WorldWideScience

Sample records for level liquid phase

  1. Phase behaviour of macromolecular liquid crystalline materials. Computational studies at the molecular level

    International Nuclear Information System (INIS)

    Stimson, Lorna M.

    2003-01-01

    Molecular simulations provide an increasingly useful insight into the static and dynamic characteristics of materials. In this thesis molecular simulations of macro-molecular liquid crystalline materials are reported. The first liquid crystalline material that has been investigated is a side chain liquid crystal polymer (SCLCP). In this study semi-atomistic molecular dynamics simulations have been conducted at a range of temperatures and an aligning potential has been applied to mimic the effect of a magnetic field. In cooling the SCLCP from an isotropic melt, microphase separation was observed yielding a domain structure. The application of a magnetic field to this structure aligns the domains producing a stable smectic mesophase. This is the first study in which mesophases have been observed using an off-lattice model of a SCLCP. The second material that has been investigated is a dendrimer with terminal mesogenic functionalization. Here, a multi-scale approach has been taken with Monte Carlo studies of a single dendrimer molecule in the gas phase at the atomistic level, semi-atomistic molecular dynamics of a single molecule in liquid crystalline solvents and a coarse-grained molecular dynamics study of the dendrimer in the bulk. The coarse-grained model has been developed and parameterized using the results of the atomistic and semi-atomistic work. The single molecule studies showed that the liquid crystalline dendrimer was able to change its structure by conformational changes in the flexible chains that link the mesogenic groups to the core. Structural change was seen under the application of a mean field ordering potential in the gas phase, and in the presence of liquid crystalline solvents. No liquid crystalline phases were observed for the bulk phase studies of the coarse-grained model. However, when the length of the mesogenic units was increased there was some evidence for microphase separation in these systems. (author)

  2. Liquid level detector

    International Nuclear Information System (INIS)

    Dean, A.P.; Pendleton, J.R.

    1982-01-01

    A device is described for locating the level of the liquid metal in a sodium cooled nuclear reactor by using a movable probe equipped to signal a phase change with null on arrival at the interface between two conductively differing media. (U.K.)

  3. Modeling of liquid phases

    CERN Document Server

    Soustelle, Michel

    2015-01-01

    This book is part of a set of books which offers advanced students successive characterization tool phases, the study of all types of phase (liquid, gas and solid, pure or multi-component), process engineering, chemical and electrochemical equilibria, and the properties of surfaces and phases of small sizes. Macroscopic and microscopic models are in turn covered with a constant correlation between the two scales. Particular attention has been given to the rigor of mathematical developments. This second volume in the set is devoted to the study of liquid phases.

  4. Numerical simulation of interface movement in gas-liquid two-phase flows with Level Set method

    International Nuclear Information System (INIS)

    Li Huixiong; Chinese Academy of Sciences, Beijing; Deng Sheng; Chen Tingkuan; Zhao Jianfu; Wang Fei

    2005-01-01

    Numerical simulation of gas-liquid two-phase flow and heat transfer has been an attractive work for a quite long time, but still remains as a knotty difficulty due to the inherent complexities of the gas-liquid two-phase flow resulted from the existence of moving interfaces with topology changes. This paper reports the effort and the latest advances that have been made by the authors, with special emphasis on the methods for computing solutions to the advection equation of the Level set function, which is utilized to capture the moving interfaces in gas-liquid two-phase flows. Three different schemes, i.e. the simple finite difference scheme, the Superbee-TVD scheme and the 5-order WENO scheme in combination with the Runge-Kutta method are respectively applied to solve the advection equation of the Level Set. A numerical procedure based on the well-verified SIMPLER method is employed to numerically calculate the momentum equations of the two-phase flow. The above-mentioned three schemes are employed to simulate the movement of four typical interfaces under 5 typical flowing conditions. Analysis of the numerical results shows that the 5-order WENO scheme and the Superbee-TVD scheme are much better than the simple finite difference scheme, and the 5-order WENO scheme is the best to compute solutions to the advection equation of the Level Set. The 5-order WENO scheme will be employed as the main scheme to get solutions to the advection equations of the Level Set when gas-liquid two-phase flows are numerically studied in the future. (authors)

  5. Two-phase mixture level swell and liquid entrainment/off-take in a vessel during rapid depressurization

    International Nuclear Information System (INIS)

    Kim, Chang Hyun

    2004-02-01

    An experimental study has been performed to analyze the two-phase mixture level swell and the liquid entrainment/off-take through the break in a vessel, which are important phenomena to determine the bleed capacity of the Safety Depressurization System (SDS) of Korea Advanced Power Reactor 1400 (APR1400). Three separate experiments are performed in this study: (a) the depressurization and two-phase mixture level swell experiment: (b) the two-phase mixture level measurement experiment: (c) the liquid entrainment and off-take experiment. A series of experiments has been performed using a scaled pressurized vessel in various depressurization conditions to analyze the two-phase mixture level swell and the liquid entrainment/off-take phenomena from the two-phase mixture surface in the first experiment. The test parameters are the initial pressure (10 - 38.75bars), the initial water level (43.7% - 80.0% of full height), the orifice inner diameter (10mm, 17.5mm, and 20mm). The liquid off-take takes place in certain experimental conditions. The measured parameters in the present experiments are axial void fraction distributions, pressures, temperatures in the test vessel, and the mixture density and mass flowrate through the discharge pipe. An assessment of RELAP5/MOD3 code with the present experimental data has been performed. With appropriate nodalization and time step, RELAP5/MOD3 showed reasonable agreement with the present experimental data for the gradual depressurization without liquid off-take. In the case that the off-take takes place, however, RELAP5/MOD3 under-predicts the amount of liquid entrainment/off-take during depressurization. In the second experiment, an assessment of an ultrasonic sensor and a two-wire type capacitance probe for the two-phase mixture level measurement has been performed under the same experimental conditions to adopt an appropriate measurement method for the two-phase mixture level swell and to investigate pool void fraction by the

  6. PEP liquid level system

    International Nuclear Information System (INIS)

    Lauritzen, T.; Sah, R.C.

    1981-03-01

    A liquid level system has been installed in the accelerator housing of the PEP storage ring. This instrument spans the entire 2.2 km circumference of the PEP project, and over one hundred readouts provide reference elevations which are used for the accurate alignment of accelerator components. The liquid level has proven to be extremely precise (+-0.10 mm) and quick to use, and it has contributed to the accurate alignment of PEP before beam turn-on. Since the liquid level readouts are rigidly attached to the accelerator housing, the liquid level has been a convenient means to monitor the settling of the accelerator housing

  7. Liquid level controller

    International Nuclear Information System (INIS)

    Mangus, J.D.; Redding, A.H.

    1975-01-01

    A system for maintaining two distinct sodium levels within the shell of a heat exchanger having a plurality of J-shaped modular tube bundles each enclosed in a separate shell which extends from a common base portion. A lower liquid level is maintained in the base portion and an upper liquid level is maintained in the shell enwrapping the long stem of the J-shaped tube bundles by utilizing standpipes with a notch at the lower end which decreases in open area the distance from the end of the stand pipe increases and a supply of inert gas fed at a constant rate to produce liquid levels, which will remain generally constant as the flow of liquid through the vessel varies

  8. A variational approach to multi-phase motion of gas, liquid and solid based on the level set method

    Science.gov (United States)

    Yokoi, Kensuke

    2009-07-01

    We propose a simple and robust numerical algorithm to deal with multi-phase motion of gas, liquid and solid based on the level set method [S. Osher, J.A. Sethian, Front propagating with curvature-dependent speed: Algorithms based on Hamilton-Jacobi formulation, J. Comput. Phys. 79 (1988) 12; M. Sussman, P. Smereka, S. Osher, A level set approach for capturing solution to incompressible two-phase flow, J. Comput. Phys. 114 (1994) 146; J.A. Sethian, Level Set Methods and Fast Marching Methods, Cambridge University Press, 1999; S. Osher, R. Fedkiw, Level Set Methods and Dynamics Implicit Surface, Applied Mathematical Sciences, vol. 153, Springer, 2003]. In Eulerian framework, to simulate interaction between a moving solid object and an interfacial flow, we need to define at least two functions (level set functions) to distinguish three materials. In such simulations, in general two functions overlap and/or disagree due to numerical errors such as numerical diffusion. In this paper, we resolved the problem using the idea of the active contour model [M. Kass, A. Witkin, D. Terzopoulos, Snakes: active contour models, International Journal of Computer Vision 1 (1988) 321; V. Caselles, R. Kimmel, G. Sapiro, Geodesic active contours, International Journal of Computer Vision 22 (1997) 61; G. Sapiro, Geometric Partial Differential Equations and Image Analysis, Cambridge University Press, 2001; R. Kimmel, Numerical Geometry of Images: Theory, Algorithms, and Applications, Springer-Verlag, 2003] introduced in the field of image processing.

  9. Liquid metal level measurement

    International Nuclear Information System (INIS)

    Hale, J.C.; Leyland, K.S.

    1982-01-01

    A liquid metal level indicator is described which can be used to measure, in a stainless steel tank, the level of a nuclear reactor coolant such as sodium. The instrument, which is based on the eddy current induction effect, gives readings over substantially the full depth of the tank and indicates the sense of change of level. (U.K.)

  10. Liquid Level Sensing System

    Science.gov (United States)

    Korman, Valentin (Inventor); Wiley, John T. (Inventor); Duffell, Amanda G. (Inventor)

    2014-01-01

    A liquid level sensing system includes waveguides disposed in a liquid and distributed along a path with a gap between adjacent waveguides. A source introduces electromagnetic energy into the waveguides at a first end of the path. A portion of the electromagnetic energy exits the waveguides at a second end of the path. A detector measures the portion of the electromagnetic energy exiting the second end of the path.

  11. Crystalline liquids: the blue phases

    Science.gov (United States)

    Wright, David C.; Mermin, N. David

    1989-04-01

    The blue phases of cholesteric liquid crystals are liquids that exhibit orientational order characterized by crystallographic space-group symmetries. We present here a pedagogical introduction to the current understanding of the equilibrium structure of these phases accompanied by a general overview of major experimental results. Using the Ginzburg-Landau free energy appropriate to the system, we first discuss in detail the character and stability of the usual helical phase of cholesterics, showing that for certain parameter ranges the helical phase is unstable to the appearance of one or more blue phases. The two principal models for the blue phases are two limiting cases of the Ginzburg-Landau theory. We explore each limit and conclude with some general considerations of defects in both models and an exact minimization of the free energy in a curved three-dimensional space.

  12. Liquid-liquid phase transition in Stillinger-Weber silicon

    International Nuclear Information System (INIS)

    Beaucage, Philippe; Mousseau, Normand

    2005-01-01

    It was recently demonstrated that Stillinger-Weber silicon undergoes a liquid-liquid first-order phase transition deep into the supercooled region (Sastry and Angell 2003 Nat. Mater. 2 739). Here we study the effects of perturbations on this phase transition. We show that the order of the liquid-liquid transition changes with negative pressure. We also find that the liquid-liquid transition disappears when the three-body term of the potential is strengthened by as little as 5%. This implies that the details of the potential could affect strongly the nature and even the existence of the liquid-liquid phase

  13. Liquid phase chromatography on microchips

    DEFF Research Database (Denmark)

    Kutter, Jörg Peter

    2012-01-01

    explosive development of, in particular, chromatographic separation systems on microchips, has, however, slowed down in recent years. This review takes a closer, critical look at how liquid phase chromatography has been implemented in miniaturized formats over the past several years, what is important...

  14. The Development and Test of a Sensor for Measurement of the Working Level of Gas-Liquid Two-Phase Flow in a Coalbed Methane Wellbore Annulus.

    Science.gov (United States)

    Wu, Chuan; Ding, Huafeng; Han, Lei

    2018-02-14

    Coalbed methane (CBM) is one kind of clean-burning gas and has been valued as a new form of energy that will be used widely in the near future. When producing CBM, the working level within a CBM wellbore annulus needs to be monitored to dynamically adjust the gas drainage and extraction processes. However, the existing method of measuring the working level does not meet the needs of accurate adjustment, so we designed a new sensor for this purpose. The principle of our sensor is a liquid pressure formula, i.e., the sensor monitors the two-phase flow patterns and obtains the mean density of the two-phase flow according to the pattern recognition result in the first step, and then combines the pressure data of the working level to calculate the working level using the liquid pressure formula. The sensor was tested in both the lab and on site, and the tests showed that the sensor's error was ±8% and that the sensor could function well in practical conditions and remain stable in the long term.

  15. The Development and Test of a Sensor for Measurement of the Working Level of Gas–Liquid Two-Phase Flow in a Coalbed Methane Wellbore Annulus

    Directory of Open Access Journals (Sweden)

    Chuan Wu

    2018-02-01

    Full Text Available Coalbed methane (CBM is one kind of clean-burning gas and has been valued as a new form of energy that will be used widely in the near future. When producing CBM, the working level within a CBM wellbore annulus needs to be monitored to dynamically adjust the gas drainage and extraction processes. However, the existing method of measuring the working level does not meet the needs of accurate adjustment, so we designed a new sensor for this purpose. The principle of our sensor is a liquid pressure formula, i.e., the sensor monitors the two-phase flow patterns and obtains the mean density of the two-phase flow according to the pattern recognition result in the first step, and then combines the pressure data of the working level to calculate the working level using the liquid pressure formula. The sensor was tested in both the lab and on site, and the tests showed that the sensor’s error was ±8% and that the sensor could function well in practical conditions and remain stable in the long term.

  16. The Development and Test of a Sensor for Measurement of the Working Level of Gas–Liquid Two-Phase Flow in a Coalbed Methane Wellbore Annulus

    Science.gov (United States)

    Wu, Chuan; Ding, Huafeng; Han, Lei

    2018-01-01

    Coalbed methane (CBM) is one kind of clean-burning gas and has been valued as a new form of energy that will be used widely in the near future. When producing CBM, the working level within a CBM wellbore annulus needs to be monitored to dynamically adjust the gas drainage and extraction processes. However, the existing method of measuring the working level does not meet the needs of accurate adjustment, so we designed a new sensor for this purpose. The principle of our sensor is a liquid pressure formula, i.e., the sensor monitors the two-phase flow patterns and obtains the mean density of the two-phase flow according to the pattern recognition result in the first step, and then combines the pressure data of the working level to calculate the working level using the liquid pressure formula. The sensor was tested in both the lab and on site, and the tests showed that the sensor’s error was ±8% and that the sensor could function well in practical conditions and remain stable in the long term. PMID:29443871

  17. Crystalline phase, microstructure, and aqueous stability of zirconolite-barium borosilicate glass-ceramics for immobilization of simulated sulfate bearing high-level liquid waste

    Science.gov (United States)

    Wu, Lang; Xiao, Jizong; Wang, Xin; Teng, Yuancheng; Li, Yuxiang; Liao, Qilong

    2018-01-01

    The crystalline phase, microstructure, and aqueous stability of zirconolite-barium borosilicate glass-ceramics with different content (0-30 wt %) of simulated sulfate bearing high-level liquid waste (HLLW) were evaluated. The sulfate phase segregation in vitrification process was also investigated. The results show that the glass-ceramics with 0-20 wt% of HLLW possess mainly zirconolite phase along with a small amount baddeleyite phase. The amount of perovskite crystals increases while the amount of zirconolite crystals decreases when the HLLW content increases from 20 to 30 wt%. For the samples with 20-30 wt% HLLW, yellow phase was observed during the vitrification process and it disappeared after melting at 1150 °C for 2 h. The viscosity of the sample with 16 wt% HLLW (HLLW-16) is about 27 dPa·s at 1150 °C. The addition of a certain amount (≤20 wt %) of HLLW has no significant change on the aqueous stability of glass-ceramic waste forms. After 28 days, the 90 °C PCT-type normalized leaching rates of Na, B, Si, and La of the sample HLLW-16 are 7.23 × 10-3, 1.57 × 10-3, 8.06 × 10-4, and 1.23 × 10-4 g·m-2·d-1, respectively.

  18. Molecular-level characterization of crude oil compounds combining reversed-phase high-performance liquid chromatography with off-line high-resolution mass spectrometry

    Science.gov (United States)

    Sim, Arum; Cho, Yunju; Kim, Daae; Witt, Matthias; Birdwell, Justin E.; Kim, Byung Ju; Kim, Sunghwan

    2014-01-01

    A reversed-phase separation technique was developed in a previous study (Loegel et al., 2012) and successfully applied to the de-asphalted fraction of crude oil. However, to the best of our knowledge, the molecular-level characterization of oil fractions obtained by reversed-phase high-performance liquid chromatography (HPLC) coupled with high-resolution mass spectrometry (MS) has not yet been reported. A detailed characterization of the oil fractions prepared by reversed-phase HPLC was performed in this study. HPLC fractionation was carried out on conventional crude oil and an oil shale pyrolysate. The analyses of the fractions showed that the carbon number of alkyl chains and the double bond equivalent (DBE) value were the major factors determining elution order. The compounds with larger DBE (presumably more condensed aromatic structures) and smaller carbon number (presumably compounds with short side chains) were eluted earlier but those compounds with lower DBE values (presumably less aromatic structures) and higher carbon number (presumably compounds with longer alkyl chains) eluted later in the chromatograms. This separation behavior is in good agreement with that expected from the principles of reversed-phase separation. The data presented in this study show that reversed-phase chromatography is effective in separating crude oil compounds and can be combined with ultrahigh-resolution MS data to better understand natural oils and oil shale pyrolysates.

  19. Liquid phase sintered superconducting cermet

    International Nuclear Information System (INIS)

    Ray, S.P.

    1990-01-01

    This patent describes a method of making a superconducting cermet having superconducting properties with improved bulk density, low porosity and in situ stabilization. It comprises: forming a structure of a superconducting ceramic material having the formula RM 2 Cu 3 O (6.5 + x) wherein R is one or more rare earth elements capable of reacting to form a superconducting ceramic, M is one or more alkaline earth metal elements selected from barium and strontium capable of reacting to form a superconducting ceramic, x is greater than 0 and less than 0.5; and a precious metal compound in solid form selected from the class consisting of oxides, sulfides and halides of silver; and liquid phase sintering the mixture at a temperature wherein the precious metal of the precious metal compound is molten and below the melting point of the ceramic material. The liquid phase sintering is carried out for a time less than 36 hours but sufficient to improve the bulk density of the cermet

  20. Test Plan: Phase 1 demonstration of 3-phase electric arc melting furnace technology for vitrifying high-sodium content low-level radioactive liquid wastes

    Energy Technology Data Exchange (ETDEWEB)

    Eaton, W.C. [ed.

    1995-05-31

    This document provides a test plan for the conduct of electric arc vitrification testing by a vendor in support of the Hanford Tank Waste Remediation System (TWRS) Low-Level Waste (LLW) Vitrification Program. The vendor providing this test plan and conducting the work detailed within it [one of seven selected for glass melter testing under Purchase Order MMI-SVV-384216] is the US Bureau of Mines, Department of the Interior, Albany Research Center, Albany, Oregon. This test plan is for Phase I activities described in the above Purchase Order. Test conduct includes feed preparation activities and melting of glass with Hanford LLW Double-Shell Slurry Feed waste simulant in a 3-phase electric arc (carbon electrode) furnace.

  1. Test Plan: Phase 1 demonstration of 3-phase electric arc melting furnace technology for vitrifying high-sodium content low-level radioactive liquid wastes

    International Nuclear Information System (INIS)

    Eaton, W.C.

    1995-01-01

    This document provides a test plan for the conduct of electric arc vitrification testing by a vendor in support of the Hanford Tank Waste Remediation System (TWRS) Low-Level Waste (LLW) Vitrification Program. The vendor providing this test plan and conducting the work detailed within it [one of seven selected for glass melter testing under Purchase Order MMI-SVV-384216] is the US Bureau of Mines, Department of the Interior, Albany Research Center, Albany, Oregon. This test plan is for Phase I activities described in the above Purchase Order. Test conduct includes feed preparation activities and melting of glass with Hanford LLW Double-Shell Slurry Feed waste simulant in a 3-phase electric arc (carbon electrode) furnace

  2. Measurement of underground contamination of non-aqueous phase liquids (NAPLs) on the basis of the radon concentration in ground level air

    International Nuclear Information System (INIS)

    Schubert, M.

    2001-01-01

    It was investigated whether measurements of radon concentrations in ground level air are a suitable method of detecting sub-surface soil contamination with non-aqueous phase liquids (NAPLs). The working postulation was that, due to the very high solubility of radon in NAPLs, and the resulting accumulation of radon in NAPLs, radon exhalation to the ground level air in the proximity of such NAPL contamination should be locally reduced, thus indicating contamination of sub-surface soils with NAPLs. The research work reported was to verify the working theory by way of experiments, and to finally develop a reliable detection method for NAPL contaminations. The investigations comprised theoretical studies, laboratory experiments, experiments in defined soil columns, and extensive field studies [de

  3. Experimental (solid + liquid) or (liquid + liquid) phase equilibria of (amine + nitrile) binary mixtures

    International Nuclear Information System (INIS)

    Domanska, Urszula; Marciniak, Malgorzata

    2007-01-01

    (Solid + liquid) phase diagrams have been determined for (hexylamine, or octylamine, or 1,3-diaminopropane + acetonitrile) mixtures. Simple eutectic systems have been observed in these mixtures. (Liquid + liquid) phase diagrams have been determined for (octylamine, or decylamine + propanenitrile, or + butanenitrile) mixtures. Mixtures with propanenitrile and butanenitrile show immiscibility in the liquid phase with an upper critical solution temperature, UCST. (Solid + liquid) phase diagrams have been correlated using NRTL, NRTL 1, Wilson and UNIQUAC equations. (Liquid + liquid) phase diagrams have been correlated using NRTL equation

  4. Recent development of ionic liquid stationary phases for liquid chromatography.

    Science.gov (United States)

    Shi, Xianzhe; Qiao, Lizhen; Xu, Guowang

    2015-11-13

    Based on their particular physicochemical characteristics, ionic liquids have been widely applied in many fields of analytical chemistry. Many types of ionic liquids were immobilized on a support like silica or monolith as stationary phases for liquid chromatography. Moreover, different approaches were developed to bond covalently ionic liquids onto the supporting materials. The obtained ionic liquid stationary phases show multi-mode mechanism including hydrophobic, hydrophilic, hydrogen bond, anion exchange, π-π, and dipole-dipole interactions. Therefore, they could be used in different chromatographic modes including ion-exchange, RPLC, NPLC and HILIC to separate various classes of compounds. This review mainly summarizes the immobilized patterns and types of ionic liquid stationary phases, their retention mechanisms and applications in the recent five years. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Supported ionic liquid-phase (SILP) catalysis

    DEFF Research Database (Denmark)

    Riisager, Anders; Fehrmann, Rasmus; Wasserscheid, P.

    2005-01-01

    The concept of supported ionic liquid-phase (SILP) catalysis has been demonstrated for gas- and liquid-phase continuous fixed-bed reactions using rhodium phosphine catalyzed hydroformylation of propene and 1-octene as examples. The nature of the support had important influence on both the catalytic...

  6. Supported Ionic Liquid Phase (SILP) catalysis

    DEFF Research Database (Denmark)

    Riisager, Anders; Fehrmann, Rasmus; Haumann, Marco

    2006-01-01

    Applications of ionic liquids to replace conventional solvents in homogeneous transition-metal catalysis have increased significantly during the last decade. Biphasic ionic liquid/organic liquid systems offer advantages with regard to product separation, catalyst stability, and recycling...... but utilise in the case of fast chemical reactions only a small amount of expensive ionic liquid and catalyst. The novel Supported Ionic Liquid Phase (SILP) catalysis concept overcomes these drawbacks and allows the use of fixed-bed reactors for continuous reactions. In this Microreview the SILP catalysis...

  7. Evaluating the Liquid Liquid Phase Transition Hypothesis of Supercoooled Water

    Science.gov (United States)

    Limmer, David; Chandler, David

    2011-03-01

    To explain the anomalous behavior of supercooled water it has been conjectured that buried within an experimentally inaccessible region of liquid water's phase diagram there exists a second critical point, which is the terminus of a first order transition line between two distinct liquid phases. The so-called liquid-liquid phase transition (LLPT) has since generated much study, though to date there is no consensus on its existence. In this talk, we will discuss our efforts to systematically study the metastable phase diagram of supercooled water through computer simulation. By employing importance-sampling techniques, we have calculated free energies as a function of the density and long-range order to determine unambiguously if two distinct liquid phases exist. We will argue that, contrary to the LLPT hypothesis, the observed phenomenology can be understood as a consequence of the limit of stability of the liquid far away from coexistence. Our results suggest that homogeneous nucleation is the cause of the increased fluctuations present upon supercooling. Further we will show how this understanding can be extended to explain experimental observations of hysteresis in confined supercooled water systems.

  8. Liquid level control system for vapour generator

    International Nuclear Information System (INIS)

    Singh, G.

    1984-01-01

    A system for regulating the liquid level in a vapor generator, in which the incoming flow of feed liquid is regulated in response to the difference between the measured liquid level and a reference level, the difference between the exiting vapor mass flow rate and the incoming liquid mass flow rate, and a function of the measured incoming liquid temperature. The temperature function produces a gain value, which increases in response to decreasing incoming liquid temperature. The purpose of the temperature function is to stabilize the level control under transient conditions (e.g. sudden lose of load). (author)

  9. Comment on "Spontaneous liquid-liquid phase separation of water"

    Science.gov (United States)

    Limmer, David T.; Chandler, David

    2015-01-01

    Yagasaki et al. [Phys. Rev. E 89, 020301 (2014), 10.1103/PhysRevE.89.020301] present results from a molecular dynamics trajectory illustrating coarsening of ice, which they interpret as evidence of transient coexistence between two distinct supercooled phases of liquid water. We point out that neither two distinct liquids nor criticality are demonstrated in this simulation study. Instead, the illustrated trajectory is consistent with coarsening behaviors analyzed and predicted in earlier work by others.

  10. Comment on "Spontaneous liquid-liquid phase separation of water".

    Science.gov (United States)

    Limmer, David T; Chandler, David

    2015-01-01

    Yagasaki et al. [Phys. Rev. E 89, 020301 (2014)] present results from a molecular dynamics trajectory illustrating coarsening of ice, which they interpret as evidence of transient coexistence between two distinct supercooled phases of liquid water. We point out that neither two distinct liquids nor criticality are demonstrated in this simulation study. Instead, the illustrated trajectory is consistent with coarsening behaviors analyzed and predicted in earlier work by others.

  11. Liquid Crystals - The 'Fourth' Phase of Matter

    Indian Academy of Sciences (India)

    possibilities of novel technological applications. Liquid crystalline materials ... advanced instrumentation, including laptops and futuristic flat panel displays. .... The twist grain-boundary phase is formed when the layers of a smectic A phase are .... the optic axis) is uniformly oriented parallel to the glass plate. (see Figure IIa).

  12. Liquid phase and supercooled liquid phase welding of bulk metallic glasses

    International Nuclear Information System (INIS)

    Kawamura, Y.

    2004-01-01

    Recent progress on welding in bulk metallic glasses (BMGs) has been reviewed. BMGs have been successfully welded to BMGs or crystalline metals by liquid phase welding using explosion, pulse-current and electron-beam methods, and by supercooled liquid phase welding using friction method. Successful welding of the liquid phase methods was due to the high glass-forming ability of the BMGs and the high concentration of welding energy in these methods. In contrast, the supercooled liquid phase welding was successful due to the thermally stable supercooled liquid state of the BMGs and the superplasticity and viscous flow of the supercooled liquid. The successful welding of BMGs to BMGs and crystalline materials is promising for the future development of BMGs as engineering materials

  13. The nuclear liquid gas phase transition and phase coexistence

    International Nuclear Information System (INIS)

    Chomaz, Ph.

    2001-01-01

    In this talk we will review the different signals of liquid gas phase transition in nuclei. From the theoretical side we will first discuss the foundations of the concept of equilibrium, phase transition and critical behaviors in infinite and finite systems. From the experimental point of view we will first recall the evidences for some strong modification of the behavior of hot nuclei. Then we will review quantitative detailed analysis aiming to evidence phase transition, to define its order and phase diagram. Finally, we will present a critical discussion of the present status of phase transitions in nuclei and we will draw some lines for future development of this field. (author)

  14. The nuclear liquid gas phase transition and phase coexistence

    Energy Technology Data Exchange (ETDEWEB)

    Chomaz, Ph

    2001-07-01

    In this talk we will review the different signals of liquid gas phase transition in nuclei. From the theoretical side we will first discuss the foundations of the concept of equilibrium, phase transition and critical behaviors in infinite and finite systems. From the experimental point of view we will first recall the evidences for some strong modification of the behavior of hot nuclei. Then we will review quantitative detailed analysis aiming to evidence phase transition, to define its order and phase diagram. Finally, we will present a critical discussion of the present status of phase transitions in nuclei and we will draw some lines for future development of this field. (author)

  15. Lyotropic Liquid Crystal Phases from Anisotropic Nanomaterials

    Directory of Open Access Journals (Sweden)

    Ingo Dierking

    2017-10-01

    Full Text Available Liquid crystals are an integral part of a mature display technology, also establishing themselves in other applications, such as spatial light modulators, telecommunication technology, photonics, or sensors, just to name a few of the non-display applications. In recent years, there has been an increasing trend to add various nanomaterials to liquid crystals, which is motivated by several aspects of materials development. (i addition of nanomaterials can change and thus tune the properties of the liquid crystal; (ii novel functionalities can be added to the liquid crystal; and (iii the self-organization of the liquid crystalline state can be exploited to template ordered structures or to transfer order onto dispersed nanomaterials. Much of the research effort has been concentrated on thermotropic systems, which change order as a function of temperature. Here we review the other side of the medal, the formation and properties of ordered, anisotropic fluid phases, liquid crystals, by addition of shape-anisotropic nanomaterials to isotropic liquids. Several classes of materials will be discussed, inorganic and mineral liquid crystals, viruses, nanotubes and nanorods, as well as graphene oxide.

  16. The Development and Test of a Sensor for Measurement of the Working Level of Gas–Liquid Two-Phase Flow in a Coalbed Methane Wellbore Annulus

    OpenAIRE

    Chuan Wu; Huafeng Ding; Lei Han

    2018-01-01

    Coalbed methane (CBM) is one kind of clean-burning gas and has been valued as a new form of energy that will be used widely in the near future. When producing CBM, the working level within a CBM wellbore annulus needs to be monitored to dynamically adjust the gas drainage and extraction processes. However, the existing method of measuring the working level does not meet the needs of accurate adjustment, so we designed a new sensor for this purpose. The principle of our sensor is a liquid pres...

  17. Fluorescent optical liquid-level sensor

    International Nuclear Information System (INIS)

    Weiss, Jonathan D.

    2000-01-01

    An optical method of detecting a liquid level is presented that uses fluorescence radiation generated in an impurity-doped glass or plastic slab. In operation, the slab is inserted into the liquid and pump light is coupled into it so that the light is guided by the slab-air interface above the liquid and escapes into the liquid just below its surface. Since the fluorescence is generated only in that section of the slab above the liquid, the fluorescence power will monotonically decrease with increasing liquid level. Thus, a relationship can be established between any signal proportional to it and the liquid level. Because optical fibers link the pump source and the detector of fluorescence radiation to the sensor, no electrical connections are needed in or near the liquid. Their absence vastly decreases the hazard associated with placing a liquid-level sensor in a potentially explosive environment. A laboratory prototype, consisting of a methyl styrene slab doped with an organic dye, has been built and successfully tested in water. Its response to liquid level when pumped by a tunable argon-ion laser at 476, 488, and 496 nm, and by a blue LED, is presented and shown to be consistent with theory. The fluorescence spectra, optical efficiency, temperature, and other effects are also presented and discussed. (c) 2000 Society of Photo-Optical Instrumentation Engineers

  18. Transport of Liquid Phase Organic Solutes in Liquid Crystalline Membranes

    OpenAIRE

    Han, Sangil

    2010-01-01

    Porous cellulose nitrate membranes were impregnated with 8CB and PCH5 LCs (liquid crystals) and separations of solutes dissolved in aqueous phases were performed while monitoring solute concentration via UV-VIS spectrometry. The diffusing organic solutes, which consist of one aromatic ring and various functional groups, were selected to exclude molecular size effects on the diffusion and sorption. We studied the effects on solute transport of solute intra-molecular hydrogen bonding and so...

  19. Liquid level measurement in high level nuclear waste slurries

    International Nuclear Information System (INIS)

    Weeks, G.E.; Heckendorn, F.M.; Postles, R.L.

    1990-01-01

    Accurate liquid level measurement has been a difficult problem to solve for the Defense Waste Processing Facility (DWPF). The nuclear waste sludge tends to plug or degrade most commercially available liquid-level measurement sensors. A liquid-level measurement system that meets demanding accuracy requirements for the DWPF has been developed. The system uses a pneumatic 1:1 pressure repeater as a sensor and a computerized error correction system. 2 figs

  20. Ionic liquid stationary phases for gas chromatography.

    Science.gov (United States)

    Poole, Colin F; Poole, Salwa K

    2011-04-01

    This article provides a summary of the development of ionic liquids as stationary phases for gas chromatography beginning with early work on packed columns that established details of the retention mechanism and established working methods to characterize selectivity differences compared with molecular stationary phases through the modern development of multi-centered cation and cross-linked ionic liquids for high-temperature applications in capillary gas chromatography. Since there are many reviews on ionic liquids dealing with all aspects of their chemical and physical properties, the emphasis in this article is placed on the role of gas chromatography played in the design of ionic liquids of low melting point, high thermal stability, high viscosity, and variable selectivity for separations. Ionic liquids provide unprecedented opportunities for extending the selectivity range and temperature-operating range of columns for gas chromatography, an area of separation science that has otherwise been almost stagnant for over a decade. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Analysis of trace levels of sulfonamide and tetracycline antimicrobials in groundwater and surface water using solid-phase extraction and liquid chromatography/mass spectrometry

    Science.gov (United States)

    Lindsey, M.E.; Meyer, M.; Thurman, E.M.

    2001-01-01

    A method has been developed for the trace analysis of two classes of antimicrobials consisting of six sulfonamides (SAs) and five tetracyclines (TCs), which commonly are used for veterinary purposes and agricultural feed additives and are suspected to leach into ground and surface water. The method used solid-phase extraction and liquid chromatography/mass spectrometry (LC/MS) with positive ion electrospray. The unique combination of a metal chelation agent (Na2EDTA) with a macroporous copolymer resulted in quantitative recoveries by solid-phase extraction (mean recovery, 98 ?? 12%) at submicrogram-per-liter concentrations. An ammonium formate/formic acid buffer with a methanol/water gradient was used to separate the antimicrobials and to optimize the signal intensity. Mass spectral fragmentation and ionization characteristics were determined for each class of compounds for unequivocal identification. For all SAs, a characteristic m/z 156 ion representing the sulfanilyl fragment was identified. TCs exhibited neutral losses of 17 amu resulting from the loss of ammonia and 35 amu from the subsequent loss of water. Unusual matrix effects were seen only for TCs in this first survey of groundwater and surface water samples from sites around the United States, requiring that TCs be quantitated using the method of standard additions.

  2. (Liquid + liquid) phase behavior for systems containing (aromatic + TBA + methylcyclohexane)

    International Nuclear Information System (INIS)

    Ghanadzadeh, H.; Ghanadzadeh, A.

    2004-01-01

    The determination region of solubility of TBA (tert-butanol) with representative compounds of the gasoline was investigated experimentally at temperature of 298.2 K. Type 1 (liquid + liquid) phase diagrams were obtained for (methylcyclohexane + TBA + aromatic compounds). These results were correlated simultaneously by the UNIQUAC model. The values of the interaction parameters between each pair of components in the systems were obtained for the UNIQUAC model using the experimental result. The root mean square deviation (RMSD) between the observed and calculated mole percents was 1.88 for (methylcyclohexane + TBA + benzene), 2.45 for (methylcyclohexane + TBA + toluene) and 2.86 for (methylcyclohexane + TBA + ethylbenzene). The mutual solubility of methylcyclohexane and aromatic compounds (e.g., benzene toluene and ethylbenzene (BTE)) was also investigated by the addition of TBA at temperature of 298.2 K

  3. Crystal-liquid-gas phase transitions and thermodynamic similarity

    CERN Document Server

    Skripov, Vladimir P; Schmelzer, Jurn W P

    2006-01-01

    Professor Skripov obtained worldwide recognition with his monograph ""Metastable liquids"", published in English by Wiley & Sons. Based upon this work and another monograph published only in Russia, this book investigates the behavior of melting line and the properties of the coexisting crystal and liquid phase of simple substances across a wide range of pressures, including metastable states of the coexisting phases. The authors derive new relations for the thermodynamic similarity for liquid-vapour phase transition, as well as describing solid-liquid, liquid-vapor and liquid-liquid phase tra

  4. 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.

  5. Unconventional phase transitions in liquid crystals

    Science.gov (United States)

    Kats, E. I.

    2017-12-01

    According to classical textbooks on thermodynamics or statistical physics, there are only two types of phase transitions: continuous, or second-order, in which the latent heat L is zero, and first-order, in which L ≠ 0. Present-day textbooks and monographs also mention another, stand-alone type—the Berezinskii-Kosterlitz-Thouless transition, which exists only in two dimensions and shares some features with first- and second-order phase transitions. We discuss examples of non-conventional thermodynamic behavior (i.e., which is inconsistent with the theoretical phase transition paradigm now universally accepted). For phase transitions in smectic liquid crystals, mechanisms for nonconventional behavior are proposed and the predictions they imply are examined.

  6. Phase transitions in liquids with directed intermolecular bonding

    OpenAIRE

    Son, L.; Ryltcev, R.

    2005-01-01

    Liquids with quasi - chemical bonding between molecules are described in terms of vertex model. It is shown that this bonding results in liquid - liquid phase transition, which occurs between phases with different mean density of intermolecular bonds. The transition may be suggested to be a universal phenomena for those liquids.

  7. Liquid-liquid and liquid-solid phase separation and flocculation for a charged colloidal dispersion

    International Nuclear Information System (INIS)

    Lai, S.K.; Wu, K.L.

    2002-01-01

    We model the intercolloidal interaction by a hard-sphere Yukawa repulsion to which is added the long-range van der Waals attraction. In comparison with the Derjaguin-Landau-Verwey-Overbeek repulsion, the Yukawa repulsion explicitly incorporates the spatial correlations between colloids and small ions. As a result, the repulsive part can be expressed analytically and has a coupling strength depending on the colloidal volume fraction. By use of this two-body potential of mean force and in conjunction with a second-order thermodynamic perturbation theory, we construct the colloidal Helmholtz free energy and use it to calculate the thermodynamic quantities, pressure and chemical potential, needed in the determination of the liquid-liquid and liquid-solid phase diagrams. We examine, in an aqueous charged colloidal dispersion, the effects of the Hamaker constant and particle size on the conformation of a stable liquid-liquid phase transition calculated with respect to the liquid-solid coexistence phases. We find that there exists a threshold Hamaker constant or particle size whose value demarcates the stable liquid-liquid coexistence phases from their metastable counterparts. Applying the same technique and using the energetic criterion, we extend our calculations to study the flocculation phenomenon in aqueous charged colloids. Here, we pay due attention to determining the loci of a stability curve stipulated for a given temperature T 0 , and obtain the parametric phase diagram of the Hamaker constant vs the coupling strength or, at given surface potential, the particle size. By imposing T 0 to be the critical temperature T c , i.e., setting k B T 0 (=k B T c ) equal to a reasonable potential barrier, we arrive at the stability curve that marks the irreversible reversible phase transition. The interesting result is that there occurs a minimum size for the colloidal particles below (above) which the colloidal dispersion is driven to an irreversible (reversible) phase

  8. The new phases of liquid 3He

    International Nuclear Information System (INIS)

    Leggett, A.J.

    1976-01-01

    Comments are made on two new phases of liquid 3 He, referred to as 3 He-A and 3 He-B, discovered in the temperature region below 3 mk. It has been assumed that these new phases are anisotropic superfluids, and a general picture of them is presented, which has been successful in explaining at least qualitatively, many of the static, dynamic and transport properties of the new phases. Whilst the qualitative behaviour is in good agreement with theory there are, however, some quantitative discrepancies. In many cases these may be due to orientational and geometric effects not yet understood. One of the most fruitful areas for comparison of theory and experiment is the NMR behaviour and the dynamic nuclear magnetism. The anomalous behaviour observed arises because the nuclear dipole energy, although very small, can act coherently in the superfluid state. (U.K.)

  9. Non-contact optical Liquid Level Sensors

    Science.gov (United States)

    Kiseleva, L. L.; Tevelev, L. V.; Shaimukhametov, R. R.

    2016-06-01

    Information about characteristics of the optical liquid level sensor are present. Sensors are used to control of the light level limit fluid - water, kerosene, alcohol, solutions, etc. Intrinsically safe, reliable and easy to use. The operating principle of the level sensor is an optoelectronic infrared device.

  10. Glass phase expelling during liquid phase sintering of YSZ

    International Nuclear Information System (INIS)

    Souza, Milton Ferreira de; Souza, Dulcina Pinatti Ferreira de

    1998-01-01

    Expelling of the liquid phase during sintering of Zr O 2 -6.5 mol % Y 2 O 3 - 0.5 mol % Pr 2 O 3 ceramic was observed as a result of grain coarsening. ZrO 2 - 7.0 mol % Y 2 O 3 samples, without Pr 2 O 3 addition, do not show this effect under the same sintering conditions. The expelling process is caused by surface tension forces and attracting van der Waals forces between the grains, coupled with the existence of two glass phases on the grain boundaries. The amount of expelled glass phase increases with grain growth, but saturates above 16 μm average grain size. (author)

  11. Liquid phase hot atom chemistry: At crossroads

    International Nuclear Information System (INIS)

    Rack, E.P.; Veterans Administration Medical Center, Omaha, NE

    1981-01-01

    The state of current research in liquid phase hot atom chemistry is discussed. Four classes of experimental approaches are high-lighted. These include 1) primary physical data for (n,γ)-activated 128 I, (I.T.)-activated 130 I and effects on chemical reactivity; 2) the density-variation technique involving iodine reactions with saturated and unsaturated hydrocarbons; 3) stereochemistry experiments on chlorocarbon molecules with single and multiple chiral centers; and 4) experiments employing dilute aqueous solutions of halogenerated biomolecules in the ice state, exposed to neutron irradiation. (orig.) [de

  12. Commissioning of the XENON1T liquid level measurement system

    Energy Technology Data Exchange (ETDEWEB)

    Geis, Christopher [Institut fuer Physik, Johannes Gutenberg-Universitaet, Mainz (Germany)

    2016-07-01

    Two-phase xenon time projection chambers (TPCs) have been operated very successfully in direct detection experiments for dark matter. This kind of detector uses liquid xenon as the sensitive target and is operated in two-phase (liquid/gas) mode, where the liquid level needs to be monitored and controlled with sub-millimeter precision. We present the installation, commissioning and first measurement data of two kinds of level meters operated in the XENON1T TPC: short level meters are three-plated capacitors measuring the level of the liquid-gas interface with a measurement range h∼5 mm and a resolution of ΔC/h∼1 pF/mm. The long level meters are cylindrical double-walled capacitors, measuring the overall filling level of the XENON1T TPC at a measurement range of h=1.4 m and a resolution of ΔC/h∼0.1 pF/mm. Further, we present the design and programming of the readout electronic based on the UTI chip by Smartec, which allows to read all six levelmeters simultaneously.

  13. Gas flow headspace liquid phase microextraction.

    Science.gov (United States)

    Yang, Cui; Qiu, Jinxue; Ren, Chunyan; Piao, Xiangfan; Li, Xifeng; Wu, Xue; Li, Donghao

    2009-11-06

    There is a trend towards the use of enrichment techniques such as microextraction in the analysis of trace chemicals. Based on the theory of ideal gases, theory of gas chromatography and the original headspace liquid phase microextraction (HS-LPME) technique, a simple gas flow headspace liquid phase microextraction (GF-HS-LPME) technique has been developed, where the extracting gas phase volume is increased using a gas flow. The system is an open system, where an inert gas containing the target compounds flows continuously through a special gas outlet channel (D=1.8mm), and the target compounds are trapped on a solvent microdrop (2.4 microL) hanging on the microsyringe tip, as a result, a high enrichment factor is obtained. The parameters affecting the enrichment factor, such as the gas flow rate, the position of the microdrop, the diameter of the gas outlet channel, the temperatures of the extracting solvent and of the sample, and the extraction time, were systematically optimized for four types of polycyclic aromatic hydrocarbons. The results were compared with results obtained from HS-LPME. Under the optimized conditions (where the extraction time and the volume of the extracting sample vial were fixed at 20min and 10mL, respectively), detection limits (S/N=3) were approximately a factor of 4 lower than those for the original HS-LPME technique. The method was validated by comparison of the GF-HS-LPME and HS-LPME techniques using data for PAHs from environmental sediment samples.

  14. Nickel nanostructured materials from liquid phase photodeposition

    International Nuclear Information System (INIS)

    Giuffrida, Salvatore; Condorelli, Guglielmo G.; Costanzo, Lucia L.; Ventimiglia, Giorgio; Nigro, Raffaella Lo; Favazza, Maria; Votrico, Enrico; Bongiorno, Corrado; Fragala, Ignazio L.

    2007-01-01

    Liquid Phase Photo-Deposition (LPPD) technique has been used to obtain both colloidal particles and thin films of metallic and chloride nickel from solutions of only precursor Ni(acac) 2 (acac=2,4-pentandionato). Metallic nickel was obtained from ethanol solutions by direct nickel(II) photoreduction at 254 nm and by acetone sensitised reaction at 300 nm. In this latter process the rate was higher than in the first one. NiCl 2 was formed from CCl 4 solution by a solvent-initiated reaction. TEM analysis, performed on colloidal particles of nickel, showed that their dimensions are in the range 2-4 nm. The films did not present carbon contamination and were characterized by AFM, XPS and GIXRD. Metallic films consisted of particles of 20-40 nm that are the result of the aggregation of smaller crystallites (4-5 nm). Larger agglomerations (around 200 nm) have been observed for NiCl 2 films

  15. Surfactant mediated liquid phase exfoliation of graphene

    Science.gov (United States)

    Narayan, Rekha; Kim, Sang Ouk

    2015-10-01

    Commercialization of graphene based applications inevitably requires cost effective mass production. From the early days of research on graphene, direct liquid phase exfoliation (LPE) of graphite has been considered as the most promising strategy to produce high-quality mono or few-layer graphene sheets in solvent dispersion forms. Substantial success has been achieved thus far in the LPE of graphene employing numerous solvent systems and suitable surfactants. This invited review article principally showcase the recent research progress as well as shortcomings of surfactant assisted LPE of graphene. In particular, a comprehensive assessment of the quality and yield of the graphene sheets produced by different categories of the surfactants are summarized. Future direction of LPE methods is also proposed for the eventual success of commercial applications.

  16. Liquid phase exfoliated graphene for electronic applications

    Science.gov (United States)

    Sukumaran, Sheena S.; Jinesh, K. B.; Gopchandran, K. G.

    2017-09-01

    Graphene dispersions were prepared using the liquid phase exfoliation method with three different surfactants. One surfactant was used from each of the surfactant types, anionic, cationic, and non-ionic; those used, were sodium dodecylbenzene sulfonate (SDBS), cetyltrimethylammonium bromide (CTAB) and polyvinylpyrrolidone (PVP), respectively. Raman spectroscopy was used to investigate the number of layers and the nature of any defects present in the exfoliated graphene. The yield of graphene was found to be less with the non-ionic surfactant, PVP. The deconvolution of 2D peaks at ~2700 cm-1 indicated that graphene prepared using these surfactants resulted in sheets consisting of few-layer graphene. The ratio of intensity of the D and G bands in the Raman spectra showed that edge defect density is high for samples prepared with SDBS compared to the other two, and is attributed to the smaller size of the graphene sheets, as shown in the electron micrographs. In the case of the dispersion in PVP, it is found that the sizes of the graphene sheets are highly sensitive to the concentration of the surfactant used. Here, we have made an attempt to investigate the local density of states in the graphene sheets by measuring the tunnelling current-voltage characteristics. Graphene layers have shown consistent p-type behaviour when exfoliated with SDBS and n-type behaviour when exfoliated with CTAB, with a larger band gap for graphene exfoliated using CTAB. Hence, in addition to the known advantages of liquid phase exfoliation, we found that by selecting suitable surfactants, to a certain extent it is possible to tune the band gap and determine the type of majority carriers.

  17. Applications of low level liquid scintillation counting

    International Nuclear Information System (INIS)

    Noakes, J.E.

    1983-01-01

    Low level liquid scintillation counting is reviewed in terms of its present use and capabilities for measuring low activity samples. New areas of application of the method are discussed with special interest directed to the food industry and environmental monitoring. Advantages offered in the use of a low background liquid scintillation counter for the nuclear power industry and nuclear navy are discussed. Attention is drawn to the need for commercial development of such instrumentation to enable wider use of the method. A user clientele is suggested as is the required technology to create such a counter

  18. Glass-solidification method for high level radioactive liquid waste

    International Nuclear Information System (INIS)

    Kawamura, Kazuhiro; Kometani, Masayuki; Sasage, Ken-ichi.

    1996-01-01

    High level liquid wastes are removed with precipitates mainly comprising Mo and Zr, thereafter, the high level liquid wastes are mixed with a glass raw material comprising a composition having a B 2 O 3 /SiO 2 ratio of not less than 0.41, a ZnO/Li 2 O ratio of not less than 1.00, and an Al 2 O 3 /Li 2 O ratio of not less than 2.58, and they are melted and solidified into glass-solidification products. The liquid waste content in the glass-solidification products can be increased up to about 45% by using the glass raw material having such a predetermined composition. In addition, deposition of a yellow phase does not occur, and a leaching rate identical with that in a conventional case can be maintained. (T.M.)

  19. Monitoring PWR reactor vessel liquid level with SPNDs during LOCAs

    International Nuclear Information System (INIS)

    Adams, J.P.

    1982-01-01

    Data from in-core self-powered neutron detectors taken during two nuclear loss-of-coolant accident simulations have been correlated with core moderator density changes. The detector current attenuation has been calculated during blowdown and reflood phases of the simulation. Based on these data, it is concluded that these detectors could be used to monitor reactor vessel liquid level during loss-of-coolant accidents in pressurized water reactors

  20. Liquid-liquid phase transition and glass transition in a monoatomic model system.

    Science.gov (United States)

    Xu, Limei; Buldyrev, Sergey V; Giovambattista, Nicolas; Stanley, H Eugene

    2010-01-01

    We review our recent study on the polyamorphism of the liquid and glass states in a monatomic system, a two-scale spherical-symmetric Jagla model with both attractive and repulsive interactions. This potential with a parametrization for which crystallization can be avoided and both the glass transition and the liquid-liquid phase transition are clearly separated, displays water-like anomalies as well as polyamorphism in both liquid and glassy states, providing a unique opportunity to study the interplay between the liquid-liquid phase transition and the glass transition. Our study on a simple model may be useful in understanding recent studies of polyamorphism in metallic glasses.

  1. CATION-EXCHANGE SOLID-PHASE AND LIQUID-LIQUID ...

    African Journals Online (AJOL)

    B. S. Chandravanshi

    An existing liquid-liquid extraction (LLE) method was improved in terms of ... clean-up of the alkaloids from khat leaves, prior to HPLC-DAD detection. Despite .... The limits of detection (LOD) and quantification (LOQ) were calculated using the.

  2. Nickel nanostructured materials from liquid phase photodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Giuffrida, Salvatore, E-mail: sgiuffrida@unict.it; Condorelli, Guglielmo G.; Costanzo, Lucia L.; Ventimiglia, Giorgio [Universita degli Studi di Catania and INSTM UdR di, Dipartimento di Scienze Chimiche (Italy); Nigro, Raffaella Lo [IMM-CNR (Italy); Favazza, Maria; Votrico, Enrico [Universita degli Studi di Catania and INSTM UdR di, Dipartimento di Scienze Chimiche (Italy); Bongiorno, Corrado [IMM-CNR (Italy); Fragala, Ignazio L. [Universita degli Studi di Catania and INSTM UdR di, Dipartimento di Scienze Chimiche (Italy)

    2007-08-15

    Liquid Phase Photo-Deposition (LPPD) technique has been used to obtain both colloidal particles and thin films of metallic and chloride nickel from solutions of only precursor Ni(acac){sub 2} (acac=2,4-pentandionato). Metallic nickel was obtained from ethanol solutions by direct nickel(II) photoreduction at 254 nm and by acetone sensitised reaction at 300 nm. In this latter process the rate was higher than in the first one. NiCl{sub 2} was formed from CCl{sub 4} solution by a solvent-initiated reaction. TEM analysis, performed on colloidal particles of nickel, showed that their dimensions are in the range 2-4 nm. The films did not present carbon contamination and were characterized by AFM, XPS and GIXRD. Metallic films consisted of particles of 20-40 nm that are the result of the aggregation of smaller crystallites (4-5 nm). Larger agglomerations (around 200 nm) have been observed for NiCl{sub 2} films.

  3. Preliminary investigation of liquid phase sintering in ferrous systems

    International Nuclear Information System (INIS)

    Klein, J.

    1975-04-01

    Liquid phase sintering was utilized to achieve, by a simple compaction and sintering procedure involving short times and moderate temperatures, a virtually full dense high carbon Fe:C alloy and high boron Fe:B alloy. Parameters such as powder characteristics and mixing, compacting pressure, heating program and the liquid phase fraction were found to influence the sintered density. The response of the Fe:C alloy to a heat treatment is reported along with preliminary experiments in the iron base ternary system Fe:W:C. Residual porosities observed in microstructures of certain liquid phase sintered compacts were accounted for by a proposed capillary flow of the liquid phase and a local densification competing against an overall densification. Some general recommendations are made for liquid phase sintering of powder aggregates. 15 fig., 7 tables

  4. Simulation of Water Level Fluctuations in a Hydraulic System Using a Coupled Liquid-Gas Model

    Directory of Open Access Journals (Sweden)

    Chao Wang

    2015-08-01

    Full Text Available A model for simulating vertical water level fluctuations with coupled liquid and gas phases is presented. The Preissmann implicit scheme is used to linearize the governing equations for one-dimensional transient flow for both liquid and gas phases, and the linear system is solved using the chasing method. Some classical cases for single liquid and gas phase transients in pipelines and networks are studied to verify that the proposed methods are accurate and reliable. The implicit scheme is extended using a dynamic mesh to simulate the water level fluctuations in a U-tube and an open surge tank without consideration of the gas phase. Methods of coupling liquid and gas phases are presented and used for studying the transient process and interaction between the phases, for gas phase limited in a chamber and gas phase transported in a pipeline. In particular, two other simplified models, one neglecting the effect of the gas phase on the liquid phase and the other one coupling the liquid and gas phases asynchronously, are proposed. The numerical results indicate that the asynchronous model performs better, and are finally applied to a hydropower station with surge tanks and air shafts to simulate the water level fluctuations and air speed.

  5. A simple assay for the simultaneous determination of human plasma albendazole and albendazole sulfoxide levels by high performance liquid chromatography in tandem mass spectrometry with solid-phase extraction.

    Science.gov (United States)

    Wojnicz, Aneta; Cabaleiro-Ocampo, Teresa; Román-Martínez, Manuel; Ochoa-Mazarro, Dolores; Abad-Santos, Francisco; Ruiz-Nuño, Ana

    2013-11-15

    A simple, reproducible and fast (4 min chromatogram) method of liquid chromatography in tandem with mass spectrometry (LC/MS-MS) was developed to determine simultaneously the plasma levels of albendazole (ABZ) and its metabolite albendazole sulfoxide (ABZOX) for pharmacokinetic and clinical analysis. Each plasma sample was extracted by solid phase extraction (SPE) using phenacetin as internal standard (IS). The extracted sample was eluted with a Zorbax XDB-CN column using an isocratic method. The mobile phase consisting of water with 1% acetic acid (40%, A) and MeOH (60%, B), was used at a flow rate of 1 mL/min. ABZ and ABZOX were detected and identified by mass spectrometry with electrospray ionization (ESI) in the positive ion and multiple-reaction monitoring (MRM) mode. The method was linear in the range of 5-1000 ng/mL for ABZ and 10-1500 ng/mL (full validation) or 10-5000 ng/mL (partial validation) for ABZOX, with 5 and 10 ng/mL lower limit of quantification (LLOQ) for ABZ and ABZOX, respectively. The tests of accuracy and precision, matrix effect, extraction recovery and stability of the samples for both ABZ and ABZOX did not deviate more than 20% for the LLOQ and no more than 15% for other quality controls (QCs), according to regulatory agencies. © 2013.

  6. Liquid low level waste management expert system

    International Nuclear Information System (INIS)

    Ferrada, J.J.; Abraham, T.J.; Jackson, J.R.

    1991-01-01

    An expert system has been developed as part of a new initiative for the Oak Ridge National Laboratory (ORNL) systems analysis program. This expert system will aid in prioritizing radioactive waste streams for treatment and disposal by evaluating the severity and treatability of the problem, as well as the final waste form. The objectives of the expert system development included: (1) collecting information on process treatment technologies for liquid low-level waste (LLLW) that can be incorporated in the knowledge base of the expert system, and (2) producing a prototype that suggests processes and disposal technologies for the ORNL LLLW system. 4 refs., 9 figs

  7. Comparing two tetraalkylammonium ionic liquids. I. Liquid phase structure

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Thamires A.; Paschoal, Vitor H.; Faria, Luiz F. O.; Ribeiro, Mauro C. C., E-mail: mccribei@iq.usp.br [Laboratório de Espectroscopia Molecular, Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, CP 26077, CEP 05513-970 São Paulo, SP (Brazil); Giles, Carlos [Departamento de Física da Matéria Condensada, Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, 13083-859 Campinas, SP (Brazil)

    2016-06-14

    X-ray scattering experiments at room temperature were performed for the ionic liquids n-butyl-trimethylammonium bis(trifluoromethanesulfonyl)imide, [N{sub 1114}][NTf{sub 2}], and methyl-tributylammonium bis(trifluoromethanesulfonyl)imide, [N{sub 1444}][NTf{sub 2}]. The peak in the diffraction data characteristic of charge ordering in [N{sub 1444}][NTf{sub 2}] is shifted to longer distances in comparison to [N{sub 1114}][NTf{sub 2}], but the peak characteristic of short-range correlations is shifted in [N{sub 1444}][NTf{sub 2}] to shorter distances. Molecular dynamics (MD) simulations were performed for these ionic liquids using force fields available from the literature, although with new sets of partial charges for [N{sub 1114}]{sup +} and [N{sub 1444}]{sup +} proposed in this work. The shifting of charge and adjacency peaks to opposite directions in these ionic liquids was found in the static structure factor, S(k), calculated by MD simulations. Despite differences in cation sizes, the MD simulations unravel that anions are allowed as close to [N{sub 1444}]{sup +} as to [N{sub 1114}]{sup +} because anions are located in between the angle formed by the butyl chains. The more asymmetric molecular structure of the [N{sub 1114}]{sup +} cation implies differences in partial structure factors calculated for atoms belonging to polar or non-polar parts of [N{sub 1114}][NTf{sub 2}], whereas polar and non-polar structure factors are essentially the same in [N{sub 1444}][NTf{sub 2}]. Results of this work shed light on controversies in the literature on the liquid structure of tetraalkylammonium based ionic liquids.

  8. Measurements of liquid-phase turbulence in gas–liquid two-phase flows using particle image velocimetry

    International Nuclear Information System (INIS)

    Zhou, Xinquan; Doup, Benjamin; Sun, Xiaodong

    2013-01-01

    Liquid-phase turbulence measurements were performed in an air–water two-phase flow loop with a circular test section of 50 mm inner diameter using a particle image velocimetry (PIV) system. An optical phase separation method-–planar laser-induced fluorescence (PLIF) technique—which uses fluorescent particles and an optical filtration technique, was employed to separate the signals of the fluorescent seeding particles from those due to bubbles and other noises. An image pre-processing scheme was applied to the raw PIV images to remove the noise residuals that are not removed by the PLIF technique. In addition, four-sensor conductivity probes were adopted to measure the radial distribution of the void fraction. Two benchmark tests were performed: the first was a comparison of the PIV measurement results with those of similar flow conditions using thermal anemometry from previous studies; the second quantitatively compared the superficial liquid velocities calculated from the local liquid velocity and void fraction measurements with the global liquid flow rate measurements. The differences of the superficial liquid velocity obtained from the two measurements were bounded within ±7% for single-phase flows and two-phase bubbly flows with the area-average void fraction up to 18%. Furthermore, a preliminary uncertainty analysis was conducted to investigate the accuracy of the two-phase PIV measurements. The systematic uncertainties due to the circular pipe curvature effects, bubble surface reflection effects and other potential uncertainty sources of the PIV measurements were discussed. The purpose of this work is to facilitate the development of a measurement technique (PIV-PLIF) combined with image pre-processing for the liquid-phase turbulence in gas–liquid two-phase flows of relatively high void fractions. The high-resolution data set can be used to more thoroughly understand two-phase flow behavior, develop liquid-phase turbulence models, and assess high

  9. Phase-Shifting Liquid Crystal Interferometers for Microgravity Fluid Physics

    Science.gov (United States)

    Griffin, DeVon W.; Marshall, Keneth L.

