down-regulation in the rapid RVD response only in AQP2-RCCD(1) cells. This decrease in the RVD activity did not correlate with changes in AQP2 function or expression, demonstrating that AQP2-besides increasing water permeability-would play some other role. These observations together with evidence implying a cell-sizing mechanism that shortens the cell cycle of large cells, let us to propose that during nutrient uptake, in early G(1), volume tends to increase but it may be efficiently regulated by an AQP2-dependent mechanism, inducing the rapid activation of RVD channels. This mechanism would be down-regulated when volume needs to be increased in order to proceed into the S-phase. Therefore, during cell cycle, a coordinated modulation of the RVD activity may contribute to accelerate proliferation of cells expressing AQP2. Copyright © 2012 Wiley Periodicals, Inc.

  1. Determination of cell electroporation in small-volume samples.

    Science.gov (United States)

    Saulis, Gintautas; Praneviciŭte, Rita

    2007-01-01

    Expose of cells to electric field pulses increases the cell membrane permeability. Intracellular potassium ions leak out of the cells through aqueous pores created in the membrane. This release is used here for the determination of the fraction of electroporated cells. To determine cell membrane electroporation in small-volume samples (40-50 miacrol), mini both potassium ion-selective and reference electrodes, with tip diameters of 1-1.5 mm and minimum immersion depths of 1 mm, were utilized. The obtained calibration graph was linear within the concentration range 0.2-100 mM. The slope was 50-51 and 53-56 mV per concentration order at 10-11 and 19-21 degrees C, respectively. Detection limit of the electrode was determined to be 0.05-0.08 mM, however, it was possible to work down to concentrations in the range of 0.01 mM. Experiments have been carried out on human erythrocytes exposed to a square-wave electric pulse with the duration of 0.1-2 ms. The extracellular potassium concentrations were in the range between 0.04-0.08 mM (intact cells) and 3-5 mM (100% electroporation). The obtained dependences of the fraction of electroporated cells on the pulse intensity were of a sigmoid shape. The dependence of the pulse amplitude required to electroporate 50% of cells on the pulse duration, obtained from the release of intracellular potassium ions, coincided with the one determined from the extent of hemolysis after 24 h-incubation at low temperature.

  2. Final environmental information volume for the coke oven gas cleaning project at the Bethlehem Steel Corporation Sparrows Point Plant

    Energy Technology Data Exchange (ETDEWEB)

    1990-04-24

    Bethelehem Steel Corporation (BSC) is planning to conduct a demonstration project involving an integrated system that can be retrofitted into coke oven gas handling systems to address a variety of environmental and operational factors in a more cost-effective manner. Successful application of this technology to existing US coke plants could: (1) reduce emissions of sulfur dioxide, cyanide, and volatile organic compounds (including benzene) (2) reduce the cost and handling of processing feed chemicals, (3) disposal costs of nuisance by-products and (4) increase reliability and reduce operation/maintenance requirements for coke oven gas desulfurization systems. The proposed system will remove sulfur from the coke oven gas in the form of hydrogen sulfide using the ammonia indigenous to the gas as the primary reactive chemical. Ammonia and hydrogen cyanide are also removed in this process. The hydrogen sulfide removed from the coke oven gas in routed to a modified Claus plant for conversion to a saleable sulfur by-product. Ammonia and hydrogen cyanide will be catalytically converted to hydrogen, nitrogen, carbon dioxide, and carbon monoxide. The tail gas from the sulfur recovery unit is recycled to the coke oven gas stream, upstream of the new gas cleaning system. The proposed demonstration project will be installed at the existing coke oven facilities at BSC's Sparrows Point Plant. This volume describes the proposed actions and the resulting environmental impacts. 21 refs., 19 figs., 9 tabs.

  3. Note: Real-time monitoring via second-harmonic interferometry of a flow gas cell for laser wakefield acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Brandi, F., E-mail: fernando.brandi@ino.it [Intense Laser Irradiation Laboratory (ILIL), Istituto Nazionale di Ottica (INO-CNR), Via Moruzzi 1, 56124 Pisa (Italy); Istituto Italiano di Tecnologia (IIT), Via Morego 30, 16163 Genova (Italy); Giammanco, F.; Conti, F. [Dipartimento di Fisica, Università degli Studi di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Plasma Diagnostics and Technologies Ltd., via Matteucci n.38/D, 56124 Pisa (Italy); Sylla, F. [SourceLAB SAS, 86 Rue de Paris, 91400 Orsay (France); Lambert, G. [LOA, ENSTA ParisTech, CNRS, Ecole Polytechnique, Université Paris-Saclay, 828 bd des Maréchaux, 91762 Palaiseau Cedex (France); Gizzi, L. A. [Intense Laser Irradiation Laboratory (ILIL), Istituto Nazionale di Ottica (INO-CNR), Via Moruzzi 1, 56124 Pisa (Italy)

    2016-08-15

    The use of a gas cell as a target for laser wakefield acceleration (LWFA) offers the possibility to obtain stable and manageable laser-plasma interaction process, a mandatory condition for practical applications of this emerging technique, especially in multi-stage accelerators. In order to obtain full control of the gas particle number density in the interaction region, thus allowing for a long term stable and manageable LWFA, real-time monitoring is necessary. In fact, the ideal gas law cannot be used to estimate the particle density inside the flow cell based on the preset backing pressure and the room temperature because the gas flow depends on several factors like tubing, regulators, and valves in the gas supply system, as well as vacuum chamber volume and vacuum pump speed/throughput. Here, second-harmonic interferometry is applied to measure the particle number density inside a flow gas cell designed for LWFA. The results demonstrate that real-time monitoring is achieved and that using low backing pressure gas (<1 bar) and different cell orifice diameters (<2 mm) it is possible to finely tune the number density up to the 10{sup 19} cm{sup −3} range well suited for LWFA.

  4. Production decline analysis for a multi-fractured horizontal well considering elliptical reservoir stimulated volumes in shale gas reservoirs

    Science.gov (United States)

    Wei, Mingqiang; Duan, Yonggang; Fang, Quantang; Zhang, Tiantian

    2016-06-01

    Multi-fractured horizontal wells (MFHWs) are an effective technique for developing shale gas reservoirs. After fracturing, stimulated reservoir volumes (SRVs) invariably exist around the wellbore. In this paper, a composite elliptical SRV model for each hydraulic fracturing stage is established, based on micro-seismic events. Both the SRV and the outer regions are assumed as single-porosity media with different formation physical parameters. Based on unstructured perpendicular bisection (PEBI) grids, a mathematical model considering Darcy flow, diffusion and adsorption/desorption in shale gas reservoirs is presented. The numerical solution is obtained by combining the control volume finite element method with the fully implicit method. The model is verified by a simplified model solution. The MFHW Blasingame production decline curves, which consider elliptical SRVs in shale gas reservoirs, are plotted by computer programming. The flow regions can be divided into five flow regimes: early formation linear flow, radial flow in the SRV region, transient flow, pseudo radial flow and boundary dominated flow. Finally, the effect of six related parameters, including the SRV area size, outer region permeability, SRV region permeability, Langmuir pressure, Langmuir volume and diffusion coefficient, are analyzed on type curves. The model presented in this paper can expand our understanding of MFHW production decline behaviors in shale gas reservoirs and can be applied to estimate reservoir properties, the SRV area, and reserves in these types of reservoirs by type curve matching.

  5. FUEL CELL OPERATION ON LANDFILL GAS AT PENROSE POWER STATION

    Science.gov (United States)

    This demonstration test successfully demonstrated operation of a commercial phosphoric acid fuel cell (FC) on landfill gas (LG) at the Penrose Power Station in Sun Valley, CA. Demonstration output included operation up to 137 kW; 37.1% efficiency at 120 kW; exceptionally low sec...

  6. TEST RESULTS FOR FUEL CELL OPERATION ON ANAEROBIC DIGESTER GAS

    Science.gov (United States)

    EPA, in conjunction with ONSI Corp., embarked on a project to define, design, test, and assess a fuel cell energy recovery system for application at anaerobic digester waste water (sewage) treatment plants. Anaerobic digester gas (ADG) is produced at these plants during the proce...

  7. Hot gas flow cell for optical measurements on reactive gases

    DEFF Research Database (Denmark)

    Grosch, Helge; Fateev, Alexander; Nielsen, Karsten Lindorff

    2013-01-01

    was validated for high resolution measurements at temperatures of up to 800 K (527 degrees C) in the ultraviolet (UV) and infrared (IR) regions (190-20 000 nm). Verification of the gas temperature in the cell is provided by a thermocouple and emission/transmission measurements in the IR and UV regions. High...

  8. Design, Construction and Performance Tests of a Prototype MicroMegas Chamber with Two Readout Planes in a Common Gas Volume

    CERN Document Server

    Brickwedde, Bernard; Schott, Matthias; Yildirim, Eda

    2016-01-01

    In this paper, the design and the performance of a prototype detector based on MicroMegas technology with two detection planes in a common gas volume is discussed. The detector is suited for the forward region of LHC detectors, addressing the high-rate environment and limited available space. Each detection plane has an active area of 9x9 cm^2 with a two-dimensional strip readout and is separated by a common gas region with a height of 14 mm. A micro-mesh, working as a cathode, is placed in the middle of the common gas volume separating it into two individual cells. This setup allows for an angle reconstruction of incoming particles with a precision of 2 mrad. Since this design reduces the impact of multiple scattering effects by the reduced material budget, possible applications for low energy beam experiments can be envisioned. The performance of the prototype detector has been tested with a 4.4 GeV electron beam, provided by the test beam facility at DESY.

  9. Cell volume regulation in cultured human retinal Muller cells is associated with changes in transmembrane potential.

    Directory of Open Access Journals (Sweden)

    Juan M Fernández

    Full Text Available Müller cells are mainly involved in controlling extracellular homeostasis in the retina, where intense neural activity alters ion concentrations and osmotic gradients, thus favoring cell swelling. This increase in cell volume is followed by a regulatory volume decrease response (RVD, which is known to be partially mediated by the activation of K(+ and anion channels. However, the precise mechanisms underlying osmotic swelling and subsequent cell volume regulation in Müller cells have been evaluated by only a few studies. Although the activation of ion channels during the RVD response may alter transmembrane potential (Vm, no studies have actually addressed this issue in Müller cells. The aim of the present work is to evaluate RVD using a retinal Müller cell line (MIO-M1 under different extracellular ionic conditions, and to study a possible association between RVD and changes in Vm. Cell volume and Vm changes were evaluated using fluorescent probe techniques and a mathematical model. Results show that cell swelling and subsequent RVD were accompanied by Vm depolarization followed by repolarization. This response depended on the composition of extracellular media. Cells exposed to a hypoosmotic solution with reduced ionic strength underwent maximum RVD and had a larger repolarization. Both of these responses were reduced by K(+ or Cl(- channel blockers. In contrast, cells facing a hypoosmotic solution with the same ionic strength as the isoosmotic solution showed a lower RVD and a smaller repolarization and were not affected by blockers. Together, experimental and simulated data led us to propose that the efficiency of the RVD process in Müller glia depends not only on the activation of ion channels, but is also strongly modulated by concurrent changes in the membrane potential. The relationship between ionic fluxes, changes in ion permeabilities and ion concentrations -all leading to changes in Vm- define the success of RVD.

  10. Large-volume constant-concentration sampling technique coupling with surface-enhanced Raman spectroscopy for rapid on-site gas analysis

    Science.gov (United States)

    Zhang, Zhuomin; Zhan, Yisen; Huang, Yichun; Li, Gongke

    2017-08-01

    In this work, a portable large-volume constant-concentration (LVCC) sampling technique coupling with surface-enhanced Raman spectroscopy (SERS) was developed for the rapid on-site gas analysis based on suitable derivatization methods. LVCC sampling technique mainly consisted of a specially designed sampling cell including the rigid sample container and flexible sampling bag, and an absorption-derivatization module with a portable pump and a gas flowmeter. LVCC sampling technique allowed large, alterable and well-controlled sampling volume, which kept the concentration of gas target in headspace phase constant during the entire sampling process and made the sampling result more representative. Moreover, absorption and derivatization of gas target during LVCC sampling process were efficiently merged in one step using bromine-thiourea and OPA-NH4+ strategy for ethylene and SO2 respectively, which made LVCC sampling technique conveniently adapted to consequent SERS analysis. Finally, a new LVCC sampling-SERS method was developed and successfully applied for rapid analysis of trace ethylene and SO2 from fruits. It was satisfied that trace ethylene and SO2 from real fruit samples could be actually and accurately quantified by this method. The minor concentration fluctuations of ethylene and SO2 during the entire LVCC sampling process were proved to be samples were achieved in range of 95.0-101% and 97.0-104% respectively. It is expected that portable LVCC sampling technique would pave the way for rapid on-site analysis of accurate concentrations of trace gas targets from real samples by SERS.

  11. Large-volume constant-concentration sampling technique coupling with surface-enhanced Raman spectroscopy for rapid on-site gas analysis.

    Science.gov (United States)

    Zhang, Zhuomin; Zhan, Yisen; Huang, Yichun; Li, Gongke

    2017-08-05

    In this work, a portable large-volume constant-concentration (LVCC) sampling technique coupling with surface-enhanced Raman spectroscopy (SERS) was developed for the rapid on-site gas analysis based on suitable derivatization methods. LVCC sampling technique mainly consisted of a specially designed sampling cell including the rigid sample container and flexible sampling bag, and an absorption-derivatization module with a portable pump and a gas flowmeter. LVCC sampling technique allowed large, alterable and well-controlled sampling volume, which kept the concentration of gas target in headspace phase constant during the entire sampling process and made the sampling result more representative. Moreover, absorption and derivatization of gas target during LVCC sampling process were efficiently merged in one step using bromine-thiourea and OPA-NH4(+) strategy for ethylene and SO2 respectively, which made LVCC sampling technique conveniently adapted to consequent SERS analysis. Finally, a new LVCC sampling-SERS method was developed and successfully applied for rapid analysis of trace ethylene and SO2 from fruits. It was satisfied that trace ethylene and SO2 from real fruit samples could be actually and accurately quantified by this method. The minor concentration fluctuations of ethylene and SO2 during the entire LVCC sampling process were proved to be samples were achieved in range of 95.0-101% and 97.0-104% respectively. It is expected that portable LVCC sampling technique would pave the way for rapid on-site analysis of accurate concentrations of trace gas targets from real samples by SERS. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Listening to Ambrym Volcano (Vanuatu) By an Acoustic Array: Cyclictity in Gas Volume at an Open Vent Volcano

    Science.gov (United States)

    Vergniolle, S.; Zielinski, C.; Bani, P.; Lardy, M.; LE Pichon, A.; Millier, P.; Herry, P.; Todman, S.; Garaebiti, E.

    2014-12-01

    Volcanic activity at Ambrym volcano (Vanuatu) is currently characterised by continuous lava lake activity within two main cones (Marum and Benbow), distant by 3 km. Acoustic measurements were performed by an acoustic array set at a distance of 3 km from the active vents between April 2009 and January 2010. The detection of volcanic signals, done by using PMCC (progressive multi-channel correlation), showed that more than 97 % of the detections came from one of the active vents, with millions of acoustic transients and no quiescent period. Two short Strombolian phases and 3 isolated explosions existed at Marum during this period while no strong signal was detected at Benbow. The active degassing, i.e. that detected by acoustic measurements, is mostly around 1 Hz at both vents. The gas volume is estimated from calculating acoustic power for each detection in the 0.8-2 Hz frequency range, assuming that the source has a constant radius of 5 m. The gas volume expelled per hour is similar at Benbow and Marum with 0.5-4 Mm^3. One striking observation is the existence of regular alternations between periods with high and small expelled gas volume, with 3 Mm^3 per hour and 0.5 Mm^3 per hour for each period, respectively. The detection of acoustic pulses even small, which is done with wavelet analysis, showed rapid and regular variations in the number of acoustic transients (1-460). The duration, return time and expelled gas volume were similar at Benbow and Marum on the 50 and 38 recognised cycles, respectively. The duration, return time and expelled gas volume at Benbow were equal to 58 hr, 70 hr and 42 Mm^3, respectively. Their relative small standart deviation for the above parameters, equal to 24 hr, 82 hr and 26 Mm^3 respectively, suggested that the fluctuations between periods with high and low gas volume, is probably cyclic. This 5 days-cyclicity could be perhaps be related to thermal convection processes in the magma reservoir.

  13. Natural gas large volumes measurement: going for on-line custody transfer; Medicao de grandes volumes de gas natural: rumo a transferencia de custodia on-line

    Energy Technology Data Exchange (ETDEWEB)

    Mercon, Eduardo G.; Frisoli, Caetano [PETROBRAS Transporte S.A. (TRANSPETRO), Rio de Janeiro, RJ (Brazil)

    2005-07-01

    This paper describes the structure of the natural gas flow measurement process in TRANSPETRO, and comments features and performance of existing or under-implantation equipment and systems, reviewing best practices and technology in use. This process runs through three interrelated segments: data flow measurement, strictly speaking; data transfer and acquisition; and data flow measurement certification (data consolidation to invoice). Initially, the work makes an approach to the data flow measurement segment, evaluating technical features of flow meters, and describing configurations and functions of the operating gas flow computers in TRANSPETRO's custody transfer stations. In this part it will also be presented the implantation of TRANSPETRO's system for gas chromatography data input on-line to flow computers. Further, in data transfer and acquisition, SCADA system technical aspects will be evaluated, considering communications protocols and programmable logic controllers functions in remote terminal units, and discussing their places in the measurement process. Additionally, TRANSPETRO's experience in data measurement certification tools is in discussion, as well as new upcoming tools and their potential features, from what new practices will be suggested. Finally, all the work has been conceived and carried out always aiming to the state-of-the-art technology in gas flow measurement: on-line custody transfer. (author)

  14. A Miniaturized Prototype of Resonant Banana-Shaped Photoacoustic Cell for Gas Sensing

    CERN Document Server

    Ulasevich, A L; Kouzmouk, A A; Starovoitov, V S

    2013-01-01

    A resonant photoacoustic cell intended for laser-spectroscopy gas sensing is represented. This cell is a miniature imitation of a macro-scale banana-shaped cell developed previously. The parameters, which specify the cavity shape, are chosen so as not only to provide optimal cell operation at a selected acoustic resonance but also to reduce substantially the cell sizes. A miniaturized prototype cell (the volume of acoustic cavity of ~ 5 mm^3) adapted to the narrow diffraction-limited beam of near-infrared laser is produced and examined experimentally. The noise-associated measurement error and laser-initiated signals are studied as functions of modulation frequency. The background signal and the useful response to light absorption by the gas are analyzed in measurements of absorption for ammonia in nitrogen flow with the help of a pigtailed DFB laser diode oscillated near a wavelength of 1.53 um. The performance of prototype operation at the second longitudinal acoustic resonance (the resonance frequency of ~...

  15. U S Navy Diving Manual. Volume 2. Mixed-Gas Diving. Revision 1.

    Science.gov (United States)

    1981-07-01

    APPENDIX A- MK 12 MIXED-GAS DIVING OUTFIT D.3 D-5 MK 6 MOO 0 MXD-GAS SCUBA A-1 Diving Equipment Preparation D-5 Ps,-O4X ’ IpIP W Popmom Mixed-Gas Supply... Ocean Simulation Facility at Panama City, Fl. bell; and to 300 feet using helium-oxygen breathing gas mixtures as the breathing me- dium with the

  16. Method and system for purification of gas/liquid streams for fuel cells or electrolysis cells

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention provides in embodiments a method for purification of inlet gas/liquid streams in a fuel cell or electrolysis cell, the fuel cell or electrolysis cell comprising at least a first electrode, an electrolyte and a second electrode, the method comprising the steps of: - providing...... at least one scrubber in the gas/liquid stream at the inlet side of the first electrode of the fuel cell or electrolysis cell; and/or providing at least one scrubber in the gas/liquid stream at the inlet side of the second electrode of the fuel cell or electrolysis cell; and - purifying the gas/liquid...... streams towards the first and second electrode; wherein the at least one scrubber in the gas/liquid stream at the inlet side of the first electrode and/or the at least one scrubber in the gas/liquid stream at the inlet side of the second electrode comprises a material suitable as an electrolyte material...

  17. Regulation of Cytoplasmic and Vacuolar Volumes by Plant Cells in Suspension Culture

    DEFF Research Database (Denmark)

    Owens, Trevor; Poole, Ronald J

    1979-01-01

    Quantitative microscopical measurements have been made of the proportion of cell volume occupied by cytoplasm in a cell suspension culture derived from cotyledons of bush bean (cv. Contender). On a 7-day culture cycle, the content of cytoplasm varies from 25% at the time of transfer to 45......% at the start of the phase of rapid cell division. If the culture is continued beyond 7 days, the vacuole volume reaches 90% of cell volume by day 12.Attempts to measure relative cytoplasmic volumes by compartmental analysis of nonelectrolyte efflux were unsuccessful. The proportion of cell volume occupied...... by cytoplasm is roughly correlated with protein content, but shows no correlation with cell size or with intracellular concentrations of K or Na. The most striking observation is that the growth of cytoplasmic volume for the culture as a whole appears to be constant throughout the culture cycle, despite...

  18. Native and enzymatically modified wheat (Triticum aestivum L.) endogenous lipids in bread making: a focus on gas cell stabilization mechanisms.

    Science.gov (United States)

    Gerits, Lien R; Pareyt, Bram; Masure, Hanne G; Delcour, Jan A

    2015-04-01

    Lipopan F and Lecitase Ultra lipases were used in straight dough bread making to study how wheat lipids affect bread loaf volume (LV) and crumb structure setting. Lipase effects on LV were dose and dough piece weight dependent. The bread quality improving mechanisms exerted by endogenous lipids were studied in terms of gluten network strengthening, which indirectly stabilizes gas cells, and in terms of direct interfacial gas cell stabilization. Unlike diacetyl tartaric esters of mono- and diacylglycerols (DATEM, used as control), lipase use did not impact dough extensibility. The effect on dough extensibility was therefore related to its lipid composition at the start of mixing. Both lipases and DATEM strongly increase the levels of polar lipids in dough liquor and their availability for and potential accumulation at gas cell interfaces. Lipases form lysolipids that emulsify other lipids. We speculate that DATEM competes with (endogenous) polar lipids for interacting with gluten proteins.

  19. 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

  20. Predicted versus measured thoracic gas volumes of collegiate athletes made by the BOD POD air displacement plethysmography system.

    Science.gov (United States)

    Wagner, Dale R

    2015-10-01

    Measured (TGVm) and predicted (TGVp) thoracic gas volumes from the BOD POD were compared in 33 lean, university athletes. On average, TGVp (3.529 L) was not significantly different (p = 0.343) from TGVm (3.628 L); however, there was a bias (r = -0.703, p < 0.001). The difference in the percentage of body fat (BF) was within ±2% BF for 76% of the sample, but athletes at the extremes of height should have TGV measured.

  1. Geochemical constraints on the origin and volume of gas in the New Albany Shale (Devonian-Mississippian), eastern Illinois Basin

    Science.gov (United States)

    Strapoc, D.; Mastalerz, Maria; Schimmelmann, A.; Drobniak, A.; Hasenmueller, N.R.

    2010-01-01

    This study involved analyses of kerogen petrography, gas desorption, geochemistry, microporosity, and mesoporosity of the New Albany Shale (Devonian-Mississippian) in the eastern part of the Illinois Basin. Specifically, detailed core analysis from two locations, one in Owen County, Indiana, and one in Pike County, Indiana, has been conducted. The gas content in the locations studied was primarily dependent on total organic carbon content and the micropore volume of the shales. Gas origin was assessed using stable isotope geochemistry. Measured and modeled vitrinite reflectance values were compared. Depth of burial and formation water salinity dictated different dominant origins of the gas in place in the two locations studied in detail. The shallower Owen County location (415-433 m [1362-1421 ft] deep) contained significant additions of microbial methane, whereas the Pike County location (832-860 m [2730-2822 ft] deep) was characterized exclusively by thermogenic gas. Despite differences in the gas origin, the total gas in both locations was similar, reaching up to 2.1 cm3/g (66 scf/ton). Lower thermogenic gas content in the shallower location (lower maturity and higher loss of gas related to uplift and leakage via relaxed fractures) was compensated for by the additional generation of microbial methane, which was stimulated by an influx of glacial melt water, inducing brine dilution and microbial inoculation. The characteristics of the shale of the Maquoketa Group (Ordovician) in the Pike County location are briefly discussed to provide a comparison to the New Albany Shale. Copyright ??2010. The American Association of Petroleum Geologists. All rights reserved.

  2. Membrane mechanisms and intracellular signalling in cell volume regulation

    DEFF Research Database (Denmark)

    Hoffmann, Else Kay; Dunham, Philip B.

    1995-01-01

    Volume regulation, Signal transduction, Calcium-calmodulin, Stretch-activated channels, Eicosanoids, Macromolecular crowding, Cytoskeleton, Protein phosphorylation, dephosphorylation.......Volume regulation, Signal transduction, Calcium-calmodulin, Stretch-activated channels, Eicosanoids, Macromolecular crowding, Cytoskeleton, Protein phosphorylation, dephosphorylation....

  3. A compact resonant \\Pi-shaped photoacoustic cell with low window background for gas sensing

    CERN Document Server

    Ulasevich, A L; Kouzmouk, A A; Starovoitov, V S

    2013-01-01

    A resonant photoacoustic cell capable of detecting the traces of gases at an amplitude-modulation regime is represented. The cell is designed so as to minimize the window background for the cell operation at a selected acoustic resonance. A compact prototype cell (the volume of acoustic cavity of ~ 0.2 cm^3, total cell weight of 3.5 g) adapted to the narrow diffraction-limited beam of near-infrared laser is produced and examined experimentally. The noise-associated measurement error and laser-initiated signals are studied as functions of modulation frequency. The background signal and useful response to light absorption by the gas are analyzed in measurements of absorption for ammonia traces in nitrogen flow with the help of a pigtailed DFB laser diode operated near a wavelength of 1.53 um. The performance of absorption detection and gas-leak sensing for the prototype operated at the second longitudinal acoustic resonance (the resonance frequency of ~ 4.38 kHz, Q-factor of ~ 13.9) is estimated. The noise-equi...

  4. Gasotransmitters are emerging as new guard cell signaling molecules and regulators of leaf gas exchange.

    Science.gov (United States)

    García-Mata, Carlos; Lamattina, Lorenzo

    2013-03-01

    Specialized guard cells modulate plant gas exchange through the regulation of stomatal aperture. The size of the stomatal pore is a direct function of the volume of the guard cells. The transport of solutes across channels in plasma membrane is a crucial process in the maintenance of guard cell water status. The fine tuned regulation of that transport requires an integrated convergence of multiple endogenous and exogenous signals perceived at both the cellular and the whole plant level. Gasotransmitters are novel signaling molecules with key functions in guard cell physiology. Three gasotransmitters, nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (H(2)S) are involved in guard cell regulatory processes. These molecules are endogenously produced by plant cells and are part of the guard cells responses to drought stress conditions through ABA-dependent pathways. In this review, we summarize the current knowledge of gasotransmitters as versatile molecules interacting with different components of guard cell signaling network and propose them as players in new paradigms to study ABA-independent guard cell responses to water deficit.

  5. Correlation between Cohesive Energy Density, Fractional Free Volume, and Gas Transport Properties of Poly(ethylene-co-vinyl acetate Materials

    Directory of Open Access Journals (Sweden)

    Piotr Kubica

    2015-01-01

    Full Text Available The transport properties of the poly(ethylene-co-vinyl acetate (EVA materials to He, N2, O2, and CO2 are correlated with two polymer molecular structure parameters, that is, cohesive energy density (CED and fractional free volume (FFV, determined by the group contribution method. In our preceding paper, the attempt was made to approximate EVA permeability using a linear function of 1/FFV as predicted by the free volume theory. However, the deviations from this relationship appeared to be significant. In this paper, it is shown that permeation of gas molecules is controlled not only by free volume but also by the polymer cohesive energy. Moreover, the behavior of CO2 was found to differ significantly from that of other gases. In this instance, the correlation is much better when diffusivity instead of permeability is taken into account in a modified transport model.

  6. Intracellular ion concentrations and cell volume during cholinergic stimulation of eccrine secretory coil cells

    Energy Technology Data Exchange (ETDEWEB)

    Takemura, T.; Sato, F.; Saga, K.; Suzuki, Y.; Sato, K. (Univ. of Iowa College of Medicine, Iowa City (USA))

    1991-02-01

    Methacholine (MCh)-induced changes in intracellular concentrations of Na, K, and Cl (( Na)i, (K)i, and (Cl)i, respectively) and in cellular dry mass (a measure of cell shrinkage) were examined in isolated monkey eccrine sweat secretory coils by electron probe X-ray microanalysis using the peripheral standard method. To further confirm the occurrence of cell shrinkage during MCh stimulation, the change in cell volume of dissociated clear and dark cells were directly determined under a light microscope equipped with differential interference contrast (DIC) optics. X-ray microanalysis revealed a biphasic increase in cellular dry mass in clear cells during continuous MCh stimulation; an initial increase of dry mass to 158% (of control) followed by a plateau at 140%, which correspond to the decrease in cell volume of 37 and 29%, respectively. The latter agrees with the MCh-induced cell shrinkage of 29% in dissociated clear cells. The MCh-induced increase in dry mass in myoepithelial cells was less than half that of clear cells. During the steady state of MCh stimulation, both (K+)i and (Cl)i of clear cells decreased by about 45%, whereas (Na)i increased in such a way to maintain the sum of (Na) i + (K)i constant. There was a small (12-15 mM) increase in (Na)i and a decrease in (K)i in myoepithelial cells during stimulation with MCh. Dissociated dark cells failed to significantly shrink during MCh stimulation. The decrease in (Cl)i in the face of constant (Na)i + (K)i suggests the accumulation of unknown anion(s) inside the clear cell during MCh stimulation.

  7. Evidence for P-Glycoprotein Involvement in Cell Volume Regulation Using Coulter Sizing in Flow Cytometry.

    Science.gov (United States)

    Pasquier, Jennifer; Rioult, Damien; Abu-Kaoud, Nadine; Hoarau-Véchot, Jessica; Marin, Matthieu; Le Foll, Frank

    2015-06-24

    The regulation of cell volume is an essential function that is coupled to a variety of physiological processes such as receptor recycling, excitability and contraction, cell proliferation, migration, and programmed cell death. Under stress, cells undergo emergency swelling and respond to such a phenomenon with a regulatory volume decrease (RVD) where they release cellular ions, and other osmolytes as well as a concomitant loss of water. The link between P-glycoprotein, a transmembrane transporter, and cell volume regulation is controversial, and changes in cells volume are measured using microscopy or electrophysiology. For instance, by using the patch-clamp method, our team demonstrated that chloride currents activated in the RVD were more intense and rapid in a breast cancer cell line overexpressing the P-glycoprotein (P-gp). The Cell Lab Quanta SC is a flow cytometry system that simultaneously measures electronic volume, side scatter and three fluorescent colors; altogether this provides unsurpassed population resolution and accurate cell counting. Therefore, here we propose a novel method to follow cellular volume. By using the Coulter-type channel of the cytometer Cell Lab Quanta SC MPL (multi-platform loading), we demonstrated a role for the P-gp during different osmotic treatments, but also a differential activity of the P-gp through the cell cycle. Altogether, our data strongly suggests a role of P-gp in cell volume regulation.

  8. Evidence for P-Glycoprotein Involvement in Cell Volume Regulation Using Coulter Sizing in Flow Cytometry

    Directory of Open Access Journals (Sweden)

    Jennifer Pasquier

    2015-06-01

    Full Text Available The regulation of cell volume is an essential function that is coupled to a variety of physiological processes such as receptor recycling, excitability and contraction, cell proliferation, migration, and programmed cell death. Under stress, cells undergo emergency swelling and respond to such a phenomenon with a regulatory volume decrease (RVD where they release cellular ions, and other osmolytes as well as a concomitant loss of water. The link between P-glycoprotein, a transmembrane transporter, and cell volume regulation is controversial, and changes in cells volume are measured using microscopy or electrophysiology. For instance, by using the patch-clamp method, our team demonstrated that chloride currents activated in the RVD were more intense and rapid in a breast cancer cell line overexpressing the P-glycoprotein (P-gp. The Cell Lab Quanta SC is a flow cytometry system that simultaneously measures electronic volume, side scatter and three fluorescent colors; altogether this provides unsurpassed population resolution and accurate cell counting. Therefore, here we propose a novel method to follow cellular volume. By using the Coulter-type channel of the cytometer Cell Lab Quanta SC MPL (multi-platform loading, we demonstrated a role for the P-gp during different osmotic treatments, but also a differential activity of the P-gp through the cell cycle. Altogether, our data strongly suggests a role of P-gp in cell volume regulation.

  9. Fifth DOE symposium on enhanced oil and gas recovery and improved drilling technology. Volume 2. Oil

    Energy Technology Data Exchange (ETDEWEB)

    Linville, B. [ed.

    1979-01-01

    Volume 2 contains papers from the following sessions: residual oil determination; thermal methods; heavy oil-tar sands; technology transfer; and carbon dioxide flooding. Individual papers were processed.

  10. Parameterization retrieval of trace gas volume mixing ratios from Airborne MAX-DOAS

    Science.gov (United States)

    Dix, Barbara; Koenig, Theodore K.; Volkamer, Rainer

    2016-11-01

    We present a parameterization retrieval of volume mixing ratios (VMRs) from differential slant column density (dSCD) measurements by Airborne Multi-AXis Differential Optical Absorption Spectroscopy (AMAX-DOAS). The method makes use of the fact that horizontally recorded limb spectra (elevation angle 0°) are strongly sensitive to the atmospheric layer at instrument altitude. These limb spectra are analyzed using reference spectra that largely cancel out column contributions from above and below the instrument, so that the resulting limb dSCDs, i.e., the column integrated concentration with respect to a reference spectrum, are almost exclusively sensitive to the atmospheric layers around instrument altitude. The conversion of limb dSCDs into VMRs is then realized by calculating box air mass factors (Box-AMFs) for a Rayleigh atmosphere and applying a scaling factor constrained by O4 dSCDs to account for aerosol extinction. An iterative VMR retrieval scheme corrects for trace gas profile shape effects. Benefits of this method are (1) a fast conversion that only requires the computation of Box-AMFs in a Rayleigh atmosphere; (2) neither local aerosol extinction nor the slant column density in the DOAS reference (SCDref) needs to be known; and (3) VMRs can be retrieved for every measurement point along a flight track, thus increasing statistics and adding flexibility to capture concentration gradients. Sensitivity studies are performed for bromine monoxide (BrO), iodine monoxide (IO) and nitrogen dioxide (NO2), using (1) simulated dSCD data for different trace gas and aerosol profiles and (2) field measurements from the Tropical Ocean tRoposphere Exchange of Reactive halogen species and Oxygenated VOC (TORERO) field experiment. For simulated data in a Rayleigh atmosphere, the agreement between the VMR from the parameterization method (VMRpara) and the true VMR (VMRtrue) is excellent for all trace gases. Offsets, slopes and R2 values for the linear fit of VMRpara over

  11. Intracellular Ca2+ responses and cell volume regulation upon cholinergic and purinergic stimulation in an immortalized salivary cell line.

    Science.gov (United States)

    Aure, Marit H; Røed, Asbjørn; Galtung, Hilde Kanli

    2010-06-01

    The water channel aquaporin 5 (AQP5) seems to play a key role in salivary fluid secretion and appears to be critical in the cell volume regulation of acinar cells. Recently, the cation channel transient potential vanilloid receptor 4 (TRPV4) was shown to be functionally connected to AQP5 and also to cell volume regulation in salivary glands. We used the Simian virus 40 (SV40) immortalized cell line SMG C10 from the rat submandibular salivary gland to investigate the effect of ATP and the neurotransmitter analogue carbachol on Ca(2+) signalling and cell volume regulation, as well as the involvement of TRPV4 in the responses. We used fura-2-AM imaging, cell volume measurements, and western blotting. Both carbachol and ATP increased the concentration of intracellular Ca(2+), but no volume changes could be measured. Inhibition of TRPV4 with ruthenium red impaired both ATP- and carbachol-stimulated Ca(2+) signals. Peak Ca(2+) signalling during hyposmotic exposure was significantly decreased following inhibition of TRPV4, while the cells' ability to volume regulate appeared to be unaffected. These results show that in the SMG C10 cells, simulation of nervous stimulation did not induce cell swelling, although the cells had intact volume regulatory mechanisms. Furthermore, even though Ca(2+) signals were not needed for this volume regulation, TRPV4 seems to play a role during ATP and carbachol stimulation.

  12. Gas/Water and Heat Management of PEM-Based Fuel Cell and Electrolyzer Systems for Space Applications

    Science.gov (United States)

    Guo, Qing; Ye, Fang; Guo, Hang; Ma, Chong Fang

    2016-11-01

    Hydrogen/oxygen fuel cells were successfully utilized in the field of space applications to provide electric energy and potable water in human-rated space mission since the 1960s. Proton exchange membrane (PEM) based fuel cells, which provide high power/energy densities, were reconsidered as a promising space power equipment for future space exploration. PEM-based water electrolyzers were employed to provide life support for crews or as major components of regenerative fuel cells for energy storage. Gas/water and heat are some of the key challenges in PEM-based fuel cells and electrolytic cells, especially when applied to space scenarios. In the past decades, efforts related to gas/water and thermal control have been reported to effectively improve cell performance, stability lifespan, and reduce mass, volume and costs of those space cell systems. This study aimed to present a primary review of research on gas/water and waste thermal management for PEM-based electrochemical cell systems applied to future space explorations. In the fuel cell system, technologies related to reactant supplement, gas humidification, water removal and active/passive water separation were summarized in detail. Experimental studies were discussed to provide a direct understanding of the effect of the gas-liquid two-phase flow on product removal and mass transfer for PEM-based fuel cell operating in a short-term microgravity environment. In the electrolyzer system, several active and static passive phaseseparation methods based on diverse water supplement approaches were discussed. A summary of two advanced passive thermal management approaches, which are available for various sizes of space cell stacks, was specifically provided

  13. Gas/Water and Heat Management of PEM-Based Fuel Cell and Electrolyzer Systems for Space Applications

    Science.gov (United States)

    Guo, Qing; Ye, Fang; Guo, Hang; Ma, Chong Fang

    2017-02-01

    Hydrogen/oxygen fuel cells were successfully utilized in the field of space applications to provide electric energy and potable water in human-rated space mission since the 1960s. Proton exchange membrane (PEM) based fuel cells, which provide high power/energy densities, were reconsidered as a promising space power equipment for future space exploration. PEM-based water electrolyzers were employed to provide life support for crews or as major components of regenerative fuel cells for energy storage. Gas/water and heat are some of the key challenges in PEM-based fuel cells and electrolytic cells, especially when applied to space scenarios. In the past decades, efforts related to gas/water and thermal control have been reported to effectively improve cell performance, stability lifespan, and reduce mass, volume and costs of those space cell systems. This study aimed to present a primary review of research on gas/water and waste thermal management for PEM-based electrochemical cell systems applied to future space explorations. In the fuel cell system, technologies related to reactant supplement, gas humidification, water removal and active/passive water separation were summarized in detail. Experimental studies were discussed to provide a direct understanding of the effect of the gas-liquid two-phase flow on product removal and mass transfer for PEM-based fuel cell operating in a short-term microgravity environment. In the electrolyzer system, several active and static passive phaseseparation methods based on diverse water supplement approaches were discussed. A summary of two advanced passive thermal management approaches, which are available for various sizes of space cell stacks, was specifically provided

  14. Model documentation: Natural gas transmission and distribution model of the National Energy Modeling System. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-02-17

    The Natural Gas Transmission and Distribution Model (NGTDM) is the component of the National Energy Modeling System (NEMS) that is used to represent the domestic natural gas transmission and distribution system. NEMS was developed in the Office of integrated Analysis and Forecasting of the Energy information Administration (EIA). NEMS is the third in a series of computer-based, midterm energy modeling systems used since 1974 by the EIA and its predecessor, the Federal Energy Administration, to analyze domestic energy-economy markets and develop projections. The NGTDM is the model within the NEMS that represents the transmission, distribution, and pricing of natural gas. The model also includes representations of the end-use demand for natural gas, the production of domestic natural gas, and the availability of natural gas traded on the international market based on information received from other NEMS models. The NGTDM determines the flow of natural gas in an aggregate, domestic pipeline network, connecting domestic and foreign supply regions with 12 demand regions. The methodology employed allows the analysis of impacts of regional capacity constraints in the interstate natural gas pipeline network and the identification of pipeline capacity expansion requirements. There is an explicit representation of core and noncore markets for natural gas transmission and distribution services, and the key components of pipeline tariffs are represented in a pricing algorithm. Natural gas pricing and flow patterns are derived by obtaining a market equilibrium across the three main elements of the natural gas market: the supply element, the demand element, and the transmission and distribution network that links them. The NGTDM consists of four modules: the Annual Flow Module, the Capacity F-expansion Module, the Pipeline Tariff Module, and the Distributor Tariff Module. A model abstract is provided in Appendix A.

  15. Energy Conversion Alternatives Study (ECAS), General Electric Phase 1. Volume 2: Advanced energy conversion systems. Part 1: Open-cycle gas turbines

    Science.gov (United States)

    Brown, D. H.; Corman, J. C.

    1976-01-01

    Ten energy conversion systems are defined and analyzed in terms of efficiency. These include: open-cycle gas turbine recuperative; open-cycle gas turbine; closed-cycle gas turbine; supercritical CO2 cycle; advanced steam cycle; liquid metal topping cycle; open-cycle MHD; closed-cycle inert gas MHD; closed-cycle liquid metal MHD; and fuel cells. Results are presented.

  16. Morphometry and cell volumes of diatoms from a tropical estuary of India

    Digital Repository Service at National Institute of Oceanography (India)

    RaviKumar, M.S.; Ramaiah, N.; Tang, D.

    Cell volumes and per cell carbon contents of different diatoms (10 centric, 14 pennate and 1 dinoflagellate) collected from Dona Paula Bay in the central west coast of India have been analyzed. Morphometric information on the phytoplankton types...

  17. Optical volume and mass measurements show that mammalian cells swell during mitosis.

    Science.gov (United States)

    Zlotek-Zlotkiewicz, Ewa; Monnier, Sylvain; Cappello, Giovanni; Le Berre, Mael; Piel, Matthieu

    2015-11-23

    The extent, mechanism, and function of cell volume changes during specific cellular events, such as cell migration and cell division, have been poorly studied, mostly because of a lack of adequate techniques. Here we unambiguously report that a large range of mammalian cell types display a significant increase in volume during mitosis (up to 30%). We further show that this increase in volume is tightly linked to the mitotic state of the cell and not to its spread or rounded shape and is independent of the presence of an intact actomyosin cortex. Importantly, this volume increase is not accompanied by an increase in dry mass and thus corresponds to a decrease in cell density. This mitotic swelling might have important consequences for mitotic progression: it might contribute to produce strong pushing forces, allowing mitotic cells to round up; it might also, by lowering cytoplasmic density, contribute to the large change of physicochemical properties observed in mitotic cells.

  18. Analytical Chemistry Laboratory (ACL) procedure compendium. Volume 7, Safety operation procedure for hot cell

    Energy Technology Data Exchange (ETDEWEB)

    1993-08-01

    This volume contains the interim change notice for the safety operation procedure for hot cell. It covers the master-slave manipulators, dry waste removal, cell transfers, hoists, cask handling, liquid waste system, and physical characterization of fluids.

  19. Sampling small volumes of ambient ammonia using a miniaturized gas sampler

    NARCIS (Netherlands)

    Timmer, B.H.; Olthuis, Wouter; van den Berg, Albert

    2004-01-01

    The development of a gas sampler for a miniaturized ambient ammonia detector is described. A micromachined channel system is realized in glass and silicon using powder blasting and anodic bonding. The analyte gas is directly mixed with purified water, dissolving the ammonia that will dissociate into

  20. Proceedings of the natural gas RD&D contractors review meeting, Volume I

    Energy Technology Data Exchange (ETDEWEB)

    Malone, R.D.

    1995-04-01

    This report contains papers which were presented at the natural gas contractors review meeting held on April 4-6, 1995. Topics were concerned with resource and reserves, low permeability reservoir characterization, natural fracture detection, drilling, completion, and stimulation, and natural gas upgrading. Individual papers were processed separately for the United States Department of Energy databases.

  1. PRESSURIZED SOLID OXIDE FUEL CELL/GAS TURBINE POWER SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    W.L. Lundberg; G.A. Israelson; R.R. Moritz(Rolls-Royce Allison); S.E. Veyo; R.A. Holmes; P.R. Zafred; J.E. King; R.E. Kothmann (Consultant)

    2000-02-01

    Power systems based on the simplest direct integration of a pressurized solid oxide fuel cell (SOFC) generator and a gas turbine (GT) are capable of converting natural gas fuel energy to electric power with efficiencies of approximately 60% (net AC/LHV), and more complex SOFC and gas turbine arrangements can be devised for achieving even higher efficiencies. The results of a project are discussed that focused on the development of a conceptual design for a pressurized SOFC/GT power system that was intended to generate 20 MWe with at least 70% efficiency. The power system operates baseloaded in a distributed-generation application. To achieve high efficiency, the system integrates an intercooled, recuperated, reheated gas turbine with two SOFC generator stages--one operating at high pressure, and generating power, as well as providing all heat needed by the high-pressure turbine, while the second SOFC generator operates at a lower pressure, generates power, and provides all heat for the low-pressure reheat turbine. The system cycle is described, major system components are sized, the system installed-cost is estimated, and the physical arrangement of system components is discussed. Estimates of system power output, efficiency, and emissions at the design point are also presented, and the system cost of electricity estimate is developed.

  2. Air Contamination Quantification by FTIR with Gas Cell

    Science.gov (United States)

    Freischlag, Jason

    2017-01-01

    Air quality is of utmost importance in environmental studies and has many industrial applications such as aviators grade breathing oxygen (ABO) for pilots and breathing air for fire fighters. Contamination is a major concern for these industries as identified in MIL-PRF-27210, CGA G-4.3, CGA G-7.1, and NFPA 1989. Fourier Transform Infrared Spectroscopy (FTIR) is a powerful tool that when combined with a gas cell has tremendous potential for gas contamination analysis. Current procedures focus mostly on GC-MS for contamination quantification. Introduction of this topic will be done through a comparison of the currently used deterministic methods for gas contamination with those of FTIR gas analysis. Certification of the mentioned standards through the ISOIEC 17065 certifying body A2LA will be addressed followed by an evaluation of quality information such as the determinations of linearity and the limits of detection and quantitation. Major interferences and issues arising from the use of the FTIR for accredited work with ABO and breathing air will be covered.

