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Sample records for distributed immiscible liquid

  1. APPLICATION OF A LUMPED-PROCESS MATHEMATICAL MODEL TO DISSOLUTION OF NON-UNIFORMLY DISTRIBUTED IMMISCIBLE LIQUID IN HETEROGENEOUS POROUS MEDIA

    PubMed Central

    Marble, J. C.; DiFilippo, E. L.; Zhang, Z.; Tick, G. R.; Brusseau, M. L.

    2010-01-01

    The use of a lumped-process mathematical model to simulate the complete dissolution of immiscible liquid non-uniformly distributed in physically heterogeneous porous-media systems was investigated. The study focused specifically on systems wherein immiscible liquid was poorly accessible to flowing water. Two representative, idealized scenarios were examined, one wherein immiscible liquid at residual saturation exists within a lower-permeability unit residing in a higher-permeability matrix, and one wherein immiscible liquid at higher saturation (a pool) exists within a higher-permeability unit adjacent to a lower-permeability unit. As expected, effluent concentrations were significantly less than aqueous solubility due to dilution and by-pass flow effects. The measured data were simulated with two mathematical models, one based on a simple description of the system and one based on a more complex description. The permeability field and the distribution of the immiscible-liquid zones were represented explicitly in the more complex, distributed-process model. The dissolution rate coefficient in this case represents only the impact of local-scale (and smaller) processes on dissolution, and the parameter values were accordingly obtained from the results of experiments conducted with one-dimensional, homogeneously-packed columns. In contrast, the system was conceptualized as a pseudo-homogeneous medium with immiscible liquid uniformly distributed throughout the system for the simpler, lumped-process model. With this approach, all factors that influence immiscible-liquid dissolution are incorporated into the calibrated dissolution rate coefficient, which in such cases serves as a composite or lumped term. The calibrated dissolution rate coefficients obtained from the simulations conducted with the lumped-process model were approximately two to three orders of magnitude smaller than the independently-determined values used for the simulations conducted with the

  2. Evaporative Mass Transfer Behavior of a Complex Immiscible Liquid

    PubMed Central

    McColl, Colleen M.; Johnson, Gwynn R.; Brusseau, Mark L.

    2010-01-01

    A series of laboratory experiments was conducted with a multiple-component immiscible liquid, collected from the Picillo Farm Superfund Site in Rhode Island, to examine liquid-vapor mass-transfer behavior. The immiscible liquid, which comprises solvents, oils, pesticides, PCBs, paint sludges, explosives, and other compounds, was characterized using gas chromatography and gas chromatography/mass spectrometry to determine mole fractions of selected constituents. Batch experiments were conducted to evaluate equilibrium phase-partitioning behavior. Two sets of air-stripping column studies were conducted to examine the mass-transfer dynamics of five selected target compounds present in the immiscible-liquid mixture. One set of column experiments was designed to represent a system with free-phase immiscible liquid present; the other was designed to represent a system with a residual phase of immiscible liquid. Initial elution behavior of all target components generally appeared to be ideal for both systems, as the initial vapor-phase concentrations were similar to vapor-phase concentrations measured for the batch experiment and those estimated using Raoult’s law (incorporating the immiscible-liquid composition data). Later-stage removal of 1,2-dichlorobenzene appeared to be rate limited for the columns containing free-phase immiscible liquid and no porous medium. Conversely, evaporative mass transfer appeared to be ideal throughout the experiment conducted with immiscible liquid distributed relatively uniformly as a residual phase within a sandy porous medium. PMID:18614196

  3. Measuring Interfacial Tension Between Immiscible Liquids

    NASA Technical Reports Server (NTRS)

    Rashidnia, Nasser; Balasubramaniam, R.; Delsignore, David M.

    1995-01-01

    Glass capillary tube technique measures interfacial tension between two immiscible liquids. Yields useful data over fairly wide range of interfacial tensions, both for pairs of liquids having equal densities and pairs of liquids having unequal densities. Data on interfacial tensions important in diverse industrial chemical applications, including enhanced extraction of oil; printing; processing foods; and manufacture of paper, emulsions, foams, aerosols, detergents, gel encapsulants, coating materials, fertilizers, pesticides, and cosmetics.

  4. Phase separation kinetics in immiscible liquids

    NASA Technical Reports Server (NTRS)

    Sadoway, D. R.

    1986-01-01

    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 imaging 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.

  5. Phase separation kinetics in immiscible liquids

    NASA Technical Reports Server (NTRS)

    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.

  6. Interfacial and gravitational convection in immiscible liquid layers

    NASA Technical Reports Server (NTRS)

    Prakash, A.; Koster, J. N.

    1992-01-01

    Liquid encapsulation of electronic melts is currently being investigated by several materials science research groups. Pertinent fluid dynamics of immiscible liquid layers is the objective of this investigation. First results on convective flow in double liquid layers, in preparation for a spaceflight experiment aboard the International Microgravity Laboratory, IML-2, are discussed.

  7. Process for blending coal with water immiscible liquid

    DOEpatents

    Heavin, Leonard J.; King, Edward E.; Milliron, Dennis L.

    1982-10-26

    A continuous process for blending coal with a water immiscible liquid produces a uniform, pumpable slurry. Pulverized raw feed coal and preferably a coal derived, water immiscible liquid are continuously fed to a blending zone (12 and 18) in which coal particles and liquid are intimately admixed and advanced in substantially plug flow to form a first slurry. The first slurry is withdrawn from the blending zone (12 and 18) and fed to a mixing zone (24) where it is mixed with a hot slurry to form the pumpable slurry. A portion of the pumpable slurry is continuously recycled to the blending zone (12 and 18) for mixing with the feed coal.

  8. Solidification Processing of Immiscible Liquids in the Presence of Applied Ultrasonic Energy

    NASA Technical Reports Server (NTRS)

    Kim, Shinwood; Grugel, R. N.

    2000-01-01

    Uniform microstructural development during solidification of immiscible liquids on Earth is hampered by inherent density differences between the phases. Microgravity processing minimizes settling but segregation still occurs due to gravity independent wetting and coalescence phenomena. Experiments with the transparent organic, metal analogue, succinonitrile-glycerol system were conducted in conjunction with applied ultrasonic energy. The processing parameters associated with this technique have been evaluated in view of optimizing dispersion uniformity. Experimental results to evaluate microstructural phase distributions, based on other liquid-liquid immiscibility systems, will also be presented.

  9. Experimental confirmation of high temperature silicate liquid immiscibility

    NASA Astrophysics Data System (ADS)

    Hou, T.; Veksler, I. V.

    2014-12-01

    The existence of stable, super-liquidus silicate liquid immiscibility at temperatures up to 1200 °C has been proposed for some multicomponent ferrobasaltic-ferroandesitic compositions on the basis of centrifuge experiments (Veksler et al., 2007) but the evidence and interpretation of experimental results were challenged by Philpotts (2008) who argued that the products of centrifuge experiments were metastable phases formed during quenching. Here we report the results of static reverse experiments, which were aimed at resolving the debate. The idea of the reverse experiments was to test miscibility between pre-synthesized pairs of silica-rich and Fe-rich immiscible melts at static conditions and long exposure times. Three pairs of the potentially immiscible compositions were taken from the original study by Veksler et al. (2007) and one more pair was taken from a recent report of liquid immiscibility in the Panzhihua intrusion in China. Experiments were carried out in one-atmosphere gas-mixing furnace (Ar-H2-CO2 gas mixture) at 1150 and 1200 °C and oxygen fugacity corresponding to that of the QFM buffer. Pairs of the silica-rich and Fe-rich starting compositions were loaded in Pt wire loops, fused separately at 1200 °C, and then brought in contact and kept at constant experimental temperature for more than 24 hours. Three pairs of compositions out of four used in this study did not mix. Some temperature-dependent chemical re-equilibration was observed in the Fe-rich melts but, in the cases of immiscibility, two liquids remained compositionally distinct and showed sharp compositional gradients at contacts. One pair of liquids crystallized some tridymite, whereas the other compositions were clearly above liquidus. Overall, the results of the reverse experiments are in good agreement with the earlier centrifugation study and confirm the existence of stable, super-liquids immiscibility in some Fe-rich basaltic-andesitic compositions at temperatures up to 1200

  10. Measurement of interfacial tension of immiscible liquid pairs in microgravity

    NASA Technical Reports Server (NTRS)

    Weinberg, Michael C.; Neilson, George F.; Baertlein, Carl; Subramanian, R. Shankar; Trinh, Eugene H.

    1994-01-01

    A discussion is given of a containerless microgravity experiment aimed at measuring the interfacial tension of immiscible liquid pairs using a compound drop rotation method. The reasons for the failure to execute such experiments in microgravity are described. Also, the results of post-flight analyses used to confirm our arguments are presented.

  11. Electroanalytical Ventures at Nanoscale Interfaces Between Immiscible Liquids

    NASA Astrophysics Data System (ADS)

    Arrigan, Damien W. M.; Liu, Yang

    2016-06-01

    Ion transfer at the interface between immiscible electrolyte solutions offers many benefits to analytical chemistry, including the ability to detect nonredox active ionized analytes, to detect ions whose redox electrochemistry is accompanied by complications, and to separate ions based on electrocontrolled partition. Nanoscale miniaturization of such interfaces brings the benefits of enhanced mass transport, which in turn leads to improved analytical performance in areas such as sensitivity and limits of detection. This review discusses the development of such nanoscale interfaces between immiscible liquids and examines the analytical advances that have been made to date, including prospects for trace detection of ion concentrations.

  12. Electroanalytical Ventures at Nanoscale Interfaces Between Immiscible Liquids.

    PubMed

    Arrigan, Damien W M; Liu, Yang

    2016-06-12

    Ion transfer at the interface between immiscible electrolyte solutions offers many benefits to analytical chemistry, including the ability to detect nonredox active ionized analytes, to detect ions whose redox electrochemistry is accompanied by complications, and to separate ions based on electrocontrolled partition. Nanoscale miniaturization of such interfaces brings the benefits of enhanced mass transport, which in turn leads to improved analytical performance in areas such as sensitivity and limits of detection. This review discusses the development of such nanoscale interfaces between immiscible liquids and examines the analytical advances that have been made to date, including prospects for trace detection of ion concentrations. PMID:27049634

  13. Optical limiting based on liquid-liquid immiscibility

    NASA Astrophysics Data System (ADS)

    Exarhos, Gregory J.; Ferris, Kim F.; Samuels, William D.; Owings, Robert R.

    2003-05-01

    Nonionic surfactants are used to stabilize a dispersed droplet phase in a continuous liquid phase when two immiscible liquids are mixed. As both liquid phases approach the index-matched condition, interfacial scattering is suppressed, and the mixture takes on the characteristics of a Christiansen-Shelyubskii filter. If, in addition, one of the liquids exhibits a substantial nonlinear optical response, then interfacial light scattering can be reversibly turned on when a laser beam incident upon the filter exceeds a critical fluence. To demonstrate this effect, an organic phase (dichloroethane) was dispersed in an aqueous phase containing sodium thiocyanate (NaSCN) using an alkyl end-capped polyethylene glycol ether. Optical limiting was observed through this transparent medium under conditions where the focused second-harmonic output of a Q-Switched Nd:YAG laser was on the order of about 50 mJ/cm2. An open-aperture z-scan technique was used to quantify the limiting behavior. Since the thiocyanate anion is both isostructural and isoelectronic with carbon disulfide which exhibits a large optical nonlinearity, the mechanism of optical limiting is proposed to be associated with a nonlinear shift in the aqueous fluid index of refraction, resulting in an index mismatch between the disparate phases at high laser fluence. Index mismatch between the two phases leads to multiple reflections, loss of coherence, and a significant transmission decrease due to Tyndall scattering. Fundamental studies of such systems are used to verify theoretical predictions of the limiting effect, and aid in the design and development of improved sub nanosecond limiters based upon this optical deflection approach.

  14. Thermocapillary convection in two immiscible liquid layers with free surface

    NASA Technical Reports Server (NTRS)

    Doi, Takao; Koster, Jean N.

    1993-01-01

    Thermocapillary convection is studied in two immiscible liquid layers with one free surface, one liquid/liquid interface, and differential heating applied parallel to the interfaces. An analytical solution is introduced for infinite horizontal layers. The defining parameter for the flow pattern is lambda, the ratio of the temperature coefficient of the interfacial tension to that of the surface tension. Four different flow patterns exist under zero gravity conditions. 'Halt' conditions which halt the fluid motion in the lower encapsulated liquid layer have been found. A numerical experiment is carried out to study effects of vertical end walls on the double layer convection in a 2D cavity. The halt condition obtained from the analytical study is found to be valid in the limit of small Reynolds numbers. The flow in the encapsulated liquid layer can be suppressed substantially.

  15. The role of liquid immiscibility in the genesis of carbonatites — An experimental study

    NASA Astrophysics Data System (ADS)

    Freestone, I. C.; Hamilton, D. L.

    1980-07-01

    The two-liquid field between alkali-carbonate liquids and phonolite or nephelinite magmas from the Oldoinyo Lengai volcano has been determined between 0.7 and 7.6 kb and 900° 1,250° C. The miscibility gap expands with increase in P_{CO_2 } and decrease in temperature. Concomitantly there is a rotation of tie-lines so that the carbonate liquids become richer in CaO. The element distribution between the melts indicates that a carbonate liquid equivalent in composition to Oldoinyo Lengai natrocarbonatite lava would have separated from a phonolitic rather than a nephelinitic magma. CO2-saturated nephelinites coexist with carbonate liquids much richer in CaO than the Lengai carbonatites, but even so these liquids have high alkali concentrations. If the sövites of hypabyssal and plutonic ijolite-carbonatite complexes originated by liquid immiscibility, then large quantities of alkalis have been lost, as is suggested by fenitization and related phenomena. The miscibility gap closes away from Na2O-rich compositions, so that the tendency to exsolve a carbonatite melt is greater in salic than in mafic silicate magmas. The two-liquid field does not approach kimberlitic compositions over the range of pressures studied, suggesting that the globular textures observed in many kimberlite sills and dykes may be the result of processes other than liquid immiscibility at crustal pressures.

  16. MASS-REMOVAL AND MASS-FLUX-REDUCTION BEHAVIOR FOR IDEALIZED SOURCE ZONES WITH HYDRAULICALLY POORLY-ACCESSIBLE IMMISCIBLE LIQUID

    SciTech Connect

    Brusseau, M. L.; Difilippo, Erica L.; marble, justin C.; Oostrom, Mart

    2008-04-01

    A series of flow-cell experiments was conducted to investigate aqueous dissolution and mass-removal behavior for systems wherein immiscible liquid was non-uniformly distributed in physically heterogeneous source zones. The study focused specifically on characterizing the relationship between mass flux reduction and mass removal for systems for which immiscible liquid is poorly accessible to flowing water. Two idealized scenarios were examined, one wherein immiscible liquid at residual saturation exists within a lower-permeability unit residing in a higher-permeability matrix, and one wherein immiscible liquid at higher saturation (a pool) exists within a higher-permeability unit adjacent to a lower-permeability unit. The results showed that significant reductions in mass flux occurred at relatively moderate mass-removal fractions for all systems. Conversely, minimalmass flux reduction occurred until a relatively large fraction of mass (>80%) was removed for the control experiment, which was designed to exhibit ideal mass removal. In general, mass flux reduction was observed to follow an approximately one-to-one relationship with mass removal. Two methods for estimating mass-flux-reduction/mass-removal behavior, one based on system-indicator parameters (ganglia-to-pool ratio) and the other a simple mass-removal function, were used to evaluate the measured data. The results of this study illustrate the impact of poorly accessible immiscible liquid on mass-removal and mass-flux processes, and the difficulties posed for estimating mass-flux-reduction/mass-removal behavior.

  17. Thermodynamic estimation of minor element distribution between immiscible liquids in Fe-Cu-based metal phase generated in melting treatment of municipal solid wastes

    SciTech Connect

    Lu, X.; Nakajima, K.; Sakanakura, H.; Matsubae, K.; Bai, H.; Nagasaka, T.

    2012-06-15

    Graphical abstract: Display Omitted Highlights: Black-Right-Pointing-Pointer Two liquids separation of metal occurs in the melting of municipal solid waste. Black-Right-Pointing-Pointer The distribution of PGMs etc. between two liquid metal phases is studied. Black-Right-Pointing-Pointer Quite simple thermodynamic model is applied to predict the distribution ratio. Black-Right-Pointing-Pointer Au and Ag originated from WEEE are found to be concentrated into Cu-rich phase. - Abstract: Waste electrical and electronic equipment (WEEE) has become an important target in managing material cycles from the viewpoint of not only waste management and control of environmental pollution but also resource conservation. This study investigated the distribution tendency of trace elements in municipal solid waste (MSW) or incinerator ash, including valuable non-ferrous metals (Ni, Co, Cr, Mn, Mo, Ti, V, W, Zr), precious group metals (PGMs) originated from WEEE (Ag, Au, Pd, Pt), and others (Al, B, Pb, Si), between Fe-rich and Cu-rich metal phases by means of simple thermodynamic calculations. Most of the typical alloying elements for steel (Co, Cr, Mo, Nb, Ni, Si, Ti, V, and W) and Rh were preferentially distributed into the Fe-rich phase. PGMs, such as Au, Ag, and Pd, were enriched in the Cu-rich phase, whereas Pt was almost equally distributed into both phases. Since the primary metallurgical processing of Cu is followed by an electrolysis for refining, and since PGMs in crude copper have been industrially recovered from the resulting anode slime, our results indicated that Ag, Au, and Pd could be effectively recovered from MSW if the Cu-rich phase could be selectively collected.

  18. Heat transfer between immiscible liquids enhanced by gas bubbling

    NASA Astrophysics Data System (ADS)

    Greene, G. A.; Schwarz, C. E.; Klages, J.; Klein, J.

    1982-08-01

    The phenomena of core-concrete interactions impact upon containment integrity of light water reactors (LWR) following postulated complete meltdown of the core by containment pressurization, production of combustible gases, and basemat penetration. Experiments were performed with nonreactor materials to investigate one aspect of this problem, heat transfer between overlying immiscible liquids whose interface is disturbed by a transverse non-condensable gas flux emanating from below. Hydrodynamic studies were performed to test a criterion for onset of entrainment due to bubbling through the interface and subsequent heat transfer studies were performed to assess the effect of bubbling on interfacial heat transfer rates, both with and without bubble induced entrainment. Non entraining interfacial heat transfer data with mercury-water/oil fluid pairs were observed to be bounded from below within a factor of two to three by the Szekeley surface renewal heat transfer model.

  19. Solidification Processing of Immiscible Liquids in the Presence of Applied Ultrasonic Energy

    NASA Technical Reports Server (NTRS)

    Grugel, R. N.; Fedoseyev, A. I.; Kim, S.

    2001-01-01

    Uniform microstructural distribution during solidification of immiscible liquids (e.g., oil and water; aluminum and lead) on Earth is hampered by inherent density differences between the phases. Microgravity processing minimizes settling but segregation still occurs due to gravity independent wetting and coalescence phenomena. Experiments with the transparent organic, metal analogue, succinonitrile-glycerol system were conducted in conjunction with applied ultrasonic energy. The processing parameters associated with this technique have been evaluated in view of optimizing dispersion uniformity. Characterization of the experimental results in terms of a modeling effort will also be presented,

  20. Stabilization of liquid foams through the synergistic action of particles and an immiscible liquid.

    PubMed

    Zhang, Yi; Wu, Jie; Wang, Hongzhi; Meredith, J Carson; Behrens, Sven H

    2014-12-01

    Liquid foams are familiar from beer, frothed milk, or bubble baths; foams in general also play important roles in oil recovery, lightweight packaging, and insulation. Here a new class of foams is reported, obtained by frothing a suspension of colloidal particles in the presence of a small amount of an immiscible secondary liquid. A unique aspect of these foams, termed capillary foams, is the particle-mediated spreading of the minority liquid around the gas bubbles. The resulting mixed particle/liquid coating can stabilize bubbles against coalescence even when the particles alone cannot. The coated bubbles are further immobilized by entrapment in a network of excess particles connected by bridges of the minority liquid. Capillary foams were prepared with a diverse set of particle/liquid combinations to demonstrate the generality of the phenomenon. The observed foam stability correlates with the particle affinity for the liquid interface formed by spreading the minority liquid at the bubble surface. PMID:25284445

  1. Silicate liquid immiscibility in isothermal crystallization experiments. [lunar-evolution simulation

    NASA Technical Reports Server (NTRS)

    Longhi, J.

    1990-01-01

    The role of silicate liquid immiscibility (SLI) in the petrogenesis of lunar granites was investigated in experiments in which four glasses were synthesized from reagent-grade oxides and carbonates with the compositions of two of the sets of coexisting liquids reported by Hess et al. (1975): a KREEP basalt derivative and a mare basalt derivative. Isothermal crystallization experiments showed that SLI is a stable phenomenon in residual lunar liquids saturated with plagioclase, and is likely to produce large compositional separations. The results indicate that controlled-cooling-rate experiments of Rutherford et al. (1974), and Hess et al. (1975, 1978) were substantially correct analogs of the natural process of liquid immiscibility.

  2. Hydrogenation with monolith reactor under conditions of immiscible liquid phases

    SciTech Connect

    Nordquist, Andrew Francis; Wilhelm, Frederick Carl; Waller, Francis Joseph; Machado, Reinaldo Mario

    2002-01-01

    The present invention relates to an improved for the hydrogenation of an immiscible mixture of an organic reactant in water. The immiscible mixture can result from the generation of water by the hydrogenation reaction itself or, by the addition of, water to the reactant prior to contact with the catalyst. The improvement resides in effecting the hydrogenation reaction in a monolith catalytic reactor from 100 to 800 cpi, at a superficial velocity of from 0.1 to 2 m/second in the absence of a cosolvent for the immiscible mixture. In a preferred embodiment, the hydrogenation is carried out using a monolith support which has a polymer network/carbon coating onto which a transition metal is deposited.

  3. Thermodynamic estimation of minor element distribution between immiscible liquids in Fe-Cu-based metal phase generated in melting treatment of municipal solid wastes.

    PubMed

    Lu, X; Nakajima, K; Sakanakura, H; Matsubae, K; Bai, H; Nagasaka, T

    2012-06-01

    Waste electrical and electronic equipment (WEEE) has become an important target in managing material cycles from the viewpoint of not only waste management and control of environmental pollution but also resource conservation. This study investigated the distribution tendency of trace elements in municipal solid waste (MSW) or incinerator ash, including valuable non-ferrous metals (Ni, Co, Cr, Mn, Mo, Ti, V, W, Zr), precious group metals (PGMs) originated from WEEE (Ag, Au, Pd, Pt), and others (Al, B, Pb, Si), between Fe-rich and Cu-rich metal phases by means of simple thermodynamic calculations. Most of the typical alloying elements for steel (Co, Cr, Mo, Nb, Ni, Si, Ti, V, and W) and Rh were preferentially distributed into the Fe-rich phase. PGMs, such as Au, Ag, and Pd, were enriched in the Cu-rich phase, whereas Pt was almost equally distributed into both phases. Since the primary metallurgical processing of Cu is followed by an electrolysis for refining, and since PGMs in crude copper have been industrially recovered from the resulting anode slime, our results indicated that Ag, Au, and Pd could be effectively recovered from MSW if the Cu-rich phase could be selectively collected. PMID:22370049

  4. NONIDEAL BEHAVIOR DURING COMPLETE DISSOLUTION OF ORGANIC IMMISCIBLE LIQUID IN NATURAL POROUS MEDIA

    PubMed Central

    Russo, A.E.; Mahal, M.K.; Brusseau, M.L.

    2011-01-01

    Experiments were conducted to investigate the complete dissolution of organic immiscible liquid residing within natural porous media. Organic-liquid dissolution was investigated by conducting experiments with homogeneously packed columns containing a residual saturation of organic liquid (trichloroethene). The porous media used comprised different textures (ranges of particle-size distributions) and organic-carbon contents. The dissolution behavior that was observed for the soil and aquifer sediment systems deviated from the behavior typically observed for systems composed of ideal sands. Specifically, multi-step elution curves were observed, with multiple extended periods of relatively constant contaminant flux. This behavior was more pronounced for the two media with larger particle-size distributions. Conversely, this type of dissolution behavior was not observed for the control system, which consisted of a well-sorted sand. It is hypothesized that the pore-scale configuration of the organic liquid and of the flow field is more complex for the poorly sorted media, and that this greater complexity constrains dissolution dynamics, leading to the observed nonideal behavior. PMID:19643542

  5. Why are blue zhamanshinites blue Liquid immiscibility in an impact melt

    SciTech Connect

    Zolensky, M.E. ); Koeberl, C. )

    1991-05-01

    The authors report here a study of the cause of the coloration of blue zhamanshinites, which are glassy impact melt rocks from the Zhamanshin crater in the USSR. They find that the blue color results from Rayleigh scattering from spherical, 100 nm-diameter inclusions of a separate Ca-Fe-Mg-P-rich silicate glass. These observations can best be explained by the operation of liquid immiscibility in the zhamanshinite melt, and suggest that liquid immiscibility may have a more general role in impactite evolution.

  6. Why are blue zhamanshinites blue? Liquid immiscibility in an impact melt

    NASA Technical Reports Server (NTRS)

    Zolensky, Michael E.; Koeberl, Christian

    1991-01-01

    A study of the cause of the coloration of blue zhamanshinites, which are glassy impact melt rocks from the Zhamanshin crater in the USSR are reported. It is found that the blue color results from Rayleigh scattering from spherical, 100 nm-diameter inclusions of a separate Ca-Fe-Mg-P-rich silicate glass. These observations can best be explained by the operation of liquid immiscibility in the zhamanshinite melt, and suggest that liquid immiscibility may have a more general role in impactite evolution.

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

    NASA Astrophysics Data System (ADS)

    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.

  8. Predicting liquid immiscibility in multicomponent nuclear waste glasses

    SciTech Connect

    Peeler, D.K.; Hrma, P.R.

    1994-04-01

    Taylor`s model for predicting amorphous phase separation in complex, multicomponent systems has been applied to high-level (simulated) radioactive waste glasses at the US Department of Energy`s Hanford site. Taylor`s model is primarily based on additions of modifying cations to a Na{sub 2}O-B{sub 2}O{sub 3}-SiO{sub 2} (NBS) submixture of the multicomponent glass. The position of the submixture relative to the miscibility dome defines the development probability of amorphous phase separation. Although prediction of amorphous phase separation in Hanford glasses (via experimental SEM/TEM analysis) is the primary thrust of this work; reported durability data is also provides limited insight into the composition/durability relationship. Using a modified model similar to Taylor`s, the results indicate that immiscibility may be predicted for multicomponent waste glasses by the addition of Li{sub 2}O to the ``alkali`` corner of the NBS submixture.

  9. Rebound of continuous droplet streams from an immiscible liquid pool

    NASA Astrophysics Data System (ADS)

    Doak, William J.; Laiacona, Danielle M.; German, Guy K.; Chiarot, Paul R.

    2016-05-01

    We report on the rebound of high velocity continuous water droplet streams from the surface of an immiscible oil pool. The droplets have diameters and velocities of less than 90 μm and 15 m/s, respectively, and were created at frequencies up to 60 kHz. The impact and rebound of continuous droplet streams at this scale and velocity have been largely unexplored. This regime bridges the gap between single drop and jet impacts. The impinging droplets create a divot at the surface of the oil pool that had a common characteristic shape across a wide-range of droplet and oil properties. After impact, the reflected droplets maintain the same uniformity and periodicity of the incoming droplets but have significantly lower velocity and kinetic energy. This was solely attributed to the generation of a flow induced in the viscous oil pool by the impacting droplets. Unlike normally directed impact of millimeter-scale droplets with a solid surface, our results show that an air film does not appear to be maintained beneath the droplets during impact. This suggests direct contact between the droplets and the surface of the oil pool. A ballistic failure limit, correlated with the Weber number, was identified where the rebound was suppressed and the droplets were driven through the oil surface. A secondary failure mode was identified for aperiodic incoming streams. Startup effects and early time dynamics of the rebounding droplet stream were also investigated.

  10. Drop Fragmentation at Impact onto a Bath of an Immiscible Liquid

    NASA Astrophysics Data System (ADS)

    Lhuissier, H.; Sun, C.; Prosperetti, A.; Lohse, D.

    2013-06-01

    The impact of a drop onto a deep bath of an immiscible liquid is studied with emphasis on the drop fragmentation into a collection of noncoalescing daughter drops. At impact the drop flattens and spreads at the surface of the crater it transiently opens in the bath and reaches a maximum deformation, which gets larger with increasing impact velocity, before surface tension drives its recession. This recession can promote the fragmentation by two different mechanisms: At moderate impact velocity, the drop recession converges to the axis of symmetry to form a jet which then fragments by a Plateau-Rayleigh mechanism. At higher velocity the edge of the receding drop destabilizes and shapes into radial ligaments which subsequently fragment. For this latter mechanism the number N∝We3 and the size distribution of the daughter drops p(d)∝d-4 as a function of the impact Weber number We are explained on the basis of the observed spreading of the drop. The universality of this model for the fragmentation of receding liquid sheets might be relevant for other configurations.

  11. METHOD FOR MEASURING AIR-IMMISCIBLE LIQUID PARTITION COEFFICIENTS

    EPA Science Inventory

    The principal objective of this work was to measure nonaqueous phase liquid-air partition coefficients for various gas tracer compounds. Known amounts of trichloroethene (TCE) and tracer, as neat compounds, were introduced into glass vials and allowed to equilibrate. The TCE and ...

  12. Capillary foams: highly stable bubbles formed by synergistic action of particles and immiscible liquid

    NASA Astrophysics Data System (ADS)

    Meredith, Carson; Zhang, Yi; Behrens, Sven

    2015-03-01

    Liquid foams are a familiar part of everyday life from beer and frothed milk to bubble baths; they also play important roles in enhanced oil recovery, lightweight packaging, and insulation. We report a new class of foams, obtained by frothing a suspension of colloidal particles in the presence of a small amount of an immiscible secondary liquid. A unique aspect of the new foams, termed capillary foams, is that suspended particles mediate spreading of a minority liquid around gas bubbles. The resulting mixed particle/liquid coating can stabilize bubbles against coalescence even when the particles alone cannot. We demonstrate the generality of capillary foams by forming them from a diverse set of particle/liquid combinations and rationalize the results with a simple free energy model. In addition to many applications as liquid foams, capillary foams can serve as precursors for hierarchically-structured solids with porosity on different length scales and with significant application potential.

  13. Immiscible iron- and silica-rich liquids in the Upper Zone of the Bushveld Complex

    NASA Astrophysics Data System (ADS)

    Fischer, Lennart A.; Wang, Meng; Charlier, Bernard; Namur, Olivier; Roberts, R. James; Veksler, Ilya V.; Cawthorn, R. Grant; Holtz, François

    2016-06-01

    The Bushveld Complex (South Africa) is the largest layered intrusion on Earth and plays a considerable role in our understanding of magmatic differentiation and ore-forming processes. In this study, we present new geochemical data for apatite-hosted multiphase inclusions in gabbroic cumulates from the Bushveld Upper Zone. Inclusions re-homogenized at high-temperature (1060-1100 °C) display a range of compositions in each rock sample, from iron-rich (35 wt.% FeOtot; 28 wt.% SiO2) to silica-rich (5 wt.% FeOtot; 65 wt.% SiO2). This trend is best explained by an immiscible process and trapping of contrasted melts in apatite crystals during progressive cooling along the binodal of a two-liquid field. The coexistence of both Si-rich and Fe-rich immiscible melts in single apatite grains is used to discuss the ability of immiscible melts to segregate from each other, and the implications for mineral and bulk cumulate compositions. We argue that complete separation of immiscible liquids did not occur, resulting in crystallization of similar phases from both melts but in different proportions. However, partial segregation in a crystal mush and the production of contrasting phase proportions from the Fe-rich melt and the Si-rich melt can be responsible for the cyclic evolution from melanocratic (Fe-Ti-P-rich) to leucocratic (plagioclase-rich) gabbros which is commonly observed in the Upper Zone of the Bushveld Complex where it occurs at a vertical scale of 50 to 200 m.

  14. Liquid immiscibility and core-shell morphology formation in ternary Al–Bi–Sn alloys

    SciTech Connect

    Dai, R.; Zhang, J.F.; Zhang, S.G. Li, J.G.

    2013-07-15

    The effects of composition on liquid immiscibility, macroscopic morphology, microstructure and phase transformation in ternary Al–Bi–Sn alloys were investigated. Three types of morphology, the core-shell type, the stochastic droplet type and uniform dispersion type, of Al–Bi–Sn particles prepared by a jet breakup process were distinguished, and the relationships between which were discussed. The phase transformation behaviors of the Al–Bi–Sn alloys were studied by thermal analysis, in agreement with the microstructural observation and microanalysis. The liquid immiscibility and formation of the core-shell morphology in Al–Bi–Sn alloys are easily achieved when the composition lies in the liquid miscibility gap. The particles exhibit a high melting point Al-rich core with a low melting point Sn–Bi-rich solder shell, showing promise for application as high-density electronic packaging materials. - Highlights: • The liquid demixing, morphology and microstructure in Al–Bi–Sn alloys were studied. • Three types of morphology were classified and discussed. • The conditions for formation of the core-shell morphology were obtained. • The phase transition behaviors agree with the microstructure characterization. • The Al/Sn–Bi core-shell particles show promise for use in electronic packaging.

  15. Immiscible liquid-liquid pressure-driven flow in capillary tubes: Experimental results and numerical comparison

    NASA Astrophysics Data System (ADS)

    Soares, Edson J.; Thompson, Roney L.; Niero, Debora C.

    2015-08-01

    The immiscible displacement of one viscous liquid by another in a capillary tube is experimentally and numerically analyzed in the low inertia regime with negligible buoyancy effects. The dimensionless numbers that govern the problem are the capillary number Ca and the viscosity ratio of the displaced to the displacing fluids Nμ. In general, there are two output quantities of interest. One is associated to the relation between the front velocity, Ub, and the mean velocity of the displaced fluid, U ¯ 2 . The other is the layer thickness of the displaced fluid that remains attached to the wall. We compute these quantities as mass fractions in order to make them able to be compared. In this connection, the efficiency mass fraction, me, is defined as the complement of the mass fraction of the displaced fluid that leaves the tube while the displacing fluid crosses its length. The geometric mass fraction, mg, is defined as the fraction of the volume of the layer that remains attached to the wall. Because in gas-liquid displacement, these two quantities coincide, it is not uncommon in the literature to use mg as a measure of the displacement efficiency for liquid-liquid displacements. However, as is shown in the present paper, these two quantities have opposite tendencies when we increase the viscosity of the displacing fluid, making this distinction a crucial aspect of the problem. Results from a Galerkin finite element approach are also presented in order to make a comparison. Experimental and numerical results show that while the displacement efficiency decreases, the geometrical fraction increases when the viscosity ratio decreases. This fact leads to different decisions depending on the quantity to be optimized. The quantitative agreement between the numerical and experimental results was not completely achieved, especially for intermediate values of Ca. The reasons for that are still under investigation. The experiments conducted were able to achieve a wide range

  16. Compositions of magmas and carbonate silicate liquid immiscibility in the Vulture alkaline igneous complex, Italy

    NASA Astrophysics Data System (ADS)

    Solovova, I. P.; Girnis, A. V.; Kogarko, L. N.; Kononkova, N. N.; Stoppa, F.; Rosatelli, G.

    2005-11-01

    This paper presents a study of melt and fluid inclusions in minerals of an olivine-leucite phonolitic nephelinite bomb from the Monticchio Lake Formation, Vulture. The rock contains 50 vol.% clinopyroxene, 12% leucite, 10% alkali feldspars, 8% hauyne/sodalite, 7.5% nepheline, 4.5% apatite, 3.2% olivine, 2% opaques, 2.6% plagioclase, and < 1% amphibole. We distinguished three generations of clinopyroxene differing in composition and morphology. All the phenocrysts bear primary and secondary melt and fluid inclusions, which recorded successive stages of melt evolution. The most primitive melts were found in the most magnesian olivine and the earliest clinopyroxene phenocrysts. The melts are near primary mantle liquids and are rich in Ca, Mg and incompatible and volatile elements. Thermometric experiments with the melt inclusions suggested that melt crystallization began at temperatures of about 1200 °C. Because of the partial leakage of all primary fluid inclusions, the pressure of crystallization is constrained only to minimum of 3.5 kbar. Combined silicate-carbonate melt inclusions were found in apatite phenocrysts. They are indicative of carbonate-silicate liquid immiscibility, which occurred during magma evolution. Large hydrous secondary melt inclusions were found in olivine and clinopyroxene. The inclusions in the phenocrysts recorded an open-system magma evolution during its rise towards the surface including crystallization, degassing, oxidation, and liquid immiscibility processes.

  17. A planar lens based on the electrowetting of two immiscible liquids

    NASA Astrophysics Data System (ADS)

    Liu, Chao-Xuan; Park, Jihwan; Choi, Jin-Woo

    2008-03-01

    This paper reports the development and characterization of a planar liquid lens based on electrowetting. The working concept of electrowetting two immiscible liquids is demonstrated with measurement and characterization of contact angles with regard to externally applied electric voltages. Consequently, a planar liquid lens is designed and implemented based on this competitive electrowetting. A droplet of silicone oil confined in an aqueous solution (1% KCl) works as a liquid lens. Electrowetting then controls the shape of the confined silicone oil and the focal length of the liquid lens varies depending upon an applied dc voltage. A unique feature of this lens design is the double-ring planar electrodes beneath the hydrophobic substrate. While an outer ring electrode provides an initial boundary for the silicone oil droplet, an inner ring works as the actuation electrode for the lens. Further, the planar electrodes, instead of vertical or out-of-plane wall electrodes, facilitate the integration of liquid lenses into microfluidic systems. With the voltage applied in the range of 50-250 V, the confined silicone oil droplet changed its shape and the optical magnification of a 3 mm-diameter liquid lens was clearly demonstrated. Moreover, focal lengths of liquid lenses with diameters of 2 mm, 3 mm and 4 mm were characterized, respectively. The obtained results suggest that a larger lens diameter yields a longer focal length and a wider range of focal length change in response to voltage. The demonstrated liquid lens has a simple structure and is easy to fabricate.

  18. Heat transfer between stratified immiscible liquid layers driven by gas bubbling across the interface

    SciTech Connect

    Greene, G.A.; Irvine, T.F. Jr.

    1988-01-01

    The modeling of molten core debris in the CORCON and VANESA computer codes as overlying, immiscible liquid layers is discussed as it relates to the transfer of heat and mass between the layers. This initial structure is identified and possible configurations are discussed. The stratified, gas-sparged configuration that is presently employed in CORCON and VANESA is examined and the existing literature for interlayer heat transfer is assessed. An experiment which was designed to measure interlayer heat transfer with gas sparging is described. The results are presented and compared to previously existing models. A dimensionless correlation for stratified, interlayer heat transfer with gas sparging is developed. This relationship is recommended for inclusion in CORCON-MOD2 for heat transfer between stratified, molten liquid layers. 12 refs., 6 figs., 3 tabs.

  19. Natural damped frequencies of an infinitely long column of immiscible viscous liquids

    NASA Astrophysics Data System (ADS)

    Bauer, H. F.

    Extended space flights and manned earth-orbiting space laboratories provide for manufacturing processes and experiments conditions which are not found on the surface of the earth. The availability of conditions involving highly reduced or zero gravity are of interest for many engineering disciplines, taking into account fluid mechanics, materials sciences, and crystal growth. Thus, floating zone melting under zero gravity conditions has great advantages. However, there are also certain difficulties. The floating zone has, for instance, a free liquid surface which is susceptible to dynamic disturbances. The stability problems which arise have been studied by a number of authors. The present investigation is concerned with infinitely long systems which consist of immiscible liquids of different densities and viscosities. Approaches for determining the natural damped frequencies and the decay of the motion of surface waves are discussed.

  20. Analysis of convection in immiscible liquid layers with novel particle tracking velocimetry

    NASA Technical Reports Server (NTRS)

    Koster, J. N.; Prakash, A.; Campbell, T. A.; Pline, A.

    1992-01-01

    The problem under study is convective flow in immiscible liquid layers with one or two horizontal interfaces. In one-g the flow results primarily from the buoyancy force acting perpendicular to the interfaces. This creates a fluid mechanical system in which the coupling of the fluid layers across an interface plays a fundamental role. The contribution of two horizontal interface tension forces is marginal. Interface tension driven flow requires testing in microgravity. A flight experiment on the Bubble, Drop, and Particle Unit (BDPU) is planned for the second International Microgravity Laboratory (IML-2) mission onboard the Shuttle in 1994. The flow velocity fields will be analyzed by a whole-field Particle Displacement Tracking (PDT) velocimetry technique. The capabilities of this technique to address fundamental issues, such as those regarding the flow stucture, will be discussed with a few sample experiments. Experimental and numerical flow patterns are compared.

  1. Silica Transport and Distribution in Saline, Immiscible Fluids: Application to Subseafloor Hydrothermal Systems

    NASA Astrophysics Data System (ADS)

    Steele-Macinnis, M.; Bodnar, R. J.; Lowell, R.; Rimstidt, J. D.

    2009-05-01

    Quartz is a nearly ubiquitous gangue mineral in hydrothermal mineral deposits, most often constituting the bulk of hydrothermal mineralization. The dissolution, transport and precipitation of quartz is controlled by the solubility of silica; in particular, in hot hydrothermal fluids in contact with quartz, silica saturation can generally be assumed, as rates of dissolution and precipitation are generally much faster than fluid flow rates. The solubility of silica in aqueous fluids can be used to understand the evolution of hydrothermal systems by tracing the silica distribution in these systems through time. The solubility of quartz in an aqueous fluid is dependent upon the pressure, temperature and composition (PTX) of the fluid. Silica solubility in pure water as a function of pressure and temperature is well understood. However, natural fluids contain variable amounts of dissolved ionic species, thus it is necessary to include the effects of salinity on silica solubility to accurately predict quartz distribution in hydrothermal systems. In particular, addition of NaCl results in enhanced quartz solubility over a wide range of PT conditions. Furthermore, if phase separation occurs in saline fluids, silica is preferentially partitioned into the higher salinity brine phase; if vapor is removed from the system, the bulk salinity in the system evolves towards the brine end member, and overall silica solubility is enhanced. There is abundant evidence from natural fluid inclusions for fluid immiscibility in hydrothermal ore deposits. Additionally, recent hydrothermal models that include fluid phase equilibria effects predict that phase separation may be an important control on the distribution of dissolved components in seafloor hydrothermal systems. An empirical equation describing the solubility of silica in salt-bearing hydrothermal solutions over a wide range of PTX conditions has been incorporated into a multiphase fluid flow model for seafloor hydrothermal

  2. TWOLIQ.FOR: a FORTRAN77 program for simulating immiscibility in silicate liquids

    NASA Astrophysics Data System (ADS)

    Ma, H.; Hu, Y.; Fang, T.

    1999-03-01

    The program TWOLIQ.FOR is designed for predicting immiscibility in silicate liquids, by the thermodynamic criterion: ∑( Ai/ T+ CiP/ T) XiHo≥-∑(∑ DiXiHo- Bi) XiHo and for calculating compositions and amounts of the conjugate liquids from oxide partition coefficients between the coexisting Si- and Fe-rich melts, expressed as: ln( XiSi/ XiFe)= ai/ T+ bi+ ciP/ T+∑ diXiHo. Where T and P denote temperature (in Kelvin) and pressure (in GPa), respectively, X i mole fraction of oxide i, Ho, Si and Fe refer to homogeneous, Si- and Fe-rich melt phases, respectively and A i to D i, a i to d i are constants. Uncertainties of calculated oxide compositions in the liquids are 3.0-4.0 mol% for SiO 2, Al 2O 3 and FeO, less than 1.0 mol% for the other oxides and predicted amounts around 1.0 mol% for the coexisting two liquids. Ore-forming processes of magnetite-apatite deposits, therefore, can be numerically simulated by the program.

  3. Optofluidic restricted imaging, spectroscopy and counting of nanoparticles by evanescent wave using immiscible liquids.

    PubMed

    Liang, L; Zuo, Y F; Wu, W; Zhu, X Q; Yang, Y

    2016-08-21

    Conventional flow cytometry (FC) suffers from the diffraction limit for the detection of nanoparticles smaller than 100 nm, whereas traditional total internal reflection (TIR) microscopy can only detect few samples near the solid-liquid interface mostly in static states. Here we demonstrate a novel on-chip optofluidic technique using evanescent wave sensing for single nanoparticle real time detection by combining hydrodynamic focusing and TIR using immiscible flows. The immiscibility of the high-index sheath flow and the low-index core flow naturally generate a smooth, flat and step-index interface that is ideal for the TIR effect, whose evanescent field can penetrate the full width of the core flow. Hydrodynamic focusing can focus on all the nanoparticles in the extreme centre of the core flow with a width smaller than 1 μm. This technique enables us to illuminate every single sample in the running core flow by the evanescent field, leaving none unaffected. Moreover, it works well for samples much smaller than the diffraction limit. We have successfully demonstrated the scattering imaging and counting of 50 nm and 100 nm Au nanoparticles and also the fluorescence imaging and counting of 200 nm beads. The effective counting speeds are estimated as 1500, 2300 and 2000 particles per second for the three types of nanoparticles, respectively. The optical scattering spectra were also measured to determine the size of individual Au nanoparticles. This provides a new technique to detect nanoparticles and we foresee its application in the detection of molecules for biomedical analyses. PMID:26984126

  4. Dynamics of Pinch-Off in Immiscible Liquid/Liquid Jets

    NASA Astrophysics Data System (ADS)

    Longmire, E. K.; Webster, D. R.; Lowengrub, J. S.

    1997-11-01

    The behavior of glycerine/water jets flowing into a nearly immiscible ambient of Dow Corning 200 fluid is investigated using laser induced fluorescence flow visualization and particle image velocimetry. Clear images are obtained by matching the index of refraction in the glycerine/water solution with the index of refraction in the surrounding Dow Corning fluid. Jet Reynolds numbers are on the order of 100. The pinch-off of the jet column into droplets can be made repeatable by periodic forcing, and several pinch-off modes are examined. These modes are produced by varying the forcing frequency and amplitude, fluid viscosity ratio, and jet Reynolds number. The details of the pinch-off, including local variations in concentration near the transition location and the associated velocity fields will be discussed. The experimental results will be compared with numerical simulations that allow limited chemical mixing across the finite-thickness interface.

  5. Silicate-natrocarbonatite liquid immiscibility in 1917 eruption combeite-wollastonite nephelinite, Oldoinyo Lengai Volcano, Tanzania: Melt inclusion study

    NASA Astrophysics Data System (ADS)

    Sharygin, Victor V.; Kamenetsky, Vadim S.; Zaitsev, Anatoly N.; Kamenetsky, Maya B.

    2012-11-01

    Primary silicate-melt and carbonate-salt inclusions occur in the phenocrysts (nepheline, fluorapatite, wollastonite, clinopyroxene) in the 1917 eruption combeite-wollastonite nephelinite at Oldoinyo Lengai. Silicate-melt inclusions in nepheline clearly show liquid immiscibility phenomena expressed in the presence of carbonate globules in silicate glass. The coexistence of inclusions with markedly different proportions of silicate glass + vapor-carbonate globule in the core of nepheline phenocrysts, the presence of carbonate-salt inclusions in fluorapatite and our heating experiments strongly suggest that their entrapment began at temperatures higher than 1130 °C in an intermediate chamber when initial carbonated nephelinite melt was heterogeneous and represented a mixture of immiscible liquids. Silicate-natrocarbonatite melt immiscibility took place at high temperature and immiscible nephelinite and carbonatite liquids coexisted over a wide temperature range from ≥ 1130 °C to 600 °C. Homogenization of a carbonate globule (dissolution of the gas bubble in carbonate melt) at 900-940 °C indicates that after separation from silicate magma the natrocarbonatite represented homogeneous liquid in the 900-1130 °C temperature range, whereas below these temperatures immiscible melts of different composition and fluid phase have separated from it. The bulk composition of homogeneous natrocarbonatite melt may be estimated as ≈ 20% CaF2, 40-60% (Na,K)2CO3 and 20-40% CaCO3 based on the coexistence of nyerereite, calcite and fluorite and the rapid phase transition (carbonate aggregate → carbonate liquid) at 550-570 °C observed in vapor-carbonate globules of nepheline-hosted silicate-melt inclusions and on the Na2CO3-CaCO3-CaF2 phase diagram. Silicate glasses of nepheline-hosted immiscible inclusions drastically differ from host nephelinite in the abundance of major and trace elements. They are high peralkaline ((Na + K)/Al — up to 9.5) and virtually free of water (H2

  6. SPAR 5 experiment no. 74-30 agglomeration in immiscible liquids

    NASA Technical Reports Server (NTRS)

    Gelles, S.; Markworth, A. J.

    1979-01-01

    The influence of gravity, cooling rate, and composition on the macro-and microstructure of liquid phase immiscible alloys were researched. Aluminum indium alloys of compositions 30, 40, 70, and 90 weight percent indium were processed aboard two sounding rocket flights, SPAR 2 and SPAR 5. Radiographic and metallographic examination of the SPAR 2 flight and ground base samples showed the expected separation at lg of the ground base alloys into indium rich and aluminum rich layers. The flight alloys produced an aluminum rich core surrounding by indium rich metal. The results obtained from the SPAR 5 40 and 70 weight percent indium alloys were essentially identical to those from SPAR 2. The 30 and 90 weight percent indium alloys also showed massive separation into configuration similar to the 40 and 70 weight percent indium alloys. The 90 weight percent indium alloy showed additional evidence that surface tension induced droplet migration had occurred in this alloy which could at least in part account for the observed structures.

  7. Sol-Gel synthesis of MgO-SiO2 glass compositions having stable liquid-liquid immiscibility

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam P.

    1987-01-01

    MgO-SiO2 glasses containing up to 15 mol % MgO, which could not have been prepared by the conventional glass melting method due to the presence of stable liquid-liquid immiscibility, were synthesized by the sol-gel technique. Clear and transparent gels were obtained from the hydrolysis and polycondensation of silicon tetraethoxide (TEOS) and magnesium nitrate hexahydrate when the water/TEOS mole ratio was four or more. The gelling time decreased with increase in magnesium content, water/TEOS ratio, and reaction temperature. Magnesium nitrate hexahydrate crystallized out of the gels containing 15 and 20 mol % MgO on slow drying. This problem was partially alleviated by drying the gels quickly at higher temperatures. Monolithic gel samples were prepared using glycerol as the drying control additive. The gels were subjected to various thermal treatments and characterized by several methods. No organic groups could be detected in the glasses after heat treatments to approx. 800 C, but trace amounts of hydroxyl groups were still present. No crystalline phase was found from X-ray diffraction in the gel samples to approx. 890 C. At higher temperatures, alpha quartz precipitated out as the crystalline phase in gels containing up to 10 mol % MgO. The overall activation energy for gel formation in 10MgO-90SiO2 (mol %) system for water/TEOS mole ratio of 7.5 was calculated to be 58.7 kJ/mol.

  8. Low temperature synthesis of CaO-SiO2 glasses having stable liquid-liquid immiscibility by sol-gel process

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam P.

    1990-01-01

    Calcium silicate glass compositions lying within the liquid-liquid immiscibility dome of the phase diagram, which could not have been prepared by the conventional melting method, were synthesized by the sol-gel process. Hydrolysis and polycondensation of tetraethyl orthosilicate (TEOS) solutions containing up to 20 mol percent calcium nitrate resulted in the formation of clear and transparent gels. The gel formation time decreased with increase in water:TEOS mole ratio, calcium content, and the reaction temperature. Smaller values of gel times in the presence of calcium nitrate are probably caused by lowering of the ionic charge on the sol particles by the salt present. The gelation activation energy, E(sub gel), was evaluated from temperature dependence of the gel time. Presence of Ca(2+) ions or the water:TEOS mole ratio did not have an appreciable effect on the value of E(sub gel). Presence of glycerol in the solution helped in the formation of crack-free monolithic gel specimens. Chemical and structural changes occurring in the gels, as a function of the heat treatments, have been monitored using DTA, TGA, IR-spectroscopy, x ray diffraction, surface area and pore size distribution measurements.

  9. Low temperature synthesis of CaO-SiO2 glasses having stable liquid-liquid immiscibility by the sol-gel process

    NASA Technical Reports Server (NTRS)

    Bansal, N. P.

    1992-01-01

    Calcium silicate glass compositions lying within the liquid-liquid immiscibility dome of the phase diagram, which could not have been prepared by the conventional melting method, were synthesized by the sol-gel process. Hydrolysis and polycondensation of tetraethyl orthosilicate (TEOS) solutions containing up to 20 mol percent calcium nitrate resulted in the formation of clear and transparent gels. The gel formation time decreased with increase in water: TEOS mole ratio, calcium content, and the reaction temperature. Smaller values of gel times in the presence of calcium nitrate are probably caused by lowering of the ionic charge on the sol particles by the salt present. The gelation activation energy, E(sub gel), was evaluated from temperature dependence of the gel time. Presence of Ca(2+) ions or the water:TEOS mole ratio did not have an appreciable effect on the value of E(sub gel). Presence of glycerol in the solution helped in the formation of crack-free monolithic gel specimens. Chemical and structural changes occurring in the gels, as a function of the heat treatments, have been monitored using DTA, TGA, IR-spectroscopy, X-ray diffraction, surface area and pore size distribution measurements.

  10. In situ synchrotron study of liquid phase separation process in Al-10 wt.% Bi immiscible alloys by radiography and small angle X-ray scattering

    NASA Astrophysics Data System (ADS)

    Lu, W. Q.; Zhang, S. G.; Li, J. G.

    2016-03-01

    Liquid phase separation process of immiscible alloys has been repeatedly tuned to create special structure for developing materials with unique properties. However, the fundamental understanding of the liquid phase separation process is still under debate due to the characteristics of immiscible alloys in opacity and high temperature environment of alloy melt. Here, the liquid phase separation process in solidifying Al-Bi immiscible alloys was investigated by synchrotron radiography and small angle X-ray scattering. We provide the first direct evidence of surface segregation prior to liquid decomposition and present that the time dependence on the number of Bi droplets follows Logistic curve. The liquid decomposition results from a nucleation and growth process rather than spinodal decomposition mechanism because of the positive deviation from Porod's law. We also found that the nanometer-sized Bi-rich droplets in Al matrix melt present mass fractal characteristics.

  11. Field and modelling studies of immiscible fluid flow above a contaminated water-table aquifer

    USGS Publications Warehouse

    Herkelrath, W.N.; Essaid, H.I.; Hess, K.M.

    1991-01-01

    A method was developed for measuring the spatial distribution of immiscible liquid contaminants in the subsurface. Fluid saturation distributions measured at a crude-oil spill site were used to test a numerical multiphase flow model.

  12. A General Strategy for the Separation of Immiscible Organic Liquids by Manipulating the Surface Tensions of Nanofibrous Membranes.

    PubMed

    Wang, Li; Zhao, Yong; Tian, Ye; Jiang, Lei

    2015-12-01

    Oil/water separation membranes with different wettability towards water are attractive for their economic efficiency and convenience. The key factor for the separation process is the roughness-enhanced wettability of membranes based on the intrinsic wetting threshold (IWT) of water, that is, the limitation of the wettability caused by hydrophobicity and hydrophilicity. However, the separation of organic liquids (OLs) remains a challenge. Herein, we manipulate the surface tensions of nanofibrous membranes to lie between the IWTs of the two OLs to be separated so that the nanofibrous membranes can be endowed with superlyophobicity and superlyophilicity for the two liquids, and thus lead to successful separation. Our investigations provide a general strategy to separate any immiscible liquids efficiently, and may lead to the development of membranes with a large capacity, high flux, and high selectivity for organic reactions or liquid extraction in chemical engineering. PMID:26492856

  13. The Study of a Liquid Droplet Falling Through Two Immiscible Layers of Liquids

    NASA Astrophysics Data System (ADS)

    Mesa, Bianca

    2013-11-01

    In an exploratory experiment, we noticed the unusual behaviors of liquid droplets falling through layers of oil and water. A rectangular container was filled with an aqueous solution and a layer of oil. A dropper was used to control the size of the droplet. Water was mixed with Bromothymol Blue dye, a chemical indicator, to visualize the flow processes. Surface tension and the buoyancy of the oil layer between the liquid droplet and the water below caused the liquid droplet to be stopped at the interface. Over time, the support weakened and the droplet would fall quickly through the water. The first of two cases was a salt water solution with NaOH, and the second consisted of balsamic vinegar and NaOH. Once the salt water droplet touched the aqueous solution, it collapsed, sank and spread rapidly at the interface. The sinking motion dragged the spreading fluid back to its center and then down. For the second case, a trace amount of the droplet spread rapidly at the interface while the main portion of the droplet sank and then spontaneously exploded. The difference in behavior is mainly due to the surface tension of the droplet in water. The underlying mechanisms of the droplet's flow instability are from the effects of diffusion weakening the surface tension. Bianca Mesa is an undergraduate student in the Ocean and Mechanical Engineering Department at Florida Atlantic University. She is pursuing a B.S. degree in Ocean Engineering. In addition to her academic interests, she is also an avid sailor.

  14. Rare earth element selenochemistry of immiscible liquids and zircon at Apollo 14 - An ion probe study of evolved rocks on the moon

    NASA Technical Reports Server (NTRS)

    Snyder, Gregory A.; Taylor, Lawrence A.; Crozaz, Ghislaine

    1993-01-01

    Results are presented of trace-element analyses of three lunar zircons. The major-element and REE compositions were determined using electron microprobes, and a correction was made for zircon for Zr-Si-O molecular interferences in the La to Pr mass region. The three zircons were found to exhibit similar REE abundances and patterns. Results of the analyses confirm earlier studies (Hess et al., 1975; Watson, 1976; Neal and Taylor, 1989) on the partitioning behavior of trace elements in immiscible liquid-liquid pairs. The results also support the postulated importance of silicate liquid immiscibility in the differentiation of the upper mantle and crust of the moon.

  15. The formation of metal/metal-matrix nano-composites by the ultrasonic dispersion of immiscible liquid metals

    SciTech Connect

    Keppens, V.M.; Mandrus, D.; Boatner, L.A.; Rankin, J.

    1996-12-01

    Ultrasonic energy has been used to disperse one liquid metallic component in a second immiscible liquid metal, thereby producing a metallic emulsion. Upon lowering the temperature of this emulsion below the mp of the lowest-melting constituent, a metal/metal-matrix composite is formed. This composite consists of sub-micron-to-micron- sized particles of the minor metallic phase that are embedded in a matrix consisting of the major metallic phase. Zinc-bismuth was used as a model system, and ultrasonic dispersion of a minor Bi liquid phase was used to synthesize metal/metal-matrix composites. These materials were characterized using SEM and energy-dispersive x-ray analysis.

  16. Apparatus and method for pumping hot, erosive slurry of coal solids in coal derived, water immiscible liquid

    DOEpatents

    Ackerman, Carl D.

    1983-03-29

    An apparatus for and method of pumping hot, erosive slurry of coal solids in a coal derived, water immiscible liquid to higher pressure involves the use of a motive fluid which is miscible with the liquid of the slurry. The apparatus includes a pump 12, a remote check valve 14 and a chamber 16 between and in fluid communication with the pump 12 and check valve 14 through conduits 18,20. Pump 12 exerts pressure on the motive fluid and thereby on the slurry through a concentration gradient of coal solids within chamber 16 to alternately discharge slurry under pressure from the outlet port of check valve 14 and draw slurry in through the inlet port of check valve 14.

  17. FIELD TEST OF CYCLODEXTRIN FOR ENHANCED IN-SITU FLUSHING OF MULTIPLE-COMPONENT IMMISCIBLE ORGANIC LIQUID CONTAMINATION: PROJECT OVERVIEW AND INITIAL RESULTS

    EPA Science Inventory

    The purpose of this paper is to present an overview and the initial results of a pilot-scale experiment designated to test the use of cyclodextrin for enhanced in-situ flushing of an aquifer contaminated by immiscible liquid. This is the first field test of this technology, terme...

  18. Dissolution of a multicomponent droplet in an immiscible ambient fluid: Application of the distribution law

    NASA Astrophysics Data System (ADS)

    Chu, Shigan; Prosperetti, Andrea; Andrea Prosperetti Collaboration

    2015-11-01

    A liquid droplet will shrink in an undersaturated ambient liquid medium due to mass transfer across the interface even when the drop liquid is only sparingly soluble in the host liquid. The dissolution rate of a single-component droplet can be accurately predicted by an adaptation of the the Epstein-Plesset theory, in which it is assumed that the droplet surface remains at saturation. This hypothesis may be violated in the case of a multi-component droplet, as the more soluble component dissolves faster than the other(s). As a consequence, the droplet surface cannot remain saturated with this component in the later stages of the process. To account for this feature a modified Epstein-Plesset theory is developed on the basis of the distribution law of liquid-liquid solutions. The implications of the teory are illustrated with several examples. This study was supported by a grant from BP/The Gulf of Mexico Research Initiative through the University of Texas Marine Science Institute (DROPPS consortium: ``Dispersion Research on Oil: Physics and Plankton Studies''). The funders had no role in study.

  19. Surrogate immiscible liquid pairs with refractive indexes matchable over a wide range of density and viscosity ratios

    NASA Astrophysics Data System (ADS)

    Saksena, Rajat; Christensen, Kenneth T.; Pearlstein, Arne J.

    2015-08-01

    In liquid-liquid flows, use of optical diagnostics is limited by interphase refractive index mismatch, which leads to optical distortion and complicates data interpretation, and sometimes also by opacity. Both problems can be eliminated using a surrogate pair of immiscible index-matched transparent liquids, whose density and viscosity ratios match corresponding ratios for the original liquid pair. We show that a wide range of density and viscosity ratios is accessible using aqueous solutions of 1,2-propanediol and CsBr (for which index, density, and viscosity are available), and solutions of light and heavy silicone oils and 1-bromooctane (for which we measured the same properties at 119 compositions). For each liquid phase, polynomials in the composition variables, least-squares fitted to index and density and to the logarithm of kinematic viscosity, were used to determine accessible density and viscosity ratios for each matchable index. Index-matched solution pairs can be prepared with density and viscosity ratios equal to those for water-liquid CO2 at 0 °C over a range of pressure (allowing water-liquid CO2 behavior at inconveniently high pressure to be simulated by 1-bar experiments), and for water-crude oil and water-trichloroethylene (avoiding opacity and toxicity problems, respectively), each over a range of temperature. For representative index-matched solutions, equilibration changes index, density, and viscosity only slightly, and mass spectrometry and elemental analysis show that no component of either phase has significant interphase solubility. Finally, procedures are described for iteratively reducing the residual index mismatch in surrogate solution pairs prepared on the basis of approximate polynomial fits to experimental data, and for systematically dealing with nonzero interphase solubility.

  20. The role of liquid-liquid immiscibility and crystal fractionation in the genesis of carbonatite magmas: insights from Kerimasi melt inclusions

    NASA Astrophysics Data System (ADS)

    Guzmics, Tibor; Zajacz, Zoltán; Mitchell, Roger H.; Szabó, Csaba; Wälle, Markus

    2015-02-01

    We have reconstructed the compositional evolution of the silicate and carbonate melt, and various crystalline phases in the subvolcanic reservoir of Kerimasi Volcano in the East African Rift. Trace element concentrations of silicate and carbonate melt inclusions trapped in nepheline, apatite and magnetite from plutonic afrikandite (clinopyroxene-nepheline-perovskite-magnetite-melilite rock) and calciocarbonatite (calcite-apatite-magnetite-perovskite-monticellite-phlogopite rock) show that liquid immiscibility occurred during the generation of carbonatite magmas from a CO2-rich melilite-nephelinite magma formed at relatively high temperatures (1,100 °C). This carbonatite magma is notably more calcic and less alkaline than that occurring at Oldoinyo Lengai. The CaO-rich (32-41 wt%) nature and alkali-"poor" (at least 7-10 wt% Na2O + K2O) nature of these high-temperature (>1,000 °C) carbonate melts result from strong partitioning of Ca (relative to Mg, Fe and Mn) in the immiscible carbonate and the CaO-rich nature (12-17 wt%) of its silicate parent (e.g., melilite-nephelinite). Evolution of the Kerimasi carbonate magma can result in the formation of natrocarbonatite melts with similar composition to those of Oldoinyo Lengai, but with pronounced depletion in REE and HFSE elements. We suggest that this compositional difference results from the different initial parental magmas, e.g., melilite-nephelinite at Kerimasi and a nephelinite at Oldoinyo Lengai. The difference in parental magma composition led to a significant difference in the fractionating mineral phase assemblage and the element partitioning systematics upon silicate-carbonate melt immiscibility. LA-ICP-MS analysis of coeval silicate and carbonate melt inclusions provides an opportunity to infer carbonate melt/silicate melt partition coefficients for a wide range of elements. These data show that Li, Na, Pb, Ca, Sr, Ba, B, all REE (except Sc), U, V, Nb, Ta, P, Mo, W and S are partitioned into the carbonate

  1. Large-scale liquid immiscibility and fractional crystallization in the 1780 Ma Taihang dyke swarm: Implications for genesis of the bimodal Xiong'er volcanic province

    NASA Astrophysics Data System (ADS)

    Peng, Peng; Wang, Xinping; Lai, Yong; Wang, Chong; Windley, Brian F.

    2015-11-01

    Immiscibility is a potential mechanism for the formation of high-Fe-Ti-P rocks; however, whether large-scale segregation and eruption of high-Si lavas can occur in nature has yet to be proven. In this study, we investigate the possibility of immiscibility between the cogenetic 1780 Ma high-Fe-Ti-P-bearing Taihang dykes and the 'bimodal' Xiong'er volcanics in North China. The compositions of silicate melt inclusions in plagioclase megacrysts of the dykes provide a new approach to obtain the primary liquid. Mineral and bulk-rock compositions reveal that large compositional variations in the dykes are the result of plagioclase- and clinopyroxene-dominated fractional crystallization and of density-driven mineral sorting, which together caused the liquids to be poor in Ca-Al but rich in Fe-Ti-P-K, and thus chemically immiscible. Conjugate interstitial granophyric and ilmenite-rich intergrowths and reactive microstructures especially olivine coronas in the dykes, and Si-/Fe-Ti-rich globules in the volcanics, provide petrographic evidence for the presence of two coeval, coexisting liquids in equilibrium separated by a miscibility gap, and thus for immiscibility and segregation/migration. The fractional crystallization and subsequent segregation were responsible for the compositional diversity of the Taihang dykes and also of the 'bimodal' Xiong'er volcanics. Accordingly, the dacite and rhyolite lavas are potentially the high-Si counterparts of the high-Ti dykes, and the basalt and andesite lavas are the erupted equivalents of the relatively low-Ti dykes. It is likely that the sustained plagioclase- and clinopyroxene-dominated fractional crystallization, and the enhanced fO2 were responsible for the immiscibility. The segregation probably took place during the ascent of the liquid in the pumping system (feeder dykes). This likely represents one natural example of crust-scale immiscibility from which many high-Ti dykes and silicic lavas (~ 1/3 volume of the Xiong

  2. ASSESSMENT OF THE ABILITY OF STANDARD SLURRY PUMPS TO MIX MISCIBLE AND IMMISCIBLE LIQUIDS IN TANK 50H

    SciTech Connect

    Poirier, M.

    2011-06-15

    Tank 50H is the feed tank for the Saltstone Production Facility (SPF). At present, Tank 50H contains two standard slurry pumps and two Quad Volute slurry pumps. Current requirements and mixing operation is to run three pumps for one hour prior to initiating a feed transfer to SPF. Savannah River Site (SRS) Liquid Waste would like to move one or both of the Quad Volute pumps from Tank 50H to Tank 51H to replace pumps in Tank 51H that are failing. In addition, one of the standard pumps in Tank 50H exhibits high seal leakage and vibration. SRS Liquid Waste requested Savannah River National (SRNL) to conduct a study to evaluate the feasibility of mixing the contents of Tank 50H with one to three standard slurry pumps. To determine the pump requirements to blend miscible and immiscible liquids in Tank 50H, the author reviewed the pilot-scale blending work performed for the Salt Disposition Integration Project (SDIP) and the technical literature, and applied the results to Tank 50H to determine the number, size, and operating parameters needed to blend the tank contents. The conclusions from this analysis are: (1) A single rotating standard slurry pump (with a 13.6 ft{sup 2}/s U{sub 0}D) will be able to blend miscible liquids (i.e., salt solution) in Tank 50H within 4.4 hours. (2) Two rotating standard slurry pumps will be able to blend miscible liquids in Tank 50H within 3.1 hours. (3) Three rotating standard slurry pumps will be able to blend miscible liquids in Tank 50H within 2.5 hours. (4) A single rotating standard slurry pump (with a 13.6 ft{sup 2}/s U{sub 0}D) will disperse Isopar L{reg_sign} droplets that are less than or equal to 15 micron in diameter. If the droplets are less than 15 micron, they will be dispersed within 4.4 hours. Isopar L{reg_sign} provides a lower bound on the maximum size of droplets that will be dispersed by the slurry pumps in Tank 50H. (5) Two rotating standard slurry pumps will disperse Isopar L{reg_sign} droplets less than 15 micron

  3. Silicate liquid immiscibility in magmas and in the system K2O-FeO-AI2O3-SiO2: an example of serendipity

    USGS Publications Warehouse

    Roedder, E.

