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Sample records for nonpolar liquids pressure

  1. Pressure effects on electron reactions and mobility in nonpolar liquids

    International Nuclear Information System (INIS)

    Holroyd, R.A.; Nishikawa, Masaru

    2002-01-01

    High pressure studies have elucidated the mechanisms of both electron reactions and electron transport in nonpolar liquids and provided information about the partial molar volumes of ions and electrons. The very large volume changes associated with electron attachment reactions have been explained as due to electrostriction by the ions, calculated with a continuum model, but modified to include the formation of a glassy shell of solvent molecules around the ion. The mobilities of electrons in cases where the electron is trapped can now be understood by comparing the trap cavity volume with the volume of electrostriction of the solvent around the cavity. In cases where the electron is quasi-free the compressibility dependent potential fluctuations are shown to be important. The isothermal compressibility is concluded to be the single most important parameter determining the behavior of excess electrons in liquids

  2. Electrophoretic Retardation of Colloidal Particles in Nonpolar Liquids

    Directory of Open Access Journals (Sweden)

    Filip Strubbe

    2013-04-01

    Full Text Available We have measured the electrophoretic mobility of single, optically trapped colloidal particles, while gradually depleting the co-ions and counterions in the liquid around the particle by applying a dc voltage. This is achieved in a nonpolar liquid, where charged reverse micelles act as co-ions and counterions. By increasing the dc voltage, the mobility first increases when the concentrations of co-ions and counterions near the particle start to decrease. At sufficiently high dc voltage (around 2 V, the mobility reaches a saturation value when the co-ions and counterions are fully separated. The increase in mobility is larger when the equilibrium ionic strength is higher. The dependence of the experimental data on the equilibrium ionic strength and on the applied voltage is in good agreement with the standard theory of electrophoretic retardation, assuming that the bare particle charge remains constant. This method is useful for studying the electrophoretic retardation effect and charging mechanisms for nonpolar colloids, and it sheds light on previously unexplained particle acceleration in electronic ink devices.

  3. Equilibrium structures and flows of polar and nonpolar liquids in different carbon nanotubes

    Science.gov (United States)

    Abramyan, Andrey K.; Bessonov, Nick M.; Mirantsev, Leonid V.; Chevrychkina, Anastasiia A.

    2018-03-01

    Molecular dynamics (MD) simulations of equilibrium structures and flows of polar water and nonpolar methane confined by single-walled carbon nanotubes (SWCNTs) with circular and square cross sections and bounding walls with regular graphene structure and random (amorphous) distribution of carbon atoms have been performed. The results of these simulations show that equilibrium structures of both confined liquids depend strongly on the shape of the cross section of SWCNTs, whereas the structure of their bounding walls has a minor influence on these structures. On contrary, the external pressure driven water and methane flows through above mentioned SWCNTs depend significantly on both the shape of their cross sections and the structure of their bounding walls.

  4. Single charging events on colloidal particles in a nonpolar liquid with surfactant

    Science.gov (United States)

    Schreuer, Caspar; Vandewiele, Stijn; Brans, Toon; Strubbe, Filip; Neyts, Kristiaan; Beunis, Filip

    2018-01-01

    Electrical charging of colloidal particles in nonpolar liquids due to surfactant additives is investigated intensively, motivated by its importance in a variety of applications. Most methods rely on average electrophoretic mobility measurements of many particles, which provide only indirect information on the charging mechanism. In the present work, we present a method that allows us to obtain direct information on the charging mechanism, by measuring the charge fluctuations on individual particles with a precision higher than the elementary charge using optical trapping electrophoresis. We demonstrate the capabilities of the method by studying the influence of added surfactant OLOA 11000 on the charging of single colloidal PMMA particles in dodecane. The particle charge and the frequency of charging events are investigated both below and above the critical micelle concentration (CMC) and with or without applying a DC offset voltage. It is found that at least two separate charging mechanisms are present below the critical micelle concentration. One mechanism is a process where the particle is stripped from negatively charged ionic molecules. An increase in the charging frequency with increased surfactant concentration suggests a second mechanism that involves single surfactant molecules. Above the CMC, neutral inverse micelles can also be involved in the charging process.

  5. Direct Evidence of Mg Incorporation Pathway in Vapor-Liquid-Solid Grown p-type Nonpolar GaN Nanowires

    OpenAIRE

    Patsha, Avinash; Amirthapandian, S.; Pandian, Ramanathaswamy; Bera, S.; Bhattacharya, Anirban; Dhara, Sandip

    2015-01-01

    Doping of III-nitride based compound semiconductor nanowires is still a challenging issue to have a control over the dopant distribution in precise locations of the nanowire optoelectronic devices. Knowledge of the dopant incorporation and its pathways in nanowires for such devices is limited by the growth methods. We report the direct evidence of incorporation pathway for Mg dopants in p-type nonpolar GaN nanowires grown via vapour-liquid-solid (VLS) method in a chemical vapour deposition te...

  6. Wetting behavior of nonpolar nanotubes in simple dipolar liquids for varying nanotube diameter and solute-solvent interactions

    Energy Technology Data Exchange (ETDEWEB)

    Rana, Malay Kumar; Chandra, Amalendu, E-mail: amalen@iitk.ac.in [Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016 (India)

    2015-01-21

    Atomistic simulations of model nonpolar nanotubes in a Stockmayer liquid are carried out for varying nanotube diameter and nanotube-solvent interactions to investigate solvophobic interactions in generic dipolar solvents. We have considered model armchair type single-walled nonpolar nanotubes with increasing radii from (5,5) to (12,12). The interactions between solute and solvent molecules are modeled by the well-known Lennard-Jones and repulsive Weeks-Chandler-Andersen potentials. We have investigated the density profiles and microscopic arrangement of Stockmayer molecules, orientational profiles of their dipole vectors, time dependence of their occupation, and also the translational and rotational motion of solvent molecules in confined environments of the cylindrical nanopores and also in their external peripheral regions. The present results of structural and dynamical properties of Stockmayer molecules inside and near atomistically rough nonpolar surfaces including their wetting and dewetting behavior for varying interactions provide a more generic picture of solvophobic effects experienced by simple dipolar liquids without any specific interactions such as hydrogen bonds.

  7. 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.

  8. Smooth perfluorinated surfaces with different chemical and physical natures: their unusual dynamic dewetting behavior toward polar and nonpolar liquids.

    Science.gov (United States)

    Cheng, Dalton F; Masheder, Benjamin; Urata, Chihiro; Hozumi, Atsushi

    2013-09-10

    The effects of surface chemistry and the mobility of surface-tethered functional groups of various perfluorinated surfaces on their dewetting behavior toward polar (water) and nonpolar (n-hexadecane, n-dodecane, and n-decane) liquids were investigated. In this study, three types of common smooth perfluorinated surfaces, that is, a perfluoroalkylsilane (heptadecafluoro-1,1,2,2-tetrahydrooctyl-dimethylchlorosilane, FAS17) monomeric layer, an amorphous fluoropolymer film (Teflon AF 1600), and a perfluorinated polyether (PFPE)-terminated polymer brush film (Optool DSX), were prepared and their static/dynamic dewetting characteristics were compared. Although the apparent static contact angles (CAs) of these surfaces with all probe liquids were almost identical to each other, the ease of movement of liquid drops critically depended on the physical (solidlike or liquidlike) natures of the substrate surface. CA hysteresis and substrate tilt angles (TAs) of all probe liquids on the Optool DSX surface were found to be much lower than those of Teflon AF1600 and FAS17 surfaces due to its physical polymer chain mobility at room temperature and the resulting liquidlike nature. Only 6.0° of substrate incline was required to initiate movement for a small drop (5 μL) of n-decane, which was comparable to the reported substrate TA value (5.3°) for a superoleophobic surface (θ(S) > 160°, textured perfluorinated surface). Such unusual dynamic dewetting behavior of the Optool DSX surface was also markedly enhanced due to the significant increase in the chain mobility of PFPE by moderate heating (70 °C) of the surface, with substrate TA reducing to 3.0°. CA hysteresis and substrate TAs rather than static CAs were therefore determined to be of greater consequence for the estimation of the actual dynamic dewetting behavior of alkane probe liquids on these smooth perfluorinated surfaces. Their dynamic dewettability toward alkane liquids is in the order of Optool DSX > Teflon AF1600

  9. Electron mobility in nonpolar liquids: the effect of molecular structure, temperature and electric field

    International Nuclear Information System (INIS)

    Schmidt, W.F.

    1977-01-01

    A survey is given on the mobility of excess electrons in liquid hydrocarbons and related compounds. It was found that the mobility is strongly influenced by the molecular structure of the liquid, by the temperature, and by the electric field strength. The mobility in hydrocarbons increases as the shape of the molecule approaches a sphere. The temperature coefficient is positive in most liquids over a limited temperature although exceptions have been observed in liquid methane. The field dependence of the mobility in high mobility liquids (>10 cm 2 V -1 s -1 ) showed a decrease of the mobility at higher field strengths while in low mobility liquids ( 2 V -1 s -1 ) it showed an increase. These results are discussed on the basis of the extended and the localized electron models. The predictions of these theories are compared with the experimental results and conclusions on the validity of the underlying assumptions are drawn. (author)

  10. Pressure sensor using liquid crystals

    Science.gov (United States)

    Parmar, Devendra S. (Inventor); Holmes, Harlan K. (Inventor)

    1994-01-01

    A pressure sensor includes a liquid crystal positioned between transparent, electrically conductive films (18 and 20), that are biased by a voltage (V) which induces an electric field (E) that causes the liquid crystal to assume a first state of orientation. Application of pressure (P) to a flexible, transparent film (24) causes the conductive film (20) to move closer to or farther from the conductive film (18), thereby causing a change in the electric field (E'(P)) which causes the liquid crystal to assume a second state of orientation. Polarized light (P.sub.1) is directed into the liquid crystal and transmitted or reflected to an analyzer (A or 30). Changes in the state of orientation of the liquid crystal induced by applied pressure (P) result in a different light intensity being detected at the analyzer (A or 30) as a function of the applied pressure (P). In particular embodiments, the liquid crystal is present as droplets (10) in a polymer matrix (12) or in cells (14) in a polymeric or dielectric grid (16) material in the form of a layer (13) between the electrically conductive films (18 and 20). The liquid crystal fills the open wells in the polymer matrix (12) or grid (16) only partially.

  11. High molecular weight non-polar hydrocarbons as pure model substances and in motor oil samples can be ionized without fragmentation by atmospheric pressure chemical ionization mass spectrometry.

    Science.gov (United States)

    Hourani, Nadim; Kuhnert, Nikolai

    2012-10-15

    High molecular weight non-polar hydrocarbons are still difficult to detect by mass spectrometry. Although several studies have targeted this problem, lack of good self-ionization has limited the ability of mass spectrometry to examine these hydrocarbons. Failure to control ion generation in the atmospheric pressure chemical ionization (APCI) source hampers the detection of intact stable gas-phase ions of non-polar hydrocarbon in mass spectrometry. Seventeen non-volatile non-polar hydrocarbons, reported to be difficult to ionize, were examined by an optimized APCI methodology using nitrogen as the reagent gas. All these analytes were successfully ionized as abundant and intact stable [M-H](+) ions without the use of any derivatization or adduct chemistry and without significant fragmentation. Application of the method to real-life hydrocarbon mixtures like light shredder waste and car motor oil was demonstrated. Despite numerous reports to the contrary, it is possible to ionize high molecular weight non-polar hydrocarbons by APCI, omitting the use of additives. This finding represents a significant step towards extending the applicability of mass spectrometry to non-polar hydrocarbon analyses in crude oil, petrochemical products, waste or food. Copyright © 2012 John Wiley & Sons, Ltd.

  12. Relaxation phenomena of polar non-polar liquid mixtures under low ...

    Indian Academy of Sciences (India)

    der high-frequency electric field have gained much importance to study the structure as ... Purohit et al [1,2] and Srivastava and Srivastava [3] had measured the real ε¼ ... The cell containing the experimental liquid in a given solvent .... due to inductive, mesomeric and electromeric effects of the substituent polar groups at-.

  13. On flotation separation of oxo-anions of transition metals by the use of fine-emulsified solutions of cationic collector in non-polar liquids

    International Nuclear Information System (INIS)

    Skrylev, L.D.; Purich, A.N.; Babinets, S.K.

    1980-01-01

    Experimentally shown is a principle possibility of flotation separation of oxo-anions of transition metals by the use of fine-emulsified solutions of cationic collector in non-polar liquids. Ammonium vanadate and sodium tuno.state solutions have been the objects of study. Hexadezilamine has been used as collector. The collector has been introduced in the form of hexadecylamine emulsions in n-decane, in tetrachloromethane or alcohol. Optimum pH value ranges are determined for separation processes

  14. Liquid crystalline phases in suspensions of pigments in non-polar solvents

    Science.gov (United States)

    Klein, Susanne; Richardson, Robert M.; Eremin, Alexey

    We will discuss colloid suspensions of pigments and compare their electro-optic properties with those of traditional dyed low molecular weight liquid crystal systems. There are several potential advantages of colloidal suspensions over low molecular weight liquid crystal systems: a very high contrast because of the high orientational order parameter of suspensions of rod shaped nano-particles, the excellent light fastness of pigments as compared to dyes and high colour saturations resulting from the high loading of the colour stuff. Although a weak `single-particle' electro-optic response can be observed in dilute suspensions, the response is very much enhanced when the concentration of the particles is sufficient to lead to a nematic phase. Excellent stability of suspensions is beneficial for experimental observation and reproducibility, but it is a fundamental necessity for display applications. We therefore discuss a method to achieve long term stability of dispersed pigments and the reasons for its success. Small angle X-ray scattering was used to determine the orientational order parameter of the suspensions as a function of concentration and the dynamic response to an applied electric field. Optical properties were investigated for a wide range of pigment concentrations. Electro-optical phenomena, such as field-induced birefringence and switching, were characterised. In addition, mixtures of pigment suspensions with small amounts of ferrofluids show promise as future magneto-optical materials.

  15. Influence of Nonpolar Substances on the Extraction Efficiency of Six Alkaloids in Zoagumhwan Investigated by Ultra Performance Liquid Chromatography and Photodiode Array Detection

    Directory of Open Access Journals (Sweden)

    Shijing Liu

    2012-11-01

    Full Text Available A reverse phase ultra performance liquid chromatography and photodiode array (UPLC-PDA detection method was established for the determination of six alkaloids in Zoagumhwan (ZGW, and further for investigating the influence of nonpolar substances on the extraction efficiency of these alkaloids. The method was based on a BEH C18 (50 mm × 2.1 mm, 1.7 μm column and mobile phase of aqueous phosphoric acid and acetonitrile including 0.05% buffer solution under gradient elution. ZGW samples of ZGW I, II, III and IV were obtained and prepared by pre-processing the crude materials of Coptidis rhizoma and Evodiae fructus using four technologies, namely direct water decoction, removal of nonpolar substances in Evodiae fructus by supercritical fluid extraction (SFE, removal of nonpolar substances in ZGW by SFE and removal of nonpolar substances in ZGW by steam distillation. The developed and validated UPLC-PDA method was precise, accurate and sensitive enough based on the facts that the six alkaloids showed good regression (r > 0.9998, the limit of detections and quantifications for six alkaloids were less than 28.8 and 94.5 ng/mL, respectively, and the recovery was in the range of 98.56%–103.24%. The sequence of the total contents of six alkaloids in these samples was ZGW II > ZGW IV > ZGW III > ZGW I. ZGW II, in which nonpolar substances, including essential oils, were firstly removed from Evodiae fructus by SFE, had the highest content of the total alkaloids, indicating that extraction efficiency of the total alkaloids could be remarkably increased after Evodiae fructus being extracted by SFE.

  16. Pressure transient in liquid lines

    International Nuclear Information System (INIS)

    Sun, J.G.; Wang, X.Q.

    1995-01-01

    The pressure surge that results from a step change of flow in liquid pipelines, commonly known as water hammer, was analyzed by an eigenfunction method. A differential-integral Pressure wave equation and a linearized velocity equation were derived from the equations of mass and momentum conservation. Waveform distortion due to viscous dissipation and pipe-wall elastic expansion is characterized by a dimensionless transmission number K. The pressure surge condition, which is mathematically singular, was used in the solution procedure. The exact solutions from numerical calculation of the differential-integral equation provide a complete Pressure transient in the pipe. The problems are also calculated With the general-purpose computer code COMMIX, which solves the exact mass conservation equation and Navier-Stokes equations. These solutions were compared with published experimental results, and agreement was good. The effect of turbulence on the pressure transient is discussed in the light of COMMIX calculational results

  17. Polarity and Nonpolarity of Ionic Liquids Viewed from the Rotational Dynamics of Carbon Monoxide.

    Science.gov (United States)

    Yasaka, Y; Kimura, Y

    2015-12-17

    The rotational dynamics of carbon monoxide (CO) in a molten salt, ionic liquids (ILs), and alkanes were investigated by (17)O NMR T1 measurements using labeled C(17)O. The molten salt and the studied ILs have the bis(trifluoromethanesulfonyl)imide anion ([NTf2](-)) in common. In hexane near room temperature, the rotational relaxation times are close to the values predicted from the slip boundary condition in the Stokes-Einstein-Debye (SED) theory. However, in contradiction to the theoretical prediction, the rotational relaxation times decrease as the value of η/T increases, where η and T are the viscosity and absolute temperature, respectively. In other alkanes and ILs used in this study, the rotational relaxation times are much faster than those predicted by SED, and show a unique dependence on the number of alkyl carbons. For the same value of η/T, the CO rotational relaxation times in ILs composed of short-alkyl-chain-length imidazolium cations (1-ethyl-3-methylimidazolium and 1-butyl-3-methylimidazolium) are close to those for a molten salt (Cs[NTf2]). On the other hand, the rotational relaxation times in ILs composed of long-chain-length imidazolium (1-methyl-3-octylimidazolium) and phosphonium (tributylmethylphosphonium and tetraoctylphosphonium) cations are much shorter than the SED predictions. This deviation from theory increases as the alkyl chain length increases. We also found that the rotational relaxation times in dodecane and squalane are similar to those in ILs with a similar number of alkyl carbons. These results are discussed in terms of heterogeneous solvation and in comparison with the translational diffusion of CO in ILs.

  18. Non-polar lipids characterization of Quinoa (Chenopodium quinoa) seed by comprehensive two-dimensional gas chromatography with flame ionization/mass spectrometry detection and non-aqueous reversed-phase liquid chromatography with atmospheric pressure chemical ionization mass spectrometry detection.

    Science.gov (United States)

    Fanali, Chiara; Beccaria, Marco; Salivo, Simona; Tranchida, Peter; Tripodo, Giusy; Farnetti, Sara; Dugo, Laura; Dugo, Paola; Mondello, Luigi

    2015-07-08

    A chemical characterization of major lipid components, namely, triacylglycerols, fatty acids and the unsaponifiable fraction, in a Quinoa seed lipids sample is reported. To tackle such a task, non-aqueous reversed-phase high-performance liquid chromatography with mass spectrometry detection was employed. The latter was interfaced with atmospheric pressure chemical ionization for the analysis of triacylglycerols. The main triacylglycerols (>10%) were represented by OLP, OOL and OLL (P = palmitoyl, O = oleoyl, L = linoleoyl); the latter was present in the oil sample at the highest percentage (18.1%). Furthermore, fatty acid methyl esters were evaluated by gas chromatography with flame ionization detection. 89% of the total fatty acids was represented by unsaturated fatty acid methyl esters with the greatest percentage represented by linoleic and oleic acids accounting for approximately 48 and 28%, respectively. An extensive characterization of the unsaponifiable fraction of Quinoa seed lipids was performed for the first time, by using comprehensive two-dimensional gas chromatography with dual mass spectrometry/flame ionization detection. Overall, 66 compounds of the unsaponifiable fraction were tentatively identified, many constituents of which (particularly sterols) were confirmed by using gas chromatography with high-resolution time-of-flight mass spectrometry. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Nonpolar solvation dynamics for a nonpolar solute in room ...

    Indian Academy of Sciences (India)

    Sandipa Indra

    2018-01-30

    Jan 30, 2018 ... Keywords. Solvation dynamics; nonpolar solvation; ionic liquid; molecular dynamics; linear response theory. 1. ... J. Chem. Sci. (2018) 130:3 spectrum of the excited probe molecule for imida- .... Therefore, the solute and the RTIL ions interact only ... interval of 30 ps from a long equilibrium trajectory of dura-.

  20. Polar and nonpolar organic polymer-based monolithic columns for capillary electrochromatography and high-performance liquid chromatography.

    Science.gov (United States)

    Rathnasekara, Renuka; Khadka, Shantipriya; Jonnada, Murthy; El Rassi, Ziad

    2017-01-01

    This review article is a continuation of the previous reviews on the area of monolithic columns covering the progress made in the field over the last couple of years from the beginning of the second half of 2014 until the end of the first half of 2016. It summarizes and evaluates the evolvement of both polar and nonpolar organic monolithic columns and their use in hydrophilic interaction LC and CEC and reversed-phase chromatography and RP-CEC. The review article discusses the results reported in a total of 62 references. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Changes in permittivity and density of molecular liquids under high pressure.

    Science.gov (United States)

    Kiselev, Vladimir D; Kornilov, Dmitry A; Konovalov, Alexander I

    2014-04-03

    We collected and analyzed the density and permittivity of 57 nonpolar and dipolar molecular liquids at different temperatures (143 sets) and pressures (555 sets). No equation was found that could accurately predict the change to polar liquid permittivity by the change of its density in the range of the pressures and temperatures tested. Consequently, the influence of high hydrostatic pressure and temperature on liquid permittivity may be a more complicated process compared to density changes. The pressure and temperature coefficients of permittivity can be drastically larger than the pressure and temperature coefficients of density, indicating that pressure and particularly temperature significantly affect the structure of molecular liquids. These changes have less influence on the density change but can strongly affect the permittivity change. The clear relationship between the tangent and secant moduli of the permittivity curvatures under pressure for various molecular liquids at different temperatures was obtained, from which one can calculate the Tait equation coefficients from the experimental values of the pressure influence on the permittivity at ambient pressure.

  2. Atmospheric pressure chemical ionization studies of non-polar isomeric hydrocarbons using ion mobility spectrometry and mass spectrometry with different ionization techniques

    Science.gov (United States)

    Borsdorf, H.; Nazarov, E. G.; Eiceman, G. A.

    2002-01-01

    The ionization pathways were determined for sets of isomeric non-polar hydrocarbons (structural isomers, cis/trans isomers) using ion mobility spectrometry and mass spectrometry with different techniques of atmospheric pressure chemical ionization to assess the influence of structural features on ion formation. Depending on the structural features, different ions were observed using mass spectrometry. Unsaturated hydrocarbons formed mostly [M - 1]+ and [(M - 1)2H]+ ions while mainly [M - 3]+ and [(M - 3)H2O]+ ions were found for saturated cis/trans isomers using photoionization and 63Ni ionization. These ionization methods and corona discharge ionization were used for ion mobility measurements of these compounds. Different ions were detected for compounds with different structural features. 63Ni ionization and photoionization provide comparable ions for every set of isomers. The product ions formed can be clearly attributed to the structures identified. However, differences in relative abundance of product ions were found. Although corona discharge ionization permits the most sensitive detection of non-polar hydrocarbons, the spectra detected are complex and differ from those obtained with 63Ni ionization and photoionization. c. 2002 American Society for Mass Spectrometry.

  3. Pressure sensor for high-temperature liquids

    International Nuclear Information System (INIS)

    Forster, G.A.

    1978-01-01

    A pressure sensor for use in measuring pressures in liquid at high temperatures, especially such as liquid sodium or liquid potassium, comprises a soft diaphragm in contact with the liquid. The soft diaphragm is coupled mechanically to a stiff diaphragm. Pressure is measured by measuring the displacement of both diaphragms, typically by measuring the capacitance between the stiff diaphragm and a fixed plate when the stiff diaphragm is deflected in response to the measured pressure through mechanical coupling from the soft diaphragm. Absolute calibration is achieved by admitting gas under pressure to the region between diaphragms and to the region between the stiff diaphragm and the fixed plate, breaking the coupling between the soft and stiff diaphragms. The apparatus can be calibrated rapidly and absolutely

  4. Studying the response of CR-39 to radon in non-polar liquids above water by Monte Carlo simulation and measurement

    International Nuclear Information System (INIS)

    Rezaie, Mohammad Reza; Sohrabi, Mehdi; Negarestani, Ali

    2013-01-01

    The application of CR-39 has been extensive for measurement of radon and progeny in air of dwellings, but limited as regards to measurements of radon in water. In this paper, a new method is introduced for efficient measurement of radon in water by registering alpha particle tracks in a CR-39 detector placed in a non-polar medium such as cyclohexane, hexane and olive oil when each mixed with water, then separated and fixed above water, as a two-phase media. The method introduced here is however different from the widely used liquid - liquid extraction technique by liquid scintillation spectrometry since it is a passive detection method (CR-39) in a non-polar liquid with enhanced absorption of radon in the liquid, it has a capability for long sample counting to decrease the minimum detection limit (MDL), it does not require sophisticated low light counting systems, and it has the potential for simultaneous measurements of large number of samples for large-scale applications. It also has a low cost and is readily available. A new Monte Carlo calculation of energy-distance travelled by alphas from radon and progeny in a medium was also investigated. The sensitivity of CR-39 detector to radon and progeny in water was determined under two conditions; in a single-phase and two-phase media. In a single-phase medium, CR-39 is directly placed either in air, water, cyclohexane, hexane or olive oil. When CR-39 is placed directly in water, its sensitivity is (2.4 ± 0.1) × 10 −4 (track/cm 2 )/(Bq.d/m 3 ). In the two-phase media, CR-39 is placed either in cyclohexane, hexane or olive oil when each is fixed above water. The sensitivities in the two-phase media are significantly enhanced and are respectively (1.98 ± 0.10) × 10 −2 , (2.8 ± 0.15) × 10 −2 and (2.86 ± 0.15) × 10 −2 (track/cm 2 )/(Bq.d/m 3 ). The sensitivies are about 76, 82 and 110 times more than that of when CR-39 is directly placed in water. The new method is a novel alternative for radon

  5. Solid-Phase Microextraction Coupled to Capillary Atmospheric Pressure Photoionization-Mass Spectrometry for Direct Analysis of Polar and Nonpolar Compounds.

    Science.gov (United States)

    Mirabelli, Mario F; Zenobi, Renato

    2018-04-17

    A novel capillary ionization source based on atmospheric pressure photoionization (cAPPI) was developed and used for the direct interfacing between solid-phase microextraction (SPME) and mass spectrometry (MS). The efficiency of the source was evaluated for direct and dopant-assisted photoionization, analyzing both polar (e.g., triazines and organophosphorus pesticides) and nonpolar (polycyclic aromatic hydrocarbons, PAHs) compounds. The results show that the range of compound polarity, which can be addressed by direct SPME-MS can be substantially extended by using cAPPI, compared to other sensitive techniques like direct analysis in real time (DART) and dielectric barrier discharge ionization (DBDI). The new source delivers a very high sensitivity, down to sub parts-per-trillion (ppt), making it a viable alternative when compared to previously reported and less comprehensive direct approaches.

  6. Impact of water dilution and cation tail length on ionic liquid characteristics: Interplay between polar and non-polar interactions

    International Nuclear Information System (INIS)

    Hegde, Govind A.; Bharadwaj, Vivek S.; Kinsinger, Corey L.; Schutt, Timothy C.; Pisierra, Nichole R.; Maupin, C. Mark

    2016-01-01

    The recalcitrance of lignocellulosic biomass poses a major challenge that hinders the economical utilization of biomass for the production of biofuel, plastics, and chemicals. Ionic liquids have become a promising solvent that addresses many issues in both the pretreatment process and the hydrolysis of the glycosidic bond for the deconstruction of cellulosic materials. However, to make the use of ionic liquids economically viable, either the cost of ionic liquids must be reduced, or a less expensive solvent (e.g., water) may be added to reduce the overall amount of ionic liquid used in addition to reducing the viscosity of the binary liquid mixture. In this work, we employ atomistic molecular dynamics simulations to investigate the impact of water dilution on the overall liquid structure and properties of three imidazolium based ionic liquids. It is found that ionic liquid-water mixtures exhibit characteristics that can be grouped into two distinct regions, which are a function of the ionic liquid concentration. The trends observed in each region are found to correlate with the ordering in the local structure of the ionic liquid that arises from the dynamic interactions between the ion pairs. Simulation results suggest that there is a high level of local ordering in the molecular structure at high concentrations of ionic liquids that is driven by the aggregation of the cationic tails and the anion-water interactions. It is found that as the concentration of ionic liquids in the binary mixture is decreased, there is a point at which the competing self and cross interaction energies between the ionic liquid and water shifts away from a cation-anion dominated regime, which results in a significant change in the mixture properties. This break point, which occurs around 75% w/w ionic liquids, corresponds to the point at which water molecules percolate into the ionic liquid network disrupting the ionic liquids’ nanostructure. It is observed that as the cationic alkyl

  7. Viscosity of liquid sulfur under high pressure

    International Nuclear Information System (INIS)

    Terasaki, Hidenori; Kato, T; Funakoshi, K; Suzuki, A; Urakawa, S

    2004-01-01

    The viscosity of liquid sulfur up to 9.7 GPa and 1067 K was measured using the in situ x-ray radiography falling sphere method. The viscosity coefficients were found to range from 0.11 to 0.69 Pa s, and decreased continuously with increasing pressure under approximately constant homologous temperature conditions. The observed viscosity variation suggests that a gradual structural change occurs in liquid sulfur with pressure up to 10 GPa. The L-L' transition in liquid sulfur proposed by Brazhkin et al (1991 Phys. Lett. A 154 413) from thermobaric measurements has not been confirmed by the present viscometry

  8. Stir bar sorptive extraction and liquid chromatography-tandem mass spectrometry determination of polar and non-polar emerging and priority pollutants in environmental waters.

    Science.gov (United States)

    Aparicio, Irene; Martín, Julia; Santos, Juan Luis; Malvar, José Luis; Alonso, Esteban

    2017-06-02

    An analytical method based on stir bar sorptive extraction (SBSE) was developed and validated for the determination of environmental concern pollutants in environmental waters by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Target compounds include six water and oil repellents (perfluorinated compounds), four preservatives (butylated hydroxytoluene and three parabens), two plasticizers (bisphenol A and di(2-ethylhexyl)phthalate), seven surfactants (four linear alkylbenzene sulfonates, nonylphenol and two nonylphenol ethoxylates), a flame retardant (hexabromocyclododecane), four hormones, fourteen pharmaceutical compounds, an UV-filter (2-ethylhexyl 4-methoxycinnamate) and nine pesticides. To achieve the simultaneous extraction of polar and non-polar pollutants two stir bar coatings were tested, the classic polydimethylsiloxane (PDMS) coating and the novel ethylene glycol modified silicone (EG-silicone). The best extraction recoveries were obtained using EG-silicone coating. The effects of sample pH, volume and ionic strength and extraction time on extraction recoveries were evaluated. The analytical method was validated for surface water and tap water samples. The method quantification limits ranged from 7.0ngL -1 to 177ngL -1 . The inter-day precision, expressed as relative standard deviation, was lower than 20%. Accuracy, expressed as relative recovery values, was in the range from 61 to 130%. The method was applied for the determination of the 48 target compounds in surface and tap water samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Equipment for liquid metal pressure measurement

    International Nuclear Information System (INIS)

    Jung, J.

    1977-01-01

    Equipment is proposed for measuring liquid metal pressure in piping or a tank. An auxiliary piping is connected to the piping or tank at the measuring point. The auxiliary piping transports liquid metal to a container by means of an electromagnetic pump. The piping also houses an electromagnetic flow ratemeter connected to an electric comparator. The comparator and the electromagnetic pump are connected to the pump output generator. (Z.M.)

  10. 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.

  11. Nuclear reactor of pressurized liquid coolant type

    International Nuclear Information System (INIS)

    Costes, D.

    1976-01-01

    The reactor comprises a vertical concrete pressure vessel, a bell-housing having an open lower end and disposed coaxially with the interior of the pressure vessel so as to delimit therewith a space filled with gas under pressure for the thermal insulation of the internal vessel wall, a pressurizing device for putting the coolant under pressure within the bell-housing and comprising a volume of control gas in contact with a large free surface of coolant in order that an appreciable variation in volume of liquid displaced within the coolant circuit inside the bell-housing should correspond to a small variation in pressure of the control gas. 9 claims, 3 drawing figures

  12. YIELDS OF IONS AND EXCITED STATES IN NONPOLAR LIQUIDS EXPOSED TO X-RAYS OF 1 TO 30 KEV ENERGY

    International Nuclear Information System (INIS)

    HOLROYD, R.A.

    1999-01-01

    When x-rays from a synchrotron source are absorbed in a liquid, the x-ray energy (E x ) is converted by the photoelectric effect into the kinetic energy of the electrons released. For hydrocarbons, absorption by the K-electrons of carbon dominates. Thus the energy of the photoelectron (E pe ) is E x -E b , where E b is the K-shell binding energy of carbon. Additional electrons with energy equal to E b is released in the Auger process that fills the hole in the K-shell. These energetic electrons will produce many ionizations, excitations and products. The consequences of the high density of ionizations and excitations along the track of the photoelectron and special effects near the K-edge are examined here

  13. An on-line normal-phase high performance liquid chromatography method for the rapid detection of radical scavengers in non-polar food matrixes

    NARCIS (Netherlands)

    Zhang, Q.; Klift, van der E.J.C.; Janssen, H.G.; Beek, van T.A.

    2009-01-01

    An on-line method for the rapid pinpointing of radical scavengers in non-polar mixtures like vegetable oils was developed. To avoid problems with dissolving the sample, normal-phase chromatography on bare silica gel was used with mixtures of hexane and methyl tert-butyl ether as the eluent. The high

  14. Liquid abrasive pressure pot scoping tests report

    International Nuclear Information System (INIS)

    Archibald, K.E.

    1996-01-01

    The primary initiatives of the LITCO Decontamination Development group at the Idaho Chemical Process Plant (ICPP) are the development of methods to eliminate the use of sodium bearing decontamination chemicals and minimization of the amount of secondary waste generated during decontamination activities. In July of 1994, a Commerce Business Daily (CBD) announcement was issued by the INEL to determine commercial interest in the development of an in-situ liquid abrasive grit blasting system. As a result of the CBD announcement, Klieber ampersand Schulz issued an Expression of Interest letter which stated they would be interested in testing a prototype Liquid Abrasive Pressure Pot (LAPP). LITCO's Decontamination group and Kleiber ampersand Schulz entered into a Cooperative Research and Development Agreement (CRADA) in which the Decontamination Development group tested the prototype LAPP in a non-radioactive hot cell mockup. Test results are provided

  15. Pressure of two-dimensional Yukawa liquids

    International Nuclear Information System (INIS)

    Feng, Yan; Wang, Lei; Tian, Wen-de; Goree, J; Liu, Bin

    2016-01-01

    A simple analytic expression for the pressure of a two-dimensional Yukawa liquid is found by fitting results from a molecular dynamics simulation. The results verify that the pressure can be written as the sum of a potential term which is a simple multiple of the Coulomb potential energy at a distance of the Wigner–Seitz radius, and a kinetic term which is a multiple of the one for an ideal gas. Dimensionless coefficients for each of these terms are found empirically, by fitting. The resulting analytic expression, with its empirically determined coefficients, is plotted as isochores, or curves of constant area. These results should be applicable to monolayer dusty plasmas. (paper)

  16. Review on pressure swirl injector in liquid rocket engine

    Science.gov (United States)

    Kang, Zhongtao; Wang, Zhen-guo; Li, Qinglian; Cheng, Peng

    2018-04-01

    The pressure swirl injector with tangential inlet ports is widely used in liquid rocket engine. Commonly, this type of pressure swirl injector consists of tangential inlet ports, a swirl chamber, a converging spin chamber, and a discharge orifice. The atomization of the liquid propellants includes the formation of liquid film, primary breakup and secondary atomization. And the back pressure and temperature in the combustion chamber could have great influence on the atomization of the injector. What's more, when the combustion instability occurs, the pressure oscillation could further affects the atomization process. This paper reviewed the primary atomization and the performance of the pressure swirl injector, which include the formation of the conical liquid film, the breakup and atomization characteristics of the conical liquid film, the effects of the rocket engine environment, and the response of the injector and atomization on the pressure oscillation.

  17. Measurement of the differential pressure of liquid metals

    Science.gov (United States)

    Metz, H.J.

    1975-09-01

    This patent relates to an improved means for measuring the differential pressure between any two points in a process liquid metal coolant loop, wherein the flow of liquid metal in a pipe is opposed by a permanent magnet liquid metal pump until there is almost zero flow shown by a magnetic type flowmeter. The pressure producing the liquid metal flow is inferred from the rate of rotation of the permanent magnet pump. In an alternate embodiment, a differential pressure transducer is coupled to a process pipeline by means of high-temperature bellows or diaphragm seals, and a permanent magnet liquid metal pump in the high-pressure transmission line to the pressure transducer can be utilized either for calibration of the transducer or for determining the process differential pressure as a function of the magnet pump speed. (auth)

  18. Measurement of the differential pressure of liquid metals

    International Nuclear Information System (INIS)

    Metz, H.J.

    1975-01-01

    This patent relates to an improved means for measuring the differential pressure between any two points in a process liquid metal coolant loop, wherein the flow of liquid metal in a pipe is opposed by a permanent magnet liquid metal pump until there is almost zero flow shown by a magnetic type flowmeter. The pressure producing the liquid metal flow is inferred from the rate of rotation of the permanent magnet pump. In an alternate embodiment, a differential pressure transducer is coupled to a process pipeline by means of high-temperature bellows or diaphragm seals, and a permanent magnet liquid metal pump in the high-pressure transmission line to the pressure transducer can be utilized either for calibration of the transducer or for determining the process differential pressure as a function of the magnet pump speed

  19. Modification of encapsulation pressure of reverse micelles in liquid ethane.

    Science.gov (United States)

    Peterson, Ronald W; Nucci, Nathaniel V; Wand, A Joshua

    2011-09-01

    Encapsulation within reverse micelles dissolved in low viscosity fluids offers a potential solution to the slow tumbling problem presented by large soluble macromolecules to solution NMR spectroscopy. The reduction in effective macromolecular tumbling is directly dependent upon the viscosity of the solvent. Liquid ethane is of sufficiently low viscosity at pressures below 5000 psi to offer a significant advantage. Unfortunately, the viscosity of liquid ethane shows appreciable pressure dependence. Reverse micelle encapsulation in liquid ethane often requires significantly higher pressures, which obviates the potential advantages offered by liquid ethane over liquid propane. Addition of co-surfactants or co-solvents can be used to manipulate the minimum pressure required to obtain stable, well-behaved solutions of reverse micelles prepared in liquid ethane. A library of potential additives is examined and several candidates suitable for use with encapsulated proteins are described. Copyright © 2011 Elsevier Inc. All rights reserved.

  20. Method transfer from high-pressure liquid chromatography to ultra-high-pressure liquid chromatography. II. Temperature and pressure effects.

    Science.gov (United States)

    Åsberg, Dennis; Samuelsson, Jörgen; Leśko, Marek; Cavazzini, Alberto; Kaczmarski, Krzysztof; Fornstedt, Torgny

    2015-07-03

    The importance of the generated temperature and pressure gradients in ultra-high-pressure liquid chromatography (UHPLC) are investigated and compared to high-pressure liquid chromatography (HPLC). The drug Omeprazole, together with three other model compounds (with different chemical characteristics, namely uncharged, positively and negatively charged) were used. Calculations of the complete temperature profile in the column at UHPLC conditions showed, in our experiments, a temperature difference between the inlet and outlet of 16 °C and a difference of 2 °C between the column center and the wall. Through van't Hoff plots, this information was used to single out the decrease in retention factor (k) solely due to the temperature gradient. The uncharged solute was least affected by temperature with a decrease in k of about 5% while for charged solutes the effect was more pronounced, with k decreases up to 14%. A pressure increase of 500 bar gave roughly 5% increase in k for the uncharged solute, while omeprazole and the other two charged solutes gave about 25, 20 and 15% increases in k, respectively. The stochastic model of chromatography was applied to estimate the dependence of the average number of adsorption/desorption events (n) and the average time spent by a molecule in the stationary phase (τs) on temperature and pressure on peak shape for the tailing, basic solute. Increasing the temperature yielded an increase in n and decrease in τs which resulted in less skew at high temperatures. With increasing pressure, the stochastic modeling gave interesting results for the basic solute showing that the skew of the peak increased with pressure. The conclusion is that pressure effects are more pronounced for both retention and peak shape than the temperature effects for the polar or charged compounds in our study. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Liquid crystalline fiber optic colorimeter for hydrostatic pressure measurement

    Science.gov (United States)

    Wolinski, Tomasz R.; Bajdecki, Waldemar K.; Domanski, Andrzej W.; Karpierz, Miroslaw A.; Konopka, Witold; Nasilowski, T.; Sierakowski, Marek W.; Swillo, Marcin; Dabrowski, Roman S.; Nowinowski-Kruszelnicki, Edward; Wasowski, Janusz

    2001-08-01

    This paper presents results of tests performed on a fiber optic system of liquid crystalline transducer for hydrostatic pressure monitoring based on properties of colorimetry. The system employs pressure-induced deformations occurring in liquid crystalline (LC) cells configured in a homogeneous Frederiks geometry. The sensor is compared of a round LC cell placed inside a specially designed pressure chamber. As a light source we used a typical diode operating at red wavelength and modulated using standard techniques. The pressure transducer was connected to a computer with a specially designed interface built on the bas of advanced ADAM modules. Results indicate that the system offers high response to pressure with reduced temperature sensitivity and, depending on the LC cell used, can be adjusted for monitoring of low hydrostatic pressures up to 6 MPa. These studies have demonstrated the feasibility of fiber optic liquid crystal colorimeter for hydrostatic pressure sensing specially dedicated to pipe- lines, mining instrumentation, and process-control technologies.

  2. AsS melt under pressure: one substance, three liquids.

    Science.gov (United States)

    Brazhkin, V V; Katayama, Y; Kondrin, M V; Hattori, T; Lyapin, A G; Saitoh, H

    2008-04-11

    An in situ high-temperature--high-pressure study of liquid chalcogenide AsS by x-ray diffraction, resistivity measurements, and quenching from melt is presented. The obtained data provide direct evidence for the existence in the melt under compression of two transformations: one is from a moderate-viscosity molecular liquid to a high-viscosity nonmetallic polymerized liquid at P approximately 1.6-2.2 GPa; the other is from the latter to a low-viscosity metallic liquid at P approximately 4.6-4.8 GPa. Upon rapid cooling, molecular and metallic liquids crystallize to normal and high-pressure phases, respectively, while a polymerized liquid is easily quenched to a new AsS glass. General aspects of multiple phase transitions in liquid AsS, including relations to the phase diagram of the respective crystalline, are discussed.

  3. (Liquid + liquid) equilibria of {benzene + cyclohexane + two ionic liquids} at different temperature and atmospheric pressure

    International Nuclear Information System (INIS)

    Sakal, Salem A.; Shen, Chong; Li, Chun-xi

    2012-01-01

    Highlights: ► (Liquid + liquid) equilibrium for two quaternary and two ternary systems were measured. ► The components include cyclohexane, benzene, [MIM][BF4], [MIM][ClO4] and [MMIM][DMP]. ► The (liquid + liquid) equilibrium data can be well correlated by the NRTL model. ► Separation of benzene and cyclohexane by pure ILs and their mixtures were discussed. - Abstract: (Liquid + liquid) equilibrium data of the following ternary and quaternary systems at different temperatures and mass fractions of ionic liquids (ILs) were measured at atmospheric pressure, i.e., {cyclohexane + benzene + 1,3-dimethylimidazolium dimethylphosphate ([MMIM][DMP])} at 298.2 K, {cyclohexane + benzene + 1-methylimidazolium tetrafluoroborate ([MIM][BF 4 ])} at 338.2 K, {cyclohexane + benzene + [MIM][BF 4 ] + [MMIM][DMP]} at (298.2 and 313.2) K, and {cyclohexane + benzene + 1-methylimidazolium perchlorate [MIM][ClO 4 ] + [MMIM][DMP]} at 298.2 K. The results indicate that both selectivity and distribution factor of the IL mixture for benzene are lower than that of pure IL [MMIM][DMP] at a specified condition, and decrease with the increase of the mass fraction of [MIM][BF 4 ] or [MIM][ClO 4 ] in its mixture of [MMIM][DMP] and the mole fraction of benzene. The extremely high selectivity of [MIM][BF 4 ] and [MIM][ClO 4 ] for aromatic compounds as predicted by the COSMOS-RS model is not justified by the present experimental results, and on the contrary, they show a relatively lower selectivity and extraction capacity for benzene than [MMIM][DMP].

  4. Liquid return from gas pressurization of grouted waste

    International Nuclear Information System (INIS)

    Powell, W.J.; Benny, H.L.

    1994-05-01

    The ability to force pore liquids out of a simulated waste grout matrix using air pressure was measured. Specimens cured under various conditions were placed in a permeameter and subjected to increasing air pressure. The pressure was held constant for 24 hours and then stepped up until either liquid was released or 150 psi was reached. One specimen was taken to 190 psi with no liquid release. Permeability to simulated tank waste was then measured. Compressive strength was measured following these tests. This data is to assess the amount of fluid that might be released from grouted waste resulting from the buildup of radiolytically generated hydrogen and other gasses within the waste form matrix. A plot of the unconfined compressive strength versus breakthrough pressures identifies a region of ''good'' grout, which will resist liquid release

  5. Hydrodynamic pressure in a tank containing two liquids

    International Nuclear Information System (INIS)

    Tang, Yu.

    1992-01-01

    A study on the dynamic response of a tank containing two different liquids under seismic excitation is presented. Both analytical and numerical (FEM) methods are employed in the analysis. The results obtained by the two methods are in good agreement. The response functions examined include the hydrodynamic pressure, base shear and base moments. A simple approach that can be used to estimate the fundamental natural frequency of the tank-liquid system containing two liquids is proposed. This simple approach is an extension of the method used for estimating the frequency of a tank-liquid system containing only one liquid. This study shows that the dynamic response of a tank filled with two liquids is quite different from that of an identical tank filled with only one liquid

  6. Solids, liquids, and gases under high pressure

    Science.gov (United States)

    Mao, Ho-Kwang; Chen, Xiao-Jia; Ding, Yang; Li, Bing; Wang, Lin

    2018-01-01

    Pressure has long been recognized as a fundamental thermodynamic variable but its application was previously limited by the available pressure vessels and probes. The development of megabar diamond anvil cells and a battery of associated in-laboratory and synchrotron techniques at the turn of the century have opened a vast new window of opportunities. With the addition of the pressure dimension, we are facing a new world with an order of magnitude more materials to be discovered than all that have been explored at ambient pressure. Pressure drastically and categorically alters all elastic, electronic, magnetic, structural, and chemical properties, and pushes materials across conventional barriers between insulators and superconductors, amorphous and crystalline solids, ionic and covalent compounds, vigorously reactive and inert chemicals, etc. In the process, it reveals surprising high-pressure physics and chemistry and creates novel materials. This review describes the principles and methodology used to reach ultrahigh static pressure: the in situ probes, the physical phenomena to be investigated, the long-pursued goals, the surprising discoveries, and the vast potential opportunities. Exciting examples include the quest for metallic hydrogen, the record-breaking superconducting temperature of 203 K in HnS , the complication of "free-electron gas" alkali metals, the magnetic collapse in 3 d transition elements, the pressure-induced superconductivity from topological insulators, the novel stoichiometry in simple compounds, the interaction of nanoscience, the accomplishment of 750 GPa pressure, etc. These highlights are the integral results of technological achievements, specific measurements, and theoretical advancement; therefore, the same highlights will appear in different sections corresponding to these different aspects. Overall, this review demonstrates that high-pressure research is a new dimension in condensed-matter physics.

  7. Pressure effect on the structural transition of liquid Au

    International Nuclear Information System (INIS)

    Zhang Yanning; Wang Li; Wang Weimin; Liu Xiangfa; Tian Xuelei; Zhang Peng

    2004-01-01

    We present a molecular dynamics simulation within the framework of empirical tight-binding potential on the liquid structure of Au under different pressures during the rapid cooling process. The pair correlation function (PCF) and the pair analysis (PA) technique are used to reveal the structural characteristics of liquid Au under normal and high pressures. The split of the second peak of g(r) is associated with the glass transition at the cooling rate of 2.06x10 13 K/s under different pressures. The nearest distance is shortened under high pressures. High-pressure is in favor of FCC-type and BCC-type atomic clusters. The number of icosahedral structures increases in the high temperature region as pressure increase, while high-pressure is not preferable for icosahedra at low temperature. With the increase of the pressure, the possibility that the system forms crystalline structure is enhanced. The influence of a higher pressure on the microstructure of liquid metal is much clearer than that of a lower pressure

  8. Multiple scaling power in liquid gallium under pressure conditions

    Energy Technology Data Exchange (ETDEWEB)

    Li, Renfeng; Wang, Luhong; Li, Liangliang; Yu, Tony; Zhao, Haiyan; Chapman, Karena W.; Rivers, Mark L.; Chupas, Peter J.; Mao, Ho-kwang; Liu, Haozhe

    2017-06-01

    Generally, a single scaling exponent, Df, can characterize the fractal structures of metallic glasses according to the scaling power law. However, when the scaling power law is applied to liquid gallium upon compression, the results show multiple scaling exponents and the values are beyond 3 within the first four coordination spheres in real space, indicating that the power law fails to describe the fractal feature in liquid gallium. The increase in the first coordination number with pressure leads to the fact that first coordination spheres at different pressures are not similar to each other in a geometrical sense. This multiple scaling power behavior is confined within a correlation length of ξ ≈ 14–15 Å at applied pressure according to decay of G(r) in liquid gallium. Beyond this length the liquid gallium system could roughly be viewed as homogeneous, as indicated by the scaling exponent, Ds, which is close to 3 beyond the first four coordination spheres.

  9. Boiling point of volatile liquids at various pressures

    Directory of Open Access Journals (Sweden)

    Luisa Maria Valencia

    2017-07-01

    Full Text Available Water, under normal conditions, tends to boil at a “normal boiling temperature” at which the atmospheric pressure fixes the average amount of kinetic energy needed to reach its boiling point. Yet, the normal boiling temperature of different substances varies depending on their nature, for which substances like alcohols, known as volatile, boil faster than water under same conditions. In response to this phenomenon, an investigation on the coexistence of both gas and liquid phases of a volatile substance in a closed system was made, establishing vapor pressure as the determining tendency of a substance to vaporize, which increases exponentially with temperature until a critical point is reached. Since atmospheric pressure is fixed, the internal pressure of the system was varied to determine its relationship with vapor pressure and thus with the boiling point of the substance, concluding that the internal pressure and boiling point of a volatile liquid in a closed system are negatively proportional.

  10. Temperature and pressure dependent osmotic pressure in liquid sodium-cesium alloys

    International Nuclear Information System (INIS)

    Rashid, R.I.M.A.

    1987-01-01

    The evaluation of the osmotic pressure in terms of the concentration fluctuations of mixtures and the equations of state of the pure liquids is considered. The temperature and pressure dependent experimentally measured concentration-concentration correlations in the long wavelength limit of liquid sodium-cesium alloys are used to demonstrate the appreciable dependence of the temperature and pressure on the osmotic pressure as a function of concentration. Introducing interchange energies as functions of temperature and pressure, our analysis is consistent with the Flory model. Thus, a formalism for evaluating the state dependent osmotic pressure is developed and our numerical work is considered to be an extension of the calculations of Rashid and March in the sense that a temperature and pressure dependent interchange energy parameter that more closely parameterizes the state dependent concentration fluctuations in the liquid alloys, is used. (author)

  11. Warm Pressurant Gas Effects on the Liquid Hydrogen Bubble Point

    Science.gov (United States)

    Hartwig, Jason W.; McQuillen, John B.; Chato, David J.

    2013-01-01

    This paper presents experimental results for the liquid hydrogen bubble point tests using warm pressurant gases conducted at the Cryogenic Components Cell 7 facility at the NASA Glenn Research Center in Cleveland, Ohio. The purpose of the test series was to determine the effect of elevating the temperature of the pressurant gas on the performance of a liquid acquisition device. Three fine mesh screen samples (325 x 2300, 450 x 2750, 510 x 3600) were tested in liquid hydrogen using cold and warm noncondensible (gaseous helium) and condensable (gaseous hydrogen) pressurization schemes. Gases were conditioned from 0 to 90 K above the liquid temperature. Results clearly indicate a degradation in bubble point pressure using warm gas, with a greater reduction in performance using condensable over noncondensible pressurization. Degradation in the bubble point pressure is inversely proportional to screen porosity, as the coarsest mesh demonstrated the highest degradation. Results here have implication on both pressurization and LAD system design for all future cryogenic propulsion systems. A detailed review of historical heated gas tests is also presented for comparison to current results.

  12. A way for evaluating parameters of electron transport in non-polar molecular liquids derived from analysis of the trapped electron recombination kinetics

    International Nuclear Information System (INIS)

    Lukin, L.V.

    2012-01-01

    The geminate recombination kinetics of electron-ion pairs produced by high energy radiation in liquid hydrocarbons is considered in the two state model of electron transport. The purpose of the study is to relate the trapped electron transient optical absorption, observed in the pulse radiolysis experiments, to fundamental parameters of electron transport in liquid. It is shown that measurements of the half-life time and amplitude of the trapped electron decay curve allow one to find the electron life time in a localized state. - Highlights: ► A two state electron model is applied to geminate charge recombination. ► Time dependence of trapped electrons is computed for liquid isooctane and squalane. ► Electron decay kinetics depends on electron life time in a localized state. ► Key parameters of electron transport are found from the pulse radiolysis studies.

  13. Volatility of coal liquids at high temperatures and pressures

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, G M; Johnston, R H; Hwang, S C; Tsonopoulos, C

    1981-01-01

    The volatility of coal liquids has been experimentally determined at 700-880 F and about 2000 psia. These measurements were made in a flow apparatus to minimize thermal decomposition effects at high temperatures. Three coal liquids in mixture with Hat2, methane, and Hat2S were investigated. Measurements were also made up to 900 F on the vapor pressure of pure compounds found in coal liquids and on the equilibrium pressure of narrow coal liquid cuts. These data were used to develop a new method for the prediction of the critical point and the superatmospheric vapour pressures of aromatic fractions that is superior to the Maxwell-Bonnell correlation. The VLE data on coal liquids and some recent high-temperature VLE data on binaries of aromatics with Hat2 or methane were analyzed with a modified Chao-Seader correlation and a modified Redlich-Kwong equation of state. Both VLE correlations are shown to be equivalent in the prediction of the volatility of coal liquids, when the new vapour pressure procedure is used.

  14. Ultrasonic level sensors for liquids under high pressure

    Science.gov (United States)

    Zuckerwar, A. J.; Mazel, D. S.; Hodges, D. Y.

    1986-01-01

    An ultrasonic level sensor of novel design continuously measures the level of a liquid subjected to a high pressure (up to about 40 MPa), as is sometimes required for the effective transfer of the liquid. The sensor operates as a composite resonator fabricated from a standard high-pressure plug. A flat-bottom hole is machined into the plug along its center line. An ultrasonic transducer is bonded rigidly to the interior surface of the bottom wall, while the exterior surface is in contact with the liquid. Although the bottom wall is designed to satisfy the pressure code, it is still sufficiently thin to permit ready excitation of the axisymmetric plate modes of vibration. The liquid level is measured by a conventional pulse-echo technique. A prototype sensor was tested successfully in a 2300-l water vessel at pressures up to about 37 MPa. A spectral analysis of the transmitted pulse reveals that the flexural, extensional, thickness-shear, and radial plate modes are excited into vibration, but none of these appears to be significantly affected by the pressurization of the liquid.

  15. Liquid oxygen liquid acquisition device bubble point tests with high pressure lox at elevated temperatures

    Science.gov (United States)

    Jurns, J. M.; Hartwig, J. W.

    2012-04-01

    When transferring propellant in space, it is most efficient to transfer single phase liquid from a propellant tank to an engine. In earth's gravity field or under acceleration, propellant transfer is fairly simple. However, in low gravity, withdrawing single-phase fluid becomes a challenge. A variety of propellant management devices (PMDs) are used to ensure single-phase flow. One type of PMD, a liquid acquisition device (LAD) takes advantage of capillary flow and surface tension to acquire liquid. The present work reports on testing with liquid oxygen (LOX) at elevated pressures (and thus temperatures) (maximum pressure 1724 kPa and maximum temperature 122 K) as part of NASA's continuing cryogenic LAD development program. These tests evaluate LAD performance for LOX stored in higher pressure vessels that may be used in propellant systems using pressure fed engines. Test data shows a significant drop in LAD bubble point values at higher liquid temperatures, consistent with lower liquid surface tension at those temperatures. Test data also indicates that there are no first order effects of helium solubility in LOX on LAD bubble point prediction. Test results here extend the range of data for LOX fluid conditions, and provide insight into factors affecting predicting LAD bubble point pressures.

  16. Competition and coexistence of polar and non-polar states in Sr1-x Ca x TiO3: an investigation using pressure dependent Raman spectroscopy

    Science.gov (United States)

    Tyagi, Shekhar; Sharma, Gaurav; Sathe, Vasant G.

    2018-03-01

    The competition and cooperation between ferroelectric and anti-ferro-distortion (AFD) instabilities are studied using pressure dependent Raman spectroscopy on polycrystalline powder samples of Sr1-x Ca x TiO3(x  =  0.0, 0.06, 0.25, 0.35). For x  =  0.0 composition, a broad polar mode is detected in the Raman spectra above 6 GPa, while for x  =  0.06 composition, the polar modes appear well above 9 GPa where the AFD modes showed strong suppression. In x  =  0.25 and 0.35 composition, the application of small pressure resulted in the appearance of strong AFD modes suppressing the polar modes. At elevated pressures, re-entrant polar modes are observed along with the broad AFD modes and some new peaks are also observed, signifying the lowering of local symmetry. The reappearance of polar modes is found to be related to pressure induced symmetry disorder at local level, suggesting its electronic origin. The re-entrant polar modes observed at higher pressure values are found to be significantly broad and asymmetric in nature, signifying the development of ferroelectric micro regions/nano domains coexisting with AFD. The lower symmetry at local length scale provides a conducive atmosphere for coexisting AFD and FE instabilities.

  17. Correlation between the Inhibition of Positronium Formation by Scavenger Molecules, and Chemical Reaction Rate of Electrons with these Molecules in Nonpolar Liquids

    DEFF Research Database (Denmark)

    Levay, B.; Mogensen, O. E.

    1977-01-01

    a correlation between the inhibition coefficient and the chemical rate constant of electrons with scavenger molecules. We found that the dependence of the inhibition coefficient on the work function (VOo)f electrons in different liquids shows a very unusual behavior, similar to that recently found...... for the chemical rate constants of quasifree electrons with the same scavenger molecules. The inhibition coefficient as a function of Vo had a maximum for C2HsBr, while it increased monotonously with decreasing V, for CC14. The inhibition coefficient for C2H5Br in a 1:l molar tetramethylsilane......-n-tetradecane mixture was found to be greater than in both of the pure components. The clear correlation found between electron scavenging rate constants and positronium inhibition constitutes the severest test to date of the spur reaction model of positronium formation. The importance of the positron annihilation...

  18. Manipulating Liquids With Acoustic Radiation Pressure Phased Arrays

    Science.gov (United States)

    Oeftering, Richard C.

    1999-01-01

    High-intensity ultrasound waves can produce the effects of "Acoustic Radiation Pressure" (ARP) and "acoustic streaming." These effects can be used to propel liquid flows and to apply forces that can be used to move or manipulate floating objects or liquid surfaces. NASA's interest in ARP includes the remote-control agitation of liquids and the manipulation of bubbles and drops in liquid experiments and propellant systems. A high level of flexibility is attained by using a high-power acoustic phased array to generate, steer, and focus a beam of acoustic waves. This is called an Acoustic Radiation Pressure Phased Array, or ARPPA. In this approach, many acoustic transducer elements emit wavelets that converge into a single beam of sound waves. Electronically coordinating the timing, or "phase shift," of the acoustic waves makes it possible to form a beam with a predefined direction and focus. Therefore, a user can direct the ARP force at almost any desired point within a liquid volume. ARPPA lets experimenters manipulate objects anywhere in a test volume. This flexibility allow it to be used for multiple purposes, such as to agitate liquids, deploy and manipulate drops or bubbles, and even suppress sloshing in spacecraft propellant tanks.

  19. Liquid radioactive waste processing system for pressurized water reactor plants

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    This Standard sets forth design, construction, and performance requirements, with due consideration for operation, of the Liquid Radioactive Waste Processing System for pressurized water reactor plants for design basis inputs. For the purpose of this Standard, the Liquid Radioactive Waste Processing System begins at the interfaces with the reactor coolant pressure boundary and the interface valve(s) in lines from other systems, or at those sumps and floor drains provided for liquid waste with the potential of containing radioactive material; and it terminates at the point of controlled discharge to the environment, at the point of interface with the waste solidification system, and at the point of recycle back to storage for reuse

  20. Characterization of non-polar aromatic hydrocarbons in crude oil using atmospheric pressure laser ionization and Fourier transform ion cyclotron resonance mass spectrometry (APLI FT-ICR MS).

    Science.gov (United States)

    Schrader, Wolfgang; Panda, Saroj K; Brockmann, Klaus J; Benter, Thorsten

    2008-07-01

    We report on the successful application of the recently introduced atmospheric pressure laser ionization (APLI) method as a novel tool for the analysis of crude oil and its components. Using Fourier transform ion cyclotron resonance mass spectrometry, unambiguous determination of key compounds in this complex matrix with unprecedented sensitivity is presented.

  1. High pressure gas driven liquid metal MHD homopolar generator

    International Nuclear Information System (INIS)

    Itoh, Yasuyuki

    1988-01-01

    A liquid metal MHD homopolar generator is proposed to be used as a high repetition rate pulsed power supply. In the generator, the thermal energy stored in a high pressure gas (He) reservoir is rapidly converted into kinetic energy of a rotating liquid metal (NaK) cylinder which is contracted by a gas driven annular free piston. The rotational kinetic energy is converted into electrical energy by making use of the homopolar generator principle. The conversion efficiency is calculated to be 47% in generating electrical energy of 20 kJ/pulse (1.7 MW peak power) at a repetition rate of 7 Hz. From the viewpoint of energy storage, the high pressure gas reservoir with a charging pressure of 15 MPa is considered to ''electrically'' store the energy at a density of 10 MJ/m 3 . (author)

  2. Equation of state of liquid Indium under high pressure

    Directory of Open Access Journals (Sweden)

    Huaming Li

    2015-09-01

    Full Text Available We apply an equation of state of a power law form to liquid Indium to study its thermodynamic properties under high temperature and high pressure. Molar volume of molten indium is calculated along the isothermal line at 710K within good precision as compared with the experimental data in an externally heated diamond anvil cell. Bulk modulus, thermal expansion and internal pressure are obtained for isothermal compression. Other thermodynamic properties are also calculated along the fitted high pressure melting line. While our results suggest that the power law form may be a better choice for the equation of state of liquids, these detailed predictions are yet to be confirmed by further experiment.

  3. In Situ Raman Study of Liquid Water at High Pressure.

    Science.gov (United States)

    Romanenko, Alexandr V; Rashchenko, Sergey V; Goryainov, Sergey V; Likhacheva, Anna Yu; Korsakov, Andrey V

    2018-06-01

    A pressure shift of Raman band of liquid water (H 2 O) may be an important tool for measuring residual pressures in mineral inclusions, in situ barometry in high-pressure cells, and as an indicator of pressure-induced structural transitions in H 2 O. However, there was no consensus as to how the broad and asymmetric water Raman band should be quantitatively described, which has led to fundamental inconsistencies between reported data. In order to overcome this issue, we measured Raman spectra of H 2 O in situ up to 1.2 GPa using a diamond anvil cell, and use them to test different approaches proposed for the description of the water Raman band. We found that the most physically meaningful description of water Raman band is the decomposition into a linear background and three Gaussian components, associated with differently H-bonded H 2 O molecules. Two of these components demonstrate a pronounced anomaly in pressure shift near 0.4 GPa, supporting ideas of structural transition in H 2 O at this pressure. The most convenient approach for pressure calibration is the use of "a linear background + one Gaussian" decomposition (the pressure can be measured using the formula P (GPa) = -0.0317(3)·Δν G (cm -1 ), where Δν G represents the difference between the position of water Raman band, fitted as a single Gaussian, in measured spectrum and spectrum at ambient pressure).

  4. Investigation and Applications of In-Source Oxidation in Liquid Sampling-Atmospheric Pressure Afterglow Microplasma Ionization (LS-APAG) Source.