  3. Modulation of KCNQ4 channel activity by changes in cell volume

    DEFF Research Database (Denmark)

    Hougaard, Charlotte; Klaerke, Dan A; Hoffmann, Else K;

    2004-01-01

    KCNQ4 channels expressed in HEK 293 cells are sensitive to cell volume changes, being activated by swelling and inhibited by shrinkage, respectively. The KCNQ4 channels contribute significantly to the regulatory volume decrease (RVD) process following cell swelling. Under isoosmotic conditions......, the KCNQ4 channel activity is modulated by protein kinases A and C, G protein activation, and a reduction in the intracellular Ca2+ concentration, but these signalling pathways are not responsible for the increased channel activity during cell swelling....

  4. Natural Gas Transmission and Distribution Model of the National Energy Modeling System. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-01-01

    The Natural Gas Transmission and Distribution Model (NGTDM) is the component of the National Energy Modeling System (NEMS) that is used to represent the domestic natural gas transmission and distribution system. The NGTDM is the model within the NEMS that represents the transmission, distribution, and pricing of natural gas. The model also includes representations of the end-use demand for natural gas, the production of domestic natural gas, and the availability of natural gas traded on the international market based on information received from other NEMS models. The NGTDM determines the flow of natural gas in an aggregate, domestic pipeline network, connecting domestic and foreign supply regions with 12 demand regions. The purpose of this report is to provide a reference document for model analysts, users, and the public that defines the objectives of the model, describes its basic design, provides detail on the methodology employed, and describes the model inputs, outputs, and key assumptions. Subsequent chapters of this report provide: an overview of NGTDM; a description of the interface between the NEMS and NGTDM; an overview of the solution methodology of the NGTDM; the solution methodology for the Annual Flow Module; the solution methodology for the Distributor Tariff Module; the solution methodology for the Capacity Expansion Module; the solution methodology for the Pipeline Tariff Module; and a description of model assumptions, inputs, and outputs.

  5. Synthesis gas regeneration electrotechnology using volume high-voltage pulsed discharges: corona and barrier ones

    Directory of Open Access Journals (Sweden)

    M.I. Boyko

    2014-09-01

    Full Text Available Factory testing of a created high-voltage complex (plant has been conducted. The complex consists of two pulse generators with the repetition rate of up to 50,000 pulses per second and load reactors with pulsed discharges - corona and barrier ones. Transistor (IGBT keys are used as energy switches. The efficient mode of coke gas methane conversion (steam reforming to syngas has been obtained with application of the complex created. A unidirectional action of the pulsed discharges, the gas mixture temperature, and a nickel catalyst has reduced the specific energy consumption for synthesis gas regeneration during the conversion. A feasible mechanism of this conversion is described.

  6. Development of Electrolysis System Powered by Solar-Cell Array to Supply Hydrogen Gas for Fuel-Cell Energy Resource Systems

    Science.gov (United States)

    Priambodo, Purnomo Sidi; Yusivar, Feri; Subiantoro, Aries; Gunawan, Ridwan

    2009-09-01

    The huge demand of energy worldwide and the depletion of fossil based energy, is a strong reason to rapidly develop any kind of renewable energy resources, which has economical advantages and zero pollution effect. One of the renewable energy technologies aimed in this paper is the generation of electric-energy based on fuel-cell technology, where the input hydrogen (H2) gas is supplied by electrolysis system powered by renewable energy system based on solar cell. In this paper, the authors explain the development of electrolysis system which is powered by solar cell array to supply hydrogen for fuel-cell system. The authors explain in detail how to design an efficient electrolysis system to obtain high ratio conversion of electric energy to hydrogen gas volume. It includes the explanation of the usage of multiple anodes with a single cathode for many solar cell inputs in a single electrolysis system. Hereinafter this is referred as multiple anode electrolysis system. This multiple anode electrolysis system makes the management of hydrogen gas becomes more efficient and effective by using only a single hydrogen gas storage system. This paper also explain the careful design of the resistance value of the electrolysis system to protect or avoid the solar cell panel to deliver excessive current to the electrolysis system which can cause damage on the solar cell panel. Moreover, the electrolyte volume detector is applied on the system as a tool to measure the electrolyte concentration to assure the system resistance is still in the allowed range. Further, the hydrogen gas produced by electrolysis system is stored into the gas storage which consists of silica-gel purifier, first stage low pressure gas bottle, vacuum pump, and second stage high pressure gas bottle. In the first step, the pump will vacuum the first bottle. The first bottle will collect the hydrogen from the electrolysis system through the silica gel to get rid of water vapor. When the first bottle

  7. Evaluated kinetic and photochemical data for atmospheric chemistry: Volume III ? gas phase reactions of inorganic halogens

    OpenAIRE

    Atkinson, R.; Baulch, D. L.; Cox, R A; J. N. Crowley; Hampson, R. F.; Hynes, R. G.; Jenkin, M. E.; M. J. Rossi; Troe, J.

    2007-01-01

    International audience; This article, the third in the series, presents kinetic and photochemical data evaluated by the IUPAC Subcommittee on Gas Kinetic Data Evaluation for Atmospheric Chemistry. It covers the gas phase and photochemical reactions of inorganic halogen species, which were last published in J. Phys. Chem. Ref. Data, in 2000 (Atkinson et al., 2000), were updated on the IUPAC website in 2003 and are updated again in the present evaluation. The article consists of a summary sheet...

  8. SEASAT economic assessment. Volume 3: Offshore oil and natural gas industry case study and generalization

    Science.gov (United States)

    1975-01-01

    The economic benefits of improved ocean condition, weather and ice forecasts by SEASAT satellites to the exploration, development and production of oil and natural gas in the offshore regions are considered. The results of case studies which investigate the effects of forecast accuracy on offshore operations in the North Sea, the Celtic Sea, and the Gulf of Mexico are reported. A methodology for generalizing the results to other geographic regions of offshore oil and natural gas exploration and development is described.

  9. Numerical Simulation of Particle Mixing in Dispersed Gas-Liquid-Solid Flows using a Combined Volume of Fluid and Discrete Particle Approach

    NARCIS (Netherlands)

    Deen, Niels G.; Sint Annaland, van Martin; Kuipers, J.A.M.

    2007-01-01

    In this paper a hybrid model is presented for the numerical simulation of gas-liquid-solid flows using a combined Volume Of Fluid (VOF) and Discrete Particle (DP) approach applied for respectively dispersed gas bubbles and solid particles present in the continuous liquid phase. The hard sphere DP mo

  10. Direct numerical simulation of particle mixing in dispersed gas-liquid-solid flows using a combined volume of fluid and discrete particle approach

    NARCIS (Netherlands)

    Deen, Niels G.; Sint Annaland, van Martin; Kuipers, J.A.M.

    2006-01-01

    In this paper a hybrid model is presented for the numerical simulation of gas-liquid-solid flows using a combined Volume Of Fluid (VOF) and Discrete Particle (DP) approach applied for respectively dispersed gas bubbles and solid particles present in the continuous liquid phase. The hard sphere DP mo

  11. Summary and assessment of METC zinc ferrite hot coal gas desulfurization test program, final report: Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Underkoffler, V.S.

    1986-12-01

    The Morgantown Energy Technology Center (METC) has conducted a test program to develop a zinc ferrite-based high temperature desulfurization process which could be applied to fuel gas entering downstream components such as molten carbonate fuel cells or gas turbines. As a result of prior METC work with iron oxide and zinc oxide sorbents, zinc ferrite evolved as a candidate with the potential for high capacity, low equilibrium levels of H/sub 2/S, and structural stability after multiple regenerations. The program consisted of laboratory-scale testing with a two-inch diameter reactor and simulated fixed-bed gasifier gas; bench-scale testing with a six-inch diameter reactor and actual gas from the METC 42-inch fixed bed gasifier; as well as laboratory-scale testing of zinc ferrite with simulated fluidized bed gasifier gas. Optimum operating parameters for zinc ferrite such as temperatures, gas compositions, and space velocities are discussed. From the test results, salient features of zinc ferrite were derived and discussed in regard to system implications, issues raised, and technical requirements. 47 refs., 53 figs., 41 tabs.

  12. Effect of radiologic contrast media on cell volume regulatory mechanisms in human red blood cells.

    Science.gov (United States)

    Galtung, Hilde Kanli; Sørlundsengen, Vibeke; Sakariassen, Kjell S; Benestad, Haakon B

    2002-08-01

    The authors performed this study to evaluate cell volume regulation in human red blood cells (RBCs) after incubation in solutions of three contrast media: iohexol (830 mOsm), ioxaglate (520 mOsm), and iodixanol (300 mOsm). Whole blood sampled from six healthy subjects was exposed to Ringer solutions containing 25% or 5% vol/vol iohexol (final osmolality, 440 or 340 mOsm, respectively), ioxaglate (final osmolality, 395 or 335 mOsm, respectively), iodixanol (final osmolality, 330 or 315 mOsm, respectively), or NaCl (control solutions with the same osmolality as that of the contrast media). In some experiments, control RBCs were subjected to a hyposmotic solution (100 mOsm). RBC volumes were obtained with a Coulter counter. The RBCs showed normal regulatory cell shrinkage after hyposmotically induced swelling. All 25% vol/vol contrast material solutions and their control solutions induced RBC shrinkage (range, 6% +/- 1 [standard error] to 22% +/- 3). The same was true for cells exposed to 5% vol/vol contrast material (range, 4% +/- 1 to 7% +/- 1). The shrinkage phase was followed by cell swelling (10% +/- 2 to 20% +/- 2 for 25% contrast material and their control solutions and 8% +/- 1 to 15% +/- 2 for 5% contrast material and their control solutions). No contrast material-exposed RBCs increased their volumes to the level reached with their control solutions. RBCs exposed to hyperosmotic iohexol, ioxaglate, or iodixanol solutions shrank and then swelled. The degree of shrinkage and subsequent swelling could not be explained simply with the osmolality of the test solutions. Physicochemical properties of the contrast media must be involved, putatively affecting electrolyte fluxes over the RBC membrane. Possible targets of these effects are the K+/Cl- symporter, K+ channels, and the Na+/K+/Cl- symporter.

  13. Development of gas absorption cells for infrared echelle spectrographs

    Directory of Open Access Journals (Sweden)

    Martín E.L.

    2011-07-01

    Full Text Available High-resolution spectroscopy in the near-infrared could become the leading method for discovering extra-solar planets around very low-mass stars and brown dwarfs. To help to achieve an accuracy of about 1 m/s, we are developing a gas cell which consists of a mixture of gases whose absorption spectral lines span all over the near-infrared region. We here present a summary of the working technique and the main results obtained so far.

  14. 2,3-Dihydroxybenzoic acid attenuates kanamycin-induced volume reduction in mouse utricular type I hair cells

    DEFF Research Database (Denmark)

    Severinsen, Stig Åvall; Kirkegaard, Mette; Nyengaard, Jens Randel

    2006-01-01

    injection. Total volume of the utricle, as well as total number of hair and supporting cells, were estimated on light microscopic sections. Total volume and mean volume of hair cell types I and II and supporting cells were estimated on digital transmission electron micrographs. Total volume of the utricular...... macula, hair cell type I and supporting cells decreased significantly in animals injected with kanamycin but not in animals co-treated with DHB. Hair and supporting cell numbers remained unchanged in all three groups. In conclusion, the kanamycin-induced volume reduction of type I hair cells...

  15. Enhancing the Use of Coals by Gas Reburning - Sorbent Injection Volume 5 - Guideline Manual

    Energy Technology Data Exchange (ETDEWEB)

    None

    1998-06-01

    The purpose of the Guideline Manual is to provide recommendations for the application of combined gas reburning-sorbent injection (GR-SI) technologies to pre-NSPS boilers. The manual includes design recommendations, performance predictions, economic projections and comparisons with competing technologies. The report also includes an assessment of boiler impacts. Two full-scale demonstrations of gas reburning-sorbent injection form the basis of the Guideline Manual. Under the U.S. Department of Energy's Clean Coal Technology Program (Round 1), a project was completed to demonstrate control of boiler emissions that comprise acid rain precursors, specifically oxides of nitrogen (NOX) and sulfur dioxide (S02). Other project sponsors were the Gas Research Institute and the Illinois State Department of Commerce and Community Affairs. The project involved d,emonstrating the combined use of Gas Reburning and Sorbent Injection (GR-SI) to assess the air emissions reduction potential of these technologies.. Three potential coal-fired utility boiler host sites were evaluated: Illinois Power's tangentially-fired 71 MWe (net) Hennepin Unit #1, City Water Light and Power's cyclone- fired 33 MWe (gross) Lakeside Unit #7, and Central Illinois Light Company's wall-fired 117 MWe (net) Edwards Unit #1. Commercial demonstrations were completed on the Hennepin and Lakeside Units. The Edwards Unit was removed from consideration for a site demonstration due to retrofit cost considerations. Gas Reburning (GR) controls air emissions of NOX. Natural gas is introduced into the furnace hot flue gas creating a reducing reburning zone to convert NOX to diatomic nitrogen (N,). Overfire air is injected into the furnace above the reburning zone to complete the combustion of the reducing (fuel) gases created in the reburning zone. Sorbent Injection (S1) consists of the injection of dry, calcium-based sorbents into furnace hot flue gas to achieve S02 capture. `At each site where

  16. Enhancing the Use of Coals by Gas Reburning - Sorbent Injection - Volume 5 - Guideline Manual

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    1998-09-01

    The purpose of the Guideline Manual is to provide recommendations for the application of combined gas reburning-sorbent injection (GR-SI) technologies to pre-NSPS boilers. The manual includes design recommendations, performance predictions, economic projections and comparisons with competing technologies. The report also includes an assessment of boiler impacts. Two full-scale demonstrations of gas reburning-sorbent injection form the basis of the Guideline Manual. Under the U.S. Department of Energy's Clean Coal Technology Program (Round 1), a project was completed to demonstrate control of boiler emissions that comprise acid rain precursors, specifically oxides of nitrogen (NOx) and sulfur dioxide (SO2). Other project sponsors were the Gas Research Institute and the Illinois State Department of Commerce and Community Affairs. The project involved demonstrating the combined use of Gas Reburning and Sorbent Injection (GR-SI) to assess the air emissions reduction potential of these technologies.. Three potential coal-fired utility boiler host sites were evaluated: Illinois Power's tangentially-fired 71 MWe (net) Hennepin Unit #1, City Water Light and Power's cyclone- fired 33 MWe (gross) Lakeside Unit #7, and Central Illinois Light Company's wall-fired 117 MWe (net) Edwards Unit #1. Commercial demonstrations were completed on the Hennepin and Lakeside Units. The Edwards Unit was removed from consideration for a site demonstration due to retrofit cost considerations. Gas Reburning (GR) controls air emissions of NOx. Natural gas is introduced into the furnace hot flue gas creating a reducing reburning zone to convert NOx to diatomic nitrogen (N2). Overfire air is injected into the furnace above the reburning zone to complete the combustion of the reducing (fuel) gases created in the reburning zone. Sorbent Injection (SI) consists of the injection of dry, calcium-based sorbents into furnace hot

  17. Enhancing the Use of Coals by Gas Reburning - Sorbent Injection Volume 5 - Guideline Manual

    Energy Technology Data Exchange (ETDEWEB)

    None

    1998-06-01

    The purpose of the Guideline Manual is to provide recommendations for the application of combined gas reburning-sorbent injection (GR-SI) technologies to pre-NSPS boilers. The manual includes design recommendations, performance predictions, economic projections and comparisons with competing technologies. The report also includes an assessment of boiler impacts. Two full-scale demonstrations of gas reburning-sorbent injection form the basis of the Guideline Manual. Under the U.S. Department of Energy's Clean Coal Technology Program (Round 1), a project was completed to demonstrate control of boiler emissions that comprise acid rain precursors, specifically oxides of nitrogen (NOX) and sulfur dioxide (S02). Other project sponsors were the Gas Research Institute and the Illinois State Department of Commerce and Community Affairs. The project involved d,emonstrating the combined use of Gas Reburning and Sorbent Injection (GR-SI) to assess the air emissions reduction potential of these technologies.. Three potential coal-fired utility boiler host sites were evaluated: Illinois Power's tangentially-fired 71 MWe (net) Hennepin Unit #1, City Water Light and Power's cyclone- fired 33 MWe (gross) Lakeside Unit #7, and Central Illinois Light Company's wall-fired 117 MWe (net) Edwards Unit #1. Commercial demonstrations were completed on the Hennepin and Lakeside Units. The Edwards Unit was removed from consideration for a site demonstration due to retrofit cost considerations. Gas Reburning (GR) controls air emissions of NOX. Natural gas is introduced into the furnace hot flue gas creating a reducing reburning zone to convert NOX to diatomic nitrogen (N,). Overfire air is injected into the furnace above the reburning zone to complete the combustion of the reducing (fuel) gases created in the reburning zone. Sorbent Injection (S1) consists of the injection of dry, calcium-based sorbents into furnace hot flue gas to achieve S02 capture. `At each site where

  18. Enhancing the Use of Coals by Gas Reburning - Sorbent Injection - Volume 5 - Guideline Manual

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    1998-09-01

    The purpose of the Guideline Manual is to provide recommendations for the application of combined gas reburning-sorbent injection (GR-SI) technologies to pre-NSPS boilers. The manual includes design recommendations, performance predictions, economic projections and comparisons with competing technologies. The report also includes an assessment of boiler impacts. Two full-scale demonstrations of gas reburning-sorbent injection form the basis of the Guideline Manual. Under the U.S. Department of Energy's Clean Coal Technology Program (Round 1), a project was completed to demonstrate control of boiler emissions that comprise acid rain precursors, specifically oxides of nitrogen (NOx) and sulfur dioxide (SO2). Other project sponsors were the Gas Research Institute and the Illinois State Department of Commerce and Community Affairs. The project involved demonstrating the combined use of Gas Reburning and Sorbent Injection (GR-SI) to assess the air emissions reduction potential of these technologies.. Three potential coal-fired utility boiler host sites were evaluated: Illinois Power's tangentially-fired 71 MWe (net) Hennepin Unit #1, City Water Light and Power's cyclone- fired 33 MWe (gross) Lakeside Unit #7, and Central Illinois Light Company's wall-fired 117 MWe (net) Edwards Unit #1. Commercial demonstrations were completed on the Hennepin and Lakeside Units. The Edwards Unit was removed from consideration for a site demonstration due to retrofit cost considerations. Gas Reburning (GR) controls air emissions of NOx. Natural gas is introduced into the furnace hot flue gas creating a reducing reburning zone to convert NOx to diatomic nitrogen (N2). Overfire air is injected into the furnace above the reburning zone to complete the combustion of the reducing (fuel) gases created in the reburning zone. Sorbent Injection (SI) consists of the injection of dry, calcium-based sorbents into furnace hot

  19. Optimal use of buffer volumes for the measurement of atmospheric gas concentration in multi-point systems

    Science.gov (United States)

    Cescatti, Alessandro; Marcolla, Barbara; Goded, Ignacio; Gruening, Carsten

    2016-09-01

    Accurate multi-point monitoring systems are required to derive atmospheric measurements of greenhouse gas concentrations both for the calculation of surface fluxes with inversion transport models and for the estimation of non-turbulent components of the mass balance equation (i.e. advection and storage fluxes) at eddy covariance sites. When a single analyser is used to monitor multiple sampling points, the deployment of buffer volumes (BVs) along sampling lines can reduce the uncertainty due to the discrete temporal sampling of the signal. In order to optimize the use of buffer volumes we explored various set-ups by simulating their effect on time series of high-frequency CO2 concentration collected at three Fluxnet sites. Besides, we proposed a novel scheme to calculate half-hourly weighted arithmetic means from discrete point samples, accounting for the probabilistic fraction of the signal generated in the averaging period. Results show that the use of BVs with the new averaging scheme reduces the mean absolute error (MAE) up to 80 % compared to a set-up without BVs and up to 60 % compared to the case with BVs and a standard, non-weighted averaging scheme. The MAE of CO2 concentration measurements was observed to depend on the variability of the concentration field and on the size of BVs, which therefore have to be carefully dimensioned. The optimal volume size depends on two main features of the instrumental set-up: the number of measurement points and the time needed to sample at one point (i.e. line purging plus sampling time). A linear and consistent relationship was observed at all sites between the sampling frequency, which summarizes the two features mentioned above, and the renewal frequency associated with the volume. Ultimately, this empirical relationship can be applied to estimate the optimal volume size according to the technical specifications of the sampling system.

  20. Mini and Micro LNG for Commercialization of Small Volumes of Associated Gas

    OpenAIRE

    Tractebel Engineering

    2015-01-01

    While the LNG industry has traditionally focused primarily on development of ever increasing plant capacities, the maturity of the technology has allowed development of technologies applicable for small volumes to be competitive and potentially economically attractive. The main challenge for small scale LNG applications is therefore not technical but economic. Mini/micro LNG facilities cur...

  1. A computationally efficient 3D finite-volume scheme for violent liquid–gas sloshing

    CSIR Research Space (South Africa)

    Oxtoby, Oliver F

    2015-10-01

    Full Text Available . The high resolution artificial compressive (HiRAC) volume-of-fluid method is used for accurate capturing of the free surface in violent flow regimes while allowing natural applicability to hybrid-unstructured meshes. The code is parallelised for solution...

  2. Capillary gas chromatographic analysis of nerve agents using large volume injections

    NARCIS (Netherlands)

    Degenhardt, C.E.A.M.; Kientz, C.E.

    1996-01-01

    The use of large volume injections has been studied for the verification of intact organophosphorus chemical warfare agents in water samples. As the use of ethyl acetate caused severe detection problems new potential solvents were evaluated. With the developed procedure, the nerve agents sarin, tabu

  3. Blood volume measurements in gopher snakes, using autologous 51Cr-labeled red blood cells.

    Science.gov (United States)

    Smeller, J M; Bush, M; Seal, U S

    1978-02-01

    Blood volume determinations were performed in 5 anesthetized gopher snakes (Pituophis melanoleucus catenifer) by means of a 51Cr-labeled red blood cell (RBC) method. The mean blood volume was 52.8 ml/kg of body weight (+/- 6.21 SE). Previous blood volume measurements have not been reported for this species. The RBC survival rate was estimated to be greater than 660 days. The RBC survival rate is long, but it cannot be determined accurately by this method.

  4. Determination of volume fraction in biphasic flows oil-gas and water-gas using artificial neural network and gamma densitometry; Determinacao de fracoes de volume em fluxos bifasicos oleo-gas e agua-gas utilizando redes neurais artificiais e densitometria gama

    Energy Technology Data Exchange (ETDEWEB)

    Peixoto, Philippe Netto Belache

    2016-07-01

    This study presents a methodology based on the principles of gamma ray attenuation to identify volume fractions in biphasic systems composed of oil-gas-water and gas which are found in the offshore oil industry. This methodology is based on the acknowledgment counts per second on the photopeak energy using a detection system composed of a NaI (Tl) detector, a source of {sup 137}Cs without collimation positioned at 180 ° relative to the detector on a smooth stratified flow regime. The mathematical modeling for computational simulation using the code MCNP-X was performed using the experimental measurements of the detector characteristics (energy resolution and efficiency), characteristics of the material water and oil (density and coefficient attenuation) and measurement of the volume fractions. To predict these fractions were used artificial neural networks (ANNs), and to obtain an adequate training the ANNs for the prediction of volume fractions were simulated a larger number of volume fractions in MCNP-X. The experimental data were used in the set data necessary for validation of ANNs and the data generated using the computer code MCNP-X were used in training and test sets of the ANNs. Were used ANNs of type feed-forward Multilayer Perceptron (MLP) and analyzed two functions of training, Levenberg-Marquardt (LM) and gradient descent with momentum (GDM), both using the Backpropagation training algorithm. The ANNs identified correctly the volume fractions of the multiphase system with mean relative errors lower than 1.21 %, enabling the application of this methodology for this purpose. (author)

  5. Defect Detection in Fuel Cell Gas Diffusion Electrodes Using Infrared Thermography

    Energy Technology Data Exchange (ETDEWEB)

    Ulsh, Michael; Porter, Jason M.; Bittinat, Daniel C.; Bender, Guido

    2016-04-01

    Polymer electrolyte membrane fuel cells are energy conversion devices that offer high power densities and high efficiencies for mobile and other applications. Successful introduction into the marketplace requires addressing cost barriers such as production volumes and platinum loading. For cost reduction, it is vital to minimize waste and maximize quality during the manufacturing of platinum-containing electrodes, including gas diffusion electrodes (GDEs). In this work, we report on developing a quality control diagnostic for GDEs, involving creating an ex situ exothermic reaction on the electrode surface and using infrared thermography to measure the resulting temperature profile. Experiments with a moving GDE containing created defects were conducted to demonstrate the applicability of the diagnostic for real-time web-line inspection.

  6. Calibration of effective optical path length for hollow-waveguide based gas cell using absorption spectroscopy

    Science.gov (United States)

    Liu, Lin; Du, Zhenhui; Li, Jinyi

    2016-10-01

    The Hollow Waveguide (HWG) has emerged as a novel tool to transmit laser power. Owing to its long Effective Optical Path Length (EOPL) within a relatively small volume, it is suitable for the application as a gas cell in concentration measurement by using laser spectroscopy. The measurement of effective optical path length for a hollow waveguide, which possesses the physical length of 284.0 cm, by using Tunable Diode Laser Absorption Spectroscopy (TDLAS) was demonstrated. Carbon dioxide was used as a sample gas for a hollow waveguide calibration. A 2004 nm Distributed Feed-Back (DFB) laser was used as the light source to cover a CO2 line near 2003 nm, which was selected as the target line in the measurement. The reference direct absorption spectroscopy signal was obtained by delivering CO2 into a reference cell possessing a length of 29.4 cm. Then the effective optical path length of HWG was calculated by least-squares fitting the measured absorption signal to the reference absorption signal. The measured EOPL of HWG was 282.8 cm and the repeatability error of effective optical path length was calculated as 0.08 cm. A detection limit of 0.057 cm (with integral time 5 s) characterized by the Allan variance, was derived. The effective optical path length is obtained as the significant parameter to calculate the concentration of gases and it is of great importance to precise measurement of absorption spectroscopy.

  7. Transient Modeling of the NETL Hybrid Fuel Cell/Gas Turbine Facility and Experimental Validation

    Energy Technology Data Exchange (ETDEWEB)

    Ferrari, M.L. (Università di Genova, Genova, Italy); Liese, E.A.; Tucker, D.A.; Lawson, L.O.; Traverso, A. (Università di Genova, Genova, Italy); Massardo, A.F. (Università di Genova, Genova, Italy)

    2007-10-01

    This paper describes the experimental validation of two different transient models of the hybrid fuel cell/gas turbine facility of the U.S. DOE-NETL at Morgantown. The first part of this work is devoted to the description of the facility, designed to experimentally investigate these plants with real components, except the fuel cell. The behavior of the SOFC is obtained with apt volumes (for the stack and the off-gas burner) and using a combustor to generate similar thermal effects. The second part of this paper shows the facility real-time transient model developed at the U.S. DOE-NETL and the detailed transient modeling activity using the TRANSEO program developed at TPG. The results obtained with both models are successfully compared with the experimental data of two different load step decreases. The more detailed model agrees more closely with the experimental data, which, of course, is more time consuming than the real-time model (the detailed model operates with a calculation over calculated time ratio around 6). Finally, the TPG model has been used to discuss the importance of performance map precision for both compressor and turbine. This is an important analysis to better understand the steady-state difference between the two models

  8. Transient Modeling of the NETL Hybrid Fuel Cell/Gas Turbine Facility and Experimental Validation

    Energy Technology Data Exchange (ETDEWEB)

    Mario L. Ferrari; Eric Liese; David Tucker; Larry Lawson; Alberto Traverso; Aristide F. Massardo

    2007-10-01

    This paper describes the experimental validation of two different transient models of the hybrid fuel cell/gas turbine facility of the U.S. DOE-NETL at Morgantown. The first part of this work is devoted to the description of the facility, designed to experimentally investigate these plants with real components, except the fuel cell. The behavior of the SOFC is obtained with apt volumes (for the stack and the off-gas burner) and using a combustor to generate similar thermal effects. The second part of this paper shows the facility real-time transient model developed at the U.S. DOE-NETL and the detailed transient modeling activity using the TRANSEO program developed at TPG. The results obtained with both models are successfully compared with the experimental data of two different load step decreases. The more detailed model agrees more closely with the experimental data, which, of course, is more time consuming than the real-time model (the detailed model operates with a calculation over calculated time ratio around 6). Finally, the TPG model has been used to discuss the importance of performance map precision for both compressor and turbine. This is an important analysis to better understand the steady-state difference between the two models.

  9. Unconventional oil and gas spills: Materials, volumes, and risks to surface waters in four states of the U.S.

    Science.gov (United States)

    Maloney, Kelly O.; Baruch-Mordo, Sharon; Patterson, Lauren A.; Nicot, Jean-Philippe; Entrekin, Sally; Fargione, Joe E.; Kiesecker, Joseph M.; Konschnik, Kate E.; Ryan, Joseph N.; Trainor, Anne M.; Saiers, James E.; Wiseman, Hannah J.

    2017-01-01

    Extraction of oil and gas from unconventional sources, such as shale, has dramatically increased over the past ten years, raising the potential for spills or releases of chemicals, waste materials, and oil and gas. We analyzed spill data associated with unconventional wells from Colorado, New Mexico, North Dakota and Pennsylvania from 2005 to 2014, where we defined unconventional wells as horizontally drilled into an unconventional formation. We identified materials spilled by state and for each material we summarized frequency, volumes and spill rates. We evaluated the environmental risk of spills by calculating distance to the nearest stream and compared these distances to existing setback regulations. Finally, we summarized relative importance to drinking water in watersheds where spills occurred. Across all four states, we identified 21,300 unconventional wells and 6622 reported spills. The number of horizontal well bores increased sharply beginning in the late 2000s; spill rates also increased for all states except PA where the rate initially increased, reached a maximum in 2009 and then decreased. Wastewater, crude oil, drilling waste, and hydraulic fracturing fluid were the materials most often spilled; spilled volumes of these materials largely ranged from 100 to 10,000 L. Across all states, the average distance of spills to a stream was highest in New Mexico (1379 m), followed by Colorado (747 m), North Dakota (598 m) and then Pennsylvania (268 m), and 7.0, 13.3, and 20.4% of spills occurred within existing surface water setback regulations of 30.5, 61.0, and 91.4 m, respectively. Pennsylvania spills occurred in watersheds with a higher relative importance to drinking water than the other three states. Results from this study can inform risk assessments by providing improved input parameters on volume and rates of materials spilled, and guide regulations and the management policy of spills.

  10. Quantitative absorption cytometry for measuring red blood cell hemoglobin mass and volume.

    Science.gov (United States)

    Schonbrun, Ethan; Malka, Roy; Di Caprio, Giuseppe; Schaak, Diane; Higgins, John M

    2014-04-01

    We present an optical system, called the quantitative absorption cytometer (QAC), to measure the volume and hemoglobin mass of red blood cells flowing through a microfluidic channel. In contrast to clinical hematology analyzers, where cells are sphered in order for both volume and hemoglobin to be measured accurately, the QAC measures cells in their normal physiological shape. Human red blood cells are suspended in a refractive index-matching absorbing buffer, driven through a microfluidic channel, and imaged using a transmission light microscope onto a color camera. A red and a blue LED illuminate cells and images at each color are used to independently retrieve cell volume and hemoglobin mass. This system shows good agreement with red blood cell indices retrieved by a clinical hematology analyzer and in fact measures a smaller coefficient of variation of hemoglobin concentration. In addition to cell indices, the QAC returns height and mass maps of each measured cell. These quantitative images are valuable for analyzing the detailed morphology of individual cells as well as statistical outliers found in the data. We also measured red blood cells in hypertonic and hypotonic buffers to quantify the correlation between volume and hemoglobin mass under osmotic stress. Because this method is invariant to cell shape, even extremely nonspherical cells in hypertonic buffers can be measured accurately.

  11. Multivariable Robust Control of a Simulated Hybrid Solid Oxide Fuel Cell Gas Turbine Plant

    Energy Technology Data Exchange (ETDEWEB)

    Tsai A, Banta L, Tucker D

    2010-08-01

    This work presents a systematic approach to the multivariable robust control of a hybrid fuel cell gas turbine plant. The hybrid configuration under investigation built by the National Energy Technology Laboratory comprises a physical simulation of a 300kW fuel cell coupled to a 120kW auxiliary power unit single spool gas turbine. The public facility provides for the testing and simulation of different fuel cell models that in turn help identify the key difficulties encountered in the transient operation of such systems. An empirical model of the built facility comprising a simulated fuel cell cathode volume and balance of plant components is derived via frequency response data. Through the modulation of various airflow bypass valves within the hybrid configuration, Bode plots are used to derive key input/output interactions in transfer function format. A multivariate system is then built from individual transfer functions, creating a matrix that serves as the nominal plant in an H{sub {infinity}} robust control algorithm. The controller’s main objective is to track and maintain hybrid operational constraints in the fuel cell’s cathode airflow, and the turbo machinery states of temperature and speed, under transient disturbances. This algorithm is then tested on a Simulink/MatLab platform for various perturbations of load and fuel cell heat effluence. As a complementary tool to the aforementioned empirical plant, a nonlinear analytical model faithful to the existing process and instrumentation arrangement is evaluated and designed in the Simulink environment. This parallel task intends to serve as a building block to scalable hybrid configurations that might require a more detailed nonlinear representation for a wide variety of controller schemes and hardware implementations.

  12. Role of BK channels in the apoptotic volume decrease in native eel intestinal cells

    DEFF Research Database (Denmark)

    Lionetto, Maria Giulia; Giordano, Maria Elena; Calisi, Antonio

    2010-01-01

    of these channels in the Apoptotic Volume Decrease (AVD) of isolated eel enterocytes, and the possible interaction between BK channels and the progression of apoptosis. The detection of apoptosis was performed by confocal microscopy and annexin V and propidium iodide labelling; cell volume changes were monitored...

  13. Field monitoring and evaluation of a residential gas-engine-driven heat pump: Volume 2, Heating season

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J.D.

    1995-11-01

    The Federal Government is the largest single energy consumer in the United States; consumption approaches 1.5 quads/year of energy (1 quad = 10{sup 15} Btu) at a cost valued at nearly $10 billion annually. The US Department of Energy (DOE) Federal Energy Management Program (FEMP) supports efforts to reduce energy use and associated expenses in the Federal sector. One such effort, the New Technology Demonstration Program (NTDP), seeks to evaluate new energy-saving US technologies and secure their more timely adoption by the US Government. Pacific Northwest Laboratory (PNL) is one of four DOE national multiprogram laboratories that participate in the NTDP by providing technical expertise and equipment to evaluate new, energy-saving technologies being studied and evaluated under that program. This two-volume report describes a field evaluation that PNL conducted for DOE/FEMP and the US Department of Defense (DoD) Strategic Environmental Research and Development Program (SERDP) to examine the performance of a candidate energy-saving technology -- a gas-engine-driven heat pump. The unit was installed at a single residence at Fort Sam Houston, a US Army base in San Antonio, Texas, and the performance was monitored under the NTDP. Participating in this effort under a Cooperative Research and Development Agreement (CRADA) were York International, the heat pump manufacturer; Gas Research Institute (GRI), the technology developer; City Public Service of San Antonio, the local utility; American Gas Cooling Center (AGCC); Fort Sam Houston; and PNL.

  14. Field monitoring and evaluation of a residential gas-engine-driven heat pump: Volume 1, Cooling season

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J.D.

    1995-09-01

    The Federal government is the largest single energy consumer in the United States; consumption approaches 1.5 quads/year of energy (1 quad = 10{sup 15} Btu) at a cost valued at nearly $10 billion annually. The US Department of Energy (DOE) Federal Energy Management Program (FEMP) supports efforts to reduce energy use and associated expenses in the Federal sector. One such effort, the New Technology Demonstration Program (NTDP), seeks to evaluate new energy-saving US technologies and secure their more timely adoption by the US government. Pacific Northwest Laboratory (PNL)is one of four DOE national multiprogram laboratories that participate in the NTDP by providing technical expertise and equipment to evaluate new, energy-saving technologies being studied and evaluated under that program. This two-volume report describes a field evaluation that PNL conducted for DOE/FEMP and the US Department of Defense (DoD) Strategic Environmental Research and Development Program (SERDP) to examine the performance of a candidate energy-saving technology -- a gas-engine-driven heat pump. The unit was installed at a single residence at Fort Sam Houston, a US Army base in San Antonio, Texas, and the performance was monitored under the NTDP. Participating in this effort under a Cooperative Research and Development Agreement (CRADA) were York International, the heat pump manufacturer, Gas Research Institute (GRI), the technology developer; City Public Service of San Antonio, the local utility; American Gas Cooling Center (AGCC); Fort Sam Houston; and PNL.

  15. Effects of Lugol's iodine solution and formalin on cell volume of three bloom-forming dinoflagellates

    Science.gov (United States)

    Yang, Yang; Sun, Xiaoxia; Zhao, Yongfang

    2016-09-01

    Fixatives are traditionally used in marine ecosystem research. The bias introduced by fixatives on the dimensions of plankton cells may lead to an overestimation or underestimation of the carbon biomass. To determine the impact of traditional fixatives on dinoflagellates during short- and long-term fixation, we analyzed the degree of change in three bloom-forming dinoflagellates (Prorocentrum micans, Scrippsiella trochoidea and Noctiluca scintillans) brought about by Lugol's iodine solution (hereafter Lugol's) and formalin. The fixation effects were species-specific. P. micans cell volume showed no significant change following long-term preservation, and S. trochoidea swelled by approximately 8.06% in Lugol's and by 20.97% in formalin as a percentage of the live cell volume, respectively. N. scintillans shrank significantly in both fixatives. The volume change due to formalin in N. scintillans was not concentration-dependent, whereas the volume shrinkage of N. scintillans cells fixed with Lugol's at a concentration of 2% was nearly six-fold that in cells fixed with Lugol's at a concentration of 0.6%-0.8%. To better estimate the volume of N. scintillans fixed in formalin at a concentration of 5%, we suggest that the conversion relationship was as follows: volume of live cell=volume of intact fixed cell/0.61. Apart from size change, damage induced by fixatives on N. scintillans was obvious. Lugol's is not a suitable fixative for N. scintillans due to high frequency of broken cells. Accurate carbon biomass estimate of N. scintillans should be performed on live samples. These findings help to improve the estimate of phytoplankton cell volume and carbon biomass in marine ecosystem.

  16. Gas content of a two-phase layer containing gas and a melt of K/sub 2/O-V/sub 2/O/sub 8/ averaged by volume and its foam formation in a reaction-regeneration cycle

    Energy Technology Data Exchange (ETDEWEB)

    Fazleev, M.P.; Chekhov, O.S.; Ermakov, E.A.

    1985-06-20

    This paper discusses the results of an investigation of the gas content averaged over the volume, hydrodynamic programs, and foaming in the K/sub 2/O-V/sub 2/O/sub 5/ melt plus gas system, which is used as a catalyst in several thermocatalytic processes. The experimental setup is described and a comparison of literature data on the gas content of different gas-liquid systems under comparable conditions is presented. The authors were able to determine the boundaries of the hydrodynamic modes in a bubbling reactor and derive equations for the calculation of the gas content. It was found that the gas content of the melt increased when V/sub 2/O/sub 5/ was reduced to V/sub 2/O/sub 4/ in the reaction portion of the reaction-regeneration cycle. Regeneration of the melt restores the value of gas content to its original level.

  17. Impact of compression on gas transport in non-woven gas diffusion layers of high temperature polymer electrolyte fuel cells

    Science.gov (United States)

    Froning, Dieter; Yu, Junliang; Gaiselmann, Gerd; Reimer, Uwe; Manke, Ingo; Schmidt, Volker; Lehnert, Werner

    2016-06-01

    Gas transport in non-woven gas diffusion layers of a high-temperature polymer electrolyte fuel cell was calculated with the Lattice Boltzmann method. The underlying micro structure was taken from two sources. A real micro structure was analyzed in the synchrotron under the impact of a compression mask mimicking the channel/rib structure of a flow field. Furthermore a stochastic geometry model based on synchrotron X-ray tomography studies was applied. The effect of compression is included in the stochastic model. Gas transport in these micro structures was simulated and the impact of compression was analyzed. Fiber bundles overlaying the micro structure were identified which affect the homogeneity of the gas flow. There are significant deviations between the impact of compression on effective material properties for this type of gas diffusion layers and the Kozeny-Carman equation.

  18. Regulatory Volume Decrease in Neural Precursor Cells: Taurine Efflux and Gene Microarray Analysis

    Directory of Open Access Journals (Sweden)

    Reyna Hernández-Benítez

    2014-11-01

    Full Text Available Background/Aims: Neural stem/ progenitor cells (NPCs endure important changes in cell volume during growth, proliferation and migration. As a first approach to know about NPC response to cell volume changes, the Regulatory Volume Decrease (RVD subsequent to hypotonic swelling was investigated. Methods: NPCs obtained from the mesencephalon and the subventricular zone of embryonic and adult mice, respectively, were grown and cultured as neurospheres. Cell volume changes were measured by large-angle light-scattering and taurine efflux by [3H]-taurine. Expression of genes encoding molecules related to RVD was analysed using a DNA microarray obtained from NPC samples. Results: Embryonic and adult NPCs exposed to osmolarity reduction (H15, H30, H40 exhibited rapid swelling followed by RVD. The magnitude, efficiency and pharmacological profile, of RVD and of [3H]-taurine osmosensitive efflux were comparable to those found in cultured brain cells, astrocytes and neurons. The relative expression of genes encoding molecules related to volume regulation, i.e. K+ and Cl- channels, cotransporters, exchangers and aquaporins were identified in NPCs. Conclusion: NPCs show the ability to respond to hypotonic-evoked volume changes by adaptative recovery processes, similar to those found in other cultured brain cells. Genes related to molecules involved in RVD were found expressed in NPCs.

  19. Airborne Astronomy Symposium on the Galactic Ecosystem: From Gas to Stars to Dust, volume 73

    Science.gov (United States)

    Haas, Michael R. (Editor); Davidson, Jacqueline A. (Editor); Erickson, Edwin F. (Editor)

    1995-01-01

    This symposium was organized to review the science related to NASA's Airborne Astronomy Program on the occasion of the twentieth anniversary of the Kuiper Airborne Observatory (KAO). The theme selected, 'The Galactic Ecosystem: From Gas to Stars to Dust,' was considered to capture the underlying commonality of much of the research discussed. The 8 sessions were as follows: The Interstellar Medium; The Life Cycle of the ISM in Other Galaxies; Star and Planetary System Formation; Our Planetary System: The Solar System; The Enrichment of the Interstellar Medium; The Galactic Center: A Unique Region of the Galactic Ecosystem; Instrumentation for Airborne Astronomy; KAO History and Education; and Missions and the Future of Infrared Astronomy.

  20. Blade loss transient dynamics analysis, volume 1. Task 1: Survey and perspective. [aircraft gas turbine engines

    Science.gov (United States)

    Gallardo, V. C.; Gaffney, E. F.; Bach, L. J.; Stallone, M. J.

    1981-01-01

    An analytical technique was developed to predict the behavior of a rotor system subjected to sudden unbalance. The technique is implemented in the Turbine Engine Transient Rotor Analysis (TETRA) computer program using the component element method. The analysis was particularly aimed toward blade-loss phenomena in gas turbine engines. A dual-rotor, casing, and pylon structure can be modeled by the computer program. Blade tip rubs, Coriolis forces, and mechanical clearances are included. The analytical system was verified by modeling and simulating actual test conditions for a rig test as well as a full-engine, blade-release demonstration.

  1. A novel geotechnical/geostatistical approach for exploration and production of natural gas from multiple geologic strata, Phase 1. Volume 2, Geology and engineering

    Energy Technology Data Exchange (ETDEWEB)

    Overbey, W.K. Jr.; Reeves, T.K.; Salamy, S.P.; Locke, C.D.; Johnson, H.R.; Brunk, R.; Hawkins, L. [BDM Engineering Services Co., Morgantown, WV (United States)

    1991-05-01

    This research program has been designed to develop and verify a unique geostatistical approach for finding natural gas resources. The project has been conducted by Beckley College, Inc., and BDM Engineering Services Company (BDMESC) under contract to the US Department of Energy (DOE), Morgantown Energy Technology Center (METC). This section, Volume II, contains a detailed discussion of the methodology used and the geological and production information collected and analyzed for this study. A companion document, Volume 1, provides an overview of the program, technique and results of the study. In combination, Volumes I and II cover the completion of the research undertaken under Phase I of this DOE project, which included the identification of five high-potential sites for natural gas production on the Eccles Quadrangle, Raleigh County, West Virginia. Each of these sites was selected for its excellent potential for gas production from both relatively shallow coalbeds and the deeper, conventional reservoir formations.

  2. A novel geotechnical/geostatistical approach for exploration and production of natural gas from multiple geologic strata, Phase 1. Volume 2, Geology and engineering

    Energy Technology Data Exchange (ETDEWEB)

    Overbey, W.K. Jr.; Reeves, T.K.; Salamy, S.P.; Locke, C.D.; Johnson, H.R.; Brunk, R.; Hawkins, L. [BDM Engineering Services Co., Morgantown, WV (United States)

    1991-05-01

    This research program has been designed to develop and verify a unique geostatistical approach for finding natural gas resources. The project has been conducted by Beckley College, Inc., and BDM Engineering Services Company (BDMESC) under contract to the US Department of Energy (DOE), Morgantown Energy Technology Center (METC). This section, Volume II, contains a detailed discussion of the methodology used and the geological and production information collected and analyzed for this study. A companion document, Volume 1, provides an overview of the program, technique and results of the study. In combination, Volumes I and II cover the completion of the research undertaken under Phase I of this DOE project, which included the identification of five high-potential sites for natural gas production on the Eccles Quadrangle, Raleigh County, West Virginia. Each of these sites was selected for its excellent potential for gas production from both relatively shallow coalbeds and the deeper, conventional reservoir formations.

