Science.gov

Sample records for saturation vapor pressure

  1. The temperature dependence of saturated vapor pressure over alkaline-earth metal pivaloyltrifluoroacetonate complexes

    NASA Astrophysics Data System (ADS)

    Efimova, Yu. A.; Abakumov, G. A.; Petrov, B. I.; Pochekutova, T. S.; Khamylov, V. K.

    2008-11-01

    The temperature dependences of saturated vapor pressure over M(PTA)2 · 15-crown-5, where M = Ca, Sr, or Ba and PTA is the pivaloyltrifluoroacetonate anion, were studied by the Knudsen effusion method, and the enthalpies of compound sublimation were calculated. Changes in volatility depending on the central metal atom were determined.

  2. Adipic and malonic acid aqueous solutions: surface tensions and saturation vapor pressures.

    PubMed

    Riipinen, Ilona; Koponen, Ismo K; Frank, Göran P; Hyvärinen, Antti-Pekka; Vanhanen, Joonas; Lihavainen, Heikki; Lehtinen, Kari E J; Bilde, Merete; Kulmala, Markku

    2007-12-20

    The surface tension of adipic aqueous solutions was measured as a function of temperature (T=278-313 K) and adipic acid mole fraction (X=0.000-0.003) using the Wilhelmy plate method. A parametrization fitted to these data is presented. The evaporation rates of binary water-malonic and water-adipic acid droplets were measured with a TDMA technique at different temperatures (T=293-300 K) and relative humidities (58-80%), and the saturation vapor pressures of subcooled liquid malonic and adipic acids were derived from the data using a binary evaporation model. The temperature dependence of the vapor pressures was obtained as least-squares fits to the derived vapor pressures: ln(Psat,l) (Pa)=220.2389-22634.96/T (K)-26.66767 ln T (K) for malonic acid and ln(Psat,l) (Pa)=140.6704-18230.97/T (K)-15.48011 ln T (K) for adipic acid. PMID:18044850

  3. Determination of saturation pressure and enthalpy of vaporization of semi-volatile aerosols: the integrated volume mentod

    EPA Science Inventory

    This study presents the integrated volume method for estimating saturation pressure and enthalpy of vaporization of a whole aerosol distribution. We measure the change of total volume of an aerosol distribution between a reference state and several heated states, with the heating...

  4. Rapid thermogravimetric measurements of boiling points and vapor pressure of saturated medium- and long-chain triglycerides.

    PubMed

    Goodrum, John W; Geller, Daniel P

    2002-08-01

    In developing compositional models for biomass-based diesel fuel extenders, volatility properties of medium- and long-chain saturated triglycerides are essential to predict the impact of low levels of these compounds in mixtures with short-chain triglycerides. A thermogravimetric analysis (TGA) method for rapid measurement of boiling points and vapor pressure was used to obtain data for four pure medium- and long-chain triglycerides. Normal boiling points at 1 atm and the temperature dependence of vapor pressure from 760 mm down to 25 mm Hg were obtained for trilaurin (C12:0), trimyristin (C14:0), tripalmitin (C16:0), and tristearin (C18:0). The data showed good agreement with the Clausius-Clapeyron model for temperature dependence of vapor pressure up to 1 atm pressure. The results of this study were consistent with those obtained using differential scanning calorimetry (DSC) and with data previously reported for reduced pressure. PMID:12137273

  5. Glow Discharge Formation over Water Surface at Saturated Water Vapor Pressure and Its Application to Wastewater Treatment

    NASA Astrophysics Data System (ADS)

    Sugama, Chie; Tochikubo, Fumiyoshi; Uchida, Satoshi

    2006-11-01

    With the aim of wastewater treatment using the active reaction of OH radicals generated in gas discharges, DC, low frequency (LF, 100 kHz) and RF (13.56 MHz) glow discharges were generated over the water surface at saturated water vapor pressure. Low-pressure glow discharge over the water surface has an advantage of uniform OH radical production near the water surface. A very stable and uniform glow discharge was obtained with an RF power source, whereas the discharges obtained with the DC and LF power sources were sometimes localized. The effective OH radical production was confirmed from the strong optical emission of OH(A{2}?+-X{2}\\Pi) near the water surface. The OH(A{2}?+-X{2}\\Pi) emission intensity near the water surface increased almost linearly with an increase in discharge power. N,N-Dimethyl- p-nitrosoaniline (RNO) solution as a persistent test pollutant was treated by RF glow discharge over the water surface. We confirmed that the RNO solution was certainly decolorized by OH radicals generated in the RF glow discharge. It was found that the degradation of target compounds by OH radicals was concentrated near the water surface in the solution because very slow diffusion of target compounds limited the reaction rate.

  6. Electrical conductivity measurements of aqueous boric acid at 25--350{degree}C at saturation vapor pressure. Final report

    SciTech Connect

    Ho, P.C.; Palmer, D.A.

    1995-09-01

    Electrical conductance measurements of aqueous boric acid solutions (15-110 g/kg-H{sub 2}O {equivalent_to} 0.251--1.815 mol/kg-H{sub 2}O) were measured over the temperature range 25 to 75 C at saturation vapor pressures in glass cells with parallel platinum electrodes. Sixteen series of measurements were made involving three samples of boric acid from different sources. Conductance measurements were also made at 15.5 and 30.5 g/kg-H{sub 2}O over the temperature range 100 to 350 C at 50 C intervals with a metallic cell fitted with concentric platinum electrodes. The specific conductances of H{sub 3}BO{sub 3} (aq)were calculated after correction for the conductance of the solvent (water) and are tabulated in this report. At the specific conditions requested in the project description, namely a concentration of 110 g/kg-H{sub 2}O and 65 C, the specific conductance of boric acid is 293.2 {+-} 1.8 microSiemens/cm based on duplicate measurements of four independent solutions. The results from these tests will be utilized by the Tokamak Physics Experimental Project (TPX).

  7. Vapor Pressure measurements for dichlorosilane 

    E-print Network

    Morris, Tony Knimbula

    1997-01-01

    trichlorosilane and silicon tetrachloride, or other chemicals which are not in the silane family. Accurate information about the vapor pressure is necessary in the production of these mixtures. Measurements reported previously for the vapor pressure of pure...

  8. The vapor pressures of explosives

    SciTech Connect

    Ewing, Robert G.; Waltman, Melanie J.; Atkinson, David A.; Grate, Jay W.; Hotchkiss, Peter

    2013-01-05

    The vapor pressures of many explosive compounds are extremely low and thus determining accurate values proves difficult. Many researchers, using a variety of methods, have measured and reported the vapor pressures of explosives compounds at single temperatures, or as a function of temperature using vapor pressure equations. There are large variations in reported vapor pressures for many of these compounds, and some errors exist within individual papers. This article provides a review of explosive vapor pressures and describes the methods used to determine them. We have compiled primary vapor pressure relationships traceable to the original citations and include the temperature ranges for which they have been determined. Corrected values are reported as needed and described in the text. In addition, after critically examining the available data, we calculate and tabulate vapor pressures at 25 °C.

  9. Enthalpies of Vaporization and Vapor Pressures of Some Deuterated Hydrocarbons. Liquid-Vapor Pressure Isotope Effects

    E-print Network

    Chickos, James S.

    Enthalpies of Vaporization and Vapor Pressures of Some Deuterated Hydrocarbons. Liquid-Vapor pressures as a function of temperature and enthalpies of vaporization of a series of both liquid and solid. The applicability of this technique is first demonstrated by reproducing the vapor pressure isotope effect

  10. To estimate vapor pressure easily

    SciTech Connect

    Yaws, C.L.; Yang, H.C. )

    1989-10-01

    Vapor pressures as functions of temperature for approximately 700 major organic chemical compounds are given. The tabulation also gives the temperature range for which the data are applicable. Minimum and maximum temperatures are denoted by TMIN and TMAX. The Antoine equation that correlates vapor pressure as a function of temperature is described. A representative comparison of calculated and actual data values for vapor pressure is shown for ethyl alcohol. The coefficient tabulation is based on both literature (experimental data) and estimated values.

  11. VAPORIZATION THERMODYNAMICS OF KCl. COMBINING VAPOR PRESSURE AND GRAVIMETRIC DATA

    E-print Network

    Rudnyi, Evgenii B.

    1 VAPORIZATION THERMODYNAMICS OF KCl. COMBINING VAPOR PRESSURE AND GRAVIMETRIC DATA Rudnyi E of thermodynamic properties of the vapor and the vaporization process, coupling pressure measurements. INTRODUCTION The vapor pressure of a substance is an important system property in many applications. Its value

  12. 40 CFR 796.1950 - Vapor pressure.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...with relatively low vapor pressures, high adsorptivity onto...chemicals with high vapor pressures or with low water solubility...and are prime candidates for atmospheric oxidation and photolysis...and water. (iii) Vapor pressure data are an important...

  13. 40 CFR 796.1950 - Vapor pressure.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...with relatively low vapor pressures, high adsorptivity onto...chemicals with high vapor pressures or with low water solubility...and are prime candidates for atmospheric oxidation and photolysis...and water. (iii) Vapor pressure data are an important...

  14. 40 CFR 796.1950 - Vapor pressure.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...with relatively low vapor pressures, high adsorptivity onto...chemicals with high vapor pressures or with low water solubility...and are prime candidates for atmospheric oxidation and photolysis...and water. (iii) Vapor pressure data are an important...

  15. 40 CFR 796.1950 - Vapor pressure.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...with relatively low vapor pressures, high adsorptivity onto...chemicals with high vapor pressures or with low water solubility...and are prime candidates for atmospheric oxidation and photolysis...and water. (iii) Vapor pressure data are an important...

  16. 40 CFR 796.1950 - Vapor pressure.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...with relatively low vapor pressures, high adsorptivity onto...chemicals with high vapor pressures or with low water solubility...and are prime candidates for atmospheric oxidation and photolysis...and water. (iii) Vapor pressure data are an important...

  17. Precision ozone vapor pressure measurements

    NASA Technical Reports Server (NTRS)

    Hanson, D.; Mauersberger, K.

    1985-01-01

    The vapor pressure above liquid ozone has been measured with a high accuracy over a temperature range of 85 to 95 K. At the boiling point of liquid argon (87.3 K) an ozone vapor pressure of 0.0403 Torr was obtained with an accuracy of + or - 0.7 percent. A least square fit of the data provided the Clausius-Clapeyron equation for liquid ozone; a latent heat of 82.7 cal/g was calculated. High-precision vapor pressure data are expected to aid research in atmospheric ozone measurements and in many laboratory ozone studies such as measurements of cross sections and reaction rates.

  18. Vapor pressure measured with inflatable plastic bag

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Deflated plastic bag in a vacuum chamber measures initial low vapor pressures of materials. The bag captures the test sample vapors and visual observation of the vapor-inflated bag under increasing external pressures yields pertinent data.

  19. Vapor Pressure Measurements in a Closed System

    ERIC Educational Resources Information Center

    Iannone, Mark

    2006-01-01

    An alternative method that uses a simple apparatus to measure vapor pressure versus temperature in a closed system, in which the total pressure is the vapor pressure of the liquid sample, is described. The use of this apparatus gives students a more direct picture of vapor pressure than the isoteniscope method and results have generally been quite…

  20. Enthalpy of Vaporization and Vapor Pressures: An Inexpensive Apparatus

    ERIC Educational Resources Information Center

    Battino, Rubin; Dolson, David A.; Hall, Michael A.; Letcher, Trevor M.

    2007-01-01

    A simple and inexpensive method to determine the enthalpy of vaporization of liquids by measuring vapor pressure as a function of temperature is described. The vapor pressures measured with the stopcock cell were higher than the literature values and those measured with the sidearm rubber septum cell were both higher and lower than literature…

  1. VAPOR PRESSURES AND HEATS OF VAPORIZATION OF PRIMARY COAL TARS

    SciTech Connect

    Eric M. Suuberg; Vahur Oja

    1997-07-01

    This project had as its main focus the determination of vapor pressures of coal pyrolysis tars. It involved performing measurements of these vapor pressures and from them, developing vapor pressure correlations suitable for use in advanced pyrolysis models (those models which explicitly account for mass transport limitations). This report is divided into five main chapters. Each chapter is a relatively stand-alone section. Chapter A reviews the general nature of coal tars and gives a summary of existing vapor pressure correlations for coal tars and model compounds. Chapter B summarizes the main experimental approaches for coal tar preparation and characterization which have been used throughout the project. Chapter C is concerned with the selection of the model compounds for coal pyrolysis tars and reviews the data available to us on the vapor pressures of high boiling point aromatic compounds. This chapter also deals with the question of identifying factors that govern the vapor pressures of coal tar model materials and their mixtures. Chapter D covers the vapor pressures and heats of vaporization of primary cellulose tars. Chapter E discusses the results of the main focus of this study. In summary, this work provides improved understanding of the volatility of coal and cellulose pyrolysis tars. It has resulted in new experimentally verified vapor pressure correlations for use in pyrolysis models. Further research on this topic should aim at developing general vapor pressure correlations for all coal tars, based on their molecular weight together with certain specific chemical characteristics i.e. hydroxyl group content.

  2. 40 CFR 796.1950 - Vapor pressure.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 33 2013-07-01 2013-07-01 false Vapor pressure. 796.1950 Section 796... (CONTINUED) CHEMICAL FATE TESTING GUIDELINES Physical and Chemical Properties § 796.1950 Vapor pressure. (a... the vapor pressure of chemical and on environmental conditions which influence diffusion from...

  3. 40 CFR 796.1950 - Vapor pressure.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 31 2010-07-01 2010-07-01 true Vapor pressure. 796.1950 Section 796... (CONTINUED) CHEMICAL FATE TESTING GUIDELINES Physical and Chemical Properties § 796.1950 Vapor pressure. (a... the vapor pressure of chemical and on environmental conditions which influence diffusion from...

  4. 40 CFR 796.1950 - Vapor pressure.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 32 2014-07-01 2014-07-01 false Vapor pressure. 796.1950 Section 796... (CONTINUED) CHEMICAL FATE TESTING GUIDELINES Physical and Chemical Properties § 796.1950 Vapor pressure. (a... the vapor pressure of chemical and on environmental conditions which influence diffusion from...

  5. 40 CFR 796.1950 - Vapor pressure.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 32 2011-07-01 2011-07-01 false Vapor pressure. 796.1950 Section 796... (CONTINUED) CHEMICAL FATE TESTING GUIDELINES Physical and Chemical Properties § 796.1950 Vapor pressure. (a... the vapor pressure of chemical and on environmental conditions which influence diffusion from...

  6. 40 CFR 796.1950 - Vapor pressure.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 33 2012-07-01 2012-07-01 false Vapor pressure. 796.1950 Section 796... (CONTINUED) CHEMICAL FATE TESTING GUIDELINES Physical and Chemical Properties § 796.1950 Vapor pressure. (a... the vapor pressure of chemical and on environmental conditions which influence diffusion from...

  7. Non-LTE dust nucleation in sub-saturated vapors

    E-print Network

    Davide Lazzati

    2007-11-09

    We use the kinetic theory of nucleation to explore the properties of dust nucleation in sub-saturated vapors. Due to radiation losses, the sub-critical clusters have a smaller temperature compared to their vapor. This alters the dynamical balance between attachment and detachment of monomers, allowing for stable nucleation of grains in vapors that are sub-saturated for their temperature. We find this effect particularly important at low densities and in the absence of a strong background radiation field. We find new conditions for stable nucleation in the n-T phase diagram. The nucleation in the non-LTE regions is likely to be at much slower rate than in the super-saturated vapors. We evaluate the nucleation rate, warning the reader that it does depend on poorly substantiated properties of the macro-molecules assumed in the computation. On the other hand, the conditions for nucleation depend only on the properties of the large stable grains and are more robust. We finally point out that this mechanism may be relevant in the early universe as an initial dust pollution mechanism, since once the interstellar medium is polluted with dust, mantle growth is likely to be dominant over non-LTE nucleation in the diffuse medium.

  8. Saturated Vapour Pressure and Refrigeration - Part I

    ERIC Educational Resources Information Center

    Bunker, C. A.

    1973-01-01

    The first part of a two-part article describes an experimental approach that can be used in teaching the concept of saturated vapour pressure. This leads to a discussion of refrigeration cycles in the second part of the article. (JR)

  9. Film boiling of saturated liquid flowing upward through a heated tube : high vapor quality range

    E-print Network

    Laverty, W. F.

    1964-01-01

    Film boiling of saturated liquid flowing upward through a uniformly heated tube has been studied for the case in which pure saturated liquid enters the tube and nearly saturated vapor is discharged. Since a previous study ...

  10. Multicomponent fuel vaporization at high pressures.

    SciTech Connect

    Torres, D. J.; O'Rourke, P. J.

    2002-01-01

    We extend our multicomponent fuel model to high pressures using a Peng-Robinson equation of state, and implement the model into KIVA-3V. Phase equilibrium is achieved by equating liquid and vapor fugacities. The latent heat of vaporization and fuel enthalpies are also corrected for at high pressures. Numerical simulations of multicomponent evaporation are performed for single droplets for a diesel fuel surrogate at different pressures.

  11. Vapor Pressures and Vaporization Enthalpies of a Series of Dialkyl Phthalates by Correlation Gas Chromatography

    E-print Network

    Chickos, James S.

    Vapor Pressures and Vaporization Enthalpies of a Series of Dialkyl Phthalates by Correlation Gas: Experimental vapor pressures, vaporization, fusion and sublimation enthalpies of a number of dialkyl, dibutyl phthalate, and bis(2-ethylhexyl) phthalate. New vaporization enthalpies and liquid vapor pressure

  12. The Vaporization Enthalpies and Vapor Pressures of Some Primary Amines of Pharmaceutical Importance by Correlation Gas

    E-print Network

    Chickos, James S.

    The Vaporization Enthalpies and Vapor Pressures of Some Primary Amines of Pharmaceutical Importance Information ABSTRACT: Vapor pressures, vaporization, and sublimation enthalpies of several pharmaceuticals.5 ± 2.1); p(cr)/Pa = 0.12 ± 0.04]. Vapor pressure equations also derived from vapor pressureretention

  13. The vapor pressure of iron pentacarbonyl

    NASA Technical Reports Server (NTRS)

    Gilbert, A. G.; Sulzmann, K. G. P.

    1974-01-01

    Vapor pressure measurements have been made on pure iron pentacarbonyl between +31 and -19 C. The experimental results may be expressed by the logarithm of pressure (mm Hg) to the base 10 equals -(2096.7 K/T) + 8.4959, which corresponds to a heat of vaporization for the liquid carbonyl of delta H ? (9.588 plus or minus 0.12) kcal/mole. This result confirms and extends the earlier measurements made by Trautz and Badstuebner between 0 and 140 C. The need for careful purification of commercially available iron pentacarbonyl is emphasized, particularly for establishing the correct vapor pressure below 45 C.

  14. An Interpolation Method for Obtaining Thermodynamic Properties Near Saturated Liquid and Saturated Vapor Lines

    NASA Technical Reports Server (NTRS)

    Nguyen, Huy H.; Martin, Michael A.

    2004-01-01

    The two most common approaches used to formulate thermodynamic properties of pure substances are fundamental (or characteristic) equations of state (Helmholtz and Gibbs functions) and a piecemeal approach that is described in Adebiyi and Russell (1992). This paper neither presents a different method to formulate thermodynamic properties of pure substances nor validates the aforementioned approaches. Rather its purpose is to present a method to generate property tables from existing property packages and a method to facilitate the accurate interpretation of fluid thermodynamic property data from those tables. There are two parts to this paper. The first part of the paper shows how efficient and usable property tables were generated, with the minimum number of data points, using an aerospace industry standard property package. The second part describes an innovative interpolation technique that has been developed to properly obtain thermodynamic properties near the saturated liquid and saturated vapor lines.

  15. Vaporization Enthalpy and Vapor Pressure of Valproic Acid by Correlation Gas Chromatography

    E-print Network

    Chickos, James S.

    Vaporization Enthalpy and Vapor Pressure of Valproic Acid by Correlation Gas Chromatography Joe A-propylpentanoic acid) is reported, and the vapor pressures of a series on aliphatic carboxylic acids are used to evaluate its vapor pressure as a function of temperature. The vaporization enthalpy was derived

  16. Hypothetical Thermodynamic Properties. Subcooled Vaporization Enthalpies and Vapor Pressures of Polyaromatic Heterocycles and Related Compounds

    E-print Network

    Chickos, James S.

    Hypothetical Thermodynamic Properties. Subcooled Vaporization Enthalpies and Vapor Pressures The vaporization enthalpies and vapor pressures of the liqiud phase from T ) 298.15 K to T ) 500 K of a series in the literature was measured on a hydrated form. Vapor pressures and normal boiling temperatures for the liquid

  17. A survey and new measurements of ice vapor pressure at temperatures between 170 and 250K

    SciTech Connect

    Marti, J.; Mauersberger, K. )

    1993-03-05

    Saturated vapor pressures of ice at temperatures below 200K have become more important since the discovery of ice clouds in the polar stratosphere and upper mesosphere. Direct measurements of ice vapor pressures at such low temperatures are sparse and unreliable. This paper summarizes published vapor pressure data and presents new measurements at temperatures between 170 and 250K extending the range of measured ice vapor pressures by three orders of magnitude. A simple empirical vapor pressure equation is derived which permits prediction of vapor pressures between 170K and the triple point of water, with an accuracy of about 2%: log P = A/T + B, with A = [minus]2663.5 [+-] 0.8, B = 12.537 [+-] 0.011, P in Pa and T in kelvins. Predictions by this empirical equation agree, within experimental uncertainty, with the most reliable equation derived from thermodynamic principles. 22 refs., 2 figs., 1 tab.

  18. Clausius-Clapeyron Equation and Saturation Vapour Pressure: Simple Theory Reconciled with Practice

    ERIC Educational Resources Information Center

    Koutsoyiannis, Demetris

    2012-01-01

    While the Clausius-Clapeyron equation is very important as it determines the saturation vapour pressure, in practice it is replaced by empirical, typically Magnus-type, equations which are more accurate. It is shown that the reduced accuracy reflects an inconsistent assumption that the latent heat of vaporization is constant. Not only is this…

  19. Vapor pressures of acetylene at low temperatures

    NASA Technical Reports Server (NTRS)

    Masterson, C. M.; Allen, John E., Jr.; Kraus, G. F.; Khanna, R. K.

    1990-01-01

    The atmospheres of many of the outer planets and their satellites contain a large number of hydrocarbon species. In particular, acetylene (C2H2) has been identified at Jupiter, Saturn and its satellite Titan, Uranus and Neptune. In the lower atmospheres of these planets, where colder temperatures prevail, the condensation and/or freezing of acetylene is probable. In order to obtain accurate models of the acetylene in these atmospheres, it is necessary to have a complete understanding of its vapor pressures at low temperatures. Vapor pressures at low temperatures for acetylene are being determined. The vapor pressures are measured with two different techniques in order to cover a wide range of temperatures and pressures. In the first, the acetylene is placed in a sample tube which is immersed in a low temperature solvent/liquid nitrogen slush bath whose temperature is measured with a thermocouple. The vapor pressure is then measured directly with a capacitance manometer. For lower pressures, a second technique which was called the thin-film infrared method (TFIR) was developed. It involves measuring the disappearance rate of a thin film of acetylene at a particular temperature. The spectra are then analyzed using previously determined extinction coefficient values, to determine the disappearance rate R (where R = delta n/delta t, the number of molecules that disappear per unit time). This can be related to the vapor pressure directly. This technique facilitates measurement of the lower temperatures and pressures. Both techniques have been calibrated using CO2, and have shown good agreement with the existing literature data.

  20. Vaporization Enthalpies and Vapor Pressures of Two Insecticide Components, Muscalure and Empenthrin, by Correlation Gas

    E-print Network

    Chickos, James S.

    Vaporization Enthalpies and Vapor Pressures of Two Insecticide Components, Muscalure and Empenthrin: The vaporization enthalpies at T/K = 298.15 and vapor pressures from T/K = (298.15 to Tnb (normal boiling. Vaporization enthalpies of [(114.4 ± 1.0) and (114.5 ± 1.0)] kJ·mol-1 and vapor pressures, p/Pa = [(1.2 ± 0

  1. An Interpolation Method for Obtaining Thermodynamic Properties Near Saturated Liquid and Saturated Vapor Lines

    NASA Technical Reports Server (NTRS)

    Nguyen, Huy H.; Martin, Michael A.

    2003-01-01

    The availability and proper utilization of fluid properties is of fundamental importance in the process of mathematical modeling of propulsion systems. Real fluid properties provide the bridge between the realm of pure analytiis and empirical reality. The two most common approaches used to formulate thermodynamic properties of pure substances are fundamental (or characteristic) equations of state (Helmholtz and Gibbs functions) and a piecemeal approach that is described, for example, in Adebiyi and Russell (1992). This paper neither presents a different method to formulate thermodynamic properties of pure substances nor validates the aforementioned approaches. Rather its purpose is to present a method to be used to facilitate the accurate interpretation of fluid thermodynamic property data generated by existing property packages. There are two parts to this paper. The first part of the paper shows how efficient and usable property tables were generated, with the minimum number of data points, using an aerospace industry standard property package (based on fundamental equations of state approach). The second part describes an innovative interpolation technique that has been developed to properly obtain thermodynamic properties near the saturated liquid and saturated vapor lines.

  2. Vapor Pressures and Vaporization, Sublimation, and Fusion Enthalpies of Some Fatty Acids

    E-print Network

    Chickos, James S.

    Vapor Pressures and Vaporization, Sublimation, and Fusion Enthalpies of Some Fatty Acids Joe A vapor pressures of both the subcooled liquid and solid state for those materials that are solids at T/K = 298.15. Equations for the prediction of vapor pressure from T/K = 298.15 to the boiling temperature

  3. Hypothetical Thermodynamic Properties. Subcooled Vaporization Enthalpies and Vapor Pressures of Polyaromatic Hydrocarbons

    E-print Network

    Chickos, James S.

    Hypothetical Thermodynamic Properties. Subcooled Vaporization Enthalpies and Vapor Pressures and liquid vapor pressures from T ) 298.15 K to T ) 510 K of a series of polyaromatic hydrocarbons have been of a thermochemical cycle, and agreement is within the combined experimental uncertainties. Vapor pressures

  4. MISTING OF LOW VAPOR PRESSURE HALOCARBONS

    EPA Science Inventory

    The paper gives results of a laboratory-scale study of the use of misting systems to provide total-flood fire protection with lower vapor pressure halocarbons. (NOTE: Several candidate Halon 1301 replacements with a low ozone-depletion potential have higher boiling points (usuall...

  5. 46 CFR 154.426 - Design vapor pressure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Design vapor pressure. 154.426 Section...VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Membrane Tanks § 154.426 Design vapor pressure. The Po of a...

  6. 46 CFR 154.419 - Design vapor pressure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Design vapor pressure. 154.419 Section...VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Integral Tanks § 154.419 Design vapor pressure. The Po of...

  7. Heating of a fully saturated darcian half-space: Pressure generation, fluid expulsion, and phase change

    USGS Publications Warehouse

    Delaney, P.

    1984-01-01

    Analytical solutions are developed for the pressurization, expansion, and flow of one- and two-phase liquids during heating of fully saturated and hydraulically open Darcian half-spaces subjected to a step rise in temperature at its surface. For silicate materials, advective transfer is commonly unimportant in the liquid region; this is not always the case in the vapor region. Volume change is commonly more important than heat of vaporization in determining the position of the liquid-vapor interface, assuring that the temperatures cannot be determined independently of pressures. Pressure increases reach a maximum near the leading edge of the thermal front and penetrate well into the isothermal region of the body. Mass flux is insensitive to the hydraulic properties of the half-space. ?? 1984.

  8. Vapor Pressure, Vapor Composition and Fractional Vaporization of High Temperature Lavas on Io

    NASA Technical Reports Server (NTRS)

    Fegley, B., Jr.; Schaefer, L.; Kargel, J. S.

    2003-01-01

    Observations show that Io's atmosphere is dominated by SO2 and other sulfur and sulfur oxide species, with minor amounts of Na, K, and Cl gases. Theoretical modeling and recent observations show that NaCl, which is produced volcanically, is a constituent of the atmosphere. Recent Galileo, HST and ground-based observations show that some volcanic hot spots on Io have extremely high temperatures, in the range 1400-1900 K. At similar temperatures in laboratory experiments, molten silicates and oxides have significant vapor pressures of Na, K, SiO, Fe, Mg, and other gases. Thus vaporization of these species from high temperature lavas on Io seems likely. We therefore modeled the vaporization of silicate and oxide lavas suggested for Io. Our results for vapor chemistry are reported here. The effects of fractional vaporization on lava chemistry are given in a companion abstract by Kargel et al.

  9. Salinity gradient power: utilizing vapor pressure differences.

    PubMed

    Olsson, M; Wick, G L; Isaacs, J D

    1979-10-26

    By utilizing the vapor pressure difference between high-salinity and lowsalinity wvater, one can obtain power from the gradients of salinity. This scheme eliminates the major problems associated with conversion methods in which membranes are used. The method we tested gave higher conversion efficiencies than membrane methods. Furthermore, hardware and techniques being developed for ocean thermal energy conversion may be applied to this approach to salinity gradient energy conversion. PMID:17809370

  10. On the propagation of a coupled saturation and pressure front

    SciTech Connect

    Vasco, D. W.

    2010-12-01

    Using an asymptotic technique, valid for a medium with smoothly varying heterogeneity, I derive an expression for the velocity of a propagating, coupled saturation and pressure front. Due to the nonlinearity of the governing equations, the velocity of the propagating front depends upon the magnitude of the saturation and pressure changes across the front in addition to the properties of the medium. Thus, the expression must be evaluated in conjunction with numerical reservoir simulation. The propagation of the two-phase front is governed by the background saturation distribution, the saturation-dependent component of the fluid mobility, the porosity, the permeability, the capillary pressure function, the medium compressibility, and the ratio of the slopes of the relative permeability curves. Numerical simulation of water injection into a porous layer saturated with a nonaqueous phase liquid indicates that two modes of propagation are important. The fastest mode of propagation is a pressure-dominated disturbance that travels through the saturated layer. This is followed, much later, by a coupled mode with a large saturation change. These two modes are also observed in a simulation using a heterogeneous porous layer. A comparison between the propagation times estimated from the results of the numerical simulation and predictions from the asymptotic expression indicates overall agreement.

  11. Saturation of atomic transitions using sub-wavelength diameter tapered optical fibers in rubidium vapor

    E-print Network

    Jones, D E; Pittman, T B

    2014-01-01

    We experimentally investigate ultralow-power saturation of the rubidium D2 transitions using a tapered optical fiber (TOF) suspended in a warm Rb vapor. A direct comparison of nonlinear absorption measurements for the TOF system with those obtained in a standard free-space vapor cell system highlights the differences in saturation behavior for the two systems. The effects of hyperfine pumping in the TOF system are found to be minimized due to the short atomic transit times through the highly confined evanescent optical mode guided by the TOF. The TOF system data is well-fit by a relatively simple empirical absorption model that indicates nanoWatt-level saturation powers.

  12. High-accuracy measurements of the vapor pressure of ice referenced to the triple point

    NASA Astrophysics Data System (ADS)

    Bielska, Katarzyna; Havey, Daniel K.; Scace, Gregory E.; Lisak, Daniel; Harvey, Allan H.; Hodges, Joseph T.

    2013-12-01

    vapor pressure of hexagonal (Ih) water ice was measured over the temperature range 175 K to 253.4 K and referenced to the value at the triple point of water. This experiment combined a highly accurate humidity generation system containing an ice-coated saturator (millikelvin-level temperature control) to provide humidified streams of nitrogen to a cavity-enhanced laser absorption spectrometer. The measured ice vapor pressures had relative standard uncertainties ranging from 0.4% to 0.7% over the entire temperature range. We demonstrate that these measurements validate thermodynamic correlations for ice vapor pressure based on integration of the Clapeyron equation. Moreover, they also indicate that some commonly used vapor pressure correlations are inaccurate and should be avoided.

  13. A Multiscale Simulator for Low Pressure Chemical Vapor Deposition

    E-print Network

    A Multiscale Simulator for Low Pressure Chemical Vapor Deposition Matthias K. Gobbert Institute-6206 ABSTRACT An integrated simulator for chemical vapor deposition is introduced. In addition to a reactor

  14. Oxidation of trichloroethylene, toluene, and ethanol vapors by a partially saturated permeable reactive barrier

    NASA Astrophysics Data System (ADS)

    Mahmoodlu, Mojtaba G.; Hassanizadeh, S. Majid; Hartog, Niels; Raoof, Amir

    2014-08-01

    The mitigation of volatile organic compound (VOC) vapors in the unsaturated zone largely relies on the active removal of vapor by ventilation. In this study we considered an alternative method involving the use of solid potassium permanganate to create a horizontal permeable reactive barrier for oxidizing VOC vapors. Column experiments were carried out to investigate the oxidation of trichloroethylene (TCE), toluene, and ethanol vapors using a partially saturated mixture of potassium permanganate and sand grains. Results showed a significant removal of VOC vapors due to the oxidation. We found that water saturation has a major effect on the removal capacity of the permeable reactive layer. We observed a high removal efficiency and reactivity of potassium permanganate for all target compounds at the highest water saturation (Sw = 0.6). A change in pH within the reactive layer reduced oxidation rate of VOCs. The use of carbonate minerals increased the reactivity of potassium permanganate during the oxidation of TCE vapor by buffering the pH. Reactive transport of VOC vapors diffusing through the permeable reactive layer was modeled, including the pH effect on the oxidation rates. The model accurately described the observed breakthrough curve of TCE and toluene vapors in the headspace of the column. However, miscibility of ethanol in water in combination with produced water during oxidation made the modeling results less accurate for ethanol. A linear relationship was found between total oxidized mass of VOC vapors per unit volume of permeable reactive layer and initial water saturation. This behavior indicates that pH changes control the overall reactivity and longevity of the permeable reactive layer during oxidation of VOCs. The results suggest that field application of a horizontal permeable reactive barrier can be a viable technology against upward migration of VOC vapors through the unsaturated zone.

  15. Prevalence of Sensor Saturation in Wheelchair Seat Interface Pressure Mapping.

    PubMed

    Wininger, Michael; Crane, Barbara A

    2015-01-01

    Pressure mapping is a frequently used tool with great power to provide information about the forces between a patient and a wheelchair seat. One widely recognized limitation to this paradigm is the possibility of data loss due to sensor saturation. In this study, we seek to quantify and describe the saturation observed in the measurement of interface pressures of wheelchair users. We recorded approximately two minutes of interface pressure data from 22 elderly wheelchair users (11M/11F, 80 ± 10 years) and found that 4.7% of data frames had 1 saturated sensor, and 9.0% had more than one saturated sensor, for a total of 13.7% of all frames of data. Data from three of the 22 subjects (13.6%) were substantially affected by the persistent presence of saturated sensors. We conclude that for this population of elderly wheelchair users, sensor saturation may be a concern and should be factored properly into study design a priori. PMID:26132350

  16. 46 CFR 154.451 - Design vapor pressure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Design vapor pressure. 154.451 Section 154.451 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Independent Tank Type C and Process Pressure Vessels § 154.451 Design vapor pressure. The Po (kPa) of...

  17. 46 CFR 154.451 - Design vapor pressure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Design vapor pressure. 154.451 Section 154.451 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Independent Tank Type C and Process Pressure Vessels § 154.451 Design vapor pressure. The Po (kPa) of...

  18. 46 CFR 154.451 - Design vapor pressure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Design vapor pressure. 154.451 Section 154.451 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Independent Tank Type C and Process Pressure Vessels § 154.451 Design vapor pressure. The Po (kPa) of...

  19. 46 CFR 154.451 - Design vapor pressure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Design vapor pressure. 154.451 Section 154.451 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Independent Tank Type C and Process Pressure Vessels § 154.451 Design vapor pressure. The Po (kPa) of...

  20. 46 CFR 154.451 - Design vapor pressure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Design vapor pressure. 154.451 Section 154.451 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Independent Tank Type C and Process Pressure Vessels § 154.451 Design vapor pressure. The Po (kPa) of...

  1. 46 CFR 154.451 - Design vapor pressure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Design vapor pressure. 154.451 Section 154.451 Shipping...Equipment Independent Tank Type C and Process Pressure Vessels § 154.451 Design vapor pressure. The Po (kPa) of an...

  2. 46 CFR 154.451 - Design vapor pressure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Design vapor pressure. 154.451 Section 154.451 Shipping...Equipment Independent Tank Type C and Process Pressure Vessels § 154.451 Design vapor pressure. The Po (kPa) of an...

  3. 46 CFR 154.451 - Design vapor pressure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Design vapor pressure. 154.451 Section 154.451 Shipping...Equipment Independent Tank Type C and Process Pressure Vessels § 154.451 Design vapor pressure. The Po (kPa) of an...

  4. 46 CFR 154.451 - Design vapor pressure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Design vapor pressure. 154.451 Section 154.451 Shipping...Equipment Independent Tank Type C and Process Pressure Vessels § 154.451 Design vapor pressure. The Po (kPa) of an...

  5. 46 CFR 154.451 - Design vapor pressure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Design vapor pressure. 154.451 Section 154.451 Shipping...Equipment Independent Tank Type C and Process Pressure Vessels § 154.451 Design vapor pressure. The Po (kPa) of an...

  6. Fuel Vapor Pressures and the Relation of Vapor Pressure to the Preparation of Fuel for Combustion in Fuel Injection Engines

    NASA Technical Reports Server (NTRS)

    Joachim, William F; Rothrock, A M

    1930-01-01

    This investigation on the vapor pressure of fuels was conducted in connection with the general research on combustion in fuel injection engines. The purpose of the investigation was to study the effects of high temperatures such as exist during the first stages of injection on the vapor pressures of several fuels and certain fuel mixtures, and the relation of these vapor pressures to the preparation of the fuel for combustion in high-speed fuel injection engines.

  7. 40 CFR 63.165 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 63.165...165 Standards: Pressure relief devices in gas/vapor service. (a...pressure releases, each pressure relief device in gas/vapor service shall...

  8. 40 CFR 264.1054 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 264...1054 Standards: Pressure relief devices in gas/vapor service. (a...pressure releases, each pressure relief device in gas/vapor service shall...

  9. 40 CFR 63.165 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 63.165...165 Standards: Pressure relief devices in gas/vapor service. (a...pressure releases, each pressure relief device in gas/vapor service shall...

  10. 40 CFR 61.242-4 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 61.242-4...242-4 Standards: Pressure relief devices in gas/vapor service. (a...pressure releases, each pressure relief device in gas/vapor service shall...

  11. 40 CFR 265.1054 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 265...1054 Standards: Pressure relief devices in gas/vapor service. (a...pressure releases, each pressure relief device in gas/vapor service shall...

  12. 40 CFR 264.1054 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 264...1054 Standards: Pressure relief devices in gas/vapor service. (a...pressure releases, each pressure relief device in gas/vapor service shall...

  13. 40 CFR 60.482-4 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 60.482-4...482-4 Standards: Pressure relief devices in gas/vapor service. (a...pressure releases, each pressure relief device in gas/vapor service shall...

  14. 40 CFR 265.1054 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 265...1054 Standards: Pressure relief devices in gas/vapor service. (a...pressure releases, each pressure relief device in gas/vapor service shall...

  15. 40 CFR 60.482-4 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 60.482-4...482-4 Standards: Pressure relief devices in gas/vapor service. (a...pressure releases, each pressure relief device in gas/vapor service shall...

  16. 40 CFR 60.482-4 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 60.482-4...482-4 Standards: Pressure relief devices in gas/vapor service. (a...pressure releases, each pressure relief device in gas/vapor service shall...

  17. 40 CFR 63.165 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 63.165...165 Standards: Pressure relief devices in gas/vapor service. (a...pressure releases, each pressure relief device in gas/vapor service shall...

  18. 40 CFR 265.1054 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 265...1054 Standards: Pressure relief devices in gas/vapor service. (a...pressure releases, each pressure relief device in gas/vapor service shall...

  19. 40 CFR 61.242-4 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 61.242-4...242-4 Standards: Pressure relief devices in gas/vapor service. (a...pressure releases, each pressure relief device in gas/vapor service shall...

  20. 40 CFR 264.1054 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 264...1054 Standards: Pressure relief devices in gas/vapor service. (a...pressure releases, each pressure relief device in gas/vapor service shall...

  1. 40 CFR 264.1054 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 264...1054 Standards: Pressure relief devices in gas/vapor service. (a...pressure releases, each pressure relief device in gas/vapor service shall...

  2. 40 CFR 63.165 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 63.165...165 Standards: Pressure relief devices in gas/vapor service. (a...pressure releases, each pressure relief device in gas/vapor service shall...

  3. 40 CFR 60.482-4 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 60.482-4...482-4 Standards: Pressure relief devices in gas/vapor service. (a...pressure releases, each pressure relief device in gas/vapor service shall...

  4. 40 CFR 265.1054 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 265...1054 Standards: Pressure relief devices in gas/vapor service. (a...pressure releases, each pressure relief device in gas/vapor service shall...

  5. 40 CFR 265.1054 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 265...1054 Standards: Pressure relief devices in gas/vapor service. (a...pressure releases, each pressure relief device in gas/vapor service shall...

  6. 40 CFR 60.482-4 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 60.482-4...482-4 Standards: Pressure relief devices in gas/vapor service. (a...pressure releases, each pressure relief device in gas/vapor service shall...

  7. 40 CFR 61.242-4 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 61.242-4...242-4 Standards: Pressure relief devices in gas/vapor service. (a...pressure releases, each pressure relief device in gas/vapor service shall...

  8. 40 CFR 61.242-4 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 61.242-4...242-4 Standards: Pressure relief devices in gas/vapor service. (a...pressure releases, each pressure relief device in gas/vapor service shall...

  9. 40 CFR 264.1054 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 264...1054 Standards: Pressure relief devices in gas/vapor service. (a...pressure releases, each pressure relief device in gas/vapor service shall...

  10. 40 CFR 61.242-4 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 61.242-4...242-4 Standards: Pressure relief devices in gas/vapor service. (a...pressure releases, each pressure relief device in gas/vapor service shall...

  11. 40 CFR 63.165 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 63.165...165 Standards: Pressure relief devices in gas/vapor service. (a...pressure releases, each pressure relief device in gas/vapor service shall...