    Science.gov (United States)

    Xie, Xiaobo; Wang, Zhenpeng; Li, Yafeng; Zhan, Lingpeng; Nie, Zongxiu

    2017-06-01

    A liquid sampling-atmospheric pressure afterglow microplasma ionization (LS-APAG) source is presented for the first time, which is embedded with both electrospray ionization (ESI) and atmospheric pressure afterglow microplasma ionization (APAG) techniques. This ion source is capable of analyzing compounds with diverse molecule weights and polarities. An unseparated mixture sample was detected as a proof-of-concept, giving complementary information (both polarities and non-polarities) with the two ionization modes. It should also be noted that molecular mass can be quickly identified by ESI with clean and simple spectra, while the structure can be directly studied using APAG with in-source oxidation. The ionization/oxidation mechanism and applications of the LS-APAG source have been further explored in the analysis of nonpolar alkanes and unsaturated fatty acids/esters. A unique [M + O - 3H] + was observed in the case of individual alkanes (C 5 -C 19 ) and complex hydrocarbons mixture under optimized conditions. Moreover, branched alkanes generated significant in-source fragments, which could be further applied to the discrimination of isomeric alkanes. The technique also facilitates facile determination of double bond positions in unsaturated fatty acids/esters due to diagnostic fragments (the acid/ester-containing aldehyde and acid oxidation products) generated by on-line ozonolysis in APAG mode. Finally, some examples of in situ APAG analysis by gas sampling and surface sampling were given as well. Graphical Abstract ᅟ.

  5. The high pressure electronic control system in liquid chromatography

    International Nuclear Information System (INIS)

    Popescu, Stefan; Popeneciu, Gabriel; Toadere, Florin

    2002-01-01

    The Liquid Chromatography system can perform a wide variety of measurements and separations especially for the organic liquids, with maximum applications flexibility for less than half price of Gas Chromatography. The repeatability and accuracy of results in quantitative high pressure liquid chromatography are highly dependent on the reproducibility and accuracy of both integrated flow rate and mobile phase composition. Flow rate fluctuation leads to poor reproducibility in both integrated peak areas and retention times. Similarly, poor control of mobile phase composition will cause poor repeatability of retention time and peak heights. The our Solvent Delivery System SDS 200 is a single pump system which provides precise compensated flow rates from 0.01 to 10 mL/min, selectable upper pressure limits of 0 to 100 bar or 10 to 450 bar, and solvent compressibility correction. Ternary solvent system on-line mixing capability saves time, reduces solvent waste and provides more flexibility for difficult separations. The pump itself has two different displacement pistons which are used alternately on both suction and discharge, so that intake of the solvent are synchronous. The evacuated solvent from the two pump's chambers is mixed in the reference unit and then is supplied to the damping unit for flow ripple reduction. The SDS Electronic Module ensures the functions: controls the programmed flow rate, detects and shows the solvent pressure in solvent, supplies the step motor, measures and limits the solvent pressure. The control panel of SDS 200, contains a two-stages flow decimal programmer, a eight-positions knob for upper pressure limits, an alarm LED and a parallel port for connection to a PC system. (authors)

  6. Vapour pressure isotope effects in liquid hydrogen chloride

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, J.N.C.; Calado, J.C.G. (Instituto Superior Tecnico, Lisbon (Portugal)); Jancso, Gabor (Hungarian Academy of Sciences, Budapest (Hungary). Central Research Inst. for Physics)

    1992-08-10

    The difference between the vapour pressures of HCl and DCl has been measured over the temperature range 170-203 K by a differential manometric technique in a precision cryostat. In this range the vapour pressure of HCl is higher than that of DCl by 3.2% at 170 K, decreasing to 0.9% at 200 K. The reduced partition function ratios f[sub l]/f[sub g] derived from the vapour pressure data can be described by the equation ln(f[sub l]/f[sub g]) = (3914.57[+-]10)/T[sup 2] - (17.730[+-]0.055)/T. The experimentally observed H-D vapour pressure isotope effect, together with the values on the [sup 35]Cl-[sup 37]Cl isotope effect available in the literature, is interpreted in the light of the statistical theory of isotope effects in condensed systems by using spectroscopic data of the vapour and liquid phases. The results indicate that the rotation in liquid hydrogen chloride is hindered. Temperature-dependent force constants for the hindered translational and rotational motions were invoked in order to obtain better agreement between the model calculation and experiment. (author).

  7. 21 CFR 862.2260 - High pressure liquid chromatography system for clinical use.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false High pressure liquid chromatography system for... Clinical Laboratory Instruments § 862.2260 High pressure liquid chromatography system for clinical use. (a) Identification. A high pressure liquid chromatography system for clinical use is a device intended to separate...

  8. Hyperelastic pressure sensing with a liquid-embedded elastomer

    International Nuclear Information System (INIS)

    Park, Yong-Lae; Wood, Robert J; Majidi, Carmel; Kramer, Rebecca; Bérard, Phillipe

    2010-01-01

    A hyperelastic pressure transducer is fabricated by embedding silicone rubber with microchannels of conductive liquid eutectic gallium–indium. Pressing the surface of the elastomer with pressures in the range of 0–100 kPa will deform the cross-section of underlying channels and change their electric resistance by as much as 50%. Microchannels with dimensions as small as 25 µm are obtained with a maskless, soft lithography process that utilizes direct laser exposure. Change in electrical resistance is measured as a function of the magnitude and area of the surface pressure as well as the cross-sectional geometry, depth and relative lateral position of the embedded channel. These experimentally measured values closely match closed-form theoretical predictions derived from plane strain elasticity and contact mechanics

  9. Viscosity of komatiite liquid at high pressure and temperature

    Science.gov (United States)

    O Dwyer, L.; Lesher, C. E.; Wang, Y.

    2006-12-01

    The viscosities of komatiite liquids at high pressures and temperatures are being investigated by the in-situ falling sphere technique, using the T-25 multianvil apparatus at the GSECARS 13 ID-D beamline at the Advanced Photon Source, ANL. The refractory and fluid nature of komatiite and other ultramafic liquids relevant to the Earth's deep interior, presents unique challenges for this approach. To reach superliquidus temperatures we use a double reservoir configuration, where marker spheres are placed at the top of both a main melt reservoir and an overlying reservoir containing a more refractory composition. Using this approach, we have successfully measured the viscosity of a komatiite from Gorgona Island (GOR-94-29; MgO - 17.8 wt.%; NBO/T = 1.6) up to 6 GPa and 1900 K. Under isothermal conditions, viscosity increases with pressure, consistent with the depolymerized nature of the komatiite. At 1900 K, viscosity increases from 1.5 (+- 0.3) Pa s at 3.5 GPa to 3.4 (+- 0.3) Pa s at 6 GPa, corresponding to an activation volume of 2.2 cm3/mol. At high pressures, the viscosities of Gorgona Island komatiite melt are an order of magnitude higher than those measured by Liebske et al. (2005, EPSL, v. 240) for peridotite melt (MgO 37.1 wt.%; NBO/T = 2.5), and similar in magnitude to molten diopside (NBO/T = 2) (Reid et al. 2003, PEPI, v. 139). The positive pressure dependence is consistent with the reduction in interatomic space diminishing the free volume of the liquid as it is compressed. Above 6 GPa the free volume reduction may become less important with the production of high-coordinated network formers, as attributed to the reversal of the pressure dependence of viscosity for peridotite melt at ~8.5 GPa and diopside melt at ~10 GPa. Experiments at higher pressures are underway to determine if a similar viscosity maximum occurs for komatiite melt and whether its pressure is greater than 10 GPa, as suggested by the data for peridotite and diopside melts.

  10. Contamination of liquid oxygen by pressurized gaseous nitrogen

    Science.gov (United States)

    Zuckerwar, Allan J.; King, Tracy K.; Ngo, Kim Chi

    1989-01-01

    The penetration of pressurized gaseous nitrogen (GN2) into liquid oxygen (LOX) was investigated experimentally in the 7-inch High Temperature Tunnel, the pilot tunnel for the 8-foot High Temperature Tunnel (8'HTT) at Langley Research Center. A preliminary test using a nuclear monitor revealed the extent of the liquid nitrogen (LN2) build-up at the LOX interface as a function of GN2 pressure. Then an adaptation of the differential flash vaporization technique was used to determine the binary diffusivity of the LOX-LN2 system at a temperature of 90.2 K. The measured value D equals 0.000086 sq cm/s + or - 25 percent together with two prior measurements at lower temperatures revealed an excellent fit to the Arrhenius equation, yielding a pre-exponential factor D sub 0 equals 0.0452 sq cm/s and an activation enthalpy H equals 1.08 kcal/mol. At a pressure of 1700 psi and holding time of 15 min, the penetration of LN2 into LOX (to a 1 percent contamination level) was found to be 0.9 cm, indicating but minimal impact upon 8'HTT operations.

  11. Neutron Irradiation Tests of Pressure Transducers in Liquid Helium

    CERN Document Server

    Amand, J F; Casas-Cubillos, J; Thermeau, J P

    1999-01-01

    The superconducting magnets of the future Large Hadron Collider (LHC) at CERN will operate in pressurised superfluid helium (1 bar, 1.9 K). About 500 pressure transducers will be placed in the liquid helium bath for monitoring the filling and the pressure transients after resistive transitions. Their precision must remain better than 100 mbar at pressures below 2 bar and better than 5% for higher pressures (up to 20 bar), with temperatures ranging from 1.8 K to 300 K. All the tested transducers are based on the same principle: the fluid or gas is separated from a sealed reference vacuum by an elastic membrane; its deformation indicates the pressure. The transducers will be exposed to high neutron fluence (2 kGy, 1014 n/cm2 per year) during the 20 years of machine operation. This irradiation may induce changes both on the membranes characteristics (leakage, modification of elasticity) and on gauges which measure their deformations. To investigate these effects and select the transducer to be used in the LHC, a...

  12. Effect of mixing rule boundary conditions on high pressure (liquid + liquid) equilibrium prediction

    International Nuclear Information System (INIS)

    Hsieh, Min-Kang; Lin, Shiang-Tai

    2012-01-01

    Highlights: ► Prediction of LLE from the combined use of EOS and liquid model are examined. ► The mixing rule used affects the predicted pressure dependence of LLE. ► MHV1 mixing rule predicts decent LLE at low pressures. ► WS mixing rule predicts more accurate excess volume and LLE at high pressures. ► The hybrid of MHV1 and WS mixing rule gives overall the best predictions. - Abstract: We examine the prediction of high pressure (liquid + liquid) equilibrium (LLE) from the Peng–Robinson equation with three excess Gibbs free energy (G ex )-based mixing rules (MR): the first order modified Huron–Vidal (MHV1), the Wong–Sandler (WS), and a hybrid of these two (referred to as G ex B 2 ). These mixing rules differ by the boundary conditions used for determination of the temperature and composition dependence of parameters a and b in the PR EOS. The condition of matching the excess Gibbs free energy from the EOS at zero pressure to that from the G ex model, used in MHV1 and G ex B 2 MR, leads to a similar miscibility gap from PR EOS and the G ex model used. On the other hand, the condition of matching excess Helmholtz energy from the EOS at infinite pressure to that from the G ex model, used in the WS MR, shows remarkable deviations. The condition of quadratic composition dependence in the second virial coefficient (B 2 ), used in WS and G ex B 2 MR, allows for both positive and negative values in the molar excess volume. Depending on the mixture, either the increase or decrease of the miscibility gap with pressure can be observed when the WS or the G ex B 2 MR is used. The condition of linear combination of molecular sizes of each component used in the MHV1 MR, however, often leads to small, positive molar excess volumes. As a consequence, the predicted LLE from using the MHV1 MR are insensitive to pressure. Therefore, we find that the G ex B 2 mixing rule provides the best predictive power for the LLE over a wide range of temperature and pressure.

  13. Homogeneous nucleation in liquid nitrogen at negative pressures

    Energy Technology Data Exchange (ETDEWEB)

    Baidakov, V. G., E-mail: baidakov@itp.uran.ru; Vinogradov, V. E.; Pavlov, P. A. [Russian Academy of Sciences, Institute of Thermal Physics, Ural Branch (Russian Federation)

    2016-10-15

    The kinetics of spontaneous cavitation in liquid nitrogen at positive and negative pressures has been studied in a tension wave formed by a compression pulse reflected from the liquid–vapor interface on a thin platinum wire heated by a current pulse. The limiting tensile stresses (Δp = p{sub s}–p, where p{sub s} is the saturation pressure), the corresponding bubble nucleation frequencies J (10{sup 20}–10{sup 22} s{sup –1} m{sup –3}), and temperature induced nucleation frequency growth rate G{sub T} = dlnJ/dT have been experimentally determined. At T = 90 K, the limiting tensile stress was Δp = 8.3 MPa, which was 4.9 MPa lower than the value corresponding to the boundary of thermodynamic stability of the liquid phase (spinodal). The measurement results were compared to classical (homogeneous) nucleation theory (CNT) with and without neglect of the dependence of the surface tension of critical bubbles on their dimensions. In the latter case, the properties of new phase nuclei were described in terms of the Van der Waals theory of capillarity. The experimental data agree well with the CNT theory when it takes into account the “size effect.”.

  14. Colloidosomes formed by nonpolar/polar/nonpolar nanoball amphiphiles

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Hung-Yu; Sheng, Yu-Jane, E-mail: yjsheng@ntu.edu.tw, E-mail: hktsao@cc.ncu.edu.tw [Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan (China); Tu, Sheng-Hung [Department of Chemical and Materials Engineering, National Central University, Jhongli 320, Taiwan (China); Tsao, Heng-Kwong, E-mail: yjsheng@ntu.edu.tw, E-mail: hktsao@cc.ncu.edu.tw [Department of Chemical and Materials Engineering and Department of Physics, National Central University, Jhongli 320, Taiwan (China)

    2014-08-07

    Fullerene-based amphiphiles are able to form bilayer vesicles in aqueous solution. In this study, the self-assembly behavior of polymer-tethered nanoballs (NBs) with nonpolar/polar/nonpolar (n-p-n{sup ′}) motif in a selective solvent is investigated by dissipative particle dynamics. A model NB bears two hydrophobic polymeric arms (n{sup ′}-part) tethered on an extremely hydrophobic NB (n-part) with hydrophilic patch (p-part) patterned on its surface. Dependent on the hydrophobicity and length of tethered arms, three types of aggregates are exhibited, including NB vesicle, core-shell micelle, and segmented-worm. NB vesicles are developed for a wide range of hydrophobic arm lengths. The presence of tethered arms perturbs the bilayer structure formed by NBs. The structural properties including the order parameter, membrane thickness, and area density of the inner leaflet decrease with increasing the arm length. These results indicate that for NBs with longer arms, the extent of interdigitation in the membrane rises so that the overcrowded arms in the inner corona are relaxed. The transport and mechanical properties are evaluated as well. As the arm length grows, the permeability increases significantly because the steric bulk of tethered arms loosens the packing of NBs. By contrast, the membrane tension decreases owing to the reduction of NB/solvent contacts by the polymer corona. Although fusion can reduce membrane tension, NB vesicles show strong resistance to fusion. Moreover, the size-dependent behavior observed in small liposomes is not significant for NB vesicles due to isotropic geometry of NB. Our simulation results are consistent with the experimental findings.

  15. Charging and Screening in Nonpolar Solutions of Nonionizable Surfactants

    Science.gov (United States)

    Behrens, Sven

    2010-03-01

    Nonpolar liquids do not easily accommodate electric charges, but surfactant additives are often found to dramatically increase the solution conductivity and promote surface charging of suspended colloid particles. Such surfactant-mediated electrostatic effects have been associated with equilibrium charge fluctuations among reverse surfactant micelles and in some cases with the statistically rare ionization of individual surfactant molecules. Here we present experimental evidence that even surfactants without any ionizable group can mediate charging and charge screening in nonpolar oils, and that they can do so at surfactant concentrations well below the critical micelle concentration (cmc). Precision conductometry, light scattering, and Karl-Fischer titration of sorbitan oleate solutions in hexane, paired with electrophoretic mobility measurements on suspended polymer particles, reveal a distinctly electrostatic action of the surfactant. We interpret our observations in terms of a charge fluctuation model and argue that the observed charging processes are likely facilitated, but not limited, by the presence of ionizable impurities.

  16. 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.

  17. Elastic properties of crystalline and liquid gallium at high pressures

    Science.gov (United States)

    Lyapin, A. G.; Gromnitskaya, E. L.; Yagafarov, O. F.; Stal'Gorova, O. V.; Brazhkin, V. V.

    2008-11-01

    The elastic properties of gallium, such as the bulk modulus B, the shear modulus G, and the Poisson’s ratio σ, are investigated and the relative change in the volume is determined in the stability regions of the Ga I, Ga II, and liquid phases at pressures of up to 1.7 GPa. The observed lines of the Ga I-Ga II phase transition and the melting curves of the Ga I and Ga II phases are in good agreement with the known phase diagram of gallium; in this case, the coordinates of the Ga I-Ga II-melt triple point are determined to be 1.24 ± 0.40 GPa and 277 ± 2 K. It is shown that the Ga I-Ga II phase transition is accompanied by a considerable decrease in the moduli B (by 30%) and G (by 55%) and an increase in the density by 5.7%. The Poisson’s ratio exhibits a jump from typically covalent values of approximately 0.22-0.25 to values of approximately 0.32-0.33, which are characteristic of metals. The observed behavior of the elastic characteristics is described in the framework of the model of the phase transition from a “quasi-molecular” (partially covalent) metal state to a “normal” metal state. An increase in the Poisson’s ratio in the Ga I phase from 0.22 to 0.25 with an increase in the pressure can be interpreted as a decrease in the degree of covalence, i.e., the degree of spatial anisotropy of the electron density along the bonds, whereas the large value of the pressure derivative of the bulk modulus (equal to approximately 8) observed up to the transition to the Ga II phase or the melt is associated not only with the quasicovalent nature of the Ga I phase but also with the structural features. In view of the presence of seven neighbors for each gallium atom in the Ga I phase, the gallium lattice can be treated as a structure intermediate between typical open-packed and close-packed structures. Premelting effects, such as a flattening of the isothermal dependence of the shear modulus G( p) with increasing pressure and an increase in the slope of the

  18. Elastic properties of crystalline and liquid gallium at high pressures

    International Nuclear Information System (INIS)

    Lyapin, A. G.; Gromnitskaya, E. L.; Yagafarov, O. F.; Stal'gorova, O. V.; Brazhkin, V. V.

    2008-01-01

    The elastic properties of gallium, such as the bulk modulus B, the shear modulus G, and the Poisson's ratio σ, are investigated and the relative change in the volume is determined in the stability regions of the Ga I, Ga II, and liquid phases at pressures of up to 1.7 GPa. The observed lines of the Ga I-Ga II phase transition and the melting curves of the Ga I and Ga II phases are in good agreement with the known phase diagram of gallium; in this case, the coordinates of the Ga I-Ga II-melt triple point are determined to be 1.24 ± 0.40 GPa and 277 ± 2 K. It is shown that the Ga I-Ga II phase transition is accompanied by a considerable decrease in the moduli B (by 30%) and G (by 55%) and an increase in the density by 5.7%. The Poisson's ratio exhibits a jump from typically covalent values of approximately 0.22-0.25 to values of approximately 0.32-0.33, which are characteristic of metals. The observed behavior of the elastic characteristics is described in the framework of the model of the phase transition from a 'quasi-molecular' (partially covalent) metal state to a 'normal' metal state. An increase in the Poisson's ratio in the Ga I phase from 0.22 to 0.25 with an increase in the pressure can be interpreted as a decrease in the degree of covalence, i.e., the degree of spatial anisotropy of the electron density along the bonds, whereas the large value of the pressure derivative of the bulk modulus (equal to approximately 8) observed up to the transition to the Ga II phase or the melt is associated not only with the quasicovalent nature of the Ga I phase but also with the structural features. In view of the presence of seven neighbors for each gallium atom in the Ga I phase, the gallium lattice can be treated as a structure intermediate between typical open-packed and close-packed structures. Premelting effects, such as a flattening of the isothermal dependence of the shear modulus G(p) with increasing pressure and an increase in the slope of the isobaric

  19. Disintegration of liquid metals by low pressure water blasting

    International Nuclear Information System (INIS)

    Heshmatpour, B.; Copeland, G.L.

    1981-01-01

    The feasibility of disintegrating metals by a low cost system and subsequently incorporating them into grout mixtures has been demonstrated. A low pressure water blasting technique consisting of multiple nozzles and a converging-line jet stream was developed to disintegrate liquid metals and produce coarse metal powder and shot. Molten iron resulted in spherical shot, while copper, aluminum, and tin produced irregular shaped particles. The particle size was between 0.05 and 3 mm (0.002 and 0.1 in.), and about half the particles were smaller than 1 mm (0.04 in.) in all cases. The water consumption was rather low, while the production rate was relatively high. The method proved to be simple and reliable. The coarse metal powders were suspendable in grout fluids, indicating that they are probably disposable by the shale hydrofracture technique

  20. Pressurized liquid extraction of ginger (Zingiber officinale Roscoe) with bioethanol:

    DEFF Research Database (Denmark)

    Hu, Jiajin; Guo, Zheng; Glasius, Marianne

    2011-01-01

    To develop an efficient green extraction approach for recovery of bioactive compounds from natural plants, we examined the potential of pressurized liquid extraction (PLE) of ginger (Zingiber officinale Roscoe) with bioethanol/water as solvents. The advantages of PLE over other extraction...... approaches, in addition to reduced time/solvent cost, the extract of PLE showed a distinct constituent profile from that of Soxhlet extraction, with significantly improved recovery of diarylheptanoids, etc. Among the pure solvents tested for PLE, bioethanol yield the highest efficiency for recovering most...... constituents of gingerol-related compounds; while for a broad concentration spectrum of ethanol aqueous solutions, 70% ethanol gave the best performance in terms of yield of total extract, complete constituent profile and recovery of most gingerol-related components. PLE with 70% bioethanol operated at 1500...

  1. Atmospheric pressure plasma jets interacting with liquid covered tissue: touching and not-touching the liquid

    International Nuclear Information System (INIS)

    Norberg, Seth A; Johnsen, Eric; Tian, Wei; Kushner, Mark J

    2014-01-01

    In the use of atmospheric pressure plasma jets in biological applications, the plasma-produced charged and neutral species in the plume of the jet often interact with a thin layer of liquid covering the tissue being treated. The plasma-produced reactivity must then penetrate through the liquid layer to reach the tissue. In this computational investigation, a plasma jet created by a single discharge pulse at three different voltages was directed onto a 200 µm water layer covering tissue followed by a 10 s afterglow. The magnitude of the voltage and its pulse length determined if the ionization wave producing the plasma plume reached the surface of the liquid. When the ionization wave touches the surface, significantly more charged species were created in the water layer with H 3 O + aq , O 3 − aq , and O 2 − aq being the dominant terminal species. More aqueous OH aq , H 2 O 2aq , and O 3aq were also formed when the plasma plume touches the surface. The single pulse examined here corresponds to a low repetition rate plasma jet where reactive species would be blown out of the volume between pulses and there is not recirculation of flow or turbulence. For these conditions, N x O y species do not accumulate in the volume. As a result, aqueous nitrites, nitrates, and peroxynitrite, and the HNO 3aq and HOONO aq , which trace their origin to solvated N x O y , have low densities. (paper)

  2. Theoretical basis of oxygen pressure control in liquid Pb-Bi using YSZ

    International Nuclear Information System (INIS)

    Jung, S. H.; Hwang, I. S.; Park, B. K.

    2002-01-01

    To develop a liquid Pb-Bi cooled reactor, it is necessary to solve the structural material corrosion problem caused by Pb-Bi. This experiment examine the fundamental behaviors to practically test the oxide film formation on the surface of structural material known as solution of corrosion inhibition in liquid Pb-Bi. The corrosion inhibition through oxide film formation is to prevent metals from dissolving into liquid Pb-Bi though not forming coolants slug resulted from oxidation. In this paper, we examined the oxygen pressure controllability using YSZ in cover gas, and theoretically derived the relationship between oxygen cover gas pressure and dissolved oxygen in liquid Pb-Bi

  3. 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

  4. Effect of high pressure on the relaxation dynamics of glass-forming liquids

    Energy Technology Data Exchange (ETDEWEB)

    Paluch, M; Grzybowska, K; Grzybowski, A [Institute of Physics, Silesian University, ulica Uniwersytecka 4, 40-007 Katowice (Poland)

    2007-05-23

    A glass is usually formed by cooling a liquid at a rate sufficient to avoid crystallization. In the vicinity of the glass transition the structural relaxation time increases with lowering temperature in a non-Arrhenius fashion and the structural relaxation function reveals a non-Debye behaviour. However, liquid can be also vitrified by keeping it at a constant temperature and increasing the pressure. This pressure-induced transition to the glassy state is also accompanied by dramatic changes in the relaxation dynamics. Herein we discuss the behaviour of the structural relaxation times of glass-forming liquids and polymer melts under high pressure.

  5. Effect of high pressure on the relaxation dynamics of glass-forming liquids

    International Nuclear Information System (INIS)

    Paluch, M; Grzybowska, K; Grzybowski, A

    2007-01-01

    A glass is usually formed by cooling a liquid at a rate sufficient to avoid crystallization. In the vicinity of the glass transition the structural relaxation time increases with lowering temperature in a non-Arrhenius fashion and the structural relaxation function reveals a non-Debye behaviour. However, liquid can be also vitrified by keeping it at a constant temperature and increasing the pressure. This pressure-induced transition to the glassy state is also accompanied by dramatic changes in the relaxation dynamics. Herein we discuss the behaviour of the structural relaxation times of glass-forming liquids and polymer melts under high pressure

  6. Measurement of pressure fluctuation in gas-liquid two-phase vortex street

    International Nuclear Information System (INIS)

    Sun Zhiqiang; Sang Wenhui; Zhang Hongjian

    2009-01-01

    The pressure fluctuation in the wake is an important parameter to characterize the shedding process of gas-liquid two-phase Karman vortex street. This paper investigated such pressure fluctuations in a horizontal pipe using air and water as the tested fluid media. The dynamic signal representing the pressure fluctuation was acquired by the duct-wall differential pressure method. Results show that in the wake of the gas-liquid two-phase Karman vortex street, the frequency of the pressure fluctuation is linear with the Reynolds number when the volume void fraction is within the range of 18%. Moreover, the mean amplitude of the pressure fluctuation decreases with the volume void fraction, and the mean amplitude is larger at higher water flowrates under the same volume void fraction. These findings contribute to an in-depth understanding of the gas-liquid two-phase Karman vortex street.

  7. Liquid Hydrogen Propellant Tank Sub-Surface Pressurization with Gaseous Helium

    Science.gov (United States)

    Stephens, J. R.; Cartagena, W.

    2015-01-01

    A series of tests were conducted to evaluate the performance of a propellant tank pressurization system with the pressurant diffuser intentionally submerged beneath the surface of the liquid. Propellant tanks and pressurization systems are typically designed with the diffuser positioned to apply pressurant gas directly into the tank ullage space when the liquid propellant is settled. Space vehicles, and potentially propellant depots, may need to conduct tank pressurization operations in micro-gravity environments where the exact location of the liquid relative to the diffuser is not well understood. If the diffuser is positioned to supply pressurant gas directly to the tank ullage space when the propellant is settled, then it may become partially or completely submerged when the liquid becomes unsettled in a microgravity environment. In such case, the pressurization system performance will be adversely affected requiring additional pressurant mass and longer pressurization times. This series of tests compares and evaluates pressurization system performance using the conventional method of supplying pressurant gas directly to the propellant tank ullage, and then supplying pressurant gas beneath the liquid surface. The pressurization tests were conducted on the Engineering Development Unit (EDU) located at Test Stand 300 at NASA Marshall Space Flight Center (MSFC). EDU is a ground based Cryogenic Fluid Management (CFM) test article supported by Glenn Research Center (GRC) and MSFC. A 150 ft3 propellant tank was filled with liquid hydrogen (LH2). The pressurization system used regulated ambient helium (GHe) as a pressurant, a variable position valve to maintain flow rate, and two identical independent pressurant diffusers. The ullage diffuser was located in the forward end of the tank and was completely exposed to the tank ullage. The submerged diffuser was located in the aft end of the tank and was completely submerged when the tank liquid level was 10% or greater

  8. Experimental characterization of MHD pressure drop of liquid sodium flow under uniform magnetic field

    International Nuclear Information System (INIS)

    Kim, Hee Reyoung; Park, Jon Ho; Kim, Jong Man; Nam, Ho Yoon; Choi, Jong Hyun

    2001-01-01

    Magnetic field has many effects on the hydraulic pressure drop of fluids with high electrical conductivity. The theoretical solution about MHD pressure drop is sought for the uniform current density model with simplified physical geometry. Using the MHD equation in the rectangular duct of the sodium liquid flow under a transverse magnetic field, the electrical potential is sought in terms of the duct geometry and the electrical parameters of the liquid metal and duct material. By the product of the induced current inside the liquid metal and transverse magnetic field, the pressure gradients is found as a function of the duct size and the electrical conductivity of the liquid metal. The theoretically predicted pressure drop is compared with experimental results on the change of flow velocity and magnetic flux density

  9. Structure of liquid water at high pressures and temperatures

    CERN Document Server

    Eggert, J H; Loubeyre, P

    2002-01-01

    We report quantitatively accurate structure-factor and radial-distribution-function measurements of liquid water in a diamond-anvil cell (DAC) using x-ray diffraction. During the analysis of our diffraction data, we found it possible (and necessary) to also determine the density. Thus, we believe we present the first-ever diffraction-based determination of a liquid structure factor and equation of state in a DAC experiment.

  10. Thermodynamic properties of the liquid Hg-Tl alloys determined from vapour pressure measurements

    Directory of Open Access Journals (Sweden)

    Gierlotka W.

    2002-01-01

    Full Text Available The partial vapour pressure of mercury over liquid Hg-Tl liquid solutions were determined in the temperature range from 450 to 700 K by direct vapour pressure measurements carried out with the quartz gauge. From the measured ln pHg vs. T relationships activities of mercury were determined. Using Redlich-Kister formulas logarithms of the activity coefficients were described with the following equations: From which all thermodynamic functions in the solutions can be derived.

  11. Hydrodynamics in a pressurized cocurrent gas-liquid trickle bed reactor

    NARCIS (Netherlands)

    Wammes, Wino J.A.; Westerterp, K.R.

    1991-01-01

    The influence of gas density on total external liquid hold-up, pressure drop and gas-liquid interfacial area, under trickle-flow conditions, and the transition to pulse flow have been investigated with nitrogen or helium as the gas phase up to 7.5 MPa. It is concluded that the hydrodynamics depends

  12. Supercooled dynamics of glass-forming liquids and polymers under hydrostatic pressure

    Energy Technology Data Exchange (ETDEWEB)

    Roland, C M [Naval Research Laboratory, Chemistry Division, Code 6120, Washington, DC 20375-5342 (United States); Hensel-Bielowka, S [Institute of Physics, Silesian University, ul. Uniwersytecka 4, 40-007 Katowice (Poland); Paluch, M [Institute of Physics, Silesian University, ul. Uniwersytecka 4, 40-007 Katowice (Poland); Casalini, R [Naval Research Laboratory, Chemistry Division, Code 6120, Washington, DC 20375-5342 (United States); Chemistry Department, George Mason University, Fairfax, VA 22030 (United States)

    2005-06-01

    An intriguing problem in condensed matter physics is understanding the glass transition, in particular the dynamics in the equilibrium liquid close to vitrification. Recent advances have been made by using hydrostatic pressure as an experimental variable. These results are reviewed, with an emphasis in the insight provided into the mechanisms underlying the relaxation properties of glass-forming liquids and polymers.

  13. Supercooled liquid vapour pressures and related thermodynamic properties of polycyclic aromatic hydrocarbons determined by gas chromatography

    NARCIS (Netherlands)

    Haftka, J.J.H.; Parsons, J.R.; Govers, H.A.J.

    2006-01-01

    A gas chromatographic method using Kovats retention indices has been applied to determine the liquid vapour pressure (P-i), enthalpy of vaporization (Delta H-i) and difference in heat capacity between gas and liquid phase (Delta C-i) for a group of polycyclic aromatic hydrocarbons (PAHs). This group

  14. Tongue Pressure Modulation during Swallowing: Water versus Nectar-Thick Liquids

    Science.gov (United States)

    Steele, Catriona M.; Bailey, Gemma L.; Molfenter, Sonja M.

    2010-01-01

    Purpose: Evidence of tongue-palate pressure modulation during swallowing between thin and nectar-thick liquids stimuli has been equivocal. This mirrors a lack of clear evidence in the literature of tongue and hyoid movement modulation between nectar-thick and thin liquid swallows. In the current investigation, the authors sought to confirm whether…

  15. Purification Efficacy of Synthetic Cannabinoid Conjugates Using High-Pressure Liquid Chromatography

    Science.gov (United States)

    conducted using high-pressure liquid chromatography and gradient screens to determine the most effective means of purifying the SC:dark quencher conjugates...to obtain the highest yields and purity. The purity was verified using liquid chromatographycoupled mass spectroscopy and nuclear magnetic resonance.

  16. X-ray reflectivity measurements of liquid/solid interfaces under high hydrostatic pressure conditions.

    Science.gov (United States)

    Wirkert, Florian J; Paulus, Michael; Nase, Julia; Möller, Johannes; Kujawski, Simon; Sternemann, Christian; Tolan, Metin

    2014-01-01

    A high-pressure cell for in situ X-ray reflectivity measurements of liquid/solid interfaces at hydrostatic pressures up to 500 MPa (5 kbar), a pressure regime that is particularly important for the study of protein unfolding, is presented. The original set-up of this hydrostatic high-pressure cell is discussed and its unique properties are demonstrated by the investigation of pressure-induced adsorption of the protein lysozyme onto hydrophobic silicon wafers. The presented results emphasize the enormous potential of X-ray reflectivity studies under high hydrostatic pressure conditions for the in situ investigation of adsorption phenomena in biological systems.

  17. On the pressure evolution of dynamic properties of supercooled liquids

    Energy Technology Data Exchange (ETDEWEB)

    Drozd-Rzoska, Aleksandra; Rzoska, Sylwester J [Institute of Physics, Silesian University, ulica Uniwersytecka 4, 40-007 Katowice (Poland); Roland, C Michael [Naval Research Laboratory, Chemistry Division, Code 6120, Washington, DC 20375-5342 (United States); Imre, Attila R [KFKI Atomic Energy Research Institute, 1525 Budapest, POB 49 (Hungary)

    2008-06-18

    A pressure counterpart of the Vogel-Fulcher-Tammann (VFT) equation for representing the evolution of dielectric relaxation times or related dynamic properties is discussed: {tau}(P) = {tau}{sub 0}{sup P}exp[D{sub P}{delta}P(P{sub 0}-{delta}P)], where {delta}P = P-P{sub SL}, P{sub 0} is the ideal glass pressure estimation, D{sub P} is the pressure fragility strength coefficient, and the prefactor {tau}{sub 0}{sup P} is related to the relaxation time at the stability limit (P{sub SL}) in the negative pressure domain. The discussion is extended to the Avramov model (AvM) relation {tau}(T,P) = {tau}{sub 0}exp[{epsilon}(T{sub g}(P)/T){sup D}], supplemented with a modified Simon-Glatzel-type equation for the pressure dependence of the glass temperature (T{sub g}(P)), enabling an insight into the negative pressure region. A recently postulated (Dyre 2006 Rev. Mod. Phys. 78 953) comparison between the VFT and the AvM-type descriptions is examined, for both the temperature and the pressure paths. Finally, we address the question 'Does fragility depend on pressure?' from the title of Paluch M et al (2001 J. Chem. Phys. 114 8048) and propose a pressure counterpart for the 'Angell plot'.

  18. Liquid-metal pin-fin pressure drop by correlation in cross flow

    International Nuclear Information System (INIS)

    Wang, Zhibi; Kuzay, T.M.; Assoufid, L.

    1994-01-01

    The pin-fin configuration is widely used as a heat transfer enhancement method in high-heat-flux applications. Recently, the pin-fin design with liquid-metal coolant was also applied to synchrotron-radiation beamline devices. This paper investigates the pressure drop in a pin-post design beamline mirror with liquid gallium as the coolant. Because the pin-post configuration is a relatively new concept, information in literature about pin-post mirrors or crystals is rare, and information about the pressure drop in pin-post mirrors with liquid metal as the coolant is even more sparse. Due to this the authors considered the cross flow in cylinder-array geometry, which is very similar to that of the pin-post, to examine the pressure drop correlation with liquid metals over pin fins. The cross flow of fluid with various fluid characteristics or properties through a tube bank was studied so that the results can be scaled to the pin-fin geometry with liquid metal as the coolant. Study lead to two major variables to influence the pressure drop: fluid properties, viscosity and density, and the relative length of the posts. Correlation of the pressure drop between long and short posts and the prediction of the pressure drop of liquid metal in the pin-post mirror and comparison with an existing experiment are addressed

  19. Pressure-induced structural change of liquid InAs and the systematics of liquid III-V compounds

    International Nuclear Information System (INIS)

    Hattori, T.; Tsuji, K.; Miyata, Y.; Sugahara, T.; Shimojo, F.

    2007-01-01

    To understand the pressure-induced structural changes of liquid III-V compounds systematically, the pressure dependence of l-InAs was investigated using the synchrotron x-ray diffraction and an ab initio molecular-dynamics simulation (AIMD). The x-ray diffraction experiments revealed that the liquid changes its compression behavior from a nearly uniform type to a nonuniform one around 9 GPa. Corresponding to this change, the coordination number (China), which is maintained up to 9 GPa, markedly increases from 6.0 to 7.5. The AIMD simulation revealed that this change is related to the change in the pressure dependence of all three pair correlations. In particular, a marked change is observed in the As-As correlation; in the low-pressure region, the position of the first peak in g AsAs (r), r AsAs , increases while maintaining the CN AsAs , but in the high-pressure region, the r AsAs stops increasing and the CN AsAs begins to increase. The AIMD simulation also revealed that each partial structure of l-InAs is similar to that for the pure-element liquid with the same valence electron number. Upon compression, each partial structure approaches the respective one for a heavier element in the same group. These findings suggest that the structures of liquid compounds are locally controlled by the number of the valence electrons in each ion pair and that the change in each partial structure obeys the empirical rule that the high-pressure state resembles the ambient state of a heavier element in the same group. Comparing the pressure-induced structural change of l-InAs to those of other liquid III-V compounds (GaSb and InSb) has revealed that, although the high-pressure behaviors of these three liquids are apparently different, their structural changes are systematically understood by a common structural sequence. This systematics originates from the same effect on each partial structure between increasing the atomic number and the pressurization

  20. Pressure-volume-temperature gauging method experiment using liquid nitrogen under microgravity condition of parabolic flight

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Man Su; Park, Hana; Yoo, Don Gyu; Jeong, Sang Kwon [Cryogenic Engineering Laboratory, Department of Mechanical Engineering, KAIST, Daejeon (Korea, Republic of); Jung, Young Suk [Launcher Systems Development Team, Korea Aerospace Research Institute, Daejeon (Korea, Republic of)

    2014-06-15

    Measuring an exact amount of remaining cryogenic liquid propellant under microgravity condition is one of the important issues of rocket vehicle. A Pressure-Volume-Temperature (PVT) gauging method is attractive due to its minimal additional hardware and simple gauging process. In this paper, PVT gauging method using liquid nitrogen is investigated under microgravity condition with parabolic flight. A 9.2 litre metal cryogenic liquid storage tank containing approximately 30% of liquid nitrogen is pressurized by ambient temperature helium gas. During microgravity condition, the inside of the liquid tank becomes near-isothermal condition within 1 K difference indicated by 6 silicon diode sensors vertically distributed in the middle of the liquid tank. Helium injection with higher mass flow rate after 10 seconds of the waiting time results in successful measurements of helium partial pressure in the tank. Average liquid volume measurement error is within 11% of the whole liquid tank volume and standard deviation of errors is 11.9. As a result, the applicability of PVT gauging method to liquid.

  1. Pressure-volume-temperature gauging method experiment using liquid nitrogen under microgravity condition of parabolic flight

    International Nuclear Information System (INIS)

    Seo, Man Su; Park, Hana; Yoo, Don Gyu; Jeong, Sang Kwon; Jung, Young Suk

    2014-01-01

    Measuring an exact amount of remaining cryogenic liquid propellant under microgravity condition is one of the important issues of rocket vehicle. A Pressure-Volume-Temperature (PVT) gauging method is attractive due to its minimal additional hardware and simple gauging process. In this paper, PVT gauging method using liquid nitrogen is investigated under microgravity condition with parabolic flight. A 9.2 litre metal cryogenic liquid storage tank containing approximately 30% of liquid nitrogen is pressurized by ambient temperature helium gas. During microgravity condition, the inside of the liquid tank becomes near-isothermal condition within 1 K difference indicated by 6 silicon diode sensors vertically distributed in the middle of the liquid tank. Helium injection with higher mass flow rate after 10 seconds of the waiting time results in successful measurements of helium partial pressure in the tank. Average liquid volume measurement error is within 11% of the whole liquid tank volume and standard deviation of errors is 11.9. As a result, the applicability of PVT gauging method to liquid

  2. Characteristic densities of low- and high-pressure liquid SnI4

    International Nuclear Information System (INIS)

    Fuchizaki, Kazuhiro; Hamaya, Nozomu; Katayama, Yoshinori

    2013-01-01

    An in situ synchrotron x-ray absorption measurement was carried out to estimate the density of liquid SnI 4 . The characteristic densities of the low- and high-pressure liquids were found to be 4.6-4.7 and 4.9-5.0 g/cm 3 , respectively, and their region is separated at around 1.7 GPa. The difference in density, although a slight amount of 0.3-0.4 g/cm 3 , strongly suggests the existence of a weak but discontinuous phase transition at that pressure between the two liquid regions. (author)

  3. Determination of activity coefficients at infinite dilution of water and organic solutes (polar and non-polar) in the Ammoeng 100 ionic liquid at T = (308.15, 313.5, 323.15, and 333.15) K

    International Nuclear Information System (INIS)

    Reddy, Prashant; Chiyen, Kaleng J.; Deenadayalu, Nirmala; Ramjugernath, Deresh

    2011-01-01

    Highlights: → Activity coefficients at infinite dilution in the ionic liquid Ammoeng 100. → Twenty-seven solutes investigated at T = (308.15, 313.15, 323.15, and 333.15) K. → Ammoeng 100 not suited to aromatic/aliphatic and alkane/alcohol separations. - Abstract: Activity coefficients at infinite dilution (γ 13 ∞ ) have been determined for 27 solutes, viz. water and organic compounds (n-alkanes, cycloalkanes, 1-alkenes, 1-alkynes, aromatics, alcohols, and ketones) in the ionic liquid Ammoeng 100, by gas-liquid chromatography at four different temperatures, T = (308.15, 313.15, 323.15, and 333.15) K. Columns with different phase loadings (20 to 24)% of the ionic liquid in the stationary phase were employed to obtain γ 13 ∞ values at each temperature investigated. Partial molar excess enthalpies at infinite dilution (ΔH 1 E,∞ ) were calculated for the solutes from the temperature dependency relationship of the ln(γ 13 ∞ ) values for the temperature range in this study. The uncertainties in the determinations of the γ 13 ∞ and ΔH 1 E,∞ values are 6% and 10%, respectively. Selectivity values at infinite dilution (S ij ∞ ), have been computed from the γ 13 ∞ values to assess the potential candidacy of the Ammoeng 100 ionic liquid for the separation of alkane/alcohol mixtures. The results from this study have been compared to those available for several ionic liquids from previous investigations.

  4. Hydrodynamics in a cocurrent gas-liquid trickle bed at elevated pressures

    NARCIS (Netherlands)

    Wammes, W.J.A.; Middelkamp, J.; Huisman, W.J.; Huisman, W.J.; de Baas, C.M.; de Baas, C.M.; Westerterp, K.R.

    1991-01-01

    Data on design and operation of trickle beds at elevated pressures are scarce. In this study the influence of the gas density on the liquid holdup, the pressure drop, and the transition between trickle and pulse flow has been investigated in a tricklebed reactor operating up to 7.5 MPa and with

  5. Pressure loss of the annular air-liquid flow in vertical tufes

    Energy Technology Data Exchange (ETDEWEB)

    Schmal, M [Rio de Janeiro Univ. (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia; Cantalino, A [Rio de Janeiro Univ. (Brazil). Dept. de Engenharia Quimica

    1976-01-01

    In this work the pressure loss of the annular air-liquid flow in vertical tubes has been determined. Correlations are presented for the frictional pressure drop. The dimensional analysis and the following fluid systems were used for this determination: air-water, air-alcohol solutions and air-water and surfactants.

  6. Pressure-induced structural change in liquid GaIn eutectic alloy

    DEFF Research Database (Denmark)

    Yu, Q.; Ahmad, A. S.; Ståhl, Kenny

    2017-01-01

    Synchrotron x-ray diffraction reveals a pressure induced crystallization at about 3.4 GPa and a polymorphic transition near 10.3 GPa when compressed a liquid GaIn eutectic alloy up to ~13 GPa at room temperature in a diamond anvil cell. Upon decompression, the high pressure crystalline phase...

  7. Hydrostatic limits of Fluorinert liquids used for neutron and transport studies at high pressure

    International Nuclear Information System (INIS)

    Sidorov, V A; Sadykov, R A

    2005-01-01

    We determined the hydrostatic limits at room temperature for a number of Fluorinert liquids: FC70, FC75, FC77, FC84, FC87 and their mixtures. Pressure exceeding this limit produces pressure gradients in the sample, which are retained at low temperature. The maximum hydrostatic limit (2.3 GPa) was found for a (1:1) mixture of FC84/87

  8. 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

  9. High-pressure phase diagrams of liquid CO2 and N2

    Science.gov (United States)

    Boates, Brian; Bonev, Stanimir

    2011-06-01

    The phase diagrams of liquid CO2 and N2 have been investigated using first-principles theory. Both materials exhibit transitions to conducting liquids at high temperatures (T) and relatively modest pressures (P). Furthermore, both liquids undergo polymerization phase transitions at pressures comparable to their solid counterparts. The liquid phase diagrams have been divided into several regimes through a detailed analysis of changes in bonding, as well as structural and electronic properties for pressures and temperatures up to 200 GPa and 10 000 K, respectively. Similarities and differences between the high- P and T behavior of these fluids will be discussed. Calculations of the Hugoniot are in excellent agreement with available experimental data. Work supported by NSERC, LLNL, and the Killam Trusts. Prepared by LLNL under Contract DE-AC52-07NA27344.

  10. Internal pressure changes of liquid filled shipping casks due to thermal environment

    International Nuclear Information System (INIS)

    Jackson, J.E.

    1978-01-01

    A discussion of the significance of internal pressure calculations in liquid filled shipping casks subjected to a high temperature thermal environment is presented. Some basic thermodynamic relationships are introduced and discussed as they apply to the two-phase mixture problem encountered with liquid filled casks. A model of the liquid filled cask is developed and the assumptions and limitations of the mathematical model are discussed. A relationship is derived which can be used to determine internal cask pressures as a function of initial thermodynamic loading conditions, initial fluid volume ratio and final mixture temperature. The results for water/air filled casks are presented graphically in a parametric form. The curves presented are particularly useful for preliminary design verification purposes. A qualitative discussion of the use of the results from an error analysis aspect is presented. Some pressure calculation problems frequently seen by NRC for liquid filled cask designs are discussed

  11. Measurement and modeling of high-pressure (vapour + liquid) equilibria of (CO2 + alcohol) binary systems

    International Nuclear Information System (INIS)

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

    2010-01-01

    An apparatus based on a static-analytic method assembled in this work was utilized to perform high pressure (vapour + liquid) equilibria measurements with uncertainties estimated at 2 + 1-propanol), (CO 2 + 2-methyl-1-propanol), (CO 2 + 3-methyl-1-butanol), and (CO 2 + 1-pentanol) binary systems at temperatures of (313, 323, and 333) K, and at pressure range of (2 to 12) MPa. For all the (CO 2 + alcohol) systems, it was visually monitored to insure that there was no liquid immiscibility at the temperatures and pressures studied. The experimental results were correlated with the Peng-Robinson equation of state using the quadratic mixing rules of van der Waals with two adjustable parameters. The calculated (vapour + liquid) equilibria compositions were found to be in good agreement with the experimental values with deviations for the mol fractions <0.12 and <0.05 for the liquid and vapour phase, respectively.

  12. MHD pressure drop of imperfect insulation of liquid metal flow

    International Nuclear Information System (INIS)

    Horiike, H.; Nishiura, R.; Inoue, S.; Miyazaki, K.

    2000-01-01

    An experiment was performed to study magnetohydrodynamic (MHD) pressure gradient in the case of an imperfect electric insulation coating when using NaK loop. Test channels with uniform defects in their coating were made by painting inner surface with acrylic lacquer insulation. It was found that the exponent to B -- which is 1 for insulated walls, and 2 for conducting ones, was very sensitive to crack fractions lower than 25%. The pressure gradient was found to increase almost linearly with the fraction

  13. Temperature measurement in the liquid helium range at pressure

    International Nuclear Information System (INIS)

    Itskevich, E.S.; Krajdenov, V.F.

    1978-01-01

    The use of bronze and germanium resistance thermometers and the use of a (Au + 0.07 % Fe)-Cu thermocouple for temperature measurements from 1.5 to 4.2 K in the hydrostatic compression of up to 10 kbar are considered. To this aim, the thermometer resistance as a function of temperature and pressure is measured. It is revealed that pressure does not change the thermometric response of the bronze resistance thermometer but only shifts it to the region of lower temperatures. The identical investigations of the germanium resistance thermometer shows that strong temperature dependence and the shift of its thermometric response under the influence of pressure make the use of germanium resistance thermometers in high-pressure chambers very inconvenient. The results of the analysis of the (Au + 0.07 % Fe) - Cu thermocouple shows that with a 2 per cent accuracy the thermocouple Seebeck coefficient does not depend on pressure. It permits to use this thermocouple for temperature measurements at high pressures

  14. 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.

  15. Communication: High pressure specific heat spectroscopy reveals simple relaxation behavior of glass forming molecular liquid

    DEFF Research Database (Denmark)

    Roed, Lisa Anita; Niss, Kristine; Jakobsen, Bo

    2015-01-01

    The frequency dependent specific heat has been measured under pressure for the molecular glass forming liquid 5-polyphenyl-4-ether in the viscous regime close to the glass transition. The temperature and pressure dependences of the characteristic time scale associated with the specific heat...... is compared to the equivalent time scale from dielectric spectroscopy performed under identical conditions. It is shown that the ratio between the two time scales is independent of both temperature and pressure. This observation is non-trivial and demonstrates the existence of specially simple molecular...... liquids in which different physical relaxation processes are both as function of temperature and pressure/density governed by the same underlying “inner clock.” Furthermore, the results are discussed in terms of the recent conjecture that van der Waals liquids, like the measuredliquid, comply...

  16. The loss of essential oil components induced by the Purge Time in the Pressurized Liquid Extraction (PLE) procedure of Cupressus sempervirens.

    Science.gov (United States)

    Dawidowicz, Andrzej L; Czapczyńska, Natalia B; Wianowska, Dorota

    2012-05-30

    The influence of different Purge Times on the effectiveness of Pressurized Liquid Extraction (PLE) of volatile oil components from cypress plant matrix (Cupressus sempervirens) was investigated, applying solvents of diverse extraction efficiencies. The obtained results show the decrease of the mass yields of essential oil components as a result of increased Purge Time. The loss of extracted components depends on the extrahent type - the greatest mass yield loss occurred in the case of non-polar solvents, whereas the smallest was found in polar extracts. Comparisons of the PLE method with Sea Sand Disruption Method (SSDM), Matrix Solid-Phase Dispersion Method (MSPD) and Steam Distillation (SD) were performed to assess the method's accuracy. Independent of the solvent and Purge Time applied in the PLE process, the total mass yield was lower than the one obtained for simple, short and relatively cheap low-temperature matrix disruption procedures - MSPD and SSDM. Thus, in the case of volatile oils analysis, the application of these methods is advisable. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Laser ignition of liquid petroleum gas at elevated pressures

    Science.gov (United States)

    Loktionov, E.; Pasechnikov, N.; Telekh, V.

    2017-11-01

    Recent development of laser spark plugs for internal combustion engines have shown lack of data on laser ignition of fuel mixtures at multi-bar pressures needed for laser pulse energy and focusing optimisation. Methane and hydrogen based mixtures are comparatively well investigated, but propane and butane based ones (LPG), which are widely used in vehicles, are still almost unstudied. Optical breakdown thresholds in gases decrease with pressure increase up to ca. 100 bar, but breakdown is not a sufficient condition for combustion ignition. So minimum ignition energy (MIE) becomes more important for combustion core onset, and its dependency on mixture composition and pressure has several important features. For example, unlike breakdown threshold, is poorly dependent on laser pulse length, at least in pico- and to microsecond range. We have defined experimentally the dependencies of minimum picosecond laser pulse energies (MIE related value) needed for ignition of LPG based mixtures of 1.0 to 1.6 equivalence ratios and pressure of 1.0 to 3.5 bar. In addition to expected values decrease, low-energy flammability range broadening has been found at pressure increase. Laser ignition of LPG in Wankel rotary engine is reported for the first time.

  18. 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.

  19. Pressure-induced drastic structural change in liquid CdTe

    International Nuclear Information System (INIS)

    Kinoshita, T.; Hattori, T.; Narushima, T.; Tsuji, K.

    2005-01-01

    We investigate the structure of liquid CdTe at pressures up to 6 GPa by synchrotron x-ray diffraction. The structure factor, S(Q), and the pair distribution function, g(r), change drastically within a small pressure interval of about 1 GPa (between 1.8 and 3 GPa). The S(Q),g(r), and other structural parameters, such as the average coordination number, CN, and the ratios of peak positions in S(Q) or g(r), reveal that the change originates from the pressure-induced modification in the local structure from the zinc-blende-like form into the rocksaltlike one. The liquid CdTe shows a high-pressure behavior similar to that in the crystalline counterpart in terms of the sharpness of the structural change and the high-pressure sequence in the local structure

  20. Recent Experimental Efforts on High-Pressure Supercritical Injection for Liquid Rockets and Their Implications

    Directory of Open Access Journals (Sweden)

    Bruce Chehroudi

    2012-01-01

    Full Text Available Pressure and temperature of the liquid rocket thrust chambers into which propellants are injected have been in an ascending trajectory to gain higher specific impulse. It is quite possible then that the thermodynamic condition into which liquid propellants are injected reaches or surpasses the critical point of one or more of the injected fluids. For example, in cryogenic hydrogen/oxygen liquid rocket engines, such as Space Shuttle Main Engine (SSME or Vulcain (Ariane 5, the injected liquid oxygen finds itself in a supercritical condition. Very little detailed information was available on the behavior of liquid jets under such a harsh environment nearly two decades ago. The author had the opportunity to be intimately involved in the evolutionary understanding of injection processes at the Air Force Research Laboratory (AFRL, spanning sub- to supercritical conditions during this period. The information included here attempts to present a coherent summary of experimental achievements pertinent to liquid rockets, focusing only on the injection of nonreacting cryogenic liquids into a high-pressure environment surpassing the critical point of at least one of the propellants. Moreover, some implications of the results acquired under such an environment are offered in the context of the liquid rocket combustion instability problem.

  1. Pressure Dependence of Komatiite Liquid Viscosity and Implications for Magma Ocean Rheology

    Science.gov (United States)

    O'Dwyer Brown, L.; Lesher, C. E.; Terasaki, H. G.; Yamada, A.; Sakamaki, T.; Shibazaki, Y.; Ohtani, E.

    2009-12-01

    The viscosities of komatiite liquids at high pressures and temperatures were investigated using the in-situ falling sphere technique at BL04B1, SPring-8. Komatiites are naturally occurring magmas, rich in network modifying cations. Despite the refractory and fluid nature of komatiite, we successfully measured the viscosity of molten komatiites from Gorgona Island, Colombia (MgO = 17.8 wt.%; NBO/T = 1.5) between 11 and 13 GPa at 2000 C, and from Belingwe, Zimbabwe (MgO = 28.14 wt.%; NBO/T = 2.1) from 12 to 14 GPa at 2000 C. Under isothermal conditions, the viscosity of Gorgona Island komatiite melt increased with pressure, consistent with our previous measurements at lower pressures for this composition. We interpreted this positive pressure dependence as the result of reductions in interatomic space diminishing the free volume of the liquid when compressed. The viscosity of molten komatiite from Belingwe also increased up to 12 GPa, however between 12 and 14 GPa the viscosity is nearly constant. In previous studies of depolymerized silicate liquids, the pressure dependence of viscosity has been shown to reverse from positive to negative between 8 and 10 GPa with corresponding changes in activation volume [1] [2]. In contrast, the activation volume for Belingwe liquid decreases to near zero, but does not become negative above 11 GPa. Similarly, the activation volume for Gorgona Island komatiite remains positive throughout the pressure range investigated. Molecular dynamics simulations of simple MgO-SiO2 liquids with NBO/T > 2 also show a positive pressure dependence, reflecting the dominant control of free-volume reduction on the viscosity of depolymerized melts. However, the more rapid reduction in activation volume with pressure in komatiite liquids may be related to the presence of Al, Ti and other cations that interact and undergo coordination changes unavailable in simple silicate liquids. Along Hadean and post-Hadean mantle adiabats the net effect of

  2. Recovery of Steroidal Alkaloids from Potato Peels Using Pressurized Liquid Extraction

    Directory of Open Access Journals (Sweden)

    Mohammad B. Hossain

    2015-05-01

    Full Text Available A higher yield of glycoalkaloids was recovered from potato peels using pressurized liquid extraction (1.92 mg/g dried potato peels compared to conventional solid–liquid extraction (0.981 mg/g dried potato peels. Response surface methodology deduced the optimal temperature and extracting solvent (methanol for the pressurized liquid extraction (PLE of glycoalkaloids as 80 °C in 89% methanol. Using these two optimum PLE conditions, levels of individual steroidal alkaloids obtained were of 597, 873, 374 and 75 µg/g dried potato peel for α-solanine, α-chaconine, solanidine and demissidine respectively. Corresponding values for solid liquid extraction were 59%, 46%, 40% and 52% lower for α-solanine, α-chaconine, solanidine and demissidine respectively.

  3. Measurement and correlation of vapour pressures of pyridine and thiophene with [EMIM][SCN] ionic liquid

    International Nuclear Information System (INIS)

    Khelassi-Sefaoui, Asma; Mutelet, Fabrice; Mokbel, Ilham; Jose, Jacques; Negadi, Latifa

    2014-01-01

    Highlights: • VLE of (pyridine + [EMIM][SCN]), or (thiophene + [EMIM][SCN]) binary mixtures were measured. • The investigated temperatures are 273 K to 363 K. • The PC-SAFT equation of state has been used to correlate the vapour pressures of the binary systems. - Abstract: In this work (vapour + liquid) equilibrium (VLE) measurements were performed on binary systems of the ionic liquid 1-ethyl-3-methylimidazolium thiocynate [EMIM][SCN] with thiophene or pyridine at pressures close to the atmospheric pressure using a static device at temperatures between 273 K and 363 K. Experimental data were correlated by the PC-SAFT EoS. The binary interaction parameters k ij were optimised on experimental VLE data. The results obtained for the two binary mixtures studied in this paper indicate that the PC-SAFT EoS can be used to represent systems containing ionic liquids

  4. 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…

  5. Cuttings-liquid frictional pressure loss model for horizontal narrow annular flow with rotating drillpipe

    International Nuclear Information System (INIS)

    Ofei, T N; Irawan, S; Pao, W

    2015-01-01

    During oil and gas drilling operations, frictional pressure loss is experienced as the drilling fluid transports the drilled cuttings from the bottom-hole, through the annulus, to the surface. Estimation of these pressure losses is critical when designing the drilling hydraulic program. Two-phase frictional pressure loss in the annulus is very difficult to predict, and even more complex when there is drillpipe rotation. Accurate prediction will ensure that the correct equivalent circulating density (ECD) is applied in the wellbore to prevent formation fracture, especially in formations with narrow window between the pore pressure and fracture gradient. Few researchers have attempted to propose cuttings-liquid frictional pressure loss models, nevertheless, these models fail when they are applied to narrow wellbores such as in casing- while-drilling and slimhole applications. This study proposes improved cuttings-liquid frictional pressure loss models for narrow horizontal annuli with drillpipe rotation using Dimensional Analysis. Both Newtonian and non-Newtonian fluids were considered. The proposed model constants were fitted by generated data from a full-scale simulation study using ANSYS-CFX. The models showed improvement over existing cuttings-liquid pressure loss correlations in literature. (paper)

  6. Hydrogen and carbon vapour pressure isotope effects in liquid fluoroform studied by density functional theory

    Energy Technology Data Exchange (ETDEWEB)

    Oi, Takao; Mitome, Ryota; Yanase, Satoshi [Sophia Univ., Tokyo (Japan). Faculty of Science and Technology

    2017-06-01

    H/D and {sup 12}C/{sup 13}C vapour pressure isotope effects (VPIEs) in liquid fluoroform (CHF{sub 3}) were studied at the MPW1PW91/6-31 ++ G(d) level of theory. The CHF{sub 3} monomer and CHF{sub 3} molecules surrounded by other CHF{sub 3} molecules in every direction in CHF{sub 3} clusters were used as model molecules of vapour and liquid CHF{sub 3}. Although experimental results in which the vapour pressure of liquid {sup 12}CHF{sub 3} is higher than that of liquid {sup 12}CDF{sub 3} and the vapour pressure of liquid {sup 13}CHF{sub 3} is higher than that of liquid {sup 12}CHF{sub 3} between 125 and 212 K were qualitatively reproduced, the present calculations overestimated the H/D VPIE and underestimated the {sup 12}C/{sup 13}C VPIE. Temperature-dependent intermolecular interactions between hydrogen and fluorine atoms of neighbouring molecules were required to explain the temperature dependences of both H/D and {sup 12}C/{sup 13}C VPIEs.

  7. Determination of liquid viscosity at high pressure by DLS

    International Nuclear Information System (INIS)

    Fukui, K; Asakuma, Y; Maeda, K

    2010-01-01

    The movement of particles with a size smaller than few microns is governed by random Brownian motion. This motion causes the fluid to flow around the particles. The force acting upon Brownian particles as well as their velocities are measured by using the dynamic light scattering (DLS) technique. It provides the relationship between fluid shear stress and shear rate over the Brownian particle and determines the viscosity properties of the fluid. In this study, we propose a new rheometer which is widely applicable to fluid viscosity measurements at both normal and high pressure levels for Newtonian and non- Newtonian fluids.

  8. Hydrodynamics in a cocurrent gas-liquid trickle bed at elevated pressures

    OpenAIRE

    Wammes, W.J.A.; Middelkamp, J.; Huisman, W.J.; Huisman, W.J.; de Baas, C.M.; de Baas, C.M.; Westerterp, K.R.

    1991-01-01

    Data on design and operation of trickle beds at elevated pressures are scarce. In this study the influence of the gas density on the liquid holdup, the pressure drop, and the transition between trickle and pulse flow has been investigated in a tricklebed reactor operating up to 7.5 MPa and with nitrogen or helium as the gas phase. Gas-liquid interfacial areas have been determined up to 5.0 MPa by means of CO2 absorption from CO2/N2 gas mixtures into amine solutions. A comparison of the result...

  9. Stabilization of axisymmetric liquid bridges through vibration-induced pressure fields.

    Science.gov (United States)

    Haynes, M; Vega, E J; Herrada, M A; Benilov, E S; Montanero, J M

    2018-03-01

    Previous theoretical studies have indicated that liquid bridges close to the Plateau-Rayleigh instability limit can be stabilized when the upper supporting disk vibrates at a very high frequency and with a very small amplitude. The major effect of the vibration-induced pressure field is to straighten the liquid bridge free surface to compensate for the deformation caused by gravity. As a consequence, the apparent Bond number decreases and the maximum liquid bridge length increases. In this paper, we show experimentally that this procedure can be used to stabilize millimeter liquid bridges in air under normal gravity conditions. The breakup of vibrated liquid bridges is examined experimentally and compared with that produced in absence of vibration. In addition, we analyze numerically the dynamics of axisymmetric liquid bridges far from the Plateau-Rayleigh instability limit by solving the Navier-Stokes equations. We calculate the eigenfrequencies characterizing the linear oscillation modes of vibrated liquid bridges, and determine their stability limits. The breakup process of a vibrated liquid bridge at that stability limit is simulated too. We find qualitative agreement between the numerical predictions for both the stability limits and the breakup process and their experimental counterparts. Finally, we show the applicability of our technique to control the amount of liquid transferred between two solid surfaces. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Molecular Dynamics Simulations of Liquid Phosphorus at High Temperature and Pressure

    International Nuclear Information System (INIS)

    Wu Yanning; Zhao Gang; Liu Changsong; Zhu Zhengang

    2008-01-01

    By performing ab initio molecular dynamics simulations, we have investigated the microstructure, dynamical and electronic properties of liquid phosphorus (P) under high temperature and pressure. In our simulations, the calculated coordination number (CN) changes discontinuously with density, and seems to increase rapidly after liquid P is compressed to 2.5 g/cm 3 . Under compression, liquid P shows the first-order liquid-liquid phase transition from the molecular liquid composed of the tetrahedral P 4 molecules to complex polymeric form with three-dimensional network structure, accompanied by the nonmetal to metal transition of the electronic structure. The order parameters Q 6 and Q 4 are sensitive to the microstructural change of liquid P. By calculating diffusion coefficients, we show the dynamical anomaly of liquid P by compression. At lower temperatures, a maximum exists at the diffusion coefficients as a function of density; at higher temperatures, the anomalous behavior is weakened. The excess entropy shows the same phenomena as the diffusion coefficients. By analysis of the angle distribution functions and angular limited triplet correlation functions, we can clearly find that the Peierls distortion in polymeric form of liquid P is reduced by further compression

  11. 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

  12. Density and Phase State of a Confined Nonpolar Fluid

    Science.gov (United States)

    Kienle, Daniel F.; Kuhl, Tonya L.