  3. Industrial Fuel Gas Demonstration Plant Program. Volume II. Commercial plant design (Deliverable Nos. 15 and 16)

    Energy Technology Data Exchange (ETDEWEB)

    1978-01-01

    This report presents a Conceptual Design and Evaluation of Commercial Plant report in four volumes as follows: I - Executive Summary, II - Commercial Plant Design, III - Economic Analyses, IV - Demonstration Plant Recommendations. Volume II presents the commercial plant design and various design bases and design analyses. The discussion of design bases includes definition of plant external and internal considerations. The basis is described for process configuration selection of both process units and support facilities. Overall plant characteristics presented include a summary of utilities/chemicals/catalysts, a plant block flow diagram, and a key plot plan. Each process unit and support facility is described. Several different types of process analyses are presented. A synopsis of environmental impact is presented. Engineering requirements, including design considerations and materials of construction, are summarized. Important features such as safety, startup, control, and maintenance are highlighted. The last section of the report includes plant implementation considerations that would have to be considered by potential owners including siting, coal and water supply, product and by-product characteristics and uses, overall schedule, procurement, construction, and spare parts and maintenance philosophy.

  4. Large volume injection in gas chromatography using the through oven transfer adsorption desorption interface operating under vacuum.

    Science.gov (United States)

    Aragón, Álvaro; Toledano, Rosa M; Gea, Sara; Cortés, José M; Vázquez, Ana M; Villén, Jesús

    2014-06-01

    The present work describes a modification of the Through Oven Transfer Adsorption Desorption (TOTAD) interface, consisting of coupling a vacuum system to reduce the consumption of the helium needed to totally remove the eluent for large volume injection (LVI) in gas chromatography (GC). Two different retention materials in the liner of the TOTAD interface were evaluated: Tenax TA, which was seen to be unsuitable for working under vacuum conditions, and polydimethylsiloxane (PDMS), which provided satisfactory repeatability as well as a good sensitivity. No variability was observed in the retention times in either case. Solutions containing organophosphorous pesticides in two different solvents, a polar (methanol/water) and a non-polar (hexane) solvent, were used to evaluate the modification. The vacuum system coupled to the TOTAD interface allowed up to 90% helium to be saved without affecting the performance.

  5. Volume regulation in rat pheochromocytoma cultured cells submitted to hypoosmotic conditions.

    Science.gov (United States)

    Delpire, E; Cornet, M; Gilles, R

    1991-02-01

    The mechanisms at work in cell volume regulation have been studied in PC12 cultured cells. Results show, for the first time to our knowledge, that the volume readjustment process occurring after application of a hypoosmotic saline is sensitive to amiloride, IBMX and forskoline. The process is also inhibited by quinine hydrochloride and trifluoperazine. Volume readjustment is concomtant with a decrease in K+ and Cl- intracellular levels. The decrease in K+ level can be related to an assymetrical change in the fluxes in and out of the ion as shown by flux kinetics studies using Rb86. These results are interpreted considering that the control of the activity of the ion channel pathways associated with volume readjustment in PC12 cells may implicate the Ca(2+)-calmodulin - cAMP system.

  6. Anions Govern Cell Volume: A Case Study of Relative Astrocytic and Neuronal Swelling in Spreading Depolarization.

    Directory of Open Access Journals (Sweden)

    Niklas Hübel

    Full Text Available Cell volume changes are ubiquitous in normal and pathological activity of the brain. Nevertheless, we know little about the dynamics of cell and tissue swelling, and the differential changes in the volumes of neurons and glia during pathological states such as spreading depolarizations (SD under ischemic and non-ischemic conditions, and epileptic seizures. By combining the Hodgkin-Huxley type spiking dynamics, dynamic ion concentrations, and simultaneous neuronal and astroglial volume changes into a comprehensive model, we elucidate why glial cells swell more than neurons in SD and the special case of anoxic depolarization (AD, and explore the relative contributions of the two cell types to tissue swelling. Our results demonstrate that anion channels, particularly Cl-, are intrinsically connected to cell swelling and blocking these currents prevents changes in cell volume. The model is based on a simple and physiologically realistic description. We introduce model extensions that are either derived purely from first physical principles of electroneutrality, osmosis, and conservation of particles, or by a phenomenological combination of these principles and known physiological facts. This work provides insights into numerous studies related to neuronal and glial volume changes in SD that otherwise seem contradictory, and is broadly applicable to swelling in other cell types and conditions.

  7. Effect of Gas Phase Transport in Molten Carbonate Fuel Cell (I)

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C.G.; Lim, H.C. [Korea Electric Power Research Institute, Taejon (Korea)

    1999-07-01

    The mass transfer effect in gas phase of molten carbonate fuel cell (MCFC) has not been profoundly studied. We have tried to investigate it with disturbance of reactant gas flow. An inert gas was added into anode and cathode reactant gas streams, and the resulting voltage shifts were analyzed. The disturbance of reactant gas was carried out at different reactant and inert gas flow rates, and current density. The results express that the anode performance is profoundly influenced by mass transfer in gas phase while the cathode is not. Moreover, the quantitative analysis of mass transfer effect in gas phase was available by means of the inert gas disturbance. The method led to the separate analyses of mass transfer effect in cell. The effects of mass transfer in gas channel and porous electrode regions were measured by changing gas channel depth and electrode thickness. It was found that mass transfer resistance in anode takes place mainly in porous electrode. Meanwhile the voltage shifts in cathode represented both gas and liquid phase mass transfer effect separately. It was also found that the mass transfer resistance in gas phase is insignificant in cathode compared with that in anode. The voltage shift values, which mean mass transfer resistance in liquid phase, depended on oxidant gas composition. It implies that the cathode reaction in MCFC would be an O{sub 2} and CO{sub 2} mixed diffusion control process. (author). 11 refs., 5 figs.

  8. Kinetic assay shows that increasing red cell volume could be a treatment for sickle cell disease

    Science.gov (United States)

    Li, Quan; Henry, Eric R.; Hofrichter, James; Smith, Jeffrey F.; Cellmer, Troy; Dunkelberger, Emily B.; Metaferia, Belhu B.; Jones-Straehle, Stacy; Boutom, Sarah; Christoph, Garrott W.; Wakefield, Terri H.; Link, Mary E.; Staton, Dwayne; Vass, Erica R.; Miller, Jeffery L.; Hsieh, Matthew M.; Tisdale, John F.; Eaton, William A.

    2017-01-01

    Although it has been known for more than 60 years that the cause of sickle cell disease is polymerization of a hemoglobin mutant, hydroxyurea is the only drug approved for treatment by the US Food and Drug Administration. This drug, however, is only partially successful, and the discovery of additional drugs that inhibit fiber formation has been hampered by the lack of a sensitive and quantitative cellular assay. Here, we describe such a method in a 96-well plate format that is based on laser-induced polymerization in sickle trait cells and robust, automated image analysis to detect the precise time at which fibers distort (“sickle”) the cells. With this kinetic method, we show that small increases in cell volume to reduce the hemoglobin concentration can result in therapeutic increases in the delay time prior to fiber formation. We also show that, of the two drugs (AES103 and GBT440) in clinical trials that inhibit polymerization by increasing oxygen affinity, one of them (GBT440) also inhibits sickling in the absence of oxygen by two additional mechanisms. PMID:28096387

  9. The presence of hydrogenotrophic methanogens in the inoculum improves methane gas production in microbial electrolysis cells.

    KAUST Repository

    Siegert, Michael

    2014-01-01

    High current densities in microbial electrolysis cells (MECs) result from the predominance of various Geobacter species on the anode, but it is not known if archaeal communities similarly converge to one specific genus. MECs were examined here on the basis of maximum methane production and current density relative to the inoculum community structure. We used anaerobic digester (AD) sludge dominated by acetoclastic Methanosaeta, and an anaerobic bog sediment where hydrogenotrophic methanogens were detected. Inoculation using solids to medium ratio of 25% (w/v) resulted in the highest methane production rates (0.27 mL mL(-1) cm(-2), gas volume normalized by liquid volume and cathode projected area) and highest peak current densities (0.5 mA cm(-2)) for the bog sample. Methane production was independent of solid to medium ratio when AD sludge was used as the inoculum. 16S rRNA gene community analysis using pyrosequencing and quantitative PCR confirmed the convergence of Archaea to Methanobacterium and Methanobrevibacter, and of Bacteria to Geobacter, despite their absence in AD sludge. Combined with other studies, these findings suggest that Archaea of the hydrogenotrophic genera Methanobacterium and Methanobrevibacter are the most important microorganisms for methane production in MECs and that their presence in the inoculum improves the performance.

  10. A Computer Simulation of the Effect of the Inert Gas Volume Fraction in Low-Caloric Biogas on the Performance of an Engine

    Directory of Open Access Journals (Sweden)

    Choong Hoon Lee

    2015-10-01

    Full Text Available A computer simulation of a gas engine was performed to investigate the effects of the inert gas volume fraction in biogas on engine performance, specifically the engine torque and the brakespecific fuel consumption (BSFC using GT-Power®. The engine speeds used in the simulation were 900 and 1800 rpm, while the simulated engine loads were 25, 50, 75 and 100%. The volume fraction of the inert gas N2 in the biogas was varied from 20 to 80% with an interval of 10%. In a simulation of a naturally aspirated gas engine which is operated with an 80% volume fraction of N2 in biogas, the optimal air-fuel ratio in terms of the fuel economy and brake power generation was 3.5. In a simulation of a turbo intercooler gas engine operated with an 80% volume fraction of N2 in biogas, the optimal air-fuel ratios with regard to the fuel economy and brake power generation were 5.0 and 3.5, respectively.

  11. The presence of hydrogenotrophic methanogens in the inoculum improves methane gas production in microbial electrolysis cells

    Directory of Open Access Journals (Sweden)

    Michael eSiegert

    2015-01-01

    Full Text Available High current densities in microbial electrolysis cells (MECs result from the predominance of various Geobacter species on the anode. MECs inoculated from different sources often converge in terms of current production and predominance of Geobacter species despite variability in the inoculum community. Relatively less is known about the effects of inoculum source on methane gas production in MECs, and specifically whether archaeal communities similarly converge to one specific genus. MECs were examined here on the basis of maximum methane production and current density relative to the inoculum community structure. We used anaerobic digester (AD sludge dominated by acetoclastic Methanosaeta species, and an anaerobic bog sediment where hydrogenotrophic methanogens were detected. Inoculation using solids to medium ratio of 25% w/v resulted in the highest methane production rates (0.27 mL mL–1 cm–2, gas volume normalized by liquid volume and cathode projected area and highest peak current densities (0.5 mA cm–2 for the bog sample. Methane production was independent of solid to medium ratio when AD sludge was used as the inoculum. 16S rRNA gene community analysis using pyrosequencing and qPCR confirmed the convergence of Archaea to Methanobacterium and Methanobrevibacter, and of Bacteria to Geobacter, despite their absence in AD sludge. Combined with other studies, these findings suggest that Archaea of the hydrogenotrophic genera Methanobacterium and Methanobrevibacter are the most important microorganisms for methane production in MECs and that their presence in the inoculum improves the performance.

  12. Dynamic Simulation of Carbonate Fuel Cell-Gas Turbine Hybrid Systems

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, R.A. (U. of California, Irvine, CA); Brouwer, J. (U. of California, Irvine, CA); Liese, E.A.; Gemmen, R.S.

    2006-04-01

    Hybrid fuel cell/gas turbine systems provide an efficient means of producing electricity from fossil fuels with ultra low emissions. However, there are many significant challenges involved in integrating the fuel cell with the gas turbine and other components of this type of system. The fuel cell and the gas turbine must maintain efficient operation and electricity production while protecting equipment during perturbations that may occur when the system is connected to the utility grid or in stand-alone mode. This paper presents recent dynamic simulation results from two laboratories focused on developing tools to aid in the design and dynamic analyses of hybrid fuel cell systems. The simulation results present the response of a carbonate fuel cell/gas turbine, or molten carbonate fuel cell/gas turbine, (MCFC/GT) hybrid system to a load demand perturbation. Initial results suggest that creative control strategies will be needed to ensure a flexible system with wide turndown and robust dynamic operation.

  13. Advanced Flue Gas Desulfurization (AFGD) demonstration project: Volume 2, Project performance and economics. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-04-30

    The project objective is to demonstrate removal of 90--95% or more of the SO{sub 2} at approximately one-half the cost of conventional scrubbing technology; and to demonstrate significant reduction of space requirements. In this project, Pure Air has built a single SO{sub 2} absorber for a 528-MWe power plant. The absorber performs three functions in a single vessel: prequencher, absorber, and oxidation of sludge to gypsum. Additionally, the absorber is of a co- current design, in which the flue gas and scrubbing slurry move in the same direction and at a relatively high velocity compared to conventional scrubbers. These features all combine to yield a state- of-the-art SO{sub 2} absorber that is more compact and less expensive than conventional scrubbers. The project incorporated a number of technical features including the injection of pulverized limestone directly into the absorber, a device called an air rotary sparger located within the base of the absorber, and a novel wastewater evaporation system. The air rotary sparger combines the functions of agitation and air distribution into one piece of equipment to facilitate the oxidation of calcium sulfite to gypsum. Additionally, wastewater treatment is being demonstrated to minimize water disposal problems inherent in many high-chloride coals. Bituminous coals primarily from the Indiana, Illinois coal basin containing 2--4.5% sulfur were tested during the demonstration. The Advanced Flue Gas Desulfurization (AFGD) process has demonstrated removal of 95% or more of the SO{sub 2} while providing a commercial gypsum by-product in lieu of solid waste. A portion of the commercial gypsum is being agglomerated into a product known as PowerChip{reg_sign} gypsum which exhibits improved physical properties, easier flowability and more user friendly handling characteristics to enhance its transportation and marketability to gypsum end-users.

  14. Development of gas diffusion layer using water based carbon slurry for proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Lin, J.F.; Liu, X.; Adame, A.; Villacorta, R. [Fuel Cell Research Laboratory, Engineering Technology Department, Arizona State University, Mesa, AZ 85212 (United States); Wertz, J. [Hollingsworth and Vose Co., A.K. Nicholson Research Lab, 219 Townsend Road, West Groton, MA 01472 (United States); Ahmad, R.; Thommes, M. [Quantachrome Instruments, 1900 Corporate Drive, Boynton Beach, FL 33426 (United States); Kannan, A.M., E-mail: amk@asu.ed [Fuel Cell Research Laboratory, Engineering Technology Department, Arizona State University, Mesa, AZ 85212 (United States)

    2011-01-01

    The micro-porous layer of gas diffusion layers (GDLs) was fabricated with the carbon slurry dispersed in water containing sodium dodecyl sulfate (SDS), by wire rod coating process. The aqueous carbon slurry with micelle-encapsulation was highly consistent and stable without losing any homogeneity even after adding polytetrafluoroethylene (PTFE) binder for hundreds of hours. The surface morphology, contact angle and pore size distribution of the GDLs were examined using SEM, Goniometer and Hg Porosimeter, respectively. GDLs fabricated with various SDS concentrations were assembled into MEAs and evaluated in a single cell PEMFC under diverse operating relative humidity (RH) conditions using H{sub 2}/O{sub 2} and H{sub 2}/air as reactants. The peak power density of the single cell using the GDLs with optimum SDS concentration was 1400 and 500 mW cm{sup -2} with H{sub 2}/O{sub 2} and H{sub 2}/air at 90% RH, respectively. GDLs were also fabricated with isopropyl alcohol (IPA) based carbon slurry for fuel cell performance comparison. It was found that the composition of the carbon slurry, specifically SDS concentration played a critical role in controlling the pore diameter as well as the corresponding pore volumes of the GDLs.

  15. Quantitative analysis of rat adipose tissue cell recovery, and non-fat cell volume, in primary cell cultures

    Directory of Open Access Journals (Sweden)

    Floriana Rotondo

    2016-11-01

    Full Text Available Background White adipose tissue (WAT is a complex, diffuse, multifunctional organ which contains adipocytes, and a large proportion of fat, but also other cell types, active in defense, regeneration and signalling functions. Studies with adipocytes often require their isolation from WAT by breaking up the matrix of collagen fibres; however, it is unclear to what extent adipocyte number in primary cultures correlates with their number in intact WAT, since recovery and viability are often unknown. Experimental Design Epididymal WAT of four young adult rats was used to isolate adipocytes with collagenase. Careful recording of lipid content of tissue, and all fraction volumes and weights, allowed us to trace the amount of initial WAT fat remaining in the cell preparation. Functionality was estimated by incubation with glucose and measurement of glucose uptake and lactate, glycerol and NEFA excretion rates up to 48 h. Non-adipocyte cells were also recovered and their sizes (and those of adipocytes were measured. The presence of non-nucleated cells (erythrocytes was also estimated. Results Cell numbers and sizes were correlated from all fractions to intact WAT. Tracing the lipid content, the recovery of adipocytes in the final, metabolically active, preparation was in the range of 70–75%. Cells showed even higher metabolic activity in the second than in the first day of incubation. Adipocytes were 7%, erythrocytes 66% and other stromal (nucleated cells 27% of total WAT cells. However, their overall volumes were 90%, 0.05%, and 0.2% of WAT. Non-fat volume of adipocytes was 1.3% of WAT. Conclusions The methodology presented here allows for a direct quantitative reference to the original tissue of studies using isolated cells. We have also found that the “live cell mass” of adipose tissue is very small: about 13 µL/g for adipocytes and 2 µL/g stromal, plus about 1 µL/g blood (the rats were killed by exsanguination. These data translate (with

  16. A combined gas cooled nuclear reactor and fuel cell cycle

    Science.gov (United States)

    Palmer, David J.

    Rising oil costs, global warming, national security concerns, economic concerns and escalating energy demands are forcing the engineering communities to explore methods to address these concerns. It is the intention of this thesis to offer a proposal for a novel design of a combined cycle, an advanced nuclear helium reactor/solid oxide fuel cell (SOFC) plant that will help to mitigate some of the above concerns. Moreover, the adoption of this proposal may help to reinvigorate the Nuclear Power industry while providing a practical method to foster the development of a hydrogen economy. Specifically, this thesis concentrates on the importance of the U.S. Nuclear Navy adopting this novel design for its nuclear electric vessels of the future with discussion on efficiency and thermodynamic performance characteristics related to the combined cycle. Thus, the goals and objectives are to develop an innovative combined cycle that provides a solution to the stated concerns and show that it provides superior performance. In order to show performance, it is necessary to develop a rigorous thermodynamic model and computer program to analyze the SOFC in relation with the overall cycle. A large increase in efficiency over the conventional pressurized water reactor cycle is realized. Both sides of the cycle achieve higher efficiencies at partial loads which is extremely important as most naval vessels operate at partial loads as well as the fact that traditional gas turbines operating alone have poor performance at reduced speeds. Furthermore, each side of the cycle provides important benefits to the other side. The high temperature exhaust from the overall exothermic reaction of the fuel cell provides heat for the reheater allowing for an overall increase in power on the nuclear side of the cycle. Likewise, the high temperature helium exiting the nuclear reactor provides a controllable method to stabilize the fuel cell at an optimal temperature band even during transients helping

  17. Effect of saline infusion for the maintenance of blood volume on pulmonary gas exchange during temporary abdominal aortic occlusion

    Directory of Open Access Journals (Sweden)

    F.F. Amorim

    2007-03-01

    Full Text Available We analyzed the effects of saline infusion for the maintenance of blood volume on pulmonary gas exchange in ischemia-reperfusion syndrome during temporary abdominal aortic occlusion in dogs. We studied 20 adult mongrel dogs weighing 12 to 23 kg divided into two groups: ischemia-reperfusion group (IRG, N = 10 and IRG submitted to saline infusion for the maintenance of mean pulmonary arterial wedge pressure between 10 and 20 mmHg (IRG-SS, N = 10. All animals were anesthetized and maintained on spontaneous ventilation. After obtaining baseline measurements, occlusion of the supraceliac aorta was performed by the inflation of a Fogarty catheter. After 60 min of ischemia, the balloon was deflated and the animals were observed for another 60 min of reperfusion. The measurements were made at 10 and 45 min of ischemia, and 5, 30, and 60 min of reperfusion. Pulmonary gas exchange was impaired in the IRG-SS group as demonstrated by the increase of the alveolar-arterial oxygen difference (21 ± 14 in IRG-SS vs 11 ± 8 in IRG after 60 min of reperfusion, P = 0.004 in IRG-SS in relation to baseline values and the decrease of oxygen partial pressure in arterial blood (58 ± 15 in IRG-SS vs 76 ± 15 in IRG after 60 min of reperfusion, P = 0.001 in IRG-SS in relation to baseline values, which was correlated with the highest degree of pulmonary edema in morphometric analysis (0.16 ± 0.06 in IRG-SS vs 0.09 ± 0.04 in IRG, P = 0.03 between groups. There was also a smaller ventilatory compensation of metabolic acidosis after the reperfusion. We conclude that infusion of normal saline worsened the gas exchange induced by pulmonary reperfusion injury in this experimental model.

  18. Development of a mathematical model for a single alkaline membrane fuel cell (AMFC) with fixed volume and general square section

    Energy Technology Data Exchange (ETDEWEB)

    Sommer, Elise Meister; Vargas, Jose Viriato Coelho [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Centro Politecnico. Setor de Tecnologia], Email: jvargas@demec.ufpr.br; Martins, Lauber de Souza; Ordonez, Juan Carlos [Florida State University, Tallahasse, FL (United States). Dept. of Mechanical Engineering and Center for Advanced Power Systems], Emails: martins@caps.fsu.edu, ordonez@eng.fsu.edu

    2010-07-01

    The Alkaline Membrane Fuel Cell (AMFC) is a recently developed fuel cell type, which has shown good experimental results in the laboratory. This paper introduces a mathematical model for the single AMFC with fixed volume and general square section. The main objective is to produce a reliable model (and computationally fast) to predict the response of the single AMFC according to variations of the physical properties of manufacturing materials and operating and design parameters. The model is based on mass, momentum, energy and species conservation, and electrochemical principles, and takes into account pressure drops in the gas channels and temperature gradients with respect to space in the flow direction. The simulation results comprise the AMFC temperature distribution, net power and polarization curves. It is shown that temperature spatial gradients and gas channels pressure drops significantly affect fuel cell performance. Such effects are not usually investigated in the models available in the literature, with most of them assuming uniform pressure and temperature operation. Therefore, the model is expected to be a useful tool for AMFC design and optimization. (author)

  19. Online gas composition estimation in solid oxide fuel cell systems with anode off-gas recycle configuration

    Science.gov (United States)

    Dolenc, B.; Vrečko, D.; Juričić, Ð.; Pohjoranta, A.; Pianese, C.

    2017-03-01

    Degradation and poisoning of solid oxide fuel cell (SOFC) stacks are continuously shortening the lifespan of SOFC systems. Poisoning mechanisms, such as carbon deposition, form a coating layer, hence rapidly decreasing the efficiency of the fuel cells. Gas composition of inlet gases is known to have great impact on the rate of coke formation. Therefore, monitoring of these variables can be of great benefit for overall management of SOFCs. Although measuring the gas composition of the gas stream is feasible, it is too costly for commercial applications. This paper proposes three distinct approaches for the design of gas composition estimators of an SOFC system in anode off-gas recycle configuration which are (i.) accurate, and (ii.) easy to implement on a programmable logic controller. Firstly, a classical approach is briefly revisited and problems related to implementation complexity are discussed. Secondly, the model is simplified and adapted for easy implementation. Further, an alternative data-driven approach for gas composition estimation is developed. Finally, a hybrid estimator employing experimental data and 1st-principles is proposed. Despite the structural simplicity of the estimators, the experimental validation shows a high precision for all of the approaches. Experimental validation is performed on a 10 kW SOFC system.

  20. Insensitivity of volume-sensitive chloride currents to chromones in human airway epithelial cells

    Science.gov (United States)

    Zegarra-Moran, Olga; Lantero, Sabina; Sacco, Oliviero; Rossi, Giovanni A; Galietta, Luis J V

    1998-01-01

    Chromones (sodium cromoglycate and sodium nedocromil) block cell swelling-activated Cl− channels in NIH-3T3 fibroblasts and endothelial cells. This has led to hypothesize that cell volume regulation might be involved in asthma pathogenesis.Using whole-cell patch-clamp experiments, we studied the effect of chromones on volume-sensitive Cl− currents in transformed human tracheal epithelial cells (9HTEo-) and in primary cultures of human bronchial epithelial cells (BE).Cl− currents activated by hypotonic shock were poorly blocked by extracellular nedocromil or cromoglycate. The block was voltage-dependent since it was observed only at positive membrane potentials. At the concentration of 5 mM, the current inhibition by both chromones at +80 mV was about 40% for 9HTEo- and only 20% for BE.Intracellular application of chromones elicited a voltage-independent inhibition in 9HTEo- cells. Under this condition, volume-sensitive Cl− currents were reduced at all membrane potentials (60 and 45% inhibition by 2 mM nedocromil and cromoglycate respectively). In contrast intracellular chromones were ineffective in BE cells.The relative refractoriness to chromones, in contrast with the high sensitivity shown by other Cl− channels, suggests that the epithelial volume-sensitive Cl− channel is not involved in asthma. PMID:9863671

  1. A compact and highly efficient natural gas fuel processor for 1-kW residential polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Lee, Doohwan; Lee, Hyun Chul; Lee, Kang Hee; Kim, Soonho

    A compact and highly efficient natural gas fuel processor for 1-kW residential polymer electrolyte membrane fuel cells (PEMFCs) has been developed at the Samsung Advanced Institute of Technology (SAIT). The fuel processor, referred to as SFP-2, consists of a natural gas reformer, a water-gas shift reactor, a heat-exchanger and a burner, in which the overall integrated volume including insulation is exceptionally small, namely, about 14 l. The SFP-2 produces hydrogen at 1000 l h -1 (STP) at full load with the carbon monoxide concentration in the process gas below 7000 ppmv (dry gas base). The maximum thermal efficiency is ∼78% (lower heating value) at full load and even ∼72% at 25% partial load. This fuel processor of small size with high thermal efficiency is one of the best such technologies for the above given H 2 throughputs. The time required for starting up the SFP-2 is within 20 min with the addition of external heating for the shift reactor. No additional medium, such as nitrogen, is required either for start-up or for shut down of the SFP-2, which is an advantage for application in residential PEMFC co-generations systems.

  2. Validation of spectral gas radiation models under oxyfuel conditions. Part A: Gas cell experiments

    DEFF Research Database (Denmark)

    Becher, Valentin; Clausen, Sønnik; Fateev, Alexander;

    2011-01-01

    AbstractCombustion of hydrocarbon fuels with pure oxygen results in a different flue gas composition as combustion with air. Standard CFD spectral gas radiation models for air combustion are out of their validity range. The series of three articles provides a common spectral basis for the validat......AbstractCombustion of hydrocarbon fuels with pure oxygen results in a different flue gas composition as combustion with air. Standard CFD spectral gas radiation models for air combustion are out of their validity range. The series of three articles provides a common spectral basis...

  3. Hot-gas filter manufacturing assessments: Volume 5. Final report, April 15, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Boss, D.E.

    1997-12-31

    The development of advanced filtration media for advanced fossil-fueled power generating systems is a critical step in meeting the performance and emissions requirements for these systems. While porous metal and ceramic candle-filters have been available for some time, the next generation of filters will include ceramic-matrix composites (CMCs), intermetallic alloys, and alternate filter geometries. The goal of this effort was to perform a cursory review of the manufacturing processes used by 5 companies developing advanced filters from the perspective of process repeatability and the ability for their processes to be scale-up to production volumes. It was found that all of the filter manufacturers had a solid understanding of the product development path. Given that these filters are largely developmental, significant additional work is necessary to understand the process-performance relationships and projecting manufacturing costs. While each organization had specific needs, some common among all of the filter manufacturers were access to performance testing of the filters to aide process/product development, a better understanding of the stresses the filters will see in service for use in structural design of the components, and a strong process sensitivity study to allow optimization of processing.

  4. The NATA code: Theory and analysis, volume 1. [user manuals (computer programming) - gas dynamics, wind tunnels

    Science.gov (United States)

    Bade, W. L.; Yos, J. M.

    1975-01-01

    A computer program for calculating quasi-one-dimensional gas flow in axisymmetric and two-dimensional nozzles and rectangular channels is presented. Flow is assumed to start from a state of thermochemical equilibrium at a high temperature in an upstream reservoir. The program provides solutions based on frozen chemistry, chemical equilibrium, and nonequilibrium flow with finite reaction rates. Electronic nonequilibrium effects can be included using a two-temperature model. An approximate laminar boundary layer calculation is given for the shear and heat flux on the nozzle wall. Boundary layer displacement effects on the inviscid flow are considered also. Chemical equilibrium and transport property calculations are provided by subroutines. The code contains precoded thermochemical, chemical kinetic, and transport cross section data for high-temperature air, CO2-N2-Ar mixtures, helium, and argon. It provides calculations of the stagnation conditions on axisymmetric or two-dimensional models, and of the conditions on the flat surface of a blunt wedge. The primary purpose of the code is to describe the flow conditions and test conditions in electric arc heated wind tunnels.

  5. The volume of Purkinje cells decreases in the cerebellum of acrylamide-intoxicated rats, but no cells are lost

    DEFF Research Database (Denmark)

    Larsen, Jytte Overgaard; Tandrup, T; Braendgaard, H

    1994-01-01

    The effects of acrylamide intoxication on the numbers of granule and Purkinje cells and the volume of Purkinje cell perikarya have been evaluated with stereological methods. The analysis was carried out in the cerebella of rats that had received a dose of 33.3 mg/kg acrylamide, twice a week, for 7...

  6. A study of gas bubbles in liquid mercury in a vertical Hele-Shaw cell

    Science.gov (United States)

    Klaasen, B.; Verhaeghe, F.; Blanpain, B.; Fransaer, J.

    2014-01-01

    High-quality observations of mesoscopic gas bubbles in liquid metal are vital for a further development of pyrometallurgical gas injection reactors. However, the opacity of metals enforces the use of indirect imaging techniques with limited temporal or spatial resolution. In addition, accurate interface tracking requires tomography which further complicates the design of a high-temperature experimental setup. In this paper, an alternative approach is suggested that circumvents these two main restrictions. By injecting gas in a thin layer of liquid metal entrapped between two flat and closely spaced plates, bubbles in a Hele-Shaw flow regime are generated. The resulting quasi-2D multiphase flow phenomena can be fully captured from a single point of view and, when using a non-wetted transparent plate material, the bubbles can be observed directly. The feasibility of this approach is demonstrated by observations on buoyancy-driven nitrogen bubbles in liquid mercury in a vertical Hele-Shaw cell. By using a moving high-speed camera to make continuous close up recordings of individual bubbles, the position and geometry of these bubbles are quantified with a high resolution along their entire path. After a thorough evaluation of the experimental accuracy, this information is used for a detailed analysis of the bubble expansion along the path. While the observed bubble growth is mainly caused by the hydrostatic pressure gradient, a careful assessment of the volume variations for smaller bubbles shows that an accurate bubble description should account for significant dynamic pressure variations that seem to be largely regime dependent.

  7. Mean reticulocyte volume enhances the utility of red cell mean sphered cell volume in differentiating peripheral blood spherocytes of hereditary spherocytosis from other causes

    Directory of Open Access Journals (Sweden)

    Sukesh C Nair

    2015-01-01

    Full Text Available Context: Mean sphered cell volume (MSCV and mean reticulocyte volume (MRV are additional reticulocyte parameters generated while processing the blood samples on Beckman coulter LH 755 in the reticulocyte mode using the volume, conductivity and scatter technology. It has been observed that the difference between mean corpuscular volume (MCV and MSCV is higher in the cases of hereditary spherocytosis (HS and this difference is increasingly being utilized as a screening tool for spherocytes. In addition now there have been new observations that reticulocyte volume in cases of HS is less as compared to normal reticulocyte. Aims: Our aim was to test the usefulness of reticulocyte parameters like MSCV and MRV in distinguishing cases of HS and autoimmune hemolytic anemia (AIHA. Materials and Methods: This is a retrospective and partly prospective study where peripheral blood ethylenediaminetetraacetic acid samples from cases of HS (n = 57 and AIHA (n = 29 were processed on LH 755 in both the differential and the reticulocyte mode. The data generated were analyzed and compared with data from normal healthy donors (n = 46. Results: Using an algorithm of MCV - MSCV >10 and MRV - MSCV <25, a sensitivity of 84.2% and specificity of 94.7% was observed in cases of HS. Conclusions: With the reticulocyte analysis, we may now have a simple and cheap additional tool for screening of HS.

  8. RESULTS FROM EPA FUNDED RESEARCH PROGRAMS ON THE IMPORTANCE OF PURGE VOLUME, SAMPLE VOLUME, SAMPLE FLOW RATE AND TEMPORAL VARIATIONS ON SOIL GAS CONCENTRATIONS

    Science.gov (United States)

    Two research studies funded and overseen by EPA have been conducted since October 2006 on soil gas sampling methods and variations in shallow soil gas concentrations with the purpose of improving our understanding of soil gas methods and data for vapor intrusion applications. Al...

  9. Purinergic signalling - a possible mechanism for KCNQ1 channel response to cell volume challenges

    DEFF Research Database (Denmark)

    Bomholtz, Sofia Hammami; Willumsen, Niels J.; Meinild, A.-K.

    2013-01-01

    to ion channel stimulation and cell volume back-regulation. Our aim was to investigate whether volume sensitivity of the voltage-gated K(+) channel, KCNQ1, is dependent on ATP release and regulation by purinergic signalling. METHODS: We used Xenopus oocytes heterologously expressing human KCNQ1, KCNE1......, water channels (AQP1) and P2Y2 receptors. ATP release was monitored by a luciferin-luciferase assay and ion channel conductance was recorded by two-electrode voltage clamp. RESULTS: The luminescence assay showed that oocytes released ATP in response to mechanical, hypoosmotic stimuli and hyperosmotic...... to mechanical stimuli and cell volume changes. Purinergic P2 and P1 receptors confer some of the KCNQ1 channel volume sensitivity, although endogenous adenosine receptors and expressed P2Y2 receptors do so in the negative direction....

  10. Influence of skeletal muscle satellite cells implanted into infarcted myocardium on remnant myocyte volumes

    Institute of Scientific and Technical Information of China (English)

    钟竑; 朱洪生; 卫洪超; 张臻

    2003-01-01

    Objective To study the effects of skeletal muscle satellite cells implanted into infarcted myocardium on the volume of remnant myocytes.Methods Thirty-six adult mongrel canines were divided randomly into implantation group and control group. In the implantation group, skeletal muscle satellite cells taken from the gluteus maximus muscles of the dogs were cultured, proliferated and labeled with 4', 6-diamidino-2-phenylindone (DAPI) in vitro. In both groups, a model of acute myocardial infarction was established in every dog. In the implantation group, each dog was injected with M199 solution containing autologous skeletal muscle satellite cells. The dogs in the control group received M199 solution without skeletal muscle satellite cells. The dogs of both groups were killed 2, 4 and 8 weeks after implantation (six dogs in a separate group each time). Both infarcted myocardium and normal myocytes distal from the infracted regions isolated were observed under optical and fluorescent microscope. Their volumes were determined using a confocal microscopy image analysis system and analyzed using SAS. A P<0.05 was considered significant.Results A portion of the implanted cells differentiated into muscle fiber with striations and were connected with intercalated discs. Cross-sectional area and cell volume were increased in normal myocardium. Hypertrophy of remnant myocytes in the infarcted site after skeletal muscle cell implantation was much more evident than in the control group. Cross-sectional area, cell area and cell volume differed significantly from those of the control group (P< 0.05). Hypertrophy of the cells occurred predominantly in terms of width and thickness, whereas cell length remained unchanged. Conclusion Skeletal muscle satellite cells implanted into infarct myocardium, could induce the hypertrophy of remnant myocyte cells in the infarcted site and could also aid in the recovery of the contractile force of the infarcted myocardium.

  11. Fluorescence exclusion: A simple versatile technique to calculate cell volumes and local heights (Conference Presentation)

    Science.gov (United States)

    Thouvenin, Olivier; Fink, Mathias; Boccara, A. Claude

    2017-02-01

    Understanding volume regulation during mitosis is technically challenging. Indeed, a very sensitive non invasive imaging over time scales ranging from seconds to hours and over large fields is required. Therefore, Quantitative Phase Imaging (QPI) would be a perfect tool for such a project. However, because of asymmetric protein segregation during mitosis, an efficient separation of the refractive index and the height in the phase signal is required. Even though many strategies to make such a separation have been developed, they usually are difficult to implement, have poor sensitivity, or cannot be performed in living cells, or in a single shot. In this paper, we will discuss the use of a new technique called fluorescence exclusion to perform volume measurements. By coupling such technique with a simultaneous phase measurement, we were also able to recover the refractive index inside the cells. Fluorescence exclusion is a versatile and powerful technique that allows the volume measurement of many types of cells. A fluorescent dye, which cannot penetrate inside the cells, is mixed with the external medium in a confined environment. Therefore, the fluorescent signal depends on the inverse of the object's height. We could demonstrate both experimentally and theoretically that fluorescence exclusion can accurately measure cell volumes, even for cells much higher than the depth of focus of the objective. A local accurate height and RI measurement can also be obtained for smaller cells. We will also discuss the way to optimize the confinement of the observation chamber, either mechanically or optically.

  12. Calcium signaling and cell volume regulation are altered in Sjögren's Syndrome.

    Science.gov (United States)

    Enger, Tone Berge; Aure, Marit Høyberg; Jensen, Janicke Liaaen; Galtung, Hilde Kanli

    2014-10-01

    Sjögren's Syndrome (SS) is a chronic autoimmune disease, leading to deficient secretion from salivary and lacrimal glands. Saliva production is normally increased by cholinergic innervation, giving rise to intracellular calcium signaling and water transport through water channels (aquaporins, AQPs). The aim of this study was to investigate possible pathophysiological changes in cell volume regulation, AQP expression and localization, and intracellular calcium signaling in glandular cells from SS patients compared to controls. A total of 35 SS patients and 41 non-SS controls were included. Real time qPCR was combined with immunohistochemistry to analyze the mRNA expression and cellular distribution of AQP1, 3 and 5. Cell volume regulation and intracellular calcium signaling were examined in fresh acinar cells. We show for the first time a reduced mRNA expression of AQP1 and 5 in SS compared to controls, accompanied by a decrease in staining intensity of AQP1, 3 and 5 in areas adjacent to local lymphocytic infiltration. Furthermore, we observed that the SS cells' capacity for volume regulation was abnormal. Similarly, the calcium response after parasympathetic agonist (carbachol) stimulation was markedly decreased in SS cells. It is concluded that mRNA expression of AQP1 and 5, protein distribution of AQP1, 3 and 5, glandular cell volume regulation and intracellular calcium signaling are all altered in SS, pointing to possible pathophysiological mechanisms in SS.

  13. Changes in subcutaneous fat cell volume and insulin sensitivity after weight loss.

    Science.gov (United States)

    Andersson, Daniel P; Eriksson Hogling, Daniel; Thorell, Anders; Toft, Eva; Qvisth, Veronica; Näslund, Erik; Thörne, Anders; Wirén, Mikael; Löfgren, Patrik; Hoffstedt, Johan; Dahlman, Ingrid; Mejhert, Niklas; Rydén, Mikael; Arner, Erik; Arner, Peter

    2014-07-01

    Large subcutaneous fat cells associate with insulin resistance and high risk of developing type 2 diabetes. We investigated if changes in fat cell volume and fat mass correlate with improvements in the metabolic risk profile after bariatric surgery in obese patients. Fat cell volume and number were measured in abdominal subcutaneous adipose tissue in 62 obese women before and 2 years after Roux-en-Y gastric bypass (RYGB). Regional body fat mass by dual-energy X-ray absorptiometry; insulin sensitivity by hyperinsulinemic-euglycemic clamp; and plasma glucose, insulin, and lipid profile were assessed. RYGB decreased body weight by 33%, which was accompanied by decreased adipocyte volume but not number. Fat mass in the measured regions decreased and all metabolic parameters were improved after RYGB (P fat cell size correlated strongly with improved insulin sensitivity (P = 0.0057), regional changes in fat mass did not, except for a weak correlation between changes in visceral fat mass and insulin sensitivity and triglycerides. The curve-linear relationship between fat cell size and fat mass was altered after weight loss (P = 0.03). After bariatric surgery in obese women, a reduction in subcutaneous fat cell volume associates more strongly with improvement of insulin sensitivity than fat mass reduction per se. An altered relationship between adipocyte size and fat mass may be important for improving insulin sensitivity after weight loss. Fat cell size reduction could constitute a target to improve insulin sensitivity. © 2014 by the American Diabetes Association.

  14. Evaluation of Public Service Electric & Gas Company`s standard offer program, Volume I

    Energy Technology Data Exchange (ETDEWEB)

    Goldman, C.A.; Kito, M.S.; Moezzi, M.M.

    1995-07-01

    In May 1993, Public Service Electric and Gas (PSE&G), the largest investor-owned utility in New Jersey, initiated the Standard Offer program, an innovative approach to acquiring demand-side management (DSM) resources. In this program, PSE&G offers longterm contracts with standard terms and conditions to project sponsors, either customers or third-party energy service companies (ESCOs), on a first-come, first-serve basis to fill a resource block. The design includes posted, time-differentiated prices which are paid for energy savings that will be verified over the contract term (5, 10, or 15 years) based on a statewide measurement and verification (M&V) protocol. The design of the Standard Offer differs significantly from DSM bidding programs in several respects. The eligibility requirements and posted prices allow ESCOs and other energy service providers to market and develop projects among customers with few constraints on acceptable end use efficiency technologies. In contrast, in DSM bidding, ESCOs typically submit bids without final commitments from customers and the utility selects a limited number of winning bidders who often agree to deliver a pre-specified mix of savings from various end uses in targeted markets. The major objectives of the LBNL evaluation were to assess market response and customer satisfaction; analyze program costs and cost-effectiveness; review and evaluate the utility`s administration and delivery of the program; examine the role of PSE&G`s energy services subsidiary (PSCRC) in the program and the effect of its involvement on the development of the energy services industry in New Jersey; and discuss the potential applicability of the Standard Offer concept given current trends in the electricity industry (i.e., increasing competition and the prospect of industry restructuring).

  15. Evaluation of Public Service Electric & Gas Company`s standard offer program, Volume I

    Energy Technology Data Exchange (ETDEWEB)

    Goldman, C.A.; Kito, M.S.; Moezzi, M.M.

    1995-07-01

    In May 1993, Public Service Electric and Gas (PSE&G), the largest investor-owned utility in New Jersey, initiated the Standard Offer program, an innovative approach to acquiring demand-side management (DSM) resources. In this program, PSE&G offers longterm contracts with standard terms and conditions to project sponsors, either customers or third-party energy service companies (ESCOs), on a first-come, first-serve basis to fill a resource block. The design includes posted, time-differentiated prices which are paid for energy savings that will be verified over the contract term (5, 10, or 15 years) based on a statewide measurement and verification (M&V) protocol. The design of the Standard Offer differs significantly from DSM bidding programs in several respects. The eligibility requirements and posted prices allow ESCOs and other energy service providers to market and develop projects among customers with few constraints on acceptable end use efficiency technologies. In contrast, in DSM bidding, ESCOs typically submit bids without final commitments from customers and the utility selects a limited number of winning bidders who often agree to deliver a pre-specified mix of savings from various end uses in targeted markets. The major objectives of the LBNL evaluation were to assess market response and customer satisfaction; analyze program costs and cost-effectiveness; review and evaluate the utility`s administration and delivery of the program; examine the role of PSE&G`s energy services subsidiary (PSCRC) in the program and the effect of its involvement on the development of the energy services industry in New Jersey; and discuss the potential applicability of the Standard Offer concept given current trends in the electricity industry (i.e., increasing competition and the prospect of industry restructuring).

  16. Research and development of a high efficiency gas-fired water heater. Volume 2. Task reports

    Energy Technology Data Exchange (ETDEWEB)

    Vasilakis, A.D.; Pearson, J.F.; Gerstmann, J.

    1980-01-01

    Design and development of a cost-effective high efficiency gas-fired water heater to attain a service efficiency of 70% (including the effect of exfiltration) and a service efficiency of 78% (excluding exfiltration) for a 75 GPD draw at a 90/sup 0/F temperature rise, with a stored water to conditioned air temperature difference of 80/sup 0/F, are described in detail. Based on concept evaluation, a non-powered natural draft water heater was chosen as the most cost-effective design to develop. The projected installed cost is $374 compared to $200 for a conventional unit. When the project water heater is compared to a conventional unit, it has a payback of 3.7 years and life cycle savings of $350 to the consumer. A prototype water heater was designed, constructed, and tested. When operated with sealed combustion, the unit has a service efficiency of 66.4% (including the effect of exfiltration) below a burner input of 32,000 Btu/h. In the open combustion configuration, the unit operated at a measured efficiency of 66.4% Btu/h (excluding exfiltration). This compares with a service efficiency of 51.3% for a conventional water heater and 61% for a conventional high efficiency unit capable of meeting ASHRAE 90-75. Operational tests showed the unit performed well with no evidence of stacking or hot spots. It met or exceeded all capacity or usage tests specified in the program test plan and met all emission goals. Future work will concentrate on designing, building, and testing pre-production units. It is anticipated that both sealed combustion and open draft models will be pursued.

  17. Evaluation of Gas-Cooled Pressurized Phosphoric Acid Fuel Cells for Electric Utility Power Generation

    Science.gov (United States)

    Faroque, M.

    1983-01-01

    Gas cooling is a more reliable, less expensive and a more simple alternative to conventional liquid cooling for heat removal from the phosphoric acid fuel cell (PAFC). The feasibility of gas-cooling was already demonstrated in atmospheric pressure stacks. Theoretical and experimental investigations of gas-cooling for pressurized PAFC are presented. Two approaches to gas cooling, Distributed Gas-Cooling (DIGAS) and Separated Gas-Cooling (SGC) were considered, and a theoretical comparison on the basis of cell performance indicated SGC to be superior to DIGAS. The feasibility of SGC was experimentally demonstrated by operating a 45-cell stack for 700 hours at pressure, and determining thermal response and the effect of other related parameters.

  18. Evaluation of gas cooling for pressurized phosphoric acid fuel cell stacks

    Science.gov (United States)

    Farooque, M.; Skok, A. J.; Maru, H. C.; Kothmann, R. E.; Harry, R. W.

    1983-01-01

    Gas cooling is a more reliable, less expensive and a more simple alternative to conventional liquid cooling for heat removal from the phosphoric acid fuel cell (PAFC). The feasibility of gas cooling has already been demonstrated in atmospheric pressure stacks. This paper presents theoretical and experimental investigation of gas cooling for pressurized PAFC. Two approaches to gas cooling, Distributed Gas Cooling (DIGAS) and Separated Gas Cooling (SGC) were considered, and a theoretical comparison on the basis of cell performance indicated SGC to be superior to DIGAS. The feasibility of SGC was experimentally demonstrated by operating a 45-cell stack for 700 hours at pressure, and determining thermal response and the effect of other related parameters.