  12. 46 CFR 154.419 - Design vapor pressure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Design vapor pressure. 154.419 Section 154.419 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Tanks § 154.419 Design vapor pressure. The Po of an integral tank must not exceed 24.5 kPa gauge...

  13. 46 CFR 154.419 - Design vapor pressure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Design vapor pressure. 154.419 Section 154.419 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Tanks § 154.419 Design vapor pressure. The Po of an integral tank must not exceed 24.5 kPa gauge...

  14. 46 CFR 154.419 - Design vapor pressure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Design vapor pressure. 154.419 Section 154.419 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Tanks § 154.419 Design vapor pressure. The Po of an integral tank must not exceed 24.5 kPa gauge...

  15. 46 CFR 154.445 - Design vapor pressure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Design vapor pressure. 154.445 Section 154.445 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Independent Tank Type B § 154.445 Design vapor pressure. If the surfaces of an independent tank type B...

  16. 46 CFR 154.436 - Design vapor pressure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Design vapor pressure. 154.436 Section 154.436 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS...-Membrane Tanks § 154.436 Design vapor pressure. The Po of a semi-membrane tank must not exceed 24.5...

  17. 46 CFR 154.419 - Design vapor pressure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Design vapor pressure. 154.419 Section 154.419 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Tanks § 154.419 Design vapor pressure. The Po of an integral tank must not exceed 24.5 kPa gauge...

  18. 46 CFR 154.436 - Design vapor pressure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Design vapor pressure. 154.436 Section 154.436 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS...-Membrane Tanks § 154.436 Design vapor pressure. The Po of a semi-membrane tank must not exceed 24.5...

  19. 46 CFR 154.438 - Design vapor pressure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Design vapor pressure. 154.438 Section 154.438 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Independent Tank Type A § 154.438 Design vapor pressure. (a) If the surface of an independent tank type A...

  20. 46 CFR 154.445 - Design vapor pressure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Design vapor pressure. 154.445 Section 154.445 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Independent Tank Type B § 154.445 Design vapor pressure. If the surfaces of an independent tank type B...

  1. 46 CFR 154.436 - Design vapor pressure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Design vapor pressure. 154.436 Section 154.436 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS...-Membrane Tanks § 154.436 Design vapor pressure. The Po of a semi-membrane tank must not exceed 24.5...

  2. 46 CFR 154.426 - Design vapor pressure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Design vapor pressure. 154.426 Section 154.426 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Tanks § 154.426 Design vapor pressure. The Po of a membrane tank must not exceed 24.5 kPa gauge...

  3. 46 CFR 154.438 - Design vapor pressure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Design vapor pressure. 154.438 Section 154.438 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Independent Tank Type A § 154.438 Design vapor pressure. (a) If the surface of an independent tank type A...

  4. 46 CFR 154.426 - Design vapor pressure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Design vapor pressure. 154.426 Section 154.426 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Tanks § 154.426 Design vapor pressure. The Po of a membrane tank must not exceed 24.5 kPa gauge...

  5. 46 CFR 154.436 - Design vapor pressure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Design vapor pressure. 154.436 Section 154.436 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS...-Membrane Tanks § 154.436 Design vapor pressure. The Po of a semi-membrane tank must not exceed 24.5...

  6. 46 CFR 154.436 - Design vapor pressure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Design vapor pressure. 154.436 Section 154.436 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS...-Membrane Tanks § 154.436 Design vapor pressure. The Po of a semi-membrane tank must not exceed 24.5...

  7. 46 CFR 154.438 - Design vapor pressure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Design vapor pressure. 154.438 Section 154.438 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Independent Tank Type A § 154.438 Design vapor pressure. (a) If the surface of an independent tank type A...

  8. 46 CFR 154.445 - Design vapor pressure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Design vapor pressure. 154.445 Section 154.445 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Independent Tank Type B § 154.445 Design vapor pressure. If the surfaces of an independent tank type B...

  9. 46 CFR 154.426 - Design vapor pressure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Design vapor pressure. 154.426 Section 154.426 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Tanks § 154.426 Design vapor pressure. The Po of a membrane tank must not exceed 24.5 kPa gauge...

  10. 46 CFR 154.438 - Design vapor pressure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Design vapor pressure. 154.438 Section 154.438 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Independent Tank Type A § 154.438 Design vapor pressure. (a) If the surface of an independent tank type A...

  11. 46 CFR 154.419 - Design vapor pressure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Design vapor pressure. 154.419 Section 154.419 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Tanks § 154.419 Design vapor pressure. The Po of an integral tank must not exceed 24.5 kPa gauge...

  12. 46 CFR 154.445 - Design vapor pressure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Design vapor pressure. 154.445 Section 154.445 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Independent Tank Type B § 154.445 Design vapor pressure. If the surfaces of an independent tank type B...

  13. 46 CFR 154.438 - Design vapor pressure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Design vapor pressure. 154.438 Section 154.438 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Independent Tank Type A § 154.438 Design vapor pressure. (a) If the surface of an independent tank type A...

  14. 46 CFR 154.445 - Design vapor pressure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Design vapor pressure. 154.445 Section 154.445 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Independent Tank Type B § 154.445 Design vapor pressure. If the surfaces of an independent tank type B...

  15. 46 CFR 154.426 - Design vapor pressure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Design vapor pressure. 154.426 Section 154.426 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Tanks § 154.426 Design vapor pressure. The Po of a membrane tank must not exceed 24.5 kPa gauge...

  16. 46 CFR 154.426 - Design vapor pressure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Design vapor pressure. 154.426 Section 154.426 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Tanks § 154.426 Design vapor pressure. The Po of a membrane tank must not exceed 24.5 kPa gauge...

  17. 46 CFR 154.438 - Design vapor pressure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 2012-10-01 2012-10-01 false Design vapor pressure. 154.438 Section 154.438 Shipping COAST...Equipment Independent Tank Type A § 154.438 Design vapor pressure. (a) If the surface of an independent tank...

  18. 46 CFR 154.438 - Design vapor pressure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 2014-10-01 2014-10-01 false Design vapor pressure. 154.438 Section 154.438 Shipping COAST...Equipment Independent Tank Type A § 154.438 Design vapor pressure. (a) If the surface of an independent tank...

  19. 46 CFR 154.438 - Design vapor pressure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 2010-10-01 2010-10-01 false Design vapor pressure. 154.438 Section 154.438 Shipping COAST...Equipment Independent Tank Type A § 154.438 Design vapor pressure. (a) If the surface of an independent tank...

  20. 46 CFR 154.438 - Design vapor pressure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 2011-10-01 2011-10-01 false Design vapor pressure. 154.438 Section 154.438 Shipping COAST...Equipment Independent Tank Type A § 154.438 Design vapor pressure. (a) If the surface of an independent tank...

  1. 46 CFR 154.438 - Design vapor pressure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 2013-10-01 2013-10-01 false Design vapor pressure. 154.438 Section 154.438 Shipping COAST...Equipment Independent Tank Type A § 154.438 Design vapor pressure. (a) If the surface of an independent tank...

  2. 46 CFR 154.445 - Design vapor pressure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 2010-10-01 2010-10-01 false Design vapor pressure. 154.445 Section 154.445 Shipping COAST...Equipment Independent Tank Type B § 154.445 Design vapor pressure. If the surfaces of an independent tank type...

  3. 46 CFR 154.445 - Design vapor pressure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 2011-10-01 2011-10-01 false Design vapor pressure. 154.445 Section 154.445 Shipping COAST...Equipment Independent Tank Type B § 154.445 Design vapor pressure. If the surfaces of an independent tank type...

  4. 46 CFR 154.445 - Design vapor pressure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 2013-10-01 2013-10-01 false Design vapor pressure. 154.445 Section 154.445 Shipping COAST...Equipment Independent Tank Type B § 154.445 Design vapor pressure. If the surfaces of an independent tank type...

  5. 46 CFR 154.445 - Design vapor pressure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 2012-10-01 2012-10-01 false Design vapor pressure. 154.445 Section 154.445 Shipping COAST...Equipment Independent Tank Type B § 154.445 Design vapor pressure. If the surfaces of an independent tank type...

  6. 46 CFR 154.445 - Design vapor pressure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 2014-10-01 2014-10-01 false Design vapor pressure. 154.445 Section 154.445 Shipping COAST...Equipment Independent Tank Type B § 154.445 Design vapor pressure. If the surfaces of an independent tank type...

  7. 46 CFR 30.10-59 - Reid vapor pressure-TB/ALL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Reid vapor pressure-TB/ALL. 30.10-59 Section 30.10-59...-59 Reid vapor pressure—TB/ALL. The term Reid vapor pressure means the vapor pressure of a liquid at a....01-3), Method of Test for Vapor Pressure of Petroleum Products. This Standard is available...

  8. 46 CFR 30.10-59 - Reid vapor pressure-TB/ALL.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Reid vapor pressure-TB/ALL. 30.10-59 Section 30.10-59...-59 Reid vapor pressure—TB/ALL. The term Reid vapor pressure means the vapor pressure of a liquid at a....01-3), Method of Test for Vapor Pressure of Petroleum Products. This Standard is available...

  9. 46 CFR 30.10-59 - Reid vapor pressure-TB/ALL.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Reid vapor pressure-TB/ALL. 30.10-59 Section 30.10-59...-59 Reid vapor pressure—TB/ALL. The term Reid vapor pressure means the vapor pressure of a liquid at a....01-3), Method of Test for Vapor Pressure of Petroleum Products. This Standard is available...

  10. 46 CFR 30.10-59 - Reid vapor pressure-TB/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Reid vapor pressure-TB/ALL. 30.10-59 Section 30.10-59...-59 Reid vapor pressure—TB/ALL. The term Reid vapor pressure means the vapor pressure of a liquid at a....01-3), Method of Test for Vapor Pressure of Petroleum Products. This Standard is available...

  11. 46 CFR 30.10-59 - Reid vapor pressure-TB/ALL.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Reid vapor pressure-TB/ALL. 30.10-59 Section 30.10-59...-59 Reid vapor pressure—TB/ALL. The term Reid vapor pressure means the vapor pressure of a liquid at a....01-3), Method of Test for Vapor Pressure of Petroleum Products. This Standard is available...

  12. The hysteretic evapotranspiration - vapor pressure deficit relation

    NASA Astrophysics Data System (ADS)

    Zhang, Q.; Manzoni, S.; Katul, G. G.; Porporato, A. M.; Yang, D.

    2013-12-01

    Diurnal hysteresis between evapotranspiration (ET) and vapor pressure deficit (VPD) was reported in many ecosystems but justification for its onset and magnitude remain incomplete with biotic and abiotic factors invoked as possible explanations. To place these explanations within a mathematical framework, ';rate-dependent' hysteresis originating from a phase angle difference between periodic input and output time series is first considered. Lysimeter evaporation (E) measurements from wet bare soils and model calculations using the Penman equation demonstrate that the E-VPD hysteresis emerges without any biotic effects due to a phase angle difference (or time lag) between net radiation the main driver of E, and VPD. Modulations originating from biotic effects on the ET-VPD hysteresis were then considered. The phase angle difference representation earlier employed was mathematically transformed into a storage problem and applied to the soil-plant system. The transformed system shows that soil moisture storage within the root zone can produce an ET-VPD hysteresis prototypical of those generated by phase-angle differences. To explore the interplay between all the lags in the soil-plant-atmosphere system and phase angle differences among forcing and response variables, a detailed soil-plant-atmosphere continuum (SPAC) model was developed and applied to a grassland ecosystem. The results of the SPAC model suggest that the hysteresis magnitude depends on the radiation-VPD lag. The soil moisture dry-down simulations also suggest that modeled root water potential and leaf water potential are both better indicators of the hysteresis magnitude than soil moisture, suggesting that plant water status is the main factor regulating the hysteretic relation between ET and VPD. Hence, the genesis and magnitude of the ET-VPD hysteresis are controlled directly by both biotic factors and abiotic factors such as time lag between radiation and VPD originating from boundary layer processes. Measured eddy covariance evapotranspiration (ET) and vapor pressure deficit (VPD) time series normalized by their maximum values collected in a grassland ecosystem. The magnitude of the hysteresis is quantified as the area enveloped by the ET-VPD relation (Ahys). The arrows together with time ticks indicate the progression of the diurnal cycle from sunrise to sunset.

  13. 40 CFR 65.111 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 65.111...111 Standards: Pressure relief devices in gas/vapor service. (a...this section, each pressure relief device in gas/vapor service shall...

  14. 40 CFR 63.1011 - Pressure relief devices in gas and vapor service standards.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Pressure relief devices in gas and vapor service standards...1 § 63.1011 Pressure relief devices in gas and vapor service standards...this section, each pressure relief device in gas or vapor service shall...

  15. 40 CFR 63.1011 - Pressure relief devices in gas and vapor service standards.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Pressure relief devices in gas and vapor service standards...1 § 63.1011 Pressure relief devices in gas and vapor service standards...this section, each pressure relief device in gas or vapor service shall...

  16. 40 CFR 65.111 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 65.111...111 Standards: Pressure relief devices in gas/vapor service. (a...this section, each pressure relief device in gas/vapor service shall...

  17. 40 CFR 63.1011 - Pressure relief devices in gas and vapor service standards.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Pressure relief devices in gas and vapor service standards...1 § 63.1011 Pressure relief devices in gas and vapor service standards...this section, each pressure relief device in gas or vapor service shall...

  18. 40 CFR 63.1011 - Pressure relief devices in gas and vapor service standards.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Pressure relief devices in gas and vapor service standards...1 § 63.1011 Pressure relief devices in gas and vapor service standards...this section, each pressure relief device in gas or vapor service shall...

  19. 46 CFR 39.2013 - High and low vapor pressure protection for tankships-T/ALL.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 false High and low vapor pressure protection for tankships-T... § 39.2013 High and low vapor pressure protection for tankships—T...connection, that measures the pressure in the main vapor collection line, which—...

  20. 40 CFR 63.1011 - Pressure relief devices in gas and vapor service standards.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Pressure relief devices in gas and vapor service standards...1 § 63.1011 Pressure relief devices in gas and vapor service standards...this section, each pressure relief device in gas or vapor service shall...

  1. 40 CFR 65.111 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 65.111...111 Standards: Pressure relief devices in gas/vapor service. (a...this section, each pressure relief device in gas/vapor service shall...

  2. 40 CFR 65.111 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 65.111...111 Standards: Pressure relief devices in gas/vapor service. (a...this section, each pressure relief device in gas/vapor service shall...

  3. 46 CFR 39.2013 - High and low vapor pressure protection for tankships-T/ALL.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 false High and low vapor pressure protection for tankships-T... § 39.2013 High and low vapor pressure protection for tankships—T...connection, that measures the pressure in the main vapor collection line, which—...

  4. 40 CFR 65.111 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 65.111...111 Standards: Pressure relief devices in gas/vapor service. (a...this section, each pressure relief device in gas/vapor service shall...

  5. Vapor Pressures and Vaporization Enthalpies of the n-Alkanes from C21 to C30 at T ) 298.15 K by Correlation Gas Chromatography

    E-print Network

    Chickos, James S.

    Vapor Pressures and Vaporization Enthalpies of the n-Alkanes from C21 to C30 at T ) 298.15 K pressures of these n-alkanes from T ) 298.15 to 575 K. The vapor pressure and vaporization enthalpy results-alkanes exhibit very low vapor pressures at ambient temperatures, vapor pressure measurement for most

  6. Controlling the vapor pressure of a mercury lamp

    DOEpatents

    Grossman, Mark W. (Belmont, MA); George, William A. (Rockport, MA)

    1988-01-01

    The invention described herein discloses a method and apparatus for controlling the Hg vapor pressure within a lamp. This is done by establishing and controlling two temperature zones within the lamp. One zone is colder than the other zone. The first zone is called the cold spot. By controlling the temperature of the cold spot, the Hg vapor pressure within the lamp is controlled. Likewise, by controlling the Hg vapor pressure of the lamp, the intensity and linewidth of the radiation emitted from the lamp is controlled.

  7. Controlling the vapor pressure of a mercury lamp

    DOEpatents

    Grossman, M.W.; George, W.A.

    1988-05-24

    The invention described herein discloses a method and apparatus for controlling the Hg vapor pressure within a lamp. This is done by establishing and controlling two temperature zones within the lamp. One zone is colder than the other zone. The first zone is called the cold spot. By controlling the temperature of the cold spot, the Hg vapor pressure within the lamp is controlled. Likewise, by controlling the Hg vapor pressure of the lamp, the intensity and linewidth of the radiation emitted from the lamp is controlled. 2 figs.

  8. LOX vaporization in high-pressure, hydrogen-rich gas

    NASA Technical Reports Server (NTRS)

    Litchford, Ron J.; Jeng, San-Mou

    1990-01-01

    LOX droplet vaporization in high-pressure hydrogen-rich gas is analyzed, with special attention to thermodynamic effects which compel the surface to heat to the critical state and to supercritical vaporization processes on heating to criticality. Subcritical vaporization is modeled using a quasi-steady diffusion-controlled gas-phase transport formulation coupled to an effective-conductivity internal-energy-transport model accounting for circulation effects. It is demonstrated how the droplet surface might heat to the critical state, for ambient pressures slightly greater than the critical pressure of oxygen, such that the bulk of propellant within the droplet remains substantially below the critical mixing temperature.

  9. Oxidation Of SiCOxidation Of SiC--Based MaterialsBased Materials At High WaterAt High Water--Vapor PressureVapor Pressure

    E-print Network

    Pennycook, Steve

    PressureVapor Pressure P.F. Tortorelli and K.L. MoreP.F. Tortorelli and K.L. More Oak Ridge National pressure ratios, and NOpressure ratios, and NOxx controlcontrol #12;At Higher Pressures Of Water Vapor,At Higher Pressures Of Water Vapor, Oxidative Degradation is Much WorseOxidative Degradation is Much Worse

  10. Using Dalton's Law of Partial Pressures to Determine the Vapor Pressure of a Volatile Liquid

    ERIC Educational Resources Information Center

    Hilgeman, Fred R.; Bertrand, Gary; Wilson, Brent

    2007-01-01

    This experiment, designed for a general chemistry laboratory, illustrates the use of Dalton's law of partial pressures to determine the vapor pressure of a volatile liquid. A predetermined volume of air is injected into a calibrated tube filled with a liquid whose vapor pressure is to be measured. The volume of the liquid displaced is greater than…

  11. Variation in rectal temperature, respiratory rate, and pulse rate of cattle as related to variations in solar radiation, air temperature, wind velocity, and vapor pressure 

    E-print Network

    Quazi, Mohammad Fazlur Rahim

    1955-01-01

    consists of a gas engine driving a twin-screw, helical compres sor. The screw compressor is used to pressurize saturated steam or process fluid vapors in order to achieve higher temperatures and pressures as re quired for various types of industrial... of process heat which is of greatest value to the user is high-pressure steam. Unfortunately, only low-pressure steam is directly available from the engine cooling jacket. Incor porating a mechanical vapor compressor into the co generation system...

  12. A Simple Experiment for Determining Vapor Pressure and Enthalpy of Vaporization of Water.

    ERIC Educational Resources Information Center

    Levinson, Gerald S.

    1982-01-01

    Laboratory procedures, calculations, and sample results are described for a freshman chemistry experiment in which the Clausius-Clapeyron equation is introduced as a means of describing the variation of vapor pressure with temperature and for determining enthalpy of vaporization. (Author/SK)

  13. Vapor pressures of a homologous series of polyethylene glycols as a reference data set for validating vapor pressure measurement techniques.

    NASA Astrophysics Data System (ADS)

    Krieger, Ulrich; Marcolli, Claudia; Siegrist, Franziska

    2015-04-01

    The production of secondary organic aerosol (SOA) by gas-to-particle partitioning is generally represented by an equilibrium partitioning model. A key physical parameter which governs gas-particle partitioning is the pure component vapor pressure, which is difficult to measure for low- and semivolatile compounds. For typical atmospheric compounds like e.g. citric acid or tartaric acid, vapor pressures have been reported in the literature which differ by up to six orders of magnitude [Huisman et al., 2013]. Here, we report vapor pressures of a homologous series of polyethylene glycols (triethylene glycol to octaethylene glycol) determined by measuring the evaporation rate of single, levitated aerosol particles in an electrodynamic balance. We propose to use those as a reference data set for validating different vapor pressure measurement techniques. With each addition of a (O-CH2-CH2)-group the vapor pressure is lowered by about one order of magnitude which makes it easy to detect the lower limit of vapor pressures accessible with a particular technique down to a pressure of 10-8 Pa at room temperature. Reference: Huisman, A. J., Krieger, U. K., Zuend, A., Marcolli, C., and Peter, T., Atmos. Chem. Phys., 13, 6647-6662, 2013.

  14. 33 CFR 154.2103 - Facility requirements for vessel vapor overpressure and vacuum protection.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...percent of the cargo's saturated vapor pressure in pounds per square inch absolute...divided by 12.5 psia (the vapor pressure of gasoline at 115 °F), times...115 °F, the cargo's true vapor pressure (in psia) at the...

  15. Fluid Phase Equilibria 243 (2006) 198205 Comment on "prediction of vapor pressures of solid organic

    E-print Network

    Chickos, James S.

    2006-01-01

    of vapor pressures of solid organic compounds with a group contribution method" William E. Acree Jr gave satisfactory vapor pressure predictions for many organic compounds having vapor pressures well only for substituting into their predictive vapor pressure expression. The intent of this short

  16. 46 CFR 30.10-59 - Reid vapor pressure-TB/ALL.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Reid vapor pressure-TB/ALL. 30.10-59 Section 30...PROVISIONS Definitions § 30.10-59 Reid vapor pressure—TB/ALL. The term Reid vapor pressure means the vapor pressure of a...

  17. 46 CFR 30.10-59 - Reid vapor pressure-TB/ALL.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Reid vapor pressure-TB/ALL. 30.10-59 Section 30...PROVISIONS Definitions § 30.10-59 Reid vapor pressure—TB/ALL. The term Reid vapor pressure means the vapor pressure of a...

  18. 46 CFR 30.10-59 - Reid vapor pressure-TB/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Reid vapor pressure-TB/ALL. 30.10-59 Section 30...PROVISIONS Definitions § 30.10-59 Reid vapor pressure—TB/ALL. The term Reid vapor pressure means the vapor pressure of a...

  19. 46 CFR 30.10-59 - Reid vapor pressure-TB/ALL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Reid vapor pressure-TB/ALL. 30.10-59 Section 30...PROVISIONS Definitions § 30.10-59 Reid vapor pressure—TB/ALL. The term Reid vapor pressure means the vapor pressure of a...

  20. 46 CFR 30.10-59 - Reid vapor pressure-TB/ALL.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Reid vapor pressure-TB/ALL. 30.10-59 Section 30...PROVISIONS Definitions § 30.10-59 Reid vapor pressure—TB/ALL. The term Reid vapor pressure means the vapor pressure of a...

  1. Hypothetical Thermodynamic Properties: Vapor Pressures and Vaporization Enthalpies of the Even n-Alkanes from C40 to C76 at T ) 298.15 K by

    E-print Network

    Chickos, James S.

    Hypothetical Thermodynamic Properties: Vapor Pressures and Vaporization Enthalpies of the Even n in combination with earlier work to evaluate the vaporization enthalpies and vapor pressures of these n-alkanes from T ) (298.15 to 540) K. The vapor pressure and vaporization enthalpy results obtained are compared

  2. Vapor Pressures and Vaporization Enthalpies of the n-Alkanes from C31 to C38 at T ) 298.15 K by Correlation Gas Chromatography

    E-print Network

    Chickos, James S.

    Vapor Pressures and Vaporization Enthalpies of the n-Alkanes from C31 to C38 at T ) 298.15 K with other literature values to evaluate the vaporization enthalpies and vapor pressures of these n-alkanes from T ) 298.15 to 575 K. The vapor pressure and vaporization enthalpy results obtained are compared

  3. Water-vapor pressure control in a volume

    NASA Technical Reports Server (NTRS)

    Scialdone, J. J.

    1978-01-01

    The variation with time of the partial pressure of water in a volume that has openings to the outside environment and includes vapor sources was evaluated as a function of the purging flow and its vapor content. Experimental tests to estimate the diffusion of ambient humidity through openings and to validate calculated results were included. The purging flows required to produce and maintain a certain humidity in shipping containers, storage rooms, and clean rooms can be estimated with the relationship developed here. These purging flows are necessary to prevent the contamination, degradation, and other effects of water vapor on the systems inside these volumes.

  4. Structural rearrangements in a lamellar diblock copolymer thin film during treatment with saturated solvent vapor

    PubMed Central

    Di, Zhenyu; Posselt, Dorthe; Smilgies, Detlef-M.; Papadakis, Christine M.

    2010-01-01

    We have investigated the structural changes in thin films of lamellar poly(styrene-b-butadiene) diblock copolymers during treatment with saturated cyclohexane vapor, a solvent slightly selective for polybutadiene. Using real-time, in-situ grazing-incidence small-angle X-ray scattering (GISAXS), the swelling and the rearrangement of the lamellae were investigated with a time resolution of a few seconds, and the underlying processes on the molecular level were identified. After a few minutes in vapor, a transient state with a more well-defined and more long-range ordered lamellar orientation was encountered. Additional parallel lamellae formed which we attribute to the increased degree of coiling of the polymers in the swollen state. Eventually, the film became disordered. These changes are attributed to the increased mobility of the swollen polymers and the gradually decreasing segment-segment interaction parameter in the film as solvent is absorbed. PMID:20305742

  5. Evaporation rate and vapor pressure of selected polymeric lubricating oils.

    NASA Technical Reports Server (NTRS)

    Gardos, M. N.

    1973-01-01

    A recently developed ultrahigh-vacuum quartz spring mass sorption microbalance has been utilized to measure the evaporation rates of several low-volatility polymeric lubricating oils at various temperatures. The evaporation rates are used to calculate the vapor pressures by the Langmuir equation. A method is presented to accurately estimate extended temperature range evaporation rate and vapor pressure data for polymeric oils, incorporating appropriate corrections for the increases in molecular weight and the change in volatility of the progressively evaporating polymer fractions. The logarithms of the calculated data appear to follow linear relationships within the test temperature ranges, when plotted versus 1000/T. These functions and the observed effusion characteristics of the fluids on progressive volatilization are useful in estimating evaporation rate and vapor pressure changes on evaporative depletion.

  6. Study of the effects of noisy data on the determination of the enthalpy of vaporization from a vapor pressure equation 

    E-print Network

    Casserly, Thomas Bryan

    2013-02-22

    Chemical engineers use software tools everyday to aid them in solving complex problems. Software packages simulate virtually every aspect of a chemical process, including the use of source vapor pressure data to fit empirical constants of a vapor...

  7. Pressure (Or No Royal Road)

    ERIC Educational Resources Information Center

    Bradley, J.

    1973-01-01

    Discusses how difficult the various problems of pressure, partial pressure, gas laws, and vapor pressure are for students. Outlines the evolution of the concept of pressure, the gas equation for a perfect gas, partial pressures, saturated vapor pressure, Avogadro's hypothesis, Raoult's law, and the vapor pressure of ideal solutions. (JR)

  8. Vapor pressures and gas-film coefficients for ketones

    USGS Publications Warehouse

    Rathbun, R.E.; Tai, D.Y.

    1987-01-01

    Comparison of handbook vapor pressures for seven ketones with more recent literature data showed large differences for four of the ketones. Gas-film coefficients for the volatilization of these ketones from water determined by two different methods were in reasonable agreement. ?? 1987.

  9. New class of compounds have very low vapor pressures

    NASA Technical Reports Server (NTRS)

    Angell, C. A.; Gruen, D. M.

    1967-01-01

    Magnesium hexahydrate tetrachlorometallates are 50-volume-percent water, have a high melting point and possess a low vapor pressure. These new compounds are relatively noncorrosive, thermally stable, and water soluble but not hygroscopic. They may have potential applications as cooling fluids.

  10. Distillation device supplies cesium vapor at constant pressure

    NASA Technical Reports Server (NTRS)

    Basiulis, A.; Shefsiek, P. K.

    1968-01-01

    Distillation apparatus in the form of a U tube supplies small amounts of pure cesium vapor at constant pressure to a thermionic converter. The upstream leg of the U tube is connected to a vacuum pump to withdraw noncondensable impurities, the bottom portion serves as a reservoir for the liquid cesium.

  11. 46 CFR 154.426 - Design vapor pressure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Membrane Tanks § 154.426 Design vapor pressure. The Po of a membrane tank must not exceed 24.5 kPa gauge (3.55 psig) unless special approval...

  12. 46 CFR 154.426 - Design vapor pressure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Membrane Tanks § 154.426 Design vapor pressure. The Po of a membrane tank must not exceed 24.5 kPa gauge (3.55 psig) unless special approval...

  13. 46 CFR 154.436 - Design vapor pressure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Semi-Membrane Tanks § 154.436 Design vapor pressure. The Po of a semi-membrane tank must not exceed 24.5 kPa gauge (3.55 psig) unless special...

  14. 46 CFR 154.436 - Design vapor pressure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Semi-Membrane Tanks § 154.436 Design vapor pressure. The Po of a semi-membrane tank must not exceed 24.5 kPa gauge (3.55 psig) unless special...

  15. 46 CFR 154.426 - Design vapor pressure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Membrane Tanks § 154.426 Design vapor pressure. The Po of a membrane tank must not exceed 24.5 kPa gauge (3.55 psig) unless special approval...

  16. 46 CFR 154.436 - Design vapor pressure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Semi-Membrane Tanks § 154.436 Design vapor pressure. The Po of a semi-membrane tank must not exceed 24.5 kPa gauge (3.55 psig) unless special...

  17. 46 CFR 154.436 - Design vapor pressure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Semi-Membrane Tanks § 154.436 Design vapor pressure. The Po of a semi-membrane tank must not exceed 24.5 kPa gauge (3.55 psig) unless special...

  18. 46 CFR 154.436 - Design vapor pressure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Semi-Membrane Tanks § 154.436 Design vapor pressure. The Po of a semi-membrane tank must not exceed 24.5 kPa gauge (3.55 psig) unless special...

  19. 46 CFR 154.426 - Design vapor pressure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Membrane Tanks § 154.426 Design vapor pressure. The Po of a membrane tank must not exceed 24.5 kPa gauge (3.55 psig) unless special approval...

  20. Hypothetical Thermodynamic Properties: Vapor Pressures and Vaporization Enthalpies of the Even n-Alkanes from C78 to C92 at T ) 298.15 K by

    E-print Network

    Chickos, James S.

    Hypothetical Thermodynamic Properties: Vapor Pressures and Vaporization Enthalpies of the Even n and vapor pressures of the n-alkanes from T ) (298.15 to 540) K for heneicosane to dononacontane. The vapor pressure and vaporization enthalpy results obtained are compared with estimated data from Morgan's "PERT2

  1. 40 CFR 60.482-4a - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 60.482-4a...482-4a Standards: Pressure relief devices in gas/vapor service. (a...pressure releases, each pressure relief device in gas/vapor service shall...

  2. 40 CFR 60.482-4a - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 60.482-4a...482-4a Standards: Pressure relief devices in gas/vapor service. (a...pressure releases, each pressure relief device in gas/vapor service shall...

  3. 40 CFR 60.482-4a - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 60.482-4a...482-4a Standards: Pressure relief devices in gas/vapor service. (a...pressure releases, each pressure relief device in gas/vapor service shall...

  4. 40 CFR 60.482-4a - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 60.482-4a...482-4a Standards: Pressure relief devices in gas/vapor service. (a...pressure releases, each pressure relief device in gas/vapor service shall...

  5. 40 CFR 60.482-4a - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...false Standards: Pressure relief devices in gas/vapor service. 60.482-4a...482-4a Standards: Pressure relief devices in gas/vapor service. (a...pressure releases, each pressure relief device in gas/vapor service shall...

  6. Model for Residual Saturations and Capillary Imbibition and Drainage Pressures in Granular Materials

    SciTech Connect

    LAURINAT, JAMESE

    2004-11-01

    A pore saturation model expresses the capillary pressure as a function of a characteristic pore pressure and the wetting phase saturation. Singularity analyses of the total energies of the wetting and nonwetting phases give the residual saturations for the two phases. The total energy consists of a potential term and a work term associated with the effective pressure gradient for each phase. The derived residual wetting saturation is 0.236, and the derived residual nonwetting saturation is 0.884. The model includes separate pressures for imbibition and drainage to account for capillary hysteresis. In the model, the pressure gradient for the wetting phase defines the imbibition pressure, and the nonwetting phase pressure gradient defines the drainage pressure. At the residual nonwetting saturation, the two pressures differ by the characteristic pore pressure. The two pressures coincide at a critical minimum saturation of 0.301. The model also includes an entry head to account for the minimum force required for drainage to begin. The model uses a single fitting parameter, a characteristic pore pressure, which can be related to a characteristic pore diameter.

  7. Controlling Vapor Pressure In Hanging-Drop Crystallization

    NASA Technical Reports Server (NTRS)

    Carter, Daniel C.; Smith, Robbie

    1988-01-01

    Rate of evaporation adjusted to produce larger crystals. Device helps to control vapor pressure of water and other solvents in vicinity of hanging drop of solution containing dissolved enzyme protein. Well of porous frit (sintered glass) holds solution in proximity to drop of solution containing protein or enzyme. Vapor from solution in frit controls evaporation of solvent from drop to control precipitation of protein or enzyme. With device, rate of nucleation limited to decrease number and increase size (and perhaps quality) of crystals - large crystals of higher quality needed for x-ray diffraction studies of macromolecules.

  8. Low temperature measurement of the vapor pressures of planetary molecules

    NASA Technical Reports Server (NTRS)

    Kraus, George F.

    1989-01-01

    Interpretation of planetary observations and proper modeling of planetary atmospheres are critically upon accurate laboratory data for the chemical and physical properties of the constitutes of the atmospheres. It is important that these data are taken over the appropriate range of parameters such as temperature, pressure, and composition. Availability of accurate, laboratory data for vapor pressures and equilibrium constants of condensed species at low temperatures is essential for photochemical and cloud models of the atmospheres of the outer planets. In the absence of such data, modelers have no choice but to assume values based on an educated guess. In those cases where higher temperature data are available, a standard procedure is to extrapolate these points to the lower temperatures using the Clausius-Clapeyron equation. Last summer the vapor pressures of acetylene (C2H2) hydrogen cyanide (HCN), and cyanoacetylene (HC3N) was measured using two different methods. At the higher temperatures 1 torr and 10 torr capacitance manometers were used. To measure very low pressures, a technique was used which is based on the infrared absorption of thin film (TFIR). This summer the vapor pressure of acetylene was measured the TFIR method. The vapor pressure of hydrogen sulfide (H2S) was measured using capacitance manometers. Results for H2O agree with literature data over the common range of temperature. At the lower temperatures the data lie slightly below the values predicted by extrapolation of the Clausius-Clapeyron equation. Thin film infrared (TFIR) data for acetylene lie significantly below the values predicted by extrapolation. It is hoped to bridge the gap between the low end of the CM data and the upper end of the TFIR data in the future using a new spinning rotor gauge.

  9. Ice Nucleation of Snomax® Particles below Water Vapor Saturation: Immersion Freezing in Concentrated Solution Droplets

    NASA Astrophysics Data System (ADS)

    Kanji, Z. A.; Boose, Y.; Augustin, S.; Wex, H.

    2014-12-01

    Heterogeneous ice nucleation in the atmosphere is important and has received an increasing amount of interest in the past years, as it initiates the ice phase in mixed phase clouds and, to some extent, also in cirrus clouds. The presence of ice influences cloud radiative properties and, for mixed phase clouds, also the formation of precipitation and cloud lifetime. Immersion freezing has been in the focus of ice nucleation research in recent years. Here, we examine ice nucleation activity of biological ice nuclei (IN) derived from bacteria, namely of particles generated from a suspensions of Snomax®, both above and below water vapor saturation. Measurements were done with PINC (Portable Ice Nucleus Counter, Chou et al., 2011) during a measurement campaign at LACIS (Leipzig Aerosol Cloud Interaction Simulator, see e.g. Wex et al., 2014) in Leipzig. Immersion freezing measurements from PINC and LACIS were in agreement in the temperature regime for which both instruments operate reliably. Here, we will show that measurements done below water vapor saturation follow what would be expected for immersion freezing in concentrated solutions, similar to what was suggested for coated kaolinite particles in Wex et al. (2014). Chou, C., O. Stetzer, E. Weingartner, Z. Juranyi, Z. A. Kanji, and U. Lohmann (2011), Ice nuclei properties within a Saharan dust event at the Jungfraujoch in the Swiss Alps, Atmos. Chem. Phys., 11(10), 4725-4738, doi:10.5194/acp-11-4725-2011. Wex, H., P. J. DeMott, Y. Tobo, S. Hartmann, M. Rösch, T. Clauss, L. Tomsche, D. Niedermeier, and F. Stratmann (2014), Kaolinite particles as ice nuclei: learning from the use of different kaolinite samples and different coatings, Atmos. Chem. Phys., 14, doi:10.5194/acp-14-5529-2014.

  10. 46 CFR 154.405 - Design vapor pressure (Po) of a cargo tank.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Design vapor pressure (Po) of a cargo tank...VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Cargo Containment Systems § 154.405 Design vapor pressure (Po ) of a...

  11. Method and apparatus to measure vapor pressure in a flow system

    DOEpatents

    Grossman, Mark W. (Belmont, MA); Biblarz, Oscar (Swampscott, MA)

    1991-01-01

    The present invention is directed to a method for determining, by a condensation method, the vapor pressure of a material with a known vapor pressure versus temperature characteristic, in a flow system particularly in a mercury isotope enrichment process.

  12. Solar radiation and water vapor pressure to forecast chickenpox epidemics.

    PubMed

    Hervás, D; Hervás-Masip, J; Nicolau, A; Reina, J; Hervás, J A

    2015-03-01

    The clear seasonality of varicella infections in temperate regions suggests the influence of meteorologic conditions. However, there are very few data on this association. The aim of this study was to determine the seasonal pattern of varicella infections on the Mediterranean island of Mallorca (Spain), and its association with meteorologic conditions and schooling. Data on the number of cases of varicella were obtained from the Network of Epidemiologic Surveillance, which is composed of primary care physicians who notify varicella cases on a compulsory basis. From 1995 to 2012, varicella cases were correlated to temperature, humidity, rainfall, water vapor pressure, atmospheric pressure, wind speed, and solar radiation using regression and time-series models. The influence of schooling was also analyzed. A total of 68,379 cases of varicella were notified during the study period. Cases occurred all year round, with a peak incidence in June. Varicella cases increased with the decrease in water vapor pressure and/or the increase of solar radiation, 3 and 4 weeks prior to reporting, respectively. An inverse association was also observed between varicella cases and school holidays. Using these variables, the best fitting autoregressive moving average with exogenous variables (ARMAX) model could predict 95 % of varicella cases. In conclusion, varicella in our region had a clear seasonality, which was mainly determined by solar radiation and water vapor pressure. PMID:25265908

  13. A survey and new measurements of ice vapor pressure at temperatures between 170 and 250K

    NASA Technical Reports Server (NTRS)

    Marti, James; Mauersberger, Konrad

    1993-01-01

    New measurements of ice vapor pressures at temperatures between 170 and 250 K are presented and published vapor pressure data are summarized. An empirical vapor pressure equation was derived and allows prediction of vapor pressures between 170 k and the triple point of water with an accuracy of approximately 2 percent. Predictions obtained agree, within experimental uncertainty, with the most reliable equation derived from thermodynamic principles.

  14. 40 CFR 63.7944 - How do I determine the maximum HAP vapor pressure of my remediation material?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...do I determine the maximum HAP vapor pressure of my remediation material...do I determine the maximum HAP vapor pressure of my remediation material...must determine the maximum HAP vapor pressure of your remediation...

  15. 40 CFR 63.7944 - How do I determine the maximum HAP vapor pressure of my remediation material?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...do I determine the maximum HAP vapor pressure of my remediation material...do I determine the maximum HAP vapor pressure of my remediation material...must determine the maximum HAP vapor pressure of your remediation...

  16. 40 CFR 63.7944 - How do I determine the maximum HAP vapor pressure of my remediation material?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...do I determine the maximum HAP vapor pressure of my remediation material...do I determine the maximum HAP vapor pressure of my remediation material...must determine the maximum HAP vapor pressure of your remediation...

  17. 40 CFR 63.7944 - How do I determine the maximum HAP vapor pressure of my remediation material?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...do I determine the maximum HAP vapor pressure of my remediation material...do I determine the maximum HAP vapor pressure of my remediation material...must determine the maximum HAP vapor pressure of your remediation...

  18. 40 CFR 63.7944 - How do I determine the maximum HAP vapor pressure of my remediation material?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...do I determine the maximum HAP vapor pressure of my remediation material...do I determine the maximum HAP vapor pressure of my remediation material...must determine the maximum HAP vapor pressure of your remediation...

  19. Vapor pressure and vapor fractionation of silicate melts of tektite composition

    USGS Publications Warehouse

    Walter, Louis S.; Carron, M.K.

    1964-01-01

    The total vapor pressure of Philippine tektite melts of approximately 70 per cent silica has been determined at temperatures ranging from 1500 to 2100??C. This pressure is 190 ?? 40 mm Hg at 1500??C, 450 ?? 50 mm at 1800??C and 850 ?? 70 mm at 2100?? C. Determinations were made by visually observing the temperature at which bubbles began to form at a constant low ambient pressure. By varying the ambient pressure, a boiling point curve was constructed. This curve differs from the equilibrium vapor pressure curve due to surface tension effects. This difference was evaluated by determining the equilibrium bubble size in the melt and calculating the pressure due to surface tension, assuming the latter to be 380 dyn/cm. The relative volatility from tektite melts of the oxides of Na, K, Fe, Al and Si has been determined as a function of temperature, total pressure arid roughly, of oxygen fugacity. The volatility of SiO2 is decreased and that of Na2O and K2O is increased in an oxygen-poor environment. Preliminary results indicate that volatilization at 2100??C under atmospheric pressure caused little or no change in the percentage Na2O and K2O. The ratio Fe3 Fe2 of the tektite is increased in ambient air at a pressure of 9 ?? 10-4 mm Hg (= 106.5 atm O2, partial pressure) at 2000??C. This suggests that tektites were formed either at lower oxygen pressures or that they are a product of incomplete oxidation of parent material with a still lower ferricferrous ratio. ?? 1964.

