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Sample records for solvent vapor pressure

  1. Modeling vapor pressures of solvent systems with and without a salt effect: An extension of the LSER approach

    International Nuclear Information System (INIS)

    Senol, Aynur

    2015-01-01

    Highlights: • A new polynomial vapor pressure approach for pure solvents is presented. • Solvation models reproduce the vapor pressure data within a 4% mean error. • A concentration-basis vapor pressure model is also implemented on relevant systems. • The reliability of existing models was analyzed using log-ratio objective function. - Abstract: A new polynomial vapor pressure approach for pure solvents is presented. The model is incorporated into the LSER (linear solvation energy relation) based solvation model framework and checked for consistency in reproducing experimental vapor pressures of salt-containing solvent systems. The developed two structural forms of the generalized solvation model (Senol, 2013) provide a relatively accurate description of the salting effect on vapor pressure of (solvent + salt) systems. The equilibrium data spanning vapor pressures of eighteen (solvent + salt) and three (solvent (1) + solvent (2) + salt) systems have been subjected to establish the basis for the model reliability analysis using a log-ratio objective function. The examined vapor pressure relations reproduce the observed performance relatively accurately, yielding the overall design factors of 1.084, 1.091 and 1.052 for the integrated property-basis solvation model (USMIP), reduced property-basis solvation model and concentration-dependent model, respectively. Both the integrated property-basis and reduced property-basis solvation models were able to simulate satisfactorily the vapor pressure data of a binary solvent mixture involving a salt, yielding an overall mean error of 5.2%

  2. Solvent-vapor-assisted imprint lithography

    NARCIS (Netherlands)

    Voicu, Nicoleta E.; Ludwigs, Sabine; Crossland, Edward J. W.; Andrew, Piers; Steiner, Ullrich

    2007-01-01

    Sub-micrometer features are replicated into high-molecular-weight polymer resists by using solvent-assisted nanoimprint lithography (see figure). By swelling the polymer in a controlled solvent-vapor atmosphere, millibar pressures and ambient temperatures are sufficient to achieve high-fidelity

  3. Fuel vapor pressure (FVAPRS)

    International Nuclear Information System (INIS)

    Mason, R.E.

    1979-04-01

    A subcode (FVAPRS) is described which calculates fuel vapor pressure. This subcode was developed as part of the fuel rod behavior modeling task performed at EG and G Idaho, Inc. The fuel vapor pressure subcode (FVAPRS), is presented and a discussion of literature data, steady state and transient fuel vapor pressure equations and estimates of the standard error of estimate to be expected with the FVAPRS subcode are included

  4. Ionic association and solvation of the ionic liquid 1-hexyl-3-methylimidazolium chloride in molecular solvents revealed by vapor pressure osmometry, conductometry, volumetry, and acoustic measurements.

    Science.gov (United States)

    Sadeghi, Rahmat; Ebrahimi, Nosaibah

    2011-11-17

    A systematic study of osmotic coefficient, conductivity, volumetric and acoustic properties of solutions of ionic liquid 1-hexyl-3-methylimidazolium chloride ([C(6)mim][Cl]) in various molecular solvents has been made at different temperatures in order to study of ionic association and solvation behavior of [C(6)mim][Cl] in different solutions. Precise measurements on electrical conductances of solutions of [C(6)mim][Cl] in water, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and acetonitrile at 293.15, 298.15, and 303.15 K are reported and analyzed with Barthel's low-concentration chemical model (lcCM) to obtain the limiting molar conductivities and association constants of this ionic liquid in the investigated solvents. Strong ion pairing was found for the ionic liquid in 2-propanol, 1-butanol, and 1-propanol, whereas ion association in acetonitrile, methanol and ethanol is rather weak and in water the ionic liquid is fully dissociated. In the second part of this work, the apparent molar volumes and isentropic compressibilities of [C(6)mim][Cl] in water, methanol, ethanol, acetonitrile, 1-propanol, 2-propanol, and 1-butanol are obtained at the 288.15-313.15 K temperature range at 5 K intervals at atmospheric pressure from the precise measurements of density and sound velocity. The infinite dilution apparent molar volume and isentropic compressibility values of the free ions and ion pairs of [C(6)mim][Cl] in the investigated solvents as well as the excess molar volume of the investigated solutions are determined and their variations with temperature and type of solvents are also studied. Finally, the experimental measurements of osmotic coefficient at 318.15 K for binary solutions of [C(6)mim][Cl] in water, methanol, ethanol, 2-propanol, and acetonitrile are taken using the vapor pressure osmometry (VPO) method and from which the values of the solvent activity, vapor pressure, activity coefficients, and Gibbs free energies are calculated. The results are

  5. Gasoline Reid Vapor Pressure

    Science.gov (United States)

    EPA regulates the vapor pressure of gasoline sold at retail stations during the summer ozone season to reduce evaporative emissions from gasoline that contribute to ground-level ozone and diminish the effects of ozone-related health problems.

  6. Distribution of multi-component solvents in solvent vapor extraction chamber

    Energy Technology Data Exchange (ETDEWEB)

    Das, S. [Society of Petroleum Engineers, Richardson, TX (United States)]|[Marathon Oil Corp., Houston, TX (United States)

    2008-10-15

    Vapex process performance is sensitive to operating pressures, temperatures and the types of solvent used. The hydrocarbon solvents used in Vapex processes typically have between 5 and 10 per cent hydrocarbon impurities, and the accumulation of dense phases inside the vapor chamber reduces gravity drainage potential. This study investigated the partitioning of solvent compounds inside the vapor chamber during in situ Vapex processes.The aim of the study was to examine how the different components of the mixed solvent partitioned inside the extracted chamber during the oil and vapor phase. A 2-D homogenous reservoir model was used to simulate the Vapex process with a solvent mixture comprised of propane and methane at various percentages. The effect of injecting a hot solvent vapor was also investigated. The study showed that injected methane accumulated at both the top and the extraction interface. Accumulations near the top had a positive impact on solvent confinement in thin reservoirs. Diffusion of the solvent component was controlled by gas phase molecular diffusion, and was much faster than the diffusion of solvent molecules in the liquid phase. The use of hot solvent mixtures slowed the extraction process due to lower solvent solubility in the oil phase. It was concluded that the negative impact on viscosity reduction by dilution was not compensated by rises in temperature. 6 refs., 11 figs.

  7. Vapor Pressures of Several Commercially Used Alkanolamines

    NARCIS (Netherlands)

    Klepacova, Katarina; Huttenhuis, Patrick J. G.; Derks, Peter W. J.; Versteeg, Geert F.; Klepáčová, Katarína

    For the design of acid gas treating processes, vapor-liquid equilibrium (VLE) data must be available of the solvents to be applied. In this study the vapor pressures of seven frequently industrially used alkanolamines (diethanolamine, N-methylethanolamine, N,N-dimethylethanolamine,

  8. Effects of solvent evaporation conditions on solvent vapor annealed cylinder-forming block polymer thin films

    Science.gov (United States)

    Grant, Meagan; Jakubowski, William; Nelson, Gunnar; Drapes, Chloe; Baruth, A.

    Solvent vapor annealing is a less time and energy intensive method compared to thermal annealing, to direct the self-assembly of block polymer thin films. Periodic nanostructures have applications in ultrafiltration, magnetic arrays, or other structures with nanometer dimensions, driving its continued interest. Our goal is to create thin films with hexagonally packed, perpendicular aligned cylinders of poly(lactide) in a poly(styrene) matrix that span the thickness of the film with low anneal times and low defect densities, all with high reproducibility, where the latter is paramount. Through the use of our computer-controlled, pneumatically-actuated, purpose-built solvent vapor annealing chamber, we have the ability to monitor and control vapor pressure, solvent concentration within the film, and solvent evaporation rate with unprecedented precision and reliability. Focusing on evaporation, we report on two previously unexplored areas, chamber pressure during solvent evaporation and the flow rate of purging gas aiding the evaporation. We will report our exhaustive results following atomic force microscopy analysis of films exposed to a wide range of pressures and flow rates. Reliably achieving well-ordered films, while occurring within a large section of this parameter space, was correlated with high-flow evaporation rates and low chamber pressures. These results have significant implications on other methods of solvent annealing, including ``jar'' techniques.

  9. The vapor pressures of explosives

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. A technique to depress desflurane vapor pressure.

    Science.gov (United States)

    Brosnan, Robert J; Pypendop, Bruno H

    2006-09-01

    To determine whether the vapor pressure of desflurane could be decreased by using a solvent to reduce the anesthetic molar fraction in a solution (Raoult's Law). We hypothesized that such an anesthetic mixture could produce anesthesia using a nonprecision vaporizer instead of an agent-specific, electronically controlled, temperature and pressure compensated vaporizer currently required for desflurane administration. One healthy adult female dog. Propylene glycol was used as a solvent for desflurane, and the physical characteristics of this mixture were evaluated at various molar concentrations and temperatures. Using a circle system with a breathing bag attached at the patient end and a mechanical ventilator to simulate respiration, an in-circuit, nonprecision vaporizer containing 40% desflurane and 60% propylene glycol achieved an 11.5% +/- 1.0% circuit desflurane concentration with a 5.2 +/- 0.4 (0 = off, 10 = maximum) vaporizer setting. This experiment was repeated with a dog attached to the breathing circuit under spontaneous ventilation with a fresh gas flow of 0.5 L minute(-1). Anesthesia was maintained for over 2 hours at a mean vaporizer setting of 6.2 +/- 0.4, yielding mean inspired and end-tidal desflurane concentrations of 8.7% +/- 0.5% and 7.9% +/- 0.7%, respectively. Rather than alter physical properties of vaporizers to suit a particular anesthetic agent, this study demonstrates that it is also possible to alter physical properties of anesthetic agents to suit a particular vaporizer. However, propylene glycol may not prove an ideal solvent for desflurane because of its instability in solution and substantial-positive deviation from Raoult's Law.

  11. Vapor pressure measured with inflatable plastic bag

    Science.gov (United States)

    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.

  12. Vapor pressures and enthalpies of vaporization of azides

    International Nuclear Information System (INIS)

    Verevkin, Sergey P.; Emel'yanenko, Vladimir N.; Algarra, Manuel; Manuel Lopez-Romero, J.; Aguiar, Fabio; Enrique Rodriguez-Borges, J.; Esteves da Silva, Joaquim C.G.

    2011-01-01

    Highlights: → We prepared and measured vapor pressures and vaporization enthalpies of 7 azides. → We examined consistency of new and available in the literature data. → Data for geminal azides and azido-alkanes selected for thermochemical calculations. - Abstract: Vapor pressures of some azides have been determined by the transpiration method. The molar enthalpies of vaporization Δ l g H m of these compounds were derived from the temperature dependencies of vapor pressures. The measured data sets were successfully checked for internal consistency by comparison with vaporization enthalpies of similarly structured compounds.

  13. Solvent vapor annealing of an insoluble molecular semiconductor

    KAUST Repository

    Amassian, Aram

    2010-01-01

    Solvent vapor annealing has been proposed as a low-cost, highly versatile, and room-temperature alternative to thermal annealing of organic semiconductors and devices. In this article, we investigate the solvent vapor annealing process of a model insoluble molecular semiconductor thin film - pentacene on SiO 2 exposed to acetone vapor - using a combination of optical reflectance and two-dimensional grazing incidence X-ray diffraction measurements performed in situ, during processing. These measurements provide valuable and new insight into the solvent vapor annealing process; they demonstrate that solvent molecules interact mainly with the surface of the film to induce a solid-solid transition without noticeable swelling, dissolving or melting of the molecular material. © 2010 The Royal Society of Chemistry.

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

    Science.gov (United States)

    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…

  15. Estimated vapor pressure for WTP process streams

    Energy Technology Data Exchange (ETDEWEB)

    Pike, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Poirier, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-01-01

    Design assumptions during the vacuum refill phase of the Pulsed Jet Mixers (PJMs) in the Hanford Waste Treatment and Immobilization Plant (WTP) equate the vapor pressure of all process streams to that of water when calculating the temperature at which the vacuum refill is reduced or eliminated. WTP design authority asked the authors to assess this assumption by performing calculations on proposed feed slurries to calculate the vapor pressure as a function of temperature. The vapor pressure was estimated for each WTP waste group. The vapor pressure suppression caused by dissolved solids is much greater than the increase caused by organic components such that the vapor pressure for all of the waste group compositions is less than that of pure water. The vapor pressure for each group at 145°F ranges from 81% to 98% of the vapor pressure of water. If desired, the PJM could be operated at higher temperatures for waste groups with high dissolved solids that suppress vapor pressure. The SO4 group with the highest vapor pressure suppression could be operated up to 153°F before reaching the same vapor pressure of water at 145°F. However, most groups would reach equivalent vapor pressure at 147 to 148°F. If any of these waste streams are diluted, the vapor pressure can exceed the vapor pressure of water at mass dilution ratios greater than 10, but the overall effect is less than 0.5%.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  17. Selective metal-vapor deposition on solvent evaporated polymer surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, Koji; Tsujioka, Tsuyoshi, E-mail: tsujioka@cc.osaka-kyoiku.ac.jp

    2015-12-31

    We report a selective metal-vapor deposition phenomenon based on solvent printing and evaporation on polymer surfaces and propose a method to prepare fine metal patterns using maskless vacuum deposition. Evaporation of the solvent molecules from the surface caused large free volumes between surface polymer chains and resulted in high mobility of the chains, enhancing metal-vapor atom desorption from the surface. This phenomenon was applied to prepare metal patterns on the polymer surface using solvent printing and maskless metal vacuum deposition. Metal patterns with high resolution of micron scale were obtained for various metal species and semiconductor polymer substrates including poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] and poly(3-hexylthiophene-2,5-diyl). - Highlights: • Selective metal-vapor deposition using solvent evaporation on polymer was attained. • Metal patterns with high resolution were obtained for various metal species. • This method can be applied to achieve fine metal-electrodes for polymer electronics.

  18. Vapor Pressure Data Analysis and Statistics

    Science.gov (United States)

    2016-12-01

    near 8, 2000, and 200, respectively. The A (or a) value is directly related to vapor pressure and will be greater for high vapor pressure materials...1, (10) where n is the number of data points, Yi is the natural logarithm of the i th experimental vapor pressure value, and Xi is the...VAPOR PRESSURE DATA ANALYSIS AND STATISTICS ECBC-TR-1422 Ann Brozena RESEARCH AND TECHNOLOGY DIRECTORATE

  19. Vapor Pressure of Antimony Triiodide

    Science.gov (United States)

    2017-12-07

    unlimited. iii Contents List of Figures iv 1. Introduction 1 2. Vapor Pressure 1 3. Experiment 3 4. Discussion and Measurements 5 5...SbI3 as a function of temperature ......................... 6 Approved for public release; distribution is unlimited. 1 1. Introduction ...single-crystal thin films of n-type (Bi,Sb)2(Te,Se)3 materials presents new doping challenges because it is a nonequilibrium process. (Bi,Sb)2(Te,Se)3

  20. Vapor pressure and enthalpy of vaporization of linear aliphatic alkanediamines

    International Nuclear Information System (INIS)

    Pozdeev, Vasiliy A.; Verevkin, Sergey P.

    2011-01-01

    Highlights: → We measured vapor pressure of diamines H 2 N-(CH 2 ) n -NH 2 with n = 3 to 12. → Vaporization enthalpies at 298 K were derived. → We examined consistency of new and available in the literature data. → Enthalpies of vaporization show linear dependence on numbers n. → Enthalpies of vaporization correlate linearly with Kovat's indices. - Abstract: Vapor pressures and the molar enthalpies of vaporization of the linear aliphatic alkanediamines H 2 N-(CH 2 ) n -NH 2 with n = (3 to 12) have been determined using the transpiration method. A linear correlation of enthalpies of vaporization (at T = 298.15 K) of the alkanediamines with the number n and with the Kovat's indices has been found, proving the internal consistency of the measured data.

  1. Controlling Vapor Pressure In Hanging-Drop Crystallization

    Science.gov (United States)

    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.

  2. Thermogravimetric measurements of liquid vapor pressure

    International Nuclear Information System (INIS)

    Rong Yunhong; Gregson, Christopher M.; Parker, Alan

    2012-01-01

    Highlights: ► Rapid determination of vapor pressure by TGA. ► Demonstration of limitations of currently available approaches in literature. ► New model for vapor pressure assessment of small size samples in TGA. ► New model accounts for vapor diffusion and sample geometry and measures vapor pressure normally within 10%. - Abstract: A method was developed using thermo-gravimetric analysis (TGA) to determine the vapor pressure of volatile liquids. This is achieved by measuring the rate of evaporation (mass loss) of a pure liquid contained within a cylindrical pan. The influence of factors like sample geometry and vapor diffusion on evaporation rate are discussed. The measurement can be performed across a wide range of temperature yielding reasonable results up to 10 kPa. This approach may be useful as a rapid and automatable method for measuring the volatility of flavor and fragrance raw materials.

  3. 40 CFR 796.1950 - Vapor pressure.

    Science.gov (United States)

    2010-07-01

    ... (CONTINUED) CHEMICAL FATE TESTING GUIDELINES Physical and Chemical Properties § 796.1950 Vapor pressure. (a.... In addition, chemicals that are likely to be gases at ambient temperatures and which have low water... gases until the measured vapor pressure is constant, a process called “degassing.” Impurities more...

  4. Vapor pressure and enthalpy of vaporization of aliphatic propanediamines

    International Nuclear Information System (INIS)

    Verevkin, Sergey P.; Chernyak, Yury

    2012-01-01

    Highlights: ► We measured vapor pressure of four aliphatic 1,3-diamines. ► Vaporization enthalpies at 298 K were derived. ► We examined consistency of new and available data in the literature. ► A group-contribution method for prediction was developed. - Abstract: Vapor pressures of four aliphatic propanediamines including N-methyl-1,3-propanediamine (MPDA), N,N-dimethyl-1,3-propanediamine (DMPDA), N,N-diethyl-1,3-propanediamine (DEPDA) and N,N,N′,N′-tetramethyl-1,3-propanediamine (4MPDA) were measured using the transpiration method. The vapor pressures developed in this work and reported in the literature were used to derive molar enthalpy of vaporization values at the reference temperature 298.15 K. An internal consistency check of the enthalpy of vaporization was performed for the aliphatic propanediamines studied in this work. A group-contribution method was developed for the validation and prediction vaporization enthalpies of amines and diamines.

  5. Improving Liquid Entry Pressure of Polyvinylidene Fluoride (PVDF Membranes by Exploiting the Role of Fabrication Parameters in Vapor-Induced Phase Separation VIPS and Non-Solvent-Induced Phase Separation (NIPS Processes

    Directory of Open Access Journals (Sweden)

    Faisal Abdulla AlMarzooqi

    2017-02-01

    Full Text Available Polyvinylidene fluoride (PVDF is a popular polymer material for making membranes for several applications, including membrane distillation (MD, via the phase inversion process. Non-solvent-induced phase separation (NIPS and vapor-induced phase separation (VIPS are applied to achieve a porous PVDF membrane with low mass-transfer resistance and high contact angle (hydrophobicity. In this work, firstly, the impacts of several preparation parameters on membrane properties using VIPS and NIPS were studied. Then, the performance of the selected membrane was assessed in a lab-scale direct-contact MD (DCMD unit. The parametric study shows that decreasing PVDF concentration while increasing both relative humidity (RH and exposure time increased the contact angle and bubble-point pore size (BP. Those trends were investigated further by varying the casting thickness. At higher casting thicknesses and longer exposure time (up to 7.5 min, contact angle (CA increased but BP significantly decreased. The latter showed a dominant trend leading to liquid entry pressure (LEP increase with thickness.

  6. Vapor pressures and thermophysical properties of selected hexenols and recommended vapor pressure for hexan-1-ol

    Czech Academy of Sciences Publication Activity Database

    Štejfa, V.; Fulem, Michal; Růžička, K.; Matějka, P.

    2015-01-01

    Roč. 402, Sep (2015), 18-29 ISSN 0378-3812 Institutional support: RVO:68378271 Keywords : alcohols * vapor pressure * heat capacity * ideal - gas thermodynamic properties * vaporization enthalpy Subject RIV: BJ - Thermodynamics Impact factor: 1.846, year: 2015

  7. Recommended Vapor Pressure of Solid Naphthalen

    Czech Academy of Sciences Publication Activity Database

    Růžička, K.; Fulem, Michal; Růžička, V.

    2005-01-01

    Roč. 50, - (2005), s. 1956-1970 ISSN 0021-9568 Institutional research plan: CEZ:AV0Z10100521 Keywords : solid naphthalene * vapor pressure * enthalpy of vaporization * enthalpy of fusion Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.610, year: 2005

  8. 40 CFR 52.246 - Control of dry cleaning solvent vapor losses.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control of dry cleaning solvent vapor... cleaning solvent vapor losses. (a) For the purpose of this section, “dry cleaning operation” means that process by which an organic solvent is used in the commercial cleaning of garments and other fabric...

  9. Melting temperature, vapor density, and vapor pressure of molybdenum pentafluoride

    Energy Technology Data Exchange (ETDEWEB)

    Krause, Jr, R F; Douglas, T B [National Bureau of Standards, Washington, D.C. (USA). Inst. for Materials Research

    1977-12-01

    A sample of MoF/sub 5/ was prepared by reaction of MoF/sub 6/(g) and Mo(c). Melting curves of temperature against time established the melting temperature at zero impurity to be 318.85 K, the enthalpy of fusion to be 6.1 kJ mol/sup -1/ (+ - 5 per cent), and the cryoscopic impurity of the sample to be 0.15 mole per cent. In the presence of MoF/sub 6/(g) which was added to suppress disproportionation, the vapor density of MoF/sub 5/ over the liquid was measured by the transpiration method at 343, 363, and 383 K, the total MoF/sub 5/ that evaporated being determined by permanganate titration. The total vapor pressure of MoF/sub 5/ oligomers over the liquid was measured by a simple static method at 373 and 392 K, while melting temperatures were taken alternately to monitor possible contamination of the sample. Although the vapor pressures were adjusted for disproportionation, solution of MoF/sub 6/ in MoF/sub 5/ (1), and wall adsorption of MoF/sub 6/ their percentage uncertainty is probably several times that of the vapor densities. A combination of the two properties indicates the average extent of association of the saturated vapor to be near 2, which is the value for the dimer species (MoF/sub 5/)/sub 2/.

  10. Sorption mechanism of solvent vapors to coals; Sekitan eno yobai joki no shuchaku kiko no kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, K.; Takanohashi, T.; Iino, M. [Tohoku University, Sendai (Japan). Institute for Chemical Reaction Science

    1996-10-28

    With an objective to clarify the interactions between micropore structure of coal and solvent reagents, a sorption experiment was carried out under solvent saturated vapor pressure. Low-volatile bituminous coal, Pocahontas No. 3 coal, has the aromatic ring structure developed, and makes solvent more difficult to diffuse into coal, hence sorption amount is small. Methanol has permeated since its polarity is high. High-volatile bituminous coal, Illinois No. 6 coal, makes solvent penetrate easily, and the sorption amount was large with both of aromatic and polar solvents. Since brown coal, Beulah Zap coal, contains a large amount of oxygen, and hydrogen bonding is predominant, sorption amount of cyclohexane and benzene having no polarity is small. Methanol diffuses while releasing hydrogen bond due to its polarity, and its sorption amount is large. A double sorption model is available, which expresses the whole sorption amount as a sum of physical sorption amount and amount of permeation into coal. This model was applied when it explained successfully the sorption behavior of the solvents relative to coals, excepting some of the systems. However, also observed were such abnormal behavior as sorption impediment due to interactions between coal surface and solvents, and permeation impediment due to hydroxyl groups inside the coals. 1 ref., 10 figs., 2 tabs.

  11. Apparatus to measure vapor pressure, differential vapor pressure, liquid molar volume, and compressibility of liquids and solutions to the critical point. Vapor pressures, molar volumes, and compressibilities of protiobenzene and deuteriobenzene at elevated temperatures

    International Nuclear Information System (INIS)

    Kooner, Z.S.; Van Hook, W.A.

    1986-01-01

    An apparatus designed to measure vapor pressure differences between two similar liquids, such as isotopic isomers, or between a solution and its reference solvent at temperatures and pressures extending to the critical point is described. Vapor-phase volume is minimized and pressure is transmitted to the transducer through the liquid, thereby avoiding several experimental difficulties. Liquid can be injected into the heated part of the system by volumetrically calibrated screw injectors, thus permitting measurements of liquid molar volume, compressibility, and expansivity. The addition of a high-pressure circulating pump and injection valve allows the apparatus to be employed as a continuous dilution differential vapor pressure apparatus for determining partial molar free energies of solution. In the second part of the paper data on the vapor pressure, molar volume, compressibility, and expansivity and their isotope effects for C 6 H 6 and C 6 D 6 from room temperature to near the critical temperature are reported

  12. Evaluation of the Process of Solvent Vapor Annealing on Organic Thin Films

    KAUST Repository

    Ren, Yi

    2011-01-01

    Solvent vapor annealing has recently emerged as an intriguing, room-temperature, and highly versatile alternative to thermal annealing. The chemically selective interaction between solvents and organic semiconductors opens new opportunities

  13. System Model of Heat and Mass Transfer Process for Mobile Solvent Vapor Phase Drying Equipment

    Directory of Open Access Journals (Sweden)

    Shiwei Zhang

    2014-01-01

    Full Text Available The solvent vapor phase drying process is one of the most important processes during the production and maintenance for large oil-immersed power transformer. In this paper, the working principle, system composition, and technological process of mobile solvent vapor phase drying (MVPD equipment for transformer are introduced in detail. On the basis of necessary simplification and assumption for MVPD equipment and process, a heat and mass transfer mathematical model including 40 mathematical equations is established, which represents completely thermodynamics laws of phase change and transport process of solvent, water, and air in MVPD technological processes and describes in detail the quantitative relationship among important physical quantities such as temperature, pressure, and flux in key equipment units and process. Taking a practical field drying process of 500 KV/750 MVA power transformer as an example, the simulation calculation of a complete technological process is carried out by programming with MATLAB software and some relation curves of key process parameters changing with time are obtained such as body temperature, tank pressure, and water yield. The change trend of theoretical simulation results is very consistent with the actual production record data which verifies the correctness of mathematical model established.

  14. Estimating enthalpy of vaporization from vapor pressure using Trouton's rule.

    Science.gov (United States)

    MacLeod, Matthew; Scheringer, Martin; Hungerbühler, Konrad

    2007-04-15

    The enthalpy of vaporization of liquids and subcooled liquids at 298 K (delta H(VAP)) is an important parameter in environmental fate assessments that consider spatial and temporal variability in environmental conditions. It has been shown that delta H(VAP)P for non-hydrogen-bonding substances can be estimated from vapor pressure at 298 K (P(L)) using an empirically derived linear relationship. Here, we demonstrate that the relationship between delta H(VAP)and PL is consistent with Trouton's rule and the ClausiusClapeyron equation under the assumption that delta H(VAP) is linearly dependent on temperature between 298 K and the boiling point temperature. Our interpretation based on Trouton's rule substantiates the empirical relationship between delta H(VAP) degree and P(L) degrees for non-hydrogen-bonding chemicals with subcooled liquid vapor pressures ranging over 15 orders of magnitude. We apply the relationship between delta H(VAP) degrees and P(L) degrees to evaluate data reported in literature reviews for several important classes of semivolatile environmental contaminants, including polycyclic aromatic hydrocarbons, chlorobenzenes, polychlorinated biphenyls and polychlorinated dibenzo-dioxins and -furans and illustrate the temperature dependence of results from a multimedia model presented as a partitioning map. The uncertainty associated with estimating delta H(VAP)degrees from P(L) degrees using this relationship is acceptable for most environmental fate modeling of non-hydrogen-bonding semivolatile organic chemicals.

  15. Vapor pressure and thermodynamics of beryllium carbide

    International Nuclear Information System (INIS)

    Rinehart, G.H.; Behrens, R.G.

    1980-01-01

    The vapor pressure of beryllium carbide has been measured over the temperature range 1388 to 1763 K using Knudsen-effusion mass spectrometry. Vaporization occurs incongruently according to the reaction Be 2 C(s) = 2Be(g) + C(s). The equilibrium vapor pressure above the mixture of Be 2 C and C over the experimental temperature range is (R/J K -1 mol -1 )ln(p/Pa) = -(3.610 +- 0.009) x 10 5 (K/T) + (221.43 +- 1.06). The third-law enthalpy change for the above reaction obtained from the present vapor pressures is ΔH 0 (298.15 K) = (740.5 +- 0.1) kJ mol -1 . The corresponding second-law result is ΔH 0 (298.15 K) = (732.0 +- 1.8) kJ mol -1 . The enthalpy of formation for Be 2 C(s) calculated from the present third-law vaporization enthalpy and the enthalpy of formation of Be(g) is ΔH 0 sub(f)(298.15 K) = -(92.5 +- 15.7) kJ mol -1 . (author)

  16. Enhanced bulk heterojunction devices prepared by thermal and solvent vapor annealing processes

    Science.gov (United States)

    Forrest, Stephen R.; Thompson, Mark E.; Wei, Guodan; Wang, Siyi

    2017-09-19

    A method of preparing a bulk heterojunction organic photovoltaic cell through combinations of thermal and solvent vapor annealing are described. Bulk heterojunction films may prepared by known methods such as spin coating, and then exposed to one or more vaporized solvents and thermally annealed in an effort to enhance the crystalline nature of the photoactive materials.

  17. Vapor pressure of selected organic iodides

    Czech Academy of Sciences Publication Activity Database

    Fulem, M.; Růžička, K.; Morávek, P.; Pangrác, Jiří; Hulicius, Eduard; Kozyrkin, B.; Shatunov, V.

    2010-01-01

    Roč. 55, č. 11 (2010), 4780-4784 ISSN 0021-9568 R&D Projects: GA ČR GA203/08/0217 Institutional research plan: CEZ:AV0Z10100521 Keywords : vapor pressure * static method * organic iodides Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.089, year : 2010

  18. Manipulating the Morphology of P3HT–PCBM Bulk Heterojunction Blends with Solvent Vapor Annealing

    KAUST Repository

    Verploegen, Eric; Miller, Chad E.; Schmidt, Kristin; Bao, Zhenan; Toney, Michael F.

    2012-01-01

    Using grazing incidence X-ray scattering, we observe the effects of solvent vapors upon the morphology of poly(3-hexylthiophene)-phenyl-C 61-butyric acid methyl ester (P3HT-PCBM) bulk heterojunction thin film blends in real time; allowing us to observe morphological rearrangements that occur during this process as a function of solvent. We detail the swelling of the P3HT crystallites upon the introduction of solvent and the resulting changes in the P3HT crystallite morphology. We also demonstrate the ability for tetrahydrofuran vapor to induce crystallinity in PCBM domains. Additionally, we measure the nanoscale phase segregated domain size as a function of solvent vapor annealing and correlate this to the changes observed in the crystallite morphology of each component. Finally, we discuss the implications of the morphological changes induced by solvent vapor annealing on the device properties of BHJ solar cells. © 2012 American Chemical Society.

  19. Manipulating the Morphology of P3HT–PCBM Bulk Heterojunction Blends with Solvent Vapor Annealing

    KAUST Repository

    Verploegen, Eric

    2012-10-23

    Using grazing incidence X-ray scattering, we observe the effects of solvent vapors upon the morphology of poly(3-hexylthiophene)-phenyl-C 61-butyric acid methyl ester (P3HT-PCBM) bulk heterojunction thin film blends in real time; allowing us to observe morphological rearrangements that occur during this process as a function of solvent. We detail the swelling of the P3HT crystallites upon the introduction of solvent and the resulting changes in the P3HT crystallite morphology. We also demonstrate the ability for tetrahydrofuran vapor to induce crystallinity in PCBM domains. Additionally, we measure the nanoscale phase segregated domain size as a function of solvent vapor annealing and correlate this to the changes observed in the crystallite morphology of each component. Finally, we discuss the implications of the morphological changes induced by solvent vapor annealing on the device properties of BHJ solar cells. © 2012 American Chemical Society.

  20. Separation of aromatics by vapor permeation through solvent swollen membrane

    Energy Technology Data Exchange (ETDEWEB)

    Ito, A.; Adachi, K.; Feng, Y. [Niigata University, Niigata (Japan)

    1995-12-20

    A vapor permeation process for aromatics separation from a hydrocarbon mixture was studied by means of the simultaneous permeation of dimethylsulfoxide vapor as an agent for membrane swelling and preferential permeation of aromatics. The separation performance of the process was demonstrated by a polyvinylalcohol membrane for mixed vapors of benzene/cyclohexane, xylene/octane and a model gasoline. The aromatic vapors preferentially permeated from these mixed vapor feeds. The separation factor was over 10. The separation mechanism of the process mainly depends on the relative salability of the vapors between aromatics and other hydrocarbons in dimethylsulfoxide. 14 refs., 9 figs., 1 tab.

  1. Recommended vapor pressures for thiophene, sulfolane, and dimethyl sulfoxide

    Czech Academy of Sciences Publication Activity Database

    Fulem, Michal; Růžička, K.; Růžička, M.

    2011-01-01

    Roč. 303, č. 2 (2011), s. 205-216 ISSN 0378-3812 Institutional research plan: CEZ:AV0Z10100521 Keywords : thiophene sulfolane * dimethyl sulfoxide * vapor pressure * heat capacity * vaporization enthalpy * recommended vapor pressure equation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.139, year: 2011

  2. Enthalpy of vaporization and vapor pressure of whiskey lactone and menthalactone by correlation gas chromatography

    International Nuclear Information System (INIS)

    Simmons, Daniel; Chickos, James

    2017-01-01

    Highlights: • The vapor pressure and vaporization enthalpies of cis and trans-whiskey lactone have been evaluated. • Enthalpies of vaporization and vapor pressures of (+)-isomintlactone and (−)-mintlactone were also evaluated. • The sublimation enthalpy and corresponding vapor pressure of (+) -isomintlactone at T = 298.15 K is estimated. - Abstract: Enthalpies of vaporization at T = 298.15 K of cis and trans-whiskey lactone have been evaluated by correlation gas chromatography to be (68.4 ± 1.7) kJ·mol −1 and (67.5 ± 1.7) kJ·mol −1 , respectively. The enthalpies of vaporization of isomintlactone and mintlactone also evaluated by correlation gas chromatography have been found to have vaporization enthalpies of (74.2 ± 1.8) kJ·mol −1 and (73.2 ± 1.8) kJ·mol −1 respectively. The vapor pressures for cis and trans-whiskey lactone at T = 298.15 K have been evaluated as (1.5 ± 0.09) Pa and (2.0 ± 0.1) Pa using vapor pressures of a series of lactones as standards. Vapor pressures for isomintlactone and mintlactone were evaluated as (0.26 ± 0.012) Pa and (0.33 ± 0.02) Pa, respectively. Fusion and sublimation enthalpies for (+)-isomintlactone as well as the vapor pressure of the solid have been estimated.

  3. Perpendicular Structure Formation of Block Copolymer Thin Films during Thermal Solvent Vapor Annealing : Solvent and Thickness Effects

    NARCIS (Netherlands)

    Yang, Qiuyan; Loos, Katja

    2017-01-01

    Solvent vapor annealing of block copolymer (BCP) thin films can produce a range of interesting morphologies, especially when the perpendicular orientation of micro-domains with respect to the substrate plays a role. This, for instance, allows BCP thin films to serve as useful templates for

  4. The solvent absorption-extractive distillation (SAED) process for ethanol recovery from gas/vapor streams

    Energy Technology Data Exchange (ETDEWEB)

    Dale, M.C.

    1993-12-31

    A low energy system for ethanol recovery and dehydration has been developed. This system utilizes a solvent for (1) absorption of ethanol vapors, and then the same solvent for (2) extractive distillation. The ideal solvent for this process would have a high affinity for ethanol, and no affinity for water. Heavy alcohols such as dodecanol, and tridecanol, some phosphorals, and some fatty acids have been determined to meet the desired specifications. These solvents have the effect of making water more volatile than ethanol. Thus, a water stream is taken off initially in the dehydration column, and a near anhydrous ethanol stream is recovered from the ethanol/solvent stripper column. Thus the solvent serves dual uses (1) absorption media, and (2) dehydration media. The SAED process as conceptualized would use a solvent similar to solvents used for direct extractive separation of ethanol from aqueous ethanol solutions.

  5. Ellipsometry-based combination of isothermal sorption-desorption measurement and temperature programmed desorption technique: A probe for interaction of thin polymer films with solvent vapor

    Science.gov (United States)

    Efremov, Mikhail Yu.; Nealey, Paul F.

    2018-05-01

    An environmental chamber equipped with an in situ spectroscopic ellipsometer, programmatic vapor pressure control, and variable temperature substrate holder has been designed for studying polymer coating behavior during an exposure to a solvent vapor and also for probing the residual solvent in the film afterwards. Both sorption-desorption cycle at a constant temperature and temperature programmed desorption (TPD) of the residual solvent manifest themselves as a change of the film thickness. Monitoring of ellipsometric angles of the coating allows us to determine the thickness as a function of the vapor pressure or sample temperature. The solvent vapor pressure is precisely regulated by a computer-controlled pneumatics. TPD spectra are recorded during heating of the film in an oil-free vacuum. The vapor pressure control system is described in detail. The system has been tested on 6-170 nm thick polystyrene, poly(methyl methacrylate), and poly(2-vinyl pyridine) films deposited on silicon substrates. Liquid toluene, water, ethanol, isopropanol, cyclohexane, 1,2-dichloroethane, and chlorobenzene were used to create a vapor atmosphere. Typical sorption-desorption and TPD curves are shown. The instrument achieves sub-monolayer sensitivity for adsorption studies on flat surfaces. Polymer-solvent vapor systems with strong interaction demonstrate characteristic absorption-desorption hysteresis spanning from vacuum to the glass transition pressure. Features on the TPD curves can be classified as either glass transition related film contraction or low temperature broad contraction peak. Typical absorption-desorption and TPD dependencies recorded for the 6 nm thick polystyrene film demonstrate the possibility to apply the presented technique for probing size effects in extremely thin coatings.

  6. Method of estimating changes in vapor concentrations continuously generated from two-component organic solvents.

    Science.gov (United States)

    Hori, Hajime; Ishidao, Toru; Ishimatsu, Sumiyo

    2010-12-01

    We measured vapor concentrations continuously evaporated from two-component organic solvents in a reservoir and proposed a method to estimate and predict the evaporation rate or generated vapor concentrations. Two kinds of organic solvents were put into a small reservoir made of glass (3 cm in diameter and 3 cm high) that was installed in a cylindrical glass vessel (10 cm in diameter and 15 cm high). Air was introduced into the glass vessel at a flow rate of 150 ml/min, and the generated vapor concentrations were intermittently monitored for up to 5 hours with a gas chromatograph equipped with a flame ionization detector. The solvent systems tested in this study were the methanoltoluene system and the ethyl acetate-toluene system. The vapor concentrations of the more volatile component, that is, methanol in the methanol-toluene system and ethyl acetate in the ethyl acetate-toluene system, were high at first, and then decreased with time. On the other hand, the concentrations of the less volatile component were low at first, and then increased with time. A model for estimating multicomponent organic vapor concentrations was developed, based on a theory of vapor-liquid equilibria and a theory of the mass transfer rate, and estimated values were compared with experimental ones. The estimated vapor concentrations were in relatively good agreement with the experimental ones. The results suggest that changes in concentrations of two-component organic vapors continuously evaporating from a liquid reservoir can be estimated by the proposed model.

  7. Excessively High Vapor Pressure of Al-based Amorphous Alloys

    Directory of Open Access Journals (Sweden)

    Jae Im Jeong

    2015-10-01

    Full Text Available Aluminum-based amorphous alloys exhibited an abnormally high vapor pressure at their approximate glass transition temperatures. The vapor pressure was confirmed by the formation of Al nanocrystallites from condensation, which was attributed to weight loss of the amorphous alloys. The amount of weight loss varied with the amorphous alloy compositions and was inversely proportional to their glass-forming ability. The vapor pressure of the amorphous alloys around 573 K was close to the vapor pressure of crystalline Al near its melting temperature, 873 K. Our results strongly suggest the possibility of fabricating nanocrystallites or thin films by evaporation at low temperatures.

  8. Plasma-polymerized films providing selective affinity to the polarity of vaporized organic solvents

    International Nuclear Information System (INIS)

    Akimoto, Takuo; Ikeshita, Yusuke; Terashima, Ryo; Karube, Isao

    2009-01-01

    Plasma-polymerized films (PPFs) were fabricated as recognition membranes for a vapor-sensing device, and their affinity to vaporized organic solvents was evaluated with surface plasmon resonance. The affinity we intended to create is the selective sorption of the vaporized organic solvents depending on their polarity. For this purpose, acetonitrile, ethylenediamine (EDA), styrene, hexamethyldisiloxane (HMDSO), and hexamethyldisilazane were used to fabricate PPFs. Vaporized methanol, ethanol, and 1-propanol were used as high-polar solvents to be analyzed. Hexane, toluene, and p-xylene were used as low-polar solvents. As a result, the HMDSO-PPF with 97.3 o of contact angle was found to provide affinity to the low-polar solvents. In contrast, the EDA-PPF with 7.1 o of contact angle provided affinity to the high-polar solvents. Observations of the surface morphology of the HMDSO- and EDA-PPFs with a scanning electron microscope revealed that they are composed of nano-scale islands.

  9. Building blocks for ionic liquids: Vapor pressures and vaporization enthalpies of 1-(n-alkyl)-imidazoles

    International Nuclear Information System (INIS)

    Emel'yanenko, Vladimir N.; Portnova, Svetlana V.; Verevkin, Sergey P.; Skrzypczak, Andrzej; Schubert, Thomas

    2011-01-01

    Highlights: → We measured vapor pressures of the 1-(n-alkyl)-imidazoles by transpiration method. → Variations on the alkyl chain length n were C 3 , C 5 -C 7 , and C 9 -C 10 . → Enthalpies of vaporization were derived from (p, T) dependencies. → Enthalpies of vaporization at 298.15 K were linear dependent on the chain length. - Abstract: Vapor pressures of the linear 1-(n-alkyl)-imidazoles with the alkyl chain C 3 , C 5 -C 7 , and C 9 -C 10 have been measured by the transpiration method. The molar enthalpies of vaporization Δ l g H m of these compounds were derived from the temperature dependencies of vapor pressures. A linear correlation of enthalpies of vaporization Δ l g H m (298.15 K) of the 1-(n-alkyl)-imidazoles with the chain length has been found.

  10. Recommended vapor pressure and thermophysical data for ferrocene

    Czech Academy of Sciences Publication Activity Database

    Fulem, Michal; Růžička, K.; Červinka, C.; Rocha, M.A.A.; Santos, L.M.N.B.F.; Berg, R.F.

    2013-01-01

    Roč. 57, FEB (2013), 530-540 ISSN 0021-9614 Institutional support: RVO:68378271 Keywords : ferrocene * vapor pressure * heat capacity * ideal gas thermodynamic properties * sublimation enthalpy * recommended vapor pressure equation Subject RIV: BJ - Thermodynamics Impact factor: 2.423, year: 2013

  11. Lamellar Diblock Copolymer Thin Films during Solvent Vapor Annealing Studied by GISAXS

    DEFF Research Database (Denmark)

    Zhang, Jianqi; Posselt, Dorthe; Smilgies, Detlef-M.

    2014-01-01

    The reorientation of lamellae and the dependence of the lamellar spacing, Dlam, on polymer volume fraction, ϕP, Dlam ∝ ϕP–β, in diblock copolymer thin films during solvent vapor annealing (SVA) are examined by combining white light interferometry (WLI) and grazing-incidence small-angle X-ray scat......The reorientation of lamellae and the dependence of the lamellar spacing, Dlam, on polymer volume fraction, ϕP, Dlam ∝ ϕP–β, in diblock copolymer thin films during solvent vapor annealing (SVA) are examined by combining white light interferometry (WLI) and grazing-incidence small-angle X...

  12. Preparation of membranes using solvent-less vapor deposition followed by in-situ polymerization

    Science.gov (United States)

    O'Brien, Kevin C [San Ramon, CA; Letts, Stephan A [San Ramon, CA; Spadaccini, Christopher M [Oakland, CA; Morse, Jeffrey C [Pleasant Hill, CA; Buckley, Steven R [Modesto, CA; Fischer, Larry E [Los Gatos, CA; Wilson, Keith B [San Ramon, CA

    2010-07-13

    A system of fabricating a composite membrane from a membrane substrate using solvent-less vapor deposition followed by in-situ polymerization. A first monomer and a second monomer are directed into a mixing chamber in a deposition chamber. The first monomer and the second monomer are mixed in the mixing chamber providing a mixed first monomer and second monomer. The mixed first monomer and second monomer are solvent-less vapor deposited onto the membrane substrate in the deposition chamber. The membrane substrate and the mixed first monomer and second monomer are heated to produce in-situ polymerization and provide the composite membrane.

  13. Vapor pressure and enthalpy of vaporization of oil of catnip by correlation gas chromatography

    International Nuclear Information System (INIS)

    Simmons, Daniel; Gobble, Chase; Chickos, James

    2016-01-01

    Highlights: • Vaporization enthalpies of the nepetalactones from oil of catnip have been evaluated. • Vapor pressures from T = (298.15 to 350) K have been evaluated. • Oil of catnip has a vapor pressure similar to DEET at T = 298.15 K. - Abstract: The vaporization enthalpy and vapor pressure of the two nepetalactones found in Nepeta cataria have been evaluated by correlation gas chromatography. Vaporization enthalpies at T = 298.15 K of {(68.0 ± 1.9) and (69.4 ± 1.9)} kJ ⋅ mol"−"1 have been derived for the minor diastereomer, (4aS,7S,7aS)-nepetalactone, and major one, (4aS,7S,7aR)-nepetalactone, respectively. Vapor pressures also at T = 298.15 K of p = (1.2 ± 0.04) Pa and (0.91 ± 0.03) Pa have been evaluated for the minor and the major stereoisomer. In addition to being of interest because of the remarkable effect it has on various felids, oil of catnip is also quite effective in repelling mosquitoes, comparable to diethyl-m-toluamide (DEET). The vapor pressures evaluated in this work suggest that the two stereoisomers have similar volatility to DEET at ambient temperatures.

  14. Vapor pressures and vaporization enthalpy of codlemone by correlation gas chromatography

    International Nuclear Information System (INIS)

    Schultz, Shannon M.; Harris, Harold H.; Chickos, James S.

    2015-01-01

    Highlights: • The vaporization enthalpy of codlemone has been evaluated. • The vapor pressure of codlemone has been evaluated from T = (298.15 to T b ) K. • Vapor pressures for the 1-alkanols standards are available from T = (298.15 to 500) K. - Abstract: The vapor pressure and vaporization enthalpy of codlemone (trans, trans 8,10-dodecadien-1-ol), the female sex hormone of the codling moth is evaluated by correlation gas chromatography using a series of saturated primary alcohols as standards. A vaporization enthalpy of (92.3 ± 2.6) kJ · mol −1 and a vapor pressure, p/Pa = (0.083 ± 0.012) were evaluated at T = 298.15 K. An equation for the evaluation of vapor pressure from ambient temperature to boiling has been derived by correlation for codlemone. The calculated boiling temperature of T B = 389 K at p = 267 Pa is within the temperature range reported in the literature. A normal boiling temperature of T B = (549.1 ± 0.1) K is also estimated by extrapolation

  15. Perpendicular Structure Formation of Block Copolymer Thin Films during Thermal Solvent Vapor Annealing: Solvent and Thickness Effects

    Directory of Open Access Journals (Sweden)

    Qiuyan Yang

    2017-10-01

    Full Text Available Solvent vapor annealing of block copolymer (BCP thin films can produce a range of interesting morphologies, especially when the perpendicular orientation of micro-domains with respect to the substrate plays a role. This, for instance, allows BCP thin films to serve as useful templates for nanolithography and hybrid materials preparation. However, precise control of the arising morphologies is essential, but in most cases difficult to achieve. In this work, we investigated the solvent and thickness effects on the morphology of poly(styrene-b-2 vinyl pyridine (PS-b-P2VP thin films with a film thickness range from 0.4 L0 up to 0.8 L0. Ordered perpendicular structures were achieved. One of the main merits of our work is that the phase behavior of the ultra-high molecular weight BCP thin films, which hold a 100-nm sized domain distance, can be easily monitored via current available techniques, such as scanning electron microscope (SEM, atomic force microscope (AFM, and transmission electron microscope (TEM. Systematic monitoring of the self-assembly behavior during solvent vapor annealing can thus provide an experimental guideline for the optimization of processing conditions of related BCP films systems.

  16. Vapor solvent decontamination of PCB [polychlorinated biphenyls] transformer components

    International Nuclear Information System (INIS)

    Green, G.R.; Green, G.R.

    1992-01-01

    A process is provided to recover reclaimable material from discarded transformers containing PCB (polychlorinated biphenyl) insulating oils and to minimize the volume of materials which are subject to environmental regulation upon disposal. According to the invention, the transformer is drained and given an initial cleaning. The internal parts are removed and cleaned a second time as is the empty transformer casing. Recoverable materials such as aluminum and copper are cleaned to less than 10 μg of PCB per 100 cm 2 , allowing these materials to be recycled rather than buried. Almost all of the remaining nonmetallic materials are combustible solids or liquids which can be destroyed by incineration. The cleaning is accomplished using trichloroethylene solvent, chosen for its low boiling point which makes it easy to recycle using an isothermal separator. The removed transformer parts are cleaned in a secondary cleaning station consisting of 3 separate sections including tumbling baskets. 2 figs

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

    Science.gov (United States)

    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)

  18. Vapor pressures and enthalpies of vaporization of a series of the linear aliphatic aldehydes

    Czech Academy of Sciences Publication Activity Database

    Verevkin, S. P.; Krasnykh, E. L.; Vasiltsova, T. V.; Koutek, Bohumír; Doubský, Jan; Heintz, A.

    2003-01-01

    Roč. 206, - (2003), s. 331-339 ISSN 0378-3812 Institutional research plan: CEZ:AV0Z4055905 Keywords : aldehydes * vapor pressure * enthalpy of vaporization Subject RIV: CC - Organic Chemistry Impact factor: 1.165, year: 2003

  19. Vapor pressures of dimethylcadmium, trimethylbismuth, and tris(dimethylamino)antimony

    Czech Academy of Sciences Publication Activity Database

    Morávek, Pavel; Fulem, Michal; Pangrác, Jiří; Hulicius, Eduard; Růžička, K.

    2013-01-01

    Roč. 360, Dec (2013), s. 106-110 ISSN 0378-3812 R&D Projects: GA ČR GA13-15286S; GA MŠk(CZ) LM2011026 Institutional support: RVO:68378271 Keywords : vapor pressure * dimethylcadmium * trimethylbismuth * tris(dimethylamino)antimony * sublimation and vaporization enthalpy Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.241, year: 2013

  20. Vapor pressures and thermophysical properties of selected monoterpenoids

    Czech Academy of Sciences Publication Activity Database

    Štejfa, V.; Dergal, F.; Mokbel, I.; Fulem, Michal; Jose, J.; Růžička, K.

    2015-01-01

    Roč. 406, Nov (2015), 124-133 ISSN 0378-3812 Institutional support: RVO:68378271 Keywords : monoterpenoids * vapor pressure * heat capacity * ideal - gas thermodynamic properties * vaporization and sublimation enthalpy Subject RIV: BJ - Thermodynamics Impact factor: 1.846, year: 2015

  1. Calculation of vapor pressure of fission product fluorides and oxyfluorides

    International Nuclear Information System (INIS)

    Roux, J.P.

    1976-03-01

    The equilibrium diagrams of the condensed phases - solid and liquid - and vapor phase are collected for the principal fluorides and oxyfluorides of fission product elements (atomic number from 30 to 66). These diagrams are used more particularly in fuel reprocessing by fluoride volatility process. Calculations and curves (vapor pressure in function of temperature) are processed using a computer program given in this report [fr

  2. Vapor-Liquid Equilibrium in Diluted Polymer plus Solvent Systems

    Czech Academy of Sciences Publication Activity Database

    Bogdanić, Grozdana; Wichterle, Ivan

    2011-01-01

    Roč. 56, č. 4 (2011), s. 1080-1083 ISSN 0021-9568 R&D Projects: GA ČR GA104/07/0444 Grant - others:MZOŠ(HR) 061-0000000-3029 Institutional research plan: CEZ:AV0Z40720504 Keywords : polymer * prediction * total pressure Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.693, year: 2011

  3. Evaluation of the Process of Solvent Vapor Annealing on Organic Thin Films

    KAUST Repository

    Ren, Yi

    2011-07-01

    Solvent vapor annealing has recently emerged as an intriguing, room-temperature, and highly versatile alternative to thermal annealing. The chemically selective interaction between solvents and organic semiconductors opens new opportunities to selectively anneal certain components of the device, while leaving others intact. On the downside, these interactions are complex and rather unpredictable, requiring further investigation. We propose a novel methodology to investigate solvent-film interactions, based on use of an in situ quartz crystal microbalance with dissipation (QCM-D) capability and in situ grazing incidence wide angle X-ray scattering (GIWAXS). These methods make it possible to investigate both qualitatively and quantitatively the solvent vapor uptake, the resulting softening and changes (reversible and/or irreversible) in crystallinity. Using this strategy, we have investigated the solvent vapor annealing of traditional donor and acceptor materials, namely poly(3-hexylthiophene-2,5-diyl) (P3HT) and [6,6]-Phenyl-C61-butyric acid methyl ester (PCBM). We find these materials retain their rigid structure during toluene vapor annealing and do not dewet. We also investigated the toluene vapor annealing of several newly proposed acceptor molecules (pentacene-based) modified with various silyl groups and electron withdrawing groups to tune the packing structure of the acceptor domains and energy levels at the donor-acceptor interface. We found a dramatic effect of the electron-withdrawing group on vapor uptake and whether the film remains rigid, softens, or dissolves completely. In the case of trifluoromethyl electron-withdrawing group, we found the film dissolves, resulting in complete and irreversible loss of long range order. By contrast, the cyano group prevented loss of long range order, instead promoting crystallization in some cases. The silyl groups had a secondary effect in comparison to these. In the last part of the thesis, we investigated the

  4. Analysis of potassium nitrate purification with recovery of solvent through single effect mechanical vapor compression

    Directory of Open Access Journals (Sweden)

    Kiprotich E. Kosgey

    2017-12-01

    Full Text Available Analysis of purification of potassium nitrate with incorporation of single effect mechanical vapor compressor for solvent recovery was done. Analysis focused on the effect of concentration and temperature of mother liquor on the energy efficiency of the process and the amount of recovered solvent. Performance coefficient of mechanical vapor compressor ranged between 1.5 and 7.5 depending primarily on the temperature of mother liquor. It was found that with increase in temperature of mother liquor through pre-heating, the power of the compressor, compression ratio and amount of heat supplied to the evaporator decrease. For a 40% concentrated feed solution and mother liquor temperature above 80 °C, performance coefficient is higher than 4. It is therefore concluded that preheating mother liquor and reduction of the effect of concentration of both mother liquor and concentrated waste stream through other methods reduces the power consumption of purification process. Keywords: Performance coefficient, Mother liquor, Concentrated solution, Recovered solvent, Boiling point elevation, Mechanical vapor compressor

  5. Solvent vapor annealing in the molecular regime drastically improves carrier transport in small-molecule thin-film transistors

    KAUST Repository

    Khan, Hadayat Ullah

    2013-04-10

    We demonstrate a new way to investigate and control the solvent vapor annealing of solution-cast organic semiconductor thin films. Solvent vapor annealing of spin-cast films of 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-Pn) is investigated in situ using quartz crystal microbalance with dissipation (QCM-D) capability, allowing us to monitor both solvent mass uptake and changes in the mechanical rigidity of the film. Using time-resolved grazing incidence wide angle X-ray scattering (GIWAXS) and complementary static atomic force microscopy (AFM), we demonstrate that solvent vapor annealing in the molecular regime can cause significant performance improvements in organic thin film transistors (OTFTs), whereas allowing the solvent to percolate and form a liquid phase results in catastrophic reorganization and dewetting of the film, making the process counterproductive. Using these lessons we devise processing conditions which prevent percolation of the adsorbed solvent vapor molecules for extended periods, thus extending the benefits of solvent vapor annealing and improving carrier mobility by nearly two orders of magnitude. Ultimately, it is demonstrated that QCM-D is a very powerful sensor of the state of the adsorbed solvent as well as the thin film, thus making it suitable for process development as well as in-line process monitoring both in laboratory and in future manufacturing settings. © 2013 American Chemical Society.

  6. Solvent vapor annealing in the molecular regime drastically improves carrier transport in small-molecule thin-film transistors

    KAUST Repository

    Khan, Hadayat Ullah; Li, Ruipeng; Ren, Yi; Chen, Long; Payne, Marcia M.; Bhansali, Unnat Sampatraj; Smilgies, Detlef Matthias; Anthony, John Edward; Amassian, Aram

    2013-01-01

    We demonstrate a new way to investigate and control the solvent vapor annealing of solution-cast organic semiconductor thin films. Solvent vapor annealing of spin-cast films of 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-Pn) is investigated in situ using quartz crystal microbalance with dissipation (QCM-D) capability, allowing us to monitor both solvent mass uptake and changes in the mechanical rigidity of the film. Using time-resolved grazing incidence wide angle X-ray scattering (GIWAXS) and complementary static atomic force microscopy (AFM), we demonstrate that solvent vapor annealing in the molecular regime can cause significant performance improvements in organic thin film transistors (OTFTs), whereas allowing the solvent to percolate and form a liquid phase results in catastrophic reorganization and dewetting of the film, making the process counterproductive. Using these lessons we devise processing conditions which prevent percolation of the adsorbed solvent vapor molecules for extended periods, thus extending the benefits of solvent vapor annealing and improving carrier mobility by nearly two orders of magnitude. Ultimately, it is demonstrated that QCM-D is a very powerful sensor of the state of the adsorbed solvent as well as the thin film, thus making it suitable for process development as well as in-line process monitoring both in laboratory and in future manufacturing settings. © 2013 American Chemical Society.

  7. A Solvent-Vapor Approach toward the Control of Block Ionomer Morphologies

    Energy Technology Data Exchange (ETDEWEB)

    Mineart, Kenneth P.; Lee, Byeongdu; Spontak, Richard J.

    2016-04-26

    Sulfonated block ionomers possess advantageous properties for a wide range of diverse applications such as desalination membranes, fuel cells, electroactive media, and photovoltaic devices. Unfortunately, their inherently high incompatibilities and glass transition temperatures e ff ectively prevent the use of thermal annealing, routinely employed to re fi ne the morphologies of nonionic block copolymers. An alternative approach is therefore required to promote morphological equilibration in block ionomers. The present study explores the morphological characteristics of midblock- sulfonated pentablock ionomers (SBIs) di ff ering in their degree of sulfonation (DOS) and cast from solution followed by solvent-vapor annealing (SVA). Transmission electron microscopy con fi rms that fi lms deposited from di ff erent solvent systems form nonequilibrium morphologies due to solvent-regulated self-assembly and drying. A series of SVA tests performed with solvents varying in polarity reveals that exposing cast fi lms to tetrahydrofuran (THF) vapor for at least 2 h constitutes the most e ff ective SVA protocol, yielding the anticipated equilibrium morphology. That is, three SBI grades subjected to THF-SVA self-assemble into well-ordered lamellae wherein the increase in DOS is accompanied by an increase in lamellar periodicity, as measured by small-angle X-ray scattering.

  8. The Yaws handbook of vapor pressure Antoine coefficients

    CERN Document Server

    Yaws, Carl L

    2015-01-01

    Increased to include over 25,000 organic and inorganic compounds, The Yaws Handbook of Vapor Pressure: Antoine Coefficients, 2nd Edition delivers the most comprehensive and practical database source for today's petrochemical. Understanding antoine coefficients for vapor pressure leads to numerous critical engineering applications such as pure components in storage vessels, pressure relief valve design, flammability limits at the refinery, as well as environmental emissions from exposed liquids, making data to efficiently calculate these daily challenges a fundamental need. Written by the world's leading authority on chemical and petrochemical data, The Yaws Handbook of Vapor Pressure simplifies the guesswork for the engineer and reinforces the credibility of the engineer's calculations with a single trust-worthy source. This data book is a must-have for the engineer's library bookshelf. Increase compound coverage from 8,200 to over 25,000 organic and inorganic compounds, including sulfur and hydrocarbons Sol...

  9. The vaporization enthalpy and vapor pressure of S (+)-methamphetamine at T = 298.15 K by correlation gas chromatography

    International Nuclear Information System (INIS)

    Thornton, Melissa; Gobble, Chase; Chickos, James

    2014-01-01

    Highlights: • The vaporization enthalpy of (d)-methamphetamine was measured. • The vapor pressure of (d)-methamphetamine as a function of temperature was evaluated. • The vapor pressure of 4-benzylpiperidine as a function of temperature was evaluated. - Abstract: The vaporization enthalpy and vapor pressure of S (+)-methamphetamine is evaluated by correlation-gas chromatography. A vaporization enthalpy of (58.7 ± 4.3) kJ · mol −1 and a vapor pressure, p = (38 ± 9) Pa has been obtained using a variety of secondary aliphatic amines as standards. In addition, equations describing the vapor pressure temperature dependence are provided for standards and S (+)-methamphetamine covering the temperature range from T = 298.15 K to the boiling temperature. Boiling temperatures are reproduced within an interval of 8 K or less

  10. Water-vapor pressure control in a volume

    Science.gov (United States)

    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.

  11. Vapor pressures and vapor compositions in equilibrium with hypostoichiometric plutonium dioxide at high temperatures

    International Nuclear Information System (INIS)

    Green, D.W.; Fink, J.K.; Leibowitz, L.

    1982-01-01

    Vapor pressures and vapor compositions have been calculated for 1500 less than or equal to T less than or equal to 4000 0 K. Thermodynamic functions for the condensed phase and for each of the gaseous species were combined with an oxygen-potential model extended into the liquid region to obtain the partial pressures of O 2 , O, Pu, PuO and PuO 2 . The calculated oxygen pressures increase very rapidly as stoichiometry is approached. At least part of this increase is a consequence of the exclusion of Pu 6 + from the oxygen-potential model. No reliable method was found to estimate the importance of this ion. As a result of large oxygen potentials at high temperatures, extremely high total pressures that produced unreasonably high vapor densities were calculated. The highest temperature was therefore limited to 400 K, and the range of oxygen-to-metal ratios was limited to 1.994 to 1.70. These calculations show that vapor in equilibrium with hypostoichiometric plutonium dioxide is poorly approximated as PuO 2 for most of the temperture and composition range of interest. The vapor is much more oxygen-rich than the condensed phase. Implications for the (U,Pu)O/sub 2-x/ system are discussed

  12. Vapor pressures and sublimation enthalpies of novel bicyclic heterocycle derivatives

    International Nuclear Information System (INIS)

    Blokhina, Svetlana V.; Ol’khovich, Marina V.; Sharapova, Angelica V.; Perlovich, German L.; Proshin, Alexey N.

    2014-01-01

    Highlights: • The vapor pressures of novel bicyclo-derivatives of amine were measured. • Thermodynamic functions of sublimation were calculated. • The influence of substituent structure and chemical nature on the vapor pressure was studied. -- Abstract: The vapor pressures of five novel bicyclic heterocycle derivatives were measured over the temperature 341.15 to 396.15 K using the transpiration method by means of an inert gas carrier. From these results the standard enthalpies and Gibbs free energies of sublimation at the temperature 298.15 K were calculated. The effects of alkyl- and chloro-substitutions on changes in the thermodynamic functions have been investigated. Quantitative structure–property relationship on the basis HYBOT physico-chemical descriptors for biologically active compounds have been developed to predict the sublimation enthalpies and Gibbs free energies of the compounds studied

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

    Science.gov (United States)

    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.

  14. Some empirical rules concerning the vapor pressure curve revisited

    International Nuclear Information System (INIS)

    Velasco, S.; White, J.A.

    2014-01-01

    Highlights: • A Claussius–Claperyron equation is obtained in the Pitzer corresponding states scheme. • Some well-known empirical rules for the vapor pressure are rewritten in terms of the Pitzer acentric factor. • The Guggenheim point follows the corresponding state scheme better than the normal boiling point. • The Ambrose–Walton vapor pressure equation yields excellent agreement with NIST data in all considered cases. -- Abstract: A form for the Clausius–Clapeyron vapor-pressure equation is obtained in the Pitzer corresponding states scheme. This equation allows one to rewrite the well-known Trouton, Guldberg, van Laar and Guggenheim rules in terms of the acentric factor ω. The original forms of these empirical rules are recovered for some particular values of ω. The proposed rules are checked by analyzing National Institute of Standards and Technology (NIST) data on the liquid-vapor coexistence curve for 105 fluids. These rules have been also analyzed by using the well-known Ambrose–Walton (AW) vapor pressure equation

  15. Cyclic Solvent Vapor Annealing for Rapid, Robust Vertical Orientation of Features in BCP Thin Films

    Science.gov (United States)

    Paradiso, Sean; Delaney, Kris; Fredrickson, Glenn

    2015-03-01

    Methods for reliably controlling block copolymer self assembly have seen much attention over the past decade as new applications for nanostructured thin films emerge in the fields of nanopatterning and lithography. While solvent assisted annealing techniques are established as flexible and simple methods for achieving long range order, solvent annealing alone exhibits a very weak thermodynamic driving force for vertically orienting domains with respect to the free surface. To address the desire for oriented features, we have investigated a cyclic solvent vapor annealing (CSVA) approach that combines the mobility benefits of solvent annealing with selective stress experienced by structures oriented parallel to the free surface as the film is repeatedly swollen with solvent and dried. Using dynamical self-consistent field theory (DSCFT) calculations, we establish the conditions under which the method significantly outperforms both static and cyclic thermal annealing and implicate the orientation selection as a consequence of the swelling/deswelling process. Our results suggest that CSVA may prove to be a potent method for the rapid formation of highly ordered, vertically oriented features in block copolymer thin films.

  16. A gas thermometer for vapor pressure measurements

    Science.gov (United States)

    Rusin, A. D.

    2008-08-01

    The pressure of an inert gas over the range 400 1000 K was measured on a tensimetric unit with a quartz membrane pressure gauge of enhanced sensitivity. It was shown that a reactor with a membrane null gauge could be used as a gas thermometer. The experimental confidence pressure and temperature intervals were 0.07 torr and 0.1 K at a significance level of 0.05. A Pt-Pt/10% Rh thermocouple was calibrated; the results were approximated by a polynomial of degree five. The error in temperature calculations was 0.25 K.

  17. The vapor pressure and enthalpy of vaporization of M-xylene

    Energy Technology Data Exchange (ETDEWEB)

    Rothenberg, S J; Seiler, F A; Bechtold, W E; Eidson, A F

    1988-12-01

    We measured the vapor pressure of m-xylene over the temperature range 273 to 293 deg K with a single-sided capacitance manometer. The enthalpy of vaporization was 42.2 {+-} 0.1 (SE) kj/ g{center_dot}mol. Combining our own data with previously published data, we recommend using the values 42.0, 40.6, and 39.1 ({+-} 0.1) (SE) kjg{center_dot}mol for the enthalpy of vaporization of m-xylene at 300, 340, and 380 deg. K, respectively, and a value for the change in heat capacity on vaporization ({delta}Cpdeg.) of 35 {+-} 3 (SE) J/g{center_dot}mol{center_dot}K over the temperature range studied. (author)

  18. The vapor pressure and enthalpy of vaporization of M-xylene

    International Nuclear Information System (INIS)

    Rothenberg, S.J.; Seiler, F.A.; Bechtold, W.E.; Eidson, A.F.

    1988-01-01

    We measured the vapor pressure of m-xylene over the temperature range 273 to 293 deg K with a single-sided capacitance manometer. The enthalpy of vaporization was 42.2 ± 0.1 (SE) kj/ g·mol. Combining our own data with previously published data, we recommend using the values 42.0, 40.6, and 39.1 (± 0.1) (SE) kjg·mol for the enthalpy of vaporization of m-xylene at 300, 340, and 380 deg. K, respectively, and a value for the change in heat capacity on vaporization (ΔCpdeg.) of 35 ± 3 (SE) J/g·mol·K over the temperature range studied. (author)

  19. Microwave measurements of water vapor partial pressure at high temperatures

    International Nuclear Information System (INIS)

    Latorre, V.R.