    1978-01-01

    The concept of silicate liquid immiscibility was invoked early in the history of petrology to explain certain pairs of compositionally divergent rocks, but. as a result of papers by Greig (Am. J. Sci. 13, 1-44, 133-154) and Bowen (The Evolution of the Igneous Rocks), it fell into disfavor for many years. The discovery of immiscibility in geologically reasonable temperature ranges and compositions in experimental work on the system K2O-FeO-Al2O3-SiO2, and of evidence for immiscibility in a variety of lunar and terrestrial rocks, has reinstated the process. Phase equilibria in the high-silica corner of the tetrahedron representing the system K2O- FeO-Al2O3-SiO2 are presented, in the form of constant FeO sections through the tetrahedron, at 10% increments. Those sections, showing the tentative relationships of the primary phase volumes, are based on 5631 quenching runs on 519 compositions, made in metallic iron containers in pure nitrogen. Thirteen crystalline compounds are involved, of which at least six show two or more crystal modifica-tions. Two separate phase volumes, in each of which two immiscible liquids, one iron-rich and the other iron-poor, are present at the liquidus. One of these volumes is entirely within the quaternary system, astride the 1:1 K2O:Al2O3 plane. No quaternary compounds as such have been found, but evidence does point toward at least partial quaternary solid solution, with rapidly lowering liquidus temperatures, from K2O??Al2O3?? 2SiO2 ('potash nepheline', kalsilite. kaliophilite) to the isostructural compound K2O??FeO??3SiO2, and from K2O??Al2O3??4SiO2 (leucite) to the isostructural compound K2O??FeO??5SiO2, Both of these series apparently involve substitution, in tetrahedral coordination. of a ferrous iron and a silicon ion for two aluminum ions. Some of the 'impurities' found in analyses of the natural phases may reflect these substitutions. As a result of the geometry of the immiscibility volume located entirely within the quaternary

  4. The liquid immiscibility and associated monotectic reaction in Zn-ln system

    NASA Astrophysics Data System (ADS)

    Dhua, S. K.; Raju, S.; Chattopadhyay, K.

    1991-01-01

    The Zn-In system is shown to have a submerged miscibility gap in the liquid state. This and the resulting monotectic reaction can be accessed by purifying the alloy with a zinc chloride slag. The metallography of slowly cooled ZnCl2 slag enclosed alloys reveals a variety of monotectic microstructures including those characteristic of cooperative growth. The monotectic second liquid is often plate-shaped. The special role of the anisotropy of surface energy of zinc in the evolution of such microstructural features is elucidated.

  5. The liquid immiscibility and associated monotectic reaction in Zn-ln system

    NASA Astrophysics Data System (ADS)

    Dhua, S. K.; Raju, S.; Chattopadhyay, K.

    1987-01-01

    The Zn-In system is shown to have a submerged miscibility gap in the liquid state. This and the resulting monotectic reaction can be accessed by purifying the alloy with a zinc chloride slag. The metallography of slowly cooled ZnCl2 slag enclosed alloys reveals a variety of monotectic microstructures including those characteristic of cooperative growth. The monotectic second liquid is often plate-shaped. The special role of the anisotropy of surface energy of zinc in the evolution of such microstructural features is elucidated.

  6. Lightning strike fusion: extreme reduction and metal-silicate liquid immiscibility.

    PubMed

    Essene, E J; Fisher, D C

    1986-10-10

    A glassy fulgurite, formed recently on a morainal ridge in southeastern Michigan, contains micrometer- to centimeter-sized metallic globules rich in native silicon, which unmixed from a silica-rich liquid. The unusual character of these globules and their potential for elucidating conditions of fulgurite formation prompted further study. Thermodynamic calculations indicate that temperatures in excess of 2000 K and reducing conditions approaching those of the SiO(2)-Si buffer were needed to form the coexisting metallic and silicate liquids. The phases produced are among the most highly reduced naturally occurring materials known. Some occurrences of other highly reduced minerals may also be due to lightning strike reduction. Extreme reduction and volatilization may also occur during high-temperature events such as lightning strikes in presolar nebulae and impacts of extraterrestrial bodies. As a result of scavenging of platinum-group elements by highly reduced metallic liquids, geochemical anomalies associated with the Cretaceous-Tertiary boundary may have a significant terrestrial component even if produced through bolide impact. PMID:17746479

  7. One-step synthesis of layered yttrium hydroxides in immiscible liquid–liquid systems: Intercalation of sterically-bulky hydrophobic organic anions and doping of europium ions

    SciTech Connect

    Watanabe, Mebae; Fujihara, Shinobu

    2014-02-15

    Inorganic–organic layered rare-earth compounds were synthesized on the basis of a biphasic liquid–liquid system in one pot. Layered yttrium hydroxides (LYHs) were chosen as a host material for the intercalation of hydrophobic organic guest anions such as benzoate, sebacate, or laurate. In a typical synthesis, an organic phase dissolving carboxylic acid was placed in contact with an equal amount of an aqueous phase dissolving yttrium nitrate n-hydrate and urea. At elevated temperatures up to 80 °C, urea was hydrolyzed to release hydroxyl anions which were used to form yttrium hydroxide layers. LYHs were then precipitated with the intercalation of carboxylate anions delivered from the organic phase under the distribution law. The structure and the morphology of the LYHs could be modulated by the intercalated anions. Doped with Eu{sup 3+} ions, the LYHs exhibited red photoluminescence which was enhanced by the intercalated anions due to the antenna effect. - Graphical abstract: The Eu{sup 3+}-doped layered yttrium hydroxide exhibits intense red photoluminescence after intercalation of benzoate ions. Display Omitted - Highlights: • Immiscible biphasic liquid systems were introduced to synthesize layered yttrium hydroxides. • The temperature of the biphasic systems does not exceed 80 °C in one step of the synthesis. • Hydrophobic organic anions were intercalated between the hydroxide layers in one pot. • Structure and morphology of the hydroxides were modulated by changing the kind of organic anions. • Eu{sup 3+}-doping led to red luminescence from the hydroxides in association with the intercalated organic anions.

  8. Dynamics of a flowing liquid column with an immiscible reactive micellar interface

    NASA Astrophysics Data System (ADS)

    Niroobakhsh, Zahra; Belmonte, Andrew

    2015-11-01

    We experimentally investigate the instabilities resulting from the reactive formation of a thin layer of micellar material around a flowing liquid column. The material is produced when an aqueous surfactant solution (cetylpyridinium chloride) descends through a reservoir of oleic acid, a room temperature oil which can act as a weak surfactant. A variety of instabilities are observed, including connected and disconnected droplets, a straight cylindrical pipe which undergoes buckling, and various surface wave morphologies on the column. These states appear to be determined by a competition between surface tension and the growth of the interfacial material layer, as a function of imposed flow rate and surfactant concentration. Rheology provides evidence for the structural nature of the oleic/surfactant interaction, in the context of similar observations from other experiments.

  9. Characterizing the Use of Ultrasonic Energy in Promoting Uniform Microstructural Dispersions in Immiscible Mixtures

    NASA Technical Reports Server (NTRS)

    Grugel, R. N.; Fedoseyev, A. I.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    Gravity driven separation and preferential wetting precludes uniform microstructural distributions during solidification processing of immiscible, liquid-liquid mixtures. Historically, it is, however, established that liquid/liquid suspensions can be established and maintained by utilizing ultrasound. Following a brief introduction the results of experiments on immiscible mixtures subjected to ultrasonic energy during solidification processing will be compared and evaluated in view of a recently developed mathematical model. The presentation continues by discussion of scaling the model to commercial viability and concludes with the implications of such processing in a microgravity environment.

  10. Characterizing the Use of Ultrasonic Energy in Promoting Uniform Microstructural Dispersions in Immiscible Mixtures

    NASA Technical Reports Server (NTRS)

    Grugel, R. N.; Fedoseyev, A. I.; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    Gravity driven separation and preferential wetting precludes uniform microstructural distributions during solidification processing of immiscible, liquid-liquid mixtures. Historically, it is, however, established that liquid/liquid suspensions can be established and maintained by utilizing ultrasound. Following a brief introduction the results of experiments on immiscible mixtures subjected to ultrasonic energy during solidification processing will be compared and evaluated in view of a recently developed mathematical model. The presentation continues by discussion of scaling the model to commercial viability and concludes with the implications of such processing in a microgravity environment.

  11. Carbonate-silicate liquid immiscibility in the mantle propels kimberlite magma ascent

    NASA Astrophysics Data System (ADS)

    Kamenetsky, Vadim S.; Yaxley, Gregory M.

    2015-06-01

    Kimberlite is a rare volcanic rock renowned as the major host of diamonds and originated at the base of the subcontinental lithospheric mantle. Although kimberlite magmas are dense in crystals and deeply-derived rock fragments, they ascend to the surface extremely rapidly, enabling diamonds to survive. The unique physical properties of kimberlite magmas depend on the specific compositions of their parental melts that, in absence of historical eruptions and due to pervasive alteration of kimberlite rocks, remain highly debatable. We explain exceptionally rapid ascent of kimberlite magma from mantle depths by combining empirical data on the essentially carbonatite composition of the kimberlite primary melts and experimental evidence on interaction of the carbonate liquids with mantle minerals. Our experimental study shows that orthopyroxene is completely dissolved in a Na2CO3 melt at 2.0-5.0 GPa and 1000-1200 °C. The dissolution of orthopyroxene results in homogeneous silicate-carbonate melt at 5.0 GPa and 1200 °C, and is followed by unmixing of carbonate and carbonated silicate melts and formation of stable magmatic emulsion at lower pressures and temperatures. The dispersed silicate melt has a significant capacity for storing a carbonate component in the deep mantle (13 wt% CO2 at 2.0 GPa). We envisage that this component reaches saturation and is gradually released as CO2 bubbles, as the silicate melt globules are transported upwards through the lithosphere by the carbonatite magma. The globules of unmixed, CO2-rich silicate melt are continuously produced upon further reaction between the natrocarbonatite melt and mantle peridotite. On decompression the dispersed silicate melt phase ensures a continuous supply of CO2 bubbles that decrease density and increase buoyancy and promote rapid ascent of the magmatic emulsion.

  12. Partitioning of Nb, Mo, Ba, Ce, Pb, Th and U between immiscible carbonate and silicate liquids: Evaluating the effects of P2O5,F, and carbonate composition

    NASA Technical Reports Server (NTRS)

    Jones, J. H.; Walker, D.

    1993-01-01

    Previously we have reported carbonate liq./silicate liq. partition coefficients (D) for a standard suite of trace elements (Nb, Mo, Ba, Ce, Pb, Th, and U) and Ra and Pa as well. In brief, we have found that immiscible liquid partitioning is a strong function of temperature. As the critical temperature of the carbonate-silicate solvus is approached, all partition coefficients approach unity. Additionally, for the overwhelming majority of the partitioning elements, InD is a linear function of 'ionic field strength,' z/r, where z is the charge of the partitioned cation and r is its ionic radius.

  13. Liquid immiscibility between silicate, carbonate and sulfide melts in melt inclusions hosted in co-precipitated minerals from Kerimasi volcano (Tanzania): evolution of carbonated nephelinitic magma

    NASA Astrophysics Data System (ADS)

    Guzmics, Tibor; Mitchell, Roger H.; Szabó, Csaba; Berkesi, Márta; Milke, Ralf; Ratter, Kitti

    2012-07-01

    The evolution of a carbonated nephelinitic magma can be followed by the study of a statistically significant number of melt inclusions, entrapped in co-precipitated perovskite, nepheline and magnetite in a clinopyroxene- and nepheline-rich rock (afrikandite) from Kerimasi volcano (Tanzania). Temperatures are estimated to be 1,100°C for the early stage of the melt evolution of the magma, which formed the rock. During evolution, the magma became enriched in CaO, depleted in SiO2 and Al2O3, resulting in immiscibility at ~1,050°C and crustal pressures (0.5-1 GPa) with the formation of three fluid-saturated melts: an alkali- and MgO-bearing, CaO- and FeO-rich silicate melt; an alkali- and F-bearing, CaO- and P2O5-rich carbonate melt; and a Cu-Fe sulfide melt. The sulfide and the carbonate melt could be physically separated from their silicate parent and form a Cu-Fe-S ore and a carbonatite rock. The separated carbonate melt could initially crystallize calciocarbonatite and ultimately become alkali rich in composition and similar to natrocarbonatite, demonstrating an evolution from nephelinite to natrocarbonatite through Ca-rich carbonatite magma. The distribution of major elements between perovskite-hosted coexisting immiscible silicate and carbonate melts shows strong partitioning of Ca, P and F relative to FeT, Si, Al, Mn, Ti and Mg in the carbonate melt, suggesting that immiscibility occurred at crustal pressures and plays a significant role in explaining the dominance of calciocarbonatites (sövites) relative to dolomitic or sideritic carbonatites. Our data suggest that Cu-Fe-S compositions are characteristic of immiscible sulfide melts originating from the parental silicate melts of alkaline silicate-carbonatite complexes.

  14. Liquid-liquid immiscibility under non-equilibrium conditions in a model membrane: an X-ray synchrotron study.

    PubMed

    Tessier, Cedric; Staneva, Galya; Trugnan, Germain; Wolf, Claude; Nuss, Philippe

    2009-11-01

    Several non-random lipid mixtures have been proposed as models of lipid plasma membrane, as they mimic the ability of biomembranes to form lateral domains. Biological membranes are characterised by a succession of localised transient steady-state lipid organisations rather than stable equilibria. This suggests that several quasi at-equilibrium lipid organisations may exist at different times in the same local patch of membranes. Identification of the conditions which can mimic heterogeneous dynamic membrane states in a lipid membrane model is a challenge. This is of particular importance as the lateral organisation of lipids mixtures in fully equilibrated samples may differ from the arrangement found in quasi at-equilibrium conditions. To address this issue, we have performed a real-time synchrotron X-ray diffraction study in ternary mixtures of egg-phosphatidylcholine/egg-sphingomyelin and cholesterol using a 0.5 degrees C/15 s step within a 20-50-20 degrees C thermal cycle. In the present study, all ternary mixtures displayed lamellar phase separation. A d-spacing value was observed reversibly during the heating and cooling scan for each of the two coexisting phases. In mixtures with a cholesterol concentration from 20 to 50 mol%, a liquid-ordered (Lo) and liquid-disordered (Ld) phase separation was observed in the 20-50 degrees C thermal range. These results are discussed in terms of a specific interaction between lipid molecular aggregates. PMID:19720510

  15. Physical properties of immiscible polymers

    NASA Technical Reports Server (NTRS)

    Harris, J. Milton

    1987-01-01

    The demixing of immiscible polymers in low gravity is discussed. Applications of knowledge gained in this research will provide a better understanding of the role of phase segregation in determining the properties of polymer blends made from immiscible polymers. Knowledge will also be gained regarding the purification of biological materials by partitioning between the two liquid phases formed by solution of the polymers polyethylene glycol and dextran in water. Testing of new apparatus for space flight, extension of affinity phase partitioning, refinement of polymer chemistry, and demixing of isopycnic polymer phases in a one gravity environment are discussed.

  16. Method of removing an immiscible lubricant from a refrigeration system and apparatus for same

    DOEpatents

    Spauschus, Hans O.; Starr, Thomas L.

    1999-01-01

    A method of separating an immiscible lubricant from a liquid refrigerant in a refrigerating system including a compressor, a condenser, an expansion device and an evaporator, wherein the expansion device is connected to the condenser by a liquid refrigerant flow line for liquid refrigerant and immiscible lubricant. The method comprising slowing the rate of flow of the liquid refrigerant and immiscible lubricant between the condenser and the expansion device such that the liquid refrigerant and the immiscible lubricant separate based upon differences in density. The method also comprises collecting the separated immiscible lubricant in a collection chamber in fluid communication with the separated immiscible lubricant. Apparatus for performing the method is also disclosed.

  17. Enhancing distributive mixing of immiscible polyethylene/thermoplastic starch blend through zeolite ZSM-5 compounding sequence.

    PubMed

    Thipmanee, Ranumas; Lukubira, Sam; Ogale, Amod A; Sane, Amporn

    2016-01-20

    The aim of this work was to explore the effect of zeolite ZSM-5 (ZSM5) incorporation sequence on the phase morphology, microstructure, and performance of polyethylene/thermoplastic starch (PE/TPS) films. Two processing sequences were used for preparing PE/TPS/ZSM5 composites at a weight ratio of PE to TPS of 70:30 and ZSM5 concentrations of 1-5 wt%: (i) melt compounding of PE with ZSM5 prior to melt blending with TPS (SI); and (ii) TPS was compounded with ZSM5 prior to blending with PE (SII). Distributive mixing and mechanical properties of PE/TPS blend were greatly enhanced when ZSM5 was incorporated via SII. These were caused by both the higher affinity between PE and ZSM5, compared to that of TPS and ZSM5, and the reduction of TPS viscosity after compounding with ZSM5, leading to migration of ZSM5 from TPS dispersed phase toward PE matrix and increase in breakup of TPS droplets during SII sequence. PMID:26572416

  18. Immiscible Systems

    ERIC Educational Resources Information Center

    Eckelmann, Jens; Luning, Ulrich

    2013-01-01

    layers of liquids. The setup of both demonstrations is such that one homogeneous layer in a multiphasic mixture separates into two new layers upon shaking. The solvents used are methanol, toluene, petroleum ether or "n"-pentane, silicone oil, perfluoroheptanes,…

  19. A study of pressure-driven displacement flow of two immiscible liquids using a multiphase lattice Boltzmann approach

    NASA Astrophysics Data System (ADS)

    Redapangu, Prasanna; Vanka, Pratap; Sahu, Kirti

    2012-11-01

    The pressure-driven displacement of two immiscible fluids in an inclined channel in the presence of viscosity and density gradients is investigated using a multiphase lattice Boltzmann approach. The effects of viscosity ratio, Atwood number, Froude number, capillary number and channel inclination are investigated through flow structures, front velocities and fluid displacement rates. Our results indicate that increasing viscosity ratio between the fluids decreases the displacement rate. We observe that increasing the viscosity ratio has a non-monotonic effect on the velocity of the leading front; however, the velocity of the trailing edge decreases with increasing the viscosity ratio. The displacement rate of the thin-layers formed at the later times of the displacement process increases with increasing the angle of inclination because of the increase in the intensity of the interfacial instabilities. Our results also predict the front velocity of the lock-exchange flow of two immiscible fluids in the exchange flow dominated regime. Department of Science and Technology, India.

  20. Studies on immiscible alloys

    NASA Technical Reports Server (NTRS)

    Otto, G.

    1976-01-01

    To illustrate the behavior of immiscible liquids of different densities in zero-gravity and to determine the rate of coalescence like droplets, a demonstration experiment was performed on the Skylab 4 mission. Dispersions of oil-in-water and of water-in-oil were prepared by the astronauts and their appearance photographed over a time span of 10 hours. The experiment indicated that all emulsions were stable over this period and that the coalescent rate was at least 3 times 10 to the 5th power times smaller on Skylab than on earth. The recorded melting of a cylindrical piece of ice on Skylab 3 is used to study the mode of heat transfer for the latent heat of melting in low-gravity.

  1. Liquid carry-over in an injection moulded all-polymer chip system for immiscible phase magnetic bead-based solid-phase extraction

    NASA Astrophysics Data System (ADS)

    Kistrup, Kasper; Skotte Sørensen, Karen; Wolff, Anders; Fougt Hansen, Mikkel

    2015-04-01

    We present an all-polymer, single-use microfluidic chip system produced by injection moulding and bonded by ultrasonic welding. Both techniques are compatible with low-cost industrial mass-production. The chip is produced for magnetic bead-based solid-phase extraction facilitated by immiscible phase filtration and features passive liquid filling and magnetic bead manipulation using an external magnet. In this work, we determine the system compatibility with various surfactants. Moreover, we quantify the volume of liquid co-transported with magnetic bead clusters from Milli-Q water or a lysis-binding buffer for nucleic acid extraction (0.1 (v/v)% Triton X-100 in 5 M guanidine hydrochloride). A linear relationship was found between the liquid carry-over and mass of magnetic beads used. Interestingly, similar average carry-overs of 1.74(8) nL/μg and 1.72(14) nL/μg were found for Milli-Q water and lysis-binding buffer, respectively.

  2. Liquid-Phase Synthesis of Ba2V2O7 Phosphor Powders and Films Using Immiscible Biphasic Organic-Aqueous Systems.

    PubMed

    Takahashi, Mami; Hagiwara, Manabu; Fujihara, Shinobu

    2016-08-15

    A liquid-phase synthesis of inorganic phosphor materials at a moderate temperature was proposed by using immiscible liquid-liquid biphasic systems. A self-activated Ba2V2O7 phosphor was actually synthesized from vanadium alkoxide dissolved in an organic solution and barium acetate in an aqueous solution. A mild hydrolysis reaction of the alkoxide started at the organic-inorganic interface, and an intermediate compound, Ba(VO3)2·H2O, was initially formed. Ba2V2O7 powders were then obtained by the conversion from Ba(VO3)2·H2O promoted in the aqueous solution. Ba2V2O7 films were obtained on surface-modified silica glass substrates through the similar chemical reactions. Factors such as the surface state of substrates, the kind of organic solvents, and the volume of aqueous solutions were examined to improve the film deposition behavior. The resultant Ba2V2O7 materials showed broad-band visible photoluminescence upon irradiation with ultraviolet light based on the charge transfer transition in the VO4(3-) units existing as dimers. PMID:27472450

  3. Liquid immiscibility between arsenide and sulfide melts: evidence from a LA-ICP-MS study in magmatic deposits at Serranía de Ronda (Spain)

    NASA Astrophysics Data System (ADS)

    Piña, R.; Gervilla, F.; Barnes, S.-J.; Ortega, L.; Lunar, R.

    2015-03-01

    The chromite-Ni arsenide (Cr-Ni-As) and sulfide-graphite (S-G) deposits from the Serranía de Ronda (Málaga, South Spain) contain an arsenide assemblage (nickeline, maucherite and nickeliferous löllingite) that has been interpreted to represent an arsenide melt and a sulfide-graphite assemblage (pyrrhotite, pentlandite, chalcopyrite and graphite) that has been interpreted to represent a sulfide melt, both of which have been interpreted to have segregated as immiscible liquids from an arsenic-rich sulfide melt. We have determined the platinum-group element (PGE), Au, Ag, Se, Sb, Bi and Te contents of the arsenide and sulfide assemblages using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to establish their partitioning behaviour during the immiscibility of an arsenide melt from a sulfide melt. Previous experimental work has shown that PGE partition more strongly into arsenide melts than into sulfide melts and our results fit with this observation. Arsenide minerals are enriched in all PGE, but especially in elements with the strongest affinity for the arsenide melt, including Ir, Rh and Pt. In contrast and also in agreement with previous studies, Se and Ag partition preferentially into the sulfide assemblage. The PGE-depleted nature of sulfides in the S-G deposits along with the discordant morphologies of the bodies suggest that these sulfides are not mantle sulfides, but that they represent the crystallization product of a PGE-depleted sulfide melt due to the sequestering of PGE by an arsenide melt.

  4. Combination of corona discharge ion mobility spectrometry with a novel reagent gas and two immiscible organic solvent liquid-liquid-liquid microextraction for analysis of clomipramine in biological samples.

    PubMed

    Saraji, Mohammad; Bidgoli, Ali Akbar Hajialiakbari; Khayamian, Taghi; Moradmand, Ali

    2011-12-01

    A novel and sensitive method based on combination of two immiscible organic solvents hollow fiber-based liquid-liquid-liquid microextraction and corona discharge ion mobility spectrometry (HF-LLLME-CD-IMS) was employed for the analysis of clomipramine in human urine and plasma. The effect of formic, acetic and propionic acid as the reagent gas (dopant) on the corona discharge ion mobility signal was investigated. The influence of dopant amount was also studied. Optimum mass flow rates of the dopants were 3.7, 1.1 and 1.0 μmol min(-1) for formic, acetic and propionic acid, respectively. Experimental parameters influencing the extraction efficiency of HF-LLLME, such as NaOH concentration as donor solution, ionic strength of the sample, stirring rate, and extraction time were investigated and optimized. Under the optimum conditions, analytical parameters such as linearity, precision and limit of detection were also evaluated. The linear dynamic range was from 1 to 100 μg L(-1) (r(2)=0.9980) and the limit of detection was 0.35 μg L(-1). Intra- and inter-day precisions were satisfactory with a relative standard deviation (RSD) of 5.9 and 6.7%, respectively. The proposed method was satisfactorily applied for the determination of clomipramine in human plasma and urine. PMID:22041141

  5. Application of Proper Orthogonal Decomposition to the morphological analysis of confined co-axial jets of immiscible liquids with comparable densities

    NASA Astrophysics Data System (ADS)

    Charalampous, Georgios; Hardalupas, Yannis

    2014-11-01

    The development of a round liquid jet under the influence of a confined coaxial flow of an immiscible liquid of comparable density (central to annular flow density ratio of 8:10) was investigated in the vicinity of the nozzle exit. Two flow regimes were considered; one where the annular flow is faster than the central jet, so the central liquid jet is accelerated and one where the annular flow is slower, so the central liquid jet is decelerated. The central jet was visualised by high speed photography. Three modes of jet development were identified and classified in terms of the Reynolds number, Re, of the central jet which was in the range of 525 < Re < 2725, a modified definition of the Weber number, We, which allows the distinction between accelerating and deceleration flows and was in the range of -22 < We < 67 and the annular to central Momentum Ratio, MR, of the two streams which was in the range of 3.6 < MR < 91. By processing the time resolved jet images using Proper Orthogonal Decomposition (POD), it was possible to reduce the description of jet morphology to a small number of spatial modes, which isolated the most significant morphologies of the jet development. In this way, the temporal and spatial characteristics of the instabilities on the interface were clearly identified which highlights the advantages of POD over direct observation of the images. Relationships between the flow parameters and the interfacial waves were established. The wavelength of the interfacial instability was found to depend on the velocity of the fastest moving stream, which is contrary to findings for fluids with large density differences.

  6. One-dimensional immiscible displacement experiments

    NASA Astrophysics Data System (ADS)

    Thomson, N. R.; Graham, D. N.; Farquhar, G. J.

    1992-08-01

    In recent years, a great deal of attention has focused on the development of various methods to predict the fate of immiscible contaminants (NAPL's) in soils. In an attempt to satisfy this requirement, a host of numerical models has been developed. Unfortunately, there exist little experimental data to verify the assumptions used in the derivation of these immiscible flow models. One objective of this paper is to report on a non-destructive measurement technique which was used to capture the relative organic-phase saturation variations in a number of two-phase flow displacement experiments. The data obtained from these experiments were compared to results obtained from a one-dimensional, finite-element based, two-phase flow model. The experiments consisted of five separate trials using three different immiscible liquids (hydraulic oil, kerosene and hexane) in a water-saturated column. Irregular immiscible liquid infiltration fronts were observed in four of the five experiments, indicating that very small-scale heterogeneities control the infiltration of immiscible liquids into soil. Independent of the column experiments, saturation-capillary pressure curves were determined for the various liquids. In general, the simulated NAPL saturation vs. time profiles agreed very well with the observations for all five of the trials.

  7. Refolding effects of partially immiscible ammonium-based ionic liquids on the urea-induced unfolded lysozyme structure.

    PubMed

    Bisht, Meena; Kumar, Awanish; Venkatesu, Pannuru

    2016-05-14

    The activity of lysozyme over a Micrococcus lysodeikticus cell suspension increased to 13% of the initial value in the presence of 1% v/v ammonium-based ionic liquids after deactivation with 4.0 M urea. This increase in activity reflects the refolding ability of the ionic liquids against the denaturation effects of urea on lysozyme. PMID:27094019

  8. One-step synthesis of layered yttrium hydroxides in immiscible liquid-liquid systems: Intercalation of sterically-bulky hydrophobic organic anions and doping of europium ions

    NASA Astrophysics Data System (ADS)

    Watanabe, Mebae; Fujihara, Shinobu

    2014-02-01

    Inorganic-organic layered rare-earth compounds were synthesized on the basis of a biphasic liquid-liquid system in one pot. Layered yttrium hydroxides (LYHs) were chosen as a host material for the intercalation of hydrophobic organic guest anions such as benzoate, sebacate, or laurate. In a typical synthesis, an organic phase dissolving carboxylic acid was placed in contact with an equal amount of an aqueous phase dissolving yttrium nitrate n-hydrate and urea. At elevated temperatures up to 80 °C, urea was hydrolyzed to release hydroxyl anions which were used to form yttrium hydroxide layers. LYHs were then precipitated with the intercalation of carboxylate anions delivered from the organic phase under the distribution law. The structure and the morphology of the LYHs could be modulated by the intercalated anions. Doped with Eu3+ ions, the LYHs exhibited red photoluminescence which was enhanced by the intercalated anions due to the antenna effect.

  9. Development of a microfluidic-chip system for liquid-phase microextraction based on two immiscible organic solvents for the extraction and preconcentration of some hormonal drugs.

    PubMed

    Asl, Yousef Abdossalami; Yamini, Yadollah; Seidi, Shahram

    2016-11-01

    In the present study, for the first time, an on-chip liquid phase microextraction (LPME) coupled with high performance liquid chromatography was introduced for the analysis of levonorgestrel (Levo), dydrogesterone (Dydo) and medroxyprogesterone (Medo) as the model analytes in biological samples. The chip-based LPME set-up was composed of two polymethyl methacrylate (PMMA) plates with microfabricated channels and a microporous membrane sandwiched between them to separate the sample solution and acceptor phase. These channels were used as a flow path for the sample solution and a thin compartment for the acceptor phase, respectively. In this system, two immiscible organic solvents were used as supported liquid membrane (SLM) and acceptor phase, respectively. During extraction, the model analytes in the sample solution were transported through the SLM (n-dodecane) into the acceptor organic solvent (methanol). The new set-up provided effective and reproducible extractions using low volumes of the sample solution. The effective parameters on the extraction efficiency of the model analytes were optimized using one variable at a time method. Under the optimized conditions, the new set-up provided good linearity in the range of 5.0-500µgL(-1) for the model analytes with the coefficients of determination (r(2)) higher than 0.9909. The relative standard deviations (RSDs%) and limits of detection (LODs) values were less than 6.5% (n=5) and 5.0µgL(-1), respectively. The preconcentration factors (PFs) were obtained using 1.0mL of the sample solution and 20.0µL of the acceptor solution higher than 19.9-fold. Finally, the proposed method was successfully applied for the extraction and determination of the model analytes in urine samples. PMID:27591655

  10. Low gravity containerless processing of immiscible gold rhodium alloys

    NASA Technical Reports Server (NTRS)

    Andrews, J. Barry

    1986-01-01

    Under normal one-g conditions immiscible alloys segregate extensively during solidification due to sedementation of the more dense of the immiscible liquid phases. However, under low-g conditions it should be possible to form a dispersion of the two immiscible liquids and maintain this dispersed structure during solidification. Immiscible (hypermonotectic) gold-rhodium alloys were processed in the Marshall Space Flight Center 105 meter drop tube in order to investigate the influence of low gravity, containerless solidification on their microstructure. Hypermonotectic alloys composed of 65 atomic % rhodium exhibited a tendency for the gold rich liquid to wet the outer surface of the containerless processed samples. This tendency led to extensive segregation in several cases. However, well dispersed microstructures consisting of 2 to 3 micron diameter rhodium-rich spheres in a gold-rich matrix were produced in 23.4 atomic % rhodium alloys. This is one of the best dispersions obtained in research on immiscible alloy-systems to data.

  11. More About Measuring Interfacial Tension Between Liquids

    NASA Technical Reports Server (NTRS)

    Rashidnia, Nasser; Balasubramaniam, R.; Del Signore, David M.

    1995-01-01

    Report presents additional discussion of technique for measuring interfacial tension between two immiscible liquids. Technique described in "Measuring Interfacial Tension Between Immiscible Liquids" (LEW-15855).

  12. Effects of crucible wetting during solidification of immiscible Pb-Zn

    NASA Technical Reports Server (NTRS)

    Degroh, Henry C., III; Probst, Hubert B.

    1988-01-01

    Many industrial uses for liquid phase miscibility gap alloys are proposed. However, the commercial production of these alloys into useful ingots with a reasonable amount of homogeneity is arduous because of their immiscibility in the liquid state. In the low-g environment of space gravitational settling forces are abated, thus solidification of an immiscible alloys with a uniform distribution of phases becomes feasible. Elimination of gravitational settling and coalescence processes in low-g also makes possible the study of other separation and coarsening mechanisms. Even with gravitational separation forces reduced, many low-g experiments have resulted in severely segregated structures. The segregation in many cases was due to preferential wetting of the crucible by one of the immiscible liquids. The objective was to analyze the wetting behavior of Pb-Zn alloys on various crucible materials in an effort to identify a crucible in which the fluid flow induced by preferential wetting is minimized. It is proposed that by choosing the crucible for a particular alloy so that the difference in surface energy between the solid and two liqud phases is minimized, the effects of preferential wetting can be diminished and possibly avoided. Qualitative experiments were conducted and have shown the competitive wetting behavior of the immiscible Pb-Zn system and 13 different crucible materials.

  13. Method of removing an immiscible lubricant from a refrigeration system and apparatus for same

    DOEpatents

    Spauschus, H.O.; Starr, T.L.

    1999-03-30

    A method is described for separating an immiscible lubricant from a liquid refrigerant in a refrigerating system including a compressor, a condenser, an expansion device and an evaporator, wherein the expansion device is connected to the condenser by a liquid refrigerant flow line for liquid refrigerant and immiscible lubricant. The method comprising slowing the rate of flow of the liquid refrigerant and immiscible lubricant between the condenser and the expansion device such that the liquid refrigerant and the immiscible lubricant separate based upon differences in density. The method also comprises collecting the separated immiscible lubricant in a collection chamber in fluid communication with the separated immiscible lubricant. Apparatus for performing the method is also disclosed. 3 figs.

  14. Liquid distribution in trickle bed reactors

    SciTech Connect

    Sundaresan, S.

    1993-12-31

    The quality of liquid distribution at the top of the bed and the manner in which the flows are established can affect the liquid flow behavior profoundly. This, in turn, can impact the rates of chemical reactions. Some recent experimental results highlighting these points are reviewed.

  15. THE LIQUID AND GASEOUS FUEL DISTRIBUTION SYSTEM

    EPA Science Inventory

    The report describes the national liquid and gaseous fuel distribution system. he study leading to the report was performed as part of an effort to better understand emissions of volatile organic compounds from the fuel distribution system. he primary, secondary, and tertiary seg...

  16. LIQUID AND GASEOUS FUEL DISTRIBUTION SYSTEM

    EPA Science Inventory

    The report describes the national liquid and gaseous fuel distribution system. he study leading to the report was performed as part of an effort to better understand emissions of volatile organic compounds from the fuel distribution system. he primary, secondary, and tertiary seg...

  17. Partitioning of elements between silicate melt and immiscible fluoride, chloride, carbonate, phosphate and sulfate melts, with implications to the origin of natrocarbonatite

    NASA Astrophysics Data System (ADS)

    Veksler, Ilya V.; Dorfman, Alexander M.; Dulski, Peter; Kamenetsky, Vadim S.; Danyushevsky, Leonid V.; Jeffries, Teresa; Dingwell, Donald B.

    2012-02-01

    Liquid-liquid partitioning of 42 elements between synthetic silicate melts and immiscible fluoride, chloride, carbonate, phosphate and sulfate liquids was studied at temperatures of 650-1100 °C, pressures 72-100 MPa, with 0-11 wt.% H2O. One series of experiments was performed in a rotating internally-heated autoclave where separation of the immiscible liquids was assisted by centrifugal forces. An analogous series of experiments was done in static rapid-quench cold-seal pressure vessels. The experimentally determined liquid-liquid distribution coefficients (D's) vary over several orders of magnitude, as a result of variable Coulombic interactions between cations and anions. For alkaline, alkaline earth and rare earth elements ther is a strong and systematic dependence of the liquid/liquid D values on the ionic potential Z/r for all the examined systems. In contrast, highly charged cations (e.g., HFSE) show no systematic relationships between the D's and Z/r. New experimental constraints on the carbonate/silicate liquid-liquid D values presented here confirm that rare metals such as Nb, Zr, REE, Th and U concentrate in silicate liquids, and therefore carbonatites that carry economical rare metal mineralization are not likely to have formed by liquid immiscibility. The comparison between experimentally-determined carbonate-silicate liquid-liquid D values and bulk-rock natrocarbonatite vs. nephelinite compositions at the Oldoinyo Lengai in Tanzania reveals significant discrepancies for Cs, Rb, Ba, Be, Zn, heavy REE, Ti, Mo and W, thus rendering a simple, one-stage immiscibility model for Oldoinyo Lengai questionable.

  18. Ultrathin-skinned asymmetric membranes by immiscible solvents treatment

    DOEpatents

    Friesen, Dwayne T.; Babcock, Walter C.

    1989-01-01

    Improved semipermeable asymmetric fluid separation membranes useful in gas, vapor and liquid separations are disclosed. The membranes are prepared by substantially filling the pores of asymmetric cellulosic semipermeable membranes having a finely porous layer on one side thereof with a water immiscible organic liquid, followed by contacting the finely porous layer with water.

  19. Ultrathin-skinned asymmetric membranes by immiscible solvents treatment

    DOEpatents

    Friesen, D.T.; Babcock, W.C.

    1989-11-28

    Improved semipermeable asymmetric fluid separation membranes useful in gas, vapor and liquid separations are disclosed. The membranes are prepared by substantially filling the pores of asymmetric cellulosic semipermeable membranes having a finely porous layer on one side thereof with a water immiscible organic liquid, followed by contacting the finely porous layer with water.

  20. Quantification of immiscible fluid distribution of an oil-wet and water-wet bead pack imaged using x-ray computed microtomography

    NASA Astrophysics Data System (ADS)

    Landry, C. J.; Karpyn, Z. T.; Piri, M.

    2009-12-01

    history hysteresis and a zone of distinct saturation history hysteresis. The meniscus specific interfacial area of the fluids is shown to trend towards a maximum at a brine saturation of 0.25 to 0.40, in good agreement with previously reported values, regardless of saturation history and wettability. The total specific interfacial area of the fluids is shown to correlate linearly with non-wetting phase saturation, independent of fluid distribution zone, saturation history and wettability. The fluid-normalized specific interfacial areas are shown to be nearly constant, independent of saturation, saturation history and wettability. Furthermore a population analysis of individual blob volume, surface area, shape, aspect ratio and orientation provides insight into the effect of wettability on immiscible fluid microstructure. The agreement between our measurements and others conducted with natural soils, sands and rock cores is promising for furthering our understanding of how pore-scale processes influence macroscale properties used to describe multiphase flow and transport.

  1. The nature and barium partitioning between immiscible melts - A comparison of experimental and natural systems with reference to lunar granite petrogenesis

    NASA Technical Reports Server (NTRS)

    Neal, C. R.; Taylor, L. A.

    1989-01-01

    Elemental partitioning between immiscible melts has been studied using experimental liquid-liquid Kds and those determined by analysis of immiscible glasses in basalt mesostases in order to investigate lunar granite petrogenesis. Experimental data show that Ba is partitioned into the basic immiscible melt, while probe analysis results show that Ba is partitioned into the granitic immiscible melt. It is concluded that lunar granite of significant size can only occur in a plutonic or deep hypabyssal environment.

  2. Electrified microscopic and conventional interfaces between two immiscible electrolyte solutions

    NASA Astrophysics Data System (ADS)

    Vanysek, Petr

    1991-06-01

    Transport studies on interfaces between immiscible phases bridges the field of heterogeneous electrode electrochemistry and that of homogeneous solution chemistry. Early work on liquid/liquid boundary was concerned with large area (order of a square centimeter) interfaces. Recent studies investigate phenomena on interfaces rendered in pores, capillaries, and small holes. The behavior of such interfaces in the presence of dodecyl sulfate, forming micelles, is investigated. Voltammetry and amperometry on these small interfaces reveals that the accompanying voltammetric characteristics are similar to that of metal ultramicroelectrodes. Potentiometric studies of dodecyl sulfate on water/nitrobenzene and aqueous polymer immiscible interfaces allow determination of critical micelle concentration.

  3. Studies of Model Immiscible Systems

    NASA Technical Reports Server (NTRS)

    Frazier, D. O.; Facemire, B. R.; Witherow, W. K.; Fanning, U.; Kaukler, W. F.

    1985-01-01

    The objectives are to use model transparent monotectics to obtain fundamental information applicable to two-phase systems in general, to apply this understanding to materials of interest in the Microgravity Science and Applications program, and to interpret results of flight experimental involving monotectic alloys. A number of model immiscible systems are in use to study various aspects of two-phase behavior within the miscibility gap and during solidification. Particle growth, coalescence and particle motions are under investigation using a holographic microscopy system. The system is capable of working with particle densities up to 10 to the 7th power particles/cubic centimeters through a 100 micron depth and can resolve particles of the order of 2 to 3 micron in diameter throughout the entire cell volume. Particle size, distribution changes with respect to time and temperature are observable from sequential holograms. Initial experiments using diethylene glycol/ethyl salicylate (DEG/ES) have demonstrated the usefulness of the technique. The thermal system controls temperature to at least plus or minus 0.001 K over the course of an experiment. A time-lapse film, made from holograms, of a succinonitrile/water solution shows particle size and number distribution changes with time under isothermal conditions. The observations are consistent with Ostwald ripening theory.

  4. Containerless low gravity processing of glass forming and immiscible alloys

    NASA Technical Reports Server (NTRS)

    Andrews, J. Barry; Briggs, Craig; Robinson, M. B.

    1990-01-01

    Under normal one-g conditions immiscible alloys segregate extensively during solidification due to sedimentation of the more dense of the immiscible liquid phases. Immiscible (hypermonotectic) gold-rhodium alloys were processed in the 100 meter drop tube under low gravity, containerless conditions to determine the feasibility of producing dispersed structures. Three alloy compositions were utilized. Alloys containing 10 percent by volume of the gold-rich hypermonotectic phase exhibited a tendency for the gold-rich liquid to wet the outer surface of the samples. This wetting tendency led to extensive segregation in several cases. Alloys containing 80 and 90 percent by volume of the gold-rich phase possessed completely different microstructures from the 10 percent samples when processed under low-g, containerless conditions. Several samples exhibited microstructures consisting of well dispersed 2 to 3 microns diameter rhodium-rich spheres in a gold-rich matrix.

  5. Silicate-carbonate-salt liquid immiscibility and origin of the sodalite-haüyne rocks: study of melt inclusions in olivine foidite from Vulture volcano, S. Italy

    NASA Astrophysics Data System (ADS)

    Panina, Liya; Stoppa, Francesco

    2009-12-01

    Melt inclusions in clinopyroxenes of olivine foidite bombs from Serra di Constantinopoli pyroclastic flows of the Vulture volcano (Southern Italy) were studied in detail. The rocks contain abundant zoned phenocrysts and xenocrysts of clinopyroxene, scarce grains of olivine, leucite, haüyne, glass with microlites of plagioclase and K-feldspar. The composition of clinopyroxene in xenocrysts (Cpx I), cores (Cpx II), and in rims (Cpx III) of phenocrysts differs in the content of Mg, Fe, Ti, and Al. All clinopyroxenes contain two types of primary inclusion-pure silicate and of silicate-carbonate-salt composition. This fact suggests that the phenomena of silicate-carbonate immiscibility took place prior to crystallization of clinopyroxene. Homogenization of pure silicate inclusions proceeded at 1 225 - 1 190°C. The composition of conserved melts corresponded to that of olivine foidite in Cpx I, to tephrite-phonolite in Cpx II, and phonolite-nepheline trachyte in Cpx III. The amount of water in them was no more than 0.9 wt.%. Silicate-carbonate inclusions decrepitated on heating. Salt globules contained salts of alkali-sulphate, alkali-carbonate, and Ca-carbonate composition somewhat enriched in Ba and Sr. This composition is typical of carbonatite melts when decomposed into immiscible fractions. The formation of sodalite-haüyne rocks from Vulture is related to the presence of carbonate-salt melts in magma chamber. The melts conserved in clinopyroxenes were enriched in incompatible elements, especially in Cpx III. High ratios of La, Nb, and Ta in melts on crystallization of Cpx I and Cpx II suggest the influence of a carbonatite melt as carbonatites have extremely high La/Nb and Nb/Ta and this is confirmed by the appearance of carbonatite melts in magma chamber. Some anomalies in the concentrations and relatives values of Eu and especially Ga seems typical of Italian carbonatite related melts. The mantle source for initial melts was, most likely, rather uniform

  6. FINITE-ELEMENT ANALYSIS OF MULTIPHASE IMMISCIBLE FLOW THROUGH SOILS

    EPA Science Inventory

    A finite-element model is developed for multiphase flow through soil involving three immiscible fluids: namely, air, water, and a nonaqueous phase liquid (NAPL). A variational method is employed for the finite-element formulation corresponding to the coupled differential equation...

  7. FIELD TEST OF CYCLODEXTRIN FOR ENHANCED IN-SITU FLUSHING OF MULTIPLE-COMPONENT IMMISCIBLE ORGANIC LIQUID CONTAMINATION: COMPARISON TO WATER FLUSHING

    EPA Science Inventory

    A pilot-scale field experiment was conducted to compare the remediation effectiveness of an enhanced-solubilization technique to that of water flushing for removal of multicomponent nonaqueous-phase organic liquid (NAPL) contaminants form a phreatic aquifer. This innovative remed...

  8. Mixing of immiscible polymers using nanoporous coordination templates

    PubMed Central

    Uemura, Takashi; Kaseda, Tetsuya; Sasaki, Yotaro; Inukai, Munehiro; Toriyama, Takaaki; Takahara, Atsushi; Jinnai, Hiroshi; Kitagawa, Susumu

    2015-01-01

    The establishment of methodologies for the mixing of immiscible substances is highly desirable to facilitate the development of fundamental science and materials technology. Herein we describe a new protocol for the compatibilization of immiscible polymers at the molecular level using porous coordination polymers (PCPs) as removable templates. In this process, the typical immiscible polymer pair of polystyrene (PSt) and poly(methyl methacrylate) (PMMA) was prepared via the successive homopolymerizations of their monomers in a PCP to distribute the polymers inside the PCP particles. Subsequent dissolution of the PCP frameworks in a chelator solution affords a PSt/PMMA blend that is homogeneous in the range of several nanometers. Due to the unusual compatibilization, the thermal properties of the polymer blend are remarkably improved compared with the conventional solvent-cast blend. This method is also applicable to the compatibilization of PSt and polyacrylonitrile, which have very different solubility parameters. PMID:26130294

  9. Mixing of immiscible polymers using nanoporous coordination templates.

    PubMed

    Uemura, Takashi; Kaseda, Tetsuya; Sasaki, Yotaro; Inukai, Munehiro; Toriyama, Takaaki; Takahara, Atsushi; Jinnai, Hiroshi; Kitagawa, Susumu

    2015-01-01

    The establishment of methodologies for the mixing of immiscible substances is highly desirable to facilitate the development of fundamental science and materials technology. Herein we describe a new protocol for the compatibilization of immiscible polymers at the molecular level using porous coordination polymers (PCPs) as removable templates. In this process, the typical immiscible polymer pair of polystyrene (PSt) and poly(methyl methacrylate) (PMMA) was prepared via the successive homopolymerizations of their monomers in a PCP to distribute the polymers inside the PCP particles. Subsequent dissolution of the PCP frameworks in a chelator solution affords a PSt/PMMA blend that is homogeneous in the range of several nanometers. Due to the unusual compatibilization, the thermal properties of the polymer blend are remarkably improved compared with the conventional solvent-cast blend. This method is also applicable to the compatibilization of PSt and polyacrylonitrile, which have very different solubility parameters. PMID:26130294

  10. Miscible and immiscible experiments on the Rayleigh-Taylor instability using planar laser induced fluorescence visualization

    NASA Astrophysics Data System (ADS)

    Mokler, Matthew; Roberts, Michael; Jacobs, Jeffrey

    2013-11-01

    Incompressible Rayleigh-Taylor instability experiments are presented in which two stratified liquids having Atwood number of 0.2 are accelerated in a vertical linear induction motor driven drop tower. A test sled having only vertical freedom of motion contains the experiment tank and visualization equipment. The sled is positioned at the top of the tower within the linear induction motors and accelerated downward causing the initially stable interface to be unstable and allowing the Rayleigh-Taylor instability to develop. Forced and unforced experiments are conducted using both immiscible and miscible liquid combinations. Forced initial perturbations are produced by vertically oscillating the test sled prior to the start of acceleration. The interface is visualized using a 445 nm laser light source that illuminates a fluorescent dye mixed in one of the fluids. The resulting fluorescent images are recorded using a monochromatic high speed video camera. The laser beam is synchronously swept across the fluorescent fluid, at the frame rate of the camera, exposing a single plane of the interface allowing for the measurement of spike and bubble growth. Comparisons between miscible and immiscible mixing layer distributions are made from the resulting interface concentration profiles.

  11. Deformation of a partially engulfed compound drop slowly moving in an immiscible viscous fluid

    NASA Astrophysics Data System (ADS)

    Rosenfeld, L.; Lavrenteva, O. M.; Spivak, R.; Nir, A.

    2011-02-01

    Compound drops are comprised of two or more immiscible phases, one of which entirely or partially engulfs the others. In this work, we consider a partially engulfed compound drop comprised of two immiscible incompressible fluids, dispersed in an isothermal liquid, and that moved under the action of gravity and buoyancy. The contact angles between the three phases are determined by three interfacial tensions associated with the different fluids comprising the compound drop. The surfaces deform as the drop moves through the ambient fluid. If the capillary number is small (Ca≪1), corrections to the shapes of the undeformable case (Ca=0) are constructed, making use of a perturbation technique. We report on stationary drops' deformation for a variety of the physical parameters involved, such as volume ratio and surface tension of each interface, which determine the unperturbed configuration and the distribution of density between the two phases of the drop. Several examples of various transient behaviors of highly deformable compound drops are computed using FLUENT software and are presented as well.

  12. Liquid-liquid distribution of B group vitamins in polyethylene glycol-based systems

    NASA Astrophysics Data System (ADS)

    Korenman, Ya. I.; Zykov, A. V.; Mokshina, N. Ya.

    2011-05-01

    General regularities of the liquid-liquid distribution of B1, B2, B6, and B12 vitamins in aqueous polyethylene glycol (PEG-2000, PEG-5000) solution-aqueous salt solution systems are studied. The influence of the salting-out agent, the concentration of the polymer, and its molecular weight on the distribution coefficients and recovery factors of the vitamins are considered. Equations relating the distribution coefficients (log D) to the polymer concentration are derived.

  13. Identification of Gravity-Related Effects on Crystal Growth From Melts With an Immiscibility Gap

    NASA Technical Reports Server (NTRS)

    Kassemi, M.; Sayir, A.; Farmer, S.

    1999-01-01

    This work involves an experimental-numerical approach to study the effects of natural and Marangoni convections on solidification of single crystals from a silicate melt with a liquid-liquid immiscibility gap. Industrial use of crystals grown from silicate melts is becoming increasingly important in electronic, optical, and high temperature structural applications. Even the simplest silicate systems like Al203-SiO2 have had, and will continue to have, a significant role in the development of traditional and advanced ceramics. A unique feature of crystals grown from the silicate systems is their outstanding linear electro-optic properties. They also exhibit exceptionally high optical rotativity. As a result, these crystals are attractive materials for dielectric, optical, and microwave applications. Experimental work in our laboratory has indicated that directional solidification of a single crystal mullite appears to be preceded by liquid-liquid phase separation in the melt. Disruption of the immiscible state results in crystallization of a two phase structure. There is also evidence that mixing in the melt caused by density-driven convection can significantly affect the stability of the immiscible liquid layers and result in poly-crystalline growth. On earth, the immiscible state has only been observed for small diameter crystals grown in float zone systems where natural convection is almost negligible. Therefore, it is anticipated that growth of large single crystals from silicate melts would benefit from microgravity conditions because of the reduction of the natural convective mixing. The main objective of this research is to determine the effects of transport processes on the phase separation in the melt during growth of a single crystal while addressing the following issues: (1) When do the immiscible layers form and are they real?; (2) What are the main physical characteristics of the immiscible liquids?; and (3) How mixing by natural or Marangoni convection

  14. Characteristics of liquid-liquid immiscibility in Al-Bi-Cu, Al-Bi-Si, and Al-Bi-Sn monotectic alloys: Differential scanning calorimetry, interfacial tension, and density difference measurements

    NASA Astrophysics Data System (ADS)

    Kaban, Ivan G.; Hoyer, Walter

    2008-03-01

    Phase separation in ternary monotectic alloys (Al0.345Bi0.655)90X10 ( X=Cu,Si,Sn ; wt %) has been investigated. Experimental work included differential scanning calorimetry and measurements of the liquid-liquid (l-l) interfacial tension and difference in densities of coexisting phases. It is established that the interfacial tension between Al-rich and Bi-rich liquid phases increases when either Cu or Si is added and it decreases when Sn is added to the Al34.5Bi65.5 binary. This is related to the size of miscibility gap and is explained by increasing composition gradient across the (l-l) interface upon addition of either Cu or Si and its decreasing upon addition of Sn to the Al-Bi binary. The drop of interfacial tension in liquid (Al0.345Bi0.655)90Sn10 against Al34.5Bi65.5 is also caused by adsorption of Sn at the interface. Temperature dependences of the interfacial tension and density difference in the alloys studied follow a power law in reduced temperature (TC-T) at approach of the critical point with exponents close to the values predicted by the renormalization group theory of critical behavior.

  15. NMR imaging of immiscible displacements in porous media

    SciTech Connect

    Majors, P.D.; Li, P.; Peters, E.J.

    1995-12-31

    We introduce a rapid, quantitative nuclear magnetic resonance imaging (NMRI) technique to resolve and measure multiple fluid phases in porous media. Liquids are resolved on the basis of their NMR spin-spin (T{sub 2}) relaxation times, and their intensities are corrected via attenuation analysis. The spatially resolved and corrected NMRI intensities are normalized to yield fluid saturations. In-situ saturation measurements are presented for three immiscible (oil and water) displacements in the same Berea sandstone core. NMRI and effluent recovery methods were compared. T{sub 2} of the displacement fluids were observed to be sensitive to displacement conditions.

  16. Interfacial tension in immiscible mixtures of alkali halides.

    PubMed

    Lockett, Vera; Rukavishnikova, Irina V; Stepanov, Victor P; Tkachev, Nikolai K

    2010-02-01

    The interfacial tension of the liquid-phase interface in seven immiscible reciprocal ternary mixtures of lithium fluoride with the following alkali halides: CsCl, KBr, RbBr, CsBr, KI, RbI, and CsI was measured using the cylinder weighing method over a wide temperature range. It was shown that for all mixtures the interfacial tension gradually decreases with growing temperature. The interfacial tension of the reciprocal ternary mixtures at a given temperature increases both with the alkali cation radius (K(+) < Rb(+) < Cs(+)) and with the radius of the halogen anion (Cl(-) < Br(-) < I(-)). PMID:20094678

  17. Immiscible Lattice Gas with Long-Range Interaction

    NASA Astrophysics Data System (ADS)

    Tsumaya, Akira; Ohashi, Hirotada

    We developed a new LGA model which has the applicability for simulation of immiscible two phases with wide difference in density. We introduced long-range interparticle forces into the Rothman and Keller's ILG model to represent density difference between phases. We attempted some simulations of phase separation using our new model. Two-phase interfaces are stably made with density distribution coinciding with particle color distribution. Furthermore, the two-phase interface is clearer than that obtained by the Appert and Zaleski's LG model.

  18. Terahertz absorption spectra and potential energy distribution of liquid crystals.

    PubMed

    Chen, Zezhang; Jiang, Yurong; Jiang, Lulu; Ma, Heng

    2016-01-15

    In this work, the terahertz (THz) absorption spectra of a set of nematic liquid crystals were studied using the density functional theories (DFT). An accurate assignment of the vibrational modes corresponding to absorption frequencies were performed using potential energy distribution (PED) in a frequency range of 0-3 THz. The impacts of different core structures on THz absorption spectra were discussed. The results indicate that scope of application must be considered in the LC-based THz device designing. This proposed work may give a useful suggestion on the design of novel liquid crystal material in THz wave. PMID:26476072

  19. A Study of Undercooling Behavior Of Immiscible Metal Alloys in the Absence of Crucible-Induced Nucleation

    NASA Technical Reports Server (NTRS)

    Robinson, Michael B.; Rathz, Thomas J.; Li, Delin; Workman, Gary

    1998-01-01

    The purpose of this study is to investigate the question: Would eliminating the crucible eliminate the wall-induced nucleation of one of the liquid phases in an immiscible alloy and result in undercooling of the liquid into the metastable region thereby producing significant differences in the separation process and the microstructure upon solidification. Another primary objective of this research is to study systems with a metastable miscibility gap and to directly determine the metastable liquid miscibility gap by undercooling experiments. Nucleation and growth of droplets in these undercooled metallic liquid-liquid mixtures is also being studied. Results of this investigation indicate that containerless processing of immiscibles may not promote the undercooling of the single-phase liquid into the metastable region. Although no recalescence event was observed for this liquid-liquid transition, undercooling did occur across the miscibility gap for the solidification of the Ti phase that eventually separated.

  20. 26 CFR 1.332-5 - Distributions in liquidation as affecting minority interests.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 4 2011-04-01 2011-04-01 false Distributions in liquidation as affecting... TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Corporate Liquidations § 1.332-5 Distributions in liquidation as affecting minority interests. Upon the liquidation of a corporation in pursuance of a plan...

  1. Pair distribution function study on compression of liquid gallium

    SciTech Connect

    Luo, Shengnian; Yu, Tony; Chen, Jiuhua; Ehm, Lars; Guo, Quanzhong; Parise, John

    2008-01-01

    Integrating a hydrothermal diamond anvil cell (HDAC) and focused high energy x-ray beam from the superconductor wiggler X17 beamline at the National Synchrotron Light Source (NSLS) at the Brookhaven National Laboratory (BNL), we have successfully collected high quality total x-ray scattering data of liquid gallium. The experiments were conducted at a pressure range from 0.1GPa up to 2GPa at ambient temperature. For the first time, pair distribution functions (PDF) for liquid gallium at high pressure were derived up to 10 {angstrom}. Liquid gallium structure has been studied by x-ray absorption (Di Cicco & Filipponi, 1993; Wei et al., 2000; Comez et al., 2001), x-ray diffraction studies (Waseda & Suzuki, 1972), and molecular dynamics simulation (Tsay, 1993; Hui et al., 2002). These previous reports have focused on the 1st nearest neighbor structure, which tells us little about the atomic arrangement outside the first shell in non- crystalline materials. This study focuses on the structure of liquid gallium and the atomic structure change due to compression. The PDF results show that the observed atomic distance of the first nearest neighbor at 2.78 {angstrom} (first G(r) peak and its shoulder at the higher Q position) is consistent with previous studies by x-ray absorption (2.76 {angstrom}, Comez et al., 2001). We have also observed that the first nearest neighbor peak position did not change with pressure increasing, while the farther peaks positions in the intermediate distance range decreased with pressure increasing. This leads to a conclusion of the possible existence of 'locally rigid units' in the liquid. With the addition of reverse Monte Carlo modeling, we have observed that the coordination number in the local rigit unit increases with pressure. The bulk modulus of liquid gallium derived from the volume compression curve at ambient temperature (300K) is 12.1(6) GPa.

  2. 26 CFR 1.332-5 - Distributions in liquidation as affecting minority interests.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 4 2012-04-01 2012-04-01 false Distributions in liquidation as affecting... Distributions in liquidation as affecting minority interests. Upon the liquidation of a corporation in pursuance... without regard to section 332, since it does not apply to that part of distributions in...

  3. 26 CFR 1.332-5 - Distributions in liquidation as affecting minority interests.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 4 2014-04-01 2014-04-01 false Distributions in liquidation as affecting... Distributions in liquidation as affecting minority interests. Upon the liquidation of a corporation in pursuance... without regard to section 332, since it does not apply to that part of distributions in...

  4. 26 CFR 1.332-5 - Distributions in liquidation as affecting minority interests.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 4 2013-04-01 2013-04-01 false Distributions in liquidation as affecting... Distributions in liquidation as affecting minority interests. Upon the liquidation of a corporation in pursuance... without regard to section 332, since it does not apply to that part of distributions in...

  5. A novel coarsening mechanism of droplets in immiscible fluid mixtures

    NASA Astrophysics Data System (ADS)

    Shimizu, Ryotaro; Tanaka, Hajime

    2015-06-01

    In our daily lives, after shaking a salad dressing, we see the coarsening of oil droplets suspended in vinegar. Such a demixing process is observed everywhere in nature and also of technological importance. For a case of high droplet density, domain coarsening proceeds with inter-droplet collisions and the resulting coalescence. This phenomenon has been explained primarily by the so-called Brownian-coagulation mechanism: stochastic thermal forces exerted by molecules induce random motion of individual droplets, causing accidental collisions and subsequent interface-tension-driven coalescence. Contrary to this, here we demonstrate that the droplet motion is not random, but hydrodynamically driven by the composition Marangoni force due to an interfacial tension gradient produced in each droplet as a consequence of composition correlation among droplets. This alters our physical understanding of droplet coarsening in immiscible liquid mixtures on a fundamental level.

  6. Immiscible fluids in mixed wet porous media: the role of wettability correlations

    NASA Astrophysics Data System (ADS)

    Murison, Julie; Semin, Benoit; Baret, Jean-Christophe; Herminghaus, Stephan; Schroeter, Matthias; Brinkmann, Martin

    2013-11-01

    Various phenomena observed during immiscible displacement in a porous medium can be related to pore wall wettability. Petroleum engineers traditionally quantify the overall wettability of a rock sample in terms of the Ammot-Harvey or USBM index. To establish a link between these gloabl quantities and the pore-scale distribution of surface energies, we developed a series of model porous media. Using a variety of preparation methods, we are able to create dense beds of glass beads with the same average surface energy, differing only in the typical extension of the wetting and non-wetting surface domains. Experimental measurements of capillary pressure saturation curves for repeated imbibition and drainage show that the work dissipated in a complete cycle is monotonically increasing with the correlation length ξ of the surface energies. To test whether capillary hysteresis can be linked to specific features of the front morphology, we visualized the distribution of liquids by means of X-ray microtomography. The Minkowski measures volume, surface area, and Euler number are employed to characterize the interfacial shape. Differences of the front morphology during imbibition and drainage match with trends observed for the hysteresis loop opening.

  7. Distribution of Bi Between Slags and Liquid Copper

    NASA Astrophysics Data System (ADS)

    Chen, Chunlin; Wright, Steven

    2016-06-01

    The distribution of Bi between liquid copper and calcium ferrite slag containing 24 wt pct CaO, iron silicate slag with 25 wt pct SiO2, and calcium iron silicate slags was measured at 1573 K (1300 °C) under controlled CO-CO2 atmosphere. The experimental results showed that bismuth distribution is affected by the oxygen partial pressure, and bismuth is likely to exist in slags in the 2+ oxidation state, i.e., as BiO. The distribution ratio between calcium ferrite slag and metal was found to be close to that of iron silicate slag. The Bi distribution ratio was found to decrease with increasing SiO2 and Al2O3 content in slag. Increasing temperature was found to decrease the Bi distribution ratio between slag and metal. Using the measured equilibrium data on Bi content of the metal and slag and composition dependence of the activity of Bi in liquid copper, the activity and hence activity coefficient of BiO in the slag was calculated. The close value of activity coefficient of BiO in both slags at the same oxygen partial pressure indicates that the CaO-BiO and SiO2-BiO interactions are likely to be at the same level, or the FeO x -BiO interaction is the predominant interaction for BiO in the slag. Therefore at a constant FeO x content in the slag, the CaO-BiO and SiO2-BiO interactions doesn't affect γ_{{BiO}} significantly.

  8. Size distributions of gold nanoclusters studied by liquid chromatography

    SciTech Connect

    WILCOXON,JESS P.; MARTIN,JAMES E.; PROVENCIO,PAULA P.

    2000-05-23

    The authors report high pressure liquid chromatography, (HPLC), and transmission electron microscopy, (TEM), studies of the size distributions of nanosize gold clusters dispersed in organic solvents. These metal clusters are synthesized in inverse micelles at room temperature and those investigated range in diameter from 1--10 nm. HPLC is sensitive enough to discern changes in hydrodynamic volume corresponding to only 2 carbon atoms of the passivating agent or metal core size changes of less than 4 {angstrom}. The authors have determined for the first time how the total cluster volume (metal core + passivating organic shell) changes with the size of the passivating agent.

  9. Collision between immiscible drops with large surface tension difference

    NASA Astrophysics Data System (ADS)

    Arienti, Marco; Li, Xiaoyi; Soteriou, Marios; Sussman, Mark

    2009-11-01

    Immiscible drop collision, as occurring in fuel-oxidizer sprays or in the release of certain fire-extinguishing agents, tends to exhibit a much richer behavior with respect to miscible drops collision thanks to the formation of a liquid-liquid interface during impact. For instance, in near-head-on diesel-water drop collisions, ``overlaying'' may occur in which the diesel oil flows from the collision point around the water drop to gather at the opposite location of the drop. To simulate this class of multi-material flows, the combined volume-of-fluid / level set methodology that sharply captures a single liquid-gas interface (Sussman et al, J. of Comp. Phys., 2007) needs to be duplicated for a second, independent interface. In this presentation, we will show that simulation results are not affected by the reconstruction order of the interfaces, as in other surface capturing methods. We will also propose different numerical solutions to treat surface tension in the triple point computational cells, and examine the characteristics of the flow developing at the contact line between the two liquids and air in overlaying head-on collisions.

  10. Detecting energy dependent neutron capture distributions in a liquid scintillator

    NASA Astrophysics Data System (ADS)

    Balmer, Matthew J. I.; Gamage, Kelum A. A.; Taylor, Graeme C.

    2015-03-01

    A novel technique is being developed to estimate the effective dose of a neutron field based on the distribution of neutron captures in a scintillator. Using Monte Carlo techniques, a number of monoenergetic neutron source energies and locations were modelled and their neutron capture response was recorded. Using back propagation Artificial Neural Networks (ANN) the energy and incident direction of the neutron field was predicted from the distribution of neutron captures within a 6Li-loaded liquid scintillator. Using this proposed technique, the effective dose of 252Cf, 241AmBe and 241AmLi neutron fields was estimated to within 30% for four perpendicular angles in the horizontal plane. Initial theoretical investigations show that this technique holds some promise for real-time estimation of the effective dose of a neutron field.

  11. Solute location in a nanoconfined liquid depends on charge distribution

    SciTech Connect

    Harvey, Jacob A.; Thompson, Ward H.

    2015-07-28

    Nanostructured materials that can confine liquids have attracted increasing attention for their diverse properties and potential applications. Yet, significant gaps remain in our fundamental understanding of such nanoconfined liquids. Using replica exchange molecular dynamics simulations of a nanoscale, hydroxyl-terminated silica pore system, we determine how the locations explored by a coumarin 153 (C153) solute in ethanol depend on its charge distribution, which can be changed through a charge transfer electronic excitation. The solute position change is driven by the internal energy, which favors C153 at the pore surface compared to the pore interior, but less so for the more polar, excited-state molecule. This is attributed to more favorable non-specific solvation of the large dipole moment excited-state C153 by ethanol at the expense of hydrogen-bonding with the pore. It is shown that a change in molecule location resulting from shifts in the charge distribution is a general result, though how the solute position changes will depend upon the specific system. This has important implications for interpreting measurements and designing applications of mesoporous materials.

  12. Distributed polarizability models for imidazolium-based ionic liquids.

    PubMed

    Millot, Claude; Chaumont, Alain; Engler, Etienne; Wipff, Georges

    2014-09-25

    Quantum chemical calculations are used to derive distributed polarizability models sufficiently accurate and compact to be used in classical molecular dynamics simulations of imidazolium-based room temperature ionic liquids. Two distributed polarizability models are fitted to reproduce the induction energy of three imidazolium cations (1,3-dimethyl-, 1-ethyl-3-methyl-, and 1-butyl-3-methylimidazolium) and four anions (tetrafluoroborate, hexafluorophosphate, nitrate, and thiocyanate) polarized by a point charge located successively on a grid of surrounding points. The first model includes charge-flow polarizabilities between first-neighbor atoms and isotropic dipolar polarizability on all atoms (except H), while the second model includes anisotropic dipolar polarizabilities on all atoms (except H). For the imidazolium cations, particular attention is given to the transferability of the distributed polarizability sets. The molecular polarizability and its anisotropy rebuilt by the distributed models are found to be in good agreement with the exact ab initio values for the three cations and 23 additional conformers of 1-ethyl-3-methyl-, 1-butyl-3-methyl-, 1-pentyl-3-methyl-, and 1-hexyl-3-methylimidazolium cations. PMID:25133873

  13. 26 CFR 1.332-5 - Distributions in liquidation as affecting minority interests.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 4 2010-04-01 2010-04-01 false Distributions in liquidation as affecting minority interests. 1.332-5 Section 1.332-5 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Corporate Liquidations § 1.332-5 Distributions in liquidation as affecting minority...