  19. ARMA Model of Natural Gas Sales Volume of Shanghai%上海市天然气销售量的ARMA模型

    Institute of Scientific and Technical Information of China (English)

    任桢

    2011-01-01

    The article establishes the ARMA model by the application of economics' software-'Eviews' to analyze the natural gas sales volume monthly of Shanghai.%文章运用计量经济学软件(Eviews)对上海市天然气月销售量进行分析建立合适的ARMA模型。

  20. Estimation of current density distribution of PAFC by analysis of cell exhaust gas

    Energy Technology Data Exchange (ETDEWEB)

    Kato, S.; Seya, A. [Fuji Electric Co., Ltd., Ichihara-shi (Japan); Asano, A. [Fuji Electric Corporate, Ltd., Yokosuka-shi (Japan)

    1996-12-31

    To estimate distributions of Current densities, voltages, gas concentrations, etc., in phosphoric acid fuel cell (PAFC) stacks, is very important for getting fuel cells with higher quality. In this work, we leave developed a numerical simulation tool to map out the distribution in a PAFC stack. And especially to Study Current density distribution in the reaction area of the cell, we analyzed gas composition in several positions inside a gas outlet manifold of the PAFC stack. Comparing these measured data with calculated data, the current density distribution in a cell plane calculated by the simulation, was certified.

  1. Investigation of gas generation in regenerative fuel cells by low-energy X-rays

    Science.gov (United States)

    Selamet, Omer Faruk; Deevanhxay, Phengxay; Tsushima, Shohji; Hirai, Shuichiro

    2015-11-01

    Gas generation and discharge behaviors in an operating regenerative fuel cell (RFC) are investigated using low-energy X-ray radiography. In situ visualization at high spatial and temporal resolution reveal dynamic and inhomogeneous behaviors of the gas generation in the membrane electrode assembly (MEA) in the RFC. Temporal and spatial variation of the gas thickness in the MEA is quantitatively discussed and shows an intermittent and periodic discharge processes of the gas generated by electrolysis, suggesting that the reaction sites in the catalyst layer and the discharging path of gas bubbles are well established in the MEA for the electrolysis. Larger gas accumulation and discharge in the gas diffusion layer (GDL) under the ribs are identified in comparison with those under the channels, which is attributed to the relatively longer path for accumulated gas under the ribs to be discharged into the flow channels.

  2. A novel geotechnical/geostatistical approach for exploration and production of natural gas from multiple geologic strata, Phase 1. Volume 1, Overview

    Energy Technology Data Exchange (ETDEWEB)

    Overbey, W.K. Jr.; Reeves, T.K.; Salamy, S.P.; Locke, C.D.; Johnson, H.R.; Brunk, R.; Hawkins, L. [BDM Engineering Services Co., Morgantown, WV (United States)

    1991-05-01

    This research program has been designed to develop and verify a unique geostatistical approach for finding natural gas resources. The research has been conducted by Beckley College, Inc. (Beckley) and BDM Engineering Services Company (BDMESC) under contract to the US Department of Energy (DOE), Morgantown Energy Technology Center. Phase 1 of the project consisted of compiling and analyzing relevant geological and gas production information in selected areas of Raleigh County, West Virginia, ultimately narrowed to the Eccles, West Virginia, 7 {1/2} minute Quadrangle. The Phase 1 analysis identified key parameters contributing to the accumulation and production of natural gas in Raleigh County, developed analog models relating geological factors to gas production, and identified specific sites to test and verify the analysis methodologies by drilling. Based on the Phase 1 analysis, five sites have been identified with high potential for economic gas production. Phase 2 will consist of drilling, completing, and producing one or more wells at the sites identified in the Phase 1 analyses. The initial well is schedules to the drilled in April 1991. This report summarizes the results of the Phase 1 investigations. For clarity, the report has been prepared in two volumes. Volume 1 presents the Phase 1 overview; Volume 2 contains the detailed geological and production information collected and analyzed for this study.

  3. Cell Volume Regulation and Signaling in 3T3-L1 Pre-adipocytes and Adipocytes

    DEFF Research Database (Denmark)

    Eduardsen, Kathrine; Larsen, Susanne; Novak, Ivana

    2011-01-01

    Caveolae have been implicated in sensing of cell volume perturbations, yet evidence is still limited and findings contradictory. Here, we investigated the possible role of caveolae in cell volume regulation and volume sensitive signaling in an adipocyte system with high (3T3-L1 adipocytes......) and osmotic cell shrinkage (RVI), accompanied by increased swelling-activated taurine efflux. However, caveolin-1 distribution was not detectably altered after osmotic swelling or shrinkage, and caveolae integrity, as studied by cholesterol depletion or expression of dominant negative Cav-1, was not required...... no detectable effect on InsR, yet increased ERK1/2 phosphorylation. In conclusion, differentiated 3T3-L1 adipocytes exhibit greatly accelerated RVD and RVI responses and increased swelling-activated taurine efflux compared to pre-adipocytes. Furthermore, in pre-adipocytes, Cav-1/caveolae integrity...

  4. Determination of micro-litre volumes with high accuracy for flow cytometric blood cell counting

    Science.gov (United States)

    Reitz, S.; Kummrow, A.; Kammel, M.; Neukammer, J.

    2010-07-01

    We have gravimetrically calibrated the volumes dispensed by 1 mL syringes in the range between 1 µL and 100 µL using ultra-pure water. Protocols are based on series of consecutive difference measurements of masses in order to precisely compensate for evaporation, being the most important disturbing quantity. We determined expanded uncertainties of volume measurements for glass syringes of typically 0.2% (expansion factor 2) when dispensing volumes of 10 µL. For polypropylene syringes, selected with respect to the manufacturer, expanded uncertainties of 0.25% (expansion factor 2) were observed. Calibrated syringes were applied for measuring concentrations of blood cells in a flow cytometer demonstrating the capability to determine reference measurement values. Since the direct interaction of blood cells and syringe walls may lead to cell adhesion, glass syringes as well as (disposable) polypropylene syringes were calibrated.

  5. Red cell volume with changes in plasma osmolarity during maximal exercise.

    Science.gov (United States)

    Van Beaumont, W.

    1973-01-01

    The volume of the red cell in vivo was measured during acute changes in plasma osmolarity evoked through short (6 to 8 min) maximal exercise in six male volunteer subjects. Simultaneous measurements of mean corpuscular red cell volume (MCV), hematocrit, blood hemoglobin, mean corpuscular hemoglobin concentration (MCHC), and plasma osmolarity showed that there was no change in the MCV or MCHC with a concomitant rise of nearly 6% in plasma osmolarity. Apparently, in vivo, the volume of the red cell in exercising healthy human subjects does not change measurably, in spite of significant changes in osmotic pressure of the surrounding medium. Consequently, it is not justified to correct postexercise hematocrit measurements for changes in plasma osmolarity.

  6. Red cell volume with changes in plasma osmolarity during maximal exercise.

    Science.gov (United States)

    Van Beaumont, W.

    1973-01-01

    The volume of the red cell in vivo was measured during acute changes in plasma osmolarity evoked through short (6 to 8 min) maximal exercise in six male volunteer subjects. Simultaneous measurements of mean corpuscular red cell volume (MCV), hematocrit, blood hemoglobin, mean corpuscular hemoglobin concentration (MCHC), and plasma osmolarity showed that there was no change in the MCV or MCHC with a concomitant rise of nearly 6% in plasma osmolarity. Apparently, in vivo, the volume of the red cell in exercising healthy human subjects does not change measurably, in spite of significant changes in osmotic pressure of the surrounding medium. Consequently, it is not justified to correct postexercise hematocrit measurements for changes in plasma osmolarity.

  7. Power and temperature control of fluctuating biomass gas fueled solid oxide fuel cell and micro gas turbine hybrid system

    Science.gov (United States)

    Kaneko, T.; Brouwer, J.; Samuelsen, G. S.

    This paper addresses how the power and temperature are controlled in a biomass gas fueled solid oxide fuel cell (SOFC) and micro gas turbine (MGT) hybrid system. A SOFC and MGT dynamic model are developed and used to simulate the hybrid system performance operating on biomass gas. The transient behavior of both the SOFC and MGT are discussed in detail. An unstable power output is observed when the system is fed biomass gas. This instability is due to the fluctuation of gas composition in the fuel. A specially designed fuel controller succeeded not only in allowing the hybrid system to follow a step change of power demand from 32 to 35 kW, but also stably maintained the system power output at 35 kW. In addition to power control, fuel cell temperature is controlled by introduction and use of a bypass valve around the recuperator. By releasing excess heat to the exhaust, the bypass valve provided the control means to avoid the self-exciting behavior of system temperature and stabilized the temperature of SOFC at 850 °C.

  8. CAD/CAM-designed 3D-printed electroanalytical cell for the evaluation of nanostructured gas-diffusion electrodes

    Science.gov (United States)

    Chervin, Christopher N.; Parker, Joseph F.; Nelson, Eric S.; Rolison, Debra R.; Long, Jeffrey W.

    2016-04-01

    The ability to effectively screen and validate gas-diffusion electrodes is critical to the development of next-generation metal-air batteries and regenerative fuel cells. The limiting electrode in a classic two-terminal device such as a battery or fuel cell is difficult to discern without an internal reference electrode, but the flooded electrolyte characteristic of three-electrode electroanalytical cells negates the prime function of an air electrode—a void volume freely accessible to gases. The nanostructured catalysts that drive the energy-conversion reactions (e.g., oxygen reduction and evolution in the air electrode of metal-air batteries) are best evaluated in the electrode structure as-used in the practical device. We have designed, 3D-printed, and characterized an air-breathing, thermodynamically referenced electroanalytical cell that allows us to mimic the Janus arrangement of the gas-diffusion electrode in a metal-air cell: one face freely exposed to gases, the other wetted by electrolyte.

  9. Peripheral Lymphoid Volume Expansion and Maintenance Are Controlled by Gut Microbiota via RALDH+ Dendritic Cells.

    Science.gov (United States)

    Zhang, Zongde; Li, Jianjian; Zheng, Wencheng; Zhao, Guang; Zhang, Hong; Wang, Xiaofei; Guo, Yaqian; Qin, Chuan; Shi, Yan

    2016-02-16

    Lymphocyte homing to draining lymph nodes is critical for the initiation of immune responses. Secondary lymphoid organs of germ-free mice are underdeveloped. How gut commensal microbes remotely regulate cellularity and volume of secondary lymphoid organs remains unknown. We report here that, driven by commensal fungi, a wave of CD45(+)CD103(+)RALDH(+) cells migrates to the peripheral lymph nodes after birth. The arrival of these cells introduces high amounts of retinoic acid, mediates the neonatal to adult addressin switch on endothelial cells, and directs the homing of lymphocytes to both gut-associated lymphoid tissues and peripheral lymph nodes. In adult mice, a small number of these RALDH(+) cells might serve to maintain the volume of secondary lymphoid organs. Homing deficiency of these cells was associated with lymph node attrition in vitamin-A-deficient mice, suggesting a perpetual dependence on retinoic acid signaling for structural and functional maintenance of peripheral immune organs.

  10. Chronic effects of ultraviolet-B radiation on growth and cell volume of Phaeodactylum tricornutum (Bacillariophyceae)

    Energy Technology Data Exchange (ETDEWEB)

    Behrenfeld, M.J. (AScI Corp., Newport, OR (United States)); Hardy, J.T. (Western Washington Univ., Bellingham (United States)); Lee, H. II (Environmental Protection Agency, Newport, OR (United States))

    1992-12-01

    Cultures of the temperate estuarine diatom, Phaeodactylum tricornutum Bohlin (NEPCC Clone 31), were grown under ambient intensities of ultraviolet-A radiation (UVAR), photosynthetically active radiation (PAR), and various intensities of ultraviolet-B radiation (UVBR; 290-320 nm). Growth rates and cell volumes were monitored for 36 d. UVBR decreased growth rates and increased cell volumes. Sensitivity of growth to UVBR increased with time. Growth rates of P. tricornutum decreased with increasing ratios of UVBR:UVAR + PAR. 25 refs., 4 figs., 1 tab.

  11. Foam Based Gas Diffusion Electrodes for Reversible Alkaline Electrolysis Cells

    DEFF Research Database (Denmark)

    Allebrod, Frank; Chatzichristodoulou, Christodoulos; Mogensen, Mogens Bjerg

    2014-01-01

    to the gas diffusion electrodes. A dispersion with PTFE particles of a particle size of about 1 µm in combination with electro-catalysts, such as silver nanotubes, was used to coat the gas diffusion electrodes. Impedance spectroscopy and cyclic voltammetry measurements were performed to determine...

  12. Cell type-specific adaptation of cellular and nuclear volume in micro-engineered 3D environments.

    Science.gov (United States)

    Greiner, Alexandra M; Klein, Franziska; Gudzenko, Tetyana; Richter, Benjamin; Striebel, Thomas; Wundari, Bayu G; Autenrieth, Tatjana J; Wegener, Martin; Franz, Clemens M; Bastmeyer, Martin

    2015-11-01

    Bio-functionalized three-dimensional (3D) structures fabricated by direct laser writing (DLW) are structurally and mechanically well-defined and ideal for systematically investigating the influence of three-dimensionality and substrate stiffness on cell behavior. Here, we show that different fibroblast-like and epithelial cell lines maintain normal proliferation rates and form functional cell-matrix contacts in DLW-fabricated 3D scaffolds of different mechanics and geometry. Furthermore, the molecular composition of cell-matrix contacts forming in these 3D micro-environments and under conventional 2D culture conditions is identical, based on the analysis of several marker proteins (paxillin, phospho-paxillin, phospho-focal adhesion kinase, vinculin, β1-integrin). However, fibroblast-like and epithelial cells differ markedly in the way they adapt their total cell and nuclear volumes in 3D environments. While fibroblast-like cell lines display significantly increased cell and nuclear volumes in 3D substrates compared to 2D substrates, epithelial cells retain similar cell and nuclear volumes in 2D and 3D environments. Despite differential cell volume regulation between fibroblasts and epithelial cells in 3D environments, the nucleus-to-cell (N/C) volume ratios remain constant for all cell types and culture conditions. Thus, changes in cell and nuclear volume during the transition from 2D to 3D environments are strongly cell type-dependent, but independent of scaffold stiffness, while cells maintain the N/C ratio regardless of culture conditions.

  13. Reactant gas transport and cell performance of proton exchange membrane fuel cells with tapered flow field design

    Energy Technology Data Exchange (ETDEWEB)

    Liu, H.C.; Yan, W.M. [Department of Mechatronic Engineering, Huafan University, Shih-Ting, Taipei 223, Taiwan (ROC); Soong, C.Y. [Department of Aerospace and Systems Engineering, Feng Chia University, Seatwen, Taichung 407, Taiwan (ROC); Chen, Falin [Institute of Applied Mechanics, National Taiwan University, Taipei 106, Taiwan (ROC); Chu, H.S. [Department of Mechanical Engineering, National Chiao-Tung University, Hsinchu 300, Taiwan (ROC)

    2006-07-14

    The objective of this work is to examine the reactant gas transport and the cell performance of a proton exchange membrane fuel cell (PEMFC) with a tapered flow channel design. It is expected that, with the reduction in the channel depth along the streamwise direction, the reactant fuel gas in the tapered channel can be accelerated as well as forced into the gas diffuser layer to enhance the electrochemical reaction and thus augment the cell performance. The effects of liquid water formation on the reactant gas transport are taken into account in the present study. Numerical predictions show that the cell performance can be enhanced with the fuel channel tapered, and the enhancement is more noticeable at a lower voltage. The results also reveal that the liquid water effect in general influences the cell performance and the effect becomes significant at lower voltages. (author)

  14. Reactant gas transport and cell performance of proton exchange membrane fuel cells with tapered flow field design

    Science.gov (United States)

    Liu, H. C.; Yan, W. M.; Soong, C. Y.; Chen, Falin; Chu, H. S.

    The objective of this work is to examine the reactant gas transport and the cell performance of a proton exchange membrane fuel cell (PEMFC) with a tapered flow channel design. It is expected that, with the reduction in the channel depth along the streamwise direction, the reactant fuel gas in the tapered channel can be accelerated as well as forced into the gas diffuser layer to enhance the electrochemical reaction and thus augment the cell performance. The effects of liquid water formation on the reactant gas transport are taken into account in the present study. Numerical predictions show that the cell performance can be enhanced with the fuel channel tapered, and the enhancement is more noticeable at a lower voltage. The results also reveal that the liquid water effect in general influences the cell performance and the effect becomes significant at lower voltages.

  15. Preliminary performance assessment for the Waste Isolation Pilot Plant, December 1992. Volume 5, Uncertainty and sensitivity analyses of gas and brine migration for undisturbed performance

    Energy Technology Data Exchange (ETDEWEB)

    1993-08-01

    Before disposing of transuranic radioactive waste in the Waste Isolation Pilot Plant (WIPP), the United States Department of Energy (DOE) must evaluate compliance with applicable long-term regulations of the United States Environmental Protection Agency (EPA). Sandia National Laboratories is conducting iterative performance assessments (PAs) of the WIPP for the DOE to provide interim guidance while preparing for a final compliance evaluation. This volume of the 1992 PA contains results of uncertainty and sensitivity analyses with respect to migration of gas and brine from the undisturbed repository. Additional information about the 1992 PA is provided in other volumes. Volume 1 contains an overview of WIPP PA and results of a preliminary comparison with 40 CFR 191, Subpart B. Volume 2 describes the technical basis for the performance assessment, including descriptions of the linked computational models used in the Monte Carlo analyses. Volume 3 contains the reference data base and values for input parameters used in consequence and probability modeling. Volume 4 contains uncertainty and sensitivity analyses with respect to the EPA`s Environmental Standards for the Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive Wastes (40 CFR 191, Subpart B). Finally, guidance derived from the entire 1992 PA is presented in Volume 6. Results of the 1992 uncertainty and sensitivity analyses indicate that, conditional on the modeling assumptions and the assigned parameter-value distributions, the most important parameters for which uncertainty has the potential to affect gas and brine migration from the undisturbed repository are: initial liquid saturation in the waste, anhydrite permeability, biodegradation-reaction stoichiometry, gas-generation rates for both corrosion and biodegradation under inundated conditions, and the permeability of the long-term shaft seal.

  16. Volume shrinkage of a metal-organic framework host induced by the dispersive attraction of guest gas molecules.

    Science.gov (United States)

    Joo, Jaeyong; Kim, Hyungjun; Han, Sang Soo

    2013-11-21

    Using a density functional theory calculation including van der Waals (vdW) corrections, we report that H2 adsorption in a cubic-crystalline microporous metal-organic framework (MOF-5) leads to volume shrinkage, which is in contrast to the intuition that gas adsorption in a confined system (e.g., pores in a material) increases the internal pressure and then leads to volumetric expansion. This extraordinary phenomenon is closely related to the vdW interactions between MOF and H2 along with the H2-H2 interaction, rather than the Madelung-type electrostatic interaction. At low temperatures, H2 molecules adsorbed in the MOF-5 form highly symmetrical interlinked nanocages that change from a cube-like shape to a sphere-like shape with H2 loading, helping to exert centrosymmetric forces and hydrostatic (volumetric) stresses from the collection of dispersive interactions. The generated internal negative stress is sufficient to overcome the stiffness of the MOF-5 which is a soft material with a low bulk modulus (15.54 GPa).

  17. Visualization of Gas-to-Liquid (GTL) Fuel Liquid Length and Soot Formation in the Constant Volume Combustion Chamber

    Science.gov (United States)

    Azimov, Ulugbek; Kim, Ki-Seong

    In this research, GTL spray combustion was visualized in an optically accessible quiescent constant-volume combustion chamber. The results were compared with the spray combustion of diesel fuel. Fast-speed photography with direct laser sheet illumination was used to determine the fuel liquid-phase length, and shadowgraph photography was used to determine the distribution of the sooting area in the fuel jet. The results showed that the fuel liquid-phase length of GTL fuel jets stabilized at about 20-22mm from the injector orifice and mainly depended on the ambient gas temperature and fuel volatility. GTL had a slightly shorter liquid length than that of the diesel fuel. This tendency was also maintained when multiple injection strategy was applied. The penetration of the tip of the liquid-phase fuel during pilot injection was a little shorter than the penetration during main injection. The liquid lengths during single and main injections were identical. In the case of soot formation, the results showed that soot formation was mainly affected by air-fuel mixing, and had very weak dependence on fuel volatility.

  18. Power law relationship between cell cycle duration and cell volume in the early embryonic development of Caenorhabditis elegans.

    Science.gov (United States)

    Arata, Yukinobu; Takagi, Hiroaki; Sako, Yasushi; Sawa, Hitoshi

    2014-01-01

    Cell size is a critical factor for cell cycle regulation. In Xenopus embryos after midblastula transition (MBT), the cell cycle duration elongates in a power law relationship with the cell radius squared. This correlation has been explained by the model that cell surface area is a candidate to determine cell cycle duration. However, it remains unknown whether this second power law is conserved in other animal embryos. Here, we found that the relationship between cell cycle duration and cell size in Caenorhabditis elegans embryos exhibited a power law distribution. Interestingly, the powers of the time-size relationship could be grouped into at least three classes: highly size-correlated, moderately size-correlated, and potentially a size-non-correlated class according to C. elegans founder cell lineages (1.2, 0.81, and power law relationship is conserved in Xenopus and C. elegans, while the absolute powers in C. elegans were different from that in Xenopus. Furthermore, we found that the volume ratio between the nucleus and cell exhibited a power law relationship in the size-correlated classes. The power of the volume relationship was closest to that of the time-size relationship in the highly size-correlated class. This correlation raised the possibility that the time-size relationship, at least in the highly size-correlated class, is explained by the volume ratio of nuclear size and cell size. Thus, our quantitative measurements shed a light on the possibility that early embryonic C. elegans cell cycle duration is coordinated with cell size as a result of geometric constraints between intracellular structures.

  19. Electroanalysis of metabolic flux from single cells in simple picoliter-volume microsystems.

    Science.gov (United States)

    Yasukawa, Tomoyuki; Glidle, Andrew; Cooper, Jonathan M; Matsue, Tomokazu

    2002-10-01

    A picoliter-volume electrochemical analytical chamber has been developed for detecting the metabolic flux resulting from the stress responses of a single plant cell. Electrochemical cells, with volumes as small as 100 pL, were fabricated by controlled electrochemical dissolution of a gold wire sealed in glass (the back-etching of the metal realizing an ultralow-volume titer chamber). In the first instance, the electrode contained within the chamber was characterized by the microinjection of standard aliquots of either ascorbic acid or hydrogen peroxide. In all cases, experimental currents obtained correlated well with theoretical calculations. Subsequently, single plant cells were micromanipulated into the chambers and were exposed to amounts of the detergent SDS (which permeabilized the cell membrane and released the intracellular contents). The flux of metabolite released from a single cell was estimated by using electrochemical-linked assays based upon the enzymes catalase, ascorbate oxidase, and horseradish peroxidase (in each case), in the presence of a mediator. In so doing, we investigated the activity of the cellular protection mechanisms through the determination of peroxides, while the individual cell was "stressed". The technique was found to provide a reliable and reproducible method for making single-cell measurements, using fabrication procedures that are both simple and do not require photolithographic methods.

  20. A Study of School Without Schools: The Columbus, Ohio Public Schools During the Natural Gas Shortage, Winter, 1977. Volume I and Volume II, Appendices.

    Science.gov (United States)

    Sanders, James R.; Stufflebeam, Daniel L.

    The energy crisis, specifically a shortage of natural gas, caused by the unusually cold winter of 1977, resulted in the Columbus, Ohio, schools being closed for a month. Schools heated with gas were closed, but students met one day a week in school buildings that used coal, oil, or electricity. The educational program continued with school…

  1. Effects of volume corrections and resonance decays on cumulants of net-charge distributions in a Monte Carlo hadron resonance gas model

    Science.gov (United States)

    Xu, Hao-jie

    2017-02-01

    The effects of volume corrections and resonance decays (the resulting correlations between positive charges and negative charges) on cumulants of net-proton distributions and net-charge distributions are investigated by using a Monte Carlo hadron resonance gas (MCHRG) model. The required volume distributions are generated by a Monte Carlo Glauber (MC-Glb) model. Except the variances of net-charge distributions, the MCHRG model with more realistic simulations of volume corrections, resonance decays and acceptance cuts can reasonably explain the data of cumulants of net-proton distributions and net-charge distributions reported by the STAR collaboration. The MCHRG calculations indicate that both the volume corrections and resonance decays make the cumulant products of net-charge distributions deviate from the Skellam expectations: the deviations of Sσ and κσ2 are dominated by the former effect while the deviations of ω are dominated by the latter one.

  2. Role of AQP2 in activation of calcium entry by hypotonicity: implications in cell volume regulation.

    Science.gov (United States)

    Galizia, L; Flamenco, M P; Rivarola, V; Capurro, C; Ford, P

    2008-03-01

    We previously reported in a rat cortical collecting duct cell line (RCCD(1)) that the presence of aquaporin 2 (AQP2) in the cell membrane is critical for the rapid activation of regulatory volume decrease mechanisms (RVD) (Ford et al. Biol Cell 97: 687-697, 2005). The aim of our present work was to investigate the signaling pathway that links AQP2 to this rapid RVD activation. Since it has been previously described that hypotonic conditions induce intracellular calcium ([Ca(2+)](i)) increases in different cell types, we tested the hypothesis that AQP2 could have a role in activation of calcium entry by hypotonicity and its implication in cell volume regulation. Using a fluorescent probe technique, we studied [Ca(2+)](i) and cell volume changes in response to a hypotonic shock in WT-RCCD(1) (not expressing aquaporins) and in AQP2-RCCD(1) (transfected with AQP2) cells. We found that after a hypotonic shock only AQP2-RCCD(1) cells exhibit a substantial increase in [Ca(2+)](i). This [Ca(2+)](i) increase is strongly dependent on extracellular Ca(2+) and is partially inhibited by thapsigargin (1 muM) indicating that the rise in [Ca(2+)](i) reflects both influx from the extracellular medium and release from intracellular stores. Exposure of AQP2-RCCD(1) cells to 100 muM gadolinium reduced the increase in [Ca(2+)](i) suggesting the involvement of a mechanosensitive calcium channel. Furthermore, exposure of cells to all of the above described conditions impaired rapid RVD. We conclude that the expression of AQP2 in the cell membrane is critical to produce the increase in [Ca(2+)](i) which is necessary to activate RVD in RCCD(1) cells.

  3. Oil & Natural Gas Technology A new approach to understanding the occurrence and volume of natural gas hydrate in the northern Gulf of Mexico using petroleum industry well logs

    Energy Technology Data Exchange (ETDEWEB)

    Cook, Ann [The Ohio State Univ., Columbus, OH (United States); Majumdar, Urmi [The Ohio State Univ., Columbus, OH (United States)

    2016-03-31

    The northern Gulf of Mexico has been the target for the petroleum industry for exploration of conventional energy resource for decades. We have used the rich existing petroleum industry well logs to find the occurrences of natural gas hydrate in the northern Gulf of Mexico. We have identified 798 wells with well log data within the gas hydrate stability zone. Out of those 798 wells, we have found evidence of gas hydrate in well logs in 124 wells (15% of wells). We have built a dataset of gas hydrate providing information such as location, interval of hydrate occurrence (if any) and the overall quality of probable gas hydrate. Our dataset provides a wide, new perspective on the overall distribution of gas hydrate in the northern Gulf of Mexico and will be the key to future gas hydrate research and prospecting in the area.

  4. Mechanical Interactions between Gas Diffusion Layers and Bipolar Plates in low Temperature Fuel Cells

    OpenAIRE

    Knöri, Torsten; Schulze, Mathias; Gülzow, Erich

    2007-01-01

    In contrast to stiff backing materials (e.g. carbon paper) softer ones like carbon cloth are compressed over the ribs of the gas distributors or impressed into the channels when the PEFC is assembled. During fuel cell optimisation the interactions between the gas diffusion layer and the flow field are frequently neglected; hence flow fields as well as gas diffusion layers are commonly optimized independently. The DLR has investigated these interactions with a two-stage approach: At firs...

  5. Comparison of temperature distributions inside a PEM fuel cell with parallel and interdigitated gas distributors

    Science.gov (United States)

    Hwang, J. J.; Liu, S. J.

    A comparison of the temperature distributions in a proton exchange membrane (PEM) fuel cell between the parallel-flow gas distributors and the interdigitated gas distributor has been discussed in detail. An electrochemical-thermal coupled numerical model in a five-layer membrane-electrode assembly (MEA) is developed. The temperatures for the reactant fuels as well as the carbon fibers in the porous electrode are predicted by using a CFD technique. The overpotential across the MEA is varied to examine its effect on the temperature distributions of the PEM fuel cell. It is found that both the fuel temperature and the carbon fiber temperature are increased with increasing the total overpotential. In addition, the fuel and carbon-fiber temperature distributions are significantly affected by the flow pattern that cast on the gas distributor. Replacing the parallel-flow gas distributor by the interdigitated gas distributor will increase the local maximum temperature inside the PEM fuel cell.

  6. Modeling Degradation in Solid Oxide Electrolysis Cells - Volume II

    Energy Technology Data Exchange (ETDEWEB)

    Manohar Motwani

    2011-09-01

    Idaho National Laboratory has an ongoing project to generate hydrogen from steam using solid oxide electrolysis cells (SOECs). To accomplish this, technical and degradation issues associated with the SOECs will need to be addressed. This report covers various approaches being pursued to model degradation issues in SOECs. An electrochemical model for degradation of SOECs is presented. The model is based on concepts in local thermodynamic equilibrium in systems otherwise in global thermodynamic non-equilibrium. It is shown that electronic conduction through the electrolyte, however small, must be taken into account for determining local oxygen chemical potential,, within the electrolyte. The within the electrolyte may lie out of bounds in relation to values at the electrodes in the electrolyzer mode. Under certain conditions, high pressures can develop in the electrolyte just near the oxygen electrode/electrolyte interface, leading to oxygen electrode delamination. These predictions are in accordance with the reported literature on the subject. Development of high pressures may be avoided by introducing some electronic conduction in the electrolyte. By combining equilibrium thermodynamics, non-equilibrium (diffusion) modeling, and first-principles, atomic scale calculations were performed to understand the degradation mechanisms and provide practical recommendations on how to inhibit and/or completely mitigate them.

  7. Advances in understanding the pathogenesis of the red cell volume disorders.

    Science.gov (United States)

    Badens, Catherine; Guizouarn, Hélène

    2016-09-01

    Genetic defects of erythrocyte transport proteins cause disorders of red blood cell volume that are characterized by abnormal permeability to the cations Na(+) and K(+) and, consequently, by changes in red cell hydration. Clinically, these disorders are associated with chronic haemolytic anaemia of variable severity and significant co-morbidities, such as iron overload. This review provides an overview of recent insights into the molecular basis of this group of rare anaemias involving cation channels and transporters dysfunction. To date, a total of 5 different membrane proteins have been reported to be responsible for volume homeostasis alteration when mutated, 3 of them leading to overhydrated cells (AE1 [also termed SLC4A1], RHAG and GLUT1 [also termed SCL2A1) and 2 others to dehydrated cells (PIEZO1 and the Gardos Channel). These findings are not only of basic scientific interest, but also of direct clinical significance for improving diagnostic procedures and identify potential approaches for novel therapeutic strategies.

  8. On-chip acidification rate measurements from single cardiac cells confined in sub-nanoliter volumes

    OpenAIRE

    Ges, Igor A.; Dzhura, Igor A.; Baudenbacher, Franz J.

    2008-01-01

    The metabolic activity of cells can be monitored by measuring the pH in the extracellular environment. Microfabrication and microfluidic technologies allow the sensor size and the extracellular volumes to be comparable to single cells. A glass substrate with thin film pH sensitive IrOx electrodes was sealed to a replica-molded polydimethylsiloxane (PDMS) microfluidic network with integrated valves. The device, termed NanoPhysiometer, allows the trapping of single cardiac myocytes and the meas...

  9. DEMONSTRATION OF FUEL CELLS TO RECOVER ENERGY FROM LANDFILL GAS: PHASE II. PRETREATMENT SYSTEM PERFORMANCE MEASUREMENT

    Science.gov (United States)

    The report describes Phase II of a demonstration of the utilization of commercial phosphoric acid fuel cells to recover energy from landfill gas. This phase consisted primarily of the construction and testing of a Gas Pretreatment Unit (GPU) whose function is to remove those impu...

  10. Acid Gas Removal by Customized Sorbents for Integrated Gasification Fuel Cell Systems

    Energy Technology Data Exchange (ETDEWEB)

    Kapfenberger, J.; Sohnemann, J.; Schleitzer, D.; Loewen, A.

    2002-09-20

    In order to reduce exergy losses, gas cleaning at high temperatures is favored in IGFC systems. As shown by thermodynamic data, separation efficiencies of common sorbents decrease with increasing temperature. Therefore, acid gas removal systems have to be developed for IGFC applications considering sorbent capacity, operation temperature, gasification feedstock composition and fuel cell threshold values.

  11. Development of coal gas production technology acceptable for fuel cells; Nenryo denchiyo sekitan gas seizo gijutsu ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, T. [Center for Coal Utilization, Japan, Tokyo (Japan); Kimura, N.; Omata, K. [Electric Power Development Co. Ltd., Tokyo (Japan)

    1996-09-01

    In utilizing coal for high-efficiency direct power generation using fuel cells, it is necessary that coal be fed into the fuel cells after having been made into ash-free gaseous fuel. Research and development works are being carried out with an objective to develop a coal gasification furnace most suitable for fuel cells and establish a system to refine coal up to the one that can be fed into fuel cells. Fiscal 1995 has conducted investigations on coal gasification technologies, air separation technologies, and gas refining technologies as the important element technologies, and a trial design on integrated coal gasification fuel cell (IGFC) systems. This paper reports from among the above items the result of the trial design on an IGFC system using molten carbonate fuel cells. The paper describes system comparison on paths of produced gases and anode waste gas, comparison on refining processes using a wet system and a dry system, and parameter studies on oxygen concentration in gasifying agents. It was made clear that the suitable furnace is an oxygen blown coal gasification furnace, and the power generation efficiency at the system terminal can be higher than 53%. 11 figs., 6 tabs.

  12. Application of Nuclear Volume Measurements to Comprehend the Cell Cycle in Root-Knot Nematode-Induced Giant Cells

    Directory of Open Access Journals (Sweden)

    José Dijair Antonino de Souza Junior

    2017-06-01

    Full Text Available Root-knot nematodes induce galls that contain giant-feeding cells harboring multiple enlarged nuclei within the roots of host plants. It is recognized that the cell cycle plays an essential role in the set-up of a peculiar nuclear organization that seemingly steers nematode feeding site induction and development. Functional studies of a large set of cell cycle genes in transgenic lines of the model host Arabidopsis thaliana have contributed to better understand the role of the cell cycle components and their implication in the establishment of functional galls. Mitotic activity mainly occurs during the initial stages of gall development and is followed by an intense endoreduplication phase imperative to produce giant-feeding cells, essential to form vigorous galls. Transgenic lines overexpressing particular cell cycle genes can provoke severe nuclei phenotype changes mainly at later stages of feeding site development. This can result in chaotic nuclear phenotypes affecting their volume. These aberrant nuclear organizations are hampering gall development and nematode maturation. Herein we report on two nuclear volume assessment methods which provide information on the complex changes occurring in nuclei during giant cell development. Although we observed that the data obtained with AMIRA tend to be more detailed than Volumest (Image J, both approaches proved to be highly versatile, allowing to access 3D morphological changes in nuclei of complex tissues and organs. The protocol presented here is based on standard confocal optical sectioning and 3-D image analysis and can be applied to study any volume and shape of cellular organelles in various complex biological specimens. Our results suggest that an increase in giant cell nuclear volume is not solely linked to increasing ploidy levels, but might result from the accumulation of mitotic defects.

  13. National Assessment of Oil and Gas Project - Denver Basin Province (039) Quarter-Mile Cells

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Cell maps for each oil and gas assessment unit were created by the USGS as a method for illustrating the degree of exploration, type of production, and distribution...

  14. National Assessment of Oil and Gas Project - Sacramento Basin Province Quarter-Mile Cells

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Cell maps for each oil and gas assessment unit were created by the USGS to illustrate the degree of exploration, type of production, and distribution of production...

  15. National Assessment of Oil and Gas Project - Uinta-Piceance Province (020) Quarter-Mile Cells

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Cell maps for each oil and gas assessment unit were created by the USGS as a method for illustrating the degree of exploration, type of production, and distribution...

  16. National Assessment of Oil and Gas Project - San Juan Basin Province (022) Quarter-Mile Cells

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Cell maps for each oil and gas assessment unit were created by the USGS as a method for illustrating the degree of exploration, type of production, and distribution...

  17. National Assessment of Oil and Gas Project - Montana Thrust Belt Province (027) Quarter-Mile Cells

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Cell maps for each oil and gas assessment unit were created by the USGS as a method for illustrating the degree of exploration, type of production, and distribution...

  18. National Assessment of Oil and Gas Project - Illinois Basin Province (064) Quarter-Mile Cells

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Cell maps for each oil and gas assessment unit were created by the USGS to illustrate the degree of exploration, type of production, and distribution of production...

  19. National Assessment of Oil and Gas Project Bighorn Basin (5034) Quarter-Mile Cells

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Cell maps for each oil and gas assessment unit were created by the USGS to illustrate the degree of exploration, type of production, and distribution of production...

  20. National Assessment of Oil and Gas Project - Wyoming Thrust Belt (036) Quarter-Mile Cells

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Cell maps for each oil and gas assessment unit were created by the USGS as a method for illustrating the degree of exploration, type of production, and distribution...

  1. National Assessment of Oil and Gas Project - Powder River Basin Province (033) Quarter-Mile Cells

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Cell maps for each oil and gas assessment unit were created by the USGS as a method for illustrating the degree of exploration, type of production, and distribution...

  2. National Assessment of Oil and Gas Project - Southwestern Wyoming Province (037 Quarter-Mile Cells

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Cell maps for each oil and gas assessment unit were created by the USGS as a method for illustrating the degree of exploration, type of production, and distribution...

  3. National Assessment of Oil and Gas Project - Michigan Basin Province (063) Quarter-Mile Cells

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Cell maps for each oil and gas assessment unit were created by the USGS to illustrate the degree of exploration, type of production, and distribution of production...

  4. National Assessment of Oil and Gas Project - Black Warrior Province (065) Quarter-Mile Cells

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Cell maps for each oil and gas assessment unit were created by the USGS as a method for illustrating the degree of exploration, type of production, and distribution...

  5. National Assessment of Oil and Gas Project - Eastern Great Basin Province (019) Quarter-Mile Cells

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Cell maps for each oil and gas assessment unit were created by the USGS as a method for illustrating the degree of exploration, type of production, and distribution...

  6. National Assessment of Oil and Gas Project - Appalachian Basin (067) Quarter-Mile Cells

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Cell maps for each oil and gas assessment unit were created by the USGS as a method for illustrating the degree of exploration, type of production, and distribution...

  7. The Cool ISM in Elliptical Galaxies. II. Gas Content in the Volume - Limited Sample and Results from the Combined Elliptical and Lenticular Surveys

    CERN Document Server

    Welch, Gary A; Young, Lisa M

    2010-01-01

    We report new observations of atomic and molecular gas in a volume limited sample of elliptical galaxies. Combining the elliptical sample with an earlier and similar lenticular one, we show that cool gas detection rates are very similar among low luminosity E and SO galaxies but are much higher among luminous S0s. Using the combined sample we revisit the correlation between cool gas mass and blue luminosity which emerged from our lenticular survey, finding strong support for previous claims that the molecular gas in ellipticals and lenticulars has different origins. Unexpectedly, however, and contrary to earlier claims, the same is not true for atomic gas. We speculate that both the AGN feedback and merger paradigms might offer explanations for differences in detection rates, and might also point towards an understanding of why the two gas phases could follow different evolutionary paths in Es and S0s. Finally we present a new and puzzling discovery concerning the global mix of atomic and molecular gas in ear...

  8. Natural gas monthly, May 1994

    Energy Technology Data Exchange (ETDEWEB)

    1994-05-25

    The Natural Gas Monthly (NGM) highlights activities, events, and analyses of interest to public and private sector organizations associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer-related activities and underground storage data are also reported. From time to time, the NGM features articles designed to assist readers in using and interpreting natural gas information. The featured articles for this month are: Opportunities with fuel cells, and revisions to monthly natural gas data.

  9. Minimal volume regulation after shrinkage of red blood cells from five species of reptiles

    DEFF Research Database (Denmark)

    Kristensen, Karina; Berenbrink, Michael; Koldkjær, Pia

    2008-01-01

    Red blood cells (RBCs) from most vertebrates restore volume upon hypertonic shrinkage and the mechanisms underlying this regulatory volume increase (RVI) have been studied extensively in these cells. Despite the phylogenetically interesting position of reptiles, very little is known about their red...... cell function. The present study demonstrates that oxygenated RBCs in all major groups of reptiles exhibit no or a very reduced RVI upon ~ 25% calculated hyperosmotic shrinkage. Thus, RBCs from the snakes Crotalus durissus and Python regius, the turtle Trachemys scripta and the alligator Alligator...... was not characterized. It seems, therefore, that the RVI response based on NHE activation was lost among the early sauropsids that gave rise to modern reptiles and birds, while it was retained in mammals. An RVI response has then reappeared in birds, but based on activation of the NKCC. Alternatively, the absence...

  10. Resonant microchannel volume and mass measurements show that suspended cells swell during mitosis.

    Science.gov (United States)

    Son, Sungmin; Kang, Joon Ho; Oh, Seungeun; Kirschner, Marc W; Mitchison, T J; Manalis, Scott

    2015-11-23

    Osmotic regulation of intracellular water during mitosis is poorly understood because methods for monitoring relevant cellular physical properties with sufficient precision have been limited. Here we use a suspended microchannel resonator to monitor the volume and density of single cells in suspension with a precision of 1% and 0.03%, respectively. We find that for transformed murine lymphocytic leukemia and mouse pro-B cell lymphoid cell lines, mitotic cells reversibly increase their volume by more than 10% and decrease their density by 0.4% over a 20-min period. This response is correlated with the mitotic cell cycle but is not coupled to nuclear osmolytes released by nuclear envelope breakdown, chromatin condensation, or cytokinesis and does not result from endocytosis of the surrounding fluid. Inhibiting Na-H exchange eliminates the response. Although mitotic rounding of adherent cells is necessary for proper cell division, our observations that suspended cells undergo reversible swelling during mitosis suggest that regulation of intracellular water may be a more general component of mitosis than previously appreciated.

  11. Effect of radiologic contrast media on cell volume regulation in rabbit proximal renal tubules.

    Science.gov (United States)

    Galtung, H K; Løken, M; Sakariassen, K S

    2001-05-01

    Most radiographic contrast media are hyperosmotic and able to shrink cells with which they are in contact. The authors studied cell volume control in rabbit proximal renal tubules after incubation with three contrast media: iohexol, ioxaglate, and iodixanol. Proximal renal tubules were isolated from rabbit kidneys. The tubules were exposed to Ringer solutions containing 5% vol/vol iohexol (final osmolality, 330 mOsm), ioxaglate (323 mOsm), iodixanol (305 mOsm), or mannitol (control solutions with identical osmolalities), and tubule volumes were monitored. After 2 hours of incubation, the tubules were stimulated with a hyposmotic Ringer solution (165 mOsm). Three groups of 10 experiments were performed. All solutions induced cell shrinkage (8.3%+/-3.8 [standard error] to 15.4%+/-0.5), which was completely or partly reversible in most experiments (volume increase, 44.8%+/-14.7 to 149.9%+/-107.3) but not those with iohexol and iodixanol. With exposure to the hyposmotic solution, the cells swelled by 11.0%+/-1.8 to 39.7%+/-4.8. In general, the tubules that had been exposed to the most hyperosmotic solution swelled the most. Those exposed to contrast media showed less swelling than the mannitol-exposed controls. In all control experiments, the cells exhibited a gradual shrinkage (43.6%+/-28.5 to 87.0%+/-13). This regulatory response was partly inhibited in tubules exposed to iohexol (39.9%+/-15.8 shrinkage) or iodixanol (8.9%+/-15.8) and completely inhibited in those exposed to ioxaglate. Iohexol and ioxaglate exposure also led to a decrease in water permeability. Exposure to hyperosmotic contrast medium tends to induce prolonged cell shrinkage, decrease the water permeability of the cellular plasma membranes, and compromise the ability to regulate cellular volume. These changes seem to reflect both the hyperosmolality of the solutions and their inherent chemical properties.

  12. Heteromeric Slick/Slack K+ channels show graded sensitivity to cell volume changes

    DEFF Research Database (Denmark)

    Tejada, Maria A; Hashem, Nadia; Callø, Kirstine

    2017-01-01

    Slick and Slack high-conductance K+ channels are found in the CNS, kidneys, pancreas, among other organs, where they play an important role in cell excitability as well as in ion transport processes. They are both activated by Na+ and Cl- but show a differential regulation by cell volume changes...... to osmotic challenges. In order to provide with the adequate water permeability to the cell membrane of Xenopus laevis oocytes, mRNA of aquaporin 1 was co-expressed with homomeric or heteromeric Slick and Slack α-subunits. Oocytes were superfused with hypotonic or hypertonic buffers and changes in currents...

  13. Life-threatening megaloblastic pancytopenia with normal mean cell volume: case series

    Science.gov (United States)

    Sekhar, Jeevan; Stabler, Sally P.