  20. 46 CFR 154.405 - Design vapor pressure (Po) of a cargo tank.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Design vapor pressure (Po) of a cargo tank. 154.405... Equipment Cargo Containment Systems § 154.405 Design vapor pressure (Po) of a cargo tank. (a) The design vapor pressure (Po) of a cargo tank must be equal to or greater than the MARVS. (b) The Po of a...

  1. Effect of Substrate Roughness on D Spacing Supports Theoretical Resolution of Vapor Pressure Paradox

    E-print Network

    Nagle, John F.

    Effect of Substrate Roughness on D Spacing Supports Theoretical Resolution of Vapor Pressure with and provides experimental support for a recently proposed theoretical resolution of the vapor pressure paradox has been called the vapor pressure paradox (Rand and Parsegian, 1989). Resolving this paradox

  2. Measurements of the Vapor Pressure of Supercooled Water Using Infrared Spectroscopy

    E-print Network

    Kostinski, Alex

    Measurements of the Vapor Pressure of Supercooled Water Using Infrared Spectroscopy WILL CANTRELL 14 May 2007, in final form 6 December 2007) ABSTRACT Measurements are presented of the vapor pressure' data correspond to the vapor pressure of liquid water, not a mixture of liquid water and ice. Values

  3. Surface structure, composition, and polarity of indium nitride grown by high-pressure chemical vapor deposition

    E-print Network

    Dietz, Nikolaus

    grown by high-pressure chemical vapor deposition have been studied. Atomic hydrogen cleaning produced and heterostructures--which can be accomplished by low- pressure metalorganic chemical vapor deposition MOCVD --the- rium vapor pressure of nitrogen during growth. This requires different approaches in growing structures

  4. Optical characterization of InN layers grown by high-pressure chemical vapor deposition

    E-print Network

    Dietz, Nikolaus

    Optical characterization of InN layers grown by high-pressure chemical vapor deposition M. Alevli properties of InN layers grown by high-pressure chemical vapor deposition have been studied. Raman, infrared at elevated temperatures, a high-pressure chemical vapor deposition HPCVD system has been established at GSU.6

  5. 46 CFR 154.405 - Design vapor pressure (Po) of a cargo tank.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Design vapor pressure (Po) of a cargo tank. 154.405... Equipment Cargo Containment Systems § 154.405 Design vapor pressure (Po) of a cargo tank. (a) The design vapor pressure (Po) of a cargo tank must be equal to or greater than the MARVS. (b) The Po of a...

  6. 46 CFR 154.405 - Design vapor pressure (Po) of a cargo tank.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Design vapor pressure (Po) of a cargo tank. 154.405... Equipment Cargo Containment Systems § 154.405 Design vapor pressure (Po) of a cargo tank. (a) The design vapor pressure (Po) of a cargo tank must be equal to or greater than the MARVS. (b) The Po of a...

  7. 46 CFR 39.2013 - High and low vapor pressure protection for tankships-T/ALL.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false High and low vapor pressure protection for tankships-T... CONTROL SYSTEMS Equipment and Installation § 39.2013 High and low vapor pressure protection for tankships—T/ALL. Each tankship with a vapor collection system must be fitted with a pressure-sensing...

  8. RELATIONSHIP BETWEEN TRANSPIRATION AND NITROGEN UPTAKE BY PEPPER (CAPSICUM ANNUUM) AS MEDIATED BY VAPOR PRESSURE DEFICIT

    E-print Network

    Teskey, Robert O.

    BY VAPOR PRESSURE DEFICIT by KATHERINE E. BOWER (Under the Direction of Robert O. Teskey) ABSTRACT) were grown in growth chambers with differing vapor pressure deficits (VPD, 1.20 kPa and 1.98 k and growth even under low nutrient conditions. INDEX WORDS: nitrogen, pepper, transpiration, vapor pressure

  9. A HOMOGENIZATION TECHNIQUE FOR THE BOLTZMANN EQUATION FOR LOW PRESSURE CHEMICAL VAPOR DEPOSITION 1

    E-print Network

    Markowich, Peter A.

    A HOMOGENIZATION TECHNIQUE FOR THE BOLTZMANN EQUATION FOR LOW PRESSURE CHEMICAL VAPOR DEPOSITION 1 the approach. The setup models low pressure chemical vapor deposition processes in the manufacturing. Low pressure chemical vapor deposition is used in the manufactur- ing of integrated circuits

  10. 46 CFR 39.2013 - High and low vapor pressure protection for tankships-T/ALL.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false High and low vapor pressure protection for tankships-T... CONTROL SYSTEMS Equipment and Installation § 39.2013 High and low vapor pressure protection for tankships—T/ALL. Each tankship with a vapor collection system must be fitted with a pressure-sensing...

  11. 46 CFR 154.405 - Design vapor pressure (Po) of a cargo tank.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Design vapor pressure (Po) of a cargo tank. 154.405... Equipment Cargo Containment Systems § 154.405 Design vapor pressure (Po) of a cargo tank. (a) The design vapor pressure (Po) of a cargo tank must be equal to or greater than the MARVS. (b) The Po of a...

  12. Observations of Accelerated Silicon Carbide Recession by Oxidation at High Water-Vapor Pressures

    E-print Network

    Pennycook, Steve

    Observations of Accelerated Silicon Carbide Recession by Oxidation at High Water-Vapor PressuresC at 1200°C and high water-vapor pressures (1.5 atm) has shown SiC recession rates that exceed what is predicted based on parabolic oxidation at water-vapor pressures of less than or equal to 1 atm. After

  13. 46 CFR 154.405 - Design vapor pressure (Po) of a cargo tank.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Design vapor pressure (Po) of a cargo tank. 154.405... Equipment Cargo Containment Systems § 154.405 Design vapor pressure (Po) of a cargo tank. (a) The design vapor pressure (Po) of a cargo tank must be equal to or greater than the MARVS. (b) The Po of a...

  14. Correlation Between Opacity and Surface Water Vapor Pressure Measurements at Rio Frio

    E-print Network

    Groppi, Christopher

    Correlation Between Opacity and Surface Water Vapor Pressure Measurements at Rio Frio M.A. Holdaway 1, 1996 Abstract We use the surface water vapor pressure measured by weather stations at 4060 m opacity. The surface water vapor pressure is inverted some 20% of the time at night and some 35

  15. Absence of a vestigial vapor pressure paradox John F. Nagle1

    E-print Network

    Nagle, John F.

    Absence of a vestigial vapor pressure paradox John F. Nagle1 and John Katsaras2 1 Department 26 January 1999 The enigmatic but much accepted vapor pressure paradox for oriented lipid bilayer that there is no vapor pressure paradox. The first result of this paper is to consider another degree of freedom

  16. 40 CFR 63.1030 - Pressure relief devices in gas and vapor service standards.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Pressure relief devices in gas and vapor service standards...Standards § 63.1030 Pressure relief devices in gas and vapor service standards...this section, each pressure relief device in gas and vapor service shall...

  17. 40 CFR 63.1030 - Pressure relief devices in gas and vapor service standards.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Pressure relief devices in gas and vapor service standards...Standards § 63.1030 Pressure relief devices in gas and vapor service standards...this section, each pressure relief device in gas and vapor service shall...

  18. 40 CFR 63.1030 - Pressure relief devices in gas and vapor service standards.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Pressure relief devices in gas and vapor service standards...Standards § 63.1030 Pressure relief devices in gas and vapor service standards...this section, each pressure relief device in gas and vapor service shall...

  19. 40 CFR 63.1030 - Pressure relief devices in gas and vapor service standards.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Pressure relief devices in gas and vapor service standards...Standards § 63.1030 Pressure relief devices in gas and vapor service standards...this section, each pressure relief device in gas and vapor service shall...

  20. 40 CFR 63.1030 - Pressure relief devices in gas and vapor service standards.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Pressure relief devices in gas and vapor service standards...Standards § 63.1030 Pressure relief devices in gas and vapor service standards...this section, each pressure relief device in gas and vapor service shall...

  1. Vapor pressure measurements of La?Gd alloys

    NASA Astrophysics Data System (ADS)

    Shoji, Yoshiyuki; Matsui, Tsuneo; Nakamura, Kinya; Inoue, Tadashi

    1997-08-01

    The vapor pressures of La(g) and Gd(g) over La xGd 1- x alloys ( x = 0.00, 0.12, 0.22, 0.45, 0.70, 0.74, 0.85, 1.00) were measured with a time-of-flight mass spectrometer equipped with a tungsten Knudsen cell over the temperature range 1588 to 1797 K. The chemical activities of lanthanum and gadolinium in the alloys were determined by comparing the vapor pressures of La(g) and Gd(g) over the alloys with those over the pure metals. The chemical activities, thus obtained, showed positive deviations from Raoult's law over the entire compositional range. The interatomic force between gadolinium and lanthanum was thought to be repulsive. The partial molar Gibbs free energy and the Gibbs free energy, enthalpy and entropy of formation were calculated from the activity values.

  2. Low vapor pressure braze alloys for thermionic energy converters

    NASA Technical Reports Server (NTRS)

    Bair, V. L.

    1976-01-01

    The evaluation of cesium diode electrode materials called for braze fillers with very low vapor pressures and a wide range of melting points. Binary alloys of low vapor pressure refractory metals were chosen to fill this need. These alloys of Th, Zr, Hf, Ru, Nb, Ir, Mo, Ta, Os, Re, and W have reported melting point minima or eutectics from 1,510 K to above 3,000 K. Preliminary data are compiled on the use of several of these braze alloys. Melting points and surface wetting on a Ta base are given. Results of brazing Ir, LaB6, Nb, Re, W, and Zr-22 wt % ZrO2 materials into Ta and Nb-1% Zr bases are presented. Current braze usage is summarized.

  3. Low vapor pressure braze alloys for thermionic energy converters

    NASA Technical Reports Server (NTRS)

    Bair, V. L.

    1976-01-01

    Preliminary results in the use of some low-vapor-pressure braze alloys are reported; these are binary alloys of refractory metals (Th, Zr, Hf, Ru, Nb, Ir, Mo, Ta, Os, Re, W) with vapor pressures below 0.1 nanotorr at 1500 K or 10 microtorr at 2000 K. The melting point minima or eutectics of the alloys range from 1510 K to above 3000 K. Melting points and surface wetting on a Ta base are given. Results are presented on brazing of Ir, LaB6, Nb, Re, W, and ZrO2 (with 22 wt % Zr) into a Ta base or a Nb-1% Zr base. The results are applicable in electrode screening programs for thermionic cesium diodes.

  4. Chemical Vapor Deposition at High Pressure in a Microgravity Environment

    NASA Technical Reports Server (NTRS)

    McCall, Sonya; Bachmann, Klaus; LeSure, Stacie; Sukidi, Nkadi; Wang, Fuchao

    1999-01-01

    In this paper we present an evaluation of critical requirements of organometallic chemical vapor deposition (OMCVD) at elevated pressure for a channel flow reactor in a microgravity environment. The objective of using high pressure is to maintain single-phase surface composition for materials that have high thermal decomposition pressure at their optimum growth temperature. Access to microgravity is needed to maintain conditions of laminar flow, which is essential for process analysis. Based on ground based observations we present an optimized reactor design for OMCVD at high pressure and reduced gravity. Also, we discuss non-intrusive real-time optical monitoring of flow dynamics coupled to homogeneous gas phase reactions, transport and surface processes. While suborbital flights may suffice for studies of initial stages of heteroepitaxy experiments in space are essential for a complete evaluation of steady-state growth.

  5. Vapor-Saturated Melting of Fertile Peridotite Revisited: A new Experimental Approach and Re-evaluation of the Hydrous Peridotite Solidus

    NASA Astrophysics Data System (ADS)

    Grove, T. L.

    2001-12-01

    The vapor-saturated melting relations of peridotite have been determined for a fertile mantle composition of Hart and Zindler (1986, Chem Geol 57: 247) over the pressure range of 1.2 to 2.4 GPa. For example, at 1.2 GPa melt is present at a temperature of 980° C and at 2.4 GPa melt is present at 920° C. These temperatures should be viewed as maximum values for the vapor-saturated solidus (although see below) because the initial melting temperature of multi-phase, multicomponent systems can often be difficult to detect. At 2.4 GPa the melt composition is highly silica-undersaturated and very aluminous ( ~ 21 wt. % Al2O3). Wet mantle melts are thought to be high in silica, but this is not the case for these hydrous melts. At 1.2 GPa, melt fractions are too small to allow reliable analysis. The experiments have been carried out in a piston cylinder apparatus using Au capsules. The starting material is an oxide mixture containing 14.5 wt. % H2O added as brucite. Free water present in the experiment after quenching indicates subsolidus conditions. The absence of fluid in experiments above the vapor-saturated solidus shows that all of the free H2O is dissolved in the melt. The high H2O content of the starting material moves the bulk composition close to the vapor-saturated melt composition, therefore increasing the amount of melt produced close to the solidus and making detection of low melt fraction possible. Studies of the hydrous peridotite solidus carried out between 1970 and 1975 by Mysen and Boettcher, Kushiro and others, Green and Millhollen and others at 2.0 GPa ranged from < 800 to ~ 1000° C, a variation of over 200 degrees. In a subduction zone environment a fluid-rich component released from the slab ascends into hotter overlying mantle and melting initiates at the vapor-saturated solidus. Melting would begin at a depth of ~ 75 km in the mantle wedge, for a realistic thermal structure. Melting would continue as these initial H2O-rich buoyant melts ascend into hotter, shallower mantle and re-equilibrate with their surroundings. The initiation of melting deep in the mantle wedge has implications for both chemical and mechanical processes in the subduction zone environment.

  6. UNCORRECTEDPROOF Please cite this article in press as: D. Lipkind et al., The vaporization enthalpies and vapor pressures of a series of unsaturated fatty acids methyl

    E-print Network

    Chickos, James S.

    enthalpies and vapor pressures of a series of unsaturated fatty acids methyl esters by correlation gas­8 Thermochimica Acta xxx (2007) xxx­xxx The vaporization enthalpies and vapor pressures of a series of unsaturated- vonate (methyl Z 15-tetracosenoate) are evaluated at T = 298.15 and vapor pressures are evaluated over

  7. Ice nucleation of Snomax® particles below water vapor saturation: immersion freezing in concentrated solution droplets

    NASA Astrophysics Data System (ADS)

    Wex, Heike; Kanji, Zamin A.; Boose, Yvonne; Beyer, Alexander; Henning, Silvia; Augustin-Bauditz, Stefanie

    2015-04-01

    Heterogeneous ice nucleation has received an increasing amount of interest in the past years, as it initiates the ice phase in mixed phase clouds (MPCs) and, to some extent, also in cirrus clouds. The presence of ice influences cloud radiative properties and, for mixed phase clouds, also the formation of precipitation. Immersion freezing is thought to be the most important mechanism through which ice formation could take place in MPCs. Here, we examine the ice nucleation activity of biological ice nucleating particles (INP) derived from bacteria, namely, particles generated from Snomax® suspensions, both above and below water vapor saturation. During a measurement campaign in Leipzig, ice nucleation measurements were conducted with PINC (Portable Ice Nucleus Counter, Chou et al., 2011) and LACIS (Leipzig Aerosol Cloud Interaction Simulator, see e.g. Wex et al., 2014a). Immersion freezing measurements from PINC and LACIS were in agreement in the temperature regime for which both instruments operate reliably. Here, we will show that measurements done below water vapour saturation and above the deliquescence relative humidity of the Snomax® particles follow what would be expected for immersion freezing in concentrated solutions, similar to what was suggested for coated kaolinite particles in Wex et al. (2014b). Additionally, some measurements reported in the literature that were done in the water vapour sub-saturated regime will be evaluated based on the assumption made above, showing that at least some of the ice nucleation which previously was ascribed to deposition ice nucleation rather follows the behavior of immersion freezing in concentrated solutions. Literature: Chou, C., O. Stetzer, E. Weingartner, Z. Juranyi, Z. A. Kanji, and U. Lohmann (2011), Ice nuclei properties within a Saharan dust event at the Jungfraujoch in the Swiss Alps, Atmos. Chem. Phys., 11(10), 4725-4738, doi:10.5194/acp-11-4725-2011. Wex, H. et al. (2014a) Intercomparing different devices for the investigation of ice nucleating particles using Snomax as test substance, Atmos. Chem. Phys. Discuss. (accepted for ACP), 14, 22321-22384, 2014. Wex, H., P. J. DeMott, Y. Tobo, S. Hartmann, M. Rösch, T. Clauss, L. Tomsche, D. Niedermeier, and F. Stratmann (2014b), Kaolinite particles as ice nuclei: learning from the use of different kaolinite samples and different coatings, Atmos. Chem. Phys., 14, doi:10.5194/acp-14-5529-2014.

  8. 40 CFR 60.482-4 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., 2006 § 60.482-4 Standards: Pressure relief devices in gas/vapor service. (a) Except during pressure releases, each pressure relief device in gas/vapor service shall be operated with no detectable emissions... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standards: Pressure relief devices...

  9. 40 CFR 60.482-4a - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Standards: Pressure relief devices in gas/vapor service. (a) Except during pressure releases, each pressure... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standards: Pressure relief devices in gas/vapor service. 60.482-4a Section 60.482-4a Protection of Environment ENVIRONMENTAL...

  10. 40 CFR 63.165 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Standards: Pressure relief devices in gas/vapor service. (a) Except during pressure releases, each pressure... 40 Protection of Environment 10 2014-07-01 2014-07-01 false Standards: Pressure relief devices in gas/vapor service. 63.165 Section 63.165 Protection of Environment ENVIRONMENTAL PROTECTION...

  11. 40 CFR 60.482-4a - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Standards: Pressure relief devices in gas/vapor service. (a) Except during pressure releases, each pressure... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standards: Pressure relief devices in gas/vapor service. 60.482-4a Section 60.482-4a Protection of Environment ENVIRONMENTAL...

  12. 40 CFR 265.1054 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...: Pressure relief devices in gas/vapor service. (a) Except during pressure releases, each pressure relief... 40 Protection of Environment 26 2011-07-01 2011-07-01 false Standards: Pressure relief devices in gas/vapor service. 265.1054 Section 265.1054 Protection of Environment ENVIRONMENTAL PROTECTION...

  13. 40 CFR 265.1054 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...: Pressure relief devices in gas/vapor service. (a) Except during pressure releases, each pressure relief... 40 Protection of Environment 27 2013-07-01 2013-07-01 false Standards: Pressure relief devices in gas/vapor service. 265.1054 Section 265.1054 Protection of Environment ENVIRONMENTAL PROTECTION...

  14. 40 CFR 60.482-4 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., 2006 § 60.482-4 Standards: Pressure relief devices in gas/vapor service. (a) Except during pressure releases, each pressure relief device in gas/vapor service shall be operated with no detectable emissions... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards: Pressure relief devices...

  15. 40 CFR 60.482-4 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., 2006 § 60.482-4 Standards: Pressure relief devices in gas/vapor service. (a) Except during pressure releases, each pressure relief device in gas/vapor service shall be operated with no detectable emissions... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standards: Pressure relief devices...

  16. 40 CFR 60.482-4 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., 2006 § 60.482-4 Standards: Pressure relief devices in gas/vapor service. (a) Except during pressure releases, each pressure relief device in gas/vapor service shall be operated with no detectable emissions... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standards: Pressure relief devices...

  17. 40 CFR 60.482-4 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., 2006 § 60.482-4 Standards: Pressure relief devices in gas/vapor service. (a) Except during pressure releases, each pressure relief device in gas/vapor service shall be operated with no detectable emissions... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standards: Pressure relief devices...

  18. 40 CFR 60.482-4a - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Standards: Pressure relief devices in gas/vapor service. (a) Except during pressure releases, each pressure... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standards: Pressure relief devices in gas/vapor service. 60.482-4a Section 60.482-4a Protection of Environment ENVIRONMENTAL...

  19. 40 CFR 60.482-4a - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Standards: Pressure relief devices in gas/vapor service. (a) Except during pressure releases, each pressure... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standards: Pressure relief devices in gas/vapor service. 60.482-4a Section 60.482-4a Protection of Environment ENVIRONMENTAL...

  20. 40 CFR 63.165 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Standards: Pressure relief devices in gas/vapor service. (a) Except during pressure releases, each pressure... 40 Protection of Environment 9 2011-07-01 2011-07-01 false Standards: Pressure relief devices in gas/vapor service. 63.165 Section 63.165 Protection of Environment ENVIRONMENTAL PROTECTION...

  1. 40 CFR 63.165 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Standards: Pressure relief devices in gas/vapor service. (a) Except during pressure releases, each pressure... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Standards: Pressure relief devices in gas/vapor service. 63.165 Section 63.165 Protection of Environment ENVIRONMENTAL PROTECTION...

  2. 40 CFR 63.165 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Standards: Pressure relief devices in gas/vapor service. (a) Except during pressure releases, each pressure... 40 Protection of Environment 10 2012-07-01 2012-07-01 false Standards: Pressure relief devices in gas/vapor service. 63.165 Section 63.165 Protection of Environment ENVIRONMENTAL PROTECTION...

  3. 40 CFR 265.1054 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...: Pressure relief devices in gas/vapor service. (a) Except during pressure releases, each pressure relief... 40 Protection of Environment 27 2012-07-01 2012-07-01 false Standards: Pressure relief devices in gas/vapor service. 265.1054 Section 265.1054 Protection of Environment ENVIRONMENTAL PROTECTION...

  4. 40 CFR 60.482-4a - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Standards: Pressure relief devices in gas/vapor service. (a) Except during pressure releases, each pressure... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards: Pressure relief devices in gas/vapor service. 60.482-4a Section 60.482-4a Protection of Environment ENVIRONMENTAL...

  5. 40 CFR 265.1054 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...: Pressure relief devices in gas/vapor service. (a) Except during pressure releases, each pressure relief... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Standards: Pressure relief devices in gas/vapor service. 265.1054 Section 265.1054 Protection of Environment ENVIRONMENTAL PROTECTION...

  6. 40 CFR 63.165 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Standards: Pressure relief devices in gas/vapor service. (a) Except during pressure releases, each pressure... 40 Protection of Environment 10 2013-07-01 2013-07-01 false Standards: Pressure relief devices in gas/vapor service. 63.165 Section 63.165 Protection of Environment ENVIRONMENTAL PROTECTION...

  7. Saturation of hole concentration in carbon-doped GaAs grown by metalorganic chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Watanabe, Noriyuki; Ito, Hiroshi

    1997-12-01

    The behavior of hole concentration in carbon-doped GaAs grown by metalorganic chemical vapor deposition (MOCVD) is investigated using carbon tetrabromide (CBr4) as a C source. The hole concentration tends to saturate at higher CBr4 flow rates in the heavily doped region regardless of growth temperature, V/III ratio and Ga source. This tendency is found to be due to the saturation of C incorporation efficiency, not the deactivation of C acceptors. It is also found that the saturation concentration, which is far lower than the value reported for metalorganic molecular beam epitaxy (MOMBE), is nearly independent of the growth conditions. These results suggest that an additional mechanism other than the solubility limit of carbon into GaAs must be considered to explain the saturation tendency of hole concentration in C-doped GaAs grown by MOCVD.

  8. Vapor pressures and vapor compositions in equilibrium with hypostoichiometric uranium dioxide at high temperatures

    SciTech Connect

    Green, D.W.; Leibowitz, L.

    1981-06-01

    Thermodynamic functions of the gaseous species, thermodynamic functions of the condensed phase, and an oxygen-potential model have been combined to calculate the vapor pressures and vapor compositions in equilibrium with condensed-phase UO/sub 2-x/ for 1500 less than or equal to T less than or equal to 6000 K and 0 less than or equal to x less than or equal to 0.5. A method for extending the oxygen-potential model of Blackburn to the liquid region has been derived and evaluated. New thermodynamic functions of the UO/sub 2/ condensed phase have been derived from the best available data, including the heat capacity recommended by Fink.

  9. Clausius-Clapeyron equation and saturation vapour pressure: simple theory reconciled with practice

    NASA Astrophysics Data System (ADS)

    Koutsoyiannis, Demetris

    2012-03-01

    While the Clausius-Clapeyron equation is very important as it determines the saturation vapour pressure, in practice it is replaced by empirical, typically Magnus-type, equations which are more accurate. It is shown that the reduced accuracy reflects an inconsistent assumption that the latent heat of vaporization is constant. Not only is this assumption unnecessary and excessive, but it is also contradictory to entropy maximization. There is an additional erroneous assumption for the derivation of the Clausius-Clapeyron equation, related to the equality of chemical potentials of the two phases, which does not affect the final result but puts into question the logical coherence of the equation's derivation. Removing these assumptions and using a pure entropy maximization framework we obtain a simple closed solution which is both theoretically consistent and accurate. Our discussion and derivation are relevant to students and specialists in statistical thermophysics and in geophysical sciences, and our results are ready for practical application in physics as well as in such disciplines as hydrology, meteorology and climatology.

  10. Laboratory measurements of the microwave opacity and vapor pressure of sulfuric acid vapor under simulated conditions for the middle atmosphere of Venus

    NASA Technical Reports Server (NTRS)

    Steffes, P. G.

    1985-01-01

    Microwave absorption measurements at wavelengths of 13.4 and 3.6 cm were made in gaseous H2SO4 in a CO2 atmosphere under simulated conditions for the Venus middle atmosphere. The results suggest that abundances of gaseous H2SO4 on the order of 15-30 ppm could account for the absorption observed by radio occultation measurements at these wavelengths. They also imply that such abundances would correspond to saturation vapor pressure existing at or above the 46-48-km range, which correlates with the observed cloud base.

  11. Generation of high concentration aerosols from low vapor pressure compounds

    SciTech Connect

    Blank, T.L.; Velasquez, D.J.; Bechtel, C.L.; Roloff, M.V.

    1987-10-01

    A generation system has been developed and used to produce exposure atmospheres containing respirable aerosols at high concentration (up to 5 mg of test compound per liter in air) from high boiling point, low vapor pressure compounds. Nine compounds were evaluated to demonstrate the effectiveness of the generation system. In each test at least 84% of the particles were in the respirable range (particle size 10 ..mu..m or less) with a mass median aerodynamic diameter of less than 3.2 ..mu..m. The system is easy to operate, reliable, versatile, provides reproducible results and is relatively inexpensive to construct.

  12. Propagation of pore pressure diffusion waves in saturated porous media

    NASA Astrophysics Data System (ADS)

    Yang, Duoxing; Li, Qi; Zhang, Lianzhong

    2015-04-01

    A microscopic 1D analytical model was developed for describing pore pressure diffusion wave propagation in porous media. The pressure diffusion waves, being heavily damped, have relatively slow velocities and short wavelength, and do not exhibit square-law behavior. Investigation on permeability effect on attenuation dispersion and penetration depth indicates that the transition zone in attenuation and penetration depth peak shifts toward low frequency when permeability decreases. Controversially, the transition zone in phase velocity peak shifts toward high frequency when permeability decreases. The high frequency-dependent attenuation of low-frequency waves was well predicted by the pressure diffusion mechanism. At a mass interface, pressure diffusion waves obey an accumulation-depletion law, rather than the reflection-refraction law. Pressure diffusion waves are accelerated and amplified by a space-dependent diffusivity field.

  13. 46 CFR 153.372 - Gauges and vapor return for cargo vapor pressures exceeding 100 kPa (approx. 14.7 psia).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Gauges and vapor return for cargo vapor pressures... COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Venting Systems § 153.372 Gauges and vapor return for cargo vapor pressures exceeding 100 kPa (approx. 14.7 psia). When table 1 references...

  14. 46 CFR 153.372 - Gauges and vapor return for cargo vapor pressures exceeding 100 kPa (approx. 14.7 psia).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Gauges and vapor return for cargo vapor pressures... COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Venting Systems § 153.372 Gauges and vapor return for cargo vapor pressures exceeding 100 kPa (approx. 14.7 psia). When table 1 references...

  15. 46 CFR 153.372 - Gauges and vapor return for cargo vapor pressures exceeding 100 kPa (approx. 14.7 psia).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Gauges and vapor return for cargo vapor pressures exceeding 100 kPa (approx. 14.7 psia...153.372 Gauges and vapor return for cargo vapor pressures exceeding 100 kPa (approx. 14.7...

  16. 46 CFR 153.372 - Gauges and vapor return for cargo vapor pressures exceeding 100 kPa (approx. 14.7 psia).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Gauges and vapor return for cargo vapor pressures exceeding 100 kPa (approx. 14.7 psia...153.372 Gauges and vapor return for cargo vapor pressures exceeding 100 kPa (approx. 14.7...

  17. 46 CFR 153.372 - Gauges and vapor return for cargo vapor pressures exceeding 100 kPa (approx. 14.7 psia).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Gauges and vapor return for cargo vapor pressures exceeding 100 kPa (approx. 14.7 psia...153.372 Gauges and vapor return for cargo vapor pressures exceeding 100 kPa (approx. 14.7...

  18. 46 CFR 153.372 - Gauges and vapor return for cargo vapor pressures exceeding 100 kPa (approx. 14.7 psia).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Gauges and vapor return for cargo vapor pressures exceeding 100 kPa (approx. 14.7 psia...153.372 Gauges and vapor return for cargo vapor pressures exceeding 100 kPa (approx. 14.7...

  19. 46 CFR 153.372 - Gauges and vapor return for cargo vapor pressures exceeding 100 kPa (approx. 14.7 psia).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Gauges and vapor return for cargo vapor pressures exceeding 100 kPa (approx. 14.7 psia...153.372 Gauges and vapor return for cargo vapor pressures exceeding 100 kPa (approx. 14.7...

  20. Precision ozone calibration system based on vapor pressures of ozone

    NASA Technical Reports Server (NTRS)

    Mauersberger, K.; Hanson, D.; Morton, J.

    1987-01-01

    A precision ozone calibration system for stratospheric research has been developed and evaluated. Vapor pressures above solid ozone are mixed with a carrier gas (N2) to produce stratospheric ozone mixing ratios at total pressures of 1 to cover 20 torr. The uncertainty in the ozone mixing ratios is approximately + or - 1.5 percent, the stability of ozone is + or - 0.3 percent. Experiments to be calibrated may sample the gas mixture over a wide range of flow rates; the maximum throughput of gas with corrections of less than 1 percent to ozone is about 200 torr 1/min. A mass spectrometer system continuously monitors the purity and stability of the N2-O3 gas mixture.

  1. New Nickel Vapor Pressure Measurements: Possible Implications for Nebular Condensates

    NASA Technical Reports Server (NTRS)

    Johnson, N. M.; Meibom, A.; Ferguson, F. T.; Nuth, J. A., III

    2004-01-01

    Temperatures high enough to vaporize even refractory solids existed in the midplane of the solar nebula during its earliest evolutionary stages and played an important role in the processing of materials that went into the formation of the inner planets and asteroids. A variety of such high-T materials have been identified in primitive chondritic meteorites. These include chemically zoned FeNi metal grains that are generally believed to have formed directly by gas-solid condensation from a gas of approximately solar composition. These FeNi particles provide important information about the times scales of formation and physical transport mechanisms in the nebula, as well as formation temperature, pressure and gas chemistry. Currently, however, the interpretation of the chemical signatures in these FeNi particles rests on less than perfect information about the condensation sequence of siderophile elements. For example much, if not all, of the thermodynamic data for the vapor pressures of moderately refractory metals , such as Fe, Ni and Co, do not cover the desired temperature range. As a result, quite large extrapolations are needed. These extrapolations can be complex and uncertain due to factors such as oxygen fugacity or the presence of hydrogen gas.

  2. 40 CFR 63.1011 - Pressure relief devices in gas and vapor service standards.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Pressure relief devices in gas and vapor service standards. (a) Compliance schedule. The owner or operator... section, each pressure relief device in gas or vapor service shall be operated with an instrument reading... 40 Protection of Environment 11 2014-07-01 2014-07-01 false Pressure relief devices in gas...

  3. HIGH PRESSURE VAPOR TRANSPORT OF ZnGeP 2 : II. THREEDIMENSIONAL SIMULATION OF GASDYNAMICS UNDER

    E-print Network

    HIGH PRESSURE VAPOR TRANSPORT OF ZnGeP 2 : II. THREE­DIMENSIONAL SIMULATION OF GASDYNAMICS UNDER pressure vapor transport (HPVT) of compound semiconductors is modeled. The modeling is for the growth of II Pascals pressure. Effects of density variations on p­polarized reflectance spectroscopy are also examined

  4. 40 CFR 63.1030 - Pressure relief devices in gas and vapor service standards.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... § 63.1030 Pressure relief devices in gas and vapor service standards. (a) Compliance schedule. The... section, each pressure relief device in gas and vapor service shall be operated with an instrument reading... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Pressure relief devices in gas...

  5. 40 CFR 63.1011 - Pressure relief devices in gas and vapor service standards.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Pressure relief devices in gas and vapor service standards. (a) Compliance schedule. The owner or operator... section, each pressure relief device in gas or vapor service shall be operated with an instrument reading... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Pressure relief devices in gas...

  6. 40 CFR 264.1054 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... relief devices in gas/vapor service. (a) Except during pressure releases, each pressure relief device in... 40 Protection of Environment 27 2012-07-01 2012-07-01 false Standards: Pressure relief devices in gas/vapor service. 264.1054 Section 264.1054 Protection of Environment ENVIRONMENTAL PROTECTION...

  7. 40 CFR 63.1030 - Pressure relief devices in gas and vapor service standards.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... § 63.1030 Pressure relief devices in gas and vapor service standards. (a) Compliance schedule. The... section, each pressure relief device in gas and vapor service shall be operated with an instrument reading... 40 Protection of Environment 11 2014-07-01 2014-07-01 false Pressure relief devices in gas...

  8. 40 CFR 264.1054 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... relief devices in gas/vapor service. (a) Except during pressure releases, each pressure relief device in... 40 Protection of Environment 27 2013-07-01 2013-07-01 false Standards: Pressure relief devices in gas/vapor service. 264.1054 Section 264.1054 Protection of Environment ENVIRONMENTAL PROTECTION...

  9. 40 CFR 264.1054 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... relief devices in gas/vapor service. (a) Except during pressure releases, each pressure relief device in... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Standards: Pressure relief devices in gas/vapor service. 264.1054 Section 264.1054 Protection of Environment ENVIRONMENTAL PROTECTION...

  10. 40 CFR 61.242-4 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... devices in gas/vapor service. (a) Except during pressure releases, each pressure relief device in gas... 40 Protection of Environment 9 2014-07-01 2014-07-01 false Standards: Pressure relief devices in gas/vapor service. 61.242-4 Section 61.242-4 Protection of Environment ENVIRONMENTAL PROTECTION...

  11. Selective Growth of Straight Carbon Nanotubes by Low-Pressure Thermal Chemical Vapor Deposition

    E-print Network

    Hasegawa, Shuji

    Selective Growth of Straight Carbon Nanotubes by Low-Pressure Thermal Chemical Vapor Deposition) were grown by low-pressure thermal chemical vapor deposition using pure ethylene. It was found preferentially bridged between Fe nanoparticles under a low pressure of 100 Pa. Moreover, utilizing this method

  12. 40 CFR 63.1011 - Pressure relief devices in gas and vapor service standards.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Pressure relief devices in gas and vapor service standards. (a) Compliance schedule. The owner or operator... section, each pressure relief device in gas or vapor service shall be operated with an instrument reading... 40 Protection of Environment 11 2013-07-01 2013-07-01 false Pressure relief devices in gas...

  13. 40 CFR 61.242-4 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... devices in gas/vapor service. (a) Except during pressure releases, each pressure relief device in gas... 40 Protection of Environment 9 2013-07-01 2013-07-01 false Standards: Pressure relief devices in gas/vapor service. 61.242-4 Section 61.242-4 Protection of Environment ENVIRONMENTAL PROTECTION...

  14. 40 CFR 63.1011 - Pressure relief devices in gas and vapor service standards.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Pressure relief devices in gas and vapor service standards. (a) Compliance schedule. The owner or operator... section, each pressure relief device in gas or vapor service shall be operated with an instrument reading... 40 Protection of Environment 10 2011-07-01 2011-07-01 false Pressure relief devices in gas...

  15. 40 CFR 61.242-4 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... devices in gas/vapor service. (a) Except during pressure releases, each pressure relief device in gas... 40 Protection of Environment 9 2012-07-01 2012-07-01 false Standards: Pressure relief devices in gas/vapor service. 61.242-4 Section 61.242-4 Protection of Environment ENVIRONMENTAL PROTECTION...

  16. 40 CFR 63.1030 - Pressure relief devices in gas and vapor service standards.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... § 63.1030 Pressure relief devices in gas and vapor service standards. (a) Compliance schedule. The... section, each pressure relief device in gas and vapor service shall be operated with an instrument reading... 40 Protection of Environment 10 2011-07-01 2011-07-01 false Pressure relief devices in gas...

  17. 40 CFR 63.1030 - Pressure relief devices in gas and vapor service standards.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... § 63.1030 Pressure relief devices in gas and vapor service standards. (a) Compliance schedule. The... section, each pressure relief device in gas and vapor service shall be operated with an instrument reading... 40 Protection of Environment 11 2013-07-01 2013-07-01 false Pressure relief devices in gas...

  18. 40 CFR 61.242-4 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... devices in gas/vapor service. (a) Except during pressure releases, each pressure relief device in gas... 40 Protection of Environment 8 2011-07-01 2011-07-01 false Standards: Pressure relief devices in gas/vapor service. 61.242-4 Section 61.242-4 Protection of Environment ENVIRONMENTAL PROTECTION...

  19. 40 CFR 264.1054 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... relief devices in gas/vapor service. (a) Except during pressure releases, each pressure relief device in... 40 Protection of Environment 26 2011-07-01 2011-07-01 false Standards: Pressure relief devices in gas/vapor service. 264.1054 Section 264.1054 Protection of Environment ENVIRONMENTAL PROTECTION...

  20. Contribution of water vapor to slider air-bearing pressure in hard disk drives

    NASA Astrophysics Data System (ADS)

    Ma, Yansheng; Liu, Bo

    2007-05-01

    Water vapor in humid air contributes to slider air-bearing pressure in a totally different way from that of dry air. Water vapor pressure keeps constant in slider-disk interface and is identical to the water vapor pressure outside the interface. The simulated slider flying height and attitude in humid air are different from that in dry air and the higher the relative humidity the bigger the differences.

  1. Temperature/pressure and water vapor sounding with microwave spectroscopy

    NASA Technical Reports Server (NTRS)

    Muhleman, D. O.; Janssen, M. A.; Clancy, R. T.; Gulkis, S.; Mccleese, D. J.; Zurek, R.; Haberle, R. M.; Frerking, M.

    1992-01-01

    Two intense microwave spectra lines exist in the martian atmosphere that allow unique sounding capabilities: water vapor at 183 GHz and the (2-1) rotational line of CO at 230 GHz. Microwave spectra line sounding is a well-developed technique for the Earth's atmosphere for sounding from above from spacecraft and airplanes, and from below from fixed surface sites. Two simple instruments for temperature sounding on Mars (the CO line) and water vapor measurements are described. The surface sounder proposed for the MESUR sites is designed to study the boundary layer water vapor distribution and the temperature/pressure profiles with vertical resolution of 0.25 km up to 1 km with reduced resolution above approaching a scale height. The water channel will be sensitive to a few tenths of a micrometer of water and the temperature profile will be retrieved to an accuracy between 1 and 2 K. The latter is routinely done on the Earth using oxygen lines near 60 GHz. The measurements are done with a single-channel heterodyne receiver looking into a 10-cm mirror that is canned through a range of elevation angles plus a target load. The frequency of the receiver is sweep across the water and CO lines generating the two spectra at about 1-hr intervals throughout the mission. The mass and power for the proposed instrument are 2 kg and 5-8 W continuously. The measurements are completely immune to the atmospheric dust and ice particle loads. It was felt that these measurements are the ultimate ones to properly study the martian boundary layer from the surface to a few kilometers. Sounding from above requires an orbiting spacecraft with multichannel microwave spectrometers such as the instrument proposed for MO by a subset of the authors, a putative MESUR orbiter, and a proposed Discovery mission called MOES. Such an instrument can be built with less than 10 kg and use less than 15 W. The obvious advantage of this approach is that the entire atmosphere can be sounded for temperature and water vapor in a few hours with somewhat better than a scale height resolution. If a bigger mirror is used (greater than 30 cm) limb sounding geometry can be employed and half scale height resolution achieved to altitudes up to at least 60 km. Again, the measurements are immune to dust and ice loads. Water vapor sensitivity of 0.1 micrometer can be achieved (even with a nadir instrument) and temperature profiles retrieved to an accuracy of better than 2 K from the surface to about 60 km. Winds can be measured from the doppler shifts of CO lines in the limb sounding mode.

  2. 46 CFR 39.20-13 - High and low vapor pressure protection for tankships-T/ALL.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false High and low vapor pressure protection for tankships-T... VAPOR CONTROL SYSTEMS Design and Equipment § 39.20-13 High and low vapor pressure protection for tankships—T/ALL. Each tankship vapor collection system must be fitted with a pressure sensing device...

  3. 46 CFR 39.20-13 - High and low vapor pressure protection for tankships-T/ALL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false High and low vapor pressure protection for tankships-T... VAPOR CONTROL SYSTEMS Design and Equipment § 39.20-13 High and low vapor pressure protection for tankships—T/ALL. Each tankship vapor collection system must be fitted with a pressure sensing device...

  4. 46 CFR 39.20-13 - High and low vapor pressure protection for tankships-T/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false High and low vapor pressure protection for tankships-T... VAPOR CONTROL SYSTEMS Design and Equipment § 39.20-13 High and low vapor pressure protection for tankships—T/ALL. Each tankship vapor collection system must be fitted with a pressure sensing device...

  5. Non-canonical mass laws in equilibrium isotopic fractionations: Evidence from the vapor pressure isotope effect of SF6

    E-print Network

    Cartigny, Pierre

    Non-canonical mass laws in equilibrium isotopic fractionations: Evidence from the vapor pressure report experimental observations of the vapor pressure isotope effect, including 33 S/32 S and 34 S/32. That equilibrium involves a reversed vapor pressure isotope effect; i.e., vapor is between 2& and 3& higher in 34 S

  6. Measurement of equilibrium elemental vapor pressures using x-ray induced fluorescense.

    SciTech Connect

    Curry, J. J; Henins, A.; Estupinan, E. G.; Lapatovich, W. P.; Shastri, S. D.