  14. Immiscible phase incorporation during directional solidification of hypermonotectics

    NASA Technical Reports Server (NTRS)

    Andrews, J. Barry; Merrick, Roger A.

    1993-01-01

    Solidification processes in immiscible samples were investigated by directly observing the events taking place at the solid-liquid interface during directional solidification. Visualization of these events was made possible through the use of a transparent metal analog system and a temperature gradient stage assembly fitted to an optical microscope. The immiscible transparent analog system utilized was the succinonitrile-glycerol system. This system has been shown to exhibit the same morphological transitions as observed in metallic alloys of monotectic composition. Both monotectic and hypermonotectic composition samples were directionally solidified in order to gain an improved understanding of the manner in which the excess hypermonotectic liquid is incorporated into the solidifying structure. The processing conditions utilized prevented sedimentation of the excess hypermonotectic liquid by directionally solidifying the samples in very thin (13 microns), horizontally oriented cells. High thermal gradient to growth rate ratios (G/R) were used in an effort to prevent constitutional supercooling and the subsequent formation of L(sub 2) droplets in advance of the solidification front during the growth of fibrous composite structures. Results demonstrated that hypermonotectic composites could be produced in samples up to two weight percent off of the monotectic composition by using a G/R ratio greater than or equal to 4.6 x 10(exp 4) C(s)/mm(sup 2) to avoid constitutional supercooling. For hypermonotectic samples processed with G/R ratios below 4.6 x 10(exp 4) C(s)/mm(sup 2), constitutional supercooling occurred and resulted in slight interfacial instability. For these samples, two methods of incorporation of the hypermonotectic liquid were observed and are reported. The correlation between the phase spacing, lambda, and the growth rate, R, was examined and was found to obey a relationship generally associated with a diffusion controlled coupled growth process. For

  15. Interfacial dynamics of two immiscible fluids in spatially periodic porous media: The role of substrate wettability

    NASA Astrophysics Data System (ADS)

    Mondal, Pranab Kumar; DasGupta, Debabrata; Chakraborty, Suman

    2014-07-01

    We delineate the contact line dynamics of two immiscible fluids in a medium having spatially periodic porous structures. The flow is driven by an external applied pressure gradient. We bring out the combined consequences of the solid fraction distribution and the substrate wettability on the resulting dynamics of the contact line, by employing phase-field formalism. We capture the sequence of spatiotemporal events leading to formation of liquid bridges by trapping a small amount of displaced phase fluid between two consecutive porous blocks, as dictated by the combinations of substrate wettability and solid fraction. We also demonstrate the existence of a regime of complete interfacial recovery, depending on the parametric space of the governing parameters under concern. Our results essentially demonstrate the intricate mechanisms by virtue of which the wettabilities of the substrates alter the dynamical evolutions of interfaces and the subsequent shapes and sizes of the adsorbed dispersed phases, bearing far-ranging consequences in several practical applications ranging from oil recovery to groundwater flow.

  16. Blob population dynamics during immiscible two-phase flows in reconstructed porous media

    NASA Astrophysics Data System (ADS)

    Yiotis, A. G.; Talon, L.; Salin, D.

    2013-03-01

    We study the dynamics of nonwetting liquid blobs during immiscible two-phase flows in stochastically reconstructed porous domains predominantly saturated by a wetting fluid. The flow problem is solved explicitly using a Lattice-Boltzmann model that captures both the bulk phase and interfacial dynamics of the process. We show that the nonwetting blobs undergo a continuous life cycle of dynamic breaking up and coalescence producing two populations of blobs, a mobile and a stranded one, that exchange continuously mass between them. The process reaches a “steady state” when the rates of coalescence and breaking up become equal, and the macroscopic flow variables remain practically constant with time. At steady state, mass partitioning between mobile and immobile populations depends strongly on the applied Bond number Bo and the initial nonwetting phase distributions. Three flow regimes are identified: a single-phase flow Darcy-type regime at low Bo numbers, a non-Darcy two-phase flow regime at intermediate values of Bo, where the capillary number scales as Ca∝Bo2, and a Darcy-type two-phase flow regime at higher values of Bo. Our numerical results are found to be in good agreement with recent experimental and theoretical works.

  17. Distributed Health Monitoring System for Reusable Liquid Rocket Engines

    NASA Technical Reports Server (NTRS)

    Lin, C. F.; Figueroa, F.; Politopoulos, T.; Oonk, S.

    2009-01-01

    The ability to correctly detect and identify any possible failure in the systems, subsystems, or sensors within a reusable liquid rocket engine is a major goal at NASA John C. Stennis Space Center (SSC). A health management (HM) system is required to provide an on-ground operation crew with an integrated awareness of the condition of every element of interest by determining anomalies, examining their causes, and making predictive statements. However, the complexity associated with relevant systems, and the large amount of data typically necessary for proper interpretation and analysis, presents difficulties in implementing complete failure detection, identification, and prognostics (FDI&P). As such, this paper presents a Distributed Health Monitoring System for Reusable Liquid Rocket Engines as a solution to these problems through the use of highly intelligent algorithms for real-time FDI&P, and efficient and embedded processing at multiple levels. The end result is the ability to successfully incorporate a comprehensive HM platform despite the complexity of the systems under consideration.

  18. 26 CFR 1.6043-2 - Return of information respecting distributions in liquidation.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 13 2012-04-01 2012-04-01 false Return of information respecting distributions...-2 Return of information respecting distributions in liquidation. (a) Unless the distribution is one... shareholder in liquidation of the whole or any part of its capital stock shall file a return of information...

  19. 26 CFR 1.6043-2 - Return of information respecting distributions in liquidation.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 13 2013-04-01 2013-04-01 false Return of information respecting distributions...-2 Return of information respecting distributions in liquidation. (a) Unless the distribution is one... shareholder in liquidation of the whole or any part of its capital stock shall file a return of information...

  20. 26 CFR 1.6043-2 - Return of information respecting distributions in liquidation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 13 2010-04-01 2010-04-01 false Return of information respecting distributions in liquidation. 1.6043-2 Section 1.6043-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF... information respecting distributions in liquidation. (a) Unless the distribution is one in respect of...

  1. Real-Time Observation on Evolution of Droplets Morphology Affected by Electric Current Pulse in Al-Bi Immiscible Alloy

    NASA Astrophysics Data System (ADS)

    Zhu, Jing; Wang, Tongmin; Cao, Fei; Fu, Hongwang; Fu, Yanan; Xie, Honglan; Xiao, Tiqiao

    2013-05-01

    The evolution of Bi-rich droplets morphology in a solidifying Al-Bi immiscible alloy was directly observed using a synchrotron microradiography technique. The electric current pulse (ECP) was applied to control the solidification process of Al-Bi immiscible alloy. It was found that the electromagnetic pinch force and Marangoni force induced by ECP and temperature gradient, respectively, can significantly affect the distribution of Bi-rich droplets. The electromagnetic pinch force drove the droplets from the center to side; meanwhile, the Marangoni force lifted the droplets from the bottom to the top. As a result, the droplets finally distributed with a manner of "inverted triangle."

  2. Melt immiscibility in Apollo 15 KREEP - Origin of Fe-rich mare basalts

    NASA Technical Reports Server (NTRS)

    Hollister, L. S.; Crawford, M. L.

    1977-01-01

    Silicate liquid immiscibility (SLI) is investigated in terms of chemistry and occurrence in two KREEP-rich Apollo 15 basalts. The two samples have different cooling histories but the same composition. In the first sample, SLI occurred at the time of 58% crystallization. In the second sample, SLI occurred after 20% had crystallized. It is noted that SLI could be initiated as soon as plagioclase (out of a total composition which also included zircon, FeS, SiO2, whitlockite, and ilmenite) alone had crystallized. Attention is given to Fe-rich immiscible melts, and it is suggested that SLI may play an important role in the formation of the source regions of Fe-rich mare basalts. The analytical technique used for the assays was an energy dispersive analysis system with a resolution of 167 eV.

  3. Production of cell-enclosing hollow-core agarose microcapsules via jetting in water-immiscible liquid paraffin and formation of embryoid body-like spherical tissues from mouse ES cells enclosed within these microcapsules.

    PubMed

    Sakai, Shinji; Hashimoto, Ichiro; Kawakami, Koei

    2008-01-01

    We developed agarose microcapsules with a single hollow core templated by alginate microparticles using a jet-technique. We extruded an agarose aqueous solution containing suspended alginate microparticles into a coflowing stream of liquid paraffin and controlled the diameter of the agarose microparticles by changing the flow rate of the liquid paraffin. Subsequent degradation of the inner alginate microparticles using alginate lyase resulted in the hollow-core structure. We successfully obtained agarose microcapsules with 20-50 microm of agarose gel layer thickness and hollow cores ranging in diameter from ca. 50 to 450 microm. Using alginate microparticles of ca. 150 microm in diameter and enclosing feline kidney cells, we were able to create cell-enclosing agarose microcapsules with a hollow core of ca. 150 microm in diameter. The cells in these microcapsules grew much faster than those in alginate microparticles. In addition, we enclosed mouse embryonic stem cells in agarose microcapsules. The embryonic stem cells began to self-aggregate in the core just after encapsulation, and subsequently grew and formed embryoid body-like spherical tissues in the hollow core of the microcapsules. These results show that our novel microcapsule production technique and the resultant microcapsules have potential for tissue engineering, cell therapy and biopharmaceutical applications. PMID:17705234

  4. Measurements of Gas Bubble Size Distributions in Flowing Liquid Mercury

    SciTech Connect

    Wendel, Mark W; Riemer, Bernie; Abdou, Ashraf A

    2012-01-01

    ABSTRACT Pressure waves created in liquid mercury pulsed spallation targets have been shown to induce cavitation damage on the target container. One way to mitigate such damage would be to absorb the pressure pulse energy into a dispersed population of small bubbles, however, measuring such a population in mercury is difficult since it is opaque and the mercury is involved in a turbulent flow. Ultrasonic measurements have been attempted on these types of flows, but the flow noise can interfere with the measurement, and the results are unverifiable and often unrealistic. Recently, a flow loop was built and operated at Oak Ridge National Labarotory to assess the capability of various bubbler designs to deliver an adequate population of bubbles to mitigate cavitation damage. The invented diagnostic technique involves flowing the mercury with entrained gas bubbles in a steady state through a horizontal piping section with a glass-window observation port located on the top. The mercury flow is then suddenly stopped and the bubbles are allowed to settle on the glass due to buoyancy. Using a bright-field illumination and a high-speed camera, the arriving bubbles are detected and counted, and then the images can be processed to determine the bubble populations. After using this technique to collect data on each bubbler, bubble size distributions were built for the purpose of quantifying bubbler performance, allowing the selection of the best bubbler options. This paper presents the novel procedure, photographic technique, sample visual results and some example bubble size distributions. The best bubbler options were subsequently used in proton beam irradiation tests performed at the Los Alamos National Laboratory. The cavitation damage results from the irradiated test plates in contact with the mercury are available for correlation with the bubble populations. The most effective mitigating population can now be designed into prototypical geometries for implementation into

  5. Distribution of rubidium between sodic sanidine and natural silicic liquid

    USGS Publications Warehouse

    Noble, D.C.; Hedge, C.E.

    1970-01-01

    Phenocrysts of sodic sanidine from twelve upper Cenozoic units of silicic ash-flow tuff and lava from the Western United States contain from 0.25 to 0.45 the Rb present in the associated groundmass materials. The ratios of potassium to rubidium in the sanidines are, on the average, about four times greater than those of the groundmass. Separation of phenocrystic sanidine from salic melts provides an efficient method for raising the Rb content and lowering the K/Rb ratio of the melts, although the amount of differentiation probably is limited by continuous reequilibration of the alkalis between crystal and liquid phases through ion exchange. Syenites of cumulate origin will have appreciably lower Rb contents and higher K/Rb ratios than the melts from which they precipitated. Available data on the distribution of Rb between synthetic biotite and K-sanidine demonstrate that the separation of biotite probably will not deplete salic melts in Rb relative to K. ?? 1970 Springer-Verlag.

  6. 25 CFR 16.8 - Summary distribution of small liquid estates.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Summary distribution of small liquid estates. 16.8 Section 16.8 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR PROBATE ESTATES OF INDIANS OF THE FIVE CIVILIZED TRIBES § 16.8 Summary distribution of small liquid estates. Where...

  7. 25 CFR 16.8 - Summary distribution of small liquid estates.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Summary distribution of small liquid estates. 16.8 Section 16.8 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR PROBATE ESTATES OF INDIANS OF THE FIVE CIVILIZED TRIBES § 16.8 Summary distribution of small liquid estates. Where...

  8. 25 CFR 16.8 - Summary distribution of small liquid estates.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Summary distribution of small liquid estates. 16.8 Section 16.8 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR PROBATE ESTATES OF INDIANS OF THE FIVE CIVILIZED TRIBES § 16.8 Summary distribution of small liquid estates. Where...

  9. On Theories for Reacting Immiscible Mixtures

    SciTech Connect

    Drumheller, D.S.

    1998-11-05

    On some small scale each constituent of an immiscible mixture occupies a separate region of space. Given sufficient time and computing power, we could solve the continuum field equations and boundary conditions for this het erogenous system. This usually represents an enormously difficult task that is well beyond today's computational ca- pabilities. Mixture theories approximate this complex heterogeneous formulation with a set of field equations for an equivalent homoge- neous mat erial. In this work, we compare the theory for immiscible mixtures by Drumheller and Bedford with the theory of Passman, Nunziato, and Walsh. We describe the conditions under which these theories reduce to an equivalent formulation, and we also investigate the differences in their microinertial descriptions. Two variables play special roles in both theories. They are t he true material density and the volume fraction. Here we use a kinematical approach based on two new variables-t he true deformation gradient and the distention gradient. We show how the true deformation gra- dient is connected to the true material density and, in the absence of chemical reactions, the volume fraction is the inverse of the deter- minant of the distention gradient. However, when chemical reactions occur, the distention gradient and the volume fraction are not directly connected. We ako present a mixture model for a granuIar expIosive. This model is based upon the work of Baer and Nunziato, but our theory differs from their work in that we Present a three-dimension-al rnodd, `.. ` - - we cast the constitutive postulates in terms of the distention gradient rather than the volume fraction, and we incorporate elastic-plastic effects into the constitutive description of the solid granules.

  10. Electrically induced displacement transport of immiscible oil in saline sediments.

    PubMed

    Pamukcu, Sibel; Shrestha, Reena A; Ribeiro, Alexandra B; Mateus, Eduardo P

    2016-08-01

    Electrically assisted mitigation of coastal sediment oil pollution was simulated in floor-scale laboratory experiments using light crude oil and saline water at approximately 1/10 oil/water (O/W) mass ratio in pore fluid. The mass transport of the immiscible liquid phases was induced under constant direct current density of 2A/m(2), without water flooding. The transient pore water pressures (PWP) and the voltage differences (V) at and in between consecutive ports lined along the test specimen cell were measured over 90days. The oil phase transport occurred towards the anode half of the test specimen where the O/W volume ratio increased by 50% over its initial value within that half-length of the specimen. In contrast, the O/W ratio decreased within the cathode side half of the specimen. During this time, the PWP decreased systematically at the anode side with oil bank accumulation. PWP increased at the cathode side of the specimen, signaling increased concentration of water there as it replaced oil in the pore space. Electrically induced transport of the non-polar, non-conductive oil was accomplished in the opposing direction of flow by displacement in absence of viscous coupling of oil-water phases. PMID:27064863

  11. Finite-Element Analysis of Multiphase Immiscible Flow Through Soils

    NASA Astrophysics Data System (ADS)

    Kuppusamy, T.; Sheng, J.; Parker, J. C.; Lenhard, R. J.

    1987-04-01

    A finite-element model is developed for multiphase flow through soil involving three immiscible fluids: namely, air, water, and a nonaqueous phase liquid (NAPL). A variational method is employed for the finite-element formulation corresponding to the coupled differential equations governing flow in a three-fluid phase porous medium system with constant air phase pressure. Constitutive relationships for fluid conductivities and saturations as functions of fluid pressures, which are derived in a companion paper by J. C. Parker et al. (this issue) and which may be calibrated from two-phase laboratory measurements, are employed in the finite-element program. The solution procedure uses backward time integration with iteration by a modified Picard method to handle the nonlinear properties. Laboratory experiments involving water displacement from soil columns by p cymene (a benzene-derivative hydrocarbon) under constant pressure were simulated by the finite-element program to validate the numerical model and formulation for constitutive properties. Transient water outflow predicted using independently measured saturation-capillary head data agreed with observed outflow data within the limits of precision of the predictions as estimated by a first-order Taylor series approximation considering parameter uncertainty due to experimental reproducability and constitutive model accuracy. Two-dimensional simulations are presented for a hypothetical field case involving introduction of NAPL near the soil surface due to leakage from an underground storage tank. Subsequent transport of NAPL in the variably saturated vadose and groundwater zones is analyzed.

  12. Thermally induced collision of droplets in an immiscible outer fluid

    NASA Astrophysics Data System (ADS)

    Davanlou, Ashkan; Kumar, Ranganathan

    2015-05-01

    Micro-total analysis systems (μTAS) have attracted wide attention and are identified as a promising solution for sample transport, filtration, chemical reactions, separation and detection. Despite their popularity, the selection of an appropriate mechanism for droplet transport and coalescence has always been a challenge. This paper investigates the use of Marangoni flow as a mechanism for levitating and transporting droplets on immiscible liquid films at higher speeds than is possible currently. For the first time, we show that it is possible to realize the natural coalescence of droplets through Marangoni effect without any external stimulation, and deliver the coalesced droplet to a certain destination through the use of surface tension gradients. The effects of shape and size on collision outcome are studied. Regions of coalescence and stretching separation of colliding droplets are delineated based on Weber number and impact number. In addition, the effect of viscosity on post collision regimes is studied. The findings in this fundamental study can be beneficial to many applications such as welding, drug delivery and microfluidics devices in controlling small droplets and targeting them to various locations.

  13. Particle Swarm Transport through Immiscible Fluid Layers in a Fracture

    NASA Astrophysics Data System (ADS)

    Teasdale, N. D.; Boomsma, E.; Pyrak-Nolte, L. J.

    2011-12-01

    Immiscible fluids occur either naturally (e.g. oil & water) or from anthropogenic processes (e.g. liquid CO2 & water) in the subsurface and complicate the transport of natural or engineered micro- or nano-scale particles. In this study, we examined the effect of immiscible fluids on the formation and evolution of particle swarms in a fracture. A particle swarm is a collection of colloidal-size particles in a dilute suspension that exhibits cohesive behavior. Swarms fall under gravity with a velocity that is greater than the settling velocity of a single particle. Thus a particle swarm of colloidal contaminants can potentially travel farther and faster in a fracture than expected for a dispersion or emulsion of colloidal particles. We investigated the formation, evolution, and break-up of colloidal swarms under gravity in a uniform aperture fracture as hydrophobic/hydrophyllic particle swarms move across an oil-water interface. A uniform aperture fracture was fabricated from two transparent acrylic rectangular prisms (100 mm x 50 mm x 100 mm) that are separated by 1, 2.5, 5, 10 or 50 mm. The fracture was placed, vertically, inside a glass tank containing a layer of pure silicone oil (polydimethylsiloxane) on distilled water. Along the length of the fracture, 30 mm was filled with oil and 70 mm with water. Experiments were conducted using silicone oils with viscosities of 5, 10, 100, or 1000 cSt. Particle swarms (5 μl) were comprised of a 1% concentration (by mass) of 25 micron glass beads (hydrophilic) suspended in a water drop, or a 1% concentration (by mass) of 3 micron polystyrene fluorescent beads (hydrophobic) suspended in a water drop. The swarm behavior was imaged using an optical fluorescent imaging system composed of a CCD camera and by green (525 nm) LED arrays for illumination. Swarms were spherical and remained coherent as they fell through the oil because of the immiscibility of oil and water. However, as a swarm approached the oil-water interface, it

  14. REDISTRIBUTOR FOR LIQUID-LIQUID EXTRACTION COLUMNS

    DOEpatents

    Bradley, J.G.

    1957-10-29

    An improved baffle plate construction to intimately mix immiscible liquid solvents for solvent extraction processes in a liquid-liquid pulse column is described. To prevent the light and heavy liquids from forming separate continuous homogeneous vertical channels through sections of the column, a baffle having radially placed rectangular louvers with deflection plates opening upon alternate sides of the baffle is placed in the column, normal to the axis. This improvement substantially completely reduces strippiig losses due to poor mixing.

  15. Effect of Organoclays on Immiscible Polymer Blends

    NASA Astrophysics Data System (ADS)

    Ha, Mai; Krishnamoorti, Ramanan

    2011-03-01

    The effect of adding organoclays on the phase behavior, rheological properties and bulk mechanical properties of immiscible polymer blends of polystyrene (PS) and poly(methyl methacrylate) (PMMA) is investigated. Traditional organoclays, prepared using alkyl ammonium chains, display a preference to segregate to the PS phase for high PS volume fraction blends where the PS forms the continuous matrix. On the other hand, for blends with low PS volume fractions, the organoclay segregates to the interface between the PS and PMMA domains and leads to a decrease in the domain size that does not change much with organoclay concentration variations from 0.1 to 2 wt %. Linear dynamic rheological data of these samples show significant increase in the low-frequency modulus of the blends with added organoclay. A thermodynamic model for estimating the interfacial modulus is proposed and the results agree well with the interfacial modulus calculated by Palierne's emulsion model. The toughness of the blends increases at low concentrations of added organoclays with the optimal improvements observed for less than 0.5 wt % added organoclay.

  16. Chemical amplification based on fluid partitioning in an immiscible liquid

    DOEpatents

    Anderson, Brian L.; Colston, Bill W.; Elkin, Christopher J.

    2010-09-28

    A system for nucleic acid amplification of a sample comprises partitioning the sample into partitioned sections and performing PCR on the partitioned sections of the sample. Another embodiment of the invention provides a system for nucleic acid amplification and detection of a sample comprising partitioning the sample into partitioned sections, performing PCR on the partitioned sections of the sample, and detecting and analyzing the partitioned sections of the sample.

  17. Liquid distribution and cohesion in wet granular assemblies beyond the capillary bridge regime

    NASA Astrophysics Data System (ADS)

    Scheel, M.; Seemann, R.; Brinkmann, M.; Di Michiel, M.; Sheppard, A.; Herminghaus, S.

    2008-12-01

    Dry sand turns into a stiff and moldable material as soon as it is mixed with some liquid. This is a direct consequence of the internal liquid-air interfaces spanning between the grains which causes capillary cohesion by virtue of the surface tension of the liquid. As a model for wet granulates we investigated random packings of submillimeter spherical beads mixed with water. Measurements of the tensile strength and the fluidization threshold demonstrate that the mechanical stiffness is rather insensitive to the liquid content over a wide range. Only for a high liquid content, when more than half of the available pore space is filled with liquid, does the capillary cohesion weaken. In order to understand the interplay between the mechanical properties and the liquid content, we investigated the liquid distribution in random packings of glass spheres by means of x-ray microtomography. The three-dimensional images reveal that the liquid forms a network of capillary bridges fused at local triangular bead configurations. The spontaneous organization of the liquid into these ramified structures, which exhibit a large liquid-air interface, is responsible for the constancy of the cohesive forces in a wide range of liquid contents beyond the onset of capillary bridge coalescence.

  18. Sol-gel auto-combustion synthesis of totally immiscible NiAg alloy

    SciTech Connect

    Jiang, Yuwen; Yang, Shaoguang; Hua, Zhenghe; Gong, Jiangfeng; Zhao, Xiaoning

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer Chemically synthesized immiscible NiAg alloy nanoparticles without protecting matrix. Black-Right-Pointing-Pointer A chemical method providing both a nonequilibrium thermal process and a good mixing of precursors. Black-Right-Pointing-Pointer Observation of extinction planes in NiAg alloy. -- Abstract: Immiscible crystalline NiAg alloy was successfully synthesized by the newly developed sol-gel auto-combustion method. The structure and composition were examined by X-ray diffraction (XRD) and high resolution transmission electron microscope (HRTEM). All evidence supports that homogeneous NiAg alloy with FCC structure was synthesized. The differential thermal analysis and thermogravimetry (DTA-TG) measurement shows that the alloy has a good thermal stability until 315 Degree-Sign C. Unusually some extinction planes are observed in the XRD pattern and HRTEM images. The random distribution of atoms and the large difference between Ni and Ag atom form factors should be regarded as the main reasons for the observation of the extinction planes. The quenching like nonequilibrium thermal process in the combustion is taken as the key factor in the synthesis of immiscible alloy. And the addition of ethylene glycol in the precursors is found to benefit the formation of NiAg alloy.

  19. Capillary pinning of immiscible gravity currents in porous media

    NASA Astrophysics Data System (ADS)

    Zhao, B.; MacMinn, C. W.; Huppert, H. E.; Juanes, R.

    2013-12-01

    Gravity currents in porous media have attracted interest recently in the context of geological carbon dioxide (CO2) storage, where supercritical CO2 is captured from the flue gas of power plants and injected underground into deep saline aquifers. Capillarity can be important in the spreading and migration of the buoyant CO2 after injection because the typical pore size is very small (~10-100 microns), but the impact of capillarity on these flows is not well understood. Here, we study the impact of capillarity on the buoyant spreading of a finite gravity current of non-wetting fluid into a dense, wetting fluid in a vertically confined, horizontal aquifer. We show via simple, table-top experiments using glass bead packs that capillary pressure hysteresis pins a portion of the fluid-fluid interface. The horizontal extent of the pinned portion of the interface grows over time and this is responsible for ultimately stopping the spreading of the buoyant current after a finite distance. In addition, capillarity blunts the leading edge of the buoyant current. We demonstrate through micromodel experiments that the characteristic height of the nose of the current is controlled by the pore throat size distribution and the balance between capillarity and gravity. We develop a theoretical model that captures the evolution of immiscible gravity currents and predicts the maximum migration distance. Our work suggests that capillary pinning and capillary blunting exert an important control on finite-release gravity currents in the context of CO2 sequestration in deep saline aquifers. Gravity driven flow of a buoyant, nonwetting fluid (air) over a dense, wetting fluid (propylene glycol). Starting with a vertical interface between the fluids, the flow first undergoes a lock-exchange process. The process models a finite release problem after the dense fluid hits the left boundary. In contrast to finite release of a miscible current that spreads indefinitely, spreading of an immiscible

  20. Atom Pair Distribution Functions of Liquid Water at 25circC from Neutron Diffraction

    NASA Astrophysics Data System (ADS)

    Narten, A. H.; Thiessen, W. E.; Blum, L.

    1982-09-01

    The structure of liquid water is described by three atom pair distribution functions gOO(r), gOH(r), and gHH(r). These functions have now been derived from neutron diffraction data on four mixtures of light and heavy water. They will provide a crucial and sensitive test for proposed models of liquid water.

  1. DOES VARIABLE DISTRIBUTION AFFECT LIQUID P-USE EFFICIENCY?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Experiments show that banding of liquid P is more effective than broadcast. The effectiveness of banded P has been shown to be increasingly superior, compared to broadcasting P, when P rate increases to the optimum level. The greater the speed of application, the smaller becomes the distance between...

  2. Manifold to uniformly distribute a solid-liquid slurry

    DOEpatents

    Kern, Kenneth C.

    1983-01-01

    This invention features a manifold that divides a stream of coal particles and liquid into several smaller streams maintaining equal or nearly equal mass compositions. The manifold consists of a horizontal, variable area header having sharp-edged, right-angled take-offs which are oriented on the bottom of the header.

  3. LIGHT NONAQUEOUS PHASE LIQUIDS

    EPA Science Inventory

    Nonaqueous phase liquids (NAPLS) are hydrocarbons that exist as a separate, immiscible phase when in contact with water and/or air. ifferences in the physical and chemical properties of water and NAPL result in the formation of a physical interface between the liquids which preve...

  4. A numerical study of liquid film distribution in wet natural gas pipelines

    NASA Astrophysics Data System (ADS)

    Gao, X. Q.; Zhao, Y. L.; Xu, W. W.; Guan, X. R.; Wang, J. J.; Jin, Y. H.

    2016-05-01

    The software of FLUENT was used to simulate the gas-liquid turbulent flow in wet natural gas pipeline of the Puguang gas field. The RNG k- ɛ model was used to simulate the turbulent flow, the Mixture model was used to simulate gas-liquid mixed phase, and the Eulerian wall film model was used to simulate the formation and development of liquid film. The gas phase flow field characteristics, the distribution of the axial and circumferential film thickness, and the droplet distribution in the pipeline were studied when the gas Reynolds number is 7.72 × 106(10.8m/s). The results can be concluded as followed: Liquid film distributes unevenly along the circumferential direction and mostly distributes under the pipeline wall because of gravity. The impact of the dean vortex and centrifugal force in the straight section can also influence the liquid film distribution. The wall shear stress distributions in horizontal straight pipeline is concerned with liquid membrane volatility, and consistent with the film volatility period, the wall shear stress reached the maximum value in a certain position of wave front. The influence of the wall shear stress on the film fluctuation in inclined pipeline is weakened by gravity and other factors.

  5. Distribution of solute at solid-liquid interface during solidification of melt

    NASA Astrophysics Data System (ADS)

    Fukui, Keisuke; Maeda, Kouji

    1998-11-01

    A model for predicting a distribution coefficient (ki) of solute at the solid-liquid (S-L) interface, when the solid layer is growing, is proposed. The interfacial distribution coefficient is expressed as a function of two gradients of the liquid concentration and equilibrium concentration at the S-L interface. The model is applied to the solidification of a simple eutectic binary liquid of lauric acid and myristic acid in an enclosed rectangular box in which a vertical wall is cooled. The impurity-concentration profile in solid is predicted from the direct numerical computations.

  6. Quantitative measurement of binary liquid distributions using multiple-tracer x-ray fluorescence and radiography

    SciTech Connect

    Halls, Benjamin R.; Meyer, Terrence R.; Kastengren, Alan L.

    2015-01-01

    The complex geometry and large index-of-refraction gradients that occur near the point of impingement of binary liquid jets present a challenging environment for optical interrogation. A simultaneous quadruple-tracer x-ray fluorescence and line-of-sight radiography technique is proposed as a means of distinguishing and quantifying individual liquid component distributions prior to, during, and after jet impact. Two different pairs of fluorescence tracers are seeded into each liquid stream to maximize their attenuation ratio for reabsorption correction and differentiation of the two fluids during mixing. This approach for instantaneous correction of x-ray fluorescence reabsorption is compared with a more time-intensive approach of using stereographic reconstruction of x-ray attenuation along multiple lines of sight. The proposed methodology addresses the need for a quantitative measurement technique capable of interrogating optically complex, near-field liquid distributions in many mixing systems of practical interest involving two or more liquid streams.

  7. Investigation of immiscible systems and potential applications

    NASA Technical Reports Server (NTRS)

    Markworth, A. J.; Oldfield, W.; Duga, J.; Gelles, S. H.

    1975-01-01

    The droplet coalescence kinetics at 0 g and 1 g were considered for two systems which contained liquid droplets in a host liquid. One of these (Al-In) typified a system containing a liquid phase miscibility gap and the order (oil-water) a mixture of two essentially insoluble liquids. A number of coalescence mechanisms potentially prominent at low g in this system were analyzed and explanations are presented for the observed unusual stability of the emulsion. Ground base experiments were conducted on the coalescence of In droplets in and Al-In alloy during cooling through the miscibility gap at different cooling rates. These were in qualitative agreement with the computer simulation. Potential applications for systems with liquid phase miscibility gaps were explored. Possibilities included superconductors, electrical contact materials, superplastic materials, catalysts, magnetic materials, and others. The role of space processing in their production was also analyzed.

  8. Effect of wettability on adverse mobility immiscible floods

    SciTech Connect

    Vives, M.T.; Chang, Y.C.; Mohanty, K.K.

    1995-12-31

    Many immiscible displacements in reservoirs occur at adverse mobility. Effect of wettability on these displacements is not well understood and often ignored in reservoir simulation. Recent macroscopic theories of viscous fingering treat adverse immiscible flows similar to miscible flows, the mixing in the fingered region being controlled by a Todd-Longstaff-type functional form. The wettability of the medium is taken into account only through the use of appropriate relative permeabilities. The goal of this paper is to understand the macroscopic bypassing in adverse mobility immiscible floods. Immiscible displacements are conducted in a quarter 5-spot model in both drainage and imbibition modes at similar effective mobility ratios and viscous-to-gravity numbers. The level of bypassing and gravity override is visualized and measured. Tertiary water-alternating-gas (WAG) displacements are also conducted at various WAG ratios and viscosity ratios. Fractional flow analysis and numerical simulation are used to understand these displacements. Experiments show that macroscopic viscous fingering is present in adverse viscosity immiscible displacements where no saturation shock is expected from 1-D fractional flow theory. Bypassing due to both fingering and gravity override is higher in the drainage mode than in the imbibition mode, with other key parameters being the same. Optimum WAG ratio in water-wet rock is a function of oil/solvent viscosity ratio. The macroscopic flow theory needs to include capillarity and viscous fingering to match these experimental findings.

  9. Peralkaline nephelinite-natrocarbonatite immiscibility and carbonatite assimilation at Oldoinyo Lengai, Tanzania

    NASA Astrophysics Data System (ADS)

    Mitchell, Roger H.

    2009-11-01

    This study presents petrographic and compositional data for coexisting peralkaline silicate glass and quenched natrocarbonatite melt in nepheline phenocrysts from the 24 September 2007 and July 2008 eruptions of the natrocarbonatite volcano Oldoinyo Lengai (Tanzania). Data are also given for peralkaline residual glass in combeite nephelinite ash clasts occurring in the March-April 2006 large volume natrocarbonatite flow. These data are considered to demonstrate the occurrence of liquid immiscibility between strongly peralkaline Fe-rich nephelinite melt and natrocarbonatite at Oldoinyo Lengai. Compositional data for coexisting silicate-carbonate pairs in conjunction with previous experimental studies suggest that the size of the field of liquid immiscibility for carbonated nephelinitic magmas is a function of their peralkalinity. It is shown that peralkaline combeite wollastonite nephelinite was present at Oldoinyo Lengai prior to, and during, the 24 September 2007 ash eruption. It is postulated that the driving force for this major eruption was assimilation and decomposition of previously emplaced solid natrocarbonatite. Assimilation resulted in the formation of the unusual hybrid nepheline-andradite-melilite-combeite-phosphate magma represented by the 24 September 2007 ash.

  10. Distributed hydrophone array based on liquid crystal cell

    NASA Astrophysics Data System (ADS)

    Brodzeli, Zourab; Ladouceur, Francois; Silvestri, Leonardo; Michie, Andrew; Chigrinov, Vladimir; Guo, Grace Qi; Pozhidaev, Eugene P.; Kiselev, Alexei D.

    2012-02-01

    We describe a fibre optic hydrophone array system that could be used for underwater acoustic surveillance applications e.g. military, counter terrorist and customs authorities in protecting ports and harbors, offshore production facilities or coastal approaches as well as various marine applications. In this paper we propose a new approach to underwater sonar systems using voltage-controlled Liquid Crystals (LC) and simple multiplexing method. The proposed method permits measurements of sound under water at multiple points along an optical fibre using low cost components (LC cells), standard single mode fibre, without complex interferometric measurement techniques, electronics or demodulation software.

  11. Liquid electrode

    DOEpatents

    Ekechukwu, Amy A.

    1994-01-01

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

  12. PHYSICS OF IMMISCIBLE FLOW IN POROUS MEDIA

    EPA Science Inventory

    Conceptual formulation, numerical implementation and experimental validation of a model for the movement of organic chemicals which are introduced into soils as nonaqueous phase liquids via surface spills or leakage from subsurface containment facilities were addressed. Relations...

  13. Liquid metal filtration and distribution using fiberglass fabric

    SciTech Connect

    Brochu, C.; Dault, R.; Tremblay, S.P.

    1996-10-01

    In the last decade, the aluminum industry has mainly focused on improving metal quality by working on furnaces and casting practices and especially on in-line treatment units. However, fiberglass fabric is widely used throughout the industry. It is specially used at the last step before the solidification process when molten metal is transferred from the trough to the ingot mold. In this regard, little effort has been reported on better understanding or using fiberglass fabric in molten aluminum filtration and distribution applications. This paper will review the fiberglass fabric options. The different fiberglass fabric coatings and finishes will be described as well as their properties and characteristics with regard to molten aluminum. Fiberglass fabric used in filtration applications will be defined as a function of selected parameters such as opening, finish, throughput, etc. Finally, metal distribution will be discussed. A better understanding of fiberglass fabric finishes and bag configuration will improve metal distribution and ultimately, the final ingot quality.

  14. Water and hydrogen are immiscible in Earth's mantle.

    PubMed

    Bali, Enikő; Audétat, Andreas; Keppler, Hans

    2013-03-14

    In the deep, chemically reducing parts of Earth's mantle, hydrous fluids contain significant amounts of molecular hydrogen (H2). Thermodynamic models of fluids in Earth's mantle so far have always assumed that molecular hydrogen and water are completely miscible. Here we show experimental evidence that water and hydrogen can coexist as two separate, immiscible phases. Immiscibility between water and hydrogen may be the cause of the formation of enigmatic, ultra-reducing domains in the mantle that contain moissanite (SiC) and other phases indicative of extremely reducing conditions. Moreover, the immiscibility between water and hydrogen may provide a mechanism for the rapid oxidation of Earth's upper mantle immediately following core formation. PMID:23486061

  15. A new insight into interfaces of immiscible binary polymer blends from the free volume approach

    NASA Astrophysics Data System (ADS)

    Ramya, P.; Meghala, D.; Pasang, T.; Raj, J. M.; Chandrashekara, M. N.; Ranganathaiah, C.

    2012-06-01

    The interface width in an immiscible (PVC/PS) polymer blend is determined using hydrodynamic interaction parameter (α) derived from free volume data measured using Positron lifetime spectrometer. CONTIN program has been employed to get the free volume hole size distribution. A new definition of interface width is presented, which originates from the Kirkwood-Riseman theory and friction coefficient as per Stokes equation. Friction at the interface of a binary blend decides how close the surfaces come or stay farther resulting in narrow or broad interface width respectively.

  16. Liquid crystal nanoparticle formulation as an oral drug delivery system for liver-specific distribution

    PubMed Central

    Lee, Dong Ryeol; Park, Ji Su; Bae, Il Hak; Lee, Yan; Kim, B Moon

    2016-01-01

    Liquid crystal nanoparticles have been utilized as an efficient tool for drug delivery with enhanced bioavailability, drug stability, and targeted drug delivery. However, the high energy requirements and the high cost of the liquid crystal preparation have been obstacles to their widespread use in the pharmaceutical industry. In this study, we prepared liquid crystal nanoparticles using a phase-inversion temperature method, which is a uniquely low energy process. Particles prepared with the above method were estimated to be ~100 nm in size and exhibited a lamellar liquid crystal structure with orthorhombic lateral packing. Pharmacokinetic and tissue distribution studies of a hydrophobic peptide-based drug candidate formulated with the liquid crystal nanoparticles showed a five-fold enhancement of bioavailability, sustained release, and liver-specific drug delivery compared to a host–guest complex formulation. PMID:27042053

  17. Self-Transport of Condensed Liquid in Micro Cooling Device Using Distributed Meniscus Pumping.

    PubMed

    So, Hongyun; Pisano, Albert P

    2015-06-16

    This paper reports a reliable passive micro pump system combining the physical properties of a tapered microchannel and sharp microstructures. This tailored microchannel with triple-spike microstructures was created to transport condensed liquid into the reservoir chamber in a micro cooling device and in the case of chip off-mode prepare the next cooling cycle before chip on-mode, allowing the reliable and continuous circulation of coolant without liquid being trapped in the vapor channel causing dryout limitation. At the tapered channel end, the pinned liquid meniscus was distributed by a middle spike and then continued to overflow into the condenser chamber due to extended capillary action. PMID:26010771

  18. Liquidity, Technological Opportunities, and the Stage Distribution of Venture Capital Investments

    PubMed Central

    Lahr, Henry; Mina, Andrea

    2014-01-01

    This paper explores the determinants of the stage distribution of European venture capital investments from 1990 to 2011. Consistent with liquidity risk theory, we find that the likelihood of investing in earlier stages increases relative to all private equity investments during liquidity crisis years. While liquidity is the main driver of acquisition investments and, to some extent, of expansion financings, technological opportunities are overall the main driver of early and late stage venture capital investments. In contrast to the dotcom crash, the recent financial crisis negatively affected the relative likelihood of expansion investments, but not of early and late stage investments. PMID:26166906

  19. Experimental Investigation on Liquid Metal Flow Distribution in Insulating Manifold under Uniform Magnetic Field

    NASA Astrophysics Data System (ADS)

    Miura, Masato; Ueki, Yoshitaka; Yokomine, Takehiko; Kunugi, Tomoaki

    2012-11-01

    Magnetohydrodynamics (MHD) problem which is caused by interaction between electrical conducting fluid flow and the magnetic field is one of the biggest problem in the liquid metal blanket of the fusion reactor. In the liquid metal blanket concept, it is necessary to distribute liquid metal flows uniformly in the manifold because imbalance of flow rates should affect the heat transfer performance directly, which leads to safety problem. While the manifold is insulated electrically as well as the flow duct, the 3D-MHD effect on the flowing liquid metal in the manifold is more apparent than that in straight duct. With reference to the flow distribution in this concept, the liquid metal flow in the electrical insulating manifold under the uniform transverse magnetic field is investigated experimentally. In this study, GaInSn is selected as working fluid. The experimental system includes the electrical magnet and the manifold test section which is made of acrylic resin for perfectly electrical insulation. The liquid metal flows in a non-symmetric 180°-turn with manifold, which consists of one upward channel and two downward channels. The flow rates in each channel are measured by electromagnetic flow meters for several combinations Reynolds number and Hartman number. The effects of magnetic field on the uniformity of flow distribution are cleared.

  20. Liquid flow and distribution in unsaturated porous media

    NASA Technical Reports Server (NTRS)

    Alexander, J. Iwan

    2004-01-01

    Flow and transport in permeable or porous media and microchannels occurs in a variety of situations in micro- and reduced-gravity environments, many of them associated with environmental control and life support systems. While the role of gravity is limited, due to the typically small size scales associated permeable media, gravity, at the very least, affects the overall disposition of fluid in a macroscopic system. This presentation will discuss examples where the absence of gravity affects flow and phase distribution in selected examples of unsaturated flow and transport of heat and mass in porous media and microchannels that are pertinent to spacecraft systems.

  1. LIQUID CYCLONE CONTACTOR

    DOEpatents

    Whatley, M.E.; Woods, W.M.

    1962-09-01

    This invention relates to liquid-liquid extraction systems. The invention, an improved hydroclone system, comprises a series of serially connected, axially aligned hydroclones, each of which is provided with an axially aligned overflow chamber. The chambers are so arranged that rotational motion of a fluid being passed through the system is not lost in passing from chamber to chamber; consequently, this system is highly efficient in contacting and separating two immiscible liquids. (AEC)

  2. Capillary pinning and blunting of immiscible gravity currents in porous media

    NASA Astrophysics Data System (ADS)

    Zhao, Benzhong; MacMinn, Christopher W.; Huppert, Herbert E.; Juanes, Ruben

    2014-09-01

    Gravity-driven flows in the subsurface have attracted recent interest in the context of geological carbon dioxide (CO2) storage, where supercritical CO2 is captured from the flue gas of power plants and injected underground into deep saline aquifers. After injection, the CO2 will spread and migrate as a buoyant gravity current relative to the denser, ambient brine. Although the CO2 and the brine are immiscible, the impact of capillarity on CO2 spreading and migration is poorly understood. We previously studied the early time evolution of an immiscible gravity current, showing that capillary pressure hysteresis pins a portion of the macroscopic fluid-fluid interface and that this can eventually stop the flow. Here we study the full lifetime of such a gravity current. Using tabletop experiments in packings of glass beads, we show that the horizontal extent of the pinned region grows with time and that this is ultimately responsible for limiting the migration of the current to a finite distance. We also find that capillarity blunts the leading edge of the current, which contributes to further limiting the migration distance. Using experiments in etched micromodels, we show that the thickness of the blunted nose is controlled by the distribution of pore-throat sizes and the strength of capillarity relative to buoyancy. We develop a theoretical model that captures the evolution of immiscible gravity currents and predicts the maximum migration distance. By applying this model to representative aquifers, we show that capillary pinning and blunting can exert an important control on gravity currents in the context of geological CO2 storage.

  3. Ionic Liquids for Utilization of Waste Heat from Distributed Power Generation Systems

    SciTech Connect

    Joan F. Brennecke; Mihir Sen; Edward J. Maginn; Samuel Paolucci; Mark A. Stadtherr; Peter T. Disser; Mike Zdyb

    2009-01-11

    The objective of this research project was the development of ionic liquids to capture and utilize waste heat from distributed power generation systems. Ionic Liquids (ILs) are organic salts that are liquid at room temperature and they have the potential to make fundamental and far-reaching changes in the way we use energy. In particular, the focus of this project was fundamental research on the potential use of IL/CO2 mixtures in absorption-refrigeration systems. Such systems can provide cooling by utilizing waste heat from various sources, including distributed power generation. The basic objectives of the research were to design and synthesize ILs appropriate for the task, to measure and model thermophysical properties and phase behavior of ILs and IL/CO2 mixtures, and to model the performance of IL/CO2 absorption-refrigeration systems.

  4. Burnout and distribution of liquid between the flow core and wall films in narrow slot channels

    NASA Astrophysics Data System (ADS)

    Boltenko, E. A.; Shpakovskii, A. A.

    2010-03-01

    Previous works on studying distribution of liquid between the flow core and wall films in narrow slot channels are briefly reviewed. Interrelation between mass transfer processes and burnout is shown. A procedure for calculating burnout on convex and concave heat-transfer surfaces in narrow slot channels is presented.

  5. Cooling tower with concrete support structure, fiberglass panels, and a fan supported by the liquid distribution system

    SciTech Connect

    Bardo, C. J.; Clark Jr., J. L.; Dylewski, A. J.; Seawell, J. Q.

    1985-09-24

    A liquid cooling tower includes precast concrete support legs and cross beams and fiberglass reinforced polyester resin side and top panels. A liquid distribution system is supplied with liquid by a vertically extending main pipe, and a fan and fan motor are supported by the main pipe.

  6. Study of miscible and immiscible flows in a microchannel using magnetic resonance imaging.

    PubMed

    Akpa, Belinda S; Matthews, Sinéad M; Sederman, Andrew J; Yunus, Kamran; Fisher, Adrian C; Johns, Michael L; Gladden, Lynn F

    2007-08-15

    Magnetic resonance imaging (MRI) is a noninvasive technique that can be used to visualize mixing processes in optically opaque systems in up to three dimensions. Here, MRI has been used for the first time to obtain both cross-sectional velocity and concentration maps of flow through an optically opaque Y-shaped microfluidic sensor. Images of 23 micromx23 microm resolution were obtained for a channel of rectangular cross section (250 micromx500 microm) fed by two square inlets (250 micromx250 microm). Both miscible and immiscible liquid systems have been studied. These include a system in which the coupling of flow and mass transfer has been observed, as the diffusion of the analyte perturbs local hydrodynamics. MRI has been shown to be a versatile tool for the study of mixing processes in a microfluidic system via the multidimensional spatial resolution of flow and mass transfer. PMID:17630718

  7. Dimple coalescence and liquid droplets distributions during phase separation in a pure fluid under microgravity.

    PubMed

    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

  8. Influence of Viscous and Capillary Forces on Immiscible Fluid Displacement: Pore-Scale Experimental Study in a Water-Wet Micromodel Demonstrating Viscous and Capillary Fingering

    SciTech Connect

    Zhang, Changyong; Oostrom, Martinus; Wietsma, Thomas W.; Grate, Jay W.; Warner, Marvin G.

    2011-08-18

    Unstable immiscible fluid displacement in porous media affects geological carbon sequestration, enhanced oil recovery, and groundwater contamination by nonaqueous phase liquids. Characterization of immiscible displacement processes at the pore-scale is important to better understand macroscopic processes at the continuum-scale. A series of displacement experiments was conducted to investigate the impacts of viscous and capillary forces on displacement stability and fluid saturation distributions in a homogeneous water-wet pore network micromodel with precisely-microfabricated pore structures. Displacements were studied using seven wetting-nonwetting fluid pairs with viscosity ratios M (viscosity of the advancing nonwetting fluid divided by the viscosity of the displaced wetting fluid) ranging four orders of magnitude from logM = -1.95 to 1.88. The micromodel was initially saturated with either polyethylene glycol 200 (PEG200) or water as a wetting fluid, which was then displaced by a nonwetting alkane fluid under different flow rates. Capillary numbers (Ca) ranged over four orders of magnitude for the reported experiments, from logCa = -5.88 to -1.02. Fluorescent microscopy was used to visualize displacement and measure nonwetting fluid saturation distributions. These experiments extend the classical work by Lenormand et al. by using water-wet micromodels, high-precision fabrication, and enhanced image analysis of the saturation distributions. In the micromodel experiments initially saturated with PEG200, a viscous wetting fluid, unstable displacement occurred by viscous fingering over the whole range of imposed capillary numbers. For the experiments initially saturated with water, unstable displacement occurred by capillary fingering at low capillary numbers. When the viscous forces were increased by increasing the injection rate, crossover into stable displacement was observed for the fluid pairs with M > 0. For unstable displacement experiments applying the same

  9. Interfacial tension measurement of immiscible liq uids using a capillary tube

    NASA Technical Reports Server (NTRS)

    Rashidnia, N.; Balasubramaniam, R.; Delsignore, D.

    1992-01-01

    The interfacial tension of immiscible liquids is an important thermophysical property that is useful in the behavior of liquids both in microgravity (Martinez et al. (1987) and Karri and Mathur (1988)) and in enhanced oil recovery processes under normal gravity (Slattery (1974)). Many techniques are available for its measurement, such as the ring method, drop weight method, spinning drop method, and capillary height method (Adamson (1960) and Miller and Neogi (1985)). Karri and Mathur mention that many of the techniques use equations that contain a density difference term and are inappropriate for equal density liquids. They reported a new method that is suitable for both equal and unequal density liquids. In their method, a capillary tube forms one of the legs of a U-tube. The interfacial tension is related to the heights of the liquids in the cups of the U-tube above the interface in the capillary. Our interest in this area arose from a need to measure small interfacial tension (around 1 mN/m) for a vegetable oil/silicon oil system that was used in a thermocapillary drop migration experiment (Rashidnia and Balasubramaniam (1991)). In our attempts to duplicate the method proposed by Karri and Mathur, we found it quite difficult to anchor the interface inside the capillary tube; small differences of the liquid heights in the cups drove the interface out of the capillary. We present an alternative method using a capillary tube to measure the interfacial tensions of liquids of equal or unequal density. The method is based on the combined capillary rises of both liquids in the tube.

  10. Multiple (immiscible) melt phases of mafic composition in Chicxulub impact ejecta from northeastern Mexico: New constraints on target lithologies

    NASA Astrophysics Data System (ADS)

    Schulte, P.; Stinnesbeck, W.; Kontny, A.; Stüben, D.; Kramar, U.; Harting, M.

    2002-12-01

    Proximal ejecta deposits in sections from NE Mexico (Rancho Nuevo, La Sierrita, El Peñon, El Mimbral) have been investigated by backscattered electron imaging, wave-length dispersive electron microprobe analyses, and cathodoluminiscence, in order to characterize target lithologies, and ejecta mixing, fractionation, and distribution mechanisms. Additional investigations included magnetic properties (Kontny et al, this meeting) and trace element analyses (Harting et al, this meeting). Petrological features of these ejecta deposits are extraordinarily well preserved. They consist of mm-cm sized vesiculated spherical to drop-shaped spherules and angular to filamentous (ejecta-) fragments, as well as carbonate clasts, marl clasts, and rare benthic foraminifera floating in a carbonaceous matrix. Occasionally, spherules and fragments show welding-amalgamation features and enclose other components, thus resulting in a foam-like texture. An origin from the Chicxulub impact is suggested by geographical proximity and morphologically similarity to spherules found in other K-T sites in North to Central America and the Atlantic. The far distribution of such coarse-grained, foamy, and fragile ejecta-clasts as well as welding features suggest ignimbrite-like transport mechanisms or nearby secondary impacts. Several silicic ejecta phases have been observed that occur as distinct phases, even within one ejecta particle with textures indicative of liquid immiscibility: (1) Fe- (25-35 wt%), Mg- (10-15 wt%) rich phases with <25 wt% SiO2, altered to chlorite, (2) K- (5-8 wt.%) and Al- (25-30 wt%) rich hydrated glass with 45-50 wt% SiO2, and (3) rare SiO2- (>60 wt%) rich andesitic glasses. In addition to these silicic phases, abundant carbonate characterizes all studied ejecta deposits. It occurs within spherules and fragments and as clasts and globules, and shows textures indicative of either liquid immiscibility and/or quenching (`feathery calcite'). Quenched carbonates are enriched

  11. Streaming potential-modulated capillary filling dynamics of immiscible fluids.

    PubMed

    Bandopadhyay, Aditya; Mandal, Shubhadeep; Chakraborty, Suman

    2016-02-21

    The pressure driven transport of two immiscible electrolytes in a narrow channel with prescribed surface potential (zeta potential) is considered under the influence of a flow-induced electric field. The latter consideration is non-trivially and fundamentally different from the problem of electric field-driven motion (electroosmosis) of two immiscible electrolytes in a channel in a sense that in the former case, the genesis of the induced electric field, termed as streaming potential, is the advection of ions in the absence of any external electric field. As the flow occurs, one fluid displaces the other. Consequently, in cases where the conductivities of the two fluids differ, imbibition dynamically alters the net conductivity of the channel. We emphasize, through numerical simulations, that the alteration in the net conductivity has a significant impact on the contact line dynamics and the concomitant induced streaming potential. The results presented herein are expected to shed light on multiphase electrokinetics devices. PMID:26758228

  12. Covalent Fusion of layered Incompatible Gels in Immiscible Solvents

    NASA Astrophysics Data System (ADS)

    Biswas, Santidan; Singh, Awaneesh; Matyjaszewski, Krzysztof; Balazs, Anna C.

    We carry out dissipative particle dynamics (DPD) simulations to model a two layered stackable gel where the gels are incompatible and are present in immiscible solvent. The bottom layer of the gel is created first and then a solution of new initiators, monomers and cross-linkers is introduced on top of it. These components then undergo polymerization and form the second gel layer. We study all possible combinations of free radical polymerization (FRP) and atom transfer radical polymerization (ATRP) mechanisms with the two layers of the gel. For example, the bottom layer gel is created via ATRP, whereas the top layer gel follows FRP. Our focus is to do a systematic study of all these combinations and find out the factors responsible for combining two incompatible gels in immiscible solvents.

  13. Immiscible fluid: Heat of fusion heat storage system

    NASA Technical Reports Server (NTRS)

    Edie, D. D.; Melsheimer, S. S.; Mullins, J. C.

    1980-01-01

    Both heat and mass transfer in direct contact aqueous crystallizing systems were studied as part of a program desig- ned to evaluate the feasibility of direct contact heat transfer in phase change storage using aqueous salt system. Major research areas, discussed include (1) crystal growth velocity study on selected salts; (2) selection of salt solutions; (3) selection of immiscible fluids; (4) studies of heat transfer and system geometry; and (5) system demonstration.

  14. Electric-Field-Assisted Droplet Dispensing on Immiscible Fluids

    NASA Astrophysics Data System (ADS)

    Uhm, Taewoong; Hong, Jiwoo; Lee, Sang Joon; Kang, In Seok

    2014-11-01

    Dispensing tiny droplets is a basic and crucial process in numerous practical applications, such as printed electronics, DNA microarray, and digital microfluidics. The precise positioning with demanded size of droplets is the main issue of dispensing tiny droplets. Furthermore, capability of dispensing charged droplets on the immiscible fluids could bring out more utilities. In this work, we demonstrate the droplet dispensing on immiscible fluids by means of electrical charge concentration (ECC). This results from the fact that the droplet is generated by electric force caused by electric induction between the surface of droplet and the immiscible fluid. The temporal evolution of the droplet-dispensing process was observed consecutively with a high-speed camera. In addition, the relationship between the size of dispensed droplet and the parameters, such as physical properties of fluids and electrical field strength, is established. This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (Grant Number: 2013R1A1A2011956).

  15. NOVEL FISSION PRODUCT SEPARATION BASED ON ROOM-TEMPERATURE IONIC LIQUIDS

    SciTech Connect

    Hussey, Charles L.

    2004-06-01

    The DoE/NE underground storage tanks at Hanford, SRS, and INEEL contain liquid wastes with high concentrations of radioactive species, mainly 137Cs and 90Sr. Because the other components of the liquid waste are mainly sodium nitrate and sodium hydroxide, most of this tank waste can be treated inexpensively as low-level waste if 137Cs and 90Sr can be selectively removed. Many ionophores (crown ether and calixarene compounds) have been synthesized for the purpose of selectively extracting Cs+ and Sr2+ from an aqueous phase into an immiscible organic phase. Recent studies conducted at ORNL1,2 reveal that hydrophobic ionic liquids might be better solvents for extracting metal ions from aqueous solutions with these ionophores than conventional immiscible organic solvents, such as benzene, toluene, and dichloromethane, because both Cs+ and Sr2+ exhibit larger distribution coefficients in the ionic liquids. In addition, the vapor pressures of these ionic liquids are insignificant. Thus, there is little or no vaporization loss of these solvents. Most of the ionic liquids under investigation are relatively nontoxic compared to the hydrocarbon solvents that they replace, classifying them as ''green'' solvents.

  16. Experiments on the impact and turbulent coalescence of a blob at a liquid-liquid interface

    NASA Astrophysics Data System (ADS)

    Landeau, Maylis; Olson, Peter; Deguen, Renaud; Hirsh, Ben; Earth; Planetary Sciences Team

    2015-11-01

    We present experiments on finite liquid volumes, hereafter referred to as blobs, of variable densities impacting an interface between two immiscible liquids at high Reynolds and Weber numbers. Such processes occurred on a massive scale during the giant impacts that formed terrestrial planets and satellites, including the Earth and the Moon. We find that the fall distance of the blob controls an abrupt transition in coalescence regime and in the amount of mixing with the lower liquid. This transition coincides with a brief and global breakup of the impacting blob into drops. For small fall distances, the large-scale flow following impact behaves as a turbulent fountain: a mixture of immiscible liquids penetrates in the lower liquid, collapses and spreads along the immiscible interface. We derive an experimental scaling relation for turbulent mixing of the impacting blob with the lower liquid as a function of a Richardson number.

  17. Investigation of liquid phase axial dispersion in Taylor bubble flow by radiotracer residence time distribution analysis

    NASA Astrophysics Data System (ADS)

    Chughtai, I. R.; Iqbal, W.; Din, G. U.; Mehdi, S.; Khan, I. H.; Inayat, M. H.; Jin, J. H.

    2013-05-01

    A gas-liquid Taylor bubble flow occurs in small diameter channels in which gas bubbles are separated by slugs of pure liquid. This type of flow regime is well suited for solid catalyzed gas-liquid reactors in which the reaction efficiency is a strong function of axial dispersion in the regions of pure liquid. This paper presents an experimental study of liquid phase axial dispersion in a Taylor bubble flow developed in a horizontal tube using high speed photography and radiotracer residence time distribution (RTD) analysis. A parametric dependence of axial dispersion on average volume fraction of gas phase was also investigated by varying the relative volumetric flow rates of the two phases. 137mBa produced from a 137Cs/137mBa radionuclide generator was used as radiotracer and measurements were made using the NaI(Tl) scintillation detectors. Validation of 137mBa in the form of barium chloride as aqueous phase radiotracer was also carried out. Axial Dispersion Model (ADM) was used to simulate the hydrodynamics of the system and the results of the experiment are presented. It was observed that the system is characterized by very high values of Peclet Number (Pe˜102) which reveals an approaching plug type flow. The experimental and model estimated values of mean residence times were observed in agreement with each other.

  18. Visualization of residual organic liquid trapped in aquifers

    SciTech Connect

    Conrad, S.H.; Wilson, J.L.; Mason, W.R.; Peplinski, W.J. )

    1992-02-01

    Organic liquids that are essentially immiscible with water migrate through the subsurface under the influence of capillary, viscous, and buoyancy forces. These liquids originate from the improper disposal of hazardous wastes, and the spills and leaks of petroleum hydrocarbons and solvents. The flow visualization experiments described in this study examined the migration of organic liquids through the saturated zone of aquifers, with a primary focus on the behavior of the residual organic liquid saturation, referring to that portion of the organic liquid that is trapped by capillary forces. Etched glass micromodels were used to visually observe dynamic multiphase displacement processes in pore networks. The resulting fluid distributions were photographed. Pore and blob casts were produced by a technique in which an organic liquid was solidified in place within a sand column at the conclusion of a displacement. The columns were sectioned and examined under optical and scanning electron microscopes. Photomicrographs of these sections show the morphology of the organic phase and its location within the sand matrix. The photographs from both experimental techniques reveal that in the saturated zone large amounts of residual organic liquid are trapped as isolated blobs of microscopic size. The size, shape, and spatial distribution of these blobs of residual organic liquid affect the dissolution of organic liquid into the water phase and the biotransformation of organic components. These processes are of concern for the prediction of pollution migration and the design of aquifer remediation schemes.

  19. Equilibrium distribution of samarium and europium between fluoride salt melts and liquid bismuth

    NASA Astrophysics Data System (ADS)

    Zagnit'ko, A. V.; Ignat'ev, V. V.

    2016-01-01

    The extraction of samarium and europium from a melt of a molar composition 73LiF-27BeF2 into liquid bismuth with additions of lithium as a reducing agent at a temperature of 600-610°C was studied. The equilibrium distribution coefficients of samarium and europium were measured. In the metal fluoride salt melt under study, the valence of samarium and europium was shown to be equal to two.

  20. Orientational order of solutes in liquid crystals: The effect of distributed electric quadrupoles

    NASA Astrophysics Data System (ADS)

    Lee, J. S. J.; Sokolovskii, R. O.; Berardi, R.; Zannoni, C.; Burnell, E. E.

    2008-03-01

    We perform Monte Carlo simulations of a mixture of soft ellipsoids with embedded quadrupoles as a model of various small molecules dissolved in nematic liquid crystals. We find that Gay-Berne ellipsoids with distributed embedded quadrupoles qualitatively reproduce the trend in the order parameters observed experimentally in NMR spectra. In contrast, ellipsoids with a single embedded quadrupole cannot reproduce the negative order parameter of acetylene in EBBA.

  1. Size Distribution and Velocity of Ethanol Drops in a Rocket Combustor Burning Ethanol and Liquid Oxygen

    NASA Technical Reports Server (NTRS)

    Ingebo, Robert D.

    1961-01-01

    Single jets of ethanol were studied photomicrographically inside a rocket chamber as they broke up into sprays of drops which underwent simultaneous acceleration and vaporization with chemical reaction occurring in the surrounding combustion gas stream. In each rocket test-firing, liquid oxygen was used as the oxidant. Both drop velocity and drop size distribution data were obtained from photomicrographs of the ethanol drops taken with an ultra-high speed tracking camera developed at NASA, Lewis Research Center.

  2. Equilibrium distribution of lanthanum, neodymium, and thorium between lithium chloride melt and liquid bismuth

    NASA Astrophysics Data System (ADS)

    Zagnit'ko, A. V.; Ignat'ev, V. V.

    2013-04-01

    The distribution of lanthanum, neodymium, and thorium between a lithium chloride melt and liquid bismuth with additions of lithium as a reducing agent are investigated at 650°C. Equilibrium values of their distribution constants are measured. It is shown that in contrast to neodymium and lanthanum, thorium cannot be extracted from bismuth into lithium chloride. This allows us to propose an efficient scheme for separating lanthanides and thorium in a system for the extraction of fuel salts in molten-salt nuclear reactors.

  3. Distribution of binding energies of a water molecule in the water liquid-vapor interface

    SciTech Connect

    Chempath, Shaji; Pratt, Lawrence R

    2008-01-01

    Distributions of binding energies of a water molecule in the water liquid-vapor interface are obtained on the basis of molecular simulation with the SPC/E model of water. These binding energies together with the observed interfacial density profile are used to test a minimally conditioned Gaussian quasi-chemical statistical thermodynamic theory. Binding energy distributions for water molecules in that interfacial region clearly exhibit a composite structure. A minimally conditioned Gaussian quasi-chemical model that is accurate for the free energy of bulk liquid water breaks down for water molecules in the liquid-vapor interfacial region. This breakdown is associated with the fact that this minimally conditioned Gaussian model would be inaccurate for the statistical thermodynamics of a dilute gas. Aggressive conditioning greatly improves the performance of that Gaussian quasi-chemical model. The analogy between the Gaussian quasi-chemical model and dielectric models of hydration free energies suggests that naive dielectric models without the conditioning features of quasi-chemical theory will be unreliable for these interfacial problems. Multi-Gaussian models that address the composite nature of the binding energy distributions observed in the interfacial region might provide a mechanism for correcting dielectric models for practical applications.

  4. Interfacial tension between immiscible melts in the system K2O - FeO - Fe2O3 - Al2O3 - SiO2

    NASA Astrophysics Data System (ADS)

    Kaehn, J.; Veksler, I. V.; Franz, G.; Dingwell, D. B.

    2009-12-01

    Interfacial tension is a very important parameter of the kinetics of phase nucleation, dissolution and growth. Excess surface energy contributes to the energy barrier for phase nucleation, and works as the main driving force for minimization of phase contact surfaces in heterogeneous systems. Immiscible silicate melts have been found to form in a broad range of basaltic, dacitic and rhyolitic magmas (Philpotts, 1982). However, liquid-liquid interfaces remain poorly studied in comparison with crystal-melt and vapor-melt interfaces. Here we present first experimental measurements of interfacial tension between synthetic Fe-rich and silica-rich immiscible melts composed of Fe oxides, K2O, alumina and silica. According to Naslund (1983), the miscibility gap in the 5-oxide system expands with increasing fO2 and becomes widest in air (fO2 = 0.2). Our goal was to estimate the maximal liquid-liquid interfacial tension for the immiscible liquids composed of silica and Fe oxides. Therefore, we have chosen the most contrasting liquid compositions that coexist in air at and above 1465 °C. Silica-rich and Fe-rich conjugate liquids at these conditions contain 73 and 17 wt. % SiO2, and 14 and 80 wt. % FeOt, respectively. These starting compositions were synthesized by fusion of reagent-grade oxides and K2CO3 at 1600 °C. In addition to interfacial tension, we have measured density and surface tension of individual coexisting liquids. All the measurements were done at 1500, 1527 and 1550 °C. Density was measured by the Archimedean method; surface and interfacial tensions were calculated from the maximal pool on a vertical cylinder (a 3-mm Pt rod attached to a high precision balance). We found interfacial tension between the immiscible liquids to decrease with increasing temperature from 16.4±2 mN/m at 1500 °C to 8.2±0.8 mN/m at 1550 °C. These values are approximately 2 orders of magnitude lower than typical interfacial tensions between silicate melts and crystals (Wanamaker

  5. LABORATORY INVESTIGATION OF RESIDUAL LIQUID ORGANICS FROM SPILLS, LEAKS, AND THE DISPOSAL OF HAZARDOUS WASTES IN GROUNDWATER

    EPA Science Inventory

    Organic liquids that are essentially immiscible with water migrate through the subsurface under the influence of capillary, viscous, and buoyancy forces. These liquids originate from the improper disposal of hazardous wastes, and the spills and leaks of petroleum hydrocarbons a...

  6. Study on the spatial distribution of the liquid temperature near a cavitation bubble wall.

    PubMed

    Shen, Yang; Yasui, Kyuichi; Sun, Zhicheng; Mei, Bin; You, Meiyan; Zhu, Tong

    2016-03-01

    A simple new model of the spatial distribution of the liquid temperature near a cavitation bubble wall (Tli) is employed to numerically calculate Tli. The result shows that Tli is almost same with the ambient liquid temperature (T0) during the bubble oscillations except at strong collapse. At strong collapse, Tli can increase to about 1510 K, the same order of magnitude with that of the maximum temperature inside the bubble, which means that the chemical reactions occur not only in gas-phase inside the collapsing bubble but also in liquid-phase just outside the collapsing bubble. Four factors (ultrasonic vibration amplitude, ultrasonic frequency, the surface tension and the viscosity) are considered to study their effects for the thin liquid layer. The results show that for the thin layer, the thickness and the temperature increase as the ultrasonic vibration amplitude rise; conversely, the thickness and the temperature decrease with the increase of the ultrasonic frequency, the surface tension or the viscosity. PMID:26585020

  7. Liquid electrode

    DOEpatents

    Ekechukwu, A.A.