    2016-07-01

    Measurements of the mean refractive index of a spherelike nonpolar fluid, octamethytetracylclosiloxane (OMCTS), confined between mica sheets, demonstrate direct and conclusive experimental evidence of the absence of a first-order liquid-to-solid phase transition in the fluid when confined, which has been suggested to occur from previous experimental and simulation results. The results also show that the density remains constant throughout confinement, and that the fluid is incompressible. This, along with the observation of very large increases (many orders of magnitude) in viscosity during confinement from the literature, demonstrate that the molecular motion is limited by the confining wall and not the molecular packing. In addition, the recently developed refractive index profile correction method, which enables the structural perturbation inherent at a solid-liquid interface and that of a liquid in confinement to be determined independently, was used to show that there was no measurable excess or depleted mass of OMCTS near the mica surface in bulk films or confined films of only two molecular layers.

  13. High-pressure study of the non-Fermi liquid material U2Pt2In

    International Nuclear Information System (INIS)

    Estrela, P.; Visser, A. de; Boer, F.R. de; Pereira, L.C.J.

    2001-01-01

    The effect of hydrostatic pressure (p≤1.8 GPa) on the non-Fermi liquid state of U 2 Pt 2 In is investigated by electrical resistivity measurements in the temperature interval 0.3-300 K. The experiments were carried out on single-crystals with the current along (I parallel c) and perpendicular (I parallel a) to the tetragonal axis. The pressure effect is strongly current-direction dependent. For I parallel a we observe a rapid recovery of the Fermi-liquid T 2 -term with pressure. A comparison of the data with the magnetotransport theory of Rosch provides evidence for the location of U 2 Pt 2 In at an antiferromagnetic quantum critical point. For I parallel c the resistivity increases under pressure, indicating the enhancement of an additional scattering mechanism. (orig.)

  14. Ultrasound and orientational relaxation of nematic liquid crystals at high pressure

    International Nuclear Information System (INIS)

    Khabibullaev, P.K.; Oribjonov, Kh.J.; Lagunov, A.S.

    2004-01-01

    The acoustic properties of the nematic liquid crystal N-96 and its benzene solution in anisotropic phase are investigated in rotational magnetic field. The effects of concentration, temperature, pressure, and frequency of magnetic field rotation on ultrasonic absorption anisotropy are studied. Critical frequency values are experimentally determined. The relationship between the diamagnetic susceptibility anisotropy rotational viscosities was calculated, and its dependences on the pressure and temperature are also discussed. (author)

  15. An ultrasound-based liquid pressure measurement method in small diameter pipelines considering the installation and temperature.

    Science.gov (United States)

    Li, Xue; Song, Zhengxiang

    2015-04-09

    Liquid pressure is a key parameter for detecting and judging faults in hydraulic mechanisms, but traditional measurement methods have many deficiencies. An effective non-intrusive method using an ultrasound-based technique to measure liquid pressure in small diameter (less than 15 mm) pipelines is presented in this paper. The proposed method is based on the principle that the transmission speed of an ultrasonic wave in a Kneser liquid correlates with liquid pressure. Liquid pressure was calculated using the variation of ultrasonic propagation time in a liquid under different pressures: 0 Pa and X Pa. In this research the time difference was obtained by an electrical processing approach and was accurately measured to the nanosecond level through a high-resolution time measurement module. Because installation differences and liquid temperatures could influence the measurement accuracy, a special type of circuit called automatic gain control (AGC) circuit and a new back propagation network (BPN) model accounting for liquid temperature were employed to improve the measurement results. The corresponding pressure values were finally obtained by utilizing the relationship between time difference, transient temperature and liquid pressure. An experimental pressure measurement platform was built and the experimental results confirm that the proposed method has good measurement accuracy.

  16. 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.

  17. 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.

  18. Non-linearity parameter of binary liquid mixtures at elevated pressures

    Indian Academy of Sciences (India)

    parameter B/A of four binary liquid mixtures using Tong and Dong equation at high pressures and .... in general as regular or ideal as no recognized association takes place between the unlike molecules. In this case ... Using the definition and.

  19. Decomposition of pilocarpine eye drops assessed by a highly efficient high pressure liquid chromatographic method

    NARCIS (Netherlands)

    Kuks, P. F.; Weekers, L. E.; Goldhoorn, P. B.

    1990-01-01

    A rapid high-resolution high pressure liquid chromatographic method was developed for assaying pilocarpine. Pilocarpine in ophthalmic solutions decomposes fairly rapidly to give isopilocarpine, pilocarpic acid and isopilocarpic acid. The quality of an ophthalmic solution can be assessed by assaying

  20. Process for carrying out a chemical reaction with ionic liquid and carbon dioxide under pressure

    NARCIS (Netherlands)

    Kroon, M.C.; Shariati, A.; Florusse, L.J.; Peters, C.J.; Van Spronsen, J.; Witkamp, G.J.; Sheldon, R.A.; Gutkowski, K.I.

    2006-01-01

    The invention is directed to a process for carrying out a chemical reaction in an ionic liquid as solvent and CO2 as cosolvent, in which process reactants are reacted in a homogeneous phase at selected pressure and temperature to generate a reaction product at least containing an end-product of the

  1. Extraction of polycyclic aromatic hydrocarbons from smoked fish using pressurized liquid extraction with integrated fat removal

    DEFF Research Database (Denmark)

    Lund, Mette; Duedahl-Olesen, Lene; Christensen, Jan H.

    2009-01-01

    Quantification of polycyclic aromatic hydrocarbons (PAHs) in smoked fish products often requires multiple clean-up steps to remove fat and other compounds that may interfere with the chemical analysis. We present a novel pressurized liquid extraction (PLE) method that integrates exhaustive...

  2. Transient effects caused by pulsed gas and liquid injections into low pressure plasmas

    International Nuclear Information System (INIS)

    Ogawa, D; Goeckner, M; Overzet, L; Chung, C W

    2010-01-01

    The fast injection of liquid droplets into a glow discharge causes significant time variations in the pressure, the chemical composition of the gas and the phases present (liquid and/or solid along with gas). While the variations can be large and important, very few studies, especially kinetic studies, have been published. In this paper we examine the changes brought about in argon plasma by injecting Ar (gas), N 2 (gas) hexane (gas) and hexane (liquid droplets). The changes in the RF capacitively coupled power (forward and reflected), electron and ion density (n e , n i ), electron temperature (T e ) and optical emissions were monitored during the injections. It was found that the Ar injection (pressure change only) caused expected variations. The electron temperature reduced, the plasma density increased and the optical emission intensity remained nearly constant. The N 2 and hexane gas injections (chemical composition and pressure changes) also followed expected trends. The plasma densities increased and electron temperature decreased while the optical emissions changed from argon to the injected gas. These all serve to highlight the fact that the injection of evaporating hexane droplets in the plasma caused very little change. This is because the number of injected droplets is too small to noticeably affect the plasma, even though the shift in the chemical composition of the gas caused by evaporation from those same droplets can be very significant. The net conclusion is that using liquid droplets to inject precursors for low pressure plasmas is both feasible and controllable.

  3. Mobilities of slow electrons in low- and high-pressure gases and liquids

    International Nuclear Information System (INIS)

    Christophorou, L.G.

    1975-01-01

    Mobilities of slow (thermal and epithermal) electrons in low- (less than or approximately 500 Torr) and high- (approximately 500 to approximately 34,111 Torr) pressure gases are discussed and are related to the molecular structure and to the mobilities of thermal electrons in liquid media

  4. Constant pressure mode extended simple gradient liquid chromatography system for micro and nanocolumns

    Czech Academy of Sciences Publication Activity Database

    Šesták, Jozef; Kahle, Vladislav

    2014-01-01

    Roč. 1350, Jul (2014), s. 68-71 ISSN 0021-9673 R&D Projects: GA MV VG20102015023 Institutional support: RVO:68081715 Keywords : constant pressure HPLC * gradient elution * simple liquid chromatograph Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.169, year: 2014 http://hdl.handle.net/11104/0233990

  5. High-pressure liquid chromatographic assay of Bay n 7133 in human serum.

    OpenAIRE

    Fasching, C E; Hughes, C E; Hector, R F; Peterson, L R

    1984-01-01

    A high-pressure liquid chromatographic method that includes a Sep-Pak (Waters Associates, Inc., Milford , Mass.) preparation of human serum was employed for the quantitative assay of Bay n 7133. Drug levels of 0.1 to 20 micrograms/ml could be detected. No interference from amphotericin B was found in the chromatographic analysis of Bay n 7133.

  6. Deformation and degradation of polymers in ultra-high-pressure liquid chromatography

    NARCIS (Netherlands)

    Uliyanchenko, E.; van der Wal, S.; Schoenmakers, P.J.

    2011-01-01

    Ultra-high-pressure liquid chromatography (UHPLC) using columns packed with sub-2 μm particles has great potential for separations of many types of complex samples, including polymers. However, the application of UHPLC for the analysis of polymers meets some fundamental obstacles. Small particles

  7. Characterization of typical chemical background interferences in atmospheric pressure ionization liquid chromatography-mass spectrometry

    NARCIS (Netherlands)

    Guo, Xinghua; Bruins, Andries P.; Covey, Thomas R.

    2006-01-01

    The structures and origins of typical chemical background noise ions in positive atmospheric pressure ionization liquid chromatography/mass spectrometry (API LC/MS) are investigated and summarized in this study. This was done by classifying chemical background ions using precursor and product ion

  8. Characteristics of atmospheric pressure air discharges with a liquid cathode and a metal anode

    Czech Academy of Sciences Publication Activity Database

    Bruggeman, P.; Ribežl, E.; Degroote, J.; Malesevic, A.; Rego, R.; Vierendeels, J.; Leys, C.; Mašláni, Alan

    2008-01-01

    Roč. 17, č. 2 (2008), s. 1-11 ISSN 0963-0252 Institutional research plan: CEZ:AV0Z20430508 Keywords : atmospheric pressure air discharge * liquid cathode * voltage drop * optical emission spectroscopy Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.685, year: 2008

  9. Boiling-up of a liquid in a large volume at fast pressure drop

    International Nuclear Information System (INIS)

    Isaev, O.A.; Pavlov, P.A.

    1980-01-01

    Experiment results on sharp pressure drop in overheated water and carbon dioxide are presented. Pressure fields are investigated upon seal failure of the tube for various initial temperatures varying in the 0.57-0.97 interval on critical temperature. The depth of the liOuid inlet into the metastable region can be compared with maximum permissible superheating of a pure liquid. The applicability of fluctuation embrion formation for pressure calculation in the initial phase of explosive boiling-up at seal failure of the system is considered. The nature of boiling centers origin is discussed

  10. PIEZOELECTRIC WAVEGUIDE SENSOR FOR MEASURING PULSE PRESSURE IN CLOSED LIQUID VOLUMES AT HIGH VOLTAGE ELECTRIC DISCHARGE

    Directory of Open Access Journals (Sweden)

    V. G. Zhekul

    2017-10-01

    Full Text Available Purpose. Investigations of the characteristics of pressure waves presuppose the registration of the total profile of the pressure wave at a given point in space. For these purposes, various types of «pressure to the electrical signal» transmitters (sensors are used. Most of the common sensors are unsuitable for measuring the pulse pressure in a closed water volume at high hydrostatic pressures, in particular to study the effect of a powerful high-voltage pulse discharge on increasing the inflow of minerals and drinking water in wells. The purpose of the work was to develop antijamming piezoelectric waveguide sensor for measuring pulse pressure at a close distance from a high-voltage discharge channel in a closed volume of a liquid. Methodology. We have applied the calibration method as used as a secondary standard, the theory of electrical circuits. Results. We have selected the design and the circuit solution of the waveguide pressure sensor. We have developed a waveguide pulse-pressure sensor DTX-1 with a measuring loop. This sensor makes it possible to study the spectral characteristics of pressure waves of high-voltage pulse discharge in closed volumes of liquid at a hydrostatic pressure of up to 20 MPa and a temperature of up to 80 °C. The sensor can be used to study pressure waves with a maximum amplitude value of up to 150 MPa and duration of up to 80 µs. According to the results of the calibration, the sensitivity of the developed sensor DTX-1 with a measuring loop is 0.0346 V/MPa. Originality. We have further developed the theory of designing the waveguide piezoelectric pulse pressure sensors for measuring the pulse pressure at a close distance from a high-voltage discharge channel in a closed fluid volume by controlling the attenuation of the amplitude of the pressure signal. Practical value. We have developed, created, calibrated, used in scientific research waveguide pressure pulse sensors DTX-1. We propose sensors DTX-1 for sale

  11. Transient response of a liquid injector to a steep-fronted transverse pressure wave

    Science.gov (United States)

    Lim, D.; Heister, S.; Stechmann, D.; Kan, B.

    2017-12-01

    Motivated by the dynamic injection environment posed by unsteady pressure gain combustion processes, an experimental apparatus was developed to visualize the dynamic response of a transparent liquid injector subjected to a single steep-fronted transverse pressure wave. Experiments were conducted at atmospheric pressure with a variety of acrylic injector passage designs using water as the working fluid. High-speed visual observations were made of the injector exit near field, and the extent of backflow and the time to refill the orifice passage were characterized over a range of injection pressures. A companion transient one-dimensional model was developed for interpretation of the results and to elucidate the trends with regard to the strength of the transverse pressure wave. Results from the model were compared with the experimental observations.

  12. Liquid electrode

    Science.gov (United States)

    Ekechukwu, A.A.

    1994-07-05

    A dropping electrolyte electrode is described for use in electrochemical analysis of non-polar sample solutions, such as benzene or cyclohexane. The liquid electrode, preferably an aqueous salt solution immiscible in the sample solution, is introduced into the solution in dropwise fashion from a capillary. The electrolyte is introduced at a known rate, thus, the droplets each have the same volume and surface area. The electrode is used in making standard electrochemical measurements in order to determine properties of non-polar sample solutions. 2 figures.

  13. Highly pressurized partially miscible liquid-liquid flow in a micro-T-junction. I. Experimental observations

    Science.gov (United States)

    Qin, Ning; Wen, John Z.; Ren, Carolyn L.

    2017-04-01

    This is the first part of a two-part study on a partially miscible liquid-liquid flow (liquid carbon dioxide and deionized water) which is highly pressurized and confined in a microfluidic T-junction. Our main focuses are to understand the flow regimes as a result of varying flow conditions and investigate the characteristics of drop flow distinct from coflow, with a capillary number, C ac , that is calculated based on the continuous liquid, ranging from 10-3 to 10-2 (10-4 for coflow). Here in part I, we present our experimental observation of drop formation cycle by tracking drop length, spacing, frequency, and after-generation speed using high-speed video and image analysis. The drop flow is chronologically composed of a stagnating and filling stage, an elongating and squeezing stage, and a truncating stage. The common "necking" time during the elongating and squeezing stage (with C ac˜10-3 ) for the truncation of the dispersed liquid stream is extended, and the truncation point is subsequently shifted downstream from the T-junction corner. This temporal postponement effect modifies the scaling function reported in the literature for droplet formation with two immiscible fluids. Our experimental measurements also demonstrate the drop speed immediately following their generations can be approximated by the mean velocity from averaging the total flow rate over the channel cross section. Further justifications of the quantitative analysis by considering the mass transfer at the interface of the two partially miscible fluids are provided in part II.

  14. Evidence for a first-order liquid-liquid transition in high-pressure hydrogen from ab initio simulations.

    Science.gov (United States)

    Morales, Miguel A; Pierleoni, Carlo; Schwegler, Eric; Ceperley, D M

    2010-07-20

    Using quantum simulation techniques based on either density functional theory or quantum Monte Carlo, we find clear evidence of a first-order transition in liquid hydrogen, between a low conductivity molecular state and a high conductivity atomic state. Using the temperature dependence of the discontinuity in the electronic conductivity, we estimate the critical point of the transition at temperatures near 2,000 K and pressures near 120 GPa. Furthermore, we have determined the melting curve of molecular hydrogen up to pressures of 200 GPa, finding a reentrant melting line. The melting line crosses the metalization line at 700 K and 220 GPa using density functional energetics and at 550 K and 290 GPa using quantum Monte Carlo energetics.

  15. Local structures of ionic liquids in the presence of gold under high pressures

    Directory of Open Access Journals (Sweden)

    Hai-Chou Chang

    2013-03-01

    Full Text Available The interactions between ionic liquid ([EMI][TFS] and gold surfaces have been investigated via the application of pressures up to ca. 2 GPa. Comparing the spectral features of [EMI][TFS]/gold with those of pure [EMI][TFS], no appreciable changes of C-H bands in the presence of gold powders were observed under ambient pressure. Nevertheless, the imidazolium C-H bands display red shifts in frequency as the [EMI][TFS] / Au mixture was compressed to the pressure above 1.4 GPa and a new alkyl C-H band at ca. 3016 cm−1 was also revealed. These spectral changes, being related to the addition of gold powders and pressure elevation, should be attributed to the local structural changes of C-H groups caused by pressure-enhanced interfacial interactions between [EMI][TFS] and Au. Gold powders tend to induce the changes in hydrogen bonding structures of imidazolium C2-H group under high pressures. The pressure-dependent spectral features in the asymmetric SO3 stretching region display band-narrowing and minor local structural changes induced by the presence of gold particles under high pressures. These observations suggest that Au powders perturb structural equilibrium of C-H groups of cations under high pressures.

  16. Analytical Stationary Acoustic Wave in a Liquid over Which a Moving Pressure Runs

    Directory of Open Access Journals (Sweden)

    André Langlet

    2010-01-01

    Full Text Available This paper presents an analytical study of the stationary response of a liquid loaded on its free surface by an ideal pressure step moving in a constant direction at a constant velocity. The acoustic pressure in the liquid is found, in four different examples, by means of the Fourier Transform. Two loading regimes are considered; subsonic and supersonic. Two configurations of liquid domains are also studied, the first one is a half infinite space while the second one is bounded by a rigid bottom at a finite depth. For the two supersonic cases, a simple reasoning based on the existence of a front of discontinuity in the liquid and on the property of reflection of waves confirms the result of the mathematical investigations. The results obtained for the steady state case are of intererest, even when the loading is not exactly stationary, such as the presure produced by an explosion occurring in the vicinity of the surface of a liquid. Two numerically resolved examples are presented, which confirm this assumption.

  17. The break-up dynamics of liquid threads revealed by laser radiation pressure and optocapillarity

    Science.gov (United States)

    Petit, Julien; Robert de Saint Vincent, Matthieu; Rivière, David; Kellay, Hamid; Delville, Jean-Pierre

    2014-09-01

    We show how optocapillary stresses and optical radiation pressure effects in two-phase liquids open the way for investigating the difficult problem of liquid thread breakup at small scales when surfactants are present at the interface or when the roughness of the interface becomes significant. Using thermocapillary stresses driven by light to pinch a surfactant-laden microjet, we observe deviations from the expected visco-capillary law governed by a balance between viscosity and interfacial tension. We suggest that these deviations are due to time varying interfacial tension resulting from the surfactant depletion at the neck pinching location, and we experimentally confirm this mechanism. The second case is representative of the physics of nanojets. Considering a near critical liquid-liquid interface, where the roughness of the interfaces may be tuned, we use the radiation pressure of a laser wave to produce stable fluctuating liquid columns and study their breakup. We show how pinching crosses over from the visco-capillary to a fluctuation dominated regime and describe this new regime. These experiments exemplify how optofluidics can reveal new physics of fluids.

  18. Pressure Dependence of the Liquid-Liquid Phase Transition of Nanopore Water Doped Slightly with Hydroxylamine, and a Phase Behavior Predicted for Pure Water

    Science.gov (United States)

    Nagoe, Atsushi; Iwaki, Shinji; Oguni, Masaharu; Tôzaki, Ken-ichi

    2014-09-01

    Phase transition behaviors of confined pure water and confined water doped with a small amount of hydroxylamine (HA) with a mole fraction of xHA = 0.03 were examined by high-pressure differential thermal analyses at 0.1, 50, 100, and 150 MPa; the average diameters of silica pores used were 2.0 and 2.5 nm. A liquid-liquid phase transition (LLPT) of the confined HA-doped water was clearly observed and its pressurization effect could be evaluated, unlike in the experiments on undoped water. It was found that pressurization causes the transition temperature (Ttrs) to linearly decrease, indicating that the low-temperature phase has a lower density than the high-temperature one. Transition enthalpy (ΔtrsH) decreased steeply with increasing pressure. Considering the linear decrease in Ttrs with increasing pressure, the steep decrease in ΔtrsH indicates that the LLPT effect of the HA-doped water attenuates with pressure. We present a new scenario of the phase behavior concerning the LLPT of pure water based on the analogy from the behavior of slightly HA-doped water, where a liquid-liquid critical point (LLCP) and a coexistence line are located in a negative-pressure regime but not in a positive-pressure one. It is reasonably understood that doping a small amount of HA into water results in negative chemical pressurization and causes the LLPT to occur even at ambient pressure.

  19. 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

  20. Thermal conductivity of Glycerol's liquid, glass, and crystal states, glass-liquid-glass transition, and crystallization at high pressures.

    Science.gov (United States)

    Andersson, Ove; Johari, G P

    2016-02-14

    To investigate the effects of local density fluctuations on phonon propagation in a hydrogen bonded structure, we studied the thermal conductivity κ of the crystal, liquid, and glassy states of pure glycerol as a function of the temperature, T, and the pressure, p. We find that the following: (i) κcrystal is 3.6-times the κliquid value at 140 K at 0.1 MPa and 2.2-times at 290 K, and it varies with T according to 138 × T(-0.95); (ii) the ratio κliquid (p)/κliquid (0.1 MPa) is 1.45 GPa(-1) at 280 K, which, unexpectedly, is about the same as κcrystal (p)/κcrystal (0.1 MPa) of 1.42 GPa(-1) at 298 K; (iii) κglass is relatively insensitive to T but sensitive to the applied p (1.38 GPa(-1) at 150 K); (iv) κglass-T plots show an enhanced, pressure-dependent peak-like feature, which is due to the glass to liquid transition on heating; (v) continuous heating cold-crystallizes ultraviscous glycerol under pressure, at a higher T when p is high; and (vi) glycerol formed by cooling at a high p and then measured at a low p has a significantly higher κ than the glass formed by cooling at a low p. On heating at a fixed low p, its κ decreases before its glass-liquid transition range at that p is reached. We attribute this effect to thermally assisted loss of the configurational and vibrational instabilities of a glass formed at high p and recovered at low p, which is different from the usual glass-aging effect. While the heat capacity, entropy, and volume of glycerol crystal are less than those for its glass and liquid, κcrystal of glycerol, like its elastic modulus and refractive index, is higher. We discuss these findings in terms of the role of fluctuations in local density and structure, and the relations between κ and the thermodynamic quantities.

  1. Liquid densities and excess molar volumes for (ionic liquids + methanol + water) ternary system at atmospheric pressure and at various temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Deenadayalu, Nirmala [Department of Chemistry, Durban University of Technology, Steve Biko Campus, P.O. Box 1334, Durban, KwaZulu-Natal 4001 (South Africa)], E-mail: NirmalaD@dut.ac.za; Kumar, Satish; Bhujrajh, Pravena [Department of Chemistry, Durban University of Technology, Steve Biko Campus, P.O. Box 1334, Durban, KwaZulu-Natal 4001 (South Africa)

    2007-09-15

    Excess molar volumes, V{sub m}{sup E} have been evaluated from density measurements over the entire composition range for ternary liquid system of ionic liquid (1-ethyl-3-methyl-imidazolium diethylenglycol monomethylether sulphate {l_brace}[EMIM][CH{sub 3}(OCH{sub 2}CH{sub 2}){sub 2}OSO{sub 3}]) (1) + methanol (2) + water (3){r_brace} at T = (298.15, 303.15, and 313.15) K. A vibrating tube densimeter was used for these measurements at atmospheric pressure. The V{sub m}{sup E} values were found to be negative at T = (298.15 and 303.15) K. For {l_brace}[EMIM][CH{sub 3}(OCH{sub 2}CH{sub 2}){sub 2}OSO{sub 3}] (1) + methanol (2) + water (3){r_brace} at T = 313.15 K the V{sub m}{sup E} values become positive at higher mole fraction of ionic liquid and at a corresponding decrease in mole fraction of water. All the experimental data were fitted with the Redlich-Kister equation. The results have also been analysed in term of graph theoretical approach.

  2. Real-Time, Non-Intrusive Detection of Liquid Nitrogen in Liquid Oxygen at High Pressure and High Flow

    Science.gov (United States)

    Singh, Jagdish P.; Yueh, Fang-Yu; Kalluru, Rajamohan R.; Harrison, Louie

    2012-01-01

    An integrated fiber-optic Raman sensor has been designed for real-time, nonintrusive detection of liquid nitrogen in liquid oxygen (LOX) at high pressures and high flow rates in order to monitor the quality of LOX used during rocket engine ground testing. The integrated sensor employs a high-power (3-W) Melles Griot diode-pumped, solid-state (DPSS), frequency-doubled Nd:YAG 532- nm laser; a modified Raman probe that has built-in Raman signal filter optics; two high-resolution spectrometers; and photomultiplier tubes (PMTs) with selected bandpass filters to collect both N2 and O2 Raman signals. The PMT detection units are interfaced with National Instruments Lab- VIEW for fast data acquisition. Studies of sensor performance with different detection systems (i.e., spectrometer and PMT) were carried out. The concentration ratio of N2 and O2 can be inferred by comparing the intensities of the N2 and O2 Raman signals. The final system was fabricated to measure N2 and O2 gas mixtures as well as mixtures of liquid N2 and LOX

  3. Hyphenation of ultra high performance supercritical fluid chromatography with atmospheric pressure chemical ionisation high resolution mass spectrometry: Part 1. Study of the coupling parameters for the analysis of natural non-polar compounds.

    Science.gov (United States)

    Duval, Johanna; Colas, Cyril; Pecher, Virginie; Poujol, Marion; Tranchant, Jean-François; Lesellier, Eric

    2017-08-04

    An analytical method based on Ultra-High-Performance Supercritical Fluid Chromatography (UHPSFC) coupled with Atmospheric Pressure Chemical Ionization - High-resolution mass spectrometry (APCI-Q-TOF-HRMS) was developed for compounds screening from oily samples. The hyphenation was made using a commercial UHPLC device coupled to a CO 2 pump in order to perform the chromatographic analysis. An adaptation of the injection system for compressible fluids was accomplished for this coupling: this modification of the injection sequence was achieved to prevent unusual variations of the injected volume related to the use of a compressible fluid. UHPSFC-HRMS hyphenation was optimized to enhance the response of the varied compounds from a seed extract (anthraquinones, free fatty acids, diacylglycerols, hydroxylated triacylglycerols and triacylglycerols). No split was used prior to the APCI ionization source, allowing introducing all the compounds in the spectrometer, ensuring a better sensitivity for minor compounds. The effects of a mechanical make-up (T-piece) added before this ionization source was discussed in terms of standard deviation of response, response intensity and fragmentation percentage. The location of the T-piece with regards to the backpressure regulator (BPR), the flow rate and the nature of the make-up solvent were studied. Results show that the effects of the studied parameters depend on the nature of the compounds, whereas the make-up addition favours the robustness of the mass response (quantitative aspect). Copyright © 2017 Elsevier B.V. All rights reserved.

  4. An experimental device for accurate ultrasounds measurements in liquid foods at high pressure

    International Nuclear Information System (INIS)

    Hidalgo-Baltasar, E; Taravillo, M; Baonza, V G; Sanz, P D; Guignon, B

    2012-01-01

    The use of high hydrostatic pressure to ensure safe and high-quality product has markedly increased in the food industry during the last decade. Ultrasonic sensors can be employed to control such processes in an equivalent way as they are currently used in processes carried out at room pressure. However, their installation, calibration and use are particularly challenging in the context of a high pressure environment. Besides, data about acoustic properties of food under pressure and even for water are quite scarce in the pressure range of interest for food treatment (namely, above 200 MPa). The objective of this work was to establish a methodology to determine the speed of sound in foods under pressure. An ultrasonic sensor using the multiple reflections method was adapted to a lab-scale HHP equipment to determine the speed of sound in water between 253.15 and 348.15 K, and at pressures up to 700 MPa. The experimental speed-of-sound data were compared to the data calculated from the equation of state of water (IAPWS-95 formulation). From this analysis, the way to calibrate cell path was validated. After this calibration procedure, the speed of sound could be determined in liquid foods by using this sensor with a relative uncertainty between (0.22 and 0.32) % at a confidence level of 95 % over the whole pressure domain.

  5. Experimental investigation of MHD pressure losses in a mock-up of a liquid metal blanket

    Science.gov (United States)

    Mistrangelo, C.; Bühler, L.; Brinkmann, H.-J.

    2018-03-01

    Experiments have been performed to investigate the influence of a magnetic field on liquid metal flows in a scaled mock-up of a helium cooled lead lithium (HCLL) blanket. During the experiments pressure differences between points on the mock-up have been recorded for various values of flow rate and magnitude of the imposed magnetic field. The main contributions to the total pressure drop in the test-section have been identified as a function of characteristic flow parameters. For sufficiently strong magnetic fields the non-dimensional pressure losses are practically independent on the flow rate, namely inertia forces become negligible. Previous experiments on MHD flows in a simplified test-section for a HCLL blanket showed that the main contributions to the total pressure drop in a blanket module originate from the flow in the distributing and collecting manifolds. The new experiments confirm that the largest pressure drops occur along manifolds and near the first wall of the blanket module, where the liquid metal passes through small openings in the stiffening plates separating two breeder units. Moreover, the experimental data shows that with the present manifold design the flow does not distribute homogeneously among the 8 stacked boxes that form the breeding zone.

  6. Equations of states for an ionic liquid under high pressure: A molecular dynamics simulation study

    International Nuclear Information System (INIS)

    Ribeiro, Mauro C.C.; Pádua, Agílio A.H.; Gomes, Margarida F.C.

    2014-01-01

    Highlights: • We compare different equation of states, EoS, for an ionic liquid under high pressure. • Molecular dynamics, MD, simulations have been used to evaluate the best EoS. • MD simulations show that a group contribution model can be extrapolated to P ∼ 1.0 GPa. • A perturbed hard-sphere EoS also fits the densities calculated by MD simulations. - Abstract: The high-pressure dependence of density given by empirical equation of states (EoS) for the ionic liquid 1-butyl-3-methylimidazolium trifluoromethanesulfonate (or triflate), [C 4 C 1 im][TfO], is compared with results obtained by molecular dynamics (MD) simulations. Two EoS proposed for [C 4 C 1 im][TfO] in the pressure range of tens of MPa, which give very different densities when extrapolated to pressures beyond the original experiments, are compared with a group contribution model (GCM). The MD simulations provide support that one of the empirical EoS and the GCM is valid in the pressure range of hundreds of MPa. As an alternative to these EoS that are based on modified Tait equations, it is shown that a perturbed hard-sphere EoS based on the Carnahan–Starling–van der Waals equation also fits the densities calculated by MD simulations of [C 4 C 1 im][TfO] up to ∼1.0 GPa

  7. Influence of pressure on the structural properties of liquid D{sub 2}O

    Energy Technology Data Exchange (ETDEWEB)

    Bellissent-Funel, M.C.

    1994-12-31

    Results about the structure of liquid water under pressure and using neutron diffraction are presented. The structural data are compared with that of low density amorphous ice (LDA) and of high density amorphous ice (HDA). The low density amorphous ice which is well accounted for a continuous random network model appears as the limit of deeply supercooled water while the high density amorphous ice which is a more disordered form of ice appears as the limit of water under high pressure and at high temperature. (author). 29 refs., 6 figs.

  8. Generation of high-power-density atmospheric pressure plasma with liquid electrodes

    International Nuclear Information System (INIS)

    Dong Lifang; Mao Zhiguo; Yin Zengqian; Ran Junxia

    2004-01-01

    We present a method for generating atmospheric pressure plasma using a dielectric barrier discharge reactor with two liquid electrodes. Four distinct kinds of discharge, including stochastic filaments, regular square pattern, glow-like discharge, and Turing stripe pattern, are observed in argon with a flow rate of 9 slm. The electrical and optical characteristics of the device are investigated. Results show that high-power-density atmospheric pressure plasma with high duty ratio in space and time can be obtained. The influence of wall charges on discharge power and duty ratio has been discussed

  9. 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.

  10. 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.

  11. Reduction of the suction pressure of a liquid ring vacuum pump with a supersonic gas ejector

    Directory of Open Access Journals (Sweden)

    Olšiak Róbert

    2018-01-01

    Full Text Available A supersonic gas ejector in conjunction with a liquid ring vacuum pump is used for creating and maintaining vacuum in a chamber for technological purposes. In this paper the authors submit an overview about the problematics of suction pressure reduction with a supersonic gas ejector used as a pre-stage of a liquid ring vacuum pump. This system has also the function of a cavitation protection due to the higher pressure present at the suction throat of the vacuum pump. A part of this paper is devoted to the governing equations used at the definition of the flow through an ejector. The experimental studies are then carried out in or own laboratory for verification purposes.

  12. 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.

  13. 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.

  14. 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)

  15. Triggering the Chemical Instability of an Ionic Liquid under High Pressure.

    Science.gov (United States)

    Faria, Luiz F O; Nobrega, Marcelo M; Temperini, Marcia L A; Bini, Roberto; Ribeiro, Mauro C C

    2016-09-01

    Ionic liquids are an interesting class of materials due to their distinguished properties, allowing their use in an impressive range of applications, from catalysis to hypergolic fuels. However, the reactivity triggered by the application of high pressure can give rise to a new class of materials, which is not achieved under normal conditions. Here, we report on the high-pressure chemical instability of the ionic liquid 1-allyl-3-methylimidazolium dicyanamide, [allylC1im][N(CN)2], probed by both Raman and IR techniques and supported by quantum chemical calculations. Our results show a reaction occurring above 8 GPa, involving the terminal double bond of the allyl group, giving rise to an oligomeric product. The results presented herein contribute to our understanding of the stability of ionic liquids, which is of paramount interest for engineering applications. Moreover, gaining insight into this peculiar kind of reactivity could lead to the development of new or alternative synthetic routes to achieve, for example, poly(ionic liquids).

  16. A system for traceable measurement of the microwave complex permittivity of liquids at high pressures and temperatures

    International Nuclear Information System (INIS)

    Dimitrakis, G A; Robinson, J; Kingman, S; Lester, E; George, M; Poliakoff, M; Harrison, I; Gregory, A P; Lees, K

    2009-01-01

    A system has been developed for direct traceable dielectric measurements on liquids at high pressures and temperatures. The system consists of a coaxial reflectometric sensor terminated by a metallic cylindrical cell to contain the liquid. It has been designed for measurements on supercritical liquids, but as a first step measurements on dielectric reference liquids were performed. This paper reports on a full evaluation of the system up to 2.5 GHz using methanol, ethanol and n-propanol at pressures up to 9 MPa and temperatures up to 273 °C. A comprehensive approach to the evaluation of uncertainties using Monte Carlo modelling is used

  17. EDITORIAL: Non-polar and semipolar nitride semiconductors Non-polar and semipolar nitride semiconductors

    Science.gov (United States)

    Han, Jung; Kneissl, Michael

    2012-02-01

    Throughout the history of group-III-nitride materials and devices, scientific breakthroughs and technological advances have gone hand-in-hand. In the late 1980s and early 1990s, the discovery of the nucleation of smooth (0001) GaN films on c-plane sapphire and the activation of p-dopants in GaN led very quickly to the realization of high-brightness blue and green LEDs, followed by the first demonstration of GaN-based violet laser diodes in the mid 1990s. Today, blue InGaN LEDs boast record external quantum efficiencies exceeding 80% and the emission wavelength of the InGaN-based laser diode has been pushed into the green spectral range. Although these tremenduous advances have already spurred multi-billion dollar industries, there are still a number of scientific questions and technological issues that are unanswered. One key challenge is related to the polar nature of the III-nitride wurtzite crystal. Until a decade ago all research activities had almost exclusively concentrated on (0001)-oriented polar GaN layers and heterostructures. Although the device characteristics seem excellent, the strong polarization fields at GaN heterointerfaces can lead to a significant deterioration of the device performance. Triggered by the first demonstration non-polar GaN quantum wells grown on LiAlO2 by Waltereit and colleagues in 2000, impressive advances in the area of non-polar and semipolar nitride semiconductors and devices have been achieved. Today, a large variety of heterostructures free of polarization fields and exhibiting exceptional electronic and optical properties have been demonstrated, and the fundamental understanding of polar, semipolar and non-polar nitrides has made significant leaps forward. The contributions in this Semiconductor Science and Technology special issue on non-polar and semipolar nitride semiconductors provide an impressive and up-to-date cross-section of all areas of research and device physics in this field. The articles cover a wide range of

  18. Two independent measurements of Debye lengths in doped nonpolar liquids.

    Science.gov (United States)

    Prieve, D C; Hoggard, J D; Fu, R; Sides, P J; Bethea, R

    2008-02-19

    Electric current measurements were performed between 2.5 cm x 7.5 cm parallel-plate electrodes separated by 1.2 mm of heptane doped with 0-15% w/w poly(isobutylene succinimide) (PIBS) having a molecular weight of about 1700. The rapid (microsecond) initial charging of the capacitor can be used to infer the dielectric constant of the solution. The much slower decay of current arising from the polarization of electrodes depends on the differential capacitance of the diffuse clouds of charge carriers accumulating next to each electrode and on the ohmic resistance of the fluid. Using the Gouy-Chapman model for the differential capacitance, Debye lengths of 80-600 nm were deduced that decrease with increasing concentration of PIBS. Values of the Debye lengths were confirmed by performing independent measurements of double-layer repulsion between a 6 microm polystyrene (PS) latex sphere and a PS-coated glass plate using total internal reflection microscopy in the same solutions. The charge carriers appear to be inverted PIBS micelles having apparent Stokes diameters of 20-40 nm. Dynamic light scattering reveals a broad distribution of sizes having an intensity-averaged diameter of 15 nm. This smaller size might arise (1) from overestimating the electrophoretic mobility of micelles by treating them as point charges or (2) because charged micelles are larger on average than uncharged micelles. When Faradaic reactions and zeta potentials on the electrodes can be neglected, such current versus time experiments yield values for the Debye length and ionic strength with less effort than force measurements. To obtain the concentration of charge carriers from measurements of conductivity, the mobility of the charge carriers must be known.

  19. Computer simulation of ion recombination in irradiated nonpolar liquids

    International Nuclear Information System (INIS)

    Bartczak, W.M.; Hummel, A.

    1986-01-01

    A review on the results of computer simulation of the diffusion controlled recombination of ions is presented. The ions generated in clusters of two and three pairs of oppositely charged ions were considered. The recombination kinetics and the ion escape probability at infinite time with and without external electric field were computed. These results are compared with the calculations based on the single-pair theory. (athor)

  20. High pressure combustion of liquid fuels. [alcohol and n-paraffin fuels

    Science.gov (United States)

    Canada, G. S.

    1974-01-01

    Measurements were made of the burning rates and liquid surface temperatures for a number of alcohol and n-paraffin fuels under natural and forced convection conditions. Porous spheres ranging in size from 0.64-1.9 cm O.D. were emloyed to simulate the fuel droplets. The natural convection cold gas tests considered the combustion in air of methanol, ethanol, propanol-1, n-pentane, n-heptane, and n-decane droplets at pressures up to 78 atmospheres. The pressure levels of the natural convection tests were high enough so that near critical combustion was observed for methanol and ethanol vaporization rates and liquid surface temperature measurements were made of droplets burning in a simulated combustion chamber environment. Ambient oxygen molar concentrations included 13%, 9.5% and pure evaporation. Fuels used in the forced convection atmospheric tests included those listed above for the natural convection tests. The ambient gas temperature ranged from 600 to 1500 K and the Reynolds number varied from 30 to 300. The high pressure forced convection tests employed ethanol and n-heptane as fuels over a pressure range of one to 40 atmospheres. The ambient gas temperature was 1145 K for the two combustion cases and 1255 K for the evaporation case.

  1. Application of SH surface acoustic waves for measuring the viscosity of liquids in function of pressure and temperature.

    Science.gov (United States)

    Kiełczyński, P; Szalewski, M; Balcerzak, A; Rostocki, A J; Tefelski, D B

    2011-12-01

    Viscosity measurements were carried out on triolein at pressures from atmospheric up to 650 MPa and in the temperature range from 10°C to 40°C using ultrasonic measuring setup. Bleustein-Gulyaev SH surface acoustic waves waveguides were used as viscosity sensors. Additionally, pressure changes occurring during phase transition have been measured over the same temperature range. Application of ultrasonic SH surface acoustic waves in the liquid viscosity measurements at high pressure has many advantages. It enables viscosity measurement during phase transitions and in the high-pressure range where the classical viscosity measurement methods cannot operate. Measurements of phase transition kinetics and viscosity of liquids at high pressures and various temperatures (isotherms) is a novelty. The knowledge of changes in viscosity in function of pressure and temperature can help to obtain a deeper insight into thermodynamic properties of liquids. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Highly pressurized partially miscible liquid-liquid flow in a micro-T-junction. II. Theoretical justifications and modeling

    Science.gov (United States)

    Qin, Ning; Wen, John Z.; Ren, Carolyn L.

    2017-04-01

    This is the second part of a two-part study on a partially miscible liquid-liquid flow (carbon dioxide and deionized water) that is highly pressurized and confined in a microfluidic T-junction. In the first part of this study, we reported experimental observations of the development of flow regimes under various flow conditions and the quantitative characteristics of the drop flow including the drop length, after-generation drop speed, and periodic spacing development between an emerging drop and the newly produced one. Here in part II we provide theoretical justifications to our quantitative studies on the drop flow by considering (1) C O2 hydration at the interface with water, (2) the diffusion-controlled dissolution of C O2 molecules in water, and (3) the diffusion distance of the dissolved C O2 molecules. Our analyses show that (1) the C O2 hydration at the interface is overall negligible, (2) a saturation scenario of the dissolved C O2 molecules in the vicinity of the interface will not be reached within the contact time between the two fluids, and (3) molecular diffusion does play a role in transferring the dissolved molecules, but the diffusion distance is very limited compared with the channel geometry. In addition, mathematical models for the drop length and the drop spacing are developed based on the observations in part I, and their predictions are compared to our experimental results.

  3. Evaluation between ultrahigh pressure liquid chromatography and high-performance liquid chromatography analytical methods for characterizing natural dyestuffs.

    Science.gov (United States)

    Serrano, Ana; van Bommel, Maarten; Hallett, Jessica

    2013-11-29

    An evaluation was undertaken of ultrahigh pressure liquid chromatography (UHPLC) in comparison to high-performance liquid chromatography (HPLC) for characterizing natural dyes in cultural heritage objects. A new UHPLC method was optimized by testing several analytical parameters adapted from prior UHPLC studies developed in diverse fields of research. Different gradient elution programs were tested on seven UHPLC columns with different dimensions and stationary phase compositions by applying several mobile phases, flow rates, temperatures, and runtimes. The UHPLC method successfully provided more improved data than that achieved by the HPLC method. Indeed, even though carminic acid has shown circa 146% higher resolution with HPLC, UHPLC resulted in an increase of 41-61% resolution and a decrease of 91-422% limit of detection, depending on the dye compound. The optimized method was subsequently assigned to analyse 59 natural reference materials, in which 85 different components were ascribed with different physicochemical properties, in order to create a spectral database for future characterization of dyes in cultural heritage objects. The majority of these reference samples could be successfully distinguished with one single method through the examination of these compounds' retention times and their spectra acquired with a photodiode array detector. These results demonstrate that UHPLC analyses are extremely valuable for the acquisition of more precise chromatographic information concerning natural dyes with complex mixtures of different and/or closely related physicochemical properties, essential for distinguishing similar species of plants and animals used to colour cultural heritage objects. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Second sound, osmotic pressure, and Fermi-liquid parameters in 3He-4He solutions

    International Nuclear Information System (INIS)

    Corruccini, L.R.

    1984-01-01

    Second-sound velocities and osmotic pressures are analyzed to obtain the first experimental values for the Landau compressibility parameter F 0 /sup s/ in 3 He- 4 He solutions. Data are presented as a function of pressure and 3 He concentration, and are compared to theoretical predictions. The square of the second-sound velocity at finite temperature is found to be accurately proportional to the internal energy of a perfect Fermi gas. Using inertial effective masses given by the Landau-Pomeranchuk theory, the square of the velocity is found to separate into two parts: a temperature-dependent part characterized completely by ideal Fermi-gas behavior and a temperature-independent part containing all the Fermi-liquid corrections. This is related to a similar separation found in the osmotic pressure

  5. Prediction of Osmotic Pressure of Ionic Liquids Inside a Nanoslit by MD Simulation and Continuum Approach

    Science.gov (United States)

    Moon, Gi Jong; Yang, Yu Dong; Oh, Jung Min; Kang, In Seok

    2017-11-01

    Osmotic pressure plays an important role in the processes of charging and discharging of lithium batteries. In this work, osmotic pressure of the ionic liquids confined inside a nanoslit is calculated by using both MD simulation and continuum approach. In the case of MD simulation, an ionic liquid is modeled as singly charged spheres with a short-ranged repulsive Lennard-Jones potential. The radii of the spheres are 0.5nm, reflecting the symmetry of ion sizes for simplicity. The simulation box size is 11nm×11nm×7.5nm with 1050 ion pairs. The concentration of ionic liquid is about 1.922mol/L, and the total charge on an individual wall varies from +/-60e(7.944 μm/cm2) to +/-600e(79.44 μm/cm2) . In the case of continuum approach, we classify the problems according to the correlation length and steric factor, and considered the four separate cases: 1) zero correlation length and zero steric factor, 2) zero correlation length and non-zero steric factor, 3) non-zero correlation length and zero steric factor, and 4) non-zero correlation and non-zero steric factor. Better understanding of the osmotic pressure of ionic liquids confined inside a nanoslit can be achieved by comparing the results of MD simulation and continuum approach. This research was supported by the National Research Foundation of Korea (NRF) Grant funded by the Korea government (MSIP: Ministry of Science, ICT & Future Planning) (No. 2017R1D1A1B05035211).

  6. Determination of carbohydrates in tobacco by pressurized liquid extraction combined with a novel ultrasound-assisted dispersive liquid-liquid microextraction method.

    Science.gov (United States)

    Cai, Kai; Hu, Deyu; Lei, Bo; Zhao, Huina; Pan, Wenjie; Song, Baoan

    2015-07-02

    A novel derivatization-ultrasonic assisted-dispersive liquid-liquid microextraction (UA-DLLME) method for the simultaneous determination of 11 main carbohydrates in tobacco has been developed. The combined method involves pressurized liquid extraction (PLE), derivatization, and UA-DLLME, followed by the analysis of the main carbohydrates with a gas chromatography-flame ionization detector (GC-FID). First, the PLE conditions were optimized using a univariate approach. Then, the derivatization methods were properly compared and optimized. The aldononitrile acetate method combined with the O-methoxyoxime-trimethylsilyl method was used for derivatization. Finally, the critical variables affecting the UA-DLLME extraction efficiency were searched using fractional factorial design (FFD) and further optimized using Doehlert design (DD) of the response surface methodology. The optimum conditions were found to be 44 μL for CHCl3, 2.3 mL for H2O, 11% w/v for NaCl, 5 min for the extraction time and 5 min for the centrifugation time. Under the optimized experimental conditions, the detection limit of the method (LODs) and linear correlation coefficient were found to be in the range of 0.06-0.90 μg mL(-1) and 0.9987-0.9999. The proposed method was successfully employed to analyze three flue-cured tobacco cultivars, among which the main carbohydrate concentrations were found to be very different. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Vapour pressures and osmotic coefficients of binary mixtures containing alcohol and pyrrolidinium-based ionic liquids

    International Nuclear Information System (INIS)

    Calvar, N.; Domínguez, Á.; Macedo, E.A.

    2013-01-01

    Highlights: • Osmotic coefficients of alcohols with pyrrolidinium ILs are determined. • Experimental data were correlated with extended Pitzer model of Archer and MNRTL. • Mean molal activity coefficients and excess Gibbs free energies were calculated. • The results have been interpreted in terms of interactions. -- Abstract: The osmotic and activity coefficients and vapour pressures of mixtures containing primary (1-propanol, 1-butanol and 1-pentanol) and secondary (2-propanol and 2-butanol) alcohols with pyrrolidinium-based ionic liquids (1-butyl-1-methyl pyrrolidinium bis(trifluoromethylsulfonyl)imide, C 4 MpyrNTf 2 , and 1-butyl-1-methyl pyrrolidinium trifluoromethanesulfonate, C 4 MpyrTFO) have been experimentally determined at T = 323.15 K. For the experimental measurements, the vapour pressure osmometry technique has been used. The results on the influence of the structure of the alcohol and of the anion of the ionic liquid on the determined properties have been discussed and compared with literature data. For the correlation of the osmotic coefficients obtained, the Extended Pitzer model of Archer and the Modified Non-Random Two Liquids model were applied. The mean molal activity coefficients and the excess Gibbs energy for the studied mixtures were calculated from the parameters obtained in the correlation

  8. The study of diffusion in network-forming liquids under pressure and temperature

    Energy Technology Data Exchange (ETDEWEB)

    Hung, P.K. [Department of Computational Physics, Hanoi University of Technology, 1Dai Co Viet, Hanoi (Viet Nam); Kien, P.H., E-mail: phkien80@gmail.com [Department of Physics, Thainguyen University of Education, 20 Luong Ngoc Quyen, Thainguyen (Viet Nam); San, L.T.; Hong, N.V. [Department of Computational Physics, Hanoi University of Technology, 1Dai Co Viet, Hanoi (Viet Nam)

    2016-11-15

    In this paper, the molecular dynamics simulation is applied to investigate the diffusion in silica liquids under different temperature and pressure. We show that the diffusion is controlled by the rate of effective SiO{sub x}→SiO{sub x±1} and OSi{sub y}→OSi{sub y±1} reaction. With increasing the pressure, the rate of reaction increases and the Si–O bond is weaker. Moreover, the reactions are not uniformly distributed in the space, but instead they happen frequently or rarely in separate regions. We also reveal two motion types: free and correlation motion. The correlation motion concerns the moving of a group of atoms which is similar to that of the diffusion of a super-molecule in the liquid. A detailed analysis of the movement of atoms from specified set shows the clustering of them which indicates structure and dynamics heterogeneity. Further, we find that the correlation motion is very important for the diffusion in network-forming liquid. The observed phenomena such as diffusion anomaly, dynamics heterogeneity and dynamical slowdown are originated from the correlation motion of atom.

  9. Pressure and surface tension of solid-liquid interface using Tara zona density functional theory

    International Nuclear Information System (INIS)

    Moradi, M.; Kavosh Tehrani, M.

    2001-01-01

    The weighted density functional theory proposed by Tara zona is applied to study the solid-liquid interface. In the last two decades the weighted density functional became a useful tool to consider the properties of inhomogeneous liquids. In this theory, the role of the size of molecules or the particles of which the matter is composed, was found to be important. In this research we study a hard sphere fluid beside a hard wall. For this study the liquid is an inhomogeneous system. We use the definition of the direct correlation function as a second derivative of free energy with respect to the density. We use this definition and the definition of the weighting function, then we minimize the grand potential with respect to the density to get the Euler Lagrange equation and we obtain an integral equation to find the inhomogeneous density profile. The obtained density profile as a function of the distance from the wall, for different bulk density is pitted in three dimensions. We also calculate the pressure and compare it with the Carnahan-Starling results, and finally we obtained the surface tension at liquid-solid interface and compared it with the results of Monte Carlo simulation

  10. Generation of reactive species in atmospheric pressure dielectric barrier discharge with liquid water

    Science.gov (United States)

    Zelong, ZHANG; Jie, SHEN; Cheng, CHENG; Zimu, XU; Weidong, XIA

    2018-04-01

    Atmospheric pressure helium/water dielectric barrier discharge (DBD) plasma is used to investigate the generation of reactive species in a gas-liquid interface and in a liquid. The emission intensity of the reactive species is measured by optical emission spectroscopy (OES) with different discharge powers at the gas-liquid interface. Spectrophotometry is used to analyze the reactive species induced by the plasma in the liquid. The concentration of OH radicals reaches 2.2 μm after 3 min of discharge treatment. In addition, the concentration of primary long-lived reactive species such as H2O2, {{{{NO}}}3}- and O3 are measured based on plasma treatment time. After 5 min of discharge treatment, the concentration of H2O2, {{{{NO}}}3}-, and O3 increased from 0 mg · L-1 to 96 mg · L-1, 19.5 mg · L-1, and 3.5 mg · L-1, respectively. The water treated by plasma still contained a considerable concentration of reactive species after 6 h of storage. The results will contribute to optimizing the DBD plasma system for biological decontamination.

  11. Pressure and surface tension of soild-liquid interface using Tarazona density functional theory

    Directory of Open Access Journals (Sweden)

    M. M.

    2000-12-01

    Full Text Available   The weighted density functional theory proposed by Tarazona is applied to study the solid-liquid interface. In the last two decades the weighted density functional became a useful tool to consider the properties of inhomogeneous liquids. In this theory, the role of the size of molecules or the particles of which the matter is composed, was found to be important. In this resarch we study a hard sphere fluid beside a hard wall. For this study the liquid is an inhomogeneous system. We use the definition of the direct correlation function as a second derivative of free energy with respect to the density. We use this definition and the definition of the weighting function, then we minimize the grand potential with respect to the density to get the Euler Lagrange equation and we obtain an integral equation to find the inhomogeneous density profile. The obtained density profile as a function of the distance from the wall, for different bulk density is plotted in three dimensions. We also calculate the pressure and compare it with the Carnahan-starling results, and finally we obtained the surface tension at liquid-solid interface and compared it with the results of Monte Carlo simulation.

  12. 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.

  13. Thermodynamic properties by Equation of state of liquid sodium under pressure

    Science.gov (United States)

    Li, Huaming; Sun, Yongli; Zhang, Xiaoxiao; Li, Mo

    Isothermal bulk modulus, molar volume and speed of sound of molten sodium are calculated through an equation of state of a power law form within good precision as compared with the experimental data. The calculated internal energy data show the minimum along the isothermal lines as the previous result but with slightly larger values. The calculated values of isobaric heat capacity show the unexpected minimum in the isothermal compression. The temperature and pressure derivative of various thermodynamic quantities in liquid Sodium are derived. It is discussed about the contribution from entropy to the temperature and pressure derivative of isothermal bulk modulus. The expressions for acoustical parameter and nonlinearity parameter are obtained based on thermodynamic relations from the equation of state. Both parameters for liquid Sodium are calculated under high pressure along the isothermal lines by using the available thermodynamic data and numeric derivations. By comparison with the results from experimental measurements and quasi-thermodynamic theory, the calculated values are found to be very close at melting point at ambient condition. Furthermore, several other thermodynamic quantities are also presented. Scientific Research Starting Foundation from Taiyuan university of Technology, Shanxi Provincial government (``100-talents program''), China Scholarship Council and National Natural Science Foundation of China (NSFC) under Grant No. 11204200.

  14. Supercooled liquid vapour pressures and related thermodynamic properties of polycyclic aromatic hydrocarbons determined by gas chromatography.

    Science.gov (United States)

    Haftka, Joris J H; Parsons, John R; Govers, Harrie A J

    2006-11-24

    A gas chromatographic method using Kováts retention indices has been applied to determine the liquid vapour pressure (P(i)), enthalpy of vaporization (DeltaH(i)) and difference in heat capacity between gas and liquid phase (DeltaC(i)) for a group of polycyclic aromatic hydrocarbons (PAHs). This group consists of 19 unsubstituted, methylated and sulphur containing PAHs. Differences in log P(i) of -0.04 to +0.99 log units at 298.15K were observed between experimental values and data from effusion and gas saturation studies. These differences in log P(i) have been fitted with multilinear regression resulting in a compound and temperature dependent correction. Over a temperature range from 273.15 to 423.15K, differences in corrected log P(i) of a training set (-0.07 to +0.03 log units) and a validation set (-0.17 to 0.19 log units) were within calculated error ranges. The corrected vapour pressures also showed a good agreement with other GC determined vapour pressures (average -0.09 log units).

  15. Design of a high-pressure circulating pump for viscous liquids.

    Science.gov (United States)

    Seifried, Bernhard; Temelli, Feral

    2009-07-01

    The design of a reciprocating dual action piston pump capable of circulating viscous fluids at pressures of up to 34 MPa (5000 psi) and temperatures up to 80 degrees C is described. The piston of this pump is driven by a pair of solenoids energized alternatively by a 12 V direct current power supply controlled by an electronic controller facilitating continuously adjustable flow rates. The body of this seal-less pump is constructed using off-the-shelf parts eliminating the need for custom made parts. Both the electronic controller and the pump can be assembled relatively easily. Pump performance has been evaluated at room temperature (22 degrees C) and atmospheric pressure using liquids with low and moderately high viscosities, such as ethanol and corn oil, respectively. At ambient conditions, the pump delivered continuous flow of ethanol and corn oil at a flow rate of up to 170 and 17 cm3/min, respectively. For pumping viscous fluids comparable to corn oil, an optimum reciprocation frequency was ascertained to maximize flow rate. For low viscosity liquids such as ethanol, a linear relationship between the flow rate and reciprocation frequency was determined up to the maximum reciprocation frequency of the pump. Since its fabrication, the pump has been used in our laboratory for circulating triglycerides in contact with supercritical carbon dioxide at pressures of up to 25 MPa (3600 psi) and temperatures up to 70 degrees C on a daily basis for a total of more than 1500 h of operation functioning trouble free.

  16. 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

  17. Elucidating the existence of the excess wing in an ionic liquid on applying pressure

    Energy Technology Data Exchange (ETDEWEB)

    Rivera-Calzada, A; Leon, C [GFMC, Departamento de Fisica Aplicada 3, Universidad Complutense de Madrid (Spain); Kaminski, K; Paluch, M [Institute of Physics, Silesian University, Katowice (Poland)], E-mail: Alberto.Rivera@fis.ucm.es

    2008-06-18

    We report a study of the dynamic relaxation spectra of the ionic liquid 1-butyl-1-methylpyrrolidinium bis[oxalato]borate (BMP-BOB) by means of dielectric spectroscopy in wide temperature (123-300 K) and pressure (0.1-500 MPa) ranges. We find similar features to those observed in many conventional glass formers. The relaxation time of the primary relaxation {tau}{sub {alpha}} strongly increases with applied pressure, while that of the secondary relaxation is almost insensitive to pressure. However, the shape of the primary relaxation at constant {tau}{sub {alpha}} is the same whether the pressure is 0.1 or 500 MPa. Elevated pressure separates the secondary relaxation and makes possible the appearance of an excess wing on the high-frequency flank of the primary relaxation. Interestingly, the primitive relaxation time calculated by the coupling model falls in the range of the existence of the excess wing of BMP-BOB, suggesting an unresolved universal Johari-Goldstein {beta}-relaxation.

  18. Modeling the pressure increase in liquid helium cryostats after failure of the insulating vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Heidt, C.; Grohmann, S. [Karlsruhe Institute of Technology, Institute for Technical Physics, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany and Karlsruhe Institute of Technology, Institute for Technical Thermodynamics and Refrigeration, Engler-Bunte (Germany); Süßer, M. [Karlsruhe Institute of Technology, Institute for Technical Physics, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany)

    2014-01-29

    The pressure relief system of liquid helium cryostats requires a careful design, due to helium's low enthalpy of vaporization and due to the low operating temperature. Hazard analyses often involve the failure of the insulating vacuum in the worst-case scenario. The venting of the insulating vacuum and the implications for the pressure increase in the helium vessel, however, have not yet been fully analyzed. Therefore, the dimensioning of safety devices often requires experience and reference to very few experimental data. In order to provide a better foundation for the design of cryogenic pressure relief systems, this paper presents an analytic approach for the strongly dynamic process induced by the loss of insulating vacuum. The model is based on theoretical considerations and on differential equation modeling. It contains only few simplifying assumptions, which will be further investigated in future experiments. The numerical solutions of example calculations are presented with regard to the heat flux into the helium vessel, the helium pressure increase and the helium flow rate through the pressure relief device. Implications concerning two-phase flow and the influence of kinetic energy are discussed.

  19. The optimization of extraction of antioxidants from apple pomace by pressurized liquids.

    Science.gov (United States)

    Wijngaard, Hilde; Brunton, Nigel

    2009-11-25

    Pressurized liquid extraction (PLE) is a green extraction technique that can enhance extraction rates of bioactive compounds. PLE was used to extract antioxidants and polyphenols from industrially generated apple pomace at two different temperature ranges: 160 to 193 degrees C and 75 to 125 degrees C. Antioxidant activity (DPPH radical scavenging test), total phenol content and three individual polyphenol groups were determined. Response surface methodology was used to optimize the five response values. Maximum antioxidant activity was obtained at a temperature of 200 degrees C, but unwanted compounds such as hydroxymethylfurfural were formed. Therefore a lower temperature range between 75 and 125 degrees C is recommended. Using this temperature range, a maximum antioxidant activity was determined at 60% ethanol and 102 degrees C. By using PLE the antioxidant activity was increased 2.4 times in comparison to traditional solid-liquid extraction, and the technique may be a promising alternative to conventional techniques for extracting antioxidants.

  20. Raman study of pressure effects on frequencies and isotropic line shapes in liquid acetone

    International Nuclear Information System (INIS)

    Schindler, W.; Sharko, P.T.; Jonas, J.

    1982-01-01

    The Raman line shape of the symmetric C = O stretching band at 1710 cm -1 has been measured in liquid acetone as a function of pressure from 1 bar to 4 kbar over the temperature range from -25 to 50 0 C. The experimental data obtained show several unusual features. First, there is a frequency difference of about 7 cm -1 between the polarized and depolarized components. Sceond, the isotropic linewidth GAMMA/sub iso/ decreases with increasing density, in contrast to the opposite trend usually found in other liquids. Third, the second moment M 2 (V) of the isotropic band appears to decrease with increasing density. The consideration of the experimental linewidth and frequency data leads to a conclusion that intermolecular dipole--dipole coupling between polar acetone molecules are responsible for the observed unusual behavior of , GAMMA/sub iso/, and M 2

  1. Simplified Methodology to Estimate the Maximum Liquid Helium (LHe) Cryostat Pressure from a Vacuum Jacket Failure

    Science.gov (United States)

    Ungar, Eugene K.; Richards, W. Lance

    2015-01-01

    The aircraft-based Stratospheric Observatory for Infrared Astronomy (SOFIA) is a platform for multiple infrared astronomical observation experiments. These experiments carry sensors cooled to liquid helium temperatures. The liquid helium supply is contained in large (i.e., 10 liters or more) vacuum-insulated dewars. Should the dewar vacuum insulation fail, the inrushing air will condense and freeze on the dewar wall, resulting in a large heat flux on the dewar's contents. The heat flux results in a rise in pressure and the actuation of the dewar pressure relief system. A previous NASA Engineering and Safety Center (NESC) assessment provided recommendations for the wall heat flux that would be expected from a loss of vacuum and detailed an appropriate method to use in calculating the maximum pressure that would occur in a loss of vacuum event. This method involved building a detailed supercritical helium compressible flow thermal/fluid model of the vent stack and exercising the model over the appropriate range of parameters. The experimenters designing science instruments for SOFIA are not experts in compressible supercritical flows and do not generally have access to the thermal/fluid modeling packages that are required to build detailed models of the vent stacks. Therefore, the SOFIA Program engaged the NESC to develop a simplified methodology to estimate the maximum pressure in a liquid helium dewar after the loss of vacuum insulation. The method would allow the university-based science instrument development teams to conservatively determine the cryostat's vent neck sizing during preliminary design of new SOFIA Science Instruments. This report details the development of the simplified method, the method itself, and the limits of its applicability. The simplified methodology provides an estimate of the dewar pressure after a loss of vacuum insulation that can be used for the initial design of the liquid helium dewar vent stacks. However, since it is not an exact

  2. Shock Compression of Liquid Noble Gases to Multi-Mbar Pressures

    Science.gov (United States)

    Root, Seth

    2011-10-01

    The high pressure - high temperature behavior of noble gases is of considerable interest because of their use in z-pinch liners for fusion studies and for understanding astrophysical and planetary evolution. However, our understanding of the equation of state (EOS) of the noble gases at extreme conditions is limited. A prime example of this is the liquid xenon Hugoniot. Previous EOS models rapidly diverged on the Hugoniot above 1 Mbar because of differences in the treatment of the electronic contribution to the free energy. Similar divergences are observed for krypton EOS. Combining shock compression experiments and density functional theory (DFT) simulations, we can determine the thermo-physical behavior of matter under extreme conditions. The experimental and DFT results have been instrumental to recent developments in planetary astrophysics and inertial confinement fusion. Shock compression experiments are performed using Sandia's Z-Accelerator to determine the Hugoniot of liquid xenon and krypton in the Mbar regime. Under strong pressure, krypton and xenon undergo an insulator to metal transition. In the metallic state, the shock front becomes reflective allowing for a direct measurement of the sample's shock velocity using laser interferometry. The Hugoniot state is determined using a Monte Carlo analysis method that accounts for systematic error in the standards and for correlations. DFT simulations at these extreme conditions show good agreement with the experimental data - demonstrating the attention to detail required for dealing with elements with relativistic core states and d-state electrons. The results from shock compression experiments and DFT simulations are presented for liquid xenon to 840 GPa and for liquid krypton to 800 GPa, decidedly increasing the range of known behavior of both gases. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company

  3. Electric Charge Accumulation in Polar and Non-Polar Polymers under Electron Beam Irradiation

    Science.gov (United States)

    Nagasawa, Kenichiro; Honjoh, Masato; Takada, Tatsuo; Miyake, Hiroaki; Tanaka, Yasuhiro

    The electric charge accumulation under an electron beam irradiation (40 keV and 60 keV) was measured by using the pressure wave propagation (PWP) method in the dielectric insulation materials, such as polar polymeric films (polycarbonate (PC), polyethylene-naphthalate (PEN), polyimide (PI), and polyethylene-terephthalate (PET)) and non-polar polymeric films (polystyrene (PS), polypropylene (PP), polyethylene (PE) and polytetrafluoroethylene (PTFE)). The PE and PTFE (non-polar polymers) showed the properties of large amount of electric charge accumulation over 50 C/m3 and long saturation time over 80 minutes. The PP and PS (non-polar polymer) showed the properties of middle amount of charge accumulation about 20 C/m3 and middle saturation time about 1 to 20 minutes. The PC, PEN, PI and PET (polar polymers) showed the properties of small amount of charge accumulation about 5 to 20 C/m3 and within short saturation time about 1.0 minutes. This paper summarizes the relationship between the properties of charge accumulation and chemical structural formula, and compares between the electro static potential distribution with negative charged polymer and its chemical structural formula.