    2002-01-01

    The initial focus of this project was to eliminate both of these problems in the Liquid Crystal Point-Diffraction Interferometer (LCPDI). Progress toward that goal will be described, along with the demonstration of a phase shifting Liquid Crystal Shearing Interferometer (LCSI) that was developed as part of this work. The latest LCPDI, other than a lens to focus the light from a test section onto a diffracting microsphere within the interferometer and a collimated laser for illumination, the pink region contained within the glass plates on the rod-mounted platform is the complete interferometer. The total width is approximately 1.5 inches with 0.25 inches on each side for bonding the electrical leads. It is 1 inch high and there are only four diffracting microspheres within the interferometer. As a result, it is very easy to align, achieving the first goal. The liquid crystal electro-optical response time is a function of layer thickness, with thinner devices switching faster due to a reduction in long-range viscoelastic forces between the LC molecules. The LCPDI has a liquid crystal layer thickness of 10 microns, which is controlled by plastic or glass microspheres embedded in epoxy 'pads' at the corners of the device. The diffracting spheres are composed of polystyrene/divinyl benzene polymer with an initial diameter of 15 microns. The spheres deform slightly when the interferometer is assembled to conform to the spacing produced by the microsphere-filled epoxy spacer pads. While the speed of this interferometer has not yet been tested, previous LCPDIs fabricated at the Laboratory for Laser Energetics switched at a rate of approximately 3.3 Hz, a factor of 10 slower than desired. We anticipate better performance when the speed of these interferometers is tested since they are approximately three times thinner. Phase shifting in these devices is a function of the AC voltage level applied to the liquid crystal. As the voltage increases, the dye in the liquid crystal

  10. Ionic Liquid Epoxy Composite Cryotanks, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this work is to determine the optimal process for manufacturing lightweight linerless cryogenic storage tanks using ionic liquid epoxy composite...

  11. Application of microwave irradiation to organic liquid phase reactions

    International Nuclear Information System (INIS)

    Huang Kun; Liu Hua; Ji Xuelin

    1994-01-01

    Microwave irradiation has been used in organic liquid phase reactions to significantly reduce the reaction time and improve the yield. The proposed mechanism, the development of techniques and reactions, such as Diels-Alder, ene, rearrangement reactions etc., are discussed

  12. Ultra-trace levels analysis of microcystins and nodularin in surface water by on-line solid-phase extraction with high-performance liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Balest, Lydia; Murgolo, Sapia; Sciancalepore, Lucia; Montemurro, Patrizia; Abis, Pier Paolo; Pastore, Carlo; Mascolo, Giuseppe

    2016-06-01

    An on-line solid phase extraction coupled with high-performance liquid chromatography in tandem with mass spectrometry (on-line SPE/HPLC/MS-MS) method for the determination of five microcystins and nodularin in surface waters at submicrogram per liter concentrations has been optimized. Maximum recoveries were achieved by carefully optimizing the extraction sample volume, loading solvent, wash solvent, and pH of the sample. The developed method was also validated according to both UNI EN ISO IEC 17025 and UNICHIM guidelines. Specifically, ten analytical runs were performed at three different concentration levels using a reference mix solution containing the six analytes. The method was applied for monitoring the concentrations of microcystins and nodularin in real surface water during a sampling campaign of 9 months in which the ELISA method was used as standard official method. The results of the two methods were compared showing good agreement when the highest concentration values of MCs were found. Graphical abstract An on-line SPE/HPLC/MS-MS method for the determination of five microcystins and nodularin in surface waters at sub μg L(-1) was optimized and compared with ELISA assay method for real samples.

  13. The liquid to vapor phase transition in excited nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, J.B.; Moretto, L.G.; Phair, L.; Wozniak, G.J.; Beaulieu, L.; Breuer, H.; Korteling, R.G.; Kwiatkowski, K.; Lefort, T.; Pienkowski, L.; Ruangma, A.; Viola, V.E.; Yennello, S.J.

    2001-05-08

    For many years it has been speculated that excited nuclei would undergo a liquid to vapor phase transition. For even longer, it has been known that clusterization in a vapor carries direct information on the liquid-vapor equilibrium according to Fisher's droplet model. Now the thermal component of the 8 GeV/c pion + 197 Au multifragmentation data of the ISiS Collaboration is shown to follow the scaling predicted by Fisher's model, thus providing the strongest evidence yet of the liquid to vapor phase transition.

  14. Highly Selective Continuous Gas-Phase Methoxycarbonylation of Ethylene with Supported Ionic Liquid Phase (SILP) Catalysts

    DEFF Research Database (Denmark)

    Khokarale, Santosh Govind; Garcia Suárez, Eduardo José; Fehrmann, Rasmus

    2017-01-01

    Supported ionic liquid phase (SILP) technology was applied for the first time to the Pd-catalyzed continuous, gas-phase methoxycarbonylation of ethylene to selectively produce methyl propanoate (MP) in high yields. The influence of catalyst and reaction parameters such as, for example, ionic liquid...

  15. Liquid-Liquid Phase Transition and Glass Transition in a Monoatomic Model System

    Directory of Open Access Journals (Sweden)

    Nicolas Giovambattista

    2010-12-01

    Full Text Available We review our recent study on the polyamorphism of the liquid and glass states in a monatomic system, a two-scale spherical-symmetric Jagla model with both attractive and repulsive interactions. This potential with a parametrization for which crystallization can be avoided and both the glass transition and the liquid-liquid phase transition are clearly separated, displays water-like anomalies as well as polyamorphism in both liquid and glassy states, providing a unique opportunity to study the interplay between the liquid-liquid phase transition and the glass transition. Our study on a simple model may be useful in understanding recent studies of polyamorphism in metallic glasses.

  16. Instructions for 104-SX liquid level measurement field tests

    International Nuclear Information System (INIS)

    Webb, R.H.

    1994-01-01

    This document provides detailed instructions for field testing a suggested solution of inserting a liner inside the 104-SX failed Liquid Observation Well to gain access for making temporary Liquid Level Measurement until a permanent solution has been provided

  17. Two-Order-Parameter Description of Liquids: Critical Phenomena and Phase Separation of Supercooled Liquids

    OpenAIRE

    Tanaka, Hajime

    1997-01-01

    Because of the isotropic and disordered nature of liquids, the anisotropy hidden in intermolecular interactions are often neglected. Accordingly, the order parameter describing a simple liquid has so far been believed to be only density. In contrast to this common sense, we propose that two order parameters, namely, density and bond order parameters, are required to describe the phase behavior of liquids since they intrinsically tend to form local bonds. This model gives us clear physical exp...

  18. Industrial aspects of gas-liquid two-phase flow

    International Nuclear Information System (INIS)

    Hewitt, G.F.

    1977-01-01

    The lecture begins by reviewing the various types of plant in which two phase flow occurs. Specifically, boiling plant, condensing plant and pipelines are reviewed, and the various two phase flow problems occurring in them are described. Of course, many other kinds of chemical engineering plant involve two phase flow, but are somewhat outside the scope of this lecture. This would include distillation columns, vapor-liquid separators, absorption towers etc. Other areas of industrial two phase flow which have been omitted for space reasons from this lecture are those concerned with gas/solids, liquid/solid and liquid/liquid flows. There then follows a description of some of the two phase flow processes which are relevant in industrial equipment and where special problems occur. The topics chosen are as follows: (1) pressure drop; (2) horizontal tubes - separation effects non-uniformites in heat transfer coefficient, effect of bends on dryout; (3) multicomponent mixtures - effects in pool boiling, mass transfer effects in condensation and Marangoni effects; (4) flow distribution - manifold problems in single phase flow, separation effects at a single T-junction in two phase flow and distribution in manifolds in two phase flow; (5) instability - oscillatory instability, special forms of instability in cryogenic systems; (6) nucleate boiling - effect of variability of surface, unresolved problems in forced convective nucleate boiling; and (7) shell side flows - flow patterns, cross flow boiling, condensation in cross flow

  19. Effect of Foam on Liquid Phase Mobility in Porous Media

    NARCIS (Netherlands)

    Eftekhari, A.A.; Farajzadeh, R.

    2017-01-01

    We investigate the validity of the assumption that foam in porous media reduces the mobility of gas phase only and does not impact the liquid-phase mobility. The foam is generated by simultaneous injection of nitrogen gas and a surfactant solution into sandstone cores and its strength is varied by

  20. Indication of liquid-liquid phase transition in CuZr-based melts

    DEFF Research Database (Denmark)

    Zhou, C.; Hu, L.N.; Sun, Q.J.

    2013-01-01

    We study the dynamic behavior of CuZr-based melts well above the liquidus temperature. The results show a discontinuous change in viscosity during cooling, which is attributed to an underlying liquid-liquid phase transition (LLPT) in these melts. The LLPT is further verified by thermodynamic...

  1. CO2 Capture with Liquid-Liquid Phase Change Solvents: A Thermodynamic Study

    DEFF Research Database (Denmark)

    Waseem Arshad, Muhammad; Fosbøl, Philip Loldrup; von Solms, Nicolas

    2017-01-01

    by the quaternary H2O-DEEAMAPA-CO2 system which gives liquid-liquid phase split when reacted with carbon dioxide. A total of 94 model parameters and 6 thermodynamic properties were fitted to approximately 1500 equilibrium and thermal experimental data consisting of pureamine vapor pressure (Pvap), vapor...

  2. Effect of Foam on Liquid Phase Mobility in Porous Media

    DEFF Research Database (Denmark)

    Eftekhari, Ali Akbar; Farajzadeh, R.

    2017-01-01

    We investigate the validity of the assumption that foam in porous media reduces the mobility of gas phase only and does not impact the liquid-phase mobility. The foam is generated by simultaneous injection of nitrogen gas and a surfactant solution into sandstone cores and its strength is varied...... by changing surfactant type and concentration. We find, indeed, that the effect of foam on liquid-phase mobility is not pronounced and can be ignored. Our new experimental results and analyses resolve apparent discrepancies in the literature. Previously, some researchers erroneously applied relative...

  3. Landau Levels of Majorana Fermions in a Spin Liquid.

    Science.gov (United States)

    Rachel, Stephan; Fritz, Lars; Vojta, Matthias

    2016-04-22

    Majorana fermions, originally proposed as elementary particles acting as their own antiparticles, can be realized in condensed-matter systems as emergent quasiparticles, a situation often accompanied by topological order. Here we propose a physical system which realizes Landau levels-highly degenerate single-particle states usually resulting from an orbital magnetic field acting on charged particles-for Majorana fermions. This is achieved in a variant of a quantum spin system due to Kitaev which is distorted by triaxial strain. This strained Kitaev model displays a spin-liquid phase with charge-neutral Majorana-fermion excitations whose spectrum corresponds to that of Landau levels, here arising from a tailored pseudomagnetic field. We show that measuring the dynamic spin susceptibility reveals the Landau-level structure by a remarkable mechanism of probe-induced bound-state formation.

  4. Electrically Tunable Reflective Terahertz Phase Shifter Based on Liquid Crystal

    Science.gov (United States)

    Yang, Jun; Xia, Tianyu; Jing, Shuaicheng; Deng, Guangsheng; Lu, Hongbo; Fang, Yong; Yin, Zhiping

    2018-02-01

    We present a reflective spatial phase shifter which operates at terahertz regime above 325 GHz. The controllable permittivity of the nematic liquid crystals was utilized to realize a tunable terahertz (THz) reflective phase shifter. The reflective characteristics of the terahertz electromagnetic waves and the liquid crystal parameters were calculated and analyzed. We provide the simulation results for the effect of the incident angle of the plane wave on the reflection. The experiment was carried out considering an array consisting of 30 × 30 patch elements, printed on a 20 × 20 mm quartz substrate with 1-mm thickness. The phase shifter provides a tunable phase range of 300° over the frequency range of 325 to 337.6 GHz. The maximum phase shift of 331° is achieved at 330 GHz. The proposed phase shifter is a potential candidate for THz applications, particularly for reconfigurable reflectarrays.

  5. Liquid crystal blue phases: stability, field effects and alignment

    OpenAIRE

    Gleeson, HF; Miller, RJ; Tian, L; Görtz, V; Goodby, JW

    2015-01-01

    The blue phases are fascinating structures in liquid crystals, fluids that exhibit cubic structures that have true crystalline order. The blue phases were discovered in the 1970s and were the subject of extensive research in the 1980s, when a deep understanding of many of their properties was established. The discovery that the blue phases could be stabilised to exist over wide temperature ranges meant that they became more than scientific curiosities and led to a recent resurgence in researc...

  6. Discontinuous structural phase transition of liquid metal and alloys (2)

    International Nuclear Information System (INIS)

    Wang, Li; Liu, Jiantong

    2004-01-01

    The diameter (d f ) of diffusion fluid cluster before and after phase transition has been calculated in terms of the paper ''Discontinuous structural phase transition of liquid metal and alloy (1)'' Physics Letters. A 326 (2004) 429-435, to verify quantitatively the discontinuity of structural phase transition; the phenomena of thermal contraction and thermal expansion during the phase transition, together with the evolution model of discontinuous structural phase transition are also discussed in this Letter to explore further the nature of structural transition; In addition, based on the viscosity experimental result mentioned in paper [Y. Waseda, The Structure of Non-Crystalline Materials--Liquids and Amorphous Solids, McGraw-Hill, New York, 1980], we present an approach to draw an embryo of the liquid-liquid (L-L) phase diagram for binary alloys above liquidus in the paper, expecting to guide metallurgy process so as to improve the properties of alloys. The idea that controls amorphous structure and its properties by means of the L-L phase diagram for alloys and by the rapid cooling technique to form the amorphous alloy has been brought forward in the end

  7. Vitrification of high-level liquid wastes

    International Nuclear Information System (INIS)

    Varani, J.L.; Petraitis, E.J.; Vazquez, Antonio.

    1987-01-01

    High-level radioactive liquid wastes produced in the fuel elements reprocessing require, for their disposal, a preliminary treatment by which, through a series of engineering barriers, the dispersion into the biosphere is delayed by 10 000 years. Four groups of compounds are distinguished among a great variety of final products and methods of elaboration. From these, the borosilicate glasses were chosen. Vitrification experiences were made at a laboratory scale with simulated radioactive wastes, employing different compositions of borosilicate glass. The installations are described. A series of tests were carried out on four basic formulae using always the same methodology, consisting of a dry mixture of the vitreous matrix's products and a dry simulated mixture. Several quality tests of the glasses were made 1: Behaviour in leaching following the DIN 12 111 standard; 2: Mechanical resistance; parameters related with the facility of the different glasses for increasing their surface were studied; 3: Degree of devitrification: it is shown that devitrification turns the glasses containing radioactive wastes easily leachable. From all the glasses tested, the composition SiO 2 , Al 2 O 3 , B 2 O 3 , Na 2 O, CaO shows the best retention characteristics. (M.E.L.) [es

  8. Observation of diffusion phenomena of liquid phase with multiple components

    International Nuclear Information System (INIS)

    Eguchi, Wataru

    1979-01-01

    The diffusion phenomena of liquid phase with multiple components was directly observed, and the factors contributing to complex material transfer were investigated, comparing to the former experimental results. The most excellent method of observing the diffusion behavior of liquid phase used heretofore is to trace the time history of concentration distribution for each component in unsteady diffusion process. The method of directly observing the concentration distribution is usually classified into the analysis of diffused samples, the checking of radioactive isotope tracers, and the measurement of light refraction and transmission. The most suitable method among these is to trace this time history by utilizing the spectrophotometer of position scanning type. An improved spectrophotometer was manufactured for trial. The outline of the measuring system and the detail of the optical system of this new type spectrophotometer are explained. The resolving power for position measurement is described with the numerical calculation. As for the observation examples of the diffusion phenomena of liquid phase with multiple components, the diffusion of multiple electrolytes in aqueous solution, the observation of the material transfer phenomena accompanied by heterogeneous and single phase chemical reaction, and the observation of concentration distribution in the liquid diaphragm in a reaction absorption system are described. For each experimental item, the test apparatus, the sample material, the test process, the test results and the evaluation are explained in detail, and the diffusion phenomena of liquid phase with multiple components were pretty well elucidated. (Nakai, Y.)

  9. Laser-induced microscopic phase-transition on an ionic liquid

    International Nuclear Information System (INIS)

    Iguchi, Natsuki; Datta, Alokmay; Yoshikawa, Kenichi; Ma Yue

    2009-01-01

    Nematic-isotropic transition is induced in a 5 μm 'droplet' within an oriented bulk of a mixture of a liquid crystalline material with a room-temperature ionic liquid, by a laser working at 532 nm with an output power of 200 mW and a beam diameter of 1 μm. No microscopic phase transition is observed either in absence of the ionic liquid or at the other wavelength of 1064 nm, available to the Nd-YAG laser. This indicates the essential role on a resonant transfer of energy to the ionic liquid from the laser radiation, which is subsequently transferred to the liquid crystal. Spectroscopy of the pure liquid crystal and ionic liquid samples confirms this concept. Spatio-temporal image of the droplet growth shows, however, that the phase transition remains confined within the microscopic domain for the first 50 s, and then spreads out rapidly. Since resonant, quantum transitions between molecular levels takes place in less than microseconds, the about seven orders of magnitude slowing down of energy transfer observed here suggests unique hierarchical dynamics including the coupling between the intra-molecular motions in the ionic liquid and the inter-molecular forces between ionic liquid and liquid crystal.

  10. The initial phase of sudden releases of superheated liquid

    International Nuclear Information System (INIS)

    Schmidli, J.

    1994-04-01

    The catastrophic failure of a pressure vessel containing a liquefied substance, leading to an instantaneous release of its whole contents is considered as one of the major technological hazards. Due to the rapid depressurization caused by vessel failure, the fluid becomes superheated and unstable. Part of the fluid will evaporate using its internal energy and the two-phase mixture forming will be accelerated. This flashing process can be very violent, as experiments and incidents actually happened have shown. In the past, a number of dispersion models were developed to predict the history of an instantaneous release. In most of these models the source term is considered to be a gas volume at rest and not a rapidly expanding aerosol, as could be observed. Furthermore, it is usually assumed that all of the remaining fluid is entrained into the expanding cloud and nothing is deposited on the ground to form a pool. This work concentrates on the initial phase of the sudden release of superheated liquids with the aim to gain a better understanding of the flashing process and of the physical mechanisms involved, leading to a reliable prediction of the source term. Therefore, more than 400 experiments with propane, butane, refrigerant 12 and 114 were conducted. The experiments were initiated by shattering spherical glass flasks of different sizes. The main parameters varied were the liquid superheat and the filling level of the vessel. Using high-speed video and movie recordings and very fast responding measurement devices, it was possible to study the initial phase of such releases during which gravity plays no role. For sufficiently large released internal energy, the initial evolution of the release was always spherical with a constant radial expansion velocity during he first milliseconds until instabilities appeared at the surface of the droplet/vapor cloud that was formed. For all the experimental conditions, the fraction of the initial liquid falling on the ground

  11. Diagnostical meaning acute phase proteins in cerebrospinal liquid in children with neuroinfections

    OpenAIRE

    L. A. Alekseeva; N. V. Skripchenko; T. V. Bessonova

    2010-01-01

    In the article presented results of the examination of acute phase proteins in cerebrospinal liquid in 237 children with meningitis and encephalitis viral and bacterial etiology. The dependence between the level of acute phase proteins in cerebrospinal liquid and etiology of neuroinfectional process, the severity of brain damage and the process stage was determined. Diagnostic and prognostic efficiency of the acute phase proteins (C-reactive protein, albumin, alpha-1-antitripsin, alpha-2-macr...

  12. Spatial heterogeneity in liquid–liquid phase transition

    International Nuclear Information System (INIS)

    Duan Yun-Rui; Li Tao; Wu Wei-Kang; Li Jie; Zhou Xu-Yan; Liu Si-Da; Li Hui

    2017-01-01

    Molecular dynamics simulations are performed to investigate the liquid–liquid phase transition (LLPT) and the spatial heterogeneity in Al–Pb monotectic alloys. The results reveal that homogeneous liquid Al–Pb alloy undergoes an LLPT, separating into Al-rich and Pb-rich domains, which is quite different from the isocompositional liquid water with a transition between low-density liquid (LDL) and high-density liquid (HDL). With spatial heterogeneity becoming large, LLPT takes place correspondingly. The relationship between the cooling rate, relaxation temperature and percentage of Al and the spatial heterogeneity is also reported. This study may throw light on the relationship between the structure heterogeneity and LLPT, which provides novel strategies to control the microstructures in the fabrication of the material with high performance. (paper)

  13. Quantum phase transitions in semilocal quantum liquids

    Science.gov (United States)

    Iqbal, Nabil; Liu, Hong; Mezei, Márk

    2015-01-01

    We consider several types of quantum critical phenomena from finite-density gauge-gravity duality which to different degrees lie outside the Landau-Ginsburg-Wilson paradigm. These include: (i) a "bifurcating" critical point, for which the order parameter remains gapped at the critical point, and thus is not driven by soft order parameter fluctuations. Rather it appears to be driven by "confinement" which arises when two fixed points annihilate and lose conformality. On the condensed side, there is an infinite tower of condensed states and the nonlinear response of the tower exhibits an infinite spiral structure; (ii) a "hybridized" critical point which can be described by a standard Landau-Ginsburg sector of order parameter fluctuations hybridized with a strongly coupled sector; (iii) a "marginal" critical point which is obtained by tuning the above two critical points to occur together and whose bosonic fluctuation spectrum coincides with that postulated to underly the "Marginal Fermi Liquid" description of the optimally doped cuprates.

  14. Radiation exposure rate and liquid level measurement inside a high level liquid waste (HLLW) storage tank

    International Nuclear Information System (INIS)

    Sur, B.; Yue, S.; Thekkevarriam, A.

    2007-01-01

    An instrument based on an inexpensive, small silicon diode has been developed and used to measure, for the first time, the gamma radiation exposure rate profile inside a 6.4 mm diameter reentrant thermo-well tube, immersed in the highly radioactive liquid solution in an HLLW storage tank. The measurement agrees with previous calculations of exposure rate, and provides confirmation for safe and effective radiation work plans and material selection for investigations and remediation of the storage tank facility. The measured radiation exposure rate profile is also used to confirm that the position of tank internal structures have not changed because of aging and corrosion, and to obtain, within a few mm, the level of liquid inside the tank. (author)

  15. Laser-induced partial oxidation of cyclohexane in liquid phase

    International Nuclear Information System (INIS)

    Oshima, Y.; Wu, X.W.; Koda, S.

    1995-01-01

    A laser-induced partial oxidation of cyclohexane was studied in the liquid phase. With KrF excimer laser (248 nm) irradiation to neat liquid cyclohexane in which O 2 was dissolved, cyclohexanol and cyclohexanone were obtained with very high selectivities, together with cyclohexane as a minor product. Radical recombination reactions to produce dicyclohexyl ether and bicyclohexyl also took place, while these products were not observed in the gas phase reaction. These experimental results were considered to be due not only to higher concentration of cyclohexane but to the cage effect in the liquid phase oxidation. To clarify the reaction progress including the photoabsorption process, the effects of laser intensity and O 2 pressure on product distribution were studied. (author)

  16. Characterisation of GERDA Phase-I detectors in liquid argon

    Energy Technology Data Exchange (ETDEWEB)

    Barnabe Heider, Marik; Schoenert, Stefan [Max-Planck-Institut fuer Kernphysik (Germany); Gusev, Konstantin [Russian Research Center, Kurchatov Institute (Russian Federation); Joint Institute for Nuclear Research (Russian Federation)

    2009-07-01

    GERDA will search for neutrinoless double beta decay in {sup 76}Ge by submerging bare enriched HPGe detectors in liquid argon. In GERDA Phase-I, reprocessed enriched-Ge detectors, which were previously operated by the Heidelberg-Moscow and IGEX collaborations, and reprocessed natural-Ge detectors from Genius-TF, will be redeployed. We have tested the operation and performance of bare HPGe detectors in liquid nitrogen and in liquid argon over more than three years with three non-enriched p-type prototype detectors. The detector handling and mounting procedures have been defined and the Phase-I detector technology, the low-mass assembly and the long-term stability in liquid argon have been tested successfully. The Phase-I detectors were reprocessed by Canberra Semiconductor NV, Olen, according to their standard technology but without the evaporation of a passivation layer. After their reprocessing, the detectors have been mounted in their low-mass holders and their characterisation in liquid argon performed. The leakage current, the counting characteristics and the efficiency of the detectors have been measured. The testing of the detectors was carried out in the liquid argon test stand of the GERDA underground Detector Laboratory (GDL) at LNGS. The detectors are now stored underground under vacuum until their operation in GERDA.

  17. 2D director calculation for liquid crystal optical phased array

    International Nuclear Information System (INIS)

    Xu, L; Zhang, J; Wu, L Y

    2005-01-01

    A practical numerical model for a liquid crystal cell is set up based on the geometrical structure of liquid crystal optical phased arrays. Model parameters include width and space of electrodes, thickness of liquid crystal layer, alignment layers and glass substrates, pre-tilted angles, dielectric constants, elastic constants and so on. According to electrostatic field theory and Frank-Oseen elastic continuum theory, 2D electric potential distribution and 2D director distribution are calculated by means of the finite difference method on non-uniform grids. The influence of cell sizes on director distribution is analyzed. The fringe field effect between electrodes is also discussed

  18. Determination of sulfonamides in butter samples by ionic liquid magnetic bar liquid-phase microextraction high-performance liquid chromatography.

    Science.gov (United States)

    Wu, Lijie; Song, Ying; Hu, Mingzhu; Xu, Xu; Zhang, Hanqi; Yu, Aimin; Ma, Qiang; Wang, Ziming

    2015-01-01

    A novel, simple, and environmentally friendly pretreatment method, ionic liquid magnetic bar liquid-phase microextraction, was developed for the determination of sulfonamides in butter samples by high-performance liquid chromatography. The ionic liquid magnetic bar was prepared by inserting a stainless steel wire into the hollow of a hollow fiber and immobilizing ionic liquid in the micropores of the hollow fiber. In the extraction process, the ionic liquid magnetic bars were used to stir the mixture of sample and extraction solvent and enrich the sulfonamides in the mixture. After extraction, the analyte-adsorbed ionic liquid magnetic bars were readily isolated with a magnet from the extraction system. It is notable that the present method was environmentally friendly since water and only several microliters of ionic liquid were used in the whole extraction process. Several parameters affecting the extraction efficiency were investigated and optimized, including the type of ionic liquid, sample-to-extraction solvent ratio, the number of ionic liquid magnetic bars, extraction temperature, extraction time, salt concentration, stirring speed, pH of the extraction solvent, and desorption conditions. The recoveries were in the range of 73.25-103.85 % and the relative standard deviations were lower than 6.84 %. The experiment results indicated that the present method was effective for the extraction of sulfonamides in high-fat content samples.

  19. A new liquid-phase-separation glaze containing neodymium oxide

    International Nuclear Information System (INIS)

    Jing, S.; Xianque, C.; Luxing, K.; Pentecost, J.L.

    1986-01-01

    A color-changeable opaque glaze containing neodymium oxide was investigated. Results show that the glaze is a new example of the liquid-phase-separation type. The discrete phase droplets are from 50 to 500 nm in size. They are rich in Nd, Zn, Ca, and Mg and the continuous phase is rich in Si, Al, and K. The concentration of the discrete phase is approx. =45%. The large number of discrete droplets and the zinc oxide in the glaze increase its opacity to cover the selective light absorption and scattering of the neodymium ion and reduce the opalescence effect

  20. The initial phase of sudden releases of superheated liquid

    International Nuclear Information System (INIS)

    Schmidli, J.; Yadigaroglu, G.

    1994-01-01

    Series of experiments were conducted with refrigerants-114, -12, propane and butane to investigate the initial phase of sudden releases of superheated liquids due to the catastrophic failure of the vessel containing them. The experiments were initiated by shattering spherical flasks of 100 to 2000 ml containing the liquefied, pressurized gases. The variable parameters were the initial superheat, the filling level, the height of the flask above ground, and the relative humidity of the surrounding air. It was found that the initial flashing process is not determined by homogeneous nucleation, but rather by surface instabilities which lead to an evaporation wave traveling from the initial surface towards the center of the released mass. Cloud shape and expansion velocity could be determined from high speed recordings covering the initial stage of the release during which gravity has no influence. When the internal energy was sufficient, it was observed that the expanding droplet/vapor cloud initially propagated spherically with a constant expansion velocity, until Rayleigh-Taylor type instabilities appeared at its surface. Information about the pool which can be formed on the ground, the pressure decay within the flask, the droplet size, and the cloud temperature was collected. The experimental findings for the expansion velocity, as well as for the pool fraction, were the base for a nondimensional analysis leading to correlations which describe the initial phase of such releases and can be used to define the ''source term'' for turbulent dispersion models. (author) 5 figs., 1 tab., 15 refs

  1. Phase separation and structure formation in gadolinium based liquid and glassy metallic alloys

    International Nuclear Information System (INIS)

    Han, Junhee

    2014-01-01

    tailored both at microscopic and macroscopic length scales. This includes either droplet-like or interconnected microstructures at the microscopic level and glass-glass or glass-crystalline composites at the macroscopic level. Essential parameter for the quenched in microstructure is the temperature dependence of liquid-liquid phase separation, which is determined by the chemical composition of the alloy: on the one hand, earlier and/or later stages of spinodal decomposition or almost homogeneous glassy states are obtained if the critical temperature of miscibility gap T c is close to the glass transition temperature T g ; and on the one hand, coarsening and secondary precipitations of the liquids are obtained if T c is much higher than T g . Finally, the influence of the microstructure developed by phase separation on their magnetic properties had been investigated. The saturation magnetization σ S depends on the overall amount of Gd atoms in the alloys and is not remarkably affected by phase separation processes. The Curie temperature T Curie of the magnetic transition is influenced by the changed chemical composition of the Gd-rich glassy phases compared to that of monolithic Gd-Co-Al glasses.

  2. FORTRAN program for calculating liquid-phase and gas-phase thermal diffusion column coefficients

    International Nuclear Information System (INIS)

    Rutherford, W.M.

    1980-01-01

    A computer program (COLCO) was developed for calculating thermal diffusion column coefficients from theory. The program, which is written in FORTRAN IV, can be used for both liquid-phase and gas-phase thermal diffusion columns. Column coefficients for the gas phase can be based on gas properties calculated from kinetic theory using tables of omega integrals or on tables of compiled physical properties as functions of temperature. Column coefficients for the liquid phase can be based on compiled physical property tables. Program listings, test data, sample output, and users manual are supplied for appendices

  3. Method of processing low-level radioactive liquid wastes

    International Nuclear Information System (INIS)

    Matsunaga, Ichiro; Sugai, Hiroshi.

    1984-01-01

    Purpose: To effectively reduce the radioactivity density of low-level radioactive liquid wastes discharged from enriched uranium conversion processing steps or the likes. Method: Hydrazin is added to low-level radioactive liquid wastes, which are in contact with iron hydroxide-cation exchange resins prepared by processing strongly acidic-cation exchange resins with ferric chloride and aqueous ammonia to form hydrorizates of ferric ions in the resin. Hydrazine added herein may be any of hydrazine hydrate, hydrazine hydrochloride and hydranine sulfate. The preferred addition amount is more than 100 mg per one liter of the liquid wastes. If it is less than 100 mg, the reduction rate for the radioactivety density (procession liquid density/original liquid density) is decreased. This method enables to effectively reduce the radioactivity density of the low-level radioactive liquid wastes containing a trace amount of radioactive nucleides. (Yoshihara, H.)

  4. Surface-bonded ionic liquid stationary phases in high-performance liquid chromatography--a review.

    Science.gov (United States)

    Pino, Verónica; Afonso, Ana M

    2012-02-10

    Ionic liquids (ILs) are a class of ionic, nonmolecular solvents which remain in liquid state at temperatures below 100°C. ILs possess a variety of properties including low to negligible vapor pressure, high thermal stability, miscibility with water or a variety of organic solvents, and variable viscosity. IL-modified silica as novel high-performance liquid chromatography (HPLC) stationary phases have attracted considerable attention for their differential behavior and low free-silanol activity. Indeed, around 21 surface-confined ionic liquids (SCIL) stationary phases have been developed in the last six years. Their chromatographic behavior has been studied, and, despite the presence of a positive charge on the stationary phase, they showed considerable promise for the separation of neutral solutes (not only basic analytes), when operated in reversed phase mode. This aspect points to the potential for truly multimodal stationary phases. This review attempts to summarize the state-of-the-art about SCIL phases including their preparation, chromatographic behavior, and analytical performance. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Liquid-liquid phase separation in internally mixed magnesium sulfate/glutaric acid particles

    Science.gov (United States)

    Wu, Feng-Min; Wang, Xiao-Wei; Jing, Bo; Zhang, Yun-Hong; Ge, Mao-Fa

    2018-04-01

    The confocal Raman microscopy is utilized to investigate the liquid-liquid phase separation (LLPS) of mixed magnesium sulfate/glutaric acid (MgSO4/GA) droplets deposited on a hydrophobic polytetrafluoroethylene (PTFE) substrate and a hydrophilic quartz substrate. Raman spectra collected from different regions of the mixed droplets provide detailed information of component distributions for MgSO4 and GA. During the dehydration process, the MgSO4/GA mixed particles show the initial liquid-liquid phase separation between 85% and 80% relative humidity (RH) on both the hydrophobic and hydrophilic substrates. For the droplets deposited on the two substrates, the inner phase of droplets is dominated by aqueous MgSO4, which is surrounded by a rich GA organic layer due to the surface tension effects. In addition, the crystallization of GA could be observed in the organic aqueous phase while it is inhibited in the inner MgSO4 phase due to the effects of gel formation of MgSO4 at low RH. The Raman spectra reveal that with decreasing RH the morphology of the mixed droplet evolves from a uniform droplet to the structure of LLPS with the GA crystallizing in the outer layer and MgSO4 gel formed in the inner phase. These findings contribute to the further understanding of the role of interactions between inorganic salts and organic acids on the morphological evolution and environmental effects of atmospheric aerosols under ambient RH conditions.

  6. Growth of high purity semiconductor epitaxial layers by liquid phase ...

    Indian Academy of Sciences (India)

    Unknown

    semiconductor materials in high purity form by liquid phase epitaxy (LPE) technique. Various possible sources of impurities in such ... reference to the growth of GaAs layers. The technique of growing very high purity layers ... the inner walls of the gas lines and (e) the containers for storing, handling and cleaning of the mate-.

  7. Frustrated smectic liquid crystalline phases in lactic acid derivatives

    Czech Academy of Sciences Publication Activity Database

    Glogarová, Milada; Novotná, Vladimíra

    2016-01-01

    Roč. 89, č. 7-8 (2016), s. 829-839 ISSN 0141-1594 R&D Projects: GA ČR GA15-02843S Institutional support: RVO:68378271 Keywords : field * liquid crystals * TGB phases Subject RIV: JJ - Other Materials Impact factor: 1.060, year: 2016

  8. Investigations on the liquid crystalline phases of cation-induced ...

    Indian Academy of Sciences (India)

    liquid crystalline phases of Li–DNA system could be useful in the production of ... undergo unidirectional ordering (the solution starts to become birefringent under ... was spread over the glass slides with a cover slip and sealed with a neutral ...

  9. Monitoring aged reversed-phase high performance liquid chromatography columns

    NARCIS (Netherlands)

    Bolck, A; Smilde, AK; Bruins, CHP

    1999-01-01

    In this paper, a new approach for the quality assessment of routinely used reversed-phase high performance liquid chromatography columns is presented. A used column is not directly considered deteriorated when changes in retention occur. If attention is paid to the type and magnitude of the changes,

  10. Liquid-phase separation with the rotational particle separator

    NARCIS (Netherlands)

    Kemenade, van H.P.; Mondt, E.; Hendriks, A.J.A.M.; Verbeek, P.H.J.

    2003-01-01

    Recently, the rotational particle separator (RPS) was introduced as a new technique for separating solid and/or liquid particles of 0.1 m and larger from gases. In this patented technique the principles of centrifugation are exploited to enhance separation of small-sized phases and particulate

  11. High purity liquid phase epitaxial gallium arsenide nuclear radiation detector

    International Nuclear Information System (INIS)

    Alexiev, D.; Butcher, K.S.A.

    1991-11-01

    Surface barrier radiation detector made from high purity liquid phase epitaxial gallium arsenide wafers have been operated as X- and γ-ray detectors at various operating temperatures. Low energy isotopes are resolved including 241 Am at 40 deg C. and the higher gamma energies of 235 U at -80 deg C. 15 refs., 1 tab., 6 figs

  12. Solid-Phase Extraction Combined with High Performance Liquid ...

    African Journals Online (AJOL)

    Methods: Solid-phase extraction method was employed for the extraction of the estrogen from milk and high performance liquid chromatography-diode array detector (HPLC-DAD) was used for the determination of estrogen. Results: Optimal chromatographic conditions were achieved on an Eclipse XDB-C18 column at a ...

  13. Numerical simulation on stir system of jet ballast in high level liquid waste storage tank

    International Nuclear Information System (INIS)

    Lu Yingchun

    2012-01-01

    The stir system of jet ballast in high level liquid waste storage tank was simulation object. Gas, liquid and solid were air, sodium nitrate liquor and titanium whitening, respectively. The mathematic model based on three-fluid model and the kinetic theory of particles was established for the stir system of jet ballast in high level liquid waste storage tank. The CFD commercial software was used for solving this model. The detail flow parameters as three phase velocity, pressure and phase loadings were gained. The calculated results agree with the experimental results, so they can well define the flow behavior in the tank. And this offers a basic method for the scale-up and optimization design of the stir system of jet ballast in high level liquid waste storage tank. (author)

  14. Structural crossover in a supercooled metallic liquid and the link to a liquid-to-liquid phase transition

    Energy Technology Data Exchange (ETDEWEB)

    Lan, S.; Ma, J. L.; Fan, J. [Department of Physics and Material Science, City University of Hong Kong 83 Tat Chee Ave., Kowloon (Hong Kong); Blodgett, M.; Kelton, K. F. [Department of Physics and Institute of Materials Science and Engineering, Washington University One Brookings Drive, St. Louis, Missouri 63130-4899 (United States); Wang, X.-L., E-mail: xlwang@cityu.edu.hk [Department of Physics and Material Science, City University of Hong Kong 83 Tat Chee Ave., Kowloon (Hong Kong); City University of Hong Kong Shenzhen Research Institute, Shenzhen 518057 (China)

    2016-05-23

    Time-resolved synchrotron measurements were carried out to capture the structure evolution of an electrostatically levitated metallic-glass-forming liquid during free cooling. The experimental data shows a crossover in the liquid structure at ∼1000 K, about 115 K below the melting temperature and 150 K above the crystallization temperature. The structure change is characterized by a dramatic growth in the extended-range order below the crossover temperature. Molecular dynamics simulations have identified that the growth of the extended-range order was due to an increased correlation between solute atoms. These results provide structural evidence for a liquid-to-liquid-phase-transition in the supercooled metallic liquid.

  15. Acidic ionic liquids for n-alkane isomerization in a liquid-liquid or slurry-phase reaction mode

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, C.; Hager, V.; Geburtig, D.; Kohr, C.; Wasserscheid, P. [Erlangen-Nuernberg Univ. (Germany). Lehrstuhl fuer Chemische Reaktionstechnik; Haumann, M. [Chemical Reaction Engineering, FAU Busan Campus, Korea (Korea, Republic of)

    2011-07-01

    Highly acidic ionic liquid (IL) catalysts offer the opportunity to convert n-alkanes at very low reaction temperatures. The results of IL catalyzed isomerization and cracking reactions of pure n-octane are presented. Influence of IL composition, [C{sub 4}C{sub 1}Im]Cl / AlCl{sub 3} / H{sub 2}SO{sub 4} and [C{sub 4}C{sub 1}Im]Cl / AlCl{sub 3} / 1-chlorooctane, on catalyst activity and selectivities to branched alkanes was investigated. Acidic chloroaluminate IL catalysts form liquid-liquid biphasic systems with unpolar organic product mixtures. Thus, recycling of the acidic IL is enabled by simple phase separation in the liquid-liquid biphasic reaction mode or the IL can be immobilized on an inorganic support with a large specific surface area. These supported ionic liquid phase (SILP) catalysts offer the advantage to get a macroscopically heterogeneous system while still preserving all benefits of the homogeneous catalyst which can be used for the slurry-phase n-alkane isomerization. The interaction of the solid support and acidic IL influences strongly the catalytic activity. (orig.)

  16. Profile of MIBI liquid phase radiopharmaceutical for myocardial imaging

    International Nuclear Information System (INIS)

    I Daruwati; ME Sriyani; NK Oekar; N Zainuddin; KA Hanafiah

    2016-01-01

    The 99m Tc-MIBI radiopharmaceutical has been used in nuclear medicine in Indonesia for myocardial imaging. BATAN researchers have mastered the technology to manufacture MIBI as a lyophilized kit. A reformulation of MIBI radiopharmaceutical has been conducted to improve the stability of the kit especially in the liquid-phase kit. Basically, radiopharmaceuticals in liquid form are not different from the dry kit. However in the manufacturing of liquid-phase kit, lyophilization process was not done. To improve the stability of liquid kit, a reformulation of the components was conducted by using two separate vials (Formulation 2) and the characteristics were compared with the one-vial formulation (Formulation 1). The MIBI Formulation 2 consists of two vials, vial A containing 0.06 mg of SnCl 2 2H 2 O and 2.6 mg Sodium Citrate 2H 2 O and vial B containing 0.5 mg of [Cu(MIBI) 4 ]BF 4 , 1 mg of cysteine hydrochloride, and 20 mg of mannitol. The purposes of this study were to determine the stability of two different formulations of MIBI as a liquid-phase kit, to compare their stability in different storage condition such as in refrigerator and freezer, and to compare the ratio of activities attained between target and nontarget organs after injection to animal model. As a diagnostic agent, MIBI was reconstituted with Technetium-99m as radionuclide tracer to 99m Tc-MIBI labeled compound. The radiochemical purity of 99m Tc-MIBI was determined by chromatography method using alumina thin-layer chromatography paper as the stationary phase and ethanol 95% as the mobile phase. The results showed MIBI Formulation 2 has a higher stability than Formulation 1. Formulation 2 also maintained a 96.68% radiochemical purity under 52-day storage and attained a target-to-nontarget activity ratio of 8.22. (author)

  17. Cone-shaped membrane liquid phase micro extraction

    International Nuclear Information System (INIS)

    Hong, Heng See; Sanagi, M.M.; Ibrahim, W.A.W.; Naim, A.A.

    2008-01-01

    A novel sample pre-treatment technique termed cone-shaped membrane liquid phase micro extraction (CSM-LPME) was developed and combined with micro-liquid chromatography (micro-LC) for the determination of selected pesticides in water samples. Several important extraction parameters such as types of extraction solvent, agitation rate, pH value, total exposure time and effect of salt and humic acids were investigated and optimized. Enrichment factors of >50 folds were easily achieved within 20 min of extraction. The new developed method demonstrated an excellent performance in terms of speed, cost effectiveness, reproducibility, as well as exceptional low detection limits. Current work provides a great interest to further investigate on the applicability of the CSM-LPME technique in analytical chemistry and explores the possibility of replacing conventional extraction techniques such as soxhlet, solid phase extraction (SPE) and solid phase micro extraction (SPME). (author)

  18. Liquid Phase Sintering of Highly Alloyed Stainless Steel

    DEFF Research Database (Denmark)

    Mathiesen, Troels

    1996-01-01

    Liquid phase sintering of stainless steel is usually applied to improve corrosion resistance by obtaining a material without an open pore system. The dense structure normally also give a higher strength when compared to conventional sintered steel. Liquid phase sintrering based on addition...... of boride to AISI 316L type steels have previously been studied, but were found to be sensitive to intergranular corrosion due to formation of intermetallic phases rich in chromium and molybdenum. In order to improve this system further, new investigations have focused on the use of higher alloyed stainless...... steel as base material. The stainless base powders were added different amounts and types of boride and sintered in hydrogen at different temperatures and times in a laboratory furnace. During sintering the outlet gas was analyzed and subsequently related to the obtained microstructure. Thermodynamic...

  19. Lyotropic liquid crystalline phase behaviour in amphiphile-protic ionic liquid systems.

    Science.gov (United States)

    Chen, Zhengfei; Greaves, Tamar L; Fong, Celesta; Caruso, Rachel A; Drummond, Calum J

    2012-03-21

    Approximate partial phase diagrams for nine amphiphile-protic ionic liquid (PIL) systems have been determined by synchrotron source small angle X-ray scattering, differential scanning calorimetry and cross polarised optical microscopy. The binary phase diagrams of some common cationic (hexadecyltrimethyl ammonium chloride, CTAC, and hexadecylpyridinium bromide, HDPB) and nonionic (polyoxyethylene (10) oleyl ether, Brij 97, and Pluronic block copolymer, P123) amphiphiles with the PILs, ethylammonium nitrate (EAN), ethanolammonium nitrate (EOAN) and diethanolammonium formate (DEOAF), have been studied. The phase diagrams were constructed for concentrations from 10 wt% to 80 wt% amphiphile, in the temperature range 25 °C to >100 °C. Lyotropic liquid crystalline phases (hexagonal, cubic and lamellar) were formed at high surfactant concentrations (typically >50 wt%), whereas at thermal stability of the phases formed by these surfactants persisted to temperatures above 100 °C. The phase behaviour of amphiphile-PIL systems was interpreted by considering the PIL cohesive energy, liquid nanoscale order, polarity and ionicity. For comparison the phase behaviour of the four amphiphiles was also studied in water.

  20. Liquid chromatography tandem mass spectrometry determination of total budesonide levels in dog plasma after inhalation exposure.

    Science.gov (United States)

    Berg, Seija; Melamies, Marika; Rajamäki, Minna; Vainio, Outi; Peltonen, Kimmo

    2012-01-01

    A sensitive and selective method to quantify budesonide in dog plasma samples was developed and fully validated. Liquid-liquid extraction was followed by solid-phase extraction and liquid chromatography-tandem mass spectrometry with electrospray ionization. After reconstitution of the analytes in the mobile phase, samples were analysed by reversed-phase liquid chromatography with isocratic elution. d8-Budesonide was used as an internal standard, and characteristic transitions of d8-budesonide and budesonide were used for quantification. The method was validated with respect to selectivity, specificity, linearity, recovery, repeatability, reproducibility and limits of detection and quantification. The validated method was successfully applied to monitor the plasma levels of budesonide in dogs exposed to clinical doses of inhaled and intravenous drug.

  1. LOFT liquid level transducer application techniques and measurement uncertainty

    International Nuclear Information System (INIS)

    Batt, D.L.; Biladeau, G.L.; Goodrich, L.D.; Nightingale, C.M.

    1979-01-01

    A conductivity sensitive liquid level transducer (LLT) has been designed and used successfully for determining whether steam or water is present in the Loss-of-Fluid Tests (LOFT) performed by EG and G Idaho, Inc., at the Idaho National Engineering Laboratory. The presence of steam or water is determined by establishing a discriminator level which is set manually. A computer program establishes the presence or absence of water for each data point taken. In addition to liquid level, the LLT is used for reactor vessel mass and volume calculations. The uncertainty in the liquid level is essentially the spacing of the LLT electrodes

  2. Modeling the gas-particle partitioning of secondary organic aerosol: the importance of liquid-liquid phase separation

    Directory of Open Access Journals (Sweden)

    A. Zuend

    2012-05-01

    Full Text Available The partitioning of semivolatile organic compounds between the gas phase and aerosol particles is an important source of secondary organic aerosol (SOA. Gas-particle partitioning of organic and inorganic species is influenced by the physical state and water content of aerosols, and therefore ambient relative humidity (RH, as well as temperature and organic loading levels. We introduce a novel combination of the thermodynamic models AIOMFAC (for liquid mixture non-ideality and EVAPORATION (for pure compound vapor pressures with oxidation product information from the Master Chemical Mechanism (MCM for the computation of gas-particle partitioning of organic compounds and water. The presence and impact of a liquid-liquid phase separation in the condensed phase is calculated as a function of variations in relative humidity, organic loading levels, and associated changes in aerosol composition. We show that a complex system of water, ammonium sulfate, and SOA from the ozonolysis of α-pinene exhibits liquid-liquid phase separation over a wide range of relative humidities (simulated from 30% to 99% RH. Since fully coupled phase separation and gas-particle partitioning calculations are computationally expensive, several simplified model approaches are tested with regard to computational costs and accuracy of predictions compared to the benchmark calculation. It is shown that forcing a liquid one-phase aerosol with or without consideration of non-ideal mixing bears the potential for vastly incorrect partitioning predictions. Assuming an ideal mixture leads to substantial overestimation of the particulate organic mass, by more than 100% at RH values of 80% and by more than 200% at RH values of 95%. Moreover, the simplified one-phase cases stress two key points for accurate gas-particle partitioning calculations: (1 non-ideality in the condensed phase needs to be considered and (2 liquid-liquid phase separation is a consequence of considerable deviations

  3. Ultrasonic level indicator for liquids and its application

    International Nuclear Information System (INIS)

    Kanngiesser, P.

    1976-01-01

    Ultrasonic level indicator for liquids where a piezo-element is used to reverse the piezoelectric effect may be applied in a more versatile way if the indicator is provided with a reflector. It becomes less susceptible to faults and may be used for all liquids, including liquid metals. The piezo-element may then be used at the same time as receiver for ultrasonic waves emitted previously and, in that case, echoed back by the refelctor. (UWI) [de

  4. Liquid-phase and solid-phase radioimmunoassay with herpes simplex virus type 1 nucleocapsids

    International Nuclear Information System (INIS)

    Bystricka, M.; Rajcani, J.; Libikova, H.; Sabo, A.; Foeldes, O.; Sadlon, J.

    1985-01-01

    Liquid-phase radioimmunoassay and solid-phase radioimmunoassay are described using 125 I-labelled or immobilized nucleocapsids (NC) of herpes simplex virus (HSV) type1. These techniques appeared sensitive and specific for quantitation of HSV-NC antigens and corresponding antibodies. (author)

  5. Continuous gas-phase hydroformylation of 1-butene using supported ionic liquid phase (SILP) catalysts

    DEFF Research Database (Denmark)

    Haumann, Marco; Dentler, Katharina; Joni, Joni

    2007-01-01

    The concept of supported ionic liquid phase (SILP) catalysis has been extended to 1-butene hydroformylation. A rhodium-sulfoxantphos complex was dissolved in [BMIM][n-C8H17OSO3] and this solution was highly dispersed on silica. Continuous gas-phase experiments in a fixed-bed reactor revealed...

  6. Vapor phase versus liquid phase grafting of meso-porous alumina

    NARCIS (Netherlands)

    Sripathi, V.G.P.; Mojet, Barbara; Nijmeijer, Arian; Benes, Nieck Edwin

    2013-01-01

    Functionalization of meso-porous c-alumina has been performed by grafting of 3-Aminopropyltrimethoxysilane (3APTMS) simultaneously from either the liquid phase or from the vapor phase. In both cases, after grafting nitrogen physisorption indicates that the materials remain meso-porous with

  7. Determination of Pb2+ metal ion level in liquid waste from adsorption process by combination adsorbent of rice husk and water hyacinth charcoal using solid-phase spectrophotometry (sps)

    Science.gov (United States)

    Saputro, S.; Masykuri, M.; Mahardiani, L.; Hidayah, AN

    2018-03-01

    This research are to find out the influence of adsorbent composition between rice husk and water hyacinth in decreasing of Pb2+ ion in simulation liquid waste; the optimumcomposition of combination adsorbent of rice husk and water hyacinth charcoal on Pb2+ ion adsorption; and theeffectivenessof SPS as a method to determine the decreasing level of Pb2+ ion in simulation liquid waste by combination adsorbent of rice husk and water hyacinth charcoal in µg/L level. Rice husk and water hyacinth carbonization using muffle furnace at 350°C for 1 hour. Rice husk charcoal activation in a 2 N NaOH solution and water hyacinth charcoal activated in a 5 M HCl solution. Contacting the combination adsorbent of rice husk and water hyacinth charcoal with a Pb2+ solution with variation of mass composition, 1:0 ; 0:1 ; 1:1 ; 1:2 and 2:1. Analysis of the Pb2+ ion level using SPS method. Characterization of rice husk and water hyacinth charcoal using the FTIR. The results showed that the combination adsorbent composition of rice husk and water hyacinth charcoal have an impact on decreasing Pb2+ ion level. The optimum composition of combination adsorbent of rice husk and water hyacinth charcoal on the adsorption Pb2+ ion is 1:2. SPS is an effective method to determine the decreasing Pb2+ ion in simulation liquid waste from the adsorption process by combination adsorbent of rice husk and water hyacinth in µg/L, with Limit of Detection (LOD) was 0,06 µg/L.

  8. Diagnostical meaning acute phase proteins in cerebrospinal liquid in children with neuroinfections

    Directory of Open Access Journals (Sweden)

    L. A. Alekseeva

    2010-01-01

    Full Text Available In the article presented results of the examination of acute phase proteins in cerebrospinal liquid in 237 children with meningitis and encephalitis viral and bacterial etiology. The dependence between the level of acute phase proteins in cerebrospinal liquid and etiology of neuroinfectional process, the severity of brain damage and the process stage was determined. Diagnostic and prognostic efficiency of the acute phase proteins (C-reactive protein, albumin, alpha-1-antitripsin, alpha-2-macroglobulin, gaptoglobin examination in children with neuroinfections was specified. Developed method of express diagnostics of the severity of inflammatory damage of the brain in bacterial meningitis in children by determination in cerebrospinal liquid alpha-2-macroglobulin is described.

  9. Water Phase Diagram Is Significantly Altered by Imidazolium Ionic Liquid

    DEFF Research Database (Denmark)

    Chaban, V. V.; Prezhdo, O. V.

    2014-01-01

    We report unusually large changes in the boiling temperature, saturated vapor pressure, and structure of the liquid-vapor interface for a range of 1-butyl-3-methyl tetrafluoroborate, [C4C1IM][BF4]-water mixtures. Even modest molar fractions of [C4C1IM][BF4] significantly affect the phase behavior...... of water, as represented, for instance, by strong negative deviations from Raoult's law, extending far beyond the standard descriptions. The investigation was carried out using classical molecular dynamics employing a specifically refined force field. The changes in the liquid-vapor interface and saturated...

  10. Horizontal liquid film-mist two phase flow, (1)

    International Nuclear Information System (INIS)

    Akagawa, Koji; Sakaguchi, Tadashi; Fujii, Terushige; Nakatani, Yoji; Nakaseko, Kosaburo.

    1979-01-01

    The characteristics of liquid film in annular spray flow, the generation of droplets from liquid film and the transport of droplets to a wall are the important matters in the planning and design of nuclear reactor cooling system and the channels of steam generators. The study on the liquid film spray flow is scarce, and its characteristics are not yet elucidated. The purpose of this series of studies is to clarify the characteristics of liquid film, the generation, diffusion and distribution of droplets and pressure loss in the liquid film spray flow composed of the liquid film on the lower wall and spraying gas flow in a rectangular, horizontal channel. In this paper, the concentration distribution and the diffusion coefficient of droplets on a cross section in the region of flow completion are reported. The experimental apparatuses and the experimental method, the flow rate of droplets and the velocity distribution of gas phase, the concentration distribution and the diffusion coefficient of droplets, and the diameter of generated droplets are explained. The equation for the concentration distribution of droplets using dimensionless characteristic value was derived. The mean diffusion coefficient of droplets was constant on a cross section, and the effects of gravity and turbulent diffusion can be evaluated. (Kako, I.)

  11. Plasmas in Multiphase Media: Bubble Enhanced Discharges in Liquids and Plasma/Liquid Phase Boundaries

    Energy Technology Data Exchange (ETDEWEB)

    Kushner, Mark Jay [University of Michigan

    2014-07-10

    In this research project, the interaction of atmospheric pressure plasmas with multi-phase media was computationally investigated. Multi-phase media includes liquids, particles, complex materials and porous surfaces. Although this investigation addressed fundamental plasma transport and chemical processes, the outcomes directly and beneficially affected applications including biotechnology, medicine and environmental remediation (e.g., water purification). During this project, we made advances in our understanding of the interaction of atmospheric pressure plasmas in the form of dielectric barrier discharges and plasma jets with organic materials and liquids. We also made advances in our ability to use computer modeling to represent these complex processes. We determined the method that atmospheric pressure plasmas flow along solid and liquid surfaces, and through endoscopic like tubes, deliver optical and high energy ion activation energy to organic and liquid surfaces, and produce reactivity in thin liquid layers, as might cover a wound. We determined the mechanisms whereby plasmas can deliver activation energy to the inside of liquids by sustaining plasmas in bubbles. These findings are important to the advancement of new technology areas such as plasma medicine

  12. Phase stability analysis of liquid-liquid equilibrium with stochastic methods

    Directory of Open Access Journals (Sweden)

    G. Nagatani

    2008-09-01

    Full Text Available Minimization of Gibbs free energy using activity coefficient models and nonlinear equation solution techniques is commonly applied to phase stability problems. However, when conventional techniques, such as the Newton-Raphson method, are employed, serious convergence problems may arise. Due to the existence of multiple solutions, several problems can be found in modeling liquid-liquid equilibrium of multicomponent systems, which are highly dependent on the initial guess. In this work phase stability analysis of liquid-liquid equilibrium is investigated using the NRTL model. For this purpose, two distinct stochastic numerical algorithms are employed to minimize the tangent plane distance of Gibbs free energy: a subdivision algorithm that can find all roots of nonlinear equations for liquid-liquid stability analysis and the Simulated Annealing method. Results obtained in this work for the two stochastic algorithms are compared with those of the Interval Newton method from the literature. Several different binary and multicomponent systems from the literature were successfully investigated.

  13. Glass and liquid phase diagram of a polyamorphic monatomic system

    Science.gov (United States)

    Reisman, Shaina; Giovambattista, Nicolas

    2013-02-01

    We perform out-of-equilibrium molecular dynamics (MD) simulations of a monatomic system with Fermi-Jagla (FJ) pair potential interactions. This model system exhibits polyamorphism both in the liquid and glass state. The two liquids, low-density (LDL) and high-density liquid (HDL), are accessible in equilibrium MD simulations and can form two glasses, low-density (LDA) and high-density amorphous (HDA) solid, upon isobaric cooling. The FJ model exhibits many of the anomalous properties observed in water and other polyamorphic liquids and thus, it is an excellent model system to explore qualitatively the thermodynamic properties of such substances. The liquid phase behavior of the FJ model system has been previously characterized. In this work, we focus on the glass behavior of the FJ system. Specifically, we perform systematic isothermal compression and decompression simulations of LDA and HDA at different temperatures and determine "phase diagrams" for the glass state; these phase diagrams varying with the compression/decompression rate used. We obtain the LDA-to-HDA and HDA-to-LDA transition pressure loci, PLDA-HDA(T) and PHDA-LDA(T), respectively. In addition, the compression-induced amorphization line, at which the low-pressure crystal (LPC) transforms to HDA, PLPC-HDA(T), is determined. As originally proposed by Poole et al. [Phys. Rev. E 48, 4605 (1993)], 10.1103/PhysRevE.48.4605 simulations suggest that the PLDA-HDA(T) and PHDA-LDA(T) loci are extensions of the LDL-to-HDL and HDL-to-LDL spinodal lines into the glass domain. Interestingly, our simulations indicate that the PLPC-HDA(T) locus is an extension, into the glass domain, of the LPC metastability limit relative to the liquid. We discuss the effects of compression/decompression rates on the behavior of the PLDA-HDA(T), PHDA-LDA(T), PLPC-HDA(T) loci. The competition between glass polyamorphism and crystallization is also addressed. At our "fast rate," crystallization can be partially suppressed and the

  14. Liquid hydrogen transfer pipes and level regulation systems

    International Nuclear Information System (INIS)

    Marquet, M.; Prugne, P.; Roubeau, P.

    1961-01-01

    Describes: 1) Transfer pipes - Plunging rods in liquid hydrogen Dewars; transfer pipes: knee-joint system for quick and accurate positioning of plunging Dewar rods; system's rods: combined valve and rod; valves are activated either by a bulb pressure or by a solenoid automatically or hand controlled. The latter allows intermittent filling. 2) Level regulating systems: Level bulbs: accurate to 1 or 4 m; maximum and minimum level bulbs: automatic control of the liquid hydrogen valve. (author) [fr

  15. Light Path Model of Fiber Optic Liquid Level Sensor Considering Residual Liquid Film on the Wall

    Directory of Open Access Journals (Sweden)

    Zhijun Zhang

    2015-01-01

    Full Text Available The working principle of the refractive-type fiber optic liquid level sensor is analyzed in detail based on the light refraction principle. The optic path models are developed in consideration of common simplification and the residual liquid film on the glass tube wall. The calculating formulae for the model are derived, constraint conditions are obtained, influencing factors are discussed, and the scopes and skills of application are analyzed through instance simulations. The research results are useful in directing the correct usage of the fiber optic liquid level sensor, especially in special cases, such as those involving viscous liquid in the glass tube monitoring.

  16. Pharmaceutical Perspective on Opalescence and Liquid-Liquid Phase Separation in Protein Solutions.

    Science.gov (United States)

    Raut, Ashlesha S; Kalonia, Devendra S

    2016-05-02

    Opalescence in protein solutions reduces aesthetic appeal of a formulation and can be an indicator of the presence of aggregates or precursor to phase separation in solution signifying reduced product stability. Liquid-liquid phase separation of a protein solution into a protein-rich and a protein-poor phase has been well-documented for globular proteins and recently observed for monoclonal antibody solutions, resulting in physical instability of the formulation. The present review discusses opalescence and liquid-liquid phase separation (LLPS) for therapeutic protein formulations. A brief discussion on theoretical concepts based on thermodynamics, kinetics, and light scattering is presented. This review also discusses theoretical concepts behind intense light scattering in the vicinity of the critical point termed as "critical opalescence". Both opalescence and LLPS are affected by the formulation factors including pH, ionic strength, protein concentration, temperature, and excipients. Literature reports for the effect of these formulation factors on attractive protein-protein interactions in solution as assessed by the second virial coefficient (B2) and the cloud-point temperature (Tcloud) measurements are also presented. The review also highlights pharmaceutical implications of LLPS in protein solutions.