    1994-07-05

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

  8. Calculated depth-dose distributions for H + and He + beams in liquid water

    NASA Astrophysics Data System (ADS)

    Garcia-Molina, Rafael; Abril, Isabel; Denton, Cristian D.; Heredia-Avalos, Santiago; Kyriakou, Ioanna; Emfietzoglou, Dimitris

    2009-08-01

    We have calculated the dose distribution delivered by proton and helium beams in liquid water as a function of the target-depth, for incident energies in the range 0.5-10 MeV/u. The motion of the projectiles through the stopping medium is simulated by a code that combines Monte Carlo and a finite differences algorithm to consider the electronic stopping power, evaluated in the dielectric framework, and the multiple nuclear scattering with the target nuclei. Changes in projectile charge-state are taken into account dynamically as it moves through the target. We use the MELF-GOS model to describe the energy loss function of liquid water, obtaining a value of 79.4 eV for its mean excitation energy. Our calculated stopping powers and depth-dose distributions are compared with those obtained using other methods to describe the energy loss function of liquid water, such as the extended Drude and the Penn models, as well as with the prediction of the SRIM code and the tables of ICRU.

  9. Mapping drug distribution in brain tissue using liquid extraction surface analysis mass spectrometry imaging.

    PubMed

    Swales, John G; Tucker, James W; Spreadborough, Michael J; Iverson, Suzanne L; Clench, Malcolm R; Webborn, Peter J H; Goodwin, Richard J A

    2015-10-01

    Liquid extraction surface analysis mass spectrometry (LESA-MS) is a surface sampling technique that incorporates liquid extraction from the surface of tissue sections with nanoelectrospray mass spectrometry. Traditional tissue analysis techniques usually require homogenization of the sample prior to analysis via high-performance liquid chromatography mass spectrometry (HPLC-MS), but an intrinsic weakness of this is a loss of all spatial information and the inability of the technique to distinguish between actual tissue penetration and response caused by residual blood contamination. LESA-MS, in contrast, has the ability to spatially resolve drug distributions and has historically been used to profile discrete spots on the surface of tissue sections. Here, we use the technique as a mass spectrometry imaging (MSI) tool, extracting points at 1 mm spatial resolution across tissue sections to build an image of xenobiotic and endogenous compound distribution to assess drug blood-brain barrier penetration into brain tissue. A selection of penetrant and "nonpenetrant" drugs were dosed to rats via oral and intravenous administration. Whole brains were snap-frozen at necropsy and were subsequently sectioned prior to analysis by matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI) and LESA-MSI. MALDI-MSI, as expected, was shown to effectively map the distribution of brain penetrative compounds but lacked sufficient sensitivity when compounds were marginally penetrative. LESA-MSI was used to effectively map the distribution of these poorly penetrative compounds, highlighting its value as a complementary technique to MALDI-MSI. The technique also showed benefits when compared to traditional homogenization, particularly for drugs that were considered nonpenetrant by homogenization but were shown to have a measurable penetration using LESA-MSI. PMID:26350423

  10. Rayleigh-Taylor instability of immiscible fluids in porous media

    NASA Astrophysics Data System (ADS)

    Kalisch, H.; Mitrovic, D.; Nordbotten, J. M.

    2016-05-01

    The time development of an interface separating two immiscible fluids of different densities in heterogeneous two-dimensional porous media is studied. The governing equations are simplified with the help of approximate Green's functions which allow computation of the shape of the interface directly without resolving the fluid flow in the entire domain. The new formulation is amenable to numerical approximation, and the reduction in dimension leads to a significant gain in efficiency in the numerical simulation of the interfacial dynamics. Several test cases are investigated, and the numerical solutions are compared to known exact solutions and experimental data.

  11. A nanoglass alloying immiscible Fe and Cu at the nanoscale.

    PubMed

    Chen, Na; Wang, Di; Feng, Tao; Kruk, Robert; Yao, Ke-Fu; Louzguine-Luzgin, Dmitri V; Hahn, Horst; Gleiter, Herbert

    2015-04-21

    Synthesized from ultrafine particles with a bottom-up approach, nanoglasses are of particular importance in pursuing unique properties. Here, we design a metallic nanoglass alloy from two components of ∼Cu64Sc36 and ∼Fe90Sc10 nanoglasses. With nanoalloying mutually immiscible Fe and Cu, the properties of the nanoglass alloys can be tuned by varying the proportions of the ∼Fe90Sc10 component. This offers opportunity to create novel metallic glass nanocomposites and sheds light on building a structure-property correlation for the nanoglass alloys. PMID:25792519

  12. Nanomaterial size distribution analysis via liquid nebulization coupled with ion mobility spectrometry (LN-IMS).

    PubMed

    Jeon, Seongho; Oberreit, Derek R; Van Schooneveld, Gary; Hogan, Christopher J

    2016-02-21

    We apply liquid nebulization (LN) in series with ion mobility spectrometry (IMS, using a differential mobility analyzer coupled to a condensation particle counter) to measure the size distribution functions (the number concentration per unit log diameter) of gold nanospheres in the 5-30 nm range, 70 nm × 11.7 nm gold nanorods, and albumin proteins originally in aqueous suspensions. In prior studies, IMS measurements have only been carried out for colloidal nanoparticles in this size range using electrosprays for aerosolization, as traditional nebulizers produce supermicrometer droplets which leave residue particles from non-volatile species. Residue particles mask the size distribution of the particles of interest. Uniquely, the LN employed in this study uses both online dilution (with dilution factors of up to 10(4)) with ultra-high purity water and a ball-impactor to remove droplets larger than 500 nm in diameter. This combination enables hydrosol-to-aerosol conversion preserving the size and morphology of particles, and also enables higher non-volatile residue tolerance than electrospray based aerosolization. Through LN-IMS measurements we show that the size distribution functions of narrowly distributed but similarly sized particles can be distinguished from one another, which is not possible with Nanoparticle Tracking Analysis in the sub-30 nm size range. Through comparison to electron microscopy measurements, we find that the size distribution functions inferred via LN-IMS measurements correspond to the particle sizes coated by surfactants, i.e. as they persist in colloidal suspensions. Finally, we show that the gas phase particle concentrations inferred from IMS size distribution functions are functions of only of the liquid phase particle concentration, and are independent of particle size, shape, and chemical composition. Therefore LN-IMS enables characterization of the size, yield, and polydispersity of sub-30 nm particles. PMID:26750519

  13. The distribution of Sr and REE between diopside and silicate liquid. [Rare Earth Elements

    NASA Technical Reports Server (NTRS)

    Grutzeck, M.; Kridelbaugh, S.; Weill, D.

    1974-01-01

    Experimental determination of the distribution coefficients in diopside-liquid pairs for strontium and nine rare-earth elements in the system CaMgSi2O6-NaAlSi3O8-CaAl2Si2O8. In experiments in air at 1265 C it is found that most of the Sr(2+), Eu(2+), and RE(3+) ions substitute for Ca(2+) and, in addition, a coupled substitution of Al(3+) for Si(4+) occurs. All of the trace ions considered are found to be excluded from the diopside lattice relative to the liquid. In the case of the trivalent ions the exclusion is much more pronounced for La and Ce, which have ionic radii larger than that of Ca(2+) in 8-fold oxygen coordination. Divalent Sr and Eu with even larger radii are also strongly excluded.

  14. Flow field distribution of liquid film of water lubricated bearing-rotor coupling systems

    NASA Astrophysics Data System (ADS)

    Hu, Q. L.; Hu, J. N.; Ye, X. Y.; Zhang, D. S.; Zheng, J. B.

    2016-05-01

    According to the desalination high-pressure pump water lubricated bearing-rotor coupling systems flow field distribution of liquid film in the starting transient process and its power transmission mechanism can lay the foundation of further exploring and judging lubrication state at the boot process. By using the computational fluid dynamics Fluent secondary development platform and calling the relevant DEFINE macro function to achieve the translation and rotation movement of the journal, we will use the dynamic grid technique to realize the automatic calculation and grid update of water lubricated bearings 3d unsteady liquid film flow field, and finally we will dispose the results of numerical simulation and get the pressure. When the eccentricity is large, film thickness was negatively correlated with the pressure, and positive with the velocity. Differential pressure was negatively correlated with velocity. When the eccentricity is small, film thickness is no significant relationship with differential pressure and velocity. Differential pressure has little difference with velocity.

  15. Experimental triplet and quadruplet fluctuation densities and spatial distribution function integrals for pure liquids

    SciTech Connect

    Ploetz, Elizabeth A.; Karunaweera, Sadish; Smith, Paul E.

    2015-01-28

    Fluctuation solution theory has provided an alternative view of many liquid mixture properties in terms of particle number fluctuations. The particle number fluctuations can also be related to integrals of the corresponding two body distribution functions between molecular pairs in order to provide a more physical picture of solution behavior and molecule affinities. Here, we extend this type of approach to provide expressions for higher order triplet and quadruplet fluctuations, and thereby integrals over the corresponding distribution functions, all of which can be obtained from available experimental thermodynamic data. The fluctuations and integrals are then determined using the International Association for the Properties of Water and Steam Formulation 1995 (IAPWS-95) equation of state for the liquid phase of pure water. The results indicate small, but significant, deviations from a Gaussian distribution for the molecules in this system. The pressure and temperature dependence of the fluctuations and integrals, as well as the limiting behavior as one approaches both the triple point and the critical point, are also examined.

  16. Experimental triplet and quadruplet fluctuation densities and spatial distribution function integrals for pure liquids.

    PubMed

    Ploetz, Elizabeth A; Karunaweera, Sadish; Smith, Paul E

    2015-01-28

    Fluctuation solution theory has provided an alternative view of many liquid mixture properties in terms of particle number fluctuations. The particle number fluctuations can also be related to integrals of the corresponding two body distribution functions between molecular pairs in order to provide a more physical picture of solution behavior and molecule affinities. Here, we extend this type of approach to provide expressions for higher order triplet and quadruplet fluctuations, and thereby integrals over the corresponding distribution functions, all of which can be obtained from available experimental thermodynamic data. The fluctuations and integrals are then determined using the International Association for the Properties of Water and Steam Formulation 1995 (IAPWS-95) equation of state for the liquid phase of pure water. The results indicate small, but significant, deviations from a Gaussian distribution for the molecules in this system. The pressure and temperature dependence of the fluctuations and integrals, as well as the limiting behavior as one approaches both the triple point and the critical point, are also examined. PMID:25637990

  17. Experimental triplet and quadruplet fluctuation densities and spatial distribution function integrals for pure liquids

    PubMed Central

    Karunaweera, Sadish

    2015-01-01

    Fluctuation solution theory has provided an alternative view of many liquid mixture properties in terms of particle number fluctuations. The particle number fluctuations can also be related to integrals of the corresponding two body distribution functions between molecular pairs in order to provide a more physical picture of solution behavior and molecule affinities. Here, we extend this type of approach to provide expressions for higher order triplet and quadruplet fluctuations, and thereby integrals over the corresponding distribution functions, all of which can be obtained from available experimental thermodynamic data. The fluctuations and integrals are then determined using the International Association for the Properties of Water and Steam Formulation 1995 (IAPWS-95) equation of state for the liquid phase of pure water. The results indicate small, but significant, deviations from a Gaussian distribution for the molecules in this system. The pressure and temperature dependence of the fluctuations and integrals, as well as the limiting behavior as one approaches both the triple point and the critical point, are also examined. PMID:25637990

  18. Simple method for highlighting the temperature distribution into a liquid sample heated by microwave power field

    SciTech Connect

    Surducan, V.; Surducan, E.; Dadarlat, D.

    2013-11-13

    Microwave induced heating is widely used in medical treatments, scientific and industrial applications. The temperature field inside a microwave heated sample is often inhomogenous, therefore multiple temperature sensors are required for an accurate result. Nowadays, non-contact (Infra Red thermography or microwave radiometry) or direct contact temperature measurement methods (expensive and sophisticated fiber optic temperature sensors transparent to microwave radiation) are mainly used. IR thermography gives only the surface temperature and can not be used for measuring temperature distributions in cross sections of a sample. In this paper we present a very simple experimental method for temperature distribution highlighting inside a cross section of a liquid sample, heated by a microwave radiation through a coaxial applicator. The method proposed is able to offer qualitative information about the heating distribution, using a temperature sensitive liquid crystal sheet. Inhomogeneities as smaller as 1°-2°C produced by the symmetry irregularities of the microwave applicator can be easily detected by visual inspection or by computer assisted color to temperature conversion. Therefore, the microwave applicator is tuned and verified with described method until the temperature inhomogeneities are solved.

  19. Effects of nanoclay and conductive carbon black on morphology development in chaotic mixing of immiscible polymers

    NASA Astrophysics Data System (ADS)

    Dharaiya, Dhawal

    Chaotic mixing of immiscible polymer blends has been known to produce morphological features such as lamellas, fibrils and droplets. In this research work, we studied the effect of fillers, such as carbon black (CB) and organically treated nanoclay, on morphology development in an immiscible polymer system, consisting of polyamide 6 (PA6) and polypropylene (PP) in a chaotic mixer. Operating conditions were chosen such that chaotic mixing was widespread inside the mixer. The filler particles were mixed with minor component PP before blending with PA6. It was found that continuous lamellar and fibrillar morphology of PP formed early in mixing produced double percolating conductive networks with only 1 wt% CB particles. The conductive networks sustained their existence even after fibrils broke into droplets. This was attributed to migration of CB particles from the bulk of PP droplets and selective localization at the interfaces of closely spaced PP droplets. It was also found that much smaller PP droplets resulted in the presence of CB particles. Prior reports in literature indicated that organically treated nanoclay particles can act as compatibilizer of immiscible polymer blends, although no study showed that how nanoclay would influence morphology development. In this study, we showed that clay particles helped produce PP droplets of much smaller size and with narrower size distribution due to their direct influence on breakup of PP domains. The clay particles reduced interfacial tension between PP and PA6 phases. Consequently, the PP domains sustained lamellar and fibrillar forms and significantly thin fibrils were formed. These thin fibrils in turn broke rapidly into smaller droplets. It was also found that a large fraction of clay particles migrated into PA6 phase and contained intercalated PA6 chains in their galleries. This indicated that clay particles did not participate in compatibilization in this system. The effect of degradation of surface treatment of

  20. Intrusive rocks viewed from fitness landscape diagrams: Evolution and immiscibility

    NASA Astrophysics Data System (ADS)

    Vigneresse, J. D.

    2011-12-01

    We introduce the hard-soft acid-base concepts to magma evolution. Those concepts and their derived chemical parameters provide a new insight into mantle- and continental-derived magmas. Hence magma evolution represents a free suite of chemical reactions, thus showing natural chemical trends. They should be controlled by the principles of maximum hardness and minimum electrophilicity that rule chemical reactions. When plotting into a fitness landscape diagram, rocks suites define two major tendencies. Mantle-derived rocks present all character of an closed chemical system. Conversely, rocks contaminated within the continental crust define two other trends, depending on whether they have affinities toward a silica pole or an alkaline one. They both show the character of an open chemical system. When plotting major igneous minerals onto that diagram shows the importance of olivine, silica and alkali-bearing oxides. It points to the development of immiscibility, depending on the path along which magmas evolve. It thus provides explanation to experimentally observed immiscibility.

  1. BHR equations re-derived with immiscible particle effects

    SciTech Connect

    Schwarzkopf, John Dennis; Horwitz, Jeremy A.

    2015-05-01

    Compressible and variable density turbulent flows with dispersed phase effects are found in many applications ranging from combustion to cloud formation. These types of flows are among the most challenging to simulate. While the exact equations governing a system of particles and fluid are known, computational resources limit the scale and detail that can be simulated in this type of problem. Therefore, a common method is to simulate averaged versions of the flow equations, which still capture salient physics and is relatively less computationally expensive. Besnard developed such a model for variable density miscible turbulence, where ensemble-averaging was applied to the flow equations to yield a set of filtered equations. Besnard further derived transport equations for the Reynolds stresses, the turbulent mass flux, and the density-specific volume covariance, to help close the filtered momentum and continuity equations. We re-derive the exact BHR closure equations which include integral terms owing to immiscible effects. Physical interpretations of the additional terms are proposed along with simple models. The goal of this work is to extend the BHR model to allow for the simulation of turbulent flows where an immiscible dispersed phase is non-trivially coupled with the carrier phase.

  2. Molecular dynamics of immiscible fluids in chemically patterned nanochannels

    NASA Astrophysics Data System (ADS)

    Cieplak, Marek; Banavar, Jayanth R.

    2008-03-01

    Molecular dynamics simulations of chain molecules are used to elucidate physical phenomena involved in flows of dense immiscible fluids in nanochannels. We first consider a force driven flow in which the channel walls are homogeneous and wetting to one fluid and nonwetting to the other fluid. The coating of the walls by the wetting fluid provides a fluctuating surface that confines the flow of the nonwetting fluid. The resulting dissipation yields stationary Poiseuille-like flows in contrast to the accelerating nature of flow in the absence of the coating. We then consider walls consisting of patches whose wetting preferences to a fluid alternate along the walls. In the resulting flow, the immiscible components exhibit periodic structures in their velocity fields such that the crests are located at the wettability steps in contrast to the behavior of a single fluid for which the crest occurs in the wetting region. We demonstrate that for a single fluid, the modulated velocity field scales with the size of the chain molecules.

  3. The rotating movement of three immiscible fluids - A benchmark problem

    USGS Publications Warehouse

    Bakker, M.; Oude, Essink G.H.P.; Langevin, C.D.

    2004-01-01

    A benchmark problem involving the rotating movement of three immiscible fluids is proposed for verifying the density-dependent flow component of groundwater flow codes. The problem consists of a two-dimensional strip in the vertical plane filled with three fluids of different densities separated by interfaces. Initially, the interfaces between the fluids make a 45??angle with the horizontal. Over time, the fluids rotate to the stable position whereby the interfaces are horizontal; all flow is caused by density differences. Two cases of the problem are presented, one resulting in a symmetric flow field and one resulting in an asymmetric flow field. An exact analytical solution for the initial flow field is presented by application of the vortex theory and complex variables. Numerical results are obtained using three variable-density groundwater flow codes (SWI, MOCDENS3D, and SEAWAT). Initial horizontal velocities of the interfaces, as simulated by the three codes, compare well with the exact solution. The three codes are used to simulate the positions of the interfaces at two times; the three codes produce nearly identical results. The agreement between the results is evidence that the specific rotational behavior predicted by the models is correct. It also shows that the proposed problem may be used to benchmark variable-density codes. It is concluded that the three models can be used to model accurately the movement of interfaces between immiscible fluids, and have little or no numerical dispersion. ?? 2003 Elsevier B.V. All rights reserved.

  4. Semi-empirical analysis of liquid fuel distribution downstream of a plain orifice injector under cross-stream air flow

    NASA Astrophysics Data System (ADS)

    Chin, J. S.; Jiang, H. K.; Cao, M. H.

    1981-07-01

    A simple, flat-fan spray model is proposed, which can with two empirical parameters predict both the value and the position of liquid fuel distribution curve maximums downstream of a plain orifice injector under high-velocity cross flow. It was found that the model is useful in the preliminary design of the fan air flow portion of a turbofan afterburner, due to its ability to predict the influence on liquid fuel distribution of (1) such flow parameters as air velocity and viscosity, pressure and temperature; (2) injector parameters such as diameter and injection velocity; and (3) liquid properties including viscosity, density, and surface tension.

  5. Visualization and understanding of the granulation liquid mixing and distribution during continuous twin screw granulation using NIR chemical imaging.

    PubMed

    Vercruysse, Jurgen; Toiviainen, Maunu; Fonteyne, Margot; Helkimo, Niko; Ketolainen, Jarkko; Juuti, Mikko; Delaet, Urbain; Van Assche, Ivo; Remon, Jean Paul; Vervaet, Chris; De Beer, Thomas

    2014-04-01

    Over the last decade, there has been increased interest in the application of twin screw granulation as a continuous wet granulation technique for pharmaceutical drug formulations. However, the mixing of granulation liquid and powder material during the short residence time inside the screw chamber and the atypical particle size distribution (PSD) of granules produced by twin screw granulation is not yet fully understood. Therefore, this study aims at visualizing the granulation liquid mixing and distribution during continuous twin screw granulation using NIR chemical imaging. In first instance, the residence time of material inside the barrel was investigated as function of screw speed and moisture content followed by the visualization of the granulation liquid distribution as function of different formulation and process parameters (liquid feed rate, liquid addition method, screw configuration, moisture content and barrel filling degree). The link between moisture uniformity and granule size distributions was also studied. For residence time analysis, increased screw speed and lower moisture content resulted to a shorter mean residence time and narrower residence time distribution. Besides, the distribution of granulation liquid was more homogenous at higher moisture content and with more kneading zones on the granulator screws. After optimization of the screw configuration, a two-level full factorial experimental design was performed to evaluate the influence of moisture content, screw speed and powder feed rate on the mixing efficiency of the powder and liquid phase. From these results, it was concluded that only increasing the moisture content significantly improved the granulation liquid distribution. This study demonstrates that NIR chemical imaging is a fast and adequate measurement tool for allowing process visualization and hence for providing better process understanding of a continuous twin screw granulation system. PMID:24211658

  6. Two-Liquid Cartesian Diver

    ERIC Educational Resources Information Center

    Planinsic, G.; Kos, M.; Jerman, R.

    2004-01-01

    It is quite easy to make a version of the well known Cartesian diver experiment that uses two immiscible liquids. This allows students to test their knowledge of density and pressure in explaining the diver's behaviour. Construction details are presented here together with a mathematical model to explain the observations.

  7. Gas-liquid Phase Distribution and Void Fraction Measurements Using the MRI

    NASA Technical Reports Server (NTRS)

    Daidzic, N. E.; Schmidt, E.; Hasan, M. M.; Altobelli, S.

    2004-01-01

    We used a permanent-magnet MRI system to estimate the integral and spatially- and/or temporally-resolved void-fraction distributions and flow patterns in gas-liquid two-phase flows. Air was introduced at the bottom of the stagnant liquid column using an accurate and programmable syringe pump. Air flow rates were varied between 1 and 200 ml/min. The cylindrical non-conducting test tube in which two-phase flow was measured was placed in a 2.67 kGauss MRI with MRT spectrometer/imager. Roughly linear relationship has been obtained for the integral void-fraction, obtained by volume-averaging of the spatially-resolved signals, and the air flow rate in upward direction. The time-averaged spatially-resolved void fraction has also been obtained for the quasi-steady flow of air in a stagnant liquid column. No great accuracy is claimed as this was an exploratory proof-of-concept type of experiment. Preliminary results show that MRI a non-invasive and non-intrusive experimental technique can indeed provide a wealth of different qualitative and quantitative data and is especially well suited for averaged transport processes in adiabatic and diabatic multi-phase and/or multi-component flows.

  8. Experimental triplet and quadruplet fluctuation densities and spatial distribution function integrals for liquid mixtures

    SciTech Connect

    Ploetz, Elizabeth A.; Smith, Paul E.

    2015-03-07

    Kirkwood-Buff or Fluctuation Solution Theory can be used to provide experimental pair fluctuations, and/or integrals over the pair distribution functions, from experimental thermodynamic data on liquid mixtures. Here, this type of approach is used to provide triplet and quadruplet fluctuations, and the corresponding integrals over the triplet and quadruplet distribution functions, in a purely thermodynamic manner that avoids the use of structure factors. The approach is then applied to binary mixtures of water + methanol and benzene + methanol over the full composition range under ambient conditions. The observed correlations between the different species vary significantly with composition. The magnitude of the fluctuations and integrals appears to increase as the number of the most polar molecule involved in the fluctuation or integral also increases. A simple physical picture of the fluctuations is provided to help rationalize some of these variations.

  9. Liquid-crystal variable-focus lenses with a spatially-distributed tilt angles.

    PubMed

    Honma, Michinori; Nose, Toshiaki; Yanase, Satoshi; Yamaguchi, Rumiko; Sato, Susumu

    2009-06-22

    A pretilt angle controlling method by the density of rubbings using a tiny stylus is proposed. The control of the surface pretilt angle is achieved by rubbing a side-chain type polyimide film for a homeotropic alignment. Smooth liquid crystal (LC) director distribution in the bulk layer is successfully obtained even though the rough surface orientation. This approach is applied to LC cylindrical and rectangular lenses with a variable-focusing function. The distribution profile of the rubbing pitch (the reciprocal of the rubbing density) for small aberration is determined to be quadratic. The variable focusing function is successfully achieved in the LC rectangular lens, and the voltage dependence of the focal length is tried to be explained by the LC molecular reorientation behavior. PMID:19550499

  10. A novel numerical approach for the solution of the problem of two-phase, immiscible flow in porous media: Application to LNAPL and DNAPL

    NASA Astrophysics Data System (ADS)

    Salama, Amgad; Sun, Shuyu; El Amin, Mohamed F.

    2012-05-01

    The flow of two immiscible fluids in porous media is ubiquitous particularly in petroleum exploration and extraction. The displacement of one fluid by another immiscible with it represents a very important aspect in what is called enhanced oil recovery. Another example is related to the long-term sequestration of carbon dioxide, CO2, in deep geologic formations. In this technique, supercritical CO2 is introduced into deep saline aquifer where it displaces the hosting fluid. Furthermore, very important classes of contaminants that are very slightly soluble in water and represent a huge concern if they get introduced to groundwater could basically be assumed immiscible. These are called light non-aqueous phase liquids (LNAPL) and dense non-aqueous phase liquids (DNAPL). All these applications necessitate that efficient algorithms be developed for the numerical solution of these problems. In this work we introduce the use of shifting matrices to numerically solving the problem of two-phase immiscible flows in the subsurface. We implement the cell-center finite difference method which discretizes the governing set of partial differential equations in conservative manner. Unlike traditional solution methodologies, which are based on performing the discretization on a generic cell and solve for all the cells within a loop, in this technique, the cell center information for all the cells are obtained all at once without loops using matrix oriented operations. This technique is significantly faster than the traditional looping algorithms, particularly for larger systems when coding using languages that require repeating interpretation each time a loop is called like Mat Lab, Python and the like. We apply this technique to the transport of LNAPL and DNAPL into a rectangular domain.

  11. Dual origin of Fe-Ti-P gabbros by immiscibility and fractional crystallization of evolved tholeiitic basalts in the Sept Iles layered intrusion

    NASA Astrophysics Data System (ADS)

    Namur, Olivier; Charlier, Bernard; Holness, Marian B.

    2012-12-01

    We present a detailed study of two ca. 200 m-thick apatite-bearing ferrogabbro horizons of the Sept Iles layered intrusion (Canada). These rocks are the most evolved cumulates of the megacyclic units (MCU) I and II, and mark the transition between basaltic and silicic magmatism. They are made up of plagioclase (An55-34), olivine (Fo66-21), clinopyroxene (Mg#75-55), ilmenite, magnetite, apatite, ± pigeonite and are a significant source of Fe-Ti-P ore. Ferrogabbros have relatively uniform bulk-rock compositions in MCU I but are bimodal in MCU II. The liquid lines of descent for major elements in equilibrium with cumulates of MCU I and II have been calculated using a forward model formalism. Both trends evolve towards SiO2-enrichment and FeOt-depletion after saturation in Fe-Ti oxides. However, because of magma mixing in MCU II, they do not follow the same path. Evolved liquids from MCU II are shown to enter the experimentally-determined two liquid stability field, while MCU I liquids do not. Immiscibility in MCU II and its absence in MCU I are supported by the presence of contrasted reactive symplectites in cumulate rocks. Apatite-bearing ferrogabbros in MCU II have crystallized from distinct immiscible Fe-rich and Si-rich silicate melts which have physically segregated in the slow-cooling magma chamber. Two different types of cumulate rocks are thus produced: leucocratic and melanocratic gabbros. This is consistent with the presence of Si-rich and Fe-rich melt inclusions in apatite. In contrast, homogeneous ferrogabbros from MCU I were produced by simple fractional crystallization of a homogeneous liquid. Our data suggest that immiscibility could also explain the large geochemical variability of ferrogabbros in the Upper Zone of the Bushveld Complex (South Africa).

  12. Mode-distribution analysis of quasielastic neutron scattering and application to liquid water

    NASA Astrophysics Data System (ADS)

    Kikuchi, Tatsuya; Nakajima, Kenji; Ohira-Kawamura, Seiko; Inamura, Yasuhiro; Yamamuro, Osamu; Kofu, Maiko; Kawakita, Yukinobu; Suzuya, Kentaro; Nakamura, Mitsutaka; Arai, Masatoshi

    2013-06-01

    A quasielastic neutron scattering (QENS) experiment is a particular technique that endeavors to define a relationship between time and space for the diffusion dynamics of atoms and molecules. However, in most cases, analyses of QENS data are model dependent, which may distort attempts to elucidate the actual diffusion dynamics. We have developed a method for processing QENS data without a specific model, wherein all modes can be described as combinations of the relaxations based on the exponential law. By this method, we can obtain a distribution function B(Q,Γ), which we call the mode-distribution function (MDF), to represent the number of relaxation modes and distributions of the relaxation times in the modes. The deduction of MDF is based on the maximum entropy method and is very versatile in QENS data analysis. To verify this method, reproducibility was checked against several analytical models, such as that with a mode of distributed relaxation time, that with two modes closely located, and that represented by the Kohlrausch-Williams-Watts function. We report the first application to experimental data of liquid water. In addition to the two known modes, the existence of a relaxation mode of water molecules with an intermediate time scale has been discovered. We propose that the fast mode might be assigned to an intermolecular motion and the intermediate motion might be assigned to a rotational motion of the water molecules instead of to the fast mode.

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

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Jiang, Y.; Han, Z. J.

    2012-11-01

    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.

  14. Evaporation of a Volatile Liquid Lens on the Surface of an Immiscible Liquid.

    PubMed

    Sun, Wei; Yang, Fuqian

    2016-06-21

    The evaporation behavior of toluene and hexane lenses on the surface of deionized (DI) water is studied. The toluene and hexane lenses during evaporation experience an advancing stage and a receding stage. There exists a significant difference of the evaporation behavior between the toluene lenses and the hexane lenses. The lifetime and largest diameter of both the toluene and hexane lenses increase with increasing the initial volume of the lenses. For the evaporation of the toluene lenses, the lifetime and largest diameter of the lenses decrease with increasing the temperature of DI water. The effect of the residual of the oil molecules on the evaporation of toluene lenses at a temperature of 21 °C is investigated via the evaporation of a series of consecutive toluene lenses being placed on the same position of the surface of DI water. The temporal evolution of the toluene lenses placed after the first toluene lens deviates significantly from that of the first toluene lens. Significant increase of the receding speed occurs at the dimensionless time in a range 0.7-0.8. PMID:27257742

  15. Clast assemblages of possible deep-seated /77517/ and immiscible-melt /77538/ origins in Apollo 17 breccias

    NASA Technical Reports Server (NTRS)

    Warner, R. D.; Taylor, G. J.; Mansker, W. L.; Keil, K.

    1978-01-01

    Breccia samples 77517 and 77538 are composed of abundant mineral and lithic clasts set in porous, poorly sintered matrices. Clast assemblages in the two rocks are of contrasting composition and origin. Breccia 77517 has Mg-rich olivine and pyroxene and calcic plagioclase clasts, indicating limited, almost exclusively ANT-suite parentage. A significant feature is the presence of an assemblage (aluminous enstatite, forsterite, anorthite, aluminous spinel) corresponding to spinel cataclasite, a rock type of deep-seated (about 60 km) crustal origin. Breccia 77538 contains Fe-rich pyroxene and rather sodic plagioclase clasts, indicative of predominantly KREEP and/or mare derivation. An important feature is the occurrence of high-K and high-Fe lithic clasts whose compositions resemble those of immiscible-melts produced during late-stage magmatic crystallization, and which probably originated via silicate liquid immiscibility in a KREEP or mare basalt magma. Both rocks contain numerous fine-grained breccia clasts which represent material that has been modified by impact processes at or very near the moon's surface.

  16. Abnormal alloying behaviour observed in an immiscible Zr Nb system

    NASA Astrophysics Data System (ADS)

    Wang, T. L.; Liang, S. H.; Li, J. H.; Tai, K. P.; Liu, B. X.

    2008-05-01

    For the immiscible Zr-Nb system characterized by a positive heat of formation (+6 kJ mol-1), thermodynamic calculation showed that the Gibbs free energy of the properly designed Zr-Nb multilayered films could be elevated to a higher level than that of the corresponding amorphous phase as well as the supersaturated solid solutions. Accordingly, nano-sized Zr-Nb multilayered films were prepared and then irradiated by 200 keV xenon ions. It was found that amorphous phases could be obtained within a composition range 12-92 at% of Nb. Also, two metastable crystalline phases of fcc structures with different lattice parameters were also obtained. Molecular dynamic simulation was carried out, based on a proven realistic Zr-Nb potential, to reveal the atomistic mechanism of the solid-state crystal-to-amorphous transition. A brief discussion on the formation of the two metastable crystalline phases is presented.

  17. Detachment of Sessile Droplets in Immiscible Fluids Using Electrowetting

    NASA Astrophysics Data System (ADS)

    Hong, Jiwoo; Lee, Sang Joon

    2014-11-01

    The detachment (or removal) of droplets from a solid surface is an indispensable process in numerous practical applications. Here we firstly detach sessile droplets in immiscible fluids from a hydrophobic surface by electrowetting. The critical conditions for droplet detachment are determined by exploring the retracting dynamics for a wide range of driving voltages and physical properties of fluids. The relationships between physical parameters and dynamic characteristics of retracting and jumping droplets, such as contact time and jumping height, are also established. The threshold voltage for droplet detachment in oil with high viscosity is largely reduced by electrowetting actuations with a square pulse. Finally, by using DC and AC electrowetting actuations, we demonstrate the detachment of oil droplets with very low contact angle on a hydrophobic surface in water.

  18. Flow behaviour of negatively buoyant jets in immiscible ambient fluid

    NASA Astrophysics Data System (ADS)

    Geyer, A.; Phillips, J. C.; Mier-Torrecilla, M.; Idelsohn, S. R.; Oñate, E.

    2012-01-01

    In this paper we investigate experimentally the injection of a negatively buoyant jet into a homogenous immiscible ambient fluid. Experiments are carried out by injecting a jet of dyed fresh water through a nozzle in the base of a cylindrical tank containing rapeseed oil. The fountain inlet flow rate and nozzle diameter were varied to cover a wide range of Richardson Ri (8 × 10-4 < Ri < 1.98), Reynolds Re (467 < Re < 5,928) and Weber We (2.40 < We < 308.56) numbers. Based on the Re, Ri and We values for the experiments, we have determined a regime map to define how these values may control the occurrence of the observed flow types. Whereas Ri plays a stronger role when determining the maximum penetration height, the effect of the Reynolds number is stronger predicting the flow behaviour for a specific nozzle diameter and injection velocity.

  19. Long term stability of immiscible ferrofluid/water interfaces

    NASA Astrophysics Data System (ADS)

    Malouin, Bernard; Posada, David; Hirsa, Amir

    2010-11-01

    Recently we have demonstrated pinned-contact, coupled droplet pairs of aqueous ferrofluids in air that can form electromagnetically-activated capillary switches and oscillators. The great variety of available ferrofluids, however, enables the use of immiscible oil-based ferrofluid droplets in a water environment to obtain the same behavior. Such immersed ferrofluid oscillators exhibit natural frequencies (for 5 mm devices) of about 10 Hz. Here we report on the observation of a gradual increase in the resonant frequency of the system in time. Experimental observations suggest that the drift in the natural frequency is a consequence of changes occurring at the ferrofluid/water interface. The interfacial structure of such a complex system (water, oil, surfactant, iron particles) is examined along with its evolution in time, using various microscopy techniques.

  20. Study on processing immiscible materials in zero gravity

    NASA Technical Reports Server (NTRS)

    Reger, J. L.; Mendelson, R. A.

    1975-01-01

    An experimental investigation was conducted to evaluate mixing immiscible metal combinations under several process conditions. Under one-gravity, these included thermal processing, thermal plus electromagnetic mixing, and thermal plus acoustic mixing. The same process methods were applied during free fall on the MSFC drop tower facility. The design is included of drop tower apparatus to provide the electromagnetic and acoustic mixing equipment, and a thermal model was prepared to design the specimen and cooling procedure. Materials systems studied were Ca-La, Cd-Ga and Al-Bi; evaluation of the processed samples included the morphology and electronic property measurements. The morphology was developed using optical and scanning electron microscopy and microprobe analyses. Electronic property characterization of the superconducting transition temperatures were made using an impedance change-tuned coil method.

  1. Linking granulation performance with residence time and granulation liquid distributions in twin-screw granulation: An experimental investigation.

    PubMed

    Kumar, Ashish; Alakarjula, Maija; Vanhoorne, Valérie; Toiviainen, Maunu; De Leersnyder, Fien; Vercruysse, Jurgen; Juuti, Mikko; Ketolainen, Jarkko; Vervaet, Chris; Remon, Jean Paul; Gernaey, Krist V; De Beer, Thomas; Nopens, Ingmar

    2016-07-30

    Twin-screw granulation is a promising wet granulation technique for the continuous manufacturing of pharmaceutical solid dosage forms. A twin screw granulator displays a short residence time. Thus, the solid-liquid mixing must be achieved quickly by appropriate arrangement of transport and kneading elements in the granulator screw allowing the production of granules with a size distribution appropriate for tableting. The distribution of residence time and granulation liquid is governed by the field conditions (such as location and length of mixing zones) in the twin-screw granulator, thus contain interesting information on granulation time, mixing and resulting sub-processes such as wetting, aggregation and breakage. In this study, the impact of process (feed rate, screw speed and liquid-to-solid ratio) and equipment parameters (number of kneading discs and stagger angle) on the residence time (distribution), the granulation liquid-powder mixing and the resulting granule size distributions during twin-screw granulation were investigated. Residence time and axial mixing data was extracted from tracer maps and the solid-liquid mixing was quantified from moisture maps, obtained by monitoring the granules at the granulator outlet using near infra-red chemical imaging (NIR-CI). The granule size distribution was measured using the sieving method. An increasing screw speed dominantly reduced the mean residence time. Interaction of material throughput with the screw speed and with the number of kneading discs led to most variation in the studied responses including residence time and mixing capacity. At a high screw speed, granulation yield improved due to high axial mixing. However, increasing material throughput quickly lowers the yield due to insufficient mixing of liquid and powder. Moreover, increasing liquid-to-solid ratio resulted in more oversized granules, and the fraction of oversized granules further increased at higher throughput. Although an increasing number

  2. Bulk and Surface Molecular Orientation Distribution in Injection-molded Liquid Crystalline Polymers: Experiment and Simulation

    SciTech Connect

    Fang, J.; Burghardt, W; Bubeck, R; Burgard, S; Fischer, D

    2010-01-01

    Bulk and surface distributions of molecular orientation in injection-molded plaques of thermotropic liquid crystalline polymers (TLCPs) have been studied using a combination of techniques, coordinated with process simulations using the Larson-Doi 'polydomain' model. Wide-angle X-ray scattering was used to map out the bulk orientation distribution. Fourier Transform Infrared Attenuated Total Reflectance (FTIR-ATR) and Near-Edge X-ray Absorption Fine Structure (NEXAFS) were utilized to probe the molecular orientation states to within about {approx}5 {micro}m and {approx}2 nm, respectively, of the sample surface. These noninvasive, surface-sensitive techniques yield reasonable self-consistency, providing complementary validation of the robustness of these methods. An analogy between Larson-Doi and fiber orientation models has allowed the first simulations of TLCP injection molding. The simulations capture many fine details in the bulk orientation distribution across the sample plaque. Direct simulation of surface orientation at the level probed by FTIR-ATR and NEXAFS was not possible due to the limited spatial resolution of the simulations. However, simulation results extracted from the shear-dominant skin region are found to provide a qualitatively accurate indicator of surface orientation. Finally, simulations capture the relation between bulk and surface orientation states across the different regions of the sample plaque.

  3. Immiscibility of magmatic fluids and their relation to Mo and Cu mineralization at the Bangpu porphyry deposit, Tibet, China

    NASA Astrophysics Data System (ADS)

    Luo, Maocheng; Tang, Juxing; Mao, Jingwen; Wang, Liqiang; Chen, Wei; Leng, Qiufeng

    2015-05-01

    The coexistence of aqueous fluid inclusions and silicate melt inclusions in quartz phenocrysts from porphyrites at the Bangpu porphyry Mo-Cu deposit, Tibet, China were examined to characterize the immiscibility processes during the magmatic to hydrothermal transition. The physical and chemical environment during crystallization of the magmas has been reconstructed on the basis of microthermometric experiments and trace element microanalysis. Compositions of melt and brine fluid phases are determined using Synchrotron radiation X-ray fluorescence analysis, SEM-EDS and Laser Raman spectroscopy analyses. Brine fluids were directly exsolved by a crystallizing melt, and the simultaneous entrapment of volatile-rich (brine fluid) and volatile-poor immiscible phases (silicate melt) occurred at 670-700 °C and 1.6-1.95 kbar when the magma had H2O contents between 5 and 6 wt% and crystal contents of 60-80%. A later low-density fluid with a higher Mo concentration exsolved after about 80-90% crystallization had occurred. This fluid contained significant concentrations of Cl, Na, K, Ca, Fe, Cu, Zn, Rb, and small amounts of Mn, Br and Pb. Immiscibility of magmatic fluids can lead to different metal partitioning behaviors between residual melt and volatile phases, which generate variable metal ratios. Copper was partitioned preferentially into the brine phase, in contrast to the behavior observed in other porphyry Cu deposits. Ore deposition by a dense brine could explain the partially deep Cu mineralization. Condensation of brine from a later low-density parental fluid could be an efficient mechanism to concentrate shallow Cu mineralization and broadly distributed Mo mineralization. The source of the Mo mineralizing fluids probably was a particularly large magma chamber that crystallized and fractionated at depth greater than upper continental crust level.

  4. One-step purification of nucleic acid for gene expression analysis via Immiscible Filtration Assisted by Surface Tension (IFAST)†

    PubMed Central

    Berry, Scott M.; Alarid, Elaine T.; Beebe, David J.

    2011-01-01

    The extraction and purification of nucleic acids from complex samples (e.g. blood, biopsied tissue, cultured cells, food) is an essential prerequisite for many applications in biology including genotyping, transcriptional analysis, systems biology, epigenetic analysis, and virus/bacterial detection. In this report, we describe a new process of nucleic acid extraction that utilizes “pinned” aqueous/organic liquid interfaces in microchannels to streamline the extraction mechanism, replacing all washing steps with a single traverse of an immiscible fluid barrier, termed Immiscible Filtration Assisted by Surface Tension (IFAST). Nucleic acids in biological samples are bound to paramagnetic particles and then drawn across the IFAST device (or array of IFAST devices) using a magnet. While the strength of the IFAST barrier is suitable for separation of nucleic acids from lysate in its current embodiment, its permeability can be selectively adapted by adjusting the surface tensions/energies associated with the cell lysate, the immiscible phase, and the device surface, enabling future expansion to other non-nucleic acid applications. Importantly, processing time is reduced from 15–45 minutes to less than 5 minutes while maintaining purity, yield, and scalability equal to or better than prevailing methods. Operation is extremely simple and no additional lab infrastructure is required. The IFAST technology thus significantly enhances researchers’ abilities to isolate and analyze nucleic acids, a process which is critical and ubiquitous in an extensive array of scientific fields. PMID:21423999

  5. Morphology and distribution of liquid inclusions in young sea ice as imaged by magnetic resonance

    NASA Astrophysics Data System (ADS)

    Galley, R. J.; Else, B. G. T.; Geilfus, N.-X.; Hare, A. A.; Isleifson, D.; Ryner, L.; Barber, D. G.; Rysgaard, S.

    2013-10-01

    In order to determine the morphology and distribution of liquid inclusions in young sea ice, magnetic resonance imaging of an 18 cm sea ice core was done using a Siemens 3T TIM TRIO human scanner. The sample was stored at about -20 °C until the beginning of a constructive interference steady state gradient echo sequence which lasted four and a half min. Here we present the first three-dimensional reconstruction of a brine drainage channel network in young sea ice using magnetic resonance imaging. The magnetic resonance image sequence data presented here clearly illustrate that brine drainage channels are established relatively quickly during ice formation, and indicates the amount and location of vertical and horizontal fluid permeability in young sea ice. A simple analysis of the image sequence reveals that magnetic resonance imaging is useful in describing the vertical profile of liquid fraction that compares well to volumes calculated for similar sea ice temperatures. Future work in this vein may include three-dimensional magnetic resonance scans of sea ice cores at in situ temperatures using different magnetic resonance sequences in order to improve the observation of inclusions, though this will necessitate both access to a scanner and the construction of a cooling system compatible with a magnetic resonance imager.

  6. Distribution of trace-element emissions from the liquid-injection incinerator Combustion Research Facility

    SciTech Connect

    Lee, J.W.; Ross, R.W.; Vocque, R.H.; Lewis, J.W.; Waterland, L.R.

    1987-08-01

    A series of tests was conducted at EPA's Combustion Research Facility (CRF) to investigate the fate of volatile trace elements in liquid-injection hazardous-waste incineration. In these tests, arsenic in the form of arsenic trioxide and antimony in the form of antimony trichloride were added to a methanol base containing varying amounts of chlorobenzene and carbon tetrachloride, and fired in the liquid-injection incinerator at the CRF. Test variables included incinerator temperature and excess air level, and feed chlorine content. Test results show a relatively even distribution of both elements between scrubber-exit flue gas and scrubber blowdown. Both elements are found in the vapor phase at high temperatures, though most condenses to particulate at scrubber exit temperatures. Designated POHC destruction and removal efficiency (DRE) ranged from 99.99 to 99.999% at the afterburner exit to 99.999 to 99.9999% in the scrubber-exit flue gas. Typical levels of common products of incomplete combustion were measured.

  7. An Oil-Stream Photomicrographic Aeroscope for Obtaining Cloud Liquid-Water Content and Droplet Size Distributions in Flight

    NASA Technical Reports Server (NTRS)

    Hacker, Paul T.

    1956-01-01

    An airborne cloud aeroscope by which droplet size, size distribution, and liquid-water content of clouds can be determined has been developed and tested in flight and in wind tunnels with water sprays. In this aeroscope the cloud droplets are continuously captured in a stream of oil, which Is then photographed by a photomicrographic camera. The droplet size and size distribution can be determined directly from the photographs. With the droplet size distribution known, the liquid-water content of the cloud can be computed from the geometry of the aeroscope, the airspeed, and the oil-flow rate. The aeroscope has the following features: Data are obtained semi-automatically, and permanent data are taken in the form of photographs. A single picture usually contains a sufficient number of droplets to establish the droplet size distribution. Cloud droplets are continuously captured in the stream of oil, but pictures are taken at Intervals. The aeroscope can be operated in icing and non-icing conditions. Because of mixing of oil in the instrument, the droplet-distribution patterns and liquid-water content values from a single picture are exponentially weighted average values over a path length of about 3/4 mile at 150 miles per hour. The liquid-water contents, volume-median diameters, and distribution patterns obtained on test flights and in the Lewis icing tunnel are similar to previously published data.

  8. Stability of liquid crystalline bridges

    NASA Astrophysics Data System (ADS)

    Mahajan, Milind P.; Tsige, Mesfin; Taylor, P. L.; Rosenblatt, Charles

    1999-02-01

    The stability of cylindrical bridges of the liquid crystal octylcyanobiphenyl in an immiscible liquid bath was investigated in the nematic and smectic A phases. In the nematic phase the bridge was found to destabilize at a length-to-diameter (slenderness) ratio R similar to that of ordinary Newtonian fluids. On the other hand, the Bingham behavior of the smectic A phase, i.e., an apparent yield stress, enabled the formation of stable columns with R well in excess of π.

  9. Low-frequency dilatational wave propagation through unsaturated porous media containing two immiscible fluids

    SciTech Connect

    Lo, W.-C.; Sposito, G.; Majer, E.

    2007-02-01

    An analytical theory is presented for the low-frequency behavior of dilatational waves propagating through a homogeneous elastic porous medium containing two immiscible fluids. The theory is based on the Berryman-Thigpen-Chin (BTC) model, in which capillary pressure effects are neglected. We show that the BTC model equations in the frequency domain can be transformed, at sufficiently low frequencies, into a dissipative wave equation (telegraph equation) and a propagating wave equation in the time domain. These partial differential equations describe two independent modes of dilatational wave motion that are analogous to the Biot fast and slow compressional waves in a single-fluid system. The equations can be solved analytically under a variety of initial and boundary conditions. The stipulation of 'low frequency' underlying the derivation of our equations in the time domain is shown to require that the excitation frequency of wave motions be much smaller than a critical frequency. This frequency is shown to be the inverse of an intrinsic time scale that depends on an effective kinematic shear viscosity of the interstitial fluids and the intrinsic permeability of the porous medium. Numerical calculations indicate that the critical frequency in both unconsolidated and consolidated materials containing water and a nonaqueous phase liquid ranges typically from kHz to MHz. Thus engineering problems involving the dynamic response of an unsaturated porous medium to low excitation frequencies (e.g. seismic wave stimulation) should be accurately modeled by our equations after suitable initial and boundary conditions are imposed.

  10. Average size and size distribution of large droplets produced in a free-jet expansion of a liquid

    NASA Astrophysics Data System (ADS)

    Knuth, E. L.; Henne, U.

    1999-02-01

    The experimental parameters and fluid properties affecting the average size N¯ and the size distribution P(N) of droplets formed by fragmentation of a liquid after expansion into a vacuum are investigated. The mean droplet size is found to be a function of the surface tension of the liquid, the nozzle diameter, and a characteristic flow speed. The size distribution is found to be a linear exponential distribution; measurements deviate from this distribution at small sizes if a factor which is a function of the cluster size is included in the measuring process. Good agreement with measured distributions of both positive and negative droplet ions formed from neutral 4He droplets by electron impact is found. The strong dependence of mean droplet size on source-orifice diameter found in the present analysis indicates that earlier correlations of droplet size with specific entropy in the source were useful at best only for a fixed nozzle size.

  11. Liquid ionization chamber measurements of dose distributions in small 6 MV photon beams

    NASA Astrophysics Data System (ADS)

    Dasu, Alexandru; Löfroth, Per-Olov; Wickman, Göran

    1998-01-01

    A new liquid ionization chamber (LIC) design optimized for high spatial resolution was used for measurements of dose distributions in radiation fields intended for stereotactic radiosurgery (SRS). This work was mainly focused on the properties of this detector in radiation fields from linear accelerators for clinical radiotherapy (pulsed radiation with dose rates from approximately 0.5 to and beam diameters down to 8 mm). The narrow beams used in stereotactic radiosurgery require detectors with small sizes in order to provide a good spatial resolution. The LIC is investigated to see whether it can be used as a detector for dose measurements in beams currently used for stereotactic radiosurgery. Its properties are compared with those of silicon diodes. The comparisons include output factor (OF), depth dose and profile measurements in 6 MV photon fields of different sizes. For OF measurements, an NACP air ionization chamber was also used in the comparison. The dependence of the response on the detector orientation in the photon beam is also investigated for the diodes and the LIC. The results suggest that LICs can provide better properties than diodes for measuring dose distributions in narrow photon beams.

  12. Dynamic evolution process of multilayer core-shell microstructures within containerlessly solidifying Fe(50)Sn(50) immiscible alloy.

    PubMed

    Wang, W L; Wu, Y H; Li, L H; Geng, D L; Wei, B

    2016-03-01

    Multilayer core-shell structures are frequently formed in polymers and alloys when temperature and concentration fields are well symmetrical spatially. Here we report that two- to five-layer core-shell microstructures were the dominant structural morphology of a binary Fe(50)Sn(50) immiscible alloy solidified under the containerless and microgravity states within a drop tube. Three dimensional phase field simulation reveals that both the uniformly dispersive structure and the multilayer core-shells are the various metastable and transitional states of the liquid phase separation process. Only the two-layer core-shell is the most stable microstructure with the lowest chemical potential. Because of the suppression of Stokes motion, solutal Marangoni migration becomes important to drive the evolution of core-shell structures. PMID:27078410

  13. Dynamic evolution process of multilayer core-shell microstructures within containerlessly solidifying F e50S n50 immiscible alloy

    NASA Astrophysics Data System (ADS)

    Wang, W. L.; Wu, Y. H.; Li, L. H.; Geng, D. L.; Wei, B.

    2016-03-01

    Multilayer core-shell structures are frequently formed in polymers and alloys when temperature and concentration fields are well symmetrical spatially. Here we report that two- to five-layer core-shell microstructures were the dominant structural morphology of a binary F e50S n50 immiscible alloy solidified under the containerless and microgravity states within a drop tube. Three dimensional phase field simulation reveals that both the uniformly dispersive structure and the multilayer core-shells are the various metastable and transitional states of the liquid phase separation process. Only the two-layer core-shell is the most stable microstructure with the lowest chemical potential. Because of the suppression of Stokes motion, solutal Marangoni migration becomes important to drive the evolution of core-shell structures.

  14. Mixing Efficiency, Coarsening, and Self-Compatibilization in Immiscible Polymer Blends Processed via Solid-State Shear Pulverization

    NASA Astrophysics Data System (ADS)

    Davydov, Albert; Khait, Klementina; Torkelson, John

    2000-03-01

    Solid-state shear pulverization (SSSP) is a continuous, mechanical alloying process employing simultaneous effects of high pressure and shear deformation to pulverize and mix polymers. Under certain conditions SSSP can result in limited chain scission and polymeric radical formation. In immiscible blends, these radicals may be able to recombine in interfacial regions or regions of high mixing resulting in block copolymer formation and compatibilization. The effects of SSSP on amorphous polyamide (PA)/polystyrene (PS) and PS/low density polyethylene (LDPE) blends have been studied. As compared to melt-mixed blends, SSSP yields blends with enhanced blend morphology refinement or dispersion, and in certain cases enhanced bulk mechanical properties, particularly elongation at break and impact strength. Comparisons of dispersed-phase coarsening during high temperature, liquid-state annealing of the SSSP - processed and conventionally melt-mixed blends will be discussed in terms of the potential for achieving effective compatibilization of particular blends via SSSP.

  15. Effect of elongational flow on immiscible polymer blend/nanoparticle composites: a molecular dynamics study.

    PubMed

    Shebert, George L; Lak Joo, Yong

    2016-07-13

    Using coarse-grained nonequilibrium molecular dynamics, the dynamics of a blend of the equal ratio of immiscible polymers mixed with nanoparticles (NP) are simulated. The simulations are conducted under planar elongational flow, which affects the dispersion of the NPs and the self-assembly morphology. The goal of this study is to investigate the effect of planar elongational flow on the nanocomposite blend system as well as to thoroughly compare the blend to an analogous symmetric block copolymer (BCP) system to understand the role of the polymer structure on the morphology and NP dispersion. Two types of spherical NPs are considered: (1) selective NPs that are attracted to one of the polymer components and (2) nonselective NPs that are neutral to both components. A comparison of the blend and BCP systems reveals that for selective NP, the blend system shows a much broader NP distribution in the selective phase than the BCP phase. This is due to a more uniform distribution of polymer chain ends throughout the selective phase in the blend system than the BCP system. For nonselective NP, the blend and BCP systems show similar results for low elongation rates, but the NP peak in the BCP system broadens as elongation rates approach the order-disorder transition. In addition, the presence of NP is found to affect the morphology transitions of both the blend and BCP systems, depending on the NP type. PMID:27356215

  16. Carbonate-silicate immiscibility and extremely peralkaline silicate glasses from Nasira cone and recent eruptions at Oldoinyo Lengai Volcano, Tanzania

    NASA Astrophysics Data System (ADS)

    Mitchell, Roger H.; Dawson, J. Barry

    2012-11-01

    Phenocrysts of garnet, pyroxene and nepheline in peralkaline nephelinite from the Nasira parasitic cones at Oldoinyo Lengai contain quenched immiscible silicate (peralkalinity = 2-13) and Na-Ca-carbonate melts. Their bulk compositions further define the limits of liquid immiscibility for peralkaline carbonated nephelinite magmas and confirm this process was operative at Oldoinyo Lengai during older stages of activity. Groundmass glasses in Nasira nephelinites are peralkaline (peralkalinity = 5.5-9.5) but less evolved than melt inclusion glasses (peralkalinity = 8-13) in nepheline phenocrysts, implying that these magmas are hybrids formed by magma mixing. Groundmass glass in diverse peralkaline combeite nephelinite ash clasts with and without melilite and/or wollastonite formed in the January-June 2008 eruptions of Oldoinyo Lengai are also exceptionally peralkaline. Two trends in their compositions are evident: (1) increasing peralkalinity from 6 to 10 with SiO2 decreasing from 42 to 33 wt.%; (2) increasing peralkalinity from 6 to 16 with SiO2 decreasing from 45 to 40 wt.%. All recent glasses are considered to be more evolved than groundmass glass in Nasira combeite nephelinite. These data indicate that several varieties of nephelinite exist at Oldoinyo Lengai. Their parental magmas are considered to have been initially enriched in alkalis during partial melting of their metasomatized asthenospheric sources and further by subsequent assimilation, or re-solution, of previously exsolved natrocarbonatite melt in the magma chamber(s) underlying Oldoinyo Lengai. On this basis, none of the bulk compositions of peralkaline stage II lavas at Oldoinyo Lengai, including Nasira, are considered to represent those of liquids as their compositions are determined by rheological factors (phenocryst accumulation; cumulate disruption) and assimilation processes. The formation of combeite is considered to be a consequence of natrocarbonatite melt assimilation.

  17. Benard and Marangoni convection in multiple liquid layers

    NASA Technical Reports Server (NTRS)

    Koster, Jean N.; Prakash, A.; Fujita, D.; Doi, T.

    1992-01-01

    Convective fluid dynamics of immiscible double and triple liquid layers are considered. First results on multilayer convective flow, in preparation for spaceflight experiment aboard IML-2 (International Microgravity Laboratory), are discussed. Convective flow in liquid layers with one or two horizontal interfaces with heat flow applied parallel to them is one of the systems investigated. The second system comprises two horizontally layered immiscible liquids heated from below and cooled from above, that is, heat flow orthogonal to the interface. In this system convection results due to the classical Benard instability.

  18. Quantitative time-averaged gas and liquid distributions using x-ray fluorescence and radiography in atomizing sprays.

    PubMed

    Radke, Christopher D; McManamen, J Patrick; Kastengren, Alan L; Halls, Benjamin R; Meyer, Terrence R

    2015-05-01

    A method for quantitative measurements of gas and liquid distributions is demonstrated using simultaneous x-ray fluorescence and radiography of both phases in an atomizing coaxial spray. Synchrotron radiation at 10.1 keV from the Advanced Photon Source at Argonne National Laboratory is used for x-ray fluorescence of argon gas and two tracer elements seeded into the liquid stream. Simultaneous time-resolved x-ray radiography combined with time-averaged dual-tracer fluorescence measurements enabled corrections for reabsorption of x-ray fluorescence photons for accurate, line-of-sight averaged measurements of the distribution of the gas and liquid phases originating from the atomizing nozzle. PMID:25927776

  19. Characteristic impedance of a microchannel with two immiscible microfluids

    NASA Astrophysics Data System (ADS)

    Jaramillo Raquejo, Daniela

    2014-05-01

    Consider the case of a microcapillary of radius R with two microfluidic immiscible. The micro-capillary region 0 < r < R1 is occupied by the microfluidic less dense and less viscous; while the microcapillary region R1 <0 < R is occupied by the microfluidic more dense and more viscous. Determine the characteristic impedance of the microcapillary in this case when both microfluidics are driven by the same pressure gradient as the boundary condition at the wall of the microcapillary is of the non-Newtonian slip. The Navier Stokes equation is solved for both microfluidic methods using the Laplace transform. The velocity profiles are expressed in terms of Bessel functions. Similarly, the characteristic impedance of the microcapillary is expressed by a complex formula Bessel functions. Obtain the analytical results are important for designing engineering microdevices with applications in pharmaceutical, food engineering, nanotechnology and biotechnology in general in particular. For future research it is interesting to consider the case of boundary conditions with memory effects.

  20. Immiscibility in the Nickel Ferrite-Zinc Ferrite Spinel Binary

    SciTech Connect

    SE Ziemniak; AR Gaddipati; PC Sander; SB Rice

    2006-06-21

    Immiscibility in the trevorite (NiFe{sub 2}O{sub 4}) - franklinite (ZnFe{sub 2}O{sub 4}) spinel binary is investigated by reacting 1:1:2 molar ratio mixtures of NiO, ZnO and Fe{sub 2}O{sub 3} in a molten salt solvent at temperatures in the range 400-1000 C. Single phase stability is demonstrated down to about 730 C (the estimated consolute solution temperature, T{sub cs}). A miscibility gap/solvus exists below Tcs. The solvus becomes increasingly asymmetric at lower temperatures and extrapolates to n - values = 0.15, 0.8 at 300 C. A thermodynamic analysis, which accounts for changes in configurational and magnetic ordering entropies during cation mixing, predicts solvus phase compositions at room temperature in reasonable agreement with those determined by extrapolation of experimental results. The delay between disappearance of magnetic ordering above T{sub C} = 590 C (for NiFe{sub 2}O{sub 4}) and disappearance of a miscibility gap at T{sub cs} is explained by the persistence of long-range ordering correlations in a quasi-paramagnetic region above T{sub C}.

  1. Immiscible Front Evolution in Randomly Heterogeneous Porous Media

    SciTech Connect

    A. M. Tartakovsky; S. P. Neuman; R. J. Lenhard

    2003-11-01

    The evolution of a sharp interface between two immiscible fluids in a randomly heterogeneous porous medium is investigated analytically using a stochastic moment approach. The displacing fluid is taken to be at constant saturation and to have a much larger viscosity than does the displaced fluid, which is therefore effectively static. Capillary pressure at the interface is related to porosity and permeability via the Leverett J-function. Whereas porosity is spatially uniform, permeability forms a spatially correlated random field. Displacement is governed by stochastic integro-differential equations defined over a three-dimensional domain bounded by a random interface. The equations are expanded and averaged in probability space to yield leading order recursive equations governing the ensemble mean and variance of interface position, rate of propagation and pressure gradient within the displacing fluid. Solutions are obtained for one-dimensional head- and flux-driven displacements in statistically homogeneous media and found to compare well with numerical Monte Carlo simulations. The manner in which medium heterogeneity affects the mean pressure gradient is indicative of how it impacts the stability of the mean interface. Capillary pressure at the interface is found to have a potentially important effect on its mean dynamics and stability.

  2. The immiscibility of InAlN ternary alloy.

    PubMed

    Zhao, Guijuan; Xu, Xiaoqing; Li, Huijie; Wei, Hongyuan; Han, Dongyue; Ji, Zesheng; Meng, Yulin; Wang, Lianshan; Yang, Shaoyan

    2016-01-01

    We have used two models based on the valence force field and the regular solution model to study the immiscibility of InAlN ternary alloy, and have got the spinodal and binodal curves of InAlN. Analyzing the spinodal decomposition curves, we obtain the appropriate concentration region for the epitaxial growth of the InN-AlN pseudobinary alloy. At a temperature most common for the epitaxial growth of InAlN (1000 K), the solubility of InN is about 10%. Then we introduce the mismatch strain item into the Gibbs free energy, and the effect of different substrates is taken into consideration. Considering Si, Al2O3, InN, GaN, AlN as a substrate respectively, it is found that all the five systems are stabilized with the upper critical solution temperature largely reduced. Finally, InN and GaN are potential substrates for In-rich InAlN, while AlN and GaN substrates are recommended in the Al-rich region. Si and Al2O3 may be ideal substrates for thin InAlN film. PMID:27221345

  3. Phase Change Effects on Immiscible Flow Displacements in Radial Injection

    NASA Astrophysics Data System (ADS)

    Ahmadlouydarab, Majid; Azaiez, Jalel; Chen, Zhangxin

    2014-11-01

    We report a systematic simulation of immiscible fluid-fluid displacements in radial injection in the presence of phase change. Due to the presence of two fluid-fluid interfaces in the system, a special treatment has been adopted. To track the leading interface position, two highly accurate methods including Level Set and Immersed Interface Method were used, while for locating the trailing interface an energy equation was adopted assuming the existence of a constant thin condensate layer. Dimensional analysis led to three important dimensionless groups including capillary number (Ca), Jacob number (Ja) and viscosity ratios (M) of the three fluids. Simulation results indicate significant influences of these parameters on the development of the instability and the interfacial morphology of fingers. Increasing Ca or M tends to amplify the interfacial instability, fingertip splitting, and results in longer fingers. In contrast, increasing Ja has stabilizing effects due to an increase of the thickness of the condensate layer. On the other hand at lower viscosity ratios as well as lower Ca, because of compensation effects of the phase change, both leading and trailing interfaces are found to be less unstable. Moreover accumulated condensate and oil saturation depletion curves show increasing and decreasing trends, respectively, when the Ca increases. Although viscosity ratio and Ja have similar effects on the accumulated condensate, they do not show any effect on the oil depletion saturation.

  4. Dissociation of dilute immiscible copper alloy thin films

    NASA Astrophysics Data System (ADS)

    Barmak, K.; Lucadamo, G. A.; Cabral, C.; Lavoie, C.; Harper, J. M. E.

    2000-03-01

    The dissociation behavior of dilute, immiscible Cu-alloy thin films is found to fall into three broad categories that correlate most closely with the form of the Cu-rich end of the binary alloy phase diagrams. Available thermodynamic and tracer diffusion data shed further light on alloy behavior. Eight alloying elements were selected for these studies, with five elements from groups 5 and 6, two from group 8, and one from group 11 of the periodic table. They are respectively V, Nb, Ta, Cr, Mo, Fe, Ru, and Ag. The progress of precipitation in approximately 500-nm-thick alloy films, containing 2.5-3.8 at. % solute, was followed with in situ resistance and stress measurements as well as with in situ synchrotron x-ray diffraction. In addition, texture analysis and transmission electron microscopy were used to investigate the evolution of microstructure and texture of Cu(Ta) and Cu(Ag). For all eight alloys, dissociation occurred upon heating, with the rejection of solute and evolution of microstructure often occurring in multiple steps that range over several hundred degrees between approximately 100 and 900 °C. However, in most cases, substantial reductions in resistivity of the films took place below 400 °C, at temperatures of interest to copper metallization schemes for silicon chip technology.

  5. The immiscibility of InAlN ternary alloy

    PubMed Central

    Zhao, Guijuan; Xu, Xiaoqing; Li, Huijie; Wei, Hongyuan; Han, Dongyue; Ji, Zesheng; Meng, Yulin; Wang, Lianshan; Yang, Shaoyan

    2016-01-01

    We have used two models based on the valence force field and the regular solution model to study the immiscibility of InAlN ternary alloy, and have got the spinodal and binodal curves of InAlN. Analyzing the spinodal decomposition curves, we obtain the appropriate concentration region for the epitaxial growth of the InN-AlN pseudobinary alloy. At a temperature most common for the epitaxial growth of InAlN (1000 K), the solubility of InN is about 10%. Then we introduce the mismatch strain item into the Gibbs free energy, and the effect of different substrates is taken into consideration. Considering Si, Al2O3, InN, GaN, AlN as a substrate respectively, it is found that all the five systems are stabilized with the upper critical solution temperature largely reduced. Finally, InN and GaN are potential substrates for In-rich InAlN, while AlN and GaN substrates are recommended in the Al-rich region. Si and Al2O3 may be ideal substrates for thin InAlN film. PMID:27221345

  6. Multiphase Flow of Immiscible Fluids on Unstructured Moving Meshes.

    PubMed

    Misztal, Marek K; Erleben, Kenny; Bargteil, Adam; Fursund, Jens; Christensen, Brian Bunch; Bærentzen, J Andreas; Bridson, Robert

    2013-07-01

    In this paper, we present a method for animating multiphase flow of immiscible fluids using unstructured moving meshes. Our underlying discretization is an unstructured tetrahedral mesh, the deformable simplicial complex (DSC), that moves with the flow in a Lagrangian manner. Mesh optimization operations improve element quality and avoid element inversion. In the context of multiphase flow, we guarantee that every element is occupied by a single fluid and, consequently, the interface between fluids is represented by a set of faces in the simplicial complex. This approach ensures that the underlying discretization matches the physics and avoids the additional book-keeping required in grid-based methods where multiple fluids may occupy the same cell. Our Lagrangian approach naturally leads us to adopt a finite element approach to simulation, in contrast to the finite volume approaches adopted by a majority of fluid simulation techniques that use tetrahedral meshes. We characterize fluid simulation as an optimization problem allowing for full coupling of the pressure and velocity fields and the incorporation of a second-order surface energy. We introduce a preconditioner based on the diagonal Schur complement and solve our optimization on the GPU. We provide the results of parameter studies as well as a performance analysis of our method, together with suggestions for performance optimization. PMID:23836703

  7. Multiphase flow of immiscible fluids on unstructured moving meshes.

    PubMed

    Misztal, Marek Krzysztof; Erleben, Kenny; Bargteil, Adam; Fursund, Jens; Christensen, Brian Bunch; Bærentzen, Jakob Andreas; Bridson, Robert

    2014-01-01

    In this paper, we present a method for animating multiphase flow of immiscible fluids using unstructured moving meshes. Our underlying discretization is an unstructured tetrahedral mesh, the deformable simplicial complex (DSC), that moves with the flow in a Lagrangian manner. Mesh optimization operations improve element quality and avoid element inversion. In the context of multiphase flow, we guarantee that every element is occupied by a single fluid and, consequently, the interface between fluids is represented by a set of faces in the simplicial complex. This approach ensures that the underlying discretization matches the physics and avoids the additional book-keeping required in grid-based methods where multiple fluids may occupy the same cell. Our Lagrangian approach naturally leads us to adopt a finite element approach to simulation, in contrast to the finite volume approaches adopted by a majority of fluid simulation techniques that use tetrahedral meshes. We characterize fluid simulation as an optimization problem allowing for full coupling of the pressure and velocity fields and the incorporation of a second-order surface energy. We introduce a preconditioner based on the diagonal Schur complement and solve our optimization on the GPU. We provide the results of parameter studies as well as a performance analysis of our method, together with suggestions for performance optimization. PMID:24201322

  8. Chain entanglements and fracture energy in interfaces between immiscible polymers

    NASA Astrophysics Data System (ADS)

    Silvestri, Leonardo; Brown, Hugh R.; Carrà, Stefano; Carrà, Sergio

    2003-10-01

    It is a very well-known experimental fact that the toughness of interfaces obtained by joining pairs of immiscible glassy polymers is strongly correlated to the interfacial width. Several models have been proposed in the literature to estimate the fracture energy of these interfaces, but the agreement displayed with the experimental data cannot be considered satisfactory. In this paper a new model is proposed for polymers with molecular weight higher than the critical value for the onset of entanglements. The model is based on a precise and realistic calculation of the areal density of entangled strands across the interface, that is the crucial parameter determining the toughness of the glassy joints. In this paper a new fracture regime is also introduced, called "partial crazing," corresponding to a situation where, due to the fact that some of the load-bearing strands are broken during plastic deformation, the craze can start, but not fully develop. Model predictions are then compared with a series of literature fracture energy experimental data, showing excellent agreement.