    1991-01-01

    One of the desired parameters in the Yucca Mountain Project is the capillary pressure of the rock comprising the repository. This parameter is related to the partial pressure of water vapor in the air when in equilibrium with the rock mass. Although there are a number of devices that will measure the relative humidity (directly related to the water vapor partial pressure), they generally will fail at temperatures on the order of 150C. Since thee author has observed borehole temperatures considerably in excess of this value in G-Tunnel at the Nevada Test Site (NTS), a different scheme is required to obtain the desired partial pressure data at higher temperatures. This chapter presents a microwave technique that has been developed to measure water vapor partial pressure in boreholes at temperatures up to 250C. The heart of the system is a microwave coaxial resonator whose resonant frequency is inversely proportional to the square root of the real part of the complex dielectric constant of the medium (air) filling the resonator. The real part of the dielectric constant of air is approximately equal to the square of the refractive index which, in turn, is proportional to the partial pressure of the water vapor in the air. Thus, a microwave resonant cavity can be used to measure changes in the relative humidity or partial pressure of water vapor in the air. Since this type of device is constructed of metal, it is able to withstand very high temperatures. The actual limitation is the temperature limit of the dielectric material in the cable connecting the resonator to its driving and monitoring equipment-an automatic network analyzer in our case. In the following sections, the theory of operation, design, construction, calibration and installation of the microwave diagnostics system is presented. The results and conclusions are also presented, along with suggestions for future work

  20. Vapor pressure of heat transfer fluids of absorption refrigeration machines and heat pumps: Binary solutions of lithium nitrate with methanol

    International Nuclear Information System (INIS)

    Safarov, Javid T.

    2005-01-01

    Vapor pressure p of LiNO 3 + CH 3 OH solutions at T = (298.15 to 323.15) K was reported, osmotic φ and activity coefficients γ; and activity of solvent a s have been evaluated. The experiments were carried out in molality range m = (0.18032 to 5.2369) mol . kg -1 . The Antoine equation was used for the empiric description of experimental vapor pressure results. The Pitzer-Mayorga model with inclusion of Archer's ionic strength dependence of the third virial coefficient was used for the description of calculated osmotic coefficients. The parameters of Archer extended Pitzer model were used for evaluation of activity coefficients

  1. Bibliography on vapor pressure isotope effects

    International Nuclear Information System (INIS)

    Jancso, G.

    1980-04-01

    The first Bibliography on Vapour Pressure Isotope and covered the literature of the period from 1919 through December 1975. The present Supplement reviews the literature from January 1976 through December 1979. The bibliography is arranged in chronological order; within each year the references are listed alphabetically according to the name of the first author of each work. (author)

  2. Micron-sized columnar grains of CH3NH3PbI3 grown by solvent-vapor assisted low-temperature (75 °C) solid-state reaction: The role of non-coordinating solvent-vapor

    Science.gov (United States)

    Zheng, Huifeng; Liu, Yangqiao; Sun, Jing

    2018-04-01

    The preparation of hybrid perovskite films with large columnar grains via low-temperature solid-state reaction remains a big challenge. Conventional solvent annealing using DMF, DMSO and ethanol, etc. fails to work effectively at low temperature (solar cells based on benzyl-alcohol-vapor annealing (75 °C), delivered much higher photovoltaic performance, better stability and smaller hysteresis than those based on conventional thermal annealing. Additionally, a champion power conversion efficiency (PCE) of 15.1% was obtained and the average PCE reached 12.2% with a tiny deviation. Finally, the mechanism of solvent annealing with non-coordinating solvent was discussed. Moreover, we revealed that high polarity and high boiling point of the solvent used for generating vapor, was critical to grow micron-sized columnar grains at such a low temperature (75 °C). This work will contribute to understanding the mechanism of grain growth in solvent annealing and improving its facility and effectiveness.

  3. The detection of organic solvent vapor by using polymer coated chemocapacitor sensor

    Science.gov (United States)

    Rusdiarna Indrapraja, Apik; Rivai, Muhammad; Arifin, Achmad; Purwanto, Djoko

    2017-05-01

    A chemocapacitor consists of planar interdigital electrodes (IDE) made by two comb electrodes on a substrate. A dielectric film was applied on the electrodes in which the absorbed vapor will modify its permittivity. This study has fabricated chemocapacitor with the IDE distance of 0.5 mm, while the dielectric film was a sensitive layer consisting of a polymeric material. The deposition of the polymeric film was accomplished by drop casting. A sensor array consisting of four chemocapacitors coated with different polymers namely PEG-1540, PEG-20M, PEG-6000, and PVP was used to obtain the pattern of shift in the capacitance. The integrated circuit AD7746 was used as the capacitance to-digital converter (CDC). The organic solvents of ethanol, benzene, and aceton were used as the vapor samples in this experiment. The results showed that the change in the capacitance value increases proportionally to the concentration of vapour where sensors coated with PEG-1540 and PVP have higher sensitivity, i.e. 0.0028pF/part per thousand and 0.0027pF/part per thousand, respectively. Based on the capacitance to digital conversion capabilities, the system provides there solution of 0.4084ppm. The sensor array could produce a different pattern for each of the vapor sample. The Neural Network pattern recognition system could identify the type of vapor automatically with the root mean square error of 10-5

  4. Determination of solvent concentration-dependent dispersion in the vapor extraction (VAPEX) process

    Energy Technology Data Exchange (ETDEWEB)

    Abukhalifeh, H.; Lohi, A.; Upreti, S. [Ryerson Polytechnic Univ., Toronto, ON (Canada)

    2008-07-01

    This paper presented the results of a computational algorithm that revealed the optimal conditions required for vapor extraction (VAPEX) for a solvent gas-heavy oil system. VAPEX is a promising recovery process because it requires low energy use and emits fewer greenhouse gases to the atmosphere compared to other enhanced oil recovery methods. The process is governed by the dispersion of solvent gases into heavy oil and bitumen. As such, it is essential to accurately determine solvent dispersion in VAPEX in order to effectively predict the amount and time scale of oil recovery, and to optimize field operations. VAPEX experiments were conducted in this study to determined the dispersion coefficient of a solvent as a function of its concentration in heavy oil and bitumen. The principles of variational calculus were used together with a mass transfer model of the experimental process. It was concluded that the oil production determined by the model should agree with its experimental counterpart, given the optimal gas dispersion versus concentration function.

  5. Vapor Pressure of Selected Aliphatic Alcohols by Ebulliometry. Part 1

    Czech Academy of Sciences Publication Activity Database

    Čenský, M.; Roháč, V.; Růžička, K.; Fulem, M.; Aim, Karel

    2010-01-01

    Roč. 298, č. 2 (2010), s. 192-198 ISSN 0378-3812 R&D Projects: GA AV ČR IAA400720710 Institutional research plan: CEZ:AV0Z40720504 Keywords : vapor pressure * ebulliometry * aliphatic alcohols Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.253, year: 2010

  6. Saturated vapor pressure of lutetium tris-acetylacetonate

    Energy Technology Data Exchange (ETDEWEB)

    Trembovetskij, G.V.; Berdonosov, S.S.; Murav' eva, I.A.; Martynenko, L.I. (Moskovskij Gosudarstvennyj Univ. (USSR))

    1983-12-01

    By the statical method using /sup 177/Lu radioactive isotope the saturated vapor pressure of anhydrous lutetium acetylacetonate at 130 to 160 deg is determined. The calculations are carried out assuming the vapor to be monomolecular. The equation of lgP versus 1/T takes the form: lg Psub((mmHg))=(8.7+-1.6)-(4110+-690)/T. The thermodynamical characteristics of LuA/sub 3/ sublimation are calculated to be ..delta..Hsub(subl.)=79+-13 kJ/mol; ..delta..Ssub(subl.)=111+-20 J/kxmol.

  7. Toward an equilibrium structure in lamellar diblock copolymer thin films using solvent vapor annealing

    DEFF Research Database (Denmark)

    Sepe, Alessandro; Zhang, Jianqi; Perlich, Jan

    2016-01-01

    Solvent vapor annealing (SVA) is frequently used to improve the ordering in diblock copolymer thin films. An important question is which SVA protocol should be chosen to ensure thermodynamic equilibrium. Here, we investigate two thin films from a low molar-mass, lamellae-forming polystyrene....... SVA cycles were carried out with cyclohexane, and the structural changes were followed in-situ using time-resolved grazing-incidence small-angle X-ray scattering (GISAXS). Before and after SVA, Dlam,par is significantly lower than in the bulk, i.e. the equi-librium value of Dlam,par in thin film...... glassy again, affinely. During the second SVA cycle on the thin film, the scaling behavior of the lamellar thickness is identical to the one during the first drying and to the drying behavior of the thicker film. We conclude that one cycle of solvent vapor treatment with a degree of swelling of ca. 1...

  8. A generalized method for alignment of block copolymer films: solvent vapor annealing with soft shear.

    Science.gov (United States)

    Qiang, Zhe; Zhang, Yuanzhong; Groff, Jesse A; Cavicchi, Kevin A; Vogt, Bryan D

    2014-08-28

    One of the key issues associated with the utilization of block copolymer (BCP) thin films in nanoscience and nanotechnology is control of their alignment and orientation over macroscopic dimensions. We have recently reported a method, solvent vapor annealing with soft shear (SVA-SS), for fabricating unidirectional alignment of cylindrical nanostructures. This method is a simple extension of the common SVA process by adhering a flat, crosslinked poly(dimethylsiloxane) (PDMS) pad to the BCP thin film. The impact of processing parameters, including annealing time, solvent removal rate and the physical properties of the PDMS pad, on the quality of alignment quantified by the Herman's orientational factor (S) is systematically examined for a model system of polystyrene-block-polyisoprene-block-polystyrene (SIS). As annealing time increases, the SIS morphology transitions from isotropic rods to highly aligned cylinders. Decreasing the rate of solvent removal, which impacts the shear rate imposed by the contraction of the PDMS, improves the orientation factor of the cylindrical domains; this suggests the nanostructure alignment is primarily induced by contraction of PDMS during solvent removal. Moreover, the physical properties of the PDMS controlled by the crosslink density impact the orientation factor by tuning its swelling extent during SVA-SS and elastic modulus. Decreasing the PDMS crosslink density increases S; this effect appears to be primarily driven by the changes in the solubility of the SVA-SS solvent in the PDMS. With this understanding of the critical processing parameters, SVA-SS has been successfully applied to align a wide variety of BCPs including polystyrene-block-polybutadiene-block-polystyrene (SBS), polystyrene-block-poly(N,N-dimethyl-n-octadecylammonium p-styrenesulfonate) (PS-b-PSS-DMODA), polystyrene-block-polydimethylsiloxane (PS-b-PDMS) and polystyrene-block-poly(2-vinlypyridine) (PS-b-P2VP). These results suggest that SVA-SS is a generalizable

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

    Science.gov (United States)

    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.

  10. Temperature dependences of saturated vapor pressure and the enthalpy of vaporization of n-pentyl esters of dicarboxylic acids

    Science.gov (United States)

    Portnova, S. V.; Krasnykh, E. L.; Levanova, S. V.

    2016-05-01

    The saturated vapor pressures and enthalpies of vaporization of n-pentyl esters of linear C2-C6 dicarboxylic acids are determined by the transpiration method in the temperature range of 309.2-361.2 K. The dependences of enthalpies of vaporization on the number of carbon atoms in the molecule and on the retention indices have been determined. The predictive capabilities of the existing calculation schemes for estimation of enthalpy of vaporization of the studied compounds have been analyzed.

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

    Science.gov (United States)

    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.

  12. Vapor pressure lowering effects due to salinity and suction pressure in the depletion of vapor-dominated geothermal reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Battistelli, A. [Aquater S.p.A., Pisa (Italy); Calore, C. [Istituto Internazionale per le Ricerche Geotermiche-CNR, Pisa (Italy); Pruess, K. [Lawrence Berkeley Lab., Berkeley, CA (United States)

    1995-03-01

    The equation-of-state module able to handle saline brines with non-condensible gas, developed for the TOUGH2 simulator, has been improved to include vapor pressure lowering (VPL) due to suction pressure as represented by Kelvin`s equation. In this equation the effects of salt are considered whereas those of non-condensible gas have currently been neglected. Numerical simulations of fluid production from tight matrix blocks have been performed to evaluate the impact of VPL effects due to salinity and suction pressure on the depletion behaviour of vapor-dominated geothermal reservoirs. Previous studies performed neglected VPL due to suction pressure showed that for initial NaCl mass fractions above threshold values, {open_quotes}sealing{close_quotes} of the block occurs and large amounts of liquid fluid may not be recovered. On the other hand, below the threshold value the matrix block dries out due to fluid production. The inclusion of VPL due to suction pressure does not allow complete vaporization of the liquid phase. As a result, the threshold NaCl concentration above which sealing of the matrix block occurs is increased. Above the {open_quotes}critical{close_quotes} NaCl concentration, block depletion behaviour with and without the VPL due to suction pressure is almost identical, as liquid phase saturation remains high even after long production times. As the VPL due to suction pressure depends mainly on capillary pressure, the shape of capillary pressure functions used in numerical simulations is important in determining VPL effects on block depletion.

  13. Vapor pressures and vapor compositions in equilibrium with hypostoichiometric uranium-plutonium dioxide at high temperatures

    International Nuclear Information System (INIS)

    Green, D.W.; Fink, J.K.; Leibowitz, L.

    1982-01-01

    Vapor pressures and vapor compositions in equilibrium with a hypostoichiometric uranium-plutonium dioxide condensed phase (U/sub 1-y/Pu/sub y/)O/sub 2-x/, as functions of T, x, and y, have been calculated for 0.0 less than or equal to x less than or equal to 0.1, 0.0 less than or equal to y less than or equal to 0.3, and for the temperature range 2500 less than or equal to T less than or equal to 6000 K. The range of compositions and temperatures was limited to the region of interest to reactor safety analysis. Thermodynamic functions for the condensed phase and for each of the gaseous species were combined with an oxygen potential model to obtain partial pressures of O, O 2 , Pu, PuO, PuO 2 , U, UO, UO 2 , and UO 3 as functions of T, x, and y

  14. Vapor pressures and vaporization enthalpy of (−) α-bisabolol and (dl) menthol by correlation gas chromatography

    International Nuclear Information System (INIS)

    Keating, Leasa; Harris, Harold H.; Chickos, James S.

    2017-01-01

    Highlights: • The vaporization enthalpy and vapor pressure of (−) α-bisabolol and (dl)-menthol have been measured as a function of temperature. • Vapor pressures, vaporization enthalpies and boiling temperatures have been compared to available literature data. • Vapor pressures of (l)-menthol are compared to (dl)-menthol. - Abstract: The vapor pressures and vaporization enthalpies of (−) α-bisabolol and (dl)-menthol, two GRAS chemicals (generally recognized as safe) are evaluated by correlation gas chromatography using a series of saturated primary alcohols as standards. Vaporization enthalpies of (96.6 ± 2.4) and (74.2 ± 2.8) kJ mol −1 and vapor pressures of p/Pa = (0.020 ± 0.003) and (4.5 ± 0.44) were evaluated at T = 298.15 K for (−) α-bisabolol and (dl)-menthol, respectively, and compared to literature values. The vapor pressures of both compounds from T = (298.15 to 500) K have been derived from correlations using vapor pressures of a series of 1-alkanols and corresponding gas chromatographic retention times at 10 K intervals. The results were fit to a second order polynomial. Calculated normal boiling temperatures of T B = (574.8 and 492.7) K are calculated for (−) α-bisabolol and (dl)-menthol, respectively. A normal boiling temperature of T B = (485.2, and 489.7) K has previously been reported for (dl)-menthol. Vapor pressures for both (l)-menthol and (dl)-menthol from a previous study and (dl)-menthol from this study are compared with literature values.

  15. On Localized Vapor Pressure Gradients Governing Condensation and Frost Phenomena.

    Science.gov (United States)

    Nath, Saurabh; Boreyko, Jonathan B

    2016-08-23

    Interdroplet vapor pressure gradients are the driving mechanism for several phase-change phenomena such as condensation dry zones, interdroplet ice bridging, dry zones around ice, and frost halos. Despite the fundamental nature of the underlying pressure gradients, the majority of studies on these emerging phenomena have been primarily empirical. Using classical nucleation theory and Becker-Döring embryo formation kinetics, here we calculate the pressure field for all possible modes of condensation and desublimation in order to gain fundamental insight into how pressure gradients govern the behavior of dry zones, condensation frosting, and frost halos. Our findings reveal that in a variety of phase-change systems the thermodynamically favorable mode of nucleation can switch between condensation and desublimation depending upon the temperature and wettability of the surface. The calculated pressure field is used to model the length of a dry zone around liquid or ice droplets over a broad parameter space. The long-standing question of whether the vapor pressure at the interface of growing frost is saturated or supersaturated is resolved by considering the kinetics of interdroplet ice bridging. Finally, on the basis of theoretical calculations, we propose that there exists a new mode of frost halo that is yet to be experimentally observed; a bimodal phase map is developed, demonstrating its dependence on the temperature and wettability of the underlying substrate. We hope that the model and predictions contained herein will assist future efforts to exploit localized vapor pressure gradients for the design of spatially controlled or antifrosting phase-change systems.

  16. Vapor Pressure of N,N’-Diisopropylcarbodiimide (DICDI)

    Science.gov (United States)

    2016-02-01

    11. Furumoto, S. The Synthesis of Carbodiimides from N,N-Disubstituted Thioureas and 2- Chloro-4,6-dimethylpyrimidine, 2,4-Dichloropyrimidine or...N-Phenylbenzimidoyl Chloride . Journal of Synthetic Organic Chemistry, Japan 1975, 33, 748–752. 12. Kagami, H.; Hanzawa, N.; Suzuki, N.; Yamaguchi...25. Brozena, A.; Buchanan, J.H.; Miles, R.W., Jr.; Williams, B.R.; Hulet, M.S. Vapor Pressure of Triethyl and Tri-n- Propyl Phosphates and Diethyl

  17. Density, viscosity, and saturated vapor pressure of ethyl trifluoroacetate

    International Nuclear Information System (INIS)

    Huang, Zhixian; Jiang, Haiming; Li, Ling; Wang, Hongxing; Qiu, Ting

    2015-01-01

    Highlights: • Density of ethyl trifluoroacetate was measured and its thermal expansion coefficient was determined. • Viscosity of ethyl trifluoroacetate was measured and fitted to the Andrade equation. • Saturated vapor pressure of ethyl trifluoroacetate was reported. • The Clausius–Clapeyron equation was used to calculate the molar evaporation enthalpy of ethyl trifluoroacetate. - Abstract: The properties of ethyl trifluoroacetate (CF 3 COOCH 2 CH 3 ) were measured as a function of temperature: density (278.08 to 322.50) K, viscosity (293.45 to 334.32) K, saturated vapor pressure (293.35 to 335.65) K. The density data were fitted to a quadratic polynomial equation, and the viscosity data were regressed to the Andrade equation. The correlation coefficient (R 2 ) of equations for density and viscosity are 0.9997 and 0.9999, respectively. The correlation between saturated vapor pressures and temperatures was achieved with a maximum absolute relative deviation of 0.142%. In addition, the molar evaporation enthalpy in the range of T = (293.35 to 335.65) K was estimated by the Clausius–Clapeyron equation

  18. Vapor pressures and enthalpies of vaporization of a series of 1- and 2-halogenated naphthalenes

    International Nuclear Information System (INIS)

    Verevkin, Sergey P.

    2003-01-01

    Molar enthalpies of vaporization, Δ l g H m 0 , of 1-methyl-naphthalene, 1-chloro-napthalene, 2-chloro-naphthalene, 1-bromo-naphthalene, 2-bromo-naphthalene, and 1-iodo-naphthalene, as well as molar enthalpies of sublimation, Δ s g H m 0 , of 2-chloro-naphthalene and 2-bromo-naphthalene have been obtained from the temperature dependence of the vapor pressure determined with the transpiration method. These values and the correlation gas-chromatography method, based on the Kovat's index, have been used to determine Δ l g H m 0 and Δ s g H m 0 of 2-iodo-naphthalene. Results obtained in this work have been compared with those from the literature and found consistent

  19. Thermal behaviour of agitated gas-liquid reactors with a vaporizing solvent/air oxidation of hydrocarbons

    NARCIS (Netherlands)

    Westerterp, K.R.; Crombeen, P.R.J.J.

    1983-01-01

    Many highly exothermic gas-liquid reactions are carried out with a vaporizing solvent, which after condensation is returned to the reactor. In this way the liberated reaction heat for a large part is absorbed by the cooling water flowing through the condenser. In order to determine the influence of

  20. Vapor pressures and enthalpies of vaporization of a series of γ and δ-lactones by correlation gas chromatography

    International Nuclear Information System (INIS)

    Kozlovskiy, Mikhail; Gobble, Chase; Chickos, James

    2014-01-01

    Highlights: • The vaporization enthalpies of γ-octanolactone, γ- and δ-undecanolactone and γ and δ-dodecanolactone are reported. • Equations for predicting the vapor pressures over the temperature range T = (298.15 to 350) K are provided. • Vaporization enthalpies are compared to predicted values. - Abstract: The vaporization enthalpies of γ-octanolactone, γ- and δ-undecanolactone and γ and δ-dodecanolactone used commercially as flavor ingredients are reported as are their vapor pressures over the temperature range T = (298.15 to 350) K. Vaporization enthalpies at T = 298.15 K of: (66.0 ± 3.9), (79.4 ± 4.4), (80.1 ± 4.5), (83.9 ± 4.6), and (84.61 ± 4.7) kJ · mol −1 and vapor pressures also at T = 298.15 K of: (2.8 ± 0.9), (0.12 ± 0.05), (0.09 ± 0.04), (0.04 ± 0.02), and (0.03 ± 0.02) Pa, respectively, have been evaluated by correlation gas chromatography experiments. The vaporization enthalpies of the lactones studied are reproduced within ±0.5 kJ · mol −1 using a group additivity scheme reported previously for γ- and δ-lactones. The vaporization enthalpies of the γ- and δ-lactones are compared to a similar series of ω-lactones

  1. Prediction of vapor pressure and heats of vaporization of edible oil/fat compounds by group contribution

    DEFF Research Database (Denmark)

    Ceriani, Roberta; Gani, Rafiqul; Liu, Y.A.

    2013-01-01

    In the present work, a group contribution method is proposed for the estimation of vapor pressures and heats of vaporization of organic liquids found in edible fat/oil and biofuel industries as a function of temperature. The regression of group contribution parameters was based on an extensive...

  2. Supplementary vapor pressure data of the glycol ethers, 1-methoxy-2-propanol, and 2-methoxyethanol at a pressure range of (15 to 177) kPa

    International Nuclear Information System (INIS)

    Bejarano, Arturo; Poveda, Laura J.; Fuente, Juan C. de la

    2012-01-01

    Highlights: ► Vapor pressure of 2-methoxyethanol and 1-methoxy-2-propanol were measured. ► Complementary data are reported at ranges of (342 to 417) K and (15 to 177) kPa. ► Three commonly used vapor pressure equations were fitted to experimental data. ► The parameters of Antoine and Wagner type equations were estimated. ► The relative deviations (rmsd) from the three vapor pressure equations were <0.4%. - Abstract: The vapor pressure of pure 1-methoxy-2-propanol and 2-methoxyethanol, commonly used as co-solvents in inks, paints, coatings, organic/water solutions among many other applications, were measured with a dynamic recirculation apparatus at a pressure range of (15 to 177) kPa. The measurements were performed at temperature ranges of (342 to 412) K for 1-methoxy-2-propanol and (346 to 417) K for 2-methoxyethanol. The maximum likelihood method was used to estimate the parameters of the Antoine equation, the parameters of an extended Antoine equation and the Wagner equation were determined by non linear least squares method. The three models showed root mean square deviations (rmsd) of 0.39%, 0.38%, and 0.29%, and 0.37%, 0.33%, and 0.32%, for 1-methoxy-2-propanol and 2-methoxyethanol, respectively. Additionally, the experimental data and correlation were compared with those available in the literature.

  3. Screening for organic solvents in Hanford waste tanks using organic vapor concentrations

    International Nuclear Information System (INIS)

    Huckaby, J.L.; Sklarew, D.S.

    1997-09-01

    The potential ignition of organic liquids stored in the Hanford Site high-level radioactive waste tanks has been identified as a safety issue because expanding gases could potentially affect tank dome integrity. Organic liquid waste has been found in some of the waste tanks, but most are thought to contain only trace amounts. Due to the inhomogeneity of the waste, direct sampling of the tank waste to locate organic liquids may not conclusively demonstrate that a given tank is free of risk. However, organic vapors present above the organic liquid waste can be detected with a high degree of confidence and can be used to identify problem tanks. This report presents the results of a screening test that has been applied to 82 passively ventilated high-level radioactive waste tanks at the Hanford Site to identify those that might contain a significant amount of organic liquid waste. It includes seven tanks not addressed in the previous version of this report, Screening for Organic Solvents in Hanford Waste Tanks Using Total Non-Methane Organic Compound Vapor Concentrations. The screening test is based on a simple model of the tank headspace that estimates the effective surface area of semivolatile organic liquid waste in a tank. Analyses indicate that damage to the tank dome is credible only if the organic liquid burn rate is above a threshold value, and this can occur only if the surface area of organic liquid in a tank is above a corresponding threshold value of about one square meter. Thirteen tanks were identified as potentially containing at least that amount of semivolatile organic liquid based on conservative estimates. Most of the tanks identified as containing potentially significant quantities of organic liquid waste are in the 241-BY and 241-C tank farms, which agrees qualitatively with the fact that these tank farms received the majority of the PUREX process organic wash waste and waste organic liquids

  4. Dynamic of vapor bubble growth in fields of variable pressure

    International Nuclear Information System (INIS)

    Pedroso, H.K.

    1982-01-01

    A mathematical model for the description of the growth from an initial nucleus of a vapor bubble imersed in liquid, subjected to a loss of pressure is presented. The model is important for analysing LOCA (Loss of Coolant Acident) in P.W.R. type reactors. Several simplifications were made in the phenomenum governing equations. With such simplifications the heat diffusion equation became the determining factor for the bubble growth, and the problem was reduced to solve the heat diffusion equation for semi infinite solid whose surface temperature is a well known function of time (it is supposed that the surface temperature is equal to the saturation temperature of the liquid at the system pressure at a given moment). The model results in an analytical expression for the bubble radius as a function of time. Comparisons with experimental data and previous models were made, with reasonable agreement. (author) [pt

  5. Vapor pressure of plutonium carbide adsorbed on graphite

    International Nuclear Information System (INIS)

    Tallent, O.K.; Wichner, R.P.; Towns, R.L.; Godsey, T.T.

    1984-09-01

    An investigation was conducted to obtain data needed to make realistic estimates of plutonium contamination in the primary coolant system in High Temperature Gas-Cooled Reactors (HTGRs). The vapor pressure of plutonium over plutonium sesquicarbide (Pu 2 C 3 ) adsorbed on the surface of H-451 graphite was found to be defined by adsorption isotherms at test temperatures of 1000, 1200, and 1400 0 C. The vapor pressures at low concentrations of Pu 2 C 3 on the surface of the graphite were up to three orders of magnitude below that of pure Pu 2 C 3 at a given temperature. The heat of adsorption increases with decreasing Pu 2 C 3 surface coverage with the measured value at 0.05 μmol Pu 2 C 3 /m 2 being 107.9 kcal/mol. The Pu 2 C 3 concentration required for monolayer surface coverage on the graphite was found to be 3.27 μmol/m 2

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

    Science.gov (United States)

    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

  7. Physico-chemical characterization antituberculosis thioacetazone: Vapor pressure, solubility and lipophilicity

    International Nuclear Information System (INIS)

    Sharapova, Angelica; Ol'khovich, Marina; Blokhina, Svetlana; Perlovich, German

    2017-01-01

    Highlights: • Vapor pressures of antituberculosis thioacetazone were determined by transpiration method. • Solubilities of the TAZ in four modeling solvents were measured at different temperatures. • Temperature dependence of octanol/buffer pH 7.4 partition coefficients was obtained. • Thermodynamics parameters of solubility, sublimation, solvation and transfer were calculated. - Abstract: Vapor pressure of thioacetazone (TAZ) has been determined in the temperature range of 404.15–429.15 K by the transpiration method. The obtained data were used to calculate the standard molar enthalpy of sublimation that was found to be 164.1 kJ/mol at T = 298.15 K. The drug solubility was measured at seven temperatures from 288.15 to 318.15 K in modeling solvents: octanol, hexane and aqueous buffers pH 2.0 and 7.4 by the saturation shake-flask method by using spectrophotometric analysis. It has been found that TAZ has poor solubility in hexane and buffer solutions and limited solubility in octanol. The experimental data were well correlated by van’t Hoff and modified Apelblat equations. A temperature dependence of TAZ partition coefficient in the octanol/buffer pH 7.4 system has been derived. The partition coefficient value in this system (logP = 1.82) refers to the optimal interval for oral absorption drugs. The thermodynamic parameters of sublimation, solubility, solvation and transfer have been determined based on experimental data. The dominant effect of enthalpy and entropy contributions to the Gibbs energy of the investigated processes has been revealed.

  8. Measuring Vapor Pressure with an Isoteniscope: A Hands-on Introduction to Thermodynamic Concepts

    Science.gov (United States)

    Chen, Wenqian; Haslam, Andrew J.; Macey, Andrew; Shah, Umang V.; Brechtelsbauer, Clemens

    2016-01-01

    Characterization of the vapor pressure of a volatile liquid or azeotropic mixture, and its fluid phase diagram, can be achieved with an isoteniscope and an industrial grade digital pressure sensor using the experimental method reported in this study. We describe vapor-pressure measurements of acetone and n-hexane and their azeotrope, and how the…

  9. Solid vapor pressure for five heavy PAHs via the Knudsen effusion method

    International Nuclear Information System (INIS)

    Fu Jinxia; Suuberg, Eric M.

    2011-01-01

    Highlights: → We report on vapor pressures and enthalpies of fusion and sublimation of five heavy PAHs. → Solid vapor pressures were measured using Knudsen effusion method. → Solid vapor pressures for benzo[b]fluoranthene, and indeno[1,2,3-cd]pyrene have not been published in the open literature. → Reported subcooled liquid state vapor pressures may or may not lend themselves to correction to sublimation vapor pressure. → Subcooled liquid state vapor pressures might sometimes actually be closer to actual solid state sublimation vapor pressures. - Abstract: Polycyclic aromatic hydrocarbons (PAHs) are compounds resulting from incomplete combustion and many fuel processing operations, and they are commonly found as subsurface environmental contaminants at sites of former manufactured gas plants. Knowledge of their vapor pressures is the key to predict their fate and transport in the environment. The present study involves five heavy PAHs, i.e. benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[ghi]perylene, indeno[1,2,3-cd]pyrene, and dibenz[a,h]anthracene, which are all as priority pollutants classified by the US EPA. The vapor pressures of these heavy PAHs were measured by using Knudsen effusion method over the temperature range of (364 to 454) K. The corresponding values of the enthalpy of sublimation were calculated from the Clausius-Clapeyron equation. The enthalpy of fusion for the five PAHs was also measured by using differential scanning calorimetry and used to convert earlier published sub-cooled liquid vapor pressure data to solid vapor pressure in order to compare with the present results. These adjusted values do not agree with the present measured actual solid vapor pressure values for these PAHs, but there is good agreement between present results and other earlier published sublimation data.

  10. Effects of Solvent and Ion Source Pressure on the Analysis of Anabolic Steroids by Low Pressure Photoionization Mass Spectrometry

    Science.gov (United States)

    Liu, Chengyuan; Zhu, Yanan; Yang, Jiuzhong; Zhao, Wan; Lu, Deen; Pan, Yang

    2017-04-01

    Solvent and ion source pressure were two important factors relating to the photon induced ion-molecule reactions in low pressure photoionization (LPPI). In this work, four anabolic steroids were analyzed by LPPI mass spectrometry. Both the ion species present and their relative abundances could be controlled by switching the solvent and adjusting the ion source pressure. Whereas M•+, MH+, [M - H2O]+, and solvent adducts were observed in positive LPPI, [M - H]- and various oxidation products were abundant in negative LPPI. Changing the solvent greatly affected formation of the ion species in both positive and negative ion modes. The ion intensities of the solvent adduct and oxygen adduct were selectively enhanced when the ion source pressure was elevated from 68 to 800 Pa. The limit of detection could be decreased by increasing the ion source pressure.

  11. Effects of Solvent and Ion Source Pressure on the Analysis of Anabolic Steroids by Low Pressure Photoionization Mass Spectrometry.

    Science.gov (United States)

    Liu, Chengyuan; Zhu, Yanan; Yang, Jiuzhong; Zhao, Wan; Lu, Deen; Pan, Yang

    2017-04-01

    Solvent and ion source pressure were two important factors relating to the photon induced ion-molecule reactions in low pressure photoionization (LPPI). In this work, four anabolic steroids were analyzed by LPPI mass spectrometry. Both the ion species present and their relative abundances could be controlled by switching the solvent and adjusting the ion source pressure. Whereas M •+ , MH + , [M - H 2 O] + , and solvent adducts were observed in positive LPPI, [M - H] - and various oxidation products were abundant in negative LPPI. Changing the solvent greatly affected formation of the ion species in both positive and negative ion modes. The ion intensities of the solvent adduct and oxygen adduct were selectively enhanced when the ion source pressure was elevated from 68 to 800 Pa. The limit of detection could be decreased by increasing the ion source pressure. Graphical Abstract ᅟ.

  12. Investigation of the vapor pressure p of zinc bromide or zinc chloride solutions with methanol by static method

    International Nuclear Information System (INIS)

    Safarov, Javid T.

    2006-01-01

    Vapor pressures p of ZnBr 2 + CH 3 OH and ZnCl 2 + CH 3 OH solutions at T (298.15 to 323.15) K were measured, activity of solvent a s and osmotic φ coefficients have been evaluated. The experiments were carried out for the ZnBr 2 + CH 3 OH solutions in the molality range m = (0.19972 to 11.05142) mol . kg -1 and for the ZnCl 2 + CH 3 OH solutions in the molality range m (0.42094 to 8.25534) mol . kg -1 . The Antoine equation for the empirical description of the experimental vapor pressure results and the Pitzer-Mayorga model with inclusion of ionic strength dependence of the third virial coefficient for the description of calculated osmotic coefficients were used. The parameters of Pitzer-Mayorga model were used for evaluation of activity coefficients

  13. Vapor pressure of heat transfer fluids of absorption refrigeration machines and heat pumps: Binary solutions of lithium nitrate with methanol

    Energy Technology Data Exchange (ETDEWEB)

    Safarov, Javid T. [Heat and Refrigeration Techniques, Azerbaijan Technical University, Huseyn Javid Avn. 25, AZ1073 Baku (Azerbaijan)]. E-mail: javids@azdata.net

    2005-12-15

    Vapor pressure p of LiNO{sub 3} + CH{sub 3}OH solutions at T = (298.15 to 323.15) K was reported, osmotic {phi} and activity coefficients {gamma}; and activity of solvent a {sub s} have been evaluated. The experiments were carried out in molality range m = (0.18032 to 5.2369) mol . kg{sup -1}. The Antoine equation was used for the empiric description of experimental vapor pressure results. The Pitzer-Mayorga model with inclusion of Archer's ionic strength dependence of the third virial coefficient was used for the description of calculated osmotic coefficients. The parameters of Archer extended Pitzer model were used for evaluation of activity coefficients.

  14. Highly crystalline films of PCPDTBT with branched side chains by solvent vapor crystallization: influence on opto-electronic properties.

    Science.gov (United States)

    Fischer, Florian S U; Trefz, Daniel; Back, Justus; Kayunkid, Navaphun; Tornow, Benjamin; Albrecht, Steve; Yager, Kevin G; Singh, Gurpreet; Karim, Alamgir; Neher, Dieter; Brinkmann, Martin; Ludwigs, Sabine

    2015-02-18

    PCPDTBT, a marginally crystallizable polymer, is crystallized into a new crystal structure using solvent-vapor annealing. Highly ordered areas with three different polymer-chain orientations are identified using TEM/ED, GIWAXS, and polarized Raman spectroscopy. The optical and structural properties differ significantly from films prepared by standard device preparation protocols. Bilayer solar cells, however, show similar performance. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Atmospheric sugar alcohols: evaporation rates and saturation vapor pressures

    DEFF Research Database (Denmark)

    Bilde, Merete; Zardini, Alessandro Alessio; Hong, Juan

    alcohols. These polyols are common in the water soluble fraction of atmospheric aerosols. In our experimental system sub-micron particles are generated by nebulization from aqueous solution, and a mono disperse fraction of the aerosol is selected using a differential mobility analyzer. The particles......The atmospheric partitioning between gas and condensed phase of organic molecules is poorly understood, and discrepancies exist between predicted and observed concentrations of secondary organic aerosols. A key problem is the lack of information about thermodynamic properties of semi- and low...... volatile organic molecules. Saturation vapor pressure and the associated temperature dependence (dH) are key parameters for improving predictive atmospheric models. In this work we combine experiments and thermodynamic modeling to investigate these parameters for a series of polyols, so-called sugar...

  16. Long-Term Stability of Polymer-Coated Surface Transverse Wave Sensors for the Detection of Organic Solvent Vapors.

    Science.gov (United States)

    Stahl, Ullrich; Voigt, Achim; Dirschka, Marian; Barié, Nicole; Richter, Christiane; Waldbaur, Ansgar; Gruhl, Friederike J; Rapp, Bastian E; Rapp, Michael; Länge, Kerstin

    2017-11-03

    Arrays with polymer-coated acoustic sensors, such as surface acoustic wave (SAW) and surface transverse wave (STW) sensors, have successfully been applied for a variety of gas sensing applications. However, the stability of the sensors' polymer coatings over a longer period of use has hardly been investigated. We used an array of eight STW resonator sensors coated with different polymers. This sensor array was used at semi-annual intervals for a three-year period to detect organic solvent vapors of three different chemical classes: a halogenated hydrocarbon (chloroform), an aliphatic hydrocarbon (octane), and an aromatic hydrocarbon (xylene). The sensor signals were evaluated with regard to absolute signal shifts and normalized signal shifts leading to signal patterns characteristic of the respective solvent vapors. No significant time-related changes of sensor signals or signal patterns were observed, i.e., the polymer coatings kept their performance during the course of the study. Therefore, the polymer-coated STW sensors proved to be robust devices which can be used for detecting organic solvent vapors both qualitatively and quantitatively for several years.

  17. An in situ grazing incidence x-ray scattering study of block copolymer thin films during solvent vapor annealing

    Science.gov (United States)

    Gu, Xiaodan; Gunkel, Ilja; Hexemer, Alexander; Russell, Thomas

    2014-03-01

    Although solvent vapor annealing (SVA) has been widely applied to block copolymer (BCP) thin films to obtain well-ordered microdomains, the mechanism of enhancing lateral order is not well understood. Here, we used real time in situ grazing-incidence small-angle x-ray scattering (in situGISAXS) to study the self-assembly of PS-b-P2VP BCP BCPs with different molecular weights thin films in THF vapor, a near neutral solvent for both blocks. Both swelling and deswelling behavior of BCP thin films were examined. The extent of swellingand the solvent removal rate not only affect the domain spacing of BCPs but also dictate the extent of lateral ordering of the BCP microdomains. Larger grains were observed at higher values of the swelling ratio (close to disordering). To preserve the maximal lateral ordering of the microdomains in the swollen state, the fastest solvent removal rate is required to freeze in the ordered microdomain structure of the swollen BCP film. We thanks support from U.S. Department of Energy BES under contract BES-DE-FG02-96ER45612 and ALS doctoral fellowship.

  18. Solvent Vapor Annealing-Mediated Crystallization Directs Charge Generation, Recombination and Extraction in BHJ Solar Cells

    KAUST Repository

    Babics, Maxime; Liang, Ru-Ze; Wang, Kai; Cruciani, Federico; Kan, Zhipeng; Wohlfahrt, Markus; Tang, Ming-Chun; Laquai, Fré dé ric; Beaujuge, Pierre

    2017-01-01

    Small-molecule (SM) donors that can be solution-processed with fullerene acceptors (e.g., PC61/71BM), or their “nonfullerene” counterparts, are proving particularly promising for the realization of high-efficiency bulk-heterojunction (BHJ) solar cells. In several recent studies, solvent vapor annealing (SVA) protocols have been found to yield significant BHJ device efficiency improvements via structural changes in the active layer morphologies. However, the mechanisms by which active layer morphologies evolve when subjected to SVA treatments, and the structural factors impacting charge generation, carrier transport, recombination and extraction in BHJ solar cells with SM donors and fullerene acceptors, remain important aspects to be elucidated. In this report, we show that – in BHJ solar cells with SM donors and fullerene acceptors – selective crystallization promoted by SVA mediates the development of optimized morphologies across the active layers, setting domain sizes and boundaries. Examining BHJ solar cells subjected to various SVA exposure times, with BDT[2F]QdC as the SM donor and PC71BM as the acceptor, we connect those morphological changes to specific carrier effects, showing that crystal growth effectively directs charge generation and recombination. We find that the SM donor-pure domains growing at the expense of a mixed donor-acceptor phase play a determining role, establishing optimum networks with 10-20nm-sized domains during the SVA treatment. Longer SVA times result in highly textured active layers with crystalline domains that can exceed the lengthscale of exciton diffusion, while inducing detrimental vertical morphologies and deep carrier traps. Last, we emphasize the field-dependence charge generation occurring upon SVA-mediated crystallization and link this carrier effect to the mixed phase depletion across the BHJ active layer.

  19. Solvent Vapor Annealing-Mediated Crystallization Directs Charge Generation, Recombination and Extraction in BHJ Solar Cells

    KAUST Repository

    Babics, Maxime

    2017-12-19

    Small-molecule (SM) donors that can be solution-processed with fullerene acceptors (e.g., PC61/71BM), or their “nonfullerene” counterparts, are proving particularly promising for the realization of high-efficiency bulk-heterojunction (BHJ) solar cells. In several recent studies, solvent vapor annealing (SVA) protocols have been found to yield significant BHJ device efficiency improvements via structural changes in the active layer morphologies. However, the mechanisms by which active layer morphologies evolve when subjected to SVA treatments, and the structural factors impacting charge generation, carrier transport, recombination and extraction in BHJ solar cells with SM donors and fullerene acceptors, remain important aspects to be elucidated. In this report, we show that – in BHJ solar cells with SM donors and fullerene acceptors – selective crystallization promoted by SVA mediates the development of optimized morphologies across the active layers, setting domain sizes and boundaries. Examining BHJ solar cells subjected to various SVA exposure times, with BDT[2F]QdC as the SM donor and PC71BM as the acceptor, we connect those morphological changes to specific carrier effects, showing that crystal growth effectively directs charge generation and recombination. We find that the SM donor-pure domains growing at the expense of a mixed donor-acceptor phase play a determining role, establishing optimum networks with 10-20nm-sized domains during the SVA treatment. Longer SVA times result in highly textured active layers with crystalline domains that can exceed the lengthscale of exciton diffusion, while inducing detrimental vertical morphologies and deep carrier traps. Last, we emphasize the field-dependence charge generation occurring upon SVA-mediated crystallization and link this carrier effect to the mixed phase depletion across the BHJ active layer.

  20. Development of a device to valuate the effect of ethanol on the vapor pressure and vaporization enthalpy of fuel gasolines

    OpenAIRE

    Cataluña, Renato; Silva, Rosângela

    2006-01-01

    The quality of the gasoline utilized for fueling internal combustion engines with spark ignition is directly affected by the gasoline's properties. Thus, the fuel's properties must be in perfect equilibrium to allow the engine to perform optimally, not only insofar as fuel consumption is concerned, but also in order to reduce the emission of pollutants. Vapor pressure and vaporization enthalpy are important properties of a gasoline determining the fuel's behavior under different operating con...

  1. HIGH PRESSURE VAPOR-LIQUID EQUILIBRIA OF PALM FATTY ACIDS DISTILLATES-CARBON DIOXIDE SYSTEM

    Directory of Open Access Journals (Sweden)

    Nélio T. MACHADO

    1997-12-01

    Full Text Available Vapor-Liquid equilibria of palm fatty acids distillates/carbon dioxide system has been investigated experimentally at temperatures of 333, 353, and 373 K and pressures of 20, 23, 26, and 29 MPa using the static method. Experimental data for the quasi-binary system palm fatty acids distillates/carbon dioxide has been correlated with Redlich-Kwong-Aspen equation of state. Modeling shows good agreement with experimental data. Selectivity obtained indicates that supercritical carbon dioxide is a reasonable solvent for separating saturated (palmitic acid and unsaturated (oleic+linoleic acids fatty acids from palm fatty acids distillates in a continuous multistage countercurrent column.Foi investigado experimentalmente o equilíbrio líquido-vapor para o sistema Destilado Ácido de Óleo de Palma (PFAD/Dióxido de Carbono, nas temperaturas de 333, 353 e 373 K e pressões de 20, 23, 26 e 29 MPa, usando-se o método estático. Os dados experimentais do sistema pseudo-binário PFAD/CO2 foram correlacionados com a equação de estado de Redlich-Kwong do pacote computacional ASPEN. O modelo reproduz bem os resultados experimentais. A seletividade obtida indica que o CO2 supercrítico é um solvente razoável para a separação em coluna multi-estágio e contínua, do ácido graxo saturado (ácido palmítico daqueles insaturados (ácido oleico e ácido linoleico contidos no PFAD.

  2. Safety limits of half-mask cartridge respirators for organic solvent vapors

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    Recent studies of the effective service life (safety limits) for typical half-mask cartridge respirators have shown these devices to be unsuitable for certain organic vapors, e.g., methanol, methylamine, vinyl chloride, and dichloromethane, because the effective service life is too short. For these vapors other forms of protection such as air-supplied respirators are recommended. The experimentally determined service life for many vapors is shorter--sometimes significantly shorter--than predicted by adsorption theory

  3. Binding Energy, Vapor Pressure and Melting Point of Semiconductor Nanoparticles

    International Nuclear Information System (INIS)

    H. H. Farrell; C. D. Van Siclen

    2007-01-01

    Current models for the cohesive energy of nanoparticles generally predict a linear dependence on the inverse particle diameter for spherical clusters, or, equivalently, on the inverse of the cube root of the number of atoms in the cluster. Although this is generally true for metals, we find that for the group IV semiconductors, C, Si and Ge, this linear dependence does not hold. Instead, using first principles, density functional theory calculations to calculate the binding energy of these materials, we find a quadratic dependence on the inverse of the particle size. Similar results have also been obtained for the metallic group IV elements Sn and Pb. This is in direct contradiction to current assumptions. Further, as a consequence of this quadratic behavior, the vapor pressure of semiconductor nanoparticles rises more slowly with decreasing size than would be expected. In addition, the melting point of these nanoparticles will experience less suppression than experienced by metal nanoparticles with comparable bulk binding energies. This non-linearity also affects sintering or Ostwald ripening behavior of these nanoparticles as well as other physical properties that depend on the nanoparticle binding energy. The reason for this variation in size dependence involves the covalent nature of the bonding in semiconductors, and even in the 'poor' metals. Therefore, it is expected that this result will hold for compound semiconductors as well as the elemental semiconductors

  4. Correlation of chemical evaporation rate with vapor pressure.

    Science.gov (United States)

    Mackay, Donald; van Wesenbeeck, Ian

    2014-09-02

    A new one-parameter correlation is developed for the evaporation rate (ER) of chemicals as a function of molar mass (M) and vapor pressure (P) that is simpler than existing correlations. It applies only to liquid surfaces that are unaffected by the underlying solid substrate as occurs in the standard ASTM evaporation rate test and to quiescent liquid pools. The relationship has a sounder theoretical basis than previous correlations because ER is correctly correlated with PM rather than P alone. The inclusion of M increases the slope of previous log ER versus log P regressions to a value close to 1.0 and yields a simpler one-parameter correlation, namely, ER (μg m(-1) h(-1)) = 1464P (Pa) × M (g mol(-1)). Applications are discussed for the screening level assessment and ranking of chemicals for evaporation rate, such as pesticides, fumigants, and hydrocarbon carrier fluids used in pesticide formulations, liquid consumer products used indoors, and accidental spills of liquids. The mechanistic significance of the single parameter as a mass-transfer coefficient or velocity is discussed.

  5. A reference data set for validating vapor pressure measurement techniques: homologous series of polyethylene glycols

    Science.gov (United States)

    Krieger, Ulrich K.; Siegrist, Franziska; Marcolli, Claudia; Emanuelsson, Eva U.; Gøbel, Freya M.; Bilde, Merete; Marsh, Aleksandra; Reid, Jonathan P.; Huisman, Andrew J.; Riipinen, Ilona; Hyttinen, Noora; Myllys, Nanna; Kurtén, Theo; Bannan, Thomas; Percival, Carl J.; Topping, David

    2018-01-01

    To predict atmospheric partitioning of organic compounds between gas and aerosol particle phase based on explicit models for gas phase chemistry, saturation vapor pressures of the compounds need to be estimated. Estimation methods based on functional group contributions require training sets of compounds with well-established saturation vapor pressures. However, vapor pressures of semivolatile and low-volatility organic molecules at atmospheric temperatures reported in the literature often differ by several orders of magnitude between measurement techniques. These discrepancies exceed the stated uncertainty of each technique which is generally reported to be smaller than a factor of 2. At present, there is no general reference technique for measuring saturation vapor pressures of atmospherically relevant compounds with low vapor pressures at atmospheric temperatures. To address this problem, we measured vapor pressures with different techniques over a wide temperature range for intercomparison and to establish a reliable training set. We determined saturation vapor pressures for the homologous series of polyethylene glycols (H - (O - CH2 - CH2)n - OH) for n = 3 to n = 8 ranging in vapor pressure at 298 K from 10-7 to 5×10-2 Pa and compare them with quantum chemistry calculations. Such a homologous series provides a reference set that covers several orders of magnitude in saturation vapor pressure, allowing a critical assessment of the lower limits of detection of vapor pressures for the different techniques as well as permitting the identification of potential sources of systematic error. Also, internal consistency within the series allows outlying data to be rejected more easily. Most of the measured vapor pressures agreed within the stated uncertainty range. Deviations mostly occurred for vapor pressure values approaching the lower detection limit of a technique. The good agreement between the measurement techniques (some of which are sensitive to the mass

  6. Modeling vapor liquid equilibrium of ionic liquids + gas binary systems at high pressure with cubic equations of state

    Directory of Open Access Journals (Sweden)

    A. C. D. Freitas

    2013-03-01

    Full Text Available Ionic liquids (IL have been described as novel environmentally benign solvents because of their remarkable characteristics. Numerous applications of these solvents continue to grow at an exponential rate. In this work, high pressure vapor liquid equilibria for 17 different IL + gas binary systems were modeled at different temperatures with Peng-Robinson (PR and Soave-Redlich-Kwong (SRK equations of state, combined with the van der Waals mixing rule with two binary interaction parameters (vdW-2. The experimental data were taken from the literature. The optimum binary interaction parameters were estimated by minimization of an objective function based on the average absolute relative deviation of liquid and vapor phases, using the modified Simplex algorithm. The solubilities of all gases studied in this work decrease as the temperature increases and increase with increasing pressure. The correlated results were highly satisfactory, with average absolute relative deviations of 2.10% and 2.25% for PR-vdW-2 and SRK-vdW-2, respectively.

  7. Evaporation monitoring and composition control of alloy systems with widely differing vapor pressures

    International Nuclear Information System (INIS)

    Anklam, T.M.; Berzins, L.V.; Braun, D.G.; Haynam, C.; McClelland, M.A.; Meier, T.

    1994-10-01

    Lawrence Livermore National Laboratory is developing sensors and controls to improve and extend electron beam materials processing technology to alloy systems with constituents of widely varying vapor pressure. The approach under development involves using tunable lasers to measure the density and composition of the vapor plume. A laser based vaporizer control system for vaporization of a uranium-iron alloy has been previously demonstrated in multi-hundred hour, high rate vaporization experiments at LLNL. This paper reviews the design and performance of the uranium vaporization sensor and control system and discusses the extension of the technology to monitoring of uranium vaporization. Data is presented from an experiment in which titanium wire was fed into a molten niobium pool. Laser data is compared to deposited film composition and film cross sections. Finally, the potential for using this technique for composition control in melting applications is discussed

  8. DETERMINATION OF SATURATION VAPOR PRESSURE OF LOW VOLATILE SUBSTANCES THROUGH THE STUDY OF EVAPORATION RATE BY THERMOGRAVIMETRIC ANALYSIS

    Directory of Open Access Journals (Sweden)

    R. V. Ralys

    2015-11-01

    been carried in a stream of nitrogen N2 (20-250 ml·min-1; the duration of evaporation-sublimation (each TGA experiment is 10 hours. As a result, the vapor pressure of these substances has been determined in a wide temperature range; analysis of the dependence for the evaporation coefficients on TGA experiment conditions has been carried out; recommendations on their choice for determination of the enthalpy of vaporization and sublimation of the evaporation rate have been given. Practical Relevance. The presented theoretical and experimental apparatus allows determining the vapor pressure by TGA method for wide classes of compounds with varying volatility (including low volatility. The proposed method requires only necessary data on isothermal evaporation (sublimation and no standards. It is advisable to use this approach for the study of a wide range of high boiling compounds, such as pharmacologically active substances, oils, "green solvents", including ionic liquids, and others.

  9. Determination of Chlorinated Solvent Sorption by Porous Material-Application to Trichloroethene Vapor on Cement Mortar.

    Science.gov (United States)

    Musielak, Marion; Brusseau, Mark L; Marcoux, Manuel; Morrison, Candice; Quintard, Michel

    2014-08-01

    Experiments have been performed to investigate the sorption of trichloroethene (TCE) vapor by concrete material or, more specifically, the cement mortar component. Gas-flow experiments were conducted using columns packed with small pieces of cement mortar obtained from the grinding of typical concrete material. Transport and retardation of TCE at high vapor concentrations (500 mg L -1 ) was compared to that of a non-reactive gas tracer (Sulfur Hexafluoride, SF6). The results show a large magnitude of retardation (retardation factor = 23) and sorption (sorption coefficient = 10.6 cm 3 g -1 ) for TCE, compared to negligible sorption for SF6. This magnitude of sorption obtained with pollutant vapor is much bigger than the one obtained for aqueous-flow experiments conducted for water-saturated systems. The considerable sorption exhibited for TCE under vapor-flow conditions is attributed to some combination of accumulation at the air-water interface and vapor-phase adsorption, both of which are anticipated to be significant for this system given the large surface area associated with the cement mortar. Transport of both SF6 and TCE was simulated successfully with a two-region physical non-equilibrium model, consistent with the dual-medium structure of the crushed cement mortar. This work emphasizes the importance of taking into account sorption phenomena when modeling transport of volatile organic compounds through concrete material, especially in regard to assessing vapor intrusion.

  10. Modified swelling pressure apparatus using vapor pressure technique for compacted bentonite

    International Nuclear Information System (INIS)

    Nishimura, Tomoyoshi

    2012-01-01

    Document available in extended abstract form only. bentonite. The compacted bentonite is found in unsaturated conditions before applying of swelling due to absorption. The behaviour of compacted bentonite is not consistent with the principle and concepts of classical, saturated soil mechanics. An unsaturated soil theoretical framework using soil water characteristic curve has been fairly established over the past several decades. The soil-water characteristic curve is a relationship between soil moisture and soil suction obtained by the axis translation technique, vapor pressure technique or osmotic suction control which is a key feature in unsaturated soil mechanics. The soil-water characteristic curve can be used for prediction of the shear strength, volume change and hydraulic conductivity. Cui et al. 2002 indicated soil-water characteristic curve of expansive clay soil in high soil suction ranges using osmotic suction technique. Tripathy et al. 2010 described the soil-water characteristic curve both using the axis translation technique and vapor pressure technique in the entire soil suction ranges. Nishimura and Koseki 2011 measured suction of bentonite applied high soil suction due vapor pressure using a chilled mirror dew point potentiometer (WP4-T of DECAGON Device). The bentonite with gravimetric water content of 18 % indicated soil suction of 2.8 MPa at least. It is predicted that suction efforts to swelling pressure and shear strength of unsaturated compacted bentonite. This study focuses on the influence of suction on both swelling pressure and shear strength of compacted bentonite. The soil-water characteristic curve (SWCC) tests were conducted for compacted bentonite using both axis-translation technique and vapor pressure technique. The SWCC had a range from 0 kPa to 296 MPa in suction. The compacted bentonite having two different soil suctions were prepared for swelling pressure tests. Newly swelling pressure testing apparatus was developed in order

  11. Pressure and solvent shifts of charge transfer absorption band of iodine complexes

    International Nuclear Information System (INIS)

    Sawamura, Seiji; Taniguchi, Yoshihiro; Suzuki, Keizo

    1979-01-01

    Absorption spectra of the CT band of I 2 complexes were observed in several nonpolar solvents at 1 bar, and in heptane up to 4400 bar. All solvent shifts were red with an increase in (n 2 - 1)/(2n 2 + 1), the refractive index (n) function of solvents, consistent with the solvent shift theory. On the other hand pressure caused a variety of shifts, that is, red shifts in benzene-, toluene-, and mesitylene-I 2 complexes, an inversion shift from red to blue in HMB-I 2 complex, and blue shifts in Et 3 N-, n-Pr 3 N-, and n-Bu 3 N-I 2 complexes, though increase in pressure invariably raises the (n 2 - 1)/(2n 2 + 1) value of solvent. The pressure shifts of I 2 complexes seem to be interpreted by a sum of two effects. One is the increased polarity of the solvent, which causes a red shift. The other is the decrease in the bond distance between a donor and an acceptor, which contributes to a blue shift in a strong CT complex and to a red shift in a week one. The pressure and solvent shifts of I 2 complexes were compared with those of π-donor-TCNE complexes. (author)

  12. Vapor pressure, heat capacities, and phase transitions of tetrakis(tert-butoxy)hafnium

    Czech Academy of Sciences Publication Activity Database

    Fulem, Michal; Růžička, K.

    2011-01-01

    Roč. 311, Dec. (2011), s. 25-29 ISSN 0378-3812 Institutional research plan: CEZ:AV0Z10100521 Keywords : tetrakis(tert-butoxy)hafnium * MO precursor * vapor pressure * heat capacity * vaporization enthalpy * enthalpy of fusion Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.139, year: 2011

  13. Vapor pressures of solid and liquid xanthene and phenoxathiin from effusion and static studies

    Czech Academy of Sciences Publication Activity Database

    Monte, M.J.S.; Santos, L.M.N.B.F.; Sousa, C.A.D.; Fulem, Michal

    2008-01-01

    Roč. 53, č. 8 (2008), s. 1922-1926 ISSN 0021-9568 Institutional research plan: CEZ:AV0Z10100521 Keywords : vapor pressure * xanthene * phenoxanthiin * sublimation and vaporization enthalpy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.063, year: 2008

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

    Science.gov (United States)

    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.

  15. Thermodynamic functions and vapor pressures of uranium and plutonium oxides at high temperatures

    International Nuclear Information System (INIS)

    Green, D.W.; Reedy, G.T.; Leibowitz, L.

    1977-01-01

    The total energy release in a hypothetical reactor accident is sensitive to the total vapor pressure of the fuel. Thermodynamic functions which are accurate at high temperature can be calculated with the methods of statistical mechanics provided that needed spectroscopic data are available. This method of obtaining high-temperature vapor pressures should be greatly superior to the extrapolation of experimental vapor pressure measurements beyond the temperature range studied. Spectroscopic data needed for these calculations are obtained from infrared spectroscopy of matrix-isolated uranium and plutonium oxides. These data allow the assignments of the observed spectra to specific molecular species as well as the calculation of anharmonicities for monoxides, bond angles for dioxides, and molecular geometries for trioxides. These data are then employed, in combination with data on rotational and electronic molecular energy levels, to determine thermodynamic functions that are suitable for the calculation of high-temperature vapor pressures

  16. Vapour pressures and enthalpies of vaporization of a series of the ferrocene derivatives

    International Nuclear Information System (INIS)

    Emel'yanenko, Vladimir N.; Verevkin, Sergey P.; Krol, Olesya V.; Varushchenko, Raisa M.; Chelovskaya, Nelly V.

    2007-01-01

    Vapour pressures of the ferrocene, ferrocene-methanol, benzyl-ferrocene, and benzoyl-ferrocene have been determined by the transpiration method. The molar enthalpies of sublimation Δ cr g H m and of vaporization Δ l g H m have been determined from the temperature dependence of the vapour pressure. The molar enthalpies of fusion of these compounds were measured by d.s.c. The measured data sets of vaporization, sublimation, and fusion enthalpies were checked for internal consistency

  17. Prediction of the vapor pressure and vaporization enthalpy of 1-n-alkyl-3-methylimidazolium-bis-(trifluoromethanesulfonyl) amide ionic liquids.

    Science.gov (United States)

    Diedenhofen, Michael; Klamt, Andreas; Marsh, Kenneth; Schäfer, Ansgar

    2007-09-07

    The vapor pressures and vaporization enthalpies of a series of 1-n-alkyl-3-methylimidazolium-bis-(trifluoromethanesulfonyl) amide ionic liquids have been predicted with two different approaches using the COSMO-RS method and quantum chemical gas phase calculations. While the calculated enthalpies are in good agreement with the experimental data, COSMO-RS seems to underestimate the vapor pressures by roughly 0.5-4 log units dependent on the IL and approach used.

  18. Contribution of water vapor pressure to pressurization of plutonium dioxide storage containers

    Science.gov (United States)

    Veirs, D. Kirk; Morris, John S.; Spearing, Dane R.

    2000-07-01

    Pressurization of long-term storage containers filled with materials meeting the US DOE storage standard is of concern.1,2 For example, temperatures within storage containers packaged according to the standard and contained in 9975 shipping packages that are stored in full view of the sun can reach internal temperatures of 250 °C.3 Twenty five grams of water (0.5 wt.%) at 250 °C in the storage container with no other material present would result in a pressure of 412 psia, which is limited by the amount of water. The pressure due to the water can be substantially reduced due to interactions with the stored material. Studies of the adsorption of water by PuO2 and surface interactions of water with PuO2 show that adsorption of 0.5 wt.% of water is feasible under many conditions and probable under high humidity conditions.4,5,6 However, no data are available on the vapor pressure of water over plutonium dioxide containing materials that have been exposed to water.

  19. Resistive heating enhanced soil vapor extraction of chlorinated solvents from trichloroethylene contaminated silty, low permeable soil

    NARCIS (Netherlands)

    Zutphen, M. van; Heron, G.; Enfield, C.G.; Christensen, T.H.

    1998-01-01

    A 2D-laboratory box experiment (12 x 56 x 116 cm) was conducted to simulate the enhancement of soil vapor extraction by the application of low frequency electrical heating Uoule heating) for the remediation of a low permeable, silty soil contaminated with trichloroethylene. Joule heating enlarged

  20. Indirect Determination of Vapor Pressures by Capillary Gas-Liquid Chromatography: Analysis of the Reference Vapor-Pressure Data and Their Treatment

    Czech Academy of Sciences Publication Activity Database

    Růžička, K.; Koutek, Bohumír; Fulem, M.; Hoskovec, Michal

    2012-01-01

    Roč. 57, č. 5 (2012), s. 1349-1368 ISSN 0021-9568 R&D Projects: GA ČR GA203/09/1327 Institutional research plan: CEZ:AV0Z40550506 Keywords : vapor pressures * capillary gas–liquid chromatography * reference data * relative retention time Subject RIV: CC - Organic Chemistry Impact factor: 2.004, year: 2012

  1. Vapor Pressure Data and Analysis for Selected Organophosphorus Compounds, CMMP, DPMP, DMEP, and DEEP: Extrapolation of High-Temperature Data

    Science.gov (United States)

    2018-04-01

    comparison. The correlation equations are presented using two common units systems , one with temperature given in kelvin (T) and pressure in pascal...This report documents vapor pressure data and correlations for four phosphonate ester compounds that have molecular structures similar to those of...Antoine equation Clausius–Clapeyron equation Enthalpy of vaporization Volatility Differential scanning calorimetry (DSC) Vapor saturation Normal boiling

  2. Distribution of Vapor Pressure in the Vacuum Freeze-Drying Equipment

    Directory of Open Access Journals (Sweden)

    Shiwei Zhang

    2012-01-01

    Full Text Available In the big vacuum freeze-drying equipment, the drying rate of materials is uneven at different positions. This phenomenon can be explained by the uneven distribution of vapor pressure in chamber during the freeze-drying process. In this paper, a mathematical model is developed to describe the vapor flow in the passageways either between material plates and in the channel between plate groups. The distribution of vapor pressure along flow passageway is given. Two characteristic factors of passageways are defined to express the effects of structural and process parameters on vapor pressure distribution. The affecting factors and their actions are quantitatively discussed in detail. Two examples are calculated and analyzed. The analysis method and the conclusions are useful to estimate the difference of material drying rate at different parts in equipment and to direct the choice of structural and process parameters.

  3. Encapsulation of azithromycin into polymeric microspheres by reduced pressure-solvent evaporation method

    DEFF Research Database (Denmark)

    Li, Xiujuan; Chang, Si; Du, Guangsheng

    2012-01-01

    Azithromycin loaded microspheres with blends of poly-l-lactide and ploy-D,L-lactide-co-glycolide as matrices were prepared by the atmosphere-solvent evaporation (ASE) and reduced pressure-solvent evaporation (RSE) method. Both the X-ray diffraction spectra and DSC thermographs demonstrated...... characteristics and release profiles of microspheres. In conclusion, the overall improvement of microspheres in appearance, encapsulation efficiency and controlled drug release through the RSE method could be easily fulfilled under optimal preparation conditions....

  4. The gaseous enthalpy of formation of the ionic liquid 1-butyl-3-methylimidazolium dicyanamide from combustion calorimetry, vapor pressure measurements, and ab initio calculations.

    Science.gov (United States)

    Emel'yanenko, Vladimir N; Verevkin, Sergey P; Heintz, Andreas

    2007-04-04

    Ionic liquids are attracting growing interest as alternatives to conventional molecular solvents. Experimental values of vapor pressure, enthalpy of vaporization, and enthalpy of formation of ionic liquids are the key thermodynamic quantities, which are required for the validation and development of the molecular modeling and ab initio methods toward this new class of solvents. In this work, the molar enthalpy of formation of the liquid 1-butyl-3-methylimidazolium dicyanamide, 206.2 +/- 2.5 kJ.mol-1, was measured by means of combustion calorimetry. The molar enthalpy of vaporization of 1-butyl-3-methylimidazolium dicyanamide, 157.2 +/- 1.1 kJ.mol-1, was obtained from the temperature dependence of the vapor pressure measured using the transpiration method. The latter method has been checked with measurements of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide, where data are available from the effusion technique. The first experimental determination of the gaseous enthalpy of formation of the ionic liquid 1-butyl-3-methylimidazolium dicyanamide, 363.4 +/- 2.7 kJ.mol-1, from thermochemical measurements (combustion and transpiration) is presented. Ab initio calculations of the enthalpy of formation in the gaseous phase have been performed for 1-butyl-3-methylimidazolium dicyanamide using the G3MP2 theory. Excellent agreement with experimental results has been observed. The method developed opens a new way to obtain thermodynamic properties of ionic liquids which have not been available so far.