  4. Electric charge accumulation in polar and non-polar polymers under electron beam irradiation

    International Nuclear Information System (INIS)

    Nagasawa, Kenichiro; Honjoh, Masato; Takada, Tatsuo; Miyake, Hiroaki; Tanaka, Yasuhiro

    2010-01-01

    The electric charge accumulation under an electron beam irradiation (40 keV and 60 keV) was measured by using the pressure wave propagation (PWP) method in the dielectric insulation materials, such as polar polymeric films (polycarbonate (PC), polyethylene-naphthalate (PEN), polyimide (PI), and polyethylene-terephthalate (PET)) and non-polar polymeric films (polystyrene (PS), polypropylene (PP), polyethylene (PE) and polytetrafluoroethylene (PTFE)). The PE and PTFE (non-polar polymers) showed the properties of large amount of electric charge accumulation over 50 C/m 3 and long saturation time over 80 minutes. The PP and PS (non-polar polymer) showed the properties of middle amount of charge accumulation about 20 C/m 3 and middle saturation time about 1 to 20 minutes. The PC, PEN, PI and PET (polar polymers) showed the properties of small amount of charge accumulation about 5 to 20 C/m 3 and within short saturation time about 1.0 minutes. This paper summarizes the relationship between the properties of charge accumulation and chemical structural formula, and compares between the electro static potential distribution with negative charged polymer and its chemical structural formula. (author)

  5. Optimisation of pressurized liquid extraction using a multivariate chemometric approach for the determination of anticancer drugs in sludge by ultra high performance liquid chromatography-tandem mass spectrometry

    OpenAIRE

    Seira , Jordan; Claparols , Catherine; Joannis-Cassan , Claire; Albasi , Claire; Montréjaud-Vignoles , Mireille; Sablayrolles , Caroline

    2013-01-01

    International audience; The present paper describes an analytical method for the determination of 2 widely administered anticancer drugs, ifosfamide and cyclophosphamide, contained in sewage sludge. The method relies on the extraction from the solid matrix by pressurized liquid extraction, sample purification by solid-phase extraction and analysis by ultra high performance liquid chromatography coupled with tandem mass spectrometry. The different parameters affecting the extraction efficiency...

  6. Determination of boron in uranium and aluminium by high pressure liquid chromatography (HPLC)

    International Nuclear Information System (INIS)

    Rao, Radhika M.; Aggarwal, S.K.

    2003-01-01

    Experiments were conducted for the determination of boron in U 3 O 8 powder and aluminium metal using dynamically modified reversed phase high pressure liquid chromatography (RP-HPLC) and using precolumn chromogenic agent viz. curcumin for complexing boron. The complex was separated from the excess of reagent and determined by HPLC. The boron curcumin complex (rosocyanin) was formed after extraction of boron with 2-ethyl-1,3-hexane diol (EHD). Linear calibration curves for boron amounts in the range of 0.02 μg to 0.5 μg were developed and used for the determination of boron in aluminium and uranium samples. (author)

  7. Means of introducing an analyte into liquid sampling atmospheric pressure glow discharge

    Science.gov (United States)

    Marcus, R. Kenneth; Quarles, Jr., Charles Derrick; Russo, Richard E.; Koppenaal, David W.; Barinaga, Charles J.; Carado, Anthony J.

    2017-01-03

    A liquid sampling, atmospheric pressure, glow discharge (LS-APGD) device as well as systems that incorporate the device and methods for using the device and systems are described. The LS-APGD includes a hollow capillary for delivering an electrolyte solution to a glow discharge space. The device also includes a counter electrode in the form of a second hollow capillary that can deliver the analyte into the glow discharge space. A voltage across the electrolyte solution and the counter electrode creates the microplasma within the glow discharge space that interacts with the analyte to move it to a higher energy state (vaporization, excitation, and/or ionization of the analyte).

  8. Corona discharge secondary ionization of laser desorbed neutral molecules from a liquid matrix at atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Turney, Kevin [Department of Chemistry, University of Florida, Gainesville, Florida 32611 (United States); Harrison, W.W. [Department of Chemistry, University of Florida, Gainesville, Florida 32611 (United States)]. E-mail: harrison@chem.ufl.edu

    2006-06-15

    Matrix assisted laser desorption/ionization (MALDI) is studied at atmospheric pressure using liquid sampling methods. A time-of-flight mass spectrometer couples to an open sample stage accessed by a UV laser for desorption and ionization. Also coupled to the sampling state is a corona discharge for auxiliary ionization of desorbed neutral molecules. The interaction of the laser desorption and corona ionization is studied for a range of desorption conditions, showing enhanced analyte ionization, but the effect is analytically advantageous only at low desorption rates. The effect of corona discharge voltage was also explored. The decoupling of neutral molecule formation and subsequent ionization provides an opportunity to study each process separately.

  9. Corona discharge secondary ionization of laser desorbed neutral molecules from a liquid matrix at atmospheric pressure

    International Nuclear Information System (INIS)

    Turney, Kevin; Harrison, W.W.

    2006-01-01

    Matrix assisted laser desorption/ionization (MALDI) is studied at atmospheric pressure using liquid sampling methods. A time-of-flight mass spectrometer couples to an open sample stage accessed by a UV laser for desorption and ionization. Also coupled to the sampling state is a corona discharge for auxiliary ionization of desorbed neutral molecules. The interaction of the laser desorption and corona ionization is studied for a range of desorption conditions, showing enhanced analyte ionization, but the effect is analytically advantageous only at low desorption rates. The effect of corona discharge voltage was also explored. The decoupling of neutral molecule formation and subsequent ionization provides an opportunity to study each process separately

  10. Determination of sulfonamides in meat by liquid chromatography coupled with atmospheric pressure chemical ionization mass spectrometry

    International Nuclear Information System (INIS)

    Kim, Dal Ho; Choi, Jong Oh; Kim, Jin Seog; Lee, Dai Woon

    2002-01-01

    Liquid chromatography/atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MS) has been used for the determination of sulfonamides in meat. Five typical sulfonamides were selected as target compounds, and beef meat was selected as a matrix sample. As internal standards, sulfapyridine and isotope labeled sulfamethazine ( 13 C 6 -SMZ) were used. Compared to the results of recent reports, our results have shown improved precision to a RSD of 1.8% for the determination of sulfamethazine spiked with 75 ng/g level in meat

  11. Computer-assisted high-pressure liquid chromatography of radio-labelled phenylthiohydantoin amino acids

    International Nuclear Information System (INIS)

    Bhown, A.S.; Mole, J.E.; Hollaway, W.L.; Bennet, J.C.

    1978-01-01

    A computer-controlled high-pressure liquid chromatographic (HPLC) system is described to identify in vitro phenyl [ 35 S]isothiocyanate-labelled phenylthiohydantoin (PTH) amino acids from a solid-phase sequencer. Each radio-labelled amino acid from the sequencer is added to a PTH amino acid standard and the mixture separated by HPLC using a computer, programmed to detect a slope change in the absorbance. Individual fractions corresponding to the PTH amino acids are collected and counted. The sensitivity of the system is demonstrated on 700 pmoles of lysozyme. (Auth.)

  12. High-pressure liquid chromatographic determination of chlorphenesin carbamate and the beta-isomeric carbamate.

    Science.gov (United States)

    Beyer, W F

    1976-12-01

    A high-pressure liquid chromatographic assay was developed for the determination of chlorphenesin carbamate and its beta-isomeric carbamate. A single 4-mm i.d. X 30-cm column, prepacked with 10 micrometer fully porous silica gel particles, is used with 3% methanol in 50% water-saturated butyl chloride as the mobile phase. The procedure separates chlorphenesin carbamate from several possible impurities in addition to the beta-isomeric carbamate. The assay was applied to bulk drug and compressed tablets. The relative standard deviations for the assays of chlorphenesin carbamate and the beta-isomer are approximately 1 and 2%, respectively.

  13. High-pressure liquid chromatographic analysis of pramoxine hydrochloride in high lipoid aerosol foam dosage form.

    Science.gov (United States)

    Weinberger, R; Mann, B; Posluszny, J

    1980-04-01

    A rapid and quantitative method for the determination of pramoxine hydrochloride by high-pressure liquid chromatography is presented. The drug is extracted as the salt from a preparation with a high lipoid composition by partitioning it to the aqueous phase of an ether-methanol-water-acetic acid system. The extract is chromatographed on an octadecylsilane bonded packing with a methanol-water-acetic acid-methanesulfonic acid mobile phase. The time required for each separation is approximately 6 min. Analytical recoveries of 100.4 +/- 1.5% were obtained.

  14. Development of an improved-contact liquid-level probe for pressurized reactor vessels

    International Nuclear Information System (INIS)

    Kelsey, P.V. Jr.

    1982-09-01

    Electrical-conductivity-based probes for liquid level sensing show promise for pressurized water reactor environments, but have exhibited frequent bond failures at the ceramic/metal interfaces. A program to characterize and improve the interface behavior has been completed successfully, and has provided data for optimizing fabrication parameters, as well as general information on glass-to-metal bonding in a superalloy/silicate-glass system. The materials studied were Inconel X-750 and a barium silicate glass containing minor amounts of TiO 2 , CeO 2 , As 2 O 3 , Bi 2 O 3 , and Al 2 O 3

  15. On the viscosity of two 1-butyl-1-methylpyrrolidinium ionic liquids: effect of the temperature and pressure

    DEFF Research Database (Denmark)

    Gaciño, Félix M.; Comuñas, María J.P.; Regueira Muñiz, Teresa

    2015-01-01

    to measure viscosities as a function of temperature and pressure fortwo ionic liquids (ILs): 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl)trifluorophosphateand 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate.Besides, we have measured the flow curves at pressures up to 75 MPa and shear rates up...

  16. Elastomeric Sensing of Pressure with Liquid Metal and Wireless Inductive Coupling

    Science.gov (United States)

    Dick, Jacob; Zou, Xiyue; Hogan, Ben; Tumalle, Jonathan; Etikyala, Sowmith; Fung, Diego; Charles, Watley; Gu, Tianye; Hull, Patrick V.; Mazzeo, Aaron D.

    2017-01-01

    This project describes resistance-based soft sensors filled with liquid metal, which permit measurements of large strains (0 percent to 110 percent), associated with small forces of less than 30 Newtons. This work also demonstrates a methodology for wireless transfer of these strain measurements without connected electrodes. These sensors allow intermittent detection of pressure on soft membranes with low force. Adapting these sensors for passive wireless pressure sensing will eliminate the need for embedded batteries, and will allow the sensors to transmit pressure data through non-conductive materials including glass and acrylic. The absence of batteries allows us to embed these sensors into materials for long-term use because the sensors only use passive analog circuit elements. We found the oxidation of the liquid metal (eutectic gallium indium) plays a role in the repeatability of the soft sensors. We investigated how the oxidation layer affected the behavior of the sensor by encapsulating materials (silicone, fluorosilicone, and PVC) with varied permeabilities to oxygen. We measured the effects of mechanical loading on the oxidation layer and the effects of wireless inductive coupling on the oxidation layer. We concluded our research by investigating the effects of embedding self-resonant circuits into polydimethylsiloxane (PDMS). Efforts to design engineered systems with soft materials are a growing field with progress in soft robotics, epidermal electronics, and wearable electronics. In the field of soft robotics, PDMS-based grippers are capable of picking up delicate objects because their form-fitting properties allow them to conform to the shape of objects more easily than conventional robotic grippers. Epidermal devices also use PDMS as a substrate to hold electronic components such as radios, sensors, and power supply circuits. Additionally, PDMS-based soft sensors can monitor human motion with liquid metal embedded within micro-channels. Passive

  17. 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.)

  18. (Liquid + liquid) equilibrium data for the ternary systems (cycloalkane + ethylbenzene + 1-ethyl-3-methylimidazolim ethylsulfate) at T = 298.15 K and atmospheric pressure

    International Nuclear Information System (INIS)

    Gonzalez, Emilio J.; Calvar, Noelia; Dominguez, Irene; Dominguez, Angeles

    2011-01-01

    Research highlights: → [EMim][ESO 4 ] was studied as solvent to extract ethylbenzene from cycloalkanes. → (Liquid + liquid) equilibrium data were measured at 298.15K and atmospheric pressure. → Selectivity and solute distribution ratio were obtained and compared with literature. → Experimental data were satisfactorily correlated using NRTL and UNIQUAC models. → [EMim][ESO 4 ] can be used as solvent for the studied (liquid + liquid) extraction. - Abstract: In this paper, (liquid + liquid) equilibrium (LLE) data for the ternary systems (cyclohexane, or cyclooctane, or methylcyclohexane + ethylbenzene + 1-ethyl-3-methylimidazolium ethylsulfate) have been determined experimentally at T = 298.15 K and atmospheric pressure. The solubility curves and the tie-line compositions of the conjugate phases were obtained by means of density. The degree of consistency of the tie-lines was tested using the Othmer-Tobias equation, and the Non-Random Two-Liquid (NRTL) and the Universal Quasi-Chemical (UNIQUAC) models were used to correlate the phase equilibrium in the systems. Selectivity and solute distribution ratio were evaluated for the immiscible region.

  19. A flexible liquid crystal polymer MEMS pressure sensor array for fish-like underwater sensing

    International Nuclear Information System (INIS)

    Kottapalli, A G P; Asadnia, M; Miao, J M; Barbastathis, G; Triantafyllou, M S

    2012-01-01

    In order to perform underwater surveillance, autonomous underwater vehicles (AUVs) require flexible, light-weight, reliable and robust sensing systems that are capable of flow sensing and detecting underwater objects. Underwater animals like fish perform a similar task using an efficient and ubiquitous sensory system called a lateral-line constituting of an array of pressure-gradient sensors. We demonstrate here the development of arrays of polymer microelectromechanical systems (MEMS) pressure sensors which are flexible and can be readily mounted on curved surfaces of AUV bodies. An array of ten sensors with a footprint of 60 (L) mm × 25 (W) mm × 0.4 (H) mm is fabricated using liquid crystal polymer (LCP) as the sensing membrane material. The flow sensing and object detection capabilities of the array are illustrated with proof-of-concept experiments conducted in a water tunnel. The sensors demonstrate a pressure sensitivity of 14.3 μV Pa −1 . A high resolution of 25 mm s −1 is achieved in water flow sensing. The sensors can passively sense underwater objects by transducing the pressure variations generated underwater by the movement of objects. The experimental results demonstrate the array’s ability to detect the velocity of underwater objects towed past by with high accuracy, and an average error of only 2.5%. (paper)

  20. X-ray imaging for studying behavior of liquids at high pressures and high temperatures using Paris-Edinburgh press

    International Nuclear Information System (INIS)

    Kono, Yoshio; Kenney-Benson, Curtis; Park, Changyong; Shen, Guoyin; Shibazaki, Yuki; Wang, Yanbin

    2015-01-01

    Several X-ray techniques for studying structure, elastic properties, viscosity, and immiscibility of liquids at high pressures have been integrated using a Paris-Edinburgh press at the 16-BM-B beamline of the Advanced Photon Source. Here, we report the development of X-ray imaging techniques suitable for studying behavior of liquids at high pressures and high temperatures. White X-ray radiography allows for imaging phase separation and immiscibility of melts at high pressures, identified not only by density contrast but also by phase contrast imaging in particular for low density contrast liquids such as silicate and carbonate melts. In addition, ultrafast X-ray imaging, at frame rates up to ∼10 5 frames/second (fps) in air and up to ∼10 4 fps in Paris-Edinburgh press, enables us to investigate dynamics of liquids at high pressures. Very low viscosities of melts similar to that of water can be reliably measured. These high-pressure X-ray imaging techniques provide useful tools for understanding behavior of liquids or melts at high pressures and high temperatures

  1. X-ray imaging for studying behavior of liquids at high pressures and high temperatures using Paris-Edinburgh press

    Energy Technology Data Exchange (ETDEWEB)

    Kono, Yoshio; Kenney-Benson, Curtis; Park, Changyong; Shen, Guoyin [HPCAT, Geophysical Laboratory, Carnegie Institution of Washington, 9700 S. Cass Ave., Argonne, Illinois 60439 (United States); Shibazaki, Yuki [Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Aramaki aza Aoba 6-3, Aoba-ku, Sendai 980-8578 (Japan); Wang, Yanbin [GeoSoilEnviroCARS, Center for Advanced Radiation Sources, The University of Chicago, 5640 S. Ellis Avenue, Chicago, Illinois 60637 (United States)

    2015-07-15

    Several X-ray techniques for studying structure, elastic properties, viscosity, and immiscibility of liquids at high pressures have been integrated using a Paris-Edinburgh press at the 16-BM-B beamline of the Advanced Photon Source. Here, we report the development of X-ray imaging techniques suitable for studying behavior of liquids at high pressures and high temperatures. White X-ray radiography allows for imaging phase separation and immiscibility of melts at high pressures, identified not only by density contrast but also by phase contrast imaging in particular for low density contrast liquids such as silicate and carbonate melts. In addition, ultrafast X-ray imaging, at frame rates up to ∼10{sup 5} frames/second (fps) in air and up to ∼10{sup 4} fps in Paris-Edinburgh press, enables us to investigate dynamics of liquids at high pressures. Very low viscosities of melts similar to that of water can be reliably measured. These high-pressure X-ray imaging techniques provide useful tools for understanding behavior of liquids or melts at high pressures and high temperatures.

  2. Determination of benzoylurea insecticides in food by pressurized liquid extraction and LC-MS.

    Science.gov (United States)

    Brutti, Monia; Blasco, Cristina; Picó, Yolanda

    2010-01-01

    A method based on pressurized liquid extraction and LC-MS/MS has been developed for determining nine benzoylureas (BUs) in fruit, vegetable, cereals, and animal products. Samples (5 g) were homogenized with diatomaceous earth and extracted in a 22 mL cell with 22 mL of ethyl acetate at 80 degrees C and 1500 psi. After solvent concentration and exchange to methanol, BUs were analyzed by LC-MS/MS using an IT mass analyzer, which achieved several transitions of precursor ions that increase selectivity providing identification. LOQs were between 0.002 and 0.01 mg/kg, which are equal or lower than maximum residue limits established by the Codex Alimentarius. Excellent linearity was achieved over a range of concentrations from 0.01 to 1 mg/kg with correlation coefficients 0.995-0.999 (n=7). Validation of the total method was performed by analyzing in quintuplicate seven different commodities (milk, eggs, meat, rice, lettuce, avocado, and lemon) at three concentration levels (0.01, 0.1, and 1 mg/kg). The recoveries ranged from 58 to 97% and the RSDs from 5 to 19% depending on the compound and the commodity. The combination of pressurized liquid extraction with LC-MS/MS provides a sensitive and selective method for the determination of BUs in food.

  3. A variational model of disjoining pressure: Liquid film on a nonplanar surface

    Energy Technology Data Exchange (ETDEWEB)

    Silin, D.; Virnovsky, G.

    2009-06-01

    Variational methods have been successfully used in modelling thin liquid films in numerous theoretical studies of wettability. In this paper, the variational model of the disjoining pressure is extended to the general case of a two-dimensional solid surface. The Helmgoltz free energy functional depends both on the disjoining pressure isotherm and the shape of the solid surface. The augmented Young-Laplace equation (AYLE) is a nonlinear second-order partial differential equation. A number of solutions describing wetting films on spherical grains have been obtained. In the case of cylindrical films, the phase portrait technique describes the entire variety of mathematically feasible solutions. It turns out that a periodic solution, which would describe wave-like wetting films, does not satisfy the Jacobi's condition of the classical calculus of variations. Therefore, such a solution is nonphysical. The roughness of the solid surface significantly affects liquid film stability. AYLE solutions suggest that film rupture is more likely at a location where the pore-wall surface is most exposed into the pore space and the curvature is positive.

  4. Generalized method for calculation and prediction of vapour-liquid equilibria at high pressures

    Energy Technology Data Exchange (ETDEWEB)

    Drahos, J; Wichterle, I; Hala, E

    1978-02-01

    Following the approaches of K.C. Chao and J.D. Seader (see Gas Abstr. 18,24 (1962) Jan.) and B.I. Lee, J.H. Erbar, and W.C. Edmister (see Gas Abst. 29, 73-0331), the Czechoslovak Academy of Sciences developed a generalized method for prediction of vapor-liquid equilibria in hydrocarbon mixtures containing some nonhydrocarbon gases at high pressures. The method proposed is based on three equations: (1) a generalized equation of state for vapor-phase calculations; (2) a generalized expression for the pure-liquid fugacity coefficient; and (3) an activity coefficient expression based on a surface modification of the regular solution model. The equations used contain only one partially generalized binary parameter, which was evaluated from experimental K-value data. Researchers tested the proposed method by computing K-values and pressures in binary and multicomponent systems consisting of 13 hydrocarbons and 3 nonhydrocarbon gases. The results show that the method is applicable over a wide range of conditions with a degree of accuracy comparable with that of more complicated methods.

  5. Direct measurements of liquid film roughness for the prediction of annular flow pressure drop

    International Nuclear Information System (INIS)

    Ashwood, Andrea C.; Schubring, DuWayne; Shedd, Timothy A.

    2009-01-01

    A vertical two-phase (air-water) test section has been constructed to allow for detailed visualization of flow phenomena in the annular regime. The total internal reflection (TIR) technique for film thickness estimation, originally developed by Shedd and Newell (1998), has been adapted for use in this test section. This technique uses the pattern of diffuse light reflected from the gas-liquid interface to estimate the base film thickness, i.e., the thickness between large liquid waves. Measurement of base film thickness separately from the average film thickness, which couples base film and wave behavior, allows for consideration of separate effects from each of the two zones. A modified Hurlburt-Newell (2000) correlation that separates the flow into these two zones has been generated. Data regarding the relationship between average base film thickness and wave height, along with verification of the base film thickness measured from the TIR technique, were provided by planar laser-induced fluorescence (PLIF). For the present vertical air-water up flows with liquid superficial velocities ranging from 4 to 34 cm s -1 and gas superficial velocities from 35 to 85 m s -1 , the modified Hurlburt-Newell correlation predicts pressure loss to within 10%. (author)

  6. Direct measurements of liquid film roughness for the prediction of annular flow pressure drop

    Energy Technology Data Exchange (ETDEWEB)

    Ashwood, Andrea C; Schubring, DuWayne; Shedd, Timothy A. [University of Wisconsin, Madison, WI (United States)], e-mail: cashwood@wisc.edu, e-mail: dlschubring@wisc.edu, e-mail: shedd@engr.wisc.edu

    2009-07-01

    A vertical two-phase (air-water) test section has been constructed to allow for detailed visualization of flow phenomena in the annular regime. The total internal reflection (TIR) technique for film thickness estimation, originally developed by Shedd and Newell (1998), has been adapted for use in this test section. This technique uses the pattern of diffuse light reflected from the gas-liquid interface to estimate the base film thickness, i.e., the thickness between large liquid waves. Measurement of base film thickness separately from the average film thickness, which couples base film and wave behavior, allows for consideration of separate effects from each of the two zones. A modified Hurlburt-Newell (2000) correlation that separates the flow into these two zones has been generated. Data regarding the relationship between average base film thickness and wave height, along with verification of the base film thickness measured from the TIR technique, were provided by planar laser-induced fluorescence (PLIF). For the present vertical air-water up flows with liquid superficial velocities ranging from 4 to 34 cm s{sup -1} and gas superficial velocities from 35 to 85 m s{sup -1}, the modified Hurlburt-Newell correlation predicts pressure loss to within 10%. (author)

  7. Water Flow Testing and Unsteady Pressure Analysis of a Two-Bladed Liquid Oxidizer Pump Inducer

    Science.gov (United States)

    Schwarz, Jordan B.; Mulder, Andrew; Zoladz, Thomas

    2011-01-01

    The unsteady fluid dynamic performance of a cavitating two-bladed oxidizer turbopump inducer was characterized through sub-scale water flow testing. While testing a novel inlet duct design that included a cavitation suppression groove, unusual high-frequency pressure oscillations were observed. With potential implications for inducer blade loads, these high-frequency components were analyzed extensively in order to understand their origins and impacts to blade loading. Water flow testing provides a technique to determine pump performance without the costs and hazards associated with handling cryogenic propellants. Water has a similar density and Reynolds number to liquid oxygen. In a 70%-scale water flow test, the inducer-only pump performance was evaluated. Over a range of flow rates, the pump inlet pressure was gradually reduced, causing the flow to cavitate near the pump inducer. A nominal, smooth inducer inlet was tested, followed by an inlet duct with a circumferential groove designed to suppress cavitation. A subsequent 52%-scale water flow test in another facility evaluated the combined inducer-impeller pump performance. With the nominal inlet design, the inducer showed traditional cavitation and surge characteristics. Significant bearing loads were created by large side loads on the inducer during synchronous cavitation. The grooved inlet successfully mitigated these loads by greatly reducing synchronous cavitation, however high-frequency pressure oscillations were observed over a range of frequencies. Analytical signal processing techniques showed these oscillations to be created by a rotating, multi-celled train of pressure pulses, and subsequent CFD analysis suggested that such pulses could be created by the interaction of rotating inducer blades with fluid trapped in a cavitation suppression groove. Despite their relatively low amplitude, these high-frequency pressure oscillations posed a design concern due to their sensitivity to flow conditions and

  8. 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.

  9. 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.

  10. Efficiency droop in nonpolar InGaN quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Schade, Lukas; Schwarz, Ulrich [Fraunhofer Institut fuer Angewandte Festkoerperphysik (IAF), Freiburg im Breisgau (Germany); Institut fuer Mikrosystemtechnik (IMTEK), Universitaet Freiburg, Freiburg im Breisgau (Germany); Wernicke, Tim; Rass, Jens; Ploch, Simon [Institut fuer Festkoerperphysik, Technische Universitaet Berlin (Germany); Weyers, Markus [Ferdinand-Braun-Institut (FBH), Berlin (Germany); Kneissl, Michael [Institut fuer Festkoerperphysik, Technische Universitaet Berlin (Germany); Ferdinand-Braun-Institut (FBH), Berlin (Germany)

    2012-07-01

    InGaN quantum wells (QWs) exhibit a decline of the internal efficiency at high charge carrier excitation. This has been observed for polar as well as for semipolar and nonpolar oriented QWs. Polar stands for the (0001) growth direction with strong piezoelectric fields. Due to the vanishing fields, the orthogonal growth directions (a or m) are called nonpolar, while all directions between are merged as semipolar orientations. In contrast to the polar and many semipolar QWs, nonpolar InGaN QWs provide a special property: optical polarization of the radiative transitions, which is a result of the anisotropic strain within pseudomorphic grown nonpolar QWs. Using this property, the broadened effective emission can be resolved into two fundamental transitions. They are spectrally separated by a defined energy which corresponds to the energy distance of the valence subbands. We studied nonpolar InGaN/InGaN Multi-QWs grown on low defect density GaN substrates with a setup for confocal microscopy. To reach high excitation densities of charge carriers, we use either a combination of an UV laser and highly focusing objectives or an electric pulse generator. The emission is spectrally analysed and compared to established models.

  11. 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

  12. 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

  13. A study on a real-time leak detection method for pressurized liquid refrigerant pipeline based on pressure and flow rate

    International Nuclear Information System (INIS)

    Tian, Shen; Du, Juanli; Shao, Shuangquan; Xu, Hongbo; Tian, Changqing

    2016-01-01

    Highlights: • A real-time leak detection method is developed for ammonia pipeline in cold storage. • A locating algorithm based on pressure difference profile is provided. • This method is validated by R22 and ammonia leak experiments. • The minimum detectable leak ratio is 1% for R22 and 4% for ammonia. • The location estimating errors are −27% ~ 17% for R22 and −27% ~ 27% for ammonia. - Graphical Abstract: - Abstract: Leakage from pressurized liquid ammonia pipeline has been a serious problem in large commercial cold storages because it might release large amount of liquid ammonia and without safety supervision in daily operations. The present paper shows a detection method for a pressurized liquid ammonia pipeline with a leak. The variations of pressure, flow rate and pressure difference profile are studied. A leak indicator (σ), proposed with the one-dimensional steady-state flow model, is used to detect the leak occurrence by comparing it with a threshold value (σ Le ). A locating algorithm based on pressure difference profile along the pipeline is also proposed, which has considered the effect of the static pressure increase at the leak point. Experiments on different leak positions and ratios from liquid R22 and ammonia pipelines are carried out to validate this method. It is found that, with a relatively low false alarm rate (as three percent), the minimum detectable leak ratio reached 1% for the R22 pipeline and 4% for the ammonia pipeline. The locating errors are between −27% ~ 17% for R22 pipeline and −27% ~ 27% for ammonia pipeline.

  14. Ultra high pressure liquid chromatography. Column permeability and changes of the eluent properties.

    Science.gov (United States)

    Gritti, Fabrice; Guiochon, Georges

    2008-04-11

    The behavior of four similar liquid chromatography columns (2.1mm i.d. x 30, 50, 100, and 150 mm, all packed with fine particles, average d(p) approximately 1.7 microm, of bridged ethylsiloxane/silica hybrid-C(18), named BEH-C(18)) was studied in wide ranges of temperature and pressure. The pressure and the temperature dependencies of the viscosity and the density of the eluent (pure acetonitrile) along the columns were also derived, using the column permeabilities and applying the Kozeny-Carman and the heat balance equations. The heat lost through the external surface area of the chromatographic column was directly derived from the wall temperature of the stainless steel tube measured with a precision of +/-0.2 degrees C in still air and +/-0.1 degrees C in the oven compartment. The variations of the density and viscosity of pure acetonitrile as a function of the temperature and pressure was derived from empirical correlations based on precise experimental data acquired between 298 and 373 K and at pressures up to 1.5 kbar. The measurements were made with the Acquity UPLC chromatograph that can deliver a maximum flow rate of 2 mL/min and apply a maximum column inlet pressure of 1038 bar. The average Kozeny-Carman permeability constant of the columns was 144+/-3.5%. The temperature hence the viscosity and the density profiles of the eluent along the column deviate significantly from linear behavior under high-pressure gradients. For a 1000 bar pressure drop, we measured DeltaT=25-30 K, (Deltaeta/eta) approximately 100%, and (Deltarho/rho) approximately 10%. These results show that the radial temperature profiles are never fully developed within 1% for any of the columns, even under still-air conditions. This represents a practical advantage regarding the apparent column efficiency at high flow rates, since the impact of the differential analyte velocity between the column center and the column wall is not maximum. The interpretation of the peak profiles recorded in

  15. Advanced Liquid-Free, Piezoresistive, SOI-Based Pressure Sensors for Measurements in Harsh Environments.

    Science.gov (United States)

    Ngo, Ha-Duong; Mukhopadhyay, Biswaijit; Ehrmann, Oswin; Lang, Klaus-Dieter

    2015-08-18

    In this paper we present and discuss two innovative liquid-free SOI sensors for pressure measurements in harsh environments. The sensors are capable of measuring pressures at high temperatures. In both concepts media separation is realized using a steel membrane. The two concepts represent two different strategies for packaging of devices for use in harsh environments and at high temperatures. The first one is a "one-sensor-one-packaging_technology" concept. The second one uses a standard flip-chip bonding technique. The first sensor is a "floating-concept", capable of measuring pressures at temperatures up to 400 °C (constant load) with an accuracy of 0.25% Full Scale Output (FSO). A push rod (mounted onto the steel membrane) transfers the applied pressure directly to the center-boss membrane of the SOI-chip, which is placed on a ceramic carrier. The chip membrane is realized by Deep Reactive Ion Etching (DRIE or Bosch Process). A novel propertied chip housing employing a sliding sensor chip that is fixed during packaging by mechanical preloading via the push rod is used, thereby avoiding chip movement, and ensuring optimal push rod load transmission. The second sensor can be used up to 350 °C. The SOI chips consists of a beam with an integrated centre-boss with was realized using KOH structuring and DRIE. The SOI chip is not "floating" but bonded by using flip-chip technology. The fabricated SOI sensor chip has a bridge resistance of 3250 Ω. The realized sensor chip has a sensitivity of 18 mV/µm measured using a bridge current of 1 mA.

  16. Advanced Liquid-Free, Piezoresistive, SOI-Based Pressure Sensors for Measurements in Harsh Environments

    Directory of Open Access Journals (Sweden)

    Ha-Duong Ngo

    2015-08-01

    Full Text Available In this paper we present and discuss two innovative liquid-free SOI sensors for pressure measurements in harsh environments. The sensors are capable of measuring pressures at high temperatures. In both concepts media separation is realized using a steel membrane. The two concepts represent two different strategies for packaging of devices for use in harsh environments and at high temperatures. The first one is a “one-sensor-one-packaging_technology” concept. The second one uses a standard flip-chip bonding technique. The first sensor is a “floating-concept”, capable of measuring pressures at temperatures up to 400 °C (constant load with an accuracy of 0.25% Full Scale Output (FSO. A push rod (mounted onto the steel membrane transfers the applied pressure directly to the center-boss membrane of the SOI-chip, which is placed on a ceramic carrier. The chip membrane is realized by Deep Reactive Ion Etching (DRIE or Bosch Process. A novel propertied chip housing employing a sliding sensor chip that is fixed during packaging by mechanical preloading via the push rod is used, thereby avoiding chip movement, and ensuring optimal push rod load transmission. The second sensor can be used up to 350 °C. The SOI chips consists of a beam with an integrated centre-boss with was realized using KOH structuring and DRIE. The SOI chip is not “floating” but bonded by using flip-chip technology. The fabricated SOI sensor chip has a bridge resistance of 3250 Ω. The realized sensor chip has a sensitivity of 18 mV/µm measured using a bridge current of 1 mA.

  17. Microcolumn high pressure liquid chromatography with a glass-frit nebulizer interface for plasma emission detection

    International Nuclear Information System (INIS)

    Ibrahim, M.; Nisamaneepong, W.; Caruso, J.

    1985-01-01

    Microcolumn high pressure liquid chromatography (micro-HPLC) is rapidly gaining recognition as a practical separation tool for organometallic compounds. The use of the inductively coupled plasma (ICP) as a detector for micro-HPLC is studied. Several miniaturized glass-frit nebulizers are investigated as interfaces between the output of the microbore column and the ICP torch. Their performance with aqueous and methanolic solutions is evaluated by direct nebulization and flow injection analysis. The most efficient of these nebulizers is used in the micro-HPLC/ICP study of some Cd, Pb, and Zn organometallic compounds. Detection limits of 1.92 ng of Pb for tetramethyllead and 5.01 ng of Pb for tetraethyllead are obtained and compared with regular HPLC/ICP of these same compounds. Approximately equivalent detection limits were obtained when using a microwave induced plasma as an alternate plasma source

  18. Competitive excitation and osmotic-pressure-mediated control of lasing modes in cholesteric liquid crystal microshells

    Science.gov (United States)

    Lin, Ya-Li; Gong, Ling-Li; Che, Kai-Jun; Li, Sen-Sen; Chu, Cheng-Xu; Cai, Zhi-Ping; Yang, Chaoyong James; Chen, Lu-Jian

    2017-05-01

    We examined the end-pumped lasing behaviors of dye doped cholesteric liquid crystal (DDCLC) microshells which were fabricated by glass capillary microfluidics. Several kinds of mode resonances, including distributed feedback, Fabry-Pérot (FP), and whispering gallery (WG) modes, can be robustly constructed in each individual DDCLC microshell by varying the beam diameter, namely, tuning the DDCLC gain area. The FP and WG modes were further confirmed experimentally, and the corresponding lasing mechanisms are clearly revealed from the unique material characteristics of DDCLC and the geometrical structure of the microshell. Additionally, we demonstrated that the osmotic pressure can be used to shrink/expand the microshell, productively tuning the excitation of lasing modes in a controlled manner. We wish our findings can provide a new insight into the design of DDCLC microlasers with tunable optical properties.

  19. Pressurized liquid extraction of anthocyanins and biflavonoids from Schinus terebinthifolius Raddi: A multivariate optimization.

    Science.gov (United States)

    Feuereisen, Michelle M; Gamero Barraza, Mariana; Zimmermann, Benno F; Schieber, Andreas; Schulze-Kaysers, Nadine

    2017-01-01

    Response surface methodology was employed to investigate the effects of pressurized liquid extraction (PLE) parameters on the recovery of phenolic compounds (anthocyanins, biflavonoids) from Brazilian pepper (Schinus terebinthifolius Raddi) fruits. The effects of temperature, static time, and ethanol as well as acid concentration on the polyphenol yield were described well by quadratic models (p75°C), an artifact occurred and was tentatively identified as a diastereomer of I3',II8-binaringenin. Multivariate optimization led to high yields of phenolic compounds from the exocarp/drupes at 100/75°C, 10/10min, 54.5/54.2% ethanol, and 5/0.03% acetic acid. This study demonstrates that PLE is well suited for the extraction of phenolic compounds from S. terebinthifolius and can efficiently be optimized by response surface methodology. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Antioxidant White Grape Seed Phenolics: Pressurized Liquid Extracts from Different Varieties

    Directory of Open Access Journals (Sweden)

    Carmen Garcia-Jares

    2015-11-01

    Full Text Available Grape seeds represent a high percentage (20% to 26% of the grape marc obtained as a byproduct from white winemaking and keep a vast proportion of grape polyphenols. In this study, seeds obtained from 11 monovarietal white grape marcs cultivated in Northwestern Spain have been analyzed in order to characterize their polyphenolic content and antioxidant activity. Seeds of native (Albariño, Caiño, Godello, Loureiro, Torrontés, and Treixadura and non-native (Chardonnay, Gewurtzträminer, Pinot blanc, Pinot gris, and Riesling grape varieties have been considered. Low weight phenolics have been extracted by means of pressurized liquid extraction (PLE and further analyzed by LC-MS/MS. The results showed that PLE extracts, whatever the grape variety of origin, contained large amounts of polyphenols and high antioxidant activity. Differences in the varietal polyphenolic profiles were found, so a selective exploitation of seeds might be possible.

  1. Antioxidant White Grape Seed Phenolics: Pressurized Liquid Extracts from Different Varieties

    Science.gov (United States)

    Garcia-Jares, Carmen; Vazquez, Alberto; Lamas, Juan P.; Pajaro, Marta; Alvarez-Casas, Marta; Lores, Marta

    2015-01-01

    Grape seeds represent a high percentage (20% to 26%) of the grape marc obtained as a byproduct from white winemaking and keep a vast proportion of grape polyphenols. In this study, seeds obtained from 11 monovarietal white grape marcs cultivated in Northwestern Spain have been analyzed in order to characterize their polyphenolic content and antioxidant activity. Seeds of native (Albariño, Caiño, Godello, Loureiro, Torrontés, and Treixadura) and non-native (Chardonnay, Gewurtzträminer, Pinot blanc, Pinot gris, and Riesling) grape varieties have been considered. Low weight phenolics have been extracted by means of pressurized liquid extraction (PLE) and further analyzed by LC-MS/MS. The results showed that PLE extracts, whatever the grape variety of origin, contained large amounts of polyphenols and high antioxidant activity. Differences in the varietal polyphenolic profiles were found, so a selective exploitation of seeds might be possible. PMID:26783956

  2. Deformation and degradation of polymers in ultra-high-pressure liquid chromatography.

    Science.gov (United States)

    Uliyanchenko, Elena; van der Wal, Sjoerd; Schoenmakers, Peter J

    2011-09-28

    Ultra-high-pressure liquid chromatography (UHPLC) using columns packed with sub-2 μm particles has great potential for separations of many types of complex samples, including polymers. However, the application of UHPLC for the analysis of polymers meets some fundamental obstacles. Small particles and narrow bore tubing in combination with high pressures generate significant shear and extensional forces in UHPLC systems, which may affect polymer chains. At high stress conditions flexible macromolecules may become extended and eventually the chemical bonds in the molecules can break. Deformation and degradation of macromolecules will affect the peak retention and the peak shape in the chromatogram, which may cause errors in the obtained results (e.g. the calculated molecular-weight distributions). In the present work we explored the limitations of UHPLC for the analysis of polymers. Degradation and deformation of macromolecules were studied by collecting and re-injecting polymer peaks and by off-line two-dimensional liquid chromatography. Polystyrene standards with molecular weight of 4 MDa and larger were found to degrade at UHPLC conditions. However, for most polymers degradation could be avoided by using low linear velocities. No degradation of 3-MDa PS (and smaller) was observed at linear velocities up to 7 mm/s. The column frits were implicated as the main sources of polymer degradation. The extent of degradation was found to depend on the type of the column and on the column history. At high flow rates degradation was observed without a column being installed. We demonstrated that polymer deformation preceded degradation. Stretched polymers eluted from the column in slalom chromatography mode (elution order opposite to that in SEC or HDC). Under certain conditions we observed co-elution of large and small PS molecules though a convolution of slalom chromatography and hydrodynamic chromatography. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Positive end-expiratory pressure improves gas exchange and pulmonary mechanics during partial liquid ventilation.

    Science.gov (United States)

    Kirmse, M; Fujino, Y; Hess, D; Kacmarek, R M

    1998-11-01

    Partial liquid ventilation (PLV) with perflubron (PFB) has been proposed as an adjunct to the current therapies for the acute respiratory distress syndrome (ARDS). Because PFB has been also referred to as "liquid PEEP," distributing to the most gravity-dependent regions of the lung, less attention has been paid to the amount of applied positive end-expiratory pressure (PEEP). We hypothesized that higher PEEP levels than currently applied are needed to optimize gas exchange, and that the lower inflection point (LIP) of the pressure-volume curve could be used to estimate the amount of PEEP needed when the lung is filled with PFB. Lung injury was induced in 23 sheep by repeated lung lavage with warmed saline until the PaO2/FIO2 ratio fell below 150. Five sheep were used to investigate the change of the LIP when the lung was filled with PFB in increments of 5 ml/kg/body weight to a total of 30 ml/kg/body weight. To evaluate the impact of PEEP set at LIP +1 cm H2O we randomized an additional 15 sheep to three groups with different doses (7.5 ml, 15 ml, 30 ml/kg/body weight) of PFB. In random order a PEEP of 5 cm H2O or PEEP at LIP +1 cm H2O was applied. The LIP decreased with incremental filling of PFB to a minimum at 10 ml (p PFB shifts the LIP to the left, and that setting PEEP at LIP +1 cm H2O improves gas exchange at moderate to high doses of PFB.

  4. Comparison of various droplet breakup models in gas-liquid flows in high-pressure environments

    International Nuclear Information System (INIS)

    Khaleghi, H.; Ganji, D. D.; Omidvar, A.

    2008-01-01

    Droplet breakup affects spray penetration and evaporation, and plays a critical role in engine efficiency. The purpose of this research was to examine the rate of penetration and evaporation of droplets in a combustion chamber, and the efficiency of the engine when liquid jet is injected into the compressed gas chamber in an axi-symmetrical fashion leading to a turbulent and unsteady flow. As a result of interaction with the highly compressed air in the chamber, the liquid jet breaks up and forms minute droplets. These particles will in turn breakup because of aerodynamic forces, producing even smaller droplets. A number of models are available for analyzing the breakup of droplets; however, each model is typically reliable only over a limited parameter range. In this research three well-known models are applied for droplet breakup modeling and their results are compared. To obtain the details of the flow field, the Eulerian gas phase mass, momentum and energy conservation equations, as well as equations governing the transport of turbulence and fuel vapor mass fraction are solved together with equations of trajectory, momentum, mass and energy conservation for liquid droplets in Lagrangian form. The numerical solution is performed using the finite volume method and EPISO (Engine-PISO) algorithm. The results obtained from the models show that the breakup process in a high pressure environment significantly affects the penetration and evaporation rates of the spray, and the droplet size is determined by the balance between breakup and coalescence processes. It is also shown that the details of atomization in the nozzle do not significantly influence the ultimate size of droplets. It should be mentioned that droplet collision modeling has been taken into account in the computer code and is activated wherever necessary

  5. Experimental Investigation of Liquid-Level Measuring Accuracy in a Low Pressure Environment

    International Nuclear Information System (INIS)

    Adamson, D.J.

    1996-10-01

    Dip Tubes which are used for determining liquid level in many processes at SRS will be used to measure the liquid level of the Am/Cm solution in the Feed Tank at the MPPF. The Feed Tank operates under a vacuum, therefore the Dip Tubes will operate under a vacuum. Uncertainty in how accurate the Dip Tubes would perform in a vacuum environment led to testing. The Am/Cm Melter Liquid-Feed Tank measurement test was mocked-up per Figure 1. The Feed Tank was designed to simulate actual conditions in which the Dip Tubes would measure the differential pressure. The Feed Tank was made of Stainless Steel with a Lexan window to view inside the tank during testing. The Feed Tank was built per Drawing SRT-ETF-DD-96008, Revision A. The accuracy of the Dip Tubes was checked first by filling the Feed Tank at a flow rate of 3.5 L/min and venting it to the atmosphere. Figure 2 shows that the Dip Tubes were responsive and accurate when compared to the data from the measuring scale on the view window. Then tests were conducted with 23y Hg vacuum inside the tank and water flow rates of 3.9 L/min, 1.8 L/min, and 0.7 L/min being fed to the tank. The data from each test are depicted in Figure 3, Figure 4, and Figure 5, respectively. The Dip Tubes responded accurately for the three test with a maximum error range of +0.31y to -0.19y when compared to the measuring scale located next to the view window on the Feed Tank

  6. Cellulose-Supported Ionic Liquids for Low-Cost Pressure Swing CO{sub 2} Capture

    Energy Technology Data Exchange (ETDEWEB)

    Reed, Daniel G.; Dowson, George R. M.; Styring, Peter, E-mail: p.styring@sheffield.ac.uk [UK Centre for Carbon Dioxide Utilisation, Department of Chemical and Biological Engineering, The University of Sheffield, Sheffield (United Kingdom)

    2017-07-07

    Reducing the cost of capturing CO{sub 2} from point source emitters is a major challenge facing carbon capture, utilization, and storage. While solid ionic liquids (SoILs) have been shown to allow selective and rapid CO{sub 2} capture by pressure swing separation of flue gases, expectations of their high cost hinders their potential application. Cellulose is found to be a reliable, cheap, and sustainable support for a range of SoILs, reducing the total sorbent cost by improving the efficiency of the ionic liquid (IL) through increased ionic surface area that results from coating. It was also found that cellulose support imparts surface characteristics, which increased total sorbent uptake. Combined, these effects allowed a fourfold to eightfold improvement in uptake per gram of IL for SoILs that have previously shown high uptake and a 9- to 39-fold improvement for those with previously poor uptake. This offers the potential to drastically reduce the amount of IL required to separate a given gas volume. Furthermore, the fast kinetics are retained, with adsorb–desorb cycles taking place over a matter of seconds. This means that rapid cycling can be achieved, which results in high cumulative separation capacity relative to a conventional temperature swing process. The supported materials show an optimum at 75% cellulose:25% IL as a result of even coating of the cellulose surface. The projected reduction in plant size and operational costs represents a potentially ground-breaking step forward in carbon dioxide capture technologies.

  7. Optimizing pressurized liquid extraction of microbial lipids using the response surface method.

    Science.gov (United States)

    Cescut, J; Severac, E; Molina-Jouve, C; Uribelarrea, J-L

    2011-01-21

    Response surface methodology (RSM) was used for the determination of optimum extraction parameters to reach maximum lipid extraction yield with yeast. Total lipids were extracted from oleaginous yeast (Rhodotorula glutinis) using pressurized liquid extraction (PLE). The effects of extraction parameters on lipid extraction yield were studied by employing a second-order central composite design. The optimal condition was obtained as three cycles of 15 min at 100°C with a ratio of 144 g of hydromatrix per 100 g of dry cell weight. Different analysis methods were used to compare the optimized PLE method with two conventional methods (Soxhlet and modification of Bligh and Dyer methods) under efficiency, selectivity and reproducibility criteria thanks to gravimetric analysis, GC with flame ionization detector, High Performance Liquid Chromatography linked to Evaporative Light Scattering Detector (HPLC-ELSD) and thin-layer chromatographic analysis. For each sample, the lipid extraction yield with optimized PLE was higher than those obtained with referenced methods (Soxhlet and Bligh and Dyer methods with, respectively, a recovery of 78% and 85% compared to PLE method). Moreover, the use of PLE led to major advantages such as an analysis time reduction by a factor of 10 and solvent quantity reduction by 70%, compared with traditional extraction methods. Copyright © 2010 Elsevier B.V. All rights reserved.

  8. Determination of sedative hypnotics in sewage sludge by pressurized liquid extraction with high-performance liquid chromatography and tandem mass spectrometry.

    Science.gov (United States)

    Arbeláez, Paula; Granados, Judith; Borrull, Francesc; Marcé, Rosa Maria; Pocurull, Eva

    2014-12-01

    This paper describes a method for the determination of eight sedative hypnotics (benzodiazepines and barbiturates) in sewage sludge using pressurized liquid extraction and liquid chromatography with tandem mass spectrometry. Pressurized liquid extraction operating conditions were optimized and maximum recoveries were reached using methanol under the following operational conditions: 100ºC, 1500 psi, extraction time of 5 min, one extraction cycle, flush volume of 60% and purge time of 120 s. Pressurized liquid extraction recoveries were higher than 88% for all the compounds except for carbamazepine (55%). The repeatability and reproducibility between days, expressed as relative standard deviation (n = 5), were lower than 6 and 10%, respectively. The detection limits for all compounds were lower than 12.5 μg/kg of dry weight. The method was applied to determine benzodiazepines and barbiturates in sewage sludge from urban sewage treatment plants, and carbamazepine showed the highest concentration (7.9-18.9 μg/kg dry weight). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Development of a general model for determination of thermal conductivity of liquid chemical compounds at atmospheric pressure

    DEFF Research Database (Denmark)

    Gharagheizi, Farhad; Ilani‐Kashkouli, Poorandokht; Sattari, Mehdi

    2013-01-01

    In this communication, a general model for representation/presentation of the liquid thermal conductivity of chemical compounds (mostly organic) at 1 atm pressure for temperatures below normal boiling point and at saturation pressure for temperatures above the normal boiling point is developed...... using the Gene Expression Programming algorithm. Approximately 19,000 liquid thermal conductivity data at different temperatures related to 1636 chemical compounds collected from the DIPPR 801 database are used to obtain the model as well as to assess its predictive capability. The parameters...

  10. Liquid sampling-atmospheric pressure glow discharge as a secondary excitation source: Assessment of plasma characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Manard, Benjamin T. [Department of Chemistry, Clemson University, Clemson, SC 29634 (United States); Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Gonzalez, Jhanis J. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Sarkar, Arnab [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Fuel Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Dong, Meirong; Chirinos, Jose; Mao, Xianglei; Russo, Richard E. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Marcus, R. Kenneth [Department of Chemistry, Clemson University, Clemson, SC 29634 (United States)

    2014-04-01

    The liquid sampling-atmospheric pressure glow discharge (LS-APGD) has been assessed as a secondary excitation source with a parametric evaluation regarding carrier gas flow rate, applied current, and electrode distance. With this parametric evaluation, plasma optical emission was monitored in order to obtain a fundamental understanding with regards to rotational temperature (T{sub rot}), excitation temperature (T{sub exc}), electron number density (n{sub e}), and plasma robustness. Incentive for these studies is not only for a greater overall fundamental knowledge of the APGD, but also in instrumenting a secondary excitation/ionization source following laser ablation (LA). Rotational temperatures were determined through experimentally fitting of the N{sub 2} and OH molecular emission bands while atomic excitation temperatures were calculated using a Boltzmann distribution of He and Mg atomic lines. The rotational and excitation temperatures were determined to be ∼ 1000 K and ∼ 2700 K respectively. Electron number density was calculated to be on the order of ∼ 3 × 10{sup 15} cm{sup −3} utilizing Stark broadening effects of the Hα line of the Balmer series and a He I transition. In addition, those diagnostics were performed introducing magnesium (by solution feed and laser ablation) into the plasma in order to determine any perturbation under heavy matrix sampling. The so-called plasma robustness factor, derived by monitoring Mg II/Mg I emission ratios, is also employed as a reflection of potential perturbations in microplasma energetics across the various operation conditions and sample loadings. While truly a miniaturized source (< 1 mm{sup 3} volume), the LS-APGD is shown to be quite robust with plasma characteristics and temperatures being unaffected upon introduction of metal species, whether by liquid or laser ablation sample introduction. - Highlights: • Liquid sampling-atmospheric pressure glow discharge (LS-APGD) • LS-APGD as a secondary

  11. Liquid sampling-atmospheric pressure glow discharge as a secondary excitation source: Assessment of plasma characteristics

    International Nuclear Information System (INIS)

    Manard, Benjamin T.; Gonzalez, Jhanis J.; Sarkar, Arnab; Dong, Meirong; Chirinos, Jose; Mao, Xianglei; Russo, Richard E.; Marcus, R. Kenneth

    2014-01-01

    The liquid sampling-atmospheric pressure glow discharge (LS-APGD) has been assessed as a secondary excitation source with a parametric evaluation regarding carrier gas flow rate, applied current, and electrode distance. With this parametric evaluation, plasma optical emission was monitored in order to obtain a fundamental understanding with regards to rotational temperature (T rot ), excitation temperature (T exc ), electron number density (n e ), and plasma robustness. Incentive for these studies is not only for a greater overall fundamental knowledge of the APGD, but also in instrumenting a secondary excitation/ionization source following laser ablation (LA). Rotational temperatures were determined through experimentally fitting of the N 2 and OH molecular emission bands while atomic excitation temperatures were calculated using a Boltzmann distribution of He and Mg atomic lines. The rotational and excitation temperatures were determined to be ∼ 1000 K and ∼ 2700 K respectively. Electron number density was calculated to be on the order of ∼ 3 × 10 15 cm −3 utilizing Stark broadening effects of the Hα line of the Balmer series and a He I transition. In addition, those diagnostics were performed introducing magnesium (by solution feed and laser ablation) into the plasma in order to determine any perturbation under heavy matrix sampling. The so-called plasma robustness factor, derived by monitoring Mg II/Mg I emission ratios, is also employed as a reflection of potential perturbations in microplasma energetics across the various operation conditions and sample loadings. While truly a miniaturized source ( 3 volume), the LS-APGD is shown to be quite robust with plasma characteristics and temperatures being unaffected upon introduction of metal species, whether by liquid or laser ablation sample introduction. - Highlights: • Liquid sampling-atmospheric pressure glow discharge (LS-APGD) • LS-APGD as a secondary excitation source for laser-ablated (LA

  12. New calibration methodology for calorimetric determination of isobaric thermal expansivity of liquids as a function of temperature and pressure

    Energy Technology Data Exchange (ETDEWEB)

    Navia, Paloma; Troncoso, Jacobo [Departamento de Fisica Aplicada, Facultad de Ciencias de Ourense, Campus As Lagoas, 32004 Ourense (Spain); Romani, Luis [Departamento de Fisica Aplicada, Facultad de Ciencias de Ourense, Campus As Lagoas, 32004 Ourense (Spain)], E-mail: romani@uvigo.es

    2008-11-15

    A new method for determining isobaric thermal expansivity of liquids as a function of temperature and pressure through calorimetric measurements against pressure is described. It is based on a previously reported measurement technique, but due to the different kind of calorimeter and experimental set up, a new calibration procedure was developed. Two isobaric thermal expansivity standards are needed; in this work, with a view on the quality of the available literature data, hexane and water are chosen. The measurements were carried out in the temperature and pressure intervals (278.15 to 348.15) K and (0.5 to 55) MPa for a set of liquids, and experimental values are compared with the available literature data in order to evaluate the precision of the experimental procedure. The analysis of the results reveals that the proposed methodology is highly accurate for isobaric thermal expansivity determination, and it allows obtaining a precise characterisation of the temperature and pressure dependence of this thermodynamic coefficient.

  13. New calibration methodology for calorimetric determination of isobaric thermal expansivity of liquids as a function of temperature and pressure

    International Nuclear Information System (INIS)

    Navia, Paloma; Troncoso, Jacobo; Romani, Luis

    2008-01-01

    A new method for determining isobaric thermal expansivity of liquids as a function of temperature and pressure through calorimetric measurements against pressure is described. It is based on a previously reported measurement technique, but due to the different kind of calorimeter and experimental set up, a new calibration procedure was developed. Two isobaric thermal expansivity standards are needed; in this work, with a view on the quality of the available literature data, hexane and water are chosen. The measurements were carried out in the temperature and pressure intervals (278.15 to 348.15) K and (0.5 to 55) MPa for a set of liquids, and experimental values are compared with the available literature data in order to evaluate the precision of the experimental procedure. The analysis of the results reveals that the proposed methodology is highly accurate for isobaric thermal expansivity determination, and it allows obtaining a precise characterisation of the temperature and pressure dependence of this thermodynamic coefficient

  14. Computer-aided thermohydraulic design of TEMA type E shell and tube heat exchangers for use in low pressure, liquid-to-liquid, single phase applications

    Science.gov (United States)

    Kolar, N. J.

    1985-04-01

    Classification, nomenclature, utilization and cost estimating of shell and tube heat exchangers are presented along with an historical overview of various methods currently employed in their design. A procedure for providing preliminary estimates of shell and tube heat exchanger design is developed in detail. The author formulates a computer program which employs this sizing algorithm for low pressure liquid-to-liquid heat exchanger applications. Additionally, problems encountered in the design and manufacture of shell and tube heat exchangers are described along with present methods of solution for each.

  15. Liquid chromatography/mass spectrometric determination of patulin in apple juice using atmospheric pressure photoionization.

    Science.gov (United States)

    Takino, Masahiko; Daishima, Shigeki; Nakahara, Taketoshi

    2003-01-01

    This paper describes a comparison between atmospheric pressure chemical ionization (APCI) and the recently introduced atmospheric pressure photoionization (APPI) technique for the liquid chromatography/mass spectrometric (LC/MS) determination of patulin in clear apple juice. A column switching technique for on-line extraction of clear apple juice was developed. The parameters investigated for the optimization of APPI were the ion source parameters fragmentor voltage, capillary voltage, and vaporizer temperature, and also mobile phase composition and flow rate. Furthermore, chemical noise and signal suppression of analyte signals due to sample matrix interference were investigated for both APCI and APPI. The results indicated that APPI provides lower chemical noise and signal suppression in comparison with APCI. The linear range for patulin in apple juice (correlation coefficient >0.999) was 0.2-100 ng mL(-1). Mean recoveries of patulin in three apple juices ranged from 94.5 to 103.2%, and the limit of detection (S/N = 3), repeatability and reproducibility were 1.03-1.50 ng mL(-1), 3.9-5.1% and 7.3-8.2%, respectively. The total analysis time was 10.0 min. Copyright 2003 John Wiley & Sons, Ltd.

  16. Acceptance test procedure for the ultra high pressure bore head for use in the self-installing liquid observation well

    International Nuclear Information System (INIS)

    Hertelendy, N.A.

    1995-01-01

    In order to monitor waste stored in single-shell tanks, liquid observation wells (LOWs) are installed to permit periodic insertion of instrumentation probes to evaluate the waste cross sections. An ultra high pressure water bore head, developed for installing instrument trees, was adapted for use with the LOWs. The modification facilitates the removal of the high pressure water feed system after installation. This document describes a series of tests that ensures that the design meets all the functional requirements

  17. Liquids and liquid mixtures

    CERN Document Server

    Rowlinson, J S; Baldwin, J E; Buckingham, A D; Danishefsky, S

    2013-01-01

    Liquids and Liquid Mixtures, Third Edition explores the equilibrium properties of liquids and liquid mixtures and relates them to the properties of the constituent molecules using the methods of statistical thermodynamics. Topics covered include the critical state, fluid mixtures at high pressures, and the statistical thermodynamics of fluids and mixtures. This book consists of eight chapters and begins with an overview of the liquid state and the thermodynamic properties of liquids and liquid mixtures, including vapor pressure and heat capacities. The discussion then turns to the thermodynami

  18. Column properties and flow profiles of a flat, wide column for high-pressure liquid chromatography.

    Science.gov (United States)

    Mriziq, Khaled S; Guiochon, Georges

    2008-04-11

    The design and the construction of a pressurized, flat, wide column for high-performance liquid chromatography (HPLC) are described. This apparatus, which is derived from instruments that implement over-pressured thin layer chromatography, can carry out only uni-dimensional chromatographic separations. However, it is intended to be the first step in the development of more powerful instruments that will be able to carry out two-dimensional chromatographic separations, in which case, the first separation would be a space-based separation, LC(x), taking place along one side of the bed and the second separation would be a time-based separation, LC(t), as in classical HPLC but proceeding along the flat column, not along a tube. The apparatus described consists of a pressurization chamber made of a Plexiglas block and a column chamber made of stainless steel. These two chambers are separated by a thin Mylar membrane. The column chamber is a cavity which is filled with a thick layer (ca. 1mm) of the stationary phase. Suitable solvent inlet and outlet ports are located on two opposite sides of the sorbent layer. The design allows the preparation of a homogenous sorbent layer suitable to be used as a chromatographic column, the achievement of effective seals of the stationary phase layer against the chamber edges, and the homogenous flow of the mobile phase along the chamber. The entire width of the sorbent layer area can be used to develop separations or elute samples. The reproducible performance of the apparatus is demonstrated by the chromatographic separations of different dyes. This instrument is essentially designed for testing detector arrays to be used in a two-dimensional LC(x) x LC(t) instrument. The further development of two-dimension separation chromatographs based on the apparatus described is sketched.

  19. Magnetohydrodynamic pressure drop and flow balancing of liquid metal flow in a prototypic fusion blanket manifold

    Science.gov (United States)

    Rhodes, Tyler J.; Smolentsev, Sergey; Abdou, Mohamed

    2018-05-01

    Understanding magnetohydrodynamic (MHD) phenomena associated with the flow of electrically conducting fluids in complex geometry ducts subject to a strong magnetic field is required to effectively design liquid metal (LM) blankets for fusion reactors. Particularly, accurately predicting the 3D MHD pressure drop and flow distribution is important. To investigate these topics, we simulate a LM MHD flow through an electrically non-conducting prototypic manifold for a wide range of flow and geometry parameters using a 3D MHD solver, HyPerComp incompressible MHD solver for arbitrary geometry. The reference manifold geometry consists of a rectangular feeding duct which suddenly expands such that the duct thickness in the magnetic field direction abruptly increases by a factor rexp. Downstream of the sudden expansion, the LM is distributed into several parallel channels. As a first step in qualifying the flow, a magnitude of the curl of the induced Lorentz force was used to distinguish between inviscid, irrotational core flows and boundary and internal shear layers where inertia and/or viscous forces are important. Scaling laws have been obtained which characterize the 3D MHD pressure drop and flow balancing as a function of the flow parameters and the manifold geometry. Associated Hartmann and Reynolds numbers in the computations were ˜103 and ˜101-103, respectively, while rexp was varied from 4 to 12. An accurate model for the pressure drop was developed for the first time for inertial-electromagnetic and viscous-electromagnetic regimes based on 96 computed cases. Analysis shows that flow balance can be improved by lengthening the distance between the manifold inlet and the entrances of the parallel channels by utilizing the effect of flow transitioning to a quasi-two-dimensional state in the expansion region of the manifold.

  20. Long-Wavelength Phonon Scattering in Nonpolar Semiconductors

    DEFF Research Database (Denmark)

    Lawætz, Peter

    1969-01-01

    The long-wavelength acoustic- and optical-phonon scattering of carriers in nonpolar semiconductors is considered from a general point of view. The deformation-potential approximation is defined and it is shown that long-range electrostatic forces give a nontrivial correction to the scattering...... of the very-short-range nature of interactions in a covalent semiconductor....