    2007-01-01

    The mean red blood cell volume (MCV) is usually increased in severe megaloblastic anemia due to pernicious anemia. However, during one year in a university hospital, three patients with life-threatening pancytopenia and normal MCV were proven to have severe vitamin B12 deficiency. The red blood cell distribution width was markedly increased (three times normal) and led to review of the blood smear and recognition of megaloblastosis as well as prominent red cell fragmentation. These three cases illustrate that vitamin B12 status should be evaluated in cases of pancytopenia, independent of the MCV value. PMID:17967337

  14. Thermodynamic simulation of biomass gas steam reforming for a solid oxide fuel cell (SOFC system

    Directory of Open Access Journals (Sweden)

    A. Sordi

    2009-12-01

    Full Text Available This paper presents a methodology to simulate a small-scale fuel cell system for power generation using biomass gas as fuel. The methodology encompasses the thermodynamic and electrochemical aspects of a solid oxide fuel cell (SOFC, as well as solves the problem of chemical equilibrium in complex systems. In this case the complex system is the internal reforming of biomass gas to produce hydrogen. The fuel cell input variables are: operational voltage, cell power output, composition of the biomass gas reforming, thermodynamic efficiency, electrochemical efficiency, practical efficiency, the First and Second law efficiencies for the whole system. The chemical compositions, molar flows and temperatures are presented to each point of the system as well as the exergetic efficiency. For a molar water/carbon ratio of 2, the thermodynamic simulation of the biomass gas reforming indicates the maximum hydrogen production at a temperature of 1070 K, which can vary as a function of the biomass gas composition. The comparison with the efficiency of simple gas turbine cycle and regenerative gas turbine cycle shows the superiority of SOFC for the considered electrical power range.

  15. Laser spectroscopy with nanometric cells containing atomic vapor of metal: influence of buffer gas

    Science.gov (United States)

    Sarkisyan, D.; Hakhumyan, G.; Sargsyan, A.; Mirzoyan, R.; Leroy, C.; Pashayan-Leroy, Y.

    2010-10-01

    Comparison of absorption and fluorescence in a nano-cell containing Rb vapor with other Rb nano-cells with addition of neon gas is presented. It is shown that the effect of collapse and revival of Dicke-type narrowing occurs for Rb nanocells containing N2 as buffer gas under 6 and 20 Torr pressure for the thickness L = λ /2 and L = where λ is the resonant λ, laser wavelength 794 nm (D1 line). Particularly for 6 Torr the line-width of the transmission spectrum for the thickness L =λ/2 is 2 times narrower than that for L = λ. For an ordinary Rb cell with L = 0.1 - 10 cm with addition of buffer gas, the velocity selective optical pumping/saturation (VSOP) resonances in saturated absorption spectra are fully suppressed when the buffer gas pressure > 0.5 Torr. A spectacular difference is that for L = λ, VSOP resonances located at the atomic transitions are still observable even when Ne pressure is >= 6 Torr. Narrowband fluorescence spectra of a nano-cell with L = λ/2 can be used as a convenient tool for online buffer gas pressure monitoring for the conditions when ordinary pressure gauges are unusable. Comparison of electromagnetically induced transparency (EIT) effect in a nano-cell filled with pure (without a buffer gas) Rb with another nano-cell, where buffer gas nitrogen is added, is presented. The use of N2 gas inside Rb nano-cells strongly extends the range of coupling laser detunings in which it is still possible to form EIT resonance.

  16. Involvement of regulatory volume decrease in the migration of nasopharyngeal carcinoma cells

    Institute of Scientific and Technical Information of China (English)

    Jian Wen MAO; Li Xin CHEN; Li Wei WANG; Tim JACOB; Xue Rong SUN; Hui LI; Lin Yan ZHU; Pan LI; Ping ZHONG; Si Huai NIE

    2005-01-01

    The transwell chamber migration assay and CCD digital camera imaging techniques were used to investigate the relationship between regulatory volume decrease (RVD) and cell migration in nasopharyngeal carcinoma cells (CNE-2Z cells). Both migrated and non-migrated CNE-2Z cells, when swollen by 47% hypotonic solution, exhibited RVD which was inhibited by extracellular application of chloride channel blockers adenosine 5'-triphosphate (ATP), 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB) and tamoxifen. However, RVD rate in migrated CNE-2Z cells was bigger than that of non-migrated cells and the sensitivity of migrated cells to NPPB and tamoxifen was higher than that of nonmigrated cells. ATP, NPPB and tamoxifen also inhibited migration of CNE-2Z cells. The inhibition of migration was positively correlated to the blockage of RVD, with a correlation coefficient (r) = 0.99, suggesting a functional relationship between RVD and cell migration. We conclude that RVD is involved in cell migration and RVD may play an important role in migratory process in CNE-2Z cells.

  17. Rate and peak concentrations of off-gas emissions in stored wood pellets--sensitivities to temperature, relative humidity, and headspace volume.

    Science.gov (United States)

    Kuang, Xingya; Shankar, Tumuluru Jaya; Bi, Xiaotao T; Lim, C Jim; Sokhansanj, Shahab; Melin, Staffan

    2009-11-01

    Wood pellets emit CO, CO(2), CH(4), and other volatiles during storage. Increased concentration of these gases in a sealed storage causes depletion of concentration of oxygen. The storage environment becomes toxic to those who operate in and around these storages. The objective of this study was to investigate the effects of temperature, moisture, and the relative size of storage headspace on emissions from wood pellets in an enclosed space. Twelve 10-l plastic containers were used to study the effects of headspace ratio (25, 50, and 75% of container volume) and temperatures (10-50 degrees C). Another eight containers were set in uncontrolled storage relative humidity (RH) and temperature. Concentrations of CO(2), CO, and CH(4) were measured by gas chromatography (GC). The results showed that emissions of CO(2), CO, and CH(4) from stored wood pellets are more sensitive to storage temperature than to RH and the relative volume of headspace. Higher peak emission factors are associated with higher temperatures. Increased headspace volume ratio increases peak off-gas emissions because of the availability of oxygen associated with pellet decomposition. Increased RH in the enclosed container increases the rate of off-gas emissions of CO(2), CO, and CH(4) and oxygen depletion.

  18. Cell cycle-dependent activity of the volume- and Ca2+-activated anion currents in Ehrlich lettre ascites cells

    DEFF Research Database (Denmark)

    Klausen, Thomas Kjaer; Bergdahl, Andreas; Christophersen, Palle

    2007-01-01

    Recent evidence implicates the volume-regulated anion current (VRAC) and other anion currents in control or modulation of cell cycle progression; however, the precise involvement of anion channels in this process is unclear. Here, Cl- currents in Ehrlich Lettre Ascites (ELA) cells were monitored...... during cell cycle progression, under three conditions: (i) after osmotic swelling (i.e., VRAC), (ii) after an increase in the free intracellular Ca2+ concentration (i.e., the Ca2+-activated Cl- current, CaCC), and (iii) under steady-state isotonic conditions. The maximal swelling-activated VRAC current......+ in the pipette), was unaltered from G0 to G1, but decreased in early S phase. A novel high-affinity anion channel inhibitor, the acidic di-aryl-urea NS3728, which inhibited both VRAC and CaCC, attenuated ELA cell growth, suggesting a possible mechanistic link between cell cycle progression and cell cycle...

  19. Performance of PEM fuel cells stack as affected by number of cell and gas flow-rate

    Science.gov (United States)

    Syampurwadi, A.; Onggo, H.; Indriyati; Yudianti, R.

    2017-03-01

    The proton exchange membrane fuel cell (PEMFC) is a promising technology as an alternative green energy due to its high power density, low operating temperatures, low local emissions, quiet operation and fast start up-shutdown. In order to apply fuel cell as portable power supply, the performance investigation of small number of cells is needed. In this study, PEMFC stacks consisting of 1, 3, 5 and 7-cells with an active area of 25 cm2 per cell have been designed and developed. Their was evaluated in variation of gas flow rate. The membrane electrode assembly (MEA) was prepared by hot-pressing commercial gas diffusion electrodes (Pt loading 0.5 mg/cm2) on pre-treated Nafion 117 membrane. The stacks were constructed using bipolar plates in serpentine pattern and Z-type gas flow configuration. The experimental results were presented as polarization and power output curves which show the effects of varying number of cells and H2/O2 flow-rates on the PEMFC performance. The experimental results showed that not only number of cells and gas flow-rates affected the fuel cells performance, but also the operating temperature as a result of electrochemistry reaction inside the cell.

  20. Modeling of gas turbine - solid oxide fuel cell systems for combined propulsion and power on aircraft

    Science.gov (United States)

    Waters, Daniel Francis

    This dissertation investigates the use of gas turbine (GT) engine integrated solid oxide fuel cells (SOFCs) to reduce fuel burn in aircraft with large electrical loads like sensor-laden unmanned air vehicles (UAVs). The concept offers a number of advantages: the GT absorbs many SOFC balance of plant functions (supplying fuel, air, and heat to the fuel cell) thereby reducing the number of components in the system; the GT supplies fuel and pressurized air that significantly increases SOFC performance; heat and unreacted fuel from the SOFC are recaptured by the GT cycle offsetting system-level losses; good transient response of the GT cycle compensates for poor transient response of the SOFC. The net result is a system that can supply more electrical power more efficiently than comparable engine-generator systems with only modest (capture `down-the-channel' effects (a level of fidelity necessary for making meaningful performance, mass, and volume estimates). Models are created in a NASA-developed environment called Numerical Propulsion System Simulation (NPSS). A sensitivity analysis identifies important design parameters and translates uncertainties in model parameters into uncertainties in overall performance. GT-SOFC integrations reduce fuel burn 3-4% in 50 kW systems on 35 kN rated engines (all types) with overall uncertainty 3 in some cases) than generator-based systems before encountering turbine inlet temperature limits. Aerodynamic drag effects of engine-airframe integration are by far the most important limiter of the combined propulsion/electrical generation concept. However, up to 100-200 kW can be produced in a bypass ratio = 8, overall pressure ratio = 40 turbofan with little or no drag penalty. This study shows that it is possible to create cooperatively integrated GT-SOFC systems for combined propulsion and power with better overall performance than stand-alone components.

  1. Determination of Shale Volume and Distribution Patterns and Effective Porosity from Well Log Data Based On Cross-Plot Approach for A Shaly Carbonate Gas Reservoir

    Science.gov (United States)

    Moradi, Siyamak; Moeini, Mohammad; Kamal Ghassem al-Askari, Mohammad; Hamed Mahvelati, Elaheh

    2016-10-01

    Determination of shale volume distribution is one of the most important factors that has to be considered in formation evaluation, since existence of shale reduces effective porosity and permeability of the reservoir. In this paper, shale volume and distribution (dispersed, laminar and structural) and formation effective porosity are estimated from well log data and cross-plots. Results show that distribution of shale is mainly dispersed with few of laminar ones, and the quality of reservoir (effective porosity) decreases with depth resulting in low productivity of gas wells drilled in lower zones. Good agreement of estimated shale volumes and effective porosities from neutron-density cross-plot with the values determined from gamma ray log (CGR) and core analysis demonstrates the accuracy and applicability of these plots in determination of petrophysical parameters from conventional log data.

  2. Small-volume storage facilities as alternative flexibility instruments in the procurement portfolio of large natural gas suppliers; Kleinvolumige Speicher als alternative Flexibilitaetsinstrumente im Bezugsportfolio grosser Erdgasversorger

    Energy Technology Data Exchange (ETDEWEB)

    Deschkan, Peter [WIEN ENERGIE Speicher GmbH, Wien (Austria)

    2012-11-15

    This article analyses the positive economic effects of small-volume storage facilities on the management of the medium to long-term natural gas procurement portfolio of a major urban supplier in the context of the liberalized Austrian market in natural gas. Due to low investment and operating costs and short construction times, these facilities represent attractive possibilities, for instance for public utility companies, in structuring their natural gas procurement. However, unlike storage products normally available on the market, which also facilitate seasonal balancing between supply and demand, they can only be used in the context of influencing the daily and hourly loads (peak shaving). Below, we examine the effects of including small-volume storage facilities (such as pipe storage) on the cost situation of the natural gas supplier for various consumption patterns and customer structures, as part of an optimization model. The results of the analysis indicate the obvious benefits in the case of load patterns strongly influenced by temperature that decline significantly with decreasing share of heating load. (orig.)

  3. Computer aided classification of cell nuclei in the gastrointestinal tract by volume and principal axis

    Science.gov (United States)

    Sagstetter, Ann M.; Camp, Jon J.; Lurken, Matthew S.; Szurszewski, Joseph H.; Farrugia, Gianrico; Gibbons, Simon J.; Robb, Richard A.

    2007-03-01

    Normal function of the gastrointestinal tract involves the coordinated activity of several cell types Human disorders of motor function of the gastrointestinal tract are often associated with changes in the number of these cells. For example, in diabetic patients, abnormalities in gastrointestinal transit are associated with changes in nerves and interstitial cells of Cajal (ICC), two key cells that generate and regulate motility. ICC are cells of mesenchymal origin that function as pacemakers and amplify neuronal signals in the gastrointestinal tract. Quantifying the changes in number of specific cell types in tissues from patients with motility disorders is challenging and requires immunolabeling for specific antigens. The shape of nuclei differs between the cell types in the wall of the gastrointestinal tract. Therefore the objective of this study was to determine whether cell nuclei can be classified by analyzing the 3D morphology of the nuclei. Furthermore, the orientation of the long axis of nuclei changes within and between the muscle layers. These features can be used to classify and differentially label the nuclei in confocal volume images of the tissue by computing the principal axis of the coordinates of the set of voxels forming each nucleus and thereby to identify cells by their nuclear morphology. Using this approach, we were able to separate and quantify nuclei in the smooth muscle layers of the tissue. Therefore we conclude that computer-aided classification of cell nuclei can be used to identify changes in the cell types expressed in gastrointestinal smooth muscle.

  4. A new MODIS based approach for gas flared volumes estimation: the case of the Val d'Agri Oil Center (Southern Italy)

    Science.gov (United States)

    Lacava, T.; Faruolo, M.; Coviello, I.; Filizzola, C.; Pergola, N.; Tramutoli, V.

    2014-12-01

    Gas flaring is one of the most controversial energetic and environmental issues the Earth is facing, moreover contributing to the global warming and climate change. According to the World Bank, each year about 150 Billion Cubic Meter of gas are being flared globally, that is equivalent to the annual gas use of Italy and France combined. Besides, about 400 million tons of CO2 (representing about 1.2% of global CO2 emissions) are added annually into the atmosphere. Efforts to evaluate the impact of flaring on the surrounding environment are hampered by lack of official information on flare locations and volumes. Suitable satellite based techniques could offers a potential solution to this problem through the detection and subsequent mapping of flare locations as well as gas emissions estimation. In this paper a new methodological approach, based on the Robust Satellite Techniques (RST), a multi-temporal scheme of satellite data analysis, was developed to analyze and characterize the flaring activity of the largest Italian gas and oil pre-treatment plant (ENI-COVA) located in Val d'Agri (Basilicata) For this site, located in an anthropized area characterized by a large environmental complexity, flaring emissions are mainly related to emergency conditions (i.e. waste flaring), being the industrial process regulated by strict regional laws. With reference to the peculiar characteristics of COVA flaring, the RST approach was implemented on 13 years of EOS-MODIS (Earth Observing System - Moderate Resolution Imaging Spectroradiometer) infrared data to detect COVA-related thermal anomalies and to develop a regression model for gas flared volume estimation. The methodological approach, the whole processing chain and the preliminarily achieved results will be shown and discussed in this paper. In addition, the possible implementation of the proposed approach on the data acquired by the SUOMI NPP - VIIRS (National Polar-orbiting Partnership - Visible Infrared Imaging

  5. Enrichment of diluted cell populations from large sample volumes using 3D carbon-electrode dielectrophoresis.

    Science.gov (United States)

    Islam, Monsur; Natu, Rucha; Larraga-Martinez, Maria Fernanda; Martinez-Duarte, Rodrigo

    2016-05-01

    Here, we report on an enrichment protocol using carbon electrode dielectrophoresis to isolate and purify a targeted cell population from sample volumes up to 4 ml. We aim at trapping, washing, and recovering an enriched cell fraction that will facilitate downstream analysis. We used an increasingly diluted sample of yeast, 10(6)-10(2) cells/ml, to demonstrate the isolation and enrichment of few cells at increasing flow rates. A maximum average enrichment of 154.2 ± 23.7 times was achieved when the sample flow rate was 10 μl/min and yeast cells were suspended in low electrically conductive media that maximizes dielectrophoresis trapping. A COMSOL Multiphysics model allowed for the comparison between experimental and simulation results. Discussion is conducted on the discrepancies between such results and how the model can be further improved.

  6. New stopping cell capabilities : RF carpet performance at high gas density and cryogenic operation

    NARCIS (Netherlands)

    Ranjan, M.; Purushothaman, S.; Dickel, T.; Geissel, H.; Plass, W. R.; Schaefer, D.; Scheidenberger, C.; Van de Walle, J.; Weick, H.; Dendooven, P.

    2011-01-01

    We have developed a stopping cell to be used at the FRS and Super-FRS (Superconducting FRagment Separator) at the GSI Helmholtz Centre for Heavy-Ion Research and the Facility for Antiproton and Ion Research (FAIR), both in Darmstadt, Germany. The cell has a stopping volume with a length of 1m and a

  7. DEVELOPMENT OF A NATURAL GAS SYSTEMS ANALYSIS MODEL (GSAM) VOLUME I - SUMMARY REPORT VOLUME II - USER'S GUIDE VOLUME IIIA - RP PROGRAMMER'S GUIDE VOLUME IIIB - SRPM PROGRAMMER'S GUIDE VOLUME IIIC - E&P PROGRAMMER'S GUIDE VOLUME IIID - D&I PROGRAMMER'S GUIDE

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    2001-02-01

    This report summarizes work completed on DOE Contract DE-AC21-92MC28138, Development of a Natural Gas Systems Analysis Model (GSAM). The products developed under this project directly support the National Energy Technology Laboratory (NETL) in carrying out its natural gas R&D mission. The objective of this research effort has been to create a comprehensive, non-proprietary, microcomputer model of the North American natural gas market. GSAM has been developed to explicitly evaluate components of the natural gas system, including the entire in-place gas resource base, exploration and development technologies, extraction technology and performance parameters, transportation and storage factors, and end-use demand issues. The system has been fully tested and calibrated and has been used for multiple natural gas metrics analyses at NETL in which metric associated with NETL natural gas upstream R&D technologies and strategies under the direction of NETL has been evaluated. NETL's Natural Gas Strategic Plan requires that R&D activities be evaluated for their ability to provide adequate supplies of reasonably priced natural gas. GSAM provides the capability to assess potential and on-going R&D projects using a full fuel cycle, cost-benefit approach. This method yields realistic, market-based assessments of benefits and costs of alternative or related technology advances. GSAM is capable of estimating both technical and commercial successes, quantifying the potential benefits to the market, as well as to other related research. GSAM, therefore, represents an integration of research activities and a method for planning and prioritizing efforts to maximize benefits and minimize costs. Without an analytical tool like GSAM, NETL natural gas upstream R&D activities cannot be appropriately ranked or focused on the most important aspects of natural gas extraction efforts or utilization considerations.

  8. Influence of flotation cell volume and solids mass on kinetics of sulfide ore flotation

    Directory of Open Access Journals (Sweden)

    Plawski Michal

    2016-01-01

    Full Text Available The paper presents studies on the influence of flotation cell capacity and mass of solids in the suspension on the flotation kinetics of sulfide copper ore. A sample of copper ore that was collected from the Polkowice Mine of KGHM Polska Miedz S.A. in Poland was used in the experiments. It was determined that neither the volume of flotation cell nor the mass of solids had influence on the type of kinetics equation of flotation. Copper-bearing minerals floated according to the second-order equation, while the remaining components according to the first-order equation. The kinetic rate constants and maximum recovery of the studied components decreased with increasing solids mass in the flotation cell, regardless of the capacity of the cell. The best results were obtained for tests using a 1.0 dm3 cell, while the less favorable kinetics results were observed in the test with the smallest cell of 0.75 dm3 volume. The obtained results can be helpful in choosing the most appropriate methodology of upgrading the sulfide copper ore from Poland in order to obtain the best kinetics results.

  9. Streaming Model Based Volume Ray Casting Implementation for Cell Broadband Engine

    Directory of Open Access Journals (Sweden)

    Jusub Kim

    2009-01-01

    Full Text Available Interactive high quality volume rendering is becoming increasingly more important as the amount of more complex volumetric data steadily grows. While a number of volumetric rendering techniques have been widely used, ray casting has been recognized as an effective approach for generating high quality visualization. However, for most users, the use of ray casting has been limited to datasets that are very small because of its high demands on computational power and memory bandwidth. However the recent introduction of the Cell Broadband Engine (Cell B.E. processor, which consists of 9 heterogeneous cores designed to handle extremely demanding computations with large streams of data, provides an opportunity to put the ray casting into practical use. In this paper, we introduce an efficient parallel implementation of volume ray casting on the Cell B.E. The implementation is designed to take full advantage of the computational power and memory bandwidth of the Cell B.E. using an intricate orchestration of the ray casting computation on the available heterogeneous resources. Specifically, we introduce streaming model based schemes and techniques to efficiently implement acceleration techniques for ray casting on Cell B.E. In addition to ensuring effective SIMD utilization, our method provides two key benefits: there is no cost for empty space skipping and there is no memory bottleneck on moving volumetric data for processing. Our experimental results show that we can interactively render practical datasets on a single Cell B.E. processor.

  10. Diffusion on a curved surface coupled to diffusion in the volume: Application to cell biology

    Science.gov (United States)

    Novak, Igor L.; Gao, Fei; Choi, Yung-Sze; Resasco, Diana; Schaff, James C.; Slepchenko, Boris M.

    2007-10-01

    An algorithm is presented for solving a diffusion equation on a curved surface coupled to diffusion in the volume, a problem often arising in cell biology. It applies to pixilated surfaces obtained from experimental images and performs at low computational cost. In the method, the Laplace-Beltrami operator is approximated locally by the Laplacian on the tangential plane and then a finite volume discretization scheme based on a Voronoi decomposition is applied. Convergence studies show that mass conservation built in the discretization scheme and cancellation of sampling error ensure convergence of the solution in space with an order between 1 and 2. The method is applied to a cell-biological problem where a signaling molecule, G-protein Rac, cycles between the cytoplasm and cell membrane thus coupling its diffusion in the membrane to that in the cell interior. Simulations on realistic cell geometry are performed to validate, and determine the accuracy of, a recently proposed simplified quantitative analysis of fluorescence loss in photobleaching. The method is implemented within the Virtual Cell computational framework freely accessible at http://www.vcell.org.

  11. Correlation of live-cell imaging with volume scanning electron microscopy.

    Science.gov (United States)

    Lucas, Miriam S; Günthert, Maja; Bittermann, Anne Greet; de Marco, Alex; Wepf, Roger

    2017-01-01

    Live-cell imaging is one of the most widely applied methods in live science. Here we describe two setups for live-cell imaging, which can easily be combined with volume SEM for correlative studies. The first procedure applies cell culture dishes with a gridded glass support, which can be used for any light microscopy modality. The second approach is a flow-chamber setup based on Ibidi μ-slides. Both live-cell imaging strategies can be followed up with serial blockface- or focused ion beam-scanning electron microscopy. Two types of resin embedding after heavy metal staining and dehydration are presented making best use of the particular advantages of each imaging modality: classical en-bloc embedding and thin-layer plastification. The latter can be used only for focused ion beam-scanning electron microscopy, but is advantageous for studying cell-interactions with specific substrates, or when the substrate cannot be removed. En-bloc embedding has diverse applications and can be applied for both described volume scanning electron microscopy techniques. Finally, strategies for relocating the cell of interest are discussed for both embedding approaches and in respect to the applied light and scanning electron microscopy methods. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Gas6 induces cancer cell migration and epithelial–mesenchymal transition through upregulation of MAPK and Slug

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yunhee [Department of Chemistry, Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Immunotherapy Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon (Korea, Republic of); Lee, Mira [Immunotherapy Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon (Korea, Republic of); Kim, Semi, E-mail: semikim@kribb.re.kr [Department of Chemistry, Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Immunotherapy Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon (Korea, Republic of)

    2013-04-26

    Highlights: •We investigated the molecular mechanisms underlying Gas6-mediated cancer cell migration. •Gas6 treatment and subsequent Axl activation induce cell migration and EMT via upregulation of Slug. •Slug expression mediated by Gas6 is mainly through c-Jun and ATF-2 in an ERK1/2 and JNK-dependent manner. •The Gas6/Axl-Slug axis may be exploited as a target for anti-cancer metastasis therapy. -- Abstract: Binding of Gas6 to Axl (Gas6/Axl axis) alters cellular functions, including migration, invasion, proliferation, and survival. However, the molecular mechanisms underlying Gas6-mediated cell migration remain poorly understood. In this study, we found that Gas6 induced the activation of JNK and ERK1/2 signaling in cancer cells expressing Axl, resulting in the phosphorylation of activator protein-1 (AP-1) transcription factors c-Jun and ATF-2, and induction of Slug. Depletion of c-Jun or ATF-2 by siRNA attenuated the Gas6-induced expression of Slug. Slug expression was required for cell migration and E-cadherin reduction/vimentin induction induced by Gas6. These results suggest that Gas6 induced cell migration via Slug upregulation in JNK- and ERK1/2-dependent mechanisms. These data provide an important insight into the molecular mechanisms mediating Gas6-induced cell migration.

  13. High temperature and high pressure gas cell for quantitative spectroscopic measurements

    DEFF Research Database (Denmark)

    Christiansen, Caspar; Stolberg-Rohr, Thomine; Fateev, Alexander

    2016-01-01

    A high temperature and high pressure gas cell (HTPGC) has been manufactured for quantitative spectroscopic measurements in the pressure range 1-200 bar and temperature range 300-1300 K. In the present work the cell was employed at up to 100 bar and 1000 K, and measured absorption coefficients...

  14. Effect of cathode gas humidification on performance and durability of Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Nielsen, Jimmi; Hagen, Anke; Liu, Yi-Lin

    2010-01-01

    The effect of cathode inlet gas humidification was studied on single anode supported Solid Oxide Fuel Cells (SOFC's). The studied cells were Risø 2 G and 2.5 G. The former consists of a LSM:YSZ composite cathode, while the latter consists of a LSCF:CGO composite cathode on a CGO protection layer...

  15. DEMONSTRATION OF FUEL CELLS TO RECOVER ENERGY FROM LANDFILL GAS - PHASE I FINAL REPORT: CONCEPTUAL STUDY

    Science.gov (United States)

    The report discusses results of a conceptual design, cost, and evaluation study of energy recovery from landfill gas using a commercial phosphoric acid fuel cell power plant. The conceptual design of the fuel cell energy recovery system is described, and its economic and environm...

  16. Measurement of background gas in paraffin-coated alkali vapor cells

    CERN Document Server

    Sekiguchi, Naota

    2015-01-01

    We measured the rate of velocity-changing collisions (VCCs) between alkali atoms and background gas in buffer-gas-free anti-spin-relaxation-coated cells. The average VCC rate in paraffin-coated rubidium vapor cells prepared in this work was $1 \\times 10^{6}$ s$^{-1}$, which corresponds to $\\sim$1 mm in the mean free path of rubidium atoms. This short mean free path indicates that alkali atoms do not travel freely between the cell walls. In addition, we found that a heating process known as "ripening" increases the VCC rate, and also confirmed that ripening improves the anti-relaxation performance of the coatings.

  17. Analysis of Gas Leakage and Current Loss of Solid Oxide Fuel Cells by Screen Printing

    DEFF Research Database (Denmark)

    Jia, Chuan; Han, Minfang; Chen, Ming

    2017-01-01

    calculated. Their performances of electrochemical impedance spectroscopy (EIS) were compared and distribution function of relaxation times (DRT) technique was also used to find the clue of gas leakage. Finally, thinning and penetrating holes were observed in electrolyte layer, which confirmed the occurrence......Two types of anode supported solid oxide fuel cell (SOFC) NiO-YSZ/YSZ/GDC/LSCF with the same structure and different manufacturing process were tested. Gas leakage was suspected for cells manufactured with screen printing technique. Effective leak current densities for both types of cells were...

  18. Feasibility study for alternate fuels production: unconventional natural gas from wastewater treatment plants. Volume II, Appendix D. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Overly, P.; Tawiah, K.

    1981-12-01

    Data are presented from a study performed to determined the feasibility of recovering methane from sewage at a typical biological secondary wastewater treatment plant. Three tasks are involved: optimization of digester gas; digester gas scrubbing; and application to the East Bay Municipal Utility District water pollution control plant. Results indicate that excess digester gas can be used economically at the wastewater treatment plant and that distribution and scrubbing can be complex and costly. (DMC) 193 references, 93 figures, 26 tables.

  19. Study of fuel cell and gas turbine hybrid power systems

    OpenAIRE

    Basurto, M. T.

    2002-01-01

    Environmental awareness and the interest in distributed generation caused by electricity market de-regulation are factors that promote research on renewable energies. Fuel cells transform the chemical energy stored in fuel into electricity by means of electrochemical reactions. Among the different fuel cell types, high temperature fuel cells (HTFCS) have many advantages: high efficiency, low emissions, fuel flexibility, modularity and high quality waste heat. The main disadvant...

  20. Current Injection Provokes Rapid Expansion of the Guard Cell Cytosolic Volume and Triggers Ca(2+) Signals.

    Science.gov (United States)

    Voss, Lena J; Hedrich, Rainer; Roelfsema, M Rob G

    2016-03-07

    High-resolution microscopy opens the door for detailed single-cell studies with fluorescent reporter dyes and proteins. We used a confocal spinning disc microscope to monitor fluorescent dyes and the fluorescent protein Venus in tobacco and Arabidopsis guard cells. Multi-barreled microelectrodes were used to inject dyes and apply voltage pulses, which provoke transient rises in the cytosolic Ca(2+) level. Voltage pulses also caused changes in the distribution of Lucifer Yellow and Venus, which pointed to a reversible increase of guard cell cytosolic volume. The dynamic cytosolic volume changes turned out to be provoked by current injection of ions. A reduction of the clamp current, by blocking K(+) uptake channels with Cs(+), strongly suppressed the cytosolic volume changes. Cs(+) not only inhibited the expansion of the cytosol, but also inhibited hyperpolarization-induced elevations of the cytosolic Ca(2+) concentration. A complete loss of voltage-induced Ca(2+) signals occurred when Ca(2+)-permeable plasma membrane channels were simultaneously blocked with La(3+). This shows that two mechanisms cause hyperpolarization-induced elevation of the cytosolic Ca(2+)-concentration: (i) activation of voltage-dependent Ca(2+)-permeable channels, (ii) osmotically induced expansion of the cytosol, which leads to a release of Ca(2+) from intracellular stores.

  1. Synapse loss from chronically elevated glucocorticoids: relationship to neuropil volume and cell number in hippocampal area CA3.

    Science.gov (United States)

    Tata, Despina A; Marciano, Veronica A; Anderson, Brenda J

    2006-09-20

    Individuals with clinical disorders associated with elevated plasma glucocorticoids, such as major depressive disorder and Cushing's syndrome, are reported to have smaller hippocampal volume. To understand how the hippocampus responds at the cellular and subcellular levels to glucocorticoids and how such changes are related to volume measures, we have undertaken a comprehensive study of glucocorticoid effects on hippocampal CA3 volume and identified elements in the neuropil including astrocytic volume and cell and synapse number and size. Male Sprague-Dawley rats were injected with corticosterone (40 mg/kg), the primary glucocorticoid in rodents, or vehicle for 60 days. The CA3 was further subdivided so that the two-thirds of CA3 (nearest the dentate gyrus) previously shown to be vulnerable to corticosterone could be analyzed as two separate subfields. Corticosterone had no effect on neuropil volume or glial volume in the proximal subfield but caused a strong tendency for astrocytic processes to make up a larger proportion of the tissue and for volume of tissue made of constituents other than glial cells (primarily neuronal processes) to be smaller in the middle subfield. Within the neuropil, there were no cellular or subcellular profiles that indicated degeneration, suggesting that corticosterone does not cause prolonged damage. Corticosterone did not reduce cell number or cell or nonperforated synapse size but did cause a pronounced loss of synapses. This loss occurred in both subfields and, therefore, was independent of volume loss. Together, the findings suggest that volume measures can underestimate corticosterone effects on neural structure.

  2. The design of stationary and mobile solid oxide fuel cell-gas turbine systems

    Science.gov (United States)

    Winkler, Wolfgang; Lorenz, Hagen

    A general thermodynamic model has shown that combined fuel cell cycles may reach an electric-efficiency of more than 80%. This value is one of the targets of the Department of Energy (DOE) solid oxide fuel cell-gas turbine (SOFC-GT) program. The combination of a SOFC and GT connects the air flow of the heat engine and the cell cooling. The principle strategy in order to reach high electrical-efficiencies is to avoid a high excess air for the cell cooling and heat losses. Simple combined SOFC-GT cycles show an efficiency between 60 and 72%. The combination of the SOFC and the GT can be done by using an external cooling or by dividing the stack into multiple sub-stacks with a GT behind each sub-stack as the necessary heat sink. The heat exchangers (HEXs) of a system with an external cooling have the benefit of a pressurization on both sides and therefore, have a high heat exchange coefficient. The pressurization on both sides delivers a low stress to the HEX material. The combination of both principles leads to a reheat (RH)-SOFC-GT cycle that can be improved by a steam turbine (ST) cycle. The first results of a study of such a RH-SOFC-GT-ST cycle indicate that a cycle design with an efficiency of more than 80% is possible and confirm the predictions by the theoretical thermodynamic model mentioned above. The extremely short heat-up time of a thin tubular SOFC and the market entrance of the micro-turbines give the option of using these SOFC-GT designs for mobile applications. The possible use of hydrocarbons such as diesel oil is an important benefit of the SOFC. The micro-turbine and the SOFC stack will be matched depending on the start-up requirements of the mobile system. The minimization of the volume needed is a key issue. The efficiency of small GTs is lower than the efficiency of large GTs due to the influence of the leakage within the stages of GTs increasing with a decreasing size of the GT. Thus, the SOFC module pressure must be lower than in larger

  3. Influence of flotation cell volume and solids mass on kinetics of sulfide ore flotation

    OpenAIRE

    Plawski Michal; Bakalarz Alicja

    2016-01-01

    The paper presents studies on the influence of flotation cell capacity and mass of solids in the suspension on the flotation kinetics of sulfide copper ore. A sample of copper ore that was collected from the Polkowice Mine of KGHM Polska Miedz S.A. in Poland was used in the experiments. It was determined that neither the volume of flotation cell nor the mass of solids had influence on the type of kinetics equation of flotation. Copper-bearing minerals floated according to the second-order equ...

  4. Convergence of Cell Based Finite Volume Discretizations for Problems of Control in the Conduction Coefficients

    DEFF Research Database (Denmark)

    Evgrafov, Anton; Gregersen, Misha Marie; Sørensen, Mads Peter

    2011-01-01

    design, in particular shape and topology optimization, and are most often solved numerically utilizing a finite element approach. Within the FV framework for control in the coefficients problems the main difficulty we face is the need to analyze the convergence of fluxes defined on the faces of cells......We present a convergence analysis of a cell-based finite volume (FV) discretization scheme applied to a problem of control in the coefficients of a generalized Laplace equation modelling, for example, a steady state heat conduction. Such problems arise in applications dealing with geometric optimal...

  5. A Gas Cell Based on Hollow-Core Photonic Crystal Fiber (PCF and Its Application for the Detection of Greenhouse Gas (GHG: Nitrous Oxide (N2O

    Directory of Open Access Journals (Sweden)

    Jonas K. Valiunas

    2016-01-01

    Full Text Available The authors report the detection of nitrous oxide gas using intracavity fiber laser absorption spectroscopy. A gas cell based on a hollow-core photonic crystal fiber was constructed and used inside a fiber ring laser cavity as an intracavity gas cell. The fiber laser in the 1.55 μm band was developed using a polarization-maintaining erbium-doped fiber as the gain medium. The wavelength of the laser was selected by a fiber Bragg grating (FBG, and it matches one of the absorption lines of the gas under investigation. The laser wavelength contained multilongitudinal modes, which increases the sensitivity of the detection system. N2O gas has overtones of the fundamental absorption bands and rovibrational transitions in the 1.55 μm band. The system was operated at room temperature and was capable of detecting nitrous oxide gas at sub-ppmv concentration level.

  6. Effect of electromagnetic force and anode gas on electrolyte flow in aluminum electrolysis cell

    Institute of Scientific and Technical Information of China (English)

    ZHOU Nai-jun; XIA Xiao-xia; BAO Sheng-zhong

    2006-01-01

    Based on the commercial computational fluid dynamics software CFX-4.3, electrolyte flow fields in a 156 kA pre-baked anode aluminum electrolysis cell were investigated in three different cases where the electrolyte melt was driven by different kinds of force, i.e. electromagnetic force only, the anode gas drag force only and both of the former two forces. The results show that when electromagnetic force was introduced only, most of the electrolyte moves horizontally; when anode gas drag force was introduced only, the electrolyte flows mainly around each anode with small circulation; when electromagnetic force and anode gas drag force were both introduced together, the structure of the electrolyte flow fields and the velocity of electrolyte are similar to that of the case where only anode gas drag force is used. The electrolyte flow fields are mainly determined by the anode gas drag force.

  7. Life-cycle assessment of diesel, natural gas and hydrogen fuel cell bus transportation systems

    Science.gov (United States)

    Ally, Jamie; Pryor, Trevor

    The Sustainable Transport Energy Programme (STEP) is an initiative of the Government of Western Australia, to explore hydrogen fuel cell technology as an alternative to the existing diesel and natural gas public transit infrastructure in Perth. This project includes three buses manufactured by DaimlerChrysler with Ballard fuel cell power sources operating in regular service alongside the existing natural gas and diesel bus fleets. The life-cycle assessment (LCA) of the fuel cell bus trial in Perth determines the overall environmental footprint and energy demand by studying all phases of the complete transportation system, including the hydrogen infrastructure, bus manufacturing, operation, and end-of-life disposal. The LCAs of the existing diesel and natural gas transportation systems are developed in parallel. The findings show that the trial is competitive with the diesel and natural gas bus systems in terms of global warming potential and eutrophication. Emissions that contribute to acidification and photochemical ozone are greater for the fuel cell buses. Scenario analysis quantifies the improvements that can be expected in future generations of fuel cell vehicles and shows that a reduction of greater than 50% is achievable in the greenhouse gas, photochemical ozone creation and primary energy demand impact categories.

  8. Strong-Coupling Properties of a p-Wave Interacting Fermi Gas on the Viewpoint of Specific Heat at Constant Volume

    Science.gov (United States)

    Inotani, Daisuke; van Wyk, Pieter; Ohashi, Yoji

    2017-02-01

    We theoretically investigate the specific heat CV at constant volume in the normal state of a p-wave interacting Fermi gas. Including fluctuations in the p-wave Cooper channel within the framework of the strong-coupling theory developed by Nozières and Schmitt-Rink, we clarify how CV as a function of temperature varies, as one moves from the weak-coupling regime to the strong-coupling limit. In the weak-coupling regime, CV is shown to be enhanced by p-wave pairing fluctuations, near the superfluid phase transition temperature Tc. Similar enhancement of CV(T ≃ Tc) is also obtained in the strong-coupling regime, which, however, reflects that system is close an ideal Bose gas of p-wave two-body bound molecules. Using these results, we classify the normal state into (1) the normal Fermi gas regime, (2) the p-wave molecular Bose gas regime, and (3) the region between the two, where p-wave pairing fluctuations are dominant. Since the current experiments can only access the normal phase of a p-wave interacting Fermi gas, our results would be useful for experiments to understand strong-coupling properties of this Fermi system above Tc.

  9. Volume regulation of intestinal cells of echinoderms: Putative role of ion transporters (Na(+)/K(+)-ATPase and NKCC).

    Science.gov (United States)

    Castellano, Giovanna C; Souza, Marta M; Freire, Carolina A

    2016-11-01

    Echinoderms are exclusively marine osmoconformer invertebrates. Some species occupy the challenging intertidal region. Upon salinity changes, the extracellular osmotic concentration of these animals also varies, exposing tissues and cells to osmotic challenges. Cells and tissues may then respond with volume regulation mechanisms, which involve transport of ions and water into and/or out of the cells, through ion transporters, such as the Na(+)/K(+)-ATPase and NKCC. The goal of this study was to relate the cell volume regulation capacity of echinoderm intestinal cells Na(+)/K(+)-ATPase and NKCC activities, in three echinoderm species: Holothuria grisea, Arbacia lixula, and Echinometra lucunter. Isolated cells of these species displayed some control of their cell volume upon exposure to anisosmotic media (isolated intestinal cells, calcein fluorescence as indicator of volume change), with a distinct higher capacity shown by H. grisea, which did not swell even upon 50% hyposmotic shock. The holothuroid cells showed indirect evidence (effect of furosemide) of the participation of NKCC in this process, with a secretory function, and of a secondary role by the NKA (effect of ouabain). Other mechanisms are probably responsible for this function in the urchins. Variable expression of these transporters, and others not examined here, may to some extent account for the variability in cell volume regulation capacity in echinoderm cells.

  10. A weakly compressible free-surface flow solver for liquid–gas systems using the volume-of-fluid approach

    CSIR Research Space (South Africa)

    Heyns, Johan A

    2013-05-01

    Full Text Available of the gas has a noteworthy effect on predicted pressure loads in liquid–gas flow in certain instances. With the aim of providing a more accurate numerical representation of dynamic two-fluid flow, the solver is subsequently extended to account for variations...

  11. Improved anode catalysts for coal gas-fueled phosphoric acid fuel cells

    Science.gov (United States)

    Kackley, N. D.; McCatty, S. A.; Kosek, J. A.

    1990-07-01

    The feasibility of adapting phosphoric acid fuel cells to operate on coal gas fuels containing significant levels of contaminants such as CO, H2S and COS was investigated. The overall goal was the development of low-cost, carbon-supported anode fuel cell catalysts that can efficiently operate with a fossil fuel-derived hydrogen gas feed contaminated with carbon monoxide and other impurities. This development would reduce the cost of gas cleanup necessary in a coal gas-fueled PAFC power plant, thereby reducing the final power cost of the electricity produced. The problem to date was that the contaminant gases typically adsorb on catalytic sites and reduce the activity for hydrogen oxidation. An advanced approach investigated was to modify these alloy catalyst systems to operate efficiently on coal gas containing higher levels of contaminants by increasing the alloy catalyst impurity tolerance and ability to extract energy from the CO present through (1) generation of additional hydrogen by promoting the CO/H2 water shift reaction or (2) direct oxidation of CO to CO2 with the same result. For operation on anode gases containing high levels of CO, a Pt-Ti-Zn and Pt-Ti-Ni anode catalyst showed better performance over a Pt baseline or G87A-17-2 catalyst. The ultimate aim was to allow PAFC-based power plants to operate on coal gas fuels containing increased contaminant concentrations, thereby decreasing the need for and cost of rigorous coal gas cleanup procedures.

  12. Processing and characterization of porous electrochemical cells for flue gas purification

    DEFF Research Database (Denmark)

    He, Zeming; Andersen, Kjeld Bøhm; Keel, Li

    2009-01-01

    In the present work, porous electrode materials lanthanum strontium manganate (LSM)-gadolinium-doped cerium oxide (CGO) and electrochemical cells LSM-CGO + CGO were fabricated via the processes of slurry preparation, tape casting and lamination, and sintering. Graphite, wheat starch, and polyamide......, flat, and crack-free electrochemical cells were successfully achieved using the present ceramic processing route. The produced cells could potentially be used for flue gas purification....

  13. Small Cell Lung Cancer: The Influence of Dose and Treatment Volume on Outcome.

    Science.gov (United States)

    Lichter; Turrisi

    1995-01-01

    The treatment of small cell lung cancer is clearly enhanced by the addition of radiation therapy. Survival increases modestly while local thoracic failure as first site of progression is reduced from approximately 60% when chemotherapy alone is used to 30% after combined modality therapy. The variables of radiation dose and treatment volume seem to be important in the successful management of this disease. Local chest control appears to increase as doses are escalated from low levels (25 Gy) to moderate levels (45 to 50 Gy(. With about one third of patients experiencing local chest progression, one can speculate that higher radiation doses might be of value. However, at this time there is no proof that increased dose or dose intensity bears out this promise. Indeed, increasing dose intensity of radiotherapy, eg, twice-daily treatment, increases esophagitis, perhaps reduces local failure, but has not improved overall survival. Using larger total doses or altered fraction schemes must still be considered to be under investigation. To increase dose in a safe manner, reduction in the volume covered by radiation portals will likely need to take place. Modern trials suggest that prophylactic treatment of the radiographically or clinically negative contralateral hilum and/or supraclavicular nodal regions may not be necessary for survival or local control. Importantly, reducing treatment volumes may permit increasing doses without exceding normal tissue tolerance. Also, reduced volumes pave the way for further clinical trials that improve radiation dose delivery by better target definition and more conformal therapy.

  14. Industrial Fuel Gas Demonstration Plant Program. Conceptual design and evaluation of commercial plant. Volume III. Economic analyses (Deliverable Nos. 15 and 16)

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-01-01

    This report presents the results of Task I of Phase I in the form of a Conceptual Design and Evaluation of Commercial Plant report. The report is presented in four volumes as follows: I - Executive Summary, II - Commercial Plant Design, III - Economic Analyses, IV - Demonstration Plant Recommendations. Volume III presents the economic analyses for the commercial plant and the supporting data. General cost and financing factors used in the analyses are tabulated. Three financing modes are considered. The product gas cost calculation procedure is identified and appendices present computer inputs and sample computer outputs for the MLGW, Utility, and Industry Base Cases. The results of the base case cost analyses for plant fenceline gas costs are as follows: Municipal Utility, (e.g. MLGW), $3.76/MM Btu; Investor Owned Utility, (25% equity), $4.48/MM Btu; and Investor Case, (100% equity), $5.21/MM Btu. The results of 47 IFG product cost sensitivity cases involving a dozen sensitivity variables are presented. Plant half size, coal cost, plant investment, and return on equity (industrial) are the most important sensitivity variables. Volume III also presents a summary discussion of the socioeconomic impact of the plant and a discussion of possible commercial incentives for development of IFG plants.

  15. A Reversible Planar Solid Oxide Fuel-Fed Electrolysis Cell and Solid Oxide Fuel Cell for Hydrogen and Electricity Production Operating on Natural Gas/Biomass Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Greg, G.

    2007-03-31

    A solid oxide fuel-assisted electrolysis technique was developed to co-generate hydrogen and electricity directly from a fuel at a reduced cost of electricity. Solid oxide fuel-assisted electrolysis cells (SOFECs), which were comprised of 8YSZ electrolytes sandwiched between thick anode supports and thin cathodes, were constructed and experimentally evaluated at various operation conditions on lab-level button cells with 2 cm2 per-cell active areas as well as on bench-scale stacks with 30 cm2 and 100 cm2 per-cell active areas. To reduce the concentration overpotentials, pore former systems were developed and engineered to optimize the microstructure and morphology of the Ni+8YSZ-based anodes. Chemically stable cathode materials, which possess good electronic and ionic conductivity and exhibit good electrocatalytic properties in both oxidizing and reducing gas atmospheres, were developed and materials properties were investigated. In order to increase the specific hydrogen production rate and thereby reduce the system volume and capital cost for commercial applications, a hybrid system that integrates the technologies of the SOFEC and the solid-oxide fuel cell (SOFC), was developed and successfully demonstrated at a 1kW scale, co-generating hydrogen and electricity directly from chemical fuels.