    2011-04-29

    X-ray induced fluorescence is demonstrated as a novel and fast method for measuring vapor pressures at high temperatures and high pressures. As such, it is an excellent complement to the effusion method, which is limited to lower pressures. High-energy synchrotron radiation was used to measure the total densities of Dy in the equilibrium vapor over condensed DyI{sub 3} and Tm in the equilibrium vapor over condensed TmI{sub 3}. Corresponding vapor pressures were determined with measured vapor cell temperatures across a range of vapor pressures of nearly three orders of magnitude, from less than 10{sup 2} Pa to more than 10{sup 4} Pa. Individual data points were obtained in time periods ranging from 10 to 30 s each.

  7. Molecular weight of aquatic fulvic acids by vapor pressure osmometry

    USGS Publications Warehouse

    Aiken, G.R.; Malcolm, R.L.

    1987-01-01

    The molecular weights of aquatic fulvic acids extracted from five rivers were determined by vapor pressure osmometry with water and tetrahydrofuran as solvents. The values obtained ranged from 500 to 950 dallons, indicating that the molecular weights of aquatic fulvic acids are not as great as has been suggested in some other molecular weight studies. The samples were shown to be relatively monodisperse from radii of gyration measurements determined by small angle x-ray scattering. THF affords greater precision and accuracy than H2O in VPO measurements, and was found to be a suitable solvent for the determination of molecular weight of aquatic fulvic acid because it obviates the dissociation problem. An inverse correlation was observed with these samples between the concentration of Ca++ and Mg++ in the river water and the radii of gyration and molecular weights of the corresponding fulvic acid samples. ?? 1987.

  8. The vapor pressures of solid and liquid ozone

    NASA Technical Reports Server (NTRS)

    Hanson, David; Mauersberger, Konrad

    1986-01-01

    Vapor pressures of solid and liquid ozone have been measured over a temperature range 87 to below 66 K. The experiment was performed under flow conditions, and the gas was analyzed by a precision mass spectrometer system. In the range of solid ozone two forms, supercooled and crystalline ozone, were found. A least-square fit of the data for crystalline ozone resulted in the equation log P(torr) = A + B/T, where A = 10.460 and B = -1021.6. The estimated uncertainty of the data is + or - 1.0 percent. A triple-point temperature of 79.6 + or - 0.3 K was found where supercooled and crystalline ozone data intersect.

  9. Vapor pressure dependence of spectral width of EIT in Lambda-level cesium molecular system

    E-print Network

    Hui Chen; Hebin Li; Yuri V. Rostovtsev; Mikhail A. Gubin; Vladimir A. Sautenkov; Marlan O. Scully

    2009-02-16

    We have studied electromagnetically induced transparency (EIT) in diatomic cesium molecules in a vapor cell by using tunable diode lasers. We have observed a sub-natural Lambda-resonance in an absorption molecular band at different cesium vapor pressures. The width of the EIT resonance shows a linear dependence on cesium vapor pressure. Narrow Lambda-resonances in molecules can be used as frequency references for femtosecond laser frequency combs.

  10. 40 CFR 65.111 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...: Pressure relief devices in gas/vapor service. (a) Compliance schedule. The owner or operator shall comply... 40 Protection of Environment 16 2013-07-01 2013-07-01 false Standards: Pressure relief devices in gas/vapor service. 65.111 Section 65.111 Protection of Environment ENVIRONMENTAL PROTECTION...

  11. Method and apparatus to measure vapor pressure in a flow system

    DOEpatents

    Grossman, M.W.; Biblarz, O.

    1991-10-15

    The present invention is directed to a method for determining, by a condensation method, the vapor pressure of a material with a known vapor pressure versus temperature characteristic, in a flow system particularly in a mercury isotope enrichment process. 2 figures.

  12. 40 CFR 65.111 - Standards: Pressure relief devices in gas/vapor service.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...: Pressure relief devices in gas/vapor service. (a) Compliance schedule. The owner or operator shall comply... 40 Protection of Environment 15 2011-07-01 2011-07-01 false Standards: Pressure relief devices in gas/vapor service. 65.111 Section 65.111 Protection of Environment ENVIRONMENTAL PROTECTION...

  13. OPTIMAL DESIGN OF A HIGH PRESSURE ORGANOMETALLIC CHEMICAL VAPOR DEPOSITION REACTOR

    E-print Network

    OPTIMAL DESIGN OF A HIGH PRESSURE ORGANOMETALLIC CHEMICAL VAPOR DEPOSITION REACTOR K.J. BACHMANN simulations as a fundamental design tool in developing a new prototype high pressure organometallic chemical vapor deposition (HPOMCVD) reactor for use in thin film crystal growth. The advantages of such a reactor

  14. Carrier concentration and surface electron accumulation in indium nitride layers grown by high pressure chemical vapor deposition

    E-print Network

    Dietz, Nikolaus

    pressure chemical vapor deposition R. P. Bhatta, B. D. Thoms,a A. Weerasekera, A. G. U. Perera, M. Alevli properties of InN layer grown by high pressure chemical vapor deposition have been studied by high-nitride alloys is challenging under low pressure process conditions due to higher equilibrium vapor pressure

  15. Analysis of crude oil vapor pressures at the U.S. Strategic Petroleum Reserve.

    SciTech Connect

    Rudeen, David Keith; Lord, David L.

    2005-08-01

    Crude oil storage caverns at the U.S. Strategic Petroleum Reserve (SPR) are solution-mined from subsurface salt domes along the U.S. Gulf Coast. While these salt domes exhibit many attractive characteristics for large-volume, long-term storage of oil such as low cost for construction, low permeability for effective fluids containment, and secure location deep underground, they also present unique technical challenges for maintaining oil quality within delivery standards. The vapor pressures of the crude oils stored at SPR tend to increase with storage time due to the combined effects of geothermal heating and gas intrusion from the surrounding salt. This presents a problem for oil delivery offsite because high vapor-pressure oil may lead to excessive atmospheric emissions of hydrocarbon gases that present explosion hazards, health hazards, and handling problems at atmospheric pressure. Recognizing this potential hazard, the U.S. Department of Energy, owner and operator of the SPR, implemented a crude oil vapor pressure monitoring program that collects vapor pressure data for all the storage caverns. From these data, DOE evaluates the rate of change in vapor pressures of its oils in the SPR. Moreover, DOE implemented a vapor pressure mitigation program in which the oils are degassed periodically and will be cooled immediately prior to delivery in order to reduce the vapor pressure to safe handling levels. The work described in this report evaluates the entire database since its origin in 1993, and determines the current levels of vapor pressure around the SPR, as well as the rate of change for purposes of optimizing both the mitigation program and meeting safe delivery standards. Generally, the rate of vapor pressure increase appears to be lower in this analysis than reported in the past and, problematic gas intrusion seems to be limited to just a few caverns. This being said, much of the current SPR inventory exceeds vapor pressure delivery guidelines and must be degassed and cooled in order to meet current delivery standards.

  16. The Observed Relationship Between Water Vapor and Ozone in the Tropical Tropopause Saturation Layer and the Influence of Meridional Transport

    NASA Technical Reports Server (NTRS)

    Selkirk, Henry B.; Schoeberl, M. R.; Olsen, M. A.; Douglass, A. R.

    2011-01-01

    We examine balloonsonde observations of water vapor and ozone from three Ticosonde campaigns over San Jose, Costa Rica [10 N, 84 W] during northern summer and a fourth during northern winter. The data from the summer campaigns show that the uppermost portion of the tropical tropopause layer between 360 and 380 K, which we term the tropopause saturation layer or TSL, is characterized by water vapor mixing ratios from proximately 3 to 15 ppmv and ozone from approximately 50 ppbv to 250 ppbv. In contrast, the atmospheric water vapor tape recorder at 380 K and above displays a more restricted 4-7 ppmv range in water vapor mixing ratio. From this perspective, most of the parcels in the TSL fall into two classes - those that need only additional radiative heating to rise into the tape recorder and those requiring some combination of additional dehydration and mixing with drier air. A substantial fraction of the latter class have ozone mixing ratios greater than 150 ppbv, and with water vapor greater than 7 ppmv this air may well have been transported into the tropics from the middle latitudes in conjunction with high-amplitude equatorial waves. We examine this possibility with both trajectory analysis and transport diagnostics based on HIRDLS ozone data. We apply the same approach to study the winter season. Here a very different regime obtains as the ozone-water vapor scatter diagram of the sonde data shows the stratosphere and troposphere to be clearly demarcated with little evidence of mixing in of middle latitude air parcels.

  17. 46 CFR 153.372 - Gauges and vapor return for cargo vapor pressures exceeding 100 kPa (approx. 14.7 psia).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Gauges and vapor return for cargo vapor pressures exceeding 100 kPa (approx. 14.7 psia). 153.372 Section 153.372 Shipping COAST GUARD, DEPARTMENT OF HOMELAND... return for cargo vapor pressures exceeding 100 kPa (approx. 14.7 psia). When table 1 references...

  18. 46 CFR 153.372 - Gauges and vapor return for cargo vapor pressures exceeding 100 kPa (approx. 14.7 psia).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Gauges and vapor return for cargo vapor pressures exceeding 100 kPa (approx. 14.7 psia). 153.372 Section 153.372 Shipping COAST GUARD, DEPARTMENT OF HOMELAND... return for cargo vapor pressures exceeding 100 kPa (approx. 14.7 psia). When table 1 references...

  19. 46 CFR 153.372 - Gauges and vapor return for cargo vapor pressures exceeding 100 kPa (approx. 14.7 psia).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Gauges and vapor return for cargo vapor pressures exceeding 100 kPa (approx. 14.7 psia). 153.372 Section 153.372 Shipping COAST GUARD, DEPARTMENT OF HOMELAND... return for cargo vapor pressures exceeding 100 kPa (approx. 14.7 psia). When table 1 references...

  20. Low Pressure Metal-Organic Vapor Phase Epitaxy

    NASA Astrophysics Data System (ADS)

    Cho, Joe Sung

    A comprehensive investigation of ZnCdS grown on GaAs by the low pressure metal-organic vapor phase epitaxy (MOVPE) technique has been conducted. Optimization, growth characteristics, film properties, solid-vapor equilibrium and device applications are key issues that have been addressed. The Taguchi method or design of experiments (DOE) approach is taken to determine the effects of process parameters on the crystalline quality of epilayers. Its main advantage over the standard methodology of changing one-factor-at -a-time is the reduction of experimental runs needed to obtain the same precision of information. In addition, DOE can statistically evaluate significance of multi-parameter interactions. Thin ZnCdS films have been grown on (100) and (111) oriented GaAs substrates using diethyl zinc (DEZn), dimethyl cadmium (DMCd) and H_2S. The lowest reported full width at half maximum of peaks obtained from X-ray diffraction spectra has been obtained using this chemistry. Critical process parameters and their setpoints have also been identified that influence the desirable 2-dimensional and undesirable 3-dimensional growth. A nucleation/growth mechanism is presented to explain the preferential initiation of one growth mode over the other. Other growth characteristics including flow mechanics, film thickness uniformity, defect density, crystal structure, solid phase composition and optical purity have been studied as a function of growth parameters. The general growth characteristics highly influence the optical, physical and electrical properties of ZnCdS. The bandgap energy and complex refractive index have been measured by reflectometry and ellipsometry, respectively. Thermal expansion coefficients have been calculated from lattice constant changes at various temperatures. In-situ doping studies have also been performed to determine the maximum electron and hole concentrations. A simple model based on the regular solution approach was developed to explain the solid-vapor equilibrium distribution. For the first time, the interaction parameters for binary II -VI compounds were calculated from Stringfellow's delta lattice parameter model based solely on material properties of II-VI compounds. The results show a good fit to experimental data across a wide range of temperature values. The measured properties of ZnCdS have been used in theoretical calculations of double heterostructure lasers. The complex refractive indices are needed to evaluate the optical confinement of a symmetric three-layer slab waveguide: ZnCdS/ZnSe/ZnCdS. The relationship between the active layer thickness and optical confinement have also been investigated. Bandgap energies along with electron affinities have been used to determine the carrier confinement. Calculations based on photothreshold values confirm these results.

  1. Long shear fractures in CO/sub 2/ lines controlled by regulating saturation, arrest pressures

    SciTech Connect

    Maxey, W.A.

    1986-08-01

    Long shear fractures in liquid CO/sub 2/ pipelines can be controlled by lowering the saturation pressure of the liquid or raising the arrest pressure of the line pipe, or doing both. This is the major conclusion of ductile fracture propagation tests conducted by Battelle Laboratories, Columbus, Ohio. The saturation pressure is reduced by lowering the operating temperature of the pipeline and by removing impurities with lower critical temperatures than CO/sub 2/. The arrest pressure of the pipeline can be elevated by increasing the wall thickness, by increasing the wall thickness, by increasing the material toughness, by decreasing the pipe diameter, by increasing the material's yield strength, or some combination thereof. The Battelle tests further suggested the precracked drop-weight-tear test (DWTT) impact energy as an improved measure of material toughness.

  2. A new ozone standard - The vapor pressure of ozone at liquid argon temperatures

    NASA Technical Reports Server (NTRS)

    Mauersberger, K.; Hanson, D.; Morton, J.

    1985-01-01

    The vapor pressure of ozone has been measured at liquid argon temperatures. At the normal boiling point of argon (-185.9 C) an ozone pressure of 0.0405 torr was obtained with an accuracy of + or - 1.5 percent. Increases and decreases in liquid argon temperatures raised and lowered the ozone vapor pressure, respectively. During the vapor pressure measurements the purity of ozone was monitored with a mass spectrometer. The proposed ozone standard will considerably improve the calibration of experiments for atmospheric research, the determination of absorption cross sections and other laboratory ozone studies.

  3. Hydrogen bonding and vapor pressure isotope effect of deuterioisomeric methanethiols

    SciTech Connect

    Wolff, H.; Szydlowski, J.; Dill-Staffenberger, L.

    1981-04-16

    Wilson parameters, activity coefficients, association constants, and other thermodynamic functions which are derived from isothermal vapor pressure measurements between 223 and 293 K for binary mixtures of CH/sub 3/SH, CH/sub 3/SD, CS/sub 3/SH, and CD/sub 3/SD with n-hexane show the weakness of the hydrogen and the deuterium bonds of methanethiol. As far as these functions depend on the association model used for the calculation, the relation of their values to those obtained for the corresponding amines and alcohols under the same conditions attests the weak methanethiol association. While for the more strongly associated methylamines and methanols a greater energy of the deuterium bond compared to the hydrogen bond has clearly been observed, the differences between the thermodynamic functions of the systems with the SH compounds and of those with the SD compounds are insignificant. This observation as well as the fact that the vapor pressure ratios P-(CH/sub 3/SD)/P(CH/sub 3/SH) are only slightly greater than unity, that the ratios P(CD/sub 3/SD)/P(CH/sub 3/SH) are even greater than P(CD/sub 3/SH)/P(CH/sub 3/SH), and that the changes of these ratios with temperature and dilution are small in comparison to the strong increase of the corresponding quotients of the methylamines and the methanols are the consequence of the weak methanethiol association. P(CH/sub 3/SD)/P(CH/sub 3/SH), P(CD/sub 3/SH)/P(CH/sub 3/SH), and P(CD/sub 3/SD)/P(CH/sub 3/SH) are represented by equations of the type ln P/sub D/ P/sub H/ = -A/T/sup 2/ + B/T where A and B are nearly additive. The low values of A and B for CH/sub 3/SD/CH/sub 3/SH in comparison to the high values for CH/sub 3/ND/sub 2//CH/sub 3/NH/sub 2/ and CH/sub 3/OD/CH/sub 3/OH reflect the weakness of the methanethiol hydrogen bonds. The constants can be related to the thermochemical and the spectroscopic data reported in the literature.

  4. MODEL FOR HYSTERETIC CONSTITUTIVE RELATIONS GOVERNING MULTIPHASE FLOW. 1. SATURATION-PRESSURE RELATIONS

    EPA Science Inventory

    In these companion papers, a general theoretical model is presented for the description of functional relationships between relative permeability k, fluid saturation S, and pressure P in two- or three-phase (e.g., air-water or air-oil-water) porous media systems subject to arbitr...

  5. MEASUREMENT AND PREDICTION OF SATURATION-PRESSURE RELATIONSHIPS IN THREE-PHASE POROUS MEDIA SYSTEMS

    EPA Science Inventory

    Scaled multiphase versions of the Brooks-Corey and van Genuchten retention functions were used to describe saturation-capillary pressure curves measured in air-water, air-organic liquid and organic liquid-water systems in a sandy porous medium for four organic liquids during mono...

  6. Pressure and fluid saturation prediction in a multicomponent reservoir, using combined seismic and electromagnetic imaging

    SciTech Connect

    Hoversten, G.M.; Gritto, Roland; Washbourne, John; Daley, Tom

    2002-06-10

    This paper presents a method for combining seismic and electromagnetic measurements to predict changes in water saturation, pressure, and CO{sub 2} gas/oil ratio in a reservoir undergoing CO{sub 2} flood. Crosswell seismic and electromagnetic data sets taken before and during CO{sub 2} flooding of an oil reservoir are inverted to produce crosswell images of the change in compressional velocity, shear velocity, and electrical conductivity during a CO{sub 2} injection pilot study. A rock properties model is developed using measured log porosity, fluid saturations, pressure, temperature, bulk density, sonic velocity, and electrical conductivity. The parameters of the rock properties model are found by an L1-norm simplex minimization of predicted and observed differences in compressional velocity and density. A separate minimization, using Archie's law, provides parameters for modeling the relations between water saturation, porosity, and the electrical conductivity. The rock-properties model is used to generate relationships between changes in geophysical parameters and changes in reservoir parameters. Electrical conductivity changes are directly mapped to changes in water saturation; estimated changes in water saturation are used along with the observed changes in shear wave velocity to predict changes in reservoir pressure. The estimation of the spatial extent and amount of CO{sub 2} relies on first removing the effects of the water saturation and pressure changes from the observed compressional velocity changes, producing a residual compressional velocity change. This velocity change is then interpreted in terms of increases in the CO{sub 2}/oil ratio. Resulting images of the CO{sub 2}/oil ratio show CO{sub 2}-rich zones that are well correlated to the location of injection perforations, with the size of these zones also correlating to the amount of injected CO{sub 2}. The images produced by this process are better correlated to the location and amount of injected CO{sub 2} than are any of the individual images of change in geophysical parameters.

  7. Sodium vapor flow regimes and pressure losses on cathode side of multitube AMTEC cell

    NASA Astrophysics Data System (ADS)

    Tournier, Jean-Michel; El-Genk, Mohamed S.

    1998-01-01

    A model was developed to calculate the vapor pressure losses and characterize the vapor flow regimes on the cathode side of multitube vapor-anode AMTEC cells, with internal chevrons radiation shields and TiN electrodes. Results showed that the vapor flow on the cathode side of the AMTEC cells was typically in the transition regime, and that the pressure losses due to the chevrons shield constituted about 50% of the total pressure loss. Such an increase in the vapor pressure losses, however, decreased the cell electrical power output by only about 5%, because the concentration losses in the cell were small compared to the charge-exchange polarization and internal ohmic losses.

  8. U.S. Strategic Petroleum Reserve Vapor Pressure Committee 2009 annual report.

    SciTech Connect

    Allen, Ray; Eldredge, Lisa; DeLuca, Charles; Mihalik, Patrick; Maldonado, Julio; Lord, David L.; Rudeen, David Keith; Berndsen, Gerard

    2010-05-01

    This report comprises an annual summary of activities under the U.S. Strategic Petroleum Reserve (SPR) Vapor Pressure Committee in FY2009. The committee provides guidance to senior project management on the issues of crude oil vapor pressure monitoring nd mitigation. The principal objectives of the vapor pressure program are, in the event of an SPR drawdown, to minimize the impact on the environment and assure worker safety and public health from crude oil vapor emissions. The annual report reviews key program areas ncluding monitoring program status, mitigation program status, new developments in measurements and modeling, and path forward including specific recommendations on cavern sampling for the next year. The contents of this report were first presented to SPR senior anagement in December 2009, in a deliverable from the vapor pressure committee. The current SAND report is an adaptation for the Sandia technical audience.

  9. PEO/CHCl3: Crystallinity of the polymer and vapor pressure of the solvent - Equilibrium and non-equilibrium phenomena -

    E-print Network

    A. KHassanova; B. A. Wolf

    2003-04-16

    Vapor pressures were measured for the system chloroform/polyethylene oxide (peo, weight average molar mass = 1000 kg/mol) at 25 degrees centigrade as a function of the weight fraction w of the polymer by means of a combination of head space sampling and gas chromatography. The establishment of thermodynamic equilibria was assisted by employing thin polymer films. The degrees of crystallinity alpha of the pure peo and of the solid polymer contained in the mixtures were determined via dsc. An analogous degree of polymer insolubility, beta, was calculated from the vapor pressures measured in this composition range. The experiments demonstrate that both quantities and their concentration dependence are markedly affected by the particular mode of film preparation. These non-equilibrium phenomena are discussed in terms of frozen local and temporal equilibria, where differences between alpha and beta are attributed to the occlusion of amorphous material within crystalline domains. Equilibrium information was obtained from two sources, namely from the vapor pressures in the absence of crystalline material (gas/liquid) and from the saturation concentration of peo (liquid/solid). The thermodynamic consistency of these data is demonstrated using a new approach that enables the modeling of composition dependent interaction parameters by means of two adjustable parameters only.

  10. Pluto's atmosphere - Models based on refraction, inversion, and vapor-pressure equilibrium

    NASA Technical Reports Server (NTRS)

    Eshleman, Von R.

    1989-01-01

    Viking spacecraft radio-occultation measurements indicate that, irrespective of substantial differences, the polar ice cap regions on Mars have inversions similar to those of Pluto, and may also share vapor pressure equilibrium characteristics at the surface. This temperature-inversion phenomenon occurs in a near-surface boundary layer; surface pressure-temperature may correspond to the vapor-pressure equilibrium with CH4 ice, or the temperature may be slightly higher to match the value derived from IRAS data.

  11. Thermodynamic Properties of Nitrogen Including Liquid and Vapor Phases from 63K to 2000K with Pressures to 10,000 Bar

    NASA Technical Reports Server (NTRS)

    Jacobsen, Richard T.; Stewart, Richard B.

    1973-01-01

    Tables of thermodynamic properties of nitrogen are presented for the liquid and vapor phases for temperatures from the freezing line to 2000K and pressures to 10,000 bar. The tables include values of density, internal energy, enthalpy, entropy, isochoric heat capacity, isobaric heat capacity velocity of sound, the isotherm derivative, and the isochor derivative. The thermodynamic property tables are based on an equation of state, P=P (p,T), which accurately represents liquid and gaseous nitrogen for the range of pressures and temperatures covered by the tables. Comparisons of property values calculated from the equation of state with measured values for P-p-T, heat capacity, enthalpy, latent heat, and velocity of sound are included to illustrate the agreement between the experimental data and the tables of properties presented here. The coefficients of the equation of state were determined by a weighted least squares fit to selected P-p-T data and, simultaneously, to isochoric heat capacity data determined by corresponding states analysis from oxygen data, and to data which define the phase equilibrium criteria for the saturated liquid and the saturated vapor. The vapor pressure equation, melting curve equation, and an equation to represent the ideal gas heat capacity are also presented. Estimates of the accuracy of the equation of state, the vapor pressure equation, and the ideal gas heat capacity equation are given. The equation of state, derivatives of the equation, and the integral functions for calculating derived thermodynamic properties are included.

  12. Effects of High Water Vapor Pressures on the Oxidation of SiC-Based Fiber-Reinforced Composites

    E-print Network

    Pennycook, Steve

    Effects of High Water Vapor Pressures on the Oxidation of SiC-Based Fiber-Reinforced Composites K) and elevated total water vapor pressures (up to 1.5 atm) was studied. Substantial degradation of SiC composites oxidation behavior of the different composites at high water vapor pressures can be explained based

  13. 46 CFR 39.20-13 - High and low vapor pressure protection for tankships-T/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 false High and low vapor pressure protection for tankships-T...39.20-13 High and low vapor pressure protection for tankships—T...sensing device that senses the pressure in the main vapor collection line, which:...

  14. 46 CFR 39.20-13 - High and low vapor pressure protection for tankships-T/ALL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 false High and low vapor pressure protection for tankships-T...39.20-13 High and low vapor pressure protection for tankships—T...sensing device that senses the pressure in the main vapor collection line, which:...

  15. 46 CFR 39.20-13 - High and low vapor pressure protection for tankships-T/ALL.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 false High and low vapor pressure protection for tankships-T...39.20-13 High and low vapor pressure protection for tankships—T...sensing device that senses the pressure in the main vapor collection line, which:...

  16. Total sulfur dioxide emissions and pre-eruption vapor-saturated magma at Mount St. Helens, 1980-88

    SciTech Connect

    Gerlach, T.M.; McGee, K.A.

    1994-12-15

    SO{sub 2} from explosive volcanism can cause significant climatic and atmospheric impacts, but the source of the sulfur is controversial. TOMS, COSPEC, and ash leachate data for Mount St. Helens from the time of the climactic eruption on 18 May 1980 to the final stages of non-explosive degassing in 1988 give a total SO{sub 2} emission of 2 Mt. COSPEC data show a sharp drop in emission rate that was apparently controlled by a decreasing rate of magma supply. A total SO{sub 2} emission of only 0.08 Mt is estimated from melt inclusion data and the conventional assumption that the main sulfur source was pre-eruption melt; commonly invoked sources of {open_quotes}excess sulfur{close_quotes} (anhydrite decomposition, basaltic magma, and degassing of non-erupted magma) are unlikely in this case. Thus melt inclusions may significantly underestimate SO{sub 2} emissions and impacts of explosive volcanism on climate and the atmosphere. Measured CO{sub 2} emissions, together with the H{sub 2}O content of melt inclusions and experimental solubility data, indicate the Mount St. Helens dacite was vapor-saturated at depth prior to ascent and suggest that a vapor phase was the main source of sulfur for the 2-Mt of SO{sub 2}. A vapor source is consistent with experimental studies on the Mount St. Helens dacite and removes the need for a much debated shallow magma body. 23 refs., 3 figs.

  17. PHOTOLYSIS OF ARYL KETONES WITH VARYING VAPOR PRESSURE ON SOIL

    EPA Science Inventory

    The photolysis of a series of aryl ketones on air-dried soil surfaces was examined to establish whether vapor transport has an effect on the rate and extent of photolysis. f vapor transport were significant on light-exposed soils, then differences in the observed photolysis rate ...

  18. Estimates of vapor pressure below the triple point for the LJ system

    NASA Astrophysics Data System (ADS)

    Hale, Barbara N.

    2010-03-01

    Vapor pressures are estimated for a full Lennard-Jones (LJ) potential system at three temperatures below the triple point. A Bennett Monte Carlo calculation of Helmholtz free energy differences for small LJ n-atom clusters is used to predict (?liq/?1), the intercept at n=?, where ?liq and ?1 are bulk liquid and monomer vapor number densities. The approximation that the vapor consists of monomers only provides an estimate of (P)/Pc). The results are presented in a corresponding states plot comparison with experimental data for argon at higher temperatures, the extrapolated vapor pressure formula used by Iland et al [K. Lland, J. W"olk and R. Strey, J. Chem. Phys. 127, 54506 (2007)], and Monte Carlo results of Chen et al. [B. Chen, J. I. Siepmann, K. J. Oh, M. L. Klein, J. Chem. Phys. 115, 10903 (2001)] Such a plot provides a check on vapor pressure expressions extrapolated to low temperatures where no experimental data are available.

  19. Oxygen saturation changes in the optic nerve head during acute intraocular pressure elevation in monkeys

    NASA Astrophysics Data System (ADS)

    Khoobehi, Bahram; Kawano, Hiroyuki; Ning, Jinfeng; Burgoyne, Claude F.; Rice, David A.; Khan, Fareeha; Thompson, Hilary W.; Beach, James M.

    2009-02-01

    Background and Objective: To evaluate the effect of an acute elevated intraocular pressure (IOP) on oxygen saturation of structures of the optic nerve head. Study Design/Materials and Methods: In the cynomolgus monkey eye, IOP was set to 10 mm Hg, and then raised to 30, 45, and 55 mm Hg. The ONH and overlying vessels were imaged using a fundus camera attached to a hyperspectral imaging system (HSI) at 10 and 30 minutes after IOP elevation. Results: Raising IOP from 10 to 30 mm Hg did not significantly (P < 0.0001) change saturation in vessels or ONH tissue structures but at 55 mm Hg, all structures showed significant reduction. Conclusions: Quantitative assay of the blood oxygen saturation in structures on the surface and overlying the optic nerve head is possible using hyperspectral imaging techniques.

  20. Chemically enhanced mixed region vapor stripping of TCE-contaminated saturated peat and silty clay soils

    SciTech Connect

    West, O.R.; Cameron, P.A.; Lucero, A.J.; Koran, L.J. Jr.

    1996-01-01

    The objective of this study was to conduct further testing of MRVS, chemically enhanced with calcium oxide conditioning, on field- contaminated soils collected from beneath the NASA Michoud Rinsewater Impoundment. In this study, residual soil VOC levels as a function of vapor stripping time were measured to quantify VOC removal rates. Physical and chemical soil parameters expected to affect MRVS efficiency were measures. The effects of varying the calcium oxide loadings as well as varying the vapor stripping flow rates on VOC removal were also evaluated. The results of this study will be used to determine whether acceptable removals can be achieved within reasonable treatment times, remediation costs being directly proportional to the latter. The purpose of this report is to document the experimental results of this study, as well as to address issues that were raised after completion of the previous Michoud treatability work.

  1. Temperature and saturation dependence in the vapor sensing of butterfly wing scales.

    PubMed

    Kertész, K; Piszter, G; Jakab, E; Bálint, Zs; Vértesy, Z; Biró, L P

    2014-06-01

    The sensing of gasses/vapors in the ambient air is the focus of attention due to the need to monitor our everyday environment. Photonic crystals are sensing materials of the future because of their strong light-manipulating properties. Natural photonic structures are well-suited materials for testing detection principles because they are significantly cheaper than artificial photonic structures and are available in larger sizes. Additionally, natural photonic structures may provide new ideas for developing novel artificial photonic nanoarchitectures with improved properties. In the present paper, we discuss the effects arising from the sensor temperature and the vapor concentration in air during measurements with a photonic crystal-type optical gas sensor. Our results shed light on the sources of discrepancy between simulated and experimental sensing behaviors of photonic crystal-type structures. Through capillary condensation, the vapors will condensate to a liquid state inside the nanocavities. Due to the temperature and radius of curvature dependence of capillary condensation, the measured signals are affected by the sensor temperature as well as by the presence of a nanocavity size distribution. The sensing materials used are natural photonic nanoarchitectures present in the wing scales of blue butterflies. PMID:24863219

  2. Accurate determination of the vapor pressure of potassium using optical absorption

    NASA Technical Reports Server (NTRS)

    Shirinzadeh, B.; Wang, C. C.

    1983-01-01

    The vapor pressure of potassium has been measured in absorption using a CW tunable laser and calibrated against the accurate radiative lifetime of the 4s-4p doublet of potassium. An accurate value of 20,850 + or - 30 cal/mol for the heat of vaporization (from the liquid phase) at the melting point was determined.

  3. Vapor Pressure of Hexamethylene Triperoxide Diamine (HMTD) Estimated Using Secondary Electrospray Ionization Mass Spectrometry.

    PubMed

    Aernecke, Matthew J; Mendum, Ted; Geurtsen, Geoff; Ostrinskaya, Alla; Kunz, Roderick R

    2015-11-25

    A rapid method for vapor pressure measurement was developed and used to derive the vapor pressure curve of the thermally labile peroxide-based explosive hexamethylene triperoxide diamine (HMTD) over the temperature range from 28 to 80 °C. This method uses a controlled flow of vapor from a solid-phase HMTD source that is presented to an ambient-pressure-ionization mass spectrometer equipped with a secondary-electrospray-ionization (SESI) source. The subpart-per-trillion sensitivity of this system enables direct detection of HMTD vapor through an intact [M + H](+) ion in real time at temperatures near 20 °C. By calibrating this method using vapor sources of cocaine and heroin, which have known pressure-temperature (P-T) curves, the temperature dependence of HMTD vapor was determined, and a Clausius-Clapeyron plot of ln[P (Pa)] vs 1/[T (K)] yielded a straight line with the expression ln[P (Pa)] = {(-11091 ± 356) × 1/[T (K)]} + 25 ± 1 (error limits are the standard error of the regression analysis). From this equation, the sublimation enthalpy of HMTD was estimated to be 92 ± 3 kJ/mol, which compares well with the theoretical estimate of 95 kJ/mol, and the vapor pressure at 20 °C was estimated to be ?60 parts per trillion by volume, which is within a factor of 2 of previous theoretical estimates. Thus, this method provides not only the first direct experimental determination of HMTD vapor pressure but also a rapid, near-real-time capability to quantitatively measure low-vapor-pressure compounds, which will be useful for aiding in the development of training aids for bomb-sniffing canines. PMID:26505487

  4. Determination of Vapor Pressure-Temperature Relationships of Current Use Pesticides and Transformation Products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sub-cooled liquid vapor pressures of current use organochlorine and organophosphate pesticides (chlorothalonil, chlorpyrifos methyl, diazinon, fipronil) and selected transformation products (chlorpyrifos oxon, heptachlor epoxide, oxychlordane, 3,5,6-trichloro-2-pyridinol) were determined at multiple...

  5. Single- and few-layer graphene by ambient pressure chemical vapor deposition on nickel

    E-print Network

    Reina Ceeco, Alfonso

    2010-01-01

    An ambient pressure chemical vapor deposition (APCVD) process is used to fabricate graphene based films consisting of one to several graphene layers across their area. Polycrystalline Ni thin films are used and the graphene ...

  6. The Oxidation Rate of SiC in High Pressure Water Vapor Environments

    NASA Technical Reports Server (NTRS)

    Opila, Elizabeth J.; Robinson, R. Craig

    1999-01-01

    CVD SiC and sintered alpha-SiC samples were exposed at 1316 C in a high pressure burner rig at total pressures of 5.7, 15, and 25 atm for times up to 100h. Variations in sample emittance for the first nine hours of exposure were used to determine the thickness of the silica scale as a function of time. After accounting for volatility of silica in water vapor, the parabolic rate constants for Sic in water vapor pressures of 0.7, 1.8 and 3.1 atm were determined. The dependence of the parabolic rate constant on the water vapor pressure yielded a power law exponent of one. Silica growth on Sic is therefore limited by transport of molecular water vapor through the silica scale.

  7. Relating oxygen partial pressure, saturation and content: the haemoglobin–oxygen dissociation curve

    PubMed Central

    Rudenski, Aram; Gibson, John; Howard, Luke; O’Driscoll, Ronan

    2015-01-01

    Key Points In clinical practice, the level of arterial oxygenation can be measured either directly by blood gas sampling to measure partial pressure (PaO2) and percentage saturation (SaO2) or indirectly by pulse oximetry (SpO2). This review addresses the strengths and weaknesses of each of these tests and gives advice on their clinical use. The haemoglobin–oxygen dissociation curve describing the relationship between oxygen partial pressure and saturation can be modelled mathematically and routinely obtained clinical data support the accuracy of a historical equation used to describe this relationship. Educational Aims To understand how oxygen is delivered to the tissues. To understand the relationships between oxygen saturation, partial pressure, content and tissue delivery. The clinical relevance of the haemoglobin–oxygen dissociation curve will be reviewed and we will show how a mathematical model of the curve, derived in the 1960s from limited laboratory data, accurately describes the relationship between oxygen saturation and partial pressure in a large number of routinely obtained clinical samples. To understand the role of pulse oximetry in clinical practice. To understand the differences between arterial, capillary and venous blood gas samples and the role of their measurement in clinical practice. The delivery of oxygen by arterial blood to the tissues of the body has a number of critical determinants including blood oxygen concentration (content), saturation (SO2) and partial pressure, haemoglobin concentration and cardiac output, including its distribution. The haemoglobin–oxygen dissociation curve, a graphical representation of the relationship between oxygen satur­ation and oxygen partial pressure helps us to understand some of the principles underpinning this process. Historically this curve was derived from very limited data based on blood samples from small numbers of healthy subjects which were manipulated in vitro and ultimately determined by equations such as those described by Severinghaus in 1979. In a study of 3524 clinical specimens, we found that this equation estimated the SO2 in blood from patients with normal pH and SO2 >70% with remarkable accuracy and, to our knowledge, this is the first large-scale validation of this equation using clinical samples. Oxygen saturation by pulse oximetry (SpO2) is nowadays the standard clinical method for assessing arterial oxygen saturation, providing a convenient, pain-free means of continuously assessing oxygenation, provided the interpreting clinician is aware of important limitations. The use of pulse oximetry reduces the need for arterial blood gas analysis (SaO2) as many patients who are not at risk of hypercapnic respiratory failure or metabolic acidosis and have acceptable SpO2 do not necessarily require blood gas analysis. While arterial sampling remains the gold-standard method of assessing ventilation and oxygenation, in those patients in whom blood gas analysis is indicated, arterialised capillary samples also have a valuable role in patient care. The clinical role of venous blood gases however remains less well defined. PMID:26632351

  8. Calculation of the Dimer Equilibrium Constant of Heavy Water Saturated Vapor

    E-print Network

    L. A. Bulavin; S. V. Khrapatiy; V. N. Makhlaichuk

    2015-03-13

    Water is the most common substance on Earth.The discovery of heavy water and its further study have shown that the change of hydrogen for deuterium leads to the significant differences in their properties.The triple point temperature of heavy water is higher,at the same time the critical temperature is lower.Experimental values of the second virial coefficient of the EOS for the vapor of normal and heavy water differ at all temperatures.This fact can influence the values of the dimerization constant for the heavy water vapor.The equilibrium properties of the dimerization process are described with the methods of chemical thermodynamics.The chemical potentials for monomers (m) and dimers (d)are the functions of their concentrations.The interactions of monomer-dimer and dimer-dimer types are taken into account within the solution of equation for chemical potentials.The obtained expression for the dimerization constant contains the contributions of these types.The averaged potentials are modeled by the Sutherland potential.Theoretical values of the dimerization constant for the heavy water vapor at different temperatures are compared to those for normal water.We see the exceeding of the values for the heavy water at all temperatures.This fact is in good agreement with all experimental data that is available.The excess is related to the differences in the character of the heat excitations of the dimers of normal and heavy water,their rotational constants and energy of their vibrational excitations.Significant role is also played by the monomer-dimer and dimer-dimer interactions.

  9. Sound Propagation in Saturated Gas-Vapor-Droplet Suspensions Considering the Effect of Transpiration on Droplet Evaporation

    NASA Technical Reports Server (NTRS)

    Kandula, Max

    2012-01-01

    The Sound attenuation and dispersion in saturated gas-vapor-droplet mixtures with evaporation has been investigated theoretically. The theory is based on an extension of the work of Davidson (1975) to accommodate the effects of transpiration on the linear particle relaxation processes of mass, momentum and energy transfer. It is shown that the inclusion of transpiration in the presence of mass transfer improves the agreement between the theory and the experimental data of Cole and Dobbins (1971) for sound attenuation in air-water fogs at low droplet mass concentrations. The results suggest that transpiration has an appreciable effect on both sound absorption and dispersion for both low and high droplet mass concentrations.

  10. Liquid-propellant droplet vaporization and combustion in high pressure environments

    NASA Technical Reports Server (NTRS)

    Yang, Vigor

    1991-01-01

    In order to correct the deficiencies of existing models for high-pressure droplet vaporization and combustion, a fundamental investigation into this matter is essential. The objective of this research are: (1) to acquire basic understanding of physical and chemical mechanisms involved in the vaporization and combustion of isolated liquid-propellant droplets in both stagnant and forced-convective environments; (2) to establish droplet vaporization and combustion correlations for the study of liquid-propellant spray combustion and two-phase flowfields in rocket motors; and (3) to investigate the dynamic responses of multicomponent droplet vaporization and combustion to ambient flow oscillations.

  11. Determination of vapor pressures for nonpolar and semipolar organic compounds from gas chromatographic retention data

    USGS Publications Warehouse

    Hinckley, D.A.; Bidleman, T.F.; Foreman, W.T.; Tuschall, J.R.

    1990-01-01

    Vapor pressures for nonpolar and moderately polar organochlorine, pyrethroid, and organophosphate insecticides, phthalate esters, and organophosphate flame retardants were determined by capillary gas chromatography (GC). Organochlorines and polycyclic aromatic hydrocarbons with known liquid-phase vapor pressures (P??L) (standard compounds) were chromatographed along with two reference compounds n-C20 (elcosane) and p,p???-DDT on a 1.0-m-long poly(dimethylsiloxane) bonded-phase (BP-1) column to determine their vapor pressures by GC (P??GC). A plot of log P??L vs log P??GC for standard compounds was made to establish a correlation between measured and literature values, and this correlation was then used to compute P??L of test compounds from their measured P??GC. P??L of seven major components of technical chlordane, endosulfan and its metabolites, ??-hexachlorocyclohexane, mirex, and two components of technical toxaphene were determined by GC. This method provides vapor pressures within a factor of 2 of average literature values for nonpolar compounds, similar to reported interlaboratory precisions of vapor pressure determinations. GC tends to overestimate vapor pressures of moderately polar compounds. ?? 1990 American Chemical Society.

  12. Dynamic testing of concrete under high confined pressure. Influence of saturation ratio and aggregate size

    NASA Astrophysics Data System (ADS)

    Forquin, P.; Piotrowska, E.; Gary, G.

    2015-09-01

    Concrete structures can be exposed to intense pressure loadings such as projectile-impact or detonation near a concrete structural element. To investigate the mechanical behaviour of concrete under high confining pressure, dynamic quasi-oedometric compression tests have been performed with a large diameter (80 mm) Split Hopkinson Pressure Bar apparatus. The concrete sample is placed within a steel confining ring and compressed along its axial direction. Hydrostatic pressures as high as 800 MPa and axial strain of about - 10% are reached during the tests. In the present work, experiments have been conducted on two types of concrete: MB50 microconcrete with a maximum grain size of 2 mm and R30A7 ordinary concrete of maximum grain size about 8 mm. Both concretes are tested in dry or saturated conditions. According to these dynamic experiments it is noted that grain size has a small influence whereas water content has a strong effect on the confined behaviour of concrete.