  1. Measurement and modeling of high-pressure (vapour + liquid) equilibria of (CO{sub 2} + alcohol) binary systems

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez, Jorge E.; Bejarano, Arturo [Departamento de Ingenieria Quimica y Ambiental, Universidad Tecnica Federico Santa Maria, Avda. Espana 1680, Valparaiso (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)

    2010-05-15

    An apparatus based on a static-analytic method assembled in this work was utilized to perform high pressure (vapour + liquid) equilibria measurements with uncertainties estimated at <5%. Complementary isothermal (vapour + liquid) equilibria results are reported for the (CO{sub 2} + 1-propanol), (CO{sub 2} + 2-methyl-1-propanol), (CO{sub 2} + 3-methyl-1-butanol), and (CO{sub 2} + 1-pentanol) binary systems at temperatures of (313, 323, and 333) K, and at pressure range of (2 to 12) MPa. For all the (CO{sub 2} + alcohol) systems, it was visually monitored to insure that there was no liquid immiscibility at the temperatures and pressures studied. The experimental results were correlated with the Peng-Robinson equation of state using the quadratic mixing rules of van der Waals with two adjustable parameters. The calculated (vapour + liquid) equilibria compositions were found to be in good agreement with the experimental values with deviations for the mol fractions <0.12 and <0.05 for the liquid and vapour phase, respectively.

  2. Study on dynamic buckling behavior of a cylindrical liquid storage tanks under seismic excitation. 1st report, effects of liquid pressure on elephant foot bulge

    International Nuclear Information System (INIS)

    Ito, Tomohiro; Morita, Hideyuki; Sugiyama, Akihisa; Kawamoto, Yoji; Sirai, Eiji; Ogo, Hideyasu

    2004-01-01

    When a thin walled cylindrical liquid storage tank is exposed to a very large seismic base excitation, buckling phenomena may be caused such as bending buckling where diamond buckling pattern or elephant foot bulge pattern will be found at the bottom portion, and shear buckling at the middle portion of the tank. In this study, dynamic buckling tests were performed using scale models of thin cylindrical liquid storage tanks for the nuclear power plants. The input seismic acceleration was increased until the elephant foot bulge occurred and the vibrational behavior before and after buckling was investigated. And the effects of static and dynamic liquid pressure on the bending buckling patterns and the buckling critical force was investigated by fundamental tests using small tank models. (author)

  3. The influence of the reactor pressure on the hydrodynamics in a cocurrent gas-liquid trickle-bed reactor

    NARCIS (Netherlands)

    Wammes, W.J.A.; Westerterp, K.R.

    1990-01-01

    The influence of the reactor pressure on the liquid hold-up in the trickle-flow regime and on the transition between trickle-flow and pulse-flow has been investigated in a trickle-flow column operating up to 6.0 MPa with water, and nitrogen or helium as the gas phase. The effect of the gas velocity

  4. High-Pressure Liquid Chromatography of Irradiated Nuclear Fue - Separation of Neodymium for Burn-up Determination

    DEFF Research Database (Denmark)

    Larsen, N. R.

    1979-01-01

    Neodymium is separated from solutions of spent nuclear fuel by high-pressure liquid chromatography in methanol-nitric acid-water media using an anion-exchange column. Chromatograms obtained by monitoring at 280 nm, illustrate the difficulties especially with the fission product ruthenium in nuclear...

  5. Rapid Analysis of Apolar Low Molecular Weight Constituents in Wood Using High Pressure Liquid Chromatography with Evaporative Light Scattering Detection

    NARCIS (Netherlands)

    Claassen, F.W.; Haar, van de C.; Beek, van T.A.; Dorado, J.; Martinez-Inigo, M.; Sierra-Alvarez, R.

    2000-01-01

    A new high pressure liquid chromatographic method with evaporative light scattering detection was developed for the qualitative and quantitative analysis of apolar, low molecular weight constituents in wood. The wood extractives were obtained by means of a 6 h Soxhlet extraction with acetone. The

  6. ATR-IR spectroscopic cell for in situ studies at solid-liquid interface at elevated temperatures and pressures

    NARCIS (Netherlands)

    Koichumanova, Kamila; Visan, Aura; Geerdink, Bert; Lammertink, Rob G.H.; Mojet, Barbara; Seshan, Kulathuiyer; Lefferts, Leonardus

    2017-01-01

    An in situ ATR-IR spectroscopic cell suitable for studies at solid-liquid interface is described including the design and experimental details in continuous flow mode at elevated temperatures (230 °C) and pressures (30 bar). The design parameters considered include the cell geometry, the procedure

  7. Thermodynamic properties of CO2 absorption in hydroxyl ammonium ionic liquids at pressures of (100-1600) kPa

    International Nuclear Information System (INIS)

    Kurnia, K.A.; Harris, F.; Wilfred, C.D.; Abdul Mutalib, M.I.; Murugesan, T.

    2009-01-01

    Solubility of CO 2 in six hydroxyl ammonium ionic liquids 2-hydroxyethanaminium acetate [hea], bis(2-hydroxyethyl)ammonium acetate [bheaa], 2-hydroxy-N-(2-hydroxyethyl)-N-methylethanaminium acetate [hhemea], 2-hydroxyethanaminium lactate [hel], bis(2-hydroxyethyl)ammonium lactate [bheal], 2-hydroxy-N-(2-hydroxyethyl)-N-methylethanaminium lactate [hhemel] at temperatures (298.15, 313.15, and 328.16) K and pressures ranging from (100 to 1600) kPa was determined. From the experimental solubility data, the Henry's constant of CO 2 for each hydroxyl ammonium ionic liquids was estimated and reported as a function of temperature. Furthermore, enthalpy and entropy of absorption were obtained from estimated Henry's constant. The results showed that the solubility increase with increasing pressure and decrease with increasing temperature and the solubility of CO 2 in these six hydroxyl ammonium ionic liquids was in sequence: [hea] > [bheaa] > [hel] > [bheal] > [hhemel] > [hhemea].

  8. Modeling the Rapid Boil-Off of a Cryogenic Liquid When Injected into a Low Pressure Cavity

    Science.gov (United States)

    Lira, Eric

    2016-01-01

    Many launch vehicle cryogenic applications require the modeling of injecting a cryogenic liquid into a low pressure cavity. The difficulty of such analyses lies in accurately predicting the heat transfer coefficient between the cold liquid and a warm wall in a low pressure environment. The heat transfer coefficient and the behavior of the liquid is highly dependent on the mass flow rate into the cavity, the cavity wall temperature and the cavity volume. Testing was performed to correlate the modeling performed using Thermal Desktop and Sinda Fluint Thermal and Fluids Analysis Software. This presentation shall describe a methodology to model the cryogenic process using Sinda Fluint, a description of the cryogenic test set up, a description of the test procedure and how the model was correlated to match the test results.

  9. Investigating Liquid Leak from Pre-Filled Syringes upon Needle Shield Removal: Effect of Air Bubble Pressure.

    Science.gov (United States)

    Chan, Edwin; Maa, Yuh-Fun; Overcashier, David; Hsu, Chung C

    2011-01-01

    This study is to investigate the effect of headspace air pressure in pre-filled syringes on liquid leak (dripping) from the syringe needle upon needle shield removal. Drip tests to measure drip quantity were performed on syringes manually filled with 0.5 or 1.0 mL of various aqueous solutions. Parameters assessed included temperature (filling and test), bulk storage conditions (tank pressure and the type of the pressurized gas), solution composition (pure water, 0.9% sodium chloride, and a monoclonal antibody formulation), and testing procedures. A headspace pressure analyzer was used to verify the drip test method. Results suggested that leakage is indeed caused by headspace pressure increase, and the temperature effect (ideal gas expansion) is a major, but not the only, factor. The dissolved gases in the liquid bulk prior to or during filling may contribute to leakage, as these gases could be released into the headspace due to solubility changes (in response to test temperature and pressure conditions) and cause pressure increase. Needle shield removal procedures were found to cause dripping, but liquid composition played little role. Overall, paying attention to the processing history (pressure and temperature) of the liquid bulk is the key to minimize leakage. The headspace pressure could be reduced by decreasing liquid bulk storage pressure, filling at a higher temperature, or employing lower solubility gas (e.g., helium) for bulk transfer and storage. Leakage could also be mitigated by simply holding the syringe needle pointing upward during needle shield removal. Substantial advances in pre-filled syringe technology development, particularly in syringe filling accuracy, have been made. However, there are factors, as subtle as how the needle shield (or tip cap) is removed, that may affect dosing accuracy. We recently found that upon removal of the tip cap from a syringe held vertically with needle pointed downwards, a small amount of solution, up to 3-4% of

  10. Supercritical fluids in ionic liquids

    NARCIS (Netherlands)

    Kroon, M.C.; Peters, C.J.; Plechkova, N.V.; Seddon, K.R.

    2014-01-01

    Ionic liquids and supercritical fluids are both alternative environmentally benign solvents, but their properties are very different. Ionic liquids are non-volatile but often considered highly polar compounds, whereas supercritical fluids are non-polar but highly volatile compounds. The combination

  11. Effects of easily ionizable elements on the liquid sampling-atmospheric pressure glow discharge

    International Nuclear Information System (INIS)

    Venzie, Jacob L.; Marcus, R. Kenneth

    2006-01-01

    A series of studies has been undertaken to determine the susceptibility of the liquid sampling-atmospheric pressure glow discharge (LS-APGD) atomic emission source to easily ionizable element (EIE) effects. The initial portions of the study involved monitoring the voltage drop across the plasma as a function of the pH to ascertain whether or not the conductivity of the liquid eluent alters the plasma energetics and subsequently the analyte signal strength. It was found that altering the pH (0.0 to 2.0) in the sample matrix did not significantly change the discharge voltage. The emission signal intensities for Cu(I) 327.4 nm, Mo(I) 344.7 nm, Sc(I) 326.9 nm and Hg(I) 253.6 nm were measured as a function of the easily ionizable element (sodium and calcium) concentration in the injection matrix. A range of 0.0 to 0.1% (w/v) EIE in the sample matrix did not cause a significant change in the Cu, Sc, and Mo signal-to-background ratios, with only a slight change noted for Hg. In addition to this test of analyte response, the plasma energetics as a function of EIE concentration are assessed using the ratio of Mg(II) to Mg(I) (280.2 nm and 285.2 nm, respectively) intensities. The Mg(II)/Mg(I) ratio showed that the plasma energetics did not change significantly over the same range of EIE addition. These results are best explained by the electrolytic nature of the eluent acting as an ionic (and perhaps spectrochemical) buffer

  12. Equation of costs and function objective for the optimization of the design of nets of flow of liquids to pressure

    International Nuclear Information System (INIS)

    Narvaez R, Paulo Cesar; Galeano P, Haiver

    2002-01-01

    Optimal design problem of liquid distribution systems has been viewed as the selection of pipe sizes and pumps, which will minimize overall costs, accomplishing the flow and pressure constraints. There is a set of methods for least cost design of liquids distribution networks (6). In the last years, some of them have been studied broadly: linear programming (1, 4, 5, 7], non-linear programming [8, 9], and genetic algorithms (3, 10, 13). This paper describes the development of a cost equation and the objective function for liquid distribution networks that together to the mathematical model and the solution method of the flow problem developed by Narvaez (11), were used by in a computer model that involves the application of an genetic algorithm to the problem of least cost design of liquids distribution networks

  13. A high pressure liquid chromatography method for separation of prolactin forms.

    Science.gov (United States)

    Bell, Damon A; Hoad, Kirsten; Leong, Lillian; Bakar, Juwaini Abu; Sheehan, Paul; Vasikaran, Samuel D

    2012-05-01

    Prolactin has multiple forms and macroprolactin, which is thought not to be bioavailable, can cause a raised serum prolactin concentration. Gel filtration chromatography (GFC) is currently the gold standard method for separating macroprolactin, but is labour-intensive. Polyethylene glycol (PEG) precipitation is suitable for routine use but may not always be accurate. We developed a high pressure liquid chromatography (HPLC) assay for macroprolactin measurement. Chromatography was carried out using an Agilent Zorbax GF-250 (9.4 × 250 mm, 4 μm) size exclusion column and 50 mmol/L Tris buffer with 0.15 mmol/L NaCl at pH 7.2 as mobile phase, with a flow rate of 1 mL/min. Serum or plasma was diluted 1:1 with mobile phase and filtered and 100 μL injected. Fractions of 155 μL were collected for prolactin measurement and elution profile plotted. The area under the curve of each prolactin peak was calculated to quantify each prolactin form, and compared with GFC. Clear separation of monomeric-, big- and macroprolactin forms was achieved. Quantification was comparable to GFC and precision was acceptable. Total time from injection to collection of the final fraction was 16 min. We have developed an HPLC method for quantification of macroprolactin, which is rapid and easy to perform and therefore can be used for routine measurement.

  14. How to Assess Creative Thinking Skill in Making Products of Liquid Pressure?

    Science.gov (United States)

    Chasanah, L.; Kaniawati, I.; Hernani, H.

    2017-09-01

    The primary skills that must be possessed in the 21st century curriculum are learning and innovation skills. One of the learning strategies that can train students to innovate and improve creative thinking skills is by applying Science, Technology, Engineering and Mathematics (STEM) in learning. Based on an interview to one of the science teachers that learning that aims to train learning and innovation skills has not been applied to learning in the classroom because there is not enough time, learning materials and assessment instruments used. This study aims to determine the results of the implementation of performance assessment of creative thinking skills on STEM-based learning in junior high school for the material of liquid pressure. This research uses descriptive method. Participants in this study were junior high school students 8th in Kudus area. The research instrument consists of observation sheet, performance assessment and documentation. The result showed that creative thinking skills performance assessment can assess student’s creativity in making products of STEM-based learning for junior high school.

  15. Effect of pressurized liquids on extraction of antioxidants from Chlorella vulgaris.

    Science.gov (United States)

    Cha, Kwang Hyun; Kang, Suk Woo; Kim, Chul Young; Um, Byung Hun; Na, Ye Rim; Pan, Cheol-Ho

    2010-04-28

    Chlorella vulgaris is a green microalga that contains various antioxidants, such as carotenoids and chlorophylls. In this study, antioxidants from C. vulgaris were extracted using pressurized liquid extraction (PLE), which has been recently used for bioactive compound extraction. The antioxidant capacity of individual compounds in chlorella was determined by online HPLC ABTS(*+) analysis. According to the antioxidant analysis of total extracts, the extraction yield, radical scavenging activity, and phenolic compounds using PLE were relatively high compared to those obtained using maceration or ultrasound-assisted extraction. On the basis of online HPLC ABTS(*+) analysis, the 15 major antioxidants from chlorella extracts were identified as hydrophilic compounds, lutein and its isomers, chlorophylls, and chlorophyll derivatives. Using PLE at high temperature (85-160 degrees C) significantly increased antioxidant extraction from chlorella, improving the formation of hydrophilic compounds and yielding more antioxidative chlorophyll derivatives. Online HPLC ABTS(*+) analysis was a useful tool for the separation of main antioxidants from PLE extracts and allowed the simultaneous measurement of their antioxidant capacity, which clearly showed that PLE is an excellent method for extracting antioxidants from C. vulgaris.

  16. Pressurized liquid extraction of ginger (Zingiber officinale Roscoe) with bioethanol: an efficient and sustainable approach.

    Science.gov (United States)

    Hu, Jiajin; Guo, Zheng; Glasius, Marianne; Kristensen, Kasper; Xiao, Langtao; Xu, Xuebing

    2011-08-26

    To develop an efficient green extraction approach for recovery of bioactive compounds from natural plants, we examined the potential of pressurized liquid extraction (PLE) of ginger (Zingiber officinale Roscoe) with bioethanol/water as solvents. The advantages of PLE over other extraction approaches, in addition to reduced time/solvent cost, the extract of PLE showed a distinct constituent profile from that of Soxhlet extraction, with significantly improved recovery of diarylheptanoids, etc. Among the pure solvents tested for PLE, bioethanol yield the highest efficiency for recovering most constituents of gingerol-related compounds; while for a broad concentration spectrum of ethanol aqueous solutions, 70% ethanol gave the best performance in terms of yield of total extract, complete constituent profile and recovery of most gingerol-related components. PLE with 70% bioethanol operated at 1500 psi and 100 °C for 20 min (static extraction time: 5 min) is recommended as optimized extraction conditions, achieving 106.8%, 109.3% and 108.0% yield of [6]-, [8]- and [10]-gingerol relative to the yield of corresponding constituent obtained by 8h Soxhlet extraction (absolute ethanol as extraction solvent). Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Determination of boron in nuclear materials at subppm levels by high pressure liquid chromatography (HPLC)

    International Nuclear Information System (INIS)

    Rao, Radhika M.; Aggarwal, S.K.

    2002-11-01

    Experiments were conducted for the determination of boron in U 3 O 8 powder, aluminium metal and milliQ water using dynamically modified Reversed Phase High Pressure Liquid Chromatography (RP-HPLC) and using two precolumn chromogenic agents viz. chromotropic acid and curcumin for complexing boron. The complex was separated from the excess of reagent and determined by HPLC. When present in subppm levels, chromotropic acid was used successfully only for determination boron in water samples. For determination of boron at subppm levels in uranium and aluminium samples, curcumin was used as the precolumn chromogenic agent. The boron curcumin complex (rosocyanin) was formed after extraction of boron with 2-ethyl-l, 3-hexane diol (EHD). The rosocyanin complex was then separated from excess curcumin by displacement chromatography. Linear calibration curves for boron amounts in the range of 0.02 μg to 0.5 μg were developed with correlation coefficients varying from 0.997 to 0.999 and were used for the determination of boron in aluminium and uranium samples. Precision of about 10% was achieved in samples containing less than 1 ppmw of boron. Detection limit of this method is 0.01 μg boron. (author)

  18. Liquid sampling-atmospheric pressure glow discharge as a secondary excitation source: Assessment of plasma characteristics

    Science.gov (United States)

    Manard, Benjamin T.; Gonzalez, Jhanis J.; Sarkar, Arnab; Dong, Meirong; Chirinos, Jose; Mao, Xianglei; Russo, Richard E.; Marcus, R. Kenneth

    The liquid sampling-atmospheric pressure glow discharge (LS-APGD) has been assessed as a secondary excitation source with a parametric evaluation regarding carrier gas flow rate, applied current, and electrode distance. With this parametric evaluation, plasma optical emission was monitored in order to obtain a fundamental understanding with regards to rotational temperature (Trot), excitation temperature (Texc), electron number density (ne), and plasma robustness. Incentive for these studies is not only for a greater overall fundamental knowledge of the APGD, but also in instrumenting a secondary excitation/ionization source following laser ablation (LA). Rotational temperatures were determined through experimentally fitting of the N2 and OH molecular emission bands while atomic excitation temperatures were calculated using a Boltzmann distribution of He and Mg atomic lines. The rotational and excitation temperatures were determined to be ~ 1000 K and ~ 2700 K respectively. Electron number density was calculated to be on the order of ~ 3 × 1015 cm- 3 utilizing Stark broadening effects of the Hα line of the Balmer series and a He I transition. In addition, those diagnostics were performed introducing magnesium (by solution feed and laser ablation) into the plasma in order to determine any perturbation under heavy matrix sampling. The so-called plasma robustness factor, derived by monitoring Mg II/Mg I emission ratios, is also employed as a reflection of potential perturbations in microplasma energetics across the various operation conditions and sample loadings. While truly a miniaturized source (laser ablation sample introduction.

  19. Non-linearity parameter of binary liquid mixtures at elevated pressures

    Indian Academy of Sciences (India)

    . Ultrasonic studies in liquid mixtures provide valuable information about structure and interaction in such systems. The present investigation comprises of theoretical evaluation of the acoustic non-linearity parameter / of four binary liquid ...

  20. studies dielectric behaviour of some long chain alcohols and their mixtures with a non-polar solvent at various concentration

    International Nuclear Information System (INIS)

    Yaqub, M.; Ahmed, S.S.; Hussain, A.

    2006-01-01

    Dielectric constant, refractive index and the Kirkwood linear correlation factor of 1-propanol, 1-butanol and 1-pentanol in mixtures with carbon tetrachloride at various concentration have been measured at fixed frequency (100 KHz) at 303.15 K. For the study of dielectric properties of polar molecules in a non-polar solvent at different concentrations, polarization per unit volume and excess free-energy of mixing were evaluated at this temperature. In order to study the association of polar molecules in such a non-polar solvent, the Kirkwood correlation factor (g) between molecular pairs, which exists due to the hydrogen bond association suggesting the presence of some dimension in the liquid phase with a number of dimmers, was determined. The refractive index and dielectric constant measurements are expected to shed some light on the configuration of molecules in various mixtures, and give some idea about the specific interactions between components, which decrese with the increase in the concentration of alcohol. All the three mixtures showed different behaviour for the value of correlation factor (g) as a function of concentration. The response of 1-pentanol was broadly identical to that of small chain alcohols. The different behaviour of the correlation factor (g) was interpreted in terms of the Kirkwood-Frohlich theory, as it takes into account, explicitly, such type of short and long range interactions of a mixture of polar molecules with non-polar solvents. (author)

  1. Photophysical properties of coumarin-120: Unusual behavior in nonpolar solvents

    International Nuclear Information System (INIS)

    Pal, Haridas; Nad, Sanjukta; Kumbhakar, Manoj

    2003-01-01

    Photophysical properties of coumarin-120 (C120; 7-amino-4-methyl-1,2-benzopyrone) dye have been investigated in different solvents using steady-state and time-resolved fluorescence and picosecond laser flash photolysis (LFP) and nanosecond pulse radiolysis (PR) techniques. C120 shows unusual photophysical properties in nonpolar solvents compared to those in other solvents of moderate to higher polarities. Where the Stokes shifts (Δν-bar=ν-bar abs -ν-bar fl ), fluorescence quantum yields (Φ f ), and fluorescence lifetimes (τ f ) show more or less linear correlation with the solvent polarity function Δf={(ε-1)/(2ε+1)-(n 2 -1)/(2n 2 +1)}, all these parameters are unusually lower in nonpolar solvents. Unlike in other solvents, both Φ f and τ f in nonpolar solvents are also strongly temperature dependent. It is indicated that the excited singlet (S 1 ) state of C120 undergoes a fast activation-controlled nonradiative deexcitation in nonpolar solvents, which is absent in all other solvents. LFP and PR studies indicate that the intersystem crossing process is negligible for the present dye in all the solvents studied. Photophysical behavior of C120 in nonpolar solvent has been rationalized assuming that in these solvents the dye exists in a nonpolar structure, with its 7-NH 2 group in a pyramidal configuration. In this structure, since the 7-NH 2 group is bonded to the 1,2-benzopyrone moiety by a single bond, the former group can undergo a fast flip-flop motion, which in effect causes the fast nonradiative deexcitation of the dye excited state. In moderate to higher polarity solvents, it is indicated that the dye exists in an intramolecular charge-transfer structure, where the bond between 7-NH 2 group and the 1,2-benzopyrone moiety attains substantial double bond character. In this structure, the flip-flop motion of the 7-NH 2 group is highly restricted and thus there is no fast nonradiative deexcitation process for the excited dye

  2. Thermodynamic properties by equation of state and from Ab initio molecular dynamics of liquid potassium under pressure

    Science.gov (United States)

    Li, Huaming; Tian, Yanting; Sun, Yongli; Li, Mo; Nonequilibrium materials; physics Team; Computational materials science Team

    In this work, we apply a general equation of state of liquid and Ab initio molecular-dynamics method to study thermodynamic properties in liquid potassium under high pressure. Isothermal bulk modulus and molar volume of molten sodium are calculated within good precision as compared with the experimental data. The calculated internal energy data and the calculated values of isobaric heat capacity of molten potassium show the minimum along the isothermal lines as the previous result obtained in liquid sodium. The expressions for acoustical parameter and nonlinearity parameter are obtained based on thermodynamic relations from the equation of state. Both parameters for liquid potassium are calculated under high pressure along the isothermal lines by using the available thermodynamic data and numeric derivations. Furthermore, Ab initio molecular-dynamics simulations are used to calculate some thermodynamic properties of liquid potassium along the isothermal lines. Scientific Research Starting Foundation from Taiyuan university of Technology, Shanxi Provincial government (``100-talents program''), China Scholarship Council and National Natural Science Foundation of China (NSFC) under Grant No. 51602213.

  3. High pressure and temperature structure of liquid and solid Cd: implications for the melting curve of Cd

    International Nuclear Information System (INIS)

    Raju, S V; Williams, Q; Geballe, Z M; Godwal, B K; Jeanloz, R; Kalkan, B

    2014-01-01

    The structure of cadmium was characterized in both the solid and liquid forms at pressures to 10 GPa using in situ x-ray diffraction measurements in a resistively heated diamond anvil cell. The distorted hexagonal structure of solid cadmium persists at high pressures and temperatures, with anomalously large c/a ratio of Cd becoming larger as the melting curve is approached. The measured structure factor S(Q) for the melt reveals that the cadmium atoms are spaced about 0.6 Angstroms apart. The melt structure remains notably constant with increasing pressure, with the first peak in the structure factor remaining mildly asymmetric, in accord with the persistence of an anisotropic bonding environment within the liquid. Evolution of powder diffraction patterns up to the temperature of melting revealed the stability of the ambient-pressure hcp structure up to a pressure of 10 GPa. The melting curve has a positive Clausius–Clapeyron slope, and its slope is in good agreement with data from other techniques. We find deviations in the melting curve from Lindemann law type behavior for pressures above 1 GPa. (paper)

  4. Quantum molecular dynamics simulations of the thermophysical properties of shocked liquid ammonia for pressures up to 1.3 TPa.

    Science.gov (United States)

    Li, Dafang; Zhang, Ping; Yan, Jun

    2013-10-07

    We investigate via quantum molecular-dynamics simulations the thermophysical properties of shocked liquid ammonia up to the pressure 1.3 TPa and temperature 120,000 K. The principal Hugoniot is predicted from the wide-range equation of state, which agrees well with the available experimental measurements up to 64 GPa. Our systematic study of the structural properties demonstrates that the liquid ammonia undergoes a gradual phase transition along the Hugoniot. At about 4800 K, the system transforms into a metallic, complex mixture state consisting of NH3, N2, H2, N, and H. Furthermore, we discuss the implications for the interiors of Uranus and Neptune.

  5. Nanoencapsulation of Fullerenes in Organic Structures with Nonpolar Cavities

    International Nuclear Information System (INIS)

    Murthy, C. N.

    2005-01-01

    The formation of supramolecular structures, assemblies, and arrays held together by weak intermolecular interactions and non-covalent binding mimicking natural processes has been used in applications being anticipated in nanotechnology, biotechnology and the emerging field of nanomedicine. Encapsulation of C 60 fullerene by cyclic molecules like cyclodextrins and calixarenes has potential for a number of applications. Similarly, biomolecules like lysozyme also have been shown to encapsulate C 60 fullerene. This poster article reports the recent trends and the results obtained in the nanoencapsulation of fullerenes by biomolecules containing nonpolar cavities. Lysozyme was chosen as the model biomolecule and it was observed that there is no covalent bond formed between the bimolecule and the C 60 fullerene. This was confirmed from fluorescence energy transfer studies. UV-Vis studies further supported this observation that it is possible to selectively remove the C 60 fullerene from the nonpolar cavity. This behavior has potential in biomedical applications

  6. Photonic Crystal Polarizing and Non-Polarizing Beam Splitters

    International Nuclear Information System (INIS)

    Chun-Ying, Guan; Jin-Hui, Shi; Li-Boo, Yuan

    2008-01-01

    A polarizing beam splitter (PBS) and a non-polarizing beam splitter (NPBS) based on a photonic crystal (PC) directional coupler are demonstrated. The photonic crystal directional coupler consists of a hexagonal lattice of dielectric pillars in air and has a complete photonic band gap. The photonic band structure and the band gap map are calculated using the plane wave expansion (PWE) method. The splitting properties of the splitter are investigated numerically using the finite difference time domain (FDTD) method

  7. Fast and comprehensive analysis of secondary metabolites in cocoa products using ultra high-performance liquid chromatography directly after pressurized liquid extraction.

    Science.gov (United States)

    Damm, Irina; Enger, Eileen; Chrubasik-Hausmann, Sigrun; Schieber, Andreas; Zimmermann, Benno F

    2016-08-01

    Fast methods for the extraction and analysis of various secondary metabolites from cocoa products were developed and optimized regarding speed and separation efficiency. Extraction by pressurized liquid extraction is automated and the extracts are analyzed by rapid reversed-phase ultra high-performance liquid chromatography and normal-phase high-performance liquid chromatography methods. After extraction, no further sample treatment is required before chromatographic analysis. The analytes comprise monomeric and oligomeric flavanols, flavonols, methylxanthins, N-phenylpropenoyl amino acids, and phenolic acids. Polyphenols and N-phenylpropenoyl amino acids are separated in a single run of 33 min, procyanidins are analyzed by normal-phase high-performance liquid chromatography within 16 min, and methylxanthins require only 6 min total run time. A fourth method is suitable for phenolic acids, but only protocatechuic acid was found in relevant quantities. The optimized methods were validated and applied to 27 dark chocolates, one milk chocolate, two cocoa powders and two food supplements based on cocoa extract. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Influence of cross-sectional geometry on the sensitivity and hysteresis of liquid-phase electronic pressure sensors

    Science.gov (United States)

    Park, Yong-Lae; Tepayotl-Ramirez, Daniel; Wood, Robert J.; Majidi, Carmel

    2012-11-01

    Cross-sectional geometry influences the pressure-controlled conductivity of liquid-phase metal channels embedded in an elastomer film. These soft microfluidic films may function as hyperelastic electric wiring or sensors that register the intensity of surface pressure. As pressure is applied to the elastomer, the cross-section of the embedded channel deforms, and the electrical resistance of the channel increases. In an effort to improve sensitivity and reduce sensor nonlinearity and hysteresis, we compare the electrical response of 0.25 mm2 channels with different cross-sectional geometries. We demonstrate that channels with a triangular or concave cross-section exhibit the least nonlinearity and hysteresis over pressures ranging from 0 to 70 kPa. These experimental results are in reasonable agreement with predictions made by theoretical calculations that we derive from elasticity and Ohm's Law.

  9. Two complementary reversed-phase separations for comprehensive coverage of the semipolar and nonpolar metabolome.

    Science.gov (United States)

    Naser, Fuad J; Mahieu, Nathaniel G; Wang, Lingjue; Spalding, Jonathan L; Johnson, Stephen L; Patti, Gary J

    2018-02-01

    Although it is common in untargeted metabolomics to apply reversed-phase liquid chromatography (RPLC) and hydrophilic interaction liquid chromatography (HILIC) methods that have been systematically optimized for lipids and central carbon metabolites, here we show that these established protocols provide poor coverage of semipolar metabolites because of inadequate retention. Our objective was to develop an RPLC approach that improved detection of these metabolites without sacrificing lipid coverage. We initially evaluated columns recently released by Waters under the CORTECS line by analyzing 47 small-molecule standards that evenly span the nonpolar and semipolar ranges. An RPLC method commonly used in untargeted metabolomics was considered a benchmarking reference. We found that highly nonpolar and semipolar metabolites cannot be reliably profiled with any single method because of retention and solubility limitations of the injection solvent. Instead, we optimized a multiplexed approach using the CORTECS T3 column to analyze semipolar compounds and the CORTECS C 8 column to analyze lipids. Strikingly, we determined that combining these methods allowed detection of 41 of the total 47 standards, whereas our reference RPLC method detected only 10 of the 47 standards. We then applied credentialing to compare method performance at the comprehensive scale. The tandem method showed more than a fivefold increase in credentialing coverage relative to our RPLC benchmark. Our results demonstrate that comprehensive coverage of metabolites amenable to reversed-phase separation necessitates two reconstitution solvents and chromatographic methods. Thus, we suggest complementing HILIC methods with a dual T3 and C 8 RPLC approach to increase coverage of semipolar metabolites and lipids for untargeted metabolomics. Graphical abstract Analysis of semipolar and nonpolar metabolites necessitates two reversed-phase chromatography (RPLC) methods, which extend metabolome coverage more

  10. Evaluation of adherence to ambulatory liquid oxygen treatment: are commercialized dual-pressure transducers helpful?

    Science.gov (United States)

    van Zeller, Mafalda; Eusébio, Ermelinda; Almeida, João; Winck, João Carlos

    2014-09-01

    Treatment adherence is widely recognized as a critical problem in long-term oxygen therapy, particularly in ambulatory liquid oxygen (LOX) systems. Adherence-monitoring strategies may be helpful in managing patients. We evaluated subjects' adherence to LOX using VisionOx and compared these results with the subjects' own adherence diaries and self-reported perceptions of use. Patients using LOX were recruited for a clinical interview; the number of days/week and the mean time of use according to subjects' perceptions were recorded. A 14-day diary was provided for every subject while VisionOx was attached to the LOX. VisionOx is a small device that uses pressure transducers to detect oxygen flow and the subject's breathing frequency. Information is stored and downloaded using dedicated software. Nineteen subjects were included (57.9% male with a median age of 63 years). When asked about the perception of LOX use, subjects self-reported using the device for a median of 100.0% of days (78.9% reported to have used it every day) for a median time of 180 min/day. According to data from VisionOx and subjects' diaries during the 14-day evaluation period, the median use was 92.8% of days for 210 min/day. No difference was found between the diaries and VisionOx data. Regarding subjects' perceptions of use, the declared use of LOX percent was significantly higher than reported in the diaries (P = .045) and VisionOx monitoring (P = .045) even though both underestimated the median use per day. Subjects overestimated adherence to LOX therapy (when measuring percent of days of use) compared to adherence diary and objective adherence monitoring. Because no significant difference was found comparing the diaries and VisionOx use, either may be helpful in clinical practice. Copyright © 2014 by Daedalus Enterprises.

  11. Is high pressure liquid chromatography an effective screening tool for characterization of molecular defects in hemoglobinopathies?

    Directory of Open Access Journals (Sweden)

    Nikhil Moorchung

    2013-01-01

    Full Text Available Introduction: Hemoglobinopathies constitute entities that are generated by either abnormal hemoglobin or thalassemias. high pressure liquid chromatography (HPLC is one of the best methods for screening and detection of various hemoglobinopathies but it has intrinsic interpretive problems. The study was designed to evaluate the different mutations seen in cases of hemoglobinopathies and compare the same with screening tests. Materials and Methods: 68 patients of hemoglobinopathies were screened by HPLC. Mutation studies in the beta globin gene was performed using the polymerase chain reaction (PCR-based allele-specific Amplification Refractory Mutation System (ARMS. Molecular analysis for the sickle cell mutation was done by standard methods. Results: The IVS 1/5 mutation was the commonest mutation seen and it was seen in 26 (38.23% of the cases. This was followed by the IVS 1/1, codon 41/42, codon 8/9, del 22 mutation, codon 15 mutation and the -619 bp deletion. No mutation was seen in eight cases. There was a 100% concordance between the sickle cell trait as diagnosed by HPLC and genetic testing. Discussion and Conclusion: Our study underlies the importance of molecular testing in all cases of hemoglobinopathies. Although HPLC is a useful screening tool, molecular testing is very useful in accurately diagnosing the mutations. Molecular testing is especially applicable in cases with an abnormal hemoglobin (HbD, HbE and HbS because there may be a concomitant inheritance of a beta thalassemia mutation. Molecular testing is the gold standard when it comes to the diagnosis of hemoglobinopathies.

  12. Assessment of radiochemical purity of [{sup 18}F]fludeoxyglucose by high pressure liquid chromatography (HPLC)

    Energy Technology Data Exchange (ETDEWEB)

    Lacerda, Aline E.; Silva, Juliana B.; Silveira, Marina B.; Ferreira, Soraya Z., E-mail: radiofarmacoscdtn@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Unidade de Pesquisa e Producao de Radiofarmacos

    2011-07-01

    The quality control of [{sup 18}F]fludeoxyglucose ({sup 18}FDG) has received attention due to its increasing clinical use. Although the quality requirements of {sup 18}FDG are established in various pharmacopoeia, the suitability of all testing methods used should be verified under actual conditions of use and documented. The aim of this study was to develop a high pressure liquid chromatography (HPLC) method for radiochemical purity evaluation of {sup 18}FDG, based on pharmacopoeia references, and to verify its suitability for routine quality control in our centre. HPLC analysis was performed with an Agilent HPLC. {sup 18}FDG and impurities were separated on an anion-exchange column by isocratic elution with 0.1 M NaOH as the mobile phase. Detection was accomplished with refractive index and NaI (Tl) scintillation detectors. The flow rate of the mobile phase was set at 0.8 mL/min and the column temperature was kept at 35 deg C. Specificity, linearity, precision and robustness were assessed to verify if the method was adequate for its intended purpose. Retention time of {sup 18}FDG was not affected by the presence of other components of the formulation and a good peak resolution was achieved. The analytical curve of {sup 18}FDG was linear, with a correlation coefficient value of 0.9995. Intraday repeatable precision, reported as the relative standard deviation, was 0.11%. Analytical procedure remained unaffected by small variations in mobile phase flow rate. Results evidenced that HPLC is suitable for radiochemical purity evaluation of {sup 18}FDG, considering operational conditions of our laboratory. (author)

  13. 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.

  14. A Straightforward Method for Glucosinolate Extraction and Analysis with High-pressure Liquid Chromatography (HPLC).

    Science.gov (United States)

    Grosser, Katharina; van Dam, Nicole M

    2017-03-15

    Glucosinolates are a well-studied and highly diverse class of natural plant compounds. They play important roles in plant resistance, rapeseed oil quality, food flavoring, and human health. The biological activity of glucosinolates is released upon tissue damage, when they are mixed with the enzyme myrosinase. This results in the formation of pungent and toxic breakdown products, such as isothiocyanates and nitriles. Currently, more than 130 structurally different glucosinolates have been identified. The chemical structure of the glucosinolate is an important determinant of the product that is formed, which in turn determines its biological activity. The latter may range from detrimental (e.g., progoitrin) to beneficial (e.g., glucoraphanin). Each glucosinolate-containing plant species has its own specific glucosinolate profile. For this reason, it is important to correctly identify and reliably quantify the different glucosinolates present in brassicaceous leaf, seed, and root crops or, for ecological studies, in their wild relatives. Here, we present a well-validated, targeted, and robust method to analyze glucosinolate profiles in a wide range of plant species and plant organs. Intact glucosinolates are extracted from ground plant materials with a methanol-water mixture at high temperatures to disable myrosinase activity. Thereafter, the resulting extract is brought onto an ion-exchange column for purification. After sulfatase treatment, the desulfoglucosinolates are eluted with water and the eluate is freeze-dried. The residue is taken up in an exact volume of water, which is analyzed by high-pressure liquid chromatography (HPLC) with a photodiode array (PDA) or ultraviolet (UV) detector. Detection and quantification are achieved by conducting comparisons of the retention times and UV spectra of commercial reference standards. The concentrations are calculated based on a sinigrin reference curve and well-established response factors. The advantages and

  15. Assessment of radiochemical purity of [18F]fludeoxyglucose by high pressure liquid chromatography (HPLC)

    International Nuclear Information System (INIS)

    Lacerda, Aline E.; Silva, Juliana B.; Silveira, Marina B.; Ferreira, Soraya Z.

    2011-01-01

    The quality control of [ 18 F]fludeoxyglucose ( 18 FDG) has received attention due to its increasing clinical use. Although the quality requirements of 18 FDG are established in various pharmacopoeia, the suitability of all testing methods used should be verified under actual conditions of use and documented. The aim of this study was to develop a high pressure liquid chromatography (HPLC) method for radiochemical purity evaluation of 18 FDG, based on pharmacopoeia references, and to verify its suitability for routine quality control in our centre. HPLC analysis was performed with an Agilent HPLC. 18 FDG and impurities were separated on an anion-exchange column by isocratic elution with 0.1 M NaOH as the mobile phase. Detection was accomplished with refractive index and NaI (Tl) scintillation detectors. The flow rate of the mobile phase was set at 0.8 mL/min and the column temperature was kept at 35 deg C. Specificity, linearity, precision and robustness were assessed to verify if the method was adequate for its intended purpose. Retention time of 18 FDG was not affected by the presence of other components of the formulation and a good peak resolution was achieved. The analytical curve of 18 FDG was linear, with a correlation coefficient value of 0.9995. Intraday repeatable precision, reported as the relative standard deviation, was 0.11%. Analytical procedure remained unaffected by small variations in mobile phase flow rate. Results evidenced that HPLC is suitable for radiochemical purity evaluation of 18 FDG, considering operational conditions of our laboratory. (author)

  16. Studies on thermo-acoustic parameters in binary liquid mixtures of phosphinic acid (Cyanex 272) with different diluents at temperature 303.15 K: an ultrasonic study

    International Nuclear Information System (INIS)

    Kamila, Susmita; Jena, Satyaban; Swain, Bipin Bihari

    2005-01-01

    Acoustical investigations for the binary mixtures of phosphinic acid (Cyanex 272), used as liquid-liquid extractant, have been made in various diluents such as benzene, toluene, and xylene from ultrasonic velocity and density measurements at temperature 303.15 K and atmospheric pressure. This study involves evaluation of different thermo-acoustic parameters along with the excess properties, which are interpreted in the light of molecular interaction between a polar extractant, Cyanex 272 with non-polar diluent, benzene and weakly polar diluents, toluene and xylene. The excess values are correlated using Redlich-Kister polynomial equation, and corresponding adjustable parameters are derived

  17. Density measurements of liquid 2-propanol at temperatures between (280 and 393) K and at pressures up to 10 MPa

    International Nuclear Information System (INIS)

    Stringari, Paolo; Scalabrin, Giancarlo; Valtz, A.; Richon, D.

    2009-01-01

    Liquid densities for 2-propanol have been measured at T = (280, 300, 325, 350, 375, and 393) K from about atmospheric pressure up to 10 MPa using a vibrating tube densimeter. The period of vibration has been converted into density using the Forced Path Mechanical Calibration method. The R134a has been used as reference fluid for T ≤ 350 K and water for T > 350 K. The uncertainty of the measurements is lower than ±0.05%. The measured liquid densities have been correlated with a Starling BWR equation with an overall AAD of 0.025%. The same BWR equation agrees within an AAD lower than 0.2% with the experimental values available in the literature over the same temperature and pressure range

  18. Optimization of Pressurized Liquid Extraction of Three Major Acetophenones from Cynanchum bungei Using a Box-Behnken Design

    Science.gov (United States)

    Li, Wei; Zhao, Li-Chun; Sun, Yin-Shi; Lei, Feng-Jie; Wang, Zi; Gui, Xiong-Bin; Wang, Hui

    2012-01-01

    In this work, pressurized liquid extraction (PLE) of three acetophenones (4-hydroxyacetophenone, baishouwubenzophenone, and 2,4-dihydroxyacetophenone) from Cynanchum bungei (ACB) were investigated. The optimal conditions for extraction of ACB were obtained using a Box-Behnken design, consisting of 17 experimental points, as follows: Ethanol (100%) as the extraction solvent at a temperature of 120 °C and an extraction pressure of 1500 psi, using one extraction cycle with a static extraction time of 17 min. The extracted samples were analyzed by high-performance liquid chromatography using an UV detector. Under this optimal condition, the experimental values agreed with the predicted values by analysis of variance. The ACB extraction yield with optimal PLE was higher than that obtained by soxhlet extraction and heat-reflux extraction methods. The results suggest that the PLE method provides a good alternative for acetophenone extraction. PMID:23203079

  19. Optimization of Pressurized Liquid Extraction of Three Major Acetophenones from Cynanchum bungei Using a Box-Behnken Design

    Directory of Open Access Journals (Sweden)

    Hui Wang

    2012-11-01

    Full Text Available In this work, pressurized liquid extraction (PLE of three acetophenones (4-hydroxyacetophenone, baishouwubenzophenone, and 2,4-dihydroxyacetophenone from Cynanchum bungei (ACB were investigated. The optimal conditions for extraction of ACB were obtained using a Box-Behnken design, consisting of 17 experimental points, as follows: Ethanol (100% as the extraction solvent at a temperature of 120 °C and an extraction pressure of 1500 psi, using one extraction cycle with a static extraction time of 17 min. The extracted samples were analyzed by high-performance liquid chromatography using an UV detector. Under this optimal condition, the experimental values agreed with the predicted values by analysis of variance. The ACB extraction yield with optimal PLE was higher than that obtained by soxhlet extraction and heat-reflux extraction methods. The results suggest that the PLE method provides a good alternative for acetophenone extraction.

  20. Quantitative study of sniffer leak rate and pressure drop leak rate of liquid nitrogen panels of SST-1 tokamak

    Science.gov (United States)

    Pathan, F. S.; Khan, Z.; Semwal, P.; Raval, D. C.; Joshi, K. S.; Thankey, P. L.; Dhanani, K. R.

    2008-05-01

    Steady State Super-conducting (SST-1) Tokamak is in commissioning stage at Institute for Plasma Research. Vacuum chamber of SST-1 Tokamak consists of 1) Vacuum vessel, an ultra high vacuum (UHV) chamber, 2) Cryostat, a high vacuum (HV) chamber. Cryostat encloses the liquid helium cooled super-conducting magnets (TF and PF), which require the thermal radiation protection against room temperature. Liquid nitrogen (LN2) cooled panels are used to provide thermal shield around super-conducting magnets. During operation, LN2 panels will be under pressurized condition and its surrounding (cryostat) will be at high vacuum. Hence, LN2 panels must have very low leak rate. This paper describes an experiment to study the behaviour of the leaks in LN2 panels during sniffer test and pressure drop test using helium gas.

  1. Quantitative study of sniffer leak rate and pressure drop leak rate of liquid nitrogen panels of SST-1 tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Pathan, F S; Khan, Z; Semwal, P; Raval, D C; Joshi, K S; Thankey, P L; Dhanani, K R [Institute for Plasma Research, Bhat, Gandhinagar - 382 428, Gujarat (India)], E-mail: firose@ipr.res.in

    2008-05-01

    Steady State Super-conducting (SST-1) Tokamak is in commissioning stage at Institute for Plasma Research. Vacuum chamber of SST-1 Tokamak consists of 1) Vacuum vessel, an ultra high vacuum (UHV) chamber, 2) Cryostat, a high vacuum (HV) chamber. Cryostat encloses the liquid helium cooled super-conducting magnets (TF and PF), which require the thermal radiation protection against room temperature. Liquid nitrogen (LN2) cooled panels are used to provide thermal shield around super-conducting magnets. During operation, LN{sub 2} panels will be under pressurized condition and its surrounding (cryostat) will be at high vacuum. Hence, LN{sub 2} panels must have very low leak rate. This paper describes an experiment to study the behaviour of the leaks in LN{sub 2} panels during sniffer test and pressure drop test using helium gas.

  2. Quantitative study of sniffer leak rate and pressure drop leak rate of liquid nitrogen panels of SST-1 tokamak

    International Nuclear Information System (INIS)

    Pathan, F S; Khan, Z; Semwal, P; Raval, D C; Joshi, K S; Thankey, P L; Dhanani, K R

    2008-01-01

    Steady State Super-conducting (SST-1) Tokamak is in commissioning stage at Institute for Plasma Research. Vacuum chamber of SST-1 Tokamak consists of 1) Vacuum vessel, an ultra high vacuum (UHV) chamber, 2) Cryostat, a high vacuum (HV) chamber. Cryostat encloses the liquid helium cooled super-conducting magnets (TF and PF), which require the thermal radiation protection against room temperature. Liquid nitrogen (LN2) cooled panels are used to provide thermal shield around super-conducting magnets. During operation, LN 2 panels will be under pressurized condition and its surrounding (cryostat) will be at high vacuum. Hence, LN 2 panels must have very low leak rate. This paper describes an experiment to study the behaviour of the leaks in LN 2 panels during sniffer test and pressure drop test using helium gas

  3. Influence of pressure and temperature on molar volume and retention properties of peptides in ultra-high pressure liquid chromatography.

    Science.gov (United States)

    Fekete, Szabolcs; Horváth, Krisztián; Guillarme, Davy

    2013-10-11

    In this study, pressure induced changes in retention were measured for model peptides possessing molecular weights between ∼1 and ∼4kDa. The goal of the present work was to evaluate if such changes were only attributed to the variation of molar volume and if they could be estimated prior to the experiments, using theoretical models. Restrictor tubing was employed to generate pressures up to 1000bar and experiments were conducted for mobile phase temperatures comprised between 30 and 80°C. As expected, the retention increases significantly with pressure, up to 200% for glucagon at around 1000bar compared to ∼100bar. The obtained data were fitted with a theoretical model and the determination coefficients were excellent (r(2)>0.9992) for the peptides at various temperatures. On the other hand, the pressure induced change in retention was found to be temperature dependent and was more pronounced at 30°C vs. 60 or 80°C. Finally, using the proposed model, it was possible to easily estimate the pressure induced increase in retention for any peptide and mobile phase temperature. This allows to easily estimating the expected change in retention, when increasing the column length under UHPLC conditions. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Pressurized liquid extracts from Spirulina platensis microalga Determination of their antioxidant activity and preliminary analysis by micellar electrokinetic chromatography

    OpenAIRE

    Herrero, Miguel; Ibáñez, Elena; Señorans, F. Javier; Cifuentes, Alejandro

    2004-01-01

    In this work, different extracts from the microalga Spirulina platensis are obtained using pressurized liquid extraction (PLE) and four different solvents (hexane, light petroleum, ethanol andwater). Different extraction temperatures (115 and 170 ◦C) were tested using extraction times ranging from 9 to 15 min. The antioxidant activity of the different extracts is determined by means of an in vitro assay using a free radical method. Moreover, a new and fast method is developed using m...

  5. Thermoelastic properties of liquid Fe-C revealed by sound velocity and density measurements at high pressure

    Science.gov (United States)

    Shimoyama, Yuta; Terasaki, Hidenori; Urakawa, Satoru; Takubo, Yusaku; Kuwabara, Soma; Kishimoto, Shunpachi; Watanuki, Tetsu; Machida, Akihiko; Katayama, Yoshinori; Kondo, Tadashi

    2016-11-01

    Carbon is one of the possible light elements in the cores of the terrestrial planets. The P wave velocity (VP) and density (ρ) are important factors for estimating the chemical composition and physical properties of the core. We simultaneously measured the VP and ρ of Fe-3.5 wt % C up to 3.4 GPa and 1850 K by using ultrasonic pulse-echo method and X-ray absorption methods. The VP of liquid Fe-3.5 wt % C decreased linearly with increasing temperature at constant pressure. The addition of carbon decreased the VP of liquid Fe by about 2% at 3 GPa and 1700 K and decreased the Fe density by about 2% at 2 GPa and 1700 K. The bulk modulus of liquid Fe-C and its pressure (P) and temperature (T) effects were precisely determined from directly measured ρ and VP data to be K0,1700 K = 83.9 GPa, dKT/dP = 5.9(2), and dKT/dT = -0.063 GPa/K. The addition of carbon did not affect the isothermal bulk modulus (KT) of liquid Fe, but it decreased the dK/dT of liquid Fe. In the ρ-VP relationship, VP increases linearly with ρ and can be approximated as VP (m/s) = -6786(506) + 1537(71) × ρ (g/cm3), suggesting that Birch's law is valid for liquid Fe-C at the present P-T conditions. Our results imply that at the conditions of the lunar core, the elastic properties of an Fe-C core are more affected by temperature than those of Fe-S core.

  6. Liquid density of HFE-7200 and HFE-7500 from T = (283 to 363) K at pressures up to 100 MPa

    International Nuclear Information System (INIS)

    Fang, Dan; Li, Ying; Meng, Xianyang; Wu, Jiangtao

    2014-01-01

    Highlights: • Liquid densities are reported for HFE-7200 and HFE-7500 at temperatures from (283 to 363) K, pressures up to 100 MPa. • The expanded uncertainty (k = 2) of density measurement for HFE-7200 and HFE-7500 were 0.04% and 0.03%, respectively. • Modified Tait equations were correlated with the experimental data. • The isobaric thermal expansivity and isothermal compressibility of HFE-7200 and HFE-7500 were calculated. -- Abstract: The liquid densities of HFE-7200 (1-ethoxy-1,1,2,2,3,3,4,4,4-nonafluorobutane, CAS Registry Number: 163702-05-4) and HFE-7500 (3-ethoxyperfluoro(2-methylhexane), CAS Registry Number: 297730-93-9) have been measured over the temperature range from (283 to 363) K and pressures up to 100 MPa by using a high pressure vibrating-tube densimeter. R134a has been used as a reference fluid to validate the densimeter. The uncertainty of each obtained datum was estimated, and the maximum expanded uncertainty with a level of confidence of 0.95 (k = 2) of density measurement for HFE-7200 and HFE-7500 were 0.04% and 0.03%, respectively. The measured liquid densities were correlated with the modified Tait equation and the maximum deviation is less than 0.03%. The isothermal compressibility and isobaric thermal expansivity were also calculated

  7. Extraction efficiency of hydrophilic and lipophilic antioxidants from lyophilized foods using pressurized liquid extraction and manual extraction.

    Science.gov (United States)

    Watanabe, Jun; Oki, Tomoyuki; Takebayashi, Jun; Takano-Ishikawa, Yuko

    2014-09-01

    The efficient extraction of antioxidants from food samples is necessary in order to accurately measure their antioxidant capacities. α-Tocopherol and gallic acid were spiked into samples of 5 lyophilized and pulverized vegetables and fruits (onion, cabbage, Satsuma mandarin orange, pumpkin, and spinach). The lipophilic and hydrophilic antioxidants in the samples were sequentially extracted with a mixed solvent of n-hexane and dichloromethane, and then with acetic acid-acidified aqueous methanol. Duplicate samples were extracted: one set was extracted using an automated pressurized liquid extraction apparatus, and the other set was extracted manually. Spiked α-tocopherol and gallic acid were recovered almost quantitatively in the extracted lipophilic and hydrophilic fractions, respectively, especially when pressurized liquid extraction was used. The expected increase in lipophilic oxygen radical absorbance capacity (L-ORAC) due to spiking with α-tocopherol, and the expected increase in 2,2-diphenyl-1-picrylhydrazyl radical scavenging activities and total polyphenol content due to spiking with gallic acid, were all recovered in high yield. Relatively low recoveries, as reflected in the hydrophilic ORAC (H-ORAC) value, were obtained following spiking with gallic acid, suggesting an interaction between gallic acid and endogenous antioxidants. The H-ORAC values of gallic acid-spiked samples were almost the same as those of postadded (spiked) samples. These results clearly indicate that lipophilic and hydrophilic antioxidants are effectively extracted from lyophilized food, especially when pressurized liquid extraction is used. © 2014 Institute of Food Technologists®

  8. 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.

  9. Ab initio molecular dynamics study of temperature and pressure-dependent infrared dielectric functions of liquid methanol

    Directory of Open Access Journals (Sweden)

    C. C. Wang

    2017-03-01

    Full Text Available The temperature and pressure-dependent dielectric functions of liquids are of great importance to the thermal radiation transfer and the diagnosis and control of fuel combustion. In this work, we apply the state-of-the-art ab initio molecular dynamics (AIMD method to calculate the infrared dielectric functions of liquid methanol at 183–573 K and 0.1–160 MPa in the spectral range 10−4000 cm−1, and study the temperature and pressure effects on the dielectric functions. The AIMD approach is validated by the Infrared Variable Angle Spectroscopic Ellipsometry (IR-VASE experimental measurements at 298 K and 0.1 MPa, and the proposed IR-VASE method is verified by comparison with paper data of distilled water. The results of the AIMD approach agrees well with the experimental values of IR-VASE. The experimental and theoretical analyses indicate that the temperature and pressure exert a noticeable influence on the infrared dielectric functions of liquid methanol. As temperature increases, the average molecular dipole moment decreases. The amplitudes of dominant absorption peaks reduce to almost one half as temperature increases from 183 to 333 K at 0.1 MPa and from 273 to 573 K at 160 MPa. The absorption peaks below 1500 cm–1 show a redshift, while those centered around 3200 cm–1 show a blueshift. Moreover, larger average dipole moments are observed as pressure increases. The amplitudes of dominant absorption peaks increase to almost two times as pressure increases from 1 to 160 MPa at 373 K.

  10. Development of a group contribution method for determination of viscosity of ionic liquids at atmospheric pressure

    DEFF Research Database (Denmark)

    Gharagheizi, Farhad; Ilani-Kashkouli, Poorandokht; Mohammadi, Amir H.

    2012-01-01

    In this study, a wide literature survey has been carried out to collect an extensive set of liquid viscosity data for ionic liquids (ILs). A data set consisting of 1672 viscosity values and comprising 443 ILs was collated from 204 different literature sources. Using this data set, a reliable grou...

  11. Dielectric recovery mechanism of pressurized carbon dioxide at liquid and supercritical phases

    Science.gov (United States)

    Tanoue, Hiroyuki; Furusato, Tomohiro; Imamichi, Takahiro; Ota, Miyuki; Katsuki, Sunao; Akiyama, Hidenori

    2015-09-01

    Estimates of dielectric recovery rates of supercritical (SC) and liquid carbon dioxide (CO2) were derived with focus on highly-repetitive pulsed power switching mediums. Calculated results suggest that recovery time of SC and liquid CO2 are approximately 50 times shorter than that of water and oils. Prior to 10 µs after breakdown, recovery rates in neither SC nor liquid CO2 reached 100%, though the recovery rate in SC CO2 was higher than that of liquid CO2. To examine causes of recovery rate differences, each dielectric recovery process in SC and liquid CO2 was observed by laser shadowgraph technique. These shadowgraph images suggest two factors explaining dielectric recovery rate differences between these medium conditions: 1) thermodynamic property differences between medium conditions, and 2) differences in the low density region recovery mechanism.

  12. A static analytical apparatus for vapour pressures and (vapour + liquid) phase equilibrium measurements with an internal stirrer and view windows

    International Nuclear Information System (INIS)

    Guo, Hao; Gong, Maoqiong; Dong, Xueqiang; Wu, Jianfeng

    2014-01-01

    Highlights: • A new static analytical apparatus for vapour pressures and VLE data was designed. • The {R600a + R245fa} system was selected as a verification system. • Correlation of VLE data was made using PRvdWs and PRHVNRTL model. • Good agreement can be found with the literature data. - Abstract: A new static analytical apparatus for reliable vapour pressures and (vapour + liquid) equilibrium data of small-scale cell (≈150 mL) with internal stirrer and view windows was designed. In this work, the compositions of the phases were analyzed by a gas chromatograph connected on-line with TCD detectors. The operating pressure ranges from (0 to 3000) kPa, and the operating temperature range from (293 to 400) K. Phase equilibrium data for previously reported systems were first measured to test the credibility of the newly developed apparatus. The test included vapour pressure of 1,1,1,3,3-pentafluoropropane (R245fa) and isobutane (R600a), VLE of the (R600a + R245fa) system from T = (293.150 to 343.880) K. The measured VLE data are regressed with thermodynamic models using Peng–Robinson EoS with two different models, viz. the van der Waals mixing rule, and the Huron–Vidal mixing rule utilising the non-random two-liquid activity coefficient model. Thermodynamic consistency testing is also performed for the newly measured experimental data

  13. The equilibrium hydrogen pressure-temperature diagram for the liquid sodium-hydrogen-oxygen system

    International Nuclear Information System (INIS)

    Knights, C.F.; Whittingham, A.C.

    1982-01-01

    The underlying equilibria in the sodium-hydrogen-oxygen system are presented in the form of a completmentary hydrogen equilibrium pressure-temperature diagram, constructed by using published data and supplemented by experimental measurements of hydrogen equilibrium pressures over condensed phases in the system. Possible applications of the equilibrium pressure-temperature phase diagram limitations regarding its use are outlined

  14. Nano-viscosity of supercooled liquid measured by fluorescence correlation spectroscopy: Pressure and temperature dependence and the density scaling

    Science.gov (United States)

    Meier, G.; Gapinski, J.; Ratajczyk, M.; Lettinga, M. P.; Hirtz, K.; Banachowicz, E.; Patkowski, A.

    2018-03-01

    The Stokes-Einstein relation allows us to calculate apparent viscosity experienced by tracers in complex media on the basis of measured self-diffusion coefficients. Such defined nano-viscosity values can be obtained through single particle techniques, like fluorescence correlation spectroscopy (FCS) and particle tracking (PT). In order to perform such measurements, as functions of pressure and temperature, a new sample cell was designed and is described in this work. We show that this cell in combination with a long working distance objective of the confocal microscope can be used for successful FCS, PT, and confocal imaging experiments in broad pressure (0.1-100 MPa) and temperature ranges. The temperature and pressure dependent nano-viscosity of a van der Waals liquid obtained from the translational diffusion coefficient measured in this cell by means of FCS obeys the same scaling as the rotational relaxation and macro-viscosity of the system.

  15. Pressure effect on crystallization of metallic glass Fe72P11C6Al5B4Ga2 alloy with wide supercooled liquid region

    DEFF Research Database (Denmark)

    Jiang, Jianzhong; Olsen, J. S.; Gerward, Leif

    2000-01-01

    The effect of pressure on the crystallization behavior of metallic glass Fe72P11C6Al5B4Ga2 alloy with a wide supercooled liquid region has been investigated by in situ high-pressure and high-temperature x-ray diffraction measurements using synchrotron radiation. In the pressure range from 0 to 2...... mobility and changes of the Gibbs free energy of various phases with pressure. ©2000 American Institute of Physics....

  16. As, Cd, Cr, Ni and Pb pressurized liquid extraction with acetic acid from marine sediment and soil samples

    International Nuclear Information System (INIS)

    Moreda-Pineiro, Jorge; Alonso-Rodriguez, Elia; Lopez-Mahia, Purificacion; Muniategui-Lorenzo, Soledad; Prada-Rodriguez, Dario; Moreda-Pineiro, Antonio; Bermejo-Barrera, Adela; Bermejo-Barrera, Pilar

    2006-01-01

    Rapid leaching procedures by Pressurized Liquid Extraction (PLE) have been developed for As, Cd, Cr, Ni and Pb leaching from environmental matrices (marine sediment and soil samples). The Pressurized Liquid Extraction is completed after 16 min. The released elements by acetic acid Pressurized Liquid Extraction have been evaluated by inductively coupled plasma-optical emission spectrometry. The optimum multi-element leaching conditions when using 5.0 ml stainless steel extraction cells, were: acetic acid concentration 8.0 M, extraction temperature 100 deg. C, pressure 1500 psi, static time 5 min, flush solvent 60%, two extraction steps and 0.50 g of diatomaceous earth as dispersing agent (diatomaceous earth mass/sample mass ratio of 2). Results have showed that high acetic acid concentrations and high extraction temperatures increase the metal leaching efficiency. Limits of detection (between 0.12 and 0.5 μg g -1 ) and repeatability of the over-all procedure (around 6.0%) were assessed. Finally, accuracy was studied by analyzing PACS-2 (marine sediment), GBW-07409 (soil), IRANT-12-1-07 (cambisol soil) and IRANT-12-1-08 (luvisol soil) certified reference materials (CRMs). These certified reference materials offer certified concentrations ranges between 2.9 and 26.2 μg g -1 for As, from 0.068 to 2.85 μg g -1 for Cd, between 26.4 and 90.7 μg g -1 for Cr, from 9.3 to 40.0 μg g -1 for Ni and between 16.3 and 183.0 μg g -1 for Pb. Recoveries after analysis were between 95.7 and 105.1% for As, 96.2% for Cd, 95.2 and 100.6% for Cr, 95.7 and 103% for Ni and 94.2 and 105.5% for Pb

  17. Dose Uniformity of Over-the-Counter Melatonin as Determined by High-Pressure Liquid Chromatography

    National Research Council Canada - National Science Library

    Prazinko, B

    2000-01-01

    .... A liquid chromatograph equipped with a C-18 microbore column was used in conjunction with an autosampler to perform two runs per tablet, while also running intermittent standards on a regular basis...

  18. Chemically reactive species in liquids generated by atmospheric-pressure plasmas and their roles in plasma medicine

    Energy Technology Data Exchange (ETDEWEB)

    Hamaguchi, Satoshi [Center for Atomic and Molecular Technologies, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2013-07-11

    Plasmas whose gas temperatures are close to room temperature may be generated in ambient air or a gas at atmospheric pressure with the use of low-frequency high voltage or low-power radio-frequency (RF) or microwave power applied to electrodes. Such plasmas can serve as a powerful source of free radicals and/or chemically reactive species that arise from atoms and molecules of the ambient gas. Recently use of such plasmas for medical purposes has attracted much attention as they can be implemented in possible medical devices that can cause blood coagulation, heal wounds, facilitate angiogenesis, sterilize surgical devices as well as living tissues without harming healthy cells, and selectively inactivate cancer cells. Especially of interest among reactive species generated by atmospheric-pressure plasmas (APP) are reactive oxygen species (ROS) and reactive nitrogen species (RNS) that are generated in liquid phase. Since most living tissues and cells are immersed in liquids (such as blood or culture media), reactive species generated by APPs in the gas phase are transported to the liquid phase and possibly converted to different types of reactive species therein before causing some influence on the tissues or cells. In this study, the rate equations are solved to evaluate concentrations of various reactive species in pure water that are originated by plasma reactions in atmosphere and possible effects of such species (including ROS/RNS) on living tissues and cells are discussed.

