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Sample records for chemical liquid phase

  1. Chemical Liquid Phase Deposition of Thin Aluminum Oxide Films

    OpenAIRE

    Sun, Jie; Sun, Yingchun

    2007-01-01

    Thin aluminum oxide films were deposited by a new and simple physicochemical method called chemical liquid phase deposition (CLD) on semiconductor materials. Aluminum sulfate with crystallized water and sodium bicarbonate were used as precursors for film growth, and the control of the system pH value played an important role in this experiment. The growth rate is 12 nm/h at room temperature. Post-growth annealing not only densifies and purifies the films, but results in film crystallization a...

  2. Liquid-phase chemical sensing using lateral mode resonant cantilevers.

    Science.gov (United States)

    Beardslee, L A; Demirci, K S; Luzinova, Y; Mizaikoff, B; Heinrich, S M; Josse, F; Brand, O

    2010-09-15

    Liquid-phase operation of resonant cantilevers vibrating in an out-of-plane flexural mode has to date been limited by the considerable fluid damping and the resulting low quality factors (Q factors). To reduce fluid damping in liquids and to improve the detection limit for liquid-phase sensing applications, resonant cantilever transducers vibrating in their in-plane rather than their out-of-plane flexural resonant mode have been fabricated and shown to have Q factors up to 67 in water (up to 4300 in air). In the present work, resonant cantilevers, thermally excited in an in-plane flexural mode, are investigated and applied as sensors for volatile organic compounds in water. The cantilevers are fabricated using a complementary metal oxide semiconductor (CMOS) compatible fabrication process based on bulk micromachining. The devices were coated with chemically sensitive polymers allowing for analyte sorption into the polymer. Poly(isobutylene) (PIB) and poly(ethylene-co-propylene) (EPCO) were investigated as sensitive layers with seven different analytes screened with PIB and 12 analytes tested with EPCO. Analyte concentrations in the range of 1-100 ppm have been measured in the present experiments, and detection limits in the parts per billion concentration range have been estimated for the polymer-coated cantilevers exposed to volatile organics in water. These results demonstrate significantly improved sensing properties in liquids and indicate the potential of cantilever-type mass-sensitive chemical sensors operating in their in-plane rather than out-of-plane flexural modes. PMID:20715842

  3. Chemical Liquid Phase Deposition of Thin Aluminum Oxide Films

    Institute of Scientific and Technical Information of China (English)

    SUN,Jie(孙捷); SUN,Ying-Chun(孙迎春)

    2004-01-01

    Thin aluminum oxide films were deposited by a new and simple physicochemical method called chemical liquid phase deposition (CLD) on semiconductor materials. Aluminum sulfate with crystallized water and sodium bicarbonate were used as precursors for film growth, and the control of the system's pH value played an important role in this experiment. The growth rate is 12 nm/h with the deposition at [Al2(SO4)3]=0.0837 mol·L-1, [NaHCO3]=0.214 mol·L-1, 15 ℃. Post-growth annealing not only densifies and purifies the films, but results in film crystallization as well, Excellent quality of A12O3 films in this work is supported by electron dispersion spectroscopy,Fourier transform infrared spectrum, X-ray diffraction spectrum and scanning electron microscopy photograph.

  4. Laser-assisted chemical liquid-phase deposition of metals for micro- and optoelectronics

    OpenAIRE

    Kordás, K. (Krisztián)

    2002-01-01

    Abstract The demands toward the development of simple and cost-effective fabrication methods of metallic structures with high lateral resolution on different substrates - applied in many fields of technology, such as in microelectronics, optoelectronics, micromechanics as well as in sensor and actuator applications - gave the idea to perform this research. Due to its simplicity, laser-assisted chemical liquid-phase deposition (LCLD) has been investigated and applied for the metallization o...

  5. 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.

  6. 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.

  7. Separation of selected stable isotopes by liquid-phase thermal diffusion and by chemical exchange

    International Nuclear Information System (INIS)

    Useful applications of enriched stable nuclides are unduly restricted by high cost and limited availability. Recent research on liquid phase thermal diffusion (LTD) has resulted in practical processes for separating 34S, 35Cl, and 37Cl in significant quantities (100 to 500 g/yr) at costs much lower than those associated with the electromagnetic (Calutron) process. The separation of the isotopes of bromine by LTD is now in progress and 79Br is being produced in relatively simple equivalent at a rate on the order of 0.5 g/day. The results of recent measurements show that the isotopes of Zn can be separated by LTD of zinc alkyls. The isotopes of calcium can be separated by LTD and by chemical exchange. The LTD process is based on the use of aqueous Ca(NO3)2 as a working fluid. The chemical exchange method involves isotopically selective exchange between an aqueous phase containing a calcium salt and an organic phase containing calcium in the form of a complex with a macrocyclic ligand. The LTD method is suitable for high enrichments at low through-puts; whereas, the chemical exchange techniques is appropriate for lower enrichments at much higher production rates. Current research is directed toward reducing these concepts to practical processes

  8. Chemically driven growth of tungsten grains during liquid phase sintering of W-Ni-Fe alloys

    International Nuclear Information System (INIS)

    In the alloys where the solid grains immersed in liquid matrix grow by Ostwald ripening process, the growth rate can be suddenly altered by changing the matrix composition. In this study, W-Ni-(Fe) specimens have been sintered and annealed at the temperatures around 15000C until the grains have coarsened, and then annealed further after adding Fe or Ni. After adding Fe or Ni and further annealing treatments, strong etching has revealed that a new solid phase in equilibrium with the changed matrix composition has been deposited preferentially on the larger grains. The smaller grains, which would be dissolving continuously, have maintained the old composition. This composition difference between the new solid phase on the larger grains and the old solid phase on the smaller ones can provide a driving force for grain coarsening in addition to that arising from the size difference. When Fe is added to sintered W-Ni, the grain coarsening rate during further annealing momentarily increases. The calculation shows that the molar free energy of the new solid phase should be lower than that of the old solid phase. Therefore, the solution reprecipitation process is ascelerated by this chemical free energy difference. If, on the other hand, Ni is added to sintered W-Ni-Fe, the coarsening rate decreases during further annealing. The calculation shows indeed that in this case the new solid phase should have higher molar free energy than the old. It is therefore demonstrated that if the matrix composition is altered during Ostwald ripening, the grain coarsening can be accelerated or retarded because of the chemical composition difference between the old grains and the newly precipitated solid phase on the larger grains. (author)

  9. Chemical properties of the transactinide elements studied in liquid phase with SISAK

    OpenAIRE

    Omtvedt, J.P.; Alstad, J.; Bjornstad, T.; Dullmann, Ch.E.; Gregorich, K.E.; Hoffman, D C; Nitsche, H.; Opel, K.; Polakova, D.; Samadani, F.; Schulz, F.; Skarnemark, G.; Stavsetra, L.; Sudowe, R.; Zheng, L.

    2008-01-01

    This article starts with a review of the current SISAK liquid-liquid extraction system, as used after the physical preseparator BGS at LBNL for chemical studies of transactinide elements. Emphasis will be on new additions and developments. Then the possibilities offered by the new TASCA separator at GSI and the use of actinide targets at both GSI and LBNL are discussed with respect to future SISAK transactinide experiments. Finally, current and future liquid-liquid extraction systems for...

  10. Research on the pattern of solid-liquid two-phase distribution in chemical process pump

    International Nuclear Information System (INIS)

    In order to explore the pattern of solid-liquid two-phase flow distribution in first stage of double-suction impeller and the double volute channel of the HD type petrol-chemical process pump, the flow field in double-suction impeller and double volute is simulated with the CFD software, by taking the Reynolds Averaged Navier Stokes equations as its governing equations, and the standard k-ε model for turbulence, derives the pattern of solid particle concentration distribution in the impeller and double volute channel under different initial particle concentrations and different particle diameters. The results show that in the double-suction impeller, solid phase distribution changes a lot along with the increase of initial particle concentration; the concentration near the back side is higher than the face side. Solid particles have the motion trend to the back side of blade in double-suction impeller along with the increase of particle diameters. In double volute channel, solid phase concentration distribution is uneven and solid particle concentration is relatively higher from section 1 to section 8. In the diffusion section, concentration is high in lateral side and low in medial side, the solid particles have the motion trend to the lateral side and the solid particle concentration is relatively higher.

  11. Chemical properties of the transactinide elements studied in liquid phase with SISAK

    International Nuclear Information System (INIS)

    This article starts with a review of the current SISAK liquid-liquid extraction system, as used after the physical preseparator BGS at LBNL for chemical studies of transactinide elements. Emphasis will be on new additions and developments. Then the possibilities offered by the new TASCA separator at GSI and the use of actinide targets at both GSI and LBNL are discussed with respect to future SISAK transactinide experiments. Finally, current and future liquid-liquid extraction systems for studying elements Rf up to Hs are discussed

  12. Chemical properties of the trans-actinide elements studied in liquid phase with SISAK

    Energy Technology Data Exchange (ETDEWEB)

    Omtvedt, J.P.; Alstad, J.; Bjornstad, T.; Opel, K.; Polakova, D.; Samadani, F.; Schulz, F.; Stavsetra, L.; Zheng, L. [Oslo Univ., Centre for Accelerator based Research and Energy Physics (SAFE) (Norway); Dullmann, Ch.E; Gregorich, K.E.; Hoffman, D.C.; Nitsche, H.; Sudowe, R. [Lawrence Berkeley National Laboratory (LBNL), Nuclear Science Div., One Cyclotron Road, Berkeley, CA (United States); Dullmann, Ch.E.; Hoffman, D.C.; Nitsche, H. [California Univ., Dept. of Chemistry, Berkeley, CA (United States); Skarnemark, G. [Chalmers Univ. of Technology, Nuclear Chemistry, Dept. of Chemical and Biological Engineering (Sweden)

    2007-10-15

    This article starts with a review of the current SISAK liquid-liquid extraction system, as used after the physical pre-separator BGS (Berkeley Gas-filled Separator) at Lawrence Berkeley National Laboratory (LBNL) for chemical studies of trans-actinide elements. Emphasis will be on new additions and developments. Then the possibilities offered by the new TASCA (Trans-Actinide Separator and Chemistry Apparatus) separator at GSI (Darmstadt, Germany) and the use of actinide targets at both GSI and LBNL are discussed with respect to future SISAK trans-actinide experiments. Finally, current and future liquid-liquid extraction systems for studying elements Rutherfordium up to Hassium are discussed. (authors)

  13. Chemical properties of the trans-actinide elements studied in liquid phase with SISAK

    International Nuclear Information System (INIS)

    This article starts with a review of the current SISAK liquid-liquid extraction system, as used after the physical pre-separator BGS (Berkeley Gas-filled Separator) at Lawrence Berkeley National Laboratory (LBNL) for chemical studies of trans-actinide elements. Emphasis will be on new additions and developments. Then the possibilities offered by the new TASCA (Trans-Actinide Separator and Chemistry Apparatus) separator at GSI (Darmstadt, Germany) and the use of actinide targets at both GSI and LBNL are discussed with respect to future SISAK trans-actinide experiments. Finally, current and future liquid-liquid extraction systems for studying elements Rutherfordium up to Hassium are discussed. (authors)

  14. 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.

  15. Heterogeneous Catalytic Conversion of Biobased Chemicals into Liquid Fuels in the Aqueous Phase.

    Science.gov (United States)

    Wu, Kejing; Wu, Yulong; Chen, Yu; Chen, Hao; Wang, Jianlong; Yang, Mingde

    2016-06-22

    Different biobased chemicals are produced during the conversion of biomass into fuels through various feasible technologies (e.g., hydrolysis, hydrothermal liquefaction, and pyrolysis). The challenge of transforming these biobased chemicals with high hydrophilicity is ascribed to the high water content of the feedstock and the inevitable formation of water. Therefore, aqueous-phase processing is an interesting technology for the heterogeneous catalytic conversion of biobased chemicals. Different reactions, such as dehydration, isomerization, aldol condensation, ketonization, and hydrogenation, are applied for the conversion of sugars, furfural/hydroxymethylfurfural, acids, phenolics, and so on over heterogeneous catalysts. The activity, stability, and reusability of the heterogeneous catalysts in water are summarized, and deactivation processes and several strategies are introduced to improve the stability of heterogeneous catalysts in the aqueous phase. PMID:27158985

  16. Phase transition and chemical decomposition of liquid carbon dioxide and nitrogen mixture under extreme conditions

    Science.gov (United States)

    Xiao-Xu, Jiang; Guan-Yu, Chen; Yu-Tong, Li; Xin-Lu, Cheng; Cui-Ming, Tang

    2016-02-01

    Thermodynamic and chemical properties of liquid carbon dioxide and nitrogen (CO2-N2) mixture under the conditions of extremely high densities and temperatures are studied by using quantum molecular dynamic (QMD) simulations based on density functional theory including dispersion corrections (DFT-D). We present equilibrium properties of liquid mixture for 112 separate density and temperature points, by selecting densities ranging from ρ = 1.80 g/cm3 to 3.40 g/cm3 and temperatures from T = 500 K to 8000 K. In the range of our study, the liquid CO2-N2 mixture undergoes a continuous transition from molecular to atomic fluid state and liquid polymerization inferred from pair correlation functions (PCFs) and the distribution of various molecular components. The insulator-metal transition is demonstrated by means of the electronic density of states (DOS). Project supported by the National Natural Science Foundation of China (Grant Nos. 11374217, 11135012, and 11375262) and the Joint Fund of the National Natural Science Foundation of China and the China Academy of Engineering Physics (Grant No. 11176020).

  17. Ultra resolution chemical fingerprinting of dense non-aqueous phase liquids from manufactured gas plants by reversed phase comprehensive two-dimensional gas chromatography.

    Science.gov (United States)

    McGregor, Laura A; Gauchotte-Lindsay, Caroline; Daéid, Niamh Nic; Thomas, Russell; Daly, Paddy; Kalin, Robert M

    2011-07-22

    Ultra resolution chemical fingerprinting of dense non-aqueous phase liquids (DNAPLs) from former manufactured gas plants (FMGPs) was investigated using comprehensive two-dimensional gas chromatography coupled with time of flight mass spectrometry (GC×GC TOFMS). Reversed phase GC×GC (i.e. a polar primary column coupled to a non-polar secondary column) was found to significantly improve the separation of polycyclic aromatic hydrocarbons (PAHs) and their alkylated homologues. Sample extraction and cleanup was performed simultaneously using accelerated solvent extraction (ASE), with recovery rates between 76% and 97%, allowing fast, efficient extraction with minimal solvent consumption. Principal component analysis (PCA) of the GC×GC data was performed in an attempt to differentiate between twelve DNAPLs based on their chemical composition. Correlations were discovered between DNAPL composition and historic manufacturing processes used at different FMGP sites. Traditional chemical fingerprinting methods generally follow a tiered approach with sample analysis on several different instruments. We propose ultra resolution chemical fingerprinting as a fast, accurate and precise method of obtaining more chemical information than traditional tiered approaches while using only a single analytical technique. PMID:21652041

  18. Investigation of surfactant-enhanced dissolution of entrapped nonaqueous phase liquid chemicals in a two-dimensional groundwater flow field.

    Science.gov (United States)

    Saba, T; Illangasekare, T H; Ewing, J

    2001-09-01

    Because of their low solubility, waste chemicals in the form of nonaqueous phase liquids (NAPLs) that are entrapped in subsurface formations act as long-term sources of groundwater contamination. In the design of remediation schemes that use surfactants, it is necessary to estimate the mass transfer rate coefficients under multi-dimensional flow fields that exit at field sites. In this study, we investigate mass transfer under a two-dimensional flow field to obtain an understanding of the basic mechanisms of surfactant-enhanced dissolution and to quantify the mass transfer rates. Enhanced dissolution experiments in a two-dimensional test cell were conducted to measure rates of mass depletion from entrapped NAPLs to a flowing aqueous phase containing a surfactant. In situ measurement of transient saturation changes using a gamma attenuation system revealed dissolution patterns that are affected by the dimensionality of the groundwater flow field. Numerical modeling of local flow fields that changed with time, due to depletion of NAPL sources, enabled the examination of the basic mechanisms of NAPL dissolution in complex groundwater systems. Through nonlinear regression analysis, mass transfer rates were correlated to porous media properties, NAPL saturation and aqueous phase velocity. Results from the experiments and numerical analyses were used to identify deficiencies in existing methods of analysis that uses assumptions of one-dimensional flow, homogeneity of aquifer properties, local equilibrium and idealized transient mass transfer. PMID:11530927

  19. Chemical studies on the treatment of hazardous liquid wastes by Two-phase transfer

    International Nuclear Information System (INIS)

    Phosphate fertilizers produced from phosphate industries are one of the main sources of cadmium and other heavy metals in agricultural soils. Wastewater produced from phosphate industries and released in the water streams is highly acidic and contaminated with heavy metals which have severe environmental impacts. Phosphoric acid produced from phosphate ores by wet process contains small amounts of uranium together with some heavy metals. The presence of heavy metals represent a nuclear poison for using uranium as nuclear fuel. Therefore, the extraction of these elements from phosphoric acid produced by this process is necessary for the recovery of high purity uranium. The extraction of these elements from phosphate medium is of major importance where phosphate solution is a common species in radioactive waste solutions. The main trends to remove these elements are to use precipitation, ion exchange and liquid-liquid extraction. 9 tabs., 64 figs., 113 refs

  20. Antimicrobial properties and chemical composition of liquid and gaseous phases of essential oils

    OpenAIRE

    Křůmal, K. (Kamil); Kubátková, N. (Nela); Večeřa, Z. (Zbyněk); Mikuška, P. (Pavel)

    2015-01-01

    The antimicrobial properties of fifteen essential oils (EOs) tested on seventeen microorganisms were determined using the vapour–agar contact method. The most effective EOs (i.e. Lavandula angustifolia, Cymbopogon nardus, Citrus aurantifolia, Juniperus communis, Myrtus communis and Cinnamomum zeylanicum), whose volatile components afforded the best antimicrobial properties, were selected for a detailed study of chemical composition. All these six EOs contained one to three main component...

  1. Retention behavior of polycyclic aromatic hydrocarbons in supercritical fluid chromatography on a chemically bonded stationary phases based upon liquid-crystalline polymer

    Energy Technology Data Exchange (ETDEWEB)

    Gritti [Bordeaux I Univ., Pessac (France). INSCPB; Bordeaux I Univ., Pessac (France). CRPP; Felix, G. [Bordeaux I Univ., Pessac (France). INSCPB; Achard, M.F.; Hardouin, F. [Bordeaux I Univ., Pessac (France). CRPP

    2001-02-01

    The retention behavior of a set of polycyclic hydrocarbons in supercritical fluid chromatography have been studied on a chemically bonded stationary phase based upon a side chain liquid crystalline polymer (LCP) with carbon dioxide-based mobile phase. The effects of the mobile phase pressure, column temperature and amount of mobile phase organic modifier have been investigated in order to detect a possible structural change in the liquid crystal polymer linked to the silica support. The influence of these factors on the selectivity coefficients has also been studied. Two distinctive behaviors with temperature are noted at low pressure on the one hand and at higher pressure on the other. This change in behavior is based on the density of the supercritical CO{sub 2} and the PAH volatility rather than on any specific stationary phase structural change. Both lower mobile phase pressure and amount of mobile phase modifier are required to obtain better selectivities. Better planarity recognition is observed in SFC than in HPLC with these new bonded liquid crystal stationary phases. The bonded liquid crystal phase is only weakly affected by the addition of organic modifier in the supercritical CO{sub 2}. (orig.)

  2. Broad-Spectrum Liquid- and Gas-Phase Decontamination of Chemical Warfare Agents by One-Dimensional Heteropolyniobates.

    Science.gov (United States)

    Guo, Weiwei; Lv, Hongjin; Sullivan, Kevin P; Gordon, Wesley O; Balboa, Alex; Wagner, George W; Musaev, Djamaladdin G; Bacsa, John; Hill, Craig L

    2016-06-20

    A wide range of chemical warfare agents and their simulants are catalytically decontaminated by a new one-dimensional polymeric polyniobate (P-PONb), K12 [Ti2 O2 ][GeNb12 O40 ]⋅19 H2 O (KGeNb) under mild conditions and in the dark. Uniquely, KGeNb facilitates hydrolysis of nerve agents Sarin (GB) and Soman (GD) (and their less reactive simulants, dimethyl methylphosphonate (DMMP)) as well as mustard (HD) in both liquid and gas phases at ambient temperature and in the absence of neutralizing bases or illumination. Three lines of evidence establish that KGeNb removes DMMP, and thus likely GB/GD, by general base catalysis: a) the k(H2 O)/k(D2 O) solvent isotope effect is 1.4; b) the rate law (hydrolysis at the same pH depends on the amount of P-PONb present); and c) hydroxide is far less active against the above simulants at the same pH than the P-PONbs themselves, a critical control experiment. PMID:27061963

  3. Phase inversion in dispersed liquid-liquid pipe flow

    OpenAIRE

    Ngan, K. H.

    2011-01-01

    This thesis presents the experimental and theoretical investigations on the development of phase inversion in horizontal pipeline flow of two immiscible liquids. It aims to provide an understanding on the flow development across the phase inversion transition as well as the effect on pressure drop. Experimental investigation on phase inversion and associated phenomena were conducted in a 38mm I.D. liquid pipeline flow facility available in the Department of Chemical Engineer...

  4. Analysis of chemical warfare agents in organic liquid samples with magnetic dispersive solid phase extraction and gas chromatography mass spectrometry for verification of the chemical weapons convention.

    Science.gov (United States)

    Singh, Varoon; Purohit, Ajay Kumar; Chinthakindi, Sridhar; Goud, Raghavender D; Tak, Vijay; Pardasani, Deepak; Shrivastava, Anchal Roy; Dubey, Devendra Kumar

    2016-05-27

    A simple, sensitive and low temperature sample preparation method is developed for detection and identification of Chemical Warfare Agents (CWAs) and scheduled esters in organic liquid using magnetic dispersive solid phase extraction (MDSPE) followed by gas chromatography-mass spectrometry analysis. The method utilizes Iron oxide@Poly(methacrylic acid-co-ethylene glycol dimethacrylate) resin (Fe2O3@Poly(MAA-co-EGDMA)) as sorbent. Variants of these sorbents were prepared by precipitation polymerization of methacrylic acid-co-ethylene glycol dimethacrylate (MAA-co-EGDMA) onto Fe2O3 nanoparticles. Fe2O3@poly(MAA-co-EGDMA) with 20% MAA showed highest recovery of analytes. Extractions were performed with magnetic microspheres by MDSPE. Parameters affecting the extraction efficiency were studied and optimized. Under the optimized conditions, method showed linearity in the range of 0.1-3.0μgmL(-1) (r(2)=0.9966-0.9987). The repeatability and reproducibility (relative standard deviations (RSDs) %) were in the range of 4.5-7.6% and 3.4-6.2% respectively for organophosphorous esters in dodecane. Limits of detection (S/N=3/1) and limit of quantification (S/N=10/1) were found to be in the range of 0.05-0.1μgmL(-1) and 0.1-0.12μgmL(-1) respectively in SIM mode for selected analytes. The method was successfully validated and applied to the extraction and identification of targeted analytes from three different organic liquids i.e. n-hexane, dodecane and silicon oil. Recoveries ranged from 58.7 to 97.3% and 53.8 to 95.5% at 3μgmL(-1) and 1μgmL(-1) spiking concentrations. Detection of diethyl methylphosphonate (DEMP) and O-Ethyl S-2-diisopropylaminoethyl methylphosphonothiolate (VX) in samples provided by the Organization for Prohibition of Chemical Weapons Proficiency Test (OPCW-PT) proved the utility of the developed method for the off-site analysis of CWC relevant chemicals. PMID:27113675

  5. Liquid and vapour-phase antifungal activities of selected essential oils against candida albicans: microscopic observations and chemical characterization of cymbopogon citratus

    Directory of Open Access Journals (Sweden)

    Malik Anushree

    2010-11-01

    Full Text Available Abstract Background Use of essential oils for controlling Candida albicans growth has gained significance due to the resistance acquired by pathogens towards a number of widely-used drugs. The aim of this study was to test the antifungal activity of selected essential oils against Candida albicans in liquid and vapour phase and to determine the chemical composition and mechanism of action of most potent essential oil. Methods Minimum Inhibitory concentration (MIC of different essential oils in liquid phase, assayed through agar plate dilution, broth dilution & 96-well micro plate dilution method and vapour phase activity evaluated through disc volatilization method. Reduction of C. albicans cells with vapour exposure was estimated by kill time assay. Morphological alteration in treated/untreated C. albicans cells was observed by the Scanning electron microscopy (SEM/Atomic force microscopy (AFM and chemical analysis of the strongest antifungal agent/essential oil has been done by GC, GC-MS. Results Lemon grass (Cymbopogon citratus essential oil exhibited the strongest antifungal effect followed by mentha (Mentha piperita and eucalyptus (Eucalyptus globulus essential oil. The MIC of lemon grass essential oil in liquid phase (288 mg/l was significantly higher than that in the vapour phase (32.7 mg/l and a 4 h exposure was sufficient to cause 100% loss in viability of C. albicans cells. SEM/AFM of C. albicans cells treated with lemon grass essential oil at MIC level in liquid and vapour phase showed prominent shrinkage and partial degradation, respectively, confirming higher efficacy of vapour phase. GC-MS analysis revealed that lemon grass essential oil was dominated by oxygenated monoterpenes (78.2%; α-citral or geranial (36.2% and β-citral or neral (26.5%, monoterpene hydrocarbons (7.9% and sesquiterpene hydrocarbons (3.8%. Conclusion Lemon grass essential oil is highly effective in vapour phase against C. albicans, leading to deleterious

  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. Advances in liquid phase technology

    Energy Technology Data Exchange (ETDEWEB)

    Jijin, P.J.A. [Air Products and Chemicals, Inc., Allentown, PA (United States)

    1997-12-31

    The liquid phase methanol (LPMEOH) process uses a slurry reactor to convert synthesis gas (primarily a mixture of hydrogen and carbon monoxide) to methanol. Through its superior heat management, the process is ultimately suitable to handle synthesis gas generated through gasification of natural gas and other materials, such as coal, petroleum coke, residual oil, wastes and other environmentally disadvantaged hydrocarbon feedstocks. Apart from production of chemical grade methanol, the process provides economic advantages in the Integrated Gasification Combined Cycle (IGCC) power generation application. Coproduction of power and methanol via the IGCC and the LPMEOH process provides opportunities for energy storage for peak-shaving of electrical demand and/or clean fuel for export. The LPMEOH technology has been developed since the 1980`s, extensively proven in a process development unit in LaPorte, Texas and elected for demonstration under The Clean Coal Technology Program. The slurry reactor being demonstrated is also suitable for other exothermic synthesis gas conversion reactions, like synthesis of Dimethyl Ether and other alcohols/oxygenates. This paper presents an overview of LPMEOH and other liquid phase technology aspects and highlights the demonstration project at Eastman Chemical Company`s coal gasification facility in Kingsport, Tennessee. Commercial aspects of the LPMEOH process are also discussed.

  8. Performing protein crosslinking using gas-phase cleavable chemical crosslinkers and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Argo, Andrew S; Shi, Chunxiao; Liu, Fan; Goshe, Michael B

    2015-11-01

    In this article, we describe our methods and protocols using collision-induced dissociative chemical crosslinking-tandem mass spectrometry (CID-CXL-MS/MS) analysis and the practical considerations when implementing these reagents and methodology for protein crosslinking studies. The synthesis of our novel chemical crosslinkers is described as well as their use for effectively labeling protein and protein complexes. Several sample preparation methods for liquid chromatography-tandem mass spectrometry are provided including the enrichment of interpeptide crosslinks. For identification of CID-CXL-MS/MS crosslinks, details regarding MS acquisition parameters and the utilization of various mass spectrometers are addressed along with post-data acquisition analysis to identify interpeptide crosslinks. Once the CID-CXL-MS/MS approach is optimized for a protein target or a set of targets, it can be used as a tool for biological research for studying protein structure when integrated with data obtained using other techniques, such as NMR, X-ray crystallography, and cryo-electron microscopy, or extended to the study of protein-protein interactions in physiological environments. PMID:26091612

  9. Liquid phase chromatography on microchips

    DEFF Research Database (Denmark)

    Kutter, Jörg Peter

    2012-01-01

    almost 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......Over the past twenty years, the field of microfluidics has emerged providing one of the main enabling technologies to realize miniaturized chemical analysis systems, often referred to as micro-Total Analysis Systems (uTAS), or, more generally, Lab-on-a-Chip Systems (LOC) [1,2]. While microfluidics...... was driven forward a lot from the engineering side, especially with respect to ink jet and dispensing technology, the initial push and interest from the analytical chemistry community was through the desire to develop miniaturized sensors, detectors, and, very early on, separation systems. The initial...

  10. Advances in Liquid Phase{trademark} technology

    Energy Technology Data Exchange (ETDEWEB)

    Miller, W.R.; Heydorn, E.C.; Moore, R.B.; Tijm, P.J.A.

    1998-04-01

    The {open_quotes}Liquid Phase{trademark} Technology{close_quotes} builds on the successful development by Air Products and Chemicals, Inc. of the slurry phase bubble column technology. Air Products and Chemicals Liquid Phase{trademark} technology embodies several chemical processes including Liquid Phase Methanol{trademark} (LPMEOH{trademark}) and the Liquid Phase DiMethyl Ether{trademark} (LPDME{trademark}) and other alcohols/oxygenates. The LPMEOH{trademark} technology was developed during the 1980`s with the financial support of the U.S. Department of Energy (DOE). The concept was proven in over 7,400 hours of test operation in a DOE-owned, 3,200 gallons (U.S.) of methanol per day process development unit located at LaPorte, Texas. The first commercial-scale demonstration plant for the technology has been constructed, commissioned, and is now being operated at Eastman Chemical Company`s coal gasification facility in Kingsport, Tennessee under the DOE`s Clean Coal Technology Program. Construction began in October of 1995 and was completed in January of 1997. After commissioning and startup activities were completed, operation began in April of 1997. Currently, the LPMEOH{trademark} plant is producing 80,000 gallons of methanol per day. Over the next four years, a program of operation will demonstrate the commercial advantages of the technology to include simulations of the integrated gasification combined cycle (IGCC) coproduction of power and methanol application. Air Products and Eastman formed the {open_quotes}Air Products Liquid Phase Conversion Co., L.P.{close_quotes} partnership to execute the commercial-scale demonstration project. Most of the product methanol is refined to chemical-grade quality (99.85 wt% purity via distillation) and used by Eastman as chemical feedstock in the commercial facility. A portion of the product methanol will be withdrawn prior to purification (about 98 wt% purity) and used in off-site product-use tests.

  11. Advances in Liquid Phase{trademark} technology

    Energy Technology Data Exchange (ETDEWEB)

    Miller, W.R.; Heydorn, E.C.; Moore, R.B.; Tijm, P.J.A.

    1998-07-01

    The Liquid Phase{trademark} Technology builds on the successful development by Air Products and Chemicals, Inc. of the slurry phase bubble column technology. Air Products and Chemicals Liquid Phase{trademark} technology embodies several chemical processes including Liquid Phase Methanol{trademark} (LPMEOH{trademark}) and the Liquid Phase DiMethyl Ether{trademark} (LPDME{trademark}) and other alcohols/oxygenates. The LPMEOH{trademark} technology was developed during the 1980's with the financial support of the US department of Energy (DOE). The concept was proven in over 7,400 hours of test operation in a DOE-owned, 3,200 gallons (US) of methanol per day process development unit located at LaPorte, Texas. The first commercial-scale demonstration plant for the technology has been constructed, commissioned, and is now being operated at Eastman Chemical Company's coal gasification facility in Kingsport, Tennessee under the DOE's Clean Coal Technology Program. Construction began in October of 1995 and was completed in January of 1997. After commissioning and startup activities were completed, operation began in April of 1997. Currently, the LPMEOH{trademark} plant is producing 80,000 gallons of methanol per day. Over the next four years, a program of operation will demonstrate the commercial advantages of the technology to include simulations of the integrated gasification combined cycle (IGCC) coproduction of power and methanol application. This paper reviews the: Commercial Application for the LPMEOH{trademark} process technology; Operational Plans to demonstrate the commercial advantages of the plant; LPMEOH{trademark} Plant-Status, highlighting the integration of the LPMEOH{trademark} plant at Kingsport, and the accomplishments during the initial operating period; and Highlights of other Liquid Phase{trademark} Technology Developments.

  12. The influence of a non-aqueous phase liquid (NAPL) and chemical oxidant application on perfluoroalkyl acid (PFAA) fate and transport.

    Science.gov (United States)

    McKenzie, Erica R; Siegrist, Robert L; McCray, John E; Higgins, Christopher P

    2016-04-01

    One dimensional column experiments were conducted using saturated porous media containing residual trichloroethylene (TCE) to understand the effects of non-aqueous phase liquids (NAPLs) and chemical oxidation on perfluoroalkyl acid (PFAA) fate and transport. Observed retardation factors and data from supporting batch studies suggested that TCE provides additional sorption capacity that can increase PFAA retardation (i.e., decreased mobility), though the mechanisms remain unclear. Treatment with persulfate activated with FeCl2 and citric acid, catalyzed hydrogen peroxide (CHP), or permanganate did not result in oxidative transformations of PFAAs. However, impacts on PFAA sorption were apparent, and enhanced sorption was substantial in the persulfate-treated columns. In contrast, PFAA transport was accelerated in permanganate- and CHP-treated columns. Ultimately, PFAA transport in NAPL contaminated groundwater is likely influenced by porous media properties, NAPL characteristics, and water quality properties, each of which can change due to chemical oxidant treatment. For contaminated sites for which ISCO is a viable treatment option, changes to PFAA transport and the implications thereof should be included as a component of the remediation evaluation and selection process. PMID:26854608

  13. Chemical Corrosion of Liquid-Phase Sintered SiC in Acidic/Alkaline Solutions Part 1. Corrosion in HNO3 Solution

    Science.gov (United States)

    Zhang, Lei; Zhang, Ming; He, Xinnong; Tang, Wenming

    2016-03-01

    The corrosion behavior of the liquid-phase sintered SiC (LPS-SiC) was studied by dipping in 3.53 mol/L HNO3 aqueous solution at room temperature and 70 °C, respectively. The weight loss, strength reduction and morphology evolution of the SiC specimens during corroding were revealed and also the chemical corrosion process and mechanism of the SiC specimens in the acidic solution were clarified. The results show that the corrosion of the LPS-SiC specimens in the HNO3 solution is selective. The SiC particles are almost free from corrosion, but the secondary phases of BaAl2Si2O8 (BAS) and Y2Si2O7 are corroded via an acid-alkali neutralization reaction. BAS has a higher corrosion rate than Y2Si2O7, resulting in the formation of the bamboo-leaf-like corrosion pits. As the SiC specimens etched in the HNO3 solution at room temperature for 75 days, about 80 μm thickness corrosion layer forms. The weight loss and bending strength reduction of the etched SiC specimens are 2.6 mg/cm2 and 52%, respectively. The corrosion of the SiC specimens is accelerated in the 70 °C HNO3 solution with a rate about five times bigger than that in the same corrosion medium at room temperature.

  14. Liquid-Phase Adsorption Fundamentals.

    Science.gov (United States)

    Cooney, David O.

    1987-01-01

    Describes an experiment developed and used in the unit operations laboratory course at the University of Wyoming. Involves the liquid-phase adsorption of an organic compound from aqueous solution on activated carbon, and is relevant to adsorption processes in general. (TW)

  15. Cholesteric bonded stationary phases for high performance liquid chromatography II: synthesis, physico-chemical characterization and chromatographic behavior of a phospho-cholesteric bonded support. A new way to mimic drug/membrane interactions?

    OpenAIRE

    Courtois, Cédric; Allais, Christophe; Constantieux, Thierry; Rodriguez, Jean; Caldarelli, Stefano; Delaurent, Corinne

    2008-01-01

    International audience Among the various methods exploitable to deter- mine the bioavailability of drugs, reversed-phase liquid chromatography (RPLC) appears to be suited to creation of patterns of prediction. In this context a new stationary phase was designed in this work to reproduce, in terms of chemical structure, as accurately as possible, the main elements of cellular membranes; which include phospholipids and cho- lesterol molecules. An efficient synthetic pathway was developed to ...

  16. In Situ Microfocus Chemical Computed Tomography of the Composition of a Single Catalyst Particle During Hydrogenation of Nitrobenzene in the Liquid Phase.

    OpenAIRE

    Price, S. W.; Geraki, K.; Ignatyev, K.; Witte, P.T.; Beale, A.M.; Mosselmans, J. F.

    2015-01-01

    Heterogeneous catalysis performed in the liquid phase is an important type of catalytic process which is rarely studied in situ. Using microfocus X-ray fluorescence and X-ray diffraction computed tomography (μ-XRF-CT, μ-XRD-CT) in combination with X-ray absorption near-edge spectroscopy (XANES), we have determined the active state of a Mo-promoted Pt/C catalyst (NanoSelect) for the liquid-phase hydrogenation of nitrobenzene under standard operating conditions. First, μ-XRF-CT and μ-XRD-CT rev...

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

    International Nuclear Information System (INIS)

    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 T0, and obtain the parametric phase diagram of the Hamaker constant vs the coupling strength or, at given surface potential, the particle size. By imposing T0 to be the critical temperature Tc, i.e., setting kBT0 (=kBTc) 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 transition

  18. Ionic Liquids: Green Solvents for Chemical Processing

    OpenAIRE

    Antonia Pérez de los Ríos; Angel Irabien; Frank Hollmann; Francisco José Hernández Fernández

    2013-01-01

    Ionic liquids are organic salts, usually consisting of an organic cation and a polyatomic inorganic anion, which are liquid under 100∘ C. The most relevant properties of ionic liquids are their almost negligible vapour pressure. Furthermore, their physical and chemical properties can be fine-tuned by the adequate selection of the cation and anion constituents. Ionic liquids have been recognized as environmental benign alternative to volatile organic solvents. Applicati...

  19. Modelling of retention of pesticides in reversed-phase high-performance liquid chromatography: Quantitative structure-retention relationships based on solute quantum-chemical descriptors and experimental (solvatochromic and spin-probe) mobile phase descriptors

    International Nuclear Information System (INIS)

    A quantitative structure-retention relationship (QSRR) analysis based on multilinear regression (MLR) and artificial neural networks (ANNs) is carried out to model the combined effect of solute structure and eluent composition on the retention behaviour of pesticides in isocratic reversed-phase high-performance liquid chromatography (RP-HPLC). The octanol-water partition coefficient and four quantum chemical descriptors (the total dipole moment, the mean polarizability, the anisotropy of the polarizability and a descriptor of hydrogen-bonding based on the atomic charges on acidic and basic chemical functionalities) are considered as solute descriptors. In order to identify suitable mobile phase descriptors, encoding composition-dependent properties of both methanol- and acetonitrile-containing mobile phases, the Kamlet-Taft solvatochromic parameters (polarity-dipolarity, hydrogen-bond acidity and hydrogen-bond basicity, π *, α and β, respectively) and the 14N hyperfine-splitting constant (a N) of a spin-probe dissolved in the eluent are examined. A satisfactory description of mobile phase properties influencing the solute retention is provided by a N and β or alternatively π * and β. The two seven-parameter models resulting from combination of a N and β, or π * and β, with the solute descriptors were tested on a set of 26 pesticides representative of 10 different chemical classes in a wide range of mobile phase composition (30-60% (v/v) water-methanol and 30-70% (v/v) water-acetonitrile). Within the explored experimental range, the acidity of the eluent, as quantified by α, is almost constant, and this parameter is in fact irrelevant. The results reveal that a N and π *, that can be considered as interchangeable mobile phase descriptors, are the most influent variables in the respective models. The predictive ability of the proposed models, as tested on an external data set, is quite good (Q 2 close to 0.94) when a MLR approach is used, but the modelling

  20. Liquid phase sintered superconducting cermet

    International Nuclear Information System (INIS)

    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 RM2Cu3O(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

  1. Liquid and vapour-phase antifungal activities of selected essential oils against candida albicans: microscopic observations and chemical characterization of cymbopogon citratus

    OpenAIRE

    Malik Anushree; Tyagi Amit K

    2010-01-01

    Abstract Background Use of essential oils for controlling Candida albicans growth has gained significance due to the resistance acquired by pathogens towards a number of widely-used drugs. The aim of this study was to test the antifungal activity of selected essential oils against Candida albicans in liquid and vapour phase and to determine the chemical composition and mechanism of action of most potent essential oil. Methods Minimum Inhibitory concentration (MIC) of different essential oils ...

  2. Phase-field simulation of liquid phase migration in the WC-Co system during liquid phase sintering

    International Nuclear Information System (INIS)

    Liquid phase sintering is a process for forming high performance, multiple-phase components from powders. The process includes very complex interactions between various mass transportation phenomena, among which the liquid phase migration represents an important one in the aspect of forming a gradient structure in cemented carbide. In the present work, phase-field simulation of the liquid phase migration phenomenon during liquid phase sintering is performed in the WC-Co based cemented carbide. The simulation results are analyzed and compared with the experimentally determined key factors of microstructural evolution, such as contiguity and liquid phase migration rate. The diffusion-controlled solution-precipitation mechanism of the liquid phase migration process in the cemented carbide system is confirmed from the current simulation result, which provides deeper understanding of the microstructural evolution during the liquid phase migration process. These simulations can offer guidance in preventing the liquid phase migration process during liquid phase sintering of cellular cemented carbide.

  3. Phase-field simulation of liquid phase migration in the WC-Co system during liquid phase sintering

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Kaiming; Zhang, Lijun; Du, Yong [Central South Univ., Changsha (China). State Key Lab. of Powder Metallurgy; Schwarze, Christian; Steinbach, Ingo [Bochum Univ. (Germany). Interdisciplinary Centre for Advanced Materials Simulation

    2016-04-15

    Liquid phase sintering is a process for forming high performance, multiple-phase components from powders. The process includes very complex interactions between various mass transportation phenomena, among which the liquid phase migration represents an important one in the aspect of forming a gradient structure in cemented carbide. In the present work, phase-field simulation of the liquid phase migration phenomenon during liquid phase sintering is performed in the WC-Co based cemented carbide. The simulation results are analyzed and compared with the experimentally determined key factors of microstructural evolution, such as contiguity and liquid phase migration rate. The diffusion-controlled solution-precipitation mechanism of the liquid phase migration process in the cemented carbide system is confirmed from the current simulation result, which provides deeper understanding of the microstructural evolution during the liquid phase migration process. These simulations can offer guidance in preventing the liquid phase migration process during liquid phase sintering of cellular cemented carbide.

  4. Ionic Liquids as Mobile Phase Additives for Separation of Nucleotides in High-Performance Liquid Chromatography

    Institute of Scientific and Technical Information of China (English)

    ZHANG,Wen-Zhu(张文珠); HE,Li-Jun(何丽君); LIU,Xia(刘霞); JIANG,Sheng-Xiang(蒋生祥)

    2004-01-01

    Ionic liquids are a type of salts that are liquid at low temperature (< 100 ℃). Because of their some special properties, they have been widely used as new "green solvents" for many chemical reactions and liquid-liquid extraction in the past several years. In this paper, a new method for the separation of nucleotides is developed and the essential feature of the method is that 1-alkyl-3-methylimidazolium salts are used as mobile phase additives, resulting in a baseline separation of nucleotides without need of gradient elution and need of organic solvent addition as currently used in RP-HPLC. This study shows the potential application of ionic liquids as mobile phase additives in reversed-phase liquid chromatography.

  5. Study of liquid phase formation kinetics due to solid/solid chemical interaction and its model. Application to the Zircaloy/Inconel

    International Nuclear Information System (INIS)

    A description is made of the chemical interaction between Inconel spacing grids and the Zircaloy of the sheaths. Experiments performed at 1000, 1100 and 1200 deg C with base Zircaloy and with a previously formed layer of ZrO2, show that the kinetics is parabolic. The difference between both types of experiments is that the oxide layer delays the initiation of the Inconel-Zry interaction. A model is presented, for the description of the solid/solid interaction, which leads to the formation of eutectic that is liquid at the experiment temperature. Also a model, which represents the oxide layer dissolution and predicts the instant in which it disappears completely, is presented. (Author)

  6. 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 catalyt...... performance, i.e. activity and selectivity, as well as stability of the SILP catalysts. Noticeably, a high catalyst ligand content together with presence of ionic liquid solvent are prerequisites for obtaining selective rhodium phosphine SILP catalysts systems.......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...

  7. Evaluation of hydrodynamic factors on flow accelerated corrosion in gas-liquid two phase flow and construction of equation for mass transfer coefficient. Part 4. Effect of hydrodynamic and water chemical factors on flow accelerated corrosion in two phase flow

    International Nuclear Information System (INIS)

    Flow accelerated corrosion (FAC) experiments under water-steam two phase flow are performed to understand the effects of liquid film thickness and temperature, pH on thinning rate. The effects of temperature and pH on the thinning rates are almost the same as that of the prediction model of thinning rate of FAC under two phase flow. However, the effect of film thickness is different from the prediction model, so that it is suggested that the prediction model should improve the effect of film thickness. And then, these experimental results are compared with prediction thinning rates. These prediction thinning rates are higher than that of experiment rates when the water is alkali by ammonia and liquid film thickness is thin. It is suggested that the prediction model is improved and the accuracy of pH in liquid film is improved. (author)

  8. Randomized Grain Boundary Liquid Crystal Phase

    Science.gov (United States)

    Chen, D.; Wang, H.; Li, M.; Glaser, M.; Maclennan, J.; Clark, N.

    2012-02-01

    The formation of macroscopic, chiral domains, in the B4 and dark conglomerate phases, for example, is a feature of bent-core liquid crystals resulting from the interplay of chirality, molecular bend and molecular tilt. We report a new, chiral phase observed in a hockey stick-like liquid crystal molecule. This phase appears below a smectic A phase and cools to a crystal phase. TEM images of the free surface of the chiral phase show hundreds of randomly oriented smectic blocks several hundred nanometers in size, similar to those seen in the twist grain boundary (TGB) phase. However, in contrast to the TGB phase, these blocks are randomly oriented. The characteristic defects in this phase are revealed by freeze-fracture TEM images. We will show how these defects mediate the randomized orientation and discuss the intrinsic mechanism driving the formation of this phase. This work is supported by NSF MRSEC Grant DMR0820579 and NSF Grant DMR0606528.

  9. Phase changes in liquid face seals

    Science.gov (United States)

    Hughes, W. F.

    1980-01-01

    Computer program predicts boiling (phase change) in liquid face seals. Program determines if and when boiling occurs, and calculates location of boiling interface, pressure and temperature profiles, and load.

  10. Supported ionic liquid-phase (SILP) catalysis

    DEFF Research Database (Denmark)

    Riisager, Anders; Fehrmann, Rasmus; Wasserscheid, P.; van Hal, R.

    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...... performance, i.e. activity and selectivity, as well as stability of the SILP catalysts. Noticeably, a high catalyst ligand content together with presence of ionic liquid solvent are prerequisites for obtaining selective rhodium phosphine SILP catalysts systems....

  11. 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.

  12. Binary Solid-Liquid Phase Equilibria

    Science.gov (United States)

    Ellison, Herbert R.

    1978-01-01

    Indicates some of the information that may be obtained from a binary solid-liquid phase equilibria experiment and a method to write a computer program that will plot an ideal phase diagram to which the experimental results may be compared. (Author/CP)

  13. A Voltammetric Determination of the Rate Constant of a One-Way Homogeneous Chemical Reaction in a System of Two Immiscible Liquid Phases

    Czech Academy of Sciences Publication Activity Database

    Holub, Karel; Brusová, Zuzana; Štulík, K.; Mareček, Vladimír

    2004-01-01

    Roč. 574, č. 1 (2004), s. 101-106. ISSN 0022-0728 R&D Projects: GA ČR GA203/03/0822 Institutional research plan: CEZ:AV0Z4040901 Keywords : liquid|liquid interfaces * homogeneous reaction * voltammetry Subject RIV: CG - Electrochemistry Impact factor: 2.228, year: 2004

  14. The Instanton-Dyon Liquid Model III: Finite Chemical Potential

    CERN Document Server

    Liu, Yizhuang; Zahed, Ismail

    2016-01-01

    We discuss an extension of the instanton-dyon liquid model that includes light quarks at finite chemical potential in the center symmetric phase. We develop the model in details for the case of SU_c(2)\\times SU_f(2) by mapping the theory on a 3-dimensional quantum effective theory. We analyze the different phases in the mean-field approximation. We extend this analysis to the general case of SU_c(N_c)\\times SU_f(N_f) and note that the chiral and diquark pairings are always comparable.

  15. 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.

  16. Phase separation in transparent liquid-liquid miscibility gap systems

    International Nuclear Information System (INIS)

    A program to be carried out on transparent liquid-phase miscibility gap materials was developed for the purpose of acquiring additional insight into the separation process occurring in these systems. The transparency feature allows the reaction to be viewed directly through light scattering and holographic methods

  17. Phase separation in transparent liquid-liquid miscibility gap systems

    Science.gov (United States)

    Gelles, S. H.; Bhat, B. N.; Laub, R. J.

    1979-01-01

    A program to be carried out on transparent liquid-phase miscibility gap materials was developed for the purpose of acquiring additional insight into the separation process occurring in these systems. The transparency feature allows the reaction to be viewed directly through light scattering and holographic methods.

  18. 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

    -water-gas hydrate inhibitor systems, at temperatures ranging from 283 to 353 K and at pressures up to 40 MPa. The core of the equipment is an equilibrium cell, equipped with sapphire windows and connected to an analytical system by capillary samplers.New vapor-liquid-liquid equilibrium data are reported for methane...... optimization is dependent on phase equilibrium data.The objective of this work is to provide experimental data for hydrocarbon systems with polar chemicals such as alcohols, glycols and water. A new experimental equipment was designed and constructed for measurement of multi-phase equilibrium in hydrocarbon...

  19. Phase separation kinetics in immiscible liquids

    Science.gov (United States)

    Ng, Lee H.; Sadoway, Donald R.

    1987-01-01

    The kinetics of phase separation in the succinonitrile-water system are being investigated. Experiments involve initial physical mixing of the two immiscible liquids at a temperature above the consolute, decreasing the temperature into the miscibility gap, followed by iamging of the resultant microstructure as it evolves with time. Refractive index differences allow documentation of the changing microstructures by noninvasive optical techniques without the need to quench the liquid structures for analysis.

  20. Rapid Chemical Ordering in Supercooled Liquid Cu46Zr54

    Energy Technology Data Exchange (ETDEWEB)

    Wessels, Victor [ETH Zurich, Switzerland; Gangopadhyay, Anup [Washington University, St. Louis; Sahu, K. K. [Washington University, St. Louis; Hyers, R. W. [University of Massachusetts, Amherst; Canepari, S. M. [University of Massachusetts, Amherst; Rogers, J. R. [NASA Marshall Space Flight Center, Huntsville, AL; Kramer, Matthew J. [Ames Laboratory; Goldman, Alan [Ames Laboratory and Iowa State University; Robinson, D. [Ames Laboratory and Iowa State University; Lee, Jae W [ORNL; Morris, James R [ORNL; Kelton, K. F. [Washington University, St. Louis

    2011-01-01

    Evidence for abrupt chemical ordering in a supercooled Cu46Zr54 liquid, obtained from high energy x-ray diffraction in a containerless processing environment, is presented. Relatively sudden changes were observed in the topological and chemical short-range order near 850oC, a temperature significantly below the liquidus and above the glass transition temperatures. A peak in the specific heat was observed with supercooling, with an onset near 850oC, the same temperature as the onset of chemical ordering, and a maximum near 700oC, consistent with the prediction of a molecular dynamics calculation using embedded atom potentials. The dominant short-range order below 850oC is incompatible with that of the primary crystallizing phases. This, and the possible development of strongly bonded, chemically ordered clustersmay explain unlikely bulk metallic glass formation in Cu-Zr and other binary alloys.