  16. Real-Time Analysis of Isoprene in Breath by Using Ultraviolet-Absorption Spectroscopy with a Hollow Optical Fiber Gas Cell.

    Science.gov (United States)

    Iwata, Takuro; Katagiri, Takashi; Matsuura, Yuji

    2016-12-05

    A breath analysis system based on ultraviolet-absorption spectroscopy was developed by using a hollow optical fiber as a gas cell for real-time monitoring of isoprene in breath. The hollow optical fiber functions as an ultra-small-volume gas cell with a long path. The measurement sensitivity of the system was evaluated by using nitric-oxide gas as a gas sample. The evaluation result showed that the developed system, using a laser-driven, high-intensity light source and a 3-m-long, aluminum-coated hollow optical fiber, could successfully measure nitric-oxide gas with a 50 ppb concentration. An absorption spectrum of a breath sample in the wavelength region of around 200-300 nm was measured, and the measured spectrum revealed the main absorbing components in breath as water vapor, isoprene, and ozone converted from oxygen by radiation of ultraviolet light. The concentration of isoprene in breath was estimated by multiple linear regression. The regression analysis results showed that the proposed analysis system enables real-time monitoring of isoprene during the exhaling of breath. Accordingly, it is suitable for measuring the circadian variation of isoprene.

  17. A New Gas Cell for High-Precision Doppler Measurements in the Near-Infrared

    CERN Document Server

    Valdivielso, L; Martín, E

    2010-01-01

    High-resolution spectroscopy in the near-infrared could become the leading method for discovering extra-solar planets around very low-mass stars and brown dwarfs. To help to achieve an accuracy of ~m/s, we are developing a gas cell which consists of a mixture of gases whose absorption spectral lines span all over the near-infrared region. We present the most promising mixture, made of acetylene, nitrous oxide, ammonia, chloromethans and hydrocarbons. The mixture is contained in a small size 13 cm long gas cell and covers most of the H and K-bands. It also shows small absorptions in the J-band but they are few and not sharp enough for near infrared wavelength calibration. We describe the working method and experiments and compare our results with the state of the art for near infrared gas cells.

  18. Experimental study and comparison of various designs of gas flow fields to PEM fuel cells and cell stack performance

    Directory of Open Access Journals (Sweden)

    Hong eLiu

    2014-01-01

    Full Text Available In this study, a significant number of experimental tests to PEM fuel cells were conducted to investigate the effect of gas flow fields on fuel cell performance. Graphite plates with various flow field or flow channel designs, from literature survey and also novel designs by the authors, were used for the PEM fuel cell assembly. The fabricated fuel cells all have an effective membrane area of 23.5 cm2. The results showed that the serpentine flow channel design is still favorable, giving the best single fuel cell performance amongst all the studied flow channel designs. A novel symmetric serpentine flow field was proposed for relatively large size fuel cell application. Four fuel cell stacks each including four cells were assembled using different designs of serpentine flow channels. The output power performances of fuel cell stacks were compared and the novel symmetric serpentine flow field design is recommended for its very good performance.

  19. Impaired Cell Volume Regulation in Intestinal Crypt Epithelia of Cystic Fibrosis Mice

    Science.gov (United States)

    Valverde, M. A.; O'Brien, J. A.; Sepulveda, F. V.; Ratcliff, R. A.; Evans, M. J.; Colledge, W. H.

    1995-09-01

    Cystic fibrosis is a disease characterized by abnormalities in the epithelia of the lungs, intestine, salivary and sweat glands, liver, and reproductive systems, often as a result of inadequate hydration of their secretions. The primary defect in cystic fibrosis is the altered activity of a cAMP-activated Cl^- channel, the cystic fibrosis transmembrane conductance regulator (CFTR) channel. However, it is not clear how a defect in the CFTR Cl^- channel function leads to the observed pathological changes. Although much is known about the structural properties and regulation of the CFTR, little is known of its relationship to cellular functions other than the cAMP-dependent Cl^- secretion. Here we report that cell volume regulation after hypotonic challenge is also defective in intestinal crypt epithelial cells isolated from CFTR -/- mutant mice. Moreover, the impairment of the regulatory volume decrease in CFTR -/- crypts appears to be related to the inability of a K^+ conductance to provide a pathway for the exit of this cation during the volume adjustments. This provides evidence that the lack of CFTR protein may have additional consequences for the cellular function other than the abnormal cAMP-mediated Cl^- secretion.

  20. Continuous gas fermentation by Acetobacterium woodii in a submerged membrane reactor with full cell retention.

    Science.gov (United States)

    Kantzow, Christina; Mayer, Alexander; Weuster-Botz, Dirk

    2015-10-20

    Acetogenic bacteria like Acetobacterium woodii represent an ancient group of anaerobic microorganisms which use hydrogen and carbon dioxide to produce acetate. Cell concentrations and space-time yields are usually low in gas fermentations. A standard stirred‑tank bioreactor with continuous gas supply was equipped with a customized submerged microfiltration unit. A. woodii showed similar growth behavior with an initial maximal growth rate of 1.2 d(-1) in continuous gas fermentations with full cell retention and varying dilution rates. A steady increase of cell mass concentrations was observed with the highest biomass formation at the highest dilution rate. By contrast the final acetate concentrations were lowest at the highest dilution rate. The highest final acetate space-time yield of 148 g l(-1) d(-1) was measured at the highest dilution rate (increase by factor 8 compared to a standard batch process or by factor 37 compared to published data). The highest reported cell concentration of A. woodii in gas fermentations of nearly 14 g l(-1) cell dry weight was achieved in the submerged membrane bioreactor with increased yeast extract concentrations in the feed medium. Product inhibition was observed when acetate concentrations exceeded 8-12 g l(-1) causing a steady decrease in cell mass specific acetate production rates.

  1. A large volume cell for in situ neutron diffraction studies of hydrothermal crystallizations

    Science.gov (United States)

    Xia, Fang; Qian, Gujie; Brugger, Joël; Studer, Andrew; Olsen, Scott; Pring, Allan

    2010-10-01

    A hydrothermal cell with 320 ml internal volume has been designed and constructed for in situ neutron diffraction studies of hydrothermal crystallizations. The cell design adopts a dumbbell configuration assembled with standard commercial stainless steel components and a zero-scattering Ti-Zr alloy sample compartment. The fluid movement and heat transfer are simply driven by natural convection due to the natural temperature gradient along the fluid path, so that the temperature at the sample compartment can be stably sustained by heating the fluid in the bottom fluid reservoir. The cell can operate at temperatures up to 300 °C and pressures up to 90 bars and is suitable for studying reactions requiring a large volume of hydrothermal fluid to damp out the negative effect from the change of fluid composition during the course of the reactions. The capability of the cell was demonstrated by a hydrothermal phase transformation investigation from leucite (KAlSi2O6) to analcime (NaAlSi2O6ṡH2O) at 210 °C on the high intensity powder diffractometer Wombat in ANSTO. The kinetics of the transformation has been resolved by collecting diffraction patterns every 10 min followed by Rietveld quantitative phase analysis. The classical Avrami/Arrhenius analysis gives an activation energy of 82.3±1.1 kJ mol-1. Estimations of the reaction rate under natural environments by extrapolations agree well with petrological observations.

  2. Advanced gas-emission anode design for microfluidic fuel cell eliminating bubble accumulation

    Science.gov (United States)

    Zhang, Hao; Xuan, Jin; Leung, Dennis Y. C.; Wang, Huizhi; Xu, Hong; Zhang, Li

    2017-10-01

    A microfluidic fuel cell is a low cost, easily fabricated energy device and is considered a promising energy supplier for portable electronics. However, the currently developed microfluidic fuel cells that are fed with hydrocarbon fuels are confronted with a bubble problem especially when operating at high current density conditions. In this work, a gas-emission anode is presented to eliminate the gas accumulation at the anode. This gas-emission anode is verified as a valid design for discharging gaseous products, which is especially beneficial for stable operation of microfluidic fuel cells. The electrochemical performance of a counter-flow microfluidic fuel cell equipped with a gas-emission anode was measured. The results indicate that the specific design of the gas-emission anode is essential for reducing the oxygen reduction reaction parasitic effect at the anode. Fuel utilization of 76.4% was achieved at a flow rate of 0.35 µl min‑1. Current–voltage curves of single electrodes were measured and the parasitic effect at the anode was identified as the main performance limiting factor in the presented anode design.

  3. Development of a resonant laser ionization gas cell for high-energy, short-lived nuclei

    CERN Document Server

    Sonoda, T; Tomita, H; Sakamoto, C; Takatsuka, T; Furukawa, T; Iimura, H; Ito, Y; Kubo, T; Matsuo, Y; Mita, H; Naimi, S; Nakamura, S; Noto, T; Schury, P; Shinozuka, T; Wakui, T; Miyatake, H; Jeong, S; Ishiyama, H; Watanabe, Y X; Hirayama, Y; Okada, K; Takamine, A

    2012-01-01

    A new laser ion source configuration based on resonant photoionization in a gas cell has been developed at RIBF RIKEN. This system is intended for the future PArasitic RI-beam production by Laser Ion-Source (PALIS) project which will be installed at RIKEN's fragment separator, BigRIPS. A novel implementation of differential pumping, in combination with a sextupole ion beam guide (SPIG), has been developed. A few small scroll pumps create a pressure difference from 1000 hPa - 10^-3 Pa within a geometry drastically miniaturized compared to conventional systems. This system can utilize a large exit hole for fast evacuation times, minimizing the decay loss for short-lived nuclei during extraction from a buffer gas cell, while sufficient gas cell pressure is maintained for stopping high energy RI-beams. In spite of the motion in a dense pressure gradient, the photo-ionized ions inside the gas cell are ejected with an assisting force gas jet and successfully transported to a high-vacuum region via SPIG followed by ...

  4. Special considerations on operating a fuel cell power plant using natural gas with marginal heating value

    Energy Technology Data Exchange (ETDEWEB)

    Moses, L. Ng; Chien-Liang Lin [Industrial Technology Research Institute, Taiwan (China); Ya-Tang Cheng [Power Research Institute, Taiwan (China)

    1996-12-31

    In realizing new power generation technologies in Taiwan, a phosphoric acid fuel cell power plant (model PC2513, ONSI Corporation) has been installed in the premises of the Power Research Institute of the Taiwan Power Company in Taipei County of Taiwan. The pipeline gas supplying to the site of this power plant has a high percentage of carbon dioxide and thus a slightly lower heating value than that specified by the manufacturer. Because of the lowering of heating value of input gas, the highest Output power from the power plant is understandably less than the rated power of 200 kW designed. Further, the transient response of the power plant as interrupted from the Grid is also affected. Since this gas is also the pipeline gas supplying to the heavily populated Taipei Municipal area, it is conceivable that the success of the operations of fuel cells using this fuel is of vital importance to the promotion of the use of this power generation technology in Taiwan. Hence, experiments were set up to assess the feasibility of this fuel cell power plant using the existing pipeline gas in this part of Taiwan where fuel cells would most likely find useful.

  5. Effect of radiologic contrast material on cell volume regulation in proximal renal tubules from trout (Salmo trutta).

    Science.gov (United States)

    Galtung, H K; Løken, M; Sakariassen, K S

    2000-11-01

    Most radiographic contrast media (CM) are hyperosmotic and pose an osmotic threat to cells they are in contact with. To study these effects at the cellular level, cell volume regulatory mechanisms were observed in proximal renal tubules following exposure to the CM iohexol, ioxaglate, and iodixanol. Isolated renal tubules from trout (Salmo trutta) were exposed to 5% vol/vol iohexol (326 mOsm), ioxaglate (314 mOsm), or iodixanol (300 mOsm) or mannitol (to achieve the same osmolalities), and cell volume changes were observed videometrically. Iohexol and ioxaglate solutions induced a rapid shrinkage (12%-13%) not followed by cell volume regulation. Without CM (same osmolality), the cells shrank 11% but then showed a 77%-88% volume recovery. This reswelling was inhibited by 55% with the Na+, K+, Cl- symporter inhibitor bumetanide (50 micromol/L). Iodixanol did not significantly affect cell volume. Tubules preincubated with CM or mannitol were then stimulated with a hypoosmotic Ringer solution (160 mOsm) resulting in a 26%-36% cellular volume increase. Compared with results of experiments without mannitol and CM, preexposure to iohexol or ioxaglate almost completely inhibited the expected regulatory shrinkage phase, while previous exposure to hyperosmotic solutions with mannitol reduced the shrinkage response by 40%-53%. In this system, the hyperosmotic iohexol and ioxaglate cause cell shrinkage followed by an impaired cell volume regulatory response. Exposure to these two CM also inhibits cell volume regulation on hypoosmotic stimulation. The isosmotic iodixanol has no such effects. These changes appear to some extent to be a result of the CM's degree of hyperosmolality, but this property alone does not explain these findings.

  6. [Verification of complete blood cell count (CBC) data from heparinized blood gas samples].

    Science.gov (United States)

    Sakoguchi, Takafumi; Fujii, Seiji; Inuzumi, Koji; Kaminoh, Yoshiroh; Hirose, Munetaka; Masaki, Mitsuru; Koshiba, Masahiro

    2014-02-01

    Complete blood cell count (CBC) data from heparinized blood gas (H-Gas) samples were verified with primary focus on the platelet count (PLT). When a part of H-Gas sample was taken to a separation tube from the blood collection syringe and CBC of the sample in the separation tube was repeatedly measured (Procedure 1), the PLT from 5 samples relative to that obtained immediately after the separation was gradually reduced to 72.6-94.2% during serial measurements (every 5 minutes, up to 30 minutes). The change in the scattergram pattern suggested that this PLT decrease was due to the formation of platelet clumps. The white blood cell count (WBC), red blood cell count (RBC), hemoglobin (Hb) and hematocrit (Ht) values did not significantly change during the repeated measurements. On the other hand, PLT was significantly improved to 96.8-99.8% when the H-Gas sample was kept in the blood collection syringe so as to minimizing the exposure to the air, and the sample for the measurement from H-Gas was taken every time to separation tube from the syringe, followed by CBC measurement without delay (Procedure 2). In addition, while there were significant variations (CV: 11.8-18.2%) in PLT reproducibility among H-Gas samples by Procedure 1, measurements utilizing the Procedure 2 resulted in much smaller variations (CV: 2.2-3.7%). Thus the CBC data obtained from H-Gas samples were equivalent to those from EDTA samples when the Procedure 2 was applied. These data suggest that H-Gas samples can be used for the accurate CBC measurement, including PLT, by applying the Procedure 2.

  7. Development of a Solid Oxide Fuel Cell for the utilization of coal mine gas

    Science.gov (United States)

    Groß, B.; Blum, L.; de Haart, L. G. J.; Dengel, A.

    Apart from natural gas there is another important natural source of methane. The so-called coal mine gas is a by-product of the geochemical process of the carbonization of sediments from marsh woods of the Earth's Carboniferous Period. Methane evaporates from the coal and has to be removed out of the active mines where it represents one of the main safety risks. Methane also evaporates in abandoned coal mines. In the federal state Saarland in Germany exists above ground a more than 110 km pipeline for the drained coal mine gas from 12 different sources. The content of methane varies between 25 and 90%, the oxygen content (from air) is in the range up to 10%. This wide range or variation, respectively, of fuel and oxygen content, causes a lot of problems for the use in conventional engines. Therefore the company Evonik New Energies GmbH is interested in using SOFC with coal mine gas as efficient as possible to produce electric power. For that purpose at Forschungszentrum Jülich the available SOFC technology was adapted to the use with coal mine gas and a test facility was designed to operate an SOFC stack (approximately 2 kW electrical power output) together with a pre-reformer. This paper presents the results of the coal mine gas analysis and the effect on the pre-reformer and the fuel cell. The composition of the coal mine gas was determined by means of micro-gas chromatography. The results obtained from preliminary tests using synthetic and real coal mine gas on the pre-reformer and on the fuel cell are discussed.

  8. Gas detection with microelectromechanical Fabry-Perot interferometer technology in cell phone

    Science.gov (United States)

    Mannila, Rami; Hyypiö, Risto; Korkalainen, Marko; Blomberg, Martti; Kattelus, Hannu; Rissanen, Anna

    2015-06-01

    VTT Technical Research Centre of Finland has developed a miniaturized optical sensor for gas detection in a cell phone. The sensor is based on a microelectromechanical (MEMS) Fabry-Perot interferometer, which is a structure with two highly reflective surfaces separated by a tunable air gap. The MEMS FPI is a monolithic device, i.e. it is made entirely on one substrate in a batch process, without assembling separate pieces together. The gap is adjusted by moving the upper mirror with electrostatic force, so there are no actual moving parts. VTT has designed and manufactured a MEMS FPI based carbon dioxide sensor demonstrator which is integrated to a cell phone shield cover. The demonstrator contains light source, gas cell, MEMS FPI, detector, control electronics and two coin cell batteries as a power source. It is connected to the cell phone by Bluetooth. By adjusting the wavelength range and customizing the MEMS FPI structure, it is possible to selectively sense multiple gases.

  9. Turbomachinery for the air management and energy recovery in fuel cell gas turbine hybrid systems

    Energy Technology Data Exchange (ETDEWEB)

    Traverso, A.; Magistri, L.; Massardo, A.F. [DIMSET (TPG), University of Genoa, Via Montallegro 1, 16145, Genoa (Italy)

    2010-02-15

    High temperature fuel cells (MCFCs and SOFCs) can operate at atmospheric or pressurised conditions. In both cases, system performance can be significantly improved when the fuel cells are integrated with proper devices, which are designed to provide the necessary air inlet conditions and to recover the exhaust gas energy. This paper presents a review of modelling and design issues for the integration of turbomachinery with the fuel cell system, because turbomachinery is the most promising technology for coping with the high temperature fuel cell requirements. Since the gas turbine expander performance is significantly influenced by exhausts compositions, analytical approach is undertaken for properly modelling composition influence on expander performance, and results are presented to demonstrate the quantitative influence of the system parameters on the performance. The analysis covers the three main aspects of performance evaluation: the on-design, the off-design and, as a final mention, the control of the fuel cell hybrid systems. (author)

  10. Integration of A Solid Oxide Fuel Cell into A 10 MW Gas Turbine Power Plant

    Directory of Open Access Journals (Sweden)

    Denver F. Cheddie

    2010-04-01

    Full Text Available Power generation using gas turbine power plants operating on the Brayton cycle suffers from low efficiencies. In this work, a solid oxide fuel cell (SOFC is proposed for integration into a 10 MW gas turbine power plant, operating at 30% efficiency. The SOFC system utilizes four heat exchangers for heat recovery from both the turbine outlet and the fuel cell outlet to ensure a sufficiently high SOFC temperature. The power output of the hybrid plant is 37 MW at 66.2% efficiency. A thermo-economic model predicts a payback period of less than four years, based on future projected SOFC cost estimates.

  11. Thermodynamic Performance Study of Biomass Gasification, Solid Oxide Fuel Cell and Micro Gas Turbine Hybrid Systems

    DEFF Research Database (Denmark)

    Bang-Møller, Christian; Rokni, Masoud

    2010-01-01

    A system level modelling study of three combined heat and power systems based on biomass gasification is presented. Product gas is converted in a micro gas turbine (MGT) in the first system, in a solid oxide fuel cell (SOFC) in the second system and in a combined SOFC–MGT arrangement in the third...... system. An electrochemical model of the SOFC has been developed and calibrated against published data from Topsoe Fuel Cells A/S and the Risø National Laboratory. The modelled gasifier is based on an up scaled version (~500 kW_th) of the demonstrated low tar gasifier, Viking, situated at the Technical...

  12. Condition-dependent cell volume and concentration of Escherichia coli to facilitate data conversion for systems biology modeling

    NARCIS (Netherlands)

    Volkmer, Benjamin; Heinemann, Matthias

    2011-01-01

    Systems biology modeling typically requires quantitative experimental data such as intracellular concentrations or copy numbers per cell. In order to convert population-averaging omics measurement data to intracellular concentrations or cellular copy numbers, the total cell volume and number of cell

  13. Robust high-performance nanoliter-volume single-cell multiple displacement amplification on planar substrates

    Science.gov (United States)

    Leung, Kaston; Klaus, Anders; Lin, Bill K.; Laks, Emma; Biele, Justina; Lai, Daniel; Bashashati, Ali; Huang, Yi-Fei; Aniba, Radhouane; Moksa, Michelle; Steif, Adi; Mes-Masson, Anne-Marie; Hirst, Martin; Shah, Sohrab P.; Aparicio, Samuel; Hansen, Carl L.

    2016-01-01

    The genomes of large numbers of single cells must be sequenced to further understanding of the biological significance of genomic heterogeneity in complex systems. Whole genome amplification (WGA) of single cells is generally the first step in such studies, but is prone to nonuniformity that can compromise genomic measurement accuracy. Despite recent advances, robust performance in high-throughput single-cell WGA remains elusive. Here, we introduce droplet multiple displacement amplification (MDA), a method that uses commercially available liquid dispensing to perform high-throughput single-cell MDA in nanoliter volumes. The performance of droplet MDA is characterized using a large dataset of 129 normal diploid cells, and is shown to exceed previously reported single-cell WGA methods in amplification uniformity, genome coverage, and/or robustness. We achieve up to 80% coverage of a single-cell genome at 5× sequencing depth, and demonstrate excellent single-nucleotide variant (SNV) detection using targeted sequencing of droplet MDA product to achieve a median allelic dropout of 15%, and using whole genome sequencing to achieve false and true positive rates of 9.66 × 10−6 and 68.8%, respectively, in a G1-phase cell. We further show that droplet MDA allows for the detection of copy number variants (CNVs) as small as 30 kb in single cells of an ovarian cancer cell line and as small as 9 Mb in two high-grade serous ovarian cancer samples using only 0.02× depth. Droplet MDA provides an accessible and scalable method for performing robust and accurate CNV and SNV measurements on large numbers of single cells. PMID:27412862

  14. Large volume of water samples introduced in dispersive liquid-liquid microextraction for the determination of 15 triazole fungicides by gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Nie, Jing; Chen, Fujiang; Song, Zhiyu; Sun, Caixia; Li, Zuguang; Liu, Wenhan; Lee, Mawrong

    2016-10-01

    A novel method of large volume of water samples directly introduced in dispersive liquid-liquid microextraction was developed, which is based on ultrasound/manual shaking-synergy-assisted emulsification and self-generating carbon dioxide gas (CO2) breaking down the emulsion for the determination of 15 triazole fungicides by gas chromatography-tandem mass spectrometry. This technique makes low-density extraction solvent toluene (180 μL) dissolve in 200 mL of samples containing 0.05 mol L(-1) of HCl and 5 % of NaCl (w/v) to form a well emulsion by synergy of ultrasound and manual shaking, and injects NaHCO3 solution (1.0 mol L(-1)) to generate CO2 achieving phase separation with the assistance of ultrasound. The entire process is accomplished within 8 min. The injection of NaHCO3 to generate CO2 achieves phase separation that breaks through the centrifugation limited large volume aqueous samples. In addition, the device could be easily cleaned, and this kind of vessel could be reconfigured for any volume of samples. Under optimal conditions, the low limits of detection ranging from 0.7 to 51.7 ng L(-1), wide linearity, and enrichment factors obtained were in the range 924-3669 for different triazole fungicides. Southern end of the Beijing-Hangzhou Grand Canal water (Hangzhou, China) was used to verify the applicability of the developed method. Graphical Abstract Flow chart of ultrasound/manual shaking-synergy-assisted emulsification and self-generating carbon dioxide gas breaking down the emulsion.

  15. Evaluated kinetic and photochemical data for atmospheric chemistry: Volume IV ? gas phase reactions of organic halogen species

    OpenAIRE

    2007-01-01

    International audience; This article, the fourth in the series, presents kinetic and photochemical data sheets evaluated by the IUPAC Subcommittee on Gas Kinetic Data Evaluation for Atmospheric Chemistry. It covers the gas phase and photochemical reactions of organic halogen species, which were last published in 1997, and were updated on the IUPAC website in 2006. The article consists of a summary sheet, containing the recommended kinetic parameters for the evaluated reactions, and four appen...

  16. Evaluated kinetic and photochemical data for atmospheric chemistry: Volume II – gas phase reactions of organic species

    OpenAIRE

    2006-01-01

    This article, the second in the series, presents kinetic and photochemical data evaluated by the IUPAC Subcommittee on Gas Kinetic Data Evaluation for Atmospheric Chemistry. It covers the gas phase and photochemical reactions of Organic species, which were last published in 1999, and were updated on the IUPAC website in late 2002, and subsequently during the preparation of this article. The article consists of a summary table of the recommended rate coefficients, containing the...

  17. Evaluated kinetic and photochemical data for atmospheric chemistry: Volume I - gas phase reactions of Ox, HOx, NOx and SOx species

    OpenAIRE

    2004-01-01

    This article, the first in the series, presents kinetic and photochemical data evaluated by the IUPAC Subcommittee on GasKinetic Data Evaluation for Atmospheric Chemistry. It covers the gas phase and photochemical reactions of Ox, HOx, NOx and SOx species, which were last published in 1997, and were updated on the IUPAC website in late 2001. The article consists of a summary sheet, containing the recommended kinetic parameters for the evaluated reactions, and five appendi...

  18. [Interpretation and use of routine pulmonary function tests: Spirometry, static lung volumes, lung diffusion, arterial blood gas, methacholine challenge test and 6-minute walk test].

    Science.gov (United States)

    Bokov, P; Delclaux, C

    2016-02-01

    Resting pulmonary function tests (PFT) include the assessment of ventilatory capacity: spirometry (forced expiratory flows and mobilisable volumes) and static volume assessment, notably using body plethysmography. Spirometry allows the potential definition of obstructive defect, while static volume assessment allows the potential definition of restrictive defect (decrease in total lung capacity) and thoracic hyperinflation (increase in static volumes). It must be kept in mind that this evaluation is incomplete and that an assessment of ventilatory demand is often warranted, especially when facing dyspnoea: evaluation of arterial blood gas (searching for respiratory insufficiency) and measurement of the transfer coefficient of the lung, allowing with the measurement of alveolar volume to calculate the diffusing capacity of the lung for CO (DLCO: assessment of alveolar-capillary wall and capillary blood volume). All these pulmonary function tests have been the subject of an Americano-European Task force (standardisation of lung function testing) published in 2005, and translated in French in 2007. Interpretative strategies for lung function tests have been recommended, which define abnormal lung function tests using the 5th and 95th percentiles of predicted values (lower and upper limits of normal values). Thus, these recommendations need to be implemented in all pulmonary function test units. A methacholine challenge test will only be performed in the presence of an intermediate pre-test probability for asthma (diagnostic uncertainty), which is an infrequent setting. The most convenient exertional test is the 6-minute walk test that allows the assessment of walking performance, the search for arterial desaturation and the quantification of dyspnoea complaint.

  19. A Volume-Weighting Cloud-in-Cell Model for Particle Simulation of Axially Symmetric Plasmas

    Institute of Scientific and Technical Information of China (English)

    李永东; 何锋; 刘纯亮

    2005-01-01

    A volume-weighting cloud-in-cell (VW-CIC) model is developed to implement the particle-in-cell (PIC) simulation in axially symmetric systems. This model gives a first-order accuracy in the cylindrical system, and it is incorporated into a PIC code. A planar diode with a finite-radius circular emitter is simulated with the code. The simulation results show that the VW-CIC model has a better accuracy and a lower noise than the conventional area-weighting cloud-in-cell (AW-CIC) model, especially on those points near the axis. The two-dimensional (2-D) space-charge-limited current density obtained from VW-CIC model is in better agreement with Lau's analytical result. This model is more suitable for 2.5-D PIC simulation of axially symmetric plasmas.

  20. Inhibition of volume-activated chloride currents in endothelial cells by chromones.

    Science.gov (United States)

    Heinke, S.; Szücs, G.; Norris, A.; Droogmans, G.; Nilius, B.

    1995-01-01

    1. We have studied the effects of the reported chloride channel blocker, sodium cromoglycate, on volume-activated Cl- currents in endothelial cells from bovine pulmonary artery by means of the whole-cell patch clamp technique. Cl- currents were activated by challenging the cells with a hypotonic extracellular solution of 60% of the normal osmolarity. 2. Half maximal activation of the current at +95 mV occurred after exposure of the cells for 148 +/- 10 s (n = 6) to hypotonic solution (HTS). At the same membrane potential but in the presence of 100 microM sodium cromoglycate (disodium-1,3-bis (2'-carboxylate-chromone-5'-yloxy)-2-hydroxy-propane) activation was delayed (253 +/- 25 s, n = 6) and the maximal current amplitude was reduced to 63 +/- 7% of the control (n = 13). 3. In comparison, an equimolar concentration of NPPB (5-nitro-2(3-phenyl) propylamino-benzoic acid), another Cl- channel blocker, completely blocked the volume-activated current in less than 20 s. 4. Sodium cromoglycate, applied at the time when the HTS-induced current was completely activated, dose-dependently inhibited this current with a concentration for half maximal inhibition of 310 +/- 70 microM. Data for nedocromil sodium were not significantly different from those for sodium cromoglycate. 5. Sodium cromoglycate, loaded into the endothelial cells via the patch pipette in ruptured patches, resulted in a decline of the HTS activated current with a time course that was compatible with diffusion of the compound from the pipette into the cell.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8564197

  1. System for exposing cultured cells to intermittent hypoxia utilizing gas permeable cultureware.

    Science.gov (United States)

    Polak, Jan; Studer-Rabeler, Karen; McHugh, Holly; Hussain, Mehboob A; Shimoda, Larissa A

    2015-07-01

    Tissue intermittent hypoxia (IH) occurs in obstructive sleep apnea, sickle cell anemia, physical exercise and other conditions. Poor gas solubility and slow diffusion through culture media hampers mimicking IH-induced transitions of O(2) in vitro. We aimed to develop a system enabling exposure of cultured cells to IH and to validate such exposure by real-time O(2) measurements and cellular responses. Standard 24-well culture plates and plates with bottoms made from a gas permeable film were placed in a heated cabinet. Desired cycling of O(2) levels was induced using programmable solenoids to purge mixtures of 95% N(2) + 5% CO(2) or 95% O(2) + 5% CO(2). Dissolved oxygen, gas pressure, temperature, and water evaporation were measured during cycling. IH-induced cellular effects were evaluated by hypoxia inducible factor (HIF) and NF-κB luciferase reporters in HEK296 cells and by insulin secretion in rat insulinoma cells. Oxygen cycling in the cabinet was translated into identical changes of O(2) at the well bottom in gas permeable, but not in standard cultureware. Twenty-four hours of IH exposure increased HIF (112%), NF-κB (111%) and insulin secretion (44%). Described system enables reproducible and prolonged IH exposure in cultured cells while controlling for important environmental factors.

  2. A High Temperature Polymer Electrolyte Membrane Fuel Cell Model for Reformate Gas

    Directory of Open Access Journals (Sweden)

    M. Mamlouk

    2011-01-01

    Full Text Available A one-dimensional model of a high temperature polymer electrolyte membrane fuel cell using polybenzimidazole (PBI membranes is described. The model considers mass transport through a thin film electrolyte covering the catalyst particles as well as through the porous media. The incorporation of a thin film model describing reactant gas mass transport through electrolyte covering the electrocatalyst is shown to be an essential requirement for accurate simulation. The catalyst interface is represented using a macrohomogeneous model. The influence of carbon monoxide, carbon dioxide, and methane, which would be present in a reformate gas, is considered in terms of the effect on the anode polarisation/kinetics behaviour. The model simulates the influence of operating conditions, cell parameters, and fuel gas compositions on the cell voltage current density characteristics. The model gives good predictions of the effect of oxygen and air pressures on cell behaviour and correctly simulates the mass transport behaviour of the cell. The model with reformate gas shows that additional voltage losses associated with CO poisoning can lead to loss in voltage of tens of mV and thus reduction in power.

  3. Differential Effects of Endotracheal Suctioning on Gas Exchanges in Patients with Acute Respiratory Failure under Pressure-Controlled and Volume-Controlled Ventilation

    Directory of Open Access Journals (Sweden)

    Xiao-Wei Liu

    2015-01-01

    Full Text Available This study was conducted to evaluate the effects of open endotracheal suctioning on gas exchange and respiratory mechanics in ARF patients under the modes of PCV or VCV. Ninety-six ARF patients were treated with open endotracheal suctioning and their variations in respiratory mechanics and gas exchange after the suctions were compared. Under PCV mode, compared with the initial level of tidal volume (VT, ARF patients showed 30.0% and 27.8% decrease at 1 min and 10 min, respectively. Furthermore, the initial respiratory system compliance (Crs decreased by 29.6% and 28.5% at 1 min and 10 min, respectively. Under VCV mode, compared with the initial level, 38.6% and 37.5% increase in peak airway pressure (PAP were found at 1 min and 10 min, respectively. Under PCV mode, the initial PaO2 increased by 6.4% and 10.2 % at 3 min and 10 min, respectively, while 18.9% and 30.6% increase of the initial PaO2 were observed under VCV mode. Summarily, endotracheal suctioning may impair gas exchange and decrease lung compliance in ARF patients receiving mechanical ventilation under both PCV and VCV modes, but endotracheal suctioning effects on gas exchange were more severe and longer-lasting under PCV mode than VCV.

  4. Long noncoding RNA GAS5 inhibits malignant proliferation and chemotherapy resistance to doxorubicin in bladder transitional cell carcinoma.

    Science.gov (United States)

    Zhang, Hui; Guo, Yan; Song, Yongsheng; Shang, Chao

    2017-01-01

    Bladder cancer is the most general malignant cancer in genitourinary system, more than 90% of BCs are bladder transitional cell carcinomas (BTCC). This study aimed to investigate the clinical significance of growth arrest-specific 5 (GAS5) gene and its regulatory effects of malignant proliferation and chemotherapy resistance to doxorubicin in BTCC cells. The expression of GAS5 was detected by quantitative real-time PCR. Statistical analysis was used to determine the relationship between GAS5 expression and clinical features and the prognostic value of GAS5 for disease free survival. MTT assay was used to detect cell proliferation ability and chemosensitivity. Dual-color flow cytometric method was used to detect cell apoptosis. The expression of Bcl-2 protein was examined by western blot. In this study, we found that GAS5 low-expressed in BTCC tissues and cells, and its low expression level had positive correlation with higher pathological grades of BTCC. Moreover, GAS5 was a prognostic biomarker of disease free survival for BTCC patients. GAS5 over-expression could inhibit cell proliferation of BTCC J82 and T24 cells significantly. The IC50 to doxorubicin in T24/DOX cells (resistance to doxorubicin) presented a conspicuous depression, GAS5 enhancement reduced the chemotherapy resistance to doxorubicin. GAS5 over-expression promoted apoptosis induced by doxorubicin in T24/DOX cells, and depressed the expression of anti-apoptosis protein Bcl-2. The results indicated that GAS5 regulated the chemotherapy resistance to doxorubicin via Bcl2 partly. In summary, lncRNA GAS5 was a prognostic biomarker of disease free survival in BTCC patients, and acted as a tumor-suppressing gene to inhibit malignant proliferation and resistance to doxorubicin in BTCC cells. LncRNA GAS5 might be a novel potential therapeutic target for BTCC.

  5. Cell volume control in phospholemman (PLM) knockout mice: do cardiac myocytes demonstrate a regulatory volume decrease and is this influenced by deletion of PLM?

    Science.gov (United States)

    Bell, James R; Lloyd, David; Curl, Claire L; Delbridge, Lea M D; Shattock, Michael J

    2009-03-01

    In addition to modulatory actions on Na+-K+-ATPase, phospholemman (PLM) has been proposed to play a role in cell volume regulation. Overexpression of PLM induces ionic conductances, with 'PLM channels' exhibiting selectivity for taurine. Osmotic challenge of host cells overexpressing PLM increases taurine efflux and augments the cellular regulatory volume decrease (RVD) response, though a link between PLM and cell volume regulation has not been studied in the heart. We recently reported a depressed cardiac contractile function in PLM knockout mice in vivo, which was exacerbated in crystalloid-perfused isolated hearts, indicating that these hearts were osmotically challenged. To address this, the present study investigated the role of PLM in osmoregulation in the heart. Isolated PLM wild-type and knockout hearts were perfused with a crystalloid buffer supplemented with mannitol in a bid to prevent perfusate-induced cell swelling and maintain function. Accordingly, and in contrast to wild-type control hearts, contractile function was improved in PLM knockout hearts with 30 mM mannitol. To investigate further, isolated PLM wild-type and knockout cardiomyocytes were subjected to increasing hyposmotic challenges. Initial validation studies showed the IonOptix video edge-detection system to be a simple and accurate 'real-time' method for tracking cell width as a marker of cell size. Myocytes swelled equally in both genotypes, indicating that PLM, when expressed at physiological levels in cardiomyocytes, is not essential to limit water accumulation in response to a hyposmotic challenge. Interestingly, freshly isolated adult cardiomyocytes consistently failed to mount RVDs in response to cell swelling, adding to conflicting reports in the literature. A proposed perturbation of the RVD response as a result of the cell isolation process was not restored, however, with short-term culture in either adult or neonatal cardiomyocytes.

  6. Experimental Study and Comparison of Various Designs of Gas Flow Fields to PEM Fuel Cells and Cell Stack Performance

    OpenAIRE

    Liu, Hong; Li, Peiwen; Juarez-Robles, Daniel; Wang, Kai; Hernandez-Guerrero, Abel

    2014-01-01

    In this study, a significant number of experimental tests to proton exchange membrane (PEM) fuel cells were conducted to investigate the effect of gas flow fields on fuel cell performance. Graphite plates with various flow field or flow channel designs, from literature survey and also novel designs by the authors, were used for the PEM fuel cell assembly. The fabricated fuel cells have an effective membrane area of 23.5 cm2. The results showed that the serpentine flow channel design is still ...

  7. Experimental study and comparison of various designs of gas flow fields to PEM fuel cells and cell stack performance

    OpenAIRE

    Hong eLiu; Peiwen eLi; Daniel eJuarez-Robles; Kai eWang; Abel eHernandez-Guerrero

    2014-01-01

    In this study, a significant number of experimental tests to PEM fuel cells were conducted to investigate the effect of gas flow fields on fuel cell performance. Graphite plates with various flow field or flow channel designs, from literature survey and also novel designs by the authors, were used for the PEM fuel cell assembly. The fabricated fuel cells all have an effective membrane area of 23.5 cm2. The results showed that the serpentine flow channel design is still favorable, giving the b...

  8. Effect of gas diffusion layer and membrane properties in an annular proton exchange membrane fuel cell

    Science.gov (United States)

    Khazaee, I.; Ghazikhani, M.; Esfahani, M. Nasr

    2012-01-01

    A complete three-dimensional and single phase computational dynamics model for annular proton exchange membrane (PEM) fuel cell is used to investigate the effect of changing gas diffusion layer and membrane properties on the performances, current density and gas concentration. The proposed model is a full cell model, which includes all the parts of the PEM fuel cell, flow channels, gas diffusion electrodes, catalyst layers and the membrane. Coupled transport and electrochemical kinetics equations are solved in a single domain; therefore no interfacial boundary condition is required at the internal boundaries between cell components. This computational fluid dynamics code is used as the direct problem solver, which is used to simulate the two-dimensional mass, momentum and species transport phenomena as well as the electron- and proton-transfer process taking place in a PEMFC that cannot be investigated experimentally. The results show that by increasing the thickness and decreasing the porosity of GDL the performance of the cell enhances that it is different with planner PEM fuel cell. Also the results show that by decreasing the thickness of the membrane the performance of the cell increases.

  9. Chemically Modified Plastic Tube for High Volume Removal and Collection of Circulating Tumor Cells.

    Directory of Open Access Journals (Sweden)

    Angelo Gaitas

    Full Text Available In this preliminary effort, we use a commercially available and chemically modified tube to selectively capture circulating tumor cells (CTCs from the blood stream by immobilizing human anti-EpCAM antibodies on the tube's interior surface. We describe the requisite and critical steps required to modify a tube into a cancer cell-capturing device. Using these simple modifications, we were able to capture or entrap about 85% of cancer cells from suspension and 44% of cancer cells from spiked whole blood. We also found that the percentage of cells captured was dependent on the tube's length and also the number of cancer cells present. It is our strong belief that with the utilization of appropriate tube lengths and procedures, we can ensure capture and removal of nearly the entire CTC population in whole blood. Importantly after a patient's entire blood volume has circulated through the tube, the tube can then be trypsinized to release the captured live CTCs for further analysis and testing.

  10. Demonstrating the Gas Laws.

    Science.gov (United States)

    Holko, David A.

    1982-01-01

    Presents a complete computer program demonstrating the relationship between volume/pressure for Boyle's Law, volume/temperature for Charles' Law, and volume/moles of gas for Avagadro's Law. The programing reinforces students' application of gas laws and equates a simulated moving piston to theoretical values derived using the ideal gas law.…

  11. Prevention of the water flooding by micronizing the pore structure of gas diffusion layer for polymer electrolyte fuel cell

    Science.gov (United States)

    Hiramitsu, Yusuke; Sato, Hitoshi; Hori, Michio

    In polymer electrolyte fuel cells, high humidity must be established to maintain high proton conductivity in the polymer electrolyte. However, the water that is produced electrochemically at the cathode catalyst layer can condense in the cell and cause an obstruction to the diffusion of reaction gas in the gas diffusion layer and the gas channel. This leads to a sudden decrease of the cell voltage. To combat this, strict water management techniques are required, which usually focus on the gas diffusion layer. In this study, the use of specially treated carbon paper as a flood-proof gas diffusion layer under extremely high humidity conditions was investigated experimentally. The results indicated that flooding originates at the interface between the gas diffusion layer and the catalyst layer, and that such flooding could be eliminated by control of the pore size in the gas diffusion layer at this interface.

  12. Fuel cells: new technology of natural gas for energetical building; Pilas de combustible: nueva tecnologia de gas natural para edificios energeticamente autoabastecidos

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez, A. M.

    2000-07-01

    Fuel Cells have emerged in the last decade as one of the most promising new and sustainable natural gas technologies for meeting the energy needs of all the economy sectors into the 21st century. Fuel Cells are an environmentally clean, quiet, and highly efficient method for generating electricity and heat from natural gas. A fuel cell is an electrochemical device that converts the chemical energy of a fuel directly to usable energy (electricity and heat) without combustion. For this reason, the application and use of the fuel cell technology may be the most important technological advancement of the next century. At the beginning of the 2000 year Sociedad de Gas de Euskadi, s. a. started a demonstration project in favour of the high-temperature planar solid oxide fuel cell (SOFC) for domestic micro-CHP utilization. This type is certainly most exacting from the materials standpoint, and it offers the advantage of uncomplicated fuel pretreatment. (Author)

  13. Compilation and evaluation of gas phase diffusion coefficients of reactive trace gases in the atmosphere: volume 1. Inorganic compounds

    Science.gov (United States)

    Tang, M. J.; Cox, R. A.; Kalberer, M.

    2014-09-01

    Diffusion of gas molecules to the surface is the first step for all gas-surface reactions. Gas phase diffusion can influence and sometimes even limit the overall rates of these reactions; however, there is no database of the gas phase diffusion coefficients of atmospheric reactive trace gases. Here we compile and evaluate, for the first time, the diffusivities (pressure-independent diffusion coefficients) of atmospheric inorganic reactive trace gases reported in the literature. The measured diffusivities are then compared with estimated values using a semi-empirical method developed by Fuller et al. (1966). The diffusivities estimated using Fuller's method are typically found to be in good agreement with the measured values within ±30%, and therefore Fuller's method can be used to estimate the diffusivities of trace gases for which experimental data are not available. The two experimental methods used in the atmospheric chemistry community to measure the gas phase diffusion coefficients are also discussed. A different version of this compilation/evaluation, which will be updated when new data become available, is uploaded online (google.com/site/mingjintang/home/diffusion"target="_blank">https://sites.google.com/site/mingjintang/home/diffusion).

  14. Production of a half cell with a LSM/CGO support for electrochemical flue gas purification

    DEFF Research Database (Denmark)

    Andersen, Kjeld Bøhm; Kammer Hansen, Kent

    2013-01-01

    Described herein is the production of a half cell with a strontium-substituted lanthanum manganite/cerium gadolinium oxide support and dense cerium gadolinium oxide electrolyte for electrochemical flue gas purification. The half cells were constructed through tape casting a strontium......-substituted lanthanum manganite/cerium gadolinium oxide support and cerium gadolinium oxide electrolyte. The half cells were produced by laminating the support and electrolyte layers followed by sintering. Perfectly flat half cells were constructed with a porous strontium-substituted lanthanum manganite....../cerium gadolinium oxide support layer and dense cerium gadolinium oxide electrolyte by adjusting sintering shrinkage at the electrolyte layer and altering the sintering aid....

  15. Microbial electrolysis cells for high yield hydrogen gas production from organic matter.

    Science.gov (United States)

    Logan, Bruce E; Call, Douglas; Cheng, Shaoan; Hamelers, Hubertus V M; Sleutels, Tom H J A; Jeremiasse, Adriaan W; Rozendal, René A

    2008-12-01

    The use of electrochemically active bacteria to break down organic matter, combined with the addition of a small voltage (> 0.2 V in practice) in specially designed microbial electrolysis cells (MECs), can result in a high yield of hydrogen gas. While microbial electrolysis was invented only a few years ago, rapid developments have led to hydrogen yields approaching 100%, energy yields based on electrical energy input many times greater than that possible by water electrolysis, and increased gas production rates. MECs used to make hydrogen gas are similar in design to microbial fuel cells (MFCs) that produce electricity, but there are important differences in architecture and analytical methods used to evaluate performance. We review here the materials, architectures, performance, and energy efficiencies of these MEC systems that show promise as a method for renewable and sustainable energy production, and wastewater treatment.

  16. Microbial Electrolysis Cells for High Yield Hydrogen Gas Production from Organic Matter

    KAUST Repository

    Logan, Bruce E.