  9. The immiscibility of InAlN ternary alloy

    NASA Astrophysics Data System (ADS)

    Zhao, Guijuan; Xu, Xiaoqing; Li, Huijie; Wei, Hongyuan; Han, Dongyue; Ji, Zesheng; Meng, Yulin; Wang, Lianshan; Yang, Shaoyan

    2016-05-01

    We have used two models based on the valence force field and the regular solution model to study the immiscibility of InAlN ternary alloy, and have got the spinodal and binodal curves of InAlN. Analyzing the spinodal decomposition curves, we obtain the appropriate concentration region for the epitaxial growth of the InN-AlN pseudobinary alloy. At a temperature most common for the epitaxial growth of InAlN (1000 K), the solubility of InN is about 10%. Then we introduce the mismatch strain item into the Gibbs free energy, and the effect of different substrates is taken into consideration. Considering Si, Al2O3, InN, GaN, AlN as a substrate respectively, it is found that all the five systems are stabilized with the upper critical solution temperature largely reduced. Finally, InN and GaN are potential substrates for In-rich InAlN, while AlN and GaN substrates are recommended in the Al-rich region. Si and Al2O3 may be ideal substrates for thin InAlN film.

  10. LABORATORY INVESTIGATION OF RESIDUAL LIQUID ORGANICS FROM SPILLS, LEAKS, AND THE DISPOSAL OF HAZARDOUS WASTES IN GROUNDWATER

    EPA Science Inventory

    Organic liquids that are essentially immiscible with water migrate through the subsurface through the influence of capillary, viscous and buoyancy forces. Four experimental methods were employed. First, quantitative displacement experiments using short soil columns; second, add...

  11. LABORATORY INVESTIGATION OF RESIDUAL LIQUID ORGANICS FROM SPILLS, LEAKS, AND THE DISPOSAL OF HAZARDOUS WASTES IN GROUNDWATER

    EPA Science Inventory

    Organic liquids that are essentially immiscible with water migrate through the subsurface through the influence of capillary, viscous and buoyancy forces. our experimental methods were employed. irst, quantitative displacement experiments using short soil columns; second, additio...

  12. Ion spatial distributions at the liquid-vapor interface of aqueous potassium fluoride solutions

    SciTech Connect

    Brown, M A; D'Auria, R; Kuo, I W; Krisch, M J; Starr, D E; Bluhm, H; Tobias, D J; Hemminger, J C

    2008-04-23

    X-ray photoemission spectroscopy operating under ambient pressure conditions is used to probe ion distributions throughout the interfacial region of a free-flowing aqueous liquid micro-jet of 6 M potassium fluoride. Varying the energy of the ejected photoelectrons by carrying out experiments as a function of x-ray wavelength measures the composition of the aqueous-vapor interfacial region at various depths. The F{sup -} to K{sup +} atomic ratio is equal to unity throughout the interfacial region to a depth of 2 nm. The experimental ion profiles are compared with the results of a classical molecular dynamics simulation of a 6 M aqueous KF solution employing polarizable potentials. The experimental results are in qualitative agreement with the simulations when integrated over an exponentially decaying probe depth characteristic of an APPES experiment. First principles molecular dynamics simulations have been used to calculate the potential of mean force for moving a fluoride anion across the air-water interface. The results show that the fluoride anion is repelled from the interface, and this is consistent with the depletion of F{sup -} at the interface revealed by the APPES experiment and polarizable force field-based molecular dynamics simulation. Together, the APPES and MD simulation data provide a detailed description of the aqueous-vapor interface of alkali fluoride systems. This work offers the first direct observation of the ion distribution at a potassium fluoride aqueous solution interface. The current experimental results are compared to those previously obtained for saturated solutions of KBr and KI to underscore the strong difference in surface propensity between soft/large and hard/small halide ions in aqueous solution.

  13. Vortex distribution and mixed convection of liquid flow across micro-cylinders in a rectangular channel

    NASA Astrophysics Data System (ADS)

    Guan, Ning; Luan, Tao; Liu, Zhi-Gang; Zhang, Cheng-Wu; Jiang, Guilin

    2016-03-01

    The impacts of heat flux ( q = 10, 15, 20 W/cm2), cylinder diameter ( D = 300, 600, 3000 μm), aspect ratio AR ( H/D = 1, 2, 4) and block ratio BR ( W/D = 2, 4, 16) on vortex distribution and mixed convection of liquid flow across single micro-cylinder and micro-cylinder-groups (3 × 3 cylinders) were numerically investigated. The separation angles, recirculation lengths ( Lv) and Nusselt numbers were calculated with Reynolds number ranging from 10 to 60. For the single micro-cylinder, the separation angle and the value of Lv/D both became large with the increase of heat flux, and the profiles of Lv/D versus z/H were asymmetrical, which is different from the cylinders with dimensions of millimeter-level. The discrepancies of Lv/D on the same plane of micro-cylinders with different AR in the region near end-walls were larger than those near the symmetry wall. For the 3 × 3 micro-cylinder-groups, the value of Lv/D was related to the location along the axial direction, while the separation angle became small along the flowing direction. The mixed heat transfer in rectangular channel with micro-cylinders could be enhanced by changing the dimensions of the cylinders and the channel.

  14. Distribution of single-walled carbon nanotubes in pyrene containing liquid crystalline asymmetric zinc phthalocyanine matrix.

    PubMed

    Tuncel, Sinem; Kaya, Esra Nur; Durmuş, Mahmut; Basova, Tamara; Gürek, Ayşe Gül; Ahsen, Vefa; Banimuslem, Hikmat; Hassan, Aseel

    2014-03-28

    A novel pyrene containing asymmetric Zn(II) phthalocyanine (AB3 type) was synthesized and characterized by various spectroscopic techniques as well as elemental analysis. A symmetric polyoxyethylene substituted Zn(II) phthalocyanine (B4 type) derivative was also prepared in order to compare the properties and determine the effect of the pyrene group on the phthalocyanine molecule. Composites of synthesized zinc(II) phthalocyanine-single wall carbon nanotubes (ZnPc-SWCNTs) containing 1 and 2 wt% carbon nanotubes were prepared by mixing these two components in dichloromethane followed by removal of the solvent and drying under vacuum. The liquid crystalline properties of the pure compounds and their composites were investigated in comparison with symmetric polyoxyethylene substituted Zn(II) phthalocyanine (B4 type) by using polarized optical microscopy, differential scanning calorimetry and X-ray diffraction analysis. The distribution of the SWCNTs in the ordered matrix of the columnar mesophase of these derivatives was studied by the method of polarized Raman spectroscopy and scanning electron microscopy (SEM). It was shown that the nature of the mesophases was not altered in these composites. The I(V) dependencies for the films deposited onto interdigitated electrodes were measured and it was shown that the lateral conductivity tends to increase with increasing SWCNT concentration. PMID:24468739

  15. Specific distributions of anions and cations of an ionic liquid through confinement between graphene sheets.

    PubMed

    Alibalazadeh, Mahtab; Foroutan, Masumeh

    2015-07-01

    This work was aimed to investigate the behavior, morphology, structure, and dynamical properties of pure ionic liquid (IL) 1-ethyl-3-methylimidazolium tetrafluoroborate ([emim][BF4]) confined between two parallel and flat graphene sheets at different interwall distances, H. Thus, molecular dynamic (MD) simulations were performed for different interwall distances including (10, 14, 16, 20, 23, and 28) Å at seven temperatures from 278 to 308 K. These results showed that the distribution and orientation of cations and anions on the graphene sheets depended on H. At the shortest H, a dense monolayer of the anions and cations was formed between two graphene sheets. The number of these layers increased as H increased. The potential energy diagram as a function of H demonstrated a minimum potential energy at H = 16 Å. Also, there was a minimum overlap between the density profiles of the cations and anions at H = 16 Å. Diffusion coefficients of the cations and anions increased as temperature and H increased. Moreover, slope of the plot of the diffusion coefficients of the cations and anions versus H significantly changed at H = 16 Å. Orientation functions revealed that most of the cations oriented parallel to the graphene sheets. PMID:26048248

  16. Experimental development of processes to produce homogenized alloys of immiscible metals, phase 3

    NASA Technical Reports Server (NTRS)

    Reger, J. L.

    1976-01-01

    An experimental drop tower package was designed and built for use in a drop tower. This effort consisted of a thermal analysis, container/heater fabrication, and assembly of an expulsion device for rapid quenching of heated specimens during low gravity conditions. Six gallium bismuth specimens with compositions in the immiscibility region (50 a/o of each element) were processed in the experimental package: four during low gravity conditions and two under a one gravity environment. One of the one gravity processed specimens did not have telemetry data and was subsequently deleted for analysis since the processing conditions were not known. Metallurgical, Hall effect, resistivity, and superconductivity examinations were performed on the five specimens. Examination of the specimens showed that the gallium was dispersed in the bismuth. The low gravity processed specimens showed a relatively uniform distribution of gallium, with particle sizes of 1 micrometer or less, in contrast to the one gravity control specimen. Comparison of the cooling rates of the dropped specimens versus microstructure indicated that low cooling rates are more desirable.

  17. Soot and liquid-phase fuel distributions in a newly designed optically accessible D.I. diesel engine

    SciTech Connect

    Dec, J.E.; Espey, C.

    1993-10-01

    Two-dimensional (2-D) laser-sheet imaging has been used to examine the soot and liquid-phase fuel distributions in a newly designed, optically accessible, direct-injection Diesel engine of the heavy-duty size class. The design of this engine preserves the intake port geometry and basic dimensions of a Cummins N-series production engine. It also includes several unique features to provide considerable optical access. Liquid-phase fuel and soot distribution studies were conducted at a medium speed (1,200 rpm) using a Cummins closed-nozzle fuel injector. The scattering was used to obtain planar images of the liquid-phase fuel distribution. These images show that the leading edge of the liquid-phase portion of the fuel jet reaches a maximum length of 24 mm, which is about half the combustion bowl radius for this engine. Beyond this point virtually all the fuel has vaporized. Soot distribution measurements were made at a high load condition using three imaging diagnostics: natural flame luminosity, 2-D laser-induced incandescence, and 2-D elastic scattering. This investigation showed that the soot distribution in the combusting fuel jet develops through three stages. First, just after the onset of luminous combustion, soot particles are small and nearly uniformly distributed throughout the luminous region of the fuel jet. Second, after about 2 crank angle degrees a pattern develops of a higher soot concentration of larger sized particles in the head vortex region of the jet and a lower soot concentration of smaller sized particles upstream toward the injector. Third, after fuel injection ends, both the soot concentration and soot particle size increase rapidly in the upstream portion of the fuel jet.

  18. Predicting apparent slip at liquid-liquid interfaces without an interface slip condition

    NASA Astrophysics Data System (ADS)

    Poesio, Pietro; Damone, Angelo; Matar, Omar

    2015-11-01

    We show that if we include a density-dependent viscosity into the Navier-Stokes equations then we can describe, naturally, the velocity profile in the interfacial region, as we transition from one fluid to another. This requires knowledge of the density distribution (for instance, via Molecular Dynamics [MD] simulations, a diffuse-interface approach, or Density Functional Theory) everywhere in the fluids, even at liquid-liquid interfaces where regions of rapid density variations are possible due to molecular interactions. We therefore do not need an artificial interface condition that describes the apparent velocity slip. If the results are compared with the computations obtained from MD simulations, we find an almost perfect agreement. The main contribution of this work is to provide a simple way to account for the apparent slip at liquid-liquid interfaces without relying upon an additional boundary condition, which needs to be calculated separately using MD simulations. Examples are provided involving two immiscible fluids of varying average density ratios, undergoing simple Couette and Poisseuille flows. MIUR through PRIN2012-NANOBridge; Royal Society International Exchange Scheme (IE141486).

  19. Experimentally Determined Interfacial Area Between Immiscible Fluids in Porous Media

    SciTech Connect

    Crandall, Dustin; Niessner, J; Hassanizadeh, S.M; Smith, Duane

    2008-01-01

    When multiple fluids flow through a porous medium, the interaction between the fluid interfaces can be of great importance. While this is widely recognized in practical applications, numerical models often disregard interactios between discrete fluid phases due to the computational complexity. And rightly so, for this level of detail is well beyond most extended Darcy Law relationships. A new model of two-phase flow including the interfacial area has been proposed by Hassarizadeh and Gray based upon thermodynamic principles. A version of this general equation set has been implemented by Nessner and Hassarizadeh. Many of the interfacial parameters required by this equation set have never been determined from experiments. The work presented here is a description of how the interfacial area, capillary pressure, interfacial velocity and interfacial permeability from two-phase flow experiments in porous media experiments can be used to determine the required parameters. This work, while on-going, has shown the possibility of digitizing images within translucent porous media and identifying the location and behavior of interfaces under dynamic conditions. Using the described methods experimentally derived interfacial functions to be used in larger scale simulations are currently being developed. In summary, the following conclusions can be drawn: (1) by mapping a pore-throat geometry onto an image of immiscible fluid flow, the saturation of fluids and the individual interfaces between the fluids can be identified; (2) the resulting saturation profiles of the low velocity drainage flows used in this study are well described by an invasion percolation fractal scaling; (3) the interfacial area between fluids has been observed to increase in a linear fashion during the initial invasion of the non-wetting fluid; and (4) the average capillary pressure within the entire cell and representative elemental volumes were observed to plateau after a small portion of the volume was

  20. Physical formulation and numerical algorithm for simulating N immiscible incompressible fluids involving general order parameters

    SciTech Connect

    Dong, S.

    2015-02-15

    We present a family of physical formulations, and a numerical algorithm, based on a class of general order parameters for simulating the motion of a mixture of N (N⩾2) immiscible incompressible fluids with given densities, dynamic viscosities, and pairwise surface tensions. The N-phase formulations stem from a phase field model we developed in a recent work based on the conservations of mass/momentum, and the second law of thermodynamics. The introduction of general order parameters leads to an extremely strongly-coupled system of (N−1) phase field equations. On the other hand, the general form enables one to compute the N-phase mixing energy density coefficients in an explicit fashion in terms of the pairwise surface tensions. We show that the increased complexity in the form of the phase field equations associated with general order parameters in actuality does not cause essential computational difficulties. Our numerical algorithm reformulates the (N−1) strongly-coupled phase field equations for general order parameters into 2(N−1) Helmholtz-type equations that are completely de-coupled from one another. This leads to a computational complexity comparable to that for the simplified phase field equations associated with certain special choice of the order parameters. We demonstrate the capabilities of the method developed herein using several test problems involving multiple fluid phases and large contrasts in densities and viscosities among the multitude of fluids. In particular, by comparing simulation results with the Langmuir–de Gennes theory of floating liquid lenses we show that the method using general order parameters produces physically accurate results for multiple fluid phases.

  1. A note on the visualization of wetting film structures and a nonwetting immiscible fluid in a pore network micromodel using a solvatochromic dye

    SciTech Connect

    Grate, Jay W.; Zhang, Changyong; Wietsma, Thomas W.; Warner, Marvin G.; Anheier, Norman C.; Bernacki, Bruce E.; Orr, Galya; Oostrom, Martinus

    2010-11-23

    Nile Red is demonstrated as a single dye whose solvatochromism enables selective visualization of two immiscible liquid fluids in a micromodel containing a homogeneous array of pillars creating a porous network. Nile Red dissolves in and partitions between hexadecane as a nonwetting fluid and PEG200 as a hydrophilic fluid that wets the silicon oxide surfaces in the micromodel. Both the absorption spectra and fluorescence emission spectra are sensitive to the solvent environment, such that the two phases can be distinguished by the observed color or the fluorescence emission band. Bright field, hyperspectral, epifluorescence, and confocal fluorescence methods were used to image the micromodel after displacing PEG200 in the model with hexadecane. The use of Nile Red with these imaging methods facilitates visualization of phase identity at specific locations; the interfaces between the two immiscible liquid phases; wetting behavior of the wetting phase within the porous structure; and retention of the wetting phase as thin films around pillars and as bridges across the pore throats. The pillars and wetting phase bridges create a network of obstacles defining a tortuous preferential flow path for the nonwetting phase.

  2. Interplay Between a Strong Memory Effect of Crystallization and Liquid-Liquid Phase Separation in Melts of Broadly Distributed Ethylene 1-Alkene Copolymers

    NASA Astrophysics Data System (ADS)

    Alamo, Rufina G.; Mamun, Al; Chen, Xuejian

    2015-03-01

    Ethylene-1-alkene copolymers with a broad, bimodal comonomer distribution display acceleration and retardation of the crystallization rate when cooling from a range of melt temperatures where narrow copolymers show a continuous acceleration of the rate. The acceleration of the rate is observed in a range of melt temperatures between 165 and 150 °C, and is due to a strong memory effect of crystallization above their equilibrium melting point. The retardation or inversion of the rate, observed in a range of 150 to 123 °C, demarcates the onset of a self-seed assisted liquid-liquid phase separation (LLPS) between comonomer-rich and comonomer poor molecules. The interplay between number of self-seeds at the initial melt temperature and chain diffusion during LLPS causes a decrease in the crystallization rate with decreasing melt temperature. When crystallites remain in the melt at temperatures <123 °C, the crystallization rate again accelerates quickly. The crystallization rates were studied by DSC, and the effect in nucleation density and in overall crystalline morphology of crystallizations from one phase or two liquid phases was followed by polarized optical microscopy and transmission electron microscopy.

  3. Progress on the MICE Liquid Absorber Cooling and CryogenicDistribution System

    SciTech Connect

    Green, M.A.; Baynham, E.; Bradshaw, T.; Drumm, P.; Ivanyushenkov,Y.; Ishimoto, S.; Cummings, M.A.C.; Lau, W.W.; Yang, S.Q.

    2005-05-13

    This report describes the progress made on the design of the cryogenic cooling system for the liquid absorber for the international Muon Ionization Cooling Experiment (MICE). The absorber consists of a 20.7-liter vessel that contains liquid hydrogen (1.48 kg at 20.3 K) or liquid helium (2.59 kg at 4.2 K). The liquid cryogen vessel is located within the warm bore of the focusing magnet for the MICE. The purpose of the magnet is to provide a low beam beta region within the absorber. For safety reasons, the vacuum vessel for the hydrogen absorber is separated from the vacuum vessel for the superconducting magnet and the vacuum that surrounds the RF cavities or the detector. The absorber thin windows separate the liquid in the absorber from the absorber vacuum. The absorber vacuum vessel also has thin windows that separate the absorber vacuum space from adjacent vacuum spaces. Because the muon beam in MICE is of low intensity, there is no beam heating in the absorber. The absorber can use a single 4 K cooler to cool either liquid helium or liquid hydrogen within the absorber.

  4. The simulation of temperature distribution and relative humidity with liquid concentration of 50% using computational fluid dynamics

    NASA Astrophysics Data System (ADS)

    Yohana, Eflita; Yulianto, Mohamad Endy; Kwang-Hwang, Choi; Putro, Bondantio; Yohanes Aditya W., A.

    2015-12-01

    The study of humidity distribution simulation inside a room has been widely conducted by using computational fluid dynamics (CFD). Here, the simulation was done by employing inputs in the experiment of air humidity reduction in a sample house. Liquid dessicant CaCl2was used in this study to absorb humidity in the air, so that the enormity of humidity reduction occured during the experiment could be obtained.The experiment was conducted in the morning at 8 with liquid desiccant concentration of 50%, nozzle dimension of 0.2 mms attached in dehumidifier, and the debit of air which entered the sample house was 2.35 m3/min. Both in inlet and outlet sides of the room, a DHT 11 censor was installed and used to note changes in humidity and temperature during the experiment. In normal condition without turning on the dehumidifier, the censor noted that the average temperature inside the room was 28°C and RH of 65%.The experiment result showed that the relative humidity inside a sample house was decreasing up to 52% in inlet position. Further, through the results obtained from CFD simulation, the temperature distribution and relative humidity inside the sample house could be seen. It showed that the concentration of liquid desiccant of 50% experienced a decrease while the relative humidity distribution was considerably good since the average RH was 55% followed by the increase in air temperature of 29.2° C inside the sample house.

  5. A Microfluidic Platform for the Rapid Determination of Distribution Coefficients by Gravity-Assisted Droplet-Based Liquid-Liquid Extraction.

    PubMed

    Poulsen, Carl Esben; Wootton, Robert C R; Wolff, Anders; deMello, Andrew J; Elvira, Katherine S

    2015-06-16

    The determination of pharmacokinetic properties of drugs, such as the distribution coefficient (D) is a crucial measurement in pharmaceutical research. Surprisingly, the conventional (gold standard) technique used for D measurements, the shake-flask method, is antiquated and unsuitable for the testing of valuable and scarce drug candidates. Herein, we present a simple microfluidic platform for the determination of distribution coefficients using droplet-based liquid-liquid extraction. For simplicity, this platform makes use of gravity to enable phase separation for analysis and is 48 times faster and uses 99% less reagents than performing an equivalent measurement using the shake-flask method. Furthermore, the D measurements achieved in our platform are in good agreement with literature values measured using traditional shake-flask techniques. Since D is affected by volume ratios, we use the apparent acid dissociation constant, pK', as a proxy for intersystem comparison. Our platform determines a pK' value of 7.24 ± 0.15, compared to 7.25 ± 0.58 for the shake-flask method in our hands and 7.21 for the shake-flask method in the literature. Devices are fabricated using injection molding, the batchwise fabrication time is <2 min per device (at a cost of $1 U.S. per device), and the interdevice reproducibility is high. PMID:25984969

  6. Synthesis of new metastable nanoalloys of immiscible metals with a pulse laser technique

    PubMed Central

    Swiatkowska-Warkocka, Zaneta; Pyatenko, Alexander; Krok, Franciszek; Jany, Benedykt R.; Marszalek, Marta

    2015-01-01

    The generation of nanoalloys of immiscible metals is still a challenge using conventional methods. However, because these materials are currently attracting much attention, alternative methods are needed. In this article, we demonstrate a simple but powerful strategy for the generation of a new metastable alloy of immiscible metals. Au1−xNix 3D structures with 56 at% of nickel in gold were successfully manufactured by the pulsed laser irradiation of colloidal nanoparticles. This technology can be used for preparing different metastable alloys of immiscible metals. We hypothesise that this technique leads to the formation of alloy particles through the agglomerations of nanoparticles, very fast heating, and fast cooling/solidification. Thus, we expect that our approach will be applicable to a wide range of inorganic solids, yielding even new metastable solids that fail to be stable in the bulk systems, and therefore do not exist in Nature. PMID:25952016

  7. Distributed temperature monitoring for liquid sodium leakage detection using OFDR-based Rayleigh backscattering

    NASA Astrophysics Data System (ADS)

    Boldyreva, E.; Cotillard, R.; Laffont, G.; Ferdinand, P.; Cambet, D.; Jeannot, J.-P.; Charvet, P.; Albaladéjo, S.; Rodriguez, G.

    2014-05-01

    For the first time, a gold coated single mode optical fiber has been used to detect a liquid sodium leakage on a pipe of secondary circuit pipe mock-up of nuclear fast reactor (Gen IV) by means of Optical Frequency Domain Reflectometry-based on Rayleigh backscattering. During 150 min of the experiment we were able to detect and monitor the evolution of a liquid sodium leakage on the surface of the pipe.

  8. Immiscible experiments on the Rayleigh-Taylor instability using simultaneous particle image velocimetry and planar laser induced fluorescence concentration measurements

    NASA Astrophysics Data System (ADS)

    Mokler, Matthew; Jacobs, Jeffrey

    2014-11-01

    Incompressible Rayleigh-Taylor instability experiments are presented in which two stratified liquids having Atwood number of 0.2 are accelerated in a vertical linear induction motor driven drop tower. A test sled having only vertical freedom of motion contains the experiment tank and visualization equipment. The sled is positioned at the top of the tower within the linear induction motors and accelerated downward causing the initially stable interface to be unstable and allowing the Rayleigh-Taylor instability to develop. Forced and unforced experiments are conducted using an immiscible liquid combination. Forced initial perturbations are produced by vertically oscillating the test sled prior to the start of acceleration. The interface is visualized using a 445 nm laser light source that illuminates a fluorescent dye mixed in one of the fluids and aluminum oxide particles dispersed in both fluids. The laser beam is synchronously swept across the fluorescent fluid, at the frame rate of the camera, exposing a single plane of the interface. The resulting images are recorded using a monochromatic high speed video camera. Time dependent velocity and density fields are obtained from the recorded images allowing for 2D full field measurements of turbulent kinetic energy and turbulent mass transport.

  9. The influence of porous medium characteristics and measurement scale on pore-scale distributions of residual nonaqueous-phase liquids

    NASA Astrophysics Data System (ADS)

    Mayer, Alex S.; Miller, Cass T.

    1992-11-01

    A series of experiments was performed to characterize the morphologic distribution of nonaqueous-phase liquids (NAPL's) at residual saturation, as a function of porous medium size. Morphologic characterization of NAPL distributions was accomplished using a novel in situ polymerization technique. The porous medium consisted of glass beads. Blob length, volume and shape characteristics were determined for each experiment, and pore size distributions were determined through capillary pressure-saturation experiments. Both the blob lenght and pore size distributions were fitted to a van Genuchten function. Both blob lenght and pressure-saturation data could be scaled with the same averaged porous medium characteristics. The blob length distributions were found to be wider than the pore size distributions. Estimates of representative elementary volumes (REV's) were generated from statistical analysis using a van Genuchten cumulative frequency distribution function for blob lenght and an empirical function for blob volume as a function of blob length. Simulations were also performed using a Monte Carlo method. The size of the REV needed for a given level of prediction of the residual saturation level was found to increase as a function of mean particle volume for the similar used in this study. Extrapolation of the REV analysis suggests that the size of an REV will increase rapidly as uniformity of the medium decreases. If this extrapolation holds true, significant uncertainty would exist in most determination of residual saturation for poorly sorted media that have been reported to date.

  10. Tomographic analysis of neutron and gamma pulse shape distributions from liquid scintillation detectors at Joint European Torus

    SciTech Connect

    Giacomelli, L.; Conroy, S.; Gorini, G.; Horton, L.; Murari, A.; Popovichev, S.; Syme, D. B.

    2014-02-15

    The Joint European Torus (JET, Culham, UK) is the largest tokamak in the world devoted to nuclear fusion experiments of magnetic confined Deuterium (D)/Deuterium-Tritium (DT) plasmas. Neutrons produced in these plasmas are measured using various types of neutron detectors and spectrometers. Two of these instruments on JET make use of organic liquid scintillator detectors. The neutron emission profile monitor implements 19 liquid scintillation counters to detect the 2.45 MeV neutron emission from D plasmas. A new compact neutron spectrometer is operational at JET since 2010 to measure the neutron energy spectra from both D and DT plasmas. Liquid scintillation detectors are sensitive to both neutron and gamma radiation but give light responses of different decay time such that pulse shape discrimination techniques can be applied to identify the neutron contribution of interest from the data. The most common technique consists of integrating the radiation pulse shapes within different ranges of their rising and/or trailing edges. In this article, a step forward in this type of analysis is presented. The method applies a tomographic analysis of the 3-dimensional neutron and gamma pulse shape and pulse height distribution data obtained from liquid scintillation detectors such that n/γ discrimination can be improved to lower energies and additional information can be gained on neutron contributions to the gamma events and vice versa.

  11. Tomographic analysis of neutron and gamma pulse shape distributions from liquid scintillation detectors at Joint European Torus

    NASA Astrophysics Data System (ADS)

    Giacomelli, L.; Conroy, S.; Gorini, G.; Horton, L.; Murari, A.; Popovichev, S.; Syme, D. B.

    2014-02-01

    The Joint European Torus (JET, Culham, UK) is the largest tokamak in the world devoted to nuclear fusion experiments of magnetic confined Deuterium (D)/Deuterium-Tritium (DT) plasmas. Neutrons produced in these plasmas are measured using various types of neutron detectors and spectrometers. Two of these instruments on JET make use of organic liquid scintillator detectors. The neutron emission profile monitor implements 19 liquid scintillation counters to detect the 2.45 MeV neutron emission from D plasmas. A new compact neutron spectrometer is operational at JET since 2010 to measure the neutron energy spectra from both D and DT plasmas. Liquid scintillation detectors are sensitive to both neutron and gamma radiation but give light responses of different decay time such that pulse shape discrimination techniques can be applied to identify the neutron contribution of interest from the data. The most common technique consists of integrating the radiation pulse shapes within different ranges of their rising and/or trailing edges. In this article, a step forward in this type of analysis is presented. The method applies a tomographic analysis of the 3-dimensional neutron and gamma pulse shape and pulse height distribution data obtained from liquid scintillation detectors such that n/γ discrimination can be improved to lower energies and additional information can be gained on neutron contributions to the gamma events and vice versa.

  12. Droplet Impact onto an Immiscible, Floating Oil Layer: Splash Behavior and Droplet Sizes

    NASA Astrophysics Data System (ADS)

    Murphy, David; Li, Cheng; D'Albignac, Vincent; Morra, David; Katz, Joseph

    2015-11-01

    The high speed impact of a raindrop on a fluid surface at Wed = ρ u2d/ σ>2000 affects environmental processes like marine aerosol production. High speed imaging shows that a floating immiscible oil layer, such as a crude oil slick, modifies the splash behavior. Tests performed for a wide range of layer thicknesses (h), viscosities, and surface and interfacial tensions facilitate behavioral categorization in terms of Weh =ρh u2h/σh and ReFrh =ρd u3d/μhgh, where h and d subscripts refer to layer and droplet properties, respectively. Included are multi-layer/level crowns, and due to the high Oh = μ /(ρσ d)1/2 of oil, formation of an intact ejecta sheet within 50 μs after impact, which subsequently ruptures to form aerosolized oil droplets. High speed holographic microscopy provides the size and spatial distributions of airborne droplets, which are bimodal with peaks at 50 and 225 μm. Small droplets (50 μm) are ejected primarily at shallow angles and remain at low elevation by microligament breakup within the first 50 μs of impact. Larger droplets (225 μm) are ejected at a steeper angle and produced later by breakup of larger ligaments protruding vertically from the splash crown. Small droplet frequency at high elevation increases when crude oil is introduced, mostly as satellite droplets resulting from the large ligament breakup. Funding provided by the Gulf of Mexico Research Initiative.

  13. Generation of micro- and nano-droplets containing immiscible solutions in view of optical studies

    NASA Astrophysics Data System (ADS)

    Nastasa, V.; Karapantsios, T.; Samaras, K.; Dafnopatidou, E.; Pradines, V.; Miller, R.; Pascu, M. L.

    2010-08-01

    The multiple resistances to treatment, developed by bacteria and malignant tumors require finding alternatives to the existing medicines and treatment procedures. One of them is strengthening the effects of cytostatics by improving the delivery method. Such a method is represented by the use of medicines as micro/nano-droplets. This method can reduce the substance consumption by generating drug micro-droplets incorporated in substances that can favour a faster localization, than the classical mode of medicine administration, to the tumor tissues. This paper contains the results concerning the generation and study of micro/nano-droplets and the generation of micro-droplets with an inner core (medicine) and a thin layer covering it. We have measured the surface tension at water/air interface and water/oil interface for a medicine (Vancomycin) and we have generated and measured droplets of medicine containing a layer of Vitamin A by using a double capillary system. The micro/nano-droplets may be produced by mixing of two immiscible solutions in particular conditions (high rotating speed and/or high pressure difference). For this we have studied the generation of emulsions of vitamin A diluted in sunflower oil and a solution of a surfactant Tween 80 in distilled water. The concentration of surfactant in water was typically 4*10-5M. We have studied in a batch stirred tank system the dependence of the droplet dimensions in emulsion, function of the mixing rotation speed, agitation time and components ratio. The droplet diameters were measured using a Malvern light scattering instrument type Mastersizer Hydro 2000M. We have obtained droplets with diameters smaller than 100 nm; the diameters distribution exhibited a peak at 65 nm.

  14. Distribution of aquifers, liquid-waste impoundments, and municipal water-supply sources, Massachusetts

    USGS Publications Warehouse

    Delaney, David F.; Maevsky, Anthony

    1980-01-01

    Impoundments of liquid waste are potential sources of ground-water contamination in Massachusetts. The map report, at a scale of 1 inch equals 4 miles, shows the idstribution of aquifers and the locations of municipal water-supply sources and known liquid-waste impoundments. Ground water, an important source of municipal water supply, is produced from shallow sand and gravel aquifers that are generally unconfined, less than 200 feet thick, and yield less than 2,000 gallons per minute to individual wells. These aquifers commonly occupy lowlands and stream valleys and are most extensive in eastern Massachusetts. Surface impoundments of liquid waste are commonly located over these aquifers. These impoundments may leak and allow waste to infiltrate underlying aquifers and alter their water quality. (USGS)

  15. The use of rheology to elucidate the granulation mechanisms of a miscible and immiscible system during continuous twin-screw melt granulation.

    PubMed

    Monteyne, Tinne; Heeze, Liza; Mortier, Séverine Thérèse F C; Oldörp, Klaus; Nopens, Ingmar; Remon, Jean-Paul; Vervaet, Chris; De Beer, Thomas

    2016-08-20

    Twin-screw hot melt granulation (TS HMG) is a valuable, but still unexplored alternative to granulate temperature and moisture sensitive drugs in a continuous way. Recently, the material behavior of an immiscible drug-binder blend during TS HMG was unraveled by using a rheometer and differential scanning calorimetry (DSC). Additionally, vibrational spectroscopic techniques proved the link between TS HMG and rheology since equal interactions at molecular level did occur in both processes. This allowed to use a rheometer to gain knowledge of the material behavior during hot melt processing of an immiscible drug-binder blend. However, miscibility of a drug-binder formulation and drug-binder interactions appear to influence the rheological properties and, hence conceivably also the granulation mechanism. The aim of this research was to examine if the TS HMG process of a miscible formulation system is comparable with the mechanism of an immiscible system and to evaluate whether rheology still serves as a useful tool to understand and optimize the hot melt granulation (HMG) process. The executed research (thermal analysis, rheological parameters and spectroscopic data) demonstrated the occurrence of a high and broad tan(δ) curve without a loss peak during the rheological temperature ramp which implies a higher material deformability without movement of the softened single polymer chains. Spectroscopic analysis revealed drug-polymer interactions which constrain the polymer to flow independently. As a result, the binder distribution step, which generally follows the immersion step, was hindered. This insight assisted the understanding of the granule properties. Inhomogeneous granules were produced due to large initial nuclei or adhesion of multiple smaller nuclei. Consequently, a higher granulation temperature was required in order to get the binder more homogeneously distributed within the granules. PMID:27374203

  16. Measurement of residence time distribution of liquid phase in an industrial-scale continuous pulp digester using radiotracer technique.

    PubMed

    Sheoran, Meenakshi; Goswami, Sunil; Pant, Harish J; Biswal, Jayashree; Sharma, Vijay K; Chandra, Avinash; Bhunia, Haripada; Bajpai, Pramod K; Rao, S Madhukar; Dash, A

    2016-05-01

    A series of radiotracer experiments was carried out to measure residence time distribution (RTD) of liquid phase (alkali) in an industrial-scale continuous pulp digester in a paper industry in India. Bromine-82 as ammonium bromide was used as a radiotracer. Experiments were carried out at different biomass and white liquor flow rates. The measured RTD data were treated and mean residence times in individual digester tubes as well in the whole digester were determined. The RTD was also analyzed to identify flow abnormalities and investigate flow dynamics of the liquid phase in the pulp digester. Flow channeling was observed in the first section (tube 1) of the digester. Both axial dispersion and tanks-in-series with backmixing models preceded with a plug flow component were used to simulate the measured RTD and quantify the degree of axial mixing. Based on the study, optimum conditions for operating the digester were proposed. PMID:26896681

  17. A polymer microgel at a liquid-liquid interface: theory vs. computer simulations.

    PubMed

    Rumyantsev, Artem M; Gumerov, Rustam A; Potemkin, Igor I

    2016-08-10

    We propose a mean-field theory and dissipative particle dynamics (DPD) simulations of swelling and collapse of a polymer microgel adsorbed at the interface of two immiscible liquids (A and B). The microgel reveals surface activity and lowers A-B interfacial tension. Attempting to occupy as large an interfacial area as possible, the microgel undergoes anisotropic deformation and adopts a flattened shape. Spreading over the interface is restricted by polymer subchain elasticity. The equilibrium shape of the microgel at the interface depends on its size. Small microgels are shown to be more oblate than the larger microgels. Increasing microgel cross-link density results in stronger reduction of the surface tension and weaker flattening. As the degree of immiscibility of A and B liquids increases, the microgel volume changes in a non-monotonous fashion: the microgel contraction at moderate immiscibility of A and B liquids is followed by its swelling at high incompatibility of the liquids. The segregation regime of the liquids within and outside the microgel is different. Being segregated outside the microgel, the liquids can be fully (homogeneously) mixed or weakly segregated within it. The density profiles of the liquids and the polymer were plotted under different conditions. The theoretical and the DPD simulation results are in good agreement. We hope that our findings will be useful for the design of stimuli responsive emulsions, which are stabilized by the microgel particles, as well as for their practical applications, for instance, in biocatalysis. PMID:27460037

  18. DISTRIBUTION OF TRACE ELEMENT EMISIONS FROM THE LIQUID INJECTION INCINERATOR COMBUSTION RESEARCH FACILITY

    EPA Science Inventory

    A series of tests was conducted at EPA's Combustion Research Facility (CRF) to investigate the fate of volatile trace elements in liquid injection hazardous waste incineration. In these tests, arsenic in the form of arsenic trioxide and antimony in the form of antimony trichlorid...

  19. Morphological development of polypropylene in immiscible blends with cellulose acetate butyrate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Isotactic polypropylenes (iPP) with different melt flow indexes were melt blended with cellulose acetate butyrate (CAB) and then prepared into microspheres or nanofibers following a novel process of producing well dispersed CAB/iPP immiscible blends and subsequent removal of the CAB matrix. The morp...

  20. Morphology Evolution of Polypropylene in Immiscible Polymer Blends for Fabrication of Nanofibers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Immiscible blends of cellulose acetate butyrate (CAB) and isotactic polypropylenes (iPPs) with different melting index were extruded through a two-strand rod die. The extrudates were hot-drawn at the die exit at different draw ratios by controlling the drawing speed. The morphologies of iPP fibers e...

  1. BEHAVIOR OF DENSE, IMMISCIBLE SOLVENTS IN FRACTURED CLAY-RICH SOILS

    EPA Science Inventory

    A series of laboratory-scale experiments on the behavior of dense, immiscible solvents (commonly referred to as DNAPL's) in large diameter, undisturbed columns of fractured clay till and highly weathered and fractured shale saprolite are proposed. The lab studies will focus on th...

  2. Electrically tunable liquid crystal laser using a nanoimprinted indium-tin-oxide electrode as a distributed feedback resonator.

    PubMed

    Yoon, Kyung Won; Ha, Na Young

    2016-01-11

    We demonstrated electrical tunability of a liquid crystal (LC) laser using a nanoimprinted indium-tin-oxide (ITO) film as a distributed feedback (DFB) resonator, a transparent electrode, and an alignment layer for LCs. From the field-induced reorientation of LCs and changes in effective refractive indices of guided laser modes, lasing emission is tuned by 6 nm at low applied voltage of 8.0 V. This is because the LC laser with the nanoimprinted ITO electrode has no additional insulating layers for lasing performance. The present system is based on the functional electrode and its active control provides various applications and advances in laser technology. PMID:26832281

  3. Effect of an electric field on the orientation of a liquid crystal in a cell with a nonuniform director distribution

    NASA Astrophysics Data System (ADS)

    Aksenova, E. V.; Karetnikov, A. A.; Karetnikov, N. A.; Kovshik, A. P.; Ryumtsev, E. I.; Sakhatskii, A. S.; Svanidze, A. V.

    2016-05-01

    The electric field-induced reorientation of a nematic liquid crystal in cells with a planar helicoidal or a homeoplanar structure of a director field is studied theoretically and experimentally. The dependences of the capacitances of these systems on the voltage in an applied electric field below and above the Fréedericksz threshold are experimentally obtained and numerically calculated. The calculations use the director distribution in volume that is obtained by direct minimization of free energy at various voltages. The inhomogeneity of the electric field inside a cell is taken into account. The calculation results are shown to agree with the experimental data.

  4. Direct Observation of Ion Distributions near Electrodes in Ionic Polymer Actuators Containing Ionic Liquids

    PubMed Central

    Liu, Yang; Lu, Caiyan; Twigg, Stephen; Ghaffari, Mehdi; Lin, Junhong; Winograd, Nicholas; Zhang, Q. M.

    2013-01-01

    The recent boom of energy storage and conversion devices, exploiting ionic liquids (ILs) to enhance the performance, requires an in-depth understanding of this new class of electrolytes in device operation conditions. One central question critical to device performance is how the mobile ions accumulate near charged electrodes. Here, we present the excess ion depth profiles of ILs in ionomer membrane actuators (Aquivion/1-butyl-2,3-dimethylimidazolium chloride (BMMI-Cl), 27 μm thick), characterized directly by Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) at liquid nitrogen temperature. Experimental results reveal that for the IL studied, cations and anions are accumulated at both electrodes. The large difference in the total volume occupied by the excess ions between the two electrodes cause the observed large bending actuation of the actuator. Hence we demonstrate that ToF-SIMS experiment provides great insights on the physics nature of ionic devices. PMID:23512124

  5. Spatially resolved distribution function and the medium-range order in metallic liquid and glass

    SciTech Connect

    Fang, Xiaowei; Wang, Cai-Zhuang; Hao, Shaogang; Kramer, Matthew; Yao, Yongxin; Mendelev, Mikhail; Napolitano, Ralph; Ho, Kai-Ming

    2011-12-23

    The structural description of disordered systems has been a longstanding challenge in physical science. We propose an atomic cluster alignment method to reveal the development of three-dimensional topological ordering in a metallic liquid as it undercools to form a glass. By analyzing molecular dynamic (MD) simulation trajectories of a Cu{sub 64.5}Zr{sub 35.5} alloy, we show that medium-range order (MRO) develops in the liquid as it approaches the glass transition. Specifically, around Cu sites, we observe 'Bergman triacontahedron' packing (icosahedron, dodecahedron and icosahedron) that extends out to the fourth shell, forming an interpenetrating backbone network in the glass. The discovery of Bergman-type MRO from our order-mining technique provides unique insights into the topological ordering near the glass transition and the relationship between metallic glasses and quasicrystals.

  6. Method for chemical amplification based on fluid partitioning in an immiscible liquid

    DOEpatents

    Anderson, Brian L.; Colston, Bill W.; Elkin, Christopher J.

    2015-06-02

    A system for nucleic acid amplification of a sample comprises partitioning the sample into partitioned sections and performing PCR on the partitioned sections of the sample. Another embodiment of the invention provides a system for nucleic acid amplification and detection of a sample comprising partitioning the sample into partitioned sections, performing PCR on the partitioned sections of the sample, and detecting and analyzing the partitioned sections of the sample.

  7. Apparatus for chemical amplification based on fluid partitioning in an immiscible liquid

    DOEpatents

    Anderson, Brian L.; Colston, Bill W.; Elkin, Christopher J.

    2012-05-08

    A system for nucleic acid amplification of a sample comprises partitioning the sample into partitioned sections and performing PCR on the partitioned sections of the sample. Another embodiment of the invention provides a system for nucleic acid amplification and detection of a sample comprising partitioning the sample into partitioned sections, performing PCR on the partitioned sections of the sample, and detecting and analyzing the partitioned sections of the sample.

  8. Swift heavy ion induced nano-dimensional phase separation in liquid immiscible binary Mn-Bi

    NASA Astrophysics Data System (ADS)

    Srivastava, S. K.; Khan, S. A.; Sudheer Babu, P.; Avasthi, D. K.

    2014-08-01

    Pulsed laser deposited 60 nm thin film of homogeneous Mn0.82Bi0.18 composite has been irradiated by 100 MeV Au ions at fluence 1 × 1013 ions/cm2, and investigated by field emission scanning electron microscopy, X-ray diffraction, magnetic hysteresis, X-ray photoelectron spectroscopy, and nanoindentation measurements. Dispersed nanostructures of soft Bi-rich phase of about 20 nm diameter emerged in a hard Mn-rich matrix on irradiation. Such structures, as synthesized by the present novel swift heavy ion irradiation approach, are usable as self-lubricating thin films.

  9. Measurement and Estimation of Organic-Liquid/Water Interfacial Areas for Several Natural Porous Media

    SciTech Connect

    Brusseau, M.L.; Narter, M.; Schnaar, G.; Marble, J.

    2009-06-01

    The objective of this study was to quantitatively characterize the impact of porous-medium texture on interfacial area between immiscible organic liquid and water residing within natural porous media. Synchrotron X-ray microtomography was used to obtain high-resolution, three-dimensional images of solid and liquid phases in packed columns. The image data were processed to generate quantitative measurements of organic-liquid/water interfacial area and of organic-liquid blob sizes. Ten porous media, comprising a range of median grain sizes, grain-size distributions, and geochemical properties, were used to evaluate the impact of porous-medium texture on interfacial area. The results show that fluid-normalized specific interfacial area (A{sub f}) and maximum specific interfacial area (A{sub m}) correlate very well to inverse median grain diameter. These functionalities were shown to result from a linear relationship between effective organic-liquid blob diameter and median grain diameter. These results provide the basis for a simple method for estimating specific organic-liquid/water interfacial area as a function of fluid saturation for a given porous medium. The availability of a method for which the only parameter needed is the simple-to-measure median grain diameter should be of great utility for a variety of applications.

  10. Determination of birefringence and slow axis distribution using an interferometric measurement system with liquid crystal phase shifter.

    PubMed

    Nose, Toshiaki; Kamata, Keisuke; Takeuchi, Toru; Okano, Keiju; Fujita, Naoko; Muraguchi, Hajime; Ozaki, Noriaki; Honma, Michinori; Ito, Ryouta

    2014-11-01

    It is known that liquid crystal (LC) cells are useful as compact and easy-to-handle phase shifters that are readily coupled into the optics of standard microscope systems. Here, a uniformly aligned molecular LC phase shifter is introduced into a polarization microscope to attain a birefringence imaging system, using the phase-shift interferometric technique. Since the birefringence can be determined accurately only when the optical axis of the sample is parallel or perpendicular to the slow axis (variable axis) of the LC phase shifter, an improved data analysis method is proposed for determining the birefringence independently of the direction; a simple method of determining the slow axis distribution is also demonstrated. Measurements of the birefringence and slow axis distribution properties of a potato starch particle are demonstrated to confirm the novel determination method. PMID:25402881

  11. Rapid determination of γ-value and xanthate group distribution on viscose by liquid-state (1)H NMR spectroscopy.

    PubMed

    Wöss, Kateryna; Weber, Hansjörg; Grundnig, Peter; Röder, Thomas; Weber, Hedda K

    2016-05-01

    A method for the determination of the γ-value and more importantly the distribution of xanthate groups on cellulose xanthate produced during the viscose process is presented. The method is based upon stabilization of xanthate groups attached to the cellulose chain by reaction with 4-methylbenzyl bromide and analysis of the resulting product by liquid-state (1)H NMR. Careful analysis of the proton-spectrum using deconvolution gave a very fast method for the measurement of the γ-value which compared well with the data obtained by IR spectroscopy. In addition it could be shown that the distribution of the xanthate groups on the anhydroglucose monomeric unit (xanthation at position 2, 3 or 6) changes significantly during ripening. The method gave useful results even for viscose with low γ-values of about 25. PMID:26877011

  12. Distribution of radionuclides and water in Bandelier Tuff beneath a former Los Alamos liquid waste disposal site after 33 years

    SciTech Connect

    Nyhan, J.W.; Drennon, B.J.; Abeele, W.V.; Trujillo, G.; Herrera, W.J.; Wheeler, M.L.; Booth, J.W.; Purtymun, W.D.

    1984-07-01

    The distribution of radionuclides and water in Bandelier Tuff beneath a former liquid waste disposal site at Los Alamos was investigated. The waste use history of the site was described, as well as several pertinent laboratory and field studies of water and radionuclide migration in Bandelier Tuff. The distribution of plutonium, /sup 241/Am, and water was determined in a set of about 800 tuff samples collected to sampling depths of 30 m beneath two absorption beds. These data were then related to site geohydrologic data. Water and radionuclide concentrations found after 33 years were compared with the results of similar studies previously performed at this site, and the implications of these comparisons are discussed relative to nuclear waste management. 19 references, 6 figures, 4 tables.

  13. Momentum Distribution and Ground-State Energy of Liquid 4He at the Absolute Zero Temperature

    NASA Astrophysics Data System (ADS)

    Nishiyama, T.; Watanabe, Y.

    1980-11-01

    In the scheme of the density and phase operator approach, the momentum distribution nk and the ground-state energy E0 are obtained by employing the structure factor and the radial distribution function calculated by Chang and Campbell for the Morse dipole-dipole potential. The condensate fraction, the ratio of the occupation number of the single-particle zero-momentum state N0/N amounts to 0.096. The momentum distribution diverges as k-1 in the low-wave number limit. The ground-state energy becomes E0=-6.9NK at the mean density ρ0=0.02185Å-3.

  14. Influence of Particle Size Distribution on the Performance of Ionic Liquid-based Electrochemical Double Layer Capacitors

    PubMed Central

    Rennie, Anthony J. R.; Martins, Vitor L.; Smith, Rachel M.; Hall, Peter J.

    2016-01-01

    Electrochemical double layer capacitors (EDLCs) employing ionic liquid electrolytes are the subject of much research as they promise increased operating potentials, and hence energy densities, when compared with currently available devices. Herein we report on the influence of the particle size distribution of activated carbon material on the performance of ionic liquid based EDLCs. Mesoporous activated carbon was ball-milled for increasing durations and the resultant powders characterized physically (using laser diffraction, nitrogen sorption and SEM) and investigated electrochemically in the form of composite EDLC electrodes. A bi-modal particle size distribution was found for all materials demonstrating an increasing fraction of smaller particles with increased milling duration. In general, cell capacitance decreased with increased milling duration over a wide range of rates using CV and galvanostatic cycling. Reduced coulombic efficiency is observed at low rates (<25 mVs−1) and the efficiency decreases as the volume fraction of the smaller particles increases. Efficiency loss was attributed to side reactions, particularly electrolyte decomposition, arising from interactions with the smaller particles. The effect of reduced efficiency is confirmed by cycling for over 15,000 cycles, which has the important implication that diminished performance and reduced cycle life is caused by the presence of submicron-sized particles. PMID:26911531

  15. Influence of Particle Size Distribution on the Performance of Ionic Liquid-based Electrochemical Double Layer Capacitors

    NASA Astrophysics Data System (ADS)

    Rennie, Anthony J. R.; Martins, Vitor L.; Smith, Rachel M.; Hall, Peter J.

    2016-02-01

    Electrochemical double layer capacitors (EDLCs) employing ionic liquid electrolytes are the subject of much research as they promise increased operating potentials, and hence energy densities, when compared with currently available devices. Herein we report on the influence of the particle size distribution of activated carbon material on the performance of ionic liquid based EDLCs. Mesoporous activated carbon was ball-milled for increasing durations and the resultant powders characterized physically (using laser diffraction, nitrogen sorption and SEM) and investigated electrochemically in the form of composite EDLC electrodes. A bi-modal particle size distribution was found for all materials demonstrating an increasing fraction of smaller particles with increased milling duration. In general, cell capacitance decreased with increased milling duration over a wide range of rates using CV and galvanostatic cycling. Reduced coulombic efficiency is observed at low rates (<25 mVs-1) and the efficiency decreases as the volume fraction of the smaller particles increases. Efficiency loss was attributed to side reactions, particularly electrolyte decomposition, arising from interactions with the smaller particles. The effect of reduced efficiency is confirmed by cycling for over 15,000 cycles, which has the important implication that diminished performance and reduced cycle life is caused by the presence of submicron-sized particles.

  16. Fully Atomistic Simulations of the Ionic Liquid Crystal [C16mim][NO3]: Orientational Order Parameters and Voids Distribution.

    PubMed

    Saielli, Giacomo

    2016-03-10

    We present a fully atomistic molecular dynamics simulation of the smectic phase of the ionic liquid crystal (ILC) 1-hexadecyl-3-methylimidazolium nitrate, [C16MIm][NO3]. We have characterized the structure of the phase by means of a set of radial distribution functions resolved along the director and in the plane of the smectic layers. The results obtained allow us to discuss the similarities in the microscopic structure of ionic liquids (ILs) and ILCs. In addition to this, we have calculated the orientational order parameters, S, of the methylene groups of the alkyl chain and compared them with the results obtained for phospholipidic membranes from (2)H NMR experiments. We also discuss the orientational order parameters of the imidazolium ring. Finally, we analyze the distribution of voids in the ILC phase. We have found that voids of considerable volume to host a nonpolar gas, e.g. xenon, are localized in the hydrophobic layers and almost absent in the ionic layers. PMID:26849800

  17. Influence of Particle Size Distribution on the Performance of Ionic Liquid-based Electrochemical Double Layer Capacitors.

    PubMed

    Rennie, Anthony J R; Martins, Vitor L; Smith, Rachel M; Hall, Peter J

    2016-01-01

    Electrochemical double layer capacitors (EDLCs) employing ionic liquid electrolytes are the subject of much research as they promise increased operating potentials, and hence energy densities, when compared with currently available devices. Herein we report on the influence of the particle size distribution of activated carbon material on the performance of ionic liquid based EDLCs. Mesoporous activated carbon was ball-milled for increasing durations and the resultant powders characterized physically (using laser diffraction, nitrogen sorption and SEM) and investigated electrochemically in the form of composite EDLC electrodes. A bi-modal particle size distribution was found for all materials demonstrating an increasing fraction of smaller particles with increased milling duration. In general, cell capacitance decreased with increased milling duration over a wide range of rates using CV and galvanostatic cycling. Reduced coulombic efficiency is observed at low rates (<25 mVs(-1)) and the efficiency decreases as the volume fraction of the smaller particles increases. Efficiency loss was attributed to side reactions, particularly electrolyte decomposition, arising from interactions with the smaller particles. The effect of reduced efficiency is confirmed by cycling for over 15,000 cycles, which has the important implication that diminished performance and reduced cycle life is caused by the presence of submicron-sized particles. PMID:26911531

  18. Forming Nanoparticle Monolayers at Liquid-Air Interfaces by Using Miscible Liquids.

    PubMed

    Zhang, Datong; Hu, Jiayang; Kennedy, Kathleen M; Herman, Irving P

    2016-08-23

    One standard way of forming monolayers (MLs) of nanoparticles (NPs) is to drop-cast a NP dispersion made using one solvent onto a second, immiscible solvent; after this upper solvent evaporates, the NP ML can be transferred to a solid substrate by liftoff. We show that this previously universal use of only immiscible solvent pairs can be relaxed and close-packed, hexagonally ordered NP monolayers can self-assemble at liquid-air interfaces when some miscible solvent pairs are used instead. We demonstrate this by drop-casting an iron oxide NP dispersion in toluene on a dimethyl sulfoxide (DMSO) liquid substrate. The NPs are energetically stable at the DMSO surface and remain there even with solvent mixing. Excess NPs coagulate and precipitate in the DMSO, and this limits NPs at the surface to approximately 1 ML. The ML domains at the surface nucleate independently, which is in contrast to ML growth at the receding edge of the drying drop, as is common in immiscible solvent pair systems and seen here for the toluene/diethylene glycol immiscible solvent pair system. This new use of miscible solvent pairs can enable the formation of MLs for a wider range of NPs. PMID:27458656

  19. Electrochemical reduction of aromatic ketones in 1-butyl-3-methylimidazolium-based ionic liquids in the presence of carbon dioxide: the influence of the ketone substituent and the ionic liquid anion on bulk electrolysis product distribution.

    PubMed

    Zhao, Shu-Feng; Horne, Mike; Bond, Alan M; Zhang, Jie

    2015-07-15

    Electrochemical reduction of aromatic ketones, including acetophenone, benzophenone and 4-phenylbenzophenone, has been undertaken in 1-butyl-3-methylimidazolium-based ionic liquids containing tetrafluoroborate ([BF4](-)), trifluoromethanesulfonate ([TfO](-)) and tris(pentafluoroethyl)trifluorophosphate ([FAP](-)) anions in the presence of carbon dioxide in order to investigate the ketone substituent effect and the influence of the acidic proton on the imidazolium cation (C2-H) on bulk electrolysis product distribution. For acetophenone, the minor products were dimers (<10%) in all ionic liquids, which are the result of acetophenone radical anion coupling. For benzophenone and 4-phenylbenzophenone, no dimers were formed due to steric hindrance. In these cases, even though carboxylic acids were obtained, the main products generated were alcohols (>50%) derived from proton coupled electron transfer reactions involving the electrogenerated radical anions and C2-H. In the cases of both acetophenone and benzophenone, the product distribution is essentially independent of the ionic liquid anion. By contrast, 4-phenylbenzophenone shows a product distribution that is dependent on the ionic liquid anion. Higher yields of carboxylic acids (∼40%) are obtained with [TfO](-) and [FAP](-) anions because in these ionic liquids the C2-H is less acidic, making the formation of alcohol less favourable. In comparison with benzophenone, a higher yield of carboxylic acid (>30% versus ∼15%) was obtained with 4-phenylbenzophenone in all ionic liquids due to the weaker basicity of 4-phenylbenzophenone radical anion. PMID:26136079

  20. Radionuclide distribution in TMI-2 reactor building basement liquids and solids

    SciTech Connect

    Horan, J.T.; McIsaac, C.V.; Keefer, D.G.

    1984-01-01

    As a result of the TMI-2 accident, approximately 2.46 x 10/sup 6/ L of contaminated water were released to the Reactor Building basement. The principal fission product release pathway from the damaged core was through the reactor coolant system (RCS) to the pressurizer, through the pressure-operated relief valve (PORV) on the pressurizer to the Reactor Coolant Drain Tank (RCDT), and then through the RCDT rupture disk to the Reactor Building basement. Since August 1979, a number of efforts have been made to determine the location, quantity, and composition of fission products released to the Reactor Building basement. These efforts have included sampling of the basement water and solids, the basement sump pump recirculation line, the RCDT, and visual surveys using a closed circuit television (CCTV) system. The analysis of basement samples has provided data on the physical and radioisotopic characteristics of the liquids and solids. This paper describes the sample collection techniques and discusses radiochemical analyses results.

  1. Immobilization of organic liquid wastes

    SciTech Connect

    Greenhalgh, W.O.

    1985-08-07

    This report describes a portland cement immobilization process for the disposal treatment of radioactive organic liquid wastes which would be generated in a a FFTF fuels reprocessing line. An incineration system already on-hand was determined to be too costly to operate for the 100 to 400 gallons per year organic liquid. Organic test liquids were dispersed into an aqueous phosphate liquid using an emulsifier. A total of 109 gallons of potential and radioactive aqueous immiscible organic liquid wastes from Hanford 300 Area operations were solidified with portland cement and disposed of as solid waste during a 3-month test program with in-drum mixers. Waste packing efficiencies varied from 32 to 40% and included pump oils, mineral spirits, and TBP-NPH type solvents.

  2. Lattice Boltzmann simulation of the rise and dissolution of two-dimensional immiscible droplets

    NASA Astrophysics Data System (ADS)

    Chen, Cheng; Zhang, Dongxiao

    2009-10-01

    We used a coupled multiphase lattice Boltzmann (LB) model to simulate the dissolution of immiscible liquid droplets in another liquid during the rising process resulting from buoyancy. It was found that there existed a terminal rise velocity for each droplet, and there was a power law relationship between the Eötvös (Eo) number and the terminal Reynolds (Re) number. Our simulation results were in agreement with the empirical correlation derived for predicting bubble rise. When more than two identical droplets rose simultaneously in a close proximity, the average terminal rise velocity was lower than that of a single droplet with the same size because of the mutual resistant interactions. The droplet trajectories at the noncentral positions were not straight because of the nonzero net horizontal forces acting on the droplets. The Damkohler (Da) and Peclet (Pe) numbers were varied to investigate the coupling between droplet size, flow field, dissolution at the interface, and solute transport. For a given Pe, increasing Da led to a higher dissolution rate. For a given Da, increasing Pe led to a higher dissolution rate. For a large Da and a small Pe, the process near the interface was diffusion limited, and the advective flow relative to the droplet resulting from droplet rise was unable to move the accumulated solute away from the interface quickly. In this case, it was favorable to split the single droplet into as many small ones as possible in order to increase the interface area per unit mass and consequently enhance the whole dissolution process. For a small Da and a large Pe, the process was dissolution limited near the interface. The mass of accumulated solute near the interface was little, so the advective flow at the top side of the droplet was able to clean the solute quickly. In this case it was favorable to keep the droplet as a single one in order to obtain a high rise velocity and consequently enhance the whole dissolution process. By studying the

  3. Effect of using miscible and immiscible healing agent on solid state self-healing system

    NASA Astrophysics Data System (ADS)

    Makenan, Siti Mastura; Jamil, Mohd Suzeren Md.

    2014-09-01

    The aim of this study is to identify the effect of using various healing agent which are miscible; poly(bisphenol-A-co-epichlorohydrin), and immiscible; poly(ethylene-co-acetate) and poly(ethylene-co-acrylic acid), on self-healing resin system. The specimens were analysed by Fourier-transform Infrared Spectrometer (FTIR), Dynamic Mechanical Thermal Analysis (DMTA), and izod test. Optical image of the sample morphology was observed using optical microscope. Healing efficiencies (HE) were evaluated using izod test. The concept of healing recovery was proved based on the use of miscible and immiscible healing agent. From the results, it can be concluded that the healable resin with miscible healing agent has the highest HE within the third healing cycle.

  4. Numerical simulations of immiscible displacement in the cavities via lattice Boltzmann method

    NASA Astrophysics Data System (ADS)

    Liang, Hong; Chai, Zhenhua; Shi, Baochang; Guo, Zhaoli; Li, Qiuxiang

    2015-12-01

    In this paper, the immiscible displacements in the different cavities are studied by the pseudo-potential lattice Boltzmann (LB) model. We first validate the model with a two-dimensional (2D) layered flow, and find that the numerical results agree well with the corresponding analytical solutions. Then, we perform some numerical simulations to study the immiscible displacements in the cavities, and focus on the effects of the surface wettability, capillary number and density ratio on the displacement efficiency. The numerical results show that the displacement efficiency increases with the increase of the capillary number at first and then presents a decrease with the capillary number when it is large enough. The increase of the contact angle θ1 or decrease of the density ratio increases the displacement efficiency but decreases the critical capillary number. Finally, it is also found that both the size and geometry of cavity have a significant influence on the displacement efficiency.

  5. The Atomic scale structure of liquid metal-electrolyte interfaces

    NASA Astrophysics Data System (ADS)

    Murphy, B. M.; Festersen, S.; Magnussen, O. M.

    2016-07-01

    Electrochemical interfaces between immiscible liquids have lately received renewed interest, both for gaining fundamental insight as well as for applications in nanomaterial synthesis. In this feature article we demonstrate that the atomic scale structure of these previously inaccessible interfaces nowadays can be explored by in situ synchrotron based X-ray scattering techniques. Exemplary studies of a prototypical electrochemical system - a liquid mercury electrode in pure NaCl solution - reveal that the liquid metal is terminated by a well-defined atomic layer. This layering decays on length scales of 0.5 nm into the Hg bulk and displays a potential and temperature dependent behaviour that can be explained by electrocapillary effects and contributions of the electronic charge distribution on the electrode. In similar studies of nanomaterial growth, performed for the electrochemical deposition of PbFBr, a complex nucleation and growth behaviour is found, involving a crystalline precursor layer prior to the 3D crystal growth. Operando X-ray scattering measurements provide detailed data on the processes of nanoscale film formation.

  6. The Atomic scale structure of liquid metal-electrolyte interfaces.

    PubMed

    Murphy, B M; Festersen, S; Magnussen, O M

    2016-08-01

    Electrochemical interfaces between immiscible liquids have lately received renewed interest, both for gaining fundamental insight as well as for applications in nanomaterial synthesis. In this feature article we demonstrate that the atomic scale structure of these previously inaccessible interfaces nowadays can be explored by in situ synchrotron based X-ray scattering techniques. Exemplary studies of a prototypical electrochemical system - a liquid mercury electrode in pure NaCl solution - reveal that the liquid metal is terminated by a well-defined atomic layer. This layering decays on length scales of 0.5 nm into the Hg bulk and displays a potential and temperature dependent behaviour that can be explained by electrocapillary effects and contributions of the electronic charge distribution on the electrode. In similar studies of nanomaterial growth, performed for the electrochemical deposition of PbFBr, a complex nucleation and growth behaviour is found, involving a crystalline precursor layer prior to the 3D crystal growth. Operando X-ray scattering measurements provide detailed data on the processes of nanoscale film formation. PMID:27301317

  7. Structures of immiscible Al-In alloys solidified under microgravity conditions

    NASA Technical Reports Server (NTRS)

    Potard, C.

    1981-01-01

    Four samples of the immiscible Al-In system having monotectic and hypermonotectic compositions were solidified under microgravity during the NASA-SPAR IX flight of January 20th, 1981. The experimental thermal and physico-chemical conditions actually achieved have been analysed. Radiographic and metallographic observations of the samples show a non-regular dispersed primary phase inside the monotectic matrix. These observations are commented on the basis of capillarity and solidification aspects.

  8. Classical solvability of the stationary free boundary problem describing the interface formation between two immiscible fluids

    NASA Astrophysics Data System (ADS)

    Kusaka, Yoshiaki

    2016-06-01

    Stationary free boundary problems related to the formation of the interface between two immiscible fluids are investigated. The corresponding models were introduced originally by Shikhmurzaev to remove singularities arising in contact-line problems. We consider two models which are derived under different assumptions for the structure of the interfacial layer, and prove the existence of rotationally symmetric solutions in Hölder spaces for a sufficiently small rotationally symmetric external force.

  9. Magnetic resonance imaging of immiscible fluid displacement in porous media

    NASA Astrophysics Data System (ADS)

    Chen, Jing-Den; Dias, Madalena M.; Patz, Samuel; Schwartz, Lawrence M.

    1988-09-01

    Magnetic resonance imaging is used to study oil and water invasion in a model porous medium. Images taken normal to the flow direction are processed to give both the oil saturation and the fractal character of the oil distribution. These images reveal qualitative differences between the cases of invasion by the wetting (water) and nonwetting (oil) fluids. We have also found large saturation fluctuations in the residual oil state in which the oil consists entirely of disconnected blobs.

  10. Molecular orientation distributions during injection molding of liquid crystalline polymers: Ex situ investigation of partially filled moldings

    SciTech Connect

    Fang, Jun; Burghardt, Wesley R.; Bubeck, Robert A.

    2013-01-10

    The development of molecular orientation in thermotropic liquid crystalline polymers (TLCPs) during injection molding has been investigated using two-dimensional wide-angle X-ray scattering coordinated with numerical computations employing the Larson-Doi polydomain model. Orientation distributions were measured in 'short shot' moldings to characterize structural evolution prior to completion of mold filling, in both thin and thick rectangular plaques. Distinct orientation patterns are observed near the filling front. In particular, strong extension at the melt front results in nearly transverse molecular alignment. Far away from the flow front shear competes with extension to produce complex spatial distributions of orientation. The relative influence of shear is stronger in the thin plaque, producing orientation along the filling direction. Exploiting an analogy between the Larson-Doi model and a fiber orientation model, we test the ability of process simulation tools to predict TLCP orientation distributions during molding. Substantial discrepancies between model predictions and experimental measurements are found near the flow front in partially filled short shots, attributed to the limits of the Hele-Shaw approximation used in the computations. Much of the flow front effect is however 'washed out' by subsequent shear flow as mold filling progresses, leading to improved agreement between experiment and corresponding numerical predictions.