  5. Solvation-based vapour pressure model for (solvent + salt) systems in conjunction with the Antoine equation

    International Nuclear Information System (INIS)

    Senol, Aynur

    2013-01-01

    Highlights: • Vapour pressures of (solvent + salt) systems have been estimated through a solvation-based model. • Two structural forms of the generalized solvation model using the Antoine equation have been performed. • A simplified concentration-dependent vapour pressure model has been also processed. • The model reliability analysis has been performed in terms of a log-ratio objective function. • The reliability of the models has been interpreted in terms of the statistical design factors. -- Abstract: This study deals with modelling the vapour pressure of a (solvent + salt) system on the basis of the principles of LSER. The solvation model framework clarifies the simultaneous impact of several physical variables such as the vapour pressure of a pure solvent estimated by the Antoine equation, the solubility and solvatochromic parameters of the solvent and the physical properties of the ionic salt. It has been analyzed independently the performance of two structural forms of the generalized model, i.e., a relation depending on an integration of the properties of the solvent and the ionic salt and a relation on a reduced property-basis. A simplified concentration-dependent vapour pressure model has been also explored and implemented on the relevant systems. The vapour pressure data of sixteen (solvent + salt) systems have been processed to analyze statistically the reliability of existing models in terms of a log–ratio objective function. The proposed vapour pressure models match relatively well the observed performance, yielding the overall design factors of 1.066 and 1.073 for the solvation-based models with the integrated and reduced properties, and 1.008 for the concentration-based model, respectively

  6. Tunable and rapid self-assembly of block copolymers using mixed solvent vapors.

    Science.gov (United States)

    Park, Woon Ik; Tong, Sheng; Liu, Yuzi; Jung, Il Woong; Roelofs, Andreas; Hong, Seungbum

    2014-12-21

    Pattern generation of well-controlled block copolymers (BCPs) with a high Flory-Huggins interaction parameter (χ) is important for applications in sub-20 nm nanolithography. We used mixed solvents of dimethylformamide (DMF) and toluene to control the morphology as well as the time to achieve the targeted morphology via self-assembly of BCPs. By precisely controlling the volume ratio of DMF and toluene, well-ordered line, honeycomb, circular hole, and lamellar nanostructures were obtained from a cylinder-forming poly(styrene-b-2-vinylpyridine) (PS-b-P2VP) BCP with high χ. Furthermore, a well-aligned 12 nm line pattern was successfully achieved in the guiding template within one minute using the mixed solvents. This practical method may also be applicable to self-assembly of other BCPs, providing more opportunities for the next-generation sub-10 nm lithography applications.

  7. Effects of copolymer composition, film thickness, and solvent vapor annealing time on dewetting of ultrathin block copolymer films.

    Science.gov (United States)

    Huang, Changchun; Wen, Gangyao; Li, Jingdan; Wu, Tao; Wang, Lina; Xue, Feifei; Li, Hongfei; Shi, Tongfei

    2016-09-15

    Effects of copolymer composition, film thickness, and solvent vapor annealing time on dewetting of spin-coated polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) films (dewetting of the films with different thicknesses occur via the spinodal dewetting and the nucleation and growth mechanisms, respectively. The PS-b-PMMA films rupture into droplets which first coalesce into large ones to reduce the surface free energy. Then the large droplets rupture into small ones to increase the contact area between PMMA blocks and acetone molecules resulting from ultimate migration of PMMA blocks to droplet surface, which is a novel dewetting process observed in spin-coated films for the first time. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Solvent-vapor-assisted dewetting of prepatterned thin polymer films: control of morphology, order, and pattern miniaturization.

    Science.gov (United States)

    Bhandaru, Nandini; Goohpattader, Partho Sarathi; Faruqui, Danish; Mukherjee, Rabibrata; Sharma, Ashutosh

    2015-03-17

    Ultrathin (dewet by the growth of surface instability, the wavelength (λ) of which depends on the film thickness (h(f)). While the dewetting of a flat polymer thin film results in random structures, we show that the dewetting of a prepatterned film results in myriad ordered mesoscale morphologies under specific conditions. Such a film undergoes rupture over the thinnest parts when the initial local thickness of these zones (h(rm)) is lower than a limiting thickness h(lim) ≈ 10 nm. Additionally, the width of the pattern grooves (l(s)) must be wider than λ(s) corresponding to a flat film having a thickness of h(rm) for pattern-directed dewetting to take place over surface-tension-induced flattening. We first present an experimentally obtained morphology phase diagram that captures the conditions where a transition from surface-tension-induced flattening to pattern-directed-rupture takes place. Subsequently, we show the versatility of this technique in achieving a variety of aligned mesopatterns starting from a prepatterned film with simple grating geometry. The morphology of the evolving patterns depends on several parameters such as the initial film thickness (h(f)), prepattern amplitude (h(st)), duration of solvent vapor exposure (SVE), and wettability of the stamp used for patterning. Periodic rupture of the film at regular intervals imposes directionality on the evolving patterns, resulting in isolated long threads/cylindrical ridges of polymers, which subsequently disintegrate into an aligned array of droplets due to Rayleigh-Plateau instability under specific conditions. Other patterns such as a double periodic array of droplets and an array of holes are also possible to obtain. The evolution can be interrupted at any intermediate stage by terminating the solvent vapor annealing, allowing the creation of pattern morphology on demand. The created patterns are significantly miniaturized in size as compared to features obtained from dewetting a flat film with

  9. Liquid-vapor phase transition upon pressure decrease in the lead-bismuth system

    Science.gov (United States)

    Volodin, V. N.

    2009-11-01

    The liquid-vapor phase transitions boundaries were calculated on the basis of the values of vapor pressure of the components in the lead-bismuth system during the stepwise pressure decrease by one order of magnitude from 105 down to 1 Pa. The emergence of azeotropic liquid under pressure lower than 19.3 kPa was ascertained. The emergence of azeotropic mixture near the lead edge of the phase diagram was concluded to be the reason for technological difficulties in the distillation separation of the system into the components in a vacuum.

  10. Prediction of the liquid-vapor equilibrium pressure using the quasi-Gaussian entropy theory

    NARCIS (Netherlands)

    Amadei, A; Roccatano, D; Apol, M.E F; Berendsen, H.J.C.; Di Nola, A.

    1996-01-01

    We derived a method to evaluate the liquid-vapor equilibrium pressure, with high accuracy over a large range of temperature, using the quasi-Gaussian entropy theory. The final expression that we obtain for the equilibrium pressure as a function of the temperature can be considered as a very accurate

  11. The self-similar turbulent flow of low-pressure water vapor

    Science.gov (United States)

    Konyukhov, V. K.; Stepanov, E. V.; Borisov, S. K.

    2018-05-01

    We studied turbulent flows of water vapor in a pipe connecting two closed vessels of equal volume. The vessel that served as a source of water vapor was filled with adsorbent in the form of corundum ceramic balls. These ceramic balls were used to obtain specific conditions to lower the vapor pressure in the source vessel that had been observed earlier. A second vessel, which served as a receiver, was empty of either air or vapor before each vapor sampling. The rate of the pressure increase in the receiver vessel was measured in a series of six samplings performed with high precision. The pressure reduction rate in the source vessel was found to be three times lower than the pressure growth rate in the receiver vessel. We found that the pressure growth rates in all of the adjacent pairs of samples could be arranged in a combination that appeared to be identical for all pairs, and this revealed the existence of a rather interesting and peculiar self-similarity law for the sampling processes under consideration.

  12. Measurement of alkali-vapor emission from pressurized fluidized-bed combustion of Illinois coals

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.H.D.; Teats, F.G.; Swift, W.M. (Argonne National Lab., IL (United States)); Banerjee, D.D. (Illinois Clean Coal Inst., Carterville, IL (United States))

    1993-01-01

    Two Illinois Herrin No. 6 coals and one Illinois Springfield No. 5 coal were separately combusted in a laboratory-scale (15-cm dia) pressurized fluidized-bed combustor (PFBC) combined with an alkali sorber. These coals were combusted in a fluidized bed of Tymochtee dolomite at temperatures ranging from 910 to 950[degree]C and a system pressure of 9.2 atm absolute. Alkali-vapor emission (Na and K) in the PFBC flue gas was determined by the analytical activated-bauxite sorber bed technique developed at Argonne National Laboratory. The test results showed that sodium is the major alkali-vapor species present in the PFBC flue gas, and that the level of sodium-vapor emission increases linearly with both Na and Cl contents in the coals. This suggests that the sodium-vapor emission results from direct vaporization of NaCl present in the coals. The measured alkali-vapor concentration (Na + K), 67 to 190 ppbW, is more than 2.5 times greater than the allowable alkali limit of 24 ppb for an industrial gas turbine. Combusting these coals in a PFBC for power generation may require developing a method to control alkali vapors.

  13. Measurement of alkali-vapor emission from pressurized fluidized-bed combustion of Illinois coals

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.H.D.; Teats, F.G.; Swift, W.M. [Argonne National Lab., IL (United States); Banerjee, D.D. [Illinois Clean Coal Inst., Carterville, IL (United States)

    1993-04-01

    Two Illinois Herrin No. 6 coals and one Illinois Springfield No. 5 coal were separately combusted in a laboratory-scale (15-cm dia) pressurized fluidized-bed combustor (PFBC) combined with an alkali sorber. These coals were combusted in a fluidized bed of Tymochtee dolomite at temperatures ranging from 910 to 950{degree}C and a system pressure of 9.2 atm absolute. Alkali-vapor emission (Na and K) in the PFBC flue gas was determined by the analytical activated-bauxite sorber bed technique developed at Argonne National Laboratory. The test results showed that sodium is the major alkali-vapor species present in the PFBC flue gas, and that the level of sodium-vapor emission increases linearly with both Na and Cl contents in the coals. This suggests that the sodium-vapor emission results from direct vaporization of NaCl present in the coals. The measured alkali-vapor concentration (Na + K), 67 to 190 ppbW, is more than 2.5 times greater than the allowable alkali limit of 24 ppb for an industrial gas turbine. Combusting these coals in a PFBC for power generation may require developing a method to control alkali vapors.

  14. Experimental Results For Hydrocarbon Refrigerant Vaporization In Brazed Plate Heat Exchangers at High Pressure

    OpenAIRE

    Desideri, Adriano; Schmidt Ommen, Torben; Wronski, Jorrit; Quoilin, Sylvain; Lemort, Vincent; Haglind, Fredrik

    2016-01-01

    In this contribution, the experimental heat transfer coefficient  and the pressure drop measured during HFC refrigerants vaporization inside small brazed plate heat exchanger (PHE) at typical evaporation temperature for organic Rankine cycle systems for low thermal energy quality applications are presented. Scientific work focusing on the heat transfer in PHEs has been carried out since the late 19th century. More recent publications have been focusing on vaporization and condensation of ref...

  15. Investigation of the vapor pressure p of zinc bromide or zinc chloride solutions with methanol by static method

    Energy Technology Data Exchange (ETDEWEB)

    Safarov, Javid T. [Heat and Refrigeration Techniques, Azerbaijan Technical University, H. Javid Avn. 25, AZ1073 Baku (Azerbaijan)]. E-mail: javids@azdata.net

    2006-03-15

    Vapor pressures p of ZnBr{sub 2} + CH{sub 3}OH and ZnCl{sub 2} + CH{sub 3}OH solutions at T (298.15 to 323.15) K were measured, activity of solvent a {sub s} and osmotic {phi} coefficients have been evaluated. The experiments were carried out for the ZnBr{sub 2} + CH{sub 3}OH solutions in the molality range m = (0.19972 to 11.05142) mol . kg{sup -1} and for the ZnCl{sub 2} + CH{sub 3}OH solutions in the molality range m (0.42094 to 8.25534) mol . kg{sup -1}. The Antoine equation for the empirical description of the experimental vapor pressure results and the Pitzer-Mayorga model with inclusion of ionic strength dependence of the third virial coefficient for the description of calculated osmotic coefficients were used. The parameters of Pitzer-Mayorga model were used for evaluation of activity coefficients.

  16. Screening for organic solvents in Hanford waste tanks using total non- methane organic compound vapor concentrations

    International Nuclear Information System (INIS)

    Huckaby, J.L.; Glissmeyer, J.A.; Sklarew, D.S.

    1997-02-01

    The potential ignition of organic liquids stored in the Hanford high-level radioactive waste tanks is a safety issue because expanding gases could affect tank dome integrity. This report presents results of a screening test that was applied to 75 passively ventilated waste tanks at Hanford to determine those that might contain a significant amount of organic liquid waste. The screening test is based on a simple model of tank headspace, headspace organic vapor concentrations, and certain tank physical parameters. Analyses indicate that damage to the tank dome is credible only if the organic liquid burn rate is above a threshold value, and this can occur only if the surface area of organic liquid in a tank is above a corresponding threshold value of about one square meter. Twelve tanks were identified as potentially containing at least that amount of semivolatile organic liquid based on conservative estimates. Tank head space organic vapor concentrations and physical parameters required by the screening test have been compiled and are presented for each of the tanks studied. Estimates of the ventilation rates of the waste tanks were revised to reflect recent information obtained from hydrogen monitoring data. A simple analysis of the uncertainty in the test results suggests that the largest current uncertainty in the estimation of organic liquid surface area is that associated with knowledge of the tank ventilation rate. The uncertainty analysis is applied to determine 95% confidence limits for the estimated organic waste surface area in each tank

  17. Analytical model for the design of in situ horizontal permeable reactive barriers (HPRBs) for the mitigation of chlorinated solvent vapors in the unsaturated zone

    NARCIS (Netherlands)

    Verginelli, Iason; Capobianco, Oriana; Hartog, Niels; Baciocchi, Renato

    In this work we introduce a 1-D analytical solution that can be used for the design of horizontal permeable reactive barriers (HPRBs) as a vapor mitigation system at sites contaminated by chlorinated solvents. The developed model incorporates a transient diffusion-dominated transport with a

  18. The vaporization enthalpies and vapor pressures of fatty acid methyl esters C18, C21 to C23, and C25 to C29 by correlation - gas chromatography

    International Nuclear Information System (INIS)

    Chickos, James S.; Zhao Hui; Nichols, Gary

    2004-01-01

    Vapor pressures and vaporization enthalpies for methyl heptadecanoate and methyl heneicosanoate to methyl octacosanoate exclusive of methyl tricosanoate are evaluated as a function of temperature over the temperature range T = 298.15-450 K by correlation gas chromatography. The results are generated by an extrapolative process using literature values for methyl tetradecanoate to methyl eicosanoate as standards. Relationships for calculating vapor pressures of the title compounds from T = 298.15 to 450 K are provided. Experimental fusion enthalpies are also reported for the methyl esters from methyl hexadecanoate to methyl octacosanoate excluding methyl tridecanoate. Vaporization enthalpies and fusion enthalpies adjusted for temperature to T = 298.15 K are combined to provide sublimation enthalpies. The results are compared to available literature values. A rationale for the linear relationship observed between enthalpies of vaporization and enthalpies of transfer from solution to the vapor is also provided

  19. Effect of temperature on the transport of solvents through PTMSP under ultra-high pressures

    International Nuclear Information System (INIS)

    Grekhov, A M; Belogorlov, A A; Eremin, Yu S; Pastukhova, E V; Yushkin, A A; Volkov, A V

    2016-01-01

    Despite a large number of studies, by now there is no any definitive explanation of the solvent transport mechanism in nanostructured polymer materials. Both convective and diffusive transport of solvents can be observed in these materials. The study of the solvents permeability at different temperatures and pressures allow the variation of the physical parameters and structure of the solvent-membrane interaction thus becoming the key factor in the understanding of the fundamental aspects of the selective transport process in nanostructured polymer membranes. The paper presents the study of ethanol, propanol and water transport through poly [1- (trimethylsilyl)-l-propine] (PTMSP) at pressures 50-150 atm and temperature up to 90°C. The study was done by the method of pressure dynamic decay. As the temperature rises, the permeability of ethanol and propanol through PTMSP is shown to increase in proportion to decreasing viscosity that denotes a convective type of transport. As for water, the permeability change is thermo-activated that is typical for a diffusive type of transport. This difference in the transport characteristics can be related to a change in the membrane structure and energetic characteristics of the solvent-polymer interaction. (paper)

  20. Quantitative structure-property relationships for prediction of boiling point, vapor pressure, and melting point.

    Science.gov (United States)

    Dearden, John C

    2003-08-01

    Boiling point, vapor pressure, and melting point are important physicochemical properties in the modeling of the distribution and fate of chemicals in the environment. However, such data often are not available, and therefore must be estimated. Over the years, many attempts have been made to calculate boiling points, vapor pressures, and melting points by using quantitative structure-property relationships, and this review examines and discusses the work published in this area, and concentrates particularly on recent studies. A number of software programs are commercially available for the calculation of boiling point, vapor pressure, and melting point, and these have been tested for their predictive ability with a test set of 100 organic chemicals.

  1. Simple Apparatus for the Measurement of Total Pressure of Polymer + Solvent Mixtures.

    Czech Academy of Sciences Publication Activity Database

    Pavlíček, Jan; Bogdanić, Grozdana; Wichterle, Ivan

    2017-01-01

    Roč. 40, č. 5 (2017), s. 991-996 ISSN 0930-7516. [International Congress of Chemical and Process Engineering CHISA 2016 /22./ and the 19th Conference PRES 2016. Prague, 27.08.2016-31.08.2016] R&D Projects: GA ČR GA15-19542S Institutional support: RVO:67985858 Keywords : vapor-liquid equilibrium * polymer-solvent systems * static cells Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 2.051, year: 2016

  2. Determination of the solid-liquid-vapor triple point pressure of carbon

    International Nuclear Information System (INIS)

    Haaland, D.M.

    1976-01-01

    A detailed experimental study of the triple point pressure of carbon using laser heating techniques has been completed. Uncertainties and conflict in previous investigations have been addressed and substantial data presented which places the solid-liquid-vapor carbon triple point at 107 +- 2 atmospheres. This is in agreement with most investigations which have located the triple point pressure between 100 and 120 atmospheres, but is in disagreement with recent low pressure carbon experiments. The absence of any significant polymorphs of carbon other than graphite suggests that the graphite-liquid-vapor triple point has been measured. Graphite samples were melted in a pressure vessel using a 400 W Nd:YAG continuous-wave laser focused to a maximum power density of approximately 80 kW/cm 2 . Melt was confirmed by detailed microstructure analysis and x-ray diffraction of the recrystallized graphite. Experiments to determine the minimum melt pressure of carbon were completed as a function of sample size, type of inert gas, and laser power density to asure that laser power densities were sufficient to produce melt at the triple point pressure of carbon, and the pressure of carbon at the surface of the sample was identical to the measured pressure of the inert gas in the pressure vessel. High-speed color cinematography of the carbon heating revealed the presence of a laser-generated vapor or particle plume in front of the sample. The existence of this bright plume pevented the measurement of the carbon triple point temperature

  3. Extraction of bitter acids from hops and hop products using pressurized solvent extraction (PSE)

    Czech Academy of Sciences Publication Activity Database

    Čulík, J.; Jurková, M.; Horák, T.; Čejka, P.; Kellner, V.; Dvořák, J.; Karásek, Pavel; Roth, Michal

    2009-01-01

    Roč. 115, č. 3 (2009), s. 220-225 ISSN 0046-9750 R&D Projects: GA ČR GA203/08/1536; GA MŠk 1M0570 Institutional research plan: CEZ:AV0Z40310501 Keywords : hops * bitter acids * pressurized solvent extraction Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 1.000, year: 2009

  4. HIGH-PRESSURE VAPOR-LIQUID EQUILIBRIUM DATA FOR BINARY AND TERNARY SYSTEMS FORMED BY SUPERCRITICAL CO2, LIMONENE AND LINALOOL

    Directory of Open Access Journals (Sweden)

    MELO S. A. B. VIEIRA DE

    1999-01-01

    Full Text Available The feasibility of deterpenating orange peel oil with supercritical CO2 depends on relevant vapor-liquid equilibrium data because the selectivity of this solvent for limonene and linalool (the two key components of the oil is of crucial importance. The vapor-liquid equilibrium data of the CO2-limonene binary system was measured at 50, 60 and 70oC and pressures up to 10 MPa, and of the CO2-linalool binary system at 50oC and pressures up to 85 bar. These results were compared with published data when available in the literature. The unpublished ternary phase equilibrium of CO2-limonene-linalool was studied at 50oC and up to 9 MPa. Selectivities obtained using these ternary data were compared with those calculated using binary data and indicate that a selective separation of limonene and linalool can be achieved.

  5. Thermodynamic consistency of vapor pressure and calorimetric data for argon, krypton, and xenon

    International Nuclear Information System (INIS)

    Schwalbe, L.A.; Crawford, R.K.; Chen, H.H.; Aziz, R.A.

    1977-01-01

    A new two-parameter vapor pressure equation has been derived which, unlike the Salter equation, is shown to be equally applicable to quantum or classical solids and even liquids. The condensed phase enthalpies and entropies are given directly by the fitted parameters with accuracies comparable to those which have been claimed for existing independent calorimetric measurements. Recent vapor pressure data for the solid and liquid phases of argon, krypton, and xenon are analyzed in this manner, and the results are compared with the available calorimetric data. New values for the cohesive energy at T=0 are also derived for these substances

  6. The effect of deuterium substitution on the vapor pressure of acetonitrile

    International Nuclear Information System (INIS)

    Jancso, G.; Jakli, Gy.; Koritsanszky, T.

    1980-01-01

    The vapor pressure difference between CH 3 CN and CD 3 CN was measured by differential capacitance manometry between -40 and +80 deg C. The vapor pressure isotope effects (VPIE) derived from the results may be expressed by the equation: ln(psub(H)/Psub(D))=871.761/T 2 -13.577/T+0.006874. The experimental data were interpreted within the framework of the statistical theory of isotope effects in condensed systems. The largest contribution to the VPIE arises from the shifts in the CH stretching vibrations resulting from condensation which were found to be temperature dependent in good agreement with the available spectroscopic information. (author)

  7. Relationship between the evaporation rate and vapor pressure of moderately and highly volatile chemicals.

    Science.gov (United States)

    van Wesenbeeck, Ian; Driver, Jeffrey; Ross, John

    2008-04-01

    Volatilization of chemicals can be an important form of dissipation in the environment. Rates of evaporative losses from plant and soil surfaces are useful for estimating the potential for food-related dietary residues and operator and bystander exposure, and can be used as source functions for screening models that predict off-site movement of volatile materials. A regression of evaporation on vapor pressure from three datasets containing 82 pesticidal active ingredients and co-formulants, ranging in vapor pressure from 0.0001 to >30,000 Pa was developed for this purpose with a regression correlation coefficient of 0.98.

  8. The vapor pressure and vaporization enthalpy of R-(+)-menthofuran, a hepatotoxin metabolically derived from the abortifacient terpene, (R)-(+)-pulegone by correlation gas chromatography

    International Nuclear Information System (INIS)

    Gobble, Chase; Chickos, James S.

    2016-01-01

    Highlights: • The vaporization enthalpy and vapor pressure of R-(+) menthofuran is evaluated. • The normal boiling temperature is predicted and compared to experimental and predicted values. • A vapor pressure equation as a function of temperature for menthofuran is evaluated. - Abstract: The vapor pressure as a function of temperature and its vaporization enthalpy at T = 298.15 K of R-(+)-menthofuran, a substance metabolically derived from R-(+)-pulegone that is both a flavoring agent at low concentrations and a hepatotoxin at larger ones, is evaluated by correlation-gas chromatography. A vapor pressure p/Pa = (36 ± 12) has been evaluated at T = 298.15 K, and a normal boiling temperature of T_b/K = 482.4 K is predicted. A boiling temperature of T_b/K = 374.3 compares with the literature value of T_b/K = 371.2 at reduced pressure, p/kPa = 2.93. The vaporization enthalpy of (56.5 ± 3.0) kJ·mol"−"1 compares to an estimated value of (57.8 ± 2.9) kJ·mol"−"1.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hyeon-Deuk, Kim, E-mail: kim@kuchem.kyoto-u.ac.jp [Department of Chemistry, Kyoto University, Kyoto 606-8502 (Japan); Japan Science and Technology Agency, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan); Ando, Koji [Department of Chemistry, Kyoto University, Kyoto 606-8502 (Japan)

    2015-11-07

    Nuclear quantum effects play a dominant role in determining the phase diagram of H{sub 2}. With a recently developed quantum molecular dynamics simulation method, we examine dynamical and structural characters of solid H{sub 2} under vapor pressure, demonstrating the difference from liquid and high-pressure solid H{sub 2}. 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 H{sub 2} 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 H{sub 2} solid will be useful in monitoring thermodynamic states of condensed hydrogens.

  10. Measurement and modeling of high-pressure (vapor + liquid) equilibria of (CO2 + alkanol) binary systems

    International Nuclear Information System (INIS)

    Bejarano, Arturo; Gutierrez, Jorge E.; Araus, Karina A.; Fuente, Juan C. de la

    2011-01-01

    Research highlights: → (Vapor + liquid) equilibria of three (CO 2 + C 5 alcohol) binary systems were measured. → Complementary data are reported at (313, 323 and 333) K and from (2 to 11) MPa. → No liquid immiscibility was observed at the temperatures and pressures studied. → Experimental data were correlated with the PR-EoS and the van de Waals mixing rules. → Correlation results showed relative deviations ≤8 % (liquid) and ≤2 % (vapor). - Abstract: Complementary isothermal (vapor + liquid) equilibria data are reported for the (CO 2 + 3-methyl-2-butanol), (CO 2 + 2-pentanol), and (CO 2 + 3-pentanol) binary systems at temperatures of (313, 323, and 333) K, and at pressure range of (2 to 11) MPa. For all (CO 2 + alcohol) systems, it was visually monitored that there was no liquid immiscibility at the temperatures and pressures studied. The experimental data were correlated with the Peng-Robinson equation of state using the quadratic mixing rules of van der Waals with two adjustable parameters. The calculated (vapor + liquid) equilibria compositions were found to be in good agreement with the experimental data with deviations for the mole fractions <8% and <2% for the liquid and vapor phase, respectively.

  11. The development of substitute inks and controls for reducing workplace concentrations of organic solvent vapors in a vinyl shower curtain printing plant.

    Science.gov (United States)

    Piltingsrud, Harley V; Zimmer, Anthony T; Rourke, Aaron B

    2003-08-01

    During the summer of 1994, football players at a practice field reported noxious odors in the area. Ohio Environmental Protection Agency (OEPA) investigations of industries surrounding the field included a printing facility producing vinyl shower curtains with screen-printed designs. Though not the source of the odor, they were discharging volatile organic compounds directly to the environs in violation of OEPA regulations. To achieve compliance they installed a catalytic oxidizer for treating discharged air. Due to high equipment costs, the capacity of the installed catalytic oxidizer resulted in a substantial reduction in discharged air flow rates and increased solvent vapor concentrations within the workplace. Vapor levels caused worker discomfort, prompting a request for assistance from the Ohio Bureau of Workers Compensation. The vapor concentrations were found to exceed NIOSH, OSHA, and ACGIH acceptable exposure levels. The workers were then required to wear organic vapor removing respirators full-time while printing as a temporary protective measure. The company requested NIOSH assistance in finding methods to reduce solvent vapor concentrations. NIOSH studies included the identification of the sources and relative magnitude of solvent emissions from the printing process, the design of controls for the emissions, and the development of substitute inks using non-photochemically reactive solvents. The new ink system and controls allowed OEPA removal of the requirement for the treatment of discharged air and substantial increases in dilution ventilation. Increased ventilation would permit reduction in worker exposures to less than 1/3 mixture TLV levels and removal of requirements for respirator usage. This solution was the result of a comprehensive review of all facets of the problem, including OEPA regulations. It also required cooperative work between the company and federal, state, and local governmental agencies.

  12. Numerical simulation of vapor flow and pressure drop across the demister of MSF desalination plant

    International Nuclear Information System (INIS)

    Janajreh, I.; Hasania, A.; Fath, H.

    2013-01-01

    Highlights: ► Porous media was used to simulate the pressure drop across desalination demister. ► Simulation results plausibly compared with experimental results. ► FC inlet Velocity distribution has no effect on the demister pressure drop. ► Demister inertial resistance affects pressure drop more than viscous resistance. - Abstract: This paper presents a numerical simulation of the water vapor flow in an MSF flash chamber along with the pressure drop across the demister. The demister is a simple porous blanket of metal wires mesh (usually made of stainless steel wires) which retains liquid droplets entrained by the vapor momentum to enhance the quality of the product water. Two main areas of concern in wire mesh mist eliminators are; (i) the pressure drop and (ii) the mist removal efficiency. The present simulation focuses only on the pressure drop across the demister. The simulation is carried out considering a full scale flashing chamber of a typical operational MSF desalination plant and of a real industrial demister dimensions. The study simulates the demister as porous media flow. It takes into account the vapor velocity, the dimension of the demister, its porosity and wire thickness. The obtained pressure drop was found to be within a reasonable agreement with the published literature data and it follows a trend compatible with Ergun’s equation as well as the empirical correlation of Svendsen.

  13. Vapour pressure and enthalpy of vaporization of aliphatic poly-amines

    International Nuclear Information System (INIS)

    Efimova, Anastasia A.; Emel'yanenko, Vladimir N.; Verevkin, Sergey P.; Chernyak, Yury

    2010-01-01

    Molar enthalpies of vaporization of aliphatic poly-amines: 1,4-dimethylpiperazine [106-58-1], 1-(2-aminoethyl)-piperazine, [140-31-8], 1-(2-aminoethyl)-4-methyl-piperazine [934-98-5], and triethylenetetramine [112-24-3] were obtained from the temperature dependence of the vapour pressure measured by the transpiration method. A large number of the primary experimental results on temperature dependences of vapour pressures of the parent compounds have been collected from the literature and have been treated uniformly in order to derive vaporization enthalpies of poly-amines at the reference temperature 298.15 K. An internal consistency check was performed on enthalpy of vaporization values for poly-amines studied in this work.

  14. Sex differences in the toxicokinetics of inhaled solvent vapors in humans 2. 2-propanol

    International Nuclear Information System (INIS)

    Ernstgaard, Lena; Sjoegren, Bengt; Warholm, Margareta; Johanson, Gunnar

    2003-01-01

    The aim of this study was to evaluate possible sex differences in the inhalation toxicokinetics of 2-propanol vapor. Nine women and eight men were exposed on different occasions for 2 h during light physical exercise (50 W) to 2-propanol (350 mg/m 3 ) and to clean air (control exposure). The level corresponds to the Swedish occupational exposure limit. 2-Propanol and its metabolite acetone were monitored up to 24 h after exposure in exhaled air, blood, saliva, and urine by headspace gas chromatography. Body fat and lean body mass were estimated from sex-specific equations using bioelectrical impedance, body weight, height, and age. Genotypes were determined by PCR-based assays for alcohol dehydrogenase and cytochrome P450 2E1 (CYP2E1). The CYP2E1 phenotype was assessed by the 2-h plasma 6-hydroxychlorzoxazone/chlorzoxazone metabolic ratio in vivo. The toxicokinetic profile in blood was analyzed using a one-compartment population model. The following sex differences were significant at the p 0.05 level (Student's t test). The respiratory uptake was lower and the volume of distribution smaller in females. The women had a slightly shorter half-time of 2-propanol in blood and a higher apparent total clearance when corrected for body composition. However, women reached approximately four times higher 2-propanol levels in exhaled air at 10-min postexposure and onward. Acetone in blood was markedly higher in females than in males in the control experiment and slightly higher following exposure to 2-propanol. A marked sex difference was that of a 10-fold higher in vivo blood:breath ratio in men, suggesting sex differences in the lung metabolism of 2-propanol. The most marked sex difference was that of salivary acetone, for which an approximately 100-fold increase was seen in women, but no increase in men, after exposure to 2-propanol compared to clean air. The toxicokinetic analysis revealed no significant differences in toxicokinetics between subjects of different

  15. Low-pressure chemical vapor deposition as a tool for deposition of thin film battery materials

    NARCIS (Netherlands)

    Oudenhoven, J.F.M.; Dongen, van T.; Niessen, R.A.H.; Croon, de M.H.J.M.; Notten, P.H.L.

    2009-01-01

    Low Pressure Chemical Vapor Deposition was utilized for the deposition of LiCoO2 cathode materials for all-solid-state thin-film micro-batteries. To obtain insight in the deposition process, the most important process parameters were optimized for the deposition of crystalline electrode films on

  16. Vapour pressures and enthalpies of vaporization of a series of the linear n-alkyl acetates

    Czech Academy of Sciences Publication Activity Database

    Krasnykh, E. L.; Verevkin, S. P.; Koutek, Bohumír; Doubský, Jan

    2006-01-01

    Roč. 38, č. 6 (2006), s. 717-723 ISSN 0021-9614 Institutional research plan: CEZ:AV0Z40550506 Keywords : aliphatic acetates * transpiration method * vapour pressure * enthalpy of vaporization Subject RIV: CC - Organic Chemistry Impact factor: 1.842, year: 2006

  17. Recommended vapor pressures for aniline, nitromethane, 2-aminoethanol, and 1-methyl-2-pyrrolidone

    Czech Academy of Sciences Publication Activity Database

    Růžička, K.; Fulem, Michal; Mahnel, T.; Červinka, C.

    2015-01-01

    Roč. 406, Nov (2015), 34-46 ISSN 0378-3812 Institutional support: RVO:68378271 Keywords : recommended vapor pressure equations * heat capacity * ideal - gas thermodynamic properties * aniline * nitromethane Subject RIV: BJ - Thermodynamics Impact factor: 1.846, year: 2015

  18. Effect of Preferential Solvation of Polymer Chains on Vapor-Pressure Osmometry Results. Computer Simulation Study.

    Czech Academy of Sciences Publication Activity Database

    Svoboda, Martin; Lísal, Martin; Limpouchová, Z.; Procházka, Karel

    2018-01-01

    Roč. 23, č. 3 (2018), s. 244-251 ISSN 1023-666X R&D Projects: GA ČR GA15-19542S Institutional support: RVO:67985858 Keywords : vapor-pressure osmometry * simulation * solvatation Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry

  19. Interaction enthalpies of solid human serum albumin with water-dioxane mixtures: comparison with water and organic solvent vapor sorption

    International Nuclear Information System (INIS)

    Sirotkin, Vladimir A.; Faizullin, Djihanguir A.

    2004-01-01

    Enthalpy changes (ΔH tot ) on the immersion of dehydrated human serum albumin (HSA) into water-dioxane mixtures have been measured using a Setaram BT-2.15 calorimeter at 298 K. Thermodynamic activity of water was varied from 0 to 1. Calorimetric results are discussed together with the FTIR-spectroscopic data on water and organic solvent vapor adsorption/desorption isotherms on solid HSA. Dioxane sorption exhibits a pronounced hysteresis. Calorimetric and dioxane desorption dependencies consist of two parts. No dioxane sorption was observed in low water activity region (a w tot values are close to zero. At water activity about 0.5 the sharp exothermic drop of the interaction enthalpy values was observed. This exothermic drop is accompanied by the sharp increase in the amount of sorbed dioxane and additional water sorption (compared with that for pure water). Dioxane adsorption branch resembles a smooth curve. In this case, solid HSA binds more than 300 mol dioxane/mol HSA at low water activities. By using a water activity-based comparison we distinguished between dioxane-assisted and dioxane-competitive effect on water sorption. The obtained results demonstrate that the hydration 'history' of solid protein is an important factor that controls as the state of protein macromolecule as well as the sorption of low-molecular organic molecules

  20. Origin of Reduced Open-Circuit Voltage in Highly Efficient Small-Molecule-Based Solar Cells upon Solvent Vapor Annealing.

    Science.gov (United States)

    Deng, Wanyuan; Gao, Ke; Yan, Jun; Liang, Quanbin; Xie, Yuan; He, Zhicai; Wu, Hongbin; Peng, Xiaobin; Cao, Yong

    2018-03-07

    In this study, we demonstrate that remarkably reduced open-circuit voltage in highly efficient organic solar cells (OSCs) from a blend of phenyl-C 61 -butyric acid methyl ester and a recently developed conjugated small molecule (DPPEZnP-THD) upon solvent vapor annealing (SVA) is due to two independent sources: increased radiative recombination and increased nonradiative recombination. Through the measurements of electroluminescence due to the emission of the charge-transfer state and photovoltaic external quantum efficiency measurement, we can quantify that the open-circuit voltage losses in a device with SVA due to the radiative recombination and nonradiative recombination are 0.23 and 0.31 V, respectively, which are 0.04 and 0.07 V higher than those of the as-cast device. Despite of the reduced open-circuit voltage, the device with SVA exhibited enhanced dissociation of charge-transfer excitons, leading to an improved short-circuit current density and a remarkable power conversion efficiency (PCE) of 9.41%, one of the best for solution-processed OSCs based on small-molecule donor materials. Our study also clearly shows that removing the nonradiative recombination pathways and/or suppressing energetic disorder in the active layer would result in more long-lived charge carriers and enhanced open-circuit voltage, which are prerequisites for further improving the PCE.

  1. Pressure of saturated vapor of yttrium and zirconium acetylacetonates

    Energy Technology Data Exchange (ETDEWEB)

    Trembovetskij, G.V.; Berdonosov, S.S.; Murav' eva, I.A.; Martynenko, L.I. (Moskovskij Gosudarstvennyj Univ. (USSR))

    1984-08-01

    The static method and the flow method using /sup 91/Y and /sup 95/Zr radioactive indicators have been applied to determine pressure of saturated vapour of yttrium and zirconium acetylacetonates. Values of thermodynamic functions ..delta..Hsub(subl)=(98+-16)kJ/mol and ..delta..Ssub(subl.)=(155+-30)J/mol x K are calculated for sublimation of yttrium acetylacetonate. For sublimation of zirconium acetylacetonates ..delta..Hsub(subl) equals (116+-38) kJ/mol and ..delta..Ssub(subl) is equal to (198+-65) J/molxK.

  2. Effect of Pressure on Absorption Spectra of Lycopene in n-Hexane and CS2 Solvents

    Science.gov (United States)

    Zhang, Wei; Liu, Wei-Long; Zheng, Zhi-Ren; Huo, Ming-Ming; Li, Ai-Hua; Yang, Bin

    2010-01-01

    The absorption spectra of lycopene in n-hexane and CS2 are measured under high pressure and the results are compared with β-carotene. In the lower pressure range, the deviation from the linear dependence on the Bayliss parameter (BP) for β-carotene is more visible than that for lycopene. With the further increase of the solvent BP, the 0-0 bands of lycopene and β-carotene red shift at almost the same rate in n-hexane; however, the 0-0 band of lycopene red shifts slower than that of β-carotene in CS2. The origins of these diversities are discussed taking into account the dispersion interactions and structures of solute and solvent molecules.

  3. Effect of Pressure on Absorption Spectra of Lycopene in n-Hexane and CS2 Solvents

    International Nuclear Information System (INIS)

    Wei, Zhang; Wei-Long, Liu; Zhi-Ren, Zheng; Ming-Ming, Huo; Ai-Hua, Li; Bin, Yang

    2010-01-01

    The absorption spectra of lycopene in n-hexane and CS 2 are measured under high pressure and the results are compared with β-carotene. In the lower pressure range, the deviation from the linear dependence on the Bayliss parameter (BP) for β-carotene is more visible than that for lycopene. With the further increase of the solvent BP, the 0–0 bands of lycopene and β-carotene red shift at almost the same rate in n-hexane; however, the 0–0 band of lycopene red shifts slower than that of β-carotene in CS 2 . The origins of these diversities are discussed taking into account the dispersion interactions and structures of solute and solvent molecules. (atomic and molecular physics)

  4. Determination of vapor pressures, enthalpies of sublimation, and enthalpies of fusion of benzenetriols

    International Nuclear Information System (INIS)

    Verevkin, Sergey P.; Schick, Christoph

    2004-01-01

    Molar enthalpies of sublimation of 1,2,4-, 1,2,3-, and 1,3,5-tri-hydroxy-benzene, were obtained from the temperature dependence of the vapor pressure measured by the transpiration method. The molar enthalpies of fusion and molar heat capacities of these compounds were measured by DSC. The measured data sets of vaporization, sublimation and fusion enthalpies were checked for internal consistency. Strength of the inter- and intra-molecular hydrogen bonding in di- and tri-hydroxy-benzenes have been assessed

  5. Vapor pressure determination of liquid UO/sub 2/ using a boiling point technique

    International Nuclear Information System (INIS)

    Bober, M.; Singer, J.

    1987-01-01

    By analogy with the classic boiling point method, a quasi-stationary millisecond laser-heating technique was applied to measure the saturated vapor pressure curve of liquid UO/sub 2/ in the temperature range of 3500 to 4500 K. The results are represented by log rho (MPa)=5.049 - 23 042/T (K), which gives an average heat of vaporization of 441 kJ/mol and a normal boiling point of 3808 K. In addition, spectral emissivities of liquid UO/sub 2/ were determined as a function of the temperature at the pyrometer wavelengths of 752 and 1064 nm

  6. Thermal-hydraulic behaviors of vapor-liquid interface due to arrival of a pressure wave

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Akira; Fujii, Yoshifumi; Matsuzaki, Mitsuo [Tokyo Institute of Technology (Japan)

    1995-09-01

    In the vapor explosion, a pressure wave (shock wave) plays a fundamental role for triggering, propagation and enhancement of the explosion. Energy of the explosion is related to the magnitude of heat transfer rate from hot liquid to cold volatile one. This is related to an increasing rate of interface area and to an amount of transient heat flux between the liquids. In this study, the characteristics of transient heat transfer and behaviors of vapor film both on the platinum tube and on the hot melt tin drop, under same boundary conditions have been investigated. It is considered that there exists a fundamental mechanism of the explosion in the initial expansion process of the hot liquid drop immediately after arrival of pressure wave. The growth rate of the vapor film is much faster on the hot liquid than that on the solid surface. Two kinds of roughness were observed, one due to the Taylor instability, by rapid growth of the explosion bubble, and another, nucleation sites were observed at the vapor-liquid interface. Based on detailed observation of early stage interface behaviors after arrival of a pressure wave, the thermal fragmentation mechanism is proposed.

  7. Atmospheric pressure plasma enhanced chemical vapor deposition of zinc oxide and aluminum zinc oxide

    International Nuclear Information System (INIS)

    Johnson, Kyle W.; Guruvenket, Srinivasan; Sailer, Robert A.; Ahrenkiel, S. Phillip; Schulz, Douglas L.

    2013-01-01

    Zinc oxide (ZnO) and aluminum-doped zinc oxide (AZO) thin films were deposited via atmospheric pressure plasma enhanced chemical vapor deposition. A second-generation precursor, bis(1,1,1,5,5,5-hexafluoro-2,4-pentanedionato)(N,N′-diethylethylenediamine) zinc, exhibited significant vapor pressure and good stability at one atmosphere where a vaporization temperature of 110 °C gave flux ∼ 7 μmol/min. Auger electron spectroscopy confirmed that addition of H 2 O to the carrier gas stream mitigated F contamination giving nearly 1:1 metal:oxide stoichiometries for both ZnO and AZO with little precursor-derived C contamination. ZnO and AZO thin film resistivities ranged from 14 to 28 Ω·cm for the former and 1.1 to 2.7 Ω·cm for the latter. - Highlights: • A second generation precursor was utilized for atmospheric pressure film growth. • Addition of water vapor to the carrier gas stream led to a marked reduction of ZnF 2 . • Carbonaceous contamination from the precursor was minimal

  8. Effect of superficial velocity on vaporization pressure drop with propane in horizontal circular tube

    Science.gov (United States)

    Novianto, S.; Pamitran, A. S.; Nasruddin, Alhamid, M. I.

    2016-06-01

    Due to its friendly effect on the environment, natural refrigerants could be the best alternative refrigerant to replace conventional refrigerants. The present study was devoted to the effect of superficial velocity on vaporization pressure drop with propane in a horizontal circular tube with an inner diameter of 7.6 mm. The experiments were conditioned with 4 to 10 °C for saturation temperature, 9 to 20 kW/m2 for heat flux, and 250 to 380 kg/m2s for mass flux. It is shown here that increased heat flux may result in increasing vapor superficial velocity, and then increasing pressure drop. The present experimental results were evaluated with some existing correlations of pressure drop. The best prediction was evaluated by Lockhart-Martinelli (1949) with MARD 25.7%. In order to observe the experimental flow pattern, the present results were also mapped on the Wang flow pattern map.

  9. Achieving uniform layer deposition by atmospheric-pressure plasma-enhanced chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae-Ok [Department of Plasma Engineering, Korea Institute of Machinery & Materials (KIMM), Daejeon 305-343 (Korea, Republic of); Kang, Woo Seok, E-mail: kang@kimm.re.kr [Department of Plasma Engineering, Korea Institute of Machinery & Materials (KIMM), Daejeon 305-343 (Korea, Republic of); Department of Environment & Energy Mechanical Engineering, University of Science & Technology (UST), Daejeon 305-350 (Korea, Republic of); Hur, Min; Lee, Jin Young [Department of Plasma Engineering, Korea Institute of Machinery & Materials (KIMM), Daejeon 305-343 (Korea, Republic of); Song, Young-Hoon [Department of Plasma Engineering, Korea Institute of Machinery & Materials (KIMM), Daejeon 305-343 (Korea, Republic of); Department of Environment & Energy Mechanical Engineering, University of Science & Technology (UST), Daejeon 305-350 (Korea, Republic of)

    2015-12-31

    This work investigates the use of plasma-enhanced chemical vapor deposition under atmospheric pressure for achieving uniform layer formation. Electrical and optical measurements demonstrated that the counterbalance between oxygen and precursors maintained the homogeneous discharge mode, while creating intermediate species for layer deposition. Several steps of the deposition process of the layers, which were processed on a stationary stage, were affected by flow stream and precursor depletion. This study showed that by changing the flow streamlines using substrate stage motion uniform layer deposition under atmospheric pressure can be achieved. - Highlights: • Zirconium oxide was deposited by atmospheric-pressure plasma-enhanced chemical vapor deposition. • Homogeneous plasma was maintained by counterbalancing between discharge gas and precursors. • Several deposition steps were observed affected by the gas flow stream and precursor depletion. • Thin film layer was uniformly grown when the substrate underwent a sweeping motion.

  10. Adiabatic pressure dependence of the 2.7 and 1.9 micron water vapor bands

    Science.gov (United States)

    Mathai, C. V.; Walls, W. L.; Broersma, S.

    1977-01-01

    An acoustic excitation technique is used to determine the adiabatic pressure derivative of the spectral absorptance of the 2.7 and 1.9 micron water vapor bands, and the 3.5 micron HCl band. The dependence of this derivative on thermodynamic parameters such as temperature, concentration, and pressure is evaluated. A cross-flow water vapor system is used to measure spectral absorptance. Taking F as the ratio of nonrigid to rotor line strengths, it is found that an F factor correction is needed for the 2.7 micron band. The F factor for the 1.9 micron band is also determined. In the wings of each band a wavelength can be found where the concentration dependence is predominant. Farther out in the wings a local maximum occurs for the temperature derivative. It is suggested that the pressure derivative is significant in the core of the band.

  11. Vapor pressures of oxide reactor fuels above 3000 K: Review and perspective

    International Nuclear Information System (INIS)

    Breitung, W.

    1982-03-01

    Vapor pressures of liquid oxide reactor fuels are among the most important material data required for theoretical analyses of Hypothetical Core Disruptive Accidents in Fast Breeder Reactors. This report is an attempt to completely summarize and critically review the numerous theoretical and experimental results published for the pressure-temperature and pressure-energy relation of unirradiated UO 2 and (U,Pu)O 2 . First - to define the research goal - the precision in the saturation vapor pressure is quantified which is required for the purpose of HCDA calculations. Then the various theoretical and experimental methods used for the determination of p-T and p-U data are reviewed with respect to their principles, results and uncertainties. The achievements of the individual methods are discussed in the light of the research goal and - in view of the widely scattered data - recommendations are made concerning the p-T and p-U relation of UO 2 . Finally, the most important future research areas are identified, including some specific research proposals which aim at reducing the still large uncertainties in fuel vapor pressures down to the desired level. (orig.) [de

  12. Development of a quasi-adiabatic calorimeter for the determination of the water vapor pressure curve.

    Science.gov (United States)

    Mokdad, S; Georgin, E; Hermier, Y; Sparasci, F; Himbert, M

    2012-07-01

    Progress in the knowledge of the water saturation curve is required to improve the accuracy of the calibrations in humidity. In order to achieve this objective, the LNE-CETIAT and the LNE-CNAM have jointly built a facility dedicated to the measurement of the saturation vapor pressure and temperature of pure water. The principle is based on a static measurement of the pressure and the temperature of pure water in a closed, temperature-controlled thermostat, conceived like a quasi-adiabatic calorimeter. A copper cell containing pure water is placed inside a temperature-controlled copper shield, which is mounted in a vacuum-tight stainless steel vessel immersed in a thermostated bath. The temperature of the cell is measured with capsule-type standard platinum resistance thermometers, calibrated with uncertainties below the millikelvin. The vapor pressure is measured by calibrated pressure sensors connected to the cell through a pressure tube whose temperature is monitored at several points. The pressure gauges are installed in a thermostatic apparatus ensuring high stability of the pressure measurement and avoiding any condensation in the tubes. Thanks to the employment of several technical solutions, the thermal contribution to the overall uncertainty budget is reduced, and the remaining major part is mainly due to pressure measurements. This paper presents a full description of this facility and the preliminary results obtained for its characterization.

  13. Substrate-induced phase of a [1]benzothieno[3,2-b]benzothiophene derivative and phase evolution by aging and solvent vapor annealing.

    Science.gov (United States)

    Jones, Andrew O F; Geerts, Yves H; Karpinska, Jolanta; Kennedy, Alan R; Resel, Roland; Röthel, Christian; Ruzié, Christian; Werzer, Oliver; Sferrazza, Michele

    2015-01-28

    Substrate-induced phases (SIPs) are polymorphic phases that are found in thin films of a material and are different from the single crystal or "bulk" structure of a material. In this work, we investigate the presence of a SIP in the family of [1]benzothieno[3,2-b]benzothiophene (BTBT) organic semiconductors and the effect of aging and solvent vapor annealing on the film structure. Through extensive X-ray structural investigations of spin coated films, we find a SIP with a significantly different structure to that found in single crystals of the same material forms; the SIP has a herringbone motif while single crystals display layered π-π stacking. Over time, the structure of the film is found to slowly convert to the single crystal structure. Solvent vapor annealing initiates the same structural evolution process but at a greatly increased rate, and near complete conversion can be achieved in a short period of time. As properties such as charge transport capability are determined by the molecular structure, this work highlights the importance of understanding and controlling the structure of organic semiconductor films and presents a simple method to control the film structure by solvent vapor annealing.

  14. Controlled Crystal Grain Growth in Mixed Cation-Halide Perovskite by Evaporated Solvent Vapor Recycling Method for High Efficiency Solar Cells.

    Science.gov (United States)

    Numata, Youhei; Kogo, Atsushi; Udagawa, Yosuke; Kunugita, Hideyuki; Ema, Kazuhiro; Sanehira, Yoshitaka; Miyasaka, Tsutomu

    2017-06-07

    We developed a new and simple solvent vapor-assisted thermal annealing (VA) procedure which can reduce grain boundaries in a perovskite film for fabricating highly efficient perovskite solar cells (PSCs). By recycling of solvent molecules evaporated from an as-prepared perovskite film as a VA vapor source, named the pot-roast VA (PR-VA) method, finely controlled and reproducible device fabrication was achieved for formamidinium (FA) and methylammonium (MA) mixed cation-halide perovskite (FAPbI 3 ) 0.85 (MAPbBr 3 ) 0.15 . The mixed perovskite was crystallized on a low-temperature prepared brookite TiO 2 mesoporous scaffold. When exposed to very dilute solvent vapor, small grains in the perovskite film gradually unified into large grains, resulting in grain boundaries which were highly reduced and improvement of photovoltaic performance in PSC. PR-VA-treated large grain perovskite absorbers exhibited stable photocurrent-voltage performance with high fill factor and suppressed hysteresis, achieving the best conversion efficiency of 18.5% for a 5 × 5 mm 2 device and 15.2% for a 1.0 × 1.0 cm 2 device.

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

    Energy Technology Data Exchange (ETDEWEB)

    Munson, Darrell Eugene

    2010-05-01

    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.

  16. The local phase transitions of the solvent in the neighborhood of a solvophobic polymer at high pressures

    Energy Technology Data Exchange (ETDEWEB)

    Budkov, Yu. A., E-mail: urabudkov@rambler.ru [G.A. Krestov Institute of Solution Chemistry of the Russian Academy of Sciences, Ivanovo (Russian Federation); National Research University Higher School of Economics, Moscow (Russian Federation); Department of Chemistry, Lomonosov Moscow State University, Moscow (Russian Federation); Vyalov, I. I. [Istituto Italiano di Tecnologia, via Morego 30, Genova 16163 (Italy); Kolesnikov, A. L. [Ivanovo State University, Ivanovo (Russian Federation); Institut für Nichtklassische Chemie e.V., Universitat Leipzig, Leipzig (Germany); Georgi, N., E-mail: bancocker@mail.ru [Max Planck Institute for Mathematics in the Sciences, Leipzig (Germany); Chuev, G. N. [Max Planck Institute for the Physics of Complex Systems, Dresden (Germany); Institute of Theoretical and Experimental Biophysics, Russian Academy of Science, Pushchino, Moscow Region (Russian Federation); Kiselev, M. G. [G.A. Krestov Institute of Solution Chemistry of the Russian Academy of Sciences, Ivanovo (Russian Federation); Department of Chemistry, Lomonosov Moscow State University, Moscow (Russian Federation)

    2014-11-28

    We investigate local phase transitions of the solvent in the neighborhood of a solvophobic polymer chain which is induced by a change of the polymer-solvent repulsion and the solvent pressure in the bulk solution. We describe the polymer in solution by the Edwards model, where the conditional partition function of the polymer chain at a fixed radius of gyration is described by a mean-field theory. The contributions of the polymer-solvent and the solvent-solvent interactions to the total free energy are described within the mean-field approximation. We obtain the total free energy of the solution as a function of the radius of gyration and the average solvent number density within the gyration volume. The resulting system of coupled equations is solved varying the polymer-solvent repulsion strength at high solvent pressure in the bulk. We show that the coil-globule (globule-coil) transition occurs accompanied by a local solvent evaporation (condensation) within the gyration volume.

  17. Vapor pressure data for fatty acids obtained using an adaptation of the DSC technique

    Energy Technology Data Exchange (ETDEWEB)

    Matricarde Falleiro, Rafael M. [LPT, Departamento de Processos Quimicos (DPQ), Faculdade de Engenharia Quimica, Universidade de Campinas (UNICAMP), 13083-852 Campinas - SP (Brazil); Akisawa Silva, Luciana Y. [Departamento de Ciencias Exatas e da Terra, Universidade Federal de Sao Paulo (UNIFESP), 09972-270 Diadema - SP (Brazil); Meirelles, Antonio J.A. [EXTRAE, Departamento de Engenharia de Alimentos (DEA), Faculdade de Engenharia de Alimentos, Universidade de Campinas (UNICAMP), 13083-862 Campinas - SP (Brazil); Kraehenbuehl, Maria A., E-mail: mak@feq.unicamp.br [LPT, Departamento de Processos Quimicos (DPQ), Faculdade de Engenharia Quimica, Universidade de Campinas (UNICAMP), 13083-852 Campinas - SP (Brazil)

    2012-11-10

    Highlights: Black-Right-Pointing-Pointer Vapor pressure data of fatty acids were measured by Differential Scanning Calorimetry. Black-Right-Pointing-Pointer The DSC technique is especially advantageous for expensive chemicals. Black-Right-Pointing-Pointer High heating rate was used for measuring the vapor pressure data. Black-Right-Pointing-Pointer Antoine constants were obtained for the selected fatty acids. - Abstract: The vapor pressure data for lauric (C{sub 12:0}), myristic (C{sub 14:0}), palmitic (C{sub 16:0}), stearic (C{sub 18:0}) and oleic (C{sub 18:1}) acids were obtained using Differential Scanning Calorimetry (DSC). The adjustments made in the experimental procedure included the use of a small sphere (tungsten carbide) placed over the pinhole of the crucible (diameter of 0.8 mm), making it possible to use a faster heating rate than that of the standard method and reducing the experimental time. The measurements were made in the pressure range from 1333 to 9333 Pa, using small sample quantities of fatty acids (3-5 mg) at a heating rate of 25 K min{sup -1}. The results showed the effectiveness of the technique under study, as evidenced by the low temperature deviations in relation to the data reported in the literature. The Antoine constants were fitted to the experimental data whose values are shown in Table 5.

  18. Vapor pressure data for fatty acids obtained using an adaptation of the DSC technique

    International Nuclear Information System (INIS)

    Matricarde Falleiro, Rafael M.; Akisawa Silva, Luciana Y.; Meirelles, Antonio J.A.; Krähenbühl, Maria A.

    2012-01-01

    Highlights: ► Vapor pressure data of fatty acids were measured by Differential Scanning Calorimetry. ► The DSC technique is especially advantageous for expensive chemicals. ► High heating rate was used for measuring the vapor pressure data. ► Antoine constants were obtained for the selected fatty acids. - Abstract: The vapor pressure data for lauric (C 12:0 ), myristic (C 14:0 ), palmitic (C 16:0 ), stearic (C 18:0 ) and oleic (C 18:1 ) acids were obtained using Differential Scanning Calorimetry (DSC). The adjustments made in the experimental procedure included the use of a small sphere (tungsten carbide) placed over the pinhole of the crucible (diameter of 0.8 mm), making it possible to use a faster heating rate than that of the standard method and reducing the experimental time. The measurements were made in the pressure range from 1333 to 9333 Pa, using small sample quantities of fatty acids (3–5 mg) at a heating rate of 25 K min −1 . The results showed the effectiveness of the technique under study, as evidenced by the low temperature deviations in relation to the data reported in the literature. The Antoine constants were fitted to the experimental data whose values are shown in Table 5.

  19. Dual-pressure vaporization Kalina cycle for cascade reclaiming heat resource for power generation

    International Nuclear Information System (INIS)

    Guo, Zhanwei; Zhang, Zhi; Chen, Yaping; Wu, Jiafeng; Dong, Cong

    2015-01-01

    Graphical abstract: Schematic of the dual-pressure evaporation Kalina cycle. - Highlights: • Dual-pressure vaporization Kalina cycle for high-grade heat resource is investigated. • It is designed with 2nd evaporation branch for cascade utilization of heat resource. • Work and basic concentrations, dew point temperature of evaporation are optimized. • Power recovery efficiency of proposed cycle is 17% higher than that of Kalina cycle. • Dual-p vaporization Kalina cycle fits reclaiming heat resource higher than 350 °C. - Abstract: To further improve the cycle efficiency with the heat transfer curves between higher than 350 °C heat resource and the evaporating working medium of the Kalina cycle and to reduce the exhaust temperature of heat resource, the dual-pressure vaporization Kalina cycle for cascade utilization of high-to-mid grade heat resource is proposed. The optimization was conducted for parameters in this modified Kalina cycle such as concentrations of work solution and basic solution, evaporation dew point temperature. Under the conditions of inlet temperatures of heat resource and cooling water of respectively 400 °C and 25 °C and the constraints of proper heat transfer pinch point temperature differences, the maximum evaporation pressure not exceeds 20 MPa, the vapour quality at the turbine outlet is greater than 0.85 and the exhaust temperature of heat resource is not lower than 90 °C, the optimum parameters are obtained that the work and basic concentrations are 0.45 and 0.272 respectively, the dew point temperature of evaporation is 300 °C, and the corresponding power recovery efficiency of the dual-pressure vaporization Kalina cycle reaches 27%, which is 17% higher than that of the Kalina cycle with optimum parameters.

  20. Growth of aligned ZnO nanowires via modified atmospheric pressure chemical vapor deposition

    International Nuclear Information System (INIS)

    Zhao, Yuping; Li, Chengchen; Chen, Mingming; Yu, Xiao; Chang, Yunwei; Chen, Anqi; Zhu, Hai; Tang, Zikang

    2016-01-01

    In this work, we report the growth of high-quality aligned ZnO nanowires via a facile atmospheric pressure chemical vapor deposition (CVD) method. The CVD reactor chamber used was more complicated than a conventional one due to the quartz boats loaded with sources (ZnO/C) and substrates being inserted into a semi-open quartz tube, and then placed inside the CVD reactor. The semi-open quartz tube played a very important role in growing the ZnO nanowires, and demonstrated that the transportation properties of Zn and O vapor differ from those in the conventional CVD reactor chamber. Aligned ZnO nanowires were successfully obtained, though they were only found at substrates located upstream. The very high crystalline quality of the obtained ZnO nanowires was demonstrated by high-resolution transmission electron microscopy and room temperature photoluminescence investigations. Such ZnO nanowires with high crystalline quality may provide opportunities for the fabrication of ZnO-based nano-devices in future. - Highlights: • High-quality aligned ZnO nanowires were obtained via modified chemical vapor deposition under atmospheric pressure. • The semi-open quartz tube plays very important roles in growing ZnO nanowires. • The transportation properties of Zn and O vapor differ from those in the conventional CVD reactor chamber.

  1. Growth of aligned ZnO nanowires via modified atmospheric pressure chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yuping; Li, Chengchen [Faculty of Science, Jiangsu University, Zhenjiang, Jiangsu, 212013 (China); Chen, Mingming, E-mail: andychain@live.cn [Faculty of Science, Jiangsu University, Zhenjiang, Jiangsu, 212013 (China); Yu, Xiao; Chang, Yunwei [Faculty of Science, Jiangsu University, Zhenjiang, Jiangsu, 212013 (China); Chen, Anqi [State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics & Information Technology, Sun Yat-Sen University, Guangzhou Higher Education Mega Center (University Town), Guangzhou, 510006 (China); Zhu, Hai, E-mail: zhuhai5@mail.sysu.edu.cn [State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics & Information Technology, Sun Yat-Sen University, Guangzhou Higher Education Mega Center (University Town), Guangzhou, 510006 (China); Tang, Zikang, E-mail: zktang@umac.mo [State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics & Information Technology, Sun Yat-Sen University, Guangzhou Higher Education Mega Center (University Town), Guangzhou, 510006 (China); The Institute of Applied Physics and Materials Engineering, University of Macau, Avenida da Universidade, Taipa, Macau (China)

    2016-12-09

    In this work, we report the growth of high-quality aligned ZnO nanowires via a facile atmospheric pressure chemical vapor deposition (CVD) method. The CVD reactor chamber used was more complicated than a conventional one due to the quartz boats loaded with sources (ZnO/C) and substrates being inserted into a semi-open quartz tube, and then placed inside the CVD reactor. The semi-open quartz tube played a very important role in growing the ZnO nanowires, and demonstrated that the transportation properties of Zn and O vapor differ from those in the conventional CVD reactor chamber. Aligned ZnO nanowires were successfully obtained, though they were only found at substrates located upstream. The very high crystalline quality of the obtained ZnO nanowires was demonstrated by high-resolution transmission electron microscopy and room temperature photoluminescence investigations. Such ZnO nanowires with high crystalline quality may provide opportunities for the fabrication of ZnO-based nano-devices in future. - Highlights: • High-quality aligned ZnO nanowires were obtained via modified chemical vapor deposition under atmospheric pressure. • The semi-open quartz tube plays very important roles in growing ZnO nanowires. • The transportation properties of Zn and O vapor differ from those in the conventional CVD reactor chamber.

  2. Impacts of Changes of Indoor Air Pressure and Air Exchange Rate in Vapor Intrusion Scenarios.

    Science.gov (United States)

    Shen, Rui; Suuberg, Eric M

    2016-02-01

    There has, in recent years, been increasing interest in understanding the transport processes of relevance in vapor intrusion of volatile organic compounds (VOCs) into buildings on contaminated sites. These studies have included fate and transport modeling. Most such models have simplified the prediction of indoor air contaminant vapor concentrations by employing a steady state assumption, which often results in difficulties in reconciling these results with field measurements. This paper focuses on two major factors that may be subject to significant transients in vapor intrusion situations, including the indoor air pressure and the air exchange rate in the subject building. A three-dimensional finite element model was employed with consideration of daily and seasonal variations in these factors. From the results, the variations of indoor air pressure and air exchange rate are seen to contribute to significant variations in indoor air contaminant vapor concentrations. Depending upon the assumptions regarding the variations in these parameters, the results are only sometimes consistent with the reports of several orders of magnitude in indoor air concentration variations from field studies. The results point to the need to examine more carefully the interplay of these factors in order to quantitatively understand the variations in potential indoor air exposures.

  3. SIMPOL.1: a simple group contribution method for predicting vapor pressures and enthalpies of vaporization of multifunctional organic compounds

    Directory of Open Access Journals (Sweden)

    J. F. Pankow

    2008-05-01

    Full Text Available The SIMPOL.1 group contribution method is developed for predicting the liquid vapor pressure poL (atm and enthalpy of vaporization Δ Hvap (kJ mol-1 of organic compounds as functions of temperature (T. For each compound i, the method assumes log10poL,i (T=∑kνk,ibk(T where νk,i is the number of groups of type k, and bk (T is the contribution to log10poL,i (T by each group of type k. A zeroeth group is included that uses b0 (T with ν0,i=1 for all i. A total of 30 structural groups are considered: molecular carbon, alkyl hydroxyl, aromatic hydroxyl, alkyl ether, alkyl ring ether, aromatic ether, aldehyde, ketone, carboxylic acid, ester, nitrate, nitro, alkyl amine (primary, secondary, and tertiary, aromatic amine, amide (primary, secondary, and tertiary, peroxide, hydroperoxide, peroxy acid, C=C, carbonylperoxynitrate, nitro-phenol, nitro-ester, aromatic rings, non-aromatic rings, C=C–C=O in a non-aromatic ring, and carbon on the acid-side of an amide. The T dependence in each of the bk (T is assumed to follow b(T=B1/T+B2+B3T+B4ln T. Values of the B coefficients are fit using an initial basis set of 272 compounds for which experimentally based functions po L,i=fi (T are available. The range of vapor pressure considered spans fourteen orders of magnitude. The ability of the initially fitted B coefficients to predict poL values is examined using a test set of 184 compounds and a T range that is as wide as 273

  4. Prediction of high pressure vapor-liquid equilibria with mixing rule using ASOG group contribution method

    Energy Technology Data Exchange (ETDEWEB)

    Tochigi, K.; Kojima, K.; Kurihara, K.

    1985-02-01

    To develop a widely applicable method for predicting high-pressure vapor-liquid equilibria by the equation of state, a mixing rule is proposed in which mixture energy parameter ''..cap alpha..'' of theSoave-RedlichKwong, Peng-Robinson, and Martin cubic equations of state is expressed by using the ASOG group contribution method. The group pair parameters are then determined for 14 group pairs constituted by six groups, i.e. CH/sub 4/, CH/sub 3/, CH/sub 2/, N/sub 2/, H/sub 2/, and CO/sub 2/ groups. By using the group pair parameters determined, high-pressure vapor-liquid equilibria are predicted with good accuracy for binary and ternary systems constituted by n-paraffins, nitrogen, hydrogen, and carbon dioxide in the temperature range of 100 - 450K.

  5. Thermodynamic Modeling and Mechanical Design of a Liquid Nitrogen Vaporization and Pressure Building Device

    Science.gov (United States)

    Leege, Brian J.

    The design of a liquid nitrogen vaporization and pressure building device that has zero product waste while recovering some of its stored energy is of interest for the cost reduction of nitrogen for use in industrial processes. Current devices may waste up to 30% of the gaseous nitrogen product by venting it to atmosphere. Furthermore, no attempt is made to recover the thermal energy available in the coldness of the cryogen. A seven step cycle with changing volumes and ambient heat addition is proposed, eliminating all product waste and providing the means of energy recovery from the nitrogen. This thesis discusses the new thermodynamic cycle and modeling as well as the mechanical design and testing of a prototype device. The prototype was able to achieve liquid nitrogen vaporization and pressurization up to 1000 psi, while full cycle validation is ongoing with promising initial results.

  6. On the critical temperature, normal boiling point, and vapor pressure of ionic liquids.

    Science.gov (United States)

    Rebelo, Luis P N; Canongia Lopes, José N; Esperança, José M S S; Filipe, Eduardo

    2005-04-07

    One-stage, reduced-pressure distillations at moderate temperature of 1-decyl- and 1-dodecyl-3-methylimidazolium bistriflilamide ([Ntf(2)](-)) ionic liquids (ILs) have been performed. These liquid-vapor equilibria can be understood in light of predictions for normal boiling points of ILs. The predictions are based on experimental surface tension and density data, which are used to estimate the critical points of several ILs and their corresponding normal boiling temperatures. In contrast to the situation found for relatively unstable ILs at high-temperature such as those containing [BF(4)](-) or [PF(6)](-) anions, [Ntf(2)](-)-based ILs constitute a promising class in which reliable, accurate vapor pressure measurements can in principle be performed. This property is paramount for assisting in the development and testing of accurate molecular models.