  19. Chemically reactive species in liquids generated by atmospheric-pressure plasmas and their roles in plasma medicine

    International Nuclear Information System (INIS)

    Hamaguchi, Satoshi

    2013-01-01

    Plasmas whose gas temperatures are close to room temperature may be generated in ambient air or a gas at atmospheric pressure with the use of low-frequency high voltage or low-power radio-frequency (RF) or microwave power applied to electrodes. Such plasmas can serve as a powerful source of free radicals and/or chemically reactive species that arise from atoms and molecules of the ambient gas. Recently use of such plasmas for medical purposes has attracted much attention as they can be implemented in possible medical devices that can cause blood coagulation, heal wounds, facilitate angiogenesis, sterilize surgical devices as well as living tissues without harming healthy cells, and selectively inactivate cancer cells. Especially of interest among reactive species generated by atmospheric-pressure plasmas (APP) are reactive oxygen species (ROS) and reactive nitrogen species (RNS) that are generated in liquid phase. Since most living tissues and cells are immersed in liquids (such as blood or culture media), reactive species generated by APPs in the gas phase are transported to the liquid phase and possibly converted to different types of reactive species therein before causing some influence on the tissues or cells. In this study, the rate equations are solved to evaluate concentrations of various reactive species in pure water that are originated by plasma reactions in atmosphere and possible effects of such species (including ROS/RNS) on living tissues and cells are discussed

  20. Solitary traveling wave solutions of pressure equation of bubbly liquids with examination for viscosity and heat transfer

    Science.gov (United States)

    Khater, Mostafa M. A.; Seadawy, Aly R.; Lu, Dianchen

    2018-03-01

    In this research, we investigate one of the most popular model in nature and also industrial which is the pressure equation of bubbly liquids with examination for viscosity and heat transfer which has many application in nature and engineering. Understanding the physical meaning of exact and solitary traveling wave solutions for this equation gives the researchers in this field a great clear vision of the pressure waves in a mixture liquid and gas bubbles taking into consideration the viscosity of liquid and the heat transfer and also dynamics of contrast agents in the blood flow at ultrasonic researches. To achieve our goal, we apply three different methods which are extended tanh-function method, extended simple equation method and a new auxiliary equation method on this equation. We obtained exact and solitary traveling wave solutions and we also discuss the similarity and difference between these three method and make a comparison between results that we obtained with another results that obtained with the different researchers using different methods. All of these results and discussion explained the fact that our new auxiliary equation method is considered to be the most general, powerful and the most result-oriented. These kinds of solutions and discussion allow for the understanding of the phenomenon and its intrinsic properties as well as the ease of way of application and its applicability to other phenomena.

  1. Tanker for the transport of very low temperature liquids at atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Messer, E S

    1968-02-08

    This tanker for the transport of very low temperature liquids, especially liquefied methane or natural gas, has a large capacity reservoir insulated on the outside. A second reservoir in the bottom of the hull, below the main reservoir, collects liquid leaking out from the main reservoir and is equipped with a drain pipe. The pipe serving to fill and to empty the main reservoir passes through this second reservoir. (4 claims)

  2. Separation of toluene from cyclic hydrocarbons using 1-butyl-3-methylimidazolium methylsulfate ionic liquid at T = 298.15 K and atmospheric pressure

    International Nuclear Information System (INIS)

    Dominguez, Irene; Calvar, Noelia; Gomez, Elena; Dominguez, Angeles

    2011-01-01

    Highlights: → [BMim][MSO 4 ] was studied as solvent to extract toluene from cyclic hydrocarbons. → (Liquid + liquid) equilibrium data were measured at 298.15K and atmospheric pressure. → Selectivity and solute distribution ratio were obtained and compared with literature. → Experimental data were satisfactorily correlated using NRTL and UNIQUAC models. → [BMim][MSO 4 ] can be used as solvent for the studied (liquid + liquid) extraction. - Abstract: In this paper the extraction of toluene from cyclic hydrocarbons (cyclohexane, or methylcyclohexane, or cyclooctane, or cyclohexene) was analyzed by liquid extraction with 1-butyl-3-methylimidazolium methylsulfate ionic liquid, [BMim][MSO 4 ], as solvent. The experimental (liquid + liquid) equilibrium (LLE) data were determined at T = 298.15 K and atmospheric pressure. Solubility curves were obtained by the cloud point method and tie-line compositions were determined by density measurement. An analysis of the influence of different cyclic hydrocarbons on the extraction was performed. The effectiveness of the extraction of toluene from cyclic hydrocarbons was evaluated by means of the solute distribution ratio and selectivity values. The degree of consistency of the experimental LLE data was ascertained using the Othmer-Tobias and Hand equations. The experimental data for the (liquid + liquid) equilibria of the ternary systems were correlated with the Non-Random Two-Liquid (NRTL) and UNIversal QUAsi-Chemical (UNIQUAC) thermodynamic models.

  3. Parallel artificial liquid membrane extraction as an efficient tool for removal of phospholipids from human plasma

    DEFF Research Database (Denmark)

    Ask, Kristine Skoglund; Bardakci, Turgay; Parmer, Marthe Petrine

    2016-01-01

    Generic Parallel Artificial Liquid Membrane Extraction (PALME) methods for non-polar basic and non-polar acidic drugs from human plasma were investigated with respect to phospholipid removal. In both cases, extractions in 96-well format were performed from plasma (125μL), through 4μL organic...

  4. 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

  5. Ionic Liquid (1-Butyl-3-Metylimidazolium Methane Sulphonate Corrosion and Energy Analysis for High Pressure CO2 Absorption Process

    Directory of Open Access Journals (Sweden)

    Aqeel Ahmad Taimoor

    2018-05-01

    Full Text Available This study explores the possible use of ionic liquids as a solvent in a commercial high-pressure CO2 removal process, to gain environmental and energy benefits. There are two main constraints in realizing this: ionic liquids can be corrosive, specifically when mixed with a water/amine solution with dissolved O2 & CO2; and CO2 absorption within this process is not very well understood. Therefore, scavenging CO2 to ppm levels from process gas comes with several risks. We used 1-butyl-3-methylimidazoium methane sulphonate [bmim][MS] as an ionic liquid because of its high corrosiveness (due to its acidic nature to estimate the ranges of expected corrosion in the process. TAFEL technique was used to determine these rates. Further, the process was simulated based on the conventional absorption–desorption process using ASPEN HYSYS v 8.6. After preliminary model validation with the amine solution, [bmim][MS] was modeled based on the properties found in the literature. The energy comparison was then provided and the optimum ratio of the ionic liquid/amine solution was calculated.

  6. Phytochemical composition of fractions isolated from ten Salvia species by supercritical carbon dioxide and pressurized liquid extraction methods.

    Science.gov (United States)

    Šulniūtė, Vaida; Pukalskas, Audrius; Venskutonis, Petras Rimantas

    2017-06-01

    Ten Salvia species, S. amplexicaulis, S. austriaca, S. forsskaolii S. glutinosa, S. nemorosa, S. officinalis, S. pratensis, S. sclarea, S. stepposa and S. verticillata were fractionated using supercritical carbon dioxide and pressurized liquid (ethanol and water) extractions. Fifteen phytochemicals were identified using commercial standards (some other compounds were identified tentatively), 11 of them were quantified by ultra high pressure chromatography (UPLC) with quadruple and time-of-flight mass spectrometry (Q/TOF, TQ-S). Lipophilic CO 2 extracts were rich in tocopherols (2.36-10.07mg/g), while rosmarinic acid was dominating compound (up to 30mg/g) in ethanolic extracts. Apigenin-7-O-β-d-glucuronide, caffeic and carnosic acids were quantitatively important phytochemicals in the majority other Salvia spp. Antioxidatively active constituents were determined by using on-line high-performance liquid chromatography (HPLC) analysis combined with 2,2'-diphenyl-1-picrylhydrazyl (DPPH) assay (HPLC-DPPH). Development of high pressure isolation process and comprehensive characterisation of phytochemicals in Salvia spp. may serve for their wider applications in functional foods and nutraceuticals. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Standard practice for examination of liquid-Filled atmospheric and Low-pressure metal storage tanks using acoustic emission

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This practice covers guidelines for acoustic emission (AE) examinations of new and in-service aboveground storage tanks of the type used for storage of liquids. 1.2 This practice will detect acoustic emission in areas of sensor coverage that are stressed during the course of the examination. For flat-bottom tanks these areas will generally include the sidewalls (and roof if pressure is applied above the liquid level). The examination may not detect flaws on the bottom of flat-bottom tanks unless sensors are located on the bottom. 1.3 This practice may require that the tank experience a load that is greater than that encountered in normal use. The normal contents of the tank can usually be used for applying this load. 1.4 This practice is not valid for tanks that will be operated at a pressure greater than the examination pressure. 1.5 It is not necessary to drain or clean the tank before performing this examination. 1.6 This practice applies to tanks made of carbon steel, stainless steel, aluminum and oth...

  8. Influence of wall ribs on the thermal stratification and self-pressurization in a cryogenic liquid tank

    International Nuclear Information System (INIS)

    Fu, Juan; Sunden, Bengt; Chen, Xiaoqian

    2014-01-01

    Self-pressurization in a cylindrical ribbed tank which is partially filled with liquid hydrogen is investigated numerically under different rib spacing-to-height ratios. The Volume of Fluid (VOF) method is employed as well as a phase change model. Appropriate models are incorporated into the Ansys Fluent by the user-defined functions to carry out the computations. The ribbed surface is modeled as a finned surface and a conjugate transient heat transfer problem is formulated for predicting fluid flow currents and heat transfer. The effect of rib material and shapes is also studied. Numerical results indicate that the pressure rise can be reduced by ribs mounted on the tank wall. This phenomenon is more pronounced as the rib spacing-to-height ratio is reduced. A vortex is observed in the downstream region of each rib when the spacing-to-height has a relatively high value. Evaporation occurs as time elapses due to heat accumulation at the rib surfaces. Pressure starts to rise later with high thermal conductivity ribs and becomes higher with low thermal conductivity ribs when the ribs are of identical configuration in geometry. The final pressure rise seems to be monotonically versus increasing time. The semicircular ribs perform better than rectangular ones in control of the pressure rise and thermal stratification for identical cross sectional area and if the locations are kept the same

  9. Effect Of Compaction Pressure And Sintering Temperature On The Liquid Phase Sintering Behavior Of Al-Cu-Zn Alloy

    Directory of Open Access Journals (Sweden)

    Lee S.H.

    2015-06-01

    Full Text Available The liquid phase sintering characteristics of Al-Cu-Zn alloy were investigated with respect to various powder metallurgy processing conditions. Powders of each alloying elements were blended to form Al-6Cu-5Zn composition and compacted with pressures of 200, 400, and 600 MPa. The sintering process was performed at various temperatures of 410, 560, and 615°C in N2 gas atmosphere. Density and micro-Vickers hardness measurements were conducted at different processing stages, and transverse rupture strength of sintered materials was examined for each condition, respectively. The microstructure was characterized using optical microscope and scanning electron microscopy. The effect of Zn addition on the liquid phase sintering behavior during P/M process of the Al-Cu-Zn alloy was also discussed in detail.

  10. Influences of non-uniform pressure field outside bubbles on the propagation of acoustic waves in dilute bubbly liquids.

    Science.gov (United States)

    Zhang, Yuning; Du, Xiaoze

    2015-09-01

    Predictions of the propagation of the acoustic waves in bubbly liquids is of great importance for bubble dynamics and related applications (e.g. sonochemistry, sonochemical reactor design, biomedical engineering). In the present paper, an approach for modeling the propagation of the acoustic waves in dilute bubbly liquids is proposed through considering the non-uniform pressure field outside the bubbles. This approach is validated through comparing with available experimental data in the literature. Comparing with the previous models, our approach mainly improves the predictions of the attenuation of acoustic waves in the regions with large kR0 (k is the wave number and R0 is the equilibrium bubble radius). Stability of the oscillating bubbles under acoustic excitation are also quantitatively discussed based on the analytical solution. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. 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.

  12. State-of-the-Art of Extreme Pressure Lubrication Realized with the High Thermal Diffusivity of Liquid Metal.

    Science.gov (United States)

    Li, Haijiang; Tian, Pengyi; Lu, Hongyu; Jia, Wenpeng; Du, Haodong; Zhang, Xiangjun; Li, Qunyang; Tian, Yu

    2017-02-15

    Sliding between two objects under very high load generally involves direct solid-solid contact at molecular/atomic level, the mechanism of which is far from clearly disclosed yet. Those microscopic solid-solid contacts could easily lead to local melting of rough surfaces. At extreme conditions, this local melting could propagate to the seizure and welding of the entire interface. Traditionally, the microscopic solid-solid contact is alleviated by various lubricants and additives based on their improved mechanical properties. In this work, we realized the state-of-the-art of extreme pressure lubrication by utilizing the high thermal diffusivity of liquid metal, 2 orders of magnitude higher than general organic lubricants. The extreme pressure lubrication property of gallium based liquid metal (GBLM) was compared with gear oil and poly-α-olefin in a four-ball test. The liquid metal lubricates very well at an extremely high load (10 kN, the maximum capability of a four-ball tester) at a rotation speed of 1800 rpm for a duration of several minutes, much better than traditional organic lubricants which typically break down within seconds at a load of a few kN. Our comparative experiments and analysis showed that this superextreme pressure lubrication capability of GBLM was attributed to the synergetic effect of the ultrafast heat dissipation of GBLM and the low friction coefficient of FeGa 3 tribo-film. The present work demonstrated a novel way of improving lubrication capability by enhancing the lubricant thermal properties, which might lead to mechanical systems with much higher reliability.

  13. Ionization of liquids

    International Nuclear Information System (INIS)

    Gregg, E.C.; Bakale, G.

    1976-01-01

    Application of pulsed-conductivity techniques to ionization phenomena in liquids has yielded new results on electron transport and electron reactions in nonpolar liquids which we have extrapolated to biological systems to develop a novel model of direct radiation damage to mammalian cells that involves the unsolvated electron as the key reactant. Among these new results are electron attachment rate constants of thirty-five substituted nitrobenzene compounds measured in nonpolar solvents which when combined with product anion lifetimes are correlated with cellular radiosensitization efficiencies. From this study we found that electron attachment rates are dependent upon the electron mobility in the solvents and upon the dipole moment of the electron-accepting nitrobenzene compounds. The model also drawn upon energy-dependent electron attachment rates which we have measured in cryogenic liquids, and we have measured in the same solvents associative detachment rate constants and electron momentum transfer cross sections. In addition to these studies of electronic processes in liquids, we have measured ion mobilities of lecithin and chlorophyll in nonpolar solvents and conclude that these solutes form inverse micelles under certain conditions. Formation of these micelles permits electron transport through the lipid micellar walls and electron attachment to electron-accepting polar solutes inside the lipid vesicles to be studied

  14. High pressure liquid chromatographic analysis of the main pungent principles of solar dried West Indian ginger (Zingiber officinale Roscoe)

    Energy Technology Data Exchange (ETDEWEB)

    Balladin, D.A.; Headley, O. [University of the West Indies, Cave Hill Campus, St. Michael, Barbados (West Indies). Centre for Resource Management and Environmental Studies; Chang-Yen, I. [University of the West Indies, St. Augustine Campus, Trinidad (West Indies). Faculty of Agriculture and Natural Sciences; McGaw, D.R. [University of the West Indies, St. Augustine Campus, Trinidad (West Indies). Dept. of Chemical Engineering

    1998-12-31

    The main pungent principles of West Indian ginger (Zingiber officinale Roscoe) were quantified and qualified using High Pressure Liquid Chromatography. This procedure was used to evaluate the pungency profile of fresh, solar dried and solar dried/steam distilled ginger rhizomes. In this investigation, the total oleoresin extracted was in the ratio [20: 1: 2] for [fresh ginger: solar dried: solar dried/steam distilled ginger rhizomes] with respect to the [6]-gingerol content. This simple isocratic HPLC method can be used to investigate the pungency profile of the extracted oleoresin from the ginger rhizomes. (author)

  15. High-Pressure Phase Equilibria in Systems Containing CO2 and Ionic Liquid of the [Cnmim][Tf2N] Type

    OpenAIRE

    Sedláková, Z. (Zuzana); Wagner, Z. (Zdeněk)

    2012-01-01

    In this review, we present a comparison of the high-pressure phase behaviour of binary systems constituted of CO2 and ionic liquids of the [Cn(m)mim][Tf2N] type. The comparative study shows that the solubility of CO2 in ionic liquids of the [Cnmim][Tf2N] type generally increases with increasing pressure and decreasing temperature, but some peculiarities have been observed. The solubility of CO2 in ionic liquid solvents was correlated using the Soave–Redlich–Kwong equation of state. The result...

  16. Pressure evolution of the high-frequency sound velocity in liquid water

    International Nuclear Information System (INIS)

    Krisch, M.; Sette, F.; D'Astuto, M.; Lorenzen, M.; Mermet, A.; Monaco, G.; Verbeni, R.; Loubeyre, P.; Le Toullec, R.; Ruocco, G.; Cunsolo, A.

    2002-01-01

    The high-frequency sound velocity v ∞ of liquid water has been determined to densities of 1.37 g/cm 3 by inelastic x-ray scattering. In comparison to the hydrodynamic sound velocity v 0 , the increase of v ∞ with density is substantially less pronounced, indicating that, at high density, the hydrogen-bond network is decreasingly relevant to the physical properties of liquid water. Furthermore, we observe an anomaly in v ∞ at densities around 1.12 g/cm 3 , contrasting the smooth density evolution of v 0

  17. Home-made online hyphenation of pressurized liquid extraction, turbulent flow chromatography, and high performance liquid chromatography, Cistanche deserticola as a case study.

    Science.gov (United States)

    Song, Qingqing; Li, Jun; Liu, Xiao; Zhang, Yuan; Guo, Liping; Jiang, Yong; Song, Yuelin; Tu, Pengfei

    2016-03-18

    Incompatibility between the conventional pressurized liquid extraction (PLE) devices and high performance liquid chromatography (HPLC) extensively hinders direct and green chemical analysis of herbal materials. Herein, a facile PLE module was configured, and then it was online hyphenated with HPLC via a turbulent flow chromatography (TFC) column. Regarding PLE module, a long PEEK tube (0.13 × 1000 mm) was employed to generate desired pressure (approximately 13.0 MPa) when warm acidic water (70 °C) was delivered as extraction solvent at a high flow rate (2.5 mL/min), and a hollow guard column (3.0 × 4.0 mm) was implemented to hold crude materials. Effluent was collected from the outlet of PEEK tube, concentrated, and subjected onto HPLC coupled with hybrid ion trap-time of flight mass spectrometer to assess the extraction efficiency and also to profile the chemical composition of Cistanche deserticola (CD) that is honored as "Ginseng of the desert". Afterwards, a TFC column was introduced to accomplish online transmission of low molecule weight components from PLE module to HPLC coupled with diode array detection, and two electronic 6-port/2-channel valves were in charge of alternating the whole system between extraction (0-3.0 min) and elution (3.0-35.0 min) phases. Quantitative method was developed and validated for simultaneous determination of eight primary phenylethanoid glycosides in CD using online PLE-TFC-HPLC. All findings demonstrated that the home-made platform is advantageous at direct chemical analysis, as well as time-, solvent-, and material-savings, suggesting a robust tool for chemical fingerprinting of herbs. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Dynamic high pressure induced strong and weak hydrogen bonds enhanced by pre-resonance stimulated Raman scattering in liquid water.

    Science.gov (United States)

    Wang, Shenghan; Fang, Wenhui; Li, Fabing; Gong, Nan; Li, Zhanlong; Li, Zuowei; Sun, Chenglin; Men, Zhiwei

    2017-12-11

    355 nm pulsed laser is employed to excite pre-resonance forward stimulated Raman scattering (FSRS) of liquid water at ambient temperature. Due to the shockwave induced dynamic high pressure, the obtained Raman spectra begin to exhibit double peaks distribution at 3318 and 3373 cm -1 with the input energy of 17 mJ,which correspond with OH stretching vibration with strong and weak hydrogen (H) bonds. With laser energy rising from 17 to 27 mJ, the Stokes line at 3318 cm -1 shifts to 3255 and 3230 cm -1 because of the high pressure being enlarged. When the energy is up to 32 mJ, only 3373 cm -1 peak exists. The strong and weak H bond exhibit quite different energy dependent behaviors.

  19. Critical Current Properties of HTS Twisted Stacked-Tape Cable in Subcooled- and Pressurized-Liquid Nitrogen

    International Nuclear Information System (INIS)

    Tomita, M; Suzuki, K; Fukumoto, Y; Ishihara, A; Akasaka, T; Kobayashi, Y; Maeda, A; Takayasu, M

    2015-01-01

    A 2 m length Twisted Stacked-Tape Cable (TSTC) conductor which was fabricated by 32-YBCO-tapes (4 mm width) with a 200 mm twist pitch was investigated at various temperatures near 77 K in subcooled- and pressurized-liquid nitrogen. The critical current of the TSTC cable which was 1.45 kA at 77 K measured from 64 K to 85 K by controlling the equilibrium vapor pressure of nitrogen bath and were varied from 3.65 kA at 64 K to 0.42 kA at 85 K. The temperature dependence of cables’ critical current agrees with that of the 4 mm width YBCO tape. These results are encouraging for applications of a compact Twisted Stacked-Tape Cable application in railway systems. (paper)

  20. Analysis of endocrine disruptor compounds in marine sediments by in cell clean up-pressurized liquid extraction-liquid chromatography tandem mass spectrometry determination.

    Science.gov (United States)

    Salgueiro-González, N; Turnes-Carou, I; Muniategui-Lorenzo, S; López-Mahía, P; Prada-Rodríguez, D

    2014-12-10

    A less time-, solvent- and sorbent-consuming analytical methodology for the determination of bisphenol A and alkylphenols (4-tert-octylphenol, 4-octylphenol, 4-n-nonylphenol, nonylphenol) in marine sediment was developed and validated. The method was based on selective pressurized liquid extraction (SPLE) with a simultaneous in cell clean up combined with liquid chromatography-electrospray ionization tandem mass spectrometry in negative mode (LC-ESI-MS/MS). The SPLE extraction conditions were optimized by a Plackett-Burman design followed by a central composite design. Quantitation was performed by standard addition curves in order to correct matrix effects. The analytical features of the method were satisfactory: relative recoveries varied between 94 and 100% and repeatability and intermediate precision were <6% for all compounds. Uncertainty assessment of measurement was estimated on the basis of an in-house validation according to EURACHEM/CITAC guide. Quantitation limits of the method (MQL) ranged between 0.17 (4-n-nonylphenol) and 4.01 ng g(-1) dry weight (nonylphenol). Sensitivity, selectivity, automaticity and fastness are the main advantages of this green methodology. As an application, marine sediment samples from Galicia coast (NW of Spain) were analysed. Nonylphenol and 4-tert-octylphenol were measured in all samples at concentrations between 20.1 and 1409 ng g(-1) dry weight, respectively. Sediment toxicity was estimated and no risk to aquatic biota was found. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Liquid Hydrogen Regulated Low Pressure High Flow Pneumatic Panel AFT Arrow Analysis

    Science.gov (United States)

    Jones, Kelley, M.

    2013-01-01

    Project Definition: Design a high flow pneumatic regulation panel to be used with helium and hydrogen. The panel will have two circuits, one for gaseous helium (GHe) supplied from the GHe Movable Storage Units (MSUs) and one for gaseous hydrogen (GH2) supplied from an existing GH2 Fill Panel. The helium will supply three legs; to existing panels and on the higher pressure leg and Simulated Flight Tanks (SFTs) for the lower pressure legs. The hydrogen line will pressurize a 33,000 gallon vacuum jacketed vessel.

  2. Non-Fermi liquid behaviour in UCoAl: Pressure variations

    Czech Academy of Sciences Publication Activity Database

    Havela, L.; Honda, F.; Griveau, J.C.; Andreev, Alexander V.; Kolomiets, A.; Sechovský, V.

    408-412, - (2006), s. 1316-1319 ISSN 0925-8388 R&D Projects: GA ČR(CZ) GA202/04/1103; GA MŠk(CZ) ME 512 Institutional research plan: CEZ:AV0Z10100520 Keywords : non-Fermi liquid * band metamagnetism Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.250, year: 2006

  3. Modeling and experiments with low-frequency pressure wave propagation in liquid-filled, flexible tubes

    DEFF Research Database (Denmark)

    Bjelland, C; Bjarnø, Leif

    1992-01-01

    relations and frequency-dependent attenuation. A 12-m-long, liquid-filled tube with interior stress members and connectors in each end is hanging vertically from an upper fixture. The lower end connector is excited by a power vibrator to generate the relevant wave modes. Measurements with reference...

  4. Chemical equilibrium calculations for the high pressure and temperature dissociation of liquid nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, D.C.; Ree, F.H.

    1987-07-01

    Calculations are reported for the equation-of-state properties of shock-compressed liquid nitrogen. The statistical mechanical, chemical equilibrium calculations, which allow for the simultaneous presence of both the diatomic and monatomic forms of nitrogen, show good agreement with recent dynamic experiments.

  5. Chemical equilibrium calculations for the high pressure and temperature dissociation of liquid nitrogen

    International Nuclear Information System (INIS)

    Hamilton, D.C.; Ree, F.H.

    1987-07-01

    Calculations are reported for the equation-of-state properties of shock-compressed liquid nitrogen. The statistical mechanical, chemical equilibrium calculations, which allow for the simultaneous presence of both the diatomic and monatomic forms of nitrogen, show good agreement with recent dynamic experiments

  6. On the estimation of threshold pressures in infiltration of liquid metals into particle preforms

    International Nuclear Information System (INIS)

    Molina, J.M.; Prieto, R.; Duarte, M.; Narciso, J.; Louis, E.

    2008-01-01

    Threshold pressures for infiltration of different metals into preforms of ceramic particles of various nature and morphology were experimentally determined and the results compared with those estimated by using the specific particle surface areas derived from laser diffraction and gas adsorption. Whilst laser diffraction provides an under estimation of the areas involved in the infiltration experiments, and thus of threshold pressures, gas adsorption offers reasonable values for particles that are regular and free of nanostructured surfaces

  7. Analysis of liquid relief valves opening demand during pressure increase abnormal scenarios at Embalse nuclear power plant

    International Nuclear Information System (INIS)

    Bedrossian, Gustavo C.; Gersberg, Sara

    2000-01-01

    Two hypothetical scenarios have been analyzed where, after an initiating event, Embalse nuclear power plant primary heat transport system could undergo a pressure increase. These abnormal events are a loss of feedwater to the steam generators and a loss of Class IV power supply with Class III restoration. This analysis focuses on primary system liquid relief valves action, specially on their opening demand. Calculation results show that even when these valves are expected to open during the transient, primary system maximum allowable pressure would not be exceeded if they failed to open. System response was also studied in case that one of these relief valves did not close once primary system pressure decreases. For the scenario of loss of feedwater to steam generators, if the degasser-condenser could not be bottled-up, Emergency Cooling Injection conditions would be reached due to a continuos loss of coolant. In case of loss of Class IV -and assuming degasser-condenser bottling-up as service water would not be available- it was observed that primary system should remain pressurized, and with core cooled by thermo siphoning mechanism. (author)

  8. Measurements of the osmotic pressure in liquid mixtures of 3He and 4He near the lambda line and tricritical point

    International Nuclear Information System (INIS)

    Gearhart, C.A. Jr.

    1977-01-01

    Values of the concentration susceptibility (par. deltax/par. deltaΔ)/sub T,P/ near the lambda line and tricritical point in liquid mixtures of 3He and 4 He were calculated from measurements of osmotic pressure differences. Measurements were made by inducing a small 3 He mole fraction difference Δx between two chambrs separated by a pressure transducer, and measuring the resulting osmotic pressure difference as a function of temperature

  9. Evaluation of the flow of a liquid during the processing of the curves of the reduction of pressure of unfinished wells in cracked layers

    Energy Technology Data Exchange (ETDEWEB)

    Belov, V.V.; Makarenko, A.M.; Saakov, S.A.

    1979-01-01

    The difference in the behavior of face pressures after the abandonement of real and hypothetical wells is explained by the process of the entrance of the liquid into the shaft. The value of these differences affects the accuracy of the processing of the curves of the reduction of pressure. For the study of this phenomenon, industrial investigations were carried out in gusher wells in the El'darovo platform, found in the territory of the Chechen Ingush ASSR. It was established, that after closing the wells, the layer liquid continues to enter into the shaft of the well and the greatest effect on the growth of the face pressure of that inflow proves to happen immediately after the closing of the well. A method is suggested for the processing of the curves of the reduction of pressure, taking into consideration the inflow of the liquid into the shaft after the abandonement of the well.

  10. Molecular design for nonpolar chiral-axial quadratic nonlinear optics

    Science.gov (United States)

    Wiggers, Gregory A.

    In this thesis the hyperpolarizability of various multi-dimensional molecules is studied theoretically/computationally, with particular focus on the second-rank Kleinman-disallowed (KD) component of the hyperpolarizability. This component, which transforms as a second-rank traceless symmetric tensor, could be utilized in certain chiral-axial molecular alignment schemes to produce a bulk response. Nonpolar chiral-axial systems have been proposed in contrast to polar media, which utilize the vector component of the molecular hyperpolarizability and require parallel alignment of the molecular dipoles. Such parallel alignment of dipoles must be "frozen in" in order to overcome the natural tendency for dipoles to align anti-parallel. This limits the density of chromophores that can be loaded into a polar material. Nonpolar materials do not have such limits in theory. The two geometric classes of molecules that can most easily be incorporated into nonpolar chiral-uniaxial materials are propeller-shaped (C3 or D3 symmetry) and Λ-shaped (C2v symmetry). This work describes efforts to design molecules within these classes that would be suitable for bulk NLO materials. The sum-over-states (SOS) expression is used to model the molecular hyperpolarizability, and quantum chemical calculations, along with linear absorption data (when available) provide the necessary parameters to evaluate truncated forms of the SOS expression. A host of chemical and geometric modifications will be considered in order to elucidate important structure/function relationships. Also, the SOS model will be tested in some cases when experimental measurements (via Kleinman-disallowed hyper-Rayleigh scattering) are available. While a majority of this work focuses on multi-dimensional molecules, a small section deals with the question of optimizing the hyperpolarizability of a one-dimensional system. It is suggested that the recently-proposed idea of "modulated conjugation" as a means for improving

  11. Stability of Anthocyanins from Red Grape Skins under Pressurized Liquid Extraction and Ultrasound-Assisted Extraction Conditions

    Directory of Open Access Journals (Sweden)

    Ali Liazid

    2014-12-01

    Full Text Available The stability of anthocyanins from grape skins after applying different extraction techniques has been determined. The following compounds, previously extracted from real samples, were assessed: delphinidin 3-glucoside, cyanidin 3-glucoside, petunidin 3-glucoside, peonidin 3-glucoside, malvidin 3-glucoside, peonidin 3-acetylglucoside, malvidin 3-acetylglucoside, malvidin 3-caffeoylglucoside, petunidin 3-p-coumaroylglucoside and malvidin 3-p-coumaroylglucoside (trans. The techniques used were ultrasound-assisted extraction and pressurized liquid extraction. In ultrasound-assisted extraction, temperatures up to 75 °C can be applied without degradation of the aforementioned compounds. In pressurized liquid extraction the anthocyanins were found to be stable up to 100 °C. The relative stabilities of both the glycosidic and acylated forms were evaluated. Acylated derivatives were more stable than non-acylated forms. The differences between the two groups of compounds became more marked on working at higher temperatures and on using extraction techniques with higher levels of oxygen in the extraction media.

  12. Comparison of differential pressure model based on flow regime for gas/liquid two-phase flow

    International Nuclear Information System (INIS)

    Dong, F; Zhang, F S; Li, W; Tan, C

    2009-01-01

    Gas/liquid two-phase flow in horizontal pipe is very common in many industry processes, because of the complexity and variability, the real-time parameter measurement of two-phase flow, such as the measurement of flow regime and flow rate, becomes a difficult issue in the field of engineering and science. The flow regime recognition plays a fundamental role in gas/liquid two-phase flow measurement, other parameters of two-phase flow can be measured more easily and correctly based on the correct flow regime recognition result. A multi-sensor system is introduced to make the flow regime recognition and the mass flow rate measurement. The fusion system is consisted of temperature sensor, pressure sensor, cross-section information system and v-cone flow meter. After the flow regime recognition by cross-section information system, comparison of four typical differential pressure (DP) models is discussed based on the DP signal of v-cone flow meter. Eventually, an optimum DP model has been chosen for each flow regime. The experiment result of mass flow rate measurement shows it is efficient to classify the DP models by flow regime.

  13. Novel determination of polychlorinated naphthalenes in water by liquid chromatography-mass spectrometry with atmospheric pressure photoionization.

    Science.gov (United States)

    Moukas, Athanasios I; Thomaidis, Nikolaos S; Calokerinos, Antony C

    2016-01-01

    This study presents the development, optimization, and validation of a novel method for the determination of polychlorinated naphthalenes (PCNs) by liquid chromatography-atmospheric pressure photoionization (APPI), using toluene as dopant. The mass spectra of PCN 52, 54, 66, 67, 73, and 75 were recorded in negative ionization. The base ions corresponded to [M-Cl+O](-), where M is the analyte molecule. A strategy, which includes designs of experiments, for the development, the evaluation, and the optimization of the LC-APPI-MS/MS methods is also described. Finally, a highly sensitive method with low instrumental limits of detection (LoDs), ranging from 0.8 pg for PCN 75 to 16 pg for PCN 54 on column, was validated. A Thermo Hypersil Green PAH (100 mm × 2.1 mm, 3 μm) column was used with acetonitrile/water/methanol as mobile phase. The method was applied for the determination of the selected PCNs in surface and tap water samples. A simple liquid-liquid extraction method for the extraction of PCNs from water samples was used. Method LoQs ranged from 29 ng L(-1), for PCN 73, to 63 ng L(-1), for PCN 54, and the recoveries ranged from 97 to 99%, for all congeners. This is the first LC-APPI-MS/MS method for the determination of PCNs in water samples.

  14. Optimization of pressurized liquid extraction by response surface methodology of Goji berry (Lycium barbarum L.) phenolic bioactive compounds.

    Science.gov (United States)

    Tripodo, Giusy; Ibáñez, Elena; Cifuentes, Alejandro; Gilbert-López, Bienvenida; Fanali, Chiara

    2018-01-03

    Pressurized liquid extraction (PLE) has been used for the first time in this work to extract phenolic compounds from Goji berries according to a multilevel factorial design using response surface methodology. The global yield (% w/dw, weight/dry-weight), total phenolic content (TPC), total flavonoid (TF) and antioxidant activity (determined via ABTS assay, expressed as TEAC value) were used as response variables to study the effects of temperature (50-180°C) and green solvent composition (mixtures of ethanol/water). Phenolic compounds characterization was performed by high performance liquid chromatography-diode array detector-tandem mass spectrometry (HPLC-DAD-MS/MS). The optimum PLE conditions predicted by the model were as follows: 180°C and 86% ethanol in water with a good desirability value of 0.815. The predicted conditions were confirmed experimentally and once the experimental design was validated for commercial fruit samples, the PLE extraction of phenolic compounds from three different varieties of fruit samples (Selvatico mongolo, Bigol, and Polonia) was performed. Nine phenolic compounds were tentatively identified in these extracts, including phenolic acids and their derivatives, and flavonols. The optimized PLE conditions were compared to a conventional solid-liquid extraction, demonstrating that PLE is a useful alternative to extract phenolic compounds from Goji berry. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. An equation of state for high pressure-temperature liquids (RTpress) with application to MgSiO3 melt

    Science.gov (United States)

    Wolf, Aaron S.; Bower, Dan J.

    2018-05-01

    The thermophysical properties of molten silicates at extreme conditions are crucial for understanding the early evolution of Earth and other massive rocky planets, which is marked by giant impacts capable of producing deep magma oceans. Cooling and crystallization of molten mantles are sensitive to the densities and adiabatic profiles of high-pressure molten silicates, demanding accurate Equation of State (EOS) models to predict the early evolution of planetary interiors. Unfortunately, EOS modeling for liquids at high P-T conditions is difficult due to constantly evolving liquid structure. The Rosenfeld-Tarazona (RT) model provides a physically sensible and accurate description of liquids but is limited to constant volume heating paths (Rosenfeld and Tarazona, 1998). We develop a high P-T EOS for liquids, called RTpress, which uses a generalized Rosenfeld-Tarazona model as a thermal perturbation to isothermal and adiabatic reference compression curves. This approach provides a thermodynamically consistent EOS which remains accurate over a large P-T range and depends on a limited number of physically meaningful parameters that can be determined empirically from either simulated or experimental datasets. As a first application, we model MgSiO3 melt representing a simplified rocky mantle chemistry. The model parameters are fitted to the MD simulations of both Spera et al. (2011) and de Koker and Stixrude (2009), recovering pressures, volumes, and internal energies to within 0.6 GPa, 0.1 Å3 , and 6 meV per atom on average (for the higher resolution data set), as well as accurately predicting liquid densities and temperatures from shock-wave experiments on MgSiO3 glass. The fitted EOS is used to determine adiabatic thermal profiles, revealing the approximate thermal structure of a fully molten magma ocean like that of the early Earth. These adiabats, which are in strong agreement for both fitted models, are shown to be sufficiently steep to produce either a center

  16. Modelling of acoustic pressure waves in bubbly liquids with application to sonochemical reactors

    OpenAIRE

    Dogan, Hakan

    2013-01-01

    This thesis investigates the acoustic wave propagation in bubbly liquids as part of the SONO project supported by the FP7 European Commission programme, which is aimed at developing a pilot sonochemical plant in order to produce antibacterial medical textile fabrics by coating of the textile with ZnO or CuO nanoparticles. The findings of this research are anticipated to aid the design procedures and also to provide better understanding of the micro scale physical and chemical events. Propagat...

  17. Control of ROS and RNS productions in liquid in atmospheric pressure plasma-jet system

    Science.gov (United States)

    Uchida, Giichiro; Ito, Taiki; Takenaka, Kosuke; Ikeda, Junichiro; Setsuhara, Yuichi

    2016-09-01

    Non-thermal plasma jets are of current interest in biomedical applications such as wound disinfection and even treatment of cancer tumors. Beneficial therapeutic effects in medical applications are attributed to excited species of oxygen and nitrogen from air. However, to control the production of these species in the plasma jet is difficult because their production is strongly dependent on concentration of nitrogen and oxygen from ambient air into the plasma jet. In this study, we analyze the discharge characteristics and the ROS and RNS productions in liquid in low- and high-frequency plasma-jet systems. Our experiments demonstrated the marked effects of surrounding gas near the plasma jet on ROS and RNS productions in liquid. By controlling the surround gas, the O2 and N2 main plasma jets are selectively produced even in open air. We also show that the concentration ratio of NO2- to H2O2 in liquid is precisely tuned from 0 to 0.18 in deionized water by changing N2 gas ratio (N2 / (N2 +O2)) in the main discharge gas, where high NO2- ratio is obtained at N2 gas ratio at N2 / (N2 +O2) = 0 . 8 . The low-frequency plasma jet with controlled surrounding gas is an effective plasma source for ROS and RNS productions in liquid, and can be a useful tool for biomedical applications. This study was partly supported by a Grant-in-Aid for Scientific Research on Innovative Areas ``Plasma Medical Innovation'' (24108003) from the Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT).

  18. Influences of porous reservoir Laplace pressure on emissions from passively fed ionic liquid electrospray sources

    Energy Technology Data Exchange (ETDEWEB)

    Courtney, Daniel G., E-mail: dcourtney@alum.mit.edu; Shea, Herbert [Ecole Polytechnique Federale de Lausanne (EPFL), Microsystems for Space Technologies Laboratory (LMTS), Neuchatel CH-2002 (Switzerland)

    2015-09-07

    Passively fed ionic liquid electrospray sources are capable of efficiently emitting a variety of ion beams with promising applications to spacecraft propulsion and as focused ion beams. Practical devices will require integrated or coupled ionic liquid reservoirs; the effects of which have not been explored in detail. Porous reservoirs are a simple, scalable solution. However, we have shown that their pore size can dramatically alter the beam composition. Emitting the ionic liquid 1-ethyl-3-methylimidazolium bis(triflouromethylsulfonyl)amide, the same device was shown to yield either an ion or droplet dominated beam when using reservoirs of small or large pore size, respectively; with the latter having a mass flow in excess of 15 times larger than the former at negative polarity. Another source, emitting nearly purely ionic beams of 1-ethyl-3-methylimidazolium tetrafluoroborate, was similarly shown to emit a significant droplet population when coupled to reservoirs of large (>100 μm) pores; constituting a reduction in propulsive efficiency from greater than 70% to less than 30%. Furthermore, we show that reservoir selection can alter the voltage required to obtain and sustain emission, increasing with smaller pore size.

  19. Dielectric constant of polarizable, nonpolar fluids and suspensions

    International Nuclear Information System (INIS)

    Cichocki, B.; Felderhof, B.U.

    1988-01-01

    We study the dielectric constant of a polarizable, nonpolar fluid or suspension of spherical particles by use of a renormalized cluster expansion.The particles may have induced multipole moments of any order. We show that the Clausius-Mossotti formula results from a virtual overlap contribution. The corrections to the Clausius-Mossotti formula are expressed with the aid of a cluster expansion. The integrands of the cluster integrals are expressed in terms of two-body nodal connectors which incorporate all reflections between a pair of particles. We study the two- and three-body cluster integrals in some detail and show how these are related to the dielectric virial expansion and to the first term of the Kirkwood-Yvon expansion

  20. The Thermodynamics of Anion Complexation to Nonpolar Pockets.

    Science.gov (United States)

    Sullivan, Matthew R; Yao, Wei; Tang, Du; Ashbaugh, Henry S; Gibb, Bruce C

    2018-02-08

    The interactions between nonpolar surfaces and polarizable anions lie in a gray area between the hydrophobic and Hofmeister effects. To assess the affinity of these interactions, NMR and ITC were used to probe the thermodynamics of eight anions binding to four different hosts whose pockets each consist primarily of hydrocarbon. Two classes of host were examined: cavitands and cyclodextrins. For all hosts, anion affinity was found to follow the Hofmeister series, with associations ranging from 1.6-5.7 kcal mol -1 . Despite the fact that cavitand hosts 1 and 2 possess intrinsic negative electrostatic fields, it was determined that these more enveloping hosts generally bound anions more strongly. The observation that the four hosts each possess specific anion affinities that cannot be readily explained by their structures, points to the importance of counter cations and the solvation of the "empty" hosts, free guests, and host-guest complexes, in defining the affinity.

  1. 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.

  2. Liquid pressure wireless sensor based on magnetostrictive microwires for applications in cardiovascular localized diagnostic

    Directory of Open Access Journals (Sweden)

    A. M. Aragón

    2015-08-01

    Full Text Available In this letter, we report a method to measure changes in a fluid pressure, flowing through a flexible pipeline, by means of a ring of magnetic microwire concentric to the pipeline. The detection is based on the modulated scattering of electromagnetic waves by the magnetoelastic ring. This modulation is driven by applying a low frequency bias magnetic field able to tune the magnetic permeability of the ferromagnetic microwire. Pressure detection, by means of magnetic permeability changes, is possible due to the magnetostrictive character of the sample. The experimental work developed has, also, allowed fluid pressure detection in a hydraulic circuit connected to ventricular assist system where a fluid with a viscosity close to blood flows.

  3. 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.

  4. Diagnostics of atmospheric-pressure pulsed-dc discharge with metal and liquid anodes by multiple laser-aided methods

    Science.gov (United States)

    Urabe, Keiichiro; Shirai, Naoki; Tomita, Kentaro; Akiyama, Tsuyoshi; Murakami, Tomoyuki

    2016-08-01

    The density and temperature of electrons and key heavy particles were measured in an atmospheric-pressure pulsed-dc helium discharge plasma with a nitrogen molecular impurity generated using system with a liquid or metal anode and a metal cathode. To obtain these parameters, we conducted experiments using several laser-aided methods: Thomson scattering spectroscopy to obtain the spatial profiles of electron density and temperature, Raman scattering spectroscopy to obtain the neutral molecular nitrogen rotational temperature, phase-modulated dispersion interferometry to determine the temporal variation of the electron density, and time-resolved laser absorption spectroscopy to analyze the temporal variation of the helium metastable atom density. The electron density and temperature measured by Thomson scattering varied from 2.4  ×  1014 cm-3 and 1.8 eV at the center of the discharge to 0.8  ×  1014 cm-3 and 1.5 eV near the outer edge of the plasma in the case of the metal anode, respectively. The electron density obtained with the liquid anode was approximately 20% smaller than that obtained with the metal anode, while the electron temperature was not significantly affected by the anode material. The molecular nitrogen rotational temperatures were 1200 K with the metal anode and 1650 K with the liquid anode at the outer edge of the plasma column. The density of helium metastable atoms decreased by a factor of two when using the liquid anode.

  5. Ab Initio Predictions of K, He and Ar Partitioning Between Silicate Melt and Liquid Iron Under High Pressure

    Science.gov (United States)

    Xiong, Z.; Tsuchiya, T.

    2017-12-01

    Element partitioning is an important property in recording geochemical processes during the core-mantle differentiation. However, experimental measurements of element partitioning coefficients under extreme temperature and pressure condition are still challenging. Theoretical modeling is also not easy, because it requires estimation of high temperature Gibbs free energy, which is not directly accessible by the standard molecular dynamics method. We recently developed an original technique to simulate Gibbs free energy based on the thermodynamics integration method[1]. We apply it to element partitioning of geochemical intriguing trace elements between molten silicate and liquid iron such as potassium, helium and argon as starting examples. Radiogenic potassium in the core can provide energy for Earth's magnetic field, convection in the mantle and outer core[2]. However, its partitioning behavior between silicate and iron remains unclear under high pressure[3,4]. Our calculations suggest that a clear positive temperature dependence of the partitioning coefficient but an insignificant pressure effect. Unlike sulfur and silicon, oxygen dissolved in the metals considerably enhances potassium solubility. Calculated electronic structures reveal alkali-metallic feature of potassium in liquid iron, favoring oxygen with strong electron affinity. Our results suggest that 40K could serve as a potential radiogenic heat source in the outer core if oxygen is the major light element therein.­­ We now further extend our technique to partitioning behaviors of other elements, helium and argon, to get insides into the `helium paradox' and `missing argon' problems. References [1] T. Taniuchi, and T. Tsuchiya, Phys.Rev.B. In press [2] B.A. Buffett, H.E. Huppert, J.R. Lister, and A.W. Woods, Geophys.Res.Lett. 29 (1996) 7989-8006. [3] V.R. Murthy, W. Westrenen, and Y. Fei, Nature. 426 (2003) 163-165. [4] A. Corgne, S.Keshav, Y. Fei, and W.F. McDonough, Earth.Planet.Sci.Lett. 256 (2007

  6. Development and validation of a model for high pressure liquid poison injection for CANDU-6 shutdown system no.2

    International Nuclear Information System (INIS)

    Rhee, B.-W.; Jeong, C.J.; Choi, J.H.; Yoo, S.-Y.

    2002-01-01

    In CANDU reactor one of the two reactor shutdown systems is the liquid poison injection system which injects the highly pressurized liquid neutron poison into the moderator tank via small holes on the nozzle pipes. To ensure the safe shutdown of a reactor it is necessary for the poison curtains generated by jets provide quick, and enough negative reactivity to the reactor during the early stage of the accident. In order to produce the neutron cross section necessary to perform this work, the poison concentration distribution during the transient is necessary. In this study, a set of models for analyzing the transient poison concentration induced by this high pressure poison injection jet activated upon the reactor trip in a CANDU-6 reactor moderator tank has been developed and used to generate the poison concentration distribution of the poison curtains induced by the high pressure jets injected into the vacant region between the calandria tube banks. The poison injection rate through the jet holes drilled on the nozzle pipes is obtained by a 1-D transient hydrodynamic code called, ALITRIG, and this injection rate is used to provide the inlet boundary condition to a 3-D CFD model of the moderator tank based on CFX4.3, an AEA Technology CFD code, to simulate the formation and growth of the poison jet curtain inside the moderator tank. For validation, the current model is validated against a poison injection experiment performed at BARC, India and another poison jet experiment for Generic CANDU-6 performed at AECL, Canada. In conclusion this set of models is considered to predict the experimental results in a physically reasonable and consistent manner. (author)

  7. Dynamic Pressure of Liquid Mercury Target During 800-MeV Proton Thermal Shock Tests

    International Nuclear Information System (INIS)

    Allison, S.W.; Andriulli, J.B.; Cates, M.R.; Earl, D.D.; Haines, J.R.; Morrissey, F.X.; Tsai, C.C.; Wender, S.

    2000-01-01

    Described here are efforts to diagnose transient pressures generated by a short-pulse (about 0.5 microseconds) high intensity proton (∼ 2 * 10 14 per pulse) beam. Proton energy is 800-MeV. The tests were performed at the Los Alamos Neutron Science Center - Weapons Neutron Research (LANSCE-WNR). Such capability is required for understanding target interaction for the Spallation Neutron Source project as described previously at this conference.1-4 The main approach to effect the pressure measurements utilized the deflection of a diaphragm in intimate contact with the mercury. There are a wide variety of diaphragm-deflection methods used in scientific and industrial applications. Many deflection-sensing approaches are typically used, including, for instance, capacitive and optical fiber techniques. It was found, however, that conventional pressure measurement using commercial pressure gages with electrical leads was not possible due to the intense nuclear radiation environment. Earlier work with a fiber optic strain gauge demonstrated the viability of using fiber optics for this environment

  8. Atmospheric pressure photoionisation : An ionization method for liquid chromatography-mass spectrometry

    NARCIS (Netherlands)

    Robb, DB; Covey, TR; Bruins, AP

    2000-01-01

    Atmospheric pressure photoionization (APPI) has been successfully demonstrated to provide high sensitivity to LC-MS analysis. A vacuum-ultraviolet lamp designed for photoionization detection in gas chromatography is used as a source of 10-eV photons. The mixture of samples and solvent eluting from

  9. 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

  10. Semi-solid high pressure die casting of metal matrix composites produced by liquid state processing

    CSIR Research Space (South Africa)

    Ivanchev, L

    2012-10-01

    Full Text Available stirring. The composite was then transferred to a High Pressure Die Casting (HPDC) machine in the semi-solid state. The micron size particles were found to be predominantly in the intergranular eutectic while the nano-particles were predominantly...

  11. Quantitative spatial analysis of the mouse brain lipidome by pressurized liquid extraction surface analysis

    DEFF Research Database (Denmark)

    Almeida, Reinaldo; Berzina, Zane; Christensen, Eva Arnspang

    2015-01-01

    extracted directly from tissue sections. PLESA uses a sealed and pressurized sampling probe that enables the use of chloroform-containing extraction solvents for efficient in situ lipid microextraction with a spatial resolution of 400 μm. Quantification of lipid species is achieved by the inclusion...

  12. High-pressure solubility of carbon dioxide in pyrrolidinium-based ionic liquids: [bmpyr][dca] and [bmpyr][Tf{sub 2}N

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung-Chul; Nam, Sang Gyu [Hannam University, Daejeon (Korea, Republic of)

    2015-03-15

    Solubility data of carbon dioxide (CO{sub 2}) in two pyrrolidinium-based ionic liquids: 1-butyl-1-methylpyrrolidinium dicyanamide ([bmpyr][dca]) and 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([bmpyr] [Tf{sub 2}N]) are presented at pressures up to about 30MPa and temperatures from 303..2 K to 343.2 K. The solubility was determined by measuring bubble or cloud point pressures of mixtures of CO{sub 2} and ionic liquid using a high-pressure equilibrium apparatus equipped with a variable-volume view cell. The CO{sub 2} solubility in the ionic liquid in terms of the mole fraction or the molality increased with the increase of the equilibrium pressure at a given temperature, but decreased with the increase of temperature at a given pressure. At a given temperature, the mole fraction of CO{sub 2} dissolved in the ionic liquid increased rapidly as pressure increased. CO{sub 2} solubility in the mole fraction almost reached saturation around 0.65 for [bmpyr][dca] and around 0..8 for [bmpyr][Tf{sub 2}N], respectively. The experimental data for the CO{sub 2}+ionic liquid systems were correlated using the Peng-Robinson equation of state (PR-EoS). The mixing rules of the Wong-Sandler type rather than the classical mixing rules of the van der Waals type were coupled with the PR-EoS. The resulting modeling approach proved to be able to correlate the CO{sub 2} solubilities in aforementioned ionic liquids over the aforementioned range of temperature and pressure within 5% average deviations.

  13. Use of highly pressurized liquid nitrogen technology for concrete scabbling application at SICN nuclear facility - 59282

    International Nuclear Information System (INIS)

    Moggia, Fabrice; Vaudey, Claire-Emilie; Damerval, Frederique; Varet, Thierry; Toulemonde, Valerie; Richard, Frederic; Anderson, Gary

    2012-01-01

    The decommissioning process is a quite long and complicated stage who may take few years or decades to be achieved. Generally, this process involves the implementation of a large number of technologies dedicated to cutting and decontamination operations. Based on this finding, the Clean- Up Business Unit of AREVA with Air Liquide decided to start the development of a new technology based on the use of liquid nitrogen (-140 deg. C / 3500 bar). The NitroJet R process is a quite interesting and promising technology. It can be used, as we described in this document, for concrete scabbling operations but also for decontamination and cutting applications. The Clean-Up Business Unit, with its partner Air Liquide, realized a complete study of this technology including several tests and optimizations to be able to handle it in a nuclear environment. Thus, we did: - increase of the reliability of the machine, - nuclearization of the system (including the development of efficient shroud system and efficient HP pipes insulation); - development of a dedicated bearer for automatic configuration; - optimization of parameters for D and D applications. As we already mentioned, NitroJet R technology showed promising perspectives as: - economic: increase of rate processing, decrease in site monitoring costs, - environmental: use of an inert gas, no secondary waste generation, non use of chemical, dry process, - social: less strenuous work, decrease of operator dosimetry compatible with ALARA principle The future for the NitroJet R technology will be its implementation in a real high level activity environment. This process will be used in spring 2012 in AREVA nuclear reprocessing facility of La Hague (France) to accomplish concrete scabbling applications. This test will be the last of a long development period before industrial exploitation. (authors)

  14. [Blood levels of homocysteine by high pressure liquid chromatography and comparison with two other techniques].

    Science.gov (United States)

    Ceppa, F; Drouillard, I; Chianea, D; Burnat, P; Perrier, F; Vaillant, C; El Jahiri, Y

    1999-01-01

    Cardio-vascular diseases are the most common cause of death in industrialized countries. A new marker has emerged among offending risk factors in the past few years: homocysteine. This sulphured amino-acid is an important intermediate in transsulphuration and remethylation reactions of methionine's metabolism. We proposed to evaluate a home made method of determination for this parameter by high performance liquid chromatography (HPLC) and to compare it to fluorescence polarization immunoassay technique (FPIA) and to gaz phase chromatography (CG-SM). This method associated with good sensibility and precision remain much less expensive than FPIA technique.

  15. CFD analysis of pressure drop across grid spacers in rod bundles compared to correlations and heavy liquid metal experimental data

    Energy Technology Data Exchange (ETDEWEB)

    Batta, A., E-mail: batta@kit.edu; Class, A.G., E-mail: class@kit.edu

    2017-02-15

    Early studies of the flow in rod bundles with spacer grids suggest that the pressure drop can be decomposed in contributions due to flow area variations by spacer grids and frictional losses along the rods. For these shape and frictional losses simple correlations based on theoretical and experimental data have been proposed. In the OECD benchmark study LACANES it was observed that correlations could well describe the flow behavior of the heavy liquid metal loop including a rod bundle with the exception of the core region, where different experts chose different pressure-loss correlations for the losses due to spacer grids. Here, RANS–CFD simulations provided very good data compared to the experimental data. It was observed that the most commonly applied Rehme correlation underestimated the shape losses. The available correlations relate the pressure drop across a grid spacer to the relative plugging of the spacer i.e. solidity e{sub max}. More sophisticated correlations distinct between spacer grids with round or sharp leading edge shape. The purpose of this study is to (i) show that CFD is suitable to predict pressure drop across spacer grids and (ii) to access the generality of pressure drop correlations. By verification and validation of CFD results against experimental data obtained in KALLA we show (i). The generality (ii) is challenged by considering three cases which yield identical pressure drop in the correlations. First we test the effect of surface roughness, a parameter not present in the correlations. Here we compare a simulation assuming a typical surface roughness representing the experimental situation to a perfectly smooth spacer surface. Second we reverse the flow direction for the spacer grid employed in the experiments which is asymmetric. The flow direction reversal is chosen for convenience, since an asymmetric spacer grid with given blockage ratio, may result in different flow situations depending on flow direction. Obviously blockage

  16. Development of a high performance liquid chromatography method and a liquid chromatography-tandem mass spectrometry method with pressurized liquid extraction for simultaneous quantification and confirmation of cyromazine, melamine and its metabolites in foods of animal origin

    International Nuclear Information System (INIS)

    Yu Huan; Tao Yanfei; Chen Dongmei; Wang Yulian; Liu Zhaoying; Pan Yuanhu; Huang Lingli; Peng Dapeng; Dai Menghong; Liu Zhenli; Yuan Zonghui

    2010-01-01

    Simple and sensitive methods have been developed for simultaneous detection of cyromazine, melamine and their metabolites (ammeline, ammelide and cyanuric acid) in samples of animal origins. These include a high performance liquid chromatography (HPLC) method and a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method and are useful in regular monitoring and in toxicity studies of these molecules. Representative samples used in this study include muscles and livers of swine, bovine, sheep and chicken, kidneys of swine, bovine and sheep, and milk powder. A new sample preparation procedure with pressurized liquid extraction (PLE) at 1400 psi and 70 deg. C was investigated. Quantification of these five compounds by HPLC was achieved using an APS-2 column with UV detection at 230 nm. Limit of detection (LOD) was at 10 μg kg -1 , and limit of quantification (LOQ) was at 40 μg kg -1 . Recoveries of the five analytes in spiked samples ranged from 72.2% to 115.4% with RSD less than 12%. Confirmatory analysis of the analytes was performed using LC-MS/MS in selected reaction monitoring (SRM) mode. The LOD and LOQ were 5 μg kg -1 and 15 μg kg -1 , respectively. This is the first simultaneous analysis of cyromazine, melamine, ammeline, ammelide and cyanuric acid residues in complex tissue samples using PLE and HPLC. It is expected that these methods will find many practical applications in evaluating the safety of cyromazine, melamine and their metabolites.

  17. 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.

  18. Unsteady Magnetohydrodynamic Flow of Liquid Through a Channel Variable Pressure Gradient

    International Nuclear Information System (INIS)

    Singh, C.B.

    1998-01-01

    The article studies the unsteady motion of an electrically conducting, viscous incompressible fluid along a channel in the presence of imposed transverse magnetic field, when the walls do not conduct current, under the influence of pressure gradient which varies linearly with respect to time. Analytical expressions for the velocity of the fluid for various values of Hartman numbers and at different times has been obtained

  19. Analysis of insect triacylglycerols using liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry

    Czech Academy of Sciences Publication Activity Database

    Kofroňová, Edita; Cvačka, Josef; Jiroš, Pavel; Sýkora, D.; Valterová, Irena

    2009-01-01

    Roč. 111, č. 5 (2009), s. 519-525 ISSN 1438-7697 R&D Projects: GA AV ČR IAA4055403; GA MŠk 2B06007 Institutional research plan: CEZ:AV0Z40550506 Keywords : atmospheric pressure chemical ionization * bumblebees * fat body * NARP-HPLC Subject RIV: CC - Organic Chemistry Impact factor: 1.831, year: 2009

  20. Frictional pressure drop of gas liquid two-phase flow in pipes

    International Nuclear Information System (INIS)

    Shannak, Benbella A.

    2008-01-01

    Experiments of air water two-phase flow frictional pressure drop of vertical and horizontal smooth and relatively rough pipes were conducted, respectively. The result demonstrated that the frictional pressure drop increases with increasing relative roughness of the pipe. However, the influence of the relative roughness becomes more evident at higher vapour quality and higher mass flux. A new prediction model for frictional pressure drop of two-phase flow in pipes is proposed. The model includes a new definition of the Reynolds number and the friction factor of two-phase flow. The proposed model fits the presented experimental data very well, for vertical, horizontal, smooth and rough pipes. Therefore, the reproductive accuracy of the model is tested on the experimental data existing in the open literature and compared with the most common models. The statistical comparison, based on the Friedel's Data-Bank containing of about 16,000 measured data, demonstrated that the proposed model is the best overall agreement with the data. The model was tested for a wide range of flow types, fluid systems, physical properties and geometrical parameters, typically encountered in industrial piping systems. Hence, calculating based on the new approach is sufficiently accurate for engineering purposes

  1. Prediction of non-polar gas solubilities in water, alcohols and aqueous alcohol solutions by the modified ASOG method

    Energy Technology Data Exchange (ETDEWEB)

    Tochigi, K.; Kojima, K.

    1982-07-01

    This study evaluated a technique for predicting gas solubilities based on a modified ASOG group-contribution method, considering water, alcohols, and aqueous alcohol solutions as the solvents. The nonpolar gaseous solutes considered were oxygen, nitrogen, hydrogen, carbon dioxide, argon, methane, ethane, ethylene, propane, and butane. Gas solubilities were correlated and predicted for a partial gas pressure of 1 atm and a temperature range of 50/sup 0/-100/sup 0/F (10/sup 0/-40/sup 0/C) in pure solvents, and then predicted for the same pressure and temperature range in mixed solvents using only the solubility data for the pure solvents. The deviations between the observed and predicted solubilities averaged 6.0% in pure systems and 10.2% in mixed solvents.

  2. Separation of Oligosaccharides from Lotus Seeds via Medium-pressure Liquid Chromatography Coupled with ELSD and DAD

    Science.gov (United States)

    Lu, Xu; Zheng, Zhichang; Miao, Song; Li, Huang; Guo, Zebin; Zhang, Yi; Zheng, Yafeng; Zheng, Baodong; Xiao, Jianbo

    2017-03-01

    Lotus seeds were identified by the Ministry of Public Health of China as both food and medicine. One general function of lotus seeds is to improve intestinal health. However, to date, studies evaluating the relationship between bioactive compounds in lotus seeds and the physiological activity of the intestine are limited. In the present study, by using medium pressure liquid chromatography coupled with evaporative light-scattering detector and diode-array detector, five oligosaccharides were isolated and their structures were further characterized by electrospray ionization-mass spectrometry and gas chromatography-mass spectrometry. In vitro testing determined that LOS3-1 and LOS4 elicited relatively good proliferative effects on Lactobacillus delbrueckii subsp. bulgaricus. These results indicated a structure-function relationship between the physiological activity of oligosaccharides in lotus seeds and the number of probiotics applied, thus providing room for improvement of this particular feature. Intestinal probiotics may potentially become a new effective drug target for the regulation of immunity.

  3. Simultaneous extraction and clean-up of polychlorinated biphenyls and their metabolites from small tissue samples using pressurized liquid extraction

    Science.gov (United States)

    Kania-Korwel, Izabela; Zhao, Hongxia; Norstrom, Karin; Li, Xueshu; Hornbuckle, Keri C.; Lehmler, Hans-Joachim

    2008-01-01

    A pressurized liquid extraction-based method for the simultaneous extraction and in situ clean-up of polychlorinated biphenyls (PCBs), hydroxylated (OH)-PCBs and methylsulfonyl (MeSO2)-PCBs from small (< 0.5 gram) tissue samples was developed and validated. Extraction of a laboratory reference material with hexane:dichloromethane:methanol (48:43:9, v/v) and Florisil as fat retainer allowed an efficient recovery of PCBs (78–112%; RSD: 13–37%), OH-PCBs (46±2%; RSD: 4%) and MeSO2-PCBs (89±21%; RSD: 24%). Comparable results were obtained with an established analysis method for PCBs, OH-PCBs and MeSO2-PCBs. PMID:19019378

  4. Enantioseparation of dansyl amino acids by ultra-high pressure liquid chromatography using cationic β-cyclodextrins as chiral additives.

    Science.gov (United States)

    Xiao, Yin; Tan, Timothy Thatt Yang; Ng, Siu-Choon

    2011-04-07

    This work reports the application of ultra-high pressure liquid chromatography (UHPLC) for reasonably fast enantiorecognition of some dansyl amino acids by employing three cationic β-cyclodextrins (β-CDs) as chiral additives. Good resolutions were obtained on an Agilent C18 column (2.1 mm i.d.; 1.8 μm; 50 mm length) with 1% (v/v) triethylammonium acetate buffered at pH 4.7 and acetonitrile as the mobile phase. Most of the analytes could be baseline resolved within 10 min. Increased cationic CD concentration or acetonitrile proportion in the mobile phase results in a decreased retention factor but accentuated selectivity. Furthermore, molecular mechanics calculation was performed and found to be consistent with the experimental results. © The Royal Society of Chemistry 2011

  5. High pressure liquid chromatographic assay of technetium in solutions of sodium pertechnetate produced at the AAEC Research Establishment

    International Nuclear Information System (INIS)

    Farrington, K.J.