  17. Going full circle: phase-transition thermodynamics of ionic liquids.

    Science.gov (United States)

    Preiss, Ulrich; Verevkin, Sergey P; Koslowski, Thorsten; Krossing, Ingo

    2011-05-27

    We present the full enthalpic phase transition cycle for ionic liquids (ILs) as examples of non-classical salts. The cycle was closed for the lattice, solvation, dissociation, and vaporization enthalpies of 30 different ILs, relying on as much experimental data as was available. High-quality dissociation enthalpies were calculated at the G3 MP2 level. From the cycle, we could establish, for the first time, the lattice and solvation enthalpies of ILs with imidazolium ions. For vaporization, lattice, and dissociation enthalpies, we also developed new prediction methods in the course of our investigations. Here, as only single-ion values need to be calculated and the tedious optimization of an ion pair can be circumvented, the computational time is short. For the vaporization enthalpy, a very simple approach was found, using a surface term and the calculated enthalpic correction to the total gas-phase energy. For the lattice enthalpy, the most important constituent proved to be the calculated conductor-like screening model (COSMO) solvation enthalpy in the ideal electric conductor. A similar model was developed for the dissociation enthalpy. According to our assessment, the typical error of the lattice enthalpy would be 9.4 kJ mol(-1), which is less than half the deviation we get when using the (optimized) Kapustinskii equation or the recent volume-based thermodynamics (VBT) theory. In contrast, the non-optimized VBT formula gives lattice enthalpies 20 to 140 kJ mol(-1) lower than the ones we assessed in the cycle, because of the insufficient description of dispersive interactions. Our findings show that quantum-chemical calculations can greatly improve the VBT approaches, which were parameterized for simple, inorganic salts with ideally point-shaped charges. In conclusion, we suggest the term "augmented VBT", or "aVBT", to describe this kind of theoretical approach. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Migration of carbon nanotubes from liquid phase to vapor phase in the refrigerant-based nanofluid pool boiling

    Directory of Open Access Journals (Sweden)

    Peng Hao

    2011-01-01

    Full Text Available Abstract The migration characteristics of carbon nanotubes from liquid phase to vapor phase in the refrigerant-based nanofluid pool boiling were investigated experimentally. Four types of carbon nanotubes with the outside diameters from 15 to 80 nm and the lengths from 1.5 to 10 μm were used in the experiments. The refrigerants include R113, R141b and n-pentane. The oil concentration is from 0 to 10 wt.%, the heat flux is from 10 to 100 kW·m-2, and the initial liquid-level height is from 1.3 to 3.4 cm. The experimental results indicate that the migration ratio of carbon nanotube increases with the increase of the outside diameter or the length of carbon nanotube. For the fixed type of carbon nanotube, the migration ratio decreases with the increase of the oil concentration or the heat flux, and increases with the increase of the initial liquid-level height. The migration ratio of carbon nanotube increases with the decrease of dynamic viscosity of refrigerant or the increase of liquid phase density of refrigerant. A model for predicting the migration ratio of carbon nanotubes in the refrigerant-based nanofluid pool boiling is proposed, and the predictions agree with 92% of the experimental data within a deviation of ±20%.

  19. Immobilization of molecular catalysts in supported ionic liquid phases.

    Science.gov (United States)

    Van Doorslaer, Charlie; Wahlen, Joos; Mertens, Pascal; Binnemans, Koen; De Vos, Dirk

    2010-09-28

    In a supported ionic liquid phase (SILP) catalyst system, an ionic liquid (IL) film is immobilized on a high-surface area porous solid and a homogeneous catalyst is dissolved in this supported IL layer, thereby combining the attractive features of homogeneous catalysts with the benefits of heterogeneous catalysts. In this review reliable strategies for the immobilization of molecular catalysts in SILPs are surveyed. In the first part, general aspects concerning the application of SILP catalysts are presented, focusing on the type of catalyst, support, ionic liquid and reaction conditions. Secondly, organic reactions in which SILP technology is applied to improve the performance of homogeneous transition-metal catalysts are presented: hydroformylation, metathesis reactions, carbonylation, hydrogenation, hydroamination, coupling reactions and asymmetric reactions.

  20. Problems of selectivity in liquid-phase oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Emanuel, N M

    1978-07-01

    Based on a kinetic analysis of a generalized scheme for radical-chain process and on published experimental results, factors determining the selectivities of various liquid-phase oxidations of organic compounds are examined, including the kinetic chain length, molecular and chain decomposition of products, and competing routes in the initiated oxidation or autoxidation of hydrocarbons to peroxides. Also discussed are selective inhibition of undesirable routes in chain reactions, e.g., styrene and acetaldehyde co-oxidation; activation of molecular oxygen by variable-valence metal compounds used as homogeneous catalysts; modeling of fermentative processes by oxidation of hydrocarbons in complex catalytic systems, e.g., hydroxylation of alkanes, epoxidation or carbonylation of olefins, or oxidation of alcohols and ketones to acids; and the mechanisms of heterogeneous catalysis in liquid-phase reactions, e.g., oxidation of alkylaromatic hydrocarbons to peroxides and co-oxidation of propylene and acetaldehyde.

  1. Liquid phase oxidation chemistry in continuous-flow microreactors.

    Science.gov (United States)

    Gemoets, Hannes P L; Su, Yuanhai; Shang, Minjing; Hessel, Volker; Luque, Rafael; Noël, Timothy

    2016-01-07

    Continuous-flow liquid phase oxidation chemistry in microreactors receives a lot of attention as the reactor provides enhanced heat and mass transfer characteristics, safe use of hazardous oxidants, high interfacial areas, and scale-up potential. In this review, an up-to-date overview of both technological and chemical aspects of liquid phase oxidation chemistry in continuous-flow microreactors is given. A description of mass and heat transfer phenomena is provided and fundamental principles are deduced which can be used to make a judicious choice for a suitable reactor. In addition, the safety aspects of continuous-flow technology are discussed. Next, oxidation chemistry in flow is discussed, including the use of oxygen, hydrogen peroxide, ozone and other oxidants in flow. Finally, the scale-up potential for continuous-flow reactors is described.

  2. Preconcentration in gas or liquid phases using adsorbent thin films

    Directory of Open Access Journals (Sweden)

    Antonio Pereira Nascimento Filho

    2006-03-01

    Full Text Available The possibility of preconcentration on microchannels for organic compounds in gas or liquid phases was evaluated. Microstructures with different geometries were mechanically machined using poly(methyl methacrylate - PMMA as substrates and some cavities were covered with cellulose. The surfaces of the microchannels were modified by plasma deposition of hydrophilic or hydrophobic films using 2-propanol and hexamethyldisilazane (HMDS, respectively. Double layers of HMDS + 2-propanol were also used. Adsorption characterization was made by Quartz Crystal Measurements (QCM technique using reactants in a large polarity range that showed the adsorption ability of the structures depends more on the films used than on the capillary phenomena. Cellulose modified by double layer film showed a high retention capacity for all gaseous compounds tested. However, structures without plasma deposition showed low retention capacity. Microchannels modified with double layers or 2-propanol plasma films showed higher retention than non-modified ones on gas or liquid phase.

  3. Vitrification and Crystallization of Phase-Separated Metallic Liquid

    Directory of Open Access Journals (Sweden)

    Yun Cheng

    2017-02-01

    Full Text Available The liquid–liquid phase separation (LLPS behavior of Fe50Cu50 melt from 3500 K to 300 K with different rapid quenching is investigated by molecular dynamics (MD simulation based on the embedded atom method (EAM. The liquid undergoes metastable phase separation by spinodal decomposition in the undercooled regime and subsequently solidifies into three different Fe-rich microstructures: the interconnected-type structure is kept in the glass and crystal at a higher cooling rate, while the Fe-rich droplets are found to crystalize at a lower cooling rate. During the crystallization process, only Fe-rich clusters can act as the solid nuclei. The twinning planes can be observed in the crystal and only the homogeneous atomic stacking shows mirror symmetry along the twinning boundary. Our present work provides atomic-scale understanding of LLPS melt during the cooling process.

  4. Powder metallurgy: Solid and liquid phase sintering of copper

    Science.gov (United States)

    Sheldon, Rex; Weiser, Martin W.

    1993-01-01

    Basic powder metallurgy (P/M) principles and techniques are presented in this laboratory experiment. A copper based system is used since it is relatively easy to work with and is commercially important. In addition to standard solid state sintering, small quantities of low melting metals such as tin, zinc, lead, and aluminum can be added to demonstrate liquid phase sintering and alloy formation. The Taguchi Method of experimental design was used to study the effect of particle size, pressing force, sintering temperature, and sintering time. These parameters can be easily changed to incorporate liquid phase sintering effects and some guidelines for such substitutions are presented. The experiment is typically carried out over a period of three weeks.

  5. Core-shell particle composition by liquid phase infrared spectroscopy

    International Nuclear Information System (INIS)

    Ribeiro, Luiz F.B.; Machado, Ricardo A.F.; Goncalves, Odinei H.; Bona, Evandro

    2011-01-01

    Polymeric particles with core-shell morphology can offer advantages over conventional particles improving properties like mechanical and chemical resistance. However, particle composition must be known due to its influence on the final properties. In this work liquid phase infrared spectroscopy was used to determine the overall composition of core-shell particles composed by polystyrene (core) and poly(methyl methacrylate) (shell). Results were in agreement with those obtained with H 1 Nuclear Magnetic Resonance data (Goncalves et al, 2008). (author)

  6. A review of liquid-phase catalytic hydrodechlorination

    OpenAIRE

    Alba Nelly Ardila Arias; Consuelo Montes de Correa

    2007-01-01

    This survey was aimed at introducing the effect of light organochlorinated compound emissions on the envi-ronment, particularly on water, air, soil, biota and human beings. The characteristics and advantages of liquid phase catalytic hydrodechlorination as a technology for degrading these chlorinated compounds is also outlined and the main catalysts used in the hydrodechlorination process are described. Special emphasis is placed on palladium catalysts, their activity, the nature of active sp...

  7. Radiation-induced trioxane postpolymerization in the liquid phase

    International Nuclear Information System (INIS)

    Kapustina, I.B.; Starchenko, T.V.

    1979-01-01

    Radiation-induced trioxane postpolymerization in the presence of maleic anhydride and different solvents in the liquid phase has been studied. It has been found that addition of small quantities of different solvents inhibits the trioxane polymerization process both in the presence of maleic anhydride and in the absence of it. Trioxane postpolymerization in a solvent-nonsolvent mixture gives fibrous polyoxymethylene with high molecular mass and high yield

  8. Shock wave of vapor-liquid two-phase flow

    Institute of Scientific and Technical Information of China (English)

    Liangju ZHAO; Fei WANG; Hong GAO; Jingwen TANG; Yuexiang YUAN

    2008-01-01

    The shock wave of vapor-liquid two-phase flow in a pressure-gain steam injector is studied by build-ing a mathematic model and making calculations. The results show that after the shock, the vapor is nearly com-pletely condensed. The upstream Mach number and the volume ratio of vapor have a great effect on the shock. The pressure and Mach number of two-phase shock con-form to the shock of ideal gas. The analysis of available energy shows that the shock is an irreversible process with entropy increase.

  9. Electronic circuit provides automatic level control for liquid nitrogen traps

    Science.gov (United States)

    Turvy, R. R.

    1968-01-01

    Electronic circuit, based on the principle of increased thermistor resistance corresponding to decreases in temperature provides an automatic level control for liquid nitrogen cold traps. The electronically controlled apparatus is practically service-free, requiring only occasional reliability checks.

  10. Cement encapsulation of low-level waste liquids. Final report

    International Nuclear Information System (INIS)

    Baker, M.N.; Houston, H.M.

    1999-01-01

    Pretreatment of liquid high-level radioactive waste at the West Valley Demonstration Project (WVDP) was essential to ensuring the success of high-level waste (HLW) vitrification. By chemically separating the HLW from liquid waste, it was possible to achieve a significant reduction in the volume of HLW to be vitrified. In addition, pretreatment made it possible to remove sulfates, which posed several processing problems, from the HLW before vitrification took place

  11. New Type Multielectrode Capacitance Sensor for Liquid Level

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Y R [China University of Petroleum (Huadong), Qingdao (China); Shi, A P [Shandong University of Science and Technology, Qingdao (China); Chen, G Q [Shandong University of Science and Technology, Qingdao (China); Chang, Y Y [Shandong University of Science and Technology, Qingdao (China); Hang, Z [Shandong University of Science and Technology, Qingdao (China); Liu, B M [Binzhou University, Binzhou (China)

    2006-10-15

    This paper introduces the design of a new type multielectrode capacitance sensor for liquid level. The system regards electric field sensor MC33794 as the core and applies microcontroller MC9S12DJ128 to realize intelligent liquid level monitoring system, which overcomes the disadvantages of the traditional capacitance sensor, improves on the anti-jamming ability and the measurement precision and simplifies the system structure. Finally, the paper sums up the design of the system.

  12. Vibrational relaxation in liquids: Comparisons between gas phase and liquid phase theories

    International Nuclear Information System (INIS)

    Russell, D.J.

    1990-12-01

    The vibrational relaxation of iodine in liquid xenon was studied to understand what processes are important in determining the density dependence of the vibrational relaxation. This examination will be accomplished by taking simple models and comparing the results to both experimental outcomes and the predictions of molecular dynamics simulations. The vibration relaxation of iodine is extremely sensitive to the iodine potential. The anharmonicity of iodine causes vibrational relaxation to be much faster at the top of the iodine well compared to the vibrational relaxation at the bottom. A number of models are used in order to test the ability of the Isolated Binary Collision theory's ability to predict the density dependence of the vibrational relaxation of iodine in liquid xenon. The models tested vary from the simplest incorporating only the fact that the solvent occupies volume to models that incorporate the short range structure of the liquid in the radial distribution function. None of the models tested do a good job of predicting the actual relaxation rate for a given density. This may be due to a possible error in the choice of potentials to model the system

  13. Ginzburg-Landau equation and vortex liquid phase of Fermi liquid superconductors

    International Nuclear Information System (INIS)

    Ng, T-K; Tse, W-T

    2007-01-01

    In this paper we study the Ginzburg-Landau (GL) equation for Fermi liquid superconductors with strong Landau interactions F 0s and F 1s . We show that Landau interactions renormalize two parameters entering the GL equation, leading to the renormalization of the compressibility and superfluid density. The renormalization of the superfluid density in turn leads to an unconventional (2D) Berezinskii-Kosterlitz-Thouless (BKT) transition and vortex liquid phase. Application of the GL equation to describe underdoped high-T c cuprates is discussed

  14. Surfactant-enhanced liquid-liquid microextraction coupled to micro-solid phase extraction onto highly hydrophobic magnetic nanoparticles

    International Nuclear Information System (INIS)

    Giannoulis, Kiriakos M.; Giokas, Dimosthenis L.; Tsogas, George Z.; Vlessidis, Athanasios G.; Zhu, Qing; Pan, Qinmin

    2013-01-01

    We are presenting a simplified alternative method for dispersive liquid-liquid microextraction (DLLME) by resorting to the use of surfactants as emulsifiers and micro solid-phase extraction (μ-SPE). In this combined procedure, DLLME of hydrophobic components is initially accomplished in a mixed micellar/microemulsion extractant phase that is prepared by rapidly mixing a non-ionic surfactant and 1-octanol in aqueous medium. Then, and in contrast to classic DLLME, the extractant phase is collected by highly hydrophobic polysiloxane-coated core-shell Fe 2 O 3 (at)C magnetic nanoparticles. Hence, the sample components are the target analyte in the DLLME which, in turn, becomes the target analyte of the μ-SPE step. This 2-step approach represents a new and simple DLLME procedure that lacks tedious steps such as centrifugation, thawing, or delicate collection of the extractant phase. As a result, the analytical process is accelerated and the volume of the collected phase does not depend on the volume of the extraction solvent. The method was applied to extract cadmium in the form of its pyrrolidine dithiocarbamate chelate from spiked water samples prior to its determination by FAAS. Detection limits were brought down to the low μg L −1 levels by preconcentrating 10 mL samples with satisfactory recoveries (96.0–108.0 %). (author)

  15. Unified pH values of liquid chromatography mobile phases.

    Science.gov (United States)

    Suu, Agnes; Jalukse, Lauri; Liigand, Jaanus; Kruve, Anneli; Himmel, Daniel; Krossing, Ingo; Rosés, Martí; Leito, Ivo

    2015-03-03

    This work introduces a conceptually new approach of measuring pH of mixed-solvent liquid chromatography (LC) mobile phases. Mobile phase pH is very important in LC, but its correct measurement is not straightforward, and all commonly used approaches have deficiencies. The new approach is based on the recently introduced unified pH (pH(abs)) scale, which enables direct comparison of acidities of solutions made in different solvents based on chemical potential of the proton in the solutions. This work represents the first experimental realization of the pH(abs) concept using differential potentiometric measurement for comparison of the chemical potentials of the proton in different solutions (connected by a salt bridge), together with earlier published reference points for obtaining the pH(abs) values (referenced to the gas phase) or pH(abs)(H₂O) values (referenced to the aqueous solution). The liquid junction potentials were estimated in the framework of Izutsu's three-component method. pH(abs) values for a number of common LC and LC-MS mobile phases have been determined. The pH(abs) scale enables for the first time direct comparison of acidities of any LC mobile phases, with different organic additives, different buffer components, etc. A possible experimental protocol of putting this new approach into chromatographic practice has been envisaged and its applicability tested. It has been demonstrated that the ionization behavior of bases (cationic acids) in the mobile phases can be better predicted by using the pH(abs)(H₂O) values and aqueous pKa values than by using the alternative means of expressing mobile phase acidity. Description of the ionization behavior of acids on the basis of pH(abs)(H₂O) values is possible if the change of their pKa values with solvent composition change is taken into account.

  16. Variation in pH of Model Secondary Organic Aerosol during Liquid-Liquid Phase Separation.

    Science.gov (United States)

    Dallemagne, Magda A; Huang, Xiau Ya; Eddingsaas, Nathan C

    2016-05-12

    The majority of atmospheric aerosols consist of both organic and inorganic components. At intermediate relative humidity (RH), atmospheric aerosol can undergo liquid-liquid phase separation (LLPS) in which the organic and inorganic fractions segregate from each other. We have extended the study of LLPS to the effect that phase separation has on the pH of the overall aerosols and the pH of the individual phases. Using confocal microscopy and pH sensitive dyes, the pH of internally mixed model aerosols consisting of polyethylene glycol 400 and ammonium sulfate as well as the pH of the organic fraction during LLPS have been directly measured. During LLPS, the pH of the organic fraction was observed to increase to 4.2 ± 0.2 from 3.8 ± 0.1 under high RH when the aerosol was internally mixed. In addition, the high spatial resolution of the confocal microscope allowed us to characterize the composition of each of the phases, and we have observed that during LLPS the organic shell still contains large quantities of water and should be characterized as an aqueous organic-rich phase rather than simply an organic phase.

  17. Experimental studies on hydrogen isotopic deuterium from gas to liquid phase by catalytic exchange

    International Nuclear Information System (INIS)

    Luo Yangming; Wang Heyi; Liu Jun; Fu Zhonghua; Wang Changbin; Han Jun; Xia Xiulong; Tang Lei

    2005-01-01

    The experimental studies on hydrogen isotopic deuterium from gas to liquid phase were completed by mixed ratio 1:4 of Pt-SDB hydrophobic catalyst and hydrophilic packing. The influencing factors on number of transfer units (NTU) and transformation efficiencies of deuterium were researched. The results show that preferable NTU can be obtained by choosing suitable operational temperature and flux of exchange gas. The transformation rate increases with increasing liquid flux, but it cannot obviously be improved when liquid flux attains some level. The length of catalytic column has an obvious influence on transformation rate and 90% of transformation rate is obtained by 4 m column length at gas flux with 2 m 3 /h, liquid flux with 1-2 kg/h and 45 degree C. (author)

  18. Zpif's law in the liquid gas phase transition of nuclei

    International Nuclear Information System (INIS)

    Ma, Y.G.

    1999-01-01

    Zpif's law in the field of linguistics is tested in the nuclear disassembly within the framework of isospin dependent lattice gas model. It is found that the average cluster charge (or mass) of rank n in the charge (or mass) list shows exactly inversely to its rank, i.e., there exists Zpif's law, at the phase transition temperature. This novel criterion shall be helpful to search the nuclear liquid gas phase transition experimentally and theoretically. In addition, the finite size scaling of the effective phase transition temperature at which the Zpif's law appears is studied for several systems with different mass and the critical exponents of ν and β are tentatively extracted. (orig.)

  19. Development of the liquid level meters for the PandaX dark matter detector

    International Nuclear Information System (INIS)

    Hu Jie; Gong Haowei; Lin Qing; Ni Kaixuan; Wei Yuehuan; Xiao Mengjiao; Xiao Xiang; Zhao Li; Tan Andi

    2014-01-01

    The two-phase xenon detector is at the frontier of dark matter direct search. This kind of detector uses liquid xenon as the sensitive target and is operated in two-phase (liquid/gas) mode, where the liquid level needs to be monitored and controlled in sub-millimeter precision. In this paper, we present a detailed design and study of two kinds of level meters for the PandaX dark matter detector. The long level meter is used to monitor the overall liquid level while short level meters are used to monitor the inclination of the detector. These level meters are cylindrical capacitors that are custom-made from two concentric metal tubes. Their capacitance values are read out by a universal transducer interface chip and are recorded by the PandaX slow control system. We present the developments that lead to level meters with long-term stability and sub-millimeter precision. Fluctuations (standard deviations) of less than 0.02 mm for the short level meters and less than 0.2 mm for the long level meter were achieved during a few days of test operation. (authors)

  20. Liquid phase microextraction of pesticides: a review on current methods

    International Nuclear Information System (INIS)

    Farajzadeh, Mir Ali; Sorouraddin, Saeed Mohammad; Mogaddam, Mohammad Reza Afshar

    2014-01-01

    Liquid phase microextraction (LPME) enables analytes to be extracted with a few microliters of an organic solvent. LPME is a technique for sample preparation that is extremely simple, affordable and virtually a solvent-free. It can provide a high degree of selectivity and enrichment by eliminating carry-over between single runs. A variety of solvents are known for the extraction of the various analytes. These features have led to the development of techniques such as single drop microextraction, hollow fiber LPME, dispersive liquid-liquid microextraction, and others. LPME techniques have been applied to the analysis of pharmaceuticals, food, beverages, and pesticides. This review covers the history of LPME methods, and then gives a comprehensive collection of their application to the preconcentration and determination of pesticides in various matrices. Specific sections cover (a) sample treatment techniques in general, (b) single-drop microextraction, (c) extraction based on the use of ionic liquids, (d) solidified floating organic drop microextraction, and various other techniques. (author)

  1. Drug Release and Skin Permeation from Lipid Liquid Crystalline Phases

    Science.gov (United States)

    Costa-Balogh, F. O.; Sparr, E.; Sousa, J. J. S.; Pais, A. A. C. C.

    We have studied drug release and skin permeation from several different liquid crystalline lipid formulations that may be used to control the respective release rates. We have studied the release and permeation through human skin of a water-soluble and amphiphilic drug, propranolol hydrochloride, from several formulations prepared with monoolein and phytantriol as permeation enhancers and controlled release excipients. Diolein and cineol were added to selected formulations. We observed that viscosity decreases with drug load, wich is compatible with the occurrence of phase changes. Diolein stabilizes the bicontinuous cubic phases leading to an increase in viscosity and sustained release of the drug. The slowest release was found for the cubic phases with higher viscosity. Studies on skin permeation showed that these latter formulations also presented lower permeability than the less viscous monoolein lamellar phases. Formulations containing cineol originated higher permeability with higher enhancement ratios. Thus, the various formulations are adapted to different circumstances and delivery routes. While a slow release is usually desired for drug sustained delivery, the transdermal route may require a faster release. Lamellar phases, which are less viscous, are more adapted to transdermal applications. Thus, systems involving lamellar phases of monoolein and cineol are good candidates to be used as skin permeation enhancers for propranolol hydrochloride.

  2. Liquid crystal phase behaviour of attractive disc-like particles.

    Science.gov (United States)

    Wu, Liang; Jackson, George; Müller, Erich A

    2013-08-08

    We employ a generalized van der Waals-Onsager perturbation theory to construct a free energy functional capable of describing the thermodynamic properties and orientational order of the isotropic and nematic phases of attractive disc particles. The model mesogen is a hard (purely repulsive) cylindrical disc particle decorated with an anisotropic square-well attractive potential placed at the centre of mass. Even for isotropic attractive interactions, the resulting overall inter-particle potential is anisotropic, due to the orientation-dependent excluded volume of the underlying hard core. An algebraic equation of state for attractive disc particles is developed by adopting the Onsager trial function to characterize the orientational order in the nematic phase. The theory is then used to represent the fluid-phase behaviour (vapour-liquid, isotropic-nematic, and nematic-nematic) of the oblate attractive particles for varying values of the molecular aspect ratio and parameters of the attractive potential. When compared to the phase diagram of their athermal analogues, it is seen that the addition of an attractive interaction facilitates the formation of orientationally-ordered phases. Most interestingly, for certain aspect ratios, a coexistence between two anisotropic nematic phases is exhibited by the attractive disc-like fluids.

  3. Operating safety requirements for the intermediate level liquid waste system

    International Nuclear Information System (INIS)

    1980-07-01

    The operation of the Intermediate Level Liquid Waste (ILW) System, which is described in the Final Safety Analysis, consists of two types of operations, namely: (1) the operation of a tank farm which involves the storage and transportation through pipelines of various radioactive liquids; and (2) concentration of the radioactive liquids by evaporation including rejection of the decontaminated condensate to the Waste Treatment Plant and retention of the concentrate. The following safety requirements in regard to these operations are presented: safety limits and limiting control settings; limiting conditions for operation; and surveillance requirements. Staffing requirements, reporting requirements, and steps to be taken in the event of an abnormal occurrence are also described

  4. Highly tilted liquid crystalline materials possessing a direct phase transition from antiferroelectric to isotropic phase

    Energy Technology Data Exchange (ETDEWEB)

    Milewska, K.; Drzewiński, W. [Institute of Chemistry, Military University of Technology, 00-908 Warsaw (Poland); Czerwiński, M., E-mail: mczerwinski@wat.edu.pl [Institute of Chemistry, Military University of Technology, 00-908 Warsaw (Poland); Dąbrowski, R. [Institute of Chemistry, Military University of Technology, 00-908 Warsaw (Poland); Piecek, W. [Institute of Applied Physics, Military University of Technology, 00-908 Warsaw (Poland)

    2016-03-01

    Pure compounds and multicomponent mixtures with a broad temperature range of high tilted liquid crystalline antiferroelectric phase and a direct phase transition from antiferroelectric to isotropic phase, were obtained. X-ray diffraction analysis confirms these kinds of materials form a high tilted anticlinic phase, with a fixed layer spacing and very weak dependency upon temperature, after the transition from the isotropic phase. Due to this, not only pure orthoconic antiferroelectric liquid crystals but also those with a moderate tilt should generate a good dark state. Furthermore, due to the increased potential for forming anticlinic forces, such materials could minimize a commonly observed asymmetry of a rise and fall switching times at a surface stabilized geometry. - Highlights: • The new class of liquid crystalline materials with the direct SmC{sub A}*. • Iso phase transition were obtained. • Materials possess the layer spacing fixed and very weak dependent upon temperature. • Smectic layers without shrinkage are observed. • A good dark state can be generate in SSAFLC.

  5. Void fraction prediction in two-phase flows independent of the liquid phase density changes

    International Nuclear Information System (INIS)

    Nazemi, E.; Feghhi, S.A.H.; Roshani, G.H.

    2014-01-01

    Gamma-ray densitometry is a frequently used non-invasive method to determine void fraction in two-phase gas liquid pipe flows. Performance of flow meters using gamma-ray attenuation depends strongly on the fluid properties. Variations of the fluid properties such as density in situations where temperature and pressure fluctuate would cause significant errors in determination of the void fraction in two-phase flows. A conventional solution overcoming such an obstacle is periodical recalibration which is a difficult task. This paper presents a method based on dual modality densitometry using Artificial Neural Network (ANN), which offers the advantage of measuring the void fraction independent of the liquid phase changes. An experimental setup was implemented to generate the required input data for training the network. ANNs were trained on the registered counts of the transmission and scattering detectors in different liquid phase densities and void fractions. Void fractions were predicted by ANNs with mean relative error of less than 0.45% in density variations range of 0.735 up to 0.98 gcm −3 . Applying this method would improve the performance of two-phase flow meters and eliminates the necessity of periodical recalibration. - Highlights: • Void fraction was predicted independent of density changes. • Recorded counts of detectors/void fraction were used as inputs/output of ANN. • ANN eliminated necessity of recalibration in changeable density of two-phase flows

  6. Solution processing of polymer semiconductor: Insulator blends-Tailored optical properties through liquid-liquid phase separation control

    KAUST Repository

    Hellmann, Christoph

    2014-12-17

    © 2014 Wiley Periodicals, Inc. It has been demonstrated that the 0-0 absorption transition of poly(3-hexylthiophene) (P3HT) in blends with poly(ethylene oxide) (PEO) could be rationally tuned through the control of the liquid-liquid phase separation process during solution deposition. Pronounced J-like aggregation behavior, characteristic for systems of a low exciton band width, was found for blends where the most pronounced liquid-liquid phase separation occurred in solution, leading to domains of P3HT and PEO of high phase purity. Since liquid-liquid phase separation could be readily manipulated either by the solution temperature, solute concentration, or deposition temperature, to name a few parameters, our findings promise the design from the out-set of semiconductor:insulator architectures of pre-defined properties by manipulation of the interaction parameter between the solutes as well as the respective solute:solvent system using classical polymer science principles.

  7. Solution processing of polymer semiconductor: Insulator blends-Tailored optical properties through liquid-liquid phase separation control

    KAUST Repository

    Hellmann, Christoph; Treat, Neil D.; Scaccabarozzi, Alberto D.; Razzell Hollis, Joseph; Fleischli, Franziska D.; Bannock, James H.; de Mello, John; Michels, Jasper J.; Kim, Ji-Seon; Stingelin, Natalie

    2014-01-01

    © 2014 Wiley Periodicals, Inc. It has been demonstrated that the 0-0 absorption transition of poly(3-hexylthiophene) (P3HT) in blends with poly(ethylene oxide) (PEO) could be rationally tuned through the control of the liquid-liquid phase separation process during solution deposition. Pronounced J-like aggregation behavior, characteristic for systems of a low exciton band width, was found for blends where the most pronounced liquid-liquid phase separation occurred in solution, leading to domains of P3HT and PEO of high phase purity. Since liquid-liquid phase separation could be readily manipulated either by the solution temperature, solute concentration, or deposition temperature, to name a few parameters, our findings promise the design from the out-set of semiconductor:insulator architectures of pre-defined properties by manipulation of the interaction parameter between the solutes as well as the respective solute:solvent system using classical polymer science principles.

  8. Three-phase flow analysis of dense nonaqueous phase liquid infiltration in horizontally layered porous media

    NARCIS (Netherlands)

    Wipfler, E.L.; Dijke, van M.I.J.; Zee, van der S.E.A.T.M.

    2004-01-01

    We considered dense nonaqueous phase liquid (DNAPL) infiltration into a water-unsaturated porous medium that consists of two horizontal layers, of which the top layer has a lower intrinsic permeability than the bottom layer. DNAPL is the intermediate-wetting fluid with respect to the wetting water

  9. Determination of Bisphenol A and Bisphenol AF in Vinegar samples by two-component mixed ionic liquid dispersive liquid-phase microextraction coupled with high performance liquid chromatography

    International Nuclear Information System (INIS)

    Tai, Z.; Liu, M.; Hu, X.; Yang, Y.

    2014-01-01

    This paper describes a sensitive and simple method for the determination of bisphenol A (BPA) and bisphenol AF (BPAF) in vinegar samples using two-component mixed ionic liquid dispersive liquid-phase microextraction coupled with high performance liquid chromatography. In this work, BPA and BPAF were selected as the model analytes, and two-component mixed ionic liquid included 1-butyl-3-methylimidazolium hexafluorophosphate ((C4Mim)PF6) and 1-hexyl-3-methyl-imidazolium hexafluorophosphate ((C6Mim)PF6) was used as the extraction solvent for the first time here. Parameters that affect the extraction efficiency were investigated. Under the optimum conditions, good linear relationships were discovered in the range of 1.0-100 micro g/L for BPA and 2.0-150 micro g/L for BPAF, respectively. Detection limits of proposed method based on the signal-to-noise ratio (S/N=3) were in the range of 0.15-0.38 micro g/L. The efficiencies of proposed method have also been demonstrated with spiked real vinegar samples. The result show this method/ procedure to be a more efficient approach for the determination of BPA and BPAF in real vinegar, presenting average recovery rate of 89.3-112 % and precision values of 0.9-13.5% (RSDs, n = 6). In comparison with traditional solid phase extraction procedures this method results in lower solvent consumption, low pollution levels, and faster sample preparation. (author)

  10. Simulation of bulk phases formed by polyphilic liquid crystal dendrimers

    Directory of Open Access Journals (Sweden)

    J.M. Ilnytskyi

    2010-01-01

    Full Text Available A coarse-grained simulation model for a third generation liquid crystalline dendrimer (LCDr is presented. It allows, for the first time, for a successful molecular simulation study of a relation between the shape of a polyphilic macromolecular mesogen and the symmetry of a macroscopic phase. The model dendrimer consists of a soft central sphere and 32 grafted chains each terminated by a mesogen group. The mesogenic pair interactions are modelled by the recently proposed soft core spherocylinder model of Lintuvuori and Wilson [J. Chem. Phys, 128, 044906, (2008]. Coarse-grained (CG molecular dynamics (MD simulations are performed on a melt of 100 molecules in the anisotropic-isobaric ensemble. The model LCDr shows conformational bistability, with both rod-like and disc-like conformations stable at lower temperatures. Each conformation can be induced by an external aligning field of appropriate symmetry that acts on the mesogens (uniaxial for rod-like and planar for disc-like, leading to formation of a monodomain smectic A (SmA or a columnar (Col phase, respectively. Both phases are stable for approximately the same temperature range and both exhibit a sharp transition to an isotropic cubic-like phase upon heating. We observe a very strong coupling between the conformation of the LCDr and the symmetry of a bulk phase, as suggested previously by theory. The study reveals rich potential in terms of the application of this form of CG modelling to the study of molecular self-assembly of liquid crystalline macromolecules.

  11. Proposal of new bonding technique 'Instantaneous Liquid Phase (ILP) Bonding'

    International Nuclear Information System (INIS)

    Zhang, Yue-Chang; Nakagawa, Hiroji; Matsuda, Fukuhisa.

    1987-01-01

    A new bonding technique named ''Instantaneous Liquid Phase (ILP) bonding'' suitable mainly for welding dissimilar materials was proposed by which instantaneous melting of one or two of the faying surfaces is utilized. The processes of ILP bonding are mainly consisted of three stages, namely the first stage forming thin liquid layer by rapid heating, the second stage joining both specimens by thin liquid layer, and the third stage cooling the specimens rapidly to avoid the formation of brittle layer. The welding temperatures of the specimens to be welded in ILP bonding are generally differentiated from each other. ILP bonding was applied for a variety of combinations of dissimilar materials of aluminum, aluminum alloys, titanium, titanium alloy, carbon steel, austenitic stainless steel, copper and tungsten, and for similar materials of stainless steel and nickel-base alloy. There were no microvoids in these welding joints, and the formation of brittle layer at the bonding interface was suppressed. The welded joints of Al + Ti, Cu + carbon steel and Cu + austenitic stainless steel showed the fracture in base metal having lower tensile strength. Further, the welded joints of Al + carbon steel, Al alloy + Ti, Al alloy + carbon steel or + austenitic stainless steel, Ti + carbon steel or + austenitic stainless steel showed better tensile properties in the comparison with diffusion welding. Furthermore, ILP bonding was available for welding same materials susceptible to hot cracking. Because of the existence of liquid layer, the welding pressure required was extremely low, and preparation of faying surface by simple tooling or polishing by no.80 emery paper was enough. The change in specimen length before and after welding was relatively little, only depending on the thickness of liquid layer. The welding time was very short, and thus high welding efficiency was obtained. (author)

  12. The shape of the melting curve and phase transitions in the liquid state

    International Nuclear Information System (INIS)

    Yahel, Eyal

    2014-01-01

    The phase diagram of elemental liquids has been found to be surprisingly rich, including variations in the melting curve and transitions in the liquid phase. The effect of these transitions on the shape of the melting curve is reviewed and analyzed. First-order phase transitions intersecting the melting curve imply piecewise continuous melting curves, with solid-solid transitions generating upward kinks or minima and liquid-liquid transitions generating downward kinks or maxima

  13. Environmental information volume: Liquid Phase Methanol (LPMEOH{trademark}) project

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-05-01

    The purpose of this project is to demonstrate the commercial viability of the Liquid Phase Methanol Process using coal-derived synthesis gas, a mixture of hydrogen and carbon monoxide. This report describes the proposed actions, alternative to the proposed action, the existing environment at the coal gasification plant at Kingsport, Tennessee, environmental impacts, regulatory requirements, offsite fuel testing, and DME addition to methanol production. Appendices include the air permit application, solid waste permits, water permit, existing air permits, agency correspondence, and Eastman and Air Products literature.

  14. Environmental information volume: Liquid Phase Methanol (LPMEOH trademark) project

    International Nuclear Information System (INIS)

    1996-05-01

    The purpose of this project is to demonstrate the commercial viability of the Liquid Phase Methanol Process using coal-derived synthesis gas, a mixture of hydrogen and carbon monoxide. This report describes the proposed actions, alternative to the proposed action, the existing environment at the coal gasification plant at Kingsport, Tennessee, environmental impacts, regulatory requirements, offsite fuel testing, and DME addition to methanol production. Appendices include the air permit application, solid waste permits, water permit, existing air permits, agency correspondence, and Eastman and Air Products literature

  15. Radiolysis of hydrocarbons in liquid phase (Modern state of problem)

    International Nuclear Information System (INIS)

    Saraeva, V.V.

    1986-01-01

    Problems of ionizing radiation effect on hydrocarbons and hydrocarbon systems in a liquid phase are considered. Modern representations on the mechanism of hydrocarbon radiolysis are presented. Electron moderation and ion-electron pair formation, behaviour of charged particles, excited states, radical formation and their reactions are discussed. Behaviour of certain hydrocarbon classes: alkanes, cyclic hydrocarbons, olefines, aromatic hydrocarbons as well as different hydrocarbon mixtures is considered in detail. Radiation-chemical changes in organic coolants and ways of increasing radiation resistance are considered. Polyphenyl compounds are noted to be most perspective here

  16. A review of liquid-phase catalytic hydrodechlorination

    Directory of Open Access Journals (Sweden)

    Alba Nelly Ardila Arias

    2007-09-01

    Full Text Available This survey was aimed at introducing the effect of light organochlorinated compound emissions on the envi-ronment, particularly on water, air, soil, biota and human beings. The characteristics and advantages of liquid phase catalytic hydrodechlorination as a technology for degrading these chlorinated compounds is also outlined and the main catalysts used in the hydrodechlorination process are described. Special emphasis is placed on palladium catalysts, their activity, the nature of active species and deactivation. The effect of several parameters is introduced, such as HCl, solvent, base addition and type of reducing agent used. The main results of kinetic studies, reactors used and the most important survey conclusions are presented.

  17. Surface passivation of liquid phase epitaxial GaAs

    International Nuclear Information System (INIS)

    Alexiev, D.; Butcher, K.S.A.; Mo, L.; Edmondson, M.

    1995-10-01

    Passivation of the liquid phase epitaxial GaAs surface was attempted using aqueous P 2 S 5 -NH 4 OH, (NH 4 ) 2 S x and plasma nitrogenation and hydrogenation. Results indicate that plasma nitrogenation with pretreatment of plasma hydrogenation produced consistent reduction in reverse leakage current at room temperature for all p and n type Schottky diodes. Some diodes showed an order of magnitude improvement in current density. (NH 4 ) 2 S x passivation also results in improved I-V characteristics, though the long term stability of this passivation is questionable. 26 refs., 6 figs

  18. Liquid phase epitaxy of gallium arsenide - a review

    International Nuclear Information System (INIS)

    Alexiev, D.; Edmondson, M.; Butcher, K.S.A.; Tansley, T.

    1992-07-01

    Liquid phase epitaxy of gallium arsenide has been investigated intensively from the late 1960's to the present and has now a special place in the manufacture of wide band, compound semiconductor radiation detectors. Although this particular process appears to have gained prominence in the last three decades, the authors point out that its origins reach back to 1836 when Frankenheim made his first observations. A brief review is presented from a semiconductor applications point of view on how this subject developed. 70 refs., 5 figs

  19. Utilization of a liquid crystal spatial light modulator in a gray scale detour phase method for Fourier holograms.

    Science.gov (United States)

    Makey, Ghaith; El-Daher, Moustafa Sayem; Al-Shufi, Kanj

    2012-11-10

    This paper introduces a new modification for the well-known binary detour phase method, which is largely used to represent Fourier holograms; the modification utilizes gray scale level control provided by a liquid crystal spatial light modulator to improve the traditional binary detour phase. Results are shown by both simulation and experiment.

  20. Treatment of low- and intermediate-level liquid radioactive wastes

    International Nuclear Information System (INIS)

    1984-01-01

    This report aims at giving the reader details of the experience gained in the treatment of both low- and intermediate-level radioactive liquid wastes. The treatment comprises those operations to remove radioactivity from the wastes and those that change only its chemical composition, so as to permit its discharge. Considerable experience has been accumulated in the satisfactory treatment of such wastes. Although there are no universally accepted definitions for low- and intermediate-level liquid radioactive wastes, the IAEA classification (see section 3.2) is used in this report. The two categories differ from one another in the fact that for low-level liquids the actual radiation does not require shielding during normal handling of the wastes. Liquid wastes which are not considered in this report are those from mining and milling operations and the high-level liquid wastes resulting from fuel reprocessing. These are referred to in separate IAEA reports. Likewise, wastes from decommissioning operations are not within the scope of this report. Apart from the description of existing methods and facilities, this report is intended to provide advice to the reader for the selection of appropriate solutions to waste management problems. In addition, new and promising techniques which are either being investigated or being considered for the future are discussed

  1. Liquid-liquid phase separation in aerosol particles: Imaging at the Nanometer Scale

    Energy Technology Data Exchange (ETDEWEB)

    O' Brien, Rachel; Wang, Bingbing; Kelly, Stephen T.; Lundt, Nils; You, Yuan; Bertram, Allan K.; Leone, Stephen R.; Laskin, Alexander; Gilles, Mary K.

    2015-04-21

    Atmospheric aerosols can undergo phase transitions including liquid-liquid phase separation (LLPS) while responding to changes in the ambient relative humidity (RH). Here, we report results of chemical imaging experiments using environmental scanning electron microscopy (ESEM) and scanning transmission x-ray microscopy (STXM) to investigate the LLPS of micron sized particles undergoing a full hydration-dehydration cycle. Internally mixed particles composed of ammonium sulfate (AS) and either: limonene secondary organic carbon (LSOC), a, 4-dihydroxy-3-methoxybenzeneaceticacid (HMMA), or polyethylene glycol (PEG-400) were studied. Events of LLPS with apparent core-shell particle morphology were observed for all samples with both techniques. Chemical imaging with STXM showed that both LSOC/AS and HMMA/AS particles were never homogeneously mixed for all measured RH’s above the deliquescence point and that the majority of the organic component was located in the shell. The shell composition was estimated as 65:35 organic: inorganic in LSOC/AS and as 50:50 organic: inorganic for HMMA/AS. PEG-400/AS particles showed fully homogeneous mixtures at high RH and phase separated below 89-92% RH with an estimated 50:50% organic to inorganic mix in the shell. These two chemical imaging techniques are well suited for in-situ analysis of the hygroscopic behavior, phase separation, and surface composition of collected ambient aerosol particles.

  2. About the Shape of the Melting Line as a Possible Precursor of a Liquid-Liquid Phase Transition

    Science.gov (United States)

    Imre, Attila R.; Rzoska, Sylwester J.

    Several simple, non-mesogenic liquids can exists in two or more different liquid forms. When the liquid-liquid line, separating two liquid forms, meets the melting line, one can expect some kind of break on the melting line, caused by the different freezing/melting behaviour of the two liquid forms. Unfortunately recently several researchers are using this vein of thinking in reverse; seeing some irregularity on the melting line, they will expect a break and the appearance of a liquid-liquid line. In this short paper, we are going to show, that in the case of the high-pressure nitrogen studied recently by Mukherjee and Boehler, the high-pressure data can be easily described by a smooth, break-free function, the modified Simon-Glatzel equation. In this way, the break, suggested by them and consequently the suggested appearance of a new liquid phase of the nitrogen might be artefacts.

  3. Tube Radial Distribution Flow Separation in a Microchannel Using an Ionic Liquid Aqueous Two-Phase System Based on Phase Separation Multi-Phase Flow.

    Science.gov (United States)

    Nagatani, Kosuke; Shihata, Yoshinori; Matsushita, Takahiro; Tsukagoshi, Kazuhiko

    2016-01-01

    Ionic liquid aqueous two-phase systems were delivered into a capillary tube to achieve tube radial distribution flow (TRDF) or annular flow in a microspace. The phase diagram, viscosity of the phases, and TRDF image of the 1-butyl-3-methylimidazolium chloride and NaOH system were examined. The TRDF was formed with inner ionic liquid-rich and outer ionic liquid-poor phases in the capillary tube. The phase configuration was explained using the viscous dissipation principle. We also examined the distribution of rhodamine B in a three-branched microchannel on a microchip with ionic liquid aqueous two-phase systems for the first time.

  4. Treatment of ORNL liquid low-level waste

    International Nuclear Information System (INIS)

    Berry, J.B.; Brown, C.H. Jr.; Fowler, V.L.; Robinson, S.M.

    1988-01-01

    Discontinuation of the hydrofracture disposal method at Oak Ridge National Laboratory (ORNL) has caused intensive efforts to reduce liquid waste generation. Improving the treatment of slightly radioactive liquid waste, called process waste, has reduced the volume of the resulting contaminated liquid radioactive waste effluent by 66%. Proposed processing improvements could eliminate the contaminated liquid effluent and reduce solid low-level waste by an additional one-third. The improved process meets stringent discharge limits for radionuclides. Discharge limits for radionuclides are expected to be enforced at the outfall of the treatment plant to a creek; currently, limits are enforced at the reservation boundary. Plant discharge is monitored according to the National Pollutant Discharge Elimination System (NPDES) permit for ORNL. 1 ref., 4 figs., 2 tabs

  5. Volume phase transitions of cholesteric liquid crystalline gels.

    Science.gov (United States)

    Matsuyama, Akihiko

    2015-05-07

    We present a mean field theory to describe anisotropic deformations of a cholesteric elastomer without solvent molecules and a cholesteric liquid crystalline gel immersed in isotropic solvents at a thermal equilibrium state. Based on the neoclassical rubber theory of nematic elastomers, we derive an elastic energy and a twist distortion energy, which are important to determine the shape of a cholesteric elastomer (or gel). We demonstrate that when the elastic energy dominates in the free energy, the cholesteric elastomer causes a spontaneous compression in the pitch axis and elongates along the director on the plane perpendicular to the pitch axis. Our theory can qualitatively describe the experimental results of a cholesteric elastomer. We also predict the first-order volume phase transitions and anisotropic deformations of a gel at the cholesteric-isotropic phase transition temperature. Depending on a chirality of a gel, we find a prolate or oblate shape of cholesteric gels.

  6. Volume phase transitions of cholesteric liquid crystalline gels

    Energy Technology Data Exchange (ETDEWEB)

    Matsuyama, Akihiko, E-mail: matuyama@bio.kyutech.ac.jp [Department of Bioscience and Bioinformatics, Faculty of Computer Science and Systems Engineering, Kyushu Institute of Technology, Kawazu 680-4, Iizuka, Fukuoka 820-8502 (Japan)

    2015-05-07

    We present a mean field theory to describe anisotropic deformations of a cholesteric elastomer without solvent molecules and a cholesteric liquid crystalline gel immersed in isotropic solvents at a thermal equilibrium state. Based on the neoclassical rubber theory of nematic elastomers, we derive an elastic energy and a twist distortion energy, which are important to determine the shape of a cholesteric elastomer (or gel). We demonstrate that when the elastic energy dominates in the free energy, the cholesteric elastomer causes a spontaneous compression in the pitch axis and elongates along the director on the plane perpendicular to the pitch axis. Our theory can qualitatively describe the experimental results of a cholesteric elastomer. We also predict the first-order volume phase transitions and anisotropic deformations of a gel at the cholesteric-isotropic phase transition temperature. Depending on a chirality of a gel, we find a prolate or oblate shape of cholesteric gels.

  7. Water detritiation: better catalysts for liquid phase catalytic exchange

    International Nuclear Information System (INIS)

    Braet, J.

    2005-01-01

    Fusion reactors are our hope for a clean nuclear energy. But as they shall handle huge amounts of tritium, 1.5 10 19 Bq GWth -1 a -1 or about 50 000 times more tritium than light water fission reactors, they need detritiation. Most tritium losses can be trapped as or can easily be transformed into tritiated water. Water detritiation is preferably based on the multiplication of the large equilibrium isotope effect during the exchange reaction of tritium between hydrogen gas and liquid water in a counter current trickle bed reactor. Such LPCE (Liquid Phase Catalytic Exchange) requires an efficient hydrophobic catalyst. SCK-CEN invented and developed such a catalyst in the past. In combination with an appropriate packing, different batches of this catalyst performed very well during years of extensive testing, allowing to develop the ELEX process for water detritiation at inland reprocessing plants. The main objectives of this study were to reproduce and possibly improve the SCK-CEN catalyst for tritium exchange between hydrogen and liquid water; and to demonstrate the high overall exchange rate and thus high detritiation factors that can be realized with it in a small and simple LPCE column under typical but conservative operating conditions

  8. Continuous liquid level monitoring sensor system using fiber Bragg grating

    Science.gov (United States)

    Sengupta, Dipankar; Kishore, Putha

    2014-01-01

    The design and packaging of simple, small, and low cost sensor heads, used for continuous liquid level measurement using uniformly thinned (etched) optical fiber Bragg grating (FBG) are proposed. The sensor system consists of only an FBG and a simple detection system. The sensitivity of sensor is found to be 23 pm/cm of water column pressure. A linear optical fiber edge filter is designed and developed for the conversion of Bragg wavelength shift to its equivalent intensity. The result shows that relative power measured by a photo detector is linearly proportional to the liquid level. The obtained sensitivity of the sensor is nearly -15 mV/cm.

  9. The Utilization of Triton X-100 for Enhanced Two-Dimensional Liquid-Phase Proteomics

    OpenAIRE

    Kim, Mina; Lee, Sang-Hee; Min, Jiho; Kobayashi, Fumihisa; Um, Hyun-Ju; Kim, Yang-Hoon

    2011-01-01

    One of the main challenges in proteomics lies in obtaining a high level of reproducible fractionation of the protein samples. Automated two-dimensional liquid phase fractionation (PF2D) system manufactured by Beckman Coulter provides a process well suited for proteome studies. However, the protein recovery efficiency of such system is low when a protocol recommended by the manufacturer is used for metaproteome profiling of environmental sample. In search of an alternative method that can over...

  10. Application of Ionic Liquids in High Performance Reversed-Phase Chromatography

    Directory of Open Access Journals (Sweden)

    Wentao Bi

    2009-06-01

    Full Text Available Ionic liquids, considered “green” chemicals, are widely used in many areas of analytical chemistry due to their unique properties. Recently, ionic liquids have been used as a kind of novel additive in separation and combined with silica to synthesize new stationary phase as separation media. This review will focus on the properties and mechanisms of ionic liquids and their potential applications as mobile phase modifier and surface-bonded stationary phase in reversed-phase high performance liquid chromatography (RP-HPLC. Ionic liquids demonstrate advantages and potential in chromatographic field.

  11. 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.

  12. Comparing two tetraalkylammonium ionic liquids. II. Phase transitions

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Thamires A.; Paschoal, Vitor H.; Faria, Luiz F. O.; Ribeiro, Mauro C. C., E-mail: mccribei@iq.usp.br [Laboratório de Espectroscopia Molecular, Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, CP 26077, CEP 05513-970 São Paulo, SP (Brazil); Ferreira, Fabio F.; Costa, Fanny N. [Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Santo André, SP (Brazil); Giles, Carlos [Depto. de Física da Matéria Condensada, Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, 13083-859 Campinas, SP (Brazil)

    2016-06-14

    Phase transitions of the ionic liquids n-butyl-trimethylammonium bis(trifluoromethanesulfonyl)imide, [N{sub 1114}][NTf{sub 2}], and methyl-tributylammonium bis(trifluoromethanesulfonyl)imide, [N{sub 1444}][NTf{sub 2}], were investigated by differential scanning calorimetry (DSC), X-ray diffraction (XRD) measurements, and Raman spectroscopy. XRD and Raman spectra were obtained as a function of temperature at atmospheric pressure, and also under high pressure at room temperature using a diamond anvil cell (DAC). [N{sub 1444}][NTf{sub 2}] experiences glass transition at low temperature, whereas [N{sub 1114}][NTf{sub 2}] crystallizes or not depending on the cooling rate. Both the ionic liquids exhibit glass transition under high pressure. XRD and low-frequency Raman spectra provide a consistent physical picture of structural ordering-disordering accompanying the thermal events of crystallization, glass transition, cold crystallization, pre-melting, and melting. Raman spectra in the high-frequency range of some specific cation and anion normal modes reveal conformational changes of the molecular structures along phase transitions.

  13. Biodegradation of naphthalene from nonaqueous-phase liquids

    International Nuclear Information System (INIS)

    Ghoshal, S.; Luthy, R.G.; Ramaswami, A.

    1995-01-01

    Dissolution of polycyclic aromatic hydrocarbons (PAHs) from a non-aqueous-phase liquid (NAPL) to the aqueous phase renders these compounds bioavailable to microorganisms. Subsequent biodegradation of organic phase PAH then results in a depletion of PAH from the NAPL. This study focuses on identifying the rate-controlling processes affecting naphthalene biomineralization from a complex multicomponent NAPL, coal tar, and a simple two-component NAPL. A simplified dissolution degradation model is presented to identify quantitative criteria to assess whether mass transfer or biokinetic limitations control the overall rate of biotransformation of PAH compounds. Results show that the rate of mass transfer may control the overall rate of biotransformation in certain systems. Mass transfer does not limit biodegradation in slurry systems when coal tar is distributed in the micropores of a large number of small microporous silica particles. The end points of naphthalene degradation from the NAPLs have been evaluated, and results suggest that depletion of a significant mass of naphthalene from the NAPL phase is possible

  14. Modelling and numerical simulation of liquid-vapor phase transitions

    International Nuclear Information System (INIS)

    Caro, F.

    2004-11-01

    This work deals with the modelling and numerical simulation of liquid-vapor phase transition phenomena. The study is divided into two part: first we investigate phase transition phenomena with a Van Der Waals equation of state (non monotonic equation of state), then we adopt an alternative approach with two equations of state. In the first part, we study the classical viscous criteria for selecting weak solutions of the system used when the equation of state is non monotonic. Those criteria do not select physical solutions and therefore we focus a more recent criterion: the visco-capillary criterion. We use this criterion to exactly solve the Riemann problem (which imposes solving an algebraic scalar non linear equation). Unfortunately, this step is quite costly in term of CPU which prevent from using this method as a ground for building Godunov solvers. That is why we propose an alternative approach two equations of state. Using the least action principle, we propose a phase changing two-phase flow model which is based on the second thermodynamic principle. We shall then describe two equilibrium submodels issued from the relaxations processes when instantaneous equilibrium is assumed. Despite the weak hyperbolicity of the last sub-model, we propose stable numerical schemes based on a two-step strategy involving a convective step followed by a relaxation step. We show the ability of the system to simulate vapor bubbles nucleation. (author)

  15. Enhanced Densification of PM Steels by Liquid Phase Sintering with Boron-Containing Master Alloy

    Science.gov (United States)

    Vattur Sundaram, Maheswaran; Surreddi, Kumar Babu; Hryha, Eduard; Veiga, Angela; Berg, Sigurd; Castro, Fransisco; Nyborg, Lars

    2018-01-01

    Reaching high density in PM steels is important for high-performance applications. In this study, liquid phase sintering of PM steels by adding gas-atomized Ni-Mn-B master alloy was investigated for enhancing the density levels of Fe- and Mo- prealloyed steel powder compacts. The results indicated that liquid formation occurs in two stages, beginning with the master alloy melting (LP-1) below and eutectic phase formation (LP-2) above 1373 K (1100 °C). Mo and C addition revealed a significant influence on the LP-2 temperatures and hence on the final densification behavior and mechanical properties. Microstructural embrittlement occurs with the formation of continuous boride networks along the grain boundaries, and its severity increases with carbon addition, especially for 2.5 wt pct of master alloy content. Sintering behavior, along with liquid generation, microstructural characteristics, and mechanical testing revealed that the reduced master alloy content from 2.5 to 1.5 wt pct (reaching overall boron content from 0.2 to 0.12 wt pct) was necessary for obtaining good ductility with better mechanical properties. Sintering with Ni-Mn-B master alloy enables the sintering activation by liquid phase formation in two stages to attain high density in PM steels suitable for high-performance applications.

  16. Predicting glass-to-glass and liquid-to-liquid phase transitions in supercooled water using classical nucleation theory

    Science.gov (United States)

    Tournier, Robert F.

    2018-01-01

    Glass-to-glass and liquid-to-liquid phase transitions are observed in bulk and confined water, with or without applied pressure. They result from the competition of two liquid phases separated by an enthalpy difference depending on temperature. The classical nucleation equation of these phases is completed by this quantity existing at all temperatures, a pressure contribution, and an enthalpy excess. This equation leads to two homogeneous nucleation temperatures in each liquid phase; the first one (Tn- below Tm) being the formation temperature of an "ordered" liquid phase and the second one corresponding to the overheating temperature (Tn+ above Tm). Thermodynamic properties, double glass transition temperatures, sharp enthalpy and volume changes are predicted in agreement with experimental results. The first-order transition line at TLL = 0.833 × Tm between fragile and strong liquids joins two critical points. Glass phase above Tg becomes "ordered" liquid phase disappearing at TLL at low pressure and at Tn+ = 1.302 × Tm at high pressure.

  17. Gradient augmented level set method for phase change simulations

    Science.gov (United States)

    Anumolu, Lakshman; Trujillo, Mario F.

    2018-01-01

    A numerical method for the simulation of two-phase flow with phase change based on the Gradient-Augmented-Level-set (GALS) strategy is presented. Sharp capturing of the vaporization process is enabled by: i) identification of the vapor-liquid interface, Γ (t), at the subgrid level, ii) discontinuous treatment of thermal physical properties (except for μ), and iii) enforcement of mass, momentum, and energy jump conditions, where the gradients of the dependent variables are obtained at Γ (t) and are consistent with their analytical expression, i.e. no local averaging is applied. Treatment of the jump in velocity and pressure at Γ (t) is achieved using the Ghost Fluid Method. The solution of the energy equation employs the sub-grid knowledge of Γ (t) to discretize the temperature Laplacian using second-order one-sided differences, i.e. the numerical stencil completely resides within each respective phase. To carefully evaluate the benefits or disadvantages of the GALS approach, the standard level set method is implemented and compared against the GALS predictions. The results show the expected trend that interface identification and transport are predicted noticeably better with GALS over the standard level set. This benefit carries over to the prediction of the Laplacian and temperature gradients in the neighborhood of the interface, which are directly linked to the calculation of the vaporization rate. However, when combining the calculation of interface transport and reinitialization with two-phase momentum and energy, the benefits of GALS are to some extent neutralized, and the causes for this behavior are identified and analyzed. Overall the additional computational costs associated with GALS are almost the same as those using the standard level set technique.

  18. Effect of silica nanoparticles on the phase inversion of liquid-liquid dispersions

    International Nuclear Information System (INIS)

    Asadabadi, Maliheh Raji; Abolghasemi, Hossein; Nasab, Payman Davoodi; Maragheh, Mohammad Ghannadi

    2013-01-01

    The effect of silica nanoparticles on phase inversion of liquid-liquid dispersions in a stirred vessel was investigated. The studied systems were toluene dispersed in water and vice versa. In the first set of experiments, phase inversion behavior of systems without Silica nanoparticles was evaluated and subsequent experiments were conducted in the presence of the nanoparticles. For this purpose, Silica nanoparticles of different concentrations (0.01, 0.03, 0.05, 0.07 wt%) were dispersed in water. The nanofluid stability was examined using an ultraviolet-visible (UV-vis) spectrophotometer. The results indicated that increase in silica nanoparticle concentrations up to 0.07 wt% led to increase in agitation speed of phase inversion 43-53.5% and 38.5-45% in the case of O/W and W/O dispersions, respectively. Consequently, the tendency of dispersions to inversion diminished as nanoparticle concentrations increased. Finally, 0.05 wt% of silica nanoparticle was selected as the optimum on the range studied

  19. How to separate ionic liquids: Use of Hydrophilic Interaction Liquid Chromatography and mixed mode phases

    International Nuclear Information System (INIS)

    Lamouroux, C.