  7. Normal coordinate treatment of liquid water and calculation of vapor pressure isotope effects

    International Nuclear Information System (INIS)

    Gellai, B.; Van Hook, W.A.

    1983-01-01

    A vibrational analysis of liquid water is reported, assuming a completely hydrogen-bonded network with continuously varying strengths of the hydrogen bonds. Frequency distribution calculations are made for intramolecular stretching and bending modes and for the intramolecular frequency region. The calculated distributions are compared with the experimental spectroscopic ones. As another test, vapor pressure isotope effects are calculated from the theoretical distributions for some isotopic water molecules. Results are compared with those of other authors obtained from a mixture model. (author)

  8. Characterization of the TIP4P-Ew water model: vapor pressure and boiling point.

    Science.gov (United States)

    Horn, Hans W; Swope, William C; Pitera, Jed W

    2005-11-15

    The liquid-vapor-phase equilibrium properties of the previously developed TIP4P-Ew water model have been studied using thermodynamic integration free-energy simulation techniques in the temperature range of 274-400 K. We stress that free-energy results from simulations need to be corrected in order to be compared to the experiment. This is due to the fact that the thermodynamic end states accessible through simulations correspond to fictitious substances (classical rigid liquids and classical rigid ideal gases) while experiments operate on real substances (liquids and real gases, with quantum effects). After applying analytical corrections the vapor pressure curve obtained from simulated free-energy changes is in excellent agreement with the experimental vapor pressure curve. The boiling point of TIP4P-Ew water under ambient pressure is found to be at 370.3+/-1.9 K, about 7 K higher than the boiling point of TIP4P water (363.7+/-5.1 K; from simulations that employ finite range treatment of electrostatic and Lennard-Jones interactions). This is in contrast to the approximately +15 K by which the temperature of the density maximum and the melting temperature of TIP4P-Ew are shifted relative to TIP4P, indicating that the temperature range over which the liquid phase of TIP4P-Ew is stable is narrower than that of TIP4P and resembles more that of real water. The quality of the vapor pressure results highlights the success of TIP4P-Ew in describing the energetic and entropic aspects of intermolecular interactions in liquid water.

  9. Volatile times for the very first ionic liquid: understanding the vapor pressures and enthalpies of vaporization of ethylammonium nitrate.

    Science.gov (United States)

    Emel'yanenko, Vladimir N; Boeck, Gisela; Verevkin, Sergey P; Ludwig, Ralf

    2014-09-08

    A hundred years ago, Paul Walden studied ethyl ammonium nitrate (EAN), which became the first widely known ionic liquid. Although EAN has been investigated extensively, some important issues still have not been addressed; they are now tackled in this communication. By combining experimental thermogravimetric analysis with time of flight mass spectrometry (TGA-ToF-MS) and transpiration method with theoretical methods, we clarify the volatilisation of EAN from ambient to elevated temperatures. It was observed that up to 419 K, EAN evaporates as contact-ion pairs leading to very low vapour pressures of a few Pascal. Starting from 419 K, the decomposition to nitric acid and ethylamine becomes more thermodynamically favourable than proton transfer. This finding was supported by DFT calculations, which provide the free energies of all possible gas-phase species, and show that neutral molecules dominate over ion pairs above 500 K, an observation that is in nearly prefect agreement with the experimental boiling point of 513 K. This result is crucial for the ongoing practical applications of protic ionic liquids such as electrolytes for batteries and fuel cells because, in contrast to high-boiling conventional solvents, EAN exhibits no significant vapour pressure below 419 K and this property fulfils the requirements for the thermal behaviour of safe electrolytes. Overall, EAN shows the same barely measurable vapour pressures as typical aprotic ionic liquids at temperatures only 70 K lower. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Vapor pressures and sublimation enthalpies of seven heteroatomic aromatic hydrocarbons measured using the Knudsen effusion technique

    International Nuclear Information System (INIS)

    Goldfarb, Jillian L.; Suuberg, Eric M.

    2010-01-01

    The vapor pressures of seven heteroatom-containing cyclic aromatic hydrocarbons, ranging in molecular weight from (168.19 to 208.21) g . mol -1 were measured over the temperature range of (301 to 486) K using the isothermal Knudsen effusion technique. The compounds measured include: anthraquinone, 9-fluorenone, 9-fluorenone oxime, phenoxazine, phenoxathiin, and 9H-pyrido[3,4-b]indole. These solid-state sublimation measurements provided values that are compared to vapor pressures of parent aromatic compounds (anthracene and fluorene) and to others with substituent groups in order to examine the effects of alcohol, ketone, pyridine, and pyrrole functionality on this property. The enthalpies and entropies of sublimation for each compound were determined from the Clausius-Clapeyron equation. Though there is no consistent trend in terms of the effects of substitutions on changes in the enthalpy or entropy of sublimation, we note that the prevalence of enthalpic or entropic driving forces on vapor pressure depend on molecule-specific factors and not merely molecular weight of the substituents.

  11. Assessment of Fluctuation Patterns Similarity in Temperature and Vapor Pressure Using Discrete Wavelet Transform

    Directory of Open Access Journals (Sweden)

    A. Araghi

    2014-12-01

    Full Text Available Period and trend are two main effective and important factors in hydro-climatological time series and because of this importance, different methods have been introduced and applied to study of them, until now. Most of these methods are statistical basis and they are classified in the non-parametric tests. Wavelet transform is a mathematical based powerful method which has been widely used in signal processing and time series analysis in recent years. In this research, trend and main periodic patterns similarity in temperature and vapor pressure has been studied in Babolsar, Tehran and Shahroud synoptic stations during 55 years period (from 1956 to 2010, using wavelet method and the sequential Mann-Kendall trend test. The results show that long term fluctuation patterns in temperature and vapor pressure have more correlations in the arid and semi-arid climates, as well as short term oscillation patterns in temperature and vapor pressure in the humid climates, and these dominant periods increase with the aridity of region.

  12. Vapor pressures and sublimation enthalpies of seven heteroatomic aromatic hydrocarbons measured using the Knudsen effusion technique

    Energy Technology Data Exchange (ETDEWEB)

    Goldfarb, Jillian L., E-mail: JillianLGoldfarb@gmail.co [Division of Engineering, Brown University, Providence, RI 02912 (United States); Suuberg, Eric M., E-mail: Eric_Suuberg@brown.ed [Division of Engineering, Brown University, Providence, RI 02912 (United States)

    2010-06-15

    The vapor pressures of seven heteroatom-containing cyclic aromatic hydrocarbons, ranging in molecular weight from (168.19 to 208.21) g . mol{sup -1} were measured over the temperature range of (301 to 486) K using the isothermal Knudsen effusion technique. The compounds measured include: anthraquinone, 9-fluorenone, 9-fluorenone oxime, phenoxazine, phenoxathiin, and 9H-pyrido[3,4-b]indole. These solid-state sublimation measurements provided values that are compared to vapor pressures of parent aromatic compounds (anthracene and fluorene) and to others with substituent groups in order to examine the effects of alcohol, ketone, pyridine, and pyrrole functionality on this property. The enthalpies and entropies of sublimation for each compound were determined from the Clausius-Clapeyron equation. Though there is no consistent trend in terms of the effects of substitutions on changes in the enthalpy or entropy of sublimation, we note that the prevalence of enthalpic or entropic driving forces on vapor pressure depend on molecule-specific factors and not merely molecular weight of the substituents.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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 °C). 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.

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

    International Nuclear Information System (INIS)

    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 ℃). 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.

  16. Characteristics of the Na/beta-alumina/Na cell as a sodium vapor pressure sensor

    International Nuclear Information System (INIS)

    Takikawa, O.; Imai, A.; Harata, M.

    1982-01-01

    The EMF and voltage-current characteristics for a galvanic cell with the configuration Na vapor (P 1 )/sodium beta-alumina/Na vapor (P 2 ) were studied. It was verified that the EMF followed the Nernst relation over a wide pressure range. For example, when P 1 = 2 x 10 -2 mm Hg and beta-alumina temperature = 340 0 C, the measured EMF agreed with the calculated value in P 2 range from 10 -5 to 10 -2 mm Hg. At lower pressure range, the measured EMF showed a negative deviation. Coexisting argon gas did not influence the cell EMF characteristic. In an atmosphere containing oxygen, the measured EMF was very high at first. Then it decreased and finally approached a value which agreed with the Nernst equation after several hours. At low beta-alumina temperatures, current saturation was observed in the voltage versus current relation with the anode on the P 2 side. Although the sodium pressure could be determined from saturating current measurement, the measurable pressure range was narrower than that for EMF measurement. At high beta-alumina temperature, current saturation was not clear. Values of 6 x 10 -6 (Ω cm) -1 for the electron conductivity and 6 x 10 -10 (Ω cm) -1 for the hole conductivity at 340 0 C were obtained for beta-alumina from the voltage-current characteristics at low sodium pressure. (Auth.)

  17. In-pile vapor pressure measurements on UO2 and (U,Pu)O2

    International Nuclear Information System (INIS)

    Breitung, W.; Reil, K.O.

    1985-08-01

    The Effective-Equation-of-State (EEOS) experiments investigated the saturation vapor pressures of ultra pure UO 2 , reactor grade UO 2 , and reactor grade (Usub(.77)Pusub(.23))O2 using newly developed in-pile heating techniques. For enthalpies between 2150 and 3700 kJ/kg (about 4700 to 8500 K) vapor pressures from 1.3 to 54 MPa were measured. The p-h curves of all three fuel types were identical within the experimental uncertainties. An assessment of all published p-h measurements showed that the p-h saturation curve of UO 2 appears now well established by the EEOS and the CEA in-pile data. Using an estimate for the heat capacity of liquid UO 2 , the in-pile results were also compared to earlier p-T measurements. The assessments lead to proposal of two equations. Equation I, which includes a factor-of-2 uncertainty band, covers all p-T equilibrium evaporation measurements. Equation I yields 3817 K for the normal boiling point, 415.4 kJ/mol for the corresponding heat of vaporization, and 1.90 MPa for the vapor pressure at 5000 K. Equations I and II, which represent a parametric form of the p-h curve (T=parameter), also give a good description of the EEOS and CEA in-pile data. Thus the proposed equations allow a consistent representation of both p-T and p-h measurements, they are sufficiently precise for CDA analyses and cover the whole range of interest (3120-8500 K, 1400-3700 kJ/kg). (orig./HP) [de

  18. Robust design for shape parameters of high pressure thermal vapor compressor by numerical analysis

    International Nuclear Information System (INIS)

    Park, Il Seouk

    2008-01-01

    A high motive pressure Thermal Vapor Compressor(TVC) for a commercial Multi-Effect Desalination(MED) plant is designed to have a high entraining performance and its robustness is also considered in the respect of operating stability at the abrupt change of the operating pressures like the motive and suction steam pressure which can be easily fluctuated by the external disturbance. The TVC having a good entraining performance of more than entrainment ratio 6.0 is designed through the iterative CFD analysis for the various primary nozzle diameter, mixing tube diameter and mixing tube length. And then for a couple of TVC having a similar entrainment ratio, the changes of the entrainment ratio are checked along the motive and suction pressure change. The system stability is diagnosed through the analyzing the changing pattern of the entrainment ratio

  19. Effects of ambient temperature and water vapor on chamber pressure and oxygen level during low atmospheric pressure stunning of poultry.

    Science.gov (United States)

    Holloway, Paul H; Pritchard, David G

    2017-08-01

    The characteristics of the vacuum used in a low atmospheric pressure stunning system to stun (render unconscious) poultry prior to slaughter are described. A vacuum chamber is pumped by a wet screw compressor. The vacuum pressure is reduced from ambient atmospheric pressure to an absolute vacuum pressure of ∼250 Torr (∼33 kPa) in ∼67 sec with the vacuum gate valve fully open. At ∼250 Torr, the sliding gate valve is partially closed to reduce effective pumping speed, resulting in a slower rate of decreasing pressure. Ambient temperature affects air density and water vapor pressure and thereby oxygen levels and the time at the minimum total pressure of ∼160 Torr (∼21 kPa) is varied from ∼120 to ∼220 sec to ensure an effective stun within the 280 seconds of each cycle. The reduction in total pressure results in a gradual reduction of oxygen partial pressure that was measured by a solid-state electrochemical oxygen sensor. The reduced oxygen pressure leads to hypoxia, which is recognized as a humane method of stunning poultry. The system maintains an oxygen concentration of air always reduces the oxygen concentrations to a value lower than in dry air. The partial pressure of water and oxygen were found to depend on the pump down parameters due to the formation of fog in the chamber and desorption of water from the birds and the walls of the vacuum chamber. © The Author 2017. Published by Oxford University Press on behalf of Poultry Science Association.

  20. The Effect of Pressure and Solvent on the Supercritical Fluid Chromatography Separation of Tocol Analogs in Palm Oil

    Directory of Open Access Journals (Sweden)

    Mei Han Ng

    2017-08-01

    Full Text Available There are six tocol analogs present in palm oil, namely α-tocopherol (α-T, α-tocomonoenol (α-T1, α-tocotrienol (α-T3, γ-tocotrienol (γ-T3, β-tocotrioenol (β-T3 and δ-tocotrienol (δ-T3. These analogs were difficult to separate chromatographically due to their similar structures, physical and chemical properties. This paper reports on the effect of pressure and injection solvent on the separation of the tocol analogs in palm oil. Supercritical CO2 modified with ethanol was used as the mobile phase. Both total elution time and resolution of the tocol analogs decreased with increased pressure. Ethanol as an injection solvent resulted in peak broadening of the analogs within the entire pressure range studied. Solvents with an eluent strength of 3.4 or less were more suitable for use as injecting solvents.

  1. GOZCARDS Merged Data for Water Vapor Monthly Zonal Means on a Geodetic Latitude and Pressure Grid V1.01

    Data.gov (United States)

    National Aeronautics and Space Administration — The GOZCARDS Merged Data for Water Vapor Monthly Zonal Averages on a Geodetic Latitude and Pressure Grid product (GozMmlpH2O) contains zonal means and related...

  2. A thermodynamic study of glucose and related oligomers in aqueous solution: Vapor pressures and enthalpies of mixing

    DEFF Research Database (Denmark)

    Cooke, S.A.; Jonsdottir, Svava Osk; Westh, Peter

    2002-01-01

    Vapor pressures above aqueous solutions of glucose and maltose at both 298.06 K and 317.99 K and vapor pressures above aqueous solutions of cellobiose, maltotriose, maltotetraose, and maltopentaose at 317.99 K have been measured. The excess enthalpies have been recorded for all of the above-menti...... in aqueous solution. This so-called transference principle is found to be of interest in furthering the discussion concerning the applicability of lattice-based models for solution theory....

  3. Pressure intelligent control strategy of Waste heat recovery system of converter vapors

    Science.gov (United States)

    Feng, Xugang; Wu, Zhiwei; Zhang, Jiayan; Qian, Hong

    2013-01-01

    The converter gas evaporative cooling system is mainly used for absorbing heat in the high temperature exhaust gas which produced by the oxygen blowing reaction. Vaporization cooling steam pressure control system of converter is a nonlinear, time-varying, lagging behind, close coupling of multivariable control object. This article based on the analysis of converter operation characteristics of evaporation cooling system, of vaporization in a production run of pipe pressure variation and disturbance factors.For the dynamic characteristics of the controlled objects,we have improved the conventional PID control scheme.In Oxygen blowing process, we make intelligent control by using fuzzy-PID cascade control method and adjusting the Lance,that it can realize the optimization of the boiler steam pressure control.By design simulation, results show that the design has a good control not only ensures drum steam pressure in the context of security, enabling efficient conversion of waste heat.And the converter of 1800 flue gas through pipes and cool and dust removal also can be cooled to about 800. Therefore the converter haze evaporative cooling system has achieved to the converter haze temperature decrease effect and enhanced to the coal gas returns-ratio.

  4. Kinetics and dynamics of nanosecond streamer discharge in atmospheric-pressure gas bubble suspended in distilled water under saturated vapor pressure conditions

    KAUST Repository

    Sharma, Ashish; Levko, Dmitry; Raja, Laxminarayan L; Cha, Min

    2016-01-01

    We perform computational studies of nanosecond streamer discharges generated in helium bubbles immersed in distilled water under atmospheric pressure conditions. The model takes into account the presence of water vapor in the gas bubble

  5. Highly ionized physical vapor deposition plasma source working at very low pressure

    Science.gov (United States)

    Stranak, V.; Herrendorf, A.-P.; Drache, S.; Cada, M.; Hubicka, Z.; Tichy, M.; Hippler, R.

    2012-04-01

    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+ and Ti++ peaks are observed in the mass scan spectra). This corresponds well with high plasma density ne ˜ 1018 m-3, measured during the HiPIMS pulse.

  6. Highly ionized physical vapor deposition plasma source working at very low pressure

    International Nuclear Information System (INIS)

    Stranak, V.; Herrendorf, A.-P.; Drache, S.; Hippler, R.; Cada, M.; Hubicka, Z.; Tichy, M.

    2012-01-01

    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 + and Ti ++ peaks are observed in the mass scan spectra). This corresponds well with high plasma density n e ∼ 10 18 m -3 , measured during the HiPIMS pulse.

  7. Two dimensional radial gas flows in atmospheric pressure plasma-enhanced chemical vapor deposition

    Science.gov (United States)

    Kim, Gwihyun; Park, Seran; Shin, Hyunsu; Song, Seungho; Oh, Hoon-Jung; Ko, Dae Hong; Choi, Jung-Il; Baik, Seung Jae

    2017-12-01

    Atmospheric pressure (AP) operation of plasma-enhanced chemical vapor deposition (PECVD) is one of promising concepts for high quality and low cost processing. Atmospheric plasma discharge requires narrow gap configuration, which causes an inherent feature of AP PECVD. Two dimensional radial gas flows in AP PECVD induces radial variation of mass-transport and that of substrate temperature. The opposite trend of these variations would be the key consideration in the development of uniform deposition process. Another inherent feature of AP PECVD is confined plasma discharge, from which volume power density concept is derived as a key parameter for the control of deposition rate. We investigated deposition rate as a function of volume power density, gas flux, source gas partial pressure, hydrogen partial pressure, plasma source frequency, and substrate temperature; and derived a design guideline of deposition tool and process development in terms of deposition rate and uniformity.

  8. High temperature vapor pressures of stainless steel type 1.4970 and of some other pure metals from laser evaporation

    International Nuclear Information System (INIS)

    Bober, M.; Singer, J.

    1984-10-01

    For the safety analysis of nuclear reactors vapor pressure data of stainless steel are required up to temperatures exceeding 4000 K. In analogy to the classic boiling point method a new technique was developed to measure the high-temperature vapor pressures of stainless steel and other metals from laser vaporization. A fast pyrometer, an ion current probe and an image converter camera are used to detect incipient boiling from the time-temperature curve. The saturated-vapor pressure curves of stainless steel (Type 1.4970), being a cladding material of the SNR 300 breeder reactor, and of molybdenum are experimentally determined in the temperature ranges of 2800-3900 K and 4500-5200 K, respectively. The normal boiling points of iron, nickel, titanium, vanadium and zirconium are verified. Besides, spectral emissivity values of the liquid metals are measured at the pyrometer wavelengths of 752 nm and/or 940 nm. (orig.) [de

  9. A systematic study of atmospheric pressure chemical vapor deposition growth of large-area monolayer graphene.

    Science.gov (United States)

    Liu, Lixin; Zhou, Hailong; Cheng, Rui; Chen, Yu; Lin, Yung-Chen; Qu, Yongquan; Bai, Jingwei; Ivanov, Ivan A; Liu, Gang; Huang, Yu; Duan, Xiangfeng

    2012-01-28

    Graphene has attracted considerable interest as a potential material for future electronics. Although mechanical peel is known to produce high quality graphene flakes, practical applications require continuous graphene layers over a large area. The catalyst-assisted chemical vapor deposition (CVD) is a promising synthetic method to deliver wafer-sized graphene. Here we present a systematic study on the nucleation and growth of crystallized graphene domains in an atmospheric pressure chemical vapor deposition (APCVD) process. Parametric studies show that the mean size of the graphene domains increases with increasing growth temperature and CH 4 partial pressure, while the density of domains decreases with increasing growth temperature and is independent of the CH 4 partial pressure. Our studies show that nucleation of graphene domains on copper substrate is highly dependent on the initial annealing temperature. A two-step synthetic process with higher initial annealing temperature but lower growth temperature is developed to reduce domain density and achieve high quality full-surface coverage of monolayer graphene films. Electrical transport measurements demonstrate that the resulting graphene exhibits a high carrier mobility of up to 3000 cm 2 V -1 s -1 at room temperature.

  10. Influence of the helium-pressure on diode-pumped alkali-vapor laser

    Science.gov (United States)

    Gao, Fei; Chen, Fei; Xie, Ji-jiang; Zhang, Lai-ming; Li, Dian-jun; Yang, Gui-long; Guo, Jing

    2013-05-01

    Diode-pumped alkali-vapor laser (DPAL) is a kind of laser attracted much attention for its merits, such as high quantum efficiency, excellent beam quality, favorable thermal management, and potential scalability to high power and so on. Based on the rate-equation theory of end-pumped DPAL, the performances of DPAL using Cs-vapor collisionally broadened by helium are simulated and studied. With the increase of helium pressure, the numerical results show that: 1) the absorption line-width increases and the stimulated absorption cross-section decreases contrarily; 2) the threshold pumping power decreases to minimum and then rolls over to increase linearly; 3) the absorption efficiency rises to maximum initially due to enough large stimulated absorption cross-section in the far wings of collisionally broadened D2 transition (absorption transition), and then begins to reduce; 4) an optimal value of helium pressure exists to obtain the highest output power, leading to an optimal optical-optical efficiency. Furthermore, to generate the self-oscillation of laser, a critical value of helium pressure occurs when small-signal gain equals to the threshold gain.

  11. High-pressure (vapor + liquid) equilibria in the (nitrogen + n-heptane) system

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Sanchez, Fernando [Laboratorio de Termodinamica, Programa de Ingenieria Molecular, Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152, 07730 Mexico, D.F. (Mexico)]. E-mail: fgarcias@imp.mx; Eliosa-Jimenez, Gaudencio [Laboratorio de Termodinamica, Programa de Ingenieria Molecular, Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152, 07730 Mexico, D.F. (Mexico); Silva-Oliver, Guadalupe [Laboratorio de Termodinamica, Programa de Ingenieria Molecular, Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152, 07730 Mexico, D.F. (Mexico); Godinez-Silva, Armando [Laboratorio de Termodinamica, Programa de Ingenieria Molecular, Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152, 07730 Mexico, D.F. (Mexico)

    2007-06-15

    In this work, new (vapor + liquid) equilibrium data for the (N{sub 2} + n-heptane) system were experimentally measured over a wide temperature range from (313.6 to 523.7) K and pressures up to 50 MPa. A static-analytic apparatus with visual sapphire windows and pneumatic capillary samplers was used in the experimental measurements. Equilibrium phase compositions and (vapor + liquid) equilibrium ratios are reported. The new results were compared with those reported by other authors. The comparison showed that the pressure-composition data reported in this work are less scattered than those determined by others. Hence, the results demonstrate the reliability of the experimental apparatus at high temperatures and pressures. The experimental data were represented with the PR and PC-SAFT equations of state by using one-fluid mixing rules and a single temperature independent interaction parameter. Results of the representation showed that the PC-SAFT equation was superior to the PR equation in correlating the experimental data of the (N{sub 2} + n-heptane) system.

  12. High-pressure (vapor + liquid) equilibria in the (nitrogen + n-heptane) system

    International Nuclear Information System (INIS)

    Garcia-Sanchez, Fernando; Eliosa-Jimenez, Gaudencio; Silva-Oliver, Guadalupe; Godinez-Silva, Armando

    2007-01-01

    In this work, new (vapor + liquid) equilibrium data for the (N 2 + n-heptane) system were experimentally measured over a wide temperature range from (313.6 to 523.7) K and pressures up to 50 MPa. A static-analytic apparatus with visual sapphire windows and pneumatic capillary samplers was used in the experimental measurements. Equilibrium phase compositions and (vapor + liquid) equilibrium ratios are reported. The new results were compared with those reported by other authors. The comparison showed that the pressure-composition data reported in this work are less scattered than those determined by others. Hence, the results demonstrate the reliability of the experimental apparatus at high temperatures and pressures. The experimental data were represented with the PR and PC-SAFT equations of state by using one-fluid mixing rules and a single temperature independent interaction parameter. Results of the representation showed that the PC-SAFT equation was superior to the PR equation in correlating the experimental data of the (N 2 + n-heptane) system

  13. Correlation of the vapor pressure isotope effect with molecular force fields in the liquid state

    International Nuclear Information System (INIS)

    Pollin, J.S.; Ishida, T.

    1976-07-01

    The present work is concerned with the development and application of a new model for condensed phase interactions with which the vapor pressure isotope effect (vpie) may be related to molecular forces and structure. The model considers the condensed phase as being represented by a cluster of regularly arranged molecules consisting of a central molecule and a variable number of molecules in the first coordination shell. The methods of normal coordinate analysis are used to determine the modes of vibration of the condensed phase cluster from which, in turn, the isotopic reduced partition function can be calculated. Using the medium cluster model, the observed vpie for a series of methane isotopes has been successfully reproduced with better agreement with experiment than has been possible using the simple cell model. We conclude, however, that insofar as the medium cluster model provides a reasonable picture of the liquid state, the vpie is not sufficiently sensitive to molecular orientation to permit an experimental determination of intermolecular configuration in the condensed phase through measurement of isotopic pressure ratios. The virtual independence of vapor pressure isotope effects on molecular orientation at large cluster sizes is a demonstration of the general acceptability of the cell model assumptions for vpie calculations

  14. Optimization of the solvent-based dissolution method to sample volatile organic compound vapors for compound-specific isotope analysis.

    Science.gov (United States)

    Bouchard, Daniel; Wanner, Philipp; Luo, Hong; McLoughlin, Patrick W; Henderson, James K; Pirkle, Robert J; Hunkeler, Daniel

    2017-10-20

    The methodology of the solvent-based dissolution method used to sample gas phase volatile organic compounds (VOC) for compound-specific isotope analysis (CSIA) was optimized to lower the method detection limits for TCE and benzene. The sampling methodology previously evaluated by [1] consists in pulling the air through a solvent to dissolve and accumulate the gaseous VOC. After the sampling process, the solvent can then be treated similarly as groundwater samples to perform routine CSIA by diluting an aliquot of the solvent into water to reach the required concentration of the targeted contaminant. Among solvents tested, tetraethylene glycol dimethyl ether (TGDE) showed the best aptitude for the method. TGDE has a great affinity with TCE and benzene, hence efficiently dissolving the compounds during their transition through the solvent. The method detection limit for TCE (5±1μg/m 3 ) and benzene (1.7±0.5μg/m 3 ) is lower when using TGDE compared to methanol, which was previously used (385μg/m 3 for TCE and 130μg/m 3 for benzene) [2]. The method detection limit refers to the minimal gas phase concentration in ambient air required to load sufficient VOC mass into TGDE to perform δ 13 C analysis. Due to a different analytical procedure, the method detection limit associated with δ 37 Cl analysis was found to be 156±6μg/m 3 for TCE. Furthermore, the experimental results validated the relationship between the gas phase TCE and the progressive accumulation of dissolved TCE in the solvent during the sampling process. Accordingly, based on the air-solvent partitioning coefficient, the sampling methodology (e.g. sampling rate, sampling duration, amount of solvent) and the final TCE concentration in the solvent, the concentration of TCE in the gas phase prevailing during the sampling event can be determined. Moreover, the possibility to analyse for TCE concentration in the solvent after sampling (or other targeted VOCs) allows the field deployment of the sampling

  15. Modeling and control of diffusion and low-pressure chemical vapor deposition furnaces

    Science.gov (United States)

    De Waard, H.; De Koning, W. L.

    1990-03-01

    In this paper a study is made of the heat transfer inside cylindrical resistance diffusion and low-pressure chemical vapor deposition furnaces, aimed at developing an improved temperature controller. A model of the thermal behavior is derived which also covers the important class of furnaces equipped with semitransparent quartz process tubes. The model takes into account the thermal behavior of the thermocouples. It is shown that currently used temperature controllers are highly inefficient for very large scale integration applications. Based on the model an alternative temperature controller of the linear-quadratic-Gaussian type is proposed which features direct wafer temperature control. Some simulation results are given.

  16. Iron exclusion in rice genotypes as affected by different vapor pressure deficit conditions

    Directory of Open Access Journals (Sweden)

    Ram Kumar Shrestha

    2015-08-01

    Full Text Available Root iron (Fe exclusion capacity of four lowland rice genotypes were evaluated in increasing rate of Fe2+ stresses (0, 500, 1000 and 1500 mg/L in growing medium under the conditions of low and high vapor pressure deficit. Rice root excluded significantly higher amount of iron under dry atmospheric condition (655 mg Fe/g root dry matter than moist atmospheric condition (118 mg Fe/g root dry matter. But their iron exclusion capacity reduced when they were gradually exposed to the higher levels of Fe stress. Tolerant genotype such as TOX3107 excluded more iron when they were exposed to dry atmospheric condition.

  17. Evaluation of Vapor Pressure Estimation Methods for Use in Simulating the Dynamic of Atmospheric Organic Aerosols

    Directory of Open Access Journals (Sweden)

    A. J. Komkoua Mbienda

    2013-01-01

    Lee and Kesler (LK, and Ambrose-Walton (AW methods for estimating vapor pressures ( are tested against experimental data for a set of volatile organic compounds (VOC. required to determine gas-particle partitioning of such organic compounds is used as a parameter for simulating the dynamic of atmospheric aerosols. Here, we use the structure-property relationships of VOC to estimate . The accuracy of each of the aforementioned methods is also assessed for each class of compounds (hydrocarbons, monofunctionalized, difunctionalized, and tri- and more functionalized volatile organic species. It is found that the best method for each VOC depends on its functionality.

  18. Saturated vapor pressure over molten mixtures of GaCl3 and alkali metal chlorides

    International Nuclear Information System (INIS)

    Salyulev, A.B.; Smolenskij, V.V.; Moskalenko, N.I.

    2004-01-01

    Volatilities of GaCl 3 and alkali metal chlorides over diluted (up to 3 mol %) solutions of GaCl 3 in LiCl, NaCl, KCl, RbCl, and CsCl were measured at 1100 K by dynamic and indirect static methods. Chemical composition of saturated vapor over the mixed melts was determined. Partial pressures of the components were calculated. Their values depend essentially on specific alkali metal cation and on concentration of GaCl 3 ; their variation permits altering parameters of GaCl 3 distillation from the salt melt in a wide range [ru

  19. Pressurization of a Flightweight, Liquid Hydrogen Tank: Evaporation & Condensation at a Liquid/Vapor Interface

    Science.gov (United States)

    Stewart, Mark E. M.

    2017-01-01

    This paper presents an analysis and simulation of evaporation and condensation at a motionless liquid/vapor interface. A 1-D model equation, emphasizing heat and mass transfer at the interface, is solved in two ways, and incorporated into a subgrid interface model within a CFD simulation. Simulation predictions are compared with experimental data from the CPST Engineering Design Unit tank, a cryogenic fluid management test tank in 1-g. The numerical challenge here is the physics of the liquid/vapor interface; pressurizing the ullage heats it by several degrees, and sets up an interfacial temperature gradient that transfers heat to the liquid phase-the rate limiting step of condensation is heat conducted through the liquid and vapor. This physics occurs in thin thermal layers O(1 mm) on either side of the interface which is resolved by the subgrid interface model. An accommodation coefficient of 1.0 is used in the simulations which is consistent with theory and measurements. This model is predictive of evaporation/condensation rates, that is, there is no parameter tuning.

  20. Morphology and properties of silica/novolac hybrid xerogels synthesized using sol–gel polymerization at solvent vapor-saturated atmosphere

    International Nuclear Information System (INIS)

    Seraji, Mohamad Mehdi; Seifi, Azadeh; Bahramian, Ahmad Reza

    2015-01-01

    Highlights: • Sol–gel polymerization in vapor of solvent saturated atmosphere is developed. • Highly porous novolac–silica hybrid xerogels are successfully synthesized. • Novolac–silica hybrid gel was dried in ambient condition with low shrinkage. • Required time for preparation of gel reduced from 5 days to about 5 h. • By incorporation of silica into the novolac xerogel structure, the pore size decreases. - Abstract: Highly porous novolac–silica hybrid xerogels were successfully synthesized via the novel method of sol–gel polymerization in solvent vapor-saturated atmosphere. This method removes the need for supercritical drying and yields the hybrid xerogels with reduced shrinkage in comparison with conventional sol–gel process. Tetraethoxysilane (TEOS) was used as the precursor of silica-based inorganic phase. The chemical and structural characterization of the prepared hybrid xerogels were performed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) analysis, respectively. Thermal and mechanical properties of the hybrid samples were investigated by differential scanning calorimetry (DSC), and compressive strength analysis. The resultant hybrid xerogels show a nanostructured colloidal hybrid network with high porosity (above 80%) and low density (below 0.25 g cm −3 ). Si mapping images shows the good distribution of silica phase throughout the hybrid structure

  1. Sequential extraction of flavonoids and pectin from yellow passion fruit rind using pressurized solvent or ultrasound.

    Science.gov (United States)

    de Souza, Caroline G; Rodrigues, Tigressa Hs; E Silva, Lorena Ma; Ribeiro, Paulo Rv; de Brito, Edy S

    2018-03-01

    Passion fruit rind (PFR) represents 90% of the total fruit weight and is wasted during juice processing. Passion fruit rind is known to contain flavonoids and pectin. An alternative use for this fruit juice industrial residue is to obtain these compounds. This study aimed to verify the influence of pressurized solvent extraction (PSE) or ultrasound assisted extraction (UAE) of flavonoid and pectin in a sequential process. The PSE using ethanol at 60:40 (v/v) yielded a total polyphenol content of 4.67 g GAE kg -1 PFR, orientin-7-O-glucoside (1.57 g kg -1 PFR) and luteolin-6-C-glucoside (2.44 g kg -1 PFR). Pectin yield was 165 g kg -1 PFR, either in PSE or UAE. Pectin characterization indicates that the pectic structure has basically homogalacturonans and galacturonate followed by a galacturonic acid ester unit, with methylation degree of 70%. With this study it can be concluded that mixtures of alcohols with water favor the extraction of bioactive compounds of passion fruit peel. Both PSE and UAE were effective in sequentially extracting flavonoids and pectin. The preferred solvent is ethanol due to its lower toxicity. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  2. Conformal coating of amorphous silicon and germanium by high pressure chemical vapor deposition for photovoltaic fabrics

    Science.gov (United States)

    Ji, Xiaoyu; Cheng, Hiu Yan; Grede, Alex J.; Molina, Alex; Talreja, Disha; Mohney, Suzanne E.; Giebink, Noel C.; Badding, John V.; Gopalan, Venkatraman

    2018-04-01

    Conformally coating textured, high surface area substrates with high quality semiconductors is challenging. Here, we show that a high pressure chemical vapor deposition process can be employed to conformally coat the individual fibers of several types of flexible fabrics (cotton, carbon, steel) with electronically or optoelectronically active materials. The high pressure (˜30 MPa) significantly increases the deposition rate at low temperatures. As a result, it becomes possible to deposit technologically important hydrogenated amorphous silicon (a-Si:H) from silane by a simple and very practical pyrolysis process without the use of plasma, photochemical, hot-wire, or other forms of activation. By confining gas phase reactions in microscale reactors, we show that the formation of undesired particles is inhibited within the microscale spaces between the individual wires in the fabric structures. Such a conformal coating approach enables the direct fabrication of hydrogenated amorphous silicon-based Schottky junction devices on a stainless steel fabric functioning as a solar fabric.

  3. Vapor-liquid Phase Equilibria for CO2+Tertpentanol Binary System at Elevated Pressures

    Institute of Scientific and Technical Information of China (English)

    WANG Lin; LUO Jian-cheng; YANG Hao; CHEN Kai-xun

    2011-01-01

    Vapor-liquid phase equilibrium data of tertpentanol in carbon dioxide were measured at temperatures of 313.4,323.4,333.5 and 343.5 K and in the pressure range of 4.56-11.44 MPa.The phase equilibium apparatus used in the work was a variable-volume high-pressure cell.The experimental data were reasonably correlated with Peng-Robinson equation of state(PR-EOS) together with van der Waals-2 two-parameter mixing rules.Henry's Law constants and partial molar volumes of CO2 at infinite dilution were estimated with Krichevsky-Kasarnovsky equation,and Henry's Law constants increase with increasing temperature,however,partial molar volumes of CO2 at infinite dilution are negative whose magnitudes decrease with temperature.Partial molar volumes of CO2 and tertpentanol in liquid phase at equilibrium were calculated.

  4. Vapor pressures, thermodynamic stability, and fluorescence properties of three 2,6-alkyl naphthalenes.

    Science.gov (United States)

    Santos, Ana Filipa L O M; Oliveira, Juliana A S A; Ribeiro da Silva, Maria D M C; Monte, Manuel J S

    2016-03-01

    This work reports the experimental determination of relevant thermodynamic properties and the characterization of luminescence properties of the following polycyclic aromatic hydrocarbons (PAHs): 2,6-diethylnaphthalene, 2,6-diisopropylnaphthalene and 2,6-di-tert-butylnaphthalene. The standard (p(o) = 0.1 MPa) molar enthalpies of combustion, ΔcHm(o), of the three compounds were determined using static bomb combustion calorimetry. The vapor pressures of the crystalline phase of 2,6-diisopropylnaphthalene and 2,6-di-tert-butylnaphthalene were measured at different temperatures using the Knudsen effusion method and the vapor pressures of both liquid and crystalline phases of 2,6-diethylnaphthalene were measured by means of a static method. The temperatures and the molar enthalpies of fusion of the three compounds were determined using differential scanning calorimetry. The gas-phase molar heat capacities and absolute entropies of the three 2,6-dialkylnaphthalenes studied were determined computationally. The thermodynamic stability of the compounds in both the crystalline and gaseous phases was evaluated by the determination of the Gibbs energies of formation and compared with the ones reported in the literature for 2,6-dimethylnaphthalene. From fluorescence spectroscopy measurements, the optical properties of the compounds studied and of naphthalene were evaluated in solution and in the solid state. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. The functional dependence of canopy conductance on water vapor pressure deficit revisited

    Science.gov (United States)

    Fuchs, Marcel; Stanghellini, Cecilia

    2018-03-01

    Current research seeking to relate between ambient water vapor deficit (D) and foliage conductance (g F ) derives a canopy conductance (g W ) from measured transpiration by inverting the coupled transpiration model to yield g W = m - n ln(D) where m and n are fitting parameters. In contrast, this paper demonstrates that the relation between coupled g W and D is g W = AP/D + B, where P is the barometric pressure, A is the radiative term, and B is the convective term coefficient of the Penman-Monteith equation. A and B are functions of g F and of meteorological parameters but are mathematically independent of D. Keeping A and B constant implies constancy of g F . With these premises, the derived g W is a hyperbolic function of D resembling the logarithmic expression, in contradiction with the pre-set constancy of g F . Calculations with random inputs that ensure independence between g F and D reproduce published experimental scatter plots that display a dependence between g W and D in contradiction with the premises. For this reason, the dependence of g W on D is a computational artifact unrelated to any real effect of ambient humidity on stomatal aperture and closure. Data collected in a maize field confirm the inadequacy of the logarithmic function to quantify the relation between canopy conductance and vapor pressure deficit.

  6. Rapid Chemical Vapor Infiltration of Silicon Carbide Minicomposites at Atmospheric Pressure.

    Science.gov (United States)

    Petroski, Kenneth; Poges, Shannon; Monteleone, Chris; Grady, Joseph; Bhatt, Ram; Suib, Steven L

    2018-02-07

    The chemical vapor infiltration technique is one of the most popular for the fabrication of the matrix portion of a ceramic matrix composite. This work focuses on tailoring an atmospheric pressure deposition of silicon carbide onto carbon fiber tows using the methyltrichlorosilane (CH 3 SiCl 3 ) and H 2 deposition system at atmospheric pressure to create minicomposites faster than low pressure systems. Adjustment of the flow rate of H 2 bubbled through CH 3 SiCl 3 will improve the uniformity of the deposition as well as infiltrate the substrate more completely as the flow rate is decreased. Low pressure depositions conducted at 50 Torr deposit SiC at a rate of approximately 200 nm*h -1 , while the atmospheric pressure system presented has a deposition rate ranging from 750 nm*h -1 to 3.88 μm*h -1 . The minicomposites fabricated in this study had approximate total porosities of 3 and 6% for 10 and 25 SCCM infiltrations, respectively.

  7. High-pressure catalytic chemical vapor deposition of ferromagnetic ruthenium-containing carbon nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Khavrus, Vyacheslav O., E-mail: V.Khavrus@ifw-dresden.de; Ibrahim, E. M. M.; Bachmatiuk, Alicja; Ruemmeli, Mark H.; Wolter, A. U. B.; Hampel, Silke; Leonhardt, Albrecht [IFW Dresden (Germany)

    2012-06-15

    We report on the high-pressure catalytic chemical vapor deposition (CCVD) of ruthenium nanoparticles (NPs) and single-walled carbon nanotubes (SWCNTs) by means of gas-phase decomposition of acetonitrile and ruthenocene in a tubular quartz flow reactor at 950 Degree-Sign C and at elevated pressures (between 2 and 8 bar). The deposited material consists of Ru metal cores with sizes ranging between 1 and 3 nm surrounded by a carbon matrix. The high-pressure CCVD seems to be an effective route to obtain composite materials containing metallic NPs, Ru in this work, inside a nanostructured carbon matrix protecting them from oxidation in ambient air. We find that in contradiction to the weak paramagnetic properties characterizing bulk ruthenium, the synthesized samples are ferromagnetic as predicted for nanosized particles of nonmagnetic materials. At low pressure, the very small ruthenium catalyst particles are able to catalyze growth of SWCNTs. Their yield decreases with increasing reaction pressure. Transmission electron microscopy, selected area energy-dispersive X-ray analysis, Raman spectroscopy, and magnetic measurements were used to analyze and confirm properties of the synthesized NPs and nanotubes. A discussion on the growth mechanism of the Ru-containing nanostructures is presented.

  8. Kinetics of low pressure chemical vapor deposition of tungsten silicide from dichlorocilane reduction of tungsten hexafluoride

    International Nuclear Information System (INIS)

    Srinivas, D.; Raupp, G.B.; Hillman, J.

    1990-01-01

    The authors report on experiments to determine the intrinsic surface reaction rate dependences and film properties' dependence on local reactant partial pressures and wafer temperature in low pressure chemical vapor deposition (LPCVD) of tungsten silicide from dichlorosilane reduction of tungsten hexafluoride. Films were deposited in a commercial-scale Spectrum CVD cold wall single wafer reactor under near differential, gradientless conditions. Over the range of process conditions investigated, deposition rate was found to be first order in dichlorosillane and negative second order in tungsten hexafluoride partial pressure. The apparent activation energy in the surface reaction limited regime was found to be 70-120 kcal/mol. The silicon to tungsten ratio of as deposited silicide films ranged from 1.1 to 2.4, and increased with increasing temperature and dichlorosillane partial pressure, and decreased with increasing tungsten hexafluoride pressure. These results suggest that the apparent silicide deposition rate and composition are controlled by the relative rates of at least two competing reactions which deposit stoichiometric tungsten silicides and/or silicon

  9. Phosphorus atomic layer doping in SiGe using reduced pressure chemical vapor deposition

    International Nuclear Information System (INIS)

    Yamamoto, Yuji; Heinemann, Bernd; Murota, Junichi; Tillack, Bernd

    2014-01-01

    Phosphorus (P) atomic layer doping in SiGe is investigated at temperatures between 100 °C to 600 °C using a single wafer reduced pressure chemical vapor deposition system. SiGe(100) surface is exposed to PH 3 at different PH 3 partial pressures by interrupting SiGe growth. The impact of the SiGe buffer/cap growth condition (total pressure/SiGe deposition precursors) on P adsorption, incorporation, and segregation are investigated. In the case of SiH 4 -GeH 4 -H 2 gas system, steeper P spikes due to lower segregation are observed by SiGe cap deposition at atmospheric (ATM) pressure compared with reduced pressure (RP). The steepness of P spike of ∼ 5.7 nm/dec is obtained for ATM pressure without reducing deposition temperature. This result may be due to the shift of equilibrium of P adsorption/desorption to desorption direction by higher H 2 pressure. Using Si 2 H 6 -GeH 4 -H 2 gas system for SiGe cap deposition in RP, lowering the SiGe growth temperature is possible, resulting in higher P incorporation and steeper P profile due to reduced desorption and segregation. In the case of Si 2 H 6 -GeH 4 -H 2 gas system, the P dose could be simulated assuming a Langmuir-type kinetics model. Incorporated P shows high electrical activity, indicating P is adsorbed mostly in lattice position. - Highlights: • Phosphorus (P) atomic layer doping in SiGe (100) is investigated using CVD. • P adsorption is suppressed by the hydrogen termination of Ge surface. • By SiGe cap deposition at atmospheric pressure, P segregation was suppressed. • By using Si 2 H 6 -based SiGe cap, P segregation was also suppressed. • The P adsorption process is self-limited and follows Langmuir-type kinetics model

  10. Relation of average and highest solvent vapor concentrations in workplaces in small to medium enterprises and large enterprises.

    Science.gov (United States)

    Ukai, Hirohiko; Ohashi, Fumiko; Samoto, Hajime; Fukui, Yoshinari; Okamoto, Satoru; Moriguchi, Jiro; Ezaki, Takafumi; Takada, Shiro; Ikeda, Masayuki

    2006-04-01

    The present study was initiated to examine the relationship between the workplace concentrations and the estimated highest concentrations in solvent workplaces (SWPs), with special references to enterprise size and types of solvent work. Results of survey conducted in 1010 SWPs in 156 enterprises were taken as a database. Workplace air was sampled at > or = 5 crosses in each SWP following a grid sampling strategy. An additional air was grab-sampled at the site where the worker's exposure was estimated to be highest (estimated highest concentration or EHC). The samples were analyzed for 47 solvents designated by regulation, and solvent concentrations in each sample were summed up by use of additiveness formula. From the workplace concentrations at > or = 5 points, geometric mean and geometric standard deviations were calculated as the representative workplace concentration (RWC) and the indicator of variation in workplace concentration (VWC). Comparison between RWC and EHC in the total of 1010 SWPs showed that EHC was 1.2 (in large enterprises with>300 employees) to 1.7 times [in small to medium (SM) enterprises with enterprises and large enterprises, both RWC and EHC were significantly higher in SM enterprises than in large enterprises. Further comparison by types of solvent work showed that the difference was more marked in printing, surface coating and degreasing/cleaning/wiping SWPs, whereas it was less remarkable in painting SWPs and essentially nil in testing/research laboratories. In conclusion, the present observation as discussed in reference to previous publications suggests that RWC, EHC and the ratio of EHC/WRC varies substantially among different types of solvent work as well as enterprise size, and are typically higher in printing SWPs in SM enterprises.

  11. Vapor generation methods for explosives detection research

    Energy Technology Data Exchange (ETDEWEB)

    Grate, Jay W.; Ewing, Robert G.; Atkinson, David A.

    2012-12-01

    The generation of calibrated vapor samples of explosives compounds remains a challenge due to the low vapor pressures of the explosives, adsorption of explosives on container and tubing walls, and the requirement to manage (typically) multiple temperature zones as the vapor is generated, diluted, and delivered. Methods that have been described to generate vapors can be classified as continuous or pulsed flow vapor generators. Vapor sources for continuous flow generators are typically explosives compounds supported on a solid support, or compounds contained in a permeation or diffusion device. Sources are held at elevated isothermal temperatures. Similar sources can be used for pulsed vapor generators; however, pulsed systems may also use injection of solutions onto heated surfaces with generation of both solvent and explosives vapors, transient peaks from a gas chromatograph, or vapors generated by s programmed thermal desorption. This article reviews vapor generator approaches with emphasis on the method of generating the vapors and on practical aspects of vapor dilution and handling. In addition, a gas chromatographic system with two ovens that is configurable with up to four heating ropes is proposed that could serve as a single integrated platform for explosives vapor generation and device testing. Issues related to standards, calibration, and safety are also discussed.

  12. Experimental study on the performance of the vapor injection refrigeration system with an economizer for intermediate pressures

    Science.gov (United States)

    Moon, Chang-Uk; Choi, Kwang-Hwan; Yoon, Jung-In; Kim, Young-Bok; Son, Chang-Hyo; Ha, Soo-Jung; Jeon, Min-Ju; An, Sang-Young; Lee, Joon-Hyuk

    2018-04-01

    In this study, to investigate the performance characteristics of vapor injection refrigeration system with an economizer at an intermediate pressure, the vapor injection refrigeration system was analyzed under various experiment conditions. As a result, the optimum design data of the vapor injection refrigeration system with an economizer were obtained. The findings from this study can be summarized as follows. The mass flow rate through the compressor increases with intermediate pressure. The compression power input showed an increasing trend under all the test conditions. The evaporation capacity increased and then decreased at the intermediate pressure, and as such, it became maximum at the given intermediate pressure. The increased mass flow rate of the by-passed refrigerant enhanced the evaporation capacity at the low medium pressure range, but the increased saturation temperature limited the subcooling degree of the liquid refrigerant after the application of the economizer when the intermediate pressure kept rising, and degenerated the evaporation capacity. The coefficient of performance (COP) increased and then decreased with respect to the intermediate pressures under all the experiment conditions. Nevertheless, there was an optimum intermediate pressure for the maximum COP under each experiment condition. Therefore, the optimum intermediate pressure in this study was found at -99.08 kPa, which is the theoretical standard medium pressure under all the test conditions.

  13. High Pressure Oxydesulphurisation of Coal—Effect of Oxidizing Agent, Solvent, Shear and Agitator Configuration

    Directory of Open Access Journals (Sweden)

    Moinuddin Ghauri

    2016-06-01

    Full Text Available The ambient temperature high pressure oxydesulphurisation technique was investigated to reduce the sulphur content. Prince of Wales coal was chosen for this study. The focus of the study was to investigate the reduction of both pyritic and organic sulphur while changing the KMnO4/Coal ratio, agitation speed, agitator configuration, and shear. The effect of different concentrations of acetone as a solvent and effect of particle size on the sulphur removal was also studied by a series of experimental runs at ambient temperature. Heating value recovery was found to be increased with the decreased KMnO4/Coal ratio and with decreased acetone concentration. It was found that sulphur removal was enhanced with the increase in shear using a turbine impeller. The effect of particle size was more significant on the pyritic sulphur removal as compared to the organic sulphur removal while heating value recovery was found to increase with decreased desulphurization tome for both, under atmospheric and high pressure.

  14. Net vapor generation point in boiling flow of trichlorotrifluoroethane at high pressures

    Science.gov (United States)

    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.

  15. The optimum intermediate pressure of two-stages vapor compression refrigeration cycle for Air-Conditioning unit

    Science.gov (United States)

    Ambarita, H.; Sihombing, H. V.

    2018-03-01

    Vapor compression cycle is mainly employed as a refrigeration cycle in the Air-Conditioning (AC) unit. In order to save energy, the Coefficient of Performance (COP) of the need to be improved. One of the potential solutions is to modify the system into multi-stages vapor compression cycle. The suitable intermediate pressure between the high and low pressures is one of the design issues. The present work deals with the investigation of an optimum intermediate pressure of two-stages vapor compression refrigeration cycle. Typical vapor compression cycle that is used in AC unit is taken into consideration. The used refrigerants are R134a. The governing equations have been developed for the systems. An inhouse program has been developed to solve the problem. COP, mass flow rate of the refrigerant and compressor power as a function of intermediate pressure are plotted. It was shown that there exists an optimum intermediate pressure for maximum COP. For refrigerant R134a, the proposed correlations need to be revised.

  16. Measurement and modeling of high-pressure (vapor + liquid) equilibria of (CO{sub 2} + alkanol) binary systems

    Energy Technology Data Exchange (ETDEWEB)

    Bejarano, Arturo; Gutierrez, Jorge E. [Departamento de Ingenieria Quimica y Ambiental, Universidad Tecnica Federico Santa Maria, Avda. Espana 1680, Valparaiso (Chile); Araus, Karina A. [Departamento de Ingenieria Quimica y Bioprocesos, Pontificia Universidad Catolica de Chile, Avda. Vicuna Mackenna 4860, Macul, Santiago (Chile); Fuente, Juan C. de la, E-mail: juan.delafuente@usm.c [Departamento de Ingenieria Quimica y Ambiental, Universidad Tecnica Federico Santa Maria, Avda. Espana 1680, Valparaiso (Chile); Centro Regional de Estudios en Alimentos Saludables, Blanco 1623, Valparaiso (Chile)

    2011-05-15

    Research highlights: (Vapor + liquid) equilibria of three (CO{sub 2} + C{sub 5} alcohol) binary systems were measured. Complementary data are reported at (313, 323 and 333) K and from (2 to 11) MPa. No liquid immiscibility was observed at the temperatures and pressures studied. Experimental data were correlated with the PR-EoS and the van de Waals mixing rules. Correlation results showed relative deviations {<=}8 % (liquid) and {<=}2 % (vapor). - Abstract: Complementary isothermal (vapor + liquid) equilibria data are reported for the (CO{sub 2} + 3-methyl-2-butanol), (CO{sub 2} + 2-pentanol), and (CO{sub 2} + 3-pentanol) binary systems at temperatures of (313, 323, and 333) K, and at pressure range of (2 to 11) MPa. For all (CO{sub 2} + alcohol) systems, it was visually monitored that there was no liquid immiscibility at the temperatures and pressures studied. The experimental data were correlated with the Peng-Robinson equation of state using the quadratic mixing rules of van der Waals with two adjustable parameters. The calculated (vapor + liquid) equilibria compositions were found to be in good agreement with the experimental data with deviations for the mole fractions <8% and <2% for the liquid and vapor phase, respectively.

  17. Reduced-pressure chemical vapor deposition of boron-doped Si and Ge layers

    International Nuclear Information System (INIS)

    Bogumilowicz, Y.; Hartmann, J.M.

    2014-01-01

    We have studied the in-situ boron (B) doping of germanium (Ge) and silicon (Si) in Reduced Pressure-Chemical Vapor Deposition. Three growth temperatures have been investigated for the B-doping of Ge: 400, 600 and 750 °C at a constant growth pressure of 13300 Pa (i.e. 100 Torr). The B concentration in the Ge:B epilayer increases linearly with the diborane concentration in the gaseous phase. Single-crystalline Ge:B layers with B concentrations in-between 9 ∙ 10 17 and 1 ∙ 10 20 cm −3 were achieved. For the in-situ B doping of Si at 850 °C, two dichlorosilane mass flow ratios (MFR) have been assessed: F[SiH 2 Cl 2 ]/F[H 2 ] = 0.0025 and F[SiH 2 Cl 2 ]/F[H 2 ] = 0.0113 at a growth pressure of 2660 Pa (i.e. 20 Torr). Linear boron incorporation with the diborane concentration in the gas phase has been observed and doping levels in-between 3.5 ∙ 10 17 and 1 ∙ 10 20 cm −3 were achieved. We almost kept the same ratio of B versus Si atoms in the gas phase and in the Si epilayer. By contrast, roughly half of the B atoms present in the gas phase were incorporated in the Ge:B layers irrespective of the growth temperature. X-Ray Diffraction (XRD) allowed us to extract from the angular position of the Ge:B layer diffraction peak the substitutional B concentration. Values close to the B concentrations obtained by 4-probe resistivity measurements were obtained. Ge:B layers were smooth (< 1 m root mean square roughness associated with 20 × 20 μm 2 Atomic Force Microscopy images). Only for high F[B 2 H 6 ]/F[GeH 4 ] MFR (3.2 10 −3 ) did the Ge:B layers became rough; they were however still mono-crystalline (XRD). Above this MFR value, Ge:B layers became polycrystalline. - Highlights: • Boron doping of germanium and silicon in Reduced Pressure-Chemical Vapor Deposition • Linear boron incorporation in Ge:B and Si:B with the diborane flow • Single-crystal Ge:B layers with B concentrations in-between 9 ∙ 10 17 and 1 ∙ 10 20 cm −3 • Single-crystal Si

  18. Comparative X-ray photoelectron spectroscopy study of plasma enhanced chemical vapor deposition and micro pressure chemical vapor deposition of phosphorus silicate glass layers after rapid thermal annealing

    International Nuclear Information System (INIS)

    Beshkov, G.; Krastev, V.; Gogova, D.; Talik, E.; Adamies, M.

    2008-01-01

    In this paper the bonding state of Phosphorus Silicate Glass (PSG) layers obtained by two different technological approaches, i.e. in two types of reactors: Plasma Enhanced Chemical Vapor Deposition (PECVD) and Micro Pressure Chemical Vapor Deposition (MPCVD) are investigated employing XPS and AES. The PSG layers are deposited at 380 0 C and 420 0 C in corresponding reactors. XPS and AES analyses show that Si2p peak recorded from PECVD layers are not as expected at their position characteristics of silicon dioxide but instead they are at the characteristic of elemental silicon. Plasma enhancement during deposition leads to less oxidized and more inhomogeneous layer. After rapid thermal annealing the Si2p peak is situated at position characteristic of silicon dioxide. (authors)

  19. The Comparative Study on Vapor-Polymerization and Pressure-dependent Conductance Behavior in Polypyrrole-hybridized Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Hanif, Zahid; Lee, Seyeong; Arsalani, Nasir; Geckeler, Kurt E.; Hong, Sukwon; Yoon, Myung-Han [Gwangju Institute of Science and Technology, Gwangju (Korea, Republic of)

    2016-02-15

    In this study, commercially available cellulose membranes were hybridized with conjugated polymer via vapor-phase polymerization using pyrrole and iron chloride as a monomer and oxidant, respectively. The iron (III) chloride layer dip-coated on the hydrophilic cell ulose surface oxidized the vaporized pyrrole monomer leading to the polypyrrole-cellulose hybrid membrane. The conductivity of hybrid membrane was optimized by varying the oxidant concentration and the monomer vapor exposure time. The various surface characterizations of polypyrrole-cellulose hybrid membrane show that the conductive polypyrrole layer was uniformly deposited onto the surface of cellulose fibrous networks unlike the polypyrrole-nylonhybrid membrane prepared in the similar way. The polypyrrole-incorporated cellulose networks exhibits steeper electrical conductance increase over the vertical pressure than its nylon counterpart. Our result suggests that the polypyrrole-cellulose hybrid membrane can be applicable for a disposable high-load pressure sensor.

  20. The Comparative Study on Vapor-Polymerization and Pressure-dependent Conductance Behavior in Polypyrrole-hybridized Membranes

    International Nuclear Information System (INIS)

    Hanif, Zahid; Lee, Seyeong; Arsalani, Nasir; Geckeler, Kurt E.; Hong, Sukwon; Yoon, Myung-Han

    2016-01-01

    In this study, commercially available cellulose membranes were hybridized with conjugated polymer via vapor-phase polymerization using pyrrole and iron chloride as a monomer and oxidant, respectively. The iron (III) chloride layer dip-coated on the hydrophilic cell ulose surface oxidized the vaporized pyrrole monomer leading to the polypyrrole-cellulose hybrid membrane. The conductivity of hybrid membrane was optimized by varying the oxidant concentration and the monomer vapor exposure time. The various surface characterizations of polypyrrole-cellulose hybrid membrane show that the conductive polypyrrole layer was uniformly deposited onto the surface of cellulose fibrous networks unlike the polypyrrole-nylonhybrid membrane prepared in the similar way. The polypyrrole-incorporated cellulose networks exhibits steeper electrical conductance increase over the vertical pressure than its nylon counterpart. Our result suggests that the polypyrrole-cellulose hybrid membrane can be applicable for a disposable high-load pressure sensor.

  1. [Measurement of atomic number of alkali vapor and pressure of buffer gas based on atomic absorption].

    Science.gov (United States)

    Zheng, Hui-jie; Quan, Wei; Liu, Xiang; Chen, Yao; Lu, Ji-xi

    2015-02-01

    High sensitivitymagnetic measurementscanbe achieved by utilizing atomic spinmanipulation in the spin-exchange-relaxation-free (SERF) regime, which uses an alkali cell as a sensing element. The atomic number density of the alkali vapor and the pressure of the buffer gasare among the most important parameters of the cell andrequire accurate measurement. A method has been proposed and developedto measure the atomic number density and the pressure based on absorption spectroscopy, by sweeping the absorption line and fittingthe experiment data with a Lorentzian profile to obtainboth parameters. Due to Doppler broadening and pressure broadening, which is mainly dominated by the temperature of the cell and the pressure of buffer gas respectively, this work demonstrates a simulation of the errorbetween the peaks of the Lorentzian profile and the Voigt profile caused by bothfactors. The results indicates that the Doppler broadening contribution is insignificant with an error less than 0.015% at 313-513 K for a 4He density of 2 amg, and an error of 0.1% in the presence of 0.6-5 amg at 393 K. We conclude that the Doppler broadening could be ignored under above conditions, and that the Lorentzianprofile is suitably applied to fit the absorption spectrumobtainingboth parameters simultaneously. In addition we discuss the resolution and the instability due to thelight source, wavelength and the temperature of the cell. We find that the cell temperature, whose uncertainty is two orders of magnitude larger than the instability of the light source and the wavelength, is one of the main factors which contributes to the error.

  2. Self-organized morphological evolution and dewetting in solvent vapor annealing of spin coated polymer blend nanostructures.

    Science.gov (United States)

    Roy, Sudeshna; Sharma, Ashutosh

    2015-07-01

    Dewetting pathways, kinetics and morphologies of thin films of phase separating polymer blends are governed by the relative mobilities of the two components. We characterize the morphological transformations of the nanostructures of a PS/PMMA blend by annealing in toluene and chloroform vapors. Toluene leads to faster reorganization of PS, whereas chloroform engenders the opposite effect. Spin coating produces a very rough PMMA rich layer that completely wets the substrate and forms a plethora of slender columns protruding through the continuous PS rich layer on top. The nanostructures were stable under long thermal annealing but in the vapor annealing, phase separation and dewetting occurred readily to form the equilibrium structures of dewetted droplets of PS on top of PMMA which also climbed around the PS droplets to form rims. Toluene and chloroform annealing required around 50 h and 1 h respectively to attain the equilibrium. Substantial differences are observed in the intermediate morphologies (heights of nanostructures, roughness and size). PMMA columns remained embedded in the dewetted PS droplets, whereas a high mobility of PMMA in chloroform allowed its rapid evacuation during dewetting to produce an intermediate swiss-cheese like morphology of PS domains. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. An Integrated Approach to Introducing Biofuels, Flash Point, and Vapor Pressure Concepts into an Introductory College Chemistry Lab

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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...

  5. Vapor pressure and evaporation rate of certain heat-resistant compounds in a vacuum at high temperatures

    Science.gov (United States)

    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.

  6. Vapor pressure isotope effect in 13CClF3/12CClF3 by cryogenic distillation kinetics

    International Nuclear Information System (INIS)

    Wieck, H.J.; Ishida, T.

    1975-08-01

    The vapor pressure of 13 CClF 3 relative to the vapor pressure of 12 CClF 3 was measured as a function of temperature between 169 0 and 206 0 K by using a modified Bigeleisen distillation column. The transient build-up of the isotopic concentration gradient along the length of the packed column during the start-up period was monitored by taking samples from the condenser section as a function of time. The gaseous samples were completely oxidized to carbon dioxide in the presence of a platinum catalyst and a large excess of oxygen at temperatures between 1050 and 1100 0 C. The combustion products were purified by means of gas chromatography, and the purified carbon dioxide samples were analyzed in a Nier-type isotope-ratio mass spectrometer. The data of each distillation run were reduced in the light of Cohen's theory of the kinetics of square cascade of close-separation stages. The vapor pressure isotope effect for the carbon substitution in CClF 3 at temperatures between 169 0 and 206 0 K was found to be an inverse effect and to be rather insensitive to changes in temperature. The relative vapor pressure may be expressed 1n(P'/P) = [(1.5 +- 14.1)/T 2 ] - [(0.159 +- 0.076)/T], or 1n(P'/P) = [(0.173 +- 0.098)/T] - [(0.11 +- 0.53) x 10 -3 ], where P' and P are the vapor pressures of 12 CClF 3 and 13 CClF 3 , respectively. To the first-order, the presence of chlorine isotopes would not affect the fractionation of carbon isotopes by the distillation of CClF 3

  7. Deep eutectic solvents for highly efficient separations in oil and gas industries

    NARCIS (Netherlands)

    Warrag, S.E.E.; Peters, C.J.; Kroon, M.C.

    2017-01-01

    Deep eutectic solvents (DESs) have captured a great scientific attention as a new, ‘green’ and sustainable class of tailor-made solvents. DESs share many properties with ionic liquids (ILs) including low vapor pressure, wide liquid range, thermal stability, low flammability, and high solvation

  8. Methods for calculation of engineering parameters for gas separation. [vapor pressure and solubility of gases in organic liquids

    Science.gov (United States)

    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.

  9. Exchange of Na+ and K+ between water vapor and feldspar phases at high temperature and low vapor pressure

    Science.gov (United States)

    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.

  10. Calculation of vapor pressures of oxide fuels up to 5,000 K for equilibrium and nonequilibrium evaporation

    International Nuclear Information System (INIS)

    Breitung, W.

    1975-06-01

    In the first part of this work the evaporation kinetics of multicomponent systems is studied with UO 2 as the example. The evaporation, which is generally incongruent, implies that two opposing types of steady-state evaporation must be distinguished: equilibrium evaporation and 'forced congruent' evaporation. The two types of evaporation indicated entail different vapor pressures. In some prompt critical reactor incidents forced congruent evaporation must be anticipated. The second part of this work contains the calculation of the vapor pressures of UOsub(2+-x) and (U,Pu)Osub(2+-x) for both types of evaporation up to temperature of 5,000 K. The calculating procedures are based on the method of Rand and Markin (1967) incorporating the recent thermodynamic data. The agreement between the measured and calculated total pressures is good for the ranges of temperature and stoichiometry for which experimental results are available. This supports the results calculated for higher temperature ranges. (orig./UA) [de

  11. Effect of Furnish on Temperature and Vapor Pressure Behavior in the Center of Mat Panels during Hot Pressing

    Directory of Open Access Journals (Sweden)

    Muhammad Navis Rofii

    2014-07-01

    Full Text Available Particleboard achieves its overall performance characteristics during hot pressing process. As this process is influenced by several factors, particularly temperature and pressure, it is very important to understand the behavior of both. This study investigates the effects of furnish materials on temperature and vapor pressure behavior inside particleboard mat panels during hot pressing. Strand type particles from hinoki and ring-flaker recycled wood particles were used as furnish for laboratory-scale particleboard panels with a target density of 0.76 g/cm³. Mat panels with a moisture content of about 10% were hot pressed at a platen temperature of 180°C and an initial pressure of 3 MPa until the mat center reached the same temperature as the platen. A press monitoring device (PressMAN Lite was used for detecting the temperature and vapor pressure change in the center of the mat panels. The study showed that the furnish type affected the temperature and vapor behavior inside the mat panels. Particleboard made of hinoki strand resulted in a longer plateau time, a higher plateau temperature and a higher gas pressure generated during hot pressing than those of ring-flaker recycled wood particles. Mixed board resulted in values between those of the two other furnish materials.

  12. Solvent extraction

    Energy Technology Data Exchange (ETDEWEB)

    Coombs, D.M.; Latimer, E.G.

    1988-01-05

    It is an object of this invention to provide for the demetallization and general upgrading of heavy oil via a solvent extracton process, and to improve the efficiency of solvent extraction operations. The yield and demetallization of product oil form heavy high-metal content oil is maximized by solvent extractions which employ either or all of the following techniques: premixing of a minor amount of the solvent with feed and using countercurrent flow for the remaining solvent; use of certain solvent/free ratios; use of segmental baffle tray extraction column internals and the proper extraction column residence time. The solvent premix/countercurrent flow feature of the invention substantially improves extractions where temperatures and pressures above the critical point of the solvent are used. By using this technique, a greater yield of extract oil can be obtained at the same metals content or a lower metals-containing extract oil product can be obtained at the same yield. Furthermore, the premixing of part of the solvent with the feed before countercurrent extraction gives high extract oil yields and high quality demetallization. The solvent/feed ratio features of the invention substanially lower the captial and operating costs for such processes while not suffering a loss in selectivity for metals rejection. The column internals and rsidence time features of the invention further improve the extractor metals rejection at a constant yield or allow for an increase in extract oil yield at a constant extract oil metals content. 13 figs., 3 tabs.