  11. Size distribution of associated clusters in liquid alcohols: Interpretation of simulation results in the frame of SAFT approach

    NASA Astrophysics Data System (ADS)

    Janeček, Jiří; Paricaud, Patrice

    2013-11-01

    The size distribution and topology of associated clusters for primary alcohols is studied using molecular dynamics simulations. Liquid ethanol, propanol, butanol, hexanol, and octanol are simulated at pressure P = 1 bar and temperatures T = 300 K, T = 350 K, and T = 400 K. The fractions of molecules with different sets of hydrogen bonded partners, the size of associated cluster and the site-site distribution functions between atoms participating on hydrogen bonding are extracted from simulated trajectories. For all alcohols longer than ethanol, the length of the alkyl chain has only a marginal effect on the association. Consequently, related properties like coordination numbers of hydroxyl group, size distribution of associates, or fractions of differently coordinated alcohol molecules are independent on the molecular size. Although we employed a force-field without involved polarizability, we observe a positive cooperativity of hydrogen bonding simply as a consequence of steric and electrostatic interactions. The size and topology of associates is analyzed within the frame of 3B model of statistical association fluid theory. Although this approach enables good thermodynamic description of systems containing associating compounds, several insufficiencies appear in the description at molecular level.

  12. Thermodynamic modeling of lead distribution among matte, slag, and liquid copper

    NASA Astrophysics Data System (ADS)

    Degterov, Sergei A.; Pelton, Arthur D.

    1999-12-01

    Recently, a thermodynamic database was developed for the calculation of equilibria involved in the production of copper. The present study is concerned with the further development of the thermodynamic models and the database of model parameters for the matte, slag, and blister copper phases with a view to including Pb in the database and permitting calculations in the seven-component system Pb-Cu-Ca-Fe-Si-O-S. Thermodynamic and phase equilibrium data available in the literature are reviewed, critically assessed, and optimized with the modified quasi-chemical model. When used with the Gibbs energy minimization software and other databases of the FACT thermodynamic computing system, the database developed in the present study can be used for the calculation of matte-slag-copper-gas phase equilibria during copper smelting and converting. The distribution of lead among these phases can be computed. For example, the distribution of lead among matte, silica-saturated slag, and copper has been calculated at metal saturation, or under fixed partial pressure of SO2, and has been compared with the available experimental data. The Pb distributions among the equilibrium phases have been calculated under various conditions, which are difficult to study experimentally, such as at magnetite saturation or under various oxygen partial pressures and iron to silica ratios in the slag.

  13. A chemical approach toward low temperature alloying of immiscible iron and molybdenum metals

    SciTech Connect

    Nazir, Rabia; Ahmed, Sohail; Mazhar, Muhammad; Akhtar, Muhammad Javed; Siddique, Muhammad; Khan, Nawazish Ali; Shah, Muhammad Raza; Nadeem, Muhammad

    2013-11-15

    Graphical abstract: - Highlights: • Low temperature pyrolysis of [Fe(bipy){sub 3}]Cl{sub 2} and [Mo(bipy)Cl{sub 4}] homogeneous powder. • Easy low temperature alloying of immiscible metals like Fe and Mo. • Uniform sized Fe–Mo nanoalloy with particle size of 48–68 nm. • Characterization by EDXRF, AFM, XRPD, magnetometery, {sup 57}Fe Mössbauer and impedance. • Alloy behaves as almost superparamagnetic obeying simple –R(CPE)– circuit. - Abstract: The present research is based on a low temperature operated feasible method for the synthesis of immiscible iron and molybdenum metals’ nanoalloy for technological applications. The nanoalloy has been synthesized by pyrolysis of homogeneous powder precipitated, from a common solvent, of the two complexes, trisbipyridineiron(II)chloride, [Fe(bipy){sub 3}]Cl{sub 2}, and bipyridinemolybedenum(IV) chloride, [Mo(bipy)Cl{sub 4}], followed by heating at 500 °C in an inert atmosphere of flowing argon gas. The resulting nanoalloy has been characterized by using EDXRF, AFM, XRD, magnetometery, {sup 57}Fe Mössbauer and impedance spectroscopies. These results showed that under provided experimental conditions iron and molybdenum metals, with known miscibility barrier, alloy together to give (1:1) single phase material having particle size in the range of 48–66 nm. The magnetism of iron is considerably reduced after alloy formation and shows its trend toward superparamagnetism. The designed chemical synthetic procedure is equally feasible for the fabrication of other immiscible metals.

  14. Measurements of liquid phase residence time distributions in a pilot-scale continuous leaching reactor using radiotracer technique.

    PubMed

    Pant, H J; Sharma, V K; Shenoy, K T; Sreenivas, T

    2015-03-01

    An alkaline based continuous leaching process is commonly used for extraction of uranium from uranium ore. The reactor in which the leaching process is carried out is called a continuous leaching reactor (CLR) and is expected to behave as a continuously stirred tank reactor (CSTR) for the liquid phase. A pilot-scale CLR used in a Technology Demonstration Pilot Plant (TDPP) was designed, installed and operated; and thus needed to be tested for its hydrodynamic behavior. A radiotracer investigation was carried out in the CLR for measurement of residence time distribution (RTD) of liquid phase with specific objectives to characterize the flow behavior of the reactor and validate its design. Bromine-82 as ammonium bromide was used as a radiotracer and about 40-60MBq activity was used in each run. The measured RTD curves were treated and mean residence times were determined and simulated using a tanks-in-series model. The result of simulation indicated no flow abnormality and the reactor behaved as an ideal CSTR for the range of the operating conditions used in the investigation. PMID:25528019

  15. Impact of enhanced-flushing reagents and organic-liquid distribution on mass removal and mass-discharge reduction.

    PubMed

    Akyol, Nihat Hakan; Lee, Ann Russo; Brusseau, Mark L

    2013-10-01

    A series of column and flow-cell experiments was conducted to investigate the impact of non-uniform organic-liquid distribution on the relationship between reductions in contaminant mass discharge and reductions in source zone mass under conditions of enhanced-solubilization flushing. Trichloroethene was used as the model organic liquid, and SDS (sodium dodecyl sulfate) and ethanol were used as representative enhanced-flushing reagents. The results were compared to those of water-flood control experiments. Concentrations of trichloroethene in the effluent exhibited multi-step behavior with time, wherein multiple secondary periods of quasi steady state were observed. This non-ideal behavior was observed for both the water-flood and enhanced-flushing experiments. For all flow-cell experiments, the later stage of mass removal was controlled by the more poorly- accessible mass associated with higher-saturation zones. The profiles relating reductions in contaminant mass discharge and reductions in mass exhibited generally similar behavior for both the water-flood and enhanced-flushing experiments. This indicates that while the rates and magnitudes of mass removal are altered by the presence of a solubilization-reagent solution, the fundamental mass-removal process is not. The profiles obtained for the flow-cell systems differed from those obtained for the column systems, highlighting the impact of source-zone heterogeneity on mass-removal behavior. PMID:24563557

  16. Impact of enhanced-flushing reagents and organic-liquid distribution on mass removal and mass-discharge reduction

    PubMed Central

    Akyol, Nihat Hakan; Lee, Ann Russo; Brusseau, Mark L

    2014-01-01

    A series of column and flow-cell experiments was conducted to investigate the impact of non-uniform organic-liquid distribution on the relationship between reductions in contaminant mass discharge and reductions in source zone mass under conditions of enhanced-solubilization flushing. Trichloroethene was used as the model organic liquid, and SDS (sodium dodecyl sulfate) and ethanol were used as representative enhanced-flushing reagents. The results were compared to those of water-flood control experiments. Concentrations of trichloroethene in the effluent exhibited multi-step behavior with time, wherein multiple secondary periods of quasi steady state were observed. This non-ideal behavior was observed for both the water-flood and enhanced-flushing experiments. For all flow-cell experiments, the later stage of mass removal was controlled by the more poorly- accessible mass associated with higher-saturation zones. The profiles relating reductions in contaminant mass discharge and reductions in mass exhibited generally similar behavior for both the water-flood and enhanced-flushing experiments. This indicates that while the rates and magnitudes of mass removal are altered by the presence of a solubilization-reagent solution, the fundamental mass-removal process is not. The profiles obtained for the flow-cell systems differed from those obtained for the column systems, highlighting the impact of source-zone heterogeneity on mass-removal behavior. PMID:24563557

  17. Influence of an amorphous wall on the distribution of localized excitations in a colloidal glass-forming liquid

    NASA Astrophysics Data System (ADS)

    Gokhale, Shreyas; Hima Nagamanasa, K.; Sood, A. K.; Ganapathy, Rajesh

    2016-07-01

    Elucidating the nature of the glass transition has been the holy grail of condensed matter physics and statistical mechanics for several decades. A phenomenological aspect that makes glass formation a conceptually formidable problem is that structural and dynamic correlations in glass-forming liquids are too subtle to be captured at the level of conventional two-point functions. As a consequence, a host of theoretical techniques, such as quenched amorphous configurations of particles, have been devised and employed in simulations and colloid experiments to gain insights into the mechanisms responsible for these elusive correlations. Very often, though, the analysis of spatio-temporal correlations is performed in the context of a single theoretical framework, and critical comparisons of microscopic predictions of competing theories are thereby lacking. Here, we address this issue by analysing the distribution of localized excitations, which are building blocks of relaxation as per the dynamical facilitation (DF) theory, in the presence of an amorphous wall, a construct motivated by the random first-order transition theory (RFOT). We observe that spatial profiles of the concentration of excitations exhibit complex features such as non-monotonicity and oscillations. Moreover, the smoothly varying part of the concentration profile yields a length scale {ξc} , which we compare with a previously computed length scale {ξ\\text{dyn}} . Our results suggest a method to assess the role of dynamical facilitation in governing structural relaxation in glass-forming liquids.

  18. The use of hard- and soft-modelling to predict radiostrontium solid-liquid distribution coefficients in soils.

    PubMed

    Gil-García, C J; Rigol, A; Vidal, M

    2011-11-01

    The solid-liquid distribution coefficient (K(d)) is the parameter that governs the incorporation of contaminants in soils. Its estimation allows the prediction of the fate of contaminants in the short- and long-term after a contamination event. Here, the K(d) of radiostrontium (K(d)(Sr)), a radionuclide of significant environmental interest, was predicted by hard models, which are based on knowledge of the mechanisms governing its sorption, and by soft models based on Partial Least Squares (PLS), using a large data set with the main soil parameters. The two approaches were tested and compared for 30 soils in Spain. Correlations between the predicted and experimental values of K(d)(Sr) obtained using hard- and soft-modelling showed slopes close to 1 and regression coefficients higher than 0.95, which confirms that both approaches are able to obtain satisfactory estimates for K(d)(Sr) from soil parameters. PMID:21890173

  19. ``Seedless'' vapor-liquid-solid growth of Si and Ge nanowires: The origin of bimodal diameter distributions

    NASA Astrophysics Data System (ADS)

    Dailey, Eric; Drucker, Jeff

    2009-03-01

    We identify a previously uncharacterized vapor-liquid-solid growth mode that can produce small diameter, epitaxial ⟨110⟩ oriented Si and Ge nanowires (NWs). Disilane or digermane pyrolysis evolves H2 causing the monolayer thick Au/Si(111) layer between three dimensional Au seeds to dewet and form small Au islands. Under some conditions, these small islands facilitate "seedless" growth of small diameter NWs distinct from larger NWs that grow from the deposited seeds leading to a bimodal diameter distribution. We identify the precursor pressures and growth temperature regimes for which Si and Ge NW growth occurs in the absence of deposited seeds from the dewetted Au/Si(111) layer.

  20. Visualization and Measurement of Surface Shear Stress Vector Distributions Using Liquid Crystal Coatings

    NASA Technical Reports Server (NTRS)

    Reda, Daniel C.; Wilder, Michael C.

    1998-01-01

    When a shear-sensitive liquid crystal coating is illuminated from the normal direction by white light and observed from an oblique above-plane view angle, its color-change response to shear depends on both shear stress vector magnitude and the direction of the applied shear vector relative to the observer's in-plane line of sight. At any point, the maximum color change is always seen or measured when the local shear vector is aligned with, and directed away from, the observer; the magnitude of the color change at this vector/observer aligned orientation scales directly with shear stress magnitude. Conversely, any point exposed to a shear vector with a component directed toward the observer exhibits a noncolor-change response, always characterized by a rusty red or brown color, independent of both shear magnitude and direction. Based on this knowledge, full-surface shear stress vector visualization and measurement methodologies were formulated and successfully demonstrated. The present paper reviews the observations and measurements that led to the development of these methodologies and applications of both are discussed.

  1. The distribution of chromium among orthopyroxene, spinel and silicate liquid at atmospheric pressure

    NASA Technical Reports Server (NTRS)

    Barnes, S. J.

    1986-01-01

    The Cr distributions for a synthetic silicate melt equilibrated with bronzitic orthopyroxene and chromite spinel between 1334 and 1151 C over a range of oxygen fugacities between the nickel-nickel oxide and iron-wuestite buffers are studied. The occurrence, chemical composition, and structure of the orthopyroxene-silicate melt and the spinel-silicate melt are described. It is observed that the Cr content between bronzite and the melt increases with falling temperature along a given oxygen buffer and decreases with falling oxygen fugacity at a given temperature; however, the Cr content of the melt in equilibrium with spinel decreases with falling temperature and increases with lower oxygen fugacity.

  2. Effect of Humic Acid on Migration, Distribution and Remediation of Dense Non-aqueous Phase Liquids: A laboratory investigation

    NASA Astrophysics Data System (ADS)

    Cheng, Z.; Wu, J.; Xu, H.; Gao, Y.

    2014-12-01

    Over the last decades, dense non-aqueous phase liquids (DNAPLs) contamination in the subsurface increases with the rapid development of oil industry and becomes the focus of many studies. The migration, distribution and remediation efficiency of DNAPLs in the subsurface environment are greatly affected by the solution chemistry besides the physical heterogeneities of aquifers. Humic acid (HA), which is ubiquitous in natural environments, is a surface active substance exhibiting solubility enhancement behavior for hydrophobic organic compounds such as DNAPLs. Here we reported a laboratory investigation to study the effects of HA on the infiltration, immobilization and subsequent recovery of DNAPL in porous media. Tetrachloroethylene (PCE) was selected as the representative DNAPL in this study. Two-dimensional (2-D) sandbox experiments were conducted to investigate the effects of different HA concentrations on the transport, distribution of PCE and the remediation of PCE using surfactant (Tween 80) flushing in a saturated porous media system. The surfactant flushing of PCE was performed after the PCE transport and distribution had reached equilibrium. A light transmission visualization method with charge-coupled device (CCD) camera was adopted to visualize PCE distribution and quantify its saturation. In addition, the experiments were also designed to gather data for the validation of multiphase flow models. Effluent samples were collected to determine dissolved PCE concentrations. PCE solubilization and PCE-water interfacial tension were experimentally determined in aqueous solutions of varying HA concentrations. The experimental results showed that the presence of HA can have a dramatic impact on PCE flow and entrapment, and significantly improved the recovery of PCE during surfactant enhanced aquifer remediation (SEAR). The findings are of use for better understanding of the migration and entrapment of DNAPLs and developing of SEAR technology.

  3. Spreading of miscible liquids

    NASA Astrophysics Data System (ADS)

    Walls, Daniel J.; Haward, Simon J.; Shen, Amy Q.; Fuller, Gerald G.

    2016-05-01

    Miscible liquids commonly contact one another in natural and technological situations, often in the proximity of a solid substrate. In the scenario where a drop of one liquid finds itself on a solid surface and immersed within a second, miscible liquid, it will spread spontaneously across the surface. We show experimental findings of the spreading of sessile drops in miscible environments that have distinctly different shape evolution and power-law dynamics from sessile drops that spread in immiscible environments, which have been reported previously. We develop a characteristic time to scale radial data of the spreading sessile drops based on a drainage flow due to gravity. This time scale is effective for a homologous subset of the liquids studied. However, it has limitations when applied to significantly chemically different, yet miscible, liquid pairings; we postulate that the surface energies between each liquid and the solid surface becomes important for this other subset of the liquids studied. Initial experiments performed with pendant drops in miscible environments support the drainage flow observed in the sessile drop systems.

  4. Method and apparatus for selectively detecting one of two immiscible liquids in the presence of the other liquid

    DOEpatents

    Cry, J.W.; Kirkham, R.R.; McBride, J.F.; Simmons, C.S.; Gee, G.W.

    1990-02-06

    Oil is detected in the presence of water by placing a translucent, porous body of hydrophobic material in contact with the oil and water and detecting the amount by which light incident on the body is attenuated on propagation through the body. 4 figs.

  5. Method and apparatus for selectively detecting one of two immiscible liquids in the presence of the other liquid

    DOEpatents

    Cry, John W.; Kirkham, Randy R.; McBride, John F.; Simmons, Carver S.; Gee, Glendon W.

    1990-01-01

    Oil is detected in the presence of water by placing a translucent, porous body of hydrophobic material in contact with the oil and water and detecting the amount by which light incident on the body is attenuated on propagation through the body.

  6. Survey of the literature: Controlled generation of liquid droplets

    NASA Astrophysics Data System (ADS)

    Allan, Craig R.; Carlon, Hugh R.; Stuempfle, Arthur K.; Hoffer, Thomas E.; Pitter, Richard L.

    1988-08-01

    Techniques utilized in generating large drops from visco-elastic liquids, which are also referred to as non-Newtonian liquids, are surveyed, reviewed and evaluated. The minimum droplet size of interest was 0.2 mm (200 micrometers). Drop generation techniques considered include the capillary dropper, liquid jets, atomization, the spinning disc, vaporization-condensation, impulse generation, and other techniques. Of these, only three generator configurations were found to meet experimental requirements. These included a drop impulse/ejection system, a capillary device utilizing immiscible liquids, and a microfilm technique whereby presized drops are released into free fall by the sudden removal of the supporting microfilm utilizing a liquid solvent spray technique.

  7. Pharmacokinetics in rats and tissue distribution in mouse of magnoflorine by ultra performance liquid chromatography-tandem mass spectrometry

    PubMed Central

    Bao, Shihui; Geng, Peiwu; Wang, Shuanghu; Zhou, Yunfang; Hu, Lufeng; Yang, Xuezhi

    2015-01-01

    Magnoflorine is one of the most widespread aporphine alkaloids. In this work, a sensitive and selective ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the determination of magnoflorine in rat plasma and mouse tissue have been developed and validated. After addition of nuciferine as an internal standard (IS), protein precipitation by acetonitrile-methanol (9:1, v/v) was used for samples treatment. Chromatographic separation was achieved on a UPLC BEH C18 column (2.1 mm×100 mm, 1.7 μm) with 0.1% formic acid and acetonitrile as the mobile phase with gradient elution. An electrospray ionization source was applied and operated in positive ion mode; multiple reactions monitoring (MRM) mode was used for quantification using target fragment ions m/z 342.8→298.2 for magnoflorine and m/z 296.0→265.1 for IS. Calibration plots were linear throughout the range 2-2000 ng/mL for magnoflorine in rat plasma and tissue. Mean recoveries of magnoflorine in rat plasma were better than 83.0%. RSD of intra-day and inter-day precision were both less than 9%. The accuracy of the method was between 95.5% and 107.5%. The method was successfully applied to pharmacokinetics and tissue distribution study of magnoflorine. The absolute bioavailability of magnoflorine was reported as 22.6%. The magnoflorine underwent a rapid and wide distribution to tissues; the level of magnoflorine in liver is highest, then followed by heart, spleen and lung. Based on tissue distribution data, a back-propagation artificial neural network (BP-ANN) method was developed and it could be used to predict the concentrations of magnoflorine in tissues. PMID:26884929

  8. Electrically actuated liquid iris.

    PubMed

    Xu, Miao; Ren, Hongwen; Lin, Yi-Hsin

    2015-03-01

    We report an adaptive iris using dielectric liquids and a radial-interdigitated electrode. A black liquid is confined by a circular gasket with a donut shape. The surrounding of the black liquid is filled with an immiscible liquid. In the relaxing state, the black liquid obtains the largest clear aperture. By applying a voltage, the surface of the black liquid is stretched by the generated dielectric force, resulting in a reduction of its aperture. For the demonstrated iris, the diameter of the aperture can be changed from ∼4.7  mm to ∼1.2  mm when the voltage is applied from 0 to 70  V(rms). The aperture ratio is ∼94%. Owing to the radial-interdigitated electrode, the aperture size of the iris can be effectively switched with a reasonably fast response time. The optical switch is polarization-insensitive. The potential applications of our iris are light shutters, optical attenuators, biomimicry, and wearable devices. PMID:25723444

  9. Solid-liquid distribution of selected concrete admixtures in hardened cement pastes

    SciTech Connect

    Glaus, Martin A.

    2006-07-01

    The distribution between hardened cement paste and cement pore water of selected concrete admixtures (BZMs), i.e., sulfonated naphthalene-formaldehyde condensate (NS), lignosulfonate (LS) and a gluconate-containing plasticiser used at the Paul Scherrer Institute for waste conditioning, was measured. Sorption data were fitted to a single-site Langmuir isotherm with affinity constants K = (19 {+-} 4) dm{sup 3} g{sup -1} for NS, K = (2.1 {+-} 0.6) dm{sup 3} g{sup -1} for LS and sorption capacities q = (81 {+-} 16) g kg{sup -1} for NS, q = (43 {+-} 8) g kg{sup -1} for LS. In the case of gluconate, a two-site Langmuir sorption model was necessary to fit the data satisfactorily. Sorption parameters for gluconate were K {sub 1} = (2 {+-} 1) x 10{sup 6} dm{sup 3} mol{sup -1} and q {sub 1} = (0.04 {+-} 0.02) mol kg{sup -1} for the stronger binding site and K {sub 2} = (2.6 {+-} 1.1) x 10{sup 3} dm{sup 3} mol{sup -1} and q {sub 2} = (0.7 {+-} 0.3) mol kg{sup -1} for the weaker binding site. Desorption of these BZMs from cement pastes and pore water in cement specimens prepared in the presence of the BZMs were then used to test the model. It was found that only minor parts of NS and LS could be mobilised as long as the cement composition was intact, whereas the sorption of gluconate was found to be reversible. The Langmuir model makes valuable predictions in the qualitative sense in that the pore water concentration of the BZMs is reduced by several orders of magnitude as compared to the initial concentrations. In view of the necessity for conservative predictions used in the safety analysis for disposal of radioactive waste, however, the predictions are unsatisfactory in that the measured pore water concentrations of NS and LS were considerably larger than the predicted values. This conclusion does not apply for gluconate, because its concentration in cement pore water was below the detection limit of {approx}50 nM.

  10. A comparative flow visualization study of thermocapillary flow in drops in liquid-liquid systems

    NASA Technical Reports Server (NTRS)

    Balasubramaniam, R.; Rashidnia, N.

    1991-01-01

    Experiments are performed to visualize thermocapillary flow in drops in an immiscible host liquid. The host liquid used is silicone oil. Drops of three different liquids are used, viz, vegetable oil, water-methanol mixture anad pure methanol. Clear evidence of thermocapillary flow is seen in vegetable oil drops. For a mixture of water and methanol (approximately 50-50 by weight), natural convection is seen to dominate the flow outside the drop. Pure methanol drops exhibit thermocapillary flow, but dissolve in silicone oil. A small amount of water added to pure methanol significantly reduces the dissolution. Flow oscillations occur in this system for both isothermal and non-isothermal conditions.

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

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

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

  12. The influence of gravity level during directional solidification of immiscible alloys

    NASA Technical Reports Server (NTRS)

    Andrews, J. B.; Schmale, A. L.; Sandlin, A. C.

    1992-01-01

    During directional solidification of immiscible (hypermonotectic) alloys it is theoretically possible to establish a stable macroscopically-planar solidification front, and thus avoid sedimentation. Unfortunately, convective instabilities often occur which interfere with the directional solidification process. In this paper, stability conditions are discussed and results presented from directional solidification studies carried out aboard NASA's KC-135 zero-g aircraft. Samples were directionally solidified while the effective gravity level was varied from approximately 0.01 g for 25 s to 1.8 g for 45 s. Dramatic variations in microstructure were observed with gravity level during solidification.

  13. Nonequilibrium dynamics induced by miscible–immiscible transition in binary Bose–Einstein condensates

    NASA Astrophysics Data System (ADS)

    Eto, Yujiro; Takahashi, Masahiro; Kunimi, Masaya; Saito, Hiroki; Hirano, Takuya

    2016-07-01

    We have observed and characterized the nonequilibrium spatial dynamics of a two-component 87Rb Bose–Einstein condensate (BEC) that is controllable switched back and forth between the miscible and immiscible phases of the phase separation transition by changing the internal states of the 87Rb atoms. The subsequent evolution exhibits large scale oscillations of the spatial structure that involve component mixing and separation. We show that the larger total energy of the miscible system results in a higher oscillation frequency. This investigation introduces a new technique to control the miscibility and the spatial degrees of freedom in atomic BECs.

  14. Pharmacokinetics, tissue distribution and excretion of peimisine in rats assessed by liquid chromatography-tandem mass spectrometry.

    PubMed

    Chen, Lihua; Li, Dongxun; Zhang, Guosong; Zhang, Wei; Zhang, Lihua; Guan, Yongmei; Zhu, Weifeng; Liu, Hongning

    2015-06-01

    Peimisine, the common ingredient of "zhebeimu" groups and "chuanbeimu" groups, is responsible for the expectorant and cough relieving effects. The aim of this study was to investigate the pharmacokinetics, tissue distribution and excretion of peimisine in male and female SD (Sprague-Dawley) rats by a rapid and sensitive LC-MS/MS (liquid chromatography-tandem mass spectrometry) method used carbamazepine as the internal standard after oral administration, carbamazepine was stated as an IS. The results showed that peimisine was slowly distributed, and eliminated from rat plasma and manifested linear dynamics in a dose range of 0.26-6.5 mg/kg. Tested by ANOVA, there were gender differences in the pharmacokinetic parameters of AUC(0-t), AUC(0-∞) among a single dose of 0.26, 1.3, 6.5 mg/kg (P < 0.05). Drug blood and tissue levels in male rats were significantly higher than the female counterparts after oral administration, while both the males and the females showed high drug levels in spleen, kidney, lung, liver and heart. On the other hand, the peimisine levels that can be reached in uterus, ovary, testis and brain is low. The excretion study showed that little administered peimisine (<0.7%) was recovered in the male and female bile. Approximately 13.46 and 15.05% were recovered in female urine and feces, while 43.07 and 7.49% were recovered in male urine and feces, respectively, which indicated that the major elimination route of male rats was urine excretion. In addition, there was significant differences in total cumulative excretive ratio of peimisine in feces (P < 0.05) and no significant differences in the urine (P > 0.05) at a dose of 1.3 mg/kg. PMID:25001900

  15. Capillary foams: stabilization and functionalization of porous liquids and solids.

    PubMed

    Zhang, Yi; Allen, Michael C; Zhao, Ruiyang; Deheyn, Dimitri D; Behrens, Sven H; Meredith, J Carson

    2015-03-10

    Liquid foams are two-phase systems in which a large volume of gas is dispersed as bubbles in a continuous liquid phase. These foams are ubiquitous in nature. In addition, they are found in industrial applications, such as pharmaceutical formulation, food processing, wastewater treatment, construction, and cosmetics. Recently, we reported a new type of foam material, capillary foam, which is stabilized by the synergistic action of particles and a small amount of an immiscible secondary liquid. In this study, we explore in more detail the foam preparation routes. To illustrate some of the potential applications, we create vividly colored wet and dried foams, which are difficult to prepare using traditional methods, and load-bearing porous solids. The combined action of particles and immiscible secondary fluid confers exceptional stability to capillary foams and many options for functionalization, suggesting a wide range of possible applications. PMID:25689577

  16. Differentiation and Distributions of DNA/Cisplatin Crosslinks by Liquid Chromatography-Electrospray Ionization-Infrared Multiphoton Dissociation Mass Spectrometry

    PubMed Central

    Xu, Zhe; Brodbelt, Jennifer S.

    2013-01-01

    Liquid chromatography-electrospray ionization-infrared multiphoton dissociation (IRMPD) mass spectrometry was developed to investigate the distributions of intrastrand crosslinks formed between cisplatin and two oligodeoxynucleotides (ODNs), d(A1T2G3G4G5T6A7C8C9C10A11T12) (G3-D) and its analog d(A1T2G3G4G5T6T7C8C9C10A11T12) (G3-H), that have been reported to adopt different secondary structures in solution. Based on the formation of site-specific fragment ions upon IRMPD, two isobaric crosslink products were differentiated for each ODN. The preferential formation of G3G4 and G4G5 crosslinks was determined as a function of reaction conditions, including incubation temperature and presence of metal ions. G3-D consistently exhibited a greater preference for formation of the G4G5 crosslink compared to the G3-H ODN. The ratio of G3G4:G4G5 crosslinks increased for both G3-D and G3-H at higher incubation temperatures or when metal salts were added. Comparison of the IRMPD fragmentation patterns of the unmodified ODNs and the intramolecular platinated crosslinks indicated that backbone cleavage was significantly suppressed near the crosslink. PMID:24135806

  17. Tin-carbon clusters and the onset of microscopic level immiscibility: Experimental and computational study.

    PubMed

    Bernstein, J; Landau, A; Zemel, E; Kolodney, E

    2015-09-21

    We report the experimental observation and computational analysis of the binary tin-carbon gas phase species. These novel ionic compounds are generated by impact of C60(-) anions on a clean tin target at some kiloelectronvolts kinetic energies. Positive Sn(m)C(n)(+) (m = 1-12, 1 ≤ n ≤ 8) ions were detected mass spectrometrically following ejection from the surface. Impact induced shattering of the C60(-) ion followed by sub-surface penetration of the resulting atomic carbon flux forces efficient mixing between target and projectile atoms even though the two elements (Sn/C) are completely immiscible in the bulk. This approach of C60(-) ion beam induced synthesis can be considered as an effective way for producing novel metal-carbon species of the so-called non-carbide forming elements, thus exploring the possible onset of molecular level miscibility in these systems. Sn2C2(+) was found to be the most abundant carbide cluster ion. Its instantaneous formation kinetics and its measured kinetic energy distribution while exiting the surface demonstrate a single impact formation/emission event (on the sub-ps time scale). Optimal geometries were calculated for both neutral and positively charged species using Born-Oppenheimer molecular dynamics for identifying global minima, followed by density functional theory (DFT) structure optimization and energy calculations at the coupled cluster singles, doubles and perturbative triples [CCSD(T)] level. The calculated structures reflect two distinct binding tendencies. The carbon rich species exhibit polyynic/cummulenic nature (tin end capped carbon chains) while the more stoichiometrically balanced species have larger contributions of metal-metal bonding, sometimes resulting in distinct tin and carbon moieties attached to each other (segregated structures). The Sn2C(n) (n = 3-8) and Sn2C(n)(+) (n = 2-8) are polyynic/cummulenic while all neutral Sn(m)C(n) structures (m = 3-4) could be described as small tin clusters (dimer

  18. Tin-carbon clusters and the onset of microscopic level immiscibility: Experimental and computational study

    NASA Astrophysics Data System (ADS)

    Bernstein, J.; Landau, A.; Zemel, E.; Kolodney, E.

    2015-09-01

    We report the experimental observation and computational analysis of the binary tin-carbon gas phase species. These novel ionic compounds are generated by impact of C60 - anions on a clean tin target at some kiloelectronvolts kinetic energies. Positive SnmCn+ (m = 1-12, 1 ≤ n ≤ 8) ions were detected mass spectrometrically following ejection from the surface. Impact induced shattering of the C60 - ion followed by sub-surface penetration of the resulting atomic carbon flux forces efficient mixing between target and projectile atoms even though the two elements (Sn/C) are completely immiscible in the bulk. This approach of C60 - ion beam induced synthesis can be considered as an effective way for producing novel metal-carbon species of the so-called non-carbide forming elements, thus exploring the possible onset of molecular level miscibility in these systems. Sn2C2+ was found to be the most abundant carbide cluster ion. Its instantaneous formation kinetics and its measured kinetic energy distribution while exiting the surface demonstrate a single impact formation/emission event (on the sub-ps time scale). Optimal geometries were calculated for both neutral and positively charged species using Born-Oppenheimer molecular dynamics for identifying global minima, followed by density functional theory (DFT) structure optimization and energy calculations at the coupled cluster singles, doubles and perturbative triples [CCSD(T)] level. The calculated structures reflect two distinct binding tendencies. The carbon rich species exhibit polyynic/cummulenic nature (tin end capped carbon chains) while the more stoichiometrically balanced species have larger contributions of metal-metal bonding, sometimes resulting in distinct tin and carbon moieties attached to each other (segregated structures). The Sn2Cn (n = 3-8) and Sn2Cn+ (n = 2-8) are polyynic/cummulenic while all neutral SnmCn structures (m = 3-4) could be described as small tin clusters (dimer, trimer, and tetramer

  19. Lipid extraction from microalgae using a single ionic liquid

    DOEpatents

    Salvo, Roberto Di; Reich, Alton; Dykes, Jr., H. Waite H.; Teixeira, Rodrigo

    2013-05-28

    A one-step process for the lysis of microalgae cell walls and separation of the cellular lipids for use in biofuel production by utilizing a hydrophilic ionic liquid, 1-butyl-3-methylimidazolium. The hydrophilic ionic liquid both lyses the microalgae cell walls and forms two immiscible layers, one of which consists of the lipid contents of the lysed cells. After mixture of the hydrophilic ionic liquid with a suspension of microalgae cells, gravity causes a hydrophobic lipid phase to move to a top phase where it is removed from the mixture and purified. The hydrophilic ionic liquid is recycled to lyse new microalgae suspensions.

  20. Hybrid multiphase CFD simulation for liquid-liquid interfacial area prediction in annular centrifugal contactors

    SciTech Connect

    Wardle, K.E.

    2013-07-01

    Liquid-liquid contacting equipment used in solvent extraction processes has the dual purpose of mixing and separating two immiscible fluids. Consequently, such devices inherently encompass a wide variety of multiphase flow regimes. A hybrid multiphase computational fluid dynamics (CFD) solver which combines the Eulerian multi-fluid method with VOF (volume of fluid) sharp interface capturing has been developed for application to annular centrifugal contactors. This solver has been extended to enable prediction of mean droplet size and liquid-liquid interfacial area through a single moment population balance method. Simulations of liquid-liquid mixing in a simplified geometry and a model annular centrifugal contactor are reported with droplet breakup/coalescence models being calibrated versus available experimental data. Quantitative comparison is made for two different housing vane geometries and it is found that the predicted droplet size is significantly smaller for vane geometries which result in higher annular liquid holdup.

  1. Multicomponent liquid and vapor fuel distribution measurements in the cylinder of a port-injected, spark- ignition engine

    NASA Astrophysics Data System (ADS)

    Styron, Joshua Putman

    Over the last twenty years, much of the innovation in automotive engine design has been directed towards meeting lower emissions standards as required by the federal government. Correlations used to tune engines that are based on engine-out hydrocarbon measurements alone often fail to be portable to other engine designs because the testing procedures provide little information on in-cylinder fuel/air mixing and combustion processes. A better understanding of in-cylinder processes should improve the applicability of emissions correlations, reducing the amount of engine testing required and providing additional emissions improvements. A 2.5 L, V-6, port-injected engine was modified for optical access by separating one head from the block. The engine could be fitted with one of two heads that produced either a swirling flow or a tumbling flow in the engine. An extended piston with a window in its crown rides in a transparent cylinder liner of fused silica. This arrangement is suitable for laser imaging techniques. Planar laser-induced exciplex fluorescence, which allows the simultaneous, but separate, imaging of liquid and vapor fuel, was extended to capture components of different volatilities in a model fuel designed to simulate the distillation curve of a typical gasoline. Accurate representation of both phases and more than one volatility was demonstrated to be necessary for drawing complete conclusions from fuel distribution data. The exciplex fluorescence technique was calibrated in a separate, calibration cell where careful control of mixture composition, temperature, and pressure was possible. Fluorescence was measured as a function of total pressure from 0 to 1450 kPa, temperature from 18 to 200°C, and fuel-to-air ratio from 0 to twice stoichiometric. The calibrated technique applied to the engine provided both qualitative and quantitative data for improving our understanding of in-cylinder mixing and comparison with engine simulation codes. The engine

  2. Flow and Reactive Transport of Miscible and Immiscible Solutions in Fractured & Porous Media

    NASA Astrophysics Data System (ADS)

    Ryerson, F. J.; Ezzedine, S. M.; Antoun, T.

    2012-12-01

    Miscible and immiscible flows are important phenomena encountered in many industrial and engineering applications such as hydrothermal systems, oil and gas reservoirs, salt/water intrusion, geological carbon sequestration etc… Under the influence of gravity, the flow of fluids with sufficiently large density ratios may become unstable leading to instabilities, mixing and in some instances reactions at the interfacial contact between fluids. Flow is governed by a combination of momentum and mass conservation equations that describe the flow of the fluid phase and a convection-diffusion equation describing the change of concentration in the fluid phase. When hydrodynamic instabilities develop it may be difficult to use standard grid-based methods to model miscible/immiscible flow because the domains occupied by fluids evolve constantly with time. In the current study, adaptive mesh refinement finite elements method has been used to solve for flow and transport equations. Furthermore, a particle tracking scheme has also been implemented to track the kinematics of swarm of particles injected into the porous fractured media to quantify surface area, sweeping zones, and their impact on porosity changes. Spatial and temporal moments of the fingering instabilities and the development of reaction zones and the impact of kinetic reaction at the fluid/solution interfaces have also been analyzed. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  3. Preparation and Friction Force Microscopy Measurements of Immiscible, Opposing Polymer Brushes

    PubMed Central

    de Beer, Sissi; Kutnyanszky, Edit; Müser, Martin H.; Vancso, G. Julius

    2014-01-01

    Solvated polymer brushes are well known to lubricate high-pressure contacts, because they can sustain a positive normal load while maintaining low friction at the interface. Nevertheless, these systems can be sensitive to wear due to interdigitation of the opposing brushes. In a recent publication, we have shown via molecular dynamics simulations and atomic force microscopy experiments, that using an immiscible polymer brush system terminating the substrate and the slider surfaces, respectively, can eliminate such interdigitation. As a consequence, wear in the contacts is reduced. Moreover, the friction force is two orders of magnitude lower compared to traditional miscible polymer brush systems. This newly proposed system therefore holds great potential for application in industry. Here, the methodology to construct an immiscible polymer brush system of two different brushes each solvated by their own preferred solvent is presented. The procedure how to graft poly(N-isopropylacrylamide) (PNIPAM) from a flat surface and poly(methyl methacrylate) (PMMA) from an atomic force microscopy (AFM) colloidal probe is described. PNIPAM is solvated in water and PMMA in acetophenone. Via friction force AFM measurements, it is shown that the friction for this system is indeed reduced by two orders of magnitude compared to the miscible system of PMMA on PMMA solvated in acetophenone. PMID:25590429

  4. Weak protein-protein interactions revealed by immiscible filtration assisted by surface tension.

    PubMed

    Berry, Scott M; Chin, Emily N; Jackson, Shawn S; Strotman, Lindsay N; Goel, Mohit; Thompson, Nancy E; Alexander, Caroline M; Miyamoto, Shigeki; Burgess, Richard R; Beebe, David J

    2014-02-15

    Biological mechanisms are often mediated by transient interactions between multiple proteins. The isolation of intact protein complexes is essential to understanding biochemical processes and an important prerequisite for identifying new drug targets and biomarkers. However, low-affinity interactions are often difficult to detect. Here, we use a newly described method called immiscible filtration assisted by surface tension (IFAST) to isolate proteins under defined binding conditions. This method, which gives a near-instantaneous isolation, enables significantly higher recovery of transient complexes compared to current wash-based protocols, which require reequilibration at each of several wash steps, resulting in protein loss. The method moves proteins, or protein complexes, captured on a solid phase through one or more immiscible-phase barriers that efficiently exclude the passage of nonspecific material in a single operation. We use a previously described polyol-responsive monoclonal antibody to investigate the potential of this new method to study protein binding. In addition, difficult-to-isolate complexes involving the biologically and clinically important Wnt signaling pathway were isolated. We anticipate that this simple, rapid method to isolate intact, transient complexes will enable the discoveries of new signaling pathways, biomarkers, and drug targets. PMID:24215910

  5. Generalized Cahn-Hilliard Navier-Stokes equations for numerical simulations of multicomponent immiscible flows

    NASA Astrophysics Data System (ADS)

    Li, Zhaorui; Livescu, Daniel

    2014-11-01

    By using the second-law of thermodynamics and the Onsager reciprocal method for irreversible processes, we have developed a set of physically consistent multicomponent compressible generalized Cahn-Hilliard Navier-Stokes (CGCHNS) equations from basic thermodynamics. The new equations can describe not only flows with pure miscible and pure immiscible materials but also complex flows in which mass diffusion and surface tension or Korteweg stresses effects may coexist. Furthermore, for the first time, the incompressible generalized Cahn-Hilliard Navier-Stokes (IGCHNS) equations are rigorously derived from the incompressible limit of the CGCHNS equations (as the infinite sound speed limit) and applied to the immiscible Rayleigh-Taylor instability problem. Extensive good agreements between numerical results and the linear stability theory (LST) predictions for the Rayleigh-Taylor instability are achieved for a wide range of wavenumber, surface tension, and viscosity values. The late-time results indicate that the IGCHNS equations can naturally capture complex interface topological changes including merging and breaking-up and are free of singularity problems.

  6. Matter-wave solitons in the counterflow of two immiscible superfluids

    NASA Astrophysics Data System (ADS)

    Tsitoura, F.; Achilleos, V.; Malomed, B. A.; Yan, D.; Kevrekidis, P. G.; Frantzeskakis, D. J.

    2013-06-01

    We study formation of solitons induced by counterflows of immiscible superfluids. Our setting is based on a quasi-one-dimensional binary Bose-Einstein condensate, composed of two immiscible components with large and small numbers of atoms in them. Assuming that the “small” component moves with constant velocity, either by itself, or being dragged by a moving trap, and intrudes into the “large” counterpart, the following results are obtained. Depending on the velocity, and on whether the small component moves in the absence or in the presence of the trap, two-component dark-bright solitons, scalar dark solitons, or multiple dark solitons may emerge, the last outcome taking place due to breakdown of the superfluidity. We present two sets of analytical results to describe this phenomenology. In an intermediate velocity regime, where dark-bright solitons form, a reduction of the two-component Gross-Pitaevskii system to an integrable Mel'nikov system is developed, demonstrating that solitary waves of the former are very accurately described by analytically available solitons of the latter. In the high-velocity regime, where the breakdown of the superfluidity induces the formation of dark solitons and multisoliton trains, an effective single-component description, in which a strongly localized wave packet of the “small” component acts as an effective potential for the “large” one, allows us to estimate the critical velocity beyond which the coherent structures emerge in good agreement with the numerical results.

  7. Weak protein-protein interactions revealed by immiscible filtration assisted by surface tension (IFAST)

    PubMed Central

    Berry, Scott M.; Chin, Emily N.; Jackson, Shawn S.; Strotman, Lindsay N.; Goel, Mohit; Thompson, Nancy E.; Alexander, Caroline M.; Miyamoto, Shigeki; Burgess, Richard R.; Beebe, David J.

    2013-01-01

    Biological mechanisms are often mediated by transient interactions between multiple proteins. The isolation of intact protein complexes is essential to understanding biochemical processes and an important prerequisite for identifying new drug targets and biomarkers. However, low-affinity interactions are often difficult to detect. Here, we use a newly described method called immiscible filtration assisted by surface tension (IFAST) to isolate proteins under defined binding conditions. This method, that gives a near-instantaneous isolation, enables significantly higher recovery of transient complexes as compared to current wash-based protocols, which require re-equilibration at each of several wash steps, resulting in protein loss. The method moves proteins, or protein complexes, captured on a solid phase through one or more immiscible phase barriers that efficiently exclude the passage of non-specific material in a single operation. We use a previously described polyol-responsive monoclonal antibody (PR-mAb) to investigate the potential of this new method to study protein-binding. In addition, difficult-to-isolate complexes involving the biologically and clinically important Wnt signaling pathway were isolated. We anticipate that this simple, rapid method to isolate intact, transient complexes will enable the discoveries of new signaling pathways, biomarkers, and drug targets. PMID:24215910

  8. Preparation and friction force microscopy measurements of immiscible, opposing polymer brushes.

    PubMed

    de Beer, Sissi; Kutnyanszky, Edit; Müser, Martin H; Vancso, G Julius

    2014-01-01

    Solvated polymer brushes are well known to lubricate high-pressure contacts, because they can sustain a positive normal load while maintaining low friction at the interface. Nevertheless, these systems can be sensitive to wear due to interdigitation of the opposing brushes. In a recent publication, we have shown via molecular dynamics simulations and atomic force microscopy experiments, that using an immiscible polymer brush system terminating the substrate and the slider surfaces, respectively, can eliminate such interdigitation. As a consequence, wear in the contacts is reduced. Moreover, the friction force is two orders of magnitude lower compared to traditional miscible polymer brush systems. This newly proposed system therefore holds great potential for application in industry. Here, the methodology to construct an immiscible polymer brush system of two different brushes each solvated by their own preferred solvent is presented. The procedure how to graft poly(N-isopropylacrylamide) (PNIPAM) from a flat surface and poly(methyl methacrylate) (PMMA) from an atomic force microscopy (AFM) colloidal probe is described. PNIPAM is solvated in water and PMMA in acetophenone. Via friction force AFM measurements, it is shown that the friction for this system is indeed reduced by two orders of magnitude compared to the miscible system of PMMA on PMMA solvated in acetophenone. PMID:25590429

  9. A new lattice Boltzmann model for interface reactions between immiscible fluids

    NASA Astrophysics Data System (ADS)

    Di Palma, Paolo Roberto; Huber, Christian; Viotti, Paolo

    2015-08-01

    In this paper, we describe a lattice Boltzmann model to simulate chemical reactions taking place at the interface between two immiscible fluids. The phase-field approach is used to identify the interface and its orientation, the concentration of reactant at the interface is then calculated iteratively to impose the correct reactive flux condition. The main advantages of the model is that interfaces are considered part of the bulk dynamics with the corrective reactive flux introduced as a source/sink term in the collision step, and, as a consequence, the model's implementation and performance is independent of the interface geometry and orientation. Results obtained with the proposed model are compared to analytical solution for three different benchmark tests (stationary flat boundary, moving flat boundary and dissolving droplet). We find an excellent agreement between analytical and numerical solutions in all cases. Finally, we present a simulation coupling the Shan Chen multiphase model and the interface reactive model to simulate the dissolution of a collection of immiscible droplets with different sizes rising by buoyancy in a stagnant fluid.

  10. Design concepts of a heavy-oil recovery process by an immiscible CO/sub 2/ application

    SciTech Connect

    Kantar, K.; Issever, K.; Karaoguz, D.; Vrana, L.

    1985-02-01

    Bati Raman oil field, in southeast Turkey, represents Turkey's biggest single oil reserve. The rapid production decline of the field and increases in the price of crude oil has led Turkish Petroleum Corp. (TPAO) to consider intervening with EOR techniques. Since 1967, various recovery schemes have been attempted, including steam and water injection. Extensive laboratory, modeling, and comparative engineering studies of various immiscible CO/sub 2/ application techniques resulted. This paper presents the reservoir engineering aspects of immiscible CO/sub 2/ application as applied to Bati Raman oil field.

  11. Numerical modeling of immiscible two-phase flow in micro-models using a commercial CFD code

    SciTech Connect

    Crandall, Dustin; Ahmadia, Goodarz; Smith, Duane H.

    2009-01-01

    Off-the-shelf CFD software is being used to analyze everything from flow over airplanes to lab-on-a-chip designs. So, how accurately can two-phase immiscible flow be modeled flowing through some small-scale models of porous media? We evaluate the capability of the CFD code FLUENT{trademark} to model immiscible flow in micro-scale, bench-top stereolithography models. By comparing the flow results to experimental models we show that accurate 3D modeling is possible.

  12. Reducing Sliding Friction with Liquid-Impregnated Surfaces

    NASA Astrophysics Data System (ADS)

    Habibi, Mohammad; Collier, C. Patrick; Boreyko, Jonathan; Nature Inspired Fluids; Interfaces Team; CenterNanophase Materials Sciences Team

    2015-11-01

    Liquid-impregnated surfaces are fabricated by infusing a lubricating liquid into the micro/nano roughness of a textured substrate, such that the surface is slippery for any deposited liquid immiscible with the lubricant. To date, liquid-impregnated surfaces have almost exclusively focused on repelling liquids by minimizing the contact angle hysteresis. Here, we demonstrate that liquid-impregnated surfaces are also capable of reducing sliding friction for solid objects. Ordered arrays of silicon micropillars were infused with lubricating liquids varying in viscosity by two orders of magnitude. Five test surfaces were used: two different micropillared surfaces with and without liquid infusion and a smooth, dry control surface. The static and kinetic coefficients of friction were measured using a polished aluminum cube as the sliding object. Compared to the smooth control surface, the sliding friction was reduced by at least a factor of two on the liquid-impregnated surfaces.

  13. Optical Switch Based on Shape-Deformable Liquids

    NASA Astrophysics Data System (ADS)

    Xu, Miao; Ren, Hongwen; Lee, Myong-Hyung

    2013-11-01

    We report an optical switch based on shape-deformable liquids. Two immiscible liquids are sandwiched between glass substrates. One liquid is clear and the other is black. The clear liquid forms a droplet, which presents a cylindrical shape upon touching both glass substrates. The black liquid is used to fill the space outside the droplet. The dielectric constant of the clear liquid is larger than that of the black liquid. In the voltage-off state, the cylindrical droplet opens a channel that allows incident light to pass through. When a voltage is applied to the liquids, the diameter of the channel reduces, causing the intensity of the transmitted light to decrease. In contrast to previous liquid-based optical switch devices, this device operates in the normal mode. Such a device has the advantages of easy fabrication, large variability of the aperture size, and good mechanical stability.

  14. SOLID-LIQUID PHASE TRANSFER CATALYZED SYNTHESIS OF CINNAMYL ACETATE-KINETICS AND ANALYSIS OF FACTORS AFFECTING THE REACTION IN A BATCH REACTOR

    EPA Science Inventory

    The use of solid-liquid phase transfer catalysis has an advantage of carrying out reaction between two immiscible substrates, one in solid phase and the other in liquid phase, with high selectivity and at relatively low temperatures. In this study we investigated the synthesis ci...

  15. Evaluation of the Malvern optical particle monitor. [Volumetric size distribution

    SciTech Connect

    Anderson, R. J.; Johnson, E.

    1983-07-01

    The Malvern 2200/3300 Particle Sizer is a laser-based optical particle sizing device which utilizes the principle of Fraunhofer Diffraction as the means of particle size measurement. The instrument is designed to analyze particle sizes in the range of 1 to 1800 microns diameter through a selection of lenses for the receiving optics. It is not a single-particle counter but rather an ensemble averager over the distribution of particles present in the measuring volume. Through appropriate measurement techniques, the instrument can measure the volumetric size distribution of: solids in gas or liquid suspension; liquid droplets in gas or other immiscible liquids; and, gas bubbles in liquid. (Malvern Handbook, Version 1.5). This report details a limited laboratory evaluation of the Malvern system to determine its operational characteristics, limitations, and accuracy. This investigation focused on relatively small particles in the range of 5 to 150 microns. Primarily, well characterized particles of coal in a coal and water mixture were utilized, but a selection of naturally occurring, industrially generated, and standard samples (i.e., glass beads) wer also tested. The characteristic size parameter from the Malvern system for each of these samples was compared with the results of a Coulter particle counter (Model TA II) analysis to determine the size measurement accuracy. Most of the particulate samples were suspended in a liquid media (water or isoton, plus a dispersant) for the size characterization. Specifically, the investigations contained in this report fall into four categories: (a) Sample-to-lense distance and sample concentration studies, (b) studies testing the applicability to aerosols, (c) tests of the manufacturer supplied software, and (d) size measurement comparisons with the results of Coulter analysis. 5 references, 15 figures, 2 tables.

  16. Ionic liquid mixtures--an analysis of their mutual miscibility.

    PubMed

    Omar, Salama; Lemus, Jesus; Ruiz, Elia; Ferro, Víctor R; Ortega, Juan; Palomar, Jose

    2014-03-01

    The use of ionic liquid mixtures (IL-IL mixtures) is being investigated for fine solvent properties tuning of the IL-based systems. The scarce available studies, however, evidence a wide variety of mixing behaviors (from almost ideal to strongly nonideal), depending on both the structure of the IL components and the property considered. In fact, the adequate selection of the cations and anions involved in IL-IL mixtures may ensure the absence or presence of two immiscible liquid phases. In this work, a systematic computational study of the mixing behavior of IL-IL systems is developed by means of COSMO-RS methodology. Liquid-liquid equilibrium (LLE) and excess enthalpy (H(E)) data of more than 200 binary IL-IL mixtures (including imidazolium-, pyridinium-, pyrrolidinium-, ammonium-, and phosphonium-based ILs) are calculated at different temperatures, comparing to literature data when available. The role of the interactions between unlike cations and anions on the mutual miscibility/immiscibility of IL-IL mixtures was analyzed. On the basis of proposed guidelines, a new class of immiscible IL-IL mixtures was reported, which only is formed by imidazolium-based compounds. PMID:24521179

  17. Molecular dynamics analysis of multiphase interfaces based on in situ extraction of the pressure distribution of a liquid droplet on a solid surface.

    PubMed

    Nishida, S; Surblys, D; Yamaguchi, Y; Kuroda, K; Kagawa, M; Nakajima, T; Fujimura, H

    2014-02-21

    Molecular dynamics simulations of a nanoscale liquid droplet on a solid surface are carried out in order to examine the pressure tensor field around the multiphase interfaces, and to explore the validity of Young's equation. By applying the virial theorem to a hemicylindrical droplet consisting of argon molecules on a solid surface, two-dimensional distribution of the pressure tensor is obtained. Tensile principal pressure tangential to the interface is observed around the liquid-vapor transition layer, while both tensile and compressive principal pressure tangential to the interface exists around the solid-liquid transition layer due to the inhomogeneous density distribution. The two features intermix inside the overlap region between the transition layers at the contact line. The contact angle is evaluated by using a contour line of the maximum principal pressure difference. The interfacial tensions are calculated by using Bakker's equation and Young-Laplace equation to the pressure tensor distribution. The relation between measured contact angle and calculated interfacial tensions turns out to be consistent with Young's equation, which is known as the description of the force balance at the three-phase interface. PMID:24559360

  18. Controlled and high throughput fabrication of poly(trimethylene terphthalate) nanofibers via melt extrusion of immiscible blends

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Immiscible blends of cellulose acetate butyrate (CAB) and poly(trimethylene terephthalate) (PTT) were melt extruded through a two strand rod die. The extrudates were hot-drawn at the die exit at different draw ratios. PTT fibers were obtained by removal of the CAB matrix from the drawn extrudates, a...

  19. Controlled and high throughput fabrication of poly(trimethylene terephthalate) nanofibers via melt extrusion of immiscible blends

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Immiscible blends of cellulose acetate butyrate (CAB) and poly(trimethylene terephthalate) (PTT) were melt extruded through a two strand rod die. The extrudates were hot-drawn at the die exit at different draw ratios. PTT fibers were obtained by removal of the CAB matrix from the drawn extrudates, a...

  20. Fabrication of Tunable Submicro- or Nano-structured Polyethylene Materials form Immiscible Blends with Cellulose Acetate Butyrate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Low density polyethylene (LDPE) was prepared into micro- or submicro-spheres or nanofibers via melt blending or extrusion of cellulose acetate butyrate (CAB)/LDPE immiscible blends and subsequent removal of the CAB matrix. The sizes of the PE spheres or fibers can be successfully controlled by varyi...

  1. Facile synthesis of carbon dots in an immiscible system with excitation-independent emission and thermally activated delayed fluorescence.

    PubMed

    Hou, Juan; Wang, Long; Zhang, Ping; Xu, Yuan; Ding, Lan

    2015-12-28

    Herein, we present a one-pot microwave-assisted preparative method for water-soluble carbon dots (CDs) in an immiscible system. CDs demonstrated uniform morphology, high quantum yield and excitation-independent fluorescence emission. Moreover, we first reported the observation of thermally activated delayed fluorescence from CDs. PMID:26498875

  2. Investigating the influence of production conditions on the energy distribution between the solid, liquid and gaseous products of slow pyrolysis

    NASA Astrophysics Data System (ADS)

    Crombie, Kyle; Masek, Ondrej

    2013-04-01

    Slow pyrolysis is a well established technology for converting biomass into a more stable form of carbon (biochar) while also producing energy rich by-products of bio-oil and syngas. Biochar is the porous, carbonaceous material produced by thermo-chemical treatment of organic materials in an oxygen-limited environment. Biochar can be incorporated into soils to improve soil fertility, reduce greenhouse gas emissions as well as provide long term storage of carbon or alternatively it can also provide additional energy to a pyrolysis system through combustion. Biochar production conditions have a significant influence on the yield as well as physiochemical and functional properties of the final pyrolysis products, resulting in a selection process aimed towards either agricultural benefits and carbon mitigation or heat/energy generation. This work aimed to investigate the effect of temperature, residence time and gas flow rate on the product energy distribution as well as the physical, chemical and soil functional properties of biochar, in order to optimise conditions best suited to maximise both energy value and agronomic benefit. Biochar samples were produced from wood pellets (WP) and straw pellets (SP) at two temperatures (350 and 650oC), with three residence times (10, 20 and 40 minutes) and three carrier gas flow rates (0, 0.3 and 0.6 L min-1). The energy balance of the system was determined through the calorimetric analysis of biochar and bio-oil, while the higher heating value for the syngas was calculated from the gas composition measured via mass spectroscopy. Biochar was also analysed for the physiochemical properties of proximate analysis and ultimate analysis as well as the functional property of environmentally stable carbon (C) content. As expected the yield of biochar decreased with increasing temperature resulting in elevated yields of liquid and gas fractions. Increased temperature also resulted in higher values of fixed C, total C, stable C and

  3. Automated hollow-fiber liquid-phase microextraction followed by liquid chromatography with mass spectrometry for the determination of benzodiazepine drugs in biological samples.

    PubMed

    Nazaripour, Ali; Yamini, Yadollah; Ebrahimpour, Behnam; Fasihi, Javad

    2016-07-01

    In this study, two-phase hollow-fiber liquid-phase microextraction and three-phase hollow-fiber liquid-phase microextraction based on two immiscible organic solvents were compared for extraction of oxazepam and Lorazepam. Separations were performed on a liquid chromatography with mass spectrometry instrument. Under optimal conditions, three-phase hollow-fiber liquid-phase microextraction based on two immiscible organic solvents has a better extraction efficiency. In a urine sample, for three-phase hollow fiber liquid-phase microextraction based on two immiscible organic solvents, the calibration curves were found to be linear in the range of 0.6-200 and 0.9-200 μg L(-1) and the limits of detection were 0.2 and 0.3 μg L(-1) for oxazepam and lorazepam, respectively. For two-phase hollow fiber liquid-phase microextraction, the calibration curves were found to be linear in the range of 1-200 and 1.5-200 μg L(-1) and the limits of detection were 0.3 and 0.5 μg L(-1) for oxazepam and lorazepam, respectively. In a urine sample, for three-phase hollow-fiber-based liquid-phase microextraction based on two immiscible organic solvents, relative standard deviations in the range of 4.2-4.5% and preconcentration factors in the range of 70-180 were obtained for oxazepam and lorazepam, respectively. Also for the two-phase hollow-fiber liquid-phase microextraction, preconcentration factors in the range of 101-257 were obtained for oxazepam and lorazepam, respectively. PMID:27144369

  4. Optical Feedback Interferometry for Velocity Measurement of Parallel Liquid-Liquid Flows in a Microchannel.

    PubMed

    Ramírez-Miquet, Evelio E; Perchoux, Julien; Loubière, Karine; Tronche, Clément; Prat, Laurent; Sotolongo-Costa, Oscar

    2016-01-01

    Optical feedback interferometry (OFI) is a compact sensing technique with recent implementation for flow measurements in microchannels. We propose implementing OFI for the analysis at the microscale of multiphase flows starting with the case of parallel flows of two immiscible fluids. The velocity profiles in each phase were measured and the interface location estimated for several operating conditions. To the authors knowledge, this sensing technique is applied here for the first time to multiphase flows. Theoretical profiles issued from a model based on the Couette viscous flow approximation reproduce fairly well the experimental results. The sensing system and the analysis presented here provide a new tool for studying more complex interactions between immiscible fluids (such as liquid droplets flowing in a microchannel). PMID:27527178

  5. Liquid/Gas Vortex Separator

    NASA Technical Reports Server (NTRS)

    Morris, B. G.

    1986-01-01

    Liquid/gas separator vents gas from tank of liquid that contains gas randomly distributed in bubbles. Centrifugal force separates liquid and gas, forcing liquid out of vortex tube through venturi tube. Gas vented through exhaust port. When liquid detected in vent tube, exhaust port closed, and liquid/gas mixture in vent tube drawn back into tank through venturi.

  6. Characterizing the Use of Ultrasonic Energy in Promoting Uniform Composite Growth in Immiscible Alloys

    NASA Technical Reports Server (NTRS)

    Grugel, Richard N.; Fedoseyev, A. I.

    2000-01-01

    The results of experimental investigation and mathematical modeling for immiscible alloys subjected to ultrasonic influence are presented. It is known that in inoculated light alloy melts, ultrasonic treatment creates a new type of cast structure with extremely fine grains of uniform composition. This effect is produced across a wide range of freezing rates and technologies. However, it has not been demonstrated that the process can be successfully applied during controlled directional solidification processing. In this work we present the results from a set of directional solidification experiments and suggest describing the droplet size versus ultrasonic frequency and amplitude using an energy approach, followed with a more detailed analysis through numerical modeling of the ultrasonic field.

  7. Interface pinning of immiscible gravity-exchange flows in porous media

    NASA Astrophysics Data System (ADS)

    Zhao, Benzhong; MacMinn, Christopher W.; Szulczewski, Michael L.; Neufeld, Jerome A.; Huppert, Herbert E.; Juanes, Ruben

    2013-02-01

    We study the gravity-exchange flow of two immiscible fluids in a porous medium and show that, in contrast with the miscible case, a portion of the initial interface remains pinned at all times. We elucidate, by means of micromodel experiments, the pore-level mechanism responsible for capillary pinning at the macroscale. We propose a sharp-interface gravity-current model that incorporates capillarity and quantitatively explains the experimental observations, including the x˜t1/2 spreading behavior at intermediate times and the fact that capillarity stops a finite-release current. Our theory and experiments suggest that capillary pinning is potentially an important, yet unexplored, trapping mechanism during CO2 sequestration in deep saline aquifers.

  8. Modeling of Two-Phase Immiscible Flow with Moving Contact Lines

    NASA Astrophysics Data System (ADS)

    Abu Alsaud, Moataz; Soulaine, Cyprien; Riaz, Amir; Tchelepi, Hamdi; Stanford University Collaboration; University of Maryland, College Park Collaboration

    2015-11-01

    A new numerical method based on the implicit interface approach on Cartesian grids is proposed for modeling two-phase immiscible flow with moving contact lines. The reinitialization of level-set function by computing the minimum distance to linearly reconstructed interface to obtain signed distance function is extended to include the contact angle boundary condition. The physics of contact line dynamics is implemented using the Cox-Voinov hydrodynamic theory that efficiently captures the effect of the microscopic contact line region. The numerical method is validated through various examples. Parasitic currents are studied in the case of static and constantly advected parabolic interface intersecting the domain boundary with an imposed contact angle. Moving contact line in the viscous dominated regime is studied and verified through comparison with experiments.

  9. Stochastic growth dynamics and composite defects in quenched immiscible binary condensates

    NASA Astrophysics Data System (ADS)

    Liu, I.-K.; Pattinson, R. W.; Billam, T. P.; Gardiner, S. A.; Cornish, S. L.; Huang, T.-M.; Lin, W.-W.; Gou, S.-C.; Parker, N. G.; Proukakis, N. P.

    2016-02-01

    We study the sensitivity of coupled condensate formation dynamics on the history of initial stochastic domain formation in the context of instantaneously quenched elongated harmonically trapped immiscible two-component atomic Bose gases. The spontaneous generation of defects in the fastest condensing component, and subsequent coarse-graining dynamics, can lead to a deep oscillating microtrap into which the other component condenses, thereby establishing a long-lived composite defect in the form of a dark-bright solitary wave. We numerically map out diverse key aspects of these competing growth dynamics, focusing on the role of shot-to-shot fluctuations and global parameter changes (initial state choices, quench parameters, and condensate growth rates), with our findings also qualitatively confirmed by realistic finite-duration quenches. We conclude that phase-separated structures observable on experimental time scales are likely to be metastable states whose form is influenced by the stability and dynamics of the spontaneously emerging dark-bright solitary wave.

  10. Analysis of heavy-oil immiscible CO/sub 2/ tertiary coreflood data

    SciTech Connect

    Mayer, E.H.; Earlougher, R.C. Sr.; Spivak, A.; Costa, A.

    1988-02-01

    This paper describes the results of a series of tertiary, immiscible, CO/sub 2/ corefloods of Wilmington field Pliocene reservoir rock containing heavy oil (+- 14/sup 0/ API (+-0.97 g/cm/sup 3/) and +-480 cp (+-480 mPa . s)). An initial set of corefloods defined the recovery potential of the CO/sub 2/ injection, while a series of later tests served to define the process more accurately as applied in the field. In an attempt to understand the displacement mechanism, simulator matching of one of the later, more refined groups of corefloods was performed. The corefloods and simulator work indicate that the incremental recovery is more than can be accounted for by oil-viscosity reduction and crude-oil swelling. The improved performance is attributed to more favorable displacement characteristics and the presence of a free gas saturation in the cores.

  11. Immiscible fluids (CO 2-brines) in optical fluorite, Nordvik-Taimyr, Russia

    NASA Astrophysics Data System (ADS)

    Prokof'ev, Vsevolod Y.; Baksheev, Ivan A.; Korytov, Feodor Y.; Touret, Jacques

    2006-07-01

    Fluid inclusion investigations in optical fluorite from the Nordvik salt dome caprock (Khatanga Gulf, Taimyr Peninsula, Russia) show that the fluorite has been formed at a temperature of about 300 °C, from CO 2-brine immiscible hydrothermal fluids. Unmixing occurred at a depth of several kilometres, resulting in the liberation of dense CO 2-rich fluids, which played a significant role in helping the diapir to reach its intrusive character. Compared to other optical fluorite deposits in Russia, the exceptional quality of the Nordvik occurrence is due to a relatively high formation temperature, as well as a high salinity (30-35 wt% NaCl eq.) of hydrothermal aqueous fluids. To cite this article: V.Y. Prokof'ev et al., C. R. Geoscience 338 (2006).

  12. Flux-dependent percolation transition in immiscible two-phase flows in porous media.

    PubMed

    Ramstad, Thomas; Hansen, Alex; Oren, Pål-Eric

    2009-03-01

    Using numerical simulations, we study immiscible two-phase flow in a pore network reconstructed from Berea sandstone under flow conditions that are statistically invariant under translation. Under such conditions, the flow is a state function which is not dependent on initial conditions. We find a second-order phase transition resembling the phase inversion transition found in emulsions. The flow regimes under consideration are those of low surface tension-hence high capillary numbers Ca-where viscous forces dominate. Nevertheless, capillary forces are imminent, we observe a critical stage in saturation where the transition takes place. We determine polydispersity critical exponent tau=2.27+/-0.08 and find that the critical saturation depends on how fast the fluids flow. PMID:19392052

  13. Generalization of the DLA process with different immiscible components by time-scale coarse graining

    NASA Astrophysics Data System (ADS)

    Postnikov, E. B.; Ryabov, A. B.; Loskutov, A.

    2007-10-01

    In the framework of the mean-field approximation we propose a new approach to the description of the growth of fractal structures which are formed as a result of the process of diffusion limited aggregation. Our approach is based on the coarse graining of the time scale which takes into account the property of discreteness of such structures. The obtained system of partial differential equations allows us to evaluate numerically the fractal dimension and the cluster density depending on the distance from the cluster center. The results are in a quite good agreement with values found by the direct numerical simulations. The proposed approach is generalized for the case of the cluster description with different immiscible particles.

  14. Fluid-fluid interaction during miscible and immiscible displacement under ultrasonic waves

    NASA Astrophysics Data System (ADS)

    Hamida, T.; Babadagli, T.

    2007-12-01

    This paper aims at identifying and analyzing the influence of high-frequency, high-intensity ultrasonic radiation at the interface between immiscible (different types of oils and aqueous solutions) and miscible (different types of oil and solvent) fluids. An extensive set of Hele-Shaw type experiments were performed for several viscosity ratios, and interfacial tension. Fractal analysis techniques were applied to quantify the degree of fingering and branching. This provided a rough assessment of the degree of perturbation generated at the interface when the capillary forces along with the viscous forces are effective. Miscible Hele-Shaw experiments were also presented to isolate the effect of viscous forces. We found that ultrasound acts to stabilize the interfacial front, and that such effect is most pronounced at low viscosity ratios.