  1. Identification of chemical compounds in a liquid-liquid extraction system

    International Nuclear Information System (INIS)

    The objective of the present work is to identify the chemical compounds that are distributed in a liquid-liquid extraction system in which the third phase is observed; for this purpose the FeCl3 (0.12M) - HCl (8.43M) - Diisopropilic ether - system was used, for the quantitative determination of the chemical compounds, FeCl3 solutions labelled with 59Fe or witH 38Cl were used; the Karl Fischer method for the determination of the water concentration at the organic phases was used, the obtained data was used for the calculations of the H+ distribution in each phase. The results are that when the distribution equilibrium is reached, the aqueous phase is a 7.5M HCl solution; the light organic phase contains 2 H[FeCl4].6H2O and the dense organic phase contains 2 H[FeCl4].6H2O.3HCl.12H2O. The differences between these compounds are due to a high concentration of water and the HCl in the organic solvent. This causes a heterogeneous physic field, and then the third phase formation. (author)

  2. Quasi-chemical Theories of Associated Liquids

    CERN Document Server

    Pratt, L R; Pratt, Lawrence R.; Violette, Randall A. La

    1998-01-01

    It is shown how traditional development of theories of fluids based upon the concept of physical clustering can be adapted to an alternative local clustering definition. The alternative definition can preserve a detailed valence description of the interactions between a solution species and its near-neighbors, i.e., cooperativity and saturation of coordination for strong association. These clusters remain finite even for condensed phases. The simplest theory to which these developments lead is analogous to quasi-chemical theories of cooperative phenomena. The present quasi-chemical theories require additional consideration of packing issues because they don't impose lattice discretizations on the continuous problem. These quasi-chemical theories do not require pair decomposable interaction potential energy models. Since calculations may be required only for moderately sized clusters, we suggest that these quasi-chemical theories could be implemented with computational tools of current electronic structure the...

  3. Quantum concentration for the liquid phase of elements

    Energy Technology Data Exchange (ETDEWEB)

    Kassymov, Askar [University of Texas at Brownsville, Department of Physics and Astronomy, Brownsville, TX 78520 (United States); Kazakh National Technical University after K.I. Satpaev, Almaty, 050013 (Kazakhstan); Schaumburg, Hanno [Hamburg University of Technology, Hamburg, 21073 (Germany); Kumekov, Serik E. [Kazakh National Technical University after K.I. Satpaev, Almaty, 050013 (Kazakhstan); Martirosyan, Karen S., E-mail: karen.martirosyan@utb.edu [University of Texas at Brownsville, Department of Physics and Astronomy, Brownsville, TX 78520 (United States)

    2015-07-01

    The novel concept of quantum concentration for the liquid phase of elements was introduced which indicates the number of possible states of atoms per unit volume. A simplified thermodynamic energy model for a solid–liquid phase transition is used to define the quantum concentration for the liquids. Values of quantum concentration for liquid phase of most of elements were calculated and analyzed. It was revealed that the metalloids such as boron, silicon, germanium, antimony, tellurium and bismuth exhibited a highest value of quantum concentrations compared with other elements. Several physical and chemical properties of substances (such as melting temperature and free energy) can be calculated using these data. The size dependence of melting temperatures of Au, Pb and Sn spherically symmetric nanoparticles were calculated and compared well with experimental data and theoretical model based on generalized Gibbs–Thomson predictions. - Highlights: • The novel concept of quantum concentration (QC) for the liquid phase was presented. • Metalloids exhibited a highest value of QC compared with other elements. • The size dependence of melting temperatures of metals was calculated by using QC.

  4. Quantum concentration for the liquid phase of elements

    International Nuclear Information System (INIS)

    The novel concept of quantum concentration for the liquid phase of elements was introduced which indicates the number of possible states of atoms per unit volume. A simplified thermodynamic energy model for a solid–liquid phase transition is used to define the quantum concentration for the liquids. Values of quantum concentration for liquid phase of most of elements were calculated and analyzed. It was revealed that the metalloids such as boron, silicon, germanium, antimony, tellurium and bismuth exhibited a highest value of quantum concentrations compared with other elements. Several physical and chemical properties of substances (such as melting temperature and free energy) can be calculated using these data. The size dependence of melting temperatures of Au, Pb and Sn spherically symmetric nanoparticles were calculated and compared well with experimental data and theoretical model based on generalized Gibbs–Thomson predictions. - Highlights: • The novel concept of quantum concentration (QC) for the liquid phase was presented. • Metalloids exhibited a highest value of QC compared with other elements. • The size dependence of melting temperatures of metals was calculated by using QC

  5. On the phase-field modelling of a miscible liquid/liquid boundary.

    Science.gov (United States)

    Xie, Ruilin; Vorobev, Anatoliy

    2016-02-15

    Mixing of miscible liquids is essential for numerous processes in industry and nature. Mixing, i.e. interpenetration of molecules through the liquid/liquid boundary, occurs via interfacial diffusion. Mixing can also involve externally or internally driven hydrodynamic flows, and can lead to deformation or disintegration of the liquid/liquid boundary. At the moment, the mixing dynamics remains poorly understood. The classical Fick's law, generally accepted for description of the diffusion process, does not explain the experimental observations, in particular, the recent experiments with dissolution of a liquid solute by a liquid solvent within a horizontal capillary (Stevar and Vorobev, 2012). We present the results of the numerical study aimed at development of an advanced model for the dissolution dynamics of liquid/liquid binary mixtures. The model is based on the phase-field (Cahn-Hilliard) approach that is used as a physics-based model for the thermo- and hydrodynamic evolution of binary mixtures. Within this approach, the diffusion flux is defined through the gradient of chemical potential, and, in particular, includes the effect of barodiffusion. The dynamic interfacial stresses at the miscible interface are also taken into account. The simulations showed that such an approach can accurately reproduce the shape of the solute/solvent boundary, and some aspects of the diffusion dynamics. Nevertheless, all experimentally-observed features of the diffusion motion of the solute/solvent boundary, were not reproduced. PMID:26609922

  6. 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...

  7. Centrifugal Liquid/Gas Separator With Phase Detectors

    Science.gov (United States)

    Schneider, Steven J.

    1994-01-01

    Centrifugal liquid/gas separator that includes phase (liquid or gas) detectors helps ensure exclusiveness of each phase at its assigned outlet. Acoustic sensors in centrifugal liquid/gas separator measure speeds of sound in nominally pure liquid and nominally pure gas at liquid and gas outlets respectively. When speed of sound is that of pure liquid or gas, valve opens to let liquid or gas flow out.

  8. Influence of Wetting and Mass Transfer Properties of Organic Chemical Mixtures in Vadose Zone Materials on Groundwater Contamination by Nonaqueous Phase Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Charles J Werth; Albert J Valocchi, Hongkyu Yoon

    2011-05-21

    Previous studies have found that organic acids, organic bases, and detergent-like chemicals change surface wettability. The wastewater and NAPL mixtures discharged at the Hanford site contain such chemicals, and their proportions likely change over time due to reaction-facilitated aging. The specific objectives of this work were to (1) determine the effect of organic chemical mixtures on surface wettability, (2) determine the effect of organic chemical mixtures on CCl4 volatilization rates from NAPL, and (3) accurately determine the migration, entrapment, and volatilization of organic chemical mixtures. Five tasks were proposed to achieve the project objectives. These are to (1) prepare representative batches of fresh and aged NAPL-wastewater mixtures, (2) to measure interfacial tension, contact angle, and capillary pressure-saturation profiles for the same mixtures, (3) to measure interphase mass transfer rates for the same mixtures using micromodels, (4) to measure multiphase flow and interphase mass transfer in large flow cell experiments, all using the same mixtures, and (5) to modify the multiphase flow simulator STOMP in order to account for updated P-S and interphase mass transfer relationships, and to simulate the impact of CCl4 in the vadose zone on groundwater contamination. Results and findings from these tasks and summarized in the attached final report.

  9. Solid drop based liquid-phase microextraction.

    Science.gov (United States)

    Ganjali, Mohammad Reza; Sobhi, Hamid Reza; Farahani, Hadi; Norouzi, Parviz; Dinarvand, Rassoul; Kashtiaray, Amir

    2010-04-16

    Solid drop based liquid-phase microextraction (SDLPME) is a novel sample preparation technique possessing obvious advantages of simple operation with a high pre-concentration factor, low cost and low consumption of organic solvent. SDLPME coupled with gas chromatography (GC), high-performance liquid chromatography (HPLC), and atomic absorption spectrometry (AAS) has been widely applied to the analyses of a different variety of samples. The basic principles, parameters affecting the extraction efficiency, and the latest applications of SDLPME are reviewed in this article. PMID:19962710

  10. 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

  11. Production of biofuels and chemicals with ionic liquids

    CERN Document Server

    Fang, Zhen; Qi, Xinhua

    2013-01-01

    This book explores the application of ionic liquids to biomass for producing biofuels and chemicals. Covers pretreatment, fermentation, cellulose transformation, reaction kinetics and more, as well as subsequent production of biofuels and platform chemicals.

  12. LIQUID PHASE FLOW ESTIMATION IN GAS-LIQUID TWO-PHASE FLOW USING INVERSE ANALYSIS AND PARTICLE TRACKING VELOCIMETRY

    Institute of Scientific and Technical Information of China (English)

    CHENG Wen; MURAI Yuichi; SASAKI Toshio; YAMAMOTO Fujio

    2004-01-01

    An inverse analysis algorithm is proposed for estimating liquid phase flow field from measurement data of bubble motion. This kind of technology will be applied in future for various estimation of fluid flow in rivers, lakes, sea surface flow, and also microscopic channel flow as the problem-handling in civil, mechanical, electronic, and chemical engineering. The relationship between the dispersion motion and the carrier phase flow is governed and expressed by the translational motion equation of spherical dispersion. The equation consists of all the force components including inertia, added inertia, drag, lift, pressure gradient force and gravity force. Using this equation enables us to estimate the carrier phase flow structure using only the data of the dispersion motion. Whole field liquid flow structure is also estimated using spatial or temporal interpolation method. In order to verify this principle, the Taylor-Green vortex flow, and the Karman vortex shedding from a square cylinder have been chosen. The results show that the combination of the inverse analysis and Particle Tracking Velocimetry (PTV) with the spatio-temporal post-processing algorithm could reconstruct well the carrier phase flow of the gas-liquid two-phase flow.

  13. Chemical treatment of radioactive liquid wastes from medical applications

    International Nuclear Information System (INIS)

    This work is a study about the treatment of the most important radioactive liquid wastes from medical usages, generated in medical institutions with nuclear medicine services. The radionuclides take in account are 32 P, 35 S, 125 I. The treatments developed and improved were specific chemical precipitations for each one of the radionuclides. This work involve to precipitate the radionuclide from the liquid waste, making a chemical compound insoluble in the aqueous phase, for this process the radionuclide stay in the precipitate, lifting the aqueous phase with a very low activity than the begin. The 32 P precipitated in form of Ca332 P O4 and Ca2 H 32 P O4 with a value for Decontamination Factor (DF) at the end of the treatment of 32. The 35 S was precipitated in form of Ba35 SO4 with a DF of 26. The 125 I was precipitated in Cu 125 I to obtain a DF of 24. The results of the treatments are between the limits given for the International Atomic Energy Agency and the 10 Code of Federal Regulation 20, for the safety release at the environment. (Author)

  14. 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.

  15. Advanced gas-to-liquids processes for syngas and liquid-phase conversion

    Energy Technology Data Exchange (ETDEWEB)

    Foster, E.P.; Tijm, P.J.A.; Bennett, D.L. [Air Products and Chemicals, Inc., Allentown (United States)

    1998-12-31

    Conventional technology options may lead to commercially viable gas-to-liquids (GTL) projects which are very large, have favorable site specific factors or very low natural gas costs. New and lower cost technology will be required to enable GTL, to be broadly useful for remote gas monetization as a liquid fuel. Air Products and Chemicals, Inc. is currently developing two separate technologies which would result in a significant reduction in the capital investment required for GTL, product plants. ITM Syngas is one of Air Products proprietary syngas technologies. It is in the early stages of development, but has the potential for very significant reductions in the cost of syngas, an important intermediate for GTL production. Air Products, along with its partners, have recently been selected by the U.S. Department of Energy (DOE) for an $85MM, three phase program to develop this ITM Syngas technology. The program will take eight years and culminate in a 15,000,000 SCFD pre-commercial syngas demonstration plant. In addition to ITM Syngas, in April 1997 Air Products started up a commercial scale Liquid Phase Methanol (LPMEOH) plant which converts coal derived syngas to methanol using a slurry bubble column reactor. This technology is expected to reduce the cost of liquid synthesis. It also produces an environmentally superior alternative fuel and/or chemical feedstocks. 7 refs.

  16. Caloric curve for nuclear liquid-gas phase transition in relativistic mean-field hadronic model

    CERN Document Server

    Parvan, A S

    2011-01-01

    The main thermodynamical properties of the nuclear liquid-gas phase transition were explored in the framework of the relativistic mean-field hadronic model in three statistical ensembles: canonical, grand canonical and isobaric. We have found that the liquid-gas phase transition, i.e., the first order phase transition which is defined by the plateau in the isotherms, cannot contain the plateau in the caloric curves in the canonical and microcanonical ensembles. The plateau in the isotherms is incompatible with the plateau in the caloric curves at fixed baryon density. Moreover, for the nuclear liquid-gas phase transition the caloric curve has a plateau only at fixed pressure or chemical potential. The results of the statistical multifragmentation models for the nuclear liquid-gas phase transition were reanalyzed. It was revealed that one class of statistical multifragmentation models do indeed predict the nuclear liquid-gas phase transition for the nuclear multifragmentation. However, there is another class o...

  17. Liquid-Liquid-Liquid Three Phase Extraction Apparatus: Operation Strategy and Influences on Mass Transfer Efficiency

    Institute of Scientific and Technical Information of China (English)

    何秀琼; 黄昆; 于品华; 张超; 谢铿; 李鹏飞; 王娟; 安震涛; 刘会洲

    2012-01-01

    Abstract A new mixer-settler-mixer three chamber integrated extractor is proposed in this work for liquid-liquid- liquid three phase countercurrent and continuous extraction. Experiments revealed the influences of the structural design of the three-liquid-phase extractor and some key operational parameters on three-phase partition of two phenolic isomers, p-nitrophenol (p-NP) and o-nitrophenol (o-NP). The model three-liquid-phase extraction system used here is nonane (organic top-plaase)-polyethylene glycol (PEG 20UU) (polymer mlddle-phase)-(NH4)2SO4 aqueous solution (aqueous bottom-phase). It is indicated that agitating speed and retention time in three-phase mixer are key parameters to extraction fraction of nitrophenol. Dispersion band behavior is related to agitating intensity, and its occurrence does not affect the extraction fraction of target compounds. The present work highlights the possibility of a feasible approach of scaling up of the proposed three-phase extraction apparatus for future in- dustrial-aimed applications.

  18. Part-per-trillion level determination of antifouling pesticides and their byproducts in seawater samples by off-line solid-phase extraction followed by high-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry.

    Science.gov (United States)

    Martínez, K; Ferrer, I; Barceló, D

    2000-05-19

    A new method for the simultaneous determination of antifouling pesticides and some of their byproducts such as dichlofluanid, diuron and its byproducts [demethyldiuron and 1-(3,4-dichlorophenyl)urea], (2-thiocyanomethylthio)ben: zothiazole, chlorothalonil, Sea-nine 211, Irgarol 1051 and one of its byproducts (2-methylthio-4-tert.-butylamino-s-triazine) in seawater was developed. The extraction of these compounds from the filtered seawater samples was performed off-line with different solid-phase extraction sorbents using (I) a 500 mg graphitized carbon black cartridge (ENVI-Carb) and (II) 200 mg polymeric cartridges (LiChrolut EN and Isolute ENV+) and passing 500 ml of the sample through these cartridges. The detection was carried out by reversed-phase high-performance liquid chromatography coupled with atmospheric pressure chemical ionization mass spectrometry both in the negative and positive ion modes. The recovery ranged from 76 to 96% for the whole antifouling group with the ENVI-Carb cartridges and the detection limit was at the part-per-trillion level except for TCMTB. The method utilizing the polymeric cartridge proved to be very useful, time saving and with good recoveries when only Irgarol and its byproduct, Sea-nine 211 and diuron and its byproducts, have to be analyzed. The different cartridges were applied to the analysis of these pesticides in different marinas of the Catalan coast; diuron, dichlofluanid, Sea-nine 211, Irgarol as well as demethyldiuron and the Irgarol byproduct being the must ubiquitous pollutants. Maximum concentration levels were 2-3.5 microg/l of diuron and Sea-nine 211, respectively. PMID:10870693

  19. Investigating materials formation with liquid-phase and cryogenic TEM

    Science.gov (United States)

    de Yoreo, J. J.; N. A. J. M., Sommerdijk

    2016-08-01

    The recent advent of liquid-phase transmission electron microscopy (TEM) and advances in cryogenic TEM are transforming our understanding of the physical and chemical mechanisms underlying the formation of materials in synthetic, biological and geochemical systems. These techniques have been applied to study the dynamic processes of nucleation, self-assembly, crystal growth and coarsening for metallic and semiconductor nanoparticles, (bio)minerals, electrochemical systems, macromolecular complexes, and organic and inorganic self-assembling systems. New instrumentation and methodologies that are currently on the horizon promise new opportunities for advancing the science of materials synthesis.

  20. Distribution of Pb and its chemical fractions in liquid and solid phases of digested pig and dairy slurries%猪、奶牛粪厌氧发酵中Pb的形态转化及其分布特征

    Institute of Scientific and Technical Information of China (English)

    靳红梅; 付广青; 常志州; 叶小梅

    2013-01-01

    Anaerobic digestion treatment effectively degrades the organic matter and causes obvious variations in physical and chemical properties of digested slurries, such as water content, pH, oxidation reduction potential and microbial activities. These changes may influence the chemical fraction of Pb, which is a critical factor in predicting its toxicity, environmental mobility, bioavailability and optimum removal methods. The speciation and phytotoxic effects of lead from sewage sludge and composted manure have been widely studied. There has been no study about the transfer and distribution of Pb during anaerobic digestion of manure slurries. The aim of the present work was to analyze the distribution of Pb in both liquid and solid phase after anaerobic digestion of pig slurries and dairy slurries, and their chemical speciation in solid fraction of digested residuals. The continuous stirred tank reactor (CSTR) at condition of medium temperature [(37 ± 2)℃] was operated for 130 d. Lead in liquid and solid phases of raw materials and digested slurries was analyzed by first passing through a 0.45 µm filter paper. The chemical fractions in digested slurry solids were extracted by BCR method. Results showed that total amount of Pb was decreased 70% and 19% in digested pig slurries (DPS) and dairy slurries (DDS), respectively, , compared with raw slurries. The percentages of Pb in liquid fractions of DPS and DDS were 29%and 17%, which decreased by 17%and 58%. The decrease of Pb in DDS was significantly lower than that in DPS. One reason is that 90%of solids in DDS were discharged during the anaerobic digestion. Another reason is that Pb in digested slurries mainly exists as the solid form. Thus the amount of Pb left in the reactor for dairy manure digestion was significantly lower than that for pig manure digest. Due to the high removal efficiency, easy operation and low treatment cost of heavy metals in solid phase, transformation of liquid phase of heavy metals to the

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

    International Nuclear Information System (INIS)

    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)

  2. Receptors useful for gas phase chemical sensing

    Energy Technology Data Exchange (ETDEWEB)

    Jaworski, Justyn W; Lee, Seung-Wuk; Majumdar, Arunava; Raorane, Digvijay A

    2015-02-17

    The invention provides for a receptor, capable of binding to a target molecule, linked to a hygroscopic polymer or hydrogel; and the use of this receptor in a device for detecting the target molecule in a gaseous and/or liquid phase. The invention also provides for a method for detecting the presence of a target molecule in the gas phase using the device. In particular, the receptor can be a peptide capable of binding a 2,4,6-trinitrotoluene (TNT) or 2,4,-dinitrotoluene (DNT).

  3. 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.

  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. Replication Experiments in Microgravity Liquid Phase Sintering

    Science.gov (United States)

    German, Randall M.; Johnson, John L.

    2016-05-01

    Although considerable experience exists with sintering on Earth, the behavior under reduced gravity conditions is poorly understood. This study analyzes replica microgravity liquid phase sintering data for seven tungsten alloys (35 to 88 wt pct tungsten) sintered for three hold times (1, 180, or 600 minutes) at 1773 K (1500 °C) using 0.002 pct of standard gravity. Equivalent sintering is performed on Earth using the same heating cycles. Microgravity sintering results in a lower density and more shape distortion. For Earth-based sintering, minimized distortion is associated with low liquid contents to avoid solid settling and slumping. Distortion in microgravity sintering involves viscous spreading of the component at points of contact with the containment crucible. Distortion in microgravity is minimized by short hold times; long hold times allow progressive component reshaping toward a spherical shape. Microgravity sintering also exhibits pore coalescence into large, stable voids that cause component swelling. The microgravity sintering results show good replication in terms of mass change and sintered density. Distortion is scattered but statistically similar between the replica microgravity runs. However, subtle factors, not typically of concern on Earth, emerge to influence microgravity sintering, such that ground experiments do not provide a basis to predict microgravity behavior.

  6. Dynamics of transient metastable states in mixtures under coupled phase ordering and chemical demixing

    OpenAIRE

    Soulé, Ezequiel R.; Rey, Alejandro D.

    2013-01-01

    We present theory and simulation of simultaneous chemical demixing and phase ordering in a polymer-liquid crystal mixture in conditions where isotropic-isotropic phase separation is metastable with respect to isotropic-nematic phase transition. In the case the mechanism is nucleation and growth, it is found that mesophase growth proceeds by a transient metastable phase that surround the ordered phase, and whose lifetime is a function of the ratio of diffusional to orientational mobilities. In...

  7. Ab-initio chemical potentials of solid and liquid solutions and the chemistry of the Earth's core

    OpenAIRE

    Alfe, D.; Gillan, M. J.; Price, G. D.

    2001-01-01

    A general set of methods is presented for calculating chemical potentials in solid and liquid mixtures using {\\em ab initio} techniques based on density functional theory (DFT). The methods are designed to give an {\\em ab initio} approach to treating chemical equilibrium between coexisting solid and liquid solutions, and particularly the partitioning ratio of solutes between such solutions. For the liquid phase, the methods are based on the general technique of thermodynamic integration, appl...

  8. Can ionic liquids avoid third phase formation in solvent extraction?

    International Nuclear Information System (INIS)

    The undesirable third phase is generally encountered in molecular diluent systems at high metal loading concentrations. Since the ionic liquids comprise entirely of ions, the use of an ionic liquid as diluent could stabilize the polar metal-solvate in organic phase and thus could prevent the third phase formation. To confirm this the extraction behavior of Eu(III) from nitric acid medium was studied in a solution of tetra-N,N,N',N'-octyldiglycolamide (TODGA) dissolved in the ionic liquid, 1-methyl-3-octylimidazolium bis(trifluoromethansulfonyl)imide ((C8mim)(NTf2)). Our results confirmed that ionic liquids prevent undesirable third phase formation. (author)

  9. Liquid plasmonics: manipulating surface plasmon polaritons via phase transitions.

    Science.gov (United States)

    Vivekchand, S R C; Engel, Clifford J; Lubin, Steven M; Blaber, Martin G; Zhou, Wei; Suh, Jae Yong; Schatz, George C; Odom, Teri W

    2012-08-01

    This paper reports the manipulation of surface plasmon polaritons (SPPs) in a liquid plasmonic metal by changing its physical phase. Dynamic properties were controlled by solid-to-liquid phase transitions in 1D Ga gratings that were fabricated using a simple molding process. Solid and liquid phases were found to exhibit different plasmonic properties, where light coupled to SPPs more efficiently in the liquid phase. We exploited the supercooling characteristics of Ga to access plasmonic properties associated with the liquid phase over a wider temperature range (up to 30 °C below the melting point of bulk Ga). Ab initio density functional theory-molecular dynamic calculations showed that the broadening of the solid-state electronic band structure was responsible for the superior plasmonic properties of the liquid metal. PMID:22823536

  10. Aqueous phase chemical properties of transactinides

    International Nuclear Information System (INIS)

    65-s 261Rf and 34-s 262Ha have been produced at the Lawrence Berkeley Laboratory 88-Inch Cyclotron by the 248Cm(18O,5n) and 249Bk(18O,5n) reactions, respectively. These isotopes of element 104 and 105 are produced at a one atom per minute rate, and rapid chemical separations are performed on a one-minute time scale. They are identified by detecting the α- and SF radiations from their decay. First aqueous phase chemical separations of Rf and Ha determined their primary oxidation states in aqueous solution, placing them in the periodic table at the bottom of groups 4 and 5, respectively, and confirming Seaborg's actinide concept. More recently, experiments measuring the chemical properties in more detail have uncovered some interesting and unexpected trends in periodic table properties

  11. Coal-Face Fracture With A Two-Phase Liquid

    Science.gov (United States)

    Collins, E. R., Jr.

    1985-01-01

    In new method for mining coal without explosive, two-phase liquid such as CO2 and water, injected at high pressure into deeper ends of holes drilled in coal face. Liquid permeates coal seam through existing microfractures; as liquid seeps back toward face, pressure eventually drops below critical value at which dissolved gas flashvaporizes, breaking up coal.

  12. Calculation of Liquid Water-Hydrate-Methane Vapor Phase Equilibria from Molecular Simulations

    DEFF Research Database (Denmark)

    Jensen, Lars; Thomsen, Kaj; von Solms, Nicolas;

    2010-01-01

    Monte Carlo simulation methods for determining fluid- and crystal-phase chemical potentials are used for the first time to calculate liquid water-methane hydrate-methane vapor phase equilibria from knowledge of atomistic interaction potentials alone. The water and methane molecules are modeled...... using the TIP4P/ice potential and a united-atom Lennard-Jones potential. respectively. The equilibrium calculation method for this system has three components, (i) thermodynamic integration from a supercritical ideal gas to obtain the fluid-phase chemical potentials. (ii) calculation of the chemical...

  13. Simulation of phase separation in quiescent and sheared liquids

    NARCIS (Netherlands)

    Thakre, Amol Kumar

    2008-01-01

    In this thesis we report on molecular dynamics simulations of phase separation of simple and complex binary liquids in sheared and non-sheared systems. The separation of milk into liquid whey and solid curd is a very common example of phase separation observed in daily life. The phenomenon finds its

  14. Recent Developments in Chemical Synthesis with Biocatalysts in Ionic Liquids

    OpenAIRE

    Mahesh K. Potdar; Geoffrey F. Kelso; Lachlan Schwarz; Chunfang Zhang; Milton T. W. Hearn

    2015-01-01

    Over the past decade, a variety of ionic liquids have emerged as greener solvents for use in the chemical manufacturing industries. Their unique properties have attracted the interest of chemists worldwide to employ them as replacement for conventional solvents in a diverse range of chemical transformations including biotransformations. Biocatalysts are often regarded as green catalysts compared to conventional chemical catalysts in organic synthesis owing to their properties of low toxicity,...

  15. Evidence for liquid phase reactions during single bubble acoustic cavitation.

    Science.gov (United States)

    Troia, A; Madonna Ripa, D; Lago, S; Spagnolo, R

    2004-07-01

    We extended the recent experiment by Lepoint et al. [Sonochemistry and Sonoluminescence, NATO ASI Series, Series C 524, Kluwer Academic Publishers, Dordrecht/Boston/London, 1999, p. 285], involving a so-called single bubble sonochemistry process, to a three-phase system. We have found experimental evidence that a single cavitating bubble can activate the oxidation of I- ions after the injection of a CCl4 liquid drop in the bubble trapping apparatus. The solvent drop (CCl4 is almost water insoluble) is pushed towards the bubble position and forms a thin film on the bubble surface. When the acoustic pressure drive is increased above 100 kPa, the three-phase system gives rise to a dark filament, indicating the complexation reaction between starch (added to the water phase) and I2. I2 species is the product of surface reactions involving bubble-induced decomposition of CCl4. Further increase of the acoustic drive causes the thin CCl4 film to separate from the bubble and stops I2 production. The study of the chemical activity of this three-phase system could give new advances on dynamics of the bubble collapse. PMID:15157862

  16. Effect of counter current gas phase on liquid film

    Institute of Scientific and Technical Information of China (English)

    Shujuan LUO; Huaizhi LI; Weiyang FEI; Yundong WANG

    2009-01-01

    Liquid film flow is very important in many industrial applications. However, there are few reports about its characteristics on structured packings. Therefore, in this paper, liquid film phenomena were investigated experimentally to exploit new approaches for intensifying the performance of the structured packings. All experiments were performed at room temperature. Water and air were the working fluids. The effect of counter current gas phase on the liquid film was taken into consideration. A high speed camera, a non-intrusive measurement technique, was used. It is shown that both liquid and gas phases have strong effects on film characteristics. In the present work, liquid film width increased by 57% because of increasing liquid flow rate, while it decreased by 25% resulting from the counter current gas phase.

  17. Blending ionic liquids: how physico-chemical properties change.

    Science.gov (United States)

    Castiglione, Franca; Raos, Guido; Appetecchi, Giovanni Battista; Montanino, Maria; Passerini, Stefano; Moreno, Margherita; Famulari, Antonino; Mele, Andrea

    2010-02-28

    Ionic liquids offer the opportunity of tailoring their properties by changing the chemical structure of the cation and anion. Blending of two or more liquids adds a further dimension to this "chemical space". Here we present the results of a study of three binary and one ternary mixture of the ionic liquids formed by the N-butyl-N-methylpyrrolidinium cation with bis(trifluoromethanesulfonyl) imide, bis(pentafluoroethanesulfonyl) imide and (trifluoromethanesulfonyl)(nonafluorobutanesulfonyl) imide. We have collected viscosity and NMR-based data on ionxion correlations (NOE) and diffusion (DOSY). We also attempt to establish a quantitative correlation between mixture and the corresponding pure liquid properties. We find that the binary mixture containing the two very different anions has an intriguing and somewhat anomalous behaviour. PMID:20145843

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

    Science.gov (United States)

    Lima, Thamires A.; Paschoal, Vitor H.; Faria, Luiz F. O.; Ribeiro, Mauro C. C.; Giles, Carlos

    2016-06-01

    X-ray scattering experiments at room temperature were performed for the ionic liquids n-butyl-trimethylammonium bis(trifluoromethanesulfonyl)imide, [N1114][NTf2], and methyl-tributylammonium bis(trifluoromethanesulfonyl)imide, [N1444][NTf2]. The peak in the diffraction data characteristic of charge ordering in [N1444][NTf2] is shifted to longer distances in comparison to [N1114][NTf2], but the peak characteristic of short-range correlations is shifted in [N1444][NTf2] 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 [N1114]+ and [N1444]+ 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 [N1444]+ as to [N1114]+ because anions are located in between the angle formed by the butyl chains. The more asymmetric molecular structure of the [N1114]+ cation implies differences in partial structure factors calculated for atoms belonging to polar or non-polar parts of [N1114][NTf2], whereas polar and non-polar structure factors are essentially the same in [N1444][NTf2]. Results of this work shed light on controversies in the literature on the liquid structure of tetraalkylammonium based ionic liquids.

  19. Liquid-Phase Electroepitaxy of Semiconductors

    Science.gov (United States)

    Dost, Sadik

    The chapter presents a review of the growth of single-crystal bulk semiconductors by liquid-phase electroepitaxy (LPEE). Following a short introduction, early modeling and theoretical studies on LPEE are briefly introduced. Recent experimental results on LPEE growth of GaAs/GaInAs single crystals under a static applied magnetic field are discussed in detail. The results of three-dimensional numerical simulations carried out for LPEE growth of GaAs under various electric and magnetic field levels are presented. The effect of magnetic field nonuniformities is numerically examined. Crystal growth experiments show that the application of a static magnetic field in LPEE growth of GaAs increases the growth rate very significantly. A continuum model to predict such high growth rates is also presented. The introduction of a new electric mobility in the model, i.e., the electromagnetic mobility, allows accurate predictions of both the growth rate and the growth interface shape. Space limitation required the citation of a limited number of references related to LPEE [29.1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73]. For details of many aspects of the LPEE growth process and its historical developments, the reader is referred to these references and also others cited therein.

  20. Chemical behaviors of actinides and lanthanides in molten salts and liquid metals

    International Nuclear Information System (INIS)

    Separation processes using molten salts or liquid metals are interesting in view of spent fuel reprocessing and partitioning for nuclear transmutation before final radioactive waste disposals. Nevertheless, chemical behaviors of transuranium and lanthanide elements in non-aqueous solvents such as molten salts and liquid metals have been rarely studied. In the present study, thermodynamic properties of La, Ce, Pr, Nd, Gd, Tb, Ho, Er, Tm, Lu, Np, Pu, Am, and Cm in two phase extraction system: molten LiCl-KCl and liquid Bi or Zn were investigated to obtain excess Gibbs free energy experimentally or by using thermodynamic relationships and to examine systematics of 4f and 5f elements in these phases. Thermodynamic stability and specificity of each elements in liquid metals and salts thus obtained can be successfully used to explain systematics of extractability of f-elements in these systems. (Ohno, S.)

  1. In-Situ Chemical Precipitation of Radioactive Liquid Waste - 12492

    International Nuclear Information System (INIS)

    This paper presented in-situ chemical precipitation for radioactive liquid waste by using chemical agents. Results are reported on large-scale implementation on the removal of 137Cs, 134Cs and 60Co from liquid radioactive waste generating from Nuclear Research and Training Centre. Total amount of liquid radioactive waste was 35 m3 and main radionuclides were Cs-137, Cs- 134 and Co-60. Initial radioactivity concentration of the liquid waste was 2264, 17 and 9 Bq/liter for Cs-137, Cs-134 and Co-60 respectively. Potassium ferro cyanide was selected as chemical agent at high pH levels 8-10 according to laboratory tests. After the process, radioactive sludge precipitated at the bottom of the tank and decontaminated clean liquid was evaluated depending on discharge limits. By this precipitation method decontamination factors were determined as 60, 9 and 17 for Cs-137, Cs-134 and Co-60 respectively. At the bottom of the tank radioactive sludge amount was 0.98 m3. It was transferred by sludge pumps to cementation unit for solidification. By in situ chemical processing 97% of volume reduction was achieved. Using the optimal concentration of 0.75 M potassium ferro cyanide about 98% of the 137Cs can be removed at pH 8. The Potassium ferro cyanide precipitation method could be used successfully in large scale applications with nickel and ferrum agents for removal of Cs-137, Cs-134 and Co- 60. Although DF values of laboratory test were much higher than in-situ implementation, liquid radioactive waste was decontaminated successfully by using potassium ferro cyanide. Majority of liquid waste were discharged as clean liquid. %97.2 volumetric amount of liquid waste was cleaned and discharged at the original site. Reduced amount of sludge transportation in drums is more economical and safer method than liquid transportation. Although DF values could be different for each of applications related to main specifications of original liquid waste, this study shows that in-situ treatment

  2. Quasi-chemical Theories of Associated Liquids

    OpenAIRE

    Pratt, Lawrence R.; LaViolette, Randall A.

    1998-01-01

    It is shown how traditional development of theories of fluids based upon the concept of physical clustering can be adapted to an alternative local clustering definition. The alternative definition can preserve a detailed valence description of the interactions between a solution species and its near-neighbors, i.e., cooperativity and saturation of coordination for strong association. These clusters remain finite even for condensed phases. The simplest theory to which these developments lead i...

  3. Analysis of solid-liquid phase change heat transfer enhancement

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Yinping(张寅平); WANG; Xin(王馨)

    2002-01-01

    Solid-liquid phase change processes have two important features: the process is an approximately isothermal process and the heat of fusion of phase change material tends to be much greater than its specific heat. Therefore, if any phase change material adjacent to a hot or cold surface undergoes phase change, the heat transfer rate on the surface will be noticeably enhanced. This paper presents a novel insight into the mechanisms of heat transfer enhancement induced by solid-liquid phase change based on the analogy analysis for heat conduction with an internal heat source and solid-liquid phase change heat transfer. Three degrees of surface heat transfer enhancement for different conditions are explored, and corresponding formulae are written to describe them. The factors influencing the degrees of heat transfer enhancement are clarified and their effects quantitatively analyzed. Both the novel insight and the analysis contribute to effective application of phase change heat transfer enhancement technique.

  4. Transient-Liquid-Phase and Liquid-Film-Assisted Joining ofCeramics

    Energy Technology Data Exchange (ETDEWEB)

    Sugar, Joshua D.; McKeown, Joseph T.; Akashi, Takaya; Hong, SungM.; Nakashima, Kunihiko; Glaeser, Andreas M.

    2005-02-09

    Two joining methods, transient-liquid-phase (TLP) joining and liquid-film-assisted joining (LFAJ), have been used to bond alumina ceramics. Both methods rely on multilayer metallic interlayers designed to form thin liquid films at reduced temperatures. The liquid films either disappear by interdiffusion (TLP) or promote ceramic/metal interface formation and concurrent dewetting of the liquid film (LFAJ). Progress on extending the TLP method to lower temperatures by combining low-melting-point (<450 C) liquids and commercial reactive-metal brazes is described. Recent LFAJ work on joining alumina to niobium using copper films is presented.

  5. Liquid-Gas Phase Transition in Nuclear Equation of State

    CERN Document Server

    Lee, S J

    1997-01-01

    A canonical ensemble model is used to describe a caloric curve of nuclear liquid-gas phase transition. Allowing a discontinuity in the freeze out density from one spinodal density to another for a given initial temperature, the nuclear liquid-gas phase transition can be described as first order. Averaging over various freeze out densities of all the possible initial temperatures for a given total reaction energy, the first order characteristics of liquid-gas phase transition is smeared out to a smooth transition. Two experiments, one at low beam energy and one at high beam energy show different caloric behaviors and are discussed.

  6. Chemical and colour quenching in liquid scintillation counting

    International Nuclear Information System (INIS)

    Chemical and colour quenching for H-3 and C-14 was studied. The method includes spectral analysis of colouring agents; methyl red, (4'-dimethylamine-azobenzene 2-carboxylic acid) dimethyl yellow (4'-dimethylamine-azobenzene) and malachite green (methane, bis .(4-dimethyl aminophenyl) - (phenyl)). External standard channels ratio was applied for the liquid scintillation counting of samples. The introduction of an isolated external standard seems to be a strong tool for the correction of chemical and colour quenching curves. (Author) 12 refs

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

    International Nuclear Information System (INIS)

    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

  8. Liquid crystalline phases in concentrated aqueous solutions of Na+ DNA.

    OpenAIRE

    Rill, R L

    1986-01-01

    Concentrated aqueous saline solutions of short (146-base-pair) DNA fragments suddenly become turbid and iridescent when the DNA concentration is slightly increased or the temperature is decreased. Microscopic examination through crossed polarizing filters shows that turbidity and iridescence is due to formation of a liquid crystalline DNA phase similar to cholesteric liquid crystals formed by other semirigid, but nonelectrolyte, chiral polymers. Several distinct textures of the liquid crystal...

  9. Determination of Human-Health Pharmaceuticals in Filtered Water by Chemically Modified Styrene-Divinylbenzene Resin-Based Solid-Phase Extraction and High-Performance Liquid Chromatography/Mass Spectrometry

    Science.gov (United States)

    Furlong, Edward T.; Werner, Stephen L.; Anderson, Bruce D.; Cahill, Jeffery D.

    2008-01-01

    In 1999, the Methods Research and Development Program of the U.S. Geological Survey National Water Quality Laboratory began the process of developing a method designed to identify and quantify human-health pharmaceuticals in four filtered water-sample types: reagent water, ground water, surface water minimally affected by human contributions, and surface water that contains a substantial fraction of treated wastewater. Compounds derived from human pharmaceutical and personal-care product use, which enter the environment through wastewater discharge, are a newly emerging area of concern; this method was intended to fulfill the need for a highly sensitive and highly selective means to identify and quantify 14 commonly used human pharmaceuticals in filtered-water samples. The concentrations of 12 pharmaceuticals are reported without qualification; the concentrations of two pharmaceuticals are reported as estimates because long-term reagent-spike sample recoveries fall below acceptance criteria for reporting concentrations without qualification. The method uses a chemically modified styrene-divinylbenzene resin-based solid-phase extraction (SPE) cartridge for analyte isolation and concentration. For analyte detection and quantitation, an instrumental method was developed that used a high-performance liquid chromatography/mass spectrometry (HPLC/MS) system to separate the pharmaceuticals of interest from each other and coextracted material. Immediately following separation, the pharmaceuticals are ionized by electrospray ionization operated in the positive mode, and the positive ions produced are detected, identified, and quantified using a quadrupole mass spectrometer. In this method, 1-liter water samples are first filtered, either in the field or in the laboratory, using a 0.7-micrometer (um) nominal pore size glass-fiber filter to remove suspended solids. The filtered samples then are passed through cleaned and conditioned SPE cartridges at a rate of about 15

  10. Thermomorphic phase separation in ionic liquid-organic liquid systems - conductivity and spectroscopic characterization

    DEFF Research Database (Denmark)

    Riisager, Anders; Fehrmann, Rasmus; Berg, Rolf W.;

    2005-01-01

    Electrical conductivity, FT-Raman and NMR measurements are demonstrated as useful tools to probe and determine phase behavior of thermomorphic ionic liquid-organic liquid systems. To illustrate the methods, consecutive conductivity measurements of a thermomorphic methoxyethoxyethyl......-imidazolium ionic liquid/1-hexanol system are performed in the temperature interval 25-80 degrees C using a specially constructed double-electrode cell. In addition, FT-Raman and H-1-NMR spectroscopic studies performed on the phase-separable system in the same temperature interval confirm the mutual solubility of...... the components in the system, the liquid-liquid equilibrium phase diagram of the binary mixture, and signify the importance of hydrogen bonding between the ionic liquid and the hydroxyl group of the alcohol....

  11. Electron-solid and electron-liquid phases in graphene

    Science.gov (United States)

    Knoester, M. E.; Papić, Z.; Morais Smith, C.

    2016-04-01

    We investigate the competition between electron-solid and quantum-liquid phases in graphene, which arise in partially filled Landau levels. The differences in the wave function describing the electrons in the presence of a perpendicular magnetic field in graphene with respect to the conventional semiconductors, such as GaAs, can be captured in a form factor which carries the Landau-level index. This leads to a quantitative difference in the electron-solid and -liquid energies. For the lowest Landau level, there is no difference in the wave function of relativistic and nonrelativistic systems. We compute the cohesive energy of the solid phase analytically using a Hartree-Fock Hamiltonian. The liquid energies are computed analytically as well as numerically, using exact diagonalization. We find that the liquid phase dominates in the n =1 Landau level, whereas the Wigner crystal and electron-bubble phases become more prominent in the n =2 and 3 Landau level.

  12. Simulation of phase separation in quiescent and sheared liquids

    OpenAIRE

    Thakre, Amol Kumar

    2008-01-01

    In this thesis we report on molecular dynamics simulations of phase separation of simple and complex binary liquids in sheared and non-sheared systems. The separation of milk into liquid whey and solid curd is a very common example of phase separation observed in daily life. The phenomenon finds its application in various fields of science and technology, ranging from metals, semiconductors, superconductors to simple and complex fluids such as polymers, surfactants, colloids, emulsions and bi...

  13. Gas-Liquid Flows and Phase Separation

    Science.gov (United States)

    McQuillen, John

    2004-01-01

    Common issues for space system designers include:Ability to Verify Performance in Normal Gravity prior to Deployment; System Stability; Phase Accumulation & Shedding; Phase Separation; Flow Distribution through Tees & Manifolds Boiling Crisis; Heat Transfer Coefficient; and Pressure Drop.The report concludes:Guidance similar to "A design that operates in a single phase is less complex than a design that has two-phase flow" is not always true considering the amount of effort spent on pressurizing, subcooling and phase separators to ensure single phase operation. While there is still much to learn about two-phase flow in reduced gravity, we have a good start. Focus now needs to be directed more towards system level problems .

  14. Josephson Coupling, Phase Correlations, and Josephson Plasma Resonance in Vortex Liquid Phase

    OpenAIRE

    Koshelev, A. E.; Bulaevskii, L. N.; Maley, M. P.

    2000-01-01

    Josephson plasma resonance has been introduced recently as a powerful tool to probe interlayer Josephson coupling in different regions of the vortex phase diagram in layered superconductors. In the liquid phase, the high temperature expansion with respect to the Josephson coupling connects the Josephson plasma frequency with the phase correlation function. This function, in turn, is directly related to the pair distribution function of the liquid. We develop a recipe to extract the phase and ...

  15. 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)

    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

  16. 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.

  17. Liquid phase combustion of iron in an oxygen atmosphere

    OpenAIRE

    Muller, Maryse; El-Rabii, Hazem; FABBRO, Rémy

    2015-01-01

    In this article, we report an investigation of laser-initiated ignition of pure iron rods, using optical pyrometry, video observations, and analysis of metallographic cross section of quenched burning liquid on copper plates. When ignition occurs, caused by the melting of metal, the combustion takes place in the liquid. Two distinct superposed phases (L1 and L2) are identified in the liquid, according to the known phase diagram of the iron oxide system. Our observations show that the L1 and L...

  18. Relationship between the liquid-liquid phase transition and dynamic behaviour in the Jagla model

    International Nuclear Information System (INIS)

    Using molecular dynamics simulations, we study a spherically symmetric 'two-scale' Jagla potential with both repulsive and attractive ramps. This potential displays a liquid-liquid phase transition with a positively sloped coexistence line ending at a critical point well above the equilibrium melting line. We study the dynamic behaviour in the vicinity of this liquid-liquid critical point. Below the critical point, we find that the dynamics in the more ordered high density liquid (HDL) are much slower then the dynamics in the less ordered low density liquid (LDL). Moreover, the behaviour of the diffusion constant and relaxation time in the HDL phase follows approximately an Arrhenius law, while in the LDL phase the slope of the Arrhenius fit increases upon cooling. Above the critical pressure, as we cool the system at constant pressure, the behaviour of the dynamics smoothly changes with temperature. It resembles the behaviour of the LDL at high temperatures and resembles the behaviour of the HDL at low temperatures. This dynamic crossover happens in the vicinity of the Widom line (the extension of the coexistence line into the one-phase region) which also has a positive slope. Our work suggests a possible general relation between a liquid-liquid phase transition and the change in dynamics

  19. Liquid-phase alkylation of Assam (Baragolai) coal

    Energy Technology Data Exchange (ETDEWEB)

    Kalra, R.L.; Choudhury, R.; Sarkar, M.K.

    1982-12-01

    Liquid paraffin which consists of a large number of alkylated aliphatics and aromatics seems to be acting as an alkyl group transfer medium to receptive complexes like coal. The alkyl group receptive spots could be created in the coal complex by treatment with molten alkalis like sodium or potassium hydroxide. By repeating extractions of fresh coal with the same volume of liquid paraffin on a laboratory scale it was found that a stage was reached when liquid paraffin became rich enough in alkyl groups to become an alkyl group donor. This suggests a method for liquid phase alkylation of coal. (3 refs.)

  20. Progress in the research and development of p-xylene liquid phase oxidation process

    Institute of Scientific and Technical Information of China (English)

    WANG Lijun; CHENG Youwei; WANG Qinbo; LI Xi

    2007-01-01

    The process of p-xylene liquid phase oxidation to produce purified terephthalic acid (PTA) involves a series of liquid phase radical reactions,chemical absorption,reactive crystallization,and evaporation.A commercial PTA production flow sheet includes a number of unit operations,which construct a complex process system.In this paper,a review of research and development (R & D) works on PTA process carried out in Zhejiang University during recent years is introduced.The works cover the oxidation and crystallization kinetics,gas-liquid mass transfer and evaporation,reactor modeling,database development,novel reactor design,process modeling,simulation,and optimization.The author emphasizes the viewpoint through this case study that chemical reaction engineering should be developed to process system engineering to extend its scope,and particular attention should be paid on reactor and process modeling.

  1. Green aspects, developments and perspectives of liquid phase microextraction techniques.

    Science.gov (United States)

    Spietelun, Agata; Marcinkowski, Łukasz; de la Guardia, Miguel; Namieśnik, Jacek

    2014-02-01

    Determination of analytes at trace levels in complex samples (e.g. biological or contaminated water or soils) are often required for the environmental assessment and monitoring as well as for scientific research in the field of environmental pollution. A limited number of analytical techniques are sensitive enough for the direct determination of trace components in samples and, because of that, a preliminary step of the analyte isolation/enrichment prior to analysis is required in many cases. In this work the newest trends and innovations in liquid phase microextraction, like: single-drop microextraction (SDME), hollow fiber liquid-phase microextraction (HF-LPME), and dispersive liquid-liquid microextraction (DLLME) have been discussed, including their critical evaluation and possible application in analytical practice. The described modifications of extraction techniques deal with system miniaturization and/or automation, the use of ultrasound and physical agitation, and electrochemical methods. Particular attention was given to pro-ecological aspects therefore the possible use of novel, non-toxic extracting agents, inter alia, ionic liquids, coacervates, surfactant solutions and reverse micelles in the liquid phase microextraction techniques has been evaluated in depth. Also, new methodological solutions and the related instruments and devices for the efficient liquid phase micoextraction of analytes, which have found application at the stage of procedure prior to chromatographic determination, are presented. PMID:24401382

  2. Recent Developments in Chemical Synthesis with Biocatalysts in Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Mahesh K. Potdar

    2015-09-01

    Full Text Available Over the past decade, a variety of ionic liquids have emerged as greener solvents for use in the chemical manufacturing industries. Their unique properties have attracted the interest of chemists worldwide to employ them as replacement for conventional solvents in a diverse range of chemical transformations including biotransformations. Biocatalysts are often regarded as green catalysts compared to conventional chemical catalysts in organic synthesis owing to their properties of low toxicity, biodegradability, excellent selectivity and good catalytic performance under mild reaction conditions. Similarly, a selected number of specific ionic liquids can be considered as greener solvents superior to organic solvents owing to their negligible vapor pressure, low flammability, low toxicity and ability to dissolve a wide range of organic and biological substances, including proteins. A combination of biocatalysts and ionic liquids thus appears to be a logical and promising opportunity for industrial use as an alternative to conventional organic chemistry processes employing organic solvents. This article provides an overview of recent developments in this field with special emphasis on the application of more sustainable enzyme-catalyzed reactions and separation processes employing ionic liquids, driven by advances in fundamental knowledge, process optimization and industrial deployment.

  3. 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.