  13. Complementary vapor pressure data for 2-methyl-1-propanol and 3-methyl-1-butanol at a pressure range of (15 to 177) kPa

    Energy Technology Data Exchange (ETDEWEB)

    Bejarano, Arturo; Quezada, Nathalie [Departamento de Ingenieria Quimica y Ambiental, Universidad Tecnica Federico Santa Maria, Avda. Espana 1680, Valparaiso (Chile); Fuente, Juan C. de la [Departamento de Ingenieria Quimica y Ambiental, Universidad Tecnica Federico Santa Maria, Avda. Espana 1680, Valparaiso (Chile)], E-mail: juan.delafuente@usm.cl

    2009-09-15

    The vapor pressure of pure 2-methyl-1-propanol and 3-methyl-1-butanol, components called congeners that are present in aroma of wine, pisco, and other alcoholic beverages, were measured with a dynamic recirculation apparatus at a pressure range of (15 to 177) kPa with an estimated uncertainty <0.2%. The measurements were performed at temperature ranges of (337 to 392) K for 2-methyl-1-propanol and (358 to 422) K for 3-methyl-1-butanol. Data were correlated using a Wagner-type equation with standard deviations of 0.09 kPa for the vapor pressure of 2-methyl-1-propanol and 0.21 kPa for 3-methyl-1-butanol. The experimental data and correlation were compared with data selected from the literature.

  14. Atmospheric Pressure Spray Chemical Vapor Deposited CuInS2 Thin Films for Photovoltaic Applications

    Science.gov (United States)

    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. [Determination and prediction for vapor pressures of organophosphate flame retardants by gas chromatography].

    Science.gov (United States)

    Wang, Qingzhi; Zhao, Hongxia; Wang, Yan; Xie, Qing; Chen, Jingwen; Quan, Xie

    2017-09-08

    Organophosphate flame retardants (OPFRs) are ubiquitous in the environment. To better understand and predict their environmental transport and fate, well-defined physicochemical properties are required. Vapor pressures ( P ) of 14 OPFRs were estimated as a function of temperature ( T ) by gas chromatography (GC), while 1,1,1-trichioro-2,2-bis (4-chlorophenyl) ethane ( p,p '-DDT) was acted as a reference substance. Their log P GC values and internal energies of phase transfer (△ vap H ) ranged from -6.17 to -1.25 and 74.1 kJ/mol to 122 kJ/mol, respectively. Substitution pattern and molar volume ( V M ) were found to be capable of influencing log P GC values of the OPFRs. The halogenated alkyl-OPFRs had lower log P GC values than aryl-or alkyl-OPFRs. The bigger the molar volume was, the smaller the log P GC value was. In addition, a quantitative structure-property relationship (QSPR) model of log P GC versus different relative retention times (RRTs) was developed with a high cross-validated value ( Q 2 cum ) of 0.946, indicating a good predictive ability and stability. Therefore, the log P GC values of the OPFRs without standard substance can be predicted by using their RRTs on different GC columns.

  16. Uniformly Distributed Graphene Domain Grows on Standing Copper via Low-Pressure Chemical Vapor Deposition

    Directory of Open Access Journals (Sweden)

    Shih-Hao Chan

    2013-01-01

    Full Text Available Uniformly distributed graphene domains were synthesized on standing copper foil by a low-pressure chemical vapor deposition system. This method improved the distribution of the graphene domains at different positions on the same piece of copper foil along the forward direction of the gas flow. Scanning electron microscopy (SEM showed the average size of the graphene domains to be about ~20 m. This results show that the sheet resistance of monolayer graphene on a polyethylene terephthalate (PET substrate is about ~359 /□ whereas that of the four-layer graphene films is about ~178 /□, with a transmittance value of 88.86% at the 550 nm wavelength. Furthermore, the sheet resistance can be reduced with the addition of HNO3 resulting in a value of 84 /□. These values meet the absolute standard for touch sensor applications, so we believe that this method can be a candidate for some transparent conductive electrode applications.

  17. Vapor Pressure and Predicted Stability of American Contact Dermatitis Society Core Allergens

    Science.gov (United States)

    Jou, Paul C.; Siegel, Paul D.; Warshaw, Erin M.

    2018-01-01

    Background Accurate patch testing is reliant on proper preparation of patch test allergens. The stability of patch test allergens is dependent on several factors including vapor pressure (VP). Objective This investigation reviews the VP of American Contact Dermatitis Society Core Allergens and compares stability predictions based on VP with those established through clinical testing. Methods Standard references were accessed for determining VP in millimeters of mercury and associated temperature in degrees celsius. If multiple values were listed, VP at temperatures that most approximate indoor storage conditions (20°C and 25°C) were chosen. For mixes, the individual component with the highest VP was chosen as the overall VP, assuming that the most volatile substance would evaporate first. Antigens were grouped into low (≤0.001 mm Hg), moderate (0.001 mm Hg), and high (≥1 mm Hg) volatility using arbitrary cutoff values. Conclusions This review is consistent with previously reported data on formaldehyde, acrylates, and fragrance material instability. Given lack of testing data, VP can be useful in predicting patch test compound stability. Measures such as air-tight multidose reagent containers, sealed single-application dispensers, preparation of patches immediately before application, and storage at lower temperatures may remedy some of these issues. PMID:27427821

  18. Diamond synthesis at atmospheric pressure by microwave capillary plasma chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Hemawan, Kadek W.; Gou, Huiyang; Hemley, Russell J. [Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Rd., NW, Washington, DC 20015 (United States)

    2015-11-02

    Polycrystalline diamond has been synthesized on silicon substrates at atmospheric pressure, using a microwave capillary plasma chemical vapor deposition technique. The CH{sub 4}/Ar plasma was generated inside of quartz capillary tubes using 2.45 GHz microwave excitation without adding H{sub 2} into the deposition gas chemistry. Electronically excited species of CN, C{sub 2}, Ar, N{sub 2}, CH, H{sub β}, and H{sub α} were observed in the emission spectra. Raman measurements of deposited material indicate the formation of well-crystallized diamond, as evidenced by the sharp T{sub 2g} phonon at 1333 cm{sup −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 μm.

  19. Water vapor pressure over molten KH_2PO_4 and demonstration of water electrolysis at ∼300 °C

    International Nuclear Information System (INIS)

    Berg, R.W.; Nikiforov, A.V.; Petrushina, I.M.; Bjerrum, N.J.

    2016-01-01

    Highlights: • The vapor pressure over molten KH_2PO_4 was measured by Raman spectroscopy to be about 8 bars at ∼300 °C. • Raman spectroscopy shows that molten KH_2PO_4 under its own vapor pressure contains much dissolved water. • It is demonstrated spectroscopically that water electrolysis is possible in KH_2PO_4 electrolyte forming H_2 and O_2 at 300 °C. • Molten KH_2PO_4 is a possible electrolyte for water electrolysis. - Abstract: A new potentially high-efficiency electrolyte for water electrolysis: molten monobasic potassium phosphate, KH_2PO_4 or KDP has been investigated at temperatures ∼275–325 °C. At these temperatures, KH_2PO_4 was found to dissociate into H_2O gas in equilibrium with a melt mixture of KH_2PO_4−K_2H_2P_2O_7−KPO_3−H_2O. The water vapor pressure above the melt, when contained in a closed ampoule, was determined quantitatively vs. temperature by use of Raman spectroscopy with methane or hydrogen gas as an internal calibration standard, using newly established relative ratios of Raman scattering cross sections of water and methane or hydrogen to be 0.40 ± 0.02 or 1.2 ± 0.03. At equilibrium the vapor pressure was much lower than the vapor pressure above liquid water at the same temperature. Electrolysis was realized by passing current through closed ampoules (vacuum sealed quartz glass electrolysis cells with platinum electrodes and the electrolyte melt). The formation of mixtures of hydrogen and oxygen gases as well as the water vapor was detected by Raman spectroscopy. In this way it was demonstrated that water is present in the new electrolyte: molten KH_2PO_4 can be split by electrolysis via the reaction 2H_2O → 2H_2 + O_2 at temperatures ∼275–325 °C. At these temperatures, before the start of the electrolysis, the KH_2PO_4 melt gives off H_2O gas that pressurizes the cell according to the following dissociations: 2KH_2PO_4 ↔ K_2H_2P_2O_7 + H_2O ↔ 2KPO_3 + 2H_2O. The spectra show however that the water by

  20. Experimental study on vapor explosion induced by pressure pulse in coarse mixing of hot molten metal and water

    International Nuclear Information System (INIS)

    Inoue, A.; Tobita, Y.; Aritomi, M.; Takahashi, M.; Matsuzaki, M.

    2004-01-01

    An experimental study was done to investigate characteristics of metal-water interaction, when a mount of hot liquid metal is injected into the water. The test section is a vertical shock tube of 60mm in inner diameter and 1200mm in length. A special injector which is designed to inject hot metal of controlled volume and flow rate is attached at the top of the tube. When the hot metal is injected in the water and comes down at a position of the test vessel, a trigger pressure pulse is generated at the bottom of the test tube. Local transient pressures along the tube are measured by piezo pressure transducers. The following items were investigated in the experiment; 1) The criteria to cause a vapor explosion, 2) Transient behaviors and propagation characteristics of pressure wave in the mixing region. 3) Effects of triggering pulse, injection temperature and mass of hot molten metal on the peak pressure. The probability of the vapor explosion jumped when the interface temperature at the molten metal-water direct contact is higher than the homogeneous nucleation temperature of water and the triggering pulse becomes larger than 0.9MPa. Two types of the pressure propagation modes are observed, one is the detonative mode with a sharp rise and other is usual pressure mode with a mild rise. (author)

  1. Challenges in the Structure Determination of Self-Assembled Metallacages: What Do Cage Cavities Contain, Internal Vapor Bubbles or Solvent and/or Counterions?

    Science.gov (United States)

    Givelet, Cecile C; Dron, Paul I; Wen, Jin; Magnera, Thomas F; Zamadar, Matibur; Čépe, Klára; Fujiwara, Hiroki; Shi, Yue; Tuchband, Michael R; Clark, Noel; Zbořil, Radek; Michl, Josef

    2016-05-25

    Proving the structures of charged metallacages obtained by metal ion coordination-driven solution self-assembly is challenging, and the common use of routine NMR spectroscopy and mass spectrometry is unreliable. Carefully determined diffusion coefficients from diffusion-ordered proton magnetic resonance (DOSY NMR) for six cages of widely differing sizes lead us to propose a structural reassignment of two molecular cages from a previously favored trimer to a pentamer or hexamer, and another from a trimer to a much higher oligomer, possibly an intriguing tetradecamer. In the former case, strong support for the reassignment to a larger cage is provided by an observation of a slow reversible transformation of the initially formed cage into a smaller but spectrally very similar one upon dilution. In the latter case, freeze-fracture transmission electron micrographs demonstrate that at least some of the solutions are colloidal, and high-resolution electron transmission and atomic force microscopy images are compatible with a tetradecamer but not a trimer. Comparison of solute partial molar volumes deduced from measurement of solution density with volumes anticipated from molecular models argues strongly against the presence of large voids (solvent vapor bubbles) in cages dissolved in nitromethane. The presence of bubbles was previously proposed in an attempt to account for the bilinear nature of the Eyring plot of the rate constant for pyridine ligand edge exchange reaction in one of the cages and for the unusual activation parameters in the high-temperature regime. An alternative interpretation is proposed now.

  2. Equilibrium water vapor pressures over polyvanadates M2V12O30.7·nH2O

    International Nuclear Information System (INIS)

    Volkov, V.L.; Zakharova, G.S.; Ivakin, A.A.

    1986-01-01

    Equilibrium pressures of water vapors over polyvanadates M 2 V 12 O 30.7 xnH 2 O where M=Li, Na, K are determined in the 293-343 K temperature range. Changes in Gibbs free energy and enthalpy of compound dehydration depending on water content in the final product are calculated on the basis of these data. Molar enthalpy of water is shown to reduce from lithium to potassium, while equilibrium pressure of water vapors over the compounds grows from lithium to potassium. Good correlation of thermodynamic properties of crystallization water of polyvanadates with energy characteristics of hydrated M + ions of the solutions confirms the conclusion that they cannot be attributed to ordinary crystallohydrates

  3. On the Origin of Light Emission in Silicon Rich Oxide Obtained by Low-Pressure Chemical Vapor Deposition

    OpenAIRE

    Aceves-Mijares, M.; González-Fernández, A. A.; López-Estopier, R.; Luna-López, A.; Berman-Mendoza, D.; Morales, A.; Falcony, C.; Domínguez, C.; Murphy-Arteaga, R.

    2012-01-01

    Silicon Rich Oxide (SRO) has been considered as a material to overcome the drawbacks of silicon to achieve optical functions. Various techniques can be used to produce it, including Low-Pressure Chemical Vapor Deposition (LPCVD). In this paper, a brief description of the studies carried out and discussions of the results obtained on electro-, cathode-, and photoluminescence properties of SRO prepared by LPCVD and annealed at 1,100°C are presented. The experimental results lead us to accept th...

  4. Satellite Estimation of Daily Land Surface Water Vapor Pressure Deficit from AMSR- E

    Science.gov (United States)

    Jones, L. A.; Kimball, J. S.; McDonald, K. C.; Chan, S. K.; Njoku, E. G.; Oechel, W. C.

    2007-12-01

    Vapor pressure deficit (VPD) is a key variable for monitoring land surface water and energy exchanges, and estimating plant water stress. Multi-frequency day/night brightness temperatures from the Advanced Microwave Scanning Radiometer on EOS Aqua (AMSR-E) were used to estimate daily minimum and average near surface (2 m) air temperatures across a North American boreal-Arctic transect. A simple method for determining daily mean VPD (Pa) from AMSR-E air temperature retrievals was developed and validated against observations across a regional network of eight study sites ranging from boreal grassland and forest to arctic tundra. The method assumes that the dew point and minimum daily air temperatures tend to equilibrate in areas with low night time temperatures and relatively moist conditions. This assumption was tested by comparing the VPD algorithm results derived from site daily temperature observations against results derived from AMSR-E retrieved temperatures alone. An error analysis was conducted to determine the amount of error introduced in VPD estimates given known levels of error in satellite retrieved temperatures. Results indicate that the assumption generally holds for the high latitude study sites except for arid locations in mid-summer. VPD estimates using the method with AMSR-E retrieved temperatures compare favorably with site observations. The method can be applied to land surface temperature retrievals from any sensor with day and night surface or near-surface thermal measurements and shows potential for inferring near-surface wetness conditions where dense vegetation may hinder surface soil moisture retrievals from low-frequency microwave sensors. This work was carried out at The University of Montana, at San Diego State University, and at the Jet Propulsion Laboratory, California Institute of Technology, under contract to the National Aeronautics and Space Administration.

  5. Vapor Pressure Deficit and Sap Velocity Dynamic Coupling in Canopy Dominant Trees in the Amazon basin

    Science.gov (United States)

    Chambers, J. Q.; Gimenez, B.; Jardine, K.; Negron Juarez, R. I.; Cobello, L. O.; Fontes, C.; Dawson, T. E.; Higuchi, N.

    2017-12-01

    In order to improve our ability to predict terrestrial water fluxes, an understanding of the interactions between plant physiology and environmental conditions is necessary, especially in tropical forests which recycle large fluxes of water to the atmosphere. This need has become more relevant due to observed records in global temperature. In this study we show a strong temporal correlation between sap velocity and leaf-to-air vapor pressure deficit (VPD) in canopy dominant trees in two primary rainforest sites in the Amazon basin (Santarém and Manaus, Brazil). As VPDs in the upper canopy (20-30 m) varied throughout the day and night, basal sap velocity (1.5 m) responded rapidly without an observable delay (< 15 min). Sap velocity showed a sigmoidal dependence on VPDs including an exponential increase, an inflection point, and a plateau, in all observed trees. Moreover, a clear diurnal hysteresis in sap velocity, stomatal conductance, and leaf water potential was evident with morning periods showing higher sensitivities to VPD than afternoon and night periods. Diurnal leaf gas exchange observations revealed a morning to midday peak in stomatal conductance, but midday to afternoon peak in transpiration and VPD. Thus, our study confirms that the temporal lag between the Gs peak and VPD peak are the major regulators of the hysteresis phenomenon as previously described by other studies. Moreover, out study provide direct evidence for the role of decreased stomatal conductance in the warm afternoon periods to reduce transpiration and allow for the partial recovery of leaf water potential to less negative values. Our results suggests the possibility of predicting evapotranspiration fluxes from ecosystem to regional scales using remote sensing of vegetation temperature from, for example, thermal images of satellites and drones.

  6. Radiation-use efficiency response to vapor pressure deficit for maize and sorghum

    International Nuclear Information System (INIS)

    Kiniry, J.R.; Landivar, J.A.; Witt, M.; Gerik, T.J.; Cavero, J.; Wade, L.J.

    1998-01-01

    Variability within a crop species in the amount of dry mass produced per unit intercepted solar radiation, or radiation-use efficiency (RUE), is important for the quantification of plant productivity. RUE has been used to integrate (1) leaf area, (2) solar radiation interception, and (3) productivity per unit leaf area into crop productivity. Responsiveness of RUE to vapor pressure deficit (VPD) should relate closely to responsiveness of CO 2 exchange rate (CER) to VPD. The objective of this study was to compare independent RUE measurements to published response functions relating VPD with RUE of maize (Zea mays L.) and grain sorghum [Sorghum bicolor L. (Moench)]. Data sets from five locations covering a wide range of mean VPD values were compared to published response functions. Predicted RUE values were nearly always within the 95% confidence intervals of measurements. Measured RUE of maize decreased as VPD increased from 0.9 to 1.7 kPa. For sorghum, measured values of RUE agreed closely with predictions. RUE of sorghum decreased as VPD increased from 1.1 to 2.2 kPa. The relative RUE:VPD responses for these two species were similar to CER:VPD responses reported in the literature. Thus, these RUE:VPD responses may be general and appear to be related to carbon exchange rates. We calculated the expected impacts of VPD on RUE at three USA locations during maize and sorghum growing seasons. The RUE:VPD equations offer hope in describing location effects and time-of-year effects on RUE. (author)

  7. Interactive response of photosynthetic characteristics in Haloxylon ammodendron and Hedysarum scoparium exposed to soil water and air vapor pressure deficits.

    Science.gov (United States)

    Gong, Chunmei; Wang, Jiajia; Hu, Congxia; Wang, Junhui; Ning, Pengbo; Bai, Juan

    2015-08-01

    C4 plants possess better drought tolerance than C3 plants. However, Hedysarum scoparium, a C3 species, is dominant and widely distributed in the desert areas of northwestern China due to its strong drought tolerance. This study compared it with Haloxylon ammodendron, a C4 species, regarding the interactive effects of drought stress and different leaf-air vapor pressure deficits. Variables of interest included gas exchange, the activity levels of key C4 photosynthetic enzymes, and cellular anatomy. In both species, gas exchange parameters were more sensitive to high vapor pressure deficit than to strong water stress, and the net CO2 assimilation rate (An) was enhanced as vapor pressure deficits increased. A close relationship between An and stomatal conductance (gs) suggested that the species shared a similar response mechanism. In H. ammodendron, the activity levels of key C4 enzymes were higher, including those of phosphoenolpyruvate carboxylase (PEPC) and nicotinamide adenine dinucleotide phosphate-malate enzyme (NADP-ME), whereas in H. scoparium, the activity level of nicotinamide adenine dinucleotide-malate enzyme (NAD-ME) was higher. Meanwhile, H. scoparium utilized adaptive structural features, including a larger relative vessel area and a shorter distance from vein to stomata, which facilitated the movement of water. These findings implied that some C4 biochemical pathways were present in H. scoparium to respond to environmental challenges. Copyright © 2015. Published by Elsevier B.V.

  8. Evaluation of Vapor Pressure and Ultra-High Vacuum Tribological Properties of Ionic Liquids (2) Mixtures and Additives

    Science.gov (United States)

    Morales, Wilfredo; Koch, Victor R.; Street, Kenneth W., Jr.; Richard, Ryan M.

    2008-01-01

    Ionic liquids are salts, many of which are typically viscous fluids at room temperature. The fluids are characterized by negligible vapor pressures under ambient conditions. These properties have led us to study the effectiveness of ionic liquids containing both organic cations and anions for use as space lubricants. In the previous paper we have measured the vapor pressure and some tribological properties of two distinct ionic liquids under simulated space conditions. In this paper we will present vapor pressure measurements for two new ionic liquids and friction coefficient data for boundary lubrication conditions in a spiral orbit tribometer using stainless steel tribocouples. In addition we present the first tribological data on mixed ionic liquids and an ionic liquid additive. Post mortem infrared and Raman analysis of the balls and races indicates the major degradation pathway for these two organic ionic liquids is similar to those of other carbon based lubricants, i.e. deterioration of the organic structure into amorphous graphitic carbon. The coefficients of friction and lifetimes of these lubricants are comparable to or exceed these properties for several commonly used space oils.

  9. Efficient absorption of SO{sub 2} with low-partial pressures by environmentally benign functional deep eutectic solvents

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Kai; Ren, Shuhang [State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029 (China); Hou, Yucui [Department of Chemistry, Taiyuan Normal University, Taiyuan, 030031 (China); Wu, Weize, E-mail: wzwu@mail.buct.edu.cn [State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029 (China)

    2017-02-15

    Graphical abstract: Environmentally benign deep eutectic solvents (DESs) based on betaine or L-carnitine with ethylene glycol were designed with a function and used to efficiently capture SO{sub 2} with low partial pressures. - Highlights: • Deep eutectic solvents (DESs) were designed with a function to absorb low-conc. SO{sub 2}. • Betaine(Bet) and L-carnitine(L-car) with a functional group were used as H-bond acceptor. • Bet + ethylene glycol (EG) DES and L-car + EG DES are environmentally benign. • L-car + EG DES can absorb 0.644 mol SO{sub 2} per mole L-car (0.37% SO{sub 2}). • L-car + EG DES is a promising absorbent for SO{sub 2} capture. - Abstract: Sulfur dioxide (SO{sub 2}) emitted from the burning of fossil fuels is one of the main air contaminants. In this work, we found that environmentally benign solvents, deep eutectic solvents (DESs) could be designed with a function to absorb low-partial pressure SO{sub 2} from simulated flue gas. Two kinds of biodegradable functional DESs based on betaine (Bet) and L-carnitine (L-car) as hydrogen bond accepters (HBA) and ethylene glycol (EG) as a hydrogen bond donor (HBD) were prepared with mole ratios of HBA to HBD from 1:3 to 1:5, and they were investigated to absorb SO{sub 2} with different partial pressures at various temperatures. The results showed that the two DESs could absorb low-partial pressure SO{sub 2} efficiently. SO{sub 2} absorption capacities of the DESs with HBA/HBD mole ratio of 1:3 were 0.332 mol SO{sub 2}/mol HBA for Bet + EG DES and 0.820 mol SO{sub 2}/mol HBA for L-car + EG DES at 40 °C with a SO{sub 2} partial pressure of 0.02 atm. In addition, the regeneration experiments demonstrated that the absorption capacities of DESs did not change after five absorption and desorption cycles. Furthermore, the absorption mechanism of SO{sub 2} by DESs was studied by FT-IR, {sup 1}H NMR and {sup 13}C NMR spectra. It was found that there are strong acid–base interactions between SO{sub 2} and

  10. Efficient absorption of SO_2 with low-partial pressures by environmentally benign functional deep eutectic solvents

    International Nuclear Information System (INIS)

    Zhang, Kai; Ren, Shuhang; Hou, Yucui; Wu, Weize

    2017-01-01

    Graphical abstract: Environmentally benign deep eutectic solvents (DESs) based on betaine or L-carnitine with ethylene glycol were designed with a function and used to efficiently capture SO_2 with low partial pressures. - Highlights: • Deep eutectic solvents (DESs) were designed with a function to absorb low-conc. SO_2. • Betaine(Bet) and L-carnitine(L-car) with a functional group were used as H-bond acceptor. • Bet + ethylene glycol (EG) DES and L-car + EG DES are environmentally benign. • L-car + EG DES can absorb 0.644 mol SO_2 per mole L-car (0.37% SO_2). • L-car + EG DES is a promising absorbent for SO_2 capture. - Abstract: Sulfur dioxide (SO_2) emitted from the burning of fossil fuels is one of the main air contaminants. In this work, we found that environmentally benign solvents, deep eutectic solvents (DESs) could be designed with a function to absorb low-partial pressure SO_2 from simulated flue gas. Two kinds of biodegradable functional DESs based on betaine (Bet) and L-carnitine (L-car) as hydrogen bond accepters (HBA) and ethylene glycol (EG) as a hydrogen bond donor (HBD) were prepared with mole ratios of HBA to HBD from 1:3 to 1:5, and they were investigated to absorb SO_2 with different partial pressures at various temperatures. The results showed that the two DESs could absorb low-partial pressure SO_2 efficiently. SO_2 absorption capacities of the DESs with HBA/HBD mole ratio of 1:3 were 0.332 mol SO_2/mol HBA for Bet + EG DES and 0.820 mol SO_2/mol HBA for L-car + EG DES at 40 °C with a SO_2 partial pressure of 0.02 atm. In addition, the regeneration experiments demonstrated that the absorption capacities of DESs did not change after five absorption and desorption cycles. Furthermore, the absorption mechanism of SO_2 by DESs was studied by FT-IR, "1H NMR and "1"3C NMR spectra. It was found that there are strong acid–base interactions between SO_2 and −COO"− on HBA.

  11. A high-throughput platform for low-volume high-temperature/pressure sealed vessel solvent extractions

    International Nuclear Information System (INIS)

    Damm, Markus; Kappe, C. Oliver

    2011-01-01

    Highlights: ► Parallel low-volume coffee extractions in sealed-vessel HPLC/GC vials. ► Extractions are performed at high temperatures and pressures (200 °C/20 bar). ► Rapid caffeine determination from the liquid phase. ► Headspace analysis of volatiles using solid-phase microextraction (SPME). - Abstract: A high-throughput platform for performing parallel solvent extractions in sealed HPLC/GC vials inside a microwave reactor is described. The system consist of a strongly microwave-absorbing silicon carbide plate with 20 cylindrical wells of appropriate dimensions to be fitted with standard HPLC/GC autosampler vials serving as extraction vessels. Due to the possibility of heating up to four heating platforms simultaneously (80 vials), efficient parallel analytical-scale solvent extractions can be performed using volumes of 0.5–1.5 mL at a maximum temperature/pressure limit of 200 °C/20 bar. Since the extraction and subsequent analysis by either gas chromatography or liquid chromatography coupled with mass detection (GC–MS or LC–MS) is performed directly from the autosampler vial, errors caused by sample transfer can be minimized. The platform was evaluated for the extraction and quantification of caffeine from commercial coffee powders assessing different solvent types, extraction temperatures and times. For example, 141 ± 11 μg caffeine (5 mg coffee powder) were extracted during a single extraction cycle using methanol as extraction solvent, whereas only 90 ± 11 were obtained performing the extraction in methylene chloride, applying the same reaction conditions (90 °C, 10 min). In multiple extraction experiments a total of ∼150 μg caffeine was extracted from 5 mg commercial coffee powder. In addition to the quantitative caffeine determination, a comparative qualitative analysis of the liquid phase coffee extracts and the headspace volatiles was performed, placing special emphasis on headspace analysis using solid-phase microextraction (SPME

  12. A high-throughput platform for low-volume high-temperature/pressure sealed vessel solvent extractions

    Energy Technology Data Exchange (ETDEWEB)

    Damm, Markus [Christian Doppler Laboratory for Microwave Chemistry (CDLMC) and Institute of Chemistry, Karl-Franzens-University Graz, Heinrichstrasse 28, A-8010 Graz (Austria); Kappe, C. Oliver, E-mail: oliver.kappe@uni-graz.at [Christian Doppler Laboratory for Microwave Chemistry (CDLMC) and Institute of Chemistry, Karl-Franzens-University Graz, Heinrichstrasse 28, A-8010 Graz (Austria)

    2011-11-30

    Highlights: Black-Right-Pointing-Pointer Parallel low-volume coffee extractions in sealed-vessel HPLC/GC vials. Black-Right-Pointing-Pointer Extractions are performed at high temperatures and pressures (200 Degree-Sign C/20 bar). Black-Right-Pointing-Pointer Rapid caffeine determination from the liquid phase. Black-Right-Pointing-Pointer Headspace analysis of volatiles using solid-phase microextraction (SPME). - Abstract: A high-throughput platform for performing parallel solvent extractions in sealed HPLC/GC vials inside a microwave reactor is described. The system consist of a strongly microwave-absorbing silicon carbide plate with 20 cylindrical wells of appropriate dimensions to be fitted with standard HPLC/GC autosampler vials serving as extraction vessels. Due to the possibility of heating up to four heating platforms simultaneously (80 vials), efficient parallel analytical-scale solvent extractions can be performed using volumes of 0.5-1.5 mL at a maximum temperature/pressure limit of 200 Degree-Sign C/20 bar. Since the extraction and subsequent analysis by either gas chromatography or liquid chromatography coupled with mass detection (GC-MS or LC-MS) is performed directly from the autosampler vial, errors caused by sample transfer can be minimized. The platform was evaluated for the extraction and quantification of caffeine from commercial coffee powders assessing different solvent types, extraction temperatures and times. For example, 141 {+-} 11 {mu}g caffeine (5 mg coffee powder) were extracted during a single extraction cycle using methanol as extraction solvent, whereas only 90 {+-} 11 were obtained performing the extraction in methylene chloride, applying the same reaction conditions (90 Degree-Sign C, 10 min). In multiple extraction experiments a total of {approx}150 {mu}g caffeine was extracted from 5 mg commercial coffee powder. In addition to the quantitative caffeine determination, a comparative qualitative analysis of the liquid phase coffee

  13. Vapor pressures of (3-(Dimethylamino)propyl)dimethylindium, (tert-Butylimino)bis(diethylamino)cyclopentadienyltantalum, and (tert-Butylimino)tris(ethylmethylamino)tantalum

    Czech Academy of Sciences Publication Activity Database

    Morávek, Pavel; Pangrác, Jiří; Fulem, Michal; Hulicius, Eduard; Růžička, K.

    2014-01-01

    Roč. 59, č. 12 (2014), s. 4179-4183 ISSN 0021-9568 Institutional support: RVO:68378271 Keywords : vapor pressure * static method * organometallics Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.037, year: 2014

  14. Reid Vapor Pressure (RVP) of Gasoline Spreadsheet Example Key for Requirements at 40 CFR 80.47(g) and 80.47(l)

    Science.gov (United States)

    This guidance deals with the self-qualification of analytical test methods at a testing facility for measuring Reid Vapor Pressure (RVP) of gasoline to meet precision requirements codified in regulations.

  15. [Analysis of saponins from panax notoginseng using pressurized solvent extraction coupled with liquid chromatography-electrospray mass spectrum].

    Science.gov (United States)

    Wan, Jianbo; Li, Changming; Li, Shaopin; Kong, Lingyi; Wang, Yitao

    2005-10-01

    To establish a method for qualitative analysis of saponins from Panax notoginseng using pressurized solvent extraction coupled with LC-ESI-MS. The PSE technology was applied to the process of extraction for Panax notoginseng, and the negative ion detection and multiple reaction monitoring model were used. The saponins were investigated based on total ion chromatogram (TIC) and MRM chromatogram. According to the fragment character of saponins, the molecular weight and their structures could be identified. The method can be used for qualitative analysis of saponins from Panax notoginseng.

  16. Water vapor pressure over molten KH2PO4 and demonstration of water electrolysis at ∼300ºC

    DEFF Research Database (Denmark)

    Berg, Rolf W.; Nikiforov, Aleksey Valerievich; Petrushina, Irina

    2016-01-01

    A new potentially high-efficiency electrolyte for water electrolysis: molten monobasic potassium phosphate, KH2PO4 or KDP has been investigated at temperatures ∼275–325 °C. At these temperatures, KH2PO4 was found to dissociate into H2O gas in equilibrium with a melt mixture of KH2PO4—K2H2P2O7—KPO3...... of water and methane or hydrogen to be 0.40 ± 0.02 or 1.2 ± 0.03. At equilibrium the vapor pressure was much lower than the vapor pressure above liquid water at the same temperature. Electrolysis was realized by passing current through closed ampoules (vacuum sealed quartz glass electrolysis cells...... with platinum electrodes and the electrolyte melt). The formation of mixtures of hydrogen and oxygen gases as well as the water vapor was detected by Raman spectroscopy. In this way it was demonstrated that water is present in the new electrolyte: molten KH2PO4 can be split by electrolysis via the reaction 2H2O...

  17. Development of copper recovery process from flotation tailings by a combined method of high‒pressure leaching‒solvent extraction.

    Science.gov (United States)

    Han, Baisui; Altansukh, Batnasan; Haga, Kazutoshi; Stevanović, Zoran; Jonović, Radojka; Avramović, Ljiljana; Urosević, Daniela; Takasaki, Yasushi; Masuda, Nobuyuki; Ishiyama, Daizo; Shibayama, Atsushi

    2018-06-15

    Sulfide copper mineral, typically Chalcopyrite (CuFeS 2 ), is one of the most common minerals for producing metallic copper via the pyrometallurgical process. Generally, flotation tailings are produced as a byproduct of flotation and still consist of un‒recovered copper. In addition, it is expected that more tailings will be produced in the coming years due to the increased exploration of low‒grade copper ores. Therefore, this research aims to develop a copper recovery process from flotation tailings using high‒pressure leaching (HPL) followed by solvent extraction. Over 94.4% copper was dissolved from the sample (CuFeS 2 as main copper mineral) by HPL in a H 2 O media in the presence of pyrite, whereas the iron was co‒dissolved with copper according to an equation given as C Cu  = 38.40 × C Fe . To avoid co‒dissolved iron giving a negative effect on the subsequent process of electrowinning, solvent extraction was conducted on the pregnant leach solution for improving copper concentration. The result showed that 91.3% copper was recovered in a stripped solution and 98.6% iron was removed under the optimal extraction conditions. As a result, 86.2% of copper was recovered from the concentrate of flotation tailings by a proposed HPL‒solvent extraction process. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Vapor-Liquid Phase Equilibria for Carbon Dioxide-I- Isopentanol Binary System at Elevated Pressure%Vapor-Liquid Phase Equilibria for Carbon Dioxide-I- Isopentanol Binary System at Elevated Pressure

    Institute of Scientific and Technical Information of China (English)

    王琳; 曹丰璞; 刘珊珊; 杨浩

    2011-01-01

    High-pressure vapor-liquid phase equilibrium data for carbon dioxide+ isopentanol were measured at tempera- tures of 313.2, 323.1, 333.5 and 343.4 K in the pressure range of 4.64 to 12.71 MPa in a variable-volume high-pressure visual cell. The experimental data were well correlated with Peng-Robinson equation of state (PR-EOS) together with van der Waals-2 two-parameter mixing rule, and the binary interaction parameters were obtained. Henry coefficients and partial molar volumes of CO2 at infinite dilution were estimated based on Krichevsky-Kasarnovsky equation, and Henry coefficients increase with increasing temperature, however, partial molar volumes of CO2 at infinite dilution are negative and the magnitudes decrease with temperature.

  19. Where do winds come from? A new theory on how water vapor condensation influences atmospheric pressure and dynamics

    Science.gov (United States)

    Makarieva, A. M.; Gorshkov, V. G.; Sheil, D.; Nobre, A. D.; Li, B.-L.

    2013-01-01

    Phase transitions of atmospheric water play a ubiquitous role in the Earth's climate system, but their direct impact on atmospheric dynamics has escaped wide attention. Here we examine and advance a theory as to how condensation influences atmospheric pressure through the mass removal of water from the gas phase with a simultaneous account of the latent heat release. Building from fundamental physical principles we show that condensation is associated with a decline in air pressure in the lower atmosphere. This decline occurs up to a certain height, which ranges from 3 to 4 km for surface temperatures from 10 to 30 °C. We then estimate the horizontal pressure differences associated with water vapor condensation and find that these are comparable in magnitude with the pressure differences driving observed circulation patterns. The water vapor delivered to the atmosphere via evaporation represents a store of potential energy available to accelerate air and thus drive winds. Our estimates suggest that the global mean power at which this potential energy is released by condensation is around one per cent of the global solar power - this is similar to the known stationary dissipative power of general atmospheric circulation. We conclude that condensation and evaporation merit attention as major, if previously overlooked, factors in driving atmospheric dynamics.

  20. A study of vapor bubble departure in subcooled flow boiling at low pressure

    International Nuclear Information System (INIS)

    Donevski, Bozin; Saga, Tetsuo; Kobayashi, Toshio; Segawa, Shigeki

    1999-01-01

    An experimental study of vapor bubble dynamics in sub-cooled flow boiling was conducted using the flow visualization and digital image processing methods. Vapor bubble departure departure in subcooled flow boiling have been experimentally investigated over a range of mass flux G=0.384 (kg/m 2 s), and heat flux q w = 27.2 x 10 4 (W/m 2 ), for the subcooled flow boiling region. It has been observed that once a vapor bubble departs from a nucleation site, it typically slides along the heating surface at sonic finite distance down-stream of nucleation site. The image processing method proposed in this study is based on the detachment and tracing of the edges of the bubbles and their background. The proposed method can be used in various fields of engineering applications. (Original)

  1. Highly Efficient 2D/3D Hybrid Perovskite Solar Cells via Low-Pressure Vapor-Assisted Solution Process.

    Science.gov (United States)

    Li, Ming-Hsien; Yeh, Hung-Hsiang; Chiang, Yu-Hsien; Jeng, U-Ser; Su, Chun-Jen; Shiu, Hung-Wei; Hsu, Yao-Jane; Kosugi, Nobuhiro; Ohigashi, Takuji; Chen, Yu-An; Shen, Po-Shen; Chen, Peter; Guo, Tzung-Fang

    2018-06-08

    The fabrication of multidimensional organometallic halide perovskite via a low-pressure vapor-assisted solution process is demonstrated for the first time. Phenyl ethyl-ammonium iodide (PEAI)-doped lead iodide (PbI 2 ) is first spin-coated onto the substrate and subsequently reacts with methyl-ammonium iodide (MAI) vapor in a low-pressure heating oven. The doping ratio of PEAI in MAI-vapor-treated perovskite has significant impact on the crystalline structure, surface morphology, grain size, UV-vis absorption and photoluminescence spectra, and the resultant device performance. Multiple photoluminescence spectra are observed in the perovskite film starting with high PEAI/PbI 2 ratio, which suggests the coexistence of low-dimensional perovskite (PEA 2 MA n -1 Pb n I 3 n +1 ) with various values of n after vapor reaction. The dimensionality of the as-fabricated perovskite film reveals an evolution from 2D, hybrid 2D/3D to 3D structure when the doping level of PEAI/PbI 2 ratio varies from 2 to 0. Scanning electron microscopy images and Kelvin probe force microscopy mapping show that the PEAI-containing perovskite grain is presumably formed around the MAPbI 3 perovskite grain to benefit MAPbI 3 grain growth. The device employing perovskite with PEAI/PbI 2 = 0.05 achieves a champion power conversion efficiency of 19.10% with an open-circuit voltage of 1.08 V, a current density of 21.91 mA cm -2 , and a remarkable fill factor of 80.36%. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Vapor pressure data for ethyl-2-methylbutyrate, hexanal and (E)-2-hexenal at a pressure range of (25 to 190) kPa

    International Nuclear Information System (INIS)

    Meneses, David A.; Bejarano, Arturo; Fuente, Juan C. de la

    2014-01-01

    Highlights: • Vapor pressures of three pure apple aroma constituents were measured. • Measurements were made over the temperature range of (362.1 to 429.9) K. • Constants of Antoine and Wagner type equations were fitted to the experimental data. • Relative deviations (rmsd) from the three vapor-pressure equations were <0.9%. • Contrast with literature showed discrepancies <9% among them and with this work. - Abstract: The saturated vapor pressures of pure ethyl-2-methylbutyrate, hexanal and (E)-2-hexenal, which are volatile compounds characteristic of apple aroma, were measured with a dynamic recirculation apparatus at a pressure range of (24.5 to 190.0) kPa. Measurements were made over the temperature range of (362.1 to 429.9) K for ethyl-2-methylbutyrate, (358.1 to 425.8) K for hexanal, and (373.5 to 446.2) K for (E)-2-hexenal. The maximum likelihood method was used to estimate the parameters of the Antoine equation, whereas the parameters of an extended Antoine equation and the Wagner equation were determined by non linear least square method. The three models showed root mean square deviations (rmsd) of 0.29%, 0.28%, and 0.27% for ethyl-2-methylbutyrate, 0.58%, 0.48%, and 0.38% for hexanal, and 0.89%, 0.62% and 0.36% for (E)-2-hexenal, respectively. Additionally, the experimental data and correlation were compared with those available in the literature

  3. The functional dependence of canopy conductance on water vapor pressure deficit revisited

    NARCIS (Netherlands)

    Fuchs, Marcel; Stanghellini, Cecilia

    2018-01-01

    Current research seeking to relate between ambient water vapor deficit (D) and foliage conductance (gF) derives a canopy conductance (gW) from measured transpiration by inverting the coupled transpiration model to yield gW = m − n ln(D) where m and n are fitting parameters. In contrast, this paper

  4. Studies on micro-structures at vapor-liquid interfaces of film boiling on hot liquid surface at arriving of a shock pressure

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Akira; Lee, S. [Tokyo Inst. of Tech. (Japan)

    1998-01-01

    In vapor explosions, a pressure wave (shock wave) plays a fundamental role in the generation, propagation and escalation of the explosion. Transient volume change by rapid heat flow from a high temperature liquid to a low temperature volatile one and phase change generate micro-scale flow and the pressure wave. One of key issues for the vapor explosion is to make clear the mechanism to support the explosive energy release from hot drop to cold liquid. According to our observations by an Image Converter Camera, growth rate of vapor film around a hot tin drop became several times higher than that around a hot Platinum tube at the same conditions when a pressure pulse collapsed the film. The thermally induced fragmentation was followed by the explosive growth rate of the hot drop. In the previous report, we have proposed that the interface instability and fragmentation model in which the fine Taylor instability of vapor-liquid interface at the collapsing and re-growth phase of vapor film and the instability induced by the high pressure spots at the drop surface were assumed. In this study, the behavior of the vapor-liquid interface region at arrival of a pressure pulse was investigated by the CIPRIS code which is able to simulate dynamics of transient multi-phase interface regions. It is compared with the observation results. Through detailed investigations of these results, the mechanisms of the thermal fragmentation of single drop are discussed. (J.P.N.)

  5. Oxygen source-oriented control of atmospheric pressure chemical vapor deposition of VO2 for capacitive applications

    Directory of Open Access Journals (Sweden)

    Dimitra Vernardou

    2016-06-01

    Full Text Available Vanadium dioxides of different crystalline orientation planes have successfully been fabricated by chemical vapor deposition at atmospheric pressure using propanol, ethanol and O2 gas as oxygen sources. The thick a-axis textured monoclinic vanadium dioxide obtained through propanol presented the best electrochemical response in terms of the highest specific discharge capacity of 459 mAh g-1 with a capacitance retention of 97 % after 1000 scans under constant specific current of 2 A g-1. Finally, the electrochemical impedance spectroscopy indicated that the charge transfer of Li+ through the vanadium dioxide / electrolyte interface was easier for this sample enhancing significantly its capacitance performance.

  6. Beer Law Constants and Vapor Pressures of HgI2 over HgI2(s,l)

    Science.gov (United States)

    Su, Ching-Hua; Zhu, Shen; Ramachandran, N.; Burger, A.

    2002-01-01

    Optical absorption spectra of the vapor phase over HgI2(s,l) were measured at sample temperatures between 349 and 610 K for wavelengths between 200 and 600 nm. The spectra show the samples sublimed congruently into HGI2 without any observed Hg or I2 absorption spectra. The Beer's Law constants for 15 wavelengths between 200 and 440 nm were derived. From these constants the vapor pressure of HgI2, P, was found to be a function of temperature for the liquid and the solid beta-phases: ln P(atm) = -7700/T(K) + 12.462 (liquid phase) and ln P(atm) = -10150/T(K) + 17.026 (beta-phase). The expressions match 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.

  7. Atmospheric pressure chemical vapor deposition (APCVD) grown bi-layer graphene transistor characteristics at high temperature

    KAUST Repository

    Qaisi, Ramy M.

    2014-05-15

    We report the characteristics of atmospheric chemical vapor deposition grown bilayer graphene transistors fabricated on ultra-scaled (10 nm) high-κ dielectric aluminum oxide (Al2O3) at elevated temperatures. We observed that the drive current increased by >400% as temperature increased from room temperature to 250 °C. Low gate leakage was maintained for prolonged exposure at 100 °C but increased significantly at temperatures >200 °C. These results provide important insights for considering chemical vapor deposition graphene on aluminum oxide for high temperature applications where low power and high frequency operation are required. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Atmospheric pressure chemical vapor deposition (APCVD) grown bi-layer graphene transistor characteristics at high temperature

    KAUST Repository

    Qaisi, Ramy M.; Smith, Casey; Hussain, Muhammad Mustafa

    2014-01-01

    We report the characteristics of atmospheric chemical vapor deposition grown bilayer graphene transistors fabricated on ultra-scaled (10 nm) high-κ dielectric aluminum oxide (Al2O3) at elevated temperatures. We observed that the drive current increased by >400% as temperature increased from room temperature to 250 °C. Low gate leakage was maintained for prolonged exposure at 100 °C but increased significantly at temperatures >200 °C. These results provide important insights for considering chemical vapor deposition graphene on aluminum oxide for high temperature applications where low power and high frequency operation are required. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Determination of Water Vapor Pressure Over Corrosive Chemicals Versus Temperature Using Raman Spectroscopy as Exemplified with 85.5% Phosphoric Acid

    DEFF Research Database (Denmark)

    Rodier, Marion; Li, Qingfeng; Berg, Rolf W.

    2016-01-01

    A method to determine the water vapor pressure over a corrosive substance was developed and tested with 85.5 ± 0.4% phosphoric acid. The water vapor pressure was obtained at a range of temperatures from ∼25 ℃ to ∼200 ℃ using Raman spectrometry. The acid was placed in an ampoule and sealed...... with a reference gas (either hydrogen or methane) at a known pressure (typically ∼0.5 bar). By comparing the Raman signals from the water vapor and the references, the water pressure was determined as a function of temperature. A considerable amount of data on the vapor pressure of phosphoric acid are available...... in the literature, to which our results could successfully be compared. A record value of the vapor pressure, 3.40 bar, was determined at 210 ℃. The method required a determination of the precise Raman scattering ratios between the substance, water, and the used reference gas, hydrogen or methane. In our case...

  10. Vapor pressures and standard molar enthalpies, entropies and Gibbs energies of sublimation of two hexachloro herbicides using a TG unit

    International Nuclear Information System (INIS)

    Vecchio, Stefano

    2010-01-01

    The vapor pressures above the solid hexachlorobenzene (HCB) and above both the solid and liquid 1,2,3,4,5,6-hexachlorocyclohexane (lindane) were determined in the ranges 332-450 K and 347-429 K, respectively, by measuring the mass loss rates recorded by thermogravimetry under both isothermal and nonisothermal conditions. The results obtained were compared with those taken from literature. From the temperature dependence of vapor pressure derived by the experimental thermogravimetry data the molar enthalpies of sublimation Δ cr g H m o ( ) were selected for HCB and lindane as well as the molar enthalpy of vaporization Δ l g H m o ( ) for lindane only, at the middle of the respective temperature intervals. The melting temperatures and the molar enthalpies of fusion Δ cr l H m o (T fus ) of lindane were measured by differential scanning calorimetry. Finally, the standard molar enthalpies of sublimation Δ cr g H m o (298.15 K) were obtained for both chlorinated compounds at the reference temperature of 298.15 K using the Δ cr g H m o ( ), Δ l g H m o ( ) and Δ cr l H m o (T fus ) values, as well as the heat capacity differences between gas and liquid and the heat capacity differences between gas and solid, Δ l g C p,m o and Δ cr g C p,m o , respectively, both estimated by applying a group additivity procedure. Therefore, the averages of the standard (p o = 0.1 MPa) molar enthalpies, entropies and Gibbs energies of sublimation at 298.15 K, have been derived.

  11. Evaluation of corrosion behaviour of tantalum coating obtained by low pressure chemical vapor deposition using electrochemical polarization

    Science.gov (United States)

    Levesque, A.; Bouteville, A.; de Baynast, H.; Laveissière, B.

    2002-06-01

    antalum coatings are elaborated on titanium substrates through Low Pressure Chemical Vapor Deposition from tantalum pentachloride-hydrogen gaseous phase at a deposition temperature of 800 °C and a total pressure of 3.3 mbar. The aim of this paper is to evaluate the effectiveness of this tantalum coating in corrosive solution. Optical Microscopy and Scanning Electron Microscopy observations reveal that deposits are of 1.7 μm in thickness and conformal. The corrosion resistance of tantalum coated titanium substrates is quantified through standard potentiodynamic polarization method. Even for tantalum coatings exhibiting some defects as pores, the corrosion current density is as low as 0.25 mA/cm^2.in very agressive solutions like kroll reagent (HN03/HF).

  12. Isosteric Vapor Pressure – Temperature Data for Water Sorption in Hardened Cement Paste: Enthalpy, Entropy and Sorption Isotherms at Different Temperatures

    DEFF Research Database (Denmark)

    Radjy, Fariborz; Sellevold, Erik J.; Hansen, Kurt Kielsgaard

    . The accuracies for pressure, enthalpy and entropy are found to be 0.5% or less. PART II: The TPA-system has been used to generate water vapor pressure – temperature data for room temperature – and steam cured hardened cement pastes as well as porous vycor glass. The moisture contents range from saturated to dry...... and the temperatures range from 2 to 95 °C, differing for the specimen types. The data has been analyzed to yield differential enthalpy and entropy of adsorption, as well as the dependence of the relative vapor pressure on temperature at various constant moisture contents. The implications for the coefficient......PART I: In order to generate isosteric (constant mass) vapor pressure – temperature data (P-T data) for adsorbed pore water in hydrated cement paste, the Thermo Piestic Analysis system (the TPA system) described herein was developed. The TPA system generates high precision equilibrium isosteric P...

  13. In-situ epitaxial growth of heavily phosphorus doped SiGe by low pressure chemical vapor deposition

    CERN Document Server

    Lee, C J

    1998-01-01

    We have studied epitaxial crystal growth of Si sub 1 sub - sub x Ge sub x films on silicon substrates at 550 .deg. C by low pressure chemical vapor deposition. In a low PH sub 3 partial pressure region such as below 1.25x10 sup - sup 3 Pa, both the phosphorus and carrier concentrations increased with increasing PH sub 3 partial pressure, but the deposition rate and the Ge fraction remained constant. In a higher PH sub 3 partial pressure region, the deposition rate, the phosphorus concentration, and the carrier concentration decreased, while the Ge fraction increased. These suggest that high surface coverage of phosphorus suppresses both SiH sub 4 and GeH sub 4 adsorption/reactions on the surfaces, and its suppression effect on SiH sub 4 is actually much stronger than on GeH sub 4. In particular, epitaxial crystal growth is largely controlled by surface coverage effect of phosphorus in a higher PH sub 3 partial pressure region.

  14. Experimental measurement of vapor pressures and (vapor + liquid) equilibrium for {1,1,1,2-tetrafluoroethane (R134a) + propane (R290)} by a recirculation apparatus with view windows

    International Nuclear Information System (INIS)

    Dong Xueqiang; Gong Maoqiong; Liu Junsheng; Wu Jianfeng

    2011-01-01

    The saturated vapor pressures of 1,1,1,2-tetrafluoroethane (R134a) and propane (R290), and the (vapor + liquid) equilibrium (VLE) data at (255.000, 265.000, 275.000, and 285.000) K for the (R134a + R290) system were measured by a recirculation apparatus with view windows. The uncertainty of the temperatures, pressures, and compositions are less than ±5 mK, ±0.0005 MPa, and ±0.005, respectively. The saturated vapor pressures data were correlated by a Wagner type equation and compared with the reference data. The binary VLE data were correlated with the Peng-Robinson equation of state (PR EoS) incorporating the Huron-Vidal (HV) mixing rule utilizing the nonrandom two-liquid (NRTL) activity coefficient model. For mixtures, the maximum average absolute relative deviation of pressure is 0.15%, while the maximum average absolute deviation of vapor phase mole fraction is 0.0045. Azeotropic behavior can be found for the (R134a + R290) system at measured temperatures.

  15. Experimental measurement of vapor pressures and (vapor + liquid) equilibrium for {l_brace}1,1,1,2-tetrafluoroethane (R134a) + propane (R290){r_brace} by a recirculation apparatus with view windows

    Energy Technology Data Exchange (ETDEWEB)

    Dong Xueqiang [Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, P.O. Box 2711, Beijing 100190 (China); Graduate University of Chinese Academy of Sciences, Beijing 100039 (China); Gong Maoqiong, E-mail: gongmq@mail.ipc.ac.c [Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, P.O. Box 2711, Beijing 100190 (China); Liu Junsheng [Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, P.O. Box 2711, Beijing 100190 (China); Graduate University of Chinese Academy of Sciences, Beijing 100039 (China); Wu Jianfeng, E-mail: jfwu@mail.ipc.ac.c [Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, P.O. Box 2711, Beijing 100190 (China)

    2011-03-15

    The saturated vapor pressures of 1,1,1,2-tetrafluoroethane (R134a) and propane (R290), and the (vapor + liquid) equilibrium (VLE) data at (255.000, 265.000, 275.000, and 285.000) K for the (R134a + R290) system were measured by a recirculation apparatus with view windows. The uncertainty of the temperatures, pressures, and compositions are less than {+-}5 mK, {+-}0.0005 MPa, and {+-}0.005, respectively. The saturated vapor pressures data were correlated by a Wagner type equation and compared with the reference data. The binary VLE data were correlated with the Peng-Robinson equation of state (PR EoS) incorporating the Huron-Vidal (HV) mixing rule utilizing the nonrandom two-liquid (NRTL) activity coefficient model. For mixtures, the maximum average absolute relative deviation of pressure is 0.15%, while the maximum average absolute deviation of vapor phase mole fraction is 0.0045. Azeotropic behavior can be found for the (R134a + R290) system at measured temperatures.

  16. Chemical vapor deposition of hexagonal boron nitride films in the reduced pressure

    International Nuclear Information System (INIS)

    Choi, B.J.

    1999-01-01

    Hexagonal boron nitride (h-BN) films were deposited onto a graphite substrate in reduced pressure by reacting ammonia and boron tribromide at 800--1,200 C. The growth rate of h-BN films was dependent on the substrate temperature and the total pressures. The growth rate increased with increasing the substrate temperature at the pressure of 2 kPa, while it showed a maximum value at the pressures of 4 and 8 kPa. The temperature at which the maximum growth rate occurs decreased with increasing total pressure. With increasing the substrate temperature and total pressure, the apparent grain size increased and the surface morphology showed a rough, cauliflower-like structure

  17. Time variant layer control in atmospheric pressure chemical vapor deposition based growth of graphene

    KAUST Repository

    Qaisi, Ramy M.; Smith, Casey; Hussain, Muhammad Mustafa

    2013-01-01

    Graphene is a semi-metallic, transparent, atomic crystal structure material which is promising for its high mobility, strength and transparency - potentially applicable for radio frequency (RF) circuitry and energy harvesting and storage applications. Uniform (same number of layers), continuous (not torn or discontinuous), large area (100 mm to 200 mm wafer scale), low-cost, reliable growth are the first hand challenges for its commercialization prospect. We show a time variant uniform (layer control) growth of bi- to multi-layer graphene using atmospheric chemical vapor deposition system. We use Raman spectroscopy for physical characterization supported by electrical property analysis. © 2013 IEEE.

  18. Time variant layer control in atmospheric pressure chemical vapor deposition based growth of graphene

    KAUST Repository

    Qaisi, Ramy M.

    2013-04-01

    Graphene is a semi-metallic, transparent, atomic crystal structure material which is promising for its high mobility, strength and transparency - potentially applicable for radio frequency (RF) circuitry and energy harvesting and storage applications. Uniform (same number of layers), continuous (not torn or discontinuous), large area (100 mm to 200 mm wafer scale), low-cost, reliable growth are the first hand challenges for its commercialization prospect. We show a time variant uniform (layer control) growth of bi- to multi-layer graphene using atmospheric chemical vapor deposition system. We use Raman spectroscopy for physical characterization supported by electrical property analysis. © 2013 IEEE.

  19. High Pressure Vapor-Liquid Equilibrium of Supercritical Carbon Dioxide + n-Hexane System

    Institute of Scientific and Technical Information of China (English)

    YU Jinglin; TIAN Yiling; ZHU Rongjiao; LIU Zhihua

    2006-01-01

    Vapor-liquid equilibrium data of supercritical carbon dioxide + n-hexane system were measured at 313.15 K,333.15 K,353.15 K,and 373.15 K and their molar volumes and densities were measured both in the subcritical and supercritical regions ranging from 2.15 to 12.63 MPa using a variable-volume autoclave.The thermodynamic properties including mole fractions,densities,and molar volumes of the system were calculated with an equation of state by Heilig and Franck,in which a repulsion term and a square-well potential attraction term for intermolecular interaction was used.The pairwise combination rule was used to calculate the square-well molecular interaction potential and three adjustable parameters (ω,kε,kσ) were obtained.The Heilig-Franck equation of state is found to have good correlation with binary vapor-liquid equilibrium data of the carbon dioxide + n-hexane system.

  20. Synthesis and investigation of saturated vapor pressure of lanthanum, praseodymium and neodymium tris-isopropylcyclopentadienyls

    International Nuclear Information System (INIS)

    Devyatykh, G.G.; Chernyaev, N.P.; Zverev, Yu.B.; Gavrishchuk, E.M.; Runovskaya, I.V.; Krupnova, Eh.F.; Chesnokova, S.G.

    1980-01-01

    Lanthanum, praseodymium and neodymium tris-isopropylcyclopentadienyls are synthesized with corresponding unhydrous chlorides in tetrahydrofuran solution. Saturated vapour pressure of substances obtained is studied in the 150-262 deg C range by the statistic method using a compensation zero-manometer. Vapour pressure of the compounds in question is shown to increase with the growth of the rare earth element number [ru

  1. Steam and solvent injection as an advanced recovering method for heavy oil reservoirs; Injecao de vapor e solvente como um metodo de recuperacao avancada em reservatorios de oleo pesado

    Energy Technology Data Exchange (ETDEWEB)

    Galvao, Edney Rafael V.P.; Rodrigues, Marcos Allyson F.; Barbosa, Janaina Medeiros D.; Barillas, Jennys Lourdes M.; Dutra Junior, Tarcilio V.; Mata, Wilson da [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2008-07-01

    Currently a resource more and more used by the petroleum industry to increase the efficiency of steam flood mechanism is the addition of solvents. The process can be understood as a combination of a thermal method (steam injection) with a miscible method (solvent injection), promoting, thus, the reduction of interfacial tensions and oil viscosity. The mobility of the displaced fluid is then improved, resulting in an increase of oil recovery. To better understand this improved oil recovery method, a numerical study of the process was driven contemplating the effects of some operational parameters (distance between wells, injection fluids rate, kind of solvent and injected solvent volume) on the accumulated production of oil and recovery factor. Semisynthetic models were used in this study but reservoir data can be extrapolated for practical applications situations on Potiguar Basin. Simulations were performed in STARS (CMG, 2007.11). It was found that injected solvent volumes increased oil recovery and oil rates. Further the majority of the injected solvent was produced and can be recycled. (author)

  2. Mass Spectrometric Identification of Si-O-H(g) Species from the Reaction of Silica with Water Vapor at Atmospheric Pressure

    Science.gov (United States)

    Opila, Elizabeth J.; Fox, Dennis S.; Jacobson, Nathan S.

    1997-01-01

    A high-pressure sampling mass spectrometer was used to detect the volatile species formed from SiO2 at temperatures between 1200C and 1400C in a flowing water vapor/oxygen gas mixture at 1 bar total pressure. The primary vapor species identified was Si(OH)4. The fragment ion Si(OH)3+,' was observed in quantities 3 to 5 times larger than the parent ion Si(OH)4+. The Si(OH)3+ intensity was found to have a small temperature dependence and to increase with the water vapor partial pressure as expected. In addition, SiO(OH)+ believed to be a fragment of SiO(OH)2, was observed. These mass spectral results were compared to the behavior of silicon halides.

  3. Experimental determination of cesium saturated vapor pressure in the 483/642 deg K temperature

    Energy Technology Data Exchange (ETDEWEB)

    Gushchin, G I; Subbotin, V A; Khachaturov, Eh Kh [Gosudarstvennyj Komitet po Ispol' zovaniyu Atomnoj Ehnergii SSSR, Obninsk. Fiziko-Ehnergeticheskij Inst.

    1975-07-01

    Test results of saturated cesium vapour pressure in the temperature range of 483.13-642 deg K and pressure range of 15.77-1.389 N/m/sup 2/ by direct static method are presented. The testing system comprises a differential bellows-type pressure sensor, a thermostatic unit and a gas system with V-shaped oil manometer used for argon-assisted sensor calibration. The static sensor characteristic approaches linearity in the pressure range of 10-600 N/m/sup 2/. The greatest non-linearity is observed at low pressures (10-40 N/m/sup 2/) and does not exceed 3-4%. Sensor sensitivity is 0.39 mV/N/m/sup 2/ in this pressure range. The characteristic hysteresis is 0.5% and below. With pressures greater than 600 N/m/sup 2/, the sensor sensitivity gradually decreases by 12% while the characteristic hysteresis increases to 2-3%. A brief description of the experimental procedure is offered. The present results are compared with other authors' data.

  4. Reduced-Pressure Chemical Vapor Deposition Growth of Isolated Ge Crystals and Suspended Layers on Micrometric Si Pillars.

    Science.gov (United States)

    Skibitzki, Oliver; Capellini, Giovanni; Yamamoto, Yuji; Zaumseil, Peter; Schubert, Markus Andreas; Schroeder, Thomas; Ballabio, Andrea; Bergamaschini, Roberto; Salvalaglio, Marco; Miglio, Leo; Montalenti, Francesco

    2016-10-05

    In this work, we demonstrate the growth of Ge crystals and suspended continuous layers on Si(001) substrates deeply patterned in high aspect-ratio pillars. The material deposition was carried out in a commercial reduced-pressure chemical vapor deposition reactor, thus extending the "vertical-heteroepitaxy" technique developed by using the peculiar low-energy plasma-enhanced chemical vapor deposition reactor, to widely available epitaxial tools. The growth process was thoroughly analyzed, from the formation of small initial seeds to the final coalescence into a continuous suspended layer, by means of scanning and transmission electron microscopy, X-ray diffraction, and μ-Raman spectroscopy. The preoxidation of the Si pillar sidewalls and the addition of hydrochloric gas in the reactants proved to be key to achieve highly selective Ge growth on the pillars top only, which, in turn, is needed to promote the formation of a continuous Ge layer. Thanks to continuum growth models, we were able to single out the different roles played by thermodynamics and kinetics in the deposition dynamics. We believe that our findings will open the way to the low-cost realization of tens of micrometers thick heteroepitaxial layer (e.g., Ge, SiC, and GaAs) on Si having high crystal quality.

  5. Identification of Alternative Vapor Intrusion Pathways Using Controlled Pressure Testing, Soil Gas Monitoring, and Screening Model Calculations.

    Science.gov (United States)

    Guo, Yuanming; Holton, Chase; Luo, Hong; Dahlen, Paul; Gorder, Kyle; Dettenmaier, Erik; Johnson, Paul C

    2015-11-17

    Vapor intrusion (VI) pathway assessment and data interpretation have been guided by an historical conceptual model in which vapors originating from contaminated soil or groundwater diffuse upward through soil and are swept into a building by soil gas flow induced by building underpressurization. Recent studies reveal that alternative VI pathways involving neighborhood sewers, land drains, and other major underground piping can also be significant VI contributors, even to buildings beyond the delineated footprint of soil and groundwater contamination. This work illustrates how controlled-pressure-method testing (CPM), soil gas sampling, and screening-level emissions calculations can be used to identify significant alternative VI pathways that might go undetected by conventional sampling under natural conditions at some sites. The combined utility of these tools is shown through data collected at a long-term study house, where a significant alternative VI pathway was discovered and altered so that it could be manipulated to be on or off. Data collected during periods of natural and CPM conditions show that the alternative pathway was significant, but its presence was not identifiable under natural conditions; it was identified under CPM conditions when measured emission rates were 2 orders of magnitude greater than screening-model estimates and subfoundation vertical soil gas profiles changed and were no longer consistent with the conventional VI conceptual model.

  6. Evaporation of tungsten in vacuum at low hydrogen and water vapor pressures

    International Nuclear Information System (INIS)

    Andrievskij, R.A.; Galkin, E.A.; Khromonozhkin, V.V.

    1981-01-01

    The results of experimental investigations of tungsten evaporation rates in the temperature range 1650-2500 K, partial hydrogen and water vapours pressures 1x10 -5 -10 Pa are presented. Experi-- mental plant, equipment employed and radiometric technique of tungsten evaporation study are described. The dependences of evaporation rate and probabilities of tungsten oxidation by residual vacuum water vapours and dependences of tungsten evaporation rate on partial hydrogen and water vapours pressures are determined [ru

  7. Density and vapour pressure of mixed-solvent desiccant systems (propylene glycol or dipropylene glycol or tripropylene glycol + magnesium chloride + water)

    International Nuclear Information System (INIS)

    Chen, Shang-Yi; Soriano, Allan N.; Leron, Rhoda B.; Li, Meng-Hui

    2014-01-01

    In this present work, new experimental data for density and vapour pressure of the mixed-solvent desiccant systems containing {40 wt% glycol (propylene or dipropylene or tripropylene) + (4 or 9 or 16 wt%) magnesium chloride salt + water} were reported for temperatures up to 343.15 K at normal atmospheric condition. The density and vapour pressure data obtained are presented as a function of temperature and composition. An empirical equation was used to correlate the temperature and compositional dependence of the density values. A model based on the mean spherical approximation for aqueous electrolyte solutions incorporating the pseudo-solvent approach was used to represent the vapour pressure as a function of temperature and composition. Satisfactory results were obtained for both density and vapour pressure calculations

  8. On the Origin of Light Emission in Silicon Rich Oxide Obtained by Low-Pressure Chemical Vapor Deposition

    Directory of Open Access Journals (Sweden)

    M. Aceves-Mijares

    2012-01-01

    Full Text Available Silicon Rich Oxide (SRO has been considered as a material to overcome the drawbacks of silicon to achieve optical functions. Various techniques can be used to produce it, including Low-Pressure Chemical Vapor Deposition (LPCVD. In this paper, a brief description of the studies carried out and discussions of the results obtained on electro-, cathode-, and photoluminescence properties of SRO prepared by LPCVD and annealed at 1,100°C are presented. The experimental results lead us to accept that SRO emission properties are due to oxidation state nanoagglomerates rather than to nanocrystals. The emission mechanism is similar to Donor-Acceptor decay in semiconductors, and a wide emission spectrum, from 450 to 850 nm, has been observed. The results show that emission is a function of both silicon excess in the film and excitation energy. As a result different color emissions can be obtained by selecting the suitable excitation energy.