  15. A Three-dimensional Numerical Study of Immiscible Droplet Deformation in a right angle bend

    NASA Astrophysics Data System (ADS)

    Kumar, Purushotam; Horwitz, Jeremy; Vanka, Surya

    2013-11-01

    We present a numerical study of deformation of an immiscible droplet in a right angle bend. We have used volume-of-fluid method to track the interface and variable density Navier-Stokes equations to solve for the flow field. A second-order accurate fractional step algorithm is used to integrate the equations. The VOF is also coupled to a level-set method to get a smoothed interface shape for surface tension calculations. We study the effects of density and viscosity ratios (between droplet and carrier fluids), Reynolds number, Capillary number and aspect ratio between droplet and duct size on the deformation characteristics. We investigate the elongation of the droplet in axial direction and the stretching or contraction of the droplet in the lateral direction. Depending on the value of above mentioned parameters droplet can take different shapes, namely, spherical, bullet and parachute. At moderately higher Reynolds numbers we also observe satellite droplet breaking from the original droplet.

  16. The evolution of immiscible silicate and fluoride melts: Implications for REE ore-genesis

    NASA Astrophysics Data System (ADS)

    Vasyukova, O.; Williams-Jones, A. E.

    2016-01-01

    The Mid-Proterozoic peralkaline Strange Lake pluton (Québec-Labrador, Canada) exhibits extreme enrichment in high field strength elements (HFSE), including the rare earth elements (REE), particularly in pegmatites. On the basis of a study of melt inclusions, we proposed recently that fluoride-silicate melt immiscibility played an important and perhaps dominant role in concentrating the REE within the pluton. Here we present further evidence for silicate-fluoride immiscibility at Strange Lake from a sample of the hypersolvus granite, which contains an inclusion composed largely of REE and HFSE minerals. The inclusion (∼5 cm in diameter) comprises a narrow rim containing chevkinite-(Ce) and zircon in a fluorite matrix, a core of fluorbritholite-(Ce) and bastnäsite-(Ce) and a transition zone between the rim and the core consisting of a fine-grained intergrowth of bastnäsite-(Ce), gagarinite-(Y) and fluorite. We propose that the inclusion formed as a result of silicate-fluoride immiscibility, which occurred early in the emplacement history of the Strange Lake pluton, and that it represents the fluoride melt. After separation of the two melts, the boundary between them acted as a locus of crystallisation, where crystals formed repeatedly due to heterogeneous (surface catalysed) nucleation. Zircon crystallised shortly after melt phase separation, and was followed by the growth of perthite together with arfvedsonite and quartz. As a result, the silicate melt surrounding the fluoride inclusion became enriched in volatiles that facilitated crystallisation of progressively larger crystals in the inclusion; large crystals of arfvedsonite and perthite were succeeded by even larger crystals of quartz. Massive crystallisation of chevkinite-(Ce) followed, forming the rim of the inclusion. The fluoride melt, which constituted the matrix to the silicate minerals and chevkinite-(Ce), crystallised after chevkinite-(Ce), forming fluorbritholite-(Ce) and fluorite. Aqueous fluid

  17. Smoothed Particle Hydrodynamics pore-scale simulations of unstable immiscible flow in porous media

    SciTech Connect

    Bandara, Dunusinghe Mudiyanselage Uditha C.; Tartakovsky, Alexandre M.; Oostrom, Martinus; Palmer, Bruce J.; Grate, Jay W.; Zhang, Changyong

    2013-12-01

    We have conducted a series of high-resolution numerical experiments using the Pair-Wise Force Smoothed Particle Hydrodynamics (PF-SPH) multiphase flow model. First, we derived analytical expressions relating parameters in the PF-SPH model to the surface tension and static contact angle. Next, we used the model to study viscous fingering, capillary fingering, and stable displacement of immiscible fluids in porous media for a wide range of capillary numbers and viscosity ratios. We demonstrated that the steady state saturation profiles and the boundaries of viscous fingering, capillary fingering, and stable displacement regions compare favorably with micromodel laboratory experimental results. For displacing fluid with low viscosity, we observed that the displacement pattern changes from viscous fingering to stable displacement with increasing injection rate. When a high viscosity fluid is injected, transition behavior from capillary fingering to stable displacement occurred as the flow rate was increased. These observation also agree with the results of the micromodel laboratory experiments.

  18. Seismoelectric couplings in a poroelastic material containing two immiscible fluid phases

    NASA Astrophysics Data System (ADS)

    Jardani, A.; Revil, A.

    2015-08-01

    A new approach of seismoelectric imaging has been recently proposed to detect saturation fronts in which seismic waves are focused in the subsurface to scan its heterogeneous nature and determine saturation fronts. Such type of imaging requires however a complete modelling of the seismoelectric properties of porous media saturated by two immiscible fluid phases, one being usually electrically insulating (for instance water and oil). We combine an extension of Biot dynamic theory, valid for porous media containing two immiscible Newtonian fluids, with an extension of the electrokinetic theory based on the notion of effective volumetric charge densities dragged by the flow of each fluid phase. These effective charge densities can be related directly to the permeability and saturation of each fluid phase. The coupled partial differential equations are solved with the finite element method. We also derive analytically the transfer function connecting the macroscopic electrical field to the acceleration of the fast P wave (coseismic electrical field) and we study the influence of the water content on this coupling. We observe that the amplitude of the co-seismic electrical disturbance is very sensitive to the water content with an increase in amplitude with water saturation. We also investigate the seismoelectric conversions (interface effect) occurring at the water table. We show that the conversion response at the water table can be identifiable only when the saturation contrasts between the vadose and saturated zones are sharp enough. A relatively dry vadose zone represents the best condition to identify the water table through seismoelectric measurements. Indeed, in this case, the coseismic electrical disturbances are vanishingly small compared to the seismoelectric interface response.

  19. An Experimental Study on the Influence of Viscosity Ratio During Immiscible Displacements in Porous Media

    NASA Astrophysics Data System (ADS)

    Durant, K. A.; Duchateau, C.; Kovscek, A. R.

    2012-12-01

    Geological sequestration in saline aquifers is a process that reduces carbon dioxide emissions and has become increasingly significant because it may help to mitigate global climate change and enhance energy sustainability. Understanding the flow behavior and stability of partially miscible fluids - such as carbon dioxide and water - in porous media is the main goal of this research. Additionally, prediction of unstable flows in porous media presents an ongoing challenge for engineers and scientists; therefore, this research also has positive implications in areas such as enhanced oil recovery and the development of chemical reactors. In order to improve the knowledge base of this intricate problem, stability and flow characteristics must be examined experimentally in three ways: (i) immiscible flows in homogeneous porous media, (ii) effects of heterogeneity, and (iii) the impact of partial miscibility of the fluids. This study focused specifically on immiscible flows and was accomplished by saturating a 2-D homogeneous, silicon-etched micromodel with UV sensitive dyed water and subsequently injecting heptane to displace the water. Heptane is more viscous than carbon dioxide; therefore various concentrations of glycerin were added to the aqueous phase to alter the viscosity ratio so that the heptane-water displacement in the micromodel was comparable to the carbon dioxide-water displacement in an aquifer. As the heptane moved through the micromodel, a high-speed camera system imaged the gradual displacement changes, seen due to the color changes in the UV dyed water. The extent of fingering in the micromodel is the physical characteristic used to determine stability. It is found that high flow rates and glycerin concentrations cause viscous fingering while low flow rates and glycerin concentrations result in capillary fingering.

  20. Molecular dynamics study on effect of elongational flow on morphology of immiscible mixtures

    NASA Astrophysics Data System (ADS)

    Tran, Chau; Kalra, Vibha

    2014-04-01

    We studied the effect of elongational flow on structure and kinetics of phase separation in immiscible blends using molecular dynamics simulations. Two different blend systems have been investigated—binary blend of polymers and binary mixture of molecular fluids. The interaction potential parameters in both material systems were chosen to ensure complete phase-separation in equilibrium. We found that elongational flow, beyond a certain rate, significantly alters the steady state morphology in such immiscible mixtures. For the case of polymer blends, perpendicular lamellar morphology was formed under elongation rates (dot \\varepsilon) from 0.05 to 0.5 MD units possibly due to the interplay of two opposing phenomena—domain deformation/rupture under elongation and aggregation of like-domains due to favorable energetic interactions. The elongation timescale at the critical rate of transition from phase-separated to the lamellar structure (dot \\varepsilon = 0.05) was found to be comparable to the estimated polymer relaxation time, suggesting a cross-over to the elongation/rupture-dominant regime. Under strong elongational flow rate, dot \\varepsilon > 0.5, the formation of disordered morphology was seen in polymer blend systems. The kinetics of phase separation was monitored by calculating domain size as a function of time for various elongational flow rates. The domain growth along the vorticity-axis was shown to follow a power law, Rz(t) ˜ t α. A growth exponent, α of 1/3 for the polymer blend and 0.5-0.6 for the fluid molecular mixture was found under elongation rates from 0.005 to 0.1. The higher growth exponent in the fluid mixture is a result of its faster diffusion time scale compared to that of polymer chains. The steady state end-to-end distance of polymer chains and viscosity of the polymer blend were examined and found to depend on the steady state morphology and elongation rate.

  1. Molecular dynamics study on effect of elongational flow on morphology of immiscible mixtures.

    PubMed

    Tran, Chau; Kalra, Vibha

    2014-04-01

    We studied the effect of elongational flow on structure and kinetics of phase separation in immiscible blends using molecular dynamics simulations. Two different blend systems have been investigated-binary blend of polymers and binary mixture of molecular fluids. The interaction potential parameters in both material systems were chosen to ensure complete phase-separation in equilibrium. We found that elongational flow, beyond a certain rate, significantly alters the steady state morphology in such immiscible mixtures. For the case of polymer blends, perpendicular lamellar morphology was formed under elongation rates (ε̇) from 0.05 to 0.5 MD units possibly due to the interplay of two opposing phenomena-domain deformation/rupture under elongation and aggregation of like-domains due to favorable energetic interactions. The elongation timescale at the critical rate of transition from phase-separated to the lamellar structure (ε̇ = 0.05) was found to be comparable to the estimated polymer relaxation time, suggesting a cross-over to the elongation/rupture-dominant regime. Under strong elongational flow rate, ε̇ > 0.5, the formation of disordered morphology was seen in polymer blend systems. The kinetics of phase separation was monitored by calculating domain size as a function of time for various elongational flow rates. The domain growth along the vorticity-axis was shown to follow a power law, Rz(t) ∼ t( α). A growth exponent, α of 1/3 for the polymer blend and 0.5-0.6 for the fluid molecular mixture was found under elongation rates from 0.005 to 0.1. The higher growth exponent in the fluid mixture is a result of its faster diffusion time scale compared to that of polymer chains. The steady state end-to-end distance of polymer chains and viscosity of the polymer blend were examined and found to depend on the steady state morphology and elongation rate. PMID:24712811

  2. Immiscible Hydrocarbon and Aqueous Fluids Under Subduction Zone Conditions and Implications for the Deep Carbon Cycle

    NASA Astrophysics Data System (ADS)

    Huang, F.; Daniel, I.; Cardon, H.; Montagnac, G.; Sverjensky, D. A.

    2015-12-01

    Subducting slabs recycle rocks into the deep Earth releasing fluids which may cause partial melting and possible oxidation of the mantle wedge. Recent theoretical studies1 indicate that at pressures greater than about 3.0 GPa these fluids could contain high concentrations of organic and inorganic C-species with a wide range of C-oxidation states at equilibrium. If so, such fluids could play an important role in the deep carbon cycle, including the formation of diamond. However, direct experimental observations of the speciation in the fluids are needed. We studied 1.0 M aqueous Na-formate and 1.0 M Na-acetate solutions in the diamond anvil cell using Raman spectroscopy at 300 ºC and 3.0 GPa for up to 60 hours. Our preliminary results indicate that formate rapidly decomposed to bicarbonate/carbonate species and methane, with no detectable H2. Acetate decomposed much more slowly. Within the first two hours of heating, crystals of Na2CO3 precipitated in the fluid, and kept growing while immiscible droplets of hydrocarbon appeared and persisted throughout the experiments at elevated temperature and pressure. In the aqueous fluid, acetate and HCO3- were present during the first 6 hours, and then CO32- and acetate after 20 hours of heating. The final HCO3- /CO32- ratio was constant indicating a constant pH. This is the first in situ observation of persistent immiscible fluid hydrocarbons formed from an aqueous precursor at upper mantle pressures. Our results suggest that Earth's subduction zone fluids at high pressures might involve fluid hydrocarbon species as well as inorganic and organic aqueous C-species, which considerably broadens the picture of deep carbon sources, cycles and sinks. [1] Sverjensky et at. (2014), Nat. Geosci. 7, 909-913.

  3. Transport of microspheres across liquid-liquid interfaces

    NASA Astrophysics Data System (ADS)

    Hardt, Steffen; Sinha, Ashok; Mollah, Amlan; Ganguly, Ranjan

    2013-11-01

    Experiments with magnetic microspheres crossing the interface between two immiscible polymer solutions under the influence of a magnetic field are reported. The liquids form a bilaminated configuration in a microchannel, allowing a detailed inspection of the liquid-liquid interface. The trajectories of the particles close to the interface are examined using bright-field microscopy and a high-speed camera. During the interaction phase the interface gets deformed and the particles ``snap in,'' indicating that a three-phase contact line is formed. The dependence of the particle-interface interaction on the size of the microspheres is studied, showing that via transfer across a liquid-liquid interface a size separation of particles can be achieved. Comparing the results for 1.29 micron diameter spheres with those for 4.69 micron spheres, it is found that the small particles are able to cross the interface more easily than what is expected from a simple scaling analysis taking into account the balance between magnetic and interfacial forces on the particles. The most likely explanation for this phenomenon involves the line tension that destabilizes smaller particles adsorbed to a liquid-liquid interface more than larger particles.

  4. Storage temperature affects distribution of carbon, VFA, ammonia, phosphorus, copper and zinc in raw pig slurry and its separated liquid fraction.

    PubMed

    Popovic, Olga; Jensen, Lars Stoumann

    2012-08-01

    Chemical-mechanical separation of pig slurry into a solid fraction rich in dry matter, P, Cu and Zn and a liquid fraction rich in inorganic N but poor in dry matter may allow farmers to manage surplus slurry by exporting the solid fraction to regions with no nutrient surplus. Pig slurry can be applied to arable land only in certain periods during the year, so it is commonly stored prior to field application. This study investigated the effect of storage duration and temperature on chemical characteristics and P, Cu and Zn distribution between particle size classes of raw slurry and its liquid separation fraction. Dry matter, VFA, total N and ammonium content of both slurry products decreased during storage and were affected by temperature, showing higher losses at higher storage temperatures. In both products, total P, Cu and Zn concentrations were not significantly affected by storage duration or temperature. Particle size distribution was affected by slurry separation, storage duration and temperature. In raw slurry, particles larger than 1 mm decreased, whereas particles 250 μm-1 mm increased. The liquid fraction produced was free of particles >500 μm, with the highest proportions of P, Cu and Zn in the smallest particle size class (<25 μm). The proportion of particles <25 μm increased when the liquid fraction was stored at 5 °C, but decreased at 25 °C. Regardless of temperature, distribution of P, Cu and Zn over particle size classes followed a similar pattern to dry matter. PMID:22591817

  5. Numerical investigation of droplet motion in rotating viscous liquid flow

    NASA Astrophysics Data System (ADS)

    Arkhipov, V. A.; Tkachenko, A. S.; Usanina, A. S.

    2013-05-01

    The results of numerical investigation of the motion of a single droplet in a twisted flow of immiscible viscous liquid are presented. The motion trajectories of a droplet depending on its size, angular velocity of liquid rotation, and the physical parameters of the liquid and droplet have been determined. The values of the Reynolds, Bond, and Weber numbers along the droplet trajectory have been calculated. The effect of the Coriolis forces on the trajectory, velocity, and acceleration of the droplet in flow have been analyzed. The effect of the acceleration components of the droplet on the parameters of its motion is estimated. The numerical results are compared with experimental data.

  6. Method for removing organic liquids from aqueous solutions and mixtures

    DOEpatents

    Hrubesh, Lawrence W.; Coronado, Paul R.; Dow, Jerome P.

    2004-03-23

    A method for removing organic liquids from aqueous solutions and mixtures. The method employs any porous material preferably in granular form and having small pores and a large specific surface area, that is hydrophobic so that liquid water does not readily wet its surface. In this method, organics, especially organic solvents that mix with and are more volatile than water, are separated from aqueous solution by preferentially evaporating across the liquid/solid boundary formed at the surfaces of the hydrophobic porous materials. Also, organic solvents that are immiscible with water, preferentially wet the surfaces of the hydrophobic material and are drawn within the porous materials by capillary action.

  7. Spectroscopic measurements of the electron number density, electron temperature and OH(A) rotational distribution in a liquid electrode dielectric barrier discharge

    NASA Astrophysics Data System (ADS)

    Krähling, Tobias; Geisler, Sebastian; Okruss, Michael; Florek, Stefan; Franzke, Joachim

    2015-12-01

    The electron temperature and number density as well as the OH(A) rotational distribution of a discharge with flowing liquid electrode and dielectric barrier coupling (a liquid electrode dielectric barrier discharge, LE-DBD) were investigated by means of optical emission spectroscopy. By using the Stark broadening of three Strontium lines, the electron number density Ne and the lower bound of the electron temperature Te can be simultaneously measured. The values obtained were Ne = (0.8 - 1.6) × 1016 cm- 3 and Te > 1.1 eV, respectively. The OH(A) rotational distribution deviates from equilibrium and can be described by a superposition of two Boltzmann distributions with T1 = (3230 ± 90) K for K ' ≤ 15 and T2 = (7300 ± 300) K for K ' ≥ 16. Consideration of the formation mechanisms of OH(A) and reaction rates suggests that the dissociative recombination of H2O+ and H3O+ is responsible for the higher rotational state distribution, where these ions can only be produced in the LE-DBD through an electrospray-like process.

  8. Low-temperature liquid-liquid extraction of phenols from aqueous solutions with hydrophilic mixtures of extractants

    NASA Astrophysics Data System (ADS)

    Rudakov, O. B.; Khorokhordina, E. A.; Preobrazhenskii, M. A.; Rudakova, L. V.

    2016-08-01

    The volume ratios in acetonitrile-ethyl acetate (90 : 10, 95 : 5), acetonitrile-isopropanol-ethyl acetate (70 : 15 : 15, 80 : 5 : 15), and isopropanol-1-butanol (50 : 50) mixtures were determined. Their mixing with water (1 : 1) and storage at-10°C led to partitioning into two immiscible liquid phases without formation of the ice phase. The mixtures were shown to be useful as hydrophilic extractants in low-temperature liquidliquid extraction of phenol from aqueous solutions.

  9. Comparison of Internal Energy Distributions of Ions Created by Electrospray Ionization and Laser Ablation-Liquid Vortex Capture-Electrospray Ionization

    DOE PAGESBeta

    Cahill, John F.; Kertesz, Vilmos; Ovchinnikova, Olga S.; Van Berkel, Gary J.

    2015-06-27

    Recently a number of techniques have combined laser ablation with liquid capture for mass spectrometry spot sampling and imaging applications. The newly developed non-contact liquid-vortex capture probe has been used to efficiently collect 355 nm UV laser ablated material in a continuous flow solvent stream in which the captured material dissolves and then undergoes electrospray ionization. This sampling and ionization approach has produced what appear to be classic electrospray ionization spectra; however, the softness of this sampling/ionization process versus simple electrospray ionization has not been definitely determined. A series of benzlypyridinium salts, known as thermometer ions, were used to comparemore » internal energy distributions between electrospray ionization and the UV laser ablation liquid-vortex capture probe electrospray combination. Measured internal energy distributions were identical between the two techniques, even with differences in laser fluence (0.7-3.1 J cm-2) and when using UV-absorbing or non-UV-absorbing sample substrates. This data indicates ions formed directly by UV laser ablation, if any, are likely an extremely small constituent of the total ion signal observed. Instead, neutral molecules, clusters or particulates ejected from the surface during laser ablation, subsequently captured and dissolved in the flowing solvent stream then electrosprayed are the predominant source of ion signal observed. The electrospray ionization process used controls the softness of the technique.« less

  10. Comparison of Internal Energy Distributions of Ions Created by Electrospray Ionization and Laser Ablation-Liquid Vortex Capture-Electrospray Ionization

    SciTech Connect

    Cahill, John F.; Kertesz, Vilmos; Ovchinnikova, Olga S.; Van Berkel, Gary J.

    2015-06-27

    Recently a number of techniques have combined laser ablation with liquid capture for mass spectrometry spot sampling and imaging applications. The newly developed non-contact liquid-vortex capture probe has been used to efficiently collect 355 nm UV laser ablated material in a continuous flow solvent stream in which the captured material dissolves and then undergoes electrospray ionization. This sampling and ionization approach has produced what appear to be classic electrospray ionization spectra; however, the softness of this sampling/ionization process versus simple electrospray ionization has not been definitely determined. A series of benzlypyridinium salts, known as thermometer ions, were used to compare internal energy distributions between electrospray ionization and the UV laser ablation liquid-vortex capture probe electrospray combination. Measured internal energy distributions were identical between the two techniques, even with differences in laser fluence (0.7-3.1 J cm-2) and when using UV-absorbing or non-UV-absorbing sample substrates. This data indicates ions formed directly by UV laser ablation, if any, are likely an extremely small constituent of the total ion signal observed. Instead, neutral molecules, clusters or particulates ejected from the surface during laser ablation, subsequently captured and dissolved in the flowing solvent stream then electrosprayed are the predominant source of ion signal observed. The electrospray ionization process used controls the softness of the technique.

  11. Silymarin in liposomes and ethosomes: pharmacokinetics and tissue distribution in free-moving rats by high-performance liquid chromatography-tandem mass spectrometry.

    PubMed

    Chang, Li-Wen; Hou, Mei-Ling; Tsai, Tung-Hu

    2014-12-01

    The aim of this study was to prepare silymarin formulations (silymarin entrapped in liposomes and ethosomes, formulations referred to as LSM and ESM, respectively) to improve oral bioavailability of silymarin and evaluate its tissue distribution by liquid chromatography with tandem mass spectrometry (LC-MS/MS) in free-moving rats. Silibinin is the major active constituent of silymarin, which is the main component to be analyzed. A rapid, sensitive, and repeatable LC-MS/MS method was developed and validated in terms of precision, accuracy, and extraction recovery. Furthermore, the established method was applied to study the pharmacokinetics and tissue distribution of silymarin in rats. The size, ζ potential, and drug release of the formulations were characterized. These results showed that the LSM and ESM encapsulated formulations of silymarin may provide more efficient tissue distribution and increased oral bioavailability, thus improving its therapeutic bioactive properties in the body. PMID:25375210

  12. Displacement of nonwetting liquids from unsaturated sands by water infiltration

    SciTech Connect

    Boley, T.M.; Overcamp, T.J.

    1998-09-01

    Accidental spills of nonwetting or nonaqueous phase liquids (NAPLs) onto land can lead to ground water contamination. Once a spill has occurred, liquid infiltrates downward under the influence of gravity. As the infiltration continues, capillary forces retain a portion of the immiscible liquid within the pore spaces. After infiltration ceases, the liquid remaining within the pores is termed the residual liquid, which is frequently expressed as a percentage of the total pore volume. The quantity of residual liquid retained depends on soil and liquid properties. Xylene was spilled onto moist glass beads or various moist sands and water was trickled onto the columns every eight hours for periods up to 10 days. The xylene residual in the columns with water infiltration decreased compared to those of control columns, indicating a downward displacement of xylene. The extent of displacement increased with increasing size of the porous media and with increasing amounts of water infiltration.

  13. Preliminary drop-tower experiments on liquid-interface geometry in partially filled containers at zero gravity

    NASA Technical Reports Server (NTRS)

    Smedley, G.

    1990-01-01

    Plexiglass containers with rounded trapezoidal cross sections were designed and built to test the validity of Concus and Finn's existence theorem (1974, 1983) for a bounded free liquid surface at zero gravity. Experiments were carried out at the NASA Lewis two-second drop tower. Dyed ethanol-water solutions and three immiscible liquid pairs, with one liquid dyed, were tested. High-speed movies were used to record the liquid motion. Liquid rose to the top of the smaller end of the containers when the contact angle was small enough, in agreement with the theory. Liquid interface motion demonstrated a strong dependence on physical properties, including surface roughness and contamination.

  14. Comparison of Internal Energy Distributions of Ions Created by Electrospray Ionization and Laser Ablation-Liquid Vortex Capture/Electrospray Ionization

    NASA Astrophysics Data System (ADS)

    Cahill, John F.; Kertesz, Vilmos; Ovchinnikova, Olga S.; Van Berkel, Gary J.

    2015-09-01

    Recently a number of techniques have combined laser ablation with liquid capture for mass spectrometry spot sampling and imaging applications. The newly developed noncontact liquid-vortex capture probe has been used to efficiently collect material ablated by a 355 nm UV laser in a continuous flow solvent stream in which the captured material dissolves and then undergoes electrospray ionization. This sampling and ionization approach has produced what appears to be classic electrospray ionization spectra; however, the `softness' of this sampling/ionization process versus simple electrospray ionization has not been definitely determined. In this work, a series of benzylpyridinium salts were employed as thermometer ions to compare internal energy distributions between electrospray ionization and the UV laser ablation/liquid-vortex capture probe electrospray combination. Measured internal energy distributions were identical between the two techniques, even with differences in laser fluence (0.7-3.1 J cm-2) and when using UV-absorbing or non-UV-absorbing sample substrates. These data, along with results from the analysis the biological molecules bradykinin and angiotensin III indicated that the ions or their fragments formed directly by UV laser ablation that survive the liquid capture/electrospray ionization process were likely to be an extremely small component of the total ion signal observed. Instead, the preponderate neutral molecules, clusters, and particulates ejected from the surface during laser ablation, subsequently captured and dissolved in the flowing solvent stream, then electrosprayed, were the principal source of the ion signal observed. Thus, the electrospray ionization process used controls the overall `softness' of this technique.

  15. a Study of Liquid - of Atomization Droplet Size Velocity and Temperature Distribution via Information Theory Spray Interaction with Ambient Air Motion.

    NASA Astrophysics Data System (ADS)

    Li, Xianguo

    Linear temporal instability analysis of a moving thin viscous liquid sheet of uniform thickness in an inviscid gas medium shows that surface tension always opposes, while surrounding gas and relative velocity between the sheet and gas favour the onset and development of instability. For gas Weber number smaller than the density ratio of gas to liquid, liquid viscosity enhances instability; If gas Weber number is slightly larger, aerodynamic and viscosity -induced instabilities interact with each other, displaying complicated effects of viscosity via Ohnesorge number; For much larger values of gas Weber numbers, aerodynamic instability dominates, liquid viscosity reduces disturbance growth rate and increases the dominant wavelength. Droplet probability distribution function (PDF) in sprays is formulated through information theory without resorting to the details of atomization processes. The derived analytical droplet size PDF is Nukiyama-Tanasawa type if conservation of mass is considered alone. If conservation of mass, momentum and energy is all taken into account, the joint droplet size and velocity PDF depends on Weber number, and compares favourably with measurements. Droplet velocity PDF is truncated Gaussian for any specific droplet size. Mean velocity approaches a constant value and velocity variance decreases as droplet size increases. Mean droplet diameters calculated agree well with observations. The computation indicates that atomization efficiency is very low, usually less than 1%. Droplet size, velocity and temperature PDF in sprays under combusting environment has also been derived. Effects of combustion on PDF occur mainly through the heat transferred into liquid sheet prior to its breakup. Experimental studies identify three modes of spray behaviours due to its interaction with various annular air flows, and show that bluff-body type of combustor has ability and easement to control aerodynamically spray angle, shape and droplet trajectories. It is

  16. Nanoscale Phase Immiscibility in High-ZT Bulk Lead Telluride Thermoelectric Materials

    NASA Astrophysics Data System (ADS)

    Girard, Steven Neal

    Renewable energy initiatives have increased interest in thermoelectric materials as an option for inexpensive and environmentally friendly waste heat-to-power generation. Unfortunately, low efficiencies have limited their wide-scale utilization. This work describes the synthesis and characterization of bulk nanostructured thermoelectric materials wherein natural phase immiscibility is manipulated to selectively generate nanoscale inclusions of a second phase that improve their efficiency through reductions in lattice thermal conductivity. The PbTe-PbS system exhibits natural phase separation by nucleation and growth or spinodal decomposition phase transformations depending on composition and temperature treatment. Through rapid quenching, nearly ideal solid solution alloys of PbTe-PbS are observed by powder X-ray diffraction. However, characterization by solid-state NMR and IR reflectivity show that solid solutions are obtained for rapidly quenched samples within the nucleation and growth region of the phase diagram, but samples within the spinodal decomposition region exhibit very slight phase immiscibility. We report the temperatures of phase separation using high temperature powder X-ray diffraction. Microscopy reveals that phase separation in PbTe-PbS naturally produces nanoinclusions. A decrease in lattice thermal conductivity is observed as a result of the solid solution-to-nanostructured phase transformation in this materials system, increasing thermoelectric figure of merit. Sn addition to PbTe-PbS produces a pseudobinary system of PbTe-PbSnS 2. This materials system produces microscale lamellae that effectively reduce lattice thermal conductivity. Unfortunately, the PbSnS2 inclusions also scatter electrons, reducing electrical conductivity and producing only a minimal increase in thermoelectric figure of merit. We additionally investigate PbSnS2 as prepared through Bridgman crystal growth. PbTe-PbS doped with Na appears to increase the kinetic rate of

  17. Determination of local atomic arrangements in a bulk-immiscible surface alloy

    NASA Astrophysics Data System (ADS)

    Witkowski, Kristine Rose

    Surface alloys are two-dimensional phases confined to near-surface regions, and are known to form from atomic species that are immiscible in the bulk. In order to achieve a better understanding of this phenomenon, it is necessary to be able to accurately determine the bond lengths present within the surface alloy. The present work focuses on surface alloying in the bulk-immiscible Au-Ni system, which forms surface alloy phases that are amongst the most studied to date. First principles electronic density functional theory calculations were conducted for both "monomer" (single Au atom), and "dimer" (pair of Au atoms) surface alloying models for the Au-Ni(110) surface. Both of the models exhibited surface interlayer contractions and expansions similar to those reported for a Ni(110) surface. The resulting atomic positions corresponded to Au-Ni bond lengths of 2.61-2.80 A in the monomer model and 2.54-2.84 A in the dimer model. Surface extended x-ray absorption fine structure (SEXAFS) measurements were taken from Au-Co11Ni89(110) surface alloys. The software program FEFF8 was used in combination with the first principles calculated atomic positions for the surface alloy models to simulate the SEXAFS from each of the surface alloy models. Fits were conducted from these models resulting in the determination of Au-Ni bond lengths of 2.55-2.74 A with the monomer model, and 2.46-2.76 A with the dimer model. The present work features the first theoretical first principles study of all of the sub-monolayer structures of the Au-Ni(110) system. This work was also the first to employ DFT calculated atomic positions as initial models for simulating theoretical SEXAFS spectra to assist in the fitting of experimental measurements. In doing this, the theoretical calculations allowed for a much better starting point in the fits, while the results from the fits gave an indication to the strengths and weaknesses of the surface calculations, since they highlighted an apparent slight

  18. Comparative cost models of a liquid nitrogen vapor phase (LNVP) cold chain-distributed cryopreserved malaria vaccine vs. a conventional vaccine

    PubMed Central

    Garcia, Cristina Reyes; Manzi, Fatuma; Tediosi, Fabrizio; Hoffman, Stephen L.; James, Eric R.

    2013-01-01

    Typically, vaccines distributed through the Expanded Program on Immunization (EPI) use a 2–8 °C cold chain with 4–5 stops. The PfSPZ Vaccine comprises whole live-attenuated cryopreserved sporozoites stored in liquid nitrogen (LN2) vapor phase (LNVP) below −140 °C and would be distributed through a LNVP cold chain. The purpose of this study was to model LNVP cold chain distribution for the cryopreserved PfSPZ Vaccine in Tanzania, estimate the costs and compare these costs to those that would be incurred in distributing a ‘conventional’ malaria vaccine through the EPI. Capital and recurrent costs for storage, transportation, labor, energy usage and facilities were determined for the birth cohort in Tanzania over five years. Costs were calculated using WHO/UNESCO calculators. These were applied to a 2–8 °C distribution model with national, regional, district, and health facility levels, and for the cryopreserved vaccine using a ‘modified hub-and-spoke’ (MH-S) LNVP distribution system comprising a central national store, peripheral health facilities and an intermediate district-level transhipment stop. Estimated costs per fully immunized child (FIC) were $ 6.11 for the LNVP-distributed cryopreserved vaccine where the LN2 is generated, and $ 6.04 with purchased LN2 (assuming US $ 1.00/L). The FIC costs for distributing a conventional vaccine using the four level 2–8 °C cold chain were $ 6.10, and with a tariff distribution system as occurs in Tanzania the FIC cost was $ 5.53. The models, therefore, predicted little difference in 5-year distribution costs between the PfSPZ Vaccine distributed through a MH-S LNVP cold chain and a conventional vaccine distributed through the more traditional EPI system. A LNVP cold chain provides additional benefits through the use of durable dry shippers because no refrigerators, freezers or refrigerated trucks are required. Thus strain at the cold chain periphery, vaccine wastage from cold chain failures and the

  19. Microchannel liquid-flow focusing and cryo-polymerization preparation of supermacroporous cryogel beads for bioseparation.

    PubMed

    Yun, Junxian; Tu, Changming; Lin, Dong-Qiang; Xu, Linhong; Guo, Yantao; Shen, Shaochuan; Zhang, Songhong; Yao, Kejian; Guan, Yi-Xin; Yao, Shan-Jing

    2012-07-20

    Polymeric cryogels are sponge-like materials with supermacroporous structure, allowing them to be of interest as new chromatographic supports, cell scaffolds and drug carriers in biological and biomedical areas. The matrices of cryogels are always prepared in the form of monoliths by cryo-polymerization under frozen conditions. However, there are limited investigations on the production of cryogels in the form of adsorbent beads suitable for bioseparation. In this work, we provide a new approach by combining the microchannel liquid-flow focusing with cryo-polymerization for the preparation of polyacrylamide-based supermacroporous cryogel beads with a narrow particle size distribution. The present method was achieved by introducing the aqueous phase solution containing monomer, cross-linker and redox initiators, and the water-immiscible organic oil phase containing surfactant simultaneously into a microchannel with a cross-shaped junction, where the aqueous drops with uniform sizes were generated by the liquid shearing and the segmentation due to the steady flow focusing of the immiscible phase streams. These liquid drops were in situ suspended into the freezing bulk oil phase for cryo-polymerization and the cryogel matrix beads were obtained by thawing after the achievement of polymerization. By grafting the polymer chains containing sulfo binding groups onto these matrix beads, the cation-exchange cryogel beads for protein separation were produced. The results showed that at the aqueous phase velocities from 0.5 to 2.0 cm/s and the total velocities of the water-immiscible phase from 2.0 to 6.0 cm/s, the obtained cryogel beads by the present method have narrow size distributions with most of the bead diameters in the range from 800 to 1500 μm with supermacropores in sizes of about 3-50 μm. These beads also have high porosities with the averaged maximum porosity of 96.9% and the mean effective porosity of 86.2%, which are close to those of the polyacrylamide

  20. Syringe needle-based sampling coupled with liquid-phase extraction for determination of the three-dimensional distribution of l-ascorbic acid in apples.

    PubMed

    Tang, Sheng; Lee, Hian Kee

    2016-05-15

    A novel syringe needle-based sampling approach coupled with liquid-phase extraction (NBS-LPE) was developed and applied to the extraction of l-ascorbic acid (AsA) in apple. In NBS-LPE, only a small amount of apple flesh (ca. 10mg) was sampled directly using a syringe needle and placed in a glass insert for liquid extraction of AsA by 80 μL oxalic acid-acetic acid. The extract was then directly analyzed by liquid chromatography. This new procedure is simple, convenient, almost organic solvent free, and causes far less damage to the fruit. To demonstrate the applicability of NBS-LPE, AsA levels at different sampling points in a single apple were determined to reveal the spatial distribution of the analyte in a three-dimensional model. The results also showed that this method had good sensitivity (limit of detection of 0.0097 mg/100g; limit of quantification of 0.0323 mg/100g), acceptable reproducibility (relative standard deviation of 5.01% (n=6)), a wide linear range of between 0.05 and 50mg/100g, and good linearity (r(2)=0.9921). This interesting extraction technique and modeling approach can be used to measure and monitor a wide range of compounds in various parts of different soft-matrix fruits and vegetables, including single specimens. PMID:26776005

  1. Impact of micro-porous layer on liquid water distribution at the catalyst layer interface and cell performance in a polymer electrolyte membrane fuel cell

    NASA Astrophysics Data System (ADS)

    Tabe, Yutaka; Aoyama, Yusuke; Kadowaki, Kazumasa; Suzuki, Kengo; Chikahisa, Takemi

    2015-08-01

    In polymer electrolyte membrane fuel cells, a gas diffusion layer (GDL) with a micro-porous layer (MPL) gives better anti-flooding performance than GDLs without an MPL. To investigate the function and mechanism of the MPL to suppress water flooding, the liquid water distribution at the cathode catalyst layer (CL) surface are observed by a freezing method; in the method liquid water is immobilized in ice form by rapid freezing, followed by disassembling the cell for observations. The ice covered area is quantified by image processing and cells with and without an MPL are compared. The results show that the MPL suppresses water accumulation at the interface due to smaller pore size and finer contact with the CL, and this results in less water flooding. Investigation of ice formed after -10 °C cold start shutdowns and the temporary performance deterioration at ordinary temperatures also indicates a significant influence of the liquid water accumulating at the interface. The importance of the fine contact between CL and MPL, the relative absence of gaps, is demonstrated by a gas diffusion electrode (GDE) which is directly coated with catalyst ink on the surface of the MPL achieving finer contact of the layers.

  2. Facile and rapid DNA extraction and purification from food matrices using IFAST (immiscible filtration assisted by surface tension).

    PubMed

    Strotman, Lindsay N; Lin, Guangyun; Berry, Scott M; Johnson, Eric A; Beebe, David J

    2012-09-01

    Extraction and purification of DNA is a prerequisite to detection and analytical techniques. While DNA sample preparation methods have improved over the last few decades, current methods are still time consuming and labor intensive. Here we demonstrate a technology termed IFAST (Immiscible Filtration Assisted by Surface Tension), that relies on immiscible phase filtration to reduce the time and effort required to purify DNA. IFAST replaces the multiple wash and centrifugation steps required by traditional DNA sample preparation methods with a single step. To operate, DNA from lysed cells is bound to paramagnetic particles (PMPs) and drawn through an immiscible fluid phase barrier (i.e. oil) by an external handheld magnet. Purified DNA is then eluted from the PMPs. Here, detection of Clostridium botulinum type A (BoNT/A) in food matrices (milk, orange juice), a bioterrorism concern, was used as a model system to establish IFAST's utility in detection assays. Data validated that the DNA purified by IFAST was functional as a qPCR template to amplify the bont/A gene. The sensitivity limit of IFAST was comparable to the commercially available Invitrogen ChargeSwitch® method. Notably, pathogen detection via IFAST required only 8.5 μL of sample and was accomplished in five-fold less time. The simplicity, rapidity and portability of IFAST offer significant advantages when compared to existing DNA sample preparation methods. PMID:22814365

  3. Near-infrared stokes parameter method for determining two-dimensional cell thickness and twist angle distributions of liquid crystal color displays

    NASA Astrophysics Data System (ADS)

    Kawamura, Marenori; Sato, Susumu

    2002-12-01

    We propose a two-dimensional (2D) and hyperfine measurement method for precisely determining cell parameter distributions such as a cell thickness and twist angle in color liquid crystal (LC) displays. The 2D cell thickness and twist angle distributions can easily be determined by measuring Stokes parameters of all pixels for red, green and blue in LCD panel at a wavelength of near-infrared region, because the transmission light at the wavelength is not absorbed by each color filter. In addition, the spatial resolution can be improved by increasing the magnification of the objective lens in front of a high resolution CCD camera. These cell parameters of each pixel in the practical LCD panel are compared and discussed.

  4. Transport and Manipulation of Immiscible Fluids using Electro-Kinetic Techniques

    NASA Astrophysics Data System (ADS)

    Zhou, X.; Nolte, D. D.; Pyrak-Nolte, L. J.

    2015-12-01

    Applied electric fields modify the surface tension between a solid and a liquid and hence modify the wettability and contact angle on solid surfaces. Direct control over internal fluid distributions can be achieved by controlling contact angles that subsequently influence capillary pressures and drive motion of droplets across many millimeters. In this study, an Electro-Wetting on a Dielectric technique, EWOD, is used to: alter contact angles, merge and transport droplets on flat surfaces, and control the distribution of fluid phases. Liquid droplets were supported on flat glass substrates that had been evaporated with a 50 nm thick layer of silver (i.e., ground electrode) and then spin-coated with a ~5-10 μm thick layer of PDMS, a dielectric material. A platinum wire was inserted into 10 μL droplets of 1M KCl-H2O and connected to a 50 Hz AC voltage source. Measurements were made for a range of voltages (Vrms ~0-425V). CCD cameras were used to measure changes in areal extent, perimeter, and contact angles. For Vrms=0, the contact angle on PMDS was 118o. For the range of applied voltages, the contact angle of the droplets changed by over 60o. These experiments demonstrated that contact angle can be controlled over a wide range of values. Unsealed micro-models were used in experiments to merge and transport drops. In the merging experiments, three 50 nm thick electrodes were formed on the top plate separated by a gap of 0.69 mm, while the bottom plate contained a single large area silver electrode 50 nm thick. A 10 μL 1M KCl-H2O droplet was placed on the left electrode and another on the right electrode and merged when 424 V was applied to the middle electrode. The contact angle of the drops on the middle electrode decreased by 60 o relative to the portions of the drops on left and right electrodes. The resulting pressure difference translated and merged the two drops over a distance of ~1mm in ~13 seconds. These experiments demonstrate that EWOD techniques can be

  5. Suppression of phase coarsening in immiscible, co-continuous polymer blends under high temperature quiescent annealing.

    PubMed

    Liu, Xi-Qiang; Li, Ruo-Han; Bao, Rui-Ying; Jiang, Wen-Rou; Yang, Wei; Xie, Bang-Hu; Yang, Ming-Bo

    2014-05-28

    The properties of polymer blends greatly depend on the morphologies formed during processing, and the thermodynamic non-equilibrium nature of most polymer blends makes it important to maintain the morphology stability to ensure the performance stability of structural materials. Herein, the phase coarsening of co-continuous, immiscible polyamide 6 (PA6)-acrylonitrile-butadiene-styrene (ABS) blends in the melt state was studied and the effect of introduction of nano-silica particles on the stability of the phase morphology was examined. It was found that the PA6-ABS (50/50 w) blend maintained the co-continuous morphology but coarsened severely upon annealing at 230 °C. The coarsening process could be divided into two stages: a fast coarsening process at the initial stage of annealing and a second coarsening process with a relatively slow coarsening rate later. The reduction of the coarsening rate can be explained from the reduction of the global curvature of the interface. With the introduction of nano-silica, the composites also showed two stages of coarsening. However, the coarsening rate was significantly decreased and the phase morphology was stabilized. Rheological measurements indicated that a particle network structure was formed when the concentration of nano-silica particles was beyond 2 wt%. The particle network inhibited the movement of molecular chains and thus suppressed the coarsening process. PMID:24663286

  6. Non-traditional stable isotope behaviors in immiscible silica-melts in a mafic magma chamber

    PubMed Central

    Zhu, Dan; Bao, Huiming; Liu, Yun

    2015-01-01

    Non-traditional stable isotopes have increasingly been applied to studies of igneous processes including planetary differentiation. Equilibrium isotope fractionation of these elements in silicates is expected to be negligible at magmatic temperatures (δ57Fe difference often less than 0.2 per mil). However, an increasing number of data has revealed a puzzling observation, e.g., the δ57Fe for silicic magmas ranges from 0‰ up to 0.6‰, with the most positive δ57Fe almost exclusively found in A-type granitoids. Several interpretations have been proposed by different research groups, but these have so far failed to explain some aspects of the observations. Here we propose a dynamic, diffusion-induced isotope fractionation model that assumes Si-melts are growing and ascending immiscibly in a Fe-rich bulk magma chamber. Our model offers predictions on the behavior of non-traditional stable isotope such as Fe, Mg, Si, and Li that are consistent with observations from many A-type granitoids, especially those associated with layered intrusions. Diffusion-induced isotope fractionation may be more commonly preserved in magmatic rocks than was originally predicted. PMID:26620121

  7. Non-traditional stable isotope behaviors in immiscible silica-melts in a mafic magma chamber.

    PubMed

    Zhu, Dan; Bao, Huiming; Liu, Yun

    2015-01-01

    Non-traditional stable isotopes have increasingly been applied to studies of igneous processes including planetary differentiation. Equilibrium isotope fractionation of these elements in silicates is expected to be negligible at magmatic temperatures (δ(57)Fe difference often less than 0.2 per mil). However, an increasing number of data has revealed a puzzling observation, e.g., the δ(57)Fe for silicic magmas ranges from 0‰ up to 0.6‰, with the most positive δ(57)Fe almost exclusively found in A-type granitoids. Several interpretations have been proposed by different research groups, but these have so far failed to explain some aspects of the observations. Here we propose a dynamic, diffusion-induced isotope fractionation model that assumes Si-melts are growing and ascending immiscibly in a Fe-rich bulk magma chamber. Our model offers predictions on the behavior of non-traditional stable isotope such as Fe, Mg, Si, and Li that are consistent with observations from many A-type granitoids, especially those associated with layered intrusions. Diffusion-induced isotope fractionation may be more commonly preserved in magmatic rocks than was originally predicted. PMID:26620121

  8. Zener Pinning of Grain Boundaries and Structural Stability of Immiscible Alloys

    NASA Astrophysics Data System (ADS)

    Koju, R. K.; Darling, K. A.; Kecskes, L. J.; Mishin, Y.

    2016-04-01

    Immiscible Cu-Ta alloys produced by mechanical alloying are currently the subject of intensive research due to their mechanical strength combined with extraordinary structural stability at high temperatures. Previous experimental and simulation studies suggested that grain boundaries (GBs) in Cu-Ta alloys are stabilized by Ta nano-clusters coherent with the Cu matrix. To better understand the stabilization effect of Ta, we performed atomistic computer simulations of GB-cluster interactions in Cu-Ta alloys with various compositions and GB velocities. The study focuses on a single plane GB driven by an applied shear stress due to the shear-coupling effect. The results of the simulations are in close quantitative agreement with the Zener model of GB pinning. This agreement and the large magnitude of the unpinning stress confirm that the structural stability of these alloys is due to the drastically decreased GB mobility rather than a reduction in GB energy. For comparison, we simulated GB motion in a random solid solution. While the latter also reduces the GB mobility, the effect is not as strong as in the presence of Ta clusters. GB motion in the random solution itself induces precipitation of Ta clusters due to short-circuit diffusion of Ta in GBs, suggesting a possible mechanism of cluster formation inside the grains.

  9. Non-traditional stable isotope behaviors in immiscible silica-melts in a mafic magma chamber

    NASA Astrophysics Data System (ADS)

    Zhu, Dan; Bao, Huiming; Liu, Yun

    2015-12-01

    Non-traditional stable isotopes have increasingly been applied to studies of igneous processes including planetary differentiation. Equilibrium isotope fractionation of these elements in silicates is expected to be negligible at magmatic temperatures (δ57Fe difference often less than 0.2 per mil). However, an increasing number of data has revealed a puzzling observation, e.g., the δ57Fe for silicic magmas ranges from 0‰ up to 0.6‰, with the most positive δ57Fe almost exclusively found in A-type granitoids. Several interpretations have been proposed by different research groups, but these have so far failed to explain some aspects of the observations. Here we propose a dynamic, diffusion-induced isotope fractionation model that assumes Si-melts are growing and ascending immiscibly in a Fe-rich bulk magma chamber. Our model offers predictions on the behavior of non-traditional stable isotope such as Fe, Mg, Si, and Li that are consistent with observations from many A-type granitoids, especially those associated with layered intrusions. Diffusion-induced isotope fractionation may be more commonly preserved in magmatic rocks than was originally predicted.

  10. Flow of immiscible ferrofluids in a planar gap in a rotating magnetic field

    SciTech Connect

    Sule, Bhumika; Torres-Díaz, Isaac; Rinaldi, Carlos

    2015-07-15

    Analytical solutions are obtained for the steady, fully developed flow of two layers of immiscible ferrofluids of different thicknesses between two parallel plates. Interfacial linear and internal angular momentum balance relations are derived for the case when there is a ferrofluid-ferrofluid interface to obtain the translational and spin velocity profiles in the gap. As expected for the limit of low applied field amplitude, the magnitude of the translational velocity is directly proportional to the frequency of the applied magnetic field and to the square of the magnetic field amplitude. Expressions for the velocity profiles are obtained for the zero spin viscosity and non-zero spin viscosity cases and the effect of applied pressure gradient on the flows is studied. The spin velocity in both ferrofluid phases is in the direction of the rotating magnetic field, except for cases of extreme applied pressure gradients for which the fluid vorticity opposes the spin. We find that for the case of non-zero spin viscosity, flow reversals are predicted using representative ferrofluid property values and field conditions. The unique predictions of the solution with non-zero spin viscosity could be used to experimentally test the existence of couple stresses in ferrofluids and the validity of previously reported values of the so-called spin viscosity.

  11. HIV Viral RNA Extraction in Wax Immiscible Filtration Assisted by Surface Tension (IFAST) Devices

    PubMed Central

    Berry, Scott M.; LaVanway, Alex J.; Pezzi, Hannah M.; Guckenberger, David J.; Anderson, Meghan A.; Loeb, Jennifer M.; Beebe, David J.

    2015-01-01

    The monitoring of viral load is critical for proper management of antiretroviral therapy for HIV-positive patients. Unfortunately, in the developing world, significant economic and geographical barriers exist, limiting access to this test. The complexity of current viral load assays makes them expensive and their access limited to advanced facilities. We attempted to address these limitations by replacing conventional RNA extraction, one of the essential processes in viral load quantitation, with a simplified technique known as immiscible filtration assisted by surface tension (IFAST). Furthermore, these devices were produced via the embossing of wax, enabling local populations to produce and dispose of their own devices with minimal training or infrastructure, potentially reducing the total assay cost. In addition, IFAST can be used to reduce cold chain dependence during transportation. Viral RNA extracted from raw samples stored at 37°C for 1 week exhibited nearly complete degradation. However, IFAST-purified RNA could be stored at 37°C for 1 week without significant loss. These data suggest that RNA isolated at the point of care (eg, in a rural clinic) via IFAST could be shipped to a central laboratory for quantitative RT-PCR without a cold chain. Using this technology, we have demonstrated accurate and repeatable measurements of viral load on samples with as low as 50 copies per milliliter of sample. PMID:24613822

  12. Exchange flow of two immiscible Newtonian fluids in a vertical tube

    NASA Astrophysics Data System (ADS)

    Varges, Priscilla; Nascentes, Fernanda; Fonseca, Bruno; de Souza Mendes, Paulo Roberto; Naccache, Monica

    2015-11-01

    Plug cementing is an essential operation performed under a variety of well conditions. The cement plugs are rarely placed at the intended depth because the cement slurry usually is heavier than the well fluid. Failures are due primarily to migration of the denser fluid downward through the drilling fluid at the top of which it is discharged. The aim of the research is to better understand the process of plugging operation in vertical wells. To this end, we performed an experimental and theoretical study of the buoyancy-driven flow of two immiscible Newtonian fluids in a vertical tube such that the heavier and more viscous fluid is placed on top. Since both fluids are Newtonian, the situation is always unstable, i.e. the fluid on top will always flow downward and displace the bottom fluid upwards, so that the relative positioning tends to invert. The influence of the governing parameters on the speed of inversion was investigated. Flow visualization was performed with a digital camera, and inversion velocities were obtained through image analysis. Preliminary results show that inversion speed decreases as the tube diameter is increased, increases as the viscosity ratio is increased, and also increases as the density ratio is increased.

  13. In situ study of heavy ion irradiation response of immiscible Cu/Fe multilayers

    NASA Astrophysics Data System (ADS)

    Chen, Y.; Li, N.; Bufford, D. C.; Li, J.; Hattar, K.; Wang, H.; Zhang, X.

    2016-07-01

    Recent studies show that immiscible metallic multilayers with incoherent interfaces can effectively reduce defect density in ion irradiated metals by providing active defect sinks that capture and annihilate radiation induced defect clusters. Although it is anticipated that defect density within the layers should vary as a function of distance to the layer interface, there is, to date, little in situ TEM evidence to validate this hypothesis. In this study monolithic Cu films and Cu/Fe multilayers with individual layer thickness, h, of 100 and 5 nm were subjected to in situ Cu ion irradiation at room temperature to nominally 1 displacement-per-atom inside a transmission electron microscope. Rapid formation and propagation of defect clusters were observed in monolithic Cu, whereas fewer defects with smaller dimensions were generated in Cu/Fe multilayers with smaller h. Furthermore in situ video shows that the cumulative defect density in Cu/Fe 100 nm multilayers indeed varies, as a function of distance to the layer interfaces, supporting a long postulated hypothesis.

  14. An overview of instability and fingering during immiscible fluid flow in porous and fractured media

    SciTech Connect

    Chen, G.; Neuman, S.P.; Taniguchi, M.

    1995-04-01

    Wetting front instability is an important phenomenon affecting fluid flow and contaminant transport in unsaturated soils and rocks. It causes the development of fingers which travel faster than would a uniform front and thus bypass much of the medium. Water saturation and solute concentration in such fingers tend to be higher than in the surrounding medium. During infiltration, fingering may cause unexpectedly rapid arrival of water and solute at the water-table. This notwithstanding, most models of subsurface flow and transport ignore instability and fingering. In this report, we survey the literature to assess the extent to which this may or may not be justified. Our overview covers experiments, theoretical studies, and computer simulations of instability and fingering during immiscible two-phase flow and transport, with emphasis on infiltration into soils and fractured rocks. Our description of instability in an ideal fracture (Hele-Shaw cell) includes an extension of existing theory to fractures and interfaces having arbitrary orientations in space. Our discussion of instability in porous media includes a slight but important correction of existing theory for the case of an inclined interface. We conclude by outlining some potential directions for future research. Among these, we single out the effect of soil and rock heterogeneities on instability and preferential flow as meriting special attention in the context of nuclear waste storage in unsaturated media.

  15. Flow of immiscible ferrofluids in a planar gap in a rotating magnetic field

    NASA Astrophysics Data System (ADS)

    Sule, Bhumika; Torres-Díaz, Isaac; Rinaldi, Carlos

    2015-07-01

    Analytical solutions are obtained for the steady, fully developed flow of two layers of immiscible ferrofluids of different thicknesses between two parallel plates. Interfacial linear and internal angular momentum balance relations are derived for the case when there is a ferrofluid-ferrofluid interface to obtain the translational and spin velocity profiles in the gap. As expected for the limit of low applied field amplitude, the magnitude of the translational velocity is directly proportional to the frequency of the applied magnetic field and to the square of the magnetic field amplitude. Expressions for the velocity profiles are obtained for the zero spin viscosity and non-zero spin viscosity cases and the effect of applied pressure gradient on the flows is studied. The spin velocity in both ferrofluid phases is in the direction of the rotating magnetic field, except for cases of extreme applied pressure gradients for which the fluid vorticity opposes the spin. We find that for the case of non-zero spin viscosity, flow reversals are predicted using representative ferrofluid property values and field conditions. The unique predictions of the solution with non-zero spin viscosity could be used to experimentally test the existence of couple stresses in ferrofluids and the validity of previously reported values of the so-called spin viscosity.

  16. Indications of fluid immiscibility in glass from West Clearwater Lake impact crater, Quebec, Canada

    NASA Technical Reports Server (NTRS)

    Dence, M. R.; Von Engelhardt, W.; Plant, A. G.; Walter, L. S.

    1974-01-01

    Glass from the West Clearwater Lake hypervelocity impact crater contains numerous spheroids, 10 to 500 microns across, which appear to have formed at high temperatures as fluids immiscible in the enclosing melt. The spheroids are distinguished from small, normal, largely void gas vesicles, which are also present, by being completely filled in all cases; by having fillings which vary in composition from spheroid to spheroid, even between spheroids in close association; and by indications that the present fillings are representative of the contents present before the matrix melt chilled. Most of the spheroids are classified petrographically into three types. The preservation of spheroids in the West Clearwater Lake glass is attributed mainly to the position of the glass masses within the breccias lining the crater floor. It is considered that the glass in this location did not achieve free flight but, as part of a large mass, cooled relatively slowly through the high temperature regime in which the spheroids were generated, and then, when detached, chilled rapidly to preserve a record of this transient stage in their history.

  17. Unconditionally convergent nonlinear solver for immiscible two-phase flow dominated by buoyancy and capillary forces

    NASA Astrophysics Data System (ADS)

    Tchelepi, H. A.; Wang, X.

    2011-12-01

    We describe a Newton-based nonlinear solver for immiscible two-phase Darcy flow and transport in the presence of significant viscous, buoyancy, and capillary forces. The evolution of CO2 plumes in heterogeneous saline aquifers, especially during the post-injection period, is an important example of this class of problem. The total flux (fractional flow) function is split into two parts: one part accounts for the viscous and buoyancy forces, and the other part accounts for capillarity. These flux functions, which are strongly nonlinear functions of saturation, are divided into trust regions. The delineation of the regions is dictated by the inflection, sonic, and end points present in the two flux functions. Within each trust region, the standard Newton iterative scheme is guaranteed to converge. For problems where the dynamics are dominated by buoyancy and capillary forces, the proposed scheme allows for taking much larger time steps than existing Newton based solvers. The nonlinear solver is demonstrated using challenging CO2-brine problems in heterogeneous domains with emphasis on the post-injection period.

  18. Zener Pinning of Grain Boundaries and Structural Stability of Immiscible Alloys

    NASA Astrophysics Data System (ADS)

    Koju, R. K.; Darling, K. A.; Kecskes, L. J.; Mishin, Y.

    2016-06-01

    Immiscible Cu-Ta alloys produced by mechanical alloying are currently the subject of intensive research due to their mechanical strength combined with extraordinary structural stability at high temperatures. Previous experimental and simulation studies suggested that grain boundaries (GBs) in Cu-Ta alloys are stabilized by Ta nano-clusters coherent with the Cu matrix. To better understand the stabilization effect of Ta, we performed atomistic computer simulations of GB-cluster interactions in Cu-Ta alloys with various compositions and GB velocities. The study focuses on a single plane GB driven by an applied shear stress due to the shear-coupling effect. The results of the simulations are in close quantitative agreement with the Zener model of GB pinning. This agreement and the large magnitude of the unpinning stress confirm that the structural stability of these alloys is due to the drastically decreased GB mobility rather than a reduction in GB energy. For comparison, we simulated GB motion in a random solid solution. While the latter also reduces the GB mobility, the effect is not as strong as in the presence of Ta clusters. GB motion in the random solution itself induces precipitation of Ta clusters due to short-circuit diffusion of Ta in GBs, suggesting a possible mechanism of cluster formation inside the grains.

  19. Investigation of the local structure of mixtures of an ionic liquid with polar molecular species through molecular dynamics: cluster formation and angular distributions.

    PubMed

    Carrete, Jesús; Méndez-Morales, Trinidad; Cabeza, Óscar; Lynden-Bell, Ruth M; Gallego, Luis J; Varela, Luis M

    2012-05-24

    In this work, we used molecular dynamics simulations to analyze in detail the spatial distributions of the different constituents in mixtures of 1-butyl-3-methylimidazolium tetrafluoroborate with three polar molecular species: water and two alcohols of different chain lengths (methanol and ethanol). In particular, we report results regarding the influence of the chosen species and its concentration on the formation of ionic and molecular clusters over the whole miscibility range, as well as on the angular distribution of polar molecules around the anion and the cation in these systems. Both analyses showed that addition of a molecular species breaks down the polar network of the pure ionic liquid in clusters whose mean size decreases progressively as more molecules are added. At very high concentrations of the molecular species, the ions are found to be isolated in mixtures with water and methanol, but they tend to form pairs in ethanol. In mixtures with water we identified large clusters that form a water network at very high water concentrations, while at low water concentrations polar molecules tend to form smaller aggregates. In contrast, in mixtures with alkanols there is no evidence of the formation of large alcohol clusters at any concentration. Spatial order in alcohol was also studied by means of the Kirkwood G factor, reaching the conclusion that the angular correlations which appear in pure alcohols due to dipole interactions are destroyed by the ionic liquid, even when present only in tiny amounts. PMID:22587330

  20. Hydrogenation of coal liquid utilizing a metal carbonyl catalyst

    DOEpatents

    Feder, Harold M.; Rathke, Jerome W.

    1979-01-01

    Coal liquid having a dissolved transition metal, catalyst as a carbonyl complex such as Co.sub.2 (CO.sub.8) is hydrogenated with hydrogen gas or a hydrogen donor. A dissociating solvent contacts the coal liquid during hydrogenation to form an immiscible liquid mixture at a high carbon monoxide pressure. The dissociating solvent, e.g. ethylene glycol, is of moderate coordinating ability, while sufficiently polar to solvate the transition metal as a complex cation along with a transition metal, carbonyl anion in solution at a decreased carbon monoxide pressure. The carbon monoxide pressure is reduced and the liquids are separated to recover the hydrogenated coal liquid as product. The dissociating solvent with the catalyst in ionized form is recycled to the hydrogenation step at the elevated carbon monoxide pressure for reforming the catalyst complex within fresh coal liquid.

  1. Surface charge dynamics and OH and H number density distributions in near-surface nanosecond pulse discharges at a liquid / vapor interface

    NASA Astrophysics Data System (ADS)

    Winters, Caroline; Petrishchev, Vitaly; Yin, Zhiyao; Lempert, Walter R.; Adamovich, Igor V.

    2015-10-01

    The present work provides insight into surface charge dynamics and kinetics of radical species reactions in nanosecond pulse discharges sustained at a liquid-vapor interface, above a distilled water surface. The near-surface plasma is sustained using two different discharge configurations, a surface ionization wave discharge between two exposed metal electrodes and a double dielectric barrier discharge. At low discharge pulse repetition rates (~100 Hz), residual surface charge deposition after the discharge pulse is a minor effect. At high pulse repetition rates (~10 kHz), significant negative surface charge accumulation over multiple discharge pulses is detected, both during alternating polarity and negative polarity pulse trains. Laser induced fluorescence (LIF) and two-photon absorption LIF (TALIF) line imaging are used for in situ measurements of spatial distributions of absolute OH and H atom number densities in near-surface, repetitive nanosecond pulse discharge plasmas. Both in a surface ionization wave discharge and in a double dielectric barrier discharge, peak measured H atom number density, [H] is much higher compared to peak OH number density, due to more rapid OH decay in the afterglow between the discharge pulses. Higher OH number density was measured near the regions with higher plasma emission intensity. Both OH and especially H atoms diffuse out of the surface ionization wave plasma volume, up to several mm from the liquid surface. Kinetic modeling calculations using a quasi-zero-dimensional H2O vapor / Ar plasma model are in qualitative agreement with the experimental data. The results demonstrate the experimental capability of in situ radical species number density distribution measurements in liquid-vapor interface plasmas, in a simple canonical geometry that lends itself to the validation of kinetic models.

  2. Analytical and experimental investigation of liquid double drop dynamics: Preliminary design for space shuttle experiments

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The preliminary grant assessed the use of laboratory experiments for simulating low g liquid drop experiments in the space shuttle environment. Investigations were begun of appropriate immiscible liquid systems, design of experimental apparatus and analyses. The current grant continued these topics, completed construction and preliminary testing of the experimental apparatus, and performed experiments on single and compound liquid drops. A continuing assessment of laboratory capabilities, and the interests of project personnel and available collaborators, led to, after consultations with NASA personnel, a research emphasis specializing on compound drops consisting of hollow plastic or elastic spheroids filled with liquids.

  3. Mineralogy and geochemistry of Fe-Ti oxide and apatite (nelsonite) deposits and evaluation of the liquid immiscibility hypothesis.

    USGS Publications Warehouse

    Kolker, A.

    1982-01-01

    The modal mineralogy for 32 Fe-Ti oxides and apatites supports the 2:1 oxide:apatite ratio for these samples from New York, Quebec, Norway and Sweden. Accessory minerals include: biotite, clinoamphibole, spinel, zircon and sulphides, oxygen fugacities range from 10-11 to 10-20, and T 600o to 1000oC. - K.A.R.

  4. Geometric and energetic considerations of surface fluctuations during ion transfer across the water-immiscible organic liquid interface.

    PubMed

    Karnes, John J; Benjamin, Ilan

    2016-07-01

    Molecular dynamics simulations and umbrella sampling free energy calculations are used to examine the thermodynamics, energetics, and structural fluctuations that accompany the transfer of a small hydrophilic ion (Cl(-)) across the water/nitrobenzene interface. By examining several constrained interface structures, we isolate the energetic costs of interfacial deformation and co-transfer of hydration waters during the ion transfer. The process is monitored using both energy-based solvation coordinates and a geometric coordinate recently introduced by Morita and co-workers to describe surface fluctuations. Our simulations show that these coordinates provide a complimentary description of the water surface fluctuations during the transfer and are necessary for elucidating the mechanism of the ion transfer. PMID:27394115

  5. Geometric and energetic considerations of surface fluctuations during ion transfer across the water-immiscible organic liquid interface

    NASA Astrophysics Data System (ADS)

    Karnes, John J.; Benjamin, Ilan

    2016-07-01

    Molecular dynamics simulations and umbrella sampling free energy calculations are used to examine the thermodynamics, energetics, and structural fluctuations that accompany the transfer of a small hydrophilic ion (Cl-) across the water/nitrobenzene interface. By examining several constrained interface structures, we isolate the energetic costs of interfacial deformation and co-transfer of hydration waters during the ion transfer. The process is monitored using both energy-based solvation coordinates and a geometric coordinate recently introduced by Morita and co-workers to describe surface fluctuations. Our simulations show that these coordinates provide a complimentary description of the water surface fluctuations during the transfer and are necessary for elucidating the mechanism of the ion transfer.

  6. Heat Transfer from Condensate Droplets Falling through an Immiscible Layer of Tributyl Phosphate

    SciTech Connect

    Laurinat, James E.

    2005-08-22

    As part of a safety analysis of reactions in two-layer mixtures of nitric acid and tributyl phosphate (TBP), an experiment was conducted to study how steam condensate mixes with the TBP layer when steam passes over a TBP-nitric acid mixture. The experiments showed that the condensate does not form a separate layer on top of the TBP but instead percolates as droplets through the TBP layer. The temperature at the top surface of the TBP layer undergoes a step change increase when the initial condensate droplets reach the surface. Temperatures at the surface and within the TBP and aqueous layers subsequently approach a steady state distribution governed by laminar convection and radiation heat transfer from the vapor space above the two-layer mixture. The rate of temperature increase and the steady state temperature gradient are determined by a characteristic propagation velocity and a streamwise dispersion coefficient for heat transfer. The propagation velocity is the geometric mean of the thermal convection velocities for the organic and aqueous phases, and the dispersion coefficient equals 0.494 times the product of the superficial condensate droplet velocity and the diameter of the test vessel. The value of the dispersion coefficient agrees with the Joshi (1980) correlation for liquid phase backmixing in bubble columns. Transient perturbations occur in the TBP layer temperatures. A Fourier analysis shows that the dominant frequency of these perturbations equals the natural frequency given by the transient heat transfer solution.