    1985-12-01

    High pressure liquid chromatography (HPLC) is used for the assay of nanogram quantities of technetium and to determine technetium in decayed pharmaceutical products, derived from three methods of manufacture. These methods of manufacture give comparably low levels of technetium-99, at the time of collection of the solution. However, when the solutions are used to produce ready-to-inject technetium-99m, high levels of technetium-99 are present at the time of calibration, which is the day after the collection date. Where sensitive reagent kits are to be labelled, freshly collected solutions of technetium-99m should be used. The HPLC assay is a valuable technique for the quality control of technetium-based radiopharmaceuticals, and for investigation of methods of manufacture of technetium-99m. Experimental studies confirmed the findings of previous workers

  6. Bacterial Cell Wall Precursor Phosphatase Assays Using Thin-layer Chromatography (TLC) and High Pressure Liquid Chromatography (HPLC).

    Science.gov (United States)

    Pazos, Manuel; Otten, Christian; Vollmer, Waldemar

    2018-03-20

    Peptidoglycan encases the bacterial cytoplasmic membrane to protect the cell from lysis due to the turgor. The final steps of peptidoglycan synthesis require a membrane-anchored substrate called lipid II, in which the peptidoglycan subunit is linked to the carrier lipid undecaprenol via a pyrophosphate moiety. Lipid II is the target of glycopeptide antibiotics and several antimicrobial peptides, and is degraded by 'attacking' enzymes involved in bacterial competition to induce lysis. Here we describe two protocols using thin-layer chromatography (TLC) and high pressure liquid chromatography (HPLC), respectively, to assay the digestion of lipid II by phosphatases such as Colicin M or the LXG toxin protein TelC from Streptococcus intermedius . The TLC method can also monitor the digestion of undecaprenyl (pyro)phosphate, whereas the HPLC method allows to separate the di-, mono- or unphosphorylated disaccharide pentapeptide products of lipid II.

  7. Characterisation of tryptic peptides of phosphorylated tyrosine hydroxylase by high-pressure liquid chromatography electrospray ionisation mass spectrometry

    International Nuclear Information System (INIS)

    Graham, Mark E.; Dickson, Phillip W.; Dunkley, Peter R.; Nagy-Felsobuki, Ellak I. von

    2005-01-01

    Tyrosine hydroxylase (TH) is involved in the biosynthesis of catecholamines and is activated by phosphorylation. Phosphorylated TH was analysed using high-pressure liquid chromatography combined with electrospray mass spectrometry (HPLC ESI-MS). Two mass scanning methods were used to detect tryptic cleavage products of TH. In the positive electrospray ionisation mode (ESI+), the peptides that contain the phosphorylation sites of TH were identified. In the alternative method, a phosphopeptide was detected in the negative electrospray ionisation mode (ESI-) using single ion monitoring in combination with a sequential ESI+ switching experiment. A raised baseline interfered with detection of hydrophilic peptides in ESI-, with the signal-to-noise ratio indicating that the method was operating near the limit of detection for a conventional electrospray source. The switching method improved the certainty of identification of phosphopeptides

  8. Insights into Mechanistic Models for Evaporation of Organic Liquids in the Environment Obtained by Position-Specific Carbon Isotope Analysis.

    Science.gov (United States)

    Julien, Maxime; Nun, Pierrick; Robins, Richard J; Remaud, Gérald S; Parinet, Julien; Höhener, Patrick

    2015-11-03

    Position-specific isotope effects (PSIEs) have been measured by isotope ratio monitoring (13)C nuclear magnetic resonance spectrometry during the evaporation of 10 liquids of different polarities under 4 evaporation modes (passive evaporation, air-vented evaporation, low pressure evaporation, distillation). The observed effects are used to assess the validity of the Craig-Gordon isotope model for organic liquids. For seven liquids the overall isotope effect (IE) includes a vapor-liquid contribution that is strongly position-specific in polar compounds but less so in apolar compounds and a diffusive IE that is not position-specific, except in the alcohols, ethanol and propan-1-ol. The diffusive IE is diminished under forced evaporation. The position-specific isotope pattern created by liquid-vapor IEs is manifest in five liquids, which have an air-side limitation for volatilization. For the alcohols, undefined processes in the liquid phase create additional PSIEs. Three other liquids with limitations on the liquid side have a lower, highly position-specific, bulk diffusive IE. It is concluded that evaporation of organic pollutants creates unique position-specific isotope patterns that may be used to assess the progress of remediation or natural attenuation of pollution and that the Craig-Gordon isotope model is valid for the volatilization of nonpolar organic liquids with air-side limitation of the volatilization rate.

  9. Reactor for tracking catalyst nanoparticles in liquid at high temperature under a high-pressure gas phase with X-ray absorption spectroscopy.

    Science.gov (United States)

    Nguyen, Luan; Tao, Franklin Feng

    2018-02-01

    Structure of catalyst nanoparticles dispersed in liquid phase at high temperature under gas phase of reactant(s) at higher pressure (≥5 bars) is important for fundamental understanding of catalytic reactions performed on these catalyst nanoparticles. Most structural characterizations of a catalyst performing catalysis in liquid at high temperature under gas phase at high pressure were performed in an ex situ condition in terms of characterizations before or after catalysis since, from technical point of view, access to the catalyst nanoparticles during catalysis in liquid phase at high temperature under high pressure reactant gas is challenging. Here we designed a reactor which allows us to perform structural characterization using X-ray absorption spectroscopy including X-ray absorption near edge structure spectroscopy and extended X-ray absorption fine structure spectroscopy to study catalyst nanoparticles under harsh catalysis conditions in terms of liquid up to 350 °C under gas phase with a pressure up to 50 bars. This reactor remains nanoparticles of a catalyst homogeneously dispersed in liquid during catalysis and X-ray absorption spectroscopy characterization.

  10. Pressurized liquid extraction-assisted mussel cytosol preparation for the determination of metals bound to metallothionein-like proteins

    International Nuclear Information System (INIS)

    Santiago-Rivas, Sandra; Moreda-Pineiro, Antonio; Bermejo-Barrera, Pilar; Moreda-Pineiro, Jorge; Alonso-Rodriguez, Elia; Muniategui-Lorenzo, Soledad; Lopez-Mahia, Purificacion; Prada-Rodriguez, Dario

    2007-01-01

    The possibilities of pressurized liquid extraction (PLE) have been novelty tested to assist the cytosol preparation from wet mussel soft tissue before the determination of metals bound to metallothionein-like proteins (MLPs). Results obtained after PLE were compared with those obtained after a classical blending procedure for mussel cytosolic preparation. Isoforms MLP-1 (retention time of 4.1 min) and MLP-2 (retention time of 7.4 min) were separated by anion exchange high-performance liquid chromatography (HPLC) and the concentrations of Ba, Cu, Mn, Sr and Zn bound to MLP isoforms were directly measured by inductively coupled plasma-atomic emission spectrometry (ICP-OES) as a multi-element detector. The optimized PLE-assisted mussel cytosol preparation has consisted of one extraction cycle at room temperature and 1500 psi for 2 min. Since separation between the solid mussel residue and the extract (cytosol) is performed by the PLE system, the cytosol preparation method is faster than conventional cytosol preparation methods by cutting/blending using Ultraturrax or Stomacher devices

  11. Pressure drop in the flow of gas/steam liquid mixtures in pipes

    International Nuclear Information System (INIS)

    Friedel, L.

    1978-01-01

    Pressure drop in two phase flow is considered to be made up of terms for geodetical elevation or depression, acceleration, and friction. The geodetical and momentum pressure drop are discussed and reasonable correlations are presented, along with their limitations and range of application. Various relationships are available for calculating the technically important friction component. If purely empirical correlations are neclected, all the remaining predictive schemes can be related to three basic physical models. These models as well as the commonly accepted and most reliable relationships are discussed and classified according to type. Furthermore, their scope is defined and the accuracy of prediction systematicaπly compared with the aid of a newly set-up data bank. The extensive literature data consulted refer to single component two phase flow of water and various refrigerants and several two-component systems in horizontal and vertical unheated straight pipes under industrially relevant flow conditions. Finally, the accuracy of the prediction of some generally accepted void correlations is dealt with: here too, numerous published void fraction data have been gathered and checked. (orig./HP) [de

  12. Multiphase Transport in Porous Media: Gas-Liquid Separation Using Capillary Pressure Gradients International Space Station (ISS) Flight Experiment Development

    Science.gov (United States)

    Wheeler, Richard R., Jr.; Holtsnider, John T.; Dahl, Roger W.; Deeks, Dalton; Javanovic, Goran N.; Parker, James M.; Ehlert, Jim

    2013-01-01

    Advances in the understanding of multiphase flow characteristics under variable gravity conditions will ultimately lead to improved and as of yet unknown process designs for advanced space missions. Such novel processes will be of paramount importance to the success of future manned space exploration as we venture into our solar system and beyond. In addition, because of the ubiquitous nature and vital importance of biological and environmental processes involving airwater mixtures, knowledge gained about fundamental interactions and the governing properties of these mixtures will clearly benefit the quality of life here on our home planet. The techniques addressed in the current research involving multiphase transport in porous media and gas-liquid phase separation using capillary pressure gradients are also a logical candidate for a future International Space Station (ISS) flight experiment. Importantly, the novel and potentially very accurate Lattice-Boltzmann (LB) modeling of multiphase transport in porous media developed in this work offers significantly improved predictions of real world fluid physics phenomena, thereby promoting advanced process designs for both space and terrestrial applications.This 3-year research effort has culminated in the design and testing of a zero-g demonstration prototype. Both the hydrophilic (glass) and hydrophobic (Teflon) media Capillary Pressure Gradient (CPG) cartridges prepared during the second years work were evaluated. Results obtained from ground testing at 1-g were compared to those obtained at reduced gravities spanning Martian (13-g), Lunar (16-g) and zero-g. These comparisons clearly demonstrate the relative strength of the CPG phenomena and the efficacy of its application to meet NASAs unique gas-liquid separation (GLS) requirements in non-terrestrial environments.LB modeling software, developed concurrently with the zero-g test effort, was shown to accurately reproduce observed CPG driven gas-liquid separation

  13. Evidence of micropore filling for sorption of nonpolar organic contaminants by condensed organic matter.

    Science.gov (United States)

    Ran, Yong; Yang, Yu; Xing, Baoshan; Pignatello, Joseph J; Kwon, Seokjoo; Su, Wei; Zhou, Li

    2013-01-01

    Although microporosity and surface area of natural organic matter (NOM) are crucial for mechanistic evaluation of the sorption process for nonpolar organic contaminants (NOCs), they have been underestimated by the N adsorption technique. We investigated the CO-derived internal hydrophobic microporosity () and specific surface area (SSA) obtained on dry samples and related them to sorption behaviors of NOCs in water for a wide range of condensed NOM samples. The is obtained from the total CO-derived microporosity by subtracting out the contribution of the outer surfaces of minerals and NOM using N adsorption-derived parameters. The correlation between or CO-SSA and fractional organic carbon content () is very significant, demonstrating that much of the microporosity is associated with internal NOM matrices. The average and CO-SSA are, respectively, 75.1 μL g organic carbon (OC) and 185 m g OC from the correlation analysis. The rigid aliphatic carbon significantly contributes to the microporosity of the Pahokee peat. A strong linear correlation is demonstrated between / and the OC-normalized sorption capacity at the liquid or subcooled liquid-state water solubility calculated via the Freundlich equation for each of four NOCs (phenanthrene, naphthalene, 1,3,5-trichlorobenzene, and 1,2-dichlorobenzene). We concluded that micropore filling ("adsorption") contributes to NOC sorption by condensed NOM, but the exact contribution requires knowing the relationship between the dry-state, CO-determined microporosity and the wet-state, NOC-available microporosity of the organic matter. The findings offer new clues for explaining the nonideal sorption behaviors of NOCs. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  14. Preparation of YBa2Cu3O7 films by low pressure MOCVD using liquid solution sources

    International Nuclear Information System (INIS)

    Weiss, F.; Froehlich, K.; Haase, R.; Labeau, M.; Selbmann, D.; Senateur, J.P.; Thomas, O.

    1993-01-01

    A hybrid low pressure MOCVD process is described for reproducible preparation of superconducting thin films of YBa 2 Cu 3 O 7 . The process uses a single solution source of Y, Ba, and Cu β-diketonates dissolved in suitable organic solvents. This liquid precursor is atomized using an ultrasonic aerosol generator and transported as small droplets (∼1μm) into a CVD reactor where solvent and precursor are first evaporated before deposition takes place at low pressure on heated substrates in a cold wall geometry. This process allows, with stable evaporation rates for all three precursors, to grow in-situ superconducting films with constant composition from film to film. Thin and thick films with high critical temperatures and critical currents have been obtained (Tc>80K, Jc>10 4 A/cm 2 at 77K in self field) which are highly c-axis oriented. Experimental details of this new process are described and the effects of different process parameters are studied in order to improve the quality of the deposited layers. (orig.)

  15. Obtaining anthocyanin-rich extracts from frozen açai (Euterpe oleracea Mart. pulp using pressurized liquid extraction

    Directory of Open Access Journals (Sweden)

    Sylvia Carolina ALCÁZAR-ALAY

    Full Text Available Abstract Açai is considered a functional food, and in addition to being a source of energy and fiber, it is a valuable source of bioactive compounds such as anthocyanins, minerals and fatty acids. In the present work, antioxidant-rich extracts from açai pulp were obtained using pressurized liquid extraction (PLE. The effects of the independent variables, including solvent type (pure ethanol and ethanol/water (50:50 v/v, citric acid (0 and 0.3%, w/w, pressure (20 and 80 bar and temperature (30 and 60 °C were evaluated using a full factorial design. The extraction was affected primarily by the solvent type and the citric acid percentage. The results indicate that the maximum overall yield (X0 was 64± 9 (%, d.b. when the process was performed using ethanol (99.5% and citric acid (0.3% w/w. The maximum total anthocyanin content and anthocyanin recovered from the raw material were 7 ± 1 (mg anthocyanin/g extract, d.b. and 11 ± 2 (%, d.b., respectively.

  16. Optimization of pressurized liquid extraction (PLE) of dioxin-furans and dioxin-like PCBs from environmental samples.

    Science.gov (United States)

    Antunes, Pedro; Viana, Paula; Vinhas, Tereza; Capelo, J L; Rivera, J; Gaspar, Elvira M S M

    2008-05-30

    Pressurized liquid extraction (PLE) applying three extraction cycles, temperature and pressure, improved the efficiency of solvent extraction when compared with the classical Soxhlet extraction. Polychlorinated-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like PCBs (coplanar polychlorinated biphenyls (Co-PCBs)) in two Certified Reference Materials [DX-1 (sediment) and BCR 529 (soil)] and in two contaminated environmental samples (sediment and soil) were extracted by ASE and Soxhlet methods. Unlike data previously reported by other authors, results demonstrated that ASE using n-hexane as solvent and three extraction cycles, 12.4 MPa (1800 psi) and 150 degrees C achieves similar recovery results than the classical Soxhlet extraction for PCDFs and Co-PCBs, and better recovery results for PCDDs. ASE extraction, performed in less time and with less solvent proved to be, under optimized conditions, an excellent extraction technique for the simultaneous analysis of PCDD/PCDFs and Co-PCBs from environmental samples. Such fast analytical methodology, having the best cost-efficiency ratio, will improve the control and will provide more information about the occurrence of dioxins and the levels of toxicity and thereby will contribute to increase human health.

  17. Immiscible silicate liquids at high pressure: the influence of melt structure on elemental partitioning

    Energy Technology Data Exchange (ETDEWEB)

    Vicenzi, E [Princeton Materials Laboratory, Princeton, NJ (United States); Green, T H [Macquarie Univ., North Ryde, NSW (Australia); Sie, S H [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience

    1994-12-31

    Micro-PIXE analyses have been applied to study partitioning of trace elements between immiscible silicate melts stabilised at 0.5 and 1.0 GPa over a temperature range of 1160-1240 deg C in the system SiO{sub 2}-FeO-Al{sub 2}0{sub 3}-K{sub 2}0 (+P{sub 2}0{sub 5}). The system was doped with a suite of trace elements of geochemical interest: Rb, Ba, Pb, Sr, La, Ce, Sm, Ho, Y, Lu, Th, U, Zr, Hf, Nb and Ta at approximately 200 ppm level for all elements except for the REE`s, Ba and Ta (600-1200 ppm). Trace element partitioning was found to be a complex function of cation field strength (charge/radius{sup 2}). Although field strength is important in determining the nature and degree of partitioning, the authors emphasised that it is only one component of the underlying mechanism for the way in which elements distribute themselves between two silicate liquids. 8 refs., 2 figs.

  18. Immiscible silicate liquids at high pressure: the influence of melt structure on elemental partitioning

    Energy Technology Data Exchange (ETDEWEB)

    Vicenzi, E. [Princeton Materials Laboratory, Princeton, NJ (United States); Green, T.H. [Macquarie Univ., North Ryde, NSW (Australia); Sie, S.H. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience

    1993-12-31

    Micro-PIXE analyses have been applied to study partitioning of trace elements between immiscible silicate melts stabilised at 0.5 and 1.0 GPa over a temperature range of 1160-1240 deg C in the system SiO{sub 2}-FeO-Al{sub 2}0{sub 3}-K{sub 2}0 (+P{sub 2}0{sub 5}). The system was doped with a suite of trace elements of geochemical interest: Rb, Ba, Pb, Sr, La, Ce, Sm, Ho, Y, Lu, Th, U, Zr, Hf, Nb and Ta at approximately 200 ppm level for all elements except for the REE`s, Ba and Ta (600-1200 ppm). Trace element partitioning was found to be a complex function of cation field strength (charge/radius{sup 2}). Although field strength is important in determining the nature and degree of partitioning, the authors emphasised that it is only one component of the underlying mechanism for the way in which elements distribute themselves between two silicate liquids. 8 refs., 2 figs.

  19. 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.

  20. A handheld low temperature atmospheric pressure air plasma gun for nanomaterial synthesis in liquid phase

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Shuang; Wang, Kaile; Zuo, Shasha; Liu, Jiahui [Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Zhang, Jue, E-mail: zhangjue@pku.edu.cn; Fang, Jing [Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); College of Engineering, Peking University, Beijing 100871 (China)

    2015-10-15

    A handheld low temperature atmospheric pressure air plasma gun based on a dielectric barrier structure with hollow electrodes was proposed. The portable plasma gun with an embedded mini air pump was driven by a 12 V direct voltage battery. The air plasma jet generated from the gun could be touched without a common shock hazard. Besides working in air, the plasma gun can also work in water. The diagnostic result of optical emission spectroscopy showed the difference in reactive species of air plasma jet between in air and in water. The plasma gun was excited in 20 ml chloroauric acid aqueous solution with a concentration of 1.214 mM. A significant amount of gold nanoparticles were synthesized after 2 min continuous discharge. The plasma gun with these unique features is applicable in plasma medicine, etching, and s-nthesis of nanomaterials.

  1. 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...

  2. Gradual crossover in molecular organization of stable liquid H2O at moderately high pressure and temperature

    Directory of Open Access Journals (Sweden)

    Yoshikata Koga

    2014-09-01

    Full Text Available Using the literature raw data of the speed of sound and the specific volume, the isothermal compressibility, κT, a second derivative thermodynamic quantity of G, was evaluated for liquid H2O in the pressure range up to 350 MPa and the temperature to 50 ºC. We then obtained its pressure derivative, dκT/dp, a third derivative numerically without using a fitting function to the κT data. On taking yet another p-derivative at a fixed T graphically without resorting to any fitting function, the resulting d2κT/dp2, a fourth derivative, showed a weak but clear step anomaly, with the onset of the step named point X and its end point Y. In analogy with another third and fourth derivative pair in binary aqueous solutions of glycerol, dαp/dxGly and d2αp/dxGly2, at 0.1 MPa (αp is the thermal expansivity and xGly the mole fraction of solute glycerol in our recent publication [J. Solution Chem. 43, 663-674 (2014; DOI:10.1007/s10953-013-0122-7], we argue that there is a gradual crossover in the molecular organization of pure H2O from a low to a high p-regions starting at point X and ending at Y at a fixed T. The crossover takes place gradually spanning for about 100 MPa at a fixed temperature. The extrapolated temperature to zero p seems to be about 70 – 80 °C for points X and 90 – 110 °C for Y. Furthermore, the mid-points of X and Y seem to extrapolate to the triple point of liquid, ice Ih and ice III. Recalling that the zero xGly extrapolation of point X and Y for binary aqueous glycerol at 0.1 MPa gives about the same T values respectively, we suggest that at zero pressure the region below about 70 °C the hydrogen bond network is bond-percolated, while above about 90 ºC there is no hydrogen bond network. Implication of these findings is discussed.

  3. Ginzburg-Landau-type theory of nonpolarized spin superconductivity

    Science.gov (United States)

    Lv, Peng; Bao, Zhi-qiang; Guo, Ai-Min; Xie, X. C.; Sun, Qing-Feng

    2017-01-01

    Since the concept of spin superconductor was proposed, all the related studies concentrate on the spin-polarized case. Here, we generalize the study to the spin-non-polarized case. The free energy of nonpolarized spin superconductor is obtained, and Ginzburg-Landau-type equations are derived by using the variational method. These Ginzburg-Landau-type equations can be reduced to the spin-polarized case when the spin direction is fixed. Moreover, the expressions of super linear and angular spin currents inside the superconductor are derived. We demonstrate that the electric field induced by the super spin current is equal to the one induced by an equivalent charge obtained from the second Ginzburg-Landau-type equation, which shows self-consistency of our theory. By applying these Ginzburg-Landau-type equations, the effect of electric field on the superconductor is also studied. These results will help us get a better understanding of the spin superconductor and related topics such as the Bose-Einstein condensate of magnons and spin superfluidity.

  4. High pressure flow reactor for in situ X-ray absorption spectroscopy of catalysts in gas-liquid mixtures—A case study on gas and liquid phase activation of a Co-Mo/Al2O3 hydrodesulfurization catalyst

    NARCIS (Netherlands)

    van Haandel, L.; Hensen, E.J.M.; Weber, Th.

    2017-01-01

    An in situ characterization of heterogeneous catalysts under industrial operating conditions may involve high pressure and reactants in both the gas and the liquid phase. In this paper, we describe an in situ XAS flow reactor, which is suitable to operate under such conditions (pmax 20 bar, Tmax 350

  5. Adsorption of polar, nonpolar, and substituted aromatics to colloidal graphene oxide nanoparticles

    NARCIS (Netherlands)

    Wang, Fang; Haftka, Joris J H; Sinnige, Theo L.; Hermens, Joop L M; Chen, Wei

    2014-01-01

    We conducted batch adsorption experiments to understand the adsorptive properties of colloidal graphene oxide nanoparticles (GONPs) for a range of environmentally relevant aromatics and substituted aromatics, including model nonpolar compounds (pyrene, phenanthrene, naphthalene, and

  6. High-pressure (vapour + liquid) equilibria for ternary systems composed by {(E)-2-hexenal or hexanal + carbon dioxide + water}: Partition coefficient measurement

    International Nuclear Information System (INIS)

    Bejarano, Arturo; López, Pablo I.; Valle, José M. del; Fuente, Juan C. de la

    2015-01-01

    Highlights: • A new apparatus based on a static–analytic method was assembled in this work. • This work reports high-pressure VLE data of (E)-2-hexenal or hexanal + CO 2 + water. • Data includes (CO 2 + water) partition coefficients of (E)-2-hexenal and hexanal. • High separation factors from water (∼10 4 ) were found especially for (E)-2-hexenal. • The data were obtained at T = (313, 323, and 333) K and pressures from (8 to 19) MPa. - Abstract: A new apparatus based on a static–analytic method assembled in this work was utilised to perform high-pressure (vapour + liquid) equilibria measurements of aqueous ternary systems. This work includes values of isothermal partition coefficients between CO 2 and water of two apple aroma constituents, (E)-2-hexenal and hexanal. Additionally, this work reports new experimental (vapour + liquid) equilibria measurements for the ternary systems (CO 2 + (E)-2-hexenal + water) and (CO 2 + hexanal + water), at fixed liquid phase composition (600 mg · kg −1 ), at temperatures of (313, 323 and 333) K and at pressures from (8 to 19) MPa. Vapour liquid interphase was checked and monitored visually for all the systems studied in this work. No liquid immiscibility was observed at the composition, temperatures and pressures studied. In order to suggest reasonable operation conditions for fractionation of aromas with dense carbon dioxide, partition coefficients of the aroma compounds between CO 2 and water along with their separation factors from water were calculated. Partition coefficients of (E)-2-hexenal between CO 2 and water were in the range of (6 to 91) and where found to be near six times higher than those of hexanal (9 to 17). Very high separation factors from water were observed (∼10 4 ) especially for (E)-2-hexenal. The highest separation factor, for both compounds, was found at a temperature of 313 K and pressures from (12 to 14) MPa

  7. Design technique for all-dielectric non-polarizing beam splitter plate

    Science.gov (United States)

    Rizea, A.

    2012-03-01

    There are many situations when, for the proper working, an opto-electronic device requiring optical components does not change the polarization state of light after a reflection, splitting or filtering. In this paper, a design for a non-polarizing beam splitter plate is proposed. Based on certain optical properties of homogeneous dielectric materials we will establish a reliable thin film package formula, excellent for the start of optimization to obtain a 20-nm bandwidth non-polarizing beam splitter.

  8. Pressurized liquid extraction and chemical characterization of safflower oil: A comparison between methods.

    Science.gov (United States)

    Conte, Rogério; Gullich, Letícia M D; Bilibio, Denise; Zanella, Odivan; Bender, João P; Carniel, Naira; Priamo, Wagner L

    2016-12-15

    This work investigates the extraction process of safflower oil using pressurized ethanol, and compares the chemical composition obtained (in terms of fatty acids) with other extraction techniques. Soxhlet and Ultrasound showed maximum global yield of 36.53% and 30.41%, respectively (70°C and 240min). PLE presented maximum global yields of 25.62% (3mLmin(-1)), 19.94% (2mLmin(-1)) and 12.37% (1mLmin(-1)) at 40°C, 100bar and 60min. Palmitic acid showed the lower concentration in all experimental conditions (from 5.70% to 7.17%); Stearic and Linoleic acid presented intermediate concentrations (from 2.93% to 25.09% and 14.09% to 19.06%, respectively); Oleic acid showed higher composition (from 55.12% to 83.26%). Differences between percentages of fatty acids, depending on method were observed. Results may be applied to maximize global yields and select fatty acids, reducing the energetic costs and process time. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Dispersive liquid-liquid microextraction for the determination of vitamins D and K in foods by liquid chromatography with diode-array and atmospheric pressure chemical ionization-mass spectrometry detection.

    Science.gov (United States)

    Viñas, Pilar; Bravo-Bravo, María; López-García, Ignacio; Hernández-Córdoba, Manuel

    2013-10-15

    A simple and rapid method was developed using reversed-phase liquid chromatography (LC) with both diode array (DAD) and atmospheric pressure chemical ionization mass spectrometric (APCI-MS) detection, for the simultaneous analysis of the vitamins ergocalciferol (D2), cholecalciferol (D3), phylloquinone (K1), menaquinone-4 (K2) and a synthetic form of vitamin K, menadione (K3). The Taguchi experimental method, an orthogonal array design (OAD), was used to optimize an efficient and clean preconcentration step based on dispersive liquid-liquid microextraction (DLLME). A factorial design was applied with six factors and three levels for each factor, namely, carbon tetrachloride volume, methanol volume, aqueous sample volume, pH of sample, sodium chloride concentration and time of the centrifugation step. The DLLME optimized procedure consisted of rapidly injecting 3 mL of acetonitrile (disperser solvent) containing 150 µL carbon tetrachloride (extraction solvent) into the aqueous sample, thereby forming a cloudy solution. Phase separation was performed by centrifugation, and the sedimented phase was evaporated with nitrogen, reconstituted with 50 µL of acetonitrile, and injected. The LC analyses were carried out using a mobile phase composed of acetonitrile, 2-propanol and water, under gradient elution. Quantification was carried out by the standard additions method. The APCI-MS spectra, in combination with UV spectra, permitted the correct identification of compounds in the food samples. The method was validated according to international guidelines and using a certified reference material. The validated method was applied for the analysis of vitamins D and K in infant foods and several green vegetables. There was little variability in the forms of vitamin K present in vegetables, with the most abundant vitamer in all the samples being phylloquinone, while menadione could not be detected. Conversely, cholecalciferol, which is present in food of animal origin, was

  10. Determination of pharmaceuticals in sewage sludge by pressurized liquid extraction (PLE) coupled to liquid chromatography-tandem mass spectrometry (LC-MS/MS).

    Science.gov (United States)

    Radjenović, J; Jelić, A; Petrović, M; Barceló, D

    2009-03-01

    In this study, we aimed at optimizing a sensitive and reliable method for a simultaneous determination of 31 pharmaceuticals belonging to predominant therapeutic classes identified in different types of sewage sludge proceeding from conventional and advanced wastewater treatment. Freeze-dried sewage sludge was extracted by pressurized liquid extraction technique using accelerated solvent extractor Dionex 300. In order to minimize interferences with matrix components and to preconcentrate target analytes, solid phase extraction was introduced in the method as a clean-up step. The entire method was validated for linearity, precision, accuracy, and method detection limits (MDLs). The method turned out to be specific, sensitive, and reliable for the analysis of sludge of different composition, type, and retention time in the process. The developed sample preparation protocol and previously published method for LC-MS/MS analysis (Gros et al., Talanta 70:678-690, 2006) were successfully applied to monitor the target pharmaceuticals in different types of sewage sludge, i.e., primary sludge, secondary sludge, treated sludge, and sludge proceeding from pilot-scale membrane bioreactors (MBRs) operating in parallel to the conventional activated sludge treatment. Among the investigated pharmaceuticals, 20 were detected in the sludge proceeding from full-scale installations, whereas the MBR sludge concentrations were below MDLs for several compounds. The highest concentrations were recorded for treated and primary sludge. For example, the mean concentration of ibuprofen in the digested sludge was 299.3 +/- 70.9 ng g(-1) dw, whereas in the primary sludge, it was enriched up to 741.1 ng g(-1) dw. Other pharmaceuticals detected at relatively high concentrations were diclofenac, erythromycin, glibenclamide, ketoprofen, ofloxacin, azithromycin (up to 380.7, 164.2, 190.7, 336.3, 454.7, 299.6 ng g(-1) dw in the primary sludge, respectively), gemfibrozil, loratidine, and fluoxetine (up

  11. High-pressure phase behavior of systems with ionic liquids: Part V. The binary system carbon dioxide+1-butyl-3-methylimidazolium tetrafluoroborate

    NARCIS (Netherlands)

    Kroon, M.C.; Shariati - Sarabi, A.; Costantini, M.; Spronsen, van J.; Witkamp, G.J.; Sheldon, R.A.; Peters, C.J.

    2005-01-01

    The phase behavior of the binary system consisting of the supercritical fluid carbon dioxide (CO2) and the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]) was studied experimentally. A synthetic method was used to measure its phase behavior. Bubble-point pressures of the

  12. Pre-Service Primary Science Teachers' Understandings of the Effect of Temperature and Pressure on Solid-Liquid Phase Transition of Water

    Science.gov (United States)

    Yalcin, Fatma Aggul

    2012-01-01

    The aim of this study was to explore pre-service primary teachers' understandings of the effect of temperature and pressure on the solid-liquid phase transition of water. In the study a survey approach was used, and the sample consisted of one-hundred and three, third year pre-service primary science teachers. As a tool for data collection, a test…

  13. beta-Glucuronidase-resistant bilirubin glucuronide isomers in cholestatic liver disease--determination of bilirubin metabolites in serum by means of high-pressure liquid chromatography

    NARCIS (Netherlands)

    Jansen, P. L.

    1981-01-01

    "Direct reacting bilirubin" in serum of patients with cholestatic liver disease and in serum of bile duct-ligated rats consists of a complex mixture of bilirubin metabolites. These metabolites were studied by means of high-pressure liquid chromatography. Bilirubin glucuronides in normal bile are

  14. COMPARISONS OF SOXHLET EXTRACTION, PRESSURIZED LIQUID EXTRACTION, SUPERCRITICAL FLUID EXTRACTION, AND SUBCRITICAL WATER EXTRACTION FOR ENVIRONMENTAL SOLIDS: RECOVERY, SELECTIVITY, AND EFFECTS ON SAMPLE MATRIX. (R825394)

    Science.gov (United States)

    Extractions of a polycyclic aromatic hydrocarbon (PAH)-contaminated soil from a former manufactured gas plant site were performed with a Soxhlet apparatus (18 h), by pressurized liquid extraction (PLE) (50 min at 100°C), supercritical fluid extraction (SFE) (1 h at 150°...

  15. A new liquid chromatography - tandem mass spectrometry method using atmospheric pressure photo ionization for the simultaneous determination of azaarenes and azaarones in Dutch river sediments

    NARCIS (Netherlands)

    Brulik, J.; Simek, Z.; de Voogt, P.

    2013-01-01

    A new method for the analysis of azaarenes and their degradation products (azaarones) was developed, optimized and validated using liquid chromatography coupled with atmospheric pressure photo ionization tandem mass spectrometric detection (LC-APPI/MS/MS). Seventeen compounds including 4 PAHs

  16. Combination of high pressure liquid chromatography and radioimmunoassay is a powerful tool for the specific and quantitative determination of endorphins and related peptides

    NARCIS (Netherlands)

    Loeber, J.G.; Verhoef, J.; Burbach, J.P.H.; Witter, A.

    1979-01-01

    A method for the separation and subsequent quantification of endorphins and related peptides was developed. Separation of the peptides was achieved by high pressure liquid chromatography on a reversed phase column. By virtue of the high resolving capacity of this system peptides differing in only

  17. Difference in cellular damage and cell death in thermal death time disks and high hydrostatic pressure treated Salmonella Enteritidis (ATCC13076) in liquid whole egg

    Science.gov (United States)

    Differences in membrane damage including leakage of intracellular UV-materials and loss of viability of Salmonella Enteritidis (ATCC13076) in liquid whole egg (LWE) following thermal-death-time (TDT) disk and high hydrostatic pressure treatments were examined. Salmonella enteritidis was inoculated ...

  18. The use of ultra-high pressure liquid chromatography with tandem mass spectrometric detection of analysis of agrochemical residues and mycotoxines in food - challenges and applications

    Science.gov (United States)

    In the field of food contaminant analysis, the most significant development of recent years has been the integration of ultra-high pressure liquid chromatography (UHPLC), coupled to tandem quadrupole mass spectrometry (MS/MS), into analytical applications. In this review, we describe the emergence o...

  19. The influence of non-polar lipids on tear film dynamics

    KAUST Repository

    Bruna, M.

    2014-04-04

    © 2014 Cambridge University Press. In this paper we examine the effect that physiological non-polar lipids, residing on the surface of an aqueous tear film, have on the film evolution. In our model we track the evolution of the thickness of the non-polar lipid layer, the thickness of the aqueous layer and the concentration of polar lipids which reside at the interface between the two. We also utilise a force balance in the non-polar lipid layer in order to determine its velocity. We show how to obtain previous models in the literature from our model by making particular choices of the parameters. We see the formation of boundary layers in some of these submodels, across which the concentration of polar lipid and the non-polar lipid velocity and film thickness vary. We solve our model numerically for physically realistic parameter values, and we find that the evolution of the aqueous layer and the polar lipid layer are similar to that described by previous authors. However, there are interesting dynamics for the non-polar lipid layer. The effects of altering the key parameters are highlighted and discussed. In particular, we see that the Marangoni number plays a key role in determining how far over the eye the non-polar lipid spreads.

  20. A high pressure x-ray photoelectron spectroscopy experimental method for characterization of solid-liquid interfaces demonstrated with a Li-ion battery system

    Energy Technology Data Exchange (ETDEWEB)

    Maibach, Julia; Xu, Chao; Gustafsson, Torbjörn; Edström, Kristina [Department of Chemistry–Ångström Laboratory, Uppsala University, Box 538, SE-751 21 Uppsala (Sweden); Eriksson, Susanna K. [Department of Chemistry–Ångström Laboratory, Uppsala University, Box 523, SE-751 20 Uppsala (Sweden); Åhlund, John [VG Scienta AB, Box 15120, SE-750 15 Uppsala (Sweden); Siegbahn, Hans; Rensmo, Håkan; Hahlin, Maria, E-mail: maria.hahlin@physics.uu.se [Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala (Sweden)

    2015-04-15

    We report a methodology for a direct investigation of the solid/liquid interface using high pressure x-ray photoelectron spectroscopy (HPXPS). The technique was demonstrated with an electrochemical system represented by a Li-ion battery using a silicon electrode and a liquid electrolyte of LiClO{sub 4} in propylene carbonate (PC) cycled versus metallic lithium. For the first time the presence of a liquid electrolyte was realized using a transfer procedure where the sample was introduced into a 2 mbar N{sub 2} environment in the analysis chamber without an intermediate ultrahigh vacuum (UHV) step in the load lock. The procedure was characterized in detail concerning lateral drop gradients as well as stability of measurement conditions over time. The X-ray photoelectron spectroscopy (XPS) measurements demonstrate that the solid substrate and the liquid electrolyte can be observed simultaneously. The results show that the solid electrolyte interphase (SEI) composition for the wet electrode is stable within the probing time and generally agrees well with traditional UHV studies. Since the methodology can easily be adjusted to various high pressure photoelectron spectroscopy systems, extending the approach towards operando solid/liquid interface studies using liquid electrolytes seems now feasible.

  1. Effect of temperature and density fluctuations on the spatially heterogeneous dynamics of glass-forming Van der Waals liquids under high pressure.

    Science.gov (United States)

    Koperwas, K; Grzybowski, A; Grzybowska, K; Wojnarowska, Z; Sokolov, A P; Paluch, M

    2013-09-20

    In this Letter, we show how temperature and density fluctuations affect the spatially heterogeneous dynamics at ambient and elevated pressures. By using high-pressure experimental data for van der Waals liquids, we examine contributions of the temperature and density fluctuations to the dynamics heterogeneity. We show that the dynamic heterogeneity decreases significantly with increasing pressure at a constant structural relaxation time (isochronal condition), while the broadening of the relaxation spectrum remains constant. This observation questions the relationship between spectral broadening and dynamic heterogeneity.

  2. Special topics reports for the reference tandem mirror fusion breeder: liquid metal MHD pressure drop effects in the packed bed blanket. Vol. 1

    International Nuclear Information System (INIS)

    McCarville, T.J.; Berwald, D.H.; Wong, C.P.C.

    1984-09-01

    Magnetohydrodynamic (MHD) effects which result from the use of liquid metal coolants in magnetic fusion reactors include the modification of flow profiles (including the suppression of turbulence) and increases in the primary loop pressure drop and the hydrostatic pressure at the first wall of the blanket. In the reference fission-suppressed tandem mirror fusion breeder design concept, flow profile modification is a relatively minor concern, but the MHD pressure drop in flowing the liquid lithium coolant through an annular packed bed of beryllium/thorium pebbles is directly related to the required first wall structure thickness. As such, it is a major concern which directly impacts fissile breeding efficiency. Consequently, an improved model for the packed bed pressure drop has been developed. By considering spacial averages of electric fields, currents, and fluid flow velocities the general equations have been reduced to simple expressions for the pressure drop. The averaging approach results in expressions for the pressure drop involving a constant which reflects details of the flow around the pebbles. Such details are difficult to assess analytically, and the constant may eventually have to be evaluated by experiment. However, an energy approach has been used in this study to bound the possible values of the constant, and thus the pressure drop. In anticipation that an experimental facility might be established to evaluate the undetermined constant as well as to address other uncertainties, a survey of existing facilities is presented

  3. Separation of toluene from alkanes using 1-ethyl-3-methylpyridinium ethylsulfate ionic liquid at T = 298.15 K and atmospheric pressure

    International Nuclear Information System (INIS)

    Gonzalez, Emilio J.; Calvar, Noelia; Gonzalez, Begona; Dominguez, Angeles

    2010-01-01

    In this paper, the separation of toluene from aliphatic hydrocarbons (heptane, or octane, or nonane) was analyzed by solvent extraction with 1-ethyl-3-methylpyridinium ethylsulfate ionic liquid, [EMpy][ESO 4 ]. Liquid-liquid equilibrium (LLE) data for the ternary systems {heptane (1) + toluene (2) + [EMpy][ESO 4 ] (3)}, {octane (1) + toluene (2) + [EMpy][ESO 4 ] (3)}, and {nonane (1) + toluene (2) + [EMpy][ESO 4 ] (3)} were obtained by measurements at T = 298.15 K and atmospheric pressure. The selectivity, % removal of aromatic, and solute distribution ratio, obtained from experimental equilibrium results, were used to determine the ability of [EMpy][ESO 4 ] as a solvent. The degree of consistency of the experimental LLE values was ascertained using the Othmer-Tobias and Hand equations. The experimental results for the ternary systems were correlated with the NRTL model. Finally, the results obtained were compared with other ionic liquids and other solvents.

  4. Measurement of gas-liquid two-phase flow around horizontal tube bundle using SF6-water. Simulating high-pressure high-temperature gas-liquid two-phase flow of PWR/SG secondary coolant side at normal pressure

    International Nuclear Information System (INIS)

    Ishikawa, Atsushi; Imai, Ryoj; Tanaka, Takahiro

    2014-01-01

    In order to improve prediction accuracy of analysis code used for design and development of industrial products, technology had been developed to create and evaluate constitutive equation incorporated in analysis code. The experimental facility for PWR/SG U tubes part was manufactured to measure local void fraction and gas-liquid interfacial velocity with forming gas-liquid upward two-phase flow simulating high-pressure high-temperature secondary coolant (water-steam) rising vertically around horizontal tube bundle. The experimental facility could reproduce flow field having gas-liquid density ratio equivalent to real system with no heating using SF6 (Sulfur Hexafluoride) gas at normal temperature and pressure less than 1 MPa, because gas-liquid density ratio, surface tension and gas-liquid viscosity ratio were important parameters to determine state of gas-liquid two-phase flow and gas-liquid density ratio was most influential. Void fraction was measured by two different methods of bi-optical probe and conductivity type probe. Test results of gas-liquid interfacial velocity vs. apparent velocity were in good agreement with existing empirical equation within 10% error, which could confirm integrity of experimental facility and appropriateness of measuring method so as to set up original constitutive equation in the future. (T. Tanaka)

  5. Standardization of a fluconazole bioassay and correlation of results with those obtained by high-pressure liquid chromatography.

    Science.gov (United States)

    Rex, J H; Hanson, L H; Amantea, M A; Stevens, D A; Bennett, J E

    1991-01-01

    An improved bioassay for fluconazole was developed. This assay is sensitive in the clinically relevant range (2 to 40 micrograms/ml) and analyzes plasma, serum, and cerebrospinal fluid specimens; bioassay results correlate with results obtained by high-pressure liquid chromatography (HPLC). Bioassay and HPLC analyses of spiked plasma, serum, and cerebrospinal fluid samples (run as unknowns) gave good agreement with expected values. Analysis of specimens from patients gave equivalent results by both HPLC and bioassay. HPLC had a lower within-run coefficient of variation (less than 2.5% for HPLC versus less than 11% for bioassay) and a lower between-run coefficient of variation (less than 5% versus less than 12% for bioassay) and was more sensitive (lower limit of detection, 0.1 micrograms/ml [versus 2 micrograms/ml for bioassay]). The bioassay is, however, sufficiently accurate and sensitive for clinical specimens, and its relative simplicity, low sample volume requirement, and low equipment cost should make it the technique of choice for analysis of routine clinical specimens. PMID:1854166

  6. Hg+ ion density in low-pressure Ar-Hg discharge plasma used for liquid crystal display back-lighting

    International Nuclear Information System (INIS)

    Goto, Miki; Arai, Toshihiko

    1995-01-01

    The positive column of a low-pressure Ar-Hg discharge has been applied as a fluorescent light source for illumination. Many studies on the diagnostics and fundamental mechanisms have been carried out on both the classical fluorescent lamp (d=36 mm) and the compact fluorescent lamp (d=12 mm). On the other hand, a lamp of extremely narrow diameter (usually below 6 mm) has been recently developed for liquid crystal display (LCD) back-lighting and its importance is undoubtedly increasing. Some characteristics or mechanisms of the narrow-diameter lamp may be similar to those of the 36 mm one; however the similarity rule does not hold between them due to the contributions from a stepwise ionization process. Therefore, in order to clarify the excitation mechanism in the narrow-diameter lamp quantitatively, various parameters must be measured directly and some analysis must be done. The Hg + ion density and electron density are important parameters for the purpose of clarifying the excitation mechanism quantitatively. In this work, we have measured the Hg + ion density using the modified absorption method, and the electron density using the probe method in the Ar-Hg discharge of the 4 mm bore tube on bath temperature. Moreover, with combining the modified absorption method and the probe method, the Hg 2 + molecular ion density has been determined

  7. Pressurized liquid extracts from Spirulina platensis microalga. Determination of their antioxidant activity and preliminary analysis by micellar electrokinetic chromatography.

    Science.gov (United States)

    Herrero, Miguel; Ibáñez, Elena; Cifuentes, Alejandro; Señoráns, Javier

    2004-08-27

    In this work, different extracts from the microalga Spirulina platensis are obtained using pressurized liquid extraction (PLE) and four different solvents (hexane, light petroleum, ethanol and water). Different extraction temperatures (115 and 170 degrees C) were tested using extraction times ranging from 9 to 15 min. The antioxidant activity of the different extracts is determined by means of an in vitro assay using a free radical method. Moreover, a new and fast method is developed using micellar electrokinetic chromatography with diode array detection (MEKC-DAD) to provide a preliminary analysis on the composition of the extracts. This combined application (i.e., in vitro assays plus MEKC-DAD) allowed the fast characterization of the extracts based on their antioxidant activity and the UV-vis spectra of the different compounds found in the extracts. To our knowledge, this work shows for the first time the great possibilities of the combined use of PLE-in vitro assay-MEKC-DAD to investigate natural sources of antioxidants.

  8. Selective extraction of high-value phenolic compounds from distillation wastewater of basil (Ocimum basilicum L.) by pressurized liquid extraction.

    Science.gov (United States)

    Pagano, Imma; Sánchez-Camargo, Andrea Del Pilar; Mendiola, Jose Antonio; Campone, Luca; Cifuentes, Alejandro; Rastrelli, Luca; Ibañez, Elena

    2018-01-31

    During the essential oil steam distillation from aromatic herbs, huge amounts of distillation wastewaters (DWWs) are generated. These by-products represent an exceptionally rich source of phenolic compounds such as rosmarinic acid (RA) and caffeic acid (CA). Herein, the alternative use of dried basil DWWs (dDWWs) to perform a selective extraction of RA and CA by pressurized liquid extraction (PLE) employing bio-based solvent was studied. To select the most suitable solvent for PLE, the theoretical modelling of Hansen solubility parameters (HSP) was carried out. This approach allows reducing the list of candidate to two solvents: ethanol and ethyl lactate. Due to the composition of the sample, mixtures of water with those solvents were also tested. An enriched PLE extract in RA (23.90 ± 2.06 mg/g extract) with an extraction efficiency of 75.89 ± 16.03% employing a water-ethanol mixture 25:75 (% v/v) at 50°C was obtained. In the case of CA, a PLE extract with 2.42 ± 0.04 mg/g extract, having an extraction efficiency of 13.86 ± 4.96% using ethanol absolute at 50°C was achieved. DWWs are proposed as new promising sources of natural additives and/or functional ingredients for cosmetic, nutraceutical, and food applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Application of atmospheric-pressure plasma jet processed carbon nanotubes to liquid and quasi-solid-state gel electrolyte supercapacitors

    Science.gov (United States)

    Kuok, Fei-Hong; Kan, Ken-Yuan; Yu, Ing-Song; Chen, Chieh-Wen; Hsu, Cheng-Che; Cheng, I.-Chun; Chen, Jian-Zhang

    2017-12-01

    We use a dc-pulse nitrogen atmospheric-pressure plasma jet (APPJ) to calcine carbon nanotubes (CNTs) pastes that are screen-printed on carbon cloth. 30-s APPJ treatment can efficiently oxidize and vaporize the organic binders, thereby forming porous structures. As indicated by X-ray photoelectron spectroscopy (XPS) and electron probe microanalysis (EPMA), the oxygen content decreases after APPJ treatment owing to the oxidation and vaporization of ethyl cellulose, terpineol, and ethanol. Nitrogen doping was introduced to the materials by the nitrogen APPJ. APPJ-calcination improves the wettability of the CNTs printed on carbon cloth, as evidenced by water contact angle measurement. Raman spectroscopy indicates that reactive species of nitrogen APPJ react violently with CNTs in only 30-s APPJ processing time and introduce defects and/or surface functional groups on CNTs. Carbon cloths with calcined CNT layers are used as electrodes for liquid and quasi-solid-state electrolyte supercapacitors. Under a cyclic voltammetry test with a 2 mV/s potential scan rate, the specific capacitance is 73.84 F/g (areal capacitance = 5.89 mF/cm2) with a 2 M KCl electrolyte and 66.47 F/g (areal capacitance = 6.10 mF/cm2) with a H2SO4/polyvinyl alcohol (PVA) gel electrolyte.

  10. Pressurized planar electrochromatography, high-performance thin-layer chromatography and high-performance liquid chromatography--comparison of performance.

    Science.gov (United States)

    Płocharz, Paweł; Klimek-Turek, Anna; Dzido, Tadeusz H

    2010-07-16

    Kinetic performance, measured by plate height, of High-Performance Thin-Layer Chromatography (HPTLC), High-Performance Liquid Chromatography (HPLC) and Pressurized Planar Electrochromatography (PPEC) was compared for the systems with adsorbent of the HPTLC RP18W plate from Merck as the stationary phase and the mobile phase composed of acetonitrile and buffer solution. The HPLC column was packed with the adsorbent, which was scrapped from the chromatographic plate mentioned. An additional HPLC column was also packed with adsorbent of 5 microm particle diameter, C18 type silica based (LiChrosorb RP-18 from Merck). The dependence of plate height of both HPLC and PPEC separating systems on flow velocity of the mobile phase and on migration distance of the mobile phase in TLC system was presented applying test solute (prednisolone succinate). The highest performance, amongst systems investigated, was obtained for the PPEC system. The separation efficiency of the systems investigated in the paper was additionally confirmed by the separation of test component mixture composed of six hormones. 2010 Elsevier B.V. All rights reserved.

  11. Extraction of bioactive carbohydrates from artichoke (Cynara scolymus L.) external bracts using microwave assisted extraction and pressurized liquid extraction.

    Science.gov (United States)

    Ruiz-Aceituno, Laura; García-Sarrió, M Jesús; Alonso-Rodriguez, Belén; Ramos, Lourdes; Sanz, M Luz

    2016-04-01

    Microwave assisted extraction (MAE) and pressurized liquid extraction (PLE) methods using water as solvent have been optimized by means of a Box-Behnken and 3(2) composite experimental designs, respectively, for the effective extraction of bioactive carbohydrates (inositols and inulin) from artichoke (Cynara scolymus L.) external bracts. MAE at 60 °C for 3 min of 0.3 g of sample allowed the extraction of slightly higher concentrations of inositol than PLE at 75 °C for 26.7 min (11.6 mg/g dry sample vs. 7.6 mg/g dry sample). On the contrary, under these conditions, higher concentrations of inulin were extracted with the latter technique (185.4 mg/g vs. 96.4 mg/g dry sample), considering two successive extraction cycles for both techniques. Both methodologies can be considered appropriate for the simultaneous extraction of these bioactive carbohydrates from this particular industrial by-product. To the best of our knowledge this is the first time that these techniques are applied for this purpose. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Evaluation of Carbohydrates in Natural and Cultured Cordyceps by Pressurized Liquid Extraction and Gas Chromatography Coupled with Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Jia Guan

    2010-06-01

    Full Text Available Free and polymeric carbohydrates in Cordyceps, a valued edible mushroom and well-known traditional Chinese medicine, were determined using stepwise pressurized liquid extraction (PLE extraction and GC-MS. Based on the optimized PLE conditions, acid hydrolysis and derivatization, ten monosaccharides, namely rhamnose, ribose, arabinose, xylose, mannose, glucose, galactose, mannitol, fructose and sorbose in 13 samples of natural and cultured Cordyceps were qualitatively and quantitatively analyzed and compared with myo-inositol hexaacetate as internal standard. The results showed that natural C. sinensis contained more than 7.99% free mannitol and a small amount of glucose, while its polysaccharides were usually composed of mannose, glucose and galactose with a molar ratio of 1.00:16.61~3.82:1.60~1.28. However, mannitol in cultured C. sinensis and cultured C. militaris were less than 5.83%, and free glucose was only detected in a few samples, while their polysaccharides were mainly composed of mannose, glucose and galactose with molar ratios of 1.00:3.01~1.09:3.30~1.05 and 1.00:2.86~1.28:1.07~0.78, respectively. Natural and cultured Cordyceps could be discriminated by hierarchical clustering analysis based on its free carbohydrate contents.

  13. Trace determination of 13 haloacetamides in drinking water using liquid chromatography triple quadrupole mass spectrometry with atmospheric pressure chemical ionization.

    Science.gov (United States)

    Chu, Wenhai; Gao, Naiyun; Yin, Daqiang; Krasner, Stuart W; Templeton, Michael R

    2012-04-27

    The haloacetamides (HAcAms) are disinfection by-products (DBPs) in drinking water which are currently receiving increased scientific attention due to their elevated toxicity relative to regulated disinfection by-products. A simultaneous determination method of 13 HAcAms, combining solid-phase extraction (SPE) enrichment, liquid chromatographic (LC) separation, and triple quadrupole mass spectrometry (tqMS) detection with atmospheric pressure chemical ionization (APCI) using selective reaction monitoring in positive mode, was developed to measure HAcAms, including chlorinated, brominated, and iodinated analogs. Ammonium chloride and Oasis HLB were selected as the dechlorinating reagent and polymeric SPE sorbent of HAcAm samples. The used tqMS apparatus showed higher sensitivity for the studied HAcAms in the APCI mode than electrospray ionization. 13 HAcAms were separated by LC in 9.0 min, and the detection limits ranged from 7.6 to 19.7 ng/L. The SPE-LC/tqMS method was successfully applied to quantify 13 HAcAms in drinking water samples for the first time, and first indentified tribromoacetamide and chloroiodoacetamide as DBPs in drinking water. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Measurement strategy of the water leakage into a low pressure sodium boundary for a liquid metal reactor

    International Nuclear Information System (INIS)

    Hur, S.; Kim, D.H.; Seong, S.H.; Kim, S.O.

    2004-01-01

    This paper deals with the measurement strategy of a water leakage into sodium boundary for a liquid metal reactor. There are several methods including the chemical sensing method, pressure sensing methods, and non-destructive method including the acoustic monitoring technique to measure the leakage. As for the results of the analysis with respect to the event propagation characteristics, it has been recommended that the acoustic method has a capability to detect small and intermediate leaks within required response time of 10 seconds. A leak of one gram/sec could be currently detected within the required response time of 10 seconds with a high reliability. In the case of less than a one gram/sec leakage, the response time could not meet our requirements due to a complicated signal processing logic. Thus, the system configuration for a fast processing of a leak detection has been recommended. It is expected that this configuration of the leak detection system could reduce the response time due to the distributed and parallel processing scheme. (orig.)

  15. Specific and practicable assessment of urinary free cortisol by combination of automatic high-pressure liquid chromatography and radioimmunoassay

    International Nuclear Information System (INIS)

    Schoeneshoefer, M.; Fenner, A.; Altinok, G.; Dulce, H.J.

    1980-01-01

    An assay for the specific measurement of urinary free cortisol excretion is described. The method involves a simple solid-phase extraction, automatic high pressure liquid chromatography (HPLC) and radioimmunological quantification. The concurrent study on antigenically interfering compounds in the organic extract of urine revealed that non-specific immunoreactivities with a chromatographic behaviour very similar to cortisol are present in urine, which are not attributable to the steroids commonly studied for cross-reactivity. Non-chromatographed values are about twice as high as those chromatographed by HPLC. Correlation between them was significant (r=0.98). Precision and accuracy of the present method are within the range commonly achieved by radioimmunoassay methods. The normal range of urinary free cortisol excretion was found to be 28-117 nmol/24h (n=128). The present method, suitable for routine purposes, provides a basis for external quality control of urinary cortisol estimations, which is inadequate with the non-specific methods usually applied. (Auth.)

  16. Surface modification of polyimide (PI) film using water cathode atmospheric pressure glow discharge plasma

    International Nuclear Information System (INIS)

    Zheng Peichao; Liu Keming; Wang Jinmei; Dai Yu; Yu Bin; Zhou Xianju; Hao Honggang; Luo Yuan

    2012-01-01

    Highlights: ► Equipment called water cathode atmospheric pressure glow discharge was used to improve the hydrophilicity of polyimide films. ► The data shows good homogeneity and the variation trends of contact angles are different for polar and non-polar testing liquids. ► The thickness of liquid layer plays an important role in plasma processing and directly affects the treatment effect. ► Surface hydrophilicity after plasma treatment is improved partly due to the increase in the roughness. ► The hydrophilicity of polyimide films is still better than untreated ones after long-term storage. - Abstract: The industrial use of polyimide film is limited because of undesirable properties such as poor wettability. In the present paper, a new kind of equipment called water cathode atmospheric pressure glow discharge was used to improve the surface properties of polyimide films and made them useful to technical applications. The changes in hydrophilicity of modified polyimide film surfaces were investigated by contact angle, surface energy and water content measurements as a function of treatment time. The results obtained show good treatment homogeneity and that the variation trends of contact angles are different for polar and non-polar testing liquids, while surface energy and water content are significantly enhanced with the increase of treatment time until they achieve saturated values after 60 s plasma treatment. Also, the thickness of liquid layer plays an important role in plasma processing and directly affects the treatment effect. Changes in morphology of polyimide films were analyzed by atomic force microscope and the results indicate that surface hydrophilicity after plasma treatment are improved partly due to the increase in the roughness. In addition, polyimide films treated by plasma are subjected to an ageing process to determine the durability of plasma treatment. It is found that the hydrophilicity is still better than untreated ones though the

  17. Interfacial behavior of polar, weakly polar, and nonpolar compounds bound to activated carbons.

    Science.gov (United States)

    Gun'ko, V M; Turov, V V; Zarko, V I; Goncharuk, O V; Nychiporuk, Yu M; Kozynchenko, O P; Skubiszewska-Zięba, J; Leboda, R; Charmas, B; Balakin, D Yu; Ptushinskii, Yu G

    2013-08-15

    Detailed analysis of the interfacial behavior of water and weakly polar or nonpolar organics adsorbed alone or co-adsorbed onto activated carbons (AC) at different temperatures is a complex problem important for practical applications of adsorbents. Interaction of water, 1-decanol, and n-decane with AC possessing highly developed porosity (pore volume Vp≈1.4-2.3 cm(3)/g, specific surface area S(BET)≈1500-3500 m(2)/g) was studied over a broad temperature range using differential scanning calorimetry (DSC), thermoporometry, (1)H NMR spectroscopy, cryoporometry, and temperature-programmed desorption with mass-spectrometry control methods. Comparison of the pore size distributions (PSD) calculated using the DSC thermoporometry, NMR cryoporometry, and nitrogen adsorption isotherms allows us to determine localization of adsorbates in different pores, as well as changes in the PSD of AC due to freezing of adsorbates in pores. Theoretical calculations (using ab initio HF/6-31G(d,p), DFT B3LYP/6-31G(d,p), and PM7 methods) explain certain aspects of the interfacial behavior of water, decane, and decanol adsorbed onto AC that appear in the experimental data. Obtained results show strong temperature dependence (above and below the freezing point, Tf, of bulk liquids) of the interfacial behavior of adsorbates on the textural characteristics and hydrophilic/hydrophobic properties of AC and the adsorbate amounts that affect the distributions of adsorbates unfrozen at T

  18. 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.

  19. Stabilization of thin liquid films by repulsive van der waals force

    KAUST Repository

    Li, Erqiang; Vakarelski, Ivan Uriev; Chan, Derek Y C; Thoroddsen, Sigurdur T

    2014-01-01

    Using high-speed video recording of bubble rise experiments, we study the stability of thin liquid films trapped between a rising bubble and a surfactant-free liquid-liquid meniscus interface. Using different combinations of nonpolar oils and water

  20. In-Bore Liquid Injection for Barrel Cooling: Comparison of Liquid and Solid Additives Using Constant Breach Pressure Ideal Gun Calculations

    National Research Council Canada - National Science Library

    Kotlar, Anthony

    1999-01-01

    .... These calculations give limiting values for projectile muzzle kinetic energy (KE), assuming complete mixing of the liquid additive and the solid propellant This is a worst-case scenario for the new concept to reduce gun barrel heating...

  1. Soft ionization of saturated hydrocarbons, alcohols and nonpolar compounds by negative-ion direct analysis in real-time mass spectrometry.

    Science.gov (United States)

    Cody, Robert B; Dane, A John

    2013-03-01

    Large polarizable n-alkanes (approximately C18 and larger), alcohols, and other nonpolar compounds can be detected as negative ions when sample solutions are injected directly into the sampling orifice of the atmospheric pressure interface of the time-of-flight mass spectrometer with the direct analysis in real time (DART) ion source operating in negative-ion mode. The mass spectra are dominated by peaks corresponding to [M + O2]‾(•). No fragmentation is observed, making this a very soft ionization technique for samples that are otherwise difficult to analyze by DART. Detection limits for cholesterol were determined to be in the low nanogram range.

  2. Separation of benzene from alkanes using 1-ethyl-3-methylpyridinium ethylsulfate ionic liquid at several temperatures and atmospheric pressure: Effect of the size of the aliphatic hydrocarbons

    International Nuclear Information System (INIS)

    Gonzalez, Emilio J.; Calvar, Noelia; Gomez, Elena; Dominguez, Angeles

    2010-01-01

    The ionic liquid 1-ethyl-3-methylpyridinium ethylsulfate, [EMpy][ESO 4 ], was studied for the separation of benzene from aliphatic hydrocarbons (octane or nonane) by solvent extraction through the determination of the (liquid + liquid) equilibrium (LLE) of the ternary systems: {octane (1) + benzene (2) + [EMpy][ESO 4 ] (3)} and {nonane (1) + benzene (2) + [EMpy][ESO 4 ] (3)} at T = (283.15 and 298.15) K and atmospheric pressure. Binodal curves were determined using the 'cloud point' method, and tie-line compositions were obtained by density measurements. The values of selectivity and distribution coefficient, derived from the tie-line data, were used to decide if this ionic liquid can be used as potential solvent for the separation of benzene from aliphatic hydrocarbons using liquid extraction. These results were analyzed and compared to those previously reported for the systems {hexane + benzene + [EMpy][ESO 4 ]} and {heptane + benzene + [EMpy][ESO 4 ]}. The experimental results show that this ionic liquid is suitable for the extraction of benzene from mixtures containing octane and nonane. The consistency of tie-line data was ascertained by applying the Othmer-Tobias and Hand equations. The experimental results for the ternary systems were well correlated with the NRTL model. No literature data were found for the mixtures discussed in this paper.

  3. Isolation and purification of six iridoid glycosides from gardenia jasminoides fruit by medium-pressure liquid chromatography combined with macroporous resin chromatography.

    Science.gov (United States)

    Wang, Yun; Liu, Hui; Shen, Lifeng; Yao, Lan; Ma, Yinlian; Yu, Dingrong; Chen, Jianhong; Li, Puling; Chen, Ying; Zhang, Cun

    2015-12-01

    Gardeniae fructus is one of the most frequently used herbs in traditional Chinese medicine. In the present study, a process for the enrichment of six iridoid glycosides from Gardeniae fructus was developed using medium-pressure liquid chromatography combined with macroporous resin and reversed-phase chromatography. The purities of different fractions from Gardeniae fructus were assessed using quantitative high-performance liquid chromatography. After fractionation using HPD-100 column chromatography, a 30% ethanol fraction was selected based on high-performance liquid chromatography and liquid chromatography with mass spectrometry qualitative analysis to separate and purify. Based on the orientation analysis results, six compounds-deacetyl asperulosidic acid methyl ester, gardenoside, ixoroside, scandoside methyl ester, genipin-1-O-β-d-gentiobioside, and geniposide-were successfully isolated and purified in three to four combined steps from Gardeniae fructus. The purities of these compounds were found by high-performance liquid chromatography analysis to be 97.9, 98.1, 95.5, 96.3, 97.1, and 98.7%, respectively. Moreover, their structures were elucidated by NMR spectroscopy and liquid chromatography with tandem mass spectrometry. The separation process was highly efficient, rapid, and accurate, making it a potential approach for the large-scale production of iridoids in the laboratory and providing several marker compounds for quality control. This procedure may be meaningful for the purification of other natural products used in traditional Chinese medicine. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Tailored liquid chromatography-mass spectrometry analysis improves the coverage of the intracellular metabolome of HepaRG cells.