  9. High-Pressure Water-Vapor Annealing for Enhancement of a-Si:H Film Passivation of Silicon Surface

    International Nuclear Information System (INIS)

    Guo Chun-Lin; Wang Lei; Zhang Yan-Rong; Zhou Hai-Feng; Liang Feng; Yang Zhen-Hui; Yang De-Ren

    2014-01-01

    We investigate the effect of amorphous hydrogenated silicon (a-Si:H) films passivated on silicon surfaces based on high-pressure water-vapor annealing (HWA). The effective carrier lifetime of samples reaches the maximum value after 210°C, 90min HWA. Capacitance-voltage measurement reveals that the HWA not only greatly reduces the density of interface states (D it ), but also decreases the fixed charges (Q fixed ) mainly caused by bulk defects. The change of hydrogen and oxygen in the film is measured by a spectroscopic ellipsometer and a Fourier-transform infrared (FTIR) spectrometer. All these results show that HWA is a useful method to improve the passivation effect of a-Si:H films deposited on silicon surfaces

  10. Temperature dependence of InN growth on (0001) sapphire substrates by atmospheric pressure hydride vapor phase epitaxy

    International Nuclear Information System (INIS)

    Kumagai, Yoshinao; Adachi, Hirokazu; Otake, Aya; Higashikawa, Yoshihiro; Togashi, Rie; Murakami, Hisashi; Koukitu, Akinori

    2010-01-01

    The temperature dependence of InN growth on (0001) sapphire substrates by atmospheric pressure hydride vapor phase epitaxy (HVPE) was investigated. N-polarity single-crystal InN layers were successfully grown at temperatures ranging from 400 to 500 C. The a and c lattice constants of InN layers grown at 450 C or below were slightly larger than those of InN layers grown above 450 C due to oxygen incorporation that also increased the carrier concentration. The optical absorption edge of the InN layer decreased from above 2.0 to 0.76 eV when the growth temperature was increased from 450 to 500 C. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. A phenomenological one-parameter equation of state for osmotic pressures of PEG and other neutral flexible polymers in good solvents

    DEFF Research Database (Denmark)

    Cohen, J.A.; Podgornik, R; Hansen, Per Lyngs

    2009-01-01

    We present a phenomenological one-parameter scaling equation of state that accurately represents osmotic pressures of neutral flexible polymers in good solvents from the dilute through the semidilute regime. The equation comprises a sum of scaled van't Hoff and des Cloizeaux terms including a fit...

  12. Kinetics and dynamics of nanosecond streamer discharge in atmospheric-pressure gas bubble suspended in distilled water under saturated vapor pressure conditions

    KAUST Repository

    Sharma, Ashish

    2016-09-08

    We perform computational studies of nanosecond streamer discharges generated in helium bubbles immersed in distilled water under atmospheric pressure conditions. The model takes into account the presence of water vapor in the gas bubble for an accurate description of the discharge kinetics. We find that the dynamic characteristics of the streamer discharge are different at low and high positive trigger voltages with the axial streamer evolution dominant for low voltages and a surface hugging mode favored for high voltages. We also find a substantial difference in initiation, transition and evolution stages of discharge for positive and negative trigger voltages with the volumetric distribution of species in the streamer channel much more uniform for negative trigger voltages on account of the presence of multiple streamers. We observe that the presence of water vapor does not affect the breakdown voltage even for oversaturated conditions but significantly influences the composition of dominant species in the trail of the streamer as well as the flux of the dominant species on the bubble surface. © 2016 IOP Publishing Ltd.

  13. High-pressure vapor-liquid equilibrium data for CO2-orange peel oil

    Directory of Open Access Journals (Sweden)

    G.R. Stuart

    2000-06-01

    Full Text Available Recently, there has been a growing interest in fractionating orange peel oil by the use of supercritical carbon dioxide (SCCO2. However, progress in this area has been hindered by the lack of more comprehensive work concerning the phase equilibrium behavior of the SCCO2-orange peel oil system. In this context, the aim of this work is to provide new phase equilibrium data for this system over a wide range of temperatures and pressures, permitting the construction of coexistence PT-xy curves as well as the P-T diagram. The experiments were performed in a high-pressure variable-volume view cell in the temperature range of 50-70ºC from 70 to 135 atm and in the CO2 mass fraction composition range of 0.35-0.98. Based on the experimental phase equilibrium results, appropriate operating conditions can be set for high-pressure fractionation purposes.

  14. Properties of solvent-borne acrylic pressure-sensitive adhesives synthesized by a simple approach

    Directory of Open Access Journals (Sweden)

    2009-12-01

    Full Text Available Acrylic polymers are widely used for fabricating pressure-sensitive adhesives (PSAs with the inherent unique advantages of transparency and superior intrinsic adhesive properties over other polymer-based adhesives. In this study, we have developed and evaluated a method of obtaining by radical copolymerization PSAs for liquid crystalline (LCD applications. Various factors including the amount of monomers, amount of cross-linker, coating weight, dwell time and thermal treatment are investigated for further optimizing the properties of acrylic polymer based PSAs to meet the emerging strict requirements for practical uses related mainly to holding powder and peel strength. The results illustrate that novel crosslinking reagents coupled with the thermal treatment at 70°C can make the resultant PSAs with the improved adhesive properties. The coating weight variation from 10 to 40 g/m2 can significantly enhance the peel strength from 4.0 g/25 mm to 12.5 g/25 mm with about 310% increment. If the dwell time of PSAs with cross-linking reagent is more than 10 hrs, the peel strength can be reduced down to a suitable value to meet the criterion for use. Therefore, acrylic PSAs with peel strength less than 20 g/25 mm and holding power above 120 hrs were successfully synthesized by elaborately designing the reaction system, which are practically applicable for advanced industrial applications.

  15. Preparation of high-pressure phase boron nitride films by physical vapor deposition

    CERN Document Server

    Zhu, P W; Zhao, Y N; Li, D M; Liu, H W; Zou Guang Tian

    2002-01-01

    The high-pressure phases boron nitride films together with cubic, wurtzic, and explosive high-pressure phases, were successfully deposited on the metal alloy substrates by tuned substrate radio frequency magnetron sputtering. The percentage of cubic boron nitride phase in the film was about 50% as calculated by Fourier transform infrared measurements. Infrared peak position of cubic boron nitride at 1006.3 cm sup - sup 1 , which is close to the stressless state, indicates that the film has very low internal stress. Transition electron microscope micrograph shows that pure cubic boron nitride phase exits on the surface of the film. The growth mechanism of the BN films was also discussed.

  16. Buoyancy-Driven Heat Transfer During Application of a Thermal Gradient for the Study of Vapor Deposition at Low Pressure Using and Ideal Gas

    Science.gov (United States)

    Frazier, D. O.; Hung, R. J.; Paley, M. S.; Penn, B. G.; Long, Y. T.

    1996-01-01

    A mathematical model has been developed to determine heat transfer during vapor deposition of source materials under a variety of orientations relative to gravitational accelerations. The model demonstrates that convection can occur at total pressures as low as 10-2 mm Hg. Through numerical computation, using physical material parameters of air, a series of time steps demonstrates the development of flow and temperature profiles during the course of vapor deposition. These computations show that in unit gravity vapor deposition occurs by transport through a fairly complicated circulating flow pattern when applying heat to the bottom of the vessel with parallel orientation with respect to the gravity vector. The model material parameters for air predict the effect of kinematic viscosity to be of the same order as thermal diffusivity, which is the case for Prandtl number approx. 1 fluids. Qualitative agreement between experiment and the model indicates that 6-(2-methyl-4-nitroanilino)-2,4-hexadiyn-l-ol (DAMNA) at these pressures indeed approximates an ideal gas at the experiment temperatures, and may validate the use of air physical constants. It is apparent that complicated nonuniform temperature distribution in the vapor could dramatically affect the homogeneity, orientation, and quality of deposited films. The experimental test i's a qualitative comparison of film thickness using ultraviolet-visible spectroscopy on films generated in appropriately oriented vapor deposition cells. In the case where heating of the reaction vessel occurs from the top, deposition of vapor does not normally occur by convection due to a stable stratified medium. When vapor deposition occurs in vessels heated at the bottom, but oriented relative to the gravity vector between these two extremes, horizontal thermal gradients induce a complex flow pattern. In the plane parallel to the tilt axis, the flow pattern is symmetrical and opposite in direction from that where the vessel is

  17. Optimization of carbon nanotube powder growth using low pressure floating catalytic chemical vapor deposition

    International Nuclear Information System (INIS)

    Chen, Y.; Sun, Z.; Li, Y.N.; Tay, B.K.

    2006-01-01

    A new approach to synthesize carbon nanotube (CNT) powders has been achieved by using the floating catalyst method below atmospheric pressure. Scanning electron microscopy, Raman spectroscopy and high-resolution transmission electron microscopy were utilized to characterize the CNTs samples. Using ferrocene (FeC 10 H 10 ) as catalyst precursor, cyclohexane (C 6 H 12 ) as carbon source, H 2 as carrier gas and thiophene (C 4 H 4 S) as promoter, it is found that the pressure of 15 kPa, temperature of 650 deg. C and H 2 flow rate of 60 sccm would be the optimization condition for synthesis of high quality CNTs. This method is economical and easily scalable for synthesis of CNTs

  18. Long Term Measurement of the Vapor Pressure of Gold in the Au-C System

    Science.gov (United States)

    Copland, Evan H.

    2009-01-01

    Incorporating the {Au(s,l) + graphite} reference in component activity measurements made with the multiple effusion-cell vapor source mass spectrometry (multicell KEMS) technique provides a fixed temperature defining ITS-90 (T(sub mp)(Au) = 1337.33K) and a systematic method to check accuracy. Over a 2 year period delta H sub(298)Au was determined by the 2nd and 3rd law methods in 25 separate experiments and were in the ranges 362.2 plus or minus 3.3 kJmol(sup -1) and 367.8 plus or minus 1.1 kJmol(sup -1), respectively. This 5 kJmol-1 discrepancy is transferred directly to the measured activities. This is unacceptable and the source of this discrepancy needs to be understood and corrected. Accepting the 2nd law value increases p(Au) by about 50 percent, brings the 2nd and 3rd law values into agreement and removes the T dependence in the 3rd law values. While compelling, there is no way to independently determine instrument sensitivities, S(sub Au), with T in a single experiment with KEMS. This lack of capability is stopping a deeper understanding of this problem. In addition, the Au-C phase diagram suggests a eutectic invariant reaction: L-Au(4.7at%C) = FCC-Au(0.08at%C) + C(graphite) at T(sub e) approximately 1323K. This high C concentration in Au(l) must reduce p(Au) in equilibrium with {Au(s,l) + graphite} and raises some critical questions about the Gibbs free energy functions of Au(s,l) and the Au fixed point (T(sub mp)(Au) = 1337.33K) which is always measured in graphite.

  19. Identifying Liquid-Gas System Misconceptions and Addressing Them Using a Laboratory Exercise on Pressure-Temperature Diagrams of a Mixed Gas Involving Liquid-Vapor Equilibrium

    Science.gov (United States)

    Yoshikawa, Masahiro; Koga, Nobuyoshi

    2016-01-01

    This study focuses on students' understandings of a liquid-gas system with liquid-vapor equilibrium in a closed system using a pressure-temperature ("P-T") diagram. By administrating three assessment questions concerning the "P-T" diagrams of liquid-gas systems to students at the beginning of undergraduate general chemistry…

  20. Multi-component vapor-liquid equilibrium model for LES of high-pressure fuel injection and application to ECN Spray A

    NARCIS (Netherlands)

    Matheis, Jan; Hickel, S.

    2018-01-01

    We present and evaluate a two-phase model for Eulerian large-eddy simulations (LES) of liquid-fuel injection and mixing at high pressure. The model is based on cubic equations of state and vapor-liquid equilibrium calculations and can represent the coexistence of supercritical states and

  1. Undoped and in-situ B doped GeSn epitaxial growth on Ge by atmospheric pressure-chemical vapor deposition

    DEFF Research Database (Denmark)

    Vincent, B.; Gencarelli, F.; Bender, H.

    2011-01-01

    In this letter, we propose an atmospheric pressure-chemical vapor deposition technique to grow metastable GeSn epitaxial layers on Ge. We report the growth of defect free fully strained undoped and in-situ B doped GeSn layers on Ge substrates with Sit contents up to 8%. Those metastable layers stay...

  2. The gas phase emitter effect of lanthanum within ceramic metal halide lamps and its dependence on the La vapor pressure and operating frequency

    Energy Technology Data Exchange (ETDEWEB)

    Ruhrmann, C.; Hoebing, T.; Bergner, A.; Groeger, S.; Awakowicz, P.; Mentel, J. [Electrical Engineering and Plasma Technology, Ruhr University Bochum, D-44780 Bochum (Germany); Denissen, C.; Suijker, J. [Philips Lighting, Category Professional Lamps, P.O. Box 80020, NL-5600JM Eindhoven (Netherlands)

    2015-08-07

    The gas phase emitter effect increases the lamp lifetime by lowering the work function and, with it, the temperature of the tungsten electrodes of metal halide lamps especially for lamps in ceramic vessels due to their high rare earth pressures. It is generated by a monolayer on the electrode surface of electropositive atoms of certain emitter elements, which are inserted into the lamp bulb by metal iodide salts. They are vaporized, dissociated, ionized, and deposited by an emitter ion current onto the electrode surface within the cathodic phase of lamp operation with a switched-dc or ac-current. The gas phase emitter effect of La and the influence of Na on the emitter effect of La are studied by spatially and phase-resolved pyrometric measurements of the electrode tip temperature, La atom, and ion densities by optical emission spectroscopy as well as optical broadband absorption spectroscopy and arc attachment images by short time photography. An addition of Na to the lamp filling increases the La vapor pressure within the lamp considerably, resulting in an improved gas phase emitter effect of La. Furthermore, the La vapor pressure is raised by a heating of the cold spot. In this way, conditions depending on the La vapor pressure and operating frequency are identified, at which the temperature of the electrodes becomes a minimum.

  3. 42 CFR 84.163 - Man test for gases and vapors; Type C supplied-air respirators, demand and pressure-demand...

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Man test for gases and vapors; Type C supplied-air respirators, demand and pressure-demand classes; test requirements. 84.163 Section 84.163 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF...

  4. Vapor Pressure Measurements of LiBH4, NaBH 4 and Ca(BH4)2 using Knudsen Torsion Effusion Gravimetric Method

    Science.gov (United States)

    Danyan, Mohammad Masoumi

    Hydrogen storage is one of the critical technologies needed on the path towards commercialization for mobile applications. In the past few years, a range of new light weight hydrogen containing material has been discovered with good storage properties. Among them, lithium borohydride (LiBH 4) sodium borohydride (NaBH4) and calcium borohydride (Ca(BH 4)2) have shown promising results to be used as solid state hydrogen storage material. In this work, we have determined equilibrium vapor pressures of LiBH 4 NaBH4 and Ca(BH4)2 obtained by Torsion effusion thermogravimetric method. Results for all the three hydrides exhibited that a small fraction of the materials showed congruency, and sublimed as gaseous compound, but the majority of the material showed incongruent vaporization. Two Knudsen cells of 0.3 and 0.6mm orifice size was employed to measure the total vapor pressures. A Whitman-Motzfeldt method is used to extrapolate the measured vapor pressures to zero orifice size to calculate the equilibrium vapor pressures. In the case of LiBH4 we found that 2% of the material evaporated congruently (LiBH4(s) → LiBH4(g)) according to the equation: logPLiBH4/P 0 =-3263.5 +/-309/T + (1.079 +/-0.69) and rest as incongruent vaporization to LiH, B, and hydrogen gas according to the equation logPeq/P0 =(-3263.5 +/-309)/T+ (2.458 +/-0.69) with DeltaH evap.= 62.47+/-5.9 kJ/mol of H2, DeltaSevap. = 47.05+/-13 J/mol of H2.K. The NaBH4 also had somewhat similar behavior, with 9% congruent evaporation and equilibrium vapor pressure equation of logPLiBH4=-7700+/-335/ T+ (6.7+/-1.5) and 91% incongruent decomposition to Na and Boron metal, and hydrogen gas. The enthalpy of vaporization; DeltaHevap. = 147.2+/-6.4kJ/molH2 and DeltaSevap.= 142 +/-28 kJ/molH2.K (550-650K). The Ca(BH4) 2 exhibited similar vaporization behavior with congruency of 3.2%. The decomposition products are CaH2 and Boron metal with evolution of hydrogen gas varying with the pressure equation as logPeq /P0 =(-1562

  5. Highly ionized physical vapor deposition plasma source working at very low pressure

    Czech Academy of Sciences Publication Activity Database

    Straňák, V.; Herrendorf, A.-P.; Drache, S.; Čada, Martin; Hubička, Zdeněk; Tichý, M.; Hippler, R.

    2012-01-01

    Roč. 100, č. 14 (2012), "141604-1"-"141604-3" ISSN 0003-6951 R&D Projects: GA TA ČR TA01010517; GA ČR(CZ) GAP205/11/0386; GA ČR GAP108/12/1941 Institutional research plan: CEZ:AV0Z10100522 Keywords : magnetron * ECWR * low-pressure * sputtering * plasma diagnostics Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.794, year: 2012 http://dx.doi.org/10.1063/1.3699229

  6. Effect of water vapor on sound absorption in nitrogen at low frequency/pressure ratios

    Science.gov (United States)

    Zuckerwar, A. J.; Griffin, W. A.

    1981-01-01

    Sound absorption measurements were made in N2-H2O binary mixtures at 297 K over the frequency/pressure range f/P of 0.1-2500 Hz/atm to investigate the vibrational relaxation peak of N2 and its location on f/P axis as a function of humidity. At low humidities the best fit to a linear relationship between the f/P(max) and humidity yields an intercept of 0.013 Hz/atm and a slope of 20,000 Hz/atm-mole fraction. The reaction rate constants derived from this model are lower than those obtained from the extrapolation of previous high-temperature data.

  7. Thermodynamics of the multicomponent vapor-liquid equilibrium under capillary pressure difference

    DEFF Research Database (Denmark)

    Shapiro, Alexander; Stenby, Erling Halfdan

    2001-01-01

    We discuss the two-phase multicomponent equilibrium, provided that the phase pressures are different due to the action of capillary forces. We prove the two general properties of such an equilibrium, which have previously been known for a single-component case, however, to the best of our knowledge......, not for the multicomponent mixtures. The importance is emphasized on the space of the intensive variables P, T and mu (i), where the laws of capillary equilibrium have a simple geometrical interpretation. We formulate thermodynamic problems specific to such an equilibrium, and outline changes to be introduced to common...... algorithms of flash calculations in order to solve these problems. Sample calculations show large variation of the capillary properties of the mixture in the very neighborhood of the phase envelope and the restrictive role of the spinodal surface as a boundary for possible equilibrium states with different...

  8. Hydrogenation of Isophthalonitrile with 1-Methylimidazole as an Effective Solvent for m-Xylenediamine Production

    Energy Technology Data Exchange (ETDEWEB)

    Chae, Tae Young; Row, Sung Wook; Yoo, Kye Sang; Lee, Sang Duek [Environment and Process Technology Division, Seoul (Korea, Republic of); Lee, Do Weon [University of Seoul, Seoul (Korea, Republic of)

    2006-03-15

    1-methylimidazole was shown to outperform the other organic solvents in this reaction. Moreover, amount of ammonia with using 1-methylimidazole as a solvent was lower than other processes. Thus, 1-methylimidazole is an attractive solvent in IPN hydrogenation for the production of MXDA. The correct choice of a solvent is a critical factor to govern the catalytic activity with desirable hydrogenation. Conventionally, organic materials such as aromatic hydrocarbons, aliphatic alcohols, aliphatic hydrocarbons, dimethylformamide and dioxane were employed in this reaction. Several MXDA producing processes with the organic solvent including m-xylene, pseudocumene, mesitylene, ethylbenzene, methylpyridine, benzonitrile, m-tolunitrile, MXDA and cyanopyridine were disclosed. However, the solvents and ammonia were vaporized under the operation conditions leading to amine cleavage with the resulting formation of methylbenzyl amines or the consumption of ammonia was still significant. Recently, some researchers reported that a high yield of MXDA was achieved using isopropanol under relatively low pressure condition; however, the consumption of ammonia was very significant.

  9. Some properties of low-vapor-pressure braze alloys for thermionic converters

    Science.gov (United States)

    Bair, V. L.

    1978-01-01

    Density, dc electrical resistivity, thermal conductivity, and linear thermal expansion are measured for arc-melted rod-shaped samples of binary eutectics of Zr, Hf, Ru, Nb, Ir, Mo, Ta, Os, Re, and W selected as very-low-pressure braze fillers for thermionic converters. The first two properties are measured at 296 K for Zr-21.7 at% Ru, Zr-13 wt% W, Zr-19 wt% W, Zr-22.3 at% Nb, Nb-66.9 at% Ru, Hf-25.3 wt% Re, Zr-25.7 at% Ta, Hf-22.5 at% W, and Nb-35 wt% Mo. The last property is measured from 293 K to 2/3 melting point for specified alloys of different compositions. Resistivities of 0.000055 to 0.000181 ohm-cm are observed with the alloys having resistivities about ten times that of the less resistive constituent metal and about three times that of the more resistive constituent metal, except for Zr-19 wt% W and Nb-35 wt% Mo (greater resistivities). Thermal expansion coefficients vary from 0.000006 to 0.0000105/K. All brazes exhibit linear thermal expansion near that of their constituent metals.

  10. Vapor pressures and isopiestic molalities of concentrated CaCl{sub 2}(aq), CaBr{sub 2}(aq), and NaCl(aq) to T = 523 K

    Energy Technology Data Exchange (ETDEWEB)

    Gruszkiewicz, Miroslaw S. [Oak Ridge National Laboratory, Chemical Sciences Division, P.O. Box 2008, Building 4500S MS-6110, Oak Ridge, TN 37831-6110 (United States)]. E-mail: gruszkiewicz@ornl.gov; Simonson, John M. [Oak Ridge National Laboratory, Chemical Sciences Division, P.O. Box 2008, Building 4500S MS-6110, Oak Ridge, TN 37831-6110 (United States)]. E-mail: simonsonjm@ornl.gov

    2005-09-15

    The Oak Ridge National Laboratory high-temperature isopiestic apparatus was outfitted with precise pressure gauges to allow for direct vapor pressure measurements. Vapor pressures over concentrated solutions of CaCl{sub 2}(aq), and CaBr{sub 2}(aq) were measured at temperatures between (380.15 and 523.15) K in the range of water activities between 0.2 and 0.85. Isopiestic molalities were used to determine osmotic coefficients at the conditions where NaCl reference standard solutions remained undersaturated. The main goal of this work was to improve the accuracy of isopiestic comparisons based on the calcium chloride reference standard. Osmotic coefficients for CaCl{sub 2}(aq) and CaBr{sub 2}(aq) calculated from both isopiestic and direct vapor pressure results were combined with the literature data and used to build general thermodynamic models based on a variant of extended Pitzer ion-interaction equations and valid at the saturation pressure of water. While these empirical models approach the accuracy of the experimental data in a wider range of concentrations and temperatures than any previously published equations, considerable amounts of accurate data and a substantial effort are required in order to obtain a satisfactory representation using power series-based virial equations. The effect of experimental uncertainties on the accuracy of the direct vapor pressure results is discussed, including in particular the error caused by the presence in the apparatus of a small amount of CO{sub 2}. The substantial decrease of the solubility product of CaCO{sub 3} in concentrated chloride solutions at temperatures above 423 K is a serious defect of calcium chloride as a water activity reference standard.

  11. Vapor pressures and isopiestic molalities of concentrated CaCl2(aq), CaBr2(aq), and NaCl(aq) to T = 523 K

    International Nuclear Information System (INIS)

    Gruszkiewicz, Miroslaw S.; Simonson, John M.

    2005-01-01

    The Oak Ridge National Laboratory high-temperature isopiestic apparatus was outfitted with precise pressure gauges to allow for direct vapor pressure measurements. Vapor pressures over concentrated solutions of CaCl 2 (aq), and CaBr 2 (aq) were measured at temperatures between (380.15 and 523.15) K in the range of water activities between 0.2 and 0.85. Isopiestic molalities were used to determine osmotic coefficients at the conditions where NaCl reference standard solutions remained undersaturated. The main goal of this work was to improve the accuracy of isopiestic comparisons based on the calcium chloride reference standard. Osmotic coefficients for CaCl 2 (aq) and CaBr 2 (aq) calculated from both isopiestic and direct vapor pressure results were combined with the literature data and used to build general thermodynamic models based on a variant of extended Pitzer ion-interaction equations and valid at the saturation pressure of water. While these empirical models approach the accuracy of the experimental data in a wider range of concentrations and temperatures than any previously published equations, considerable amounts of accurate data and a substantial effort are required in order to obtain a satisfactory representation using power series-based virial equations. The effect of experimental uncertainties on the accuracy of the direct vapor pressure results is discussed, including in particular the error caused by the presence in the apparatus of a small amount of CO 2 . The substantial decrease of the solubility product of CaCO 3 in concentrated chloride solutions at temperatures above 423 K is a serious defect of calcium chloride as a water activity reference standard

  12. Polarization memory of blue and red luminescence from nanocrystalline porous silicon treated by high-pressure water vapor annealing

    International Nuclear Information System (INIS)

    Gelloz, B.; Koyama, H.; Koshida, N.

    2008-01-01

    The polarization memory (PM) effect in the blue and red photoluminescence (PL) of p-type porous Si (PS) treated by high-pressure water vapor annealing (HWA) has been investigated. HWA induces a significant blue PL emission at about 450 nm, together with a drastic enhancement of the red PL intensity. The polarization memory of the red emission band is anisotropic and is in agreement with emission from quantum sized Si nanocrystals, whereas that of the blue band is high and isotropic, indicating an emission mechanism related to localized states in the amorphous Si oxide surrounding the Si skeleton of the PS layer after HWA. HWA does not induce any blue emission in PS that was electrochemically oxidized (ECO) beforehand because the electrochemically grown oxide tends to prevent the formation of blue-emitting amorphous oxide upon HWA. The PM of ECO-PS at low emission energies is anisotropic, but in a direction 45 deg. rotated compared to that of PS treated by HWA. This unique behavior may be related to the electrical nature of electrochemical oxidation. HWA increases the PM of ECO-PS. This could be attributed to the enhanced passivation induced by HWA

  13. Quantitative relationships for the prediction of the vapor pressure of some hydrocarbons from the van der Waals molecular surface

    Directory of Open Access Journals (Sweden)

    Olariu Tudor

    2015-01-01

    Full Text Available A quantitative structure - property relationship (QSPR modeling of vapor pressure at 298.15 K, expressed as log (VP / Pa was performed for a series of 84 hydrocarbons (63 alkanes and 21 cycloalkanes using the van der Waals (vdW surface area, SW/Å2, calculated by the Monte Carlo method, as the molecular descriptor. The QSPR model developed from the subset of 63 alkanes (C1-C16, deemed as the training set, was successfully used for the prediction of the log (VP / Pa values of the 21 cycloalkanes, which was the external prediction (test subset. A QSPR model was also developed for a series composed of all 84 hydrocarbons. Both QSPR models were statistically tested for their ability to fit the data and for prediction. The results showed that the vdW molecular surface used as molecular descriptor (MD explains the variance of the majority of the log (VP / Pa values in this series of 84 hydrocarbons. This MD describes very well the intermolecular forces that hold neutral molecules together. The clear physical meaning of the molecular surface values, SW/Å2, could explain the success of the QSPR models obtained with a single structural molecular descriptor.

  14. Synthesis and characterization of graphene layers prepared by low-pressure chemical vapor deposition using triphenylphosphine as precursor

    Energy Technology Data Exchange (ETDEWEB)

    Mastrapa, G.C.; Maia da Costa, M.E.H. Maia [Departamento de Física, Pontifícia Universidade Católica do Rio de Janeiro, 22451-900, Rio de Janeiro, RJ (Brazil); Larrude, D.G., E-mail: dunigl@vdg.fis.puc-rio.br [Departamento de Física, Pontifícia Universidade Católica do Rio de Janeiro, 22451-900, Rio de Janeiro, RJ (Brazil); Freire, F.L. [Departamento de Física, Pontifícia Universidade Católica do Rio de Janeiro, 22451-900, Rio de Janeiro, RJ (Brazil); Brazilian Center for Physical Research, 22290-180, Rio de Janeiro, RJ (Brazil)

    2015-09-15

    The synthesis of a single-layer graphene using a low-pressure Chemical Vapor Deposition (CVD) system with triphenylphosphine as precursor is reported. The amount of triphenylphosphine used as precursor was in the range of 10–40 mg. Raman spectroscopy was employed to analyze samples prepared with 10 mg of the precursor, and these spectra were found typical of graphene. The Raman measurements indicate that the progressive degradation of graphene occurs as the amount of triphenylphosphine increases. X-ray photoelectron spectroscopy measurements were performed to investigate the different chemical environments involving carbon and phosphorous atoms. Scanning electron microscopy and transmission electron microscopy were also employed and the results reveal the formation of dispersed nanostructures on top of the graphene layer, In addition, the number of these nanostructures is directly related to the amount of precursor used for sample growth. - Highlights: • We grow graphene using the solid precursor triphenylphosphine. • Raman analysis confirms the presence of monolayer graphene. • SEM images show the presence of small dark areas dispersed on the graphene surface. • Raman I{sub D}/I{sub G} ratio increases in the dark region of the graphene surface.

  15. Photosynthesis Decrease and Stomatal Control of Gas Exchange in Abies alba Mill. in Response to Vapor Pressure Difference.

    Science.gov (United States)

    Guehl, J M; Aussenac, G

    1987-02-01

    The responses of steady state CO(2) assimilation rate (A), transpiration rate (E), and stomatal conductance (g(s)) to changes in leaf-to-air vapor pressure difference (DeltaW) were examined on different dates in shoots from Abies alba trees growing outside. In Ecouves, a provenance representative of wet oceanic conditions in Northern France, both A and g(s) decreased when DeltaW was increased from 4.6 to 14.5 Pa KPa(-1). In Nebias, which represented the dry end of the natural range of A. alba in southern France, A and g(s) decreased only after reaching peak levels at 9.0 and 7.0 Pa KPa(-1), respectively. The representation of the data in assimilation rate (A) versus intercellular CO(2) partial pressure (C(i)) graphs allowed us to determine how stomata and mesophyll photosynthesis interacted when DeltaW was increased. Changes in A were primarily due to alterations in mesophyll photosynthesis. At high DeltaW, and especially in Ecouves when soil water deficit prevailed, A declined, while C(i) remained approximately constant, which may be interpreted as an adjustment of g(s) to changes in mesophyll photosynthesis. Such a stomatal control of gas exchange appeared as an alternative to the classical feedforward interpretation of E versus DeltaW responses with a peak rate of E. The gas exchange response to DeltaW was also characterized by considerable deviations from the optimization theory of IR Cowan and GD Farquhar (1977 Symp Soc Exp Biol 31: 471-505).

  16. Contribution of low vapor pressure-volatile organic compounds (LVP-VOCs) from consumer products to ozone formation in urban atmospheres

    Science.gov (United States)

    Shin, Hyeong-Moo; McKone, Thomas E.; Bennett, Deborah H.

    2015-05-01

    Because recent laboratory testing indicates that some low vapor pressure-volatile organic compounds (LVP-VOC) solvents readily evaporate at ambient conditions, LVP-VOCs used in some consumer product formulations may contribute to ozone formation. The goal of this study is to determine the fraction of LVP-VOCs available for ozone formation from the use of consumer products for two hypothetical emissions. This study calculates and compares the fraction of consumed product available for ozone formation as a result of (a) volatilization to air during use and (b) down-the-drain disposal. The study also investigates the impact of different modes of releases on the overall fraction available in ambient air for ozone formation. For the portion of the LVP-VOCs volatilized to air during use, we applied a multi-compartment mass-balance model to track the fate of emitted LVP-VOCs in a multimedia urban environment. For the portion of the LVP-VOCs disposed down the drain, we used a wastewater treatment plant (WWTP) fate model to predict the emission rates of LVP-VOCs to ambient air at WWTPs or at the discharge zone of the facilities and then used these results as emissions in the multimedia urban environment model. In a WWTP, the LVP-VOCs selected in this study are primarily either biodegraded or removed via sorption to sludge depending on the magnitude of the biodegradation half-life and the octanol-water partition coefficient. Less than 0.2% of the LVP-VOCs disposed down the drain are available for ozone formation. In contrast, when the LVP-VOC in a consumer product is volatilized from the surface to which it has been applied, greater than 90% is available for photochemical reactions either at the source location or in the downwind areas. Comparing results from these two modes of releases allows us to understand the importance of determining the fraction of LVP-VOCs volatilized versus disposed down the drain when the product is used by consumers. The results from this study

  17. Solvent Composition-Dependent Signal-Reduction of Molecular Ions Generated from Aromatic Compounds in (+) Atmospheric Pressure Photo Ionization Mass Spectrometry.

    Science.gov (United States)

    Lee, Seulgidaun; Ahmed, Arif; Kim, Sunghwan

    2018-03-30

    The ionization process is essential for successful mass spectrometry (MS) analysis because of its influence on selectivity and sensitivity. In particular, certain solvents reduce the ionization of the analyte, thereby reducing the overall sensitivity in APPI. Since the sensitivity varies greatly depending on the solvents, a fundamental understanding of the mechanism is required. Standard solutions were analyzed by (+) Atmospheric pressure photo ionization (APPI) QExactive ion trap mass spectrometer (Thermo Scientific). Each solution was infused directly to the APPI source at a flow rate 100 μl/min and the APPI source temperature was 300 °C. Other operating mass spectrometric parameters were maintained under the same conditions. Quantum mechanical calculations were carried out using the Gaussian 09 suite program. Density functional theory was used to calculate the reaction enthalpies (∆H) of reaction between toluene and other solvents. The experimental and theoretical results showed good agreement. The abundances of analyte ions were well correlated with the calculated ∆H values. Therefore, the results strongly support the suggested signal reduction mechanism. In addition, linear correlations between the abundance of toluene and analyte molecular ions were observed, which also supports the suggested mechanism. A solvent composition-dependent signal reduction mechanism was suggested and evaluated for the (+) atmospheric pressure photo ionization (APPI) mass spectrometry analysis of poly-aromatic hydrocarbons (PAHs) generating mainly molecular ions. Overall, the evidence provided in this work suggests that reactions between solvent cluster(s) and toluene molecular ions are responsible for the observed signal reductions. This article is protected by copyright. All rights reserved.

  18. Vapor pressures and standard molar enthalpies, entropies, and Gibbs free energies of sublimation of 2,4- and 3,4-dinitrobenzoic acids

    International Nuclear Information System (INIS)

    Vecchio, Stefano; Brunetti, Bruno

    2009-01-01

    The vapor pressures of the solid and liquid 2,4- and 3,4-dinitrobenzoic acids were determined by torsion-effusion and thermogravimetry under both isothermal and non-isothermal conditions, respectively. From the temperature dependence of vapor pressure derived by the experimental torsion-effusion and thermogravimetry data the molar enthalpies of sublimation Δ cr g H m 0 ( ) and vaporization Δ l g H m 0 ( ) were determined, respectively, at the middle of the respective temperature intervals. The melting temperatures and the molar enthalpies of fusion of these compounds were measured by d.s.c. Finally, the results obtained by all the methods proposed were corrected at the reference temperature of 298.15 K using the estimated heat capacity differences between gas and liquid for vaporization experiments and the estimated heat capacity differences between gas and solid for sublimation experiments. Therefore, the averages of the standard (p o = 0.1 MPa) molar enthalpies, entropies and Gibbs free energies of sublimation at 298.15 K, have been derived.

  19. Equilíbrio líquido-vapor de solventes na presença de solutos não voláteis

    OpenAIRE

    Parente, Bruno Miguel Ramos

    2009-01-01

    Neste trabalho estudou-se o efeito da adição de alguns sais e líquidos iónicos no equilíbrio líquido-vapor (ELV) de algumas misturas importantes na indústria química, tais como etanol + água, 1-propanol + água, 2-propanol + água, acetona + metanol, acetato de metilo + metanol e clorofórmio + etanol. O conjunto de solutos não voláteis estudados é formado por Ca(NO3)2, CuCl2, NaI, KI, LiNO3, LiCl, NaSCN, KCH3COO, CaCl2, [BMIM][Cl] e [EMIM][triflate]. Em primeiro lugar, realizo...

  20. Nanoscale multilayered and porous carbide interphases prepared by pressure-pulsed reactive chemical vapor deposition for ceramic matrix composites

    International Nuclear Information System (INIS)

    Jacques, S.; Jouanny, I.; Ledain, O.; Maillé, L.; Weisbecker, P.

    2013-01-01

    In Ceramic Matrix Composites (CMCs) reinforced by continuous fibers, a good toughness is achieved by adding a thin film called “interphase” between the fiber and the brittle matrix, which acts as a mechanical fuse by deflecting the matrix cracks. Pyrocarbon (PyC), with or without carbide sub-layers, is typically the material of choice to fulfill this role. The aim of this work was to study PyC-free nanoscale multilayered carbide coatings as interphases for CMCs. Nanoscale multilayered (SiC–TiC) n interphases were deposited by pressure-Pulsed Chemical Vapor Deposition (P-CVD) on single filament Hi-Nicalon fibers and embedded in a SiC matrix sheath. The thicknesses of the carbide interphase sub-layers could be made as low as a few nanometers as evidenced by scanning and transmission electron microscopy. By using the P-ReactiveCVD method (P-RCVD), in which the TiC growth involves consumption of SiC, it was not only possible to obtain multilayered (SiC–TiC) n films but also TiC films with a porous multilayered microstructure as a result of the Kirkendall effect. The porosity in the TiC sequences was found to be enhanced when some PyC was added to SiC prior to total RCVD consumption. Because the porosity volume fraction was still not high enough, the role of mechanical fuse of the interphases could not be evidenced from the tensile curves, which remained fully linear even when chemical attack of the fiber surface was avoided.

  1. Control of the nucleation and quality of graphene grown by low-pressure chemical vapor deposition with acetylene

    International Nuclear Information System (INIS)

    Yang, Meng; Sasaki, Shinichirou; Suzuki, Ken; Miura, Hideo

    2016-01-01

    Graphical abstract: - Highlights: • For the first time, we succeeded in the LPCVD growth of monolayer graphene using acetylene as the precursor gas. • The growth rate is very high when acetylene is used as the source gas. Our process has exhibited the potential to shorten the growth time of CVD graphene. • We found that the domain size, defects density, layer number and the sheet resistance of graphene can be changed by changing the acetylene flow rates. • We found that it is also possible to form bilayer graphene using acetylene. However, further study are necessary to reduce the defects density. - Abstract: Although many studies have reported the chemical vapor deposition (CVD) growth of large-area monolayer graphene from methane, synthesis of graphene using acetylene as the source gas has not been fully explored. In this study, the low-pressure CVD (LPCVD) growth of graphene from acetylene was systematically investigated. We succeeded in regulating the domain size, defects density, layer number and the sheet resistance of graphene by changing the acetylene flow rates. Scanning electron microscopy and Raman spectroscopy were employed to confirm the layer number, uniformity and quality of the graphene films. It is found that a low flow rate of acetylene (0.28 sccm) is required to form high-quality monolayer graphene in our system. On the other hand, the high acetylene flow rate (7 sccm) will induce the growth of the bilayer graphene domains with high defects density. On the basis of selected area electron diffraction (SAED) pattern, the as-grown monolayer graphene domains were analyzed to be polycrystal. We also discussed the relation between the sheet resistacne and defects density in graphene. Our results provide great insights into the understanding of the CVD growth of monolayer and bilayer graphene from acetylene.

  2. C and Si delta doping in Ge by CH_3SiH_3 using reduced pressure chemical vapor deposition

    International Nuclear Information System (INIS)

    Yamamoto, Yuji; Ueno, Naofumi; Sakuraba, Masao; Murota, Junichi; Mai, Andreas; Tillack, Bernd

    2016-01-01

    C and Si delta doping in Ge are investigated using a reduced pressure chemical vapor deposition system to establish atomic-order controlled processes. CH_3SiH_3 is exposed at 250 °C to 500 °C to a Ge on Si (100) substrate using H_2 or N_2 carrier gas followed by a Ge cap layer deposition. At 350 °C, C and Si are uniformly adsorbed on the Ge surface and the incorporated C and Si form steep delta profiles below detection limit of SIMS measurement. By using N_2 as carrier gas, the incorporated C and Si doses in Ge are saturated at one mono-layer below 350 °C. At this temperature range, the incorporated C and Si doses are nearly the same, indicating CH_3SiH_3 is adsorbed on the Ge surface without decomposing the C−Si bond. On the other hand, by using H_2 as carrier gas, lower incorporated C is observed in comparison to Si. CH_3SiH_3 injected with H_2 carrier gas is adsorbed on Ge without decomposing the C−Si bond and the adsorbed C is reduced by dissociation of the C−Si bond during temperature ramp up to 550 °C. The adsorbed C is maintained on the Ge surface in N_2 at 550 °C. - Highlights: • C and Si delta doping in Ge is investigated using RPCVD system by CH_3SiH_3 exposure. • Atomically flat C and Si delta layers are fabricated at 350 °C. • Incorporated C and Si doses are saturated at one mono-layer below 350 °C. • CH_3SiH_3 adsorption occurred without decomposing C−Si bond. • Adsorbed C is desorbed due to dissociation by hydrogen during postannealing at 550 °C.

  3. Characterization of InP/GaAs/Si structures grown by atmospheric pressure metalorganic chemical vapor deposition

    International Nuclear Information System (INIS)

    Pearton, S.J.; Short, K.T.; Macrander, A.T.; Abernathy, C.R.; Mazzi, V.P.; Haegel, N.M.; Al-Jassim, M.M.; Vernon, S.M.; Haven, V.E.

    1989-01-01

    The thickness dependence of material quality of InP-GaAs-Si structures grown by atmospheric pressure metalorganic chemical vapor deposition was investigated. The InP thickness was varied from 1--4 μm, and that of the GaAs from 0.1--4 μm. For a given thickness of InP, its ion channeling yield and x-ray peak width were essentially independent of the GaAs layer thickness. The InP x-ray peak widths were typically 400--440 arcsec for 4-μm-thick layers grown on GaAs. The GaAs x-ray widths in turn varied from 320--1000 arcsec for layer thicknesses from 0.1--4 μm. Cross-sectional transmission electron microscopy showed high defect densities at both the InP-GaAs and GaAs-Si interfaces. In 4-μm-thick InP layers the average threading dislocation density was in the range (3--8) x 10 8 cm -2 with a stacking fault density within the range (0.4--2) x 10 8 cm 2 . The He + ion channeling yield near the InP surface was similar to that of bulk InP (chi/sub min/∼4%), but rose rapidly toward the InP-GaAs heterointerface where it was typically around 50% for 1-μm-thick InP layers. All samples showed room-temperature luminescence, while at 4.4 K, exciton-related transitions, whose intensity was a function of the InP thickness, were observed

  4. Soil Moisture (SMAP) and Vapor Pressure Deficit Controls on Evaporative Fraction over the Continental U.S.

    Science.gov (United States)

    Salvucci, G.; Rigden, A. J.; Gianotti, D.; Entekhabi, D.

    2017-12-01

    We analyze the control over evapotranspiration (ET) imposed by soil moisture limitations and stomatal closure due to vapor pressure deficit (VPD) across the United States using estimates of satellite-derived soil moisture from SMAP and a meteorological, data-driven ET estimate over a two year period at over 1000 locations. The ET data are developed independent of soil moisture using the emergent relationship between the diurnal cycle of the relative humidity profile and ET based on ETRHEQ (Salvucci and Gentine (2013), PNAS, 110(16): 6287-6291, Rigden and Salvucci, 2015, WRR, 51(4): 2951-2973; Rigden and Salvucci, 2017, GCB, 23(3) 1140-1151). The key advantage of using this approach to estimate ET is that no measurements of surface limiting factors (soil moisture, leaf area, canopy conductance) are required; instead, ET is estimated from only meteorological data. The combination of these two independent datasets allows for a unique spatial analysis of the control on ET imposed by the availability of soil moisture vs. VPD. Spatial patterns of limitations are inferred by fitting the ETRHEQ-inferred surface conductance to a weighted sum of a Jarvis type stomatal conductance model and bare soil evaporation conductance model, with separate moisture-dependent evaporation efficiency relations for bare soil and vegetation. Spatial patterns are visualized by mapping the optimal curve fitting coefficients and by conducting sensitivity analyses of the resulting fitted model across the Unites States. Results indicate regional variations in rate-limiting factors, and suggest that in some areas the VPD effect on stomatal closure is strong enough to induce a decrease in ET under projected climate change, despite an increase in atmospheric drying (and thus evaporative demand).

  5. Control of the nucleation and quality of graphene grown by low-pressure chemical vapor deposition with acetylene

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Meng, E-mail: youmou@rift.mech.tohoku.ac.jp [Department of Nanomechanics, Graduate School of Engineering, Tohoku University, Sendai 980-8579 (Japan); Sasaki, Shinichirou [Department of Nanomechanics, Graduate School of Engineering, Tohoku University, Sendai 980-8579 (Japan); Suzuki, Ken; Miura, Hideo [Fracture and Reliability Research Institute, Tohoku University, Sendai 980-8579 (Japan)

    2016-03-15

    Graphical abstract: - Highlights: • For the first time, we succeeded in the LPCVD growth of monolayer graphene using acetylene as the precursor gas. • The growth rate is very high when acetylene is used as the source gas. Our process has exhibited the potential to shorten the growth time of CVD graphene. • We found that the domain size, defects density, layer number and the sheet resistance of graphene can be changed by changing the acetylene flow rates. • We found that it is also possible to form bilayer graphene using acetylene. However, further study are necessary to reduce the defects density. - Abstract: Although many studies have reported the chemical vapor deposition (CVD) growth of large-area monolayer graphene from methane, synthesis of graphene using acetylene as the source gas has not been fully explored. In this study, the low-pressure CVD (LPCVD) growth of graphene from acetylene was systematically investigated. We succeeded in regulating the domain size, defects density, layer number and the sheet resistance of graphene by changing the acetylene flow rates. Scanning electron microscopy and Raman spectroscopy were employed to confirm the layer number, uniformity and quality of the graphene films. It is found that a low flow rate of acetylene (0.28 sccm) is required to form high-quality monolayer graphene in our system. On the other hand, the high acetylene flow rate (7 sccm) will induce the growth of the bilayer graphene domains with high defects density. On the basis of selected area electron diffraction (SAED) pattern, the as-grown monolayer graphene domains were analyzed to be polycrystal. We also discussed the relation between the sheet resistacne and defects density in graphene. Our results provide great insights into the understanding of the CVD growth of monolayer and bilayer graphene from acetylene.

  6. Nanoscale multilayered and porous carbide interphases prepared by pressure-pulsed reactive chemical vapor deposition for ceramic matrix composites

    Science.gov (United States)

    Jacques, S.; Jouanny, I.; Ledain, O.; Maillé, L.; Weisbecker, P.

    2013-06-01

    In Ceramic Matrix Composites (CMCs) reinforced by continuous fibers, a good toughness is achieved by adding a thin film called "interphase" between the fiber and the brittle matrix, which acts as a mechanical fuse by deflecting the matrix cracks. Pyrocarbon (PyC), with or without carbide sub-layers, is typically the material of choice to fulfill this role. The aim of this work was to study PyC-free nanoscale multilayered carbide coatings as interphases for CMCs. Nanoscale multilayered (SiC-TiC)n interphases were deposited by pressure-Pulsed Chemical Vapor Deposition (P-CVD) on single filament Hi-Nicalon fibers and embedded in a SiC matrix sheath. The thicknesses of the carbide interphase sub-layers could be made as low as a few nanometers as evidenced by scanning and transmission electron microscopy. By using the P-ReactiveCVD method (P-RCVD), in which the TiC growth involves consumption of SiC, it was not only possible to obtain multilayered (SiC-TiC)n films but also TiC films with a porous multilayered microstructure as a result of the Kirkendall effect. The porosity in the TiC sequences was found to be enhanced when some PyC was added to SiC prior to total RCVD consumption. Because the porosity volume fraction was still not high enough, the role of mechanical fuse of the interphases could not be evidenced from the tensile curves, which remained fully linear even when chemical attack of the fiber surface was avoided.

  7. Growth CO{sub 2} concentration modifies the transpiration response of Populus deltoides to drought and vapor pressure deficit

    Energy Technology Data Exchange (ETDEWEB)

    Engel, V. C. [South Florida Natural Resources Center, Everglades National Park, Homestead, FL (United States); Griffin, K. L. [Columbia University, Lamont-Doherty Earth Observatory, Palisades, NY (United States); Murthy, R.; Patterson, L.; Klimas, C. [Columbia University, Biosphere 2 Center, Oracle, AZ (United States); Potosnak, M. [National Center for Atmospheric Research, Boulder, CO (United States)

    2004-10-01

    To gain a better understanding of the hydraulic constraints on transpiration, altered canopy water relations in response to elevated carbon dioxide was evaluated in a morphological context. It was expected that by integrating the information gained into predictive models of canopy water balance in elevated carbon dioxide, our understanding of leaf-level responses to drought stresses and evaporative demand will also improve. To achieve these objectives, transpiration rates and leaf-to-sapwood area ratios in clonal stands of cottonwoods grown in near-ambient and elevated carbon dioxide were measured at the Biosphere 2 facility near Oracle, Arizona. Results were interpreted in terms of physical controls versus the direct and indirect effects of growth mediated by morphological changes on transpiration fluxes during periods of drought and high evaporative demand. Leaf-level transpiration rates were found to be nearly equivalent across carbon dioxide treatments when soil water was not limited. However, during drought stress, canopy-level transpiration was roughly equivalent across carbon dioxide treatments, but leaf-level fluxes were reduced in elevated carbon dioxide by a factor equal to the leaf area ratio of the canopies. This shift from equivalent leaf-level transpiration to equivalent canopy-level transpiration with increasing drought stress is taken to mean that maximum water use rates are controlled by atmospheric demand at high soil water content and by soil water availability at low soil water content. Changes in vapor pressure deficits had less pronounced effect on transpiration than changes in soil water content. 37 refs., 3 tabs., 5 figs.

  8. Growth CO2 concentration modifies the transpiration response of Populus deltoides to drought and vapor pressure deficit

    International Nuclear Information System (INIS)

    Engel, V. C.; Griffin, K. L.; Murthy, R.; Patterson, L.; Klimas, C.; Potosnak, M.

    2004-01-01

    To gain a better understanding of the hydraulic constraints on transpiration, altered canopy water relations in response to elevated carbon dioxide was evaluated in a morphological context. It was expected that by integrating the information gained into predictive models of canopy water balance in elevated carbon dioxide, our understanding of leaf-level responses to drought stresses and evaporative demand will also improve. To achieve these objectives, transpiration rates and leaf-to-sapwood area ratios in clonal stands of cottonwoods grown in near-ambient and elevated carbon dioxide were measured at the Biosphere 2 facility near Oracle, Arizona. Results were interpreted in terms of physical controls versus the direct and indirect effects of growth mediated by morphological changes on transpiration fluxes during periods of drought and high evaporative demand. Leaf-level transpiration rates were found to be nearly equivalent across carbon dioxide treatments when soil water was not limited. However, during drought stress, canopy-level transpiration was roughly equivalent across carbon dioxide treatments, but leaf-level fluxes were reduced in elevated carbon dioxide by a factor equal to the leaf area ratio of the canopies. This shift from equivalent leaf-level transpiration to equivalent canopy-level transpiration with increasing drought stress is taken to mean that maximum water use rates are controlled by atmospheric demand at high soil water content and by soil water availability at low soil water content. Changes in vapor pressure deficits had less pronounced effect on transpiration than changes in soil water content. 37 refs., 3 tabs., 5 figs

  9. The effect of halogen hetero-atoms on the vapor pressures and thermodynamics of polycyclic aromatic compounds measured via the Knudsen effusion technique

    International Nuclear Information System (INIS)

    Goldfarb, Jillian L.; Suuberg, Eric M.

    2008-01-01

    Knowledge of vapor pressures of high molar mass organics is essential to predicting their behavior in combustion systems as well as their fate and transport within the environment. This study involved polycyclic aromatic compounds (PACs) containing halogen hetero-atoms, including bromine and chlorine. The vapor pressures of eight PACs, ranging in molar mass from (212 to 336) g . mol -1 , were measured using the isothermal Knudsen effusion technique over the temperature range of (296 to 408) K. These compounds included those with few or no data available in the literature, namely: 1,4-dibromonaphthalene, 5-bromoacenaphthene, 9-bromoanthracene, 1,5-dibromoanthracene, 9,10-dibromoanthracene, 2-chloroanthracene, 9,10-dichloroanthracene, and 1-bromopyrene. Enthalpies of sublimation of these compounds were determined via application of the Clausius-Clapeyron equation. An analysis is presented on the effects of the addition of halogen hetero-atoms to pure polycyclic aromatic hydrocarbons using these data as well as available literature data. As expected, the addition of halogens onto these PACs increases their enthalpies of sublimation and decreases their vapor pressures as compared to the parent compounds

  10. Sub-6 nm Thin Cross-Linked Dopamine Films with High Pressure Stability for Organic Solvent Nanofiltration

    KAUST Repository

    Perez Manriquez, Liliana

    2016-07-11

    Interfacial polymerization of dopamine and terephtaloyl chloride is performed on a porous crosslinked polyacrylonitrile support membrane. The resulting polymer layer has a smooth surface and is ultrathin (about 5 nm). The chemical nature of the interfacially polymerized layer is characterized by Fourier transform infrared spectroscopy and by X-ray photoelectron spectroscopy. The thin-film composite membrane is stable in aggressive solvents like dimethylformamide (DMF) and the membrane shows high solvent permeances combined with a molecular weight cut-off below 800 g mol-1. The remarkable stability in DMF, the ease of preparation as well as the extremely thin and smooth selective layer make this new type of bioinspired membrane attractive for solvent resistant nanofiltration. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. The effect of pressure, isotopic (H/D) substitution, and other variables on miscibility in polymer-solvent systems. The nature of the demixing process; dynamic light scattering and small angle neutron scattering studies. Final report

    International Nuclear Information System (INIS)

    Van Hook, W.A.

    2000-01-01

    A research program examining the effects of pressure, isotope substitution and other variables on miscibility in polymer solvent systems is described. The techniques employed included phase equilibrium measurements and dynamic light scattering and small angle neutron scattering

  12. Note: implementation of a cold spot setup for controlled variation of vapor pressures and its application to an InBr containing discharge lamp.

    Science.gov (United States)

    Briefi, S

    2013-02-01

    In order to allow for a systematic investigation of the plasma properties of discharges containing indium halides, which are proposed as an efficient alternative for mercury based low pressure discharge lamps, a controlled variation of the indium halide density is mandatory. This can be achieved by applying a newly designed setup in which a well-defined cold spot location is implemented and the cold spot temperature can be adjusted between 50 and 350 °C without influencing the gas temperature. The performance of the setup has been proved by comparing the calculated evaporated InBr density (using the vapor pressure curve) with the one measured via white light absorption spectroscopy.

  13. Vapour–Liquid Equilibria in the Polymer + Solvent System Containing Lower Concentrations of Solute at Normal or Reduced Pressures

    Czech Academy of Sciences Publication Activity Database

    Pavlíček, Jan; Bogdanić, Grozdana; Wichterle, Ivan

    2013-01-01

    Roč. 358, 25 NOV (2013), s. 301-303 ISSN 0378-3812 Institutional support: RVO:67985858 Keywords : vapour–liquid equilibrium * experimental data * polymer-solvent system Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.241, year: 2013

  14. Order-Order Transition of C → sdG → sL → S in ABC Triblock Copolymer Thin Film Induced by Solvent Vapor.

    Science.gov (United States)

    Luo, Chunxia; Huang, Weihuan; Han, Yanchun

    2009-04-01

    The morphology transition of polystyrene-block-poly(butadiene)-block-poly(2-vinylpyridine) (SBV) triblock thin film induced in benzene vapor showing weak selectivity for PS is investigated. The order-order transitions (OOT) in the sequence of core-shell cylinders (C), sphere in 'diblock gyroid' (sdG), sphere in lamella (sL) and sphere (S) are observed. The projection along (111) direction in Gyroid phase (sdG(111)) is found to epitaxially grow from C(001) in the film. Instead of sdG(111), sdG(110)(0.1875) develops to the phase of sL. Consequently, the film experiences the transition sequence of sdG(111) → sdG(211) → sdG(110)(0.25)  → sdG(110)(0.1875) between C and sL. The mechanism is analyzed from the total surface area of the blocks. Copyright © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Analysis of vitamin K-1 in fruits and vegetables using accelerated solvent extraction and liquid chromatography tandem mass spectrometry with atmospheric pressure chemical ionization

    DEFF Research Database (Denmark)

    Jäpelt, Rie Bak; Jakobsen, Jette

    2016-01-01

    The objective of this study was to develop a rapid, sensitive, and specific analytical method to study vitamin K-1 in fruits and vegetables. Accelerated solvent extraction and solid phase extraction was used for sample preparation. Quantification was done by liquid chromatography tandem mass...... spectrometry with atmospheric pressure chemical ionization in selected reaction monitoring mode with deuterium-labeled vitamin K1 as an internal standard. The precision was estimated as the pooled estimate of three replicates performed on three different days for spinach, peas, apples, banana, and beetroot...

  16. Thermal and Mechanical Properties of Novolac-Silica Hybrid Aerogels Prepared by Sol-Gel Polymerization in Solvent-Saturated Vapor Atmosphere

    Directory of Open Access Journals (Sweden)

    Mohamad Mehdi Seraji1, Seraji

    2015-05-01

    Full Text Available Nowadays organic–inorganic hybrid aerogel materials have attracted increasing interests due to improved thermal and mechanical properties. In the present research, initially, novolac type phenolic resin-silica hybrid gels with different solid concentrations were synthesized using sol-gel polymerization in solvent-saturatedvapor atmosphere. The hybrid gels were dried at air atmosphere through ambient drying process. This method removed the need for costly and risky supercritical drying process. The yields of the obtained hybrid aerogels increased with less shrinkage in comparison with conventional sol-gel process. The precursor of silica phase in this study was tetraethoxysilane and inexpensive novolac resin was used as a reinforcing phase. The results of FTIR analysis confirmed the simultaneous formation of silica and novolac gels in the hybrid systems. The resultant hybrid aerogels showed a nanostructure hybrid network with high porosity (above 80% and low density (below 0.25 g/cm3. Nonetheless, higher content of silica resulted in more shrinkage in the hybrid aerogel structure due to the tendency of the silica network to shrink more during gelation and drying process. The SEM images of samples exhibited a continuous network of interconnected colloidal particles formed during sol-gel polymerization with mean particle size of less than 100 nanometers. Si mapping analysis showed good distribution of silica phase throughout the hybrid structure. The results demonstrated improvements in insulation properties and thermal stability of novolac-silica aerogel with increasing the silica content. The results of compressive strength showed that the mechanical properties of samples declined with increasing the silica content.

  17. Theoretical effect of concentration, circulation rate, stages, pressure and temperature of single amine and amine mixture solvents on gas sweetening performance

    Directory of Open Access Journals (Sweden)

    Nilay Kumar Sarker

    2016-09-01

    Full Text Available This simulation experiment performed by Aspen Hysys is about theoretical investigation of gas sweetening performance of single amine solvents MEA1, MDEA2, DEA3, DGA4, DIPA5 and mixed amine solvents DGA–MEA, DEA–MDEA and SULFOLANE6–MDEA. Sweet gas having very high percentage of methane is produced by MEA (95.36%, DGA–MEA (95.37%, DEA–MDEA (95.51% and SULFOLANE–MDEA (95.10% and DGA (93.76% shows lowest performance. DGA, SULFOLANE–MDEA, MDEA remove H2S at a lower circulation rate and DEA, DIPA need higher but satisfactory circulation rate. Increasing stage number shows positive effect on DEA, DIPA and SULFOLANE–MDEA. Pressure change has no significant effect. Temperature increase and methane percentage are negatively correlated for all solvents (except low circulating DIPA. With temperature increase H2S composition increases for DEA–MDEA, DGA–MEA; CO2 increases for DEA–MDEA, DGA–MEA and high circulating SULFOLANE–MDEA.

  18. The effect of carrier gas flow rate and source cell temperature on low pressure organic vapor phase deposition simulation by direct simulation Monte Carlo method

    Science.gov (United States)

    Wada, Takao; Ueda, Noriaki

    2013-01-01

    The process of low pressure organic vapor phase deposition (LP-OVPD) controls the growth of amorphous organic thin films, where the source gases (Alq3 molecule, etc.) are introduced into a hot wall reactor via an injection barrel using an inert carrier gas (N2 molecule). It is possible to control well the following substrate properties such as dopant concentration, deposition rate, and thickness uniformity of the thin film. In this paper, we present LP-OVPD simulation results using direct simulation Monte Carlo-Neutrals (Particle-PLUS neutral module) which is commercial software adopting direct simulation Monte Carlo method. By estimating properly the evaporation rate with experimental vaporization enthalpies, the calculated deposition rates on the substrate agree well with the experimental results that depend on carrier gas flow rate and source cell temperature. PMID:23674843

  19. The effect of carrier gas flow rate and source cell temperature on low pressure organic vapor phase deposition simulation by direct simulation Monte Carlo method

    Science.gov (United States)

    Wada, Takao; Ueda, Noriaki

    2013-04-01

    The process of low pressure organic vapor phase deposition (LP-OVPD) controls the growth of amorphous organic thin films, where the source gases (Alq3 molecule, etc.) are introduced into a hot wall reactor via an injection barrel using an inert carrier gas (N2 molecule). It is possible to control well the following substrate properties such as dopant concentration, deposition rate, and thickness uniformity of the thin film. In this paper, we present LP-OVPD simulation results using direct simulation Monte Carlo-Neutrals (Particle-PLUS neutral module) which is commercial software adopting direct simulation Monte Carlo method. By estimating properly the evaporation rate with experimental vaporization enthalpies, the calculated deposition rates on the substrate agree well with the experimental results that depend on carrier gas flow rate and source cell temperature.

  20. Pressure-assisted cold denaturation of hen egg white lysozyme: the influence of co-solvents probed by hydrogen exchange nuclear magnetic resonance.

    Science.gov (United States)

    Vogtt, K; Winter, R

    2005-08-01

    COSY proton nuclear magnetic resonance was used to measure the exchange rates of amide protons of hen egg white lysozyme (HEWL) in the pressure-assisted cold-denatured state and in the heat-denatured state. After dissolving lysozyme in deuterium oxide buffer, labile protons exchange for deuterons in such a way that exposed protons are substituted rapidly, whereas "protected" protons within structured parts of the protein are substituted slowly. The exchange rates k obs were determined for HEWL under heat treatment (80 degrees C) and under high pressure conditions at low temperature (3.75 kbar, -13 degrees C). Moreover, the influence of co-solvents (sorbitol, urea) on the exchange rate was examined under pressure-assisted cold denaturation conditions, and the corresponding protection factors, P, were determined. The exchange kinetics upon heat treatment was found to be a two-step process with initial slow exchange followed by a fast one, showing residual protection in the slow-exchange state and P-factors in the random-coil-like range for the final temperature-denatured state. Addition of sorbitol (500 mM) led to an increase of P-factors for the pressure-assisted cold denatured state, but not for the heat-denatured state. The presence of 2 M urea resulted in a drastic decrease of the P-factors of the pressure-assisted cold denatured state. For both types of co-solvents, the effect they exert appears to be cooperative, i.e., no particular regions within the protein can be identified with significantly diverse changes of P-factors.

  1. Pressure-assisted cold denaturation of hen egg white lysozyme: the influence of co-solvents probed by hydrogen exchange nuclear magnetic resonance

    Directory of Open Access Journals (Sweden)

    K. Vogtt

    2005-08-01

    Full Text Available COSY proton nuclear magnetic resonance was used to measure the exchange rates of amide protons of hen egg white lysozyme (HEWL in the pressure-assisted cold-denatured state and in the heat-denatured state. After dissolving lysozyme in deuterium oxide buffer, labile protons exchange for deuterons in such a way that exposed protons are substituted rapidly, whereas "protected" protons within structured parts of the protein are substituted slowly. The exchange rates k obs were determined for HEWL under heat treatment (80ºC and under high pressure conditions at low temperature (3.75 kbar, -13ºC. Moreover, the influence of co-solvents (sorbitol, urea on the exchange rate was examined under pressure-assisted cold denaturation conditions, and the corresponding protection factors, P, were determined. The exchange kinetics upon heat treatment was found to be a two-step process with initial slow exchange followed by a fast one, showing residual protection in the slow-exchange state and P-factors in the random-coil-like range for the final temperature-denatured state. Addition of sorbitol (500 mM led to an increase of P-factors for the pressure-assisted cold denatured state, but not for the heat-denatured state. The presence of 2 M urea resulted in a drastic decrease of the P-factors of the pressure-assisted cold denatured state. For both types of co-solvents, the effect they exert appears to be cooperative, i.e., no particular regions within the protein can be identified with significantly diverse changes of P-factors.

  2. Vapor Phase Growth of High-Quality Bi-Te Compounds Using Elemental Bi and Te Sources: A Comparison Between High Vacuum and Atmospheric Pressure

    Science.gov (United States)

    Concepción, O.; Escobosa, A.; de Melo, O.

    2018-03-01

    Bismuth telluride (Bi2Te3), traditionally used in the industry as thermoelectric material, has deserved much attention recently due to its properties as a topological insulator, a kind of material that might have relevant applications in spintronics or quantum computing, among other innovative uses. The preparation of high-quality material has become a very important technological task. Here, we compare the preparation of Bi2Te3 by physical vapor transport from the evaporation of elemental Bi and Te sources, under either low pressure or atmospheric pressure. The layers were characterized by different techniques to evaluate its structural properties. As a result, it is concluded that, as a consequence of the different transport regimes, films grown at atmospheric pressure present better crystal quality.

  3. Method for estimating critical properties of heavy compounds suitable for cubic equations of state and its application to the prediction of vapor pressures

    DEFF Research Database (Denmark)

    Kontogeorgis, Georgios; Ioannis, Smirlis; Iakovos, Yakoumis

    1997-01-01

    S. The proposed scheme employs a recent group-contribution method (Constantinou et al. Fluid Phase Equilib. 1995, 103 (1), 11) for estimating the acentric factor. The two critical properties are estimated via a generalized correlation for the ratio T-c/P-c (with the van der Waals surface area) and the cubic Eo...... pressures for several nonpolar and slightly polar heavy compounds with very satisfactory results, essentially independent of the experimental point used. Furthermore, the method yields critical properties for heavy alkanes (N-c > 20) and other compounds which are in very good agreement with recent available......Cubic equations of state (EoS) are often used for correlating and predicting phase equilibria. Before extending any EoS to mixtures, reliable vapor-pressure prediction is essential. This requires experimental, if possible, critical temperatures T-c, pressures P-c, and acentric factor omega...

  4. ODC-Free Solvent Implementation Issues for Vulcanized Rubber and Bond Systems

    Science.gov (United States)

    Hodgson, James R.; McCool, Alex (Technical Monitor)

    2001-01-01

    Thiokol Propulsion has worked extensively to replace 1,1,1-trichloroethane (TCA) with ozone depleting chemicals (ODC)-free solvents for use in the manufacture of the Reusable Solid Rocket Motor (RSRM) for the Space Shuttle Program. As Thiokol has transitioned from sub-scale to full-scale testing and implementation of these new solvents, issues have been discovered which have required special attention. The original intent of Thiokol's solvent replacement strategy was to replace TCA with a single drop-in solvent for all equivalent applications. We have learned that a single candidate does not exist for replacing TCA. Solvent incompatibility with process materials has caused us to seek for niche solvents and/or processing changes that provide an ODC-free solution for special applications. This paper addresses some of the solvent incompatibilities, which have lead to processes changes and possible niche solvent usage. These incompatibilities were discovered during full-scale testing of ODC-free solvents and relate to vulcanized rubber and bond systems in the RSRM. Specifically, the following items are presented: (1) Cure effects of d-limonene based solvents on Silica Filled Ethylene Propylene Diene Monomer (SF-EPDM) rubber. During full-scale test operations, Thiokol discovered that d-limonene (terpene) based solvents inhibit the cure of EPDM rubber. Subsequent testing showed the same issue with Nitrile Butadiene Rubber (NBR). Also discussed are efforts to minimize uncured rubber exposure to solvents; and (2) Cured bond system sensitivity to ODC-free solvents. During full scale testing it was discovered that a natural rubber to steel vulcanized bond could degrade after prolonged exposure to ODC-free solvents. Follow on testing showed that low vapor pressure and residence time seemed to be most likely cause for failure.