  4. Chemical treatment of liquid radioactive waste at the Boris Kidric Institute

    International Nuclear Information System (INIS)

    The results of lab-scale experiments on the chemical treatment of radioactive liquid waste collected at the Boris Kidric Institute are presented. The radioactive waste was treated by cobalt hexacyanoferrate precipitation followed by flocculation with polyelectrolyte flocculating agents. The main parameters investigated were standing time, pH and ratio of reagents. The flocculating agents were tested by filtration test and floccule stability test. Satisfactory decontamination factors by precipitation at pH 10 and good separation of solid and liquid phase by applying Praestol polyelectrolytes were obtained (author)

  5. Low voltage blue phase liquid crystal for spatial light modulators.

    Science.gov (United States)

    Peng, Fenglin; Lee, Yun-Han; Luo, Zhenyue; Wu, Shin-Tson

    2015-11-01

    We demonstrated a low-voltage polymer-stabilized blue phase liquid crystal (BPLC) for phase-only modulation with a liquid-crystal-on-silicon (LCoS). A new device configuration was developed, which allows the incident laser beam to traverse the BPLC layer four times before exiting the LCoS. As a result, the 2π phase change voltage is reduced to below 24 V in the visible region. The response time remains relatively fast (∼3  ms). The proposed device configuration enables widespread applications of BPLC spatial light modulators. PMID:26512528

  6. Liquid-liquid phase separation in highly undercooled Ni-Pb hypermonotectic alloys

    Institute of Scientific and Technical Information of China (English)

    YANG Gen-cang; XIE Hui; HAO Wei-xin; ZHANG Zhong-ming; GUO Xue-feng

    2006-01-01

    Liquid-liquid phase separation in the undercooled Ni-20%Pb(mole fraction, the same below if not mentioned)hypermonotectic melts was investigated by the observation of the water-quenched structure and DTA analysis. The results indicate that the number of spherical cells in the water-quenched microstructure increases with dropping temperature, and the cells gather and grow up obviously. The spherical cell origins from L1 phase separated from homogeneous melt, and is the product of monotectic reaction. Both results of the water-quenched structures and DTA analysis prove that liquid phase separation still occurs in the highly undercooled Ni-Pb hypermonotectic alloy melts, and liquid phase separation in the immiscible gap can not be fully inhibited by high undercooling and rapid solidification.

  7. Thermomorphic phase separation in ionic liquid-organic liquid systems - conductivity and spectroscopic characterization

    DEFF Research Database (Denmark)

    Riisager, Anders; Fehrmann, Rasmus; Berg, Rolf W.; van Hal, R.; Wasserscheid, P.

    2005-01-01

    Electrical conductivity, FT-Raman and NMR measurements are demonstrated as useful tools to probe and determine phase behavior of thermomorphic ionic liquid-organic liquid systems. To illustrate the methods, consecutive conductivity measurements of a thermomorphic methoxyethoxyethyl-imidazolium io...

  8. Copyrolysis of wood biomass and synthetic polymers mixtures. Part 2. Characterisation of the liquid phases

    Energy Technology Data Exchange (ETDEWEB)

    Marin, N.; Collura, S.; Weber, J.V. [Laboratoire de Chimie et Applications, Universite de Metz, IUT, rue Victor Demange, 57500 Saint Avold (France); Sharypov, V.I.; Beregovtsova, N.G.; Baryshnikov, S.V.; Kutnetzov, B.N. [Institute of Chemistry and Chemical Technology SB RAS, Academgorodok, 660049 Krasnoyarsk (Russia); Cebolla, V. [Instituto de Carboquimica, CSIC, Zaragoza (Spain)

    2002-10-01

    The copyrolysis of wood biomass-polyolefins was carried out in a rotating autoclave. At 400C, more than 50% (in mass) of final products are found in the liquid phase for a 1:1 (in mass) mixture. The obtained liquids are separated in a distillable liquids fraction and in an extracted liquids fraction. The first fraction can be fully characterised by gas chromatography/mass spectrometry. Only olefins, paraffins and some aromatics (benzene, toluene and xylene), issued from the polymers, are found in this fraction. The origin of the polymer plays the most important role in the chemical composition of this fraction. Some interactions with the solid issued from thermal degradation of the biomass are evidenced, for example by the presence of 2-alkenes with 3n carbon atoms. In the heavy liquids fraction, more than 80% (in mass) of the products are heavy olefins or paraffins. Schematically, we can explain the results of the copyrolysis experiments by: the biomass, whatever its origin, leads to solid, water and gas; polymer leads to liquid and gaseous olefins and paraffins; at a temperature lower than 400C, the biomass reacts and during the pyrolysis at 400C the formed solid evolves to act as a radical donor; assisted by radicals from biomass, polymer chain scission leads to the production of the light liquids; if the presence of biomass has an influence on the chemical composition of final products (particularly the light liquids fraction) their origin has, in general, only a limited effect.

  9. Laser-induced separation of hydrogen isotopes in the liquid phase

    International Nuclear Information System (INIS)

    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

  10. Dielectric properties and molecular motions of liquid crystal molecules in 4-(2-methylbytylphenyl 4-(4-octylphenylbenzoate liquid crystal having blue phase (CE8

    Directory of Open Access Journals (Sweden)

    Otowski W.

    2015-06-01

    Full Text Available Blue phase liquid crystals exhibit unique properties which are used in the new type of display. A blue-phase liquid crystal display was first presented commercially by Samsung in 2007. The blue-phase-three-color pixel display eliminates the need for color filters. This type of display uses blue-phase multi-component liquid crystal. Considering the one-component systems, it turns out that they are stable only in a very narrow range of temperatures between the isotropic and the chiral nematic phase (about 1 K. In 2005, a wide temperature range BP multi-component system was reported by researchers from the University of Cambridge. There are still several unsolved problems left. One of them is chemical stability and reliability. Therefore, the knowledge of molecular dynamics of blue phase liquid crystal is a prerequisite for understanding of blue-phase multi-component system. Understanding the molecular dynamics of a single component liquid-crystalline blue phase system can facilitate the solution of these problems. We present the molecular dynamics investigation of 4-(2-methylbytylphenyl 4-(4-octylphenylbenzoate (CE8, which may be a good candidate to form materials suitable for blue-phase liquid crystal displays.

  11. Thermodynamic modeling of chemical equilibria in liquid-liquid extraction of lutetium

    International Nuclear Information System (INIS)

    The extraction equilibrium data of lutetium from sodium succinate solution with Aliquat 336 in benzene is systematically investigated. The aqueous phase metal complexation and polymerization in the organic phase are taken into account in obtaining extraction coefficients, stability constants, hydrolysis constants, solubility product, and extraction constants. A thermodynamic model of the above equilibrium extraction data is developed for use in computer simulation of the extraction process. The correlations are based on chemical mass action principles in which the metal complexation in the aqueous phase, polymerization in the organic phase, precipitation in the aqueous phase, and aqueous phase activity coefficients are considered. Extraction behavior of other lanthanides from a succinate medium is also discussed

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

    International Nuclear Information System (INIS)

    The diameter (df) 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

  13. 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

  14. Two-Phase Slug Flow Experiments with Viscous Liquids

    OpenAIRE

    Diaz, Mariana J.C.

    2016-01-01

    The challenges behind the multiphase transport of oil and gas mixtures are increasing as the oil and gas industry is moving towards production from non-conventional reservoirs and in remote locations. Transport of high viscosity fluids in long multiphase pipelines is a particular challenge. Previous experiments have shown that gas-liquid slug flow is a frequent two-phase flow pattern at high liquid viscosities. The slug flow regime is an unstable flow, which may lead to operati...

  15. Chemical effects associated to (n, γ) nuclear reactions in diluted aqueous solutions of liquid or frozen organic halogenides

    International Nuclear Information System (INIS)

    Chemical effects associated to nuclear transformation 37Cl (n, γ) 38Cl or 127I (n, γ) 128I in solid or liquid aqueous solutions of ethyl iodide, trichloro-ethylene, thyroxine or DDT irradiated in a nuclear reactor are studied. The retention of radiohalogen under its initial chemical shape decrease with solute concentration in liquid phase but is almost constant with solute dilution in the solid phase. Potential applications in neutron activation analysis evidencing halogenated molecules in irradiated media are discussed. 57 refs

  16. The Molecular Structure of the Liquid Ordered Phase

    Science.gov (United States)

    Lyman, Edward

    2014-03-01

    Molecular dynamics simulations reveal substructures within the liquid-ordered phase of lipid bilayers. These substructures, identified in a 10 μsec all-atom trajectory of liquid-ordered/liquid-disordered coexistence (Lo/Ld) , are composed of saturated hydrocarbon chains packed with local hexagonal order, and separated by interstitial regions enriched in cholesterol and unsaturated chains. Lipid hydrocarbon chain order parameters calculated from the Lo phase are in excellent agreement with 2H NMR measurements; the local hexagonal packing is also consistent with 1H-MAS NMR spectra of the Lo phase, NMR diffusion experiments, and small angle X-ray- and neutron scattering. The balance of cholesterol-rich to local hexagonal order is proposed to control the partitioning of membrane components into the Lo regions. The latter have been frequently associated with formation of so-called rafts, platforms in the plasma membranes of cells that facilitate interaction between components of signaling pathways.

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

    International Nuclear Information System (INIS)

    GERDA will search for neutrinoless double beta decay in 76Ge 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.

  18. Liquid-Liquid Phase Separation in Supersaturated Lysozyme Solutions and Associated Precipitate Formation/Crystallization

    Science.gov (United States)

    Muschol, Martin; Rosenberger, Franz

    1997-01-01

    Using cloud point determinations, the phase boundaries (binodals) for metastable liquid-liquid (L-L) separation in supersaturated hen egg white lysozyme solutions with 3%, 5%, and 7% (wlv) NaCl at pH= 4.5 and protein concentrations c between 40 and 400 mg/ml were determined. The critical temperature for the binodal increased approximately linearly with salt concentration. The coexisting liquid phases both remained supersaturated but differed widely in protein concentration. No salt repartitioning was observed between the initial and the two separated liquid phases. After the L-L separation, due to the presence of the high protein concentration phase, crystallization occurred much more rapidly than in the initial solution. At high initial protein concentrations, a metastable gel phase formed at temperatures above the liquid binodal. Both crystal nucleation and gel formation were accelerated in samples that had been cycled through the binodal. Solutions in the gel and L-L regions yielded various types of precipitates. Based on theoretical considerations, previous observations with other proteins, and our experimental results with lysozyme, a generic phase diagram for globular proteins is put forth. A limited region in the (T,c) plane favorable for the growth of protein single crystals is delineated.

  19. Three-Dimensional Graphene-Based Microbarriers for Controlling Release and Reactivity in Colloidal Liquid Phases.

    Science.gov (United States)

    Creighton, Megan A; Zhu, Wenpeng; van Krieken, Finn; Petteruti, Robert A; Gao, Huajian; Hurt, Robert H

    2016-02-23

    Two-dimensional materials are of great interest as high-performance molecular barriers. Graphene in particular is atomically thin, is impermeable to all molecules, and in some forms can be easily deposited over large areas into planar multilayer films that have been shown to suppress molecular transport. Graphene and graphene oxide sheets are also known to spontaneously self-assemble at liquid-liquid interfaces on the surfaces of dispersed droplets, but much less is known about the barrier properties of these ultrathin films in 3D curved microgeometries. This article demonstrates that 3D films self-assembled from graphene oxide or reduced graphene oxide sheets can be exploited to control the release of small molecules from dispersed liquid phase droplets by evaporation. The release rate and containment time can be tuned by addition of multivalent cations that recruit additional sheets from the bulk liquid to the interface, which is shown by molecular dynamics to occur by an electrostatic bridging mechanism. 3D graphene-based films on droplet surfaces can also be used to control the release and transport of soluble molecules from the droplet to surrounding bulk solvent phases. In some cases, the release can be effectively stopped to produce unique kinetically trapped emulsion phases consisting of two fully miscible but segregated liquids. Finally, interfacial graphene-based films are also shown to control interfacial chemical reaction processes by serving as transport barriers between the phases or by intercepting reactive cross-phase molecular collisions. This reaction control is demonstrated by using 3D graphene-based microbarriers to protect oxidation-sensitive oils from attack by aqueous-phase reactive oxygen species, which is an undesirable pathway implicated in many chemical product degradation and spoilage processes. PMID:26775824

  20. Liquid Missile Fuels as Means of Chemical Terrorist Attack

    International Nuclear Information System (INIS)

    Modern world is faced with numerous terrorist attacks whose goals, methods and means of the conduct are various. It seems that we have entered the era when terrorism, one's own little terrorism, is the easiest and the most painless way of achieving a goal. That is why that such a situation has contributed to the necessity for strengthening individual and collective protection and safety, import and export control, control of the production and illegal sale of the potential means for delivering terrorist act. It has also contributed to the necessity for devising means of the delivery. For more than 10 years, a series of congresses on CB MTS Industry has pointed at chemicals and chemical industry as potential means and targets of terrorism. The specialization and experience of different authors in the field of the missile technology and missile fuels, especially those of Eastern origin, and the threat that was the reality of the war conflicts in 1990s was the reason for making a scientific and expert analysis of the liquid missile fuels as means of terrorism. There are not many experts in the field of NBC protection who are familiar with the toxicity and reaction of liquid missile fuels still lying discarded and unprotected in abandoned barracks all over Europe and Asia. The purpose of this paper is to draw public attention to possible different abuses of liquid missile fuels for a terrorist purpose, as well as to possible consequences and prevention measures against such abuses. (author)

  1. Liquid-liquid phase separation in mixed organic/inorganic single aqueous aerosol droplets

    OpenAIRE

    Stewart, D J; Cai, C.; Nayler, J.; Preston, T. C.; J. P. Reid; Krieger, U. K.; Marcolli, C.; Zhang, Y H

    2015-01-01

    Direct measurements of the phase separation relative humidity (RH) and morphology of aerosol particles consisting of liquid organic and aqueous inorganic domains are presented. Single droplets of mixed phase composition are captured in a gradient force optical trap, and the evolving size, refractive index (RI), and morphology are characterized by cavity-enhanced Raman spectroscopy. Starting at a RH above the phase separation RH, the trapped particle is dried to lower RH and the transition to ...

  2. Illusions of phase coexistence: Comments on "Metastable liquid-liquid transition ..." by J. C. Palmer et al., Nature 510, 385 (2014)

    OpenAIRE

    Chandler, David

    2014-01-01

    The recent paper cited above claims that a molecular simulation of one specific model of supercooled water establishes a stable interface separating two metastable liquid phases, which would imply the existence of metastable two-liquid criticality for that model. Here, we note that this claim conflicts with fundamental principles and with earlier work published in the \\textit{Journal of Chemical Physics}, and we show that the claim is unjustified by the data put forward to support the conclus...

  3. Recent progress of nuclear liquid gas phase transition

    Institute of Scientific and Technical Information of China (English)

    MA Yu-Gang; SHEN Wen-Qing

    2004-01-01

    Recent progress on nuclear liquid gas phase transition (LGPT) has been reviewed, especially for the signals of LGPT in heavy ion collisions. These signals include the power-law charge distribution, cluster emission rate, nuclear Zipf law, bimodality, the largest fluctuation of the fragments, △ -scaling, caloric curve, phase coexistence diagram, critical temperature, critical exponent analysis, negative specific heat capacity and spinodal instability etc. The systematic works of the authors on experimental and theoretical LGPT are also introduced.

  4. A model of liquid phase sintering by the homogenization

    Science.gov (United States)

    Pernin, Jean-Noël; Clementz, Philippe

    We study the first stage of liquid phase sintering, when the particles rearrangement due to capillary forces is over. We give the boundary value problem satisfied by the displacement field of points of the medium in the phase of elastic compression of solid particles, for given capillary forces acting as a density of external forces, by using the homogenization method and we characterize the mechanical behavior of this constrained medium from the material properties of each elementary components.

  5. Perhydroazulene-based liquid-crystalline materials with smectic phases

    OpenAIRE

    Zakir Hussain; Henning Hopf; S. Holger Eichhorn

    2012-01-01

    New liquid-crystalline materials with a perhydroazulene core were synthesized and the stereochemistry of these compounds was investigated. The mesomorphic properties of the new LC compounds were investigated by differential scanning colorimetry, polarizing optical microscopy and X-ray diffraction. We report here on the LC properties of nonchiral materials, which predominantly exhibit smectic phases and display nematic phases only within narrow temperature ranges. The dependence of the mesogen...

  6. Aspects of two-phase gas--liquid flow

    International Nuclear Information System (INIS)

    A wide range of topics related to current research on liquid-gas flow is reviewed, and the relevance of these topics to the design of heat exchangers is discussed. Information is included on flow patterns; system variables; mathematical models for parallel flow and non-parallel flow; critical two-phase flow; unsteady flow; and types of two-phase flow equipment used in industry. (U.S.)

  7. Microchip device for liquid phase analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ramsey, j.m.

    2000-05-01

    The lab-on-a-chip concept has enabled miniature instruments to be developed that allow the rapid execution and automation of fluidic operations such as valving, separation, dilution, mixing, and flow splitting upon the proper application of a motive (driving) force. The integration of these simple operations to perform complete, multiple-step chemical assays is rapidly becoming a reality. Such compact, monolithic devices potentially enjoy advantages in speed, cost, automation, reagent consumption, and waste generation compared to existing laboratory-scale instruments. Initial reports of these microfluidic devices focused on combining various electrokinetically driven separation methods including microchip electrophoresis, gel electrophoresis, micellar electrokinetic chromatography (MEKC) and open channel electrochromatography (OCEC) with fluidic valving to introduce sample plugs into the separation channel. Other operations have quickly been integrated with the separations and fluidic valving on these microchips. For example, integrated devices with mixers/diluters for precolumn and postcolumn analyte derivatization, deoxyribonucleic acid (DNA) restriction digests, enzyme assays, and polymerase chain reaction (PCR) amplification have been added to the basic design. Integrated mixers that can perform solvent programming for both MEKC and OCEC have also been demonstrated. These examples are simple, yet powerful, demonstrations of the potential for lab-on-a-chip devices. In this report, three key areas for improved performance of these devices are described: on-chip calibration techniques, enhanced separative performance, and enhanced detection capabilities.

  8. Improving Heterogeneous Catalyst Stability for Liquid-phase Biomass Conversion and Reforming

    OpenAIRE

    Héroguel, Florent Emmanuel; Rozmysłowicz, Bartosz; Luterbacher, Jeremy

    2015-01-01

    Biomass is a possible renewable alternative to fossil carbon sources. Today, many bio-resources can be converted to direct substitutes or suitable alternatives to fossil-based fuels and chemicals. However, catalyst deactivation under the harsh, often liquid-phase reaction conditions required for biomass treatment is a major obstacle to developing processes that can compete with the petrochemical industry. This review presents recently developed strategies to limit reversible and irreversible ...

  9. Phase equilibria in stratified thin liquid films stabilized by colloidal particles

    OpenAIRE

    Blawzdziewicz, J.; Wajnryb, E.

    2005-01-01

    Phase equilibria between regions of different thickness in thin liquid films stabilized by colloidal particles are investigated using a quasi-two-dimensional thermodynamic formalism. Appropriate equilibrium conditions for the film tension, normal pressure, and chemical potential of the particles in the film are formulated, and it is shown that the relaxation of these parameters occurs consecutively on three distinct time scales. Film stratification is described quantitatively for a hard-spher...

  10. Preparation of Hydroxyapatite/Polylactide Bicomposites by Absorption Process in Liquid Phase

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The hydroxyapatite/polylactide biocomposites were prepared by absorption process in liquid phase. The method avoided many disadvantages, such as interfusion of chemical impurity substances, nonuniformity dispersal of HA in PLA, low molecular weight of PLA. HA particles were uniformly dispersed in PlA matrix,and shawed well adhesion with PLA matrix. The biocomposites have the higher mechanical properties and suitable decomposable capability.

  11. Separation of Chlorella vulgaris from liquid phase using bioflocculants

    Directory of Open Access Journals (Sweden)

    Gizem Günay

    2014-12-01

    results showed that C. vulgaris was partially separated from the liquid phase. However, the experiments will continue for the purpose of increasing the flocculating activity. Getting successfully experimental results with kaolin showed that bioflocculant has a potential use in wastewater treatment. For this reason, it also is thought to analyze the effect of bioflocculant on the wastewater treatment with further studies.[¤

  12. 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,

  13. KINETICS OF CHEMICAL TRANSFORMATIONS OF HYDROCARBONS WORKING LIQUID FH-51 AT OPERATING AIRCRAFT

    OpenAIRE

    Кузнєцова, О.; Національний авіаційний університет; Нетреба, Ж.; Національний авіаційний університет

    2013-01-01

    Today the French hydraulic liquid «Hydronicoil» FH-51 is used in aircraft hydrosystems of Ukraine airlines.During aircraft exploitation under the action of external factors there are chemical transformations in molecules of liquid hydrocarbons. Research on kinetics of chemical transformations of hydrocarbons of working liquidFH-51 is carried out. The model of the noted chemical transformations, which provide achievement of necessary quality level of the liquid and aircraft reliability, is fou...

  14. Peculiarities of Thermic Hysteresis by the Smectica A-Isotropic Liquid Phase Transition

    International Nuclear Information System (INIS)

    Dynamics of changes of the thermotropic and morphologic properties near the phase transition between smectic A mesophase and isotropic liquid have been investigated for two monomorphic smectogens. The thermic hysteresis and availability of the heterophase regions for the smectic A - isotropic liquid and isotropic liquid - smectic A phase transitions have been found. Key words: Smectics, Smectic A-Isotropic Liquid, Phase Transitions

  15. Experimental studies of turbulent Taylor-Couette flows: single phase and liquid-liquid dispersions

    CERN Document Server

    Ravelet, Florent; Westerweel, Jerry

    2007-01-01

    We study liquid-liquid dispersions in a turbulent Taylor-Couette flow, produced between two counterrotating coaxial cylinders. In pure Water and in counterrotation, Reynolds numbers up to 1.4 10^5 are reached. The liquids we use are a low-viscous Oil and pure Water or a Sodium Iodide solution with a refractive index matched to that of Oil, in order to get transparent dispersions. We first characterize the single-phase flow, in terms of threshold for transition to turbulence, scaling of the torque and measurements of the mean flow and of the Reynolds stress by stereoscopic PIV. We then study the increase of the dissipation in the two-phase flows and find that the torque per unit mass can be twice the torque for a single-phase flow. Long-time behaviours are also reported.

  16. Novel mode of liquid-phase microextraction: A magnetic stirrer as the extractant phase holder.

    Science.gov (United States)

    Luo, Zhi-Yuan; Liu, Hai-Yan; Shi, Zhi-Guo

    2016-01-01

    In the present study, a novel configuration of liquid-phase microextraction was proposed, in which a magnetic stirrer with a groove was used as the extractant phase holder. It was termed as magnetic stirrer liquid-phase microextraction. In this way, the stability of the organic solvent was much improved under high stirring speed; the extraction efficiency was enhanced due to the enormously enlarged contact area between the organic solvent and aqueous phase. The extraction performance of the magnetic stirrer liquid-phase microextraction was studied using chlorobenzenes as the probe analytes. A wide linearity range (20 pg/mL to 200 ng/mL) with a satisfactory linearity coefficient (r(2) > 0.998) was obtained. Limits of detection ranged from 9.0 to 12.0 pg/mL. Good reproducibility was achieved with intra- and inter-day relative standard deviations stirrer liquid-phase microextraction was simple, environmentally friendly and efficient; compared to single-drop microextraction, it had obvious advantages in terms of reproducibility and extraction efficiency. It is a promising miniaturized liquid-phase technology for real applications. PMID:26541502

  17. Profile of MIBI Liquid Phase Radiopharmaceutical for Myocardial Imaging

    Directory of Open Access Journals (Sweden)

    I. Daruwati

    2016-04-01

    Full Text Available The 99mTc-MIBI radiopharmaceutical has been used innuclear medicine in Indonesia for myocardial imaging. BATAN researchers have mastered the technology to manufacture MIBI as a liophylized 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 SnCl2 2H2O and 2.6 mg Sodium Citrate 2H2O and vial B containing 0.5 mg of [Cu(MIBI4]BF4, 1 mg of cysteine hydrochloride, and 20 mg of mannitol.The purposes of this study wereto determine the stability of two different formulations of MIBI as a liquid-phase kit, to compare theirstability in different storage condition such as in refrigerator and freezer, and to compare the ratio of activities attained between target and nontargetorgans after injection to animal model. As a diagnostic agent, MIBI was reconstituted with Technetium-99m as radionuclide tracer to 99mTc-MIBI labeled compound. The radiochemical purity of 99mTc-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 maintaineda 96.68%radiochemical purity under 52-day storage and attainedatarget-to-nontarget activity ratio of 8.22.

  18. 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.)

  19. Plasma induced liquid phase chemistry and diagnostic challenges

    Czech Academy of Sciences Publication Activity Database

    Lukeš, Petr

    Leiden : Lorentz Center, 2014 - (Bruggeman, P.; Kushner, M.; Locke, B.) ISBN N. [Workshop on Gas/Plasma-Liquid Interface: Transport, Chemistry and Fundamental Data. Leiden (NL), 04.08.2014-08.08.2014] R&D Projects: GA MŠk(CZ) LD14080 Grant ostatní: European Cooperation in Science and Technology(XE) COST TD1208 Source of funding: R - rámcový projekt EK Keywords : plasma–liquid interactions * plasmachemistry * chemical diagnostics in water Subject RIV: BL - Plasma and Gas Discharge Physics http://lorentzcenter.nl/lc/web/2014/637/info.php3?wsid=637&venue=Oort

  20. Numerical simulation of three-dimensional gas/liquid two-phase flow in a proton exchange membrane fuel cell

    Institute of Scientific and Technical Information of China (English)

    ZHUGE Weilin; ZHANG Yangjun; MING Pingwen; LAO Xingsheng; CHEN Xiao

    2007-01-01

    Investigation into the formation and transport of liquid water in proton exchange membrane fuel cells (PEMFCs) is the key to fuel cell water management.A threedimensional gas/liquid two-phase flow and heat transfer model is developed based on the multiphase mixture theory.The reactant gas flow,diffusion,and chemical reaction as well as the liquid water transport and phase change process are modeled.Numerical simulations on liquid water distribution and its effects on the performance of a PEMFC are conducted.Results show that liquid water distributes mostly in the cathode,and predicted cell performance decreases quickly at high current density due to the obstruction of liquid water to oxygen diffusion.The simulation results agree well with experimental data.

  1. Liquid Phase Sintering of Highly Alloyed Stainless Steel

    DEFF Research Database (Denmark)

    Mathiesen, Troels

    1996-01-01

    calculations, made by use of the computer programme Thermo-Calc, were also correlated with the observed microstructure. Corrosion measurements by electrochemical techniques show no signs of intergranular corrosion in contrast to the case of AISI 316L based steel. Furthermore most of the material showed......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...

  2. Cone-shaped membrane liquid phase micro extraction

    International Nuclear Information System (INIS)

    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)

  3. Density functional theory of gas-liquid phase separation in dilute binary mixtures.

    Science.gov (United States)

    Okamoto, Ryuichi; Onuki, Akira

    2016-06-22

    We examine statics and dynamics of phase-separated states of dilute binary mixtures using density functional theory. In our systems, the difference of the solvation chemical potential between liquid and gas [Formula: see text] (the Gibbs energy of transfer) is considerably larger than the thermal energy [Formula: see text] for each solute particle and the attractive interaction among the solute particles is weaker than that among the solvent particles. In these conditions, the saturated vapor pressure increases by [Formula: see text], where [Formula: see text] is the solute density added in liquid. For [Formula: see text], phase separation is induced at low solute densities in liquid and the new phase remains in gaseous states, even when the liquid pressure is outside the coexistence curve of the solvent. This explains the widely observed formation of stable nanobubbles in ambient water with a dissolved gas. We calculate the density and stress profiles across planar and spherical interfaces, where the surface tension decreases with increasing interfacial solute adsorption. We realize stable solute-rich bubbles with radius about 30 nm, which minimize the free energy functional. We then study dynamics around such a bubble after a decompression of the surrounding liquid, where the bubble undergoes a damped oscillation. In addition, we present some exact and approximate expressions for the surface tension and the interfacial stress tensor. PMID:27115676

  4. Determination of kava lactones in food supplements by liquid chromatography-atmospheric pressure chemical ionisation tandem mass spectrometry

    NARCIS (Netherlands)

    Bobeldijk, I.; Boonzaaijer, G.; Spies-Faber, E.J.; Vaes, W.H.J.

    2005-01-01

    Reversed-phase liquid chromatography and detection with atmospheric pressure chemical ionisation tandem mass spectrometry was used for the determination of kava extracts in herbal mixtures. One percent of kava extract can be detected, corresponding to approximately 0.05-0.2 mg/g of the individual ka

  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–Liquid Equilibrium Coupled with Chemical Reaction (Transesterification)

    Czech Academy of Sciences Publication Activity Database

    Wichterle, Ivan; Aim, Karel

    - : -, 2005 - (Domanska-Zelazna, U.; Malanowski, S.), s.68-69 ISBN 83-920719-1-3. [European Symposium on Applied Thermodynamics ESAT 2005 /21./. Jurata (PL), 01.06.2005-05.06.2005] R&D Projects: GA ČR(CZ) GA203/03/1588 Institutional research plan: CEZ:AV0Z40720504 Keywords : phase equilibria * chemical equilibria * transesterification Subject RIV: CF - Physical ; Theoretical Chemistry

  7. 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

    2016-03-01

    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

  8. 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...

  9. 4He glass phase: A model for liquid elements

    Science.gov (United States)

    Tournier, Robert F.; Bossy, Jacques

    2016-08-01

    The specific heat of liquid helium confined under pressure in nanoporous material and the formation, in these conditions, of a glass phase accompanied by latent heat are known. These properties are in good agreement with a recent model predicting, in liquid elements, the formation of ultrastable glass having universal thermodynamic properties. The third law of thermodynamics involves that the specific heat decreases at low temperatures and consequently the effective transition temperature of the glass increases up to the temperature where the frozen enthalpy becomes equal to the predicted value. The glass residual entropy is about 23.6% of the melting entropy.

  10. Liquid phase separating mechanism and preparation techniques of immiscible alloys

    Institute of Scientific and Technical Information of China (English)

    刘源; 李言祥; 郭景杰; 贾均; 苏彦庆; 丁宏升

    2002-01-01

    Immiscible alloys have attracted growing interest for their valuable physical and mechanical properties. However, their production is difficult because of metallurgical problems in which there is a serious tendency for gravity separation in the region of the miscibility gap. So far the study on the liquid separation mechanism is still one of the important projects in the spatial materials science and the spatial fluid science. The studied results about the liquid phase separating mechanism of immiscible alloys are presented, at the same time the preparation techniques of homogeneous immiscible alloys are summarized, and the existing problems and the related researching areas in the future are also pointed out.

  11. Induced smectic phases of stoichiometric liquid crystal mixtures.

    Science.gov (United States)

    Sugisawa, Shin-Ya; Tabe, Yuka

    2016-03-16

    We revealed the detailed structures of induced smectic liquid crystal (LC) phases composed of a binary mixture of charge-transfer (CT) LC substances. Although neither of the constituents had highly ordered smectic phases, the mixture exhibited smectic-E (SmE) or smectic-B (SmB) phases when mixed at ratios of 1 : 1 and 2 : 3, respectively. The results of polarized optical microscopy, differential scanning calorimetry, X-ray diffraction, and infrared spectroscopy indicated that the induced smectic phases were stabilized by an exquisite balance between the CT interactions, dipolar interactions, and excluded volume effects. We proposed a possible model for the molecular arrangements in the SmE and SmB phases, which consistently explained the experimental results including the stoichiometric ratios. PMID:26898174

  12. Superfluid helium 2 liquid-vapor phase separation: Technology assessment

    Science.gov (United States)

    Lee, J. M.

    1984-01-01

    A literature survey of helium 2 liquid vapor phase separation is presented. Currently, two types of He 2 phase separators are being investigated: porous, sintered metal plugs and the active phase separator. The permeability K(P) shows consistency in porous plug geometric characterization. Both the heat and mass fluxes increase with K(P). Downstream pressure regulation to adjust for varying heat loads and both temperatures is possible. For large dynamic heat loads, the active phase separator shows a maximum heat rejection rate of up to 2 W and bath temperature stability of 0.1 mK. Porous plug phase separation performance should be investigated for application to SIRTF and, in particular, that plugs of from 10 to the minus ninth square centimeters to 10 to the minus eighth square centimeters in conjunction with downstream pressure regulation be studied.

  13. Design criteria for extraction with chemical reaction and liquid membrane permeation

    Science.gov (United States)

    Bart, H. J.; Bauer, A.; Lorbach, D.; Marr, R.

    1988-01-01

    The design criteria for heterogeneous chemical reactions in liquid/liquid systems formally correspond to those of classical physical extraction. More complex models are presented which describe the material exchange at the individual droplets in an extraction with chemical reaction and in liquid membrane permeation.

  14. 46 CFR 194.05-19 - Combustible liquids as chemical stores-Detail requirements.

    Science.gov (United States)

    2010-10-01

    ... combustible liquids shall be regulated by the appropriate portions of 49 CFR parts 172, 173, and 176 or part... 46 Shipping 7 2010-10-01 2010-10-01 false Combustible liquids as chemical stores-Detail... and Marking § 194.05-19 Combustible liquids as chemical stores—Detail requirements. (a)...

  15. 46 CFR 194.05-9 - Flammable liquid chemical stores-Detail requirements.

    Science.gov (United States)

    2010-10-01

    ... regulated by the appropriate portions of 49 CFR parts 172, 173, and 176 or part 147 of Subchapter N... 46 Shipping 7 2010-10-01 2010-10-01 false Flammable liquid chemical stores-Detail requirements... and Marking § 194.05-9 Flammable liquid chemical stores—Detail requirements. (a) Flammable liquids...

  16. 46 CFR 194.05-13 - Corrosive liquids as chemical stores-Detail requirements.

    Science.gov (United States)

    2010-10-01

    ... liquids are regulated by the appropriate portions of 49 CFR parts 172, 173, and 176 or part 147 of... 46 Shipping 7 2010-10-01 2010-10-01 false Corrosive liquids as chemical stores-Detail requirements... and Marking § 194.05-13 Corrosive liquids as chemical stores—Detail requirements. (a)...

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

    Science.gov (United States)

    Reisman, Shaina; Giovambattista, Nicolas

    2013-02-14

    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, P(LDA-HDA)(T) and P(HDA-LDA)(T), respectively. In addition, the compression-induced amorphization line, at which the low-pressure crystal (LPC) transforms to HDA, P(LPC-HDA)(T), is determined. As originally proposed by Poole et al. [Phys. Rev. E 48, 4605 (1993)] simulations suggest that the P(LDA-HDA)(T) and P(HDA-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 P(LPC-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 P(LDA-HDA)(T), P(HDA-LDA)(T), P(LPC-HDA)(T) loci. The competition between glass polyamorphism and crystallization is also addressed. At our "fast rate," crystallization can be partially suppressed and the glass

  18. Evidence of a liquid-liquid phase transition in hot dense hydrogen.

    Science.gov (United States)

    Dzyabura, Vasily; Zaghoo, Mohamed; Silvera, Isaac F

    2013-05-14

    We use pulsed-laser heating of hydrogen at static pressures in the megabar pressure region to search for the plasma phase transition to liquid atomic metallic hydrogen. We heat our samples substantially above the melting line and observe a plateau in a temperature vs. laser power curve that otherwise increases with power. This anomaly in the heating curve appears correlated with theoretical predictions for the plasma phase transition. PMID:23630287

  19. 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 resp...... liquids to the weakly ordered low-density liquids upon cooling.......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...... response in the same superheated region. We find that the LLPT in the Cu46Zr46Al8 melt is reversible above 1350 K upon repeated heating and cooling. Based on the concept of fluid clustering in metallic melts, the reversible LLPT is attributed to the structural transition from the strongly ordered high-density...

  20. 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.

  1. New theory for competing interactions and microstructures in partially-ordered (liquid-crystalline) phases

    International Nuclear Information System (INIS)

    A summary of results from a unique statistical-physics theory to predict and explain competing interactions and resulting microstructures in some partially-ordered [in this case, liquid-crystalline (LC)] phases is presented. The static aspects of both partial orientational and partial positional ordering of the molecules into various microstructures in these phases (including the incommensurate smectic-Ad phase) can be understood in terms of various competing interactions (both entropic and energetic) involved in the packing together of the different molecular sub-units at given pressures and temperatures. These microstructures are predicted and explained (using no ad hoc or arbitrarily adjustable parameter) as a function of molecule chemical structure [including lengths and shapes (from bond lengths and angles), intramolecular rotations, site-site polarizabilities and pair potentials, dipole moments, etc]. Theoretical results are presented for the nematic, re-entrant nematic, smectic-Ad, and smectic-Al LC phases and the isotropic phase

  2. Poly(ionic liquid)s as phase splitting promoters in aqueous biphasic systems.

    Science.gov (United States)

    João, Karen G; Tomé, Liliana C; Isik, Mehmet; Mecerreyes, David; Marrucho, Isabel M

    2015-11-01

    Aqueous biphasic systems (ABSs) provide a sustainable and efficient alternative to conventional liquid-liquid extraction techniques with volatile organic solvents, and can be used for the extraction, recovery, and purification of diverse solutes. In this work, and for the first time, ABSs composed of poly(ionic liquid)s (PILs) and inorganic salts were measured at 25 °C and atmospheric pressure. New PILs having pyrrolidinium polycations combined with different counter-anions, namely acetate [Ac](-), trifluoroacetate [TFAc](-), hexanoate [Hex](-), adipate [Adi](-), and citrate [Cit](-) were synthesized, by a simple and environmentally-friendly procedure, and characterized. The effect of the PIL features, namely molecular weight and anionic character, and other experimental variables, such as temperature, on the phase splitting ability was researched. The aptitude of the studied ABS to be implemented as separation technologies was also evaluated through the use of a model biomolecule, tryptophan. PMID:26421939

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

    Science.gov (United States)

    Raut, Ashlesha S; Kalonia, Devendra S

    2016-05-01

    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. PMID:27017836

  4. Quantum phase transitions out of the heavy Fermi liquid

    Energy Technology Data Exchange (ETDEWEB)

    Senthil, T. [Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Sachdev, Subir [Department of Physics, Yale University, P.O. Box 208120, New Haven, CT 06520-8120 (United States)]. E-mail: subir.sachdev@yale.edu; Vojta, Matthias [Institut fuer Theorie der Kondensierten Materie, Universitaet Karlsruhe, 76128 Karlsruhe (Germany)

    2005-04-30

    We review recent work on the instability of the heavy Fermi liquid state (FL) of the Kondo lattice towards a magnetic metal in which the local moments are not part of the Fermi sea. Using insights drawn from the theory of deconfined quantum criticality of insulating antiferromagnets, we discuss the possibility of a direct second-order transition between the heavy Fermi liquid and such a magnetic metal. We suggest the presence of at least two distinct diverging time scales-the shorter one describes fluctuations associated with the reconstruction of the Fermi surface, while a longer one describes fluctuations of the magnetic order parameter. The intermediate time scale physics on the magnetic side is suggested to be that of a novel fractionalized Fermi liquid (FL*) state with deconfined neutral S=12 excitations. This could ultimately devolve into the magnetic phase with conventional order at one of the larger time scales. Experimental implications for this scenario are noted.

  5. Quantum phase transitions out of the heavy Fermi liquid

    International Nuclear Information System (INIS)

    We review recent work on the instability of the heavy Fermi liquid state (FL) of the Kondo lattice towards a magnetic metal in which the local moments are not part of the Fermi sea. Using insights drawn from the theory of deconfined quantum criticality of insulating antiferromagnets, we discuss the possibility of a direct second-order transition between the heavy Fermi liquid and such a magnetic metal. We suggest the presence of at least two distinct diverging time scales-the shorter one describes fluctuations associated with the reconstruction of the Fermi surface, while a longer one describes fluctuations of the magnetic order parameter. The intermediate time scale physics on the magnetic side is suggested to be that of a novel fractionalized Fermi liquid (FL*) state with deconfined neutral S=12 excitations. This could ultimately devolve into the magnetic phase with conventional order at one of the larger time scales. Experimental implications for this scenario are noted

  6. MHD Generators Operating with Two-Phase Liquid Metal Flows

    International Nuclear Information System (INIS)

    A simplified one- component liquid metal MHD cycle which utilizes two-phase mixtures passing directly through the generator has been proposed and is being studied. Analysis indicates that a nuclear dual-cycle power system utilizing the proposed liquid metal conversion scheme as a topping cycle has overall efficiencies that are comparable to a plasma dual-cycle system at much lower,temperatures. The key to the potential of this cycle is the performance of the MHD generator operating with two-phase mixtures. A large NaK-N2 loop capable of accommodating both d.c. conduction or a.c. induction generators operating with either single-phase or two-phase flows has been built and recently put into operation. Recirculating NaK flow rates up to 200 gal/min and gas flows of 750 ft3/min can be obtained. The efficiency of a generator operating with two-phase flow will depend upon the nature of the flow and the degree to which the total entering liquid flow.interacts with the magnetic field. Because the flow pattern of a two-phase mixture changes from a dispersion of gas in liquid to a dispersion of liquid in gas as the mixture quality is increased, two different types of generators are proposed and are being studied. In the first generator, referred to as a film generator, the two-phase mixture enters at a slight angle to the lower surface of the generator. The liquid is separated by impingement. The high-velocity free surface liquid film that is formed interacts with a transverse magnetic film. The efficiency of this type of generator is a function of the separation ratio, skin friction and momentum losses. A 2 kW version of the generator has been built and is currently being run. Initial tests up to 250 W have been made, which have shown that the generator concept is feasible and that the flow is stable. This generator has run with inlet qualities to 0.05 and magnetic fields up to 12 kG. Measured voltages and amperages have ranged to 0.60 V and 60 A. It is planned to continue

  7. 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.

  8. 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.

  9. Modeling Non-aqueous Phase Liquid Displacement Process

    Institute of Scientific and Technical Information of China (English)

    Yang Zhenqing; Shao Changjin; Zhou Guanggang; Qiu Chao

    2007-01-01

    A pore-network model physically based on pore level multiphase flow was used to study the water-non-aqueous phase liquid (NAPL) displacement process, especially the effects of wettability, water-NAPL interfacial tension, the fraction of NAPL-wet pores, and initial water saturation on the displacement. The computed data show that with the wettability of the mineral surfaces changing from strongly water-wet to NAPL-wet, capillary pressure and the NAPL relative permeability gradually decrease, while water-NAPL interfacial tension has little effect on water relative permeability, but initial water saturation has a strong effect on water and NAPL relative permeabilities. The analytical results may help to understand the micro-structure displacement process of non-aqueous phase liquid and to provide the theoretical basis for controlling NAPL migration.

  10. Liquid-phase microextraction in a microfluidic-chip

    DEFF Research Database (Denmark)

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

    2012-01-01

    In this work, a microfluidic-chip based system for liquid-phase microextraction (LPME-chip) was developed. Sample solutions were pumped into the LPME-chip with a micro-syringe pump at a flow rate of 3-4µLmin(-1). Inside the LPME chip, the sample was in direct contact with a supported liquid...... electrophoresis for exact quantification, or on-line by UV detection or electrospray ionization mass spectrometry for time profiling of concentrations. The LPME-chip was found to be highly effective, and extraction efficiencies were in the range of 52-91%. When the flow of acceptor phase was turned off during...... that the LPME-chip has great potentials for very efficient analyte enrichments from limited sample volumes in the future....

  11. Entransy dissipation minimization for liquid-solid phase change processes

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The liquid-solid phase change process of a simple one-dimensional slab is studied in this paper.By taking entransy dissipation minimization as optimization objective,the optimal external reservoir temperature profiles are derived by using optimal control theory under the condition of a fixed freezing or melting time.The entransy dissipation corresponding to the optimal heat exchange strategies of minimum entransy dissipation is 8/9 of that corresponding to constant reservoir temperature operations,which is independent of all system parameters.The obtained results for entransy dissipation minimization are also compared with those obtained for the optimal heat exchange strategies of minimum entropy generation and constant reservoir temperature operations by numerical examples.The obtained results can provide some theoretical guidelines for the choice of optimal cooling or heating strategy in practical liquid-solid phase change processes.

  12. Flow growth and liquid phase epitaxy of oxides

    International Nuclear Information System (INIS)

    The state of the art in flux growth and liquid phase epitaxy has been done. The world wide literature on interesting topic has been cited. The particular methods and their technical solutions as well as the conditions necessary for crystal growth have been described in detail. Many examples have been shown concerned the broad spectrum of interesting material preparation.The composition of crystallized systems and the structure of obtained monocrystals have been reviewed and discussed. 182 refs, 25 figs, 8 tabs

  13. Neutron Radiography Analysis of a Transient Liquid Phase Joint

    OpenAIRE

    Ballhausen, H.; Abele, H.; Eccleston, R. S.; Gaehler, R.; Smith, A. J.; A. Steuwer; Van Overberghe, A.

    2006-01-01

    Neutron radiography in many cases is the only non-destructive technique available for the analysis of a wide range of samples from metallurgy, materials engineering and materials testing. In this paper the potential of the technique is illustrated for a transient liquid phase (TLP) joint. TLP bonding produces interface free and stress free joints. The quality and properties of the joint depend on the diffusion of an interlayer into the base material. A TLP joint is visualised and the diffusio...

  14. Non-aqueous phase liquid spreading during soil vapor extraction

    OpenAIRE

    Kneafsey, Timothy J.; HUNT, JAMES R.

    2004-01-01

    Many non-aqueous phase liquids (NAPLs) are expected to spread at the air – water interface, particularly under non-equilibrium conditions. In the vadose zone, this spreading should increase the surface area for mass transfer and the efficiency of volatile NAPL recovery by soil vapor extraction (SVE). Observations of spreading on water wet surfaces led to a conceptual model of oil spreading vertically above a NAPL pool in the vadose zone. Analysis of this model predicts that spreading can enha...

  15. Femtosecond spectroscopy of photolysis reactions in the liquid phase

    OpenAIRE

    Knorr, Johannes Walter

    2016-01-01

    Within the framework of this thesis, photolysis reactions in the liquid phase were investigated by means of ultrafast optical spectroscopy. Apart from molecular studies dealing with the highly spin-dependent reactivity of diphenylcarbene (DPC) in binary solvent mixtures and ligand dissociation reactions of so-called CO-releasing molecules (CORMs), special emphasis was put on the implementation and characterization of methods improving and extending the signal detection in conventiona...

  16. Phosphopeptide elution times in reversed-phase liquid chromatography

    OpenAIRE

    Kim, Jeongkwon; Petritis, Konstantinos; Shen, Yufeng; Camp, David G.; Moore, Ronald J.; Smith, Richard D.

    2007-01-01

    Elution time shifts between 33 different peptides and their corresponding phosphopeptides ranging from 4 amino acid residues to 35 amino acids in length were systematically investigated using high-resolution reversed-phase liquid chromatography (RPLC)-tandem mass spectrometry (MS/MS) analysis with trifluoroacetic acid as the ion pairing agent. Observed peptide elution time shifts for a single phosphorylation ranged from −5.28 min (for pYVPML) to +0.59 min (for HRDpSGLLDSLGR). Peptides contain...

  17. Self-polarizing terahertz liquid crystal phase shifter

    Directory of Open Access Journals (Sweden)

    Xiao-wen Lin

    2011-09-01

    Full Text Available Using sub-wavelength metallic gratings as both transparent electrodes and broadband high-efficiency polarizers, a highly-compact self-polarizing phase shifter is demonstrated by electrically tuning the effective birefringence of a nematic liquid crystal cell. The metal grating polarizers ensure a good polarizing efficiency in the range of 0.2 to 2 THz. Phase shift of more than π/3 is achieved in a 256 μm-thick cell with a saturation root mean square voltage of around 130 V in this integrated device.

  18. Commercial-Scale Demonstration of the Liquid Phase Methanol (LPMEOH(TM)) Process

    Energy Technology Data Exchange (ETDEWEB)

    None

    1997-09-30

    The Liquid Phase Methanol (LPMEOH) Demonstration Project at Kingsport, Tennessee, is a $213.7 million cooperative agreement between the U.S. Department of Energy (DOE) and Air Products Liquid Phase Conversion Company, L.P. (the Partnership). Ak Products and Chemicals, Inc. (Air Products) and Eastman Chemical Company (Eastman) formed the Partnership to execute the Demonstration Project. The LPMEOITM Process Demonstration Unit was built at a site located at the Eastman complex in Kingsport. During this reporting period, DOE accepted the recommendation to continue with dimethyl ether (DME) design verification testing (DVT). DME design verification testing studies show the liquid phase DME (LPDME) process will have a significant economic advantage for the coproduction of DME for local markets. An LPDME catalyst system with reasonable long-term activity and stzibility is being developed. Planning for a proof-of-concept test run at the LaPorte Alternative Fuels Development Unit (AFDU) was recommended. DOE issued a letter dated 31 July 1997 accepting the recommendation to continue design verification testing. In order to allow for scale-up of the manufacturing technique for the dehydration catalyst from the pilot plant to the commercial scale, the time required to produce the catalyst to the AFDU has slipped. The new estimated delivery date is 01 June 1998.

  19. Predictions of phase distribution in liquid-liquid two-component flow using FLUENT

    International Nuclear Information System (INIS)

    Eulerian multiphase model in FLUENT with a one-group interfacial area transport equation (IATE) (named 'FLUENT-IATE model' hereafter) takes into account fluid particle interactions, such as coalescence and disintegration, and therefore is expected to dynamically capture changes in the interfacial structure. In this study, the FLUENT-IATE model was applied to a liquid-liquid two-component vertical flow in a 25-mm inner diameter pipe. The two liquids were immiscible with similar densities, namely water as the continuous phase and Therminol 59 as the dispersed phase, which were used in a ground-based facility to simulate reduced-gravity two-phase flows. This study covered bubbly (drop) flow and bubbly-to-slug flow transition regimes with area-averaged void (drop) fractions from 3 to 30%. Comparisons with the experimental data indicated that for bubbly flows, the predictions of the lateral phase distributions using the FLUENT-IATE model were generally more accurate than those using the model without the IATE. In addition, it was demonstrated that the coalescence of fluid particles was dominated by wake entrainment and enhanced by increasing either the continuous or dispersed phase velocity. However, predictions showed disagreement with experimental data in some flow conditions for larger void fraction conditions, which fell into the bubbly-to-slug flow transition regime and might involve additional fluid particle interaction mechanisms due to the change of flow regimes. (author)

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

    International Nuclear Information System (INIS)

    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

  1. Extraction of Phthalic Acid from Aqueous Solution by Using Ionic Liquids: A Quantum Chemical Approach

    OpenAIRE

    Pilli, S; Mohanty, Kaustubha; Banerjee, Tamal

    2014-01-01

    Phthalic acid is an industrial chemical and it comes under the domain of endocrine disrupting chemicals (EDCs). Green solvents such as ionic liquids (ILs) posses good extractable capabilities for EDCs. COSMO–RS methodology is a widely accepted method for the design or selection of ionic liquids. COSMO–RS is a quantum chemical based method based on COSMO polarization charge densities. In this work the model has been used to screen the potential ionic liquids for the removal of phthalic acid fr...