    2011-01-01

    This chromatographic study deals with the development of a convenient and versatile method to separate Room Temperature Ionic Liquids. Different modes of chromatography were studied. The study attempts to answer the following question: 'what were the most important interactions for the separation of ionic liquids?'. The results show that the essential interactions to assure a good retention of RTILs are the ionic ones and that hydrophobic interactions play a role in the selectivity of the separation. The separation of five imidazolium salt with a traditional dial columns in Hydrophilic Interaction Chromatography (HILIC) was demonstrated. It shows that neutral diol grafted column allows an important retention that we assume is due to the capability of diol to develop a thick layer of water. Furthermore, stationary phase based on mixed interaction associating ion exchange and hydrophobic properties were studied. Firstly, it will be argued that it is possible to separate RTILs with a convenient retention and resolution according to a reverse phase elution with the Primesep columns made of a brush type long alkyl chain with an embedded negatively charged functional group. Secondly, a successful separation of RTILs in HILIC mode with a mixed phase column containing a cationic exchanger and a hydrophobic octyl chain length will be demonstrated. (author)

  20. Comparison of electrical and optical characteristics in gas-phase and gas-liquid phase discharges

    Energy Technology Data Exchange (ETDEWEB)

    Qazi, H. I. A.; Li, He-Ping, E-mail: liheping@tsinghua.edu.cn; Zhang, Xiao-Fei; Bao, Cheng-Yu [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Nie, Qiu-Yue [School of Electrical Engineering and Automation, Harbin Institute of Technology, Harbin, Heilongjiang Province 150001 (China)

    2015-12-15

    This paper presents an AC-excited argon discharge generated using a gas-liquid (two-phase) hybrid plasma reactor, which mainly consists of a powered needle electrode enclosed in a conical quartz tube and grounded deionized water electrode. The discharges in the gas-phase, as well as in the two-phase, exhibit two discharge modes, i.e., the low current glow-like diffuse mode and the high current streamer-like constrict mode, with a mode transition, which exhibits a negative resistance of the discharges. The optical emission spectral analysis shows that the stronger diffusion of the water vapor into the discharge region in the two-phase discharges boosts up the generation of OH (A–X) radicals, and consequently, leads to a higher rotational temperature in the water-phase plasma plume than that of the gas-phase discharges. Both the increase of the power input and the decrease of the argon flow rate result in the increase of the rotational temperature in the plasma plume of the water-phase discharge. The stable two-phase discharges with a long plasma plume in the water-phase under a low power input and gas flow rate may show a promising prospect for the degradation of organic pollutants, e.g., printing and dyeing wastewater, in the field of environmental protection.

  1. Liquid-liquid phase separation in dilute solutions of poly(styrene sulfonate) with multivalent cations: Phase diagrams, chain morphology, and impact of temperature

    Science.gov (United States)

    Hansch, Markus; Hämisch, Benjamin; Schweins, Ralf; Prévost, Sylvain; Huber, Klaus

    2018-01-01

    The dilute solution behavior of sodium poly(styrene sulfonate) is studied in the presence of trivalent Al3+ and bivalent Ba2+ cations at various levels of excess NaCl. The study evaluates the phase behavior and the morphology of the polyelectrolyte chains with increasing extent of decoration with the Al3+ and Ba2+ cations and analyses the effect of temperature on these decorated chains. The phase behavior is presented in the form of the cation concentration versus the respective poly(styrene sulfonate) concentration, recorded at the onset of precipitation. Whereas poly(styrene sulfonate) with Al3+ exhibits a linear phase boundary, denoted as the "threshold line," which increases with increasing poly(styrene sulfonate) concentration, Ba2+ cations show a threshold line which is independent of the poly(styrene sulfonate) concentration. An additional re-entrant phase, at considerably higher cation content than those of the threshold lines, is observed with Al3+ cations but not with Ba2+ cations. The threshold line and the re-entrant phase boundary form parts of the liquid-liquid phase boundary observed at the limit of low polymer concentration. The dimensions of the polyelectrolyte chains shrink considerably while approaching the respective threshold lines on increase of the Al3+ and Ba2+ cation content. However, subtle differences occur between the morphological transformation induced by Al3+ and Ba2+. Most strikingly, coils decorated with Al3+ respond very differently to temperature variations than coils decorated with Ba2+ do. As the temperature increases, the poly(styrene sulfonate) chains decrease their size in the presence of Al3+ cations but increase in size in the presence of Ba2+ cations.

  2. A high Tc superconducting liquid nitrogen level sensor

    International Nuclear Information System (INIS)

    Jin, J. X.; Liu, H. K.; Dou, S. X.; Grantham, C.; Beer, J.

    1996-01-01

    Full text: The dramatic resistance change in the superconducting-normal transition temperature range enables a high T c superconductor to be considered for designing a liquid nitrogen level sensor. A (Bi,Pb) 2 Sr 2 Ca 2 Cu 3 O 10+x Ag clad superconducting wire is selected and tested as a continuous liquid nitrogen level sensor to investigate the possibility for this application. The (Bi,Pb) 2 Sr 2 Ca 2 Cu 3 O 10+x Ag clad superconducting wire has approximately 110 K critical temperature, with more flexible and stable properties compared with bulk shape ceramic high T c superconductors. The voltage drops across the sensor are tested with different immersion lengths in liquid nitrogen. The accuracy of the HTS sensor is analysed with its dR/dT in the superconducting-normal transition range. The voltage signal is sensitive to liquid nitrogen level change, and this signal can be optimized by controlling the transport current. The problems of the Ag clad superconductor are that the Ag sheath thermal conductivity is very high, and the sensor normal resistance is low. These are the main disadvantages for using such a wire as a continuous level sensor. However, a satisfactory accuracy can be achieved by control of the transport current. A different configuration of the wire sensor is also designed to avoid this thermal influence

  3. Liquid-fog and liquid-gas phase transitions in hot nuclei

    International Nuclear Information System (INIS)

    Karnaukhov, V.A.; ); Oeschier, H.; Budzanowski, A.

    2006-01-01

    Thermal multifragmentation of hot nuclei is interpreted as the nuclear liquid-fog phase transition inside the spinodal region. The exclusive data for p(8.1 GeV) + Au collisions are analyzed within the framework of statistical model (SSM). It is found that the partition hot nuclei is specified after expansion to a volume equal to V t = (2.6 ± 0.3)V 0 . The freeze-out volume is found to be twice as large V f = (5 ± 1)V 0 . The similarity between multifragmentation and ordinary fission is discussed [ru

  4. Electrostatic Effects in Phase Transitions of Biomembranes between Cubic Phases and Lamellar Liquid-Crystalline (Lα) phase

    Science.gov (United States)

    Masum, Shah Md.; Li, Shu Jie; Tamba, Yukihiro; Yamashita, Yuko; Yamazaki, Masahito

    2004-04-01

    Elucidation of the mechanisms of transitions between cubic phase and liquid-crystalline (Lα) phase, and between different IPMS cubic phases, are essential for understanding of dynamics of biomembranes and topological transformation of lipid membranes. Recently, we found that electrostatic interactions due to surface charges of lipid membranes induce transition between cubic phase and Lα phase, and between different IPMS cubic phases. As electrostatic interactions increase, the most stable phase of a monoolein (MO) membrane changes: Q224 ⇒ Q229 ⇒ Lα. We also found that a de novo designed peptide partitioning into electrically neutral lipid membrane changed the phase stability of the MO membranes. As peptide-1 concentration increased, the most stable phase of a MO membrane changes: Q224 ⇒ Q229 ⇒Lα. In both cases, the increase in the electrostatic repulsive interaction greatly reduced the absolute value of spontaneous curvature of the MO monolayer membrane. We also investigated factors such as poly (L-lysine) and osmotic stress to control structure and phase stability of DOPA/MO membranes. Based on these results, we discuss the mechanism of the effect of electrostatic interactions on the stability of cubic phase.

  5. Standard Specification for Sampling Single-Phase Geothermal Liquid or Steam for Purposes of Chemical Analysis

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1983-01-01

    1.1 This specification covers the basic requirements for equipment to be used for the collection of uncontaminated and representative samples from single-phase geothermal liquid or steam. Geopressured liquids are included. See Fig 1.

  6. A review of solid-fluid selection options for optical-based measurements in single-phase liquid, two-phase liquid-liquid and multiphase solid-liquid flows

    Science.gov (United States)

    Wright, Stuart F.; Zadrazil, Ivan; Markides, Christos N.

    2017-09-01

    Experimental techniques based on optical measurement principles have experienced significant growth in recent decades. They are able to provide detailed information with high-spatiotemporal resolution on important scalar (e.g., temperature, concentration, and phase) and vector (e.g., velocity) fields in single-phase or multiphase flows, as well as interfacial characteristics in the latter, which has been instrumental to step-changes in our fundamental understanding of these flows, and the development and validation of advanced models with ever-improving predictive accuracy and reliability. Relevant techniques rely upon well-established optical methods such as direct photography, laser-induced fluorescence, laser Doppler velocimetry/phase Doppler anemometry, particle image/tracking velocimetry, and variants thereof. The accuracy of the resulting data depends on numerous factors including, importantly, the refractive indices of the solids and liquids used. The best results are obtained when the observational materials have closely matched refractive indices, including test-section walls, liquid phases, and any suspended particles. This paper reviews solid-liquid and solid-liquid-liquid refractive-index-matched systems employed in different fields, e.g., multiphase flows, turbomachinery, bio-fluid flows, with an emphasis on liquid-liquid systems. The refractive indices of various aqueous and organic phases found in the literature span the range 1.330-1.620 and 1.251-1.637, respectively, allowing the identification of appropriate combinations to match selected transparent or translucent plastics/polymers, glasses, or custom materials in single-phase liquid or multiphase liquid-liquid flow systems. In addition, the refractive indices of fluids can be further tuned with the use of additives, which also allows for the matching of important flow similarity parameters such as density and viscosity.

  7. Continuous fixed-bed gas-phase hydroformylation using supported ionic liquid-phase (SILP) Rh catalysts

    DEFF Research Database (Denmark)

    Riisager, Anders; Wasserscheid, Peter; Van Hal, R.

    2003-01-01

    Continuous flow gas-phase hydroformylation of propene was performed using novel supported ionic liquid-phase (SILP) catalysts containing immobilized Rh complexes of the biphosphine ligand sulfoxantphos in the ionic liquids 1-n-butyl-3-methylimidazolium hexafluorophosphate and halogen-free 1-n-butyl...

  8. Magnetic liquid metal two-phase flow research. Phase 1. Final report

    International Nuclear Information System (INIS)

    Graves, R.D.

    1983-04-01

    The Phase I research demonstrates the feasibility of the magnetic liquid metal (MLM) two-phase flow concept. A dispersion analysis is presented based on a complete set of two-phase-flow equations augmented to include stresses due to magnetic polarization of the fluid. The analysis shows that the stability of the MLM two-phase flow is determined by the magnetic Mach number, the slip ratio, geometry of the flow relative to the applied magnetic field, and by the voidage dependence of the interfacial forces. Results of a set of experiments concerned with magnetic effects on the dynamics of single bubble motion in an aqueous-based, viscous, conducting magnetic fluid are presented. Predictions in the theoretical literature are qualitatively verified using a bench-top experimental apparatus. In particular, applied magnetic fields are seen to lead to reduced bubble size at fixed generating orifice pressure

  9. The NA62 Liquid Krypton Electromagnetic Calorimeter Level 0 Trigger

    CERN Document Server

    INSPIRE-00293812; Paoluzzi, Giovanni; Salamon, Andrea; Salina, Gaetano; Santovetti, Emanuele; Scarfi, Francesco M.; Bonaiuto, Vincenzo; Sargeni, Fausto

    2012-01-01

    The NA62 experiment at CERN SPS aims to measure the Branching Ratio of the very rare kaon decay K+ -> pi+ nu nubar collecting O(100) events with a 10% background to make a stringent test of the Standard Model. One of the main backgrounds to the proposed measurement is represented by the K+ -> pi+ pi0 decay. To suppress this background an efficient photo veto system is foreseen. In the 1-10 mrad angular region the NA48 high performance liquid krypton electromagnetic calorimeter is used. The design, implementation and current status of the Liquid Krypton Electromagnetic Calorimeter Level 0 Trigger are presented.

  10. The NA62 Liquid Krypton Electromagnetic Calorimeter Level 0 Trigger

    CERN Document Server

    INSPIRE-00646848; Fucci, Adolfo; Paoluzzi, Giovanni; Salamon, Andrea; Salina, Gaetano; Santovetti, Emanuele; Scarfi, Francesco M.; Sargeni, Fausto

    2011-01-01

    The NA62 experiment at CERN SPS aims to measure the Branching Ratio of the very rare kaon decay K+ -> pi+ nu nubar collecting O(100) events with a 10% background to make a stringent test of the Standard Model. One of the main backgrounds to the proposed measurement is represented by the K+ -> pi+ pi0 decay. To suppress this background an efficient photo veto system is foreseen. In the 1-10 mrad angular region the NA48 high performance liquid krypton electromagnetic calorimeter is used. The design, implementation and current status of the Liquid Krypton Electromagnetic Calorimeter Level 0 Trigger are presented.

  11. Liquid phase micro-extraction: Towards the green methodology for ultratrace metals determination in aquatic ecosystems

    Directory of Open Access Journals (Sweden)

    López-López J. A.

    2013-04-01

    Full Text Available Heavy metals are normally found, in natural waters, in very low concentrations. Some of them are essential for life in low level; however, in higher level they are toxic. Therefore, analyzing their bio-available fraction is of main interest. Standard methodology is based in the collection of a number of samples from a water body. Collected samples must be stored, pre-treated and then analyzed. Pre-treatment usually involves pre-concentrating the metal, with the corresponding risk of contamination or loss of analyte. This way, punctual information is obtained from every sampling campaign. As an alternative, passive sampling techniques allow the continuous and coupled sampling-pre-treatment for heavy metals analysis, giving a better approach in the characterization of the studied water body. Liquid phase micro-extraction (LPME is a green analytical alternative for liquid-liquid extraction that promotes a reduction of sample volume, solvent needed and waste generation. Using these systems, polypropylene hollow fibers (HF with pores in their walls can be used. A few micro-liters of organic solvent are supported in the pores. The sample is placed in the outer part of the fiber and a receiving phase is placed in its inner part, allowing continuous liquid extraction of the metal from the sample. Several fibers with different physical features have been employed to analyzed total concentration and bio-availability of some heavy metals (Ag, Ni, Cu in natural water samples. Thanks to fibers configuration, devices for passive sampling based in HF-LPME could be designed. Advantages of this methodology over existing ones are supported because the receiving phase is liquid. As a consequence, retained metals do not need to be eluted from the acceptor prior to instrumental analysis.

  12. How ionic species structure influences phase structure and transitions from protic ionic liquids to liquid crystals to crystals.

    Science.gov (United States)

    Greaves, Tamar L; Broomhall, Hayden; Weerawardena, Asoka; Osborne, Dale A; Canonge, Bastien A; Drummond, Calum J

    2017-12-14

    The phase behaviour of n-alkylammonium (C6 to C16) nitrates and formates has been characterised using synchrotron small angle and wide angle X-ray scattering (SAXS/WAXS), differential scanning calorimetry (DSC), cross polarised optical microscopy (CPOM) and Fourier transform infrared spectroscopy (FTIR). The protic salts may exist as crystalline, liquid crystalline or ionic liquid materials depending on the alkyl chain length and temperature. n-Alkylammonium nitrates with n ≥ 6 form thermotropic liquid crystalline (LC) lamellar phases, whereas n ≥ 8 was required for the formate series to form this LC phase. The protic ionic liquid phase showed an intermediate length scale nanostructure resulting from the segregation of the polar and nonpolar components of the ionic liquid. This segregation was enhanced for longer n-alkyl chains, with a corresponding increase in the correlation length scale. The crystalline and liquid crystalline phases were both lamellar. Phase transition temperatures, lamellar d-spacings, and liquid correlation lengths for the n-alkylammonium nitrates and formates were compared with those for n-alkylammonium chlorides and n-alkylamines. Plateau regions in the liquid crystalline to liquid phase transition temperatures as a function of n for the n-alkylammonium nitrates and formates are consistent with hydrogen-bonding and cation-anion interactions between the ionic species dominating alkyl chain-chain van der Waals interactions, with the exception of the mid chained hexyl- and heptylammonium formates. The d-spacings of the lamellar phases for both the n-alkylammonium nitrates and formates were consistent with an increase in chain-chain layer interdigitation within the bilayer-based lamellae with increasing alkyl chain length, and they were comparable to the n-alkylammonium chlorides.

  13. Structure analysis of turbulent liquid phase by POD and LSE techniques

    Energy Technology Data Exchange (ETDEWEB)

    Munir, S., E-mail: shahzad-munir@comsats.edu.pk; Muthuvalu, M. S.; Siddiqui, M. I. [Department of Fundamental and Applied Science, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak Darul Ridzuan (Malaysia); Heikal, M. R., E-mail: morgan.heikal@petronas.com.my; Aziz, A. Rashid A., E-mail: morgan.heikal@petronas.com.my [Department of Mechanical Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak Darul Ridzuan (Malaysia)

    2014-10-24

    In this paper, vortical structures and turbulence characteristics of liquid phase in both single liquid phase and two-phase slug flow in pipes were studied. Two dimensional velocity vector fields of liquid phase were obtained by Particle image velocimetry (PIV). Two cases were considered one single phase liquid flow at 80 l/m and second slug flow by introducing gas at 60 l/m while keeping liquid flow rate same. Proper orthogonal decomposition (POD) and Linear stochastic estimation techniques were used for the extraction of coherent structures and analysis of turbulence in liquid phase for both cases. POD has successfully revealed large energy containing structures. The time dependent POD spatial mode coefficients oscillate with high frequency for high mode numbers. The energy distribution of spatial modes was also achieved. LSE has pointed out the coherent structured for both cases and the reconstructed velocity fields are in well agreement with the instantaneous velocity fields.

  14. Structure analysis of turbulent liquid phase by POD and LSE techniques

    International Nuclear Information System (INIS)

    Munir, S.; Muthuvalu, M. S.; Siddiqui, M. I.; Heikal, M. R.; Aziz, A. Rashid A.

    2014-01-01

    In this paper, vortical structures and turbulence characteristics of liquid phase in both single liquid phase and two-phase slug flow in pipes were studied. Two dimensional velocity vector fields of liquid phase were obtained by Particle image velocimetry (PIV). Two cases were considered one single phase liquid flow at 80 l/m and second slug flow by introducing gas at 60 l/m while keeping liquid flow rate same. Proper orthogonal decomposition (POD) and Linear stochastic estimation techniques were used for the extraction of coherent structures and analysis of turbulence in liquid phase for both cases. POD has successfully revealed large energy containing structures. The time dependent POD spatial mode coefficients oscillate with high frequency for high mode numbers. The energy distribution of spatial modes was also achieved. LSE has pointed out the coherent structured for both cases and the reconstructed velocity fields are in well agreement with the instantaneous velocity fields

  15. Transition Temperatures of Thermotropic Liquid Crystals from the Local Binary Gray Level Cooccurrence Matrix

    Directory of Open Access Journals (Sweden)

    S. Sreehari Sastry

    2012-01-01

    Full Text Available This paper presents a method which combines the statistical analysis with texture structural analysis called Local Binary Gray Level Cooccurrence Matrix (LBGLCM to investigate the phase transition temperatures of thermotropic p,n-alkyloxy benzoic acid (nOBA, n=4,6,8,10 and 12 liquid crystals. Textures of the homeotropically aligned liquid crystal compounds are recorded as a function of temperature using polarizing optical microscope attached to the hot stage and high resolution camera. In this method, second-order statistical parameters (contrast, energy, homogeneity, and correlation are extracted from the LBGLCM of the textures. The changes associatedwiththe values of extracted parameters as a function of temperature are a helpful process to identify the phases and phase transition temperatures of the samples. Results obtained from this method have validity and are in good agreement with the literature.

  16. μ-'Diving suit' for liquid-phase high-Q resonant detection.

    Science.gov (United States)

    Yu, Haitao; Chen, Ying; Xu, Pengcheng; Xu, Tiegang; Bao, Yuyang; Li, Xinxin

    2016-03-07

    A resonant cantilever sensor is, for the first time, dressed in a water-proof 'diving suit' for real-time bio/chemical detection in liquid. The μ-'diving suit' technology can effectively avoid not only unsustainable resonance due to heavy liquid-damping, but also inevitable nonspecific adsorption on the cantilever body. Such a novel technology ensures long-time high-Q resonance of the cantilever in solution environment for real-time trace-concentration bio/chemical detection and analysis. After the formation of the integrated resonant micro-cantilever, a patterned photoresist and hydrophobic parylene thin-film are sequentially formed on top of the cantilever as sacrificial layer and water-proof coat, respectively. After sacrificial-layer release, an air gap is formed between the parylene coat and the cantilever to protect the resonant cantilever from heavy liquid damping effect. Only a small sensing-pool area, located at the cantilever free-end and locally coated with specific sensing-material, is exposed to the liquid analyte for gravimetric detection. The specifically adsorbed analyte mass can be real-time detected by recording the frequency-shift signal. In order to secure vibration movement of the cantilever and, simultaneously, reject liquid leakage from the sensing-pool region, a hydrophobic parylene made narrow slit structure is designed surrounding the sensing-pool. The anti-leakage effect of the narrow slit and damping limited resonance Q-factor are modelled and optimally designed. Integrated with electro-thermal resonance excitation and piezoresistive frequency readout, the cantilever is embedded in a micro-fluidic chip to form a lab-chip micro-system for liquid-phase bio/chemical detection. Experimental results show the Q-factor of 23 in water and longer than 20 hours liquid-phase continuous working time. Loaded with two kinds of sensing-materials at the sensing-pools, two types of sensing chips successfully show real-time liquid-phase detection to ppb-level

  17. Nonaqueous phase liquids: Searching for the needle in the haystack

    International Nuclear Information System (INIS)

    Haas, J.W. III; Carrabba, M.M.; Forney, R.W.

    1995-01-01

    Two complementary sensors that can locate and identify Nonaqueous Phase Liquids (NAPLs) such as chlorinated hydrocarbon solvents and fuels in the subsurface have been developed. The sensors are based on Raman and fluorescence spectroscopies and combine down-hole fiber optic probes with up-hole spectrometers. The probes are designed for deployment in cone penetrometers for real-time, in situ detection of contaminants. Near-infrared laser excitation is used with the Raman system to minimize soil fluorescence background. A mercury lamp is employed in the fluorescence probe to overcome the poor UV transmission of optical fibers and to reduce costs relative to laser-based instruments. Response of the fluorescence system to fuels in soil is linear with concentration. Lower detection limits are in the low ppm range for real-time (1 sec) acquisitions

  18. Acoustic levitation of liquid drops: Dynamics, manipulation and phase transitions.

    Science.gov (United States)

    Zang, Duyang; Yu, Yinkai; Chen, Zhen; Li, Xiaoguang; Wu, Hongjing; Geng, Xingguo

    2017-05-01

    The technique of acoustic levitation normally produces a standing wave and the potential well of the sound field can be used to trap small objects. Since no solid surface is involved it has been widely applied for the study of fluid physics, nucleation, bio/chemical processes, and various forms of soft matter. In this article, we survey the works on drop dynamics in acoustic levitation, focus on how the dynamic behavior is related to the rheological properties and discuss the possibility to develop a novel rheometer based on this technique. We review the methods and applications of acoustic levitation for the manipulation of both liquid and solid samples and emphasize the important progress made in the study of phase transitions and bio-chemical analysis. We also highlight the possible open areas for future research. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Recovery of light nonaqueous-phase liquids without groundwater pumping

    International Nuclear Information System (INIS)

    Markley, D.E.; Prince-Larsen, N.

    1995-01-01

    This paper outlines recovery of light nonaqueous-phase liquids (LNAPL) encountered in the subsurface at a remote natural gas facility. Remediation of LNAPL in the subsurface usually begins with dual pumping of LNAPL and groundwater. However, regulations required that only LNAPL be recovered. Methods were sought for recovering LNAPL from groundwater without pumping groundwater to the surface. Alternative methods of LNAPL recovery, using a variety of skimming pumps, included: LNAPL recovery from large-diameter wells; LNAPL recovery from trenches; LNAPL recovery from small-diameter wells; and vacuum-enhanced recovery of LNAPL while skimming with a belt skimmer. Based on the goals of the site owner and the costs associated with each alternative examined, the recommended method for recovering LNAPL without groundwater pumping was recovery of LNAPL while skimming with a belt skimmer. This paper discusses both the advantages and limitations of this technique

  20. Comparison of liquid and supercritical fluid chromatography mobile phases for enantioselective separations on polysaccharide stationary phases.

    Science.gov (United States)

    Khater, Syame; Lozac'h, Marie-Anne; Adam, Isabelle; Francotte, Eric; West, Caroline

    2016-10-07

    Analysis and production of enantiomerically pure compounds is a major topic of interest when active pharmaceutical ingredients are concerned. Enantioselective chromatography has become a favourite both at the analytical and preparative scales. High-performance liquid chromatography (HPLC) and supercritical fluid chromatography (SFC) are dominating the scene and are often seen as complementary techniques. Nowadays, for economic and ecologic reasons, SFC may be preferred over normal-phase HPLC (NPLC) as it allows significant reductions in solvent consumption. However, the transfer of NPLC methods to SFC is not always straightforward. In this study, we compare the retention of achiral molecules and separation of enantiomers under supercritical fluid (carbon dioxide with ethanol or isopropanol) and liquid normal-phase (heptane with ethanol or isopropanol) elution modes with polysaccharide stationary phases in order to explore the differences between the retention and enantioseparation properties between the two modes. Chemometric methods (namely quantitative structure-retention relationships and discriminant analysis) are employed to compare the results obtained on a large set of analytes (171 achiral probes and 97 racemates) and gain some understanding on the retention and separation mechanisms. The results indicate that, contrary to popular belief, carbon dioxide - solvent SFC mobile phases are often weaker eluents than liquid mobile phases. It appears that SFC and NPLC elution modes provide different retention mechanisms. While some enantioseparations are unaffected, facilitating the transfer between the two elution modes, other enantioseparations may be drastically different due to different types and strength of interactions contributing to enantioselectivity. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Interplay of the Glass Transition and the Liquid-Liquid Phase Transition in Water

    Science.gov (United States)

    Giovambattista, Nicolas; Loerting, Thomas; Lukanov, Boris R.; Starr, Francis W.

    2012-01-01

    Water has multiple glassy states, often called amorphous ices. Low-density (LDA) and high-density (HDA) amorphous ice are separated by a dramatic, first-order like phase transition. It has been argued that the LDA-HDA transformation connects to a first-order liquid-liquid phase transition (LLPT) above the glass transition temperature Tg. Direct experimental evidence of the LLPT is challenging to obtain, since the LLPT occurs at conditions where water rapidly crystallizes. In this work, we explore the implications of a LLPT on the pressure dependence of Tg(P) for LDA and HDA by performing computer simulations of two water models – one with a LLPT, and one without. In the absence of a LLPT, Tg(P) for all glasses nearly coincide. When there is a LLPT, different glasses exhibit dramatically different Tg(P) which are directly linked with the LLPT. Available experimental data for Tg(P) are only consistent with the scenario including a LLPT. PMID:22550566

  2. Nanomaterials as stationary phases and supports in liquid chromatography.

    Science.gov (United States)

    Beeram, Sandya R; Rodriguez, Elliott; Doddavenkatanna, Suresh; Li, Zhao; Pekarek, Allegra; Peev, Darin; Goerl, Kathryn; Trovato, Gianfranco; Hofmann, Tino; Hage, David S

    2017-10-01

    The development of various nanomaterials over the last few decades has led to many applications for these materials in liquid chromatography (LC). This review will look at the types of nanomaterials that have been incorporated into LC systems and the applications that have been explored for such systems. A number of carbon-based nanomaterials and inorganic nanomaterials have been considered for use in LC, ranging from carbon nanotubes, fullerenes and nanodiamonds to metal nanoparticles and nanostructures based on silica, alumina, zirconia and titanium dioxide. Many ways have been described for incorporating these nanomaterials into LC systems. These methods have included covalent immobilization, adsorption, entrapment, and the synthesis or direct development of nanomaterials as part of a chromatographic support. Nanomaterials have been used in many types of LC. These applications have included the reversed-phase, normal-phase, ion-exchange, and affinity modes of LC, as well as related methods such as chiral separations, ion-pair chromatography and hydrophilic interaction liquid chromatography. Both small and large analytes (e.g., dyes, drugs, amino acids, peptides and proteins) have been used to evaluate possible applications for these nanomaterial-based methods. The use of nanomaterials in columns, capillaries and planar chromatography has been considered as part of these efforts. Potential advantages of nanomaterials in these applications have included their good chemical and physical stabilities, the variety of interactions many nanomaterials can have with analytes, and their unique retention properties in some separation formats. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Origins of phase contrast in the atomic force microscope in liquids

    OpenAIRE

    Melcher, John; Carrasco, Carolina; Xu, Xianfan; Carrascosa, Jose L; Gomez-Herrero, Julio; Jose de Pablo, Pedro; Raman, Arvind

    2009-01-01

    We study the physical origins of phase contrast in dynamic atomic force microscopy (dAFM) in liquids where low-stiffness microcantilever probes are often used for nanoscale imaging of soft biological samples with gentle forces. Under these conditions, we show that the phase contrast derives primarily from a unique energy flow channel that opens up in liquids due to the momentary excitation of higher eigenmodes. Contrary to the common assumption, phase-contrast images in liquids using soft mic...

  4. Acid fractionation for low level liquid waste cleanup and recycle

    International Nuclear Information System (INIS)

    Gombert, D. II; McIntyre, C.V.; Mizia, R.E.; Schindler, R.E.

    1990-01-01

    At the Idaho Chemical Processing Plant, low level liquid wastes containing small amounts of radionuclides are concentrated via a thermosyphon evaporator for calcination with high level waste, and the evaporator condensates are discharged with other plant wastewater to a percolation pond. Although all existing discharge guidelines are currently met, work has been done to reduce all waste water discharges to an absolute minimum. In this regard, a 15-tray acid fractionation column will be used to distill the mildly acidic evaporator condensates into concentrated nitric acid for recycle in the plant. The innocuous overheads from the fractionator having a pH greater than 2, are superheated and HEPA filtered for atmospheric discharge. Nonvolatile radionuclides are below detection limits. Recycle of the acid not only displaces fresh reagent, but reduces nitrate burden to the environment, and completely eliminates routine discharge of low level liquid wastes to the environment

  5. Interplay of the Glass Transition and the Liquid-Liquid Phase Transition in Water

    Science.gov (United States)

    Giovambattista, Nicolas

    2013-03-01

    Most liquids can form a single glass or amorphous state when cooled sufficiently fast (in order to prevent crystallization). However, there are a few substances that are relevant to scientific and technological applications which can exist in at least two different amorphous states, a property known as polyamorphism. Examples include silicon, silica, and in particular, water. In the case of water, experiments show the existence of a low-density (LDA) and high-density (HDA) amorphous ice that are separated by a dramatic, first-order like phase transition. It has been argued that the LDA-HDA transformation evolves into a first-order liquid-liquid phase transition (LLPT) at temperatures above the glass transition temperature Tg. However, obtaining direct experimental evidence of the LLPT has been challenging since the LLPT occurs at conditions where water rapidly crystallizes. In this talk, I will (i) discuss the general phenomenology of polyamorphism in water and its implications, and (ii) explore the effects of a LLPT on the pressure dependence of Tg(P) for LDA and HDA. Our study is based on computer simulations of two water models - one with a LLPT (ST2 model), and one without (SPC/E model). In the absence of a LLPT, Tg(P) for all glasses nearly coincide. Instead, when there is a LLPT, different glasses exhibit dramatically different Tg(P) loci which are directly linked with the LLPT. Available experimental data for Tg(P) are only consistent with the scenario that includes a LLPT (ST2 model) and hence, our results support the view that a LLPT may exist for the case of water.

  6. One- and two-phase anaerobic digestion of ley crop silage with and without liquid recirculation

    Energy Technology Data Exchange (ETDEWEB)

    Nordberg, Aa

    1996-10-01

    In this study the effects of liquid recirculation on hydrolysis and methanogenesis in one- and two-phase biogas processes were investigated in comparison with water-diluted processes. The operation of a water-diluted one-phase process resulted in process imbalances at a low loading rate. In a water-diluted two-phase process the fibre degrading capability was lost. The reason for the poor process performance was due to a deficiency in trace elements, since the supplementation of cobalt resulted in an increased conversion rate of acetate. The recirculation of process liquid resulted in an accumulation of different compounds which initially stabilized one-phase processes and stimulated the hydrolysis and the methane production in the liquefaction-acidogenesis stage of a two-phase process. However, upon continuous recirculation the concentration of free ammonia reached toxic levels, which resulted in a decrease in the methane yield both in the methanogenic reactor of the two-phase process and in the one-phase process. Due to the decreased methane production, acids started to accumulate which subsequently inhibited the hydrolysis in the one-phase process. The systematic variation in the processes were evaluated using principal component analysis and principal component regression. The interpretation of the dynamic behaviour of the processes was facilitated by the use of score plots and loading plots. The results indicate that ley crops do not meet the nutrient requirements of the bacteria in anaerobic digestion. Thus, the low content of trace elements and the high content of protein which subsequently will cause toxic levels of ammonia in digesting system with low water consumption, suggests co-digestion with supplementary feedstocks. 95 refs, 5 figs, 3 tabs

  7. Low level radioactive liquid waste decontamination by electrochemical way

    International Nuclear Information System (INIS)

    Tronche, E.

    1994-10-01

    As part of the work on decontamination treatments for low level radioactive aqueous liquid wastes, the study of an electro-chemical process has been chosen by the C.E.A. at the Cadarache research centre. The first part of this report describes the main methods used for the decontamination of aqueous solutions. Then an electro-deposition process and an electro-dissolution process are compared on the basis of the decontamination results using genuine radioactive aqueous liquid waste. For ruthenium decontamination, the former process led to very high yields (99.9 percent eliminated). But the elimination of all the other radionuclides (antimony, strontium, cesium, alpha emitters) was only favoured by the latter process (90 percent eliminated). In order to decrease the total radioactivity level of the waste to be treated, we have optimized the electro-dissolution process. That is why the chemical composition of the dissolved anode has been investigated by a mixture experimental design. The radionuclides have been adsorbed on the precipitating products. The separation of the precipitates from the aqueous liquid enabled us to remove the major part of the initial activity. On the overall process some operations have been investigated to minimize waste embedding. Finally, a pilot device (laboratory scale) has been built and tested with genuine radioactive liquid waste. (author). 77 refs., 41 tabs., 55 figs., 4 appendixes

  8. Purification of flavonoids from licorice using an off-line preparative two-dimensional normal-phase liquid chromatography/reversed-phase liquid chromatography method.

    Science.gov (United States)

    Fan, Yunpeng; Fu, Yanhui; Fu, Qing; Cai, Jianfeng; Xin, Huaxia; Dai, Mei; Jin, Yu

    2016-07-01

    An orthogonal (71.9%) off-line preparative two-dimensional normal-phase liquid chromatography/reversed-phase liquid chromatography method coupled with effective sample pretreatment was developed for separation and purification of flavonoids from licorice. Most of the nonflavonoids were firstly removed using a self-made Click TE-Cys (60 μm) solid-phase extraction. In the first dimension, an industrial grade preparative chromatography was employed to purify the crude flavonoids. Click TE-Cys (10 μm) was selected as the stationary phase that provided an excellent separation with high reproducibility. Ethyl acetate/ethanol was selected as the mobile phase owing to their excellent solubility for flavonoids. Flavonoids co-eluted in the first dimension were selected for further purification using reversed-phase liquid chromatography. Multiple compounds could be isolated from one normal-phase fraction and some compounds with bad resolution in one-dimensional liquid chromatography could be prepared in this two-dimensional system owing to the orthogonal separation. Moreover, this two-dimensional liquid chromatography method was beneficial for the preparation of relatively trace flavonoid compounds, which were enriched in the first dimension and further purified in the second dimension. Totally, 24 flavonoid compounds with high purity were obtained. The results demonstrated that the off-line two-dimensional liquid chromatography method was effective for the preparative separation and purification of flavonoids from licorice. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Application of the level set method for multi-phase flow computation in fusion engineering

    International Nuclear Information System (INIS)

    Luo, X-Y.; Ni, M-J.; Ying, A.; Abdou, M.

    2006-01-01

    Numerical simulation of multi-phase flow is essential to evaluate the feasibility of a liquid protection scheme for the power plant chamber. The level set method is one of the best methods for computing and analyzing the motion of interface among the multi-phase flow. This paper presents a general formula for the second-order projection method combined with the level set method to simulate unsteady incompressible multi-phase flow with/out phase change flow encountered in fusion science and engineering. The third-order ENO scheme and second-order semi-implicit Crank-Nicholson scheme is used to update the convective and diffusion term. The numerical results show this method can handle the complex deformation of the interface and the effect of liquid-vapor phase change will be included in the future work

  10. Comparison of solid and liquid-phase bioassays using ecoscores to assess contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Lors, Christine [Universite Lille Nord de France, 1bis rue Georges Lefevre, 59044 Lille Cedex (France); Ecole des Mines de Douai, LGCgE-MPE-GCE, 941 rue Charles-Bourseul, 59500 Douai (France); Centre National de Recherche sur les Sites et Sols Pollues, 930 Boulevard Lahure, BP 537, 59505 Douai Cedex (France); Ponge, Jean-Francois, E-mail: ponge@mnhn.fr [Museum National d' Histoire Naturelle, Departement Ecologie et Gestion de la Biodiversite, CNRS UMR 7179, 4 Avenue du Petit-Chateau, 91800 Brunoy (France); Martinez Aldaya, Maite [Museum National d' Histoire Naturelle, Departement Ecologie et Gestion de la Biodiversite, CNRS UMR 7179, 4 Avenue du Petit-Chateau, 91800 Brunoy (France); Damidot, Denis [Universite Lille Nord de France, 1bis rue Georges Lefevre, 59044 Lille Cedex (France); Ecole des Mines de Douai, LGCgE-MPE-GCE, 941 rue Charles-Bourseul, 59500 Douai (France)

    2011-10-15

    Bioassays on aqueous and solid phases of contaminated soils were compared, belonging to a wide array of trophic and response levels and using ecoscores for evaluating ecotoxicological and genotoxicological endpoints. The method was applied to four coke factory soils contaminated mainly with PAHs, but also to a lesser extent by heavy metals and cyanides. Aquatic bioassays do not differ from terrestrial bioassays when scaling soils according to toxicity but they are complementary from the viewpoint of ecological relevance. Both aquatic and terrestrial endpoints are strongly correlated with concentrations of 3-ring PAHs. This evaluation procedure allows us to propose a cost-effective battery which embraces a wide array of test organisms and response levels: it includes two rapid bioassays (Microtox) and springtail avoidance), a micronucleus test and three bioassays of a longer duration (algal growth, lettuce germination and springtail reproduction). This battery can be recommended for a cost-effective assessment of polluted/remediated soils. - Highlights: > Comparison of liquid- and solid-phase bioassays on contaminated soils, using ecoscores. > Complementarity of liquid- and solid-phase bioassays for the evaluation of environmental hazards. > Proposal for a restricted battery of 5 most sensitive tests. > Use of this restricted battery for a cost-effective assessment of polluted/remediated soils. - Aqueous and solid phases of contaminated soils give similar results in terms of toxicity but are complementary for the evaluation of environmental hazards by ecoscores.

  11. Comparison of solid and liquid-phase bioassays using ecoscores to assess contaminated soils

    International Nuclear Information System (INIS)

    Lors, Christine; Ponge, Jean-Francois; Martinez Aldaya, Maite; Damidot, Denis

    2011-01-01

    Bioassays on aqueous and solid phases of contaminated soils were compared, belonging to a wide array of trophic and response levels and using ecoscores for evaluating ecotoxicological and genotoxicological endpoints. The method was applied to four coke factory soils contaminated mainly with PAHs, but also to a lesser extent by heavy metals and cyanides. Aquatic bioassays do not differ from terrestrial bioassays when scaling soils according to toxicity but they are complementary from the viewpoint of ecological relevance. Both aquatic and terrestrial endpoints are strongly correlated with concentrations of 3-ring PAHs. This evaluation procedure allows us to propose a cost-effective battery which embraces a wide array of test organisms and response levels: it includes two rapid bioassays (Microtox) and springtail avoidance), a micronucleus test and three bioassays of a longer duration (algal growth, lettuce germination and springtail reproduction). This battery can be recommended for a cost-effective assessment of polluted/remediated soils. - Highlights: → Comparison of liquid- and solid-phase bioassays on contaminated soils, using ecoscores. → Complementarity of liquid- and solid-phase bioassays for the evaluation of environmental hazards. → Proposal for a restricted battery of 5 most sensitive tests. → Use of this restricted battery for a cost-effective assessment of polluted/remediated soils. - Aqueous and solid phases of contaminated soils give similar results in terms of toxicity but are complementary for the evaluation of environmental hazards by ecoscores.

  12. Flashing liquid jets and two-phase droplet dispersion

    International Nuclear Information System (INIS)

    Cleary, Vincent; Bowen, Phil; Witlox, Henk

    2007-01-01

    The large-scale release of a liquid contained at upstream conditions above its local atmospheric boiling point is a scenario often given consideration in process industry risk analysis. Current-hazard quantification software often employs simplistic equilibrium two-phase approaches. Scaled water experiments have been carried out measuring droplet velocity and droplet size distributions for a range of exit orifice aspect ratios (L/d) and conditions representing low to high superheat. 2D Phase-Doppler Anemometry has been utilised to characterise droplet kinematics and spray quality. Droplet size correlations have been developed for non-flashing, the transition between non-flashing and flashing, and fully flashing jets. Using high-speed shadowography, transition between regimes is defined in terms of criteria identified in the external flow structure. An overview companion paper provides a wider overview of the problem and reports implementation of these correlations into consequence models and subsequent validation. The fluid utilised throughout is water, hence droplet correlations are developed in non-dimensional form to allow extrapolation to other fluids through similarity scaling, although verification of model performance for other fluids is required in future studies. Data is reduced via non-dimensionalisation in terms of the Weber number and Jakob number, essentially representing the fluid mechanics and thermodynamics of the system, respectively. A droplet-size distribution correlation has also been developed, conveniently presented as a volume undersize distribution based on the Rosin-Rammler distribution. Separate correlations are provided for sub-cooled mechanical break-up and fully flashing jets. This form of correlation facilitates rapid estimates of likely mass rainout quantities, as well as full distribution information for more rigorous two-phase thermodynamic modelling in the future

  13. Treatment of low-level liquid radioactive wastes by electrodialysis

    International Nuclear Information System (INIS)

    DelDebbio, J.A.; Donovan, R.I.

    1986-01-01

    This paper presents the results of pilot plant studies on the use of electrodialysis (ED) for the removal of radioactive and chemical contaminants from acidic low-level radioactive wastes resulting from nuclear fuel reprocessing operations. Decontamination efficiencies are reported for strontium-90, cesium-137, iodine-129, ruthenium-106 and mercury. Data for contaminant adsorption on ED membranes and liquid waste volumes generated are also presented

  14. Experimental hydrophobicity parameters of perfluorinated alkylated substances from reversed-phase high performance liquid chromatography

    NARCIS (Netherlands)

    de Voogt, P.; Zurano, L.; Serné, P.; Haftka, J.J.H.

    2012-01-01

    Capacity factors of perfluorinated alkylated substances were obtained from isocratic reversed-phase high-performance liquid chromatography-mass spectrometry experiments at different organic modifier strengths of the mobile phase. The resulting capacity factor v. modifier strengths plots were

  15. Preparation and evaluation of surface-bonded tricationic ionic liquid silica as stationary phases for high-performance liquid chromatography.

    Science.gov (United States)

    Qiao, Lizhen; Shi, Xianzhe; Lu, Xin; Xu, Guowang

    2015-05-29

    Two tricationic ionic liquids were prepared and then bonded onto the surface of supporting silica materials through "thiol-ene" click chemistry as new stationary phases for high-performance liquid chromatography. The obtained columns of tricationic ionic liquids were evaluated respectively in the reversed-phase liquid chromatography (RPLC) mode and hydrophilic interaction liquid chromatography (HILIC) mode, and possess ideal column efficiency of 80,000 plates/m in the RPLC mode with naphthalene as the test solute. The tricationic ionic liquid stationary phases exhibit good hydrophobic and shape selectivity to hydrophobic compounds, and RPLC retention behavior with multiple interactions. In the HILIC mode, the retention and selectivity were evaluated through the efficient separation of nucleosides and bases as well as flavonoids, and the typical HILIC retention behavior was demonstrated by investigating retention changes of hydrophilic solutes with water volume fraction in mobile phase. The results show that the tricationic ionic liquid columns possess great prospect for applications in analysis of hydrophobic and hydrophilic samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Growth of cadmium zinc telluride by liquid phase electroepitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Armour, N.; Dost, S. [Crystal Growth Laboratory, Faculty of Engineering, University of Victoria, Victoria BC, V8W 3P6 (Canada); Sheibani, H. [Department of Industrial Engineering, Alhosn University, Abu Dhabi (United Arab Emirates)

    2006-10-15

    This study was undertaken to examine the feasibility of growing CdZnTe by liquid phase electroepitaxy. Based on our successful LPEE system of GaInAs, a new crucible to grow CdZnTe was developed. The development presented numerous difficulties. The physical properties of CdZnTe make this material very difficult to grow. All components of the system were investigated. Electromigration of the solute across the solution carries species towards the growth interface. In liquid Cd-Zn-Te, the CdTe and ZnTe species remain associated, contrary to the GaInAs system. Experiments showed that LPEE growth of CdZnTe is possible and the electromigration mechanism functions well in the CdZnTe solution. Despite this, other problems remained with the new LPEE system. The preparation of the solution proved difficult without pressurizing the LPEE crucible. Control of the reaction required the use of pre-compounded CdTe and ZnTe. Proper control of the solution saturation is imperative to ensure minimal dissolution of the seed prior to growth initiation and a reasonable growth rate during growth. The solution remained an issue during the duration of growth due to the high vapor pressures of the constituents. Tellurium evaporation during growth could lower solution volume until electrical contact across the solution is broken. Careful preparation of appropriate solution volume was imperative for successful growth. In LPEE, a uniform electric current passage across the growth interface is necessary for uniform and stable growth interface. This requires the design of a uniform contact zone between the bottom graphite electrode and the seed crystal. The contact zone issue was not adequately resolved in this study. However, a number of successful growth runs were achieved despite the electrical contact problems. Results show that the LPEE of growth CdZnTe is feasible. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  17. Growth of cadmium zinc telluride by liquid phase electroepitaxy

    International Nuclear Information System (INIS)

    Armour, N.; Dost, S.; Sheibani, H.

    2006-01-01

    This study was undertaken to examine the feasibility of growing CdZnTe by liquid phase electroepitaxy. Based on our successful LPEE system of GaInAs, a new crucible to grow CdZnTe was developed. The development presented numerous difficulties. The physical properties of CdZnTe make this material very difficult to grow. All components of the system were investigated. Electromigration of the solute across the solution carries species towards the growth interface. In liquid Cd-Zn-Te, the CdTe and ZnTe species remain associated, contrary to the GaInAs system. Experiments showed that LPEE growth of CdZnTe is possible and the electromigration mechanism functions well in the CdZnTe solution. Despite this, other problems remained with the new LPEE system. The preparation of the solution proved difficult without pressurizing the LPEE crucible. Control of the reaction required the use of pre-compounded CdTe and ZnTe. Proper control of the solution saturation is imperative to ensure minimal dissolution of the seed prior to growth initiation and a reasonable growth rate during growth. The solution remained an issue during the duration of growth due to the high vapor pressures of the constituents. Tellurium evaporation during growth could lower solution volume until electrical contact across the solution is broken. Careful preparation of appropriate solution volume was imperative for successful growth. In LPEE, a uniform electric current passage across the growth interface is necessary for uniform and stable growth interface. This requires the design of a uniform contact zone between the bottom graphite electrode and the seed crystal. The contact zone issue was not adequately resolved in this study. However, a number of successful growth runs were achieved despite the electrical contact problems. Results show that the LPEE of growth CdZnTe is feasible. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  18. Preparation and Characterization of Silicone Liquid Core/Polymer Shell Microcapsules via Internal Phase Separation

    DEFF Research Database (Denmark)

    Gonzalez, Lidia; Kostrzewska, Malgorzata; Ma, Baoguang

    2014-01-01

    Microcapsules with a silicone liquid core surrounded by a polymeric shell were synthesisedthrough the controlled phase separation. The dispersed silicone phase consisted of the shellpolymer PMMA, a good solvent for the PMMA (dichloromethane, DCM) and a poor solvent(methylhydrosiloxane dimethylsil......Microcapsules with a silicone liquid core surrounded by a polymeric shell were synthesisedthrough the controlled phase separation. The dispersed silicone phase consisted of the shellpolymer PMMA, a good solvent for the PMMA (dichloromethane, DCM) and a poor solvent...

  19. The role of ultrasound in controlling the liquid-liquid phase separation and nucleation of vanillin polymorphs I and II

    Science.gov (United States)

    Parimaladevi, P.; Supriya, S.; Srinivasan, K.

    2018-02-01

    The influence of ultrasound on liquid-liquid phase separation (LLPS) and polymorphism of vanillin in aqueous solution has been investigated for the first time by varying the ultrasonic parameters such as power, pulse rate and insonation time at ambient condition. Results reveal that the application of ultrasound controls the impact of LLPS and accelerates the nucleation of vanillin within a short period at lower levels of ultrasonic process parameters, and also enhances the quality of the nucleated crystals. Moreover, the application of ultrasound induces the nucleation of rare and metastable polymorph of vanillin Form II in aqueous solution. But, at higher levels of power, pulse rate and insonation time, the rate of LLPS is found increased and the quality of the crystals becomes deteriorated. Morphology of the nucleated polymorphs were identified through optical microscopy and confirmed by optical goniometry. The internal structure and thermal stability of the grown stable Form I and metastable Form II of vanillin were confirmed through powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC) analyses. Further, results suggest that the ultrasound has profound effect in controlling the LLPS and nucleation of vanillin polymorphs in aqueous solution.

  20. Liquid-liquid phase separation in particles containing secondary organic material free of inorganic salts

    Science.gov (United States)

    Song, Mijung; Liu, Pengfei; Martin, Scot T.; Bertram, Allan K.

    2017-09-01

    Particles containing secondary organic material (SOM) are ubiquitous in the atmosphere and play a role in climate and air quality. Recently, research has shown that liquid-liquid phase separation (LLPS) occurs at high relative humidity (RH) (greater than ˜ 95 %) in α-pinene-derived SOM particles free of inorganic salts, while LLPS does not occur in isoprene-derived SOM particles free of inorganic salts. We expand on these findings by investigating LLPS at 290 ± 1 K in SOM particles free of inorganic salts produced from ozonolysis of β-caryophyllene, ozonolysis of limonene, and photo-oxidation of toluene. LLPS was observed at greater than ˜ 95 % RH in the biogenic SOM particles derived from β-caryophyllene and limonene while LLPS was not observed in the anthropogenic SOM particles derived from toluene. This work combined with the earlier work on LLPS in SOM particles free of inorganic salts suggests that the occurrence of LLPS in SOM particles free of inorganic salts is related to the oxygen-to-carbon elemental ratio (O : C) of the organic material. These results help explain the difference between the hygroscopic parameter κ of SOM particles measured above and below water saturation in the laboratory and field, and have implications for predicting the cloud condensation nucleation properties of SOM particles.

  1. Phase transformation and liquid density redistribution during solidification of Ni-based superalloy Inconel 718

    Directory of Open Access Journals (Sweden)

    Wang Ling

    2012-08-01

    Full Text Available The influences of chemical segregation and phase transformation on liquid density variation during solidification of Ni-based supperalloy Inconel 718 were investigated using SEM and EDS. It was found that significant segregation in liquid prompts high Nb phase to precipitate directly from liquid, which results in the redistribution of alloy elements and liquid density in their vicinity. The term “inter-precipitate liquid density” is therefore proposed and this concept should be applied to determine the solidification behavior of superalloy Inconel 718.

  2. Measuring of nonlinearity of dye doped liquid crystals using of self phase modulation effect

    International Nuclear Information System (INIS)

    Abedi, M.; Jafari, A.; Tajalli, H.

    2007-01-01

    Self phase modulation in dye doped liquid crystals has investigated and the nonlinearity of dye doped liquid crystals is measured by this effect. The Self phase modulation effect can be used for producing optical micro rings that have many applications in photonics and laser industries.

  3. Liquid Crystal Phases of Colloidal Platelets and their Use as Nanocomposite Templates

    NARCIS (Netherlands)

    Mourad, M.C.D.|info:eu-repo/dai/nl/304837563

    2009-01-01

    This thesis explores the gelation and liquid crystal phase behavior of colloidal dispersions of platelike particles as well as the use of such dispersions for the generation of nanocomposites. We report on the sol-gel, sol-glass and liquid crystal phase transitions of positively charged colloidal

  4. Stability of Transition-metal Carbides in Liquid Phase Reactions Relevant for Biomass-Based Conversion

    NARCIS (Netherlands)

    Souza Macêdo, L.; Stellwagen, D.R.; Teixeira da Silva, V.; Bitter, J.H.

    2015-01-01

    Transition-metal carbides have been employed for biobased conversions aiming to replace the rare noble metals. However, when reactions are in liquid phase, many authors have observed catalyst deactivation. The main routes of deactivation in liquid phase biobased conversions are coke deposition,

  5. Combining innovative technology demonstrations with dense nonaqueous phase liquids cleanup

    International Nuclear Information System (INIS)

    Hagood, M.C.; Koegler, K.J.; Rohay, V.J.; Trent, S.J.; Stein, S.L.; Brouns, T.M.; McCabe, G.H.; Tomich, S.

    1993-05-01

    Radioactively contaminated acidic aqueous wastes and organic liquids were discharged to the soil column at three disposal sites within the 200 West Area of the Hanford Site, Washington. As a result, a portion of the underlying groundwater is contaminated with carbon tetrachloride several orders of magnitude above the maximum contaminant level accepted for a drinking water supply. Treatability testing and cleanup actions have been initiated to remove the contamination from both the unsaturated soils to minimize further groundwater contamination and the groundwater itself. To expedite cleanup, innovative technologies for (1) drilling, (2) site characterization, (3) monitoring, (4) well field development, and (5) contaminant treatment are being demonstrated and subsequently used where possible to improve the rates and cost savings associated with the removal of carbon tetrachloride from the soils and groundwater

  6. Partial Discharge Phase Distribution Of Palm Oil As Insulating Liquid

    Directory of Open Access Journals (Sweden)

    Abdul Rajab

    2011-04-01

    Full Text Available Due to the low biodegradability level of mineral oil and its susceptibility to the fire, palm oil was proposed as alternative insulating liquid. This paper discusses partial discharge (PD in palm oil under sinusoidal voltages and the comparison with mineral oil. PD was generated using a needle-plane electrode configuration which is enable enhancing electric field at the needle tip. PD pulses were detected using RC detector and they were measured using a Computer-based partial discharge measurement system. The results showed that PD activities in both oils are similar. The PD was initiated at the negative polarity of applied voltage. The discharges took place in both polarity’s of applied voltage with PD number was higher at negative one. Several discharges phenomena showed the presence of space charge which changed electric field and governed PD activities besides the main field introduced by voltage application.

  7. Visualization of velocity field and phase distribution in gas-liquid two-phase flow by NMR imaging

    International Nuclear Information System (INIS)

    Matsui, G.; Monji, H.; Obata, J.

    2004-01-01

    NMR imaging has been applied in the field of fluid mechanics, mainly single phase flow, to visualize the instantaneous flow velocity field. In the present study, NMR imaging was used to visualize simultaneously both the instantaneous phase structure and velocity field of gas-liquid two-phase flow. Two methods of NMR imaging were applied. One is useful to visualize both the one component of liquid velocity and the phase distribution. This method was applied to horizontal two-phase flow and a bubble rising in stagnant oil. It was successful in obtaining some pictures of velocity field and phase distribution on the cross section of the pipe. The other is used to visualize a two-dimensional velocity field. This method was applied to a bubble rising in a stagnant water. The velocity field was visualized after and before the passage of a bubble at the measuring cross section. Furthermore, the distribution of liquid velocity was obtained. (author)

  8. Phase Behavior of Mixtures of Ionic Liquids and Organic Solvents

    DEFF Research Database (Denmark)

    Abildskov, Jens; Ellegaard, Martin Dela; O’Connell, J.P.

    2010-01-01

    A corresponding-states form of the generalized van der Waals equation, previously developed for mixtures of an ionic liquid and a supercritical solute, is here extended to mixtures including an ionic liquid and a solvent (water or organic). Group contributions to characteristic parameters...... are implemented, leading to an entirely predictive method for densities of mixed compressed ionic liquids. Quantitative agreement with experimental data is obtained over wide ranges of conditions. Previously, the method has been applied to solubilities of sparingly soluble gases in ionic liquids and in organic...... solvents. Here we show results for heavier and more-than-sparingly solutes such as carbon dioxide and propane in ionic liquids....

  9. Numerical simulation for gas-liquid two-phase flow in pipe networks

    International Nuclear Information System (INIS)

    Li Xiaoyan; Kuang Bo; Zhou Guoliang; Xu Jijun

    1998-01-01

    The complex pipe network characters can not directly presented in single phase flow, gas-liquid two phase flow pressure drop and void rate change model. Apply fluid network theory and computer numerical simulation technology to phase flow pipe networks carried out simulate and compute. Simulate result shows that flow resistance distribution is non-linear in two phase pipe network

  10. Vapour phase motion in cryogenic systems containing superheated and subcooled liquids

    Science.gov (United States)

    Kirichenko, Yu. A.; Chernyakov, P. S.; Seregin, V. E.

    The development of vent pipelines, and venting storage tanks for cryogenic liquids requires the knowledge of the law of motion as well as regularities of vapour content variation in the liquid and heat dissipation by the vapour phase. This is a theoretical study of the effect of superheating (subcooling) of the liquid, relative acceleration and reduced pressure upon the size and velocity of noninteracting vapour bubbles, moving in the liquid, and upon their resistance and heat transfer coefficients.

  11. Charge Transport and Phase Behavior of Imidazolium-Based Ionic Liquid Crystals from Fully Atomistic Simulations.

    Science.gov (United States)

    Quevillon, Michael J; Whitmer, Jonathan K

    2018-01-02

    Ionic liquid crystals occupy an intriguing middle ground between room-temperature ionic liquids and mesostructured liquid crystals. Here, we examine a non-polarizable, fully atomistic model of the 1-alkyl-3-methylimidazolium nitrate family using molecular dynamics in the constant pressure-constant temperature ensemble. These materials exhibit a distinct "smectic" liquid phase, characterized by layers formed by the molecules, which separate the ionic and aliphatic moieties. In particular, we discuss the implications this layering may have for electrolyte applications.

  12. Liquid phase deposition of silica: Thin films, colloids and fullerenes

    Science.gov (United States)

    Whitsitt, Elizabeth A.

    Little research has been done to explore liquid phase deposition (LPD) of silica on non-planar substrates. This thesis proves that the seeded growth of silica colloids from fullerene and surfactant micelles is possible via LPD, as is the coating of individual single walled carbon nanotubes (SWNTs) and carbon fibers. Working on the premise that a molecular growth mechanism (versus colloidal/gel deposition) is valid for LPD, nanostructured substrates and specific chemical functional groups should act as "seeds," or templates, for silica growth. Seeded growth is confirmed by reactions of the growth solution with a range of surfactants and with materials with distinctive surface moieties. LPD promises lower production costs and environmental impact as compared to present methods of coating technology, because it is an inherently simple process, using low temperatures and inexpensive air-stable reactants. Silica is ubiquitous in materials science. Its applications range from thixotropic additives for paint to gate dielectrics in the semiconductor industry. Nano-structured coatings and thin films are integral in today's electronics industry and will become more vital as the size of electronics shrinks. With the incorporation of nanoparticles in future devices, the ability to deposit quality coatings with finely tuned properties becomes paramount. The methods developed herein have applications in fabricating insulators for use in the future molecular scale electronics industry. Additionally, these silica nanoparticles have applications as templates for use in photonics and fuel cell membrane production and lend strength and durability to composites.

  13. Restrictive liquid-phase diffusion and reaction in bidispersed catalysts

    International Nuclear Information System (INIS)

    Lee, S.Y.; Seader, J.D.; Tsai, C.H.; Massoth, F.E.

    1991-01-01

    In this paper, the effect of bidispersed pore-size distribution on liquid-phase diffusion and reaction in NiMo/Al 2 O 3 catalysts is investigated by applying two bidispersed-pore-structure models, the random-pore model and a globular-structure model, to extensive experimental data, which were obtained from sorptive diffusion measurements at ambient conditions and catalytic reaction rate measurements on nitrogen-containing compounds. Transport of the molecules in the catalysts was found to be controlled by micropore diffusion, in accordance with the random-pore model, rather than macropore diffusion as predicted by the globular-structure model. A qualitative criterion for micropore-diffusion control is proposed: relatively small macroporosity and high catalyst pellet density. Since most hydrotreating catalysts have high density, diffusion in these types of catalysts may be controlled by micropore diffusion. Accordingly, it is believed in this case that increasing the size of micropores may be more effective to reduce intraparticle diffusion resistance than incorporating macropores alone

  14. Thermodynamic and kinetic simulation of transient liquid-phase bonding

    Science.gov (United States)

    Lindner, Brad

    The use of numeric computational methods for the simulation of materials systems is becoming more prevalent and an understanding of these tools may soon be a necessity for Materials Engineers and Scientists. The applicability of numerical simulation methods to transient liquid-phase (TLP) bonding is evaluated using a type 316L/MBF-51 material system. The comparisons involve the calculation of bulk diffusivities, tracking of interface positions during dissolution, widening, and isothermal solidification stages, as well as comparison of elemental composition profiles. The simulations were performed with Thermo-Calc and DICTRA software packages and the experiments with differential scanning calorimetry (DSC), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and optical microscopic methods. Analytical methods are also discussed to enhance understanding. The results of the investigation show that while general agreement between simulations and experiments can be obtained, assumptions made with the simulation programs may cause difficulty in interpretation of the results unless the user has sufficient, mathematical, thermodynamic, kinetic, and simulation background.