    2008-12-01

    The use of electrochemically active bacteria to break down organic matter, combined with the addition of a small voltage (>0.2 V in practice) in specially designed microbial electrolysis cells (MECs), can result in a high yield of hydrogen gas. While microbial electrolysis was invented only a few years ago, rapid developments have led to hydrogen yields approaching 100%, energy yields based on electrical energy input many times greater than that possible by water electrolysis, and increased gas production rates. MECs used to make hydrogen gas are similar in design to microbial fuel cells (MFCs) that produce electricity, but there are important differences in architecture and analytical methods used to evaluate performance. We review here the materials, architectures, performance, and energy efficiencies of these MEC systems that show promise as a method for renewable and sustainable energy production, and wastewater treatment. © 2008 American Chemical Society.

  17. Islands of surviving cells within necrotic volume at liver induced by PDT

    Science.gov (United States)

    Ferreira, J.; Kurachi, C.; Zucoloto, S.; Castro e Silva, O., Jr.; Bagnato, V. S.

    2009-06-01

    Tissue heterogeneities as well as distinct metabolic status and cellular types within a tumor may results in a nonhomogenous necrosis. The possibility of PDT surviving cells within a treated volume has relevant clinical significance. The major aim of this study was to analyze, on normal rat liver, the cell viability and surviving after PDT. The porphyrin was injected through the cava vein at concentration of 1.5 mg/Kg. The induced necrosis was qualitatively investigated varying the used drug light interval (30 min, 1, 3, 6, 24 and 36 h) and total delivered dose (20, 50, 100, 150 and 200 J/cm2). A diode laser at 630 nm and irradiance of 150 mW/cm2 was employed. The exposed livers were removed after the animals were killed by anesthesia overdose, 30 h after illumination. Slides were processed by HE analysis for the determination of the overall aspects of the necrotic and non-treated liver. We observed necrosis of central vein and presence of surviving cell around the portal triad within the necrotic volume, suggesting PDT-resistant regions of the tissue. Possible hypothesis for the observation may be: the absence of photosensitizer; insufficient light dose (below threshold); and distinct metabolic status in the portal triad microregions decreases oxygen availability to photodynamic reaction. The cells surrounding portal triad presented a higher resistance even when 200 J/cm2 was applied. In contrast, the cells closer to the central vein after 20 J/cm2 were already susceptible to the action of PDT. Different aspects of the problem are presented.

  18. Lung function, transfusion, pulmonary capillary blood volume and sickle cell disease.

    Science.gov (United States)

    Lunt, Alan; McGhee, Emily; Robinson, Polly; Rees, David; Height, Susan; Greenough, Anne

    2016-02-01

    Lung function abnormalities occur in children with sickle cell disease (SCD) and may be associated with elevated pulmonary blood volume. To investigate that association, we determined whether blood transfusion in SCD children acutely increased pulmonary capillary blood volume (PCBV) and increased respiratory system resistance (Rrs5). Measurements of Rrs5 and spirometry were made before and after blood transfusion in 18 children, median age 14.2 (6.6-18.5) years. Diffusing capacity for carbon monoxide and nitric oxide were assessed to calculate the PCBV. Post transfusion, the median Rrs5 had increased from 127.4 to 141.3% predicted (pvolume from 39.7 to 64.1 ml/m2 (pvolume in one second (p=0.0056) and vital capacity (p=0.0008) decreased. The increase in Rrs5 correlated with the increase in PCBV (r=0.50, p=0.0493). Increased pulmonary capillary blood volume may at least partially explain the lung function abnormalities in SCD children.

  19. On the relation between free volume and powder pressure with the gas stream in the powder moving-bed; Gasu nagare wo tomonau kotai idoso ni okeru kukanritsu to ryutaiatsu no kankei ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Tomoyasu, Suminao; Yoshino, Akio; Iwata, Hiroshi; Kawazoe, Hiromitsu

    1999-04-05

    On the stand pipe with gas stream equipped the bottom in fluidized bed from powder and equation of continuity of the gas, equation of momentum balance considering frictional force of wall surface and equation of pressure loss of the gas by relative speed and test data on the axial gas pressure distribution besides with stand pipe axial direction powder pressure {sigma}{sub z} relational expression of free volume {epsilon} it asks ask. According to this result, (1) d{sigma}{sub z}/d{epsilon} is increased in free volume or big part in the stand pipe entrance, and it once lowers in the middle, and in addition, it increases in the downward again. That is to say, the inflection point of the powder pressure does the right and presence in the. intermediate. (2) There is mainly the high possibility by the effect of the frictional force of stand pipe wall surface on d{sigma}{sub z}/d{epsilon} increasing in the stand pipe inlet vicinity. (3) The powder pressure is not only free volume but also function of the powder particle diameter too. And, this powder ratio and free volume also showed that the distribution of amount of gas which flow and axial gas pressure, powder pressure, free volume, etc. was obtained the stand pipe from relational expression of particle size and other theoretical formula. (translated by NEDO)

  20. Does the intracellular ionic concentration or the cell water content (cell volume) determine the activity of TonEBP in NIH3T3 cells?

    DEFF Research Database (Denmark)

    Rødgaard, Tina; Schou, Kenneth; Friis, Martin Barfred

    2008-01-01

    of the present investigation was to investigate whether cell shrinkage or high intracellular ionic concentration induced the activation of TonEBP. We designed a model system for isotonically shrinking cells over a prolonged period of time. Cells swelled in hypotonic medium and performed a regulatory volume......Cl(-) co-transporter, and Gadolinium inhibited shrinkage-activated Na(+) channels. Cells remained shrunken for at least 4 hours (isotonically shrunken cells). The activity of TonEBP was investigated with a Luciferase assay after isotonic shrinkage and after shrinkage in a high NaCl hypertonic medium......(+) than isotonically shrunken cells. This strongly suggested that an increase in intracellular ionic concentration and not cell shrinkage is involved in TonEBP activation....

  1. Experimental research on short-term feeding of dust contaminated gas to a molten carbonate fuel cell cathode

    Science.gov (United States)

    Bernat, Rafał; Milewski, Jarosław; Wejrzanowski, Tomasz

    2017-07-01

    The paper presents initial research on processes present on the cathode side of Molten Carbonate Fuel Cells (MCFC), when the supplied gas is an aerosol containing solid particulate matter. The research is based on experiments conducted at the Institute of Heat Engineering of Warsaw University of Technology. The main task is to determine whether and to what extent solid particles disable or hinder the operation of a molten carbonate fuel cell. It is thought that they might change the penetrability of porous layers by clogging their void volumes. Under investigation are the sizes and amount of solid particles required to significantly affect the processes occurring on the triple phase. Experimental investigation was conducted that determined the change in operational parameters due to dust contamination. Surprisingly, there is no sudden drop in the electric parameters of the fuel cell subject to dust poisoning. Supposedly, the dust creates a porous, permeable to gases, structure on the electrode. The only varying parameter was the pressure difference between the inlet and the outlet to the cathode.

  2. Effect of carbon paper substrate of the gas diffusion layer on the performance of proton exchange membrane fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Lin, J.F. [Fuel Cell Research Lab, Engineering Technology Department, Arizona State University, Mesa, AZ 85212 (United States); Wertz, J. [Hollingsworth and Vose Co., A.K. Nicholson Research Lab, 219 Townsend Road, West Groton, MA 01472 (United States); Ahmad, R.; Thommes, M. [Quantachrome Instruments, 1900 Corporate Drive, Boynton Beach, FL 33426 (United States); Kannan, A.M., E-mail: amk@asu.ed [Fuel Cell Research Lab, Engineering Technology Department, Arizona State University, Mesa, AZ 85212 (United States)

    2010-03-01

    Gas diffusion layers (GDLs) were fabricated using non-woven carbon paper substrates with various thicknesses developed by Hollingsworth and Vose Co. Highly consistent carbon slurry containing Pureblack carbon and vapor grown carbon fiber (3:1 ratio) with 25 wt.% Teflon was prepared by using a dispersion agent, Novec-7300 in isopropyl alcohol. Micro-porous layer was coated by using a fully automated Coatema coating tool with a uniform carbon loading of 2.6-3 mg cm{sup -2} using carbon slurry. The surface morphology, contact angle and pore size distribution of the GDLs were examined using SEM, Goniometer and Hg Porosimeter, respectively. Various cathode GDLs assembled into MEAs were evaluated in a single cell PEMFC under various operating relative humidity (RH) conditions using H{sub 2}/O{sub 2} and H{sub 2}/air as reactants. The peak power density of the single cell using the optimum carbon paper substrate thickness was about 1400 and 700 mW cm{sup -2} with H{sub 2}/O{sub 2} and H{sub 2}/air at 60% RH, respectively. It was found that the pore diameter as well as the corresponding pore volumes of the GDLs played a key role in exhibiting the optimum fuel cell performance.

  3. CAPTURING EXHAUST CO2 GAS USING MOLTEN CARBONATE FUEL CELLS

    Directory of Open Access Journals (Sweden)

    Prateek Dhawan

    2016-03-01

    Full Text Available Carbon dioxide is considered as one of the major contenders when the question of greenhouse effect arises. So for any industry or power plant it is of utmost importance to follow certain increasingly stringent environment protection rules and laws. So it is significant to keep eye on any possible methods to reduce carbon dioxide emissions in an efficient way. This paper reviews the available literature so as to try to provide an insight of the possibility of using Molten Carbonate Fuel Cells (MCFCs as the carbon capturing and segregating devices and the various factors that affect the performance of MCFCs during the process of CO2 capture.

  4. Gas Reactor International Cooperative program. Pebble bed reactor plant: screening evaluation. Volume 2. Conceptual balance of plant design

    Energy Technology Data Exchange (ETDEWEB)

    1979-11-01

    This report consists of three volumes which describe the design concepts and screening evaluation for a 3000 MW(t) Pebble Bed Reactor Multiplex Plant (PBR-MX). The Multiplex plant produces both electricity and transportable chemical energy via the thermochemical pipeline (TCP). The evaluation was limited to a direct cycle plant which has the steam generators and steam reformers in the primary circuit. This volume describes the conceptual balance-of-plant (BOP) design and was prepared by United Engineers and Constructors, Inc. of Philadelphia, Pennsylvania. The major emphasis of the BOP study was a preliminary design of an overall plant to provide a basis for future studies.

  5. Factors Determining the Stability of a Gas Cell in an Elastic Medium

    NARCIS (Netherlands)

    Fyrillas, M.M.; Kloek, W.; van Vliet, T.; Mellema, J.

    1999-01-01

    In this paper we consider the stability of a gas cell embedded in an infinite elastic medium. The stability criterion obtained extends the classical result by Gibbs, y < 2E, to include the shear modulus of the elastic material. Interestingly, besides the shear modulus another parameter appears which

  6. Factors Determining the Stability of a Gas Cell in an Elastic Medium

    NARCIS (Netherlands)

    Fyrillas, M.M.; Kloek, W.; Vliet, van T.; Mellema, J.

    1999-01-01

    In this paper we consider the stability of a gas cell embedded in an infinite elastic medium. The stability criterion obtained extends the classical result by Gibbs, y < 2E, to include the shear modulus of the elastic material. Interestingly, besides the shear modulus another parameter appears whic

  7. FUEL CELL OPERATION ON ANAEROBIC DIGESTER GAS: CONCEPTUAL DESIGN AND ASSESSMENT

    Science.gov (United States)

    The conceptual design of a fuel cell (FC) system for operation on anaerobic digester gas (ADG) is described and its economic and environmental feasibility is projected. ADG is produced at water treatment plants during the process of treating sewage anaerobically to reduce solids....

  8. Computational study of liquid-gas cross-flow within structured packing cells

    Science.gov (United States)

    Lavalle, Gianluca; Lucquiaud, Mathieu; Valluri, Prashant

    2016-11-01

    Absorption columns used in the carbon capture processes and filled with structured packings are crucial to foster the exchanges and the transfers between the absorber liquid and the flue gas. However, flow reversal can occur under special flow conditions, resulting in a dramatic drop of the technological performances. We investigate numerically the liquid-gas pattern within a cross-flow packing cell. The cell is a complex geometry with two connected channels, where the two phases flow co- or counter-currently. We show that an increase of both the gas speed and the liquid load leads to an increase of the pressure drop. Particular focus is also given to the analysis of flow repartition and flooding delay. We reveal that tilting the unit cell helps to delay the flooding and extends the operational capability. The pressure drop of the cross-flow unit cell is also compared to the Mellapak packing which is widely used in carbon capture applications. Finally, we support this study by performing numerical simulations on simpler geometries by means of a low-dimensional film-gas model, in order to investigate the two-phase dynamics and predict the flooding onset with a low computational cost. The authors gratefully acknowledge EPSRC Grant No. EP/M001482/1.

  9. Numerical studies on liquid water flooding in gas channels used inpolymer electrolyte fuel cells

    NARCIS (Netherlands)

    Qin, CZ.; Hassanizadeh, S.M.; Rensink, D.

    2012-01-01

    Water management plays an important role in the development of low-temperature polymer electrolyte fuel cells (PEFCs). The lack of a macroscopic gas channel (GC) flooding model constrains the current predictions of PEFC modeling under severe flooding situations. In this work, we have extended our pr

  10. Microbial Electrolysis Cells for High Yield Hydrogen Gas Production from Organic Matter

    NARCIS (Netherlands)

    Logan, B.E.; Call, D.; Cheng, S.; Hamelers, H.V.M.; Sleutels, T.H.J.A.; Jeremiasse, A.W.; Rozendal, R.A.

    2008-01-01

    The use of electrochemically active bacteria to break down organic matter, combined with the addition of a small voltage (>0.2 V in practice) in specially designed microbial electrolysis cells (MECs), can result in a high yield of hydrogen gas. While microbial electrolysis was invented only a few

  11. Direct simulation of liquid water dynamics in the gas channel of a polymer electrolyte fuel cell

    NARCIS (Netherlands)

    Qin, C.; Rensink, D.; Hassanizadeh, S.M.; Fell, S.

    2012-01-01

    For better water management in gas channels (GCs) of polymer electrolyte fuel cells (PEFCs), a profound understanding of the liquid water dynamics is needed. In this study, we propose a novel geometrical setup to conduct a series of direct simulations of the liquid water dynamics in a GC. The conduc

  12. Microbial Electrolysis Cells for High Yield Hydrogen Gas Production from Organic Matter

    NARCIS (Netherlands)

    Logan, B.E.; Call, D.; Cheng, S.; Hamelers, H.V.M.; Sleutels, T.H.J.A.; Jeremiasse, A.W.; Rozendal, R.A.

    2008-01-01

    The use of electrochemically active bacteria to break down organic matter, combined with the addition of a small voltage (>0.2 V in practice) in specially designed microbial electrolysis cells (MECs), can result in a high yield of hydrogen gas. While microbial electrolysis was invented only a few

  13. Comparison of proliferative activity of Wharton jelly mesenchymal stem cells in cultures under various gas conditions

    Directory of Open Access Journals (Sweden)

    Shuvalova N. S.

    2015-06-01

    Full Text Available Aim. To optimize the cultivation of Wharton jelly-derived mesenchyma stem cells (WJ-MSCs using physiological oxygen concentrations, and to compare the effect of “hypoxic” gas mixtures, based on nitrogen and argon, on their proliferative activity. Methods. From the first passage, WJ-MSCs were cultivated during five passages in the nitrogen-based gas mixture (3 % oxygen, 4 % carbon dioxide, 93 % nitrogen and argon-based gas mixture (3 % oxygen, 4 % carbon dioxide, 93 % argon, 7 days before replating. At each passage the final cell number was estimated and the number of population doublings was calculated. Results. The proliferation level of WJ-MSCs, cultured in both gas mixtures with 3 % of O2, was significantly higher compared to that under the regular CO2-incubator conditions. In argon-based mixture, the WJ-MSCs proliferation was higher than in the control but lower than in nitrogen-based mixture. Conclusion. Cultivation of human WJ-MSCs under 3 % O2 had a stimulating effect on the cell proliferation potential. The highest intensity of the cell multiplication was observed in the nitrogen-based mixtures.

  14. Evaluated kinetic and photochemical data for atmospheric chemistry: Volume IV – gas phase reactions of organic halogen species

    Directory of Open Access Journals (Sweden)

    R. Atkinson

    2008-08-01

    Full Text Available This article, the fourth in the series, presents kinetic and photochemical data sheets evaluated by the IUPAC Subcommittee on Gas Kinetic Data Evaluation for Atmospheric Chemistry. It covers the gas phase and photochemical reactions of organic halogen species, which were last published in 1997, and were updated on the IUPAC website in 2006/07. The article consists of a summary sheet, containing the recommended kinetic parameters for the evaluated reactions, and four appendices containing the data sheets, which provide information upon which the recommendations are made.

  15. Evaluated kinetic and photochemical data for atmospheric chemistry: Volume II – gas phase reactions of organic species

    Directory of Open Access Journals (Sweden)

    R. Atkinson

    2006-01-01

    Full Text Available This article, the second in the series, presents kinetic and photochemical data evaluated by the IUPAC Subcommittee on Gas Kinetic Data Evaluation for Atmospheric Chemistry. It covers the gas phase and photochemical reactions of Organic species, which were last published in 1999, and were updated on the IUPAC website in late 2002, and subsequently during the preparation of this article. The article consists of a summary table of the recommended rate coefficients, containing the recommended kinetic parameters for the evaluated reactions, and eight appendices containing the data sheets, which provide information upon which the recommendations are made.

  16. Precision near-infrared radial velocity instrumentation I: Absorption Gas Cells

    CERN Document Server

    Plavchan, Peter P; White, Russel; Gao, Peter; Davison, Cassy; Mills, Sean; Beichman, Chas; Brinkworth, Carolyn; Johnson, John Asher; Bottom, Michael; Ciardi, David; Wallace, J Kent; Mennesson, Bertrand; von Braun, Kaspar; Vasisht, Gautum; Prato, LIsa; Kane, Stephen; Tanner, Angelle; Walp, Bernie; Crawford, Sam; Lin, Sean

    2013-01-01

    We have built and commissioned gas absorption cells for precision spectroscopic radial velocity measurements in the near-infrared in the H and K bands. We describe the construction and installation of three such cells filled with 13CH4, 12CH3D, and 14NH3 for the CSHELL spectrograph at the NASA Infrared Telescope Facility (IRTF). We have obtained their high-resolution laboratory Fourier Transform spectra, which can have other practical uses. We summarize the practical details involved in the construction of the three cells, and the thermal and mechanical control. In all cases, the construction of the cells is very affordable. We are carrying out a pilot survey with the 13CH4 methane gas cell on the CSHELL spectrograph at the IRTF to detect exoplanets around low mass and young stars. We discuss the current status of our survey, with the aim of photon-noise limited radial velocity precision. For adequately bright targets, we are able to probe a noise floor of 7 m/s with the gas cell with CSHELL at cassegrain foc...

  17. Demonstration of neutron detection utilizing open cell foam and noble gas scintillation

    Energy Technology Data Exchange (ETDEWEB)

    Lavelle, C. M., E-mail: christopher.lavelle@jhuapl.edu; Miller, E. C. [The Johns Hopkins University Applied Physics Laboratory, Asymmetric Operations Department, Laurel, Maryland 20723 (United States); Coplan, M. [Institute for Physical Science and Technology, University of Maryland College Park, Maryland 20142 (United States); Thompson, Alan K.; Vest, Robert E.; Yue, A. T. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Kowler, A. L. [Department of Chemical Physics, University of Maryland, College Park, Maryland 20142 (United States); Koeth, T. [Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20142 (United States); Al-Sheikhly, M. [Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742 (United States); Clark, Charles W. [Institute for Physical Science and Technology, University of Maryland College Park, Maryland 20142 (United States); National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Joint Quantum Institute, National Institute of Standards and Technology and University of Maryland, Gaithersburg, Maryland 20899 (United States)

    2015-03-02

    We present results demonstrating neutron detection via a closely spaced converter structure coupled to low pressure noble gas scintillation instrumented by a single photo-multiplier tube (PMT). The converter is dispersed throughout the gas volume using a reticulated vitreous carbon foam coated with boron carbide (B{sub 4}C). A calibrated cold neutron beam is used to measure the neutron detection properties, using a thin film of enriched {sup 10}B as a reference standard. Monte Carlo computations of the ion energy deposition are discussed, including treatment of the foam random network. Results from this study indicate that the foam shadows a significant portion of the scintillation light from the PMT. The high scintillation yield of Xe appears to overcome the light loss, facilitating neutron detection and presenting interesting opportunities for neutron detector design.

  18. Effects of beta interferon on human fibroblasts at different population doubling levels. Proliferation, cell volume, thymidine uptake, and DNA synthesis

    OpenAIRE

    1984-01-01

    Cellular aging had no effect on the ability of beta interferon to increase cell volume and population doubling time in 76-109 cells, a line of human skin fibroblasts. However, DNA synthesis in cells at high population doubling levels (PDL 55-70) was inhibited after 72 h of beta interferon treatment (1,000 U/ml) while no inhibition of DNA synthesis was observed in cells at middle population doubling levels (PDL 30-40).

  19. Dynamic Thermodynamics with Internal Energy, Volume, and Amount of Moles as States : Application to Liquefied Gas Tank

    NARCIS (Netherlands)

    Arendsen, A. R. J.; Versteeg, G. F.

    2009-01-01

    Dynamic models for process design, optimization, and control usually solve a set of heat and/or mass balances as a function of time and/or position in the process. To obtain more robust dynamic models and to minimize the amount of assumptions, internal energy, volume, and amount of moles are chosen

  20. Dynamic Thermodynamics with Internal Energy, Volume, and Amount of Moles as States : Application to Liquefied Gas Tank

    NARCIS (Netherlands)

    Arendsen, A. R. J.; Versteeg, G. F.

    2009-01-01

    Dynamic models for process design, optimization, and control usually solve a set of heat and/or mass balances as a function of time and/or position in the process. To obtain more robust dynamic models and to minimize the amount of assumptions, internal energy, volume, and amount of moles are chosen

  1. Gas composition modeling in a reformed Methanol Fuel Cell system using adaptive Neuro-Fuzzy Inference Systems

    DEFF Research Database (Denmark)

    Justesen, Kristian Kjær; Andreasen, Søren Juhl; Shaker, Hamid Reza

    2013-01-01

    This work presents a method for modeling the gas composition in a Reformed Methanol Fuel Cell system. The method is based on Adaptive Neuro-Fuzzy-Inference-Systems which are trained on experimental data. The developed models are of the H2, CO2, CO and CH3OH mass flows of the reformed gas. The ANFIS......, or fuel cell diagnostics systems....

  2. EGF stimulates IClswell by a redistribution of proteins involved in cell volume regulation.

    Science.gov (United States)

    Tamma, Grazia; Dossena, Silvia; Nofziger, Charity; Valenti, Giovanna; Svelto, Maria; Paulmichl, Markus

    2011-01-01

    ICln is a multifunctional protein involved in the generation of chloride currents activated during regulatory volume decrease (RVD) after cell swelling (ICl(swell)). Growth factor receptors play a key role in different cellular processes and epidermal growth factor (EGF) regulates swelling-activated chloride permeability. We set out to investigate if the EGF-induced upregulation of ICl(swell) could be explained by a rearrangement of ICln subcellular distribution and interaction with its molecular partners. NIH-3T3 fibroblasts were serum-deprived for 24 hours and stimulated with EGF (40 ng/ml) for 30 minutes. ICl(swell) activation, ICln distribution and interaction with its molecular partner HSPC038 were assessed by whole cell patch clamp and fluorescence resonance energy transfer (FRET). EGF treatment significantly enhanced the direct molecular interaction between ICln and HSPC038 and also resulted in an increase of ICln and HSPC038 association with the plasma membrane. Importantly, these events are associated with a significant increase of ICl(swell). The present data indicate that EGF might exert its role in the modulation of volume-sensitive chloride currents in part through activation and translocation of ICln and HSPC038 to the plasma membrane. Copyright © 2011 S. Karger AG, Basel.

  3. Hemorrhagic shock impairs myocardial cell volume regulation and membrane integrity in dogs

    Energy Technology Data Exchange (ETDEWEB)

    Horton, J.W.

    1987-06-01

    An in vitro myocardial slice technique was used to quantitate alterations in cell volume regulation and membrane integrity after 2 h or hemorrhagic shock. After in vitro incubation in Krebs-Ringer-phosphate medium containing trace (/sup 14/C)inulin, values (ml H/sub 2/O/g dry wt) for control nonshocked myocardial slices were 4.03 /plus minus/ 0.11 (SE) for total water, 2.16 /plus minus/ 0.07 for inulin impermeable space, and 1.76 /plus minus/ 0.15 for inulin diffusible space. Shocked myocardial slices showed impaired response to cold incubation. After 2 h of in vivo shock, total tissue water, inulin diffusible space, and inulin impermeable space increased significantly for subendocardium, whereas changes in subepicardium parameters were minimal. Shock-induced cellular swelling was accompanied by an increased total tissue sodium, but no change in tissue potassium. Calcium entry blockade in vivo significantly reduced subendocardial total tissue water as compared with shock-untreated dogs. In addition, calcium entry blockade reduced shock-induced increases in inulin diffusible space. In vitro myocardial slice studies confirm alterations in subendocardial membrane integrity after 2 h of in vivo hemorrhagic shock. Shock-induced abnormalities in myocardial cell volume regulation are reduced by calcium entry blockade in vivo.

  4. Cell and Tissue Organization in the Circulatory and Ventilatory Systems Volume 1 Signaling in Cell Organization, Fate, and Activity, Part A Cell Structure and Environment

    CERN Document Server

    Thiriet, Marc

    2011-01-01

    The volumes in this authoritative series present a multidisciplinary approach to modeling and simulation of flows in the cardiovascular and ventilatory systems, especially multiscale modeling and coupled simulations. The cardiovascular and respiratory systems are tightly coupled, as their primary function is to supply oxygen to and remove carbon dioxide from the body's cells. Because physiological conduits have deformable and reactive walls, macroscopic flow behavior and prediction must be coupled to nano- and microscopic events in a corrector scheme of regulated mechanisms. Therefore, investigation of flows of blood and air in physiological conduits requires an understanding of the biology, chemistry, and physics of these systems together with the mathematical tools to describe their functioning.  The present volume is devoted to cellular events that allow adaptation to environmental conditions, particularly mechanotransduction. It begins with cell organization and a survey of cell types in the vasculatur...

  5. Gas/liquid sensing via chemotaxis of Euglena cells confined in an isolated micro-aquarium.

    Science.gov (United States)

    Ozasa, Kazunari; Lee, Jeesoo; Song, Simon; Hara, Masahiko; Maeda, Mizuo

    2013-10-21

    We demonstrate on-chip gas/liquid sensing by using the chemotaxis of live bacteria (Euglena gracilis) confined in an isolated micro-aquarium, and gas/liquid permeation through porous polydimethylsiloxane (PDMS). The sensing chip consisted of one closed micro-aquarium and two separated bypass microchannels along the perimeter of the micro-aquarium. Test gas/liquid and reference samples were introduced into the two individual microchannels separately, and the gas/liquid permeated through the PDMS walls and dissolved in the micro-aquarium water, resulting in a chemical concentration gradient in the micro-aquarium. By employing the closed micro-aquarium isolated from sample flows, we succeeded in measuring the chemotaxis of Euglena for a gas substance quantitatively, which cannot be achieved with the conventional flow-type or hydro-gel-type microfluidic devices. We found positive (negative) chemotaxis for CO2 concentrations below (above) 15%, with 64 ppm as the minimum concentration affecting the cells. We also observed chemotaxis for ethanol and H2O2. By supplying culture medium via the microchannels, the Euglena culture remained alive for more than 2 months. The sensing chip is thus useful for culturing cells and using them for environmental toxicity/nutrition studies by monitoring their motion.

  6. Gas-filled cell as a narrow bandwidth bandpass filter in the VUV wavelength range

    CERN Document Server

    Geloni, Gianluca; Saldin, Evgeni

    2011-01-01

    We propose a method for spectrally filtering radiation in the VUV wavelength range by means of a monochromator constituted by a cell filled with a resonantly absorbing rare gas. Around particular wavelengths, the gas exhibits narrow-bandwidth absorbing resonances following the Fano profile. In particular, within the photon energy range 60 eV - 65 eV, the correlation index of the Fano profiles for the photo-ionization spectra in Helium is equal to unity, meaning that the minimum of the cross-section is exactly zero. For sufficiently large column density in the gas cell, the spectrum of the incoming radiation will be attenuated by the background cross-section of many orders of magnitude, except for those wavelengths close to the point where the cross-section is zero. Remarkable advantages of a gas monochromator based on this principle are simplicity, efficiency and narrow-bandwidth. A gas monochromator installed in the experimental hall of a VUV SASE FEL facility would enable the delivery of a single-mode VUV l...

  7. Identification and regulation of receptor tyrosine kinases Rse and Mer and their ligand Gas6 in testicular somatic cells.

    Science.gov (United States)

    Chan, M C; Mather, J P; McCray, G; Lee, W M

    2000-01-01

    Receptor tyrosine kinases act to convey extracellular signals to intracellular signaling pathways and ultimately control cell proliferation and differentiation. Rse, Axl, and Mer belong to a newly identified family of cell adhesion molecule-related receptor tyrosine kinase. They bind the vitamin K-dependent protein growth arrest-specific gene 6 (Gas6), which is also structurally related to the anticoagulation factor Protein S. The aim of this study is to investigate the possible role of Rse/Axl/Mer tyrosine kinase receptors and their ligand in regulating testicular functions. Gene expression of Rse, Axl, Mer, and Gas6 in the testis was studied by reverse transcriptase-polymerase chain reaction (RT-PCR) and Northern blot analysis. The results indicated that receptors Rse and Mer and the ligand Gas6 were expressed in the rat endothelial cell line (TR1), mouse Leydig cell line (TM3), rat peritubular myoid cell line (TRM), mouse Sertoli cell line (TM4), and primary rat Sertoli cells. Axl was not expressed in the testicular somatic cells by RT-PCR or Northern blot analysis. The highest level of expression of Gas6 messenger RNA (mRNA) was observed in the Sertoli cells, and its expression was responsive to the addition of forskolin in vitro. The effects of serum, insulin, and transferrin on Gas6 expression by TM4 cells were examined. It was shown that they all exhibited an up-regulating effect on Gas6 expression. The forskolin-stimulated Gas6 expression was accompanied by an increase in tyrosine phosphorylation of the Rse receptor in vitro, suggesting that Gas6 may exhibit an autocrine effect in the Sertoli cells through multiple tyrosine kinase receptors. Our studies so far have demonstrated that tyrosine kinase receptors Rse and Mer and their ligand Gas6 are widely expressed in the testicular somatic cell lines and may play a marked role in promoting testicular cell survival.

  8. U^{28+}-intensity record applying a H_{2}-gas stripper cell

    Directory of Open Access Journals (Sweden)

    Winfried Barth

    2015-04-01

    Full Text Available To meet the Facility for Antiproton and Ion Research science requirements higher beam intensity has to be achieved in the present GSI-accelerator complex. For this an advanced upgrade program for the UNILAC is ongoing. Stripping is a key technology for all heavy ion accelerators. For this an extensive research and development program was carried out to optimize for high brilliance heavy ion operation. After upgrade of the supersonic N_{2}-gas jet (2007, implementation of high current foil stripping (2011 and preliminary investigation of H_{2}-gas jet operation (2012, recently (2014 a new H_{2}-gas cell using a pulsed gas regime synchronized with arrival of the beam pulse has been developed. An obviously enhanced stripper gas density as well as a simultaneously reduced gas load for the pumping system result in an increased stripping efficiency, while the beam emittance remains the same. A new record intensity (7.8 emA for ^{238}U^{28+} beams at 1.4  MeV/u has been achieved applying the pulsed high density H_{2} stripper target to a high intensity ^{238}U^{4+} beam from the VARIS ion source with a newly developed extraction system. The experimental results are presented in detail.

  9. Improvement of performance of gas flow channel in PEM fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Kuo, Jenn-Kun [Graduate Institute of Greenergy Technology, National University of Tainan, 700 Taiwan (China); Yen, Tzu-Shuang; Chen, Cha' o-Kuang [Department of Mechanical Engineering, National Cheng Kung University, Tainan, 70101 Taiwan (China)

    2008-10-15

    This study performs numerical simulations to evaluate the convective heat transfer performance and velocity flow characteristics of the gas flow channel design to enhance the performance of proton exchange membrane fuel cells (PEMFCs). To restrict the current simulations to two-dimensional incompressible flows, the flow regime is assumed to be laminar with a low Reynolds number of approximately 200. In addition, the field synergy principle is applied to demonstrate that an increased interruption within the fluid flow reduces the intersection angle between the velocity vector and the temperature gradient. The interruption within the fluid flow is induced by different type of obstacles: wave like, trapezoid like and ladder like forms and the straight form of the gas flow channel. The numerical results show that, compared to a conventional straight gas flow channel, the wave like, trapezoid like and ladder like geometry of the proposed gas flow channel increases the mean Nusselt number by a factor of approximately two. Furthermore, the periodic three patterns (wave like, trapezoid like and ladder like) structure increases the gas flow velocity in the channel and, hence, improves the catalysis reaction performance in the catalyst layer. Finally, the results show that the three patterns geometry of the gas flow channel reduces the included angle between the velocity vector and the temperature gradient. Hence, the present numerical results are consistent with the field synergy principle, which states that the convective heat transfer is enhanced when the velocity vector and temperature gradient are closely aligned with one another. (author)

  10. U2 8 + -intensity record applying a H2 -gas stripper cell

    Science.gov (United States)

    Barth, Winfried; Adonin, Aleksey; Düllmann, Christoph E.; Heilmann, Manuel; Hollinger, Ralph; Jäger, Egon; Khuyagbaatar, Jadambaa; Krier, Joerg; Scharrer, Paul; Vormann, Hartmut; Yakushev, Alexander

    2015-04-01

    To meet the Facility for Antiproton and Ion Research science requirements higher beam intensity has to be achieved in the present GSI-accelerator complex. For this an advanced upgrade program for the UNILAC is ongoing. Stripping is a key technology for all heavy ion accelerators. For this an extensive research and development program was carried out to optimize for high brilliance heavy ion operation. After upgrade of the supersonic N2 -gas jet (2007), implementation of high current foil stripping (2011) and preliminary investigation of H2 -gas jet operation (2012), recently (2014) a new H2 -gas cell using a pulsed gas regime synchronized with arrival of the beam pulse has been developed. An obviously enhanced stripper gas density as well as a simultaneously reduced gas load for the pumping system result in an increased stripping efficiency, while the beam emittance remains the same. A new record intensity (7.8 emA) for 238U2 8 + beams at 1.4 MeV /u has been achieved applying the pulsed high density H2 stripper target to a high intensity 238U4 + beam from the VARIS ion source with a newly developed extraction system. The experimental results are presented in detail.

  11. USAF Advanced Terrestrial Energy Study. Volume 2. Technology Handbook.

    Science.gov (United States)

    1983-04-01

    volume of Stirling svstems hecause the regenerator determines the dimensions of the system envelone. Table 27. STIRLING SYSTEM VOLUME (CUBIC FEET...Rankine Cycles Batteries Gas Turbines Stirling Engines Thermal Energy Storage 20. ABSTRACT (Confilime 4n roere. olde If neo**WY 41011184100140 & Wee bi A...TECHNOLOGY DESCRIPTIONS 13 Diesels, 13 Gas Turbines. 31 Stirlings , 49 Organic Rankine Cycle; 67 Fuel Cells 83 Photovoltaic Energy Conversion System, 102 Wind

  12. Effects of hydrazine addition on gas evolution and performance of the direct borohydride fuel cell

    Science.gov (United States)

    Qin, H. Y.; Liu, Z. X.; Yin, W. X.; Zhu, J. K.; Li, Z. P.

    A fuel cell configuration using alkaline NaBH 4-N 2H 4 solutions as the fuel is suggested. Gas evolution behaviors and cell performances of alkaline NaBH 4-N 2H 4 solutions on different catalysts have been studied. It is found that gas evolution behaviors are influenced by the applied anodic catalysts and the concentration of NaBH 4 and N 2H 4. NaBH 4 is mainly electro-oxidized on Pd but N 2H 4 is mainly electro-oxidized on Ni and surface-treated Zr-Ni alloy when using NaBH 4-N 2H 4 solutions as the fuel and a composite of Pd, Ni and surface-treated Zr-Ni alloy as the anodic catalyst. The cyclic voltammetry results show that electrochemical oxidation potential of NaBH 4 is higher than that of N 2H 4. Adding hydrazine into alkaline sodium borohydride solutions can suppress gas evolution and improve the cell performance of the DBFC. The performances of fuel cells using NaBH 4-N 2H 4 solutions are comparable to that of fuel cell using N 2H 4 solution.

  13. Gas-liquid interfacial plasmas producing reactive species for cell membrane permeabilization

    Science.gov (United States)

    Kaneko, Toshiro; Sasaki, Shota; Takashima, Keisuke; Kanzaki, Makoto

    2017-01-01

    Gas-liquid interfacial atmospheric-pressure plasma jets (GLI-APPJ) are used medically for plasma-induced cell-membrane permeabilization. In an attempt to identify the dominant factors induced by GLI-APPJ responsible for enhancing cell-membrane permeability, the concentration and distribution of plasma-produced reactive species in the gas and liquid phase regions are measured. These reactive species are classified in terms of their life-span: long-lived (e.g., H2O2), short-lived (e.g., O2•−), and extremely-short-lived (e.g., •OH). The concentration of plasma-produced •OHaq in the liquid phase region decreases with an increase in solution thickness (plasma-induced cell-membrane permeabilization is found to decay markedly as the thickness of the solution increases. Furthermore, the horizontally center-localized distribution of •OHaq, resulting from the center-peaked distribution of •OH in the gas phase region, corresponds with the distribution of the permeabilized cells upon APPJ irradiation, whereas the overall plasma-produced oxidizing species such as H2O2aq in solution exhibit a doughnut-shaped horizontal distribution. These results suggest that •OHaq is likely one of the dominant factors responsible for plasma-induced cell-membrane permeabilization. PMID:28163376

  14. The development and characterization of gas diffusion layers for a PEM fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Jhuly Nascimento dos; Kunst, Sandra Raquel; Malfatti, Celia de Fraga; Amico, Sandro Campos [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil)], Email: Jhuly.nascimento@gmail.com

    2010-07-01

    The need for electrical power generation with minimal environmental impact has driven the development of new systems for energy conversion, such as fuel cells. However, the short life of components and their high cost have limited the production of these devices. The fundamental unit of a PEMFC fuel cell consists of a gas diffusion layer (GDL), a catalyst layer and a polymeric membrane. The GDL drives the flow of gas to the catalytic layer and must possess suitable characteristics with respect to porosity, conductivity, hydrophobicity and chemical stability. In this work, a GDL for low-temperature fuel cells was produced from a suspension containing short carbon fibers in PVA or acrylic water-based resin. The obtained GDL was characterized via wettability and conductivity tests. Besides, the GDL morphology was analyzed by scanning electron microscopy. (author)

  15. Design of the gas cell for the IGISOL facility at ELI-NP

    Science.gov (United States)

    Constantin, P.; Balabanski, D. L.; Anh, L. T.; Cuong, P. V.; Mei, B.

    2017-04-01

    One of the experimental programs that will be carried out at the Extreme Light Infrastructure - Nuclear Physics (ELI-NP) facility is the production of exotic neutron-rich ion beams in an IGISOL facility via photofission in a stack of actinide targets placed at the center of a cell filled with He gas. Simulations with the Geant4 toolkit were done for the optimization of the target configuration that maximizes the rate of released photofission fragments. The cell geometry is established based on the stopping properties of these fragments. Studies, based on simulations with Geant4 and SIMION 8.1, of the space charge effect and its induced electric field in the gas cell are presented. Estimates of the extraction time and efficiency of the photofission fragments are derived.

  16. Design of the gas cell for the IGISOL facility at ELI-NP

    Energy Technology Data Exchange (ETDEWEB)

    Constantin, P., E-mail: paul.constantin@eli-np.ro [Extreme Light Infrastructure – Nuclear Physics, “Horia Hulubei” National Institute for Physics and Nuclear Engineering, Str. Reactorului 30, 077125 Bucharest Magurele (Romania); Balabanski, D.L. [Extreme Light Infrastructure – Nuclear Physics, “Horia Hulubei” National Institute for Physics and Nuclear Engineering, Str. Reactorului 30, 077125 Bucharest Magurele (Romania); Anh, L.T. [Extreme Light Infrastructure – Nuclear Physics, “Horia Hulubei” National Institute for Physics and Nuclear Engineering, Str. Reactorului 30, 077125 Bucharest Magurele (Romania); Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi (Viet Nam); Cuong, P.V. [Extreme Light Infrastructure – Nuclear Physics, “Horia Hulubei” National Institute for Physics and Nuclear Engineering, Str. Reactorului 30, 077125 Bucharest Magurele (Romania); Centre of Nuclear Physics, Institute of Physics, Vietnam Academy of Science and Technology, Hanoi (Viet Nam); Mei, B. [Extreme Light Infrastructure – Nuclear Physics, “Horia Hulubei” National Institute for Physics and Nuclear Engineering, Str. Reactorului 30, 077125 Bucharest Magurele (Romania)

    2017-04-15

    One of the experimental programs that will be carried out at the Extreme Light Infrastructure – Nuclear Physics (ELI-NP) facility is the production of exotic neutron-rich ion beams in an IGISOL facility via photofission in a stack of actinide targets placed at the center of a cell filled with He gas. Simulations with the Geant4 toolkit were done for the optimization of the target configuration that maximizes the rate of released photofission fragments. The cell geometry is established based on the stopping properties of these fragments. Studies, based on simulations with Geant4 and SIMION 8.1, of the space charge effect and its induced electric field in the gas cell are presented. Estimates of the extraction time and efficiency of the photofission fragments are derived.

  17. Thermometry of Guided Molecular Beams from a Cryogenic Buffer-Gas Cell.

    Science.gov (United States)

    Wu, Xing; Gantner, Thomas; Zeppenfeld, Martin; Chervenkov, Sotir; Rempe, Gerhard

    2016-11-18

    A comprehensive characterisation of cold molecular beams from a cryogenic buffer-gas cell, providing insight into the physics of buffer-gas cooling, is presented. Cold molecular beams are extracted from a cryogenic cell by electrostatic guiding, which is also used to measure their velocity distribution. The rotational-state distribution of the molecules is probed by radio-frequency resonant depletion spectroscopy. With the help of complete trajectory simulations, yielding the guiding efficiency for all of the thermally populated states, it is possible to determine both the rotational and the translational temperature of the molecules at the output of the buffer-gas cell. This thermometry method is demonstrated for various regimes of buffer-gas cooling and beam formation as well as for molecular species of different sizes (CH3 F and CF3 CCH). Comparison of the rotational and translational temperatures provides evidence of faster rotational thermalisation for the CH3 F/He system in the limit of low He density. In addition, the relaxation rates for different rotational states appear to be different. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. High-pressure measuring cell for Raman spectroscopic studies of natural gas

    DEFF Research Database (Denmark)

    Hansen, Susanne Brunsgaard; Berg, Rolf W.; Stenby, Erling Halfdan

    2001-01-01

    A system for obtaining Raman spectra of gases at high pressure has been constructed. In order to ensure that a natural gas sample is totally representative, a high-pressure gas-measuring cell has been developed, built up by stainless steel fittings and a sapphire tube. The design and construction...... of this cell are described. A perfect pressure seal has been demonstrated up to 15.0 MPaA (MPa absolute). The cell has been successfully used to obtain Raman spectra of natural gas samples. Some of these spectra are presented and assigned. The most remarkable observation in the spectra is that it is possible...... to detect hydrogen sulfide at concentrations of 1-3 mg H2S/Nm(3). An attempt to make a quantitative analysis of natural gas by the so-called "ratio method" is presented. In addition to this, the relative normalized differential Raman scattering cross sections for ethane and i-butane molecules at 8.0 MPa...

  19. Innovative gas diffusion layers and their water removal characteristics in PEM fuel cell cathode

    Energy Technology Data Exchange (ETDEWEB)

    Jiao, Kui; Zhou, Biao [Department of Mechanical, Automotive and Materials Engineering, University of Windsor, Ont. (Canada)

    2007-06-20

    Liquid water transport is one of the key challenges regarding the water management in a proton exchange membrane (PEM) fuel cell. Conventional gas diffusion layers (GDLs) do not allow a well-organized liquid water flow from catalyst layer to gas flow channels. In this paper, three innovative GDLs with different micro-flow channels were proposed to solve liquid water flooding problems that conventional GDLs have. This paper also presents numerical investigations of air-water flow across the proposed innovative GDLs together with a serpentine gas flow channel on PEM fuel cell cathode by use of a commercial computational fluid dynamics (CFD) software package FLUENT. The results showed that different designs of GDLs will affect the liquid water flow patterns significantly, thus influencing the performance of PEM fuel cells. The detailed flow patterns of liquid water were shown. Several gas flow problems for the proposed different kinds of innovative GDLs were observed, and some useful suggestions were given through investigating the flow patterns inside the proposed GDLs. (author)

  20. Thermometry of Guided Molecular Beams from a Cryogenic Buffer-Gas Cell

    CERN Document Server

    Wu, X; Zeppenfeld, M; Chervenkov, S; Rempe, G

    2016-01-01

    We present a comprehensive characterization of cold molecular beams from a cryogenic buffer-gas cell, providing an insight into the physics of buffer-gas cooling. Cold molecular beams are extracted from a cryogenic cell by electrostatic guiding, which is also used to measure their velocity distribution. Molecules' rotational-state distribution is probed via radio-frequency resonant depletion spectroscopy. With the help of complete trajectory simulations, yielding the guiding efficiency for all of the thermally populated states, we are able to determine both the rotational and the translational temperature of the molecules at the output of the buffer-gas cell. This thermometry method is demonstrated for various regimes of buffer-gas cooling and beam formation as well as for molecular species of different sizes, $\\rm{CH_3F}$ and $\\rm{CF_3CCH}$. Comparison between the rotational and translational temperatures provides evidence of faster rotational thermalization for the $\\rm{CH_3F-He}$ system in the limit of low...

  1. In-gas-cell laser ionization studies of plutonium isotopes at IGISOL

    Science.gov (United States)

    Pohjalainen, I.; Moore, I. D.; Kron, T.; Raeder, S.; Sonnenschein, V.; Tomita, H.; Trautmann, N.; Voss, A.; Wendt, K.