  13. Elasticity of water-saturated rocks as a function of temperature and pressure.

    NASA Technical Reports Server (NTRS)

    Takeuchi, S.; Simmons, G.

    1973-01-01

    Compressional and shear wave velocities of water-saturated rocks were measured as a function of both pressure and temperature near the melting point of ice to confining pressure of 2 kb. The pore pressure was kept at about 1 bar before the water froze. The presence of a liquid phase (rather than ice) in microcracks of about 0.3% porosity affected the compressional wave velocity by about 5% and the shear wave velocity by about 10%. The calculated effective bulk modulus of the rocks changes rapidly over a narrow range of temperature near the melting point of ice, but the effective shear modulus changes gradually over a wider range of temperature. This phenomenon, termed elastic anomaly, is attributed to the existence of liquid on the boundary between rock and ice due to local stresses and anomalous melting of ice under pressure.

  14. Saturated fluorescence measurements of the hydroxyl radical in laminar high-pressure flames

    NASA Technical Reports Server (NTRS)

    Carter, Campbell D.; King, Galen B.; Laurendeau, Normand M.

    1990-01-01

    The efficacy of laser saturated fluorescence (LSF) for OH concentration measurements in high pressure flames was studied theoretically and experimentally. Using a numerical model describing the interaction of hydroxyl with nonuniform laser excitation, the effect of pressure on the validity of the balanced cross-rate model was studied along with the sensitivity of the depopulation of the laser-coupled levels to the ratio of rate coefficients describing: (1) electronic quenching to (sup 2) Sigma (+) (v double prime greater than 0), and (2) vibrational relaxation from v double prime greater than 0 to v double prime = 0. At sufficiently high pressures and near-saturated conditions, the total population of the laser-coupled levels reaches an asymptotic value, which is insensitive to the degree of saturation. When the ratio of electronic quenching to vibrational relaxation is small and the rate of coefficients for rotational transfer in the ground and excited electronic states are nearly the same, the balanced cross-rate model remains a good approximation for all pressures. When the above ratio is large, depopulation of the laser-coupled levels becomes significant at high pressures, and thus the balanced cross-rate model no longer holds. Under these conditions, however, knowledge of the depletion of the laser-coupled levels can be used to correct the model. A combustion facility for operation up to 20 atm was developed to allow LSF measurements of OH in high pressure flames. Using this facility, partial saturation in laminar high pressure (less than or equal to 12.3 atm) C2H6/O2/N2 flames was achieved. To evaluate the limits of the balanced cross-rate model, absorption and calibrated LSF measurements at 3.1 and 6.1 atm were compared. The fluorescence voltages were calibrated with absorption measurements in an atmospheric flame and corrected for their finite sensitivity to quenching with: (1) estimated quenching rate coefficients, and (2) an in situ measurement from a technique employing two fluorescence detection geometries.

  15. The influence of surfactant sorption on capillary pressure-saturation relationships

    SciTech Connect

    Desai, F.N.; Demond, A.H.; Hayes, K.F.

    1991-12-31

    The capillary pressure-saturation relationship, a fundamental relationship in the description of multiphase flow, depends on the interfacial properties of the system. Sorption of a cationic surfactant such as cetyltrimethylammonium bromide (CTAB) at the various interfaces of a system changes interfacial properties such as electrophoretic mobility, interfacial tensions, and contact angle. The objective of this paper is to examine the effect of the changes in these interfacial properties on the capillary pressure-saturation relationships for the air-water-silica system. The results presented here show that as the sorption of CTAB increases, the naturally negatively-charged silica surface becomes positively charged. This change in charge is reflected in the contact angle which passes through a maximum when the electrophoretic mobility is close to zero. The spontaneous imbibition capillary pressure relationship is more sensitive to changes in interfacial properties than the drainage relationship. In the air-water-silica system studied here, no imbibition is observed at the maximum contact angle. The surface tension and contact angle can be used to predict both the drainage and imbibition relationships of the air-water-silica-CTAB systems from that of the air-water-silica system. The prediction is accomplished through scaling using the value of surface tension and the operational contact angle, which can be obtained from the intrinsic angle through the incorporation of corrections for roughness and interfacial curvature. A comparison of the measured and calculated capillary pressure relationships shows that it is possible to predict the effect of surfactant sorption on both drainage and imbibition capillary pressure-saturation relationships for the system studied.

  16. A new theoretical method for calculating temperature and water vapor saturation ratio in an expansion cloud chamber

    NASA Astrophysics Data System (ADS)

    Moteki, Nobuhiro; Kondo, Yutaka

    2013-06-01

    The expansion cloud chamber is a widely used apparatus for investigating the dynamics of condensational growth of aerosols and clouds. Theoretical calculations of temperature T and water vapor saturation ratio S are necessary for quantitative interpretations of experimental data obtained from the expansion cloud chamber. In this paper, we revisit the thermodynamics associated with the underlying assumptions for calculating the time-dependent temperature T(t) and saturation ratio S(t) in an expansion chamber as a function of experimentally observable parameters. We introduce an intuitive and robust method, the virtual path (VP) method, by which changes in the thermodynamic state of a moist air parcel containing cloud droplets are schematically represented on a thermodynamic diagram. The validity of the VP method is confirmed by comparisons with the differential equation (DE) method, which is a numerical simulation of real physical processes according to the time evolution equations involving T and S. In contrast to the conventional DE method, the governing equations of the VP method do not involve time t, an irrelevant parameter in the framework of classical thermodynamics. The VP method is advantageous compared to the DE method because the former is applicable to the raw experimental data acquired with a finite time resolution, allowing a robust calculation of the T and S values and the errors that are only caused by the measurement errors of the input data.

  17. Pore Water Pressure Response of a Soil Subjected to Traffic Loading under Saturated and Unsaturated Conditions

    NASA Astrophysics Data System (ADS)

    Cary, Carlos

    This study presents the results of one of the first attempts to characterize the pore water pressure response of soils subjected to traffic loading under saturated and unsaturated conditions. It is widely known that pore water pressure develops within the soil pores as a response to external stimulus. Also, it has been recognized that the development of pores water pressure contributes to the degradation of the resilient modulus of unbound materials. In the last decades several efforts have been directed to model the effect of air and water pore pressures upon resilient modulus. However, none of them consider dynamic variations in pressures but rather are based on equilibrium values corresponding to initial conditions. The measurement of this response is challenging especially in soils under unsaturated conditions. Models are needed not only to overcome testing limitations but also to understand the dynamic behavior of internal pore pressures that under critical conditions may even lead to failure. A testing program was conducted to characterize the pore water pressure response of a low plasticity fine clayey sand subjected to dynamic loading. The bulk stress, initial matric suction and dwelling time parameters were controlled and their effects were analyzed. The results were used to attempt models capable of predicting the accumulated excess pore pressure at any given time during the traffic loading and unloading phases. Important findings regarding the influence of the controlled variables challenge common beliefs. The accumulated excess pore water pressure was found to be higher for unsaturated soil specimens than for saturated soil specimens. The maximum pore water pressure always increased when the high bulk stress level was applied. Higher dwelling time was found to decelerate the accumulation of pore water pressure. In addition, it was found that the higher the dwelling time, the lower the maximum pore water pressure. It was concluded that upon further research, the proposed models may become a powerful tool not only to overcome testing limitations but also to enhance current design practices and to prevent soil failure due to excessive development of pore water pressure.

  18. Pore evolution during high pressure atomic vapor deposition D. D. Hass Y. Y. Yang H. N. G. Wadley

    E-print Network

    Wadley, Haydn

    Pore evolution during high pressure atomic vapor deposition D. D. Hass Æ Y. Y. Yang Æ H. N. G distribution (IAD) for vapor atom impacts with a substrate is strongly effected by the background pressure The development of physical vapor deposition systems that employ inert gas jets to entrain and deposit atomic

  19. Temperature and water vapor pressure effects on the friction coefficient of hydrogenated diamondlike carbon films.

    SciTech Connect

    Dickrell, P. L.; Sawyer, W. G.; Eryilmaz, O. L.; Erdemir, A.; Energy Technology; Univ. of Florida

    2009-07-01

    Microtribological measurements of a hydrogenated diamondlike carbon film in controlled gaseous environments show that water vapor plays a significant role in the friction coefficient. These experiments reveal an initial high friction transient behavior that does not reoccur even after extended periods of exposure to low partial pressures of H{sub 2}O and O{sub 2}. Experiments varying both water vapor pressure and sample temperature show trends of a decreasing friction coefficient as a function of both the decreasing water vapor pressure and the increasing substrate temperature. Theses trends are examined with regard to first order gas-surface interactions. Model fits give activation energies on the order of 40 kJ/mol, which is consistent with water vapor desorption.

  20. Integrated Rig for the Production of Boron Nitride Nanotubes via the Pressurized Vapor-Condenser Method

    NASA Technical Reports Server (NTRS)

    Smith, Michael W. (Inventor); Jordan, Kevin C. (Inventor)

    2014-01-01

    An integrated production apparatus for production of boron nitride nanotubes via the pressure vapor-condenser method. The apparatus comprises: a pressurized reaction chamber containing a continuously fed boron containing target having a boron target tip, a source of pressurized nitrogen and a moving belt condenser apparatus; a hutch chamber proximate the pressurized reaction chamber containing a target feed system and a laser beam and optics.

  1. Integrated rig for the production of boron nitride nanotubes via the pressurized vapor-condenser method

    SciTech Connect

    Smith, Michael W; Jordan, Kevin C

    2014-03-25

    An integrated production apparatus for production of boron nitride nanotubes via the pressure vapor-condenser method. The apparatus comprises: a pressurized reaction chamber containing a continuously fed boron containing target having a boron target tip, a source of pressurized nitrogen and a moving belt condenser apparatus; a hutch chamber proximate the pressurized reaction chamber containing a target feed system and a laser beam and optics.

  2. Gas chromatographic vapor pressure determination of atmospherically relevant oxidation products of ?-caryophyllene and ?-pinene

    NASA Astrophysics Data System (ADS)

    Hartonen, Kari; Parshintsev, Jevgeni; Vilja, Vesa-Pekka; Tiala, Heidi; Knuuti, Sinivuokko; Lai, Ching Kwan; Riekkola, Marja-Liisa

    2013-12-01

    Vapor pressures (subcooled liquid, pliquid) of atmospherically relevant oxidation products of ?-caryophyllene (?-caryophyllene aldehyde 0.18 ± 0.03 Pa and ?-nocaryophyllene aldehyde 0.17 ± 0.03 Pa), and ?-pinene (pinonaldehyde 16.8 ± 0.20 Pa, cis-pinic acid 0.12 ± 0.06 Pa, and cis-pinonic acid 0.99 ± 0.19 Pa) at 298 K were obtained by gas chromatography with flame ionization detection (FID) and mass spectrometric (MS) detection. The effects of stationary phase polarity and column film thickness on the vapor pressure values were investigated. Increase in stationary phase polarity provided smaller values, while increase in film thickness gave slightly higher values. Values for vapor pressure were at least two orders of magnitude lower when obtained by a method utilizing vaporization enthalpy (determined by gas chromatography-mass spectrometry) than by retention index method. Finally, the results were compared with values calculated by group contribution theory. For the ?-caryophyllene oxidation products, the values measured by gas chromatography were slightly lower than those obtained by theoretical calculations. The opposite trend was observed for the ?-pinene oxidation products. The methods based on gas chromatography are concluded to be highly useful for the determination of vapor pressures of semi-volatile compounds. Except for the most polar pinic and pinonic acids, differences between vapor pressure values obtained by GC-FID and GC-MS were small. Since GC-MS provides structural information simultaneously, the use of GC-MS is recommended.

  3. Feasibility of hydroxyl concentration measurements by laser-saturated fluorescence in high-pressure flames

    NASA Technical Reports Server (NTRS)

    Carter, Campbell D.; King, Galen B.; Laurendeau, Normand M.; Salmon, J. Thaddeus

    1987-01-01

    The effect of pressure on the laser-saturated fluorescence method for measuring OH concentration in high-pressure flames is studied using calculations for the burned-gas region of a stoichiometric H2-O2 flame at 2000 K. A numerical model of the excitation dynamics of OH is developed to explore the validity of the balanced cross-rate model at higher pressures. It is shown that depopulation of the laser-coupled levels is sensitive to collisions which depopulate v-double-prime (VDP) = 0 and to rate coefficients for rotational transfer in the ground state which are smaller than those in the excited state. In particular, it is shown that the depopulation of VDP = 0, and hence the laser-coupled levels, depends on the probability of electronic quenching to vibrational levels for which VDP is greater than 0 and vibrational relaxation to VDP = 0.

  4. The Dynamics of Vapor Bubbles in Acoustic Pressure Fields

    NASA Technical Reports Server (NTRS)

    Hao, Y.; Prosperetti, A.

    1999-01-01

    In spite of a superficial similarity with gas bubbles, the intimate coupling between dynamical and thermal processes confers to oscillating vapor bubbles some unique characteristics. This paper examines numerically the validity of some asymptotic-theory predictions such as the existence of two resonant radii and a limit size for a given sound amplitude and frequency. It is found that a small vapor bubble in a sound field of sufficient amplitude grows quickly through resonance and continues to grow thereafter at a very slow rate, seemingly indefinitely. Resonance phenomena therefore play a role for a few cycles at most, and reaching a limit size-if one exists at all-is found to require far more than several tens of thousands of cycles. It is also found that some small bubbles may grow or collapse depending on the phase of the sound field. The model accounts in detail for the thermo-fluid-mechanic processes in the vapor. In the second part of the paper, an approximate formulation valid for bubbles small with respect to the thermal penetration length in the vapor is derived and its accuracy examined, The present findings have implications for acoustically enhanced boiling heat transfer and other special applications such as boiling in microgravity.

  5. Fractional-calculus model for temperature and pressure waves in fluid-saturated porous rocks.

    PubMed

    Garra, Roberto

    2011-09-01

    We study a fractional time derivative generalization of a previous Natale-Salusti model about nonlinear temperature and pressure waves, propagating in fluid-saturated porous rocks. Their analytic solutions, i.e., solitary shock waves characterized by a sharp front, are here generalized, introducing a formalism that allows memory mechanisms. In realistic wave propagation in porous media we must take into account spatial or temporal variability of permeability, diffusivity, and other coefficients due to the system "history." Such a rock fracturing or fine particulate migration could affect the rock and its pores. We therefore take into account these phenomena by introducing a fractional time derivative to simulate a memory-conserving formalism. We also discuss this generalized model in relation to the theory of dynamic permeability and tortuosity in fluid-saturated porous media. In such a realistic model we obtain exact solutions of Burgers' equation with time fractional derivatives in the inviscid case. PMID:22060520

  6. Sulfide saturation of basalt and andesite melts at high pressures and temperatures

    NASA Technical Reports Server (NTRS)

    Wendlandt, R. F.

    1982-01-01

    When the sulfur content of an Fe-bearing magma exceeds the saturation limit for the bulk composition, an immiscible iron sulfide melt fraction separates. For an understanding of the geochemistry of sulfur-bearing magmatic systems, more information is needed regarding the solubility of metal sulfide in silicate melt at its source and the solubility changes as a function of changing intensive and extensive variables. In the present investigation, the sulfur saturation surface is determined for the pressure range from 12.5 to 30 kbar and the temperature range from 1300 to 1460 C for three silicate melt compositions representing a range of SiO2 and FeO compositions.

  7. Measurements of Capillary Pressure-Saturation Relationships for Silica Sands Using Light Transmission Visualization and a Rapid Pseudo Static Methods

    EPA Science Inventory

    Measurement of water saturation in porous media is essential for many types of studies including subsurface water flow, subsurface colloids transport and contaminant remediation to name a few. Water saturation (S) in porous media is dependent on the capillary pressure (Pc) which,...

  8. Assessment of the Accuracy of Pharmacy Students’ Compounded Solutions Using Vapor Pressure Osmometry

    PubMed Central

    McPherson, Timothy B.

    2013-01-01

    Objective. To assess the effectiveness of using a vapor pressure osmometer to measure the accuracy of pharmacy students’ compounding skills. Design. Students calculated the theoretical osmotic pressure (mmol/kg) of a solution as a pre-laboratory exercise, compared their calculations with actual values, and then attempted to determine the cause of any errors found. Assessment. After the introduction of the vapor pressure osmometer, the first-time pass rate for solution compounding has varied from 85% to 100%. Approximately 85% of students surveyed reported that the instrument was valuable as a teaching tool because it objectively assessed their work and provided immediate formative assessment. Conclusions. This simple technique of measuring compounding accuracy using a vapor pressure osmometer allowed students to see the importance of quality control and assessment in practice for both pharmacists and technicians. PMID:23610476

  9. A modeling approach to represent hysteresis in capillary pressure-saturation relationship based on fluid connectivity in void space

    E-print Network

    Zhou, Quanlin

    A modeling approach to represent hysteresis in capillary pressure- saturation relationship based of hysteresis behavior and capillary entrapment of wetting and nonwetting fluids. The hysteretic constitutive measurements of primary drainage and main wetting curves. The hysteresis model results are verified

  10. Melting Processes at the Base of the Mantle Wedge: Melt Compositions and Melting Reactions for the First Melts of Vapor-Saturated Lherzolite

    NASA Astrophysics Data System (ADS)

    Grove, T. L.; Till, C. B.

    2014-12-01

    Vapor-saturated melting experiments have been performed at pressures near the base of the mantle wedge (3.2 GPa). The starting composition is a metasomatized lherzolite containing 3 wt. % H2O. Near-solidus melts and coexisting mineral phases have been characterized in experiments that span 925 to 1100 oC with melt % varying from 6 to 9 wt. %. Olivine, orthopyroxene, clinopyroxene and garnet coexist with melt over the entire interval and rutile is also present at < 1000 oC. Melt is andesitic in composition and varies from 60 wt. % SiO2 at 950 oC to 52 wt. % at 1075 oC. The Al2O3 contents of the melt are 13 to 14 wt. %, and CaO contents range from 1 and 4 wt. %. Melting is peritectic with orthopyroxene + liquid produced by melting of garnet + olivine + high-Ca pyroxene. In addition to quenched melt, we observe a quenched silicate component that is rhyolitic (>72 % SiO2) that we interpret as a precipitate from the coexisting supercritical H2O-rich vapor. Extrapolation of the measured compositional variation toward the solidus suggests that the first melt may be very SiO2 rich (i.e., granitic). We suggest that these granitic melts are the first melts of the mantle near the slab-wedge interface. As these SiO2-rich melts ascend into shallower, hotter overlying mantle, they continue to interact with the surrounding mantle and evolve in composition. These first melts may elucidate the geochemical and physical processes that accompany the beginnings of H2O flux melting.

  11. Effect of strain amplitude on relaxation spectra of attenuation in dry and saturated sandstone under pressure

    NASA Astrophysics Data System (ADS)

    Mashinskii, E. I.

    2007-06-01

    Laboratory experiments have been carried out to investigate the amplitude-frequency dependence of compressional- and shear-wave attenuation in samples of dry and saturated sandstone. The measurements were performed using the reflection method on a pulse frequency of 1 MHz in the strain range ~(0.3-2.0) × 10-6 under a confining pressure of 20 MPa. In general, the attenuation decreases monotonically with increasing strain amplitude as Q^{-1} \\propto \\varepsilon ^{-n_{\\sim} }, where n~ = 0.003-0.045. The decrease in P-wave attenuation, Q-1p, for dry sandstone is 5%, but for saturated sandstone there is no change. The analogous decrease for Q-1s in the dry and the saturated sandstone is 8% and 4%, respectively. The P-wave relaxation spectra, Q-1p(f), in the dry and saturated sandstone are slightly different from each other but the S-wave relaxation spectra, Q-1s(f), are very different. The amplitude variation causes the change in the value of the relaxation strength ? that leads to the displacement of the curve Q-1(f) in the Y-direction. The value of ?s in the saturated rock is four times more than the value ?p in the dry rock, and the curves Q-1s(f) are shifted relative to Q-1p(f) towards higher frequencies. The upward-downward amplitude dependence ?p(?1-6-1) both in the dry and the saturated rock is represented by the descending curve. The ?s(?1-6-1) curve for the saturated rock shows hysteresis, but for the dry rock hysteresis is absent. The increase in the strain amplitude gives rise to a small change in peak frequency, but stimulates considerable (up to 40%) decrease in the S-wave relaxation peak width. The unusual behaviour of attenuation is explained by a feature of the joint action of viscoelastic and microplastic mechanisms. These results can be used to improve methods of geological interpretation of acoustical and seismic data.

  12. Pore pressure diffusion and the hydrologic response of nearly saturated, thin landslide deposits of rainfall

    SciTech Connect

    Haneberg, W.C. )

    1991-11-01

    Previous workers have correlated slope failures during rainstorms with rainfall intensity, rainfall duration, and seasonal antecedent rainfall. This note shows how such relationships can be interpreted using a periodic steady-state solution to the well-known linear pressure diffusion equation. Normalization of the governing equation yields a characteristic response time that is a function of soil thickness, saturated hydraulic conductivity, and pre-storm effective porosity, and which is analogous to the travel time of a piston wetting front. The effects of storm frequency and magnitude are also successfully quantified using dimensionless attenuation factors and lag times.

  13. 40 CFR 63.7944 - How do I determine the maximum HAP vapor pressure of my remediation material?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... pressure of the remediation material: (i) Method 25E in 40 CFR part 60 appendix A; (ii) Methods described... vapor pressure of my remediation material? 63.7944 Section 63.7944 Protection of Environment... Pollutants: Site Remediation Performance Tests § 63.7944 How do I determine the maximum HAP vapor pressure...

  14. 40 CFR 63.7944 - How do I determine the maximum HAP vapor pressure of my remediation material?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... pressure of the remediation material: (i) Method 25E in 40 CFR part 60 appendix A; (ii) Methods described... vapor pressure of my remediation material? 63.7944 Section 63.7944 Protection of Environment... Pollutants: Site Remediation Performance Tests § 63.7944 How do I determine the maximum HAP vapor pressure...

  15. 40 CFR 63.7944 - How do I determine the maximum HAP vapor pressure of my remediation material?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... pressure of the remediation material: (i) Method 25E in 40 CFR part 60 appendix A; (ii) Methods described... vapor pressure of my remediation material? 63.7944 Section 63.7944 Protection of Environment... Pollutants: Site Remediation Performance Tests § 63.7944 How do I determine the maximum HAP vapor pressure...

  16. 40 CFR 63.7944 - How do I determine the maximum HAP vapor pressure of my remediation material?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... pressure of the remediation material: (i) Method 25E in 40 CFR part 60 appendix A; (ii) Methods described... vapor pressure of my remediation material? 63.7944 Section 63.7944 Protection of Environment... Pollutants: Site Remediation Performance Tests § 63.7944 How do I determine the maximum HAP vapor pressure...

  17. Surface passivation of c-Si by atmospheric pressure chemical vapor deposition of Al2O3

    E-print Network

    Surface passivation of c-Si by atmospheric pressure chemical vapor deposition of Al2O3 Lachlan E April 2012; published online 16 May 2012) Atmospheric pressure chemical vapor deposition of Al2O3://apl.aip.org/features/most_downloaded Information for Authors: http://apl.aip.org/authors #12;Surface passivation of c-Si by atmospheric pressure

  18. 40 CFR 63.7944 - How do I determine the maximum HAP vapor pressure of my remediation material?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... pressure of the remediation material: (i) Method 25E in 40 CFR part 60 appendix A; (ii) Methods described... vapor pressure of my remediation material? 63.7944 Section 63.7944 Protection of Environment... Pollutants: Site Remediation Performance Tests § 63.7944 How do I determine the maximum HAP vapor pressure...

  19. Saturation meter

    DOEpatents

    Gregurech, S.

    1984-08-01

    A saturation meter for use in a pressurized water reactor plant comprising a differential pressure transducer having a first and second pressure sensing means and an alarm. The alarm is connected to the transducer and is preset to activate at a level of saturation prior to the formation of a steam void in the reactor vessel.

  20. Pressure-coupled vaporization and combustion responses of liquid-fuel droplets in high-pressure environments

    NASA Technical Reports Server (NTRS)

    Yang, Vigor; Shuen, J. S.; Hsiao, C. C.

    1991-01-01

    The dynamic responses of liquid-fuel droplet vaporization and combustion to ambient pressure oscillations are examined. The analysis is based on the complete sets of conservation equations for both gas and liquid phases, and accommodates detailed treatments of finite-rate chemical kinetics and variable properties. With a full account of thermodynamic phase equilibrium at the droplet surface, the model enables a systematic examination of the effects of ambient flow conditions on the droplet behavior. The responses of hydrocarbon fuel droplets in both sub- and super-critical environments are investigated. Results indicate that the droplet gasification and burning mechanisms depend greatly on the ambient pressure. In particular, a rapid enlargement of the vaporization and combustion responses occurs when the droplet surface reaches its critical point, mainly due to the strong variations of latent heat of vaporization and thermophysical properties at the critical state.

  1. A simple grand canonical approach to compute the vapor pressure of bulk and finite size systems

    SciTech Connect

    Factorovich, Matías H.; Scherlis, Damián A.

    2014-02-14

    In this article we introduce a simple grand canonical screening (GCS) approach to accurately compute vapor pressures from molecular dynamics or Monte Carlo simulations. This procedure entails a screening of chemical potentials using a conventional grand canonical scheme, and therefore it is straightforward to implement for any kind of interface. The scheme is validated against data obtained from Gibbs ensemble simulations for water and argon. Then, it is applied to obtain the vapor pressure of the coarse-grained mW water model, and it is shown that the computed value is in excellent accord with the one formally deduced using statistical thermodynamics arguments. Finally, this methodology is used to calculate the vapor pressure of a water nanodroplet of 94 molecules. Interestingly, the result is in perfect agreement with the one predicted by the Kelvin equation for a homogeneous droplet of that size.

  2. Preconcentrator with high volume chiller for high vapor pressure particle detection

    DOEpatents

    Linker, Kevin L

    2013-10-22

    Apparatus and method for collecting particles of both high and low vapor pressure target materials entrained in a large volume sample gas stream. Large volume active cooling provides a cold air supply which is mixed with the sample gas stream to reduce the vapor pressure of the particles. In embodiments, a chiller cools air from ambient conditions to 0-15.degree. C. with the volumetric flow rate of the cold air supply being at least equal to the volumetric flow rate of the sample gas stream. In further embodiments an adsorption media is heated in at least two stages, a first of which is below a threshold temperature at which decomposition products of the high vapor pressure particle are generated.

  3. Theoretical and experimental studies on freezing point depression and vapor pressure deficit as methods to measure osmotic pressure of aqueous polyethylene glycol and bovine serum albumin solutions.

    PubMed

    Kiyosawa, Keitaro

    2003-05-01

    For survival in adverse environments where there is drought, high salt concentration or low temperature, some plants seem to be able to synthesize biochemical compounds, including proteins, in response to changes in water activity or osmotic pressure. Measurement of the water activity or osmotic pressure of simple aqueous solutions has been based on freezing point depression or vapor pressure deficit. Measurement of the osmotic pressure of plants under water stress has been mainly based on vapor pressure deficit. However, differences have been noted for osmotic pressure values of aqueous polyethylene glycol (PEG) solutions measured by freezing point depression and vapor pressure deficit. For this paper, the physicochemical basis of freezing point depression and vapor pressure deficit were first examined theoretically and then, the osmotic pressure of aqueous ethylene glycol and of PEG solutions were measured by both freezing point depression and vapor pressure deficit in comparison with other aqueous solutions such as NaCl, KCl, CaCl(2), glucose, sucrose, raffinose, and bovine serum albumin (BSA) solutions. The results showed that: (1) freezing point depression and vapor pressure deficit share theoretically the same physicochemical basis; (2) theoretically, they are proportional to the molal concentration of the aqueous solutions to be measured; (3) in practice, the osmotic pressure levels of aqueous NaCl, KCl, CaCl(2), glucose, sucrose, and raffinose solutions increase in proportion to their molal concentrations and there is little inconsistency between those measured by freezing point depression and vapor pressure deficit; (4) the osmotic pressure levels of aqueous ethylene glycol and PEG solutions measured by freezing point depression differed from the values measured by vapor pressure deficit; (5) the osmotic pressure of aqueous BSA solution measured by freezing point depression differed slightly from that measured by vapor pressure deficit. PMID:12834836

  4. Scaling Capillary Pressure Head - Saturation Relationships for Saprolite: Correction for Uncertainty Introduced by Pressure Cell Measurements on Tall Columns

    NASA Astrophysics Data System (ADS)

    Perfect, E.; McKay, L.; Driese, S.; Dane, J.; Kammerer, G.

    2002-12-01

    Dense non-aqueous phase liquids (DNAPL's) are important contaminants at many hazardous waste disposal sites. Relatively little information is available on DNAPL behavior in heterogeneous porous media such as fractured saprolite. We measured air-water and FluorinertTM (a non-toxic DNAPL surrogate)-water capillary pressure head (hc)-saturation (S) relationships close to saturation on an 18-cm long by 10-cm diameter undisturbed column of fractured shale saprolite. As hc increased, the pore volume invaded increased gradually rather than stepwise, indicating a range of fracture sizes with no clear division between pores in the fine-grained matrix and the fracture network. Microscopic examination of the pore structure in thin-sections of the saprolite supported this interpretation of the data. A fractal model, equivalent to the empirical Brooks and Corey model with zero residual saturation, was used to parameterize the S(hc) curves. The best-fit parameters were 19.54 and 30.10 cm for the displacement pressure head (hd) and 2.971 and 2.956 for the mass fractal dimension (D), for the air-water and FluorinertTM-water curves respectively. Parameters corrected for the hydrostatic fluid distribution within the column were obtained using the approach of Liu and Dane (1995). The corresponding corrected parameters were 26.45 and 16.23 cm for hc, and 2.966 and 2.966 for D. The correction procedure had a large impact on the form of the FluorinertTM-water curve, and relatively little impact on the form of the air-water curve. The uncorrected and corrected parameters for the air-water curve were then used to predict the corrected FluorinertTM-water curve using Leverett's function. Both sets of parameters produced predicted curves that explained over 99% of the variation in the FluorinertTM-water curve, with the corrected parameters producing a slightly better 1:1 relationship than the uncorrected parameters. Our results indicate that measured S(hc) curves for DNAPL-water systems are sensitive to the hydrostatic fluid distribution within the column. Air intrusion experiments can be used, in conjunction with Leverett's function, to predict the entry of DNAPL's into water-saturated heterogeneous porous media, and the error introduced by not correcting these measurements is relatively small.

  5. VAPOR PRESSURE ISOTOPE EFFECTS IN THE MEASUREMENT OF ENVIRONMENTAL TRITIUM SAMPLES.

    SciTech Connect

    Kuhne, W.

    2012-12-03

    Standard procedures for the measurement of tritium in water samples often require distillation of an appropriate sample aliquot. This distillation process may result in a fractionation of tritiated water and regular light water due to the vapor pressure isotope effect, introducing either a bias or an additional contribution to the total tritium measurement uncertainty. The magnitude of the vapor pressure isotope effect is characterized as functions of the amount of water distilled from the sample aliquot and the heat settings for the distillation process. The tritium concentration in the distillate is higher than the tritium concentration in the sample early in the distillation process, it then sharply decreases due to the vapor pressure isotope effect and becomes lower than the tritium concentration in the sample, until the high tritium concentration retained in the boiling flask is evaporated at the end of the process. At that time, the tritium concentration in the distillate again overestimates the sample tritium concentration. The vapor pressure isotope effect is more pronounced the slower the evaporation and distillation process is conducted; a lower heat setting during the evaporation of the sample results in a larger bias in the tritium measurement. The experimental setup used and the fact that the current study allowed for an investigation of the relative change in vapor pressure isotope effect in the course of the distillation process distinguish it from and extend previously published measurements. The separation factor as a quantitative measure of the vapor pressure isotope effect is found to assume values of 1.034 {+-} 0.033, 1.052 {+-} 0.025, and 1.066 {+-} 0.037, depending on the vigor of the boiling process during distillation of the sample. A lower heat setting in the experimental setup, and therefore a less vigorous boiling process, results in a larger value for the separation factor. For a tritium measurement in water samples, this implies that the tritium concentration could be underestimated by 3 - 6%.

  6. Communication: Dynamical and structural analyses of solid hydrogen under vapor pressure.

    PubMed

    Hyeon-Deuk, Kim; Ando, Koji

    2015-11-01

    Nuclear quantum effects play a dominant role in determining the phase diagram of H2. With a recently developed quantum molecular dynamics simulation method, we examine dynamical and structural characters of solid H2 under vapor pressure, demonstrating the difference from liquid and high-pressure solid H2. While stable hexagonal close-packed lattice structures are reproduced with reasonable lattice phonon frequencies, the most stable adjacent configuration exhibits a zigzag structure, in contrast with the T-shape liquid configuration. The periodic angular distributions of H2 molecules indicate that molecules are not a completely free rotor in the vapor-pressure solid reflecting asymmetric potentials from surrounding molecules on adjacent lattice sites. Discrete jumps of librational and H-H vibrational frequencies as well as H-H bond length caused by structural rearrangements under vapor pressure effectively discriminate the liquid and solid phases. The obtained dynamical and structural information of the vapor-pressure H2 solid will be useful in monitoring thermodynamic states of condensed hydrogens. PMID:26547150

  7. Communication: Dynamical and structural analyses of solid hydrogen under vapor pressure

    NASA Astrophysics Data System (ADS)

    Hyeon-Deuk, Kim; Ando, Koji

    2015-11-01

    Nuclear quantum effects play a dominant role in determining the phase diagram of H2. With a recently developed quantum molecular dynamics simulation method, we examine dynamical and structural characters of solid H2 under vapor pressure, demonstrating the difference from liquid and high-pressure solid H2. While stable hexagonal close-packed lattice structures are reproduced with reasonable lattice phonon frequencies, the most stable adjacent configuration exhibits a zigzag structure, in contrast with the T-shape liquid configuration. The periodic angular distributions of H2 molecules indicate that molecules are not a completely free rotor in the vapor-pressure solid reflecting asymmetric potentials from surrounding molecules on adjacent lattice sites. Discrete jumps of librational and H-H vibrational frequencies as well as H-H bond length caused by structural rearrangements under vapor pressure effectively discriminate the liquid and solid phases. The obtained dynamical and structural information of the vapor-pressure H2 solid will be useful in monitoring thermodynamic states of condensed hydrogens.

  8. Optimal oxygen pressure and time for reduced bubble formation in the N2-saturated decompressed prawn.

    PubMed

    Ertracht, O; Arieli, R; Arieli, Y; Ron, R; Erlichman, Z; Adir, Y

    2005-04-01

    Bubbles that grow during decompression are believed to originate from preexisting gas micronuclei. We showed that pretreatment of prawns with 203 kPa oxygen before nitrogen loading reduced the number of bubbles that evolved on decompression, presumably owing to the alteration or elimination of gas micronuclei (Arieli Y, Arieli R, and Marx A. J Appl Physiol 92: 2596-2599, 2002). The present study examines the optimal pretreatment for this assumed crushing of gas micronuclei. Transparent prawns were subjected to various exposure times (0, 5, 10, 15, and 20 min) at an oxygen pressure of 203 kPa and to 5 min at different oxygen pressures (PO2 values of 101, 151, 203, 405, 608, and 810 kPa), before nitrogen loading at 203 kPa followed by explosive decompression. After the decompression, bubble density and total gas volume were measured with a light microscope equipped with a video camera. Five minutes at a PO2 of 405 kPa yielded maximal reduction of bubble density and total gas volume by 52 and 71%, respectively. It has been reported that 2-3 h of hyperbaric oxygen at bottom pressure was required to protect saturation divers decompressed on oxygen against decompression sickness. If there is a shorter pretreatment that is applicable to humans, this will be of great advantage in diving and escape from submarines. PMID:15579569

  9. Vapor-modulated heat pipe for improved temperature control

    NASA Technical Reports Server (NTRS)

    Edwards, D. K.; Eninger, J. E.; Ludeke, E. E.

    1978-01-01

    Dryout induced by vapor throttling makes control of equipment temperature less dependent on variations in sink environment. Mechanism controls flow of vapor in heat pipe by using valve in return path to build difference in pressure and also difference in saturation temperature of the vapor. In steady state, valve closes just enough to produce partial dryout that achieves required temperature drop.

  10. Vapor pressures and heats of vaporization of primary coal tars. Quarterly technical progress report, April 1, 1996--June 30, 1996

    SciTech Connect

    Suuberg, E.M.; Oja, V.; Lilly, W.D.

    1997-12-31

    As the world continues to deplete its petroleum reserves, then heavy crude oil, coal liquids, and other heavy fossil fuels may be required to meet the world energy needs. Heavy fossil fuels contain molecules that are large and more aromatic and that contain more heteroatoms than those found in liquid crude oil. There is also significant current interest in general area of coal pyrolysis, particularly with respect to comprehensive models of this complicated phenomenon. This interest derives from central role of pyrolysis in all thermally driven coal conversion processes - gasification, combustion, liquefaction, mild gasification, or thermal beneficiation. There remain several key data needs in these application areas. Among them is a need for a more reliable correlation for prediction of the vapor pressures of heavy, primary coal tars. Such information is important in design of all coal conversion processes, in which the volatility of tarry products is of major concern. This paper presents work on the vapor pressures of coal tars using the continuous knudsen effusion technique.

  11. Atmospheric pressure chemical vapor deposition of TiN from tetrakis(dimethylamido)titanium and ammonia

    E-print Network

    pressure chemical vapor deposition. Experiments were conducted in a belt furnace; static experiments, in particular, is used for tool coating, solar-control films, and micro- electronic applications. Optically are associated with this process: chlorine contamination, HCl by-products, and high sub- strate temperatures

  12. Vapor Pressures and Thermodynamics of Oxygen-Containing Polycyclic Aromatic Hydrocarbons Measured Using Knudsen Effusion

    PubMed Central

    Goldfarb, Jillian L.

    2013-01-01

    Polycyclic aromatic hydrocarbons (PAHs) and their oxygenated derivatives (OPAHs) are ubiquitous environmental pollutants resulting from the incomplete combustion of coal and fossil fuels. Their vapor pressures are key thermodynamic data essential for modeling fate and transport within the environment. The present study involved nine PAHs containing oxygen heteroatoms, including aldehyde, carboxyl and nitro groups, specifically: 2-nitrofluorene; 9-fluorenecarboxylic acid; 2-fluorenecarboxaldehyde; 2-anthracenecarboxylic acid; 9-anthracenecarboxylic acid; 9-anthraldehyde; 1-nitropyrene; 1-pyrenecarboxaldehyde and 1-bromo-2-naphthoic acid. The vapor pressures of these compounds, with molecular weights ranging from 194 to 251 grams per mole, were measured using the isothermal Knudsen effusion technique in the temperature range of 329 to 421. The corresponding enthalpies of sublimation, calculated via the Clausius-Clapeyron equation, are compared to parent, non-oxygenated PAH compound data to determine the effect of the addition of these oxygen-containing heteroatoms. As expected, the addition of –CHO,–COOH, and –NO2 groups onto these PAHs increases the enthalpy of sublimation and decreases the vapor pressure as compared to the parent PAH; the position of substitution also plays a significant role in determining the vapor pressure of these OPAHs. PMID:18220445

  13. Vapor pressure deficit effects on leaf area expansion and transportation of soybean subjected to soil drying

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Effects of leaf-to-air vapor pressure difference (VPD) and soil water deficit on transpiration rate (TR) of plants are well understood but their effects on plant leaf area expansion (PLAE) are less defined. Both PLAE and TR are unaffected by soil drying until the fraction transpirable soil water (FT...

  14. Quasi-static vapor pressure measurements on reactive systems in inert atmosphere box

    NASA Technical Reports Server (NTRS)

    Fischer, A. K.

    1968-01-01

    Apparatus makes vapor pressure measurements on air-sensitive systems in an inert atmosphere glove box. Once the apparatus is loaded with the sample and all connections made, all measuring operations may be performed outside the box. The apparatus is a single-tube adaptation of the double-tube quasi-static technique.

  15. Molar Mass and Second Virial Coefficient of Polyethylene Glycol by Vapor Pressure Osmometry

    ERIC Educational Resources Information Center

    Schwinefus, Jeffrey J.; Checkal, Caleb; Saksa, Brian; Baka, Nadia; Modi, Kalpit; Rivera, Carlos

    2015-01-01

    In this laboratory experiment, students determine the number-average molar masses and second virial coefficients of polyethylene glycol (PEG) polymers ranging in molar mass from 200 to 1500 g mol[superscript -1] using vapor pressure osmometry (VPO). Students assess VPO in relation to accurate molar mass calculations of PEG polymers. Additionally,…

  16. Non-invasive Positive Pressure Ventilation during Sleep at 3800m: relationship to Acute Mountain Sickness and sleeping oxyhemoglobin saturation

    PubMed Central

    Johnson, PL; Popa, DA; Prisk, GK; Sullivan, CE; Edwards, N

    2014-01-01

    Background and objectives Ascent to high altitude results in hypobaric hypoxia and some individuals will develop Acute Mountain Sickness, which has been shown to be associated with low oxyhemoglobin saturation during sleep. Previous research has shown that positive end-expiratory pressure by use of expiratory valves in a face mask while awake, results in a reduction in AMS symptoms and higher oxyhemoglobin saturation. We aimed to test whether pressure ventilation during sleep would prevent AMS by keeping oxyhaemoglobin higher during sleep. Methods We compared sleeping oxyhemoglobin saturation and the incidence and severity of Acute Mountain Sickness in seven subjects sleeping for two consecutive nights at 3800m above sea level using either non-invasive positive pressure ventilation that delivered positive inspiratory and expiratory airway pressure via a face mask, or sleeping without assisted ventilation. The presence and severity of Acute Mountain Sickness was assessed by administration of the Lake Louise questionnaire. Results We found significant increases in the mean and minimum sleeping oxyhemoglobin saturation and decreases in AMS symptoms in subjects who used positive pressure ventilation during sleep. Mean and minimum sleeping SaO2 was lower in subjects who developed AMS after the night spent without positive pressure ventilation. Conclusion The use of positive pressure ventilation during sleep at 3800m significantly increased the sleeping oxygen saturation; we suggest that the marked reduction in symptoms of AMS is due to this higher sleeping SaO2. We agree with the findings from previous studies that the development of AMS is associated with a lower sleeping oxygen saturation. PMID:20051046

  17. Transient-pressure analysis in geothermal steam reservoirs with an immobile vaporizing liquid phase

    USGS Publications Warehouse

    Moench, A.F.; Atkinson, P.G.