  2. Josephson coupling, phase correlations, and Josephson plasma resonance in vortex liquid phase

    International Nuclear Information System (INIS)

    Josephson plasma resonance (JPR) has been introduced recently as a powerful tool to probe interlayer Josephson coupling in different regions of the vortex phase diagram in layered superconductors. In the liquid phase, the high-temperature expansion with respect to the Josephson coupling connects the Josephson plasma frequency with the phase correlation function. This function, in turn, is directly related to the pair distribution function of the liquid. We develop a recipe to extract the phase and density correlation functions from the dependencies of the plasma resonance frequency ωp(B) and the c-axis conductivity σc(B) on the ab component of the magnetic field at fixed c component. Using Langevin dynamic simulations of two-dimensional vortex arrays we calculate density and phase correlation functions at different temperatures. Calculated phase correlations describe very well the experimental angular dependence of the plasma resonance field. We also demonstrate that in the case of weak damping in the liquid phase, broadening of the JPR line is caused mainly by random Josephson coupling arising from the density fluctuations of pancake vortices. In this case the JPR line has a universal shape, which is determined only by parameters of the superconductors and temperature

  3. Single-reactor process for producing liquid-phase organic compounds from biomass

    Science.gov (United States)

    Dumesic, James A.; Simonetti, Dante A.; Kunkes, Edward L.

    2011-12-13

    Disclosed is a method for preparing liquid fuel and chemical intermediates from biomass-derived oxygenated hydrocarbons. The method includes the steps of reacting in a single reactor an aqueous solution of a biomass-derived, water-soluble oxygenated hydrocarbon reactant, in the presence of a catalyst comprising a metal selected from the group consisting of Cr, Mn, Fe, Co, Ni, Cu, Mo, Tc, Ru, Rh, Pd, Ag, W, Re, Os, Ir, Pt, and Au, at a temperature, and a pressure, and for a time sufficient to yield a self-separating, three-phase product stream comprising a vapor phase, an organic phase containing linear and/or cyclic mono-oxygenated hydrocarbons, and an aqueous phase.

  4. Single-reactor process for producing liquid-phase organic compounds from biomass

    Energy Technology Data Exchange (ETDEWEB)

    Dumesic, James A.; Simonetti, Dante A.; Kunkes, Edward L.

    2015-12-08

    Disclosed is a method for preparing liquid fuel and chemical intermediates from biomass-derived oxygenated hydrocarbons. The method includes the steps of reacting in a single reactor an aqueous solution of a biomass-derived, water-soluble oxygenated hydrocarbon reactant, in the presence of a catalyst comprising a metal selected from the group consisting of Cr, Mn, Fe, Co, Ni, Cu, Mo, Tc, Ru, Rh, Pd, Ag, W, Re, Os, Ir, Pt, and Au, at a temperature, and a pressure, and for a time sufficient to yield a self-separating, three-phase product stream comprising a vapor phase, an organic phase containing linear and/or cyclic mono-oxygenated hydrocarbons, and an aqueous phase.

  5. Commercial-Scale Demonstration of the Liquid Phase methanol (LPMEOH) Process A DOE Assessment

    Energy Technology Data Exchange (ETDEWEB)

    National Energy Technology Laboratory

    2003-10-27

    The U.S. Department of Energy (DOE) Clean Coal Technology (CCT) Program seeks to offer the energy marketplace more efficient and environmentally benign coal utilization technology options by demonstrating them in industrial settings. This document is a DOE post-project assessment (PPA) of one of the projects selected in Round III of the CCT Program, the commercial-scale demonstration of the Liquid Phase Methanol (LPMEOH{trademark}) Process, initially described in a Report to Congress by DOE in 1992. Methanol is an important, large-volume chemical with many uses. The desire to demonstrate a new process for the production of methanol from coal, prompted Air Products and Chemicals, Inc. (Air Products) to submit a proposal to DOE. In October 1992, DOE awarded a cooperative agreement to Air Products to conduct this project. In March 1995, this cooperative agreement was transferred to Air Products Liquid Phase Conversion Company, L.P. (the Partnership), a partnership between Air Products and Eastman Chemical Company (Eastman). DOE provided 43 percent of the total project funding of $213.7 million. Operation of the LPMEOH Demonstration Unit, which is sited at Eastman's chemicals-from-coal complex in Kingsport, Tennessee, commenced in April 1997. Although operation of the CCT project was completed in December 2002, Eastman continues to operate the LPMEOH Demonstration Unit for the production of methanol. The independent evaluation contained herein is based primarily on information from Volume 2 of the project's Final Report (Air Products Liquid Phase Conversion Co., L.P. 2003), as well as other references cited.

  6. Two-Phase Reactive Systems: Transesterification and Esterification Reactions Coupled with Vapour-Liquid Equilibria in Quaternary Systems

    Czech Academy of Sciences Publication Activity Database

    Aim, Karel; Wichterle, Ivan

    2010, s. 210. ISBN N. [International Conference on Properties and Phase Equilibria for Product and Process Design PPEPPD 2010 /20./. Suzhou (CN), 16.05.2010-21.05.2010] Institutional research plan: CEZ:AV0Z40720504 Keywords : esterification reactions * vapor-liquid equilibria * chemical equilibria Subject RIV: CF - Physical ; Theoretical Chemistry http://www.ppeppd2010.cn/

  7. Luttinger liquid with complex forward scattering: Robustness and Berry phase

    Science.gov (United States)

    Dóra, Balázs; Moessner, Roderich

    2016-02-01

    Luttinger liquids (LLs) are one-dimensional systems with well-understood instabilities due to Umklapp or backscattering. We study a generalization of the Luttinger model, which incorporates a time reversal symmetry breaking interaction producing a complex forward scattering amplitude (g2 process). The resulting low energy state is still a LL and belongs to the family of interacting Schulz-Shastry models. Remarkably, it becomes increasingly robust against additional perturbations—for purely imaginary g2, both Umklapp and local backscattering are always irrelevant. Changing the phase of the interaction generates a nontrivial Berry phase, with a universal geometric phase difference between ground and a one boson excited state depending only on the LL parameter.

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

    International Nuclear Information System (INIS)

    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.)

  9. Phase separation in covalent liquids: neutron scattering and thermodynamical simulation

    International Nuclear Information System (INIS)

    This lecture shows how neutron scattering is a suitable tool to study the homogeneity of covalent liquids. 2 experimental techniques allow us to show the separation of phases: the first one is the small angle diffusion which is used to study condensed matter over distance scales from 1 to 5 nm. This method is adequate for studying the fluctuations of concentrations when phases separate or the fluctuations of density near the critical point. The second technique, less classical, is based on the measurement of the local order of 2 phases in equilibrium by using a large angle diffusion method. Both techniques are discussed, their experimental settings are presented and they are applied to the study of sulfur-tellurium and arsenic-sulfur alloys. The second technique, combined with adequate structural and thermodynamical models, has allowed us to set a direct relationship between local order and macroscopic parameters of the system. (A.C.)

  10. The removal of dinitrochlorobenzene from industrial residuals by liquid-liquid extraction with chemical reaction

    Directory of Open Access Journals (Sweden)

    G. C. M. Ferreira

    2007-09-01

    Full Text Available Nitrochlorobenzenes (NCBs are very important in the chemical industry since they have been used as raw material for the manufacture of crop protection products, as active ingredients in the pharmaceutical industry, as pigments and as antioxidants as well as for other uses. In industrial processes, NCBs are produced by monochlorobenzene (MCB nitration reactions and one of the main residuals formed is dinitrochlorobenzene (DNCB, which is mainly composed of the isomer 2,4DNCB. This subproduct, although of commercial interest when in its pure state, is generally incinerated due to the high costs of recovery treatment and purification. The objective of this study is to present an alternative to the treatment of industrial residuals containing DNCB. The technique consists of converting DNCB into sodium dinitrophenolate, which is very soluble in water and is also easy to reuse. For this purpose, liquid-liquid extraction with chemical reaction (alkaline hydrolysis with a rotating disc contactor (RDC is used. Experimental data on MCB nitration reactions as well as alkaline hydrolysis using a rotating disc contactor are presented.

  11. Printing nanoparticles from the liquid and gas phases using nanoxerography

    Science.gov (United States)

    Barry, Chad R.; Steward, Michael G.; Lwin, Nyein Z.; Jacobs, Heiko O.

    2003-10-01

    This paper reports on the directed self-assembly of nanoparticles onto charged surface areas with a resolution of 200 nm from the liquid phase and 100 nm from the gas phase. The charged areas required for this type of nanoxerographic printing were fabricated using a parallel method that employs a flexible, electrically conductive, electrode to charge a thin-film electret. As electrodes, we used metal-coated polymeric stamps and 10 µm thick doped silicon wafers carrying a pattern in topography. Each electrode was brought in contact with a thin-film electret on an n-doped silicon substrate. The charge pattern was transferred into the thin-film electret by applying a voltage pulse between the conductive electrode and the silicon substrate. Areas as large as 1 cm2 were patterned with charge with 100 nm scale resolution in 10 s. These charge patterns attract nanoparticles. A liquid-phase assembly process where electrostatic forces compete with disordering forces due to ultrasonication has been developed to assemble nanoparticles onto charged based receptors in 10 s from a liquid suspension. A gas-phase assembly process was developed that uses a transparent particle assembly module to direct particles towards the charged surface while monitoring the total charge of assembled particles. Nanoparticles were generated using a tube furnace by evaporation and condensation at the outlet. The electrostatically directed assembly of 10-100 nm sized metal (gold, silver) and 30 nm sized carbon particles was accomplished with a resolution 500-1000 times greater than the resolution of existing xerographic printers.

  12. Microstructural control of silicon carbide via liquid phase sintering

    Science.gov (United States)

    Mrotek, Sharon Robinson

    Silicon carbide ceramics with various microstructures were fabricated by controlling the amount and composition of a Y2O3-Al 2O3 liquid phase, crystallographic phase of the starting powders, trace impurities in those powders, and time and temperature of sintering and post- sintering heat-treatments. Alpha and beta SiC "seeds" were used to control grain growth during sintering. The grain size distribution and aspect ratio of the grains were determined through microstructural analysis of polished and etched samples. TEM was used in conjunction with EDS to determine the distribution of the sintering aids in the grains and the grain boundaries. Additionally, the final phase content of the samples was determined via x-ray diffraction. The fracture toughness and hardness were measured to evaluate the relative effects of the microstructural variations on the mechanical properties. Alpha silicon carbide samples exhibited a fine grained, equiaxed microstructure. Under appropriate conditions, samples prepared from beta-SiC powders underwent a phase transformation to alpha-SiC accompanied by the growth of elongated platelet grains. The addition of alpha seeds to the beta powder reduced the size of the platelets compared to unseeded samples of the same composition. If the beta to alpha phase transformation did not occur, the beta samples developed an equiaxed microstructure. The grain size of all samples decreased with increasing amounts of sintering additives. The beta to alpha phase transformation, required to obtain an elongated grain microstructure, was catalyzed by the presence of sufficient amounts of aluminum. If insufficient Al impurity was present in the powder, purposeful additions of Al metal could induce the phase transformation. Examination of the sintering progression over time indicated that the phase transformation occurred late in the sintering process and appeared to occur via a solution/reprecipitation mechanism. Post-sintering heat treatments were also used

  13. Ecotoxicology of heavy metals: Liquid-phase extraction by nanosorbents

    Science.gov (United States)

    Burakov, A.; Romantsova, I.; Babkin, A.; Neskoromnaya, E.; Kucherova, A.; Kashevich, Z.

    2015-11-01

    The paper considers the problem of extreme toxicity heavy metal compounds dissolved in wastewater and liquid emissions of industrial enterprises to living organisms and environment as a whole. The possibility of increasing extraction efficiency of heavy metal ions by sorption materials was demonstrated. The porous space of the latter was modified by carbon nanotubes (CNTs) during process of the chemical vapour deposition (CVD) of carbon on metal oxide catalysts. The increasing of the sorption capacity (10-30%) and the sorption rate of nanomodified activated carbons in comparison with standard materials in the example of absorption of Co2+ and Ni2+ ions from aqueous solutions was proven.

  14. Liquid Crystal Phase Behaviour of Attractive Disc-Like Particles

    Directory of Open Access Journals (Sweden)

    George Jackson

    2013-08-01

    Full Text Available 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.

  15. Effect of dimensionality on vapor-liquid phase transition

    Science.gov (United States)

    Singh, Sudhir Kumar

    2014-04-01

    Dimensionality play significant role on `phase transitions'. Fluids in macroscopic confinement (bulk or 3-Dimensional, 3D) do not show significant changes in their phase transition properties with extent of confinement, since the number of molecules away from the surrounding surfaces is astronomically higher than the number of molecules in close proximity of the confining surfaces. In microscopic confinement (quasi 3D to quasi-2D), however, the number of molecules away from the close proximity of the surface is not as high as is the case with macroscopic (3D) confinement. Hence, under the same thermodynamic conditions `phase transition' properties at microscopic confinement may not remain the same as the macroscopic or 3D values. Phase transitions at extremely small scale become very sensitive to the dimensions as well as the surface characteristics of the system. In this work our investigations reveal the effect of dimensionality on the phase transition from 3D to quasi-2D to 2D behavior. We have used grand canonical transition matrix Monte Carlo simulation to understand the vapor-liquid phase transitions from 3D to quasi-2D behavior. Such studies can be helpful in understanding and controlling the fluid film behaviour confined between solid surfaces of few molecular diameters, for example, in lubrication applications.

  16. A polarization independent liquid crystal phase modulation adopting surface pinning effect of polymer dispersed liquid crystals

    Science.gov (United States)

    Lin, Yi-Hsin; Tsou, Yu-Shih

    2011-12-01

    A polarization-independent liquid crystal (LC) phase modulation using the surface pinning effect of polymer dispersed liquid crystals (SP-PDLC) is demonstrated. In the bulk region of the SP-PDLC, the orientations of LC directors are randomly dispersed; thus, any polarization of incident light experiences the same averaged refractive index. In the regions near glass substrates, the LC droplets are pinned. The orientations of top and bottom droplets are orthogonal. Two eigen-polarizations of an incident light experience the same phase shift. As a result, the SP-PDLC is polarization independent. Polarizer-free microlens arrays of SP-PDLC are also demonstrated. The SP-PDLC has potential for application in spatial light modulators, laser beam steering, and electrically tunable microprisms.

  17. Crystallization and phase changes in paracetamol from the amorphous solid to the liquid phase.

    Science.gov (United States)

    Sibik, Juraj; Sargent, Michael J; Franklin, Miriam; Zeitler, J Axel

    2014-04-01

    For the case of paracetamol, we show how terahertz time-domain spectroscopy can be used to characterize the solid and liquid phase dynamics. Heating of supercooled amorphous paracetamol from 295 K in a covered sample under vacuum leads to its crystallization at 330 K. First, form III is formed followed by the transformation of form III to form II at 375 K, to form I at 405 K, and finally melting is observed around 455 K. We discuss the difference between the featureless spectra of the supercooled liquid and its liquid melt. Lastly, we studied the onset of crystallization from the supercooled liquid in detail and quantified its kinetics based on the Avrami-Erofeev model. We determined an effective rate constant of k = 0.056 min(-1) with a corresponding onset of crystallization at T = 329.5 K for a heating rate of 0.4 K min(-1). PMID:24579729

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

    Science.gov (United States)

    Griffin, DeVon W.; Marshall, Keneth L.

    2002-11-01

    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

  19. Effect of liquid entrainment on turbulent mixing rates between subchannels in gas-liquid annular two-phase flows

    International Nuclear Information System (INIS)

    Turbulent mixing rates of gas and liquid phases between adjacent subchannels have been measured for various air-water two-phase annular flows in a multiple channel consisting of two identical circular subchannels. In order to study effect of liquid entrainment in the gas core on the turbulent mixing rates, experiments were conducted for two types of liquid injection method, i.e., a small bore nozzle placed in the subchannel center and a porous wall. The result showed that the effect of liquid entrainment on the turbulent mixing rates of both phases is negligibly small. (author)

  20. 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.

  1. Clean coal technology: commercial-scale demonstration of the liquid phase methanol (LPMEOH{trademark}) process

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-04-01

    The report discusses the demonstration of Air Products and Chemical, Inc.`s Liquid Phase Methanol (LPMEOTH {trademark}) Process which is designed to convert synthesis gas derived from the gasification of coal into methanol for use as a chemical intermediate or as a low-sulfur dioxide and low-nitrogen oxides emitting alternative fuel. The project was selected for funding by the US Clean Coal Technology Program Round III in 1992. Construction of the Demonstration Project at Eastman Chemical Co`s Kingsport complex began in October 1995 and was completed in January 1997. Production rates of over 300 tons per day of methanol have been achieved and availability for the unit has exceeded 96% since startup. The LPMEOH{trademark} Process can enhance integrated gasification combined cycle (IGCC) power generation by converting part of the syngas from the gasifier to methanol which can be solid or used as a peak-sharing fuel. 50 refs., 5 figs., 7 photos.

  2. Investigations on the liquid crystalline phases of cation-induced condensed DNA

    Science.gov (United States)

    Pillai, C. K. S.; Sundaresan, Neethu; Radhakrishnan Pillai, M.; Thomas, T.; Thomas, T. J.

    2005-10-01

    Viral and nonviral condensing agents are used in gene therapy to compact oligonucleotides and plasmid DNA into nanostructures for their efficient transport through the cell membranes. Whereas viral vectors are best by the toxic effects on the immune system, most of the nonviral delivery vehicles are not effective for use in clinical system. Recent investigations indicate that the supramolecular organization of DNA in the condensed state is liquid crystalline. The present level of understanding of the liquid crystalline phase of DNA is inadequate and a thorough investigation is required to understand the nature, stability, texture and the influence of various environmental conditions on the structure of the phase. The present study is mainly concerned with the physico-chemical investigations on the liquid crystalline transitions during compaction of DNA by cationic species such as polyamines and metallic cations. As a preliminary to the above investigation, studies were conducted on the evolution of mesophase transitions of DNA with various cationic counterion species using polarized light microscopy. These studies indicated significant variations in the phase behaviour of DNA in the presence of Li and other ions. Apart from the neutralization of the charges on the DNA molecule, these ions are found to influence selectively the hydration sphere of DNA that in turn influences the induction and stabilization of the LC phases. The higher stability observed with the liquid crystalline phases of Li--DNA system could be useful in the production of nanostructured DNA. In the case of the polyamine, a structural specificity effect depending on the nature, charge and structure of the polyamine used has been found to be favoured in the crystallization of DNA.

  3. DNS based analysis of liquid phase turbulence kinetic energy equation for bubbly two-phase flow

    International Nuclear Information System (INIS)

    While the modeling of turbulent single phase flows has already reached a certain level of maturity, models for the turbulence in bubble flows are still under development. The majority of models is based on the transport equation for liquid phase turbulence kinetic energy (kL) which is recast by extending the k-equation for single phase flow with empirical closure terms to account for the dispersed phase. In this paper we investigate bubble-induced liquid phase pseudo-turbulence by direct numerical simulations (DNS) based on the volume-of-fluid method. Simulations are performed for a regular array of ellipsoidal bubbles (gas hold up a 0.8%) and for a monodisperse swarm of 8 bubbles (a 6.4 %) rising in a plane vertical channel within an otherwise stagnant liquid. In the three bubble swarm simulations the liquid viscosity is varied by a factor of 10, resulting in a change of the bubble shape from ellipsoidal to spherical, a decrease of the average bubble rise velocity by a factor of 5 and a decrease of kL by a factor of 20. The DNS data are used to perform a detailed quantitative analysis of the analytical balance equation for kL. The evaluation comprises single-phase-like terms (diffusion, dissipation, production) as well as the interfacial term that only exists for two-phase flows. The general conclusion to be drawn for the considered bubbly flows is the prominent role of the interfacial term. Because the production term due to shear stresses is so low that it can be neglected, the interfacial term is the only one that feeds the liquid phase turbulence. The different closure terms in the analytical kL-equation are compared with respective closure assumptions for the modeled kL-equation implemented in two-phase k-l, k-e and ASM turbulence models. We find that - for the bubbly flows studied here - the conventional modelling of single-phase-like terms totally fails. Encouraging results are, however, obtained for modeling of the interfacial term. A detailed analysis of

  4. A novel procedure for phase separation in dispersive liquid-liquid microextraction based on solidification of the aqueous phase.

    Science.gov (United States)

    March, J G; Cerdà, V

    2016-08-15

    In this paper, an alternative for handling the organic phase after a dispersive liquid-liquid microextraction using organic solvents lighter than water is presented. It is based on solidification (at -18°C) of the aqueous phase obtained after centrifugation, and the decantation, collection and analysis of the liquid organic layer. The extraction of nicotine in toluene, and its determination in eggplant samples was conducted as a proof of concept. The study has been carried out using standards prepared in water and the formation of the dispersion was assisted by sonication. The organic extract was analysed using gas chromatography coupled to mass spectrometry. Satisfactory analytical figures of merit as: limit of detection (0.4µgL(-1), 2ngg(-1) wet sample), limit of quantification (1.2µgL(-1), 6.5ngg(-1) wet sample), within-day precision (RSD=7%), and linearity interval (up to 384µgL(-1) nicotine) were achieved. It constituted a contribution to the handling of organic extracts after microextraction processes. PMID:27260454

  5. A review of liquid-phase catalytic hydrodechlorination

    Directory of Open Access Journals (Sweden)

    Alba Nelly Ardila Arias

    2010-04-01

    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.

  6. Liquid/solid/dual phase xenon γ-ray detectors

    International Nuclear Information System (INIS)

    It is recognized by various groups in the world that liquid xenon (LXe) is an interesting medium for the detection of γ-rays. In spite of all the experimental and theoretical effort expended during recent years, the processes that take place in this medium are not yet fully understood. We have obtained some preliminary results using an ionization chamber with a Frisch grid. This chamber could be filled with LXe and with solid xenon (SXe). We also investigated dual phase (GXe/SXe) systems. Our study will be continued with a newly developed detection cell described in this article. ((orig.))

  7. Liquid/solid/dual phase xenon γ-ray detectors

    Science.gov (United States)

    van Sonsbeek, R.; Bom, V. R.; van Eijk, C. W. E.; Hollander, R. W.; Meijvogel, K.; Okx, W. J. C.

    1994-09-01

    It is recognized by various groups in the world that liquid xenon (LXe) is an interesting medium for the detection of γ-rays. In spite of all the experimental and theoretical effort expended during recent years, the processes that take place in this medium are not yet fully understood. We have obtained some preliminary results using an ionization chamber with a Frisch grid. This chamber could be filled with LXe and with solid xenon (SXe). We also investigated dual phase (GXe/SXe) systems. Our study will be continued with a newly developed detection cell described in this article.

  8. Liquid phase epitaxy of gallium arsenide - a review

    International Nuclear Information System (INIS)

    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

  9. Geometrically-frustrated pseudogap phase of Coulomb liquids

    International Nuclear Information System (INIS)

    We study a class of models with long-range repulsive interactions of the generalized Coulomb form V(r)∼1/rα. We show that decreasing the interaction exponent in the regime αc in any dimension d≥2, reflecting the strong geometric frustration produced by long-range interactions. A nearly frozen Coulomb liquid then survives in a broad pseudogap phase found at T>Tc, which is characterized by an unusual temperature dependence of all quantities. In contrast, the leading critical behavior very close to the charge-ordering temperature remains identical as in models with short-range interactions.

  10. Liquid phase synthesis of copper indium diselenide nanoparticles

    International Nuclear Information System (INIS)

    Nanoparticles of Copper Indium diselenide (CuInSe2), belongs to I-III-VI2 family has been synthesized via liquid phase route using ethylenediamine as a solvent. Characterization of as-grown particles is done by XRD, HRTEM, DLS, optical microscopy and UV-Vis spectroscopy. X-ray diffraction pattern confirmed that the CuInSe2 nanoparticles obtained reveals chalcopyrite structure. Particle size evaluated from dynamic light scattering of as grown particle possessing radius of 90 nm. The bandgap of 1.05eV is obtained from UV-Vis spectrum which will applicable to the solar cell devices

  11. 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.

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

    International Nuclear Information System (INIS)

    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

  13. Liquid-Phase Processing of Barium Titanate Thin Films

    Science.gov (United States)

    Harris, David Thomas

    Processing of thin films introduces strict limits on the thermal budget due to substrate stability and thermal expansion mismatch stresses. Barium titanate serves as a model system for the difficulty in producing high quality thin films because of sensitivity to stress, scale, and crystal quality. Thermal budget restriction leads to reduced crystal quality, density, and grain growth, depressing ferroelectric and nonlinear dielectric properties. Processing of barium titanate is typically performed at temperatures hundreds of degrees above compatibility with metalized substrates. In particular integration with silicon and other low thermal expansion substrates is desirable for reductions in costs and wider availability of technologies. In bulk metal and ceramic systems, sintering behavior has been encouraged by the addition of a liquid forming second phase, improving kinetics and promoting densification and grain growth at lower temperatures. This approach is also widespread in the multilayer ceramic capacitor industry. However only limited exploration of flux processing with refractory thin films has been performed despite offering improved dielectric properties for barium titanate films at lower temperatures. This dissertation explores physical vapor deposition of barium titanate thin films with addition of liquid forming fluxes. Flux systems studied include BaO-B2O3, Bi2O3-BaB2O 4, BaO-V2O5, CuO-BaO-B2O3, and BaO-B2O3 modified by Al, Si, V, and Li. Additions of BaO-B2O3 leads to densification and an increase in average grain size from 50 nm to over 300 nm after annealing at 900 °C. The ability to tune permittivity of the material improved from 20% to 70%. Development of high quality films enables engineering of ferroelectric phase stability using residual thermal expansion mismatch in polycrystalline films. The observed shifts to TC match thermodynamic calculations, expected strain from the thermal expansion coefficients, as well as x-ray diffract measurements

  14. Effect of temperature in reversed phase liquid chromatography.

    Science.gov (United States)

    Guillarme, D; Heinisch, S; Rocca, J L

    2004-10-15

    The high temperature liquid chromatography (HTLC) reveals interesting chromatographic properties but even now, it misses some theoretical aspects concerning the influence of high temperature on thermodynamic and kinetic aspects of chromatography: such a knowledge is very essential for method development. In this work, the effect of temperature on solute behavior has been studied using various stationary phases which are representative of the available thermally stable materials present on the market. The thermodynamic properties were evaluated by using different mobile phases: acetonitrile-water, methanol-water and pure water. The obtained results were discussed on the basis of both type of mobile phases and type of stationary phases. Type of mobile phase was found to play an important role on the retention of solutes. The kinetic aspect was studied at various temperatures ranging from ambient temperature to high temperature (typically from about 30 to 200 degrees C) by fitting the experimental data with the Knox equation and it was shown that the efficiency is improved significantly when the temperature is increased. In this paper, we also discussed the problem of temperature control for thermostating columns which may represent a significant source of peak broadening: by taking into account the three main parameters such as heat transfer, pressure drop and band broadening resulting from the preheating tube, suitable rules are set up for a judicious choice of the column internal diameter. PMID:15527119

  15. Preparation of thin film gold based catalysts for oxidation reactions in liquid and gas phases

    International Nuclear Information System (INIS)

    This work deals with the preparation of gold on titania catalysts to make catalytic films in the less than 100 nm thickness area and its comparison with usual powder catalyst in catalytic oxidation reactions in gas and liquid phases. Titania was coated on glass plates with different thicknesses, but with ultra-low surface roughness (< 5 Å). Gold deposition was performed with usual chemical method for catalysts preparation, that is deposition–precipitation with urea. Transmission electron microscopy showed that planar samples are decorated with a high quantity (> 10 wt.% with respect to TiO2) of gold nanoparticles smaller than 2.5 nm, with a narrow size distribution. Activity in CO oxidation demonstrates the catalytic behavior of the planar samples, although they are less active than powder catalyst because of the different geometries of the reactors and catalysts. In contrast, their catalytic performances in liquid phase, benzyl alcohol oxidation, are comparable. These results validate the concept that gold planar catalysts prepared by chemical methods can present similar catalytic behavior as real powder gold catalysts. Such planar catalysts could be useful for bridging the material gap between real and model catalysts in advanced techniques, such as scanning tunnelling microscopy and spectroscopy or high-pressure photoelectron spectroscopy. - Highlights: ► Preparation of thin film of TiO2 (pure anatase) on glass with a low roughness (< 5 Å) ► High density of small gold nanoparticles on planar substrates by a chemical method ► Planar catalysts active in both gas and liquid phase oxidation reactions ► Bridging of the material gap between real and model catalysts

  16. Characterization and modelling of the dispersed phase behaviour in liquid-liquid pulsed columns

    International Nuclear Information System (INIS)

    In a context that requires the reduction of human impact on the environment, optimizing the recycling of nuclear spent fuel is of increasing importance. The liquid-liquid extraction, one of the main processes of spent fuel recycling, brings together two immiscible phases one of which dispersed into droplets. The mass exchange between both liquids is closely linked to interfacial area produced by the equipment used. Already operated on an industrial scale, the pulsed column is the subject of this work which aims at providing a mathematical model for the prediction of the amount of interfacial area produced so as to allow a better design of devices. The work in this thesis focuses on two main themes: the characterization of emulsions produced by pulsed columns and modelling the dispersed phase behaviour. The characterization step is intended to measure the data required for a better understanding of the emulsion and to calibrate the model. In order to comply with the Eulerian nature of the model, measures were synchronized with the pulsation cycle. Innovative measurement techniques based on image processing and exploiting this synchronization have been developed to assess the average hold-up rate, the drop sizes distribution, the anisotropy and the average interfacial area density. These experimental works have been the subject of an oral presentation at the International Conference on Multi-phase Flows (ICMF 2010). The modelling was based on D. LHUILLIER's work that provides an Eulerian mixture model for the emulsion. The emulsion is perceived as a pseudo-continuous single phase whose properties are weighted by the respective volume fraction of each present phase. The novelty of the model lies on the use of a transport equation for interfacial area density which is the keystone of the design and the assessment of the efficiency of liquid-liquid extraction devices. The evolution of Interfacial area density is the result of the competition between four main phenomena

  17. Chemical precipitation processes for the treatment of low and medium level liquid waste

    International Nuclear Information System (INIS)

    Chemical precipitation processes for the treatment of various radioactive low and medium level liquid waste are described. Application to waste from reprocessing plants, removal of the main gamma emitters, actinide separation, utility liquid wastes generated during pwr operation, and combination of ultrafiltration with chemical precipitation, are all discussed. (U.K.)

  18. Single Bubble and Single Particle Interactions in Liquid Phase

    Czech Academy of Sciences Publication Activity Database

    Zedníková, Mária; Havlica, Jaromír; Růžička, Marek; Drahoš, Jiří

    Bratislava : Slovak Society of Chemical Engineering, 2006 - (Štefuca, V.; Markoš, J.), s. 264 ISBN 80-227-2409-2. [International Conference of Slovak Society of Chemical Engineering /33./. Tatranské Matliare (SK), 22.05.2006-26.05.2006] R&D Projects: GA ČR(CZ) GA104/05/2566; GA ČR(CZ) GP104/05/P554; GA MŠk(CZ) LA 178 Grant ostatní: BEMUSAC(XE) G1MA/CT/2002/04019 Institutional research plan: CEZ:AV0Z40720504 Keywords : bubble-particle collision * flotation * three - phase system Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  19. PWR steam generator chemical cleaning. Phase II. Final report

    International Nuclear Information System (INIS)

    Two techniques believed capable of chemically dissolving the corrosion products in the annuli between tubes and support plates were developed in laboratory work in Phase I of this project and were pilot tested in Indian Point Unit No. 1 steam generators. In Phase II, one of the techniques was shown to be inadequate on an actual sample taken from an Indian Point Unit No. 2 steam generator. The other technique was modified slightly, and it was demonstrated that the tube/support plate annulus could be chemically cleaned effectively

  20. Determination of species activities in organic phase. Modelling of liquid-liquid extraction system using uniquac and unifac models

    International Nuclear Information System (INIS)

    The aim of nuclear fuel reprocessing is to separate reusable elements, uranium and plutonium from the other elements, fission products and minor actinides. PUREX process uses liquid-liquid extraction as separation method. Numerical codes for modelling the extraction operations of PUREX process use a semi-empirical model to represent the partition of species. To improve the precision and precision and predictive nature of the models, we looked for a theoretical tool which permits to quantify medium effects, especially in the organic phase, for which few models are available. The Sergeivskii-Dannus model permits to quantify deviations from ideality in organic phase equilibrated with aqueous phase, but with parameters depending on extractant/diluent ratio. We decided to investigate UNIQUAC and UNIFAC models which permit to estimate activity coefficients in non-electrolytic phases taking account of the mutual interactions of molecules and their morphology. UNIFAC is based on UNIQUAC but molecules are considered as structural groups assemblies. Before applying these model to extraction systems, we investigate their abilities to describe simple systems, binary and ternary systems. UNIQUAC has been applied to TBP/diluent mixtures and permits to estimate activity coefficients for diluents whose interactions with TPB are very different in nature and strength. Group contribution (UNIFAC) applied to TBP/alkane mixtures permits to represent the effect of lengthening alkane chain but not the effect of branching. UNIQUAC fails to describe the TBP/diluent/water/non-extractable-salt systems in case of strong TBP diluent interactions. In order to obtain a correct description of these systems, we used the Chem-UNIFAC model, where the INIFAC equation is supplemented with chemical equilibria allowing explicitly for complexes formation and where group contribution is used to describes complexes. We have with Chem-UNIFAC a model available which can take the effect of the diluent into

  1. Organic molecules modified palladium nanowires arrays prepared by high temperature liquid phase reduction

    Institute of Scientific and Technical Information of China (English)

    Shen Cheng-Min; Yang Tian-Zhong; Xiao Cong-Wen; Zhang Huai-Ruo; Tian Ji-Fa; Bao Li-Hong; Li Chen; Li Jian-Qi; Gao Hong-Jun

    2008-01-01

    This paper reports high temperature liquid phase synthesis of Pd nanowires using chemically modified porous anodic aluminium oxide as template. In this synthesis process, oleic acid is used to modify the inner wall of the pores and Pd2+ complex with oleylamine is filled into the channel of the template. The complex is then reduced to give oleylamine-capped Pd nanowires. This paper suggests that oleic acid can improve the environment of inner wall of the pores, leading to the formation of uniform Pd nanowires. The synthetic process can be extended to make other types of nanowires.

  2. COMMERCIAL-SCALE DEMONSTRATION OF THE LIQUID PHASE METHANOL (LPMEOH) PROCESS

    Energy Technology Data Exchange (ETDEWEB)

    E.C. Heydorn; B.W. Diamond; R.D. Lilly

    2003-06-01

    This project, which was sponsored by the U.S. Department of Energy (DOE) under the Clean Coal Technology Program to demonstrate the production of methanol from coal-derived synthesis gas (syngas), has completed the 69-month operating phase of the program. The purpose of this Final Report for the ''Commercial-Scale Demonstration of the Liquid Phase Methanol (LPMEOH{trademark}) Process'' is to provide the public with details on the performance and economics of the technology. The LPMEOH{trademark} Demonstration Project was a $213.7 million cooperative agreement between the DOE and Air Products Liquid Phase Conversion Company, L.P. (the Partnership). The DOE's cost share was $92,708,370 with the remaining funds coming from the Partnership. The LPMEOH{trademark} demonstration unit is located at the Eastman Chemical Company (Eastman) chemicals-from-coal complex in Kingsport, Tennessee. The technology was the product of a cooperative development effort by Air Products and Chemicals, Inc. (Air Products) and DOE in a program that started in 1981. Developed to enhance electric power generation using integrated gasification combined cycle (IGCC) technology, the LPMEOH{trademark} Process is ideally suited for directly processing gases produced by modern coal gasifiers. Originally tested at the Alternative Fuels Development Unit (AFDU), a small, DOE-owned process development facility in LaPorte, Texas, the technology provides several improvements essential for the economic coproduction of methanol and electricity directly from gasified coal. This liquid phase process suspends fine catalyst particles in an inert liquid, forming a slurry. The slurry dissipates the heat of the chemical reaction away from the catalyst surface, protecting the catalyst, and allowing the methanol synthesis reaction to proceed at higher rates. The LPMEOH{trademark} Demonstration Project accomplished the objectives set out in the Cooperative Agreement with DOE for this Clean

  3. Growth Kinetics of Intracellular RNA/Protein Droplets: Signature of a Liquid-Liquid Phase Transition?

    Science.gov (United States)

    Berry, Joel; Weber, Stephanie C.; Vaidya, Nilesh; Zhu, Lian; Haataja, Mikko; Brangwynne, Clifford P.

    2015-03-01

    Nonmembrane-bound organelles are functional, dynamic assemblies of RNA and/or protein that can self-assemble and disassemble within the cytoplasm or nucleoplasm. The possibility that underlying intracellular phase transitions may drive and mediate the morphological evolution of some membrane-less organelles has been supported by several recent studies. In this talk, results from a collaborative experimental-theoretical study of the growth and dissolution kinetics of nucleoli and extranucleolar droplets (ENDs) in C. elegans embryos will be presented. We have employed Flory-Huggins solution theory, reaction-diffusion kinetics, and quantitative statistical dynamic scaling analysis to characterize the specific growth mechanisms at work. Our findings indicate that both in vivo and in vitro droplet scaling and growth kinetics are consistent with those resulting from an equilibrium liquid-liquid phase transition mediated by passive nonequilibrium growth mechanisms - simultaneous Brownian coalescence and Ostwald ripening. This supports a view in which cells can employ phase transitions to drive structural organization, while utilizing active processes, such as local transcriptional activity, to fine tune the kinetics of these phase transitions in response to given conditions.

  4. 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.

  5. Density functional theory of gas–liquid phase separation in dilute binary mixtures

    Science.gov (United States)

    Okamoto, Ryuichi; Onuki, Akira

    2016-06-01

    We examine statics and dynamics of phase-separated states of dilute binary mixtures using density functional theory. In our systems, the difference of the solvation chemical potential between liquid and gas Δ {μ\\text{s}} (the Gibbs energy of transfer) is considerably larger than the thermal energy {{k}\\text{B}}T for each solute particle and the attractive interaction among the solute particles is weaker than that among the solvent particles. In these conditions, the saturated vapor pressure increases by {{k}\\text{B}}Tn2\\ell\\exp ≤ft(Δ {μ\\text{s}}/{{k}\\text{B}}T\\right) , where n2\\ell is the solute density added in liquid. For \\exp ≤ft(Δ {μ\\text{s}}/{{k}\\text{B}}T\\right)\\gg 1 , phase separation is induced at low solute densities in liquid and the new phase remains in gaseous states, even when the liquid pressure is outside the coexistence curve of the solvent. This explains the widely observed formation of stable nanobubbles in ambient water with a dissolved gas. We calculate the density and stress profiles across planar and spherical interfaces, where the surface tension decreases with increasing interfacial solute adsorption. We realize stable solute-rich bubbles with radius about 30 nm, which minimize the free energy functional. We then study dynamics around such a bubble after a decompression of the surrounding liquid, where the bubble undergoes a damped oscillation. In addition, we present some exact and approximate expressions for the surface tension and the interfacial stress tensor.

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

    International Nuclear Information System (INIS)

    Fusion reactors are our hope for a clean nuclear energy. But as they shall handle huge amounts of tritium, 1.5 1019 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

  7. [Isolation of chemical constituents from Ziziphora clinopodioides Lam. with recycling preparative high performance liquid chromatography].

    Science.gov (United States)

    Li, Guozhu; Meng, Qingyan; Luo, Bi; Ge, Zhenghong; Liu, Wenjie

    2015-01-01

    The combination of alternate recycling and direct recycling preparative liquid chromatography method was developed for the isolation of chemical constituents from Ziziphora clinopodioides Lam. The crude extract was obtained from Ziziphora clinopodioides Lam. by solvent extraction, column chromatography and reversed-phase (RP) flash chromatography. All the separations were performed with methanol and water as mobile phases and the developed recycling preparative method was used with twin RP columns switched by a two-position ten-way valve for the separation. The mobile phase was recycled in close loop with a two-position six-way valve. The fraction I and fraction II from reversed-phase flash chromatography were selected for the demonstration of separation power of the proposed protocol, and five compounds were obtained from Ziziphora clinopodioides Lam. The isolated five compounds were identified as pinocembrin-7-O-rutinoside, pinocembrin-7-O-rutinoside, acacetin-7-O-rutinoside, picein and protocatechuic acid with nuclear magnetic resonance (NMR). The experimental results showed that the developed preparation method exhibited higher separation efficiency with less mobile phase used than the reported methods, and could be expected as an effective method for the separation of complex natural products, especially the compounds with similar structures. PMID:25958674

  8. Searching for dark matter with single phase liquid argon

    Science.gov (United States)

    Caldwell, Thomas S., Jr.

    The first hint that we fail to understand the nature of a large fraction of the gravitating matter in the universe came from Fritz Zwicky's measurements of the velocity distribution of the Coma cluster in 1933. Using the Virial theorem, Zwicky found that galaxies in the cluster were orbiting far too fast to remain gravitationally bound when their mass was estimated by the brightness of the visible matter. This led to the postulation that some form of non-luminous dark matter is present in galaxies comprising a large fraction of the galactic mass. The nature of this dark matter remains yet unknown over 80 years after Zwicky's measurements despite the efforts of many experiments. Dark matter is widely believed to be a beyond the Standard Model particle which brings the dark matter problem into the realm of particle physics. Supersymmetry is one widely explored extension of the Standard model, from which particles meeting the constraints on dark matter properties can naturally arise. These particles are generically termed weakly interacting massive particles (WIMPs), and are a currently favored dark matter candidate. A variety of experimental efforts are underway aimed towards direct detection of dark matter through observation of rare scattering of WIMPs in terrestrial detectors. Single phase liquid argon detectors are an appealing WIMP detection technique due to the scintillation properties of liquid argon and the scalability of the single phase approach. The MiniCLEAN dark matter detector is a single phase liquid argon scintillation scintillation detector with a 500 kg active mass. The modular design offers 4pi coverage with 92 optical cassettes, each containing TPB coated acrylic and a cryogenic photomultiplier tube. The MiniCLEAN detector has recently completed construction at SNOLAB. The detector is currently being commissioned, and will soon begin operation with the liquid argon target. Utilizing advanced pulse-shape discrimination techniques, MiniCLEAN will

  9. Static and dynamical inhomogeneity at liquid - liquid phase transition of Se-Te mixtures

    Directory of Open Access Journals (Sweden)

    Ishikawa D.

    2011-05-01

    Full Text Available We have carried out x-ray transmission and small-angle x-ray scattering (SAXS measurements of liquid Se70-Te30 mixture up to 1000 °C and 100MPa and inelastic x-ray scattering (IXS measurement of liquid Se50-Te50 mixture at SPring-8 in Japan. In this paper, we report the preliminary results. In liquid Se70Te30 at 6MPa, with increasing temperature from 400 °C, the density first normaly decreases but anomalously increases from 650 °C. This anomalous density behaviour can be interpreted that the sample exhibits continuous transition from low-density phase to high-density one in this temperature region. As a proof of that, the zero-wavenumber-limit of SAXS intensity I(0 increases and shows maximum in this region, which means that the static density inhomogeneity arises due to phase transition. When the pressure is elevated, the density and I(0 curves shift to lower temperature side. The velocity of acoustic mode in Se50-Te50 estimated by IXS data is much higher than the ultrasonic sound velocity (so-called "fast sound" state and the temperature dependences of the two velocities are totally different. But the ratio of the two velocities, the strength of "fast sound", seems to increase with approaching to the transition region and thus it seems to be a good sign of dynamical inhomogeneity.

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

    Science.gov (United States)

    Lima, Thamires A.; Paschoal, Vitor H.; Faria, Luiz F. O.; Ribeiro, Mauro C. C.; Ferreira, Fabio F.; Costa, Fanny N.; Giles, Carlos

    2016-06-01

    Phase transitions of the ionic liquids n-butyl-trimethylammonium bis(trifluoromethanesulfonyl)imide, [N1114][NTf2], and methyl-tributylammonium bis(trifluoromethanesulfonyl)imide, [N1444][NTf2], 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). [N1444][NTf2] experiences glass transition at low temperature, whereas [N1114][NTf2] 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.

  11. Spin liquid phases of large spin Mott insulating ultracold atoms

    Science.gov (United States)

    Rutkowski, Todd C.; Lawler, Michael J.

    2015-03-01

    Understanding exotic forms of magnetism, primarily those driven by large spin fluctuations such as the quantum spin liquid state, is a major goal of condensed matter physics. But, the relatively small number of viable candidate materials poses a difficulty. We believe this problem can be solved by Mott insulating ultracold atoms with large spin moments that interact via whole-atom exchange. The large spin fluctuations of this exchange could stabilize exotic physics similar to condensed matter systems, all in an extremely tunable environment. We have approached the problem by performing a mean field theory for spin-f bosons in an optical lattice which is exact in the large-f limit. This setting is similar to that of SU(N) magnetism proposed for alkali-earth atoms but without the SU(N) symmetry. We find that states with long-range order, such as the spin nematic phase of f = 1 Na atoms, become highly entangled spin-liquid-like states for f = 3 Cr atoms. This is evidence that the magnetic phase diagram for Mott insulating atoms at larger spins generically contains exotic forms of magnetism.

  12. Vapor-liquid (VLE) and liquid-liquid (LLE) phase equilibria calculations for polystyrene plus methyleyclohexane and polystyrene plus cyclohexane solutions

    DEFF Research Database (Denmark)

    Wilczura-Wachnik, H.; Jonsdottir, Svava Osk

    2006-01-01

    This paper presents the vapor-liquid (VLE) and liquid-liquid (LLE) phase equilibria predictions for polystyrene in two theta solvents: cyclohexane and methylcyclohexane. VLE calculations were performed with the Elbro free volume method and a modified version of the PC-SAFT method, as well as with...

  13. Polyethylene Glycol as Support and Phase Transfer Catalyst in Aqueous Palladium-catalyzed Liquid-phase Synthesis

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Excellent yields and purity were obtained in the aqueous medium Suzuki, Sonogashira, Stille and Heck reactions using palladium (Ⅱ) as catalyst in liquid phase synthesis. Polyethylene glycol (PEG) acted as soluble polymeric support and phase transfer catalyst as well.

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

    International Nuclear Information System (INIS)

    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. Liquid mixture convection during phase separation in a temperature gradient

    Science.gov (United States)

    Lamorgese, A. G.; Mauri, R.

    2011-03-01

    We simulate the phase separation of a low-viscosity binary mixture, assuming that the fluid system is confined between two walls that are cooled down to different temperatures below the critical point of the mixture, corresponding to quenches within the unstable range of its phase diagram. Spinodal decomposition patterns for off-critical mixtures are studied numerically in two dimensions in the creeping flow limit and for a large Lewis number, together with their dependence on the fluidity coefficient. Our numerical results reproduce the large-scale unidirectional migration of phase-separating droplets that was observed experimentally by Califano et al. ["Large-scale, unidirectional convection during phase separation of a density-matched liquid mixture," Phys. Fluids 17, 094109 (2005)], who measured typical speeds that are quite larger than the Marangoni velocity. To understand this finding, we then studied the temperature-gradient-induced motion of an isolated droplet of the minority phase embedded in a continuous phase, showing that when the drop is near local equilibrium, its speed is of the same order as the Marangoni velocity, i.e., it is proportional to the unperturbed temperature gradient and the fluidity coefficient. However, far from local equilibrium, i.e., for very large unperturbed temperature gradients, the drop first accelerates to a speed that is larger than the Marangoni velocity, then, later, it decelerates, exhibiting an increase-decrease behavior, as described by Yin et al. ["Thermocapillary migration of nondeformable drops," Phys. Fluids 20, 082101 (2008)]. Such behavior is due to the large nonequilibrium, Korteweg-driven convection, which at first accelerates the droplets to relatively large velocities, and then tends to induce an approximately uniform inside temperature distribution so that the drop experiences an effective temperature gradient that is much smaller than the unperturbed one and, consequently, decelerates.

  16. Summer Research Institute Interfacial and Condensed Phase Chemical Physics

    Energy Technology Data Exchange (ETDEWEB)

    Barlow, Stephan E.

    2004-10-01

    Pacific Northwest National Laboratory (PNNL) hosted its first annual Summer Research Institute in Interfacial and Condensed Phase Chemical Physics from May through September 2004. During this period, fourteen PNNL scientists hosted sixteen young scientists from eleven different universities. Of the sixteen participants, fourteen were graduate students; one was transitioning to graduate school; and one was a university faculty member.

  17. Digital holographic measurement of liquid-liquid two-phase flows

    International Nuclear Information System (INIS)

    A direct application of digital in-line holography to liquid droplets dispersed in a continuous liquid phase is described. The droplet size imposes a regime of intermediate-field diffraction that has been little explored to date. Acquired diffraction patterns show that the usual opaque disk model is not valid and that good agreement is obtained with a thin lens model. Hologram focusing is nevertheless performed with a dedicated automated method that slightly outperforms Royer criteria. A literature review has been conducted to identify the sharpest auto-focus function for our application. Droplet paths are retrieved in three dimensions simultaneously with their velocity and diameter. The developed experimental setup is a first step toward implementation of the method in more complex configurations, including pulsed flows. (authors)

  18. 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.

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

    International Nuclear Information System (INIS)

    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

  20. Liquid/liquid metal extraction: Phase diagram topology resulting from molecular interactions between extractant, ion, oil and water

    International Nuclear Information System (INIS)

    We consider the class of surfactants called 'extractants' since they specifically interact with some cations and are used in liquid-liquid separation processes. We review here features of water-poor reverse micelles in water/oil/extractant systems as determined by combined structural studies including small angle scattering techniques on absolute scale. Origins of instabilities, liquid-liquid separation as well as emulsification failure are detected. Phase diagrams contain the same multi-phase domains as classical microemulsions, but special unusual features appear due to the high spontaneous curvature directed towards the polar cores of aggregates as well as rigidity of the film made by extracting molecules. (authors)

  1. Liquid/liquid metal extraction: Phase diagram topology resulting from molecular interactions between extractant, ion, oil and water

    Science.gov (United States)

    Bauer, C.; Bauduin, P.; Dufrêche, J. F.; Zemb, T.; Diat, O.

    2012-11-01

    We consider the class of surfactants called "extractants" since they specifically interact with some cations and are used in liquid-liquid separation processes. We review here features of water-poor reverse micelles in water/oil/ extractant systems as determined by combined structural studies including small angle scattering techniques on absolute scale. Origins of instabilities, liquid-liquid separation as well as emulsification failure are detected. Phase diagrams contain the same multi-phase domains as classical microemulsions, but special unusual features appear due to the high spontaneous curvature directed towards the polar cores of aggregates as well as rigidity of the film made by extracting molecules.

  2. Chemically Induced Phase Transformation in Austenite by Focused Ion Beam

    Science.gov (United States)

    Basa, Adina; Thaulow, Christian; Barnoush, Afrooz

    2013-11-01

    A highly stable austenite phase in a super duplex stainless steel was subjected to a combination of different gallium ion doses at different acceleration voltages. It was shown that contrary to what is expected, an austenite to ferrite phase transformation occurred within the focused ion beam (FIB) milled regions. Chemical analysis of the FIB milled region proved that the gallium implantation preceded the FIB milling. High resolution electron backscatter diffraction analysis also showed that the phase transformation was not followed by the typical shear and plastic deformation expected from the martensitic transformation. On the basis of these observations, it was concluded that the change in the chemical composition of the austenite and the local increase in gallium, which is a ferrite stabilizer, results in the local selective transformation of austenite to ferrite.

  3. 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.; Fehrmann, Rasmus

    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-but...