  15. Natural Length Scales Shape Liquid Phase Continuity in Unsaturated Flows

    Science.gov (United States)

    Assouline, S.; Lehmann, P. G.; Or, D.

    2015-12-01

    Unsaturated flows supporting soil evaporation and internal drainage play an important role in various hydrologic and climatic processes manifested at a wide range of scales. We study inherent natural length scales that govern these flow processes and constrain the spatial range of their representation by continuum models. These inherent length scales reflect interactions between intrinsic porous medium properties that affect liquid phase continuity, and the interplay among forces that drive and resist unsaturated flow. We have defined an intrinsic length scale for hydraulic continuity based on pore size distribution that controls soil evaporation dynamics (i.e., stage 1 to stage 2 transition). This simple metric may be used to delineate upper bounds for regional evaporative losses or the depth of soil-atmosphere interactions (in the absence of plants). A similar length scale governs the dynamics of internal redistribution towards attainment of field capacity, again through its effect on hydraulic continuity in the draining porous medium. The study provides a framework for guiding numerical and mathematical models for capillary flows across different scales considering the necessary conditions for coexistence of stationarity (REV), hydraulic continuity and intrinsic capillary gradients.

  16. Overview of reactors for liquid phase Fischer-Tropsch synthesis

    International Nuclear Information System (INIS)

    Davis, Burtron H.

    2002-01-01

    The following overview is divided roughly into three sections. The first section covers the period from the late 1920s when the first liquid phase synthesis was first conducted until about 1960 when the interest in Fischer-Tropsch synthesis (FTS) declined because of the renewed view of an abundance of petroleum at a low price. The second period includes the activity that resulted from the oil shortage due to the Arab embargo in 1972 and covers from about 1960 to 1985 when the period of gloomy projections for rapidly increasing prices for crude had faded away. The third section covers the period from when the interest in FTS was no longer driven by the projected supply and/or price of petroleum but by the desire to monetize stranded natural gas and/or terminate flaring the gas associated with petroleum production and other environmental concerns (1985 to date). These sections are followed by a brief overview of the current status of the scientific and engineering understanding of slurry bubble column reactors

  17. Low level liquid scintillation analysis for environmental and biomedical quantitation

    International Nuclear Information System (INIS)

    Kessler, M.J.

    1991-01-01

    Over the past five years low level liquid scintillation counting has become increasing popular because of the large number of applications which can be performed using this technique. These applications include environmental monitoring ( 3 H, 90 Sr/ 90 Y, etc.), radiocarbon dating (for age determination to 50,000 years), food adulteration studies (alcohol and beverage industries), radon monitoring (air/water), nuclear power plant monitoring (low level 3 H) and metabolism studies (pharmaceutical research). These applications can be performed with either a dedicated low level LSC or using a standard liquid scintillation counter in conjunction with the new technique of time-resolved LSC (TR-LSC). This technique when used on a standard LSC reduces the instrument background without substantially effecting the background, thus increasing the performance (E 2 /B) of the LSC. Data will be presented for each of the applications mentioned above, comparing the standard LSC and the new TR-LSC techniques. The optimization of the samples for each of these applications will be explored in detail with experimental results. In conclusion, by using the TR-LSC technique in conjunction with a standard LSC the performance of the standard LSC can be increased substantially without dedicating the LSC to doing only low level samples

  18. Extraction Equilibrium of Acrylic Acid by Aqueous Two-Phase Systems Using Hydrophilic Ionic Liquids

    International Nuclear Information System (INIS)

    Lee, Yong Hwa; Lee, Woo Youn; Kim, Ki-Sub; Hong, Yeon Ki

    2014-01-01

    As an effective method for extraction of acrylic acid, aqueous two-phase systems based on morpholinium ionic liquids were used in this study. Effects of the alkyl chain length of cation in morpholinium ionic liquids on phase diagram and extraction efficiencies were investigated. Experimental results show that aqueous two phase systems can be formed by adding appropriate amount of morpholinium ionic liquids to aqueous K 2 HPO 4 solutions. It can be found that the ability of morpholinium ionic liquids for phase separation followed the order [HMMor][Br]>[OMMor][Br]>[BMMor][Br]>[EMMor][Br]. There was little difference between binodal curves of imidazolium ionic liquids and those of morpholinium ionic liquids. 50-90% of the extraction efficiency was observed for acrylic acid by aqueous two phase extraction of acrylic acid with morpholinium ionic liquids. It can be concluded that morpholinium ionic liquids/K 2 HPO 4 were effective for aqueous two phases extraction of acrylic acid comparing to imidazolium ionic liquids/K 2 HPO 4 systems because of their lower cost

  19. Visualization and measurement of liquid velocity field of gas-liquid metal two-phase flow using neutron radiography

    International Nuclear Information System (INIS)

    Saito, Yasushi; Suzuki, Tohru; Matsubayashi, Masahito

    2000-01-01

    In a core melt accident of a fast breeder reactor, a possibility of re-criticality is anticipated in the molten fuel-steel mixture pool. One of the mechanisms to suppress the re-criticality is the boiling of steel in the molten fuel-steel mixture pool because of the negative void reactivity effect. To evaluate the reactivity change due to boiling, it is necessary to know the characteristics of gas-liquid two-phase flow in the molten fuel-steel mixture pool. For this purpose, boiling bubbles in a molten fuel-steel mixture pool were simulated by adiabatic gas bubbles in a liquid metal pool to study the basic characteristics of gas-liquid metal two-phase mixture. Visualization of the two-phase mixture and measurements of liquid phase velocity and void fraction were conducted by using neutron radiography and image processing techniques. From these measurements, the basic characteristics of gas-liquid metal two-phase mixture were clarified. (author)

  20. Phase-I Trigger Readout Electronics Upgrade for the ATLAS Liquid-Argon Calorimeters

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00452211; The ATLAS collaboration

    2017-01-01

    The upgrade of the Large Hadron Collider (LHC) scheduled for the Long Shut-down period of 2019-2020 (LS2), referred to as Phase-I upgrade, will increase the instantaneous luminosity to about three times the design value. Since the current ATLAS trigger system does not allow sucient increase of the trigger rate, an improvement of the trigger system is required. The Liquid Argon (LAr) Calorimeter read-out will therefore be modi ed to use digital trigger signals with a higher spatial granularity in order to improve the identi cation effciencies of electrons, photons, tau, jets and missing energy, at high background rejection rates at the Level-1 trigger.

  1. On the abundance and general nature of the liquid-liquid phase transition in molecular systems

    International Nuclear Information System (INIS)

    Kurita, Rei; Tanaka, Hajime

    2005-01-01

    Even a single-component liquid may have more than two kinds of isotropic liquid states. The transition between these different states is called a liquid-liquid transition (LLT). An LLT has been considered to be a rather rare phenomenon, in particular for molecular liquids. Very recently, however, we found an LLT in triphenyl phosphite, which may be the first experimental observation of an LLT for molecular liquids. Here we report convincing evidence of the second example of LLT for another molecular liquid, n-butanol. Despite large differences in the chemical structure and the molecular shape between triphenyl phosphite and n-butanol, the basic features of the transformation kinetics are strikingly similar. This suggests that an LLT may not be a rare phenomenon restricted to specific liquids, but may exist in various molecular liquids, which have a tendency to form long-lived locally favoured structures due to anisotropic interactions (e.g., hydrogen bonding). (letter to the editor)

  2. Expert system for liquid low-level waste management

    International Nuclear Information System (INIS)

    Ferrada, J.J.

    1992-01-01

    An expert system prototype has been developed to support system analysis activities at the Oak Ridge National Laboratory (ORNL) for waste management tasks. This expert system will aid in prioritizing radioactive waste streams for treatment and disposal by evaluating the severity and treatability of the problem as well as the final waste form. The objectives of the expert system development included: (1) collecting information on process treatment technologies for liquid low-level waste (LLLW) that can be incorporated in the knowledge base of the expert system, and (2) producing a prototype that suggests processes and disposal technologies for the ORNL LLLW system. The concept under which the expert system has been designed is integration of knowledge. There are many sources of knowledge (data bases, text files, simulation programs, etc.) that an expert would regularly consult in order to solve a problem of liquid waste management. The expert would normally know how to extract the information from these different sources of knowledge. The general scope of this project would be to include as much pertinent information as possible within the boundaries of the expert system. As a result, the user, who may not be an expert in every aspect of liquid waste management, may be able to apply the content of the information to a specific waste problem. This paper gives the methodological steps to develop the expert system under this general framework

  3. Flow proportional sampling of low level liquid effluent

    International Nuclear Information System (INIS)

    Colley, D.; Jenkins, R.

    1989-01-01

    A flow proportional sampler for use on low level radioactive liquid effluent has been developed for installation on all CEGB nuclear power stations. The sampler, operates by drawing effluent continuously from the main effluent pipeline, through a sampler loop and returning it to the pipeline. The effluent in this loop is sampled by taking small, frequent aliquots using a linear acting shuttle valve. The frequency of operation of this valve is controlled by a flowmeter installed in the effluent line; sampling rate being directly proportional to effluent flowrate. (author)

  4. Crosslinked polymeric ionic liquids as solid-phase microextraction sorbent coatings for high performance liquid chromatography.

    Science.gov (United States)

    Yu, Honglian; Merib, Josias; Anderson, Jared L

    2016-03-18

    Neat crosslinked polymeric ionic liquid (PIL) sorbent coatings for solid-phase microextraction (SPME) compatible with high-performance liquid chromatography (HPLC) are reported for the first time. Six structurally different PILs were crosslinked to nitinol supports and applied for the determination of select pharmaceutical drugs, phenolics, and insecticides. Sampling conditions including sample solution pH, extraction time, desorption solvent, desorption time, and desorption solvent volume were optimized using design of experiment (DOE). The developed PIL sorbent coatings were stable when performing extractions under acidic pH and remained intact in various organic desorption solvents (i.e., methanol, acetonitrile, acetone). The PIL-based sorbent coating polymerized from the IL monomer 1-vinyl-3-(10-hydroxydecyl) imidazolium chloride [VC10OHIM][Cl] and IL crosslinker 1,12-di(3-vinylbenzylimidazolium) dodecane dichloride [(VBIM)2C12] 2[Cl] exhibited superior extraction performance compared to the other studied PILs. The extraction efficiency of pharmaceutical drugs and phenolics increased when the film thickness of the PIL-based sorbent coating was increased while many insecticides were largely unaffected. Satisfactory analytical performance was obtained with limits of detection (LODs) ranging from 0.2 to 2 μg L(-1) for the target analytes. The accuracy of the analytical method was examined by studying the relative recovery of analytes in real water samples, including tap water and lake water, with recoveries varying from 50.2% to 115.9% and from 48.8% to 116.6%, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Design and construction of the low-level liquid waste treatment system

    International Nuclear Information System (INIS)

    Baker, M.N.; Mateer, W.E.; Metzler, G.H.; Reeves, S.R.; Rickettson, D.J.

    1989-03-01

    This report describes the design and construction of the Low-Level Liquid Waste Treatment System (LWTS). The LWTS is part of a system that will prepare High-Level Radioactive Waste for solidification in glass. This preparation includes removal of water and salts from the stored waste. The topics addressed are: the design objective to reuse the Process Building to contain LWTS, the special considerations that arise when building a new system inside a decontaminated facility, interface to existing plant systems, phased construction, and construction testing. 8 refs., 24 figs

  6. A Liquid-Liquid Thermoelectric Heat Exchanger as a Heat Pump for Testing Phase Change Material Heat Exchangers

    Science.gov (United States)

    Sheth, Rubik B.; Makinen, Janice; Le, Hung V.

    2016-01-01

    The primary objective of the Phase Change HX payload on the International Space Station (ISS) is to test and demonstrate the viability and performance of Phase Change Material Heat Exchangers (PCM HX). The system was required to pump a working fluid through a PCM HX to promote the phase change material to freeze and thaw as expected on Orion's Multipurpose Crew Vehicle. Due to limitations on ISS's Internal Thermal Control System, a heat pump was needed on the Phase Change HX payload to help with reducing the working fluid's temperature to below 0degC (32degF). This paper will review the design and development of a TEC based liquid-liquid heat exchanger as a way to vary to fluid temperature for the freeze and thaw phase of the PCM HX. Specifically, the paper will review the design of custom coldplates and sizing for the required heat removal of the HX.

  7. The status of research on CFD-PBM simulation of liquid-liquid two-phase flow in extraction columns

    International Nuclear Information System (INIS)

    Li Shaowei; Jing Shan; Wu Qiulin; Zhang Qi

    2012-01-01

    Computational fluid dynamics (CFD) simulation has gained more and more interest in the chemical engineering researchers and is becoming a useful tool for the chemical engineering research. The research on liquid-liquid two-phase flow CFD simulation in extraction columns is now in its initial stage. There is much work to do for the developing of this research field. The purpose of this article is to review the CFD simulation methods for two-phase flow in extraction column. The population balance model (PBM) is detailedly described in this article because it is the main method used in the two-phase flow CFD simulation currently. Then some examples for the two-phase flow simulation in extraction columns are briefly introduced. The strategy for the research on CFD simulation of two-phase flow in extraction columns is suggested at last. (authors)

  8. Improved Ionic Liquids as Space Lubricants, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Ionic liquids are candidate lubricant materials. However for application in low temperature space mechanisms their lubrication performance needs to be enhanced. UES...

  9. Non-conventional solvents in liquid phase microextraction and aqueous biphasic systems.

    Science.gov (United States)

    An, Jiwoo; Trujillo-Rodríguez, María J; Pino, Verónica; Anderson, Jared L

    2017-06-02

    The development of rapid, convenient, and high throughput sample preparation approaches such as liquid phase microextraction techniques have been continuously developed over the last decade. More recently, significant attention has been given to the replacement of conventional organic solvents used in liquid phase microextraction techniques in order to reduce toxic waste and to improve selectivity and/or extraction efficiency. With these objectives, non-conventional solvents have been explored in liquid phase microextraction and aqueous biphasic systems. The utilized non-conventional solvents include ionic liquids, magnetic ionic liquids, and deep eutectic solvents. They have been widely used as extraction solvents or additives in various liquid phase microextraction modes including dispersive liquid-liquid microextraction, single-drop microextraction, hollow fiber-liquid phase microextraction, as well as in aqueous biphasic systems. This review provides an overview into the use of non-conventional solvents in these microextraction techniques in the past 5 years (2012-2016). Analytical applications of the techniques are also discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Porous metallosilicates for heterogeneous, liquid-phase catalysis: perspectives and pertaining challenges

    Science.gov (United States)

    Hammond, Ceri; Padovan, Daniele; Tarantino, Giulia

    2018-02-01

    Porous silicates containing dilute amounts of tri-, tetra- and penta-valent metal sites, such as TS-1, Sn-β and Fe-ZSM-5, have recently emerged as state of the art catalysts for a variety of sustainable chemical transformations. In contrast with their aluminosilicate cousins, which are widely employed throughout the refinery industry for gas-phase catalytic transformations, such metallosilicates have exhibited unprecedented levels of performance for a variety of liquid-phase catalytic processes, including the conversion of biomass to chemicals, and sustainable oxidation technologies with H2O2. However, despite their unique levels of performance for these new types of chemical transformations, increased utilization of these promising materials is complicated by several factors. For example, their utilization in a liquid, and often polar, medium hinders process intensification (scale-up, catalyst deactivation). Moreover, such materials do not generally exhibit the active-site homogeneity of conventional aluminosilicates, and they typically possess a wide variety of active-site ensembles, only some of which may be directly involved in the catalytic chemistry of interest. Consequently, mechanistic understanding of these catalysts remains relatively low, and competitive reactions are commonly observed. Accordingly, unified approaches towards developing more active, selective and stable porous metallosilicates have not yet been achieved. Drawing on some of the most recent literature in the field, the purpose of this mini review is both to highlight the breakthroughs made with regard to the use of porous metallosilicates as heterogeneous catalysts for liquid-phase processing, and to highlight the pertaining challenges that we, and others, aim to overcome during the forthcoming years.

  11. Effect of geometric parameters of liquid-gas separator units on phase separation performance

    Energy Technology Data Exchange (ETDEWEB)

    Mo, Songping; Chen, Xueqing; Chen, Ying [Guangdong University of Technology, Seoul (China); Yang, Zhen [Tsinghua University, Beijing (China)

    2015-07-15

    Five liquid-gas separator units were designed and constructed based on a new concept of a validated high-performance condenser. Each separator unit consists of two united T-junctions and an apertured baffle. The separator units have different header diameters or different baffles with different diameters of the liquid-gas separation hole. The phase separation characteristics of the units were investigated at inlet air superficial velocities from 1.0m/s to 33.0m/s and water superficial velocities from 0.0015 m/s to 0..50 m/s. The experimental results showed that the liquid height, liquid flow rate through the separation hole, and liquid separation efficiency increased with increased header diameter and decreased diameter of the separation hole. The geometric structures of the separator units affected the phase separation characteristics by influencing the liquid height in the header and the liquid flow rate through the separation hole.

  12. Sensitive determination of nitrophenol isomers by reverse-phase high-performance liquid chromatography in conjunction with liquid-liquid extraction

    Science.gov (United States)

    A method for the highly sensitive determination of 2-, 3- and 4- nitrophenols was developed using reverse-phase high-performance liquid chromatography (RP-HPLC) with a UV photodiode array detector. Using a reverse-phase column and 40% aqueous acetonitrile as an eluent (i.e. isocratic elution), the i...

  13. Cryogenic Liquid Level-Sensing using Fiber-Optic Strain Sensor (FOSS) Technology Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Armstrong innovators have developed a highly accurate method for measuring liquid levels using optical fibers. Unlike liquid level gauges that rely on discrete...

  14. Measurement of liquid level in a natural circulation circuit using an ultrasonic technique

    International Nuclear Information System (INIS)

    Barbosa, Amanda Cardozo; Su, Jian

    2017-01-01

    The measurement by an ultrasonic technique of the water level in the expansion tank of the Natural Circulation Circuit (NCC) of the Experimental Thermo-Hydraulic Laboratory of the Institute of Nuclear Engineering is presented. In the single-phase NCC operation the water level in the expansion tank is stable. However, during the two-phase operation, oscillations occur in the water level due to temperature and vacuum fraction variations. Thus, the development of a technique that allows the measurement of these oscillations, will allow an estimation of the variation of the vacuum fraction of the circuit over time. The experimental set - up was performed on a test bench, using an ultrasonic transducer. The ultrasonic technique used is pulse-echo, in which the same transducer is the transmitter and receiver of the signal. The transducer-shoe assembly is part of an ultrasonic system consisting of an ultrasonic signal generating plate, transducers and a computer (PC) with a program in LabView to control the system. The program is able to calculate the transit time that the ultrasonic signals take to cross the tank base wall, the layer (level) of liquid and return to the transducer. Knowing the speed of the ultrasound in the wall and in the liquid it is possible to calculate the thickness of the wall and the height of the liquid. Measurements were made by filling the tank with a known volume of water and under varying temperature conditions, from room temperature to 90 deg C. The liquid heights are determined and the volume of water calculated by measuring the temperature with a digital thermometer. The volumes measured were highly accurate when compared to the known volumes

  15. Thermodynamic modeling of liquid–liquid phase change solvents for CO2 capture

    DEFF Research Database (Denmark)

    Waseem Arshad, Muhammad; von Solms, Nicolas; Thomsen, Kaj

    2016-01-01

    A thermodynamic model based on Extended UNIQUAC framework has been developed in this work for the de-mixing liquid–liquid phase change solvents, DEEA (2-(diethylamino)ethanol) and MAPA (3-(methylamino)propylamine). Parameter estimation was performed for two ternary systems, H2O-DEEA-CO2 and H2O......-MAPA-CO2, and a quaternary system, H2O-DEEA-MAPA-CO2 (phase change system), by using different types of experimental data (equilibrium and thermal) consisting of pure amine vapor pressure, vapor-liquid equilibrium, solid-liquid equilibrium, liquid–liquid equilibrium, excess enthalpy, and heat of absorption...

  16. Balance of liquid-phase turbulence kinetic energy equation for bubble-train flow

    International Nuclear Information System (INIS)

    Ilic, Milica; Woerner, Martin; Cacuci, Dan Gabriel

    2004-01-01

    In this paper the investigation of bubble-induced turbulence using direct numerical simulation (DNS) of bubbly two-phase flow is reported. DNS computations are performed for a bubble-driven liquid motion induced by a regular train of ellipsoidal bubbles rising through an initially stagnant liquid within a plane vertical channel. DNS data are used to evaluate balance terms in the balance equation for the liquid phase turbulence kinetic energy. The evaluation comprises single-phase-like terms (diffusion, dissipation and production) as well as the interfacial term. Special emphasis is placed on the procedure for evaluation of interfacial quantities. Quantitative analysis of the balance equation for the liquid phase turbulence kinetic energy shows the importance of the interfacial term which is the only source term. The DNS results are further used to validate closure assumptions employed in modelling of the liquid phase turbulence kinetic energy transport in gas-liquid bubbly flows. In this context, the performance of respective closure relations in the transport equation for liquid turbulence kinetic energy within the two-phase k-ε and the two-phase k-l model is evaluated. (author)

  17. A mass conserving level set method for detailed numerical simulation of liquid atomization

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Kun; Shao, Changxiao [State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027 (China); Yang, Yue [State Key Laboratory of Turbulence and Complex Systems, Peking University, Beijing 100871 (China); Fan, Jianren, E-mail: fanjr@zju.edu.cn [State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027 (China)

    2015-10-01

    An improved mass conserving level set method for detailed numerical simulations of liquid atomization is developed to address the issue of mass loss in the existing level set method. This method introduces a mass remedy procedure based on the local curvature at the interface, and in principle, can ensure the absolute mass conservation of the liquid phase in the computational domain. Three benchmark cases, including Zalesak's disk, a drop deforming in a vortex field, and the binary drop head-on collision, are simulated to validate the present method, and the excellent agreement with exact solutions or experimental results is achieved. It is shown that the present method is able to capture the complex interface with second-order accuracy and negligible additional computational cost. The present method is then applied to study more complex flows, such as a drop impacting on a liquid film and the swirling liquid sheet atomization, which again, demonstrates the advantages of mass conservation and the capability to represent the interface accurately.

  18. Dissolved organic carbon enhances the mass transfer of hydrophobic organic compounds from Nonaqueous Phase Liquids (NAPLs) into the aqueous phase

    NARCIS (Netherlands)

    Smith, K.E.C.; Thullner, M.; Wick, L.Y.; Harms, H.

    2011-01-01

    The hypothesis that dissolved organic carbon (DOC) enhances the mass transfer of hydrophobic organic compounds from nonaqueous phase liquids (NAPLs) into the aqueous phase above that attributable to dissolved molecular diffusion alone was tested. In controlled experiments, mass transfer rates of

  19. The method for simultaneous extraction and back extraction in liquid three-phase system and equipment for simultaneous extraction and back extraction in liquid three-phase system

    International Nuclear Information System (INIS)

    Palyska, W.; Chmielewski, A.G.

    1992-01-01

    The method for simultaneous extraction and back extraction in liquid three-phase system has been worked out. The equipment designed for that process has been also subject of the patent. The interesting component is extracted first to intermediate phase consists of magnetic solvent keeping two extracting phases separately. The intermediate magnetic liquid has been kept in its position using a stable magnet maintained on the surface of the extraction vessel. Then the component pass from intermediate phase to the third phase as a result of back extraction. Mixing in the extraction and back extraction zones is organized by means of rotating shaft going along the whole apparatus. The extraction and back extraction processes occur simultaneously as a result of continuous flow of solvent in their zones. The single extraction back extraction facilities can be joined in larger batteries. 3 figs

  20. Comparison of cryopreserved human sperm in vapor and liquid phases of liquid nitrogen: effect on motility parameters, morphology, and sperm function.

    Science.gov (United States)

    Punyatanasakchai, Piyaphan; Sophonsritsuk, Areephan; Weerakiet, Sawaek; Wansumrit, Surapee; Chompurat, Deonthip

    2008-11-01

    To compare the effects of cryopreserved sperm in vapor and liquid phases of liquid nitrogen on sperm motility, morphology, and sperm function. Experimental study. Andrology laboratory at Ramathibodi Hospital, Thailand. Thirty-eight semen samples with normal motility and sperm count were collected from 38 men who were either patients of an infertility clinic or had donated sperm for research. Each semen sample was divided into two aliquots. Samples were frozen with static-phase vapor cooling. One aliquot was plunged into liquid nitrogen (-196 degrees C), and the other was stored in vapor-phase nitrogen (-179 degrees C) for 3 days. Thawing was performed at room temperature. Motility was determined by using computer-assisted semen analysis, sperm morphology was determined by using eosin-methylene blue staining, and sperm function was determined by using a hemizona binding test. Most of the motility parameters of sperm stored in the vapor phase were not significantly different from those stored in the liquid phase of liquid nitrogen, except in amplitude of lateral head displacement. The percentages of normal sperm morphology in both vapor and liquid phases also were not significantly different. There was no significant difference in the number of bound sperm in hemizona between sperm cryopreserved in both vapor and liquid phases of liquid nitrogen. Cryopreservation of human sperm in a vapor phase of liquid nitrogen was comparable to cryopreservation in a liquid phase of liquid nitrogen.

  1. Numerical simulation of gas-liquid two-phase flow and convective heat transfer in a micro tube

    International Nuclear Information System (INIS)

    Fukagata, Koji; Kasagi, Nobuhide; Ua-arayaporn, Poychat; Himeno, Takehiro

    2007-01-01

    Numerical simulation of an air and water two-phase flow in a 20 μm ID tube is carried out. A focus is laid upon the flow and heat transfer characteristics in bubble-train flows. An axisymmetric two-dimensional flow is assumed. The finite difference method is used to solve the governing equations, while the level set method is adopted for capturing the interface of gas and liquid. In each simulation, the mean pressure gradient and the wall heat flux are kept constant. The simulation is repeated under different conditions of pressure gradient and void fraction. The superficial Reynolds numbers of gas and liquid phases studied are 0.34-13 and 16-490, respectively, and the capillary number is 0.0087-0.27. Regardless of the flow conditions, the gas-phase velocity is found approximately 1.2 times higher than the liquid-phase velocity. This is in accordance with the Armand correlation valid for two-phase flows in macro-sized tubes. The two-phase friction coefficient is found to be scaled with the Reynolds number based on the effective viscosity of the Einstein type. The computed wall temperature distribution is qualitatively similar to that observed experimentally in a mini channel. The local Nusselt number beneath the bubble is found notably higher than that of single-phase flow

  2. Local gas- and liquid-phase measurements for air-water two-phase flows in a rectangular channel

    International Nuclear Information System (INIS)

    Zhou, X.; Sun, X.; Williams, M.; Fu, Y.; Liu, Y.

    2014-01-01

    Local gas- and liquid-phase measurements of various gas-liquid two-phase flows, including bubbly, cap-bubbly, slug, and churn-turbulent flows, were performed in an acrylic vertical channel with a rectangular cross section of 30 mm x 10 mm and height of 3.0 m. All the measurements were carried out at three measurement elevations along the flow channel, with z/D h = 9, 72, and 136, respectively, to study the flow development. The gas-phase velocity, void fraction, and bubble number frequency were measured using a double-sensor conductivity probe. A high-speed imaging system was utilized to perform the flow regime visualization and to provide additional quantitative information of the two-phase flow structure. An image processing scheme was developed to obtain the gas-phase velocity, void fraction, Sauter mean diameter, bubble number density, and interfacial area concentration. The liquid-phase velocity and turbulence measurements were conducted using a particle image velocimetry-planar laser-induced fluorescence (PIV-PLIF) system, which enables whole-field and high-resolution data acquisition. An optical phase separation method, which uses fluorescent particles and optical filtration technique, is adopted to extract the velocity information of the liquid phase. An image pre-processing scheme is imposed on the raw PIV images acquired to remove noises due to the presence of bubble residuals and optically distorted particles in the images captured by the PIV-PLIF system. Due to the better light access and less bubble distortion in the narrow rectangular channel, the PIV-PLIF system were able to perform reasonably well in flows of even higher void fractions as compared to the situations with circular pipe test sections. The flow conditions being studied covered various flow regime transitions, void fractions, and liquid-phase flow Reynolds numbers. The obtained experimental data can also be used to validate two-phase CFD results. (author)

  3. Influence of the temperature on the (liquid + liquid) phase equilibria of (water + 1-propanl + linalool or geraniol)

    International Nuclear Information System (INIS)

    Wan, Li; Li, Hengde; Huang, Cheng; Feng, Yuqing; Chu, Guoqiang; Zheng, Yuying; Tan, Wei; Qin, Yanlin; Sun, Dalei; Fang, Yanxiong

    2017-01-01

    Highlights: • Ternary LLEs containing linalool and geraniol are presented. • Distribution ratios of 1-propanol in the mixtures are examined. • Influence of the temperature on the LLE is studied. • The LLE data were correlated using the NRTL and UNIQUAC models. - Abstract: Linalool and geraniol are the primary components of rose oil, palmarosa oil, and citronella oil and many other essential oils, and two important compounds used in the flavour and fragrance, cosmetic or pharmaceutical industries. Phase equilibria (LLE, VLE, solubility, etc.) and related thermodynamic properties of a mixture are essential in the processes design and control of mass transfer process. In this work, experimental (liquid + liquid) equilibria data of the systems (water + 1-propanl + linalool) and (water + 1-propanl + geraniol) are presented. The (liquid + liquid) equilibria of both systems were determined with a tie-line method at T = (283.15, 298.15 and 313.15) K under atmospheric pressure. The well-known Hand, Bachman and Othmer–Tobias equations were used to test the reliability of the experimental values. The influence of the temperature on the (liquid + liquid) phase equilibria of the mixtures, the binodal curves and distribution ratios of 1-propanl are shown and discussed. Moreover, the NRTL and UNIQUAC models were applied to fit the data for both ternary systems. The interaction parameters obtained from both models successfully correlated the equilibrium compositions. Furthermore, the ternary systems could be represented using the binary parameters of the thermodynamic model with a function of temperature.

  4. Proceedings of the international seminar on chemistry and process engineering for high-level liquid waste solidification

    International Nuclear Information System (INIS)

    Odoj, R.; Merz, E.

    1981-06-01

    The proceedings record a very distinct phase of the chemistry and process engineering for high-level liquid waste solidification in the past years. The main purpose is to provide solutions which guarantee sufficient safe and economically acceptable measure causing no adverse consequence to man and his environment. (DG)

  5. Small Scroll Pump for Cryogenic Liquids, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation is a compact, reliable, light weight, electrically driven pump capable of pumping cryogenic liquids, based on scroll pump technology. This pump will...

  6. Droplet-Sizing Liquid Water Content Sensor, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Icing is one of the most significant hazards to aircraft. A sizing supercooled liquid water content (SSLWC) sonde is being developed to meet a directly related need...

  7. The phase diagram of molybdenum at extreme conditions and the role of local liquid structures

    Energy Technology Data Exchange (ETDEWEB)

    Ross, M

    2008-08-15

    Recent DAC measurements made of the Mo melting curve by the x-ray diffraction studies confirms that, up to at least 110 GPa (3300K) melting is directly from bcc to liquid, evidence that there is no basis for a speculated bcc-hcp or fcc transition. An examination of the Poisson Ratio, obtained from shock sound speed measurements, provides evidence that the 210 GPa (4100K) transition detected from shock experiments is a continuation of the bcc-liquid melting, but is from a bcc-to a solid-like mixed phase rather than to liquid. Calculations, modeled to include the free energy of liquid local structures, predict that the transition from the liquid to the mixed phase is near 150 GPa(3500K). The presence of local structures provides the simplest and most direct explanation for the Mo phase diagram, and the low melting slopes.

  8. Determination of phase transitions in a lyotropic liquid crystal by Positron Annihilation technique

    International Nuclear Information System (INIS)

    Castillo V, V.M.

    1994-01-01

    Positron annihilation technique was used to determine the phase transitions in a lyotropic liquid crystal, as a function of temperature. Seven different concentrations of the surfactant cetyldimethylethylammonium bromide, were studied. The liquid crystal studied consisted of a binary system, formed by the surfactant and water. Positron annihilation technique has a very high sensitivity toward changes in the microestructure, in condensed matter, this is useful in order to detect the temperatures at which phase transitions occur and the number of these, in a liquid crystalline system. Thus, phase transitions are related with changes occurred in the ortho-positronium parameters: lifetime (τ 3 ) and intensity of formation (I 3 ). Six different kinds of phases were detected in the system studied in a temperature range of 35 to 140 Centigrade degrees, those phases were: hexagonal, hexagonal-lamellae, lamellae, lamellae-cubic, nematic and anisotropic. Using optical microscopic the textures of these phases were assigned. (Author)

  9. Liquid entrainment and off-take from the two-phase mixture surface in a vessel

    International Nuclear Information System (INIS)

    Kim, Chang Hyun; No, Hee Cheon

    2003-01-01

    In order to determine the bleed capacity of the Safety Depressurization System (SDS) of Advanced Power Reactor 1400 (APR1400) in the case of Total Loss of Feed Water (TLOFW), we performed an experimental study of liquid entrainment and liquid off-take from the swelled two-phase mixture surface in a vessel. A total of 220 experimental data on the entrainment and off-take are obtained using a test vessel with a height of 2.0m and an inner diameter of 0.3m, and a top break with a diameter of 0.05m. Two-phase mixture levels are measured by an ultrasonic sensor within ±1.77% with respect to the visual level data. Droplet entrainment data are obtained with and without the top break and are compared with the existing pool entrainment data. The present droplet entrainment data have higher values than those of the existing pool entrainment due to (a) the pulling toward the break of the liquid deentrained on the top wall of the vessel and (b) gas acceleration in the vicinity of the break. In the present experiment, droplet entrainment, Efg, strongly depends upon jg/h and is proportional to the 7th power of jg/h in the same way as the off-take data. The empirical correlation for the onset of off-take is developed in terms of the Froude number (Frg) at the break and the non-dimensional inception height (hb/d). This correlation shows agreement with the present experimental data within ±15%. The present off-take quality data show agreement with Schrock's off-take quality correlation with the r.m.s. error of 15.8%

  10. Liquid-liquid phase equilibria for ternary systems of several polyethers with NaCl and H2O

    NARCIS (Netherlands)

    Milosevic, M.; Staal, K.J.J.; Schuur, Boelo; de Haan, A.B.

    2014-01-01

    Liquid–liquid extraction using polymers followed by induced phase separation is a potential energy reducing technology for water–salt separation. Ternary equilibrium data have been determined and reported for the (block co)poly ethers–sodium chloride–water systems at two different temperatures at

  11. Quasi-liquid layer theory based on the bulk first-order phase transition

    International Nuclear Information System (INIS)

    Ryzhkin, I. A.; Petrenko, V. F.

    2009-01-01

    The theory of the superionic phase transition (bulk first-order transition) proposed in [1] is used to explain the existence of a quasi-liquid layer at an ice surface below its melting point. An analytical expression is derived for the quasi-liquid layer thickness. Numerical estimates are made and compared with experiment. Distinction is made between the present model and other quasi-liquid layer theories

  12. Thermal property prediction and measurement of organic phase change materials in the liquid phase near the melting point

    International Nuclear Information System (INIS)

    O’Connor, William E.; Warzoha, Ronald; Weigand, Rebecca; Fleischer, Amy S.; Wemhoff, Aaron P.

    2014-01-01

    Highlights: • Liquid-phase thermal properties for five phase change materials were estimated. • Various liquid phase and phase transition thermal properties were measured. • The thermal diffusivity was found using a best path to prediction approach. • The thermal diffusivity predictive method shows 15% agreement for organic PCMs. - Abstract: Organic phase change materials (PCMs) are a popular choice for many thermal energy storage applications including solar energy, building envelope thermal barriers, and passive cooling of portable electronics. Since the extent of phase change during a heating or cooling process is dependent upon rapid thermal penetration into the PCM, accurate knowledge of the thermal diffusivity of the PCM in both solid and liquid phases is crucial. This study addresses the existing gaps in information for liquid-phase PCM properties by examining an approach that determines the best path to prediction (BPP) for the thermal diffusivity of both alkanes and unsaturated acids. Knowledge of the BPP will enable researchers to explore the influence of PCM molecular structure on bulk thermophysical properties, thereby allowing the fabrication of optimized PCMs. The BPP method determines which of the tens of thousands of combinations of 22 different available theoretical techniques provides best agreement with thermal diffusivity values based on reported or measured density, heat capacity, and thermal conductivity for each of five PCMs (heneicosane, tricosane, tetracosane, oleic acid, and linoleic acid) in the liquid phase near the melting point. Separate BPPs were calibrated for alkanes based on heneicosane and tetracosane, and for the unsaturated acids. The alkane and unsaturated acid BPPs were then tested on a variety of similar materials, showing agreement with reported/measured thermal diffusivity within ∼15% for all materials. The alkane BPP was then applied to find that increasing the length of alkane chains decreases the PCM thermal

  13. Fiber Optic Mass Flow Gauge for Liquid Cryogenic Fuel Facilities Monitoring and Control, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I proposal describes a fiber optic mass flow gauge that will aid in managing liquid hydrogen and oxygen fuel storage and transport. The increasing...

  14. Liquid-solid surface phase transformation of fluorinated fullerene on monolayer tungsten diselenide

    KAUST Repository

    Song, Zhibo; Wang, Qixing; Li, Ming-yang; Li, Lain-Jong; Zheng, Yu Jie; Wang, Zhuo; Lin, Tingting; Chi, Dongzhi; Ding, Zijing; Huang, Yu Li; Thye Shen Wee, Andrew

    2018-01-01

    interaction potential reveals that the repulsive dipole-dipole interaction induced by interfacial charge transfer and substrate-mediated interactions play important roles in stabilizing the liquid C60F48 phases. Theoretical calculations further suggest

  15. On the implications of aerosol liquid water and phase separation for organic aerosol mass

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset contains data presented in the figures of the paper "On the implications of aerosol liquid water and phase separation for organic aerosol mass"...

  16. Enhanced Membrane System for Recovery of Water from Gas-Liquid Mixtures, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Gas-Liquid separation is an acute microgravity problem. Existing devices use centrifugal motion on microporous membranes to separate the two phases. Centrifugal...

  17. Kinetic aspects of hollow fiber liquid-phase microextraction and electromembrane extraction

    DEFF Research Database (Denmark)

    Gjelstad, Astrid; Jensen, Henrik; Rasmussen, Knut Einar

    2012-01-01

    In this paper, extraction kinetics was investigated experimentally and theoretically in hollow fiber liquid-phase microextraction (HF-LPME) and electromembrane extraction (EME) with the basic drugs droperidol, haloperidol, nortriptyline, clomipramine, and clemastine as model analytes. In HF...

  18. Measurement of Liquid-Metal Two-Phase Flow with a Dynamic Neutron Radiography

    International Nuclear Information System (INIS)

    Cha, J. E.; Lim, I. C.; Kim, H. R.; Kim, C. M.; Nam, H. Y.; Saito, Y.

    2005-01-01

    The dynamic neutron radiography(DNR) has complementary characteristics to X-ray radiography and is suitable to visualization and measurement of a multi-phase flow research in a metallic duct and liquid metal flow. The flow-field information of liquid metal system is very important for the safety analysis of fast breeder reactor and the design of the spallation target of accelerator driven system. A DNR technique was applied to visualize the flow field in the gas-liquid metal two-phase flow with the HANARO-beam facility. The lead bismuth eutectic and the nitrogen gas were used to construct the two-phase flow field in the natural circulation U-channel. The two-phase flow images in the riser were taken at various combinations of the liquid flow and gas flow with high frame-rate neutron radiography at 1000 fps

  19. Investigating the Retention Mechanisms of Liquid Chromatography Using Solid-Phase Extraction Cartridges

    Science.gov (United States)

    O'Donnell, Mary E.; Musial, Beata A.; Bretz, Stacey Lowery; Danielson, Neil D.; Ca, Diep

    2009-01-01

    Liquid chromatography (LC) experiments for the undergraduate analytical laboratory course often illustrate the application of reversed-phase LC to solve a separation problem, but rarely compare LC retention mechanisms. In addition, a high-performance liquid chromatography instrument may be beyond what some small colleges can purchase. Solid-phase…

  20. Reduction of water consumption in bioethanol production from triticale by recycling the stillage liquid phase.

    Science.gov (United States)

    Gumienna, Małgorzata; Lasik, Małgorzata; Szambelan, Katarzyna; Czarnecki, Zbigniew

    2011-01-01

    The distillery stillage is a major and arduous byproduct generated during ethanol production in distilleries. The aim of this study was to evaluate the possibility of the stillage recirculation in the mashing process of triticale for non-byproducts production and reducing the fresh water consumption. The number of recirculation cycles which can be applied without disturbances in the ethanol fermentation process was investigated. Winter triticale BOGO and "Ethanol Red" Saccharomyces cerevisiae yeast were used in the experiments. The method of non-pressure cooking was used for gelatinizingthe triticale, commercial α-amylase SPEZYME ETHYL and glucoamylase FERMENZYME L-400 were applied for starch liquefaction and saccharification. The process was conducted at 30°C for 72 h, next after distillation the stillage was centrifuged and the liquid fraction was used instead of 75% of process water. Ethanol yield from triticale fermentations during 40 cycles ranged between 82% and 95% of theoretical yield preserving yeast vitality and quantity on the same level. The obtained distillates were characterized with enhanced volatile compounds (fusel oil, esters, aldehydes, methanol) as well as protein and potassium concentrations. The liquid part of stillage was proved that can be reused instead of water in bioethanol production from triticale, without disturbing the fermentation process. This investigated solution of distillery byproducts utilization (liquid phase of stillage) constitutes the way which could significantly decrease the bioethanol production costs by reducing the water consumption, as well as wastewater production.

  1. Experimental study on liquid velocity in upward and downward two-phase flows

    International Nuclear Information System (INIS)

    Sun, X.; Paranjape, S.; Kim, S.; Ozar, B.; Ishii, M.

    2003-01-01

    Local characteristics of the liquid phase in upward and downward air-water two-phase flows were experimentally investigated in a 50.8-mm inner-diameter round pipe. An integral Laser Doppler Anemometry (LDA) system was used to measure the axial liquid velocity and its fluctuations. No effect of the flow direction on the liquid velocity radial profile was observed in single-phase liquid benchmark experiments. Local multi-sensor conductivity probes were used to measure the radial profiles of the bubble velocity and the void fraction. The measurement results in the upward and downward two-phase flows are compared and discussed. The results in the downward flow demonstrated that the presence of the bubbles tended to flatten the liquid velocity radial profile, and the maximum liquid velocity could occur off the pipe centerline, in particular at relatively low flow rates. However, the maximum liquid velocity always occurred at the pipe center in the upward flow. Also, noticeable turbulence enhancement due to the bubbles in the two-phase flows was observed in the current experimental flow conditions. Furthermore, the distribution parameter and the void weighted area-averaged drift velocity were obtained based on the definitions

  2. Liquid phase oxidation via heterogeneous catalysis organic synthesis and industrial applications

    CERN Document Server

    Clerici, Mario G

    2013-01-01

    Sets the stage for environmentally friendly industrial organic syntheses From basic principles to new and emerging industrial applications, this book offers comprehensive coverage of heterogeneous liquid-phase selective oxidation catalysis. It fully examines the synthesis, characterization, and application of catalytic materials for environmentally friendly organic syntheses. Readers will find coverage of all the important classes of catalysts, with an emphasis on their stability and reusability. Liquid Phase Oxidation via Heterogeneous Catalysis features contributions from an internation

  3. Microstructural anomalies in a W-Ni alloy liquid phase sintered under microgravity conditions

    International Nuclear Information System (INIS)

    Liu, Y.; Iacocca, R.G.; Johnson, J.L.; German, R.M.; Kohara, Shiro

    1995-01-01

    The gravitational role in liquid phase sintering (LPS) is a problem of great interest in both materials science and engineering practice. Gravity-induced microstructural gradients in grain size, grain shape, and solid volume fraction have been well documented in liquid phase sintered tungsten heavy alloys and have been analyzed by a number of theoretical models. However, gravity may have many unknown effects on LPS, which can only be revealed by experiments conducted under microgravity conditions

  4. Evaluation of mercury in liquid waste processing facilities - Phase I report

    Energy Technology Data Exchange (ETDEWEB)

    Jain, V. [Savannah River Site (SRS), Aiken, SC (United States); Occhipinti, J. E. [Savannah River Site (SRS), Aiken, SC (United States); Shah, H. [Savannah River Site (SRS), Aiken, SC (United States); Wilmarth, W. R. [Savannah River Site (SRS), Aiken, SC (United States); Edwards, R. E. [Savannah River Site (SRS), Aiken, SC (United States)

    2015-07-01

    This report provides a summary of Phase I activities conducted to support an Integrated Evaluation of Mercury in Liquid Waste System (LWS) Processing Facilities. Phase I activities included a review and assessment of the liquid waste inventory and chemical processing behavior of mercury using a system by system review methodology approach. Gaps in understanding mercury behavior as well as action items from the structured reviews are being tracked. 64% of the gaps and actions have been resolved.

  5. Evaluation of Mercury in Liquid Waste Processing Facilities - Phase I Report

    Energy Technology Data Exchange (ETDEWEB)

    Jain, V. [Savannah River Site (SRS), Aiken, SC (United States); Occhipinti, J. [Savannah River Site (SRS), Aiken, SC (United States); Shah, H. [Savannah River Site (SRS), Aiken, SC (United States); Wilmarth, B. [Savannah River Site (SRS), Aiken, SC (United States); Edwards, R. [Savannah River Site (SRS), Aiken, SC (United States)

    2015-07-01

    This report provides a summary of Phase I activities conducted to support an Integrated Evaluation of Mercury in Liquid Waste System (LWS) Processing Facilities. Phase I activities included a review and assessment of the liquid waste inventory and chemical processing behavior of mercury using a system by system review methodology approach. Gaps in understanding mercury behavior as well as action items from the structured reviews are being tracked. 64% of the gaps and actions have been resolved.

  6. Review of solid–liquid phase change materials and their encapsulation technologies

    OpenAIRE

    Su, Weiguang; Darkwa, Jo; Kokogiannakis, Georgios

    2017-01-01

    Various types of solid–liquid phase change materials (PCMs) have been reviewed for thermal energy storage applications. The review has shown that organic solid–liquid PCMs have much more advantages and capabilities than inorganic PCMs but do possess low thermal conductivity and density as well as being flammable. Inorganic PCMs possess higher heat storage capacities and conductivities, cheaper and readily available as well as being non-flammable, but do experience supercooling and phase segre...

  7. First application of supported ionic liquid phase (SILP) catalysis for continuous methanol carbonylation

    DEFF Research Database (Denmark)

    Riisager, Anders; Jørgensen, Betina; Wasserscheid, Peter

    2006-01-01

    A solid, silica-supported ionic liquid phase (SILP) rhodium iodide Monsanto-type catalyst system, [BMIM][Rh(CO)(2)I-2]-[BMIM]I -SiO2, exhibits excellent activity and selectivity towards acetyl products in fixed-bed, continuous gas-phase methanol carbonylation.......A solid, silica-supported ionic liquid phase (SILP) rhodium iodide Monsanto-type catalyst system, [BMIM][Rh(CO)(2)I-2]-[BMIM]I -SiO2, exhibits excellent activity and selectivity towards acetyl products in fixed-bed, continuous gas-phase methanol carbonylation....

  8. Automatic cryogenic liquid level controller is safe for use near combustible substances

    Science.gov (United States)

    Krejsa, M.

    1966-01-01

    Automatic mechanical liquid level controller that is independent of any external power sources is used with safety in the presence of combustibles. A gas filled capillary tube which leads from a pressurized chamber, is inserted into the cryogenic liquid reservoir and becomes a liquid level sensing element or probe.

  9. Identification of liquid-phase decomposition species and reactions for guanidinium azotetrazolate

    International Nuclear Information System (INIS)

    Kumbhakarna, Neeraj R.; Shah, Kaushal J.; Chowdhury, Arindrajit; Thynell, Stefan T.

    2014-01-01

    Highlights: • Guanidinium azotetrazolate (GzT) is a high-nitrogen energetic material. • FTIR spectroscopy and ToFMS spectrometry were used for species identification. • Quantum mechanics was used to identify transition states and decomposition pathways. • Important reactions in the GzT liquid-phase decomposition process were identified. • Initiation of decomposition occurs via ring opening, releasing N 2 . - Abstract: The objective of this work is to analyze the decomposition of guanidinium azotetrazolate (GzT) in the liquid phase by using a combined experimental and computational approach. The experimental part involves the use of Fourier transform infrared (FTIR) spectroscopy to acquire the spectral transmittance of the evolved gas-phase species from rapid thermolysis, as well as to acquire spectral transmittance of the condensate and residue formed from the decomposition. Time-of-flight mass spectrometry (ToFMS) is also used to acquire mass spectra of the evolved gas-phase species. Sub-milligram samples of GzT were heated at rates of about 2000 K/s to a set temperature (553–573 K) where decomposition occurred under isothermal conditions. N 2 , NH 3 , HCN, guanidine and melamine were identified as products of decomposition. The computational approach is based on using quantum mechanics for confirming the identity of the species observed in experiments and for identifying elementary chemical reactions that formed these species. In these ab initio techniques, various levels of theory and basis sets were used. Based on the calculated enthalpy and free energy values of various molecular structures, important reaction pathways were identified. Initiation of decomposition of GzT occurs via ring opening to release N 2

  10. Behaviour of liquid films and flooding in counter-current two-phase flow, (1)

    International Nuclear Information System (INIS)

    Suzuki, Shin-ichi; Ueda, Tatsuhiro.

    1978-01-01

    This paper reports on the results of study of the behavior of liquid film and flooding in counter-current two phase flow, and the flow speed of gas phase was measured over the wide ranges of tube diameter, tube length, amount of liquid flow, viscosity and surface tension. Liquid samples used for this experiment were water, glycerol, and second octyl alcohol. The phenomena were observed with a high speed camera. The maximum thickness of liquid film was measured, and the effects of various factors on the flooding were investigated. The results of investigation were as follows. The big waves which cause the flooding were developed by the interaction of one of the waves on liquid film surface with gas phase flow. The flow speed of gas phase at the time of beginning of flooding increases with the reduction of amount of liquid flow and the increase of tube diameter. The flooding flow speed is reduced with the increase of tube length. The larger maximum film thickness at the time of no gas phase flow causes flooding at low gas phase flow speed. (Kato, T.)

  11. High-performance liquid chromatography using reversed-phase stationary phases dynamically modified with organophosphorus compound for the separation and determination of lanthanoid elements

    International Nuclear Information System (INIS)

    Tsuyoshi, Akira; Akiba, Kenichi

    2000-01-01

    An acidic organophosphorus compound, 2-ethylhexylphosphonic acid mono-2-ethlhexyl ester (EHPA), has been applied to reversed-phase high-performance liquid chromatography (RP-HPLC). The reversed-phase stationary phase was dynamically modified with EHPA by flowing the mobile phase of an acetone-water mixture containing the extracting regent. The retention of lanthanoid elements was widely varied by changing the conditions of the mobile phase, i.e., the pH, the EHPA concentration and the acetone content. The selectivity of EHPA is well reflected to the chromatographic systems, and a precise separation of lanthanoid elements was achieved with sufficient resolution. The determination of Sm was examined in the presence of a large amount of Nd. A linear calibration graph was obtained for Sm at the level of 10 -7 mol dm -3 , in the presence of 1x10 -4 mol dm -3 of Nd. (author)

  12. 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.

  13. Liquid-Liquid Phase Separation in Model Nuclear Waste Glasses: A Solid-State Double-Resonance NMR Study

    Energy Technology Data Exchange (ETDEWEB)

    Martineau, Ch.; Michaelis, V.K.; Kroeker, S. [Univ Manitoba, Dept Chem, Winnipeg, MB R3T 2N2 (Canada); Schuller, S. [CEA Valrho Marcoule, LDMC, SECM, DTCD, DEN, F-30207 Bagnols Sur Ceze (France)

    2010-07-01

    Double-resonance nuclear magnetic resonance (NMR) techniques are used in addition to single-resonance NMR experiments to probe the degree of mixing between network-forming cations Si and B, along with the modifier cations Cs{sup +} and Na{sup +} in two molybdenum-bearing model nuclear waste glasses. The double-resonance experiments involving {sup 29}Si in natural abundance are made possible by the implementation of a CPMG pulse-train during the acquisition period of the usual REDOR experiments. For the glass with lower Mo content, the NMR results show a high degree of Si-B mixing, as well as an homogeneous distribution of the cations within the borosilicate network, characteristic of a non-phase-separated glass. For the higher-Mo glass, a decrease of B-Si(Q{sup 4}) mixing is observed, indicating phase separation. {sup 23}Na and {sup 133}Cs NMR results show that although the Cs{sup +} cations, which do not seem to be influenced by the molybdenum content, are spread within the borate network, there is a clustering of the Na{sup +} cations, very likely around the molybdate units. The segregation of a Mo-rich region with Na{sup +} cations appears to shift the bulk borosilicate glass composition toward the metastable liquid liquid immiscibility region and induce additional phase separation. Although no crystallization is observed in the present case, this liquid liquid phase separation is likely to be the first stage of crystallization that can occur at higher Mo loadings or be driven by heat treatment. From this study emerges a consistent picture of the nature and extent of such phase separation phenomena in Mo-bearing glasses, and demonstrates the potential of double-resonance NMR methods for the investigation of phase separation in amorphous materials. (authors)

  14. Opalescence of an IgG2 monoclonal antibody solution as it relates to liquid-liquid phase separation.

    Science.gov (United States)

    Mason, Bruce D; Zhang, Le; Remmele, Richard L; Zhang, Jifeng

    2011-11-01

    Opalescence for a monoclonal antibody solution was systematically studied with respect to temperature, protein concentration, ionic strength (using KCl), and pH conditions. Multiple techniques, including measurement of light scattering at 90° and transmission, Tyndall test, and microscopy, were deployed to examine the opalescence behavior. Near the vicinity of the critical point on the liquid-liquid coexistence curve in the temperature-protein concentration phase diagram, the enhanced concentration fluctuations significantly contributed to the critical opalescence evidently by formation of small liquid droplets. Furthermore, our data confirm that away from the critical point, the opalescence behavior is related to the antibody self-association (agglomeration) caused by the attractive antibody-antibody interactions. As expected, at a pH near the pI of the antibody, the solution became less opalescent as the ionic strength increased. However, at a pH below the pI, the opalescence of the solution became stronger, reached a maximum, and then began to drop as the ionic strength further increased. The change in the opalescence correlated well with the trends of protein-protein interactions revealed by the critical temperature from the liquid-liquid phase separation. Copyright © 2011 Wiley-Liss, Inc.

  15. Liquid-liquid equilibrium of water + PEG 8000 + magnesium sulfate or sodium sulfate aqueous two-phase systems at 35°C: experimental determination and thermodynamic modeling

    Directory of Open Access Journals (Sweden)

    B. D. Castro

    2005-09-01

    Full Text Available Liquid-liquid extraction using aqueous two-phase systems is a highly efficient technique for separation and purification of biomolecules due to the mild properties of both liquid phases. Reliable data on the phase behavior of these systems are essential for the design and operation of new separation processes; several authors reported phase diagrams for polymer-polymer systems, but data on polymer-salt systems are still relatively scarce. In this work, experimental liquid-liquid equilibrium data on water + polyethylene glycol 8000 + magnesium sulfate and water + polyethylene glycol 8000 + sodium sulfate aqueous two-phase systems were obtained at 35°C. Both equilibrium phases were analyzed by lyophilization and ashing. Experimental results were correlated with a mass-fraction-based NRTL activity coefficient model. New interaction parameters were estimated with the Simplex method. The mean deviations between the experimental and calculated compositions in both equilibrium phases is about 2%.

  16. Incorporation of ionic liquid into porous polymer monoliths to enhance the separation of small molecules in reversed-phase high-performance liquid chromatography.

    Science.gov (United States)

    Wang, Jiafei; Bai, Ligai; Wei, Zhen; Qin, Junxiao; Ma, Yamin; Liu, Haiyan

    2015-06-01

    An ionic liquid was incorporated into the porous polymer monoliths to afford stationary phases with enhanced chromatographic performance for small molecules in reversed-phase high-performance liquid chromatography. The effect of the ionic liquid in the polymerization mixture on the performance of the monoliths was studied in detail. While monoliths without ionic liquid exhibited poor resolution and low efficiency, the addition of ionic liquid to the polymerization mixture provides highly increased resolution and high efficiency. The chromatographic performances of the monoliths were demonstrated by the separations of various small molecules including aromatic hydrocarbons, isomers, and homologues using a binary polar mobile phase. The present column efficiency reached 27 000 plates/m, which showed that the ionic liquid monoliths are alternative stationary phases in the separation of small molecules by high-performance liquid chromatography. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Strain-induced alignment and phase behavior of blue phase liquid crystals confined to thin films.

    Science.gov (United States)

    Bukusoglu, Emre; Martinez-Gonzalez, Jose A; Wang, Xiaoguang; Zhou, Ye; de Pablo, Juan J; Abbott, Nicholas L

    2017-12-06

    We report on the influence of surface confinement on the phase behavior and strain-induced alignment of thin films of blue phase liquid crystals (BPs). Confining surfaces comprised of bare glass, dimethyloctadecyl [3-(trimethoxysilyl)propyl] ammonium chloride (DMOAP)-functionalized glass, or polyvinyl alcohol (PVA)-coated glass were used with or without mechanically rubbing to influence the azimuthal anchoring of the BPs. These experiments reveal that confinement can change the phase behavior of the BP films. For example, in experiments performed with rubbed-PVA surfaces, we measured the elastic strain of the BPs to change the isotropic-BPII phase boundary, suppressing formation of BPII for film thicknesses incommensurate with the BPII lattice. In addition, we observed strain-induced alignment of the BPs to exhibit a complex dependence on both the surface chemistry and azimuthal alignment of the BPs. For example, when using bare glass surfaces causing azimuthally degenerate and planar anchoring, BPI oriented with (110) planes of the unit cell parallel to the contacting surfaces for thicknesses below 3 μm but transitioned to an orientation with (200) planes aligned parallel to the contacting surfaces for thicknesses above 4 μm. In contrast, BPI aligned with (110) planes parallel to confining surfaces for all other thicknesses and surface treatments, including bare glass with uniform azimuthal alignment. Complementary simulations based on minimization of the total free energy (Landau-de Gennes formalism) confirmed a thickness-dependent reorientation due to strain of BPI unit cells within a window of surface anchoring energies and in the absence of uniform azimuthal alignment. In contrast to BPI, BPII did not exhibit thickness-dependent orientations but did exhibit orientations that were dependent on the surface chemistry, a result that was also captured in simulations by varying the anchoring energies. Overall, the results in this paper reveal that the orientations

  18. Gas-liquid-liquid three-phase flow pattern and pressure drop in a microfluidic chip : similarities with gas-liquid/liquid-liquid flows

    NARCIS (Netherlands)

    Yue, J.; Rebrov, E.; Schouten, J.C.

    2014-01-01

    We report a three-phase slug flow and parallel-slug flow as two major flow patterns found under the nitrogen-decane-water flow through a glass microfluidic chip which features a long microchannel with a hydraulic diameter of 98 µm connected to a cross-flow mixer. The three-phase slug flow pattern is

  19. Radiolytic gas formation in high-level liquid waste solutions

    International Nuclear Information System (INIS)

    Brodda, B.-G.; Dix, Siegfried; Merz, E.R.

    1989-01-01

    High-level fission product waste solutions originating from the first-cycle raffinate stream of spent fast breeder reactor fuel reprocessing have been investigated gas chromatographically for their radiolytic and chemical gas production. The solutions showed considerable formation of hydrogen, carbon dioxide and dinitrogen oxide, whereas atmospheric oxygen was consumed completely within a short time. In particular, carbon dioxide resulted from the radiolytic degradation of entrained organic solvent. After nearly complete degradation of the organic solvent, the influence of hydrazine and nitrogen dioxide on hydrogen formation was investigated. Hydrazinium hydroxide led to the formation of dinitrogen oxide and nitrogen. After 60 d, the concentration of dinitrogen oxide had reduced to zero, whereas the amount of nitrogen formed had reached a maximum. This may be explained by simultaneous chemical and radiolytic reactions leading to the formation of dinitrogen oxide and nitrogen and photolytic fission of dinitrogen oxide. Addition of sodium nitrite resulted in the rapid formation of dinitrogen oxide. The rate of hydrogen production was not changed significantly after the addition of hydrazine or nitrite. The results indicate that under normal operating conditions no dangerous hydrogen radiolysis yields should develop in the course of reprocessing and high-level liquid waste tank storage. Organic entrainment may lead to enhanced radiolytic decomposition and thus to considerable hydrogen production rates and pressure build-up in closed systems. (author)

  20. Energy of formation for AgIn liquid binary alloys along the line of phase separation

    CERN Document Server

    Bhuiyan, G M; Ziauddin-Ahmed, A Z

    2003-01-01

    We have investigated the energy of formation for AgIn liquid binary alloys along the solid-liquid phase separation line. A microscopic theory based on the first order perturbation has been applied. The interionic interaction and a reference liquid are the fundamental components of the theory. These are described by a local pseudopotential and the hard sphere liquids, respectively. The results of calculations reveal a characteristic feature that the energy of formation becomes minimum at the equiatomic composition, and thus indicates maximal mix-ability at this concentration. The energy of formation at a particular thermodynamic state that is at T 1173 K predicts the experimental trends fairly well.