    1978-01-01

    A finite-difference model for the radial horizontal flow of steam through a porous medium is used to evaluate transient-pressure behavior in the presence of an immobile vaporizing or condensing liquid phase. Graphs of pressure drawdown and buildup in terms of dimensionless pressure and time are obtained for a well discharging steam at a constant mass flow rate for a specified time. The assumptions are made that the steam is in local thermal equilibrium with the reservoir rocks, that temperature changes are due only to phase change, and that effects of vapor-pressure lowering are negligible. Computations show that when a vaporizing liquid phase is present the pressure drawdown exhibits behavior similar to that observed in noncondensable gas reservoirs, but delayed in time. A theoretical analysis allows for the computation of this delay and demonstrates that it is independent of flow geometry. The response that occurs upon pressure buildup is markedly different from that in a noncondensable gas system. This result may provide a diagnostic tool for establishing the existence of phase-change phenomena within a reservoir. ?? 1979.

  18. Thermodynamic properties and vapor pressures of polar fluids from a four-parameter corresponding-states method

    SciTech Connect

    Wilding, W.V.; Johnson, J.K.; Rowley, R.L.

    1987-11-01

    A recently proposed extended Lee-Kesler corresponding-states method (ELK) for polar fluids which accurately predicts compressibility factors and departure functions is considered. Tables of polar deviation functions have been generated and values of the shape/size and polar parameters for 52 polar fluids have been calculated, allowing the method to be used for quick hand calculation in addition to the previous, more accurate, computer applications. Additionally, vapor pressures of 44 pure polar fluids were computed using the full version of the ELK and the equality of the Gibbs free energy criterion for phase equilibrium. An ELK vapor pressure correlation is proposed which is essentially numerically equivalent to, but computationally simpler than, the former method. Computed vapor pressures agree with experimental values as well or better than other vapor pressure equations designed exclusively for vapor pressure prediction of polar fluids.

  19. Intersubband absorption saturation in AlN-based waveguide with GaN/AlN multiple quantum wells grown by metalorganic vapor phase epitaxy

    NASA Astrophysics Data System (ADS)

    Sodabanlu, Hassanet; Yang, Jung-Seung; Tanemura, Takuo; Sugiyama, Masakazu; Shimogaki, Yukihiro; Nakano, Yoshiaki

    2011-10-01

    Intersubband absorption saturation at 1.57 ?m wavelength was observed in a 400-?m long Si3N4-rib AlN-based waveguide with GaN/AlN multiple quantum wells (MQWs) fabricated by metalorganic vapor phase epitaxy (MOVPE). The self-saturation measurement was employed using a 1.56-?m short pulse laser which has a temporal width of 0.4 ps (full-width at half-maximum) and a repetition rate of 63 MHz. An intersubband absorption saturation by 5 dB was achieved using a pulse energy of 115 pJ. We have demonstrated the capability of MOVPE-grown GaN/AlN MQWs for intersubband optical devices operated at communication wavelength.

  20. Advanced Computational Modeling of Vapor Deposition in a High-Pressure Reactor

    NASA Technical Reports Server (NTRS)

    Cardelino, Beatriz H.; Moore, Craig E.; McCall, Sonya D.; Cardelino, Carlos A.; Dietz, Nikolaus; Bachmann, Klaus

    2004-01-01

    In search of novel approaches to produce new materials for electro-optic technologies, advances have been achieved in the development of computer models for vapor deposition reactors in space. Numerical simulations are invaluable tools for costly and difficult processes, such as those experiments designed for high pressures and microgravity conditions. Indium nitride is a candidate compound for high-speed laser and photo diodes for optical communication system, as well as for semiconductor lasers operating into the blue and ultraviolet regions. But InN and other nitride compounds exhibit large thermal decomposition at its optimum growth temperature. In addition, epitaxy at lower temperatures and subatmospheric pressures incorporates indium droplets into the InN films. However, surface stabilization data indicate that InN could be grown at 900 K in high nitrogen pressures, and microgravity could provide laminar flow conditions. Numerical models for chemical vapor deposition have been developed, coupling complex chemical kinetics with fluid dynamic properties.

  1. Advanced Computational Modeling of Vapor Deposition in a High-pressure Reactor

    NASA Technical Reports Server (NTRS)

    Cardelino, Beatriz H.; Moore, Craig E.; McCall, Sonya D.; Cardelino, Carlos A.; Dietz, Nikolaus; Bachmann, Klaus

    2004-01-01

    In search of novel approaches to produce new materials for electro-optic technologies, advances have been achieved in the development of computer models for vapor deposition reactors in space. Numerical simulations are invaluable tools for costly and difficult processes, such as those experiments designed for high pressures and microgravity conditions. Indium nitride is a candidate compound for high-speed laser and photo diodes for optical communication system, as well as for semiconductor lasers operating into the blue and ultraviolet regions. But InN and other nitride compounds exhibit large thermal decomposition at its optimum growth temperature. In addition, epitaxy at lower temperatures and subatmospheric pressures incorporates indium droplets into the InN films. However, surface stabilization data indicate that InN could be grown at 900 K in high nitrogen pressures, and microgravity could provide laminar flow conditions. Numerical models for chemical vapor deposition have been developed, coupling complex chemical kinetics with fluid dynamic properties.

  2. Investigations of dc electrical discharges in low-pressure sodium vapor with implications for AMTEC converters

    SciTech Connect

    Barkan, A.; Hunt, T.K.

    1998-07-01

    Upcoming designs for AMTEC modules capable of delivering as much as 150 watts will see the introduction of higher voltages into sodium vapor at pressures spanning a wide range. In theory, with any value for two out of three parameters: voltage, pressure, and electrode geometry, a value exists for the third parameter where DC electrical breakdown can occur; due to its low ionization energy, sodium vapor may be particularly susceptible to breakdown. This destructive event is not desirable in AMTEC modules, and sets a limit on the maximum voltage that can be built-up within any single enclosed module. An experimental cell was fabricated with representative electrode configurations and a separately heated sodium reservoir to test conditions typically expected during start-up, operation, and shutdown of AMTEC cells. Breakdown voltages were investigated in both sodium vapor and, for comparison, argon gas. The dependence on electrode material and polarity was also investigated. Additional information about leakage currents and the insulating properties of {alpha}-alumina in the presence of sodium vapor was collected, revealing a reversible tendency for conductive sodium films to build up under certain conditions, electrically shorting-out previously isolated components. In conclusion, safe operating limits on voltages, temperatures, and pressures are discussed.

  3. Pressure adaptation is linked to thermal adaptation in salt-saturated marine habitats.

    PubMed

    Alcaide, María; Stogios, Peter J; Lafraya, Álvaro; Tchigvintsev, Anatoli; Flick, Robert; Bargiela, Rafael; Chernikova, Tatyana N; Reva, Oleg N; Hai, Tran; Leggewie, Christian C; Katzke, Nadine; La Cono, Violetta; Matesanz, Ruth; Jebbar, Mohamed; Jaeger, Karl-Erich; Yakimov, Michail M; Yakunin, Alexander F; Golyshin, Peter N; Golyshina, Olga V; Savchenko, Alexei; Ferrer, Manuel

    2015-02-01

    The present study provides a deeper view of protein functionality as a function of temperature, salt and pressure in deep-sea habitats. A set of eight different enzymes from five distinct deep-sea (3040-4908?m depth), moderately warm (14.0-16.5°C) biotopes, characterized by a wide range of salinities (39-348 practical salinity units), were investigated for this purpose. An enzyme from a 'superficial' marine hydrothermal habitat (65°C) was isolated and characterized for comparative purposes. We report here the first experimental evidence suggesting that in salt-saturated deep-sea habitats, the adaptation to high pressure is linked to high thermal resistance (P value?=?0.0036). Salinity might therefore increase the temperature window for enzyme activity, and possibly microbial growth, in deep-sea habitats. As an example, Lake Medee, the largest hypersaline deep-sea anoxic lake of the Eastern Mediterranean Sea, where the water temperature is never higher than 16°C, was shown to contain halopiezophilic-like enzymes that are most active at 70°C and with denaturing temperatures of 71.4°C. The determination of the crystal structures of five proteins revealed unknown molecular mechanisms involved in protein adaptation to poly-extremes as well as distinct active site architectures and substrate preferences relative to other structurally characterized enzymes. PMID:25330254

  4. On the dynamics of fuel vapor pressure buildup in voided liquid-metal fast breeder reactor cores during transient heating

    SciTech Connect

    Rao, P.B.; Singh, O.P.

    1986-11-01

    An extension of previous work, the study examines the implications of the approximation that the fuel vapor and liquid temperatures remain equal during the transient. Modified mathematical formulations for calculating the transient fuel vapor temperatures separately are provided as well as the results of calculations of the dynamics of fuel vapor pressure buildup during transient heating in voided liquid-metal fast breeder reactor cooling channels by dispensing with the above approximation. The results with and without the approximation are compared with each other. The study indicates that, although the fuel vapor temperatures lag the liquid-fuel temperatures, the fuel vapor pressure buildup is relatively less sensitive to this lag. The use of the above approximation results in an overprediction of the transient vapor pressure by <10%.

  5. The vapor pressures of supercooled NHO3/H2O solutions. [in polar stratospheric clouds

    NASA Technical Reports Server (NTRS)

    Hanson, David R.

    1990-01-01

    A procedure utilizing the Gibbs-Duhem relation is used to extrapolate vapor pressures of supercooled HNO3 mixtures to 190 K. Values of A and B from the equation logP = A - B/T are presented for solutions between 0.20 and 0.25 mole fraction HNO3. In the stratosphere, if sufficient HNO3 vapor is present because it has not come into equilibrium with the nitric acid trihydrate, supercooled nitric acid solutions could condense at temperatures up to 1.5 + or - 0.8 K above the ice point.

  6. Vapor fraction measurements in a steam-water duct at atmospheric pressure using neutron radiography

    SciTech Connect

    Glickstein, S.S.; Murphy, J.H.; Hammond, R.B.

    1994-11-11

    Real-time neutron radiography has been used to study the dynamic behavior of two-phase flow and measure vapor fractions in a steam-water duct at atmospheric pressure. This unique experimental technique offers one the opportunity to observe and record on videotape now Patterns and transient behavior of two-phase flow inside opaque containers without perturbing the environment. The neutron radiographic technique is non-intrusive and requires no special transparent window region. Data are recorded simultaneously over a large area of interest. Image processing of the video data can be employed to measure bubble velocities and time-averaged and Instantaneous vapor fractions.

  7. Measurements of blast waves from bursting frangible spheres pressurized with flash-evaporation vapor or liquid

    NASA Technical Reports Server (NTRS)

    Esparaza, E. D.; Baker, W. E.

    1977-01-01

    Incident overpressure data from frangible spheres pressurized with a flash-evaporating fluid in liquid and vapor form were obtained in laboratory experiments. Glass spheres under higher than ambient internal pressure of Freon-12 were purposely burst to obtain time histories of overpressure. Nondimensional peak pressures, arrival and duration times, and impulses are presented, and whenever possible plotted and compared with compiled data for Pentolite high-explosive. The data are generally quite repeatable and show differences from blast data produced by condensed high-explosives.

  8. The relationship between gas hydrate saturation and P-wave velocity of pressure cores obtained in the Eastern Nankai Trough

    NASA Astrophysics Data System (ADS)

    Konno, Y.; Yoneda, J.; Jin, Y.; Kida, M.; Suzuki, K.; Nakatsuka, Y.; Fujii, T.; Nagao, J.

    2014-12-01

    P-wave velocity is an important parameter to estimate gas hydrate saturation in sediments. In this study, the relationship between gas hydrate saturation and P-wave velocity have been analyzed using natural hydrate-bearing-sediments obtained in the Eastern Nankai Trough, Japan. The sediment samples were collected by the Hybrid Pressure Coring System developed by Japan Agency for Marine-Earth Science and Technology during June-July 2012, aboard the deep sea drilling vessel CHIKYU. P-wave velocity was measured on board by the Pressure Core Analysis and Transfer System developed by Geotek Ltd. The samples were maintained at a near in-situ pressure condition during coring and measurement. After the measurement, the samples were stored core storage chambers and transported to MHRC under pressure. The samples were manipulated and cut by the Pressure-core Non-destructive Analysis Tools or PNATs developed by MHRC. The cutting sections were determined on the basis of P-wave velocity and visual observations through an acrylic window equipped in the PNATs. The cut samples were depressurized to measure gas volume for saturation calculations. It was found that P-wave velocity correlates well with hydrate saturation and can be reproduced by the hydrate frame component model. Using pressure cores and pressure core analysis technology, nondestructive and near in-situ correlation between gas hydrate saturation and P-wave velocity can be obtained. This study was supported by funding from the Research Consortium for Methane Hydrate Resources in Japan (MH21 Research Consortium) planned by the Ministry of Economy, Trade and Industry (METI), Japan.

  9. Development of a Model for High Precursor Conversion Efficiency Pulsed-Pressure Chemical Vapor Deposition (PP-CVD) Processing

    E-print Network

    Hickman, Mark

    1 Development of a Model for High Precursor Conversion Efficiency Pulsed- Pressure Chemical Vapor. ___________________________________________________________________________ Abstract A model of the movement of precursor particles in the unsteady Pulsed-Pressure Chemical Vapour and moderate reactor peak pressure. Keywords: Pulsed pressure chemical vapour deposition (PP-CVD), Precursor

  10. On the theory of pressure and temperature nonlinear waves in compressible fluid-saturated porous rocks

    NASA Astrophysics Data System (ADS)

    Merlani, Antonio Luigi; Natale, Giuseppe; Salusti, Ettore

    Thermo-poro-elastic equations describing fluid migration through fluid-saturated porous media at depth in the crust are analyzed theoretically following recent formulations of Rice and Cleary (1976), McTigue (1986) and Bonafede (1991). In this study these ideas are applied to a rather general model, namely to a deep hot and pressurized reservoir of fluid, which suddenly enters into contact with an overlaying large colder fluid-saturated layer. In a one-dimensional idealization this system can be described by two nonlinear differential heat-like equations on the matrix-fluid temperature and on the fluid overpressure over the hydrostatic value. The nonlinear couplings are due to Darcy thermal advection and to the mechanical work rate. Here we first sketch nonlinear solutions corresponding to Burgers' "solitary shock waves", which have recently been found valid for rocks with very low fluid diffusivity. Subsequently other nonlinear transient waves are discussed, such as "thermal" and "compensated" waves, which are found to exist for every value of the parameters present in the equations involved. One interesting aspect of these mechanisms is that the resulting time-scales are particularly small. Moreover, in order to figure out the system time-evolution and the role played by the fluid diffusivity/thermal diffusivity ratio, a mechanical similitude is proposed, which we treat both analytically and numerically. Although for realistic systems these solutions are somewhat idealized, they allow one to gain fundamental insight into fluid migration mechanisms in volcanic areas and in fault regions under strong frictional heating. As already discussed by McTigue, the theory is also of interest in studying areas of nuclear waste disposal. Furthermore such a theoretical study allows one to investigate the site at depth at which such nonlinear waves are generated.

  11. Ex 6.1(a) The vapor pressure of dichloromethane at 24.1C is 400 Torr and its enthalpy of vaporization is 28.7 kJ mol-1

    E-print Network

    Findley, Gary L.

    Ex 6.1(a) The vapor pressure of dichloromethane at 24.1°C is 400 Torr and its enthalpy of vaporization is 28.7 kJ mol-1 . Estimate the temperature at which its vapor pressure is 500 Torr. Ex 6.3(a) The vapor pressure of a liquid in the temperature range 200 K to 260 K was found to fit the expression ln

  12. Low pressure MOCVD (metalorganic chemical vapor deposition) growth of InSb

    SciTech Connect

    Cunningham, B.T.; Schneider, R.P. Jr.; Biefeld, R.M.

    1990-01-01

    Low pressure (200 Torr) metalorganic chemical vapor deposition (MOCVD) of InSb has been examined through variation of the Column III (TMIn) and Column V (TMSb or TESb) precursor partial pressures. The use of lower growth pressure significantly enhanced the range of allowable Column III Column V partial pressures in which specular morphology InSb could be obtained without the formation of In droplets or Sb crystals. In addition, a 70% improvement in the average hole mobility was obtained, compared to InSb grown in the same reactor at atmospheric pressure. SIMS analysis revealed that Si at the substrate/epitaxial layer interface is an important impurity that may contribute to degradation of the mobility. Substitution of TESb for TMSb did not result in any improvement in the purity of the InSb. 6 refs.

  13. Observations on vapor pressure in SPR caverns : sources.

    SciTech Connect

    Munson, Darrell Eugene

    2010-05-01

    The oil of the Strategic Petroleum Reserve (SPR) represents a national response to any potential emergency or intentional restriction of crude oil supply to this country, and conforms to International Agreements to maintain such a reserve. As assurance this reserve oil will be available in a timely manner should a restriction in supply occur, the oil of the reserve must meet certain transportation criteria. The transportation criteria require that the oil does not evolve dangerous gas, either explosive or toxic, while in the process of transport to, or storage at, the destination facility. This requirement can be a challenge because the stored oil can acquire dissolved gases while in the SPR. There have been a series of reports analyzing in exceptional detail the reasons for the increases, or regains, in gas content; however, there remains some uncertainty in these explanations and an inability to predict why the regains occur. Where the regains are prohibitive and exceed the criteria, the oil must undergo degasification, where excess portions of the volatile gas are removed. There are only two known sources of gas regain, one is the salt dome formation itself which may contain gas inclusions from which gas can be released during oil processing or storage, and the second is increases of the gases release by the volatile components of the crude oil itself during storage, especially if the stored oil undergoes heating or is subject to biological generation processes. In this work, the earlier analyses are reexamined and significant alterations in conclusions are proposed. The alterations are based on how the fluid exchanges of brine and oil uptake gas released from domal salt during solutioning, and thereafter, during further exchanges of fluids. Transparency of the brine/oil interface and the transfer of gas across this interface remains an important unanswered question. The contribution from creep induced damage releasing gas from the salt surrounding the cavern is considered through computations using the Multimechanism Deformation Coupled Fracture (MDCF) model, suggesting a relative minor, but potentially significant, contribution to the regain process. Apparently, gains in gas content can be generated from the oil itself during storage because the salt dome has been heated by the geothermal gradient of the earth. The heated domal salt transfers heat to the oil stored in the caverns and thereby increases the gas released by the volatile components and raises the boiling point pressure of the oil. The process is essentially a variation on the fractionation of oil, where each of the discrete components of the oil have a discrete temperature range over which that component can be volatized and removed from the remaining components. The most volatile components are methane and ethane, the shortest chain hydrocarbons. Since this fractionation is a fundamental aspect of oil behavior, the volatile component can be removed by degassing, potentially prohibiting the evolution of gas at or below the temperature of the degas process. While this process is well understood, the ability to describe the results of degassing and subsequent regain is not. Trends are not well defined for original gas content, regain, and prescribed effects of degassing. As a result, prediction of cavern response is difficult. As a consequence of this current analysis, it is suggested that solutioning brine of the final fluid exchange of a just completed cavern, immediately prior to the first oil filling, should be analyzed for gas content using existing analysis techniques. This would add important information and clarification to the regain process. It is also proposed that the quantity of volatile components, such as methane, be determined before and after any degasification operation.

  14. Water-vapor pressure in nests of the San Miguel Island Song Sparrow

    USGS Publications Warehouse

    Kern, Michael D.; Sogge, Mark K.; van Riper, Charles, III

    1990-01-01

    The water-vapor pressure (PN) in nests of the San Miguel Island race of Song Sparrows (Melospiza melodia micronyx) averaged 16 torr, but varied considerable between nests and within individual nests during successive days of incubation. Large daily fluctuations occurred throughout the incubation period and did not parallel concurrent changes in ambien vapor pressure (P1). Daily rates of water loss from nest eggs (MH2O) averaged 28 mg day-1, but also varied considerable within and between nests and did not correlate with changes in P1. MH2O increased 6-33% after the third day of incubation. PN was significantly higher and MH2O significantly lower in nests located in sheltered gullies than in nests from a windswept slope. These data suggest that Song Sparrows do not regulate PN to achieve hatching success.

  15. Initial Measurement of the Vapor Pressures of Simple Refractory Materials: Cu and Fe

    NASA Technical Reports Server (NTRS)

    Nuth, Joseph A., III; Ferguson, Frank T.; Johnson, Natasha; Martinez, Daniel

    2003-01-01

    It has become increasingly clear over the past decade that high temperature processes played important roles in the Primitive Solar Nebula. Unfortunately, basic data, such as the vapor pressures of iron or SiO have not been measured over the appropriate temperature range (near T approximately equal to 2000K), but must be extrapolated from lower temperature measurements often made more than 50 years ago. The extrapolation of the available data to higher temperatures can be quite complex and can depend on other factors such as the oxygen fugacity or the presence of hydrogen gas. Moreover, modern technology has made possible more accurate measurements of such quantities over a wider temperature range. We recently acquired a commercial Thermo-Cahn Thermogravimetric system capable of vacuum operation to 1700 C and measurement of mass change with microgram accuracy in a 100g sample or smaller. In this paper, we will report our progress in learning to make vapor pressure measurements using this system.

  16. Spectral properties of molecular iodine absorption cells filled to saturation pressure

    NASA Astrophysics Data System (ADS)

    Hrabina, Jan; Sarbort, Martin; Cip, Ondrej; Lazar, Josef

    2014-05-01

    The absorption cells - optical frequencies references - represent the crucial part of setups for practical realization of the meter unit - highly stable laser standards, where varied laser sources are frequency locked to the selected absorption transitions. Furthermore, not only in the most precise laboratory instruments, but also in less demanding interferometric measuring setups the frequency stabilization of the lasers throught the absorption in suitable media ensure the direct traceability to the fundamental standard of length. We present the results of measurement and evaluation of spectral properties of molecular iodine absorption cells filled to saturation pressure of absorption media. A set of cells filled with different amounts of molecular iodine was prepared and an agreement between expected and resulting spectral properties of these cells was observed and evaluated. The cells made of borosilicate glass instead of common fused silica were tested for their spectral properties in greater detail with special care for the absorption media purity - the measured hyperfine transitions linewidths were compared to cells traditionally made of fused silica glass with well known iodine purity. The usage of borosilicate glass material represents easier manufacturing process and also significant costs reduction but a great care must be taken to control/avoid the risk of absorption media contamination. An approach relying on measurement of linewidth of the hyperfine transitions is proposed and discussed.

  17. Some possible filler alloys with low vapor pressures for refractory-metal brazing

    NASA Technical Reports Server (NTRS)

    Morris, J. F.

    1973-01-01

    A compilation of eutectics and melting-point minima for binary combinations of metals having vapor pressures below 10 to the minus 10th power torr at 1500 degrees K and .00005 torr at 2000 degree K is presented. These compositions and others near them on their phase diagrams are potential special brazing fillers for refractory metals. Some possible problems and advantages for fusion bonds of such mixtures are indicated. Evaluations of brazing fillers containing refractory metals are reported.

  18. Methods of Measuring Vapor Pressures of Lubricants With Their Additives Using TGA and/or Microbalances

    NASA Technical Reports Server (NTRS)

    Scialdone, John J.; Miller, Michael K.; Montoya, Alex F.

    1996-01-01

    The life of a space system may be critically dependent on the lubrication of some of its moving parts. The vapor pressure, the quantity of the available lubricant, the temperature and the exhaust venting conductance passage are important considerations in the selection and application of a lubricant. In addition, the oil additives employed to provide certain properties of low friction, surface tension, antioxidant and load bearing characteristics, are also very important and need to be known with regard to their amounts and vapor pressures. This paper reports on the measurements and analyses carried out to obtain those parameters for two often employed lubricants, the Apiezon(TM)-C and the Krytox(TM) AB. The measurements were made employing an electronic microbalance and a thermogravimetric analyzer (TGA) modified to operate in a vacuum. The results have been compared to other data on these oils when available. The identification of the mass fractions of the additives in the oil and their vapor pressures as a function of the temperature were carried out. These may be used to estimate the lubricant life given its quantity and the system vent exhaust conductance. It was found that the Apiezon(TM)-C has three main components with different rates of evaporation while the Krytox(TM) did not indicate any measurable additive.

  19. Vapor Pressure and Evaporation Coefficient of Silicon Monoxide over a Mixture of Silicon and Silica

    NASA Technical Reports Server (NTRS)

    Ferguson, Frank T.; Nuth, Joseph A., III

    2012-01-01

    The evaporation coefficient and equilibrium vapor pressure of silicon monoxide over a mixture of silicon and vitreous silica have been studied over the temperature range (1433 to 1608) K. The evaporation coefficient for this temperature range was (0.007 plus or minus 0.002) and is approximately an order of magnitude lower than the evaporation coefficient over amorphous silicon monoxide powder and in general agreement with previous measurements of this quantity. The enthalpy of reaction at 298.15 K for this reaction was calculated via second and third law analyses as (355 plus or minus 25) kJ per mol and (363.6 plus or minus 4.1) kJ per mol respectively. In comparison with previous work with the evaporation of amorphous silicon monoxide powder as well as other experimental measurements of the vapor pressure of silicon monoxide gas over mixtures of silicon and silica, these systems all tend to give similar equilibrium vapor pressures when the evaporation coefficient is correctly taken into account. This provides further evidence that amorphous silicon monoxide is an intimate mixture of small domains of silicon and silica and not strictly a true compound.

  20. Pressure drop in fully developed, duct flow of dispersed liquid-vapor mixture at zero gravity

    NASA Technical Reports Server (NTRS)

    Sridhar, K. R.; Chao, B. T.; Soo, S. L.

    1990-01-01

    The dynamics of steady, fully developed dispersed liquid-vapor flow in a straight duct at 0-g is simulated by flowing water containing n-butyl benzoate droplets. Water and benzoate are immiscible and have identical density at room temperature. The theoretical basis of the simulation is given. Experiments showed that, for a fixed combined flow rate of water and benzoate, the frictional pressure drop is unaffected by large changes in the volume fraction of benzoate drops and their size distribution. Measured power spectra of the static wall pressure fluctuations induced by the turbulent water-benzoate flow also revealed that their dynamics is essentially unaltered by the presence of the droplets. These experimental findings, together with the theoretical analysis, led to the conclusion that the pressure drop in fully developed, dispersed liquid-vapor flow in straight ducts of constant cross section at 0-g is identical to that due to liquid flowing alone at the same total volumetric flow rate of the liquid-vapor mixture and, therefore, can be readily determined.

  1. In-Reactor Oxidation of Zircaloy-4 Under Low Water Vapor Pressures

    SciTech Connect

    Luscher, Walter G.; Senor, David J.; Clayton, Kevin; Longhurst, Glen

    2015-01-01

    Complementary in- and ex-reactor oxidation tests have been performed to evaluate the oxidation and hydrogen absorption performance of Zircaloy-4 (Zr-4) under relatively low partial pressures (300 and 1000 Pa) of water vapor at specified test temperatures (330° and 370°C). Data from these tests will be used to support fabrication of components intended for isotope-producing targets and provide information regarding the temperature and pressure dependence of oxidation and hydrogen absorption of Zr-4 over the specified range of test conditions. Comparisons between in- and ex- reactor test results were performed to evaluate the influence of irradiation.

  2. In-reactor oxidation of zircaloy-4 under low water vapor pressures

    SciTech Connect

    Luscher, Walter G.; Senor, David J.; Clayton, Kevin K.; Longhurst, Glen R.

    2015-01-01

    Complementary in- and ex-reactor oxidation tests have been performed to evaluate the oxidation and hydrogen absorption performance of Zircaloy-4 (Zr-4) under relatively low partial pressures (300 and 1000 Pa) of water vapor at specified test temperatures (330 and 370 ºC). Data from these tests will be used to support the fabrication of components intended for isotope-producing targets and provide information regarding the temperature and pressure dependence of oxidation and hydrogen absorption of Zr- 4 over the specified range of test conditions. Comparisons between in- and ex-reactor test results were performed to evaluate the influence of irradiation.

  3. Benzene under high pressure: A story of molecular crystals transforming to saturated networks, with a possible intermediate metallic phase

    SciTech Connect

    Wen, Xiao-Dong; Hoffmann, Roald; Ashcroft, N. W.

    2011-01-01

    In a theoretical study, benzene is compressed up to 300 GPa. The transformations found between molecular phases generally match the experimental findings in the moderate pressure regime (<20 GPa): phase I (Pbca) is found to be stable up to 4 GPa, while phase II (P43212) is preferred in a narrow pressure range of 4–7 GPa. Phase III (P21/c) is at lowest enthalpy at higher pressures. Above 50 GPa, phase V (P21 at 0 GPa; P21/c at high pressure) comes into play, slightly more stable than phase III in the range of 50–80 GP, but unstable to rearrangement to a saturated, four-coordinate (at C), one-dimensional polymer. Actually, throughout the entire pressure range, crystals of graphane possess lower enthalpy than molecular benzene structures; a simple thermochemical argument is given for why this is so. In several of the benzene phases there nevertheless are substantial barriers to rearranging the molecules to a saturated polymer, especially at low temperatures. Even at room temperature these barriers should allow one to study the effect of pressure on the metastable molecular phases. Molecular phase III (P21/c) is one such; it remains metastable to higher pressures up to ~200 GPa, at which point it too rearranges spontaneously to a saturated, tetracoordinate CH polymer. At 300 K the isomerization transition occurs at a lower pressure. Nevertheless, there may be a narrow region of pressure, between P = 180 and 200 GPa, where one could find a metallic, molecular benzene state. We explore several lower dimensional models for such a metallic benzene. We also probe the possible first steps in a localized, nucleated benzene polymerization by studying the dimerization of benzene molecules. Several new (C6H6)2 dimers are predicted.

  4. A comparison of strategies for imputing saturated pressure array data with application to the wheelchair-seating interface.

    PubMed

    Wininger, Michael; Crane, Barbara

    2014-09-01

    Abstract Purpose: The common responses to pressure sensor saturation are extreme: either discarding of data, or wholesale alteration of experimental protocol. Here, we test four simplistic strategies for restoring missing data due to sensor saturation, avoiding such drastic measures. Methods: We tested these algorithms on 62 pressure maps collected from 42 individuals (20 M/22 F, 54.1?±?26.2 years, 1.7?±?0.1?m, 71.9?±?17.8?kg) under a variety of seating conditions. These strategies were tested via a cross-validation design, censoring the maximum pressure value in the datasets and measuring prediction error. Results: The four strategies showed various prediction error rates: ??=?0.43?±?0.14 (simple substitution), ??=?0.16?±?0.21 (scaled substitution), ??=?0.19?±?0.21 (feature extraction), and ??=?0.24?±?0.32 (extrapolation by non-linear modeling). Conclusion: For single-sensor saturation, it may be possible to restore missing data using simple techniques. Implications for Rehabilitation We present a method for imputing missing data from pressure sensor arrays. The implications for rehabilitation are as follows. Improved flexibility in design of protocols concerning interfacial pressure measurement. Restoration of missing data from existing datasets. Reduction in recruitment burden for future studies. Reduction in exposure risk to study participants. PMID:25203501

  5. Status of the CNRS-LCSR program on high pressure droplet vaporization and burning

    NASA Technical Reports Server (NTRS)

    Chauveau, Christian; Goekalp, Iskender

    1993-01-01

    Depending on the surrounding flow and thermodynamic conditions, a single droplet may experience several gasification regimes, ranging from the envelope flame regime to pure vaporization. In practical situations, such as rocket propulsion or diesel combustion, the size distribution of droplets is, at best, bimodal, so that the possibility exists for the simultaneous presence of various regimes. For example, very small droplets are transported by the gas phase with zero relative velocity. This picture validates then the spherical symmetry hypothesis applied to the droplet and to the diffusion flame enveloping it. On the other hand, for larger droplets, a relative velocity exists due to drag forces. The most important influence of forced convection on droplet burning is the possibility to extinguish globally the envelope flame, or to establish a flame stabilized in the wake region. The burning rates of these regimes differ strongly. The characteristic time of droplet gasification is also influenced by the surrounding pressure and temperature. A parametric investigation of single droplet burning regimes is then helpful in providing the necessary physical ideas for sub-grid models used in spray combustion numerical prediction codes. The CNRS-LCSR experimental program on droplet vaporization and burning deals with these various regimes: stagnant and convective monocomponent droplet burning convective mono and bicomponent droplet vaporization; high temperature convective mono and biocomponent droplet vaporization; burning regimes of hydrazine and hydroxyl-ammonium-nitrate based monopropellant droplets and the vaporization regimes of liquid oxygen droplets. Studies on interacting droplets and on liquid aluminum droplets will start in the near future. The influence of high pressure is a common feature of all these studies. This paper summarizes the status of the CNRS-LCSR program on the effects of high pressure on monocomponent single droplet burning and vaporization, and some recent results obtained under normal and reduced gravity conditions with suspended droplets are presented. In the work described here, parabolic flights of an aircraft is used to create a reduced gravity environment of the order of 10(exp -2) g.

  6. Disjoining pressure and capillarity in the constrained vapor bubble heat transfer system.

    PubMed

    Chatterjee, Arya; Plawsky, Joel L; Wayner, Peter C

    2011-10-14

    Using the disjoining pressure concept in a seminal paper, Derjaguin, Nerpin and Churaev demonstrated that isothermal liquid flow in a very thin film on the walls of a capillary tube enhances the rate of evaporation of moisture by several times. The objective of this review is to present the evolution of the use of Churaev's seminal research in the development of the Constrained Vapor Bubble (CVB) heat transfer system. In this non-isothermal "wickless heat pipe", liquid and vapor flow results from gradients in the intermolecular force field, which depend on the disjoining pressure, capillarity and temperature. A Kelvin-Clapeyron model allowed the use of the disjoining pressure to be expanded to describe non-isothermal heat, mass and momentum transport processes. The intermolecular force field described by the convenient disjoining pressure model is the boundary condition for "suction" and stability at the leading edge of the evaporating curved flow field. As demonstrated by the non-isothermal results, applications that depend on the characteristics of the evaporating meniscus are legion. PMID:21470588

  7. Thermochemical and Vapor Pressure Behavior of Anthracene and Brominated Anthracene Mixtures.

    PubMed

    Fu, Jinxia; Suuberg, Eric M

    2013-03-25

    The present work concerns the thermochemical and vapor pressure behavior of the anthracene (1) + 2-bromoanthracene (2) and anthracene (1) + 9-bromoanthracene (3) systems. Solid-liquid equilibrium temperature and differential scanning calorimetry studies indicate the existence of a minimum melting solid state near an equilibrium temperature of 477.65 K at x 1 = 0.74 for the (1) + (2) system. Additionally, solid-vapor equilibrium studies for the (1) + (2) system show that the vapor pressure of the mixtures depends on composition, but does not follow ideal Raoult's law behaviour. The (1) + (3) system behaves differently from the (1) + (2) system. The (1) + (3) system has a solid solution like phase diagram. The system consists of two phases, an anthracene like phase and a 9-bromoanthracene like phase, while (1) + (2) mixtures only form a single phase. Moreover, experimental studies of the two systems suggest that the (1) + (2) system is in a thermodynamically lower energy state than the (1) + (3) system. PMID:24319314

  8. The Vapor Pressure of Environmentally Significant Organic Chemicals: A Review of Methods and Data at Ambient Temperature

    SciTech Connect

    Delle Site, A.

    1997-01-01

    The experimental techniques and the prediction procedures for the determination or evaluation of the vapor pressure of environmentally relevant organic compounds are described; with 259 references examined. For each of them the characteristics of precision and accuracy are given, when available from the literature. The experimental methods are classified as {open_quotes}direct{close_quotes} and {open_quotes}indirect.{close_quotes} The first class includes all those which can measure directly the vapor pressure, while the second concerns those which need {open_quotes}known{close_quotes} vapor pressures of reference compounds for the calibration. Prediction methods are based on the application of the Clapeyron{endash}Clausius equation or on the quantitative structure-property relationships. Also correlation methods require a suitable calibration. The vapor pressures at ambient temperature for several polycyclic aromatic hydrocarbons, polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and furans, selected pesticides, and some reference compounds are tabulated together with the vapor pressure equations and the enthalpy values in the temperature range of measurement. A critical comparison, based on a statistical analysis of the data obtained with different methods and derived from 152 references, is also carried out. {copyright} {ital 1996 American Institute of Physics and American Chemical Society.}{ital Key words:} chlorinated biphenyls; chlorinated dioxins; critically reviewed data; critically reviewed methods; pesticides; polynuclear aromatics; vapor pressure. {copyright} {ital 1996} {ital American Institute of Physics and American Chemical Society}

  9. Partial Pressures of In-Se from Optical Absorbance of the Vapor

    NASA Technical Reports Server (NTRS)

    Brebrick, R. F.; Su, Ching-Hua; Curreri, Peter A. (Technical Monitor)

    2001-01-01

    The optical absorbance of the vapor phase over various In-Se compositions between 33.3 and 61 atomic percent and 673 and 1418K has been measured and used to obtain the partial pressures of Se2(g) and In2Se(g). The results are in agreement with silica Bourdon gage measurements for compositions between 50 and 61 atomic percent but significantly higher than those from Knudsen cell and simultaneous Torsion-Knudsen cell measurements. The sequiselenide is found to sublime incongruently. Congruent vaporization occurs for the liquid above 1000 K between 50.08 and 56 at. percent Se. The Gibbs energy of formation of the liquid from its pure liquid elements between 1000 and 1300K is essentially independent of temperature and falls between -36 and -38 kJ per gram atomic weight for 50 and 56 percent Se at 1200 and 1300K.

  10. Vapor pressure isotope fractionation effects in planetary atmospheres: application to deuterium

    E-print Network

    Thierry Fouchet; Emmanuel Lellouch

    1999-11-15

    The impact of the vapor pressure difference between deuterated and nondeuterated condensing molecules in planetary atmospheres is quantitatively assessed. This difference results in a loss of deuterium in the vapor phase above the condensation level. In Titan, Uranus and Neptune, the effect on CH3D is too subtle to alter current D/H ratio determinations. In Mars, the effect can induce a large depletion of HDO, starting about one scale height above the condensation level. Although the current infrared measurements of the D/H ratio appear to be almost unaffected, the intensity of disk-averaged millimetric HDO lines can be modified by about 10%. The effect is much stronger in limb sounding, and can be easily detected from orbiter observations.

  11. Highly ionized physical vapor deposition plasma source working at very low pressure

    SciTech Connect

    Stranak, V.; Herrendorf, A.-P.; Drache, S.; Hippler, R.; Cada, M.; Hubicka, Z.; Tichy, M.

    2012-04-02

    Highly ionized discharge for physical vapor deposition at very low pressure is presented in the paper. The discharge is generated by electron cyclotron wave resonance (ECWR) which assists with ignition of high power impulse magnetron sputtering (HiPIMS) discharge. The magnetron gun (with Ti target) was built into the single-turn coil RF electrode of the ECWR facility. ECWR assistance provides pre-ionization effect which allows significant reduction of pressure during HiPIMS operation down to p = 0.05 Pa; this is nearly more than an order of magnitude lower than at typical pressure ranges of HiPIMS discharges. We can confirm that nearly all sputtered particles are ionized (only Ti{sup +} and Ti{sup ++} peaks are observed in the mass scan spectra). This corresponds well with high plasma density n{sub e} {approx} 10{sup 18} m{sup -3}, measured during the HiPIMS pulse.

  12. Characterization of Gas-Hydrate Sediment: In Situ Evaluation of Hydrate Saturation in Pores of Pressured Sedimental Samples

    NASA Astrophysics Data System (ADS)

    Jin, Y.; Konno, Y.; Kida, M.; Nagao, J.

    2014-12-01

    Hydrate saturation of gas-hydrate bearing sediment is a key of gas production from natural gas-hydrate reservoir. Developable natural gas-hydrates by conventional gas/oil production apparatus almost exist in unconsolidated sedimental layer. Generally, hydrate saturations of sedimental samples are directly estimated by volume of gas generated from dissociation of gas hydrates in pore spaces, porosity data and volume of the sediments. Furthermore, hydrate saturation can be also assessed using velocity of P-wave through sedimental samples. Nevertheless, hydrate saturation would be changed by morphological variations (grain-coating, cementing and pore-filling model) of gas hydrates in pore spaces. Jin et al.[1,2] recently observed the O-H stretching bands of H2O molecules of methane hydrate in porous media using an attenuated total reflection IR (ATR-IR) spectra. They observed in situ hydrate formation/dissociation process in sandy samples (Tohoku Keisya number 8, grain size of ca. 110 ?m). In this presentation, we present IR spectroscopy approach to in situ evaluation of hydrate saturation of pressured gas-hydrate sediments. This work was supported by funding from the Research Consortium for Methane Hydrate Resources in Japan (MH21 Research Consortium) planned by the Ministry of Economy, Trade and Industry (METI), Japan. [1] Jin, Y.; Konno, Y.; Nagao, J. Energy Fules, 2012, 26, 2242-2247. [2] Jin, Y.; Oyama, H.; Nagao, J. Jpn. J. Appl. Phys. 2009, 48, No. 108001.

  13. Surface roughening in low-pressure chemical vapor deposition Jason T. Drotar, Y.-P. Zhao, T.-M. Lu, and G.-C. Wang

    E-print Network

    Wang, Gwo-Ching

    Surface roughening in low-pressure chemical vapor deposition Jason T. Drotar, Y.-P. Zhao, T.-M. Lu etching, the pressure is usually low enough so that the mean free path of the vapor particles is much of a reemission model for chemical vapor deposition. We find that, for pure first-order reemission, the interface

  14. 42 CFR 84.163 - Man test for gases and vapors; Type C supplied-air respirators, demand and pressure-demand...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Man test for gases and vapors; Type C supplied-air respirators, demand and pressure-demand classes; test...Man test for gases and vapors; Type C supplied-air respirators, demand and pressure-demand classes; test...percent isoamyl acetate vapor, the intake of...