  4. For Noble Gases, Energy is Positive for the Gas Phase, Negative for the Liquid Phase

    CERN Document Server

    Asanuma, Nobu-Hiko

    2016-01-01

    We found from experimental data that for noble gases and H$_2$, the energy is positive for the gas phase, and negative for the liquid, possibly except the small vicinity of the critical point, about $(1- T/T_c) \\le 0.005$. The line $E=E_c$, in the supercritical region is found to lie close to the Widom line, where $E_c$ is the critical energy.

  5. Method for forming single phase, single crystalline 2122 BCSCO superconductor thin films by liquid phase epitaxy

    Science.gov (United States)

    Pandey, Raghvendra K. (Inventor); Raina, Kanwal (Inventor); Solayappan, Narayanan (Inventor)

    1994-01-01

    A substantially single phase, single crystalline, highly epitaxial film of Bi.sub.2 CaSr.sub.2 Cu.sub.2 O.sub.8 superconductor which has a T.sub.c (zero resistance) of 83 K is provided on a lattice-matched substrate with no intergrowth. This film is produced by a Liquid Phase Epitaxy method which includes the steps of forming a dilute supercooled molten solution of a single phase superconducting mixture of oxides of Bi, Ca, Sr, and Cu having an atomic ratio of about 2:1:2:2 in a nonreactive flux such as KCl, introducing the substrate, e.g., NdGaO.sub.3, into the molten solution at 850.degree. C., cooling the solution from 850.degree. C. to 830.degree. C. to grow the film and rapidly cooling the substrate to room temperature to maintain the desired single phase, single crystalline film structure.

  6. The Frozen State in the Liquid Phase of Side-Chain Liquid-Crystal Polymers

    International Nuclear Information System (INIS)

    Quenched isotropic melts of side-chain liquid-crystal polymers reveal surprisingly an anisotropic polymer conformation. This small-angle neutron-scattering (SANS) result is consistent with the identification of a macroscopic, solidlike response in the isotropic phase. Both experiments (rheology and SANS) indicate that the polymer system appears frozen on millimeter length scales and at the time scales of the observation. This result implies that the flow behavior is not the terminal behavior and that cross-links or entanglements are not a necessary condition to provide elasticity in melts

  7. Surface Confined Ionic Liquid-A New Stationary Phase for the Separation of Ephedrines in High-performance Liquid Chromatography

    Institute of Scientific and Technical Information of China (English)

    Shu Juan LIU; Feng ZHOU; Xiao Hua XIAO; Liang ZHAO; Xia LIU; Sheng Xiang JIANG

    2004-01-01

    In this article, a new and effective stationary phase based on ionic liquid modified silica is first reported and used for the separation of ephedrines in high-performance liquid chromatography (HPLC). The separation results indicate the high efficiency and reproducibility of the stationary phase. The electrostatic interaction, ion-exchange interaction between the solutes and the stationary phase are considered to attribute the effective separation. Moreover, the free silanols on the surface of the silica are effectively masked by the immobilized ionic liquid, a result of which is to decrease the non-specific absorption.

  8. The initial phase of sudden releases of superheated liquid

    International Nuclear Information System (INIS)

    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

  9. Oscillating Frequency Response of a Langasite Crystal Microbalance in Liquid Phase

    Institute of Scientific and Technical Information of China (English)

    Qi KANG; Huai Jin ZHANG; Xue Yong LIU; Da Zhong SHEN

    2005-01-01

    The frequency responses of a langasite crystal microbalance (LCM) in liquid phase were investigated. It was shown that the LCM possessed much stronger oscillating ability in liquid phase than that of the commonly used quartz crystal microbalance (QCM). The frequency shifts of the LCM to the changes in mass loading, as well as viscosity and density of the liquid were measured. The LCM was applied to monitor the adsorption process of an ionic liquid film to ethanol vapor.

  10. Mixing-Demixing Phase Diagram for Simple Liquids in Non-Uniform Electric Fields

    OpenAIRE

    Galanis, Jennifer; Tsori, Yoav

    2013-01-01

    We deduce the mixing-demixing phase diagram for binary liquid mixtures in an electric field for various electrode geometries and arbitrary constitutive relation for the dielectric constant. By focusing on the behavior of the liquid-liquid interface, we produce simple analytic expressions for the dependence of the interface location on experimental parameters. We also show that the phase diagram contains regions where liquid separation cannot occur under any applied field. The analytic express...

  11. Computer study of liquid phase sintering - three-dimensional time dependent rearrangement

    Energy Technology Data Exchange (ETDEWEB)

    Nikolic, Zoran S [University of Nish, Faculty of Electronic Engineering, Department of Microelectronics, 18000 Nish, PO Box 73 (Serbia); Wakai, Fumihiro, E-mail: zoran.nikolic@elfak.ni.ac.rs [Secure Materials Center, Materials and Structures Laboratory, Tokyo Institute of Technology, R3-23 4259 Nagatsuta, Midori, Yokohama, 226-8503 (Japan)

    2011-03-15

    The rearrangement process during liquid phase sintering has been generally accepted that driven by the capillary forces between solid grains embedded in liquid. This paper outlines a computer-based method for three-dimensional computer simulation of rearrangement during liquid phase sintering. The theoretical models dealing with the fundamental interaction forces that exist between grains attached by liquid bridges will be outlined and the development from these pair-wise interactions to multi-grain models will be described.

  12. Lectures on holographic non-Fermi liquids and quantum phase transitions

    CERN Document Server

    Iqbal, Nabil; Mezei, Márk

    2011-01-01

    In these lecture notes we review some recent attempts at searching for non-Fermi liquids and novel quantum phase transitions in holographic systems using gauge/gravity duality. We do this by studying the simplest finite density system arising from the duality, obtained by turning on a nonzero chemical potential for a U(1) global symmetry of a CFT, and described on the gravity side by a charged black hole. We address the following questions of such a finite density system: 1. Does the system have a Fermi surface? What are the properties of low energy excitations near the Fermi surface? 2. Does the system have an instability to condensation of scalar operators? What is the critical behavior near the corresponding quantum critical point? We find interesting parallels with those of high T_c cuprates and heavy electron systems. Playing a crucial role in our discussion is a universal intermediate-energy phase, called a "semi-local quantum liquid", which underlies the non-Fermi liquid and novel quantum critical beha...

  13. Liquid Phase – Pulsed Laser Ablation: A route to fabricate different carbon nanostructures

    International Nuclear Information System (INIS)

    Carbon nanostructures in various forms and sizes, and with different speciation properties have been prepared from graphite by Liquid Phase – Pulsed Laser Ablation (LP-PLA) using a high frequency Nd:YAG laser. High energy densities and pulse repetition frequencies of up to 10 kHz were used in this ablation process to produce carbon nanomaterials with unique chemical structures. Dynamic Light Scattering (DLS), micro-Raman and High-Resolution Transmission Electron Microscopy (HRTEM) were used to confirm the size distribution, morphology, chemical bonding, and crystallinity of these nanostructures. This article demonstrates how the fabrication process affects measured characteristics of the produced carbon nanomaterials. The obtained particle properties have potential use for various applications including biochemical speciation applications.

  14. Liquid Phase – Pulsed Laser Ablation: A route to fabricate different carbon nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Al-Hamaoy, Ahmed [Advanced Processing Technology Research Centre, Dublin City University, Dublin 9 (Ireland); Institute of Laser for Postgraduate Studies, University of Baghdad (Iraq); Mechanical Engineering Department, College of Engineering, University of Anbar (Iraq); Chikarakara, Evans [Advanced Processing Technology Research Centre, Dublin City University, Dublin 9 (Ireland); Jawad, Hussein [Institute of Laser for Postgraduate Studies, University of Baghdad (Iraq); Gupta, Kapil; Kumar, Dinesh; Rao, M.S. Ramachandra [Department of Physics, Nano Functional Materials Technology Centre and Materials Science Research Centre, Indian Institute of Technology (IIT) Madras, Chennai 600 036 (India); Krishnamurthy, Satheesh [Materials Engineering, The Open University, Milton Keynes, MK7 6AA (United Kingdom); Morshed, Muhammad [Advanced Processing Technology Research Centre, Dublin City University, Dublin 9 (Ireland); Fox, Eoin; Brougham, Dermot [School of Chemical Sciences, Dublin City University, Dublin 9 (Ireland); He, Xiaoyun; Vázquez, Mercedes [Advanced Processing Technology Research Centre, Dublin City University, Dublin 9 (Ireland); Irish Separation Science Cluster (ISSC) National Centre for Sensor Research, Dublin City University, Dublin 9 (Ireland); Brabazon, Dermot, E-mail: dermot.brabazon@dcu.ie [Advanced Processing Technology Research Centre, Dublin City University, Dublin 9 (Ireland); Irish Separation Science Cluster (ISSC) National Centre for Sensor Research, Dublin City University, Dublin 9 (Ireland)

    2014-05-01

    Carbon nanostructures in various forms and sizes, and with different speciation properties have been prepared from graphite by Liquid Phase – Pulsed Laser Ablation (LP-PLA) using a high frequency Nd:YAG laser. High energy densities and pulse repetition frequencies of up to 10 kHz were used in this ablation process to produce carbon nanomaterials with unique chemical structures. Dynamic Light Scattering (DLS), micro-Raman and High-Resolution Transmission Electron Microscopy (HRTEM) were used to confirm the size distribution, morphology, chemical bonding, and crystallinity of these nanostructures. This article demonstrates how the fabrication process affects measured characteristics of the produced carbon nanomaterials. The obtained particle properties have potential use for various applications including biochemical speciation applications.

  15. 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.

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

    International Nuclear Information System (INIS)

    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

  17. Liquid-phase-deposited barium titanate thin films on silicon

    International Nuclear Information System (INIS)

    Using a mixture of hexafluorotitanic acid, barium nitrate and boric acid, high refractive index (1.54) barium titanate films can be deposited on silicon substrates. The deposited barium titanate films have featureless surfaces. The deposition temperature is near room temperature (800C). However, there are many fluorine and silicon incorporations in the films. The refractive index of the as-deposited film is 1.54. By current-voltage measurement, the leakage current of the as-deposited film with a thickness of 1000 A is about 9.48x10-7 A cm-2 at the electrical field intensity of 0.3 MV cm-1. By capacitance-voltage measurement, the effective oxide charge of the liquid-phase-deposited barium titanate film is 3.06x1011 cm-2 and the static dielectric constant is about 22. (author)

  18. Liquid-phase synthesized mesoporous electrochemical supercapacitors of nickel hydroxide

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Jinho; Park, Mira; Ham, Dukho; Mane, Rajaram S.; Han, Sung-Hwan [Inorganic Nano-Materials Laboratory, Department of Chemistry, Hanyang University, Sungdong-Ku, Haengdang-dong 17, Seoul 133-791 (Korea); Ogale, S.B. [Physical and Materials Chemsitry Division, National Chemical Laboratory, Dr. Homi Bhabha Road, Pashan, Pune 411008 (India)

    2008-06-01

    Electrochemical supercapacitive (ES) properties of liquid-phase synthesized mesoporous (pore size distribution centered {proportional_to}12 nm) and of 120 m{sup 2}/g surface area nickel hydroxide film electrodes onto tin-doped indium oxide substrate are discussed. The amounts of inner and outer charges are calculated to investigate the contribution of mesoporous structure on charge storage where relatively higher contribution of inner charge infers good ion diffusion into matrix of nickel hydroxide. Effect of different electrolytes, electrolyte concentrations, deposit mass and scan rates on the current-voltage profile in terms of the shape and enclosed area is investigated. Specific capacitance of {proportional_to}85 F/g at a constant current density of 0.03 A/g is obtained from the discharge curve. (author)

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

    International Nuclear Information System (INIS)

    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

  20. Analysis of two-phase liquid metal MHD induction converter

    International Nuclear Information System (INIS)

    An analysis is made on the performance characteristics of a liquid-metal MHD induction converter with liquid-gas two-phase mixture as working fluid. The equivalent electrical conductivity and the velocity vary along the generator channel in this kind of induction converter. Two important parameters which represent the variations of the equivalent electrical conductivity and the velocity respectively are defined. With these parameters the induction equation is analytically solved with the perturbation technique. Quantities representing generator performance, such as power densities and generator efficiency, are obtained from the perturbed magnetic field and the parameters mentioned above. Suitable combination of values for these parameters will tend to let the effects brought by the variations of electrical conductivity and of velocity cancel each other, and the relation between these parameters is analytically derived that assures the non-perturbation of the magnetic field and of the gross output power density. In this condition of non-perturbation, the generator efficiency approaches that for the unperturbed case when the velocity variation and the inlet slip ratio are small. (auth.)

  1. Non-aqueous phase liquid spreading during soil vapor extraction

    Science.gov (United States)

    Kneafsey, Timothy J.; Hunt, James R.

    2004-02-01

    Many non-aqueous phase liquids (NAPLs) are expected to spread at the air-water interface, particularly under non-equilibrium conditions. In the vadose zone, this spreading should increase the surface area for mass transfer and the efficiency of volatile NAPL recovery by soil vapor extraction (SVE). Observations of spreading on water wet surfaces led to a conceptual model of oil spreading vertically above a NAPL pool in the vadose zone. Analysis of this model predicts that spreading can enhance the SVE contaminant recovery compared to conditions where the liquid does not spread. Experiments were conducted with spreading volatile oils hexane and heptane in wet porous media and capillary tubes, where spreading was observed at the scale of centimeters. Within porous medium columns up to a meter in height containing stagnant gas, spreading was less than ten centimeters and did not contribute significantly to hexane volatilization. Water film thinning and oil film pinning may have prevented significant oil film spreading, and thus did not enhance SVE at the scale of a meter. The experiments performed indicate that volatile oil spreading at the field scale is unlikely to contribute significantly to the efficiency of SVE.

  2. Transient evaporation and stratification of two immiscible liquids for LMFBR transition phase analysis

    International Nuclear Information System (INIS)

    Two immiscible liquids at different temperatures are suddenly brought together inside a rectangular box. The colder liquid evaporates upon contact of the hotter, less volatile liquid. Fast thermal equilibrium is achieved by vapor-generated mixing of the fluids. The denser, less volatile liquid finally stratifies below the remaining liquid phase of the more volatile fluid. This report describes the experimental apparatus of the Multiphase Multicomponent Box (MMB) experiment, and presents the experimental results of seven tests. The results may shed some light on the fundamental thermal hydraulics of the transition phase during beyond-design accidents in liquid metal fast breeder reactors (LMFBR). (orig.)

  3. Phase diagram of the Dirac spectrum at nonzero chemical potential

    International Nuclear Information System (INIS)

    The Dirac spectrum of QCD with dynamical fermions at nonzero chemical potential is characterized by three regions: a region with a constant eigenvalue density, a region where the eigenvalue density shows oscillations that grow exponentially with the volume and the remainder of the complex plane where the eigenvalue density is zero. In this paper we derive the phase diagram of the Dirac spectrum from a chiral Lagrangian. We show that the constant eigenvalue density corresponds to a pion condensed phase while the strongly oscillating region is given by a kaon condensed phase. The normal phase with nonzero chiral condensate but vanishing Bose condensates coincides with the region of the complex plane where there are no eigenvalues.

  4. Sensitive and fast mutation detection by solid phase chemical cleavage

    DEFF Research Database (Denmark)

    Hansen, Lise Lotte; Justesen, Just; Kruse, Torben A

    1996-01-01

    We have developed a solid phase chemical cleavage method (SpCCM) for screening large DNA fragments for mutations. All reactions can be carried out in microtiterwells from the first amplification of the patient (or test) DNA through the search for mutations. The reaction time is significantly...... reduced compared to the conventional chemical cleavage method (CCM), and even by using a uniformly labelled probe, the exact position and nature of the mutation can be revealed. The SpCCM is suitable for automatization using a workstation to carry out the reactions and a fluorescent detection-based DNA...

  5. Low Density Phases in a Uniformly Charged Liquid

    Science.gov (United States)

    Knüpfer, Hans; Muratov, Cyrill B.; Novaga, Matteo

    2016-07-01

    This paper is concerned with the macroscopic behavior of global energy minimizers in the three-dimensional sharp interface unscreened Ohta-Kawasaki model of diblock copolymer melts. This model is also referred to as the nuclear liquid drop model in the studies of the structure of highly compressed nuclear matter found in the crust of neutron stars, and, more broadly, is a paradigm for energy-driven pattern forming systems in which spatial order arises as a result of the competition of short-range attractive and long-range repulsive forces. Here we investigate the large volume behavior of minimizers in the low volume fraction regime, in which one expects the formation of a periodic lattice of small droplets of the minority phase in a sea of the majority phase. Under periodic boundary conditions, we prove that the considered energy {Γ}-converges to an energy functional of the limit "homogenized" measure associated with the minority phase consisting of a local linear term and a non-local quadratic term mediated by the Coulomb kernel. As a consequence, asymptotically the mass of the minority phase in a minimizer spreads uniformly across the domain. Similarly, the energy spreads uniformly across the domain as well, with the limit energy density minimizing the energy of a single droplet per unit volume. Finally, we prove that in the macroscopic limit the connected components of the minimizers have volumes and diameters that are bounded above and below by universal constants, and that most of them converge to the minimizers of the energy divided by volume for the whole space problem.

  6. Chemical recycling of municipal waste slag by using phase separation

    OpenAIRE

    Nanba, Tokuro; Kuroda, Yutaro; Sakida, Shinichi; Benino, Yasuhiko

    2009-01-01

    A chemical recycling method by using phase separation was applied to municipal waste slags. Glasses were prepared from incineration ash and ash-melted slag, where B(2)O(3) was added to promote phase separation. The glasses were heat-treated at temperatures higher than their glass transition temperatures, and they were soaked in hydrochloric acid, leaching CaO, Fe(2)O(3), K(2)O, and S. Transparent and colorless solids containing ca. 80 mass% of SiO(2) were successfully obtained as residues. It...

  7. Synthesis of silicon carbide nanowires by solid phase source chemical vapor deposition

    Institute of Scientific and Technical Information of China (English)

    NI Jie; LI Zhengcao; ZHANG Zhengjun

    2007-01-01

    In this paper,we report a simple approach to synthesize silicon carbide(SiC)nanowires by solid phase source chemical vapor deposition(CVD) at relatively low temperatures.3C-SiC nanowires covered by an amorphous shell were obtained on a thin film which was first deposited on silicon substrates,and the nanowires are 20-80 am in diameter and several μm in length,with a growth direction of[200].The growth of the nanowires agrees well on vapor-liquid-solid (VLS)process and the film deposited on the substrates plays an important role in the formation of nanowires.

  8. Effect of heat and film thickness on a photoinduced phase transition in azobenzene liquid crystalline polyesters

    DEFF Research Database (Denmark)

    Sanchez, C; Alcala, R; Hvilsted, Søren;

    2003-01-01

    The liquid crystal to isotropic phase transition induced with 488 nm light in films of liquid crystalline azobenzene polyesters has been studied as a function of temperature, light intensity, and film thickness. That phase transition is associated with the photoinduced trans-cis-trans isomerizati......The liquid crystal to isotropic phase transition induced with 488 nm light in films of liquid crystalline azobenzene polyesters has been studied as a function of temperature, light intensity, and film thickness. That phase transition is associated with the photoinduced trans...

  9. Synthesis of tungsten oxide thin film by liquid phase deposition

    International Nuclear Information System (INIS)

    High purity and well crystallized tungsten acid hydrates (H2WO4.H2O) thin films were prepared from H2WO4-HF(aq.) and H3BO3 as precursors by the liquid phase deposition method. The crystal structure was indexed as monoclinic with unit cell lattice constants a = 7.517 A, b = 6.907 A, c = 3.694 A and β = 89.58 deg. The monoclinic phase was transformed into orthorhombic WO3.H2O after heating at 100 deg. C. Further heating from 300 to 500 deg. C resulted in an anhydrous monoclinic WO3 films. The effects of the composition and the reaction time on the deposition and the microstructures of the deposited films were studied by the means of scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The film formation showed strong dependence upon the composition, whereas the amount of deposition, the shape and the films thickness could be controlled by the reaction time. Cross-sectional TEM image of WO3 film deposited on Au wire indicated that the epitaxial growth of the film was maintained after calcination at 500 deg. C. XPS analysis also revealed the existence of W6+ ions in both the deposited and calcined films.

  10. Tertiary phase diagram of cellulose, ionic liquid and organic solvent

    Science.gov (United States)

    Zhang, Xin; Henderson, Doug; Tyagi, Madhusudan; Mao, Yimin; Briber, Robert M.; Wang, Howard

    Cellulose is the most abundant natural polymer on earth, and widely used in products from clothing to paper. Fundamental understanding of molecular solutions of cellulose is the key to realize advanced technologies beyond cellulose fibers. It has been reported that certain ionic liquid/organic solvent mixtures dissolve cellulose. In this study, the tertiary phase diagram of microcrystalline cellulose, 1-Ethyl-3-methylimidazolium acetate (EMIMAc), and dimethylformamide (DMF) mixtures has been determined using optical cloud point method and small angle neutron scattering (SANS). Data indicate that a molar ratio of EMIMAc to cellulose repeating unit equal or greater than 3 is necessary but not sufficient in forming one-phase homogeneous solutions. A miscibility gap exists in the dilute regime, where a minimum of 5 mol% of EMIM Ac in DMF is needed to form homogenous solutions. SANS show that cellulose chains adopt Gaussian-like conformation in homogenous solutions. The solutions exhibit the characteristics of upper critical solution temperature. Clustering of cellulose chains occurs at low EMIMAc/DMF or EMIMAc/cellulose ratio, or at low temperatures. The mechanism of cellulose dissolution in tertiary mixture is discussed.

  11. Reversible Nanoparticle Cubic Lattices in Blue Phase Liquid Crystals.

    Science.gov (United States)

    Gharbi, Mohamed Amine; Manet, Sabine; Lhermitte, Julien; Brown, Sarah; Milette, Jonathan; Toader, Violeta; Sutton, Mark; Reven, Linda

    2016-03-22

    Blue phases (BPs), a distinct class of liquid crystals (LCs) with 3D periodic ordering of double twist cylinders involving orthogonal helical director twists, have been theoretically studied as potential templates for tunable colloidal crystals. Here, we report the spontaneous formation of thermally reversible, cubic crystal nanoparticle (NP) assemblies in BPs. Gold NPs, functionalized to be highly miscible in cyanobiphenyl-based LCs, were dispersed in BP mixtures and characterized by polarized optical microscopy and synchrotron small-angle X-ray scattering (SAXS). The NPs assemble by selectively migrating to periodic strong trapping sites in the BP disclination lines. The NP lattice, remarkably robust given the small particle size (4.5 nm diameter), is commensurate with that of the BP matrix. At the BP I to BP II phase transition, the NP lattice reversibly switches between two different cubic structures. The simultaneous presence of two different symmetries in a single material presents an interesting opportunity to develop novel dynamic optical materials. PMID:26900753

  12. An overview of multidimensional liquid phase separations in food analysis.

    Science.gov (United States)

    Franco, Maraíssa Silva; Padovan, Rodrigo Nogueira; Fumes, Bruno Henrique; Lanças, Fernando Mauro

    2016-07-01

    Food safety is a priority public health concern that demands analytical methods capable to detect low concentration level of contaminants (e.g. pesticides and antibiotics) in different food matrices. Due to the high complexity of these matrices, a sample preparation step is in most cases mandatory to achieve satisfactory results being usually tedious, lengthy, and prone to the introduction of errors. For this reason, many research groups have focused efforts on the development of online systems capable to do the cleanup, concentration, and separation steps at once through multidimensional separation techniques (MDS). Among several possible setups, the most popular are the multidimensional chromatographic techniques (MDC) that consist in combining more than one mobile and/or stationary phase to provide a satisfactory separation. In the present review, we selected a variety of multidimensional separation systems used for food contaminant analysis in order to discuss the instrumentation aspects, the concept of orthogonality, column approaches used in these systems, and new materials that can be used in these columns. Selected classes of contaminants present in food matrices are introduced and discussed as example of the potential applications of multidimensional liquid phase separation techniques in food safety. PMID:27030380

  13. Commercial-Scale Demonstration of the Liquid Phase Methanol (LPMEOTH) Process

    Energy Technology Data Exchange (ETDEWEB)

    None

    1998-12-21

    The Liquid Phase Methanol (LPMEOW) Demonstration Project at Kingsport, Tennessee, is a $213.7 million cooperative agreement between the U.S. Department of Energy (DOE) and Air Products Liquid Phase Conversion Company, L.P. (the Partnership) to produce methanol from coal-derived synthesis gas (syngas). Air Products and Chemicals, Inc. (Air Products) and Eastman Chemical Company (Eastman) formed the Partnership to execute the Demonstration Project. The LPMEOI-P Process Demonstration Unit was built at a site located at the Eastman coal-to-chemicals complex in Kingsport. During this quarter, initial planning and procurement work continued on the seven project sites which have been accepted for participation in the off-site, product-use test program. Approximately 12,000 gallons of fuel-grade methanol (98+ wt% methanol, 4 wt% water) produced during operation on carbon monoxide (CO)-rich syngas at the LPMEOW Demonstration Unit was loaded into trailers and shipped off-site for Mure product-use testing. At one of the projects, three buses have been tested on chemical-grade methanol and on fhel-grade methanol from the LPMEOW Demonstration Project. During the reporting period, planning for a proof-of-concept test run of the Liquid Phase Dimethyl Ether (LPDME~ Process at the Alternative Fuels Development Unit (AFDU) in LaPorte, TX continued. The commercial catalyst manufacturer (Calsicat) has prepared the first batch of dehydration catalyst in large-scale equipment. Air Products will test a sample of this material in the laboratory autoclave. Catalyst activity, as defined by the ratio of the rate constant at any point in time to the rate constant for freshly reduced catalyst (as determined in the laborato~ autoclave), was monitored for the initial extended operation at the lower initial reactor operating temperature of 235oC. At this condition, the decrease in catalyst activity with time from the period 20 December 1997 through 27 January 1998 occurred at a rate of 1.0% per

  14. Steroid monochloroacetates : Physical-chemical characteristics and use in gas-liquid chromatography

    NARCIS (Netherlands)

    Molen, H.J. van der; Groen, D.; Maas, J.H. van der

    1965-01-01

    Synthesis and physical-chemical characteristics (melting points, infrared-, visible- and ultraviolet spectra, paper-,thin-layer- and gas-liquid Chromatographie behaviour) of monochloroacetate derivatives of steroids representing the androstane-, pregnane-, estrane- and cholestane series are describe

  15. Roaming-mediated ultrafast isomerization of geminal tri-bromides in the gas and liquid phases

    Science.gov (United States)

    Mereshchenko, Andrey S.; Butaeva, Evgeniia V.; Borin, Veniamin A.; Eyzips, Anna; Tarnovsky, Alexander N.

    2015-07-01

    ‘Roaming’ is a new and unusual class of reaction mechanism that has recently been discovered in unimolecular dissociation reactions of isolated molecules in the gas phase. It is characterized by frustrated bond cleavage, after which the two incipient fragments ‘roam’ on a flat region of the potential energy surface before reacting with one another. Here, we provide evidence that supports roaming in the liquid phase. We are now able to explain previous solution-phase experiments by comparing them with new ultrafast transient absorption data showing the photoisomerization of gas-phase CHBr3. We see that, upon S0-S1 excitation, gas-phase CHBr3 isomerizes within 100 fs into the BrHCBr-Br species, which is identical to what has been observed in solution. Similar sub-100 fs isomerization is now also observed for BBr3 and PBr3 in solution upon S1 excitation. Quantum chemical simulations of XBr3 (X = B, P or CH) suggest that photochemical reactivity in all three cases studied is governed by S1/S0 conical intersections and can best be described as occurring through roaming-mediated pathways.

  16. Gas-Liquid Interfacial Area, Bubble Size and Liquid-Phase Mass Transfer Coefficient in a Three-Phase External Loop Airlift Bubble Column

    OpenAIRE

    Yoshimoto, M; Suenaga, S.; Furumoto, K.; Fukunaga, K.; Nakao, Katsumi

    2007-01-01

    The interfacial area a was measured by the sulfite oxidation method in a three-phase external loop airlift bubble column suspending completely the different concentrations of ion exchange resin particles in aqueous carboxymethyl cellulose (CMC) solutions with a wide range of viscosity. The column had been previously studied for the circulating liquid velocity UL, gas holdup G and volumetric gas-liquid oxygen transfer coefficient kLa in the two- and three-phase systems. The average bubble siz...

  17. Phase separations in mixtures of a liquid crystal and a nanocolloidal particle

    Science.gov (United States)

    Matsuyama, Akihiko

    2009-11-01

    We present a mean field theory to describe phase separations in mixtures of a liquid crystal and a nanocolloidal particle. By taking into account a nematic, a smectic A ordering of the liquid crystal, and a crystalline ordering of the nanoparticle, we calculate the phase diagrams on the temperature-concentration plane. We predict various phase separations, such as a smectic A-crystal phase separation and a smectic A-isotropic-crystal triple point, etc., depending on the interactions between the liquid crystal and the colloidal surface. Inside binodal curves, we find new unstable and metastable regions, which are important in the phase ordering dynamics. We also find a crystalline ordering of the nanoparticles dispersed in a smectic A phase and a nematic phase. The cooperative phenomena between liquid-crystalline ordering and crystalline ordering induce a variety of phase diagrams.

  18. Computation of liquid-liquid equilibria and phase stabilities: implications for RH-dependent gas/particle partitioning of organic-inorganic aerosols

    OpenAIRE

    A. Zuend; Marcolli, C.; Peter, T.; Seinfeld, J. H.

    2010-01-01

    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...

  19. Liquid crystal phases of two-dimensional dipolar gases and Berezinskii-Kosterlitz-Thouless melting.

    Science.gov (United States)

    Wu, Zhigang; Block, Jens K; Bruun, Georg M

    2016-01-01

    Liquid crystals are phases of matter intermediate between crystals and liquids. Whereas classical liquid crystals have been known for a long time and are used in electro-optical displays, much less is known about their quantum counterparts. There is growing evidence that quantum liquid crystals play a central role in many electron systems including high temperature superconductors, but a quantitative understanding is lacking due to disorder and other complications. Here, we analyse the quantum phase diagram of a two-dimensional dipolar gas, which exhibits stripe, nematic and supersolid phases. We calculate the stiffness constants determining the stability of the nematic and stripe phases, and the melting of the stripes set by the proliferation of topological defects is analysed microscopically. Our results for the critical temperatures of these phases demonstrate that a controlled study of the interplay between quantum liquid and superfluid phases is within experimental reach for the first time, using dipolar gases. PMID:26750156

  20. Switchable liquid-crystal phase-shift mask for super-resolution photolithography based on Pancharatnam-Berry phase

    Science.gov (United States)

    Glazar, Nikolaus; Culbreath, Christopher; Li, Yannian; Yokoyama, Hiroshi

    2015-11-01

    We present a novel liquid-crystal-based phase-shift mask that utilizes the Pancharatnam-Berry phase for super-resolution photolithography. Using an automated maskless photoalignment technique, we pattern an azobenzene alignment layer in a nematic liquid-crystal cell to fabricate the mask. Since the image is formed by phase cancellation, the minimum feature size is not restricted by the diffraction limit; here, we obtain submicron features. The liquid-crystal properties of the cell allow the mask to be switched on and off by applying a voltage. The cost effectiveness and flexibility of this technique make it a promising new technology for photolithography.

  1. Quantitative structure-retention relationships of pesticides in reversed-phase high-performance liquid chromatography

    International Nuclear Information System (INIS)

    In this paper, a quantitative structure-retention relationships (QSRR) method is employed to predict the retention behaviour of pesticides in reversed-phase high-performance liquid chromatography (HPLC). A six-parameter nonlinear model is developed by means of a feed-forward artificial neural network (ANN) with back-propagation learning rule. Accurate description of the retention factors of 26 compounds including commonly used insecticides, herbicides and fungicides and some metabolites is successfully achieved. In addition to the acetonitrile content, included to describe composition of the water-acetonitrile mobile phase, the octanol-water partition coefficient (from literature) and four quantum chemical descriptors are considered to account for the effect of solute structure on the retention. These are: the total dipole moment, the mean polarizability, the anisotropy of polarizability and a descriptor of hydrogen bonding ability based on the atomic charges on hydrogen bond donor and acceptor chemical functionalities. The proposed nonlinear QSRR model exhibits a high degree of correlation between observed and computed retention factors and a good predictive performance in wide range of mobile phase composition (40-65%, v/v acetonitrile) that supports its application for the prediction of the chromatographic behaviour of unknown pesticides. A multilinear regression model based on the same six descriptors shows a significantly worse predictive capability

  2. First title: Ionic liquids-useful reaction green solvents for the future Second title: ionic liquids are the replacements for environmentally damaging solvents in a wide range of chemical processes.

    Directory of Open Access Journals (Sweden)

    K.Vijaya Bhaskar

    2012-09-01

    Full Text Available Ionic liquids (IL represent fascinating new class of solvents with unusual physical and chemical properties; low melting salts (up to 1000C. The main driving force for research in this area is the need to find replacement for environmentally damaging solvents in a wide range of chemical processes. To date, most chemical reactions have been carried out in molecular solvents. For the past twenty years, most of our understanding of our chemistry has been based upon the behavior of molecules in the solution phase in molecular solvents. Recently a new class of solvents has emerged called as Ionic liquids. An ionic liquid is an organic salt in which the ions are poorly coordinated, which results in these solvents being liquid below 100°C, or even at room temperature (room temperature ionic liquids, RTIL's. At least one ion has a delocalized charge and one component is organic, which prevents the formation of a stable crystal lattice. Ionic liquids are composed entirely of ions. For example, molten sodium chloride is an ionic liquid; in contrast, a solution of sodium chloride in water (a molecular solvent is an ionic solution. The term “ionic liquids” has replaced the older phrase “molten salts” (or “melts”, which suggests that they are high-temperature, corrosive, viscous media (like molten minerals. The reality is that ionic liquids can be liquid at temperatures as low as –96°C. Furthermore, room-temperature ionic liquids are frequently colourless, fluid, and easy to handle. In the patent and academic literature, the term “ionic liquids” now refers to liquids composed entirely of ions that are fluid around or below 100°C1. Properties, such as melting point, viscosity, and solubility of starting materials and other solvents, are determined by the substituents on the organic component and by the counter ion. Many ionic liquids have even been developed for specific synthetic problems. For this reason, ionic liquids have been termed

  3. Design and Fabrication of the First Commercial-Scale Liquid Phase Methanol (LPMEOH) Reactor

    Energy Technology Data Exchange (ETDEWEB)

    None

    1998-12-21

    The Liquid Phase Methanol (LPMEOHT) process uses a slurry bubble column reactor to convert synthesis gas (syngas), primarily a mixture of carbon monoxide and hydrogen, to methanol. Because of its superior heat management the process can utilize directly the carbon monoxide (CO)-rich syngas characteristic of the gasification of coal, petroleum coke, residual oil, wastes, or other hydrocarbon feedstocks. The LPMEOHM Demonstration Project at Kingsport, Tennessee, is a $213.7 million cooperative agreement between the U.S. Department of Energy (DOE) and Air Products Liquid Phase Conversion Company, L.P., a partnership between Air Products and Chemicals, Inc. and Eastman Chemical Company, to produce methanol from coal-derived syngas. Construction of the LPMEOH~ Process Demonstration Plant at Eastman's chemicals-from-coal complex in Kingsport was completed in January 1997. Following commissioning and shakedown activities, the fwst production of methanol from the facility occurred on April 2, 1997. Nameplate capacity of 260 short tons per day (TPD) was achieved on April 6, 1997, and production rates have exceeded 300 TPD of methanol at times. This report describes the design, fabrication, and installation of the Kingsport LPMEOEFM reactor, which is the first commercial-scale LPMEOEPM reaetor ever built. The vessel is 7.5 feet in diameter and 70 feet tall with design conditions of 1000 psig at 600 `F. These dimensions represent a significant scale-up from prior experience at the DOE-owned Alternative Fuels Development Unit in LaPorte, Texas, where 18-inch and 22-inch diameter reactors have been tested successfidly over thousands of hours. The biggest obstacles discovered during the scale- up, however, were encountered during fabrication of the vessel. The lessons learned during this process must be considered in tailoring the design for future sites, where the reactor dimensions may grow by yet another factor of two.

  4. Liquid-liquid phase equilibrium and core-shell structure formation in immiscible Al-Bi-Sn alloys

    Science.gov (United States)

    Li, Mingyang; Jia, Peng; Sun, Xiaofei; Geng, Haoran; Zuo, Min; Zhao, Degang

    2016-04-01

    In this paper, the liquid-phase separation of ternary immiscible Al45Bi19.8Sn35.2 and Al60Bi14.4Sn25.6 melts was studied with resistivity and thermal analysis methods at different temperature. The resistivity-temperature curves appear abrupt and anomalously change with rising temperature, corresponding to the anomalous and low peak of melting process in DSC curves, indicative of the occurrence of the liquid-phase separation. The anomalous behavior of the resistivity temperature dependence is attributable to concentration-concentration fluctuations. The effect of composition and melt temperature on the liquid-phase separation and core-shell structure formation in immiscible Al-Bi-Sn alloys was studied. The liquid-phase separation and formation of the core-shell structure in immiscible Al-Bi-Sn alloys are readily acquired when the alloy compositions fall into liquid miscibility gap. What's more, the cross-sectional structure changes from irregular, dispersed to core-type shapes under the actions of Marangoni motion with increasing melt temperature. This study provides some clues for the preparation of core-shell microspheres of immiscible Al-Bi-Sn alloys via liquid-phase separation.

  5. Evidence of a Liquid-Liquid Phase Transition Hot Dense Hydrogen

    Science.gov (United States)

    Silvera, Isaac; Dzyabura, Vasily; Zaghoo, Mohamed

    2013-03-01

    We use pulsed laser heating of hydrogen at static pressures in the megabar pressure region generated in a diamond anvil cell to search for the plasma phase transition (PPT) to liquid atomic metallic hydrogen. Heating the sample substantially above the melting line we observe a plateau in a temperature vs laser power curve that otherwise increases with power. This anomaly in the heating curve is closely correlated with theoretical predictions for the PPT, falling within the theoretically predicted range and having a negative slope with increasing pressure. Details will be presented. The NSF, grant DMR-0804378 and the DOE Stockpile Stewardship Academic Alliance program, grant DE-FG52-10NA29656 supported this research.

  6. 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 2μgL(-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. PMID:26896916

  7. The phase transport and reactions of γ-irradiated aqueous-ionic liquids

    International Nuclear Information System (INIS)

    A novel technology based on the transfer of chemical species across water/ionic liquid interfaces via specific complexation reactions is currently being considered for the separation and sequestration of metal ion contaminants from radioactive waste effluents in the nuclear fuel cycle. An ideal solvent for these applications should have a high intrinsic selectivity for a targeted metal or group of metals (e.g., trans-Pu actinides, lanthanides, or other fission products), an efficient switching mechanism (between complexation and decomplexation), and a high immiscibility with aqueous solutions. These characteristics must be maintained in the chemical, radiation, and mass transport environments present during the separation process. Ionic liquids (ILs) have an almost negligible vapour pressure and high thermal stability. Their ability to dissolve a wide range of substrate molecules and potential to be highly resilient in radiation fields make ILs particularly promising media. The separation efficiency of the biphasic system will depend on many parameters, including the aqueous oxidation state of the targeted metal ion, and the thermodynamics and kinetics of interfacial transport and metal-ligand complex formation at the water/IL interface or in the IL phase. The most uncertain and unstudied area for these applications is the effect of ionizing radiation on the stability and separation efficiency of the biphasic system. The present study investigates the effect of γ-radiation on gas/IL and water/IL interfacial stability and mass transfer with trihexyltetradecylphosphonium bis(trifluoromethyl-sulfonyl)imide, a phosphonium-based IL. The IL, in contact with either gas or water, was irradiated at a dose rate of 6.4 kGy·h-1. Gas-phase samples were analyzed by gas chromatography-mass spectrometry (GC-MS) and the changes in the IL and aqueous phases were monitored by conductivity measurements and Raman spectroscopy. In this paper we discuss these observations and their

  8. Non-equilibrium phase transitions in a liquid crystal.

    Science.gov (United States)

    Dan, K; Roy, M; Datta, A

    2015-09-01

    The present manuscript describes kinetic behaviour of the glass transition and non-equilibrium features of the "Nematic-Isotropic" (N-I) phase transition of a well known liquid crystalline material N-(4-methoxybenzylidene)-4-butylaniline from the effects of heating rate and initial temperature on the transitions, through differential scanning calorimetry (DSC), Fourier transform infrared and fluorescence spectroscopy. Around the vicinity of the glass transition temperature (Tg), while only a change in the baseline of the ΔCp vs T curve is observed for heating rate (β) > 5 K min(-1), consistent with a glass transition, a clear peak for β ≤ 5 K min(-1) and the rapid reduction in the ΔCp value from the former to the latter rate correspond to an order-disorder transition and a transition from ergodic to non-ergodic behaviour. The ln β vs 1000/T curve for the glass transition shows convex Arrhenius behaviour that can be explained very well by a purely entropic activation barrier [Dan et al., Eur. Phys. Lett. 108, 36007 (2014)]. Fourier transform infrared spectroscopy indicates sudden freezing of the out-of-plane distortion vibrations of the benzene rings around the glass transition temperature and a considerable red shift indicating enhanced coplanarity of the benzene rings and, consequently, enhancement in the molecular ordering compared to room temperature. We further provide a direct experimental evidence of the non-equilibrium nature of the N-I transition through the dependence of this transition temperature (TNI) and associated enthalpy change (ΔH) on the initial temperature (at fixed β-values) for the DSC scans. A plausible qualitative explanation based on Mesquita's extension of Landau-deGennes theory [O. N. de Mesquita, Braz. J. Phys. 28, 257 (1998)] has been put forward. The change in the molecular ordering from nematic to isotropic phase has been investigated through fluorescence anisotropy measurements where the order parameter, quantified by the

  9. Phase Transition and Dynamics in Imidazolium-Based Ionic Liquid Crystals through a Metastable Highly Ordered Smectic Phase.

    Science.gov (United States)

    Nozaki, Yoko; Yamaguchi, Keito; Tomida, Kenji; Taniguchi, Natsumi; Hara, Hironori; Takikawa, Yoshinori; Sadakane, Koichiro; Nakamura, Kenji; Konishi, Takashi; Fukao, Koji

    2016-06-16

    The phase transition behavior and dynamics of ionic liquid crystals, 1-methyl-3-alkylimidazolium tetrafluoroborate with various alkyl chain lengths, were investigated by X-ray scattering, differential scanning calorimetry, optical microscopy, and dielectric relaxation spectroscopy to elucidate the mechanism of their structural and phase changes. A metastable phase was found to appear via a supercooled smectic phase on cooling. In the metastable phase, disorder in the smectic phase is partially frozen; thus, the phase has order higher than that of the smectic phase but lower than that of the crystalline phase. During the subsequent heating process, the frozen disorder activates, and a crystalline phase appears in the supercooled smectic phase before entering the smectic phase. The relationship between the phase behavior and the dynamics of charge carriers such as ions is also discussed. PMID:27195480

  10. Development of multi components and multi phase numerical method with chemical reaction. Examination of multi phase numerical method

    International Nuclear Information System (INIS)

    In the steam generator using liquid sodium, Water intensely reacts with sodium when it leaked out from a heat tube. It is important to evaluate an influence of the sodium-water reaction to, such as, heat tubes surrounding a leakage and the generator. In the past, evaluations of this phenomenon have been carried out by experiments. However it is difficult to extrapolate an effect by configuration of a heat tube or change of operating condition, etc. and experiments using sodium need incredible cost. Then quantification by a numerical method is desirable. To develop a multi component and multi phase numerical method with chemical reaction, fundamental models of a multi phase numerical method are selected with organizing previous works in this paper, as follows. Fluid model : multi fluid model, Pressure model : one pressure model, Solving method : HSMAC (Highly Simplified Maker And Cell) method. Two-dimensional two-phase flow analysis technique is developed to evaluate a validity of these models. And verification analyses are carried out shown in the following. Two-dimensional square cavity flow. Two-dimensional natural convection in a square cavity. Air blow down from a pressure vessel. Dam break-down problem. Edwards pipe blow down problem. In each verification analysis, good agreements are obtained and the validity of the models to a multi phase numerical method is confirmed. (author)

  11. Effect of entrained liquid on turbulent mixing rate between subchannels in annular two-phase flows

    International Nuclear Information System (INIS)

    Turbulent mixing rates of gas and liquid phases between the subchannels have been measured for various air-water two-phase annular flows in a multiple channel consisting of the two identical circular subchannels. In order to study effect of entrained liquid in the gas core on the turbulent mixing rates, experiments were conducted for two types of liquid injection method, i.e., a small bore nozzle placed in the subchannel center and a porous wall, at a fixed gas injection method. The result showed that the effect of entrained liquid on the turbulent mixing rates of both phases is negligibly small. (author)

  12. A binary phase field crystal study for liquid phase heteroepitaxial growth

    Science.gov (United States)

    Lu, Yanli; Peng, Yingying; Chen, Zheng

    2016-09-01

    The liquid phase heteroepitaxial growth on predefined crystalline substrate is studied with binary phase field crystal (PFC) model. The purpose of this paper focuses on changes of the morphology of epitaxial films, influences of substrate vicinal angles on epitaxial growth, characteristics of islands growth on both sides of the substrate as well. It is found that the morphology of epitaxial films undergoes the following transitions: layer-by-layer growth, islands formation, mismatch dislocations nucleation and climb towards the film-substrate interface. Meanwhile, the density of steps and islands has obviously direct ratio relations with the vicinal angles. Also, preferential regions are found when islands grow on both sides of the substrate. For thinner substrate, the arrangement of islands is more orderly and the appearance of preferential growth is more obvious than that of thicker substrate. Also, the existing of preferential regions is much more valid for small substrate vicinal angles in contrast for big substrate vicinal angles.

  13. Catalyst activity maintenance study for the liquid phase dimethyl ether process

    Energy Technology Data Exchange (ETDEWEB)

    Peng, X.D.; Toseland, B.A.; Underwood, R.P. [Air Products and Chemicals, Inc., Allentown, PA (United States)

    1995-12-31

    The co-production of dimethyl ether (DME) and methanol from syngas is a process of considerable commercial attractiveness. DME coproduction can double the productivity of a LPMEOH process when using coal-derived syngas. This in itself may offer chemical producers and power companies increased flexibility and more profitable operation. DME is also known as a clean burning liquid fuel; Amoco and Haldor-Topsoe have recently announced the use of DME as an alternative diesel fuel. Moreover, DME can be an interesting intermediate in the production of chemicals such as olefins and vinyl acetate. The current APCl liquid phase dimethyl ether (LPDME) process utilizes a physical mixture of a commercial methanol synthesis catalyst and a dehydration catalyst (e.g., {gamma}-alumina). While this arrangement provides a synergy that results in much higher syngas conversion per pass compared to the methanol-only process, the stability of the catalyst system suffers. The present project is aimed at reducing catalyst deactivation both by understanding the cause(s) of catalyst deactivation and by developing modified catalyst systems. This paper describes the current understanding of the deactivation mechanism.

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

    NARCIS (Netherlands)

    Mourad, M.C.D.

    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 gi

  15. Separation of gas from liquid in a two-phase flow system

    Science.gov (United States)

    Hayes, L. G.; Elliott, D. G.

    1973-01-01

    Separation system causes jets which leave two-phase nozzles to impinge on each other, so that liquid from jets tends to coalesce in center of combined jet streams while gas phase is forced to outer periphery. Thus, because liquid coalescence is achieved without resort to separation with solid surfaces, cycle efficiency is improved.

  16. 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

    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......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...... solvents. Here we show results for heavier and more-than-sparingly solutes such as carbon dioxide and propane in ionic liquids....

  17. Integration of phase separation with ultrasound-assisted salt-induced liquid-liquid microextraction for analyzing the fluoroquinones in human body fluids by liquid chromatography

    OpenAIRE

    Wang, H; Gao, M.; Wang, M.; Zhang, R.; W. Wang; Dahlgren, RA; Wang, X.

    2015-01-01

    © 2015 Elsevier B.V. Herein, we developed a novel integrated device to perform phase separation based on ultrasound-assisted salt-induced liquid-liquid microextraction for determination of five fluoroquinones (FQs) in human body fluids. The integrated device consisted of three simple HDPE components used to separate the extraction solvent from the aqueous phase prior to retrieving the extractant. A series of extraction parameters were optimized using the response surface method based on centr...

  18. A polarization-independent liquid crystal phase modulation using polymer-network liquid crystal with orthogonal alignment layers

    Science.gov (United States)

    Chen, Ming-Syuan; Lin, Wei-Chih; Tsou, Yu-Shih; Lin, Yi-Hsin

    2012-10-01

    A polarization-independent liquid crystal (LC) phase modulation using polymer-network liquid crystals with orthogonal alignments layers (T-PNLC) is demonstrated. T-PNLC consists of three layers. LC directors in the two layers near glass substrates are orthogonal to each other. In the middle layer, LC directors are perpendicular to the glass substrate. The advantages of such T-PNLC include polarizer-free, larger phase shift (~0.4π rad) than the residual phase type (<0.05π rad), and low operating voltage (< 30Vrms). It does not require bias voltage for avoiding scattering because the refractive index of liquid crystals matches that of polymers. The phase shift of T-PNLC is affected by the cell gap and the curing voltages. The potential applications are laser beam steering, spatial light modulators and electrically tunable micro-lens arrays.

  19. 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.

  20. Phosphopeptide elution times in reversed-phase liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeongkwon; Petritis, Konstantinos; Shen, Yufeng; Camp, David G.; Moore, Ronald J.; Smith, Richard D.

    2007-11-16

    Elution time shifts between 33 different peptides and their corresponding phosphopeptides ranging from 4 amino acid residues to 35 amino acids in length were systematically investigated utilizing a high resolution reversed-phase liquid chromatography (RPLC) system. Observed peptide elution time shifts for a single phosphorylation ranged from -5.28 min (for pYVPML) to +0.59 min (for HRDpSGLLDSLGR). Peptides containing a phosphotyrosine residue displayed a significant decrease in elution time following phosphorylation compared to their similar-sized peptides with phosphoserine or phosphothreonine residues. While the observed elution time generally decreased due to phosphorylation, five peptides displayed increased elution time as a result of phosphorylation. For large peptides (≥ 18 amino acids), the elution time shifts due to single phosphorylation were limited (ranging between -0.48 min and +0.03 min), while the elution time shifts for small peptides (< 18 amino acids) were characterized by a larger deviation (ranging between -5.28 min and +0.59 min). The predictive capability for the observed RPLC elution time change due to phosphorylation has been suggested, which will aid in assigning confident phosphopeptide identifications and their subsequent confirmation.

  1. Liquid and chemical fluxes in precipitation, throughfall and stemflow

    DEFF Research Database (Denmark)

    Pryor, S.C.; Barthelmie, R.J.

    2005-01-01

    Wet deposition (WD), throughfall (TF) and stemflow (SF) measurements undertaken in a deciduous forest show 85% of the WD liquid flux is observed as TF and approximately 2% as SF. TF and SF were observed to be enriched in base cations and accordingly had an average pH of 6.1 and 5.9, respectively ...