  1. Student Understanding of Liquid-Vapor Phase Equilibrium

    Science.gov (United States)

    Boudreaux, Andrew; Campbell, Craig

    2012-01-01

    Student understanding of the equilibrium coexistence of a liquid and its vapor was the subject of an extended investigation. Written assessment questions were administered to undergraduates enrolled in introductory physics and chemistry courses. Responses have been analyzed to document conceptual and reasoning difficulties in sufficient detail to…

  2. Single-phase liquid jet impingement heat transfer

    International Nuclear Information System (INIS)

    Webb, B.W.; Ma, C.F.

    1995-01-01

    Impinging liquid jets have been demonstrated to be an effective means of providing high heat/mass transfer rates in industrial transport processes. When a liquid jet strikes a surface, thin hydrodynamic and thermal boundary layers from in the region directly beneath due to the jet deceleration and the resulting increase in pressure. The flow is then forced to accelerate in a direction parallel to the target surface in what is termed the wall jet or parallel flow zone. The thickness of the hydrodynamic and thermal boundary layers in the stagnation region may be of the order of tens of micrometers. Consequently, very high heat/mass transfer coefficients exist in the stagnation zone directly under the jet. Transport coefficients characteristic of parallel flow prevail in the wall jet region. The high heat transfer coefficients make liquid jet impingement an attractive cooling option where high heat fluxes are the norm. Some industrial applications include the thermal treatment of metals, cooling of internal combustion engines, and more recently, thermal control of high-heat-dissipation electronic devices. Both circular and planar liquid jets have attracted research attention. 180 refs., 35 figs., 11 tabs

  3. Liquid-Phase Electrical Discharges: Fundamental Mechanisms and Applications

    Science.gov (United States)

    Franclemont, Joshua

    The increased demand in alternative energy in recent decades has generated significant interest in cleaner fuel sources including hydrogen and syngas (hydrogen and carbon monoxide). Hydrogen and syngas are both primarily produced through the steam reforming of hydrocarbons, specifically natural gas. Although other processes are known, the cheapest source of these fuels is currently through the heating of natural gas in the presence of steam and a catalyst. However, due to the emissions associated with the steam reforming of natural gas and the lack of low cost, efficient, and reliable onboard hydrogen storage technologies for fuel cell powered vehicles, attention has been focused on plasma-assisted reforming of hydrocarbons. Plasma processes can be implemented onboard and are able to directly reform liquid hydrocarbons and alcohols without external heating or catalysts. In addition to hydrogen and syngas, the plasma-assisted reforming of hydrocarbons and alcohols offers other desirable products such as C2 gases (ethane, ethylene, and acetylene), methanol and ethanol. The primary goal of this study is to investigate the fundamental chemical reactions occurring during plasma-assisted reforming of liquid hydrocarbons and alcohols using streamer-like pulsed electrical discharges. Due to the relatively unexplored field of chemical reactions in liquid plasmas, the focus of this study is on elucidating chemical pathways responsible for the formation of hydrogen, syngas, and other products during the direct reforming of liquid methanol, glycerol, and pentane as model species.

  4. Data acquisition and quantitative analysis of stable hydrogen isotope in liquid and gas in the liquid phase catalytic exchange process

    International Nuclear Information System (INIS)

    Choi, H. J.; Lee, H. S.; Kim, K. R.; Cheong, H. S.; Ahn, D. H.; Lee, S. H.; Paek, S. W.; Kang, H. S.; Kim, J. G.

    2001-01-01

    A pilot plant for the Liquid Phase Catalytic Exchange process was built and has been operating to test the hydrophobic catalyst developed to remove the tritium generated at the CANDU nuclear power plants. The methods of quantitative analysis of hydrogen stable isotope were compared. Infrared spectroscopy was used for the liquid samples, and gas chromatography with hydrogen carrier gas showed the best result for gas samples. Also, a data acquisition system was developed to record the operation parameters. This record was very useful to investigate the causes of the system trip

  5. The liquid protein phase in crystallization: a case study—intact immunoglobulins

    Science.gov (United States)

    Kuznetsov, Yurii G.; Malkin, Alexander J.; McPherson, Alexander

    2001-11-01

    A common observation by protein chemists has been the appearance, for many proteins in aqueous solutions, of oil like droplets, or in more extreme cases the formation of a second oil like phase. These may accompany the formation of precipitate in "salting out" or "salting in' procedures, but more commonly appear in place of any precipitate. Such phase separations also occur, with even greater frequency, in the presence of polymeric precipitants such as polyethyleneglycol (PEG). In general the appearance of a second liquid phase has been taken as indicative of protein aggregation, though an aggregate state distinctly different from that characteristic of amorphous precipitate. While the latter is thought to be composed of linear and branched assemblies, polymers of a sort, the oil phase suggests a more compact, three-dimensional, but fluid state. An important property of an alternate, fluid phase is that it can mediate transitions between other states, for example, between protein molecules free in solution and protein molecules immobilized in amorphous precipitate or crystals. The "liquid protein" phase can be readily observed in many crystallization experiments either prior to the appearance of visible crystals, or directly participating in the crystal growth process. In some cases the relationship between the liquid phase and developing crystals is intimate. Crystals grow directly from the liquid phase, or appear only after the visible formation of the liquid phase. We describe here our experience with a class of macromolecules, immunoglobulins, and particularly IDEC-151, an IgG specific for CD4 on human lymphocytes. This protein has been crystallized from a Jeffamine-LiSO 4 mother liquor and, its crystallization illustrates many of the features associated with the liquid protein, or protein rich phase.

  6. Determination of three estrogens and bisphenol A by functional ionic liquid dispersive liquid-phase microextraction coupled with ultra-high performance liquid chromatography and ultraviolet detection.

    Science.gov (United States)

    Jiang, Yuehuang; Tang, Tingting; Cao, Zhen; Shi, Guoyue; Zhou, Tianshu

    2015-06-01

    A hydroxyl-functionalized ionic liquid, 1-hydroxyethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, was employed in an improved dispersive liquid-phase microextraction method coupled with ultra high performance liquid chromatography for the enrichment and determination of three estrogens and bisphenol A in environmental water samples. The introduced hydroxyl group acted as the H-bond acceptor that dispersed the ionic liquid effectively in the aqueous phase without dispersive solvent or external force. Fourier transform infrared spectroscopy indicated that the hydroxyl group of the cation of the ionic liquid enhanced the combination of extractant and analytes through the formation of hydrogen bonds. The improvement of the extraction efficiency compared with that with the use of alkyl ionic liquid was proved by a comparison study. The main parameters including volume of extractant, temperature, pH, and extraction time were investigated. The calibration curves were linear in the range of 5.0-1000 μg/L for estrone, estradiol, and bisphenol A, and 10.0-1000 μg/L for estriol. The detection limits were in the range of 1.7-3.4 μg/L. The extraction efficiency was evaluated by enrichment factor that were between 85 and 129. The proposed method was proved to be simple, low cost, and environmentally friendly for the determination of the four endocrine disruptors in environmental water samples. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Solidification of intermediate level liquid waste - ILLW, CEMEX waste form qualification

    International Nuclear Information System (INIS)

    D'Andrea, V.; Guerra, M.; Pancotti, F.; Maio, V.

    2015-01-01

    In the Sogin EUREX Facility about 125 m 3 of intermediate level radioactive waste and about 113 m 3 of low level radioactive waste, produced during the re-processing of MTR and CANDU fuel, are stored. Solidification of these wastes is planned in order to fulfill the specific requirements established by the Safety Authority, taking into account the criteria set up in a Technical Guide on the issue of radioactive waste management. The design of a cementation plant (CEMEX) of all liquid radioactive wastes is currently ongoing. The process requires that the liquid waste is neutralized with NaOH (NaOH 19 M) and metered into 440 liter drum together with the cement, while the mixture is stirred by a lost paddle ('in drum mixing process'). The qualification of the Waste Form consists of all the activities demonstrating that the final cemented product has the minimum requirements (mechanical, chemical and physical characteristics) compliant with all the subsequent management phases: long-term interim storage, transport and long-term disposal of the waste. All tests performed to qualify the conditioning process for immobilizing first extraction cycle (MTR and CANDU) and second extraction cycle liquid wastes, gave results in compliance with the minimum requirements established for disposal

  8. Liquid-gas phase transition and isospin fractionation in intermediate energy heavy ion collisions

    International Nuclear Information System (INIS)

    Xing Yongzhong; Liu Jianye; Guo Wenjun

    2004-01-01

    The liquid-gas phase transition in the heavy ion collisions and nuclear matter has been an important topic and got achievements, such as, based on the studies by H.Q. Song et al the critical temperature of liquid-gas phase transition enhances with increasing the mass of system and reduces as the increase of the neutron proton ratio of system. As authors know that both the liquid-gas phase transition and the isospin fractionation occur in the spinodal instability region at the nuclear density below the normal nuclear density. In particular, these two dynamical processes lead to the separation of nuclear matter into the liquid phase and gas phase. In this case to compare their dynamical behaviors is interested. The authors investigate the dependence of isospin fractionation degree on the mass and neutron proton ratio of system by using the isospin dependent quantum molecular dynamics model. The authors found that the degree of isospin fractionation (N/Z) n /(N/Z) imf decreases with increasing the mass of the system. This is just similar to the enhance of the critical temperature of liquid-gas phase transition T c as the increase of system mass. Because the enhance of T c is not favorable for the liquid-gas transition taking place, which reduces the isospin fractionation process and leads to decrease of (N/Z) n /(N/Z) imf . However the degree of isospin fractionation enhances with increasing the neutron proton ratio of the system. It is just corresponding to the reduce of T c of the liquid-gas phase transition as the increase of the isospin fractionation of the system. Because the reduce of T c enhances the liquid-gas phase transition process and also prompts the isospin fractionation process leading the increase of the isospin fractionation degree. To sum up, there are very similar dynamical behaviors for the degree of isospin fractionation and the critical temperature of the liquid-gas phase transition. So dynamical properties of the liquid-gas phase transition can

  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. Transmission-lattice based geometric phase analysis for evaluating the dynamic deformation of a liquid surface.

    Science.gov (United States)

    Shi, Wenxiong; Huang, Xianfu; Liu, Zhanwei

    2014-05-05

    Quantitatively measuring a dynamic liquid surface often presents a challenge due to high transparency, fluidity and specular reflection. Here, a novel Transmission-Lattice based Geometric Phase Analysis (TLGPA) method is introduced. In this method, a special lattice is placed underneath a liquid to be tested and, when viewed from above, the phase of the transmission-lattice image is modulated by the deformation of the liquid surface. Combining this with multi-directional Newton iteration algorithms, the dynamic deformation field of the liquid surface can be calculated from the phase variation of a series of transmission-lattice images captured at different moments. The developed method has the advantage of strong self-adaption ability to initial lattice rotational errors and this is discussed in detail. Dynamic 3D ripples formation and propagation was investigated and the results obtained demonstrated the feasibility of the method.

  11. Abnormal gas-liquid-solid phase transition behaviour of water observed with in situ environmental SEM.

    Science.gov (United States)

    Chen, Xin; Shu, Jiapei; Chen, Qing

    2017-04-24

    Gas-liquid-solid phase transition behaviour of water is studied with environmental scanning electron microscopy for the first time. Abnormal phenomena are observed. At a fixed pressure of 450 Pa, with the temperature set to -7 °C, direct desublimation happens, and ice grows continuously along the substrate surface. At 550 Pa, although ice is the stable phase according to the phase diagram, metastable liquid droplets first nucleate and grow to ~100-200 μm sizes. Ice crystals nucleate within the large sized droplets, grow up and fill up the droplets. Later, the ice crystals grow continuously through desublimation. At 600 Pa, the metastable liquid grows quickly, with some ice nuclei floating in it, and the liquid-solid coexistence state exists for a long time. By lowering the vapour pressure and/or increasing the substrate temperature, ice sublimates into vapour phase, and especially, the remaining ice forms a porous structure due to preferential sublimation in the concave regions, which can be explained with surface tension effect. Interestingly, although it should be forbidden for ice to transform into liquid phase when the temperature is well below 0 °C, liquid like droplets form during the ice sublimation process, which is attributed to the surface tension effect and the quasiliquid layers.

  12. Liquid-phase microextraction in a microfluidic-chip

    DEFF Research Database (Denmark)

    Payán, María D. Ramos; Jensen, Henrik; Petersen, Nickolaj J.

    2012-01-01

    , methadone, haloperidol, loperamide, and pethidine were selected as model analytes, and they were extracted from alkaline sample solution, through the SLM, and into 10mM HCl or 100mM HCOOH functioning as acceptor phase. Subsequently, the acceptor phase was either analyzed off-line by capillary...

  13. Biochemical process of low level radioactive liquid simulation waste containing detergent

    International Nuclear Information System (INIS)

    Kundari, Noor Anis; Putra, Sugili; Mukaromah, Umi

    2015-01-01

    Research of biochemical process of low level radioactive liquid waste containing detergent has been done. Thse organic liquid wastes are generated in nuclear facilities such as from laundry. The wastes that are cotegorized as hazard and poison materials are also radioactive. It must be treated properly by detoxification of the hazard and decontamination of the radionuclides to ensure that the disposal of the waste meets the requirement of standard quality of water. This research was intended to determine decontamination factor and separation efficiensies, its kinetics law, and to produce a supernatant that ensured the environmental quality standard. The radioactive element in the waste was thorium with activity of 5.10 −5 Ci/m 3 . The radioactive liquid waste which were generated in simulation plant contains detergents that was further processed by aerobic biochemical process using SGB 103 bacteria in a batch reactor equipped with aerators. Two different concentration of samples were processed and analyzed for 212 hours and 183 hours respectively at a room temperature. The product of this process is a liquid phase called as supernatant and solid phase material called sludge. The chemical oxygen demand (COD), biological oxygen demand (BOD), suspended solid (SS), and its alpha activity were analyzed. The results show that the decontamination factor and the separation efficiency of the lower concentration samples are higher compared to the samples with high concentration. Regarding the decontamination factor, the result for 212 hours processing of waste with detergent concentration of 1.496 g/L was 3.496 times, whereas at the detergent concentration of 0.748 g/L was 15.305 times for 183 hours processing. In case of the separation efficiency, the results for both samples were 71.396% and 93.465% respectively. The Bacterial growth kinetics equation follow Monod’s model and the decreasing of COD and BOD were first order with the rate constant of 0.01 hour −1

  14. Biochemical process of low level radioactive liquid simulation waste containing detergent

    Energy Technology Data Exchange (ETDEWEB)

    Kundari, Noor Anis, E-mail: nooranis@batan.go.id; Putra, Sugili; Mukaromah, Umi [Sekolah Tinggi Teknologi Nuklir – Badan Tenaga Nuklir Nasional Jl. Babarsari P.O. BOX 6101 YKBB Yogyakarta 55281 Telp : (0274) 48085, 489716, Fax : (0274) 489715 (Indonesia)

    2015-12-29

    Research of biochemical process of low level radioactive liquid waste containing detergent has been done. Thse organic liquid wastes are generated in nuclear facilities such as from laundry. The wastes that are cotegorized as hazard and poison materials are also radioactive. It must be treated properly by detoxification of the hazard and decontamination of the radionuclides to ensure that the disposal of the waste meets the requirement of standard quality of water. This research was intended to determine decontamination factor and separation efficiensies, its kinetics law, and to produce a supernatant that ensured the environmental quality standard. The radioactive element in the waste was thorium with activity of 5.10{sup −5} Ci/m{sup 3}. The radioactive liquid waste which were generated in simulation plant contains detergents that was further processed by aerobic biochemical process using SGB 103 bacteria in a batch reactor equipped with aerators. Two different concentration of samples were processed and analyzed for 212 hours and 183 hours respectively at a room temperature. The product of this process is a liquid phase called as supernatant and solid phase material called sludge. The chemical oxygen demand (COD), biological oxygen demand (BOD), suspended solid (SS), and its alpha activity were analyzed. The results show that the decontamination factor and the separation efficiency of the lower concentration samples are higher compared to the samples with high concentration. Regarding the decontamination factor, the result for 212 hours processing of waste with detergent concentration of 1.496 g/L was 3.496 times, whereas at the detergent concentration of 0.748 g/L was 15.305 times for 183 hours processing. In case of the separation efficiency, the results for both samples were 71.396% and 93.465% respectively. The Bacterial growth kinetics equation follow Monod’s model and the decreasing of COD and BOD were first order with the rate constant of 0

  15. Biochemical process of low level radioactive liquid simulation waste containing detergent

    Science.gov (United States)

    Kundari, Noor Anis; Putra, Sugili; Mukaromah, Umi

    2015-12-01

    Research of biochemical process of low level radioactive liquid waste containing detergent has been done. Thse organic liquid wastes are generated in nuclear facilities such as from laundry. The wastes that are cotegorized as hazard and poison materials are also radioactive. It must be treated properly by detoxification of the hazard and decontamination of the radionuclides to ensure that the disposal of the waste meets the requirement of standard quality of water. This research was intended to determine decontamination factor and separation efficiensies, its kinetics law, and to produce a supernatant that ensured the environmental quality standard. The radioactive element in the waste was thorium with activity of 5.10-5 Ci/m3. The radioactive liquid waste which were generated in simulation plant contains detergents that was further processed by aerobic biochemical process using SGB 103 bacteria in a batch reactor equipped with aerators. Two different concentration of samples were processed and analyzed for 212 hours and 183 hours respectively at a room temperature. The product of this process is a liquid phase called as supernatant and solid phase material called sludge. The chemical oxygen demand (COD), biological oxygen demand (BOD), suspended solid (SS), and its alpha activity were analyzed. The results show that the decontamination factor and the separation efficiency of the lower concentration samples are higher compared to the samples with high concentration. Regarding the decontamination factor, the result for 212 hours processing of waste with detergent concentration of 1.496 g/L was 3.496 times, whereas at the detergent concentration of 0.748 g/L was 15.305 times for 183 hours processing. In case of the separation efficiency, the results for both samples were 71.396% and 93.465% respectively. The Bacterial growth kinetics equation follow Monod's model and the decreasing of COD and BOD were first order with the rate constant of 0.01 hour-1.

  16. The geometric phase in two-level atomic systems

    International Nuclear Information System (INIS)

    Tian Mingzhen; Barber, Zeb W.; Fischer, Joe A.; Randall Babbitt, Wm.

    2004-01-01

    We report the observation of the geometric phase in a closed two-level atomic system using stimulated photon echoes. The two-level system studied consists of the two-electronic energy levels ( 3 H 4 and 3 H 6 ) of Tm 3+ doped in YAG crystal. When a two-level atom at an arbitrary superposition state is excited by a pair of specially designed laser pulses, the excited state component gains a relative phase with respect to the ground state component. We identified the phase shift to be of pure geometric nature. The dynamic phase associated to the driving Hamiltonian is unchanged. The experiment results of the phase change agree with the theory to the extent of the measurement limit

  17. Versatile ligands for high-performance liquid chromatography: An overview of ionic liquid-functionalized stationary phases.

    Science.gov (United States)

    Zhang, Mingliang; Mallik, Abul K; Takafuji, Makoto; Ihara, Hirotaka; Qiu, Hongdeng

    2015-08-05

    Ionic liquids (ILs), a class of unique substances composed purely by cation and anions, are renowned for their fascinating physical and chemical properties, such as negligible volatility, high dissolution power, high thermal stability, tunable structure and miscibility. They are enjoying ever-growing applications in a great diversity of disciplines. IL-modified silica, transforming the merits of ILs into chromatographic advantages, has endowed the development of high-performance liquid chromatography (HPLC) stationary phase with considerable vitality. In the last decade, IL-functionalized silica stationary phases have evolved into a series of branches to accommodate to different HPLC modes. An up-to-date overview of IL-immobilized stationary phases is presented in this review, and divided into five parts according to application mode, i.e., ion-exchange, normal-phase, reversed-phase, hydrophilic interaction and chiral recognition. Specific attention is channeled to synthetic strategies, chromatographic behavior and separation performance of IL-functionalized silica stationary phases. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Single-phase and two-phase gas-liquid turbulent mixing between subchannels in a simulated rod bundle

    International Nuclear Information System (INIS)

    Sadatomi, Michio; Kawahara, Akimaro; Sato, Yoshifusa; Tomino, Takayoshi.

    1996-01-01

    This study is concerned with turbulent mixing which is one of the three mechanisms of cross flows between subchannels in a nuclear fuel rod bundle. The channel used in this experiments was a vertical simulated rod bundle having two subchannels connected through 1 to 3 gaps between two rods and/or rod and channel wall. The number of the gaps was changed to investigate the effect of the number on the turbulent mixing. Turbulent mixing rates of air and water and fluctuations of pressure difference between the subchannels were measured for single-phase and two-phase gas-liquid flows under hydrodynamic equilibrium flow conditions. It has been confirmed that the turbulent mixing rate is affected strongly by the fluctuations especially for liquid phase in two-phase slug or churn flow. (author)

  19. Ionic liquid-modified materials for solid-phase extraction and separation: a review.

    Science.gov (United States)

    Vidal, Lorena; Riekkola, Marja-Liisa; Canals, Antonio

    2012-02-17

    In recent years, materials science has propelled to the research forefront. Ionic liquids with unique and fascinating properties have also left their footprints to the developments of materials science during the last years. In this review we highlight some of their recent advances and provide an overview at the current status of ionic liquid-modified materials applied in solid-phase extraction, liquid and gas chromatography and capillary electrochromatography with reference to recent applications. In addition, the potential of ionic liquids in the modification of capillary inner wall in capillary electrophoresis is demonstrated. The main target material modified with ionic liquids is silica, but polymers and monoliths have recently joined the studies. Although imidazolium is still clearly the most commonly used ionic liquid for the covalently modification of materials, the exploitation of pyridinium and phosphonium will most probably increase in the future. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. First application of supported ionic liquid phase (SILP) catalysis for continuous methanol carbonylation.

    Science.gov (United States)

    Riisager, Anders; Jørgensen, Betina; Wasserscheid, Peter; Fehrmann, Rasmus

    2006-03-07

    A solid, silica-supported ionic liquid phase (SILP) rhodium iodide Monsanto-type catalyst system, [BMIM][Rh(CO)2I2]-[BMIM]I-SiO2, exhibits excellent activity and selectivity towards acetyl products in fixed-bed, continuous gas-phase methanol carbonylation.

  1. Stability and kinetic studies of supported ionic liquid phase catalysts for hydroformylation of propene

    DEFF Research Database (Denmark)

    Riisager, Anders; Fehrmann, Rasmus; Haumann, Marco

    2005-01-01

    Supported ionic liquid phase (SILP) catalysts have been studied with regard to their long-term stability in the continuous gas-phase hydroformylation of propene. Kinetic data have been acquired by variation of temperature, pressure, syngas composition, substrate concentration, and residence time...

  2. Raman Spectroscopic Study of the Vapour Phase of 1-Methylimidazolium Ethanoate, a Protic Ionic Liquid

    DEFF Research Database (Denmark)

    Berg, Rolf W.; Canongia Lopes, Jose N.; Ferreira, Rui

    2010-01-01

    The gas phase over the ionic liquid 1-methylimidazolium ethanoate, [Hmim][O2CCH3], was studied by means of Raman spectroscopy. Raman spectra are presented, the species in the gas phase are identified, and their bands are assigned. The results are interpreted using ab initio quantum mechanical...

  3. Formation of tilted smectic-C liquid crystal phase in polar Gay-Berne molecules

    International Nuclear Information System (INIS)

    Saha, J.; Bose, T.R.; Ghosh, D.; Saha, M.

    2005-01-01

    We perform molecular dynamics simulation for a system of Gay-Berne molecules having two terminal dipole moments to generate tilted smectic-C liquid crystal phase. We investigate the effect of dipolar orientation with respect to the long molecular axis on phase behaviour. The study indicates that larger dipolar angle can give rise to greater tilt in molecular organization within a layer

  4. Quark-Gluon Soup -- The Perfectly Liquid Phase of QCD

    Science.gov (United States)

    Heinz, Ulrich

    2015-03-01

    At temperatures above about 150 MeV and energy densities exceeding 500 MeV/fm3, quarks and gluons exist in the form of a plasma of free color charges that is about 1000 times hotter and a billion times denser than any other plasma ever created in the laboratory. This quark-gluon plasma (QGP) turns out to be strongly coupled, flowing like a liquid. About 35 years ago, the nuclear physics community started a program of relativistic heavy-ion collisions with the goal of producing and studying QGP under controlled laboratory conditions. This article recounts the story of its successful creation in collider experiments at Brookhaven National Laboratory and CERN and the subsequent discovery of its almost perfectly liquid nature, and reports on the recent quantitatively precise determination of its thermodynamic and transport properties.

  5. LIQUID-LIQUID EXTRACTION COLUMNS

    Science.gov (United States)

    Thornton, J.D.

    1957-12-31

    This patent relates to liquid-liquid extraction columns having a means for pulsing the liquid in the column to give it an oscillatory up and down movement, and consists of a packed column, an inlet pipe for the dispersed liquid phase and an outlet pipe for the continuous liquid phase located in the direct communication with the liquid in the lower part of said column, an inlet pipe for the continuous liquid phase and an outlet pipe for the dispersed liquid phase located in direct communication with the liquid in the upper part of said column, a tube having one end communicating with liquid in the lower part of said column and having its upper end located above the level of said outlet pipe for the dispersed phase, and a piston and cylinder connected to the upper end of said tube for applying a pulsating pneumatic pressure to the surface of the liquid in said tube so that said surface rises and falls in said tube.

  6. Physico-Chemical Properties and Phase Behaviour of Pyrrolidinium-Based Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Urszula Domańska

    2010-04-01

    Full Text Available A review of the relevant literature on 1-alkyl-1-methylpyrrolidinium-based ionic liquids has been presented. The phase diagrams for the binary systems of {1-ethyl-1-methylpyrrolidinium trifluoromethanesulfonate (triflate [EMPYR][CF3SO3] + water, or + 1-butanol} and for the binary systems of {1-propyl-1-methylpyrrolidinium trifluoromethanesulfonate (triflate [PMPYR][CF3SO3] + water, or + an alcohol (1-butanol, 1-hexanol, 1-octanol, 1-decanol} have been determined at atmospheric pressure using a dynamic method. The influence of alcohol chain length was discussed for the [PMPYR][CF3SO3]. A systematic decrease in the solubility was observed with an increase of the alkyl chain length of an alcohol. (Solid + liquid phase equilibria with complete miscibility in the liquid phase region were observed for the systems involving water and alcohols. The solubility of the ionic liquid increases as the alkyl chain length on the pyrrolidinium cation increases. The correlation of the experimental data has been carried out using the Wilson, UNIQUAC and the NRTL equations. The phase diagrams reported here have been compared to the systems published earlier with the 1-alkyl-1-methylpyrrolidinium-based ionic liquids. The influence of the cation and anion on the phase behaviour has been discussed. The basic thermal properties of pure ILs, i.e., melting temperature and the enthalpy of fusion, the solid-solid phase transition temperature and enthalpy have been measured using a differential scanning microcalorimetry technique.

  7. Characterization of rhamnolipids by liquid chromatography/mass spectrometry after solid-phase extraction.

    Science.gov (United States)

    Behrens, Beate; Engelen, Jeannine; Tiso, Till; Blank, Lars Mathias; Hayen, Heiko

    2016-04-01

    Rhamnolipids are surface-active agents with a broad application potential that are produced in complex mixtures by bacteria of the genus Pseudomonas. Analysis from fermentation broth is often characterized by laborious sample preparation and requires hyphenated analytical techniques like liquid chromatography coupled to mass spectrometry (LC-MS) to obtain detailed information about sample composition. In this study, an analytical procedure based on chromatographic method development and characterization of rhamnolipid sample material by LC-MS as well as a comparison of two sample preparation methods, i.e., liquid-liquid extraction and solid-phase extraction, is presented. Efficient separation was achieved under reversed-phase conditions using a mixed propylphenyl and octadecylsilyl-modified silica gel stationary phase. LC-MS/MS analysis of a supernatant from Pseudomonas putida strain KT2440 pVLT33_rhlABC grown on glucose as sole carbon source and purified by solid-phase extraction revealed a total of 20 congeners of di-rhamnolipids, mono-rhamnolipids, and their biosynthetic precursors 3-(3-hydroxyalkanoyloxy)alkanoic acids (HAAs) with different carbon chain lengths from C8 to C14, including three rhamnolipids with uncommon C9 and C11 fatty acid residues. LC-MS and the orcinol assay were used to evaluate the developed solid-phase extraction method in comparison with the established liquid-liquid extraction. Solid-phase extraction exhibited higher yields and reproducibility as well as lower experimental effort.

  8. Phase equilibrium and physical properties of biobased ionic liquid mixtures.

    Science.gov (United States)

    Toledo Hijo, Ariel A C; Maximo, Guilherme J; Cunha, Rosiane L; Fonseca, Felipe H S; Cardoso, Lisandro P; Pereira, Jorge F B; Costa, Mariana C; Batista, Eduardo A C; Meirelles, Antonio J A

    2018-02-28

    Protic ionic liquid crystals (PILCs) obtained from natural sources are promising compounds due to their peculiar properties and sustainable appeal. However, obtaining PILCs with higher thermal and mechanical stabilities for product and process design is in demand and studies on such approaches using this new IL generation are still scarce. In this context, this work discloses an alternative way for tuning the physicochemical properties of ILCs by mixing PILs. New binary mixtures of PILs derived from fatty acids and 2-hydroxy ethylamines have been synthesized here and investigated through the characterization of the solid-solid-[liquid crystal]-liquid thermodynamic equilibrium and their rheological and critical micellar concentration profiles. The mixtures presented a marked nonideal melting profile with the formation of solid solutions. This work revealed an improvement of the PILCs' properties based on a significant increase in the ILC temperature domain and the obtainment of more stable mesophases at high temperatures when compared to pure PILs. In addition, mixtures of PILs also showed significant changes in their non-Newtonian and viscosity profile up to 100 s -1 , as well as mechanical stability over a wide temperature range. The enhancement of the physicochemical properties of PILs here disclosed by such an approach leads to more new possibilities of their industrial application at high temperatures.

  9. Practical solid and liquid phase markers for studying gastric emptying in man

    International Nuclear Information System (INIS)

    Thomforde, G.M.; Brown, M.L.; Malagelada, J.R.

    1985-01-01

    This paper presents a method used to evaluate solid and liquid phase markers for radionuclide gastric emptying studies. The authors conducted in vitro and in vivo comparative experiments employing several radiolabeled markers. Among the solid phase markers tested, Tc-99m-sulfur colloid in vivo-labeled liver and I-131-fiber performed optimally. However, Tc-99M sulfur colloid in scrambled egg showed very acceptable performance and it is significantly easier to prepare. Among liquid phase markers, they found In-111-DTPA stabilized with 1% albumin to be a good agent and appropriate for dual isotope emptying studies

  10. Gas-liquid two-phase flow behavior in terrain-inclined pipelines for gathering transport system of wet natural gas

    DEFF Research Database (Denmark)

    Yang, Yan; Li, Jingbo; Wang, Shuli

    2018-01-01

    The Volume of Fluid method and Re-Normalisation Group (RNG) k-ε turbulence model were employed to predict the gas-liquid two-phase flow in a terrain-inclined pipeline with deposited liquids. The simulation was carried out in a 22.5 m terrain-inclined pipeline with a 150 mm internal diameter...... on the liquid level under the suction force which caused by the negative pressure around the elbow, and then it touched to the top of the pipe. When the liquid blocked the pipe, the pressure drop between the upstream and downstream of the elbow increased with the increase of the gas velocity. At larger gas...

  11. Concentration of High Level Radioactive Liquid Waste. Basic data acquisition

    Energy Technology Data Exchange (ETDEWEB)

    Juvenelle, A.; Masson, M.; Garrido, M.H. [DEN/VRH/DRCP/SCPS/LPCP, BP 17171 - 30207 Bagnols sur Ceze Cedex (France)

    2008-07-01

    Full text of publication follows: In order to enhance its knowledge about the concentration of high level liquid waste (HLLW) from the nuclear fuel reprocessing process, a program of studies was defined by Cea. In a large field of acidity, it proposes to characterize the concentrated solution and the obtained precipitates versus the concentration factor. Four steps are considered: quantification of the salting-out effect on the concentrate acidity, acquisition of solubility data, precipitates characterisation versus the concentration factor through aging tests and concentration experimentation starting from simulated fission products solutions. The first results, reported here, connect the acidity of the concentrated solution to the concentration factor and allow us to precise the field of acidity (4 to 12 N) for the next experiments. In this field, solubility data of various elements (Ba, Sr, Zr...) are separately measured at room temperature, in nitric acid in a first time, then in the presence of various species present in medium (TBP, PO{sub 4}{sup 3-}). The reactions between these various elements are then investigated (formation of insoluble mixed compounds) by following the concentration cations in solution and characterising the precipitates. (authors)

  12. Low-level measurements by liquid scintillation counting

    International Nuclear Information System (INIS)

    Schoenhofer, F.

    1991-01-01

    Liquid scintillation counting has become a convenient tool for analysis of many beta- and alpha-emitters even in ultra low-level concentration ranges. Extremely low background is achieved in a commercially available counter by an active shielding and heavy lead shielding. Thus special time saving radiochemical separation processes could be designed. Extremely simple sample preparation techniques can be used. Counting time can be reduced and sample throughput enhanced. Also precision can be enhanced. From the author's research, several applications are discussed. They include: tritium in water without enrichment, tritium in urine (excretion analysis), carbon-14 in samples like alcohol or vinegar, Rn-222 in water and air, even gaseous Kr-85. A simple and fast method for Sr-90 in environmental samples and food has been developed and the Ra-226-concentration in water can be measured as low as 30 mBq/l without any chemical separation or enrichment. The instrument has been used successfully for screening purposes after the Chernobyl accident as well as for monitoring groundwater after a large scale contamination in Lower Austria. Using a 'gross-beta-measurement' effluents from a nuclear installation are monitored, clearly showing advantages over traditional methods. α-β-discrimination reduces the background for alpha emitters to practically zero. Examples from the determination of Ra-226 in water are shown

  13. Liquid-phase turbulence measurements in air-water two-phase flows over a wide range of void fractions

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xinquan [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, 201 W. 19th Ave., Columbus, OH 43210 (United States); Sun, Xiaodong, E-mail: sun.200@osu.edu [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, 201 W. 19th Ave., Columbus, OH 43210 (United States); Liu, Yang [Nuclear Engineering Program, Department of Mechanical Engineering, Virginia Tech, 635 Prices Fork Road, Blacksburg, VA 24061 (United States)

    2016-12-15

    This paper focuses on liquid-phase turbulence measurements in air-water two-phase flows over a wide range of void fractions and flow regimes, spanning from bubbly, cap-bubbly, slug, to churn-turbulent flows. The measurements have been conducted in two test facilities, the first one with a circular test section and the second one with a rectangular test section. A particle image velocimetry-planar laser-induced fluorescence (PIV-PLIF) system was used to acquire local liquid-phase turbulence information, including the time-averaged velocity and velocity fluctuations in the streamwise and spanwise directions, and Reynolds stress. An optical phase separation method using fluorescent particles and optical filtration technique was adopted to extract the liquid-phase velocity information. An image pre-processing scheme was imposed on the raw PIV images acquired to remove noise due to the presence of bubble residuals and optically distorted particles in the raw PIV images. Four-sensor conductivity probes and high-speed images were also used to acquire the gas-phase information, which was aimed to understand the flow interfacial structure. The highest area-averaged void fraction covered in the measurements for the circular and rectangular test sections was about 40%.

  14. Liquid-phase turbulence measurements in air-water two-phase flows over a wide range of void fractions

    International Nuclear Information System (INIS)

    Zhou, Xinquan; Sun, Xiaodong; Liu, Yang

    2016-01-01

    This paper focuses on liquid-phase turbulence measurements in air-water two-phase flows over a wide range of void fractions and flow regimes, spanning from bubbly, cap-bubbly, slug, to churn-turbulent flows. The measurements have been conducted in two test facilities, the first one with a circular test section and the second one with a rectangular test section. A particle image velocimetry-planar laser-induced fluorescence (PIV-PLIF) system was used to acquire local liquid-phase turbulence information, including the time-averaged velocity and velocity fluctuations in the streamwise and spanwise directions, and Reynolds stress. An optical phase separation method using fluorescent particles and optical filtration technique was adopted to extract the liquid-phase velocity information. An image pre-processing scheme was imposed on the raw PIV images acquired to remove noise due to the presence of bubble residuals and optically distorted particles in the raw PIV images. Four-sensor conductivity probes and high-speed images were also used to acquire the gas-phase information, which was aimed to understand the flow interfacial structure. The highest area-averaged void fraction covered in the measurements for the circular and rectangular test sections was about 40%.

  15. A multi-phase equation of state for solid and liquid lead

    International Nuclear Information System (INIS)

    Robinson, C.M.

    2004-01-01

    This paper considers a multi-phase equation of state for solid and liquid lead. The thermodynamically consistent equation of state is constructed by calculating separate equations of state for the solid and liquid phases. The melt curve is the curve in the pressure, temperature plane where the Gibb's free energy of the solid and liquid phases are equal. In each phase a complete equation of state is obtained using the assumptions that the specific heat capacity is constant and that the Grueneisen parameter is proportional to the specific volume. The parameters for the equation of state are obtained from experimental data. In particular they are chosen to match melt curve and principal Hugoniot data. Predictions are made for the shock pressure required for melt to occur on shock and release

  16. Origins of phase contrast in the atomic force microscope in liquids.

    Science.gov (United States)

    Melcher, John; Carrasco, Carolina; Xu, Xin; Carrascosa, José L; Gómez-Herrero, Julio; José de Pablo, Pedro; Raman, Arvind

    2009-08-18

    We study the physical origins of phase contrast in dynamic atomic force microscopy (dAFM) in liquids where low-stiffness microcantilever probes are often used for nanoscale imaging of soft biological samples with gentle forces. Under these conditions, we show that the phase contrast derives primarily from a unique energy flow channel that opens up in liquids due to the momentary excitation of higher eigenmodes. Contrary to the common assumption, phase-contrast images in liquids using soft microcantilevers are often maps of short-range conservative interactions, such as local elastic response, rather than tip-sample dissipation. The theory is used to demonstrate variations in local elasticity of purple membrane and bacteriophage 29 virions in buffer solutions using the phase-contrast images.

  17. The questions of liquid metal two-phase flow modelling in the FBR core channels

    International Nuclear Information System (INIS)

    Martsiniouk, D.Ye.; Sorokin, A.P.

    2000-01-01

    The two-fluid model representation for calculations of two-phase flow characteristics in the FBR fuel pin bundles with liquid metal cooling is presented and analysed. Two conservation equations systems of the mass, momentum and energy have been written for each phase. Components accounted the mass-, momentum- and heat transfer throughout the interface occur in the macro-field equations after the averaging procedure realisation. The pattern map and correlations for two-fluid model in vertical liquid metal flows are presented. The description of processes interphase mass- and heat exchange and interphase friction is determined by the two-phase flow regime. The opportunity of the liquid metal two-phase flow regime definition is analysed. (author)

  18. Characterization of retentivity of reversed phase liquid chromatography columns.

    Science.gov (United States)

    Ying, P T; Dorsey, J G

    1991-03-01

    There are dozens of commercially available reversed phase columns, most marketed as C-8 or C-18 materials, but with no useful way of classifying their retentivity. A useful way of ranking these columns in terms of column "strength" or retentivity is presented. The method utilizes a value for ln k'(w), the estimated retention of a solute from a mobile phase of 100% water, and the slope of the plot of ln k' vsE(T)(30), the solvent polarity. The method is validated with 26 solutes varying in ln k'(w) from about 2 to over 20, on 14 different reversed phase columns. In agreement with previous work, it is found that the phase volume ratio of the column is the most important parameter in determining retentivity. It is strongly suggested that manufacturers adopt a uniform method of calculating this value and that it be made available in advertising, rather than the uninterpretable "% carbon".

  19. Characterization of Isomeric Glycans by Reversed Phase Liquid Chromatography-Electronic Excitation Dissociation Tandem Mass Spectrometry

    Science.gov (United States)

    Tang, Yang; Wei, Juan; Costello, Catherine E.; Lin, Cheng

    2018-04-01

    The occurrence of numerous structural isomers in glycans from biological sources presents a severe challenge for structural glycomics. The subtle differences among isomeric structures demand analytical methods that can provide structural details while working efficiently with on-line glycan separation methods. Although liquid chromatography-tandem mass spectrometry (LC-MS/MS) is a powerful tool for mixture analysis, the commonly utilized collision-induced dissociation (CID) method often does not generate a sufficient number of fragments at the MS2 level for comprehensive structural characterization. Here, we studied the electronic excitation dissociation (EED) behaviors of metal-adducted, permethylated glycans, and identified key spectral features that could facilitate both topology and linkage determinations. We developed an EED-based, nanoscale, reversed phase (RP)LC-MS/MS platform, and demonstrated its ability to achieve complete structural elucidation of up to five structural isomers in a single LC-MS/MS analysis. [Figure not available: see fulltext.

  20. MEASUREMENTS IN A LIQUID ATOMISER SPRAY USING THE PHASE-DOPPLER PARTICLE ANALYSER

    Directory of Open Access Journals (Sweden)

    R HADEF

    2000-12-01

    Full Text Available Experiments have been carried out at atmospheric conditions using a water atomiser spray. A phase Doppler anemometry was used to perform the measurements of the droplets size, their velocity and concentration, and photographs were taken.  The results showed that the small particles with low turbulence occupied the central core of the jet displaying a Gaussian profile for the axial velocity component.  The large particles were defected towards the outer edges of the jet, due to their higher initial momentum, and displayed relatively high levels of turbulence. The variables measured show that their spatial distributions were nearly symmetrical about the x-axis and although the number density of the droplets is very high in the centred region, most of the pulverised liquid was present in the edges of the spray.

  1. [Reversed-phase high-performance liquid chromatograph--application to serum aluminium monitoring].

    Science.gov (United States)

    Hoshino, H; Kaneko, E

    1996-01-01

    High-Performance Liquid Chromatography (HPLC) with the reversed-phase partition mode separation (including ion-pair one) towards metal chelate compounds prepared in an off-line fashion (precolumn chelation) is most versatile in terms of high sensitivity with base-line flatness, unique selectivity and cost effectiveness. The extraordinary toughness to the complicated matrices encountered in clinical testing is exemplified by the successful application to the aluminium monitoring of human serum samples. The A1 chelate with 2,2'-dihydroxyazobenzene is efficiently chromatographed on a LiChroCART RP-18 column using an aqueous methanol eluent (63.6 wt%) containing tetrabutylammonium bromide as an ion-pair agent. The serum concentration level of A1 down to 6 micrograms dm-3 is readily monitored without influences from iron, chyle and haemolysis.

  2. Liquid-phase microextraction combined with graphite furnace atomic absorption spectrometry: A review.

    Science.gov (United States)

    de la Calle, Inmaculada; Pena-Pereira, Francisco; Lavilla, Isela; Bendicho, Carlos

    2016-09-14

    An overview of the combination of liquid-phase microextraction (LPME) techniques with graphite furnace atomic absorption spectrometry (GFAAS) is reported herein. The high sensitivity of GFAAS is significantly enhanced by its association with a variety of miniaturized solvent extraction approaches. LPME-GFAAS thus represents a powerful combination for determination of metals, metalloids and organometallic compounds at (ultra)trace level. Different LPME modes used with GFAAS are briefly described, and the experimental parameters that show an impact in those microextraction processes are discussed. Special attention is paid to those parameters affecting GFAAS analysis. Main issues found when coupling LPME and GFAAS, as well as those strategies reported in the literature to solve them, are summarized. Relevant applications published on the topic so far are included. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Directed self-assembly of liquid crystalline blue-phases into ideal single-crystals

    Science.gov (United States)

    Martínez-González, Jose A.; Li, Xiao; Sadati, Monirosadat; Zhou, Ye; Zhang, Rui; Nealey, Paul F.; de Pablo, Juan J.

    2017-06-01

    Chiral nematic liquid crystals are known to form blue phases--liquid states of matter that exhibit ordered cubic arrangements of topological defects. Blue-phase specimens, however, are generally polycrystalline, consisting of randomly oriented domains that limit their performance in applications. A strategy that relies on nano-patterned substrates is presented here for preparation of stable, macroscopic single-crystal blue-phase materials. Different template designs are conceived to exert control over different planes of the blue-phase lattice orientation with respect to the underlying substrate. Experiments are then used to demonstrate that it is indeed possible to create stable single-crystal blue-phase domains with the desired orientation over large regions. These results provide a potential avenue to fully exploit the electro-optical properties of blue phases, which have been hindered by the existence of grain boundaries.

  4. E-T phase diagram of an antiferroelectric liquid crystal with re-entrand smectic C* phase

    Czech Academy of Sciences Publication Activity Database

    Na, Y.-H.; Naruse, Y.; Fukuda, N.; Orihara, H.; Fajar, A.; Hamplová, Věra; Kašpar, Miroslav; Glogarová, Milada

    2008-01-01

    Roč. 364, č. 1 (2008), s. 13-19 ISSN 0015-0193 Institutional research plan: CEZ:AV0Z10100520 Keywords : phase diagram * liquid crystals * dielectric measurements * electric field Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.562, year: 2008

  5. A numerical study of aerosol influence on mixed-phase stratiform clouds through modulation of the liquid phase

    Directory of Open Access Journals (Sweden)

    G. de Boer

    2013-02-01

    Full Text Available Numerical simulations were carried out in a high-resolution two-dimensional framework to increase our understanding of aerosol indirect effects in mixed-phase stratiform clouds. Aerosol characteristics explored include insoluble particle type, soluble mass fraction, influence of aerosol-induced freezing point depression and influence of aerosol number concentration. Simulations were analyzed with a focus on the processes related to liquid phase microphysics, and ice formation was limited to droplet freezing. Of the aerosol properties investigated, aerosol insoluble mass type and its associated freezing efficiency was found to be most relevant to cloud lifetime. Secondary effects from aerosol soluble mass fraction and number concentration also alter cloud characteristics and lifetime. These alterations occur via various mechanisms, including changes to the amount of nucleated ice, influence on liquid phase precipitation and ice riming rates, and changes to liquid droplet nucleation and growth rates. Alteration of the aerosol properties in simulations with identical initial and boundary conditions results in large variability in simulated cloud thickness and lifetime, ranging from rapid and complete glaciation of liquid to the production of long-lived, thick stratiform mixed-phase cloud.

  6. Gas holdup in a reciprocating plate bioreactor: Non-Newtonian - liquid phase

    Directory of Open Access Journals (Sweden)

    Naseva Olivera S.

    2002-01-01

    Full Text Available The gas holdup was studied in non-newtonian liquids in a gas-liquid and gas-liquid-solid reciprocating plate bioreactor. Aqueous solutions of carboxy methyl cellulose (CMC; Lucel, Lučane, Yugoslavia of different degrees of polymerization (PP 200 and PP 1000 and concentration (0,5 and 1%, polypropylene spheres (diameter 8.3 mm; fraction of spheres: 3.8 and 6.6% by volume and air were used as the liquid, solid and gas phase. The gas holdup was found to be dependent on the vibration rate, the superficial gas velocity, volume fraction of solid particles and Theological properties of the liquid ohase. Both in the gas-liquid and gas-liquid-solid systems studied, the gas holdup increased with increasing vibration rate and gas flow rate. The gas holdup was higher in three-phase systems than in two-phase ones under otter operating conditions being the same. Generally the gas holdup increased with increasing the volume fraction of solid particles, due to the dispersion action of the solid particles, and decreased with increasing non-Newtonian behaviour (decreasing flow index i.e. with increasing degree of polymerization and solution concentration of CMC applied, as a result of gas bubble coalescence.

  7. Processes that generate and deplete liquid water and snow in thin midlevel mixed-phase clouds

    Science.gov (United States)

    Smith, Adam J.; Larson, Vincent E.; Niu, Jianguo; Kankiewicz, J. Adam; Carey, Lawrence D.

    2009-06-01

    This paper uses a numerical model to investigate microphysical, radiative, and dynamical processes in mixed-phase altostratocumulus clouds. Three cloud cases are chosen for study, each of which was observed by aircraft during the fifth or ninth Complex Layered Cloud Experiment (CLEX). These three clouds are numerically modeled using large-eddy simulation (LES). The observed and modeled clouds consist of a mixed-phase layer with a quasi-adiabatic profile of liquid, and a virga layer below that consists of snow. A budget of cloud (liquid) water mixing ratio is constructed from the simulations. It shows that large-scale ascent/descent, radiative cooling/heating, turbulent transport, and microphysical processes are all significant. Liquid is depleted indirectly via depositional growth of snow (the Bergeron-Findeisen process). This process is more influential than depletion of liquid via accretional growth of snow. Also constructed is a budget of snow mixing ratio, which turns out to be somewhat simpler. It shows that snow grows by deposition in and below the liquid (mixed-phase) layer, and sublimates in the remainder of the virga region below. The deposition and sublimation are balanced primarily by sedimentation, which transports the snow from the growth region to the sublimation region below. In our three clouds, the vertical extent of the virga layer is influenced more by the profile of saturation ratio below the liquid (mixed-phase) layer than by the mixing ratio of snow at the top of the virga layer.

  8. Return and Liquidity Relationships on Market and Accounting Levels in Brazil

    OpenAIRE

    Perobelli,Fernanda Finotti Cordeiro; Famá,Rubens; Sacramento,Luiz Claudio

    2016-01-01

    ABSTRACT This article discusses profitability-liquidity relationships on accounting and market levels for 872 shares of publicly-traded Brazilian companies, observed between 1994 and 2013. On the market level, the assumption is that share liquidity is able to reduce some of the risks incurred by investors, making them more willing to pay a higher price for liquid shares, which would lower expected market returns. On the accounting level, the basic hypothesis argues that a firm's holding more ...

  9. Dimple coalescence and liquid droplets distributions during phase separation in a pure fluid under microgravity.

    Science.gov (United States)

    Oprisan, Ana; Oprisan, Sorinel A; Hegseth, John J; Garrabos, Yves; Lecoutre-Chabot, Carole; Beysens, Daniel

    2014-09-01

    Phase separation has important implications for the mechanical, thermal, and electrical properties of materials. Weightless conditions prevent buoyancy and sedimentation from affecting the dynamics of phase separation and the morphology of the domains. In our experiments, sulfur hexafluoride (SF6) was initially heated about 1K above its critical temperature under microgravity conditions and then repeatedly quenched using temperature steps, the last one being of 3.6 mK, until it crossed its critical temperature and phase-separated into gas and liquid domains. Both full view (macroscopic) and microscopic view images of the sample cell unit were analyzed to determine the changes in the distribution of liquid droplet diameters during phase separation. Previously, dimple coalescences were only observed in density-matched binary liquid mixture near its critical point of miscibility. Here we present experimental evidences in support of dimple coalescence between phase-separated liquid droplets in pure, supercritical, fluids under microgravity conditions. Although both liquid mixtures and pure fluids belong to the same universality class, both the mass transport mechanisms and their thermophysical properties are significantly different. In supercritical pure fluids the transport of heat and mass are strongly coupled by the enthalpy of condensation, whereas in liquid mixtures mass transport processes are purely diffusive. The viscosity is also much smaller in pure fluids than in liquid mixtures. For these reasons, there are large differences in the fluctuation relaxation time and hydrodynamics flows that prompted this experimental investigation. We found that the number of droplets increases rapidly during the intermediate stage of phase separation. We also found that above a cutoff diameter of about 100 microns the size distribution of droplets follows a power law with an exponent close to -2, as predicted from phenomenological considerations.

  10. Flow measurement in two-phase (gas-liquid) systems

    International Nuclear Information System (INIS)

    Hewitt, G.F.; Whalley, P.B.

    1980-01-01

    The main methods of measuring mass flow and quality in gas-liquid flows in industrial situations are reviewed. These include gamma densitometry coupled with differential pressure devices such as crifice plates, turbine flow meters and drag screens. For each method the principle of operation, and the advantages and disadvantages, are given. Some further techniques which are currently being investigated and developed for routine use are also described briefly. Finally the detailed flow measurements possible on a particular flow pattern - annular flow - is examined. (author)

  11. In Situ Environmental TEM in Imaging Gas and Liquid Phase Chemical Reactions for Materials Research.

    Science.gov (United States)

    Wu, Jianbo; Shan, Hao; Chen, Wenlong; Gu, Xin; Tao, Peng; Song, Chengyi; Shang, Wen; Deng, Tao

    2016-11-01

    Gas and liquid phase chemical reactions cover a broad range of research areas in materials science and engineering, including the synthesis of nanomaterials and application of nanomaterials, for example, in the areas of sensing, energy storage and conversion, catalysis, and bio-related applications. Environmental transmission electron microscopy (ETEM) provides a unique opportunity for monitoring gas and liquid phase reactions because it enables the observation of those reactions at the ultra-high spatial resolution, which is not achievable through other techniques. Here, the fundamental science and technology developments of gas and liquid phase TEM that facilitate the mechanistic study of the gas and liquid phase chemical reactions are discussed. Combined with other characterization tools integrated in TEM, unprecedented material behaviors and reaction mechanisms are observed through the use of the in situ gas and liquid phase TEM. These observations and also the recent applications in this emerging area are described. The current challenges in the imaging process are also discussed, including the imaging speed, imaging resolution, and data management. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Study of phase separation in liquid-liquid systems using LIX 984N in organic phase; Estudio de separacion de fases en sistemas liquido-liquido usando LIX 984N en fase organica

    Energy Technology Data Exchange (ETDEWEB)

    Castillo-Segura, J.; Biela-Cornejo, F.; Navarro-Donoso, P.

    2012-11-01

    In this work we studied the sedimentation and coalescence phenomena in liquid-liquid dispersion without chemical reaction, the aqueous electrolyte consisted of 0.25 M sodium sulfate and an organic phase characteristic organic extractant for copper (LIX 984N) diluted in a commercial solvent (Shellsol 24 AR). The phenomena that dominate the phase separation have been studied by several researchers, which proposed a number of models to predict sedimentation and coalescence profiles. In this work we applied a semi-empirical model to describe the phenomena involved, varying the following experimental conditions: percentage of extractant in organic phase (5 - 30 % v / v), continuous phase (aqueous and organic), time and stirring speed (30 - 1800 s and 400 - 1200 rpm respectively). The main results show that from the 800 rpm of agitation this variable has no influence on primary breakup time, in the same way for 180 seconds of stirring produces the same effect. The fraction of dispersed phase in the packing zone found was 0.74. For higher levels of percentage of extractant in organic phase increased the phase separation time as when the organic phase was used as the continuous phase relative to the aqueous phase. We found a partial adjustment of the experimental data in relation to the simulated values , which is attributable to two factors: the initial inertia of the system once the agitation stopped and the existence of different times of inflection points of the curves of sedimentation and coalescence. In the different articles found in literature assume that the above phenomena occur simultaneously. (Author) 16 refs.

  13. Partitioning of high level liquid waste: experiences in plant level adoption

    International Nuclear Information System (INIS)

    Manohar, Smitha; Kaushik, C.P.

    2016-01-01

    High Level Radioactive Wastes are presently vitrified in borosilicate matrices in all our back end facilities in our country. This is in accordance with internationally endorsed methodology for the safe management of high level radioactive wastes. Recent advancements in the field of partitioning technology in our group, has presented us with an opportunity to have a fresh perspective on management of high level liquid radioactive wastes streams, that emanate from reprocessing operations. This paper will highlight our experiences with respect to both partitioning studies and vitrification practices, with a focus on waste volume reduction for final disposal. Incorporation of this technique has led to the implementation of the concept of recovering wealth from waste, a marked decrease on the load of disposal in deep geological repositories and serve as a step towards the vision of transmutation of long lived radionuclides

  14. Selection of liquid-level monitoring method for the Oak Ridge National Laboratory inactive liquid low-level waste tanks, remedial investigation/feasibility study

    International Nuclear Information System (INIS)

    1994-11-01

    Several of the inactive liquid low-level waste (LLLW) tanks at Oak Ridge National Laboratory contain residual wastes in liquid or solid (sludge) form or both. A plan of action has been developed to ensure that potential environmental impacts from the waste remaining in the inactive LLLW tank systems are minimized. This document describes the evaluation and selection of a methodology for monitoring the level of the liquid in inactive LLLW tanks. Criteria are established for comparison of existing level monitoring and leak testing methods; a preferred method is selected and a decision methodology for monitoring the level of the liquid in the tanks is presented for implementation. The methodology selected can be used to continuously monitor the tanks pending disposition of the wastes for treatment and disposal. Tanks that are empty, are scheduled to be emptied in the near future, or have liquid contents that are very low risk to the environment were not considered to be candidates for installing level monitoring. Tanks requiring new monitoring equipment were provided with conductivity probes; tanks with existing level monitoring instrumentation were not modified. The resulting data will be analyzed to determine inactive LLLW tank liquid level trends as a function of time

  15. Effect of temperature gradient on liquid-liquid phase separation in a polyolefin blend.

    Science.gov (United States)

    Jiang, Hua; Dou, Nannan; Fan, Guoqiang; Yang, Zhaohui; Zhang, Xiaohua

    2013-09-28

    We have investigated experimentally the structure formation processes during phase separation via spinodal decomposition above and below the spinodal line in a binary polymer blend system exposed to in-plane stationary thermal gradients using phase contrast optical microscopy and temperature gradient hot stage. Below the spinodal line there is a coupling of concentration fluctuations and thermal gradient imposed by the temperature gradient hot stage. Also under the thermal gradient annealing phase-separated domains grow faster compared with the system under homogeneous temperature annealing on a zero-gradient or a conventional hot stage. We suggest that the in-plane thermal gradient accelerates phase separation through the enhancement in concentration fluctuations in the early and intermediate stages of spinodal decomposition. In a thermal gradient field, the strength of concentration fluctuation close to the critical point (above the spinodal line) is strong enough to induce phase separation even in one-phase regime of the phase diagram. In the presence of a temperature gradient the equilibrium phase diagrams are no longer valid, and the systems with an upper critical solution temperature can be quenched into phase separation by applying the stationary temperature gradient. The in-plane temperature gradient drives enhanced concentration fluctuations in a binary polymer blend system above and below the spinodal line.

  16. Chromonic liquid crystalline nematic phase exhibited in binary mixture of two liquid crystals

    Energy Technology Data Exchange (ETDEWEB)

    Govindaiah, T. N., E-mail: tngovi.phy@gmail.com; Sreepad, H. R. [Post-Graduate Department of Physics, Government College (Autonomous), Mandya-571401 (India); Sridhar, K. N.; Sridhara, G. R.; Nagaraja, N. [Government College for Boys, Kolar-563101 (India)

    2015-06-24

    A binary mixture of abietic acid and orthophosphoric acid (H{sub 3}PO{sub 4}) exhibits co-existence of biphasic region of Nematic+Isotropic (N+I), lyotropic Nematic (ND) and Smectic-G (SmG) phases. The mixture exhibits N+I, N and SmG phases at different concentrations and at different temperatures. Mixtures with all concentrations of abietic acid exhibit I→N+I→N→SmG phases sequentially when the specimen is cooled from its isotropic melt. These phases have been characterized by using differential scanning calorimetric, X-ray diffraction, and optical texture studies.

  17. Behavior of pumps conveying two-phase liquid flow

    International Nuclear Information System (INIS)

    Grison, Pierre; Lauro, J.-F.

    1979-01-01

    Determination of the two-phase flow (critical or otherwise) through a pump is an essential requirement for complete description of a loss of primary coolant accident in a PWR plant. Theoretical and experimental research at Electricite de France on this subject is described and problems associated with the introduction of a two-phase fluid (with mass transfer) are discussed, with an attempt to single out new phenomena involved and establish their effect on pump behavior. A complementary experimental investigation is described and the results of tests at pressures and temperatures up to 120 bars and 320 0 C respectively are compared with the theoretical model data [fr

  18. Behavior of pumps conveying two-phase liquid flow

    Energy Technology Data Exchange (ETDEWEB)

    Grison, P; Lauro, J F [Electricite de France, 78 - Chatou. Direction des Etudes et Recherches

    1979-01-01

    Determination of the two-phase flow (critical or otherwise) through a pump is an essential requirement for complete description of a loss of primary coolant accident in a PWR plant. Theoretical and experimental research at Electricite de France on this subject is described and problems associated with the introduction of a two-phase fluid (with mass transfer) are discussed, with an attempt to single out new phenomena involved and establish their effect on pump behavior. A complementary experimental investigation is described and the results of tests at pressures and temperatures up to 120 bars and 320/sup 0/C respectively are compared with the theoretical model data.

  19. NMR study of hyper-polarized 129Xe and applications to liquid-phase NMR experiments

    International Nuclear Information System (INIS)

    Marion, D.