  15. 42 CFR 84.163 - Man test for gases and vapors; Type C supplied-air respirators, demand and pressure-demand...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Man test for gases and vapors; Type C supplied-air respirators, demand and pressure-demand classes; test...Man test for gases and vapors; Type C supplied-air respirators, demand and pressure-demand classes; test...percent isoamyl acetate vapor, the intake of...

  16. 42 CFR 84.163 - Man test for gases and vapors; Type C supplied-air respirators, demand and pressure-demand...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Man test for gases and vapors; Type C supplied-air respirators, demand and pressure-demand classes; test...Man test for gases and vapors; Type C supplied-air respirators, demand and pressure-demand classes; test...percent isoamyl acetate vapor, the intake of...

  17. 42 CFR 84.163 - Man test for gases and vapors; Type C supplied-air respirators, demand and pressure-demand...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Man test for gases and vapors; Type C supplied-air respirators, demand and pressure-demand classes; test...Man test for gases and vapors; Type C supplied-air respirators, demand and pressure-demand classes; test...percent isoamyl acetate vapor, the intake of...

  18. 42 CFR 84.163 - Man test for gases and vapors; Type C supplied-air respirators, demand and pressure-demand...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Man test for gases and vapors; Type C supplied-air respirators, demand and pressure-demand classes; test...Man test for gases and vapors; Type C supplied-air respirators, demand and pressure-demand classes; test...percent isoamyl acetate vapor, the intake of...

  19. Two-phase heat transfer and pressure drop of LNG during saturated flow boiling in a horizontal tube

    NASA Astrophysics Data System (ADS)

    Chen, Dongsheng; Shi, Yumei

    2013-12-01

    Two-phase heat transfer and pressure drop of LNG (liquefied natural gas) have been measured in a horizontal smooth tube with an inner diameter of 8 mm. The experiments were conducted at inlet pressures from 0.3 to 0.7 MPa with a heat flux of 8-36 kW m-2, and mass flux of 49.2-201.8 kg m-2 s-1. The effect of vapor quality, inlet pressure, heat flux and mass flux on the heat transfer characteristic are discussed. The comparisons of the experimental data with the predicted value by existing correlations are analyzed. Zou et al. (2010) correlation shows the best accuracy with 24.1% RMS deviation among them. Moreover four frictional pressure drop methods are also chosen to compare with the experimental database.

  20. Estimation of Fracture Toughness of Anisotropic Rocks by Semi-Circular Bend (SCB) Tests Under Water Vapor Pressure

    NASA Astrophysics Data System (ADS)

    Kataoka, M.; Obara, Y.; Kuruppu, M.

    2015-07-01

    In order to investigate the influence of water vapor pressure in the surrounding environment on mode I fracture toughness ( K Ic) of rocks, semi-circular bend (SCB) tests under various water vapor pressures were conducted. Water vapor is one of the most effective agents which promote stress corrosion of rocks. The range of water vapor pressure used was 10-2 to 103 Pa, and two anisotropic rock types, African granodiorite and Korean granite, were used in this work. The measurement of elastic wave velocity and observation of thin sections of these rocks were performed to investigate the microstructures of the rocks. It was found that the distribution of inherent microcracks and grains have a preferred orientation. Two types of specimens in different orientations, namely Type-1 and Type-3, were prepared based on the anisotropy identified by the differences in the elastic wave velocity. K Ic of both rock types was dependent on the water vapor pressure in the surrounding environment and decreased with increasing water vapor pressure. It was found that the degree of the dependence is influenced by the orientation and density of inherent microcracks. The experimental results also showed that K Ic depended on the material anisotropy. A fracture process was discussed on the basis of the geometry of fractures within fractured specimens visualized by the X-ray computed tomography (CT) method. It was concluded that the dominant factor causing the anisotropy of K Ic is the distribution of grains rather than inherent microcracks in these rocks.

  1. Low pressure metalorganic vapor phase epitaxy of InP in a vertical reactor

    SciTech Connect

    Oishi, M.; Kuroiwa, K.

    1985-05-01

    InP growth characteristics in low pressure metalorganic vapor phase epitaxy (MOVPE) in a vertical reactor were studied. A maximum mobility of 32,000 cmS/V s at 77 K was obtained. Selective epitaxy was also investigated, and completely selective epitaxy was realized for 15 m wide SiO2 masks at 40 torr. Preliminary results are shown for a hybrid LPE/MOVPE-grown distributed-feedback laser diode. Single longitudinal mode operation under pulsed current injection was achieved at room temperature.

  2. Vapor Pressure of Solid Polybrominated Diphenyl Ethers Determined via Knudsen Effusion Method

    PubMed Central

    Fu, Jinxia; Suuberg, Eric M.

    2013-01-01

    Polybrominated diphenyl ethers (PBDEs) are flame retardants used in a variety of consumer products. The solid vapor pressures of BDE15 and BDE209 were determined by use of the Knudsen effusion method, and the values measured extrapolated to 298.15 K are 3.12×10?3 and 9.02×10?13 Pa, respectively. The enthalpies of sublimation for these compounds have also been estimated by using the Clausius-Clapeyron equation and are 102.0 ± 3.5 and 157.1 ± 3.5 kJ/mol, respectively. Additionally, the melting points and enthalpies of fusion were measured by differential scanning calorimetry. PMID:21766320

  3. Torsion vapor pressures and standard sublimation enthalpies of cobalt and nickel di-iodides

    SciTech Connect

    Brunetti, B.; Piacente, V.; Scardala, P.

    1996-06-01

    The vapor pressures of CoI{sub 2} and NiI{sub 2} were measured by the torsion-effusion method. From second- and third-law treatments of the results, the standard sublimation enthalpies of both di-iodides were: {Delta}{sub m}H{sup o}(298) = 148 {+-} 1 and 158.0 {+-} 0.5 kJ/mol for CoI{sub 2} and NiI{sub 2}, respectively. From these values the corresponding enthalpies of formation were derived and compared with those reported in literature.

  4. The control of purity and stoichiometry of compound semiconductors by high vapor pressure transport

    NASA Technical Reports Server (NTRS)

    Bachmann, Klaus J.; Ito, Kazufumi; Scroggs, Jeffery S.; Tran, Hien T.

    1995-01-01

    In this report we summarize the results of a three year research program on high pressure vapor transport (HPVT) of compound semiconductors. Most of our work focused onto pnictides, in particular ZnGeP2, as a model system. Access to single crystals of well controlled composition of this material is desired for advancing the understanding and control of its point defect chemistry in the contest of remote, real-time sensing of trace impurities, e.g., greenhouse gases, in the atmosphere by ZnGeP2 optical parametric oscillators (OPO's).

  5. Solubility parameter and activity coefficient of HDEHP dimer in select organic diluents by vapor pressure osmometry

    SciTech Connect

    Gray, M.; Nilsson, M.; Zalupski, P.

    2013-07-01

    A thorough understanding of the non-ideal behavior of the chemical components utilized in solvent extraction contributes to the success of any large-scale spent nuclear fuel treatment. To address this, our current work uses vapor pressure osmometry to characterize the non-ideal behavior of the solvent extraction agent di-(2-ethylhexyl) phosphoric acid (HDEHP), a common extractant in proposed separation schemes. Solubility parameters were fit to data on HDEHP at four temperatures using models based on Scatchard Hildebrand regular solution theory with Flory Huggins entropic corrections. The results are comparable but not identical to the activity coefficients from prior slope analysis in the literature. (authors)

  6. Vapors and Droplets Mixture Deposition of Metallic Coatings by Very Low Pressure Plasma Spraying

    NASA Astrophysics Data System (ADS)

    Vautherin, B.; Planche, M.-P.; Bolot, R.; Quet, A.; Bianchi, L.; Montavon, G.

    2014-04-01

    In recent years, the very low pressure plasma-spraying (VLPPS) process has been intensely developed and implemented to manufacture thin, dense and finely structured ceramic coatings for various applications, such as Y2O3 for diffusion barriers, among other examples. This paper aims at presenting developments carried out on metallic coatings. Aluminum was chosen as a demonstrative material due to its "moderate" vaporization enthalpy (i.e., 38.23 KJ cm-3) compared to the one of copper (i.e., 55.33 KJ cm-3), cobalt (i.e., 75.03 KJ cm-3), or even tantalum (i.e., 87.18 KJ cm-3). The objective of this work is primarily to better understand the behavior of a solid precursor injected into the plasma jet leading to the formation of vapors and to better control the factors affecting the coating structure. Nearly dense aluminum coatings were successfully deposited by VLPPS at 100 Pa with an intermediate power plasma torch (i.e., Sulzer Metco F4 type gun with maximum power of 45 kW). Optical emission spectroscopy (OES) was implemented to study and analyze the vapor behavior into the plasma jet. Simplified CFD modeling allowed better understanding of some of the thermo-physical mechanisms. The effect of powder-size distribution, substrate temperature and spray distance were studied. The phase composition and microstructural features of the coatings were characterized by XRD and SEM. Moreover, Vickers microhardness measurements were implemented.

  7. 46 CFR 154.1836 - Vapor venting as a means of cargo tank pressure and temperature control.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... temperature control. 154.1836 Section 154.1836 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... LIQUEFIED GASES Operations § 154.1836 Vapor venting as a means of cargo tank pressure and temperature... cargo pressure and temperature control system under §§ 154.701 through 154.709 is operating and...

  8. 46 CFR 154.1836 - Vapor venting as a means of cargo tank pressure and temperature control.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... temperature control. 154.1836 Section 154.1836 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... LIQUEFIED GASES Operations § 154.1836 Vapor venting as a means of cargo tank pressure and temperature... cargo pressure and temperature control system under §§ 154.701 through 154.709 is operating and...

  9. 46 CFR 154.1836 - Vapor venting as a means of cargo tank pressure and temperature control.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... temperature control. 154.1836 Section 154.1836 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... LIQUEFIED GASES Operations § 154.1836 Vapor venting as a means of cargo tank pressure and temperature... cargo pressure and temperature control system under §§ 154.701 through 154.709 is operating and...

  10. 46 CFR 154.1836 - Vapor venting as a means of cargo tank pressure and temperature control.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... temperature control. 154.1836 Section 154.1836 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... LIQUEFIED GASES Operations § 154.1836 Vapor venting as a means of cargo tank pressure and temperature... cargo pressure and temperature control system under §§ 154.701 through 154.709 is operating and...

  11. 46 CFR 154.1836 - Vapor venting as a means of cargo tank pressure and temperature control.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... temperature control. 154.1836 Section 154.1836 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... LIQUEFIED GASES Operations § 154.1836 Vapor venting as a means of cargo tank pressure and temperature... cargo pressure and temperature control system under §§ 154.701 through 154.709 is operating and...

  12. Vapor pressures and heats of vaporization of primary coal tars. Quarterly technical progress report, 1 July 1993--30 September 1993

    SciTech Connect

    Suuberg, E.M.; Oja, V.; Lilly, W.D.

    1993-12-31

    There is significant current interest in general area of coal pyrolysis, particularly with respect to comprehensive models of this complicated phenomenon. This interest derives from the central role of pyrolysis in all thermally driven coal conversion processes -- gasification, combustion, liquefaction, mild gasification, or thermal benefication. There remain several key data needs in these application areas. Among them is a need for more reliable correlation for prediction of vapor pressure of heavy, primary coal tars. Such information is important in design of all coal conversion processes, in which the volatility of tarry products is of major concern. Only very limited correlations exist, and these are not considered reliable to even an order of magnitude when applied to tars. The present project seeks to address this important gap in the near term by direct measurement of vapor pressures of coal tar fractions, by application of well-established techniques and modifications thereof. The principal objectives of the program are to: (1) obtain data on the vapor pressures and heats of vaporization of tars from a range of ranks of coal, (2) develop correlations based on a minimum set of conveniently measurable characteristics of the tars, (3) develop equipment that would allow performing such measurements in a reliable, straightforward fashion. Results of the literature survey are compiled. The experimental tasks have been concerned with setup and calibration.

  13. Vapor pressures and heats of vaporization of primary coal tars. Quarterly technical progress report, 1 October 1993--31 December 1993

    SciTech Connect

    Suuberg, E.M.

    1993-12-31

    The vapor pressure correlations that exist at present for coal tars are very crude and they are not considered reliable to even an order of magnitude when applied to tars. Sophisticated general correlative approaches are slowly being developed, based upon group contribution methods, or based upon some key functional features of the molecules. These are as yet difficult to apply to coal tars. The detailed group contribution methods, in which fairly precise structural information is needed, do not lend themselves well for application to very complex, poorly characterized coal tars. The methods based upon more global types of characterizations have not yet dealt much with the question of oxygenated functional groups. In short, only very limited correlations exist, and these are not considered reliable to even an order of magnitude when applied to tars. The present project seeks to address this important gap in the near term by direct measurement of vapor pressures of coal tar fractions, by application of well-established techniques and modifications thereof. The principal objectives of the program are to: (1) obtain data on the vapor pressures and heats of vaporization of tars from a range of ranks of coal, (2) develop correlations based on a minimum set of conveniently measurable characteristics of the tars, (3) develop equipment that would allow performing such measurements in a reliable, straightforward fashion.

  14. Vapor pressure data for potassium carbonate-potassium bicarbonate solutions for application to multiuse power cycles

    NASA Astrophysics Data System (ADS)

    Hosler, E. R.; Ghandeharioun, S.

    A novel method of generating electric power based on a gas absorption cycle, rather than a normal Rankine steam power cycle, has been developed. This cycle uses carbon dioxide as the working fluid in the turbine and potassium carbonate solutions as the carrier fluid for the absorption part of the cycle. Thermodynamic calculations for typical operating parameters show a cycle efficiency of about 30 percent compared to a Carnot efficiency of about 40 percent and a Rankine cycle efficiency of about 20 percent for the same temperature limits. Thus, the cycle offers a significant thermal efficiency advantage compared to a Rankine cycle. Vapor pressure data have been obtained for various carrier solution concentrations in the high temperature, high pressure region where no previous data existed. This paper summarized these data. The data support the hypothesis that the gas absorption power cycle offers thermal efficiency benefits compared to a conventional steam power cycle.

  15. Pressure drop in fully developed, turbulent, liquid-vapor annular flows in zero gravity

    NASA Technical Reports Server (NTRS)

    Sridhar, K. R.; Chao, B. T.; Soo, S. L.

    1992-01-01

    The prediction of frictional pressure drop in fully developed, turbulent, annular liquid-vapor flows in zero gravity using simulation experiments conducted on earth is described. The scheme extends the authors' earlier work on dispersed flows. The simulation experiments used two immiscible liquids of identical density, namely, water and n-butyl benzoate. Because of the lack of rigorous analytical models for turbulent, annular flows, the proposed scheme resorts to existing semiempirical correlations. Results based on two different correlations are presented and compared. Others may be used. It was shown that, for both dispersed and annular flow regimes, the predicted frictional pressure gradients in 0-g are lower than those in 1-g under otherwise identical conditions. The physical basis for this finding is given.

  16. Oxy-Mat™ Mattress System Development Utilizing Simultaneous Measurement of Interface Pressure and Deep Tissue Oxygen Saturation.

    PubMed

    Butler, Glenn J; Kenyon, David J; Gorenstein, Scott; Davenport, Thomas; Golembe, Edward; Lee, Bok; Vieweg, Jacques

    2015-05-01

    The development and management of pressure ulcers (PUs) among hospital and nursing home patients is one of the greatest preventable challenges to healthcare worldwide. For over 50 years, pressure mapping and subjective comfort has been the primary indicators for mattress selection. Our research demonstrates that mattress/patient interface pressure and relative blood/oxygen perfusion do not inversely correlate and pressure is not a meaningful, real-time indicator of tissue ischemia and risk of pressure ulcer development. Developed in our research is a real-time sensor system to simultaneously measure and record these parameters over the anatomical sites at risk for PUs. Measurements focused on the heel, sacrum, trochanter, ischium, scapula and occipital. A modified pressure mapping system is used for interface pressure measurements and integrated with multiple near-infrared sensors to measure specific deep tissue hemoglobin saturated oxygen or rSO2. Testing and mattress design development was done during the period of 2008 to present. Over 200 human tests of commercially available mattresses were conducted in supine, 30 degree, and 70 degree positions, ranging in times of up to four hours. During this time period, we utilized 20 test subjects-eight female and 12 male-with ages ranging from 18 to 65 years. The result of this proprietary off-loading device evaluation and design system shows that the new Oxy-Mat™ (Off-Loading Technologies, Tarrytown, NY) Non-Powered Mattress System consistently provides optimized tissue perfusion as measured by natural deep tissue oxygen saturation levels. In extensive laboratory and clinical evaluations, the Oxy-Mat™ was shown to be functionally superior to CMS Group 2 powered mattresses. Another outcome of our research was that a powered mattress system may not be appropriate for most sensate and semi-ambulatory patients. Further research is underway. PMID:26054994

  17. Correction factors for saturation effects in white light and laser absorption spectroscopy for application to low pressure plasmas

    SciTech Connect

    Briefi, S.; Wimmer, C.; Fantz, U.

    2012-05-15

    In white light absorption spectroscopy, the broadening of the absorption signal due to the apparatus profile of the spectrometer may lead to an underestimation of the determined density as one measures an apparent optical depth. This is in particular true for high optical depth where saturation effects of the transmitted intensity occur. Provided that the line profile of the absorption line is known, the apparent optical depth effect can be accounted for by introducing a correction factor. The impact of the saturation and the approach of considering the effect are demonstrated for argon and indium lines in low pressure plasmas where correction factors of one order of magnitude or even higher are reached very easily. For the indium line, the hyperfine splitting has been taken into account. In laser absorption, the line profile is resolved. However, the weak but rather broad background emission of the laser diode can cause a saturation signal at the photo diode resulting also in an underestimation of the density obtained from the analysis. It is shown that this can be taken into account by fitting the theoretical line profile to the measured absorption signal which yields also a correction factor. The method is introduced and demonstrated at the example of the cesium resonance line including the hyperfine splitting. Typical correction factors around two are obtained for the cesium ground state density at conditions of a low pressure negative hydrogen ion source in which cesium is evaporated to enhance the negative ion production.

  18. Density, vapor pressure, solubility, and viscosity for water + lithium bromide + lithium nitrate + 1,3-propanediol

    SciTech Connect

    Park, Y.; Kim, J.S.; Lee, H.; Yu, S.I.

    1997-01-01

    Four physical properties (solubility, vapor pressure, density, and viscosity) of water + lithium bromide + lithium nitrate + 1,3-propanediol (LiBr/LiNO{sub 3} mole ratio = 4, (LiBr + LiNO{sub 3})/HO(CH{sub 2}){sub 3}OH mass ratio = 3.5) were measured. The system, a possible working fluid for an absorption heat pump, mainly consists of absorbent (LiBr + LiNO{sub 3} + HO(CH{sub 2}){sub 3}OH) and refrigerant (H{sub 2}O). Solubilities were measured by the visual polythermal method in the temperature range (285.55 to 346.65) K and in the absorbent concentration range (68.0 to 75.0) mass %. Vapor pressures were measured by the boiling point method in the temperature range (325.35 to 395.15) K and in the absorbent concentration range (46.0 to 69.6) mass %. Densities and viscosities were measured by a set of hydrometers and viscometers, respectively, in the temperature range (283.15 to 343.15) K and in the absorbent concentration range (24.3 to 70.3) mass %. The measured values were correlated.

  19. Fungicide volatilization measurements: inverse modeling, role of vapor pressure, and state of foliar residue.

    PubMed

    Bedos, Carole; Rousseau-Djabri, Marie-France; Loubet, Benjamin; Durand, Brigitte; Flura, Dominique; Briand, Olivier; Barriuso, Enrique

    2010-04-01

    Few data sets of pesticide volatilization from plants at the field scale are available. In this work, we report measurements of fenpropidin and chlorothalonil volatilization on a wheat field using the aerodynamic gradient (AG) method and an inverse dispersion modeling approach (using the FIDES model). Other data necessary to run volatilization models are also reported: measured application dose, crop interception, plant foliage residue, upwind concentrations, and meteorological conditions. The comparison of the AG and inverse modeling methods proved the latter to be reliable and hence suitable for estimating volatilization rates with minimized costs. Different diurnal/nocturnal volatilization patterns were observed: fenpropidin volatilization peaked on the application day and then decreased dramatically, while chlorothalonil volatilization remained fairly stable over a week-long period. Cumulated emissions after 31 h reached 3.5 g ha(-1) and 5 g ha(-1), respectively (0.8% and 0.6% of the theoretical application dose). A larger difference in volatilization rates was expected given differences in vapor pressure, and for fenpropidin, volatilization should have continued given that 80% of the initial amount remained on plant foliage for 6 days. We thus ask if vapor pressure alone can accurately estimate volatilization just after application and then question the state of foliar residue. We identified adsorption, formulation, and extraction techniques as relevant explanations. PMID:20199019

  20. PARAMETER ESTIMATION OF TWO-FLUID CAPILLARY PRESSURE-SATURATION AND PERMEABILITY FUNCTIONS

    EPA Science Inventory

    Capillary pressure and permeability functions are crucial to the quantitative description of subsurface flow and transport. Earlier work has demonstrated the feasibility of using the inverse parameter estimation approach in determining these functions if both capillary pressure ...

  1. A unified equation for calculating methane vapor pressures in the CH4-H2O system with measured Raman shifts

    USGS Publications Warehouse

    Lu, W.; Chou, I.-Ming; Burruss, R.C.; Song, Y.

    2007-01-01

    A unified equation has been derived by using all available data for calculating methane vapor pressures with measured Raman shifts of C-H symmetric stretching band (??1) in the vapor phase of sample fluids near room temperature. This equation eliminates discrepancies among the existing data sets and can be applied at any Raman laboratory. Raman shifts of C-H symmetric stretching band of methane in the vapor phase of CH4-H2O mixtures prepared in a high-pressure optical cell were also measured at temperatures between room temperature and 200 ??C, and pressures up to 37 MPa. The results show that the CH4 ??1 band position shifts to higher wavenumber as temperature increases. We also demonstrated that this Raman band shift is a simple function of methane vapor density, and, therefore, when combined with equation of state of methane, methane vapor pressures in the sample fluids at elevated temperatures can be calculated from measured Raman peak positions. This method can be applied to determine the pressure of CH4-bearing systems, such as methane-rich fluid inclusions from sedimentary basins or experimental fluids in hydrothermal diamond-anvil cell or other types of optical cell. ?? 2007 Elsevier Ltd. All rights reserved.

  2. Measurement of soil saturated hydraulic conductivity: The method of constant pressure tubes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field method to measure the saturated soil hydraulic conductivity is presented that does not require expensive equipment and preserves natural water flow pathways that may be bloked during soil core sampling for laboratory measurements. Vegetation must be removed from the plot prior the measurement...

  3. Dynamic Effect in the Capillary PressureSaturation Relationship and its Impacts on Unsaturated Flow

    E-print Network

    Hassanizadeh, S. Majid

    . A schematic depic-flow in unsaturated soils. While capillarity is ubiquitous in unsaturated tion of Pc vs. S curves is given in Fig. 1.analyses, the theoretical basis and practical implications of capillarity­saturation curves on the his- Capillarity plays a central role in the description of tory of flow is kno

  4. Calculation of the vapor-saturated liquidus for the NaCl-CO2-H2O system

    USGS Publications Warehouse

    Barton, P.B.; I-Ming, C.

    1993-01-01

    The polybaric liquidus surface for the H2O-rich corner of the NaCl-CO2-H2O ternary is calculated, relying heavily on 1. (1) a Henry's law equation for CO2 in brines (modified from Drummond, 1981), 2. (2) the assumption that the contributions of dissolved NaCl and CO2 in lowering the activity of H2O are additive, and 3. (3) data on the CO2 clathrate solid solution (nominally CO2 ?? 7.3H2O, but ranging from 5.75 to 8 or 9 H2O) from Bozzo et al. (1975). The variation with composition of the activity of CO2??7.3H2O, or any other composition within the clathrate field, is small, thereby simplifying the calculations appreciably. Ternary invariant points are 1. (1) ternary eutectic at -21.5??C, with ice + clathrate + hydrohalite NaCl-??H2O + brine mNaCl = 5.15, mco2 = 0.22 + vapor Ptotal ??? Pco2 = 5.7 atm; 2. (2) peritectic at -9.6??C, with clathrate + hydrohalite + liquid CO2 + brine mNaCl = 5.18, mco2 = 0.55 + vapor (Ptotal ??? Pco2 = 26.47 atm); and 3. (3) peritectic slightly below +0.1 ??C, with halite + hydrohalite + liquid CO2 + brine (mNaCl ??? 5.5, mco2 ??? 0.64) + vapor (Ptotal ??? Pco2 ??? 34 atm). CO2 isobars have been contoured on the ternary liquidus and also on the 25??C isotherm. An important caveat regarding the application of this information to the interpretation of the freezing-thawing behavior of fluid inclusions is that metastable behavior is a common characteristic of the clathrate. ?? 1993.

  5. The influence of ammonia on rapid-ther al low-pressure metalorganic chemical vapor deposited TIN, films from tetrakis (dimethylamido) titanium

    E-print Network

    Florida, University of

    The influence of ammonia on rapid-ther al low-pressure metalorganic chemical vapor deposited TIN, and stress of rapid- thermal low pressure metalorganic chemical vapor deposited (RT-LPMOCVD) TiN, films on In) liquid precursors, were studied. Enhanced deposition rates of l-3 nm s- ' at total chamber pressures

  6. Atmospheric pressure synthesis of photoluminescent hybrid materials by sequential organometallic vapor infiltration into polyethylene terephthalate fibers

    SciTech Connect

    Akyildiz, Halil I.; Mousa, Moataz Bellah M.; Jur, Jesse S.

    2015-01-28

    Exposing a polymer to sequential organometallic vapor infiltration (SVI) under low pressure conditions can significantly modify the polymer's chemical, mechanical, and optical properties. We demonstrate that SVI of trimethylaluminum into polyethylene terephthalate (PET) can also proceed readily at atmospheric pressure, and at 60?°C the extent of reaction determined by mass uptake is independent of pressure between 2.5?Torr and 760?Torr. At 120?°C, however, the mass gain is 50% larger at 2.5?Torr relative to that at 760?Torr, indicating that the precursor diffusion in the chamber and fiber matrix decreases at higher source pressure. Mass gain decreases, in general, as the SVI process temperature increases both at 2.5?Torr and 760?Torr attributed to the faster reaction kinetics forming a barrier layer, which prevents further diffusion of the reactive species. The resulting PET/Al-O{sub x} product shows high photoluminescence compared to untreated fibers. A physical mask on the polymer during infiltration at 760?Torr is replicated in the underlying polymer, producing an image in the polymer that is visible under UV illumination. Because of the reduced precursor diffusivity during exposure at 760?Torr, the image shows improved resolution compared to SVI performed under typical 2.5?Torr conditions.

  7. The separation and characterization of a hydrogen getter product mixture: Part 2, measurement of product vapor pressures

    SciTech Connect

    Fircish, D.W.; Shell, T.R.

    1987-06-04

    HCPB is the acronym of an organic hydrogen getter compound used in weapon systems. When this material scavenges hydrogen by reacting with it, a number of compounds are formed, each of which is more volatile than HCPB. It is desirable to know the vapor pressure of these products in order to assess their migration potential within the weapon. In this study, individual compounds from a reacted HCPB mixture were isolated and their vapor pressures were measured. Three of the four fractions examined with a modified capacitance manometer were found to have vapor pressures under 1 mtorr; the fourth was measured at 92 +- 15 mtorr. An attempt was made to obtain boiling point data on the two liquid components of the getter mixture, but they decomposed before reaching their boiling points.

  8. Tuning the Morphology of Solvent Annealed Thin Films of Polystyrene-b-Polyethylene Oxide with Controlled Saturations of Water and Toluene Vapors

    NASA Astrophysics Data System (ADS)

    Stahl, Brian C.; Kramer, Edward J.; Hawker, Craig J.

    2012-02-01

    Solvent annealing can be used to facilitate the self-assembly of block copolymer thin films and has several advantages over thermal annealing including room-temperature processing, domain orientation control and the ability to anneal polymers not amenable to thermal processing. We have developed a controlled process design for performing solvent annealing that incorporates continuous flows of solvent-saturated carrier gas, multiple simultaneous co-solvents and in-situ metrology. This new method is modular and applicable to a wide range of block copolymer and solvent systems. The control over annealing and quenching conditions afforded by this new technique allows us to reproducibly control the domain orientation and periodicity in thin films of cylinder-forming polystyrene-b-polyethylene oxide (PS-b-PEO) annealed in environments with high saturations of water and toluene vapors without modifying the block copolymer or substrate. By adjusting the humidity of the quenching gas flow we are able to control the orientation of the PEO cylinders, and by adjusting the humidity during annealing we are able to tune the domain spacing of PEO cylinders oriented perpendicular to the substrate.

  9. Detection and measurement of sulfur mustard (HD) offgassing from the weanling pig following exposure to saturated HD vapor. Technical report, September-October 1994

    SciTech Connect

    Logan, T.P.; Graham, J.S.; Martin, J.L.; Zallnick, J.E.; Jakubowski, E.M.

    1997-11-01

    Sulfur mustard (HD) is a chemical warfare agent for which there is neither antidote nor adequate therapeutic protection. Animal models are employed to investigate mechanisms of injury and to evaluate protective measures against HD exposure. Researchers whose experiments involve cutaneous application of HD vapor to animals benefit from the detection and quantitation of HD at the exposed site. The ability to detect and quantify HD enables the researcher to follow safe procedures in handling skin samples. We have designed an experimental procedure to measure HD offgassing from animal models. A Minicams(R), which is a portable gas chromatograph (GC) equipped with a flame photometric detector (FPD) and with online sorbent collection and desorption, was used to monitor the HD concentration. Confirming measurements were made using a two-step process that trapped HD on a Tenax sorbent offline and then transferred the sample by means of an ACEM 900 to a OC equipped with either FPD or a mass spectrometer (MS). We collected data from six experiments in which weanling pigs were exposed to saturated HD vapor via vapor caps containing 10 micro of HD. HD concentration was measured in time-weighted-average (TWA) units at a specific HD application site. The currently recommended exposure value for HD is 3 ng/l, 1 TWA unit. In five of the six experiments, Minicams HD concentration values were less than 0.5 TWA, 2 hours postexposure, and in one of the experiments, TWA Minicams concentration was less than 0.5 TWA, 5 hours post-exposure. OCIMS detection was used in three of the experiments to confirm Minicams data and to provide greater sensitivity and selectivity at 0.1 TWA. GC/MS data confirmed that HD concentrations fell below 0.1 TWA in less than S hours for a specific site.

  10. Frictional behavior of diamondlike carbon films in vacuum and under varying water vapor pressure.

    SciTech Connect

    Andersson, J.; Erck, R. A.; Erdemir, A.

    2002-03-25

    In this study, we investigated the frictional behavior of both hydrogenated and hydrogen-free diamondlike carbon (DLC) films in high vacuum (10{sup -6} Pa) at room temperature. Water was also introduced into the vacuum chamber to elucidate its effects on DLC film tribology. The hydrogen-free DLC (also referred to as tetrahedral amorphous carbon, or ta-C) was produced by an arc-PVD process, and the highly hydrogenated DLC was produced by plasma-enhanced chemical-vapor deposition. Tribological measurements of these films were made with a pin-on-disc machine with coated steel balls and coated steel discs in matched pairs under a 1 N load. The ball/disk pairs were rotated at sliding speeds in the range of 0.025-0.075 m/s. In vacuum, the steady-state friction coefficient of ta-C was of the order of 0.6 and the wear was severe, whereas for the highly hydrogenated film, friction was below 0.01, and in an optical microscope no wear could be detected. Adding water vapor to the sliding ta-C system in a vacuum chamber caused friction to decrease monotonically from 0.6 to {approx}0.05. In contrast, adding water vapor to the sliding DLC system caused the friction to increase linearly with pressure from 0.01 to 0.07. The results illustrate the importance of taking into account environmental conditions, especially the presence of water, when DLC films are being considered for a given application.

  11. Liquid-liquid and vapor-liquid phase equilibria for 1-butanol + water + 2-propanol at ambient pressure

    SciTech Connect

    Aicher, T.; Bamberger, T.; Schluender, E.U.

    1995-05-01

    The liquid-liquid and the vapor-liquid phase equilibria of the ternary system 1-butanol + water + 2-propanol have been measured at ambient pressure. Compositions along the binodal curve have been determined gravimetrically at 0, 20, 50, and 60 C. The lines were determined for 0, 20, and 60 C. The data were compared to reported measurements at 80 C. Furthermore, the vapor-liquid equilibrium at ambient pressure has been measured for both one-phase and two-phase liquid mixtures using a recirculation still proposed by Roeck and Sieg.

  12. Germanium determination by flame atomic absorption spectrometry: an increased vapor pressure-chloride generation system.

    PubMed

    Kaya, Murat; Volkan, Mürvet

    2011-03-15

    A new chloride generation system was designed for the direct, sensitive, rapid and accurate determination of the total germanium in complex matrices. It was aimed to improve the detection limit of chloride generation technique by increasing the vapor pressure of germanium tetrachloride (GeCl(4)). In order to do so, a novel joint vapor production and gas-liquid separation unit equipped with a home-made oven was incorporated to an ordinary nitrous oxide-acetylene flame atomic absorption spectrometer. Several variables such as reaction time, temperature and acid concentration have been investigated. The linear range for germanium determination was 0.1-10 ng mL(-1) for 1 mL sampling volume with a detection limit (3s) of 0.01 ng mL(-1). The relative standard deviation (RSD) was 2.4% for nine replicates of a 1 ng mL(-1) germanium solution. The method was validated by the analysis of one non-certified and two certified geochemical reference materials, respectively, CRM GSJ-JR-2 (Rhyolite), and GSJ-JR-1 (Rhyolite), and GBW 07107 (Chinese Rock). Selectivity of the method was investigated for Cd(2+), Co(2+), Cu(2+), Fe(3+), Ga(3+), Hg(2+), Ni(2+), Pb(2+), Sn(2+), and Zn(2+) ions and ionic species of As(III), Sb(III), Te(IV), and Se(IV). PMID:21315908

  13. Atmospheric Pressure Chemical Vapor Deposition of Graphene Using a Liquid Benzene Precursor.

    PubMed

    Kang, Cheong; Jung, Da Hee; Lee, Jin Seok

    2015-11-01

    Graphene has attracted great attention owing to its unique structural and electrical properties. Among various synthetic approaches of the graphene, metal assisted chemical vapor deposition (CVD) is the most reasonable and proper method to produce large-scale and low-defect graphene films. Until now, CVD from gaseous hydrocarbon sources has shown great promises for large-scale graphene growth, but high growth temperature is required for such growth. A recent work by using liquid benzene precursor has shown that monolayer graphene could be obtained at 300 degrees C by low pressure, required for high vacuum equipment. Here, we report the first successful attempt of atmospheric pressure CVD graphene growth on Cu foil using liquid benzene as a precursor. We investigated the effect of hydrogen partial pressure, growth time, and precursor temperature on the domain size of as-grown graphene. Also, micro-Raman analysis confirmed that these reaction parameters influenced the number of layer and uniformity of the graphene. PMID:26726650

  14. Vapor pressure and boiling point elevation of slash pine black liquors: Predictive models with statistical approach

    SciTech Connect

    Zaman, A.A.; McNally, T.W.; Fricke, A.L.

    1998-01-01

    Vapor-liquid equilibria and boiling point elevation of slash pine kraft black liquors over a wide range of solid concentrations (up to 85% solids) has been studied. The liquors are from a statistically designed pulping experiment for pulping slash pine in a pilot scale digester with four cooking variables of effective alkali, sulfidity, cooking time, and cooking temperature. It was found that boiling point elevation of black liquors is pressure dependent, and this dependency is more significant at higher solids concentrations. The boiling point elevation data at different solids contents (at a fixed pressure) were correlated to the dissolved solids (S/(1 {minus} S)) in black liquor. Due to the solubility limit of some of the salts in black liquor, a change in the slope of the boiling point elevation as a function of the dissolved solids was observed at a concentration of around 65% solids. An empirical method was developed to describe the boiling point elevation of each liquor as a function of pressure and solids mass fraction. The boiling point elevation of slash pine black liquors was correlated quantitatively to the pulping variables, using different statistical procedures. These predictive models can be applied to determine the boiling point rise (and boiling point) of slash pine black liquors at processing conditions from the knowledge of pulping variables. The results are presented, and their utility is discussed.

  15. Vapor pressure response to denaturant and water in E10 blends.

    PubMed

    Timpe, R C; Wu, L

    1995-01-01

    On December 16, 1993, the U.S. Environmental Protection Agency (EPA) released the final rule on reformulated gasoline (RFG). This rule will affect the composition of as much as 45% of the gasoline used in the United States by the summer of 1995. The acceptance of any gasoline component lies in its ability to contribute to the RFG program's environmental goals. This study was conducted to determine the effect of water and ethanol denaturant on gasoline Reid vapor pressure (RVP) for which little quantitative data are available. This paper addresses two new areas where environmental goals may be achieved while maintaining the use of ethanol-blended gasolines within ozone nonattainment areas. PMID:15658166

  16. Effect of Vapor Pressure Scheme on Multiday Evolution of SOA in an Explicit Model

    NASA Astrophysics Data System (ADS)

    Lee-Taylor, J.; Madronich, S.; Aumont, B.; Camredon, M.; Emmons, L. K.; Tyndall, G. S.; Valorso, R.

    2011-12-01

    Recent modeling of the evolution of Secondary Organic Aerosol (SOA) has led to the critically important prediction that SOA mass continues to increase for several days after emission of primary pollutants. This growth of organic aerosol in dispersing plumes originating from urban point sources has direct implications for regional aerosol radiative forcing. We investigate the robustness of predicted SOA mass growth downwind of Mexico City in the model GECKO-A (Generator of Explicit Chemistry and Kinetics of Organics in the Atmosphere), by assessing its sensitivity to the choice of vapor pressure prediction scheme. We also explore the implications for multi-day SOA mass growth of glassification / solidification of SOA constituents during aging. Finally we use output from the MOZART-4 chemical transport model to evaluate our results in the regional and global context.

  17. Vapor Pressure of Three Brominated Flame Retardants Determined via Knudsen Effusion Method

    PubMed Central

    Fu, Jinxia; Suuberg, Eric M.

    2012-01-01

    Brominated flame retardants (BFRs) have been used in a variety of consumer products in the past four decades. The vapor pressures for three widely used BFRs, that is, tetrabromobisphenol A (TBBPA), hexabromocyclododecane (HBCD), and octabromodiphenyl ethers (octaBDEs) mixtures, were determined using the Knudsen effusion method and compared to those of decabromodiphenyl ether (BDE209). The values measured extrapolated to 298.15 K are 8.47 × 10?9, 7.47 × 10?10, and 2.33 × 10?9 Pa, respectively. The enthalpies of sublimation for these BFRs were estimated using the Clausius-Clapeyron equation and are 143.6 ± 0.4, 153.7 ± 3.1, and 150.8 ± 3.2 kJ/mole, respectively. In addition, the enthalpies of fusion and melting temperatures for these BFRs were also measured in the present study. PMID:22213441

  18. Net vapor generation point in boiling flow of trichlorotrifluoroethane at high pressures

    NASA Technical Reports Server (NTRS)

    Dougall, R. S.; Lippert, T. E.

    1973-01-01

    The conditions at which the void in subcooled boiling starts to undergo a rapid increase were studied experimentally. The experiments were performed in a 12.7 x 9.5 mm rectangular channel. Heating was from a 3.2 mm wide strip embedded in one wall. The pressure ranged from 9.45 to 20.7 bar, mass velocity from 600 to 7000 kg/sq m sec, and subcooling from 16 to 67 C. Photographs were used to determine when detached bubbles first appeared in the bulk flow. Measurements of bubble layer thickness along the wall were also made. Results showed that the point of net vapor generation is close to the occurrence of fully-developed boiling.

  19. Fabrication of Planar Heterojunction Perovskite Solar Cells by Controlled Low-Pressure Vapor Annealing.

    PubMed

    Li, Yanbo; Cooper, Jason K; Buonsanti, Raffaella; Giannini, Cinzia; Liu, Yi; Toma, Francesca M; Sharp, Ian D

    2015-02-01

    A new method for achieving high efficiency planar CH3NH3I3-xClx perovskite photovoltaics, based on a low pressure, reduced temperature vapor annealing is demonstrated. Heterojunction devices based on this hybrid halide perovskite exhibit a top PCE of 16.8%, reduced J-V hysteresis, and highly repeatable performance without need for a mesoporous or nanocrystalline metal oxide layer. Our findings demonstrate that large hysteresis is not an inherent feature of planar heterojunctions, and that efficient charge extraction can be achieved with uniform halide perovskite materials with desired composition. X-ray diffraction, valence band spectroscopy, and transient absorption measurements of these thin films reveal that structural modifications induced by chlorine clearly dominate over chemical and electronic doping effects, without affecting the Fermi level or photocarrier lifetime in the material. PMID:26261969

  20. A search for chemical laser action in low pressure metal vapor flames. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Zwillenberg, M. L.

    1975-01-01

    Optical emissions were studied from low pressure (approximately 1 torr) dilute diffusion flames of Ca and Mg vapor with O2, N2O and mixtures of CCl4 and O2. The Ca flames with O2 and N2O revealed high vibrational excitation of the product CaO molecule (up to v=30). The flames with CCl4 revealed extreme nonequilibrium metal atom electronic excitation, up to the metal atom ionization limit (6.1 eV for Ca, 7.6 eV for Mg). The metal atom excited electronic state populations did not follow a Boltzmann distribution, but the excitation rates ('pumping rate') were found to obey an Arrhenius-type expression, with the electronic excitation energy playing the role of activation energy and a temperature of about 5000 K for triplet excited states and 2500 K for singlets (vs. approximately 500 K translational temperature).

  1. The Vapor Pressure of Palladium at Temperatures up to 1973K

    NASA Technical Reports Server (NTRS)

    Gardner, K. G.; Feguson, F. T.; Nuth, J. A.

    2005-01-01

    Understanding high-temperature processes is imperative for modeling the formation of the solar system. It is unfortunate that since the 1950 s little has been done in the area of thermodynamics to continue gaining information on metals such as iron (Fe), nickel (Ni), cobalt (Co), palladium (Pd) and many others. Although the vapor pressures of these metals can be extrapolated to higher temperatures, the data is often limited to temperature ranges too low to be applicable to processes that occur during the formation of the solar system (T approx. 2000K). Experimental techniques inhibited the data in the past by restricting the testing of metals to temperatures below their melting point. Today, higher temperature testing is possible by using a Thermo- Cahn Thermogravimetric system that is able to reach temperatures up to 1973K in vacuo and measure a 10 gram change in a sample with mass of up to 100 grams.