  2. Alignment of liquid crystals : on geometrically and chemically modified surfaces

    NARCIS (Netherlands)

    Zhang, Jing

    2013-01-01

    This thesis consists of two main parts. The first part describes a new model to explain the complex role of surface materials and surface geometry in the liquid crystal (LC) alignment, which has been a subject of intensive debate over the last 40 years. The second part presents a potentially cost ef

  3. Effect of vapor- and liquid-phase radiation grafting on water permeability of porous hollow-fiber membrane

    International Nuclear Information System (INIS)

    Effect of the radiation-induced graft polymerization of monomers in vapor and liquid phases to the hollow-fiber membrane microfilter, made of porous high density polyethylene, upon the permeability of water has been studied. Determination of the flux of hollow-fiber membranes prepared by the graft polymerization of acrylonitrile, vinyl acetate, styrene, or acrylic acid revealed that the membranes prepared by vapor-phase grafting had a higher flux than those prepared by liquid-phase grafting. The measurement of pore volume and dimensional change revealed that hollow-fiber membrane grafted in vapor phase swells to larger extent. Cyano group of acrylonitrile and acetoxyl group of vinyl acetate, grafted to hollow-fiber membrane were converted to amide oxime and alcoholic hydroxyl group, respectively by the chemical modification. The flux of these functionalized membranes were determined and it is found that the functionalized membranes derived from vapor-phase grafted membrane had higher water permeability than those derived from liquid-phase grafted ones. (author)

  4. Numerical analysis of supersonic gas jets into liquid pools with or without chemical reaction using the SERAPHIM program

    International Nuclear Information System (INIS)

    Highlights: ► We perform numerical analysis on gas jet into liquid with or without reaction. ► We apply multi-fluid model and surface reaction model. ► Proposed model can reproduce behaviors of gas jet into liquid with reaction. - Abstract: A computer program called SERAPHIM has been developed to calculate multicomponent multiphase flow involving sodium-water chemical reaction in a steam generator of sodium cooled fast reactors. In this study, numerical analyses of supersonic gas jets into liquid pools with or without chemical reaction were performed to validate proposed numerical methods. The SERAPHIM program uses a multi-fluid model and a HSMAC method modified for compressible multiphase flows. An interfacial drag force was calculated from a newly constructed model. A surface reaction model, which has been developed by the authors, was applied to evaluate a mass generation rate by chemical reaction between a gas and liquid phase. As validation for a non-reaction problem, the experiment on horizontal supersonic air jet into water was analyzed. Numerical results showed that velocity of the injected air decreased by the effect of a interfacial drag force, and then the air went upward because of buoyancy. A horizontal penetration length of the air jet agreed with experimental results very well. On the other hand, we analyzed the experiment on vertical supersonic chlorine jet into Na–NaCl mixture. In this analysis, the injected gas disappeared at a certain height from chemical reaction. An estimated plume length showed good agreement with experimental data. The proposed numerical methods were found to be applicable to multiphase flow with supersonic gas jet and chemical reaction.

  5. In-situ Liquid Phase Epitaxy: Another Strategy to Synthesize Heterostructured Core-shell Composites

    Science.gov (United States)

    Wen, Zhongsheng; Wang, Guanqin

    2016-04-01

    Core-shell Nb2O5/TiO2 composite with hierarchical heterostructure is successfully synthesized In-situ by a facile template-free and acid-free solvothermal method based on the mechanism of liquid phase epitaxy. The chemical circumstance change induced by the alcoholysis of NbCl5 is utilized tactically to trigger core-shell assembling In-situ. The tentative mechanism for the self-assembling of core-shell structure and hierarchical structure is explored. The microstructure and morphology changes during synthesis process are investigated systematically by using X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and transmission electron microscopy. The dramatic alcoholysis of NbCl5 has been demonstrated to be the fundamental factor for the formation of the spherical core, which changes the acid circumstance of the solution and induces the co-precipitation of TiO2. The homogeneous co-existence of Nb2O5/TiO2 in the core and the co-existence of Nb/Ti ions in the reaction solution facilitate the In-situ nucleation and epitaxial growth of the crystalline shell with the same composition as the core. In-situ liquid phase epitaxy can offer a different strategy for the core-shell assembling for oxide materials.

  6. In-situ Liquid Phase Epitaxy: Another Strategy to Synthesize Heterostructured Core-shell Composites

    Science.gov (United States)

    Wen, Zhongsheng; Wang, Guanqin

    2016-01-01

    Core-shell Nb2O5/TiO2 composite with hierarchical heterostructure is successfully synthesized In-situ by a facile template-free and acid-free solvothermal method based on the mechanism of liquid phase epitaxy. The chemical circumstance change induced by the alcoholysis of NbCl5 is utilized tactically to trigger core-shell assembling In-situ. The tentative mechanism for the self-assembling of core-shell structure and hierarchical structure is explored. The microstructure and morphology changes during synthesis process are investigated systematically by using X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and transmission electron microscopy. The dramatic alcoholysis of NbCl5 has been demonstrated to be the fundamental factor for the formation of the spherical core, which changes the acid circumstance of the solution and induces the co-precipitation of TiO2. The homogeneous co-existence of Nb2O5/TiO2 in the core and the co-existence of Nb/Ti ions in the reaction solution facilitate the In-situ nucleation and epitaxial growth of the crystalline shell with the same composition as the core. In-situ liquid phase epitaxy can offer a different strategy for the core-shell assembling for oxide materials. PMID:27121200

  7. Field test of high molecular weight alcohol flushing for subsurface nonaqueous phase liquid remediation

    Science.gov (United States)

    Falta, Ronald W.; Lee, Cindy M.; Brame, Scott E.; Roeder, Eberhard; Coates, John T.; Wright, Charles; Wood, A. Lynn; Enfield, Carl G.

    1999-07-01

    A pilot scale field test of non-aqueous phase liquid (NAPL) removal using high molecular weight alcohols was conducted at Operable Unit 1, Hill Air Force Base, Utah. Petroleum hydrocarbons and spent solvents were disposed of in chemical disposal pits at this site, and these materials are now present in the subsurface in the form of a light non-aqueous phase liquid (LNAPL). This LNAPL is a complex mixture of aromatic and aliphatic hydrocarbons, chlorinated solvents, and other compounds. The field experiment was performed in a 5 m by 3 m confined test cell, formed by driving interlocking sheet pile walls through the contaminated zone into an underlying clay. The test involved the injection and extraction of about four pore volumes (1 pore volume=7000 L) of a mixture of 80% tert-butanol and 15% n-hexanol. The contaminants were removed by a combination of NAPL mobilization and enhanced dissolution, and the results of postflood soil coring indicate better than 90% removal of the more soluble contaminants (trichloroethane, toluene, ethylbenzene, xylenes, trimethylbenzene, naphthalene) and 70-80% removal of less soluble compounds (decane and undecane). The results of preflood and postflood NAPL partitioning tracer tests show nearly 80% removal of the total NAPL content from the test cell. The field data suggest that a somewhat higher level of removal could be achieved with a longer alcohol injection.

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

    International Nuclear Information System (INIS)

    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

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

    NARCIS (Netherlands)

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

    2006-01-01

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

  10. Quaternary (liquid + liquid) equilibria for systems of imidazolium based ionic liquid + thiophene + pyridine + cyclohexane at 298.15 K: Experiments and quantum chemical predictions

    International Nuclear Information System (INIS)

    Highlights: ► Quaternary (liquid + liquid) equilibria are measured for ionic liquids, cyclohexane, pyridine and thiophene. ► Extraction of thiophene and pyridine from cyclohexane using ionic liquids is investigated. ► Three different ionic liquids are investigated. ► The experimental data can be successfully correlated using NRTL and UNIQUAC models. ► The experimental data are in moderate agreement with a priori predictions made using the COSMO-SAC model. -- Abstract: 1-Ethyl 3-methylimidazolium acetate [EMIM][OAc], 1-ethyl 3-methylimidazolium ethylsulfate [EMIM][EtSO4] and 1-ethyl 3-methylimidazolium methylsulfonate [EMIM][MeSO3] are found to be effective for the selective removal of a five member ring sulfur compound, viz. thiophene, and a six member ring nitrogen compound, viz. pyridine from a hydrocarbon, viz. cyclohexane at room temperature and atmospheric pressure. The liquid liquid equilibrium (LLE) data for the quaternary mixtures of ionic liquid (1) + thiophene (2) + pyridine (3) + cyclohexane (4) are experimentally determined. The experimental tie line data are successfully correlated with the Non Random Two Liquid (NRTL) and UNIversal QUAasi-Chemical (UNIQUAC) models, which provide a good correlation of the experimental data with root mean square deviation (RMSD) values less than unity for all the studied systems. The results suggest that the structure and size of the anion greatly affects the extractive performance of ionic liquids. The reliability of experimental data is ascertained by applying the quantum chemical based COnductor like Screening Model-Segment Activity Coefficient (COSMO-SAC) model. The goodness of the fit is determined by calculating the RMSD values. The RMSD values obtained for [EMIM][OAc], [EMIM][EtSO4] and [EMIM][MeSO3] are 10.4%, 8.1% and 12.2%, respectively

  11. Finite size effects in liquid-gas phase transition of asymmetric nuclear matter

    International Nuclear Information System (INIS)

    Full text: Since the nuclear equation of state has been studied in astrophysical context as an element of neutron star or super-nova theories - a call for an evidence was produced in experimental nuclear physics. Heavy-ion collisions became a tool of study on thermodynamic properties of nuclear matter. A particular interest has been inspired here by critical behavior of nuclear systems, as a phase transition of liquid-gas type. A lot of efforts was put to obtain an experimental evidence of such a phenomenon in heavy-ion collisions. With the use of radioactive beams and high performance identification systems in a near future it will be possible to extend experimental investigation to asymmetric nuclear systems, where neutron-to-proton ratio is far from the stability line. This experimental development needs a corresponding extension of theoretical studies. To obtain a complete theory of the liquid-gas phase transition in small nuclear systems, produced in violent heavy-ion collisions, one should take into account two facts. First, that the nuclear matter forming nuclei is composed of protons and neutrons; this complicates the formalism of phase transitions because one has to deal with two separate, proton and neutron, densities and chemical potentials. The second and more important is that the surface effects are very strong in a system composed of a few hundreds of nucleons. This point is especially difficult to hold, because surface becomes an additional, independent state parameter, depending strongly on the geometrical configuration of the system, and introducing a non-local term in the equation of state. In this presentation we follow the recent calculation by Lee and Mekjian on the finite-size effects in small (A = 102 -103) asymmetric nuclear systems. A zero-range isospin-dependent Skyrme force is used to obtain a density and isospin dependent potential. The potential is then completed by additional terms giving contributions from surface and Coulomb

  12. Synthesis and Engineering Materials Properties of Fluid Phase Chemical Hydrogen Storage Materials for Automotive Applications

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Young Joon; Westman, Matthew P.; Karkamkar, Abhijeet J.; Chun, Jaehun; Ronnebro, Ewa

    2015-09-01

    Among candidates for chemical hydrogen storage in PEM fuel cell automotive applications, ammonia borane (AB, NH3BH3) is considered to be one of the most promising materials due to its high practical hydrogen content of 14-16 wt%. This material is selected as a surrogate chemical for a hydrogen storage system. For easier transition to the existing infrastructure, a fluid phase hydrogen storage material is very attractive and thus, we investigated the engineering materials properties of AB in liquid carriers for a chemical hydrogen storage slurry system. Slurries composed of AB and high temperature liquids were prepared by mechanical milling and sonication in order to obtain stable and fluidic properties. Volumetric gas burette system was adopted to observe the kinetics of the H2 release reactions of the AB slurry and neat AB. Viscometry and microscopy were employed to further characterize slurries engineering properties. Using a tip-sonication method we have produced AB/silicone fluid slurries at solid loadings up to 40wt% (6.5wt% H2) with viscosities less than 500cP at 25°C.

  13. Growth of epitaxial sodium-bismuth-titanate films by metal-organic chemical vapor phase deposition

    Energy Technology Data Exchange (ETDEWEB)

    Schwarzkopf, J., E-mail: schwarzkopf@ikz-berlin.de [Leibniz Institute for Crystal Growth, Max-Born-Strasse 2, 12489 Berlin (Germany); Schmidbauer, M.; Duk, A.; Kwasniewski, A. [Leibniz Institute for Crystal Growth, Max-Born-Strasse 2, 12489 Berlin (Germany); Anooz, S. Bin [Leibniz Institute for Crystal Growth, Max-Born-Strasse 2, 12489 Berlin (Germany); Physics Department, Faculty of Science, Hadhramout University of Science and Technology, Mukalla 50511, Republic of Yemen (Yemen); Wagner, G. [Leibniz Institute for Crystal Growth, Max-Born-Strasse 2, 12489 Berlin (Germany); Devi, A. [Inorganic Materials Chemistry, Ruhr-University Bochum, Universitaetsstr. 150, 44801 Bochum (Germany); Fornari, R. [Leibniz Institute for Crystal Growth, Max-Born-Strasse 2, 12489 Berlin (Germany)

    2011-10-31

    The liquid-delivery spin metal-organic chemical vapor phase deposition method was used to grow epitaxial sodium-bismuth-titanate films of the system Bi{sub 4}Ti{sub 3}O{sub 12} + xNa{sub 0.5}Bi{sub 0.5}TiO{sub 3} on SrTiO{sub 3}(001) substrates. Na(thd), Ti(O{sup i}Pr){sub 2}(thd){sub 2} and Bi(thd){sub 3}, solved in toluene, were applied as source materials. Depending on the substrate temperature and the Na/Bi ratio in the gas phase several structural phases of sodium-bismuth-titanate were detected. With increasing temperature and/or Na/Bi ratio, phase transitions from an Aurivillius phase with m = 3 to m = 4 via an interleaved state with m = 3.5, and, finally, to Na{sub 0.5}Bi{sub 0.5}TiO{sub 3} with perovskite structure (m = {infinity}) were established. These phase transitions proceed at remarkably lower temperatures than in ceramics or bulk crystals for which they had been exclusively observed so far.

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

    International Nuclear Information System (INIS)

    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 K2HPO4 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/K2HPO4 were effective for aqueous two phases extraction of acrylic acid comparing to imidazolium ionic liquids/K2HPO4 systems because of their lower cost

  15. Ultrahigh-pressure liquid chromatography of isoflavones and phenolic acids on different stationary phases.

    Science.gov (United States)

    Klejdus, B; Vacek, J; Lojková, L; Benesová, L; Kubán, V

    2008-06-27

    Complete separation of aglycones and glucosides of selected isoflavones (genistin, genistein, daidzin, daidzein, glycitin, glycitein, ononin, sissotrin, formononetin, and biochanin A) was possible in 1.5 min using an ultrahigh-pressure liquid chromatography (U-HPLC) on a different particular chemically modified stationary phases with a particle size under 2 microm. In addition, selected separation conditions for simultaneous determination of isoflavones together with a group of phenolic acids (gallic, protocatechuic, p-hydroxybenzoic, vanillic, caffeic, syringic, p-coumaric, ferulic, and sinapic acid) allowed separation of all 19 compounds in 1.9 min. Separations were conducted on a non-polar reversed phase (C(18)) and also on more polar phases with cyanopropyl or phenyl groups using a gradient elution with a mobile phase consisting of 0.3% aqueous acetic acid and methanol. Chromatographic peaks were characterised using parameters such as resolution, symmetry, selectivity, etc. Individual substances were identified and quantified using UV-vis diode array detector at wavelength 270 nm. Limits of detection (3S/N) were in the range 200-400 pg ml(-1). Proposed U-HPLC technique was used for separation of isoflavones and phenolic acids in samples of plant materials (Trifolium pratense, Glycine max, Pisum sativum and Ononis spinosa) after acid hydrolysis of the samples and modified Soxhlet extraction. PMID:18501366

  16. Liquid phase sintered SiC. Processing and transformation controlled microstructure tailoring

    Directory of Open Access Journals (Sweden)

    V.A. Izhevskyi

    2000-10-01

    Full Text Available Microstructure development and phase formation processes during sintering of silicon carbide based materials with AlN-Y2O3, AlN-Yb2O3, and AlN-La2O3 sintering additives were investigated. Densification of the materials occurred by liquid-phase sintering mechanism. Proportion of alpha- and beta-SiC powders in the initial mixtures was a variable parameter, while the molar ratio of AlN/RE2O3, and the total amount of additives (10 vol. % were kept constant. Shrinkage behavior during sintering in interrelation with the starting composition of the material and the sintering atmosphere was investigated by high temperature dilatometry. Kinetics of b-SiC to a-SiC phase transformation during post-sintering heat treatment at temperatures 1900-1950 °C was studied, the degree of phase transformation being determined by quantitative x-ray analysis using internal standard technique. Evolution of microstructure resulting from beta-SiC to alpha-SiC transformation was followed up by scanning electron microscopy on polished and chemically etched samples. Transformation-controlled grain growth mechanism similar to the one observed for silicon nitride based ceramics was established. Possibility of in-situ platelet reinforced dense SiC-based ceramics fabrication with improved mechanical properties by means of sintering was shown.

  17. PWR steam generator chemical cleaning, Phase I. Final report

    International Nuclear Information System (INIS)

    United Nuclear Industries (UNI) entered into a subcontract with Consolidated Edison Company of New York (Con Ed) on August 8, 1977, for the purpose of developing methods to chemically clean the secondary side tube to tube support crevices of the steam generators of Indian Point Nos. 1 and 2 PWR plants. This document represents the first reporting on activities performed for Phase I of this effort. Specifically, this report contains the results of a literature search performed by UNI for the purpose of determining state-of-the-art chemical solvents and methods for decontaminating nuclear reactor steam generators. The results of the search sought to accomplish two objectives: (1) identify solvents beyond those proposed at present by UNI and Con Ed for the test program, and (2) confirm the appropriateness of solvents and methods of decontamination currently in use by UNI

  18. PWR steam generator chemical cleaning, Phase I. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Rothstein, S.

    1978-07-01

    United Nuclear Industries (UNI) entered into a subcontract with Consolidated Edison Company of New York (Con Ed) on August 8, 1977, for the purpose of developing methods to chemically clean the secondary side tube to tube support crevices of the steam generators of Indian Point Nos. 1 and 2 PWR plants. This document represents the first reporting on activities performed for Phase I of this effort. Specifically, this report contains the results of a literature search performed by UNI for the purpose of determining state-of-the-art chemical solvents and methods for decontaminating nuclear reactor steam generators. The results of the search sought to accomplish two objectives: (1) identify solvents beyond those proposed at present by UNI and Con Ed for the test program, and (2) confirm the appropriateness of solvents and methods of decontamination currently in use by UNI.

  19. Effect of Liquid Ga on Metal Surfaces: Characterization of Morphology and Chemical Composition of Metals Heated in Liquid Ga

    International Nuclear Information System (INIS)

    This study investigates the effect of liquid gallium (Ga) on metal foils made of titanium (Ti), niobium (Nb), and molybdenum (Mo). The Ti, Nb, and Mo foils were heated in liquid Ga at 120°C for a maximum of two weeks. After heating, the changes in the morphology and the chemical composition of the metal foils were analyzed by using a field emission scanning electron microscope, energy-dispersive X-ray spectrometer, X-ray diffractometer, and X-ray photoelectron spectrometer. The results of the analysis indicated that the Nb foil showed the minimum adhesion of liquid Ga to the surface while the maximum amount of liquid Ga was observed to adhere to the Ti foil. In addition, the Nb foil was oxidized and the Mo foil was reduced during the heating process. Considering these effects, we conclude that Mo may be used as an alternative encapsulation material for Ga in addition to Nb, which is used as the conventional encapsulation material, due to its chemical resistance against oxidation in hot liquid Ga.

  20. Effect of Liquid Ga on Metal Surfaces: Characterization of Morphology and Chemical Composition of Metals Heated in Liquid Ga

    Directory of Open Access Journals (Sweden)

    Eun Je Lee

    2013-01-01

    Full Text Available This study investigates the effect of liquid gallium (Ga on metal foils made of titanium (Ti, niobium (Nb, and molybdenum (Mo. The Ti, Nb, and Mo foils were heated in liquid Ga at 120°C for a maximum of two weeks. After heating, the changes in the morphology and the chemical composition of the metal foils were analyzed by using a field emission scanning electron microscope, energy-dispersive X-ray spectrometer, X-ray diffractometer, and X-ray photoelectron spectrometer. The results of the analysis indicated that the Nb foil showed the minimum adhesion of liquid Ga to the surface while the maximum amount of liquid Ga was observed to adhere to the Ti foil. In addition, the Nb foil was oxidized and the Mo foil was reduced during the heating process. Considering these effects, we conclude that Mo may be used as an alternative encapsulation material for Ga in addition to Nb, which is used as the conventional encapsulation material, due to its chemical resistance against oxidation in hot liquid Ga.

  1. Chemical phase analysis of seed mediated synthesized anisotropic silver nanoparticles

    Science.gov (United States)

    Bharti, Amardeep; Singh, Suman; Singla, M. L.; Goyal, Navdeep

    2015-08-01

    Noble-metal nanoparticles are of great interest because of its broad applications almost in every stream (i.e. biology, chemistry and engineering) due to their unique size/shape dependant properties. In this paper, chemical phase of seed mediated synthesized anisotropic silver nanoparticle (AgNPs) has been investigated via fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). These nanaoparticles were synthesized by seed-growth method controlled by urea and dextrose results to highly stable 12-20 nm particle size revealed by zeta potential and transmission electron microscopy (TEM).

  2. Chemical phase analysis of seed mediated synthesized anisotropic silver nanoparticles

    International Nuclear Information System (INIS)

    Noble-metal nanoparticles are of great interest because of its broad applications almost in every stream (i.e. biology, chemistry and engineering) due to their unique size/shape dependant properties. In this paper, chemical phase of seed mediated synthesized anisotropic silver nanoparticle (AgNPs) has been investigated via fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). These nanaoparticles were synthesized by seed-growth method controlled by urea and dextrose results to highly stable 12-20 nm particle size revealed by zeta potential and transmission electron microscopy (TEM)

  3. Synthesis of chiral polyaniline films via chemical vapor phase polymerization

    DEFF Research Database (Denmark)

    Chen, J.; Winther-Jensen, B.; Pornputtkul, Y.; West, K.; Kane-Maquire, L.; Wallace, G.G.

    2006-01-01

    Electrically and optically active polyaniline films doped with (1)-(-)-10- camphorsulfonic acid were successfully deposited on nonconductive substrates via chemical vapor phase polymerization. The above polyaniline/ R- camphorsulfonate films were characterized by electrochemical and physical...... methods, such as cyclic voltammetry (CV), UV- vis spectroscopy, four- point probe conductivity measurement, Raman spectroscopy, circular dichroism spectroscopy, and scanning electron microscopy. The polyaniline films grown by this method not only showed high electrochemical activity, supported by CV and...... Raman spectrum, but also exhibited optical activity corresponding to the polymer chains as observed by circular dichroism spectra. (c) 2005 The Electrochemical Society....

  4. Tracking plasma generated H2O2 from gas into liquid phase and revealing its dominant impact on human skin cells

    International Nuclear Information System (INIS)

    The pathway of the biologically active molecule hydrogen peroxide (H2O2) from the plasma generation in the gas phase by an atmospheric pressure argon plasma jet, to its transition into the liquid phase and finally to its inhibiting effect on human skin cells is investigated for different feed gas humidity settings. Gas phase diagnostics like Fourier transformed infrared spectroscopy and laser induced fluorescence spectroscopy on hydroxyl radicals (·OH) are combined with liquid analytics such as chemical assays and electron paramagnetic resonance spectroscopy. Furthermore, the viability of human skin cells is measured by Alamar Blue® assay. By comparing the gas phase results with chemical simulations in the far field, H2O2 generation and destruction processes are clearly identified. The net production rate of H2O2 in the gas phase is almost identical to the H2O2 net production rate in the liquid phase. Moreover, by mimicking the H2O2 generation of the plasma jet with the help of an H2O2 bubbler it is concluded that the solubility of gas phase H2O2 plays a major role in generating hydrogen peroxide in the liquid. Furthermore, it is shown that H2O2 concentration correlates remarkably well with the cell viability. Other species in the liquid like ·OH or superoxide anion radical (O2⋅−) do not vary significantly with feed gas humidity. (paper)

  5. Combined physical and chemical absorption of carbon dioxide in a mixture of ionic liquids

    International Nuclear Information System (INIS)

    Highlights: • Carbon dioxide can be absorbed in mixtures of two ionic liquids: [C2mim][EtSO4] and [C2mim][OAc]. • A combination of physical and chemical absorption mechanisms is observed. • The CO2 absorption capacity of the mixture of ionic liquids decreases with increasing temperature. • [C2mim][EtSO4] in the mixture prevents solidification of the product resulting from reaction of [C2mim][OAc] and CO2. • Density and viscosity studies of the mixture of ionic liquids also lead to synergies, in particular at low temperatures. - Abstract: Ionic liquids have attracted great interest recently as the basis of a potential alternative technology for the capture of carbon dioxide. Beyond the inherent tunability of properties of individual ionic liquids, a further strategy in optimising the ionic liquid sorbent for this application is the use of mixtures of ‘pure’ ionic liquids. Some ionic liquids absorb CO2 physically, whereas others do so chemically. Both mechanisms of absorption present advantages and disadvantages for a CO2 capture process operating in a continuous regime. In this work, a mixture of 1-ethyl-3-methylimidazolium acetate (an ionic liquid that reacts chemically with CO2) and 1-ethyl-3-methylimidazolium ethylsulfate (an ionic liquid that absorbs CO2 only through a physical mechanism) was investigated for the absorption of CO2 as a function of temperature and at pressures up to 17 bar. The absorption/desorption studies were complemented by the characterisation of thermal and physical properties of the mixture of ionic liquids, which provide extra information on the interactions at a molecular level, and are also critical for the assessment of its suitability for a proposed process and for the subsequent process design

  6. The phase transition of the first order in the critical region of the gas-liquid system

    Directory of Open Access Journals (Sweden)

    I.R. Yukhnovskii

    2014-12-01

    Full Text Available This is a summarising investigation of the events of the phase transition of the first order that occur in the critical region below the liquid-gas critical point. The grand partition function has been completely integrated in the phase-space of the collective variables. The basic density measure is the quartic one. It has the form of the exponent function with the first, second, third and fourth degree of the collective variables. The problem has been reduced to the Ising model in an external field, the role of which is played by the generalised chemical potential μ*. The line μ*(η =0, where η is the density, is the line of the phase transition. We consider the isothermal compression of the gas till the point where the phase transition on the line μ*(η =0 is reached. When the path of the pressing reaches the line μ* =0 in the gas medium, a droplet of liquid springs up. The work for its formation is obtained, the surface-tension energy is calculated. On the line μ* =0 we have a two-phase system: the gas and the liquid (the droplet one. The equality of the gas and of the liquid chemical potentials is proved. The process of pressing is going on. But the pressure inside the system has stopped, two fixed densities have arisen: one for the gas-phase ηG=ηc(1-d/2 and the other for the liquid-phase ηL=ηc(1+d/2 (symmetrically to the rectlinear diameter, where ηc=0.13044 is the critical density. Starting from that moment the external pressure works as a latent work of pressure. Its value is obtained. As a result, the gas-phase disappears and the whole system turns into liquid. The jump of the density is equal to ηc d, where d=(D/2G1/2 ~ τν/2. D and G are coefficients of the Hamiltonian in the last cell connected with the renormalisation-group symmetry. The equation of state is written.

  7. Research of Characteristics of Gas-liquid Two-phase Pressure Drop in Microreactor

    Directory of Open Access Journals (Sweden)

    Li Dan

    2015-01-01

    Full Text Available With the research system of nitrogen and deionized water, this paper researches the pressure drop of gas-liquid two-phase flow in the circular microchannel with an inner diameter which is respectively 0.9mm and 0.5mm, analyzes the effect of microchannel diameter on gas-liquid two-phase frictional pressure drop in the microchannel reactor, and compares with the result of frictional pressure drop and the predicting result of divided-phase flow pattern. The result shows that, the gas-liquid two-phase frictional pressure drop in the microchannel significantly increases with the decreasing microchannel diameter; Lockhart-Martinelli relationship in divided-phase flow pattern can preferably predict the gas-liquid two-phase frictional pressure drop in the microchannel, but the Tabular constant needs to be corrected.

  8. Effects of Ni addition on liquid phase separation and giant magnetoresistance of Cu-Co alloys

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The effects of Ni addition on the liquid phase separation and giant magnetoresistance (GMR) of Cu-Co alloys were discussed. The results reveal that Ni addition can partially restrain the liquid phase separation of Cu-Co alloys, resulting in a decrease of volume fraction for the Co-rich particles separated from the liquid phase and in refined microstructures. The composition analyses indicate that Ni is dissolved in both the Co-rich and the Cu-rich phases, but Ni content in the Co-rich phase is much higher than that in the Cu matrix. At the same time, Ni addition enhance the solubility between Cu and Co, especially Cu in Co solid solution. Ni alloying into Cu-Co alloys can fully prevent the liquid phase separation during melt spinning, which is very beneficial to improve GMR of Cu-Co alloys.

  9. Chemical soil investigation report for the Weldon Spring Chemical Plant/Raffinate Pits, Phase II

    International Nuclear Information System (INIS)

    This report presents data and interpretations from the Phase II Chemical Soil Investigation at the Weldon Spring Chemical Plant/Raffinate Pits. This investigation was performed to provide data in support of the Remedial Investigation and Baseline Risk Assessment. The investigation consisted of both biased and unbiased sampling programs designed to detect contamination from previous operations. Very small amounts of nitroaromatic compound contamination were detected in former ordnance production areas. Metals and inorganic anion contamination was observed in numerous locations related to both explosives and uranium production. Small amounts of semi-volatile organic, pesticide, and PCB contamination were also detected. No volatile organic contamination was observed. The data collected in this investigation was of sufficient quality and quantity to characterize the on-site chemical soil contamination. Additional investigations may be required to support remedial design. 14 refs., 3 figs., 8 tabs

  10. Heat transfer by gas-liquid mixture in forced turbulent flow with weak vaporization of the liquid phase (1962)

    International Nuclear Information System (INIS)

    The present study deals with measures of heat transfer and pressure drop in two-phase liquid flow. The stream is of annular dispersed type, obtained by introducing a small quantity of liquid in a gas turbulent flow. The heat transfer experiments are performed without vaporization of the liquid phase. A notable improvement of the heat transfer coefficient of such a stream is observed, compared with a gas-alone or liquid-alone flow. The improvement concerning the gas-alone is of about 20 when it is compared with the same gas Reynolds's number, of about 8 when it is compared with the same total mass flow rate. A hydrodynamic study of the flow pattern lets us know the original structure of the flow, and allows to foresee the experimental results by means of a simplified theory. (authors)

  11. Chromatographic sample collection from two-phase (gas+liquid) flows.

    Science.gov (United States)

    Bruno, Thomas J; Windom, Bret C

    2011-12-01

    A particularly challenging sample presentation in analytical chemistry is a flowing stream that consists of both a gas and liquid phase, combined with the common situation in which a reliable analysis is needed for both phases, separately. In these cases, the vapor and liquid must be physically separated (without change to either), before the individual phases can be collected and analyzed. It is not possible to analyze two-phase flows otherwise. Although the two phases are at equilibrium, it is imperative that no liquid contaminate the vapor, and no vapor be entrained in the liquid at a given temperature and pressure. In this paper, we describe a simple on-line device that can individually separate and collect the vapor and liquid phases of a two-phase flow. The apparatus, which we call P(2)SC, uses an adaptation of the branch point separator, with vapor collection done downstream in a metal bellows. The liquid collection is done in a length of Teflon tube. The separated vapor and liquid phases are then easily transferred into any desired analytical instrument with a syringe, although any sample introduction method, such as a valve, could be used as well. We discuss the application of this device with a stream of thermally stressed rocket kerosene. PMID:22036084

  12. Microstructured Films Formed on Liquid Substrates via Initiated Chemical Vapor Deposition of Cross-Linked Polymers.

    Science.gov (United States)

    Bradley, Laura C; Gupta, Malancha

    2015-07-28

    We studied the formation of microstructured films at liquid surfaces via vapor phase polymerization of cross-linked polymers. The films were composed of micron-sized coral-like structures that originate at the liquid-vapor interface and extend vertically. The growth mechanism of the microstructures was determined to be simultaneous aggregation of the polymer on the liquid surface and wetting of the liquid on the growing aggregates. We demonstrated that we can increase the height of the microstructures and increase the surface roughness of the films by either decreasing the liquid viscosity or decreasing the polymer deposition rate. Our vapor phase method can be extended to synthesize functional, free-standing copolymer microstructured thin films for potential applications in tissue engineering, electrolyte membranes, and separations. PMID:26176742

  13. Application of hollow fiber liquid phase microextraction and dispersive liquid–liquid microextraction techniques in analytical toxicology

    OpenAIRE

    Vahid Sharifi; Ali Abbasi; Anahita Nosrati

    2016-01-01

    The recent developments in hollow fiber liquid phase microextraction and dispersive liquid–liquid microextraction are reviewed. Applications of these newly emerging developments in extraction and preconcentration of a vast category of compounds including heavy metals, pesticides, pharmaceuticals and abused drugs in complex matrices (environmental and biological matrices) are reviewed and discussed. The new developments in these techniques including the use of solvents lighter than water, ioni...

  14. Images reveal that atmospheric particles can undergo liquid–liquid phase separations

    OpenAIRE

    You, Yuan; Renbaum-Wolff, Lindsay; Carreras-Sospedra, Marc; Hanna, Sarah J.; Hiranuma, Naruki; Kamal, Saeid; Smith, Mackenzie L.; Zhang, Xiaolu; Weber, Rodney J.; Shilling, John E.; Dabdub, Donald; Martin, Scot T.; Bertram, Allan K.

    2012-01-01

    A large fraction of submicron atmospheric aerosol particles contains both organic material and inorganic salts. As the relative humidity cycles in the atmosphere and the water content of the particles correspondingly changes, these mixed particles can undergo a range of phase transitions, possibly including liquid–liquid phase separation. If liquid–liquid phase separation occurs, the gas-particle partitioning of atmospheric semivolatile organic compounds, the scattering and absorption of sola...

  15. Liquid-solid phase extraction of rare earth chlorides by oil sulfoxides

    International Nuclear Information System (INIS)

    Liquid - solid phase extraction of rare earth chlorides by oil sulfoxides is studied. It is determined that during extraction of anhydrous rare earth chlorides organic phase is enriched by heavy lanthanides. During extraction of crystal hydrates (H2O:M>5) it enriched by light lanthanides and separation factor increases with temperature growth. It is pointed out that solvent nature does not offer essential effect on isolation of chlorides of d- and f-elements during liquid - solid phase extraction

  16. Liquid-phase processing of fast pyrolysis bio-oil using platinum/HZSM-5 catalyst

    Science.gov (United States)

    Santos, Bjorn Sanchez

    Recent developments in converting biomass to bio-chemicals and liquid fuels provide a promising sight to an emerging biofuels industry. Biomass can be converted to energy via thermochemical and biochemical pathways. Thermal degradation processes include liquefaction, gasification, and pyrolysis. Among these biomass technologies, pyrolysis (i.e. a thermochemical conversion process of any organic material in the absence of oxygen) has gained more attention because of its simplicity in design, construction and operation. This research study focuses on comparative assessment of two types of pyrolysis processes and catalytic upgrading of bio-oil for production of transportation fuel intermediates. Slow and fast pyrolysis processes were compared for their respective product yields and properties. Slow pyrolysis bio-oil displayed fossil fuel-like properties, although low yields limit the process making it uneconomically feasible. Fast pyrolysis, on the other hand, show high yields but produces relatively less quality bio-oil. Catalytic transformation of the high-boiling fraction (HBF) of the crude bio-oil from fast pyrolysis was therefore evaluated by performing liquid-phase reactions at moderate temperatures using Pt/HZSM-5 catalyst. High yields of upgraded bio-oils along with improved heating values and reduced oxygen contents were obtained at a reaction temperature of 200°C and ethanol/HBF ratio of 3:1. Better quality, however, was observed at 240 °C even though reaction temperature has no significant effect on coke deposition. The addition of ethanol in the feed has greatly attenuated coke deposition in the catalyst. Major reactions observed are esterification, catalytic cracking, and reforming. Overall mass and energy balances in the conversion of energy sorghum biomass to produce a liquid fuel intermediate obtained sixteen percent (16 wt.%) of the biomass ending up as liquid fuel intermediate, while containing 26% of its initial energy.

  17. 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.

  18. Two phase flow of liquids in a narrow gap: Phase interference and hysteresis

    Science.gov (United States)

    Raza, Salim; Hejazi, S. Hossein; Gates, Ian D.

    2016-07-01

    Co-current flow of two immiscible liquids, such as oil and water in a planar fracture, exhibits nonlinear structures which become important in many natural and engineering systems such as subsurface flows, multiphase flows in lubrication joints, and coating flows. In this context, co-current flow of oil and water with variable rates is experimentally studied in a Hele-Shaw cell, various flow regimes are classified, and relative permeabilities for the phases are analysed thoroughly. Similar to multiphase pipe flows, multiphase flow in planar gaps shows various flow regimes, each having different flow rate/pressure gradient behaviour. As well as recovering the known results in the immiscible displacements in Hele-Shaw cell where the fluid-fluid interface remains stable/unstable for favorable/adverse viscosity ratios, it is found that the co-current flow of two fluids with different viscosities results in three distinct flow regimes. Before breakthrough of non-wetting phase, i.e, water, a "linear displacement" flow regime initially establishes at very low water injection rates. This stable movement turns into a "fingering advancement" flow regime at high water flow rates and Saffman-Taylor instability develops normal to the direction of the flow. After the breakthrough, a "droplet formation" flow regime is identified where the droplets of wetting phase, oil, are trapped in the water phase. For subsurface flow applications, we quantify these regimes through relative permeability curves. It is reported that as the water flow rate increases, the relative permeabilities and flow channels become smooth and regular. This behaviour of relative permeability and saturations shows dominance of capillary forces at low flow rates and viscous forces at higher flow rates. Variable injection rates provide the interface structures for both drainage and imbibition process, where the wetting phase saturation decreases and increases respectively. It is shown that relative permeability

  19. Chemical Potential Calculations In Dense Liquids Using Metadynamics

    CERN Document Server

    Perego, Claudio; Parrinello, Michele

    2016-01-01

    The calculation of chemical potential has traditionally been a challenge in atomistic simulations. One of the most used approaches is Widom's insertion method in which the chemical potential is calculated by periodically attempting to insert an extra particle in the system. In dense systems this method fails since the insertion probability is very low. In this paper we show that in a homogeneous fluid the insertion probability can be increased using metadynamics. We test our method on a supercooled high density binary Lennard-Jones fluid. We find that we can obtain efficiently converged results even when Widom's method fails.

  20. Rapid removal of nitrobenzene in a three-phase ozone loaded system with gas-liquid-liquid

    Science.gov (United States)

    Li, Shiyin; Zhu, Jiangpeng; Wang, Guoxiang; Ni, Lixiao; Zhang, Yong; Green, Christopher T.

    2015-01-01

    This study explores the removal rate of nitrobenzene (NB) using a new gas-liquid-liquid (G-L-L) three-phase ozone loaded system consisting of a gaseous ozone, an aqueous solvent phase, and a fluorinated solvent phase (perfluorodecalin, or FDC). The removal rate of NB was quantified in relation to six factors including 1) initial pH, 2) initial NB dosage, 3) gaseous ozone dosage, 4) free radical scavenger, 5) FDC pre-aerated gaseous ozone, and 6) reuse of FDC. The NB removal rate is positively affected by the first three factors. Compared with the conventional gas-liquid (water) (G-L) two-phase ozonation system, the free radical scavenger (tertiary butyl alcohol) has much less influence on the removal rate of NB in the G-L-L system. The FDC loaded ozone acts as an ozone reservoir and serves as the main reactive phase in the G-L-L three-phase system. The reuse of FDC has little influence on the removal rate of NB. These experimental results suggest that the oxidation efficiency of ozonation in the G-L-L three-phase system is better than that in the conventional G-L two-phase system.

  1. Purge and trap method to determine alpha factors of VOC liquid-phase mass transfer coefficients

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A theoretical approach and laboratory practice of determining the alpha factors of volatile organic compound (VOC) liquid-phase mass transfer coefficients are present in this study.Using Purge Trap Concentrator, VOC spiked water samples are purged by high-purity nitrogen in the laboratory, the VOC liquid-phase mass transfer rate constants under the laboratory conditions are then obtained by observing the variation of VOCs purged out of the water with the purge time.The alpha factors of VOC liquid-phase mass transfer coefficients are calculated as the ratios of the liquid-phase mass transfer rate constants in real water samples to their counterparts in pure water under the same experimental conditions. This direct and fast approach is easy to control in the laboratory, and would benefit mutual comparison among researchers, so might be useful for thestudy of VOC mass transfer across the liquid-gas interface.

  2. Computer Simulations of Simple Liquids with Tetrahedral Local Order : the Supercooled Liquid, Solids and Phase Transitions

    OpenAIRE

    Elenius, Måns

    2009-01-01

    The understanding of complex condensed matter systems is an area of intense study. In this thesis, some properties of simple liquids with strong preference for tetrahedral local ordering are explored. These liquids are amenable to supercooling, and give complex crystalline structures on eventual crystallisation. All liquids studied are simple, monatomic and are similar to real metallic liquids. The vibrational density of states of a glass created in simulation is calculated. We show a corresp...

  3. Chiral liquid crystals: the vestigial chiral phases of T, O, I matter

    Science.gov (United States)

    Nissinen, Jaakko; Liu, Ke; Slager, Robert-Jan; Wu, Kai; Zaanen, Jan

    We show how chiral order develops in vestigial isotropic phases of T , O and I liquid crystalline systems in three dimensions. The liquid crystal phases are realized in a lattice model of orientational degrees of freedom with point group symmetries G ⊂ O (3) , represented as O (3) -rotors coupled to G gauge fields. The model incorporates also disclinations via the gauge fields, features an ordered nematic phase with unbroken G rotations at low temperatures and a high temperature isotropic liquid phase. We observe an intermediate phase with spontaneous chirality but isotropic SO (3) symmetry (a liquid) for the gauge groups T, O, and I, the proper symmetry groups of the tetrahedron, cube and icosahedron, respectively. For the other subgroups of SO (3) , Cn <= ∞ and Dn <= ∞, there is generically only a single phase transition from the nematic phase to the isotropic liquid. We discuss the nature of the phase transitions and conditions under which the chiral phase is stabilized by the nematic order parameter fluctuations. The nature of the vestigial chiral phase is reminiscent of the so-called Ising nematic phase in iron based superconductors. Research supported by the Netherlands foundation for Fundamental Research of Matter (FOM).

  4. Analysis of two phase mass transfer by logarithmic driving force based on chemical thermodynamics

    International Nuclear Information System (INIS)

    In the Purex solvent extraction process in the reprocessing of spent fuel, the concentration of separated composition such as U changes continuously from very high condition to trace level. Also in most cases, water phase and organic phase continuously come in contact by counter flow operation. In this research, by the method of circulating organic phase between single liquid drop column and mixing tank, the extraction behavior of Nd and nitric acid in H2O-NaNO3/HNO3-Nd(NO3)3-100% TBP system was traced continuously, and the results of measurement and analysis are reported. The experimental equipment and the experimental condition are shown. As the driving force for two-phase mass transfer, that having chemical thermodynamic basis was introduced. It is considered that this driving force is effective for the kinetic analysis of mass transfer phenomena. Hereafter, it is necessary to confirm the more strict treatment using activity and the applicability to two-phase mass transfer phenomena. (K.I.)

  5. A review of air–ice chemical and physical interactions (AICI): liquids, quasi-liquids, and solids in snow

    OpenAIRE

    T. Bartels-Rausch; Jacobi, H.-W.; T. F. Kahan; Thomas, J L; Thomson, E. S.; J. P. D. Abbatt; M. Ammann; Blackford, J. R.; Bluhm, H.; Boxe, C.; Domine, F.; Frey, M. M.; Gladich, I.; Guzmán, M. I.; Heger, D.

    2014-01-01

    Snow in the environment acts as a host to rich chemistry and provides a matrix for physical exchange of contaminants within the ecosystem. The goal of this review is to summarise the current state of knowledge of physical processes and chemical reactivity in surface snow with relevance to polar regions. It focuses on a description of impurities in distinct compartments present in surface snow, such as snow crystals, grain boundaries, crystal surfaces, and liquid parts. It em...

  6. Alkyl-Based Surfactants at a Liquid Mercury Surface: Computer Simulation of Structure, Self-Assembly, and Phase Behavior.

    Science.gov (United States)

    Iakovlev, Anton; Bedrov, Dmitry; Müller, Marcus

    2016-04-21

    Self-assembled organic films on liquid metals feature a very rich phase behavior, which qualitatively differs from the one on crystalline metals. In contrast to conventional crystalline supports, self-assembled alkylthiol monolayers on liquid metals possess a considerably higher degree of molecular order, thus enabling much more robust metal-molecule-semiconductor couplings for organic electronics applications. Yet, compared to crystalline substrates, the self-assembly of organic surfactants on liquid metals has been studied to a much lesser extent. In this Letter we report the first of its kind molecular simulation investigation of alkyl-based surfactants on a liquid mercury surface. The focus of our investigation is the surfactant conformations as a function of surface coverage and surfactant type. First, we consider normal alkanes because these systems set the basis for simulations of all other organic surfactants on liquid mercury. Subsequently, we proceed with the discussion of alkylthiols that are the most frequently used surfactants in the surface science of hybrid organometallic interfaces. Our results indicate a layering transition of normal alkanes as well as alkylthiols from an essentially bare substrate to a completely filled monolayer of laying molecules. As the surface coverage increases further, we observe a partial wetting of the laying monolayer by the bulk phase of alkanes. In the case of alkylthiols, we clearly see the coexistence of molecules in laying-down and standing-up conformations, in which the sulfur headgroups of the thiols are chemically bound to mercury. In the standing-up phase, the headgroups form an oblique lattice. For the first time we were able to explicitly characterize the molecular-scale structure and transitions between phases of alkyl-based surfactants and to demonstrate how the presence of a thiol headgroup qualitatively changes the phase equilibrium and structure in these systems. The observed phenomena are consistent with

  7. Physically and chemically stable ionic liquid-infused textured surfaces showing excellent dynamic omniphobicity

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, Daniel F.; Urata, Chihiro; Masheder, Benjamin; Dunderdale, Gary J.; Hozumi, Atsushi, E-mail: a.hozumi@aist.go.jp [National Institute of Advanced Industrial Science and Technology (AIST), 2266-98, Anagahora, Shimo-Shidami, Moriyama-ku, Nagoya, Aichi 463-8560 (Japan); Yagihashi, Makoto [Nagoya Municipal Industrial Research Institute, Rokuban, Atsuta-ku, Nagoya 456-0058 (Japan)

    2014-05-01

    A fluorinated and hydrophobic ionic liquid (IL), 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide, effectively served as an advantageous lubricating liquid for the preparation of physically and chemically stable omniphobic surfaces based on slippery liquid-infused porous surfaces. Here, we used particulate microstructures as supports, prepared by the chemical vapor deposition of 1,3,5,7-tetramethylcyclotetrasiloxane and subsequent surface modification with (3-aminopropyl)triethoxysilane. Confirmed by SEM and contact angle measurements, the resulting IL-infused microtextured surfaces are smooth and not only water but also various low surface tension liquids can easily slide off at low substrate tilt angles of <5°, even after exposure to high temperature, vacuum, and UV irradiation.

  8. Experimental analysis on adjusting performance of vapor-liquid two-phase flow controller

    Institute of Scientific and Technical Information of China (English)

    LI Hui-jun; TU Shan

    2006-01-01

    The vapor-liquid self-adjusting controller is an innovative automatic regulating valve. In order to ensure adjusted objects run safely and economically, the controller automatically adjusts the liquid flux to keep liquid level at a required level according to physical properties of vapor-liquid two-phase fluid. The adjusting mechanics, the controller' s performance and influencing factors of its stability have been analyzed in this paper. The theoretical analysis and successful applications have demonstrated this controller can keep the liquid level steady with good performance. The actual application in industry has shown that the controller can satisfactorily meet the requirement of industrial production and has wide application areas.

  9. Liquid phase sintering, II: Computer study of skeletal settling and solid phase extrication in a microgravity environment

    Directory of Open Access Journals (Sweden)

    Nikolić Z.S.

    2008-01-01

    Full Text Available A two-dimensional numerical method based on the Brownian motion model and on the Densification model for simulation of liquid phase sintering in microgravity environment will be developed. Both models will be based on domain topology (two-dimensional particle representation and control volume methodology and on three submodels for domain translation, solid skeleton formation and domain extrication. This method will be tested in order to conduct a study of diffusion phenomena and microgravitational effects on microstructural evolution influenced by skeletal settling combined with solid-phase extrication during liquid phase sintering of porous W-Ni system.

  10. Chemical and biological stability of solvent refined coal liquids

    Energy Technology Data Exchange (ETDEWEB)

    Wright, C.W.; Weimer, W.C.

    1984-01-01

    Stability studies performed on seventeen SRC samples in boiling point from ambient to 850/sup 0/F showed that the major chemical composition of the materials as monitored by high resolution gas chromatography did not change under the storage conditions of the repository, which were 4/sup 0/C, in inert containers, under a nitrogen atmosphere, in the dark. Samples were monitored after two years of storage. It was also found from microbial mutagenicity studies that after four years in the repository there was no significant change in the biological activity of any of the SRC materials. Samples stored under various parameters of air versus nitrogen atmosphere and ambient light versus darkness at room temperature and -20/sup 0/C for one year showed there was no significant differences in the chemical composition of any of the samples. There was evidence, however, that trace components such as amino-PAH degraded at room temperature, in the light, under an air atmosphere since the microbial mutagenicity of samples stored under these conditions for one year decreased significantly. Both the chemical composition and mutagenicity of FOB samples changed when stored diluted in methylene chloride, in the light, under an air atmosphere at room temperature. After one year of storage under these conditions, the microbial mutagenicity was eliminated. Storage of SRC-II FOB at increased temperatures of 60/sup 0/C and 100/sup 0/C showed significant changes in chemical composition due to volatility effects. The microbial mutagenicity of the FOB samples was completely eliminated after storage at 60/sup 0/C for 32 weeks and 100/sup 0/C for 26 weeks. It appears that the amino-PAH and phenolic materials are the most susceptible components to degradation in the complex SRC materials. 23 references, 29 figures, 50 tables.

  11. Surface effects on photopolymerization induced anisotropic phase separation in liquid crystal and polymer composites

    International Nuclear Information System (INIS)

    The surface effects on the anisotropic phase separation in photopolymerization induced phase separation of liquid crystal and polymer composites have been studied. It was found that the surface interaction between the substrate and the prepolymer and/or liquid crystal plays a crucial role in anisotropic phase separation. A theoretical model is suggested to describe the surface effects by adapting a phenomenological free energy approach. The formation of polymer layer in the presence of surface effects can be understood as competition between entropic flow and surface directed flow of polymer and liquid crystal

  12. Gasification and Ionization of Chemically Complex Liquids for FRC Injection

    Science.gov (United States)

    Holmes, Michael; Hill, Carrie

    2014-10-01

    Ion thrusters provide reliable and efficient spacecraft propulsion but are limited to noble gas propellants to limit chemical attack of components. However, thrusters based on Field Reversed Configuration (FRC) plasmas are becoming a reality. High beta compact-toroids are generated within an FRC thruster and then expelled to provide thrust. The closed field lines restrict the plasma from attacking thruster components. More convenient propellants such as water are therefore possible. The FRC thruster would generate a series of compact-toroids (plasmoids) to develop continuous spacecraft thrust. Each plasmoid ejection would empty the discharge region. The feed system would then refill the discharge region with partially ionized gas for the next discharge. The ionization part of this feed system is the subject of this paper. The question is how to produce a uniform, chemically complex, ionized gas within the discharge region that optimizes compact-toroid formation? We will be measuring chemical state, ionization state, and uniformity as the propellant enters the discharge region.