    Science.gov (United States)

    Cuykx, Matthias; Negreira, Noelia; Beirnaert, Charlie; Van den Eede, Nele; Rodrigues, Robim; Vanhaecke, Tamara; Laukens, Kris; Covaci, Adrian

    2017-03-03

    Metabolomics protocols are often combined with Liquid Chromatography-Mass Spectrometry (LC-MS) using mostly reversed phase chromatography coupled to accurate mass spectrometry, e.g. quadrupole time-of-flight (QTOF) mass spectrometers to measure as many metabolites as possible. In this study, we optimised the LC-MS separation of cell extracts after fractionation in polar and non-polar fractions. Both phases were analysed separately in a tailored approach in four different runs (two for the non-polar and two for the polar-fraction), each of them specifically adapted to improve the separation of the metabolites present in the extract. This approach improves the coverage of a broad range of the metabolome of the HepaRG cells and the separation of intra-class metabolites. The non-polar fraction was analysed using a C18-column with end-capping, mobile phase compositions were specifically adapted for each ionisation mode using different co-solvents and buffers. The polar extracts were analysed with a mixed mode Hydrophilic Interaction Liquid Chromatography (HILIC) system. Acidic metabolites from glycolysis and the Krebs cycle, together with phosphorylated compounds, were best detected with a method using ion pairing (IP) with tributylamine and separation on a phenyl-hexyl column. Accurate mass detection was performed with the QTOF in MS-mode only using an extended dynamic range to improve the quality of the dataset. Parameters with the greatest impact on the detection were the balance between mass accuracy and linear range, the fragmentor voltage, the capillary voltage, the nozzle voltage, and the nebuliser pressure. By using a tailored approach for the intracellular HepaRG metabolome, consisting of three different LC techniques, over 2200 metabolites can be measured with a high precision and acceptable linear range. The developed method is suited for qualitative untargeted LC-MS metabolomics studies. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Thermophysical and thermodynamic properties of ionic liquids over an extended pressure range: [bmim][NTf2] and [hmim][NTf2

    International Nuclear Information System (INIS)

    Gomes de Azevedo, R.; Esperanca, J.M.S.S.; Szydlowski, J.; Visak, Z.P.; Pires, P.F.; Guedes, H.J.R.; Rebelo, L.P.N.

    2005-01-01

    The current study focuses on 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide, [bmim][NTf 2 ], and 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide, [hmim][NTf 2 ]. The objective is to study the influence of pressure as well as that of the cation's alkyl chain length on several properties of this type of ionic liquids. Speed of propagation of ultrasound waves and densities in pure ionic liquids (ILs) as a function of temperature and pressure have been determined. Several other thermodynamic properties such as compressibilities, expansivities and heat capacities have been obtained. Speed of sound measurements have been carried out in broad ranges of temperature (283 < T/K < 323) and pressure (0.1 < p/MPa < 150), using a non-intrusive microcell. Density measurements have been performed at broad ranges of temperature (298 < T/K < 333) and pressure (0.1 < p/MPa < 60) using a vibrating tube densimeter. The pressure dependence of heat capacities, which is generally mild, is highly dependent on the curvature of the temperature dependence of density

  6. Investigation of hydrophobic substrates for solution residue analysis utilizing an ambient desorption liquid sampling-atmospheric pressure glow discharge microplasma.

    Science.gov (United States)

    Paing, Htoo W; Marcus, R Kenneth

    2018-03-12

    A practical method for preparation of solution residue samples for analysis utilizing the ambient desorption liquid sampling-atmospheric pressure glow discharge optical emission spectroscopy (AD-LS-APGD-OES) microplasma is described. Initial efforts involving placement of solution aliquots in wells drilled into copper substrates, proved unsuccessful. A design-of-experiment (DOE) approach was carried out to determine influential factors during sample deposition including solution volume, solute concentration, number of droplets deposited, and the solution matrix. These various aspects are manifested in the mass of analyte deposited as well as the size/shape of the product residue. Statistical analysis demonstrated that only those initial attributes were significant factors towards the emission response of the analyte. Various approaches were investigated to better control the location/uniformity of the deposited sample. Three alternative substrates, a glass slide, a poly(tetrafluoro)ethylene (PTFE) sheet, and a polydimethylsiloxane (PDMS)-coated glass slide, were evaluated towards the microplasma analytical performance. Co-deposition with simple organic dyes provided an accurate means of determining the location of the analyte with only minor influence on emission responses. The PDMS-coated glass provided the best performance by virtue of its providing a uniform spatial distribution of the residue material. This uniformity yielded an improved limits of detection by approximately 22× for 20 μL and 4 x for 2 μL over the other two substrates. While they operate by fundamentally different processes, this choice of substrate is not restricted to the LS-APGD, but may also be applicable to other AD methods such as DESI, DART, or LIBS. Further developments will be directed towards a field-deployable ambient desorption OES source for quantitative analysis of microvolume solution residues of nuclear forensics importance.

  7. Measurement of HbA1c in Gingival Crevicular Blood Using a High Pressure Liquid Chromatography Procedure

    Science.gov (United States)

    Pesce, Michael A.; Strauss, Shiela M.; Rosedale, Mary; Netterwald, Jane; Wang, Hangli

    2016-01-01

    Objectives To validate an ion exchange high-pressure liquid chromatography (HPLC) method for measuring glycated hemoglobin (HbA1c) in gingival crevicular blood (GCB) spotted on filter paper, for use in screening dental patients for diabetes. Methods We collected the GCB specimens for this study from the oral cavities of patients during dental visits, using rigorous strategies to obtain GCB that was as free of debris as possible. The analytical performance of the HPLC method was determined by measuring the precision, linearity, carryover, stability of HbA1c in GCB, and correlation of HbA1c results in GCB specimens with finger-stick blood (FSB) specimens spotted on filter paper. Results The coefficients of variation (CVs) for the inter- and intrarun precision of the method were less than 2.0%. Linearity ranged between 4.2% and 12.4%; carryover was less than 2.0%, and the stability of the specimen was 6 days at 4°C and as many as 14 days at −70°C. Linear regression analysis comparing the HbA1c results in GCB with FSB yielded a correlation coefficient of 0.993, a slope of 0.981, and an intercept of 0.13. The Bland-Altman plot showed no difference in the HbA1c results from the GCB and FSB specimens at normal, prediabetes, and diabetes HbA1c levels. Conclusion We validated an HPLC method for measuring HbA1c in GCB; this method can be used to screen dental patients for diabetes. PMID:26489673

  8. 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.

  9. Activity measurements of radioactive solutions by liquid scintillation counting and pressurized ionization chambers and Monte Carlo simulations of source-detector systems for metrology

    International Nuclear Information System (INIS)

    Amiot, Marie-Noelle

    2013-01-01

    The research works 'Activity measurements of radioactive solutions by liquid scintillation and pressurized ionization chambers and Monte Carlo simulations of source-detector systems' was presented for the graduation: 'Habilitation a diriger des recherches'. The common thread of both themes liquid scintillation counting and pressurized ionization chambers lies in the improvement of the techniques of radionuclide activity measurement. Metrology of ionization radiation intervenes in numerous domains, in the research, in the industry including the environment and the health, which are subjects of constant concern for the world population these last years. In this big variety of applications answers a large number of radionuclides of diverse disintegration scheme and under varied physical forms. The presented works realized within the National Laboratory Henri Becquerel have for objective to assure detector calibration traceability and to improve the methods of activity measurements within the framework of research projects and development. The improvement of the primary and secondary activity measurement methods consists in perfecting the accuracy of the measurements in particular by a better knowledge of the parameters influencing the detector yield. The works of development dealing with liquid scintillation counting concern mainly the study of the response of liquid scintillators to low energy electrons as well as their linear absorption coefficients using synchrotron radiation. The research works on pressurized ionization chambers consist of the study of their response to photons and electrons by experimental measurements compared to the simulation of the source-detector system using Monte Carlo codes. Besides, the design of a new type of ionization chamber with variable pressure is presented. This new project was developed to guarantee the precision of the amount of activity injected into the patient within the framework of diagnosis examination

  10. Liquid–liquid extraction of toluene from alkane with pyridinium based ionic liquid ([BPy][NO3] and [HPy][NO3]) at 298.15 K and atmospheric pressure

    International Nuclear Information System (INIS)

    Enayati, Mobin; Mokhtarani, Babak; Sharifi, Ali; Anvari, Sanam; Mirzaei, Mojtaba

    2016-01-01

    Highlights: • Extraction of toluene from alkane with pyridinium based ionic liquid was studied. • The ionic liquids [BPy][NO 3 ] and [HPy][NO 3 ] were used. • The effect of alkane chain length on selectivity of toluene was evaluated. • The effect of alkyl chain length of ionic liquids on toluene selectivity was investigated. • The experimental data were correlated with the NRTL model. - Abstract: The focus of this paper is to study the liquid−liquid extraction process for the separation of toluene from alkane employing the ionic liquids N-butylpyridinium nitrate, [BPy][NO 3 ], and N-hexylpyridinium nitrate, [HPy][NO 3 ], as a new solvents. New experimental data for the ternary systems of {[BPy][NO 3 ] (1) + heptane, or octane, or decane (2) + toluene (3)} and {[HPy][NO 3 ] (1) + heptane, or octane, or decane (2) + toluene (3)} at T = 298.15 K and atmospheric pressure are reported. The Othmer-Tobias and Hand correlation are examined to check the reliability of the experimental LLE data. The toluene distribution ratios and selectivity were calculated form the experimental data. The selectivity values are higher than unity which indicates the ILs, [BPy][NO 3 ] and [HPy][NO 3 ], used in this work are potential solvents to separate toluene from alkane. Besides, the effect of the alkane chain length in the selectivity values was evaluated. In addition, the result of the NRTL thermodynamic modeling shows, the experimental data were satisfactorily correlated.

  11. Density of Fe-3.5 wt% C liquid at high pressure and temperature and the effect of carbon on the density of the molten iron

    Science.gov (United States)

    Shimoyama, Yuta; Terasaki, Hidenori; Ohtani, Eiji; Urakawa, Satoru; Takubo, Yusaku; Nishida, Keisuke; Suzuki, Akio; Katayama, Yoshinori

    2013-11-01

    Carbon is a plausible light element candidate in the Earth’s outer core. We measured the density of liquid Fe-3.5 wt% C up to 6.8 GPa and 2200 K using an X-ray absorption method. The compression curve of liquid Fe-C was fitted using the third-order Birch-Murnaghan equation of state. The bulk modulus and its pressure derivative are K0,1500K = 55.3 ± 2.5 GPa and (dK0/dP)T = 5.2 ± 1.5, and the thermal expansion coefficient is α = 0.86 ± 0.04 × 10-4 K-1. The Fe-C density abruptly increases at pressures between 4.3 and 5.5 GPa in the range of present temperatures. Compared with the results of previous density measurements of liquid Fe-C, the effect of carbon on the density of liquid Fe shows a nonideal mixing behavior. The abrupt density increase and nonideal mixing behavior are important factors in determining the light element content in the Earth’s core.

  12. Interaction of slow electrons with high-pressure gases ('Quasi-liquids'): synthesis of our knowledge on slow electron-molecule interactions. Progress report

    International Nuclear Information System (INIS)

    McCorkle, D.L.; Christophorou, L.G.

    1985-01-01

    A crucial step in our efforts to develop not only a coherent picture of radiation interaction with matter, but also to understand radiation effects and mechanisms, as well as the effects of chemical pollutants and toxic compounds, is to relate the often abundant knowledge on isolated molecules (low pressure gases) to that on liquids or solids. To understand the roles of the physical and chemical properties of molecules in biological reactions, we must know how these isolated-molecule properties change as molecules are embedded in gradually thicker and thicker (denser and denser) gaseous and, finally, liquid environments. The work initiated by us both at the Physics Department of The University of Tennessee and at the Oak Ridge National Laboratory addresses itself to this question. At both places, high pressure (40 to approx.8000 kPa) electron swarm experiments are currently in operation yielding information as to the effects of the density and nature of the environment on fundamental electron-molecule interaction processes at densities intermediate to those corresponding to low pressure gases and liquids, and the gradual transition from isolated molecule to condensed phase behavior

  13. Effect of hydrostatic pressure on gas solubilization in micelles.

    Science.gov (United States)

    Meng, Bin; Ashbaugh, Henry S

    2015-03-24

    Molecular dynamics simulations of anionic sodium decylsulfate and nonionic pentaethylene glycol monodecyl ether micelles in water have been performed to examine the impact of hydrostatic pressure on argon solubilization as a function of pressure. The potential-of-mean force between the micelles and argon demonstrates that nonpolar gases are attracted to the interiors of both micelles. The affinity of argon for micelle interiors, however, decreases with increasing pressure as a result of the comparatively higher molar volume of argon inside assemblies. We evaluate solubility enhancement coefficients, which describe the drop in the solute chemical potential as a function of the micellized surfactant concentration, to quantify the impact of micellization on gas solubilization. While argon is similarly attracted to the hydrophobic cores of both micelles, the gas is more effectively sequestered within nonionic micelles compared with anionic micelles as a result of salting out by charged head groups and accompanying counterions. The solubility enhancement coefficients of both micelles decrease with increasing pressure, reflecting the changing forces observed in the potentials-of-mean force. An analytical liquid drop model is proposed to describe the pressure dependence of argon solubilization within micelles that captures the simulation solubility enhancement coefficients after fitting an effective micelle radius for each surfactant.

  14. Effect of dispersive long-range corrections to the pressure tensor: The vapour-liquid interfacial properties of the Lennard-Jones system revisited

    Energy Technology Data Exchange (ETDEWEB)

    Martínez-Ruiz, F. J.; Blas, F. J., E-mail: felipe@uhu.es [Departamento de Física Aplicada, Universidad de Huelva, 21071 Huelva (Spain); Centro de Investigación de Física Teórica y Matemática, Universidad de Huelva, 21071 Huelva (Spain); Mendiboure, B. [Laboratoire des Fluides Complexes et leurs Réservoirs, UMR5150, Université de Pau et des Pays de l’Adour, B. P. 1155, Pau Cedex 64014 (France); Moreno-Ventas Bravo, A. I. [Centro de Investigación de Física Teórica y Matemática, Universidad de Huelva, 21071 Huelva (Spain); Departamento de Geología, Facultad de Ciencias Experimentales, Universidad de Huelva, 21071 Huelva (Spain)

    2014-11-14

    We propose an extension of the improved version of the inhomogeneous long-range corrections of Janeček [J. Phys. Chem. B 110, 6264–6269 (2006)], presented recently by MacDowell and Blas [J. Chem. Phys. 131, 074705 (2009)] to account for the intermolecular potential energy of spherical, rigid, and flexible molecular systems, to deal with the contributions to the microscopic components of the pressure tensor due to the dispersive long-range corrections. We have performed Monte Carlo simulations in the canonical ensemble to obtain the interfacial properties of spherical Lennard-Jones molecules with different cutoff distances, r{sub c} = 2.5, 3, 4, and 5σ. In addition, we have also considered cutoff distances r{sub c} = 2.5 and 3σ in combination with the inhomogeneous long-range corrections proposed in this work. The normal and tangential microscopic components of the pressure tensor are obtained using the mechanical or virial route in combination with the recipe of Irving and Kirkwood, while the macroscopic components are calculated using the Volume Perturbation thermodynamic route proposed by de Miguel and Jackson [J. Chem. Phys. 125, 164109 (2006)]. The vapour-liquid interfacial tension is evaluated using three different procedures, the Irving-Kirkwood method, the difference between the macroscopic components of the pressure tensor, and the Test-Area methodology. In addition to the pressure tensor and the surface tension, we also obtain density profiles, coexistence densities, vapour pressure, critical temperature and density, and interfacial thickness as functions of temperature, paying particular attention to the effect of the cutoff distance and the long-range corrections on these properties. According to our results, the main effect of increasing the cutoff distance (at fixed temperature) is to sharpen the vapour-liquid interface, to decrease the vapour pressure, and to increase the width of the biphasic coexistence region. As a result, the interfacial

  15. Effect of dispersive long-range corrections to the pressure tensor: The vapour-liquid interfacial properties of the Lennard-Jones system revisited

    International Nuclear Information System (INIS)

    Martínez-Ruiz, F. J.; Blas, F. J.; Mendiboure, B.; Moreno-Ventas Bravo, A. I.

    2014-01-01

    We propose an extension of the improved version of the inhomogeneous long-range corrections of Janeček [J. Phys. Chem. B 110, 6264–6269 (2006)], presented recently by MacDowell and Blas [J. Chem. Phys. 131, 074705 (2009)] to account for the intermolecular potential energy of spherical, rigid, and flexible molecular systems, to deal with the contributions to the microscopic components of the pressure tensor due to the dispersive long-range corrections. We have performed Monte Carlo simulations in the canonical ensemble to obtain the interfacial properties of spherical Lennard-Jones molecules with different cutoff distances, r c = 2.5, 3, 4, and 5σ. In addition, we have also considered cutoff distances r c = 2.5 and 3σ in combination with the inhomogeneous long-range corrections proposed in this work. The normal and tangential microscopic components of the pressure tensor are obtained using the mechanical or virial route in combination with the recipe of Irving and Kirkwood, while the macroscopic components are calculated using the Volume Perturbation thermodynamic route proposed by de Miguel and Jackson [J. Chem. Phys. 125, 164109 (2006)]. The vapour-liquid interfacial tension is evaluated using three different procedures, the Irving-Kirkwood method, the difference between the macroscopic components of the pressure tensor, and the Test-Area methodology. In addition to the pressure tensor and the surface tension, we also obtain density profiles, coexistence densities, vapour pressure, critical temperature and density, and interfacial thickness as functions of temperature, paying particular attention to the effect of the cutoff distance and the long-range corrections on these properties. According to our results, the main effect of increasing the cutoff distance (at fixed temperature) is to sharpen the vapour-liquid interface, to decrease the vapour pressure, and to increase the width of the biphasic coexistence region. As a result, the interfacial thickness

  16. Conversion of proteins from a non-polarized to an apical secretory pattern in MDCK cells

    International Nuclear Information System (INIS)

    Vogel, Lotte K.; Larsen, Jakob E.; Hansen, Martin; Truffer, Renato

    2005-01-01

    Previously it was shown that fusion proteins containing the amino terminus of an apical targeted member of the serpin family fused to the corresponding carboxyl terminus of the non-polarized secreted serpin, antithrombin, are secreted mainly to the apical side of MDCK cells. The present study shows that this is neither due to the transfer of an apical sorting signal from the apically expressed proteins, since a sequence of random amino acids acts the same, nor is it due to the deletion of a conserved signal for correct targeting from the non-polarized secreted protein. Our results suggest that the polarity of secretion is determined by conformational sensitive sorting signals

  17. Designs of infrared nonpolarizing beam splitters with a Ag layer in a glass cube.

    Science.gov (United States)

    Shi, Jin Hui; Wang, Zheng Ping

    2008-05-10

    A novel design of a nonpolarizing beam splitter with a Ag layer in a cube was proposed and optimized, based on the needle optimization. The digital simulations of the reflectance and reflection-induced retardance were presented. The simulation results showed that both the amplitude and the phase characteristics of the nonpolarizing beam splitter could realize the design targets. The difference between the simulated and the target reflectance of 50% is less than 0.4% and the simulated and the reflection-induced retardance is less than 0.62 degrees in the 1260 -1360 nm range for both p and s components.

  18. Nonpolarizing beam splitter designed by frustrated total internal reflection inside a glass cube.

    Science.gov (United States)

    Xu, Xueke; Shao, Jianda; Fan, Zhengxiu

    2006-06-20

    A method for the design of an all-dielectric nonpolarizing prism beam splitter utilizing the principle of frustrated total internal reflection is reported. The nonpolarizing condition for a prism beam splitter is discussed, and some single layer design examples are elaborated. The concept can be applied to a wide range of wavelengths and arbitrary transmittance values, and with the help of a computer design program examples of 400-700 nm, T(p)=T(s)=0.5+/-0.01, with incident angles of 45 degrees and 62 degrees are given. In addition, the sensitivity and application of the design are also discussed.

  19. Design and analysis of metal-dielectric nonpolarizing beam splitters in a glass cube.

    Science.gov (United States)

    Shi, Jin Hui; Guan, Chun Ying; Wang, Zheng Ping

    2009-06-20

    A novel design of a 25-layer metal-dielectric nonpolarizing beam splitter in a cube is proposed by use of the optimization method and is theoretically investigated. The simulations of the reflectance and differential phases induced by reflection and transmission are presented. The simulation results reveal that both the amplitude and the phase characteristics of the nonpolarizing beam splitter could realize the design targets, the differences between the simulated and the target reflectance of 50% are less than 2%, and the differential phases are less than 3 degrees in the range of 530 nm-570 nm for both p and s components.

  20. Design and analysis of all-dielectric broadband nonpolarizing parallel-plate beam splitters.

    Science.gov (United States)

    Wang, Wenliang; Xiong, Shengming; Zhang, Yundong

    2007-06-01

    Past research on the all-dielectric nonpolarizing beam splitter is reviewed. With the aid of the needle thin-film synthesis method and the conjugate graduate refine method, three different split ratio nonpolarizing parallel-plate beam splitters over a 200 nm spectral range centered at 550 nm with incidence angles of 45 degrees are designed. The chosen materials component and the initial stack are based on the Costich and Thelen theories. The results of design and analysis show that the designs maintain a very low polarization ratio in the working range of the spectrum and has a reasonable angular field.

  1. Optical Interference Coatings Design Contest 2007: triple bandpass filter and nonpolarizing beam splitter.

    Science.gov (United States)

    Tilsch, Markus; Hendrix, Karen

    2008-05-01

    A triple bandpass filter (28 solutions received) and a nonpolarizing beam splitter (23 solutions received) were the subjects of the design contest held in conjunction with the 2007 Optical Interference Coatings topical meeting of the Optical Society of America. Fifteen designers participated using a wide spectrum of design approaches and optimization strategies to create the submissions. The results differ significantly, but all meet the contest requirements. Fabien Lemarchand wins both contests by submitting the thinnest (6254 nm) triple bandpass design and the widest (61.7 nm) nonpolarizing beam-splitter design. Michael Trubetskov is in second place, followed by Vladimir Pervak in both contests. The submitted designs are described and evaluated.

  2. Temperature Dependence of the Inhibition of Positronium by Chlorine- Substituted Hydrocarbons in Non-Polar Liquids

    DEFF Research Database (Denmark)

    Wikander, G.; Mogensen, O.E.; Pedersen, Niels Jørgen

    1984-01-01

    Positron annihilation lifetime spectra were measured for solutions of 1,2,3,5-C6H2Cl4 in hexane, toluene, m-xylene and mesitylene, CCl4 in hexane and toluene, and C2HCl3 in n-hexane for concentrations below 1 M and at various temperatures between −30°C and 67°C. The Ps inhibition by C6H2Cl4 was r...

  3. Liquid waste sampling device

    International Nuclear Information System (INIS)

    Kosuge, Tadashi

    1998-01-01

    A liquid pumping pressure regulator is disposed on the midway of a pressure control tube which connects the upper portion of a sampling pot and the upper portion of a liquid waste storage vessel. With such a constitution, when the pressure in the sampling pot is made negative, and liquid wastes are sucked to the liquid pumping tube passing through the sampling pot, the difference between the pressure on the entrance of the liquid pumping pressure regulator of the pressure regulating tube and the pressure at the bottom of the liquid waste storage vessel is made constant. An opening degree controlling meter is disposed to control the degree of opening of a pressure regulating valve for sending actuation pressurized air to the liquid pumping pressure regulator. Accordingly, even if the liquid level of liquid wastes in the liquid waste storage vessel is changed, the height for the suction of the liquid wastes in the liquid pumping tube can be kept constant. With such procedures, sampling can be conducted correctly, and the discharge of the liquid wastes to the outside can be prevented. (T.M.)

  4. An application of liquid sublayer dryout mechanism to the prediction of critical heat flux under low pressure and low velocity conditions in round tubes

    International Nuclear Information System (INIS)

    Lee, Kwang-Won; Yang, Jae-Young; Baik, Se-Jin

    1997-01-01

    Based on several experimental evidences for nucleate boiling in annular film and the existence of residual liquid film flow rate at the critical heat flux (CHF) location, the liquid sublayer dryout (LSD) mechanism under annular film is firstly introduced to evaluate the CHF data at low pressure and low velocity (LPLV) conditions, which would not be predicted by a normal annular film dryout (AFD) model. In this study, the CHF occurrence due to annular film separation or breaking down is phenomenologically modelled by applying the LSD mechanism to this situation. In this LSD mechanism, the liquid sublayer thickness, the incoming liquid velocity to the liquid sublayer, and the axial distance from the onset of annular flow to the CHF location are used as the phenomena-controlling parameters. From the model validation on the 1406 CHF data points ranging over P = 0.1 - 2 MPa, G = 4 - 499 kg/m 2 s, L/D = 4 - 402, most of CHF data (more than 1000 points) are predicted within ±30% error bounds by the LSD mechanism. However, some calculation results that critical qualities are less than 0.4 are considerably overestimated by this mechanism. These overpredictions seem to be caused by inadequate CHF mechanism classification criteria and an insufficient consideration of the flow instability effect on CHF. Further studies for a new classification criterion screening the CHF data affected by flow instabilities and a new bubble detachment model for LPLV conditions are needed to improve the model accuracy. (author)

  5. Drop-on-demand sample introduction system coupled with the flowing atmospheric-pressure afterglow for direct molecular analysis of complex liquid microvolume samples.

    Science.gov (United States)

    Schaper, J Niklas; Pfeuffer, Kevin P; Shelley, Jacob T; Bings, Nicolas H; Hieftje, Gary M

    2012-11-06

    One of the fastest developing fields in analytical spectrochemistry in recent years is ambient desorption/ionization mass spectrometry (ADI-MS). This burgeoning interest has been due to the demonstrated advantages of the method: simple mass spectra, little or no sample preparation, and applicability to samples in the solid, liquid, or gaseous state. One such ADI-MS source, the flowing atmospheric-pressure afterglow (FAPA), is capable of direct analysis of solids just by aiming the source at the solid surface and sampling the produced ions into a mass spectrometer. However, direct introduction of significant volumes of liquid samples into this source has not been possible, as solvent loads can quench the afterglow and, thus, the formation of reagent ions. As a result, the analysis of liquid samples is preferably carried out by analyzing dried residues or by desorbing small amounts of liquid samples directly from the liquid surface. In the former case, reproducibility of sample introduction is crucial if quantitative results are desired. In the present study, introduction of liquid samples as very small droplets helps overcome the issues of sample positioning and reduced levels of solvent intake. A recently developed "drop-on-demand" (DOD) aerosol generator is capable of reproducibly producing very small volumes of liquid (∼17 pL). In this paper, the coupling of FAPA-MS and DOD is reported and applications are suggested. Analytes representing different classes of substances were tested and limits of detections were determined. Matrix tolerance was investigated for drugs of abuse and their metabolites by analyzing raw urine samples and quantification without the use of internal standards. Limits of detection below 2 μg/mL, without sample pretreatment, were obtained.

  6. Long-duration nano-second single pulse lasers for observation of spectra from bulk liquids at high hydrostatic pressures

    International Nuclear Information System (INIS)

    Thornton, Blair; Sakka, Tetsuo; Masamura, Tatsuya; Tamura, Ayaka; Takahashi, Tomoko; Matsumoto, Ayumu

    2014-01-01

    The influence of laser pulse duration on the spectral emissions observed from bulk ionic solutions has been investigated for hydrostatic pressures between 0.1 and 30 MPa. Transient pressure, shadowgraph imaging and spectroscopic measurements were performed for single pulses of duration 20 and 150 ns. The transient pressure measurements show that for hydrostatic pressures up to 30 MPa, propagation of the high-pressure shockwave generated by the focused laser causes the local pressure to reduce below ambient levels during the time frame that spectroscopic measurements can be made. The pressure impulse and subsequent reduction in pressure are larger, with the latter lasting longer for the 150 ns pulse compared to a 20 ns pulse of the same energy. The 150 ns pulse generates larger cavities with significant enhancement of the spectral emissions observed compared to the 20 ns duration pulse for pressures up to 30 MPa. The results demonstrate that laser-induced breakdown using a long ns duration pulse offers an advantage over conventional, short ns duration pulses for the analysis of bulk ionic solutions at hydrostatic pressures between 0.1 and 30 MPa. - Highlights: • Long-ns-duration laser pulses enhance the spectra observed from bulk solutions. • Laser-induced shockwaves momentarily reduce pressures to below ambient levels. • 150 ns pulses generate larger cavities than 20 ns pulses of the same energy. • Hydrostatic pressures < 30 MPa have no significant effect on the observed spectra

  7. Comparison of MHD pressure losses of liquid-lithium flows in coaxial and parallel ducts, passing through strong transverse magnetic fields

    International Nuclear Information System (INIS)

    Trommer, G.

    1979-08-01

    This report deals with theoretical calculations of MHD pressure losses of liquid-lithium flows in tubes of circular cross-section exposed to strong magnetic fields. Some simplifying assumptions were introduced, yielding an analytical solution which allows the pressure drop and losses in double tubes of coaxial geometry to be compared with those in normal flow pipes. The investigations show that coaxial ducts require much more pumping power than normal ones under similar conditions. This great difference of the properties of the two duct types will decrease if the pipes are embedded in materials of good electrical conductivity. In this case the normal duct will afford a drastic increase in the pressure drop, while the coaxial one will be nearly unaffected. But even under these conditions the losses of the latter will dominate. (orig.)

  8. Highly informative multiclass profiling of lipids by ultra-high performance liquid chromatography - Low resolution (quadrupole) mass spectrometry by using electrospray ionization and atmospheric pressure chemical ionization interfaces.

    Science.gov (United States)

    Beccaria, Marco; Inferrera, Veronica; Rigano, Francesca; Gorynski, Krzysztof; Purcaro, Giorgia; Pawliszyn, Janusz; Dugo, Paola; Mondello, Luigi

    2017-08-04

    A simple, fast, and versatile method, using an ultra-high performance liquid chromatography system coupled with a low resolution (single quadrupole) mass spectrometer was optimized to perform multiclass lipid profiling of human plasma. Particular attention was made to develop a method suitable for both electrospray ionization and atmospheric pressure chemical ionization interfaces (sequentially in positive- and negative-ion mode), without any modification of the chromatographic conditions (mobile phase, flow-rate, gradient, etc.). Emphasis was given to the extrapolation of the structural information based on the fragmentation pattern obtained using atmospheric pressure chemical ionization interface, under each different ionization condition, highlighting the complementary information obtained using the electrospray ionization interface, of support for related molecule ions identification. Furthermore, mass spectra of phosphatidylserine and phosphatidylinositol obtained using the atmospheric pressure chemical ionization interface are reported and discussed for the first time. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Standard Practice for Installation, Inspection, and Maintenance of Valve-body Pressure-relief Methods for Geothermal and Other High-Temperature Liquid Applications

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2003-01-01

    1.1 This practice covers installation, inspection, and maintenance of valve body cavity pressure relief methods for valves used in geothermal and other high-temperature liquid service. The valve type covered by this practice is a design with an isolated body cavity such that when the valve is in either the open or closed position pressure is trapped in the isolated cavity, and there is no provision to relieve the excess pressure internally. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  10. Liquid sampling-atmospheric pressure glow discharge optical emission spectroscopy detection of laser ablation produced particles: A feasibility study

    International Nuclear Information System (INIS)

    Quarles, C. Derrick; Gonzalez, Jhanis; Choi, Inhee; Ruiz, Javier; Mao, Xianglei; Marcus, R. Kenneth; Russo, Richard E.

    2012-01-01

    The use of a liquid sampling-atmospheric pressure glow discharge (LS-APGD) microplasma source as an alternative to conventional inductively coupled plasma (ICP) detection of laser ablation (LA) produced particles using a Nd:YAG laser at 1064 nm is demonstrated. This configuration utilizes a 180° geometry, which is different from the 40° geometry that was used to ionize ablated particles followed by mass spectrometric detection. The use of a hollow counter electrode (nickel, 0.3 cm o.d., 0.1 cm i.d.) was implemented to introduce ablated particles directly into the APGD plasma with helium as a carrier gas. The LS-APGD source was optimized using ablated copper as the test sample (helium carrier gas flow rate (0.30 L min −1 He), discharge current (60 mA), laser power (44 mJ), and solution electrode sheath gas (0.2 L min −1 He) and solution flow rates (10 μL min −1 5% HNO 3 )). Standard brass samples having known Zn/Cu percentages were ablated and analyzed using the LS-APGD source. As a comparison, the established technique of laser-induced breakdown spectroscopy (LIBS) was used to analyze the same set of brass standards under similar ablation conditions to the LS-AGPD measurements, yielding comparable results. The Zn/Cu ratio results for the LS-APGD and LIBS measurements showed good similarity to previous measurements using ICP-MS detection. The performance of the LS-APGD–OES microplasma, comparable to well established methods, with lower capital and operational overhead expenses, suggests a great deal of promise as an analytical excitation source. - Highlights: ► Particles formed by laser ablation are readily introduced to the LS-APGD microplasma. ► The low power microplasma has sufficient energy to vaporize laser produced particles. ► Qualitative analysis of brass alloys is performed using a simple OES ratio method. ► The qualitative performance of the LS-APGD microplasma is on-par with LIBS analysis.

  11. Pressurized liquid extraction-gas chromatography-mass spectrometry analysis of fragrance allergens, musks, phthalates and preservatives in baby wipes.

    Science.gov (United States)

    Celeiro, Maria; Lamas, J Pablo; Garcia-Jares, Carmen; Llompart, Maria

    2015-03-06

    Baby wipes and wet toilet paper are specific hygiene care daily products used on newborn and children skin. These products may contain complexes mixtures of harmful chemicals. A method based on pressurized liquid extraction (PLE) followed by gas chromatography-mass spectrometry (GC-MS) has been developed for the simultaneous determination of sixty-five chemical compounds (fragrance allergens, preservatives, musks, and phthalates) in wipes and wet toilet paper for children. These compounds are legislated in Europe according Regulation EC No 1223/2009, being twelve of them banned for their use in cosmetics, and one of them, 3-iodo-2-propynyl butylcarbamate (IPBC), is banned in products intended for children under 3 years. Also, propyl-, and butylparaben will be prohibited in leave-on cosmetic products designed for application on the nappy area of children under 3 years from April 2015. PLE is a fast, simple, easily automated technique, which permits to integrate a clean-up step during the extraction process reducing analysis time and stages. The proposed PLE-based procedure was optimized on real non-spiked baby wipe samples by means of experimental design to study the influence on extraction of parameters such as extraction solvent, temperature, extraction time, and sorbent type. Under the selected conditions, the method was validated showing satisfactory linearity, and intra-day, and inter-day precision. Recoveries were between 80-115% for most of the compounds with relative standard deviations (RSD) lower than 15%. Finally, twenty real samples were analyzed. Thirty-six of the target analytes were detected, highlighting the presence of phenoxyethanol in all analyzed samples at high concentration levels (up to 0.8%, 800μgg(-1)). Methyl paraben (MeP), and ethyl paraben (EtP) were found in 40-50% of the samples, and the recently banned isobutyl paraben (iBuP) and isopropyl paraben (iPrP), were detected in one and seven samples, respectively, at concentrations between

  12. Development of a passive liquid valve (PLV) utilizing a pressure equilibrium phenomenon on the centrifugal microfluidic platform.

    Science.gov (United States)

    Al-Faqheri, Wisam; Ibrahim, Fatimah; Thio, Tzer Hwai Gilbert; Bahari, Norulain; Arof, Hamzah; Rothan, Hussin A; Yusof, Rohana; Madou, Marc

    2015-02-25

    In this paper, we propose an easy-to-implement passive liquid valve (PLV) for the microfluidic compact-disc (CD). This valve can be implemented by introducing venting chambers to control the air flow of the source and destination chambers. The PLV mechanism is based on equalizing the main forces acting on the microfluidic CD (i.e., the centrifugal and capillary forces) to control the burst frequency of the source chamber liquid. For a better understanding of the physics behind the proposed PLV, an analytical model is described. Moreover, three parameters that control the effectiveness of the proposed valve, i.e., the liquid height, liquid density, and venting chamber position with respect to the CD center, are tested experimentally. To demonstrate the ability of the proposed PLV valve, microfluidic liquid switching and liquid metering are performed. In addition, a Bradford assay is performed to measure the protein concentration and evaluated in comparison to the benchtop procedure. The result shows that the proposed valve can be implemented in any microfluidic process that requires simplicity and accuracy. Moreover, the developed valve increases the flexibility of the centrifugal CD platform for passive control of the liquid flow without the need for an external force or trigger.

  13. Development of a Passive Liquid Valve (PLV Utilizing a Pressure Equilibrium Phenomenon on the Centrifugal Microfluidic Platform

    Directory of Open Access Journals (Sweden)

    Wisam Al-Faqheri

    2015-02-01

    Full Text Available In this paper, we propose an easy-to-implement passive liquid valve (PLV for the microfluidic compact-disc (CD. This valve can be implemented by introducing venting chambers to control the air flow of the source and destination chambers. The PLV mechanism is based on equalizing the main forces acting on the microfluidic CD (i.e., the centrifugal and capillary forces to control the burst frequency of the source chamber liquid. For a better understanding of the physics behind the proposed PLV, an analytical model is described. Moreover, three parameters that control the effectiveness of the proposed valve, i.e., the liquid height, liquid density, and venting chamber position with respect to the CD center, are tested experimentally. To demonstrate the ability of the proposed PLV valve, microfluidic liquid switching and liquid metering are performed. In addition, a Bradford assay is performed to measure the protein concentration and evaluated in comparison to the benchtop procedure. The result shows that the proposed valve can be implemented in any microfluidic process that requires simplicity and accuracy. Moreover, the developed valve increases the flexibility of the centrifugal CD platform for passive control of the liquid flow without the need for an external force or trigger.

  14. Selective Extraction of Organic Contaminants from Soil Using Pressurised Liquid Extraction

    Directory of Open Access Journals (Sweden)

    Rozita Osman

    2013-01-01

    Full Text Available This study focuses on the application of sorbents in pressurised liquid extraction (PLE cell to establish a selective extraction of a variety of organic contaminants (polycyclic aromatic hydrocarbons (PAHs, chlorpyrifos, phenol, pentachlorophenol, and sterols from soil. The selectivity and efficiency of each sorbent depend on the properties of the material, extracting solvent, capacity factor, organic compounds of interest, and PLE operating parameters (temperature, pressure, and extraction time. Several sorbents (silica, alumina, and Florisil were evaluated and with the proper choice of solvents, polar and nonpolar compounds were successfully separated in two fractions. Nonpolar compounds (PAHs, chlorpyrifos, and pentachlorophenol were recovered in the first fraction using a polar sorbent such as Florisil or alumina, and n-hexane as eluting solvent, while more polar compounds (phenol and sterols were recovered in the second fraction using methanol. Silica (5 g was found to be effective for selective extraction with the satisfactory recoveries for all compounds (PAHs from 87.1–96.2%, chlorpyrifos 102.9%, sterols from 93.7–100.5%, phenol 91.9%, and pentachlorophenol 106.2%. The efficiency and precision of this extraction approach and the existing EPA Method 3545 were compared.

  15. Recognition and measurement gas-liquid two-phase flow in a vertical concentric annulus at high pressures

    Science.gov (United States)

    Li, Hao; Sun, Baojiang; Guo, Yanli; Gao, Yonghai; Zhao, Xinxin

    2018-02-01

    The air-water flow characteristics under pressure in the range of 1-6 MPa in a vertical annulus were evaluated in this report. Time-resolved bubble rising velocity and void fraction were also measured using an electrical void fraction meter. The results showed that the pressure has remarkable effect on the density, bubble size and rise velocity of the gas. Four flow patterns (bubble, cap-bubble, cap-slug, and churn) were also observed instead of Taylor bubble at high pressure. Additionally, the transition process from bubble to cap-bubble was investigated at atmospheric and high pressures, respectively. The results revealed that the flow regime transition criteria for atmospheric pressure do not work at high pressure, hence a new flow regime transition model for annular flow channel geometry was developed to predict the flow regime transition, which thereafter exhibited high accuracy at high pressure condition.

  16. Polarisation of the spontaneous emission from nonpolar and semipolar InGaN quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Schade, Lukas; Schwarz, Ulrich [Department of Microsystems Engineering, University of Freiburg (IMTEK) (Germany); Fraunhofer Institute for Applied Solid State Physics (IAF) (Germany); Ploch, Simon; Wernicke, Tim [Institute of Solid State Physics, Technical University Berlin (Germany); Knauer, Arne; Hoffmann, Veit; Weyers, Markus [Ferdinand-Braun-Institute (FBH) (Germany); Kneissl, Michael [Institute of Solid State Physics, Technical University Berlin (Germany); Ferdinand-Braun-Institute (FBH) (Germany)

    2011-07-01

    Spontaneously emitted light stemming from semipolar and nonpolar InGaN quantum wells is polarized. This property is a consequence of the broken in-plane symmetry of non c-plane wurtzite quantum wells. We studied the polarized photoluminescence of semipolar and nonpolar InGaN/InGaN multi quantum wells grown on low defect density GaN substrates with a setup for confocal microscopy. For excitation of charge carriers we use a 375 nm diode laser. The photoluminescence is collected with an objective of small NA, to avoid polarisation scrambling, and analyzed with a broadband polarizer and a spectrometer. The experimental results are compared to k.p band structure calculations for semipolar and nonpolar InGaN quantum wells. These simulations provide the polarisation degree of the confined states of the valence band and their energetic splitting. Next, from the thermal occupation the polarized spectra are calculated. The comparison with experimental results allows the determination of the valence subband splitting. Our experiments show a splitting of the two topmost valence subbands in nonpolar direction which is larger than predicted.

  17. Polarization-dependent photoluminescence studies of semipolar and nonpolar InGaN quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Schade, Lukas; Schwarz, Ulrich [IAF, Freiburg (Germany); Wernicke, Tim; Weyers, Markus [FBH, Berlin (Germany); Kneissl, Michael [FBH, Berlin (Germany); Institute of Solid State Physics, TU Berlin (Germany)

    2010-07-01

    Light emitted from optical devices based on semi- and nonpolar GaN quantum well (QW) structures is partially or totally polarized, as a consequence of crystal symmetry and band structure. This can be an additional advantage over polar (0001)GaN in specific applications, e.g. in LED backlighting. Fundamentally, the polarized emission stems from breaking the isotropic symmetry of the hexagonal c-plane, resulting in two discrete semi- and nonpolar directions (parallel and normal to the projection of (0001)). We use the k.p method to simulate the crystal-direction dependent emission. The resulting transition matrix elements assign a specific (partial) polarization for each subband. The thermal occupation of the subbands results in a temperature dependent effective polarization of the light emission. We study MOVPE grown homoepitactical polar, semi- and nonpolar samples, measuring the polarization properties of the resonantly excited photoluminescence from the QW. With the complete polarization of the subbands for nonpolar devices it is possible to measure the energetic difference of the first two valence band levels. In contrast to our calculations we find a higher degree of polarization also in semipolar directions. A possible explanation could be a higher energetic subband difference than computed.

  18. Passive sampling in regulatory chemical monitoring of nonpolar organic compounds in the aquatic environment

    NARCIS (Netherlands)

    Booij, K.; Robinson, C.D.; Burgess, R.M.; Mayer, P.; Roberts, C.A.; Ahrens, L.; Allan, I.J.; Brant, J.; Jones, L.; Kraus, U.R.; Larsen, M.M.; Lepom, P.; Petersen, J.; Pröfrock, D.; Roose, P.; Schäfer, S.; Smedes, F.; Tixier, C.; Vorkamp, K.; Whitehouse, P.

    2016-01-01

    We reviewed compliance monitoring requirements in the EuropeanUnion, the United States, and the Oslo-Paris Convention for the protection of themarine environment of the North-East Atlantic, and evaluated if these are met bypassive sampling methods for nonpolar compounds. The strengths

  19. Role of the electronegativity for the interface properties of non-polar heterostructures

    KAUST Repository

    Nazir, Safdar; Singh, Nirpendra; Kahaly, M. Upadhyay; Schwingenschlö gl, Udo

    2012-01-01

    Density functional theory is used to investigate the interfaces in the non-polar ATiO 3/SrTiO 3 (A=Pb, Ca, Ba) heterostructures. All TiO 2-terminated interfaces show an insulating behavior. By reduction of the O content in the AO, SrO, and TiO 2

  20. Temperature programmed retention indices : calculation from isothermal data Part 2: Results with nonpolar columns

    NARCIS (Netherlands)

    Curvers, J.M.P.M.; Rijks, J.A.; Cramers, C.A.M.G.; Knauss, K.; Larson, P.

    1985-01-01

    The procedure for calculating linear temperature programmed indices as described in part 1 has been evaluated using five different nonpolar columns, with OV-1 as the stationary phase. For fourty-three different solutes covering five different classes of components, including n-alkanes and

  1. The influence of non-polar lipids on tear film dynamics

    KAUST Repository

    Bruna, M.; Breward, C.  J.  W.

    2014-01-01

    © 2014 Cambridge University Press. In this paper we examine the effect that physiological non-polar lipids, residing on the surface of an aqueous tear film, have on the film evolution. In our model we track the evolution of the thickness of the non

  2. 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

  3. Surface chemistry and electronic structure of nonpolar and polar GaN films

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Monu; Krishna, T.C. Shibin; Aggarwal, Neha; Gupta, Govind, E-mail: govind@nplindia.org

    2015-08-01

    Highlights: • Surface chemistry and electronic structure of polar and nonpolar GaN is reported. • Influence of polarization on electron affinity of p & np GaN films is investigated. • Correlation between surface morphology and polarity has been deduced. - Abstract: Photoemission and microscopic analysis of nonpolar (a-GaN/r-Sapphire) and polar (c-GaN/c-Sapphire) epitaxial gallium nitride (GaN) films grown via RF-Molecular Beam Epitaxy is reported. The effect of polarization on surface properties like surface states, electronic structure, chemical bonding and morphology has been investigated and correlated. It was observed that polarization lead to shifts in core level (CL) as well as valence band (VB) spectra. Angle dependent X-ray Photoelectron Spectroscopic analysis revealed higher surface oxide in polar GaN film compared to nonpolar GaN film. On varying the take off angle (TOA) from 0° to 60°, the Ga−O/Ga−N ratio varied from 0.11–0.23 for nonpolar and 0.17–0.36 for polar GaN film. The nonpolar film exhibited N-face polarity while Ga-face polarity was perceived in polar GaN film due to the inherent polarization effect. Polarization charge compensated surface states were observed on the polar GaN film and resulted in downward band bending. Ultraviolet photoelectron spectroscopic measurements revealed electron affinity and ionization energy of 3.4 ± 0.1 eV and 6.8 ± 0.1 eV for nonpolar GaN film and 3.8 ± 0.1 eV and 7.2 ± 0.1 eV for polar GaN film respectively. Field Emission Scanning Electron Microscopy measurements divulged smooth morphology with pits on polar GaN film. The nonpolar film on the other hand showed pyramidal structures having facets all over the surface.

  4. Analysis of Nitro-aromatic and Nitramine Explosives by Atmospheric Pressure Chemical Ionization / High Performance Liquid Chromatography / Mass Spectrometry / Mass Spectrometry

    International Nuclear Information System (INIS)

    Hicks, B.J.; Han, W.; Robben, J.R.

    2009-01-01

    This procedure is capable of separating and quantifying twenty-nine high explosives and internal surrogates with a single injection. After the initial preparation step, the sample is introduced to the high performance liquid chromatograph for target separation, ionized by atmospheric pressure chemical ionization and the explosives of interest are isolated / quantified by mass spectrometry / mass spectrometry. Concentrations of the target explosives are measured relative to the response of both internal and external standard concentrations. A C-18 reverse phase high performance liquid chromatograph column is used for separation. Ionization is performed using both positive and negative atmospheric pressure chemical ionization resulting in a molecular ion with little fragmentation. These ions are isolated at the first quadrupole of the mass spectrometer, dissociated by collision with argon in the collision cell and the resulting daughter ions are isolated at the second quadrupole. These daughter ions then reach the detector where they are quantified. To date this procedure represents the most thorough high performance liquid chromatography / mass spectrometry / mass spectrometry explosives analysis available in the environmental chemistry market. (authors)

  5. Pressure-induced change in the Raman spectra of ionic liquid [DEME][BF4]-H2O mixtures

    International Nuclear Information System (INIS)

    Imai, Y; Abe, H; Goto, T; Miyashita, T; Yoshimura, Y

    2010-01-01

    We have measured Raman spectral changes of N,N,diethyl-N-methyl-N-(2-methoxyethyl) ammonium tetrafluoroborate, [DEME][BF 4 ]-H 2 O mixtures under high pressure. All the Raman spectra of mixtures of water concentrations below 50.0 mol% H 2 O changed at around 1 GPa at room temperature. The spectrum at high pressure is completely different from that obtained by cooling the sample at a normal pressure.

  6. Ultrapressure liquid chromatography-tandem mass spectrometry assay using atmospheric pressure photoionization (UPLC-APPI-MS/MS) for quantification of 4-methoxydiphenylmethane in pharmacokinetic evaluation.

    Science.gov (United States)

    Farhan, Nashid; Fitzpatrick, Sean; Shim, Yun M; Paige, Mikell; Chow, Diana Shu-Lian

    2016-09-05

    4-Methoxydiphenylmethane (4-MDM), a selective augmenter of Leukotriene A4 Hydrolase (LTA4H), is a new anti-inflammatory compound for potential treatment of chronic obstructive pulmonary disease (COPD). Currently, there is no liquid chromatography tandem mass spectrometric (LC-MS/MS) method for the quantification of 4-MDM. A major barrier for developing the LC-MS/MS method is the inability of electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) to ionize 4-MDM due to its hydrophobicity and lack of any functional group for ionization. With the advent of atmospheric pressure photoionization (APPI) technique, many hydrophobic compounds have been demonstrated to ionize by charge transfer reactions. In this study, a highly sensitive ultrapressure liquid chromatography tandem mass spectrometry assay using atmospheric pressure photoionization (UPLC-APPI-MS/MS) for the quantifications of 4-MDM in rat plasma has been developed and validated. 4-MDM was extracted from the plasma by solid phase extraction (SPE) and separated chromatographically using a reverse phase C8 column. The photoionization (PI) was achieved by introducing anisole as a dopant to promote the reaction of charge transfer. The assay with a linear range of 5 (LLOQ)-400ngmL(-1) met the regulatory requirements for accuracy, precision and stability. The validated assay was employed to quantify the plasma concentrations of 4-MDM after an oral dosing in Sprague Dawley (SD) rats. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Comparison of the Viscous Liquids Spraying by the OIG and the Oil Configurations of an Effervescent Atomizer at Low Inlet Pressures

    Directory of Open Access Journals (Sweden)

    Mlkvik Marek

    2016-07-01

    Full Text Available In this work we studied the influence of the fluid injection configuration (OIG: outside-in-gas, OIL: outside-in-liquid on the internal flows and external sprays parameters. We sprayed the viscous aqueous maltodextrin solutions (μ = 60 mPa·s at a constant inlet pressure of the gas and the gas to the liquid mass flow ratio (GLR within the range 2.5 to 20%. We found that the fluids injection has a crucial influence on the internal flows. The internal flows patterns for the OIG atomizer were the slug flows, the internal flow of the OIL device was annular which led to the significant improvement of the spray quality: Smaller droplets, faster atomization, fewer pulsations.

  8. Comparison of intraocular pressure during the application of a liquid patient interface (FEMTO LDV Z8) for femtosecond laser-assisted cataract surgery using two different vacuum levels.

    Science.gov (United States)

    Ebner, Martina; Mariacher, Siegfried; Januschowski, Kai; Boden, Katrin; Seuthe, Anna-Maria; Szurman, Peter; Boden, Karl Thomas

    2017-08-01

    To evaluate intraocular pressure (IOP) using the application of a novel liquid patient interface for femtosecond laser-assisted cataract surgery with the FEMTO LDV Z8. IOP was evaluated in enucleated porcine eyes prior, during and after the application of the Femto LDV Z8 liquid patient interface (Ziemer Ophthalmic Systems, Switzerland) using intracameral cannulation (n=20), intravitreal cannulation (n=20), rebound tonometry (n=20) and indentation tonometry (n=20). Pressure was assessed prior vacuum, during vacuum (30 s, 1 min, 2 min, 3 min) and after releasing the vacuum (1 min and 2 min). Two groups with different predefined vacuum levels (350 mbar, 420 mbar) were investigated. Mean intracameral pressure (±SD) increased during vacuum application from 20 mm Hg to 52.00 mm Hg (±6.35mm Hg; p=0.005) and 45.18 mmHg (±4.34 mm Hg; p=0.005) for the 420 mbar and the 350 mbar vacuum levels, respectively. Mean intravitreal pressure increased from 20 mm Hg to 25.60 mm Hg (±9.85 mm Hg; p=0.058) and 28.10 mm Hg (±2.54 mm Hg; p=0.059) for the 420 mbar and the 350 mbar vacuum levels, respectively. Pressure values from indentation and rebound tonometry were in between intracameral and intravitreal values. Mean intracameral IOP was 18.1% higher (p=0.019) in the 420 mbar group compared with the 350 mbar group. During vacuum application of the liquid patient interface of the Femto LDV Z8 for femtosecond laser-assisted cataract surgery, IOP values were higher in the anterior chamber compared with the intravitreal pressure measurements. The higher predefined vacuum level (350 mbar vs 420 mbar) resulted in significant higher intracameral IOP. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  9. The physics and chemistry of room-temperature liquid-filled ionization chambers

    International Nuclear Information System (INIS)

    Holroyd, R.A.

    1985-01-01

    The properties of excess electrons in non-polar liquids, such as tetramethylsilane and 2,2,4,4-tetramethylpentane, which are suitable for room-temperature liquid-filled ionization chambers are reviewed. Such properties as mobility, ionization yield, conduction band energy, trapping, and the influence of the electric field are considered. (orig.)

  10. Combined high-pressure liquid chromatography and radioimmunoassay method for the quantitation of Δ9-tetrahydrocannabinol and some of its metabolites in human plasma

    International Nuclear Information System (INIS)

    Williams, P.L.; Moffat, A.C.; King, L.J.

    1978-01-01

    A high-pressure liquid chromatography-radioimmunoassay (HPLC-RIA) method for the measurement of cannabinoid levels in plasma is described. The method is capable of quantifying 0.1 ng of a cannabinoid in 1 ml of plasma. The experimental procedure consists of an initial separation of cannabinoids in a plasma extract by HPLC followed by collection of the HPLC eluate and RIA. A chromatogram consisting of the cross-reacting cannabinoids in plasma may then be constructed. The plasma concentrations of cannabinoids with retention volumes equivalent to those of Δ 9 -terahydrocannabinol, cannabinol and mono-hydroxylated metabolites have been measured by this technique. (Auth.)

  11. Ab initio calculation of the shear viscosity of neon in the liquid and hypercritical state over a wide pressure and temperature range

    Science.gov (United States)

    Eggenberger, Rolf; Gerber, Stefan; Huber, Hanspeter; Searles, Debra; Welker, Marc

    1992-08-01

    The shear viscosity is calculated ab initio for the liquid and hypercritical state, i.e. a previously published potential for Ne 2, obtained from ab initio calculations including electron correlation, is used in classical equilibrium molecular dynamics simulations to obtain the shear viscosity from a Green-Kubo integral. The quality of the results is quite uniform over a large pressure range up to 1000 MPa and a wide temperature range from 26 to 600 K. In most cases the calculated shear viscosity deviates by less than 10% from the experimental value, in general the error being only a few percent.

  12. 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...

  13. Analysis of Poly-β-Hydroxybutyrate in Rhizobium japonicum Bacteroids by Ion-Exclusion High-Pressure Liquid Chromatography and UV Detection †

    Science.gov (United States)

    Karr, Dale B.; Waters, James K.; Emerich, David W.

    1983-01-01

    Ion-exclusion high-pressure liquid chromatography (HPLC) was used to measure poly-β-hydroxybutyrate (PHB) in Rhizobium japonicum bacteroids. The products in the acid digest of PHB-containing material were fractionated by HPLC on Aminex HPX-87H ion-exclusion resin for organic acid analysis. Crotonic acid formed from PHB during acid digestion was detected by its intense absorbance at 210 nm. The Aminex-HPLC method provides a rapid and simple chromatographic technique for routine analysis of organic acids. Results of PHB analysis by Aminex-HPLC were confirmed by gas chromatography and spectrophotometric analysis. PMID:16346443

  14. Quantitation of triacylglycerols in edible oils by off-line comprehensive two-dimensional liquid chromatography-atmospheric pressure chemical ionization mass spectrometry using a single column.

    Science.gov (United States)

    Wei, Fang; Hu, Na; Lv, Xin; Dong, Xu-Yan; Chen, Hong

    2015-07-24

    In this investigation, off-line comprehensive two-dimensional liquid chromatography-atmospheric pressure chemical ionization mass spectrometry using a single column has been applied for the identification and quantification of triacylglycerols in edible oils. A novel mixed-mode phenyl-hexyl chromatographic column was employed in this off-line two-dimensional separation system. The phenyl-hexyl column combined the features of traditional C18 and silver-ion columns, which could provide hydrophobic interactions with triacylglycerols under acetonitrile conditions and can offer π-π interactions with triacylglycerols under methanol conditions. When compared with traditional off-line comprehensive two-dimensional liquid chromatography employing two different chromatographic columns (C18 and silver-ion column) and using elution solvents comprised of two phases (reversed-phase/normal-phase) for triacylglycerols separation, the novel off-line comprehensive two-dimensional liquid chromatography using a single column can be achieved by simply altering the mobile phase between acetonitrile and methanol, which exhibited a much higher selectivity for the separation of triacylglycerols with great efficiency and rapid speed. In addition, an approach based on the use of response factor with atmospheric pressure chemical ionization mass spectrometry has been developed for triacylglycerols quantification. Due to the differences between saturated and unsaturated acyl chains, the use of response factors significantly improves the quantitation of triacylglycerols. This two-dimensional liquid chromatography-mass spectrometry system was successfully applied for the profiling of triacylglycerols in soybean oils, peanut oils and lord oils. A total of 68 triacylglycerols including 40 triacylglycerols in soybean oils, 50 triacylglycerols in peanut oils and 44 triacylglycerols in lord oils have been identified and quantified. The liquid chromatography-mass spectrometry data were analyzed

  15. Sorption Properties of Aerogel in Liquid Nitrogen

    Science.gov (United States)

    Johnson, Wesley L.

    2006-01-01

    Aerogel products are now available as insulation materials of the future. The Cryogenics Test Laboratory at the NASA Kennedy Space Center is developing aerogel-based thermal insulation systems for space launch applications. Aerogel beads (Cabot Nanogel ) and aerogel blankets (Aspen Aerogels Spaceloft ) have outstanding ambient pressure thermal performance that makes them useful for applications where sealing is not possible. Aerogel beads are open-celled silicone dioxide and have tiny pores that run throughout the body of the bead. It has also recently been discovered that aerogel beads can be used as a filtering device for aqueous compounds at room temperature. With their hydrophobic covering, the beads absorb any non-polar substance and they can be chemically altered to absorb hot gases. The combination of the absorption and cryogenic insulating properties of aerogel beads have never been studied together. For future cryogenic insulation applications, it is crucial to know how the beads react while immersed in cryogenic liquids, most notably liquid nitrogen. Aerogel beads in loose-fill situation and aerogel blankets with composite fiber structure have been tested for absorption properties. Depending on the type of aerogel used and the preparation, preliminary results show the material can absorb up to seven times its own weight of liquid nitrogen, corresponding to a volumetric ratio of 0.70 (unit volume nitrogen per unit volume aerogel). These tests allow for an estimate on how much insulation is needed in certain situations. The theory behind the different processes of sorption is necessary for a better understanding of the preparation of the beads before they are used in an insulation system.

  16. A flowing liquid test system for assessing the linearity and time-response of rapid fibre optic oxygen partial pressure sensors.

    Science.gov (United States)

    Chen, R; Hahn, C E W; Farmery, A D

    2012-08-15

    The development of a methodology for testing the time response, linearity and performance characteristics of ultra fast fibre optic oxygen sensors in the liquid phase is presented. Two standard medical paediatric oxygenators are arranged to provide two independent extracorporeal circuits. Flow from either circuit can be diverted over the sensor under test by means of a system of rapid cross-over solenoid valves exposing the sensor to an abrupt change in oxygen partial pressure, P O2. The system is also capable of testing the oxygen sensor responses to changes in temperature, carbon dioxide partial pressure P CO2 and pH in situ. Results are presented for a miniature fibre optic oxygen sensor constructed in-house with a response time ≈ 50 ms and a commercial fibre optic sensor (Ocean Optics Foxy), when tested in flowing saline and stored blood. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Two-step Purification Method for Aging Pigments A2E and Iso-A2E Using Medium Pressure Liquid Chromatography

    International Nuclear Information System (INIS)

    Park, Sang Il; Park, Sang Cheol; Kim, So Ra; Jang, Young Pyo

    2016-01-01

    A newly modified method for the efficient purification of A2E and iso-A2E using reverse phase silica gel resin with medium pressure liquid chromatography (MPLC) was suggested. MPLC is one of the various preparative column chromatography techniques and separation under pressure renders the use of smaller particle size resins possible and increases the diversity of available stationary phases. A simplified two-step purification method was developed for the purification of aging pigments in eye, A2E and iso-A2E. With simple two-step elution of mobile phase in reverse phase MPLC, A2E and iso-A2E were successfully purified with great efficiency compare with previous column chromatography and HPLC method. This method provides more simple, convenient, cost-effective, and less time-consuming procedure for mass purification of aging pigments A2E and iso-A2E

  18. Vapour pressure measurements over liquid UO{sub 2} and (U,Pu)O{sub 2} by laser surface heating up to 5000 K

    Energy Technology Data Exchange (ETDEWEB)

    Babelot, J F; Brumme, G D [Institut fuer Angewandte Physik, TH Darmstadt (Germany); Kinsman, P R; Ohse, R W [Commission of the European Communities, European Institute for Transuranium Elements, EURATOM (Germany)

    1977-07-01

    Nuclear reactor technology requires the vapour pressure of fast breeder reactor fuels up to 6000 K in order to estimate the energy release In hypothetical fast reactor core meltdown accident. Both theoretical and experimental efforts are needed to provide the required data. In principle PVT data can be estimated by appropriate theoretical models, extrapolating measured data, or by purely thermodynamic calculations based on the extrapolation of reliable low temperature thermodynamic data. Direct measurements require the development of new experimental techniques for the extreme temperature range of interest in nuclear technology. The various theoretical approaches are characterized by the application of models which were conceived for simple molecular liquids and by the extrapolation of low temperature vapour pressure data over several thousand degrees, leading to a range In predicted critical point temperatures from 6000 K to almost 10000 K.

  19. Two-step Purification Method for Aging Pigments A2E and Iso-A2E Using Medium Pressure Liquid Chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sang Il; Park, Sang Cheol [Kyunghee Univ., Seoul (Korea, Republic of); Kim, So Ra; Jang, Young Pyo [Seoul National Univ., Seoul (Korea, Republic of)

    2016-09-15

    A newly modified method for the efficient purification of A2E and iso-A2E using reverse phase silica gel resin with medium pressure liquid chromatography (MPLC) was suggested. MPLC is one of the various preparative column chromatography techniques and separation under pressure renders the use of smaller particle size resins possible and increases the diversity of available stationary phases. A simplified two-step purification method was developed for the purification of aging pigments in eye, A2E and iso-A2E. With simple two-step elution of mobile phase in reverse phase MPLC, A2E and iso-A2E were successfully purified with great efficiency compare with previous column chromatography and HPLC method. This method provides more simple, convenient, cost-effective, and less time-consuming procedure for mass purification of aging pigments A2E and iso-A2E.

  20. Study on the effect of distance between the two nozzle holes on interaction of high pressure combustion-gas jets with liquid

    International Nuclear Information System (INIS)

    Xue, Xiaochun; Yu, Yonggang; Zhang, Qi

    2014-01-01

    Highlights: • We design a five-stage cylindrical stepped-wall chamber to study twin combustion-gas jets. • We observe mixing processes of twin combustion-gases and liquid by high speed photographic system. • We discuss the influence of multiple parameters on expansion shape of the Taylor cavities. • The three-dimensional mathematics model is established to simulate the energy release process. • We obtain distribution characteristics of parameters under different nozzle distances. - Abstract: The combustion-gas generator and cylindrical stepped-wall observation chambers with five stages are designed to study the expansion characteristic of twin combustion-gas jets in liquid working medium under high temperature and high pressure. The expansion processes of Taylor cavities formed by combustion-gas jets and the mixing characteristics of gas–liquid are studied by means of high-speed digital camera system. The effects of the distance between the two nozzle holes, injection pressure and nozzle diameter on jet expansion processes are discussed. The experimental results indicate that, the velocity differences exist on the gas–liquid interface during expansion processes of twin combustion-gas jets, and the effect of Taylor–Helmholtz instability is intense, so interfaces between gas and liquid show turbulent folds and randomness. The strong turbulent mixing of gas and liquid leads to release of combustion-gas energy with the temperature decreasing. Moreover, the mixing effectiveness is obviously enhanced on the corners of each step of the cylindrical stepped-wall structure, forming radial expansion phenomenon. The reasonable matching of multi-parameter can restrain the jet instability and make the combustion-gas energy orderly release. Based on the experiments, the three-dimensional unsteady mathematical model of interaction of twin combustion-gas jets and liquid working medium is established to obtain the density, pressure, velocity and temperature