  2. Diamond synthesis at atmospheric pressure by microwave capillary plasma chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Hemawan, Kadek W.; Gou, Huiyang; Hemley, Russell J.

    2015-11-01

    Polycrystalline diamond has been synthesized on silicon substrates at atmospheric pressure, using a microwave capillary plasma chemical vapor deposition technique. The CH4/Ar plasma was generated inside of quartz capillary tubes using 2.45 GHz microwave excitation without adding H2 into the deposition gas chemistry. Electronically excited species of CN, C2, Ar, N2, CH, H?, and H? were observed in the emission spectra. Raman measurements of deposited material indicate the formation of well-crystallized diamond, as evidenced by the sharp T2g phonon at 1333 cm-1 peak relative to the Raman features of graphitic carbon. Field emission scanning electron microscopy images reveal that, depending on the growth conditions, the carbon microstructures of grown films exhibit "coral" and "cauliflower-like" morphologies or well-facetted diamond crystals with grain sizes ranging from 100 nm to 10 ?m.

  3. Crystal growth by a modified vapor pressure-controlled Czochralski (VCz) technique

    NASA Astrophysics Data System (ADS)

    Neubert, M.; Rudolph, P.; Frank-Rotsch, Ch.; Czupalla, M.; Trompa, K.; Pietsch, M.; Jurisch, M.; Eichler, St.; Weinert, B.; Scheffer-Czygan, M.

    2008-04-01

    A modified vapor pressure-controlled Czochralski (VCz) method is reported which employs a diving bell around the growing crystal. Semi-insulating (SI) GaAs crystals with a diameter of 160 mm and an overall length up to 220 mm were grown from melts of up to 23 kg, and compared with similar-sized crystals grown using a standard liquid-encapsulation Czochralski (LEC) process. Optimization of the VCz process was assisted by global numerical simulations. A slightly convex growth interface has been found to be the most suitable one for achieving a relatively low EPD of ˜10 4 cm -2, with an associated reduction in the probability of dislocation bunching. The carbon concentration of the crystals was controlled down to values of 10 14 cm -3. The electrical properties, including the EL2° content are discussed.

  4. The Action of Pressure-Radiation Forces on Pulsating Vapor Bubbles

    NASA Technical Reports Server (NTRS)

    Hao, Y.; Oguz, N.; Prosperetti, A.

    2001-01-01

    The action of pressure-radiation (or Bjerknes) forces on gas bubbles is well understood. This paper studies the analogous phenomenon for vapor bubbles, about which much less is known. A possible practical application is the removal of boiling bubbles from the neighborhood of a heated surface in the case of a downward facing surface or in the absence of gravity. For this reason, the case of a bubble near a plane rigid surface is considered in detail. It is shown that, when the acoustic wave fronts are parallel to the surface, the bubble remains trapped due to secondary Bjerknes force caused by an "image bubble." When the wave fronts are perpendicular to the surface, on the other hand, the bubble can be made to slide laterally.

  5. Reid vapor-pressure regulation of gasoline, 1987-1990. Master's thesis

    SciTech Connect

    Butters, R.A.

    1990-09-30

    Although it is generally only a summertime problem, smog, as represented by its criteria pollutant, ozone, is currently the number one air pollution problem in the United States. Major contributors to smog formation are the various Volatile Organic Compounds (VOC's) which react with other chemicals in the atmosphere to form the ozone and other harmful chemicals known as smog. Gasoline is a major source of VOC's, not only as it is burned in car engines, but as it evaporates. Gasoline evaporates in storage tanks, as it is transferred during loading and refueling operations, and in automobiles, both while they are running and while parked in the driveway. In 1987, the United States Environmental Protection Agency began an almost unprecedented effort to reduce the evaporative quality of commercial gasolines by mandating reductions in its Reid Vapor Pressure (RVP).

  6. Partial Pressures for Several In-Se Compositions from Optical Absorbance of the Vapor

    NASA Technical Reports Server (NTRS)

    Brebrick, R. F.; Su, Ching-Hua

    2001-01-01

    The optical absorbance of the vapor phase over various In-Se compositions between 33.3-60.99 at.% Se and 673-1418 K was measured and used to obtain the partial pressures of Se2(g) and In2Se(g). The results are in agreement with silica Bourdon gauge measurements for compositions between 50-61 at.%, but significantly higher than those from Knudsen cell and simultaneous Knudsen-torsion cell measurements. It is found that 60.99 at.% Se lies outside the sesquiselenide homogeneity range and 59.98 at.% Se lies inside and is the congruently melting composition. The Gibbs energy of formation of the liquid from its pure liquid elements between 1000-1300 K is essentially independent of temperature and falls between -36 to -38 kJ per g atomic weight for 50 and 56% Se at 1200 and 1300 K.

  7. CO(2) partial pressure and calcite saturation in springs - useful data for identifying infiltration areas in mountainous environments.

    PubMed

    Hilberg, Sylke; Brandstätter, Jennifer; Glück, Daniel

    2013-04-01

    Mountainous regions such as the Central European Alps host considerable karstified or fractured groundwater bodies, which meet many of the demands concerning drinking water supply, hydropower or agriculture. Alpine hydrogeologists are required to describe the dynamics in fractured aquifers in order to assess potential impacts of human activities on water budget and quality. Delineation of catchment areas by means of stable isotopes and hydrochemical data is a well established method in alpine hydrogeology. To achieve reliable results, time series of (at least) one year and spatial and temporal close-meshed data are necessary. In reality, test sites in mountainous regions are often inaccessible due to the danger of avalanches in winter. The aim of our work was to assess a method based on the processes within the carbonic acid system to delineate infiltration areas by means of single datasets consisting of the main hydrochemical parameters of each spring. In three geologically different mountainous environments we managed to classify the investigated springs into four groups. (1) High PCO2 combined with slight super-saturation in calcite, indicating relatively low infiltration areas. (2) Low PCO2 near atmospheric conditions in combination with calcite saturation, which is indicative of relatively high infiltration areas and a fractured aquifer which is not covered by topsoil layers. (3) High PCO2 in combination with sub-saturation in calcite, representing a shallow aquifer with a significant influence of the topsoil layer. (4) The fourth group of waters is characterized by low PCO2 and sub-saturation in calcite, which is interpreted as evidence for a shallow aquifer without significant influence of any hard rock aquifer or topsoil layer. This study shows that CO2-partial pressure can be an ideal natural tracer to estimate the elevation of infiltration areas, especially in non-karstified fractured groundwater bodies. PMID:23429574

  8. Photosynthetic photon flux density, carbon dioxide concentration, and vapor pressure deficit effects on photosynthesis in cacao seedlings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cacao (Theobroma cacao) is a shade plant, native to the under-story of the evergreen rain forest of the Amazon basin and adapted to low levels of photosynthetic photon flux density (PPFD). The influence of PPFD, leaf to air water vapor pressure deficit (VPD) and external carbon dioxide concentration...

  9. An Integrated Approach to Introducing Biofuels, Flash Point, and Vapor Pressure Concepts into an Introductory College Chemistry Lab

    ERIC Educational Resources Information Center

    Hoffman, Adam R.; Britton, Stephanie L.; Cadwell, Katie D.; Walz, Kenneth A.

    2011-01-01

    Students explore the fundamental chemical concepts of vapor pressure and flash point in a real-world technical context, while gaining insight into the contemporary societal issue of biofuels. Lab activities were developed using a closed-cup instrument to measure the flash point of various biodiesel samples. Pre- and post-tests revealed that the…

  10. Vapor pressure and evaporation rate of certain heat-resistant compounds in a vacuum at high temperatures

    NASA Technical Reports Server (NTRS)

    Bolgar, A. S.; Verkhoglyadova, T. S.; Samsonov, G. V.

    1985-01-01

    The vapor pressure and evaporation rate of borides of titanium, zirconium, and chrome; and of strontium and carbides of titanium, zirconium, and chrome, molybdenum silicide; and nitrides of titanium, niobium, and tantalum in a vacuum were studied. It is concluded that all subject compounds evaporate by molecular structures except AlB sub 12' which dissociates, losing the aluminum.

  11. COMPUTATIONAL CHEMISTRY METHOD FOR PREDICTING VAPOR PRESSURES AND ACTIVITY COEFFICIENTS OF POLAR ORGANIC OXYGENATES IN PM2.5

    EPA Science Inventory

    Parameterizations of interactions of polar multifunctional organic oxygenates in PM2.5 must be included in aerosol chemistry models for evaluating control strategies for reducing ambient concentrations of PM2.5 compounds. Vapor pressures and activity coefficients of these compo...

  12. Temperature influences the ability of tall fescue to control transpiration in response to atmospheric vapor pressure deficit

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water availability for turfgrass systems is often limited, and likely to become more so in the future. These experiments examined the ability of tall fescue (Festuca arundinacea Schreb.) to control transpiration with increasing vapor pressure deficit and whether control was influenced by temperature...

  13. DETERMINATION OF THE VAPOR PRESSURES OF SELECT POLYCHLORINATED DIBENZO-P-DIOXINS AND DIBENZOFURANS AT 75–275°C

    EPA Science Inventory

    Vapor pressures were determined for several polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) at 75–275°C, extending the available literature data to more relevant temperature regions and providing the first experimental data for 2,3,7...

  14. The impact of rock and fluid uncertainties in the estimation of saturation and pressure from a 4D petro elastic inversion

    NASA Astrophysics Data System (ADS)

    Pazetti, Bruno; Davolio, Alessandra; Schiozer, Denis J.; UNICAMP

    2015-08-01

    The integration of 4D seismic (4DS) attributes and reservoir simulation is used to reduce risks in the management of petroleum fields. One possible alternative is the saturation and pressure domain. In this case, we use estimations of saturation and pressure changes from 4D seismic data as input in history matching processes to yield more reliable production predictions in simulation models. The estimation of dynamic changes from 4DS depends on the knowledge of reservoir rock and fluid properties that are uncertain in the process of estimation. This paper presents a study of the impact of rock and fluid uncertainties on the estimation of saturation and pressure changes achieved through a 4D petro-elastic inversion. The term impact means that the saturation and pressure estimation can be perturbed by the rock and fluid uncertainties. The motivation for this study comes from the necessity to estimate uncertainties in saturation and pressure variation to incorporate them in the history matching procedures, avoiding the use of deterministic values from 4DS, which may not be reliable. The study is performed using a synthetic case with known response from where it is possible to show that the errors of estimated saturation and pressure depend on the magnitude of rock and fluid uncertainties jointly with the reservoir dynamic changes. The main contribution of this paper is to show how uncertain reservoir properties can affect the reliability of pressure and saturation estimation from 4DS and how it depends on reservoir changes induced by production. This information can be used in future projects which use quantitative inversion to integrate reservoir simulation and 4D seismic data.

  15. Atmospheric-Pressure Chemical Vapor Deposition of Iron Pyrite Thin Films

    SciTech Connect

    Berry, Nicholas; Cheng, Ming; Perkins, Craig L.; Limpinsel, Moritz; Hemminger, John C.; Law, Matt

    2012-10-23

    Iron pyrite (cubic FeS{sub 2}) is a promising candidate absorber material for earth-abundant thin-film solar cells. In this report, single-phase, large-grain, and uniform polycrystalline pyrite thin films are fabricated on glass and molybdenum-coated glass substrates by atmospheric-pressure chemical vapor deposition (AP-CVD) using the reaction of iron(III) acetylacetonate and tert-butyl disulfide in argon at 300 C, followed by sulfur annealing at 500--550 C to convert marcasite impurities to pyrite. The pyrite-marcasite phase composition depends strongly on the concentration of sodium in the growth substrate and the sulfur partial pressure during annealing. Phase and elemental composition of the films are characterized by X-ray diffraction, Raman spectroscopy, Auger electron spectroscopy, secondary ion mass spectrometry, Rutherford backscattering spectrometry, and X-ray photoelectron spectroscopy. The in-plane electrical properties are surprisingly insensitive to phase and elemental impurities, with all films showing p-type, thermally activated transport with a small activation energy ({approx}30 meV), a room- temperature resistivity of {approx}1 {Omega} cm, and low mobility. These ubiquitous electrical properties may result from robust surface effects. These CVD pyrite thin films are well suited to fundamental electrical studies and the fabrication of pyrite photovoltaic device stacks.

  16. Comprehensive characterization of temperature- and pressure-induced bilayer phase transitions for saturated phosphatidylcholines containing longer chain homologs.

    PubMed

    Goto, Masaki; Endo, Takuya; Yano, Takahiro; Tamai, Nobutake; Kohlbrecher, Joachim; Matsuki, Hitoshi

    2015-04-01

    Complete elucidation of the phase behavior of phospholipid bilayers requires information on the subtransition from the lamellar crystal (Lc) phase to the gel phase. However, for bilayers of saturated diacylphosphatidylcholines (CnPCs), especially longer chain homologs, equilibration in the Lc phase is known to be very slow. In this study, bilayer phase transitions of three CnPCs with longer acyl chains, C19PC, C20PC and C21PC, were observed by differential scanning calorimetry under atmospheric pressure and by light-transmittance measurements under high pressure. Using lipid samples treated by thermal annealing enabled the observation of the sub-, pre- and main transitions of the C19PC and C20PC bilayers under atmospheric pressure. Only the pre- and main transitions could be observed for the C21PC bilayer due to very slow kinetics of the Lc phase formation for lipids with long acyl chains. The temperature and pressure phase diagrams constructed and phase-transitions quantities (enthalpy, entropy and volume changes) evaluated for these bilayers were compared with one another and with those of bilayers of the CnPC homologs examined in previous studies. These results allowed us (1) to clarify the temperature- and pressure-dependent phase sequence and phase stability of the CnPC (n=12-22) bilayers as a function of the hydrophobicity of the molecules, (2) to prove the presence of a shorter and a longer limit (n=13 and 21) in the acyl chain length for the pressure-induced bilayer interdigitation and (3) to reveal the chain-length dependence of the thermodynamic quantities of the subtransitions including the volume change. PMID:25779604

  17. High-power quantum cascade lasers grown by low-pressure metal organic vapor-phase epitaxy operating in continuous wave above 400 K

    E-print Network

    Loncar, Marko

    by metal organic vapor-phase epitaxy MOVPE is central since this technique is a widely established platform to be 70%. The QCLs investigated here were grown by low- pressure MOVPE in a standard reactor equippedHigh-power quantum cascade lasers grown by low-pressure metal organic vapor-phase epitaxy operating

  18. Highly stable silicon dioxide films deposited by means of rapid thermal -low-pressure chemical vapor deposition onto InP

    E-print Network

    Florida, University of

    grown by rapid thermal, low-pressure chemical vapor deposition (RT-LPCVD), using pure oxygen (0,) and 2Highly stable silicon dioxide films deposited by means of rapid thermal - low-pressure chemical vapor deposition onto InP A. Katz, A. Feingold, U. K. Chakrabarti, and S. J. Peat-ton AT&T Bell

  19. The influence of substrate polarity on the structural quality of InN layers grown by high-pressure chemical vapor deposition

    E-print Network

    Dietz, Nikolaus

    the growth temperatures to below 650 °C for low-pressure metal organic chemical vapor depo- sition MOCVDThe influence of substrate polarity on the structural quality of InN layers grown by high-pressure chemical vapor deposition N. Dietz,1,a M. Alevli,1 R. Atalay,1 G. Durkaya,1 R. Collazo,2 J. Tweedie,2 S

  20. Solving the Goddard problem with thrust and dynamic pressure constraints using saturation functions

    E-print Network

    in 1919 (God- dard, 1919) concerns maximizing the final altitude of a rocket launched in vertical of a vertically ascending rocket subject to dynamic pressure and thrust constraints. The Goddard problem is used arc behavior in connection with a relatively simple model structure, which makes the God- dard rocket

  1. Transport of Carbon Tetrachloride in a Fractured Vadose Zone due to Atmospheric Pressure Fluctuations, Diffusion, and Vapor Density

    NASA Astrophysics Data System (ADS)

    McCray, J. E.; Downs, W.; Falta, R. W.; Housley, T.

    2005-12-01

    DNAPL sources of carbon tetrachloride (CT) vapors are of interest at the Radioactive Waste Management Complex (RWMC) at the Idaho National Engineering and Environmental Laboratory (INEEL). The site is underlain by thick fractured basalt that includes sedimentary interbeds, each are a few meters thick. Daily atmospheric pressure fluctuations serve as driving forces for CT vapor transport in the subsurface. Other important transport processes for vapor movement include gas-phase diffusion and density-driven transport. The objective of this research is to investigate the influence and relative importance of these processes on gaseous transport of CT. Gas pressure and vapor concentration measurements were conducted at various depths in two wells. A numerical multiphase flow model (TOUGH2), calibrated to field pressure data, is used to conduct sensitivity analyses to elucidate the importance of the different transport mechanisms. Results show that the basalt is highly permeable to vertical air flow. The pressure dampening occurs mainly in the sedimentary interbeds. Model-calibrated permeability values for the interbeds are similar to those obtained in a study by the U.S. Geological Survey for shallow sediments, and an order of magnitude higher than column-scale values obtained by previous studies conducted by INEEL scientists. The transport simulations indicate that considering the effect of barometric pressure changes is critical to simulating transport of pollutants in the vadose zone above the DNAPL source. Predicted concentrations can be orders of magnitude smaller than actual concentrations if the effect is not considered. Below the DNAPL vapor source, accounting for density and diffusion alone would yield acceptable results provided that a 20% error in concentrations are acceptable, and that simulating concentrations trends (and not actual concentrations) is the primary goal.

  2. Determining the stable isotope composition of pore water from saturated and unsaturated zone core: improvements to the direct vapor equilibration laser spectroscopy method

    NASA Astrophysics Data System (ADS)

    Hendry, M. J.; Schmeling, E.; Wassenaar, L. I.; Barbour, S. L.; Pratt, D.

    2015-06-01

    A method to measure the ?2H and ?18O composition of pore waters in saturated and unsaturated geologic core samples using direct vapor equilibration and laser spectroscopy (DVE-LS) was first described in 2008, and has since been widely adopted by others. Here, we describe a number of important methodological improvements and limitations encountered in routine application of DVE-LS over several years. Generally, good comparative agreement and accuracy is obtained between core pore water isotopic data obtained using DVE-LS and that measured on water squeezed from the same core. In complex hydrogeologic settings, high-resolution DVE-LS depth profiles provide greater spatial resolution of isotopic profiles compared to long-screened or nested piezometers. When fluid is used during drilling and coring (e.g., water rotary or wet sonic drill methods), spiking the drill fluid with 2H can be conducted to identify core contamination. DVE-LS analyses yield accurate formational isotopic data for fine-textured core (e.g., clay, shale) samples, but are less effective for cores obtained from saturated permeable (e.g., sand, gravels) geologic media or on chip samples that are easily contaminated by wet rotary drilling fluid. Data obtained from DVE-LS analyses of core samples collected using wet (contamination by drill water) and dry sonic (water loss by heating) methods were also problematic. Accurate DVE-LS results can be obtained on core samples with gravimetric water contents < 5 % by increasing the sample size tested. Inexpensive Ziploc™ gas sampling bags were determined to be as good as, if not better, than other, more expensive bags. Sample storage in gas tight sample bags provides acceptable results for up to 10 days of storage; however, measureable water loss and evaporitic isotopic enrichment occurs for samples stored for up to 6 months. With appropriate care taken during sample collection and storage, the DVE-LS approach for obtaining high resolution pore water isotopic data remains a promising alternative to study the hydrogeology of saturated and unsaturated sediments. Eliminating analytical interferences from volatile organics remains a challenge.

  3. A modeling approach to represent hysteresis in capillary pressure-saturation relationship based on fluid connectivity in void space

    NASA Astrophysics Data System (ADS)

    Cihan, Abdullah; Birkholzer, Jens; Illangasekare, Tissa H.; Zhou, Quanlin

    2014-01-01

    This study presents a new model for description of hysteretic constitutive relationships between capillary pressure and saturation under capillary-dominated multiphase flow conditions in porous media. Hysteretic relationships are required for accurate prediction of spatial and temporal distribution of multiphase fluids in response to successively occurring drainage and imbibition events in porous media. In addition to contact angle effects, connectivity of the void space in the porous medium plays a central role for the macroscopic manifestation of hysteresis behavior and capillary entrapment of wetting and nonwetting fluids. The hysteretic constitutive model developed in this work uses void-size distribution and a measure of connectivity for void space to compute the hysteretic curves and to predict entrapped fluid-phase saturations. Two functions, the drainage connectivity function and the wetting connectivity function, are introduced to characterize connectivity of fluids in void space during drainage and wetting processes. These functions can be estimated through pore-scale simulations in computer-generated porous media or from traditional experimental measurements of primary drainage and main wetting curves. The hysteresis model results are verified by comparing the model predicted scanning curves with 3-D pore-scale simulations as well as with actual data sets obtained from column experiments found in the literature.

  4. Synthetic fluid inclusions XIX. Experimental determination of the vapor-saturated liquidus of the system H2O-NaCl-FeCl2

    NASA Astrophysics Data System (ADS)

    Lecumberri-Sanchez, Pilar; Steele-MacInnis, Matthew; Bodnar, Robert J.

    2015-01-01

    Magmatic-hydrothermal fluids associated with felsic to intermediate composition magmas are generally dominated by (Na ± K)Cl, but often the fluids also contain significant concentrations of FeCl2. Previously, fluid inclusions containing such fluids were interpreted using the properties of H2O-NaCl because the effect of FeCl2 on the phase equilibrium and volumetric (PVTx) properties of aqueous fluids was essentially unknown. In this study, synthetic fluid inclusion experiments have been conducted to determine the vapor-saturated liquidus phase relations of the system H2O-NaCl-FeCl2. Microthermometric and microanalytical measurements on synthetic fluid inclusions have been combined with the limited existing data, as well as with predictions based on Pitzer's formalism, to determine the ternary cotectic and peritectic phase boundaries and liquidus fields. The liquidus is qualitatively similar to those of other ternary systems of H2O-NaCl plus divalent-cation chlorides (MgCl2 and CaCl2) and has been characterized through empirical equations that represent the liquid salinity on the ice- and halite-liquidus surfaces. The ice and halite liquidi intersect at a metastable cotectic curve, which can be used to determine fluid compositions in this system if metastable behavior is observed. Furthermore, based on the experimentally determined liquidus, bulk salinities of natural fluid inclusions can be determined from the last dissolution temperatures of ice and/or halite using the new empirical equations.

  5. Methods for calculation of engineering parameters for gas separation. [vapor pressure and solubility of gases in organic liquids

    NASA Technical Reports Server (NTRS)

    Lawson, D. D.

    1979-01-01

    A group additivity method is generated which allows estimation, from the structural formulas alone, of the energy of vaporization and the molar volume at 25 C of many nonpolar organic liquids. Using these two parameters and appropriate thermodynamic relations, the vapor pressure of the liquid phase and the solubility of various gases in nonpolar organic liquids are predicted. It is also possible to use the data to evaluate organic and some inorganic liquids for use in gas separation stages or liquids as heat exchange fluids in prospective thermochemical cycles for hydrogen production.

  6. An improved method for simultaneous determination of frictional pressure drop and vapor volume fraction in vertical flow boiling

    NASA Technical Reports Server (NTRS)

    Klausner, J. F.; Chao, B. T.; Soo, S. L.

    1990-01-01

    The two-phase frictional pressure drop and vapor volume fraction in the vertical boiling and adiabatic flow of the refrigerant, R11, have been simultaneously measured by a liquid balancing column and differential magnetic reluctance pressure transducers. An account is given of the experimental apparatus and procedure, data acquisition and analysis, and error estimation employed. All values of two-phase multipliers evaluated on the basis of the measured frictional pressure drop data in vertical upflow fall in the range bounded by the predictions of the Chisholm correlation and the homogeneous model.

  7. Differential equations governing slip-induced pore-pressure fluctuations in a water-saturated granular medium

    USGS Publications Warehouse

    Iverson, R.M.

    1993-01-01

    Macroscopic frictional slip in water-saturated granular media occurs commonly during landsliding, surface faulting, and intense bedload transport. A mathematical model of dynamic pore-pressure fluctuations that accompany and influence such sliding is derived here by both inductive and deductive methods. The inductive derivation shows how the governing differential equations represent the physics of the steadily sliding array of cylindrical fiberglass rods investigated experimentally by Iverson and LaHusen (1989). The deductive derivation shows how the same equations result from a novel application of Biot's (1956) dynamic mixture theory to macroscopic deformation. The model consists of two linear differential equations and five initial and boundary conditions that govern solid displacements and pore-water pressures. Solid displacements and water pressures are strongly coupled, in part through a boundary condition that ensures mass conservation during irreversible pore deformation that occurs along the bumpy slip surface. Feedback between this deformation and the pore-pressure field may yield complex system responses. The dual derivations of the model help explicate key assumptions. For example, the model requires that the dimensionless parameter B, defined here through normalization of Biot's equations, is much larger than one. This indicates that solid-fluid coupling forces are dominated by viscous rather than inertial effects. A tabulation of physical and kinematic variables for the rod-array experiments of Iverson and LaHusen and for various geologic phenomena shows that the model assumptions commonly are satisfied. A subsequent paper will describe model tests against experimental data. ?? 1993 International Association for Mathematical Geology.

  8. The Evolution of Mechanisms Driving the Stomatal Response to Vapor Pressure Deficit1[OPEN

    PubMed Central

    McAdam, Scott A.M.; Brodribb, Timothy J.

    2015-01-01

    Stomatal responses to vapor pressure deficit (VPD) are a principal means by which vascular land plants regulate daytime transpiration. While much work has focused on characterizing and modeling this response, there remains no consensus as to the mechanism that drives it. Explanations range from passive regulation by leaf hydration to biochemical regulation by the phytohormone abscisic acid (ABA). We monitored ABA levels, leaf gas exchange, and water status in a diversity of vascular land plants exposed to a symmetrical, mild transition in VPD. The stomata in basal lineages of vascular plants, including gymnosperms, appeared to respond passively to changes in leaf water status induced by VPD perturbation, with minimal changes in foliar ABA levels and no hysteresis in stomatal action. In contrast, foliar ABA appeared to drive the stomatal response to VPD in our angiosperm samples. Increased foliar ABA level at high VPD in angiosperm species resulted in hysteresis in the recovery of stomatal conductance; this was most pronounced in herbaceous species. Increased levels of ABA in the leaf epidermis were found to originate from sites of synthesis in other parts of the leaf rather than from the guard cells themselves. The transition from a passive regulation to ABA regulation of the stomatal response to VPD in the earliest angiosperms is likely to have had critical implications for the ecological success of this lineage. PMID:25637454

  9. Threefold atmospheric-pressure annealing for suppressing graphene nucleation on copper in chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Suzuki, Seiya; Nagamori, Takashi; Matsuoka, Yuki; Yoshimura, Masamichi

    2014-09-01

    Chemical vapor deposition (CVD) is a promising method of producing a large single-crystal graphene on a catalyst, especially on copper (Cu), and a further increase in domain size is desirable for electro/optic applications. Here, we report on threefold atmospheric-pressure (ATM) annealing for suppressing graphene nucleation in atmospheric CVD. Threefold ATM annealing formed a step and terrace surface of the underlying Cu, in contrast to ATM annealing. Atomic force microscopy and Auger electron mapping revealed that Si-containing particles existed on threefold-ATM- and ATM-annealed surfaces; particles on Cu had a lower density after threefold ATM annealing than after ATM annealing. The formation of a step and terrace surface and the lower density of particles following the threefold ATM annealing would play a role in reducing graphene nucleation. By combining threefold ATM annealing and electropolishing of Cu, the nucleation of graphene was effectively suppressed, and a submillimeter-sized hexagonal single-crystal graphene was successfully obtained.

  10. High vapor pressure deficit drives salt-stress-induced rice yield losses in India.

    PubMed

    Tack, Jesse; Singh, Rakesh K; Nalley, Lawton L; Viraktamath, Basavaraj C; Krishnamurthy, Saraswathipura L; Lyman, Nate; Jagadish, Krishna S V

    2015-04-01

    Flooded rice is grown across wide geographic boundaries from as far north as Manchuria and as far south as Uruguay and New South Wales, primarily because of its adaptability across diverse agronomic and climatic conditions. Salt-stress damage, a common occurrence in delta and coastal rice production zones, could be heightened by the interactions between high temperature and relative humidity (vapor pressure deficit--VPD). Using temporal and spatial observations spanning 107 seasons and 19 rice-growing locations throughout India with varying electrical conductivity (EC), including coastal saline, inland saline, and alkaline soils, we quantified the proportion of VPD inducing salinity damage in rice. While controlling for time-invariant factors such as trial locations, rice cultivars, and soil types, our regression analysis indicates that EC has a nonlinear detrimental effect on paddy rice yield. Our estimates suggest these yield reductions become larger at higher VPD. A one standard deviation (SD) increase in EC from its mean value is associated with 1.68% and 4.13% yield reductions at median and maximum observed VPD levels, respectively. Yield reductions increase roughly sixfold when the one SD increase is taken from the 75th percentile of EC. In combination, high EC and VPD generate near catastrophic crop loss as predicted yield approaches zero. If higher VPD levels driven by global warming materialize in conjunction with rising sea levels or salinity incursion in groundwater, this interaction becomes an important and necessary predictor of expected yield losses and global food security. PMID:25379616

  11. Chain Assemblies from Nanoparticles Synthesized by Atmospheric Pressure Plasma Enhanced Chemical Vapor Deposition: The Computational View.

    PubMed

    Mishin, Maxim V; Zamotin, Kirill Y; Protopopova, Vera S; Alexandrov, Sergey E

    2015-12-01

    This article refers to the computational study of nanoparticle self-organization on the solid-state substrate surface with consideration of the experimental results, when nanoparticles were synthesised during atmospheric pressure plasma enhanced chemical vapor deposition (AP-PECVD). The experimental study of silicon dioxide nanoparticle synthesis by AP-PECVD demonstrated that all deposit volume consists of tangled chains of nanoparticles. In certain cases, micron-sized fractals are formed from tangled chains due to deposit rearrangement. This work is focused on the study of tangled chain formation only. In order to reveal their formation mechanism, a physico-mathematical model was developed. The suggested model was based on the motion equation solution for charged and neutral nanoparticles in the potential fields with the use of the empirical interaction potentials. In addition, the computational simulation was carried out based on the suggested model. As a result, the influence of such experimental parameters as deposition duration, particle charge, gas flow velocity, and angle of gas flow was found. It was demonstrated that electrical charges carried by nanoparticles from the discharge area are not responsible for the formation of tangled chains from nanoparticles, whereas nanoparticle kinetic energy plays a crucial role in deposit morphology and density. The computational results were consistent with experimental results. PMID:26682441

  12. Effect of Chemical Composition on Enthalpy of Evaporation and Equilibrium Vapor Pressure

    E-print Network

    Vladimir Kh. Dobruskin

    2010-04-20

    Proceeding from the Clausius-Clapeyron equation, the relation is derived that establishes a correlation between the partial enthalpy of evaporation from binary solutions, concentrations of components, and equilibrium vapor pressures. The difference between enthalpies of evaporation of components from solutions and those from the pure liquids, D(DH), depends on the chemical nature and concentrations, X, of solutions. The effect of concentrations on D(DH) makes different appearances in ideal and non-ideal solutions, although, as a whole, D(DH) increases with the growth of concentration of the second component. A model is introduced, which considers D(DH) as the sum of energetic changes of three sequential stages: passage of molecules from the bulk liquid into the surface layer, exit of the molecules on the outer side of the interface, and the following desorption into the gas phase. In the framework of the model, the main contribution to enthalpy of evaporation comes from the processes in the surface layer. It is suggested that adsorption from solutions, which changes the chemical composition of the surface layer with respect to that of the bulk solution, determines, to great extent, the difference in the forms of the curves D(DH)=f(X) for ideal and non-ideal solutions.

  13. Low-temperature-grown continuous graphene films from benzene by chemical vapor deposition at ambient pressure.

    PubMed

    Jang, Jisu; Son, Myungwoo; Chung, Sunki; Kim, Kihyeun; Cho, Chunhum; Lee, Byoung Hun; Ham, Moon-Ho

    2015-01-01

    There is significant interest in synthesizing large-area graphene films at low temperatures by chemical vapor deposition (CVD) for nanoelectronic and flexible device applications. However, to date, low-temperature CVD methods have suffered from lower surface coverage because micro-sized graphene flakes are produced. Here, we demonstrate a modified CVD technique for the production of large-area, continuous monolayer graphene films from benzene on Cu at 100-300?°C at ambient pressure. In this method, we extended the graphene growth step in the absence of residual oxidizing species by introducing pumping and purging cycles prior to growth. This led to continuous monolayer graphene films with full surface coverage and excellent quality, which were comparable to those achieved with high-temperature CVD; for example, the surface coverage, transmittance, and carrier mobilities of the graphene grown at 300?°C were 100%, 97.6%, and 1,900-2,500?cm(2) V(-1) s(-1), respectively. In addition, the growth temperature was substantially reduced to as low as 100?°C, which is the lowest temperature reported to date for pristine graphene produced by CVD. Our modified CVD method is expected to allow the direct growth of graphene in device manufacturing processes for practical applications while keeping underlying devices intact. PMID:26658923

  14. Atmospheric Pressure Spray Chemical Vapor Deposited CuInS2 Thin Films for Photovoltaic Applications

    NASA Technical Reports Server (NTRS)

    Harris, J. D.; Raffaelle, R. P.; Banger, K. K.; Smith, M. A.; Scheiman, D. A.; Hepp, A. F.

    2002-01-01

    Solar cells have been prepared using atmospheric pressure spray chemical vapor deposited CuInS2 absorbers. The CuInS2 films were deposited at 390 C using the single source precursor (PPh3)2CuIn(SEt)4 in an argon atmosphere. The absorber ranges in thickness from 0.75 - 1.0 micrometers, and exhibits a crystallographic gradient, with the leading edge having a (220) preferred orientation and the trailing edge having a (112) orientation. Schottky diodes prepared by thermal evaporation of aluminum contacts on to the CuInS2 yielded diodes for films that were annealed at 600 C. Solar cells were prepared using annealed films and had the (top down) composition of Al/ZnO/CdS/CuInS2/Mo/Glass. The Jsc, Voc, FF and (eta) were 6.46 mA per square centimeter, 307 mV, 24% and 0.35%, respectively for the best small area cells under simulated AM0 illumination.

  15. Low-temperature-grown continuous graphene films from benzene by chemical vapor deposition at ambient pressure

    PubMed Central

    Jang, Jisu; Son, Myungwoo; Chung, Sunki; Kim, Kihyeun; Cho, Chunhum; Lee, Byoung Hun; Ham, Moon-Ho

    2015-01-01

    There is significant interest in synthesizing large-area graphene films at low temperatures by chemical vapor deposition (CVD) for nanoelectronic and flexible device applications. However, to date, low-temperature CVD methods have suffered from lower surface coverage because micro-sized graphene flakes are produced. Here, we demonstrate a modified CVD technique for the production of large-area, continuous monolayer graphene films from benzene on Cu at 100–300?°C at ambient pressure. In this method, we extended the graphene growth step in the absence of residual oxidizing species by introducing pumping and purging cycles prior to growth. This led to continuous monolayer graphene films with full surface coverage and excellent quality, which were comparable to those achieved with high-temperature CVD; for example, the surface coverage, transmittance, and carrier mobilities of the graphene grown at 300?°C were 100%, 97.6%, and 1,900–2,500?cm2 V?1 s?1, respectively. In addition, the growth temperature was substantially reduced to as low as 100?°C, which is the lowest temperature reported to date for pristine graphene produced by CVD. Our modified CVD method is expected to allow the direct growth of graphene in device manufacturing processes for practical applications while keeping underlying devices intact. PMID:26658923

  16. Beer Law Constants and Vapor Pressures of HgI2 over HgI2(s,l)

    NASA Technical Reports Server (NTRS)

    Su, Ching-Hua; Zhu, Shen; Ramachandran, N.; Burger, A.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    The optical absorption spectra of the vapor phase over HgI2(s,l) were measured for wavelengths between 200 and 600 nm. The spectra show that the sample sublimed congruently into HgI2 with no Hg or I2 absorption spectrum observed. The Beer's Law constants for 15 wavelengths between 200 and 440 nm were determined. From these constants the vapor pressure of H912, P, was established as a function of temperatures for the liquid and the solid Beta-phases. The expressions correspond to the enthalpies of vaporization and sublimation of 15.30 and 20.17 Kcal/mole, respectively, for the liquid and the Beta-phase HgI2. The difference in the enthalpies gives an enthalpy of fusion of 4.87 Kcal/mole and the intersection of the two expressions gives a melting point of 537 K.

  17. Exchange of Na+ and K+ between water vapor and feldspar phases at high temperature and low vapor pressure

    USGS Publications Warehouse

    Fournier, R.O.

    1976-01-01

    In order to determine whether gas (steam) containing a small amount of dissolved alkali chloride is effective in promoting base exchange of Na+ and K+ among alkali feldspars and coexisting brine or brine plus solid salt, experiments were carried out at 400-700??C and steam densities ranging down to less than 0.05. For bulk compositions rich in potassium, the low pressure results are close to previous high-pressure results in composition of the fluid and coexisting solid phase. However, when the bulk composition is more sodic, alkali feldspars are relatively richer in potassium at low pressure than at high pressure. This behaviour corresponds to enrichment of potassium in the gas phase relative to coexisting brine and precipitation of solid NaCl when the brine plus gas composition becomes moderately sodic. The gas phase is very effective in promoting base exchange between coexisting alkali feldspars at high temperature and low water pressure. This suggests that those igneous rocks which contain coexisting alkali feldspars out of chemical equilibrium either remained very dry during the high-temperature part of their cooling history or that the pore fluid was a gas containing very little potassium relative to sodium. ?? 1976.

  18. Saturated fluorescence measurements of the hydroxyl radical in laminar high-pressure C2H6/O2/N2 flames

    NASA Technical Reports Server (NTRS)

    Carter, Campbell D.; King, Galen B.; Laurendeau, Normand M.

    1992-01-01

    Saturation of a transition of the OH molecule in high-pressure flames is demonstrated by obtaining saturation curves in C2H6/O2/N2 laminar flames at 1, 6.1, 9.2, and 12.3 atm. Quantitative fluorescence measurements of OH number density at pressures to 12.3 atm are presented. To assess the efficacy of the balanced cross-rate model for high-pressure flames, laser-saturated fluorescence measurements, which were calibrated in an atmospheric-pressure flame, are compared with absorption measurements at 3.1 and 6.1 atm. At 3.1 atm the absorption and fluorescence measurements compare well. At 6.1 atm, however, the concentrations given by lasre-saturated fluorescence are about 25 percent lower than the absorption values, indicating some depletion of the laser-coupled levels beyond that at atmospheric pressure. By using a reasonable estimate for the finite sensitivity to quenching, it is anticipated that fluorescence measurements that are calibrated at 1 atm can be applied to flames at about 10 atm with absolute errors within +/- 50 percent.

  19. Numerical study of two-phase flows in porous media : extraction of a capillary pressure saturation curve free from boundary effects

    NASA Astrophysics Data System (ADS)

    Fiorentino, Eve-Agnès; Moura, Marcel; Jørgen Måløy, Knut; Toussaint, Renaud; Schäfer, Gerhard

    2015-04-01

    The capillary pressure saturation relationship is a key element in the resolution of hydrological problems that involve the closure partial-flow Darcy relations. This relationship is derived empirically, and the two typical curve fitting equations that are used to describe it are the Brooks-Corey and Van Genüchten models. The question we tackle is the influence of the boundary conditions of the experimental set-up on the measurement of this retention curve, resulting in a non physical pressure-saturation curve in porous media, due the "end effects" phenomenon. In this study we analyze the drainage of a two-phase flow from a quasi 2D random porous medium, and compare it to simulations arising from an invasion percolation algorithm. The medium is initially saturated with a viscous fluid, and as the pressure difference is gradually increased, air penetrates from an open inlet, thus displacing the fluid which leaves the system from the outlet in the opposing side. In the initial stage, the liquid-air interface evolves from a planar front to the fractal structure characteristic of slow drainage processes, giving the initial downward curvature. In the final stage, air spreads all along the filter, and must reach narrower pores, calling for an increase of the pressure difference, reflected by the final upward curvature. Measuring the pressure-saturation (P-S) law in subwindows located at the inlet, outlet and middle of the network, we emphasize that these boundary effects are the fact of a fraction of pores that is likely to be negligible for high scale systems. We analyze the value of the air saturation at the end of the experiment for a series of simulations with different sample geometries : we observe that this saturation converges to a plateau when the distance between the inlet ant outlet increases, and that the value of this plateau is determined by the distance between the lateral walls. We finally show that the pressure difference between the two phases converges to a value determined by the cumulative density function of the capillary pressures distribution, until the filter is reached, triggering the upward curvature of the curve. The boundary effects bring unphysical features to the P-S curve, that may be present in the results of widely used core sample tests. Far from the boundaries, the relationship between pressure and saturation shows a flat profile dominated by a unique constant determined by the capillary pressure distribution of the medium.

  20. Aqueous solubilities, vapor pressures, and 1-octanol-water partition coefficients for C9-C14 linear alkylbenzenes

    USGS Publications Warehouse

    Sherblom, P.M.; Gschwend, P.M.; Eganhouse, R.P.

    1992-01-01

    Measurements and estimates of aqueous solubilities, 1-octanol-water partition coefficients (Kow), and vapor pressures were made for 29 linear alkylbenzenes having alkyl chain lengths of 9-14 carbons. The ranges of values observed were vapor pressures from 0.002 to 0.418 Pa, log Kow, from 6.83 to 9.95, and aqueous solubilities from 4 to 38 nmol??L-1. Measured values exhibited a relationship to both the alkyl chain length and the position of phenyl substitution on the alkyl chain. Measurement of the aqueous concentrations resulting from equilibration of a mixture of alkylbenzenes yielded higher than expected values, indicating cosolute or other interactive effects caused enhanced aqueous concentrations of these compounds. ?? 1992 American Chemical Society.