  13. Ionic Liquids and Cellulose: Dissolution, Chemical Modification and Preparation of New Cellulosic Materials

    Directory of Open Access Journals (Sweden)

    Mehmet Isik

    2014-07-01

    Full Text Available Due to its abundance and a wide range of beneficial physical and chemical properties, cellulose has become very popular in order to produce materials for various applications. This review summarizes the recent advances in the development of new cellulose materials and technologies using ionic liquids. Dissolution of cellulose in ionic liquids has been used to develop new processing technologies, cellulose functionalization methods and new cellulose materials including blends, composites, fibers and ion gels.

  14. Phase coexistence properties of liquid mercury: a simulation study

    Institute of Scientific and Technical Information of China (English)

    Jean-Louis Bretonnet; Jean-Marc Bomont

    2006-01-01

    The thermophysical properties of expanded liquid mercury have been investigated along the liquid-vapor coexis tence curve by using Monte Carlo and Molecular Dynamic simulations. For the purpose, an empirical state dependent interatomic potential for the region of dense metallic liquid is used, while the state dependence is not necessary near the critical point. In order to test the validity of this potential, we determine the surface layering and the sound velocity, two properties very sensitive to the choice of the potential. Our results are in quite good agreement with other theoretical results and to the experimental data available in the literature.

  15. Liquid Phase Sintering of Boron-Containing Powder Metallurgy Steel with Chromium and Carbon

    Science.gov (United States)

    Wu, Ming-Wei; Fan, Yu-Chi; Huang, Her-Yueh; Cai, Wen-Zhang

    2015-11-01

    Liquid phase sintering is an effective method to improve the densification of powder metallurgy materials. Boron is an excellent alloying element for liquid phase sintering of Fe-based materials. However, the roles of chromium and carbon, and particularly that of the former, on liquid phase sintering are still undetermined. This study demonstrated the effects of chromium and carbon on the microstructure, elemental distribution, boride structure, liquid formation, and densification of Fe-B-Cr and Fe-B-Cr-C steels during liquid phase sintering. The results showed that steels with 0.5 wt pct C densify faster than those without 0.5 wt pct C. Moreover, although only one liquid phase forms in Fe-B-Cr steel, adding 0.5 wt pct C reduces the formation temperature of the liquid phase by about 50 K (°C) and facilitates the formation of an additional liquid, resulting in better densification at 1473 K (1200 °C). In both Fe-B-Cr and Fe-B-Cr-C steels, increasing the chromium content from 1.5 to 3 wt pct raises the temperature of liquid formation by about 10 K (°C). Thermodynamic simulations and experimental results demonstrated that carbon atoms dissolved in austenite facilitate the eutectic reaction and reduce the formation temperature of the liquid phase. In contrast, both chromium and molybdenum atoms dissolved in austenite delay the eutectic reaction. Furthermore, the 3Cr-0.5Mo additive in the Fe-0.4B steel does not change the typical boride structure of M2B. With the addition of 0.5 wt pct C, the crystal structure is completely transformed from M2B boride to M3(B,C) boro-carbide.

  16. New methods and materials for solid phase extraction and high performance liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Dumont, P.J.

    1996-04-23

    This paper describes methods for solid phase extraction and high performance liquid chromatography (HPLC). The following are described: Effects of Resin Sulfonation on the Retention of Polar Organic Compounds in Solid Phase Extraction; Ion-Chromatographic Separation of Alkali Metals In Non-Aqueous Solvents; Cation-Exchange Chromatography in Non-Aqueous Solvents; and Silicalite As a Stationary Phase For HPLC.

  17. Trade-offs to obtain phase-only modulation with a twisted nematic liquid crystal display

    OpenAIRE

    Márquez Ruiz, Andrés; Gallego Rico, Sergi; Méndez Alcaraz, David Israel; Álvarez López, Mariela Lázara; Fernández Varó, Elena; Ortuño Sánchez, Manuel; Neipp López, Cristian; Beléndez Vázquez, Augusto; Pascual Villalobos, Inmaculada

    2007-01-01

    Phase-only modulation using liquid crystal displays (LCDs) is very interesting for many applications (optical signal processing, holographic data storage, ...), however, in general they offer a limited phase modulation depth. In this paper we show various alternatives in order to enhance the phase modulation depth.

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

    International Nuclear Information System (INIS)

    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/Dh = 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)

  19. Study of chemical thermodynamic equilibrium of liquid sodium-hydrogen system

    International Nuclear Information System (INIS)

    The study of the thermodynamic equilibrium of the liquid sodium-hydrogen system is carried out on the basis of chemical engineering thermodynamics. The relationship between the hydrogen partial pressure above the surface of liquid sodium and hydrogen concentration in liquid sodium is presented. The quantitative dependence of the Sieverts constant on the temperature is obtained from above. And the experimental data of the Sieverts constant from some references are analyzed. Moreover, the temperature dependence of hydrogen solubility in sodium is given, and the comparison with the experimental data is made

  20. Mass transfer in liquid phase catalytic exchange column of trickle bed type

    International Nuclear Information System (INIS)

    The mechanism of mass transfer in a liquid phase catalytic exchange column was discussed for a trickle bed type. A new model has been proposed on the basis of this mass transfer mechanism; and several problems for the previous reported models were pointed out in the derivation of the model. An overall rate equation was first derived from the vapor-hydrogen exchange in the model. The mass transfer for the vapor-hydrogen exchange was decomposed to the following three steps: the mass transfer in a gas boundary layer on a catalyst particle; the mass transfer within the pores in the catalyst; and the chemical reaction on the surface of the catalyst. The water-vapor scrubbing process was considered as a series of the mass transfers in gas and liquid boundary layers on the wetted surfaces of the catalyst and packings or wall of the column. Significant subjects to be studied were proposed from the viewpoint of the validity of the model and the optimization of the column. (author)

  1. Proton beam lithography in negative tone liquid phase PDMS polymer resist

    Science.gov (United States)

    Huszank, Robert; Rajta, István; Cserháti, Csaba

    2015-04-01

    In this work we investigated the applicability of liquid PDMS polymer as a negative resist material for direct proton beam writing technique. We irradiated the polymer in liquid phase, spin-coated on different substrate materials creating various microstructures. PDMS pre-polymer was cross-linked just by PBW. As the cross-linking process increases, the irradiated area becomes more solid. The rate of the solidification strongly depends on the deposited ion dose. The effects of fluence, beam current, substrate type and developer solvent was investigated. Furthermore, at the irradiated areas the adhesion, the wettability and Young's modulus also changes due to the chemical change of the PDMS polymer. This effect makes the possibility to form microstructures in PDMS with tunable adhesion and wettability properties. In practical viewpoint, the PDMS resist can also have some advantages compared to other resists such as easy stripping, very fast developing (as the un-cross-linked PDMS is soluble in many organic solvents), not sensitive to light, high current or high fluence.

  2. Proton beam lithography in negative tone liquid phase PDMS polymer resist

    International Nuclear Information System (INIS)

    In this work we investigated the applicability of liquid PDMS polymer as a negative resist material for direct proton beam writing technique. We irradiated the polymer in liquid phase, spin-coated on different substrate materials creating various microstructures. PDMS pre-polymer was cross-linked just by PBW. As the cross-linking process increases, the irradiated area becomes more solid. The rate of the solidification strongly depends on the deposited ion dose. The effects of fluence, beam current, substrate type and developer solvent was investigated. Furthermore, at the irradiated areas the adhesion, the wettability and Young’s modulus also changes due to the chemical change of the PDMS polymer. This effect makes the possibility to form microstructures in PDMS with tunable adhesion and wettability properties. In practical viewpoint, the PDMS resist can also have some advantages compared to other resists such as easy stripping, very fast developing (as the un-cross-linked PDMS is soluble in many organic solvents), not sensitive to light, high current or high fluence

  3. Template-mediated synthesis of periodic membranes for improved liquid-phase separations

    Energy Technology Data Exchange (ETDEWEB)

    Groger, H. [American Research Corp. of Virginia, Radford, VA (United States)

    1997-10-01

    Solid/liquid separations of particulates in waste streams will benefit from design and development of ultrafiltration (UF) membranes with uniform, tailorable pore size and chemical, thermal, and mechanical stability. Such membranes will perform solid/liquid separations with high selectivity, permeance, lifetime, and low operating costs. Existing organic and inorganic membrane materials do not adequately meet all these requirements. An innovative solution to the need for improved inorganic membranes is the application of mesoporous ceramics with narrow pore-size distributions and tailorable pore size (1.5 to 10 nm) that have recently been shown to form with the use of organic surfactant molecules and surfactant assemblies as removable templates. This series of porous ceramics, designated MCM-41, consists of silica or aluminosilicates distinguished by periodic arrays of uniform channels. In this Phase I Small Business Innovation Research program, American Research Corporation of Virginia will demonstrate the use of supported MCM-41 thin films deposited by a proprietary technique, as UF membranes. Technical objectives include deposition in thin, defect-free periodic mesoporous MCM-41 membranes on porous supports; measurement of membrane separation factors, permeance, and fouling; and measurement of membrane lifetime as part of an engineering and economic analysis.

  4. Effective interactions between concentration fluctuations and charge transfer in chemically ordering liquid alloys

    International Nuclear Information System (INIS)

    The correlations between long-wavelength fluctuations of concentration in a liquid binary alloy are determined by a balance between an elastic strain free energy and an Ornstein-Zernike effective interaction. The latter is extracted from thermodynamic data in the case of the Li-Pb system, which is well known to chemically order with stoichiometric composition corresponding to Li4Pb. Strong attractive interactions between concentration fluctuations near the composition of chemical ordering originate from electronic charge transfer, which is estimated from the electron-ion partial structure factors as functions of composition in the liquid alloy. (author). 20 refs, 2 figs

  5. A polarization-independent liquid crystal phase modulation using polymer-network liquid crystals in a 90° twisted cell

    Science.gov (United States)

    Lin, Yi-Hsin; Chen, Ming-Syuan; Lin, Wei-Chih; Tsou, Yu-Shih

    2012-07-01

    A polarization-independent liquid crystal phase modulation using polymer-network liquid crystals in a 90° twisted cell (T-PNLC) is demonstrated. T-PNLC consists of three layers. Liquid crystal (LC) directors in the two layers near glass substrates are orthogonal to each other and those two layers modulate two eigen-polarizations of an incident light. As a result, two eigen-polarizations of an incident light experience the same phase shift. In the middle layer, LC directors are perpendicular to the glass substrate and contribute no phase shift. The phase shift of T-PNLC is electrically tunable and polarization-independent. T-PNLC does not require any bias voltage for operation. The phase shift is 0.28 π rad for the voltage of 30 Vrms. By measuring and analyzing the optical phase shift of T-PNLC at the oblique incidence of transverse magnetic wave, the pretilt angle of LC directors and the effective thickness of three layers are obtained and discussed. The potential applications are spatial light modulators, laser beam steering, and micro-lens arrays.

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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 (τ3) and intensity of formation (I3). 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)

  8. Adaptive micro-optical phase modulators based on liquid crystal technology

    OpenAIRE

    Algorri Genaro, José Francisco

    2015-01-01

    This thesis began with the project “Advanced Devices of Liquid Crystal and Electroluminescent Organic Diodes. Hybrid Applications for 3D Vision” funded by the Spanish government. The goal of this project was the development of optical devices to achieve 3D vision in portable devices without glasses or external elements. In order to achieve the goals of this project, solutions based on liquid crystal are considered. Specifically, adaptive micro-optical phase modulators based on liquid crystal ...

  9. Phase Diagrams in Chemical Engineering: Application to Distillation and Solvent Extraction

    OpenAIRE

    Coquelet, Christophe; Ramjugernath, Deresh

    2012-01-01

    Chapter 19Published under CC BY 3.0 licenseAvailable from: http://www.intechopen.com/books/advances-in-chemical-engineering/phase-diagrams-in-chemical-engineering-example-of-distillation International audience A phase diagram in physical chemistry and chemical engineering is a graphical representation showing distinct phases which are in thermodynamic equilibrium. Since these equilibrium relationships are dependent on the pressure, temperature, and composition of the system, a phase dia...

  10. Electrically tunable refractive index in the dark conglomerate phase of a bent-core liquid crystal

    Science.gov (United States)

    Nagaraj, M.; Görtz, V.; Goodby, J. W.; Gleeson, H. F.

    2014-01-01

    Here we report an electrically tunable refractive index observed in an isotropic liquid crystal phase known as the dark conglomerate (DC) phase. This unusual change in the refractive index which has not been reported before in the DC phase of other bent-core liquid crystals occurs because of a series of electric-field-driven transformations that take place in the DC phase of the studied bent-core liquid crystal. These transformations give rise to a decrease in the refractive index of the system, when an electric field is applied across the device, and no change in the birefringence is seen during such behavior. The electro-optic phenomenon is described in detail and the possibility of exploiting this for a number of liquid crystal based device applications is discussed.

  11. 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...

  12. Light-Weight, Low-Cost, Single-Phase, Liquid-Cooled Cold Plate (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Narumanchi, S.

    2013-07-01

    This presentation, 'Light-Weight, Low-Cost, Single-Phase Liquid-Cooled Cold Plate,' directly addresses program goals of increased power density, specific power, and lower cost of power electronics components through improved thermal management.

  13. MODEL-BASED STUDY OF OXIDATION PROCESSES IN A JET ENGINE FUEL LIQUID PHASE

    OpenAIRE

    Orlovskaya, N.; Shupranov, D.; Bezborodov, Yu; Nadeykin, I.

    2009-01-01

    The process of oxidation in hexadecane liquid phase as a conventional model of oil hydrocarbons is investigated. The oxidation product structure is defined by means of Chromatography/Mass Spectrometry.

  14. HIGH PERFORMANCE LIQUID CHROMATOGRAPHIC SEPARATION OF THE ENANTIOMERS OF ORGANOPHOSPHORUS PESTICIDES ON POLYSACCHARIDE CHIRAL STATIONARY PHASES

    Science.gov (United States)

    High-performance liquid chromatographic separation of the individual enantiomers of 12 organophosphorus pesticides (OPs) was obtained on polysaccharide enantioselective HPLC columns using alkane-alcohol mobile phase. The OP pesticides were crotoxyphos, dialifor, fonofos, fenamiph...

  15. 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…

  16. Vapor-liquid (VLE) and liquid-liquid (LLE) phase equilibria calculations for polystyrene plus methyleyclohexane and polystyrene plus cyclohexane solutions

    DEFF Research Database (Denmark)

    Wilczura-Wachnik, H.; Jonsdottir, Svava Osk

    2006-01-01

    This paper presents the vapor-liquid (VLE) and liquid-liquid (LLE) phase equilibria predictions for polystyrene in two theta solvents: cyclohexane and methylcyclohexane. VLE calculations were performed with the Elbro free volume method and a modified version of the PC-SAFT method, as well as with...... three UNIFAC type group contribution models: Entropic Free Volume + UNIFAC VLE 1 coeff., Entropic Free Volume + UNIFAC VLE 2coeff., and Oishi-Prausnitz + UNIFAC VLE 2coeff. Solvent activities were calculated for the polystyrene + cyclohexane and polystyrene + methylcyclohcxane solutions, and compared...

  17. Liquid crystalline polymers

    CERN Document Server

    Wang, Xin-Jiu

    2004-01-01

    This textbook consists of six chapters. The first chapter highlightsthe concept of liquid crystals, including chemical structure, phaseclassification, defect and texture, and continuum theory. It has beencarefully written to meet the needs of readers who do not specializein liquid crystals. The second chapter is related to the theoreticaldescription of liquid crystalline polymers, networks, and gels, whichdeals with subjects such as the formation of liquid crystallinity inthe polymer system, the phase transition and phase diagram, themolecular weight effect, chain conformation, physics proper

  18. Processes for converting biomass-derived feedstocks to chemicals and liquid fuels

    Energy Technology Data Exchange (ETDEWEB)

    Held, Andrew; Woods, Elizabeth; Cortright, Randy; Gray, Matthew

    2016-07-05

    The present invention provides processes, methods, and systems for converting biomass-derived feedstocks to liquid fuels and chemicals. The method generally includes the reaction of a hydrolysate from a biomass deconstruction process with hydrogen and a catalyst to produce a reaction product comprising one of more oxygenated compounds. The process also includes reacting the reaction product with a condensation catalyst to produce C.sub.4+ compounds useful as fuels and chemicals.

  19. A variational approach to the liquid-vapor phase transition for hardcore ions in the bulk and in nanopores

    CERN Document Server

    Loubet, Bastien; Palmeri, John

    2016-01-01

    We employ a field-theoretical variational approach to study the behavior of ionic solutions in the grand canonical ensemble. To describe properly the hardcore interactions between ions, we use a cutoff in Fourier space for the electrostatic contribution of the grand potential and the Carnahan-Starling equation of state with a modified chemical potential for the pressure one. We first calibrate our method by comparing its predictions at room temperature with Monte Carlo results for excess chemical potential and energy. We then validate our approach in the bulk phase by describing the classical "ionic liquid-vapor" phase transition induced by ionic correlations at low temperature, before applying it to electrolytes at room temperature confined to nanopores embedded in a low dielectric medium and coupled to an external reservoir of ions. The ionic concentration in the nanopore is then correctly described from very low bulk concentrations, where dielectric exclusion shifts the transition up to room temperature fo...

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

    DEFF Research Database (Denmark)

    Gonzalez, Lidia; Kostrzewska, Malgorzata; Ma, Baoguang; Li, Li; Hansen, Jens Henrik; Hvilsted, Søren; Skov, Anne Ladegaard

    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...... the silicone oil core wereassessed by TGA.1H-NMR spectroscopy and anextraction method were also used to determine the content of the silicone liquid core in the microcapsules....

  1. 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

  2. Influence of liquid phase on physical properties of the new triphasic bone cement

    OpenAIRE

    A. Ślósarczyk; N. Osypanka; J. Czechowska; Z. Paszkiewicz; A. Zima

    2012-01-01

    Purpose: The aim of this work was to develop a new bone cement based on hydroxyapatite (HAp), βTCP and calcium sulfate hemihydrate (CSH) and to determine the influence of a liquid phase, used for cement pastes preparation, on physical properties of the final implant material.Design/methodology/approach: The powder phase consisting of CSH (60 wt.%) and HAp+ βTCP (40 wt.%) was applied. Composite samples were prepared using distilled water, chitosan and methylcellulose solutions as the liquid ph...

  3. Direct observation of liquid-phase sintering in the system tungsten carbide--cobalt

    Energy Technology Data Exchange (ETDEWEB)

    Froschauer, L.; Fulrath, R.M.

    1976-01-01

    The hot-stage of a scanning electron microscope has been used to observe liquid-phase sintering in the system tungsten carbide-cobalt. Densification behaviour and the mechanism for the first, fast stage of sintering have been determined; the influence of particle size and the amount of liquid phase has been investigated. In all samples the densification kinetics is that of a rearrangement process; direct observation confirmed this result.

  4. The Plastic and Liquid Phases of CCl$_3$Br Studied by Molecular Dynamics Simulations

    CERN Document Server

    Caballero, Nirvana; Carignano, Marcelo; Serra, Pablo

    2013-01-01

    We present a molecular dynamics study of the liquid and plastic crystalline phases of CCl$_3$Br. We investigated the short-range orientational order using a recently developed classification method and we found that both phases behave in a very similar way. The only differences occur at very short molecular separations, which are shown to be very rare. The rotational dynamics was explored using time correlation functions of the molecular bonds. We found that the relaxation dynamics corresponds to an isotropic diffusive mode for the liquid phase, but departs from this behavior as the temperature is decreased and the system transitions into the plastic phase.

  5. 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....

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

    Energy Technology Data Exchange (ETDEWEB)

    Iguchi, Natsuki; Datta, Alokmay; Yoshikawa, Kenichi; Ma Yue, E-mail: alokmaydatta@gmail.co [Department of Physics, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan)

    2009-02-01

    Nematic-isotropic transition is induced in a 5{mu}m '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{mu}m. 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.

  7. Phase field simulation of monotectic transformation for liquid Ni-Cu-Pb alloys

    Institute of Scientific and Technical Information of China (English)

    LUO BingChi; WANG HaiPeng; WEI BingBo

    2009-01-01

    Based on the subregular solution model, the liquid phase separation of ternary (NixCu100-x)50Pb50monotectic alloys is simulated by the phase field method. It is found that if the surface segregation potential is not incorporated, the dynamic morphologies of alloy melt show a transition from disperse microstructure into bicontinuous microstructure with the increase of fluidity parameter. When the sur-face segregation potential is coupled, Pb-rich phase migrates preferentially to the surface of the liquid alloy, and the Ni-rich phase depends on the Pb-rich phase to nucleate. With the extension of the phase separation time, the surface layer is formed through coagulation and growth, and its thickness gradu-ally increases. The Ni-rich phase migrates to the central part, and finally a two-layer core-shell micro-structure is produced. The concentration in the surface layer fluctuates more conspicuously than that inside the bulk phase, which subsequently transfers from the surface to the interior by a wave. The fluid field near the liquid-liquid interface is strong at the beginning of phase separation, and reduces later on. The surface segregation is essential to the formation of the surface layer, concentration profile variation, fluid field distribution and phase separation morphology.

  8. LIQUID-LIQUID PHASE EQUILIBRIUM OF POLYMER SOLUTIONS AND POLYMER BLENDS UNDER POSITIVE AND NEGATIVE PRESSURE

    Institute of Scientific and Technical Information of China (English)

    Attila R.Imre

    2003-01-01

    In this paper we would like to give a brief review about the extensibility of the liquid-liquid locus into the negative pressure region. Negative pressure states are hardly explored; most researchers believe that the pressure scale ends at p = 0.We would like to show that this is not true, thep = 0 point is not a special point for liquids, it can be "easily" crossed. We are going to give a few example, where the extension of liquid-liquid locus for polymer blends and solutions below p = 0 gives us some interesting results, like the merging of UCST and LCST branches in weakly interacting polymer solutions or the reason why most UCST blends exhibit pressure induced immiscibility. Also, we will see what happens with the immiscibility island of aqueous polymer solutions when - reaching the critical molar mass - it "disappears".

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

    International Nuclear Information System (INIS)

    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.)

  10. [Preparation of triterpene saponins from Platycodon grandiflorum by two-dimensional hydrophilic interaction liquid chromatography-reversed phase liquid chromatography].

    Science.gov (United States)

    Xing, Qianqian; Fu, Qing; Jin, Yu; Liang, Xinmiao

    2014-07-01

    A two-dimensional (2-D) preparative liquid chromatography method was developed for the preparation of triterpene saponins from Platycodon grandiflorum using hydrophilic interaction liquid chromatography (HILIC) coupled with reversed phase liquid chromatography (RPLC). At first, the crude extract was obtained from Platycodon grandiflorum by boiled alcohol precipitation. Then, the concentrated crude extracts were continuously pretreated using solid phase extraction (SPE) under reversed-phase and hydrophilic-phase modes to remove the impurities. Subsequently, XAmide column (150 mm x 20 mm, 5 microm) was selected to separate the triterpene saponin constituents under HILIC mode using water and acetonitrile as mobile phases. From 6 min to 25 min, each fraction was collected per minute under time-triggered mode and 20 fractions were collected. The 18th fraction (JG23) was selected for further purification. The column of Atlantis PrepT3 (100 mm x 30 mm, 5 microm) was chosen and two monomeric compounds were obtained. The two compounds with over 90% purity were identified as deapiplatycoside E and platycoside E with mass spectrometry (MS) and nuclear magnetic resonance (NMR). This 2-D HILIC-RPLC method with high orthogonality can be used in the preparation of triterpene saponins from natural products. PMID:25255571

  11. Modeling of liquid phase formation by solid-solid interaction of Zircaloy and AISI 316 Steel

    International Nuclear Information System (INIS)

    Two models were developed in order to describe the eutectic interaction between Zircaloy-4 and AISI 316 stainless steel, in the temperature range 1000 - 1300 C degree. The aim of the models is to simulate what could happen in the nucleus of a power reactor in an eventual transient high temperature accident. Entry data correspond to the instantaneous positions of the Zircaloy-4 / liquid and stainless steel / liquid inter phases, obtained from experimental data. The hypothesis corresponding to the first model are: that the liquid phase growths by diffusion of the main elements of each alloy in the liquid (Fe and Zr), that there is no interaction between these elements during diffusion, that the diffusion or convection in the solid state is not considered, and that volume changes are negligible during fusion and interdiffusion. Concentrations at the solid/liquid inter phases and the effective diffusion coefficients for Zr and Fe in the liquid can be obtained. The model allows to calculate the formation kinetics for the liquid phase as measured by Zr oxide layers of 0, 10, 20 and 50 microns initial width, formed on the Zircaloy in order to simulate the operating conditions of a reactor. Incubation times for the onset of the reaction, observed experimentally in pre-oxidized samples, were calculated taking into account the oxide dissolution. The second model considers diffusion of Fe in Zircaloy since Fe is a fast diffuser in Zr. As in the first model, concentrations at the solid/liquid inter phases as well as the effective diffusion coefficients for Fe and Zr in the liquid, are calculated. The results obtained in this case depend on the Fe concentration at the solid/liquid interphase at the solid Zircaloy side, and on the Fe diffusivity in Zircaloy-4, which was estimated by the Fe diffusivity in Zr. (author)

  12. Aerosol assisted atmospheric pressure chemical vapor deposition of silicon thin films using liquid cyclic hydrosilanes

    International Nuclear Information System (INIS)

    Silicon (Si) thin films were produced using an aerosol assisted atmospheric pressure chemical vapor deposition technique with liquid hydrosilane precursors cyclopentasilane (CPS, Si5H10) and cyclohexasilane (CHS, Si6H12). Thin films were deposited at temperatures between 300 and 500 °C, with maximum observed deposition rates of 55 and 47 nm/s for CPS and CHS, respectively, at 500 °C. Atomic force microscopic analyses of the films depict smooth surfaces with roughness of 4–8 nm. Raman spectroscopic analysis indicates that the Si films deposited at 300 °C and 350 °C consist of a hydrogenated amorphous Si (a-Si:H) phase while the films deposited at 400, 450, and 500 °C are comprised predominantly of a hydrogenated nanocrystalline Si (nc-Si:H) phase. The wide optical bandgaps of 2–2.28 eV for films deposited at 350–400 °C and 1.7–1.8 eV for those deposited at 450–500 °C support the Raman data and depict a transition from a-Si:H to nc-Si:H. Films deposited at 450 oC possess the highest photosensitivity of 102–103 under AM 1.5G illumination. Based on the growth model developed for other silanes, we suggest a mechanism that governs the film growth using CPS and CHS. - Highlights: • Si films via AA-APCVD are realized using cyclopentasilane (CPS) and cyclohexasilane (CHS). • Low activation energies of CPS and CHS allow Si thin films at low temperatures (300 °C). • High growth rates of 47–55 nm/s were obtained at 500 °C • Near device quality Si thin films with 2–3 orders of photosensitivity • Si thin films via AA-APCVD are amenable to continuous roll-to-roll manufacturing

  13. Chemical Behaviour of C11 in Liquid Hydrocarbons

    International Nuclear Information System (INIS)

    Carbon-11 is produced by the C12 (γ, n)Cu11 reaction in the Bremsstrahlung beam of a 70 MeV electron synchrotron. As target materials, liquid hydrocarbons with 5 and 6 carbons have been used, including normal, branched and alicyclic pentanes and hexanes as well as benzene. The behaviour of Cu11 has been studied by gas chromatographic separation of the products, counting the Cu11 in the gas stream in a cell placed in a well-type scintillation counter. In each experiment yields of different products were compared to the yield of acetylene as an internal standard and either to a tantalum monitor or to the total Cu11 produced as measured in the entire sample before separation. The flow counters were calibrated in terms of total Cu11 produced in experiments in which the complete sample was burned to CO2 and passed through a flow counter. Our earlier experiments were concerned only with the gaseous products that have now been well characterized for the various target molecules under different dosage conditions. Current experiments on product molecules similar in size to the target have proved very helpful in deciding on mechanisms for recombination of recoil atoms. Of particular interest is the yield of product with one carbon more than the target,the result of an addition reaction. The location of the additional atom on a target molecule having several types of addition sites gives information regarding the process itself. When the recoil atom is slowed to an energy at which it is possible for a bond to be formed, at least temporarily, the extra energy which the Cu11 atom brings into the system may cause bond rupture elsewhere within the activated complex usually leading to a two-carbon product. If the complex is able to hold together without rupturing, an additional product will result. Thus comparison of the yields of two-carbon compounds, acetylene, ethylene and ethane, and the additional products provides valuable information regarding the energy at which stable

  14. Phase coexistence in thin liquid films stabilized by colloidal particles: equilibrium and non-equilibrium properties

    International Nuclear Information System (INIS)

    Phase equilibria between regions of different thickness in thin liquid films stabilized by colloidal particles are investigated using a quasi-two-dimensional thermodynamic formalism. Appropriate equilibrium conditions for the film tension, normal pressure, and chemical potential of the particles in the film are formulated, and it is shown that the relaxation of these parameters occurs consecutively on three distinct time scales. Film stratification is described quantitatively for a hard-sphere suspension using a Monte-Carlo method to evaluate thermodynamic equations of state. Coexisting phases are determined for systems in constrained- and full-equilibrium states that correspond to different stages of film relaxation. We also evaluated the effective viscosity coefficients for two-dimensional compressional and shear flows of a film and the self and collective mobility coefficients of the stabilizing particles. The hydrodynamic calculations were performed using a multiple-reflection representation of Stokes flow between two free surfaces. In this approach, the particle-laden film is equivalent to a periodic system of spheres with a unit cell that is much smaller in the transverse direction than in the lateral direction. (author)

  15. Structural Analysis of Perfluoropropanoyl Fluoride in the Gas, Liquid, and Solid Phases.

    Science.gov (United States)

    Berrueta Martínez, Yanina; Reuter, Christian G; Vishnevskiy, Yury V; Bava, Yanina B; Picone, A Lorena; Romano, Rosana M; Stammler, Hans-Georg; Neumann, Beate; Mitzel, Norbert W; Della Védova, Carlos O

    2016-04-21

    The coexistence of two conformers in perfluoropropanoyl fluoride, CF3CF2C(O)F, differing in the CC-CF dihedral angle (gauche 85(10)% and anti 15(10)%), has been determined by means of gas-phase electron diffraction (GED). Quantum-chemical calculations performed at the MP2 and B3LYP approximations and cc-pVTZ basis sets reproduce the experimental values with confidence. By contrast, FTIR spectra give no clear evidence for the anti-conformer in the gas phase. Information on this less abundant but stable rotamer is obtained from matrix-isolation/FTIR spectroscopy and liquid Raman spectroscopy. In situ crystallization and single-crystal X-ray diffraction (XRD) data reveal the presence of solely the gauche-conformation in the solid state. A set of intermolecular interactions including C═O···C═O, C-F···F-C, and F···C═O is detected. The nature of bonding and the relative stabilities of gauche- and anti-conformers are explored using natural bond orbitals. PMID:27023801

  16. Poly(l-lactic acid)-modified silica stationary phase for reversed-phase and hydrophilic interaction liquid chromatography

    OpenAIRE

    Ohyama, Kaname; Takasago, Shizuka; Kishikawa, Naoya; Kuroda, Naotaka

    2015-01-01

    Poly(L-lactic acid) is a linear aliphatic thermoplastic polyester that can be produced from renewable resources. A poly(L-lactic acid)-modified silica stationary phase was newly prepared by amide bond reaction between amino groups on aminopropyl silica and carboxylic acid groups at the end of the poly(L-lactic acid) chain. The poly(L-lactic acid)-silica column was characterized in reversed-phase liquid chromatography and hydrophilic interaction liquid chromatography with the use of different ...

  17. Liquid core fibre versus doped sol-gel layered structured fibre for chemical sensing

    Science.gov (United States)

    Canning, John; Huyang, George; Åslund, Mattias L.; Naqshbandi, Masood; Stocks, Danial; Crossley, Maxwell J.

    2010-10-01

    We review recent work on evaluating the performance of a simple porphyrin-based acid sensor using structured fibre technology. Specifically, the same sensor in a multimode liquid core is compared to that in a sol-gel coated structured optical fibre. General implications for fibre chemical sensing are discussed.

  18. High-Performance Liquid Chromatography in the Undergraduate Chemical Engineering Laboratory

    Science.gov (United States)

    Frey, Douglas D.; Guo, Hui; Karnik, Nikhila

    2013-01-01

    This article describes the assembly of a simple, low-cost, high-performance liquid chromatography (HPLC) system and its use in the undergraduate chemical engineering laboratory course to perform simple experiments. By interpreting the results from these experiments students are able to gain significant experience in the general method of…

  19. Calculation of chemical quantities for the radioactive liquid waste treatment facility

    Energy Technology Data Exchange (ETDEWEB)

    Del Signore, John C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); McClenahan, Robert L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2007-03-01

    The Radioactive Liquid Waste Treatment Facility (RLWTF) receives, stores, and treats both low-level and transuranic radioactive liquid wastes (RLW). Treatment of RLW requires the use of different chemicals. Examples include the use of calcium oxide to precipitate metals and radioactive elements from the radioactive liquid waste, and the use of hydrochloric acid to clean membrane filters that are used in the treatment process. The RL WTF is a Hazard Category 2 nuclear facility, as set forth in the LANL Final Safety Analysis Report of October 1995, and a DOE letter of March 11, 1999. A revised safety basis is being prepared for the RLWTF, and will be submitted to the NNSA in early 2007. This set of calculations establishes maximum chemical quantities that will be used in the 2007 safety basis.

  20. Analysis of Developing Gas/liquid Two-Phase Flows

    Energy Technology Data Exchange (ETDEWEB)

    Elena A. Tselishcheva; Michael Z. Podowski; Steven P. Antal; Donna Post Guillen; Matthias Beyer; Dirk Lucas

    2010-06-01

    The goal of this work is to develop a mechanistically based CFD model that can be used to simulate process equipment operating in the churn-turbulent regime. The simulations were performed using a state-of-the-art computational multiphase fluid dynamics code, NPHASE–CMFD [Antal et al,2000]. A complete four-field model, including the continuous liquid field and three dispersed gas fields representing bubbles of different sizes, was first carefully tested for numerical convergence and accuracy, and then used to reproduce the experimental results from the TOPFLOW test facility at Forschungszentrum Dresden-Rossendorf e.V. Institute of Safety Research [Prasser et al,2007]. Good progress has been made in simulating the churn-turbulent flows and comparison the NPHASE-CMFD simulations with TOPFLOW experimental data. The main objective of the paper is to demonstrate capability to predict the evolution of adiabatic churn-turbulent gas/liquid flows. The proposed modelling concept uses transport equations for the continuous liquid field and for dispersed bubble fields [Tselishcheva et al, 2009]. Along with closure laws based on interaction between bubbles and continuous liquid, the effect of height on air density has been included in the model. The figure below presents the developing flow results of the study, namely total void fraction at different axial locations along the TOPFLOW facility test section. The complete model description, as well as results of simulations and validation will be presented in the full paper.

  1. Two-phase stopped-flow measurement of the protonation of tetraphenylporphyrin at the liquid-liquid interface.

    Science.gov (United States)

    Nagatani, H; Watarai, H

    1996-04-01

    The formation rate of the protonated form of tetraphenylporphyrin (TPP) in a dispersed two-phase system composed of dodecane and aqueous trichloroacetic acid (TCA) was studied by means of a stopped-flow method. The protonation reaction took place at the liquid-liquid interface, and the diprotonated TPP (H(2)TPP(2+)) formed was adsorbed there. In order to determine the rate-determining process, changes in absorbance at the absorption maximum wavelengths of TPP and H(2)TPP(2+) were analyzed. The obtained rate constant for the decrease of TPP in the organic phase, 21 ± 2 s(-1), was in agreement with that for the increase of diprotonated TPP at the interface, 20 ± 3 s(-1). The observed rate constants did not show any dependence on concentrations of both TPP and the acid. The experimental results suggested the rate-determining step to be the molecular diffusion process of TPP in the stagnant layer in the organic phase side at the liquid-liquid interface, and the thickness of the stagnant layer was estimated as 1.4 × 10(-4) cm. PMID:21619156

  2. 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%.

  3. Effect of Liquid Phase Additions on Microstructure and Thermal Properties in Copper and Copper-Diamond Composites

    Directory of Open Access Journals (Sweden)

    A. Rape

    2014-01-01

    Full Text Available This study details a new approach to creating copper-diamond composite materials for thermal management applications by using a two-phase (solid-liquid approach in powder metallurgy using Field Assisted Sintering Technology (FAST. Silver-copper alloyed powder at eutectic compositions was used as a nonreactive liquid phase while Cu5Si was used as a reactive liquid phase. Microstructure results are reported favorably comparing the additions of a small amount of liquid phase to pure solid state sintering. Additionally, EDX results indicate that the liquid phase material fills gaps at the interface of the matrix and diamond particle resulting in improved microstructure and density. Thermal conductivity results show that liquid phase additions improve the thermal conductivity of composites compared to composites without any liquid phase, but Si additions cause a severe drop in baseline conductivity.

  4. Separation of Flue Gas Components by SILP (Supported Ionic Liquid-Phase) Absorbers

    DEFF Research Database (Denmark)

    Thomassen, P.; Kunov-Kruse, Andreas Jonas; Mossin, Susanne L.;

    2013-01-01

    Reversible absorption of the flue gas components CO2, NO, NO2 and SO2 has been tested for different ionic liquids (ILs) at different temperatures and flue gas compositions where porous, high surface area carriers have been applied as supports for the ionic liquids to obtain Supported Ionic Liquid....... The results show that CO2, NO and SO2 can be reversible and selective absorbed using different ILs and that Supported Ionic Liquid-Phase (SILP) absorbers are promising materials for industrial flue gas cleaning. Absorption/desorption dynamics can be tuned by temperature, pressure and gas concentration. © 2012...... ECS - The Electrochemical Society...

  5. Two-Dimensional Numerical Simulation of Boiling Two-Phase Flow of Liquid Nitrogen

    Science.gov (United States)

    Ishimoto, Jun; Oike, Mamoru; Kamijo, Kenjiro

    Two-dimensional characteristics of the boiling two-phase flow of liquid nitrogen in a duct flow are numerically investigated to contribute to the further development of new high-performance cryogenic engineering applications. First, the governing equations of the boiling two-phase flow of liquid nitrogen based on the unsteady drift-flux model are presented and several flow characteristics are numerically calculated taking account the effect of cryogenic flow states. Based on the numerical results, a two-dimensional structure of the boiling two-phase flow of liquid nitrogen is shown in detail, and it is found that the phase change of liquid nitrogen occurs in quite a short time interval compared with that of two-phase pressurized water at high temperature. Next, it is clarified that the distributions of pressure and the void fraction in a two-phase flow show a tendency different from those of fluids at room temperature because of the decrease in sound velocity due to large compressibility and the rapid phase change velocity in a cryogenic two-phase mixture flow. According to these numerical results, the fundamental characteristics of the cryogenic two-phase flow are predicted. The numerical results obtained will contribute to advanced cryogenic industrial applications.

  6. Hydrodynamics of Bubble-Wall Collisions in Liquid Phase.

    Czech Academy of Sciences Publication Activity Database

    Zedníková, Mária; Vejražka, Jiří; Růžička, Marek; Drahoš, Jiří

    Bratislava: Slovak Society of Chemical Engineering, 2007 - (Markoš, J.; Štefuca, V.), s. 138 ISBN 978-80-227-2640-5. [3International Conference of Slovak Society of Chemical Engineering /34./. Tatranské Matliare (SK), 21.05.2007-25.05.2007] R&D Projects: GA ČR(CZ) GA104/05/2566; GA ČR GP104/05/P554; GA ČR GP101/05/P229 Institutional research plan: CEZ:AV0Z40720504 Keywords : bubble-wall collision * impact velocity * contact time Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  7. Liquid-liquid phase separation and morphology of internally mixed dicarboxylic acids/ammonium sulfate/water particles

    OpenAIRE

    Song, M.; Marcolli, C.; U. K. Krieger; A. Zuend; Peter, T

    2012-01-01

    Knowledge of the physical state and morphology of internally mixed organic/inorganic aerosol particles is still largely uncertain. To obtain more detailed information on liquid-liquid phase separation (LLPS) and morphology of the particles, we investigated complex mixtures of atmospherically relevant dicarboxylic acids containing 5–7 carbon atoms (C5, C6 and C7) having oxygen-to-carbon atomic ratios (O:C) of 0.80, 0.67, and 0.57, respectively, mixed with ammonium sulfate (AS). With mi...

  8. Liquid-Liquid Equilibria of Aqueous Two-phase Systems Containing Polyethylene Glycol 4000 and Two Different Salts of Ammonium

    Directory of Open Access Journals (Sweden)

    G. Khayati

    2011-02-01

    Full Text Available The aim of this study was to survey on phase diagrams and Liquid-Liquid Equilibrium (LLE data of the aqueous PEG4000 - (NH42HPO4 and PEG4000 - (NH42SO4 systems experimentally at 298.15 K. The salting-out effect was also discussed on the basis of the Gibbs free energy of hydration of ions. The experimental binodal data were satisfactorily correlated with the Merchuk equation. Tie line compositions were correlated using the Othmer-Tobias and Bancroft equations, and the parameters have also reported. Good agreement was obtained with the experimental data with the model equations.

  9. 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)

    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

  10. Chemically selective NMR imaging of a 3-component (solid-solid-liquid) sedimenting system.

    Science.gov (United States)

    Beyea, Steven D; Altobelli, Stephen A; Mondy, Lisa A

    2003-04-01

    A novel magnetic resonance imaging (MRI) technique which resolves the separate components of the evolving vertical concentration profiles of 3-component non-colloidal suspensions is described. This method exploits the sensitivity of MRI to chemical differences between the three phases to directly image the fluid phase and one of the solid phases, with the third phase obtained by subtraction. 19F spin-echo imaging of a polytetrafluoroethylene (PTFE) oil was interlaced with 1H SPRITE imaging of low-density polyethylene (LDPE) particles. The third phase was comprised of borosilicate glass spheres, which were not visible while imaging the PTFE or LDPE phases. The method is demonstrated by performing measurements on 2-phase materials containing only the floating (LDPE) particles, with the results contrasted to the experimental behaviour of the individual phases in the full 3-phase system. All experiments were performed using nearly monodisperse particles, with initial suspension volume fractions, phi(i), of 0.1. PMID:12713970

  11. Chemically and temperature-induced phase transformations of metal vanadates

    Science.gov (United States)

    Patridge, Christopher James

    different individual beta'-Cu xV2O5 nanowires vary widely. Using scanning transmission X-ray microspectroscopy of individual beta'-CuxV2O 5 nanowires, correlations appear to exist between MIT characteristics and the markedly different orbital hybridization of vanadium and oxygen at the O K and V L absorption edges. These comprehensive nanostructure studies hint at the possibility of approaching the incredibly important realm of single-domain measurements which are needed to understand and exploit the intrinsic physical properties of materials. In addition to the bronze MIT studies, the classical MIT material vanadium dioxide, VO2, also shows new properties when scaling down to nanoscale dimensions as well as incorporation of substitutional dopants such as tungsten. X-ray absorption spectroscopy of the dopant local structure suggests an increased symmetry and depairing of V4+-V 4+, which is critical for transition to the lower temperature insulating phase thereby super-cooling the metallic phase to temperatures as low as 254 K. Mechanistic insight and structural changes associated with the intercalation of Li+ are key aspects in understanding and designing useful secondary Li ion batteries. In similarity to the MxV2O 5 studies, another metal vanadate, Ag2VO2PO 4, undergoes phase transformations due to introduction of Li and the vacancy of Ag ions. Employing a comprehensive study on Ag2VO 2PO4 using X-ray absorption spectroscopy, information about chemical state changes and rehybridization of frontier orbitals allows for a more precise understanding of how the material discharges, what, if any, intermediate phases exist during the process, and provides evidence for the posited structural stability at high depths of discharge.

  12. Phase equilibria and modeling of ammonium ionic liquid, C2NTf2, solutions.

    Science.gov (United States)

    Domańska, Urszula; Marciniak, Andrzej; Królikowski, Marek

    2008-01-31

    Novel quaternary ammonium ionic liquid, ethyl(2-hydroxyethyl)dimethylammonium bis(trifluomethylsulfonyl)imide (C2NTf2), has been prepared from N,N-dimethylethanolamine as a substrate. The paper includes a specific basic characterization of the synthesized compound by NMR and the basic thermophysical properties: the melting point, enthalpy of fusion, enthalpy of solid-solid phase transition, glass transition determined by the differential scanning calorimetry (DSC), temperature of decomposition, and water content. The density of the new compound was measured. The solid-liquid or liquid-liquid phase equilibria of binary mixtures containing {C2NTf2+water or an alcohol (propan-1-ol, butan-1-ol, hexan-1-ol, octan-1-ol, decan-1-ol), aromatic hydrocarbons (benzene, toluene), aliphatic hydrocarbons (n-hexane, n-octane), dimethylsulfoxide (DMSO), or tetrahydrofuran (THF)} have been measured by a dynamic method in a wide range of temperatures from 230 to 430 K. These data were correlated by means of the nonrandom two-liquid (NRTL) equation utilizing temperature-dependent parameters derived from the solid-liquid or liquid-liquid equilibrium. From the solubility results, the negative value of the partition coefficient of ionic liquid in binary system octan-1-ol/water (log P) at 298.15 K has been calculated. PMID:18179194

  13. Hydrogenation of nitriles on a well-characterized nickel surface: From surface science studies to liquid phase catalytic activity measurements

    Energy Technology Data Exchange (ETDEWEB)

    Gardin, D.E.

    1993-12-01

    Nitrile hydrogenation is the most commonly used method for preparing diverse amines. This thesis is aimed at the mechanism and factors affecting the performance of Ni-based catalysts in nitrile hydrogenations. Surface science techniques are used to study bonding of nitriles and amines to a Ni(111) surface and to identify surface intermediates. Liquid-phase hydrogenations of cyclohexene and 1-hexene on a Pt foil were carried out successfully. Finally, knowledge about the surface structure, surface chemical bond, dynamics of surface atoms (diffusion, growth), and reactivity of metal surfaces from solid-gas interface studies, is discussed.

  14. Commercial-scale demonstration of the Liquid Phase Methanol (LPMEOH{trademark}) process. Technical progress report No. 1, October 1, 1993--June 30, 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

    The Liquid Phase Methanol (LPMEOH{trademark}) Demonstration Project at Kingsport, Tennessee is a $213.7 million cooperative agreement between the U.S. Department of Energy (DOE) and Air Products and Chemicals, Inc. (Air Products). This document describes major accomplishments in project development for Fiscal Year 1993. The preliminary process hazards review, project safety plan, schedule, and cost management report are included as appendices. The demonstration is sited at the Eastman Chemical Company (Eastman) complex in Kingsport. Air Products and Eastman are working on a partnership agreement which will form the Air Products Liquid Phase Conversion Company, L.P. As a limited partner in the venture, Eastman will own and operate the demonstration unit. The project involves the construction of a 260 tons-per-day (TPD) or 80,000 gallon per day methanol demonstration unit utilizing an existing coal-derived synthesis gas from Eastman. The new equipment consists of synthesis gas feed preparation and compression, liquid phase reactor and auxiliaries, product distillation, and utilities. The technology to be demonstrated was developed by Air Products in a DOE sponsored program that started in 1981. Originally tested at a small, DOE-owned experimental facility in LaPorte, Texas, the LPMEOH{trademark} process offers several advantages over current methods of making methanol. This liquid phase process suspends fine catalyst particles in an inert liquid, forming a slurry. The liquid dissipates heat from the chemical reaction away from the catalyst surface, protecting the catalyst, and allowing the gas-to-methanol reaction to proceed at higher rates. The process is ideally suited to the type of gas produced by modem coal gasifiers. At the Eastman Chemical complex, the technology will be integrated with existing coal gasifiers to demonstrate the commercially important aspects of the operation of the LPMEOH{trademark} Process to produce methanol.

  15. Phase diagram of selectively cross-linked block copolymers shows chemically microstructured gel

    Science.gov (United States)

    von der Heydt, Alice; Zippelius, Annette

    2015-02-01

    We study analytically the intricate phase behavior of cross-linked AB diblock copolymer melts, which can undergo two main phase transitions due to quenched random constraints. Gelation, i.e., spatially random localisation of polymers forming a system-spanning cluster, is driven by increasing the number parameter μ of irreversible, type-selective cross-links between random pairs of A blocks. Self-assembly into a periodic pattern of A/B-rich microdomains (microphase separation) is controlled by the AB incompatibility χ inversely proportional to temperature. Our model aims to capture the system's essential microscopic features, including an ensemble of random networks that reflects spatial correlations at the instant of cross-linking. We identify suitable order parameters and derive a free-energy functional in the spirit of Landau theory that allows us to trace a phase diagram in the plane of μ and χ. Selective cross-links promote microphase separation at higher critical temperatures than in uncross-linked diblock copolymer melts. Microphase separation in the liquid state facilitates gelation, giving rise to a novel gel state whose chemical composition density mirrors the periodic AB pattern.

  16. Phase diagram of selectively cross-linked block copolymers shows chemically microstructured gel.

    Science.gov (United States)

    von der Heydt, Alice; Zippelius, Annette

    2015-02-01

    We study analytically the intricate phase behavior of cross-linked AB diblock copolymer melts, which can undergo two main phase transitions due to quenched random constraints. Gelation, i.e., spatially random localisation of polymers forming a system-spanning cluster, is driven by increasing the number parameter μ of irreversible, type-selective cross-links between random pairs of A blocks. Self-assembly into a periodic pattern of A/B-rich microdomains (microphase separation) is controlled by the AB incompatibility χ inversely proportional to temperature. Our model aims to capture the system's essential microscopic features, including an ensemble of random networks that reflects spatial correlations at the instant of cross-linking. We identify suitable order parameters and derive a free-energy functional in the spirit of Landau theory that allows us to trace a phase diagram in the plane of μ and χ. Selective cross-links promote microphase separation at higher critical temperatures than in uncross-linked diblock copolymer melts. Microphase separation in the liquid state facilitates gelation, giving rise to a novel gel state whose chemical composition density mirrors the periodic AB pattern. PMID:25662662

  17. Two parametric flow measurement in gas-liquid two-phase flow

    Science.gov (United States)

    Chen, Z.; Chen, C.; Xu, Y.; Zhao, Z.

    The importance and current development of two parametric measurement during two-phase flow are briefly reviewed in this paper. Gas-liquid two-phase two parametric metering experiments were conducted by using an oval gear meter and a sharp edged orifice mounted in series in a horizontal pipe. Compressed air and water were used as gas and liquid phases respectively. The correlations, which can be used to predict the total flow rate and volumetric quality of two-phase flow or volumetric flow rate of each phase, have also been proposed in this paper. Comparison of the calculated values of flow rate of each phase from the correlations with the test data showed that the root mean square fractional deviation for gas flow rate is 2.9 percent and for liquid flow rate 4.4 percent. The method proposed in this paper can be used to measure the gas and liquid flow rate in two-phase flow region without having to separate the phases.