  5. Aminosilicone solvent recovery methods and systems

    Science.gov (United States)

    Spiry, Irina Pavlovna; Perry, Robert James; Wood, Benjamin Rue; Singh, Surinder Prabhjot; Farnum, Rachel Lizabeth; Genovese, Sarah Elizabeth

    2018-02-13

    The present invention is directed to aminosilicone solvent recovery methods and systems. The methods and systems disclosed herein may be used to recover aminosilicone solvent from a carbon dioxide containing vapor stream, for example, a vapor stream that leaves an aminosilicone solvent desorber apparatus. The methods and systems of the invention utilize a first condensation process at a temperature from about 80.degree. C. to about 150.degree. C. and a second condensation process at a temperature from about 5.degree. C. to about 75.degree. C. The first condensation process yields recovered aminosilicone solvent. The second condensation process yields water.

  6. Low temperature carrier transport study of monolayer MoS{sub 2} field effect transistors prepared by chemical vapor deposition under an atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xinke, E-mail: xkliu@szu.edu.cn, E-mail: wujing026@gmail.com; He, Jiazhu; Tang, Dan; Lu, Youming; Zhu, Deliang; Liu, Wenjun; Cao, Peijiang; Han, Sun [College of Materials Science and Engineering, Shenzhen Engineering Laboratory for Advanced Technology of Ceramics, Nanshan District Key Lab for Biopolymer and Safety Evaluation, Shenzhen University, 3688 Nanhai Ave, Shenzhen 518060 (China); Liu, Qiang; Wen, Jiao; Yu, Wenjie [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, CAS, 865 Chang Ning Road, Shanghai 200050 (China); Liu, Wenjun [State Key Laboratory of ASIC and System, Department of Microelectronics, Fudan University, 220 Handan Road, Shanghai 200433 (China); Wu, Jing, E-mail: xkliu@szu.edu.cn, E-mail: wujing026@gmail.com [Department of Physics, National University of Singapore, 21 Lower Kent Ridge Road, 117576 Singapore (Singapore); He, Zhubing [Department of Materials Science and Engineering, South University of Science and Technology of China, 1088 Xueyuan Road, Shenzhen 518055 (China); Ang, Kah-Wee [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, 117583 Singapore (Singapore)

    2015-09-28

    Large size monolayer Molybdenum disulphide (MoS{sub 2}) was successfully grown by chemical vapor deposition method under an atmospheric pressure. The electrical transport properties of the fabricated back-gate monolayer MoS{sub 2} field effect transistors (FETs) were investigated under low temperatures; a peak field effect mobility of 59 cm{sup 2}V{sup −1}s{sup −1} was achieved. With the assist of Raman measurement under low temperature, this work identified the mobility limiting factor for the monolayer MoS{sub 2} FETs: homopolar phonon scattering under low temperature and electron-polar optical phonon scattering at room temperature.

  7. Microspectroscopic imaging of solution plasma: How do its physical properties and chemical species evolve in atmospheric-pressure water vapor bubbles?

    Science.gov (United States)

    Yui, Hiroharu; Banno, Motohiro

    2018-01-01

    In this article, we review the development of scientific instruments for obtaining information on the evolution of physical properties and chemical species of solution plasma (SP). When a pulsed high voltage is applied between electrodes immersed in an aqueous solution, SP is formed in water vapor bubbles transiently generated in the solution under atmospheric pressure. To clarify how SP emerges in water vapor bubbles and is sustained in solutions, an instrument with micrometer spatial resolution and nanosecond temporal resolution is required. To meet these requirements, a microscopic system with a custom-made optical discharge cell was newly developed, where the working distance between the SP and the microscopic objective lens was minimized. A hollow electrode equipped in the discharge cell also enabled us to control the chemical composition in water vapor bubbles. To study the spatial and temporal evolutions of chemical species in micrometer and nano- to microsecond regions, a streak camera with a spectrometer and a CCD detector with a time-gated electronic device were combined with the microscope system. The developed instrument is expected to contribute to providing a new means of developing new schemes for chemical reactions and material syntheses.

  8. Solvent jet desorption capillary photoionization-mass spectrometry.

    Science.gov (United States)

    Haapala, Markus; Teppo, Jaakko; Ollikainen, Elisa; Kiiski, Iiro; Vaikkinen, Anu; Kauppila, Tiina J; Kostiainen, Risto

    2015-03-17

    A new ambient mass spectrometry method, solvent jet desorption capillary photoionization (DCPI), is described. The method uses a solvent jet generated by a coaxial nebulizer operated at ambient conditions with nitrogen as nebulizer gas. The solvent jet is directed onto a sample surface, from which analytes are extracted into the solvent and ejected from the surface in secondary droplets formed in collisions between the jet and the sample surface. The secondary droplets are directed into the heated capillary photoionization (CPI) device, where the droplets are vaporized and the gaseous analytes are ionized by 10 eV photons generated by a vacuum ultraviolet (VUV) krypton discharge lamp. As the CPI device is directly connected to the extended capillary inlet of the MS, high ion transfer efficiency to the vacuum of MS is achieved. The solvent jet DCPI provides several advantages: high sensitivity for nonpolar and polar compounds with limit of detection down to low fmol levels, capability of analyzing small and large molecules, and good spatial resolution (250 μm). Two ionization mechanisms are involved in DCPI: atmospheric pressure photoionization, capable of ionizing polar and nonpolar compounds, and solvent assisted inlet ionization capable of ionizing larger molecules like peptides. The feasibility of DCPI was successfully tested in the analysis of polar and nonpolar compounds in sage leaves and chili pepper.

  9. Piezoelectric trace vapor calibrator

    International Nuclear Information System (INIS)

    Verkouteren, R. Michael; Gillen, Greg; Taylor, David W.

    2006-01-01

    The design and performance of a vapor generator for calibration and testing of trace chemical sensors are described. The device utilizes piezoelectric ink-jet nozzles to dispense and vaporize precisely known amounts of analyte solutions as monodisperse droplets onto a hot ceramic surface, where the generated vapors are mixed with air before exiting the device. Injected droplets are monitored by microscope with strobed illumination, and the reproducibility of droplet volumes is optimized by adjustment of piezoelectric wave form parameters. Complete vaporization of the droplets occurs only across a 10 deg. C window within the transition boiling regime of the solvent, and the minimum and maximum rates of trace analyte that may be injected and evaporated are determined by thermodynamic principles and empirical observations of droplet formation and stability. By varying solution concentrations, droplet injection rates, air flow, and the number of active nozzles, the system is designed to deliver--on demand--continuous vapor concentrations across more than six orders of magnitude (nominally 290 fg/l to 1.05 μg/l). Vapor pulses containing femtogram to microgram quantities of analyte may also be generated. Calibrated ranges of three explosive vapors at ng/l levels were generated by the device and directly measured by ion mobility spectrometry (IMS). These data demonstrate expected linear trends within the limited working range of the IMS detector and also exhibit subtle nonlinear behavior from the IMS measurement process

  10. Measurement and correlation of (vapor + liquid) equilibrium data for {α-pinene + p-cymene + (S)-(−)-limonene} ternary system at atmospheric pressure

    International Nuclear Information System (INIS)

    Sun, Lixia; Liao, Dankui; Yang, Zhengyu; Chen, Xiaopeng; Tong, Zhangfa

    2013-01-01

    Highlights: ► The VLE data of (α-pinene + p-cymene) and (α-pinene + p-cymene + (S)-(−)-limonene) at atmospheric pressure were measured. ► The VLE data of binary system were correlated by four activity coefficient models. ► The ternary VLE data were predicted from binary parameters of the Liebermann–Fried model. ► The constant G 123 E counters plotted on the Roozeboom diagrams. -- Abstract: (Vapor + liquid) equilibrium (VLE) data for binary system of (α-pinene + p-cymene) and ternary system of {α-pinene + p-cymene + (S)-(−)-limonene} were measured at 100.7 kPa using the modified Ellis equilibrium still. The VLE data are thermodynamically consistent. Parameters of the binary system for the four solution models — Liebermann–Fried, Wilson, NRTL, and UNIQUAC — were calculated by referencing least squares method to minimize an objective function based on the total pressure. The ternary system data were predicted with the parameters of Liebermann–Fried model obtained from the pertinent binary systems. The predicted bubble-point temperature and the vapor composition for the ternary system were in good agreement with the experimental results. Smooth representations of the results are used to construct constant excess Gibbs free energy contours on Roozeboom diagrams

  11. Effect of Al_2O_3 Nanoparticles Additives on the Density, Saturated Vapor Pressure, Surface Tension and Viscosity of Isopropyl Alcohol

    Science.gov (United States)

    Zhelezny, Vitaly; Geller, Vladimir; Semenyuk, Yury; Nikulin, Artem; Lukianov, Nikolai; Lozovsky, Taras; Shymchuk, Mykola

    2018-03-01

    This paper presents results of an experimental study of the density, saturated vapor pressure, surface tension and viscosity of Al_2O_3 nanoparticle colloidal solutions in isopropyl alcohol. Studies of the thermophysical properties of nanofluids were performed at various temperatures and concentrations of Al_2O_3 nanoparticles. The paper gives considerable attention to a turbidimetric analysis of the stability of nanofluid samples. Samples of nanofluids remained stable over the range of parameters of the experiments, ensuring the reliability of the thermophysical property data for the Al_2O_3 nanoparticle colloidal solutions in isopropyl alcohol. The studies show that the addition of Al_2O_3 nanoparticles leads to an increase of the density, saturated vapor pressure and viscosity, as well as a decrease for the surface tension of isopropyl alcohol. The information reported in this paper on the various thermophysical properties for the isopropyl alcohol/Al_2O_3 nanoparticle model system is useful for the development of thermodynamically consistent models for predicting properties of nanofluids and correct modeling of the heat exchange processes.

  12. Thermoeconomic analysis of an integrated multi-effect desalination thermal vapor compression (MED-TVC) system with a trigeneration system using triple-pressure HRSG

    Science.gov (United States)

    Ghaebi, Hadi; Abbaspour, Ghader

    2018-05-01

    In this research, thermoeconomic analysis of a multi-effect desalination thermal vapor compression (MED-TVC) system integrated with a trigeneration system with a gas turbine prime mover is carried out. The integrated system comprises of a compressor, a combustion chamber, a gas turbine, a triple-pressure (low, medium and high pressures) heat recovery steam generator (HRSG) system, an absorption chiller cycle (ACC), and a multi-effect desalination (MED) system. Low pressure steam produced in the HRSG is used to drive absorption chiller cycle, medium pressure is used in desalination system and high pressure superheated steam is used for heating purposes. For thermodynamic and thermoeconomic analysis of the proposed integrated system, Engineering Equation Solver (EES) is used by employing mass, energy, exergy, and cost balance equations for each component of system. The results of the modeling showed that with the new design, the exergy efficiency in the base design will increase to 57.5%. In addition, thermoeconomic analysis revealed that the net power, heating, fresh water and cooling have the highest production cost, respectively.

  13. A study on vapor explosions

    International Nuclear Information System (INIS)

    Takagi, N.; Shoji, M.

    1979-01-01

    An experimental study was carried out for vapor explosions of molten tin falling in water. For various initial metal temperatures and subcooling of water, transient pressure of the explosions, relative frequency of the explosions and the position where the explosions occur were measured in detail. The influence of ambient pressure was also investigated. From the results, it was concluded that the vapor explosion is closely related to the collapse of a vapor film around the molten metal. (author)

  14. Thermodynamic modeling of liquid–liquid phase change solvents for CO2 capture

    DEFF Research Database (Denmark)

    Waseem Arshad, Muhammad; von Solms, Nicolas; Thomsen, Kaj

    2016-01-01

    A thermodynamic model based on Extended UNIQUAC framework has been developed in this work for the de-mixing liquid–liquid phase change solvents, DEEA (2-(diethylamino)ethanol) and MAPA (3-(methylamino)propylamine). Parameter estimation was performed for two ternary systems, H2O-DEEA-CO2 and H2O......-MAPA-CO2, and a quaternary system, H2O-DEEA-MAPA-CO2 (phase change system), by using different types of experimental data (equilibrium and thermal) consisting of pure amine vapor pressure, vapor-liquid equilibrium, solid-liquid equilibrium, liquid–liquid equilibrium, excess enthalpy, and heat of absorption...

  15. Experimental vapor pressures (from 1 Pa to 100 kPa) of six saturated Fatty Acid Methyl Esters (FAMEs): Methyl hexanoate, methyl octanoate, methyl decanoate, methyl dodecanoate, methyl tetradecanoate and methyl hexadecanoate

    International Nuclear Information System (INIS)

    Sahraoui, Lakhdar; Khimeche, Kamel; Dahmani, Abdallah; Mokbel, Ilham; Jose, Jacques

    2016-01-01

    Highlight: • Vapor-liquid equilibria, Enthalpy of Vaporization, saturated Fatty Acid Methyl Ester. - Abstract: Vapor pressures of six saturated Fatty Acid Methyl Esters (FAMEs), methyl hexanoate (or methyl caproate), methyl octanoate (or methyl caprylate), Methyl decanoate (or methyl caprate), methyl dodecanoate (or methyl laurate), methyl tetradecanoate (or methyl myristate), and methyl hexadecanoate (or methyl palmitate) were measured from 1 Pa to 100 kPa and at temperature range between 262 and 453 K using a static apparatus. The experimental data (P-T) were compared with the available literature data.

  16. Direct delamination of graphite ore into defect-free graphene using a biphasic solvent system under pressurized ultrasound

    Czech Academy of Sciences Publication Activity Database

    Beneš, Hynek; Donato, R. K.; Ecorchard, P.; Popelková, Daniela; Pavlová, Eva; Schelonka, D.; Pop-Georgievski, Ognen; Schrekker, H. S.; Štengl, V.

    2016-01-01

    Roč. 6, č. 8 (2016), s. 6008-6015 ISSN 2046-2069 R&D Projects: GA ČR(CZ) GA14-05146S Institutional support: RVO:61389013 Keywords : graphite ore * graphene * high-pressure ultrasound Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.108, year: 2016

  17. Direct delamination of graphite ore into defect-free graphene using a biphasic solvent system under pressurized ultrasound.

    Czech Academy of Sciences Publication Activity Database

    Beneš, H.; Donato, R. K.; Ecorchard, Petra; Popelková, Daniela; Pavlová, E.; Schelonka, Darina; Pop-Georgievski, O.; Schrekker, H. S.; Štengl, Václav

    2016-01-01

    Roč. 6, č. 8 (2016), s. 6008-6015 ISSN 2046-2069 R&D Projects: GA ČR(CZ) GA14-05146S Institutional support: RVO:61388980 Keywords : graphite ore * graphene * high-pressure ultrasound Subject RIV: CA - Inorganic Chemistry Impact factor: 3.108, year: 2016

  18. Solvent extraction of gold using ionic liquid based process

    Science.gov (United States)

    Makertihartha, I. G. B. N.; Zunita, Megawati; Rizki, Z.; Dharmawijaya, P. T.

    2017-01-01

    In decades, many research and mineral processing industries are using solvent extraction technology for metal ions separation. Solvent extraction technique has been used for the purification of precious metals such as Au and Pd, and base metals such as Cu, Zn and Cd. This process uses organic compounds as solvent. Organic solvents have some undesired properties i.e. toxic, volatile, excessive used, flammable, difficult to recycle, low reusability, low Au recovery, together with the problems related to the disposal of spent extractants and diluents, even the costs associated with these processes are relatively expensive. Therefore, a lot of research have boosted into the development of safe and environmentally friendly process for Au separation. Ionic liquids (ILs) are the potential alternative for gold extraction because they possess several desirable properties, such as a the ability to expanse temperature process up to 300°C, good solvent properties for a wide range of metal ions, high selectivity, low vapor pressures, stability up to 200°C, easy preparation, environmentally friendly (commonly called as "green solvent"), and relatively low cost. This review paper is focused in investigate of some ILs that have the potentials as solvent in extraction of Au from mineral/metal alloy at various conditions (pH, temperature, and pressure). Performances of ILs extraction of Au are studied in depth, i.e. structural relationship of ILs with capability to separate Au from metal ions aggregate. Optimal extraction conditon in order to gain high percent of Au in mineral processing is also investigated.

  19. The electrical properties of low pressure chemical vapor deposition Ga doped ZnO thin films depending on chemical bonding configuration

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Hanearl [School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Kim, Doyoung [School of Electrical and Electronic Engineering, Ulsan College, 57 Daehak-ro, Nam-gu, Ulsan 680-749 (Korea, Republic of); Kim, Hyungjun, E-mail: hyungjun@yonsei.ac.kr [School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749 (Korea, Republic of)

    2014-04-01

    Highlights: • Undoped and Ga doped ZnO thin films were deposited using DEZ and TMGa. • Effects of Ga doping using TMGa in Ga doped ZnO were investigated. • Degraded properties from excessive doping were analyzed using chemical bondings. - Abstract: The electrical and chemical properties of low pressure chemical vapor deposition (LP-CVD) Ga doped ZnO (ZnO:Ga) films were systematically investigated using Hall measurement and X-ray photoemission spectroscopy (XPS). Diethylzinc (DEZ) and O{sub 2} gas were used as precursor and reactant gas, respectively, and trimethyl gallium (TMGa) was used as a Ga doping source. Initially, the electrical properties of undoped LP-CVD ZnO films depending on the partial pressure of DEZ and O{sub 2} ratio were investigated using X-ray diffraction (XRD) by changing partial pressure of DEZ from 40 to 140 mTorr and that of O{sub 2} from 40 to 80 mTorr. The resistivity was reduced by Ga doping from 7.24 × 10{sup −3} Ω cm for undoped ZnO to 2.05 × 10{sup −3} Ω cm for Ga doped ZnO at the TMG pressure of 8 mTorr. The change of electric properties of Ga doped ZnO with varying the amount of Ga dopants was systematically discussed based on the structural crystallinity and chemical bonding configuration, analyzed by XRD and XPS, respectively.

  20. Extraction of Kinetic Parameters for the Chemical Vapor Deposition of Polycrystalline Silicon at Medium and Low Pressures

    NARCIS (Netherlands)

    Holleman, J.; Verweij, J.F.; Verweij, Jan F.

    1993-01-01

    The deposition of silicon (Si) from silane (SiH4) was studied in the silane pressure range from 0.5 to 100 Pa (0.005 to1 mbar) and total pressure range from 10 to 1000 Pa using N2 or He as carrier gases. The two reaction paths, namely,heterogeneous and homogeneous decomposition could be separated by

  1. CO2-assisted high pressure homogenization: a solvent-free process for polymeric microspheres and drug-polymer composites.

    Science.gov (United States)

    Kluge, Johannes; Mazzotti, Marco

    2012-10-15

    The study explores the enabling role of near-critical CO(2) as a reversible plasticizer in the high pressure homogenization of polymer particles, aiming at their comminution as well as at the formation of drug-polymer composites. First, the effect of near-critical CO(2) on the homogenization of aqueous suspensions of poly lactic-co-glycolic acid (PLGA) was investigated. Applying a pressure drop of 900 bar and up to 150 passes across the homogenizer, it was found that particles processed in the presence of CO(2) were generally of microspherical morphology and at all times significantly smaller than those obtained in the absence of a plasticizer. The smallest particles, exhibiting a median x(50) of 1.3 μm, were obtained by adding a small quantity of ethyl acetate, which exerts on PLGA an additional plasticizing effect during the homogenization step. Further, the study concerns the possibility of forming drug-polymer composites through simultaneous high pressure homogenization of the two relevant solids, and particularly the effect of near-critical CO(2) on this process. Therefore, PLGA was homogenized together with crystalline S-ketoprofen (S-KET), a non-steroidal anti-inflammatory drug, at a drug to polymer ratio of 1:10, a pressure drop of 900 bar and up to 150 passes across the homogenizer. When the process was carried out in the presence of CO(2), an impregnation efficiency of 91% has been reached, corresponding to 8.3 wt.% of S-KET in PLGA; moreover, composite particles were of microspherical morphology and significantly smaller than those obtained in the absence of CO(2). The formation of drug-polymer composites through simultaneous homogenization of the two materials is thus greatly enhanced by the presence of CO(2), which increases the efficiency for both homogenization and impregnation. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Green solvents and technologies for oil extraction from oilseeds

    OpenAIRE

    Kumar, S. P. Jeevan; Prasad, S. Rajendra; Banerjee, Rintu; Agarwal, Dinesh K.; Kulkarni, Kalyani S.; Ramesh, K. V.

    2017-01-01

    Oilseeds are crucial for the nutritional security of the global population. The conventional technology used for oil extraction from oilseeds is by solvent extraction. In solvent extraction, n-hexane is used as a solvent for its attributes such as simple recovery, non-polar nature, low latent heat of vaporization (330?kJ/kg) and high selectivity to solvents. However, usage of hexane as a solvent has lead to several repercussions such as air pollution, toxicity and harmfulness that prompted to...

  3. Residual stress in thick low-pressure chemical-vapor deposited polycrystalline SiC coatings on Si substrates

    Science.gov (United States)

    Choi, D.; Shinavski, R. J.; Steffier, W. S.; Spearing, S. M.

    2005-04-01

    Residual stress in thick coatings of polycrystalline chemical-vapor deposited SiC on Si substrates is a key variable that must be controlled if SiC is to be used in microelectromechanical systems. Studies have been conducted to characterize the residual stress level as a function of deposition temperature, Si wafer and SiC coating thickness, and the ratios of methyltrichlorosilane to hydrogen and hydrogen chloride. Wafer curvature was used to monitor residual stress in combination with a laminated plate analysis. Compressive intrinsic (growth) stresses were measured with magnitudes in the range of 200-300MPa; however, these can be balanced with the tensile stress due to the thermal-expansion mismatch to leave near-zero stress at room temperature. The magnitude of the compressive intrinsic stress is consistent with previously reported values of surface stress in combination with the competition between grain-boundary energy and elastic strain energy.

  4. Deasphalting solvents

    International Nuclear Information System (INIS)

    Carrillo, J. A; Caceres, J; Vela, G; Bueno, H

    1996-01-01

    This paper describes how the deasphalted oil (DMO) or demetalized oil (DMO) quality (CCR, Ni, V end asphaltenes contents) changes with: DAO or DMO yield, solvent/feed ratio, type of vacuum reside (from paraffinic to blends with vis breaking bottoms), extraction temperature and extraction solvent (propane, propylene, n-butane and I butane)

  5. PHASE BEHAVIOR OF LIGHT GASES IN HYDROCARBON AND AQUEOUS SOLVENTS

    Energy Technology Data Exchange (ETDEWEB)

    KHALED A.M. GASEM; ROBERT L. ROBINSON, JR.

    1998-08-31

    Under previous support from the Department of Energy, an experimental facility has been established and operated to measure valuable vapor-liquid equilibrium data for systems of interest in the production and processing of coal fluids. To facilitate the development and testing of models for prediction of the phase behavior for such systems, we have acquired substantial amounts of data on the equilibrium phase compositions for binary mixtures of heavy hydrocarbon solvents with a variety of supercritical solutes, including hydrogen, methane, ethane, carbon monoxide, and carbon dioxide. The present project focuses on measuring the phase behavior of light gases and water in Fischer-Tropsch (F-T) type solvents at conditions encountered in indirect liquefaction processes and evaluating and developing theoretically-based correlating frameworks to predict the phase behavior of such systems. Specific goals of the proposed work include (a) developing a state-of-the-art experimental facility to permit highly accurate measurements of equilibrium phase compositions (solubilities) of challenging F-T systems, (b) measuring these properties for systematically-selected binary, ternary and molten F-T wax mixtures to provide critically needed input data for correlation development, (c) developing and testing models suitable for describing the phase behavior of such mixtures, and (d) presenting the modeling results in generalized, practical formats suitable for use in process engineering calculations. During the present period, the Park-Gasem-Robinson (PGR) equation of state (EOS) has been modified to improve its volumetric and equilibrium predictions. Specifically, the attractive term of the PGR equation was modified to enhance the flexibility of the model, and a new expression was developed for the temperature dependence of the attractive term in this segment-segment interaction model. The predictive capability of the modified PGR EOS for vapor pressure, and saturated liquid and

  6. Vapor pressures, osmotic and activity coefficients for (LiBr + acetonitrile) between the temperatures (298.15 and 343.15) K

    Energy Technology Data Exchange (ETDEWEB)

    Nasirzadeh, Karamat E-mail: karamat.nasirzadeh@chemie.uni-regensburg.de; Neueder, Roland; Kunz, Werner

    2004-06-01

    Precise vapor pressure data for pure acetonitrile and (LiBr + acetonitrile) are given for temperatures ranging from T=(298.15 to 343.15) K. The molality range is from m=(0.0579 to 0.8298) mol {center_dot} kg{sup -1}. The osmotic coefficients are calculated by taking into account the second virial coefficient of acetonitrile. The parameters of the extended Pitzer ion interaction model of Archer and the mole fraction-based thermodynamic model of Clegg-Pitzer are evaluated. These models accurately reproduce the available osmotic coefficients. The parameters of the extended Pitzer ion interaction model of Archer are used to calculate the mean molal activity coefficients.

  7. (Vapor + liquid) equilibrium data for (carbon dioxide + 1,1-difluoroethane) system at temperatures from (258 to 343) K and pressures up to about 8 MPa

    International Nuclear Information System (INIS)

    Madani, Hakim; Valtz, Alain; Coquelet, Christophe; Meniai, Abdeslam Hassen; Richon, Dominique

    2008-01-01

    Accurate thermo-physical data are of utmost interest for the development of new efficient refrigeration systems. Carbon dioxide (R744) and 1,1-difluoroethane (R152a) are addressed here. Isothermal (vapor + liquid) equilibrium data are reported herein for (R744 + R152a) binary system in the (258-343) K temperature range and in the (0.14 to 7.65) MPa pressure range. A reliable 'static-analytic' method taking advantage of two online ROLSI TM micro capillary samplers is used for all thermodynamic measurements. The data are correlated using our in-house ThermoSoft thermodynamic model using the Peng-Robinson equation of state, the Mathias-Copeman alpha function, the Wong-Sandler mixing rules, and the NRTL model

  8. Stabilization and operation of porous silicon photonic structures from near-ultraviolet to near-infrared using high-pressure water vapor annealing

    International Nuclear Information System (INIS)

    Gelloz, Bernard; Koshida, Nobuyoshi

    2010-01-01

    The effects of high-pressure water vapor annealing (HWA), electrochemical oxidation, and substrate resistivity on the properties of porous silicon Bragg mirrors and photoluminescent cavities have been investigated. The photonic structures treated by HWA show very good stability upon ageing in air whereas as-formed structures exhibit significant drifts in their optical properties. Using HWA with lightly doped porous silicon, the structure transparency is enhanced sufficiently to enable the possible photonic operation in the near-ultraviolet. However, the index contrast achievable with these structures is very low in the visible and near-infrared. Useful index contrasts in this range can be achieved with either lightly doped porous silicon treated by electrochemical oxidation and HWA or heavily doped porous silicon treated by HWA.

  9. Generation of InN nanocrystals in organic solution through laser ablation of high pressure chemical vapor deposition-grown InN thin film

    International Nuclear Information System (INIS)

    Alkis, Sabri; Alevli, Mustafa; Burzhuev, Salamat; Vural, Hüseyin Avni; Okyay, Ali Kemal; Ortaç, Bülend

    2012-01-01

    We report the synthesis of colloidal InN nanocrystals (InN-NCs) in organic solution through nanosecond pulsed laser ablation of high pressure chemical vapor deposition-grown InN thin film on GaN/sapphire template substrate. The size, the structural, the optical, and the chemical characteristics of InN-NCs demonstrate that the colloidal InN crystalline nanostructures in ethanol are synthesized with spherical shape within 5.9–25.3, 5.45–34.8, 3.24–36 nm particle-size distributions, increasing the pulse energy value. The colloidal InN-NCs solutions present strong absorption edge tailoring from NIR region to UV region.

  10. Effect of Growth Pressure on Epitaxial Graphene Grown on 4H-SiC Substrates by Using Ethene Chemical Vapor Deposition

    Directory of Open Access Journals (Sweden)

    Shuxian Cai

    2015-08-01

    Full Text Available The Si(0001 face and C(000-1 face dependences on growth pressure of epitaxial graphene (EG grown on 4H-SiC substrates by ethene chemical vapor deposition (CVD was studied using atomic force microscopy (AFM and micro-Raman spectroscopy (μ-Raman. AFM revealed that EGs on Si-faced substrates had clear stepped morphologies due to surface step bunching. However, This EG formation did not occur on C-faced substrates. It was shown by μ-Raman that the properties of EG on both polar faces were different. EGs on Si-faced substrates were relatively thinner and more uniform than on C-faced substrates at low growth pressure. On the other hand, D band related defects always appeared in EGs on Si-faced substrates, but they did not appear in EG on C-faced substrate at an appropriate growth pressure. This was due to the μ-Raman covering the step edges when measurements were performed on Si-faced substrates. The results of this study are useful for optimized growth of EG on polar surfaces of SiC substrates.

  11. Effects of temperature, pressure and pure copper added to source material on the CuGaTe{sub 2} deposition using close spaced vapor transport technique

    Energy Technology Data Exchange (ETDEWEB)

    Abounachit, O. [LP2M2E, Faculté des Sciences et Techniques, Université Cadi Ayyad, Gueliz, BP 549 , Marrakech, Maroc (Morocco); Chehouani, H., E-mail: chehouani@hotmail.fr [LP2M2E, Faculté des Sciences et Techniques, Université Cadi Ayyad, Gueliz, BP 549 , Marrakech, Maroc (Morocco); Djessas, K. [CNRS-PROMES Tecnosud, Rambla de la Thermodynamique, 66100 Perpignan (France)

    2013-07-01

    The quality of CuGaTe{sub 2} (CGT) thin films elaborated by close spaced vapor transport technique has been studied as a function of the source temperature (T{sub S}), iodine pressure (P{sub I2}) and the amount (X{sub Cu}) of pure copper added to the stoichiometric starting material. A thermodynamic model was developed for the Cu–Ga–Te–I system to describe the CGT deposition. The model predicts the solid phase composition with possible impurities for the operating conditions previously mentioned. The conditions of stoichiometric and near-stoichiometric deposition were determined. The value of T{sub S} must range from 450 to 550 °C for P{sub I2} varying between 0.2 and 7 kPa. Adding an amount up to 10% of pure copper to the starting material improves the quality of the deposit layers and lowers the operating interval temperature to 325–550 °C. These optimal conditions were tested experimentally at 480 °C and 500 °C. The X-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy have proved that the addition of pure copper to the stoichiometric source material can be considered as a supplementary operating parameter to improve the quality of CGT thin films. - Highlights: • The stoichiometric CuGaTe{sub 2} (CGT) has been deposited by close spaced vapor transport. • The Cu–Ga–Te–I system has been studied theoretically by minimizing the Gibbs energy. • The quality of thin films has been improved by pure copper added to the source CGT. • The temperature, pressure and the amount of copper added to grow CGT are determined. • The thermodynamic predictions are in good agreement with experimental results.

  12. Pressure (Or No Royal Road)

    Science.gov (United States)

    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)

  13. Mechanistic study on lowering the sensitivity of positive atmospheric pressure photoionization mass spectrometric analyses: size-dependent reactivity of solvent clusters.

    Science.gov (United States)

    Ahmed, Arif; Choi, Cheol Ho; Kim, Sunghwan

    2015-11-15

    Understanding the mechanism of atmospheric pressure photoionization (APPI) is important for studies employing APPI liquid chromatography/mass spectrometry (LC/MS). In this study, the APPI mechanism for polyaromatic hydrocarbon (PAH) compounds dissolved in toluene and methanol or water mixture was investigated by use of MS analysis and quantum mechanical simulation. In particular, four different mechanisms that could contribute to the signal reduction were considered based on a combination of MS data and quantum mechanical calculations. The APPI mechanism is clarified by combining MS data and density functional theory (DFT) calculations. To obtain MS data, a positive-mode (+) APPI Q Exactive Orbitrap mass spectrometer was used to analyze each solution. DFT calculations were performed using the general atomic and molecular electronic structure system (GAMESS). The experimental results indicated that methanol significantly reduced the signal in (+) APPI, but no significative signal reduction was observed when water was used as a co-solvent with toluene. The signal reduction is more significant especially for molecular ions than for protonated ions. Therefore, important information about the mechanism of methanol-induced signal reduction in (+) APPI-MS can be gained due its negative impact on APPI efficiency. The size-dependent reactivity of methanol clusters ((CH3 OH)n , n = 1-8) is an important factor in determining the sensitivity of (+) APPI-MS analyses. Clusters can compete with toluene radical ions for electrons. The reactivity increases as the sizes of the methanol clusters increase and this effect can be caused by the size-dependent ionization energy of the solvent clusters. The resulting increase in cluster reactivity explains the flow rate and temperature-dependent signal reduction observed in the analytes. Based on the results presented here, minimizing the sizes of methanol clusters can improve the sensitivity of LC/(+)-APPI-MS. Copyright © 2015 John

  14. Substantial rate enhancements of the esterification reaction of phthalic anhydride with methanol at high pressure and using supercritical CO2 as a co-solvent in a glass microreactor

    NARCIS (Netherlands)

    Benito-Lopez, F.; Tiggelaar, Roald M.; Salblut, K.; Huskens, Jurriaan; Egberink, Richard J.M.; Reinhoudt, David; Gardeniers, Johannes G.E.; Verboom, Willem

    2007-01-01

    The esterification reaction of phthalic anhydride with methanol was performed at different temperatures in a continuous flow glass microreactor at pressures up to 110 bar and using supercritical CO2 as a co-solvent. The design is such that supercritical CO2 can be generated inside the microreactor.

  15. Solvent substitution

    International Nuclear Information System (INIS)

    1990-01-01

    The DOE Environmental Restoration and Waste Management Office of Technology Development and the Air Force Engineering and Services Center convened the First Annual International Workshop on Solvent Substitution on December 4--7, 1990. The primary objectives of this joint effort were to share information and ideas among attendees in order to enhance the development and implementation of required new technologies for the elimination of pollutants associated with industrial use of hazardous and toxic solvents; and to aid in accelerating collaborative efforts and technology transfer between government and industry for solvent substitution. There were workshop sessions focusing on Alternative Technologies, Alternative Solvents, Recovery/Recycling, Low VOC Materials and Treatment for Environmentally Safe Disposal. The 35 invited papers presented covered a wide range of solvent substitution activities including: hardware and weapons production and maintenance, paint stripping, coating applications, printed circuit boards, metal cleaning, metal finishing, manufacturing, compliance monitoring and process control monitoring. This publication includes the majority of these presentations. In addition, in order to further facilitate information exchange and technology transfer, the US Air Force and DOE solicited additional papers under a general ''Call for Papers.'' These papers, which underwent review and final selection by a peer review committee, are also included in this combined Proceedings/Compendium. For those involved in handling, using or managing hazardous and toxic solvents, this document should prove to be a valuable resource, providing the most up-to-date information on current technologies and practices in solvent substitution. Individual papers are abstracted separated

  16. Solvent substitution

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    The DOE Environmental Restoration and Waste Management Office of Technology Development and the Air Force Engineering and Services Center convened the First Annual International Workshop on Solvent Substitution on December 4--7, 1990. The primary objectives of this joint effort were to share information and ideas among attendees in order to enhance the development and implementation of required new technologies for the elimination of pollutants associated with industrial use of hazardous and toxic solvents; and to aid in accelerating collaborative efforts and technology transfer between government and industry for solvent substitution. There were workshop sessions focusing on Alternative Technologies, Alternative Solvents, Recovery/Recycling, Low VOC Materials and Treatment for Environmentally Safe Disposal. The 35 invited papers presented covered a wide range of solvent substitution activities including: hardware and weapons production and maintenance, paint stripping, coating applications, printed circuit boards, metal cleaning, metal finishing, manufacturing, compliance monitoring and process control monitoring. This publication includes the majority of these presentations. In addition, in order to further facilitate information exchange and technology transfer, the US Air Force and DOE solicited additional papers under a general Call for Papers.'' These papers, which underwent review and final selection by a peer review committee, are also included in this combined Proceedings/Compendium. For those involved in handling, using or managing hazardous and toxic solvents, this document should prove to be a valuable resource, providing the most up-to-date information on current technologies and practices in solvent substitution. Individual papers are abstracted separated.

  17. Evaluation of final vapor pressures in the loss of flow accident in an irradiation device of a pool reactor core

    International Nuclear Information System (INIS)

    Verri, A.

    1987-01-01

    The reliability feature, are described for a device containing samples, at a temperatures of 300 grade centigrades, in a reactor core for a long time. After an examination of the maximum accident event, the maximum vapour pressure originated by the inlet of reactor cooling water into the experimental device, is evaluated

  18. Investigation of low pressure ES-SAGD

    Energy Technology Data Exchange (ETDEWEB)

    Ivory, J.; Zheng, R.; Nasr, T.; Deng, X.; Beaulieu, G.; Heck, G. [Alberta Research Council, Edmonton, AB (Canada)

    2008-10-15

    This paper described a scaled model experiment conducted to investigate the effectiveness of expanding solvent steam assisted gravity drainage (ES-SAGD) processes at low pressures. Lower SAGD pressures typically result in reduced oil production as a result of correspondingly lower steam temperatures. However, lower pressures may also result in a reduced steam to oil ratio (SOR) and a higher vaporization heat. Steam was injected into an injection well at 33 cm{sup 3} per minute and in a production well at 31 cm{sup 3} per minute. Steam and solvents were then co-injected into the injection well at a temperature of 206 degrees C. The experiment was history-matched and a parametric analysis was conducted using a simulation tool. The 2-D and 3-D field-scale simulations investigated the impact of operating pressures, injection rates; sub-cool; oil and gas phase diffusion and dispersion; live oil versus dead oil performance; and the use of drawdown when oil rates declined. Low pressure ES-SAGD was then compared with low-pressure SAGD. Results of the study suggested that production pressures, sub-cool and solvent concentrations are important parameters in ES-SAGD processes. At 1500 kPa production pressure and 10 degrees C sub-cool, the co-injection of solvent with steam increased average oil rates by 15 per cent more than the SAGD process. SOR was also reduced. 6 refs., 8 tabs., 20 figs.

  19. Determination of Wastewater Compounds in Sediment and Soil by Pressurized Solvent Extraction, Solid-Phase Extraction, and Capillary-Column Gas Chromatography/Mass Spectrometry

    Science.gov (United States)

    Burkhardt, Mark R.; Zaugg, Steven D.; Smith, Steven G.; ReVello, Rhiannon C.

    2006-01-01

    A method for the determination of 61 compounds in environmental sediment and soil samples is described. The method was developed in response to increasing concern over the effects of endocrine-disrupting chemicals in wastewater and wastewater-impacted sediment on aquatic organisms. This method also may be used to evaluate the effects of combined sanitary and storm-sewer overflow on the water and sediment quality of urban streams. Method development focused on the determination of compounds that were chosen on the basis of their endocrine-disrupting potential or toxicity. These compounds include the alkylphenol ethoxylate nonionic surfactants and their degradates, food additives, fragrances, antioxidants, flame retardants, plasticizers, industrial solvents, disinfectants, fecal sterols, polycyclic aromatic hydrocarbons, and high-use domestic pesticides. Sediment and soil samples are extracted using a pressurized solvent extraction system. The compounds of interest are extracted from interfering matrix components by high-pressure water/isopropyl alcohol extraction. The compounds were isolated using disposable solid-phase extraction (SPE) cartridges containing chemically modified polystyrene-divinylbenzene resin. The cartridges were dried with nitrogen gas, and then sorbed compounds were eluted with methylene chloride (80 percent)-diethyl ether (20 percent) through Florisil/sodium sulfate SPE cartridge, and then determined by capillary-column gas chromatography/mass spectrometry. Recoveries in reagent-sand samples fortified at 4 to 72 micrograms averaged 76 percent ?13 percent relative standard deviation for all method compounds. Initial method reporting levels for single-component compounds ranged from 50 to 500 micrograms per kilogram. The concentrations of 20 out of 61 compounds initially will be reported as estimated with the 'E' remark code for one of three reasons: (1) unacceptably low-biased recovery (less than 60 percent) or highly variable method performance

  20. Vapor Pressure Plus: An Experiment for Studying Phase Equilibria in Water, with Observation of Supercooling, Spontaneous Freezing, and the Triple Point

    Science.gov (United States)

    Tellinghuisen, Joel

    2010-01-01

    Liquid-vapor, solid-vapor, and solid-liquid-vapor equilibria are studied for the pure substance water, using modern equipment that includes specially fabricated glass cells. Samples are evaporatively frozen initially, during which they typically supercool to -5 to -10 [degrees]C before spontaneously freezing. Vacuum pumping lowers the temperature…

  1. TiO{sub 2} Processed by pressurized hot solvents as a novel photocatalyst for photocatalytic reduction of carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Reli, Martin, E-mail: martin.reli@vsb.cz [Institute of Environmental Technology, VŠB-TU Ostrava, 17. listopadu 15/2172, 708 33 Ostrava (Czech Republic); Kobielusz, Marcin [Faculty of Chemistry, Jagiellonian University in Kraków, ul. Ingardena 3, 30-060 Kraków (Poland); Matějová, Lenka [Institute of Environmental Technology, VŠB-TU Ostrava, 17. listopadu 15/2172, 708 33 Ostrava (Czech Republic); Daniš, Stanislav [Department of Condensed Matter Physics, Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 5, 121 16 Prague 2 (Czech Republic); Macyk, Wojciech [Centre ENET, VŠB-TU Ostrava, 17. listopadu 15/2172, 708 33 Ostrava (Czech Republic); Obalová, Lucie [Institute of Environmental Technology, VŠB-TU Ostrava, 17. listopadu 15/2172, 708 33 Ostrava (Czech Republic); Kuśtrowski, Piotr; Rokicińska, Anna [Faculty of Chemistry, Jagiellonian University in Kraków, ul. Ingardena 3, 30-060 Kraków (Poland); Kočí, Kamila [Institute of Environmental Technology, VŠB-TU Ostrava, 17. listopadu 15/2172, 708 33 Ostrava (Czech Republic); Centre ENET, VŠB-TU Ostrava, 17. listopadu 15/2172, 708 33 Ostrava (Czech Republic)

    2017-01-01

    Highlights: • Synthesis of anatase-brookite TiO{sub 2} photocatalysts has been described. • The materials photocatalyze carbon dioxide reduction to methane. • The photoactivity of the synthesized composites has been compared with the activity of anatase-rutile material (P25). • The influence of electronic structure on photocatalytic activity has been discussed. - Abstract: Anatase-brookite TiO{sub 2} photocatalysts were prepared by the sol-gel process controlled within reverse micelles and processing by pressurized hot solvents–water/methanol/water (TiO{sub 2}(M)) and water/ethanol/water (TiO{sub 2}(E)), as an unconventional alternative to common calcination. The main goal of this work was to prepare anatase-brookite mixtures by processing by two different alcohols (methanol and ethanol) and evaluate the influence of the alcohol on the photocatalytic activity. Prepared photocatalysts were characterized by organic elemental analysis, nitrogen physisorption, XRD, UV–vis, photoelectrochemical and spectroelectrochemical measurements and XPS. The prepared photocatalysts efficiency was tested on the photocatalytic reduction of carbon dioxide and compared with commercial TiO{sub 2} Evonik P25. Both prepared nanocomposites were more efficient towards methane production but Evonik P25 was the most efficient towards hydrogen generated through water splitting. The higher performance of anatase-brookite mixture towards methane production can be explained by (i) a higher photocatalytic activity of brookite than rutile; (ii) a large surface area of anatase-brookite composites enabling better carbon dioxide adsorption; (iii) the photoinduced electron transfer from the brookite conduction band to the anatase conduction band. On the other hand, a higher production of hydrogen in the presence of Evonik P25 is caused by a better charge separation in anatase-rutile than anatase-brookite phase compositions. TiO{sub 2}(M) appeared more active than TiO{sub 2}(E) in the

  2. COMPARISON OF THE OCTANOL-AIR PARTITION COEFFICIENT AND LIQUID-PHASE VAPOR PRESSURE AS DESCRIPTORS FOR PARTICLE/GAS PARTITIONING USING LABORATORY AND FIELD DATA FOR PCBS AND PCNS

    Science.gov (United States)

    The conventional Junge-Pankow adsorption model uses the sub-cooled liquid vapor pressure (pLo) as a correlation parameter for gas/particle interactions. An alternative is the octanol-air partition coefficient (Koa) absorption model. Log-log plots of the particle-gas partition c...

  3. Investigation of deposition characteristics and properties of high-rate deposited silicon nitride films prepared by atmospheric pressure plasma chemical vapor deposition

    International Nuclear Information System (INIS)

    Kakiuchi, H.; Nakahama, Y.; Ohmi, H.; Yasutake, K.; Yoshii, K.; Mori, Y.

    2005-01-01

    Silicon nitride (SiN x ) films have been prepared at extremely high deposition rates by the atmospheric pressure plasma chemical vapor deposition (AP-PCVD) technique on Si(001) wafers from gas mixtures containing He, H 2 , SiH 4 and N 2 or NH 3 . A 150 MHz very high frequency (VHF) power supply was used to generate high-density radicals in the atmospheric pressure plasma. Deposition rate, composition and morphology of the SiN x films prepared with various deposition parameters were studied by scanning electron microscopy and Auger electron spectroscopy. Fourier transformation infrared (FTIR) absorption spectroscopy was also used to characterize the structure and the chemical bonding configurations of the films. Furthermore, etching rate with buffered hydrofluoric acid (BHF) solution, refractive index and capacitance-voltage (C-V) characteristics were measured to evaluate the dielectric properties of the films. It was found that effective passivation of dangling bonds and elimination of excessive hydrogen atoms at the film-growing surface seemed to be the most important factor to form SiN x film with a dense Si-N network. The C-V curve of the optimized film showed good interface properties, although further improvement was necessary for use in the industrial metal-insulator-semiconductor (MIS) applications

  4. High-pressure vapor-phase hydrodeoxygenation of lignin-derived oxygenates to hydrocarbons by a PtMo bimetallic catalyst: Product selectivity, reaction pathway, and structural characterization

    Energy Technology Data Exchange (ETDEWEB)

    Yohe, Sara L.; Choudhari, Harshavardhan J.; Mehta, Dhairya D.; Dietrich, Paul J.; Detwiler, Michael D.; Akatay, Cem M.; Stach, Eric A.; Miller, Jeffrey T.; Delgass, W. Nicholas; Agrawal, Rakesh; Ribeiro, Fabio H.

    2016-12-01

    High-pressure, vapor-phase, hydrodeoxygenation (HDO) reactions of dihydroeugenol (2-methoxy-4-propylphenol), as well as other phenolic, lignin-derived compounds, were investigated over a bimetallic platinum and molybdenum catalyst supported on multi-walled carbon nanotubes (5%Pt2.5%Mo/MWCNT). Hydrocarbons were obtained in 100% yield from dihydroeugenol, including 98% yield of the hydrocarbon propylcyclohexane. The final hydrocarbon distribution was shown to be a strong function of hydrogen partial pressure. Kinetic analysis showed three main dihydroeugenol reaction pathways: HDO, hydrogenation, and alkylation. The major pathway occurred via Pt catalyzed hydrogenation of the aromatic ring and methoxy group cleavage to form 4-propylcyclohexanol, then Mo catalyzed removal of the hydroxyl group by dehydration to form propylcyclohexene, followed by hydrogenation of propylcyclohexene on either the Pt or Mo to form the propylcyclohexane. Transalkylation by the methoxy group occurred as a minor side reaction. Catalyst characterization techniques including chemisorption, scanning transmission electron microscopy, X-ray absorption spectroscopy, and X-ray photoelectron spectroscopy were employed to characterize the catalyst structure. Catalyst components identified were Pt particles, bimetallic PtMo particles, a Mo carbide-like phase, and Mo oxide phases.

  5. High-quality graphene grown on polycrystalline PtRh{sub 20} alloy foils by low pressure chemical vapor deposition and its electrical transport properties

    Energy Technology Data Exchange (ETDEWEB)

    Yang, He; Shen, Chengmin, E-mail: cmshen@iphy.ac.cn; Tian, Yuan; Bao, Lihong; Chen, Peng; Yang, Rong; Yang, Tianzhong; Li, Junjie; Gu, Changzhi; Gao, Hong-Jun [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

    2016-02-08

    High-quality continuous uniform monolayer graphene was grown on polycrystalline PtRh{sub 20} alloy foils by low pressure chemical vapor deposition. The morphology of graphene was investigated by Raman spectroscopy, scanning electron microscopy, and atomic force microscopy. Analysis results confirm that high quality single-layer graphene was fabricated on PtRh{sub 20} foil at 1050 °C using a lower flux of methane under low pressure. Graphene films were transferred onto the SiO{sub 2}/Si substrate by the bubbling transfer method. The mobility of a test field effect transistor made of the graphene grown on PtRh{sub 20} was measured and reckoned at room temperature, showing that the carrier mobility was about 4000 cm{sup 2} V{sup −1} s{sup −1}. The results indicate that desired quality of single-layer graphene grown on PtRh{sub 20} foils can be obtained by tuning reaction conditions.

  6. Pressure dependence of morphology and phase composition of SiC films deposited by microwave plasma chemical vapor deposition on cemented carbide substrates

    Energy Technology Data Exchange (ETDEWEB)

    Yu Shengwang, E-mail: bkdysw@yahoo.cn; Fan Pengwei; Tang Weizhong; Li Xiaojing; Hu Haolin; Hei Hongjun; Zhang Sikai; Lu Fanxiu

    2011-11-01

    SiC films were deposited on cemented carbide substrates by employing microwave plasma chemical vapor deposition method using tetramethylsilane (Si(CH{sub 3}){sub 4}) diluted in H{sub 2} as the precursor. Scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction and scratching technique were used to characterize morphology, composition, phases present and adhesion of the films. Experimental results show that the deposition pressure has great influence on morphologies and phase composition of the films. In sequence, SiC films with a cauliflower-like microstructure, granular films with terrace-featured SiC particles coexisting with Co{sub 2}Si compound and clusters of nanometer SiC nanoplatelets appear as a function of the deposition pressure. In terms of plasma density and substrate temperature, this sequential appearance of microstructures of SiC films was explained. Adhesion tests showed that among the three types of films studied, the films with the terrace-featured SiC particles have relatively higher adhesion. Such knowledge will be of importance when the SiC films are used as interlayer between diamond films and cemented carbide substrates.

  7. Pressure dependence of morphology and phase composition of SiC films deposited by microwave plasma chemical vapor deposition on cemented carbide substrates

    International Nuclear Information System (INIS)

    Yu Shengwang; Fan Pengwei; Tang Weizhong; Li Xiaojing; Hu Haolin; Hei Hongjun; Zhang Sikai; Lu Fanxiu

    2011-01-01

    SiC films were deposited on cemented carbide substrates by employing microwave plasma chemical vapor deposition method using tetramethylsilane (Si(CH 3 ) 4 ) diluted in H 2 as the precursor. Scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction and scratching technique were used to characterize morphology, composition, phases present and adhesion of the films. Experimental results show that the deposition pressure has great influence on morphologies and phase composition of the films. In sequence, SiC films with a cauliflower-like microstructure, granular films with terrace-featured SiC particles coexisting with Co 2 Si compound and clusters of nanometer SiC nanoplatelets appear as a function of the deposition pressure. In terms of plasma density and substrate temperature, this sequential appearance of microstructures of SiC films was explained. Adhesion tests showed that among the three types of films studied, the films with the terrace-featured SiC particles have relatively higher adhesion. Such knowledge will be of importance when the SiC films are used as interlayer between diamond films and cemented carbide substrates.

  8. Optical Sensor for Diverse Organic Vapors at ppm Concentration Ranges

    Directory of Open Access Journals (Sweden)

    Dora M. Paolucci

    2011-03-01

    Full Text Available A broadly responsive optical organic vapor sensor is described that responds to low concentrations of organic vapors without significant interference from water vapor. Responses to several classes of organic vapors are highlighted, and trends within classes are presented. The relationship between molecular properties (vapor pressure, boiling point, polarizability, and refractive index and sensor response are discussed.

  9. Physicochemical properties of green solvent 1-ethyl-3-methylimidazolium tetrafluoroborate with aniline from T = (293.15 to 323.15) K at atmospheric pressure

    International Nuclear Information System (INIS)

    Srinivasa Rao, V.; Vijaya Krishna, T.; Madhu Mohan, T.; Madhusudana Rao, P.

    2017-01-01

    Highlights: • Nature of interactions in the binary mixture of [Emim][BF 4 ] + aniline are studied. • Excess properties are calculated and correlated using Redlich–Kister equation. • Temperature dependence of the calculated thermophysical propertiesis discussed. - Abstract: Density and speed of sound values are measured for the binary mixture of 1-ethyl-3-methylimidazolium tetrafluoroborate and aniline over the entire range of mole fraction at temperatures from T = (293.15 to 323.15) K under atmospheric pressure. Using the basic experimental results for the molar volume, isentropic compressibility, molar isentropic compressibility, inter molecular free length, excess molar volume, excess isentropic compressibility, excess molar isentropic compressibility and excess intermolecular free length, these values are calculated. The partial molar volumes and partial molar isentropic compressibilities at infinite dilutions have also been calculated. The trends of variation of the properties have been interpreted in light of the solute–solvent interactions occurring in the system. The excess values are fitted to Redlich–Kister polynomial equation to estimate the binary coefficients and standard deviation between the experimental and calculated values. Further, the molecular interactions in the binary mixture system are analysed using the experimental FT-IR spectrum recorded at room temperature.

  10. High-pressure vapor-liquid equilibria of systems containing ethylene glycol, water and methane - Experimental measurements and modeling

    DEFF Research Database (Denmark)

    Folas, Georgios; Berg, Ole J.; Solbraa, Even

    2007-01-01

    This work presents new experimental phase equilibrium measurements of the binary MEG-methane and the ternary MEG-water-methane system at low temperatures and high pressures which are of interest to applications related to natural gas processing. Emphasis is given to MEG and water solubility...... measurements in the gas phase. The CPA and SRK EoS, the latter using either conventional or EoS/G(E) mixing rules are used to predict the solubility of the heavy components in the gas phase. It is concluded that CPA and SRK using the Huron-Vidal mixing rule perform equally satisfactory, while CPA requires...

  11. Water adsorbate phases on ZnO and impact of vapor pressure on the equilibrium shape of nanoparticles

    Science.gov (United States)

    Kenmoe, Stephane; Biedermann, P. Ulrich

    2018-02-01

    ZnO nanoparticles are used as catalysts and have potential applications in gas-sensing and solar energy conversion. A fundamental understanding of the exposed crystal facets, their surface chemistry, and stability as a function of environmental conditions is essential for rational design and improvement of synthesis and properties. We study the stability of water adsorbate phases on the non-polar low-index (10 1 ¯ 0 ) and (11 2 ¯ 0 ) surfaces from low coverage to multilayers using ab initio thermodynamics. We show that phonon contributions and the entropies due to a 2D lattice gas at low coverage and multiple adsorbate configurations at higher coverage have an important impact on the stability range of water adsorbate phases in the (T,p) phase diagram. Based on this insight, we compute and analyze the possible growth mode of water films for pressures ranging from UHV via ambient conditions to high pressures and the impact of water adsorption on the equilibrium shape of nanoparticles in a humid environment. A 2D variant of the Wulff construction shows that the (10 1 ¯ 0 ) and (11 2 ¯ 0 ) surfaces coexist on 12-faceted prismatic ZnO nanoparticles in dry conditions, while in humid environment, the (10 1 ¯ 0 ) surface is selectively stabilized by water adsorption resulting in hexagonal prisms.

  12. Thermophysical properties of biodiesel and related systems: Low-pressure vapor + liquid equilibrium of methyl/ethyl soybean biodiesel

    International Nuclear Information System (INIS)

    Veneral, Josamaique G.; Junior, Dirceu L.R.; Mazutti, Marcio A.; Voll, Fernando A.P.; Cardozo-Filho, Lúcio; Corazza, Marcos L.; Silva, Edson A.; Oliveira, J. Vladimir

    2013-01-01

    Highlights: • Boiling point temperatures for soybean FAME and FAEE measured in the pressure range of (6.7 to 66.7) kPa. • Investigated systems presented a non-ideal behavior, with positive deviations from Raoult’s law. • Experimental data satisfactorily represented by the UNIQUAC model. -- Abstract: In this work, experimental boiling point temperatures for pseudo-binaries (methyl/ethyl biodiesel + methanol/ethanol) and pseudo-ternaries (methyl/ethyl biodiesel + methanol/ethanol + glycerol/water) systems were measured at several pressures ranging from (6.7 to 66.7) kPa using an Othmer-type ebulliometer. The systems investigated show a non-ideal behavior, with positive deviations from Raoult’s law. It was observed that the addition of up to 10 wt% of alcohol (methanol or ethanol) led to a significant decrease in the boiling point temperature of the systems. The UNIQUAC model was successfully used to represent the experimental results, with an overall average deviation between experimental and calculated boiling temperature values of 0.004%

  13. Long-term stable water vapor permeation barrier properties of SiN/SiCN/SiN nanolaminated multilayers grown by plasma-enhanced chemical vapor deposition at extremely low pressures

    International Nuclear Information System (INIS)

    Choi, Bum Ho; Lee, Jong Ho

    2014-01-01

    We investigated the water vapor permeation barrier properties of 30-nm-thick SiN/SiCN/SiN nanolaminated multilayer structures grown by plasma enhanced chemical vapor deposition at 7 mTorr. The derived water vapor transmission rate was 1.12 × 10 −6 g/(m 2 day) at 85 °C and 85% relative humidity, and this value was maintained up to 15 000 h of aging time. The X-ray diffraction patterns revealed that the nanolaminated film was composed of an amorphous phase. A mixed phase was observed upon performing high resolution transmission electron microscope analysis, which indicated that a thermodynamically stable structure was formed. It was revealed amorphous SiN/SiCN/SiN multilayer structures that are free from intermixed interface defects effectively block water vapor permeation into active layer

  14. Solvent substitutes

    International Nuclear Information System (INIS)

    Evanoff, S.P.

    1995-01-01

    The environmental and industrial hygiene regulations promulgated since 1980, most notably the Superfund Amendments and Reauthorization Act (SARA), the Hazardous and Solid Waste Amendments to the Resources Conservation and Recovery Act (RCRA), and the Clean Air Act Amendments of 1990, have brought about an increased emphasis on user exposure, hazardous waste generation, and air emissions. As a result, industry is performing a fundamental reassessment of cleaning solvents, processes, and procedures. The more progressive organizations have made their goal the elimination of solvents that may pose significant potential human health and environmental hazards. This chapter discusses solvent cleaning in metal-finishing, metal-manufacturing, and industrial maintenance applications; precision cleaning; and electronics manufacturing. Nonmetallic cleaning, adhesives, coatings, inks, and aerosols also will be addressed, but in a more cursory manner

  15. Influence of solvent addition on the physicochemical properties of Brazilian gasoline

    Energy Technology Data Exchange (ETDEWEB)

    E.V. Takeshita; R.V.P. Rezende; S.M.A. Guelli; U. de Souza; A.A. Ulson de Souza [Federal University of Santa Catarina, Florianopolis (Brazil). Chemical Engineering Department

    2008-08-15

    The influence of several solvents (anhydrous ethanol, white spirit, alkylbenzene AB9, diesel) on the physicochemical parameters of gasoline was studied according to ASTM international standard methods. The parameters investigated (distillation curves, density, Reid vapor pressure) showed differentiated behavior, depending on the class of the solvent (oxygenated, light and heavy aliphatic, aromatic) and the quantity added to the gasoline. The azeotropic mixtures formed by ethanol and hydrocarbons showed a strong influence on the behavior of the distillation curves and the location of the point of a sudden change in temperature was shown to be a possible way to detect adulterations and determine the quantity of solvent added to the gasoline. 28 refs., 9 figs., 5 tabs.

  16. Ammonia IR Absorbance Measurements with an Equilibrium Vapor Cell

    National Research Council Canada - National Science Library

    Field, Paul

    2004-01-01

    Infrared (IR) absorbance spectra were acquired for 18 ammonia vapor pressures. The vapor pressures were generated with 15 gravimetrically prepared aqueous solutions and three commercial aqueous solutions using a dynamic method I.E...

  17. Effect of the substrate on the properties of ZnO-MgO thin films grown by atmospheric pressure metal-organic chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Torres-Huerta, A.M., E-mail: atohuer@hotmail.com [Instituto Politecnico Nacional, Grupo de Ingenieria en Procesamiento de Materiales CICATA-IPN, Unidad Altamira, km 14.5, Carretera Tampico-Puerto Industrial Altamira. C. P. 89600, Altamira, Tamps (Mexico); Dominguez-Crespo, M.A. [Instituto Politecnico Nacional, Grupo de Ingenieria en Procesamiento de Materiales CICATA-IPN, Unidad Altamira, km 14.5, Carretera Tampico-Puerto Industrial Altamira. C. P. 89600, Altamira, Tamps (Mexico); Brachetti-Sibaja, S.B. [Alumna del postgrado en Tecnologia Avanzada del CICATA-IPN, Unidad Altamira IPN, km 14.5, Carretera Tampico-Puerto Industrial Altamira. C. P. 89600, Altamira, Tamps (Mexico); Arenas-Alatorre, J. [Instituto de Fisica, UNAM, Apartado Postal 20-364, 01000, D.F. (Mexico); Rodriguez-Pulido, A. [Unidad Profesional Adolfo Lopez Mateos, Luis Enrique Erro s/n, 07738, D. F. (Mexico)

    2011-07-01

    The ZnO-MgO alloys possess attractive properties for possible applications in optoelectronic and display devices; however, the optical properties are strongly dependent on the deposition parameters. In this work, the effect of the glassy and metallic substrates on the structural, morphological and optical properties of ZnO-MgO thin films using atmospheric pressure metal-organic chemical vapor deposition was investigated at relatively low deposition temperature, 500 deg. C. Magnesium and zinc acetylacetonates were used as the metal-organic source. X-ray diffraction experiments provided evidence that the kind of substrates cause a deviation of c-axis lattice constant due to the constitution of a oxide mixture (ZnO and MgO) in combination with different intermetallic compounds(Mg{sub 2}Zn{sub 11} and Mg{sub 4}Zn{sub 7}) in the growth films. The substitutional and interstitial sites of Mg{sup 2+} instead of Zn{sup 2+} ions in the lattice are the most probable mechanism to form intermetallic compounds. The optical parameters as well as thickness of the films were calculated by Spectroscopic Ellipsometry using the classical dispersion model based on the sum of the single and double Lorentz and Drude oscillators in combination with Kato-Adachi equations, as well as X-ray reflectivity.

  18. Regulation of Vapor Pressure Deficit by Greenhouse Micro-Fog Systems Improved Growth and Productivity of Tomato via Enhancing Photosynthesis during Summer Season.

    Directory of Open Access Journals (Sweden)

    Dalong Zhang

    Full Text Available The role of a proposed micro-fog system in regulating greenhouse environments and enhancing tomato (Solanum lycopersicum L. productivity during summer season was studied. Experiments were carried out in a multi-span glass greenhouse, which was divided into two identical compartments involving different environments: (1 without environment control and (2 with a micro-fog system operating when the air vapor pressure deficit (VPD of greenhouse was higher than 0.5 KPa. The micro-fog system effectively alleviated heat stress and evaporative demand in the greenhouse during summer season. The physiologically favourable environment maintained by micro-fog treatment significantly enhanced elongation of leaf and stem, which contributed to a substantial elevation of final leaf area and shoot biomass. These improvements in physiological and morphological traits resulted in around 12.3% increase of marketable tomato yield per plant. Relative growth rate (RGR of micro-fog treatment was also significantly higher than control plants, which was mainly determined by the substantial elevation in net assimilation rate (NAR, and to a lesser extent caused by leaf area ratio (LAR. Measurement of leaf gas exchange parameters also demonstrated that micro-fog treatment significantly enhanced leaf photosynthesis capacity. Taken together, manipulation of VPD in greenhouses by micro-fog systems effectively enhanced tomato growth and productivity via improving photosynthesis during summer season.

  19. Doping characteristics of Si-doped n-GaN Epilayers grown by low-pressure metal-organic chemical-vapor deposition

    CERN Document Server

    Noh, S K; Park, S E; Lee, I H; Choi, I H; Son, S J; Lim, K Y; Lee, H J

    1998-01-01

    We studied doping behaviors through analysis of the electronic properties of a series of undoped and Si-doped GaN epilayers grown on (0001) sapphire substrates by the low-pressure metal-organic chemical-vapor deposition (LP-MOCVD) technique. The doping efficiency was in the range of 0.4 - 0.8, and an empirical relation expressed as eta = 0.45 log[Si] - 8.1 was obtained. The temperature dependence of carrier concentration showed that the donor activation energy monotonically decreased from 17.6 meV to almost zero as the doping level increased. We suggest that the reduction in the activation energy is related not to autodoped defect centers but to doped Si donors and that the behavior originates from the formation of an impurity band. On the basis of an abrupt change in the compensation ratio from 0.9 to 0.5 by Si-doping, an exceptional difference in the Hall mobility between the undoped and the Si-doped films is explained by a mixed conduction mechanism of electrons and holes.

  20. The photosynthetic response of tobacco plants overexpressing ice plant aquaporin McMIPB to a soil water deficit and high vapor pressure deficit.

    Science.gov (United States)

    Kawase, Miki; Hanba, Yuko T; Katsuhara, Maki

    2013-07-01

    We investigated the photosynthetic capacity and plant growth of tobacco plants overexpressing ice plant (Mesembryanthemum crystallinum L.) aquaporin McMIPB under (1) a well-watered growth condition, (2) a well-watered and temporal higher vapor pressure deficit (VPD) condition, and (3) a soil water deficit growth condition to investigate the effect of McMIPB on photosynthetic responses under moderate soil and atmospheric humidity and water deficit conditions. Transgenic plants showed a significantly higher photosynthesis rate (by 48 %), higher mesophyll conductance (by 52 %), and enhanced growth under the well-watered growth condition than those of control plants. Decreases in the photosynthesis rate and stomatal conductance from ambient to higher VPD were slightly higher in transgenic plants than those in control plants. When plants were grown under the soil water deficit condition, decreases in the photosynthesis rate and stomatal conductance were less significant in transgenic plants than those in control plants. McMIPB is likely to work as a CO2 transporter, as well as control the regulation of stomata to water deficits.

  1. Comparisons of the Effects of Elevated Vapor Pressure Deficit on Gene Expression in Leaves among Two Fast-Wilting and a Slow-Wilting Soybean.

    Directory of Open Access Journals (Sweden)

    Mura Jyostna Devi

    Full Text Available Limiting the transpiration rate (TR of a plant under high vapor pressure deficit (VPD has the potential to improve crop yield under drought conditions. The effects of elevated VPD on the expression of genes in the leaves of three soybean accessions, Plant Introduction (PI 416937, PI 471938 and Hutcheson (PI 518664 were investigated because these accessions have contrasting responses to VPD changes. Hutcheson, a fast-wilting soybean, and PI 471938, a slow-wilting soybean, respond to increased VPD with a linear increase in TR. TR of the slow-wilting PI 416937 is limited when VPD increases to greater than about 2 kPa. The objective of this study was to identify the response of the transcriptome of these accessions to elevated VPD under well-watered conditions and identify responses that are unique to the slow-wilting accessions. Gene expression analysis in leaves of genotypes PI 471938 and Hutcheson showed that 22 and 1 genes, respectively, were differentially expressed under high VPD. In contrast, there were 944 genes differentially expressed in PI 416937 with the same increase in VPD. The increased alteration of the transcriptome of PI 416937 in response to elevated VPD clearly distinguished it from the other slow-wilting PI 471938 and the fast-wilting Hutcheson. The inventory and analysis of differentially expressed genes in PI 416937 in response to VPD is a foundation for further investigation to extend the current understanding of plant hydraulic conductivity in drought environments.