    2008-07-01

    In liquid samples where both nuclear polarization and spin density are strong, the magnetization dynamics, which can be analysed by NMR (nuclear magnetic resonance) methods, is deeply influenced by the internal couplings induced by local dipolar fields. The present thesis describes some of the many consequences associated to the presence in the sample of concentrated xenon hyper-polarized by an optical pumping process. First, we deal with the induced modifications in frequency and line width of the proton and xenon spectra, then we present the results of SPIDER, a coherent polarization transfer experiment designed to enhance the polarization of protons, in order to increase their NMR signal level. A third part is dedicated to the description of the apparition of repeated chaotic maser emissions by un unstable xenon magnetization coupled to the detection coil tuned at the xenon Larmor frequency (here 138 MHz). In the last part, we present a new method allowing a better tuning of any NMR detection probe and resulting in sensible gains in terms of sensitivity and signal shaping. Finally, we conclude with a partial questioning of the classical relaxation theory in the specific field of highly polarized and concentrated spin systems in a liquid phase. (author)

  20. Analysis of trace dicyandiamide in stream water using solid phase extraction and liquid chromatography UV spectrometry.

    Science.gov (United States)

    Qiu, Huidong; Sun, Dongdi; Gunatilake, Sameera R; She, Jinyan; Mlsna, Todd E

    2015-09-01

    An improved method for trace level quantification of dicyandiamide in stream water has been developed. This method includes sample pretreatment using solid phase extraction. The extraction procedure (including loading, washing, and eluting) used a flow rate of 1.0mL/min, and dicyandiamide was eluted with 20mL of a methanol/acetonitrile mixture (V/V=2:3), followed by pre-concentration using nitrogen evaporation and analysis with high performance liquid chromatography-ultraviolet spectroscopy (HPLC-UV). Sample extraction was carried out using a Waters Sep-Pak AC-2 Cartridge (with activated carbon). Separation was achieved on a ZIC(®)-Hydrophilic Interaction Liquid Chromatography (ZIC-HILIC) (50mm×2.1mm, 3.5μm) chromatography column and quantification was accomplished based on UV absorbance. A reliable linear relationship was obtained for the calibration curve using standard solutions (R(2)>0.999). Recoveries for dicyandiamide ranged from 84.6% to 96.8%, and the relative standard deviations (RSDs, n=3) were below 6.1% with a detection limit of 5.0ng/mL for stream water samples. Copyright © 2015. Published by Elsevier B.V.

  1. Phase transition detection by surface photo charge effect in liquid crystals

    Science.gov (United States)

    Ivanov, O.; Petrov, M.; Naradikian, H.; Perez-Diaz, J. L.

    2018-05-01

    The surface photo charge effect (SPCE) was applied for the first time at structure and phase transitions study of hydrogen bonded in dimer liquid crystals (HBDLCs). Due to the high sensitivity of this method, besides first-order phase transitions, characteristic for the p,n-octyloxibenzoic acids (8OBA), an order transition was definitely detected within the nematic range. We state that the SPCE, arising at the solid-HBDLCs interface due to the double electrical layer, is invariably concomitant with solid surface-liquid interfaces, and indicates that the changes of the characteristics of this layer, under incident optical irradiation, induce surface charge rearrangement and alternating potential difference. A mechanism of induction of the SPCE at the interface of solid surface-anisotropic liquids is proposed. We also indicate that this mechanism can be adapted for solid surface-isotropic liquid interface, including colloids (milk) and fog (aerosols)-condensed medium.

  2. Liquid phase conversion of Glycerol to Propanediol over highly ...

    Indian Academy of Sciences (India)

    characterization results showed that the copper metal was well-dispersed over MgO support and a new phase. Cu-MgO was ... Currently propanediols are produced from petroleum derivatives .... of MgO.15 Barret-Joyner-Halenda (BJH) method is applied to ..... number of available Cu sites with respect to glycerol as. 0.8. 1.0.

  3. Ionic liquids. Combination of combustion calorimetry with high-level quantum chemical calculations for deriving vaporization enthalpies.

    Science.gov (United States)

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

    2008-07-10

    In this work, the molar enthalpies of formation of the ionic liquids [C2MIM][NO3] and [C4MIM][NO3] were measured by means of combustion calorimetry. The molar enthalpy of fusion of [C2MIM][NO3] was measured using differential scanning calorimetry. Ab initio calculations of the enthalpy of formation in the gaseous phase have been performed for the ionic species using the G3MP2 theory. We have used a combination of traditional combustion calorimetry with modern high-level ab initio calculations in order to obtain the molar enthalpies of vaporization of a series of the ionic liquids under study.

  4. Characterizing the correlations between local phase fractions of gas-liquid two-phase flow with wire-mesh sensor.

    Science.gov (United States)

    Tan, C; Liu, W L; Dong, F

    2016-06-28

    Understanding of flow patterns and their transitions is significant to uncover the flow mechanics of two-phase flow. The local phase distribution and its fluctuations contain rich information regarding the flow structures. A wire-mesh sensor (WMS) was used to study the local phase fluctuations of horizontal gas-liquid two-phase flow, which was verified through comparing the reconstructed three-dimensional flow structure with photographs taken during the experiments. Each crossing point of the WMS is treated as a node, so the measurement on each node is the phase fraction in this local area. An undirected and unweighted flow pattern network was established based on connections that are formed by cross-correlating the time series of each node under different flow patterns. The structure of the flow pattern network reveals the relationship of the phase fluctuations at each node during flow pattern transition, which is then quantified by introducing the topological index of the complex network. The proposed analysis method using the WMS not only provides three-dimensional visualizations of the gas-liquid two-phase flow, but is also a thorough analysis for the structure of flow patterns and the characteristics of flow pattern transition. This article is part of the themed issue 'Supersensing through industrial process tomography'. © 2016 The Author(s).

  5. Characterizing the correlations between local phase fractions of gas–liquid two-phase flow with wire-mesh sensor

    Science.gov (United States)

    Liu, W. L.; Dong, F.

    2016-01-01

    Understanding of flow patterns and their transitions is significant to uncover the flow mechanics of two-phase flow. The local phase distribution and its fluctuations contain rich information regarding the flow structures. A wire-mesh sensor (WMS) was used to study the local phase fluctuations of horizontal gas–liquid two-phase flow, which was verified through comparing the reconstructed three-dimensional flow structure with photographs taken during the experiments. Each crossing point of the WMS is treated as a node, so the measurement on each node is the phase fraction in this local area. An undirected and unweighted flow pattern network was established based on connections that are formed by cross-correlating the time series of each node under different flow patterns. The structure of the flow pattern network reveals the relationship of the phase fluctuations at each node during flow pattern transition, which is then quantified by introducing the topological index of the complex network. The proposed analysis method using the WMS not only provides three-dimensional visualizations of the gas–liquid two-phase flow, but is also a thorough analysis for the structure of flow patterns and the characteristics of flow pattern transition. This article is part of the themed issue ‘Supersensing through industrial process tomography’. PMID:27185959

  6. Measurement of vapor-liquid-liquid phase equilibrium-Equipment and results

    DEFF Research Database (Denmark)

    Frost, Michael Grynnerup; von Solms, Nicolas; Richon, Dominique

    2015-01-01

    There exists a need for new accurate and reliable experimental data, preferably with full characterization of all the phases present in equilibrium. The need for high-quality experimental phase equilibrium data is the case for the chemical industry in general. All areas deal with processes whose ...

  7. Validation the quantification of beta emitters activity in urine by scintillation spectrometry in the liquid phase

    International Nuclear Information System (INIS)

    Sierra, I.; Hernandez, C.; Benito, P.; Lopez, C.

    2013-01-01

    In this paper the methodology used in the validation of the technique for quantifying activity of some beta emitters in urine ( 3 H, 1 4C, 3 5S, 3 2P and 9 0Sr) by scintillation spectrometry Liquid Phase (Liquid Scintillation Counting, LSC) is described in bio elimination Laboratory Service CIEMAT Radiation Dosimetry accredited since last year for carrying out assays measure radiation dose based on ISO forth above. (Author)

  8. Lattice Boltzmann simulations of liquid crystalline fluids: active gels and blue phases

    OpenAIRE

    Cates, M. E.; Henrich, O.; Marenduzzo, D.; Stratford, K.

    2010-01-01

    Lattice Boltzmann simulations have become a method of choice to solve the hydrodynamic equations of motion of a number of complex fluids. Here we review some recent applications of lattice Boltzmann to study the hydrodynamics of liquid crystalline materials. In particular, we focus on the study of (a) the exotic blue phases of cholesteric liquid crystals, and (b) active gels - a model system for actin plus myosin solutions or bacterial suspensions. In both cases lattice Boltzmann studies have...

  9. On-line comprehensive two-dimensional normal-phase liquid chromatography × reversed-phase liquid chromatography for preparative isolation of Peucedanum praeruptorum.

    Science.gov (United States)

    Wang, Xin-Yuan; Li, Jia-Fu; Jian, Ya-Mei; Wu, Zhen; Fang, Mei-Juan; Qiu, Ying-Kun

    2015-03-27

    A new on-line comprehensive preparative two-dimensional normal-phase liquid chromatography × reversed-phase liquid chromatography (2D NPLC × RPLC) system was developed for the separation of complicated natural products. It was based on the use of a silica gel packed medium-pressure column as the first dimension and an ODS preparative HPLC column as the second dimension. The two dimensions were connected with normal-phase (NP) and reversed-phase (RP) enrichment units, involving a newly developed airflow assisted adsorption (AAA) technique. The instrument operation and the performance of this NPLC × RPLC separation method were illustrated by gram-scale isolation of ethanol extract from the roots of Peucedanum praeruptorum. In total, 19 compounds with high purity were obtained via automated multi-step preparative separation in a short period of time using this system, and their structures were comprehensively characterized by ESI-MS, (1)H NMR, and (13)C NMR. Including two new compounds, five isomers in two groups with identical HPLC and TLC retention values were also obtained and identified by 1D NMR and 2D NMR. This is the first report of an NPLC × RPLC system successfully applied in an on-line preparative process. This system not only solved the interfacing problem of mobile-phase immiscibility caused by NP and RP separation, it also exhibited apparent advantages in separation efficiency and sample treatment capacity compared with conventional methods. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Novel materials and methods for solid-phase extraction and liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Ambrose, Diana [Iowa State Univ., Ames, IA (United States)

    1997-06-24

    This report contains a general introduction which discusses solid-phase extraction and solid-phase micro-extraction as sample preparation techniques for high-performance liquid chromatography, which is also evaluated in the study. This report also contains the Conclusions section. Four sections have been removed and processed separately: silicalite as a sorbent for solid-phase extraction; a new, high-capacity carboxylic acid functionalized resin for solid-phase extraction; semi-micro solid-phase extraction of organic compounds from aqueous and biological samples; and the high-performance liquid chromatographic determination of drugs and metabolites in human serum and urine using direct injection and a unique molecular sieve.

  11. Stability analysis of whirling composite shells partially filled with two liquid phases

    Energy Technology Data Exchange (ETDEWEB)

    Sahebnasagh, Mohammad [Department of Mechanical Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Nikkhah-Bahrami, Mansour; Firouz-Abadi, Roohollah [Department of Aerospace Engineering, Sharif University, Tehran (Iran, Islamic Republic of)

    2017-05-15

    In this paper, the stability of whirling composite cylindrical shells partially filled with two liquid phases is studied. Using the first-order shear shell theory, the structural dynamics of the shell is modeled and based on the Navier-Stokes equations for ideal liquid, a 2D model is developed for liquid motion at each section of the cylinder. In steady state condition, liquids are supposed to locate according to mass density. In this study, the thick shells are investigated. Using boundary conditions between liquids, the model of coupled fluid-structure system is obtained. This coupled fluid-structure model is employed to determine the critical speed of the system. The effects of the main variables on the stability of the shell are studied and the results are investigated.

  12. Heat transfer characteristics of liquid-gas Taylor flows incorporating microencapsulated phase change materials

    International Nuclear Information System (INIS)

    Howard, J A; Walsh, P A

    2014-01-01

    This paper presents an investigation on the heat transfer characteristics associated with liquid-gas Taylor flows in mini channels incorporating microencapsulated phase change materials (MPCM). Taylor flows have been shown to result in heat transfer enhancements due to the fluid recirculation experienced within liquid slugs which is attributable to the alternating liquid slug and gas bubble flow structure. Microencapsulated phase change materials (MPCM) also offer significant potential with increased thermal capacity due to the latent heat required to cause phase change. The primary aim of this work was to examine the overall heat transfer potential associated with combining these two novel liquid cooling technologies. By investigating the local heat transfer characteristics, the augmentation/degradation over single phase liquid cooling was quantified while examining the effects of dimensionless variables, including Reynolds number, liquid slug length and gas void fraction. An experimental test facility was developed which had a heated test section and allowed MPCM-air Taylor flows to be subjected to a constant heat flux boundary condition. Infrared thermography was used to record high resolution experimental wall temperature measurements and determine local heat transfer coefficients from the thermal entrance point. 30.2% mass particle concentration of the MPCM suspension fluid was examined as it provided the maximum latent heat for absorption. Results demonstrate a significant reduction in experimental wall temperatures associated with MPCM-air Taylor flows when compared with the Graetz solution for conventional single phase coolants. Total enhancement in the thermally developed region is observed to be a combination of the individual contributions due to recirculation within the liquid slugs and also absorption of latent heat. Overall, the study highlights the potential heat transfer enhancements that are attainable within heat exchange devices employing MPCM

  13. Compact Raman Lidar Measurement of Liquid and Vapor Phase Water Under the Influence of Ionizing Radiation

    Directory of Open Access Journals (Sweden)

    Shiina Tatsuo

    2016-01-01

    Full Text Available A compact Raman lidar has been developed for studying phase changes of water in the atmosphere under the influence of ionization radiation. The Raman lidar is operated at the wavelength of 349 nm and backscattered Raman signals of liquid and vapor phase water are detected at 396 and 400 nm, respectively. Alpha particles emitted from 241Am of 9 MBq ionize air molecules in a scattering chamber, and the resulting ions lead to the formation of liquid water droplets. From the analysis of Raman signal intensities, it has been found that the increase in the liquid water Raman channel is approximately 3 times as much as the decrease in the vapor phase water Raman channel, which is consistent with the theoretical prediction based on the Raman cross-sections. In addition, the radius of the water droplet is estimated to be 0.2 μm.

  14. 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.

  15. Laser-induced separation of hydrogen isotopes in the liquid phase

    International Nuclear Information System (INIS)

    Beattie, W.; Freund, S.; Holland, R.; Maier, W.

    1980-01-01

    A process for separating hydrogen isotopes which comprises (A) forming a liquid phase of hydrogen-bearing feedstock compound at a temperature at which the spectral features of the feedstock compound are narrow enough or the absorption edges sharp enough to permit spectral features corresponding to the different hydrogen isotopes to be separated to be distinguished, (B) irradiating the liquid phase at said temperature with monochromatic radiation of a first wavelength which selectively or at least preferentially excites those molecules of said feedstock compound containing a first hydrogen isotope, and (C) subjecting the excited molecules to physical or chemical processes or a combination thereof whereby said first hydrogen isotope contained in said excited molecules is separated from other hydrogen isotopes contained in the unexcited molecules in said liquid phase

  16. Void fraction fluctuations in two-phase gas-liquid flow

    International Nuclear Information System (INIS)

    Ulbrich, R.

    1987-01-01

    Designs of the apparatus in which two-phase gas-liquid flow occurs are usually based on the mean value of parameters such as pressure drop and void fraction. The flow of two-phase mixtures generally presents a very complicated flow structure, both in terms of the unsteady formation on the interfacial area and in terms of the fluctuations of the velocity, pressure and other variables within the flow. When the gas void fraction is near 0 or 1 / bubble or dispersed flow regimes / then oscillations of void fraction are very small. The intermittent flow such as plug and slug/ froth is characterized by alternately flow portions of liquid and gas. It influences the change of void fractions in time. The results of experimental research of gas void fraction fluctuations in two-phase adiabatic gas-liquid flow in a vertical pipe are presented

  17. Magnetic resonance velocity imaging of liquid and gas two-phase flow in packed beds.

    Science.gov (United States)

    Sankey, M H; Holland, D J; Sederman, A J; Gladden, L F

    2009-02-01

    Single-phase liquid flow in porous media such as bead packs and model fixed bed reactors has been well studied by MRI. To some extent this early work represents the necessary preliminary research to address the more challenging problem of two-phase flow of gas and liquid within these systems. In this paper, we present images of both the gas and liquid velocities during stable liquid-gas flow of water and SF(6) within a packing of 5mm spheres contained within columns of diameter 40 and 27 mm; images being acquired using (1)H and (19)F observation for the water and SF(6), respectively. Liquid and gas flow rates calculated from the velocity images are in agreement with macroscopic flow rate measurements to within 7% and 5%, respectively. In addition to the information obtained directly from these images, the ability to measure liquid and gas flow fields within the same sample environment will enable us to explore the validity of assumptions used in numerical modelling of two-phase flows.

  18. Influence of ionic conductivity on in-phase and anti-phase motions of antiferroelectric liquid crystals

    International Nuclear Information System (INIS)

    Das, D.; Majumder, T.P.; Ghosh, N.K.

    2014-01-01

    The in-phase and anti-phase motions of antiferroelectric liquid crystals were changed due to the influence of charge density associated with the layer modulation modifying the elastic behaviour. The elastic constant was changed because of the coupling between charge density variation and variation of azimuthal angle (ϕ). We obtained theoretically a modified elastic constant depending on the variation of charge density in both in-phase and anti-phase motions. The theoretically elastic constant decreases with the increase of the coupling coefficient between charge density and in-phase azimuthal angle (ϕ a ). We theoretically accounted the dependence of dielectric strength for both relaxations depending on the effective elastic constant influenced by the presence of charge density and discussed the results with experimental observations

  19. Liquid-liquid phase separation and cluster formation at deposition of metals under inhomogeneous magnetic field

    Science.gov (United States)

    Gorobets, O. Yu; Gorobets, Yu I.; Rospotniuk, V. P.; Grebinaha, V. I.; Kyba, A. A.

    2017-10-01

    The formation and dynamic of expansion and deformation of the liquid-liquid interface of an electrolyte at deposition of metals at the surface of the magnetized steel ball is considered in this paper. The electrochemical processes were investigated in an external magnetic field directed at an arbitrary angle to the force of gravity. These processes are accompanied by the formation of effectively paramagnetic clusters of electrochemical products - magnions. Tyndall effect was used for detection of the presence of magnions near the magnetized steel electrode in a solution. The shape of the interface separating the regions with different concentration of magnions, i.e. different magnetic susceptibilities, was described theoretically based on the equation of hydrostatic equilibrium which takes into account magnetic, hydrostatic and osmotic pressures.

  20. Phase equilibrium in systems with ionic liquids: An example for the downstream process of the Biphasic Acid Scavenging utilizing Ionic Liquids (BASIL) process. Part I: Experimental data

    International Nuclear Information System (INIS)

    Sahandzhieva, Katya; Maurer, Gerd

    2012-01-01

    Highlights: ► Phase equilibrium for a downstream process in sustainable chemical technology. ► Biphasic Acid Scavenging Utilizing Ionic Liquids (BASIL) Process. ► SLE, LLE, and SLLE of (NaCl + water + 1-propanol + 1-MIM) and its ternary subsystems. ► Experimental phase equilibrium data at temperatures between 298 K and 333 K. - Abstract: Experimental results are presented for the (liquid + liquid), (solid + liquid) and (solid + liquid + liquid) equilibria occurring in the downstream process of a typical example for the Biphasic Acid Scavenging Utilizing Ionic Liquids (BASIL)-processes. In a BASIL process an organic base is used to catalyze a chemical reaction and, at the same time, to scavenge an acid that is an undesired side product of that reaction. The particular example of a BASIL process treated here is the reaction of 1-butanol and acetylchloride to butylacetate and hydrochloric acid, where the acid is scavenged by the organic base 1-methyl imidazole (1-MIM) resulting in the ionic liquid 1-methyl imidazolium chloride. The reaction results in a two-phase system as butylacetate and the ionic liquid reveal a large liquid–liquid miscibility gap. The organic base has to be recovered. This is commonly achieved by treating the ionic liquid–rich liquid phase with an aqueous solution of sodium hydroxide (i.e., converting the ionic liquid to the organic base) and extracting the organic base by an appropriate organic solvent (e.g., 1-propanol). The work presented here deals in experimental work with the (liquid + liquid), (solid + liquid) and (solid + liquid + liquid) phase equilibria that are encountered in such extraction processes. Experimental results are reported for temperatures between about 298 K and 333 K: for the solubility of NaCl in several solvents (1-propanol, 1-MIM), (water + 1-MIM), (1-propanol + 1-MIM), (water + 1-propanol), and (water + 1-propanol + 1-MIM) and for the (liquid + liquid) equilibrium as well as for the (solid + liquid

  1. Cold flame on Biofilm - Transport of Plasma Chemistry from Gas to Liquid Phase

    Science.gov (United States)

    Kong, Michael

    2014-10-01

    One of the most active and fastest growing fields in low-temperature plasma science today is biological effects of gas plasmas and their translation in many challenges of societal importance such as healthcare, environment, agriculture, and nanoscale fabrication and synthesis. Using medicine as an example, there are already three FDA-approved plasma-based surgical procedures for tissue ablation and blood coagulation and at least five phase-II clinical trials on plasma-assisted wound healing therapies. A key driver for realizing the immense application potential of near room-temperature ambient pressure gas plasmas, commonly known as cold atmospheric plasmas or CAP, is to build a sizeable interdisciplinary knowledge base with which to unravel, optimize, and indeed design how reactive plasma species interact with cells and their key components such as protein and DNA. Whilst a logical objective, it is a formidable challenge not least since existing knowledge of gas discharges is largely in the gas-phase and therefore not directly applicable to cell-containing matters that are covered by or embedded in liquid (e.g. biofluid). Here, we study plasma inactivation of biofilms, a jelly-like structure that bacteria use to protect themselves and a major source of antimicrobial resistance. As 60--90% of biofilm is made of water, we develop a holistic model incorporating physics and chemistry in the upstream CAP-generating region, a plasma-exit region as a buffer for as-phase transport, and a downstream liquid region bordering the gas buffer region. A special model is developed to account for rapid chemical reactions accompanied the transport of gas-phase plasma species through the gas-liquid interface and for liquid-phase chemical reactions. Numerical simulation is used to illustrate how key reactive oxygen species (ROS) are transported into the liquid, and this is supported with experimental data of both biofilm inactivation using plasmas and electron spin spectroscopy (ESR

  2. Investigation of liquid phase axial dispersion in Taylor bubble flow by radiotracer residence time distribution analysis

    Directory of Open Access Journals (Sweden)

    Jin J.H.

    2013-05-01

    Full Text Available A gas-liquid Taylor bubble flow occurs in small diameter channels in which gas bubbles are separated by slugs of pure liquid. This type of flow regime is well suited for solid catalyzed gas-liquid reactors in which the reaction efficiency is a strong function of axial dispersion in the regions of pure liquid. This paper presents an experimental study of liquid phase axial dispersion in a Taylor bubble flow developed in a horizontal tube using high speed photography and radiotracer residence time distribution (RTD analysis. A parametric dependence of axial dispersion on average volume fraction of gas phase was also investigated by varying the relative volumetric flow rates of the two phases. 137mBa produced from a 137Cs/137mBa radionuclide generator was used as radiotracer and measurements were made using the NaI(Tl scintillation detectors. Validation of 137mBa in the form of barium chloride as aqueous phase radiotracer was also carried out. Axial Dispersion Model (ADM was used to simulate the hydrodynamics of the system and the results of the experiment are presented. It was observed that the system is characterized by very high values of Peclet Number (Pe∼102 which reveals an approaching plug type flow. The experimental and model estimated values of mean residence times were observed in agreement with each other.

  3. High flux diode packaging using passive microscale liquid-vapor phase change

    Science.gov (United States)

    Bandhauer, Todd; Deri, Robert J.; Elmer, John W.; Kotovsky, Jack; Patra, Susant

    2017-09-19

    A laser diode package includes a heat pipe having a fluid chamber enclosed in part by a heat exchange wall for containing a fluid. Wicking channels in the fluid chamber is adapted to wick a liquid phase of the fluid from a condensing section of the heat pipe to an evaporating section of the heat exchanger, and a laser diode is connected to the heat exchange wall at the evaporating section of the heat exchanger so that heat produced by the laser diode is removed isothermally from the evaporating section to the condensing section by a liquid-to-vapor phase change of the fluid.

  4. Purification of inkjet ink from water using liquid phase, electric discharge polymerization and cellulosic membrane filtration.

    Science.gov (United States)

    Jordan, Alexander T; Hsieh, Jeffery S; Lee, Daniel T

    2013-01-01

    A method to separate inkjet ink from water was developed using a liquid phase, electric discharge process. The liquid phase, electric discharge process with filtration or sedimentation was shown to remove 97% of inkjet ink from solutions containing between 0.1-0.8 g/L and was consistent over a range of treatment conditions. Additionally, particle size analysis of treated allyl alcohol and treated propanol confirmed the electric discharge treatment has a polymerization mechanism, and small molecule analysis of treated methanol using gas chromatography and mass spectroscopy confirmed the mechanism was free radical initiated polymerization.

  5. Numerical simulation analysis of four-stage mutation of solid-liquid two-phase grinding

    Science.gov (United States)

    Li, Junye; Liu, Yang; Hou, Jikun; Hu, Jinglei; Zhang, Hengfu; Wu, Guiling

    2018-03-01

    In order to explore the numerical simulation of solid-liquid two-phase abrasive grain polishing and abrupt change tube, in this paper, the fourth order abrupt change tube was selected as the research object, using the fluid mechanics software to simulate,based on the theory of solid-liquid two-phase flow dynamics, study on the mechanism of AFM micromachining a workpiece during polishing.Analysis at different inlet pressures, the dynamic pressure distribution pipe mutant fourth order abrasive flow field, turbulence intensity, discuss the influence of the inlet pressure of different abrasive flow polishing effect.

  6. Liquid sodium testing of in-house phased array EMAT transducer for L-wave applications

    Energy Technology Data Exchange (ETDEWEB)

    Le Bourdais, F.; Le Polles, T. [Non Destructive Testing Department at the French Atomic Energy Commission (CEA), Saclay, 91191 Gif sur Yvette CEDEX, (France); Baque, F. [Department of Sodium Technology at the French Atomic Energy Commission (CEA), Cadarache, 13108 St Paul lez Durance CEDEX, (France)

    2015-07-01

    This paper describes the development of an in-house phased array EMAT transducer for longitudinal wave inspection in liquid sodium. The work presented herein is part of an undergoing project aimed at improving in-service inspection techniques for the ASTRID reactor project. The design process of the phased array EMAT probe is briefly explained and followed by a review of experimental test results. We first present test results obtained in the laboratory while the last part of the paper describes the liquid sodium testing and the produced ultrasound images. (authors)

  7. Liquid sodium testing of in-house phased array EMAT transducer for L-wave applications

    International Nuclear Information System (INIS)

    Le Bourdais, F.; Le Polles, T.; Baque, F.

    2015-01-01

    This paper describes the development of an in-house phased array EMAT transducer for longitudinal wave inspection in liquid sodium. The work presented herein is part of an undergoing project aimed at improving in-service inspection techniques for the ASTRID reactor project. The design process of the phased array EMAT probe is briefly explained and followed by a review of experimental test results. We first present test results obtained in the laboratory while the last part of the paper describes the liquid sodium testing and the produced ultrasound images. (authors)

  8. Local preparation and evaluation of liquid phase radioimmunoassay for determination of human serum cortisol

    International Nuclear Information System (INIS)

    Sallam, Kh.M.; El-Bayoumy, A.S.A.; Ebeid, N.H.; Michael, E.; Zein, N.; Elfarargy, Ah.F.

    2017-01-01

    The main objective of the present study was the preparation of the primary reagents of cortisol radioimmunoassay (RIA) using liquid phase double antibody technique. Three basic components were prepared and characterized to obtain valid and accurate system. These components were polyclonal anti-cortisol antibody, "1"2"5I-cortisol RIA tracer and cortisol standards. Cortisol requires conjugation step to be real antigen. Therefore, in this study this mandatory conjugation step was performed & characterized. Then formulation, optimization and validation of this liquid phase RIA technique were carried out. This assay is precise, specific and sensitive enough for using as a diagnostic tool for the adrenal cortex status. (author)

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

    Science.gov (United States)

    Volodin, V. N.

    2009-11-01

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

  10. Liquid-gas phase transition in asymmetric nuclear matter at finite temperature

    International Nuclear Information System (INIS)

    Maruyama, Toshiki; Tatsumi, Toshitaka; Chiba, Satoshi

    2010-01-01

    Liquid-gas phase transition is discussed in warm asymmetric nuclear matter. Some peculiar features are figured out from the viewpoint of the basic thermodynamics about the phase equilibrium. We treat the mixed phase of the binary system based on the Gibbs conditions. When the Coulomb interaction is included, the mixed phase is no more uniform and the sequence of the pasta structures appears. Comparing the results with those given by the simple bulk calculation without the Coulomb interaction, we extract specific features of the pasta structures at finite temperature.

  11. Liquid-gas phase transition in asymmetric nuclear matter at finite temperature

    Science.gov (United States)

    Maruyama, Toshiki; Tatsumi, Toshitaka; Chiba, Satoshi

    2010-03-01

    Liquid-gas phase transition is discussed in warm asymmetric nuclear matter. Some peculiar features are figured out from the viewpoint of the basic thermodynamics about the phase equilibrium. We treat the mixed phase of the binary system based on the Gibbs conditions. When the Coulomb interaction is included, the mixed phase is no more uniform and the sequence of the pasta structures appears. Comparing the results with those given by the simple bulk calculation without the Coulomb interaction, we extract specific features of the pasta structures at finite temperature.

  12. Nonionic diethanolamide amphiphiles with isoprenoid-type hydrocarbon chains: thermotropic and lyotropic liquid crystalline phase behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Sagnella, Sharon M.; Conn, Charlotte E.; Krodkiewska, Irena; Drummond, Calum J. (CSIRO/MSE)

    2014-09-24

    The thermotropic and lyotropic liquid crystalline phase behaviour of a series of diethanolamide amphiphiles with isoprenoid-type hydrocarbon chains (geranoyl, H-farnesoyl, and phytanoyl) has been investigated. When neat, both H-farnesoyl and phytanoyl diethanolamide form a smectic liquid crystalline structure at sub-zero temperatures. In addition, all three diethanolamides exhibit a glass transition temperature at around -73 C. Geranoyl diethanolamide forms a lamellar crystalline phase with a lattice parameter of 17.4 {angstrom} following long term storage accompanied by the loss of the glass transition. In the presence of water, H-farnesoyl and phytanoyl diethanolamide form lyotropic liquid crystalline phases, whilst geranoyl diethanolamide forms an L{sub 2} phase. H-farnesoyl diethanolamide forms a fluid lamellar phase (L{sub {alpha}}) at room temperature and up to {approx} 40 C. Phytanoyl diethanolamide displays a rich mesomorphism forming the inverse diamond (Q{sub II}{sup D}) and gyroid (Q{sub II}{sup G}) bicontinuous cubic phases in addition to an L{sub {alpha}} phase.

  13. ASRDI oxygen technology survey. Volume 5: Density and liquid level measurement instrumentation for the cryogenic fluids oxygen, hydrogen, and nitrogen

    Science.gov (United States)

    Roder, H. M.

    1974-01-01

    Information is presented on instrumentation for density measurement, liquid level measurement, quantity gauging, and phase measurement. Coverage of existing information directly concerned with oxygen was given primary emphasis. A description of the physical principle of measurement for each instrumentation type is included. The basic materials of construction are listed if available from the source document for each instrument discussed. Cleaning requirements, procedures, and verification techniques are included.

  14. Modern Aspects Of Fluorometric Detection In Liquid-Phase Chromatography

    Science.gov (United States)

    Bousquet, Bernard; Garnier, Jean P.; Dreux, Claude

    1983-10-01

    Recent advances are described in the combined use of fluorometric derivatization and high performance liquid chromatography (HPLC) for clinical chemistry determinations. Derivatives (especially dansyl derivatives) can be formed prior to chromatography in the case of estrogens, amino acids, and catecholamines. In post-column reactions, we preferred to use air-segmented reactions as they conform better to all the optimized chromatographic and spectrofluorometric parameters. Fluorescent derivatives produced from cate-cholamines, tryptophan and its metabolites, hydroxyindoles, tryptamine, amino acids, sugars, polyamines, and other substances are often sufficiently sensitive to be detected in picogram quantities by HPLC. Their reaction principle and some of their applications to samples are described. Recently, chemical excitation of fluorophore-like dansyl amino acid was proposed as a detection system for HPLC. By a post-column reaction, a fluorophore can be made to emit light by its reaction with trichlorophenyl oxalate (TCPO) and hydrogen peroxide. The detection limit of this system is about 10 fmol for each dansyl amino acid. Application of this new reaction to catecholamines opens up new prospects for fluorometric detection.

  15. Aspirin locally disrupts the liquid-ordered phase

    Science.gov (United States)

    Alsop, Richard J.; Himbert, Sebastian; Dhaliwal, Alexander; Schmalzl, Karin; Rheinstädter, Maikel C.

    2018-02-01

    Local structure and dynamics of lipid membranes play an important role in membrane function. The diffusion of small molecules, the curvature of lipids around a protein and the existence of cholesterol-rich lipid domains (rafts) are examples for the membrane to serve as a functional interface. The collective fluctuations of lipid tails, in particular, are relevant for diffusion of membrane constituents and small molecules in and across membranes, and for structure and formation of membrane domains. We studied the effect of aspirin (acetylsalicylic acid, ASA) on local structure and dynamics of membranes composed of dimyristoylphosphocholine (DMPC) and cholesterol. Aspirin is a common analgesic, but is also used in the treatment of cholesterol. Using coherent inelastic neutron scattering experiments and molecular dynamics (MD) simulations, we present evidence that ASA binds to liquid-ordered, raft-like domains and disturbs domain organization and dampens collective fluctuations. By hydrogen-bonding to lipid molecules, ASA forms `superfluid' complexes with lipid molecules that can organize laterally in superlattices and suppress cholesterol's ordering effect.

  16. Formation, structure, and evolution of boiling nucleus and interfacial tension between bulk liquid phase and nucleus

    Science.gov (United States)

    Wang, Xiao-Dong; Peng, Xiao-Feng; Tian, Yong; Wang, Bu-Xuan

    2005-05-01

    In this paper, the concept of the molecular free path is introduced to derive a criterion distinguishing active molecules from inactive molecules in liquid phase. A concept of the critical aggregation concentration (CAC) of active molecules is proposed to describe the physical configuration before the formation of a nucleus during vapor-liquid phase transition. All active molecules exist as monomers when the concentration of active molecules is lower than CAC, while the active molecules will generate aggregation once the concentration of the active molecules reaches CAC. However, these aggregates with aggregation number, N, smaller than five can steadily exist in bulk phase. The other excess active molecules can only produce infinite aggregation and form a critical nucleus of vapor-liquid phase transition. Without any outer perturbation the state point of CAC corresponds to the critical superheated or supercooled state. Meanwhile, a model of two-region structure of a nucleus is proposed to describe nucleus evolution. The interfacial tension between bulk liquid phase and nucleus is dependent of the density gradient in the transition region and varies with the structure change of the transition region. With the interfacial tension calculated using this model, the predicted nucleation rate is very close to the experimental measurement. Furthermore, this model and associated analysis provides solid theoretical evidences to clarify the definition of nucleation rate and understand nucleation phenomenon with the insight into the physical nature.

  17. Symmetry protected topological Luttinger liquids and the phase transition between them

    Energy Technology Data Exchange (ETDEWEB)

    None

    2018-01-01

    We show that a doped spin-1/2 ladder with antiferromagnetic intra-chain and ferromagnetic inter-chain coupling is a symmetry protected topologically non-trivial Luttinger liquid. Turning on a large easy-plane spin anisotropy drives the system to a topologically-trivial Luttinger liquid. Both phases have full spin gaps and exhibit power-law superconducting pair correlation. The Cooper pair symmetry is singlet $d_{xy}$ in the non-trivial phase and triplet $S_z=0$ in the trivial phase. The topologically non-trivial Luttinger liquid exhibits gapless spin excitations in the presence of a boundary, and it has no non-interacting or mean-field theory analog even when the fluctuating phase in the charge sector is pinned. As a function of the strength of spin anisotropy there is a topological phase transition upon which the spin gap closes. We speculate these Luttinger liquids are relevant to the superconductivity in metalized integer spin ladders or chains.

  18. Hollow-fiber liquid-phase microextraction of amphetamine-type stimulants in human hair samples.

    Science.gov (United States)

    do Nascimento Pantaleão, Lorena; Bismara Paranhos, Beatriz Aparecida Passos; Yonamine, Mauricio

    2012-09-07

    A fast method was optimized and validated in order to quantify amphetamine-type stimulants (amphetamine, AMP; methamphetamine, MAMP; fenproporex, FPX; 3,4-methylenedioxymethamphetamine, MDMA; and 3,4-methylenedioxyamphetamine, MDA) in human hair samples. The method was based in an initial procedure of decontamination of hair samples (50 mg) with dichloromethane, followed by alkaline hydrolysis and extraction of the amphetamines using hollow-fiber liquid-phase micro extraction (HF-LPME) in the three-phase mode. Gas chromatography-mass spectrometry (GC-MS) was used for identification and quantification of the analytes. The LoQs obtained for all amphetamines (around 0.05 ng/mg) were below the cut-off value (0.2 ng/mg) established by the Society of Hair Testing (SoHT). The method showed to be simple and precise. The intra-day and inter-day precisions were within 10.6% and 11.4%, respectively, with the use of only two deuterated internal standards (AMP-d5 and MDMA-d5). By using the weighted least squares linear regression (1/x²), the accuracy of the method was satisfied in the lower concentration levels (accuracy values better than 87%). Hair samples collected from six volunteers who reported regular use of amphetamines were submitted to the developed method. Drug detection was observed in all samples of the volunteers. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. Studies on Three Liquid Phase Extraction (TLPE) system for separation of rare earths

    International Nuclear Information System (INIS)

    Yadav, Kartikey K.; Singh, D.K.; Anitha, M.; Singh, H.

    2014-01-01

    Three-liquid-phase extraction (TLPE) is relatively a new separation technique, which takes the advantage of the differences in physicochemical properties of three coexisted phases to achieve multi-phase liquid separation of two or more components in one-step extraction. TLPE system consists of three liquid layers namely an organic solvent phase (organophosphorous type) and two aqueous phases one rich in polymer phase (poly alkylene glycol) and other a salt solution. To study the feasibility of using such system for separation of rare earths, it is important to optimize the preparatory conditions by selective suitable polymer and salt solutions at an appropriate pH to obtain a stable three phase layers to effect the separation. D2EHPA (di-2-ethyl hexyl phosphoric acid) is a well- established extractant in the rare earth industry and has been chosen in the present work to form a TLPE with polymer and salt solution. In the present investigation after preparing the stable three phase, the feasibility of using TLPE has been examined to separate rare earths from a multicomponent solutions. This study has demonstrated the ability of TLPE having D2EHPA as organic phase to separate rare earths from a multicomponent system. Effect of pH, concentration and types of polymer, complexing agent and D2EHPA concentration has been studied. Variation in pH study indicated that 4.0 leads to extraction of rare earths in the polymer phase. PEG 600 was found to be best amongst the polymer investigated. Presence of DTPA as complexing agent in the salt solution having pH >4.0 resulted in enhanced extraction of rare earths in PEG phase

  20. Simulations of electrolytes at the liquid-liquid interface and of lanthanide cations complexes in gas phase

    International Nuclear Information System (INIS)

    Berny, F.

    2000-01-01

    Two processes related to liquid/liquid extraction of ions by extractant molecules were studied: the ion approach at the interface and the ion complexation by ligands. In the first part, the behaviour of salts at the chloroform/water interface was simulated by molecular dynamics. The aim was to understand the way these salts ions approach the interface in order to be extracted. Some ions are repelled by the interface (K + , Cl - , UO 2 2+ , Na + , NO 3 - ) whereas others adsorb (amphiphilic molecules and also ClO 4 - , SCN - , guanidinium Gu + and picrate Pic - ). The surface-active counter-ions make the ion approach at the interface easier. In a perfectly homogeneous mixture of the two solvents (water and chloroform) de-mixing, the ions seem to influence the phases separation rate. Nitric acid which is known to favour liquid/liquid extraction reveals strong adsorption at the interface in its neutral form and a smaller one in its ionic form (H 3 O + /NO 3 - ). HNO 3 and H 3 O + display particular orientations at the interface: hydrogen atoms are pointing in the direction of the water slab. The nature of the organic phase can also influence the ion approach at the interface. For example, Gu + and Pic - adsorb much less at the supercritical CO 2 /water interface than at the chloroform/water interface. In the second part, complexes of La 3+ , Eu 3+ and Yb 3+ with ligands such as amide, urea, thio-amide, thiourea were studied by quantum mechanics. Our calculations show that cation-ligand interactions depend on the nature of substituents on ligands, on the presence of counter-ions or on the number of ligands in the complex. Sulfur compounds seem to less interact with cations than oxygen compounds. Ureas interact as much as amides and are potentially good ligands. (author)

  1. Hollow fiber liquid-phase microextraction of cadmium(II) using an ionic liquid as the extractant

    International Nuclear Information System (INIS)

    Chen, Hui; Wang, Yun; Hu, Yutao; Ni, Liang; Liu, Yingying; Kang, Wenbing; Liu, Yan; Han, Juan

    2014-01-01

    A method is presented for hollow fiber liquid-phase microextraction (HF-LPME) of cadmium(II), which is chelated with 1-(2-pyridylazo)-2-naphthol (PAN) to obtain a hydrophobic complex which then is extracted into a polypropylene hollow fiber containing an ionic liquid in its pores which acts as the membrane phase. EDTA is then injected into the lumen of the membrane as an acceptor phase to trap the analyte. The extraction time (20 min), agitation (400 rpm at 25 °C), pH value (10.0), and the concentrations of PAN (2.5 ng mL −1 ) and EDTA (250 ng mL −1 ) were optimized. With a sample volume of 50 mL and a stripping volume of 15 μL, the enrichment factor is 162. Cadmium(II) was then quantified by graphite furnace AAS. The limit of detection is 0.12 pg mL −1 , the relative standard deviation is 5.2 %, and the linear working range extends from 4 to 45 pg mL −1 . The method was successfully applied to the determination of Cd(II) in environmental and food samples. (author)

  2. On the use of ionic liquids as mobile phase additives in high-performance liquid chromatography. A review.

    Science.gov (United States)

    García-Alvarez-Coque, M C; Ruiz-Angel, M J; Berthod, A; Carda-Broch, S

    2015-07-09

    The popularity of ionic liquids (ILs) has grown during the last decades in several analytical separation techniques. Consequently, the number of reports devoted to the applications of ILs is still increasing. This review is focused on the use of ILs (mainly imidazolium-based associated to chloride and tetrafluoroborate) as mobile phase additives in high-performance liquid chromatography (HPLC). In this approach, ILs just function as salts, but keep several kinds of intermolecular interactions, which are useful for chromatographic separations. Both cation and anion can be adsorbed on the stationary phase, creating a bilayer. This gives rise to hydrophobic, electrostatic and other specific interactions with the stationary phase and solutes, which modify the retention behaviour and peak shape. This review updates the advances in this field, with emphasis on topics not always deeply considered in the literature, such as the mechanisms of retention, the estimation of the suppressing potency of silanols, modelling and optimisation of the chromatographic performance, and the comparison with other additives traditionally used to avoid the silanol problem. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Two-phase gas bubble-liquid boundary layer flow along vertical and inclined surfaces

    International Nuclear Information System (INIS)

    Cheung, F.B.; Epstein, M.

    1985-01-01

    The behavior of a two-phase gas bubble-liquid boundary layer along vertical and inclined porous surfaces with uniform gas injection is investigated experimentally and analytically. Using argon gas and water as the working fluids, a photographical study of the two-phase boundary layer flow has been performed for various angles of inclination ranging from 45 0 to 135 0 and gas injection rates ranging from 0.01 to 0.1 m/s. An integral method has been employed to solve the system of equations governing the two-phase motion. The effects of the gas injection rate and the angle of inclination on the growth of the boundary layer have been determined. The predicted boundary layer thickness is found to be in good agreement with the experimental results. The calculated axial liquid velocity and the void fraction in the two-phase region are also presented along with the observed flow behavior

  4. Probing the nuclear liquid-gas phase transition

    International Nuclear Information System (INIS)

    Pochodzalla, J.; Moehlenkamp, T.; Rubehn, T.; Schuettauf, A.; Zude, E.; Begemann-Blaich, M.; Blaich, T.; Emling, H.; Ferrero, A.; Kunze, W.D.; Lindenstruth, V.; Lynen, U.; Moroni, W.; Ocker, B.; Schwarz, C.; Seidel, W.; Serfling, V.; Trzcinski, A.; Tucholski, A.; Verde, G.

    1995-02-01

    Fragment distributions resulting from Au+Au collisions at an incident energy of E/A=600 MeV are studied. From the measured fragment and neutron distributions the mass and the excitation energy of the decaying pre-fragments were determined. A temperature scale was derived from observed yield ratios of He and Li isotopes. The relation between this isotope temperature and the excitation energy of the system exhibits a behavior which is expected for a phase transition. The nuclear vapor regime takes over at an excitation energy of 10 MeV per nucleon, a temperature of 5 MeV and may be characterized by a density of 0.15-0.3 normal nuclear density. (orig.)

  5. (Liquid + liquid) phase equilibrium and critical behavior of binary solution {heavy water + 2,6-dimethylpyridine}

    International Nuclear Information System (INIS)

    Xu, Chen; Chai, Shouning; Yin, Tianxiang; Chen, Zhiyun; Shen, Weiguo

    2015-01-01

    Highlights: • Coexistence curves, heat capacities and turbidities were measured. • Deuterium effect on coexistence curves was discussed. • Universal critical amplitude ratios were tested. • Asymmetry of coexistence curves was analyzed by the complete scaling theory. - Abstract: The (liquid + liquid) coexistence curves, the isobaric heat capacities per unit volume and the turbidities for the binary solution of {heavy water + 2,6-dimethylpyridine} have been precisely measured. The values of the critical exponents were obtained, which confirmed the 3D-Ising universality. It was found that the critical temperature dropped by 5.9 K and the critical amplitude of the coexistence curve significantly increased as compared to the binary solution of {water + 2,6-dimethylpyridine}. The complete scaling theory was applied to well describe the asymmetric behavior of the diameter of the coexistence curve as the heat capacity contribution was considered. Moreover, the values of the critical amplitudes of the correlation length and the osmotic compressibility were deduced, which together with the critical amplitudes of the coexistence curve and the heat capacity to test universal amplitude ratios

  6. The accuracy of liquid-liquid phase transition temperatures determined from semiautomated light scattering measurements

    Science.gov (United States)

    Dean, Kevin M.; Babayco, Christopher B.; Sluss, Daniel R. B.; Williamson, J. Charles

    2010-08-01

    The synthetic-method determination of liquid-liquid coexistence curves using semiautomated light scattering instrumentation and stirred samples is based on identifying the coexistence curve transition temperatures (Tcx) from sudden changes in turbidity associated with droplet formation. Here we use a thorough set of such measurements to evaluate the accuracy of several different analysis methods reported in the literature for assigning Tcx. More than 20 samples each of weakly opalescent isobutyric acid+water and strongly opalescent aniline+hexane were tested with our instrumentation. Transmitted light and scattering intensities at 2°, 24°, and 90° were collected simultaneously as a function of temperature for each stirred sample, and the data were compared with visual observations and light scattering theory. We find that assigning Tcx to the onset of decreased transmitted light or increased 2° scattering has a potential accuracy of 0.01 K or better for many samples. However, the turbidity due to critical opalescence obscures the identification of Tcx from the light scattering data of near-critical stirred samples, and no simple rule of interpretation can be applied regardless of collection geometry. At best, when 90° scattering is collected along with transmitted or 2° data, the accuracy of Tcx is limited to 0.05 K for near-critical samples. Visual determination of Tcx remains the more accurate approach in this case.

  7. Determination of the mass-transfer coefficient in liquid phase in a stream-bubble contact device

    Science.gov (United States)

    Dmitriev, A. V.; Dmitrieva, O. S.; Madyshev, I. N.

    2016-09-01

    One of the most effective energy saving technologies is the improvement of existing heat and mass exchange units. A stream-bubble contact device is designed to enhance the operation efficiency of heat and mass exchange units. The stages of the stream-bubble units that are proposed by the authors for the decarbonization process comprise contact devices with equivalent sizes, whose number is determined by the required performance of a unit. This approach to the structural design eliminates the problems that arise upon the transition from laboratory samples to industrial facilities and makes it possible to design the units of any required performance without a decrease in the effectiveness of mass exchange. To choose the optimal design that provides the maximum effectiveness of the mass-exchange processes in units and their intensification, the change of the mass-transfer coefficient is analyzed with the assumption of a number of parameters. The results of the study of the effect of various structural parameters of a stream-bubble contact device on the mass-transfer coefficient in the liquid phase are given. It is proven that the mass-transfer coefficient increases in the liquid phase, in the first place, with the growth of the level of liquid in the contact element, because the rate of the liquid run-off grows in this case and, consequently, the time of surface renewal is reduced; in the second place, with an increase in the slot diameter in the downpipe, because the jet diameter and, accordingly, their section perimeter and the area of the surface that is immersed in liquid increase; and, in the third place, with an increase in the number of slots in the downpipe, because the area of the surface that is immersed in the liquid of the contact element increases. Thus, in order to increase the mass-transfer coefficient in the liquid phase, it is necessary to design the contact elements with a minimum width and a large number of slots and their increased diameter; in

  8. The nuclear liquid-gas phase transition: Present status and future perspectives

    International Nuclear Information System (INIS)

    Pochodzalla, J.; Imme, G.; Maddalena, V.

    1996-07-01

    More than two decades ago, the van der Waals behavior of the nucleon -nucleon force inspired the idea of a liquid-gas phase transition in nuclear matter. Heavy-ion reactions at relativistic energies offer the unique possibility for studying this phase transition in a finite, hadronic system. A general overview of this subject is given emphasizing the most recent results on nuclear calorimetry. (orig.)

  9. Liquid-Vapor Phase Transition: Thermomechanical Theory, Entropy Stable Numerical Formulation, and Boiling Simulations

    Science.gov (United States)

    2015-05-01

    vapor bubbles may generate near blades [40]. This is the phenomenon of cavitation and it is still a limiting factor for ship propeller design. Phase...van der Waals theory with hydrodynamics [39]. The fluid equations based on the van der Waals theory are called the Navier-Stokes-Korteweg equations... cavitating flows, the liquid- vapor phase transition induced by pressure variations. A potential challenge for such a simulation is a proper design of open

  10. Surface-induced ordering of a liquid crystal in the isotropic phase

    International Nuclear Information System (INIS)

    Miyano, K.

    1979-01-01

    A detailed account of a measurement of order parameter of a liquid crystal at the boundary by means of the wall-induced pretransitional birefringence is given. Several surface treatments were studied including surfactants and evaporated films. Although all treatments produced good alignment in the nematic phase, the boundary order parameter (hence the strength of the aligning force) in the isotropic phase differed very much depending on the treatment, indicating the diverse nature of the alignment process

  11. Functional design criteria for project W-252, phase II liquid effluent treatment and disposal. Revision 2

    International Nuclear Information System (INIS)

    Hatch, C.E.

    1995-05-01

    This document is the Functional Design Criteria for Project W-252. Project W-252 provides the scope to provide BAT/AKART (best available technology...) to 200 Liquid Effluent Phase II streams (B-Plant). This revision (Rev. 2) incorporates a major descoping of the project. The descoping was done to reflect a combination of budget cutting measures allowed by a less stringent regulatory posture toward the Phase II streams

  12. Isospin and momentum dependence of liquid-gas phase transition in hot asymmetric nuclear matter

    International Nuclear Information System (INIS)

    Xu, Jun; Ma, Hongru; Chen, Liewen; Li, Baoan

    2008-01-01

    The liquid-gas phase transition in hot neutron-rich nuclear matter is investigated within a self-consistent thermal model using different interactions with or without isospin and/or momentum dependence. The boundary of the phase-coexistence region is shown to be sensitive to the density dependence of the nuclear symmetry energy as well as the isospin and momentum dependence of the nuclear interaction. (author)

  13. Dipolar phases in liquid crystals with the chiral part based on the lactic acid

    Czech Academy of Sciences Publication Activity Database

    Glogarová, Milada; Novotná, Vladimíra; Kašpar, Miroslav; Hamplová, Věra; Pociecha, D.

    2008-01-01

    Roč. 81, 11-12 (2008), 963-970 ISSN 0141-1594 R&D Projects: GA MŠk OC 175; GA AV ČR IAA100100710 Institutional research plan: CEZ:AV0Z10100520 Keywords : liquid crystals * paraelectric * ferroelectric and antiferroelectric phases * TGB phases * lactate unit Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.201, year: 2008

  14. Solid - solid and solid - liquid phase transitions of iron and iron alloys under laser shock compression

    Science.gov (United States)

    Harmand, M.; Krygier, A.; Appel, K.; Galtier, E.; Hartley, N.; Konopkova, Z.; Lee, H. J.; McBride, E. E.; Miyanishi, K.; Nagler, B.; Nemausat, R.; Vinci, T.; Zhu, D.; Ozaki, N.; Fiquet, G.

    2017-12-01

    An accurate knowledge of the properties of iron and iron alloys at high pressures and temperatures is crucial for understanding and modelling planetary interiors. While Earth-size and Super-Earth Exoplanets are being discovered in increasingly large numbers, access to detailed information on liquid properties, melting curves and even solid phases of iron and iron at the pressures and temperatures of their interiors is still strongly limited. In this context, XFEL sources coupled with high-energy lasers afford unique opportunities to measure microscopic structural properties at far extreme conditions. Also the achievable time resolution allows the shock history and phase transition mechanisms to be followed during laser compression, improving our understanding of the high pressure and high strain experiments. Here we present recent studies devoted to investigate the solid-solid and solid-liquid transition in laser-shocked iron and iron alloys (Fe-Si, Fe-C and Fe-O alloys) using X-ray diffraction and X-ray diffuse scattering. Experiment were performed at the MEC end-station of the LCLS facility at SLAC (USA). Detection of the diffuse scattering allowed the identification of the first liquid peak position along the Hugoniot, up to 4 Mbar. The time resolution shows ultrafast (between several tens and several hundreds of picoseconds) solid-solid and solid-liquid phase transitions. Future developments at XFEL facilities will enable detailed studies of the solid and liquid structures of iron and iron alloys as well as out-of-Hugoniot studies.

  15. Correlations between phase behaviors and ionic conductivities of (ionic liquid + alcohol) systems

    International Nuclear Information System (INIS)

    Park, Nam Ku; Bae, Young Chan

    2010-01-01

    To understand the basic properties of ionic liquids (ILs), we examined the phase behavior and ionic conductivity characteristics using various compositions of different ionic liquids (1-ethyl-3-methylimidazolium hexafluorophosphate [emim] [PF6] and 1-benzyl-3-methylimidazolium hexafluorophosphate [bzmim] [PF6]) in several different alcohols (ethanol, propanol, 1-butanol, 2-butanol, and hexanol). We conducted a systematic study of the impact of different factors on the phase behavior of imidazolium-based ionic liquids in alcohols. Using a new experimental method with a liquid electrolyte system, we observed that the ionic conductivity of the ionic liquid/alcohol was sensitive to the surrounding temperature. We employed Chang et al.'s thermodynamic model [Chang et al. (1997, 1998) ] based on the lattice model. The obtained co-ordinated unit parameter from this model was used to describe the phase behavior and ionic conductivities of the given system. Good agreement with experimental data of various alcohol and ILs systems was obtained in the range of interest.

  16. Fluctuations in an Inorganic Glass Forming System Capable of Liquid-Liquid Phase Separation

    Science.gov (United States)

    Bogdanov, V.; Maksimov, L.; Anan'ev, A.; Nemilov, S.; Rusan, V.

    2012-08-01

    Rayleigh and Mandel'shtam-Brillouin scattering (RMBS) spectroscopy and high temperature ultrasonic study (HTUS) are applied to PbO-Al2O3-B2O3 glass forming system characterized by over liquidus miscibility gap. Temperature dependences of ultrasonic velocity of glass melts were measured in 600-1200°C range. "Frozen-in" density fluctuations in two phase glasses were estimated from HTUS data by Macedo-Shroeder formulation. Landau-Placzek ratios were found from RMBS spectra of single phase glasses at room temperature. Results of RMBS and HTUS were compared with well-known SAXS data. It was found that contribution of "frozen-in" density fluctuations into light scattering by two-phase glasses is much smaller than the scattering on particles of the second glassy phase causing opalescence of the glasses. Abnormal "water-like" growth of ultrasonic velocity with melt temperature can be explained by coexistence of two types of packaging of structural elements.

  17. Geometric phase for N-level systems through unitary integration

    International Nuclear Information System (INIS)

    Uskov, D. B.; Rau, A. R. P.

    2006-01-01

    Geometric phases are important in quantum physics and are now central to fault-tolerant quantum computation. For spin 1/2, the Bloch sphere S 2 , together with a U(1) phase, provides a complete SU(2) description. We generalize to N-level systems and SU(N) in terms of a 2(N-1)-dimensional base space and reduction to a (N-1)-level problem, paralleling closely the two-dimensional case. This iteratively solves the time evolution of an N-level system and gives (N-1) geometric phases explicitly. A complete analytical construction of an S 4 Bloch-like sphere for two qubits is given for the Spin(5) or SO(5) subgroup of SU(4)

  18. Phase equilibria of didecyldimethylammonium nitrate ionic liquid with water and organic solvents

    International Nuclear Information System (INIS)

    Domanska, Urszula; Lugowska, Katarzyna; Pernak, Juliusz

    2007-01-01

    The phase diagrams for binary mixtures of an ammonium ionic liquid, didecyldimethylammonium nitrate, [DDA][NO 3 ], with: alcohols (propan-1-ol, butan-1-ol, octan-1-ol, and decan-1-ol): hydrocarbons (toluene, propylbenzene, hexane, and hexadecane) and with water were determined in our laboratory. The phase equilibria were measured by a dynamic method from T 220 K to either the melting point of the ionic liquid, or to the boiling point of the solvent. A simple liquidus curve in a eutectic system was observed for [DDA][NO 3 ] with: alcohols (propan-1-ol, butan-1-ol, and octan-1-ol); aromatic hydrocarbons (toluene and propylbenzene) and with water. (Solid + liquid) equilibria with immiscibility in the liquid phase were detected with the aliphatic hydrocarbons heptane and hexadecane and with decan-1-ol. (Liquid + liquid) equilibria for the system [DDA][NO 3 ] with hexadecane was observed for the whole mole fraction range of the ionic liquid. The observation of the upper critical solution temperature in binary mixtures of ([DDA][NO 3 ] + decan-1-ol, heptane, or hexadecane) was limited by the boiling temperature of the solvent. Characterisation and purity of the compounds were determined by elemental analysis, water content (Fisher method) and differential scanning microcalorimetry (d.s.c.) analysis. The d.s.c. method of analysis was used to determine melting temperatures and enthalpies of fusion. The thermal stability of the ionic liquid was resolved by the thermogravimetric technique-differential thermal analysis (TG-DTA) technique over a wide temperature range from (200 to 780) K. The thermal decomposition temperature of 50% of the sample was greater than 500 K. The (solid + liquid) phase equilibria, curves were correlated by means of different G Ex models utilizing parameters derived from the (solid + liquid) equilibrium. The root-mean-square deviations of the solubility temperatures for all calculated data are dependent upon the particular system and the particular

  19. Solid-Phase Extraction Combined with High Performance Liquid ...

    African Journals Online (AJOL)

    mean recovery of estrogen from milk samples varied from 92.6 to 104.1 %. Satisfactory ... growth, which causes a serious problem of estrogen being ... high circulating and urinary estrogen levels, as well as in ... methanol and stored at 4 oC in darkness. Then, ..... inflammatory drugs and estrogens in water by HPLC with UV ...

  20. Experimental investigation on two-phase thermosyphon loop with partially liquid-filled downcomer

    International Nuclear Information System (INIS)

    Zhang, Penglei; Wang, Baolong; Shi, Wenxing; Li, Xianting

    2015-01-01

    Highlights: • A visual thermosyphon loop test bench is established. • Partially liquid-filled phenomenon in the downcomer is discovered. • The driving force may be smaller than the conventional prediction. • Liquid head in the downcomer is self-regulated by influencing factors. • Larger height difference does not always lead to better performance. - Abstract: Two-phase thermosyphon loops (TPTLs) are beginning to be extensively used in the field of air conditioning and heat recovery, where they have quite different flow characteristics compared with the traditional TPTLs used in cooling of electronics. However, in the existing studies, the flow features in the downcomer were ignored, and most researchers simply thought the downcomer was always full of liquid. In this study, a visual experimental setup was established, the flow features in the downcomer were observed and measured. And the influencing factors including temperature difference, liquid charge, height difference, and circulation flow resistance on the liquid head have been identified and investigated experimentally. The results show that, different from the conventional understandings, the downcomer can be partially liquid filled. At this time, the upper part of downcomer is a static saturation gas blockage, surrounded by a layer of liquid film, which does not provide the driving force. The liquid head in the downcomer, which provides the driving force, shows great self-regulation ability with different working conditions. Increasing the refrigerant charge, temperature difference, circulation flow resistance, and decreasing the height difference drives the liquid head to rise, and the downcomer tends to be fully liquid filled.