    2016-06-01

    In-gas-cell resonance laser ionization has been performed on long-lived isotopes of Pu at the IGISOL facility, Jyväskylä. This initiates a new programme of research towards high-resolution optical spectroscopy of heavy actinide elements which can be produced in sufficient quantities at research reactors and transported to facilities elsewhere. In this work a new gas cell has been constructed for fast extraction of laser-ionized elements. Samples of 238-240,242Pu and 244Pu have been evaporated from Ta filaments, laser ionized, mass separated and delivered to the collinear laser spectroscopy station. Here we report on the performance of the gas cell through studies of the mass spectra obtained in helium and argon, before and after the radiofrequency quadrupole cooler-buncher. This provides valuable insight into the gas phase chemistry exhibited by Pu, which has been additionally supported by measurements of ion time profiles. The resulting monoatomic yields are sufficient for collinear laser spectroscopy. A gamma-ray spectroscopic analysis of the Pu samples shows a good agreement with the assay provided by the Mainz Nuclear Chemistry department.

  2. Reproducibility of the Helium-3 Constant-Volume Gas Thermometry and New Data Down to 1.9 K at NMIJ/AIST

    Science.gov (United States)

    Nakano, Tohru; Shimazaki, Takeshi; Tamura, Osamu

    2017-07-01

    This study confirms reproducibility of the International Temperature Scale of 1990 (ITS-90) realized by interpolation using the constant-volume gas thermometer (CVGT) of National Metrology Institute of Japan (NMIJ)/AIST with 3He as the working gas from 3 K to 24.5561 K by comparing the newly obtained results and those of earlier reports, indicating that the CVGT has retained its capability after renovation undertaken since strong earthquakes struck Japan. The thermodynamic temperature T is also obtained using the single-isotherm fit to four working gas densities (127 mol\\cdot m^{-3}, 145 mol\\cdot m^{-3}, 171 mol\\cdot m^{-3} and 278 mol\\cdot m^{-3}) down to 1.9 K, using the triple point temperature of Ne as a reference temperature. In this study, only the second virial coefficient is taken into account for the single-isotherm fit. Differences between T and the ITS-90 temperature, T-T_{90}, reported in earlier works down to 3 K were confirmed in this study. At the temperatures below 3 K down to 2.5 K, T-T_{90} is much smaller than the standard combined uncertainty of thermodynamic temperature measurement. However, T- T_{90} seems to increase with decreasing temperature below 2.5 K down to 1.9 K, although still within the standard combined uncertainty of thermodynamic temperature measurement. In this study, T is obtained also from the CVGT with a single gas density of 278 mol\\cdot m^{-3} using the triple-point temperature of Ne as a reference temperature by making correction for the deviation from the ideal gas using theoretical values of the second and third virial coefficients down to 2.6 K, which is the lowest temperature of the theoretical values of the third virial coefficient. T values obtained using this method agree well with those obtained from the single-isotherm fit. We also found that the second virial coefficient obtained by the single-isotherm fit to experimental results agrees well with that obtained by the single-isotherm fit to the theoretically

  3. Particle-in-cell modeling of gas-confined barrier discharge

    Science.gov (United States)

    Levko, Dmitry; Raja, Laxminarayan L.

    2016-04-01

    Gas-confined barrier discharge is studied using the one-dimensional Particle-in-Cell Monte Carlo Collisions model for the conditions reported by Guerra-Garcia and Martinez-Sanchez [Appl. Phys. Lett. 106, 041601 (2015)]. Depending on the applied voltage, two modes of discharge are observed. In the first mode, the discharge develops in the entire interelectrode gap. In the second mode, the discharge is ignited and develops only in the gas layer having smaller breakdown voltage. The one-dimensional model shows that for the conditions considered, there is no streamer stage of breakdown as is typical for a traditional dielectric barrier discharge.

  4. Particle-in-cell modeling of gas-confined barrier discharge

    Energy Technology Data Exchange (ETDEWEB)

    Levko, Dmitry; Raja, Laxminarayan L. [Department of Aerospace Engineering and Engineering Mechanics, The University of Texas at Austin, Austin, Texas 78712 (United States)

    2016-04-15

    Gas-confined barrier discharge is studied using the one-dimensional Particle-in-Cell Monte Carlo Collisions model for the conditions reported by Guerra-Garcia and Martinez-Sanchez [Appl. Phys. Lett. 106, 041601 (2015)]. Depending on the applied voltage, two modes of discharge are observed. In the first mode, the discharge develops in the entire interelectrode gap. In the second mode, the discharge is ignited and develops only in the gas layer having smaller breakdown voltage. The one-dimensional model shows that for the conditions considered, there is no streamer stage of breakdown as is typical for a traditional dielectric barrier discharge.

  5. Stem cell harvesting protocol research in autologous transplantation setting: Large volume vs. conventional cytapheresis

    Directory of Open Access Journals (Sweden)

    Balint Bela

    2008-01-01

    Full Text Available Background/Aim. The use of peripheral blood as a source of hematopoietic stem cells (SCs is progressively increasing and has nearly supplanted bone marrow transplantation. Interpatient variability in the degree and kinetics of SC mobilization into peripheral blood is an expected event after conventional chemotherapy-based treatment, followed by sequential administration of recombinant granulocyte-colony- stimulating factor (rHu-CSF. In this study, specific factors associated with the application of two different SC-harvesting approaches, including the use of large volume leukapheresis (LVL vs. repetitive conventional apheresis (RCA, were analyzed. The basic goal of the study was to evaluate the influence of apheresis protocol (collection timing, processed blood volume and cell yield upon the clinical outcome of transplantation. Methods. Results obtained by LVL (76 pts and RCA (20 pts - control group were compared. The SC mobilizing regimen used was cyclophosphamide (4-7 g/m2 or polychemotherapy and rHuG-CSF 10-16 μg/kg of body mess (bm per day. Cell harvesting was performed using COBE-Spectra (Caridian-BCT, USA. The volume of processed blood in LVL setting was ≥ 3.5 - fold of the patient's circulating blood quantity (ranged from 12.7 to 37.8 l. All patients tolerated well the use of intensive treatment, without any side or adverse effects. Our original controlled-rate cryopreservation was carried out with 10% dimethyl sulfoxide (DMSO using Planer R203/200R or Planer 560-16 equipments (Planer Products Ltd, UK. Total nucleated cell (NC and mononuclear cell (MNC counts were examined by flow cytometry (Advia-2120 Bayer, Germany; Technicon H-3 System, USA. The CD34+ cell surface antigen was investigated by the EPICS XL-MCL device (Coulter, Germany. Results. Performing LVL-apheresis, high-level MNC and CD34+ cell yields (7.6±4.6 × 108/kg bm and 11.8±6.5 × 106/kg bm, respectively were obtained. As a result, rapid hematopoietic reconstitution

  6. Ionized gas (plasma) delivery of reactive oxygen species (ROS) into artificial cells

    Science.gov (United States)

    Hong, Sung-Ha; Szili, Endre J.; Jenkins, A. Toby A.; Short, Robert D.

    2014-09-01

    This study was designed to enhance our understanding of how reactive oxygen species (ROS), generated ex situ by ionized gas (plasma), can affect the regulation of signalling processes within cells. A model system, comprising of a suspension of phospholipid vesicles (cell mimics) encapsulating a ROS reporter, was developed to study the plasma delivery of ROS into cells. For the first time it was shown that plasma unequivocally delivers ROS into cells over a sustained period and without compromising cell membrane integrity. An important consideration in cell and biological assays is the presence of serum, which significantly reduced the transfer efficiency of ROS into the vesicles. These results are key to understanding how plasma treatments can be tailored for specific medical or biotechnology applications. Further, the phospholipid vesicle ROS reporter system may find use in other studies involving the application of free radicals in biology and medicine.

  7. Gas Reactor International Cooperative program. Pebble bed reactor plant: screening evaluation. Volume 3. Appendix A. Equipment list

    Energy Technology Data Exchange (ETDEWEB)

    1979-11-01

    This report consists of three volumes which describe the design concepts and screening evaluation for a 3000 MW(t) Pebble Bed Reactor Multiplex Plant (PBR-MX). The Multiplex plant produces both electricity and transportable chemical energy via the thermochemical pipeline (TCP). The evaluation was limited to a direct cycle plant which has the steam generators and steam reformers in the primary circuit. Volume 1 reports the overall plant and reactor system and was prepared by the General Electric Company. Core scoping studies were performed which evaluated the effects of annular and cylindrical core configurations, radial blanket zones, burnup, and ball heavy metal loadings. The reactor system, including the PCRV, was investigated for both the annular and cylindrical core configurations. Volume 3 is an Appendix containing the equipment list for the plant and was also prepared by United Engineers and Constructors, Inc. It tabulates the major components of the plant and describes each in terms of quantity, type, orientation, etc., to provide a basis for cost estimation.

  8. Diffusion and Gas Conversion Analysis of Solid Oxide Fuel Cells at Loads via AC Impedance

    Directory of Open Access Journals (Sweden)

    Robert U. Payne

    2011-01-01

    Full Text Available Impedance measurements were conducted under practical load conditions in solid oxide fuel cells of differing sizes. For a 2 cm2 button cell, impedance spectra data were separately measured for the anode, cathode, and total cell. Improved equivalent circuit models are proposed and applied to simulate each of measured impedance data. Circuit elements related to the chemical and physical processes have been added to the total-cell model to account for an extra relaxation process in the spectra not measured at either electrode. The processes to which elements are attributed have been deduced by varying cell temperature, load current, and hydrogen concentration. Spectra data were also obtained for a planar stack of five 61 cm2 cells and the individual cells therein, which were fitted to a simplified equivalent circuit model of the total button cell. Similar to the button cell, the planar cells and stack exhibit a pronounced low-frequency relaxation process, which has been attributed to concentration losses, that is, the combined effects of diffusion and gas conversion. The simplified total-cell model approximates well the dynamic behavior of the SOFC cells and the whole stack.

  9. Wheat dextrin, psyllium, and inulin produce distinct fermentation patterns, gas volumes, and short-chain fatty acid profiles in vitro.

    Science.gov (United States)

    Timm, Derek A; Stewart, Maria L; Hospattankar, Ashok; Slavin, Joanne L

    2010-08-01

    Dietary fiber fermentation decreases luminal pH by the production of short-chain fatty acids (SCFAs). Additional proposed physiological benefits of fiber fermentation include decreased growth of pathogenic bacteria, increased mineral absorption, and serving as an energy source for the colon epithelium. This study examined three common fiber supplements--wheat dextrin (WD) (Benefiber, Novartis Consumer Health Inc., Parsippany, NJ, USA), psyllium (PS) (Metamucil, Procter & Gamble, Cincinnati, OH, USA), and inulin (Fiber Sure, Procter & Gamble)--for pH, SCFAs, and gas production. An established in vitro fermentation model was used to simulate colonic fermentation at 0, 4, 8, 12, and 24 hours. At 24 hours, WD and inulin significantly decreased pH compared to PS. Inulin produced significantly more hydrogen and total gas. All treatments produced similar total SCFA concentrations at 24 hours; however, the rate of production was different. PS had a declining rate of SCFA production from 12 to 24 hours, whereas WD and inulin had a higher rate during that period. Fast-fermenting substrates may not provide as much SCFAs to the distal colon as slow-fermenting substrates. Differences in fermentation rate, gas production, and SCFA production observed for WD, PS, and inulin may affect their gastrointestinal tolerance and require further study.

  10. Estimating Fatty Acid Composition of Infant Buccal Mucosal Cells by Capillary Gas Chromatography

    Institute of Scientific and Technical Information of China (English)

    CHEN Fei; ZHANG Wei-li; LI Fang; ZHU Xiao-dong; ZHU Jian-xing

    2008-01-01

    Long chain polyunsaturated fatty adds, i. e., docosahexaenoic acid (DHA or C22 : 6n -3), arachidonic acid (AA or C20 : 4n - 6) have been identified as essential fatty acids and play an important role in growth and development of infants. Mensurement of fatty acid composition is usually by collection of blood, but to obtain blood in infants is difficult. Nowadays, the fatty acid composition can be estimated by collecting buccal mucosal cells, which can avoid repeated blood sampling. The purpose of this paper is to compare the fatty acid composition of cheek calls with that of plasma and red blood cells (RBCs). In this study, twenty-seven infants were enrolled, and buccal mucosal cells and blood samples were obtained from these infants of the same time. Fatty acid composition of buccal mucesal cells, plasma and RBCs were measured by capillary gas chromatography. The results show that the contents of AA and DHA in the buccal mucosal cells are correlated well with that in the plasma [r=0.36 (P=0.042) and r=0.38 (P=0.033), respectively]. The ratio of AA to DHA is 1.32% in buccal mucosal cells, 1.60% in plasma and 1.55% in RBCs and there are no significant differences among groups (P = 0.134). It shows that the fatty acid composition in buccal mucosal cells can reflect the fat nutrition status in infants and can be detected by capillary gas chromatography. Estimating fatty acid composition of buccal mucosal cells in infants by capillary gas chromatography is feasible, and because of its noninvasiveness, it can be suitable for nutrition research in infants.

  11. Local area water removal analysis of a proton exchange membrane fuel cell under gas purge conditions.

    Science.gov (United States)

    Lee, Chi-Yuan; Lee, Yu-Ming; Lee, Shuo-Jen

    2012-01-01

    In this study, local area water content distribution under various gas purging conditions are experimentally analyzed for the first time. The local high frequency resistance (HFR) is measured using novel micro sensors. The results reveal that the liquid water removal rate in a membrane electrode assembly (MEA) is non-uniform. In the under-the-channel area, the removal of liquid water is governed by both convective and diffusive flux of the through-plane drying. Thus, almost all of the liquid water is removed within 30 s of purging with gas. However, liquid water that is stored in the under-the-rib area is not easy to remove during 1 min of gas purging. Therefore, the re-hydration of the membrane by internal diffusive flux is faster than that in the under-the-channel area. Consequently, local fuel starvation and membrane degradation can degrade the performance of a fuel cell that is started from cold.

  12. Control oriented modeling of ejector in anode gas recirculation solid oxygen fuel cell systems

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Yinhai, E-mail: yinhai.zhu@gmail.co [School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); Li Yanzhong, E-mail: yzli-epe@mail.xjtu.edu.c [School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); Cai Wenjian [School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore)

    2011-04-15

    A one-equation model is proposed for fuel ejector in anode gas recirculation solid oxide fuel cell (SOFC) system. Firstly, the fundamental governing equations are established by employing the thermodynamic, fluid dynamic principles and chemical constraints inside the ejector; secondly, the one-equation model is derived by using the parameter analysis and lumped-parameter method. Finally, the computational fluid dynamics (CFD) technique is employed to obtain the source data for determining the model parameters. The effectiveness of the model is studied under a wide range of operation conditions. The effect of ejector performance on the anode gas recirculation SOFC system is also discussed. The presented model, which only contains four constant parameters, is useful in real-time control and optimization of fuel ejector in the anode gas recirculation SOFC system.

  13. Study of a distributed feedback diode laser based hygrometer combined Herriot-gas cell and waterless optical components

    Science.gov (United States)

    Wei, Yubin; Chang, Jun; Lian, Jie; Wang, Qiang; Wei, Wei

    2016-09-01

    A distributed feedback diode laser (DFB-DL) based hygrometer combined with a long-path-length Herriot gas cell and waterless optical components was proposed and investigated. The main function of this sensor was to simultaneously improve the measurement reliability and resolution. A comparison test between a 10-cm normal transmission-type gas cell and a 3-m Herriot gas cell was carried out to demonstrate the improvement. Reliability improvement was achieved by influence suppression of water vapor inside optical components (WVOC) through combined action of the Herriot gas cell and waterless optical components. The influence of WVOC was suppressed from 726 ppmv to 25 ppmv using the Herriot gas cell. Moreover, combined with waterless optical components, the influence of WVOC was further suppressed to no more than 4 ppmv. Resolution improvement from 11.7 ppmv to 0.32 ppmv was achieved mainly due to the application of the long-path-length Herriot gas cell. The results show that the proposed sensor has a good performance and considerable potential application in gas sensing, especially when probed gas possibly permeates into optical components.

  14. Potassium-chloride cotransporter 3 interacts with Vav2 to synchronize the cell volume decrease response with cell protrusion dynamics.

    Directory of Open Access Journals (Sweden)

    Adèle Salin-Cantegrel

    Full Text Available Loss-of-function of the potassium-chloride cotransporter 3 (KCC3 causes hereditary motor and sensory neuropathy with agenesis of the corpus callosum (HMSN/ACC, a severe neurodegenerative disease associated with defective midline crossing of commissural axons in the brain. Conversely, KCC3 over-expression in breast, ovarian and cervical cancer is associated with enhanced tumor cell malignancy and invasiveness. We identified a highly conserved proline-rich sequence within the C-terminus of the cotransporter which when mutated leads to loss of the KCC3-dependent regulatory volume decrease (RVD response in Xenopus Laevis oocytes. Using SH3 domain arrays, we found that this poly-proline motif is a binding site for SH3-domain containing proteins in vitro. This approach identified the guanine nucleotide exchange factor (GEF Vav2 as a candidate partner for KCC3. KCC3/Vav2 physical interaction was confirmed using GST-pull down assays and immuno-based experiments. In cultured cervical cancer cells, KCC3 co-localized with the active form of Vav2 in swelling-induced actin-rich protruding sites and within lamellipodia of spreading and migrating cells. These data provide evidence of a molecular and functional link between the potassium-chloride co-transporters and the Rho GTPase-dependent actin remodeling machinery in RVD, cell spreading and cell protrusion dynamics, thus providing new insights into KCC3's involvement in cancer cell malignancy and in corpus callosum agenesis in HMSN/ACC.

  15. Cell volume and geometric parameters determination in living cells using confocal microscopy and 3D reconstruction

    OpenAIRE

    sprotocols

    2015-01-01

    Authors: David Hevia, Aida Rodriguez-Garcia, Marta Alonso-Gervós, Isabel Quirós-González, Henar M Cimadevilla, Carmen Gómez-Cordovés, Rosa M Sainz & Juan C Mayo ### Abstract The protocol reported here describes a simple, easy, fast and reproducible method aimed to know the geometric parameters of living cells based on confocal laser scanning microscopy combined with 3D reconstruction software. Briefly, the method is based on intrinsic fluorescence properties of acridine orange (AO...

  16. Variation of Red Blood Cell Distribution Width and Mean Platelet Volume after Moderate Endurance Exercise

    Directory of Open Access Journals (Sweden)

    Giuseppe Lippi

    2014-01-01

    Full Text Available Although physical exercise strongly influences several laboratory parameters, data about the hematological changes after medium distance running are scarce. We studied 31 middle-trained athletes (mean training regimen 217±32 min/week who performed a 21.1 km, half-marathon run. Blood samples were collected before the run, at the end, and 3 and 20 hours thereafter. The complete blood count was performed on Advia 2120 and included red blood cell (RBC, reticulocyte, and platelet counts; hemoglobin; mean corpuscular volume (MCV; mean corpuscular hemoglobin (MCH; reticulocyte haemoglobin content (Ret CHR; RBC distribution width (RDW, mean platelet volume (MPV. No significant variations were observed for MCH and Ret CHR. The RBC, reticulocyte, and hemoglobin values modestly decreased after the run. The MCV significantly increased at the end of running but returned to baseline 3 hours thereafter. The RDW constantly increased, reaching a peak 20 hours after the run. The platelet count and MPV both increased after the run and returned to baseline 3 hours thereafter. These results may have implications for definition of reference ranges and antidoping testing, and may also contribute to explaining the relationship between endurance exercise and mortality, since previous studies reported that RDW and MPV may be significantly associated with cardiovascular disease.

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

    Energy Technology Data Exchange (ETDEWEB)

    Mehraeen, Shareghe [Univ. of California, Davis, CA (United States). Dept. of Molecular and Cellular Biology; McKeown, Joseph T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Condensed Matter and Materials Division; Deshmukh, Pushkarraj V. [E.A. Fischione Instruments, Inc., Export, PA (United States); Evans, James E. [Univ. of California, Davis, CA (United States). Dept. of Molecular and Cellular Biology; Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Chemical and Materials Science Division; Abellan, Patricia [Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Chemical and Materials Science Division; Xu, Pinghong [Univ. of California, Davis, CA (United States). Dept. of Chemical Engineering and Materials Science; Reed, Bryan W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Condensed Matter and Materials Division; Taheri, Mitra L. [Drexel Univ., Philadelphia, PA (United States). Dept. of Materials Science & Engineering; Fischione, Paul E. [E.A. Fischione Instruments, Inc., Export, PA (United States); Browning, Nigel D. [Univ. of California, Davis, CA (United States). Dept. of Molecular and Cellular Biology; Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Chemical and Materials Science Division; Univ. of California, Davis, CA (United States). Dept. of Chemical Engineering and Materials Science

    2013-03-04

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

  18. Dynamic Thermodynamics with Internal Energy, Volume, and Amount of Moles as States: Application to Liquefied Gas Tank

    OpenAIRE

    Arendsen, A. R. J.; Versteeg, G. F.

    2009-01-01

    Dynamic models for process design, optimization, and control usually solve a set of heat and/or mass balances as a function of time and/or position in the process. To obtain more robust dynamic models and to minimize the amount of assumptions, internal energy, volume, and amount of moles are chosen as states for the conservation laws of the dynamic model. Temperature, pressure, and the amount and composition of the phases are calculated on the basis of these states at every time step. The Red...

  19. [Research on fiber methane sensing system based on prism gas cell].

    Science.gov (United States)

    Wu, Xi-Jun; Wang, Yu-Tian; Liu, Xue-Cai; Li, Shu-Jun

    2010-05-01

    A novel fiber methane detection system was constructed based on integration of prism gas cell and harmonic detection technique. The system can be applied to broad-range concentration detection. Grounded on the Beer-Lambert approximation, the detection of various concentration (0-20%) of methane was completed using subtraction of background and ratio processing method, as the atmosphere surroundings was treated as background. The direct absorption spectra for various concentration were measured using GRIN gas cell, combined with available DFB-LD, and the R5 line of the 2v3 band of methane was selected as absorption peak. The system was tested online during gas mixing process and the linear relation between system indication and concentration variation was validated, while the stability and dynamic response characteristics was confirmed by experiments. The system sensitivity can be adjusted according to the concentration level of various field environments by changing the prism distance using step motor. So that, the system can be applied to various application fields and can be adopted as a monitoring instrument for coalmine tunnel and natural gas pipeline.

  20. Novel Application of Carbonate Fuel Cell for Capturing Carbon Dioxide from Flue Gas Streams

    Energy Technology Data Exchange (ETDEWEB)

    Jolly, Stephen; Ghezel-Ayagh, Hossein; Willman, Carl; Patel, Dilip; DiNitto, M.; Marina, Olga A.; Pederson, Larry R.; Steen, William A.

    2015-09-30

    To address concerns about climate change resulting from emission of CO2 by coal-fueled power plants, FuelCell Energy, Inc. has developed the Combined Electric Power and Carbon-dioxide Separation (CEPACS) system concept. The CEPACS system utilizes Electrochemical Membrane (ECM) technology derived from the Company’s Direct FuelCell® products. The system separates the CO2 from the flue gas of other plants and produces electric power using a supplementary fuel. FCE is currently evaluating the use of ECM to cost effectively separate CO2 from the flue gas of Pulverized Coal (PC) power plants under a U.S. Department of Energy contract. The overarching objective of the project is to verify that the ECM can achieve at least 90% CO2 capture from the flue gas with no more than 35% increase in the cost of electricity. The project activities include: 1) laboratory scale operational and performance tests of a membrane assembly, 2) performance tests of the membrane to evaluate the effects of impurities present in the coal plant flue gas, in collaboration with Pacific Northwest National Laboratory, 3) techno-economic analysis for an ECM-based CO2 capture system applied to a 550 MW existing PC plant, in partnership with URS Corporation, and 4) bench scale (11.7 m2 area) testing of an ECM-based CO2 separation and purification system.

  1. Genealogy of gas cells for low-energy RI-beam production

    Energy Technology Data Exchange (ETDEWEB)

    Wada, Michiharu, E-mail: mw@riken.jp

    2013-12-15

    Highlights: • In order to overcome serious limitations in the universality of the traditional isotope separator on-line technique, various endeavors have been made on gas catcher cells for converting relativistic RI-beams from in-flight separators to low-energy RI-beams. • The origin of the gas catcher is found in the IGISOL (Ion guide isotope separator on-line) technique. • Many developments have been made over the years to overcome the various difficulties and drawbacks found in the IGISOL technique. -- Abstract: In order to overcome serious limitations in the universality of the traditional isotope separator on-line technique, various endeavors have been made on gas catcher cells for converting relativistic RI-beams from in-flight separators to low-energy RI-beams. The origin of the gas catcher is found in the IGISOL (Ion guide isotope separator on-line) technique. Many developments have been made over the years to overcome the various difficulties and drawbacks found in the IGISOL technique.

  2. Gas6 Delays Senescence in Vascular Smooth Muscle Cells through the PI3K/ Akt/FoxO Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Cheng-wei Jin

    2015-02-01

    Full Text Available Background/Aims: Growth arrest-specific protein 6 (Gas6 is a cytokine that can be synthesized by a variety of cell types and secreted into the extracellular matrix. Previous studies have confirmed that Gas6 is involved in certain pathophysiological processes of the cardiovascular system through binding to its receptor, Axl. In the present study, we investigated the role of Gas6 in cellular senescence and explored the mechanisms underlying its activity. Methods: We used vascular smooth muscle cells (VSMCs to create two cellular senescence models, one for replicative senescence (RS and one for induced senescence (IS, to test the hypothesis that Gas6 delays senescence. Results: Gas6-treated cells appear relatively younger compared with non-Gas6-treated cells. In particular, Gas6-treated cells displayed decreased staining for SA-β-Gal, fewer G1 phase cells, and decreased levels of p16INK4a and p21Cip1 expression; conversely, Gas6-treated cells displayed more S phase cells and significantly increased proliferation indexes. Furthermore, in both the IS and RS models with Gas6 treatment, the levels of PI3K, p-Akt, and p-FoxO3a decreased following Axl inhibition by R428; similarly, the levels of p-Akt and p-FoxO3a also decreased following PI3K inhibition by LY294002. Conclusion: Gas6/Axl signaling is essential for delaying the cellular senescence process regulated by the PI3K/Akt/FoxO signaling pathway.

  3. A method to estimate weight and dimensions of aircraft gas turbine engines. Volume 1: Method of analysis

    Science.gov (United States)

    Pera, R. J.; Onat, E.; Klees, G. W.; Tjonneland, E.

    1977-01-01

    Weight and envelope dimensions of aircraft gas turbine engines are estimated within plus or minus 5% to 10% using a computer method based on correlations of component weight and design features of 29 data base engines. Rotating components are estimated by a preliminary design procedure where blade geometry, operating conditions, material properties, shaft speed, hub-tip ratio, etc., are the primary independent variables used. The development and justification of the method selected, the various methods of analysis, the use of the program, and a description of the input/output data are discussed.

  4. Cell volume changes affect gluconeogenesis in the perfused liver of the catfish Clarias batrachus

    Indian Academy of Sciences (India)

    Carina Goswami; Shritapa Datta; Kuheli Biswas; Nirmalendu Saha

    2004-09-01

    In addition to lactate and pyruvate, some amino acids were found to serve as potential gluconeogenic substrates in the perfused liver of Clarias batrachus. Glutamate was found to be the most effective substrate, followed by lactate, pyruvate, serine, ornithine, proline, glutamine, glycine, and aspartate. Four gluconeogenic enzymes, namely phosphoenolpyruvate carboxykinase (PEPCK), pyruvate carboxylase (PC), fructose 1,6-bisphosphatase (FBPase) and glucose 6-phosphatase (G6Pase) could be detected mainly in liver and kidney, suggesting that the latter are the two major organs responsible for gluconeogenic activity in this fish. Hypo-osmotically induced cell swelling caused a significant decrease of gluconeogenic efflux accompanied with significant decrease of activities of PEPCK, FBPase and G6Pase enzymes in the perfused liver. Opposing effects were seen in response to hyper-osmotically induced cell shrinkage. These changes were partly blocked in the presence of cycloheximide, suggesting that the aniso-osmotic regulations of gluconeogenesis possibly occurs through an inverse regulation of enzyme proteins and/or a regulatory protein synthesis in this catfish. In conclusion, gluconeogenesis appears to play a vital role in C. batrachus in maintaining glucose homeostasis, which is influenced by cell volume changes possibly for proper energy supply under osmotic stress.

  5. Measurement of Single Cell Refractive Index, Dry Mass, Volume, and Density Using a Transillumination Microscope

    Science.gov (United States)

    Phillips, Kevin G.; Jacques, Steven L.; McCarty, Owen J. T.

    2012-09-01

    Phase contrast microscopy has become ubiquitous in the field of biology, particularly in qualitative investigations of cellular morphology. However, the use of quantitative phase retrieval methods and their connection to cellular refractive index and dry mass density remain under utilized. This is due in part to the restriction of phase and cellular mass determination to custom built instruments, involved mathematical analysis, and prohibitive sample perturbations. We introduce tomographic bright field imaging, an accessible optical imaging technique enabling the three dimensional measurement of cellular refractive index and dry mass density using a standard transillumination optical microscope. The validity of the technique is demonstrated on polystyrene spheres. The technique is then applied to the measurement of the refractive index, dry mass, volume, and density of red blood cells. This optical technique enables a simple and robust means to perform quantitative investigations of engineered and biological specimens in three dimensions using standard optical microscopes.

  6. Vertebrate blood cell volume increases with temperature: implications for aerobic activity

    Directory of Open Access Journals (Sweden)

    James F. Gillooly

    2014-04-01

    Full Text Available Aerobic activity levels increase with body temperature across vertebrates. Differences in these levels, from highly active to sedentary, are reflected in their ecology and behavior. Yet, the changes in the cardiovascular system that allow for greater oxygen supply at higher temperatures, and thus greater aerobic activity, remain unclear. Here we show that the total volume of red blood cells in the body increases exponentially with temperature across vertebrates, after controlling for effects of body size and taxonomy. These changes are accompanied by increases in relative heart mass, an indicator of aerobic activity. The results point to one way vertebrates may increase oxygen supply to meet the demands of greater activity at higher temperatures.

  7. High pressure operation of tubular solid oxide fuel cells and their intergration with gas turbines

    Energy Technology Data Exchange (ETDEWEB)

    Haynes, C.; Wepfer, W.J. [Georgia Institute of Technology, Atlanta, GA (United States)

    1996-12-31

    Fossil fuels continue to be used at a rate greater than that of their natural formation, and the current byproducts from their use are believed to have a detrimental effect on the environment (e.g. global warming). There is thus a significant impetus to have cleaner, more efficient fuel consumption alternatives. Recent progress has led to renewed vigor in the development of fuel cell technology, which has been shown to be capable of producing high efficiencies with relatively benign exhaust products. The tubular solid oxide fuel cell developed by Westinghouse Electric Corporation has shown significant promise. Modeling efforts have been and are underway to optimize and better understand this fuel cell technology. Thus far, the bulk of modeling efforts has been for operation at atmospheric pressure. There is now interest in developing high-efficiency integrated gas turbine/solid oxide fuel cell systems. Such operation of fuel cells would obviously occur at higher pressures. The fuel cells have been successfully modeled under high pressure operation and further investigated as integrated components of an open loop gas turbine cycle.

  8. In-Situ Continuous Production of Hydrogen Gas from Molasses Using Mutated Enterobacter aerogenes ADH43 for Fuel Cell Application

    Directory of Open Access Journals (Sweden)

    Z. Salam

    2011-11-01

    Full Text Available The performance of the continuous stirred tank reactor (CSTR for the in-situ production of hydrogen gas (H2 integrated with a polymer electrolyte membrane fuel cell (PEMFC was investigated. Facultative anaerobe fermentation of Enterobacter aerogenes ADH-43 was conducted into CSTR 50 rpm of agitation speed , 37 0C of temperature, 6.3 of pH, and 0.15, 0.3, 0.45, 0.60 h-1 of dilution rate. Bio-H2 produced was assesed after inserting it into a fuel cell to generate electricity and measuring voltages. The system was integrated with a ceramic membrane having 0.2 µm pore size for recycling the retentate cell into reactor and separating the permeate supernatant during the fermentation. The obtained H2 was purified from CO2 by absorption in Ca(OH2 solution prior to feed to PEMFC. The CSTR was initially operated on batch basis to increase the bacterial cell density to ensure the production of sufficient H2 and develop a feeding culture strategy for the continues operation mode. The result showed that the highest H2 production was achieved at continuous system resulted in 0.30 h-1 of optimum dilution rate. The maximum H2 volume of 9.76 l H2/l sugar , the yield of 1.84 mol H2/mol sugar, and the flow rate of 115 ml H2/min were obtained. Furthermore, colony count of 9.81 log cfu/ml, pH of 5.73, maximum electrical current of 0.38 Ampere, electrical power of 2.20 Watt, and electrical voltage of 5.75 volt after given resistance using LED of 25 ohm was also reached.

  9. Solar cells made by laser-induced diffusion directly from phosphine gas

    Science.gov (United States)

    Turner, G. B.; Tarrant, D.; Pollock, G.; Pressley, R.; Press, R.

    1981-12-01

    A method for making p-n junctions is presented, which is based on immersion in a transparent dopant gas followed by irradiation with a pulsed laser. An alexandrite laser operating at 0.73 micron is used where photolysis of the dopant gas PH3 does not occur, and multiple pulses of 2.2-2.7 J/sq cm are used to make Si solar cells with a total area efficiency up to 8.6% without benefit of anti-reflection coatings. Use of other gases should allow p-type doping, and the spatial localization inherent in the process could make the method applicable to structures such as interdigitated solar cells, transistors, and integrated circuits.

  10. Glucose concentration and medium volume influence cell viability and glycosaminoglycan synthesis in chondrocyte-seeded alginate constructs.

    Science.gov (United States)

    Heywood, Hannah K; Bader, Dan L; Lee, David A

    2006-12-01

    Increasing the thickness of tissue-engineered cartilage is associated with loss of chondrocyte viability and biosynthetic activity at the tissue center. Exceptionally high volumes of culture medium, however, can maintain cellularity and glycosaminoglycan synthesis throughout 4-mm-thick constructs. We hypothesized that glucose supplementation could replicate the augmentation of tissue formation achieved by medium volume. Chondrocyte-alginate constructs (40x10(6) cells/mL) were cultured for 14 days in 0.4-6.4 mL/10(-6) cells of either low- (5.1 mM) or high- (20.4 mM) glucose medium. Glucose was critical to chondrocyte viability, and glucose uptake increased significantly (P cells of low-glucose medium had a mass of 172 +/- 6.1 mg and glycosaminoglycan (GAG) content of 0.32 +/- 0.03 mg (mean +/- standard deviation). A 4-fold increase in medium volume increased the final construct mass by 44% and GAG content by 207%. An equivalent increase in glucose supply in the absence of volume change increased these parameters by just 10% and 73%, respectively. A similar trend was observed from 0.8 to 3.2 mL/10(-6) cells, when maximal values of construct GAG content and mass were obtained. Therefore, medium volume remains an important consideration for the optimal culture of tissue-engineered cartilage.

  11. Electrolyte Volume Effects on Electrochemical Performance and Solid Electrolyte Interphase in Si-Graphite/NMC Lithium-Ion Pouch Cells

    Energy Technology Data Exchange (ETDEWEB)

    An, Seong Jin; Li, Jianlin; Daniel, Claus; Meyer, Harry M.; Trask, Stephen E.; Polzin, Bryant J.; Wood, David L.

    2017-05-23

    This study aims to explore the correlations between electrolyte volume, electrochemical performance, and properties of the solid electrolyte interphase in pouch cells with Si-graphite composite anodes. The electrolyte is 1.2 M LiPF6 in ethylene carbonate:ethylmethyl carbonate with 10 wt.% fluoroethylene carbonate. Single layer pouch cells (100 mAh) were constructed with 15 wt.% Si-graphite / LiNi0.5Mn0.3CO0.2O2 electrodes. It is found that a minimum electrolyte volume factor of 3.1 times the total pore volume of cell components (cathode, anode, and separator) is needed for better cycling stability. Less electrolyte causes increases in ohmic and charge transfer resistances. Lithium dendrites are observed when the electrolyte volume factor is low. The resistances from the anodes become significant as the cells are discharged. Solid electrolyte interphase thickness grows as the electrolyte volume factor increases and is non-uniform after cycling.

  12. Differentiation of Bacillus anthracis from Bacillus cereus by gas chromatographic whole-cell fatty acid analysis.

    OpenAIRE

    Lawrence, D.; Heitefuss, S; Seifert, H S

    1991-01-01

    Three strains of Bacillus anthracis and seven strains of Bacillus cereus were grown on complex medium and on synthetic medium. Gas chromatographic analysis of whole-cell fatty acids of strains grown on complex medium gave nearly identical fatty acid patterns. Fatty acid patterns of strains grown on synthetic medium showed a high content of branched-chain fatty acids. Significant differences between the fatty acid patterns of the two species were found. Odd iso/anteiso fatty acid ratios were a...

  13. Optimizing the Performance of Porous Electrochemical Cells for Flue Gas Purification using the DOE method

    DEFF Research Database (Denmark)

    Andersen, Kjeld Bøhm; Nygaard, Frederik Berg; He, Zeming;

    2011-01-01

    The DOE model was used to improve the performance of cells for electrochemical gas purification. Three factors were chosen: the amount of graphite, the Lanthanum Strontium Manganate/Gadolinium-doped Cerium oxide weight % ratio, and the Lanthanum Strontium Manganate pre-calcination temperature (with......, that a change in a factor not only changes the performance property that one would expect, but also influence other properties....

  14. System Study on Hydrothermal Gasification Combined with a Hybrid Solid Oxide Fuel Cell Gas Turbine

    OpenAIRE

    Toonssen, Richard; Aravind, P.V.; Smit, Gerton; Woudstra, Nico; Verkooijen, Adrian

    2010-01-01

    Abstract The application of wet biomass in energy conversion systems is challenging, since in most conventional systems the biomass has to be dried. Drying can be very energy intensive especially when the biomass has a moisture content above 50 wt% on a wet basis. The combination of hydrothermal biomass gasification and a solid oxide fuel cell (SOFC) gas turbine (GT) hybrid system could be an efficient way to convert very wet biomass into electricity. Therefore, thermodynamic evalu...

  15. Observation of doubly-charged ions of francium isotopes extracted from a gas cell

    Science.gov (United States)

    Schury, P.; Wada, M.; Ito, Y.; Kaji, D.; Haba, H.; Hirayama, Y.; Kimura, S.; Koura, H.; MacCormick, M.; Miyatake, H.; Moon, J. Y.; Morimoto, K.; Morita, K.; Murray, I.; Ozawa, A.; Rosenbusch, M.; Reponen, M.; Takamine, A.; Tanaka, T.; Watanabe, Y. X.; Wollnik, H.

    2017-09-01

    Various isotopes of Ac, Ra, Fr, and Rn were produced by fusion-evaporation reactions using a 48Ca beam. The energetic ions were stopped in and extracted from a helium gas cell. The extracted ions were identified using a multi-reflection time-of-fight mass spectrograph. In all cases, it was observed that the predominant charge state for the extracted ions, including the alkali Fr, was 2+.

  16. Mean platelet volume and red cell distribution width levels in initial evaluation of panic disorder

    Directory of Open Access Journals (Sweden)

    Asoglu M

    2016-09-01

    Full Text Available Mehmet Asoglu,1 Mehmet Aslan,2 Okan Imre,1 Yuksel Kivrak,3 Oznur Akil,1 Emin Savik,4 Hasan Buyukaslan,5 Ulker Fedai,1 Abdurrahman Altındag6 1Department of Psychiatry, Faculty of Medicine, Harran University, Sanliurfa, 2Department of Internal Medicine, Faculty of Medicine, Yuzuncu Yil University, Van, 3Department of Psychiatry, Faculty of Medicine, Kafkas University, Kars, 4Department of Clinical Biochemistry, Faculty of Medicine, Harran University, 5Department of Emergency Medicine, Faculty of Medicine, Harran University, Sanliurfa, 6Department of Psychiatry, Faculty of Medicine, Gaziantep University, Gaziantep, Turkey Background: As the relationship between psychological stress and platelet activation has been widely studied in recent years, activated platelets lead to certain biochemical changes, which occur in the brain in patients with mental disorders. However, data relating to the mean platelet volume (MPV in patients with panic disorder (PD are both limited and controversial. Herein, we aimed to evaluate, for the first time, the red cell distribution width (RDW levels combined with MPV levels in patients with PD.Patients and methods: Between January 2012 and June 2015, data of 30 treatment-naïve patients (16 females, 14 males; mean age: 37±10 years; range: 18–59 years who were diagnosed with PD and 25 age- and sex-matched healthy volunteers (10 females, 15 males; mean age: 36±13 years; range: 18–59 years (control group were retrospectively analyzed. The white blood cell count (WBC, MPV, and RDW levels were measured in both groups.Results: The mean WBC, MPV, and RDW levels were 9,173.03±2,400.31/mm3, 8.19±1.13 fl, and 12.47±1.14%, respectively, in the PD group. These values were found to be 7,090.24±1,032.61, 6.85±0.67, and 11.63±0.85, respectively, in the healthy controls. The WBC, MPV, and RDW levels were significantly higher in the patients with PD compared to the healthy controls (P=0.001, P=0.001, and P=0

  17. Avidin-biotin-based approach to forming heterotypic cell clusters and cell sheets on a gas-permeable membrane

    Energy Technology Data Exchange (ETDEWEB)

    Hamon, M; Ozawa, T; Montagne, K; Kojima, N; Ishii, R; Sakai, Y [Institute of Industrial Science (IIS), University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan); Yamaguchi, S; Nagamune, T [Department of Bioengineering, Graduate School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Ushida, T, E-mail: mzh0026@auburn.edu [Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2011-09-15

    Implantation of sheet-like liver tissues is a promising method in hepatocyte-based therapies, because angiogenesis is expected to occur upon implantation from the surrounding tissues. In this context, we introduce here a new methodology for the formation of a functional thick hepatic tissue usable for cell sheet technology. First, we report the formation of composite tissue elements in suspension culture. Composite elements were composed of human hepatoma Hep G2 cells and mouse NIH/3T3 fibroblasts which are important modulators for thick-tissue formation. To overcome the very low attachment and organization capability between different cells in suspension, we synthesized a new cell-to-cell binding molecule based on the avidin-biotin binding system that we previously applied to attach hepatocytes on artificial substrata. This newly synthesized biotin-conjugated biocompatible anchoring molecule was inserted in the plasma membrane of both cell types. NIH/3T3 cells were further conjugated with avidin and incubated with biotin-presenting Hep G2 cells to form highly composite tissue elements. Then, we seeded those elements on highly gas-permeable membranes at their closest packing density to induce the formation of a thick, composite, functional hepatic tissue without any perfusion. This methodology could open a new way to engineer implantable thick liver tissue sheets where different cell types are spatially organized and well supplied with oxygen.

  18. Acquired cisplatin resistance in human ovarian A2780 cancer cells correlates with shift in taurine homeostasis and ability to volume regulate

    DEFF Research Database (Denmark)

    Sørensen, Belinda Halling; Thorsteinsdottir, Unnur Arna; Lambert, Ian Henry

    2014-01-01

    Cisplatin resistance is a major challenge in the treatment of cancer and develops through reduced drug accumulation and an increased ability to avoid drug-induced cell damage, cell shrinkage, and hence initiation of apoptosis. Uptake and release of the semiessential amino acid taurine contribute...... to cell volume homeostasis, and taurine has been reported to have antiapoptotic effects. Here we find that volume-sensitive taurine release in cisplatin-sensitive [wild-type (WT)] human ovarian cancer A2780 cells is reduced in the presence of the phospholipase A2 inhibitor bromenol lactone, the 5......-induced cell death in RES A2780 cells correlates with an increased accumulation of taurine, due to an increased taurine uptake and a concomitant impairment of the volume-sensitive taurine release pathway, as well an inability to reduce cell volume after osmotic cell swelling. Downregulation of volume...

  19. Solid-Oxide Fuel Cell Electrode Microstructures: Making Sense of the Internal Framework Affecting Gas Transport

    Science.gov (United States)

    Hanna, Jeffrey

    Optimal electrodes for solid-oxide fuel cells will combine high porosity for gas diffusion, high phase connectivity for ion and electron conduction, and high surface area for chemical and electrochemical reactions. Tracer-diffusion simulations are used to gain a better understanding of the interplay between microstructure and transport in porous materials. Results indicate that the coefficient of diffusion through a porous medium is a function of the details of the internal geometry (microscopic) and porosity (macroscopic). I report that current solid-oxide fuel cell electrodes produced from high-temperature sintering of ceramic powders severely hinder gas transport because the resulting structures are highly tortuous, complex three-dimensional networks. In addition, poor phase connectivities will assuredly limit ion and electron transport, as well as the density of active sites for power-producing reactions. With new access to a wide range of technologies, micro- and nano-fabrication capabilities, and high-performance materials, there is a new ability to engineer the fuel cell electrode architecture, optimizing the physical processes within, increasing performance, and greatly reducing cost per kilowatt. Even simple packed-sphere and inverse-opal architectures will increase gas diffusion by an order of magnitude, and provide a higher level of connectivity than traditional powder-based structures.

  20. Analytic determination of the effective thermal conductivity of PEM fuel cell gas diffusion layers

    Energy Technology Data Exchange (ETDEWEB)

    Sadeghi, E.; Bahrami, M.; Djilali, N. [Department of Mechanical Engineering and the Institute for Integrated Energy Systems, University of Victoria, Victoria, BC V8W 3P6 (Canada)

    2008-04-15

    Accurate information on the temperature field and associated heat transfer rates are particularly important in devising appropriate heat and water management strategies in proton exchange membrane (PEM) fuel cells. An important parameter in fuel cell performance analysis is the effective thermal conductivity of the gas diffusion layer (GDL). Estimation of the effective thermal conductivity is complicated because of the random nature of the GDL micro structure. In the present study, a compact analytical model for evaluating the effective thermal conductivity of fibrous GDLs is developed. The model accounts for conduction in both the solid fibrous matrix and in the gas phase; the spreading resistance associated with the contact area between overlapping fibers; gas rarefaction effects in microgaps; and salient geometric and mechanical features including fiber orientation and compressive forces due to cell/stack clamping. The model predictions are in good agreement with existing experimental data over a wide range of porosities. Parametric studies are performed using the proposed model to investigate the effect of bipolar plate pressure, aspect ratio, fiber diameter, fiber angle, and operating temperature. (author)