  2. Surface roughening of undoped and in situ B-doped SiGe epitaxial layers deposited by using reduced pressure chemical vapor deposition

    Science.gov (United States)

    Kim, Youngmo; Park, Jiwoo; Sohn, Hyunchul

    2018-01-01

    Si1- x Ge x (:B) epitaxial layers were deposited by using reduced pressure chemical vapor deposition with SiH4, GeH4, and B2H6 source gases, and the dependences of the surface roughness of undoped Si1- x Ge x on the GeH4 flow rate and of Si1- x Ge x :B on the B2H6 flow rate were investigated. The root-mean-square (RMS) roughness value of the undoped Si1- x Ge x at constant thickness increased gradually with increasing Ge composition, resulting from an increase in the amplitude of the wavy surface before defect formation. At higher Ge compositions, the residual strain in Si1- x Ge x significantly decreased through the formation of defects along with an abrupt increase in the RMS roughness. The variation of the surface roughness of Si1- x Ge x :B depended on the boron (B) concentration. At low B concentrations, the RMS roughness of Si1- x Ge x remained constant regardless of Ge composition, which is similar to that of undoped Si1- x Ge x . However, at high B concentrations, the RMS roughness of Si1- x Ge x :B increased greatly due to B islanding. In addition, at very high B concentrations ( 9.9 at%), the RMS roughness of Si1- x Ge x :B decreased due to non-epitaxial growth.

  3. Increased vapor pressure deficit due to higher temperature leads to greater transpiration and faster mortality during drought for tree seedlings common to the forest-grassland ecotone.

    Science.gov (United States)

    Will, Rodney E; Wilson, Stuart M; Zou, Chris B; Hennessey, Thomas C

    2013-10-01

    Tree species growing along the forest-grassland ecotone are near the moisture limit of their range. Small increases in temperature can increase vapor pressure deficit (VPD) which may increase tree water use and potentially hasten mortality during severe drought. We tested a 40% increase in VPD due to an increase in growing temperature from 30 to 33°C (constant dewpoint 21°C) on seedlings of 10 tree species common to the forest-grassland ecotone in the southern Great Plains, USA. Measurement at 33 vs 30°C during reciprocal leaf gas exchange measurements, that is, measurement of all seedlings at both growing temperatures, increased transpiration for seedlings grown at 30°C by 40% and 20% for seedlings grown at 33°C. Higher initial transpiration of seedlings in the 33°C growing temperature treatment resulted in more negative xylem water potentials and fewer days until transpiration decreased after watering was withheld. The seedlings grown at 33°C died 13% (average 2 d) sooner than seedlings grown at 30°C during terminal drought. If temperature and severity of droughts increase in the future, the forest-grassland ecotone could shift because low seedling survival rate may not sufficiently support forest regeneration and migration. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  4. Prediction of supercooled liquid vapor pressures and n-octanol/air partition coefficients for polybrominated diphenyl ethers by means of molecular descriptors from DFT method

    International Nuclear Information System (INIS)

    Wang Zunyao; Zeng Xiaolan; Zhai Zhicai

    2008-01-01

    The molecular geometries of 209 polybrominated diphenyl ethers (PBDEs) were optimized at the B3LYP/6-31G* level with Gaussian 98 program. The calculated structural parameters were taken as theoretical descriptors to establish two novel QSPR models for predicting supercooled liquid vapor pressures (P L ) and octanol/air partition coefficients (K OA ) of PBDEs based on the theoretical linear solvation energy relationship (TLSER) model, respectively. The two models achieved in this work both contain three variables: most negative atomic partial charge in molecule (q - ), dipole moment of the molecules (μ) and mean molecular polarizability (α), of which R 2 values are both as high as 0.997, their root-mean-square errors in modeling (RSMEE) are 0.069 and 0.062 respectively. In addition, the F-value of two models are both evidently larger than critical values F 0.05 and the variation inflation factors (VIF) of variables herein are all less than 5.0, suggesting obvious statistic significance of the P L and K OA predicting models. The results of Leave-One-Out (LOO) cross-validation for training set and validation with external test set both show that the two models obtained exhibited optimum stability and good predictive power. We suggest that the QSPRs derived here can be used to predict accurately P L and K OA for non-tested PBDE congeners from Mono-BDEs to Hepta-BDEs and from Mono-BDEs to Hexa-BDEs, respectively

  5. Regulation of Vapor Pressure Deficit by Greenhouse Micro-Fog Systems Improved Growth and Productivity of Tomato via Enhancing Photosynthesis during Summer Season.

    Science.gov (United States)

    Zhang, Dalong; Zhang, Zhongdian; Li, Jianming; Chang, Yibo; Du, Qingjie; Pan, Tonghua

    2015-01-01

    The role of a proposed micro-fog system in regulating greenhouse environments and enhancing tomato (Solanum lycopersicum L.) productivity during summer season was studied. Experiments were carried out in a multi-span glass greenhouse, which was divided into two identical compartments involving different environments: (1) without environment control and (2) with a micro-fog system operating when the air vapor pressure deficit (VPD) of greenhouse was higher than 0.5 KPa. The micro-fog system effectively alleviated heat stress and evaporative demand in the greenhouse during summer season. The physiologically favourable environment maintained by micro-fog treatment significantly enhanced elongation of leaf and stem, which contributed to a substantial elevation of final leaf area and shoot biomass. These improvements in physiological and morphological traits resulted in around 12.3% increase of marketable tomato yield per plant. Relative growth rate (RGR) of micro-fog treatment was also significantly higher than control plants, which was mainly determined by the substantial elevation in net assimilation rate (NAR), and to a lesser extent caused by leaf area ratio (LAR). Measurement of leaf gas exchange parameters also demonstrated that micro-fog treatment significantly enhanced leaf photosynthesis capacity. Taken together, manipulation of VPD in greenhouses by micro-fog systems effectively enhanced tomato growth and productivity via improving photosynthesis during summer season.

  6. Characterization of the Sublimation and Vapor Pressure of 2-(2-Nitrovinyl) Furan (G-0) Using Thermogravimetric Analysis: Effects of Complexation with Cyclodextrins.

    Science.gov (United States)

    Ruz, Vivian; González, Mirtha Mayra; Winant, Danny; Rodríguez, Zenaida; Van den Mooter, Guy

    2015-08-19

    In the present work, the sublimation of crystalline solid 2-(2-nitrovinyl) furan (G-0) in the temperature range of 35 to 60 °C (below the melting point of the drug) was studied using thermogravimetric analysis (TGA). The sublimated product was characterized using Fourier-transformed-infrared spectroscopy (FT-IR) and thin layer chromatography (TLC). The sublimation rate at each temperature was obtained using the slope of the linear regression model and followed apparent zero-order kinetics. The sublimation enthalpy from 35 to 60 °C was obtained from the Eyring equation. The Gückel method was used to estimate the sublimation rate and vapor pressure at 25 °C. Physical mixtures, kneaded and freeze-dried complexes were prepared with 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) and sulfobutyl ether-β-cyclodextrin (SBE-β-CD) and analyzed using isothermal TGA at 50 °C. The complexation contributed to reducing the sublimation process. The best results were achieved using freeze-dried complexes with both cyclodextrins.

  7. Sustainable and Low Viscous 1-Allyl-3-methylimidazolium Acetate + PEG Solvent for Cellulose Processing

    Directory of Open Access Journals (Sweden)

    Airong Xu

    2017-02-01

    Full Text Available Developing sustainable, low viscous and efficient solvents are always advantageous to the processing/fabricating of cellulose materials in practical applications. To this end, in this work novel solvents were developed; ([Amim][CH3COO]/PEG by dissolving polyethylene glycol 200 (PEG-200 in 1-allyl-3-methylimidazolium acetate ([Amim][CH3COO]. The solubilities of cellulose in [Amim][CH3COO]/PEG solvents were determined as a function of temperature, and the possible dissolution mechanism of cellulose in [Amim][CH3COO]/PEG solvent was investigated. The novel solvent exhibits outstanding advantages for good dissolution capacity of cellulose, such as low viscosity, negligible vapor pressure, and recycling capability. The [CH3COO]− anion and the [Amim]+ cation of [Amim][CH3COO] in [Amim][CH3COO]/PEG-10 are the driving force for cellulose dissolution verified by the 13C NMR spectra. In addition, the regenerated cellulose films from [Amim][CH3COO]/PEG solvent were characterized by scanning electron microscopy (SEM, X-ray diffraction (XRD, attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR, and thermogravimetric analysis (TGA to estimate their morphologies and structures.

  8. Performance of thermal solvent process in Athabasca reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Das, Swapan [Marathon Oil (Canada)

    2011-07-01

    In the petroleum industry, due to depletion of conventional resources and high demand operators are looking into heavy oil and bitumen production. Different recovery methods exist, some of them based on heating the reservoir and others on the use of solvent. Thermal solvent process is a combination of both: a small amount of heat is used to maintain a solvent vapor phase in the reservoir. This process has advantages, solvent is mostly recycled which increases bitumen recovery efficiency and reduces the need for fresh solvent, but it also poses challenges, such as maintaining a vapor chamber and the fact that solvent solubility might be affected by heating. The aim of this paper is to discuss these issues. Simulations and field tests were conducted on bitumen in the the Athabasca region. This paper presented a thermal solvent process and its application's results in Athabasca reservoir.

  9. Atmospheric Pressure Chemical Vapor Deposition of CdTe for High-Efficiency Thin-Film PV Devices; Annual Report, 26 January 1998-25 January 1999

    Energy Technology Data Exchange (ETDEWEB)

    Meyers, P. V. [ITN Energy Systems, Wheat Ridge, Colorado (US); Kee, R.; Wolden, C.; Raja, L.; Kaydanov, V.; Ohno, T.; Collins, R.; Aire, M.; Kestner, J. [Colorado School of Mines, Golden, Colorado (US); Fahrenbruch, A. [ALF, Inc., Stanford, California (US)

    1999-09-30

    ITN's 3-year project, titled ''Atmospheric Pressure Chemical Vapor Deposition (APCVD) of CdTe for High-Efficiency Thin-Film Photovoltaic (PV) Devices,'' has the overall objectives of improving thin-film CdTe PV manufacturing technology and increasing CdTe PV device power conversion efficiency. CdTe deposition by APCVD employs the same reaction chemistry as has been used to deposit 16%-efficient CdTe PV films, i.e., close-spaced sublimation, but employs forced convection rather than diffusion as a mechanism of mass transport. Tasks of the APCVD program center on demonstrating APCVD of CdTe films, discovering fundamental mass-transport parameters, applying established engineering principles to the deposition of CdTe films, and verifying reactor design principles that could be used to design high-throughput, high-yield manufacturing equipment. Additional tasks relate to improved device measurement and characterization procedures that can lead to a more fundamental understanding of CdTe PV device operation, and ultimately, to higher device conversion efficiency and greater stability. Specifically, under the APCVD program, device analysis goes beyond conventional one-dimensional device characterization and analysis toward two-dimension measurements and modeling. Accomplishments of the first year of the APCVD subcontract include: selection of the Stagnant Flow Reactor design concept for the APCVD reactor, development of a detailed reactor design, performance of detailed numerical calculations simulating reactor performance, fabrication and installation of an APCVD reactor, performance of dry runs to verify reactor performance, performance of one-dimensional modeling of CdTe PV device performance, and development of a detailed plan for quantification of grain-boundary effects in polycrystalline CdTe devices.

  10. Externally predictive quantitative modeling of supercooled liquid vapor pressure of polychlorinated-naphthalenes through electron-correlation based quantum-mechanical descriptors.

    Science.gov (United States)

    Vikas; Chayawan

    2014-01-01

    For predicting physico-chemical properties related to environmental fate of molecules, quantitative structure-property relationships (QSPRs) are valuable tools in environmental chemistry. For developing a QSPR, molecular descriptors computed through quantum-mechanical methods are generally employed. The accuracy of a quantum-mechanical method, however, rests on the amount of electron-correlation estimated by the method. In this work, single-descriptor QSPRs for supercooled liquid vapor pressure of chloronaphthalenes and polychlorinated-naphthalenes are developed using molecular descriptors based on the electron-correlation contribution of the quantum-mechanical descriptor. The quantum-mechanical descriptors for which the electron-correlation contribution is analyzed include total-energy, mean polarizability, dipole moment, frontier orbital (HOMO/LUMO) energy, and density-functional theory (DFT) based descriptors, namely, absolute electronegativity, chemical hardness, and electrophilicity index. A total of 40 single-descriptor QSPRs were developed using molecular descriptors computed with advanced semi-empirical (SE) methods, namely, RM1, PM7, and ab intio methods, namely, Hartree-Fock and DFT. The developed QSPRs are validated using state-of-the-art external validation procedures employing an external prediction set. From the comparison of external predictivity of the models, it is observed that the single-descriptor QSPRs developed using total energy and correlation energy are found to be far more robust and predictive than those developed using commonly employed descriptors such as HOMO/LUMO energy and dipole moment. The work proposes that if real external predictivity of a QSPR model is desired to be explored, particularly, in terms of intra-molecular interactions, correlation-energy serves as a more appropriate descriptor than the polarizability. However, for developing QSPRs, computationally inexpensive advanced SE methods such as PM7 can be more reliable than

  11. Electrochemical performance of LiFePO4 modified by pressure-pulsed chemical vapor infiltration in lithium-ion batteries

    International Nuclear Information System (INIS)

    Li Jianling; Suzuki, Tomohiro; Naga, Kazuhisa; Ohzawa, Yoshimi; Nakajima, Tsuyoshi

    2007-01-01

    Using the pressure-pulsed chemical vapor infiltration (PCVI) technique, pyrolytic carbon (pyrocarbon) films were deposited on the surface of LiFePO 4 particles for cathode material of lithium-ion batteries. The electrochemical performance of the original LiFePO 4 and PCVIed LiFePO 4 materials was evaluated using a three electrodes cell by galvanostatic charging/discharging at 25, 40 and 55 deg. C, respectively. Morphology and structure of LiFePO 4 were analyzed by SEM, XRD and Raman. The resulting carbon contents at 500, 1000, 2000, 3000 and 5000 pulses were 2.7, 4.7, 9.5, 15.1 and 19.4%, respectively and these samples were abbreviated as 500P, 1000P, 2000P, 3000P and 5000P, respectively. All the PCVIed samples exhibited excellent rate performance. The tendency was more and more obvious with the increase of the current densities. The specific capacities of 500P, 1000P and 2000P were maintained at 117, 124 and 132 mAh g -1 , respectively, which were 120.8, 264.7 and 29.47% larger than those of corresponding original LiFePO 4 , respectively, at a 5C rate at 55 deg. C. The EIS measurement showed that electrochemical reaction resistance (R ct ) of PCVIed LiFePO 4 were obviously decreased, indicating a fast kinetics compared to the original LiFePO 4 . The cycle ability of the 2000P sample was tested at 25 deg. C and C/2 rate. The cell was cycled for 150 cycles and no obviously capacity fade was observed. Its specific capacity of 115 mAh g -1 at 150th cycle is 1.7 times higher than that of original LiFePO 4

  12. GeSn growth kinetics in reduced pressure chemical vapor deposition from Ge2H6 and SnCl4

    Science.gov (United States)

    Aubin, J.; Hartmann, J. M.

    2018-01-01

    We have investigated the low temperature epitaxy of high Sn content GeSn alloys in a 200 mm industrial Reduced Pressure - Chemical Vapor Deposition tool from Applied Materials. Gaseous digermane (Ge2H6) and liquid tin tetrachloride (SnCl4) were used as the Ge and Sn precursors, respectively. The impact of temperature (in the 300-350 °C range), Ge2H6 and SnCl4 mass-flows on the GeSn growth kinetics at 100 Torr has been thoroughly explored. Be it at 300 °C or 325 °C, a linear GeSn growth rate increase together with a sub-linear Sn concentration increase occurred as the SnCl4 mass-flow increased, irrespective of the Ge2H6 mass flow (fixed or varying). The Sn atoms seemed to catalyze H desorption from the surface, resulting in higher GeSn growth rates for high SnCl4 mass-flows (in the 4-21 nm min-1 range). The evolution of the Sn content x with the F (SnCl4) 2 ·/F (Ge2H6) mass-flow ratio was fitted by x2/(1 - x) = n ·F (SnCl4) 2 ·/F (Ge2H6), with n = 0.25 (325 °C) and 0.60 (300 °C). We have otherwise studied the impact of temperature, in the 300-350 °C range, on the GeSn growth kinetics. The GeSn growth rate exponentially increased with the temperature, from 15 up to 32 nm min-1. The associated activation energy was low, i.e. Ea = 10 kcal mol-1. Meanwhile, the Sn content decreased linearly as the growth temperature increased, from 15% at 300 °C down to 6% at 350 °C.

  13. Electrochemical performance of LiFePO{sub 4} modified by pressure-pulsed chemical vapor infiltration in lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Li Jianling [Department of Physical Chemistry, University of Science and Technology Beijing, No. 30 College Road, Haidian District, Beijing 100083 (China); Department of Applied Chemistry, Aichi Institute of Technology, Yachigusa 1247, Yakusa-cho, Toyota 470-0392 (Japan)], E-mail: lijianling@metall.ustb.edu.cn; Suzuki, Tomohiro; Naga, Kazuhisa; Ohzawa, Yoshimi; Nakajima, Tsuyoshi [Department of Applied Chemistry, Aichi Institute of Technology, Yachigusa 1247, Yakusa-cho, Toyota 470-0392 (Japan)

    2007-09-25

    Using the pressure-pulsed chemical vapor infiltration (PCVI) technique, pyrolytic carbon (pyrocarbon) films were deposited on the surface of LiFePO{sub 4} particles for cathode material of lithium-ion batteries. The electrochemical performance of the original LiFePO{sub 4} and PCVIed LiFePO{sub 4} materials was evaluated using a three electrodes cell by galvanostatic charging/discharging at 25, 40 and 55 deg. C, respectively. Morphology and structure of LiFePO{sub 4} were analyzed by SEM, XRD and Raman. The resulting carbon contents at 500, 1000, 2000, 3000 and 5000 pulses were 2.7, 4.7, 9.5, 15.1 and 19.4%, respectively and these samples were abbreviated as 500P, 1000P, 2000P, 3000P and 5000P, respectively. All the PCVIed samples exhibited excellent rate performance. The tendency was more and more obvious with the increase of the current densities. The specific capacities of 500P, 1000P and 2000P were maintained at 117, 124 and 132 mAh g{sup -1}, respectively, which were 120.8, 264.7 and 29.47% larger than those of corresponding original LiFePO{sub 4}, respectively, at a 5C rate at 55 deg. C. The EIS measurement showed that electrochemical reaction resistance (R{sub ct}) of PCVIed LiFePO{sub 4} were obviously decreased, indicating a fast kinetics compared to the original LiFePO{sub 4}. The cycle ability of the 2000P sample was tested at 25 deg. C and C/2 rate. The cell was cycled for 150 cycles and no obviously capacity fade was observed. Its specific capacity of 115 mAh g{sup -1} at 150th cycle is 1.7 times higher than that of original LiFePO{sub 4}.

  14. Halogenated methyl-phenyl ethers (anisoles) in the environment: determination of vapor pressures, aqueous solubilities, Henry's law constants, and gas/water- (Kgw), n-octanol/water- (Kow) and gas/n-octanol (Kgo) partition coefficients.

    Science.gov (United States)

    Pfeifer, O; Lohmann, U; Ballschmiter, K

    2001-11-01

    Halogenated methyl-phenyl ethers (methoxybenzenes, anisoles) are ubiquitous organics in the environment although they are not produced in industrial quantities. Modelling the fate of organic pollutants such as halogenated anisoles requires a knowledge of the fundamental physico-chemical properties of these compounds. The isomer-specific separation and detection of 60 of the 134 possible congeners allowing an environmental fingerprinting are reported in this study. The vapor pressure p0(L) of more than 60 and further physico-chemical properties of 26 available congeners are given. Vapor pressures p0(L), water solubilities S(L)W, and n-octanol/water partition coefficients Kow were determined by capillary HR-GC (High Resolution Gas Chromatography) on a non-polar phase and by RP-HPLC (Reversed Phase High Performance Liquid Chromatography) on a C18 phase with chlorobenzenes as reference standards. From these experimental data the Henry's law constants H, and the gas/water Kgw and gas/n-octanol Kgo partition coefficients were calculated. We found that vapor pressures, water solubilities, and n-octanol/water partition coefficients of the halogenated anisoles are close to those of the chlorobenzenes. A similar environmental fate of both groups can, therefore, be predicted.

  15. Observation of vapor pressure enhancement of rare-earth metal-halide salts in the temperature range relevant to metal-halide lamps

    Energy Technology Data Exchange (ETDEWEB)

    Curry, J. J.; Henins, A.; Hardis, J. E. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Estupinan, E. G. [Osram Sylvania Inc., Beverly, Massachusetts 01915 (United States); Lapatovich, W. P. [Independent Consultant, 51 Pye Brook Lane, Boxford, Massachusetts 01921 (United States); Shastri, S. D. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

    2012-02-20

    Total vapor-phase densities of Dy in equilibrium with a DyI{sub 3}/InI condensate and Tm in equilibrium with a TmI{sub 3}/TlI condensate have been measured for temperatures between 900 K and 1400 K. The measurements show strong enhancements in rare-earth vapor densities compared to vapors in equilibrium with the pure rare-earth metal-halides. The measurements were made with x-ray induced fluorescence on the sector 1-ID beam line at the Advanced Photon Source. The temperature range and salt mixtures are relevant to the operation of metal-halide high-intensity discharge lamps.

  16. The large-area CdTe thin film for CdS/CdTe solar cell prepared by physical vapor deposition in medium pressure

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Run; Liu, Bo; Yang, Xiaoyan; Bao, Zheng; Li, Bing, E-mail: libing70@126.com; Zhang, Jingquan; Li, Wei; Wu, Lili; Feng, Lianghuan

    2016-01-01

    Graphical abstract: - Highlights: • The large-area CdTe film has been prepared by PVD under the pressure of 0.9 kPa. • The as-prepared CdTe thin film processes excellent photovoltaic properties. • This technique is suitable for depositing large-area CdTe thin film. • The 14.6% champion efficiency CdS/CdTe cell has been achieved. - Abstract: The Cadmium telluride (CdTe) thin film has been prepared by physical vapor deposition (PVD), the Ar + O{sub 2} pressure is about 0.9 kPa. This method is a newer technique to deposit CdTe thin film in large area, and the size of the film is 30 × 40 cm{sup 2}. This method is much different from the close-spaced sublimation (CSS), as the relevance between the source temperature and the substrate temperature is weak, and the gas phase of CdTe is transferred to the substrate by Ar + O{sub 2} flow. Through this method, the compact and uniform CdTe film (30 × 40 cm{sup 2}) has been achieved, and the performances of the CdTe thin film have been determined by transmission spectrum, SEM and XRD. The film is observed to be compact with a good crystallinity, the CdTe is polycrystalline with a cubic structure and a strongly preferred (1 1 1) orientation. Using the CdTe thin film (3 × 5 cm{sup 2}) which is taken from the deposited large-area film, the 14.6% efficiency CdS/CdTe thin film solar cell has been prepared successfully. The structure of the cell is glass/FTO/CdS/CdTe/graphite slurry/Au, short circuit current density (J{sub sc}) of the cell is 26.9 mA/cm{sup 2}, open circuit voltage (V{sub oc}) is 823 mV, and filling factor (FF) is 66.05%. This technique can be a quite promising method to apply in the industrial production, as it has great prospects in the fabricating of large-area CdTe film.

  17. The relationship between vapour pressure, vaporization enthalpy, and enthalpy of transfer from solution to gas: An extension of the Martin equation

    International Nuclear Information System (INIS)

    Srisaipet, A.; Aryusuk, K.; Lilitchan, S.; Krisnangkura, K.

    2007-01-01

    Martin's equation, Δ sln g G=Δ sln g G o +zδ sln g G, is extended to cover vaporization free energy (Δ l g G). The extended equation is further expanded in terms of enthalpy and entropy and then used to correlate vaporization enthalpy (Δ l g H) and enthalpy of transfer from solution to gas (Δ sln g H). Data available in the literatures are used to validate and support the speculations derived from the proposed equation

  18. Sorption and vapor transmission properties of uncompressed and compressed microcellular starch foam.

    Science.gov (United States)

    Glenn, Gregory M; Klamczynski, Artur P; Takeoka, Gary; Orts, William J; Wood, Delilah; Widmaier, Robert

    2002-11-20

    Microcellular starch foams (MCFs) are made by a solvent-exchange process and consist of a porous matrix with pores generally ranging from approximately 2 microm to submicrometer size. MCF may potentially be useful as a slow-release agent for volatile compounds because of its ability to sorb chemicals from the atmosphere and to absorb liquids into its porous structure, and because it can be compressed to form a starch plastic. MCF made of high-amylose corn and wheat starches was prepared with or without 2% (w/w) silicone oil (SO) or palmitic acid (PA). The MCF was loaded with 1% of various volatile compounds with vapor pressures ranging from 0.02 to 28 mm. The MCF depressed the vapor pressure from 0.37 to 37% compared to a control containing no MCF. Incorporating SO or PA in the matrix of the MCF had little effect on sorption of volatiles. Compressing MCF at 1.4, 6.9, and 69 MPa made a starch plastic with varying porosity. The vapor transmission rate of various volatile compounds through MCF was positively correlated to the vapor pressure of the test compound but was inversely proportional to the compression force used to form the starch plastic. The results indicate that uncompressed and compressed MCFs could be effective slow-release agents for a variety of volatile compounds, especially if used together.

  19. C and Si delta doping in Ge by CH{sub 3}SiH{sub 3} using reduced pressure chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Yuji, E-mail: yamamoto@ihp-microelectronics.com [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); Ueno, Naofumi; Sakuraba, Masao [Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, 2-1-1, Katahira, Aoba-Ku, Sendai 980-8577 (Japan); Murota, Junichi [Micro System Integration Center, Tohoku University, 519-1176, Aramaki aza Aoba, Aoba-ku, Sendai 980-0845 (Japan); Mai, Andreas [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); Tillack, Bernd [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); Technische Universität Berlin, HFT4, Einsteinufer 25, 10587 Berlin (Germany)

    2016-03-01

    C and Si delta doping in Ge are investigated using a reduced pressure chemical vapor deposition system to establish atomic-order controlled processes. CH{sub 3}SiH{sub 3} is exposed at 250 °C to 500 °C to a Ge on Si (100) substrate using H{sub 2} or N{sub 2} carrier gas followed by a Ge cap layer deposition. At 350 °C, C and Si are uniformly adsorbed on the Ge surface and the incorporated C and Si form steep delta profiles below detection limit of SIMS measurement. By using N{sub 2} as carrier gas, the incorporated C and Si doses in Ge are saturated at one mono-layer below 350 °C. At this temperature range, the incorporated C and Si doses are nearly the same, indicating CH{sub 3}SiH{sub 3} is adsorbed on the Ge surface without decomposing the C−Si bond. On the other hand, by using H{sub 2} as carrier gas, lower incorporated C is observed in comparison to Si. CH{sub 3}SiH{sub 3} injected with H{sub 2} carrier gas is adsorbed on Ge without decomposing the C−Si bond and the adsorbed C is reduced by dissociation of the C−Si bond during temperature ramp up to 550 °C. The adsorbed C is maintained on the Ge surface in N{sub 2} at 550 °C. - Highlights: • C and Si delta doping in Ge is investigated using RPCVD system by CH{sub 3}SiH{sub 3} exposure. • Atomically flat C and Si delta layers are fabricated at 350 °C. • Incorporated C and Si doses are saturated at one mono-layer below 350 °C. • CH{sub 3}SiH{sub 3} adsorption occurred without decomposing C−Si bond. • Adsorbed C is desorbed due to dissociation by hydrogen during postannealing at 550 °C.

  20. High temperature and low pressure chemical vapor deposition of silicon nitride on AlGaN: Band offsets and passivation studies

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, Pramod; Washiyama, Shun; Kaess, Felix; Hernandez-Balderrama, Luis H.; Haidet, Brian B.; Alden, Dorian; Franke, Alexander; Sarkar, Biplab; Kohn, Erhard; Collazo, Ramon; Sitar, Zlatko [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695-7919 (United States); Hayden Breckenridge, M. [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695-7919 (United States); REU, Physics Department at Wofford College, Spartanburg, South Carolina 29303 (United States)

    2016-04-14

    In this work, we employed X-ray photoelectron spectroscopy to determine the band offsets and interface Fermi level at the heterojunction formed by stoichiometric silicon nitride deposited on Al{sub x}Ga{sub 1-x}N (of varying Al composition “x”) via low pressure chemical vapor deposition. Silicon nitride is found to form a type II staggered band alignment with AlGaN for all Al compositions (0 ≤ x ≤ 1) and present an electron barrier into AlGaN even at higher Al compositions, where E{sub g}(AlGaN) > E{sub g}(Si{sub 3}N{sub 4}). Further, no band bending is observed in AlGaN for x ≤ 0.6 and a reduced band bending (by ∼1 eV in comparison to that at free surface) is observed for x > 0.6. The Fermi level in silicon nitride is found to be at 3 eV with respect to its valence band, which is likely due to silicon (≡Si{sup 0/−1}) dangling bonds. The presence of band bending for x > 0.6 is seen as a likely consequence of Fermi level alignment at Si{sub 3}N{sub 4}/AlGaN hetero-interface and not due to interface states. Photoelectron spectroscopy results are corroborated by current-voltage-temperature and capacitance-voltage measurements. A shift in the interface Fermi level (before band bending at equilibrium) from the conduction band in Si{sub 3}N{sub 4}/n-GaN to the valence band in Si{sub 3}N{sub 4}/p-GaN is observed, which strongly indicates a reduction in mid-gap interface states. Hence, stoichiometric silicon nitride is found to be a feasible passivation and dielectric insulation material for AlGaN at any composition.

  1. Solvent effects of a dimethyldicyanoquinonediimine buffer layer as N-type material on the performance of organic photovoltaic cells.

    Science.gov (United States)

    Yang, Eui Yeol; Oh, Se Young

    2014-08-01

    In the present work, we have fabricated organic photovoltaic cells consisting of ITO/PEDOT:PSS/P3HT:PCBM/DMDCNQI/Al using a dip-coating method with various solvent systems. We have investigated solvent effects (such as solubility, viscosity and vapor pressure) in deposition of a thin DMDCNQI buffer layer on the performance of organic photovoltaic cells. The solvent system which had low viscosity and good solubility properties, made a dense and uniform DMDCNQI ultra thin film, resulting in a high performance device. In particular, a prepared organic photovoltaic cell was fabricated using a cosolvent system (methanol:methylenechloride = 3:1) and showed a maximum power conversion efficiency of 4.53%.

  2. Vapor pressures of nitric acid and water in the systems HNO3-H2O and HNO3-Th(NO3)4-H2O at 50oC

    International Nuclear Information System (INIS)

    Lemire, R.J.; Brown, C.P.; Campbell, A.B.

    1985-01-01

    The equilibrium compositions of the vapor above nitric acid-water, thorium nitrate-water, and nitric acid-thorium nitrate-water mixtures at 50 o C have been studied as a function of solution concentration by using a transpiration technique. Nitric acid concentrations were varied from 0 to 20 m and thorium nitrate concentrations from 0 to 2.5 m. Our data for the nitric acid-water system have been combined with literature data to obtain parameters for Scatchard's ion-component model, and these parameters provide a satisfactory description of the system at 50 o C over a wide concentration range. The enhancement, at 50 o C, of the nitric acid vapor pressure by added thorium nitrate was found to be less than that previously determined at 25 o C. The data for the nitric acid-thorium nitrate-water system at 50 o C were fitted to a single multiparameter function. (author)

  3. Comparison of the atmospheric- and reduced-pressure HS-SPME strategies for analysis of residual solvents in commercial antibiotics using a steel fiber coated with a multiwalled carbon nanotube/polyaniline nanocomposite.

    Science.gov (United States)

    Ghiasvand, Ali Reza; Nouriasl, Kolsoum; Yazdankhah, Fatemeh

    2018-01-01

    A low-cost, sensitive and reliable reduced-pressure headspace solid-phase microextraction (HS-SPME) setup was developed and evaluated for direct extraction of residual solvents in commercial antibiotics, followed by determination by gas chromatography with flame ionization detection (GC-FID). A stainless steel narrow wire was made porous and adhesive by platinization by a modified electrophoretic deposition method and coated with a polyaniline/multiwalled carbon nanotube nanocomposite. All experimental variables affecting the extraction efficiency were investigated for both atmospheric-pressure and reduced-pressure conditions. Comparison of the optimal experimental conditions and the results demonstrated that the reduced-pressure strategy leads to a remarkable increase in the extraction efficiency and reduction of the extraction time and temperature (10 min, 25 °Ϲ vs 20 min, 40 °Ϲ). Additionally, the reduced-pressure strategy showed better analytical performances compared with those obtained by the conventional HS-SPME-GC-FID method. Limit of detections, linear dynamic ranges, and relative standard deviations of the reduced-pressure HS-SPME procedure for benzene, toluene, ethylbenzene, and xylene (BTEX) in injectable solid drugs were obtained over the ranges of 20-100 pg g -1 , 0.02-40 μg g -1 , and 2.8-10.2%, respectively. The procedure developed was successful for the analysis of BTEX in commercial containers of penicillin, ampicillin, ceftriaxone, and cefazolin. Graphical abstract Schematic representation of the developed RP-HS-SPME setup.

  4. Effective Interfacially Polymerized Polyester Solvent Resistant Nanofiltration Membrane from Bioderived Materials

    KAUST Repository

    Abdellah, Mohamed H.

    2018-05-18

    Utilization of sustainable and environmentally friendly solvents for the preparation of membranes has attracted growing interest in recent years. In this work, a polyester thin film composite solvent resistant nanofiltration (SRNF) membrane is prepared by interfacial polymerization on a cellulose support. The cellulose support is prepared by nonsolvent‐induced phase separation from a dope solution containing an ionic liquid as an environmentally friendly solvent (negligible vapor pressure). The polyester film is formed via the interfacial reaction between quercetin, a plant‐derived polyphenol, and terephthaloyl chloride. Alpha‐pinene is used as a green alternative solvent to dissolve terephthaloyl chloride (TPC) while quercetin is dissolved in a 0.2 m NaOH solution. The interfacial polymerization reaction is successfully confirmed by Fourier transform infrared and X‐ray photoelectron spectroscopy while scanning electron and atomic force microscopy are used to characterize the membrane structure. The composite membrane shows an outstanding performance with a molecular weight cut‐off around 330 Da combined with a dimethylformamide (DMF) permeance up to 2.8 L m−2 bar−1 h−1. The membrane is stable in strong aprotic solvents such as DMF offering potential application in the pharmaceutical and petrochemical industries.

  5. Supercritical solvent extraction of oil sand bitumen

    Science.gov (United States)

    Imanbayev, Ye. I.; Ongarbayev, Ye. K.; Tileuberdi, Ye.; Mansurov, Z. A.; Golovko, A. K.; Rudyk, S.

    2017-08-01

    The supercritical solvent extraction of bitumen from oil sand studied with organic solvents. The experiments were performed in autoclave reactor at temperature above 255 °C and pressure 29 atm with stirring for 6 h. The reaction resulted in the formation of coke products with mineral part of oil sands. The remaining products separated into SARA fractions. The properties of the obtained products were studied. The supercritical solvent extraction significantly upgraded extracted natural bitumen.

  6. Validation of Alternatives to High Volatile Organic Compound Solvents Used in Aeronautical Antifriction Bearing Cleaning

    Science.gov (United States)

    2006-10-17

    982-4832 (fax) tom.torres@navy.mil Quality Assurance Officer Gene Griffin NFESC 1100 23rd Avenue Port Hueneme, CA 93043-4370 (805) 982-2267...solvent replenishment system. The waste solvent shall be captured in a sealed container that is easily acces· sible for periodic disposal. (2) HFE ...Co-Solvent Vapor Degreaser. This method features the use of a hydrocarbon (HC) solvating agent and a Hydrofluoroether ( HFE ) liquid rinse and vapor

  7. Solvent/Non-Solvent Sintering To Make Microsphere Scaffolds

    Science.gov (United States)

    Laurencin, Cato T.; Brown, Justin L.; Nair, Lakshmi

    2011-01-01

    A solvent/non-solvent sintering technique has been devised for joining polymeric microspheres to make porous matrices for use as drug-delivery devices or scaffolds that could be seeded with cells for growing tissues. Unlike traditional sintering at elevated temperature and pressure, this technique is practiced at room temperature and pressure and, therefore, does not cause thermal degradation of any drug, protein, or other biochemical with which the microspheres might be loaded to impart properties desired in a specific application. Also, properties of scaffolds made by this technique are more reproducible than are properties of comparable scaffolds made by traditional sintering. The technique involves the use of two miscible organic liquids: one that is and one that is not a solvent for the affected polymer. The polymeric microspheres are placed in a mold having the size and shape of the desired scaffold, then the solvent/non-solvent mixture is poured into the mold to fill the void volume between the microspheres, then the liquid mixture is allowed to evaporate. Some of the properties of the resulting scaffold can be tailored through choice of the proportions of the liquids and the diameter of the microspheres.

  8. A study of the evaporation of a solvent from a solution--application to writing ink aging.

    Science.gov (United States)

    Cantú, Antonio A

    2012-06-10

    When writing ink is placed on a substrate, a drying process begins. This process is dependent on the composition of the ink and of the substrate. Lociciro et al. provide an equation that describes the drying process based on models developed by earlier investigators. The work given here develops an equation for the drying process that is based on a different and rather simple model. This model considers the evaporation of a solution in an opened vertical container (e.g., a beaker) and consists of a volatile, non-hygroscopic solvent with a non-volatile solute dissolved in it. Three assumptions are made: (a) the rate of evaporation is proportional to the vapor pressure of the solution and to the solution's exposed surface area, (b) this solution vapor pressure is proportional to the solvent vapor pressure with the proportionality constant being the solvent mole fraction (Raoult's law), and (c) a small fraction of the solvent remains trapped in the solute after evaporation ceases. What results is a differential equation, which, when solved, gives the solvent weight W(t) as an implicit function. What emerges naturally from this treatment is the fact that the function W(t) can have a point of maximum acceleration. Prior to this point the drying process is fast and after this point, the drying process is slow. An approximation to W(t) is taken to be the sum of two exponential functions, one describing the fast drying region and the second describing the subsequent slow drying region. Upon including an additive constant, this approximation turns out to be similar to, but not the same as that provided by Lociciro et al. However, their equivalence is shown and then tested using the two inks examined by Lociciro et al. (the drying of a Bic and a Staedtler blue ballpoint ink). The examples of (solvent+solute) systems ("inks") given here consist of the solvent (2-phenoxyethanol) and a solute such as a dye (crystal violet) or a polymer resin such as synthetic resin SK or

  9. Saturated vapor pressure over molten mixtures of GaCl{sub 3} and alkali metal chlorides; Davlenie nasyshchennykh parov rasplavlennykh smesej CaCl{sub 3} s khloridami shchelochnykh metallov

    Energy Technology Data Exchange (ETDEWEB)

    Salyulev, A B; Smolenskij, V V; Moskalenko, N I [UrO RAN, Inst. Vysokotemperaturnoj Ehlektrokhimii, Elaterinburg (Russian Federation)

    2004-07-01

    Volatilities of GaCl{sub 3} and alkali metal chlorides over diluted (up to 3 mol %) solutions of GaCl{sub 3} in LiCl, NaCl, KCl, RbCl, and CsCl were measured at 1100 K by dynamic and indirect static methods. Chemical composition of saturated vapor over the mixed melts was determined. Partial pressures of the components were calculated. Their values depend essentially on specific alkali metal cation and on concentration of GaCl{sub 3}; their variation permits altering parameters of GaCl{sub 3} distillation from the salt melt in a wide range.

  10. Mobile vapor recovery and vapor scavenging unit

    International Nuclear Information System (INIS)

    Stokes, C.A.; Steppe, D.E.

    1991-01-01

    This patent describes a mobile anti- pollution apparatus, for the recovery of hydrocarbon emissions. It comprises a mobile platform upon which is mounted a vapor recovery unit for recovering vapors including light hydrocarbons, the vapor recovery unit having an inlet and an outlet end, the inlet end adapted for coupling to an external source of hydrocarbon vapor emissions to recover a portion of the vapors including light hydrocarbons emitted therefrom, and the outlet end adapted for connection to a means for conveying unrecovered vapors to a vapor scavenging unit, the vapor scavenging unit comprising an internal combustion engine adapted for utilizing light hydrocarbon in the unrecovered vapors exiting from the vapor recovery unit as supplemental fuel

  11. Improved procedure for high purity gaseous peroxyacyl nitrate production: use of heavy lipid solvents

    Energy Technology Data Exchange (ETDEWEB)

    Gaffney, J S; Fajer, R; Senum, G I

    1984-01-01

    An improved procedure is described for the production of peroxyacyl nitrates (PAN's) in the gas phase. The method of Nielsen et al. (1982) has been modified to yield PAN's of high purity with no further chromatographic purification required. Extraction of PAN's from the nitration of the peracids is accomplished by use of a heavy lipid solvent (n-tridecane). This solvent's low vapor pressure allows the simple separation and preparation of high purity gaseous PAN's (>98%) as determined by Fourier transform infrared spectroscopy (FTIR). Using this method infrared integrated band strengths are reported for peroxyacetyl nitrate (PAN) perdeutero-peroxyacetyl nitrate (PAN-D/sub 3/) and peroxyproprionyl nitrate (PPN). The method allows facile production of large amounts of gaseous PAN's for smog chamber and laboratory studies, toxicological and health effects research, as well as for calibration of PAN analyses.

  12. The lithium vapor box divertor

    International Nuclear Information System (INIS)

    Goldston, R J; Schwartz, J; Myers, R

    2016-01-01

    It has long been recognized that volumetric dissipation of the plasma heat flux from a fusion power system is preferable to its localized impingement on a material surface. Volumetric dissipation mitigates both the anticipated very high heat flux and intense particle-induced damage due to sputtering. Recent projections to a tokamak demonstration power plant suggest an immense upstream parallel heat flux, of order 20 GW m −2 , implying that fully detached operation may be a requirement for the success of fusion power. Building on pioneering work on the use of lithium by Nagayama et al and by Ono et al as well as earlier work on the gas box divertor by Watkins and Rebut, we present here a concept for a lithium vapor box divertor, in which lithium vapor extracts momentum and energy from a fusion-power-plant divertor plasma, using fully volumetric processes. At the high powers and pressures that are projected this requires a high density of lithium vapor, which must be isolated from the main plasma in order to avoid lithium build-up on the chamber walls or in the plasma. Isolation is achieved through a powerful multi-box differential pumping scheme available only for condensable vapors. The preliminary box-wise calculations are encouraging, but much more work is required to demonstrate the practical viability of this scheme, taking into account at least 2D plasma and vapor flows within and between the vapor boxes and out of the vapor boxes to the main plasma. (paper)

  13. [Chemical hazards when working with solvent glues].

    Science.gov (United States)

    Domański, Wojciech; Makles, Zbigniew

    2012-01-01

    Solvent glues are used in a wide variety of industries, e.g., textile, footwear and rubber. The problem of workers' exposure to solvent vapors is rarely tackled within the area of occupational safety and health in small and medium-sized enterprises. In order to assess exposure to solvents, organic solvents emitted by glues were identified in the samples of workplace air. The concentration of acetone, benzene, cyclohexane, ethylbenzene, n-hexane, methylcyclohexane, butyl acetate and toluene were determined. The obtained results evidenced the presence of cyclohexane, ethylbenzene, ethylcyclohexane, heptane, n-hexane, o-xylene, methylcyclohexane, methylcyclopentane, butyl acetate and toluene in workplace air. The concentration of those compounds in workplace air was low, usually below 0.15 of MAC. At some workstations the presence of benzene was also observed. Occupational risk was assessed at workstations where gluing took place. It showed that the risk at those workstations was medium or low.

  14. Comparative analysis of high pressure sodium vapor lamps and mercury vapor lamp with the solid state (LED) in the public lighting systems; Analise comparativa das lampadas de vapor de sodio a alta pressao e de vapor de mercurio com a lampada a estado solido (LED) em sistemas de iluminacao publica

    Energy Technology Data Exchange (ETDEWEB)

    Damato, J.C.; Bueno, J.E.; Astorga, O.A.M. [Universidade Estadual Paulista (LESIP/UNESP), Guaratingueta, SP (Brazil). Lab. de Eficiencia Energetica em Sistemas de Iluminacao Publica; Ricciulli, D.L.S. [Universidade Estadual Paulista (DEE/UNESP), Guaratingueta, SP (Brazil). Dept. de Engenharia Eletrica

    2009-07-01

    The necessity of energy conservation in Brazilian electric sector, with the intention to diminish the resources of generation investments, has going to use of electric energy conservation programs, being most important PROCEL - a national program of electric conservation energy by ELETROBRAS, and inside this, a national program for public illumination and efficient traffic signaling - named 'Reluz'. This program looks for a more efficient implantation of public lighting systems, that requires the use of lamp technologies that present a greater value in a relation between lumen/watt relation and then beyond providing economy, due to low consumption of electric energy. Besides technologies that are appearing, the inclusion of LED lamps, which offers a great application potential, comes blunting as improvement alternative, being that the next public illumination parks will be able count on these lamps associates to the high-pressure sodium lamps and other types currently used. (author)

  15. CH3NH3I treatment temperature of 70 °C in low-pressure vapor-assisted deposition for mesoscopic perovskite solar cells

    Science.gov (United States)

    Jin, Wenbin; Zou, Xiaoping; Bai, Xiao; Yang, Ying; Chen, Dan

    2018-01-01

    Herein, we report a modified vapor-assisted deposition method to fabricate CH3NH3PbI3 film at 70 °C in a vacuum drying oven. The modified method has excellent operability and expandability in preparing perovskite solar cells. The CH3NH3I treatment temperature is 130 °C or 150 °C in conventional method, but we reduced the temperature to 70 °C in the modified vapor-assisted method. Meanwhile, the quality of CH3NH3PbI3 films prepared via the modified method is superior to that of CH3NH3PbI3 films of solution-processed method.

  16. Solvents, Ethanol, Car Crashes and Tolerance: How Risky is Inhalation of Organic Solvents?

    Science.gov (United States)

    A research program in the National Health and Environmental Effects Research Laboratory of the U.S. EPA has led to some surprising considerations regarding the potential hazard of exposure to low concentrations of solvent vapors. This program involved conducting experiments to ch...

  17. Phenothiazine-based small-molecule organic solar cells with power conversion efficiency over 7% and open circuit voltage of about 1.0 V using solvent vapor annealing.

    Science.gov (United States)

    Rout, Yogajivan; Misra, Rajneesh; Singhal, Rahul; Biswas, Subhayan; Sharma, Ganesh D

    2018-02-28

    We have used two unsymmetrical small molecules, named phenothiazine 1 and 2 with a D-A-D-π-D configuration, where phenothiazine is used as a central unit, triphenylamine is used as a terminal unit and TCBD and cyclohexa-2,5-diene-1,4-diylidene-expanded TCBD are used as an acceptor between the phenothiazine and triphenylamine units, as a small molecule donor along with PC 71 BM as an acceptor for solution processed bulk heterojunction solar cells. The variation of acceptors in the phenothiazine derivatives makes an exciting change in the photophysical and electrochemical properties, hole mobility and therefore photovoltaic performance. The optimized device based on phenothiazine 2 exhibited a high power conversion efficiency of 7.35% (J sc = 11.98 mA cm -2 , V oc = 0.99 V and FF = 0.62), while the device based on phenothiazine 1 showed a low PCE of 4.81% (J sc = 8.73 mA cm -2 , V oc = 0.95 V and FF = 0.58) after solvent vapour annealing (SVA) treatment. The higher value of power conversion efficiency of the 2 based devices irrespective of the processing conditions may be related to the broader absorption and lower band gap of 2 as compared to 1. The improvement in the SVA treated active layer may be related to the enhanced crystallinity, molecular ordering and aggregation and shorter π-π stacking distance of the small molecule donors.

  18. 饱和蒸汽压式波纹管疏水阀热动元件实验研究%Experimental study on the saturated vapor pressure type thermostatic bellows for steam traps

    Institute of Scientific and Technical Information of China (English)

    李树勋; 徐登伟; 把桥环

    2011-01-01

    针对液体膨胀式波纹管蒸汽疏水阀排量不稳定、漏汽率高等问题,分析波纹管热动元件的热工特性.基于Riedel蒸汽压方程和气液平衡方程,建立饱和蒸汽压式波纹管热动元件的热力学模型,设计相应实验系统,进行不同参数下的实验研究.结果表明,饱和蒸汽压式波纹管热动元件伸长量是相变温度的单值函数,近似呈指数关系;采用不同混合比、刚度及填充方式,可调节疏水阀的排水过冷度.%In view of the instabilities of displacement and high steam leakage rate for the liquid-expansion type ther-mostatic bellows steam traps, thermodynamic characteristical of thermostatic bellows was analyzed. Based on the Riedel equation and the vapor-liquid equilibrium equation, thermodynamic model of the saturated vapor pressure type thermostatic bellows was set up, corresponding experimental system was designed, and experimental studies with different parameters was carried out. The experimental results agree well with the theoretical analysis. The results show that the elongation A/I of the saturated vapor pressure type thermostatic bellows is monodrome function of phase transition temperature T, and relationship between the elongation A/I and the phase change temperature t is an exponential function. The subcooled temperature of steam trap can be adjusted by using different mixture ratio, different bellows' stiffness and different sufficient attire method. This paper establishes theoretical and experimental foundation for improving the performance of thermostatic bellows steam traps.

  19. Theoretical and experimental study of mixed solvent electrolytes

    International Nuclear Information System (INIS)

    Cummings, P.T.; O'Connell, J.P.

    1990-01-01

    In the original proposal to study mixed solvent electrolyte solutions, four major goals were formulated: fundamental modeling of mixed solvent electrolytes using numerically solved integral equation approximation theories; evaluation of intermolecular pair potential models by computer simulation of selected systems for comparison with experiment and the numerical integral equation studies; development of fundamentally based correlations for the thermodynamic properties of mixed solvent electrolyte solutions using analytically solvable statistical mechanical models; and extension of experimental database on mixed solvent electrolytes by performing vapor-liquid equilibrium measurements on selected systems. This paper discusses the progress on these goals

  20. Comparison of sensor characteristics of three real-time monitors for organic vapors.

    Science.gov (United States)

    Hori, Hajime; Ishimatsu, Sumiyo; Fueta, Yukiko; Hinoue, Mitsuo; Ishidao, Toru

    2015-01-01

    Sensor characteristics and performance of three real-time monitors for volatile organic compounds (VOC monitor) equipped with a photo ionization detector (PID), a sensor using the interference enhanced reflection (IER) method and a semiconductor gas sensor were investigated for 52 organic solvent vapors designated as class 1 and class 2 of organic solvents by the Ordinance of Organic Solvent Poisoning Prevention in Japan. Test vapors were prepared by injecting each liquid solvent into a 50 l Tedlar® bag and perfectly vaporizing it. The vapor concentration was from one-tenth to twice the administrative control level for all solvents. The vapor concentration was measured with the monitors and a gas chromatograph equipped with a flame ionization detector simultaneously, and the values were compared. The monitor with the PID sensor could measure many organic vapors, but it could not detect some vapors with high ionization potential. The IER sensor could also detect many vapors, but a linear response was not obtained for some vapors. A semiconductor sensor could detect methanol that could not be detected by PID and IER sensors. Working environment measurement of organic vapors by real-time monitors may be possible, but sensor characteristics and their limitations should be known.

  1. Green solvents and technologies for oil extraction from oilseeds.

    Science.gov (United States)

    Kumar, S P Jeevan; Prasad, S Rajendra; Banerjee, Rintu; Agarwal, Dinesh K; Kulkarni, Kalyani S; Ramesh, K V

    2017-01-01

    Oilseeds are crucial for the nutritional security of the global population. The conventional technology used for oil extraction from oilseeds is by solvent extraction. In solvent extraction, n -hexane is used as a solvent for its attributes such as simple recovery, non-polar nature, low latent heat of vaporization (330 kJ/kg) and high selectivity to solvents. However, usage of hexane as a solvent has lead to several repercussions such as air pollution, toxicity and harmfulness that prompted to look for alternative options. To circumvent the problem, green solvents could be a promising approach to replace solvent extraction. In this review, green solvents and technology like aqueous assisted enzyme extraction are better solution for oil extraction from oilseeds. Enzyme mediated extraction is eco-friendly, can obtain higher yields, cost-effective and aids in obtaining co-products without any damage. Enzyme technology has great potential for oil extraction in oilseed industry. Similarly, green solvents such as terpenes and ionic liquids have tremendous solvent properties that enable to extract the oil in eco-friendly manner. These green solvents and technologies are considered green owing to the attributes of energy reduction, eco-friendliness, non-toxicity and non-harmfulness. Hence, the review is mainly focussed on the prospects and challenges of green solvents and technology as the best option to replace the conventional methods without compromising the quality of the extracted products.

  2. Petroleum Vapor Intrusion

    Science.gov (United States)

    One type of vapor intrusion is PVI, in which vapors from petroleum hydrocarbons such as gasoline, diesel, or jet fuel enter a building. Intrusion of contaminant vapors into indoor spaces is of concern.

  3. Validation of Hiriart equation to compute steam production by the lip pressure method; Validacion de la ecuacion de Hiriart para calculo de gasto de vapor por el metodo de presion de labio

    Energy Technology Data Exchange (ETDEWEB)

    Flores Armenta, Magaly [Gerencia de Proyectos Geotermoelectricos de la Comision Federal de Electricidad, Morelia (Mexico)

    1996-09-01

    Mainly in new geothermal wells, it is necessary to evaluate the production in a very fast, simple and not expensive way, to know the convenience to install surface equipment, such as silencers and separators, to drive the steam to the commercial gathering system. In practice, one of the most known methods is the lip pressure one, which requires a simple set of installations. The objective of this paper is to validate the steam flow rate calculated by the lip pressure method, with respect to the ASME method. The ASME method is known for its accuracy, and is done by measuring the steam and liquid after a high pressure separator, by an orifice plate of known diameter and a triangular weir. Results of the validation show up the feasibility of application of the lip pressure method by using a simple adjustment equation. Percentage of mistake results less than 1%, without any notable influence of the production enthalpy. That equation to be applied in a general case, is as follows: Q{nu} =(20642)(F*P*D{sup 2}/{radical}h-2000). For the particular case of the Los Azufres geothermal field, the equation is: Q{nu}= 810*P*D{sup 2} [Espanol] En los pozos geotermicos, principalmente en los nuevos, es necesario evaluar su produccion de manera rapida, sencilla y economica, para determinar la conveniencia de instalar equipo superficial, como separadores, silenciadores, etc., que permita la integracion del vapor al sistema comercial de generacion electrica. Para fines practicos uno de los metodos mas conocidos es el de presion de labio, que solo requiere un arreglo sencillo de instalaciones superficiales. En este documento se validan y ajustan los calculos de produccion de vapor por ese metodo de presion de labio, con respecto a las mediciones exactas efectuadas con el metodo ASME. Este ultimo es reconocido internacionalmente por su precision, y se lleva a cabo separando la mezcla obtenida en superficie en un recipiente a presion para medir el vapor a traves de una placa de orificio

  4. Accurate and stable equal-pressure measurements of water vapor transmission rate reaching the 10-6 g m-2 day-1 range

    Science.gov (United States)

    Nakano, Yoichiro; Yanase, Takashi; Nagahama, Taro; Yoshida, Hajime; Shimada, Toshihiro

    2016-10-01

    The water vapor transmission rate (WVTR) of a gas barrier coating is a critically important parameter for flexible organic device packaging, but its accurate measurement without mechanical stress to ultrathin films has been a significant challenge in instrumental analysis. At the current stage, no reliable results have been reported in the range of 10-6 g m-2 day-1 that is required for organic light emitting diodes (OLEDs). In this article, we describe a solution for this difficult, but important measurement, involving enhanced sensitivity by a cold trap, stabilized temperature system, pumped sealing and calibration by a standard conductance element.

  5. Development of Y-BA-CU-O Coated Conductor Using Metal Organic Chemical Vapor Deposition

    National Research Council Canada - National Science Library

    Selvamanickam, V

    2003-01-01

    .... The program includes a study of the a) influence of MOCVD processing conditions such as the flow rate of precursor vapors, precursor vaporization temperatures, oxygen partial pressure, reactor pressure, and the deposition temperature...

  6. Solvent and solute isotope effects in the aqueous solution of gases. Progress report, July 1, 1978-October 31, 1979

    International Nuclear Information System (INIS)

    Benson, B.B.; Krause, D. Jr.

    1979-10-01

    After developing a 3 He/ 4 He dual beam collection system for the mass spectrometer, the isotopic fractionation factor was determined for helium dissolved in H 2 O, D 2 O, seawater and ethanol. In all solvents the temperature dependence of the fractionation is different from that for a simple isotope vapor pressure effect. Addition of salt to H 2 O increases the fractionation, and the relative salting-out coefficient changes with temperature. A double isotopic effect occurs - the fractionations in D 2 O and H 2 O differ. In ethanol the fractionation is 25% less than in H 2 O

  7. Mechanical Analysis of an upscaled version of the Vaporizer (pressure vessel and circulation tubes) of the incineration pilot power plant TEMO-IPP.

    OpenAIRE

    Kerdi, Banan El

    2016-01-01

    To be able to upscale the TEMO-IPP incineration plant to a commercial incineration plant in Tripoli (about40 MW) critical components shall be verified by Finite Element Analysis with the tool Abaqus. The main critical component is the pressure vessel with about 100 bar pressure difference.

  8. A Lithium Vapor Box Divertor Similarity Experiment

    Science.gov (United States)

    Cohen, Robert A.; Emdee, Eric D.; Goldston, Robert J.; Jaworski, Michael A.; Schwartz, Jacob A.

    2017-10-01

    A lithium vapor box divertor offers an alternate means of managing the extreme power density of divertor plasmas by leveraging gaseous lithium to volumetrically extract power. The vapor box divertor is a baffled slot with liquid lithium coated walls held at temperatures which increase toward the divertor floor. The resulting vapor pressure differential drives gaseous lithium from hotter chambers into cooler ones, where the lithium condenses and returns. A similarity experiment was devised to investigate the advantages offered by a vapor box divertor design. We discuss the design, construction, and early findings of the vapor box divertor experiment including vapor can construction, power transfer calculations, joint integrity tests, and thermocouple data logging. Heat redistribution of an incident plasma-based heat flux from a typical linear plasma device is also presented. This work supported by DOE Contract No. DE-AC02-09CH11466 and The Princeton Environmental Institute.

  9. 40 CFR 52.255 - Gasoline transfer vapor control.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Gasoline transfer vapor control. 52.255... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California § 52.255 Gasoline transfer vapor control. (a) “Gasoline” means any petroleum distillate having a Reid vapor pressure of 4 pounds or greater...

  10. 40 CFR 52.787 - Gasoline transfer vapor control.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Gasoline transfer vapor control. 52.787... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Indiana § 52.787 Gasoline transfer vapor control. (a) Gasoline means any petroleum distillate having a Reid vapor pressure of 4 pounds or greater...

  11. Henry's Law vaporization studies and thermodynamics of einsteinium-253 metal dissolved in ytterbium

    International Nuclear Information System (INIS)

    Kleinschmidt, P.D.; Ward, J.W.; Matlack, G.M.; Haire, R.G.

    1984-01-01

    The cohesive energy of metallic einsteinium determines whether einsteinium is a trivalent or divalent metal. The enthalpy of sublimation, a measure of the cohesive energy, is calculated from the partial pressures of einsteinium over an alloy. The partial pressure of 253 Es has been measured over the range 470--870 K, using combined target and mass spectrometric Knudsen effusion techniques. An alloy was prepared with einsteinium dissolved in a ytterbium solvent to produce a very dilute solution. Partial pressure measurements on the alloy were amenable to the experimental technique and a data analysis using a Henry's law treatment of the data. Vapor pressure data are combined with an estimated crystal entropy S 0 298 and ΔC 0 /sub p/ for ytterbium, to produce enthalpy, entropy, and free energy functions from 298 to 1300 K. The vapor pressure of einsteinium in a dilute einsteinium--ytterbium alloy is described by the equation log P(atm) = -(6815 +- 216)/T+2.576 +- 0.337, from which we calculate for the enthalpy of sublimation of pure einsteinium ΔH 0 298 (second law) = 31.76 kcal/mol. The value of the enthalpy of sublimation is consistent with the conclusion that Es is a divalent metal

  12. Identification of Flavonoids (Quercetin, Gallic acid and Rutin from Catharanthus roseus Plant Parts using Deep Eutectic Solvent

    Directory of Open Access Journals (Sweden)

    Asma Nisar

    2017-02-01

    Full Text Available Green technology is the most important topic in the pharmaceutical field because it reduces the cost of medicines and minimizes the environmental impact of the field and is better for human health and safety. Green chemistry emphasizes that the solvent should be nontoxic, safe, cheap, green, readily available, recyclable, and biodegradable. Deep eutectic solvents, a new type of green solvent, have some renowned properties—for instance, high thermal stability, low vapor pressure, low cost, biodegradability, and high viscosity. In this study, deep eutectic solvents made up of choline chloride-glycerol (1:2 were used for the extraction and isolation of flavonoid (rutin, gallic acid, and quercetin from Catharanthus roseus plant parts, flower petal, leaves, stem, and root. The amounts of rutin and quercetin in flower petal are 29.46 and 6.51%, respectively, whereas, rutin, gallic acid, and quercetin amounts in leaves are 25.16, 8.57, and 10.47%, respectively. In stem the amounts of rutin, gallic acid, and quercetin are 13.02, 5.89, and 7.47%, respectively. In root, only quercetin has been obtained that is 13.49%. The HPLC is an analytical method, which was found to be an excellent technique for determination of rutin, gallic acid, and quercetin using deep eutectic solvent extraction from plant parts of Catharanthus roseus.

  13. Solvents and solvent effects in organic chemistry

    National Research Council Canada - National Science Library

    Reichardt, C; Welton, T

    2011-01-01

    .../guest complexation equilibria and reactions in biphasic solvent systems and neoteric solvents, respectively. More than 900 new references have been added, giving preference to review articles, and many older ones have been deleted. New references either replace older ones or are added to the end of the respective reference list of each chapter. Th...

  14. Analysis of air-, moisture- and solvent-sensitive chemical compounds by mass spectrometry using an inert atmospheric pressure solids analysis probe.

    Science.gov (United States)

    Mosely, Jackie A; Stokes, Peter; Parker, David; Dyer, Philip W; Messinis, Antonis M

    2018-02-01

    A novel method has been developed that enables chemical compounds to be transferred from an inert atmosphere glove box and into the atmospheric pressure ion source of a mass spectrometer whilst retaining a controlled chemical environment. This innovative method is simple and cheap to implement on some commercially available mass spectrometers. We have termed this approach inert atmospheric pressure solids analysis probe ( iASAP) and demonstrate the benefit of this methodology for two air-/moisture-sensitive chemical compounds whose characterisation by mass spectrometry is now possible and easily achieved. The simplicity of the design means that moving between iASAP and standard ASAP is straightforward and quick, providing a highly flexible platform with rapid sample turnaround.

  15. Effect of hydrostatic pressure, temperature, and solvent on the rate of the Diels-Alder reaction between 9,10-anthracenedimethanol and maleic anhydride

    Science.gov (United States)

    Kiselev, V. D.; Kornilov, D. A.; Anikin, O. V.; Latypova, L. I.; Konovalov, A. I.

    2017-03-01

    The rate of the reaction between 9,10-anthracenedimethanol and maleic anhydride in 1,4-dioxane, acetonitrile, trichloromethane, and toluene is studied at 25, 35, 45°C in the pressure range of 1-1772 bar. The rate constants, enthalpies, entropies and activation volumes are determined. It is shown that the rate of reaction with 9,10-anthracenedimethanol is approximately one order of magnitude higher than with 9-anthracenemethanol.

  16. The carbon monoxide stretching modes in camphor-bound cytochrome P-450cam. The effect of solvent conditions, temperature, and pressure.

    Science.gov (United States)

    Schulze, H; Ristau, O; Jung, C

    1994-09-15

    The effect of pH, monovalent cations, glycerol, temperature, and pressure on the carbonmonoxy (CO) stretching mode of camphor-bound cytochrome P-450cam (CYP 101) was studied. Two effects, band overlap and frequency shift, have been observed. The CO stretch infrared band located at about 1940 cm-1 is asymmetric because of the overlap of three bands at about 1931 cm-1, 1939 cm-1, and 1942 cm-1 with strongly different populations. Reducing the temperature or increasing the pressure leads to splitting the band or switching the asymmetry from the lower energy side to the higher energy side of the infrared band. The overlap of several CO stretch bands indicates conformational substates within the heme pocket. A frequency shift of the predominantly populated band is observed by changing all the parameters mentioned. The pH-induced frequency shift follows an S-shape with the pK at 6.2, which matches the pK observed for the pH-induced high-spin/low-spin transition. Conformational changes on the proximal heme side are suggested to be the origin. Monovalent cations at saturating concentration induce a small frequency shift depending on the ion radius. The potassium ion is the one that induces a CO stretch frequency with the highest wave-number while sodium and lithium (smaller radii) and rubidium and caesium ion (larger radii) have diminished values, which is supporting evidence for the special function of the potassium ion within the structure. Glycerol and hydrostatic pressure induce a red shift of the CO stretching frequency. Forced contact of the polar hydroxyl group of Thr252 of the I helix induced by pressure and indirectly by glycerol is suggested to change the CO dipole moment, reflecting in the decreased CO stretching frequency.

  17. High-pressure cloud point data for the system glycerol + olive oil + n-butane + AOT

    Directory of Open Access Journals (Sweden)

    J. P. Bender

    2008-09-01

    Full Text Available This work reports high-pressure cloud point data for the quaternary system glycerol + olive oil + n-butane + AOT surfactant. The static synthetic method, using a variable-volume view cell, was employed for obtaining the experimental data at pressures up to 27 MPa. The effects of glycerol/olive oil concentration and surfactant addition on the pressure transition values were evaluated in the temperature range from 303 K to 343 K. For the system investigated, vapor-liquid (VLE, liquid-liquid (LLE and vapor-liquid-liquid (VLLE equilibrium were recorded. It was experimentally observed that, at a given temperature and surfactant content, an increase in the concentration of glycerol/oil ratio led to a pronounced increase in the slope of the liquid-liquid coexistence curve. A comparison with results reported for the same system but using propane as solvent showed that much lower pressure transition values are obtained when using n-butane.

  18. Organic Solvent Tropical Report

    International Nuclear Information System (INIS)

    COWLEY, W.L.

    2000-01-01

    This report provides the basis for closing the organic solvent safety issue. Sufficient information is presented to conclude that risk posed by an unmitigated organic solvent fire is within risk evaluation guidelines

  19. Canyon solvent cleaning

    International Nuclear Information System (INIS)

    Reif, D.J.

    1986-01-01

    The HM Process at the Savannah River Plant (SRP) uses 7.5% tributylphosphate in n-paraffin as an extraction solvent. During use, the solvent is altered due to hydrolysis and radiolysis, forming materials that influence product losses, produce decontamination, and separation efficiencies. Laboratory studies to improve online solvent cleaning have shown the carbonate washing, although removing residual solvent activity does not remove binding ligands that hold fission products in the solvent. Treatment of solvent by an alumina adsorption process removes binding ligands and significantly improves recycle solvent performance. Both laboratory work defining a full-scale alumina adsorption process and the use of the process to clean HM Process first cycle solvent are presented

  20. Solvent wash solution

    International Nuclear Information System (INIS)

    Neace, J.C.

    1986-01-01

    This patent describes a process for removing diluent degradation products from a solvent extraction solution comprising an admixture of an organic extractant for uranium and plutonium and a non-polar organic liquid diluent, which has been used to recover uranium and plutonium from spent nuclear fuel. Comprising combining a wash solution consisting of: (a) water; and (b) a positive amount up to about, an including, 50 volume percent of at least one highly-polar water-miscible organic solvent, based on the total volume of the water and the highly-polar organic solvent, with the solvent extraction solution after uranium and plutonium values have been stripped from the solvent extraction solution, the diluent degradation products dissolving in the highly-polar organic solvent and the extractant and diluent of the extraction solution not dissolving in the highly-polar organic solvent, and separating the highly-polar organic solvent and the extraction solution to obtain a purified extraction solution