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

    International Nuclear Information System (INIS)

    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

  19. STUDY ON THE PHASE TRANSITION KINETICS OF THERMOTROPIC LIQUID CRYSTALLINE AROMATIC-ALIPHATIC COPOLYESTER

    Institute of Scientific and Technical Information of China (English)

    LI Minhui; WANG Xiaogong; LIU Deshan; ZHOU Qixiang

    1991-01-01

    The phase transition kinetics of thermotropic liquid crystalline aromatic-aliphatic regular copolyester:(X) were studied by DSC. By means of Kissinger's method the kinetic equation and parameters including activation energy, rate order and preexponential factor for phase transition from nematic to isotropic were obtained. The activation energy from crystal to nematic was also presented.

  20. Chemical comparisons of liquid fuel produced by thermochemical liquefaction of various biomass materials

    Energy Technology Data Exchange (ETDEWEB)

    Russell, J.A.; Molton, P.M.; Landsman, S.D.

    1980-12-01

    Liquefaction of biomass in aqueous alkali at temperatures up to 350/sup 0/C is an effective way to convert solid wastes into liquid fuels. The liqefaction oils of several forms of biomass differing in proportions of cellulose, hemi-cellulose, lignin, protein, and minerals were studied and their chemical composition compared. It was that the proportions of chemical components varied considerably depending on the type of biomass liquefied. However, all the oils, even those produced from cellulose, had similar chemical characteristics due to the presence of significant quantities of phenols. These phenols are at least partially responsible for the corrosivity and viscosity commonly associated with biomass oils. The differences in chemical component distribution in the various biomass oils might successfully be exploited if the oil is to be used as a chemical feedstock. If the oil is to be used as a fuel, however, then reaction conditions will be a more important consideration than the source of biomass.

  1. Phase separation of monomer in liquid crystal mixtures and surface morphology in polymer-stabilized vertical alignment liquid crystal displays

    Energy Technology Data Exchange (ETDEWEB)

    Lyu, Jae Jin; Lee, Jun Hyup; Kim, Kyeong Hyeon [Development Center, LCD Business, SAMSUNG Electronics Co. LTD., Tangjeong-Myeon, Asan, Chungnam 336-741 (Korea, Republic of); Kikuchi, Hirotsuku; Higuchi, Hiroki [Institute for Materials Chemistry and Engineering, Kyushu University, 6-1 Kasuga-Koen, Kasuga 816-8580 (Japan); Kim, Dae Hyun; Lee, Seung Hee, E-mail: jsquare.lyu@samsung.com, E-mail: lsh1@chonbuk.ac.kr [Department of BIN Fusion Technology and Department of Polymer-Nano Science and Technology, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of)

    2011-08-17

    The polymer-stabilized vertically aligned (PS-VA) liquid crystal display (LCD) driving mode has high potential for manufacturing low power consuming displays due to the higher transmittance and fast response as compared with the existing patterned vertically aligned and multi-domain vertically aligned modes. In this paper we have investigated the reaction mechanisms of monomer-liquid crystal blends to form a surface pre-tilt angle of liquid crystal in vertical alignment LCD associated with a fishbone electrode structure. The observed sizes of polymer bumps formed on the substrates were found to be dependent on the exposed UV wavelength and were almost equal in both top and bottom substrates. When a large UV wavelength was used, the phase separation mechanism of monomer in PS-VA mode was found nearly isotropic rather than anisotropic in contrast to the previous studies.

  2. Some asymmetric thermohydraulic behaviors of liquid metal-gas two-phase MHD flows

    International Nuclear Information System (INIS)

    In this paper magnetohydrodynamic effect on liquid-metal two-phase flow and heat transfer are summarized based on the measurements made by the present author in NaK-nitrogen flow in a vertical round tube in the presence of a transverse magnetic field. This study covered a wide range of two-phase flow patterns from bubbly flow to annular-dispersed flow, including flow pattern observation, measurements of phase distributions, liquid film behavior, and heat transfer coefficient. Particular emphases are directed towards describing asymmetric thermohydraulic structures induced by the applied magnetic field

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

    International Nuclear Information System (INIS)

    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

  4. The spiral phase and the spin liquid state in the t-J-J' model

    International Nuclear Information System (INIS)

    The possible spin liquid state and phase separation are studied in the framework of t-J-J' model (frustrated t-J model) by using the Schwinger boson mean field theory. It is shown that both the doping and quantum fluctuation of spins, which are treated on the same footing, favor the spin liquid state. Away from half-filling, the phase separation is still present for any values of t/J, and J'/J in the case of spin S=1/2, but the tendency to diminish the range of the phase separation is induced due to the quantum fluctuation of spins. (author). 15 refs, 6 figs

  5. Lattice Boltzmann Simulation of 3D Nematic Liquid Crystal near Phase Transition

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jun; TAO Rui-Bao

    2002-01-01

    Phase transition between nematic and isotropic liquid crystal is a very weak first order phase transition.We avoid to use the normal Landau-de Gennes's free energy that reduces a strong first order transition, and set up adata base of free energy calculated by means of Tao-Sheng Lin's extended molecular field theory that can explain theexperiments of the equilibrium properties of nematic liquid crystal very well. Then we use the free energy method oflattice Boltzmann developed by Oxford group to study the phase decomposition, pattern formation in the flow of theliquid crystal near transition temperature.

  6. 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

    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...

  7. Optical phase conjugation in azo-dye doped chiral liquid crystal

    International Nuclear Information System (INIS)

    We report on optical phase conjugation phenomenon observed in chiral nematic liquid crystal showing band gap type Bragg reflection. The phase conjugate to the signal beam is observable only in the small temperature interval when the Bragg condition is fulfilled and only for circularly polarized light. The optical phase conjugation signals were observed at low cw laser light intensities (2, λ = 532 nm). Estimated value of third order optical susceptibility χ(3) = 2.8 × 10-17 m2/V2 is attributed to enhancement due to photoisomerisation of azo-dye (disperse red 1) inducing molecular reorientation process of liquid crystal molecules.

  8. Phase equilibria and liquid phase epitaxy growth of PbSnSeTe lattice matched to PbSe

    Science.gov (United States)

    Mccann, Patrick J.; Fonstad, Clifton G.; Fuchs, Jacob; Feit, Ze'ev

    1987-01-01

    The necessary phase diagram data for growing lattice-matched layers of PbSnSeTe on PbSe are presented. Solid compounds of Pb(1-x)Sn(x)Se(1-y)Te(y) lattice-matched to PbSe were grown from liquid melts consisting of (Pb/1-x/Sn/x/)(1-z)(Se/1-y/Te/y/)(z); phase equilibria data were determined together with liquidus data for values of x(liquid) from 0 to 40 percent and y(liquid) from 0 to 40 percent for temperatures between 450 and 540 C. It was found that relatively large amounts of Te must be added to the melt to achieve lattice matching because of its low segregation coefficient relative to Se. A significant lattice-pulling effect was discovered for the 5-percent Sn case, and a similar effect is expected for the 10- and 20-percent Sn cases.

  9. Anomalous phase sequence in new chiral liquid crystalline materials

    Czech Academy of Sciences Publication Activity Database

    Podoliak, Natalia; Novotná, Vladimíra; Kašpar, Miroslav; Hamplová, Věra; Glogarová, Milada; Pociecha, D.

    2014-01-01

    Roč. 41, č. 2 (2014), s. 176-183. ISSN 0267-8292 R&D Projects: GA ČR GA13-14133S; GA ČR(CZ) GAP204/11/0723 Grant ostatní: AVČR(CZ) M100101211 Institutional support: RVO:68378271 Keywords : chiral chain * lactate unit * TGBA phase * re-entrancy * TGBC phase Subject RIV: JJ - Other Materials Impact factor: 2.486, year: 2014

  10. 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.

  11. Migration of liquid phase from the primary/peritectic interface in a temperature gradient

    Science.gov (United States)

    Peng, Peng; Li, XinZhong; Su, YanQing; Guo, JingJie

    2016-07-01

    The migration of the liquid droplets from the primary α/peritectic β interface at the peritectic temperature TP has been observed and analyzed in a Sn-Ni peritectic alloy. During the isothermal annealing stage of the interrupted directional solidification, a concentration gradient is established across the liquid droplets along the direction of the temperature gradient due to the temperature gradient zone melting. Simultaneous remelting/resolidification at the top/bottom of the liquid droplets by this concentration gradient have been confirmed to lead to migration of these droplets towards higher temperatures. The dependence of the migration distance of the liquid droplets on isothermal annealing time has been well predicted. Furthermore, since the lengths of the liquid droplet are not uniform along the direction of the temperature gradient, the remelting/resolidification rates which are dependent on the local morphology of liquid droplet are different at different local positions of the liquid droplets. It has been demonstrated that the morphology of the liquid droplet was also influenced by the morphologies of the liquid phase themselves. Therefore, the morphology of the liquid droplet itself changes from spherical to some kinds of irregular shapes during its migration.

  12. Transient liquid-phase bonding in the Ni-Al-B system

    Science.gov (United States)

    Campbell, C. E.; Boettinger, W. J.

    2000-11-01

    Transient liquid-phase (TLP) bonding experiments were performed using a Ni-10.3 at. pct Al alloy and a Ni-10 at. pct B filler material, and the results were compared to simulations performed using the finite-difference diffusion code, DICTRA. For the simulations, a thermodynamic assessment of the Ni-Al-B system was used to define the phase diagram and the thermodynamic factors of the diffusion coefficients. Composition-dependent diffusion mobilities were assessed for the ternary system. Predicted liquid widths as functions of time were in good agreement with the experiments. The calculated and experimental Al composition profiles agree in the matrix but not in the liquid. The simulations qualitatively predicted the observed precipitation and later dissolution of the intermetallic τ phase (Ni20Al3B6) in the base material. This research demonstrated the potential for modeling the formation of spurious phases during TLP bonding of practical superalloy systems.

  13. Mica track microfilters applied for the separation of two strongly mixed liquid phases (emulsion)

    International Nuclear Information System (INIS)

    Mica track microfilters are successfully applied to separate two different and strongly mixed liquid phases. The organic and the inorganic phase of the emulsion were 30% tributyl phosphate (TBP) in kerosene and 2 N HNO3 or H2O, respectively. Mica filters with sharp edges (i.e. etched with HF) and having pore sizes of 8 μm to 2 μm are used to get under some well defined conditions a rather complete extraction of the aqueous phase out of the emulsion. The system was calibrated with the pure phases (water as well as TBP in kerosene), and the liquid throughput is shown as a function of the pore size of the filter. The throughput depends mainly on the pore size and not that much on the kind of liquid, it is slightly larger for water as compared to that of TBP in kerosene. (author)

  14. The questions of liquid metal two-phase flow modelling in the FBR core channels

    International Nuclear Information System (INIS)

    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)

  15. Liquid-phase exfoliated graphene: functionalization, characterization, and applications.

    Science.gov (United States)

    Quintana, Mildred; Tapia, Jesús Iván; Prato, Maurizio

    2014-01-01

    The development of chemical strategies to render graphene viable for incorporation into devices is a great challenge. A promising approach is the production of stable graphene dispersions from the exfoliation of graphite in water and organic solvents. The challenges involve the production of a large quantity of graphene sheets with tailored distribution in thickness, size, and shape. In this review, we present some of the recent efforts towards the controlled production of graphene in dispersions. We also describe some of the chemical protocols that have provided insight into the vast organic chemistry of the single atomic plane of graphite. Controlled chemical reactions applied to graphene are expected to significantly improve the design of hierarchical, functional platforms, driving the inclusion of graphene into advanced functional materials forward. PMID:25551061

  16. Liquid-phase exfoliated graphene: functionalization, characterization, and applications

    Directory of Open Access Journals (Sweden)

    Mildred Quintana

    2014-12-01

    Full Text Available The development of chemical strategies to render graphene viable for incorporation into devices is a great challenge. A promising approach is the production of stable graphene dispersions from the exfoliation of graphite in water and organic solvents. The challenges involve the production of a large quantity of graphene sheets with tailored distribution in thickness, size, and shape. In this review, we present some of the recent efforts towards the controlled production of graphene in dispersions. We also describe some of the chemical protocols that have provided insight into the vast organic chemistry of the single atomic plane of graphite. Controlled chemical reactions applied to graphene are expected to significantly improve the design of hierarchical, functional platforms, driving the inclusion of graphene into advanced functional materials forward.

  17. Liquid-liquid transfer phenomena studies coupled with redox reactions: back-extraction of nitrous acid in the presence of scavengers in aqueous phase

    International Nuclear Information System (INIS)

    This work deals with the investigation of redox reaction contribution to the kinetics of liquid-liquid transfer, in relation with PUREX reprocessing of spent nuclear fuel. The chemical system chosen concerns the tripping of nitrous acid from tributylphosphate organic phase into a nitric acid aqueous solution containing an 'anti-nitrous' component, namely hydrazinium nitrate. According to the abundant literature, a major attention is devoted to the very important role of interfacial phenomena on the kinetics of solvent extraction with tributylphosphate. Although, a suitable experimental technique is chosen, using a constant interfacial area cell of the ARMOLLEX-type. Furthermore, the effects of the hydrodynamical and the physico-chemical parameters on the extraction rate led to the identification of the extraction regime nature: diffusional, then chemical limitation. When no 'anti-nitrous' component is used, the diffusional resistance is found to be mainly located in the aqueous diffusion layer. The presence of hydrazinium nitrate into the aqueous solution has an overall accelerating effect on the rate of extraction, related to both a complete suppression of the aqueous diffusional resistance, and a very significant enhancement of the interfacial transfer of the nitrous acid, as a function of hydrazinium concentration. If the first effect could be expected because of the well known fast redox reaction in aqueous phase, the second phenomenon represents a quite original and new result which has never been explored before, to the best of our knowledge. A reaction mechanism is postulated and validated, taking into account the reactive effect of hydrazinium on the interfacial step. In order to support the drawn general patterns, different complementary studies were attempted. When hydroxyl-ammonium nitrate is used, a surprising interfacial transfer blockage is observed, pointing out the extreme performance and specificity of the common hydrazinium component. (author)

  18. Automated screening of reversed-phase stationary phases for small-molecule separations using liquid chromatography with mass spectrometry.

    Science.gov (United States)

    Appulage, Dananjaya K; Wang, Evelyn H; Carroll, Frances; Schug, Kevin A

    2016-05-01

    There are various reversed-phase stationary phases that offer significant differences in selectivity and retention. To investigate different reversed-phase stationary phases (aqueous stable C18 , biphenyl, pentafluorophenyl propyl, and polar-embedded alkyl) in an automated fashion, commercial software and associated hardware for mobile phase and column selection were used in conjunction with liquid chromatography and a triple quadrupole mass spectrometer detector. A model analyte mixture was prepared using a combination of standards from varying classes of analytes (including drugs, drugs of abuse, amino acids, nicotine, and nicotine-like compounds). Chromatographic results revealed diverse variations in selectivity and peak shape. Differences in the elution order of analytes on the polar-embedded alkyl phase for several analytes showed distinct selectivity differences compared to the aqueous C18 phase. The electron-rich pentafluorophenyl propyl phase showed unique selectivity toward protonated amines. The biphenyl phase provided further changes in selectivity relative to C18 with a methanolic phase, but it behaved very similarly to a C18 when an acetonitrile-based mobile phase was evaluated. This study shows the value of rapid column screening as an alternative to excessive mobile phase variation to obtain suitable chromatographic settings for analyte separation. PMID:26959840

  19. Liquid Chromatography in 1982.

    Science.gov (United States)

    Freeman, David H.

    1982-01-01

    Reviews trends in liquid chromatography including apparatus, factors affecting efficient separation of a mixture (peak sharpness and speed), simplified problem-solving, adsorption, bonded phase chromatography, ion selectivity, and size exclusion. The current trend is to control chemical selectivity by the liquid phase. (Author/JN)

  20. Study of phase separation using liquid-gas model of lattice-gas cellular automata

    International Nuclear Information System (INIS)

    This report describes the study of phase separation by the liquid gas model of lattice gas cellular automata. The lattice gas cellular automaton is one model for simulating fluid phenomena which was proposed by Frisch, Hasslacher and Pomeau in 1986. In 1990, Appert and Zaleski added a new long-range interaction to lattice gas cellular automata to construct a model, the liquid-gas model, which could simulate phase separation using lattice-gas cellular automata. Gerits et al formulated the liquid-gas model mathematically using the theory of statistical dynamics in 1993 and explained the mechanism of phase separation in the liquid-gas model using the equation of state. At first this report explains the FHP model of lattice gas cellular automata and derives fluid dynamics equations such as the equation of continuity and the Navier-Stokes equation. Then the equation of state for the liquid-gas model which was derived by Gerits et al is modified by adding the interactions which were proposed by Appert but not considered by Gerits et al. The modified equation of state is verified by the computer simulation using the liquid gas model. The relation between phase separation and the equation of state is discussed. (author)

  1. Enhanced Crude Oil Biodegradation in a Two-liquid Phase Partitioning Bioreactor

    OpenAIRE

    Ismail, Z. Z.; Abdulrazzak, I. A.

    2015-01-01

    The biodegradation of crude oil at relatively high concentrations in an aquatic environment is constrained by the inherent toxicity of crude oil. In this study, a new application of an aqueous- organic two-liquid phase partitioning bioreactor (TLPPB) was developed to degrade high concentrations of crude oil up to 5000 mg L–1. Silicon oil was selected as the sequestering organic phase to control the delivery of crude oil in aqueous phase by absorbing, and subsequently releasing the crude oi...

  2. Dislocation Model for Restacking Phase Transitions in Crystalline-B Liquid Crystals

    OpenAIRE

    Hirth, J. P.; Pershan, Peter S.; Collett, J; Sirota, E.; Sorensen, L. B.

    1984-01-01

    A dislocation-mediated model is presented for restacking phase transitions that have been observed in a variety of lamellar (liquid crystalline) systems. The model explains the existence of nonhexagonal crystalline (smectic)-B phases in terms of dislocation-induced tilting of hexagonally packed layers. Ordered dislocation arrays explain both the symmetry and the amplitude of observed modulations. It is likely that the model will also be applicable to modulated lipid-water phases.

  3. Phase Transition and Separation for Mixture of Liquid He-3 and He-4

    OpenAIRE

    MA, TIAN; Wang, Shouhong

    2008-01-01

    This article introduces a dynamical Ginzburg-Landau phase transition/separation model for the mixture of liquid helium-3 and helium-4, using a unified dynamical Ginzburg-Landau model for equilibrium phase transitions. The analysis of this model leads to three critical length scales L1 < L2 < L3, detailed theoretical phase diagrams and transition properties with different length scales of the container.

  4. On the Existence of Two-Phase Fluid in Good Communication with Liquid Water

    Energy Technology Data Exchange (ETDEWEB)

    Grant, Malcolm A.

    1980-12-16

    It has been argued that wells of high discharge enthalpy (two-phase wells) at Baca must be isolated from communication with an extensive liquid reservoir. It is shown that such communication has existed, and been maintained, during the history of Wairakei and Broadlands fields. Interpretation of downhole measurements in two-phase fields, and the nature of the two-phase reservoir fluid, is also treated.

  5. Reverse phase-high performance liquid chromatographic separation of lighter lanthanides using salicylic acid as eluent

    International Nuclear Information System (INIS)

    Reversed Phase High Performance Liquid Chromatography (RP-HPLC) using salicylic acid as eluent was studied on unmodified reversed phase column to achieve the separation of lighter lanthanides (La, Ce, Pr, Nd and Sm ). Various chromatographic parameters namely concentrations of eluent and modifier, pH of mobile phase etc. were studied systematically to arrive at optimum chromatographic conditions. This methodology provides satisfactorily separation for the lighter lanthanide elements. (author)

  6. Design of chemical treatment unit for radioactive liquid wastes in Serpong nuclear facilities

    International Nuclear Information System (INIS)

    The chemical treatment unit for radioactive liquid wastes arising from nuclear fuel fabrication, radioisotopes production and radiometallurgy facility has been designed. The design of chemical processing unit is based on the characteristics of liquid wastes containing fluors from uranium fluoride conversion process to ammonium uranyl carbonate on the fuel fabrication. The chemical treatment has the following process steps: coagulation-precipitation of fluoride ion by calcium hydroxide coagulant, separation of supernatant solution from sludge, coagulation of remaining fluoride on the supernatant solution by alum, separation of supernatant from sludge, and than precipitation of fluors on the supernatant by polymer resin WWS 116. The processing unit is composed of 3 storage tanks for raw liquid wastes (capacity 1 m3 per tank), 5 storage tanks for chemicals (capacity 0.5 m3 per tank), 2 mixing reactors (capacity 0.5 m3 per reactor), 1 storage tank for supernatant solution (capacity 1 m3), and 1 storage tank for sludge (capacity 1 m3)

  7. Phase behavior of ternary mixtures {aliphatic hydrocarbon + aromatic hydrocarbon + ionic liquid}: Experimental LLE data and their modeling by COSMO-RS

    International Nuclear Information System (INIS)

    Highlights: • Several ionic liquids were studied as solvent to separate aromatic and aliphatic hydrocarbons. • (Liquid + liquid) equilibrium data were experimental determined at T = 298.15 K and p = 1 atm. • Selectivity and solute distribution ratio were calculated. • Experimental data were correlated using NRTL and UNIQUAC thermodynamic models. • COSMO-RS model was applied to predict the (liquid + liquid) equilibrium. - Abstract: Separation of aromatic and aliphatic hydrocarbons is a complex process in the petrochemical industry due to overlapping boiling points and azeotrope formation. In this paper, liquid extraction of aromatic compounds (toluene and ethylbenzene) from aliphatic compounds (hexane and cyclohexene) using ionic liquids (1-butyl-3-methylimidazolium methylsulfate, BMimMSO4, 1-propyl-3-methylimidazolium bis{trifluoromethylsulfonyl}imide, PMimNTf2, and 1-butyl-3-methylimidazolium bis{trifluoromethylsulfonyl}imide, BMimNTf2) as solvent was studied. (Liquid + liquid) equilibrium (ELL) data for the ternary systems {hexane (1) + ethylbenzene (2) + BMimMSO4, or BMimNTf2, or PMimNTf2 (3)}, {hexane (1) + toluene (2) + BMimMSO4 (3)} and {cyclohexene (1) + ethylbenzene (2) + BMimMSO4 (3)} were experimentally determined at T = 298.15 K and atmospheric pressure. Moreover, an analysis of the influence of the structure of each compound on the phase behavior was also carried out. The ability of the studied ILs to separate aromatic from aliphatic compounds was evaluated in terms of the solute distribution ratio, β, and the selectivity, S. The Non Random Two-Liquid (NRTL) and UNIversal QUAsiChemical (UNIQUAC) thermodynamic models were used to correlate the experimental LLE data. Furthermore, the COnductor-like Screening MOdel for Real Solvents (COSMO-RS) was applied to predict the (liquid + liquid) equilibrium. The suitability of this model to describe the phase behavior of the studied mixtures was evaluated comparing the experimental and calculated data

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

    International Nuclear Information System (INIS)

    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 Fe2O3(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)

  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. PMID:25260326

  10. Preparation and mechanical properties of liquid-phase sinterd silicon carbide; Herstellung und mechanische Eigenschaften von fluessigphasengesintertem Siliziumkarbid

    Energy Technology Data Exchange (ETDEWEB)

    Wiedmann, I.

    1998-12-01

    Liquid-phase sintered silicon carbide ceramics, LPS-SiC, were prepared, and the influence of structure and chemical secondary phase composition on the mechanical properties was investigated in order to identify LPS-SiC materials which can be produced reproducibly and with low loss of mass by simple techniques, i.e. without powder bed or encapsulation. Their profile of characteristics should be superior to conventional solid-phase sintered SiC and should be comparable with liquid-phase sintered silicon nitride ceramics. [Deutsch] In der vorliegenden Arbeit wurden fluessigphasengesinterte Siliziumkarbid-Keramiken, LPS-SiC, hergestellt und der Einfluss der Gefuegeausbildung und der chemischen Sekundaerphasenzusammensetzung auf die mechanischen Eigenschaften untersucht. Ziel war es, LPS-SiC-Materialien zu identifizieren, die ohne besonderen Vorkehrungen wie Pulverbett oder Einkapselung reproduzierbar und mit geringem Masseverlust hergestellt werden koennen. Das Eigenschaftsprofil sollte deutlich ueber dem von konventionell festphasengesintertem SiC liegen und vergleichbar zu fluessigphasengesinterten Siliziumnitrid-Keramiken sein. (orig.)

  11. Micellar structures in lyotropic liquid crystals and phase transitions

    Science.gov (United States)

    Saupe, A.; Xu, S. Y.; Plumley, Sulakshana; Zhu, Y. K.; Photinos, P.

    1991-05-01

    The formation of micellar nematics is discussed with emphasis on the transitions between nematic phases and nematic-smectic transitions. Phase diagrams for MTAB/l-decanol/D,O systems show a direct transition between uniaxial nematics. Electrical conductivity and birefringence measurements on a mixture of sodium decylsulfate. 1-decanol, D,O demonstrate, on the other hand, the existence of a biaxial nemantic range that separates the Uniaxial nematics. On a mixture of cesium perflouroctanoate and H 2O the electrical conductivity and rotational viscosity are used to discuss the relevant features of nematic-lamellar-smectic transitions. The formation of elongated ribbon-like micelles at the nematic-smectic transition is suggested. Transitions between different nematic phases in the MTAB system may be connected with a structural change from long micelles with a fairly circular cross section to similar micelles with a more elliptical cross section.

  12. Enantiomeric Separation of Chiral Pesticides by Permethylated β-Cyclodextrin Stationary Phase in Reversed Phase Liquid Chromatography.

    Science.gov (United States)

    Yan, Jin; Zhang, Renke; Wang, Xinru; Wang, Yao; Wang, Dezhen; Zhou, Zhiqiang; Zhu, Wentao

    2016-05-01

    Enantiomeric separation of six chiral pesticides by high-performance liquid chromatography with permethylated β-cyclodextrin (β-PM) chiral stationary phase were tested under reversed phase conditions. The influences of water composition from 10% to 45% in the mobile phase and column temperatures from 0°C to 40°C on the separation were investigated. Baseline separation was obtained for diclofop-methyl, fenoxaprop-ethyl, tebuconazole and triticonazole, and Rs of these pesticides were greater than 1.5. However, etoxazole and lactofen were partially separated in all experiments. PMID:26992448

  13. A liquid/gas phase separator for He-I and He-II

    Science.gov (United States)

    Shirron, P. J.; Zahniser, J. L.; Dipirro, M. J.

    1991-01-01

    A liquid/gas phase separator has been developed which separates both liquid He-I and He-II from their vapor. The phase separator was designed for the Superfluid Helium On Orbit Transfer (SHOOT) Flight Demonstration both to cool the liquid He after launch (at temperatures between 2.8 and 4.3 K) to the operating temperature of 1.4 K and as a low rate vent on orbit to maintain operating temperature. The phase separator is made of high-purity copper disks held apart by 6 micron Kevlar fibers. It works on the principle of conducting heat from within the dewar to vaporize liquid as it is throttled in the slits to efficiently cool the remaining liquid. Laboratory tests have demonstrated perfect phase separation for both He at its saturated vapor pressure from 1.2 to 4.3 K and for He-II at 2.13 K at pressures from 4.6 to 112 kPa. The performance of this phase separator during lab testing as well as expected performance in space is discussed.

  14. Comparative study between gas phase and liquid phase for the production of DMC from methanol and CO2

    Institute of Scientific and Technical Information of China (English)

    Ahmed Aouissi; Salem S. Al-Deyab

    2012-01-01

    Direct synthesis of dimethyl carbonate (DMC) from methanol and carbon dioxide over Co1.5PW12O40 in liquid and in gas phase is investigated.The synthesized catalyst has been characterized by means of FTIR and XRD.Liquid phase experiment results showed that high pressures are favorable for the synthesis of DMC.However,DMC formation is limited by the reaction with co-produced water.DMC selectivity is more strongly dependent on the temperature than on the pressure of CO2.As for the reactions in gas phase,it has been found that both CH3OH conversion and DMC selectivity decreased with increasing temperature,owing to the decomposition of DMC at high temperatures.High temperatures and more amount of Co1.5PW12O40 catalyst favor the formation of dimethoxymethane (DMM) and methyl formate (MF).

  15. Commercial-Scale Demonstration of the Liquid Phase Methanol (LPMEOH(TM)) Process

    Energy Technology Data Exchange (ETDEWEB)

    None

    1997-06-30

    The Liquid Phase Methanol (LPMEOHTM) Demonstration Project at Kingsport, Tennessee, is a $213.7 million cooperative agreement between the U.S. Department of Energy (DOE) and Air Products Liquid Phase Conversion Company, L.P. (the Partnership). Air Products and Chemicals, Inc. (Air Products) and Eastman Chemical Company (Eastman) formed the Partnership to execute the Demonstration Project. The LPMEOIYM Process Demonstration Unit was built at a site located at the Eastman complex in Kingsport. During this quarter, comments from the DOE on the Topical Report "Economic Analysis - LPMEOHTM Process as an Add-on to IGCC for Coproduction" were received. A recommendation to continue with design verification testing for the coproduction of dimethyl ether (DIME) and methanol was made. DME design verification testing studies show the liquid phase DME (LPDME) process will have a significant economic advantage for the coproduction of DME for local markets. An LPDME catalyst system with reasonable long-term activity and stability is being developed. A recommendation document summarizing catalyst targets, experimental results, and the corresponding economics for a commercially successful LPDME catalyst was issued on 30 June 1997. The off-site, product-use test plan was updated in June of 1997. During this quarter, Acurex Environmental Corporation and Air Products screened proposals for this task by the likelihood of the projects to proceed and the timing for the initial methanol requirement. Eight sites from the list have met these criteria. The formal submission of the eight projects for review and concurrence by the DOE will be made during the next reporting period. The site paving and final painting were completed in May of 1997. Start-up activities were completed during the reporting period, and the initial methanol production from the demonstration unit occurred on 02 April 1997. The first extended stable operation at the nameplate capacity of 80,000 gallons per day (260 tons

  16. Hydrogenation of rapeseed oil for production of liquid bio-chemicals

    International Nuclear Information System (INIS)

    Highlights: ► Production of renewable liquid hydrocarbons through rapeseed oil hydrogenation. ► Hydrogenation at lower temperature and lower hydrogen pressures. ► Test of a catalyst commonly employed in petrochemical industry. ► Improve of hydrogenation process viability by decreasing operational costs. ► Analysis of hydrogenated product applications as bio-chemicals. -- Abstract: The main objective of rapeseed oil hydrogenation tests was the production of liquid bio-chemicals to be used as renewable raw material for the production of several chemicals and in chemical synthesis to substitute petroleum derived stuff. As, hydrogenation of vegetable oils is already applied for the production of biofuels, the work done focused in producing aromatic compounds, due to their economic value. The effect of experimental conditions on rapeseed oil hydrogenation was studied, namely, reaction temperature and time with the aim of selecting the most favourable conditions to convert rapeseed oil into liquid valuable bio-chemicals. Rapeseed oil was hydrogenated at a hydrogen initial pressure of 1.10 MPa. Reaction temperature varied in the range from 200 °C to 400 °C, while reaction times between 6 and 180 min were tested. The performance of a commercial cobalt and molybdenum catalyst was also studied. The highest hydrocarbons yields were obtained at the highest temperature and reaction times tested. At a temperature of 400 °C and at the reaction time of 120 min hydrocarbons yield was about 92% in catalyst presence, while in the absence of the catalyst this value decreased to 85%. Hydrocarbons yield was even higher when the reaction time of 180 min was used in the presence of catalyst, as the yield of 97% was observed. At these conditions hydrocarbons formed had a high content of aromatic compounds, around 50%. For this reason, the viscosity values of hydrogenated oils were lower than that established by EN590, which together with hydrogenated liquids composition

  17. Liquid-solid phase transitions in a deformable container

    Czech Academy of Sciences Publication Activity Database

    Krejčí, Pavel; Rocca, E.; Sprekels, J.

    1. Berlin: Springer, 2010 - (Albers, B.), s. 285-300 ISBN 978-3-642-11444-1 Institutional research plan: CEZ:AV0Z10190503 Keywords : phase transition * energy balance * equilibrium state Subject RIV: BA - General Mathematics http://link.springer.com/chapter/10.1007%2F978-3-642-11445-8_22

  18. 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'. PMID:27185959

  19. Functional carbons and carbon nanohybrids for the catalytic conversion of biomass to renewable chemicals in the condensed phase

    Energy Technology Data Exchange (ETDEWEB)

    Matthiesen, John; Hoff, Thomas; Liu, Chi; Pueschel, Charles; Rao, Radhika; Tessonnier, Jean-Philippe

    2014-06-01

    The production of chemicals from lignocellulosic biomass provides opportunities to synthesize chemicals with new functionalities and grow a more sustainable chemical industry. However, new challenges emerge as research transitions from petrochemistry to biorenewable chemistry. Compared to petrochemisty, the selective conversion of biomass-derived carbohydrates requires most catalytic reactions to take place at low temperatures (< 300°C) and in the condensed phase to prevent reactants and products from degrading. The stability of heterogeneous catalysts in liquid water above the normal boiling point represents one of the major challenges to overcome. Herein, we review some of the latest advances in the field with an emphasis on the role of carbon materials and carbon nanohybrids in addressing this challenge.

  20. Functional carbons and carbon nanohybrids for the catalytic conversion of biomass to renewable chemicals in the condensed phase

    Institute of Scientific and Technical Information of China (English)

    John Matthiesen; Thomas Hoff; Chi Liu; Charles Pueschel; Radhika Rao; Jean-Philippe Tessonnier

    2014-01-01

    The production of chemicals from lignocellulosic biomass provides opportunities to synthesize chemicals with new functionalities and grow a more sustainable chemical industry. However, new challenges emerge as research transitions from petrochemistry to biorenewable chemistry. Com-pared to petrochemisty, the selective conversion of biomass-derived carbohydrates requires most catalytic reactions to take place at low temperatures (<300 °C) and in the condensed phase to pre-vent reactants and products from degrading. The stability of heterogeneous catalysts in liquid water above the normal boiling point represents one of the major challenges to overcome. Herein, we review some of the latest advances in the field with an emphasis on the role of carbon materials and carbon nanohybrids in addressing this challenge.

  1. On-line comprehensive two-dimensional normal-phase liquid chromatography×reversed-phase liquid chromatography for preparative isolation of toad venom.

    Science.gov (United States)

    Li, Jia-Fu; Fang, Hua; Yan, Xia; Chang, Fang-Rong; Wu, Zhen; Wu, Yun-Long; Qiu, Ying-Kun

    2016-07-22

    An on-line comprehensive preparative two-dimensional normal-phase liquid chromatography×reversed-phase liquid chromatography (2D NPLC×RPLC) system was constructed with a newly developed vacuum evaporation assisted adsorption (VEAA) interface, allowing fast removal of NPLC solvent in the vacuum condition and successfully solving the solvent incompatibility problem between NPLC and RPLC. The system achieved on-line solvent exchange within the two dimensions and its performance was illustrated by gram-scale isolation of crude extract from the venom of Bufo bufo gargarizans. Within separation time of ∼20h, 19 compounds were obtained with high purity in a single run. With the VEAA interface, the 2D system exhibited apparent advantages in separation efficiency and automation compared with conventional methods, indicating its promising application in the routine separation process for complicated natural products. PMID:27328884

  2. Carbon dioxide corrosion inhibition of N80 carbon steel in single liquid phase and liquid/particle two-phase flow by hydroxyethyl imidazoline derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Liu, X. [State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Road, Shenyang 110016, Liaoning Province (China); Department of Applied Chemistry, Shenyang Institute of Chemical Technology, Shenyang 110142 (China); Zheng, Y.G. [State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Road, Shenyang 110016, Liaoning Province (China); Okafor, P.C. [State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Road, Shenyang 110016, Liaoning Province (China); Department of Pure and Applied Chemistry, University of Calabar, Calabar (Nigeria)

    2009-07-15

    CO{sub 2} corrosion inhibition of N80 steel in liquid single-phase and liquid/particle two-phase flow by 2-undecyl-1-hydroxyethyl imidazoline (HEI-11) and 2-undecyl-1-hydroxyethyl-1-hydroxyethyl quaternary imidazoline (HQI-11) was investigated using weight loss, potentiodynamic polarization, EIS, and scanning electron microscope (SEM) techniques. The results show that the corrosion rate in the absence and presence of the imidazolines is strongly dependent on the flow condition and presence of entrained sand particles. The imidazolines function via a mixed-type corrosion inhibition mechanism. The inhibition efficiencies of the imidazolines followed the trend HQI-11 > HEI-11 in all the systems studied. Inhibition mechanism has been discussed in relation to the polycentric adsorption sites on the imidazoline molecules. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  3. Chemical Investigation of Saponins in Different Parts of Panax notoginseng by Pressurized Liquid Extraction and Liquid Chromatography-Electrospray Ionization-Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Si-Jia Hong

    2012-05-01

    Full Text Available A pressurized liquid extraction (PLE and high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS method was developed for the qualitative determination of saponins in different parts of P. notoginseng, including rhizome, root, fibre root, seed, stem, leaf and flower. The samples were extracted using PLE. The analysis was achieved on a Zorbax SB-C18 column with gradient elution of acetonitrile and 8 mM aqueous ammonium acetate as mobile phase. The mass spectrometer was operated in the negative ion mode using the electrospray ionization, and a collision induced dissociation (CID experiment was also carried out to aid the identification of compounds. Forty one saponins were identified in different parts of P. notoginseng according to the fragmentation patterns and literature reports, among them, 21 saponins were confirmed by comparing the retention time and ESI-MS data with those of standard compounds. The results showed that the chemical characteristics were obviously diverse in different parts of P. notoginseng, which is helpful for pharmacological evaluation and quality control of P. notoginseng.

  4. Partitioning Behavior of Papain in Ionic Liquids-Based Aqueous Two-Phase Systems

    OpenAIRE

    Zhiwen Bai; Yanhong Chao; Meiling Zhang; Changri Han; Wenshuai Zhu; Yonghui Chang; Huaming Li; Yang Sun

    2013-01-01

    This paper attempts to study and optimize the affinity partitioning conditions of papain in an aqueous two-phase system (ATPS). The effect of the amount of ionic liquids (ILs), the concentration of K2HPO4, temperature, pH, and the volume of papain solution were discussed concretely. The optimum conditions were determined as ionic liquid was 1.4 g and K2HPO4 was 1.4 g, the extraction efficiency of papain co...

  5. The clock and control system for the ATLAS Liquid Argon Calorimeter Phase-I upgrade

    International Nuclear Information System (INIS)

    A Liquid-argon Trigger Digitizer Board (LTDB) is being developed to upgrade the ATLAS Liquid Argon Calorimeter Phase-I trigger electronics. The LTDB located at the front end needs to obtain the clock signals and be configured and monitored remotely from the back end. A clock and control system is being developed for the LTDB and the major functions of the system have been evaluated. The design and evaluation of the clock and control system are presented in this paper

  6. Nuclear recoil detection in liquid argon using a two-phase CRAD and DD neutron generator

    International Nuclear Information System (INIS)

    The detection of nuclear recoils in noble liquids using neutron elastic scattering off nuclei is relevant in the field of calibration of rare-event detectors for dark matter search and coherent neutrino-nucleus scattering experiments. We present here the first results on nuclear recoil detection in liquid Ar, using a two-phase Cryogenic Avalanche Detector (CRAD) and DD neutron generator. The technique to select the nuclear recoils for backward neutron scattering has been demonstrated

  7. Self-shielding effect of a single phase liquid xenon detector for direct dark matter search

    OpenAIRE

    Minamino, A.; Abe, K.; Ashie, Y.; Hosaka, J.; Ishihara, K; Kobayashi, K; Koshio, Y.; Mitsuda, C.; Moriyama, S.; Nakahata, M.(University of Tokyo, Institute for Cosmic Ray Research, Kamioka Observatory, Kamioka, Japan); Nakajima, Y; Namba, T.; Ogawa, H.; Sekiya, H.; Shiozawa, M

    2009-01-01

    Liquid xenon is a suitable material for a dark matter search. For future large scale experiments, single phase detectors are attractive due to their simple configuration and scalability. However, in order to reduce backgrounds, they need to fully rely on liquid xenon's self-shielding property. A prototype detector was developed at Kamioka Observatory to establish vertex and energy reconstruction methods and to demonstrate the self-shielding power against gamma rays from outside of the detecto...

  8. Ultrasound and Temperature Study of Non-Equilibrium Phase Transitions in Surface-Bound Liquid Layers

    OpenAIRE

    Shulgin, V. A.

    2012-01-01

    The present research deals with the registration and study of temperature and ultrasound parameters of non-equilibrium phase transitions occurring in the layer "liquid-solid surface" in the process of slow heating and cooling of the medium. Different resistive sensors have been used for taking measurements. As a result there has been discovered a periodic stepped dependence of the registered temperature with jumps ~7.5-13 K in water, water solutions and other liquids. We have studied the cond...

  9. Quantum phase transitions in semi-local quantum liquids

    CERN Document Server

    Iqbal, Nabil; Mezei, Márk

    2011-01-01

    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: (1) 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; (2) a "hybridized" critical point which can be described by a standard Landau-Ginsburg sector of order parameter fluctuations hybridized with a strongly coupled sector; (3) 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...

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

    International Nuclear Information System (INIS)

    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

  11. Theory of phase separation and polarization for dissociated ionic liquids

    CERN Document Server

    Gavish, Nir

    2015-01-01

    Room temperature ionic liquids are attractive to numerous applications and particularly, to renewable energy devices. As solvent free electrolytes, they demonstrate a paramount connection between the material morphology and Coulombic interactions: unlike dilute electrolytes, the electrode/RTIL interface is a product of both electrode polarization and spatiotemporal bulk properties. Yet, theoretical studies have dealt almost exclusively with independent models of morphology and electrokinetics. In this work, we develop a novel Cahn-Hilliard-Poisson type mean-field framework that couples morphological evolution with electrokinetic phenomena. Linear analysis of the model shows that spatially periodic patterns form via a finite wavenumber instability, a property that cannot arise in the currently used Fermi-Poisson-Nernst-Planck equations. Numerical simulations in above one-space dimension, demonstrate that while labyrinthine type patterns develop in the bulk, stripe patterns emerge near charged surfaces. The res...

  12. Method of processing radioactive liquid wastes derived from organic-chemical decontaminating agents

    International Nuclear Information System (INIS)

    Purpose: To process radioactive liquid wastes of organic-chemical decontaminating agents after being used for the decontamination of tanks, pipeways, pumps or like other equipments contaminated with radioactive materials in nuclear power plants. Method: Radioactive liquid wasted derived from decontaminating agents mainly composed of organic acids such as citric acid, formic acid, oxalic acid, hydroxyl acetic acid, ascorbic acid and gluconic acid are at first processed in a filter comprising porous filtering membranes, to eliminate suspended materials containing claddings not dissolved in the liquid wastes. As the porous filtering membranes, hollow thread filtering membranes, ceramic filters, sintered metal membranes, metal mesh filters or the likes may be used, the back-wash type hollow thread porous polymeric membranes being preferred. Then, the organic mateirals are effectively decomposed into gaseous dioxide and water through photolysis while blowing ozone under the irradiation of UV-rays to thereby decrease the amount of radioactive wastes significantly. (Kamimura, M.)

  13. Operation of a GERDA phase I prototype detector in liquid argon and nitrogen

    International Nuclear Information System (INIS)

    A GERDA phase I prototype detector, consisting of a bare non-enriched high-purity (HP) p-type germanium diode mounted in a low mass holder has been operated both in liquid nitrogen and liquid argon. Because of its high density, liquid argon has been selected as cryogenic liquid and shield for GERDA experiment. The testing of this detector assembly has been carried out in the underground detector laboratory at LNGS, and at the detector manufacturer. The best resolution achieved is 2.2 keV FWHM at 1.332 MeV, which is the same as the resolution measured in a standard test cryostat. The long-term measurements with the prototype detector are performed in liquid argon. Up to now, 38 thermal cycles have been carried out with this detector. The operations, measurements and results of the prototype detector testing are summarized. (orig.)

  14. Novel materials and methods for solid-phase extraction and liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Ambrose, D.

    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.

  15. Liquid-gas phase transition in strange hadronic matter with relativistic models

    CERN Document Server

    Torres, James R; Menezes, Débora P

    2015-01-01

    Background: The advent of new dedicated experimental programs on hyperon physics is rapidly boosting the field, and the possibility of synthetizing multiple strange hypernuclei requires the addition of the strangeness degree of freedom to the models dedicated to nuclear structure and nuclear matter studies at low energy. Purpose: We want to settle the influence of strangeness on the nuclear liquid-gas phase transition. Because of the large uncertainties concerning the hyperon sector, we do not aim at a quantitative estimation of the phase diagram but rather at a qualitative description of the phenomenology, as model independent as possible. Method: We analyze the phase diagram of low density matter composed of neutrons, protons and $\\Lambda$ hyperons using a Relativistic Mean Field (RMF) model. We largely explore the parameter space to pin down generic features of the phase transition, and compare the results to ab-initio quantum Monte Carlo calculations. Results: We show that the liquid-gas phase transition ...

  16. Binary Solid-Liquid Phase Diagram of Phenol and t-Butanol: An Undergraduate Physical Chemistry Experiment

    Science.gov (United States)

    Xu, Xinhua; Wang, Xiaogang; Wu, Meifen

    2014-01-01

    The determination of the solid-liquid phase diagram of a binary system is always used as an experiment in the undergraduate physical chemistry laboratory courses. However, most phase diagrams investigated in the lab are simple eutectic ones, despite the fact that complex binary solid-liquid phase diagrams are more common. In this article, the…

  17. Light-enhanced liquid-phase exfoliation and current photoswitching in graphene-azobenzene composites

    Science.gov (United States)

    Döbbelin, Markus; Ciesielski, Artur; Haar, Sébastien; Osella, Silvio; Bruna, Matteo; Minoia, Andrea; Grisanti, Luca; Mosciatti, Thomas; Richard, Fanny; Prasetyanto, Eko Adi; de Cola, Luisa; Palermo, Vincenzo; Mazzaro, Raffaello; Morandi, Vittorio; Lazzaroni, Roberto; Ferrari, Andrea C.; Beljonne, David; Samorì, Paolo

    2016-04-01

    Multifunctional materials can be engineered by combining multiple chemical components, each conferring a well-defined function to the ensemble. Graphene is at the centre of an ever-growing research effort due to its combination of unique properties. Here we show that the large conformational change associated with the trans-cis photochemical isomerization of alkyl-substituted azobenzenes can be used to improve the efficiency of liquid-phase exfoliation of graphite, with the photochromic molecules acting as dispersion-stabilizing agents. We also demonstrate reversible photo-modulated current in two-terminal devices based on graphene-azobenzene composites. We assign this tuneable electrical characteristics to the intercalation of the azobenzene between adjacent graphene layers and the resulting increase in the interlayer distance on (photo)switching from the linear trans-form to the bulky cis-form of the photochromes. These findings pave the way to the development of new optically controlled memories for light-assisted programming and high-sensitive photosensors.

  18. Thermal Diffusivity and Thermal Conductivity of Five Different Steel Alloys in the Solid and Liquid Phases

    Science.gov (United States)

    Wilthan, B.; Schützenhöfer, W.; Pottlacher, G.

    2015-08-01

    The need for characterization of thermophysical properties of steel and nickel-based alloys was addressed in the FFG-Bridge Project 810999 in cooperation with a partner from industry, Böhler Edelstahl GmbH & Co KG. To optimize numerical simulations of production processes, such as remelting or plastic deformation, additional, and more accurate data were necessary for the alloys under investigation. With a fast ohmic pulse heating circuit system, the temperature-dependent specific electrical resistivity, density, and specific heat capacity for a set of five high alloyed steels were measured. Hence, using the Wiedemann-Franz law with a Lorenz number of , the thermal diffusivity and thermal conductivity could be calculated for the solid and liquid phases up to temperatures of 2500 K. This experimental approach is limited by the following requirements for the specimens: they have to be electrically conducting, the melting point has to be high enough for the implemented pyrometric temperature measurement, and one has to be able to draw wires of the material. The latter restriction is technologically challenging with some of the materials being very brittle. For all samples, electrical and temperature signals are recorded and a fast shadowgraph method is used to measure the volume expansion. For each material under investigation, a set of data including the chemical composition, the density at room temperature, solidus and liquidus temperatures, and the change of enthalpy, resistivity, density, thermal conductivity, and thermal diffusivity as a function of temperature is reported.

  19. Liquid phase deposition methods monitoring techniques influence for solid substrates and thin metal oxide films properties

    Directory of Open Access Journals (Sweden)

    A.V. Valiulis

    2007-09-01

    Full Text Available Purpose: Liquid phase deposition (LPD method is a useful method to create thin oxide films from aqueous solutions under ambient conditions. Deposition of ceramic layers on polymers is a technological challenge because of polymer sensitivity to chemicals and high temperature processing.Design/methodology/approach: The work attempts to elucidate the role of the substrate during LPD of TiO2 films by using Kapton with different types of surface treatments.Findings: Was found that small differences in pH, temperature, and solution composition can lead to dramatic differences in the film’s crystallinity, adherence, and growth rate. Thin films are very smooth, uniform with small amount of cracks.Research limitations/implications: Independent of technique and substrate, film thicker than a few hundred nm exhibited cracks, attributed to stresses that result during drying of the film.Originality/value: Techniques for monitoring the surface chemistry of the solid substrate and the deposited ceramic film have been developed.

  20. Conductive polymeric ionic liquids for electroanalysis and solid-phase microextraction.

    Science.gov (United States)

    Young, Joshua A; Zhang, Cheng; Devasurendra, Amila M; Tillekeratne, L M Viranga; Anderson, Jared L; Kirchhoff, Jon R

    2016-03-01

    Three novel electropolymerizable thiophene-based ionic liquids (ILs) were synthesized and characterized as potential candidates for developing selective extraction media for chemical analysis. Electropolymerization of the bis[(trifluoromethyl)sulfonyl]imide ([NTf2](-)) analogs successfully produced uniform polymeric thin-films on macro- and microelectrode substrates from both vinyl and methylimidazolium IL monomer derivatives. The resultant conducting polymer IL (CPIL) films were characterized by electrochemical methods and found to exhibit attractive behavior towards anionic species while simultaneously providing an exclusion barrier toward cationic species. Thermogravimetric analysis of the thiophene-based IL monomers established a high thermal stability, particularly for the methylimidazolium IL, which was stable until temperatures above 350 °C. Subsequently, the methylimidazolium IL was polymerized on 125 μm platinum wires and utilized for the first time as a sorbent coating for headspace solid-phase microextraction (HS-SPME). The sorbent coating was easily prepared in a reproducible manner, provided high thermal stability, and allowed for the gas chromatographic analysis of polar analytes. The normalized response of the poly[thioph-C6MIm][NTf2]-based sorbent coating exhibited higher extraction efficiency compared to an 85 μm polyacrylate fiber and excellent fiber-to-fiber reproducibility. Therefore, the electropolymerizable thiophene-based ILs were found to be viable new materials for the preparation of sorbent coatings for HS-SPME. PMID:26873467