  7. Mass spectrometry imaging of levofloxacin distribution in TB-infected pulmonary lesions by MALDI-MSI and continuous liquid microjunction surface sampling

    PubMed Central

    Prideaux, Brendan; ElNaggar, Mariam S.; Zimmerman, Matthew; Wiseman, Justin M.; Li, Xiaohua; Dartois, Véronique

    2015-01-01

    A multi-modal mass spectrometry imaging (MSI) and profiling approach has been applied to assess the partitioning of the anti-TB fluoroquinolone levofloxacin into pulmonary lesions. Matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI) and a commercial liquid microjunction surface sampling technology (LMJ-SSP), or flowprobe, have been used to both spatially profile and image drug distributions in lung tissue sections from TB-infected rabbits following oral administration of a single human-equivalent dose. Levofloxacin levels were highest at 6 h post-dose in normal lung, cellular granuloma, and necrotic caseum compartments. The drug accumulated in the cellular granuloma regions with lower amounts partitioning into central caseous compartments. Flowprobe imaging at 630 μm (limited by the probe tip diameter) enabled visualization of drug distribution into lesion compartments, including limited differentiation of relative drug abundance in cellular versus caseous regions of the lesions. MALDI-MSI analysis at 75 μm provided more detailed drug distribution, which clearly accumulated in the cellular region immediately surrounding the central caseum core. Imaging and profiling data acquired by flowprobe and MALDI-MSI were validated by quantitative LC/MS/MS analysis of lung and granuloma homogenates taken from the same animals. The results of the investigation show flowprobe imaging and sampling as a rapid and sensitive alternative to MALDI-MSI for profiling drug distributions into tissues when spatial resolution of data below the threshold of the probe diameter is not required. PMID:26185484

  8. Dynamics of capillary-driven liquid-liquid displacement in open microchannels.

    PubMed

    Yang, D; Krasowska, M; Priest, C; Ralston, J

    2014-11-28

    The dynamics of the spontaneous spreading of a liquid droplet along an open hydrophilic microchannel filled with another immiscible liquid is primarily determined by the competition between the capillary driving force and the viscous drag. While the former force depends on the channel cross-section and dimensions, interfacial tension between two liquids and the contact angle formed between the channel's wall and the two liquids, the latter arises from the motion of fluid molecules in the two bulk liquids. This paper focuses on the influence of the outer (displaced) phase viscosity. In general, as the viscosity of the displaced phase increases relative to the viscosity of the displacing phase, the velocity of the liquid-liquid meniscus decreases. The experiments were interpreted by extending a previously established correlation for liquid-vapour systems (J. Phys. Chem. C, 2011, 115(38), 18761-18769) in open microchannels of the same geometry. The relationship between the liquid-liquid flow dynamics and the properties of the liquids (e.g. viscosities) is still unclear. Nonetheless, by taking a self-consistent empirical approach to estimate the influence of the viscosities on the flow kinetics for a given system, it is possible to obtain a reasonable theoretical description for the experimental system over a specific range of viscosity ratios. PMID:25308905

  9. High resolution retrieval of liquid water vertical distributions using collocated Ka-band and W-band cloud radars

    NASA Astrophysics Data System (ADS)

    Huang, Dong; Johnson, Karen; Liu, Yangang; Wiscombe, Warren

    2009-12-01

    The retrieval of cloud water content using dual-frequency radar attenuation is very sensitive to error in radar reflectivity. Either a long radar dwell time or an average over many range gates is needed to reduce random noise in radar data and thus to obtain accurate retrievals - but at the cost of poorer temporal and spatial resolution. In this letter we have shown that, by using advanced mathematical inversion techniques like total variation regularization, vertically resolved liquid water content can be retrieved at an accuracy of about 0.15 gm-3 at 40 m resolution. This is demonstrated using the co-located Ka-band and W-band cloud radars operated by the Atmospheric Radiation Measurement program. The liquid water path calculated from the radars agrees closely with that from a microwave radiometer, with a mean difference of 70 gm-2. Comparison with lidar observations reveals that the dual-frequency retrieval also reasonably captures the cloud base height of drizzling clouds - something that is very difficult to determine from radar reflectivity alone.

  10. Late-magmatic immiscibility during batholith formation: assessment of B isotopes and trace elements in tourmaline from the Land's End granite, SW England

    NASA Astrophysics Data System (ADS)

    Drivenes, Kristian; Larsen, Rune B.; Müller, Axel; Sørensen, Bjørn E.; Wiedenbeck, Michael; Raanes, Morten P.

    2015-06-01

    Quartz-tourmaline orbicules are unevenly distributed in the roof segment of the Land's End granite, SW England. This study shows that the orbicules formed from an immiscible hydrous borosilicate melt produced during the late stages of crystallization, and differentiates tourmaline formed by dominantly magmatic and dominantly hydrothermal processes. Trace elements and boron isotope fractionation can be tracked in tourmaline, and create a timeline for crystallization. Tourmaline from the granite matrix has higher V, Cr and Mg content and is isotopically heavier than the later crystallizing inner orbicule tourmaline. Overgrowths of blue tourmaline, occurring together with quartz showing hydrothermal cathodoluminescence textures, crystallized from an aqueous fluid during the very last crystallization, and are significantly higher in Sr and Sn, and isotopically heavier. Tourmaline associated with Sn mineralization is also high in Sr and Sn, but has boron isotopic compositions close to that of the magmatic tourmaline, and is not formed by the same fluids responsible for the blue overgrowths. The ore-forming fluids precipitating tourmaline and cassiterite are likely derived from the same magma source as the granite, but exsolved deeper in the magma chamber, and at a later stage than orbicule formation. Tourmaline from massive quartz-tourmaline rocks is concentrically zoned, with major and trace element compositions indicating crystallization from a similar melt as for the orbicules, but shows a more evolved signature.

  11. Measurements of gas hydrate formation probability distributions on a quasi-free water droplet

    NASA Astrophysics Data System (ADS)

    Maeda, Nobuo

    2014-06-01

    A High Pressure Automated Lag Time Apparatus (HP-ALTA) can measure gas hydrate formation probability distributions from water in a glass sample cell. In an HP-ALTA gas hydrate formation originates near the edges of the sample cell and gas hydrate films subsequently grow across the water-guest gas interface. It would ideally be desirable to be able to measure gas hydrate formation probability distributions of a single water droplet or mist that is freely levitating in a guest gas, but this is technically challenging. The next best option is to let a water droplet sit on top of a denser, immiscible, inert, and wall-wetting hydrophobic liquid to avoid contact of a water droplet with the solid walls. Here we report the development of a second generation HP-ALTA which can measure gas hydrate formation probability distributions of a water droplet which sits on a perfluorocarbon oil in a container that is coated with 1H,1H,2H,2H-Perfluorodecyltriethoxysilane. It was found that the gas hydrate formation probability distributions of such a quasi-free water droplet were significantly lower than those of water in a glass sample cell.

  12. Measurements of gas hydrate formation probability distributions on a quasi-free water droplet.

    PubMed

    Maeda, Nobuo

    2014-06-01

    A High Pressure Automated Lag Time Apparatus (HP-ALTA) can measure gas hydrate formation probability distributions from water in a glass sample cell. In an HP-ALTA gas hydrate formation originates near the edges of the sample cell and gas hydrate films subsequently grow across the water-guest gas interface. It would ideally be desirable to be able to measure gas hydrate formation probability distributions of a single water droplet or mist that is freely levitating in a guest gas, but this is technically challenging. The next best option is to let a water droplet sit on top of a denser, immiscible, inert, and wall-wetting hydrophobic liquid to avoid contact of a water droplet with the solid walls. Here we report the development of a second generation HP-ALTA which can measure gas hydrate formation probability distributions of a water droplet which sits on a perfluorocarbon oil in a container that is coated with 1H,1H,2H,2H-Perfluorodecyltriethoxysilane. It was found that the gas hydrate formation probability distributions of such a quasi-free water droplet were significantly lower than those of water in a glass sample cell. PMID:24985860

  13. Discovering Mercury Protein Modifications in Whole Proteomes Using Natural Isotope Distributions Observed in Liquid Chromatography-Tandem Mass Spectrometry

    SciTech Connect

    Polacco, Benjamin J.; Purvine, Samuel O.; Zink, Erika M.; LaVoie, Stephen P.; Lipton, Mary S.; Summers, Anne O.; Miller, Susan M.

    2011-08-01

    The identification of peptides that result from post-translational modifications is critical for understanding normal pathways of cellular regulation as well as identifying damage from, or exposures to xenobiotics, i.e. the exposome. However, because of their low abundance in proteomes, effective detection of modified peptides by mass spectrometry (MS) typically requires enrichment to eliminate false identifications. We present a new method for confidently identifying peptides with mercury (Hg)-containing adducts that is based on the influence of mercury’s seven stable isotopes on peptide isotope distributions detected by high-resolution MS. Using a pure protein and E. coli cultures exposed to phenyl mercuric acetate, we show the pattern of peak heights in isotope distributions from primary MS single scans efficiently identified Hg adducts in data from chromatographic separation coupled with tandem mass spectrometry with sensitivity and specificity greater than 90%. Isotope distributions are independent of peptide identifications based on peptide fragmentation (e.g. by SEQUEST), so both methods can be combined to eliminate false positives. Summing peptide isotope distributions across multiple scans improved specificity to 99.4% and sensitivity above 95%, affording identification of an unexpected Hg modification. We also illustrate the theoretical applicability of the method for detection of several less common elements including the essential element, selenium, as selenocysteine in peptides.

  14. Immiscible Fe- and Si-rich silicate melts in plagioclase from the Baima mafic intrusion (SW China): Implications for the origin of bi-modal igneous suites in large igneous provinces

    NASA Astrophysics Data System (ADS)

    Liu, Ping-Ping; Zhou, Mei-Fu; Ren, Zhongyuan; Wang, Christina Yan; Wang, Kun

    2016-09-01

    The Emeishan large igneous province (ELIP) in SW China is characterized by voluminous high-Ti and low-Ti basalts and spatially associated Fe-Ti oxide-bearing mafic-ultramafic and syenitic/granitic intrusions. The Baima layered mafic intrusion in the central part of the ELIP is surrounded by syenitic and granitic rocks and contains a Lower Zone of interlayered Fe-Ti oxide ores, troctolites and clinopyroxenites and an Upper Zone of isotropic olivine gabbros and gabbros (UZa) and apatite gabbros and Fe-Ti-P oxide ores (UZb). Polycrystalline mineral inclusions, for the first time, were observed in primocryst plagioclase from the basal part of the UZa through to the top of the UZb and consist mostly of clinopyroxene, plagioclase, magnetite, ilmenite and apatite with minor orthopyroxene, sulfide and hornblende. These minerals are commonly anhedral and form irregular shapes. Daughter plagioclase usually crystallizes on the walls of host primocryst plagioclase and has An contents typically 3-6 An% lower than the host plagioclase. Daughter clinopyroxene has similar Mg# but lower TiO2 and Al2O3 contents than primocryst clinopyroxene. These polycrystalline mineral inclusions are considered to crystallize from melts contemporaneous with host plagioclase. The compositional differences between daughter and primocryst minerals can be attributed to equilibrium crystallization in a closed system of the trapped melt inclusions in contrast to fractional crystallization and possible magma replenishment in an open system typical for primo-cumulates of large layered intrusions. Heated and homogenized melt inclusions have variable SiO2 (33-52 wt%), CaO (7-20 wt%), TiO2 (0.1-12 wt%), FeOt (5-20 wt%), P2O5 (0.2-10 wt%) and K2O (0-2.2 wt%). The large ranges of melt compositions are interpreted to result from heterogeneous trapping of different proportions of immiscible Si-rich and Fe-Ti-rich silicate liquids, together with entrapment of various microphenocrysts. The separation of micrometer

  15. Detaching droplets in immiscible fluids from a solid substrate with the help of electrowetting.

    PubMed

    Hong, Jiwoo; Lee, Sang Joon

    2015-02-01

    The detachment (or removal) of droplets from a solid surface is an indispensable process in numerous practical applications which utilize digital microfluidics, including cell-based assay, chip cooling, and particle sampling. When a droplet that is fully stretched by impacting or electrowetting is released, the conversion of stored surface energy to kinetic energy can lead to the departure of the droplet from a solid surface. Here we firstly detach sessile droplets in immiscible fluids from a hydrophobic surface by electrowetting. The physical conditions for droplet detachment depend on droplet volume, viscosity of ambient fluid, and applied voltage. Their critical conditions are determined by exploring the retracting dynamics for a wide range of driving voltages and physical properties of fluids. The relationships between physical parameters and dynamic characteristics of retracting and jumping droplets, such as contact time and jumping height, are also established. The threshold voltage for droplet detachment in oil with high viscosity is largely reduced (~70%) by electrowetting actuations with a square pulse. To examine the applicability of three-dimensional digital microfluidic (3D-DMF) platforms to biological applications such as cell culture and cell-based assays, we demonstrate the detachment of droplets containing a mixture of human umbilical vein endothelial cells (HUVECs) and collagen (concentration of 4 × 10(4) cells mL(-1)) in silicone oil with a viscosity of 0.65 cSt. Furthermore, to complement the technical limitations due to the use of a needle electrode and to demonstrate the applicability of the 3D-DMF platform with patterned electrodes to chemical analysis and synthesis, we examine the transport, merging, mixing, and detachment of droplets with different pH values on the platform. Finally, by using DC and AC electrowetting actuations, we demonstrate the detachment of oil droplets with a very low contact angle (<~13°) in water on a hydrophobic

  16. Modeling of Immiscible, Two-Phase Flows in a Natural Rock Fracture

    SciTech Connect

    Crandall, Dustin; Ahmadi, Goodarz; Smith, Duane H

    2009-01-01

    One potential method of geologically sequestering carbon dioxide (CO2) is to inject the gas into brine-filled, subsurface formations. Within these low-permeability rocks, fractures exist that can act as natural fluid conduits. Understanding how a less viscous fluid moves when injected into an initially saturated rock fracture is important for the prediction of CO2 transport within fractured rocks. Our study examined experimentally and numerically the motion of immiscible fluids as they were transported through models of a fracture in Berea sandstone. The natural fracture geometry was initially scanned using micro-computerized tomography (CT) at a fine volume-pixel (voxel) resolution by Karpyn et al. [1]. This CT scanned fracture was converted into a numerical mesh for two-phase flow calculations using the finite-volume solver FLUENT® and the volume-of-fluid method. Additionally, a translucent experimental model was constructed using stereolithography. The numerical model was shown to agree well with experiments for the case of a constant rate injection of air into the initially water-saturated fracture. The invading air moved intermittently, quickly invading large-aperture regions of the fracture. Relative permeability curves were developed to describe the fluid motion. These permeability curves can be used in reservoir-scale discrete fracture models for predictions of fluid motion within fractured geological formations. The numerical model was then changed to better mimic the subsurface conditions at which CO2 will move into brine saturated fractures. The different fluid properties of the modeled subsurface fluids were shown to increase the amount of volume the less-viscous invading gas would occupy while traversing the fracture.

  17. Lattice Boltzmann simulation of immiscible fluid displacement in porous media: Homogeneous versus heterogeneous pore network

    SciTech Connect

    Liu, Haihu; Zhang, Yonghao; Valocchi, Albert J.

    2015-05-15

    Injection of anthropogenic carbon dioxide (CO{sub 2}) into geological formations is a promising approach to reduce greenhouse gas emissions into the atmosphere. Predicting the amount of CO{sub 2} that can be captured and its long-term storage stability in subsurface requires a fundamental understanding of multiphase displacement phenomena at the pore scale. In this paper, the lattice Boltzmann method is employed to simulate the immiscible displacement of a wetting fluid by a non-wetting one in two microfluidic flow cells, one with a homogeneous pore network and the other with a randomly heterogeneous pore network. We have identified three different displacement patterns, namely, stable displacement, capillary fingering, and viscous fingering, all of which are strongly dependent upon the capillary number (Ca), viscosity ratio (M), and the media heterogeneity. The non-wetting fluid saturation (S{sub nw}) is found to increase nearly linearly with logCa for each constant M. Increasing M (viscosity ratio of non-wetting fluid to wetting fluid) or decreasing the media heterogeneity can enhance the stability of the displacement process, resulting in an increase in S{sub nw}. In either pore networks, the specific interfacial length is linearly proportional to S{sub nw} during drainage with equal proportionality constant for all cases excluding those revealing considerable viscous fingering. Our numerical results confirm the previous experimental finding that the steady state specific interfacial length exhibits a linear dependence on S{sub nw} for either favorable (M ≥ 1) or unfavorable (M < 1) displacement, and the slope is slightly higher for the unfavorable displacement.

  18. Deformation and Break-up of Suspension Droplets Sheared in an Immiscible Fluid

    NASA Astrophysics Data System (ADS)

    Desse, Melinda; Hill, Sandra E.; Mitchell, John R.; Wolf, Bettina; Budtova, Tatiana

    2008-07-01

    The deformation and break-up behaviour of suspension droplets immersed in an immiscible fluid has not been widely studied albeit such systems are frequently encountered in every day multiphase products such as foods and cosmetics. Starch is a common thickener used in the food industry. Starch suspensions have shown to offer better flavour perception than polymer thickened solutions; a better understanding of their behaviour under flow would be beneficial in terms of advancement on product formulation. Deformation and break-up of a droplet of swollen-in-water starch granules placed in high viscosity silicon oil was visualised using a counter-rotating parallel-plate shear cell. The silicon oil had a high viscosity to induce shear stresses high enough to deform the droplet; it is also transparent and inert towards the studied system. The starch suspension was prepared to have a volume fraction of 100% swollen granules, i.e. that all water was bound within the swollen starch granules. The shear flow behaviour of this starch suspension is characterised by an apparent yield stress, shear-thinning and first normal stress differences. The rheo-optical experiments were conducted as start-up flow experiments applying shear stresses above the apparent yield stress. A constant shear stress throughout the experiment allows a constant viscosity of the droplet and therefore rules out the shear thinning aspect. Analysis showed droplet break-up at critical Capillary numbers close to those reported for Newtonian fluids. The results demonstrate that the droplet break-up behaviour in a complex emulsion system submitted to shear flow may not be fully described by the rheology of the individual phases alone but may require a microstructure component.

  19. Effects of shear during the cooling on the rheology and morphology of immiscible polymer blends

    NASA Astrophysics Data System (ADS)

    Hammani, S.; Moulai-Mostefa, N.; Benyahia, L.; Tassin, J. F.

    2014-08-01

    The aim of this work was the generation of a microfibrillar structure in immiscible polymer blends using a new technique. The blend polymer model is the emulsion formed by a mixture of polypropylene (PP) with polystyrene (PS) in the proportion of PP10/PS90. In the first case the pellets of polystyrene and polypropylene were blended on the twin-screw mini extruder in the classical manner with different shear rates. In the second case, the same blend was prepared in the same way followed by a dynamic cooling at different shear rates. The phase morphologies of PP in the blend were determined by Scanning Electron Microscopy on two directions (transversal and longitudinal direction to the flow). In the two cases, the dispersed phase size decreased with the increase of the shear rate in the extruder. An anomaly was registered in the classical method at 200 rpm, where the size of the dispersed phase increases with the increase of the shear rate. The dynamic cooling technique recorded smaller diameters (4 to 5 times) of the dispersed phase compared to the conventional technique. In addition, the reappearance of the microfilaments at 200rpm was observed. The rheological properties were determined by RS100 (Thermo Scientific Haake). Using this new technique, it was noticed that he elastic modulus increases with one decade compared to the classical method and the complex viscosity decreases with the increase of the shear rate. An anomaly was registered in the classical technique, where the dynamic viscosity at 200rpm increases with increasing the shear rate in the extruder.

  20. Arctic low-level boundary layer clouds: in situ measurements and simulations of mono- and bimodal supercooled droplet size distributions at the top layer of liquid phase clouds

    NASA Astrophysics Data System (ADS)

    Klingebiel, M.; de Lozar, A.; Molleker, S.; Weigel, R.; Roth, A.; Schmidt, L.; Meyer, J.; Ehrlich, A.; Neuber, R.; Wendisch, M.; Borrmann, S.

    2015-01-01

    Aircraft borne optical in situ size distribution measurements were performed within Arctic boundary layer clouds with a special emphasis on the cloud top layer during the VERtical Distribution of Ice in Arctic clouds (VERDI) campaign in April and May 2012. An instrumented Basler BT-67 research aircraft operated out of Inuvik over the Mackenzie River delta and the Beaufort Sea in the Northwest Territories of Canada. Besides the cloud particle and hydrometeor size spectrometers the aircraft was equipped with instrumentation for aerosol, radiation and other parameters. Inside the cloud, droplet size distributions with monomodal shapes were observed for predominantly liquid-phase Arctic stratocumulus. With increasing altitude inside the cloud the droplet mean diameters grew from 10 to 20 μm. In the upper transition zone (i.e., adjacent to the cloud-free air aloft) changes from monomodal to bimodal droplet size distributions (Mode 1 with 20 μm and Mode 2 with 10 μm diameter) were observed. It is shown that droplets of both modes co-exist in the same (small) air volume and the bimodal shape of the measured size distributions cannot be explained as an observational artifact caused by accumulating data point populations from different air volumes. The formation of the second size mode can be explained by (a) entrainment and activation/condensation of fresh aerosol particles, or (b) by differential evaporation processes occurring with cloud droplets engulfed in different eddies. Activation of entrained particles seemed a viable possibility as a layer of dry Arctic enhanced background aerosol (which was detected directly above the stratus cloud) might form a second mode of small cloud droplets. However, theoretical considerations and model calculations (adopting direct numerical simulation, DNS) revealed that, instead, turbulent mixing and evaporation of larger droplets are the most likely reasons for the formation of the second droplet size mode in the uppermost region

  1. Marangoni-driven spreading along liquid-liquid interfaces

    NASA Astrophysics Data System (ADS)

    Berg, S.

    2009-03-01

    Marangoni-driven spreading at gas-liquid interfaces has been studied extensively over the past years but so far the spreading kinetics along the interface between immiscible liquids has not been investigated systematically. In this study, the spreading kinetics of aqueous solutions of sodium dodecyl sulfate and dodecyl trimethyl ammonium bromide along the interface between thick layers of water and decane has been investigated by means of two different optical visualization techniques (dye tracer and laser shadowgraphy). The spreading kinetics follows a power law where the radius r as function of time t scales as r(t )∝t3/4 indicating large similarities with Marangoni-driven spreading at air-liquid interfaces. The existing scaling law for spreading at air-liquid interfaces is based on the balance between an interfacial tension gradient and the viscous stress in the fluid layers beneath the interface. When the viscous dissipation in the two boundary layers below and above the interface is factored into the scaling law, quantitative agreement with experimental data is obtained. Marangoni-driven spreading along an interface is a fast transport mechanism. The velocity of the leading edge lies within the range of group velocities of capillary waves.

  2. Analysis of bacopaside I in biomatrices using liquid chromatography-tandem mass spectrometry: Pharmacokinetics and brain distribution in Swiss-albino mice.

    PubMed

    Bhateria, Manisha; Ramakrishna, Rachumallu; Puttrevu, Santosh Kumar; Singh, Rajbir; Bhatta, Rabi Sankar

    2016-06-01

    Bacopaside I (BP-I) is the major pseudojujubogenin glycoside of Bacopa monniera (BM) extract which has been widely used as a nerve tonic to improve the memory and intellect of human beings from ancient times. A selective and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of BP-I in mouse plasma and brain homogenate has been developed and validated. All biosamples were processed by liquid-liquid extraction and chromatographed on C18- reversed phase column using mobile phase consisting of ammonium acetate (10mM, pH 4) - acetonitrile (10:90, v/v) at a flow rate of 0.5mL/min. The detection was performed in negative electrospray ionization mode and the precursor/product ion transitions of BP-I and internal standard (IS) hydrochlorothiazide were quantified in multiple reaction monitoring (MRM) using QTRAP-5500 MS/MS. The linearity was established over the concentration range of 0.5-2000ng/mL (r(2)>0.990), with lower limit of quantification (LLOQ) of 0.5ng/mL in both plasma and brain matrix. Within- and between-run precision and accuracy were well within the acceptable limits of variation. Consistent and reproducible recovery (>70%) was obtained with insignificant matrix effect for BP-I and IS. The method fulfilled US Food and Drug Administration (USFDA) guidelines for bioanalytical method validation in terms of selectivity, sensitivity, linearity, accuracy, precision, matrix effect, dilution integrity, carry-over effect and stability. Further, the method was successfully applied to execute the plasma pharmacokinetics and brain distribution of BP-I in Swiss-albino mice following intravenous administration at a dose of 5mg/kg. PMID:27017568

  3. Liquid-phase epitaxy grown PbSnTe distributed feedback laser diodes with broad continuous single-mode tuning range

    NASA Technical Reports Server (NTRS)

    Hsieh, H.-H.; Fonstad, C. G.

    1980-01-01

    Distributed feedback (DFB) pulsed laser operation has been demonstrated in stripe geometry Pb(1-x)Sn(x)Te double-heterostructures grown by liquid-phase epitaxy. The grating structure of 0.79 micron periodicity operates in first order near 12.8 microns and was fabricated prior to the liquid-phase epitaxial growth using holographic exposure techniques. These DFB lasers had moderate thresholds, 3.6 kA/sq cm, and the output power versus current curves exhibited a sharp turn-on free of kinks. Clean, single-mode emission spectra, continuously tunable over a range in excess of 20 per cm, centered about 780 per cm (12.8 microns), and at an average rate of 1.2 per cm-K from 9 to 26 K, were observed. While weaker modes could at times be seen in the spectrum, substantially single-mode operation was obtained over the entire operating range and to over 10 times threshold.

  4. Quantification of gastrointestinal liquid volumes and distribution following a 240 mL dose of water in the fasted state.

    PubMed

    Mudie, Deanna M; Murray, Kathryn; Hoad, Caroline L; Pritchard, Susan E; Garnett, Martin C; Amidon, Gordon L; Gowland, Penny A; Spiller, Robin C; Amidon, Gregory E; Marciani, Luca

    2014-09-01

    The rate and extent of drug dissolution and absorption from solid oral dosage forms is highly dependent upon the volumes and distribution of gastric and small intestinal water. However, little is known about the time courses and distribution of water volumes in vivo in an undisturbed gut. Previous imaging studies offered a snapshot of water distribution in fasted humans and showed that water in the small intestine is distributed in small pockets. This study aimed to quantify the volume and number of water pockets in the upper gut of fasted healthy humans following ingestion of a glass of water (240 mL, as recommended for bioavailability/bioequivalence (BA/BE) studies), using recently validated noninvasive magnetic resonance imaging (MRI) methods. Twelve healthy volunteers underwent upper and lower abdominal MRI scans before drinking 240 mL (8 fluid ounces) of water. After ingesting the water, they were scanned at intervals for 2 h. The drink volume, inclusion criteria, and fasting conditions matched the international standards for BA/BE testing in healthy volunteers. The images were processed for gastric and intestinal total water volumes and for the number and volume of separate intestinal water pockets larger than 0.5 mL. The fasted stomach contained 35 ± 7 mL (mean ± SEM) of resting water. Upon drinking, the gastric fluid rose to 242 ± 9 mL. The gastric water volume declined rapidly after that with a half emptying time (T50%) of 13 ± 1 min. The mean gastric volume returned back to baseline 45 min after the drink. The fasted small bowel contained a total volume of 43 ± 14 mL of resting water. Twelve minutes after ingestion of water, small bowel water content rose to a maximum value of 94 ± 24 mL contained within 15 ± 2 pockets of 6 ± 2 mL each. At 45 min, when the glass of water had emptied completely from the stomach, total intestinal water volume was 77 ± 15 mL distributed into 16 ± 3 pockets of 5 ± 1 mL each. MRI provided unprecedented insights into

  5. The Role of Distribution Infrastructure and Equipment in the Life-cycle Air Emissions of Liquid Transportation Fuels

    NASA Astrophysics Data System (ADS)

    Strogen, Bret Michael

    Production of fuel ethanol in the United States has increased ten-fold since 1993, largely as a result of government programs motivated by goals to improve domestic energy security, economic development, and environmental impacts. Over the next decade, the growth of and eventually the total production of second generation cellulosic biofuels is projected to exceed first generation (e.g., corn-based) biofuels, which will require continued expansion of infrastructure for producing and distributing ethanol and perhaps other biofuels. In addition to identifying potential differences in tailpipe emissions from vehicles operating with ethanol-blended or ethanol-free gasoline, environmental comparison of ethanol to petroleum fuels requires a comprehensive accounting of life-cycle environmental effects. Hundreds of published studies evaluate the life-cycle emissions from biofuels and petroleum, but the operation and maintenance of storage, handling, and distribution infrastructure and equipment for fuels and fuel feedstocks had not been adequately addressed. Little attention has been paid to estimating and minimizing emissions from these complex systems, presumably because they are believed to contribute a small fraction of total emissions for petroleum and first generation biofuels. This research aims to quantify the environmental impacts associated with the major components of fuel distribution infrastructure, and the impacts that will be introduced by expanding the parallel infrastructure needed to accommodate more biofuels in our existing systems. First, the components used in handling, storing, and transporting feedstocks and fuels are physically characterized by typical operating throughput, utilization, and lifespan. US-specific life-cycle GHG emission and water withdrawal factors are developed for each major distribution chain activity by applying a hybrid life-cycle assessment methodology to the manufacturing, construction, maintenance and operation of each

  6. A liquid-helium-free superconducting coil system forming a flat minimum-magnetic-field distribution of an electron cyclotron resonance ion source

    SciTech Connect

    Yoshida, Ken-ichi Nara, Takayuki; Saitoh, Yuichi; Yokota, Watalu

    2014-02-15

    A flat distribution of the minimum magnetic field (flat-B{sub min}) of an electron cyclotron resonance ion source (ECRIS) is expected to perform better in highly charged ion production than classical B{sub min}. To form a flat-B{sub min} structure with a liquid helium-free superconducting device, a coil system of seven coils with four current leads has been designed. The lead number was reduced by connecting the plural coils in series to maintain the flat-B{sub min} structure even when the coil currents are changed for adjustment. This coil system can be operated with a helium-free cryostat, since the estimation of heat from the leads to the coils is nearly equivalent to the existing superconducting ECRIS of a similar type.

  7. Multiple liquid bridges with non-smooth interfaces

    NASA Astrophysics Data System (ADS)

    Fel, Leonid G.; Rubinstein, Boris Y.; Ratner, Vadim

    2016-08-01

    We consider a coexistence of two axisymmetric liquid bridges LB i and LB m of two immiscible liquids i and m which are immersed in a third liquid (or gas) e and trapped between two smooth solid bodies with axisymmetric surfaces S 1, S 2 and free contact lines. Evolution of liquid bridges allows two different configurations of LB i and LB m with multiple (five or three) interfaces of non-smooth shape. We formulate a variational problem with volume constraints and present its governing equations supplemented by boundary conditions. We find a universal relationship between curvature of the interfaces and discuss the Neumann triangle relations at the singular curve where all liquids meet together.

  8. Validation of a nonintrusive optical technique for the measurement of liquid mass distribution in a two-phase spray

    NASA Technical Reports Server (NTRS)

    Hartfield, Roy, Jr.

    1993-01-01

    This work is the continuation of an optical technique development program initiated as part of the 1992 Summer Faculty Fellowship Program. The 1992 work consisted of the formulation and implementation of a technique ivolving the spatial deconvolution of fluorescence data from a uniformly illuminated, seeded densed spray to obtain quantitative measurements of the liquid density profiles. This measurement approach largely overcomes substantial scattering problems associated with other optical approaches for two-phase flows. However, to apply this measurement approach with confidence to unknown flows, the technique must be validated. Consequently, technique validation using classical grid patternator techniques has been focus of the current work. This work has included the design and construction of a patternator rig and the implementation of a test program designed for the comparison of patternator data with the deconvolved optical data. The flow field used for the validation is the plume of an axisymetric swirl coaxial LOX injector being considered for use in the Space Transportation System Main Engine. The flow facility is an improved version of the test rig which was constructed in 1992 for the initial technique development. This report includes a brief description of the optical measurement technique and the patternator rig and a presentation of the data comparisons.

  9. Stochastic analysis of immiscible displacement of the fluids with arbitrary viscosities and its dependence on support scale of hydrological data

    NASA Astrophysics Data System (ADS)

    Tartakovsky, Alexandre M.; Meakin, Paul; Huang, Hai

    2004-12-01

    Stochastic analysis is commonly used to address uncertainty in the modeling of flow and transport in porous media. In the stochastic approach, the properties of porous media are treated as random functions with statistics obtained from field measurements. Several studies indicate that hydrological properties depend on the scale of measurements or support scales, but most stochastic analysis does not address the effects of support scale on stochastic predictions of subsurface processes. In this work we propose a new approach to study the scale dependence of stochastic predictions. We present a stochastic analysis of immiscible fluid-fluid displacement in randomly heterogeneous porous media. While existing solutions are applicable only to systems in which the viscosity of one phase is negligible compare with the viscosity of the other (water-air systems for example), our solutions can be applied to the immiscible displacement of fluids having arbitrarily viscosities such as NAPL-water and water-oil. Treating intrinsic permeability as a random field with statistics dependant on the permeability support scale (scale of measurements) we obtained, for one-dimensional systems, analytical solutions for the first moments characterizing unbiased predictions (estimates) of system variables, such as the pressure and fluid-fluid interface position, and we also obtained second moments, which characterize the uncertainties associated with such predictions. Next we obtained empirically scale dependent exponential correlation function of the intrinsic permeability that allowed us to study solutions of stochastic equations as a function of the support scale. We found that the first and second moments converge to asymptotic values as the support scale decreases. In our examples, the statistical moments reached asymptotic values for support scale that were approximately 1/10000 of the flow domain size. We show that analytical moment solutions compare well with the results of Monte

  10. Measurement of vapor/liquid distributions in a binary-component fuel spray using laser imaging of droplet scattering and vapor absorption

    NASA Astrophysics Data System (ADS)

    Li, Shiyan; Zhang, Yuyin; Wu, Shenqi; Xu, Bin

    2014-08-01

    Fuel volatility has a great effect on its evaporation processes and the mixture formation and thus combustion and emissions formation processes in internal combustion engines. To date, however, instead of the actual gasoline or diesel fuel, many researchers have been using single-component fuel in their studies, because the composition of the former is too complicated to understand the real physics behind the evaporation and combustion characteristics. Several research groups have reported their results on droplets evaporation in a spray of multi-component fuel, carried out both numerically and experimentally. However, there are plenty of difficulties in quantitative determination of vapor concentration and droplet distributions of each component in a multicomponent fuel spray. In this study, to determine the vapor phase concentration and droplet distributions in an evaporating binary component fuel spray, a laser diagnostics based on laser extinction by droplet scattering and vapor absorption was developed. In practice, measurements of the vapor concentration distributions of the lower (n-tridencane) and higher (n-octane) volatility components in the binary component fuel sprays have been carried out at ambient temperatures of 473K and 573K, by substituting p-xylene for noctane or α-methylnaphthalene for n-tridecane. p-Xylene and α-methylnaphthalene were selected as the substitutes is because they have strong absorption band near 266nm and transparent near 532nm and, their thermo-physical properties are similar to those of the original component. As a demonstration experiment, vapor/liquid distribution of the lower boiling point (LBP) and higher boiling point (HBP) components in the binary component fuel spray have been obtained.

  11. Distributed feedback laser with optoelectronic tunability in dye-doped cholesteric liquid crystal with coated photoconductive layer

    NASA Astrophysics Data System (ADS)

    Lee, C.-R.; Huang, S.-C.; Lin, S.-H.; Lin, Z.-Y.; Huang, S.-Y.; Mo, T.-S.

    2011-12-01

    This work investigates, for the first time, an optoelectronically tunable distributed feedback laser that is based on a planar DDCLC cell with a coated photoconductive (PC) layer. Experimental results show that the CLC reflection band and the lasing wavelength of the DDCLC can both be tuned optoelectronically by varying the intensity of one irradiating CW green beam or the magnitude of the applied dc voltage. The tunability of the DDCLC laser depends on the controllability of the optoelectronic properties of the PC layer and, therefore, on the voltage dropping on the CLC layer. Therefore, the CLC pitch can be controlled by exploiting the optoelectronically induced electrohydrodynamic effect which causes the spatially periodic deformation of the CLC structure. In addition, the dependences for other critical lasing parameters, e.g., energy threshold, lasing efficiency, and lasing linewidth, on external controlling signals are also measured and discussed in the current study.

  12. Quartz-tourmaline orbicules: Record of magmatic melt immiscibility in the Land's End granite, SW England

    NASA Astrophysics Data System (ADS)

    Drivenes, Kristian; Larsen, Rune; Müller, Axel; Sorensen, Bjorn; Wiedenbeck, Michael; Raanes, Morten

    2014-05-01

    extrinsic hydrothermal fluid is unlikely. We propose that the orbicules formed from an immiscible hydrous B-Fe rich melt that coalesced to the orbicules, and crystallized in a eutectic manner during the last stages of crystallization.

  13. Measurement and analysis of internal stress distributions created in gelatin simulated-brain tissue by a pulsed laser-induced liquid jet.

    PubMed

    Kato, T; Arafune, T; Washio, T; Nakagawa, A; Ogawa, Y; Tominaga, T; Sakuma, I; Kobayashi, E

    2014-01-01

    Transsphenoidal surgery is currently employed to treat complex lesions beyond the sella turcica; however, the procedure can be limited by difficulties encountered in dealing with small blood vessels, deep and narrow working spaces, and awkward working angles. To overcome these problems, we have developed a pulsed laser-induced liquid jet system that can dissect tumor tissue while preserving fine blood vessels within deep and narrow working spaces. We have previously evaluated the utility and safety of this procedure. However, the effects of the pulsejet after being injected into the brain are not yet well understood. Especially, the behavior of the stress distribution created by the jet is important because it has recently been reported that high acoustic pressures can affect the brain. In this study, we measured internal stress distributions in a gelatin simulated-brain using photoelasticity experiments. We used a high-speed camera with an image sensor on which an array of micropolarizers was attached to measure the stresses and the shear wave created when the pulsejet enters the simulated brain. PMID:25570972

  14. Drug-to-antibody ratio (DAR) and drug load distribution by hydrophobic interaction chromatography and reversed phase high-performance liquid chromatography.

    PubMed

    Ouyang, Jun

    2013-01-01

    Hydrophobic interaction chromatography (HIC) is the method of choice for determination of the drug-to-antibody ratio (DAR) and drug load distribution for cysteine (Cys)-linked antibody-drug conjugates (ADCs). The drug-loaded species are resolved based on the increasing hydrophobicity with the least hydrophobic, unconjugated form eluting first and the most hydrophobic, 8-drug form eluting last. The area percentage of a peak represents the relative distribution of the particular drug-loaded ADC species. The weighted average DAR is then calculated using the percentage peak area information and the drug load numbers. Reversed phase high-performance liquid chromatography (RP-HPLC) offers an orthogonal method to obtain DAR for Cys-linked ADCs. The method involves, first, a reduction reaction to completely dissociate the heavy and light chains of the ADC, then separation of the light and heavy chains and their corresponding drug-loaded forms on an RP column. The percentage peak area from integration of the light chain and heavy chain peaks, combined with the assigned drug load for each peak, is used to calculate the weighted average DAR. PMID:23913154

  15. Brain tissue distribution of spinosin in rats determined by a new high-performance liquid chromatography-electrospray ionization-mass/mass spectrometry method.

    PubMed

    Zhang, Yanqing; Zhang, Ting; Wang, Fengling; Xie, Junbo

    2015-01-01

    Spinosin, a flavone-C-glycoside, is a bioactive ingredient isolated from a traditional Chinese herb Zizyphi Spinosi Semen. In this study, a new high-performance liquid chromatography-electrospray ionization-mass/mass spectrometry method was developed and validated to determine spinosin in brain tissues including olfactory region, hippocampus, corpus striatum, cerebrum (cerebral cortex) and cerebellum, after intravenous administration with the dose of 5 mg/kg. The tissue homogenate samples were pretreated and extracted with acetonitrile by a simple protein precipitation method. The separation was performed on a YMC ODS-AQ(TM) column (250 × 2.0 mm, 3.5 μm) with the mobile phase of acetonitrile-aqueous phase (0.1% formic acid) (25 : 75, v/v) at a flow rate of 0.3 mL/min. The retention times of spinosin and naringin (internal standard) were 3.3 and 5.1 min, respectively. Multiple reaction monitoring mode was used to monitor precursor/product ion transitions of m/z 607.2 → 427.0 for spinosin and m/z 579.2 → 271.0 for naringin. The proposed method was successfully applied to the preclinical brain tissue distribution of spinosin in rats. The results showed that there was a wide brain regional tissue distribution of spinosin. The concentrations of spinosin in corpus striatum and hippocampus were higher than that in other areas. PMID:24771055

  16. In vivo pharmacokinetics of and tissue distribution study of physalin B after intravenous administration in rats by liquid chromatography with tandem mass spectrometry.

    PubMed

    Zheng, Yunliang; Chen, Jing; Liu, Lin; Liang, Xingguang; Hong, Dongsheng

    2016-08-01

    A rapid and sensitive liquid chromatography tandem mass spectrometry quantitative analysis method was established for the pharmacokinetics and tissue distribution study of physalin B in rat. Physalin B and physalin H (internal standard, IS) were separated on an Agilent Eclips XDB C8 column. MS detection was performed on a triple quadrupole tandem mass spectrometer in the multiple reaction monitoring mode with a positive eletrospray ionization source. The assay was validated in the concentration ranges of 22.6-22600 ng/mL for heart and lung and 4.52-4520 ng/mL for other tissues. The intra- and inter-day precisions (RSD) were ≤9.23 and ≤12.51%, respectively, with accuracy (%) in the range of 88.07-113.2%. A pharmacokinetic study showed that physalin B has a long dwell time with a half-life of 321.2 ± 29.5 min and clearance of 175.4 ± 25.7 mL/min/kg after intravenous administration. Additionally, physalin B showed a wide tissue distribution with a special higher penetration in lung. The data presented in this study could provide useful information for the further study of physalin B. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26714262

  17. Preclinical pharmacokinetics, tissue distribution and excretion studies of a potential analgesics - corydaline using an ultra performance liquid chromatography-tandem mass spectrometry.

    PubMed

    Wang, Jianfeng; Liang, Lishuang; Zhang, Qiongyu; Li, Xingang; Fu, Zhijian

    2013-12-30

    A rapid resolution ultra performance liquid chromatography (UPLC) coupled with electrospray ionization (ESI) mass spectrometry method was developed and validated for the quantitative analysis of corydaline in rats' plasma and various tissues for pharmacokinetic, tissue distribution and excretion studies of corydaline. The analytes were separated on an Acquity UPLC BEH C18 column (2.1mm×100mm, 1.7μm) and detected with a triple quadrupole mass spectrometer using positive ion ESI in the multiple reaction monitoring (MRM) mode. The MS/MS ion transitions monitored were m/z 370.0→192.0 for corydaline and 354.1→188.0 for IS, respectively. Calibration curves (1/x(2) weighted) offered satisfactory linearity (r(2)>0.9984) within 1-1000ng/mL. The accuracy and precision ranged from -7.4% to 8.5% and 3.4% to 12.8%, respectively. The absolute matrix effect (94.2-119.2%), relative matrix effect (1.7-9.6%) and recoveries (81.4-93.7%) were satisfactory in all the biological matrices examined. The assay was successfully applied to the plasma pharmacokinetics, tissue distribution and excretion studies of corydaline in rats. The pharmacokinetic parameters such as half-life (t1/2), mean residence time (MRT) and maximum concentration (Cmax) were determined. These preclinical data of corydaline would be useful for the clinical reference. PMID:24216274

  18. Optical Fiber Distributed Sensing Structural Health Monitoring (SHM) Strain Measurements Taken During Cryotank Y-Joint Test Article Load Cycling at Liquid Helium Temperatures

    NASA Technical Reports Server (NTRS)

    Allison, Sidney G.; Prosser, William H.; Hare, David A.; Moore, Thomas C.; Kenner, Winfred S.

    2007-01-01

    This paper outlines cryogenic Y-joint testing at Langley Research Center (LaRC) to validate the performance of optical fiber Bragg grating strain sensors for measuring strain at liquid helium temperature (-240 C). This testing also verified survivability of fiber sensors after experiencing 10 thermal cool-down, warm-up cycles and 400 limit load cycles. Graphite composite skins bonded to a honeycomb substrate in a sandwich configuration comprised the Y-joint specimens. To enable SHM of composite cryotanks for consideration to future spacecraft, a light-weight, durable monitoring technology is needed. The fiber optic distributed Bragg grating strain sensing system developed at LaRC is a viable substitute for conventional strain gauges which are not practical for SHM. This distributed sensing technology uses an Optical Frequency Domain Reflectometer (OFDR). This measurement approach has the advantage that it can measure hundreds of Bragg grating sensors per fiber and the sensors are all written at one frequency, greatly simplifying fiber manufacturing. Fiber optic strain measurements compared well to conventional strain gauge measurements obtained during these tests. These results demonstrated a high potential for a successful implementation of a SHM system incorporating LaRC's fiber optic sensing system on the composite cryotank and other future cryogenic applications.

  19. Optical fiber distributed sensing structural health monitoring (SHM) strain measurements taken during cryotank Y-joint test article load cycling at liquid helium temperatures

    NASA Astrophysics Data System (ADS)

    Allison, Sidney G.; Prosser, William H.; Hare, David A.; Moore, Thomas C.; Kenner, W. S.

    2007-09-01

    This paper outlines cryogenic Y-joint testing at Langley Research Center (LaRC) to validate the performance of optical fiber Bragg grating strain sensors for measuring strain at liquid helium temperature (-240°C). This testing also verified survivability of fiber sensors after experiencing 10 thermal cool-down, warm-up cycles and 400 limit load cycles. Graphite composite skins bonded to a honeycomb substrate in a sandwich configuration comprised the Y-joint specimens. To enable SHM of composite cryotanks for consideration to future spacecraft, a light-weight, durable monitoring technology is needed. The fiber optic distributed Bragg grating strain sensing system developed at LaRC is a viable substitute for conventional strain gauges which are not practical for SHM. This distributed sensing technology uses an Optical Frequency Domain Reflectometer (OFDR). This measurement approach has the advantage that it can measure hundreds of Bragg grating sensors per fiber and the sensors are all written at one frequency, greatly simplifying fiber manufacturing. Fiber optic strain measurements compared well to conventional strain gauge measurements obtained during these tests. These results demonstrated a high potential for a successful implementation of a SHM system incorporating LaRC's fiber optic sensing system on the composite cryotank and other future cryogenic applications.

  20. Coexisting Liquid Phases Underlie Nucleolar Subcompartments.

    PubMed

    Feric, Marina; Vaidya, Nilesh; Harmon, Tyler S; Mitrea, Diana M; Zhu, Lian; Richardson, Tiffany M; Kriwacki, Richard W; Pappu, Rohit V; Brangwynne, Clifford P

    2016-06-16

    The nucleolus and other ribonucleoprotein (RNP) bodies are membrane-less organelles that appear to assemble through phase separation of their molecular components. However, many such RNP bodies contain internal subcompartments, and the mechanism of their formation remains unclear. Here, we combine in vivo and in vitro studies, together with computational modeling, to show that subcompartments within the nucleolus represent distinct, coexisting liquid phases. Consistent with their in vivo immiscibility, purified nucleolar proteins phase separate into droplets containing distinct non-coalescing phases that are remarkably similar to nucleoli in vivo. This layered droplet organization is caused by differences in the biophysical properties of the phases-particularly droplet surface tension-which arises from sequence-encoded features of their macromolecular components. These results suggest that phase separation can give rise to multilayered liquids that may facilitate sequential RNA processing reactions in a variety of RNP bodies. PAPERCLIP. PMID:27212236

  1. [Perfluorocarbon liquids and vitreoretinal surgery in 2011].

    PubMed

    Chiquet, C; Thuret, G

    2011-11-01

    Perfluorocarbon liquids (PFCLs) are one of the most innovative recent tools for vitreoretinal surgery. PFCLs are characterized by their number of carbon atoms, which has an impact on the density, viscosity, surface tension, vapor pressure, the boiling point, and the refraction index. PFCLs are routinely used because of their high gravity (double that of water) and their low viscosity. Furthermore, they are immiscible in water, optically clear with refraction indices similar to that of water, allowing visualization of an interface between the PFCL and saline. The use of intravitreally injected liquid PFCLs as adjunctive agents to vitreoretinal surgery plays an important role in facilitating retinal reattachment, especially in cases of giant retinal tear, trauma, and/or proliferative vitreoretinopathy. PFCLs are also used as intraoperative instruments to re-establish intraocular volume, assist in separating membranes adherent to the retina (in proliferative diabetic retinopathy, for example), and manage the dislocated crystalline lens and intraocular lens. PMID:21943797

  2. Aggregation Behavior of Several Ionic Liquids in Molecular Solvents of Low Polarity--Indication of a Bimodal Distribution.

    PubMed

    Cade, Elise A; Petenuci, João; Hoffmann, Markus M

    2016-02-16

    The structure and dynamics of ion pairing and aggregation is studied by concentration- and temperature-dependent measurements of (1) H and (19) F self-diffusion coefficients, viscosity, and conductivity for the following five solutions: 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide ([Cn mim][NTf2], n=2, 4, 6) in dichloromethane (CH2Cl2), and [C6 mim][NTf2] in tetrahydrofuran (THF) and chlorobenzene (C6 H5 Cl). The temperature dependence of these properties at constant IL concentrations follows the Arrhenius law for all five solutions. The IL-concentration dependence of the respective activation energies obtained from the Arrhenius analysis is nonlinear in the case of conductivity, but indicates linear relationships for viscosity and self-diffusion. All five solutions studied display average solute radius maxima as plotted against IL concentration. The maximum average solute radii follow an order of solvents of CHCl3 >C6 H5 Cl>CH2 Cl2 ≈THF, which corresponds to the order of increasing solvent dielectric constant. The observed trends in the physical properties of these solutions indicate the development of a bimodal distribution of solute size with increasing IL concentration. Specifically, the presence of aggregates is supported by the analysis of the conductivity data and the observation of the same self-diffusion coefficients for the cation and anion. The concurrent presence of freely dissolved ions is supported by the obtained average solute radii that do not exceed the radii of the corresponding ion pairs. PMID:26684927

  3. Application of the semi-empirical method to determine the spatial distribution function for thermalized photoelectrons created by vacuum ultraviolet or high-energy irradiation of some nonpolar dielectric liquids

    NASA Astrophysics Data System (ADS)

    Guelfucci, J. P.; Fitte-Rey, J.; Casanovas, J.; Baird, J. K.

    1997-06-01

    A semi-empirical method is tested to determine the spatial distribution function of the thermalized photoelectrons, created by vacuum ultraviolet (VUV) or γ irradiations of some liquid alkanes. It seems that modified exponentials must be associated to the thermalization process on VUV irradiation. A Gaussian distribution function could be used for high-energy irradiation. The partial inadequacy of the method in the case of high-energy irradiation can be imputed to the existence of multiple ion pair recombinations.

  4. Turbulent drag reduction over air- and liquid- impregnated surfaces

    NASA Astrophysics Data System (ADS)

    Rosenberg, Brian J.; Van Buren, Tyler; Fu, Matthew K.; Smits, Alexander J.

    2016-01-01

    Results on turbulent skin friction reduction over air- and liquid-impregnated surfaces are presented for aqueous Taylor-Couette flow. The surfaces are fabricated by mechanically texturing the inner cylinder and chemically modifying the features to make them either non-wetting with respect to water (air-infused, or superhydrophobic case), or wetting with respect to an oil that is immiscible with water (liquid-infused case). The drag reduction, which remains fairly constant over the Reynolds number range tested (100 ≤ Reτ ≤ 140), is approximately 10% for the superhydrophobic surface and 14% for the best liquid-infused surface. Our results suggest that liquid-infused surfaces may enable robust drag reduction in high Reynolds number turbulent flows without the shortcomings associated with conventional superhydrophobic surfaces, namely, failure under conditions of high hydrodynamic pressure and turbulent flow fluctuations.

  5. Nanoparticles at liquid interfaces: Rotational dynamics and angular locking

    SciTech Connect

    Razavi, Sepideh; Kretzschmar, Ilona; Koplik, Joel; Colosqui, Carlos E.

    2014-01-07

    Nanoparticles with different surface morphologies that straddle the interface between two immiscible liquids are studied via molecular dynamics simulations. The methodology employed allows us to compute the interfacial free energy at different angular orientations of the nanoparticle. Due to their atomistic nature, the studied nanoparticles present both microscale and macroscale geometrical features and cannot be accurately modeled as a perfectly smooth body (e.g., spheres and cylinders). Under certain physical conditions, microscale features can produce free energy barriers that are much larger than the thermal energy of the surrounding media. The presence of these energy barriers can effectively “lock” the particle at specific angular orientations with respect to the liquid-liquid interface. This work provides new insights on the rotational dynamics of Brownian particles at liquid interfaces and suggests possible strategies to exploit the effects of microscale features with given geometric characteristics.

  6. Multiphase flow of miscible liquids: jets and drops

    NASA Astrophysics Data System (ADS)

    Walker, Travis W.; Logia, Alison N.; Fuller, Gerald G.

    2015-05-01

    Drops and jets of liquids that are miscible with the surrounding bulk liquid are present in many processes from cleaning surfaces with the aid of liquid soaps to the creation of biocompatible implants for drug delivery. Although the interactions of immiscible drops and jets show similarities to miscible systems, the small, transient interfacial tension associated with miscible systems create distinct outcomes such as intricate droplet shapes and breakup resistant jets. Experiments have been conducted to understand several basic multiphase flow problems involving miscible liquids. Using high-speed imaging of the morphological evolution of the flows, we have been able to show that these processes are controlled by interfacial tensions. Further multiphase flows include investigating miscible jets, which allow the creation of fibers from inelastic materials that are otherwise difficult to process due to capillary breakup. This work shows that stabilization from the diminishing interfacial tensions of the miscible jets allows various elongated morphologies to be formed.

  7. Diffusive partitioning tracer test for the quantification of nonaqueous phase liquid (NAPL) in the vadose zone: Performance evaluation for heterogeneous NAPL distribution

    NASA Astrophysics Data System (ADS)

    Werner, David; Karapanagioti, Hrissi K.; Höhener, Patrick

    2009-08-01

    A partitioning tracer test based on gas-phase diffusion in the vadose zone yields estimates of the residual nonaqueous phase liquid (NAPL) saturation. The present paper investigates this technique further by studying diffusive tracer breakthrough curves in the vadose zone for a heterogeneous NAPL distribution. Tracer experiments were performed in a lysimeter with a horizontal layer of artificial kerosene embedded in unsaturated sand. Tracer disappearance curves at the injection point and tracer breakthrough curves at some distance from the injection point were measured inside and outside of the NAPL layer. A numerical code was used to generate independent model predictions based on the physicochemical sand, NAPL, and tracer properties. The measured and modeled tracer breakthrough curves were in good agreement confirming the validity of important modeling assumptions such as negligible sorption of chlorofluorocarbon (CFC) tracers to the uncontaminated sand and their fast reversible partitioning between the soil air and the NAPL phase. Subsequently, the model was used to investigate different configurations of NAPL contamination. The experimental and model results show that the tracer disappearance curves of a single-well diffusive partitioning tracer test (DPTT) are dominated by the near-field presence of NAPL around the tip of the soil gas probe. In contrast, breakthrough curves of inter-well tracer tests reflect the NAPL saturation in between the probes, although there is no unique interpretation of the tracer signals if the NAPL distribution is heterogeneous. Numerical modeling is useful for the planning of a DPTT application. Simulations suggest that several cubic meters of soil can be investigated with a single inter-well partitioning tracer test of 24-hour duration by placing the injection point in the center of the investigated soil volume and probes at up to 1 m distance for the monitoring of gaseous tracers.

  8. Lipid immiscibility and biophysical properties: Molecular order within and among unit cell volumes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Saturated and unsaturated fatty acids clearly have a discrete chemical structure in the solid state. In a saturated solution, the solid state and solution state are in chemical equilibrium. The lipid stearic acid packs in unit cell volumes in the liquid state as well as in the solid state. Normal...

  9. Proposal for new best estimates for the soil solid-liquid distribution coefficient and soil-to-plant transfer of nickel.

    PubMed

    Vandenhove, Hildegarde; Van Hees, May; Olyslaegers, Geert; Vidal, Miquel

    2009-04-01

    The objective of this study was to compile data, based on an extensive literature survey, for the soil solid-liquid distribution coefficient (K(d)) and soil-to-plant transfer factor (TF) for nickel. The K(d) best estimates were calculated for soils grouped according to texture and organic matter content (sand, loam, clay and organic) and soil cofactors affecting soil-nickel interaction, such as pH, organic matter, and clay content. Variability in K(d) was better explained by pH than by soil texture. Nickel TF estimates were presented for major crop groups (cereals, leafy vegetables, non-leafy vegetables, root crops, tubers, fruits, herbs, pastures/grasses and fodder), and also for plant compartments within crop groups. Transfer factors were also calculated per soil group, as defined by their texture and organic matter content. Furthermore an evaluation of transfer factor dependency on specific soil characteristics was performed following regression analysis. The derived estimates were compared with parameter estimates currently in use. PMID:19223096

  10. Development of a liquid chromatography with mass spectrometry method for the determination of gelsemine in rat plasma and tissue: Application to a pharmacokinetic and tissue distribution study.

    PubMed

    Zhang, Shuangshuang; Hu, Shuping; Yang, Xiangxiang; Shen, Jiaqi; Zheng, Xiaoyong; Huang, Kexin; Xiang, Zheng

    2015-03-01

    Gelsemine from Gelsemium elegans Benth is a potential anesthetic and analgesic agent with no physical dependence and opiate addiction. This study was aimed at developing an ultrafast liquid chromatography coupled to tandem mass spectrometry method to quantify gelsemine in rat plasma and tissues. Plasma and tissues were processed with acetonitrile precipitation, and dendrobine was chosen as the internal standard. Sample separation was performed on an ACQUITY HSS T3 column. The mobile phase consisted of acetonitrile and 0.1% formic acid aqueous solution. Multiple reactions monitoring mode was utilized to detect the compounds of interest. The mass spectrometer was operated in the positive ion mode for detection. The MS/MS ion transitions monitored were m/z 323.2→70.5 for gelsemine and 264.2→108.05 for dendrobine, respectively. The calibration curves were linear over the range of 1-500 ng/mL in all biological matrices. The lower limit of quantification for rats plasma and tissues was 1.0 ng/mL. The values for inter- and intraday precision and accuracy were well within the ranges acceptable (< 15%). It was successfully applied to the pharmacokinetic and tissue distribution studies of gelsemine after intravenous doses of 5, 2, and 0.5 mg/kg in rats. These data of gelsemine would be useful for clinical application and further development. PMID:25580713

  11. NON-INVASIVE DETERMINATION OF THE LOCATION AND DISTRIBUTION OF FREE-PHASE DENSE NONAQUEOUS PHASE LIQUIDS (DNAPL) BY SEISMIC REFLECTION TECHNIQUES

    SciTech Connect

    Michael G. Waddell; William J. Domoracki; Tom J. Temples; Jerome Eyer

    2001-05-01

    The Earth Sciences and Resources Institute, University of South Carolina is conducting a 14 month proof of concept study to determine the location and distribution of subsurface Dense Nonaqueous Phase Liquid (DNAPL) carbon tetrachloride (CCl{sub 4}) contamination at the 216-Z-9 crib, 200 West area, Department of Energy (DOE) Hanford Site, Washington by use of two-dimensional high resolution seismic reflection surveys and borehole geophysical data. The study makes use of recent advances in seismic reflection amplitude versus offset (AVO) technology to directly detect the presence of subsurface DNAPL. The techniques proposed are a noninvasive means towards site characterization and direct free-phase DNAPL detection. This report covers the results of Task 3 and change of scope of Tasks 4-6. Task 1 contains site evaluation and seismic modeling studies. The site evaluation consists of identifying and collecting preexisting geological and geophysical information regarding subsurface structure and the presence and quantity of DNAPL. The seismic modeling studies were undertaken to determine the likelihood that an AVO response exists and its probable manifestation. Task 2 is the design and acquisition of 2-D seismic reflection data designed to image areas of probable high concentration of DNAPL. Task 3 is the processing and interpretation of the 2-D data. Task 4, 5, and 6 were designing, acquiring, processing, and interpretation of a three dimensional seismic survey (3D) at the Z-9 crib area at 200 west area, Hanford.

  12. Manifestation of Negative Compressibility in Low-Density Electron Liquids: Anomaly in the Ion-Pair Distribution Function in Supercritical Fluid Rb

    NASA Astrophysics Data System (ADS)

    Takada, Yasutami

    2006-03-01

    It is a well-known fact that the electronic compressibility κ diverges in the 3D electron gas as the density parameter rs approaches 5.25. A recent investigation clarifies that this divergence is due to the excitonic effect in the electron-hole pair excitation, in particular, to its zero-energy excitation [1]. For rs>5.25, κ becomes negative, leading to the negative static dielectric function ɛ(q,0) for at least small q owing to the compressibility sum rule. Then we can expect that two positive test charges do not repel but attract to each other in such a system. Keeping this situation in mind, we have calculated the ion-pair distribution function g(R) in the expanded Rb liquid metal by using the Monte Carlo method and found interesting features in g(R) characteristic to the negative ɛ(q,0) [2]. Such features have been observed by the recent measurement of g(R) in the supercritical fluid Rb metal with continuously increasing rs from 5.25 [3]. This confirms the situation of κ<0 in the low-density 3D electron gas for the first time. [1] YT, J. Superconductivity 18, No.3 (2005). [2] H. Maebashi and YT, to be submitted. [3] K. Matsuda and K. Tamura, private communication.

  13. Experimental Investigation of the Effect of Cooling Rate on Melilite/Liquid Distribution Coefficients for Sr, Ba, and TI in Type B Refractory Inclusion Melts

    NASA Astrophysics Data System (ADS)

    Simon, S. B.; Davis, A. M.; Richter, F. M.; Grossman, L.

    1996-03-01

    It is well established that Type B1 refractory inclusions were once at least partially molten. These inclusions are thought to represent closed magmatic systems, but attempts to model the trace element contents in melilite in these CAIs have not met with much success. Observed abundances of most trace elements tend to be significantly higher than those predicted using equilibrium melilite/liquid distribution coefficients. Boundary layers have been proposed as an explanation, but in the case of Sr, its D of ~0.8 is too high to give rise to boundary layers sufficiently enriched in Sr to account for the observed enrichments. We have investigated the possibility that Ds increase with increasing cooling rate. We found that Ds for Ti, Sr and Ba are virtually invariant with akermanite and with cooling rate, and the models still do not fit the observations, especially for Ba, which is off by a factor of ~20. The results indicate that a process occurred during the crystallization of melilite that we have yet to understand. _

  14. Development and utilization of optical low coherence reflectometry for the study of multiple scattering in randomly distributed solid-liquid suspensions

    NASA Astrophysics Data System (ADS)

    Randall, Summer Lockerbie

    The investigation of Optical Low Coherence Reflectometry (OLCR) for evaluation of highly scattering suspensions involves a balance between the observation of real systems and theoretical development. The main focus of this work was the development and utilization of OLCR to investigate highly scattering solid-liquid suspensions over a wide range of particle sizes, using monodispersed, bimodal, and polydispersed polystyrene nanosphere suspensions and Department of Energy (DOE) waste surrogates. The results were the first experimental demonstration that coherent optical backscattering from media with randomly distributed spherical nanoparticles is dominated by Mie resonances. Industrial process samples of various sizes and dispersity were also measured to expand the applicability of OLCR to a wide range of process needs. Current research has focused on the deconvolution of sample parameters from the tailing decay profiles of highly scattering matrices. Significant progress has been made on data analysis methods for monodispersed and more complex compositions of polystyrene suspensions and these methods have been applied to HLW surrogate suspensions and several industrial models. The research described within this dissertation has implications for measurement needs on basic science, industrial, and national laboratory levels. The scope of this research includes advancements in both fundamental understanding of multiple scattering through analysis of model systems and in development and application of the technology to current measurement needs within industry.

  15. Determination of xanthotoxin using a liquid chromatography-mass spectrometry and its application to pharmacokinetics and tissue distribution model in rat

    PubMed Central

    Tian, Weiqiang; Cai, Jinzhang; Xu, Yanyan; Luo, Xinhua; Zhang, Jin; Zhang, Zixue; Zhang, Qingwei; Wang, Xianqin; Hu, Lufeng; Lin, Guanyang

    2015-01-01

    A simple and selective liquid chromatography mass spectrometry method for determination of xanthotoxin in rat plasma and various tissues for pharmacokinetic was developed. Chromatographic separation was achieved on a C18 (2.1 mm × 150 mm, 5 μm) column with acetonitrile-0.1% formic acid in water as mobile phase with gradient elution. An electrospray ionization source was applied and operated in positive ion mode; selective ion monitoring (SIM) mode was used for quantification using target fragment ions m/z 217 for xanthotoxin and m/z 326 for the internal standard. The resulting calibration curves offered satisfactory linearity (R2 > 0.99) within the test range. Mean recoveries of xanthotoxin in rat plasma were in the range of 79.9%-84.6%. RSD of intra-day and inter-day precision were both < 14%. The accuracy of the method ranged from 87.5% to 109.8%. The assay was successfully applied to the pharmacokinetics and tissue distribution model studies of xanthotoxin in rats. The oral bioavailability of xanthotoxin was 73.2% in rats. PMID:26629000

  16. Performance enhancement of polymer electrolyte fuel cells by combining liquid removal mechanisms of a gas diffusion layer with wettability distribution and a gas channel with microgrooves

    NASA Astrophysics Data System (ADS)

    Utaka, Yoshio; Koresawa, Ryo

    2016-08-01

    Although polymer electrolyte fuel cells (PEFCs) are commercially available, there are still many problems that need to be addressed to improve their performance and increase their usage. At a high current density, generated water accumulates in the gas diffusion layer and in the gas channels of the cathode. This excess water obstructs oxygen transport, and as a result, cell performance is greatly reduced. To improve the cell performance, the effective removal of the generated water and the promotion of oxygen diffusion in the gas diffusion layer (GDL) are necessary. In this study, two functions proposed in previous reports were combined and applied to a PEFC: a hybrid GDL to form an oxygen diffusion path using a wettability distribution and a gas separator with microgrooves to enhance liquid removal. For a PEFC with a hybrid GDL and a gas separator with microgrooves, the concentration overvoltage of the PEFC was reduced, and the current density limit and maximum power density were increased compared with a conventional PEFC. Moreover, the stability of the cell voltage was markedly improved.

  17. Progress and investigation on lattice Boltzmann modeling of multiple immiscible fluids or components with variable density and viscosity ratios

    SciTech Connect

    Leclaire, Sébastien Reggio, Marcelo; Trépanier, Jean-Yves

    2013-08-01

    Lattice Boltzmann models for simulating multiphase flows are relatively new, and much work remains to be done to demonstrate their ability to solve fundamental test cases before they are considered for engineering problems. From this perspective, a hydrodynamic lattice Boltzmann model for simulating immiscible multiphase flows with high density and high viscosity ratios, up to O(1000) and O(100) respectively, is presented and validated against analytical solutions. The method is based on a two phase flow model with operators extended to handle N immiscible fluids. The current approach is O(N) in computational complexity for the number of different gradient approximations. This is a major improvement, considering the O(N{sup 2}) complexity found in most works. A sequence of systematic and essential tests have been conducted to establish milestones that need to be met by the proposed approach (as well as by other methods). First, the method is validated qualitatively by demonstrating its ability to address the spinodal decomposition of immiscible fluids. Second, the model is quantitatively verified for the case of multilayered planar interfaces. Third, the multiphase Laplace law is studied for the case of three fluids. Fourth, a quality index is developed for the three-phase Laplace–Young’s law, which concerns the position of the interfaces between the fluids resulting from the different surface tensions. The current model is compatible with the analytical solution, and is shown to be first order accurate in terms of this quality index. Finally, the multilayered Couette’s flow is studied. In this study, numerical results can recover the analytical solutions for all the selected test cases, as long as unit density ratios are considered. For high density and high viscosity ratios, the analytical solution is recovered for all tests, except that of the multilayered Couette’s flow. Numerical results and a discussion are presented for this unsuccessful test case

  18. Liquid atomization

    SciTech Connect

    Walzel, P. )

    1993-01-01

    A systematic review of different liquid atomizers is presented, accompanied by a discussion of various mechanisms of droplet formation in a gas atmosphere as a function of the liquid flow-regime and the geometry of the atomizer. Equations are presented for the calculation of the mean droplet-diameter. In many applications, details of the droplet size distribution are, also, important, e.g., approximate values of the breadth of the droplet formation are given. The efficiency of utilization of mechanical energy in droplet formation is indicated for the different types of atomizers. Atomization is used, in particular, for the following purposes: (1) atomization of fuels; (2) making granular products; (3) carrying out mass-transfer operations; and (4) coating of surfaces.

  19. Extraction of S- and N-Compounds from the Mixture of Hydrocarbons by Ionic Liquids as Selective Solvents

    PubMed Central

    Gabrić, Beata; Sander, Aleksandra; Cvjetko Bubalo, Marina; Macut, Dejan

    2013-01-01

    Liquid-liquid extraction is an alternative method that can be used for desulfurization and denitrification of gasoline and diesel fuels. Recent approaches employ different ionic liquids as selective solvents, due to their general immiscibility with gasoline and diesel, negligible vapor pressure, and high selectivity to sulfur- and nitrogen-containing compounds. For that reason, five imidazolium-based ionic liquids and one pyridinium-based ionic liquid were selected for extraction of thiophene, dibenzothiophene, and pyridine from two model solutions. The influences of hydrodynamic conditions, mass ratio, and number of stages were investigated. Increasing the mass ratio of ionic liquid/model fuel and multistage extraction promotes the desulfurization and denitrification abilities of the examined ionic liquids. All selected ionic liquids can be reused and regenerated by means of vacuum evaporation. PMID:23843736

  20. Extraction of S- and N-compounds from the mixture of hydrocarbons by ionic liquids as selective solvents.

    PubMed

    Gabrić, Beata; Sander, Aleksandra; Cvjetko Bubalo, Marina; Macut, Dejan

    2013-01-01

    Liquid-liquid extraction is an alternative method that can be used for desulfurization and denitrification of gasoline and diesel fuels. Recent approaches employ different ionic liquids as selective solvents, due to their general immiscibility with gasoline and diesel, negligible vapor pressure, and high selectivity to sulfur- and nitrogen-containing compounds. For that reason, five imidazolium-based ionic liquids and one pyridinium-based ionic liquid were selected for extraction of thiophene, dibenzothiophene, and pyridine from two model solutions. The influences of hydrodynamic conditions, mass ratio, and number of stages were investigated. Increasing the mass ratio of ionic liquid/model fuel and multistage extraction promotes the desulfurization and denitrification abilities of the examined ionic liquids. All selected ionic liquids can be reused and regenerated by means of vacuum evaporation. PMID:23843736