  1. Performance of Liquid Phase Exfoliated Graphene As Electrochemical Double Layer Capacitors Electrodes

    Science.gov (United States)

    Huffstutler, Jacob; Wasala, Milinda; Richie, Julianna; Winchester, Andrew; Ghosh, Sujoy; Kar, Swastik; Talapatra, Saikat

    2014-03-01

    We will present the results of our investigations of electrochemical double layer capacitors (EDLCs) or supercapacitors (SC) fabricated using liquid-phase exfoliated graphene. Several electrolytes, such as aqueous potassium hydroxide KOH (6M), ionic 1-Butyl-3-methylimidazolium hexafluorophosphate [BMIM][PF6], and ionic 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl)trifluorophosphate[BMP][FAP] were used. These EDLC's show good performance compared to other carbon nanomaterials based EDLC's devices. We found that the liquid phase exfoliated graphene based devices possess specific capacitance values as high as 262 F/g, when used with ionic liquid electrolyte[BMP][FAP], with power densities (~ 454 W/kg) and energy densities (~ 0.38Wh/kg). Further, these devices indicated rapid charge transfer response even without the use of any binders or specially prepared current collectors. A detailed electrochemical impedance spectroscopy analysis in order to understand the phenomenon of charge storage in these materials will be presented.

  2. Well-posed Euler model of shock-induced two-phase flow in bubbly liquid

    Science.gov (United States)

    Tukhvatullina, R. R.; Frolov, S. M.

    2018-03-01

    A well-posed mathematical model of non-isothermal two-phase two-velocity flow of bubbly liquid is proposed. The model is based on the two-phase Euler equations with the introduction of an additional pressure at the gas bubble surface, which ensures the well-posedness of the Cauchy problem for a system of governing equations with homogeneous initial conditions, and the Rayleigh-Plesset equation for radial pulsations of gas bubbles. The applicability conditions of the model are formulated. The model is validated by comparing one-dimensional calculations of shock wave propagation in liquids with gas bubbles with a gas volume fraction of 0.005-0.3 with experimental data. The model is shown to provide satisfactory results for the shock propagation velocity, pressure profiles, and the shock-induced motion of the bubbly liquid column.

  3. Phase change predictions for liquid fuel in contact with steel structure using the heat conduction equation

    Energy Technology Data Exchange (ETDEWEB)

    Brear, D.J. [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center

    1998-01-01

    When liquid fuel makes contact with steel structure the liquid can freeze as a crust and the structure can melt at the surface. The melting and freezing processes that occur can influence the mode of fuel freezing and hence fuel relocation. Furthermore the temperature gradients established in the fuel and steel phases determine the rate at which heat is transferred from fuel to steel. In this memo the 1-D transient heat conduction equations are applied to the case of initially liquid UO{sub 2} brought into contact with solid steel using up-to-date materials properties. The solutions predict criteria for fuel crust formation and steel melting and provide a simple algorithm to determine the interface temperature when one or both of the materials is undergoing phase change. The predicted steel melting criterion is compared with available experimental results. (author)

  4. Phase separation temperatures of a liquid mixture: Dynamic light scattering technique

    International Nuclear Information System (INIS)

    Dangudom, K.; Wongtawatnugool, C.; Lacharojana, S.

    2010-01-01

    Light scattering intensity measurements and photon correlation spectroscopy (PCS) techniques were employed in an investigation of liquid-liquid phase separation behaviour of a mixture of cyclohexane and methanol at seven different compositions. It was found that, except for one composition (29% methanol), the temperature at which the scattering intensity was a maximum did not coincide with the one where the diffusion coefficient was a minimum, as would be for the case of a vapour-liquid system. The difference may be explained in terms of the local density fluctuation and the random walk problem responsible for the peak intensity and the minimum in the diffusion coefficient, respectively. The definition of phase separation temperature, as determined from diffusion process, was also proposed in this work.

  5. Phase change predictions for liquid fuel in contact with steel structure using the heat conduction equation

    International Nuclear Information System (INIS)

    Brear, D.J.

    1998-01-01

    When liquid fuel makes contact with steel structure the liquid can freeze as a crust and the structure can melt at the surface. The melting and freezing processes that occur can influence the mode of fuel freezing and hence fuel relocation. Furthermore the temperature gradients established in the fuel and steel phases determine the rate at which heat is transferred from fuel to steel. In this memo the 1-D transient heat conduction equations are applied to the case of initially liquid UO 2 brought into contact with solid steel using up-to-date materials properties. The solutions predict criteria for fuel crust formation and steel melting and provide a simple algorithm to determine the interface temperature when one or both of the materials is undergoing phase change. The predicted steel melting criterion is compared with available experimental results. (author)

  6. Do medium heavy fragments give evidence for a liquid-gas phase transition

    International Nuclear Information System (INIS)

    Trockel, R.; Hildenbrand, K.D.; Lynen, U.; Mueller, W.F.J.; Rabe, H.J.; Sann, H.; Stelzer, H.; Wada, R.; Brummund, N.; Glasow, R.; Kampert, K.H.; Santo, R.; Pelte, D.; Pochodzalla, J.; Eckert, E.

    1985-09-01

    Light and medium heavy fragments have been measured in light ion induced reactions at intermediate energies. The energy spectra have been parametrized with moving source fits. The resulting temperatures and yields do not confirm the expectations of a liquid-gas phase transition. (orig.)

  7. Dynamic simulation of dispersed gas-liquid two-phase flow using a discrete bubble model.

    NARCIS (Netherlands)

    Delnoij, E.; Lammers, F.A.; Kuipers, J.A.M.; van Swaaij, Willibrordus Petrus Maria

    1997-01-01

    In this paper a detailed hydrodynamic model for gas-liquid two-phase flow will be presented. The model is based on a mixed Eulerian-Lagrangian approach and describes the time-dependent two-dimensional motion of small, spherical gas bubbles in a bubble column operating in the homogeneous regime. The

  8. Highly Selective Liquid-Phase Benzylation of Anisole with Solid-Acid Zeolite Catalysts

    DEFF Research Database (Denmark)

    Poreddy, Raju; Shunmugavel, Saravanamurugan; Riisager, Anders

    2015-01-01

    Zeolites were evaluated as solid acid catalysts for the liquid-phase benzylation of anisole with benzyl alcohol, benzyl bromide, and benzyl chloride at 80 °C. Among the examined zeolites, H-mordenite-10 (H-MOR-10) demonstrated particular high activity (>99 %) and excellent selectivity (>96...

  9. Optimized random phase approximation for the structure of liquid alkali metals as electron-ion plasmas

    International Nuclear Information System (INIS)

    Senatore, G.; Tosi, M.P.; Trieste Univ.

    1981-08-01

    The purpose of this letter is to stress that the way towards an unconventional optimized-random-phase-approximation (ORPA) approach to the structure of liquid metals is indicated, and in fact already a good first-order solution for such an approach is provided

  10. Supported liquid phase catalyst coating in micro flow Mizoroki-Heck reaction

    NARCIS (Netherlands)

    Stouten, S.C.; Noël, T.; Wang, Q.; Hessel, V.

    2015-01-01

    A Supported Liquid Phase Catalyst (SLPC) coating was successfully applied for the Mizoroki–Heck reaction in micro flow. Foremost, extended on stream operation was enabled and the on stream performance stability was verified. Stable catalytic activity was achieved during two consecutive runs totaling

  11. Improved thermal lattice Boltzmann model for simulation of liquid-vapor phase change

    Science.gov (United States)

    Li, Qing; Zhou, P.; Yan, H. J.

    2017-12-01

    In this paper, an improved thermal lattice Boltzmann (LB) model is proposed for simulating liquid-vapor phase change, which is aimed at improving an existing thermal LB model for liquid-vapor phase change [S. Gong and P. Cheng, Int. J. Heat Mass Transfer 55, 4923 (2012), 10.1016/j.ijheatmasstransfer.2012.04.037]. First, we emphasize that the replacement of ∇ .(λ ∇ T ) /∇.(λ ∇ T ) ρ cV ρ cV with ∇ .(χ ∇ T ) is an inappropriate treatment for diffuse interface modeling of liquid-vapor phase change. Furthermore, the error terms ∂t 0(T v ) +∇ .(T vv ) , which exist in the macroscopic temperature equation recovered from the previous model, are eliminated in the present model through a way that is consistent with the philosophy of the LB method. Moreover, the discrete effect of the source term is also eliminated in the present model. Numerical simulations are performed for droplet evaporation and bubble nucleation to validate the capability of the model for simulating liquid-vapor phase change. It is shown that the numerical results of the improved model agree well with those of a finite-difference scheme. Meanwhile, it is found that the replacement of ∇ .(λ ∇ T ) /∇ .(λ ∇ T ) ρ cV ρ cV with ∇ .(χ ∇ T ) leads to significant numerical errors and the error terms in the recovered macroscopic temperature equation also result in considerable errors.

  12. The cone phase of liquid crystals: Triangular lattice of double-tilt ...

    Indian Academy of Sciences (India)

    (figure 3) and analyse the mechanism which stabilizes it. Liquid crystals are soft ... There is no change in the smectic layer spacing along .... with the case of blue phases of cubic symmetry where the pitch of the helix provides a natural length ...

  13. Strength and reliability of low temperature transient liquid phase bonded Cu-Sn-Cu interconnects

    DEFF Research Database (Denmark)

    Brincker, Mads; Söhl, Stefan; Eisele, Ronald

    2017-01-01

    As power electronic devices have tendencies to operate at higher temperatures and current densities, the demand for reliable and efficient packaging technologies are ever increasing. This paper reports the studies on application of transient liquid phase (TLP) bonding of CuSnCu systems...

  14. Density, viscosity and surface tension of liquid phase Beckmann rearrangement mixtures

    NARCIS (Netherlands)

    Zuidhof, K.T.; Croon, de M.H.J.M.; Schouten, J.C.; Tinge, J.T.

    2015-01-01

    We have determined the density, dynamic viscosity, and surface tension of liquid phase Beckmann rearrangement mixtures, consisting of e-caprolactam and fuming oleum. These important properties have been measured in wide ranges of both temperature and molar ratios of acid and e-caprolactam, covering

  15. Liquid-phase reforming and hydrodeoxygenation as a two-step route to aromatics from lignin

    NARCIS (Netherlands)

    Jongerius, A.L.; Bruijnincx, P.C.A.; Weckhuysen, B.M.

    2013-01-01

    A two-step approach to the conversion of organosolv, kraft and sugarcane bagasse lignin to monoaromatic compounds of low oxygen content is presented. The first step consists of lignin depolymerization in a liquid phase reforming (LPR) reaction over a 1 wt% Pt/γ-Al2O3 catalyst at 225 °C in alkaline

  16. Unusual vortex dynamics in the quantum-liquid phase of a-MoxSi1 ...

    Indian Academy of Sciences (India)

    liquid (QVL) phase has been well-determined in the field–temperature plane, δV (t) origi- ... [19], the field-driven SI transition corresponds to the VG transition from the VG to ... DC current I were measured using a four-terminal method. ..... tions is determined by T/Tc0, for these 'high-Tc' materials the quantum fluctuation.

  17. Assay of free urinary cortisol with inverted phase liquid chromatography and radiocompetition

    International Nuclear Information System (INIS)

    Franck, C.; Patricot, M.C.; Mathian, B.; Revol, A.

    1984-01-01

    The authors present an assay method for free urinary cortisol using inverted phase liquid chromatography for purification and radiocompetition for the assay. The usual values for adult men and women were established. The results of 150 routine assays were compared with those of 17 OHCS revealing the value of this assay [fr

  18. Synthesis of nanocrystalline TiO 2 thin films by liquid phase ...

    Indian Academy of Sciences (India)

    A transparent, high purity titanium dioxide thin film composed of densely packed nanometer sized grains has been successfully deposited on a glass substrate at 30°C from an aqueous solution of TiO2–HF with the addition of boric acid as a scavenger by liquid phase deposition technique. From X-ray diffraction ...

  19. Liquid phase stabilization versus bubble formation at a nanoscale curved interface

    Science.gov (United States)

    Schiffbauer, Jarrod; Luo, Tengfei

    2018-03-01

    We investigate the nature of vapor bubble formation near a nanoscale-curved convex liquid-solid interface using two models: an equilibrium Gibbs model for homogenous nucleation, and a nonequilibrium dynamic van der Waals-diffuse-interface model for phase change in an initially cool liquid. Vapor bubble formation is shown to occur for sufficiently large radius of curvature and is suppressed for smaller radii. Solid-fluid interactions are accounted for and it is shown that liquid-vapor interfacial energy, and hence Laplace pressure, has limited influence over bubble formation. The dominant factor is the energetic cost of creating the solid-vapor interface from the existing solid-liquid interface, as demonstrated via both equilibrium and nonequilibrium arguments.

  20. Supported Ionic Liquid Phase (SILP) Catalysis for the Production of Acetic acid by Methanol Carbonylation

    DEFF Research Database (Denmark)

    Hanning, Christopher William

    at the beginning with the construction of a suitable test reactor, then followed by the synthesis and testing of all the catalysts reported. A variety of nitrogen based ionic liquids were initially tested, giving good results and stability in the system. Later a number of phosphonium based salts were tested (these......The work presented here is focused on the development of a new reaction process. It applies Supported Ionic Liquid Phase (SILP) catalysis to a specific reaction. By reacting methanol and carbon monoxide over a rhodium catalyst, acetic acid can be formed. This reaction is important on a large scale...... were no longer classified as ionic liquids due to melting points above 100◦C). The phosphonium salts showed even better activity in the system compared to the ionic liquids. Overall the work has shown that this process for the manufacture of acetic acid is viable industrially. This is backed up...

  1. Gold catalyzed nickel disilicide formation: a new solid-liquid-solid phase growth mechanism.

    Science.gov (United States)

    Tang, Wei; Picraux, S Tom; Huang, Jian Yu; Liu, Xiaohua; Tu, K N; Dayeh, Shadi A

    2013-01-01

    The vapor-liquid-solid (VLS) mechanism is the predominate growth mechanism for semiconductor nanowires (NWs). We report here a new solid-liquid-solid (SLS) growth mechanism of a silicide phase in Si NWs using in situ transmission electron microcopy (TEM). The new SLS mechanism is analogous to the VLS one in relying on a liquid-mediating growth seed, but it is fundamentally different in terms of nucleation and mass transport. In SLS growth of Ni disilicide, the Ni atoms are supplied from remote Ni particles by interstitial diffusion through a Si NW to the pre-existing Au-Si liquid alloy drop at the tip of the NW. Upon supersaturation of both Ni and Si in Au, an octahedral nucleus of Ni disilicide (NiSi2) forms at the center of the Au liquid alloy, which thereafter sweeps through the Si NW and transforms Si into NiSi2. The dissolution of Si by the Au alloy liquid mediating layer proceeds with contact angle oscillation at the triple point where Si, oxide of Si, and the Au alloy meet, whereas NiSi2 is grown from the liquid mediating layer in an atomic stepwise manner. By using in situ quenching experiments, we are able to measure the solubility of Ni and Si in the Au-Ni-Si ternary alloy. The Au-catalyzed mechanism can lower the formation temperature of NiSi2 by 100 °C compared with an all solid state reaction.

  2. Design, Development and Testing of a Semi Cylindrical Capacitive Sensor for Liquid Level Measurement

    Directory of Open Access Journals (Sweden)

    Sagarika PAL

    2010-05-01

    Full Text Available In the present paper a low cost noncontact semi cylindrical capacitive type liquid level sensor has been designed, developed and tested. The semi cylindrical capacitive sensor consisting of two thin semi cylindrical metal plates separated by a gap distance and mounted around a non conducting storage tank, has been used to measure the liquid level in the tank. The measured capacitance variation with variation of liquid level is linear and obtained in the nano farad range which again has been converted into voltage variation by using proper signal conditioning circuit. Since the sensor is noncontact type it can be used for both conducting and non conducting type of liquid contained within a non conducting tank. For converting the capacitance variation in to voltage variation a series R-L-C resonating circuit has been used instead of conventional bridge circuit. Experimental results confirm the satisfactory performance of the sensor for liquid level measurement.

  3. Extraterrestrial material analysis: loss of amino acids during liquid-phase acid hydrolysis

    Science.gov (United States)

    Buch, Arnaud; Brault, Amaury; Szopa, Cyril; Freissinet, Caroline

    2015-04-01

    Searching for building blocks of life in extraterrestrial material is a way to learn more about how life could have appeared on Earth. With this aim, liquid-phase acid hydrolysis has been used, since at least 1970 , in order to extract amino acids and other organic molecules from extraterrestrial materials (e.g. meteorites, lunar fines) or Earth analogues (e.g. Atacama desert soil). This procedure involves drastic conditions such as heating samples in 6N HCl for 24 h, either under inert atmosphere/vacuum, or air. Analysis of the hydrolyzed part of the sample should give its total (free plus bound) amino acid content. The present work deals with the influence of the 6N HCl hydrolysis on amino acid degradation. Our experiments have been performed on a standard solution of 17 amino acids. After liquid-phase acid hydrolysis (6N HCl) under argon atmosphere (24 h at 100°C), the liquid phase was evaporated and the dry residue was derivatized with N-Methyl-N-(t-butyldimethylsilyl)trifluoroacetamide (MTBSTFA) and dimethylformamide (DMF), followed by gas chromatography-mass spectrometry analysis. After comparison with derivatized amino acids from the standard solution, a significant reduction of the chromatographic peak areas was observed for most of the amino acids after liquid-phase acid hydrolysis. Furthermore, the same loss pattern was observed when the amino acids were exposed to cold 6N HCl for a short amount of time. The least affected amino acid, i.e. glycine, was found to be 73,93% percent less abundant compared to the non-hydrolyzed standard, while the most affected, i.e. histidine, was not found in the chromatograms after hydrolysis. Our experiments thereby indicate that liquid-phase acid hydrolysis, even under inert atmosphere, leads to a partial or total loss of all of the 17 amino acids present in the standard solution, and that a quick cold contact with 6N HCl is sufficient to lead to a loss of amino acids. Therefore, in the literature, the reported increase

  4. Group theoretical arguments on the Landau theory of second-order phase transitions applied to the phase transitions in some liquid crystals

    International Nuclear Information System (INIS)

    Rosciszewski, K.

    1979-01-01

    The phase transitions between liquids and several of the simplest liquid crystalline phases (nematic, cholesteric, and the simplest types of smectic A and smectic C) were studied from the point of view of the group-theoretical arguments of Landau theory. It was shown that the only possible candidates for second-order phase transitions are those between nematic and smectic A, between centrosymmetric nematic and smectic C and between centrosymmetric smectic A and smectic C. Simple types of density functions for liquid crystalline phases are proposed. (author)

  5. Liquid phase surface nitriding of Ti-6Al-4V pre-placed with chromium

    Energy Technology Data Exchange (ETDEWEB)

    Vahedi Nemani, Alireza, E-mail: alireza_vahedi@ut.ac.ir; Sohi, M. Heydarzadeh; Amadeh, A.A.; Ghaffari, Mahya

    2016-08-01

    In this study, liquid phase surface nitriding of Ti-6Al-4V was carried out by pre-placing of chromium powder on the substrate and subsequent Tungsten Inert Gas (TIG) surface melting. The effect of the application of low and high heat inputs on the microstructure, microhardness and wear resistance of the treated layers were studied. Surface alloying with chromium in a nitrogen containing atmosphere resulted in the formation of hard intermetallic compounds such as TiN, Cr{sub 2}N and TiCr{sub 2}. Moreover, the presence of beta stabilizer chromium together with the application of high heat input during surface treatment resulted in the presence of beta phase at room temperature. However, applying low heat input could not prevent transformation of beta to martensite. The hardness of the layers fabricated at high and low heat inputs were respectively 1050 and 1200 HV{sub 0.3} compared to average 280 HV{sub 0.3} for the as-received material. Liquid phase surface treatment of titanium at the aforementioned conditions improved the wear resistance. The lowest weight loss belonged to the specimen with the beta phase matrix. The formation of the fairly ductile bcc-β phase hindered crack nucleation during wear. The weight loss in this condition was 7 times lower than that of the base material. - Highlights: • Liquid phase surface nitriding of Ti-6Al-4V was carried out by TIG surface melting. • Cr powder was pre-placed on the surface as the beta stabilizer alloying element. • The treated layers were characterized by OM, SEM and X-ray diffraction pattern. • Hardness of the layers increased up to 3 times higher than that of the base alloy. • Liquid phase surface alloying improved the wear resistance.

  6. Structure of the gas-liquid annular two-phase flow in a nozzle section

    International Nuclear Information System (INIS)

    Yoshida, Kenji; Kataoka, Isao; Ohmori, Syuichi; Mori, Michitsugu

    2006-01-01

    Experimental studies on the flow behavior of gas-liquid annular two-phase flow passing through a nozzle section were carried out. This study is concerned with the central steam jet injector for a next generation nuclear reactor. In the central steam jet injector, steam/water annular two-phase flow is formed at the mixing nozzle. To make an appropriate design and to establish the high-performance steam injector system, it is very important to accumulate the fundamental data of the thermo-hydro dynamic characteristics of annular flow passing through a nozzle section. On the other hand, the transient behavior of multiphase flow, in which the interactions between two-phases occur, is one of the most interesting scientific issues and has attracted research attention. In this study, the transient gas-phase turbulence modification in annular flow due to the gas-liquid phase interaction is experimentally investigated. The annular flow passing through a throat section is under the transient state due to the changing cross sectional area of the channel and resultantly the superficial velocities of both phases are changed compared with a fully developed flow in a straight pipe. The measurements for the gas-phase turbulence were precisely performed by using a constant temperature hot-wire anemometer, and made clear the turbulence structure such as velocity profiles, fluctuation velocity profiles. The behavior of the interfacial waves in the liquid film flow such as the ripple or disturbance waves was also observed. The measurements for the liquid film thickness by the electrode needle method were also performed to measure the base film thickness, mean film thickness, maximum film thickness and wave height of the ripple or the disturbance waves. (author)

  7. The impact of liquid-liquid-vapour phase behaviour on coke formation from model coke precusors

    Energy Technology Data Exchange (ETDEWEB)

    Minicucci, D.; Shaw, J.M. [Univ. of Toronto, Dept. of Chemical Engineering and Applied Chemistry, Toronto, ON (Canada)

    2000-08-01

    Catalysts used in the hydroprocessing of heavy feedstocks deactivate due to coke deposition. Although the mechanism for coke formation is not fully understood, condensation reactions of polynuclear aromatic compounds present in the feeds are a key aspect. The effect of coke deposition on catalyst performance is typically modelled using accelerated aging agents comprising model coke precursors. Mixtures employed in such studies polynuclear aromatic compounds such as anthracene as the coke precursor, and long chain alkanes such as hexadecane as a diluent. We show in this paper that binary and pseudo binary mixtures of polynuclear aromatic compounds and n-alkanes present TYPE II, TYPE IV, or TYPE III phase behaviour according to the van Konynenburg and Scott (1980) phase projection nomenclature, Incubation periods and the apparent autocatalytic effects associated with coke deposition in such systems are explained through a combination of high temperature phase equilibrium experiments and computations with the model systems n-alkane + anthracene + hydrogen, n-alkane + pyrene + hydrogen, and n-alkane + dibenzo[a,k]chrysene + hydrogen. (au)

  8. Vortex-Induced Waves in Two-Phase Liquid-Liquid Flows past Bluff Body

    Science.gov (United States)

    Zainal Abidin, M. I. I.; Park, Kyeong H.; Angeli, Panagiota; Xie, Zhihua; Kahouadji, Lyes; Matar, Omar K.

    2017-11-01

    Transverse cylinders of various sizes are used to generate vortex-induced interfacial waves in two-phase oil-water flows and to influence flow pattern transitions. The vortex shedding properties at different cylinder sizes and the resulting induced waves are studied experimentally with Particle Image Velocimetry (PIV) and high-speed imaging. The system consists of a 7 m long horizontal 37 mm ID acrylic pipe and different cylinders with diameters of 2, 5 and 8 mm, located in the water phase, 460 mm after the two phases come into contact. The cylinder generates waves with frequencies similar to the von Karman vortices and changes in vortex shedding properties at different cylinder size are reflected on the resulting interfacial wave characteristics. The presence of the transverse cylinder actuates the transition from stratified to dispersed flows; the boundary between the two patterns is shifted to lower mixture velocity with increasing cylinder size. Three-dimensional numerical simulation of the system is developed to assist in designing new system. Project funded by EPSRC UK and Memphis Grant.

  9. Calculation of liquid-liquid equilibrium of aqueous two-phase systems using a chemical-theory-based excess Gibbs energy model

    Directory of Open Access Journals (Sweden)

    Pessôa Filho P. A.

    2004-01-01

    Full Text Available Mixtures containing compounds that undergo hydrogen bonding show large deviations from ideal behavior. These deviations can be accounted for through chemical theory, according to which the formation of a hydrogen bond can be treated as a chemical reaction. This chemical equilibrium needs to be taken into account when applying stability criteria and carrying out phase equilibrium calculations. In this work, we illustrate the application of the stability criteria to establish the conditions under which a liquid-phase split may occur and the subsequent calculation of liquid-liquid equilibrium using a chemical-theory-modified Flory-Huggins equation to describe the non ideality of aqueous two-phase systems composed of poly(ethylene glycol and dextran. The model was found to be able to correlate ternary liquid-liquid diagrams reasonably well by simple adjustment of the polymer-polymer binary interaction parameter.

  10. Characterization and parametrical study of Rh-TPPTS supported ionic liquid phase (SILP) catalysts for ethylene hydroformylation

    DEFF Research Database (Denmark)

    Hanh, Nguyen Thi Ha; Duc, Duc Truong; Thang, Vu Dao

    2012-01-01

    The supported ionic liquid phase (SILP) catalysis technology was applied to continuous, gas-phase hydroformylation of ethylene. Rh-TPPTS SILP catalysts with relatively low ionic liquid loading were shown to be stable and highly activity for ethylene hydroformylation. However, the catalytic activity......, BET surface area and pore morphology of the catalysts depended on the content of ionic liquid. Hence, catalysts with high ionic liquid loading content showed deactivation at high reaction temperatures, possibly caused by redistribution of ionic liquid out of the pores under these conditions. (C) 2012...

  11. Return and Liquidity Relationships on Market and Accounting Levels in Brazil

    Directory of Open Access Journals (Sweden)

    Fernanda Finotti Cordeiro Perobelli

    2016-08-01

    Full Text Available ABSTRACT This article discusses profitability-liquidity relationships on accounting and market levels for 872 shares of publicly-traded Brazilian companies, observed between 1994 and 2013. On the market level, the assumption is that share liquidity is able to reduce some of the risks incurred by investors, making them more willing to pay a higher price for liquid shares, which would lower expected market returns. On the accounting level, the basic hypothesis argues that a firm's holding more liquid assets is related to a conservative investment policy, possibly reducing accounting returns for shareholders. Under the assumption of financial constraint, however, more accounting liquidity would allow positive net present value investments to be carried out, increasing future accounting returns, which would positively affect market liquidity and share prices in an efficient market, resulting in a lower market risk/expected return premium. Under the assumption of no financial constraint, however, more accounting liquidity would only represent a carry cost, compromising future accounting returns, which would adversely affect market liquidity and share prices and result in a higher market risk/expected return premium. Among the hypotheses, the presence of a negative market liquidity premium was verified in Brazil, with shares that traded more exhibiting a higher expected market return. On the margins of the major theories on the subject, only two negative relationships between excess accounting liquidity and market liquidity and accounting return, supporting the carry cost assumption for financially unconstrained firms, were verified. In terms of this paper's contributions, there is the analysis, unprecedented in Brazil as far as is known, of the relationship between liquidity and return on market and accounting levels, considering the financial constraint hypothesis to which the firms are subject.

  12. Competition, liquidity and stability: international evidence at the bank and systemic levels

    OpenAIRE

    Nguyen, Thi Ngoc My

    2017-01-01

    This thesis investigates the impact of market power on bank liquidity; the association between competition and systemic liquidity; and whether the associations between liquidity and stability at both bank- and systemic- levels are affected by competition. The first research question is explored in the context of 101 countries over 1996-2013 while the second and the third, which require listed banks, use a smaller sample of 32 nations during 2001-2013. The Panel Least Squares and the system Ge...

  13. Determination of antimony and tin in beverages using inductively coupled plasma-optical emission spectrometry after ultrasound-assisted ionic liquid dispersive liquid-liquid phase microextraction.

    Science.gov (United States)

    Biata, N Raphael; Nyaba, Luthando; Ramontja, James; Mketo, Nomvano; Nomngongo, Philiswa N

    2017-12-15

    The aim of this study was to develop a simple and fast ultrasound-assisted ionic liquid dispersive liquid-liquid phase microextraction (UA-IL-DLLME) method for preconcetration of trace antimony and tin in beverage samples. The novelty of this study was based on the application of ligandless UA-IL-DLLME using low-density ionic liquid and organic solvents for preconcentration of Sb and Sn. The concentration of Sb and Sn were quantified using ICP-OES. Under the optimum conditions, the calibration graph was found to be LOQ-250µgL -1 (r 2 =0.9987) for Sb and LOQ-350µgL -1 for Sn. The LOD and LOQ of Sb and Sn ranged from 1.2to 2.5ngL -1 and 4.0 to 8.3ngL -1 , respectively, with high preconcentration factors. The precisions (%RSD) of the proposed method ranged from 2.1% to 2.5% and 3.9% to 4.7% for Sb and Sn, respectively. The proposed method was successfully applied for determination of Sb and Sn in beverages. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Computation of liquid-liquid equilibria and phase stabilities: implications for RH-dependent gas/particle partitioning of organic-inorganic aerosols

    Directory of Open Access Journals (Sweden)

    A. Zuend

    2010-08-01

    Full Text Available Semivolatile organic and inorganic aerosol species partition between the gas and aerosol particle phases to maintain thermodynamic equilibrium. Liquid-liquid phase separation into an organic-rich and an aqueous electrolyte phase can occur in the aerosol as a result of the salting-out effect. Such liquid-liquid equilibria (LLE affect the gas/particle partitioning of the different semivolatile compounds and might significantly alter both particle mass and composition as compared to a one-phase particle. We present a new liquid-liquid equilibrium and gas/particle partitioning model, using as a basis the group-contribution model AIOMFAC (Zuend et al., 2008. This model allows the reliable computation of the liquid-liquid coexistence curve (binodal, corresponding tie-lines, the limit of stability/metastability (spinodal, and further thermodynamic properties of multicomponent systems. Calculations for ternary and multicomponent alcohol/polyol-water-salt mixtures suggest that LLE are a prevalent feature of organic-inorganic aerosol systems. A six-component polyol-water-ammonium sulphate system is used to simulate effects of relative humidity (RH and the presence of liquid-liquid phase separation on the gas/particle partitioning. RH, salt concentration, and hydrophilicity (water-solubility are identified as key features in defining the region of a miscibility gap and govern the extent to which compound partitioning is affected by changes in RH. The model predicts that liquid-liquid phase separation can lead to either an increase or decrease in total particulate mass, depending on the overall composition of a system and the particle water content, which is related to the hydrophilicity of the different organic and inorganic compounds. Neglecting non-ideality and liquid-liquid phase separations by assuming an ideal mixture leads to an overestimation of the total particulate mass by up to 30% for the composition and RH range considered in the six

  15. Actinides and fission products partitioning from high level liquid waste

    International Nuclear Information System (INIS)

    Yamaura, Mitiko

    1999-01-01

    The presence of small amount of mixed actinides and long-lived heat generators fission products as 137 Cs and 90 Sr are the major problems for safety handling and disposal of high level nuclear wastes. In this work, actinides and fission products partitioning process, as an alternative process for waste treatment is proposed. First of all, ammonium phosphotungstate (PWA), a selective inorganic exchanger for cesium separation was chosen and a new procedure for synthesizing PWA into the organic resin was developed. An strong anionic resin loaded with tungstate or phosphotungstate anion enables the precipitation of PWA directly in the resinous structure by adding the ammonium nitrate in acid medium (R-PWA). Parameters as W/P ratio, pH, reactants, temperature and aging were studied. The R-PWA obtained by using phosphotungstate solution prepared with W/P=9.6, 9 hours digestion time at 94-106 deg C and 4 to 5 months aging time showed the best capacity for cesium retention. On the other hand, Sr separation was performed by technique of extraction chromatography, using DH18C6 impregnated on XAD7 resin as stationary phase. Sr is selectively extracted from acid solution and >99% was recovered from loaded column using distilled water as eluent. Concerning to actinides separations, two extraction chromatographic columns were used. In the first one, TBP(XAD7) column, U and Pu were extracted and its separations were carried-out using HNO 3 and hydroxylamine nitrate + HNO 3 as eluent. In the second one, CMP0-TBP(XAD7) column, the actinides were retained on the column and the separations were done by using (NH 4 ) 2 C 2 O 4 , DTPA, HNO 3 and HCl as eluent. The behavior of some fission products were also verified in both columns. Based on the obtained data, actinides and fission products Cs and Sr partitioning process, using TBP(XAD7) and CMP0-TBP(XAD7) columns for actinides separation, R-PWA column for cesium retention and DH18C6(XAD7) column for Sr isolation was performed

  16. Selective determination of inorganic cobalt in nutritional supplements by ultrasound-assisted temperature-controlled ionic liquid dispersive liquid phase microextraction and electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Berton, Paula; Martinis, Estefanía M.; Martinez, Luis D.; Wuilloud, Rodolfo G.

    2012-01-01

    Highlights: ► Synergy of ultrasound energy and TILDLME technique for improved metal extraction. ► Highly selective determination of inorganic Co species at trace levels. ► Speciation analysis of Co in several nutritional supplements with highly complex matrices. ► Development of an environmentally friendly microextraction technique with minimal waste production and sample consumption. - Abstract: In the present work, a simple and rapid analytical method based on application of ionic liquids (ILs) for inorganic Co(II) species (iCo) microextraction in a variety of nutrient supplements was developed. Inorganic Co was initially chelated with 1-nitroso-2-naphtol (1N2N) reagent followed by a modern technique named ultrasound-assisted temperature-controlled ionic liquid dispersive liquid phase microextraction (USA-TILDLME). The extraction was performed with 1-hexyl-3-methylimidazolium hexafluorophosphate [C 6 mim][PF 6 ] with the aid of ultrasound to improve iCo recovery. Finally, the iCo-enriched IL phase was solubilized in methanol and directly injected into an electrothermal atomic absorption spectrometer (ETAAS). Several parameters that could influence iCo microextraction and detection were carefully studied. Since the main difficulty in these samples is caused by high concentrations of potential interfering ions, different approaches were evaluated to eliminate interferences. The limit of detection (LOD) was 5.4 ng L −1 , while the relative standard deviation (RSD) was 4.7% (at 0.5 μg L −1 Co level and n = 10), calculated from the peak height of absorbance signals. Selective microextraction of iCo species was achieved only by controlling the pH value during the procedure. The method was thus successfully applied for determination of iCo species in nutritional supplements.

  17. Selective determination of inorganic cobalt in nutritional supplements by ultrasound-assisted temperature-controlled ionic liquid dispersive liquid phase microextraction and electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Berton, Paula; Martinis, Estefania M. [Analytical Chemistry Research and Development Group (QUIANID), (LISAMEN-CCT-CONICET-Mendoza), Av. Ruiz Leal S/N Parque General San Martin, M 5502 IRA Mendoza (Argentina); Martinez, Luis D. [INQUISAL-CONICET, Departamento de Quimica Analitica, Facultad de Quimica, Bioquimica y Farmacia, Universidad Nacional de San Luis, San Luis (Argentina); Wuilloud, Rodolfo G., E-mail: rwuilloud@mendoza-conicet.gob.ar [Analytical Chemistry Research and Development Group (QUIANID), (LISAMEN-CCT-CONICET-Mendoza), Av. Ruiz Leal S/N Parque General San Martin, M 5502 IRA Mendoza (Argentina); Instituto de Ciencias Basicas, Universidad Nacional de Cuyo, Mendoza (Argentina)

    2012-02-03

    Highlights: Black-Right-Pointing-Pointer Synergy of ultrasound energy and TILDLME technique for improved metal extraction. Black-Right-Pointing-Pointer Highly selective determination of inorganic Co species at trace levels. Black-Right-Pointing-Pointer Speciation analysis of Co in several nutritional supplements with highly complex matrices. Black-Right-Pointing-Pointer Development of an environmentally friendly microextraction technique with minimal waste production and sample consumption. - Abstract: In the present work, a simple and rapid analytical method based on application of ionic liquids (ILs) for inorganic Co(II) species (iCo) microextraction in a variety of nutrient supplements was developed. Inorganic Co was initially chelated with 1-nitroso-2-naphtol (1N2N) reagent followed by a modern technique named ultrasound-assisted temperature-controlled ionic liquid dispersive liquid phase microextraction (USA-TILDLME). The extraction was performed with 1-hexyl-3-methylimidazolium hexafluorophosphate [C{sub 6}mim][PF{sub 6}] with the aid of ultrasound to improve iCo recovery. Finally, the iCo-enriched IL phase was solubilized in methanol and directly injected into an electrothermal atomic absorption spectrometer (ETAAS). Several parameters that could influence iCo microextraction and detection were carefully studied. Since the main difficulty in these samples is caused by high concentrations of potential interfering ions, different approaches were evaluated to eliminate interferences. The limit of detection (LOD) was 5.4 ng L{sup -1}, while the relative standard deviation (RSD) was 4.7% (at 0.5 {mu}g L{sup -1} Co level and n = 10), calculated from the peak height of absorbance signals. Selective microextraction of iCo species was achieved only by controlling the pH value during the procedure. The method was thus successfully applied for determination of iCo species in nutritional supplements.

  18. Phase diagram of nanoscale alloy particles used for vapor-liquid-solid growth of semiconductor nanowires.

    Science.gov (United States)

    Sutter, Eli; Sutter, Peter

    2008-02-01

    We use transmission electron microscopy observations to establish the parts of the phase diagram of nanometer sized Au-Ge alloy drops at the tips of Ge nanowires (NWs) that determine their temperature-dependent equilibrium composition and, hence, their exchange of semiconductor material with the NWs. We find that the phase diagram of the nanoscale drop deviates significantly from that of the bulk alloy, which explains discrepancies between actual growth results and predictions on the basis of the bulk-phase equilibria. Our findings provide the basis for tailoring vapor-liquid-solid growth to achieve complex one-dimensional materials geometries.

  19. Summary on experimental methods for statistical transient analysis of two-phase gas-liquid flow

    International Nuclear Information System (INIS)

    Delhaye, J.M.; Jones, O.C. Jr.

    1976-06-01

    Much work has been done in the study of two-phase gas-liquid flows. Although it has been recognized superficially that such flows are not homogeneous in general, little attention has been paid to the inherent discreteness of the two-phase systems. Only relatively recently have fluctuating characteristics of two-phase flows been studied in detail. As a result, new experimental devices and techniques have been developed for use in measuring quantities previously ignored. This report reviews and summarizes most of these methods in an effort to emphasize the importance of the fluctuating nature of these flows and as a guide to further research in this field

  20. Measurement of turbulent diffusivity of both gas and liquid phases in quasi-2D two-phase flow

    International Nuclear Information System (INIS)

    Sato, Yoshifusa; Sadatomi, Michio; Kawahara, Akimaro

    1993-01-01

    The turbulent diffusion process has been studied experimentally by observing a tracer plume emitted continuously from a line source in a uniform, quasi-2D two-phase flow. The test section was a vertical, relatively narrow, concentric annular channel consisting of two large pipes. Air and water were used as the working fluids, and methane and acid organge II were used as tracers for the respective phases. Measurements of local, time-averaged tracer concentrations were made by means of a sampling method and image processing for bubbly flows and churn flows, and the turbulent diffusivity, the coefficient of turbulent diffusion, was determined from the concentration distributions measured. The diffusivities for the gas and liquid phases, ε DG and ε DL respectively, are presented and compared with each other in this paper. When a flow is bubbly, ε DG is close to or slightly smaller than ε DL . In a churn flow, on the contrary, ε DG is much greater than ε DL . Regarding bubbly flow, a plausible model on turbulent diffusivity of the liquid phase is presented and examined by the present data. (orig.)

  1. Liquid-phase extraction coupled with metal-organic frameworks-based dispersive solid phase extraction of herbicides in peanuts.

    Science.gov (United States)

    Li, Na; Wang, Zhibing; Zhang, Liyuan; Nian, Li; Lei, Lei; Yang, Xiao; Zhang, Hanqi; Yu, Aimin

    2014-10-01

    Liquid-phase extraction coupled with metal-organic frameworks-based dispersive solid phase extraction was developed and applied to the extraction of pesticides in high fatty matrices. The herbicides were ultrasonically extracted from peanut using ethyl acetate as extraction solvent. The separation of the analytes from a large amount of co-extractive fat was achieved by dispersive solid-phase extraction using MIL-101(Cr) as sorbent. In this step, the analytes were adsorbed on MIL-101(Cr) and the fat remained in bulk. The herbicides were separated and determined by high-performance liquid chromatography. The experimental parameters, including type and volume of extraction solvent, ultrasonication time, volume of hexane and eluting solvent, amount of MIL-101(Cr) and dispersive solid phase extraction time, were optimized. The limits of detection for herbicides range from 0.98 to 1.9 μg/kg. The recoveries of the herbicides are in the range of 89.5-102.7% and relative standard deviations are equal or lower than 7.0%. The proposed method is simple, effective and suitable for treatment of the samples containing high content of fat. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Liquid phase sintering of carbides using a nickel-molybdenum alloy

    International Nuclear Information System (INIS)

    Barranco, J.M.; Warenchak, R.A.

    1987-01-01

    Liquid phase vacuum sintering was used to densify four carbide groups. These were titanium carbide, tungsten carbide, vanadium carbide, and zirconium carbide. The liquid phase consisted of nickel with additions of molybdenum of from 6.25 to 50.0 weight percent at doubling increments. The liquid phase or binder comprised 10, 20, and 40 percent by weight of the pressed powders. The specimens were tested using 3 point bending. Tungsten carbide showed the greatest improvement in bend rupture strength, flexural modulus, fracture energy and hardness using 20 percent binder with lesser amounts of molybdenum (6.25 or 12.5 wt %) added to nickel compared to pure nickel. A refinement in the carbide microstructure and/or a reduction in porosity was seen for both the titanium and tungsten carbides when the alloy binder was used compared to using the nickel alone. Curves depicting the above properties are shown for increasing amounts of molybdenum in nickel for each carbide examined. Loss of binder phase due to evaporation was experienced during heating in vacuum at sintering temperatures. In an effort to reduce porosity, identical specimens were HIP processed at 15 ksi and temperatures averaging 110 C below the sintering g temperature. The tungsten carbide and titanium carbide series containing 80 and 90 weight percent carbide phase respectively showed improvement properties after HIP while properties decreased for most other compositions

  3. Chlorination of some eliphatic organic compounds in liquid and gas phase

    International Nuclear Information System (INIS)

    Hassan, A.A.

    1990-01-01

    The photochlorination of different organic compounds and the relative slectivities of different positions have been investigated in both gaseous and liquid phases at different temperatures. The results have shown that the relative selectivity generally decreased with increasing temperature and in the gas phase has a higher value. Polar solvents increase the selectivity relative to the chlorination of pure liquid phases. The differences in activation energy between two positions were much higher in the gas phases chlorination, relative to that in the liquid phase. It was also found that the functional groups have great influence on the rate of chlorine free radical attack on different positions, for example the electron withdrawing groups decreasing the selectivity on the first position, but the electron donating groups increase the selectivity on the first position, but the electron donating groups increase the selectivity on the first position. Furthermore it was found that the polar solvents, which stabilize the resonance between oxygen and carbon atoms, increases the selectivity on that position. 23 tabs.; 16 figs.; 50 refs

  4. Study on Calculation of Liquid Level And Storage of Tanks for LNG-fueled Vessels

    Science.gov (United States)

    Li, Kun; Wang, Guoqing; Liu, Chang

    2018-01-01

    As the ongoing development of the application of LNG as a clean energy in waterborne transport industry, the fleet scale of LNG-fueled vessels enlarged and the safety operation has attracted more attention in the industry. Especially the accurate detection of liquid level of LNG tanks is regarded as an important issue to ensure a safe and stable operation of LNG-fueled ships and a key parameter to keep the proper functioning of marine fuel storage system, supply system and safety control system. At present, detection of LNG tank liquid level mainly adopts differential pressure detection method. Liquid level condition could be found from the liquid level reference tables. However in practice, since LNG-fueled vessels are generally not in a stationary state, liquid state within the LNG tanks will constantly change, the detection of storage of tanks only by reference to the tables will cause deviation to some extent. By analyzing the temperature under different pressure, the effects of temperature change on density and volume integration calculation, a method of calculating the liquid level and storage of LNG tanks is put forward making the calculation of liquid level and actual storage of LNG tanks more accurately and providing a more reliable basis for the calculation of energy consumption level and operation economy for LNG-fueled vessels.

  5. Maxwell's Law Based Models for Liquid and Gas Phase Diffusivities in Variably-Saturated Soil

    DEFF Research Database (Denmark)

    Mamamoto, Shoichiro; Møldrup, Per; Kawamoto, Ken

    2012-01-01

    -s,D-l). Different percolation threshold terms adopted from recent studies for gas (D-s,D-g) and solute (D-s,D-l) diffusion were applied. For gas diffusion, epsilon(th) was a function of bulk density (total porosity), while for solute diffusion theta(th) was best described by volumetric content of finer soil...... particles (clay and organic matter), FINESvol. The resulting LIquid and GAs diffusivity and tortuosity (LIGA) models were tested against D-s,D-g and D-s,D-l data for differently-textured soils and performed well against the measured data across soil types. A sensitivity analysis using the new Maxwell's Law...... based LIGA models implied that the liquid phase but not the gaseous-phase tortuosity was controlled by soil type. The analyses also suggested very different pathways and fluid-phase connectivity for gas and solute diffusion in unsaturated soil...

  6. 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.

  7. Metastable Phase Separation and Concomitant Solute Redistribution of Liquid Fe-Cu-Sn Ternary Alloy

    International Nuclear Information System (INIS)

    Xiao-Mei, Zhang; Wei-Li, Wang; Ying, Ruan; Bing-Bo, Wei

    2010-01-01

    Liquid Fe-Cu-Sn ternary alloys with lower Sn contents are usually assumed to display a peritectic-type solidification process under equilibrium condition. Here we show that liquid Fe 47.5 Cu 47.5 Sn 5 ternary alloy exhibits a metastable immiscibility gap in the undercooling range of 51–329 K (0.19T L ). Macroscopic phase separation occurs once undercooling exceeds 196 K and causes the formation of a floating Fe-rich zone and a descending Cu-rich zone. Solute redistribution induces the depletion of Sn concentration in the Fe-rich zone and its enrichment in the Cu-rich zone. The primary Fe phase grows dendritically and its growth velocity increases with undercooling until the appearance of notable macrosegregation, but will decrease if undercooling further increases beyond 236 K. The microsegregation degrees of both solutes in Fe and Cu phases vary only slightly with undercooling. (condensed matter: structure, mechanical and thermal properties)

  8. Simulations of electrolytes at the liquid-liquid interface and of lanthanide cations complexes in gas phase; Simulations d'electrolytes a l'interface liquide/liquide et de complexes de cations lanthanides en phase gazeuse

    Energy Technology Data Exchange (ETDEWEB)

    Berny, F

    2000-07-01

    Two processes related to liquid/liquid extraction of ions by extractant molecules were studied: the ion approach at the interface and the ion complexation by ligands. In the first part, the behaviour of salts at the chloroform/water interface was simulated by molecular dynamics. The aim was to understand the way these salts ions approach the interface in order to be extracted. Some ions are repelled by the interface (K{sup +}, Cl{sup -}, UO{sub 2}{sup 2+}, Na{sup +}, NO{sub 3}{sup -}) whereas others adsorb (amphiphilic molecules and also ClO{sub 4}{sup -}, SCN{sup -}, guanidinium Gu{sup +} and picrate Pic{sup -}). The surface-active counter-ions make the ion approach at the interface easier. In a perfectly homogeneous mixture of the two solvents (water and chloroform) de-mixing, the ions seem to influence the phases separation rate. Nitric acid which is known to favour liquid/liquid extraction reveals strong adsorption at the interface in its neutral form and a smaller one in its ionic form (H{sub 3}O{sup +}/NO{sub 3}{sup -}). HNO{sub 3} and H{sub 3}O{sup +} display particular orientations at the interface: hydrogen atoms are pointing in the direction of the water slab. The nature of the organic phase can also influence the ion approach at the interface. For example, Gu{sup +} and Pic{sup -} adsorb much less at the supercritical CO{sub 2}/water interface than at the chloroform/water interface. In the second part, complexes of La{sup 3+}, Eu{sup 3+} and Yb{sup 3+} with ligands such as amide, urea, thio-amide, thiourea were studied by quantum mechanics. Our calculations show that cation-ligand interactions depend on the nature of substituents on ligands, on the presence of counter-ions or on the number of ligands in the complex. Sulfur compounds seem to less interact with cations than oxygen compounds. Ureas interact as much as amides and are potentially good ligands. (author)

  9. experimental implementation of single-phase, three-level, sinusoidal

    African Journals Online (AJOL)

    Page 1 ... of many multilevel inverter configurations. This paper presents an experimental report of a simplified topology for single-phase, SPWM, three-level voltage source inverter wit R-L load. To keep the power circuit ... employed in many industrial applications such as variable speed drives, uninterruptible power sup-.

  10. Calculation of liquid-liquid phase separation in a ternary system of a polymer in a mixture of a solvent and a nonsolvent

    NARCIS (Netherlands)

    Altena, Frank W.; Smolders, C.A.

    1982-01-01

    A numerical method for the calculation of the binodal of liquid-liquid phase separation in a ternary system is described. The Flory-Huggins theory for three-component systems is used. Binodals are calculated for polymer/solvent/nonsolvent systems which are used in the preparation of asymmetric

  11. Comprehensive two-dimensional liquid chromatography: Ion chromatography × reversed-phase liquid chromatography for separation of low-molar-mass organic acids

    NARCIS (Netherlands)

    Brudin, S.S.; Shellie, R.A.; Haddad, P.R.; Schoenmakers, P.J.

    2010-01-01

    In the work presented here a novel approach to comprehensive two-dimensional liquid chromatography is evaluated. Ion chromatography is chosen for the first-dimension separation and reversed-phase liquid chromatography is chosen for the second-dimension separation mode. The coupling of these modes is

  12. Liquid Phase Behaviour in Systems of 1-Butyl-3-Alkylimidazolium bis(trifluoromethyl)SulfonylimideIonic Liquids with Water: Influence of the Structure of the C5 Alkyl Substituent.

    Czech Academy of Sciences Publication Activity Database

    Rotrekl, Jan; Storch, Jan; Velíšek, Petr; Schröer, W.; Jacquemin, J.; Wagner, Zdeněk; Husson, P.; Bendová, Magdalena

    2017-01-01

    Roč. 46, č. 7 (2017), s. 1456-1474 ISSN 0095-9782 R&D Projects: GA MŠk LD14090 Institutional support: RVO:67985858 Keywords : ionic liquids * liquid phase behaviour * ising model Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 1.342, year: 2016

  13. Radioimmuoassay study of antidigitoxin antibodies in liquid phase and after coupling on a solid phase

    International Nuclear Information System (INIS)

    Collignon, A.; German, A.; Scherrmann, J.M.; Bourdon, R.

    1983-01-01

    Antidigitoxin antibodies prepared by immunizing rabbits with a digitoxin-bovine serum albumin conjugate have been studied by radioimmunoassay in the native serum (homogeneous phase antibodies) and after coupling on glass beads (heterogeneous phase antibodies). Homogeneous phase antibodies present a satisfactory titer and affinity constant and react very specifically with digitoxin. Fixation of antibodies on a solid phase induce a loss of their immunoreactivity as it is showed by modification of the inhibition curves, by a greater sensitivity to the chemical structure of the tracer and by a decrease of the affinity constant. Reactionnal kinetic and sensitivity to the incubation temperature are not modified. Heterogeneous phase antibodies present a greater stability. Both antibodies types can be used for a digitoxin radioimmunoassay [fr

  14. Tobacco-Specific Nitrosamines in Electronic Cigarettes: Comparison between Liquid and Aerosol Levels

    Directory of Open Access Journals (Sweden)

    Konstantinos E. Farsalinos

    2015-07-01

    Full Text Available Introduction: Although electronic cigarette (EC liquids contain low levels of tobacco-specific nitrosamines (TSNAs, studies evaluating the levels emitted to the aerosol are scarce. The purpose of this study was to compare the levels of TSNAs between liquids and generated aerosol. Methods: Three EC liquids were obtained from the market. An additional (spiked sample was prepared by adding known amounts of standard TSNAs solutions to one of the obtained liquids. N-nitrosonornicotine (NNN, N-nitrosoanatabine (NAT, N-nitrosoanabasine (NAB and 4-(methylnitrosamino1-(3-pyridyl-1-butanone (NNK were measured. Three 100-puff sets from each liquid were trapped in filter pads and were subsequently analyzed for the presence of TSNAs. The expected levels of TSNAs (calculated based on the liquid consumption were compared with the measured levels in the aerosol. Results: Only NAB was found at trace levels in two commercial liquids (1.2 and 2.3 ng/g, while the third contained 1.5 ng/g NAB and 7.7 ng/g NNN. The 100-puff sets resulted in 336–515 mg liquid consumption, with no TSNAs being detected in the aerosol. The spiked sample contained 42.0–53.9 ng/g of each of the TSNAs. All TSNAs were detected in the aerosol with the measured levels being statistically similar to the expected amounts. A significant correlation between expected and measured levels of TSNAs in the aerosol was found (r = 0.83, p < 0.001. Conclusion: The findings of this study show that exposure of EC users to TSNAs can be accurately assessed based on the levels present in the liquid, without the need to analyze the aerosol.

  15. Molecular reorientations in a substance with liquid-crystalline and plastic-crystalline phases

    International Nuclear Information System (INIS)

    Nguyen, Xuan Phuc.

    1986-05-01

    Results of dielectric relaxation (DR), quasielastic neutron scattering (QNS), far infrared absorption (FIR), proton magnetic resonance (PMR), differential scanning calorimetry (DSC) and preliminary X-ray diffraction measurements on the di-n-pentyloxyazoxybenzene (5.OAOB) are presented. The measurements carried out by all these methods showed that 5.OAOB exhibits a nontypical for liquid-crystalline materials phase diagram. It has two mesophases: a nematic (N) and an ''intermediate'' crystalline phase just below it. A complex interpretation of results obtained is given. All suggestions concerning the character of reorientational motions of the molecule as a whole as well as of its segments in mesomorphic phases are analyzed. From comparison of the DR and QNS studies one can conclude that in the N phase the molecule as a whole performs rotational diffusion around the long axis (τ DR ∼ 100 ps) and at the same time the two moieties perform faster independent reorientations around N - benzene rings bonds withτ QNS ∼ 5 ps. On the basis of various experimental data it is shown that the CrI phase is a plastic-crystalline phase for which the molecule and its segments perform fast stochastic unaxial reorientations. This is the first case where the existence of such a phase in liquid-crystalline materials has been experimentally confirmed. (author)

  16. Applications of liquid-phase microextraction in the sample preparation of environmental solid samples.

    Science.gov (United States)

    Prosen, Helena

    2014-05-23

    Solvent extraction remains one of the fundamental sample preparation techniques in the analysis of environmental solid samples, but organic solvents are toxic and environmentally harmful, therefore one of the possible greening directions is its miniaturization. The present review covers the relevant research from the field of application of microextraction to the sample preparation of environmental solid samples (soil, sediments, sewage sludge, dust etc.) published in the last decade. Several innovative liquid-phase microextraction (LPME) techniques that have emerged recently have also been applied as an aid in sample preparation of these samples: single-drop microextraction (SDME), hollow fiber-liquid phase microextraction (HF-LPME), dispersive liquid-liquid microextraction (DLLME). Besides the common organic solvents, surfactants and ionic liquids are also used. However, these techniques have to be combined with another technique to release the analytes from the solid sample into an aqueous solution. In the present review, the published methods were categorized into three groups: LPME in combination with a conventional solvent extraction; LPME in combination with an environmentally friendly extraction; LPME without previous extraction. The applicability of these approaches to the sample preparation for the determination of pollutants in solid environmental samples is discussed, with emphasis on their strengths, weak points and environmental impact.

  17. Applications of Liquid-Phase Microextraction in the Sample Preparation of Environmental Solid Samples

    Directory of Open Access Journals (Sweden)

    Helena Prosen

    2014-05-01

    Full Text Available Solvent extraction remains one of the fundamental sample preparation techniques in the analysis of environmental solid samples, but organic solvents are toxic and environmentally harmful, therefore one of the possible greening directions is its miniaturization. The present review covers the relevant research from the field of application of microextraction to the sample preparation of environmental solid samples (soil, sediments, sewage sludge, dust etc. published in the last decade. Several innovative liquid-phase microextraction (LPME techniques that have emerged recently have also been applied as an aid in sample preparation of these samples: single-drop microextraction (SDME, hollow fiber-liquid phase microextraction (HF-LPME, dispersive liquid-liquid microextraction (DLLME. Besides the common organic solvents, surfactants and ionic liquids are also used. However, these techniques have to be combined with another technique to release the analytes from the solid sample into an aqueous solution. In the present review, the published methods were categorized into three groups: LPME in combination with a conventional solvent extraction; LPME in combination with an environmentally friendly extraction; LPME without previous extraction. The applicability of these approaches to the sample preparation for the determination of pollutants in solid environmental samples is discussed, with emphasis on their strengths, weak points and environmental impact.

  18. CARS detection of liquid-like phase appearance in small mesopores

    Science.gov (United States)

    Arakcheev, Vladimir G.; Bekin, Alexey N.; Morozov, Viacheslav B.

    2017-11-01

    Nonlinear-optical spectroscopic techniques that employ signals from the molecules located inside nanopores have promising potential for investigations of fluid behavior under nanoconfinement. Here, we apply coherent anti-Stokes spectroscopy to investigate the appearance of a liquid-like phase of carbon dioxide in mesoporous Vycor glass under isothermal compression. The spectra of the Q-branch (1388 cm-1) are registered at  -11 °C in a wide pressure range, starting from submonolayer coverage of the pore wall up to the bulk saturation pressure. Results show that a spectral contribution, similar to that of the bulk liquid, appears at relatively low pressure that is several times lower than the capillary-condensation pressure. The Raman shift of the peak is equal to that of the bulk liquid, although the linewidth is somewhat increased. The peak is attributed to the layers adsorbed beyond the monolayer or to small liquid-like clusters appearing in specific areas of the porous network. The spectroscopic approach presented here demonstrates the ability to detect and estimate small amounts of the liquid-like phase and to distinguish it from the layers strongly interacting with the pore surface.

  19. Solid-phase extraction in combination with dispersive liquid-liquid microextraction and ultra-high performance liquid chromatography-tandem mass spectrometry analysis: the ultra-trace determination of 10 antibiotics in water samples.

    Science.gov (United States)

    Liang, Ning; Huang, Peiting; Hou, Xiaohong; Li, Zhen; Tao, Lei; Zhao, Longshan

    2016-02-01

    A novel method, solid-phase extraction combined with dispersive liquid-liquid microextraction (SPE-DLLME), was developed for ultra-preconcentration of 10 antibiotics in different environmental water samples prior to ultra-high performance liquid chromatography-tandem mass spectrometry detection. The optimized results were obtained as follows: after being adjusted to pH 4.0, the water sample was firstly passed through PEP-2 column at 10 mL min(-1), and then methanol was used to elute the target analytes for the following steps. Dichloromethane was selected as extraction solvent, and methanol/acetonitrile (1:1, v/v) as dispersive solvent. Under optimal conditions, the calibration curves were linear in the range of 1-1000 ng mL(-1) (sulfamethoxazole, cefuroxime axetil), 5-1000 ng mL(-1) (tinidazole), 10-1000 ng mL(-1) (chloramphenicol), 2-1000 ng mL(-1) (levofloxacin oxytetracycline, doxycycline, tetracycline, and ciprofloxacin) and 1-400 ng mL(-1) (sulfadiazine) with a good precision. The LOD and LOQ of the method were at very low levels, below 1.67 and 5.57 ng mL(-1), respectively. The relative recoveries of the target analytes were in the range from 64.16% to 99.80% with relative standard deviations between 0.7 and 8.4%. The matrix effect of this method showed a great decrease compared with solid-phase extraction and a significant value of enrichment factor (EF) compared with dispersive liquid-liquid microextraction. The developed method was successfully applied to the extraction and analysis of antibiotics in different water samples with satisfactory results.

  20. Liquid phase epitaxial growth of GaAs

    Energy Technology Data Exchange (ETDEWEB)

    Wynne, Danielle Ivy [Univ. of California, Berkeley, CA (United States). Materials Science and Mineral Engineering

    1997-10-01

    Research into new semiconductor materials for measurement of electromagnetic radiation over a wide range of energies has been an active field for several decades. There is a strong desire to identify and develop new materials which can lead to improved detectors. Such devices are expected to solve problems that cannot be solved using the semiconductor materials and device structures which have been traditionally used for radiation detection. In order for a detector which is subjected to some type of irradiation to respond, the radiation must undergo an interaction with the detector. The net result of the radiation interaction in a broad category of detectors is the generation of mobile electric charge carriers (electrons and/or holes) within the detector active volume. This charge is collected at the detector contacts and it forms the basic electrical signal. Typically, the collection of the charge is accomplished through the imposition of an electric field within the detector which causes the positive and/or negative charges created by the radiation to flow in opposite directions to the contacts. For the material to serve as a good radiation detector, a large fraction (preferably 100%) of all carriers created by the interacting incident radiation must be collected. Charge trapping by deep level impurities and structural defects can seriously degrade detector performance. The focus of this thesis is on far infrared and X-ray detection. In X-ray detector applications of p-I-n diodes, the object is to measure accurately the energy distribution of the incident radiation quanta. One important property of such detectors is their ability to measure the energy of individual incident photons with high energy resolution.